WorldWideScience

Sample records for wood property traits

  1. Development and Validation of Marker-Aided Selection Methods for Wood Property Traits in Loblolly Pine and Hybrid Poplar; FINAL

    International Nuclear Information System (INIS)

    Tuskan, G.A.

    2001-01-01

    Wood properties influence pulp and paper quality. Certainly, overall pulp yields are directly related to the cellulose content, changes in hemicellulose content are associated with changes in pulp cohesiveness, and pulping efficiency is related to lignin content. Despite the importance of wood properties on product quality, little progress has been made in improving such traits because current methods of assessing wood and fiber characteristics are time-consuming, expensive, and often imprecise. Genetic improvement of wood and fiber properties has been further hampered by the large size of trees, delayed reproductive maturity and long harvest cycles. Recent developments in molecular genetics will help overcome the physical, economic and biological constraints in assessing and improving wood properties. Genetic maps consisting of numerous molecular markers are now available for loblolly pine and hybrid poplar. Such markers/maps may be used as part of a marker-aided selection and breeding effort or to expedite the isolation and characterization of genes and/or promoters that directly control wood properties. The objectives of this project are: (1) to apply new and rapid analytical techniques for assessing component wood properties to segregating F(sub 2) progeny populations of loblolly pine and hybrid poplar, (2) to map quantitative trait loci and identify molecular markers associated with wood properties in each of the above species and (3) to validate marker-aided selection methods for wood properties in loblolly pine and hybrid poplar

  2. Development and Validation of Marker-Aided Selection Methods for Wood Property Traits in Loblolly Pine and Hybrid Poplar

    Energy Technology Data Exchange (ETDEWEB)

    Tuskan, G.A.

    2001-06-20

    Wood properties influence pulp and paper quality. Certainly, overall pulp yields are directly related to the cellulose content, changes in hemicellulose content are associated with changes in pulp cohesiveness, and pulping efficiency is related to lignin content. Despite the importance of wood properties on product quality, little progress has been made in improving such traits because current methods of assessing wood and fiber characteristics are time-consuming, expensive, and often imprecise. Genetic improvement of wood and fiber properties has been further hampered by the large size of trees, delayed reproductive maturity and long harvest cycles. Recent developments in molecular genetics will help overcome the physical, economic and biological constraints in assessing and improving wood properties. Genetic maps consisting of numerous molecular markers are now available for loblolly pine and hybrid poplar. Such markers/maps may be used as part of a marker-aided selection and breeding effort or to expedite the isolation and characterization of genes and/or promoters that directly control wood properties. The objectives of this project are: (1) to apply new and rapid analytical techniques for assessing component wood properties to segregating F2 progeny populations of loblolly pine and hybrid poplar, (2) to map quantitative trait loci and identify molecular markers associated with wood properties in each of the above species and (3) to validate marker-aided selection methods for wood properties in loblolly pine and hybrid poplar.

  3. Variation in the Growth Traits and Wood Properties of Chinese Fir from Six Provinces of Southern China

    Directory of Open Access Journals (Sweden)

    Hongjing Duan

    2016-08-01

    Full Text Available To determine the phenotypic variation in 700 ten-year grafted Chinese fir collected from six provinces in southern China, 10 phenotypic traits were investigated: tree height, diameter at breast height, bark thickness, volume of timber, heartwood ratio, density of wood, hygroscopicity, tracheid length, tracheid diameter, and ratio of tracheid length to tracheid diameter. Abundant phenotypic variation was found among the six populations; the phenotypic variation coefficients all exceeded 10%, and the largest was for volume of timber. Significant variation (p < 0.01 or 0.05 in traits was found among the populations, except for diameter at breast height, heartwood ratio, and tracheid diameter, while all traits differed significantly (p < 0.01 within populations. The high value of repeatability (broad-sense heritability suggested moderate genetic control of the traits. The 10 traits were strongly correlated within the entire population; strong positive correlations (p < 0.01 were observed between growth traits, and significant negative correlations (p < 0.01 or 0.05 were found between the density of wood and most other characteristics, except for heartwood ratio and ratio of tracheid length to tracheid diameter. Using diameter at breast height and density of wood as criteria, 98 relatively fast-growing genotypes with relatively high wood basic density were identified.

  4. WOOD PROPERTIES AND EFFECT OF WOOD PROPERTIES ON THE WOOD FINISHING

    Directory of Open Access Journals (Sweden)

    Abdulkadir Malkoçoğlu

    2006-04-01

    Full Text Available Wood is basic raw material for furniture and joinery industries with wood structures. Wood is a biological material that has widely different properties depending on species, geographic area where the tree grew, the growth condition, size of the tree at harvest, sawing, and other manufacturing processes. Wood properties have been characterized within two groups as natural and manufacturing factors that effects finishing performance. Grow rate, density, knots, moisture content, extractives and juvenile wood are natural characteristics. Grain orientation, texture, drying and performance expectations are manufacturing characteristics. In this review, the effects of natural and manufacturing characteristics are discussed on the surface finishing performance of wood.

  5. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

    Full Text Available In this study, the combustion properties of some impregnation materials (abiotic and biotic factors used for eucalyptus wood in interior or exterior environments were investigated. The experimental samples were prepared from Eucalyptus wood based on ASTM-D-1413-76 Tanalith-CBC, boric acid, borax, vacsol-WR, immersol-WR, polyethylen glycole-400 and ammonium sulphate were used as an impregnation material. The results indicated that, vacuum treatment on Eucalyptus gave the lowest retention value of salts. Compounds containing boron+salt increased fire resistance however water repellents decreased the wood flammability.

  6. Moisture relations and physical properties of wood

    Science.gov (United States)

    Samuel V. Glass; Samuel L. Zelinka

    2010-01-01

    Wood, like many natural materials, is hygroscopic; it takes on moisture from the surrounding environment. Moisture exchange between wood and air depends on the relative humidity and temperature of the air and the current amount of water in the wood. This moisture relationship has an important influence on wood properties and performance. Many of the challenges of using...

  7. Selected mechanical properties of modified beech wood

    Directory of Open Access Journals (Sweden)

    Jiří Holan

    2008-01-01

    Full Text Available This thesis deals with an examination of mechanical properties of ammonia treated beach wood with a trademark Lignamon. For determination mechanical properties were used procedures especially based on ČSN. From the results is noticeable increased density of wood by 22% in comparison with untreated beach wood, which makes considerable increase of the most mechanical wood properties. Considering failure strength was raised by 32% and modulus of elasticity was raised at average about 46%.

  8. Acoustic and adsorption properties of submerged wood

    Science.gov (United States)

    Hilde, Calvin Patrick

    Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood.

  9. Intraspecific variability of European larch for wood properties: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Paques, L.E.; Rozenberg, P. [Institut National de Recherches Agronomiques (INRA), 45 - Olivet (France). Station d`Amelioration des Arbres Forestiers

    1995-12-31

    Wood properties of several natural populations of European larch (Larix decidua Mill) were determined from samples collected in one replicate of the II. International IUFRO provenance experiment, planted in Brittany in 1959. According to provenances, proportion of heartwood ranges from 35 to 58% of basal area, basic density from 442 to 505 g/dm{sup 3} and Young modulus of elasticity from 8474 to 14522 MPa. Positive correlations between girth and heartwood proportion and between wood density and modulus of elasticity but negative correlations between ring width and both density and MOE have been found both at the individual and at the population levels. Variability between and within provenances is high for two major traits (proportion of heartwood and Young modulus of elasticity) for which a SW - NE gradient is shown. For wood density parameters including pilodyn, a greater homogeneity is observed. Besides a now largely recognized superiority for growth traits, Central European populations from the Sudetan Mountains and Central Poland would also produce wood with better properties. On the reverse, Alpine populations from the French Alps growing at low elevations have a slower growth, a denser wood with less heartwood and less strength. Used as a control, the hybrid larch origin (Larix x eurolepis) represents the best compromise for wood properties with the highest strength but an average wood density and one of the highest proportion of heartwood. These preliminary results must be confirmed from a larger set of provenances and completed with other major wood properties such as durability and shrinkage. 17 refs, 2 figs, 6 tabs

  10. Intraspecific variability of European larch for wood properties: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Paques, L E; Rozenberg, P [Institut National de Recherches Agronomiques (INRA), 45 - Olivet (France). Station d` Amelioration des Arbres Forestiers

    1996-12-31

    Wood properties of several natural populations of European larch (Larix decidua Mill) were determined from samples collected in one replicate of the II. International IUFRO provenance experiment, planted in Brittany in 1959. According to provenances, proportion of heartwood ranges from 35 to 58% of basal area, basic density from 442 to 505 g/dm{sup 3} and Young modulus of elasticity from 8474 to 14522 MPa. Positive correlations between girth and heartwood proportion and between wood density and modulus of elasticity but negative correlations between ring width and both density and MOE have been found both at the individual and at the population levels. Variability between and within provenances is high for two major traits (proportion of heartwood and Young modulus of elasticity) for which a SW - NE gradient is shown. For wood density parameters including pilodyn, a greater homogeneity is observed. Besides a now largely recognized superiority for growth traits, Central European populations from the Sudetan Mountains and Central Poland would also produce wood with better properties. On the reverse, Alpine populations from the French Alps growing at low elevations have a slower growth, a denser wood with less heartwood and less strength. Used as a control, the hybrid larch origin (Larix x eurolepis) represents the best compromise for wood properties with the highest strength but an average wood density and one of the highest proportion of heartwood. These preliminary results must be confirmed from a larger set of provenances and completed with other major wood properties such as durability and shrinkage. 17 refs, 2 figs, 6 tabs

  11. Growth and wood properties of genetically improved loblolly pine: propagation type comparison and genetic parameters

    Science.gov (United States)

    Finto Antony; Laurence Schimleck; Lewis Jordan; Benjamin Hornsby; Joseph Dahlen; Richard Daniels; Alexander Clark; Luis Apiolaza; Dudley Huber

    2013-01-01

    The use of clonal varieties in forestry offers great potential to improve growth traits (quantity) and wood properties (quality) of loblolly pine (Pinus taeda L.). Loblolly pine trees established via somatic embryogenesis (clones), full-sib zygotic crosses, and half-sib zygotic open-pollinated families were sampled to identify variation in growth and wood properties...

  12. Micromechanical measurement of wood substructure properties.

    Science.gov (United States)

    David E. Kretschmann; Troy W. Schmidt; Roderic S. Lakes; Steven M. Cramer

    2002-01-01

    The annual rings of softwoods are visually obvious and represent cylindrical layers of primarily cellulosic material that possess significantly different properties. For simplicity, wood construction products are designed assuming a material homogeneity that does not exist. As rapidly grown plantation trees are used for wood products, fewer rings are contained in an...

  13. The trait contribution to wood decomposition rates of 15 Neotropical tree species.

    Science.gov (United States)

    van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C

    2010-12-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems.

  14. The trait contribution to wood decomposition rates of 15 neotropical tree species

    NARCIS (Netherlands)

    Geffen, van K.G.; Poorter, L.; Sass-Klaassen, U.; Logtestijn, R.S.P.; Cornelissen, J.H.C.

    2010-01-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of inter-specific variation in species traits on differences wood

  15. Termites amplify effects of wood traits on decomposition rates among multiple bamboo and dicot woody species

    NARCIS (Netherlands)

    Liu, Guofang; Cornwell, W.K.; Cao, Kunfang; Hu, Yukun; van Logtestijn, R.S.P; Yang, Shijian; Xie, Xiufang; Zhang, Yalin; Ye, Duo; Pan, Xu; Ye, Xuehua; Huang, Zhenying; Dong, Ming; Cornelissen, J.H.C.

    2015-01-01

    Wood decomposition is a key process in the terrestrial carbon cycle, controlling carbon storage with feedback to climate. In (sub) tropical forest, termites are major players in wood decomposition, but their role relative to that of microbial decomposers and wood traits of different tree species is

  16. Integration of vessel traits, wood density, and height in angiosperm shrubs and trees.

    Science.gov (United States)

    Martínez-Cabrera, Hugo I; Schenk, H Jochen; Cevallos-Ferriz, Sergio R S; Jones, Cynthia S

    2011-05-01

    Trees and shrubs tend to occupy different niches within and across ecosystems; therefore, traits related to their resource use and life history are expected to differ. Here we analyzed how growth form is related to variation in integration among vessel traits, wood density, and height. We also considered the ecological and evolutionary consequences of such differences. In a sample of 200 woody plant species (65 shrubs and 135 trees) from Argentina, Mexico, and the United States, standardized major axis (SMA) regression, correlation analyses, and ANOVA were used to determine whether relationships among traits differed between growth forms. The influence of phylogenetic relationships was examined with a phylogenetic ANOVA and phylogenetically independent contrasts (PICs). A principal component analysis was conducted to determine whether trees and shrubs occupy different portions of multivariate trait space. Wood density did not differ between shrubs and trees, but there were significant differences in vessel diameter, vessel density, theoretical conductivity, and as expected, height. In addition, relationships between vessel traits and wood density differed between growth forms. Trees showed coordination among vessel traits, wood density, and height, but in shrubs, wood density and vessel traits were independent. These results hold when phylogenetic relationships were considered. In the multivariate analyses, these differences translated as significantly different positions in multivariate trait space occupied by shrubs and trees. Differences in trait integration between growth forms suggest that evolution of growth form in some lineages might be associated with the degree of trait interrelation.

  17. Combustion properties of wood impregnated with commercial ...

    African Journals Online (AJOL)

    The objective of this study was to determine some combustion properties of Calabrian pine (Pinus brutia Ten.) wood specimens impregnated with aqueous solutions of commercial fertilizers. Ammonium sulphate (AS) and diammonium phosphate (DAP) were used as commercial fertilizers. Diammonium phosphate and ...

  18. Leaf photosynthetic traits scale with hydraulic conductivity and wood density in Panamanian forest canopy trees.

    Science.gov (United States)

    L.S. Santiago; G. Goldstein; F.C. Meinzer; J.B. Fisher; K. Maehado; D. Woodruff; T. Jones

    2004-01-01

    We investigated how water transport capacity, wood density and wood anatomy were related to leaf photosynthetic traits in two lowland forests in Panama. Leaf-specific hydraulic conductivity (kL) of upper branches was positively correlated with maximum rates of net CO2, assimilation per unit leaf area (Aarea...

  19. The trait contribution to wood decomposition rates of 15 Neotropical tree species.

    NARCIS (Netherlands)

    van Geffen, K.G.; Poorter, L.; Sass-Klaassen, U.; van Logtestijn, R.S.P; Cornelissen, J.H.C.

    2010-01-01

    The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in

  20. Genetic variation in growth and wood-quality traits of Corymbia ...

    African Journals Online (AJOL)

    Ten growth or wood-quality traits were assessed in three nearby Corymbia citriodora subsp. variegata (CCV) open-pollinated family-within-provenance trials (18 provenances represented by a total of 374 families) to provide information for the development of a breeding program targeting both pulp and solid-wood products.

  1. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    come from? How is it harvested? How is it manufactured and treated ? How are the buildings detailed and protected against weather during construction to keep them dry and make them long-life ? In a period of climate change, forests are the last lungs of the planet to sequestrate CO2. Their global size......Wood – a sustainable building material ? For thousands of years and all over the planet, wood has been used as a building material and exciting architecture has been created in wood. The fantastic structural, physical and aesthetic properties of the material as well as the fact that wood...

  2. Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield

    Science.gov (United States)

    Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

    2016-01-01

    In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0–14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ13C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ13C, both hydraulic efficiency and embolism resistance were

  3. Influence of wood defects on some mechanical properties of two ...

    African Journals Online (AJOL)

    Effects of slope of wood grain, knot, split, ingrowth and sapwood on some mechanical wood properties of Pterygota macrocarpa (Kyere) and Piptadeniastrum africanum (Dahoma) have been studied, using structural size specimens and a 60 tonne structural wood testing machine. The study on the two tropical hardwoods ...

  4. Furniture wood wastes: Experimental property characterisation and burning tests

    International Nuclear Information System (INIS)

    Tatano, Fabio; Barbadoro, Luca; Mangani, Giovanna; Pretelli, Silvia; Tombari, Lucia; Mangani, Filippo

    2009-01-01

    Referring to the industrial wood waste category (as dominant in the provincial district of Pesaro-Urbino, Marche Region, Italy), this paper deals with the experimental characterisation and the carrying out of non-controlled burning tests (at lab- and pilot-scale) for selected 'raw' and primarily 'engineered' ('composite') wood wastes. The property characterisation has primarily revealed the following aspects: potential influence on moisture content of local weather conditions at outdoor wood waste storage sites; generally, higher ash contents in 'engineered' wood wastes as compared with 'raw' wood wastes; and relatively high energy content values of 'engineered' wood wastes (ranging on the whole from 3675 to 5105 kcal kg -1 for HHV, and from 3304 to 4634 kcal kg -1 for LHV). The smoke qualitative analysis of non-controlled lab-scale burning tests has primarily revealed: the presence of specific organic compounds indicative of incomplete wood combustion; the presence exclusively in 'engineered' wood burning tests of pyrroles and amines, as well as the additional presence (as compared with 'raw' wood burning) of further phenolic and containing nitrogen compounds; and the potential environmental impact of incomplete industrial wood burning on the photochemical smog phenomenon. Finally, non-controlled pilot-scale burning tests have primarily given the following findings: emission presence of carbon monoxide indicative of incomplete wood combustion; higher nitrogen oxide emission values detected in 'engineered' wood burning tests as compared with 'raw' wood burning test; and considerable generation of the respirable PM 1 fraction during incomplete industrial wood burning.

  5. Association Genetics of Wood Physical Traits in the Conifer White Spruce and Relationships With Gene Expression

    Science.gov (United States)

    Beaulieu, Jean; Doerksen, Trevor; Boyle, Brian; Clément, Sébastien; Deslauriers, Marie; Beauseigle, Stéphanie; Blais, Sylvie; Poulin, Pier-Luc; Lenz, Patrick; Caron, Sébastien; Rigault, Philippe; Bicho, Paul; Bousquet, Jean; MacKay, John

    2011-01-01

    Marker-assisted selection holds promise for highly influencing tree breeding, especially for wood traits, by considerably reducing breeding cycles and increasing selection accuracy. In this study, we used a candidate gene approach to test for associations between 944 single-nucleotide polymorphism markers from 549 candidate genes and 25 wood quality traits in white spruce. A mixed-linear model approach, including a weak but nonsignificant population structure, was implemented for each marker–trait combination. Relatedness among individuals was controlled using a kinship matrix estimated either from the known half-sib structure or from the markers. Both additive and dominance effect models were tested. Between 8 and 21 single-nucleotide polymorphisms (SNPs) were found to be significantly associated (P ≤ 0.01) with each of earlywood, latewood, or total wood traits. After controlling for multiple testing (Q ≤ 0.10), 13 SNPs were still significant across as many genes belonging to different families, each accounting for between 3 and 5% of the phenotypic variance in 10 wood characters. Transcript accumulation was determined for genes containing SNPs associated with these traits. Significantly different transcript levels (P ≤ 0.05) were found among the SNP genotypes of a 1-aminocyclopropane-1-carboxylate oxidase, a β-tonoplast intrinsic protein, and a long-chain acyl-CoA synthetase 9. These results should contribute toward the development of efficient marker-assisted selection in an economically important tree species. PMID:21385726

  6. Wood Properties and Kinds; A Base Syllabus on Wood Technology.

    Science.gov (United States)

    Eastern Kentucky Univ., Richmond.

    Prepared by participants in the 1968 National Defense Education Act Institute on Wood Technology, this syllabus is one of a series of basic outlines designed to aid college level industrial arts instructors in improving and broadening the scope and content of their programs. This booklet is concerned largely with the physical composition and…

  7. Thermal Properties of Wood-Plastic Composites Prepared from Hemicellulose-extracted Wood Flour

    Directory of Open Access Journals (Sweden)

    A.A. Enayati

    2013-01-01

    Full Text Available Hemicellulose of Southern Yellow Pine wood spices was extracted by pressurized hot water at three different temperatures: 140°C, 155°C and 170°C. Compounding with PP (polypropylene was performed by extrusion after preparing wood flour and sieving to determine its mesh size. The ratio of wood to polymer was 50:50 based on oven-dry weight of wood flour. All extraction treatments and control samples were compounded under two sets of conditions, without and with 2% MAPP as coupling agent. Injection molding was used to make tensile test samples (dogbone from the pellets made by extrusion. Thermal properties of wood-plastic composites were studied by TGA and DSC while the thermal stability of pretreated wood flours, PP and MAPP were studied by TGA as well. The greater weight loss of wood materials was an indication that higher treatment temperature increases the extractability of hemicellulose. The removal of hemicellulose by extraction improves thermal stability of wood flour, especially for extraction at 170°C. Wood-plastic composites made from extracted fibers at 170°C showed the highest thermal stability. Coupling agent did not have a significant effect on thermal stability but it improved the degree of crystallinity of the composites.Surface roughness of wood fiber increased after treatment. Extraction of hemicellulose increased the degree of crystallinity but it was not significant except for samples from treated wood flour at 170°C and with MAPP.

  8. Identification of quantitative trait loci influencing wood specific gravity in an outbred pedigree of loblolly pine

    Science.gov (United States)

    A. Groover; M. Devey; T. Fiddler; J. Lee; R. Megraw; T. Mitchel-Olds; B. Sherman; S. Vujcic; C. Williams; D. Neale

    1994-01-01

    We report the identification of quantitative trait loci (QTL) influencing wood specific gravity (WSG) in an outbred pedigree of loblolly pine (Pinus taeda L.) . QTL mapping in an outcrossing species is complicated by the presence of multiple alleles (>2) at QTL and marker loci. Multiple alleles at QTL allow the examination of interaction among...

  9. Properties of wood-plastic composites (WPCs) reinforced with extracted and delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2014-01-01

    The water sorption and mechanical properties of wood-plastic composites (WPCs) made of extracted and delignified wood flour (WF) has been investigated. WF was prepared by extraction with the solvent systems toluene/ethanol (TE), acetone/water (AW), and hot water (HW), and its delignification was conducted by means of sodium chlorite/acetic acid (AA) solution. A 2 4...

  10. Plant trait-species abundance relationships vary with environmental properties in subtropical forests in eastern china.

    Directory of Open Access Journals (Sweden)

    En-Rong Yan

    Full Text Available Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N and phosphorus (P contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA, leaf N concentration (LN, and total leaf area per twig size (TLA were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests.

  11. Wood anatomical and chemical properties related to the pulpability ...

    African Journals Online (AJOL)

    Eucalyptus globulus is one of the most important hardwood species used by the pulp and paper industry due to its high pulp yield, high wood density, excellent fibre quality and good handsheet properties. However, the wood is a highly variable and complex material that has different chemical, physical and anatomical ...

  12. Studies of properties of rubber wood with impregnation of polymer

    Indian Academy of Sciences (India)

    Impregnation of rubber wood has been carried out under different conditions by using styrene as grafting monomer and glycidyl methacrylate (GMA) as crosslinker. Properties such as dimensional stability, water absorption, hardness, tensile strength, flexural strength, etc of the impregnated wood have been checked and ...

  13. Physical, mechanical, and biodegradable properties of meranti wood polymer composites

    International Nuclear Information System (INIS)

    Enamul Hoque, M.; Aminudin, M.A.M.; Jawaid, M.; Islam, M.S.; Saba, N.; Paridah, M.T.

    2014-01-01

    Highlights: • In-situ polymerization and solution casting method used to manufacture WPC. • In-situ WPC exhibited better properties compared to pure wood, 5% WPC and 20% WPC. • Lowest water absorption and least biodegradability shown by In-situ wood. - Abstract: In-situ polymerization and solution casting techniques are two effective methods to manufacture wood polymer composites (WPCs). In this study, wood polymer composites (WPCs) were manufactured from meranti sapwood by solution casting and in-situ polymerization process using methyl methacrylate (MMA) and epoxy matrix respectively. Physical, mechanical, and morphological characterizations of fabricated WPCs were then carried out to analyse their properties. Morphological properties of composites samples were analyzed through scanning electron microscopy (SEM). The result reveals that in-situ wood composite exhibited better properties compared to pure wood, 5% WPC and 20% WPC. Moreover, in-situ WPC had lowest water absorption and least biodegraded. Conversely, pure wood shown moderate mechanical strength, high biodegradation and water absorption rate. In term of biodegradation, earth-medium brought more severe effect than water in deteriorating the properties of the specimens

  14. Growth and Wood/Bark Properties of Abies faxoniana Seedlings as Affected by Elevated CO2

    Institute of Scientific and Technical Information of China (English)

    Yun-Zhou Qiao; Yuan-Bin Zhang; Kai-Yun Wang; Qian Wang; Qi-Zhuo Tian

    2008-01-01

    Growth and wood and bark properties of Abies faxoniana seedlings after one year's exposure to elevated CO2 concentration (ambient + 350 (=1= 25) μmol/mol) under two planting densities (28 or 84 plants/mz) were investigated in closed-top chambers. Tree height, stem diameter and cross-sectional area, and total biomass were enhanced under elevated CO2 concentration, and reduced under high planting density. Most traits of stem bark were improved under elevated CO2 concentration and reduced under high planting density. Stem wood production was significantly increased in volume under elevated CO2 concentration under both densities, and the stem wood density decreased under elevated CO2 concentration and increased under high planting density. These results suggest that the response of stem wood and bark to elevated CO2 concentration is density dependent. This may be of great importance in a future CO2 enriched world in natural forests where plant density varies considerably. The results also show that the bark/wood ratio in diameter, stem cross-sectional area and dry weight are not proportionally affected by elevated CO2 concentration under the two contrasting planting densities. This indicates that the response magnitude of stem bark and stem wood to elevated CO2 concentration are different but their response directions are the same.

  15. The influence of irradiated wood filler on some properties of polypropylene - wood composites

    Directory of Open Access Journals (Sweden)

    Điporović-Momčilović Milanka

    2007-01-01

    Full Text Available The problem of compatibility between the wood filler and thermoplastic matrix is of essential importance in composite production. Numerous methods have been developed for increasing this compatibility, which is still representing a challenging objective of composite research throughout the world. The research into these methods is primarily directed towards their efficiency from the viewpoint of the composite performance and their economical acceptability. The latter is of particular importance for the composite production in the developing countries with respect to the shortage of the corresponding funds. With this respect, the utilization of ionizing radiation might have considerable advantages. In this research, the beech wood flour was irradiated by a dose of 10 kGy of 60Co gamma rays for purpose of provoking the changes by the ionizing effect. The effects of ionizing radiation upon the properties of wood particles have been examined by IR spectroscopy and by determination of contents of hydroxyl groups in wood by acetylating as an indirect method. All these methods have been expected to reveal the chemical effects of the applied radiation treatment. The irradiated and the control wood flour were used in order to produce the samples of composite with polypropylene. The polypropylene-wood flour (PP-WF composites were produced with 40% of wood particles having fraction size 0.3 mm. The melt-blended composites were modified with amido-acrylic acid (AMACA as a new coupling agent synthesized for this propose in amount of 6 wt.% (based on wood filler and successively with 0.05 wt.% (based on PP of organic peroxide during mixing step. The composites containing coupling agents showed superior mechanical properties, compared to the untreated one. The highest extent of improvement of tensile was achieved in PP-WFl composites modified with AMACA coupling agent.

  16. Community-weighted mean of leaf traits and divergence of wood traits predict aboveground biomass in secondary subtropical forests.

    Science.gov (United States)

    Ali, Arshad; Yan, En-Rong; Chang, Scott X; Cheng, Jun-Yang; Liu, Xiang-Yu

    2017-01-01

    Subtropical forests are globally important in providing ecological goods and services, but it is not clear whether functional diversity and composition can predict aboveground biomass in such forests. We hypothesized that high aboveground biomass is associated with high functional divergence (FDvar, i.e., niche complementarity) and community-weighted mean (CWM, i.e., mass ratio; communities dominated by a single plant strategy) of trait values. Structural equation modeling was employed to determine the direct and indirect effects of stand age and the residual effects of CWM and FDvar on aboveground biomass across 31 plots in secondary forests in subtropical China. The CWM model accounted for 78, 20, 6 and 2% of the variation in aboveground biomass, nitrogen concentration in young leaf, plant height and specific leaf area of young leaf, respectively. The FDvar model explained 74, 13, 7 and 0% of the variation in aboveground biomass, plant height, twig wood density and nitrogen concentration in young leaf, respectively. The variation in aboveground biomass, CWM of leaf nitrogen concentration and specific leaf area, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf explained by the joint model was 86, 20, 13, 7, 2 and 0%, respectively. Stand age had a strong positive direct effect but low indirect positive effects on aboveground biomass. Aboveground biomass was negatively related to CWM of nitrogen concentration in young leaf, but positively related to CWM of specific leaf area of young leaf and plant height, and FDvar of plant height, twig wood density and nitrogen concentration in young leaf. Leaf and wood economics spectra are decoupled in regulating the functionality of forests, communities with diverse species but high nitrogen conservative and light acquisitive strategies result in high aboveground biomass, and hence, supporting both the mass ratio and niche complementarity hypotheses in secondary subtropical forests

  17. Chapter 5:Biological Properties of Wood

    Science.gov (United States)

    Rebecca E. Ibach

    2013-01-01

    There are numerous biological degradations that wood is exposed to in various environments. Biological damage occurs when a log, sawn product, or final product is not stored, handled, or designed properly. Biological organisms such as bacteria, mold, stain, decay fungi, insects, and marine borers depend heavily on temperature and moisture conditions to grow. Figure 5.1...

  18. Tools to Understand Structural Property Relationships for Wood Cell Walls

    Science.gov (United States)

    Joseph E. Jakes; Daniel J. Yelle; Charles R. Frihart

    2011-01-01

    Understanding structure-property relationships for wood cell walls has been hindered by the complex polymeric structures comprising these cell walls and the difficulty in assessing meaningful mechanical property measurements of individual cell walls. To help overcome these hindrances, we have developed two experimental methods: 1) two-dimensional solution state nuclear...

  19. Influence of lignin on properties of wood-inorganic sorbents

    International Nuclear Information System (INIS)

    Remez, V.P.; Charina, M.V.; Klass, S.M.; Shubin, A.S.; Tkachev, K.V.; Isaeva, O.F.

    1986-01-01

    Present article is devoted to influence of lignin on properties of wood-inorganic sorbents. The influence of component composition of matrix on sorption properties of sorbents and their stability in different mediums is studied. The dependence of sorption capacity of sorbent on component matrix composition and its porous structure is defined.

  20. Fabrication and Spectral Properties of Wood-Based Luminescent Nanocomposites

    Directory of Open Access Journals (Sweden)

    Xianjun Li

    2014-01-01

    Full Text Available Pressure impregnation pretreatment is a conventional method to fabricate wood-based nanocomposites. In this paper, the wood-based luminescent nanocomposites were fabricated with the method and its spectral properties were investigated. The results show that it is feasible to fabricate wood-based luminescent nanocomposites using microwave modified wood and nanophosphor powders. The luminescent strength is in positive correlation with the amount of phosphor powders dispersed in urea-formaldehyde resin. Phosphors absorb UV and blue light efficiently in the range of 400–470 nm and show a broad band of bluish-green emission centered at 500 nm, which makes them good candidates for potential blue-green luminescent materials.

  1. PHYSICAL AND MECHANICAL PROPERTIES OF JUVENILE Schizolobium amazonicum WOOD

    Directory of Open Access Journals (Sweden)

    Graziela Baptista Vidaurre

    2018-03-01

    Full Text Available ABSTRACT Growth in world demand for wood implies a search for new fast growing species with silvicultural potential, and in this scenario for native species such as Paricá . Thus, the objective of this study was determining the physical and mechanical wood properties of the Schizolobium amazonicum species (known as Paricá in Brazil. Trees were collected from commercial plantations located in the north of Brazil with ages of 5, 7, 9 and 11 years. Four logs from trees of each age in the longitudinal direction of the trees were obtained, and later a diametrical plank of each log was taken to manufacture the specimens which were used to evaluate some physical and mechanical properties of the wood. The basic density of Paricá was reduced in the basetop direction and no difference between the radial positions was observed, while the average basic density of this wood was characterized as low. The region close to the bark showed less longitudinal contraction and also greater homogeneity of this property along the trunk, while for tangential contraction the smallest variation was found in the region near the pith. Paricá wood contraction was characterized as low. Age influenced most of the mechanical properties, where logs from the base had the highest values of mechanical strength.

  2. Temperature dependence of the dielectric properties of rubber wood

    Science.gov (United States)

    Mohammed Firoz Kabir; Wan M. Daud; Kaida B. Khalid; Haji A.A. Sidek

    2001-01-01

    The effect of temperature on the dielectric properties of rubber wood was investigated in three anisotropic directions—longitudinal, radial, and tangential, and at different measurement frequencies. Low frequency measurements were conducted with a dielectric spectrometer, and high frequencies used microwave applied with open-ended coaxial probe sensors. Dielectric...

  3. Some Properties of Astronium graveolens Wood Along the Stem

    OpenAIRE

    Longui,Eduardo Luiz; Gondo,Cássia Christine Schmidt; Luiz de Lima,Israel; Freitas,Miguel Luiz Menezes; Florsheim,Sandra Monteiro Borges; Zanatto,Antonio Carlos Scatena; Garcia,José Nivaldo

    2016-01-01

    ABSTRACT We investigated the axial variation of specific gravity, shear parallel to the grain and anatomical features of Astronium graveolens wood and related these properties to the anatomy along the stem. We felled five 20-year-old trees and cut discs from four different stem heights, including stem base, 1 meter, 2 meters and 3 meters, for a total of 20 discs, and studied wood samples near the bark and at the base of trunk. Axial variations found appear to provide a balance between mechani...

  4. Some Properties of Astronium graveolens Wood Along the Stem

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Longui

    Full Text Available ABSTRACT We investigated the axial variation of specific gravity, shear parallel to the grain and anatomical features of Astronium graveolens wood and related these properties to the anatomy along the stem. We felled five 20-year-old trees and cut discs from four different stem heights, including stem base, 1 meter, 2 meters and 3 meters, for a total of 20 discs, and studied wood samples near the bark and at the base of trunk. Axial variations found appear to provide a balance between mechanical strength of the wood at stem base by the higher density and higher shear by the increase in ray frequency that contributes to locking the vertical cells and growth rings, thus preventing the stem from easily breaking when bent. For hydraulic conductivity, vessels with smaller diameter and frequency at the stem base help prevent the occurrence of embolisms that would reduce water flow along the main stem.

  5. Mechanical properties: wood lumber versus plastic lumber and thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Bernardo Zandomenico Dias

    Full Text Available Abstract Plastic lumber and thermoplastic composites are sold as alternatives to wood products. However, many technical standards and scientific studies state that the two materials cannot be considered to have the same structural behaviour and strength. Moreover, there are many compositions of thermoplastic-based products and plenty of wood species. How different are their mechanical properties? This study compares the modulus of elasticity and the flexural, compressive, tensile and shear strengths of such materials, as well as the materials' specific mechanical properties. It analyses the properties of wood from the coniferae and dicotyledon species and those of commercialized and experimental thermoplastic-based product formulations. The data were collected from books, scientific papers and manufacturers' websites and technical data sheets, and subsequently compiled and presented in Ashby plots and bar graphs. The high values of the compressive strength and specific compressive and tensile strengths perpendicular to the grain (width direction shown by the experimental thermoplastic composites compared to wood reveal their great potential for use in compressed elements and in functions where components are compressed or tensioned perpendicularly to the grain. However, the low specific flexural modulus and high density of thermoplastic materials limit their usage in certain civil engineering and building applications.

  6. BASIC PROPERTIES IN RELATION TO DRYING PROPERTIES OF THREE WOOD SPECIES FROM INDONESIA

    Directory of Open Access Journals (Sweden)

    Efrida Basri

    2005-03-01

    Full Text Available The objectives of this study were to investigate basic and drying properties of three wood species from Indonesia, i.e. kuda (Lannea coromandelica Merr., waru (Hibiscus tiliaceus L. and mindi besar (Melia dubia Cav.. The basic properties include density, shrinkages, modulus of rupture (MOR, compression parallel to grain (C//, wood strength and anatomical structures. Meanwhile, the drying properties included drying time and drying defects. The initial-final temperature and humidity for each species was based on defects that resulted from high temperature drying trial. The results showed that the drying properties were significantly affected by wood anatomical structure. The initial-final drybulb temperature and wetbulb depression   for kuda wood are 50 -70ºC and 3-30ºC respectively, while the corresponding figures for waru wood are 65-80ºC and 6-30ºC, and for mindi besar wood are 55-80ºC and 4-30ºC. These drying schedules, however, still need further trial prior to their implementation in the factory-scale operation. All wood species studied have density and considerable strength recommended in their use for light medium construction purposes. Mindi besar wood has decorative appearance so it is suitable for furniture.

  7. Hydraulic and mechanical properties of young Norway spruce clones related to growth and wood structure

    Science.gov (United States)

    ROSNER, SABINE; KLEIN, ANDREA; MÜLLER, ULRICH; KARLSSON, BO

    2011-01-01

    Summary Stem segments of eight five-year-old Norway spruce (Picea abies (L.) Karst.) clones differing in growth characteristics were tested for maximum specific hydraulic conductivity (ks100), vulnerability to cavitation and behavior under mechanical stress. The vulnerability of the clones to cavitation was assessed by measuring the applied air pressure required to cause 12 and 50% loss of conductivity (Ψ12, Ψ50) and the percent loss of conductivity at 4 MPa applied air pressure (PLC4MPa). The bending strength and stiffness and the axial compression strength and stiffness of the same stem segments were measured to characterize wood mechanical properties. Growth ring width, wood density, latewood percentage, lumen diameter, cell wall thickness, tracheid length and pit dimensions of earlywood cells, spiral grain and microfibril angles were examined to identify structure–function relationships. High ks100 was strongly and positively related to spiral grain angle, which corresponded positively to tracheid length and pit dimensions. Spiral grain may reduce flow resistance of the bordered pits of the first earlywood tracheids, which are characterized by rounded tips and an equal distribution of pits along the entire length. Wood density was unrelated to hydraulic vulnerability parameters. Traits associated with higher hydraulic vulnerability were long tracheids, high latewood percentage and thick earlywood cell walls. The positive relationship between earlywood cell wall thickness and vulnerability to cavitation suggest that air seeding through the margo of bordered pits may occur in earlywood. There was a positive phenotypic and genotypic relationship between ks100 and PLC4MPa, and both parameters were positively related to tree growth rate. Variability in mechanical properties depended mostly on wood density, but also on the amount of compression wood. Accordingly, hydraulic conductivity and mechanical strength or stiffness showed no tradeoff. PMID:17472942

  8. Extractive and anatomical wood structure effects on mechanical properties of Caoba wood (Swietenia macrophylla King)

    International Nuclear Information System (INIS)

    Arevalo Fuentes Rosven Libardo; Hernandez Roger

    2008-01-01

    The compression tangential to grain of samples of mahogany wood from Peru was examined at different relative humidity levels at 25 Celsius degrade to determine the influence of both extractives and anatomical structure. Matched samples were used to assess the percentage of extractive components by extraction with solvents of increasing polarity: cyclohexane, dichloromethane, acetone, methanol and hot water. Additionally, fourteen anatomical parameters were determined by image analysis. Stepwise regression analysis concluded that mainly anatomical features, such as rays and vessels, rather than extractives, affect the mechanical behaviour of mahogany. These findings are agree with earlier results showing a negative effect of large and multiseriate rays on the mechanical properties of wood when loaded perpendicularly to their long axis. The influence of lumen located extracts soluble in dichloromethane might disallow deformations. Finally, it is postulated that hot water extracts may play a plasticizing role in this species.

  9. Construction of Hydrophobic Wood Surface and Mechanical Property of Wood Cell Wall on Nanoscale Modified by Dimethyldichlorosilane

    Science.gov (United States)

    Yang, Rui; Wang, Siqun; Zhou, Dingguo; Zhang, Jie; Lan, Ping; Jia, Chong

    2018-01-01

    Dimethyldichlorosilane was used to improve the hydrophobicity of wood surface. The water contact angle of the treated wood surface increased from 85° to 143°, which indicated increased hydrophobicity. The nanomechanical properties of the wood cell wall were evaluated using a nanoindentation test to analyse the hydrophobic mechanism on the nano scale. The elastic modulus of the cell wall was significantly affected by the concentration but the influence of treatment time is insignificant. The hardness of the cell wall for treated samples was significantly affected by both treatment time and concentration. The interaction between treatment time and concentration was extremely significant for the elastic modulus of the wood cell wall.

  10. Studies on Solid Wood. II. The Influence of Chemical Modifications on Viscoelastic Properties

    DEFF Research Database (Denmark)

    Bjørkmann, Anders; Salmén, Lennart

    2000-01-01

    The relation between the properties of wood polymers and those of the composite material of wood is a subject that has been of interest for a long time. In order to increase oar knowledge in this matter, changes of wood properties have been studied on samples of spruce and birch, subjected to var...

  11. Enhanced understanding of the relationship between chemical modification and mechanical properties of wood

    Science.gov (United States)

    Charles R. Frihart; Daniel J. Yelle; John Ralph; Robert J. Moon; Donald S. Stone; Joseph E. Jakes

    2008-01-01

    Chemical additions to wood often change its bulk properties, which can be determined using conventional macroscopic mechanical tests. However, the controlling interactions between chemicals and wood take place at and below the scale of individual cells and cell walls. To better understand the effects of chemical additions to wood, we have adapted and extended two...

  12. Wood

    Science.gov (United States)

    David W. Green; Robert H. White; Antoni TenWolde; William Simpson; Joseph Murphy; Robert J. Ross; Roland Hernandez; Stan T. Lebow

    2006-01-01

    Wood is a naturally formed organic material consisting essentially of elongated tubular elements called cells arranged in a parallel manner for the most part. These cells vary in dimensions and wall thickness with position in the tree, age, conditions of growth, and kind of tree. The walls of the cells are formed principally of chain molecules of cellulose, polymerized...

  13. The properties of the wood-polystyrene interphase determined by inverse gas chromatography

    Science.gov (United States)

    John Simonsen; Zhenqiu Hong; Timothy G. Rials

    1997-01-01

    The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inoranic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass...

  14. Effect of thermal modification on the physical properties of juvenile and mature woods of Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Fred Willians Calonego

    Full Text Available This study aimed to evaluate the effect of thermal treatment on the physical properties of juvenile and mature woods of Eucalyptus grandis. Boards were taken from 30-year-old E. grandis trees. The boards were thermally modified at 180 °C in the Laboratory of Wood Drying and Preservation at UNESP, Botucatu, Sao Paulo state, Brazil. The results showed that thermal modification caused: (1 decrease of 6.8% in the density at 0% equilibrium moisture content of mature wood; (2 significant decreases of 14.7% and 35.6% in the maximum volumetric swellings of juvenile and mature woods, respectively; (3 significant decreases of 13.7% and 21.3% in the equilibrium moisture content of juvenile and mature woods, respectively. The influence of thermal modification in juvenile wood was lower than in mature wood and caused greater uniformity in the physical variations between these types of wood in E. grandis.

  15. Radial variation of wood physical properties in Pinus patula growing in Mozambique

    Directory of Open Access Journals (Sweden)

    Claudio Gumane Francisco Juizo

    2015-09-01

    Full Text Available  This study aimed to evaluate wood physical properties of Pinus patula, aged 38, from a forest stand located in Machipanda, central region of Mozambique. Determination of physical properties, such as basic specific gravity, shrinkage, and moisture content of wood in the pith-bark followed the recommendations of the Panamerican Standard - COPANT. Results showed statistically significant differences at significance level of 5%, in the radial direction for the shrinkage coefficient in the pith-bark. Radial and tangential shrinkage values were 6.06 and 8.80% in juvenile wood and 6.18 and 8.65% in adult wood, respectively, with anisotropy coefficient of 1.43 for juvenile wood and 2.44 for adult wood. Pinus patula growing in Inhamacari forest shows stable wood at age 38. It can be used for structural purposes and for manufacture of joinery and furniture.

  16. Physical and mechanical properties of bio-composites from wood particles and liquefied wood resin

    Science.gov (United States)

    Hui Pan; Todd F. Shupe; Chung-Yun Hse

    2009-01-01

    Compression molded composites were made from wood particles and a liquefied wood/phenol/formaldehyde co-condensed resin. Based on our previous research, a phenol to wood (P/W) ratio of 2/1 was chosen for this study. The two experimental variables selected were: 1) liquefaction temperature (150o and 180oC) and 2) cooking method (atmospheric and sealed). Panels were...

  17. physico-chemical properties and energy potential of wood wastes

    African Journals Online (AJOL)

    user

    were performed to assess the energy characteristics of the collected wood .... Methods. Wood processing activities were physically observed for. 6 days/wk at the sawmills for 15weeks. ..... [10] Oladeji, J T “Fuel characterization of briquettes.

  18. Understanding extractive bleed : wood extractives: distribution, properties, and classes

    Science.gov (United States)

    Edward Burke; Norm Slavik; Tony Bonura; Dennis Connelly; Tom Faris; Arnie Nebelsick; Brent Stuart; Sam Williams; Alex C. Wiedenhoeft

    2010-01-01

    Color, odor, and natural durability of heartwood are characteristics imparted by a class of chemicals in wood known collectively extractives. Wood is converted by the tree from sapwood to heartwood by the deposition of extractives, typically many years after the growth ring undergoing this change was formed by the tree. Extractives are thus not a part of the wood...

  19. Trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus.

    Science.gov (United States)

    Hajek, Peter; Leuschner, Christoph; Hertel, Dietrich; Delzon, Sylvain; Schuldt, Bernhard

    2014-07-01

    Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plants of five demes (Populus tremula L. and Populus tremuloides Michx.) differing in growth rate, we tested the hypotheses that (i) demes differ in wood anatomical and hydraulic properties, (ii) hydraulic efficiency and safety are related to xylem anatomical traits, and (iii) aboveground productivity and hydraulic efficiency are negatively correlated to cavitation resistance. Significant deme differences existed in seven of the nine investigated branch-related anatomical and hydraulic traits but only in one of the four coarse-root-related anatomical traits; this likely is a consequence of high intra-plant variation in root morphology and the occurrence of a few 'high-conductivity roots'. Growth rate was positively related to branch hydraulic efficiency (xylem-specific conductivity) but not to cavitation resistance; this indicates that no marked trade-off exists between cavitation resistance and growth. Both branch hydraulic safety and hydraulic efficiency significantly depended on vessel size and were related to the genetic distance between the demes, while the xylem pressure causing 88% loss of hydraulic conductivity (P88 value) was more closely related to hydraulic efficiency than the commonly used P50 value. Deme-specific variation in the pit membrane structure may explain why vessel size was not directly linked to growth rate. We conclude that branch hydraulic efficiency is an important growth-influencing trait in aspen, while the assumed trade-off between productivity and hydraulic safety is weak. © The Author 2014. Published by Oxford University Press. All rights reserved

  20. Equivalent circuit modeling of the dielectric properties of rubber wood at low frequency

    Science.gov (United States)

    Wan M. Daud; Kaida B. Khalid; Aziz H.A. Sidek

    2000-01-01

    Dielectric properties of rubber wood were studied at various moisture contents and grain directions at low frequencies from 10-2 to 105 Hz. Results showed that the moisture content of wood affected the dielectric properties considerably. Dielectric data at different anisotropic directions, i.e., longitudinal, radial, and...

  1. Whole-tree bark and wood properties of loblolly pine from intensively managed plantations

    Science.gov (United States)

    Finto Antony; Laurence R. Schimleck; Richard F. Daniels; Alexander Clark; Bruce E. Borders; Michael B. Kane; Harold E. Burkhart

    2015-01-01

    A study was conducted to identify geographical variation in loblolly pine bark and wood properties at the whole-tree level and to quantify the responses in whole-tree bark and wood properties following contrasting silvicultural practices that included planting density, weed control, and fertilization. Trees were destructively sampled from both conventionally managed...

  2. Investigation of the Acoustic Properties of Chemically Impregnated Kayu Malam Wood Used for Musical Instrument

    Directory of Open Access Journals (Sweden)

    Md. Faruk Hossen

    2018-01-01

    Full Text Available The chemical modification or impregnation through preparing the wood polymer composites (WPCs can effectively reduce the hygroscopicity as well as can improve the acoustic properties of wood. On the other hand, a small amount of nanoclay into the chemical mixture can further improve the different properties of the WPCs through the preparation of wood polymer nanocomposites (WPNCs. Kayu Malam wood species with styrene (St, vinyl acetate (VA, and montmorillonite (MMT nanoclay were used for the preparation of WPNCs. The acoustic properties such as specific dynamic Young’s modulus (Ed/γ, internal friction (Q−1, and acoustic conversion efficiency (ACE of wood were examined using free-free flexural vibration. It was observed that the chemically impregnated wood composite showed a higher value of Ed/γ than raw wood and the nanoclay-loaded wood nanocomposite showed the highest value. The reverse trend was observed in the case of Q−1. On the other hand, chemical impregnation has a minor effect on ACE of wood for musical instruments. The results suggested that the chemically impregnated Kayu Malam wood polymer nanocomposite (WPNC is suitable for making soundboards of violin and guitar instruments to be played longer without losing tone quality.

  3. Properties of Hungarian oak(quercus conferta Kit. wood from the Hilandar Monastery forest

    Directory of Open Access Journals (Sweden)

    Popović Zdravko

    2007-01-01

    Full Text Available This paper presents the study results of the basic physical and strength properties of Hungarian oak (Quercus conferta Kit. wood from the Kakovo Monastery forests of Hilandar Monastery in Greece. Wood properties were analyzed in detail, as an indispensable proof of wood quality and its use for joinery, interiors and wooden floors. The basic physical properties of wood (moisture content at the time of tree felling, density and volume porosity and the basic strength properties (compressive strength, bending strength and module of elasticity were researched. The results are presented in Tables and in Diagrams with statistical parameters and compared to the literature data. The correlation of the study properties of wood was also analyzed.

  4. Relationship of vibro-mechanical properties and microstructure of wood and varnish interface in string instruments

    Science.gov (United States)

    Sedighi Gilani, Marjan; Pflaum, Johanna; Hartmann, Stefan; Kaufmann, Rolf; Baumgartner, Michael; Schwarze, Francis Willis Mathew Robert

    2016-04-01

    Wood varnish coatings not only are aesthetically important, but also preserve the musical instrument from wear and fluctuations in the ambient humidity. Depending on the thickness, extent of penetration into the wood and the physical and mechanical properties after hardening, varnishes may change the mechanical and also vibro-acoustical properties of the coated wood. Contrary to studies on the chemistry of the varnish and primer used for old and contemporary musical instruments, the physical and mechanical properties of the varnished wood in relation to the geometry of their interface have been poorly studied. We implemented non-destructive test methods, i.e., vibration tests and X-ray tomography, to characterize the hardening-dependent change in the vibrational properties of master grade tone wood specimens after coating with four different varnishes. Two were manufactured in the laboratory, and two were supplied from master violin makers. For a controlled accelerated hardening of the varnish, a UV exposure method was used. It was demonstrated that varnishes increase wood damping, along and perpendicular to the grain directions. Varnishes reduce the sound radiation along the grain, but increase it in the perpendicular direction. Changes in the vibrational properties were discussed together with results of 3D images of wood and varnish microstructure, obtained from a customized tabletop X-ray microtomographic setup. For comparison, the microstructure of the interface of the varnished wood in the laboratory and of specimens from two old violins was analyzed with the same X-ray tomography setup. Laboratory varnishes with various compositions penetrated differently into the wood structure. One varnish of a master grade old violin had a higher density and was also thicker and penetrated weaker into the wood, which is more likely related to a more sophisticated primer and varnish application. The study demonstrates the importance of the vibro-mechanical properties of

  5. Property improvement by gamma polymerization of methyl methacrylate impregnated local Thai wood Yang (Dipterocarpus Sp.)

    International Nuclear Information System (INIS)

    Saisomboon, S.; Sumitra, T.

    1990-01-01

    Property improvement of a local Thai wood (Yang-Dipterocarpus Sp.) was studied by impregnating with methyl methacrylate before polymerizing with gamma ray. The polymer loading were 126 and 68 percent for sapwood and heart wood, respectively. Significant improvements in impact, compressive and bending strength were observed in the wood polymer composite (WPC). In addition, the microstructure and the impact fractured-surfaces of WPC were also carried with a scanning electron-microscope

  6. Effect of boron compounds on the thermal and combustion properties of wood-plastic composites

    OpenAIRE

    Altuntaş, Ertuğrul; Karaoğul, Eyyup; Alma, Mehmet Hakkı

    2017-01-01

    In this study, the thermal properties and fire resistancesof the wood plastic composites produced with waste lignocellulosic materialswere investigated. For this purpose, lignocellulosic waste, high densitypolyethylene, (HDPE) sodium borate (borax) and boric acid was used to producethe wood-plastic composites. A twin-screw extruder was used during theproduction of the wood plastic composites. The produced composite granule waspressed at 175 °C hot press. The effects of boric acid and borax ad...

  7. CONCERNING THE ELASTIC ORTHOTROPIC MODEL APPLIED TO WOOD ELASTIC PROPERTIES

    OpenAIRE

    Tadeu Mascia,Nilson

    2003-01-01

    Among the construction materials, wood reveals an orthotropic pattern, because of unique characteristics in its internal structure with three axes of wood biological directions (longitudinal, tangential and radial). elastic symmetry: longitudinal, tangential and radial, reveals an orthotropic pattern. The effect of grain angle orientation onin the elastic modulus constitutes the fundamental cause forof wood anisotropy. It is responsible for the greatest changes in the values of the constituti...

  8. The effect of crosslinker on mechanical and morphological properties of tropical wood material composites

    International Nuclear Information System (INIS)

    Islam, Md. Saiful; Hamdan, Sinin; Rahman, Md. Rezaur; Jusoh, Ismail; Ahmed, Abu Saleh

    2011-01-01

    In this study, wood polymer composites (WPCs) based on five kinds of selected tropical wood species, namely Jelutong (Dyera costulata), Terbulan (Endospermum diadenum), Batai (Paraserianthes moluccana), Rubber (Hevea brasiliensis), and Pulai (Alstonia pneumatophora), were impregnated with methyl methacrylate (MMA) and hexamethylene diisocyanate (HMDIC) monomers mixture in the ratio of 1:1 for composite manufacturing. All these tropical wood reacted with hexamethylene diisocyanate and crosslinked with MMA which enhanced the hydrophobic (restrained water) nature of wood. The vacuum-pressure method was used to impregnate the samples with monomer mixture. The monomer mixture loading achievable was found to be dependent on the properties of wood species. Low loading was observed for the high density wood species. Mechanical strength of fabricated wood polymer composites (WPCs) in term of modulus of elasticity (MOE) and modulus of rupture (MOR) were found to be significantly improved. The wood-polymer interaction was confirmed by Fourier transform infrared (FTIR) spectroscopy. Morphological properties of raw wood and WPC samples were evaluated by scanning electron microscopy (SEM) and XRD analysis and an improvement in morphological properties was also observed for WPC.

  9. Effect of stacking sequence on mechanical properties neem wood veneer plastic composites

    Science.gov (United States)

    Nagamadhu, M.; Kumar, G. C. Mohan; Jeyaraj, P.

    2018-04-01

    This study investigates the effect of wood veneer stacking sequence on mechanical properties of neem wood polymer composite (WPC) experimentally. Wood laminated samples were fabricated by conventional hand layup technique in a mold and cured under pressure at room temperature and then post cured at elevated temperature. Initially, the tensile, flexural, and impact test were conducted to understand the effect of weight fraction of fiber on mechanical properties. The mechanical properties have increased with the weight fraction of fiber. Moreover the stacking sequence of neem wood plays an important role. As it has a significant impact on the mechanical properties. The results indicated that 0°/0° WPC shows highest mechanical properties as compared to other sequences (90°/90°, 0°/90°, 45°/90°, 45°/45°). The Fourier Transform Infrared Spectroscopy (FTIR) Analysis were carried out to identify chemical compounds both in raw neem wood and neem wood epoxy composite. The microstructure raw/neat neem wood and the interfacial bonding characteristics of neem wood composite investigated using Scanning electron microscopy images.

  10. Specific features of electrical properties of porous biocarbons prepared from beech wood and wood artificial fiberboards

    Science.gov (United States)

    Popov, V. V.; Orlova, T. S.; Magarino, E. Enrique; Bautista, M. A.; Martínez-Fernández, J.

    2011-02-01

    This paper reports on comparative investigations of the structural and electrical properties of biomorphic carbons prepared from natural beech wood, as well as medium-density and high-density fiberboards, by means of carbonization at different temperatures T carb in the range 650-1000°C. It has been demonstrated using X-ray diffraction analysis that biocarbons prepared from medium-density and high-density fiberboards at all temperatures T carb contain a nanocrystalline graphite component, namely, three-dimensional crystallites 11-14 Å in size. An increase in the carbonization temperature T carb to 1000°C leads to the appearance of a noticeable fraction of two-dimensional graphene particles with the same sizes. The temperature dependences of the electrical resistivity ρ of the biomorphic carbons have been measured and analyzed in the temperature range 1.8-300 K. For all types of carbons under investigation, an increase in the carbonization temperature T carb from 600 to 900°C leads to a change in the electrical resistivity at T = 300 K by five or six orders of magnitude. The dependences ρ( T) for these materials are adequately described by the Mott law for the variable-range hopping conduction. It has been revealed that the temperature dependence of the electrical resistivity exhibits a hysteresis, which has been attributed to thermomechanical stresses in an inhomogeneous structure of the biocarbon prepared at a low carbonization temperature T carb. The crossover to the conductivity characteristic of disordered metal systems is observed at T carb ≳ 1000°C.

  11. Thermal properties of wood reacted with a phosphorus pentoxide–amine system

    Science.gov (United States)

    Hong-Lin Lee; George C. Chen; Roger M. Rowell

    2004-01-01

    The objective of this research was to improve the fire-retardant properties of wood in one treatment using a phosphorus pentoxide–amine system. Phosphorus pentoxide and 16 amines including alkyl, halophenyl, and phenyl amines were compounded in N,N-dimethylformamide and the resulting solutions containing phosphoramides were reacted with wood. The characteristics of...

  12. Fundamental characteristics of microwave explosion pretreatment of wood. I, Properties of temperature development

    Science.gov (United States)

    Xian-jun Li; Ke-yang Lu; Lan-ying Lin; Yong-dong Zhou; Zhi-yong Cai; Feng Fu

    2010-01-01

    In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content (MC) on the properties of temperature development in Eucalyptus urophylla wood samples during the microwave explosion pretreatment have been investigated using a new microwave pretreatment equipment. The results show that 1) with the increase of microwave...

  13. The vibrational properties of Chinese fir wood during moisture sorption process

    Science.gov (United States)

    Jiali Jiang; Jianxiong Lu; Zhiyong Cai

    2012-01-01

    The vibrational properties of Chinese fir (Cunninghamia lanceolata) wood were investigated in this study as a function of changes in moisture content (MC) and grain direction. The dynamic modulus of elasticity (DMOE) and logarithmic decrement σ were examined using a cantilever beam vibration testing apparatus. It was observed that DMOE and 6 of wood vaned...

  14. Properties of flat-pressed wood plastic composites containing fire retardants

    Science.gov (United States)

    Nadir Ayrilmis; Jan. T. Benthien; Heiko Thoemen; Robert H. White

    2011-01-01

    This study investigated physical, mechanical, and fire properties of the flat-pressed wood plastic composites (WPCs) incorporated with various fire retardants (FRs) [5 or 15% by weight (wt)] at 50 wt % of the wood flour (WF). The WPC panels were made from dry-blended WF, polypropylene (PP) with maleic anhydride grafted PP (2 wt %), and FR powder formulations using a...

  15. The wood properties and sawn-board quality of South African-grown ...

    African Journals Online (AJOL)

    This report summarises results of past research in South Africa on the wood properties and qualities of P. maximinoi, supplemented by results of a study performed recently on an approximately 15.5-year-old provenance trial at Wilgeboom after it had been severely damaged by fire. The trees selected to study wood density, ...

  16. Mechanical properties of wood-based composite materials

    Science.gov (United States)

    Zhiyong Cai; Robert J. Ross

    2010-01-01

    The term composite is used to describe any wood material bonded together with adhesives. The current product mix ranges from fiberboard to laminated beams and components. In this chapter, wood-based composite materials are classified into the following categories: panel products (plywood, oriented strandboard (OSB), particleboard, fiberboard, medium-density fiberboard...

  17. An evaluation of wood properties of Pinus caribeae (Morelet) in ...

    African Journals Online (AJOL)

    This paper examines the effects of within tree variation on wood density, ring width and anisotropic shrinkage of Pinus caribeae (Morelet) among tree partitions in Oluwa pine plantation. Five 15-year old Pinus caribeae (Morelet) in three partitions were randomly selected from the plantation and felled for the study. Wood ...

  18. Changes in mechanical and chemical wood properties by electron beam irradiation

    International Nuclear Information System (INIS)

    Schnabel, Thomas; Huber, Hermann; Grünewald, Tilman A.; Petutschnigg, Alexander

    2015-01-01

    Highlights: • Changes in wood due to electron beam irradiations (EBI) were evaluated. • Wood components undergo different altering mechanisms due to the irradiation. • Chemical reactions in wood lead to better surface hardness of low irradiated wood. - Abstract: This study deals with the influence of various electron beam irradiation (EBI) dosages on the Brinell hardness of Norway spruce. The results of the hardness measurements and the FT-IR spectroscopic analysis show different effects of the EBI at dosages of 25, 50, 100 and 200 kGy. It was assumed that the lignin and carbohydrates undergo different altering mechanisms due to the EBI treatment. New cleavage products and condensation reactions of lignin and carbohydrates lead to better surface hardness of low irradiated wood samples. These results provide a useful basis for further investigations on the changes in wood chemistry and material properties due to electron beam irradiations

  19. Changes in mechanical and chemical wood properties by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schnabel, Thomas, E-mail: thomas.schnabel@fh-salzburg.ac.at [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); Huber, Hermann [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); Grünewald, Tilman A. [BOKU University of Natural Resources and Life Sciences, Institute of Physics and Materials Science, Peter Jordan Straße 82, 1190 Vienna (Austria); Petutschnigg, Alexander [Salzburg University of Applied Sciences, Department of Forest Products Technology and Wood Constructions, Marktstraße 136a, 5431 Kuchl (Austria); BOKU University of Natural Resources and Life Sciences, Konrad Lorenzstraße 24, 3430 Tulln (Austria)

    2015-03-30

    Highlights: • Changes in wood due to electron beam irradiations (EBI) were evaluated. • Wood components undergo different altering mechanisms due to the irradiation. • Chemical reactions in wood lead to better surface hardness of low irradiated wood. - Abstract: This study deals with the influence of various electron beam irradiation (EBI) dosages on the Brinell hardness of Norway spruce. The results of the hardness measurements and the FT-IR spectroscopic analysis show different effects of the EBI at dosages of 25, 50, 100 and 200 kGy. It was assumed that the lignin and carbohydrates undergo different altering mechanisms due to the EBI treatment. New cleavage products and condensation reactions of lignin and carbohydrates lead to better surface hardness of low irradiated wood samples. These results provide a useful basis for further investigations on the changes in wood chemistry and material properties due to electron beam irradiations.

  20. Preparation and Properties of Cassava Starch-based Wood Adhesives

    Directory of Open Access Journals (Sweden)

    Qing Xu

    2016-06-01

    Full Text Available A biodegradable, environmentally friendly starch-based wood adhesive with cassava starch as a raw material and butyl acrylate (BA as a co-monomer was synthesized. Results revealed that this cassava starch-based wood adhesive (SWA was more stable than corn starch-based wood adhesive, and its bonding performance was close to that of commercial PVAc emulsion, even after 90 days of storage. Further analysis found that the improved stability of the adhesive could be attributed to its low minimum film forming temperature (MFFT and glass transition temperature (Tg of cassava starch. Moreover, the amount of total volatile organic compounds (TVOCs emitted by the cassava starch-based wood adhesive were much lower than the Chinese national standard control criteria. Therefore, cassava SWA might be a potential alternative to traditional petrochemical-based wood adhesives.

  1. Characteristics of wood ash and influence on soil properties and nutrient uptake: an overview.

    Science.gov (United States)

    Demeyer, A; Voundi Nkana, J C; Verloo, M G

    2001-05-01

    Wood industries and power plants generate enormous quantities of wood ash. Disposal in landfills has been for long a common method for removal. New regulations for conserving the environment have raised the costs of landfill disposal and added to the difficulties for acquiring new sites for disposal. Over a few decades a number of studies have been carried out on the utilization of wood ashes in agriculture and forestry as an alternative method for disposal. Because of their properties and their influence on soil chemistry the utilization of wood ashes is particularly suited for the fertility management of tropical acid soils and forest soils. This review principally focuses on ash from the wood industry and power plants and considers its physical, chemical and mineralogical characteristics, its effect on soil properties, on the availability of nutrient elements and on the growth and chemical composition of crops and trees, as well as its impact on the environment.

  2. Compression and flexural properties of finger jointed mango wood sections

    OpenAIRE

    Kumar, V.S Kishan; Sharma, C.M; Gupta, Sachin

    2014-01-01

    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...

  3. Surface properties of thermally treated composite wood panels

    Science.gov (United States)

    Croitoru, Catalin; Spirchez, Cosmin; Lunguleasa, Aurel; Cristea, Daniel; Roata, Ionut Claudiu; Pop, Mihai Alin; Bedo, Tibor; Stanciu, Elena Manuela; Pascu, Alexandru

    2018-04-01

    Composite finger-jointed spruce and oak wood panels have been thermally treated under standard pressure and oxygen content conditions at two different temperatures, 180 °C and respectively 200 °C for short time periods (3 and 5 h). Due to the thermally-aided chemical restructuration of the wood components, a decrease in water uptake and volumetric swelling values with up to 45% for spruce and 35% for oak have been registered, comparing to the reference samples. In relation to water resistance, a 15% increase of the dispersive component of the surface energy has been registered for the thermal-treated spruce panels, which impedes water spreading on the surface. The thermal-treated wood presents superior resistance to accelerated UV exposure and subsequently, with up to 10% higher Brinell hardness values than reference wood. The proposed thermal treatment improves the durability of the finger-jointed wood through a more economically and environmental friendly method than traditional impregnation, with minimal degradative impact on the structural components of wood.

  4. Retrospective Analysis of Wood Anatomical Traits Reveals a Recent Extension in Tree Cambial Activity in Two High-Elevation Conifers.

    Science.gov (United States)

    Carrer, Marco; Castagneri, Daniele; Prendin, Angela L; Petit, Giai; von Arx, Georg

    2017-01-01

    The study of xylogenesis or wood formation is a powerful, yet labor intensive monitoring approach to investigate intra-annual tree growth responses to environmental factors. However, it seldom covers more than a few growing seasons, so is in contrast to the much longer lifespan of woody plants and the time scale of many environmental processes. Here we applied a novel retrospective approach to test the long-term (1926-2012) consistency in the timing of onset and ending of cambial activity, and in the maximum cambial cell division rate in two conifer species, European larch and Norway spruce at high-elevation in the Alps. We correlated daily temperature with time series of cell number and lumen area partitioned into intra-annual sectors. For both species, we found a good correspondence (1-10 days offset) between the periods when anatomical traits had significant correlations with temperature in recent decades (1969-2012) and available xylogenesis data (1996-2005), previously collected at the same site. Yet, results for the 1926-1968 period indicate a later onset and earlier ending of the cambial activity by 6-30 days. Conversely, the peak in the correlation between annual cell number and temperature, which should correspond to the peak in secondary growth rate, was quite stable over time, with just a minor advance of 4-5 days in the recent decades. Our analyses on time series of wood anatomical traits proved useful to infer on past long-term changes in xylogenetic phases. Combined with intensive continuous monitoring, our approach will improve the understanding of tree responses to climate variability in both the short- and long-term context.

  5. Retrospective Analysis of Wood Anatomical Traits Reveals a Recent Extension in Tree Cambial Activity in Two High-Elevation Conifers

    Directory of Open Access Journals (Sweden)

    Marco Carrer

    2017-05-01

    Full Text Available The study of xylogenesis or wood formation is a powerful, yet labor intensive monitoring approach to investigate intra-annual tree growth responses to environmental factors. However, it seldom covers more than a few growing seasons, so is in contrast to the much longer lifespan of woody plants and the time scale of many environmental processes. Here we applied a novel retrospective approach to test the long-term (1926–2012 consistency in the timing of onset and ending of cambial activity, and in the maximum cambial cell division rate in two conifer species, European larch and Norway spruce at high-elevation in the Alps. We correlated daily temperature with time series of cell number and lumen area partitioned into intra-annual sectors. For both species, we found a good correspondence (1–10 days offset between the periods when anatomical traits had significant correlations with temperature in recent decades (1969–2012 and available xylogenesis data (1996–2005, previously collected at the same site. Yet, results for the 1926–1968 period indicate a later onset and earlier ending of the cambial activity by 6–30 days. Conversely, the peak in the correlation between annual cell number and temperature, which should correspond to the peak in secondary growth rate, was quite stable over time, with just a minor advance of 4–5 days in the recent decades. Our analyses on time series of wood anatomical traits proved useful to infer on past long-term changes in xylogenetic phases. Combined with intensive continuous monitoring, our approach will improve the understanding of tree responses to climate variability in both the short- and long-term context.

  6. Effect of wood flour content on the optical color, surface chemistry, mechanical and morphological properties of wood flour/recycled high density polyethylene (rHDPE) composite

    Science.gov (United States)

    Sheng, Chan Kok; Amin, Khairul Anuar Mat; Kee, Kwa Bee; Hassan, Mohd Faiz; Ali, E. Ghapur E.

    2018-05-01

    In this study, effect of wood flour content on the color, surface chemistry, mechanical properties and surface morphology of wood-plastic composite (WPC) on different mixture ratios of recycled high density polyethylene (rHDPE) and wood flour were investigated in detail. The presence of wood flour in the composite indicates a significant total color change and a decrease of lightness. Functional groups of wood flour in WPC can be seen clearer from the Fourier transform infrared (FTIR) spectra as the wood flour content increases. The mechanical tensile testing shows that the tensile strength of Young's modulus is improved, whereas the strain and elongation at break were reduced by the addition of wood flour. The gap between the wood flour microvoid fibre and rHDPE matrix becomes closer when the wood flour content is increased as observed by scanning electron microscope (SEM) image. This finding implies a significant improvement on the interaction of interfacial adhesion between the rHDPE matrix and wood flour filler in the present WPC.

  7. ANATOMICAL PROPERTIES AND FIBER QUALITY OF FIVE POTENTIAL COMMERCIAL WOOD SPECIES FROM CIANJUR, WEST JAVA

    Directory of Open Access Journals (Sweden)

    Ratih Damayanti

    2010-06-01

    Full Text Available A detailed description of wood anatomy is essential for assessing the use of a wood species for processing , and also beneficial for the identification of wood samples. Computerized keys are available that allow the identification of wood samples until the genus level; however, it is not easy to use these keys to identif y unknown species. Therefore, a database of anatomical characteristics and the computerized keys need to be completed up to species level. As the relevance, this study has examined the wood anatomical properties of the five corresponding tree species originated from Cianjur, West Java, which are commercially potential for their exploitation, i.e Castanopsis acuminatissima ADC. (Fagaceae; Castanopsistungurrut ADC. (Fagaceae; Cinnamomum inners Reinw. ex Blume (Lauraceae; Ficus nervosa Heyne (Moraceae and Horsfieldia glabra Warb. (Myristicaceae. Expectedly the results would be beneficial for wood identification purposes and evaluation for other possible uses. Obser vations on anatomical structures covered macroscopic and microscopic characteristics were carried out through the sectioned and macerated wood samples. The obser ved characteristics of the anatomical features were defined conforming to the IAWA List of Microscopic Features for Hardwood  Identification.  Based on the scrutiny on those obser ved characteristics and linked to the fiber quality, it was judged that the fiber in all the five wood species could be classified as class I for pulp and paper processing.

  8. Genetic architecture of wood properties based on association analysis and co-expression networks in white spruce.

    Science.gov (United States)

    Lamara, Mebarek; Raherison, Elie; Lenz, Patrick; Beaulieu, Jean; Bousquet, Jean; MacKay, John

    2016-04-01

    Association studies are widely utilized to analyze complex traits but their ability to disclose genetic architectures is often limited by statistical constraints, and functional insights are usually minimal in nonmodel organisms like forest trees. We developed an approach to integrate association mapping results with co-expression networks. We tested single nucleotide polymorphisms (SNPs) in 2652 candidate genes for statistical associations with wood density, stiffness, microfibril angle and ring width in a population of 1694 white spruce trees (Picea glauca). Associations mapping identified 229-292 genes per wood trait using a statistical significance level of P wood associated genes and several known MYB and NAC regulators were identified as network hubs. The network revealed a link between the gene PgNAC8, wood stiffness and microfibril angle, as well as considerable within-season variation for both genetic control of wood traits and gene expression. Trait associations were distributed throughout the network suggesting complex interactions and pleiotropic effects. Our findings indicate that integration of association mapping and co-expression networks enhances our understanding of complex wood traits. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  9. Pectin Methylesterase Genes Influence Solid Wood Properties of Eucalyptus pilularis1[C][W][OA

    Science.gov (United States)

    Sexton, Timothy R.; Henry, Robert J.; Harwood, Chris E.; Thomas, Dane S.; McManus, Luke J.; Raymond, Carolyn; Henson, Michael; Shepherd, Mervyn

    2012-01-01

    This association study of Eucalyptus pilularis populations provides empirical evidence for the role of Pectin Methylesterase (PME) in influencing solid wood characteristics of Eucalyptus. PME6 was primarily associated with the shrinkage and collapse of drying timber, which are phenotypic traits consistent with the role of pectin as a hydrophilic polysaccharide. PME7 was primarily associated with cellulose and pulp yield traits and had an inverse correlation with lignin content. Selection of specific alleles in these genes may be important for improving trees as sources of high-quality wood products. A heterozygote advantage was postulated for the PME7 loci and, in combination with haplotype blocks, may explain the absence of a homozygous class at all single-nucleotide polymorphisms investigated in this gene. PMID:22052017

  10. Properties of Eucalyptus benthamii wood for energy production

    Directory of Open Access Journals (Sweden)

    Dimas Agostinho Silva

    2015-12-01

    Full Text Available The objective of this study was to evaluate the energy potential of Eucalyptus benthamii Maiden et Cambage wood. The samples were collected in the municipality of Cerro Negro, Santa Catarina State, Brazil. Samples were collected from 5 trees at 0%, 25%, 50%, 75% and 100% of commercial height. It was determined basic density, high calorific value, elemental composition, immediate chemical analysis, lower calorific value, energy density, carbon storage and energy production. The physical and chemical variables studied and energy potential of wood did not present differences along the stem.

  11. Advances in the study of mechanical properties and constitutive law in the field of wood research

    Science.gov (United States)

    Zhao, S.; Zhao, J. X.; Han, G. Z.

    2016-07-01

    This paper presents an overview of mechanical properties and constitutive law for wood. Current research on the mechanical properties of wood have mostly focused on density, grain, moisture, and other natural factors. It has been established that high density, dense grain, and high moisture lead to higher strength. In most literature, wood has been regarded as an anisotropic material because of its fiber. A microscopic view is used in research of wood today, in this way, which has allowed for clear observation of anisotropy. In general, wood has higher strength under a dynamic load, and no densification. The constitutive model is the basis of numerical analysis. An anisotropic model of porous and composite materials has been used for wood, but results were poor, and new constitutions have been introduced. According to the literature, there is no single theory that is widely accepted for the dynamic load. Research has shown that grain and moisture are key factors in wood strength, but there has not been enough study on dynamic loads so far. Hill law has been the most common method of simulation. Models that consider high strain rate are attracting more and more attention.

  12. In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal, mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Devi, Rashmi R; Maji, Tarun K., E-mail: tkm@tezu.ernet.in [Department of Chemical Sciences, Tezpur University, Assam, (India)

    2013-11-01

    This study concerns the preparation and characterization of wood polymer nanocomposites based on impregnation of styrene acrylonitrile co-polymer-nanoclay intercalating system in presence of glycidyl methacrylate (GMA), a cross linking agent, and vinyl trichloro silane (VTCS) as additives into Simul (Bombex ceiba, L.), a soft wood. The effect of nanoclay and VTCS on the properties of the resultant wood polymer nanocomposites (WPNC) has been evaluated. FTIR spectroscopy shows the interaction among wood, polymers, GMA, nanoclay and VTCS. The penetration of polymer and nanoclay into the wood cell wall is supported by SEM study. The distribution of nanoclay in the SAN polymer matrix present within the wood cell wall has been evidenced by TEM study. TGA results show an improvement in the thermostability of the resultant composites. The inclusion of VTCS enhances the self extinguishing behaviour of the WPNC as revealed by limiting oxygen index (LOI) test. Due to treatment, the resultant WPNC exhibits an improvement in all the properties like water repellency, dimensional stability, hardness, flexural, tensile and thermal stability compared to untreated wood. (author)

  13. Technological and Thermal Properties of Thermoplastic Composites Filled with Heat-treated Alder Wood

    Directory of Open Access Journals (Sweden)

    Mürşit Tufan

    2016-02-01

    Full Text Available This study investigated the effect of heat-treated wood content on the water absorption, mechanical, and thermal properties of wood plastic composites (WPCs. The WPCs were produced from various loadings (30, 40, and 50 wt% of heat-treated and untreated alder wood flours (Alnus glutinosa L. using high-density polyethylene (HDPE with 3 wt% maleated polyethylene (MAPE coupling agent. All WPC formulations were compression molded into a hot press for 3 min at 170 ºC. The WPCs were evaluated using mechanical testing, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, and differential scanning calorimetry (DSC. The mechanical property values of the WPC specimens decreased with increasing amounts of the heat-treated wood flour, except for the tensile modulus values. The heat treatment of alder wood slightly increased the thermal stability of the WPCs compared with the reference WPCs. The crystallization degree (Xc and the enthalpy of crystallization of the WPCs slightly decreased with increasing content of the heat-treated wood flour. However, all WPCs containing the heat-treated alder wood flour showed a higher crystallinity degree than that of the virgin HDPE.

  14. In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal, mechanical properties

    International Nuclear Information System (INIS)

    Devi, Rashmi R; Maji, Tarun K.

    2013-01-01

    This study concerns the preparation and characterization of wood polymer nanocomposites based on impregnation of styrene acrylonitrile co-polymer–nanoclay intercalating system in presence of glycidyl methacrylate (GMA), a cross linking agent, and vinyl trichloro silane (VTCS) as additives into Simul (Bombex ceiba, L.), a soft wood. The effect of nanoclay and VTCS on the properties of the resultant wood polymer nanocomposites (WPNC) has been evaluated. FTIR spectroscopy shows the interaction among wood, polymers, GMA, nanoclay and VTCS. The penetration of polymer and nanoclay into the wood cell wall is supported by SEM study. The distribution of nanoclay in the SAN polymer matrix present within the wood cell wall has been evidenced by TEM study. TGA results show an improvement in the thermostability of the resultant composites. The inclusion of VTCS enhances the self extinguishing behaviour of the WPNC as revealed by limiting oxygen index (LOI) test. Due to treatment, the resultant WPNC exhibits an improvement in all the properties like water repellency, dimensional stability, hardness, flexural, tensile and thermal stability compared to untreated wood. (author)

  15. Flexural properties of four fast-growing eucalypts woods deteriorated by three different field tests

    Directory of Open Access Journals (Sweden)

    Rafael de Avila Delucis

    2017-02-01

    Full Text Available Durability is a wood characteristic determined by several factors, making it difficult to investigate the service life of pieces designated for outdoor use. In this study, the decaying of juvenile and adult woods of four fast-growing eucalypts from southern Brazil subjected to three different exposure environments was monitored through mechanical properties (flexural test. The study material was obtained from adult trees of Eucalyptus botryoides, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus tereticornis. Field tests were conducted in the city of Piratini, southern Brazil, and samplings were carried out during 540 days of experiment. Comparing the four eucalypts, the decreasing order of biological resistance was: Eucalyptus tereticornis, Corymbia citriodora, Eucalyptus paniculata and Eucalyptus botryoides. The mature wood showed greater and more stable physical-mechanical properties than juvenile wood.

  16. How do drought and warming influence survival and wood traits of Picea mariana saplings?

    Science.gov (United States)

    Balducci, Lorena; Deslauriers, Annie; Giovannelli, Alessio; Beaulieu, Marilène; Delzon, Sylvain; Rossi, Sergio; Rathgeber, Cyrille B K

    2015-01-01

    Warming and drought will occur with increased frequency and intensity at high latitudes in the future. How heat and water stress can influence tree mortality is incompletely understood. The aim of this study was to evaluate how carbon resources, stem hydraulics, and wood anatomy and density determine the ability of black spruce saplings to survive daytime or night-time warming (+ 6 °C in comparison with control) in combination with a drought period. Plant water relations, the dynamics of non-structural carbohydrates and starch, mortality rate, and wood anatomy and density of saplings were monitored. Warming, in conjunction with 25 d of water deficit, increased sapling mortality (10% and 20% in night-time and daytime warming, respectively) compared with the control conditions (0.8%). Drought substantially decreased gas exchange, and also pre-dawn and mid-day leaf water potential to values close to -3MPa which probably induced xylem embolism (xylem air entry point, P₁₂, being on average around -3MPa for this species). In addition, the recovery of gas exchange never reached the initial pre-stress levels, suggesting a possible loss of xylem hydraulic conductivity associated with cavitation. Consequently, mortality may be due to xylem hydraulic failure. Warmer temperatures limited the replenishment of starch reserves after their seasonal minimum. Lighter wood was formed during the drought period, reflecting a lower carbon allocation to cell wall formation, preventing the adaptation of the hydraulic system to drought. Saplings of black spruce experienced difficulty in adapting under climate change conditions, which might compromise their survival in the future. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. Chapter 8: Soy Properties and Soy Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart; Michael J. Birkeland

    2014-01-01

    Soy flour has been used for many years as a wood adhesive. Rapid development of petroleum-based infrastructure coupled with advancement of synthetic resin technology resulted in waning usage since the early 1960s. Discovery of using polyamidoamine–epichlorohydrin (PAE) resin as a co-reactant has been effective in increasing the wet bond strength of soy adhesives and...

  18. Rapid Assessment Of The Fundamental Property Variation Of Wood

    Science.gov (United States)

    Chi-Leung So; Leslie H. Groom; Timothy G. Rials; Rebecca Snell; Stephen S. Kelley; Robert Meglen

    2002-01-01

    Abstract - Genetic variation, site conditions, silvicultural treatments, seasonal effects, and their complex interaction are all vitally-important factors accounting for the variability and quality of the raw material produced - wood. Quality can be measured in several ways that generally influence the end use. The most desirable measure is the...

  19. Wood anatomy and physical and chemical properties of fast growing Athel tamarisk (Tamarix aphylla L.

    Directory of Open Access Journals (Sweden)

    Reza oladi

    2017-02-01

    Full Text Available Athel tamarisk (Tamarix aphylla is a fast growing, evergreen tree succeeding in the most soils and can tolerate the saline conditions. Despite its ecological importance and wide distribution in central and southern parts of Iran, wood properties of this species has little been concerned. However, the potential of this species in cellulosic industries of Middle East dry countries has recently been focused. Hence, to study wood anatomy and physical and chemical properties of Athel tamarisk, 3 stands were selected and felled from the Zabol region (Sistan and Baluchestan province. Wood anatomical features of this species were studied and listed according to the list of microscopic features for hardwood identification by IAWA Committee. In addition, lignin distribution in xylem was studied using fluorescence microscopy. Calculating fiber biometry features assessed that although fiber quality is not perfect but meets the standards of paper production, comparing other commercially used hardwoods in this industry. According to chemical composition analysis, cellulose content of this wood is rather low (39% which could be a result of large amount of thin-walled paranchyma cells in xylem. Lignin content is a bit higher than average hardwoods and this component is concentrated in vessels and fibers. Physical properties of studied wood samples (specific gravity and shrinkage values were in the range of other light-weight and fast growing hardwoods and thus this wood is expected to have similar end-use quality.

  20. Evaluation of the physical, mechanical and biological properties of the combined wood-plastic in Nothofagus Pumilio wood

    International Nuclear Information System (INIS)

    Benedetto Acuna, Andres

    2010-01-01

    In this project he studied the physical, mechanical and biological properties of wood-plastic combinations (WPC) in timber Nothofagus pumilio (Lenga) impregnated with the monomer methyl methacrylate (MMA), trying to get a hold and maximum penetration into the wood . It was used for impregnation method fills the cell (Bethell). To achieve the polymerization, the MMA once absorbed by the specimens under study are irradiated with gamma rays at a dose of 25 kGy, ensuring a high percentage of final polymerization, which fluctuated between 55.09% and 84.48%. The tests applied to the specimens were moisture content, dimensional stability, density, compression perpendicular to grain, compression parallel to grain to grain compression 'new' Janka hardness, shear parallel to grain, static bending and termites. In general, except for the static bending test, the WPC had an increase in their property, being the tests of hardness, density and water absorption which achieved higher profits, increasing their properties at 104%, 79% and 75% respectively compared to untreated specimens. From the economic viewpoint, the production of an inch Lenga timber has a cost of $ 19,805, so it may be feasible marketing both domestically and internationally (author)

  1. Effects of different durations of acid hydrolysis on the properties of starch-based wood adhesive.

    Science.gov (United States)

    Wang, Yajie; Xiong, Hanguo; Wang, Zhenjiong; Zia-Ud-Din; Chen, Lei

    2017-10-01

    In this study, the effect of different durations of acid hydrolysis on the improvement of the properties of starch-based wood adhesive was investigated through a variety of determination methods The improved properties were analyzed using the pasting properties, viscosity, shear performance in dry and wet states, fourier infrared spectrometer, dynamic time sweep, and low filed nuclear magnetic resonance spectroscopy. Starch hydrolysis improved the viscosity stability, bonding performance, and water resistance of the starch-based wood adhesive. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Study of influence of 2.4 GHz electromagnetic waves on electrophysical properties of coniferous trees wood

    Science.gov (United States)

    Abdurahimov, Nursulton; Lagunov, Alexey; Melehov, Vladimir

    2017-09-01

    Climate change has a significant impact on changing weather conditions in the Arctic. Wood is a traditional building material in the North of Russia. Supports of communication lines are made of wood. Dry wood is a solid dielectric with a low conductivity. At the same time it is porous material having high hygroscopicity. The presence of moisture leads to wood rotting. To prevent rotting of a support it needs to be impregnated with antiseptics. A tree dried by means of convection drying cannot provide required porosity of wood for impregnation. Our studies of electrophysical properties of coniferous species showed that microwave drying of wood increases the porosity of the wood. Wood dried in this way is easily impregnated with antiseptics. Thorough wood drying requires creating optimal conditions in a microwave oven. During the drying process in a chamber there is a resonant phenomenon. These phenomena depend on electro-physical properties of the material placed in the chamber. Dielectric constant of wood has the most influence. A resonator method to determine the dielectric constant of the wood was used. The values of permittivity for the spruce and pine samples were determined. The measured value of the dielectric constant of wood was used to provide optimal matching of the generator with the resonator in a wood-drying resonator type microwave chamber, and to maintain it in the process of wood drying. It resulted in obtaining the samples with a higher permeability of wood in radial and longitudinal direction. This creates favorable conditions for wood impregnation with antiseptics and flame retardants. Timber dried by means of electromagnetic waves in the 2.4 GHz band has a deeper protective layer. The support made of such wood will serve longer as supports of communication lines.

  3. Justification of the Production Process of Pressed Wood and Study of its Properties

    Science.gov (United States)

    Polilov, A. N.; Dornyak, O. R.; Shamaev, V. A.; Rumachik, M. M.

    2018-05-01

    Results of a numerical analysis of the stress-strain state of wood during its pressing in different symmetry directions of the anisotropic material are presented. It is shown that the anisotropy of mechanical properties of wood is an important factor determining both the structural characteristics of the porous system and its strength. A mathematical modeling of the process of pressing wood as a three-phase anisotropic rheologically complex capillary-porous system allows one to predict parameters of the resulting wood composite. The compressed wood obtained by the production modes developed has a tensile strength eight times greater than that of the natural one, which is comparable to the strength of the St3 steel, but its specific strength is higher than that of the St45 steel. Compression and impregnation of softwood species with an aqueous solution of carbamide allows one to harden them. This kind of treatment endows the wood with enhanced strength characteristics comparable to the characteristics of the St3 steel. The special features of tensile tests used to estimate the elastic modulus and strength characteristics of such materials are considered. Data obtained by different testing methods are correlated, and characteristics of the strengthened wood and some brends of steel are compared.

  4. Preparation of wood-like structured copper with superhydrophobic properties

    Science.gov (United States)

    Wang, Tianchi; Liu, Guiju; Kong, Jian

    2015-12-01

    Here, we report a method to use natural wood lauan as a template to fabricate superhydrophobic biomorphic copper on a carbon substrate (Cu/C). First, a carbon substrate with the microstructure of lauan was obtained by sintering lauan in an oxygen-free environment. A biomorphic Cu/C material was then obtained by immersing this carbon substrate into a Cu(NO3)2 solution and sintering. Finally, the hydrophobicity of the products obtained was investigated. The Cu/C retained the microstructure of the wood well. It exhibited excellent superhydrophobicity after it was modified with fluorine silane. The water contact angle of this modified Cu/C reached 160°.

  5. Nest sanitation through defecation: antifungal properties of wood cockroach feces

    Science.gov (United States)

    Rosengaus, Rebeca B.; Mead, Kerry; Du Comb, William S.; Benson, Ryan W.; Godoy, Veronica G.

    2013-11-01

    The wood cockroach Cryptocercus punctulatus nests as family units inside decayed wood, a substrate known for its high microbial load. We tested the hypothesis that defecation within their nests, a common occurrence in this species, reduces the probability of fungal development. Conidia of the entomopathogenic fungus, Metarhizium anisopliae, were incubated with crushed feces and subsequently plated on potato dextrose agar. Relative to controls, the viability of fungal conidia was significantly reduced following incubation with feces and was negatively correlated with incubation time. Although the cockroach's hindgut contained abundant β-1,3-glucanase activity, its feces had no detectable enzymatic function. Hence, these enzymes are unlikely the source of the fungistasis. Instead, the antifungal compound(s) of the feces involved heat-sensitive factor(s) of potential microbial origin. When feces were boiled or when they were subjected to ultraviolet radiation and subsequently incubated with conidia, viability was "rescued" and germination rates were similar to those of controls. Filtration experiments indicate that the fungistatic activity of feces results from chemical interference. Because Cryptocercidae cockroaches have been considered appropriate models to make inferences about the factors fostering the evolution of termite sociality, we suggest that nesting in microbe-rich environments likely selected for the coupling of intranest defecation and feces fungistasis in the common ancestor of wood cockroaches and termites. This might in turn have served as a preadaptation that prevented mycosis as these phylogenetically related taxa diverged and evolved respectively into subsocial and eusocial organizations.

  6. Wood handbook : wood as an engineering material

    Science.gov (United States)

    Robert J. Ross; Forest Products Laboratory. USDA Forest Service.

    2010-01-01

    Summarizes information on wood as an engineering material. Presents properties of wood and wood-based products of particular concern to the architect and engineer. Includes discussion of designing with wood and wood-based products along with some pertinent uses.

  7. Enhanced Mechanical Properties of Poplar Wood by a Combined-Hydro-Thermo-Mechanical (CHTM) Modification

    OpenAIRE

    Houri Sharifnia; Behbood Mohebbi

    2011-01-01

    The current research explains an innovated technique to enhanced mechanice properties of poplar wood by combination of two modification techniques, hydrothermal and mechanical. Blocks of 50×55×500mm3 were cut from poplar wood and treated in a reactor at 120, 150 and 180°C for 30 min. Afterwards, the blocks were pressed at 180°C for 20 min at a pressure of 80 bar to achieve a compression set of 60% in radial direction. Density and bending properties (moduli of elasticity and rupture) as well a...

  8. Relating wood properties to handsheet porosity and mechanical strength

    CSIR Research Space (South Africa)

    Maharaj, S

    2006-11-01

    Full Text Available , 4041 3CSIR, Forestry and Forest Products Research Centre, P.O. Box 17001, Congella, 4013 WOOD HAND-SHEET (STRENGTH) PROCESSING Anatomy Chemistry Density Tear Tensile Burst Background Variation in pulp mills •Need to predict quality of end... important concepts… Some important concepts… • Collapsibility and inter-fibre bonding Light Microscopy SEM • Tear – Fibre level: pull-out vs. breaking/rupture Some important concepts… •Fibre breakage / rupture: less energy = lower tear strength...

  9. Ionic liquids influence on the surface properties of electron beam irradiated wood

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Product Design and Environment Department, 29 Eroilor Str., 500036, Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design and Environment Department, 29 Eroilor Str., 500036, Brasov (Romania); Doroftei, Florica; Parparita, Elena; Vasile, Cornelia [“Petru Poni” Institute of Macromolecular Chemistry, Physical Chemistry of Polymers Department, 41A Gr. Ghica Voda Alley, Iasi (Romania)

    2014-09-30

    Highlights: • Wood veneers impregnated with three imidazolium-based ionic liquids and irradiated with electron beam were studied by FTIR-ATR, SEM/EDX, AFM, contact angle and image analysis. • ILs preserve the surface properties of the wood (surface energy, roughness, color) upon irradiation, in comparison with the reference wood, but the surface composition is changed by treatment with IL-s, mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. • Under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface. - Abstract: In this paper, the influence of three imidazolium-based ionic liquids (1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-hexyl-3-methylimidazolium chloride) on the structure and surface properties of sycamore maple (Acer pseudoplatanus) veneers submitted to electron beam irradiation with a dose of 50 kGy has been studied by using Fourier transform infrared spectroscopy, as well as image, scanning electron microscopy/SEM/EDX, atomic force microscopy and contact angle analysis. The experimental results have proven that the studied ionic liquids determine a better preservation of the structural features of wood (cellulose crystallinity index and lignin concentration on the surface) as well as some of surface properties such as surface energy, roughness, color upon irradiation with electron beam, in comparison with the reference wood, but surface composition is changed by treatment with imidazolium-based ionic liquids mainly with 1-butyl-3-methylimidazolium tetrafluoroborate. Also, under electron beam irradiation covalent bonding of the imidazolium moiety to wood determines a higher resistance to water penetration and spreading on the surface.

  10. Elastic and Strength Properties of Heat-Treated Beech and Birch Wood

    Directory of Open Access Journals (Sweden)

    Vlastimil Borůvka

    2018-04-01

    Full Text Available This paper deals with the impact of heat treatment on the elastic and strength properties of two diffuse porous hardwoods, namely Fagus sylvatica and Betula pendula. Two degrees of the heat treatment were used at temperatures of 165 °C and 210 °C. The dynamic and static elasticity modulus, bending strength, impact toughness, hardness, and density were tested. It is already known that an increase in treatment temperature decreases the mechanical properties and, on the other hand, leads to a better shape and dimensional stability. Higher temperatures of the heat treatment correlated with lower elastic and strength properties. In the case of higher temperature treatments, the decline of tested properties was noticeable as a result of serious changes in the chemical composition of wood. It was confirmed that at higher temperature stages of treatment, there was a more pronounced decrease in beech properties compared to those of the birch, which was the most evident in their bending strength and hardness. Our research confirmed that there is no reason to consider birch wood to be of a lesser quality, although it is regarded by foresters as an inferior tree species. After the heat treatment, the wood properties are almost the same as in the case of beech wood.

  11. Using community trait-distributions to assign microbial responses to pH changes and Cd in forest soils treated with wood ash

    DEFF Research Database (Denmark)

    Cruz Paredes, Carla; Wallander, Håkan; Kjøller, Rasmus

    2017-01-01

    is the current land-use. In forestry, wood ash has been proposed as a liming agent and a fertilizer, but has been questioned due to the risk associated with its Cd content. The aim of this study was to determine the effects of wood ash on the structure and function of decomposer microbial communities in forest......The identification of causal links between microbial community structure and ecosystem functions are required for a mechanistic understanding of ecosystem responses to environmental change. One of the most influential factors affecting plants and microbial communities in soil in managed ecosystems...... soils and to assign them to causal mechanisms. To do this, we assessed the responses to wood ash application of (i) the microbial community size and structure, (ii) microbial community trait-distributions, including bacterial pH relationships and Cd-tolerance, to assign the microbial responses to p...

  12. Woods with physical, mechanical and acoustic properties similar to those of Caesalpinia echinata have high potential as alternative woods for bow makers

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz Longui

    2014-09-01

    Full Text Available For nearly two hundred years, Caesalpinia echinata wood has been the standard for modern bows. However, the threat of extinction and the enforcement of trade bans have required bow makers to seek alternative woods. The hypothesis tested was that woods with physical, mechanical and acoustic properties similar to those of C. echinata would have high potential as alternative woods for bows. Accordingly, were investigated Handroanthus spp., Mezilaurus itauba, Hymenaea spp., Dipteryx spp., Diplotropis spp. and Astronium lecointei. Handroanthus and Diplotropis have the greatest number of similarities with C. echinata, but only Handroanthus spp. showed significant results in actual bow manufacture, suggesting the importance of such key properties as specific gravity, speed of sound propagation and modulus of elasticity. In practice, Handroanthus and Dipteryx produced bows of quality similar to that of C. echinata.

  13. WGDB: Wood Gene Database with search interface.

    Science.gov (United States)

    Goyal, Neha; Ginwal, H S

    2014-01-01

    Wood quality can be defined in terms of particular end use with the involvement of several traits. Over the last fifteen years researchers have assessed the wood quality traits in forest trees. The wood quality was categorized as: cell wall biochemical traits, fibre properties include the microfibril angle, density and stiffness in loblolly pine [1]. The user friendly and an open-access database has been developed named Wood Gene Database (WGDB) for describing the wood genes along the information of protein and published research articles. It contains 720 wood genes from species namely Pinus, Deodar, fast growing trees namely Poplar, Eucalyptus. WGDB designed to encompass the majority of publicly accessible genes codes for cellulose, hemicellulose and lignin in tree species which are responsive to wood formation and quality. It is an interactive platform for collecting, managing and searching the specific wood genes; it also enables the data mining relate to the genomic information specifically in Arabidopsis thaliana, Populus trichocarpa, Eucalyptus grandis, Pinus taeda, Pinus radiata, Cedrus deodara, Cedrus atlantica. For user convenience, this database is cross linked with public databases namely NCBI, EMBL & Dendrome with the search engine Google for making it more informative and provides bioinformatics tools named BLAST,COBALT. The database is freely available on www.wgdb.in.

  14. Change of mechanical properties of Norway Spruce wood due to degradation caused by fire retardants

    Czech Academy of Sciences Publication Activity Database

    Kloiber, Michal; Frankl, Jiří; Drdácký, Miloš; Kučerová, I.; Tippner, J.; Bryscejn, Jan

    2010-01-01

    Roč. 55, č. 4 (2010), s. 23-38 ISSN 1336-4561 Grant - others:GAČR(CZ) GA103/07/1091 Program:GA Institutional research plan: CEZ:AV0Z20710524 Keywords : wood degradation * fire retardant * mechanical properties * tensile strength * hardness Subject RIV: JN - Civil Engineering Impact factor: 0.284, year: 2010

  15. Effects of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) wood

    Science.gov (United States)

    Xianjun Li; Zhiyong Cai; Qunying Mou; Yiqiang Wu; Yuan Liu

    2011-01-01

    In this study the effect of heat treatment on some physical properties of Douglas fir (Pseudotsuga menziesii) was investigated. Wood specimens were subjected to heat treatment at 160, 180, 200 and 220°C for 1, 2, 3 and 4h. The results show that heat treatment resulted in a darkened color, decreased moisture performance and increased dimensional stability of...

  16. Desirable properties of wood for sustainable development in the twenty-first century

    Science.gov (United States)

    Kenneth E. Skog; Theodore H. Wegner; Ted Bilek; Charles H. Michler

    2015-01-01

    We previously identified desirable properties for wood based on current market-based trends for commercial uses (Wegner et al. 2010). World business models increasingly incorporate the concept of social responsibility and the tenets of sustainable development. Sustainable development is needed to support an estimated 9 billion people by 2050 within the carrying...

  17. Water availability and genetic effects on wood properties of loblolly pine (Pinus taeda)

    Science.gov (United States)

    C. A. Gonzalez-Benecke; T. A. Martin; Alexander Clark; G. F. Peter

    2010-01-01

    We studied the effect of water availability on basal area growth and wood properties of 11-year-old loblolly pine (Pinus taeda L.) trees from contrasting Florida (FL) (a mix of half-sib families) and South Carolina coastal plain (SC) (a single, half-sib family) genetic material. Increasing soil water availability via irrigation increased average wholecore specific...

  18. Use of near infared spectroscopy to measure the chemical and mechanical properties of solid wood

    Science.gov (United States)

    Stephen S. Kelley; Timothy G. Rials; Rebecca Snell; Leslie H. Groom; Amie Sluiter

    2004-01-01

    Near infrared (NIR) spectroscopy (500 nm-2400 nm), coupled with multivariate analytic (MVA) statistical techniques, have been used to predict the chemical and mechanical properties of solid loblolly pine wood. The samples were selected from different radial locations and heights of three loblolly pine trees grown in Arkansas. The chemical composition and mechanical...

  19. Use of near infrared spectroscopy to measure the chemical and mechanical properties of solid wood

    Science.gov (United States)

    Stephen S. Kelley; Timothy G. Rials; Rebecca Snell; Leslie H. Groom; Amie Sluiter

    2004-01-01

    Near infrared (NIR) spectroscopy (500 nm-2400 nm), coupled with multivariate analytic (MVA) statistical techniques, have been used to predict the chemical and mechanical properties of solid loblolly pine wood. The samples were selected from different radial locations and heights of three loblolly pine trees grown in Arkansas. The chemical composition and mechanical...

  20. Anti-Cancer Properties of Diethylether Extract of Wood from Sukun ...

    African Journals Online (AJOL)

    Purpose: To evaluate the anti-cancer properties of the diethylether extract of Sukun (Artocarpus altilis) wood. Methods: The extract was tested in human T47D breast cancer cells and examined for its effect on cell viability, nuclear morphology and sub-G1 formation. Cell viability was determined by microculture tetrazolium ...

  1. Effects of copper amine treatments on mechanical, biological and surface/interphase properties of poly (vinyl chloride)/wood composites

    Science.gov (United States)

    Jiang, Haihong

    2005-11-01

    The copper ethanolamine (CuEA) complex was used as a wood surface modifier and a coupling agent for wood-PVC composites. Mechanical properties of composites, such as unnotched impact strength, flexural strength and flexural toughness, were significantly increased, and fungal decay weight loss was dramatically decreased by wood surface copper amine treatments. It is evident that copper amine was a very effective coupling agent and decay inhibitor for PVC/wood flour composites, especially in high wood flour loading level. A DSC study showed that the heat capacity differences (DeltaCp) of composites before and after PVC glass transition were reduced by adding wood particles. A DMA study revealed that the movements of PVC chain segments during glass transition were limited and obstructed by the presence of wood molecule chains. This restriction effect became stronger by increasing wood flour content and by using Cu-treated wood flour. Wood flour particles acted as "physical cross-linking points" inside the PVC matrix, resulting in the absence of the rubbery plateau of PVC and higher E', E'' above Tg, and smaller tan delta peaks. Enhanced mechanical performances were attributed to the improved wetting condition between PVC melts and wood surfaces, and the formation of a stronger interphase strengthened by chemical interactions between Cu-treated wood flour and the PVC matrix. Contact angles of PVC solution drops on Cu-treated wood surfaces were decreased dramatically compared to those on the untreated surfaces. Acid-base (polar), gammaAB, electron-acceptor (acid) (gamma +), electron-donor (base) (gamma-) surface energy components and the total surface energies increased after wood surface Cu-treatments, indicating a strong tendency toward acid-base or polar interactions. Improved interphase and interfacial adhesion were further confirmed by measuring interfacial shear strength between wood and the PVC matrix.

  2. LEATHER WASTE VALORISATION THROUGH MATERIAL INNOVATION: SOME PROPERTIES OF LEATHER WOOD FIBREBOARD

    Directory of Open Access Journals (Sweden)

    Axel M. RINDLER

    2015-12-01

    Full Text Available Due to the ever-increasing scarcity of resources and raw materials in the wood panels industry, it is imperative to look for suitable alternatives to the established resources. Therefore a combination of the traditionally used and newly explored sources may reveal highly innovative ways. The objective of this study is to provide an insight into the behavior of the material and possible new applications of those fiber/particle wood and waste leather composites. For this reason exclusively fibers of spruce were used for the trials. Wet white (WW leather particles and wet blue (WB leather particles were mixed with the wooden materials for the production of high density fibreboards. Besides the mechanical properties such as the internal bond (IB the bending strength (MOR and modulus of elasticity (MOE was analyzed. Further physical property as thickness swelling after 24h watering was investigated. To analyze how the density influences the behavior under thermal conditions, fiberboards with the densities 500, 700 and 900 kg/m³ were tested. The results of the material properties were influenced by the leather content of the panels. The results for the UF-bonded HDF boards show enhancement of the transverse IB with increasing wet blue leather content, whereas the other mechanical properties decline meanwhile. The thickness swelling showed higher values compared to the wood fibreboard. The results of this study underline the usefulness of integrating leather shavings to HDF and give an overview of their influence in wood fiber materials. The combination of the natural resource wood fiber and the leather waste products (Wet Blue and Wet White gives a very interesting new material, its mechanical properties allow a variety of possible application in future applications.

  3. PHYSICAL AND MECHANICAL PROPERTIES OF BLACK WOOD (EBONY AS A CONSTRUCTION MATERIAL

    Directory of Open Access Journals (Sweden)

    Fengky Satria Yoresta

    2015-01-01

    Full Text Available This research is aimed to determine physical and mechanical properties of Ebony wood as a construction material. The physical and mechanical properties test is conducted based on ASTM D 143-94 code. The mean value of moisture content and specific gravity of Ebony wood is obtained 12,90% and 0,92 gr.cm-3 respectively. Meanwhile MOE, bending strength, compressive strength parallel to grain, shear strength, and tensile strength parallel to grain are 180.425,87 kg.cm-2; 1656,22 kg.cm-2; 861,55 kg.cm-2; 119,61 kg.cm-2; dan 2.319,03 kg.cm-2 respectively. Based on the test results, it can be concluded that Ebony wood is classified to Strength Class I due to PKKI 1961, so it can be recommended for use in heavy construction such as bridge and building structures   Penelitian ini bertujuan menentukan sifat fisis dan mekanis kayu  Ebony sebagai material konstruksi. Pengujian sifat fisis dan mekanis dilakukan berdasarkan standar ASTM D 143-94. -3Nilai kadar air rata-rata kayu Ebony diperoleh sebesar 12,90% dan berat jenis 0,92 gr.cm . Sementara nilai rata-rata MOE, kuat lentur, kuat tekan sejajar serat, kuat geser, dan kuat tarik -2 -2 -2sejajar serat berturut-turut adalah 180.425,87 kg.cm ; 1656,22 kg.cm ; 861,55 kg.cm ; -2 -2119,61 kg.cm ; dan 2.319,03 kg.cm . Berdasarkan hasil penelitian dapat disimpulkan bahwa kayu Ebony tergolong kelas kuat I menurut PKKI 1961, sehingga dapat direkomendasikan untuk digunakan pada konstruksi-konstruksi berat seperti jembatan dan struktur bangunan.   REFERENCES Aghayere A & Jason V. 2007. Structural Wood Design: A Practice-Oriented Approach Using the ASD Method. John Wiley & Sons, Inc., New Jersey Boen T. 2009. Constructing Seismic Resistant Masonry Houses in Indonesia. United Nation. Chauf KA. 2005. Karakteristik Mekanik Kayu Kamper sebagai Bahan Konstruksi. Majalah Ilmiah MEKTEK . Vol 7 : 41-47. Dolan JD. 2004. Timber Structures. Pp 628-669 in Wai FC & Eric ML (Eds Handbook of Structural Engineering – 2nd

  4. Experimental Investigation and Taguchi Optimisation of Drilling Properties on Teak Wood Reinforced Epoxy Resin

    Science.gov (United States)

    Lilly Mercy, J.; Shaqir Tanvir, Mohamed; Swaroopkanth, K.

    2017-05-01

    The drilling properties of teak reinforced epoxy resin composite are explored in this work. The thrust force and temperature during the drilling process was found and optimised. Nine holes were drilled in accordance with L9 orthogonal array on Medium Density Fibre board and Teak wood reinforced epoxy composite board and the thrust force and temperature induced during drilling is measured. Drilling experiments were conducted using CNC Vertical drilling machine and the thrust force was measured using dynamometer and temperature using infra-red thermometer. The experiments were conducted with varying levels of spindle speed and feed rate and optimised using Taguchi optimisation. It was observed that higher thrust and temperature were observed while drilling teak wood composite due to the high mechanical strength of teak wood. The hard and brittle properties of the resin seemed to be more pronounced in the composite. The experimental results were optimised to find the best combination of input parameters for reduced thrust and temperature. When speed increases, thrust force decreases and temperature increases. When feed increases, thrust force increases and temperature decreases. Experimental findings encouragesto use teak wood reinforced epoxy resin as a substitute for the traditionally used Medium Density Fibre Board. The percentage of mixing of teak dust can be increased with various resin combinations to arrive at the best suitable combination for obtaining optimal mechanical properties.

  5. CALORIFIC PROPERTIES OF WASTES FROM SOME EXOTIC WOOD SPECIES

    Directory of Open Access Journals (Sweden)

    Aurel LUNGULEASA

    2016-03-01

    Full Text Available This paper aims to present some results about the calorific properties of biomass wastes from exotic species used as fuels. There are presented the main characteristics of biomass energy, respectively the low and high calorific value, burning speed and energy efficiency. Methodology takes into consideration the equipment, wooden species and relationships for calorific determination. The final conclusion resulting from the experiments is that the biomass of exotic species is as good as any other woody biomass, when is used as fuel, because the calorific properties are closely, even slightly higher than of classical fuels.

  6. Variation in strength, stiffness and related wood properties in young ...

    African Journals Online (AJOL)

    The mean modulus of elasticity measured on edge (MOEedge) was far below, and the mean twist higher than the limits set for structural grade softwood timber in South Africa. All the desirable properties for structural timber improved with distance from the pith with the exception of the fifth percentile value for modulus of ...

  7. Influence of nanoclay on properties of HDPE/wood composites

    Science.gov (United States)

    Yong Lei; Qinglin Wu; Craig M. Clemons; Fei Yao; Yanjun Xu

    2007-01-01

    Composites based on high density polyethylene (HDPE), pine flour, and organic clay were made by melt compounding and then injection molding. The influence of clay on crystallization behavior, mechanical properties, water absorption, and thermal stability of HDPE/pine composites was investigated. The HDPE/pine composites containing exfoliated clay were made by a two-...

  8. ANATOMICAL CHARACTERISTICS AND CHEMICAL PROPERTIES OF THE BRANCH-WOOD OF Schizolobium amazonicum DUCKE SPECIES AND ITS POTENTIAL USES

    Directory of Open Access Journals (Sweden)

    Yusup Amin

    2013-10-01

    Full Text Available The scale of forest degradation and deforestation in Indonesia has inspired the use of lesser-known wood species, which are potentially abundant and so far has not much been utilized. Utilization of these woods should be imposed not only of the stem wood but also of the branch-wood portions. Schizolobiumamazonicum Ducke treeis one of those lesser-known species, and growing fast with an MAIof3.68 cm/year.In Indonesia this species is only found in the Purwodadi Botanical Garden. A research was conducted to study the basic characteristics (anatomical aspects and chemical properties of the branch-wood portion of this species. The branch-wood materials were obtained from the Purwodadi Botanical Garden situated in Pasuruan (East Java. The specimens used were the first branch of the trunk (stem of nine-year old S. amazonicum tree (= 29.46 cm. The branch-wood samples were then examined for the anatomical aspects (macroscopic and microscopic characteristics and chemical properties (chemical composition. Results revealed that the anatomical properties of S.amazonicum branch-wood exhibited close similarities to those of sengon wood; it was light in appearance and white in color. Its fiber averaged about 1500 μm, and based on the fiber dimension's derived values the branch- wood fiber of this species was categorized into first-class quality for pulp and paper manufacture. Further, the chemical composition of this branch-wood compared favorably with that of sengon and mangium wood. The composition of extractive content thatsoluble in alcohol-benzene; lignin; holocellulose; and α-cellulose of this branch-wood were 2.46; 28.71; 80.64; and 50.47%, respectively. The overall assessment implied that the branch-wood portion of S.amazonicum tree affords favorable potential to be developed as raw material for pulp and paper manufacture. Also, considering that both sengon and mangium woods were already used in the pulp and paper industries as well as the trees are

  9. PHYSICAL AND MECHANICAL PROPERTIES OF Araucaria angustifolia (Bertol. WOOD FOR THREE STRATUM PHYTOSOCIOLOGICAL

    Directory of Open Access Journals (Sweden)

    Rafael Beltrame

    2010-11-01

    Full Text Available The study of physical and mechanical properties of wood is essential for industrial use both in construction and the manufacture of furniture. Thus, the study aimed to determine the physical and mechanical properties of the Araucaria angustifolia wood in terms of three strata phytosociological. For this, 15 trees were felled, five belonging to the upper stratum, the middle stratum five and five for the lower strata. The trees were deployed for the preparation of specimens used for mechanical testing. In the mechanical characterization of the species assays were performed for impact resistance, static bending, compression axial and perpendicular to the fibers. As for the characterization of physical properties, determined the apparent specific gravity at 12% relative humidity for each extract. The results did not show significant differences in the tests of impact resistance and static bending to the strata phytosociological. As for the apparent specific gravity, compression axial and perpendicular there was a change in the values of propertiesbetween the strata phytosociological, is generally butter in the middle and upper strata. Therefore the physical and mechanical properties tend to present higher values these two strata. The data analysis allowed of Araucaria angustifolia wood has moderate mechanical strength when compared with other species studies.

  10. INFLUENCE OF COCONUT SHELL ADDITION ON PHYSICO-MECHANICAL PROPERTIES OF WOOD PLASTIC COMPOSITES1

    Directory of Open Access Journals (Sweden)

    Éverton Hillig

    2018-04-01

    Full Text Available ABSTRACT In this study, composites with three types of thermoplastic matrix and cellulosic material in a proportion of 40% were produced. The three thermoplastic matrices were high density polyethylene (HDPE, polypropylene (PP and low density polyethylene (LDPE, and the cellulosic materials were pure wood flour (Pinus taeda L or a mixture of wood flour and coconut shell flour (Cocus nucifera L in equal ratios. The objective was to evaluate the influence of addition of coconut shell on the physico-mechanical properties (density, strength and rigidity and the distribution of the cellulosic material in the thermoplastic matrix of the manufactured composites. It was found that the composites had a satisfactory distribution of wood flour in thermoplastic matrices, but the addition of coconut shell promoted bubble formation in the resulting pieces and, thus, interfered with the material properties. The use of a coupling agent promoted interfacial adhesion (cellulose - thermoplastic matrix, which was better in high density polyethylene composites, followed by polypropylene and low density polyethylene. In general, the coconut shell addition caused a decrease of all properties compared to composites made with Loblolly Pine. In addition, the interactions between thermoplastic type and cellulosic matrix type have been statistically confirmed, which caused variations in the studied properties

  11. Effect of photochemical ageing on the ice nucleation properties of diesel and wood burning particles

    Directory of Open Access Journals (Sweden)

    C. Chou

    2013-01-01

    Full Text Available A measurement campaign (IMBALANCE conducted in 2009 was aimed at characterizing the physical and chemical properties of freshly emitted and photochemically aged combustion particles emitted from a log wood burner and diesel vehicles: a EURO3 Opel Astra with a diesel oxidation catalyst (DOC but no particle filter and a EURO2 Volkswagen Transporter TDI Syncro without emission aftertreatment. Ice nucleation experiments in the deposition and condensation freezing modes were conducted with the Portable Ice Nucleation Chamber (PINC at three nominal temperatures, −30 °C, −35 °C and −40 °C. Freshly emitted diesel particles showed ice formation only at −40 °C in the deposition mode at 137% relative humidity with respect to ice (RHi and 92% relative humidity with respect to water (RHw, and photochemical ageing did not play a role in modifying their ice nucleation behaviour. Only one diesel experiment where α-pinene was added for the ageing process, showed an ice nucleation enhancement at −35 °C. Wood burning particles also act as ice nuclei (IN at −40 °C in the deposition mode at the same conditions as for diesel particles and photochemical ageing also did not alter the ice formation properties of the wood burning particles. Unlike diesel particles, wood burning particles form ice via condensation freezing at −35 °C whereas no ice nucleation was observed at −30 °C. Photochemical ageing did not affect the ice nucleation ability of the diesel and wood burning particles at the three different temperatures investigated but a broader range of temperatures below −40 °C need to be investigated in order to draw an overall conclusion on the effect of photochemical ageing on deposition/condensation ice nucleation across the entire temperature range relevant to cold clouds.

  12. Mechanical and natural durability properties of wood treated with a novel organic preservative/consolidant product

    International Nuclear Information System (INIS)

    Lionetto, Francesca; Frigione, Mariaenrica

    2009-01-01

    An organic preservative/consolidant of new formulation was selected in order to evaluate its effect on the mechanical properties of worm-eaten walnut wood. Walnut wood is widely used for the realization of artistic handworks (e.g. statues, altars, etc.) furniture and flooring. The flexural strength and modulus of elasticity, the toughness and the hardness were determined on both treated and untreated samples. The experimental results showed that the product increased significantly the flexural strength while the other mechanical properties were not appreciably affected by the chemical treatment. The microstructure of the samples tested was observed using scanning electron microscopy. The preserving character against insects of the investigated product was assessed by both visual inspection and measurements of weight loss on the treated specimens after their exposure to living insects. The samples on which the product was applied, exposed to Oligomerus ptilinoides for one year, were more resistant to decay than the corresponding untreated samples.

  13. THERMAL AND DIELECTRIC PROPERTIES OF PINE WOOD IN THE TRANSVERSE DIRECTION

    Directory of Open Access Journals (Sweden)

    Hamiyet Şahin Kol

    2009-11-01

    Full Text Available In this paper, the thermal conductivity and dielectric parameters for pine [Pinus sylvestris (L.] woods were determined in transverse directions for moisture conditions from oven-dry to 22 percent at a room temperature of 22 to 24 °C. Results indicate that the behaviors of thermal conductivity and dielectric parameters with moisture content and structural directions were similar. In general, the properties increased within the range studied with increasing moisture content. The radial values were similar to tangential values for both thermal conductivity and dielectric properties. The data presented here should be useful in most design problems where pine wood is subjected to microwave electric fields and heat changes.

  14. Influence of Water on Tribological Properties of Wood-Polymer Composites

    Science.gov (United States)

    Mysiukiewicz, Olga; Sterzyński, Tomasz

    2017-08-01

    Utilization of ecological materials for appliances and products is one of the ways to achieve the goal of sustainability.Wood-polymer composites as a cheap, lightweight, durable and esthetic material has gained attention of scientists, engineers and consumers alike. Different kinds of polymeric matrices, plants used as the fillers, chemical of physical modifiers and processing technologies have already been widely studied. Nonetheless, surprisingly few information on Wood-Polymer Composites' tribology can be found. This paper is an attempt to fill this gap. Polypropylene-and poly(lactic acid)-based composites with varying wood flour content have been analyzed. The Brinell's hardness and coefficient of friction of the samples have been determined. In order to evaluate the influence of the moisture content on the tribological and mechanical properties of the composites, the samples have also been aged in water. The investigation revealed that polymeric composites filled with wood flour can present favorable coefficient of friction, compared to the neat resins. The results of our study can establish a good starting point for further investigation.

  15. Study of mechanical properties of Palosangre wood (Brosimum rubescens Taub.), from Leticia-Colombia provenance

    International Nuclear Information System (INIS)

    Triana Gomez, Max Alejandro; Gonzalez Roso, Gladis; Paspur Posso, Segundo Demetrio

    2008-01-01

    The technical recommendations of the Pan-American Committee of Technical Norms COPANT were applied for carrying out technological tests of tangential static flexion, parallel compression, tangential parallel shear, radial parallel shear, tangential impact, and radial impact in the wood of Brosimum rubescens Taub. (Moraceae) coming from Leticia, state of Amazonas, Colombia. The statistical analysis was made based on the arithmetic mean, the standard deviation and the variation coefficient to obtain representativeness. Results were adjusted to 12% of content of humidity. The mechanical properties of the wood were also classified, and its possible uses determined. The wood of B. rubescens exhibited the best response to the static flexion effort. According to the ASTM classification, the elasticity module (MOE) and the Maximum Unitary Effort corresponded to the Very High range, while the Proportional Limit Effort to the Middle range. The Maximum Unitary Effort and Proportional Limit Effort obtained for the parallel compression were assigned to the High and Medium ranges, respectively, while the tangential shear matched the High range. The less favorable response was found for the radial shear effort and the impact in the tangential and radial planes that corresponded to the Medium range. It was found that the most appropriate uses of the wood were: interior finishes, external finishes, athletic and sport articles, hand crafts, ends for tools, joinery, furniture, chassis, piles, musical instruments, construction, arches for violin and similar musical instruments, breeches for weapons, structures, mischievous, keels, floors and beams.

  16. Wood properties of Populus and Betula in long-term exposure to elevated CO₂ and O₃.

    Science.gov (United States)

    Kostiainen, Katri; Saranpää, Pekka; Lundqvist, Sven-Olof; Kubiske, Mark E; Vapaavuori, Elina

    2014-06-01

    We studied the interactive effects of elevated concentrations of CO2 and O3 on radial growth and wood properties of four trembling aspen (Populus tremuloides Michx.) clones and paper birch (Betula papyrifera Marsh.) saplings. The material for the study was collected from the Aspen FACE (free-air CO2 enrichment) experiment in Rhinelander (WI, USA). Trees had been exposed to four treatments [control, elevated CO2 (560 ppm), elevated O3 (1.5 times ambient) and combined CO2 + O3 ] during growing seasons 1998-2008. Most treatment responses were observed in the early phase of experiment. Our results show that the CO2- and O3-exposed aspen trees displayed a differential balance between efficiency and safety of water transport. Under elevated CO2, radial growth was enhanced and the trees had fewer but hydraulically more efficient larger diameter vessels. In contrast, elevated O3 decreased radial growth and the diameters of vessels and fibres. Clone-specific decrease in wood density and cell wall thickness was observed under elevated CO2 . In birch, the treatments had no major impacts on wood anatomy or wood density. Our study indicates that short-term impact studies conducted with young seedlings may not give a realistic view of long-term ecosystem responses. © 2013 John Wiley & Sons Ltd.

  17. In-Situ Preparation and Magnetic Properties of Fe3O4/WOOD Composite

    Science.gov (United States)

    Gao, Honglin; Zhang, Genlin; Wu, Guoyuan; Guan, Hongtao

    2011-06-01

    Fe3O4/wood composite, a magnetic material, was prepared by In-situ chemosynthesis method at room temperature. The X-ray diffraction (XRD) shows that the average partical size of Fe3O4 was about 14 nm. The magnetic properties of the resulting composites were investigated by vibrating sample magnetometer (VSM). The composites have saturation magnetization (Ms) values from 4.7 to 25.3 emu/g with the increase of weight percent gains (WPG) of the wood for the composites, but coercive forces (Hc) are invariable, which is different from the magnetic materials reported before. It may be due to the fact that the interaction between wood and Fe3O4 becomes stronger when less of Fe3O4 particles are introduced in the composition, and this also changes the surface anisotropy (Ks) of the magnetism. A structural characterization by Fourier transform infrared (FTIR) proved the interaction between Fe3O4 particles and wood matrix, and it also illustrates that this interaction influences the coercive force of the composite.

  18. Effect of boron compounds on physical, mechanical, and fire properties of injection molded wood plastic composites

    Science.gov (United States)

    Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Zeki Candan; Umit Buyuksari; Erkan Avci

    2011-01-01

    Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites (WPCs) incorporated with different levels of boron compounds, borax/boric acid (BX/BA) (0.5:0.5 wt %) and zinc borate (ZB) (4, 8, or 12 wt %) were investigated. The effect of the coupling agent loading (2, 4, or 6 wt %), maleic anhydride-grafted PP (MAPP), on the...

  19. Quantifying and modelling the effects of environmental factors on wood properties of Eucalyptus grandis in South Africa

    CSIR Research Space (South Africa)

    Naidoo, Sasha

    2011-03-01

    Full Text Available screening techniques. Furthermore, because this species lacks distinct annual boundaries that correspond to seasonal climatic changes, the change in wood properties with age usually cannot be studied with reasonable accuracy. For this reason, a study...

  20. Some Exploitation Properties of Wood Plastic Hybrid Composites Based on Polypropylene and Plywood Production Waste

    Science.gov (United States)

    Kajaks, Janis; Kalnins, Karlis; Uzulis, Sandris; Matvejs, Juris

    2015-12-01

    During the last 20-30 years many researchers have paid attention to the studies of properties of thewood polymer composites (WPC). A lot of works are closely related to investigations of exploitation properties of wood fibres or wood flour containing polyolefine composites [1, 2]. The most useful from wide selection of polyolefines are polypropylenes, but timber industry waste materials comprising lignocellulose fibres are often used as reinforcement of WPC [3-12]. Plywood industry is not an exception - part of waste materials (by-products) are used for heat energy, i.e. burned. In this work we have approbated reinforcing of polypropylene (PP) with one of the plywood industry by-products, such as birch plywood sawdust (PSWD),which containswood fibre fractions with different length [13]. The main fraction (50%) includes fibres with length l = 0.5 - 1 mm. Our previous study [13] has confirmed that PSWD is a promising filler for PP reinforcing. Addition of PSWD up to 40-50 wt.% has increased WPC tensile and flexural modulus, but decreased deformation ability of PP matrix, impact strength, water resistance and fluidity of composite melts. It was shown [13] that modification of the composites with interfacial modifier - coupling agent maleated polypropylene (MAPP content up to 5-7 wt.%) considerably improved all the abovementioned properties. SEM investigations also confirmed positive action of coupling agent on strengthening of adhesion interaction between components wood and PP matrix. Another way how to make better properties of the WPC is to form hybridcomposites [1, 14-24]. Very popular WPC modifiers are nanoparticle additions like organonanoclays, which increase WPC physical-mechanical properties - microhardness, water resistance and diminish barrier properties and combustibility [1, 2, 14-17, 19, 20]. The goal of this study was to investigate organonanoclays influence on plywood production industry by-product birch plywood sawdust (PSWD) containing

  1. Physical properties and fiber dimension in Stem, Branch and root of Alder Wood

    OpenAIRE

    Moya-Roque, Roger; Kiaei, Majid

    2015-01-01

    The aim of this study was to determine physical properties and fiber dimensions in stem, branch and root wood for alder (Alnus glutinosa L) species. For this purpose, three normal alder trees were selected from Khanican forest in north of Iran. Disks were taken from three parts such as stem, branch and root of trees. Testing samples were randomly taken at disk surfaces to examine the physical properties (according to the ISO standard for oven-dry density and volumetric shrinkage) and fiber di...

  2. FAST PYROLYSIS – EFFECT OF WOOD DRYING ON THE YIELD AND PROPERTIES OF BIO-OIL

    Directory of Open Access Journals (Sweden)

    Eriks Samulis

    2007-11-01

    Full Text Available The composition and properties of the products of fast pyrolysis of hardwood, obtained in a two-chamber (drying and pyrolytic ablation type reactor in the temperature range 450-600ºС, were investigated. It has been found that, upon the additional drying of wood at 200ºС and subsequent pyrolysis, the quality of bio-oil is improved owing to the decrease in the amount of water and acids. It has been shown that the increase of the drying temperature to 240ºС decreases the yield of the main product. Optimum parameters of the drying conditions and the temperature of the pyrolysis of wood, at which the bio-oil yield exceeds 60% and its calorific value makes up 17-20 МJ/kg, have been determined.

  3. Eucalyptus wood and coffee parchment for particleboard production: Physical and mechanical properties

    Directory of Open Access Journals (Sweden)

    Mário Vanoli Scatolino

    Full Text Available ABSTRACT The wood panel industry is constantly growing, being necessary the innovation in technologies and raw materials to improve the quality of the final product. Considering the shortage and pressure to decrease the dependence of wood, there is an interest in other renewable materials such as agricultural wastes. Among these wastes, coffee parchment is one which deserves notoriety. An alternative use for coffee parchment could be for production of particleboard in association with wood particles. This study aimed to evaluate the feasibility of using coffee parchment for production of particleboard. The following percentages of wastes were used: 0, 10, 20, 30, 40 and 50% in association to eucalyptus wood. The panels were produced with 8% of urea formaldehyde (based on dry weight of particles. The pressing cycle consisted by: pre-pressing of 0.5 MPa for 10 minutes followed by pressing of 4.0 MPa, and temperature of 160° C for 15 minutes. The compaction ratio of particleboards produced using higher quantities of parchment improved the physical properties. The properties of Water Absorption (2 and 24 h and Thickness Swelling (2 h decreased with increasing percentage of coffee parchment. The Thickness Swelling (24 h showed not significant effect with an increase of coffee waste. The Modulus of Elasticity for coffee parchment particleboards was in the range 646.49 ± 112.65 to 402.03 ± 66.24 MPa, while the Modulus of Rupture ranged from 8.18 ± 1.39 to 4.45 ± 0.75 MPa. The results showed that 10% of coffee parchment could be added for production of particleboards.

  4. Chemical composition and sensory properties of non-wooded and wooded Shiraz (Vitis vinifera L.) wine as affected by vineyard row orientation and grape ripeness level.

    Science.gov (United States)

    Hunter, Jacobus J; Volschenk, Cornelis G

    2018-05-01

    The study aimed to unravel vineyard row orientation (NS, EW, NE-SW, NW-SE) and grape ripeness level (23, 25, 27 °Balling) implications for grape and wine composition and sensory properties/style (non-wooded/wooded wines) of Vitis vinifera L. cv. Shiraz (rootstock 101-14 Mgt). Soluble solid/titratable acidity ratios were lowest for EW, whereas warmer canopy sides (NW, N, NE) advanced grape ripening. Skin anthocyanins and phenolics generally decreased with ripening. NW-SE rows and S, SE, E and NE canopy sides showed highest skin total anthocyanins and phenolics. Wine total anthocyanins and phenolics increased with grape ripening; EW had lower values. Wine phenolic contents differed between canopy sides; N, NE, E and SE tended higher. Wine sensory profiles increased with grape ripening. For non-wooded wines, NW-SE and NE-SW row orientations generally resulted in highest scores, followed by NS. For EW rows, the N side presented better wines. Wood addition enhanced specific sensory descriptor perceptions. A large collection of wine styles surfaced in the same vineyard and terroir, increasing options to contribute positively to sustainable products. The study generated globally applicable, novel information vital for unlocking and valorising terroir/site potential for grape and wine chemical composition and wine sensory/style properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  5. EFFECT OF REMOVING OLEORESIN WITH VARIOUS CHEMICAL COMPOUNDS ON PHYSICAL AND MECHANICAL PROPERTIES OF KERUING WOOD (DIPTEROCARPUS SPP.

    Directory of Open Access Journals (Sweden)

    Bambang Wiyono

    2007-03-01

    Full Text Available Keruing  (Dipterocarpus spp.  was  the  second  important  wood  export of   Indonesia. Unfortunately, this wood contains oleoresin that hinders its utilization. Currently, the method used to remove oleoresin from keruing is by soaking it into bollied sodium salt solution. Result of  this method is unsatisfactory because the residual heavy oleoresin might still appear on the wood surface. The study was conducted to determine suitable chemical compounds for removing oleoresin from keruing, and the effects on physical and mechanical properties of the wood. Four types of chemical compounds were tested, i.e. sodium chloride, oxalic acid, sulfuric acid, and nitric acid, each at the concentrations of  0.5 percent, 1.0 percent, and 1.5 percent. Wood samples were soaked in the boiling solution at different concentration level for seven hours. When the solution cooled down, the oleoresin exudated out of  the wood samples was separated. The oleoresin was weighed for recovery determination after air dried, and the wood samples were cut into smaller-sized specimens for the physical and mechanical testing (MOE, MOR, compression parallel to grain, hardness and density. Results showed that sulfuric acid was the best chemical compound for removing oleoresin, and the higher the concentration the greater the oleoresin recovery. The second best chemical compound was nitric acid at an optimum concentration of one percent. The soaking of keruing in sulfuric acid and oxalic acid solution resulted in paler wood color compare with the untreated wood sample. Nitric acid solutions caused the color of the wood surface to turn into yellow brownish. The physical and mechanical properties (MOE, MOR, compression parallel to grain, hardness and density of the oleoresin-removed keruing were slightly lower than the untreated (control samples.

  6. BROMINATION OF 4-VINYLCYCLOHEXANE AND APPLYING THE RESULTING PRODUCT TO IMPROVE THE FLAME RETARDANT PROPERTIES OF WOOD

    Directory of Open Access Journals (Sweden)

    N. S. Nikulina

    2014-01-01

    Full Text Available Currently, the demand for timber is increasing. Wood and products on its basis are considered to be the most popular in the construction industry, furniture industry, as building materials and other However, along with the positive features of this material there are also negative factors, which include low resistance to biological degradation, high temperature, resistance. Wood and materials based on it are the most flammable, and fire safety is characterized by the velocity of propagation of fire on the wooden structure. He is able to destroy it in a matter of minutes. So the wooden house elements must be protected from fire. It was therefore necessary for the fire protection of wood. It is in the handling of wood with flame retardants. Basic fire fighting methods is the impregnation of wood antipyrene composition, painting fire paint and constructive ways - insulation of timber, non-combustible compositions which can resist the fire. In the work of brominated 4-vinylcyclohexane formed as a by-product in the petrochemical industry, in chloroform synthesized compound with bromine 62-64 % and the possibility of using this product to get antiferromag composition. It is established that the application for the protective treatment of wood synthesized flame retardant has shown that this product can be used for the protective treatment of natural wood to make it flame retardant properties. Use as antiperiodic compositions bromodomain based products 4-vinylcyclohexane allows to obtain images of wood first group of flame retardant efficiency.

  7. Characterization of dielectric properties of nanocellulose from wood and algae for electrical insulator applications.

    Science.gov (United States)

    Le Bras, David; Strømme, Maria; Mihranyan, Albert

    2015-05-07

    Cellulose is one of the oldest electrically insulating materials used in oil-filled high-power transformers and cables. However, reports on the dielectric properties of nanocellulose for electrical insulator applications are scarce. The aim of this study was to characterize the dielectric properties of two nanocellulose types from wood, viz., nanofibrillated cellulose (NFC), and algae, viz., Cladophora cellulose, for electrical insulator applications. The cellulose materials were characterized with X-ray diffraction, nitrogen gas and moisture sorption isotherms, helium pycnometry, mechanical testing, and dielectric spectroscopy at various relative humidities. The algae nanocellulose sample was more crystalline and had a lower moisture sorption capacity at low and moderate relative humidities, compared to NFC. On the other hand, it was much more porous, which resulted in lower strength and higher dielectric loss than for NFC. It is concluded that the solid-state properties of nanocellulose may have a substantial impact on the dielectric properties of electrical insulator applications.

  8. Mechanical Properties of Wood Flour Reinforced High Density Polyethylene Composites with Basalt Fibers

    Directory of Open Access Journals (Sweden)

    Guojun LU

    2014-12-01

    Full Text Available Basalt fibers (BFs were surface-treated with a vinyl triethoxy silane coupling agent to improve the mechanical properties of wood fiber-reinforced high density polyethylene (HDPE composites. Basalt fibers were characterized with SEM and FT-IR. The effects of the basalt fiber content and apparent morphology on the mechanical properties of the hybrid composites were investigated in this paper. The results show that the BF coated with the vinyl triethoxy silane coupling agent resulted in an improvement in mechanical properties due to the increased interfacial compatibility between the BF and HDPE. The flexural strength and impact properties significantly increased with 4 wt.% modified basalt fibers. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6441

  9. Wood Modification at High Temperature and Pressurized Steam: a Relational Model of Mechanical Properties Based on a Neural Network

    Directory of Open Access Journals (Sweden)

    Hong Yang

    2015-07-01

    Full Text Available Thermally modified wood has high dimensional stability and biological durability.But if the process parameters of thermal modification are not appropriate, then there will be a decline in the physical properties of wood.A neural network algorithm was employed in this study to establish the relationship between the process parameters of high-temperature and high-pressure thermal modification and the mechanical properties of the wood. Three important parameters: temperature, relative humidity, and treatment time, were considered as the inputs to the neural network. Back propagation (BP neural network and radial basis function (RBF neural network models for prediction were built and compared. The comparison showed that the RBF neural network model had advantages in network structure, convergence speed, and generalization capacity. On this basis, the inverse model, reflecting the relationship between the process parameters and the mechanical properties of wood, was established. Given the desired mechanical properties of the wood, the thermal modification process parameters could be inversely optimized and predicted. The results indicated that the model has good learning ability and generalization capacity. This is of great importance for the theoretical and applicational studies of the thermal modification of wood.

  10. Stone-ground wood pulp-reinforced polypropylene composites: Water uptake and thermal properties

    Directory of Open Access Journals (Sweden)

    Joan Pere López

    2012-11-01

    Full Text Available Two of the drawbacks of using natural-based composites in industrial applications are thermal instability and water uptake capacity. In this work, mechanical wood pulp was used to reinforce polypropylene at a level of 20 to 50 wt. %. Composites were mixed by means of a Brabender internal mixer for both non-coupled and coupled formulations. Differential scanning calorimetry (DSC and thermogravimetric analysis (TGA were used to determine the thermal properties of the composites. The water uptake behavior was evaluated by immersion of the composites in water until an equilibrium state was reached. Results of water absorption tests revealed that the amount of water absorption was clearly dependent upon the fiber content. The coupled composites showed lower water absorption compared to the uncoupled composites. The incorporation of mechanical wood pulp into the polypropylene matrix produced a clear nucleating effect by increasing the crystallinity degree of the polymer and also increasing the temperature of polymer degradation. The maximum degradation temperature for stone ground wood pulp–reinforced composites was in the range of 330 to 345 ºC.

  11. Studies on thermal degradation and termite resistant properties of chemically modified wood

    Energy Technology Data Exchange (ETDEWEB)

    Deka, M.; Saikia, C.N. [Council for Scientific and Industrial Research (CSIR), Regional Research Laboratory, Jorhat (India); Baruah, K.K. [Assam Agricultural University, Jorhat (India)

    2002-09-01

    A series of experiments were carried out to examine the resistant capacity of a chemically treated hard wood, Anthocephalus cadamba (Roxb) Miq. to thermal and termite degradation. The treatment with thermosetting resins viz. urea formaldehyde (UF), melamine formaldehyde (MF) and phenol formaldehyde (PF) at 31-33 levels of weight percent gain (WPG) increased the strength property i.e. modulus of rupture (MOR) by 7.50-21.02% and stiffness i.e. modulus of elasticity (MOE) by 9.50-12.18% over the untreated one with no remarkable effect on specific gravity. The treated samples were found resistant to termite attack, while the untreated one was badly damaged by termites on 12 months' exposure to a termite colony. The thermal degradations of untreated and treated wood samples were studied using thermogravimetric (TGA) and differential thermogravimetric (DTG) techniques at heating rates 20 and 30 {sup o}Cmin{sup -1} in temperature range 30-650{sup o}C. The treated wood was found to be thermally more stable than the untreated one. (author)

  12. THE DIFFERENCE OF MACHINING PROPERTIES OF TIMO (Timonius sericeus (Desf K. Schum. And KABESAK WOOD (Acacia leucophloea (Roxb. Willd. FROM EAST NUSA TENGGARA

    Directory of Open Access Journals (Sweden)

    Heny Rianawati

    2015-09-01

    Full Text Available Machining properties is one of the parameters to determine the quality of the wood. Tests on machining properties of wood are important to know the easiness level of workmanship as raw materials of furniture industry, construction wood and other wood products. This research was aimed at determining the difference of machining properties between timo wood (Timonius sericeus (Desf K. Schum. and kabesak wood (Acacia leucophloea (Roxb. Willd. from the village of Reknamo, Kupang district, East Nusa Tenggara. Testing procedures were based on ASTM D1666 including: planning, shaping, sanding, drilling and turning. The observation of qualities of the machining were done visually by calculating the percentage of defects that arise on the surface of the samples after the machining process, then the qualities were classified into five quality classes. The results showed that the machining properties of timo wood and kabesak wood were very good and belonging to the quality of class I. The significant difference between the machining properties of both the timbers is in the sanding properties, where the average free defect of sanding timo wood is 85% while kabesak wood is 84.5%. Both timo and kabesak wood are suitable as raw material, for the variety of furniture and molding products.

  13. WATER VAPOUR PERMEABILITY PROPERTIES OF CELLULAR WOOD MATERIAL AND CONDENSATION RISK OF COMPOSITE PANEL WALLS

    Directory of Open Access Journals (Sweden)

    Janis IEJAVS

    2016-09-01

    Full Text Available Invention of light weight cellular wood material (CWM with a trade mark of Dendrolight is one of innovations in wood industry of the last decade. The aim of the research was to define the water vapour permeability properties of CWM and to analyse the condensation risk of various wall envelopes where solid wood cellular material is used. To determine the water vapour permeability of CWM, test samples were produced in the factory using routine production technology and tested according to the standard EN 12086:2014. Water vapour permeability factor (μ and other properties of six different configurations of CWM samples were determined. Using the experimental data the indicative influence of geometrical parameters such as lamella thickness, number of lamellas and material direction were investigated and evaluated. To study the condensation risk within the wall envelope containing CWM calculation method given in LVS EN ISO 13788:2012 was used. To ease the calculation process previously developed JavaScript calculation software that had only capability to calculate thermal transmittance was extended so that condensation risk in multi-layer composite walls can be analysed. Water vapour permeability factor in CWM is highly direction dependant. If parallel and perpendicular direction of CWM is compared the value of water vapour permeability factor can differentiate more than two times. Another significant factor for condensation risk analysis is overall thickness of CWM since it directly influences the equivalent air layer thickness. The influence of other factors such as lamella thickness, or groove depth is minor when water vapour permeability properties are compared. From the analysis of CWM performance in building envelope it can be concluded that uninsulated CWM panels used during winter months will pose the risk of condensation damage to structure, but the risk can be reduced or prevented if insulation layer is applied to the CWM panel wall

  14. Surface coating influence on elastic properties of spruce wood by means of holographic vibration mode visualization

    Science.gov (United States)

    Bongova, M.; Urgela, Stanislav

    1999-07-01

    Physicoacoustical properties of wood influenced by surface coating are studied by modal analysis. Resonant spruce plates were coated by stain, nitrocellulose varnish, special violin paint and shellac. The modal testing was performed by electronic speckle pattern interferometry. For this purpose, equipment called VIBROVIZER was used. The collected values of physicoacoustical characteristics (density, Young's modulus, acoustic constant) were compared using the graphic plots of data. The 3D plots help to evaluate wooden plates from a viewpoint of the quality control. This fact offers new opportunity for musical instrument manufacturers.

  15. Cadmium Accumulation in Small Mammals: Species Traits, Soil Properties, and Spatial Habitat Use

    NARCIS (Netherlands)

    Brink, van den N.W.; Lammertsma, D.R.; Dimmers, W.J.; Boerwinkel, M.C.

    2011-01-01

    In this study, the impact of species-specific spatial habitat use, diet preferences, and soil concentrations and properties on the accumulation of cadmium in small mammals was investigated. The results show that for the wood mouse (Apodemus sylvaticus), a mobile species with a large range in diet

  16. Effect of PVA-co-MMA Copolymer on the Physical, Mechanical, and Thermal Properties of Tropical Wood Materials

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2014-01-01

    Full Text Available The present study demonstrates the effect of copolymer on the physical, mechanical, and thermal properties of tropical wood and wood polymer composites (WPCs. Mixed monomers of methyl methacrylate (MMA and polyvinyl alcohol (PVA were effectively impregnated into the cellular structure of several types of tropical wood, which then underwent a catalyst-thermal process to polymerize and form WPC. The manufacturing of WPC was confirmed through Fourier transform infrared (FTIR spectroscopy and scanning electron microscopic (SEM analysis. The SEM observation showed that polymer converted from monomers filled up wood cell cavities and tightly interacted with wood matrix. The X-ray diffraction results reveal that the degree of crystallinity was significantly improved upon impregnation with PVA-co-MMA copolymer. The modulus of elasticity (MOE and compressive modulus were found to be significantly higher after treatment with MMA/PVA indicating improvement of mechanical properties of the wood samples. In addition, the modified WPC had lower water absorption compared to their corresponding raw samples. It is interesting to note that thermogravimetric (TGA analysis shows an extensive improvement in thermal properties of WPC.

  17. Evaluation of mechanical properties and durability performance of HDPE-wood composites

    International Nuclear Information System (INIS)

    Tazi, M.; Erchiqui, F.; Kaddami, H.; Bouazara, M.; Poaty, B.

    2015-01-01

    The objective of this work is to evaluate the mechanical properties and durability performance of bio-composite materials made from sawdust and thermoplastic polymer (HDPE). For the preparation of the composites, sawdust in different proportions with Maleic Anhydride grafted Polyethylene (MAPE) as the coupling agent was used. The thermal and mechanical properties were successively characterized. The results indicate that adding wood fillers to a polymer matrix increases the degree of crystallinity and improves the tensile strength and ductility of composites. On the contrary, resistance to water absorption decreases as a function of the wood fillers. Scanning electron microscopy (SEM) was used to analyze morphological structure alteration when exposed to intense weathering. The biodegradability of bio-composites up to 97 days was also investigated; the results indicate that, by increasing the filler content, the amount of weight loss increased as well. In other words, even though the addition of sawdust to thermoplastic polymer improves the mechanical performance of a composite material, it also accelerates the biodegradation rate of the composite. An optimum amount of filler content might compromise the effect of biodegradation and mechanical properties of composite materials

  18. Evaluation of mechanical properties and durability performance of HDPE-wood composites

    Energy Technology Data Exchange (ETDEWEB)

    Tazi, M.; Erchiqui, F. [Engineering department, Université de Quebec en Abitibi-Témiscamingue (Canada); Kaddami, H. [Université Caddi Ayad Marrakech, Laboratoire ’LCO2MC’, B.P. 549, Marrakech 40000, Maroc (Morocco); Bouazara, M. [Mechanical department, Université de Québec à Chicoutimi Canada (Canada); Poaty, B. [Technology Center of industrial residuals, QC Canada (Canada)

    2015-05-22

    The objective of this work is to evaluate the mechanical properties and durability performance of bio-composite materials made from sawdust and thermoplastic polymer (HDPE). For the preparation of the composites, sawdust in different proportions with Maleic Anhydride grafted Polyethylene (MAPE) as the coupling agent was used. The thermal and mechanical properties were successively characterized. The results indicate that adding wood fillers to a polymer matrix increases the degree of crystallinity and improves the tensile strength and ductility of composites. On the contrary, resistance to water absorption decreases as a function of the wood fillers. Scanning electron microscopy (SEM) was used to analyze morphological structure alteration when exposed to intense weathering. The biodegradability of bio-composites up to 97 days was also investigated; the results indicate that, by increasing the filler content, the amount of weight loss increased as well. In other words, even though the addition of sawdust to thermoplastic polymer improves the mechanical performance of a composite material, it also accelerates the biodegradation rate of the composite. An optimum amount of filler content might compromise the effect of biodegradation and mechanical properties of composite materials.

  19. EFFECTS OF ETHYLENE VINYL ACETATE CONTENT ON PHYSICAL AND MECHANICAL PROPERTIES OF WOOD-PLASTIC COMPOSITES

    Directory of Open Access Journals (Sweden)

    Dongfang Li,

    2012-05-01

    Full Text Available To investigate the effects of different ethylene vinyl acetate (EVA contents on the performance of wood plastic composites (WPCs made from poplar wood flour (PWF and high density polyethylene (HDPE, physical properties tests, mechanical properties tests, and scanning electron microscope (SEM tests were employed. The thermal stability and functional groups of PWF treated by EVA were evaluated by thermogravimetric analysis (TGA, differential thermal analysis (DTA, and Fourier transform infrared spectroscopy (FTIR, respectively. The results showed that the hardness, water uptake, and thickness swelling of the WPCs was reduced with increasing content of EVA. The MOR and tensile strength of the WPC treated by 15% EVA content were enhanced by 17.48% and 9.97%, respectively, compared with those of the WPC without EVA. TGA results showed that the thermal stability of PWF treated by EVA was improved. FTIR analysis indicated that PWF was reacted and coated with EVA. SEM results showed that gaps and voids hardly existed in the sections of the WPCs treated by EVA. This research suggests that the flexibility and mechanical properties of WPCs could be improved by adding EVA. The best condition of EVA content could be 15%.

  20. High-Temperature Hot Air/Silane Coupling Modification of Wood Fiber and Its Effect on Properties of Wood Fiber/HDPE Composites

    Directory of Open Access Journals (Sweden)

    Feng Chen

    2017-03-01

    Full Text Available The surfaces of poplar wood fibers were modified using high-temperature hot air (HTHA treatment and silane coupling agent. The single factor test was then used to investigate the performances (e.g., the change of functional groups, polarity, cellulose crystallinity, and thermal stability of modified poplar wood fibers (mPWF through Fourier transform infrared spectrometry, X-ray diffraction and thermo-gravimetric analysis for the subsequent preparation of wood-plastic composites (WPCs. The effect of HTHA treatment conditions—such as temperature, inlet air velocity, and feed rate—on the performances of WPCs was also investigated by scanning electron microscopy and dynamic mechanical analysis. The main findings indicated that HTHA treatment could promote the hydration of mPWF and improve the mechanical properties of WPCs. Treatment temperature strongly affected the mechanical properties and moisture adsorption characteristics of the prepared composites. With the increase of treated temperature and feed rate, the number of hydroxyl groups, holocellulose content, and the pH of mPWF decreased. The degree of crystallinity and thermal stability and the storage modulus of the prepared composites of mPWF increased. However, dimensional stability and water absorption of WPCs significantly reduced. The best mechanical properties enhancement was observed with treatment temperature at 220 °C. This study demonstrated the feasibility for the application of an HTHA treatment in the WPC production industry.

  1. Testing a Novel Method to Approximate Wood Specific Gravity of Trees

    Science.gov (United States)

    Michael C. Wiemann; G. Bruce. Williamson

    2012-01-01

    Wood specific gravity (SG) has long been used by foresters as an index for wood properties. More recently, SG has been widely used by ecologists as a plant functional trait and as a key variable in estimates of biomass. However, sampling wood to determine SG can be problematic; at present, the most common method is sampling with an increment borer to extract a bark-to-...

  2. Effect of the Addition of Carbon Nanomaterials on Electrical and Mechanical Properties of Wood Plastic Composites

    Directory of Open Access Journals (Sweden)

    Xingli Zhang

    2017-11-01

    Full Text Available Wood Plastic Composites (WPCs are a new generation of green composites that could optimize the use of harvested trees and increase the entire value chain. In this study, the electrical and mechanical properties of WPCs containing carbon blacks (CB, flake graphite (FG and carbon nanotubes (CNTs have been investigated. The electrical property of WPCs is improved significantly owing to the introduction of these carbon nanomaterial fillers. The volume and surface resistivity values of the investigated composites all obviously decreased with the increase in filler content, especially CNTs, which displayed the most satisfactory results. Based on a series of laboratory experiments carried out to investigate the mechanical performance, it can be concluded that the addition of the carbon nanomaterial fillers decreases the mechanical properties of WPCs slightly with the increase in filler content because of the weak interfacial interactions between the fillers and polymer matrix.

  3. A supramolecular proposal of lignin structure and its relation with the wood properties

    Directory of Open Access Journals (Sweden)

    Heber S. Abreu

    2009-03-01

    Full Text Available In spite of the great importance of cellulose the lignin is considered the second most abundant substance of the wood. However, little attention has been given it, mainly to wood properties. The lignin as well as other structural compounds (cellulose and hemicelluloses, has obviously an important role on the wood properties, probably due its composition and existent bonds. In general lignins have β-O-4 (Alkyl Aril Ether as majoritary bond. This bond in a continued structure form big molecules with spiral conformation as virtual model. Based on this idea, lignins that have high/low β-O-4 content may have differentiated spiraled structures,suggesting different behaviors on the wood properties,which shows that the lignins (Guaicyl:Syringyl (GS of angiosperms, for example, which have higher β-O-4 content would present higher spiral conformation than gymnosperms lignins(HG. On the other hand HG lignins have chance of being more anchored on the matrix compound than GS lignins. In this context, the β-O-4 bonds of lignins possibly affect the wood properties, therefore, it is considered relevant for wood technology science discussion.Apesar da grande importância da celulose a lignina é considerada a segunda substância mais abundante da madeira. Entretanto, pouca atenção tem sido dada a ela, principalmente com relação às propriedades da madeira. A lignina assim como outras substâncias (celulose e hemicelulose, tem obviamente um papel importante sobre as propriedades da madeira, provavelmente devido a sua composição e a existências de ligações. Geralmente as ligninas possuem majoritariamente ligaçõesβ-O-4 (Éter Alquil-Arílico, esta ligação em uma estrutura contínua forma grandes moléculas com conformação em espiral, como visto em modelo virtual. Com base nesta idéia, ligninas que possuem alto/baixo teor de β-O-4, podem ter estruturas espiraladas diferenciadas, sugerindo comportamentos diferentes sobre as propriedades da

  4. Changes in wood density, wood anatomy and hydraulic properties of the xylem along the root-to-shoot flow path in tropical rainforest trees.

    Science.gov (United States)

    Schuldt, Bernhard; Leuschner, Christoph; Brock, Nicolai; Horna, Viviana

    2013-02-01

    It is generally assumed that the largest vessels are occurring in the roots and that vessel diameters and the related hydraulic conductance in the xylem are decreasing acropetally from roots to leaves. With this study in five tree species of a perhumid tropical rainforest in Sulawesi (Indonesia), we searched for patterns in hydraulic architecture and axial conductivity along the flow path from small-diameter roots through strong roots and the trunk to distal sun-canopy twigs. Wood density differed by not more than 10% across the different flow path positions in a species, and branch and stem wood density were closely related in three of the five species. Other than wood density, the wood anatomical and xylem hydraulic traits varied in dependence on the position along the flow path, but were unrelated to wood density within a tree. In contrast to reports from conifers and certain dicotyledonous species, we found a hump-shaped variation in vessel diameter and sapwood area--specific conductivity along the flow path in all five species with a maximum in the trunk and strong roots and minima in both small roots and twigs; the vessel size depended on the diameter of the organ. This pattern might be an adaptation to the perhumid climate with a low risk of hydraulic failure. Despite a similar mean vessel diameter in small roots and twigs, the two distal organs, hydraulically weighted mean vessel diameters were on average 30% larger in small roots, resulting in ∼ 85% higher empirical and theoretical specific conductivities. Relative vessel lumen area in percent of sapwood area decreased linearly by 70% from roots to twigs, reflecting the increase in sclerenchymatic tissue and tracheids in acropetal direction in the xylem. Vessel size was more closely related to the organ diameter than to the distance along the root-to-shoot flow path. We conclude that (i) the five co-occurring tree species show convergent patterns in their hydraulic architecture despite different growth

  5. Effect of boron and phosphate compounds on physical, mechanical, and fire properties of wood-polypropylene composites

    Science.gov (United States)

    Nadir Ayrilmis; Turgay Akbulut; Turker Dundar; Robert H. White; Fatih Mengeloglu; Umit Buyuksari; Zeki Candan; Erkan Avci

    2012-01-01

    Physical, mechanical, and fire properties of the injection-molded wood flour/polypropylene composites incorporated with different contents of boron compounds; borax/boric acid and zinc borate, and phosphate compounds; mono and diammonium phosphates were investigated. The effect of the coupling agent content, maleic anhydride-grafted polypropylene, on the properties of...

  6. Significance of wood extractives for wood bonding.

    Science.gov (United States)

    Roffael, Edmone

    2016-02-01

    Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels.

  7. Visible-light activate Ag/WO3 films based on wood with enhanced negative oxygen ions production properties

    Science.gov (United States)

    Gao, Likun; Gan, Wentao; Cao, Guoliang; Zhan, Xianxu; Qiang, Tiangang; Li, Jian

    2017-12-01

    The Ag/WO3-wood was fabricated through a hydrothermal method and a silver mirror reaction. The system of visible-light activate Ag/WO3-wood was used to produce negative oxygen ions, and the effect of Ag nanoparticles on negative oxygen ions production was investigated. From the results of negative oxygen ions production tests, it can be observed that the sample doped with Ag nanoparticles, the concentration of negative oxygen ions is up to 1660 ions/cm3 after 60 min visible light irradiation. Moreover, for the Ag/WO3-wood, even after 60 min without irradiation, the concentration of negative oxygen ions could keep more than 1000 ions/cm3, which is up to the standard of the fresh air. Moreover, due to the porous structure of wood, the wood acted as substrate could promote the nucleation of nanoparticles, prevent the agglomeration of the particles, and thus lead the improvement of photocatalytic properties. And such wood-based functional materials with the property of negative oxygen ions production could be one of the most promising materials in the application of indoor decoration materials, which would meet people's pursuit of healthy, environment-friendly life.

  8. Factors affecting the accuracy of genomic selection for growth and wood quality traits in an advanced-breeding population of black spruce (Picea mariana).

    Science.gov (United States)

    Lenz, Patrick R N; Beaulieu, Jean; Mansfield, Shawn D; Clément, Sébastien; Desponts, Mireille; Bousquet, Jean

    2017-04-28

    Genomic selection (GS) uses information from genomic signatures consisting of thousands of genetic markers to predict complex traits. As such, GS represents a promising approach to accelerate tree breeding, which is especially relevant for the genetic improvement of boreal conifers characterized by long breeding cycles. In the present study, we tested GS in an advanced-breeding population of the boreal black spruce (Picea mariana [Mill.] BSP) for growth and wood quality traits, and concurrently examined factors affecting GS model accuracy. The study relied on 734 25-year-old trees belonging to 34 full-sib families derived from 27 parents and that were established on two contrasting sites. Genomic profiles were obtained from 4993 Single Nucleotide Polymorphisms (SNPs) representative of as many gene loci distributed among the 12 linkage groups common to spruce. GS models were obtained for four growth and wood traits. Validation using independent sets of trees showed that GS model accuracy was high, related to trait heritability and equivalent to that of conventional pedigree-based models. In forward selection, gains per unit of time were three times higher with the GS approach than with conventional selection. In addition, models were also accurate across sites, indicating little genotype-by-environment interaction in the area investigated. Using information from half-sibs instead of full-sibs led to a significant reduction in model accuracy, indicating that the inclusion of relatedness in the model contributed to its higher accuracies. About 500 to 1000 markers were sufficient to obtain GS model accuracy almost equivalent to that obtained with all markers, whether they were well spread across the genome or from a single linkage group, further confirming the implication of relatedness and potential long-range linkage disequilibrium (LD) in the high accuracy estimates obtained. Only slightly higher model accuracy was obtained when using marker subsets that were

  9. The Effect of Wood Alignment on Wood Grinding – Part 1: Properties of Pulp and Fines Revealed in the Grinding Mechanism

    Directory of Open Access Journals (Sweden)

    Erkki Tapani Saharinen

    2016-03-01

    Full Text Available In industrial wood grinding, logs are pressed against a rotating stone, with the logs and fiber axis parallel to the axis of the stone. The objective of this study is to clarify how the wood alignment affects the process and pulp properties. In this research, wood blocks were fed into a laboratory grinder with various alignments in relation to the surface of the grinding stone. The effects of the alignment on the properties of the pulp and the amount and quality of fines were measured. A grinding mechanism was proposed. The results show that the pulp quality is very sensitive to the angle between the stone surface and the log. In gentle refining, the fiber structure is loosened by fatigue before it is bent on the surface; pressure pulses produce fibrillar material, and fibers develop toward having good bonding ability. In forced grinding, the process is “violent”, and the fiber wears and becomes crushed immediately on the surface into small particles with low bonding ability.

  10. Effects of Different Wood Preservatives on The Some Physical Properties of Wood Species Used in Furniture and Building Industry

    Directory of Open Access Journals (Sweden)

    Abdi Atılgan

    2012-04-01

    Full Text Available This study aims to determine the combustion, density values of Fagus and Pinus sylvestris’ woods impregranted with Ammonium tetra fluoro borate (1 - 3 % and the mixture of cement and borax (6 % – 9 % according to ASTM-D 1413-76 standards. In the combustion test carried out according to ASTM-D 160-50, the combustion resulted from flame, the self-combustion and the combustion as glowing processes were completed and the amount of lux, combustion duration, decomposition and ash were determined. According to experimental results, it is determined that Fogus’ wood has the highest retention (42,43 kg/m3 in the mixture of cement and borax 9 %, combustion tempature (587 o C in the mixture of cement and borax 6 % , the value of lux (267 lux in the the combustion as glowing and Pinus sylvestris’ wood has the longest combustion duration (29,03 min. Ammonium tetrafluoro borate 1%, the most weight loss (94 %.

  11. Impact of Vertical Canopy Position on Leaf Spectral Properties and Traits across Multiple Species

    Directory of Open Access Journals (Sweden)

    Tawanda W. Gara

    2018-02-01

    Full Text Available Understanding the vertical pattern of leaf traits across plant canopies provide critical information on plant physiology, ecosystem functioning and structure and vegetation response to climate change. However, the impact of vertical canopy position on leaf spectral properties and subsequently leaf traits across the entire spectrum for multiple species is poorly understood. In this study, we examined the ability of leaf optical properties to track variability in leaf traits across the vertical canopy profile using Partial Least Square Discriminatory Analysis (PLS-DA. Leaf spectral measurements together with leaf traits (nitrogen, carbon, chlorophyll, equivalent water thickness and specific leaf area were studied at three vertical canopy positions along the plant stem: lower, middle and upper. We observed that foliar nitrogen (N, chlorophyll (Cab, carbon (C, and equivalent water thickness (EWT were higher in the upper canopy leaves compared with lower shaded leaves, while specific leaf area (SLA increased from upper to lower canopy leaves. We found that leaf spectral reflectance significantly (P ≤ 0.05 shifted to longer wavelengths in the ‘red edge’ spectrum (685–701 nm in the order of lower > middle > upper for the pooled dataset. We report that spectral bands that are influential in the discrimination of leaf samples into the three groups of canopy position, based on the PLS-DA variable importance projection (VIP score, match with wavelength regions of foliar traits observed to vary across the canopy vertical profile. This observation demonstrated that both leaf traits and leaf reflectance co-vary across the vertical canopy profile in multiple species. We conclude that canopy vertical position has a significant impact on leaf spectral properties of an individual plant’s traits, and this finding holds for multiple species. These findings have important implications on field sampling protocols, upscaling leaf traits to canopy level

  12. Analysis of Selected Properties of Fibreboard Panels Manufactured from Wood and Leather Using the Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Kerstin Wagner

    2015-01-01

    Full Text Available This paper deals with the characterization of the properties of wood fibres leather shavings composite board by using the near infrared spectroscopy (NIRS and multivariate data analysis. In this study fibreboards were manufactured with different leather amounts by using spruce fibres, as well as vegetable and mineral tanned leather shavings (wet white and wet blue. The NIR spectroscopy was used to analyse the raw materials as well as the wood leather fibreboards. Moreover, the physical and mechanical features of the wood leather composite fibreboards were determined to characterize their properties for the further data analysis. The NIR spectra were analysed by univariate and multivariate methods using the Principal Component Analysis (PCA and the Partial Least Squares Regression (PLSR method. These results demonstrate the potential of FT-NIR spectroscopy to estimate the physical and mechanical properties (e.g., bending strength. This phenomenon provides a possibility for quality assurance systems by using the NIRS.

  13. The Acoustic Properties of Water Submerged Lodgepole Pine (Pinus contorta and Spruce (Picea spp. Wood and Their Suitability for Use as Musical Instruments

    Directory of Open Access Journals (Sweden)

    Calvin Hilde

    2014-08-01

    Full Text Available Wood is a common material used for the manufacture of many products, and submerged wood, in particular, has been used in niche markets and musical instruments. In order to examine if submerged wood in British Columbia, Canada, would be appropriate for use as musical instruments, a study was performed in 2007 on submerged wood from Ootsa Lake, British Columbia, Canada. The results of that study showed the wood was not suitable for musical instruments. In this paper, the wood samples were allowed to age untouched in a laboratory setting and were then retested under the hypothesis that physical acoustic characteristics would improve. It was shown, however, that acoustic properties became less adequate after being left to dry over time. This article describes the density, speed of sound, acoustic constant and characteristic impedance properties for submerged wood and a comparison is made for different applications for musical instruments.

  14. Effects of Heat-Treated Wood Particles on the Physico-Mechanical Properties and Extended Creep Behavior of Wood/Recycled-HDPE Composites Using the Time–Temperature Superposition Principle

    Directory of Open Access Journals (Sweden)

    Teng-Chun Yang

    2017-03-01

    Full Text Available This study investigated the effectiveness of heat-treated wood particles for improving the physico-mechanical properties and creep performance of wood/recycled-HDPE composites. The results reveal that the composites with heat-treated wood particles had significantly decreased moisture content, water absorption, and thickness swelling, while no improvements of the flexural properties or the wood screw holding strength were observed, except for the internal bond strength. Additionally, creep tests were conducted at a series of elevated temperatures using the time–temperature superposition principle (TTSP, and the TTSP-predicted creep compliance curves fit well with the experimental data. The creep resistance values of composites with heat-treated wood particles were greater than those having untreated wood particles due to the hydrophobic character of the treated wood particles and improved interfacial compatibility between the wood particles and polymer matrix. At a reference temperature of 20 °C, the improvement of creep resistance (ICR of composites with heat-treated wood particles reached approximately 30% over a 30-year period, and it increased significantly with increasing reference temperature.

  15. Effects of Heat-Treated Wood Particles on the Physico-Mechanical Properties and Extended Creep Behavior of Wood/Recycled-HDPE Composites Using the Time–Temperature Superposition Principle

    Science.gov (United States)

    Yang, Teng-Chun; Chien, Yi-Chi; Wu, Tung-Lin; Hung, Ke-Chang; Wu, Jyh-Horng

    2017-01-01

    This study investigated the effectiveness of heat-treated wood particles for improving the physico-mechanical properties and creep performance of wood/recycled-HDPE composites. The results reveal that the composites with heat-treated wood particles had significantly decreased moisture content, water absorption, and thickness swelling, while no improvements of the flexural properties or the wood screw holding strength were observed, except for the internal bond strength. Additionally, creep tests were conducted at a series of elevated temperatures using the time–temperature superposition principle (TTSP), and the TTSP-predicted creep compliance curves fit well with the experimental data. The creep resistance values of composites with heat-treated wood particles were greater than those having untreated wood particles due to the hydrophobic character of the treated wood particles and improved interfacial compatibility between the wood particles and polymer matrix. At a reference temperature of 20 °C, the improvement of creep resistance (ICR) of composites with heat-treated wood particles reached approximately 30% over a 30-year period, and it increased significantly with increasing reference temperature. PMID:28772726

  16. Wood : adhesives

    Science.gov (United States)

    A.H. Conner

    2001-01-01

    This chapter on wood adhesives includes: 1) Classification of wood adhesives 2) Thermosetting wood adhesives 3) Thermoplastic adhesives, 4) Wood adhesives based on natural sources 5) Nonconventional bonding of wood 6) Wood bonding.

  17. Preparation and Flame Retardant and Smoke Suppression Properties of Bamboo-Wood Hybrid Scrimber Filled with Calcium and Magnesium Nanoparticles

    Directory of Open Access Journals (Sweden)

    Bin Fu

    2014-01-01

    Full Text Available The physical and mechanical properties of bamboo-wood hybrid scrimber filled with different loadings of nanoparticles were studied. The effects of nanoparticles on flame retardant and smoke suppression properties of bamboo-wood hybrid scrimber were studied by means of thermogravimetric analysis (TGA, cone calorimeter (CONE, and scanning electron microscope (SEM. The results showed that the physical and mechanical properties of bamboo-wood hybrid scrimber were improved by adding a moderate loading of nanoparticles; the optimal loading of nanoparticles was 10%. The heat transfer in bamboo-wood hybrid scrimber was prevented and the escaping channel of combustible gas was blocked by the uniformly filling effect of nanoparticles. The gas concentration was diluted by the noncombustible gas produced by pyrolysis of nanoparticles; the combustion chain reaction was suppressed by highly reactive free radicals produced by pyrolysis of nanoparticles. The residual mass of bamboo-wood hybrid scrimber filled with nanoparticles in thermogravimetric (TG curve at 900 s and burned by method of cone calorimeter (CONE at 600 s was increased compared to that of untreated one, which showed that inorganic mineral powder has the effect of catalytic charring.

  18. Phenotypic Data Collection and Sample Preparation for Genomics of Wood Formation and Cellulosic Biomass Traits in Sunflower: Ames, IA location.

    Energy Technology Data Exchange (ETDEWEB)

    Marek, Laura F.

    2011-06-17

    Three fields were planted in Ames in 2010, two association mapping fields, N3 and A, and a recombinant inbred line field, N13. Phenotype data and images were transferred to UGA to support genetic and genomic analyses of woody biomass-related traits.

  19. Influence of wood barrels classified by NIRS on the ellagitannin content/composition and on the organoleptic properties of wine.

    Science.gov (United States)

    Michel, Julien; Jourdes, Michael; Le Floch, Alexandra; Giordanengo, Thomas; Mourey, Nicolas; Teissedre, Pierre-Louis

    2013-11-20

    Ellagitannins are extracted from oak wood during wine aging in oak barrels. This research is based on the NIRS (Oakscan) oak wood classification according to their index polyphenolic (IP) (between 21.07 and 70.15). Their level in wood is very variable (between 5.95 and 32.91 mg/g dry wood) and influenced their concentration in red wine (between 2.30 and 32.56 mg/L after 24 months of aging) and thus their impact on wine organoleptic properties. The results show a good correlation between the NIRS classification and the chemical analysis (HPLC-UV-MS and acidic hydrolysis procedure) and with the wood ellagitannin level, the ellagitannin extraction kinetic, and the ellagitannins evolution in red wine (Cabernet Sauvignon). Moreover, a correlation between the NIRS classification and the increasing intensity of some wood aromas (woody, spicy, vanilla, and smoked/toasted), flavors (bitterness and astringency), and a decreasing intensity of fruitiness was also observed.

  20. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Energy Technology Data Exchange (ETDEWEB)

    Villasante, A.; Laina, R.; Rojas, J. A. M.; Rojas, I. M.; Vignote, S.

    2013-07-01

    Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strenght. Area of study: Spain. Material and methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601) and 50 with waterborne Copper Azole (Tanalith E 3492). 40 control samples were not treated (water or preservative). Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative. Main results: The results indicate that the treated wood (with either product) presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors. There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole. The most probable explanation for these results concerns changes in pressure during treatment. The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies. Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending and parallel compression strength. There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative. (Author)

  1. Properties of concretes and wood composites using a phosphate-based binder

    Science.gov (United States)

    Hong, Luong Thanh

    Magnesium potassium phosphate ceramics are from the family of phosphate-based cements which can be used as alternatives to Portland cements. In this study, concretes and wood composites were produced using magnesium potassium phosphate ceramic binders and supplementary materials including fly ash, sand, silica fume and sawdust. Bentonite, Delvo Stabilizer and baking soda were used as additives to increase the workability and the setting time of the fresh mixutres and decrease the density of the hardened products. The materials were then reinforced with chopped glass-fibers or textile glass-fabrics to increase their hardened properties. At 50% fly ash by total mass of the binder, the concretes had compressive strength and density of 33 MPa and 2170 kg/m3, respectively, after 90 days of simple curing. At 20% fly ash by total mass of the binder, the wood composites had compressive strength and density of 13 MPa and 1320 kg/m3, respectively, after 90 days. The flexural strengths were about 10% to 47% of the corresponding cylinder compressive strengths for these mixes. Increases in both compressive and flexural strengths for these mixes were observed with the addition of chopped glass-fibers or textile glass-fabrics.

  2. Correlation of water vapor adsorption behavior of wood with surface thermodynamic properties

    Science.gov (United States)

    Mandla A. Tshabalala; Agnes R. Denes; R. Sam. Williams

    1999-01-01

    To improve the overall performance of wood-plastic composites, appropriate technologies are needed to control moisture sorption and to improve the interaction of wood fiber with selected hydrophobic matrices. The objective of this study was to determine the surface thermodynamic characteristics of a wood fiber and to correlate those characteristics with the fiberas...

  3. Wood-plastic combination

    International Nuclear Information System (INIS)

    Schaudy, R.

    1978-02-01

    A review on wood-plastic combinations is given including the production (wood and plastic component, radiation hardening, curing), the obtained properties, present applications and prospects for the future of these materials. (author)

  4. Effect of Weathering Time on the Physical - Mechanical Properties and Color Change in Wood Flour/HDPE Composite

    Directory of Open Access Journals (Sweden)

    Behzad Kord

    2014-05-01

    Full Text Available This study was carried out to investigate the effect of weathering time on the physical and mechanical properties and color change in composite made of wood flour and high density polyethylene (HDPE. For this purpose, wood flour and polyethylene at a weight ratio of 60:40 with coupling agent were compounded in an internal mixer, and the samples were made in injection molding. Then, the weathering process by ultraviolet irradiation and water spray was done on the samples at different times of 250, 500, 1000 and 2000 hours in accelerated weathering apparatus. Finally, the physical and mechanical properties and color measurement of samples were tested, and compared with control samples. Results indicated that the flexural strength, flexural modulus, tensile strength and tensile modulus decreased with an increase in weathering time; however, the water absorption increased. Also, the yellowness of wood plastic samples decreased with an increase in weathering time and due to the lightness and color change increased.

  5. Variation of some wood macroscopic properties along the stem of Acacia melanoxylon R. Br. adult trees in Portugal

    Directory of Open Access Journals (Sweden)

    A. Santos

    2013-12-01

    Full Text Available Aim of the study: The aim of the study is to assess the variation of pith eccentricity, heartwood proportion, latewood percentage and basic wood density along the stem of 45-year-old A. melanoxylon trees collected in four sites of Portugal, and investigate the eventual relationship between these variables.Area of study: Sites covering littoral north, mid interior north and centre interior of Portugal.Materials and methods: Four sites and five trees per site were selected in the Acacia melanoxylon Portuguese forest.One wood sample at each of six height levels per tree was collected in order to evaluate its basic density, pith eccentricity, heartwood and latewood proportions.Main results: The high variability of the wood macroscopic properties among trees from the same site regarding to the variation of the corresponding average properties along the stem is a key characteristic of the experimental data.As a consequence, a multiple linear regression model tested was not able to properly explain the wood basic density variation of the 120 wood samples analysed. In spite of this, the following trends could be recognized: (i excluding the base level, wood basic density moderately increased with tree level; (ii latewood proportion followed similar behaviour; (iii pith eccentricity was low; (iv heartwood proportion decreased markedly with tree height, from 70% at the base to 7% at the top.Research highlights: The high basic density, the relatively low variability along the stem and the low pith eccentricity enable us to anticipate good performance as raw material for the wood industry.Key words: Acacia melanoxylon; basic density; earlywood; latewood; heartwood; sapwood; pith eccentricity.

  6. Broad Anatomical Variation within a Narrow Wood Density Range—A Study of Twig Wood across 69 Australian Angiosperms

    Science.gov (United States)

    Ziemińska, Kasia; Westoby, Mark; Wright, Ian J.

    2015-01-01

    Objectives Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Methods Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38–0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Results Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation. PMID:25906320

  7. Broad Anatomical Variation within a Narrow Wood Density Range--A Study of Twig Wood across 69 Australian Angiosperms.

    Science.gov (United States)

    Ziemińska, Kasia; Westoby, Mark; Wright, Ian J

    2015-01-01

    Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38-0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.

  8. Cavitation of intercellular spaces is critical to establishment of hydraulic properties of compression wood of Chamaecyparis obtusa seedlings.

    Science.gov (United States)

    Nakaba, Satoshi; Hirai, Asami; Kudo, Kayo; Yamagishi, Yusuke; Yamane, Kenichi; Kuroda, Katsushi; Nugroho, Widyanto Dwi; Kitin, Peter; Funada, Ryo

    2016-03-01

    When the orientation of the stems of conifers departs from the vertical as a result of environmental influences, conifers form compression wood that results in restoration of verticality. It is well known that intercellular spaces are formed between tracheids in compression wood, but the function of these spaces remains to be clarified. In the present study, we evaluated the impact of these spaces in artificially induced compression wood in Chamaecyparis obtusa seedlings. We monitored the presence or absence of liquid in the intercellular spaces of differentiating xylem by cryo-scanning electron microscopy. In addition, we analysed the relationship between intercellular spaces and the hydraulic properties of the compression wood. Initially, we detected small intercellular spaces with liquid in regions in which the profiles of tracheids were not rounded in transverse surfaces, indicating that the intercellular spaces had originally contained no gases. In the regions where tracheids had formed secondary walls, we found that some intercellular spaces had lost their liquid. Cavitation of intercellular spaces would affect hydraulic conductivity as a consequence of the induction of cavitation in neighbouring tracheids. Our observations suggest that cavitation of intercellular spaces is the critical event that affects not only the functions of intercellular spaces but also the hydraulic properties of compression wood. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Production of wood plastic properties using gamma radiation as a polymerization agent

    Energy Technology Data Exchange (ETDEWEB)

    Bull, C; Rosende, R [Chile Univ., Santiago. Dept. de Tecnologia de la Madera; Espinoza B, J; Figueroa C, C [Comision Chilena de Energia Nuclear, Santiago. Dept. de Aplicaciones de los Isotopos y Radiaciones

    1984-04-01

    The properties of wood plastic composites (WPC) based on Pinus Radiata D. Don impregnated with methylmethacrylate and subsequently polymerized with gamma radiation were studied. Different systems of impregnation were utilized, in order to obtain partial and shell loads. The minimum irradiation dose uses was 16 kGy. The following tests were made to the material: static bending, compression strenght parallel to grain, hardness, sheer strength, toughness, water absorption, dimensional stability and flame propagation index. To evaluate the testing, the results of the samples were separated according final density in the ranges: R/sub 1/ = 429-483 kg/m3 (without treatment); R/sub 2/ = 500-650 kg/m3 and R3 = 651-850 kg/m3. In general, the best results were obtained for samples of high density. The most important results were achieved for dimensional stability, water absorption and hardness.

  10. Soil Properties Control Glyphosate Sorption in Soils Amended with Birch Wood Biochar

    DEFF Research Database (Denmark)

    Kahawaththa Gamage, Inoka Damayanthi Kumari; Moldrup, Per; Paradelo, Marcos

    2016-01-01

    Abstract Despite a contemporary interest in biochar application to agricultural fields to improve soil quality and long-term carbon sequestration, a number of potential side effects of biochar incorporation in field soils remain poorly understood, e.g., in relation to interactions...... with agrochemicals such as pesticides. In a fieldbased study at two experimental sites in Denmark (sandy loam soils at Risoe and Kalundborg), we investigated the influence of birch wood biochar with respect to application rate, aging (7–19 months), and physico- chemical soil properties on the sorption coefficient......, Kd (L kg−1), of the herbicide glyphosate. We measured Kd in equilibrium batch sorption experiments with triplicate soil samples from 20 field plots that received biochar at different application rates (0 to 100 Mg ha−1). The results showed that pure biochar had a lower glyphosate Kd value as compared...

  11. Production of wood plastic properties using gamma radiation as a polimerization agent

    International Nuclear Information System (INIS)

    Bull, C.; Rosende, R.; Espinoza B, J.; Figueroa C, C.

    1984-01-01

    The properties of wood plastic composites (WPC) based on Pinus Radiata D. Don impregnated with methylmethacrylate and subsequently polymerized with gamma radiation were studied. Different systems of impregnation were utilized, in order to obtain partial and shell loads. The minimum irradiation dose uses was 16 kGy. The following tests were made to the material: static bending, compression strenght parallel to grain, hardness, sheer strength, toughness, water absorption, dimensional stability and flame propagation index. To evaluate the testing, the results of the samples were separated according final density in the ranges: R 1 = 429-483 kg/m3 (without treatment); R 2 = 500-650 kg/m3 and R3 = 651-850 kg/m3. In general, the best results were obtained for samples of high density. The most important results were achieved for dimensional stability, water absorption and hardness. (Author)

  12. Internal properties assessment in agar wood trees using ultrasonic velocity measurement

    International Nuclear Information System (INIS)

    Mohd Noorul Ikhsan Mohamed; Mohamad Pauzi Ismail; Mat Rasol Awang; Mohd Fajri Osman; Fakhruzi, M.; Hashim, M.M.

    2010-01-01

    This paper presents the application of ultrasonic velocity in agar wood trees (Aquilaria crassna) with the purpose of evaluating the relationship of the ultrasonic velocity to the variations of internal properties of trees. In this study, three circular cross-sectional discs from the freshly cut tree were selected as samples. First sample with a big hole (decay) in the middle, second sample with internal resinous and the last one is the sample with no defects. The through transmission ultrasonic testing method was carried out using Tico ultrasonic pulse velocity tester which is from Switzerland. Two-dimensional image of internal properties evaluation by an ultrasonic investigation was obtained using Matlab. The results showed that the ultrasonic wave cannot pass through the internal decay or resinous so that the wave went round it and thus ultrasonic wave velocity significantly decreased by increasing the hole or resinous. The difference in color of the image generated by Matlab software based on variation of ultrasonic velocity between the internal decay area and its surrounding area was obvious. Therefore, the properties of internal properties of the three could be detected by ultrasonic line imaging technique. (author)

  13. Effects of soil properties on food web accumulation of heavy metals to the wood mouse (Apodemus sylvaticus)

    NARCIS (Netherlands)

    Brink, van den N.W.; Lammertsma, D.R.; Dimmers, W.J.; Boerwinkel, M.C.; Hout, van der A.

    2010-01-01

    Effects of soil properties on the accumulation of metals to wood mice (Apodemus sylvaticus) were evaluated at two sites with different pH and organic matter content of the soil. pH and organic matter content significantly affected accumulation of Cd, Cu, Pb and Zn in earthworms and vegetation. For

  14. The Effect of Carbon Nanotubes on the Mechanical Properties of Wood Plastic Composites by Selective Laser Sintering

    Directory of Open Access Journals (Sweden)

    Yunhe Zhang

    2017-12-01

    Full Text Available Wood-plastic composites (WPCs made by selective laser sintering (SLS approach of 3D printing offer many advantages over single polymer materials, such as low cost, sustainability, and better sintering accuracy. However, WPCs made via SLS are too weak to have widespread applications. In order to increase the mechanical properties of WPCs, a novel type of WPCs containing 0, 0.05, 0.1 and 0.15 wt % carbon nanotubes (CNT, 14 wt % wood fibers, 86 wt % polyether sulfone (PES was manufactured via SLS. The experimental results showed that the addition of small amount of CNTs can significantly increase the mechanical properties of the wood/PES composite material. The tensile strength, bending strength, and elasticity modulus were 76.3%, 227.9%, and 128.7% higher with 0.1 wt % CNTs than those without CNTs. The mechanical properties of specimens first increased and then decreased with the addition of CNTs. The SEM results of the specimens’ fracture morphology indicate that the preferable bonding interfaces between wood flour grains and PES grains were achieved by adding CNTs to the composites. There are two reasons why the composites possessed superior mechanical properties: CNTs facilitate the laser sintering process of WPCs due to their thermal conductivities, and CNTs directly reinforce WPCs.

  15. Ignition and flame spread properties of wood, elaborated during a new test method based on convective heat flux

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt; Poulsen, Annemarie

    2007-01-01

    Ignition and flame spread properties on selected types of wood are elaborated. The tests are established in a new test setup in which the test specimen can be fixed in different angles due to a horizontal level. The heat exposing the test objects is arranged as a convective flux. This principle...

  16. Dynamic mechanical analysis of compatibilizer effect on the mechanical properties of wood flour/high-density polyethylene composites

    Science.gov (United States)

    Mehdi Behzad; Medhi Tajvidi; Ghanbar Ehrahimi; Robert H. Falk

    2004-01-01

    In this study, effect of MAPE (maleic anhydride polyethylene) as the compatibilizer on the mechanical properties of wood-flour polyethylene composites has been investigated by using Dynamic Mechanical Analysis (DMA). Composites were made at 25% and 50% by weight fiber contents and 1% and 2% compatibilizer respectively. Controls were also made at the same fiber contents...

  17. Effects of long-term ambient ozone exposure on biomass and wood traits in poplar treated with ethylenediurea (EDU)

    International Nuclear Information System (INIS)

    Carriero, G.; Emiliani, G.; Giovannelli, A.; Hoshika, Y.; Manning, W.J.; Traversi, M.L.; Paoletti, E.

    2015-01-01

    This is the longest continuous experiment where ethylenediurea (EDU) was used to protect plants from ozone (O 3 ). Effects of long-term ambient O 3 exposure (23 ppm h AOT40) on biomass of an O 3 sensitive poplar clone (Oxford) were examined after six years from in-ground planting. Trees were irrigated with either water or 450 ppm EDU. Above (−51%) and below-ground biomass (−47%) was reduced by O 3 although the effect was significant only for stem and coarse roots. Ambient O 3 decreased diameter of the lower stem, and increased moisture content along the stem of not-protected plants (+16%). No other change in the physical wood structure was observed. A comparison with a previous assessment in the same experiment suggested that O 3 effects on biomass partitioning to above-ground organs depend on the tree ontogenetic stage. The root/shoot ratios did not change, suggesting that previous short-term observations of reduced allocation to tree roots may be overestimated. - Highlights: • 6-y ambient O 3 exposure was investigated in a sensitive poplar clone. • EDU irrigation protected poplar against ambient O 3 exposure. • O 3 reduced biomass of roots and stem, but did not change biomass allocation. • O 3 decreased stem diameter only in the lower third of the stem. • O 3 increased moisture content of the wood along the stem. - Ozone exposure reduced lateral branching, leaves and roots in younger trees, and affected stem and roots in older trees, while shoot/root ratios did not change.

  18. Mechanical properties of wood from Pinus sylvestris L. treated with Light Organic Solvent Preservative and with waterborne Copper Azole

    Directory of Open Access Journals (Sweden)

    A.M. Villasante

    2013-12-01

    Full Text Available Aim of study: To determine the effect on wood from Pinus sylvestris of treatment with preservatives on mechanical properties and to establish the relation between the penetration and compression strength.Area of study: SpainMaterial and Methods: 40 samples of defect-free wood from Pinus sylvestris L. were treated with Light Organic Solvent Preservative (Vacsol Azure WR 2601 and 50 with waterborne Copper Azole (Tanalith E 3492. 40 control samples were not treated (water or preservative. Mechanical resistance to static bending, modulus of elasticity and compression strength parallel to the grain were compared with untreated wood. Regression analysis between the penetration and compression strength parallel was done with the samples treated with waterborne preservative.Main results: The results indicate that the treated wood (with either product presents a statistically significant increase in mechanical resistance in all three mechanical characteristics. The results obtained differ from earlier studies carried out by other authors.There was no correlation between parallel compression strength and the degree of impregnation of the wood with waterborne Copper Azole . The most probable explanation for these results concerns changes in pressure during treatment.The use of untreated control samples instead of samples treated only with water is more likely to produce significant results in the mechanical resistance studies.Research highlights: Treated wood presents a statistically significant increase in MOE, modulus of rupture to static bending  and parallel compression strength.There was no correlation between parallel compression strength and the degree of impregnation with waterborne preservative.Keywords: Light Organic Solvent Preservative; MOE; parallel compression; static bending; waterborne Copper Azole; wood technology.

  19. A NOVEL FIRE RETARDANT AFFECTS FIRE PERFORMANCE AND MECHANICAL PROPERTIES OF WOOD FLOUR-HIGH DENSITY POLYETHYLENE COMPOSITES

    Directory of Open Access Journals (Sweden)

    Mingzhu Pan,

    2012-02-01

    Full Text Available Wood flour-high density polyethylene (HDPE composites were prepared to investigate the effects of ammonium polyphosphate based fire retardant content (2, 4, 6, 8, and 10-wt%, on the flammability, mechanical, and morphological properties of the wood flour-HDPE composites in this study. Cone calorimetry analysis showed that the addition of fire retardant could decrease the heat release rate (HRR and total smoke release of wood flour-HDPE composites, while it had no obviously effects on effective heat of combustion. Most of the decrease of the HRR occurred with the concentration of the fire retardant up to 4-wt%. With addition of fire retardant, the composites showed a decrease in tensile elongation at break and impact strength, and had no obvious effect on tensile and flexural strength. The scanning electron microscopy observation on the fracture surface of the composites indicated that fire retardant had a uniform dispersion in the wood flour-HDPE composites. However, interfacial bonding would be suggested to improve in wood flour-HDPE composites with ammonium polyphosphate based fire retardant.

  20. Self-ignition Properties of Peat, Palm Shell Fibre and Woods

    Directory of Open Access Journals (Sweden)

    Yulianto Sulistyo Nugroho

    2010-10-01

    Full Text Available Forest fire is one of the greatest environmental problems faced by Indonesia. Forest fires have destroyed million hectares of forest and land which cause economic loss, social problems including smoke related diseases and environmental disaster with long time consequences. The exothermic reactions of forest fuels that lead to fire can be initiated by a piloted flame and low-temperature oxidation mechanism. This paper presents the results of low temperature oxidation studies using forests fuel samples i.e. palm shell fibre, peat, woods and low-rank coal. The measured values of the critical oven temperatures and the kinetic oxidation parameters are used to analyze the intrinsic properties of the samples to self-ignite. Thermal runaway reactions leading to ignition are indicated for all forest fuels tested. This reaction is affected by various factors including oven temperature, moisture content, chemical and physical properties as well as basket sizes. Attempt to extrapolate the results of these laboratoryscaled experiments for real fires still require further tests and assessments.

  1. EFFECT OF FERTILIZATION ON MECHANICAL PROPERTIES OF THE WOOD OF Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Israel Luiz de Lima

    2011-09-01

    Full Text Available The effect of the fertilization in the amount and quality of the produced wood is one of the questions to be considered in the research of the Eucalyptus grandis. The present work aimed to evaluate the fertilization effect in the mechanical properties of Eucalyptus grandis. The population of Eucalyptus grandis was 21 years old and was managed under the system of selective thinning, with application of fertilizers. The factors used in this study were: presence or absence of fertilizers, two positions of log and five radial positions. The influences of the factors and of their combinations were evaluated regarding to compression strength, shear strength, modulus of rupture and modulus of elasticity in static banding. The compressive strength and the modulus of elasticity had been influenced by the factors: fertilizer and radial positions of the log. There was also an increase in the direction of the pith-bark in all studied properties. A good positive relationship was found to exist among the compression strength, the shear, the modulus of rupture and the modulus of elasticity with radial position.

  2. Influence of Maleic Anhydride/Glycidyl Methacrylate Cografted Polylactic Acid on Properties of Wood Flour/PLA Composites

    Directory of Open Access Journals (Sweden)

    DU Jun

    2017-12-01

    Full Text Available Graft copolymers of PLA-g-MAH, PLA-g-GMA and PLA-co-MAH/GMA were prepared by means of melt grafting. The structure of the graft copolymers were characterized by FTIR.Wood flour/PLA composites were prepared by injection molding with three kinds of graft copolymers as compatibilizers, and the fractured morphology of composites was investigated by scanning electron microscope (SEM. Results show that there is no obvious phase interface between wood flour and PLA,which indicating the interfacial compatibility of wood flour/PLA composites is improved after adding different graft copolymers. The determination results of mechanical properties, processing flowability and dynamic rheological property of composites prepared with different graft copolymers reveal that, compared to the composite without compatibilizer, the tensile strength and impact strength of wood flour/PLA composites are increased by 9.54% and 7.23% respectively, and the equilibrium torque, shear heat, storage modulus and complex viscosity are all increased after adding maleic anhydride/glycidyl methacrylate cografted polylactic acid.

  3. RNA-Seq using two populations reveals genes and alleles controlling wood traits and growth in Eucalyptus nitens.

    Directory of Open Access Journals (Sweden)

    Saravanan Thavamanikumar

    Full Text Available Eucalyptus nitens is a perennial forest tree species grown mainly for kraft pulp production in many parts of the world. Kraft pulp yield (KPY is a key determinant of plantation profitability and increasing the KPY of trees grown in plantations is a major breeding objective. To speed up the breeding process, molecular markers that can predict KPY are desirable. To achieve this goal, we carried out RNA-Seq studies on trees at extremes of KPY in two different trials to identify genes and alleles whose expression correlated with KPY. KPY is positively correlated with growth measured as diameter at breast height (DBH in both trials. In total, six RNA bulks from two treatments were sequenced on an Illumina HiSeq platform. At 5% false discovery rate level, 3953 transcripts showed differential expression in the same direction in both trials; 2551 (65% were down-regulated and 1402 (35% were up-regulated in low KPY samples. The genes up-regulated in low KPY trees were largely involved in biotic and abiotic stress response reflecting the low growth among low KPY trees. Genes down-regulated in low KPY trees mainly belonged to gene categories involved in wood formation and growth. Differential allelic expression was observed in 2103 SNPs (in 1068 genes and of these 640 SNPs (30% occurred in 313 unique genes that were also differentially expressed. These SNPs may represent the cis-acting regulatory variants that influence total gene expression. In addition we also identified 196 genes which had Ka/Ks ratios greater than 1.5, suggesting that these genes are under positive selection. Candidate genes and alleles identified in this study will provide a valuable resource for future association studies aimed at identifying molecular markers for KPY and growth.

  4. Photostability and moisture uptake properties of wood veneers coated with a combination of thin sol-gel films and light stabilizers

    Science.gov (United States)

    Mandla A. Tshabalala; Ryan Libert; Christian M. Schaller

    2011-01-01

    In recent years, there has been increased interest in the use of inorganic UV blocking nanoparticles for photostabilization of wood surfaces. Photostability and moisture uptake properties of wood veneers coated with a combination of hybrid inorganic-organic thin sol-gel films and organic light stabilizers was investigated. The light stabilizers were applied by brushing...

  5. Effect of thermo-mechanical refining pressure on the properties of wood fibers as measured by nanoindentation and atomic force microscopy

    Science.gov (United States)

    Cheng Xing; Siqun Wang; George M. Pharr; Leslie H. Groom

    2008-01-01

    Refined wood fibers of a 54-year-old loblolly pine (Pinus taeda L.) mature wood were investigated by nanoindentation and atomic force microscopy (AFM). The effect of steam pressure, in the range of 2?18 bar, during thermomechanical refining was investigated and the nanomechanical properties and nano- or micro-level damages of the cell wall were...

  6. Physical properties and consumer reaction to use of compressed wood bricks in southeast Alaska

    Science.gov (United States)

    Allen M. Brackley; Robert Gorman; Karen. Peterson

    2012-01-01

    In late 2008, a group of business people and entrepreneurs in southeast Alaska became aware of a compressed wood brick product that could be used as an alternative fuel in existing wood-burning stoves and heating equipment. The product differed from many others on the market in that it contained no additive to promote binding and burn characteristics. In 2009, local...

  7. Physical and mechanical properties of flakeboard produced from recycled CCA-treated wood

    Science.gov (United States)

    W. Li; T.F. Shupe; Chung-Yun Hse

    2004-01-01

    Chromated copper arsenate (CCA) treated wood has been most widely used in North America since the 1970s for many exterior applications such as decks, fences, playground equipment, utility poles, and others. A large volume of CCA-treated wood is currently coming out of service. Traditional disposal methods such as landfilling and incineration are not without adverse...

  8. Physical properties of wood-polymer composites prepared by an electron beam accelerator

    International Nuclear Information System (INIS)

    Yoshizawa, S.; Handa, T.; Fukuoka, M.; Hashizume, Y.; Nakamura, T.

    1981-01-01

    The dual characteristics in the performance of polymers in wood-polymer composites systems have been pursued with regard to the resolution of mechanical anisotropy of wood and the improvement in dimensional stability. The objective of the present study is to pursue the polymerization mechanism in wood under electron beam irradiation and the temperature dependence of polymer-wood interactions induced at various levels of higher order structure of wood in order to understand the polymer performance. Veneers used in the study were of rotary-cut beech (Fagus crenata Blume) 0.65 mm thick. All samples were oven-dried in vacuo at 80 0 C for 30 hr. The monomers used in the study were methyl methacrylate, styrene, acrylic acid, acrylonitrile, and unsaturated polyester. Experimental details are given. Results are given and discussed. (U.K.)

  9. Perceived emotional intelligence in nursing: psychometric properties of the Trait Meta-Mood Scale.

    Science.gov (United States)

    Aradilla-Herrero, Amor; Tomás-Sábado, Joaquín; Gómez-Benito, Juana

    2014-04-01

    To examine the psychometric properties of the Trait Meta-Mood Scale in the nursing context and to determine the relationships between emotional intelligence, self-esteem, alexithymia and death anxiety. The Trait Meta-Mood Scale is one of the most widely used self-report measures for assessing perceived emotional intelligence. However, in the nursing context, no extensive analysis has been conducted to examine its psychometric properties. Cross-sectional and observational study. A total of 1417 subjects participated in the study (1208 nursing students and 209 hospital nurses). The Trait Meta-Mood Scale, the Toronto Alexithymia Scale, the Rosenberg Self-Esteem Scale and the Death Anxiety Inventory were all applied to half of the sample (n = 707). A confirmatory factor analysis was carried out, and statistical analyses examined the internal consistency and test-retest reliability of the Trait Meta-Mood Scale, as well as its relationship with relevant variables. Confirmatory factor analysis confirmed the three dimensions of the original scale (Attention, Clarity and Repair). The instrument showed adequate internal consistency and temporal stability. Correlational results indicated that nurses with high scores on emotional Attention experience more death anxiety, report greater difficulties identifying feelings and have less self-esteem. By contrast, nurses with high levels of emotional Clarity and Repair showed less death anxiety and higher levels of self-esteem. The Trait Meta-Mood Scale is an effective, valid and reliable tool for measuring perceived emotional intelligence in the nursing context. Training programmes should seek to promote emotional abilities among nurses. Use of the Trait Meta-Mood Scale in the nursing context would provide information about nurses' perceived abilities to interpret and manage emotions when interacting with patients. © 2013 John Wiley & Sons Ltd.

  10. A comparative study on the properties of graphene oxide and activated carbon based sustainable wood starch composites.

    Science.gov (United States)

    Baishya, Prasanta; Maji, Tarun Kumar

    2018-08-01

    Activated carbon (AC) prepared from Jatropha curcas and graphene oxide (GO) were employed in the preparation of natural polymer based wood starch composites (WSC) through the solution blending technique using water as a solvent. In this study, methyl methacrylate (MMA) was grafted onto the starch polymer and this MMA grafted starch (MMA-g-starch) was cross-linked with the cheap soft wood flour using the citric acid as cross-linker and water as a solvent in the whole process. The prepared GO and AC were characterized through Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA) and Raman study. The interaction of GO and AC, with MMA-g-starch, citric acid and wood were studied by FTIR, XRD and SEM analysis. The GO and AC treated composites exhibited outstanding mechanical properties, thermal stability and fire resistance properties. The tensile strength of the composites increased by 178% and 200% with addition of 2 phr AC and GO respectively compared to untreated composites. A significant enhancement in water resistance properties of GO and AC treated composites was also attained. The study showed that the properties of the composites containing AC prepared from the seeds of Jatropha curcas was quite comparable with the composites reinforced with GO. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Specific features of the electrical properties in partially graphitized porous biocarbons of beech wood

    Science.gov (United States)

    Popov, V. V.; Orlova, T. S.; Gutierrez-Pardo, A.; Ramirez-Rico, J.

    2015-09-01

    The electrical and galvanomagnetic properties of partially graphitized highly porous bioC(Ni) biocarbon matrices produced by pyrolysis (carbonization) of beech wood at temperatures T carb = 850-1600°C in the presence of a Ni-containing catalyst have been studied in comparison with their microstructural features. The temperature dependences of the resistivity, the magnetoresistance, and the Hall coefficient have been measured in the temperature range of 4.2-300 K in magnetic fields to 28 kOe. It has been shown that an additional graphite phase introduction into samples with T carb ≥ 1000°C results in an increase in the carrier mobility by a factor of 2-3, whereas the carrier (hole) concentration remains within ~1020 cm-3, as in biocarbons obtained without catalyst. An analysis of experimental data has demonstrated that the features of the conductivity and magnetoresistance of these samples are described by quantum corrections related to their structural features, i.e., the formation of a globular graphite phase of nano- and submicrometer sizes in the amorphous matrix. The quantum corrections to the conductivity decrease with increasing carbonization temperature, which indicates an increase in the degree of structure ordering and is in good agreement with microstructural data.

  12. Anti-Melanogenic Properties of Greek Plants. A Novel Depigmenting Agent from Morus alba Wood.

    Science.gov (United States)

    Chaita, Eliza; Lambrinidis, George; Cheimonidi, Christina; Agalou, Adamantia; Beis, Dimitris; Trougakos, Ioannis; Mikros, Emmanuel; Skaltsounis, Alexios-Leandros; Aligiannis, Nektarios

    2017-03-23

    In therapeutic interventions associated with melanin hyperpigmentation, tyrosinase is regarded as a target enzyme as it catalyzes the rate-limiting steps in mammalian melanogenesis. Since many known agents have been proven to be toxic, there has been increasing impetus to identify alternative tyrosinase inhibitors, especially from natural sources. In this study, we investigated 900 extracts from Greek plants for potential tyrosinase inhibitive properties. Among the five most potent extracts, the methanol extract of Morus alba wood (MAM) demonstrated a significant reduction in intracellular tyrosinase and melanin content in B16F10 melanoma cells. Bioassay-guided isolation led to the acquisition of twelve compounds: oxyresveratrol (1), kuwanon C (2), mulberroside A (3), resorcinol (4), dihydrooxyresveratol (5), trans-dihydromorin (6), 2,4,3'-trihydroxydihydrostilbene (7), kuwanon H (8), 2,4-dihydroxybenzaldehyde (9), morusin (10), moracin M (11) and kuwanon G (12). Among these, 2,4,3'-trihydroxydihydrostilbene (7) is isolated for the first time from Morus alba and constitutes a novel potent tyrosinase inhibitor (IC50 0.8 ± 0.15). We report here for the first time dihydrooxyresveratrol (5) as a potent natural tyrosinase inhibitor (IC50 0.3 ± 0.05). Computational docking analysis indicated the binding modes of six tyrosinase inhibitors with the aminoacids of the active centre of tyrosinase. Finally, we found both MAM extract and compounds 1, 6 and 7 to significantly suppress in vivo melanogenesis during zebrafish embryogenesis.

  13. Tensile and impact properties of three-component PP/wood/elastomer composites

    Directory of Open Access Journals (Sweden)

    B. Pukanszky

    2012-03-01

    Full Text Available Polypropylene (PP was reinforced with wood flour and impact modified with elastomers to increase stiffness and impact resistance simultaneously. Elastomer content changed in four (0, 5, 10 and 20 wt%, while that of wood content in seven steps, the latter from 0 to 60 wt% in 10 wt% steps. Structure and adhesion were controlled by the addition of functionalized (maleated polymers. Composites were homogenized in a twin-screw extruder and then injection molded to tensile bars. Fracture resistance was characterized by standard and instrumented impact tests. The results showed that the components are dispersed independently of each other even when a functionalized elastomer is used for impact modification, at least under the conditions of this study. Impact resistance does not change much as a function of wood content in PP/wood composites, but decreases drastically from the very high level of the PP/elastomer blend to almost the same value obtained without impact modifier in the three-component materials. Increasing stiffness and fiber related local deformation processes led to small fracture toughness at large wood content. Micromechanical deformation processes depend mainly on the strength of PP/wood interaction; debonding and pull-out take place at poor adhesion, while fiber fracture dominates when adhesion is strong. Composites with sufficiently large impact resistance cannot be prepared in the usual range of wood contents (50–60 wt%.

  14. Method to estimate the internal stresses due to moisture in wood using transmission properties of microwaves

    International Nuclear Information System (INIS)

    Takemura, T.; Taniguchi, T.

    2004-01-01

    The purpose of this paper is to offer a new method for detecting stress in wood due to moisture along the lines of a theory reported previously. According to the theory, the stress in wood could be estimated from the moisture content of the wood and the power voltage of a microwave moisture meter (i.e., attenuation of the projected microwave). This seems to suggest a possibility of utilizing microwaves in the field of stress detection. To develop such an idea, the stress formulas were initially modified to the form of an uni-variable function of power voltage, and the application method of the formulas to detection was tried. Finally, these results were applied to the data of sugi (Cryptomeria japonica) lumber in the previous experiment. The estimated strains showed fairly good agreement with those observed. It could be concluded from this study that the proposed method might be available for detecting stress in wood due to moisture

  15. Influence of Heartwood on Wood Density and Pulp Properties Explained by Machine Learning Techniques

    Directory of Open Access Journals (Sweden)

    Carla Iglesias

    2017-01-01

    Full Text Available The aim of this work is to develop a tool to predict some pulp properties e.g., pulp yield, Kappa number, ISO brightness (ISO 2470:2008, fiber length and fiber width, using the sapwood and heartwood proportion in the raw-material. For this purpose, Acacia melanoxylon trees were collected from four sites in Portugal. Percentage of sapwood and heartwood, area and the stem eccentricity (in N-S and E-W directions were measured on transversal stem sections of A. melanoxylon R. Br. The relative position of the samples with respect to the total tree height was also considered as an input variable. Different configurations were tested until the maximum correlation coefficient was achieved. A classical mathematical technique (multiple linear regression and machine learning methods (classification and regression trees, multi-layer perceptron and support vector machines were tested. Classification and regression trees (CART was the most accurate model for the prediction of pulp ISO brightness (R = 0.85. The other parameters could be predicted with fair results (R = 0.64–0.75 by CART. Hence, the proportion of heartwood and sapwood is a relevant parameter for pulping and pulp properties, and should be taken as a quality trait when assessing a pulpwood resource.

  16. Changes in vibrational properties of coated wood through ti me from application of varnish, with recipes used in European or Iranian string instruments making

    OpenAIRE

    Brémaud , Iris; Karami , Elham; Bardet , Sandrine; Gilles , Nicolas; Perego , François; Zare , Samad; Gril , Joseph ,

    2016-01-01

    International audience; The influence of vanishing process on the vibrational properties of the wood+coating systems was studied using different types and recipes of instrument making varnishes, used in traditional Iranian string instruments making, or in European violin-quartet making. The focus is on the time evolution of these properties, that can be involved in the changing behaviour of newly made instruments. The different tested varnishes recipes were applied on wood representative of e...

  17. Ignition and flame spread properties of wood, elaborated during a new test method based on convective heat flux

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    Ignition and flame spread properties on selected types of wood and wall papers are elaborated. Tests are established in a new test setup in which the test specimen can be fixed in different angles due to a horizontal level. The heat exposing the test objects is arranged as a convective flux......, established from a Bunsen burners pilot flame. This principal is somewhat in contrast to the more typical radiation established fluxes. For instance, the ISO 9239 (DS 2000) test method is based on a gas fired radiant panel. And in the ISO 5657 standard, the ignition properties are investigated on test...

  18. Electron beam processing of rubber wood fibers - polypropylene composites. Effects of reactive additives on the physical and mechanical properties

    International Nuclear Information System (INIS)

    Nor Yuziah Mohd Yunus; Jalaluddin Harun; Khairul Zaman

    2000-01-01

    The purpose of this study is to determine the suitability of producing agro-fiber reinforced plastic composite (agro-FRPC) from rubber wood fiber blended in polypropylene matrix. The effects of varying fiber dimension and fiber content on the physical and mechanical properties of the composite were evaluated to provide an insight into the fiber matrix adhesion. The effects of reactive additives on the physical and mechanical properties of the composite were evaluated which provides the insight on the reinforcement of the composite. Rubber wood fiber used in this study is currently being used in the manufacturing of medium density fiber (MDF) board. Two sizes of rubber wood fiber were used i.e. 0.5-1.0 mm and 1.0-2.0 mm. Homopolymer polypropylene of MFI 14.0 was used as a matrix. The irradiation work was carried out using electron beam accelerator, 3.0 MeV, 3.0 mA. Various types of reactive additives (RA) with mono-functional, di-functional, tri-functional and oligomer were applied in the blend. For comparison, a conventional chemical cross-linking using two types of maleated polypropylene, MPA (Mw=9,000) and PMAP (Mw=220,000) were also performed. (author)

  19. Structures and electrochemical properties of pyrolytic carbon films infiltrated from gas phase into electro-conductive substrates derived from wood

    International Nuclear Information System (INIS)

    Ohzawa, Yoshimi; Mitani, Masami; Li, Jianling; Nakajima, Tsuyoshi

    2004-01-01

    Using the pressure-pulsed chemical vapor infiltration technique, pyrolytic carbon (pyrocarbon) films were deposited into two sorts of conductive porous substrates, that is, the carbonized wood (A) and the TiN-coated wood (B). Structures and electrochemical properties were investigated as the negative electrodes of lithium-ion secondary battery. The electrodes had the three-dimensionally continuous current paths in the pyrocarbon-based anodes without the organic binders and the additional conductive fillers. The pyrocarbon films adhered tightly to the carbonized wood or TiN as current collector. These macro-structures of electrodes were effective in improving the high rate property. The sort of substrates affected the nano-structure of pyrocarbon. The pyrocarbon in sample (A) had the relatively high crystallinity, whereas the pyrocarbon in sample (B) was disordered. The capacity of pyrocarbon in sample (B) was higher than that of sample (A), reflecting the disordered microstructure of pyrocarbon film (B). However, sample (A) showed higher Coulombic efficiency at first cycle (i.e. 87%) than that of sample (B), which would result from the high crystallinity, laminar microstructure and low surface area of pyrocarbon in sample (A)

  20. Electron beam processing of rubber wood fibers - polypropylene composites. Effects of reactive additives on the physical and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Nor Yuziah Mohd Yunus; Jalaluddin Harun [Universiti Putra Malaysia, Selangor Darul Ehsan (Malaysia); Khairul Zaman [Malaysian Institute for Nuclear Technology Research (MINT), Selangor Darul Ehsan (Malaysia)

    2000-07-01

    The purpose of this study is to determine the suitability of producing agro-fiber reinforced plastic composite (agro-FRPC) from rubber wood fiber blended in polypropylene matrix. The effects of varying fiber dimension and fiber content on the physical and mechanical properties of the composite were evaluated to provide an insight into the fiber matrix adhesion. The effects of reactive additives on the physical and mechanical properties of the composite were evaluated which provides the insight on the reinforcement of the composite. Rubber wood fiber used in this study is currently being used in the manufacturing of medium density fiber (MDF) board. Two sizes of rubber wood fiber were used i.e. 0.5-1.0 mm and 1.0-2.0 mm. Homopolymer polypropylene of MFI 14.0 was used as a matrix. The irradiation work was carried out using electron beam accelerator, 3.0 MeV, 3.0 mA. Various types of reactive additives (RA) with mono-functional, di-functional, tri-functional and oligomer were applied in the blend. For comparison, a conventional chemical cross-linking using two types of maleated polypropylene, MPA (Mw=9,000) and PMAP (Mw=220,000) were also performed. (author)

  1. Enzymatic saccharification and structural properties of industrial wood sawdust: Recycled ionic liquids pretreatments

    International Nuclear Information System (INIS)

    Auxenfans, Thomas; Buchoux, Sébastien; Larcher, Dominique; Husson, Gérard; Husson, Eric; Sarazin, Catherine

    2014-01-01

    Highlights: • 1-Ethyl-3-metylimidazolium acetate is an effective catalyst for pretreatment of hardwood and softwood sawdust. • Regeneration of cellulosic fraction from ionic liquid is discussed. • 1-Ethyl-3-methylimidazolium acetate can be reused at least 7 times without loss of its efficiency. • Removal of extractives and lignin with slight cellulose and xylan losses were observed. • Better cellulase accessibility to cellulose thanks to the expansion of the powder and the creation of a large porous volume. - Abstract: Wood residues constitute a promising challenge for biochemical processing into bioethanol and chemicals with competitive costs. Here, we report the impacts of pretreatments in a hydrophilic ionic liquid ([C2mim][OAc]), onto the physicochemical properties and enzymatic saccharification of softwood (spruce) and hardwood (oak) sawdust. Enzymatic saccharification of IL- pretreated sawdust is significantly increased (up to 7 times) when compared to untreated ones. Methanol, ethanol or water can be used as polar anti-solvent for the recovery of a cellulose rich fraction after dissolution in IL (i.e regeneration step) without any effect on enzymatic saccharification. Chemical, textural and structural modifications possibly induced by the IL pretreatments have been investigated through various means (Infra-red spectroscopy, NMR, X-ray diffraction) in order to correlate the observed modifications in enzymatic saccharification. This mild pretreatment seemed to mainly act in a breakdown of lignocellulosic organization leading to better cellulase accessibility to cellulose thanks to the expansion of the powder and the creation of a large porous volume (5 times more apparent porous volume). Partial removal of lignin and extractives may also contribute to the best enzymatic performances. The recyclability and reuse up to 7 times of [C2mim][OAc] is shown without the need of strictly anhydrous conditions and any alteration of the pretreatment

  2. Electrical and galvanomagnetic properties of biocarbon preforms of white pine wood

    Science.gov (United States)

    Popov, V. V.; Orlova, T. S.; Ramirez-Rico, J.

    2009-11-01

    The electrical and galvanomagnetic properties of high-porosity biocarbon preforms prepared from white pine wood by pyrolysis at carbonization temperatures T carb = 1000 and 2400°C have been studied. Measurements have been made of the behavior with temperature of the electrical resistivity, as well as of magnetoresistance and the Hall coefficient in the 1.8-300-K temperature interval and magnetic fields of up to 28 kOe. It has been shown that samples of both types (with T carb = 1000 and 2400°C) are characterized by high carrier (hole) concentrations of 6.3 × 1020 and 3.6 × 1020 cm-3, respectively. While these figures approach the metallic concentration, the electrical resistivity of the biocarbon materials studied, unlike that of normal metals, grows with decreasing temperature. Increasing T carb brings about a decrease in electrical resistivity by a factor 1.5-2 within the 1.8-300-K temperature range. The magnetoresistance also follows a qualitatively different pattern at low (1.8-4.2 K) temperatures: it is negative for T carb = 2400°C and positive for T carb = 1000°C. An analysis of experimental data has revealed that the specific features in the conductivity and magnetoresistance of these samples are described by quantum corrections associated inherently with structural characteristics of the biocarbon samples studied, more specifically with the difference between the fractions of the quasi-amorphous and nanocrystalline phases, as well as with the fine structure of the latter phase forming at the two different T carb.

  3. Investigation Of The Color Changing Properties Of Wood Stain Derived From Pinar Leaves

    Directory of Open Access Journals (Sweden)

    Abdi Atılgan

    2011-11-01

    Full Text Available This study was designed to develop an environmentally friendly wood stain derived pinar (Quercus aucheri leaves and determine the color stability of this stain when exposed to UV light irradiation. Wood stains derived from pinar leaves were prepared from aqueous solution with %3 iron (FeSO4.7H2O , % 5 alum ((KAl(SO42.12H2O, and % 10 vinegar mordant mixtures. Scots pine (Pinus sylvestris L., Turkish oriental beech (Fagus orientalis Lipsky and oak (Quercus petraea L. wood specimens were used as staining substrates. After treatment with the stain, the wood panels were exposed to UV light irradiation for periods of 100, 200, and 300 hours and determinated the total color changes was according to ISO 2470 standards. Results showed that wood stain derived from pinar extract provided some color stability after UV irradiation. According to results, Scots pine specimens treated with the pinar extract + iron mixture provided the smallest total color changes. Meanwhile the highest total color change provided on the Scots pine treated with pinar extract+alum mixture.

  4. Effects of Boron Compounds on the Mechanical and Fire Properties of Wood-chitosan and High-density Polyethylene Composites

    Directory of Open Access Journals (Sweden)

    Guo-Fu Wu

    2014-05-01

    Full Text Available Wood-plastic composites (WPCs represent a growing class of durable, low-maintenance construction materials whose use can decrease dependence on petroleum. High-density polyethylene (HDPE, chitosan (CS, wood flour (WF, boric acid (BA, and borax (BX, as well as maleic anhydride grafted polyethylene (MAPE and polyethylene wax (PE wax, were used to develop a durable wood-plastic composite (WPC using the extrusion method. The effects of boron compounds (3%, 6%, 9%, or 12% by weight BA/BX on the mechanical and fire properties of the WPCs were investigated. Mechanical testing indicated that as the percentage weight of boron compounds increased, the flexural modulus, flexural strength, and tensile strength significantly decreased. Cone calorimeter tests were used to characterize the fire performance of the WPCs, and these results suggested that adding BA/BX compounds to WPCs modestly improved the fire performance. As the percentage weight of BA/BX increased from 3% to 9%, the time to ignition (TTI, heat release rate (HRR, total heat release rate (HRR-Total, smoke production rate (SPR, and specific extinction area (SEA of the WPCs were all reduced.

  5. Measuring wood specific gravity, correctly

    Science.gov (United States)

    G. Bruce Williamson; Michael C. Wiemann

    2010-01-01

    The specific gravity (SG) of wood is a measure of the amount of structural material a tree species allocates to support and strength. In recent years, wood specific gravity, traditionally a forester’s variable, has become the domain of ecologists exploring the universality of plant functional traits and conservationists estimating global carbon stocks. While these...

  6. Selected mechanical and physical properties of Chinese tallow tree juvenile wood

    Science.gov (United States)

    Todd F. Shupe; LEslie H. Groom; Thomas L. Eberhardt; Thomas C. Pesacreta; Timothy G. Rials

    2008-01-01

    Chinese tallow tree is a noxious, invasive plant in the Southeastern United States. It is generally considered a nuisance and has no current commercial use. The objective of this research was to determine the moduli of rupture (MOR) and elasticity (MOE) of the stem wood of this species at different vertical sampling locations. Three Chinese tallow trees were felled and...

  7. Guying to prevent wind sway influences loblolly pine growth and wood properties

    Science.gov (United States)

    James D. Burton; Diana M. Smith

    1972-01-01

    Restraining young loblolly pine (Pinus taeda L.) trees from normal swaying in the wind markedly reduced radial growth in the immobilized portion of the bole and accelerated it in the upper, free-swaying portion. Guying also reduced specific gravity, number of earlywood and latewood tracheids, latewood tracheid diameter, and amount of compression wood...

  8. Comparison of anatomical properties of non-coppiced and coppiced wood in six Eucalyptus genotypes

    CSIR Research Space (South Africa)

    Zbonak, A

    2006-01-01

    Full Text Available beneath the bark are known as “coppice”. These grow using the same root system that had been developed for planted trees. Fibre and vessel characteristics in wood are important features since they strongly affect the quality and performance of the final...

  9. Effect of Boron and Phosphate compounds on Thermal and Fire Properties of wood/HDPE composites

    Science.gov (United States)

    Turgay Akbulut; Nadir Ayrilmis; Turker Dundar; Ali Durmus; Robert H. White; Murat Teker

    2011-01-01

    Melting and non-isothermal crystallization behaviors, oxidative induction time, and fire performance of the injection-molded wood flour-high density polyethylene (HDPE) composites (WPCs) incorporated with different levels (4, 8, or 12 wt %) of boron compounds [borax/boric acid (BX/BA) (0.5:0.5 wt %), zinc borate (ZB)] and phosphorus compounds [mono- and di-ammonium...

  10. Effects of Treated Wood Flour on Physico-Mechanical Properties of ...

    African Journals Online (AJOL)

    Wood flour was crushed in to particle size and given two surface treatments each with alkali and 3-chloro-2 hydroxylpropyltrimethylammoniumchloride. The raw, alkali-treated and bonding agent treated fibers were used as natural rubber composites. The samples were used to produce fiber-reinforced natural rubber ...

  11. From Windfall Sharing to Property Ownership: Prosocial Personality Traits in Giving and Taking Dictator Games

    Directory of Open Access Journals (Sweden)

    Kun Zhao

    2018-05-01

    Full Text Available The dictator game is a well-known task measuring prosocial preferences, in which one person divides a fixed amount of windfall money with a recipient. A key factor in real-world transfers of wealth is the concept of property ownership and consequently the related acts of giving and taking. Using a variation of the traditional dictator game (N = 256, we examined whether individual differences under different game frames corresponded with prosocial personality traits from the Big Five (politeness, compassion and HEXACO (Honesty-Humility, Emotionality, eXtraversion, Agreeableness, Conscientiousness, Openness to Experience (honesty-humility, agreeableness models. In the Big Five model, the effects of prosocial personality traits were generally stronger and more consistent for taking than for giving, in line with a “do-no-harm” explanation, whereby prosocial individuals felt less entitled to and less willing to infringe on the endowments of others. In contrast, HEXACO honesty-humility predicted allocations across both frames, consistent with its broad association with fair-mindedness, and providing further evidence of its role in allocations of wealth more generally. These findings highlight the utility of integrating personality psychology with behavioral economics, in which the discriminant validity across prosocial traits can shed light on the distinct motivations underpinning social decisions.

  12. Physico-mechanical properties of Spanish juniper wood considering the effect of heartwood formation and the presence of defects and imperfections

    Directory of Open Access Journals (Sweden)

    Javier de la Fuente-Leon

    2014-04-01

    Full Text Available Aim of study: Determining the main physical and mechanical properties of Spanish juniper wood from Soria (Spain considering the effects of heartwood formation and the presence of defects and imperfections; and comparing the resulting characteristics with similar existing data for other regional softwood species of commercial interest. Area of study: Berlanga de Duero (Soria, Castilla y León, Spain.Material and Methods: Wood physico-mechanical performance was determined by Spanish UNE standards in order to provide proper comparisons to other regional softwood species. An individual tree representing average plot characteristics was selected in all eight 10 m radius circular plots that were established well-representing the heterogeneity of this woodland. The age of every tree was determined reading the number of growth rings at the base of each sampled tree. Every physico-mechanical property was assessed at least 4 times for every wood sample type (sapwood and heartwood, whether clear or with the presence of defects of each tree. Two-way ANOVA was run to assess significant differences in the results. Post hoc all pairwise comparisons were performed using Tukey's test (p < 0.05.Research highlights: Spanish juniper wood resulted harder than other regional commercial conifers, and showed semi-heavyweight heartwood and lightweight sapwood; whereas shrinkage figures remarked its great dimensional stability. The high presence of knots within heartwood made it even heavier, harder, and more resistant to compression parallel to grain. A commercial use of this rare precious wood may contribute to juniper forests preservation in the frame of forest sustainable management plans. Key words: heartwood effect; Juniperus thurifera L.; physico-mechanical wood properties; wood classification; wood defects.

  13. Study of the effect of gamma radiation on some physical-mechanical properties of wood used in Brazilian cultural and artistic heritage

    International Nuclear Information System (INIS)

    Severiano, Lucio Cesar

    2010-01-01

    Wood is considered a natural composite of extreme complexity, basically composed by cellulose, lignin, hemicellulose (polyosis) and extractives. Its composition favors biological attacks from different species. In this context, several techniques have been studied and applied for disinfecting and decontaminating wood-made works of art and cultural heritage, which have been damaged by fungi, bacteria and insects. Gamma radiation emitted by unstable isotopes, such as 60- cobalt, has also been studied as an alternative to the conventional wood preservatives. So, gamma rays treatment has been shown to be efficient to the removal of infestations by insects and microorganisms in wood-made artifacts, to be fast and not to require quarantine because it does not generate toxic waste. Similar to other techniques, this process does not prevent the irradiated material of re-infestation or recontamination. In this context, the effects of relatively high disinfestation gamma radiation doses (up to 100 kGy) on cedro rosa and imbuia, two typical Brazilian wood species, are accompanied by the changes on the following attributes: apparent density, retracting, parallel compression to fibers, bending in the modulus of elasticity, hardness, shear and thermal stability. Results have shown that gamma radiation, in the studied dose range, does not promote alterations on properties of investigated wood species. In case of a re-infestation, these observations indicate that the wood species can be submitted to repeatedly irradiation processes without causing damage to their structure up to the studied dose range, in despite of radiation effects be always cumulative. (author)

  14. Effects of tree species and wood particle size on the properties of cement-bonded particleboard manufacturing from tree prunings.

    Science.gov (United States)

    Nasser, Ramadan A; Al-Mefarrej, H A; Abdel-Aal, M A; Alshahrani, T S

    2014-09-01

    This study investigated the possibility of using the prunings of six locally grown tree species in Saudi Arabia for cement-bonded particleboard (CBP) production. Panels were made using four different wood particle sizes and a constant wood/cement ratio (1/3 by weight) and target density (1200 kg/m3). The mechanical properties and dimensional stability of the produced panels were determined. The interfacial area and distribution of the wood particles in cement matrix were also investigated by scanning electron microscopy. The results revealed that the panels produced from these pruning materials at a target density of 1200 kg m(-3) meet the strength and dimensional stability requirements of the commercial CBP panels. The mean moduli of rupture and elasticity (MOR and MOE) ranged from 9.68 to 11.78 N mm2 and from 3952 to 5667 N mm2, respectively. The mean percent water absorption for twenty four hours (WA24) ranged from 12.93% to 23.39%. Thickness swelling values ranged from 0.62% to 1.53%. For CBP panels with high mechanical properties and good dimensional stability, mixed-size or coarse particles should be used. Using the tree prunings for CBPs production may help to solve the problem of getting rid of these residues by reducing their negative effects on environment, which are caused by poor disposal of such materials through direct combustion process and appearance of black cloud and then the impact on human health or the random accumulation and its indirect effects on the environment.

  15. The Youth Psychopathic Traits Inventory: Measurement Invariance and Psychometric Properties among Portuguese Youths

    Directory of Open Access Journals (Sweden)

    Pedro Pechorro

    2016-08-01

    Full Text Available The aim of the present study was to examine the psychometric properties of the Youth Psychopathic Traits Inventory (YPI among a mixed-gender sample of 782 Portuguese youth (M = 15.87 years; SD = 1.72, in a school context. Confirmatory factor analysis revealed the expected three-factor first-order structure. Cross-gender measurement invariance and cross-sample measurement invariance using a forensic sample of institutionalized males were also confirmed. The Portuguese version of the YPI demonstrated generally adequate psychometric properties of internal consistency, mean inter-item correlation, convergent validity, discriminant validity, and criterion-related validity of statistically significant associations with conduct disorder symptoms, alcohol abuse, drug use, and unprotected sex. In terms of known-groups validity, males scored higher than females, and males from the school sample scored lower than institutionalized males. The use of the YPI among the Portuguese male and female youth population is psychometrically justified, and it can be a useful measure to identify adolescents with high levels of psychopathic traits.

  16. Effect of Steaming on the Colorimetric Properties of Eucalyptus saligna Wood

    Directory of Open Access Journals (Sweden)

    Reinaldo Calçada Guina Luís

    2018-03-01

    Full Text Available ABSTRACT This study aimed to homogenize the color of Eucalyptus saligna wood by means of steaming and compare the resulting color with that of Cariniana legalis wood, a species of high commercial value. To this end, two steaming curves were tested: 100% relative humidity for 12 (T1 and 24 (T2 hours at 90 °C followed by drying in a pilot-scale conventional kiln. The colorimetric parameters L*, a*, b*, C*, and h were determined according to the CIE L*a*b* color measurement system after drying. Results showed that steaming can be used for color homogenization between heartwood and sapwood. The treatment conducted for 24 hours (T2 presented the best results.

  17. Effects of Treatment Materials on the Physical Properties of Eucalyptus (Eucalyptus camaldulensis Dehn. Wood

    Directory of Open Access Journals (Sweden)

    Selahattin Bardak

    2011-04-01

    Full Text Available This study was designed to determine effects on retention and shrink levels of Eucalyptus (Eucalyptus camaldulensis Dehn. which treated with some commercial preservative types, borates, polyethylene glycol, and water repellents. In this study, four type impregnation chemicals were chosen: 1. Commercial preservative types, [Ammonium sulphate, Vacsol-WR WR and Immersol-WR (WR], 2. Borates chemicals, [Boric acid, Borax, Boric acid+ Borax] 3. Polyethylene glycol such as Polyethylene glycol (PEG-400 4. Water repellents [Styrene, Methylmetacrylate.]. As a result, retention % and shrink levels of Eucalyptus wood was lower treated with commercial preservative types and borates preservatives compare to other treatment chemicals. However, retention % levels of Eucalyptus wood treated with WR chemicals were highly significant levels. According to their leachability period although PEG 400 showed antishrink effectiveness other treatments didnt showed antishrink efficiency.

  18. Anatomical and chemical properties and density of Coffea arabica L. wood

    Directory of Open Access Journals (Sweden)

    Marisa Aparecida Pereira

    2014-09-01

    Full Text Available The state of Minas Gerais is the largest producer of coffee in Brazil and the amount of residue in crops seems adequate to support production of solid wood products of Coffea arabica L., which is currently used for energy purposes or remains in the area. This activity adds insignificant value the coffee products and release CO2, which has harmful effects to the environment. This study was conducted with the aim of characterizing technologically Coffea arabica L. wood to enhance its use in furniture, to characterize its anatomical, chemical and wood basic density. The density showed an average of 0.608g.cm-3. The anatomical analysis showed distinct growth layers, semiporosos vessels with simple perforation plates. The axial parenchyma is apotracheal and diffuse in the aggregate with heterogeneous rays, not laminated and fiber libriformes not septate with bordered pits distinct. The chemical content of extract in hot and cold water were respectively 6.1% and 9.6%. The ash content was found to be 0.68%. Data were comparable to those of mahogany (Swietenia macrophylla and Piptadenia peregrina Benth, (angico-vermelho used for the production of furniture.

  19. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, Thomas; Hansen, Kurt Kielsgaard; Hoffmeyer, Preben

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  20. Chemical modification of wood

    Science.gov (United States)

    Roger M. Rowell

    2007-01-01

    After millions of years of evolution, wood was designed to perform in a wet environment, and nature is programmed to recycle it, in a timely way, back to the basic building blocks of carbon dioxide and water through biological, thermal, aqueous, photochemical, chemical, and mechanical degradation. The properties of wood are, for the most part, a result of the chemistry...

  1. Circadian patterns of xylem sap properties and their covariation with plant hydraulic traits in hybrid aspen.

    Science.gov (United States)

    Meitern, Annika; Õunapuu-Pikas, Eele; Sellin, Arne

    2017-06-01

    Physiological processes taking place in plants are subject to diverse circadian patterns but some of them are poorly documented in natural conditions. The daily dynamics of physico-chemical properties of xylem sap and their covariation with tree hydraulic traits were investigated in hybrid aspen (Populus tremula L.×P. tremuloides Michx) in field conditions in order to clarify which environmental drivers govern the daily variation in these parameters. K + concentration ([K + ]), electrical conductivity (σ sap ), osmolality (Osm) and pH of the xylem sap, as well as branch hydraulic traits, were measured in the field over 24-h cycles. All studied xylem sap properties and hydraulic characteristics including whole-branch (K wb ), leaf blade (K lb ) and petiole hydraulic conductances (K P ) showed clear daily dynamics. Air temperature (T A ) and photosynthetic photon flux density (PPFD), but also water vapour pressure deficit (VPD) and relative humidity (RH), had significant impacts on K wb K lb , K P , [K + ] and σ sap . Osm varied only with light intensity, while K B varied depending on atmospheric evaporative demand expressed as T A , VPD or RH. Xylem sap pH depended inversely on soil water potential (Ψ S ) and during daylight also on VPD. Although soil water content was close to saturation during the study period, Ψ S influenced also [K + ] and σ sap . The present study presents evidence of coupling between circadian patterns of xylem sap properties and plant hydraulic conductance providing adequate water supply to foliage under environmental conditions characterised by diurnal variation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  2. Wood burning

    Energy Technology Data Exchange (ETDEWEB)

    Winkelmann, H

    1955-01-01

    Discussed are the use of wood as a fuel, the technique of wood combustion and the operation of wood-burning stoves for cooking and heating. In addition, there is a section which reviews the use of wood stoves in various countries and lists manufacturers of stoves, central heating furnaces and in some cases sawdust burners.

  3. Psychomertic Properties Spielberger\\'s State-Trait Anger Expression Inventory-2 Among of Iranian Students

    Directory of Open Access Journals (Sweden)

    Mohammad Khodayari-Fard

    2010-04-01

    Full Text Available Objective: Since Spielberger's State–Trait Anger Expression Inventory–2 (STAXI–2 has enormous potential for research and therapy, the current study aimed to investigate psychometric properties and normalization of STAXI–2 among Iranian college students. Materials & Methods: Descriptive–survey research method, developing an instrument one, was used. 1140 students (Mean age=21.92, SD=2.89 were drawn from Tehran University via cluster sampling method. 554 (48.6% and 586 (51.4% participants were females and males respectively. Among participants 1080 were singles. The participants were asked to complete two instruments. One of these instruments STAXI–2 and other was one of Multi–dimensional Anger Inventory, Over controlled Hostility Scale, Oxford Happiness inventory, Emotional and NEO– Five Factor Inventory. Results: There were not observed significant differences between females and males participants in most sub–scales of STAXI–2. Also data analysis demonstrated that STAXI–2 and its subscales had significant relationship with parallel instruments. Moreover, the results showed significant mean differences between two groups including high and low emotion intelligence groups and all subscales of STAXI–2. Factor analysis also extracted as many as factors in any part of STAXI–2 in comparison with original version. Based on T scores, separate norms tables were reported. Conclusion: STAXI–2 has an appropriate validity and reliability to measure anger in Iranian young population. Therefore, STAXI–2 as a state and trait assessment device can be used in clinical sets and research

  4. Transferability of microsatellite markers located in candidate genes for wood properties between Eucalyptus species

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    Cintia V. Acuña

    2014-12-01

    Full Text Available Aim of study:  To analyze the feasibility of extrapolating conclusions on wood quality genetic control between different Eucalyptus species, particularly from species with better genomic information, to those less characterized. For this purpose, the first step is to analyze the conservation and cross-transferability of microsatellites markers (SSRs located in candidate genes.Area of study: Eucalyptus species implanted in Argentina coming from different Australian origins.Materials and methods: Twelve validated and polymorphic SSRs in candidate genes (SSR-CGs for wood quality in E. globulus were selected for cross species amplification in six species: E. grandis, E. saligna, E. dunnii, E. viminalis, E. camaldulensis and E. tereticornis.Main results: High cross-species transferability (92% to 100% was found for the 12 polymorphic SSRs detected in E. globulus. These markers revealed allelic diversity in nine important candidate genes: cinnamoyl CoA reductase (CCR, cellulose synthase 3 (CesA3, the transcription factor LIM1, homocysteine S-methyltransferase (HMT, shikimate kinase (SK, xyloglucan endotransglycosylase 2 (XTH2, glutathione S-transferase (GST, glutamate decarboxylase (GAD and peroxidase (PER.Research highlights: The markers described are potentially suitable for comparative QTL mapping, molecular marker assisted breeding (MAB and for population genetic studies across different species within the subgenus Symphyomyrtus.Keywords: validation; cross-transferability; SSR; functional markers; eucalypts; Symphyomyrtus.

  5. Investigating the molecular underpinnings underlying morphology and changes in carbon partitioning during tension wood formation in Eucalyptus.

    Science.gov (United States)

    Mizrachi, Eshchar; Maloney, Victoria J; Silberbauer, Janine; Hefer, Charles A; Berger, Dave K; Mansfield, Shawn D; Myburg, Alexander A

    2015-06-01

    Tension wood has distinct physical and chemical properties, including altered fibre properties, cell wall composition and ultrastructure. It serves as a good system for investigating the genetic regulation of secondary cell wall biosynthesis and wood formation. The reference genome sequence for Eucalyptus grandis allows investigation of the global transcriptional reprogramming that accompanies tension wood formation in this global wood fibre crop. We report the first comprehensive analysis of physicochemical wood property changes in tension wood of Eucalyptus measured in a hybrid (E. grandis × Eucalyptus urophylla) clone, as well as genome-wide gene expression changes in xylem tissues 3 wk post-induction using RNA sequencing. We found that Eucalyptus tension wood in field-grown trees is characterized by an increase in cellulose, a reduction in lignin, xylose and mannose, and a marked increase in galactose. Gene expression profiling in tension wood-forming tissue showed corresponding down-regulation of monolignol biosynthetic genes, and differential expression of several carbohydrate active enzymes. We conclude that alterations of cell wall traits induced by tension wood formation in Eucalyptus are a consequence of a combination of down-regulation of lignin biosynthesis and hemicellulose remodelling, rather than the often proposed up-regulation of the cellulose biosynthetic pathway. © 2014 University of Pretoria New Phytologist © 2014 New Phytologist Trust.

  6. Structural and optical properties of wood and wood finishes studied using optical coherence tomography: application to an 18th century Italian violin.

    Science.gov (United States)

    Latour, Gaël; Echard, Jean-Philippe; Soulier, Balthazar; Emond, Isabelle; Vaiedelich, Stéphane; Elias, Mady

    2009-11-20

    Optical coherence tomography (OCT) is especially attractive for the study of cultural heritage artifacts because it is noninvasive and nondestructive. We have developed an original full-field time-domain OCT system dedicated to the investigation of varnished and painted artifacts: an interferometric Mirau objective allows one to perform the scan without moving the works of art. The axial and transverse high resolution (respectively, 1.5 and 1 microm) are well adapted to the detection of the investigated structures (pigment grains, wood fibers, etc.). The illumination spectrum is in the visible range (centered at 630 nm, 150 nm wide) to potentially allow us to perform spectroscopic OCT on pigment particles. The examination of wood samples coated with a traditional finish, demonstrates the ability of the system to detect particles, characterize layers thickness, and image the three-dimensional wood structures below the varnishes. OCT has finally been applied to study in situ the coated wood surface of an 18th century Italian violin and provides important information for its conservation treatment.

  7. EFFECTS OF IMPREGNATION WITH STYRENE AND NANO-ZINC OXIDE ON FIRE-RETARDING, PHYSICAL, AND MECHANICAL PROPERTIES OF POPLAR WOOD

    Directory of Open Access Journals (Sweden)

    Siroos Habibzade

    2016-12-01

    Full Text Available Nanoparticles have been vastly applied in wood polymer composites (WPCs in the recent years to improve some of the drawbacks of solid wood species. In the present study, the effects of ZnO nanoparticles on fire retarding, physical, and mechanical properties of polymerized poplar wood were investigated. Poplar specimens were impregnated with styrene monomer, containing four different contents of nano-zinc oxide (ZnO (0, 0.5, 1 and 1.5%, based on the dry weight of monomer. Results of the scanning electron microscopy (SEM showed homogeneous dispersion of ZnO nanoparticles in the WPC matrix. Nano-zinc oxide improved physical properties such as dimensional stability and water absorption. Moreover, mechanical properties increased in comparison to the control specimens. The impregnation process also significantly improved some of the fire-retarding properties, including the ignition time; however, the flammability nature of styrene aggravated some others, such as carbonized area. It was concluded that, although most of the properties were improved, the final application of WPC should be taken in to consideration before making decision on whether or not to impregnate populus wood with styrene.

  8. Broad Anatomical Variation within a Narrow Wood Density Range--A Study of Twig Wood across 69 Australian Angiosperms.

    Directory of Open Access Journals (Sweden)

    Kasia Ziemińska

    Full Text Available Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications.Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38-0.62 g cm-3. Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm, vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity.Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P < 0.001. Parenchyma was weakly (0.24 ≤|r|≤ 0.35, P < 0.05 or not associated with vessel properties nor with height, leaf area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P < 0.05. However, vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P < 0.001. Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component.Overall, there seem to be at least three axes of variation in xylem, substantially independent of each other: a wood density spectrum, a fibre-parenchyma spectrum, and a vessel area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.

  9. UV-blocking properties of Zn/ZnO coatings on wood deposited by cold plasma spraying at atmospheric pressure

    Science.gov (United States)

    Wallenhorst, L.; Gurău, L.; Gellerich, A.; Militz, H.; Ohms, G.; Viöl, W.

    2018-03-01

    In this study, artificial ageing of beech wood coated with Zn/ZnO particles by means of a cold plasma spraying process as well as coating systems including a Zn/ZnO layer and additional conventional sealings were examined. As ascertained by colour measurements, the particle coatings significantly decreased UV light-induced discolouration. Even though no significant colour changes were observed for particle-coated and alkyd-sealed samples, ATR-FTIR measurements revealed photocatalytic degradation of the alkyd matrix. In contrast, the polyurethane sealing appeared to be stabilised by the Zn/ZnO coating. Furthermore, morphologic properties of the pure particle coatings were studied by SEM and roughness measurements. SEM measurements confirmed a melting and solidifying process during deposition.

  10. Sound Transmission Properties of Mineral-filled High-Density Polyethylene (HDPE and Wood-HDPE Composites

    Directory of Open Access Journals (Sweden)

    Birm-June Kim

    2014-11-01

    Full Text Available Wood plastic composites (WPCs offer various advantages and potential as a competitive alternative to conventional noise barriers. For this purpose, the influence of composite formulation on the sound transmission loss (TL of WPCs needs to be fully understood. In TL testing, stiffness and surface density are major factors influencing the sound insulation property of filled plastics and WPCs. Experimental TL values decreased as sound frequency increased; and the TL values increased after passing a certain frequency level. The comparison of experimental TL curves among filled composites showed that the addition of fillers led to an increase in resonance frequency and TL values. However, at high filling levels, the stiffness decrease led to TL reductions. The experimental TL curves of filled composites, composed of mass law and stiffness law predictions, were well approximated with their combined TL predictions.

  11. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water......A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... rapidly and showed changes in thickness with fluctuations in relative humidity. Porosity was higher in composites containing mechanically refined (MDF) fibers than in composites containing bleached chemi-thermomechanically refined (CTMP) fibers. Tensile test results suggessted that fiber wetting...

  12. A new physical method to assess handle properties of fabrics made from wood-based fibers

    Science.gov (United States)

    Abu-Rous, M.; Liftinger, E.; Innerlohinger, J.; Malengier, B.; Vasile, S.

    2017-10-01

    In this work, the handfeel of fabrics made of wood-based fibers such as viscose, modal and Lyocell was investigated in relation to cotton fabrics applying the Tissue Softness Analyzer (TSA) method in comparison to other classical methods. Two different construction groups of textile were investigated. The validity of TSA in assessing textile softness of these constructions was tested. TSA results were compared to human hand evaluation as well as to classical physical measurements like drape coefficient, ring pull-through and Handle-o-meter, as well as a newer device, the Fabric Touch Tester (FTT). Physical methods as well as human hand assessments mostly agreed on the softest and smoothest range, but showed different rankings in the harder/rougher side fabrics. TSA ranking of softness and smoothness corresponded to the rankings by other physical methods as well as with human hand feel for the basic textile constructions.

  13. Physico-mechanical, thermal and morphological properties of furfuryl alcohol/2-ethylhexyl methacrylate/halloysite nanoclay wood polymer nanocomposites (WPNCs

    Directory of Open Access Journals (Sweden)

    Md. Rezaur Rahman

    2017-07-01

    Full Text Available In this study, the physical, morphological, mechanical and thermal properties of furfuryl alcohol/2-ethylhexyl methacrylate/halloysite nanoclay wood polymer nanocomposites (FA-co-EHMA-HNC WPNCs were investigated. FA-co-EHMA-HNC WPNCs were prepared via an impregnation method and the properties of the nanocomposites were characterized through the weight percent gain, Fourier transform infrared (FT-IR spectroscopy, scanning electron microscopy (SEM, three-point flexural test, dynamic mechanical thermal analysis (DMTA, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC analysis and moisture absorption test. The weight percent gain in the 50:50 FA-co-EHMA-HNC WPNC was the highest compared with the raw wood (RW and other WPNCs. The FT-IR results confirmed that polymerization took place in the nanocomposites, especially 50:50 FA-co-EHMA-HNC WPNC, which had a reduced amount of hydroxyl groups. The SEM results revealed that the 50:50 FA-co-EHMA-HNC WPNC had the smoothest and most uniform surface among all of the nanocomposites. The 50:50 FA-co-EHMA-HNC WPNC showed the highest flexural strength and modulus of elasticity. The results revealed that the storage modulus and loss modulus of the FA-co-EHMA-HNC WPNCs were higher and the tan δ of FA-co-EHMA-HNC WNPCs was lower compared with the RW. The FA-co-EHMA-HNC WPNCs exhibited the higher thermal stability in the TGA and DSC analysis. The 50:50 FA-co-EHMA-HNC WPNC exhibited remarkably lower moisture absorption compared with the RW. Overall, this study proved that the ratio 50:50 FA-co-EHMA ratio was the most suitable for introduction in the in the RW.

  14. Properties of biochar derived from wood and high-nutrient biomasses with the aim of agronomic and environmental benefits.

    Directory of Open Access Journals (Sweden)

    Rimena R Domingues

    Full Text Available Biochar production and use are part of the modern agenda to recycle wastes, and to retain nutrients, pollutants, and heavy metals in the soil and to offset some greenhouse gas emissions. Biochars from wood (eucalyptus sawdust, pine bark, sugarcane bagasse, and substances rich in nutrients (coffee husk, chicken manure produced at 350, 450 and 750°C were characterized to identify agronomic and environmental benefits, which may enhance soil quality. Biochars derived from wood and sugarcane have greater potential for improving C storage in tropical soils due to a higher aromatic character, high C concentration, low H/C ratio, and FTIR spectra features as compared to nutrient-rich biochars. The high ash content associated with alkaline chemical species such as KHCO3 and CaCO3, verified by XRD analysis, made chicken manure and coffee husk biochars potential liming agents for remediating acidic soils. High Ca and K contents in chicken manure and coffee husk biomass can significantly replace conventional sources of K (mostly imported in Brazil and Ca, suggesting a high agronomic value for these biochars. High-ash biochars, such as chicken manure and coffee husk, produced at low-temperatures (350 and 450°C exhibited high CEC values, which can be considered as a potential applicable material to increase nutrient retention in soil. Therefore, the agronomic value of the biochars in this study is predominantly regulated by the nutrient richness of the biomass, but an increase in pyrolysis temperature to 750°C can strongly decrease the adsorptive capacities of chicken manure and coffee husk biochars. A diagram of the agronomic potential and environmental benefits is presented, along with some guidelines to relate biochar properties with potential agronomic and environmental uses. Based on biochar properties, research needs are identified and directions for future trials are delineated.

  15. Using a quasi-heat-pulse method to determine heat and moisture transfer properties for porous orthotropic wood products or cellular solid materials

    Science.gov (United States)

    M. A. Dietenberger

    2006-01-01

    Understanding heat and moisture transfer in a wood specimen as used in the K-tester has led to an unconventional numerical solution arid intriguing protocol to deriving the transfer properties. Laplace transform solutions of Luikov’s differential equations are derived for one-dimensional heat and moisture transfer in porous hygroscopic orthotropic materials and for a...

  16. Evaluation of seed chemical quality traits and sensory properties of natto soybean.

    Science.gov (United States)

    Yoshikawa, Yoko; Chen, Pengyin; Zhang, Bo; Scaboo, Andrew; Orazaly, Moldir

    2014-06-15

    Natto is a popular soyfood in Japan, and the U.S. is the largest supplier of natto soybeans. However, information on natto seed chemical and sensory properties is very limited. The objectives of this study were to evaluate differences of seed chemical and sensory properties among natto types and determine heritability and correlation. A total of 15 small-seeded natto genotypes (three superior, nine moderate and three inferior) were evaluated for protein, oil, calcium, manganese, boron and sugar content and processed into a natto product to evaluate appearance, stickiness, flavor, texture and shelf-life. The superior natto group had a higher sugar content but lower protein plus oil, calcium, manganese and boron content than other two groups. Most seed quality traits exhibited high heritability. The natto sensory preference was positively correlated with sucrose and oil content, but negatively correlated with seed hardness, protein, protein plus oil, calcium, manganese, and boron contents. Selecting soybean lines with low protein, protein plus oil, calcium, manganese, and boron content while with high sucrose will be an effective approach for soybean breeding for natto production. Published by Elsevier Ltd.

  17. Leaf optical properties shed light on foliar trait variability at individual to global scales

    Science.gov (United States)

    Shiklomanov, A. N.; Serbin, S.; Dietze, M.

    2017-12-01

    Recent syntheses of large trait databases have contributed immensely to our understanding of drivers of plant function at the global scale. However, the global trade-offs revealed by such syntheses, such as the trade-off between leaf productivity and resilience (i.e. "leaf economics spectrum"), are often absent at smaller scales and fail to correlate with actual functional limitations. An improved understanding of how traits vary among communities, species, and individuals is critical to accurate representations of vegetation ecophysiology and ecological dynamics in ecosystem models. Spectral data from both field observations and remote sensing platforms present a rich and widely available source of information on plant traits. Here, we apply Bayesian inversion of the PROSPECT leaf radiative transfer model to a large global database of over 60,000 field spectra and plant traits to (1) comprehensively assess the accuracy of leaf trait estimation using PROSPECT spectral inversion; (2) investigate the correlations between optical traits estimable from PROSPECT and other important foliar traits such as nitrogen and lignin concentrations; and (3) identify dominant sources of variability and characterize trade-offs in optical and non-optical foliar traits. Our work provides a key methodological contribution by validating physically-based retrieval of plant traits from remote sensing observations, and provides insights about trait trade-offs related to plant acclimation, adaptation, and community assembly.

  18. Experimental and numerical analysis of semi-destructive device for in situ assessment of wood properties in compression parallel to grain

    Czech Academy of Sciences Publication Activity Database

    Kloiber, Michal; Kunecký, Jiří; Drdácký, Miloš; Tippner, J.; Sebera, V.

    2017-01-01

    Roč. 51, č. 2 (2017), s. 345-356 ISSN 0043-7719 R&D Projects: GA MK(CZ) DG16P02M026; GA MŠk(CZ) LO1219 Keywords : finite element method * experimental and numerical analysis * historical construction * mechanical properties of wood Subject RIV: AL - Art, Architecture, Cultural Heritage OBOR OECD: Paper and wood Impact factor: 1.509, year: 2016 http://link.springer.com/article/10.1007%2Fs00226-016-0881-6

  19. Wood Dust

    Science.gov (United States)

    Learn about wood dust, which can raise the risk of cancers of the paranasal sinuses and nasal cavity. High amounts of wood dust are produced in sawmills, and in the furniture-making, cabinet-making, and carpentry industries.

  20. Wood Smoke

    Science.gov (United States)

    Smoke is made up of a complex mixture of gases and fine, microscopic particles produced when wood and other organic matter burn. The biggest health threat from wood smoke comes from fine particles (also called particulate matter).

  1. Evaluation of mechanical properties and low velocity impact characteristics of balsa wood and urethane foam applied to impact limiter of nuclear spent fuel shipping cask

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Junsung; Shin, Kwangbok [Hanbat Nat' l Univ., Daejeon (Korea, Republic of); Choi, Woosuk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-11-15

    The paper aims to evaluate the low velocity impact responses and mechanical properties of balsa wood and urethane foam core materials and their sandwich panels, which are applied as the impact limiter of a nuclear spent fuel shipping cask. For the urethane foam core, which is isotropic, tensile, compressive, and shear mechanical tests were conducted. For the balsa wood core, which is orthotropic and shows different material properties in different orthogonal directions, nine mechanical properties were determined. The impact test specimens for the core material and their sandwich panel were subjected to low velocity impact loads using an instrumented testing machine at impact energy levels of 1, 3, and 5J. The experimental results showed that both the urethane foam and the balsa wood core except in the growth direction (z-direction) had a similar impact response for the energy absorbing capacity, contact force, and indentation. Furthermore, it was found that the urethane foam core was suitable as an impact limiter material owing to its resistance to fire and low cost, and the balsa wood core could also be strongly considered as an impact limiter material for a lightweight nuclear spent fuel shipping cask.

  2. Genetic dissection of growth, wood basic density and gene expression in interspecific backcrosses of Eucalyptus grandis and E. urophylla

    Science.gov (United States)

    2012-01-01

    Background F1 hybrid clones of Eucalyptus grandis and E. urophylla are widely grown for pulp and paper production in tropical and subtropical regions. Volume growth and wood quality are priority objectives in Eucalyptus tree improvement. The molecular basis of quantitative variation and trait expression in eucalypt hybrids, however, remains largely unknown. The recent availability of a draft genome sequence (http://www.phytozome.net) and genome-wide genotyping platforms, combined with high levels of genetic variation and high linkage disequilibrium in hybrid crosses, greatly facilitate the detection of quantitative trait loci (QTLs) as well as underlying candidate genes for growth and wood property traits. In this study, we used Diversity Arrays Technology markers to assess the genetic architecture of volume growth (diameter at breast height, DBH) and wood basic density in four-year-old progeny of an interspecific backcross pedigree of E. grandis and E. urophylla. In addition, we used Illumina RNA-Seq expression profiling in the E. urophylla backcross family to identify cis- and trans-acting polymorphisms (eQTLs) affecting transcript abundance of genes underlying QTLs for wood basic density. Results A total of five QTLs for DBH and 12 for wood basic density were identified in the two backcross families. Individual QTLs for DBH and wood basic density explained 3.1 to 12.2% of phenotypic variation. Candidate genes underlying QTLs for wood basic density on linkage groups 8 and 9 were found to share trans-acting eQTLs located on linkage groups 4 and 10, which in turn coincided with QTLs for wood basic density suggesting that these QTLs represent segregating components of an underlying transcriptional network. Conclusion This is the first demonstration of the use of next-generation expression profiling to quantify transcript abundance in a segregating tree population and identify candidate genes potentially affecting wood property variation. The QTLs identified in this

  3. The Effects of Land Configuration and Wood-Shavings Mulch on the Properties of a Sandy Loam Soil in Northeast Nigeria. 2. Changes in Physical Properties

    Directory of Open Access Journals (Sweden)

    Chiroma, AM.

    2006-01-01

    Full Text Available Mulching and ridge tillage are proven technologies for improving soil productivity in semi-arid regions. Yet data quantifying the combined influences of these practices are limited. Our objectives were to determine the changes in selected physical properties of a sandy loam after 4-years of annual tillage and wood-shavings mulching. The tillage and wood-shavings treatments consisted of: Flat bed (FB, Open ridge (OR, Tiedridge (TR, FBM, ORM and TRM were same as FB, OR and TR, respectively except that wood-shavings at a rate of 10 t/ha were surface applied ≈ 2 weeks after sowing each year to serve as both a mulch and an organic amendment. At the end of the trial in 2002, bulk density, penetration resistance, total porosity and soil water content from each of 0-0.075, 0.075-0.15 and 0.15-0.30 m depths were determined. Composite samples from the surface (0.075 and 0.075-0.15 m layers from 3 replicates of each treatment were also collected for the determination of wet aggregate stability and from 0-0.15 m and 0.15-0.30 m layers for determination of saturated hydraulic conductivity (Ksat. After 4 years of annual tillage and addition of woodshavings, soil bulk density and penetration resistance were consistently lower and total porosity higher in the FBM, ORM and TRM treatments than in the FB, OR and TR treatments. Penetration resistance in all treatments was strongly related to soil water content. A 'hoe pan' was established below 0.15 m depth beneath the furrows of the ridged treatments. This could be attributed to human traffic during field operations and ponding of water, which occurred in the furrows following heavy rains. Wet aggregate stability estimated as the proportion of aggregates of size > 0.25 mm (macro-aggregates in the 0-0.15 m layer were significantly (P< 0.05 higher under FBM, ORM and TRM than under FB, OR or TR treatments. Ksat was not influenced by either tillage or wood-shavings treatments but were higher for the mulched plots

  4. Femtosecond laser machining for characterization of local mechanical properties of biomaterials: a case study on wood

    Science.gov (United States)

    Jakob, Severin; Pfeifenberger, Manuel J.; Hohenwarter, Anton; Pippan, Reinhard

    2017-12-01

    The standard preparation technique for micro-sized samples is focused ion beam milling, most frequently using Ga+ ions. The main drawbacks are the required processing time and the possibility and risks of ion implantation. In contrast, ultrashort pulsed laser ablation can process any type of material with ideally negligible damage to the surrounding volume and provides 4 to 6 orders of magnitude higher ablation rates than the ion beam technique. In this work, a femtosecond laser was used to prepare wood samples from spruce for mechanical testing at the micrometre level. After optimization of the different laser parameters, tensile and compressive specimens were produced from microtomed radial-tangential and longitudinal-tangential sections. Additionally, laser-processed samples were exposed to an electron beam prior to testing to study possible beam damage. The specimens originating from these different preparation conditions were mechanically tested. Advantages and limitations of the femtosecond laser preparation technique and the deformation and fracture behaviour of the samples are discussed. The results prove that femtosecond laser processing is a fast and precise preparation technique, which enables the fabrication of pristine biological samples with dimensions at the microscale.

  5. Seed selection by earthworms : chemical seed properties matter more than morphological traits

    OpenAIRE

    Clause, J.; Forey, E.; Eisenhauer, N.; Seal, C.E.; Soudey, A.; Colville, L.; Barot, Sébastien

    2017-01-01

    Aims : The passage of seeds through the earthworm gut potentially damages seeds, altering seed and seedling performances depending on seed traits. This work was conducted to study to what extent chemical and morphological seed traits determine the seed attractiveness for earthworms. Methods : We tested seed selection via the ingestion and digestion of 23 grassland plant species spanning a range of 14 morphological and chemical traits by two common earthworm species: the anecic Lumbricus te...

  6. Material variability and repetitive member factors for the allowable properties of engineered wood products

    Science.gov (United States)

    Steve Verrill; David E. Kretschmann

    2009-01-01

    It has been argued that repetitive member allowable property adjustments should be larger for high-variability materials than for low-variability materials. We report analytic calculations and simulations that suggest that the order of such adjustments should be reversed, that is, given the manner in which allowable properties are currently calculated, as the...

  7. Flat-pressed wood plastic composites from sawdust and recycled polyethylene terephthalate (PET): physical and mechanical properties.

    Science.gov (United States)

    Rahman, Khandkar-Siddikur; Islam, Md Nazrul; Rahman, Md Mushfiqur; Hannan, Md Obaidullah; Dungani, Rudi; Khalil, Hps Abdul

    2013-01-01

    This study deals with the fabrication of composite matrix from saw dust (SD) and recycled polyethylene terephthalate (PET) at different ratio (w/w) by flat-pressed method. The wood plastic composites (WPCs) were made with a thickness of 6 mm after mixing the saw dust and PET in a rotary type blender followed by flat press process. Physical i.e., density, moisture content (MC), water absorption (WA) and thickness swelling (TS), and mechanical properties i.e., Modulus of Elasticity (MOE) and Modulus of Rupture (MOR) were assessed as a function of mixing ratios according to the ASTM D-1037 standard. WA and TS were measured after 24 hours of immersion in water at 25, 50 and 75°C temperature. It was found that density decreased 18.3% when SD content increased from 40% to 70% into the matix. WA and TS increased when the PET content decreased in the matrix and the testing water temperature increased. MOE and MOR were reached to maximum for the fabricated composites (2008.34 and 27.08 N/mm(2), respectively) when the SD content were only 40%. The results indicated that the fabrication of WPCs from sawdust and PET would technically feasible; however, the use of additives like coupling agents could further enhance the properties of WPCs.

  8. Properties of board made from wood powder with phenol-formaldehyde-powder resin; Mokufun wo genryo to shita board no seizo to zaishitsu ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S.; Yamada, M. [Shizuoka Univ., Shizuoka (Japan). Faculty of Agriculture

    1998-04-15

    The purpose of this study is to acquire fundamental knowledge about the factors for production and the physical properties of boards when wood powder is used as the main material and powder adhesive is used as the binder in the formation of wood boards under heat and pressure. The effects of temperature for pressing, specific gravity of board, and the ratio of adhesive on bending strength, internal binding force, and size and stability against moisture are investigated. The temperature behavior at the central area of boards under heat and pressure shows similar tendency of stagnation near 140degC which increases thereafter irrespective of the temperature of the hot plate in this experiment. The bending property increases linearly when the resin content is low, and shows the tendency of leveling off gradually when the resin content is larger than 20%. Linear relation with specific gravity if obtained in the 0.6 to 1.0 specific gravity range. Wood powder boards have high internal size stability in the thickness direction than ordinary wood boards. 13 refs., 11 figs.

  9. Prediction of wood mechanical and chemical properties in the presence and absence of blue stain using two near infrared instruments

    Science.gov (United States)

    Brian K. Via; Chi-Leung So; Todd F. Shupe; Lori G. Eckhardt; Michael Stine; Leslie H. Groom

    2005-01-01

    The objective of this research was to (a) determine if blue stain in solid wood influenced calibration equations developed from a nonstained wood population, (b) assess the bias introduced when scanning was performed by the slave instrument without calibration transfer from the master instrument and (c) partition absorbance-based variation by instrument, stain and...

  10. Effect of Intensive Forest Management Practices on Wood Properties and Pulp Yield of Young, Fast Growing Southern Pine

    Science.gov (United States)

    Timothy D. Faust; Alexander Clark; Charles E. Courchene; Barry D. Shiver; Monique L. Belli

    1999-01-01

    The demand for southern pine fiber is increasing. However, the land resources to produce wood fiber are decreasing. The wood industry is now using intensive cultural treatments, such as competition control, fertilization, and short rotations, to increase fiber production. The impact of these intensive environmental treatments on increased growth is positive and...

  11. Dietary traits of the late Early Pleistocene Bison menneri (Bovidae, Mammalia) from its type site Untermassfeld (Central Germany) and the problem of Pleistocene 'wood bison'

    Science.gov (United States)

    van Asperen, Eline N.; Kahlke, Ralf-Dietrich

    2017-12-01

    Over the course of the Early and early Middle Pleistocene, a climatic cooling trend led to the partial opening up of landscapes in the western Palaearctic. This led to a gradual replacement of browsers by grazers, whilst some herbivore species shifted their diet towards including more grass. Wear patterns of herbivore cheek teeth can inform our understanding of the timing and extent of this change and indicate levels of dietary plasticity. One of the indicator species of the faunal turnover is the first large-sized form of bison in the Palaearctic, Bison menneri. The dental mesowear of the palaeopopulation from the species' late Early Pleistocene type site of Untermassfeld in Central Germany and the Late Pleistocene B. priscus from Taubach, both from habitat mosaics of forested habitats and more open landscapes, have a mixed feeder profile similar to that of North American wood bison, which has a distinct preference for open habitats but occasionally consumes a high amount of browse as a fall-back food. In contrast, the grazer mesowear signature of early Middle Pleistocene B. schoetensacki voigtstedtensis from Voigtstedt indicates these animals likely did not regularly feed in the densely forested area around the site. The mesowear of B. schoetensacki from Süssenborn, in a more open environment, is similar to that of extant European bison. Both Pleistocene and extant bison are grazers to mixed feeders with relatively high tolerance of a suboptimal browsing diet. None of these species can be regarded as true 'wood bison'.

  12. Functional relationships between wood structure and vulnerability to xylem cavitation in races of Eucalyptus globulus differing in wood density.

    Science.gov (United States)

    Barotto, Antonio José; Monteoliva, Silvia; Gyenge, Javier; Martinez-Meier, Alejandro; Fernandez, María Elena

    2018-02-01

    Wood density can be considered as a measure of the internal wood structure, and it is usually used as a proxy measure of other mechanical and functional traits. Eucalyptus is one of the most important commercial forestry genera worldwide, but the relationship between wood density and vulnerability to cavitation in this genus has been little studied. The analysis is hampered by, among other things, its anatomical complexity, so it becomes necessary to address more complex techniques and analyses to elucidate the way in which the different anatomical elements are functionally integrated. In this study, vulnerability to cavitation in two races of Eucalyptus globulus Labill. with different wood density was evaluated through Path analysis, a multivariate method that allows evaluation of descriptive models of causal relationship between variables. A model relating anatomical variables with wood properties and functional parameters was proposed and tested. We found significant differences in wood basic density and vulnerability to cavitation between races. The main exogenous variables predicting vulnerability to cavitation were vessel hydraulic diameter and fibre wall fraction. Fibre wall fraction showed a direct impact on wood basic density and the slope of vulnerability curve, and an indirect and negative effect over the pressure imposing 50% of conductivity loss (P50) through them. Hydraulic diameter showed a direct negative effect on P50, but an indirect and positive influence over this variable through wood density on one hand, and through maximum hydraulic conductivity (ks max) and slope on the other. Our results highlight the complexity of the relationship between xylem efficiency and safety in species with solitary vessels such as Eucalyptus spp., with no evident compromise at the intraspecific level. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Salaita, Ghaleb N.; Ma, Frank M.S.; Parker, Trudy C. [Dow Chemical Company, Technical Center, 3200 Kanawha Turnpike, South Charleston, WV 25303 (United States); Hoflund, Gar B. [Department of Chemical Engineering, University of Florida, P.O. Box 116005, Gainesville, FL 32611 (United States)], E-mail: garho@hotmail.com

    2008-04-30

    In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol (PEG) products including PEG PLUS{sup TM}, PEG 8000 solutions and Compound 20M in varying concentrations. All contained the wood preservative chromated copper arsenate (CCA). One sample was treated with a CCA solution only. The treatments were carried out at 20 deg. C and 150 psig for 1/2 h after exposure to vacuum (28 mmHg) for 15 min. Simulated weathering was achieved in an Atlas 65-W Weather-Ometer for 2000 h with both light and dark periods and rain. The temperature ranged from 23 deg. C during the dark cycle to 35 deg. C during the light cycle. With weathering the XPS O/C ratios increase due to oxidation of the surface. Exposure to UV light results in bond breakage and reaction with oxygen in the presence of air to form organic functional groups such as , , C=O and/or O-C-O. These oxidized products can protect the underlying wood from deterioration if they are insoluble in water and remain on the surface as a protective coating. If soluble, rain washes the compounds away and assists in the degradation. Correlated changes are observed in the XPS O/C ratios, the high-resolution XPS C 1s spectra, the SEM micrographs and physical measurements including thickness alteration, weight loss, and discoloration by yellowing or whitening of the weathered wood. The PEG treatments are effective in protecting wood with the 2% PEG PLUS treatment providing the best weathering behavior similar to that of the CCA treatment. The WR and water treatments yield the poorest weathering properties.

  14. Weathering properties of treated southern yellow pine wood examined by X-ray photoelectron spectroscopy, scanning electron microscopy and physical characterization

    International Nuclear Information System (INIS)

    Salaita, Ghaleb N.; Ma, Frank M.S.; Parker, Trudy C.; Hoflund, Gar B.

    2008-01-01

    In this study the weathering behavior of southern yellow pine (SYP) wood samples pretreated in different solutions has been examined using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and various types of physical characterization regarding material loss and discoloration. The treatment solutions include water as a control, a commercially available water repellent (WR) wood treating additive and polyethylene glycol (PEG) products including PEG PLUS TM , PEG 8000 solutions and Compound 20M in varying concentrations. All contained the wood preservative chromated copper arsenate (CCA). One sample was treated with a CCA solution only. The treatments were carried out at 20 deg. C and 150 psig for 1/2 h after exposure to vacuum (28 mmHg) for 15 min. Simulated weathering was achieved in an Atlas 65-W Weather-Ometer for 2000 h with both light and dark periods and rain. The temperature ranged from 23 deg. C during the dark cycle to 35 deg. C during the light cycle. With weathering the XPS O/C ratios increase due to oxidation of the surface. Exposure to UV light results in bond breakage and reaction with oxygen in the presence of air to form organic functional groups such as , , C=O and/or O-C-O. These oxidized products can protect the underlying wood from deterioration if they are insoluble in water and remain on the surface as a protective coating. If soluble, rain washes the compounds away and assists in the degradation. Correlated changes are observed in the XPS O/C ratios, the high-resolution XPS C 1s spectra, the SEM micrographs and physical measurements including thickness alteration, weight loss, and discoloration by yellowing or whitening of the weathered wood. The PEG treatments are effective in protecting wood with the 2% PEG PLUS treatment providing the best weathering behavior similar to that of the CCA treatment. The WR and water treatments yield the poorest weathering properties

  15. Effect of carbon fiber addition on the electromagnetic shielding properties of carbon fiber/polyacrylamide/wood based fiberboards

    Science.gov (United States)

    Dang, Baokang; Chen, Yipeng; Yang, Ning; Chen, Bo; Sun, Qingfeng

    2018-05-01

    Carbon fiber (CF) reinforced polyacrylamide/wood fiber composite boards are fabricated by mechanical grind-assisted hot-pressing, and are used for electromagnetic interference (EMI) shielding. CF with an average diameter of 150 nm is distributed on wood fiber, which is then encased by polyacrylamide. The CF/polyacrylamide/wood fiber (CPW) composite exhibits an optimal EMI shielding effectiveness (SE) of 41.03 dB compared to that of polyacrylamide/wood fiber composite (0.41 dB), which meets the requirements of commercial merchandise. Meanwhile, the CPW composite also shows high mechanical strength. The maximum modulus of rupture (MOR) and modulus of elasticity (MOE) of CPW composites are 39.52 MPa and 5823.15 MPa, respectively. The MOR and MOE of CPW composites increased by 38% and 96%, respectively, compared to that of polyacrylamide/wood fiber composite (28.64 and 2967.35 MPa).

  16. Leaf optical properties shed light on foliar trait variability at individual to global scales

    Science.gov (United States)

    Shiklomanov, A. N.; Serbin, S.; Dietze, M.

    2016-12-01

    Recent syntheses of large trait databases have contributed immensely to our understanding of drivers of plant function at the global scale. However, the global trade-offs revealed by such syntheses, such as the trade-off between leaf productivity and resilience (i.e. "leaf economics spectrum"), are often absent at smaller scales and fail to correlate with actual functional limitations. An improved understanding of how traits vary within communities, species, and individuals is critical to accurate representations of vegetation ecophysiology and ecological dynamics in ecosystem models. Spectral data from both field observations and remote sensing platforms present a potentially rich and widely available source of information on plant traits. In particular, the inversion of physically-based radiative transfer models (RTMs) is an effective and general method for estimating plant traits from spectral measurements. Here, we apply Bayesian inversion of the PROSPECT leaf RTM to a large database of field spectra and plant traits spanning tropical, temperate, and boreal forests, agricultural plots, arid shrublands, and tundra to identify dominant sources of variability and characterize trade-offs in plant functional traits. By leveraging such a large and diverse dataset, we re-calibrate the empirical absorption coefficients underlying the PROSPECT model and expand its scope to include additional leaf biochemical components, namely leaf nitrogen content. Our work provides a key methodological contribution as a physically-based retrieval of leaf nitrogen from remote sensing observations, and provides substantial insights about trait trade-offs related to plant acclimation, adaptation, and community assembly.

  17. Comparison of wood, fibre and vessel properties of drought-tolerant ...

    African Journals Online (AJOL)

    Three drought-tolerant eucalypt genotypes have been investigated for a broad spectrum of properties to provide a basis for comparison on their suitability for various end-uses. The genotypes included were a Eucalyptus grandis × E. camaldulensis hybrid, E. gomphocephala and E. cladocalyx, selected based on previous ...

  18. Tensile and dimensional properties of wood strands made from plantation southern pine lumber

    Science.gov (United States)

    Qinglin Wu; Zhiyong Cai; Jong N. Lee

    2005-01-01

    Working stresses and performance of strand composite lumber largely depend upon the properties of each individual strand. Southern pine strands from plantation lumber grown in southern Louisiana were investigated in this study in order to understand strand behaviors. The effects of hot-pressing and resin application on tensile modulus, strength, and dimensional...

  19. Dynamic dielectric properties of a wood liquefaction system using polyethylene glycol and glycerol

    Science.gov (United States)

    Mengchao Zhou; Thomas L. Eberhardt; Bo Cai; Chung-Yun Hse; Hui Pan

    2017-01-01

    Microwave-assisted liquefaction has shown potential for rapid thermal processing of lignocellulosic biomass. The efficiency of microwave heating depends largely on the dielectric properties of the materials being heated. The objective of this study was to investigate the dynamic interactions between microwave energy and the reaction system during the liquefaction of a...

  20. The effect of alkali treatment of bamboo on the physical and mechanical properties of particleboard made from bamboo - industrial wood particles

    Directory of Open Access Journals (Sweden)

    vahid vaziri

    2018-02-01

    Full Text Available In this study, physical and mechanical properties of single layer particleboard made from bamboo powder (with and without alkali treatment and wood particles were investigated. Bamboo powder (30 mesh particles was treated with 5% hydroxide sodium for 120 minutes. Industrial wood chips from Sanate Choube Shomal Company were used.The variable in this research were the ratio of bamboo powder (with and without alkali treatment to wood chips (at four levels; 0:100, 10:90, 20:80, 30:70. Urea formaldehyde resin used at 10 percent level of dry weight of raw material as well as ammonium chloride was used as a catalyst at 2 percent level of the dry weight of adhesive. Physical and mechanical properties of panels measured according to EN Standard. Mechanical properties of the particleboards made from treated bamboo was superior to the relevant untreated bamboo. Water absorption and thickness swelling after 2 and 24 hours immersion in water decreased with alkali treatment. Mercerization, or treating cellulose fibers in alkaline solution, because of fibrillation, the removal of lignin and hemicellulose enhances the mechanical properties and dimension stability of the particleboard by promoting resin-fiber mechanical interlocking at the interface. Results showed, there was usability of the treated bamboo up to 30 percent for general purpose boards for use in dry conditions.

  1. Refraction and absorption of microwaves in wood

    International Nuclear Information System (INIS)

    Ziherl, Saša; Bajc, Jurij; Čepič, Mojca

    2013-01-01

    A demonstration experiment for physics students showing the dependence of the refractive index and absorption coefficient of wood on the direction of microwaves is presented. Wood and microwaves enable study of anisotropic properties, which are typically found in crystals. Wood is used as the persuasive representative of uniaxial anisotropic materials due to its visible structure and its consequent anisotropic properties. Wood can be cut in a general direction and wooden plates a few centimetres thick with well-defined fibre orientation are easily prepared. Microwaves are used because wood is transparent for microwaves and their centimetre-scale wavelength is comparable to the wood structure. (paper)

  2. Effect of tin oxide nano particles and heat treatment on decay resistance and physical properties of beech wood (Fagus orientalis

    Directory of Open Access Journals (Sweden)

    Maryam Ghorbani

    2014-11-01

    Full Text Available This research was conducted to investigate the effect of Tin oxide nanoparticles and heat treatment on decay resistance and physical properties of beech wood. Biological and physical test samples were prepared according to EN-113 and ASTM-D4446-05 standards respectively. Samples were classified into 4 groups: control, impregnation with Tin oxide nanoparticles, heat treatment and nano-heat treatment. Impregnation with Tin oxide nano at 5000ppm concentration was carried out in the cylinder according to Bethell method. Then, samples were heated at 140, 160 and 185˚C for 2 and 4 hours. According to results, decay resistance improved with increasing time and temperature of heat treatment. Least weight loss showed 46.39% reduction in nano-heat samples treated at 180˚C for 4 hours in comparison with control at highest weight loss. Nano-heat treated samples demonstrated the maximum amount of water absorption without significant difference with control and nanoparticles treated samples. Increase in heat treatment temperature reduced water absorption so that it is revealed 47.8% reduction in heat treated samples at 180°C for 4h after 24h immersion in water. In nano-heat treated samples at 180˚C for 2h was measured least volume swelling. Volume swelling in nano-treated samples decreased 8.7 and 22.76% after 2 and 24 h immersion in comparison with the control samples respectively.

  3. Influence of Carbonization Temperature on Physicochemical Properties of Biochar derived from Slow Pyrolysis of Durian Wood (Durio zibethinus Sawdust

    Directory of Open Access Journals (Sweden)

    Zaira Zaman Chowdhury

    2016-02-01

    Full Text Available The objective of this study was to explore the influence of pyrolysis temperature on the physicochemical properties of biochar synthesized from durian wood (Durio zibethinus sawdust. Surface morphological features, including the porosity and BET surface area of biochars, provide appropriate dimensions for growing clusters of microorganisms with excellent water retention capacity in soil. Oxygen-containing surface functional groups play a vital role in improving soil fertility by increasing its cation and anion exchange capacities with reduced leaching of nutrients from the soil surface. Biochar was produced via slow pyrolysis of woody biomass (WS using a fixed bed reactor under an oxygen-free atmosphere at different pyrolysis temperatures (350, 450, and 550 °C. The biochars obtained were characterized using ultimate and proximate analyses, Brunauer-Emmett-Teller (BET surface area, field-emission scanning electron microscopy (FE-SEM, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. The yield of biochar decreased from 66.46 to 24.56%, whereas the BET surface area increased sharply from 2.567 to 220.989 m2/g, when the pyrolysis temperature was increased from 350 to 550 °C. The results highlighted the effect of pyrolysis temperature on the structure of the biochar, which could be advantageous for agricultural industries.

  4. Physico-mechanical Properties of Electron Beam Irradiated Particle boards Based on Wood flour/ Polyethylene/Cement Kiln Dust Impregnated with Unsaturated Polyester

    International Nuclear Information System (INIS)

    Abdel-Rahman, H.A.; Khattab, M.M.; Ismail, M.R.

    2010-01-01

    Particle boards were fabricated by mixing wood flour (WF), low density polyethylene (LDPE) and cement kiln dust (CKD) under hot pressure; and then impregnated in unsaturated polyester resin. These impregnated particle boards were subjected to various doses of electron beam irradiation up to 50 kGy. The physico-mechanical properties were characterized in terms of flexural strength, impact strength, water absorption, thickness swelling, and the thermal stability. The results showed that the partial replacement of wood flour with cement kiln dust up to 20% by weight improved the values of flexural strength, and impact strength. However, the water absorption percentage and thickness swelling values decreased with increasing the CKD ratio up to 40%. Furthermore, the treatment with electron beam irradiation doses improved the physico-mechanical properties of the impregnated particle boards up to 50 kGy. The improved results were confirmed by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA)

  5. Wood composites

    Science.gov (United States)

    Lars Berglund; Roger M. Rowell

    2005-01-01

    A composite can be defined as two or more elements held together by a matrix. By this definition, what we call “solid wood” is a composite. Solid wood is a three-dimensional composite composed of cellulose, hemicelluloses and lignin (with smaller amounts of inorganics and extractives), held together by a lignin matrix. The advantages of developing wood composites are (...

  6. Evaluation of Pulp and Paper Properties obtained from Maple Juvenile Wood through Organosolv Alcohol Method Catalyzed by Calcium and Magnesium Salts

    Directory of Open Access Journals (Sweden)

    Reza Naghdi

    2015-05-01

    Full Text Available The properties of catalyzed organosolv pulp obtained from maple juvenile wood were studied. The physical properties of fiber (e.g. length, width, and cell membrane thickness and chemical composition of maple juvenile wood (e.g. average cellulose, lignin, extractives, and ash content were determined. The variables were cooking temperature (190 and 200 ºC and time (40, 60, and 80 minutes. Chemical charge ( 280 ml methanol, 70 ml water, and 0.025 mols of Calcium Chloride and Magnesium Nitrate was kept constant. Pulp screen yields (54.9 to 60.91% and Kappa No. (15.5 to 18.4 were measured. Pulp freeness was reduced to 350 ml CSF in PFI mill, and ten 60 g/m2 handsheets were made from the selected pulps. The strength properties of catalyzed organosolv handsheets including tear length (3.83 to 4.25 km, tear index (10.22 to 12.81 mN.m2/g, and burst index (1.74 to 2.15 kPa.m2/g were compared with those of the conventional Kraft handsheets of maple juvenile wood. The least allowed values of the mentioned properties in the Indian (IS and Japanese international standards (JIS reveal that while the tear length value is slightly below that of the standards, the values of tear and burst indices are well beyond the given standards, and the environmentally-friendly catalyzed organosolv pulping process (higher yield and lower Kappa No. compared to Kraft can be recommended to produce paper pulp from maple juvenile wood.

  7. Effect of wood filler treatment and EBAGMA compatibilizer on morphology and mechanical properties of low density polyethylene/olive husk flour composites

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available This paper deals with plastic-wood composites based on low density polyethylene (LDPE and olive husk flour (OHF. The problem of incompatibility between the hydrophilic wood filler and the LDPE hydrophobic matrix was treated by two methods: a chemical modification of the olive husk flour with maleic anhydride to esterify the free hydroxyl groups of the wood components and the use of a compatibilizer agent, i.e. an ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA terpolymer. The changes in the structure, the morphology, and the properties resulting from these treatments were followed by various techniques, especially FTIR spectroscopy, scanning electron microscopy (SEM, tensile measurements and water absorption. The experimental results indicated that both methods, i.e. the chemical treatment of the olive husk flour with maleic anhydride and the inclusion of EBAGMA terpolymer, improved the interactions between the two composite components and promoted better dispersion of the filler in the matrix. Moreover, ultimate tensile properties were also increased. However, the use of EBAGMA terpolymer as compatibilizer produced better enhancement of the properties of LDPE/OHF composites compared to those treated with maleic anhydride.

  8. Wood for sound.

    Science.gov (United States)

    Wegst, Ulrike G K

    2006-10-01

    The unique mechanical and acoustical properties of wood and its aesthetic appeal still make it the material of choice for musical instruments and the interior of concert halls. Worldwide, several hundred wood species are available for making wind, string, or percussion instruments. Over generations, first by trial and error and more recently by scientific approach, the most appropriate species were found for each instrument and application. Using material property charts on which acoustic properties such as the speed of sound, the characteristic impedance, the sound radiation coefficient, and the loss coefficient are plotted against one another for woods. We analyze and explain why spruce is the preferred choice for soundboards, why tropical species are favored for xylophone bars and woodwind instruments, why violinists still prefer pernambuco over other species as a bow material, and why hornbeam and birch are used in piano actions.

  9. The liquid wood heat flow and material properties as a function of temperature

    Science.gov (United States)

    Mazurchevici, Simona; Quadrini, Fabrizio; Nedelcu, Dumitru

    2018-03-01

    There are three types of ‘liquid wood’, Arbofill, Arboblend and Arboform and will replace plastics materials in the near future taking into account the biodegradability and higher properties versus common used plastics materials. In order to get more information about the materials properties of ‘liquid wood’ the granules and samples obtained by injection molding were studied using Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) for Arboform L,V3 Nature-‘liquid wood’ (A-LW) and Arboform L, V3 Nature reinforced with Aramid Fibers (A-LWAF).In case of A-LW granule studied, the DSC analysis presents that at 97 °C appears an endoderm peak which represents the crystallization of the material, at 175 °C the exoderm peak which means the melting point of the material. After the tested granule cooling period of time this one was tested again and the endoderm peak disappears, which means that crystallization of material disappeared. The melting point of the second test decreases slightly at 174.6 °C. Also, the new test shows that at 61.7 °C the glass transition temperature appears and the melting point slightly decreases. In case of A-LW samples the DSC analyses shows that the melting point increased by 2.77 °C compared to the melting point of Arboform granule. The material behavior is more or less the same without the crystallization area.

  10. Adhesive properties of a symbolic bacterium from a wood-boreing marine shipworm

    International Nuclear Information System (INIS)

    Imam, S.H.; Greene, R.V.; Griffin, H.L.

    1990-01-01

    Adhesive properties of cellulolytic, nitrogen-fixing bacterium isolated from a marine shipworm are described. 35 S-labeled cells of the shipworm bacterium bound preferentially Whatman no.1 cellulose filter paper, compared with its binding to other cellulose substrata or substrata lacking cellulose. The ability of the bacteria to bind to Whatman no. 1 filter paper was significantly reduced by glutaraldehyde or heat treatment of cells. Pretreatment of cells with azide, valinomycin, gramicidin-D, bis-hexafluoroacetylacetone (1799), or carbonyl cyanide-p-trifluoromethoxyphenylhydrazone inhibited adhesion activity. Cells pretreated with pronase or trypsin also exhibited reduced binding activity, but chymotrypsin and peptidase had no effect on adhesion activity. Cellodextrins and methyl cellulose 15 inhibited the adhesion of the shipworm bacteria to filter paper, whereas glucose, cellobiose, and soluble carboxymethyl cellulose had no significant effect. The divalent cation chelators EDTA and EGTA [ethylene hlycol-bis(β-aminoethyl ether)-N,N,N'N'-tetraacetic acid] had little or no effect on adhesive properties of shipworm bacteria. Also, preabsorbing the substratum with extracellular endoglucanase isolated from the ship worm bacterium or 1% bovine serum albumin had no apparent effect on bacterial binding. Low concentration (0.01%) of sodium dodecyl sulfate solubilized a fraction from whole cells, which appeared to be involved in cellular binding activity. After removal of sodium dodecyl, sulfate, several proteins in this fraction associated with intact cells. These cells exhibited up to 50% enhanced binding to filter paper in comparison to cells which had not been exposed to the sodium dodecyl sulfate-solubilized fraction

  11. Change in hydraulic properties and leaf traits of a tall rainforest tree species subjected to long-term throughfall exclusion in the perhumid tropics

    Science.gov (United States)

    Schuldt, B.; Leuschner, C.; Horna, V.; Moser, G.; Köhler, M.; Barus, H.

    2010-11-01

    In a throughfall displacement experiment on Sulawesi, Indonesia, three 0.16 ha stands of a premontane perhumid rainforest were exposed to a two-year soil desiccation period that reduced the soil moisture in the upper soil layers beyond the conventional wilting point. About 25 variables, including leaf morphological and chemical traits, stem diameter growth and hydraulic properties of the xylem in the trunk and terminal twigs, were investigated in trees of the tall-growing tree species Castanopsis acuminatissima (Fagaceae) by comparing desiccated roof plots with nearby control plots. We tested the hypotheses that this tall and productive species is particularly sensitive to drought, and the exposed upper sun canopy is more affected than the shade canopy. Hydraulic conductivity in the xylem of terminal twigs normalised to vessel lumen area was reduced by 25%, leaf area-specific conductivity by 10-33% during the desiccation treatment. Surprisingly, the leaves present at the end of the drought treatment were significantly larger, but not smaller in the roof plots, though reduced in number (about 30% less leaves per unit of twig sapwood area), which points to a drought effect on the leaf bud formation while the remaining leaves may have profited from a surplus of water. Mean vessel diameter and axial conductivity in the outermost xylem of the trunk were significantly reduced and wood density increased, while annual stem diameter increment decreased by 26%. In contradiction to our hypotheses, (i) we found no signs of major damage to the C. acuminatissima trees nor to any other drought sensitivity of tall trees, and (ii) the exposed upper canopy was not more drought susceptible than the shade canopy.

  12. Wood preservation

    Science.gov (United States)

    Rebecca E. Ibach

    1999-01-01

    When left untreated in many outdoor applications, wood becomes subject to degradation by a variety of natural causes. Although some trees possess naturally occurring resistance to decay (Ch. 3, Decay Resistance), many are in short supply or are not grown in ready proximity to markets. Because most commonly used wood species, such as Southern Pine, ponderosa pine, and...

  13. Holistic approach to wood protection

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    When untreated wood is exposed to adverse outdoor conditions, nature has a series of chemistries to degrade it to its original building blocks of carbon dioxide and water. Fungi, termites, heat, moisture, ultraviolet (UV) energy, and chemicals take their toll on the performance properties of wood. We tend to study each of these degradation chemistries as individual...

  14. Effects of wood polymers and extractives on the adsorption of wet-end chemicals and the properties of the sheet - MPKY 03

    Energy Technology Data Exchange (ETDEWEB)

    Bobacka, V; Lindholm, J; Nurmi, M; Naesman, J [Aabo Akademi, Turku (Finland). Lab. of Paper Chemistry; Holmbom, B; Konn, J; Sundberg, A; Willfoer, S [Aabo Akademi, Turku (Finland). Lab. of Forest Products Chemistry

    1999-12-31

    The effects of deposition of dissolved and colloidal substances (disco, DCS) together with fixing agents on the wet end chemistry, and the paper quality have been studied. Increased amounts of wood resin in handsheets results in lower strength properties and friction of the sheets. Addition of isolated polysaccharides together with wood resin results in higher strength properties compared, at the same resin content, to sheets without added polysaccharides. Disco substances released from TMP were adsorbed/deposited onto different fillers. It is possible to determine the distribution of aggregated wood resin in handsheets of kraft pulp by confocal laser scanning microscopy. Addition of iron salts to a TMP suspension results in a decrease in the brightness of the fibers. The adsorption of cationic starch and cationic polyacrylamide was studied as well as the flocculation of a peroxide bleached TMP and mixture of TMP and kraft pulp in the presence of retention aids and fixing agents. The fixing agent had a minor effect on the flocculation in peroxide bleached TMP, while cationic starch induced flocculation after a threshold. When added together, cationic starch induced flocculation immediately. The retention of carbohydrates in the mixture was not much influenced by the presence of fixing agents and retention aids, but the extractives were efficiently retained. Colloidal substances adsorb both cationic starch and polyacrylamide. Of the dissolved substances, pectic acids are most efficiently aggregated. (orig.)

  15. Effects of wood polymers and extractives on the adsorption of wet-end chemicals and the properties of the sheet - MPKY 03

    Energy Technology Data Exchange (ETDEWEB)

    Bobacka, V.; Lindholm, J.; Nurmi, M.; Naesman, J. [Aabo Akademi, Turku (Finland). Lab. of Paper Chemistry; Holmbom, B.; Konn, J.; Sundberg, A.; Willfoer, S. [Aabo Akademi, Turku (Finland). Lab. of Forest Products Chemistry

    1998-12-31

    The effects of deposition of dissolved and colloidal substances (disco, DCS) together with fixing agents on the wet end chemistry, and the paper quality have been studied. Increased amounts of wood resin in handsheets results in lower strength properties and friction of the sheets. Addition of isolated polysaccharides together with wood resin results in higher strength properties compared, at the same resin content, to sheets without added polysaccharides. Disco substances released from TMP were adsorbed/deposited onto different fillers. It is possible to determine the distribution of aggregated wood resin in handsheets of kraft pulp by confocal laser scanning microscopy. Addition of iron salts to a TMP suspension results in a decrease in the brightness of the fibers. The adsorption of cationic starch and cationic polyacrylamide was studied as well as the flocculation of a peroxide bleached TMP and mixture of TMP and kraft pulp in the presence of retention aids and fixing agents. The fixing agent had a minor effect on the flocculation in peroxide bleached TMP, while cationic starch induced flocculation after a threshold. When added together, cationic starch induced flocculation immediately. The retention of carbohydrates in the mixture was not much influenced by the presence of fixing agents and retention aids, but the extractives were efficiently retained. Colloidal substances adsorb both cationic starch and polyacrylamide. Of the dissolved substances, pectic acids are most efficiently aggregated. (orig.)

  16. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

    This thesis deals with the combustion of wood in pulverised fuel power plants. In this type of boiler, the slowest step in the wood conversion process is char combustion, which is one of the factors that not only determine the degree of fuel burnout, but also affect the heat release profile...... of different aspects relevant to wood combustion, including wood structure and composition, wood pyrolysis, wood char properties and wood char oxidation. The full scale campaign, which is the subject of Chapter 3, included sampling of wood fuel before and after milling and sampling of gas and particles...... at the top of the combustion chamber. The collected samples and data are used to obtain an evaluation of the mills in operation at the power plant, the particle size distribution of the wood fuel, as well as the char conversion attained in the furnace. In Chapter 4 an experimental investigation...

  17. N-fertilization has different effects on the growth, carbon and nitrogen physiology, and wood properties of slow- and fast-growing Populus species.

    Science.gov (United States)

    Li, Hong; Li, Mengchun; Luo, Jie; Cao, Xu; Qu, Long; Gai, Ying; Jiang, Xiangning; Liu, Tongxian; Bai, Hua; Janz, Dennis; Polle, Andrea; Peng, Changhui; Luo, Zhi-Bin

    2012-10-01

    To investigate how N-fertilization affects the growth, carbon and nitrogen (N) physiology, and wood properties of poplars with contrasting growth characteristics, slow-growing (Populus popularis, Pp) and fast-growing (P. alba×P. glandulosa, Pg) poplar saplings were exposed to different N levels. Above-ground biomass, leaf area, photosynthetic rates (A), instantaneous photosynthetic nitrogen use efficiency (PNUE (i)), chlorophyll and foliar sugar concentrations were higher in Pg than in Pp. Foliar nitrate reductase (NR) activities and root glutamate synthase (GOGAT) activities were higher in Pg than in Pp as were the N amount and NUE of new shoots. Lignin contents and calorific values of Pg wood were less than that of Pp wood. N-fertilization reduced root biomass of Pg more than of Pp, but increased leaf biomass, leaf area, A, and PNUE(i) of Pg more than of Pp. Among 13 genes involved in the transport of ammonium or nitrate or in N assimilation, transcripts showed more pronounced changes to N-fertilization in Pg than in Pp. Increases in NR activities and N contents due to N-fertilization were larger in Pg than in Pp. In both species, N-fertilization resulted in lower calorific values as well as shorter and wider vessel elements/fibres. These results suggest that growth, carbon and N physiology, and wood properties are more sensitive to increasing N availability in fast-growing poplars than in slow-growing ones, which is probably due to prioritized resource allocation to the leaves and accelerated N physiological processes in fast-growing poplars under higher N levels.

  18. Genetic Properties of Some Economic Traits in Isfahan Native Fowl Using Bayesian and REML Methods

    Directory of Open Access Journals (Sweden)

    Salehinasab M

    2015-12-01

    Full Text Available The objective of the present study was to estimate heritability values for some performance and egg quality traits of native fowl in Isfahan breeding center using REML and Bayesian approaches. The records were about 51521 and 975 for performance and egg quality traits, respectively. At the first step, variance components were estimated for body weight at hatch (BW0, body weight at 8 weeks of age (BW8, weight at sexual maturity (WSM, egg yolk weight (YW, egg Haugh unit and eggshell thickness, via REML approach using ASREML software. At the second step, the same traits were analyzed via Bayesian approach using Gibbs3f90 software. In both approaches six different animal models were applied and the best model was determined using likelihood ratio test (LRT and deviance information criterion (DIC for REML and Bayesian approaches, respectively. Heritability estimates for BW0, WSM and ST were the same in both approaches. For BW0, LRT and DIC indexes confirmed that the model consisting maternal genetic, permanent environmental and direct genetic effects was significantly better than other models. For WSM, a model consisting of maternal permanent environmental effect in addition to direct genetic effect was the best. For shell thickness, the basic model consisting direct genetic effect was the best. The results for BW8, YW and Haugh unit, were different between the two approaches. The reason behind this tiny differences was that the convergence could not be achieved for some models in REML approach and thus for these traits the Bayesian approach estimated the variance components more accurately. The results indicated that ignoring maternal effects, overestimates the direct genetic variance and heritability for most of the traits. Also, the Bayesian-based software could take more variance components into account.

  19. Influence of different degrees of acetylation in the physical and mechanical properties of particleboards and wood-cement composites

    Directory of Open Access Journals (Sweden)

    Setsuo Iwakiri

    2014-12-01

    Full Text Available Chemical modified wood particles used to particleboards manufacture may, at the same time, improve the dimensional stability and damage the internal bond. The aim of this research was find the optimal point of acetylation for particleboards. Pinus taeda particles with different degrees of acetylation, 8, 15 and 20% of weight percentage gain (WGP, were used in the production of particleboards with urea-formaldehyde resin and wood-cement composites produced by mechanical and vibratory compaction. It was evaluated the water absorption, thickness swelling and internal bind of the particleboards according to the European standards EN 317 and EN 319. Particleboards produced with 15 WPG showed the lowest water absorption and thickness swelling values. However, the use of chemically modified wood had a negative influence in the internal bind of the boards. This phenomenon can be explain due to the similar behavior between resin and water, that way, the high degree acetylation stops the adhesive and adherent bind. In the case of wood-cement composites, the internal bind improves as the acetylation degrees get higher. Nevertheless the inhibition of acetylated wood particles to the cement hydration got higher when the WPG was higher than 8%.

  20. Trait-based representation of hydrological functional properties of plants in weather and ecosystem models

    Directory of Open Access Journals (Sweden)

    Ashley M. Matheny

    2017-02-01

    Full Text Available Land surface models and dynamic global vegetation models typically represent vegetation through coarse plant functional type groupings based on leaf form, phenology, and bioclimatic limits. Although these groupings were both feasible and functional for early model generations, in light of the pace at which our knowledge of functional ecology, ecosystem demographics, and vegetation-climate feedbacks has advanced and the ever growing demand for enhanced model performance, these groupings have become antiquated and are identified as a key source of model uncertainty. The newest wave of model development is centered on shifting the vegetation paradigm away from plant functional types (PFTs and towards flexible trait-based representations. These models seek to improve errors in ecosystem fluxes that result from information loss due to over-aggregation of dissimilar species into the same functional class. We advocate the importance of the inclusion of plant hydraulic trait representation within the new paradigm through a framework of the whole-plant hydraulic strategy. Plant hydraulic strategy is known to play a critical role in the regulation of stomatal conductance and thus transpiration and latent heat flux. It is typical that coexisting plants employ opposing hydraulic strategies, and therefore have disparate patterns of water acquisition and use. Hydraulic traits are deterministic of drought resilience, response to disturbance, and other demographic processes. The addition of plant hydraulic properties in models may not only improve the simulation of carbon and water fluxes but also vegetation population distributions.

  1. Wood preservation

    Science.gov (United States)

    Kevin Archer; Stan Lebow

    2006-01-01

    Wood preservation can be interpreted to mean protection from fire, chemical degradation, mechanical wear, weathering, as well as biological attack. In this chapter, the term preservation is applied more restrictively to protection from biological hazards.

  2. Study of Radiation Shielding Properties of selected Tropical Wood Species for X-rays in the 50-150 keV Range

    Directory of Open Access Journals (Sweden)

    S. Aggrey-Smith

    2016-03-01

    Full Text Available This paper compares the attenuation coefficients of 20 tropical hard wood species based on their linear and mass attenuation and half value layer (HVL properties for X-rays of energy 50–150 keV using a narrow collimated beam from a Cs-137 source. The narrow collimated beam method made corrections from multiple and small-angle scatterings of photons unnecessary. The attenuation depended on the chemical composition and densities of the wood species. The linear attenuation coefficients of wood species at 50–150 keV were highest for Pterygota macrocarpa (4.53 m−1 and lowest for Antiaris africana (1.24 m−1; the mass attenuation coefficient was highest for Triplochiton scleroxylon (17.62 m2/kg and lowest for Nesogordonia papaverifera (2.27 m2/kg.The HVL was highest for Antiaris africana (0.27 m and lowest for Pterygota macrocarpa (0.149 m. Pterygota macrocarpa of about 0.36 m thickness could serve as a more affordable radiation shielding material against secondary scatter and leakage radiations in place of lead, copper or concrete for low X-ray radiations up to 150 keV.

  3. Surface chemistry and moisture sorption properties of wood coated with multifunctional alkoxysilanes by sol-gel process

    DEFF Research Database (Denmark)

    Tshabalala, M.A.; Kingshott, P.; VanLandingham, M.R.

    2003-01-01

    penetrated the outer surface layers of the wood and condensed with hydroxyls that may not be readily accessible to the high molecular weight HDTMOS. Once attached to such sites, it is reasonable to assume that some of these surface derivatives of MTMOS condensed with other molecules of MTMOS and HDTMOS...

  4. Effect of environmental conditions on the mechanical properties and fungal degradation of polycaprolactone/microcrystalline cellulose/wood flour composites

    Science.gov (United States)

    Ronald Sabo; Liwei Jin; Nicole Stark; Rebecca E. Ibach

    2013-01-01

    Polycaprolactone (PCL) filled with microcrystalline cellulose (MCC), wood flour (WF), or both were characterized before and after exposure to various environmental conditions for 60 days. PCL/WF composites had the greatest tensile strength and modulus compared to neat PCL or PCL composites containing MCC. Electron microscopy indicated better adhesion between WF...

  5. Psychometric properties of the French version of a scale measuring perceived emotional intelligence : the Trait Meta-Mood Scale (TMMS)

    Science.gov (United States)

    Bourdier, Léna; Duclos, Jeanne; Ringuenet, Damien; Berthoz, Sylvie

    2016-01-01

    Objective: The Trait Meta-Mood Scale (TMMS), a 30-item self-assessment questionnaire, has been developed to measure perceived emotional intelligence (EI) level in 3 dimensions: Attention, Clarity and Repair. This study aimed to explore the psychometric properties of the French version of this instrument. Method: The instrument factor structure, normality, internal consistency, stability and concurrent validity were assessed in a sample of 824 young adults (456 female). Besides TMMS, participants completed self-assessment questionnaires for affectivity (Shortened Beck Depression Inventory, State and Trait Anxiety Inventory, Positive and Negative emotion scale), alexithymia (Bermond-Vorst Alexithymia Questionnaire-B) and interpersonal functioning (Empathy Quotient). Discriminant validity was tested in 64 female patients with anorexia nervosa, identified in literature as having difficulties with introspection, expression and emotional regulation. Results: Confirmatory factor analysis results replicate the 3-factor structure. Internal consistency and reliability indices are adequate. Direction and degree of correlation coefficients between TMMS dimensions and other questionnaires support the instrument concurrent validity. TMMS allows to highlight differences in perceived EI levels between men and women (Attention: p < 0.001 ; Clarity: p < 0.05) as well as between patients with anorexia nervosa and control subjects (p < 0.001 for all 3 dimensions). Conclusion: This first validation study shows satisfying psychometric properties for TMMS French version. PMID:27310229

  6. A new genomic resource dedicated to wood formation in Eucalyptus

    Directory of Open Access Journals (Sweden)

    Couloux Arnaud

    2009-03-01

    Full Text Available Abstract Background Renowned for their fast growth, valuable wood properties and wide adaptability, Eucalyptus species are amongst the most planted hardwoods in the world, yet they are still at the early stages of domestication because conventional breeding is slow and costly. Thus, there is huge potential for marker-assisted breeding programs to improve traits such as wood properties. To this end, the sequencing, analysis and annotation of a large collection of expressed sequences tags (ESTs from genes involved in wood formation in Eucalyptus would provide a valuable resource. Results We report here the normalization and sequencing of a cDNA library from developing Eucalyptus secondary xylem, as well as the construction and sequencing of two subtractive libraries (juvenile versus mature wood and vice versa. A total of 9,222 high quality sequences were collected from about 10,000 cDNA clones. The EST assembly generated a set of 3,857 wood-related unigenes including 2,461 contigs (Cg and 1,396 singletons (Sg that we named 'EUCAWOOD'. About 65% of the EUCAWOOD sequences produced matches with poplar, grapevine, Arabidopsis and rice protein sequence databases. BlastX searches of the Uniref100 protein database allowed us to allocate gene ontology (GO and protein family terms to the EUCAWOOD unigenes. This annotation of the EUCAWOOD set revealed key functional categories involved in xylogenesis. For instance, 422 sequences matched various gene families involved in biosynthesis and assembly of primary and secondary cell walls. Interestingly, 141 sequences were annotated as transcription factors, some of them being orthologs of regulators known to be involved in xylogenesis. The EUCAWOOD dataset was also mined for genomic simple sequence repeat markers, yielding a total of 639 putative microsatellites. Finally, a publicly accessible database was created, supporting multiple queries on the EUCAWOOD dataset. Conclusion In this work, we have identified a

  7. The cutting properties and wear of the knives with DLC and W-DLC coatings, deposited by PVD methods, applied for wood and wood-based materials machining

    OpenAIRE

    M. Pancielejko; A. Czyżniewski; A. Gilewicz; V. Zavaleyev; W. Szymański

    2012-01-01

    Purpose: Performance of DLC and W-DLC coated woodworking knives was investigated. The results of testing DLC and W-DLC coating properties as well as the results of life-time tests in the form of wear of HSS and HM knives with these coatings is presents.Design/methodology/approach: DLC coating was deposited by MCVA method, and W-DLC coating was deposited by pulsed RMS. Tests of knives coated with DLC and W-DLC as uncoated ones was made by machining: MDF board, pinewood slats and floorboard - u...

  8. Wood plastic combination

    International Nuclear Information System (INIS)

    Cunanan, S.A.; Bonoan, L.S.; Verceluz, F.P.; Azucena, E.A.

    1976-03-01

    The purpose of this study is to improve the physical and mechaniproperties of local inferior quality wood species by radiation-induced graft polymerization with plastic monomers. The process involves the following: 1) Preparation of sample; 2) Impregnation of sample with the monomers; 3) Irradiation of the impregnated sample with the use of 20,000 curie Co-60 as gamma-source; 4) Drying of irradiated sample to remove the unpolymerized monomer. Experimentation on different wood species were undertaken and the results given. From the results obtained, it can be concluded that the monomers systems MMA, MMA-USP, and styrene-USP are suitable for graft polymerization with the wood species almon, apitong, bagtikan, mayapis, red lauan, and tanguile. This is shown by their maximum conversion value which range from 86% to 96% with the optimum dose range of 1 to 2 Mrads. However, in the application of WPC process, properties that are required in a given wood product must be considered, thus aid in the selection of the monomer system to be used with a particular wood species. Some promising applications of WPC is in the manufacture of picker sticks, shuttles, and bobbins for the textile industry. However, there is a need for a pilot plant scale study so that an economic assessment of the commercial feasibility of this process can be made

  9. Influence of provenance on physical and mechanical properties wood of Pinus tropicalis Morelet in Viñales. Pinar del Río. Cuba

    Directory of Open Access Journals (Sweden)

    Yarelys García García

    2013-12-01

    Full Text Available The overall objective of this paper is to analyze the effect of origin on the physical-mechanical Pinus tropicalis Morelet wood, with a view to providing the information necessary for their rational use properties. Five provenances were selected in the experimental plots at the Experimental Station of Viñales, where 10 trees were randomly selected to analyze the dendrometer following variables: diameter at 1.30 total height, crown diameter and crown height. In turn, at the height of 1.30 m a log of 50 cm in length for the study Densities, Total shrinkage in volume, radial contraction, Longitudinal, tangential and compression is obtained. The results obtained state that the origin is not a variable that has a marked influence on the physical - mechanical properties analyzed. Diameter 1.30 and crown diameter dendrometric variables are best levels of correlation present in relation to the properties of the wood examined. Considering the results obtained provenances La Jagua and Viñales must be very careful during drying and commissioning since they have a higher coefficient of anisotropy.

  10. Selection and application of exterior stains for wood

    Science.gov (United States)

    R. Sam. Williams; William C. Feist

    1999-01-01

    Exterior stains for wood protect the wood surface from sunlight and moisture. Because stains are formulated to penetrate the wood surface, they are not prone to crack or peel as can film-forming finishes, such as paints. This publication describes the properties of stains and wood, methods for applying stains, and the expected service life of stains.

  11. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

  12. Physical, Chemical, and Biological Properties of Soil under Decaying Wood in a Tropical Wet Forest in Puerto Rico

    Science.gov (United States)

    Marcela Zalamea; Grizelle Gonzalez; D. Jean Lodge

    2016-01-01

    Decaying wood is related to nutrient cycling through its role as either a sink or source of nutrients. However, at micro scales, what is the effect of decaying logs on the physical, chemical,and biotic characteristics of the soil underneath? We took samples from a 0 to 5 cm depth under and a 50 cm distance away from decaying logs (Dacryodes excelsa and Swietenia...

  13. Effects of wood vinegar on properties and mechanism of heavy metal competitive adsorption on secondary fermentation based composts.

    Science.gov (United States)

    Liu, Ling; Guo, Xiaoping; Wang, Shuqi; Li, Lei; Zeng, Yang; Liu, Guanhong

    2018-04-15

    In this study, secondary municipal solid waste composts (SC) and wood vinegar treated secondary compost (WV-SC) was prepared to investigate the capability for single-heavy metals and multi-metal systems adsorption. The adsorption sequence of WV-SC for the maximum single metals sorption capacities was Cd (42.7mgg -1 ) > Cu (38.6mgg -1 ) > Zn (34.9mgg -1 ) > Ni (28.7mgg -1 ) and showed higher than that of SC adsorption isotherm. In binary/quaternary-metal systems, Ni adsorption showed a stronger inhibitory effect compared with Zn, Cd and Cu on both SC and WV-SC. According to Freundlich and Langmuir adsorption isotherm models, as well as desorption behaviors and speciation analysis of heavy metals, competitive adsorption behaviors were differed from single-metal adsorption. Especially, the three-dimensional simulation of competitive adsorption indicated that the Ni was easily exchanged and desorbed. The amount of exchangeable heavy metal fraction were in the lowest level for the metal-loaded adsorbents, composting treated by wood vinegar improved the adsorbed metals converted to the residue fraction. This was an essential start in estimating the multiple heavy metal adsorption behaviors of secondary composts, the results proved that wood vinegar was an effective additive to improve the composts quality and decrease the metal toxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The central role of wood biology in understanding the durability of wood-coating interactions

    Science.gov (United States)

    Alex C. Wiedenhoeft

    2007-01-01

    To design effectively for durability, one must actively and honestly assess the material properties and limitations of each of the components in the design system; wood or wood composite, and the coating. Inasmuch as wood coatings are manufactured to specified tolerances from known materials, we have control of that component of the system. Compared to manmade...

  15. Moisture Performance of wood-plastic composites reinforced with extracted and delignified wood flour

    Science.gov (United States)

    Yao Chen; Nicole M. Stark; Mandla A. Tshabalala; Jianmin Gao; Yongming Fan

    2014-01-01

    This study investigated the effect of using extracted and delignified wood flour on water sorption properties of wood–plastic composites. Wood flour (WF) extraction was performed with three solvent systems: toluene/ethanol (TE), acetone/water (AW), and hot water (HW); delignification was conducted using sodium chlorite/acetic acid solution. A 24 full-factorial...

  16. Psychometric properties of the Polish version of the Trait Emotional Intelligence Questionnaire-Short Form

    Directory of Open Access Journals (Sweden)

    Szczygieł Dorota

    2015-09-01

    Full Text Available The study was aimed at validating the Polish version of the Trait Emotional Intelligence Questionnaire-Short Form (TEIQue-SF. Our findings confirm the reliability and validity of the scale. With respect to reliability, internal consistency coefficients of the TEIQue-SF were comparable to those obtained using the original English version. The evidence of the validity of the TEIQue-SF came from the pattern of relations with the other self-report measure of EI, personality measures, as well as affective and social correlates. We demonstrated that the TEIQue-SF score correlated positively with scores on the Emotional Intelligence Questionnaire (INTE (Jaworowska & Matczak, 2001. The TEIQue- SF score correlated negatively with Neuroticism and positively with Extraversion, Openness, Agreeableness, and Conscientiousness. In addition, scores on the TEIQue-SF were related to dispositional affect, i.e., correlated positively with positive affectivity and negatively with negative affectivity. The TEIQue-SF score correlated positively with social competencies as measured with the Social Competencies Questionnaire (Matczak, 2001. We also found that trait EI, as measured with the TEIQue-SF, was positively related to the richness of one’s supportive social network and this relationship remained statistically significant even after controlling for Big Five variance. We also demonstrated that scoring on the TEIQue-SF was positively related to satisfaction with life and negatively related to perceived stress and these relationships remained significant, even after controlling for positive and negative affectivity. Taken together, these findings suggest that the Polish version of the TEIQue-SF is a reliable and valid measure that inherits the network of associations both from the original version of the TEIQue-SF and the full form of the Polish TEIQue (Wytykowska & Petrides, 2007.

  17. Psychometric Properties of the Autism-Spectrum Quotient for Assessing Low and High Levels of Autistic Traits in College Students.

    Science.gov (United States)

    Stevenson, Jennifer L; Hart, Kari R

    2017-06-01

    The current study systematically investigated the effects of scoring and categorization methods on the psychometric properties of the Autism-Spectrum Quotient. Four hundred and three college students completed the Autism-Spectrum Quotient at least once. Total scores on the Autism-Spectrum Quotient had acceptable internal consistency and test-retest reliability using a binary or Likert scoring method, but the results were more varied for the subscales. Overall, Likert scoring yielded higher internal consistency and test-retest reliability than binary scoring. However, agreement in categorization of low and high autistic traits was poor over time (except for a median split on Likert scores). The results support using Likert scoring and administering the Autism-Spectrum Quotient at the same time as the task of interest with neurotypical participants.

  18. Energy wood. Part 2b: Wood pellets and pellet space-heating systems

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2002-01-01

    The paper gives an overview on pellet utilization including all relevant process steps: Potential and properties of saw dust as raw material, pellet production with drying and pelletizing, standardization of wood pellets, storage and handling of pellets, combustion of wood pellets in stoves and boilers and applications for residential heating. In comparison to other wood fuels, wood pellets show several advantages: Low water content and high heating value, high energy density, and homogeneous properties thus enabling stationary combustion conditions. However, quality control is needed to ensure constant properties of the pellets and to avoid the utilization of contaminated raw materials for the pellet production. Typical data of efficiencies and emissions of pellet stoves and boilers are given and a life cycle analysis (LCA) of wood pellets in comparison to log wood and wood chips is described. The LCA shows that wood pellets are advantageous thanks to relatively low emissions. Hence, the utilization of wood pellet is proposed as a complementary technology to the combustion of wood chips and log wood. Finally, typical fuel cost of wood pellets in Switzerland are given and compared with light fuel oil. (author)

  19. Properties of an α Particle in a Bohrium 270 Nucleus under the Generalized Symmetric Woods-Saxon Potential

    Directory of Open Access Journals (Sweden)

    Bekir Can LÜTFÜOĞLU

    2017-04-01

    Full Text Available The energy eigenvalues and the wave functions of an α particle in a Bohrium 270 nucleus have been calculated by solving Schrödinger equation for Generalized Symmetric Woods-Saxon potential. Using the energy spectrum by excluding and including the quasi-bound eigenvalues, entropy, internal energy, Helmholtz energy, and specific heat, as functions of reduced temperature have been calculated. Stability and emission characteristics have been interpreted in terms of the wave and thermodynamic functions. The kinetic energy of a decayed α particle was calculated using the quasi-bound states, which has been found close to the experimental value.

  20. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J

    1978-01-01

    A preliminary study was made of the chemistry of pyrogallol- and catecholtannins, their general properties and methods of extraction and determination. Three methods of estimation - Lowenthal, powdered hide and spectrophotometry - were compared using two control solutions, four samples of wood and one of bark. Using the empirical powdered hide method, tannins of both types were estimated in wood and bark of various tropical species (some separately and some as a mixture), Moroccan oaks (Quercus suber and Q. ilex), and European oak 9Q. petraea). Further tests were made on the wood and bark of the two mangrove species, Rhizophora mangle and R. racemosa, by subjecting them to successive extraction with a range of solvents. None of the woods tested had as much as the 10% of tannins considered necessary in economic sources. The bark of the two mangroves, of Eucalyptus urophylla and of Prosopis africana had tannin contents over 10% and the latter two species had very favorable tannin/non-tannin ratios. All the tropical species, with the probable exception of E. urophylla, had only catecholtannins. Only the oaks and E. urophylla bark gave positive results when tested for gallotannins.

  1. The Effects of CaCO3 Coated Wood Free Paper Usage as Filler on Water Absorption, Mechanical and Thermal Properties of Cellulose-High Density Polyethylene Composites

    Directory of Open Access Journals (Sweden)

    Emrah PEŞMAN

    2016-11-01

    Full Text Available In this study some physical, mechanical and thermal characteristics of high density polyethylene (HDPE and CaCO3 coated/pigmented wood free paper fiber composites were investigated. The fillers used in this study were uncoated cellulose, 5.8 %, 11.5 %, 16.5 % and 23.1 % CaCO3 coated wood free paper fibers. Each filler type was mixed with HDPE at 40% by weight fiber loading. In this case, the ratio of CaCO3 in plastic composites were calculated as 0 %, 2.3 %, 4.6 %, 6.6 % and 9.2 % respectively. Increased CaCO3 ratio improved the moisture resistant, flexural and tensile strength of cellulose-HDPE composites. However, the density of the cellulose-HDPE composites increased with CaCO3 addition. Energy Dispersive Spectroscopy on Scanning Electron Microscope analysis demonstrated the uniform distribution of CaCO3 and cellulose fiber in plastic matrix. In addition, the thermal properties of fiber plastic composites were investigated. The results of Differential scanning calorimetry analysis revealed that the crystallinity of the samples decreased with increasing CaCO3 content. Consequently, this work showed that CaCO3 coated waste paper fibers could be used as reinforcing filler against water absorption in thermoplastic matrix.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.14222

  2. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE Addition

    Directory of Open Access Journals (Sweden)

    Yun Lu

    2013-06-01

    Full Text Available This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs. The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%–8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  3. Enhancement of the Mechanical Properties of Basalt Fiber-Wood-Plastic Composites via Maleic Anhydride Grafted High-Density Polyethylene (MAPE) Addition.

    Science.gov (United States)

    Chen, Jinxiang; Wang, Yong; Gu, Chenglong; Liu, Jianxun; Liu, Yufu; Li, Min; Lu, Yun

    2013-06-18

    This study investigated the mechanisms, using microscopy and strength testing approaches, by which the addition of maleic anhydride grafted high-density polyethylene (MAPE) enhances the mechanical properties of basalt fiber-wood-plastic composites (BF-WPCs). The maximum values of the specific tensile and flexural strengths are achieved at a MAPE content of 5%-8%. The elongation increases rapidly at first and then continues slowly. The nearly complete integration of the wood fiber with the high-density polyethylene upon MAPE addition to WPC is examined, and two models of interfacial behavior are proposed. We examined the physical significance of both interfacial models and their ability to accurately describe the effects of MAPE addition. The mechanism of formation of the Model I interface and the integrated matrix is outlined based on the chemical reactions that may occur between the various components as a result of hydrogen bond formation or based on the principle of compatibility, resulting from similar polarity. The Model I fracture occurred on the outer surface of the interfacial layer, visually demonstrating the compatibilization effect of MAPE addition.

  4. Six potencial woods for bows of stringed instruments: organoleptic properties, machining and commercial availability. Seis madeiras potenciais para arcos de instrumentos de corda: propriedades organolépticas, trababilidade e disponibilidade comercial.

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz LONGUI

    2011-12-01

    Full Text Available In this paper it was investigated the organoleptic properties and machining of six potential woods for bows of stringed instruments and compared the results with those mentioned for the Caesalpinia echinata wood, the reference for modern bows. Thirty wood stores were visited in different cities of the São Paulo state to verify the commercial availability of these woods. We concluded that despite the traditionalism of the red tones in the woods for bows, woods with yellowish tones such as Handroanthus spp. and Dipteryx spp. or brownish such as Diplotropis spp. with appropriate properties, may offer alternative colors and textures to the musicians. It was observed that the Mezilaurus itauba and Astronium lecointei, woods with easy machining, have no potential suitable for bows. Regarding to availability, all woods tested are relatively easy to find nowadays in the wood market. Handroanthus spp. and Dipteryx spp. showed greater potential for making bows for professional musicians.The woods of Mezilaurus itauba and Astronium lecointei did not show good potentialfor bows.Neste trabalho foram investigadas as propriedades organolépticas e a trabalhabilidade de seis madeiras potenciais para arcos de instrumentos de corda e os resultados comparados com os da madeira de Caesalpinia echinata, referência para arcos modernos. Foram visitadas 30 madeireiras em diferentes cidades do Estado de São Paulo para observar a disponibilidade das seis madeiras. Conclui-se que apesar do tradicionalismo dos tons de vermelhos na madeira para arcos, outras madeiras com tons amarelados como Handroanthus spp. e Dipteryx spp. ou acastanhados como Diplotropis spp., desde que possuam propriedades adequadas, podem oferecer alternativas de cores e texturas para os músicos. Madeiras de fácil trabalhabilidade, como Mezilaurus itauba e Astronium lecointei não são adequadas para a fabricação dos arcos. Atualmente, todas as madeiras testadas são relativamente fáceis de

  5. PHYSICAL AND STRENGTH PROPERTIES OF BRICKS PRODUCED FROM PORTLAND CEMENT AND SAW DUST OF DANIELIA OLIVERII WOOD

    Directory of Open Access Journals (Sweden)

    David Oriabure EKHUEMELO

    2016-12-01

    Full Text Available This study investigated the use of sawdust as partial replacement for sand in wood-concrete hollow blocks. Sharp sand, ordinary Portland cement (binder and sawdust were used as raw materials. Sawdust was treated by boiling then sieved after drying using British Standard sieve of 3.35mm to remove sticky wood capable of causing pores. The quantities of sawdust used were 0%, 5%, 10%, 15% and 20%. A mixing proportion of 1:8 cement sand ratio, moulding machine with single 6” (450mm x 225mm x 150mm mould and vibrated with 5.0KW power machine for adequate compaction were used. Wood-concrete block was cured for 28 days. The blocks produced were tested for compressive strength and water absorption. The results showed that mean compressive strength of 100% sand was 2.81N/mm2 followed by 95% sand and 5% sawdust replacement with 1.58N/mm2 ; 90% Sand and 10% sawdust replacement with 0.55N/mm2 ; 85% sand and 15% sawdust replacement with 0.43 N/mm2 and 80% sand 20% sawdust replacement with 0.24N/mm2 . The result further showed that as the percentage of sawdust increased, the compressive strength decreased. At 28 days, the compressive strength of blocks with 5% SD replacement satisfied meets Ghana Building Code for non- load bearing walls. The results also reveals that blocks with 80% sand 20% sawdust replacement level has the highest water absorption (23.72% followed by 85% Sand and 15% sawdust replacement (20.40%; 90% sand and 10% sawdust replacement (18.0%; 95% sand and 5% sawdust replacement (12.12% and 100% sand and 0% sawdust replacement (11.43%. It was concluded that 5% sawdust (8kg replacement and cured 28 days could be used for non-load bearing walls. It was recommended that further research should be carried out to evaluate sawdust replacement level within the range of 1-4% to ascertain results that could be used for various other purposes.

  6. Physical and Strength Properties of Bricks Produced from Portland Cement and Saw Dust of Danielia Oliverii Wood

    Directory of Open Access Journals (Sweden)

    David Oriabure EKHUEMELO

    2016-12-01

    Full Text Available This study investigated the use of sawdust as partial replacement for sand in wood-concrete hollow blocks. Sharp sand, ordinary Portland cement (binder and sawdust were used as raw materials. Sawdust was treated by boiling then sieved after drying using British Standard sieve of 3.35mm to remove sticky wood capable of causing pores. The quantities of sawdust used were 0%, 5%, 10%, 15% and 20%. A mixing proportion of 1:8 cement sand ratio, moulding machine with single 6” (450mm x 225mm x 150mm mould and vibrated with 5.0KW power machine for adequate compaction were used. Wood-concrete block was cured for 28 days. The blocks produced were tested for compressive strength and water absorption. The results showed that mean compressive strength of 100% sand was 2.81N/mm2 followed by 95% sand and 5% sawdust replacement with 1.58N/mm2 ; 90% Sand and 10% sawdust replacement with 0.55N/mm2 ; 85% sand and 15% sawdust replacement with 0.43 N/mm2 and 80% sand 20% sawdust replacement with 0.24N/mm2 . The result further showed that as the percentage of sawdust increased, the compressive strength decreased. At 28 days, the compressive strength of blocks with 5% SD replacement satisfied meets Ghana Building Code for non- load bearing walls. The results also reveals that blocks with 80% sand 20% sawdust replacement level has the highest water absorption (23.72% followed by 85% Sand and 15% sawdust replacement (20.40%; 90% sand and 10% sawdust replacement (18.0%; 95% sand and 5% sawdust replacement (12.12% and 100% sand and 0% sawdust replacement (11.43%. It was concluded that 5% sawdust (8kg replacement and cured 28 days could be used for non-load bearing walls. It was recommended that further research should be carried out to evaluate sawdust replacement level within the range of 1-4% to ascertain results that could be used for various other purposes.

  7. Tree species traits influence soil physical, chemical, and biological properties in high elevation forests.

    Directory of Open Access Journals (Sweden)

    Edward Ayres

    Full Text Available BACKGROUND: Previous studies have shown that plants often have species-specific effects on soil properties. In high elevation forests in the Southern Rocky Mountains, North America, areas that are dominated by a single tree species are often adjacent to areas dominated by another tree species. Here, we assessed soil properties beneath adjacent stands of trembling aspen, lodgepole pine, and Engelmann spruce, which are dominant tree species in this region and are distributed widely in North America. We hypothesized that soil properties would differ among stands dominated by different tree species and expected that aspen stands would have higher soil temperatures due to their open structure, which, combined with higher quality litter, would result in increased soil respiration rates, nitrogen availability, and microbial biomass, and differences in soil faunal community composition. METHODOLOGY/PRINCIPAL FINDINGS: We assessed soil physical, chemical, and biological properties at four sites where stands of aspen, pine, and spruce occurred in close proximity to one-another in the San Juan Mountains, Colorado. Leaf litter quality differed among the tree species, with the highest nitrogen (N concentration and lowest lignin:N in aspen litter. Nitrogen concentration was similar in pine and spruce litter, but lignin:N was highest in pine litter. Soil temperature and moisture were highest in aspen stands, which, in combination with higher litter quality, probably contributed to faster soil respiration rates from stands of aspen. Soil carbon and N content, ammonium concentration, and microbial biomass did not differ among tree species, but nitrate concentration was highest in aspen soil and lowest in spruce soil. In addition, soil fungal, bacterial, and nematode community composition and rotifer, collembolan, and mesostigmatid mite abundance differed among the tree species, while the total abundance of nematodes, tardigrades, oribatid mites, and prostigmatid

  8. Improved Wood Properties Through Genetic Manipulation: Engineering of Syringyl Lignin in Softwood Species Through Xylem-Specific Expression of Hardwood Syringyl Monolignol Pathway Genes

    Energy Technology Data Exchange (ETDEWEB)

    Chandrashekhar P. Joshi; Vincent L. Chiang

    2009-01-29

    Project Objective: Our long-term goal is to genetically engineer higher value raw materials with desirable wood properties to promote energy efficiency, international competitiveness, and environmental responsiveness of the U.S. forest products industry. The immediate goal of this project was to produce the first higher value softwood raw materials engineered with a wide range of syringyl lignin quantities. Summary: The most important wood property affecting directly the levels of energy, chemical and bleaching requirements for kraft pulp production is lignin. Softwoods contain almost exclusively chemically resistant guaiacyl (G) lignin, whereas hardwoods have more reactive or easily degradable lignins of the guaiacyl (G)-syringyl (S) type. It is also well established that the reactive S lignin component is the key factor that permits much lower effective alkali and temperature, shorter pulping time and less bleaching stages for processing hardwoods than for softwoods. Furthermore, our pulping kinetic study explicitly demonstrated that every increase in one unit of the lignin S/G ratio would roughly double the rate of lignin removal. These are clear evidence that softwoods genetically engineered with S lignin are keys to revolutionizing the energy efficiency and enhancing the environmental performance of this industry. Softwoods and hardwoods share the same genetic mechanisms for the biosynthesis of G lignin. However, in hardwoods, three additional genes branch out from the G-lignin pathway and become specifically engaged in regulating S lignin biosynthesis. In this research, we simultaneously transferred aspen S-specific genes into a model softwood, black spruce, to engineer S lignin.

  9. EFFECT OF LAMINATE INCLUSION AND THE TYPE OF ADHESIVE IN THE PROPERTIES OF OSB PANELS OF THE WOOD FROM Pinus oocarpa

    Directory of Open Access Journals (Sweden)

    José Benedito Guimarães júnior

    2012-11-01

    Full Text Available The aim of the study was to evaluate the influence of laminate inclusion and the type of adhesive on the physical and mechanical properties of OSB panels produced from the wood of Pinus oocarpa. The experimental design consisted of four treatments. Laminateinclusion and urea-formaldehyde and phenol-formaldehyde adhesives applied in combination with the panel layer were evaluated. For each treatment, three panels with nominal density of 0.65 g.cm-3, 1% to 6% paraffin and adhesive were produced. In the manufacturing of thepanels, temperature of 180 ° C, pressure of 3.95 MPa and pressing time of 8 minutes were adopted. From the results it is concluded that: the species Pinus oocarpa has great potential for use in the production of OSB panels; the laminate inclusion resulted in significant improvement in the properties of water absorption and thickness swelling after immersion for two hours, as well as in the modulus of elasticity and modulus of rupture in parallel direction; and the panels made with urea-formaldehyde adhesives in the core and phenol-formaldehydeon the faces statistically equal to panels only with the phenol-formaldehyde adhesive in statistically, except in the internal bonding property.

  10. Turning wood residues into wood revenues

    International Nuclear Information System (INIS)

    Graham, R.G.; Kravetz, Don

    1996-01-01

    Ensyn is a profitable commercial company which derives its revenues from the conversion of wood residues into liquid biofuel and chemicals. The technology, Rapid Thermal Processing (RTP (TM) )is based on extremely fast ''cracking'' of biomass which results in light liquid yields exceeding 70% by weight, from wood. Whether producing chemicals or liquid biofuel, the RTP plant is configured identically and operated essentially in the same mode. Chemicals production simply allows economical production to occur at a lower plant capacity, as low as 2 tonnes/day, than is feasible for a dedicated fuel plant (typically greater than 100 tonnes/day). Ensyn has developed the commercialisation of RTP TM from bench to industrial scale in 10 years. A variety of crative funding initiatives in the early years allowed for capital to be raised for R and D without the loss of intellectual property (IP). The transition years of technology demonstration, prior to full commercialisation, were funded by a blend of revenues from venture capital and public sources, and by quickly tapping into a niche market for RTP TM . The utilisation of the technology at the niche market scale opened the doors to the larger fuel and commodity markets. Once, again, both IP and control of the company were maintained during these years. Flexibility, creativity and expertise are necessary to understand the significance of various financing options (private investments, commercial banking and bond issues) and to integrate these options with various renewable energy, recycling and tax incentives. Understanding these options with various renewable energy, recycling and tax incentives is necessary. Understanding both the core and peripheral needs of the customer are essential in successfully advancing a commercial wood energy venture. Ensyn's experience in these areas is the focus of the paper. (Author)

  11. Choosing Wood Burning Appliances

    Science.gov (United States)

    Information to assist consumers in choosing a wood burning appliance, including types of appliances, the differences between certified and non-certified appliances, and alternative wood heating options.

  12. Effect of activation on the porous structure and the strain and strength properties of beech wood biocarbon

    Science.gov (United States)

    Shpeizman, V. V.; Orlova, T. S.; Spitsyn, A. A.; Ponomarev, D. A.; Bogdanovich, N. I.; Martinez-Fernández, J.

    2017-01-01

    The effect of activation on the size, specific volume, and surface area of pores in a monolithic biomorphic material obtained by carbonization of beech wood is studied. It is shown that under optimal activation mode with a steam heated to 970°C, the total pore volume and surface, determined by adsorption curves, increased by 20 and 18 times, respectively. With the use of high-precision interferometric procedure, strain curves are obtained under uniaxial compression with a stepwise loading, and the strain rate is measured with a step of moving of 325 nm for activated and nonactivated samples. Despite an increase in porosity, the strength and maximum deformation of the samples do not decrease. The behavior of the strain rate jumps is analyzed in the micro- and nanometer range. It is shown that the maximum size of the micrometer jumps (4 μm) correlates well with the average size of the possible strain area in the samples (the average distance between the pores of small size), and the minimum dimensions of the strain jumps are close to the size of mesopores. Assessment of the strain change and its rate upon activation indicates that the effect of activation on the strain and strength characteristics is defined by nanometer defects, the most likely of which are microand mesopores.

  13. The effect of temperature and heating rate on char properties obtained from solar pyrolysis of beech wood.

    Science.gov (United States)

    Zeng, Kuo; Minh, Doan Pham; Gauthier, Daniel; Weiss-Hortala, Elsa; Nzihou, Ange; Flamant, Gilles

    2015-04-01

    Char samples were produced from pyrolysis in a lab-scale solar reactor. The pyrolysis of beech wood was carried out at temperatures ranging from 600 to 2000°C, with heating rates from 5 to 450°C/s. CHNS, scanning electron microscopy analysis, X-ray diffractometry, Brunauer-Emmett-Teller adsorption were employed to investigate the effect of temperature and heating rate on char composition and structure. The results indicated that char structure was more and more ordered with temperature increase and heating rate decrease (higher than 50°C/s). The surface area and pore volume firstly increased with temperature and reached maximum at 1200°C then reduced significantly at 2000°C. Besides, they firstly increased with heating rate and then decreased slightly at heating rate of 450°C/s when final temperature was no lower than 1200°C. Char reactivity measured by TGA analysis was found to correlate with the evolution of char surface area and pore volume with temperature and heating rate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Heating and ignition of small wood cylinders

    Science.gov (United States)

    Wallace L. Fons

    1950-01-01

    The literature provides limited information on the time of ignition of wood under conditions of rapid heating such as occur in forest and structure fires. An investigation was made of ease of ignition as affected by such physical properties of wood as initial temperature, size, and moisture content and by temperature of ambient gas or rate of heating. Temperature-time...

  15. Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth

    Directory of Open Access Journals (Sweden)

    Martyna Malgorzata Kotowska

    2015-03-01

    Full Text Available For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing towards the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density. We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia; three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, wood density showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and wood density. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation

  16. Effects of Wood Ash on Soil Fungi

    DEFF Research Database (Denmark)

    Cruz Paredes, Carla

    ), copper (Cu) and nickel (Ni), is a major environmental concern. This work is part of the project ASHBACK (www.ashback.dk) which addresses the potentials and possible problems in re-distributing wood ash to the forest. The aim of this thesis was to determine the effects of biomass ash application...... in a Norway spruce forest where different amounts of wood ash were spread on the soil to study the effects on ectomycorrhizal (ECM) fungi, bioaccumulation of metals in sporocarps, and microbial communities. Laboratory microcosm experiments were run in parallel to the field studies, to compare the effects...... of wood ash with factorial additions of lime and Cd to disentangle the pH and Cd effects of wood ash amendments using community trait distributions. Barley yield, P content, and Cd content were not affected by biomass ashes. Some arbuscular mycorrhizal (AM) fungal species were reduced when biomass ashes...

  17. Effects of wood saw dust ash admixed with treated sisal fibre on the geotechnical properties of lateritic soil

    Directory of Open Access Journals (Sweden)

    John Engbonye SANI

    2017-12-01

    Full Text Available The preliminary investigation conducted on the lateritic soil collected at Shika, Zaria shows that it falls under A-7-6 (10 classification for AASHTO (1986 and CL according to unified soil classification system USCS (ASTM 1992. The soil was treated with both wood saw dust ash (WSDA and treated sisal fiber, in stepped concentration of 0,2,4,6, and 8% for WSDA and 0, 0.25, 0.5, 0.75 and 1% treated sisal fibre by dry weight of soil using Standard proctor. The Sisal Fibre was treated with Sodium Borohydride (NaBH4 (1% wt/vol for 60 minutes at room temperature to remove the cellulose content present in the Fibre. Statistical analysis was carried out on the obtained results using XLSTART 2017 software and analysis of variance with the Microsoft Excel Analysis Tool Pak Software Package. The liquid limit (LL of the soil was found to be 48% while the plastic limit(PL is 21.27%. The maximum dry density(MDDhowever, decreases generally from a value of 1.85 Mg/m3 to 1.68Mg/m3 at 0.25% sisal fiber content/0% WSDA. It has its least value of 1.57Mg/m3 at 1% sisal fiber and 8% WSDA. The OMC increased from 18 % of the natural soil to 23.7% at 0.75% sisal fiber / 6% WSDA content. There was a general increase in the value of UCS of the soil-sisal fibre mixture with WSDA content from 100 kN/m2 of the natural soil to 696 kN/m2 at 0.75 % sisal fibre content / 6% WSDA. The UCS value met the standard of 687-1373 kN/m2 requirements of sub base for adequate lime and cement stabilization, respectively (Ingas and Metcalf 1972.

  18. Theoretical modeling and experimental analyses of laminated wood composite poles

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Vijaya Gopu; Chung Y. Hse

    2005-01-01

    Wood laminated composite poles consist of trapezoid-shaped wood strips bonded with synthetic resin. The thick-walled hollow poles had adequate strength and stiffness properties and were a promising substitute for solid wood poles. It was necessary to develop theoretical models to facilitate the manufacture and future installation and maintenance of this novel...

  19. Finishing of wood

    Science.gov (United States)

    R. Sam Williams

    1999-01-01

    The primary function of any wood finish (paint, varnish, and stain, for example) is to protect the wood surface, help maintain a certain appearance, and provide a cleanable surface. Although wood can be used both outdoors and indoors without finishing, unfinished wood surfaces exposed to the weather change color, are roughened by photodegradation and surface checking,...

  20. Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after three years of treatments to elevated carbon dioxide and ozone

    Science.gov (United States)

    Seija Kaakinen; Katri Kostiainen; Fredrik Ek; Pekka Saranpaa; Mark E. Kubiske; Jaak Sober; David F. Karnosky; Elina Vapaavuori

    2004-01-01

    The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3-year-old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera...

  1. Who's Counting Dead Wood ?

    OpenAIRE

    Woodall, C. W.; Verkerk, H.; Rondeux, Jacques; Ståhl, G.

    2009-01-01

    Dead wood in forests is a critical component of biodiversity, carbon and nutrient cycles, stand structure, and fuel loadings. Until recently, very few countries have conducted systematic inventories of dead wood resources across their forest lands. This may be changing as an increasing number of countries implement dead wood inventories. A recent survey looks at the status and attributes of forest dead wood inventories in over 60 countries. About 13 percent of countries inventory dead wood gl...

  2. Mechanical properties and chemical composition of beech wood exposed for 30 and 120 days to white-rot fungi

    Science.gov (United States)

    Ehsan Bari; Hamid Reza Taghiyari; Behbood Mohebby; Carol A. Clausen; Olaf Schmidt; Mohammad Ali Tajick Ghanbary; Mohammad Javad Vaseghi

    2015-01-01

    The effects of exposing specimens of Oriental beech [Fagus sylvatica subsp. orientalis (Lipsky) Greuter and Burdet] to the white-rot fungi Pleurotus ostreatus (Jacq.: Fr.) Kummer and Trametes versicolor (L.: Fr.) Pilát strain 325 have been studied concerning the mechanical properties and...

  3. Sources of Confusion in the Determination of ASTM Repetitive Member Factors for the Allowable Properties of Wood Products

    Science.gov (United States)

    S. Verrill; D. Kretschmann

    2012-01-01

    It is generally accepted that there should be an upward repetitive member allowable property adjustment. ASTM D245 (2011c) and ASTM D1990 (2011b) specify a 1.15 factor for allowable bending stress. This factor is also listed in ASTM D6555 (2011a, Table 1). In this technical note, sources of confusion regarding appropriate repetitive member factors are identified. This...

  4. Wood Identification of 18th Century Furniture. Interpreting Wood Naming Inventoires

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-09-01

    Full Text Available The 18th century Portuguese church furniture represents an extraordinary richness recognised worldwide, which demands safeguarding and valorisation. The identification of the wood of furniture artworks is the most important component for its comprehension and preservation. In this work wood anatomical characters of an 18th century Portuguese decorative furniture set from the Colegiada de São Martinho de Cedofeita, in Porto, were analysed to identify the woods used for manufacturing and to clarify their common names. Furthermore, the objectives were to recognise some of the criteria for choice of wood as well as the source of each wood. The woods identified from 16 fragments belong to Apuleia sp., Acacia sp., Neolamarckia sp. and Castanea sativa. Apuleia sp. and Acacia sp. woods most likely arrived from Brazil, while the Neolamarckia sp. woods likely arrived from India and the C. sativa woods from Portugal. The results are in accordance with the known Portuguese colonial sea routes of the 15th -18th centuries. Interestingly the terms found in the inventories can refer to finishing methods instead to the name of the woods, as for instance “oil wood” can refer to “oiled wood” or “linseed oiled wood”. The species choice may be related to the mechanical properties of the wood as well as the original tree size. Two large planks of Acacia sp. were used for the top of the “Portuguese arcaz”, and Apuleia sp. was found on main structural elements of this set of furniture, suggesting that wood colour was also important. Woods from Neolamarckia sp. and C. sativa, were also identified, being Castanea wood present only in the most recent pieces of the furniture set.

  5. Prediction of strength of wood composite materials using ultrasonic

    International Nuclear Information System (INIS)

    Mahmoud, M.K.; Emam, A.

    2005-01-01

    Wood is a biological material integrating a very large variability of its mechanical properties (tensile and compressive), on the two directional longitudinal and transverse Ultrasonic method has been utilized to measure both wood physical and / or wood mechanical properties. The aim of this article is to show the development of ultrasonic technique for quality evaluation of trees, wood material and wood based composites. For quality assessment of these products we discuss the nondestructive evaluation of different factors such as: moisture content, temperature, biological degradation induced by bacterial attack and fungal attack. These techniques were adapted for trees, timber and wood based composites. The present study discusses the prediction of tensile and compressive strength of wood composite materials using ultrasonic testing. Empirical relationships between the tensile properties, compression strength and ultrasonic were proposed. The experimental results indicate the possibility of establishing a relationship between tensile strength and compression values. Moreover, the fractures in tensile and compressive are discussed by photographic

  6. Properties of soils and tree-wood tissue across a Lake States sulfate-deposition gradient. Forest Service resource bulletin

    International Nuclear Information System (INIS)

    Ohmann, L.F.; Grigal, D.F.

    1991-01-01

    There is general concern that atmospheric pollutants may be affecting the health of forests in the USA. The hypotheses tested were that the wet sulfate deposition gradient across the Lake States: (1) is reflected in the amount of accumulated sulfur in the forest floor-soil system and tree woody tissue and (2) is related to differences in tree radial increment. The authors present the properties of the soil and tree woody tissue (mostly chemical) on the study plots. Knowledge of the properties of soil and woody tree tissue is needed for understanding and interpreting relations between sulfate deposition, sulfur accumulation in the ecosystem, soil and tree chemistry, and tree growth and climatic variation. The report provides a summary of those data for study, analysis, and interpretation

  7. Impacts of population structure and analytical models in genome-wide association studies of complex traits in forest trees: a case study in Eucalyptus globulus.

    Directory of Open Access Journals (Sweden)

    Eduardo P Cappa

    Full Text Available The promise of association genetics to identify genes or genomic regions controlling complex traits has generated a flurry of interest. Such phenotype-genotype associations could be useful to accelerate tree breeding cycles, increase precision and selection intensity for late expressing, low heritability traits. However, the prospects of association genetics in highly heterozygous undomesticated forest trees can be severely impacted by the presence of cryptic population and pedigree structure. To investigate how to better account for this, we compared the GLM and five combinations of the Unified Mixed Model ( UMM on data of a low-density genome-wide association study for growth and wood property traits carried out in a Eucalyptus globulus population (n = 303 with 7,680 Diversity Array Technology (DArT markers. Model comparisons were based on the degree of deviation from the uniform distribution and estimates of the mean square differences between the observed and expected p-values of all significant marker-trait associations detected. Our analysis revealed the presence of population and family structure. There was not a single best model for all traits. Striking differences in detection power and accuracy were observed among the different models especially when population structure was not accounted for. The UMM method was the best and produced superior results when compared to GLM for all traits. Following stringent correction for false discoveries, 18 marker-trait associations were detected, 16 for tree diameter growth and two for lignin monomer composition (S:G ratio, a key wood property trait. The two DArT markers associated with S:G ratio on chromosome 10, physically map within 1 Mbp of the ferulate 5-hydroxylase (F5H gene, providing a putative independent validation of this marker-trait association. This study details the merit of collectively integrate population structure and relatedness in association analyses in undomesticated, highly

  8. Impacts of Population Structure and Analytical Models in Genome-Wide Association Studies of Complex Traits in Forest Trees: A Case Study in Eucalyptus globulus

    Science.gov (United States)

    Garcia, Martín N.; Acuña, Cintia; Borralho, Nuno M. G.; Grattapaglia, Dario; Marcucci Poltri, Susana N.

    2013-01-01

    The promise of association genetics to identify genes or genomic regions controlling complex traits has generated a flurry of interest. Such phenotype-genotype associations could be useful to accelerate tree breeding cycles, increase precision and selection intensity for late expressing, low heritability traits. However, the prospects of association genetics in highly heterozygous undomesticated forest trees can be severely impacted by the presence of cryptic population and pedigree structure. To investigate how to better account for this, we compared the GLM and five combinations of the Unified Mixed Model (UMM) on data of a low-density genome-wide association study for growth and wood property traits carried out in a Eucalyptus globulus population (n = 303) with 7,680 Diversity Array Technology (DArT) markers. Model comparisons were based on the degree of deviation from the uniform distribution and estimates of the mean square differences between the observed and expected p-values of all significant marker-trait associations detected. Our analysis revealed the presence of population and family structure. There was not a single best model for all traits. Striking differences in detection power and accuracy were observed among the different models especially when population structure was not accounted for. The UMM method was the best and produced superior results when compared to GLM for all traits. Following stringent correction for false discoveries, 18 marker-trait associations were detected, 16 for tree diameter growth and two for lignin monomer composition (S∶G ratio), a key wood property trait. The two DArT markers associated with S∶G ratio on chromosome 10, physically map within 1 Mbp of the ferulate 5-hydroxylase (F5H) gene, providing a putative independent validation of this marker-trait association. This study details the merit of collectively integrate population structure and relatedness in association analyses in undomesticated, highly

  9. Freshwater Biological Traits Database (Traits)

    Science.gov (United States)

    The traits database was compiled for a project on climate change effects on river and stream ecosystems. The traits data, gathered from multiple sources, focused on information published or otherwise well-documented by trustworthy sources.

  10. Statistical properties of interval mapping methods on quantitative trait loci location: impact on QTL/eQTL analyses

    Directory of Open Access Journals (Sweden)

    Wang Xiaoqiang

    2012-04-01

    Full Text Available Abstract Background Quantitative trait loci (QTL detection on a huge amount of phenotypes, like eQTL detection on transcriptomic data, can be dramatically impaired by the statistical properties of interval mapping methods. One of these major outcomes is the high number of QTL detected at marker locations. The present study aims at identifying and specifying the sources of this bias, in particular in the case of analysis of data issued from outbred populations. Analytical developments were carried out in a backcross situation in order to specify the bias and to propose an algorithm to control it. The outbred population context was studied through simulated data sets in a wide range of situations. The likelihood ratio test was firstly analyzed under the "one QTL" hypothesis in a backcross population. Designs of sib families were then simulated and analyzed using the QTL Map software. On the basis of the theoretical results in backcross, parameters such as the population size, the density of the genetic map, the QTL effect and the true location of the QTL, were taken into account under the "no QTL" and the "one QTL" hypotheses. A combination of two non parametric tests - the Kolmogorov-Smirnov test and the Mann-Whitney-Wilcoxon test - was used in order to identify the parameters that affected the bias and to specify how much they influenced the estimation of QTL location. Results A theoretical expression of the bias of the estimated QTL location was obtained for a backcross type population. We demonstrated a common source of bias under the "no QTL" and the "one QTL" hypotheses and qualified the possible influence of several parameters. Simulation studies confirmed that the bias exists in outbred populations under both the hypotheses of "no QTL" and "one QTL" on a linkage group. The QTL location was systematically closer to marker locations than expected, particularly in the case of low QTL effect, small population size or low density of markers, i

  11. 36 CFR 13.1110 - May I collect or burn interstadial wood?

    Science.gov (United States)

    2010-07-01

    ... interstadial wood? 13.1110 Section 13.1110 Parks, Forests, and Public Property NATIONAL PARK SERVICE... and Preserve General Provisions § 13.1110 May I collect or burn interstadial wood? Collecting or burning interstadial wood (aged wood preserved in glacial deposits) is prohibited. ...

  12. WOOD HEMICELLULOSE/CHITOSAN-BASED SEMI-INTERPENETRATING NETWORK HYDROGELS: MECHANICAL, SWELLING AND CONTROLLED DRUG RELEASE PROPERTIES

    Directory of Open Access Journals (Sweden)

    Muzaffer Ahmet Karaaslan

    2010-04-01

    Full Text Available The cell wall of most plant biomass from forest and agricultural resources consists of three major polymers, cellulose, hemicellulose, and lignin. Of these, hemicelluloses have gained increasing attention as sustainable raw materials. In this study, novel pH-sensitive semi-IPN hydrogels based on hemicelluloses and chitosan were prepared using glutaraldehyde as the crosslinking agent. The hemicellulose isolated from aspen was analyzed for sugar content by HPLC, and its molecular weight distribution was determined by high performance size exclusion chromatography. Results revealed that hemicellulose had a broad molecular weight distribution with a fair amount of polymeric units, together with xylose, arabinose, and glucose. The effects of hemicellulose content on mechanical properties and swelling behavior of hydrogels were investigated. The semi-IPNs hydrogel structure was confirmed by FT-IR, X-ray study, and the ninhydrin assay method. X-ray analysis showed that higher hemicellulose contents yielded higher crystallinity. Mechanical properties were mainly dependent on the crosslink density and average molecular weight between crosslinks. Swelling ratios increased with increasing hemicellulose content and were high at low pH values due to repulsion between similarly charged groups. In vitro release study of a model drug showed that these semi-IPN hydrogels could be used for controlled drug delivery into gastric fluid.

  13. Hydraulic architecture of two species differing in wood density: opposing strategies in co-occurring tropical pioneer trees

    Science.gov (United States)

    Katherine A. McCulloh; Daniel M. Johnson; Frederick C. Meinzer; Steven L. Voelker; Barbara Lachenbruch; Jean-Christophe. Domec

    2012-01-01

    Co-occurring species often have different strategies for tolerating daily cycles of water stress. One underlying parameter that can link together the suite of traits that enables a given strategy is wood density. Here we compare hydraulic traits of two pioneer species from a tropical forest in Panama that differ in wood density: Miconia argentea...

  14. Surface characterization of weathered wood-plastic composites produced from modified wood flour

    Science.gov (United States)

    James S. Fabiyi; Armando G. McDonald; Nicole M. Stark

    2007-01-01

    The effects of weathering on the surface properties of wood-plastic composites (WPC) were examined. High-density polyethylene (HDPE) based WPCs made from modified wood flour (untreated, extractives free, and holocellulose (delignified) fibers) were subjected to accelerated (xenon-arc) weathering. Colorimetry and Fourier-transform infrared spectroscopy were employed to...

  15. Chapter 6: Above Ground Deterioration of Wood and Wood-Based Materials

    Science.gov (United States)

    Grant Kirker; Jerrold Winandy

    2014-01-01

    Wood as a material has unique properties that make it ideal for above ground exposure in a wide range of structural and non-strucutral applications. However, no material is without limitations. Wood is a bio-polymer which is subject to degradative processes, both abiotic and biotic. This chapter is a general summary of the abiotic and biotic factors that impact service...

  16. USE OF CANDEIA’S (Eremanthus erythropappus WASTE WOOD

    Directory of Open Access Journals (Sweden)

    Rosimeire Cavalcante dos Santos

    2008-09-01

    Full Text Available The candeia (Eremanthus erythropappus is a native forest species with multiple uses and specially utilized as essential oils source. The use of the candeia´s waste wood after oil extraction for particle panels production becomes a viable alternative, avoiding environmental problems and increasing the availability of these products in the consuming market. This work verified the viability of producing wood-cement panels using waste wood generated after the extraction of candeia’s oil, in association with pinus and eucalipto woods. The experiment was installed according to a completely randomized design with three repetitions. The treatments were arranged according to a factorial 2 x 3 scheme (two wooden species and three replacement percentages of the woods by candeia’s waste. The results of the physical and mechanical property tests showed high potentiality of candeia waste wood, after oil extraction, in association with pinus and eucalipto wood for manufacturing wood-cement panels.

  17. Still rethinking the value of high wood density.

    Science.gov (United States)

    Larjavaara, Markku; Muller-Landau, Helene C

    2012-01-01

    In a previous paper, we questioned the traditional interpretation of the advantages and disadvantages of high wood density (Functional Ecology 24: 701-705). Niklas and Spatz (American Journal of Botany 97: 1587-1594) challenged the biomechanical relevance of studying properties of dry wood, including dry wood density, and stated that we erred in our claims regarding scaling. We first present the full derivation of our previous claims regarding scaling. We then examine how the fresh modulus of rupture and the elastic modulus scale with dry wood density and compare these scaling relationships with those for dry mechanical properties, using almost exactly the same data set analyzed by Niklas and Spatz. The derivation shows that given our assumptions that the modulus of rupture and elastic modulus are both proportional to wood density, the resistance to bending is inversely proportional to wood density and strength is inversely proportional with the square root of wood density, exactly as we previously claimed. The analyses show that the elastic modulus of fresh wood scales proportionally with wood density (exponent 1.05, 95% CI 0.90-1.11) but that the modulus of rupture of fresh wood does not, scaling instead with the 1.25 power of wood density (CI 1.18-1.31). The deviation from proportional scaling for modulus of rupture is so small that our central conclusion remains correct: for a given construction cost, trees with lower wood density have higher strength and higher resistance to bending.

  18. Use of nanofillers in wood coatings

    DEFF Research Database (Denmark)

    Nikolic, Miroslav; Lawther, John Mark; Sanadi, Anand Ramesh

    2015-01-01

    Wood has been used for thousands of years and remains an important material in the construction industry, most often protected with coatings. Development of nanotechnology allows further improvements or new performance properties to be achieved in wood coatings. Increased UV protection...... with nanometal oxides that allow wood texture to remain seen and higher resilience to scratch and abrasion with use of different nanoparticle shapes are some of the applications that are reviewed here. A variety of possible applications together with a high level of improvements, alongside commercial factors...... like a low level of loading, have already established nanoparticles in some areas of wood coatings. This article is a comprehensive scientific review of the published work in the use of nanofillers in wood coatings....

  19. Radiation processed composite materials of wood and elastic polyester resins

    International Nuclear Information System (INIS)

    Tapolcai, I.; Czvikovszky, T.

    1983-01-01

    The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

  20. Statistical analysis of influence of soil source on leaching of arsenic and copper from CCA-C treated wood

    Science.gov (United States)

    Patricia Lebow; Richard Ziobro; Linda Sites; Tor Schultz; David Pettry; Darrel Nicholas; Stan Lebow; Pascal Kamdem; Roger Fox; Douglas Crawford

    2006-01-01

    Leaching of wood preservatives affects the long-term efficacy and environmental impact of treated wood. Soil properties and wood characteristicscan affectleaching of woad preservatives, but these effects are not well understood. This paper reports a statistical analysis of the effects of soil and wood properties on leaching of arsenic (As) and copper (Cu) from southern...

  1. Mechanics of Wood Machining

    CERN Document Server

    Csanády, Etele

    2013-01-01

    Wood is one of the most valuable materials for mankind, and since our earliest days wood materials have been widely used. Today we have modern woodworking machine and tools; however, the raw wood materials available are continuously declining. Therefore we are forced to use this precious material more economically, reducing waste wherever possible. This new textbook on the “Mechanics of Wood Machining” combines the quantitative, mathematical analysis of the mechanisms of wood processing with practical recommendations and solutions. Bringing together materials from many sources, the book contains new theoretical and experimental approaches and offers a clear and systematic overview of the theory of wood cutting, thermal loading in wood-cutting tools, dynamic behaviour of tool and work piece, optimum choice of operational parameters and energy consumption, the wear process of the tools, and the general regularities of wood surface roughness. Diagrams are provided for the quick estimation of various process ...

  2. Wood's lamp examination

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood lamp examination To use the sharing features on this page, please enable JavaScript. A Wood lamp examination is a test that uses ultraviolet ( ...

  3. Wood's lamp illumination (image)

    Science.gov (United States)

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  4. Robert Wood Johnson Foundation

    Science.gov (United States)

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants ... Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation funds a wide array of programs ...

  5. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    . Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

  6. The TERRA-PNW Dataset: A New Source for Standardized Plant Trait, Forest Carbon Cycling, and Soil Properties Measurements from the Pacific Northwest US, 2000-2014.

    Science.gov (United States)

    Berner, L. T.; Law, B. E.

    2015-12-01

    Plant traits include physiological, morphological, and biogeochemical characteristics that in combination determine a species sensitivity to environmental conditions. Standardized, co-located, and geo-referenced species- and plot-level measurements are needed to address variation in species sensitivity to climate change impacts and for ecosystem process model development, parameterization and testing. We present a new database of plant trait, forest carbon cycling, and soil property measurements derived from multiple TERRA-PNW projects in the Pacific Northwest US, spanning 2000-2014. The database includes measurements from over 200 forest plots across Oregon and northern California, where the data were explicitly collected for scaling and modeling regional terrestrial carbon processes with models such as Biome-BGC and the Community Land Model. Some of the data are co-located at AmeriFlux sites in the region. The database currently contains leaf trait measurements (specific leaf area, leaf longevity, leaf carbon and nitrogen) from over 1,200 branch samples and 30 species, as well as plot-level biomass and productivity components, and soil carbon and nitrogen. Standardized protocols were used across projects, as summarized in an FAO protocols document. The database continues to expand and will include agricultural crops. The database will be hosted by the Oak Ridge National Laboratory (ORLN) Distributed Active Archive Center (DAAC). We hope that other regional databases will become publicly available to help enable Earth System Modeling to simulate species-level sensitivity to climate at regional to global scales.

  7. Adhesive interactions with wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    While the chemistry for the polymerization of wood adhesives has been studied systematically and extensively, the critical aspects of the interaction of adhesives with wood are less clearly understood. General theories of bond formation need to be modified to take into account the porosity of wood and the ability of chemicals to be absorbed into the cell wall....

  8. Soil-wood interactions

    NARCIS (Netherlands)

    Wal, van der Annemieke; klein Gunnewiek, Paulien; Boer, de Wietse

    2017-01-01

    Wood-inhabiting fungi may affect soil fungal communities directly underneath decaying wood via their exploratory hyphae. In addition, differences in wood leachates between decaying tree species may influence soil fungal communities. We determined the composition of fungi in 4-yr old decaying logs

  9. Iron Stain on Wood

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Iron stain, an unsightly blue–black or gray discoloration, can occur on nearly all woods. Oak, redwood, cypress, and cedar are particularly prone to iron stain because these woods contain large amounts of tannin-like extractives. The discoloration is caused by a chemical reaction between extractives in the wood and iron in steel products, such as nails, screws, and...

  10. Wood preservative testing

    Science.gov (United States)

    Rebecca Ibach; Stan T. Lebow

    2012-01-01

    Most wood species used in commercial and residential construction have little natural biological durability and will suffer from biodeterioration when exposed to moisture. Historically, this problem has been overcome by treating wood for outdoor use with toxic wood preservatives. As societal acceptance of chemical use changes, there is continual pressure to develop and...

  11. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Roger M. Rowell

    2010-01-01

    The wood industry can expand into new sustainable markets with the formation of a new class of composites with the marriage of the wood industry and the plastics industry. The wood component, usually a flour or fiber, is combined with a thermoplastic to form an extrudable, injectable or thermoformable composite that can be used in many non-structural applications....

  12. Request for wood samples

    NARCIS (Netherlands)

    NN,

    1977-01-01

    In recent years the wood collection at the Rijksherbarium was greatly expanded following a renewed interest in wood anatomy as an aid for solving classification problems. Staff members of the Rijksherbarium added to the collection by taking interesting wood samples with them from their expeditions

  13. HYGROSCOPICITY OF WOOD PLASTIC COMPOSITES MADE WITH PADOU FLOUR AND POLYPROPYLENE PELLETS

    OpenAIRE

    Moise Emmanuel NZUDJOM SOUOP; Joseph Albert MUKAM FOTSING

    2012-01-01

    The manufacture of objects in wood-plastic composites which is a material already available in many developed countries seems almost unknown in Cameroon since the production factory of objects in wood-plastic composites does not exist up till here. Interested in the study of properties of wood-plastic composites throughconnection of simple plastic and wood, we have oriented our paper in the elaboration, realization and physical characterization of wood-plastic composites with Padou and polypr...

  14. Trait Emotional Intelligence and Personality

    Science.gov (United States)

    Furnham, Adrian; Petrides, K. V.

    2015-01-01

    This study investigated if the linkages between trait emotional intelligence (trait EI) and the Five-Factor Model of personality were invariant between men and women. Five English-speaking samples (N = 307-685) of mostly undergraduate students each completed a different measure of the Big Five personality traits and either the full form or short form of the Trait Emotional Intelligence Questionnaire (TEIQue). Across samples, models predicting global TEIQue scores from the Big Five were invariant between genders, with Neuroticism and Extraversion being the strongest trait EI correlates, followed by Conscientiousness, Agreeableness, and Openness. However, there was some evidence indicating that the gender-specific contributions of the Big Five to trait EI vary depending on the personality measure used, being more consistent for women. Discussion focuses on the validity of the TEIQue as a measure of trait EI and its psychometric properties, more generally. PMID:25866439

  15. Wood frame systems for wood homes

    Directory of Open Access Journals (Sweden)

    Julio Cesar Molina

    2010-12-01

    Full Text Available The use of constructive systems that combine strength, speed, with competitive differential techniques and mainly, compromising with the environment, is becoming more popular in Brazil. The constructive system in wood frame for houses of up to five stories is very interesting, because it is a light system, structured in reforested treated wood which allows the combination of several materials, besides allowing speed in the construction and total control of the expenses already in the project phase for being industrialized. The structural behavior of the wood frame is superior to the structural masonry in strength, thermal and acoustic comfort. However, in Brazil, the wood frame is still little known and used, due to lack of technical knowledge about the system, prejudice associated the bad use of the wood as construction material, or still, in some cases, lack of normalization. The aim of this manuscript consists of presenting the main technical characteristics and advantages of the constructive system in wood frame homes, approaching the main stages of the constructive process through examples, showing the materials used in the construction, in addition the main international normative recommendations of the project. Thus, this manuscript also hopes to contribute to the popularization of the wood frame system in Brazil, since it is a competitive, fast and ecologically correct system. Moreover, nowadays, an enormous effort of the technical, commercial and industrial section has been accomplished for the development of this system in the country.

  16. Comparison of three dielectric barrier discharges regarding their physical characteristics and influence on the adhesion properties on maple, high density fiberboards and wood plastic composite

    International Nuclear Information System (INIS)

    Peters, F; Wieneke, S; Ohms, G; Viöl, W; Hünnekens, B; Militz, H

    2017-01-01

    In this study, three different dielectric barrier discharges, based on the same setup and run with the same power supply, are characterized by emission spectroscopy with regards to the reduced electrical field strength, and the rotational, vibrational and electron temperature. To compare discharges common for the treatment on wood, a coplanar surface barrier discharge, a direct dielectric barrier discharge and a jet system/remote plasma are chosen. To minimize influences due to the setups or power, the discharges are realized with the same electrodes and power supply and normalized to the same power. To evaluate the efficiency of the different discharges and the influence on treated materials, the surface free energy is determined on a maple wood, high density fiberboard and wood plastic composite. The influence is measured depending on the treatment time, with the highest impact in the time of 5 s. (paper)

  17. Comparison of three dielectric barrier discharges regarding their physical characteristics and influence on the adhesion properties on maple, high density fiberboards and wood plastic composite

    Science.gov (United States)

    Peters, F.; Hünnekens, B.; Wieneke, S.; Militz, H.; Ohms, G.; Viöl, W.

    2017-11-01

    In this study, three different dielectric barrier discharges, based on the same setup and run with the same power supply, are characterized by emission spectroscopy with regards to the reduced electrical field strength, and the rotational, vibrational and electron temperature. To compare discharges common for the treatment on wood, a coplanar surface barrier discharge, a direct dielectric barrier discharge and a jet system/remote plasma are chosen. To minimize influences due to the setups or power, the discharges are realized with the same electrodes and power supply and normalized to the same power. To evaluate the efficiency of the different discharges and the influence on treated materials, the surface free energy is determined on a maple wood, high density fiberboard and wood plastic composite. The influence is measured depending on the treatment time, with the highest impact in the time of 5 s.

  18. Laboratory tests on fungal resistance of wood filled polyethylene composites

    Science.gov (United States)

    Craig M. Clemons; Rebecca E. Ibach

    2002-01-01

    A standard method for determining the durability of structural wood was modified for testing the fungal resistance of composites made from high density polyethylene filled with 50% wood flour. Moisture content, mechanical properties, and weight loss were measured over 12 weeks exposure to brown-and white-rot fungi. Mechanical properties were decreased, but irreversible...

  19. Influence of extractives on wood gluing and finishing- a review

    Science.gov (United States)

    Chung-Yun Hse; Mon-Lin Kuo

    1988-01-01

    Migration of extractives to the wood surface alters the properties of wood as an adherent. Extractives change the wettability and the curing properties of adhesives. A desirable wettability-permeability relationship is sometimes affected by extractives, thus reducing the gluebond strength and performance. Past efforts to determine which of the components of extractives...

  20. New handbook for standardised measurement of plant functional traits worldwide.

    NARCIS (Netherlands)

    Perez-Harguindeguy, N.; Diaz, S.; Garnier, E.; Lavorel, S.; Poorter, H.; Jaureguiberry, P.; Bret-Harte, M.S.; Cornwell, W.K.; Craine, J.M.; Gurvich, D.E.; Urcelay, C.; Veneklaas, E.J.; Reich, P.B.; Poorter, L.; Wright, I.J.; Ray, P.; Enrico, L.; Pausas, J.G.; de Vos, A.C.; Buchmann, N.; Funes, G.; Quetier, F.; Hodgson, J.G.; Thompson, K.; Morgan, H.D.; ter Steege, H.; van der Heijden, M.G.A.; Sack, L.; Blonder, B.; Poschlod, P.; Vaieretti, M.V.; Conti, G.; Staver, A.C.; Aquino, S.; Cornelissen, J.H.C.

    2013-01-01

    Plant functional traits are the features (morphological, physiological, phenological) that represent ecological strategies and determine how plants respond to environmental factors, affect other trophic levels and influence ecosystem properties. Variation in plant functional traits, and trait

  1. Effect of Alternative Wood Species and First Thinning Wood on Oriented Strand Board Performance

    Directory of Open Access Journals (Sweden)

    Fabiane Salles Ferro

    2018-01-01

    Full Text Available This study aimed to evaluate the feasibility of using and influence of alternative wood species such as Cambará, Paricá, Pinus, and wood from first thinning operations on oriented strand board (OSB physical and mechanical properties. Besides that, an alternative resin, castor oil-based polyurethane, was used to bond the particles, due to the better environmental performance when compared to other resins commonly used worldwide in OSB production. Physical properties such as the moisture content, thickness swelling, and water absorption, both after 2 and 24 hours of water immersion, and mechanical properties such as the modulus of elasticity and resistance in static bending, in major and minor axes, and internal bonding were investigated. All tests were performed according to European code EN 300:2006. Results showed the influence of wood species on physical and mechanical properties. Panels made with higher density woods such as Cambará presented better physical performance, while those made with lower density woods such as Pinus presented better mechanical properties. Besides that, strand particle geometry was also influenced on all physical and mechanical properties investigated. Therefore, the feasibility of using alternative species and wood from first thinning and with castor oil-based polyurethane resin in OSB production was verified.

  2. Properties of Seven Colombian Woods.

    Science.gov (United States)

    1981-01-01

    differences. 1971. AIgunas propiedades fisicas y mecanicas de tres Maderas Colom- Cuangare and sande had the lowest bianas. Universidad Distrital "Francisco...Jose De Caldas" Instituto de and highest figures, respectively, for Investigaciones y Proyectos Forestales y Madereros. Bogota, Colombia. bending...to 45 pounds per 1970. Estudio de preinversion para el desar- cubic foot. Basic specific gravity from this study rollo forestal de la Guyana

  3. Wood property variation in Populus

    Science.gov (United States)

    Dean W. Einspahr; Miles K. Benson; John R. Peckham

    1968-01-01

    The use of bigtooth aspen (Populus grandidentata Michx.), quaking aspen (P. tremuloides Michx.), and cottonwood (P. deltoides Bartr.) by the pulp and paper industry has increased greatly during the past decade. This expanded use has stimulated research on the genetic improvement of Populus. For the past 12 years...

  4. Fluorescing macerals from wood precursors

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S A; Bensley, D F

    1987-01-01

    A preliminary investigation into the origin of wood-derived macerals has established the existence of autofluorescent maceral precursors in the secondary xylem of swamp-inhabiting plant species. The optical character and fluorescent properties of microtomed thin-sections of modern woods from the Florida Everglades and Okefenokee Swamp, Georgia are compared to the character and properties of their peatified equivalents from various Everglades and Okefenokee peat horizons and their lignitic equivalents from the Brandon lignite of Vermont and the Trail Ridge lignitic peat from northern Florida. The inherent fluorescence of woody cell walls is believed to be caused by lignin though other cell wall components may contribute. The fluorescence spectra for several wood and cell types had a ..gamma../sub m//sub a//sub x/ of 452 nm and Q value of 0.00. The color as observed in blue light and the spectral geometry as measured in UV light of peatified and lignitic woody cell walls (potential textinites) may change progressively during early coalification. Cell wall-derived maceral material is shown to maintain its fluorescing properties after being converted to a structureless material, perhaps a corpohuminite or humodetrinite precursor. Fluorescing xylem cell contents, such as condensed tannins or essential oils, can maintain the fluorescent character through early coalification. Xylem cell walls and xylem cell contents are shown to provide fluorescing progenitor materials which would not require subsequent infusion with 'lipid' materials to account for their fluorescence as phytoclast material or as macerals in coal. 35 references.

  5. Variação, divergência e correlações genéticas entre caracteres silviculturais e densidade básica da madeira em progênies de Myracrodruon urundeuva (Engler Fr. Allem. Genetic variation, divergence and correlations among silvicultural traits and wood density in progenies of Myracrodruon urundeuva (Engler Fr. Allem.

    Directory of Open Access Journals (Sweden)

    Eduardo Luiz LONGUI

    2011-06-01

    State, genetic parameters for wood density in three radials positions (pith, intermediary and bark, the Mahalanobis distance and genetic and phenotypic correlations between growth traits (total height, stem height and diameter at breast height – DBH and wood density were estimated. The population presented high wood density (0.75 g.cm-3 and heritability (0.64 for this trait in the medulla and intermediary positions, indicating strong genetic control and the possibility of improvement by selection. The results also showed that for the studied M. urundeuva populations, the progenies 1 and 14 must be used to explore the heterotic effects because these progenies presented the highest Mahalanobis distance; in contrast, the progenies 14 and 20 presented the lowest genetic distance and thus, the breeding may be obtained for backcross. These information are important to choose adequate methods of breeding and conservations genetics.

  6. Study on the Effect of Heat Treatment on Physical Properties of Poplar and Beech Woods Impregnated with Nano-Copper and Nano-Silver

    Directory of Open Access Journals (Sweden)

    Hassan Siahposht

    2012-06-01

    Full Text Available Present study conducted to review effects of heat treatment on weight loss, water adsorption, and thickness swelling of poplar (Populus nigra and beech (Fagus oreintalis woods impregnated with nano-copper and nano-silver. Specimens werepressur (2.5 bar impregnated with 400 PPM water-based solution of nano-copper and nano-silver particles in a pressure vessel. For heat treatment, nano-cupper,  nano-silver impregnated and control specimens, were heat treated at 145°C temperature for 24 hours. Water absorption and thickness swelling decreased in heat treated and nano-heat treated specimens and this decrease in specimens impregnated with nano-copper and nano-silver was more obvious than in heat treated control specimens. The reasons were the degradation in crystal sections of celluloses chains and the ink variation of wood polymers. On the other hand, a comparison between heat treated and nano- heat treated specimens has shown weight loss further in nano-heat treated specimens. This shows that retent nano-copper and nano-silver by impregnation facilitates heat transfer in wood; and it may increase the process of degradation and pyrolysis of wood structures in inner parts of specimens.

  7. Improvements in processing characteristics and engineering properties of wood flour-filled high density polyethylene composite sheeting in the presence of hollow glass microspheres

    Science.gov (United States)

    Baris Yalcin; Steve E Amos; Andrew S D Souza; Craig M Clemons; I Sedat Gunes; Troy K Ista

    2012-01-01

    Hollow glass microspheres were introduced into wood flour/high density polyethylene composites by melt compounding in a twin-screw extruder. The prepared composites were subsequently converted to extruded profiles in order to obtain composite sheeting. The presence of hollow glass microspheres highly reduced the density of the extruded sheets down to 0.9 g/cc, while...

  8. Synthesis, characterization, and wear and friction properties of variably structured SiC/Si elements made from wood by molten Si impregnation

    DEFF Research Database (Denmark)

    Dhiman, Rajnish; Rana, Kuldeep; Bengu, Erman

    2012-01-01

    We have synthesized pre-shaped SiC/Si ceramic material elements from charcoal (obtained from wood) by impregnation with molten silicon, which takes place in a two-stage process. In the first process, a porous structure of connected micro-crystals of β-SiC is formed, while, in the second process...

  9. Plant traits, productivity, biomass and soil properties from forest sites in the Pacific Northwest, 1999–2014

    Science.gov (United States)

    Berner, Logan T.; Law, Beverly E.

    2016-01-01

    Plant trait measurements are needed for evaluating ecological responses to environmental conditions and for ecosystem process model development, parameterization, and testing. We present a standardized dataset integrating measurements from projects conducted by the Terrestrial Ecosystem Research and Regional Analysis- Pacific Northwest (TERRA-PNW) research group between 1999 and 2014 across Oregon and Northern California, where measurements were collected for scaling and modeling regional terrestrial carbon processes with models such as Biome-BGC and the Community Land Model. The dataset contains measurements of specific leaf area, leaf longevity, leaf carbon and nitrogen for 35 tree and shrub species derived from more than 1,200 branch samples collected from over 200 forest plots, including several AmeriFlux sites. The dataset also contains plot-level measurements of forest composition, structure (e.g., tree biomass), and productivity, as well as measurements of soil structure (e.g., bulk density) and chemistry (e.g., carbon). Publically-archiving regional datasets of standardized, co-located, and geo-referenced plant trait measurements will advance the ability of earth system models to capture species-level climate sensitivity at regional to global scales. PMID:26784559

  10. Plant traits, productivity, biomass and soil properties from forest sites in the Pacific Northwest, 1999-2014

    Science.gov (United States)

    Berner, Logan T.; Law, Beverly E.

    2016-01-01

    Plant trait measurements are needed for evaluating ecological responses to environmental conditions and for ecosystem process model development, parameterization, and testing. We present a standardized dataset integrating measurements from projects conducted by the Terrestrial Ecosystem Research and Regional Analysis- Pacific Northwest (TERRA-PNW) research group between 1999 and 2014 across Oregon and Northern California, where measurements were collected for scaling and modeling regional terrestrial carbon processes with models such as Biome-BGC and the Community Land Model. The dataset contains measurements of specific leaf area, leaf longevity, leaf carbon and nitrogen for 35 tree and shrub species derived from more than 1,200 branch samples collected from over 200 forest plots, including several AmeriFlux sites. The dataset also contains plot-level measurements of forest composition, structure (e.g., tree biomass), and productivity, as well as measurements of soil structure (e.g., bulk density) and chemistry (e.g., carbon). Publically-archiving regional datasets of standardized, co-located, and geo-referenced plant trait measurements will advance the ability of earth system models to capture species-level climate sensitivity at regional to global scales.

  11. Wood density and anatomy of three Eucalyptus species: implications for hydraulic conductivity

    OpenAIRE

    Barotto, Antonio J.; Monteoliva, Silvia; Gyenge, Javier; Martínez-Meier, Alejandro; Moreno, Karen; Tesón, Natalia; Fernández, María Elena

    2017-01-01

    Aim of the study: To characterize wood anatomical traits of three Eucalyptus species that differ in wood density and ecological requirements, and to examine the relationships between some anatomical features, wood density, and theoretical xylem hydraulic conductivity (Ks).Area of study: We analyzed 86 trees from three sites of Argentina (Entre Ríos and Buenos Aires Provinces).Methods: The sampled trees were Eucalyptus globulus, E. grandis and E. viminalis ranging from 11 to 15 years old. One ...

  12. Wood density and anatomy of three Eucalyptus species: implications for hydraulic conductivity

    OpenAIRE

    Antonio J. Barotto; Silvia Monteoliva; Javier Gyenge; Alejandro Martínez-Meier; Karen Moreno; Natalia Tesón; María Elena Fernández

    2017-01-01

    Aim of the study: To characterize wood anatomical traits of three Eucalyptus species that differ in wood density and ecological requirements, and to examine the relationships between some anatomical features, wood density, and theoretical xylem hydraulic conductivity (Ks). Area of study: We analyzed 86 trees from three sites of Argentina (Entre Ríos and Buenos Aires Provinces). Methods: The sampled trees were Eucalyptus globulus, E. grandis and E. viminalis ranging from 11 to 15 years...

  13. Estudo de algumas propriedades mecânicas da madeira de um híbrido clonal de Eucalyptus urophylla X Eucalyptus grandis Study of some mechanical properties of wood in a clonal hybrid of Eucalyptus urophylla X Eucalyptus grandis

    Directory of Open Access Journals (Sweden)

    Fabrício Gomes Gonçalves

    2009-06-01

    Full Text Available A procura por madeiras oriundas de reflorestamentos destinadas à serraria é uma realidade já há muitos anos, principalmente aquelas das espécies do gênero Eucalyptus. Visando buscar novas informações importantes para esse mercado, este trabalho objetivou determinar algumas propriedades mecânicas da madeira de um híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis de duas idades e provenientes de talhadia simples e de reforma. Os resultados indicaram que a madeira desse híbrido apresenta boas características tecnológicas, destacando-se a segunda tora (a partir de 3 m com as melhores propriedades de flexão estática (Módulo de Elasticidade - MOE e Módulo de Ruptura - MOR e Compressão Axial das fibras. As árvores de maior idade (166 meses e que sofreram dois desbastes apresentaram as melhores propriedades de flexão estática e compressão axial.The search for wood originated from reforestations destined to sawmill has been observed for many years, mainly for the Eucalyptus species. Searching for information to assist this market, the aim of this study was to determine some mechanical properties of the wood from a Eucalyptus urophylla x Eucalyptus grandis clonal hybrid, at two different ages and coming from coppice and reform. The results show that the wood of this clonal hybrid presents good technological characteristics and is the second best log (starting from 3,0 m, as to static bending properties (Module of Elasticity - MOE and Module of Rupture - MOR. The oldest trees (166 months - E2 which suffered two thinning presented the best results for the property of static bending and axial crushing (CA.

  14. Evaluation of wood species and preservatives for WisDOT sign posts.

    Science.gov (United States)

    2013-10-01

    The Wisconsin Department of Transportation (WisDOT) uses preservative-treated wood posts for much of the signage along state highways because wood is relatively inexpensive, easy to install, and has the necessary strength properties to tolerate typic...

  15. Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

    Science.gov (United States)

    Civardi, Chiara; Van den Bulcke, Jan; Schubert, Mark; Michel, Elisabeth; Butron, Maria Isabel; Boone, Matthieu N; Dierick, Manuel; Van Acker, Joris; Wick, Peter; Schwarze, Francis W M R

    2016-01-01

    The North American wood decking market mostly relies on easily treatable Southern yellow pine (SYP), which is being impregnated with micronized copper (MC) wood preservatives since 2006. These formulations are composed of copper (Cu) carbonate particles (CuCO3·Cu(OH)2), with sizes ranging from 1 nm to 250 μm, according to manufacturers. MC-treated SYP wood is protected against decay by solubilized Cu2+ ions and unreacted CuCO3·Cu(OH)2 particles that successively release Cu2+ ions (reservoir effect). The wood species used for the European wood decking market differ from the North American SYP. One of the most common species is Norway spruce wood, which is poorly treatable i.e. refractory due to the anatomical properties, like pore size and structure, and chemical composition, like pit membrane components or presence of wood extractives. Therefore, MC formulations may not suitable for refractory wood species common in the European market, despite their good performance in SYP. We evaluated the penetration effectiveness of MC azole (MCA) in easily treatable Scots pine and in refractory Norway spruce wood. We assessed the effectiveness against the Cu-tolerant wood-destroying fungus Rhodonia placenta. Our findings show that MCA cannot easily penetrate refractory wood species and could not confirm the presence of a reservoir effect.

  16. Protection of Wood from Microorganisms by Laccase-Catalyzed Iodination

    Science.gov (United States)

    Engel, J.; Thöny-Meyer, L.; Schwarze, F. W. M. R.; Ihssen, J.

    2012-01-01

    In the present work, Norway spruce wood (Picea abies L.) was reacted with a commercial Trametes versicolor laccase in the presence of potassium iodide salt or the phenolic compounds thymol and isoeugenol to impart an antimicrobial property to the wood surface. In order to assess the efficacy of the wood treatment, a leaching of the iodinated and polymerized wood and two biotests including bacteria, a yeast, blue stain fungi, and wood decay fungi were performed. After laccase-catalyzed oxidation of the phenols, the antimicrobial effect was significantly reduced. In contrast, the enzymatic oxidation of iodide (I−) to iodine (I2) in the presence of wood led to an enhanced resistance of the wood surface against all microorganisms, even after exposure to leaching. The efficiency of the enzymatic wood iodination was comparable to that of a chemical wood preservative, VP 7/260a. The modification of the lignocellulose by the laccase-catalyzed iodination was assessed by the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) technique. The intensities of the selected lignin-associated bands and carbohydrate reference bands were analyzed, and the results indicated a structural change in the lignin matrix. The results suggest that the laccase-catalyzed iodination of the wood surface presents an efficient and ecofriendly method for wood protection. PMID:22865075

  17. X-ray initiated polymerization of wood impregnants

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, Marshall R.; Galloway, Richard A. [IBA Industrial, Inc., Edgewood, NY (United States); Berejka, Anthony J. [Ionicorp, Huntington, NY 11743 (United States)], E-mail: berejka@msn.com; Montoney, Daniel [Strathmore Products, Syracuse, NY (United States); Driscoll, Mark; Smith, Leonard; Scott Larsen, L. [State University of New York, SUNY-ESF, Syracuse, NY (United States)

    2009-07-15

    X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

  18. X-ray initiated polymerization of wood impregnants

    International Nuclear Information System (INIS)

    Cleland, Marshall R.; Galloway, Richard A.; Berejka, Anthony J.; Montoney, Daniel; Driscoll, Mark; Smith, Leonard; Scott Larsen, L.

    2009-01-01

    X-rays, derived from a high energy, high-current electron beam (EB), initiated in-situ polymerization of a unique class of monomers that were found to penetrate the cell walls of wood. X-rays initiated an auto-catalytic acrylic polymerization and penetrated through thick pieces of wood. The final cured product having the polymerizate, a polymer, both in the wood cell lumens and in the cell walls is called wood impregnated with a wood-polymer penetrant (WPP). The controlled lower dose rate of X-rays overcame disproportionation encountered when using higher dose-rate electron beam initiation. With X-rays, the in-situ polymerization took place in one exposure of modest dose. With EB, multiple passes were needed to avoid excessive heat build-up and monomer volatilization. Having entered the cell walls of the wood and then being polymerized within the cell walls, these radiation-cured unique monomers imparted outstanding dimensional stability upon exposure of the impregnated wood to humidity cycling. The preferred monomer system was also chemically modified prior to impregnation with agents that would remain in the wood and prevent the growth of fungi and other microbials. This technique differs from historic uses of monomers that merely filled the lumens of the wood (historic wood-polymer composites), which are only suitable for indoor use. The WPP impregnated wood that was either X-ray cured or EB cured demonstrated enhanced structural properties, dimensional stability, and decay resistance.

  19. Bacterial Community Succession in Pine-Wood Decomposition.

    Science.gov (United States)

    Kielak, Anna M; Scheublin, Tanja R; Mendes, Lucas W; van Veen, Johannes A; Kuramae, Eiko E

    2016-01-01

    Though bacteria and fungi are common inhabitants of decaying wood, little is known about the relationship between bacterial and fungal community dynamics during natural wood decay. Based on previous studies involving inoculated wood blocks, strong fungal selection on bacteria abundance and community composition was expected to occur during natural wood decay. Here, we focused on bacterial and fungal community compositions in pine wood samples collected from dead trees in different stages of decomposition. We showed that bacterial communities undergo less drastic changes than fungal communities during wood decay. Furthermore, we found that bacterial community assembly was a stochastic process at initial stage of wood decay and became more deterministic in later stages, likely due to environmental factors. Moreover, composition of bacterial communities did not respond to the changes in the major fungal species present in the wood but rather to the stage of decay reflected by the wood density. We concluded that the shifts in the bacterial communities were a result of the changes in wood properties during decomposition and largely independent of the composition of the wood-decaying fungal communities.

  20. Bacterial community succession in pine-wood decomposition

    Directory of Open Access Journals (Sweden)

    Anna eKielak

    2016-03-01

    Full Text Available Though bacteria and fungi are common inhabitants of decaying wood, little is known about the relationship between bacterial and fungal community dynamics during natural wood decay. Based on previous studies involving inoculated wood blocks, strong fungal selection on bacteria abundance and community composition was expected to occur during natural wood decay. Here we focused on bacterial and fungal community compositions in pine wood samples collected from dead trees in different stages of decomposition. We showed that bacterial communities undergo less drastic changes than fungal communities during wood decay. Furthermore, we found that bacterial community assembly was a stochastic process at initial stage of wood decay and became more deterministic in later stages, likely due to environmental factors. Moreover, composition of bacterial communities did not respond to the changes in the major fungal species present in the wood but rather to the stage of decay reflected by the wood density. We concluded that the shifts in the bacterial communities were a result of the changes in wood properties during decomposition and largely independent of the composition of the wood-decaying fungal communities.

  1. Many Roles of Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart

    2014-01-01

    Although wood bonding is one of the oldest applications of adhesives, going back to early recorded history (1), some aspects of wood bonds are still not fully understood. Most books in the general area of adhesives and adhesion do not cover wood bonding. However, a clearer understanding of wood bonding and wood adhesives can lead to improved products. This is important...

  2. Urban Wood Waste Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wiltsee, G.

    1998-11-20

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

  3. Controversy. The wood war

    International Nuclear Information System (INIS)

    James, O.

    2010-01-01

    The author comments the conflict emerging in France between industries exploiting wood for construction and those exploiting it as a heating material for power generation. The first ones accuse the others to steal their raw material, to pull the prices up, and to destabilize the sector. This conflict takes place notably around sawmill wastes which are used either by wood panel fabricators or by wood pellets producers. Both sectors are claiming they are creating more jobs than the other. The French forest indeed offers good opportunities for both sectors, but other countries which are lacking forest surfaces, are buying wood in France. Several issues are matter of discussion: burning wood seems to go against the reduction of greenhouse gas emissions, subsidies awarded to big heater projects. The situation of the wood sector in Austria, Finland and Poland is briefly presented

  4. Functional lignocellulosic materials prepared by ATRP from a wood scaffold

    Science.gov (United States)

    Cabane, Etienne; Keplinger, Tobias; Künniger, Tina; Merk, Vivian; Burgert, Ingo

    2016-01-01

    Wood, a natural and abundant source of organic polymers, has been used as a scaffold to develop novel wood-polymer hybrid materials. Through a two-step surface-initiated Atom Transfer Radical Polymerization (ATRP), the porous wood structure can be effectively modified with polymer chains of various nature. In the present study, polystyrene and poly(N-isopropylacrylamide) were used. As shown with various characterization techniques including confocal Raman microscopy, FTIR, and SEM/EDX, the native wood ultrastructure and features are retained and the polymer chains can be introduced deep within the wood, i.e. inside the wood cell walls. The physical properties of the new materials have been studied, and results indicate that the insertion of polymer chains inside the wood cell wall alters the intrinsic properties of wood to yield a hybrid composite material with new functionalities. This approach to the functionalization of wood could lead to the fabrication of a new class of interesting functional materials and promote innovative utilizations of the renewable resource wood. PMID:27506369

  5. Chapter 9: Wood Energy

    Science.gov (United States)

    Francisco X. Aguilar; Karen Abt; Branko Glavonjic; Eugene Lopatin; Warren  Mabee

    2016-01-01

    The availabilty of information on wood energy continues to improve, particularly for commoditized woodfuels.  Wood energy consumption and production vary in the UNECE region because demand is strngly affected by weather and the prices of competing energy sources.  There has been an increase in wood energy in the power-and-heat sector in the EU28 and North American...

  6. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  7. Creation of Wood Dust during Wood Processing: Size Analysis, Dust Separation, and Occupational Health

    Directory of Open Access Journals (Sweden)

    Eva Mračková

    2015-11-01

    Full Text Available Mechanical separators and fabric filters are being used to remove airborne fine particles generated during the processing and handling of wood. Such particles might have a harmful effect on employee health, not only in small- but also in large-scale wood processing facilities. The amount of wood dust and its dispersion conditions vary according to geometric boundary conditions. Thus, the dispersion conditions could be changed by changing the linear size of the particles. Moreover, the smaller the particles are, the more harmful they can be. It is necessary to become familiar with properties, from a health point of view, of wood dust generated from processing. Wood dust has to be sucked away from the processing area. The fractional separation efficiency of wood dust can be improved using exhaust and filtering devices. Filtration efficiency depends on moisture content, particle size, and device performance. Because of the carcinogenicity of wood dust, the concentration of wood dust in air has to be monitored regularly. Based on the results hereof, a conclusion can be made that both mechanical separators of types SEA and SEB as well as the fabric filters with FINET PES 1 textile are suitable for the separation of wet saw dust from all types of wooden waste produced within the process.

  8. Moisture-driven fracture in solid wood

    DEFF Research Database (Denmark)

    Larsen, Finn; Ormarsson, Sigurdur; Olesen, John Forbes

    2011-01-01

    Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood and with the crac......Moisture-induced fractures in solid timber create considerable problems for both building industries and sawmills. Cracks caused by kiln-drying of solid timber are extremely difficult to predict. This paper reports on experiments concerned with methods of reducing cracks in wood...... process, suggesting that sealing the ends of timber logs while in the green moisture state could considerably reduce the development of end-cracks. The initial moisture content and the shrinkage properties of the wood varied markedly from pith to bark. The importance of taking material inhomogeneities...... into account when modelling crack propagation in solid wood is emphasized. © 2011 Taylor & Francis....

  9. PHYSICAL ANALYSIS OF QUALITY WOOD Melia azedarach

    Directory of Open Access Journals (Sweden)

    T. J. da Silva

    2016-07-01

    Full Text Available Forest species, in general, present a slow growth, which results and profits can manifest themselves in the long run, it becomes necessary the study and discovery of new species that may provide raw materials and return on invested capital more immediate, being that the Melia azedarach wood is a potential option. In the absence of information about, the objective of this paper is to determine its physical properties: basic density and shrinkage of the Melia azedarach species in the Itapeva-SP region. The data obtained in this study allow to classify wood Melia azedarach as wood of average density and good dimensional stability. Feature that makes it ideal for its use in furniture industry. The low amount of research related to quality of this wood prevents the commercial use of it to achieve its full potential harnessing its effectively, and essential investments in this field.

  10. Wood pellet seminar

    International Nuclear Information System (INIS)

    Aarniala, M.; Puhakka, A.

    2001-01-01

    The objective of the wood pellet seminar, arranged by OPET Finland and North Karelia Polytechnic, was to deliver information on wood pellets, pellet burners and boilers, heating systems and building, as well as on the activities of wood energy advisors. The first day of the seminar consisted of presentations of equipment and products, and of advisory desks for builders. The second day of the seminar consisted of presentations held by wood pellet experts. Pellet markets, the economy and production, the development of the pellet markets and their problems (in Austria), the economy of heating of real estates by different fuel alternatives, the production, delivery and marketing of wood pellets, the utilization of wood pellet in different utilization sites, the use of wood pellets in detached houses, pellet burners and fireplaces, and conversion of communal real estate houses to use wood pellets were discussed in the presentations. The presentations held in the third day discussed the utilization of wood pellets in power plants, the regional promotion of the production and the use of pellets. The seminar consisted also of visits to pellet manufacturing plant and two pellet burning heating plants

  11. Study of the effect of gamma radiation on some physical-mechanical properties of wood used in Brazilian cultural and artistic heritage; Estudo do efeito da radiacao gama sobre algumas propriedades fisico-mecanicas de madeiras usadas em patrimonios artisticos e culturais brasileiros

    Energy Technology Data Exchange (ETDEWEB)

    Severiano, Lucio Cesar

    2010-07-01

    Wood is considered a natural composite of extreme complexity, basically composed by cellulose, lignin, hemicellulose (polyosis) and extractives. Its composition favors biological attacks from different species. In this context, several techniques have been studied and applied for disinfecting and decontaminating wood-made works of art and cultural heritage, which have been damaged by fungi, bacteria and insects. Gamma radiation emitted by unstable isotopes, such as 60- cobalt, has also been studied as an alternative to the conventional wood preservatives. So, gamma rays treatment has been shown to be efficient to the removal of infestations by insects and microorganisms in wood-made artifacts, to be fast and not to require quarantine because it does not generate toxic waste. Similar to other techniques, this process does not prevent the irradiated material of re-infestation or recontamination. In this context, the effects of relatively high disinfestation gamma radiation doses (up to 100 kGy) on cedro rosa and imbuia, two typical Brazilian wood species, are accompanied by the changes on the following attributes: apparent density, retracting, parallel compression to fibers, bending in the modulus of elasticity, hardness, shear and thermal stability. Results have shown that gamma radiation, in the studied dose range, does not promote alterations on properties of investigated wood species. In case of a re-infestation, these observations indicate that the wood species can be submitted to repeatedly irradiation processes without causing damage to their structure up to the studied dose range, in despite of radiation effects be always cumulative. (author)

  12. Patterns in hydraulic architecture from roots to branches in six tropical tree species from cacao agroforestry and their relation to wood density and stem growth.

    Science.gov (United States)

    Kotowska, Martyna M; Hertel, Dietrich; Rajab, Yasmin Abou; Barus, Henry; Schuldt, Bernhard

    2015-01-01

    For decades it has been assumed that the largest vessels are generally found in roots and that vessel size and corresponding sapwood area-specific hydraulic conductivity are acropetally decreasing toward the distal twigs. However, recent studies from the perhumid tropics revealed a hump-shaped vessel size distribution. Worldwide tropical perhumid forests are extensively replaced by agroforestry systems often using introduced species of various biogeographical and climatic origins. Nonetheless, it is unknown so far what kind of hydraulic architectural patterns are developed in those agroforestry tree species and which impact this exerts regarding important tree functional traits, such as stem growth, hydraulic efficiency and wood density (WD). We investigated wood anatomical and hydraulic properties of the root, stem and branch wood in Theobroma cacao and five common shade tree species in agroforestry systems on Sulawesi (Indonesia); three of these were strictly perhumid tree species, and the other three tree species are tolerating seasonal drought. The overall goal of our study was to relate these properties to stem growth and other tree functional traits such as foliar nitrogen content and sapwood to leaf area ratio. Our results confirmed a hump-shaped vessel size distribution in nearly all species. Drought-adapted species showed divergent patterns of hydraulic conductivity, vessel density, and relative vessel lumen area between root, stem and branch wood compared to wet forest species. Confirming findings from natural old-growth forests in the same region, WD showed no relationship to specific conductivity. Overall, aboveground growth performance was better predicted by specific hydraulic conductivity than by foliar traits and WD. Our study results suggest that future research on conceptual trade-offs of tree hydraulic architecture should consider biogeographical patterns underlining the importance of anatomical adaptation mechanisms to environment.

  13. Preliminary studies of Brazilian wood using different radioisotopic sources

    International Nuclear Information System (INIS)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e

    2013-01-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  14. Effects of Chemical Curing Temperature and Time on the Properties of Liquefied Wood based As-cured Precursors and Carbon Fibers

    Directory of Open Access Journals (Sweden)

    Junbo Shang

    2015-09-01

    Full Text Available Liquefied wood based as-cured precursors and carbon fibers prepared by different chemical curing processes were carried out to investigate the effects of curing temperature and time on the thermostability and microstructure of liquefied wood based precursors, the tensile strength of carbon fibers as well. The primary fibers can be converted into precursors with high performance by directly heating at target curing temperature. With the temperature and duration increasing, the numbers of methylene bonds in precursors increased, resulting in the enhancement of cross-linkages among molecular chains and then the improvement of thermostability of precursors. Carbon fibers prepared from as-cured precursors (curing temperature 95 oC, curing time 3h had the minimum value of the average interlayer spacing (d002, it also showed the highest tensile strength, almost 800 MPa, which can be classified as fibers of general grade.

  15. PHYTOALEXIN DEFICIENT 4 affects reactive oxygen species metabolism, cell wall and wood properties in hybrid aspen (Populus tremula L. × tremuloides).

    Science.gov (United States)

    Ślesak, Ireneusz; Szechyńska-Hebda, Magdalena; Fedak, Halina; Sidoruk, Natalia; Dąbrowska-Bronk, Joanna; Witoń, Damian; Rusaczonek, Anna; Antczak, Andrzej; Drożdżek, Michał; Karpińska, Barbara; Karpiński, Stanisław

    2015-07-01

    The phytoalexin deficient 4 (PAD4) gene in Arabidopsis thaliana (AtPAD4) is involved in the regulation of plant--pathogen interactions. The role of PAD4 in woody plants is not known; therefore, we characterized its function in hybrid aspen and its role in reactive oxygen species (ROS)-dependent signalling and wood development. Three independent transgenic lines with different suppression levels of poplar PAD expression were generated. All these lines displayed deregulated ROS metabolism, which was manifested by an increased H2O2 level in the leaves and shoots, and higher activities of manganese superoxide dismutase (MnSOD) and catalase (CAT) in the leaves in comparison to the wild-type plants. However, no changes in non-photochemical quenching (NPQ) between the transgenic lines and wild type were observed in the leaves. Moreover, changes in the ROS metabolism in the pad4 transgenic lines positively correlated with wood formation. A higher rate of cell division, decreased tracheid average size and numbers, and increased cell wall thickness were observed. The results presented here suggest that the Populus tremula × tremuloides PAD gene might be involved in the regulation of cellular ROS homeostasis and in the cell division--cell death balance that is associated with wood development. © 2014 John Wiley & Sons Ltd.

  16. Influence of microfibril angle on the thermal and dynamic-mechanical properties of Acacia Mangium wood using X-ray diffraction and dynamics-mechanical test

    International Nuclear Information System (INIS)

    Tabet, T.A.; Julynnie Wajir; Fauziah Abdul Aziz

    2009-01-01

    The term microfibril angle, MFA in wood science refers to the angle between the direction of the helical windings of cellulose microfibrils in the secondary cell wall, S 2 layer of fibers and tracheids and the long axis of the cell. In this study, the mean MFA of the cell walls were determined for thin samples of thickness 200.0 μm from pith and outwards, for eight ages of Acacia Mangium wood. The determination of MFA was based on a diffraction pattern arising from cellulose crystal planes of the type 002 generated by x-ray diffraction and recorded using an electronic detector. The results show an inversely relationship between MFA and age of tree in Acacia mangium wood. MFA decreased from 26.13 degree at age 3 year-old to 0.20 degree at tree of age 15 year-old for the pith region. The most significant drop occurred from 16.14 degree at age 7 year-old to 11.30 degree at age 9 year-old. an inversely relationship between MFA and storage modulus E ' was evidence in Acacia mangium at age 10 year-old. The results showed that about 76.22 % variation of loss modulus E was attributed to the MFA, while about 66.4 % of the variation of glass transition T g was explained by MFA under the same experimental conditions. (author)

  17. Palm Functional Traits: which traits matter and how do we measure them?

    DEFF Research Database (Denmark)

    Eiserhardt, Wolf L.; Balslev, Henrik; Barfod, Anders S.

    role of palms in tropical forest ecosystems. We review data availability for palms for four traits that are commonly used in functional plant ecology: specific leaf area (SLA), wood density, seed size, and maximum height. We suggest that palm functional ecology is impeded by some of the standard...

  18. Wood nitrogen concentrations in tropical trees: phylogenetic patterns and ecological correlates.

    Science.gov (United States)

    Martin, Adam R; Erickson, David L; Kress, W John; Thomas, Sean C

    2014-11-01

    In tropical and temperate trees, wood chemical traits are hypothesized to covary with species' life-history strategy along a 'wood economics spectrum' (WES), but evidence supporting these expected patterns remains scarce. Due to its role in nutrient storage, we hypothesize that wood nitrogen (N) concentration will covary along the WES, being higher in slow-growing species with high wood density (WD), and lower in fast-growing species with low WD. In order to test this hypothesis we quantified wood N concentrations in 59 Panamanian hardwood species, and used this dataset to examine ecological correlates and phylogenetic patterns of wood N. Wood N varied > 14-fold among species between 0.04 and 0.59%; closely related species were more similar in wood N than expected by chance. Wood N was positively correlated with WD, and negatively correlated with log-transformed relative growth rates, although these relationships were relatively weak. We found evidence for co-evolution between wood N and both WD and log-transformed mortality rates. Our study provides evidence that wood N covaries with tree life-history parameters, and that these patterns consistently co-evolve in tropical hardwoods. These results provide some support for the hypothesized WES, and suggest that wood is an increasingly important N pool through tropical forest succession. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  19. The wood, renewable energy

    International Nuclear Information System (INIS)

    Acket, C.

    2006-12-01

    This document evaluates the french forest situation and its future. Indeed, the wood energy constitutes in France the first renewable energy after the hydraulic. It presents the today situation of the french forest providing statistical data, evaluation of the energy estimation, the carbon fixation, the resources, the perspectives wood energy for 2050, the biofuels and an economic analysis. (A.L.B.)

  20. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  1. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Rodney E. Jacobson; Roger M. Rowell

    2005-01-01

    The term “wood-plastic composites” refers to any number of composites that contain wood (of any form) and either thermoset or thermoplastic polymers. Thermosets or thermoset polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins, such as epoxies and phenolics, plastics with which the forest products industry is most familiar (...

  2. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  3. Economy of wood supply

    International Nuclear Information System (INIS)

    Imponen, V.

    1993-01-01

    Research and development of wood fuels production was vigorous in the beginning of the 1980's. Techniques and working methods used in combined harvesting and transportation of energy and merchantable wood were developed in addition to separate energy wood delivery. After a ten year silent period the research on this field was started again. At present the underutilization of forest supplies and the environmental effects of energy production based on fossil fuels caused the rebeginning of the research. One alternative for reduction of the price of wood fuels at the utilization site is the integration of energy and merchantable wood deliveries together. Hence the harvesting and transportation devices can be operated effectively, and the organizational costs are decreased as well. The wood delivery costs consist of the stumpage price, the harvesting and transportation costs, and of general expenses. The stumpage price form the largest cost category (over 50 %) of the industrial merchantable wood delivery, and the harvesting and transportation costs in the case of thinningwood delivery. Forest transportation is the largest part of the delivery costs of logging residues. The general expenses, consisting of the management costs and the interest costs of the capital bound to the storages, form a remarkable cost category in delivery of low-rank wood for energy or conversion purposes. The costs caused by the harvesting of thinningwood, the logging residues, chipping and crushing, the lorry transportation are reviewed in this presentation

  4. How James Wood Works

    Science.gov (United States)

    Goldstein, Evan R., Comp.

    2008-01-01

    Reading through news-media clippings about James Wood, one might reasonably conclude that "pre-eminent critic" is his official job title. In fact, Wood is a staff writer for "The New Yorker" and a professor of the practice of literary criticism at Harvard University. But at a time when there is much hand-wringing about the death of the…

  5. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Pesek, M.; Jarkovsky, J.

    1973-01-01

    Wood is impregnated with a mixture of a vinyl or an allyl monomer (20 - 90 wt. %) and unsaturated polyester resins. The impregnated wood is then exposed to ionizing radiation at doses of 0.1 to 20 Mrad at a temperature of 60 to 180 degC. (B.S.)

  6. Wood would burn

    International Nuclear Information System (INIS)

    Swithenbank, Jim; Chen, Qun; Zhang, Xiaohui; Sharifi, Vida; Pourkashanian, Mohamed

    2011-01-01

    Absract: In view of the world-wide problem of energy sustainability and greenhouse gas production (carbon dioxide), it is timely to review the issues involved in generating heat and power from all fuels and especially new (to the UK) solid fuels, including high moisture fuels such as wood, SRF, oil shale, tar sands and brown coal, which will become major international fuels as oil and gas become depleted. The combustion properties of some of these materials are significantly different from traditional coal, oil and gas fuels, however the technology proposed herein is also applicable to these conventional fuels. This paper presents some innovative combustion system options and the associated technical factors that must be considered for their implementation. For clarity of understanding, the novel concepts will be largely presented in terms of a currently developing solid fuel market; biomass wood chips. One of the most important characteristics of many solid fuels to be used in the future (including oil shale and brown coal) is their high moisture content of up to 60%. This could be removed by utilising low grade waste heat that is widely available in industry to dry the fuel and thus reduce transport costs. Burning such dried wood for power generation also increases the energy available from combustion and thus acts as a thermal transformer by upgrading the low grade heat to heat available at combustion temperatures. The alternative approach presented here is to recover the latent heat by condensing the extrinsic moisture and the water formed during combustion. For atmospheric combustion, the temperature of the condensed combustion products is below the dew point at about 55-65 o C and is only suitable for recovery in an efficient district heating system. However, in order to generate power from the latent heat, the condensation temperature must be increased to the level where the heat can be used in the thermodynamic power cycle. This can be achieved by

  7. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

    Directory of Open Access Journals (Sweden)

    Jean-François Bastin

    Full Text Available Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing. However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass.Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood.Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity

  8. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

    Science.gov (United States)

    Bastin, Jean-François; Fayolle, Adeline; Tarelkin, Yegor; Van den Bulcke, Jan; de Haulleville, Thales; Mortier, Frederic; Beeckman, Hans; Van Acker, Joris; Serckx, Adeline; Bogaert, Jan; De Cannière, Charles

    2015-01-01

    Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass. Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood). Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was

  9. A gauge for the measurement of wood density MGD-05

    International Nuclear Information System (INIS)

    Bartak, J.; Machaj, B.; Urbanski, P.; Pienkos, P.

    2006-01-01

    Wood density is an important parameter determining several properties of wood as: wood quality, mechanical resistance, charcoal production, transport cost, etc. Radiometric methods for the measurement of wood density are based on attenuation of 241 Am gamma radiation, or measurement of backscattered 241 Am radiation. In the paper authors describe the newly constructed computerized gauge designed for the non routine measurements. Up to 1000 measuring results can be stored in the gauge memory and the measuring results can be sent to an external laptop for computations of density contours

  10. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its ...

  11. Tree species traits but not diversity mitigate stem breakage in a subtropical forest following a rare and extreme ice storm.

    Directory of Open Access Journals (Sweden)

    Karin Nadrowski

    Full Text Available Future climates are likely to include extreme events, which in turn have great impacts on ecological systems. In this study, we investigated possible effects that could mitigate stem breakage caused by a rare and extreme ice storm in a Chinese subtropical forest across a gradient of forest diversity. We used Bayesian modeling to correct stem breakage for tree size and variance components analysis to quantify the influence of taxon, leaf and wood functional traits, and stand level properties on the probability of stem breakage. We show that the taxon explained four times more variance in individual stem breakage than did stand level properties; trees with higher specific leaf area (SLA were less susceptible to breakage. However, a large part of the variation at the taxon scale remained unexplained, implying that unmeasured or undefined traits could be used to predict damage caused by ice storms. When aggregated at the plot level, functional diversity and wood density increased after the ice storm. We suggest that for the adaption of forest management to climate change, much can still be learned from looking at functional traits at the taxon level.

  12. The use of wood for wind turbine blade construction

    Science.gov (United States)

    Gougeon, M.; Zuteck, M.

    1979-01-01

    The interrelationships between moisture and wood, conditions for dry rot spore activity, the protection of wood fibers from moisture, wood resin composites, wood laminating, quality control, and the mechanical properties of wood are discussed. The laminated veneer and the bonded sawn stock fabrication techniques, used in the construction of a turbine blade with a monocoque 'D' section forming the leading edge and a built up trailing edge section, are described. A 20 foot root end sample complete with 24 bonded-in studs was successfully subjected to large onetime loads in both the flatwise and edgewise directions, and to fatigue tests. Results indicate that wood is both a viable and advantageous material for use in wind turbine blades. The basic material is reasonably priced, domestically available, ecologically sound, and easily fabricated with low energy consumption.

  13. Wood adhesives : vital for producing most wood products

    Science.gov (United States)

    Charles R. Frihart

    2011-01-01

    A main route for the efficient utilization of wood resources is to reduce wood to small pieces and then bond them together (Frihart and Hunt 2010). Although humankind has been bonding wood since early Egyptian civilizations, the quality and quantity of bonded wood products has increased dramatically over the past 100 years with the development of new adhesives and...

  14. Elucidating How Wood Adhesives Bond to Wood Cell Walls using High-Resolution Solution-State NMR Spectroscopy

    Science.gov (United States)

    Daniel J. Yelle

    2013-01-01

    Some extensively used wood adhesives, such as pMDI (polymeric methylene diphenyl diisocyanate) and PF (phenol formaldehyde) have shown excellent adhesion properties with wood. However, distinguishing whether the strength is due to physical bonds (i.e., van der Waals, London, or hydrogen bond forces) or covalent bonds between the adherend and the adhesive is not fully...

  15. Cord Wood Testing in a Non-Catalytic Wood Stove

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, G. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  16. Psychometric properties of a new short version of the State-Trait Anxiety Inventory (STAI) for the assessment of anxiety in the elderly.

    Science.gov (United States)

    Fernández-Blázquez, M A; Ávila-Villanueva, M; López-Pina, J A; Zea-Sevilla, M A; Frades-Payo, B

    2015-01-01

    Anxiety has negative effects on the cognitive performance and psychosocial adjustment of elderly people. Given the high prevalence of anxiety symptoms in patients suffering from cognitive impairment, it has been suggested that these symptoms may be an early marker of dementia. The State-Trait Anxiety Inventory (STAI) is one of the most widely-used scales for evaluating anxiety in elderly people. However, inasmuch as the STAI may be difficult to apply to older people, having a short form of it would be desirable. The participants comprised 489 community-dwelling individuals aged 68 years and over. All of them were volunteers in a longitudinal study for early detection of Alzheimer' Disease (Proyecto Vallecas). The full sample was divided in two homogeneous subgroups: Group A, used to reduce the number of items and response options, and Group B, the group used to determine the psychometric properties of the new short form (STAIr). A dichotomous Rasch model was used to obtain the STAIr. No statistically significant differences for STAIr scores were found with respect to sociodemographic variables. Psychometric properties and normative data were obtained for the new short version. The STAIr is composed of 13 items and data fits the model well. Since it is short and easy to apply to elderly people, STAIr will be very useful in clinical and research settings. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.

  17. CHARACTERISTICS AND PHENOTYPICAL VARIABILITY OF TOMATO INITIAL BREEDING MATERIAL ACCORDING TO THE MAIN ECONOMICALLY VALUABLE TRAITS AND PROPERTIES

    Directory of Open Access Journals (Sweden)

    R. K. Rechets

    2016-01-01

    Full Text Available The market of Moldova has a large assortment of seed of foreign selection, such as large-fruited tomatoes, cherry and cocktail tomato. Therefore, it is necessary to launch the breeding program for hybrid development of local origin tomato typed, such as ‘Cherry’ and ‘Cocktail’ with a different form, mass and fruit color. Initially, 15 parental forms of tomato were studied for the main economically valuable traits in the open field condition. Phenotypic variation in tomato varieties and breeding accession was identified depending on the terms of cultivation. Such varieties and lines of tomato as ‘Trapesa’, ‘Rosovaya Kapelka’, ‘Seniyorita’, ‘Ocharovaniye’, ‘L. 46/06’, ‘L. 49/09’, ‘L 295/09,’ ‘L. 336/11’, ‘L. 354/11’, ‘L. 357/11’, ‘L. 388/09 (nor’, ‘L.498 (released by TARI, ‘Tigris’, ‘Vishnya Zheltaya’ (released by OOO ‘Gavrish’, ‘Denezhnoye Derevo’ (national breeding program were used as the initial breeding material. Totally, 15 breeding accessions were used for the study, where all of them differed in the type of bush (determinate and indeterminate; a vegetation period (ultra-early, early, middle, late; a form (roundish, oval; a fruit color (red, pink, black, orange, tiger and with a NOR gene; a fruit weight (from 10 g and above; a structure of brush (dense, loose. Lines and varieties of tomato of different terms of ripening characterized by the shortened internode, high fruit setting on the bush, high content of biologically active substances, and complex resistance to diseases were used to breed tomato hybrids of ‘cherry’ and ‘cocktail’ types with different fruit form and color.

  18. Wood-plastic composites using thermomechanical pulp made from oxalic acid-pretreated red pine chips

    Science.gov (United States)

    J.E. Winandy; N.M. Stark; E. Horn

    2008-01-01

    The characteristics and properties of wood fiber is one of many factors of critical importance to the performance of wood-plastic composites. In commercial thermo-mechanical pulping (TMP) of wood chips to produce fibers, high temperatures (>100°C) are used to separate the fibers during TMP refining. These mechanical pressures and temperatures are usually modulated...

  19. Effect of processing method on surface and weathering characteristics of wood-flour/HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2004-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  20. Effect of processing method on accelerated weathering of wood-flour/HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana; Craig M. Clemons

    2003-01-01

    Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50...

  1. Changes in wood flour/HDPE composites after accelerated weathering with and without water spray

    Science.gov (United States)

    Nicole M. Stark

    2005-01-01

    Wood-plastic lumber is promoted as a low-maintenance high-durability product. After weathering, however, wood-plasticcomposites (WPCs) often fide and lose mechanical properties. In the first part ofthis study, 50%wood-flour-filled high-density polyethylene (HDPE) composite samples were injection molded or extruded. Composites were exposed to two accelerated weathering...

  2. Chromatographic analysis of the reaction of soy flour with formaldehyde and phenol for wood adhesives

    Science.gov (United States)

    Linda F. Lorenz; Charles R. Frihart; James M. Wescott

    2007-01-01

    The desire to make more biobased and lower-cost bonded wood products has led to an interest in replacing some phenol and formaldehyde in wood adhesives with soybean flour. Improved knowledge of the soy protein properties is needed to relate resin chemistry to resin performance before and after wood bonding. To expose the soy protein’s functional groups, it...

  3. Path analysis of the energy density of wood in eucalyptus clones.

    Science.gov (United States)

    Couto, A M; Teodoro, P E; Trugilho, P F

    2017-03-16

    Path analysis has been used for establishing selection criteria in genetic breeding programs for several crops. However, it has not been used in eucalyptus breeding programs yet. In the present study, we aimed to identify the wood technology traits that could be used as the criteria for direct and indirect selection of eucalyptus genotypes with high energy density of wood. Twenty-four eucalyptus clones were evaluated in a completely randomized design with five replications. The following traits were assessed: basic wood density, total extractives, lignin content, ash content, nitrogen content, carbon content, hydrogen content, sulfur content, oxygen content, higher calorific power, holocellulose, and energy density. After verifying the variability of all evaluated traits among the clones, a two-dimensional correlation network was used to determine the phenotypic patterns among them. The obtained coefficient of determination (0.94) presented a higher magnitude in relation to the effect of the residual variable, and it served as an excellent model for explaining the genetic effects related to the variations observed in the energy density of wood in all eucalyptus clones. However, for future studies, we recommend evaluating other traits, especially the morphological traits, because of the greater ease in their measurement. Selecting clones with high basic density is the most promising strategy for eucalyptus breeding programs that aim to increase the energy density of wood because of its high heritability and magnitude of the cause-and-effect relationship with this trait.

  4. Chapter 6: Wood energy and competing wood product markers

    Science.gov (United States)

    Kenneth E. Skog; Robert C. Abt; Karen Abt

    2014-01-01

    Understanding the effect of expanding wood energy markets is important to all wood-dependent industries and to policymakers debating the implementation of public programs to support the expansion of wood energy generation. A key factor in determining the feasibility of wood energy projects (e.g. wood boiler or pellet plant) is the long-term (i.e. 20-30year) supply...

  5. Wood and Wood-Based Materials as Sensors—A Review of the Piezoelectric Effect in Wood

    Science.gov (United States)

    Robert J. Ross; Jiangming Kan; Xiping Wang; Julie Blankenburg; Janet I. Stockhausen; Roy F. Pellerin

    2012-01-01

    A variety of techniques have been investigated for use in assessing the physical and mechanical properties of wood products and structures. Ultrasound, transverse vibration, and stress-wave based methods are all techniques that have shown promise for many nondestructive evaluation applications. These techniques and others rely on the use of measurement systems to...

  6. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  7. Wood wastes: Uses

    International Nuclear Information System (INIS)

    Cipro, A.

    1993-01-01

    The 1,500 industrial firms manufacturing furniture in the Italian Province of Treviso can generate up to 190,000 tonnes of wood wastes annually. In line with the energy conservation-environmental protection measures contained in Italian Law No. 475/88, this paper indicates convenient uses for these wood wastes - as a raw material for fibreboards or as a fuel to be used in the furniture manufacturing plants themselves and in kilns producing lime. Reference is made to the wood wastes gasification/power generation system being developed by ENEA (the Italian Agency for New Technology, Energy and the Environment)

  8. Integrated dataset of anatomical, morphological, and architectural traits for plant species in Madagascar

    Directory of Open Access Journals (Sweden)

    Amira Azizan

    2017-12-01

    Full Text Available In this work, we present a dataset, which provides information on the structural diversity of some endemic tropical species in Madagascar. The data were from CIRAD xylotheque (since 1937, and were also collected during various fieldworks (since 1964. The field notes and photographs were provided by French botanists; particularly by Francis Hallé. The dataset covers 250 plant species with anatomical, morphological, and architectural traits indexed from digitized wood slides and fieldwork documents. The digitized wood slides were constituted by the transverse, tangential, and radial sections with three optical magnifications. The main specific anatomical traits can be found within the digitized area. Information on morphological and architectural traits were indexed from digitized field drawings including notes and photographs. The data are hosted in the website ArchiWood (http://archiwood.cirad.fr. Keywords: Morpho-architectural traits, Plant architecture, Wood anatomy, Madagascar

  9. Impregnating Systems for Producing Wood-Plastic Composite Materials and Resinified Woods by Radiochemical Means

    International Nuclear Information System (INIS)

    Laizier, J.; Laroche, R.; Marchand, J.

    1969-01-01

    The effect of the nature of the components in the impregnation mixture on the characteristics of wood-plastic combinations has been studied in the case of beech by applying a wide variety of compositions. In particular, the effect of water (in the impregnator, and in the form of moisture in the wood) on the characteristics of the products obtained has been determined. It has been shown that, in place of the conventional method for preparing resinified woods (using a ternary monomer-solvent-water mixture), it is possible to use a method involving comonomers, which obviate the need to dry the wood after treatment. The evaluation of the results obtained is based on the value of the impregnation rate and on the modifications in microscopic structure; these emphasize the differences between the types of filler and enable comparisons to be drawn with the dimensional stabilities observed. Measurements of variations in dimensions and the recurrence of moisture have made it possible to establish a classification based on the types of monomer used and the operating conditions. It is shown that a whole range of products is obtained, the properties of which differ widely and are comparatively easily adaptable to the purpose specified. These properties illustrate clearly the differences and characteristics of resinified woods as opposed to conventional wood-plastic materials. (author) [fr

  10. Anisotropy of Wood in the Microwave Region

    Science.gov (United States)

    Ziherl, Sasa; Bajc, Jurij; Urankar, Bernarda; Cepic, Mojca

    2010-01-01

    Wood is transparent for microwaves and due to its anisotropic structure has anisotropic dielectric properties. A laboratory experiment that allows for the qualitative demonstration and quantitative measurements of linear dichroism and birefringence in the microwave region is presented. As the proposed experiments are based on the anisotropy (of…

  11. Photostabilization of wood flour filled HDPE composites

    Science.gov (United States)

    Nicole M. Stark; Laurent M. Matuana

    2002-01-01

    Wood/plastic composites are increasingly examined for non-structural building applications. As outdoor applications become more widespread, durability becomes an issue. Ultraviolet exposure can lead to photodegradation, resulting in a change in appearance and/or mechanical properties. Photodegradation can be slowed through the addition of photostabilizers. This study...

  12. Factors influencing laser cutting of wood

    Science.gov (United States)

    V.G. Barnekov; C.W. McMillin; H.A. Huber

    1986-01-01

    Factors influencing the ability of lasers to cut wood may be generally classified into these three areas: 1) characteristics of the laser beam; 2) equipment and processing variables; and 3) properties of the workpiece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist...

  13. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2016-01-01

    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  14. Characterization of wood-based molding bonded with citric acid

    OpenAIRE

    Umemura, Kenji; Ueda, Tomohide; Kawai, Shuichi

    2012-01-01

    The wood-based moldings were fabricated by using only citric acid as an adhesive. The mechanical properties, water resistances, thermal properties and chemical structure were investigated. Wood powder obtained from Acacia mangium was mixed with citric acid under certain weight ratios (0-40 wt%), and each powder mixture was molded using two types of metal molds at 200 °C and 4MPa for 10 min. The modulus of rupture (MOR) and the modulus of elasticity (MOE) values of the wood-based molding conta...

  15. Evaluation of adhesive penetration of wood fibre by nanoindentation and microscopy

    Science.gov (United States)

    Christopher G. Hunt; Joseph E. Jakes; Warren Grigsby

    2010-01-01

    Adhesives used in wood products sometimes infiltrate, or diffuse into the solid material of, wood cell walls, potentially modifying their properties. These changes in cell wall properties are likely to impact the performance of adhesive bonds. While adhesive infiltration has been observed by multiple methods, the effect on cell wall properties is not well understood....

  16. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  17. Wood fuel and the environment

    International Nuclear Information System (INIS)

    Foster, C.A.

    1992-01-01

    The purpose of this paper is to try and demonstrate the role that the use of Wood as a Fuel can play in our environment. The term ''Wood Fuel'', for the purposes of these proceedings, refers to the use of wood obtained from the forest or the farm. It does not refer to waste wood from for example buildings. The role of wood fuel in the environment can be assessed at many different levels. In this paper three different scales of ''Environment'' and the role of wood fuel in each, will be considered. These three scales are namely the global environment, the local environment, and the National (community) environment. (Author)

  18. How to decrease the hydrophilicity of wood flour to process efficient composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Pouzet, M.; Gautier, D.; Charlet, K. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France); Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Dubois, M., E-mail: Marc.DUBOIS@univ-bpclermont.fr [Clermont Université, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, BP 10448, Clermont-Ferrand 63000 (France); CNRS, UMR 6296, Institut de Chimie de Clermont-Ferrand, Aubière 63177 (France); Béakou, A. [Institut Pascal, UMR 6602 UBP/CNRS/IFMA, BP 265, Aubière 63175 (France)

    2015-10-30

    Graphical abstract: Evolution of the contact angle of a water drop on sample (θ{sub c}) according to the fluorinated material. - Highlights: • Fluorination was applied to wood flour. • Covalent attachment of fluorine atoms onto wood surface decreases its hydrophilicity. • Fluorinated wood flour was added into composites with polyester. • Fluorination enhances the interface between wood flour and polymer matrix. - Abstract: Dynamic fluorination and static fluorination were applied to wood flour to decrease its hydrophilic character, aiming at processing wood-polymer composites with good properties. Fourier-Transform infrared spectra and {sup 19}F solid state NMR (Nuclear Magnetic Resonance) results proved the successful covalent bonding of fluorine atoms onto the wood's chemical structure. It revealed that static fluorination brings about a less damaged and less hydrophilic fluorinated wood than with dynamic fluorination. Composites manufactured from this fluorinated wood presented a hydrophobic character directly related to the hydrophicity of these wood reinforcements. A composite made with fluorinated wood and polyester exhibited a higher hydrophobicity than the neat polyester and than the composite made with non-treated wood. Moreover, the further fluorination of a composite made of fluorinated wood led to a contact angle comparable to that of some metals (steel, gold) due to the etching of the composite surface during fluorination.

  19. Energy from wood - an overview

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2000-01-01

    The present publication is the introduction to a series of papers on fundamentals and applications of wood energy. It summarizes figures and data of the actual situation of fuel wood utilization in Switzerland and its potential for the future. Further, the advantages of bio-energy are discussed and the possibilities of funding for bio-energy in Switzerland are described. Wood contributes with 2.5% to the total energy demand in Switzerland nowadays. However, the utilization of wood energy can be more than doubled, which is one of the targets of the Swiss energy policy. The supply chains for the different types of fuel wood are described and specifications and prices of log wood, forestry wood chips and wood residues are presented. The main applications of wood energy are residential heating with manually operated wood boilers and stoves, on the one hand, and heat production with automatic wood furnaces in industry and communities, on the other hand. Automatic furnaces have been promoted in the past ten years and hence they contribute nowadays with more than 50% to the energy supply from wood with a further growing share. As an assistance for further information, a list of institutions and addresses in the field of wood energy in Switzerland is given in the paper. (author)

  20. Design considerations for the commercial production of wood acrylics

    International Nuclear Information System (INIS)

    Witt, A.E.; Bosco, L.R.

    1978-01-01

    The major application of wood acrylics is for flooring, more specifically in high traffic area. The most important property is its abrasion resistance. As for the decisions in facility design, the following considerations must be made: irradiation or heat-catalyst to polymerize, machine irradiation or isotope irradiation, and wet or dry irradiation. Then, processing considerations are made on wood type, monomer selection, dye selection, fire retardant, dose conditions and crosslinker usage. In ''PermaGrain'' production, for example, the facility has the yearly production capacity of over 4,000,000 kilograms of wood acrylic. The starting wood form is small slats or fingers. After pressure cycle, the impregnant wet wood is lowered into an irradiation pool and the product canister passes around a cobalt 60 source. After irradiation, the product is taken out of the pool and allowed to cool. Then, final sizing and finishing are carried out. (Mori, K.)

  1. Modification of polypropylene with radiation-treated wood fiber

    International Nuclear Information System (INIS)

    Czvikovszky, T.; Tapolcai, I.

    1983-01-01

    The dispersed wood material is used not only as filler for thermosetting polymers but also as a new type of fibrous additive for thermoplastics e.g. polypropylene. Benefit of this additive (filler or reinforcement) is determined by the coupling between the wood and the synthetic resin. Fibrous, dispersed wood material was preirradiated in air, treated with vinyl monomer containing polyester resin and then mixed in polypropylene. Processability of such thermoplastic blends as well as reactivity of the mixed components were followed by measuring energy, absorbed during the kneading of the melt. The vinylmonomer vinylmonomer - polyester additive, activated at higher temperature by the radiation-formed peroxy groups on the wood fiber, results in good processability of the thermoplastic blend, and gives interesting mechanical properties. Calandering, extrusion, pressmoulding and mechanical testing demonstrated good workability and practical value of the polypropylene composite material containing radiation-treated wood fiber. (author)

  2. Propriedades físico-mecânicas da madeira de canafístula aos 10 anos de idade Physical and mechanical properties of 10 years old wood trees of canafístula

    Directory of Open Access Journals (Sweden)

    Magnos Alan Vivian

    2010-05-01

    Full Text Available A presente pesquisa objetivou caracterizar as propriedades físico-mecânicas da madeira de canafístula (Peltophorum dubium (Spreng. Taub. proveniente de árvores com 10 anos, por meio da determinação da massa específica básica, da retratibilidade, do módulo de elasticidade e do módulo de ruptura em flexão estática, do módulo de elasticidade em compressão perpendicular, da resistência máxima à compressão paralela à grã, da dureza de Janka, da resistência máxima ao cisalhamento e da resistência ao choque. A determinação da massa específica básica e da retratibilidade seguiu as normas COPANT 30:1-004 (1971 e 30:1-005 (1971, respectivamente, e os ensaios mecânicos seguiram as normas ASTM D 143-94 (2000 e NF B 51-009 (1942. A massa específica básica e o coeficiente de anisotropia encontrado para a espécie permitiram classificar sua madeira como leve e medianamente estável, respectivamente; já os valores médios das propriedades mecânicas encontradas definem a madeira como de resistência fraca a média. As características tecnológicas determinadas indicam que sua madeira, quando proveniente de plantios jovens, deve ser utilizada com cautela em situações que exijam elevada estabilidade dimensional e resistência mecânica, sendo, portanto, aconselhável seu corte em idades mais avançadas.This research aimed to characterize the physic-mechanical properties of the canafístula wood (Peltophorum dubium (Spreng. Taub. from 10 years' old trees. There was determined the specific gravity, shrinkage, modulus of elasticity and modulus of rupture in static bending, modulus of elasticity in compression perpendicular to the grain, compression strength parallel to the grain, hardness, shear and impact resistance. Specific gravity and shrinkage determination were conducted according to COPANT 30:1:004 (1971 and 30:1-005 (1971, respectively, and the mechanical tests followed ASTM D 143-94 (2000 and NF B51-009 (1942. The specific

  3. Wood for fuel

    Energy Technology Data Exchange (ETDEWEB)

    Beaton, D

    1986-01-01

    Growing wood for energy could contribute three million tonnes of coal equivalent per year by the end of the century. Research programmes in the UK involved with energy forestry are reported. Three systems of wood energy, modified conventional forestry, single stem timber cropping and short rotation coppicing are being investigated. The short rotation coppicing requires inputs similar to those of agricultural crops and the machinery geared towards agricultural operations is compatible with it. Single stem forestry has a medium rotation period of 20 years. The production of coppice wood fuels is discussed in further detail for different parts of the UK with recommendations for species selection and adaption of existing farming practices. A coppice willow harvester has been developed for harvesting during November - February. Weed control and fertilizer application are also briefly mentioned.

  4. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  5. Optically Transparent Wood from a Nanoporous Cellulosic Template: Combining Functional and Structural Performance.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Yu, Shun; Yan, Min; Berglund, Lars

    2016-04-11

    Optically transparent wood (TW) with transmittance as high as 85% and haze of 71% was obtained using a delignified nanoporous wood template. The template was prepared by removing the light-absorbing lignin component, creating nanoporosity in the wood cell wall. Transparent wood was prepared by successful impregnation of lumen and the nanoscale cellulose fiber network in the cell wall with refractive-index-matched prepolymerized methyl methacrylate (MMA). During the process, the hierarchical wood structure was preserved. Optical properties of TW are tunable by changing the cellulose volume fraction. The synergy between wood and PMMA was observed for mechanical properties. Lightweight and strong transparent wood is a potential candidate for lightweight low-cost, light-transmitting buildings and transparent solar cell windows.

  6. The structure and properties of ZrN-Ni-Co-coatings on the edges steel knives of wood-cutting tools

    International Nuclear Information System (INIS)

    Chaevskij, V.V.; Grishkevich, A.A.; Zhilinskij, V.V.; Kuleshov, A.K.

    2015-01-01

    Modes were selected and formed electroplated Ni-Co-coatings, ion-plasma Zr N-coatings as well as combined Zr N-Ni-Co-coating on the edges steel (type R6M5) knives of wood-cutting milling tools. Formed electroplated Ni-Co-layers are not mixed with the steel substrate and the Zr N-coating. Microhardness of combined Zr N-Ni-Co-coatings is to 1,2-1,5 times more than microhardness of steel base and bare steel. When cutting laminated chipboard by steel knives of milling tool with a Ni-Co- and Zr N-Ni-Co-coatings under laboratory conditions, abrasive surface wear type of edges knives is observed. Calculating bulk wear of edges knives with Zr N-Ni-Co-coatings showed reduction of more than 3 times value in comparison with knives with Ni-Co-coatings. Pilot testing of tool modified with combined Zr N-Ni-Co-coatings at OJSC 'Minskdrev' when cutting pine confirmed relevance of the tests carried out, as well as showed an increase in durability period of cutters to 30% compared with bare tool. (authors)

  7. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S

    2005-07-15

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  8. Methane from wood

    International Nuclear Information System (INIS)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S.

    2005-07-01

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  9. Mapping wood density globally using remote sensing and climatological data

    Science.gov (United States)

    Moreno, A.; Camps-Valls, G.; Carvalhais, N.; Kattge, J.; Robinson, N.; Reichstein, M.; Allred, B. W.; Running, S. W.

    2017-12-01

    Wood density (WD) is defined as the oven-dry mass divided by fresh volume, varies between individuals, and describes the carbon investment per unit volume of stem. WD has been proven to be a key functional trait in carbon cycle research and correlates with numerous morphological, mechanical, physiological, and ecological properties. In spite of the utility and importance of this trait, there is a lack of an operational framework to spatialize plant WD measurements at a global scale. In this work, we present a consistent modular processing chain to derive global maps (500 m) of WD using modern machine learning techniques along with optical remote sensing data (MODIS/Landsat) and climate data using the Google Earth Engine platform. The developed approach uses a hierarchical Bayesian approach to fill in gaps in the plant measured WD data set to maximize its global representativeness. WD plant species are then aggregated to Plant Functional Types (PFT). The spatial abundance of PFT at 500 m spatial resolution (MODIS) is calculated using a high resolution (30 m) PFT map developed using Landsat data. Based on these PFT abundances, representative WD values are estimated for each MODIS pixel with nearby measured data. Finally, random forests are used to globally estimate WD from these MODIS pixels using remote sensing and climate. The validation and assessment of the applied methods indicate that the model explains more than 72% of the spatial variance of the calculated community aggregated WD estimates with virtually unbiased estimates and low RMSE (<15%). The maps thus offer new opportunities to study and analyze the global patterns of variation of WD at an unprecedented spatial coverage and spatial resolution.

  10. Wood energy-commercial applications

    Science.gov (United States)

    Kennel, R. P.

    1978-01-01

    Wood energy is being widely investigated in many areas of the country because of the many obvious benefits of wood fuel such as the low price per million Btus relative to coal, oil, and gas; the wide availability of noncommercial wood and the proven ability to harvest it; established technology which is reliable and free of pollution; renewable resources; better conservation for harvested land; and the potential for jobs creation. The Southeastern United States has a specific leadership role in wood energy based on its established forest products industry experience and the potential application of wood energy to other industries and institutions. Significant questions about the widespread usage of wood energy are being answered in demonstrations around the country as well as the Southeast in areas of wood storage and bulk handling; high capitalization costs for harvesting and combustion equipment; long term supply and demand contracts; and the economic feasibility of wood energy outside the forest products industry.

  11. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  12. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  13. Low-NO{sub x}, wood chip combustion

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Oravainen, H.; Haemaelaeinen, J.; Paakkinen, K. [VTT Energy, Jyvaeskylae (Finland)

    1997-10-01

    The regulations for nitrogen oxide emissions vary in different countries, but the general trend in the future will probably be that the emissions limits will be lowered also for wood combustion plants, which are small or medium size units. Thus, the development of wood chip burning furnaces (grate furnaces, fluidized bed combustors, stoker furnaces) with lower nitrogen oxide emissions, is important. The wood used in the combustor, its particle size, moisture and fuel properties (nitrogen content) affect the nitrogen emissions. The nitrogen oxide release is also much affected by the design and operation of the combustor (air staging, fuel air preheat, flue gas circulation, air to fuel mass ratio). The fate of nitrogen compounds originally in the virgin wood depends much on the design of the combustor system and by proper planning it is possible to reduce the emission of nitrogen oxides. Basic knowledge of the release of nitrogen compounds from single wood particles is attained. The release of gaseous nitrogen compounds from wood particles during pyrolysis and combustion is studied experimentally and by modelling. Nitrogen release is studied experimentally by two ways, by analysing the gas and by quenching the particle and analysing the char residue. Formation of nitrogen oxide emissions in a fuel bed is studied by modelling and by combustion experiments with a pot furnace. This research gives general information of nitrogen oxide formation in wood bunting especially in fixed beds. The development of a horizontal stoker burner for wood chips with low emissions is the practical aim of the research. (orig.)

  14. In situ polymerization of polyaniline in wood veneers.

    Science.gov (United States)

    Trey, Stacy; Jafarzadeh, Shadi; Johansson, Mats

    2012-03-01

    The present study describes the possibility to polymerize aniline within wood veneers to obtain a semi-conducting material with solid wood acting as the base template. It was determined that it is possible to synthesize the intrinsically conductive polymer (ICP) polyaniline in situ within the wood structure of Southern yellow pine veneers, combining the strength of the natural wood structure with the conductivity of the impregnated polymer. It was found that polyaniline is uniformly dispersed within the wood structure by light microscopy and FT-IR imaging. A weight percent gain in the range of 3-12 wt % was obtained with a preferential formation in the wood structure and cell wall, rather than in the lumen. The modified wood was found to be less hydrophilic with the addition of phosphate doped polyaniline as observed by equilibrium water swelling studies. While wood itself is insulating, the modified veneers had conductivities of 1 × 10(-4) to 1 × 10(-9) S cm(-1), demonstrating the ability to tune the conductivity and allowing for materials with a wide range of applications, from anti-static to charge-dispersing materials. Furthermore, the modified veneers had lower total and peak heat releases, as determined by cone calorimetry, because of the char properties of the ICP. This is of interest if these materials are to be used in building and furniture applications where flame retardance is of importance. © 2012 American Chemical Society

  15. Power generation from waste wood

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, H

    1980-04-18

    Since the energy crisis, power generation from waste wood has become increasingly important. The most profitable way to use waste wood in woodworking plants with an annual production of 100 to 150,000 m/sup 3/ solid measure of wood chips and bark is by combustion and thermal energy recovery. In plants with an annual production of 10,000 m/sup 3/ solid measure of wood chips and bark, electric power generation is a suitable application.

  16. Structure and function of wood

    Science.gov (United States)

    Alex Wiedenhoeft

    2010-01-01

    Wood is a complex biological structure, a composite of many chemistries and cell types acting together to serve the needs of a living plant. Attempting to understand wood in the context of wood technology, we have often overlooked the key and basic fact that wood evolved over the course of millions of years to serve three main functions in plants― conduction of water...

  17. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    The intent of this article is to demonstrate how wood waste called sawdust or wood flour can be transformed by plastic moulding machine into items of economic value. Wood flour is wood reduced to very fine particle form. It can be waste product from saw mills, wood working plants or produced from selected dry wood by ...

  18. Studies of non-contact methods for roughness measurements on wood surfaces

    International Nuclear Information System (INIS)

    Lundberg, I.A.S.; Porankiewicz, B.

    1995-01-01

    The quality of wood surfaces after different kinds of machining processes is a property of great importance for the wood processing industries. Present work is a study, whose objective was to evaluate different non-contact methods, for measurement of the quality of the wood surfaces by correlating them with stylus tracing. A number of Scots Pine samples were prepared by different kinds of wood machining processing. Surface roughness measurements were performed, utilizing two optical noncontact methods. The results indicate that the laser scan method can measure surface roughness on sawn wood with a sufficient degree of accuracy. (author) [de

  19. The Personality Inventory for DSM-5 Short Form (PID-5-SF): psychometric properties and association with big five traits and pathological beliefs in a Norwegian population

    OpenAIRE

    Thimm, Jens C.; Jordan, Stian; Bach, Bo

    2016-01-01

    Background With the publication of the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), an alternative model for personality disorders based on personality dysfunction and pathological personality traits was introduced. The Personality Inventory for DSM-5 (PID-5) is a 220-item self-report inventory designed to assess the personality traits of this model. Recently, a short 100-item version of the PID-5 (PID-5-SF) has been developed. The aim of this study was ...

  20. Status of wood energy applications

    International Nuclear Information System (INIS)

    Zerbe, J.I.

    1991-01-01

    In this address, the potential of wood and wood residues to supply future energy needs is examined. In addition, the possible environmental impact of the use of wood fuels on global climate change is discussed. Technologies for the development of new fuels are described

  1. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  2. Macrophotographic wood atlas of Annonaceae.

    NARCIS (Netherlands)

    Koek-Noorman, J.; Westra, L.I.T.

    2012-01-01

    In this article, a general description of the microscopic wood anatomy of Annonaceae is given. We provide a description of the wood anatomical features of the family and of all subfamilies and tribes, all from material in the Utrecht Wood collection. Hand-lens images can be an important help in

  3. Wood construction and magnetic characteristics of impregnated type magnetic wood

    International Nuclear Information System (INIS)

    Oka, Hideo; Hojo, Atsushi; Seki, Kyoushiro; Takashiba, Toshio

    2002-01-01

    The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability

  4. Preliminary studies of Brazilian wood using different radioisotopic sources

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Gilberto; Silva, Leonardo Gondim de Andrade e, E-mail: gcarval@ipen.br, E-mail: ftgasilva@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Due to availability and particular features, wood was one of the first materials used by mankind with a wide variety of applications. It can be used as raw material for paper and cellulose manufacturing; in industries such as chemical, naval, furniture, sports goods, toys, and musical instrument; in building construction and in the distribution of electric energy. Wood has been widely researched; therefore, wood researchers know that several aspects such as temperature, latitude, longitude, altitude, sunlight, soil, and rainfall index interfere with the growth of trees. This behavior explains why average physical-chemical properties are important when wood is studied. The majority of researchers consider density to be the most important wood property because of its straight relationship with the physical and mechanical properties of wood. There are three types of wood density: basic, apparent and green. The apparent density was used here at 12% of moisture content. In this study, four different types of wood were used: 'freijo', 'jequetiba', 'muiracatiara' and 'ipe'. For wood density determination by non-conventional method, Am-241, Ba-133 and Cs-137 radioisotopic sources; a NaI scintillation detector and a counter were used. The results demonstrated this technique to be quick and accurate. By considering the nuclear parameters obtained as half value layers and linear absorption coefficients, Cs-137 radioisotopic source demonstrated to be the best option to be used for inspection of the physical integrity of electric wooden poles and live trees for future works. (author)

  5. Wood specific gravity and anatomy of branches and roots in 113 Amazonian rainforest tree species across environmental gradients.

    Science.gov (United States)

    Fortunel, Claire; Ruelle, Julien; Beauchêne, Jacques; Fine, Paul V A; Baraloto, Christopher

    2014-04-01

    Wood specific gravity (WSG) is a strong predictor of tree performance across environmental gradients. Yet it remains unclear how anatomical elements linked to different wood functions contribute to variation in WSG in branches and roots across tropical forests. We examined WSG and wood anatomy in white sand, clay terra firme and seasonally flooded forests in French Guiana, spanning broad environmental gradients found throughout Amazonia. We measured 15 traits relating to branches and small woody roots in 113 species representing the 15 most abundant species in each habitat and representative species from seven monophyletic lineages occurring in all habitats. Fiber traits appear to be major determinants of WSG, independent of vessel traits, in branches and roots. Fiber traits and branch and root WSG increased from seasonally flooded species to clay terra firme species and lastly to white sand species. Branch and root wood traits were strongly phylogenetically constrained. Lineages differed in wood design, but exhibited similar variation in wood structure across habitats. We conclude that tropical trees can invest differently in support and transport to respond to environmental conditions. Wind disturbance and drought stress represent significant filters driving tree distribution of Amazonian forests; hence we suggest that biophysical explanations should receive more attention. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  6. Potential of Reinforced Indonesian Glulam Beams Using Grade I (Bengkirai, Grade II (Kamper, Grade III (Nyatoh Woods for Use in Structural Wood Design

    Directory of Open Access Journals (Sweden)

    Saptahari Sugiri

    2016-05-01

    Full Text Available Wood is a natural resource that is renewable and available in various species in tropical countries. Its abundancy in nature makes it easy to obtain, thus making it a nature friendly material for use in construction. Indonesia is the most important source of tropical wood in the world after Brazil, making the use of wood for structural elements very desirable. It is estimated that 4000 different varieties of wood exist in Indonesia. This estimate is based on the herbarium species collected by the Forestry Research Institute, currently counting nearly 4000 types of trees with a diameter of more than 40 cm. In the Indonesian wood structure code, the strength of woods is divided into 3 grades (grade I, II and III. This paper presents an evaluation of the mechanical properties of glulam wood sourced from native Indonesian timber: Bengkirai wood (grade I, Kamper wood (grade II, and Nyatoh wood (grade III, thus proving the potential for Indonesian wood as industrial structural elements in wooden constructions.

  7. Grant Wood: "American Gothic."

    Science.gov (United States)

    Fitzgerald, Diane M.

    1988-01-01

    Presents a lesson plan which exposes students in grades 10-12 to the visual symbols and historical references contained in Grant Wood's "American Gothic." Includes background information on the artist and the painting, instructional strategies, a studio activity, and evaluation criteria. (GEA)

  8. Dark Dark Wood

    DEFF Research Database (Denmark)

    2017-01-01

    2017 student Bachelor film. Synopsis: Young princess Maria has had about enough of her royal life – it’s all lesson, responsibilities and duties on top of each other, every hour of every day. Overwhelmed Maria is swept away on an adventure into the monster-filled dark, dark woods. During 2017...

  9. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O; Ribeiro, R [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1998-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  10. Sweetgum - an American wood

    Science.gov (United States)

    C. B. Briscoe

    1973-01-01

    Sweetgum grows throughout most of the eastern United States and sporadically throughout Mexico and Central America. The wood is moderately heavy, even-textured, and it machines moderately well. It is used for a variety of purposes, with furniture, plywood, containers, and pulp absorbing the most volume. Growth is good, but supplies are slowly diminishing because the...

  11. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O.; Ribeiro, R. [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1997-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  12. Handling wood shavings

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-18

    Details of bulk handling equipment suitable for collection and compressing wood waste from commercial joinery works are discussed. The Redler Bin Discharger ensures free flow of chips from storage silo discharge prior to compression into briquettes for use as fuel or processing into chipboard.

  13. Wood-Polymer composites obtained by gamma irradiation

    International Nuclear Information System (INIS)

    Gago, J.; Lopez, A.; Rodriguez, J.; Santiago, J.; Acevedo, M.

    2007-01-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained

  14. Wood-Polymer composites obtained by gamma irradiation

    Science.gov (United States)

    Gago, J.; López, A.; Santiago, J.; Acevedo, M.; Rodríguez, J.

    2007-10-01

    In this work we impregnate three Peruvian woods (Calycophy spruceanum Be, Aniba amazonica Meiz and Hura crepitans L) with styrene-polyester resin and methyl methacrylate. The polymerization of the system was promoted by gamma radiation and the experimental optimal condition was obtained with styrene-polyester 1:1 and 15 kGy. The obtained composites show reduced water absorption and better mechanical properties compared to the original wood. The structure of the wood-polymer composites was studied by light microscopy. Water absorption and hardness were also obtained.

  15. Study of UV curing in the wood industry

    International Nuclear Information System (INIS)

    Haider Osama Al-Mahdi

    1999-01-01

    Although mass production is the primary demand, the wood finishing must nevertheless conform to certain minimal standards. The surface should be protected and sealed against heat, dirt and abrasion, and insulated from the ingress and evaporation of moisture which would cause dimensional changes in the timber. The finish should be clear (unclouded) and smooth to enhance the natural beauty of the figure and the grain. The finish should also maintain its appearance, and adhesion, as well as protection given to the wood. The film should not seriously be degrading during the lifetime of the article. All the standards mentioned above are available in the 100% solid acrylic UV finishing system. A thorough study of the timber wood anatomy and of the physical and chemical properties of polymerized film is essential in order to match these properties with the wood substrate

  16. Substitution potentials of recycled HDPE and wood particles from post-consumer packaging waste in Wood-Plastic Composites.

    Science.gov (United States)

    Sommerhuber, Philipp F; Welling, Johannes; Krause, Andreas

    2015-12-01

    The market share of Wood-Plastic Composites (WPC) is small but expected to grow sharply in Europe. This raises some concerns about suitable wood particles needed in the wood-based panels industry in Europe. Concerns are stimulated by the competition between the promotion of wooden products through the European Bioeconomy Strategy and wood as an energy carrier through the Renewable Energy Directive. Cascade use of resources and valorisation of waste are potential strategies to overcome resource scarcity. Under experimental design conditions, WPC made from post-consumer recycled wood and plastic (HDPE) were compared to WPC made from virgin resources. Wood content in the polymer matrix was raised in two steps from 0% to 30% and 60%. Mechanical and physical properties and colour differences were characterized. The feasibility of using cascaded resources for WPC is discussed. Results indicate the technical and economic feasibility of using recycled HDPE from packaging waste for WPC. Based on technical properties, 30% recycled wood content for WPC is feasible, but economic and political barriers of efficient cascading of biomass need to be overcome. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Wood formation from the base to the crown in Pinus radiata: gradients of tracheid wall thickness, wood density, radial growth rate and gene expression

    Science.gov (United States)

    Sheree Cato; Lisa McMillan; Lloyd Donaldson; Thomas Richardson; Craig Echt; Richard Gardner

    2006-01-01

    Wood formation was investigated at five heights along the bole for two unrelated trees of Pinus radiataBoth trees showed clear gradients in wood properties from the base to the crown. Cambial cells at the base of the tree were dividing 3.3-fold slower than those at the crown, while the average thickness of cell walls in wood was highest at the base....

  18. X-ray phase-contrast micro-tomography and image analysis of wood microstructure

    International Nuclear Information System (INIS)

    Mayo, Sheridan; Evans, Robert; Chen, Fiona; Lagerstrom, Ryan

    2009-01-01

    A number of commercially important properties of wood depend on details of the wood micro- and nano- structure. CSIRO Forest Biosciences have developed SilviScan, an analytical instrument which uses a number of high-speed techniques for analyzing these properties. X-ray micro-tomographic analysis of wood samples provides detailed 3D reconstructions of the wood microstructure which can be used to validate results from SilviScan measurements. A series of wood samples was analysed using laboratory-based phase-contrast x-ray micro-tomography. Image analysis techniques were applied to the 3D data sets to extract significant features and statistical properties of the specimens. These data provide a means of verification of results from the more rapid SilviScan techniques, and will clarify the results of micro-diffraction studies of wood microfibrils.

  19. Nondestructive chemical imaging of wood at the micro-scale: advanced technology to complement macro-scale evaluations

    Science.gov (United States)

    Barbara L. Illman; Julia Sedlmair; Miriam Unger; Carol Hirschmugl

    2013-01-01

    Chemical images help understanding of wood properties, durability, and cell wall deconstruction for conversion of lignocellulose to biofuels, nanocellulose and other value added chemicals in forest biorefineries. We describe here a new method for nondestructive chemical imaging of wood and wood-based materials at the micro-scale to complement macro-scale methods based...

  20. Wood pellets in a power plant - mixed combustion of coal and wood pellets

    International Nuclear Information System (INIS)

    Nupponen, M.

    2001-01-01

    The author reviews in his presentation the development of Turku Energia, the organization of the company, the key figures of the company in 2000, as well as the purchase of energy in 2000. He also presents the purchase of basic heat load, the energy production plants of the company, the sales of heat in 2000, the emissions of the plants, and the fuel consumption of the plants in 2000. The operating experiences of the plants are also presented. The experiences gained in Turku Energia on mixed combustion of coal and wood pellets show that the mixing ratios, used at the plants, have no effect on the burning properties of the boiler, and the use of wood pellets with coal reduce the SO 2 and NO x emissions slightly. Simultaneously the CO 2 share of the wood pellets is removed from the emissions calculations. Several positive effects were observed, including the disappearance of the coal smell of the bunker, positive publicity of the utilization of wood pellets, and the subsidies for utilization of indigenous fuels in power generation. The problems seen include the tendency of wood pellets to arc the silos, especially when the pellets include high quantities of dust, and the loading of the trucks and the pneumatic unloading of the trucks break the pellets. Additionally the wood pellets bounce on the conveyor so they drop easily from the conveyor, the screw conveyors designed for conveying grain are too weak and they get stuck easily, and static electricity is easily generated in the plastic pipe used as the discharge pipe for wood pellet (sparkling tendency). This disadvantage has been overcome by using metal net and grounding