Maderas. Ciencia y Tecnología http://revistas.ubiobio.cl/index.php/MCT <p>Maderas: Ciencia y Tecnología es una revista internacional de investigación científica, que comunica el conocimiento generado en Chile o en el exterior por la investigación científica y tecnológica en el ámbito de la Ciencia y la Tecnología de la Madera.</p> <table style="margin-top: -250px; width: auto;"> <tbody> <tr> <td style="width: 30%;"><strong><span style="color: #ffffff; text-align: center;"> Vol 20, No 1 (2018)<br></span></strong><br> <img style="width: 300px;" src="/public/site/images/visepul/cover_3d_20(1).jpg" alt=""></td> <td style="width: 30%;"> <p><img style="width: 30px;" src="http://revistas.ubiobio.cl/public/site/images/visepul/pdf_icon_copy6.png" alt=""> <a href="http://revistas.ubiobio.cl/index.php/MCT/issue/view/259">Full Text PDF</a><br> <img style="width: 30px;" src="http://revistas.ubiobio.cl/public/site/images/visepul/e-book_full1.png" alt=""> e-book version<br> <a href="http://revistas.ubiobio.cl/revistamadera/e-book/18.2-2016/mobile/"><img style="width: 30px;" src="http://revistas.ubiobio.cl/public/site/images/visepul/mobile2.png" alt=""></a> mobile version</p> </td> <td style="width: 30%;"> <p>Editor-in-Chief: <a href="mailto:ananias@ubiobio.cl" target="_self">Rubén A. Ananias</a><span id="result_box" class="short_text" lang="en"><br>Technical Editor</span>: <a href="mailto:lsalvo@ubiobio.cl">Linette Salvo S.<br></a>Digital Manager: <a href="mailto:%20vsepulveda@ubiobio.cl">Victor Sepúlveda V.</a><br>E-mail :<a href="mailto:remaderal@ubiobio.cl">remadera@ubiobio.cl</a><br>E-mail :<a href="mailto:remadera.journal@gmail.com">remadera.journal@gmail.com</a><br><br>2016 Journal Impact Factors:<br> 2-years: 1.1<br>5-years: 1.11<br> Frequency: 4 issues by year.<br>ISSN 0718-221X online version.<br>ISSN 0717-3644 printed version.</p> </td> </tr> </tbody> </table> en-US ananias@ubiobio.cl (Ruben A. Ananias.) vsepulveda@ubiobio.cl (Victor Sepulveda Villarroel) Sat, 03 Mar 2018 00:00:00 +0000 OJS 3.1.0.1 http://blogs.law.harvard.edu/tech/rss 60 Chemical characterization and FTIR spectroscopy of thermally compressed eucalyptus wood panels http://revistas.ubiobio.cl/index.php/MCT/article/view/3150 <p>In this study, the change in the chemical properties of the thermally modified eucalyptus (<em>Eucalyptus camaldulensis</em>) wood boards were examined by wet chemical analysis and FTIR spectroscopy. The eucalyptus wood boards were modified with a laboratory type hot-press for four different groups at press pressures of 2 or 4 MPa and temperatures of 150°C or 180°C and compared to untreated control. After this, hot water, 1% NaOH, ethanol-cyclohexane, ethanol, and methanol-water solubility values were determined for the treated samples. In addition, the content of klason lignin, acid soluble lignin, holocellulose, and α-cellulose were investigated. The solubility values (except for the ethanol solubility) increased in the modified wood when compared to the untreated control. A decrease in the content of acid soluble lignin, holocellulose and α-cellulose was observed while the content of klason lignin in the modified wood was increased. According to the FTIR analysis results, significant changes were observed in the spectra of the modified samples. These findings were in agreement with the results of wet chemical analysis.</p> Oktay Gonultas, Zeki Candan ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3150 Sat, 03 Mar 2018 00:00:00 +0000 The wettability and surface free energy of sawn, sliced and sanded european oak wood http://revistas.ubiobio.cl/index.php/MCT/article/view/3151 <p>The main objective of this work was to evaluate the effects of two machining processes on European oak wood surface characteristics. The relationships between wettability, free surface energy and machining methods were studied. Sawing and slicing, with or without sanding, were used to prepare surfaces prior to testing whether they produce surfaces with different characteristics. For the wood surfaces machined by slicing and sawing, there was a significant difference in contact angle measurements. This indicates that the influence of machining processes such as slicing and sawing on contact angle value is remarkable. Sanded surfaces showed good wettability and high process roughness.</p> Agnieszka Jankowska, Marcin Zbieć, Paweł Kozakiewicz, Grzegorz Koczan, Sylwia Oleńska, Piotr Beer ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3151 Sat, 03 Mar 2018 00:00:00 +0000 Durability of wood treated with aatmos and caffeine – towards the long-term carbon storage http://revistas.ubiobio.cl/index.php/MCT/article/view/3152 <p>Increasing emission of greenhouse gases, mainly carbon dioxide, and reduced capacity of carbon sequestration due to excessive deforestation are the dominant reasons for the observed climate warming. Wood and wood products are inherent parts of the overall carbon “jigsaw puzzle”. Wood products require much lower process energy and result in lower carbon emission than non-wood products. Therefore, the prolonging lifespan of wood products seems to be a good economical and environmentally friendly solution.</p> <p>The aim of the research was to determine the effectiveness of wood treatment with aminosilane, caffeine and the mixture thereof to enhance its durability. Thereby, their potential impact on the environment was intended to be checked by allowing for carbon storage in treated wood for a longer period of time. Pine wood samples were vacuum-treated with three formulations: aminosilane, alkaloid and the mixture thereof. Resistance of wood against brown-rot fungus was assessed. Carbon content and carbon emission from wood samples were determined.</p> <p>The best results in wood protection against biodegradation and the highest carbon sequestration effectiveness were achieved for the two-component mixture. Interactions between these chemicals and wood prevented their leachability. This resulted in increased durability of the treated wood samples, sequestering carbon for a longer period of time and limiting its emission from wood to the atmosphere while exposed outside.</p> Magdalena Broda, Bartłomiej Mazela, Marcin Frankowski ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3152 Sat, 03 Mar 2018 00:00:00 +0000 Influence of technical characteristics on the rolling shear properties of cross laminated timber by modified planar shear tests http://revistas.ubiobio.cl/index.php/MCT/article/view/3154 <p class="MDPI17abstract" style="line-height: 150%;"><span style="font-size: 12.0pt; line-height: 150%; font-family: 'Times New Roman','serif';" lang="EN-US">Rolling shear properties of cross laminated timber are important mechanical properties </span><span style="font-size: 12.0pt; line-height: 150%; font-family: 'Times New Roman','serif'; color: windowtext;" lang="EN-US">for its structural application. To evaluate the influence of technical characteristics such as </span><span style="font-size: 12.0pt; line-height: 150%; font-family: 'Times New Roman','serif';" lang="EN-US">edge-gluing and gap size in the cross layers, on the measurement of rolling shear modulus and strength of cross laminated timber, three-layer spruce-pine-fire cross laminated timber shear block specimens with and without edge-gluing, with gaps of 2 mm, 4 mm and 6 mm, were tested by a modified planar shear test method. The mean values of rolling shear strength and modulus of No. 2 visual grade spruce-pine-fire cross laminated timber were 1.32 MPa and 111 MPa with coefficients of variance of 20% and </span><span style="font-size: 12.0pt; line-height: 150%; font-family: 'Times New Roman','serif'; color: windowtext;" lang="EN-US">28%, respectively, regardless of technical characteristics. The characteristic rolling shear </span><span style="font-size: 12.0pt; line-height: 150%; font-family: 'Times New Roman','serif';" lang="EN-US">strength of all groups of three-layer cross laminated timber specimens was determined to be 0.88 MPa. The results indicated that the rolling shear strength and modulus values used in current design practice of spruce-pine-fire cross laminated timber were conservative. It was found that edge-gluing and gap size had a significant influence on measuring rolling shear strength rather than apparent rolling shear modulus by the modified planar shear test method. With the gap size larger than 2 mm, its influence on measuring rolling shear strength became negligible. The three major initial failure modes identified for the cross layer regardless of technical characteristics were rolling shear failure along the growth ring, tension perpendicular to grain failure in wood pith and tension perpendicular to grain failure along the wood ray.</span></p> Zhiqiang Wang, Jianhui Zhou, Weiqun Dong, Yue Yao, Meng Gong ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3154 Sat, 03 Mar 2018 00:00:00 +0000 Fourier transform infrared spectroscopy in treated woods deteriorated by a white rot fungus http://revistas.ubiobio.cl/index.php/MCT/article/view/3157 <p>This study aimed to analyze chemical changes by Fourier Transform Infrared Spectroscopy of <em>Eucalyptus dunnii</em> and <em>Pinus elliottii</em> treated woods subjected to an accelerated decay test with the white rot fungus <em>Ganoderma applanatum</em>. The wood test specimens (2.5x2.5x0.9 cm) were impregnated with preservative solutions of chromated copper borate and synthetic pyrethroids and carbamates with 6% concentration by a vaccum-pressure process. After a decay test of 16 weeks, the chemical changes of the treated and untreated wood samples were evaluated by Fourier Transform Infrared Spectroscopy. It was observed that the rot fungus attack caused a variation in the intensity and a displacement of spectrum peaks, indicating a change to the woods’ chemical composition after fungal exposure. The lignin / carbohydrate ratio indicated that the fungus had no preference for a specific cell wall component, pointing to a simultaneous deterioration of cellulose, hemicellulose and lignin in the treated and untreated woods. Finally, the Fourier Transform Infrared Spectroscopy technique, together with the lignin / carbohydrate ratio analysis, proved efficient in the study of the variation of the wood chemical modifications deteriorated by rot fungi.</p> Ezequiel Gallio, Paula Zanatta, Débora Duarte Ribes, Marília Lazarotto, Darci Alberto Gatto, Rafael Beltrame ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3157 Sat, 03 Mar 2018 00:00:00 +0000 Natural durability assessment of thermo-modified young wood of eucalyptus http://revistas.ubiobio.cl/index.php/MCT/article/view/3159 <p>This study focuses on the effect on wood strength and natural durability of <em>Eucalyptus globulus</em> and <em>Eucalyptus botryoides</em> when subjected to heat treatments with low energy consumption. The objective was to improve the wood durability, without negatively impacting the strength properties. Six-year-old trees from <em>Eucalyptus</em><em> globulus</em> and <em>Eucalyptus</em><em> botryoides</em> were used.</p> <p>The samples were heat treated for 4 h conditioned to very low oxygen availability. A field test for assessing the resistance to termites and fungal degradation was conducted according to EN 252:1989/AC1:1989 Inspections were made every six months for 3 years. All the samples of <em>Eucalyptus globulus</em> showed signs of termite and microorganisms attack, most showing extensive galleries. <em>Eucalyptus botryoides</em> wood showed no sign of termite attack and only few traces of microrganisms presence. The wood bending strength was smaller upon thermal treatment for both species, decreasing 3.8% and 4.8% for <em>Eucalyptus globulus </em>and <em>Eucalyptus botryoides</em>, respectively. Overall the results are promising regarding some common utilizations, mainly floor coverings, decks, doors and door and window frames, fences (only for <em>Eucalyptus botryoides</em>), decorative arbors and pergolas (only for <em>Eucalyptus botryoides</em>), but excluding structural beams for building roofs or bridges due to the fragility of the wood treated thermally towards impacts.</p> Sofia Knapic, Joana Santos, José Santos, Helena Pereira ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3159 Sat, 03 Mar 2018 00:00:00 +0000 Effect of microwave heating on ph and termite resistance of Pinus roxburghii wood http://revistas.ubiobio.cl/index.php/MCT/article/view/3160 <p>This study investigated the effect of microwave treatment on wood pH and termite resistance. <em>Pinus roxburghii</em> heartwood was exposed to four different microwave intensities at 2450 MHz frequency for 5 minutes. Preservative impregnation, pH variation and termite resistance of microwave-treated and control specimens were studied. Wood pH decreased from 4.6 (C1) to 3.9 (T4) and preservative uptake increased (i.e., 10.41 to 21.61 kgm<sup>-3</sup>) with increasing microwave treatment intensities. However, microwave treatment had little effect on termite resistance.</p> Pawan Kumar Poonia, Sadhna Tripathi ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3160 Sat, 03 Mar 2018 00:00:00 +0000 Distinctive delignification with consecutive application of Geobacillus sp. 71 xylanase and Rhodococcus jostii rha1 lignin peroxidase http://revistas.ubiobio.cl/index.php/MCT/article/view/3167 <p>In present study, single and consecutive applications of xylanase and lignin peroxidase were performed in an XOQP TCF sequence to bleach pine and eucalypts kraft pulp. The consecutive use of <em>Geobacillus sp.</em> strain 71 xylanase and <em>Rhodococcus jostii</em> RHA1 lignin peroxidase was more effective than the single uses. XyzGeo71 treatment (X) indicates a 9.76% and 28.52% reduction in kappa number for pine and eucalypts kraft pulps, respectively. LiPRHA1 treatment (X) showed a 7.88% and 20.9% reduction a in kappa number for pine and eucalypts kraft pulps, respectively. The consecutive treatment of XyzGeo71 and LiPRHA1&nbsp; (X), however, indicated a 13.67% and 37.2% reduction in kappa number for pine and eucalypts kraft pulps, respectively. The results showed that delignification with the consecutive xylanase and lignin peroxidase treatment was very significant.</p> Aysegul Ozer, Sabriye Canakci, Gozde Gocmen, Ilhan Deniz, Huseyin Kirci, Onur Tolga Okan, Ali Osman belduz ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3167 Sat, 03 Mar 2018 00:00:00 +0000 Analysis of biological pretreatment of rapeseed straw with white rot fungi for enzymatic hydrolysis http://revistas.ubiobio.cl/index.php/MCT/article/view/3168 <p>The effect of biological pretreatment on the rapeseed straw was evaluated by solid-state cultivation of white rot fungi <em>Phanerochaete chrysosporium</em>. <em>P.chrysosporium </em>degraded the lignin during the pretreatment, with enzymatic hydrolysis ratios increasing in the pretreated straw (3-fold after a 15 day pretreatment). The samples were identified by XRD, FTIR and SEM. X-ray analysis showed that pretreated samples had higher crystallinity than untreated samples (39.47% for a pretreated sample compared to 33.17% for untreated samples) and FTIR spectroscopy demonstrated that the content of lignocellulose also decreased during the biological pretreatment process. The surface characterization study showed morphological changes in pretreated samples. Moreover, the biological pretreatment slowed a plunge in hydrolysis rate during enzymatic hydrolysis.</p> Rasool Ghasemzadeh, Mohammad T. Hamed Mosavian, Afzal Karimi ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3168 Sat, 03 Mar 2018 00:00:00 +0000 Using artificial neural networks in estimating wood resistance http://revistas.ubiobio.cl/index.php/MCT/article/view/3203 <p>The purpose of this research was to evaluate the potential of Artificial Neural Networks in estimating the properties of wood resistance. In order to do so, a hybrid of eucalyptus (<em>Eucalyptus urograndis</em>) planted in the Northern Region of the State of Mato Grosso was selected and ten trees were collected. Then, four samples of each tree were removed, totaling 40 samples, which were later subjected to non-destructive testing of apparent density, ultrasonic wave propagation velocity, dynamic modulus of elasticity obtained by ultrasound, and Janka hardness. These properties were used as estimators of resistance and compressive strength parallel to fibers, and hardness. Multilayer <em>Perceptron</em> networks were also employed, training 100 of them for each of the evaluated parameters. The obtained results indicated that the use of Artificial Neural Networks is an efficient tool for predicting wood resistance.</p> Eder Pereira Miguel, Rafael Rodolfo de Melo, Laércio Serenini Junior, Cláudio Henrique Soares Del Menezzi ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3203 Sat, 03 Mar 2018 00:00:00 +0000 Prediction of microfibril angle for Eucalyptus microcorys wood by fiber length and basic density http://revistas.ubiobio.cl/index.php/MCT/article/view/3204 <p>Aim of the study was to estimate the influence of the fiber length and basic density on microfibril angle of <em>Eucalyptus microcorys</em> wood. The study area was in an experimental planting at the Universidade Federal de Lavras, Minas Gerais State, Brazil. Three 37 year-old <em>Eucalyptus microcorys</em> trees were used, from whose stems six centimeter-thick discs were removed, cut at a high of three meters. The disks were sanded and planed to highlight the growth rings. Specimens were taken every 1.5 cm across the radius from pith to bark for determining microfibril angle, fiber length and wood basic density. The microfibril angles were determined by use of polarized light microscopy, while the fiber morphology and basic density were determined by usual methods. The averages found for microfibril angle (12.6°), fiber length (968 µm) and basic density (480 kg.m<sup>-3</sup>) are, in general, within the range of values reported for these characteristics of wood. The microfibril angle showed accentuated reduction of the average values in the pith-bark direction. The fiber length and basic density showed the opposite behavior. We observed that the density and fiber length may be used as an microfibril angle predictor, accounting for 96% and 79% of its variation, respectively.</p> Luiz Eduardo de Lima Melo, Selma Lopes Goulart, Bárbara Maria Ribeiro Guimarães, Rosalvo Maciel Guimarães Neto, Caroline Junqueira Sartori, José Tarcísio Lima ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3204 Sat, 03 Mar 2018 00:00:00 +0000 Influence of coupling agents on rheological, thermal expansion and morphological properties of recycled poypropylene wood flour composites http://revistas.ubiobio.cl/index.php/MCT/article/view/3217 <p>In this work, thermal expansion and morphological properties of recycled polypropylene wood flour composites were evaluated in order to verify the effect caused by the usage of a natural oil as coupling agent. The natural oil used as coupling agent was octanoic acid (C8), maleic anhydride grafted polypropylene (MAPP), widely used in industry but from non-renewable source, was also used for comparison. Composites were obtained by twin screw extrusion and injection molded. The results showed that the addition of octanoic acid and maleic anhydride grafted polypropylene reduced the coefficient of thermal expansion of the composites. The dependence of melt viscosity obeyed the Arrhenius-Eyring expression, and the activation energy values for composite viscous flow were higher than matrix. The composite morphology revels that octanoic acid promotes strong interfacial adhesion between filler and matrix, similar to that observed when maleic anhydride grafted polypropylene were used. Octanoic acid showed similar results when compared with maleic anhydride grafted polypropylene in all properties evaluated, indicating that can be used as an alternative instead of use coupling agent from non-renewable sources.&nbsp; &nbsp;&nbsp;&nbsp;</p> Matheus Poletto ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3217 Sat, 03 Mar 2018 00:00:00 +0000 Influence of relative humidity and temperature on cultivation of pleurotus species http://revistas.ubiobio.cl/index.php/MCT/article/view/3218 <p>Fungi exhibit different behavior under different conditions and react to light, temperature, moisture content etc. The objective of &nbsp;this study was to evaluate the degradation capability of three common white rot fungi, namely: <em>Pleurotus</em> <em>ostreatus</em>, <em>P. pulmonarius</em>, and <em>Lentinus</em> <em>sajor-caju</em>. The respective fungi were cultivated on rice straw under three different environmental conditions for 90 days. The fungi were collected, pure cultured, DNA extracted, and sequenced by ITS regions. The highest consumption of substrate occurred under the Cellar (dark) exposure condition with <em>P. pulmonarius </em>producing the least mass loss. The least amount of degradation occurred under the Air (daylight) condition for all of the fungi with the exception of <em>P. pulmonarius</em>. Exposure to light promoted the formation of fruiting bodies.</p> Hamed Aghajani, Ehsan Bari, Mohsen Bahmani, Miha Humar, Mohammad Ali Tajick Ghanbary, Darrel D. Nicholas, Emran Zahedian ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3218 Sat, 03 Mar 2018 00:00:00 +0000 Evaluation of palm fiber components an alternative biomass wastes for medium density fiberboard manufacturing http://revistas.ubiobio.cl/index.php/MCT/article/view/3220 <p>This work deals with assessing the date palm component wastes as alternative lignocellulosic material for production of Medium density fiberboards, in order to establish economic and balance between production/consumer ratio at different provinces rather than Upper Egypt. Palm leafs and palm frond was used as Medium density fiberboards precursors. Different urea formaldehyde levels (10-14%/fiber) and pressing pressure (25-35 bar) were applied in this evaluation. The acceptable interaction of palm fibers component with urea formaldehyde was optimized by characterizing its differential scanning calorimetry and thermogravimetric analysis, in comparison with commercial used sugarcane bagasse fibers. The promising Medium density fiberboards Panel is obtained from palm frond fibers and its mechanical and water resistance properties fulfill the ANSI standard for high grade Medium density fiberboards wood products, especially on applying urea formaldehyde level 12-14%, and pressing pressure, 35 bar. It is interesting to note that, applying higher pressing pressure together with 12% urea formaldehyde level provided palm frond-based Medium density fiberboards with static bending properties, higher than commercial bagasse-based Medium density fiberboards. The insignificant effect of pressing pressure was noticed on water swelling property and free-HCHO of Medium density fiberboards panels. &nbsp;Where, both type of fibers have the same water swelling property (reached ~ 10%), and free-HCHO (~ 27 mg/100g board).</p> Abdel-Baset A. Adam, Altaf H. Basta, Houssni El-Saied ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3220 Sat, 03 Mar 2018 00:00:00 +0000 Determinación inversa de la conductividad térmica en madera de Pinus radiata http://revistas.ubiobio.cl/index.php/MCT/article/view/3221 <p>Laboratory scale experiments are performed in order to characterize the artificial wood drying of <em>Pinus radiata</em> at conventional temperatures and accelerated temperatures. The experimental data allow to determine the wood thermal conductivity through inverse methodology. The comparative analysis shows that the implementation of the developed inverse methodology is consistent with&nbsp; information available in the specialized literature; which means increased thermal conductivities with increased humidity and temperature, whose values oscillate between 0,34 and 0,56 (W/m K) to moisture variations between 22% and 64%; and temperatures between 70°C and 90°C, respectively.</p> Luis Acuña-Alegria, Carlos Salinas-Lira, Víctor Sepulveda-Villarroel, Diego Vasco-Calle, Rubén A. Ananías ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3221 Sat, 03 Mar 2018 00:00:00 +0000 Risk assessment of mould growth on spruce wood during transport in an intermodal container http://revistas.ubiobio.cl/index.php/MCT/article/view/3222 <p>Microclimatic conditions (relative humidity and temperature) were monitored in a shipment of Norway spruce (<em>Picea abies</em>) wood inside an intermodal container on its 66-day transport from Slovenia to Japan. In parallel, the susceptibility of Norway spruce wood to moulding fungi was determined and a dynamic vapour sorption analysis was performed. Considerable moulding developed on specimens that were exposed to a climate with relative humidity above 93%. The results of the laboratory assessment correlated with the observations of mould development in the container. The relative humidity in the container was below 93%, so there was no mould growth on the transported Norway spruce wood.</p> Davor Kržišnik, Boštjan Lesar, Nejc Thaler, Samo Grbec, Miha Humar ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3222 Sat, 03 Mar 2018 00:00:00 +0000 Calentamiento por radiofrecuencia para esterilizar pinus radiata como material para embalajes. Parte 1: Tiempo total de tratamiento http://revistas.ubiobio.cl/index.php/MCT/article/view/3224 <p>In this work the total heating time was studied using radio frequency to sterilize wood packaging material of <em>Pinus radiata</em>, through the conditions 56 ° C and 60 ° C for 30 and 1 minutes respectively, according to international phytosanitary norms. The experimental tests were carried out in a laboratory radiofrequency equipment of 3 m<sup>3</sup> capacity. The heating time was determined and prediction models were developed, depending on the thickness, plaque separation and wood loading volume, with confidence levels above 90%. The results showed that the total time of radiofrequency sterilization was greater in the surface of the pile and were statistically similar under both treatment conditions.</p> Héctor Esquivel-Reyes, Víctor Sepúlveda-Villarroel, José Torres-Mella, Linette Salvo-Sepúlveda, Carlos Salinas-Lira, Rubén A. Ananias ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3224 Sat, 03 Mar 2018 00:00:00 +0000 Microwave-assisted solvothermal: An efficient and new method to obtain hydrophobic wood surfaces http://revistas.ubiobio.cl/index.php/MCT/article/view/3225 <p>The objective of this work was to form a hydrophobic surface in a highly porous wood by coating and incorporating TiO<sub>2</sub> micro/nano structures through the microwave-assisted solvotermal method, without need any pre- or post-modification of the wood substrate, using low temperatures and short times. The behavior and morphology of the TiO<sub>2</sub>-treated surfaces was characterized using scanning electron microscopy (SEM), while the elemental composition was determined via energy-dispersive X-ray spectroscopy&nbsp; and X-ray diffraction analysis. The results indicated that the crystallization of the TiO<sub>2 </sub>anatase phase was efficient and fully coated the wood surface during the solvothermal process. The treated wood contained TiO<sub>2</sub> particles with an average diameter of 200 nm that also allowed to coat an abundant fraction of tracheids cell walls. When investigated through X-ray spectroscopy-mapping, the element titanium&nbsp; appeared abundantly throughout the wood. After TiO<sub>2</sub> growth in wood through the microwave-assisted solvotermal method, a roughness at the micro/nano scales structures was created on the wood surface, originating an increase in the contact angle up to 137°, which characterizes the appearance of a hydrophobic surface.&nbsp; The TiO<sub>2</sub>-treated wood demonstrated 85% of water absorption after 400 hours of immersion, while untreated wood reached 160%, suggesting that the microwave-assisted solvotermal process promotes a delay in the progression of water absorption. This feature can improve the dimensional stability of wood, contributing to the increase of its durability and applications.</p> Paula Zanatta, André Luiz Missio, Marília Lazarotto, Sérgio da Silva Cava, Pedro Lovato Gomes Jardim, Darci Alberto Gatto, Mário Lúcio Moreira ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3225 Sat, 03 Mar 2018 00:00:00 +0000 Potential use of nir and visible spectroscopy to analyze chemical properties of thermally treated wood http://revistas.ubiobio.cl/index.php/MCT/article/view/3228 <p>The modification of wood by thermal treatments produces characteristic changes in its chemical composition and surface color and can improve the structural and esthetic quality. The objective of this paper is to evaluate the potential of near infrared and visible spectroscopy to predict the modifications in chemical composition of <em>Eucalyptys grandis</em> and <em>Pinus taeda</em> after thermal treatment. Near infrared and visible spectra were collected directly on the longitudinal surface of wood samples. The thermally modified wood of both species showed higher content of lignin and extractives than the untreated wood. There was darkening of thermally modified wood, as a result of chemical modification caused by heat. The Near infrared/visible technique identified the groups that were modified by treatment. NIR and visible spectroscopy can be used to predict chemical composition of natural or thermally treated <em>Eucalyptus grandis </em>and <em>Pinus taeda. </em></p> Elaine Cristina Lengowski, Graciela Inês Bolzon de Muñiz, Umberto Klock, Silvana Nisgoski ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3228 Sat, 03 Mar 2018 00:00:00 +0000 Determinantes de la satisfacción laboral en la industria de la madera y el papel: Estudio en españa y hallazgos en otros países http://revistas.ubiobio.cl/index.php/MCT/article/view/3229 <p>This paper is carried out in a workers group of logging, wood and paper industry, which is compared with the whole of the labor market. We select 14 quantitative variables of job-related features. For this purpose, we use data Quality of Labor Life Survey (ECVT) by the Spanish Ministry of Employment and Social Security. The first objective is to find out which variables and groups of variables (or factors) affect job satisfaction in logging, wood and paper industry, comparing these results with the national set. Our methodologies are principal component analysis, cluster analysis and stepwise multiple regression. The second objective is to review similar studies in other countries in order to find some common pattern. The analysis in both groups (logging, wood and paper on the one hand, and the Spanish national set on the other) allows us to find whether determinants are the same or different according to activity. So, in both cases, wage is one of the last factors that explain labor satisfaction, whereas motivation and personal development are on the top position. It is not possible to propose a general and valid theory in all areas from studies in other countries, so that if the context is different, the determinants that affect job satisfaction are also different.</p> María Carmen Sánchez-Sellero, Pedro Sánchez-Sellero ##submission.copyrightStatement## http://revistas.ubiobio.cl/index.php/MCT/article/view/3229 Sat, 03 Mar 2018 00:00:00 +0000