Maderas-Cienc Tecnol 2021-01-01T00:00:00-03:00 Ruben A. Ananias. Open Journal Systems <table> <tbody> <tr> <td style="width: 30%;"><strong><span style="color: #ffffff; text-align: center;"><img src="/public/site/images/visepul/3d-22(3).png"></span></strong></td> <td style="width: 30%;"> <div class="issueCoverDescription"> <div class="description"> <p><img style="width: 30px;" src="" alt=""> <a href="">Full Text PDF</a></p> <p><img style="width: 30px;" src="" alt=""> <a href="">e-book version</a></p> <p><a href=""><img style="width: 30px;" src="" alt=""></a> <a href="">mobile version</a></p> <p><img style="width: 30px;" src="" alt="">&nbsp; <a href=";pid=0718-221X20200050&amp;lng=es&amp;nrm=iso">XML</a></p> </div> </div> </td> <td style="width: 30%;"> <p>Editor-in-Chief: <a href="" target="_self">Rubén A. Ananias</a><span id="result_box" class="short_text" lang="en"><br>Technical Editor</span>: <a href="">Linette Salvo S.<br></a>Digital Manager: <a href="">Victor Sepúlveda V.</a><br>E-mail :<a href=""></a><br>E-mail :<a href=""></a><br><br>2019 Journal Impact Factors:<br> 2-years: 1.2<br>5-years: 1.3<br> Frequency: 4 issues by year.<br>January, April, July, October<br>ISSN 0718-221X online version.<br>ISSN 0717-3644 printed version.</p> </td> </tr> </tbody> </table> Thermal properties of Acacia mangium cross laminated timber and its gluelines bonded with two structural adhesives 2020-08-18T10:57:23-04:00 Norwahyuni Mohd Yusof Paridah Md Tahir Lee Seng Hua Fatimah Athiyah Sabaruddin Redzuan Mohammad Suffian James Mohd Asim Khan Lee Ching Hao Adlin Sabrina Muhammad Roseley <p>The properties of CLT can be affected by the type of adhesives used. The thermal properties of the adhesive that joins the timber together is essential to determine the thermal endurance of the CLT product. In this study, two types of adhesives were used to join the cross laminated timber (CLT) manufactured from <em>Acacia mangium </em>namely phenol resorcinol formaldehyde (PRF) and one component polyurethane (PUR). The thermal properties of the adhesives, <em>A. mangium</em> wood and the gluelines were determined via Thermogravimetric Analysis (TGA) and Dynamic Mechanical Analysis (DMA) tests. The TGA test showed that PRF adhesive had higher degradation temperature at 530 ˚C compared to PUR adhesive at 430 ˚C. Meanwhile, the PRF adhesive as a glueline in CLT also showed better thermal resistance where a higher amount of residue of 20,94 % was recorded at temperature up to 900 ˚C compared to PUR glueline with 18,26 % residue. The integrity of the CLT over temperature were determined via DMA test and the results showed that PRF adhesive as glueline had superior properties, indicating better interfacial bonding with the woods.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## Chemical variation of five natural extracts by non-polar solvent 2020-08-18T10:40:06-04:00 T. A. Prayitno R. Widyorini G. Lukmandaru <p>Chemical compounds of wood preservation from plants vary and are not known specific to the species. Chemical analysis of plants is responsible to ensure active compound in natural extracts wood treatment. There are many sources of natural extracts found in Indonesia that were explored for wood preservatives chemicals. They are bark of acacia and alstonia, leaves of orthosiphon and azardirachta and Dioscorea tubers. The present study was aimed at investigating the variation of the chemical constituent of natural extracts material of wood preservative through GC-MS analysis. Five natural extract sources were acacia bark (<em>Acacia spp</em>.), pulai bark (<em>Alstonia scholaris</em>), kumis kucing leaves (<em>Orthosiphon spp</em>.), mimba leaves (<em>Azardirachta indica</em>), and gadung tubers (<em>Dioscorea spp</em>.). Two non-polar solvents, i.e., n-hexane and petroleum ether were used for five natural source extractions following ASTM soxhlet extraction. The research showed that triterpene and fatty acid derivatives were the major compounds present in five natural extracts. They were lupeol; 7,22-Ergostadienone; Lup-20(29)-en-3-one; Lup-20(29)-en-3-ol, acetate, (3.beta.)-; urs-12-en-3-one; ethanol,2,2-diethoxy-; stigmasta-5,22-dien-3-ol, acetate,(3.beta.)-; 5H-3,5a-Epoxynaphth(2,1-c)oxepin, dodecahydro-3,8,8,11a-tetramethyl-; linoleic acid; naphthalene, 1-methyl-. These compounds have been assigned as the possibly responsible to against termites or fungi.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## Energy gains of eucalyptus by torrefaction process 2020-08-30T14:14:52-04:00 Erica Leonor Romão Rosa Ana Conte <p>The aim of this study was to evaluate the changes in the characteristics of <em>Eucalyptus spp</em><em>. </em>from Paraíba Valley region, Sao Paulo - Brazil after torrification process. Torrification is a thermochemical process that occurs at temperatures lower than the pyrolysis process as a pretreatment to improve biomass characteristics for use as biofuel energy in power generation. An experimental study was carried out in a batch reactor at three temperatures (240 °C, 260 °C and 280 °C) with residence time of 30 and 60 minutes. At the indicated operating conditions by elemental analysis, higher heating value and thermogravimetric analysis were evaluated. Result showed that there was a reduction in the oxygen/carbon (O/C) and hydrogen/carbon (H/C) ratios, causing an increase in the thermal energy quality of torrified wood, about of 28 % and 47 % at temperatures of 260 °C with residence time of 60 minutes and 280 °C with 30 minutes, respectively. A thermogravimetric analysis showed that at 260 °C the hemicellulose was almost completely degraded leaving the fuel in better conditions for combustion or gasification processes.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## Viability of wood decaying fungal mycelium after microwave radiation of bamboo culm 2020-08-31T22:38:40-04:00 Pawan Kumar Poonia Shivaklara R Deepa Manish Kumar Anil Kumar <p>The present study was carried out to evaluate the effects of microwave (MW) radiation on viability of wood decaying fungi. The white rot (<em>Trametes versicolor</em>) and brown rot (<em>Rhodonia placenta</em>) fungi were grown on bamboo culm-samples. The mycelium growths were observed in controlled as well as microwave treated samples. The results showed that the viability of fungi decreased according to the applied MW time. This study proved the ability of the microwaves and exposure time MW3 (180 seconds) to kill the fungal colonies and do not allow for the growth of fungal spores, means the rate of growth of fungal colonies is inversely proportional to time of microwave exposure.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## Nanocellulose-reinforced phenol-formaldehyde resin for plywood panel production 2020-09-07T16:19:43-03:00 Elaine Cristina Lengowski Eraldo Antonio Bonfatti Júnior Rafael Dallo Silvana Nisgoski Jorge Luís Monteiro de Mattos José Guilherme Prata <p>The search for new technologies to improve adhesives and the properties of reconstituted wood panels is constant, and nanotechnology is a tool for this purpose. The aim of this study is investigating the effect of adding nanocellulose in the formulation of the adhesive phenol-formaldehyde on the physico-mechanical properties of <em>Pinus taeda </em>plywood panels. Three ratios of nanofibrillated cellulose (NFC) were added to the adhesive formulation used to produce plywood panels: 0,026 %, 0,038 % or 0,064 %. The panels were tested according to the European standards; apparent density, resistance to parallel and perpendicular flexure and glue line shear strength were determined after 6 hours of boiling and after the boiling cycle for the 1<sup>st </sup>glue line (face) and 2<sup>nd</sup> line (core). The use of NFC in the adhesive caused an increase of viscosity and reduction of the gel time of the adhesive. The apparent density of the panels was not influenced by the addition of NFC, but the properties of parallel bending, perpendicular flexing and glue line shear were sensitive to the addition of NFC. The NR2 treatment (0,038 % NFC) presented the best results in the mechanical tests.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## A new method for determining air permeabilities of wood-based panels 2020-09-07T16:22:46-03:00 Takashi Tanaka <p>In this study, a new apparatus for measuring the air permeability of wood-based panel specimens without using water displacement was developed with the aim of decreasing the influence of variation in atmospheric pressure on permeability measurement. Validation experiments were conducted using plywood, oriented strand board (OSB), particleboard, and medium-density fiberboard (MDF) panels and a control specimen sealed with an epoxy resin. The background (leakage) flow of the apparatus was evaluated based on the experimental results of the control specimen. A methodology for the determination of air permeability based on Darcy’s law for gases and the evaluated background flow rate was proposed. The results of the current study were compared with those obtained in a previous study, indicating that the new method provides valid measurements for wood-based panels with high and low air permeability. No significant influence of variation in atmospheric pressure on the experimental results was observed, suggesting that the proposed method is suitable for a long-term continuous experiment for evaluating a specimen with extremely low permeability.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement## Radial variation in cell morphology of melia azedarach planted in northern vietnam 2020-09-09T11:05:44-03:00 Doan Van Duong Laurence Schimleck Tai Tien Dinh Chu Van Tran <p>The radial variation in cell morphology of ten-year-old <em>Melia azedarach</em> trees planted in northern Vietnam was experimentally investigated. The earlywood fiber lumen diameter and latewood fiber lumen diameter were almost unchanged from pith to 6th ring before significantly decreasing and remaining constant from 7th ring outwards. In contrast, fiber cell wall thickness in both earlywood and latewood increased from pith to 7th ring before becoming stable towards the bark. The maturation age of earlywood vessel lumen diameter estimated by segmented regression analysis indicated that wood of the <em>Melia azedarach </em>could be classified into core wood and outer wood, and the boundary between core and outer wood may be located at 7th ring from pith. This should be taken into account in wood processing using <em>M. azedarach</em> grown in northern Vietnam.</p> 2021-01-01T00:00:00-03:00 ##submission.copyrightStatement##