2024-03-28T11:37:34Z
https://revistas.ubiobio.cl/index.php/index/oai
oai:ojs.revistas.ubiobio.cl:article/178
2017-09-20T17:28:06Z
MCT:art.
driver
Mid-Infrared Spectroscopy And Dynamic Mechanical Analysis Of Heat-Treated Obeche (Triplochiton Scleroxylon) Wood
S. Fabiyi, James
M. Ogunleye, Bolade
chemical structure
dynamic mechanical analysis
glass transition temperature
heat-treated wood
infrared spectroscopy
rheological properties
The chemical structure change and rheological behaviour of heat-treated Obeche (Triplochiton scleroxylon) wood were investigated. Wood samples were treated at 160 and 200°C for 30, 60 and 120 minutes. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and dynamic mechanical analysis (DMA) were employed to characterize the chemical structure and rheological property of the heat-treated wood, respectively. Infrared data showed that there was a reduction in the number of hydroxyl groups (one of the factors normally attributed to water absorption) of heat treated wood relative to the control samples. The relative cellulose crystallinity increased slightly which may be one of the factors contributing to the stiffness of the heat-treated wood. The latter increases with increasing treatment temperature and time. The rheological properties of the wood samples were tested while submerged in N-methyl-2-pyrrolidone solvent under saturated conditions. DMA results showed that the increasing heat treatment time caused an increase in the glass transition temperature relative to the control sample, irrespective of the treatment temperature. Therefore, heat treatment at moderately high temperatures (160 and 200 °C) showed an interesting potential which could be used to reduce water absorption and improve flexural modulus of Obeche wood.
Universidad del Bio-Bio
2015-01-08
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/178
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 5-16
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 5-16
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/178/162
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/179
2017-09-20T17:28:06Z
MCT:art.
driver
Air Permeability Of Sugi (Cryptomeria Japonica) Wood In The Three Directions
Tanaka, Takashi
Kawai, Yasuo
Sadanari, Masanori
Shida, Satoshi
Tsuchimoto, Takahiro
air permeability
japanese cedar
radial permeability
tangential permeability
sugi
To investigate the air permeability of sugi (Cryptomeria japonica) and the effect of grain directions on it, the air permeabilities of air-dried sugi sapwood and heartwood were determined along the three material directions of wood. The value of the longitudinal permeability was the highest and that of the radial permeability was the lowest. The permeability of heartwood was about an order of magnitude less than the permeability of sapwood in the same direction. The ratio between the tangential and radial permeability was approximately 10, which was similar to softwoods that have impermeable rays. These results suggest that sugi has ray tissues that are either impermeable or have very low permeability. The radial permeability of sugi was much lower than that of Pinus, Sequoia, Juniperus, Abies and Tsuga measured with gases reported in the literature, indicating that sugi is one of the least radially permeable softwoods. These findings explain the reasons for the difficulties encountered in the drying and chemical treatment of sugi (Cryptomeria japonica).
Universidad del Bio-Bio
2015-01-08
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/179
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 17-28
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 17-28
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/179/163
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/182
2017-09-20T17:28:06Z
MCT:art.
driver
Fungicidal Effect Of Lippia Alba Essential Oil On A White-Rot Fungus
Geromini, K.V.N.
Roratto, F.B.
Ferreira, F.G.
Camilotti, J.
Vidigal, T.M.A.
Valle, J.S.
Colauto, N.B.
Linde, G.A.
alcoholic maceration
antifungal activity
aqueous infusion
hydrodistillation
pleurotus ostreatus
Lippia alba is a plant that has antifungal activity against Aspergillus, Penicillium and Trichoderma genera as well as against human pathogenic microorganisms; however, there are no records on its effect on basidiomycetes which are responsible for white rot of wood. The objective of this study was to evaluate the antifungal activity of L. alba for the control of the white-rot fungus Pleurotus ostreatus. From L. alba leaves, essential oil (EO) was extracted by hydrodistillation, alcoholic extract (AE) was obtained through alcoholic maceration, and aqueous extract (QE) from aqueous infusion. Each extract was added to several culture media to evaluate the fungicidal effect on P. ostreatus. AE and QE do not have fungicidal activity. P. ostreatus does not survive EO when concentrations are higher than 1,0 mL L-1 in malt extract liquid culture medium, or higher than 9,0 mL L-1 in particulate sawdust solid culture medium. The physical state of the cultivation medium affects the fungicidal action of EO. In surfaces subject to greater volatility, the minimum fungicidal concentration of the EO is 25,0 mL L-1. Altogether, L. alba EO is a potential alternative of biological control of basidiomycetes of white rottenness in wood.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/182
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 29-38
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 29-38
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/182/166
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/183
2017-09-20T17:28:06Z
MCT:art.
driver
Studies On The Loss Of Gloss Of Shellac And Polyurethane Finishes Exposed To Uv
Ghosh, Mili
Gupta, Sachin
Kishan Kumar, V.S.
eucalyptus
gloss
polyurethane
shellac
ultraviolet
Wood finishes protect the surface of wood from external agents, enhance its looks and improve its gloss (luster). On constant external exposure, UV rays gradually degrade the film coating resulting in loss of gloss. In this study, two commonly used finishes namely spirit shellac and polyurethane finish were used to investigate the pattern of loss of gloss due to UV interference. Two coatings of polyurethane (PU) and spirit shellac finish were applied on the surface of eucalyptus samples. The gloss levels of these and unfinished samples were monitored for different times of exposure of them to UV light. Gloss was measured at 600 gloss head using a Tri micro gloss meter regularly for 20 hours durations of UV exposure. Observations and analysis revealed that the natural gloss of uncoated samples of eucalyptus were least affected on UV exposure with only 8,3%-10% loss in gloss. The PU and shellac coated surfaces also showed very little reduction in gloss (6,9%-15,4%) most of which happened in the first 40 hours of exposure. Thus both the finishes in this study were found effective to a good extent in maintaining the gloss of the finished surface against exposure to UV light.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/183
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 39-44
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 39-44
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/183/167
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/184
2017-09-20T17:28:06Z
MCT:art.
driver
Effects Of Nano-Clay Particles And Oxidized Polypropylene Polymers On Improvement Of The Thermal Properties Of Wood Plastic Composite
Reisi Nafchi, Hajar
Abdouss, Majid
Kazemi Najafi, Saeed
Mohebbi Gargari, Rahim
Mazhar, Majid
compatibilizer
nano-clay
oxidized polypropylene
thermal properties
wood plastic composites
In this study, the effects of oxidized polypropylene, as a compatibilizer, and Nano-clay particles in improving the thermal properties of wood plastic composites are investigated. For this purpose, polypropylene polymer was oxidized in the vicinity of the air oxygen for 2 hours. Then, in order to produce the samples, Nano-clay particles at three levels (0%, 2% and 4%) were mixed with wood fibers, polypropylene polymer and the compatibilizer. Finally, the samples with thickness of 2mm and dimensions of 15×15cm were made by using hot press. For more precise investigation, the morphology of wood plastic composites was studied by using X-rays diffraction and electronic microscope images. Thermal properties of the composites were evaluated through thermal and differential analyses. The results of the thermal tests demonstrated that the addition of oxidized polypropylene and Nano-clay particles significantly improve the thermal properties of wood plastic composites. Furthermore, increment of Nano-clay particles content additionally improves thermal stability of the composites and also reduces the released heat amount during the thermal degradation. In addition, TEM images showed that the dispersion of Nano-clay particles in the composite has an intercalation structure. This subject also verified by the X-rays diffraction and it is an evidence of better thermal stability of the achieved wood plastic composites.
Universidad del Bio-Bio
2015-01-08
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/184
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 45-54
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 45-54
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/184/168
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/185
2017-09-20T17:28:06Z
MCT:art.
driver
Decay And Termite Resistance Of Particleboard Manufactured From Wood, Bamboo And Rice Husk
Rodolfo de Melo, Rafael
Martins Stangerlin, Diego
Campomanes Santana, Ricardo Robinson
Dantas Pedrosa, Talita
agricultural residues
bambusa vulgaris
biodeterioration
decay susceptibly index
eucalyptus grandis
oryza sativa
The resistance of particleboards, made from wood, bamboo and rice husk, to fungi and termites was evaluated. Panels were composed of 100% wood (Eucalyptus grandis), 100% bamboo (Bambusa vulgaris), 100% rice husk (Oryza sativa), 50% wood and 50% bamboo; and 50% wood and 50% rice husk. Panels exposed to the decay the brown-rot fungus (Gloeophyllum trabeum and the white-rot fungus (Trametes versicolor), and, in a choice feeding trial, to termites (Nasutitermes corniger). The rice husk particleboards had the highest resistance of all samples and the bamboo particleboards had the lowest resistance. T. versicolor fungi produced a larger mass loss in the particleboards than did G. trabeum.
Universidad del Bio-Bio
2015-01-08
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/185
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 55-62
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 55-62
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/185/169
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/187
2017-09-20T17:28:06Z
MCT:art.
driver
The Effect Of Nano-Zinc Oxide On Particleboard Decay Resistance
Marzbani, Pouya
Mohammadnia Afrouzi, Younes
Omidvar, Asghar
coniophora puteana
decay resistance
nano-zinc oxide
particleboard
populus deltoides
trametes versicolor
weight loss
The aim of this study was to investigate the decay resistance of particleboards treated with nano-zinc oxide against the white-rot fungus Trametes versicolor and the brown-rot species Coniophora puteana. The nanomaterial was used for manufacturing particleboards at 5, 10 and 15% wt based on the glue dry weight. The soil block decay test was performed according to ASTM D 1413 (2007) using a 12 weeks incubation period. The results showed that all treated boards had good resistance against the decay fungi and the weight loss decreased in the samples with increasing nanomaterial loading. The threshold level of treated boards against fungal decay was obtained about 21% and 17% nano-ZnO against C. puteana and T. versicolor, respectively. Therefore, it had a positive effect on increasing particleboard resistance against the fungi. The maximum decay resistance (or minimum weight loss) occurred in the samples containing 15% zinc oxide nanoparticles.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/187
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 63-68
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 63-68
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/187/170
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/188
2017-09-20T17:28:06Z
MCT:art.
driver
Characterization Of Two Cellulosic Waste Materials (Orange And Almond Peels) And Their Use For The Removal Of Methylene Blue From Aqueous Solutions
Boumediene, M.
Benaïssa, H.
George, B.
Molina, St.
Merlin, A.
adsorption
almond peels
isotherms
kinetics
modelling
orange peels
waste treatment
The ability of orange peels (OP) and almond peels (AP) as adsorbents for the removal of a dyestuff, namely methylene blue (MB) from aqueous solutions has been studied. After their characterization by different techniques (elemental analysis, biochemical analysis, IR spectroscopy, thermogravimetric analysis, scanning electron microscopy, mercury porosimetry), adsorption kinetics of the dye have been investigated using common kinetic models cited in the literature: first order and pseudo-second order. The correlation coefficient has showed that the pseudo-second order kinetic equation best describes the adsorption kinetics for the tested materials. The experimental equilibrium data have been analyzed using linearized forms of Langmuir and Freundlich isotherms. The Langmuir isotherm was found to provide the best theoretical correlation of the experimental data whatever the biosorbents tested. Using the equilibrium coefficients obtained at different temperatures, various thermodynamic parameters such as ΔG°, ΔH°, ΔS° have been calculated. The thermodynamics of MB/OP and MB/AP systems indicated spontaneous and endothermic process. It was concluded that an increase in temperature results in a higher MB loading per unit weight of OP or AP.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/188
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 69-84
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 69-84
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/188/171
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/189
2017-09-20T17:28:06Z
MCT:art.
driver
Adaptation Of The Tween 80 Assay With A Resolution V Fractional Factorial Design And Its Application To Rank Ophiostoma Fungi With Wood Extractive Degrading Capabilities
Herrera, Paula
Navarrete, José
Werner, Enrique
factorial design
lipase enzyme activity
ophiostoma floccosum
ophiostoma piceae
ophiostoma piliferum
pitch control
Wood extractives in radiata pine are the source of the observed pitch problems in the pulp and paper industry. Various methodologies have been studied and used to reduce or eliminate their negative effects. A biological treatment with albino fungi of the Ophiostoma genus, fungi that degrade the lipidic components of extractives, has been proposed as a more environmentally friendly alternative for pitch degradation.The current methods used to search for Ophiostoma albino strains with the highest degradation rates of wood extractives are labor intensive and require a large amount of resources. The Tween 80® Opacity test, an assay designed to measure lipolytic enzyme activity in filamentous fungi, was studied to verify the feasibility of its application as a methodology to rank Ophiostoma albino strains with deresination capabilities.The Tween 80® Opacity Test was first characterized by implementing a non-replicated 2k-p fractional factorial design of resolution V for a 5 factors with 16 treatments and then to study the effect of the fungus species on the lipolytic enzyme activity; a randomized one factor general factorial design was conducted. The incubation temperature; antibiotics presence; and Tween 80®, CaCl2, and peptone concentrations were investigated in the first experiment. The Ophiostoma species effect was studied in the second experiment. In both experiments, the halo area size, which was formed by the fatty acid-calcium complex precipitate, was the response variable.The results demonstrated the effectiveness of the Tween 80® opacity test to measure the lipolytic enzyme activity of Ophiostoma albino strains. Similarly, the incubation temperature and the concentrations of Tween 80®, CaCl2, and bacteriological peptone had the highest statistically significant effect on the response variable. In addition, our data demonstrated that the albino strains from the specie O. floccosum exhibited the highest rate of lipolytic enzyme production.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/189
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 85-98
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 85-98
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/189/172
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/190
2017-09-20T17:28:06Z
MCT:art.
driver
Furanic Copolymers With Synthetic And Natural Phenolic Materials For Wood Adhesives - A Maldi Tof Study
Abdalla, S.
Pizzi, A.
Bahabri, F.
Ganash, A.
oligomers distribution
phenol-furanic resins
tannin-furanic resins
wood adhesives
The structure of traditional, linear phenol-formaldehyde (PF) resins and phenol-furfural (P-Furan) resins has been investigated by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectroscopy. The structure of a variety of oligomers has been obtained and the structures present in each of the two types of resins related to the reagent used either formaldehyde or furfural. The oligomers type and species distribution appeared rather different for each case. Comparison of a P-Furan resin with a Mimosa tannin-Furan resin showed some differences. This latter shows a greater proportion of self-condensed fuanic oligomers due to the manner in which it is prepared starting from furfuryl alcohol. Several different Tannin-Furan oligomers were also observed by MALDI TOF analysis.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/190
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 99-104
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 99-104
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/190/173
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/191
2017-09-20T17:28:06Z
MCT:art.
driver
Alternative Compositions Of Oriented Strand Boards (Osb) Made With Commercial Woods Produced In Brazil
Bufalino, Lina
Ribeiro Corrêa, Andrea Aparecida
Aparecida de Sá, Vânia
Marin Mendes, Lourival
Amarante Almeida, Natália
Dordenoni Pizzol, Vinnicius
compression ratio
eucalyptus grandis x urophylla
hardwoods
mechanical properties
physical properties
pinus oocarpa
toona ciliata
This work aimed to investigate the feasibility of using and mixing Toona ciliata, Eucalyptus grandis/urophylla and Pinus oocarpa woods in OSB production. Three one-species and four mixed-species combinations were compared. Layer structure varied by positioning different wood species in the surface and core of the panels. Phenol-formaldehyde (PF) adhesive was applied at 9% for all OSB panels. Three-layer mats with mass proportion of 25/50/25% for surface/core/surface were produced. Pressing time was 8 min, under a 4 MPa pressure and temperature of 180 ˚C. Physical and mechanical properties were evaluated and compared to EN (300) commercialization standard. Most OSB panels did not fully attain such requirements. OSB panels made with Eucalyptus grandis/urophylla and Pinus oocarpa woods have potential to be commercialized as OSB/1 and OSB/2 types, respectively. Among panels made with T. ciliata wood, those produced with this species in the surface and Eucalyptus grandis/urophylla wood in the core met the requirements established for OSB/1 commercialization. Eucalyptus wood has great potential to substitute Pinus wood in OSB production. The utilization of T. ciliata wood for OSB production decreased mechanical performance, but remarkably enhanced water resistance properties.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/191
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 105-116
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 105-116
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/191/174
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/192
2017-09-20T17:28:06Z
MCT:art.
driver
Mejoramiento De La Productividad En Una Industria Maderera Usando Incentivo Remunerativo
Pino-Pinochet, Patricio
Ponce-Donoso, Mauricio
Avilés-Palacios, Carmen
Vallejos-Barra, Óscar
improshare
radiata pine
remanufacture lumber mill
salary policy
wage incentive
incentivo laboral
industria remanufacturera
pino radiata
política de remuneraciones
Se estudió el efecto en la productividad de la elaboración de blanks a partir de la implementación de un modelo de incentivo salarial del tipo Improshare, dirigido al personal de una empresa chilena de remanufacturado de maderera que produce molduras y marcos de puerta (ayudante, operador medio y operador máster), para lo cual se compararon dos periodos de tiempo, antes (19 meses) y después (21 meses) de la implementación de la política de incentivo. Los resultados mostraron diferencias estadísticamente significativas en la productividad lograda entre periodos que superó el 10%. Se midió el beneficio promedio de la remuneración de los trabajadores, que llegó a más del 10% y el ahorro de la empresa llegó al 4,6% de la unidad monetaria definida, sin que se haya visto afectada la tasa de accidentabilidad. Lo anterior refuerza lo señalado por diferentes autores que concuerdan que este tipo de herramientas contribuye a mejorar la productividad del proceso e incrementar el salario del trabajador. Su implementación como política salarial en la industria maderera, aporta significativamente a los desafíos de una organización por mantenerse competitiva, así como mejorar la remuneración del trabajador en base a una relación de beneficio mutuo con la empresa. AbstractWe studied the effect on productivity resulting in the blanks elaboration from the implementation of a salary incentive model of Improshare type for staff working group in a sawnwood mill company producer remanufacturing moldings and door frames (assistant, operator and operator master), for which two time periods were compared, before (19 months) and after (21 months) of incentive policy implementation. The results show statistically significant differences in the productivity between periods, of more than 10%. The average benefit of the workers compensation was measured, it reached more than 10% and the savings to the company reached 4,6% of defined monetary unit, without affecting the accident rate. This reinforces the point made by different authors that this kind of tool improves the productivity of the process and increases wages. Its implementation as compensation policy in the lumber industry contributes significantly to the challenges that an organization faces to remain competitive and improve workers compensation based on a mutually beneficial relationship with the company.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/192
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 117-128
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 117-128
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/192/175
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/193
2017-09-20T17:28:06Z
MCT:art.
driver
Physico-Mechanical Properties Of Plywood Bonded By Nano Cupric Oxide (Cuo) Modified Pf Resins Against Subterranean Termites
Gao, Wei
Du, Guanben
mechanical properties
nano cupric oxide
phenol-formaldehyde resin
physical properties
plywood
termite resistance
Nano CuO and alkane surfactant modified phenol Formaldehyde (PF) resins were applied to manufacture plywood, and physical and mechanical properties, such as shear strength, tensile property, modulus of rupture (MOR), modulus of elasticity (MOE), as well as termite resistance were evaluated. The result showed that the combination of nano CuO and alkane surfactantplayed different effect on tensile strength, and especially on shear strength as evaluated at different test conditions. But it was confirmed to improve the water resistance of treated plywood specimens. The introduction of nano CuO and surfactant did not influence the flexural properties significantly by statistically. The result of termite tests indicated that the weight loss decreases gradually from 31,12% to less than 10,37%, and the mortality increases from 32,61% to higher than 86,35%. And the AWPA rating also rises from 4 (very severe attack) to 7 (moderate attack).
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/193
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 129-138
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 129-138
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/193/176
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/194
2017-09-20T17:28:06Z
MCT:art.
driver
Estudio Comparativo Entre Fluorescencia De Rayos-X Y Reflectancia Difusa De Infrarrojos Cercanos Para La Determinación De La Retención En Madera Impregnada Con Arseniato De Cobre Cromatado
Baettig-Palma, Ricardo
Cornejo-Troncoso, Jorge
Salas-Maureira, Marina
Tapia-Sanhueza, Jaime
atomic absorption
chromated copper arsenate
near-infrared diffuse reflectance
treated wood
x-ray fluorescence
absorción atómica
arseniato de cobre cromatado
fluorescencia de rayos x
madera impregnada
reflectancia difusa infrarroja
Se realizó un análisis comparativo de la precisión de los resultados en la determinación de la retención de óxidos de cobre, cromo y arsénico en madera impregnada con arseniato de cobre cromatado entre fluorescencia de rayos X y espectrometría de reflectancia difusa de infrarrojos cercanos. Los resultados de la calidad de las predicciones fueron comparados entre sí y con valores de retención obtenidos experimentalmente por método gravimétrico, absorción atómica y por cenizas resultantes de su calcinación. Los resultados del coeficiente de determinación del análisis de regresión entre la intensidad de fluorescencia de rayos X de las líneas K-Alpha y entre el espectro de reflectancia difusa de infrarrojos con respecto a la retención medida por métodos convencionales se encontraron en un rango de 0,909 a 0,986. Los resultados obtenidos pueden ser considerados aceptables para fines predictivos o incluso adecuados para propósitos de control de calidad. A su vez, al ser comparados por sus niveles de error de estimación, estos resultados fueron mejores que los obtenidos por otros estudios similares. AbstractThis paper evaluated the precision of predictions for chromated copper arsenate preservative retention in wood using X-ray fluorescence and near infrared diffuse reflectance. The quality of the predictions were compared with each other and with retention values obtained experimentally by gravimetric method, atomic absorption and total ash content. Coefficients of determination between the K-Alpha fluorescence intensities and near infrared diffuse reflectance with regard to conventional methods were between 0,909 and 0,986. The results can be considered acceptable for predictive purposes or even good for quality control purposes. In turn, the prediction errors were better than obtained by several studies.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/194
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 139-150
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 139-150
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/194/177
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/195
2017-09-20T17:28:06Z
MCT:art.
driver
Compression And Flexural Properties Of Finger Jointed Mango Wood Sections
Kishan Kumar, V.S
Sharma, C.M
Gupta, Sachin
bending
compression
finger joint
mango wood
poly vinyl acetate
urea-formaldehyde
In this paper, an attempt was made to assess the effectiveness of finger jointing in utilising mango wood sections for various end uses like furniture. The study was based on the estimation of Modulus of elasticity and Modulus of rupture under static bending and Maximum Crushing Stress and Modulus of elasticity under compression parallel to grain of finger jointed sections and comparing them with the values measured for clear wood sections from the same lot. For joining the sections, the Poly Vinyl Acetate and Urea Formaldehyde adhesives were used. It was found that the Modulus of elasticity of the sections joined by either adhesive showed significantly better values than that of unjointed clear wood sections. The Modulus of rupture values of sections joined with Urea Formaldehyde were similar to those of unjointed clear wood sections. However, sections jointed with Poly Vinyl Acetate adhesive exhibited lower Modulus of rupture. Under compression, the parameters of the jointed sections joined with either adhesive were either similar or better than those of the unjointed clear wood sections. The study demonstrates the utility of finger jointing of mango wood sections for furniture parts especially with the Urea Formaldehyde adhesive.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/195
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 151-160
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 151-160
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/195/178
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/196
2017-09-20T17:28:06Z
MCT:art.
driver
Effect Of Albino Ophiostoma Strains On Eucalyptus Nitens Extractives
Coloma, Juana
Reyes, Laura
Navarrete, José
Alarcón, Julio
Delgado, Lilian
Vera, Renato
Ubilla, Priscilla
Vásquez, Karen
Becerra, José
albino fungi
eucalyptus nitens
extractives
pitch
ophiostoma
sitosterol
Wood extractives promote pitch formation during pulp and paper manufacturing. To date, this problem has been controlled by extended storage of the chips and/or chemical additives. Biotreatment of the wood prior to pulping provides an alternative that not only decreases the negative impact of the extractives but may also improve the kraft pulping efficiency. This initiative seeks to verify the quantity and chemical composition of Eucalyptus nitens wood extractives following biotreatment with three albino fungi species (Ophiostoma floccosum, Ophiostoma piceae and Ophiostoma piliferum). Eucalyptus nitens wood chips were sprayed with spore suspensions of Ophiostoma piliferum, Ophiostoma piceae and Ophiostoma floccosum albino strains (1 × 108 spore concentration). After 7 and 21 days of fungal treatment, the extractive content was determined via Soxhlet extraction with an 80:20% n-hexane:ethyl acetate solvent mixture. The Ophiostoma floccosum F1A94, Ophiostoma piliferum F2D8 and Ophiostoma piceae F2A68 strains proved to be most capable of bioreduction with reductions of 35.1%, 33.2% and 29.3%, respectively. The chemical composition of the extract was analyzed via gas chromatography coupled with mass spectrometry, which demonstrated that most of the tested strains could reduce the β-sitosterol content.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/196
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 161-170
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 161-170
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/196/179
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/197
2017-09-20T17:28:06Z
MCT:art.
driver
Evaluation Of Physical And Mechanical Properties Of Wild Cherry Wood Heat-Treated Using The Thermowood Process
Korkut, Süleyman
Aytin, Ayhan
anti-swelling-efficiency
compression strength
janka-hardness
modulus of elasticity
modulus of rupture
prunus avium
The aim of this study is to determine the change of some physical properties (oven-dry density, weight loss, swelling and anti-swelling efficiency) and mechanical properties (compression strength parallel to grain, bending strength, modulus of elasticity in bending, janka-hardness (cross-section, radial, tangential), impact bending strength and tension strength perpendicular to grain) of wild cherry woods after heat treatment under different durations. Specimens are exposed to temperature levels of 212 °C for time spans of 1,5 and 2,5 h. Based on the findings in this study, the results showed that oven-dry density, swelling, compression strength parallel to grain, bending strength, modulus of elasticity in bending, janka-hardness (Cross-section, Radial, Tangential), impact bending strength and tension strength perpendicular to grain values decreased with increasing treatment time.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/197
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 171-178
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 171-178
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/197/180
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/198
2017-09-20T17:28:06Z
MCT:art.
driver
Mechanical Properties Of Chemically Modified Portuguese Pinewood
B.Lopes, Duarte
Mai, Carsten
Militz, Holger
compression
impact bending strength
mechanical
modulus of elasticity
modulus of rupture
shear
stiffness stabilization efficiency
strength
tensile
To turn wood into a construction material with enhanced properties, many methods of chemical modification have been developed in the last few decades. In this work, mechanical properties of pine wood were chemically modified, compared and evaluated.Maritime pine wood (Pinus pinaster) was modified with four chemical processes: 1,3-dimethylol-4,5-dihydroxyethyleneurea, N-methylol melamine formaldehyde, tetra-alkoxysilane and wax. The following mechanical properties were assessed experimentally: Modulus of elasticity measured statically, stiffness stabilization efficiency in different climates (30 and 87% of relative humidity), modulus of rupture, work maximum load, impact bending strength, compression, tensile and shear strength at indoor conditions (65% of relative humidity).In both types of active principle of modification, cell wall or lumen fill, no significant changes on the bending stiffness (modulus of elasticity) were found. In the remaining properties analysed significant changes in the modified wood-material took place compared to unmodified wood control:- Cell wall modification was the most effective method to achieve high stiffness stabilization efficiency (up to 60%) and also increased compression strength (up to 230%). However, modulus of rupture, tensile, shear and the impact bending strength were reduced by both resins, but in a varying extent, where the N-methylol melamine formaldehyde endured less reduction than 1,3-dimethylol-4,5-dihydroxyethyleneurea resin. In the latter, reduction up to 60% can take place.- In the lumen fill modification: tetra-alkoxysilane has no effect in the mechanical properties. Although, a slight increase in shear strength parallel to the grain was found. Wax specimens have shown a slight increase in bending strength, compression, tensile and shear strength as well as in the absorption energy capacity.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/198
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 179-194
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 179-194
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/198/181
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/199
2017-09-20T17:28:06Z
MCT:art.
driver
Influencia De La Granulometria De La Muestra En La Discriminación De Especies De Salix Por Infrarrojo Cercano
Nisgoski, Silvana
Elita Carneiro, Mayara
Bolzon de Muñiz, Graciela Inés
near infrared spectroscopy
particle size sample
willow
espectroscopía de infrarrojo cercano
granulometría de la muestra
mimbre
En Brasil, las especies cultivadas del género Salix son de gran importancia en la artesanía, con propiedades diferentes en relación a la maleabilidad y resistencia. Este trabajo tuvo como objetivo aplicar la espectroscopía de infrarrojo cercano (FT-NIR) para la discriminación de cuatro especies de Salix, comparando muestras de materia maciza y partículas. Las muestras de Salix viminalis, Salix x rubens, Salix purpurea y Salix sp., fueron seleccionadas en siete sitios en la región del Valle del Río Canoas, Estado de Santa Catarina (Brasil). Los espectros de absorción se obtuvieron en FT-NIR espectrofotómetro (Bruker Tensor 37). La forma y la granulometría de las muestras de Salix spp. tienen influencia en la discriminación de las especies por FT-NIR. La técnica tuvo mayor capacidad de distinción para la granulometría de menor tamaño. AbstractIn Brazil, the cultivated species of genus Salix have great importance in crafts, with different properties in relation to malleability and resistance. This paper aimed to apply near infrared spectroscopy (FT-NIR) for discrimination of four Salix species, comparing solid sample and particulate material. Samples from Salix viminalis, Salix x rubens, Salix purpurea and Salix sp. were collected in seven sites in the region of Rio Canoas Valley, Santa Catarina State, Brazil. It was obtained absorbance spectra in FT-NIR (Bruker Tensor 37). The shape and particle size of Salix spp. influenced the discrimination of species by near infrared. The technique had a more efficient distinction for smaller particle size samples.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/199
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 195-204
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 195-204
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/199/182
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/200
2017-09-20T17:28:06Z
MCT:art.
driver
Effects Of Nano-Clay On Biological Resistance Of Wood-Plastic Composite Against Five Wood-Deteriorating Fungi
Bari, E.
Taghiyari, H. R.
Schmidt, O.
Ghorbani, A.
Aghababaei, H.
fungal degradation
nano-clay
populus nigra
water absorption
wood-plastic composite
Effects of nano-clay on weight loss of wood-plastic composites (WPC) by five fungi were studied. Nanoclay particles of 20 to 50 nm size were applied at 2, 4, and 6% WPC of 0,90 g/cm3 density. The white-rot fungi Physisporinus vitreus, Pleurotus ostreatus and Trametes versicolor as well as the brown-rot species Antrodia vaillantii and Coniophora puteana were used. Mass loss tests were conducted according to the European standard. The highest (3.2%) and lowest (0,2%) mass losses were produced by T. versicolor and P. vitreus in the control and 6%-nanoclay treatments, respectively. Obviously the weight loss of WPC depends on the fungus species. Although weight losses were extremely low, nano-clay considerably inhibited the growth of wood-deteriorating fungi. Mass loss correlated with water absorption.
Universidad del Bio-Bio
2015-01-12
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/200
Maderas-Cienc Tecnol; Vol. 17 No. 1 (2015); 205-212
Maderas-Cienc Tecnol; Vol. 17 Núm. 1 (2015); 205-212
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/200/183
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1142
2017-09-20T17:30:27Z
MCT:art.
driver
Surface roughness of heat treated Eucalyptus grandis wood
Pires de Moura Palermo, Gilmara
de Figueiredo Latorraca, João Vicente
de Moura, Luiz Fernando
Nolasco, Adriana Maria
Monteiro de Carvalho, Alexandre
Garcia, Rosilei Aparecida
heat treatment
wood machining
surface quality
This study aimed to evaluate surface roughness of heat treated Eucalyptus grandis wood after peripheral planning and sanding performed in directions to the grain and against the grain. For machining tests, workpieces were collected from two different regions in the radial direction, as follows: internal, nearby the pit; external, nearby the bark. Heat treatment was carried out by heating samples at a maximum temperature of 190ºC, with total treatment duration of 390 minutes. Heat treated and control samples underwent peripheral planning and sanding tests. The quality of machined surfaces was assessed by means of roughness average (Ra) measurements across and along the grain orientation. Results indicated significant differences in surface roughness as a function of machining feed direction, sandpaper grit size, and heat treatment. Surface roughness has not shown any difference in the radial direction.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1142
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 3-12
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 3-12
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1142/1094
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1143
2017-09-20T17:30:27Z
MCT:art.
driver
Density, calorific value and cleavage strength of selected hybrid Eucalypts grown in uganda
Turinawe, Harold
Mugabi, Paul
Tweheyo, Mnason
hybrid eucalypts
density
calorific value
cleavage resistance
Uganda
This study was done to ascertain the suitability of Uganda’s clonal eucalypts for fuelwood. The objectives were to determine: (i) basic density (BD); (ii) calorific value (CV); and (iii) cleavage resistance (CLR) parallel to the grain of widely adopted clones i.e. GU7, GU8, GC540, GC550 and GC796 and to compare these properties with those of their parent materials; i.e. Eucalyptus grandis, Eucalyptus cammaldulensis, and Eucalyptus urophylla. Tests were done according to BS373(1957) and ASTM:E870-82(2006) procedures. Clone GC540 showed the highest BD (664kg/m3), GU7 had the highest CV (17800kJ/kg), GU7 and GC540 had higher values for CLR (20N/mm). BD and CLR means were in-between parent material means for GC clones. All clones had lower values of CV compared to parent materials. It was concluded that clonal wood at 6-7 years remains a viable alternative for fuelwood due to high volume increment per unit time and moderate CLR values to allow ease of splitting.
Universidad del Bio-Bio
2015-06-02
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1143
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 13-24
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 13-24
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1143/1095
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1144
2017-09-20T17:30:27Z
MCT:art.
driver
Efecto de la temperatura de termotratamiento en el comportamiento eléctrico de la madera de Pino radiata
Fernández-Golfín, JI.
Conde García, M.
Fernández-Golfín, JJ.
Hermoso, E.
Cabrero, JC.
thermal modified timber
electrical conductivity of timber
pinus radiata
madera termotratada
conductividad eléctrica de la madera
En el presente trabajo se analiza el efecto de la temperatura del termotratamiento sobre la conductividad eléctrica de la madera de pino radiata. Sobre probetas de madera de pino radiata de procedencia País Vasco (España), termotratada a 190ºC y 210ºC por el método Thermowood así como sobre piezas testigo de la misma especie, procedencia y dimensiones, acondicionadas todas ellas hasta masa constante a 20ºC/40%HR, 20ºC/65%HR y 20ºC/90%HR se evaluó la resistencia eléctrica (longitudinal y transversal) y, posteriormente, se ajustó el modelo Samuelsson para modelizar en cada tipo de material la relación humedad de la madera-resistencia eléctrica. Se concluye que la temperatura empleada en el tratamiento térmico de la madera afecta no sólo a la humedad de equilibrio sino, también, a su conductividad eléctrica, siendo máximo este efecto en el tratamiento efectuado a 210ºC. AbstractThis paper analyzes the effect of heat treatment temperature on the electrical conductivity of radiata pine wood. On specimens of radiata pine of the Basque Country provenance (Spain), heat treated at 190°C and 210°C by the method Thermowood as well as not treated matched samples, conditioned up to constant mass at the standard conditions of 20°C/40%; 20°C/65% and 20°C/90% RH the electrical resistance (longitudinal and transverse) was measured and a Samuelsson model fitted to describe the relationship between the electrical resistance and moisture content of each material. From the data is concluded that the temperature employed in the thermal treatment timber not only affects equilibrium moisture content of wood but also to its electrical conductivity, being this effect maximum in the processing performed at 210°C.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1144
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 25-36
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 25-36
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1144/1096
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1145
2017-09-20T17:30:27Z
MCT:art.
driver
Efectos del contenido de harina de corteza y madera de Pinus radiata sobre la biodegradación acelerada de compuestos madera-plástico
Moya-Villablanca, Cristian
Oses-Pedraza, Rómulo
Poblete-Wilson, Hernán
Valenzuela-Hurtado, Luis
composites
accelerated decay
white and brown-rot-fungi
bark and wood flours
compuestos
biodegradación acelerada
harina de madera y corteza
Se evaluaron distintas formulaciones de compuestos fabricados en base a polietileno de baja densidad reciclado (PEr) y harinas tanto de corteza como de madera de Pinus radiata, mediante ensayos estandarizados de biodegradación acelerada. Los compuestos tipo Wood Plastic Composites (WPCs) fueron obtenidos mediante moldeo por inyección sin aditivos químicos, a partir de las siguientes mezclas entre PEr-harina en distintas proporciones: 100-0%, 80-20%; 60-40% y 40-60 %. Los ensayos de biodegradación acelerada fueron realizados de acuerdo a la norma ASTM D-2017, bajo condiciones controladas durante 3 meses, usando dos tipos de hongos degradadores, un hongo de pudrición café (Gloeophyllum trabeum) y por un hongo de pudrición blanca (Pleurotus ostreatus). Al término del período de biodegradación se determinó el porcentaje de pérdida de peso de cada tipo de compuesto. Los resultados indicaron que la pérdida de peso de los compuestos aumenta conforme aumenta la proporción de harina en la mezcla, siendo significativamente mayor con el hongo de pudrición café (Gt), más que con el hongo de pudrición blanca (Po). Independientemente del tipo de hongo utilizado, la harina de corteza presentó mayor susceptibilidad a la degradación en comparación con la harina de madera. AbstractComposites of wood and bark of Pinus radiata–recycled low polyethylene (RLPE) were submitted to accelerated decay using white and brown rot fungi. These WPCs were obtained by injection molding without chemical additives at proportions: 100-0%, 80-20%, 60-40% and 40-60%. Accelerated decay tests were conducted according to ASTM D-2017-05, using a brown rot fungus (Gloeophyllum trabeum) and a white rot fungus (Pleurotus ostreatus), during 3 months, under controlled conditions. After that, percentage of weight loss of each type of composite was determined. The results shown that the biodegradation of composites increased with increasing of flour in the mixture being higher in brown rot fungus (Gt) than in white rot fungus (Po) treatment. Bark flour had higher susceptibility to biodegradation in comparison with the wood flour.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1145
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 37-48
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 37-48
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1145/1097
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1146
2017-09-20T17:30:27Z
MCT:art.
driver
Effects of nanosilver-impregnation and alfalfa-intercropping on fluid transfer in downy black poplar wood
Reza Taghiyari, Hamid
alfalfa
specific gas permeability
diameter increment
intercropping
populus nigra betulifolia
vaporized chamber
Effects of alfalfa-intercropping and nanosilver-impregnation were studied here on the specific gas permeability of 10-year old Populus nigra var. betulifolia. Specimens were impregnated with a 200 ppm aqueous dispersion of silver nanoparticles under 250 kPa pressure; the results were then compared with the un-impregnated specimens. The size range of silver nanoparticles was 10 to 80 nm. After the initial measurement, specimens were kept in vaporized chamber for six months (43±2°C, and 80±3% relative humidity); permeability was measured every month. Results showed that maximum specific longitudinal gas permeability was observed in the nanosilver-impregnated inner-wood specimens of the treatment with alfalfa (1614,4 × 10-13 m3 m-1), and minimum permeability was found in the un-impregnated outer-wood specimens of the treatment without alfalfa (491,7 × 10-13 m3 m-1) before the vaporization. Vaporized chamber made permeability decrease permeability at the first phases because of the absorption of water vapors and the consequent swelling; however, due to the proliferation of pits and perforation plates by fungi and molds, permeability was eventually increased. Antibacterial property of silver did not significantly decrease the growth of molds and fungi in the nanosilver-impregnated specimens.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1146
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 49-62
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 49-62
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1146/1098
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1147
2017-09-20T17:30:27Z
MCT:art.
driver
Leaching and decay resistance of alder and pine wood treated with copper based wood preservatives
Temiz, Ali
Alfredsen, Gry
C. Yildiz, Umit
D. Gezer, Engin
Kose, Gaye
Akbas, Selcuk
Yildiz, Sibel
copper based wood preservatives
wood protection
alder
scots pine
leaching of copper
The objective of this study was to determine the leaching and decay resistance of Alder (Alnus glutinosa subsp. barbata) and Scots pine (Pinus sylvestris) wood samples treated with copper based preservatives. Samples were treated with CCA, ACQ, Tanalith E and Wolmanit with different concentrations. Scots pine samples were exposed the mini-block test against brown rot fungi (Poria placenta) and Coniophora puteana while alder wood samples were tested against brown rot fungi (Coniophora puteana) and white rot fungi (Coriolus versicolor). Regarding to leaching test, treated samples were impregnated with 300 ml of distilled water and after 6, 24, 48 and thereafter at 48-hour intervals, the leachate was removed and replaced with fresh distilled water according to AWPA E11. Samples of each leachate were collected and retained for copper analysis. Amount of copper released from treated wood during the leaching test was chemically analyzed with Atomic Absorption spectroscopy. Perchloric acid procedure for the digestion of wood was used according to AWPA A7-97. The amount of copper component (Qd), the cumulative quantities leached (Qc) and the average daily fluxes (FLUX) were calculated. Results shows that CCA treated samples release less copper compared to other copper based preservatives used in this study. Highest mass losses were obtained from the leached samples treated with 1% of ACQ-2200 against decay fungi.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1147
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 63-76
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 63-76
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1147/1099
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1148
2017-09-20T17:30:27Z
MCT:art.
driver
Determinación experimental de valores característicos de resistencia para Guadua angustifolia
Luna, Patricia
Lozano, Jorge
Takeuchi, Caori
amboo
guadua angustifolia
mechanical properties
elastic modulus
characteristic value
bambú
propiedades mecánicas
módulos elásticos
valor característico
Para el diseño de estructuras que utilizan como material estructural principal el bambú Guadua angustifolia, es necesario conocer los valores característicos de sus propiedades mecánicas y módulos elásticos. En este artículo se presenta la metodología experimental utilizada para la determinación de los valores característicos de resistencia mecánica a flexión longitudinal, compresión, corte y tracción paralela a la fibra, torsión, y comprensión perpendicular a la fibra y módulos elásticos de la Guadua angustifolia. Se realizaron ensayos en probetas tomadas de la parte inferior, media y superior de culmos de guaduas provenientes de tres departamentos diferentes de Colombia. Se encontraron los valores característicos de la resistencia a compresión, tensión y corte paralelos a la fibra, flexión longitudinal, torsión y compresión perpendicular así como valores de módulo de elasticidad longitudinal y circunferencial. AbstractFor the design of structures built with bamboo Guadua angustifolia as structural material it is necessary to know the characteristics values of its mechanical properties and elastics modulus. This article shows the experimental methodology used in the determination of characteristics values for bending, compression, shear and tensile parallel to fiber, torsion, compression perpendicular to fiber and elastics modulus for Guadua angustifolia. Tests were performed in samples taken from the bottom, middle and upper parts of culms of bamboos from three different areas of Colombia. Characteristic values of compression, tension and shear parallel to the fiber, bending, torsion and perpendicular compression strengths were found. Also the elastic longitudinal modulus and the circumferential modulus were determined.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1148
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 77-92
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 77-92
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1148/1100
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1149
2017-09-20T17:30:27Z
MCT:art.
driver
Prediction of bending properties for beech lumber using stress wave method
Guntekin, Ergun
Ozkan, Serhat
Yilmaz, Tugba
fagus orientalis
bending properties
stress wave
In this study; bending properties of beech wood (Fagus orientalis) were predicted using stress – wave method and compared with static bending tests. First, lumbers which were different in length and cross section were weighed and dimensions were measured. Then, moisture contents were obtained via moisture meter. By using the density, moisture, and dimensions of the samples in MTG Timber Grader device, dynamic modulus of elasticity values were determined. And then, samples were subjected to 3 point bending test. Modulus of elasticity and bending strengths were calculated using load – deformation curves. Regression models were developed to interpret relationships between dynamic modulus elasticity and bending properties. Results showed that there is a high regression coefficient (0,86) between dynamic modulus of elasticity and static modulus of elasticity. Regression coefficient between dynamic modulus of elasticity and static bending strength was measured as (0,72) and regression coefficient between static modulus of elasticity and static bending strength was measured as (0,74). Results indicate that bending properties of beech wood lumber can be predicted using stress wave method.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1149
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 93-98
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 93-98
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1149/1101
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1150
2017-09-20T17:30:27Z
MCT:art.
driver
Some mechanical properties of plywood produced from eucalyptus, beech, and poplar veneer
Cihad Bal, Bekir
Bektaş, İbrahim
plywood
modulus of elasticity
modulus of rupture
specific modulus of elasticity
specific modulus of rupture
In this study, we determined the flexural properties and tensile shear strength of five-ply plywood panels produced with eucalyptus (Eucalyptus grandis), beech (Fagus orientalis), and hybrid poplar (Populus x euramericana) using urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF) and phenol-formaldehyde (PF) adhesives. Flexural properties were tested on both parallel and perpendicular to grain samples. Tensile shear-strength tests were conducted on four glue lines of the plywood panels, and the effects of species of trees, type of adhesives, and direction of load were determined. The results of variance analyses showed that the effects of species of trees, direction of load, and type of adhesive on flexural properties were significant, but it was determined by specific flexural properties that the effect of the type of adhesive was based on the density of the plywood. In addition, as a result of findings, it can be said that specific mechanical properties may be a good predictor for comparative studies.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1150
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 99-108
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 99-108
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1150/1102
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1151
2017-09-20T17:30:27Z
MCT:art.
driver
Marine borers resistance of chemically modified portuguese wood
Barroso Lopes, Duarte
Mai, Carsten
Militz, Holger
chemical modification
resistance
EN 275
limnorids
marine borers
pinus pinaster
teredinids
use class 5
This study deals with the role of hardness and chemical toxicity in the resistance of pinewood to marine borers.Portuguese wood Maritime pine (Pinus pinaster) was modified with 1,3-dimethylol 4,5-dihydroxy ethylene urea (DMDHEU), methylated methylol melamine (MMF), tetraethoxysilane (TEOS) and two types of wax. In addition, for comparative purposes, different control species, Ipê, Beech and Blue Gum and CCA treated pine were included.All specimens were exposed over 2 years in sea (Porto, north of Portugal). Three inspections were performed after exposure (6, 12 and 24 months). The influence of type and level of modification as well as hardness was evaluated.As results: Specimens modified with resin have shown slight or trace attack by Teredinids in DMDHEU with low level of modification (10% of weight percent gain, WPG); MMF resin with high and low level of modification (25% and 10% of WPG) have shown trace to moderate attack, respectively.With the TEOS and wax impregnated wood which fill the cell lumens no significant difference in marine borers attack was found as compared to unmodified control specimens, despite the increased hardness.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1151
Maderas-Cienc Tecnol; Vol. 16 No. 1 (2014); 109-124
Maderas-Cienc Tecnol; Vol. 16 Núm. 1 (2014); 109-124
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1151/1103
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1152
2017-09-20T17:30:06Z
MCT:art.
driver
Wood thermodegradation: experimental analysis and modeling of mass loss kinetics
Pétrissans, A.
Younsi, R.
Chaouch, M.
Gérardin, P.
Pétrissans, M.
heat treatment
modeling
reaction kinetics
thermodegradation
wood
In this study, heat treatment was carried out in a relatively low temperature (230˚C). Mass loss kinetics was studied using equipment, specially conceived to measure sample’s mass during the thermal treatment. Laboratory experiments were performed for heating rates of 1˚C min-1. Mathematical model for kinetics of pyrolysis process was used and validated. During the pyrolysis of dry wood samples under inert atmosphere, measurements of temperature distribution and dynamic weight loss were performed. Five different wood species Fagus sylvatica (Beech), Populus nigra (Poplar), Fraxinus excelsior (Ash), Pinus sylvestris (Pine) and Abies pectinata (Silver Fir) were investigated. The unsteady-state mathematical model equations were solved numerically using the commercial package Femlab 2.0. A detailed discussion of the computational model and the solution algorithm is given. The validity of different model assumptions was analyzed. Experimental results were compared with those calculated by the model. Acceptable agreement was achieved.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1152
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 133-148
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 133-148
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1152/1104
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1153
2017-09-20T17:30:06Z
MCT:art.
driver
Oak wood inhabiting fungi and their effect on lignin studied by uv microspectrophotometry
Karami, Leila
Fromm, Jörg
Koch, Gerald
Schmidt, Olaf
Schmitt, Uwe
oak wood degradation
fungi
rDNA-ITS sequencing
lignin content
UV-microspectrophotometry
Decayed-wood samples were collected from a naturally-infected bridge made of Quercus robur. Fruiting bodies of the white-rot basidiomycetes Hymenochaete rubiginosa and Stereum hirsutum were sampled. The white-rot fungus Fuscoporia ferrea and the secondary saprobiont Mycena galericulata were identified from the rotten wood by means of rDNA-ITS sequencing. The topochemistry of lignin degradation within individual cell-wall layers was determined by cellular UV-microspectrophotometry (UMSP) at 278 nm wavelength. Increased delignification occurred in compound middle lamella regions (CML), secondary wall layers of fibres (S2), longitudinal and ray parenchyma cells as well in vessels. The highest lignin content at initial and medium decay was recorded in the CML, whereas in advanced decay secondary wall layers of the vessels exhibited the highest content of residual lignin. In all stages of degradation, the S2 layers of fibres had the lowest lignin amount.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1153
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 149-158
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 149-158
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1153/1105
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1154
2017-09-20T17:30:06Z
MCT:art.
driver
Study on preparation and properties of phenol-formaldehyde-chinese fir liquefaction copolymer resin
Lin, Ruihang
Sun, Jin
Yue, Chao
Wang, Xiaobo
Tu, Dengyu
Gao, Zhenzhong
chinese fir-based adhesive
formaldehyde
bonding properties
FT-IR
DSC
A new zero-waste and zero-pollution composite adhesive labeled Chinese fir-based adhesive for exterior plywood was synthesized by blending alkaline Chinese fir (Cunninghamia lanceolata) liquid with a small amount of phenol-formaldehyde (PF). The free phenol and free formaldehyde content of the Chinese fir-based adhesive were sharply decreased compared to normal PF resin by more than 50%. The synthetic adhesive show with excellent water resistance and environmental friendliness, which had a 28h boil-dry-boil wet bonding strength of 1,73MPa according to standard JIS K6806-2003 and a formaldehyde emission of 0,045mg/L according to standard JIS A1460-2003. The structural properties and their thermal properties of cured adhesives were evaluated using Fourier transform infrared (FT-IR) and differential scanning calorimetry (DSC). The FT-IR analysis confirmed the expected chemical structure as the Chinese fir liquid reacted with formaldehyde and phenol which occurred at the wavenumbers of 1733, 1698, 1652cm-1 and 1077, 1048 cm-1. Although the DSC results indicated that the Chinese fir-based adhesive’s curing need higher temperature than the control PF resin, the higher curing temperature hardly cripple the availability of Chinese fir-based resin in the plywood production.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1154
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 159-174
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 159-174
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1154/1106
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1155
2017-09-20T17:30:06Z
MCT:art.
driver
Wood-based panels industry in turkey: future raw material challenges and suggestions
Tezcan Yıldırım, Hasan
Candan, Zeki
Korkut, Süleyman
wood based panels industry
forest industry
forest products
forest products policy
forest villagers
World production of wood based panel has grown from 63,1 million cubic meters in 2005 to 75,5 million m3 in 2009, a 12 million m3 rise in production. China is the world’s largest wood based panel’s manufacturer. The Turkish wood based panels industry has shown a tendency of fluctuating during this time. Turkey, as the world’s 4th largest producer of wood based panels, is an important contributor to the industry. Turkey has made great strides in the last 20 years in the forest products industry. Both the development of new materials and techniques of domestic and international market demand have played a decisive role. Turkey’s wood panel production has gone from 100000 m3 in the early 2000s, to 5,5 million m³ of production in 2010. The sector’s total production capacity is approximately 9 million m³. The results obtained thus far indicate that the Turkish wood based panel industry demand for raw material is not being met by the GDF’s chip wood fiber production. Where the raw material supply problem in the industry, as well as the problems encountered in the forest and on the basis of the villagers living adjacent to, not to the time of product problems related to storage and transportation of raw materials and other related problems are bottlenecks. We examine problems related to the provision of raw materials and raw materials research, the need for future estimates of the level at which the world and close to the periphery countries will be examined, wood composite panel production and trade policy recommendations will be developed.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1155
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 175-186
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 175-186
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1155/1107
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1156
2017-09-20T17:30:06Z
MCT:art.
driver
Free shrinkage of wood determined at the cellular level using an environmental scanning electron microscope
Almeida, Giana
Huber, Françoise
Perré, Patrik
cell wall thickness
cell shape
image correlation
MeshPore
softwood
Norway spruce
The shrinkage at the cellular level was determined in the transverse plane of wood using an environmental scanning electron microscope (ESEM). The whole procedure is based on pairs of images grabbed with the same imaging conditions (magnification, working distance, voltage) without removing the sample from the chamber: one image collected at saturated conditions (1067 Pa, 1°C) and the other at air-dry state (533 Pa, 16°C). A closed chain of the same reference points chosen from the anatomical markers was defined on both images at the external part of the zone of interest. A custom software program, called MeshPore, allowed the shrinkage coefficients to be extracted from the slight difference of shape between these two chains.Measurements of transverse shrinkage were performed on earlywood and latewood zones from Norway spruce (Picea abies), only normal wood was studied. The interested zones were isolated from the rest of the annual ring with the aid of a microtome blade, insuring the observations to be done under free shrinkage. As additional features, the changes of the cellular morphology and the cell wall thickness were also evaluated thanks to the resolution provided by the ESEM.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1156
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 187-198
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 187-198
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1156/1108
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1157
2017-09-20T17:30:06Z
MCT:art.
driver
Cutting forces by oak and douglas fir machining
Porankiewicz, Bolesław
Goli, Giacomo
grain orientation
multi-factor non-linear statistical dependencies
cutting force
routing
In this work the multi-factor, non-linear dependencies between main (tangential) FC and normal (radial) FN cutting forces upon two machining parameters by up-routing and down-routing wood of Douglas fir (Pseudotsuga menziesii) and Oak (Quercus petraea) were evaluated. The relationships are graphically illustrated and discussed. The obtained data were compared with cutting forces evolution models according to grain orientation from the literature in order to verify if literature statements or models comply with measured data. Evidence of several contradictions was found relative to results from available literature.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1157
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 199-216
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 199-216
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1157/1109
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1158
2017-09-20T17:30:06Z
MCT:art.
driver
Analysis of rigidity loss and deterioration from exposure in a decay test field of thermorectificated eucalyptus grandis wood
Trevisan, Henrique
de Figueiredo Latorraca, João Vicente
Pacheco dos Santos, Angelo Luíz
Grilo Teixeira, Juliana
de Carvalho, Acacio Geraldo
xylophogous
term treatment
protection of wood
The objective was to evaluate the elasticity dynamic modulus reduction (MOEd) and deterioration of E. grandis thermorectificated wood by exposure to environmental weathering. Six trees were used to obtain 14 logs of 2,4m, with seven from external (sapwood) and the others from internal (heartwood) part of the trunk. A total of 84 wood samples of 2,5x 5x 50cm were made, with half from the inner and the other from the external trunk portion. 14 treatments were evaluated with six replicates composed of thermorectificated wood submitted two differents times (2 and 4 hours) and three temperatures (200, 215 and 230˚C). An ultrasound Stress Wave Timer device was used to evaluate MOEd and the mass measured by weighing. Samples remained in the decay test field for ten months, and monthly inspected and recorded to xylophogous organism’s occurrence. At the end of this period MOEd and mass were revaluated. The central portion of wood samples were more deteriorated, with mass losses and stiffness losses ranging from (8-56%) and (18-91%), respectively. Lower values were observed in the wood coming from the external portion, with mass losses and stiffness ranging from (3-10%) and (8-20%), respectively. The thermorectificated wood samples were more damaged by action the termites and less by the action of fungi, compared to controls.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1158
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 217-226
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 217-226
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1158/1110
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1159
2017-09-20T17:30:06Z
MCT:art.
driver
Toxicity potential in the extraneous compounds of white mulberry wood (morus alba)
Se Golpayegani, Aida
Thévenon, Marie-France
Gril, Joseph
Masson, Eric
Pourtahmasi, Kambiz
white mulberry
extractives
decay resistance
toxicity
GC-mass
Reticulitermes flavipes
The health problems amongst musical instrument makers working on the White mulberry (Morus alba), lead to investigate the toxicity potential of wood extractives. Five solvents of different polarity and two methods of extractions were used to ensure a thorough, clear and classified compound removal. The compounds were identified using qualitative GC-mass and the toxicity were determined by studying their effect on termite survival (Reticulitermes flavipes). The results indicated the presence of different compound categories like phenols, higher hydrocarbons, fatty acids, sterols and aromatic components in the extractives. These compounds were not removable by just one solvent and the order of removal was polarity related. The extractives were found toxic towards termites. Resorcinol, which corresponded to the highest proportion of peaks in the GC-mass spectra, has been assigned as the possible compound responsible for the allergic reactions by the artisans.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1159
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 227-238
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 227-238
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1159/1111
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1160
2017-09-20T17:30:06Z
MCT:art.
driver
Antitermitic effects of three wood stain treatments
Tascioglu, Cihat
Budakcı, Mehmet
Yoshimura, Tsuyoshi
wood stain
Coptotermes formosanus
treatment
antitermitic
Potential antitermitic properties of some common wood stains were tested against Coptotermes formosanus. Four different wood species treated with 3 different stain chemicals at the 0,1 kg/m2 retention level were exposed to no-choice termite feeding test in laboratory conditions. Mean mass loses, mortality rates and consumption rates were calculated based on weight changes before and after the test. While the hardwood species (beech and chestnut) tested were unaffected by the treatments, the softwood species tested showed drastically reduced mass losses with some stain treatments. Scots pine and spruce sapwood exhibited significant reductions in mass losses when treated with the chemical stain.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1160
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 239-244
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 239-244
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1160/1112
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1161
2017-09-20T17:30:06Z
MCT:art.
driver
A methodology to select a group of species among 131 tropical (colombian) species for bowed timber applications
Caicedo-Llano, Natalia
tropical wood
colombian species
bowing timber
brosimum utile
ceiba pentandra
dialum guianense
tabebuia rosea
We present a methodology of selecting wood species for architectural purposes, especially when a curved shape is required. First, a mechanical criterion is associated with a morphology, more specifically a characteristic value of stress-strain relation is associated with the attitude of wood for bowing. Second, a filtering is done using data of wood in the green state and in the dry state, and then the wood selection is refined by using relevant criteria related to environment and economic considerations. The following four species are the result of the selection: Sande or Guaimaro (Brosimum utile), Ceiba (Ceiba pentandra), Tamarindo (Dialum guianense), and Roble flor morado (Tabebuia rosea). Information given in the literature is complemented with results of bending experiments when information is lacking. The result emphasizes that tropical species are fitter than temperate species for bowed wood applications.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1161
Maderas-Cienc Tecnol; Vol. 16 No. 2 (2014); 245-264
Maderas-Cienc Tecnol; Vol. 16 Núm. 2 (2014); 245-264
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1161/1113
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1163
2017-09-20T17:29:24Z
MCT:art.
driver
Degradation of polypropylene in naturally and artificially weathered plastic matrix composites
S. Fabiyi, James
G. McDonald, Armando
crystallinity
molecular weight distribution
polypropylene
weathering
wood plastic composites
Effects of accelerated and natural weathering on the molecular weight distribution (MWD) and crystallinity of polypropylene (PP) in wood plastic composites (WPC) were investigated. The composites were produced from pine fibers (60%) and PP (40%). Prolonged weathering caused an increase in wood degradation and erosion thereby leaving cracks and ‘‘pits’’ on the surface. Pyrolysis gas chromatography-mass spectrometry (Py GC-MS) revealed that PP dominated the weathered surface due to wood degradation. For matrix analysis, PP was extracted using 1,2,4-trichlorobenzene. Crystallinity and molecular weight distribution of PP were monitored by differential scanning calorimetry (DSC) and gel permeation chromatography (GPC), respectively. PP’s crystallinity increased upon longer exposure time. The weight and number average molecular weight (Mw and Mn) decreased with an increase in weathering duration. An increased polydispersity (PD = Mw/Mn) implies that a secondary cross-linking process occurred during weathering.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1163
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 275-290
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 275-290
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1163/1115
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1164
2017-09-20T17:29:24Z
MCT:art.
driver
Some physical characteristics of thermally modified oriental-beech wood
Baysal, Ergun
Kart, Saban
Toker, Hilmi
Degirmentepe, Selim
heat treatment
oriental-beech
surface roughness
glossiness
color
mass loss
Heat treatment of Oriental-beech (Fagus orientalis) wood was carried out by hot air in an oven for 2, 4, and 8 h at 140, 170, and 200°C. After heat treatment, some physical characteristics such as surface roughness, color, glossiness, and mass loss of Oriental-beech wood specimens were measured.Our results showed that heat treatment caused decrease in surface roughness, glossiness, and mass loss values of Oriental-beech (Fagus orientalis) wood specimens. The decrease in lightness at all temperatures indicates that the specimens become darker with the treatment time. While, a* coordinate (red component) decreased as temperature increased, b* coordinate (yellow component) initially increased at 140°C and then decreased at 170°C and 200°C.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1164
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 291-298
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 291-298
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1164/1116
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1165
2017-09-20T17:29:24Z
MCT:art.
driver
Moisture absorption and dimensional stability of poplar wood impregnated with sucrose and sodium chloride
Petr, Pařil
Aleš, Dejmal
wood modification
sodium chloride
sucrose
vacuum-pressure impregnation
swelling
equilibrium moisture content
This paper deals with the effect of vacuum-pressure impregnation of Poplar wood (Populus alba) by aqueous solutions of sucrose and sodium chloride on its physical properties. Groups of samples with different concentrations of substances in the aqueous solution were compared within each other and also with a reference (non-impregnated) group. The specimens from all groups were tested for density, moisture absorption and dimensional stability. The obtained data were statistically analysed and compared each other. The most satisfying final properties were achieved in impregnation of sucrose with concentration of 6,25 g/100 ml H2O. The retention was 31 kg m-3 (WPG around 8 %). The values of ASE (anti-swelling efficiency) reached to 36 % and MEE (moisture exclusion efficiency) was reduced by 33 %.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1165
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 299-312
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 299-312
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1165/1117
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1166
2017-09-20T17:29:24Z
MCT:art.
driver
Chemical and biometrical properties of plum wood and its application in pulp and paper production
Kiaei, Majid
Tajik, Milad
Vaysi, Ramin
prunus domestica
stem
branch
biometrical properties
chemical properties
Plum (Prunus domestica) is one of the most widespread species of fruit trees in Asia and South-East Europe. There are large quantities of fruit wood trees without suitable usage in world. The aim of this research was to examine biometrical and chemical properties of the plum wood and its application in the pulp and paper industry. Five normal plum trees were randomly selected from Shahriyar province, Iran. A log cut down at stem (breast height) and branch for each of trees. The pith parts of cross-section were removed to examine the chemical (according to the TAPPI standard) and biometrical properties (according to the Franklin method). Results indicated that there were significant differences between stem and branch samples in fiber diameter and lumen diameter. Types of wood (branch and stem) had not significant differences on the chemical properties and fiber length, cell wall thickness and morphological properties. Among all of studied properties, the lignin, cellulose, fiber diameter, fiber lumen diameter, cell wall thickness and flexibility coefficient in branch wood is higher than stem wood. Although Runkel and flexibility coefficients of stem and branch fibers are lower than the accepted standard, but because of closing amount of lignin, extractive composition and fiber length to hardwood species, it can solve some of the problems of the lack of raw materials for paper production.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1166
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 313-322
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 313-322
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1166/1118
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1167
2017-09-20T17:29:24Z
MCT:art.
driver
A contribution to the identification of charcoal origin in brazil i – Anatomical characterization of corymbia and eucalyptus
Pereira Goncalves, Thais Alves
Wagner Ballarin, Adriano
Nisgoski, Silvana N
Bolzon de Muñiz, Graciela Inés
anatomy
charcoal
eucalyptus
sustainability
Charcoal is one of the main forestry products and Brazil is the world’s largest producer. Its production from native species is estimated at 30-35% of total output. One of the major problems of the iron and steel industry is charcoal consumption, especially in terms of environmental and social aspects. Therefore, the use of reforestation species must be increased. Considering most of the energy forests in Brazil are planted with eucalyptus, the present work aims to contribute to the identification of charcoal origin through anatomical analysis of Eucalyptus and Corymbia. The wood samples were carbonized in a muffle furnace during 7h to a maximum of 450ºC. Anatomical analysis was done according to IAWA Committee. We found few works with charcoal anatomy and the species analyzed were not characterized. The results on charcoal are very close to previous studies of wood anatomy. But, we recommend the comparison of materials of similar features, enhancing the visual acuity, particularities of each material and modifications that might happen. We believe that this analysis is an accurate tool to identify the source of charcoal and can help to guarantee the sustainability of the charcoal supply chain.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1167
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 323-336
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 323-336
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1167/1119
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1168
2017-09-20T17:29:24Z
MCT:art.
driver
Effect of drying process on marupá wood color
Gonçalez, Joaquim Carlos
Bezerra Marques, Márcia Helena
Sousa Karas, Maria Cristina
Janin, Gerard
Gomes Ribeiro, Patricia
simarouba amara
color
directions
drying methods
This research was developed after consultations with tropical timber exporters, who were facing problems with the colors of the species under study. This work aimed at characterizing Simarouba amara tropical wood color and verifying possible differences between the colorimetric parameters determined for the tangential and the radial directions of the wood, kiln-dried and air-dried. S. amara wood presents a grayish-white color. This color is mainly characterized by the b* coordinate (yellow pigment). Depending on the drying method used, the wood may present different colors for both tangential and radial directions. In both drying methods conducted, the wood presented lighter color in the tangential direction. Kiln-drying appeared to reduce S. amara wood lightness.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1168
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 337-342
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 337-342
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1168/1120
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1169
2017-09-20T17:29:24Z
MCT:art.
driver
Patrones de variación de la densidad de la madera y morfometría celular de Salix babylonica para la determinación de la edad de transición entre madera juvenil y madura
C. Cobas, Ana
C. Area, María
Monteoliva, Silvia
radial variations
segmented regression
fibre properties
vessels
juvenile wood
variación radial
regresiones segmentadas
morfometría de fibras
vasos
madera juvenil
El objetivo del trabajo fue analizar los patrones de variación axial y radial de la densidad y morfometría celular de la madera de sauce americano y determinar la edad de transición de madera juvenil a madura. Se muestrearon cinco árboles de 45 años de Salix babylonica de Entre Ríos, Argentina. Se tomaron muestras a tres alturas en el fuste y en 9 posiciones radiales y se determinó la densidad básica y la morfometría de fibras y vasos. Los patrones de variación radial evidenciaron un leve aumento de magnitud con la edad, mientras que la mayor variación axial se manifestó mayoritariamente entre la base y la altura de 1,3m el fuste, presentándose diferentes tendencias de acuerdo a la variable. Dependiendo de la variable analizada, la edad de transición entre madera juvenil y madura fue de 5 a 10 años o de 10 a 15 años. La longitud y ancho de fibras y el diámetro de vasos fueron los primeros parámetros en madurar. Los valores promedio de las variables de la madera juvenil y madura no mostraron diferencias importantes entre los leños, por lo tanto podrían considerarse como homogéneos desde el punto de vista anatómico y de densidad. AbstractThe aim of this work was to determine the patterns of axial and radial variation of the density and cellular morphometry of american willow wood, for determining the age of transition from juvenile to mature wood. The study was conducted on five trees of a 45-years-old plantation of a clone of Salix babylonica, from Entre Rios, Argentina. Samples were taken at three heights and at 9 radial positions of the stem for the determination of basic density and morphometry of fibers and vessels. The radial variation patterns showed a slight increase in magnitude with age, whereas the axial variation showed up between the base and a height of 1.3 m in the stem, presenting different tendencies according to the variable. Depending on the analyzed variable, the age of transition between juvenile and mature wood was 5 to 10 years, or 10 to 15 years. Fiber length and width and vessel diameter were the first characters to mature. The average values of the properties of juvenile and mature wood showed no substantial differences between logs, therefore they could be considered as anatomically and density homogeneous.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1169
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 343-354
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 343-354
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1169/1121
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1170
2017-09-20T17:29:24Z
MCT:art.
driver
Some surface properties of thermally modified scots pine after artificial weathering
Baysal, Ergun
Degirmentepe, Selim
Simsek, Hakan
scots pine
thermal modification
artificial weathering
surface roughness
glossiness
color
In this study, it was aimed to investigate some surface characteristics such as surface roughness, color, and glossiness of Scots pine (Pinus sylvestris) wood specimens after 500 hours artificial weathering exposure. The results showed that surface characteristics of thermally modified Scots pine gave better results than unmodified Scots pine after artificial weathering. Artificial weathering caused an increase in surface roughness and a decrease in glossiness of Scots pine wood. Results showed artificial weathered wood become darker, reddish, and yellowish. Generally, higher duration and temperature for Scots pine resulted in better surface characteristics of Scots pine after artificial weathering.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1170
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 355-364
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 355-364
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1170/1122
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1171
2017-09-20T17:29:24Z
MCT:art.
driver
Improving dimensional stability of injection molded wood plastic composites using cold and hot water extraction methods
Ozdemir, Ferhat
Ayrilmis, Nadir
Kaymakci, Alperen
Heon Kwon, Jin
cold water extraction
dimensional stability
hot water extraction
wood plastic composite
Dimensional stability of wood plastic composites (WPCs) made from polypropylene and pine wood flour with and without coupling agent was investigated. The pine wood flour was prepared from wood chips which had been immersed, respectively, in boiling water for 1 h, 3 h, and 5 h or in distilled water for 1 day, 3 days, and 5 days at room temperature. It was found that thickness swelling (TS) and water absorption (WA) of the WPCs made using extracted wood were lower than those of WPCs produced with unextracted wood. The TS and WA values of WPCs decreased with extraction duration both for cold and hot water extraction. The effect of hot water extraction on the TS and WA properties of the WPCs was more pronounced than cold water extraction.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1171
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 365-372
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 365-372
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1171/1123
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1172
2017-09-20T17:29:24Z
MCT:art.
driver
Tensiones de crecimiento y propiedades físicas de la madera de Eucalyptus dunnii implantado en Argentina
Hernández, Mariano
Zaderenko, Constantino
Monteoliva, Silvia
basic density
volumetric shrinkage
GSI
split index
pith-to-bark gradient
densidad básica
contracción volumétrica
índice de rajado
gradiente densidad
El objetivo del trabajo fue evaluar tensiones de crecimiento en Eucalyptus dunnii y determinar el efecto de las propiedades físicas de la madera sobre esta variable. Se muestrearon 45 árboles de un ensayo de 19 años situado en la provincia de Corrientes, Argentina. Se realizaron determinaciones de tensiones de crecimiento a través de dos métodos: indicador de tensiones de crecimiento (GSI, CIRAD-Forêt) e índice de rajado en rollizo (IR). Se midieron las propiedades físicas, densidad básica y contracción volumétrica total y se determinó la variación radial de la densidad básica. Los resultados de GSI e IR mostraron valores más bajos que los citados para la especie (GSI: 0,0763 0,0251 mm e IR: 0,43 0,31 %) y tuvieron buena asociación entre sí (r: 0,71). Se encontró una asociación baja entre tensiones de crecimiento con las propiedades físicas de la madera, densidad básica (r: 0,35 - 0,39) y contracción volumétrica total (r: 0,29 -0,35). Los niveles de asociación aumentaron cuando las correlaciones se hicieron entre las estimaciones de tensiones de crecimiento y la tasa de cambio radial de la densidad básica (r: 0,59 - 0,52). AbstractTo evaluate growth stresses in Eucalyptus dunnii and determine the effect of physical wood properties on that variable, a total of 45 trees were sampled from a 19-years-old trial located at Corrientes, Argentina. Growth stresses were determined using the growth stress indicator (GSI, CIRAD-Forêt) and the log end split index (IR). The physical wood properties basic density and total volumetric shrinkage were measured and the pith-to-bark gradient of the basic density was determined. GSI and IR values obtained were lower than those cited for the species (GSI: 0,0763 0,0251 mm and IR: 0,43 0,31 %) and showed good association between themselves (r: 0,71). A low association between growth stresses and the physical wood properties basic density (r: 0,35 – 0,39) and volumetric shrinkage total (r: 0,29-0,35) was founded. The association levels were higher when growth stresses (GSI and IR) and the pith-to-bark gradient of the basic density (r: 0,59-0,52) were correlated.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1172
Maderas-Cienc Tecnol; Vol. 16 No. 3 (2014); 373-384
Maderas-Cienc Tecnol; Vol. 16 Núm. 3 (2014); 373-384
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1172/1124
Derechos de autor 2015 Maderas. Ciencia y Tecnologia
oai:ojs.revistas.ubiobio.cl:article/1175
2017-09-20T17:29:02Z
MCT:art.
driver
Effect of ultrasound pretreatment on wood prior to vacuum drying
He, Zhengbin
Zhao, Zijian
Yang, Fei
Yi, Songlin
drying time
effective water diffusivity
ultrasound
wood vacuum drying
The influence of ultrasonic pretreatment prior to vacuum drying of Chinese fir specimens was examined in this work. In the pretreatments, wood samples were immerged in a distilled water bath and were treated using two wave frequencies for four different elapsed times to investigate effects of ultrasonic frequency and treatment duration. Then the wood samples were vacuum-dried at 80°C and absolute pressure of 0,05 MPa. After the pretreatment, microscopic analysis was carried out on the wood samples to check micro-cracks, the loss of extractives from the cell walls and other micro-structural changes on the wood. Results show that the ultrasonic treatment prior to vacuum drying significantly shortened the wood drying time. The drying time decreased with increase in the wave frequency and the treatment time. Furthermore, ultrasound pretreatment tended to reduce the content of extractives in the wood cell walls and cause cell-wall micro-cracking.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1175
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 395-402
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 395-402
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1175/1126
Derechos de autor 2015 Zhengbin He, Zijian Zhao, Fei Yang, Songlin Yi
oai:ojs.revistas.ubiobio.cl:article/1176
2017-09-20T17:29:02Z
MCT:art.
driver
The effect of thermal treatment on physical and mechanical properties of luehea divaricata hardwood
Schneid, Eduardo
Gonzalez de Cademartori, Pedro Henrique
Gatto, Darci
brittleness
dimesional stability
modulus of elasticyty
modulus of rupture
roughness
This study aimed to characterise the effect of thermal treatment on physical and mechanical properties of açoita-cavalo (Luehea divaricata) wood. To achieve this, samples were treated at 160, 180 and 200°C for 2 h in an oven (dry conditions). Physical and mechanical characterisation was performed by weight loss, dry specific gravity at 12%, equilibrium moisture content, volumetric swelling and shrinkage, water absorption, water repellence, static bending and brittleness tests. Roughness and colour tests were performed in order to evaluate the modified surface. Main findings showed that dimensional stability of thermally modified wood increased, while mechanical strength of wood decreased as a function of temperature. A darkening of wood and a decrease in roughness were observed.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1176
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 413-422
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 413-422
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1176/1127
Derechos de autor 2015 Eduardo Schneid, Pedro Henrique Gonzalez de Cademartori, Darci Gatto
oai:ojs.revistas.ubiobio.cl:article/1177
2017-09-20T17:29:02Z
MCT:art.
driver
Efecto de las tensiones de crecimiento en el rendimiento y calidad del aserrado de Eucalyptus dunnii
Hernández, Mariano
Zaderenko, Constantino
Monteoliva, Silvia
eucalyptus dunnii
growth stresses
sawnwood
split index
aserrado
índice de rajado
tensiones de crecimiento
Se evaluó el efecto de las tensiones de crecimiento sobre la calidad y rendimiento de tablas de Eucalyptus dunnii aserradas verdes. Se muestrearon 45 árboles de un ensayo de 19 años situado en la Provincia de Corrientes, Argentina. Se aserró un rollizo (2 m de largo) por árbol para obtener tablas tangenciales de 2,54 cm de espesor. Se utilizaron los valores de tensiones de crecimiento GSI (CIRAD-Forêt) e índice de rajado en rollizo (IR) determinados sobre esos árboles en un trabajo previo. Se midió el largo de las tablas y de las rajaduras de cabeza. Se determinó el porcentaje de piezas con rajadura de cabeza (P), un índice que cuantifica las rajaduras para la totalidad de tablas aserradas (IRTC) y un índice que cuantifica las rajaduras para las tablas aserradas por rollizo (IRT). Se calculó el rendimiento en bruto del aserrado (R) y un rendimiento en calidad que excluye el defecto de las rajaduras de cabeza (RC). El IRTC fue de 54,4 mm/m y el IRT de 27,87 mm/m ±19,85. Más de la mitad de tablas aserradas presentó rajaduras de cabeza (P: 58%), sin embargo el descenso del rendimiento del aserrado no fue pronunciado (R: 44,2% y RC: 41,7%). El IRT presentó una asociación moderada con las tensiones de crecimiento GSI e IR (r: 0,46 - 0,52). AbstractThe growth stress effects on yield and quality of Eucalyptus dunnii green sawn boards were evaluated. A total of 45 trees were sampled from a 19-years-old trial located at Corrientes, Argentina. Each tree was felled and cross-cut to produce a 2 m log. Subsequently each log was sawn to obtain tangential boards 2,54 cm thick. Growth stress indicator (GSI, CIRAD-Forêt) and log end split index (IR) values taken from these trees in a previous research were used. Length of boards and end checks were measured and the percentage of boards with end check (P) was determined. An index to quantify end checks for the whole sawn boards (IRTC) and another for the sawn boards per log (IRT) were calculated. Sawlog gross yield (R) and a quality sawlog yield (RC) which exclude the end check defects were calculated. The IRTC was 54,4 mm/m and the IRT was 27,87 mm/m ±19,85. More than half of the boards had end checks (P); nevertheless the sawlog yield did not show a high decline (R: 44,2 % and RC: 41,7 %). The association between IRT and growth stress indicator GSI and log end split index IR was moderate (r: 0,46 – 0,52).
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1177
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 403-412
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 403-412
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1177/1128
Derechos de autor 2015 Mariano Hernández, Constantino Zaderenko, Silvia Monteoliva
oai:ojs.revistas.ubiobio.cl:article/1178
2017-09-20T17:29:02Z
MCT:art.
driver
Effect of precipitation pattern on leaching of preservative from treated wood and implications for accelerated testing
Lebow, Stan
wood preservative
leaching
accelerated testing
precipitation
rainfall intensity
There is a need to develop improved accelerated test methods for evaluating the leaching of wood preservatives from treated wood exposed to precipitation. In this study the effects of rate of rainfall and length of intervals between rainfall events on leaching was evaluated by exposing specimens to varying patterns of simulated rainfall under controlled laboratory conditions. Lumber specimens were pressure-treated with 0,5; 1 or 2,% solutions of chromated copper arsenate (CCA) and exposed to 762 mm of rainfall at rates of 2,5; 8 or 25 mm/h. Intervals between rainfall events were increased for some specimens. Leachate was periodically collected and analyzed to quantify leaching of arsenic, chromium and copper. The quantity of CCA elements leached, per unit rainfall, was consistently greatest at the lowest rainfall rate for all solution concentrations evaluated. Incorporation of additional time between rain events increased leaching at the lowest rainfall rate, but this effect was less noticeable as rainfall rate increased. The results of this study indicate that simulated rainfall leaching tests should be conducted using rainfall intensities at the lower end of those that are typical for the region of interest. The lengths of intervals between rainfall events may also increase leaching, but use of lengthy resting intervals conflicts with the goal of accelerated testing. Further research may be warranted to optimize time between rainfall events and assess the effect of drying periods between rainfall events.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1178
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 423-434
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 423-434
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1178/1129
Derechos de autor 2015 Stan Lebow
oai:ojs.revistas.ubiobio.cl:article/1179
2017-09-20T17:29:02Z
MCT:art.
driver
Predicting the young’s modulus of defect free radiata pine shooks in finger-jointing using resonance frequency
S.S, How
Williamson, C.J
Carradine, D.
Tan, Y.E
Cambridge, J.
Pang, S.
dynamic MOE
static MOE
finger-jointing
radiata pine
non-destructive tool
modelling
shooks
In this paper, dynamic MOE and static MOE of short-length radiata pine specimens produced for finger jointing were measured using non-destructive technique and correlated to each other. In order to obtain reliable static MOE data, 36 mm thickness shooks as well as the matched samples of reduced thickness (15mm) were tested, and the effect of annual growth rings on dynamic and static MOE is also addressed. Mathematical correlations were fitted between the dynamic MOE for the 36 mm thick shooks and the static MOE of the 15 mm thick samples. The coefficient of determination for dynamic MOE group 4,00-7,99 GPa was the strongest (R2 = 0,82) and the correlation strength was further improved for sorted quarter sawn samples (R2 = 0,92). Finally, the correlation between static modulus of rupture (MOR) and dynamic MOE is discussed.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1179
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 435-444
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 435-444
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1179/1130
Derechos de autor 2015 How S.S, C.J Williamson, D. Carradine, Y.E Tan, J. Cambridge, S. Pang
oai:ojs.revistas.ubiobio.cl:article/1180
2017-09-20T17:29:02Z
MCT:art.
driver
Effects of veneer drying at high temperature and chemical treatments on equilibrium moisture content of plywood
Aydin, Ismail
equilibrium moisture content
high temperature drying
impregnation
plywood
Moisture content (MC) is one of the most important factors that can affect many physical and mechanical properties of wood and veneers. MC strongly affects the final strength and durability of joints, development of surface checks in the wood and dimensional stability of the bonded assembly. In this study, plywood panels made from Alnus glutinosa (Alder), Fagus orientalis (Beech) and Picea orientalis (Spruce) wood veneers were treated with ammonium acetate, borax and boric acid by using dipping method to test for their equilibrium moisture content (EMC). Borax and boric acid solutions were used for fire-retardancy, and ammonium acetate for reducing formaldehyde emission. Two different veneer drying temperatures (20°C and 180°C) were used to reveal the effects of veneer drying at high temperature on the hygroscopicity of plywood panels. EMC values of alder, beech and spruce panels decreased significantly with veneer drying at high temperature. Picea orientalis (Spruce) plywood panels had the highest EMC values and followed by Alnus glutinosa (Alder) and Fagus orientalis (Beech) panels. EMC values of plywood panels increased significantly for both drying temperatures after ammonium acetate, borax and boric acid treatments.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1180
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 445-452
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 445-452
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1180/1131
Derechos de autor 2015 Ismail Aydin
oai:ojs.revistas.ubiobio.cl:article/1181
2017-09-20T17:29:02Z
MCT:art.
driver
Color stability of weathered heat-treated teak wood
Aparecida Garcia, Rosilei
de Oliveira Lopes, Juliana
do Nascimento, Alexandre Miguel
de Figueiredo Latorraca, João Vicente
CIE-Lab system
heat treatment
ultraviolet radiation
This study investigated the color stability in a heat treatment of teak wood (Tectona grandis) exposed to ultraviolet radiation under accelerated aging conditions. Nine trees from three different spacing levels were used. Samples of 150 mm x 75 mm x 20 mm were prepared and divided into two groups: heartwood and sapwood. Two levels of heat treatment (180 and 200°C) were used. The color was measured every 42 hours with a portable spectrophotometer using the CIE-Lab system. Accelerated aging was performed in a QUV/Spray chamber. The total cycle of exposure to ultraviolet radiation was of 168 hours at 340 nm. Tree planting spacing had no effect on color change after ultraviolet radiation. Untreated sapwood had greater color change than untreated heartwood. However, after heat treatment, sapwood showed high color stability, especially at a temperature of 180°C.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1181
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 453-462
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 453-462
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1181/1132
Derechos de autor 2015 Rosilei Aparecida Garcia, Juliana de Oliveira Lopes, Alexandre Miguel do Nascimento, João Vicente de Figueiredo Latorraca
oai:ojs.revistas.ubiobio.cl:article/1182
2017-09-20T17:29:02Z
MCT:art.
driver
Valoración mecanotérmica de una resina biodegradable como agente de acoplamiento de materiales compuestos celulósicos/polímero hidrofóbico
Pulido González, H.
Hernandez, E.
Rabelero Velasco, M.
Sanjuan Raygoza, RJ.
Jasso Gastinel, C.F.
coupling agent
wood plastic composite
rosin
maleated rosin
mechanical properties
agente de acoplamiento
materiales compuestos
brea
colofonia
brea maleinizada
propiedades mecánicas
En la búsqueda de plásticos reforzados con fibras que sean más amigables con el medio ambiente, aquí se presenta el primer estudio que evalúa la posibilidad de utilizar la brea natural de pino (en forma pura o maleinizada) como agente de acoplamiento (biodegradable). Polipropileno (matriz) y fibra de agave (Agave tequilana) de desecho a diferentes concentraciones (agente de refuerzo), fueron acoplados con cada uno de los agentes utilizados; su efecto en las propiedades mecánicas se comparó con el de un agente comercial de polipropileno modificado (Epolene E-43). Igualmente se prepararon, materiales compuestos sin agente de acoplamiento como referencia genérica. El desempeño mecanodinámico y mecanoestático de los materiales muestra claramente el incremento de propiedades mecánicas con los 3 agentes utilizados. La brea maleinizada mostró similitud o ligera superioridad sobre el agente comercial en el efecto logrado. La afectación en cristalinidad por la presencia de la fibra y el agente de acoplamiento correspondiente, fue evaluada mediante calorimetría diferencial de barrido. La absorción de agua como función del tiempo, permitió medir de forma indirecta el cambio logrado en la superficie de los materiales, y un análisis de FTIR, la valoración de la interacción fibra-polímero obtenida con el agente de acoplamiento. Tal interacción lograda con los agentes de acoplamiento, pudo ser además apreciada utilizando microscopía electrónica de barrido. Los resultados alcanzados marcan el camino para poder usar resinas naturales biodegradables como agentes de acoplamiento en el área de plásticos reforzados con fibras celulósicas. AbstractIn the search of useful environmentally friendly fiber reinforced plastics, this is the first study that evaluates the capability to use natural pine rosin (in pure or maleated glycerol ester form) as a biodegradable coupling agent. Polypropylene as polymer matrix and discarded agave fiber (Agave tequilana) as reinforcing agent at different concentrations, were coupled with each one of the two rosins above mentioned; a commercial maleated polypropylene (Epolene, E-43) agent was used to compare their effect. As generic reference, composites without coupling agent were also tested. Mechanodynamic and mechanostatic tests clearly show an increment in mechanical properties of the composites, using any of the 3 coupling agents. The results obtained with maleated rosin were similar or slightly better than the ones obtained with the commercial agent for composites with high fiber content. Fiber content and coupling agent effect on composites crystallinity, was evaluated by differential scanning calorimetry. In addition, water absorption as a function of time was followed to evaluate the effect of surface modification, and FTIR analysis allowed the observation of the fiber-polymer matrix interaction that was promoted with the coupling agents. The effect of such interaction obtained with the different coupling agents, was observed by scanning electron microscopy. The results show the feasibility to use the natural pine rosin in pure or modified form as biodegradable coupling agents.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1182
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 463-486
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 463-486
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1182/1133
Derechos de autor 2015 H. Pulido González, E. Hernandez, M. Rabelero Velasco, RJ. Sanjuan Raygoza, C.F. Jasso Gastinel
oai:ojs.revistas.ubiobio.cl:article/1183
2017-09-20T17:29:02Z
MCT:art.
driver
Microfibril angle of Eucalyptus grandis wood in relation to the cambial age
Tarcísio Lima, José
de Oliveira Ribeiro, Alessandra
Rezende Pinto Narciso, Carolina
cambial age
eucalyptus grandis
microfibril angle
The microfibril angle (MFA) of wood is an important feature, which helps to explain the physical and mechanical behaviour of wood in use. It has been little investigated for wood produced in Brazil, mainly for mature trees. Thus, the objective of this study was to analyze the MFA of Eucalyptus grandis at age 25 years in relation to the cambial age. One disk was cut from the base of the stem from each of three trees, where growth rings were marked. From a central strip 3,0 cm wide, 1 cm3 blocks were removed from each growth ring. After sectioned on the tangential face with a sliding microtome, sections of 8 μm thick were macerated. The individual fibres were observed by polarized light microscopy for measurement of MFA. According to the results, i) the MFA decreased from 29,3° (ring nº 1) to 18,9° (ring nº 25); ii) MFA can be estimated by the cambial age – a, according to the equation MFA = 28,1 – 0,35 × a, with R2 = 94,7%.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1183
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 487-494
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 487-494
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1183/1134
Derechos de autor 2015 José Tarcísio Lima, Alessandra de Oliveira Ribeiro, Carolina Rezende Pinto Narciso
oai:ojs.revistas.ubiobio.cl:article/1184
2017-09-20T17:29:02Z
MCT:art.
driver
Influence of residual lignin content on physical and mechanical properties of kraft pulp/pp composites
Kiaei, Majid
Kord, Behzad
Vaysi, Ramin
alkalinity
cooking time
residual lignin content
mechanical properties
water absorption
The effect of residual lignin content on the mechanical strength and water absorption of kraft pulp/polypropylene composites was studied. To meet this objective, hornbeam wood chips were converted to kraft pulp at three different alkalinities (15, 20, and 25%) and three different cooking times (60, 90, and 120 min). The residual lignin contents of these pulps were determined according to the TAPPI standard. Kraft pulp was mixed with polypropylene (PP) at 50% weight ratios. The amount of maleic anhydride (MAPP) coupling agent was fixed at 4 per hundred compounds (phc) for all formulations. The results indicated that the lignin residual content decreased with increasing cooking time and alkalinity in kraft pulp. Also, it was found that tensile strength, tensile modulus, flexural strength, and flexural modulus were increased by increasing the alkalinity and cooking time; however, the notched impact strength and water absorption decreased. Overall, decreasing the lignin content had a positive impact on the flexural and tensile properties and had a negative effect on the notched impact strength.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1184
Maderas-Cienc Tecnol; Vol. 16 No. 4 (2014); 495-503
Maderas-Cienc Tecnol; Vol. 16 Núm. 4 (2014); 495-503
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1184/1135
Derechos de autor 2015 Majid Kiaei, Behzad Kord, Ramin Vaysi
oai:ojs.revistas.ubiobio.cl:article/1198
2017-09-20T17:27:24Z
MCT:art.
driver
Phytosanitation of mountain pine beetle infected lodgepole pine using dielectric fields at radio frequencies
Lazarescu, Ciprian
Breuil, Colette
Avramidis, Stavros
dendroctonus ponderosae
dielectric heating
pasteurization
pinus contorta
radio frequency
As an environmentally friendly alternative to chemical treatment, this research aimed to establish whether dielectric heating at high frequency of infested lodgepole pine (Pinus contorta) boards and logs, obtained from the mountain pine beetle devastated forests of British Columbia, can result in wood free of living fungi, nematodes and insects. The sample set contained 230 boards, 50x150 and 50x100 mm2 in cross-section and 20 logs, 200-300 mm in diameter; all tested specimens were roughly one meter long. The intention was to test the efficiency of two temperature/time combinations: 56ºC for 30min and 60ºC for 15min that were identified in past works as effective phytosanitary combinations. Data showed that both permutations eradicated all infestation levels and types. The electric field power density per treatment cycle ranged from 23 to 50 kW/m3 and the total heating cycle varied from 42 to 116 minutes for all pest and wood type combinations tested.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1198
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 221-228
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 221-228
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1198/1149
Derechos de autor 2015 Ciprian Lazarescu, Colette Breuil, Stavros Avramidis
oai:ojs.revistas.ubiobio.cl:article/1199
2017-09-20T17:27:24Z
MCT:art.
driver
Influence of specimen orientation on determination of elesticity in static bending
Hideyoshi Icimoto, Felipe
Salles Ferro, Fabiane
de Almeida, Diego Henrique
Cristoforo, André Luís
Rocco Lahr, Francisco Antonio
modulus of elasticity
static bending test
stiffness
Wood is a natural material and so many factors interfere in estimation of its physical and mechanical properties. Consequently variability in properties should be taken into account to rationalize its application. Longitudinal modulus of elasticity is one of the main mechanical properties of the material, and its value can be obtained via standardized tests. The aim of this study is to evaluate the influence of test conditions compatible with ABNT NBR 7190:1997 Code requirements to determine modulus of elasticity in static bending. For each of eight species, eight specimens were tested, all of them four times, with the sample oriented on each of its four faces related to load application. Data analysis was performed independently of species and their respective strength class, using hypothesis testing to evaluate influence of specimens’ orientations to determination. It was concluded that specimen orientation is significant in determining modulus of elasticity in static bending according to ABNT NBR 7190:1997. This aspect can lead to a future normative review by the National Committee responsible by redaction of this Code. To represent natural variability of wood in specimens’ volume by only one bending test, values of the modulus of elasticity should be lessened in 8%.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1199
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 229-238
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 229-238
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1199/1150
Derechos de autor 2015 Felipe Hideyoshi Icimoto, Fabiane Salles Ferro, Diego Henrique de Almeida, André Luís Cristoforo, Francisco Antonio Rocco Lahr
oai:ojs.revistas.ubiobio.cl:article/1200
2017-09-20T17:27:24Z
MCT:art.
driver
Prediction of mechanical properties - Modulus of rupture and modulus of elasticity - of five tropical species by nondestructive methods
Baar, Jan
Tippner, Jan
Rademacher, Peter
density
dynamic modulus of elasticity
interlocked grain
modulus of rupture
nondestructive methods
tropical wood
This paper analyzes the usability of different dynamic moduli of elasticity and wood density for the prediction of mechanical properties – static modulus of elasticity and modulus of rupture – in samples with grain deflection from the longitudinal direction. Five tropical hardwoods (Afzelia bipindensis, Intsia bijuga, Millettia laurentii, Astronium graveolens and Microberlinia brazzavillensis) with different grain characteristics were used for this purpose. The fiber deflection was caused by the presence of interlocked grain or the working process. The three nondestructive techniques used in this study – longitudinal and flexural resonance method and ultrasound method – provided higher values of modulus of elasticity than the static bending test, but close correlation was observed between these variables. The weakest correlation was found for the ultrasound method which is probably caused by its measuring mechanism. The prediction of the modulus of rupture is less accurate when the dynamic modulus of elasticity is compared with the static modulus of elasticity; on the other hand, it was still good in comparison with the density model, which is inapplicable when grain deflection occurs in wood. In the wood of Zebrano where the interlocked grain was strongly developed, almost all of the correlation coefficients showed the lowest values and the prediction of modulus of rupture by nondestructive techniques was unsatisfactory.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1200
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 239-252
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 239-252
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1200/1151
Derechos de autor 2015 Jan Baar, Jan Tippner, Peter Rademacher
oai:ojs.revistas.ubiobio.cl:article/1201
2017-09-20T17:27:24Z
MCT:art.
driver
Utilization of temperature kinetics as a method to predict treatment intensity and corresponding treated wood quality: Durability and mechanical properties of thermally modified wood
Candelier, K.
Hannouz, S.
Elaieb, M.
Collet, R.
Dumarçay, S.
Pétrissans, A.
Gérardin, P.
Pétrissans, M.
control quality
decay resistance
heat treatment
mass loses
mechanical properties
temperature kinetics
Wood heat treatment is an attractive alternative to improve decay resistance of wood species with low natural durability. However, this improvement of durability is realized at the expense of the mechanical resistance. Decay resistance and mechanical properties are strongly correlated to thermal degradation of wood cells wall components. Mass loss resulting from this degradation is a good indicator of treatment intensity and final treated wood properties. However, the introduction of a fast and accurate system for measuring this mass loss on an industrial scale is very difficult. Nowadays, many studies are conducted on the determination of control parameters which could be correlated with the treatment conditions and final heat treated wood quality such as decay resistance. The aim of this study is to investigate the relations between kinetics of temperature used during thermal treatment process representing heat treatment intensity, mass losses due to thermal degradation and conferred properties to heat treated wood. It might appear that relative area of treatment temperature curves is a good indicator of treatment intensity. Heat treatment with different treatment conditions (temperature-time) have been performed under vacuum, on four wood species (one hardwood and three softwoods) in order to obtain thermal degradation mass loses of 8, 10 and 12%. For each experiment, relative areas corresponding to temperature kinetics, mass loss, decay resistance and mechanical properties have been determined. Results highlight the statement that the temperature curves’ area constitutes a good indicator in the prediction of needed treatment intensity, to obtain required wood durability and mechanical properties such as bending resistance and Brinell hardness.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1201
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 253-262
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 253-262
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1201/1152
Derechos de autor 2015 K. Candelier, S. Hannouz, M. Elaieb, R. Collet, S. Dumarçay, A. Pétrissans, P. Gérardin, M. Pétrissans
oai:ojs.revistas.ubiobio.cl:article/1202
2017-09-20T17:27:24Z
MCT:art.
driver
Analytical and experimental studies on stress capacity with modified wood members under combined stresses
Abdolzadeh, H.
Ebrahimi, Gh.
Layeghi, M.
Ghassemieh, M.
corner joint
dowel
epoxy adhesive
furfurylation
stress capacity
The stress capacity of joints made of modified wood members under loading can be affected by design of joints and type of adhesive. Hence, these factors were addressed in this study by assessment of stress capacity variations in corner joints under diagonal applied compressive load induced combined stresses. The joints with mitered and butted design were constructed by application of epoxy and polyvinyl acetate (PVAc) adhesives from furfurylated wood samples with two weight percentage gains (WPGs), i.e., 20% as low level and 60% as high level. Results indicated that stress capacity in both corner joints was not significantly decreased with increasing polymerization of furfuryl alcohol (FA) in wood. Despite the high compression strength in mitered joint, the induced compression stresses were low in comparison with butted joint. The stress capacity in mitered joint bonded with epoxy adhesive enhanced with increasing the level of furfurylation. This was true for shear stress parallel to grain as well. Generally, it could be concluded that mitered joint made of furfurylated members and bonded with epoxy adhesive would be stronger than other corner joints.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1202
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 263-276
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 263-276
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1202/1153
Derechos de autor 2015 H. Abdolzadeh, Gh. Ebrahimi, M. Layeghi, M. Ghassemieh
oai:ojs.revistas.ubiobio.cl:article/1203
2017-09-20T17:27:24Z
MCT:art.
driver
Liquefied wood as a partial substitute of melamine-urea-formaldehyde and urea-formaldehyde resins
Esteves, Bruno
Martins, João
Martins, Jorge
Cruz-Lopes, Luísa
Vicente, José
Domingos, Idalina
automated bonding evaluation system
liquefied wood
particleboard
pinus pinaster
resin
Maritime pine (Pinus pinaster) sawdust was used to produce liquefied wood by the polyhydric method with acid catalysis. The process was optimized to produce the highest amount of liquefied wood. Wood liquefied at 160ºC for 90 min was used in the adhesion tests. The bond strength of veneer glued with urea-formaldehyde and melamine-urea-formaldehyde resins and several mixtures of liquefied wood with urea-formaldehyde and melamine-urea-formaldehyde wasevaluated by automated bonding evaluation system.With the increase in liquefied wood content the bond strength decreased. Nevertheless for 20% liquefied wood the reduction of internal bond strength is relatively small and still within the minimum standards required. When 70% of liquefied wood is employed there is a significant decrease in bond strength.In conclusion it is possible to use a small amount of maritime pine sawdust liquefied wood as a partial substitute of urea-formaldehyde and melamine-urea-formaldehyde resins in the particleboard production, thus decreasing the formaldehyde content.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1203
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 277-284
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 277-284
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1203/1154
Derechos de autor 2015 Bruno Esteves, João Martins, Jorge Martins, Luísa Cruz-Lopes, José Vicente, Idalina Domingos
oai:ojs.revistas.ubiobio.cl:article/1204
2017-09-20T17:27:24Z
MCT:art.
driver
Evaluation of wood surface roughness depending on species characteristics
Thoma, Hektor
Peri, Leonidha
Lato, Entela
cutting regime
roughness parameter
roughness profile
surface roughness
wood density
This study is focused on the impacts of species characteristics on the surface roughness of five species with different wood density namely white fir, Aleppo pine, European beech, walnut and white oak.The sample specimens tested were 300x300x30 mm in size and their surface quality was evaluated by the “the direct contact method” based on a mechanical system of measurement, giving the possibility of reproducing the surface measured and analyzing its profile.The surface roughness measurements were performed with a contact stylus profilometer, holding the moisture content of the specimens constant at 10%. The evaluation of the surface characteristics of the wood samples considered the roughness parameters: arithmetic mean deviation of the profile, maximum two point height of the profile, mean roughness depth and root-mean-square deviation of the profile.From the study result showed different average values of surface roughness parameters for broadleaved and conifers species. The differences can be explain by the influence on the roughness of the wood surface of the wood texture and the texture uniformity.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1204
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 285-292
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 285-292
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1204/1155
Derechos de autor 2015 Hektor Thoma, Leonidha Peri, Entela Lato
oai:ojs.revistas.ubiobio.cl:article/1205
2017-09-20T17:27:24Z
MCT:art.
driver
Aplicación de celulosa nanofibrilada, en masa y superficie, a la pulpa mecánica de muela de piedra: Una sólida alternativa al tratamiento clásico de refinado
Delgado-Aguilar, Marc
Recas, Elena
Puig, Josep
Arbat, Gerard
Pereira, Miguel
Vilaseca, Fabiola
Mutjé, Pere
nanofibers
mechanical pulp
cellulosic fibers
beating
surface treatment
nanofibras
pulpa mecánica de muela de piedra
fibras celulósicas
refino
tratamiento superficial
Se ha estudiado el efecto de distintos dosajes en masa de nanofibras de celulosa (CNF ), comprendidas entre un 0 y un 6%, sobre las propiedades físico-mecánicas del papel obtenido a partir de las fibras de pasta mecánica de muela de piedra (SGW). Los resultados obtenidos se han comparado con el procedimiento convencional de refinado a distintos grados (de 0 a 2500 RPM). Posteriormente se ha estudiado la incidencia que tiene la aplicación superficial de las CNF en superficie, sobre el papel sin CNF en masa y con CNF en masa. Los resultados obtenidos mostraron que la rigidez del papel y su longitud de ruptura aumentaron con el grado de refino, sin embargo el grado Schopper – Riegler (ºSR) aumentó de forma importante dificultando el drenaje. La aportación de CNF en masa también aumentó el ºSR y la longitud de ruptura, de esta manera el ºSR de un refino a 1500 rev fue equivalente a un contenido en CNF de entre el 4,5 y 6%, pero su longitud de ruptura resultó ser sensiblemente superior. Puede concluirse que la aplicación de CNF en masa puede contemplarse como una alternativa al refino mecánico y que la aplicación superficial de CNF permite dotar al papel de mejores propiedades sin afectar a la capacidad de drenaje. AbstractThe effect of different application amounts of nanofibrilated cellulose (CNF), from 0 to 6%, on the physico-mechanical properties of the paper obtained from stone ground wood pulp fiber has been studied. The results have been compared with the conventional beating process at different degrees (from 0 to 2500 rpm). Afterwards the effect of the application of CNF on the surface, in papers with and without CNF in bulk, has been studied. The results showed that the paper stiffness and breaking length increased with freeness; however the Schopper–Riegler grade (oSR) increased significantly hindering drainage. The contribution of CNF in bulk also increased °SR and breaking length, therefore the °SR beaten at 1500 rev was equivalent to a content of CNF between 4,5 and 6%, but its breaking length was found to be substantially greater. It can be concluded that the CNF in bulk can be viewed as an alternative to mechanical beating and that the application of CNF at the paper surface allows increasing strength properties without affecting the drainage capacity.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1205
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 293-304
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 293-304
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1205/1156
Derechos de autor 2015 Marc Delgado-Aguilar, Elena Recas, Josep Puig, Gerard Arbat, Miguel Pereira, Fabiola Vilaseca, Pere Mutjé
oai:ojs.revistas.ubiobio.cl:article/1206
2017-09-20T17:27:24Z
MCT:art.
driver
Characterization of the rhizophora particleboard as a tissue-equivalent phantom material bonded with bio–based adhesive
Taghizadeh Tousi, Ehsan
Hashim, Rokiah
Bauk, Sabar
Suhaimi Jaafar, Mohamad
Mohammad Hamdan Abuarra, Ali
Mahmoud Al-Jarrah, Amer
Ababneh, Baker
Taghizadeh Tousi, Afsaneh
Saleh Ali Aldroobi, Khalid
bio–adhesive
effective atomic number
particleboard
rhizophora sp.
serishoo
In this study, some characteristics of Rhizophora spp. particleboards bonded with Serishoom (traditional animal–based adhesive) as a phantom material was investigated. The Rhizophora spp. particleboards were fabricated in two Serishoom adhesive treatment levels (6% and 12%) with three Rhizophora spp. particle sizes (≤ 149 µm, 149 µm – 500 µm, and 500 µm – 1000 µm) at 1 g.cm-3 of the target density. The internal bond strength and the dimensional stability of the Serishoom-bonded Rhizophora spp. particleboards were improved by using the smaller Rhizophora spp. particle size and the higher Serishoom adhesive treatment level. The effective atomic numbers of the Serishoom-bonded Rhizophora spp. particleboards were determineted to be 7,56 to 7,58 by an energy dispersive X-ray, which is in good agreement with those of water and breast tissue. In addition, the density distribution profiles of the fabricated Serishoom-bonded Rhizophora spp. particleboards were determined by the Kriging method with the use Surfer8 computer software, which indicated that there was good density homogeneity throughout the Serishoom-bonded Rhizophora spp. particleboards. The results showed a potential of the Serishoom-bonded Rhizophora spp. particleboard bonded with Serishoom to be used as a phantom material.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1206
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 305-318
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 305-318
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1206/1157
Derechos de autor 2015 Ehsan Taghizadeh Tousi, Rokiah Hashim, Sabar Bauk, Mohamad Suhaimi Jaafar, Ali Mohammad Hamdan Abuarra, Amer Mahmoud Al-Jarrah, Baker Ababneh, Afsaneh Taghizadeh Tousi, Khalid Saleh Ali Aldroobi
oai:ojs.revistas.ubiobio.cl:article/1207
2017-09-20T17:27:24Z
MCT:art.
driver
Physical and mechanical properties of nanoreinforced particleboard composites
Candan, Zeki
Akbulut, Turgay
nanoparticles
nanoreinforced adhesives
nanoscience
nanotechnology
particleboard
wood composites
Novel composite materials having desired performance properties can be developed by nanotechnology. The major objective of this research was to produce nanomaterial-reinforced particleboard composites with enhanced physical and mechanical performance. Urea formaldehyde adhesive used to produce particleboard composites was reinforced with nanoSiO2, nanoAl2O3, and nanoZnO at loading level of 0%, 1%, and 3%. To evaluate physical properties density, thickness swelling, water absorption, and equilibrium moisture content were determined while modulus of rupture, modulus of elasticity, bonding strength, and screw withdrawal strength tests were carried out to evaluate mechanical properties of the particleboard composites. The results acquired in this work revealed that nanomaterial reinforcement technique significantly affected the physical and mechanical performance properties of the particleboard composites. The findings showed that the modulus of rupture, modulus of elasticity, bonding strength, and screw withdrawal resistance of the composites improved by all the nanomaterials used in this study, except 3% nanoZnO. It was also determined that using 1% nanoSiO2 or 1% nanoAl2O3 in the composites had the best results in the bonding strength and screw withdrawal resistance. The findings indicate that it is possible to produce novel wood composites by using proper nanomaterial type and loading level.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1207
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 319-334
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 319-334
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1207/1158
Derechos de autor 2015 Zeki Candan, Turgay Akbulut
oai:ojs.revistas.ubiobio.cl:article/1208
2017-09-20T17:27:24Z
MCT:art.
driver
Predicting moisture content from basic density and diameter during air drying of Eucalyptus and Corymbia logs
Vinha Zanuncio, Antônio José
Guimarães Carvalho, Amélia
Fernandes da Silva, Liniker
Tarcisio Lima, José
Trugilho, Paulo Fernando
Moreira da Silva, José Reinaldo
biomass
drying
wood
In air drying of Eucalyptus urophylla and Corymbia citriodora logs for the production of charcoal it is necessary to be able to predict when logs have reached the required moisture content of ≤ 35%. This study is aimed to produce models using basic density and diameter to predict the moisture content of Eucalyptus urophylla and Corymbia citriodora logs after 30, 60 and 90 days drying. 1,2 m long logs were taken at three different heights from three C. citriodora trees and three trees each from two E. urophylla clones (VM4 and Mn463). The 27 debarked, end sealed logs were air dried under cover for 90 days during which the change in moisture content was monitored. The relationship between density and drying was analyzed by Pearson’s correlation coefficient and the models for predicting the moisture content based on the basic density and diameter were produced. The density and the drying showed a high correlation coefficient. The coefficient of determination of the models was above 0,89 with a standard error lower than 6%. The use of the density and diameter to estimate the wood moisture content simplifies the production of the models, which can be used for Eucalyptus and Corymbia genetic materials.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1208
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 335-344
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 335-344
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1208/1159
Derechos de autor 2015 Antônio José Vinha Zanuncio, Amélia Guimarães Carvalho, Liniker Fernandes da Silva, José Tarcisio Lima, Paulo Fernando Trugilho, José Reinaldo Moreira da Silva
oai:ojs.revistas.ubiobio.cl:article/1209
2017-09-20T17:27:24Z
MCT:art.
driver
Application of aqueous two phase systems based on polyethylene glycol and sodium citrate for the recovery of phenolic compounds from eucalyptus wood
Xavier, Lucía
Freire, María Sonia
Vidal-Tato, Isabel
González-Álvarez, Julia
aqueous two-phase systems
biomass wastes
eucalyptus wood
natural antioxidants
polyethylene glycol
sodium citrate
This paper proposes an alternative way to intensify the exploitation of Eucalyptus wood wastes before valorisation for energy production. An aqueous two-phase system (ATPS) based on PEG 2000 and sodium citrate was investigated for the recovery of phenolic compounds that could act as natural antioxidants for applications including cosmetics, pharmaceuticals, food additives and other industrial applications. The influence of the tie line length (TLL) (26,1-46,1%), extraction temperature (25-65ºC), extraction time (90-390 min) and phase settlement time (1-8 h) were studied. Phenolic compounds were concentrated preferentially in the PEG-rich phase. A partition coefficient of 38 and a total phenols yield of 1,29 mg gallic acid equivalent/100 mg wood dry basis were obtained under the operational conditions selected: TLL, 46,1%, temperature 65ºC, extraction time 90 min and settlement time 1 h. Analysis of the extracts by RP-HPLC-ESI-TOF confirmed the presence of various phenolic compounds with demonstrated antioxidant activity: monogalloyl glucose, (-)-gallic acid, ellagic acid and quercetin 3-O-rhamnoside.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1209
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 345-354
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 345-354
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1209/1160
Derechos de autor 2015 Lucía Xavier, María Sonia Freire, Isabel Vidal-Tato, Julia González-Álvarez
oai:ojs.revistas.ubiobio.cl:article/1210
2017-09-20T17:27:24Z
MCT:art.
driver
Design and efficiency of a small-scale woodchip furnace
Torres-Fuchslocher, Carlos
Varas-Concha, Felipe
combustion efficiency
fixed grate
hearth appliances
stove design
wood chips
Although advances have been made in combustion efficiency in large-scale woodchip furnaces, less experimental results are available at the <20 kW range. Compact feed systems, as well as optimized grates and combustor chambers, continue to represent a challenge for the wider use of low-cost wood chips. This study describes the design and testing of a small-scale woodchip furnace that operates at a range of 9-18 kW. The efficiency test takes account of the feedstock Eucalyptus nitens, with three moisture contents and the combination of different air excess (λ) and primary/secondary air ratios. The results reveal a maximum of combustion efficiency of 85% for the low moisture content sample (16%) at λ=1,5 and 82% for samples with 29% and 40% moisture content, at λ= 2,0 and 2,1 respectively. The integrated heat exchanger proved to be highly efficient by reducing gas temperature by up to 69% prior to its exit.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1210
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 355-364
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 355-364
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1210/1161
Derechos de autor 2015 Carlos Torres-Fuchslocher, Felipe Varas-Concha
oai:ojs.revistas.ubiobio.cl:article/1211
2017-09-20T17:27:24Z
MCT:art.
driver
Effects of thinning on diameter, heartwood, density and drying defects of gmelina arborea
Vallejos, Jonathan
Moya, Roger
Serrano, Rafael
fast-growth
plantation wood
tree morphologic
wood density
wood properties
The effect of three levels thinning intensity in Gmelina arborea plantation on tree diameter, heartwood (diameter and percentage), wood density and drying defects (twist, crook, bow and check) was studied. Wood used for this study was obtained from eight-year-old plantations with thinning intensity of 60, 70 and 80% of initial density. Nine trees were selected from each trial. Results showed that tree diameter and wood density were similar in thinning intensity of 70 and 80%, but tree diameter from the plantation with 60% of thinning intensity was lower than plantation of 70 and 80%. Wood density of trees from 60% thinning intensity plantation was higher than 70 and 80%. Heartwood diameter and its percentage were the highest in 80% of thinning intensity. But not difference was found between 60 and 70% in heartwood (diameter and percentage). Finally, drying defects were not affected significantly by thinning intensity.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1211
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 365-372
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 365-372
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1211/1162
Derechos de autor 2015 Jonathan Vallejos, Roger Moya, Rafael Serrano
oai:ojs.revistas.ubiobio.cl:article/1212
2017-09-20T17:27:24Z
MCT:art.
driver
Treatability of Melia composita using vacuum pressure impregnation
Tripathi, Sadhna
Kumar Poonia, Pawan
melia composita
penetration
retention
treatability
ZiBOC
The performance of treated wood in the field is ultimately affected by retention and penetration of preservative in wood. In the present study, a new preservative system ZiBOC and a commercially used preservative copper-chrome-arsenate (CCA) were used for evaluation of treatability of Melia composita by the vacuum pressure method at different pressure levels in unsealed and end sealed specimens. The retention and penetration levels of both the preservatives were significantly different at (P< 0.05) in sapwood, heartwood and pith zones. Melia composita exhibited treatability class ‘C’ (21 – 42% penetration). The results revealed that longitudinal penetration in Melia composita was the dominant flow as examined by spot test for copper in unsealed and end sealed specimens.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1212
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 373-384
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 373-384
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1212/1163
Derechos de autor 2015 Sadhna Tripathi, Pawan Kumar Poonia
oai:ojs.revistas.ubiobio.cl:article/1213
2017-09-20T17:27:24Z
MCT:art.
driver
The effect of moisture content on the retention and distribution of nano-titanium dioxide in the wood
Mohammadnia Afrouzi, Younes
Marzbani, Pouya
Omidvar, Asghar Omidvar
full-cell process
impregnation
nanomaterial
populus deltoides
SEM image
When chemically treating wood products is used to enhance the properties, the distribution of chemicals in the wood can be more important than the amount of chemical uptake. In this research, two moisture contents (MC) (0 and 25%) were used to study the effect of MC on the nanomaterial retention and distribution in cottonwood (Populus deltoides) sapwood treated with nano-titanium dioxide. The wood samples were impregnated by a full-cell process at three levels of nano-TiO2 concentration: 0,5; 1 and 1,5%. The nanomaterial retention was calculated and SEM images were used to investigate the distribution of nanoparticles in the wood. The results showed that increasing the nano-TiO2 concentration caused more retention and the MC difference caused almost identical retention at 0,5 and 1% concentrations. Although the retention in the 0% MC samples was slightly more than those of 25% MC, this retention was significantly more in these samples (0% MC) at 1,5% concentration. SEM images indicated that the nanoparticles had more uniform distribution in the 0% MC samples than the 25% MC ones and the difference was clearly visible at 1,5% concentration. Low MC ranges (about 0%) are better than high MC’s to impregnate cottonwood samples with nano-TiO2 by using the full-cell process.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1213
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 385-390
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 385-390
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1213/1164
Derechos de autor 2015 Younes Mohammadnia Afrouzi, Pouya Marzbani, Asghar Omidvar Omidvar
oai:ojs.revistas.ubiobio.cl:article/1214
2017-09-20T17:27:24Z
MCT:art.
driver
Efecto del raleo sobre las propiedades anatómicas de la madera de Pinus taeda
Winck, Rosa Ángela
Fassola, Hugo Enrique
Área, María Cristina
cell wall thickness
microfibril angle
thinning intensity
tracheid length
ángulo microfibrilar
espesor de pared celular
intensidad de raleo
longitud de traqueidas
El raleo tiene implicancias económicas y técnicas para producción forestal y para la actividad industrial. El objetivo del estudio fue determinar la influencia de la intensidad de raleo sobre las propiedades anatómicas de la madera. Se trabajó con muestras tomadas a 1,30 m de altura, de 24 árboles proveniente de un ensayo de raleo en Pinus taeda de 20 años de edad, intervenido a los 3 años, con remoción del 0%, 50%, 75% y 87,5% de las plantas de la densidad inicial de plantación (1960 árboles/ ha). Se midieron diámetro a la altura de pecho, altura total, diámetro en la base de la copa viva y altura a la base de la copa viva, longitud de traqueidas, espesor de pared celular y ángulo microfibrilar. La longitud de traqueidas fue mayor en el tratamiento con 87,5% de raleo. Los tratamientos con 0% y 50% de raleo favorecieron la obtención de mayores valores de espesor de pared y menores valores de ángulo microfibrilar. Se concluyó que esta práctica silvícola altera a las propiedades anatómicas de la madera de Pinus taeda y que la longitud de traqueidas está fuertemente relacionada con el tamaño del árbol y con la longitud de la copa verde. AbstractThinning has technical and economic implications for both, forest production and industrial activity. The aim of this study was to determine the effect of thinning intensity on the anatomical properties of pine wood. Samples were taken at 1.30 m height, from 24 Pinus taeda trees of 20 years old, coming from a thinning treatment. The plantation was intervened at 3 years, with removal of 0%, 50%, 75% and 87,5% of the trees from the initial density (1960 trees/ha). The evaluated variables were: diameter at breast height, total height, diameter on the base of the live crown, height at base of live crown, tracheid length, cell wall thickness and microfibril angle. The tracheid length was higher in 87.5% thinning treatment. Treatments with 0 % and 50% thinning have favored the obtaining of higher values of cell wall thickness and lower values of microfibril angle. Results suggest that this silvicultural practice alters the anatomical properties of Pinus taeda wood and that tracheid length is strongly related to tree size and length of live crown.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1214
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 391-406
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 391-406
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1214/1165
Derechos de autor 2015 Rosa Ángela Winck, Hugo Enrique Fassola, María Cristina Área
oai:ojs.revistas.ubiobio.cl:article/1215
2017-09-20T17:27:24Z
MCT:art.
driver
Influence of moisture content on the wave velocity to estimate the mechanical properties of large cross-section pieces for structural use of scots pine from spain
Montero, M.J.
de la Mata, J.
Esteban, M.
Hermoso, E.
mechanical properties
moisture content
nondestructive techniques
pinus sylvestris
The aim of this research is to evaluate the influence of the moisture content of wood on stress wave velocity, as a nondestructive technique for estimating the mechanical properties of gross cross-section Spanish Scots pine (Pinus sylvestris) lumber for structural use. 26 100 x 150 x 3000 mm pieces from Segovia, Spain, were tested with different moisture content values, from 35,5 to 9%. Measurements of longitudinal stress wave velocity were carried out during the natural drying process by using three commercial portable devices based on ultrasonic, acoustic and vibrational techniques. The results can be summarized as three percentage points of decreasing velocity per percentage point of increased wood moisture content in the range from 11,8 to 21,4%: 0,48% for ultrasonic, 0,50% for acoustic wave and 0,65% for longitudinal vibration.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1215
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 407-420
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 407-420
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1215/1166
Derechos de autor 2015 M.J. Montero, J. de la Mata, M. Esteban, E. Hermoso
oai:ojs.revistas.ubiobio.cl:article/1216
2017-09-20T17:27:24Z
MCT:art.
driver
Optimización 3D de patrones de corte para trozas de Pino radiata con cilindro central defectuoso
Acevedo, Carlos
Ramos, Mario
Aguilera, Cristhian
Monsalve, Danny
cutting pattern
pinus radiata
pruned logs
sawmill optimization
aserrío
optimización
patrón de corte
trozas podadas
El objetivo de este estudio fue encontrar un método eficiente en tiempo y rendimiento que permita aumentar el aprovechamiento volumétrico y utilidad de los aserraderos que procesan trozas podadas de Pinus radiata, compenetrando la información externa entregada por un escáner de producción industrial y la simulación del Cilindro Central Defectuoso (CCD) en la constitución de una troza tridimensional, donde se estableció un patrón de corte optimo por medio de un algoritmo de programación dinámica. Se simuló el aserrado con una muestra de 30 trozas obtenidas aleatoriamente de un proceso de escaneo industrial. Los resultados fueron comparados con los obtenidos por una heurística, desarrollada por una empresa, basada en la práctica. El algoritmo de programación dinámica alcanzó un aprovechamiento de la materia prima del 64% y en términos relativos se obtuvo una utilidad neta promedio de 11 US$/troza. AbstractThe objective of this study was to find an efficient method that allows time and yield increase volume use and utility of the sawmills that process logs pruned Pinus radiata, linking external information provided by a scanner industry and simulation of Cylindrical Defective Core (CDC) in the constitution of a three-dimensional log, where the optimal cutting pattern was established by means of a dynamic programming algorithm. Sawing was simulated on a sample of 30 logs obtained randomly industrial process of scanning. The results were compared with those obtained by a heuristic developed by a company. Dynamic programming algorithm achieved a yield of the raw material of 64% and an average relative net utility of 11 US$/log was obtained.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1216
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 421-434
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 421-434
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1216/1167
Derechos de autor 2015 Carlos Acevedo, Mario Ramos, Cristhian Aguilera, Danny Monsalve
oai:ojs.revistas.ubiobio.cl:article/1217
2017-09-20T17:27:24Z
MCT:art.
driver
Changes in the chemical structure and decay resistance of heat-treated narrow-leaved ash wood
Yalcin, Mesut
Ibrahim Sahin, Halil
chemical structure
decay resistance
fraxinus angustifolia
thermal modification
We analyzed the effects of heat treatment on the chemical structure of wood from narrow-leafed Ash (Fraxinus angustifolia), a fast-growing and economically valuable species. We also analyzed the effects of heat treatment on the wood’s resistance to four decay fungi. Narrow-leafed Ash wood samples were heated with saturated steam to 140, 180, 200, and 220°C for 2, 4, and 6 h. The relative contents of extractable components were analyzed, as well as the levels of holocellulose, cellulose, and lignin. In addition, the density, equilibrium moisture content, and pH of the samples were measured. To determine the effects of heat treatment on resistance to decay fungi, the samples were exposed to the white rot fungus Trametes versicolor, dry rot fungus Serpula lacrymans, and the brown rot fungi Coniophora puteana and Gloeophyllum trabeum. Changes in the chemical composition of the wood due to heat treatment were correlated with increased resistance to fungal decay. While the hemicellulose content was dramatically reduced with increasing temperature and treatment duration, the lignin content increased proportionately. Thus, heat treatment is an environmentally friendly method of preserving narrow-leafed Ash wood against various decay fungi.
Universidad del Bio-Bio
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1217
Maderas-Cienc Tecnol; Vol. 17 No. 2 (2015); 435-446
Maderas-Cienc Tecnol; Vol. 17 Núm. 2 (2015); 435-446
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1217/1168
Derechos de autor 2015 Mesut Yalcin, Halil Ibrahim Sahin
oai:ojs.revistas.ubiobio.cl:article/1219
2017-09-20T17:31:57Z
MCT:art.
driver
Chemical modification of tannin/furanic rigid foams by isocyanates and polyurethanes
Li, X.
Basso, M.C.
Fierro, V.
Pizzi, A.
Celzard, A.
tannin/furanic rigid foams
isocyanate modification
polyurethane modificaton
microstructure
mechanical properties
Tannin/furanic rigid foams were modifi ed by either polymeric 4,4’ diphenylmethane diisocyanate (pMDI) or a one-component polyurethane still presenting reactive isocyanate groups (PUR). Several diff erent sequences of mixing the isocyanate and polyurethane with the chemicals used to prepare tannin-based foams were tested. Scanning electron microscopy (SEM) showed that addition of either pMDI or PUR yielded a more ordered microstructure of the foam and a larger cell size. Series of two diff erent cell sizes were noticed: those obtained by the evaporation of the blowing agent used for classical tannin-based foams and those caused by the formation of CO2 issued by the reaction of the isocyanate groups with water. Th e cell size, density, thermal conductivity and mechanical property of tannin/furanic foams were controlled by changing the amount of blowing agent and weight fraction of pMDI. Th e cell size of pMDI modifi ed foams was largest when the weight fraction of pMDI was 5% and kept decreasing as the pMDI percentage became higher. Th e density of the foams increased with the increase of the weight fraction of pMDI. Th e addition of pMDI increased slightly the thermal conductivity of tannin/furanic foam with the foams still presenting good thermal insulation. Moreover, the addition of pMDI in tannin/furanic foams improved markedly the foam’s mechanical properties.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1219
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 257-266
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 257-266
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1219/1170
Derechos de autor 2015 X. Li, M.C. Basso, V. Fierro, A. Pizzi, A. Celzard
oai:ojs.revistas.ubiobio.cl:article/1220
2017-09-20T17:31:57Z
MCT:art.
driver
Relationships between microfibril angle, modulus of elasticity and compressive strength in Eucalyptus wood
Gherardi Hein, Paulo Ricardo
Tarcísio Lima, José
MFA
stiffness
compressive strength
timber
variability
Many traits are known to be important in determining the value of Eucalyptus wood as sawn tim-ber. The commercial importance of the microfi bril angle (MFA) for wood quality is well established for a range of softwoods, but is less clear for hardwood species. For instance, the relationships of MFA with wood stiffness and compressive strength are unknown in Eucalyptus. Therefore, the aim of this study was to evaluate the correlation between MFA and the modulus of elasticity (Ec0,m) in compres-sion parallel to grain and compressive strength (Fc0,k) using juvenile wood of Eucalyptus grandis from fast-growing plantations. The correlation between wood stiffness and compressive strength was high (0.91). The cellulose microfi bril angle presented a correlation of -0.67 with wood stiffness and of -0.52 with compressive strength in Eucalyptus juvenile wood. MFA was found to be important in de-termining the mechanical behaviour of wood and appears to be a useful parameter to indicate wood stiffness and strength in juvenile Eucalyptus from short-rotation plantations.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1220
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 267-274
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 267-274
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1220/1171
Derechos de autor 2015 Paulo Ricardo Gherardi Hein, José Tarcísio Lima
oai:ojs.revistas.ubiobio.cl:article/1221
2017-09-20T17:31:57Z
MCT:art.
driver
Madera de compresión en Pinus radiata III: Propiedades de pulpas kraft
Diaz-vaz, J.E.
Ananias, R. A.
Valenzuela, L.
Torres, M.
Rodriguez, S.
reaction wood
opposite wood
unbleached pulp
bleached pulp
pulp yield
density
tension index
tear index
burst index
madera de reacción
madera opuesta
pulpa cruda
pulpa blanqueada
rendimiento de pulpa
densidad
índice de tensión
Estudios anteriores en estos mismos árboles de Pinus radiata con fustes levemente inclinados, demostraron que la madera de compresión leve que ellos exhibían presentaba: traqueidas más cortas, mayor densidad, mayor proporción de lignina, mayor proporción de extraíbles en etanol tolueno y menor proporción de alfa celulosa que la madera opuesta y que la madera de árboles sin madera de compresión.En el presente estudio se analiza las propiedades pulpables de la madera de compresión y la de sus respectivas maderas opuestas de los quince árboles de Pinus radiata estudiados, crecidos en suelos de arena húmeda en Chile. Se estudió separadamente la madera de compresión y la madera opuesta. Con distintas proporciones, de entre 0, 40, 70 y 100 % de madera de compresión y madera opuesta, se efectuaron pulpajes kraft para cada una de las mezclas.De estos pulpajes con y sin blanqueo se informan valores de 501 y 695 kg/m3 de densidad; 28 a 51 Nm/g en índice de tensión, 18 a 25 mNm2/g en índice de rasgado, 2.2 a 4.1 kPam2/g en índice de explosión y rendimiento de 44 a 50.6 % en las mezclas de la pulpa estudiada.En la pulpa cruda de MC, de la madera pulpable y de la madera exterior aserrable, se registró me-nor densidad, mayor índice de tensión, de rasgado y de explosión, en comparación con los resultados obtenidos en la pulpa cruda de MO. En el caso de las pulpas blanqueadas, la densidad y el índice de tensión resultaron mayores en la MC.En el resto de las propiedades las diferencias entre MC y MO fueron oscilantes y reducidas. El aumento de la proporción de MC en la mezcla de MC y MO, produjo una reducción de rendimiento. Los rendimiento de las mezclas de la madera pulpable indicaron para el 100 % de MO un 50.6 % y para el 100% de MC un 44 %: En los casos de las pulpas de madera exterior aserrable el 100% de MO tuvo un rendimiento de de 48.4% en cambio el 100% de la MC registró un 44.3%.Los resultados obtenidos indicaron que la MC leve, que se encuentra en árboles con inclinaciones menores, tuvo un efecto de menor magnitud que él que se produce en la MC severa sobre las características y rendimiento de la pulpa kraft. AbstractPrevious studies with radiata pine trees growing slightly leaned towards one side showed that they have small amounts of compression wood with different characteristics than the opposite wood at the other side of the annual rings. These differences include shorter tracheids, higher density, higher proportion of lining, higher proportion of extractives in toluene ethanol, and a smaller amount of alpha-cellulose.The present study compares the properties of kraft pulp, with and without bleaching, for mixtures of compression and opposite wood obtained from fifteen 22-year-old radiata pine trees that grew in humid sand soils of Chile. The kraft pulp mixture was studied for different proportions of 0, 40, 70 and 100% compression wood. Considering all mixtures with and without bleaching, the study reports values between 501 and 695 kg/m3 density, 28 and 51 Nm/g tension index, 18 and 25 mNm2/g tear index, 2,2 and 4,1 kPam2 burst index, and 44% and 50,6% pulp yield.It was found that the pulp without bleaching from compression wood (for both the internal pulp and the external lumber areas) had lower density, but higher tension, tear, and burst indexes. The pulp with bleaching from compression wood had both higher density and tension index, but the other properties only show small random differences with respect to opposite wood.A higher proportion of compression wood in the mixture reduced pulp yield. The yield for the internal pulp area was 50,6 % with pure opposite wood and 44% with pure compression wood, while the yield for external lumber area was 48,4% with pure opposite wood and 44,3% with pure compression wood. I was concluded, however, that the relatively small amount of compression wood found in these trees had only a minor effect in the properties and yield of kraft pulp.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1221
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 275-288
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 275-288
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1221/1172
Derechos de autor 2015 J.E. Diaz-vaz, R. A. Ananias, L. Valenzuela, M. Torres, S. Rodriguez
oai:ojs.revistas.ubiobio.cl:article/1222
2017-09-20T17:31:57Z
MCT:art.
driver
Efecto de la tasa de compresión en la morfología de grietas de debobinado para chapas de Eucalyptus nitens
Acevedo, Andrés
Bustos, Cecilia
Pierre Lasserre, Jean
Gacitúa, William
lathe checks
nose bar pressure
veneers
peeling process
eucalyptus nitens
grietas de debobinado
tasa de compresión
chapas
debobinado
El objetivo de este estudio fue evaluar el efecto de tres tasas de compresión (TC) en la morfología de grietas de debobinado en chapas de Eucalyptus nitens para la fabricación de tableros contrachapados. Chapas secas se obtuvieron desde un proceso de debobinado, con 1.8 mm de espesor a tres tasas de compresión TC1=0.5 %; TC2=3.5 % y TC3=5 %, las que se consiguieron ajustando la barra de presión y el cuchillo del torno debobinador marca Cremona de una planta de contrachapados del sur de Chile. Se obtuvieron probetas en forma aleatoria de los tres tipos de chapas procesadas. Fotografías fueron tomadas en el espesor de las chapas para el posterior procesamiento de imágenes. En el análisis morfológico de las grietas se evalúo: largo, área y frecuencia en las probetas para las tres tasas de compresión estudiadas. El análisis morfológico de imágenes mostró que existe una disminución del largo y profundidad de las grietas, así como también del área de grietas, cuando se aumenta la tasa de compresión. Diferencias significativas fueron halladas entre los niveles 0.5 % y 5 % de tasa de compresión. Esto implica que al aumentar la tasa de compresión, a través de un ajuste que involucra una menor distancia entre la barra de presión y el cuchillo debobinador, se obtienen chapas de mejor calidad, más rígidas y con una reducción del agrietamiento superficial en el tablero final. Abstract The objective of this study was to evaluate the effect of three nose bar pressure (TC) in the morphology of the lathe checks in Eucalyptus nitens veneers for the manufacture of plywood. Dried veneers were obtained from a peeling process, 1.8 mm thick three nose bar pressure TC1= 0.5%, TC2andTC3= 3.5%= 5%, which were obtained by adjusting the pressure bar and peeling knife of Cremona the in a plywood plant in southern Chile. Samples were obtained randomly from the three types of veneers processed. Photographs were taken in the veneer thickness for subsequent image processing. In the morphological analysis of the cracks was evaluated: length, area and frequency in the samples for the three nose bar pressure studied. Morphological analysis of images showed that a decrease in the length and depth of the lathe check, as well as the area, when the nose bar pressure increases. Significant differences were found between 0.5%and 5%levels of nose bar pressure. This implies that increasing the nose bar pressure, through a setting that involves a smaller distance between the pressure bar and peeling knife, you get better quality veneers, more rigid and with a reduction of surface cracking in the final plywood.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1222
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 289-302
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 289-302
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1222/1173
Derechos de autor 2015 Andrés Acevedo, Cecilia Bustos, Jean Pierre Lasserre, William Gacitúa
oai:ojs.revistas.ubiobio.cl:article/1223
2017-09-20T17:31:57Z
MCT:art.
driver
Análisis del comportamiento reológico y termo-higromecánico en probetas de tableros tensados de madera para puentes a condiciones ambientales variables
Figueroa, Macarena
Bustos, Cecilia
Dechent, Peter
Reyes, Laura
Cloutier, Alain
Giuliano, Mario
stress-laminated timber bridge deck
bar stress
preservation treatments
pinus radiata D.Don
puentes tensados
tensión en las barras
tratamientos de preservación
La madera presenta un comportamiento termo-higromecánico cuando se somete a la acción conjunta de variaciones de temperatura, humedad relativa y carga mecánica. Los tableros tensados de madera presentan pérdidas de fuerza en la barra de tensado debido principalmente a la relajación de la tensión y a la contracción de la madera, aumentando con los cambios de humedad y temperatura de ésta. El objetivo de este estudio fue estudiar el comportamiento reológico de tableros tensados de madera de pino radiata (Pinus radiata D. Don) sometidos a cambios de temperatura y humedad relativa. Un total de 16 probetas fueron previamente tratadas con diferentes tratamientos de preservación, las cuales fueron sometidas a cuatro ciclos de temperatura y humedad relativa en una cámara de clima. La deformación de las probetas y la tensión de las barras de acero fueron medidas. Los resultados mostraron que la variación de la temperatura y de la humedad tiene una fuerte influencia en la variación de la tensión de las barras tensoras. Los retensados minimizaron la pérdida de tensión de las barras. Además, no se observaron evidencias de fluencia termo-higromecánica ni relajación de la tensión de las muestras de puentes tensados en este estudio. AbstractWood material has a thermo-hygromechanical behaviour because its deformation depends on the combined action of temperature, relative humidity and mechanical load variations. Stress-laminated timber bridge deck show a reduction of stress in the tension bars mainly due to the relaxation and shrinkage of wood, increasing with moisture content and temperature changes within the wood. The aim of this research was to study the rheological behavior of stress-laminated timber bridge deck samples under temperature and relative humidity variations. A total of 16 samples were previously treated with four types of preservative treatments, which were subjected to four cycles of temperature and relative humidity in a climate chamber. Wood samples deformation and stress in the steel bars were measured. The results showed a significant stress reduction in the steel bar during the summer season and a significant increase during the winter season. The results also showed significant differences between the deformations of control samples compared to the preservative treated samples for each cycle. However, for interlaminar stress, differences were significant only in the winter season. Moreover, for both deformation and interlaminar stress, no significant differences between cycles three and four were found. Therefore there is no evidence of thermo-hygromechanical creep or relaxation of wood in the conditions considered in this study.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1223
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 303-320
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 303-320
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1223/1174
Derechos de autor 2015 Macarena Figueroa, Cecilia Bustos, Peter Dechent, Laura Reyes, Alain Cloutier, Mario Giuliano
oai:ojs.revistas.ubiobio.cl:article/1224
2017-09-20T17:31:57Z
MCT:art.
driver
Caracterización nanomecánica de la estructura celular y anatómica de Eucalyptus nitens y su relación con la frecuencia de grietas y rajaduras en madera redonda
Valenzuela, Paulina
Bustos A, Cecilia
Pierre Lasserre, Jean
Gacitúa, William
nanomechanical properties
nanoindentations
wood anatomy
wood ultrastructure
cracks
propiedades mecánicas
nanoindentaciones
anatomía de la madera
ultraestructura de la madera
fracturas
El objetivo de este trabajo fue localizar el mínimo volumen en árboles de E. nitens que caracterice el comportamiento mecánico y anatómico para un muestreo no destructivo. Los árboles fueron cortados desde Mulchén y Yungay en la región del Bío-Bío. Se establecieron relaciones entre las propiedades nanomecánicas y la anatomía de la madera con el agrietamiento y las fracturas mayores (rajaduras). Se obtuvieron los parámetros razón de ductilidad (E/H) y módulo de resiliencia (ur), medidos en la capa S2 y lamela media. Los resultados mostraron que el volumen representativo de los árboles de E. nitens se encontraban a 3 metros de altura desde la base de los árboles y desde el anillo 5 al 7. Al mismo tiempo, se logró establecer que la lamela media es más frágil que la capa S2 de la pared celular. Se determinó una relación entre la caracterización de los vasos y el nivel de agrietamiento de la madera. Esto es, a mayor área y diámetro de los vasos y a menor número de éstos, el nivel de agrietamiento fue mayor. Las grietas se concentraron principalmente en los primeros metros de altura del árbol, existiendo una buena relación con el E/H de la lamela media, que mostró un cambio significativo a los 3 metros de altura. Las grietas en los anillos de crecimiento se centraron notoriamente en madera de temprana y en los anillos del 5 al 7 (desde médula a corteza). AbstractThe aim of this study was to define the minimum volumen in trees of E. nitens that characterize the mechanical and anatomy behavior for non-destructive sampling. The trees were cut from sites located in Mulchen and Yungay in the region of Bío Bío. Relationships were found between nano-mechanical properties, wood anatomy and wood cracks and fractures. The response variables were the ductility ratio (E/H) and the modulus of resilience (ur), in the S2 layer and middle lamella. The results showed that the representative volume, from E. nitens families is at 3 meter high from base of the trees and between the 5th to 7th annual rings. Also, it was established that the middle lamella is more brittle than the S2 layer. Relationship between the vessels morphology and the level of the wood cracking was observed. A high area of vessels, a high vessel diameter and a small frequency of them, resulted in high cracking. The cracks were mainly concentrated in the first meters of tree, were we found a good relationship of this response variable with the E/H ratio for the middle lamella; there was a significant change of this ratio at 3 meters high. Cracks were evident on earlywood and from the 5th to the 7th annual rings.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1224
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 321-338
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 321-338
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1224/1175
Derechos de autor 2015 Paulina Valenzuela, Cecilia Bustos A, Jean Pierre Lasserre, William Gacitúa
oai:ojs.revistas.ubiobio.cl:article/1225
2017-09-20T17:31:57Z
MCT:art.
driver
Determinación de un elemento de volumen representativo de probetas de tablero tensado
Sepúlveda, Daniela
Gacitúa, William
Bustos, Cecilia
Dechent, Peter
Cloutier, Alain
mechanical properties
compression perpendicular
nanoindentation
pinus radiata
eucalyptus nitens
propiedades mecánicas
compresión perpendicular
nanoindentaciones
El objetivo de este estudio fue definir un elemento de volumen representativo para caracterizar las propiedades mecánicas de probetas de tableros tensados de Pinus radiata D. Don y de Eucalyptus nitens. La determinación del elemento de volumen representativo permitió identificar la sección más pequeña de las probetas que presenta las particularidades de este material compuesto y por consiguiente, representa a la probeta en su conjunto. Para esto, las propiedades nanomecánicas de las paredes celulares y lamela media fueron determinadas por nanoindentaciones. Este estudio se desarrolló en dos etapas. En la primera etapa, el anillo de crecimiento representativo de las piezas de madera bajo compresión perpendicular a la fibra, fue determinado. En la segunda etapa, el tablón representativo de la probeta de tablero tensado sometido a compresión a largo plazo, fue determinado. Los resultados de la primera etapa, mostraron que no existe una tendencia específica de las propiedades nanomecánicas a través de los anillos de crecimiento en la sección transversal de las piezas de Pinus radiata y Eucalyptus nitens bajo compresión perpendicular a la fibra. En la segunda etapa, se estableció que los esfuerzos de compresión a largo plazo en la probeta de tablero tensado principalmente afectaron las propiedades nanomecánicas de la estructura celular de los tablones exterior y central de la probeta. Lo anterior permitió establecer que el elemento de volumen representativo de una probeta de tablero tensado se localizó en la madera temprana del anillo de crecimiento más alejado a la médula en la sección transversal del tablón central. AbstractThe aim of this study was to define a representative volume element to characterize the mechanical properties of stress-laminated deck specimens of radiata pine and Eucalyptus nitens. The determination of the representative volume element allowed to identify the smallest representative section of the stress-laminated deck. For this, the nanomechanical properties of the cell walls and middle lamellas were determined by nanoindentations. This study was conducted in two phases. In the first phase, the growth ring representative of the pieces of wood under compression perpendicular to the grain was determined. In the second phase, the board representative of the stress-laminated deck specimens subjected to long-term compression loads and variable environmental conditions was determined. The results obtained in the first phase of the study showed that there was no specific tendency of the nanomechanical properties through growth rings in the cross-section of Pinus radiata and Eucalyptus nitens specimens subjected to compression loads perpendicular to the grain. In the second phase of the study, it was found that long-term compression loads in stress-laminated deck specimens mainly affect the mechanical properties of the cellular structure of exterior and central boards. Finally, the representative volume element in a stress-laminated deck specimen was found in the earlywood of the growth ring farthest to the pith in the cross section of the central board.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1225
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 339-360
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 339-360
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1225/1176
Derechos de autor 2015 Daniela Sepúlveda, William Gacitúa, Cecilia Bustos, Peter Dechent, Alain Cloutier
oai:ojs.revistas.ubiobio.cl:article/1227
2017-09-20T17:31:57Z
MCT:art.
driver
Efecto del raleo en el crecimiento y algunas propiedades de la madera de Eucalyptus nitens en una plantación de 15 años
Díaz Bravo, Sandro
Espinosa, Miguel
Valenzuela, Luis
Cancino, Jorge
P. Lasserre, Jean
e. nitens
thinning
basic density
modulus of elasticity
growth stress
raleo
densidad básica
módulo de elasticidad
tensiones de crecimiento
El raleo tiene implicancias económicas y técnicas tanto para producción forestal como para la actividad industrial. En el presente estudio se realizó la evaluación de un ensayo de intensidad de raleo en E. nitens, de 15 años de edad, intervenido a los 7 y 9 años, con densidades residuales de 300, 400, 500, 700 y un tratamiento testigo con 1070 arb ha-1. El objetivo es conocer el efecto del raleo en el diámetro y altura de los árboles, coeficiente de esbeltez, en los índices de competencia área potencial-mente aprovechable (APA), área de proyección de copas (APC) y en las propiedades de la madera, densidad básica, módulo de elasticidad dinámico (MOEd) y las tensiones de crecimiento evaluadas con la deformación residual longitudinal de la fibra (DRL).Los resultados mostraron que el raleo afectó el diámetro, coeficiente de esbeltez, APA y APC, no así la altura. El raleo tampoco tuvo efecto en la densidad básica de la madera y en el DRL. Por otra parte el MOEd fue afectado por el raleo, pero sin mostrar claras tendencias respecto de su intensidad. El efecto de la orientación del fuste en el MOEd y el DRL, mostró valores significativamente mayores en la orientación Sur. AbstractThinning has significant technical and economic implications for both forest managers and industrial end users. In the present study a 15 year old Eucalyptus nitens thinning experiment was evaluated. Thinnings operations were carried out at 7 and 9 years, with final stockings of 300, 400, 500, 700 and a control treatment of 1070 trees ha-1. The aim was to determine the effect of thinning on (i) stem diameter and tree height, stem slenderness ratio, (ii) competition indices: potentially usefull area (PUA), crown projection area (CPA) and (iii) wood properties: basic density, dynamic modulus of elasticity (Moed) and growth stresses evaluated using the residual deformation of the fiber length (DRL).The results showed that thinning affected tree diameter, slenderness index, PUA and CPA, but not total height. Thinning had no effect on basic density and DRL. On the other hand Moed was affected by thinning, but did not show a clear trend with thinning intensity. The effect of the stem orientation on DRL and Moed showed significantly higher values on the South side.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1227
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 373-388
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 373-388
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1227/1178
Derechos de autor 2015 Sandro Díaz Bravo, Miguel Espinosa, Luis Valenzuela, Jorge Cancino, Jean P. Lasserre
oai:ojs.revistas.ubiobio.cl:article/1228
2017-09-20T17:31:57Z
MCT:art.
driver
Laboratory experiments on hygrothermal behaviour of real-scale timber walls
Rafi diarison, Helisoa
Mougel, Eric
Nicolas, Alexis
timber walls
hygrothermal behaviour
climatic chamber
thermal comfort
experiments
hygroscopic material
Hygrothermal performance of massive wood and wooden materials used as structural purposes in building envelope are measured by means of laboratory tests. For this purpose, hygrothermal short-time behaviour of two massive timber walls exposed to summer climatic conditions were investigated. A double climatic chamber simulating real on-site conditions was designed and built at the LERMAB/ENSTIB site in Epinal and used during wall behaviour assessment. Temperature and humidity variations with time were measured at diff erent locations to determine profiles evolution of the investigated wall layers. Our results showed a contribution of wood and wooden insulation products in improving indoor thermal climate, as these materials allow a decrease and a significant delay of the important temperature variation of outdoor climate. Laboratory result was also compared to field measurement for the cross-laminated wall system, time lag values for north and south walls showed that solar radiation have a non negligible eff ect on temperature propagation within the wall. Th e variation of absolute humidity of the air in the cavity around humidity sensors installed in wall layers shows significant dependence with temperature variation. Th is phenomenon is consistent with the storage or realising of humidity during hygroscopic equilibrium between wood-based materials and its surrounding air.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1228
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 389-402
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 389-402
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1228/1179
Derechos de autor 2015 Helisoa Rafi diarison, Eric Mougel, Alexis Nicolas
oai:ojs.revistas.ubiobio.cl:article/1229
2017-09-20T17:31:57Z
MCT:art.
driver
Valorization of moroccan olive stones by using it in particleboard panels
Elbir, M.
Moubarik, A.
Rakib, E.M.
Grimi, N.
Amhoud, A.
Miguel, G.
Hanine, H.
Artaud, J.
Vanloot, P.
Mbarki, M.
decay resistance
olive stone
particleboard
phenolic compounds
The main objective of this work was to find new applications to valorize olive stones (endocarp and seed). In order to improve knowledge on olive stones, the phenolic compounds concentration of three varieties of Moroccan olive trees: Moroccan Picholine, Menara and Haouzian were studied. Olive stones of three varieties were characterized by Fourier Transform Mid Infrared Spectroscopy (FT-MIR). Total phenolic compounds are quantifi ed aft er solid-liquid extraction by an assay of Folin-Ciocalteu. Moroccan Picholine stones (11.32 mg GAE/g DM) have a higher content of total phenolic compounds than Haouzia stones (4.55 mg GAE/g DM) and Menara stones (3.56 mg GAE/g DM). Thermogravimetric analysis indicates that up to 195°C; there is no degradation of the stones. The biocide performance on agar-agar was tested with decay fungi. Biodegradation studies show that the most interesting results are obtained with Moroccan Picholine stones. The presence of Moroccan Picholine in a particleboard panels improves the total resistance of the particleboard panels against both Coriolus versicolor and Coniophora puteana rot fungi.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1229
Maderas-Cienc Tecnol; Vol. 14 No. 3 (2012); 361-372
Maderas-Cienc Tecnol; Vol. 14 Núm. 3 (2012); 361-372
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1229/1180
Derechos de autor 2015 M. Elbir, A. Moubarik, E.M. Rakib, N. Grimi, A. Amhoud, G. Miguel, H. Hanine, J. Artaud, P. Vanloot, M. Mbarki
oai:ojs.revistas.ubiobio.cl:article/1230
2017-09-20T17:32:19Z
MCT:art.
driver
Surface properties of mdf coated with calcite/cla y and effects of fire retardants on these properties
Istek, Abdullah
Aydemir, Deniz
Eroglu, Hudaverdi
coated MDF
pigment coating
calcite
clay
surface properties
fire retardants
The coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Different application methods are used for the coating of MDF surface. Th ese are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the effects of fi re retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as fi re retardant were added to calcite /melamine formaldehyde with 22% mixture. So, the effects of fi re retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1230
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 135-144
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 135-144
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1230/1181
Derechos de autor 2015 Abdullah Istek, Deniz Aydemir, Hudaverdi Eroglu
oai:ojs.revistas.ubiobio.cl:article/1231
2017-09-20T17:32:19Z
MCT:art.
driver
Why simulate a sample of recycled wood?
Bouslamti, A.
Irle, M.A.
Belloncle, C.
Salvador, V.
Bondu, M.
Hulot, S.
Caron, B.
recovered wood
particle size
sample size
heavy metals
AAS
ICP-AES
Wood products follow the same cycle as other materials: manufacture, use and disposal. For certain applications, chemical additives are added to wood to increase its durability against biological and physical attack. At the end of life, waste wood is chipped or crushed before being recovered as raw material for new products or as fuel for energy. In recycled wood, there is the potential that some wood particles are contaminated by hazardous substances, such as organic or heavy metal preservatives. Therefore there is a need for a quality control method of assessing recovered wood that is on the one hand sufficiently precise and on the other not too expensive to preclude the use of recycling wood in to new products.This paper covers some preliminary research that is part of a large study that aims to develop a robust analytical method for recovered wood. However the extreme variability of recovered wood makes it difficult to develop such protocols on real recovered wood samples. Consequently, model chip piles with known contamination levels were created to simulate real world recovered wood samples.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1231
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 145-154
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 145-154
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1231/1182
Derechos de autor 2015 A. Bouslamti, M.A. Irle, C. Belloncle, V. Salvador, M. Bondu, S. Hulot, B. Caron
oai:ojs.revistas.ubiobio.cl:article/1232
2017-09-20T17:32:19Z
MCT:art.
driver
Efficiency of natural wood extractives as wood preservatives against termite attack
Syofuna, A.
Banana, A.Y.
Nakabonge, G.
durability
deterioration
preservation
extractives
Wood extractives play a major role in the protection of wood against termite and fungal attack. Wood extractives from three hard wood species of Milicia excelsa, Albizia coriaria and Markhamia lutea that are known to be very resistant against termite attack and fungal decay were studied to assess their role as wood preservatives in Uganda. Acetone, hexane and distilled water were used in the extraction of these compounds from the outer heartwood of the selected durable species. Extraction was done using a soxhlet extractor. The extractives obtained were used to treat Pinus caribaea and Antiaris toxicaria species known to be susceptible to termites and fungal attack. Treated blocks were then exposed to Macrotermes bellicosus termites in the fi eld. It was observed that wood extracts used as preservatives improved the resistance of less durable samples to termite attack by 50% compared to the controls. It was also observed that removal of extractives decreased resistance of the durable samples. It can be concluded that wood extractives contribute greatly to the protection of less durable wood species against termite attack.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1232
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 155-164
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 155-164
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1232/1183
Derechos de autor 2015 A. Syofuna, A.Y. Banana, G. Nakabonge
oai:ojs.revistas.ubiobio.cl:article/1233
2017-09-20T17:32:19Z
MCT:art.
driver
Preservación de madera tratada con Zn y Mn y efectividad de tratamiento antilixiviante con bórax
Ibáñez, C.
Mantero, C.
Silva, L.
Rabinovich, M.
Escudero, R.
Franco, J.
zinc
borax
wood preservers
manganese
stakes graveyard
bórax
preservantes para madera
manganeso
cementerio de estacas
Continuando con el estudio del uso de una solución obtenida en un proceso de reciclado de baterías domésticas como preservante para madera, se estableció un primer cementerio de estacas basado en la norma EN 252, que evalúa la durabilidad adquirida por probetas de Pinus taeda L. Dicha solución es ácida, contiene 32 g l-1 de Zn y 15 g l-1 de Mn como sulfatos, libre de metales pesados; en ensayos de laboratorio ha demostrado propiedades funguicidas e insecticidas específi cos, a concentraciones menores a 3% en Zn (máxima concentración obtenida del reciclado). A las probetas tratadas con la mencionada solución por el método de célula llena, se les realizó un tratamiento posterior antilixiviante con bórax al 2%, por pincelado y por célula. Se comparó la durabilidad natural y la adquirida, con dicha solución (con o sin bórax), con arseniato de cobre cromatado (CCA) a dos retenciones. A 32 meses del inicio del ensayo, las concentraciones de Zn de 3% y mayores con el bórax aplicado por el método de célula llena son las más efectivas. Se analizaron además los agentes de deterioro de madera (insectos, hongos y bacterias) presentes en las probetas. AbstractAs part of the study of the application of a solution obtained from a domestic batteries recycling process as a wood preservative, a field stakes test was established to assess the acquired durability in loblolly pine (Pinus taeda L.) specimens following the internationally accepted standard EN 252. This solution is acidic, containing 32 g l-1 Zn and 15 g l-1 of Mn as sulfates and free of heavy metals; in laboratory tests the solution proved to have specific fungicidal and insecticidal properties against organisms that degrade wood, at concentrations lower than 3% Zn (the highest concentration obtained from the recycling process). The specimens treated by the full cell method with the mentioned solution were afterwards treated with 2% in borax by the full cell method and by brushing in order to prevent leaching. Natural and acquired durability are compared using different concentrations of the studied solution as well as chromated copper arsenate (CCA) at two different retention levels. At 32 months, 3 % and higher concentrations of Zn and borax applied by full cell method showed to be the most effective. Main degrading agents (insects, fungi and bacteria) found in the specimens are also described.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1233
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 165-174
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 165-174
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1233/1184
Derechos de autor 2015 C. Ibáñez, C. Mantero, L. Silva, M. Rabinovich, R. Escudero, J. Franco
oai:ojs.revistas.ubiobio.cl:article/1234
2017-09-20T17:32:19Z
MCT:art.
driver
Efecto del rectificado y desgaste de cuchillos en la calidad superficial de molduras de Pino radiata
Aguilera, Alfredo
Fernández, Christopher
fuzzy grain
torn grain
jointing
radiata pine
fibra encontrada
fibra astillada
rectificado
pino radiata
Se estudia el efecto que ejerce el talón de rectificado de cuchillos en acero rápido sobre la calidad superficial de molduras sólidas de pino radiata. Se analizan los defectos fibra encontrada (grano velloso o fuzzy grain) y fibra astillada (grano arrancado o torn grain) en molduras de perfil plano que se generan en el proceso de moldurado. Se evaluó la relación talón de rectificado – calidad superficial, a través de dos procedimientos, en el primero se realiza el rectificado en forma sistemática, y en el segundo sólo una vez, al inicio del proceso, para en ambos casos cuantificar los defectos generados en las piezas. Los resultados indican que la aparición de fibra encontrada y fibra astillada se pueden relacionar con la distancia de corte y con el estado del talón de rectificado, asimismo, la calidad del material de corte y las condiciones de operación deben tenerse en cuenta ya que de estos factores depende el rendimiento del proceso. AbstractThe effect exerted by the land of jointing of high speed steel knives is studied on the surface quality of radiata pine solid moldings. Fuzzy grain and torn grain are analyzed on at molding profile. To evaluate these defects, the relationship land of jointing - surface quality was assessed through two procedures, on the first the jointing was done systematically, and on the second only once, early in the process. The results indicate that fuzzy grain and torn grain are related to cutting distance and jointing process, the quality of the cutting material and operating conditions must be taken into account because of these factors depends the process performance as well.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1234
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 175-184
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 175-184
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1234/1185
Derechos de autor 2015 lfredo Aguilera, Christopher Fernández
oai:ojs.revistas.ubiobio.cl:article/1235
2017-09-20T17:32:19Z
MCT:art.
driver
Wettability and surface roughness characteristics of medium density fiberboard panels from rhododendron (rhododendron ponticum) biomass
Akgül, Mehmet
Korkut, Süleyman
Çamlıbel, Osman
Candan, Zeki
Akbulut, Turgay
rhododendron
MDF
surface roughness
wettability
surface characteristics
Wettability and surface roughness properties of medium density fiberboard (MDF) panels made from Rhododendron biomass were examined in this study. Rhododendron dominates the understory layer of the forests throughout the Black Sea Region in Turkey with substantial biomass potential. This study was conducted to evaluate suitability of Rhododendron fiber for MDF production. For the experiments, rhododendron and commercially-manufactured-chip (Pinus sylvestris L. and Quercus robur L.) with 11% moisture content were used. The mixing ratios of rhododendron with commercially-manufactured-chip were 100:0, 75:25, 50:50, 25:75 and 0:100 %, respectively. Commercial urea formaldehyde (UF) adhesive was used as a binder. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were taken perpendicularly to the fiber. There was a significant diff erence (p=0.05) between surface roughness parameters (Ra, Rz, Rq, and Ry). Th e results obtained in this study revealed that all the panels have met the general purpose-use requirements of European Norm (EN). It was found that panels made with a 25/75 ratio of rhododendron to commercially-manufactured-chip had a significantly lower contact angle (88.14o) than panels made with a 100/0 ratio (117.91o). Surface roughness measurements are based on four roughness parameters, average roughness (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum peak-to-valley height (Ry) were considered to evaluate the surface characteristics of the panels and supported the above findings as the panels made with a 25/75 ratio had a slightly rougher surface with average values of 2.929 μm (Ra). From the tests performed, we conclude that increasing the rhododendron mixing portion increased surface roughness and decreased wettability. Based on these results, rhododendron biomass could be an alternative raw material for MDF manufacturing.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1235
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 185-194
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 185-194
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1235/1186
Derechos de autor 2015 Mehmet Akgül, Süleyman Korkut, Osman Çamlıbel, Zeki Candan, Turgay Akbulut
oai:ojs.revistas.ubiobio.cl:article/1236
2017-09-20T17:32:19Z
MCT:art.
driver
Effect of bark stripping on the electrical impedance of quercus suber leaves
Hakam, Abdelillah
Magne Takam, Mariange
Chokairi, Mustapha
Alami Chantoufi, Noureddine
Hamoutahra, Zeinedine
El Alami, Abdelaziz
Famiri, Abderrahim
Ziani, Mohsine
Gril, Joseph
quercus suber
electrical impedance
equivalent circuit
single DCE
leaves
bark-stripping
bark-stripping coefficient
This study examined the effect of bark stripping on the electrical impedance parameters of cork oak young leaves between 40Hz and 100 kHz. This was a new application of the electrical impedances spectroscopy (EIS) in plant science. Various stripping coefficients (CD) were applied on the trees. Bark stripping is expected to affect water metabolism of leaves and therefore changes in the EIS parameters are expected as well. Single-DCE (ZARC) model was used as equivalent circuit for leaves. Several electrophysiological parameters of this model were compared with moisture content (MC) of the leaves. Intracellular resistance (Ri), extracellular resistance (Re) and relaxation time (τ) of the leaves increased during 14 days aft er stripping while the distributed coefficient (Ψ) and MC decreased. Signifi cant correlation between EIS parameters, MC and trees treatments were found.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1236
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 195-208
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 195-208
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1236/1187
Derechos de autor 2015 Abdelillah Hakam, Mariange Magne Takam, Mustapha Chokairi, Noureddine Alami Chantoufi, Zeinedine Hamoutahra, Abdelaziz El Alami, Abderrahim Famiri, Mohsine Ziani, Joseph Gril
oai:ojs.revistas.ubiobio.cl:article/1237
2017-09-20T17:32:19Z
MCT:art.
driver
Efecto de la densidad de plantación inicial en el módulo de elasticidad dinámico de árboles en pie y trozas de una plantación de Pino radiata de 28 años, en la zona de arenales, Chile
Soto, L.
Valenzuela, L.
Lasserre, J.P.
dynamic modulus of elasticity
initial planting density
pinus radiata
módulo de elasticidad dinámico
densidad de plantación inicial
En un ensayo de densidad de plantación inicial (DPI), se evaluó el efecto de cuatro tratamientos (2500, 1667, 833 y 625 árb·ha-1) en el módulo de elasticidad dinámico (MOEd) de Pinus radiata D. Don, de 28 años, creciendo sobre un suelo de la serie Arenales, en la Región del Biobío, Chile.El MOEd se determinó con tecnología acústica utilizando el método de tiempo de vuelo (Tv) para árboles en pie y posterior a su volteo se usó el método de resonancia (Res) para dos trozas de 5 m de longitud (primera y segunda troza), extraídas desde la base y a lo largo del fuste de cada árbol.La DPI no afectó significativamente el MOEd de los tratamientos más densos (2500, 1667 y 833 árb·ha-1), tanto para árboles en pie, como para las dos trozas. En cambio, el tratamiento menos denso (625 árb·ha-1) presentó el mayor MOEd, significativamente diferente en árboles en pie y la primera troza, y similar entre la primera y segunda troza. AbstractThe influence of initial planting density (DPI) on the dynamic modulus of elasticity (MOEd examinated at a 28 years old Pinus radiata D. Don spacing experiment with four treatments (2500, 1667, 833 and 625 stem·ha-1) growing on sandy soil, in the Biobío Region, Chile.The MOEd acoustic technology was determined using the method of time of flying (Tv) for standing trees and the resonance method (Res) for two logs of 5 m long, extracted from the tree base to the top of each tree.MOEd was not significantly influenced by DPI in high initial stocking treatments (2500, 1667 and 833 stem·ha-1), both standing trees and logs level. In contrast, the lowest initial stocking treatment (625 stem·ha-1) had the highest MOEd, significantly different in standing trees and the first the log, and similar between the first and second log.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1237
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 209-224
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 209-224
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1237/1188
Derechos de autor 2015 L. Soto, L. Valenzuela, J.P. Lasserre
oai:ojs.revistas.ubiobio.cl:article/1238
2017-09-20T17:32:19Z
MCT:art.
driver
Fracturas en madera de Eucalyptus nitens: Efecto de las propiedades mecánicas a nivel ultraestructural y de la anatomía celular
Valenzuela, Paulina
Bustos, Cecilia
Pierre Lasserre, Jean
Gacitúa, William
eucalyptus nitens
nanoindentations
nanomechanical properties
wood anatomy
wood cell fracture
nanoindentaciones
propiedades nanomecánicas
anatomía de la madera
fracturas de la madera
Se realizó un estudio para indagar en las causas y posibles factores que originan la fractura en la estructura de la madera de Eucalyptus nitens. Para esto se examinó el comportamiento nanomecánico de la lamela media (LM), de las capas S1 y S2 de la pared celular. También se determinaron el número, área y diámetro de los vasos que están asociados a niveles de agrietamiento extremos (alto y bajo). Se estudiaron dos familias de Eucalyptus nitens procedentes de dos sitios de la 8va Región de Chile. Mediante el cálculo y análisis de la razón de ductilidad (E/H), se determinó que la LM es más quebradiza que la capa S1, y ésta a su vez más quebradiza que la capa S2; existiendo diferencias significativas en la ductilidad de estas capas. La LM y capa S1 se comportan como materiales resilientes, no así la capa S2. La diferencia en el módulo de resiliencia se relacionó con las mayores tensiones de corte que se presentaron en las interfaces LM/S2 y S1/S2. La caracterización de los vasos mostró que la familia con nivel de agrietamiento mayor, tiene mayor frecuencia, área y diámetro de vasos, los cuales contribuyen a la concentración de esfuerzos en la estructura celular de la madera. Los resultados evidenciaron que la capa S1 fue más débil que la capa S2 y LM dada la diferencia en resistencia entre ellas y que complementado con las tensiones internas que se generan en el proceso de crecimiento del árbol se producen las microgrietas. AbstractThis study was conducted to investigate the causes and posibles factors related to fractures in the cellular structure in Eucalyptus nitens. Nanomechanical cell wall properties at the middle lamella level (ML), S1 and S2 layers were evaluated. In addition, the area, and diameter of vessels were measured. These parameters were associated with extreme levels of cracking (high and low) in two Eucalyptus nitens families. e samples were taked from two sites of the 8th Region of Chile. The analysis of the ductility ratio (E/H) demonstrated that the ML is more brittle than the S1 layer; and the S1 is more brittle than S2 layer. The ML and S1 layer behave like resilient materials, but not the S2 layer. The diffrence in the modulus of resilience was related to higher shear stresses at the ML/S2 and at S1/S2 interfaces. The characterization of the vessels showed that the families with greater level of cracking have also lower frequency and greater area and diameter of vessels e S1 layer was weaker tan S2 layer and LM due to their difference in resistance between them and combined with the internal stresses might propagate the microcracks.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1238
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 225-238
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 225-238
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1238/1189
Derechos de autor 2015 Paulina Valenzuela, Cecilia Bustos, Jean Pierre Lasserre, William Gacitúa
oai:ojs.revistas.ubiobio.cl:article/1239
2017-09-20T17:32:19Z
MCT:art.
driver
Effect of thermal rectification on colors of Eucalyptus saligna and Pinus caribaea woods
Sodero Martins Pincell, Ana Lúcia Piedade
de Moura, Luiz Fernando
Brito, José Otávio
eucalyptus
pinus
thermal treatment
color
Eucalyptus saligna and Pinus caribaea var. hondurensis woods underwent a variety of thermal rectifi cation treatments (from 120ºC to 180ºC) to evaluate the effect of heating on their colorimetric properties. The following color parameters were measured: lightness (L), a* coordinate (green-red coordinate), b* coordinate (blue-yellow coordinate), saturation (C), and tonality angle (H). This study demonstrates that thermal rectifi cation can be regarded as a tool for adding value to wood through color modifi cation by heating. Results also suggest that thermal rectifi cation might be a tool for homogenizing wood tonality and reddish color between species. Both tested species have shown very distinct colorimetric behaviors as a function of thermal treatments. The conifer was more resistant to thermal darkening than the hardwood while exposed to temperatures below 160oC. The green-red coordinate (a*) and the tonality angle (H) tended to be homogenized for both species, as they decreased in eucalyptus, and increased in pinus, as a function of heating. The effect of wood heating on the blue-yellow coordinate (b*), saturation (C), and tonality angle (H) was likely to be opposite between both tested species.
Universidad del Bio-Bio
2014-12-24
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
application/pdf
https://revistas.ubiobio.cl/index.php/MCT/article/view/1239
Maderas-Cienc Tecnol; Vol. 14 No. 2 (2012); 239-248
Maderas-Cienc Tecnol; Vol. 14 Núm. 2 (2012); 239-248
0718-221X
0717-3644
spa
https://revistas.ubiobio.cl/index.php/MCT/article/view/1239/1190
Derechos de autor 2015 Ana Lúcia Piedade Sodero Martins Pincell, Luiz Fernando de Moura, José Otávio Brito
2a0f555db225b96962ac4b12a8dc2059