WorldWideScience

Sample records for wood variability effects

  1. Temporal dynamic of wood formation in Pinus cembra along the alpine treeline ecotone and the effect of climate variables.

    Science.gov (United States)

    Gruber, Andreas; Baumgartner, Daniel; Zimmermann, Jolanda; Oberhuber, Walter

    2009-06-01

    We determined the temporal dynamic of cambial activity and xylem development of stone pine (Pinus cembra L.) throughout the treeline ecotone. Repeated micro-sampling of the developing tree ring was carried out during the growing seasons 2006 and 2007 at the timberline (1950 m a.s.l.), treeline (2110 m a.s.l.) and within the krummholz belt (2180 m a.s.l.) and the influence of climate variables on intra-annual wood formation was determined.At the beginning of both growing seasons, highest numbers of cambial and enlarging cells were observed at the treeline. Soil temperatures at time of initiation of cambial activity were c. 1.5 °C higher at treeline (open canopy) compared to timberline (closed canopy), suggesting that a threshold root-zone temperature is involved in triggering onset of above ground stem growth.The rate of xylem cell production determined in two weekly intervals during June through August 2006-2007 was significantly correlated with air temperature (temperature sums expressed as degree-days and mean daily maximum temperature) at the timberline only. Lack of significant relationships between tracheid production and temperature variables at the treeline and within the krummholz belt support past dendroclimatological studies that more extreme environmental conditions (e.g., wind exposure, frost desiccation, late frost) increasingly control tree growth above timberline.Results of this study revealed that spatial and temporal (i.e. year-to-year) variability in timing and dynamic of wood formation of Pinus cembra is strongly influenced by local site factors within the treeline ecotone and the dynamics of seasonal temperature variation, respectively.

  2. Physiological Effects of Touching Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7  ±  1.6 years participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV was used as an indicator of autonomic nervous activity. The high-frequency (HF component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1 decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2 increased ln(HF-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.

  3. 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.

  4. Factors effecting paint performance on wood siding

    Science.gov (United States)

    Christopher G. Hunt; R. Sam Williams; Mark Knaebe; Peter Sotos; Steven Lacher

    2009-01-01

    Several different studies are compared to assess the effectiveness of commercial water repellent preservatives (WRP’s) in the late 1990’s on vertical and horizontal siding. Besides WRP, variables included wood species, exposure location (Wisconsin or Mississippi), and solid color stain vs. primer + paint. Data on substrate checking and paint flaking are presented....

  5. Physiological Effects of Touching Coated Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study examined the physiological effects of touching wood with various coating with the palm of the hand on brain activity and autonomic nervous activity. Participants were 18 female university students (mean age, 21.7 ± 1.6 years. As an indicator of brain activity, oxyhemoglobin concentrations were measured in the left and right prefrontal cortices using near-infrared time-resolved spectroscopy. Heart rate variability (HRV and heart rate were used as indicators of autonomic nervous activity. The high-frequency (HF component of HRV, which reflects parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflects sympathetic nervous activity, were measured. Plates of uncoated, oil-finished, vitreous-finished, urethane-finished, and mirror-finished white oak wood were used as tactile stimuli. After sitting at rest with their eyes closed for 60 s, participants touched the stimuli with their palm for 90 s each. The results indicated that tactile stimulation with uncoated wood calmed prefrontal cortex activity (vs. urethane finish and mirror finish, increased parasympathetic nervous activity (vs. vitreous finish, urethane finish, and mirror finish, and decreased heart rate (vs. mirror finish, demonstrating a physiological relaxation effect. Further, tactile stimulation with oil- and vitreous-finished wood calmed left prefrontal cortex activity and decreased heart rate relative to mirror-finished wood.

  6. Physiological Effects of Touching Coated Wood.

    Science.gov (United States)

    Ikei, Harumi; Song, Chorong; Miyazaki, Yoshifumi

    2017-07-13

    This study examined the physiological effects of touching wood with various coating with the palm of the hand on brain activity and autonomic nervous activity. Participants were 18 female university students (mean age, 21.7 ± 1.6 years). As an indicator of brain activity, oxyhemoglobin concentrations were measured in the left and right prefrontal cortices using near-infrared time-resolved spectroscopy. Heart rate variability (HRV) and heart rate were used as indicators of autonomic nervous activity. The high-frequency (HF) component of HRV, which reflects parasympathetic nervous activity, and the low-frequency (LF)/HF ratio, which reflects sympathetic nervous activity, were measured. Plates of uncoated, oil-finished, vitreous-finished, urethane-finished, and mirror-finished white oak wood were used as tactile stimuli. After sitting at rest with their eyes closed for 60 s, participants touched the stimuli with their palm for 90 s each. The results indicated that tactile stimulation with uncoated wood calmed prefrontal cortex activity (vs. urethane finish and mirror finish), increased parasympathetic nervous activity (vs. vitreous finish, urethane finish, and mirror finish), and decreased heart rate (vs. mirror finish), demonstrating a physiological relaxation effect. Further, tactile stimulation with oil- and vitreous-finished wood calmed left prefrontal cortex activity and decreased heart rate relative to mirror-finished wood.

  7. 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

  8. 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

  9. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    Leavitt, S.W.; Long, A.

    1986-01-01

    This study documents variation of stable-carbon isotope ratios ( 13 C/ 12 C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  10. Effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures

    Science.gov (United States)

    Andy W.C. Lee; Zhongli Hong; Douglas R. Phillips; Chung-Yun Hse

    1987-01-01

    This study investigated the effect of cement/wood ratios and wood storage conditions on hydration temperature, hydration time, and compressive strength of wood-cement mixtures made from six wood species: southern pine, white oak, southern red oak, yellow-poplar, sweetgum, and hickory. Cement/wood ratios varied from 13/1 to 4/1. Wood storage conditions consisted of air-...

  11. Irradiation effects in wood and cellulose

    International Nuclear Information System (INIS)

    McLaren, K.G.

    1976-01-01

    For cellulosic materials the predominant effect of high energy radiation is depolymerisation and degradation by chain scission, although there is some evidence that crosslinking or cellulose stabilisation can occur under certain conditions. When the cellulose is in the form of a natural product such as wood, where it is intimately associated with other polysaccharides, lignins, resins and gums, the effects of radiation can be significantly modified. Examination of cellulose produced by chemical pulping treatment of wood which had been previously given small doses of radiation, showed significant differences in the extent of cellulose depolymerisation with different wood species. The relevance of this work to the paper pulp industry will also be discussed. (author)

  12. 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...

  13. Wood phenology, not carbon input, controls the interannual variability of wood growth in a temperate oak forest.

    Science.gov (United States)

    Delpierre, Nicolas; Berveiller, Daniel; Granda, Elena; Dufrêne, Eric

    2016-04-01

    Although the analysis of flux data has increased our understanding of the interannual variability of carbon inputs into forest ecosystems, we still know little about the determinants of wood growth. Here, we aimed to identify which drivers control the interannual variability of wood growth in a mesic temperate deciduous forest. We analysed a 9-yr time series of carbon fluxes and aboveground wood growth (AWG), reconstructed at a weekly time-scale through the combination of dendrometer and wood density data. Carbon inputs and AWG anomalies appeared to be uncorrelated from the seasonal to interannual scales. More than 90% of the interannual variability of AWG was explained by a combination of the growth intensity during a first 'critical period' of the wood growing season, occurring close to the seasonal maximum, and the timing of the first summer growth halt. Both atmospheric and soil water stress exerted a strong control on the interannual variability of AWG at the study site, despite its mesic conditions, whilst not affecting carbon inputs. Carbon sink activity, not carbon inputs, determined the interannual variations in wood growth at the study site. Our results provide a functional understanding of the dependence of radial growth on precipitation observed in dendrological studies. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  14. EFFECTS OF BURN RATE, WOOD SPECIES, MOISTURE CONTENT AND WEIGHT OF WOOD LOADED ON WOODSTOVE EMISSIONS

    Science.gov (United States)

    The report gives results of tests of four woodstove operating parameters (burn rate, wood moisture, wood load, and wood species) at two levels each using a half factorial experimental test design to determine statistically significant effects on the emission components CO, CO2, p...

  15. Climate effects of wood used for bioenergy

    Energy Technology Data Exchange (ETDEWEB)

    Ros, Jan P.M.; Van Minnen, Jelle G. [Netherlands Environmental Assessment Agency PBL, Bilthoven (Netherlands); Arets, Eric J.M.M. [Alterra, Wageningen University WUR, Wageningen (Netherlands)

    2013-08-15

    Wood growth and natural decay both take time, and this is an important aspect of sustainability assessments of wood used for energy. Wood taken from forests is a carbon-neutral energy source in the long term, but there are many examples of potential sources of wood used for bioenergy for which net emission reductions are not achieved in 10 to 40 years - the time frame for most climate policy mitigation targets. This is caused by two factors. The first factor relates to the fact that the carbon cycles of wood have a long time span. After final felling, CO2 fixation rates are initially relatively low, but increase again as forests regrow. This regrowth takes many years, sometimes more than a century. Wood residues can either be used or left in the forest. By using them, the emissions from the otherwise decaying residues (taking 2 to 30 years) would be avoided. The second factor concerns the fact that, if the wood is used for bioenergy, then fossil energy emissions are being avoided. However, the direct emission levels from bioenergy are higher than those related to the fossil energy it replaces. These additional emissions also have to be compensated. The carbon debt caused by both factors has to be paid back first, before actual emission reductions can be realised. For wood residues (from harvesting or thinning) that are used to replace coal or oil products, these payback times are relatively short, of the order of 5 to 25 years, mainly depending on location and type of residue (longer if they replace gas). This is also the case when using wood from salvage logging. In most cases, when using wood from final felling directly for energy production, payback times could be many decades to more than a century, with substantial increases in net CO2 emissions, in the meantime. This is especially the case for many forests in Europe, because they are currently an effective carbon sink. Additional felling reduces average growth rates in these forests and thus the sequestration

  16. RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2016-04-01

    Full Text Available ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

  17. Variability in evaluating environmental impacts of treated wood.

    Science.gov (United States)

    Stan T. Lebow; Paul Cooper; Patricia K. Lebow

    2004-01-01

    Preservative-treated wood contains components that may be toxic to non-target organisms if released into the environment in sufficient quantities. Numerous studies have been conducted to determine the rate of preservative release from treated wood and/or the extent of their subsequent accumulation in the environment. These studies have produced a wide range of results...

  18. Duration of load effects of solid wood

    DEFF Research Database (Denmark)

    Svensson, Staffan

    Test methods for studying the effect of long-term loading on the load carrying capacity of structural wood are discussed. The impact of sampling procedures on test results is investigated and is exemplified. It is concluded from this investigation that the sampling method has a significant impact...

  19. 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...

  20. A Tool for Estimating Variability in Wood Preservative Treatment Retention

    Science.gov (United States)

    Patricia K. Lebow; Adam M. Taylor; Timothy M. Young

    2015-01-01

    Composite sampling is standard practice for evaluation of preservative retention levels in preservative-treated wood. Current protocols provide an average retention value but no estimate of uncertainty. Here we describe a statistical method for calculating uncertainty estimates using the standard sampling regime with minimal additional chemical analysis. This tool can...

  1. Anatomical variability of the trunk wood and root tissues of ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the anatomical structure of the trunk wood and the roots of A. nitida and R. racemosa, two mangrove trees from Gabon. The anatomical differences between the trunks and the roots were used to understand their bio-remediating differences through heavy metals. It was found that the ...

  2. 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.

  3. Health effects assessment of exposure to particles from wood smoke

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Elsa; Dybdahl, M [Technical Univ. of Denmark, National Food Institute, Dept. of Toxicology and Risk Assessment, Soeborg (Denmark); Larsen, Poul Bo [Danish Environmental Protection Agency, Copenhagen (Denmark)

    2008-07-01

    The number of residential wood burning devices has increased in Denmark during the latest years and it has been estimated that there in 2005 were about 551,000 wood stoves and about 48,000 wood boilers in Denmark. This has resulted in an increased exposure of the general Danish population to pollutants associated with residential wood smoke. New Danish monitoring results on particulate matter (PM) in ambient air have shown elevated PM levels in areas with many wood stoves, particularly during wintertime when wood burning is common. Due to the size distribution of wood smoke particles essentially all will be contained in the PM{sub 2.5} fraction. It has been estimated that about 17,665 tonnes PM{sub 2.5} per year (2005) in Denmark come from residential wood combustion. Therefore, there is an increasing concern that adverse human health effects might be associated with the increased exposure to residential wood smoke. This project has been set up in order to review the scientific literature concerning adverse health effects of pollutants associated with residential wood smoke with the main focus on particulate matter and to quantify and evaluate, if possible, the impact on human health of the increased exposure to particles in residential wood smoke. (au)

  4. Effects of phosphoramides on wood dimensional stability

    Science.gov (United States)

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

    2000-01-01

    To evaluate the dimensional stability of phosphoramide-reacted wood, wood was reacted with a mixture which was derived from compounding phosphorus pentoxide and each of 12 amines including alkyl, halophenyl, and phenyl amines in N,N-dimethylformamide. Dimensional stability of such reacted wood was analyzed by antishrink efficiency (ASE) using the water-soak method....

  5. Temperature effects on wood anatomy, wood density, photosynthesis and biomass partitioning of Eucalyptus grandis seedlings.

    Science.gov (United States)

    Thomas, D S; Montagu, K D; Conroy, J P

    2007-02-01

    Wood density, a gross measure of wood mass relative to wood volume, is important in our understanding of stem volume growth, carbon sequestration and leaf water supply. Disproportionate changes in the ratio of wood mass to volume may occur at the level of the whole stem or the individual cell. In general, there is a positive relationship between temperature and wood density of eucalypts, although this relationship has broken down in recent years with wood density decreasing as global temperatures have risen. To determine the anatomical causes of the effects of temperature on wood density, Eucalyptus grandis W. Hill ex Maiden seedlings were grown in controlled-environment cabinets at constant temperatures from 10 to 35 degrees C. The 20% increase in wood density of E. grandis seedlings grown at the higher temperatures was variously related to a 40% reduction in lumen area of xylem vessels, a 10% reduction in the lumen area of fiber cells and a 10% increase in fiber cell wall thickness. The changes in cell wall characteristics could be considered analogous to changes in carbon supply. Lumen area of fiber cells declined because of reduced fiber cell expansion and increased fiber cell wall thickening. Fiber cell wall thickness was positively related to canopy CO2 assimilation rate (Ac), which increased 26-fold because of a 24-fold increase in leaf area and a doubling in leaf CO2 assimilation rate from minima at 10 and 35 degrees C to maxima at 25 and 30 degrees C. Increased Ac increased seedling volume, biomass and wood density; but increased wood density was also related to a shift in partitioning of seedling biomass from roots to stems as temperature increased.

  6. Variability in energy and carbon dioxide balances of wood and concrete building materials

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Leif; Sathre, Roger [Ecotechnology, Mid Sweden University, SE-831 25 OEstersund (Sweden)

    2006-07-15

    A variety of factors affect the energy and CO{sub 2} balances of building materials over their lifecycle. Previous studies have shown that the use of wood for construction generally results in lower energy use and CO{sub 2} emission than does the use of concrete. To determine the uncertainties of this generality, we studied the changes in energy and CO{sub 2} balances caused by variation of key parameters in the manufacture and use of the materials comprising a wood- and a concrete-framed building. Parameters considered were clinker production efficiency, blending of cement, crushing of aggregate, recycling of steel, lumber drying efficiency, material transportation distance, carbon intensity of fossil fuel, recovery of logging, sawmill, construction and demolition residues for biofuel, and growth and exploitation of surplus forest not needed for wood material production. We found the materials of the wood-framed building had lower energy and CO{sub 2} balances than those of the concrete-framed building in all cases but one. Recovery of demolition and wood processing residues for use in place of fossil fuels contributed most significantly to the lower energy and CO{sub 2} balances of wood-framed building materials. We conclude that the use of wood building material instead of concrete, coupled with greater integration of wood by-products into energy systems, would be an effective means of reducing fossil fuel use and net CO{sub 2} emission to the atmosphere. (author)

  7. Variability in energy and carbon dioxide balances of wood and concrete building materials

    International Nuclear Information System (INIS)

    Gustavsson, Leif; Sathre, Roger

    2006-01-01

    A variety of factors affect the energy and CO 2 balances of building materials over their lifecycle. Previous studies have shown that the use of wood for construction generally results in lower energy use and CO 2 emission than does the use of concrete. To determine the uncertainties of this generality, we studied the changes in energy and CO 2 balances caused by variation of key parameters in the manufacture and use of the materials comprising a wood- and a concrete-framed building. Parameters considered were clinker production efficiency, blending of cement, crushing of aggregate, recycling of steel, lumber drying efficiency, material transportation distance, carbon intensity of fossil fuel, recovery of logging, sawmill, construction and demolition residues for biofuel, and growth and exploitation of surplus forest not needed for wood material production. We found the materials of the wood-framed building had lower energy and CO 2 balances than those of the concrete-framed building in all cases but one. Recovery of demolition and wood processing residues for use in place of fossil fuels contributed most significantly to the lower energy and CO 2 balances of wood-framed building materials. We conclude that the use of wood building material instead of concrete, coupled with greater integration of wood by-products into energy systems, would be an effective means of reducing fossil fuel use and net CO 2 emission to the atmosphere. (author)

  8. 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...

  9. Anatomical variability of the trunk wood and root tissues of ...

    African Journals Online (AJOL)

    Any interspecies variability was found between their trunk vessels diameter. However, a significant ... are discharged in the sea, releasing like this toxic organic ...... Water. Discharge on nutrient contamination of mangrove soils and plants.

  10. The variability of wood density and compression strength of Norway spruce

    Czech Academy of Sciences Publication Activity Database

    Horáček, Petr; Fajstavr, Marek; Stojanović, Marko

    2017-01-01

    Roč. 10, 1-2 (2017), s. 17-26 ISSN 1803-2451 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:86652079 Keywords : Norway spruce * wood density * compression strength * variability Subject RIV: GK - Forestry OBOR OECD: Forestry

  11. Leaf phenology and wood formation of white cedar trees (Melia azedarach L. and their responses to climate variability

    Directory of Open Access Journals (Sweden)

    Kritsadapan Palakit

    2018-02-01

    Full Text Available This research aimed to investigate the response of leaf phenologies and wood increments of Melia azedarach L. on climate variability. The visual estimation indicated the leaf flushing in January-July, the leaf maturation in January-November, and the leaf abscission in May-June and October-December. Monthly wood investigations of the inside bark diameters (IBD indicated an annual-ring formation with the wood increment in February-November and the dormancy in December-January. The outside bark diameter (OBD exhibited growth variations with phases of slow increment in September-October, shrinkage in December-February, and fast increment in March-August. The relationship among monthly climates, leaf phenologies and wood increments, indicated the significant correlations of the soil moisture and the abundances of mature dark green leaves on the IBD, while the OBD was fluctuated due to the direct effect of the IBD and the indirect effect of the soil moisture and mature dark green leaf abundances.

  12. Effect of residual wood on a morphology of mountain stream Cremos; Vplyv zvyskov dreva na morfologiu horskeho toku Cremos

    Energy Technology Data Exchange (ETDEWEB)

    Kralcakova, M [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra fyzickej geografie a geoekologie, 84215 Bratislava (Slovakia)

    2012-04-25

    Several research papers are dedicated to the effect of wood in the river bed of the flow. It is done on the basis of empirical and theoretical knowledge. Globally, field research is practised on the application of knowledge on the impact of scrap wood mainly in the upstream mountain streams. The reason is that the flows founded in these altitudes are more likely inclined to supply wood because of forest cover area and the resulting consequences for a river-basin. In my research I mainly dealt with the impact of individual residues in stream sections of Cremos. During studying wood residues a determination of its variability was important. On the basis of this variability is important to define a classification of individual pieces of wood within the river-basin. (author)

  13. Health effects assessment of exposure to particles from wood smoke

    DEFF Research Database (Denmark)

    Nielsen, Elsa

    2007-01-01

    distribution of wood smoke particles, essentially all will be contained in the PM2.5 fraction. In Denmark, recent results indicate that about 10,000 tonnes PM2.5 per year, about half of the total particle emission in Denmark, come from residential wood combustion. Based on a few measurement campaigns conducted...... in Denmark in selected residential areas with different kinds of heating, the annual average PM2.5 exposure from wood smoke can be estimated at 0.4–2 mg/m3 as a preliminary estimate for the whole Danish population. Epidemiological studies evaluating adverse health effects from ambient air pollution...

  14. Wood pellets. The cost-effective fuel

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    The article is based on an interview with Juhani Hakkarainen of Vapo Oy. Wood pellets are used in Finland primarily to heat buildings such as schools and offices and in the home. They are equally suitable for use in larger installations such as district heating plants and power stations. According to him wood pellets are suitable for use in coal-fired units generating heat, power, and steam. Price-wise, wood pellets are a particularly competitive alternative for small coal-fired plants away from the coast. Price is not the only factor on their side, however. Wood pellets also offer a good environmental profile, as they burn cleanly and generate virtually no dust, an important plus in urban locations. The fact that pellets are a domestically produced fuel is an added benefit, as their price does not fluctuate in the same way that the prices of electricity, oil, coal, and natural gas do. The price of pellets is largely based on direct raw material and labour costs, which are much less subject to ups and downs

  15. Granulated wood ash to forest soil - Ecological effects

    International Nuclear Information System (INIS)

    Rosen, K.; Eriksson, H.; Clarholm, M.; Lundkvist, H.; Rudebeck, A.

    1993-01-01

    This report describes research concerning ecological effects of wood ash recycling to forest soils. The main part of the minerals in the wood fuels are retained in the ashes after combustion. By returning the ashes back to the cleared forest areas, the mineral losses can be reduced. Adding ashes and limestone is a method to vitalize acidified forest soils and restore the production capacity. 48 refs, 26 figs, 8 tabs

  16. Ecotoxicity and fungal deterioration of recycled polypropylene/wood composites: effect of wood content and coupling.

    Science.gov (United States)

    Sudár, András; López, María J; Keledi, Gergely; Vargas-García, M Carmen; Suárez-Estrella, Francisca; Moreno, Joaquín; Burgstaller, Christoph; Pukánszky, Béla

    2013-09-01

    Recycled polypropylene (rPP) was recovered from an industrial shredder and composites were prepared with a relatively wide range of wood content and with two coupling agents, a maleated PP (MAPP) and a maleated ethylene-propylene-diene elastomer (MAEPDM). The mechanical properties of the composites showed that the coupling agents change structure only slightly, but interfacial adhesion quite drastically. The durability of the materials was determined by exposing them to a range of fungi and, ecotoxicity was studied on the aquatic organism Vibrio fischeri. The composites generally exhibit low acute toxicity, with values below the levels considered to have direct ecotoxic effect on aquatic ecosystems (deterioration proved that wood facilitates fungal colonization. Fungi caused slight mass loss (below 3%) but it was not correlated with substantial deterioration in material properties. MAPP seems to be beneficial in the retention of mechanical properties during fungal attack. rPP/wood composites can be considered non-ecotoxic and quite durable, but the influence of wood content on resistance to fungal attack must be taken into account for materials intended for applications requiring long-term outdoor exposure. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Effects of wood dust:Inflammation, Genotoxicity and Cancer

    DEFF Research Database (Denmark)

    Lange, Jette Bornholdt

    cell line A549 measuring inflammatory and DNA damaging effects. The second part consists of a molecular analysis of the K-ras gene for mutations in the hotspots codons in human sinonasal cancers. Design, calibration and validation of the assays were performed. Cancer at the sinonasal cavities is rare...... with incidence rates between of 0.3 to 1.4 per 100,000 for men and 0.1 to 0.8 per 100,000 for women in Europe, depending on country. However, cancer at this site is associated with occupational exposures including wood dust. Especially the adenocarcinoma subtype is strongly associated with exposure to wood dust...... and their potential to cause DNA damage. Contrary to our hypothesis, we showed that pure wood dust is able to cause primary DNA damage, independent of inflammation as well as hardwoods had no higher inflammatory or genotoxic potential than softwoods. To investigate the molecular mechanisms behind the wood dust...

  18. A Review of Wood Plastic Composites effect on the Environment

    Directory of Open Access Journals (Sweden)

    Ahmed Taifor Azeez

    2017-05-01

    Full Text Available Wood Plastic Composites (WPCs are environmentally friend materials with a wide range of applications in the field of constructions, comprising high mechanical and physical properties with low cost raw materials as plastic wastes and different carpentry process wood reminder. The effects of wood, plastic waste and additives on various properties of the material such as mechanical (modulus of elasticity and modulus of rupture, physical (moisture absorption and fire retardancy have been investigated in order to push the output functions of the products to the limits of work conditions requirements. This study, overviews the importance of Wood Plastic Composites in conserving the environment by depletion post consume plastics from landfills, and the impact of these composites in developing the economic via opening new flourished markets for modern products. Both the ecological and economical requirements oblige the Iraqi government to replace the negatively healthy effects formaldehyde wood composites (medium density fiberboard MDF which are widely consumed in Iraqi markets with Wood Plastic Composites. a long-term strategy plan in which the researchers and the capitals meet under supervision of the government is very necessary and recommended in this paper to establish and develop WPCs industry in Iraq.

  19. Effects of wood preservative leachates from docks

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, P.H.; Van Dolah, R.F.; Bobo, M.Y.; Mathews, T.D. [South Carolina Marine Resources Research Inst., Charleston, SC (United States)

    1994-12-31

    Recent evidence indicates that the wood preservative commonly used in dock pilings (chromated copper arsenate or CCA) is highly toxic to several estuarine organisms in laboratory experiments. Increasing demand for residential docks prompted a field study intended to complement these earlier laboratory investigations. Objectives of the study were to: (1) examine concentrations of Cu, Cr, and As in sediments and oysters from intertidal locations in several creeks with and without high densities of docks; (2) examine the bioaccumulation of wood preservative leachates by laboratory-reared oysters transferred to field sites near and distant from newly constructed docks; and (3) investigate the acute toxicity of wood preservative leachates for several species of estuarine fishes and invertebrates exposed to these compounds in the field. Preliminary results indicate that sediment concentrations of all three metals were well below ER-L levels reported by Long and Morgan at all but one dock site. In an ancillary study, 24h LC{sub 50} bioassays were performed using rotifers (Brachionus plicatilis) which were exposed to pore water from sediments in creeks with and without docks. Toxicities of bulk sediments from the same sites were examined using Microtox which measures decreases in bioluminescence of marine bacteria (Photobacterium phosphoreum) as a function of sediment concentration. Neither the rotifer nor the Microtox bioassays showed any significant differences in toxicity between creeks with and without docks.

  20. The Effect of Ultrasound Pretreatment on Poplar Wood Dimensional Stability

    Directory of Open Access Journals (Sweden)

    Shu Qiu

    2016-08-01

    Full Text Available Dimensional stability is a key property of wood that significantly affects its applications. The effect of an ultrasound pretreatment on poplar wood (Populous tomentosa dimensional stability was examined. During the pretreatments, wood samples were immersed in distilled water and treated ultrasonically under three different powers and frequencies. The samples were then analyzed by Fourier transform infrared spectroscopy (FTIR and X-ray diffraction (XRD. The chemical transformation of the cell-wall material was studied and then associated with the change of water absorption and the swelling coefficient. The results showed that the water absorption decreased after the ultrasonic pretreatment. The axial and radial swelling coefficients of the pretreated samples decreased, while the tangential swelling coefficients increased. The volumetric swelling coefficient of pretreated specimens fluctuated near 4.48% (the volumetric swelling coefficient of untreated wood. Ultrasonic pretreatment increased the number of hydrophilic groups, such as the hydroxyl, acetyl, and uronic ester groups. Meanwhile, the pretreatment also increased the degree of crystallinity and reduced the available polar groups. These two factors together caused the change of the moisture absorption and the swelling coefficient of the pretreated wood. These conclusions suggest that the ultrasonic pretreatment is a promising method for further chemical modification of wood.

  1. Effects of swelling forces on the durability of wood adhesive bonds

    Science.gov (United States)

    Blake M. Hofferber; Edward Kolodka; Rishawn Brandon; Robert J. Moon; Charles R. Frihart

    2006-01-01

    The purpose of this study was to investigate the role of wood swelling on performance of wood-adhesive bonds (resorcinol formaldehyde, epoxy, emulsion polymerisocyanate), for untreated and acetylated wood. Effects of these treatments on measured strain anisotropy and swelling stress were measured and then related to compressive shear strength and percentage wood...

  2. 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.

  3. Comparative study on liquefaction of creosote and chromated copper arsenate (CCA)-treated wood and untreated southern pine wood: effects of acid catalyst content, liquefaction time, temperature, and phenol to wood ratio

    Science.gov (United States)

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

    2009-01-01

    Creosote- and chromated copper arsenate (CCA)-treated wood waste and untreated southern pine wood were liquefied with phenol and sulfuric acid. The effects of sulfuric acid content, liquefaction time, liquefaction temperature, and phenol to wood ratio on liquefaction rate (i.e., wood residue content) were investigated and analyzed by analysis of variance (...

  4. Effects of Small-Scale Dead Wood Additions on Beetles in Southeastern U.S. Pine Forests

    Directory of Open Access Journals (Sweden)

    Chris E. Carlton

    2012-08-01

    Full Text Available Pitfall traps were used to sample beetles (Coleoptera in plots with or without inputs of dead loblolly pine (Pinus taeda L. wood at four locations (Louisiana, Mississippi, North Carolina and Texas on the coastal plain of the southeastern United States. The plots were established in 1998 and sampling took place in 1998, 1999, and 2002 (only 1998 for North Carolina. Overall, beetles were more species rich, abundant and diverse in dead wood addition plots than in reference plots. While these differences were greatest in 1998 and lessened thereafter, they were not found to be significant in 1998 due largely to interactions between location and treatment. Specifically, the results from North Carolina were inconsistent with those from the other three locations. When these data were excluded from the analyses, the differences in overall beetle richness for 1998 became statistically significant. Beetle diversity was significantly higher in the dead wood plots in 1999 but by 2002 there were no differences between dead wood added and control plots. The positive influence of dead wood additions on the beetle community can be largely attributed to the saproxylic fauna (species dependent on dead wood, which, when analyzed separately, were significantly more species rich and diverse in dead wood plots in 1998 and 1999. Ground beetles (Carabidae and other species, by contrast, were not significantly affected. These results suggest manipulations of dead wood in pine forests have variable effects on beetles according to life history characteristics.

  5. Effects of application methods and species of wood on color ...

    African Journals Online (AJOL)

    In this study, the color effects of wood materials to coloring with different application methods (brush, roller sponge and spray gun) and waterborne varnishes were investigated according to ASTM-D 2244. For this purpose, the experimental samples of Scots pine (Pinus silvestris L.), oriental beech (Fagus orientalis L.) and ...

  6. Effect of different Rates of Wood Ash on Exchangeable Aluminum ...

    African Journals Online (AJOL)

    Response of soybean grown on acidic soil to wood ash applied at 0, 2, 4, 6, and 8 t ha-1 was studied in two field experiments in 2003 and 2004 at Umudike in the rainforest zone of Southeast Nigeria. Treatments were fitted in a randomized complete block design (RCBD) replicated three times. Effect of treatments on some ...

  7. Interacting effects of insects and flooding on wood decomposition.

    Directory of Open Access Journals (Sweden)

    Michael D Ulyshen

    Full Text Available Saproxylic arthropods are thought to play an important role in wood decomposition but very few efforts have been made to quantify their contributions to the process and the factors controlling their activities are not well understood. In the current study, mesh exclusion bags were used to quantify how arthropods affect loblolly pine (Pinus taeda L. decomposition rates in both seasonally flooded and unflooded forests over a 31-month period in the southeastern United States. Wood specific gravity (based on initial wood volume was significantly lower in bolts placed in unflooded forests and for those unprotected from insects. Approximately 20.5% and 13.7% of specific gravity loss after 31 months was attributable to insect activity in flooded and unflooded forests, respectively. Importantly, minimal between-treatment differences in water content and the results from a novel test carried out separately suggest the mesh bags had no significant impact on wood mass loss beyond the exclusion of insects. Subterranean termites (Isoptera: Rhinotermitidae: Reticulitermes spp. were 5-6 times more active below-ground in unflooded forests compared to flooded forests based on wooden monitoring stakes. They were also slightly more active above-ground in unflooded forests but these differences were not statistically significant. Similarly, seasonal flooding had no detectable effect on above-ground beetle (Coleoptera richness or abundance. Although seasonal flooding strongly reduced Reticulitermes activity below-ground, it can be concluded from an insignificant interaction between forest type and exclusion treatment that reduced above-ground decomposition rates in seasonally flooded forests were due largely to suppressed microbial activity at those locations. The findings from this study indicate that southeastern U.S. arthropod communities accelerate above-ground wood decomposition significantly and to a similar extent in both flooded and unflooded forests

  8. Health effects on nearby residents of a wood treatment plant

    International Nuclear Information System (INIS)

    Dahlgren, James; Warshaw, Raphael; Thornton, John; Anderson-Mahoney, P.M.; Takhar, Harpreet

    2003-01-01

    Objectives: The aim of the study was to evaluate the health status of nearby residents of a wood treatment plant who had sustained prolonged low-level environmental exposure to wood processing waste chemicals. Methods: A population of 1269 exposed residents who were plaintiffs or potential plaintiffs in a lawsuit against the wood treatment plant were evaluated by questionnaire for a health history and symptoms. A representative sample of 214 exposed subjects was included in the analysis. One hundred thirty-nine controls were selected from 479 unexposed volunteers and matched to the exposed subjects as closely as possible by gender and age. Subjects and controls completed additional questionnaires and were evaluated by a physician for medical history and physical examination, blood and urine testing, neurophysiological and neuropsychological studies, and respiratory testing. Environmental sampling for wood processing waste chemicals was carried out on soil and drainage ditch sediment in the exposed neighborhood. Results: The exposed subjects had significantly more cancer, respiratory, skin, and neurological health problems than the controls. The subjective responses on questionnaires and by physician histories revealed that the residents had a significantly greater prevalence of mucous membrane irritation, and skin and neurological symptoms, as well as cancer. (Exposed versus unexposed, cancer 10.0% versus 2.08%, bronchitis 17.8% versus 5.8%, and asthma by history 40.5% versus 11.0%) There were significantly more neurophysiologic abnormalities in adults of reaction time, trails A and B, and visual field defects. Conclusions: Adverse health effects were significantly more prevalent in long-term residents near a wood treatment plant than in controls. The results of this study suggest that plant emissions from wood treatment facilities should be reduced

  9. The Effect of Wood Alignment on Wood Grinding – Part 2: Fines Character and Microscopic Observations

    Directory of Open Access Journals (Sweden)

    Sabine Heinemann

    2016-01-01

    Full Text Available During industrial wood grinding, logs are pressed against a rotating stone, with the logs and fibre axes parallel to the axis of the stone. For this study, 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, the amount, and the quality of the fines were measured, and a grinding mechanism is proposed. In this paper, the obtained results showed that the pulp quality was highly sensitive to the angle between the stone surface and the log, and different for fatigue-based and force-based grinding. The tests were observed using microscopic techniques and discussed in terms of fines amount and fines quality. In gentle refining, the fibre structure is loosened by fatigue before it is bent on the surface, pressure pulses produce fibrillar material, and fibres develop good bonding ability. In forced grinding, the process is “violent” and the fibre wears and is crushed immediately on the surface into small particles with low bonding ability.

  10. Interaction of the wood surface with metal ions. Part 3: The effects of light on chromium impregnated wood surface

    International Nuclear Information System (INIS)

    Stipta, J.; Németh, K.; Molnárné Hamvas, L.

    2004-01-01

    UV-light changes of untreated and chromium impregnated wood surface were investigated by absorption spectrophotometric methods. The properties of indifferent silicagel and celulose layers were to the behaviour of poplar and black locust surface. Chromic-ion-impregnation had no significant effect on the absorption spectra of these layers. On the other hand, hexavalent chromium was reduced and UV-light caused irreversible wood degradation. Surface treatment caused considerable modification in black locust

  11. Implementation of new technologies in wood industry and their effect in wood products quality

    OpenAIRE

    ELVA ÇAUSHI; PANDELI MARKU

    2014-01-01

    There are about 300 companies producing furniture and about 250 small and medium enterprises (SME) producing sawn timber, which operate in the field of wood industry in Albania. This wood industry production is being challenged by the increasing demand in the domestic market, ranging from kitchen furniture to office and schools furniture, bedroom furniture, doors, windows, and saw timber in different dimensions. The production from the wood industry can fulfill about 80% of the domestic mark...

  12. The effect of control parameters to the quality of small-scale wood pellet combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ruusunen, M. (Oulu Univ. (Finland). Contol Engineering Lab.), Email: mika.ruusunen@oulu.fi; Korpela, T.; Bjoerkqvist, T. (Tampere Univ. of Technology (Finland). Dept. of Automation Science and Engineering), Email: timo.korpela@tut.fi, Email: tomas.bjorqvist@tut.fi

    2009-07-01

    The target is to clear out control variables and requirements for clean small-scale wood pellet combustion (<100 kW{sub th}). Experimental runs were carried out in the form of design of experiments (DOE) with two commercial 15 kW pellet burners, namely a horizontal gas-burner and a conventional horizontal burner in a 20 kW commercial pellet boiler. Analysed variables were fuel power, draught, air flows, and fuel feed period, and research variables were CO, O{sub 2} and efficiency. The target was to identify and characterise separately the magnitude and direction of the effect of each factor. After process identification and variable optimisation, the results show strong influence of the studied control parameters on the efficiency and the emissions. The effects and interactions between different process variables were rather similar with both burners. The major effects for CO levels were fuel feed and additionally draught affected in case of wood gas combustion. Additionally, the effects on combustion efficiency is described by draught, air feed and fuel feed period. Furthermore, the fuel feed period affected the excess air level in case of direct combustion principle. It was noticed, however, that the combustion properties and optimal parameter values vary significantly between the two cases. (orig.)

  13. The effect of some wood preservatives on the thermal degradation of Scots pine

    International Nuclear Information System (INIS)

    Tomak, Eylem D.; Baysal, Ergun; Peker, Huseyin

    2012-01-01

    Highlights: ► Scots pine samples were impregnated with 10 commercial wood preservatives. ► Thermal degradation of wood was evaluated by TG, DTG and DTA. ► The thermal behavior of treated wood differed from that of untreated wood. ► Boron containing wood preservatives yielded more charcoal than other preservatives. ► Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

  14. The effect of some wood preservatives on the thermal degradation of Scots pine

    Energy Technology Data Exchange (ETDEWEB)

    Tomak, Eylem D., E-mail: eylemdizman@yahoo.com [Karadeniz Technical University, Faculty of Forestry, Forest Industrial Engineering Department, 61080 Trabzon (Turkey); Baysal, Ergun, E-mail: bergun@mu.edu.tr [Mugla University, Faculty of Technology, Department of Wood Science and Technology, Kotekli, 48000 Mugla (Turkey); Peker, Huseyin, E-mail: peker100@hotmail.com [Artvin Coruh University, Faculty of Forestry, Forest Industrial Engineering Department, 06100 Artvin (Turkey)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer Scots pine samples were impregnated with 10 commercial wood preservatives. Black-Right-Pointing-Pointer Thermal degradation of wood was evaluated by TG, DTG and DTA. Black-Right-Pointing-Pointer The thermal behavior of treated wood differed from that of untreated wood. Black-Right-Pointing-Pointer Boron containing wood preservatives yielded more charcoal than other preservatives. Black-Right-Pointing-Pointer Boric oxide and metal compounds in the formulations may affect char weight. - Abstract: Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effectiveness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups.

  15. Thinning and riparian buffer configuration effects on down wood abundance in headwater streams in coniferous forests

    Science.gov (United States)

    Adrian Ares; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Down wood is associated with the function, structure, and diversity of riparian systems. Considerable knowledge has been generated regarding down wood stocks and dynamics in temperate forests, but there are few studies on effects of silvicultural practices and riparian buffer design on down wood, particularly in headwater streams. We analyzed interactive eff ects of...

  16. 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...

  17. 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.

  18. Wood and combating the greenhouse effect

    International Nuclear Information System (INIS)

    Lochu, Serge

    2004-01-01

    The article begins by recalling a number of definitions connected with the greenhouse effect and the involvement of trees and forests. Timber's direct role in carbon storage and the reduction of atmospheric carbon dioxide is then described. The results of modelling studies and the indirect effects of timber as a means for economising fossil energy are discussed. While the direct and indirect effects of timber products on the greenhouse phenomenon are clearly positive, actually increasing the share of timber in the market and thereby intensifying its contribution is another matter that relies on consumer behaviour. In this area, large-scale campaigns must continue. (authors)

  19. Essential Oil Variability and Biological Activities of Tetraclinis articulata (Vahl) Mast. Wood According to the Extraction Time.

    Science.gov (United States)

    Djouahri, Abderrahmane; Saka, Boualem; Boudarene, Lynda; Baaliouamer, Aoumeur

    2016-12-01

    In the present work, the hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) kinetics of essential oil (EO) extracted from Tetraclinis articulata (Vahl) Mast. wood was conducted, in order to assess the impact of extraction time and technique on chemical composition and biological activities. Gas chromatography (GC) and GC/mass spectrometry analyses showed significant differences between the extracted EOs, where each family class or component presents a specific kinetic according to extraction time, technique and especially for the major components: camphene, linalool, cedrol, carvacrol and α-acorenol. Furthermore, our findings showed a high variability for both antioxidant and anti-inflammatory activities, where each activity has a specific effect according to extraction time and technique. The highlighted variability reflects the high impact of extraction time and technique on chemical composition and biological activities, which led to conclude that we should select EOs to be investigated carefully depending on extraction time and technique, in order to isolate the bioactive components or to have the best quality of EO in terms of biological activities and preventive effects in food. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  20. Effects of wood smoke particles from wood-burning stoves on the respiratory health of atopic humans

    Directory of Open Access Journals (Sweden)

    Riddervold Ingunn

    2012-04-01

    Full Text Available Abstract Background There is growing evidence that particulate air pollution derived from wood stoves causes acute inflammation in the respiratory system, increases the incidence of asthma and other allergic diseases, and increases respiratory morbidity and mortality. The objective of this study was to evaluate acute respiratory effects from short-term wood smoke exposure in humans. Twenty non-smoking atopic volunteers with normal lung function and without bronchial responsiveness were monitored during three different experimental exposure sessions, aiming at particle concentrations of about 200 μg/m3, 400 μg/m3, and clean air as control exposure. A balanced cross-over design was used and participants were randomly allocated to exposure orders. Particles were generated in a wood-burning facility and added to a full-scale climate chamber where the participants were exposed for 3 hours under controlled environmental conditions. Health effects were evaluated in relation to: peak expiratory flow (PEF, forced expiratory volume in the first second (FEV1, and forced vital capacity (FVC. Furthermore, the effects were assessed in relation to changes in nasal patency and from markers of airway inflammation: fractional exhaled nitric oxide (FENO, exhaled breath condensate (EBC and nasal lavage (NAL samples were collected before, and at various intervals after exposure. Results No statistically significant effect of wood smoke exposure was found for lung function, for FENO, for NAL or for the nasal patency. Limited signs of airway inflammation were found in EBC. Conclusion In conclusion, short term exposure with wood smoke at a concentration normally found in a residential area with a high density of burning wood stoves causes only mild inflammatory response.

  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. Effect of wood fuels on power plant operability

    International Nuclear Information System (INIS)

    Orjala, M.; Ingalsuo, R.

    2001-01-01

    The objective of the research is to determine the critical properties of wood fuels on the basis of power plant operability, to determine the optimal conditions for reduction of harmful detriments, and to study how the storage and processing of wood fuels effect on the operability. Both the CFB and BFB technologies are studied. The project started in December 2000 and it will be ended by the end of 2002. Experts of the Fuels and Combustion research field of VTT Energy carry out the main parts of the research. Experts of the research field of Mineral Processing of VTT Chemical Technology, located in Outokumpu, and Kemian tutkimuspalvelut Oy/Oulu University, located in Outokumpu, participate in the analytics, and the research field of Materials and Manufacturing Technology of VTT Manufacturing Technology in Otaniemi participates in the research on material effects. System Technology Laboratory of Oulu University carries out the power plant automation and boiler control technology research under supervision of Professor Urpo Kortela. Co-operation with the materials research unit of EU's JRC, located in Petten, which started in the research 'Combustion of Forest Chips', will be continues in this research. Co-operation will be made with Swedish Vaermeforsk in the field of information exchange on experiences in utilisation of wood fuels in Swedish power plants and possibilities to join in the projects of Vaermeforsk in this research field. Following companies participate in the project: Etelae-Savon Energia Oy, Foster Wheeler Energia Oy, Kvaerner Pulping Oy, Simpele pasteboard factory of M-Real Oyj and Vaermeforsk AB (Sweden). (orig.)

  3. Health Effects of Operators in the Production of Wood Pellets

    Energy Technology Data Exchange (ETDEWEB)

    Hagstroem, K.; Arvidsson, H.; Bryngelsson, I.L.; Fedeli, C. [Oerebro Univ. (Sweden). Dept. of Occupational and Environmental Medicine; Eriksson, K. [Univ. Hospital of Umeaa (Sweden). Dept. of Occupational and Environmental Medicine; Andersson, E. [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Occupational and Environmental Medicine

    2006-07-15

    The environmental and energy policy in Sweden is aiming to replace fossil energy with renewable sources such as biofuels, e.g., wood Pellets produced from shavings and sawdust of pine and spruce. Reported health effects in the wood processing industries are airway, eye and skin irritation, reduced lung function as well as eczema. The aim of our study was to investigate the prevalence of airway and skin symptoms and measure lung function in a population of pellet operators in the Swedish wood industry. Additional reported acute effects from the airways, eyes, nose and skin were recorded. From May 2004 until April 2005 50 blue-collar workers from four Swedish pellet-producing industries were investigated. The study included a questionnaire about skin and airway symptoms (n=50), acute effect questionnaire (n=67; 44 individuals) as well as a test of the lung function (spirometry) before and after work shift (n=118; 39 individuals). Acute effects questionnaire and spirometry were done one to three times per participants and for the acute effects the worker had to assess their symptoms in the airways, eyes, nose and skin between 6 and 8 times during a day. The results from the symptom questionnaires were compared with reference data from other Swedish studies and the lung function data with a European reference material. Statistical tests used were chi-2-test for the questionnaire, t-test for lung function before shift compared expected values, and for difference in lung function between before and after work shift mixed models with subjects as a random factor. No statistical significant difference was seen for the skin and airway symptoms in the questionnaire. Reported acute effects were seen especially for eye and nose symptoms (table 1). Spirometry showed significantly higher forced vital capacity (FVC; p=0.0003) and no difference in forced expiratory volume in 1 second (FEV1; p=0.08) before work shift compared to expected values. FVC was 108,1 % and FEV1 was 104

  4. Effect of Trichoderma-enriched organic charcoal in the integrated wood protection strategy.

    Directory of Open Access Journals (Sweden)

    Javier Ribera

    Full Text Available The gradual elimination of chromium from wood preservative formulations results in higher Cu leaching and increased susceptibility to wood decay fungi. Finding a sustainable strategy in wood protection has become of great interest among researchers. The objective of these in vitro studies was to demonstrate the effect of T-720-enriched organic charcoal (biochar against five wood decay basidiomycetes isolated from strongly damaged poles. For this purpose, the antagonistic potential of Trichoderma harzianum (strain T-720 was confirmed among other four Trichoderma spp. against five brown-rot basidiomycetes in dual culture tests. T-720 was genetically transformed and tagged with the green fluorescent protein (GFP in order to study its antagonistic mechanism against wood decay basidiomycetes. It was also demonstrated that T-720 inhibits the oxalic acid production by basidiomycetes, a well-known mechanism used by brown-rot fungi to detoxify Cu from impregnated wood. Additionally, this study evaluated the effect of biochar, alone or in combination with T-720, on Cu leaching by different preservatives, pH stabilization and prevention of wood decay caused by five basidiomycetes. Addition of biochar resulted in a significant Cu binding released from impregnated wood specimens. T-720-enriched biochar showed a significant reduction of wood decay caused by four basidiomycetes. The addition of T-720-enriched biochar to the soil into which utility poles are placed may improve the efficiency of Cr-free wood preservatives.

  5. Heat treatment of wet wood fiber: A study of the effect of reaction conditions on the formation of furfurals

    Science.gov (United States)

    Mandla A. Tshabalala; James D. McSweeny; Roger M. Rowell

    2012-01-01

    Furan monomers are produced when wood is heated at high temperatures. To understand the process conditions for production of furfural (FF) and hydroxymethylfurfural (HMF) from wood, samples of milled aspen wood were subjected to autohydrolyzis by microwave heating in a sealed Teflon reactor. The experiments were designed to simulate temperature and pressure variables...

  6. Where there's smoke : health effects of wood smoke and risk reduction strategies

    Energy Technology Data Exchange (ETDEWEB)

    MacKinnon, B. [New Brunswick Lung Association, Fredericton, NB (Canada)

    2005-07-01

    This paper presents a summary of a discussion at a former workshop on smoke from both forest fires and wood stoves. Climate change is forecasted to increase the occurrence of forest fires in Canada and climate change mitigation measures may increase the use of wood stoves for home heating, resulting in an increase in respiratory and cardiovascular symptoms in the Canadian population. These health effects of wood smoke include: headaches and allergies; breathing difficulties; reduced lung function; aggravated heart disease; and increased susceptibility to lower respiratory tract infections. This paper also presented information on health effects of wood smoke and research recommendations for improved policies to protect human health. tabs., figs.

  7. 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.

  8. 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...

  9. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, M. E.; Gyenge, J. E.; Urquiza, M. M.; Varela, S.

    2012-11-01

    More stressful conditions are expected due to climatic change in several regions, including Patagonia, South-America. In this region, there are no studies about the impact of severe drought events on growth and wood characteristics of the most planted forestry species, Pinus ponderosa (Doug. ex-Laws). The objective of this study was to quantify the effect of a severe drought event on annual stem growth and functional wood anatomy of pines growing at different plantation densities aiming to understand how management practices can help to increase their adaptability to climate change. Growth magnitude and period, specific hydraulic conductivity, and anatomical traits (early- and late wood proportion, lumen diameter, cell-wall thickness, tracheid length and bordered pit dimensions) were measured in the ring 2008-2009, which was formed during drought conditions. This drought event decreased annual stem growth by 30-38% and 58-65% respect to previous mean growth, in open vs. closed stand trees, respectively, indicating a higher sensitivity of the latter, which is opposite to reports from the same species growing in managed native forests in USA. Some wood anatomical variables did differ in more water stressed trees (lower cell wall thickness of early wood cells and higher proportion of small-lumen cells in late wood), which in turn did not affect wood function (hydraulic conductivity and resistance to implosion). Other anatomical variables (tracheid length, pit dimensions, early- and late wood proportion, lumen diameter of early wood cells) did not differ between tree sizes and plantation density. The results suggest that severe drought affects differentially the amount but not the function and quality of formed wood in ponderosa pine growing at different competition levels. (Author) 41 refs.

  10. Wood variables affecting the friction coefficient of spruce pine on steel

    Science.gov (United States)

    Truett J. Lemoine; Charles W. McMillin; Floyd G. Manwiller

    1970-01-01

    Wood of spruce pine, Pinus glabra Walk., was factorially segregated by moisture content (0, 10, and 18 percent), specific gravity (less than 0.45 and more than 0.45), and extractive content (unextracted and extractive-freE), and the kinetic coefficient of friction on steel (having surface roughness of 9 microinches RMS) determined for tangential...

  11. Health effects assessment of exposure to particles from wood smoke

    DEFF Research Database (Denmark)

    Nielsen, Elsa; Dybdahl, Marianne; Larsen, Poul Bo

    551,000 wood stoves and 48,000 wood boilers and the particle emission from these sources make up the most dominant source of particle emission in DK. It is estimated that this emission contributes to an annual increased PM2.5 level of 0.6 microgram/m³. From the dose-response relationships used...

  12. Biodegrading effects of some rot fungi on Pinus caribaea wood

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... species of white-rot fungi; Corioliopsis polyzona and Pleurotus squarrosulus, and two species of brown- rot fungi; Lentinus ... The results indicated that biodegradation by rot fungi differs in intensity according to the fungus ..... wood of coast red wood Sequoia Sempervirens (D. Don). For. Prod. J. 33(5): 15-20 ...

  13. Analytical inventory of process variables for sustainable development of a small business for integrated production of wood pellets

    Directory of Open Access Journals (Sweden)

    Merticaru Vasile

    2017-01-01

    Full Text Available The paper presents some theoretical considerations and the related deliverable results obtained within a research approach developed for analytically inventorying the process variables for a wood pellets micro-production activity integrated with self-providing crops of energetic willow. The study is part of a larger research approach intended to accurately define the appropriate specifications for developing a sustainable small business in this area. Within the particular research approach being discussed in the paper, some conceptual models have been structured and are proposed, based on process systematic analysis, as following: a model of the research general hypotheses; a model of the general conceptual research frame; a process flow model for the considered integrated processes, respectively wood pellets micro-production and energetic willow crops; a model for sustainability groups of indicators to be considered; two models for process variables inventorying and classification, one for each of the two considered integrated processes. After the research hypotheses are simplified by considering some particular implementing conditions, a final model of the investigated variables is submitted to discussion. Some adequate conclusions revealed by the research approach, together with some directions of further research development are finally identified and presented in the paper.

  14. Effect of precipitation pattern on leaching of preservative from treated wood and implications for accelerated testing

    Science.gov (United States)

    Stan Lebow

    2014-01-01

    There is a need to develop improved accelerated test methods for evaluating the leaching of wood preservatives from treated wood exposed to precipitation. In this study the effects of rate of rainfall and length of intervals between rainfall events on leaching was evaluated by exposing specimens to varying patterns of simulated rainfall under controlled laboratory...

  15. "Effect of Anxiety Reduction on Children's School Performance and Social Adjustment": Correction to Wood (2006)

    Science.gov (United States)

    Wood, Jeffrey J.

    2007-01-01

    Reports an error in "Effect of anxiety reduction on children's school performance and social adjustment" by Jeffrey Wood (Developmental Psychology, 2006[Mar], Vol 42[2], 345-349). The byline and author note should have included the author's middle initial, J. Thus, the byline and author note should refer to "Jeffrey J. Wood." The correction is…

  16. Effects of processing method and moisture history on laboratory fungal resistance of wood-HDPE composites.

    Science.gov (United States)

    Craig M. Clemons; Rebecca E. Ibach

    2004-01-01

    The purpose of this study was to clarify the effects of composite processing and moisture sorption on laboratory fungal resistance of wood-plastic composites. A 2-week water soaking or cyclic boiling-drying procedure was used to infuse moisture into composites made from high-density polyethylene filled with 50 percent wood flour and processed by extrusion, compression...

  17. Effect of simulated rainfall and weathering on release of preservative elements from CCA treated wood

    Science.gov (United States)

    Stan Lebow; R. Sam Williams; Patricia Lebow

    2003-01-01

    The release of arsenic from wood pressure-treated with chromated copper arsenate (CCA) can be decreased by application of wood finishes, but little is known about the types of finishes that are best suited for this purpose. This study evaluated the effects of finish water repellent content and ultraviolet (UV) radiation on the release of arsenic, copper, and chromium...

  18. Effects of permethrin treated wood on the subterranean termite Reticulitermes flavipes (Kollar) and comparison of solvent extraction for HPLC analysis of permethrin in wood

    Science.gov (United States)

    Mark Mankowski; Blossie Boyd; Geoffrey Webb

    2016-01-01

    Permethrin is a common insecticide used in wood preservation. It is an effective synthetic pyrethroid that is considered to be less toxic to higher organisms than organochlorine insecticides. In wood preservation, it can be used in combination with fungicides such as 3-iodo-2-propynyl butyl carbamate (IPBC). Permethrin has a dual mode of action as it is a repellent and...

  19. Effective technology of wood and gaseous fuel co-firing for clean energy production

    International Nuclear Information System (INIS)

    Zake, M.; Barmina, I.; Gedrovics, M.; Desnickis, A.

    2007-01-01

    The main aim of the study was to develop and optimise a small-scale experimental co-firing technique for the effective and clean heat energy production by replacing a proportion of fossil fuel (propane) with renewable one (wood biomass). Technical solutions of propane co-fire presenting two different ways of additional heat supply to the wood biomass are proposed and analysed. The experiments have shown that a better result can be obtained for the direct propane co-fire of the wood biomass, when the rate of wood gasification and the ignition of volatiles are controlled by additional heat energy supply to the upper portion of wood biomass. A less effective though cleaner way of heat energy production is the direct propane co-fire of volatiles when low-temperature self-sustaining burnout of the wood biomass controls the rate of the volatile formation, while additional heat energy supply to the flow of volatiles controls their burnout. The effect of propane co-fire on the heat production rate and the composition of polluting emissions is studied and analysed for different rates of the additional heat supply to the wood biomass and of the swirling air supply as well as for different charge of wood biomass above the inlet of the propane flame flow. (Authors)

  20. EFFECT OF ARTIFICIAL WEATHERING ON WOOD LAMINATES COLOR TREATED WITH TWO FINISHING PRODUCTS

    Directory of Open Access Journals (Sweden)

    Thais Jacob Mendes

    2016-03-01

    Full Text Available Weathering is one of the main reasons for the degradation of wood, especially its color. The application of finishes minimizes these effects. This study aimed to monitor the effect of artificial weathering on wood veneer of the species cumaru (Dipteryx odorata and pau marfim (Balfourodendron riedelianum with two finishes, the marine varnish and Cetol, with monitoring using a spectrophotometer. The samples were subjected to cycles of exposure to weathering for 20, 40, 52, 76, 124, 226, 430, 838 and 960 hours. The colorimetric parameters (L*, a*, b*, C and h* were measured before treatment, after application of the products and during the weathering time intervals. The application of finishes darkened veneer of cumaru wood and pau marfim in nature. However, in higher weathering times, both species returned to a lighter color, and even became lighter than the natural wood. The use of Cetol was more efficient, giving greater stability in the conservation of wood color of the species studied.

  1. 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.

  2. EFFECTS OF SOME BORON COMPOUNDS ON THE LEACHABILITY OF EUCALYPTUS (Eucalyptus camaldulensis Dehn. WOOD

    Directory of Open Access Journals (Sweden)

    Hüseyin Tan

    2003-04-01

    Full Text Available Wood preservation effectiveness of boron compounds against biological damagers and fire is well known. But these compounds are not widely used in preservation of wood because of their leachability from wood by rain water and making wood more hyroscopic than untreated wood in damp environments. Main aim of this study is; therefore, to improve the undesired leachability properties of some boron compounds by various water repellents (WRs. Aqueous solutions with polyethyleneglycole (PEG-400 of boric acid and sodium perborate were chosen as boron compounds. WRs were used as secondary treatment chemicals which were considered as dimensional stabilizer of wood and phsical bariers of boron retained at innerparts of treated wood. Results indicated that WRs were reduced leachability of boron from wood significantly (P<0.05. Boron salts applied with. PEG were more leachable than were of equeous solutions. WRs were not found effective on reducing the leachability of boron solved in PEG. Longer leaching time caused more leachant and reduction the phsical alleviation of WRs on boron leaching.

  3. 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.

  4. Effects of application methods and species of wood on color ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... methods. Key words: Waterborne varnishes, application methods, wood materials, color change. ... rate in open air conditions (Anderson et al., 1991). .... for topcoat application and they were held for drying for 3 weeks. Finally ...

  5. Biodegrading effects of some rot fungi on Pinus caribaea wood ...

    African Journals Online (AJOL)

    morelet) in Ijaiye Forest Reserve, 38 km northwest of Ibadan, Nigeria. The wood samples were inoculated separately with two species of white-rot fungi; Corioliopsis polyzona and Pleurotus squarrosulus, and two species of brownrot fungi; ...

  6. Effect of adding wood vinegar on cucumber (Cucumis sativus L) seed germination

    Science.gov (United States)

    Lei, Ming; Liu, Bingjie; Wang, Xiao

    2018-03-01

    Wood vinegar, a liquid by-product that was obtained from the condensed vapor generated during the biomass pyrolysis, had been reported as plant growth promotor, but the impact on the plant seeds was still not clear. Thus, we investigated the effects of wood vinegar on the germination and seedling growth of cucumber seeds through the germination experiments. The results showed that the different diluted wood vinegar addition showed no significant difference in the germination rates of cucumber seeds compared to those of the CK treatment (P > 0.05). However, the added wood vinegar at the 10000-time dilution significantly increased the root length and dry biomass of cucumber by 20.9 % and 5.92 %, respectively (P < 0.05). Therefore, the wood vinegar at an optimal time of dilution could be used a promising soaking agent for the seeds germination, and further enhance crop yields.

  7. Effect of wood ash application on soil solution chemistry of tropical acid soils: incubation study.

    Science.gov (United States)

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

    2002-12-01

    The objective of this study was to determine the effect of wood ash application on soil solution composition of three tropical acid soils. Calcium carbonate was used as a reference amendment. Amended soils and control were incubated for 60 days. To assess soluble nutrients, saturation extracts were analysed at 15 days intervals. Wood ash application affects the soil solution chemistry in two ways, as a liming agent and as a supplier of nutrients. As a liming agent, wood ash application induced increases in soil solution pH, Ca, Mg, inorganic C, SO4 and DOC. As a supplier of elements, the increase in the soil solution pH was partly due to ligand exchange between wood ash SO4 and OH- ions. Large increases in concentrations of inorganic C, SO4, Ca and Mg with wood ash relative to lime and especially increases in K reflected the supply of these elements by wood ash. Wood ash application could represent increased availability of nutrients for the plant. However, large concentrations of basic cations, SO4 and NO3 obtained with higher application rates could be a concern because of potential solute transport to surface waters and groundwater. Wood ash must be applied at reasonable rates to avoid any risk for the environment.

  8. EFFECTS OF EXTRACTIVES AND DENSITY ON NATURAL RESISTANCE OF WOODS TO TERMITE Nasutitermes corniger

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2015-12-01

    Full Text Available The evaluation of the natural resistance of wood to wood-destroying organisms is of fundamental importance in the choice of species to be used in buildings and furniture industry. Thus, the effects of extractives and wood density on biological resistance of Acacia mangium, Casuarina equisetifolia, Corymbia torelliana, Eucalyptus cloeziana, Tectona grandis and Caesalpinia echinata woods to the xylophagous termite Nasutitermes corniger was evaluated under laboratory conditions. Test samples, with dimensions of 2.00 x 2.54 x 0.64 cm (radial x tangential x longitudinal in four positions in pith-bark direction (internal heart, intermediate heart, outer heart and sapwood were taken. The woods were exposed to termite action for 28 days in no-choice feeding test. The samples not selected for the termite test were turned into sawdust and the extractive contents were obtained using the shavings that passed through the sieve of 40 and were retained in the sieve of 60 mesh. The wood natural resistance, within the pith-bark positions, for the studied species, is not correlated with the density and extractive content. However, among the woods, those with higher density and extractive content are more resistant. The woods with greater biological resistance to the termite Nasutitermes corniger (smaller mass loss, waste and survival time of insects are Corymbia torelliana and Caesalpinia echinata and of less resistance is Casuarina equisetifolia.

  9. Intense laser field effects on a Woods-Saxon potential quantum well

    Science.gov (United States)

    Restrepo, R. L.; Morales, A. L.; Akimov, V.; Tulupenko, V.; Kasapoglu, E.; Ungan, F.; Duque, C. A.

    2015-11-01

    This paper presents the results of the theoretical study of the effects of non-resonant intense laser field and electric and magnetic fields on the optical properties in an quantum well (QW) make with Woods-Saxon potential profile. The electric field and intense laser field are applied along the growth direction of the Woods-Saxon quantum well and the magnetic field is oriented perpendicularly. To calculate the energy and the wave functions of the electron in the Woods-Saxon quantum well, the effective mass approximation and the method of envelope wave function are used. The confinement in the Woods-Saxon quantum well is changed drastically by the application of intense laser field or either the effect of electric and magnetic fields. The optical properties are calculated using the compact density matrix.

  10. The Effects of Natural Weathering on Color Stability of Impregnated and Varnished Wood Materials

    Directory of Open Access Journals (Sweden)

    Turkay Turkoglu

    2015-01-01

    Full Text Available The aim of this study was to investigate effects of natural weathering on color stability of Scots pine (Pinus sylvestris L. and Oriental beech (Fagus orientalis L. impregnated with some chemicals [tanalith-E (TN-E, adolit-KD5 (AD-KD5, and chromated copper arsenate (CCA] and then varnished [synthetic varnish (SV and polyurethane varnish (PV]. While applying varnish increased lightness, impregnation decreased lightness of the wood specimens before natural weathering. Natural weathering caused greenish, bluish, and dark color tones of the wood surface. Total color change was increased with increasing exposure times in natural weathering. Untreated (control wood specimens exhibited higher color changes than the other wood specimens in all the stages of natural weathering. The total color changes of untreated Oriental beech specimens were less than untreated Scots pine specimens. The color stability of impregnated and varnished wood specimens gave better results than untreated and solely varnished wood specimens after natural weathering. The best color stability was obtained from both Oriental beech and Scots pine wood impregnated with TN-E before PV coating.

  11. 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)

  12. 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)

  13. 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...

  14. Effect of periodate on lignin for wood adhesive application

    NARCIS (Netherlands)

    Gosselink, R.J.A.; Dam, van J.E.G.; Jong, de E.; Gellerstedt, G.; Scott, E.L.; Sanders, J.P.M.

    2011-01-01

    Development of eco-friendly binders with no harmful emission during its complete life cycle is of high interest for the wood-based industry. In this paper, a fully renewable binder based on activated lignin and poly-furfuryl alcohol and a partly renewable lignin based phenol-formaldehyde (PF) binder

  15. Interacting effects of insects and flooding on wood decomposition.

    Science.gov (United States)

    Michael Ulyshen

    2014-01-01

    Saproxylic arthropods are thought to play an important role in wood decomposition but very few efforts have been made to quantify their contributions to the process and the factors controlling their activities are not well understood. In the current study, mesh exclusion bags were used to quantify how arthropods affect loblolly pine (Pinus taeda L.) decomposition rates...

  16. Effect of acetyl groups of wood on furfural preparation

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, S.V.; Kolchina, N.P.; Miroshnichenko, V.G.

    1981-01-01

    The deacetylation (4% Na/sub 2/CO/sub 3/, 60 degrees) of birch sawdust prior to hydrolysis decreased the yield of furfural, presumably due to thermal degradation of pentosans and buildup of HCOOH in the wood stock. Thus, while untreated birch sawdust gave 6.6% furfural, the acetylated sawdust gave only 4.5% furfural.

  17. EFFECT OF LIGNIN CONTENT OF Eucalyptus globulus WOOD IN KRAFT PULPING PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Gabriel Valim Cardoso

    2011-03-01

    Full Text Available In this research, it was analyzed the lignin content effect of Eucalyptus globulus wood in kraft pulping optimization. Seventy-two laboratory cooking were made with wood chips obtained from six Eucalyptus globulus trees selected from a group of 50 trees. The wood chips from three trees with the lowest lignin content, with average 20,53%, were mixed proportionally based on the tree weights, obtaining the sample of low lignin content wood. The same was made to obtain the sample for wood chips with the highest lignin content, with average 23,02%. The two lignin levels were statistically different. The two wood samples had basic densities statistically not different. Using three maximum temperatures levels (160, 165 and 170ºC, and three active alkali charged (17, 18,5 and 20%, the wood chips were converted to kraft pulps. The pulps were then characterized to analyze the influence of the distinct treatments employed in the cooking on their properties. The effect of the cooking conditions was expressed by mathematical models in order to determine the optimum points for each of the evaluated properties. The optimization process indicated maximum temperature of 168ºC, and active alkali of 19%, for maximum kraft pulping yield to achieve kappa number 18; this result was for woods with low lignin content. For woods containing the high lignin content, the optimization showed maximum cooking temperature of 169ºC and active alkali of 19% for kappa number of 18. The average reduction of 2,49% in wood lignin content resulted a correspondent gain of 2,2% in the kraft yield (o.d. basis and a reduction on the active alkali charge of 1,2% (o.d. basis to achieve kappa numbers from 16 to 19, preserving pulp properties. If the option is to work with kappa number 19 instead of 16, the gain in kraft yield is approximately 2%. Therefore, when working with low lignin content wood and kappa number 19 instead of 16, a substantial gain of approximately 4,2% is obtained

  18. The Effect of Wood Fuels on Power Plant Availability

    Energy Technology Data Exchange (ETDEWEB)

    Orjala, Markku (Markku.Orjala@vtt.fi); Kaerki, Janne; Vainikka, Pasi [VTT Processes, Jyvaeskylae (Finland)

    2003-11-01

    There is a growing international interest in utilising renewable fuels, also in multifuel applications. Main reasons for this are the objective to reduce CO{sub 2} emissions and meet emission limits for NO{sub x} and SO{sub 2}. On one hand cofiring, defined as simultaneous combustion of different fuels in the same boiler, provides an alternative to achieve emission reductions. This is not only accomplished by replacing fossil fuel with biomass, but also as a result of the interaction of fuel reactants of different origin (e.g. biomass vs. coal). On the other hand, utilisation of solid biofuels and wastes sets new demands for process control and boiler design, as well as for combustion technologies, fuel blend control and fuel handling systems. In the case of wood-based fuels this is because of their high reactivity, high moisture content and combustion residues' high alkaline metal content. Combustion and cofiring properties of fuels have been studied both in VTT Processes' test facilities and in industrial-scale power plant boilers. The formation of alkaline and chlorine compounds in biomass combustion and their effect on boiler fouling and corrosion have been monitored by temperature controlled deposit formation and material monitoring probes. Deposit formation monitoring at full-scale boilers provides unique information on the rate of deposit formation, the effect of sootblowing and consequent changes in heat transfer. Additionally, the data from deposit formation monitoring has been shown to correlate with boiler performance, which gives basis for studying the interrelation of: fuel blend characteristics; deposit formation; boiler performance. If biomass fuels are blended with coal or peat, following implications may be expected: increased rate of deposit formation, shorter sootblowing interval, cleaning of heat transfer surfaces in revisions may be required, bed material agglomeration (in fluidised beds), increased risk of corrosion, higher in

  19. 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.

  20. Numerical Study of Focusing Effects of Microwaves inside Wood Due to Timber Ring Structure

    Directory of Open Access Journals (Sweden)

    Rocio Sanchez-Montero

    2018-02-01

    Full Text Available The aim of this study is the detailed calculation of microwave propagation inside raw timber in cylindrical configurations. Two different approaches have been used. The first one uses an exact formulation and analytical approximations in order to explore the electromagnetic field distribution inside dry wood. The introduction of conductivity in the exact model makes it so complex that the equations are unsuitable for analytical manipulation. In order to further explore the effect of moisture in cylindrical wood structures, a full scale numerical simulation using commercial software has been performed. The results show that for microwave frequencies in the 3 GHz range and for typical wood parameters, a cylindrical log behaves as a kind of Fresnel lens. This work has important applications in microwave treatment and sensing of wood.

  1. Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

    Science.gov (United States)

    Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

    2015-10-01

    Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

  2. Factors affecting the laser processing of wood, 2: Effects of material parameters on machinability

    International Nuclear Information System (INIS)

    Arai, T.; Hayashi, D.

    1994-01-01

    Material parameters of wood were investigated. Factors relating to the workpiece include cutting direction, specific gravity, and components of the wood such as resin-like materials. Also studies of the effects of irregular tissue on machinability were made. The interactions between laser beam and materials are often greatly complex. They depend on the characteristics of the laser beam, the thermal constants of the woods, and the optical surface properties of the woods. Therefore, high quality beam mode and carefully selected materials were used. The following laser cutting properties became clear after studying the experimental results. Slow speed cutting and softwoods make slight differences, regarding cutting section and fiber direction. However, it can beconsidered that there is not very much change except in cross-section. Because of the high power density of laser, cutting speed makes no big difference. The irregular tissue of wood cannot maintain normal cutting speed and accuracy. The factor of genuine density eta, which is thought to be entirely independent of each specific gravity, is definedas the concept of density in general. It can be obtained by applying a simple rule, that is, the eta is the ratio of r(u)/rho(s) where rho(s) is the wood substance as the characteristic value of wood, and r(u)is specific gravity. An experimental formula shows that the depth of cut decreases in proportion to the value of eta. However, in the strict sense of the word, data of wood material as a natural resources mustbe treated qualitatively, because there are deviations from regularity due to various reasons. (author)

  3. Effects of Wood Pollution on Pore-Water Sulfide Levels and Eelgrass Germination

    Science.gov (United States)

    Ekelem, C.

    2016-02-01

    Historically, sawmills released wood waste onto coastal shorelines throughout the Pacific Northwest of the USA, enriching marine sediments with organic material. The increase in organic carbon boosts the bacterial reduction of sulfate and results in the production of a toxic metabolite, hydrogen sulfide. Hydrogen sulfide is a phytotoxin and can decrease the growth and survival of eelgrass. This is a critical issue since eelgrass, Zostera marina, forms habitat for many species, stabilizes sediment, and plays a role in nutrient cycling and sediment chemistry. The objective of our study was to determine the effects of wood debris on sediment pore-water hydrogen sulfide concentrations and eelgrass germination. To test the impact of wood inputs on sulfide production and seed germination, we conducted a laboratory mesocosm experiment, adding sawdust to marine sediments and measuring the sulfide levels weekly. We subsequently planted seeds in the mesocosms and measured germination rates. Higher concentrations of sawdust led to higher levels of pore-water hydrogen sulfide and drastically slower eelgrass germination rates. Treatments with greater than 10% wood enrichment developed free sulfide concentrations of 0.815 (± 0.427) mM after 118 days, suggesting sediments with greater than 10% wood pollution may have threateningly high pore-water hydrogen sulfide levels. These results can be used to set thresholds for remediation efforts and guide seed distribution in wood polluted areas.

  4. Simulated long-term effects of varying tree retention on wood production, dead wood and carbon stock changes.

    Science.gov (United States)

    Santaniello, Francesca; Djupström, Line B; Ranius, Thomas; Weslien, Jan; Rudolphi, Jörgen; Sonesson, Johan

    2017-10-01

    Boreal forests are an important source of timber and pulp wood, but provide also other products and services. Utilizing a simulation program and field data from a tree retention experiment in a Scots pine forest in central Sweden, we simulated the consequences during the following 100 years of various levels of retention on production of merchantable wood, dead wood input (as a proxy for biodiversity), and carbon stock changes. At the stand level, wood production decreased with increased retention levels, while dead wood input and carbon stock increased. We also compared 12 scenarios representing a land sharing/land sparing gradient. In each scenario, a constant volume of wood was harvested with a specific level of retention in a 100-ha landscape. The area not needed to reach the defined volume was set-aside during a 100-year rotation period, leading to decreasing area of set-asides with increasing level of retention across the 12 scenarios. Dead wood input was positively affected by the level of tree retention whereas the average carbon stock decreased slightly with increasing level of tree retention. The scenarios will probably vary in how they favor species preferring different substrates. Therefore, we conclude that a larger variation of landscape-level conservation strategies, also including active creation of dead wood, may be an attractive complement to the existing management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The Effect of Ultraviolet Light on the "Liquid Wood"

    Science.gov (United States)

    Dumitru, Nedelcu; Sabina, Zǎgan; Ticuta, Negreanu-Pirjol; Remus, Zǎgan; Constantin, Cǎrausu

    2014-08-01

    To preserve resources, the goal is to use biobased materials containing the maximum possible amount of renewable biomass-based derivatives to secure a sustainable future. Bioplastics, biocomposites, biological fibres and related biomaterials will serve as substitutes for materials and products traditionally made from petroleum resources. To support this need, in 1998, Fraunhofer Institute of Chemistry and Tecnaro GmbH Company (founded by Jurgen Pfitzer and Helmut Nagele in Germany) investigated and developed a new compound made of wood components that can be processed as a thermoplastic material. It is well known that bioplastic and biocomposite materials represent another important group of bio-materials that include plastics reinforced with natural fibers and wood-plastic composites (WPCs). The aim of this research is to identify the behavior of "Liquid Wood" after UV irradiation. The materials used were Arbofill Fichte, Arboblend V2 Nature and Arboform L, V3 Nature. The samples were obtained by injection and the experimental study plan followed the Taguchi method with six input parameters and two levels for each of them. Three samples from each material were tested in an ultraviolet environment using different time of exposure in order to establish the material characteristics. After the irradiation process the material did not turn to yellow, which suggests that the composition of the sample liquid timber inhibitors have stability and the number of α-carbonyl (C = O) groups is sufficiently low. After the graphs analyzing can be inferred relatively similar performance of the samples in the first stage both UV and the VIS, indicating that the activity is almost absent. In UV is clearly observed the peak amplitude (maximum absorbance) at different wavelengths (λ). So, in terms of peak intensity the samples follow the order: Arboform L, V3 Nature; Arbofill Fichte and Arboblend V2 Nature.

  6. Compensatory mechanisms mitigate the effect of warming and drought on wood formation.

    Science.gov (United States)

    Balducci, Lorena; Cuny, Henri E; Rathgeber, Cyrille B K; Deslauriers, Annie; Giovannelli, Alessio; Rossi, Sergio

    2016-06-01

    Because of global warming, high-latitude ecosystems are expected to experience increases in temperature and drought events. Wood formation will have to adjust to these new climatic constraints to maintain tree mechanical stability and long-distance water transport. The aim of this study is to understand the dynamic processes involved in wood formation under warming and drought. Xylogenesis, gas exchange, water relations and wood anatomy of black spruce [Picea mariana (Mill.) B.S.P.] saplings were monitored during a greenhouse experiment where temperature was increased during daytime or night-time (+6 °C) combined with a drought period. The kinetics of tracheid development expressed as rate and duration of the xylogenesis sub-processes were quantified using generalized additive models. Drought and warming had a strong influence on cell production, but little effect on wood anatomy. The increase in cell production rate under warmer temperatures, and especially during the night-time warming at the end of the growing season, resulted in wider tree-rings. However, the strong compensation between rates and durations of cell differentiation processes mitigates warming and drought effects on tree-ring structure. Our results allowed quantification of how wood formation kinetics is regulated when water and heat stress increase, allowing trees to adapt to future environmental conditions. © 2015 John Wiley & Sons Ltd.

  7. Priority effects of early successional insects influence late successional fungi in dead wood.

    Science.gov (United States)

    Jacobsen, Rannveig Margrete; Birkemoe, Tone; Sverdrup-Thygeson, Anne

    2015-11-01

    Community assembly is an integral process in all ecosystems, producing patterns of species distributions, biodiversity, and ecosystem functioning. Environmental filters and colonization history govern the assembly process, but their relative importance varies depending on the study system. Dead wood decomposition is a slow process, allowing decomposer communities to develop within a slowly changing substrate for decades. Despite this, there are few long-term studies of priority effects from colonization history in this ecosystem. In this study, we investigate the importance of insects in early succession of dead wood on the fungal community present one decade later. Sixty aspen trees were killed in two study landscapes, each tree producing one aspen high stump and log. Insects were sampled with flight interception traps during the first 4 years after tree death, and fungal fruiting bodies were registered in year twelve. We found positive priority effects of two fungivorous beetles, the sap beetle Glischrochilus quadripunctatus and the round fungus beetle Agathidium nigripenne, on the Artist's bracket (Ganoderma applanatum) and a positive priority effect of wood-boring beetles on the ascomycete Yellow fairy cup (Bisporella citrina). The Aspen bracket (Phellinus tremulae) did not respond to insects in early succession of the dead wood. Our results suggest that early successional insects can have significant, long-lasting effects on the late successional fungal community in dead wood. Also, the effect can be specific, with one fungus species depending on one or a few fungivorous beetle species. This has implications for decomposition and biodiversity in dead wood, as loss of early colonizing beetles may also affect the successional pathways they seem to initiate.

  8. Evaluation of wood structure using GPR with FO method - Effect of moisture, fibers direction and density

    Science.gov (United States)

    Chinh Maï, Tien; Reci, Hamza; Sbartaï, Zoubir Mehdi; Pajewski, Lara; Marciniak, Marian

    2017-04-01

    This work deals with the potential of GPR method in the evaluation of wood structure in relation with density of wood (different wood species), the orientation of fibers and water content (Maï et al., 2015; Reci et al., 2016). The system of measurements is the georadar type (GPR-ground penetrating radar) composed of an electromagnetic signal generator (SIR 3000 of GSSI), and one couple of antennas, one Transmitter (T) and a Receiver (R) of 1.5GHz center frequency, located in the same box in a fixed distance of 6cm. Six wood samples are tested, three samples of Epicea and three samples of Pine. To compare and analyze the results of dielectric constants, we have used the data on three principal directions (Transvesal, Longitudinal and Radial). We note that the dielectric constant of wood increases with the moisture by mass as a consequence of increasing polarization and the conduction phenomena. This effect is more distinguished when the electric field is polarized parallel to the fibers than in perpendicular direction. The smallest contrasts are observed in the radial direction. We conclude that is more appropriate to evaluate the water content along the parallel direction of fibers. In this case we observe the maximum of contrasts of dielectric contrasts between dry and humidity states. Differences on dielectric constant, spectras and amplitudes are taken between different wood samples. Knowing that the dielectric constant is related to the capacity of polarizing (dependent on the water quantity), the increasing of water content could explain the difference of values obtained for the dielectric constants between two kinds of wood. Acknowledgement The Authors are grateful to COST - European Cooperation in Science and Technology (www.cost.eu) for funding the Action TU1208 "Civil engineering applications of Ground Penetrating Radar" (www.GPRadar.eu). We acknowledge also the French National Research Agency (ANR) for supporting this study through the Xylo-plate project

  9. 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.

  10. Hygrothermal Simulation of Wood Exposed To the Effect of External Climate

    Science.gov (United States)

    Dohnal, Jakub; Hradil, Petr; Pencik, Jan

    2017-10-01

    The article is focused on simulation of moisture transfer in wood of norway spruce (Picea abies L.). Experimental specimen was exposed to the northern climatic conditions in Lund University, Sweden. The moisture content of wood was measured 10 mm from the surface for nearly three years. The ABAQUS program was used for numerical modelling of moisture transfer simulation in 3D. The surface sorption of wood was simulated using user defined subroutine DFLUX developed by VTT Research Centre of Finland Ltd. for the needs of European Project Durable Timber Bridges. Climate data for the analysis was used from insitu measurement nearby realized by weather station. The temperature, relative humidity of the air and precipitation data was record each hour. Numerical analysis took into account influence of rain effect on different parts of specimen surface.

  11. Effect of constituent elements in wood on X-ray densitometry measurements

    International Nuclear Information System (INIS)

    Kouris, K.; Tout, R.E.; Gilboy, W.B.; Spyrou, N.M.

    1981-01-01

    Small concentrations of elements introduced into a wood matrix have been shown by calculation to measurably influence the photon mass attenuation coefficient although the corresponding changes in the physical density are negligible. This has implications in dendrochronology where the interpretation of densitometric data is based on X-ray radiographs of wood. The magnitude of such effects has been evaluated for selected elements by simulating various botanical matrices. Significant matrix to matrix differences in the mass attenuation coefficient, in the energy range of interest (5 to 25 keV), have been established as being due to variations in the mineral composition. (author)

  12. 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.

  13. Health effects of wood smoke. A literature review; Gezondheidseffecten van houtrook. Een literatuurstudie

    Energy Technology Data Exchange (ETDEWEB)

    Hagens, W.I.; Van Overveld, A.J.P.; Fischer, P.H.; Gerlofs-Nijland, M.E.; Cassee, F.R.

    2012-02-15

    In the Netherlands, the most commonly cited source of odour nuisance in the surrounding environment is the burning of wood in fireplaces and wood burning stoves. Fears concerning the health effects of inhaled wood smoke may also be an issue. Various chemical substances are emitted when wood is burnt in fireplaces and wood burning stoves, such as particulate matter, carbon monoxide, different volatile organic compounds and polycyclic aromatic hydrocarbons (PAHs). However, based on the research available, it is not possible to accurately estimate the extent to which these emissions can cause health effects. One reason for this is the large variation in the composition of wood smoke which is linked to the type of wood burning stove or fireplace, the type of fuel and heating behaviour. The results of the many different studies investigating the effects of wood burning on human health vary. While some studies have found an association between exposure to wood smoke and increased (hospital admissions for) cardiovascular disease, respiratory symptoms and decreased lung function, other studies have not found an association between health effects and wood smoke. Currently, particulate matter originating from the burning of wood is not considered more detrimental to human health than that from other sources of combustion, such as traffic. These are the most important results of a literature review carried out by the RIVM on the potential health effects of exposure to wood smoke. The studies included in the literature review were primarily performed in areas where wood burning fireplaces and stoves are the only source of domestic heating. As this situation rarely occurs in the Netherlands, extrapolation of the results of these studies to the situation in the Netherlands is problematic. An extensive survey of local exposure to harmful substances due to wood burning in the Netherlands is necessary to obtain more insight into the contribution of wood burning to local air

  14. Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams

    Science.gov (United States)

    Vladislav Gulis; Amy D. Rosemond; Keller Suberkropp; Holly S. Weyers; Jonathan P. Benstead

    2004-01-01

    We determined the effects of nutrient enrichment on wood decomposition rates and microbial activity during a 3-year study in two headwater streams at Coweeta Hydrologic Laboratory, NC, U.S.A. After a 1-year pretreatment period, one of the streams was continuously enriched with inorganic nutrients (nitrogen and phosphorus) for 2 years while the other stream served as a...

  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. Evaluation of effect of Ophiostoma novo-ulmi on four major wood ...

    African Journals Online (AJOL)

    Evaluation of effect of Ophiostoma novo-ulmi on four major wood species of the elm family in Rasht (North West of Iran) ... the diameter size of vessels and the number of xylary rays in four species: Ulmus carpinifolia, Ulmus glabra, Zelkova carpinifolia and Celtis australis as important factors in host resistance to elm disease.

  17. Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard

    Science.gov (United States)

    Xianjun Li; Zhiyong Cai; Eric Horn; Jerrold E. Winandy

    2011-01-01

    The main objective of this study was to evaluate the effect of oxalic acid (OA) wood chips pretreatment prior to refining, which is done to reduce energy used during the refining process. Selected mechanical and physical performances of medium-density fiberboard (MDF) – internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR), water absorption (WA)...

  18. 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...

  19. Effect of the steam explosion pretreatment on enzymatic hydrolysis of eucalyptus wood and sweet sorghum baggages

    International Nuclear Information System (INIS)

    Negro, M. J.; Martinez, J. M.; Manero, J.; Saez, F.; Martin, C.

    1991-01-01

    The effect of steam explosion treatment on the enzymatic hydrolysis yield of two different lignocellulosic substrates is studied. Raw materials have been pretreated in a pilot plant designed to work in batch and equipped with a reactor vessel of 2 1 working volume where biomass was heated at the desired temperature and then exploded and recovered in a cyclone. Temperatures from 190 to 230 degree celsius and reaction times from 2 to 8 min. have been assayed. The efficiency of the steam explosion treatment has been evaluated on the composition of the lignocellulosic materials as well as on their enzymatic hydrolysis yield using a cellulolytic complex from T. reesel. Results show a high solubilization rate of hemicelluloses and variable losses of cellulose and lignin depending on the conditions tested. Enzymatic hydrolysis yields of both substrates experimented remarkable increments, corresponding the highest values obtained to 210 degree celsius; 2 min. and 21O degree celsius; 4 min. for sorghum bagasse and eucalyptus wood respectively. (Author) 13 refs

  20. Effect of the steam explosion pretreatment on enzymatic hydrolysis of eucalyptus wood and sweet sorghum bagasse

    International Nuclear Information System (INIS)

    Negro, M.J.; Martinez, J.M.; Manero, J.; Saez, F.; Martin, C.

    1990-01-01

    The effect of steam explosion treatment on the enzymatic hydrolysis yield of two different lignocellulosic substrates is studied. Raw materials have been pretreated in a pilot plant designed to work in batch and equiped with a reactor vessel of 2 1 working volume where biomass was heated at the desired temperature and then exploded and recovered in a cyclone. Temperatures from 190 to 230 o C and reaction times from 2 to 8 min. have been assayed. The efficiency of the steam explosion treatment has been evaluated on the composition of the lignocellulosic materials as well as on their enzymatic hydrolysis yield using a cellulolytic complex from T. reesei. Results show a high solubilization rate of hemicelluloses ands variable losses of cellulose and lignin depending on the conditions tested. Enzymatic hydrolysis yields of both substrates experimented remarkable increments, correspondig the highest values obtained to 210 o C; 2 min. and 210 o C; 4 min. for sorghum bagasse and eucaliptus wood respectivelly. (Author). 13 refs

  1. Effect of raw wood supply system on the wood paying capability of a kraft pulp mill using Scots pine

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, O. (Helsinki Univ. of Technology, Espoo (Finland), Dept. of Forest Products Technology), Email: olli.dahl@tkk.fi; Jylhae, P. (Finnish Forest Research Inst., Kannus (Finland)), Email: paula.jylha@metla.fi; Laitila, J. (Finnish Forest Research Inst., Joensuu (Finland)), Email: juha.laitila@metla.fi; Kaerhae, K. (Metsaeteho Oy, Helsinki (Finland)), Email: kalle.karha@metsateho.fi

    2009-07-01

    Integration of energy wood procurement into that of pulpwood is seen as a means for reducing the high procurement costs of small-diameter wood harvested from first thinnings. In the deepest mode of integration, pulp and energy fractions are separated from each other in the debarking drum of the pulp mill. In the present paper, the competitiveness of the conventional supply chain based on cut-to-length harvesting was compared to the supply systems based on the harvesting of loose whole trees and whole-tree bundling, in the cases of three Scots pine-dominated first-thinning stands using wood paying capability (WPC) of a kraft pulp mill as a decisive criterion. Furthermore, the competitiveness of first thinnings as raw material sources for a pulp mill was evaluated by using intermediate thinnings as s reference. (orig.)

  2. Dead-wood addition promotes non-saproxylic epigeal arthropods but effects are mediated by canopy openness

    Science.gov (United States)

    Sebastian Seibold; Claus Bässler; Petr Baldrian; Lena Reinhard; Simon Thorn; Michael D. Ulyshen; Ingmar Weiß; Jörg Müller

    2016-01-01

    Restoring dead-wood amounts in forests is an increasingly and successfully applied conservation measure to counteract negative effects of intensive logging on biodiversity of saproxylic taxa. By contrast, if and how dead-wood addition benefits the vast number of non-saproxylic forest taxa, and how this varies with contextual factors like canopy openness, remains poorly...

  3. Effect of citric acid modification of aspen wood on sorption of copper ion

    Science.gov (United States)

    James D. McSweeny; Roger M. Rowell; Soo Hong Min

    2006-01-01

    Milled aspen wood was thermochemically modified with citric acid for the purpose of improving the copper (Cu2+) ion sorption capacity of the wood when tested in 24-hour equilibrium batch tests. The wood-citric acid adducts provided additional carboxyl groups to those in the native wood and substantially increased Cu2+ ion uptake of the modified wood compared with that...

  4. Evaluating the Effectiveness of a Commercial Portable Air Purifier in Homes with Wood Burning Stoves: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Julie F. Hart

    2011-01-01

    Full Text Available Wood burning for residential heating is prevalent in the Rocky Mountain regions of the United States. Studies have shown that wood stoves can be a significant source of PM2.5 within homes. In this study, the effectiveness of an electrostatic filter portable air purifier was evaluated (1 in a home where a wood stove was the sole heat source and (2 in a home where a wood stove was used as a supplemental heat source. Particle count concentrations in six particle sizes and particle mass concentrations in two particle sizes were measured for ten 12-hour purifier on and ten purifier off trials in each home. Particle count concentrations were reduced by 61–85 percent. Similar reductions were observed in particle mass concentrations. These findings, although limited to one season, suggest that a portable air purifier may effectively reduce indoor particulate matter concentrations associated with wood combustion during home heating.

  5. Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial Growth and Wood Density in Southern Portugal

    Science.gov (United States)

    Kurz-Besson, Cathy B.; Lousada, José L.; Gaspar, Maria J.; Correia, Isabel E.; David, Teresa S.; Soares, Pedro M. M.; Cardoso, Rita M.; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M.; Gouveia, Célia M.

    2016-01-01

    Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-ring width and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011. We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster’s vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster’s production capacity and quality in response to more arid conditions in the near future in the region. PMID:27570527

  6. Effects of Recent Minimum Temperature and Water Deficit Increases on Pinus pinaster Radial Growth and Wood Density in Southern Portugal.

    Science.gov (United States)

    Kurz-Besson, Cathy B; Lousada, José L; Gaspar, Maria J; Correia, Isabel E; David, Teresa S; Soares, Pedro M M; Cardoso, Rita M; Russo, Ana; Varino, Filipa; Mériaux, Catherine; Trigo, Ricardo M; Gouveia, Célia M

    2016-01-01

    Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events. To address this question, tree-ring width and density chronologies were built for a Pinus pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI) multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011. We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster's vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster's production capacity and quality in response to more arid conditions in the near future in the region.

  7. The Effect of Methylation and Anti-Oxidant on Discoloration of Weathered Wood Plastic Composites

    Directory of Open Access Journals (Sweden)

    Peivand Darabi

    2011-01-01

    Full Text Available As the outdoor application of Wood Plastic Composites (WPCs become more widespread, the resistance of these products against weathering, particularly ultraviolet (UV light becomes more important. When WPCs are exposed to outdoor ultraviolet light, rain, snow and atmosphere pollution, they will be degraded which can be indicated by color fade. To investigate the effects of methylation and Anti-Oxidant separately and together on discoloration of weathered wood plastic composites, composites of poplar wood flour and high density polyethylene.Were made according to the ASTMD 2565, samples were placed in Atlas Xenon apparatus for 250 and 2000 hours. Discoloration and FT-IR spectra of the samples were measured and compared. The results have shown that methylation in short term and long term can relatively reduce the discoloration of weathered samples and also in short term can hinder the photodegradation. FT-IR spectra showed that, in long term, neither of the treatments could protect lignin from irradiation within wood flour. But methylation limited the depth of penetration of weathering. The Antioxidant did not have an influence on color change in a long period of time, but was able to relatively decrease it in short term.

  8. Effect of Wood Aging on Wine Mineral Composition and 87Sr/86Sr Isotopic Ratio.

    Science.gov (United States)

    Kaya, Ayse D; Bruno de Sousa, Raúl; Curvelo-Garcia, António S; Ricardo-da-Silva, Jorge M; Catarino, Sofia

    2017-06-14

    The evolution of mineral composition and wine strontium isotopic ratio 87 Sr/ 86 Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87 Sr/ 86 Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87 Sr/ 86 Sr, not precluding the use of this parameter for wine traceability purposes.

  9. Development of a Tool to Measure the Effectiveness of Kaizen Events within the Wood Products Industry

    OpenAIRE

    Erdogan, Sevtap

    2015-01-01

    Kaizen implementation and other continuous improvement practices can be used by companies to lower manufacturing costs and increase product value. Kaizen activities are one way that wood products companies can increase their competitiveness. Being able to measure the effectiveness of Kaizen events is important to factors that contribute to Kaizen effectiveness as well as identifying the success of Kaizen implementation. However, little research has focused on the implementation of Kaizen and ...

  10. Effect of heat treatment of wood on the morphology, surface roughness and penetration of simulated and human blood.

    Science.gov (United States)

    Rekola, J; Lassila, L V J; Nganga, S; Ylä-Soininmäki, A; Fleming, G J P; Grenman, R; Aho, A J; Vallittu, P K

    2014-01-01

    Wood has been used as a model material for the development of novel fiber-reinforced composite bone substitute biomaterials. In previous studies heat treatment of wood was perceived to significantly increase the osteoconductivity of implanted wood material. The objective of this study was to examine some of the changing attributes of wood materials that may contribute to improved biological responses gained with heat treatment. Untreated and 140°C and 200°C heat-treated downy birch (Betula pubescens Ehrh.) were used as the wood materials. Surface roughness and the effect of pre-measurement grinding were measured with contact and non-contact profilometry. Liquid interaction was assessed with a dipping test using two manufactured liquids (simulated blood) as well as human blood. SEM was used to visualize possible heat treatment-induced changes in the hierarchical structure of wood. The surface roughness was observed to significantly decrease with heat treatment. Grinding methods had more influence on the surface contour and roughness than heat treatment. The penetration of the human blood in the 200°C heat-treated exceeded that in the untreated and 140°C heat-treated materials. SEM showed no significant change due to heat treatment in the dry-state morphology of the wood. The results of the liquid penetration test support previous findings in literature concerning the effects of heat treatment on the biological response to implanted wood. Heat-treatment has only a marginal effect on the surface contour of wood. The highly specialized liquid conveyance system of wood may serve as a biomimetic model for the further development of tailored fiber-composite materials.

  11. Effects of tanalith-e impregnation substance on bending strengths and modulus of elasticity in bending of some wood types

    Directory of Open Access Journals (Sweden)

    Hakan Keskin

    2016-04-01

    Full Text Available The aim of this study was to investigate the effects of impregnation with Tanalith-E on the bending strengths and modulus of elasticity in bending of some wood types. The test samples prepared from beech, oak, walnut, poplar, ash and pine wood materials - that are of common use in the forest products industry of TURKEY - according to TS 345, were treated with according to ASTM D 1413-76 substantially. Un-impregnated samples according to impregnated wood materials, the bending strengths in beech to 6.83%, 5.12% in ash, 5.93% in pine, the elasticity module values to 7.15% in oak and ash, at a rate of 6.58% in the higher were found. The highest values of bending strengths and modulus of elasticity in bending were obtained in beech and ash woods impregnated with Tanalith-E, whereas the lowest values were obtained in the poplar wood.

  12. 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).

  13. 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...

  14. 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.

  15. Baseline effects on carbon footprints of biofuels: The case of wood

    International Nuclear Information System (INIS)

    Johnson, Eric; Tschudi, Daniel

    2012-01-01

    As biofuel usage has boomed over the past decade, so has research and regulatory interest in its carbon accounting. This paper examines one aspect of that carbon accounting: the baseline, i.e. the reference case against which other conditions or changes can be compared. A literature search and analysis identified four baseline types: no baseline; reference point; marginal fossil fuel; and biomass opportunity cost. The fourth one, biomass opportunity cost, is defined in more detail, because this is not done elsewhere in the literature. The four baselines are then applied to the carbon footprint of a wood-fired power plant. The footprint of the resulting wood-fired electricity varies dramatically, according to the type of baseline. Baseline type is also found to be the footprint's most significant sensitivity. Other significant sensitivities are: efficiency of the power plant; the growth (or re-growth) rate of the forest that supplies the wood; and the residue fraction of the wood. Length of the policy horizon is also an important factor in determining the footprint. The paper concludes that because of their significance and variability, baseline choices should be made very explicit in biofuel carbon footprints. - Highlights: ► Four baseline types for biofuel footprinting are identified. ► One type, ‘biomass opportunity cost’, is defined mathematically and graphically. ► Choice of baseline can dramatically affect the footprint result. ► The ‘no baseline’ approach is not acceptable. ► Choice between the other three baselines depends on the question being addressed.

  16. Baseline effects on carbon footprints of biofuels: The case of wood

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Eric, E-mail: johnsonatlantic@gmail.com [Atlantic Consulting, 8136 Gattikon (Switzerland); Tschudi, Daniel [ETH, Berghaldenstrasse 46, 8800 Thalwil (Switzerland)

    2012-11-15

    As biofuel usage has boomed over the past decade, so has research and regulatory interest in its carbon accounting. This paper examines one aspect of that carbon accounting: the baseline, i.e. the reference case against which other conditions or changes can be compared. A literature search and analysis identified four baseline types: no baseline; reference point; marginal fossil fuel; and biomass opportunity cost. The fourth one, biomass opportunity cost, is defined in more detail, because this is not done elsewhere in the literature. The four baselines are then applied to the carbon footprint of a wood-fired power plant. The footprint of the resulting wood-fired electricity varies dramatically, according to the type of baseline. Baseline type is also found to be the footprint's most significant sensitivity. Other significant sensitivities are: efficiency of the power plant; the growth (or re-growth) rate of the forest that supplies the wood; and the residue fraction of the wood. Length of the policy horizon is also an important factor in determining the footprint. The paper concludes that because of their significance and variability, baseline choices should be made very explicit in biofuel carbon footprints. - Highlights: Black-Right-Pointing-Pointer Four baseline types for biofuel footprinting are identified. Black-Right-Pointing-Pointer One type, 'biomass opportunity cost', is defined mathematically and graphically. Black-Right-Pointing-Pointer Choice of baseline can dramatically affect the footprint result. Black-Right-Pointing-Pointer The 'no baseline' approach is not acceptable. Black-Right-Pointing-Pointer Choice between the other three baselines depends on the question being addressed.

  17. Effectiveness of the International Phytosanitary Standard ISPM No. 15 on reducing wood borer infestation rates in wood packaging material entering the United States.

    Science.gov (United States)

    Haack, Robert A; Britton, Kerry O; Brockerhoff, Eckehard G; Cavey, Joseph F; Garrett, Lynn J; Kimberley, Mark; Lowenstein, Frank; Nuding, Amelia; Olson, Lars J; Turner, James; Vasilaky, Kathryn N

    2014-01-01

    Numerous bark- and wood-infesting insects have been introduced to new countries by international trade where some have caused severe environmental and economic damage. Wood packaging material (WPM), such as pallets, is one of the high risk pathways for the introduction of wood pests. International recognition of this risk resulted in adoption of International Standards for Phytosanitary Measures No. 15 (ISPM15) in 2002, which provides treatment standards for WPM used in international trade. ISPM15 was originally developed by members of the International Plant Protection Convention to "practically eliminate" the risk of international transport of most bark and wood pests via WPM. The United States (US) implemented ISPM15 in three phases during 2005-2006. We compared pest interception rates of WPM inspected at US ports before and after US implementation of ISPM15 using the US Department of Agriculture AQIM (Agriculture Quarantine Inspection Monitoring) database. Analyses of records from 2003-2009 indicated that WPM infestation rates declined 36-52% following ISPM15 implementation, with results varying in statistical significance depending on the selected starting parameters. Power analyses of the AQIM data indicated there was at least a 95% chance of detecting a statistically significant reduction in infestation rates if they dropped by 90% post-ISPM15, but the probability fell as the impact of ISPM15 lessened. We discuss several factors that could have reduced the apparent impact of ISPM15 on lowering WPM infestation levels, and suggest ways that ISPM15 could be improved. The paucity of international interception data impeded our ability to conduct more thorough analyses of the impact of ISPM15, and demonstrates the need for well-planned sampling programs before and after implementation of major phytosanitary policies so that their effectiveness can be assessed. We also present summary data for bark- and wood-boring insects intercepted on WPM at US ports during 1984-2008.

  18. Effectiveness of the International Phytosanitary Standard ISPM No. 15 on reducing wood borer infestation rates in wood packaging material entering the United States.

    Directory of Open Access Journals (Sweden)

    Robert A Haack

    Full Text Available Numerous bark- and wood-infesting insects have been introduced to new countries by international trade where some have caused severe environmental and economic damage. Wood packaging material (WPM, such as pallets, is one of the high risk pathways for the introduction of wood pests. International recognition of this risk resulted in adoption of International Standards for Phytosanitary Measures No. 15 (ISPM15 in 2002, which provides treatment standards for WPM used in international trade. ISPM15 was originally developed by members of the International Plant Protection Convention to "practically eliminate" the risk of international transport of most bark and wood pests via WPM. The United States (US implemented ISPM15 in three phases during 2005-2006. We compared pest interception rates of WPM inspected at US ports before and after US implementation of ISPM15 using the US Department of Agriculture AQIM (Agriculture Quarantine Inspection Monitoring database. Analyses of records from 2003-2009 indicated that WPM infestation rates declined 36-52% following ISPM15 implementation, with results varying in statistical significance depending on the selected starting parameters. Power analyses of the AQIM data indicated there was at least a 95% chance of detecting a statistically significant reduction in infestation rates if they dropped by 90% post-ISPM15, but the probability fell as the impact of ISPM15 lessened. We discuss several factors that could have reduced the apparent impact of ISPM15 on lowering WPM infestation levels, and suggest ways that ISPM15 could be improved. The paucity of international interception data impeded our ability to conduct more thorough analyses of the impact of ISPM15, and demonstrates the need for well-planned sampling programs before and after implementation of major phytosanitary policies so that their effectiveness can be assessed. We also present summary data for bark- and wood-boring insects intercepted on WPM at US

  19. Kraft cooking of gamma irradiated wood, (1). Effect of alcohol additives on pre-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, M; Meshitsuka, G; Nakano, J [Tokyo Univ. (Japan). Faculty of Agriculture

    1979-12-01

    Studies have been made of kraft cooking of gamma irradiated wood. Beech (Fagus crenata Blume) wood meal suspended in aqueous alkaline alcohol was irradiated up to 1.5 KGy (0.15 Mrad) with gamma rays from a Co-60 source in the presence or absence of oxygen. The irradiated wood meals were washed thoroughly with fresh water, air dried and cooked under the ordinary cooking conditions. The results are summarized as follows: (1) Pre-irradiation in aqueous alkali have negligible effect on kraft cooking. (2) In the case of ethanol addition (50 g/l), pre-irradiation in vacuo shows acceleration of delignification and stabilization of carbohydrates during kraft cooking. Cooked yield gain by pre-irradiation was about 1.2 in all, over the range of delignification from 80 to 90%. Aqueous ethanol without alkali also shows positive but smaller effect than that with alkali. (3) Propanol, iso-propanol and butanol show positive but smaller effects than ethanol. However, methanol does not show any positive effect. (4) Irradiation in the presence of oxygen does not show any attractive effect on kraft cooking.

  20. Hidden Variables and Placebo Effects

    Science.gov (United States)

    Goradia, Shantilal

    2006-03-01

    God's response to prayers and placebo leads to a question. How does He respond deterministically? He may be controlling at least one of the two variables of the uncertainty principle by extending His invisible soul to each body particle locally. Amazingly, many Vedic verses support this answer. One describes the size of the soul as arithmetically matching the size of the nucleons as if a particle is a soul. One gives a name meaning particle soul (anu-atma), consistent with particle's indeterministic behavior like that of (soulful) bird’s flying in any directions irrespective of the direction of throw. One describes souls as eternal consistent with the conservation of baryon number. One links the souls to the omnipresent (param- atma) like Einstein Rosen bridges link particles to normal spacetime. One claims eternal coexistence of matter and soul as is inflationary universe in physics/0210040 V2. The implicit scientific consistency of such verses makes the relationship of particle source of consciousness to the omnipresent Supreme analogous to the relationship of quantum source of gravitons in my gr-qc/0507130 to normal spacetime This frees us from the postulation of quantum wormholes and quantum foam. Dr. Hooft's view in ``Does God play dice,'' Physicsword, Dec 2005 seems consistent with my progressive conference presentations in Russia, Europe, India, and USA (Hindu University) in 2004/05. I see implications for nanoscience.

  1. Quantitative evaluation of the lignin protective effect on cellulose under γ irradiation of wood

    International Nuclear Information System (INIS)

    Skvortsov, S.V.; Klimentov, A.S.

    1986-01-01

    Changes in the degree of polymerization (D-barP-bar v ) of pine and spruce wood cellulose gamma-irradiated in- and outside the vegetable tissue are studied by the viscometric method. It has been shown that in the absorbed dose range of 0-100 kGy the protective effect of lignin on radiation-induced destruction of cellulose is reduced from 122 and 107 % to 4.5 and 3.4 %, respectively. At higher doses the mentioned effect is completely absent. It has been established that the destruction of wood cellulose in- and outside the plant tissue obeys the law of randomness, and finds its satisfactory description in the following equation: 1/D-barP-bar' v -1/D-barP-bar v 0 =KD α

  2. 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.

  3. 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 %.

  4. 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.

  5. 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...

  6. Effect of fertilization on cell size in wood of Eucalyptus grandis Hill Ex Maiden

    Directory of Open Access Journals (Sweden)

    Luiz Santini Junior

    2010-12-01

    Full Text Available The use of fertilization in forest stands results in yield gains, yet little attention has been directed to its potential effects on the quality of wood produced. Information is scarce about the effect of fertilization on anatomical structures of older Eucalyptus wood. This work aims to study the effect of fertilization on tissue cell size of wood from a Eucalyptus grandis stand at age 21 years, the management system of which is based on selective thinning and fertilizer application at the start of the thinning season. Factors to consider include: presence or absence of fertilizers, two log positions and five radial (pith to bark positions. Results led to the conclusion that fertilization significantly influenced only vessel frequency. Vessel elements length was influenced by tree height. Fiber length, fiber diameter, fiber wall thickness, vessel elements length, vessel diameter and vessel frequency were influenced by the radial position of the sample in relation to the log. A positive correlation was observed between fiber length, fiber diameter, fiber wall thickness, vessel elements length, vessel diameter, ray width and radial position, while a negative correlation was observed between ray frequency and radial position.

  7. 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.

  8. The effects of wood storage on the chemical composition and indigenous microflora of eucalyptus species used in the pulping industry

    CSIR Research Space (South Africa)

    Ramnath, L

    2018-02-01

    Full Text Available Lipophilic extractives naturally occurring in wood tend to coalesce during pulping to form pitch deposits, which have particularly undesirable effects on the pulping process and quality of pulp produced. A chemical characterization of different...

  9. 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.

  10. 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

  11. Zone edge effects with variable rate irrigation

    Science.gov (United States)

    Variable rate irrigation (VRI) systems may offer solutions to enhance water use efficiency by addressing variability within a field. However, the design of VRI systems should be considered to maximize application uniformity within sprinkler zones, while minimizing edge effects between such zones alo...

  12. EFFECT OF SAPPAN WOOD (Caesalpinnia sappan L EXTRACT ON BLOOD GLUCOSE LEVEL IN WHITE RATS

    Directory of Open Access Journals (Sweden)

    Saefudin Saefudin

    2016-05-01

    Full Text Available Sappan wood or kayu secang (Caesalpinia sappan L. was reported of having medicinal properties, such as natural antioxidant, relieve vomiting of blood, and mix of ingredients for malaria drugs. The research was conducted to study the influence of ethanol extract from sappan wood on blood glucose level of white rats. The study of the blood glucose level in rats was carried out by using glucose tolerance method. It was measured by Refloluxs (Accutrend GC with Chloropropamide 50 mg/200 g BW (Body weight as positive control. The ethanol extracts were used in various concentrations 10, 20, 30, 40 and 50 mg/200 g BW per-oral and was observed every hour, beginning one hour before to 7 hours after the extract being administered. The results showed that treatment of ethanol extract of sappan wood by administer doses gave remarkable effect on the blood glucose level in white rat. It reduced the glucose level in the blood compared to the negative and positive control. Treatment of dose 30 mg/200 g BW gave similar effect to positive controls, while a dose of 50 mg/200 g BW gave lower blood glucose level (93 mg/dl than the positive controls.

  13. Effect of Urea Addition on Soda Pulping of Oak Wood

    OpenAIRE

    Cho, Nam-Seok; Matsumoto, Yuji; Cho, Hee-Yeon; Shin, Soo-Jeong; Oga, Shoji

    2008-01-01

    Many studies have been conducted to find a sulfur-free additive for alkaline pulping liquors that would have an effect similar to that of sulfide in kraft pulping. Some reagents that partially fulfill this role have been found, but they are too expensive to be used in the quantities required to make them effective. As an alternative method to solve air pollution problem and difficulty of pulp bleaching of kraft pulping process, NaOH-Urea pulping was applied. The properties of NaOH-Urea pul...

  14. Effect of oak wood barrel capacity and utilization time on phenolic and sensorial profile evolution of an Encruzado white wine.

    Science.gov (United States)

    Nunes, Paulo; Muxagata, Sara; Correia, Ana C; Nunes, Fernando M; Cosme, Fernanda; Jordão, António M

    2017-11-01

    Several studies have reported the influence of diverse winemaking technologies in white wine characteristics. However, the impact of the use of different oak wood barrel capacities and utilization time on the evolution of white wine phenolic content and sensorial characteristics are not usually considered. Thus the aim of this work was to evaluate the effect of oak wood barrel capacity and utilization time on the evolution of phenolic compounds, browning potential index and sensorial profile of an Encruzado white wine. For the 180 aging days considered, the use of new oak wood barrels induced a greater increase in global phenolic composition, including several individual compounds, such as gallic and ellagic acid, independently of the barrel capacity. Tendency for a lesser increase of the browning potential index values was detected for white wines aged in new oak wood barrels. The sensorial profile evolution, showed significant differences only for the aroma descriptors, namely for 'wood aroma' and 'aroma intensity', white wine aged in 225 L new oak wood barrels being the highest scored. The results show that, in general, the use of different capacities and utilization time of oak wood barrels used for white wine aging could play an important role in white wine quality. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  15. Effects of UV light and chromium ions on wood flavonoids

    International Nuclear Information System (INIS)

    Molnárné Hamvas, L.; Németh, K.; Stipta, J.

    2003-01-01

    The individual and simultaneous effect of UV light and chromium ions was investigated by spectrophotometric methods on inert surfaces impregnated with quercetin or robinetin. The UV-VIS spectra of the silica gel plates impregnated with these flavonoids were modified characteristically after irradiating ultraviolet light. Even a half an hour of irradiation has caused irreversible changes in the molecule structure. A certain chemical - presumably complexation - was concluded from the change of spectral bands assigned to flavonoids when impregnated with chromic ions. Hexavalent chromium caused more complex changes in the absorption spectra. The differences in the spectra could indicate either the oxidation and decomposition of flavonoids, or some kind of coordination process and the reduction of hexavalent chromium. The simultaneous application of UV light and chromium ions caused more pronounced effects. The complexation process between chromium(III) and flavonoid was completed

  16. Effects of mosquitofish (Gambusia affinis cues on wood frog (Lithobates sylvaticus tadpole activity

    Directory of Open Access Journals (Sweden)

    Katherine F. Buttermore

    2011-06-01

    Full Text Available We examined the changes in activity of wood frog (Lithobates sylvaticus tadpoles exposed to combinations of visual, chemical, and mechanical cues of the invasive mosquitofish (Gambusia affinis. We also examined whether the responses of the tadpoles to the predator cues were influenced by the short-term accumulation of chemical cues in the experimental container. In our experiment, the activity of wood frog (L. sylvaticus tadpoles was not affected by the presence of various cues from mosquitofish. Our experiment demonstrated that the repeated use of trial water can influence the activity level of tadpoles, regardless of the predator cue treatment used. Tadpoles in the first trial tended to be less active than tadpoles in subsequent trials. This effect does not appear to be mediated by the accumulation of predator cues since there was no significant interaction term. Our results suggest that short-term accumulation of predator chemical cues do not affect the behavior of wood frog tadpoles: however, our results suggest that the repeated use of the same water in consecutive trials may affect tadpole behavior, perhaps through the accumulation of conspecific chemical cues.

  17. Allergy adjuvant effect of particles from wood smoke and road traffic.

    Science.gov (United States)

    Samuelsen, Mari; Nygaard, Unni Cecilie; Løvik, Martinus

    2008-04-18

    There is growing evidence that in addition to augmenting the severity of asthma and allergic diseases, particulate air pollution also increases the incidence of allergy and asthma. We studied the adjuvant effect of particles from wood smoke and road traffic on the immune response to the allergen ovalbumin (OVA). OVA with and without particles was injected into one hind footpad of Balb/cA mice. All particles together with OVA significantly increased the level of OVA-specific immunoglobulin E (IgE) in serum, compared to groups given OVA or particles alone. Reference diesel exhaust particles (DEP) with OVA induced the highest levels of IgE, whereas no clear difference was observed between particles from road traffic and wood smoke. Road traffic particles collected in the autumn induced higher IgE values with OVA than corresponding particles collected during the winter season when studded tires are used, suggesting that studded tire-generated road pavement particles have less allergy adjuvant activity than exhaust particles. Compared to OVA or particles alone, all particles with OVA increased popliteal lymph node cell numbers, cell proliferation, ex vivo secretion of IL-4 and IL-10 after ConA stimulation, and the expression of several cell surface molecules (CD19, MHC class II, CD86 and CD23). Wood smoke particles with OVA induced somewhat higher cellular responses than road traffic particles, but less than DEP with OVA which seemed to be the most potent particle in inducing cellular as well as antibody responses. Thus, wood smoke particles had about the same capacity to enhance allergic sensitization as road traffic particles, but less than diesel exhaust particles.

  18. Allergy adjuvant effect of particles from wood smoke and road traffic

    International Nuclear Information System (INIS)

    Samuelsen, Mari; Nygaard, Unni Cecilie; Lovik, Martinus

    2008-01-01

    There is growing evidence that in addition to augmenting the severity of asthma and allergic diseases, particulate air pollution also increases the incidence of allergy and asthma. We studied the adjuvant effect of particles from wood smoke and road traffic on the immune response to the allergen ovalbumin (OVA). OVA with and without particles was injected into one hind footpad of Balb/cA mice. All particles together with OVA significantly increased the level of OVA-specific immunoglobulin E (IgE) in serum, compared to groups given OVA or particles alone. Reference diesel exhaust particles (DEP) with OVA induced the highest levels of IgE, whereas no clear difference was observed between particles from road traffic and wood smoke. Road traffic particles collected in the autumn induced higher IgE values with OVA than corresponding particles collected during the winter season when studded tires are used, suggesting that studded tire-generated road pavement particles have less allergy adjuvant activity than exhaust particles. Compared to OVA or particles alone, all particles with OVA increased popliteal lymph node cell numbers, cell proliferation, ex vivo secretion of IL-4 and IL-10 after ConA stimulation, and the expression of several cell surface molecules (CD19, MHC class II, CD86 and CD23). Wood smoke particles with OVA induced somewhat higher cellular responses than road traffic particles, but less than DEP with OVA which seemed to be the most potent particle in inducing cellular as well as antibody responses. Thus, wood smoke particles had about the same capacity to enhance allergic sensitization as road traffic particles, but less than diesel exhaust particles

  19. 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.

  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. Edge effects on moisture reduce wood decomposition rate in a temperate forest.

    Science.gov (United States)

    Crockatt, Martha E; Bebber, Daniel P

    2015-02-01

    Forests around the world are increasingly fragmented, and edge effects on forest microclimates have the potential to affect ecosystem functions such as carbon and nutrient cycling. Edges tend to be drier and warmer due to the effects of insolation, wind, and evapotranspiration and these gradients can penetrate hundreds of metres into the forest. Litter decomposition is a key component of the carbon cycle, which is largely controlled by saprotrophic fungi that respond to variation in temperature and moisture. However, the impact of forest fragmentation on litter decay is poorly understood. Here, we investigate edge effects on the decay of wood in a temperate forest using an experimental approach, whereby mass loss in wood blocks placed along 100 m transects from the forest edge to core was monitored over 2 years. Decomposition rate increased with distance from the edge, and was correlated with increasing humidity and moisture content of the decaying wood, such that the decay constant at 100 m was nearly twice that at the edge. Mean air temperature decreased slightly with distance from the edge. The variation in decay constant due to edge effects was larger than that expected from any reasonable estimates of climatic variation, based on a published regional model. We modelled the influence of edge effects on the decay constant at the landscape scale using functions for forest area within different distances from edge across the UK. We found that taking edge effects into account would decrease the decay rate by nearly one quarter, compared with estimates that assumed no edge effect. © 2014 John Wiley & Sons Ltd.

  2. The Effect of Heat Treatment on the chemical and color change of Black Locust (Robinia Pseudoacacia) wood flour

    Science.gov (United States)

    Yao Chen; Yongming Fan; Jianmin Gao; Nicole M. Stark

    2012-01-01

    The aim of this study was to investigate the effects of oxygen and moisture content (MC) on the chemical and color changes of black locust (Robinia pseudoacacia) wood during heat treatment. The wood flour was conditioned to different initial MCs and heated for 24 h at a constant temperature of 120°C in either oxygen or nitrogen atmosphere. The pH values and...

  3. Effect of thermal mass on life cycle primary energy balances of a concrete- and a wood-frame building

    International Nuclear Information System (INIS)

    Dodoo, Ambrose; Gustavsson, Leif; Sathre, Roger

    2012-01-01

    Highlights: ► The effect of thermal mass on life cycle primary energy balance of concrete and wood building is analyzed. ► A concrete building has slightly lower space heating demand than a wood alternative. ► Still, a wood building has a lower life cycle primary energy use than a concrete alternative. ► The influence of thermal mass on space heating energy use for buildings in Nordic climate is small. -- Abstract: In this study we analyze the effect of thermal mass on space heating energy use and life cycle primary energy balances of a concrete- and a wood-frame building. The analysis includes primary energy use during the production, operation, and end-of-life phases. Based on hour-by-hour dynamic modeling of heat flows in building mass configurations we calculate the energy saving benefits of thermal mass during the operation phase of the buildings. Our results indicate that the energy savings due to thermal mass is small and varies with the climatic location and energy efficiency levels of the buildings. A concrete-frame building has slightly lower space heating demand than a wood-frame alternative, due to the higher thermal mass of concrete-based materials. Still, a wood-frame building has a lower life cycle primary energy balance than a concrete-frame alternative. This is due primarily to the lower production primary energy use and greater bioenergy recovery benefits of the wood-frame buildings. These advantages outweigh the energy saving benefits of thermal mass. We conclude that the influence of thermal mass on space heating energy use for buildings located in Nordic climate is small and that wood-frame buildings with cogeneration based district heating would be an effective means of reducing primary energy use in the built environment.

  4. 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.

  5. 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.

  6. 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).

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. CCA retention and its effects on the bonding performance of decommissioned treated wood: a preliminary study

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; Mark Gibson; Chung Y. Hse

    2009-01-01

    Chromated copper arsenate (CCA) continues to be widely used as a wood preservative for industrial uses in the U.S. Disposal of treated wood is a potential long-term environmental liability. Current practices for disposing of decommissioned preservative-treated wood include landfilling and incineration, which are increasingly impractical due to environmental...

  12. Effects of Wood Ash Biomass Application on Growth Indices and Chlorophyll Content of Maize and Lima bean Intercrop

    Directory of Open Access Journals (Sweden)

    Rasheedat Ajala

    2017-07-01

    Full Text Available Wood ash generated from wood industries have enormous potential which can be utilized due to its properties which influences soil chemistry and fertility status of tropical acidic soils. Field experiments were conducted on an acidic sandy loam alfisol to investigate the effects of wood ash on the growth indices and chlorophyll content of maize and lima beans intercrop during the late and early seasons of 2014 and 2015 at Akure in the rainforest zone of southwestern Nigeria. The treatments were 100% sole maize with ash, 100% sole maize without ash, 75% maize + 25% lima beans with ash, 75% + 25% lima beans without ash, 50% maize + 50% lima beans with ash, 50% maize + 50% lima beans without ash, 25% maize + 75% lima beans with ash and 25% maize + 75% lima beans without ash. Wood ash was applied at 2.4kg/plot. Wood ash increased chlorophyll content in all amended treatments except in amended 25:75% maize-lima beans intercrop and 25:75% maize –lima beans intercrop without ash, however 75:25% maize-lima beans amended with wood ash significantly (P≥0.05 recorded the highest chlorophyll content. Growth parameters such as plant height, number of leaves, leaf area, leaf area index, leaf length, stem diameter, number of flowers, number of pods, weight of plant and total biomass of amended maize-lima beans intercrop were significantly (P≥0.05 increased by wood ash application. Based on experimental findings, 25:75% maize-lima beans intercrop and 75%:25% maize-lima beans intercrop amended with wood ash was concluded to be more recommendable in the study area.

  13. Effectiveness of the International Phytosanitary Standard ISPM No. 15 on reducing wood borer infestation rates in wood packaging material entering the United States

    Science.gov (United States)

    Robert A. Haack; Kerry O. Britton; Eckelhard G. Brockerhoff; Joseph F. Cavey; Lynn J. Garrett; Mark Kimberley; Frank Lowenstein; Amelia Nuding; Lars J. Olson; James Tumer; Kathryn N. Vasilaky

    2014-01-01

    Numerous bark- and wood-infesting insects have been introduced to new countries by international trade where some have caused severe environmental and economic damage. Wood packaging material (WPM), such as pallets, is one of the high risk pathways for the introduction of wood pests. International recognition of this risk resulted in adoption of International Standards...

  14. Synergistic Effect of Nanosilica Aerogel with Phosphorus Flame Retardants on Improving Flame Retardancy and Leaching Resistance of Wood

    Directory of Open Access Journals (Sweden)

    Xiaodan Zhu

    2014-01-01

    Full Text Available Nanosilica (Nano-SiO2 sol fabricated by a sol-gel process was introduced into wood modification with phosphorus flame retardants to improve the flame retardancy and leaching resistance of wood. The obtained materials were characterized by scanning electron microscopy and energy dispersive spectrometer (SEM-EDS, thermogravimetric analysis (TGA, cone calorimetric (CONE, and infrared spectroscopy (FT-IR. The residual rate of flame retardants before and after leaching was determinated by a leaching resistance. The results showed that the phosphorus flame retardants and SiO2 sol could reside in the poplar wood and are widely distributed in the vessels, pits, wood timber, and the spaces between wood cells of poplar substrate. TGA and CONE results indicated that the introduction of nano-SiO2 aerogel with phosphorus flame retardants had a significantly synergistic effect on improving the flame retardancy and inhibiting the release of smoke and toxic gases. In addition, the leaching resistance test, combined with infrared analysis and EDS analysis, confirmed that the phosphorus flame retardants were able to be fixed by SiO2 aerogel in the wood.

  15. Statistical identification of effective input variables

    International Nuclear Information System (INIS)

    Vaurio, J.K.

    1982-09-01

    A statistical sensitivity analysis procedure has been developed for ranking the input data of large computer codes in the order of sensitivity-importance. The method is economical for large codes with many input variables, since it uses a relatively small number of computer runs. No prior judgemental elimination of input variables is needed. The sceening method is based on stagewise correlation and extensive regression analysis of output values calculated with selected input value combinations. The regression process deals with multivariate nonlinear functions, and statistical tests are also available for identifying input variables that contribute to threshold effects, i.e., discontinuities in the output variables. A computer code SCREEN has been developed for implementing the screening techniques. The efficiency has been demonstrated by several examples and applied to a fast reactor safety analysis code (Venus-II). However, the methods and the coding are general and not limited to such applications

  16. Modeling the Effect of Geomorphic Change Triggered by Large Wood Addition on Salmon Habitat in a Forested Coastal Watershed

    Science.gov (United States)

    Bair, R.; Segura, C.; Lorion, C.

    2015-12-01

    Large wood (LW) additions are often part of fish habitat restorations in the PNW where historic forest clear-cutting limited natural wood recruitment. These efforts' relative successes are rarely reported in terms of ecological significance to different life stages of fish. Understanding the effectiveness of LW additions will contribute to successfully managing forest land. In this study we quantify the geomorphic change of a restoration project involving LW additions to three alluvial reaches in Mill Creek, OR. The reaches are 110-130m in plane-bed morphology and drain 2-16km2. We quantify the change in available habitat to different life stages of coho salmon in terms of velocity (v), shear stress (t), flow depth, and grain size distributions (GSD) considering existing thresholds in the literature for acceptable habitat. Flow conditions before and after LW additions are assessed using a 2D hydrodynamic model (FaSTMECH). Model inputs include detailed channel topography, discharge, and surface GSD. The spatial-temporal variability of sediment transport was also quantified based the modeled t distributions and the GSD to document changes in the overall geomorphic regime. Initial modeling results for pre wood conditions show mean t and v values ranging between 0 and 26N/m2 and between 0 and 2.4m/s, respectively for up to bankfull flow (Qbf). The distributions of both t and v become progressively wider and peak at higher values as flow increases with the notable exception at Qbf for which the area of low velocity increases noticeably. The spatial distributions of velocity results indicates that the extent of suitable habitat for adult coho decreased by 18% between flows 30 and 55% of BF. However the area of suitable habitat increased by 15% between 0.55Qbf and Qbf as the flow spreads from the channel into the floodplain. We expect the LW will enhance floodplain connectivity and thus available habitat by creating additional areas of low v during winter flows.

  17. The Long-Term Effects of Large Wood Placement on Salmonid Habitat in East Fork Mill Creek, Redwood National and State Park, California

    Science.gov (United States)

    Rodriguez, D. L.; Stubblefield, A. P.

    2017-12-01

    The conservation and recovery of anadromous salmonids (Oncorhynchus sp.) depend on stream restoration and protection of freshwater habitats. Instream large wood dictates channel morphology, increase retention of terrestrial inputs such as organic matter, nutrients and sediment, and enhances the quality of fish habitat. Historic land use/land cover changes have resulted in aquatic systems devoid of this component. Restoration by placement of large wood jams is intended to restore physical and biological processes. An important question for scientists and managers, in addition to the initial effectiveness of restoration, is the persistence and fate of this type of project. In this study we compare channel change and large wood attributes on the East Fork of Mill Creek, a tributary of the Smith River in northern California, eight years after a major instream wood placement effort took place. Our results are compared with previously published data from before and one year after the restoration. Preliminary results suggest the dramatic increase in spawning gravel abundance and large wood accumulation observed in the earlier study have persisted. From 2008 to 2016 a reduction in median sediment size, ranging from 103-136 percent, has been observed in a majority of the sites. The sites have continued to grow in size and influence by racking floating wood from upstream and destabilizing proximate banks of riparian alder, increasing both instream large wood volume (5-196 %) and floodplain connectivity. Preliminary results also show a decrease in residual pool depth and an increase in pool length which may be attributed to floodplain connectivity. Changes to the following attributes are evaluated: 1) wood loading (total site wood volume, total wood volume in active channel, and wood piece count); 2) percent pool cover by large wood; 3) residual pool depth; 4) upstream sediment aggradation; 5) floodplain connectivity; and 6) mean sediment size directly above and below large

  18. Effect of natural ageing on volume stability of MSW and wood waste incineration residues

    International Nuclear Information System (INIS)

    Gori, Manuela; Bergfeldt, Britta; Reichelt, Jürgen; Sirini, Piero

    2013-01-01

    Highlights: ► Natural weathering on BA from MSW and wood waste incineration was evaluated. ► Type of mineral phases, pH and volume stability were considered. ► Weathering reactions effect in improved stability of the materials. - Abstract: This paper presents the results of a study on the effect of natural weathering on volume stability of bottom ash (BA) from municipal solid waste (MSW) and wood waste incineration. BA samples were taken at different steps of treatment (fresh, 4 weeks and 12 weeks aged) and then characterised for their chemical and mineralogical composition and for volume stability by means of the mineralogical test method (M HMVA-StB), which is part of the German quality control system for using aggregates in road construction (TL Gestein-StB 04). Changes of mineralogical composition with the proceeding of the weathering treatment were also monitored by leaching tests. At the end of the 12 weeks of treatment, almost all the considered samples resulted to be usable without restrictions in road construction with reference to the test parameter volume stability

  19. 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

  20. Wood ash treatment, a cost-effective way to deactivate tannins in Acacia cyanophylla Lindl. foliage and to improve digestion by Barbarine sheep

    Energy Technology Data Exchange (ETDEWEB)

    Ben Salem, H. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)]. E-mail: bensalem.hichem@iresa.agrinet.tn; Abidi, S. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia); Ecole Superieure d' Agriculture de Mateur, Mateur (Tunisia); Makkar, H.P.S. [Animal Production and Health Section, Joint FAO/IAEA Division, International Atomic Energy Agency, Vienna (Austria); Nefzaoui, A. [Institut National de la Recherche Agronomique de Tunisie (INRAT), Laboratoire des Productions Animales et Fourrageres, Ariana (Tunisia)

    2005-08-19

    Three in vitro experiments and one in vivo experiment were carried out to study the effect of wood ash sources (6 L wood ash solution/kg fresh plant leaves) and levels and treatment duration on the nutritive value of acacia leaves. In Experiment 1, samples of fresh (F), dried (D), or dried and ground (DG) acacia were soaked for 6 h in water or acacia wood ash solution (120 g of wood ash dry matter/L of water). Soaking acacia in water decreased total extractable phenols (TP), total extractable tannins (TT) and extractable condensed tannins (CT). Wood ash treatment led to a further decrease of these phenolic compounds and was highest with DG acacia. Experiment 2 investigated different levels of acacia wood ash (0, 120, 180 and 240 g wood ash dry matter/L of water) and treatment duration (1, 2 and 3 days). The higher the level of wood ash, the lower proportion of TP and CT in acacia was noted. In Experiment 3, two sources of wood ash (i.e., acacia and Aleppo pine) and the same solution of each source of wood ash were used eight times. The two sources of wood ash had similar deactivating effect on TP and CT. The rate of decrease of TP and CT was highest when the same wood ash solution was used four consecutive times and decreased progressively thereafter. In these three experiments, water and wood ash treatment reduced organic matter and crude protein content but substantially increased the neutral detergent fibre (NDFom) content of treated acacia. In the fourth experiment, we treated acacia with acacia wood ash (180 g/L of water for 2 days) and the same solution was used five times. Treated and untreated acacia were air-dried and fed ad libitum to two groups, each of four Barbarine rams together with 300 g of concentrate. Wood ash treatment did not affect intake and OM digestibility of the diet but increased crude protein and NDFom digestibility (P < 0.05). Feeding untreated acacia resulted in negative N balances but with wood ash treatment, N balance was positive

  1. Effect of compatibilization and reprocessing on the isothermal crystallization kinetics of polypropylene/wood flour composites

    Directory of Open Access Journals (Sweden)

    Arieny Rodrigues

    2013-01-01

    Full Text Available Numerous studies have focused on polymer mixtures aimed at the potential applications of these materials. This work analyzed the effect of polymer reprocessing and the type and concentration of compatibilizer on the isothermal crystallization kinetics of polypropylene/wood flour composites. The composites, which were polypropylene grafted with acrylic acid (PP-g-AA and maleic anhydride (PP-g-MA, were processed in a twin screw extruder with and without compatibilizer. Reprocessed polypropylene reached complete crystallization in less time than the composites with virgin polypropylene. The addition of wood flour to the composites did not change the kinetics significantly compared to that of the pure polymers, but the compatibilizers did, particularly PP-g-AA. The nucleation exponent (n and crystallization rate (K were calculated from Avrami plots. The values of n ranged from 2 to 3, indicating instantaneous to sporadic nucleation. The crystallization half-time of reprocessed polypropylene was shorter than that of virgin polypropylene and of the compositions containing PP-g-AA compatibilizer. The activation energy of crystallization and the equilibrium melting temperature were calculated, respectively, from Arrhenius and Hoffman-Weeks plots. Both of these parameters showed lower values in the composites, particularly in the ones containing compatibilizers.

  2. 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%.

  3. Effects of wood ash on soil solution and chemistry of leaves in a beech stand

    International Nuclear Information System (INIS)

    Tothova, Slavka

    2005-01-01

    The short-term effects of wood ash fertilization on chemistry of soil solution and leaves were investigated in 4-year-old beech stand (Fagus sylvatica L.) on dystric cambisol in Central Spis. Four plots - the control plot and three plots with different ash treatments (different dose, date and method of application) were established. Plate lysimeters were installed under the upper layer of soil in depth 2 cm and 20 cm on the control plot and plot P1 with addition of wood ash 5 t/ha on the whole surface. Soil solution was collected in May - October 2002 every two weeks. Composite samples, which represent a one - month period, were analysed for pH, K, Ca, Mg, and NO 3 - . The leaves were collected 4 or 10 months after the treatment and analysed on Ca, K, Mg, P, S, N and heavy metals Cd, Pb, Cr and Hg. In the ash treatment the content of macronutrient increased (mainly K, Ca). Addition of ash did not increase of the content heavy metal in leaves

  4. R W Wood's Experiment Done Right - A Laboratory Demonstration of the Greenhouse Effect

    Science.gov (United States)

    Halpern, J. B.

    2016-12-01

    It would not be exaggerating to say that R. W. Wood was the most respected experimental optical physicist of his time. Thus the null result of his attempt to demonstrate the greenhouse effect by comparing temperature rise in illuminated cylinders with glass or rock salt windows has echoed down through the years in climate science discussions both on the professional and public levels1. Today the web is full of videos purporting to demonstrate the greenhouse effect, but careful examination shows that they simply demonstrate heating via absorption of IR or NIR light by CO2. These experiments miss that the greenhouse effect is a result of the temperature difference between the surface and the upper troposphere as a result of which radiation from greenhouse molecules slows as the level rises. The average distance a photon emitted from a vibrationally excited CO2 molecule is about 10 m at the surface, increasing with altitude until at about 8 km the mean free path allows for radiation to space. Increasing CO2 concentrations raises this level to a higher one, which is colder, and at which the rate of radiation to space decreases. Emitting the same amount of radiation to space as before requires heating the entire system including the surface. To model the greenhouse effect we have used a 22 L bulb with a capsule heater in the center. The temperature near the heater (the surface) or above it can be monitored using a thermocouple and the CO2 mixing ratio determined using a NDIR sensor. By controlling the CO2 concentration in the bulb, the mean free path of re-radiated photons from CO2 can be controlled so that it much smaller than the bulb's diameter. We have measure rises in temperature both near the heater and at a distance from it as CO2is introduced, demonstrating the greenhouse effect. 1. R.W. Wood, London, Edinborough and Dublin Philosophical Magazine , 1909, 17, p319-320 also http://www.wmconnolley.org.uk/sci/wood_rw.1909.html

  5. Biosorbents prepared from wood particles treated with anionic polymer and iron salt: Effect of particle size on phosphate adsorption

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min

    2008-01-01

    Biomass-based adsorbents have been widely studied as a cost-effective and environmentally-benign means to remove pollutants and nutrients from water. A two-stage treatment of aspen wood particles with solutions of carboxymethyl cellulose (CMC) and ferrous chloride afforded a biosorbent that was effective in removing phosphate from test solutions. FTIR spectroscopy of...

  6. 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.

  7. Wood density variation and tree ring distinctness in Gmelina arborea trees by x-ray densitometry

    Directory of Open Access Journals (Sweden)

    Roger Moya

    2009-03-01

    Full Text Available Due to its relationship with other properties, wood density is the main wood quality parameter. Modern, accuratemethods such as X-ray densitometry - are applied to determine the spatial distribution of density in wood sections and to evaluatewood quality. The objectives of this study were to determinate the influence of growing conditions on wood density variation andtree ring demarcation of gmelina trees from fast growing plantations in Costa Rica. The wood density was determined by X-raydensitometry method. Wood samples were cut from gmelina trees and were exposed to low X-rays. The radiographic films weredeveloped and scanned using a 256 gray scale with 1000 dpi resolution and the wood density was determined by CRAD and CERDsoftware. The results showed tree-ring boundaries were distinctly delimited in trees growing in site with rainfall lower than 2510 mm/year. It was demonstrated that tree age, climatic conditions and management of plantation affects wood density and its variability. Thespecific effect of variables on wood density was quantified by for multiple regression method. It was determined that tree yearexplained 25.8% of the total variation of density and 19.9% were caused by climatic condition where the tree growing. Wood densitywas less affected by the intensity of forest management with 5.9% of total variation.

  8. EFFECTS OF LEACHING MEDIUM ON LEACHABILITY OF WOOD PRESERVING N'N-HYDROXYNAPTHALIMIDE (NHA)

    OpenAIRE

    Evren Terzi,; Dilek Dogu,; Feyza Kurt,; S. Nami Kartal,; Frederick Green

    2012-01-01

    Laboratory leaching test procedures usually call for the use of distilled or deionized water; however, treated wood is generally exposed to different types of water, soil, and weather conditions. Thus, factors such as salinity, hardness, pH, temperature etc. might be important in the release of different amounts of biocide compounds. This study evaluates the release of the sodium salt of the calcium precipitating and wood preserving agent N’N-hydroxynapthalimide (NHA) from treated wood specim...

  9. Determination of Effective Criteria for Location Selection of Kiln Wood Drying Plants by AHP Technique

    Directory of Open Access Journals (Sweden)

    Rahim Mohebbi

    2011-12-01

    Full Text Available This study was aimed at determining the effective criteria for location selection of wood drying plants in Iran. For this purpose, after review and field visit of the industries, 35 key indicators were identified. These criteria were divided into five major groups as: materials, infrastructure, technical, economical and instructional indices. The priority rates of these criteria and sub-criteria were evaluated by AHP technique. The results indicated that among 35 effective sub-criteria in location selection of the plants, the sub-criteria of quality of raw materials(0.152, purchasing raw materials, land cost, profitability, reliability of supply, and sales had the highest priorities, which were rated as 0.118, 0.105, 0.067, 0.061 and 0.057, respectively

  10. 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.

  11. A Study on the Effect of Plasma Treatment for Waste Wood Biocomposites

    Directory of Open Access Journals (Sweden)

    MiMi Kim

    2013-01-01

    Full Text Available The surface modification of wood powder by atmospheric pressure plasma treatment was investigated. The composites were manufactured using wood powder and polypropylene (wood powder: polypropylene = 55 wt% : 45 wt%. Atmospheric pressure plasma treatment was applied under the condition of 3 KV, 17±1 KHz, 2 g/min. Helium was used as the carrier gas and hexamethyl-disiloxane (HMDSO as the monomer to modify the surface property of the waste wood biocomposites by plasma polymerization. The tensile strengths of untreated waste wood powder (W3 and single species wood powder (S3 were about 18.5 MPa and 21.5 MPa while those of plasma treated waste wood powder (PW3 and plasma treated single species wood powder (PS3 were about 21.2 MPa and 23.4 MPa, respectively. Tensile strengths of W3 and S3 were improved by 14.6% and 8.8%, respectively. From the analyses of mechanical properties and morphology, we conclude that the interfacial bonding of polypropylene and wood powder can be improved by atmospheric pressure plasma treatment.

  12. 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 (...

  13. Coupling effect of waste automotive engine oil in the preparation of wood reinforced LDPE plastic composites for panels

    Directory of Open Access Journals (Sweden)

    Maame Adwoa Bentumah Animpong

    2017-12-01

    Full Text Available We demonstrated the formulation of wood plastic composite (WPC materials with flexural strength of 13.69 ± 0.09 MPa for applications in outdoor fencing using municipal waste precursors like low density polyethylene (LDPE plastics (54.0 wt. %, sawn wood dust with particle size between 64 and 500 μm derived from variable hardwood species (36.0 wt. % and used automotive engine oil (10 wt. %. The WPC panels were prepared by pre-compounding, extruding at a screw auger torque of 79.8 Nm and pressing through a rectangular mould of dimension 132 mm × 37 mm × 5 mm at temperature 150 °C. The efficacy of black waste oil, as a coupling agent, was demonstrated by the absence of voids and pull-outs on microscopic examination using scanning electron microscopy. No hazardous substances were exhaled during thermo-gravimetric mass spectrometry analysis. The percentage crystallinity of the LDPE in the as-prepared material determined by differential scanning calorimetry was 11.3%. Keywords: Wood plastic composites, Low density polyethylene, Wood dust, Physical, Thermal and mechanical properties

  14. Predictive Modeling of Black Spruce (Picea mariana (Mill. B.S.P. Wood Density Using Stand Structure Variables Derived from Airborne LiDAR Data in Boreal Forests of Ontario

    Directory of Open Access Journals (Sweden)

    Bharat Pokharel

    2016-12-01

    Full Text Available Our objective was to model the average wood density in black spruce trees in representative stands across a boreal forest landscape based on relationships with predictor variables extracted from airborne light detection and ranging (LiDAR point cloud data. Increment core samples were collected from dominant or co-dominant black spruce trees in a network of 400 m2 plots distributed among forest stands representing the full range of species composition and stand development across a 1,231,707 ha forest management unit in northeastern Ontario, Canada. Wood quality data were generated from optical microscopy, image analysis, X-ray densitometry and diffractometry as employed in SilviScan™. Each increment core was associated with a set of field measurements at the plot level as well as a suite of LiDAR-derived variables calculated on a 20 × 20 m raster from a wall-to-wall coverage at a resolution of ~1 point m−2. We used a multiple linear regression approach to identify important predictor variables and describe relationships between stand structure and wood density for average black spruce trees in the stands we observed. A hierarchical classification model was then fitted using random forests to make spatial predictions of mean wood density for average trees in black spruce stands. The model explained 39 percent of the variance in the response variable, with an estimated root mean square error of 38.8 (kg·m−3. Among the predictor variables, P20 (second decile LiDAR height in m and quadratic mean diameter were most important. Other predictors describing canopy depth and cover were of secondary importance and differed according to the modeling approach. LiDAR-derived variables appear to capture differences in stand structure that reflect different constraints on growth rates, determining the proportion of thin-walled earlywood cells in black spruce stems, and ultimately influencing the pattern of variation in important wood quality attributes

  15. Effect of metallurgical variables on void swelling

    International Nuclear Information System (INIS)

    Johnston, W.G.; Lauritzen, T.; Rosolowski, J.H.; Turkalo, A.M.

    1976-01-01

    The mechanism of void swelling is reviewed briefly and the anticipated effects of metallurgical variables are described. Experimental results showing the effects of metallurgical variables are reviewed, most of the work being done by simulation methods employing charged particle bombardments to simulate reactor damage. Although the early emphasis was on structural variables such as grain size, cold work and precipitates to control swelling, it now seems that the practical reduction of swelling will be achieved by modifying alloy composition. Void swelling is strongly influenced by the relative amounts of Fe, Cr, and Ni in an alloy; the amount of swelling can be varied by three orders of magnitude by changing the relative amounts of the three elements in an austenitic ternary alloy. The effect of composition on swelling of a simple ferritic alloy will also be described. The swelling of a simple austenitic alloy of Fe, Cr, and Ni can be reduced by certain minor element additions. The most effective swelling inhibitors are Si, Ti, Zr, and Nb, and combinations of Si and Ti are synergetic. Swelling reductions of two orders of magnitude have been achieved with combined additions. Predictions of swelling in commercial solid solution alloys are made on the basis of the present knowledge of the effects of major composition and minor element additions. The predictions agree with experimental results. For more complex commercial alloys, predictions are made for the effects on swelling of heat treatments that cause changes in matrix composition. In some cases, heat treatment is expected to change the peak swelling by more than a factor of ten, and to shift the peak swelling temperature by almost 100 0 C. Sensitivity of swelling to detailed matrix composition places emphasis on the need for developing understanding of the stability of structure and local composition in an irradiation environment

  16. Biomimetic studies of wood decay: Simulating the effect of low molecular weight compounds and fungal enzymes

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Howell, Caitlin; Jellison, Jody

    The effect of FeCl3 (Fe3+), hydrogen peroxide (H2O2), a low molecular weight compound (2,3- Dihydroxybenzoic acid), and oxalic acid on wood were tested in a study designed to mimic wood degradation by brown rot fungi. Previous studies suggest that these components are involved in the early stages...... 50 ml of 40 mM acetate buffer (pH 4.5), white pine wood powder and varying combinations of the chemicals previously mentioned. Changes in cellulose crystallinity were analyzed by X-ray diffraction using a ¿-2¿ scan. Findings suggest that iron, H2O2, chelators and oxalic acid may affect over all...

  17. 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.

  18. The effects of habitat degradation on metacommunity structure of wood-inhabiting fungi in European beech forests

    DEFF Research Database (Denmark)

    Halme, Panu; Ódor, Péter; Christensen, Morten

    2013-01-01

    Intensive forest management creates habitat degradation by reducing the variation of forest stands in general, and by removing old trees and dead wood in particular. Non-intervention forest reserves are commonly believed to be the most efficient tool to counteract the negative effects...... with different management histories. For this purpose, we used a large data set of wood-inhabiting fungi collected from dead beech trees in European beech-dominated forest reserves. The structure of fungal assemblages showed high beta diversity, while nestedness and similarity was low. During the decomposition...... extirpated specialized species from the local species pools in managed sites, and resulted in more homogeneous communities in managed sites. It is alarming that community structure is affected the most in the latest decay stages where the decay process turns the dead wood into litter, and which is thus...

  19. 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...

  20. Effects of triphenyltin on growth and development of the wood frog (Lithobates sylvaticus)

    Energy Technology Data Exchange (ETDEWEB)

    Higley, Eric; Tompsett, Amber R. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); Giesy, John P. [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK (Canada); Zoology Department, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI (United States); Department of Biology and Chemistry, and State Key Laboratory for Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region (Hong Kong); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing (China); Hecker, Markus [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada); School of the Environment and Sustainability, University of Saskatchewan, Saskatoon, SK (Canada); Wiseman, Steve, E-mail: steve.wiseman@usask.ca [Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada S7N 5B3 (Canada)

    2013-11-15

    Highlights: •Wood frogs (Lithobates sylvaticus) were exposed to 0.1, 1.0, or 5.0 μg TPT/L. •Environmental concentrations of TPT affected survival and development of wood frogs. •Mortality of larvae was 100% after 9 days of exposure to 5.0 μg TPT/L. •Effects on growth and development might have been due to effects on lipid metabolism. -- Abstract: Exposure to contaminants in the environment has been suggested as a contributing cause of ongoing declines in populations of amphibians reported in certain locations around the world. In the current study, responses of the wood frog (Lithobates sylvaticus) to exposure to triphenyltin (TPT), a commonly used fungicide, during the larval period were characterized. Exposure of L. sylvaticus to 0.1, 1.0, or 5.0 μg TPT/L significantly affected survival, growth, days to metamorphosis (DTM), and abundances of transcripts of genes of interest. After seven days of exposure there were no significant effects on survival, but masses and snout-ventral length (SVL) of larvae exposed to 5.0 μg TPT/L were significantly lesser than controls. Mortality of larvae after exposure to 5.0 μg TPT/L was 100% nine days after initiation of the experiment. Larvae exposed to 0.1 or 1.0 μg TPT/L were allowed to grow for 100 days or until they reached metamorphic climax, whichever occurred earlier. Mortality of wood frogs exposed to 1.0 μg TPT/L was 80%. The LC{sub 20} or LC{sub 50} after 100 days of exposure was 0.12 or 0.34 μg TPT/L, respectively. However, DTM of larvae that survived exposure to 1.0 μg TPT/L was significantly less than that of controls. Abundances of transcripts of retinoid-X-receptor (rxr) and perixosomal proliferation receptor gamma (pparγ) were significantly lesser in larvae exposed to either concentration of TPT for seven days. Also, abundances of transcripts of stearoyl-CoA desaturase-1 (scd1), fatty acid synthase (fas), lipoprotein lipase (lpl), and β-hydroxybutyrate dehydrogenase (β-hb-m) were lesser in

  1. Effects of triphenyltin on growth and development of the wood frog (Lithobates sylvaticus)

    International Nuclear Information System (INIS)

    Higley, Eric; Tompsett, Amber R.; Giesy, John P.; Hecker, Markus; Wiseman, Steve

    2013-01-01

    Highlights: •Wood frogs (Lithobates sylvaticus) were exposed to 0.1, 1.0, or 5.0 μg TPT/L. •Environmental concentrations of TPT affected survival and development of wood frogs. •Mortality of larvae was 100% after 9 days of exposure to 5.0 μg TPT/L. •Effects on growth and development might have been due to effects on lipid metabolism. -- Abstract: Exposure to contaminants in the environment has been suggested as a contributing cause of ongoing declines in populations of amphibians reported in certain locations around the world. In the current study, responses of the wood frog (Lithobates sylvaticus) to exposure to triphenyltin (TPT), a commonly used fungicide, during the larval period were characterized. Exposure of L. sylvaticus to 0.1, 1.0, or 5.0 μg TPT/L significantly affected survival, growth, days to metamorphosis (DTM), and abundances of transcripts of genes of interest. After seven days of exposure there were no significant effects on survival, but masses and snout-ventral length (SVL) of larvae exposed to 5.0 μg TPT/L were significantly lesser than controls. Mortality of larvae after exposure to 5.0 μg TPT/L was 100% nine days after initiation of the experiment. Larvae exposed to 0.1 or 1.0 μg TPT/L were allowed to grow for 100 days or until they reached metamorphic climax, whichever occurred earlier. Mortality of wood frogs exposed to 1.0 μg TPT/L was 80%. The LC 20 or LC 50 after 100 days of exposure was 0.12 or 0.34 μg TPT/L, respectively. However, DTM of larvae that survived exposure to 1.0 μg TPT/L was significantly less than that of controls. Abundances of transcripts of retinoid-X-receptor (rxr) and perixosomal proliferation receptor gamma (pparγ) were significantly lesser in larvae exposed to either concentration of TPT for seven days. Also, abundances of transcripts of stearoyl-CoA desaturase-1 (scd1), fatty acid synthase (fas), lipoprotein lipase (lpl), and β-hydroxybutyrate dehydrogenase (β-hb-m) were lesser in larvae exposed

  2. Formulation of a correlated variables methodology for assessment of continuous gas resources with an application to the Wood ford play, Arkoma Basin, eastern Oklahoma

    Energy Technology Data Exchange (ETDEWEB)

    Olea, R. A.; Houseknecht, D. W.; Garrity, C. P.; Cook, T. A.

    2011-07-01

    Shale gas is a form of continuous unconventional hydrocarbon accumulation whose resource estimation is unfeasible through the inference of pore volume. Under these circumstances, the usual approach is to base the assessment on well productivity through estimated ultimate recovery (EUR). Unconventional resource assessments that consider uncertainty are typically done by applying analytical procedures based on classical statistics theory that ignores geographical location, does not take into account spatial correlation, and assumes independence of EUR from other variables that may enter into the modeling. We formulate a new, more comprehensive approach based on sequential simulation to test methodologies known to be capable of more fully utilizing the data and overcoming unrealistic simplifications. Theoretical requirements demand modeling of EUR as areal density instead of well EUR. The new experimental methodology is illustrated by evaluating a gas play in the Wood ford Shale in the Arkoma Basin of Oklahoma. Differently from previous assessments, we used net thickness and vitrinite reflectance as secondary variables correlated to cell EUR. In addition to the traditional probability distribution for undiscovered resources, the new methodology provides maps of EUR density and maps with probabilities to reach any given cell EUR, which are useful to visualize geographical variations in prospectivity. (Author) 21 refs.

  3. Wood Export and Deposition Dynamics in Mountain Watersheds

    Science.gov (United States)

    Senter, Anne Elizabeth

    using decision tree analyses. Digital imagery collected via kite-blimp was mosaicked into a geographic information system and all resolvable wood pieces greater then 2.5 cm in one dimension were delineated and categorized into piece count density classes. Visual imagery was also key in identifying two river corridor terrains: bedrock outcrops and cobble-boulder-vegetation patches. A conceptual model framed an investigation into how topographic variability and structural elements might influence observed wood deposition dynamics. Forage ratio test results that quantified wood piece utilization versus interval availability revealed that high-density wood deposition patterns were most significantly co-located with five discrete bedrock outcrops that dominated small portions of the river corridor in high flow conditions. Topographic variations and cobble-boulder-vegetation patches were found to be subordinate factors in wood deposition patterns. Bedrock outcrops with specific structural components were the primary depositional environments that acted as floodplain extents for coarse wood deposition, with mechanisms such as topographic steering, eddying, trapping, stranding, backwater effects, and lateral roughness features inferred to be responsible for observed wood deposition patterns.

  4. Ecology of coarse wood decomposition by the saprotrophic fungus Fomes fomentarius.

    Science.gov (United States)

    Větrovský, Tomáš; Voříšková, Jana; Snajdr, Jaroslav; Gabriel, Jiří; Baldrian, Petr

    2011-07-01

    Saprotrophic wood-inhabiting basidiomycetes are the most important decomposers of lignin and cellulose in dead wood and as such they attracted considerable attention. The aims of this work were to quantify the activity and spatial distribution of extracellular enzymes in coarse wood colonised by the white-rot basidiomycete Fomes fomentarius and in adjacent fruitbodies of the fungus and to analyse the diversity of the fungal and bacterial community in a fungus-colonised wood and its potential effect on enzyme production by F. fomentarius. Fungus-colonised wood and fruitbodies were collected in low management intensity forests in the Czech Republic. There were significant differences in enzyme production by F. fomentarius between Betula pendula and Fagus sylvatica wood, the activity of cellulose and xylan-degrading enzymes was significantly higher in beech wood than in birch wood. Spatial analysis of a sample B. pendula log segment proved that F. fomentarius was the single fungal representative found in the log. There was a high level of spatial variability in the amount of fungal biomass detected, but no effects on enzyme activities were observed. Samples from the fruiting body showed high β-glucosidase and chitinase activities compared to wood samples. Significantly higher levels of xylanase and cellobiohydrolase were found in samples located near the fruitbody (proximal), and higher laccase and Mn-peroxidase activities were found in the distal ones. The microbial community in wood was dominated by the fungus (fungal to bacterial DNA ratio of 62-111). Bacterial abundance composition was lower in proximal than distal parts of wood by a factor of 24. These results show a significant level of spatial heterogeneity in coarse wood. One of the explanations may be the successive colonization of wood by the fungus: due to differential enzyme production, the rates of biodegradation of coarse wood are also spatially inhomogeneous.

  5. ASSESSMENT OF THE MOISTURE EFFECT ON GASEOUS PRODUCTS OF SELF-HEATING OF WOOD CHIPS

    Directory of Open Access Journals (Sweden)

    Hana VĚŽNÍKOVÁ

    2017-12-01

    Full Text Available Biofuels are stored in large quantities and may be susceptible to self-ignition. The possible methods of indication of temperature increase include the analysis of the gaseous products of heating where concentrations of certain gases may increase with increasing temperature. Gas release is also affected by the moisture of the material given that the moisture level changes surface accessibility for oxygen on the one side and serves as a catalyst of the oxidation reactions on the other. The present project analysed the effect of temperature and moisture on gaseous products of heating of wood chips, one of frequently used biofuels, with the aim to determine a suitable gaseous indicator of beginning self-ignition.

  6. Effect Of Wood-Based Biochar And Sewage Sludge Amendments For Soil Phosphorus Availability

    Directory of Open Access Journals (Sweden)

    Frišták Vladimír

    2015-06-01

    Full Text Available This study investigated the effects of two biochars (pyrolysed wood chips and garden clippings on phosphorus (P availability in a heavy-metal contaminated soil poor in phosphorus. Short-term 14-days incubation experiments were conducted to study how applications of biochars at different rates (1 and 5 % in combination with (1:1 and without dried sewage sludge from a municipal waste water treatment plant (WWTP affected the content of soil extractable P. For P-availability analyses deionized water, calcium acetate lactate (CAL, Mehlich 3 and Olsen extraction protocols were applied. In addition, the content of total and mobile forms of potentially toxic heavy metals (PTHM was studied. Application of both biochars caused a significant decrease of PTHM available forms in sewage sludge amended soil samples. The concentration of total and available P increased with higher biochar and sewage sludge application rates.

  7. Guide for minimizing the effect of preservative-treated wood on sensitive environments

    Science.gov (United States)

    Stan T. Lebow; Michael Tippie

    2001-01-01

    Preservative-treated wood is often used for construction of highway and foot bridges, wetland boardwalks, and other structures in or over water or sensitive environments. In these applications it is important that release of preservative from the wood into the environment is minimized. This publication addresses this concern by describing the various types of pressure-...

  8. Effect of Extraction Conditions on the Antioxidant Activity of Olive Wood Extracts

    NARCIS (Netherlands)

    Pérez-Bonilla, M.; Salido, S.; Sánchez, A.; Beek, van T.A.; Altarejos, J.

    2013-01-01

    An investigation to optimize the extraction yield and the radical scavenging activity from the agricultural by-product olive tree wood (Olea europaea L., cultivar Picual) using six different extraction protocols was carried out. Four olive wood samples from different geographical origin, and

  9. Effects of riparian buffer width on wood loading in headwater streams after repeated forest thinning

    Science.gov (United States)

    Julia I. Burton; Deanna H. Olson; Klaus J. Puettmann

    2016-01-01

    Forested riparian buffer zones are used in conjunction with upland forest management, in part, to provide for the recruitment for large wood to streams. Small headwater streams account for the majority of stream networks in many forested regions. Yet, our understanding of how riparian buffer width influences wood dynamics in headwater streams is relatively less...

  10. A 3D multilevel model of damage and strength of wood: Analysis of microstructural effects

    DEFF Research Database (Denmark)

    Qing, Hai; Mishnaevsky, Leon

    2011-01-01

    A 3D hierarchical computational model of damage and strength of wood is developed. The model takes into account the four scale microstructures of wood, including the microfibril reinforced structure at nanoscale, multilayered cell walls at microscale, hexagon-shape-tube cellular structure...

  11. Effects of species information and furniture price on consumer preferences for selected woods

    Science.gov (United States)

    Matthew Bumgardner; David Nicholls; Geoffrey Donovan

    2007-01-01

    Changing consumer tastes and species availability are influencing the design and manufacture of hardwood products. In addition, the globalization of wood product markets is exposing U.S. consumers to new species. This research evaluates consumer preferences for six domestic wood species--three from the eastern United States and three from the western United States. The...

  12. Peat and the greenhouse effect - Comparison of peat with coal, oil, natural gas and wood

    International Nuclear Information System (INIS)

    Hillebrand, K.

    1993-01-01

    The earth's climate is effected both by natural factors and human activities. So called greenhouse gas emissions increase the increment of the temperature of the air nearby the earth's surface, due to which the social changes can be large. The increment of greenhouse gas concentration in the atmosphere is due to increasing energy consumption. About 50 % of the climatic changes are caused by increase of the CO 2 concentration in the atmosphere. Other gases, formed in the energy production, intensifying the greenhouse effect are methane and nitrous oxide. The effect of greenhouse gases is based on their ability to absorb infrared radiation coming from the earth. This presentation discusses some of the greenhouse effect caused by some peat production and utilization chains in comparison with corresponding effects of coal, oil, natural gas and wood. The instantaneous greenhouse effects and the cumulative effects of the emissions of the gases (CO 2 , CH 4 and N 2 O) during a time period has been reviewed. The greenhouse effect has been calculated as CO 2 - equivalents. (5 figs.)

  13. 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...

  14. 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

  15. 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...

  16. Effects of particle size on the morphology and waterand thermo-resistance of washed cottonseed meal-based wood adhesives

    Science.gov (United States)

    Water wash of cottonseed meal is more cost-efficient and environment-friendly than the protein isolation which involves alkaline extraction and acidic precipitation. Thus, water-washed cottonseed meal (WCSM) is more promising as biobased wood adhesives. In this work, we examined the effects of the p...

  17. 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.

  18. 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...

  19. Variable effects of temperature on insect herbivory

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2014-05-01

    Full Text Available Rising temperatures can influence the top-down control of plant biomass by increasing herbivore metabolic demands. Unfortunately, we know relatively little about the effects of temperature on herbivory rates for most insect herbivores in a given community. Evolutionary history, adaptation to local environments, and dietary factors may lead to variable thermal response curves across different species. Here we characterized the effect of temperature on herbivory rates for 21 herbivore-plant pairs, encompassing 14 herbivore and 12 plant species. We show that overall consumption rates increase with temperature between 20 and 30 °C but do not increase further with increasing temperature. However, there is substantial variation in thermal responses among individual herbivore-plant pairs at the highest temperatures. Over one third of the herbivore-plant pairs showed declining consumption rates at high temperatures, while an approximately equal number showed increasing consumption rates. Such variation existed even within herbivore species, as some species exhibited idiosyncratic thermal response curves on different host plants. Thus, rising temperatures, particularly with respect to climate change, may have highly variable effects on plant-herbivore interactions and, ultimately, top-down control of plant biomass.

  20. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, B.; Heinemeier, J.

    2013-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fish bones, shells, human bones, or food crusts on pottery from sites near rivers or lakes. The reservoir age in hardwater rivers can be up to several thousand years and may be highly variable. Accurate 14C dating of f...... that can also be expected for the past. This knowledge will be applied to the dating of food crusts on pottery from the Mesolithic sites Kayhude at the Alster River and Schlamersdorf at the Trave River, both in Schleswig-Holstein, northern Germany....

  1. Wood ash and lime. Effects on uptake of nutrients and heavy metals in bilberries

    International Nuclear Information System (INIS)

    Nilsson, Torbjoern; Eriksson, H.M.

    1998-01-01

    Ten km north of Uppsala in eastern Sweden a field plot (2x2 m) experiment, with different ash and lime treatments, was established in June 1993 in a 70-year old mixed stand of Norway spruce and Scots pine on a sandy soil. The experiment included twelve treatments and one control, all with four replicates. The treatments were; a well-combusted loose wood ash, well-hardened ash granules, hardened and then crushed and sieved mixed ash, a mixture of hardened ash and lime, hardened wood ash and finally, lime. The normal dose was 4 tons per hectare. Two and thirteen months after treatment, bilberries were sampled. Bilberries sampled two months after treatment were analyzed for Ca, Mg, K, P, Al, Mn, Cd, Cu, Pb and Zn for nine treatments. Two months after treatment, the variation in the contents of different elements was very large, especially for K, P, Mn and Zn. Bilberries in the control had, on an average, lower contents of Ca, Mg, K and Cu than bilberries from the treated plots. Contents of Zn and Cd were, on an average, highest in the control plots. However, no significant differences between treatments were found. Thirteen months after treatment, the variation in content of all the heavy metals analyzed had decreased as well as the content of Pb and Zn. However, the contents of Cd and Cu had increased somewhat. No significant differences between treatments were found. It was concluded that the different treatments had a negligible effect on the content of heavy metals in bilberries the first year after treatment 122 refs, 10 figs, 15 tabs

  2. Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

    International Nuclear Information System (INIS)

    Cao Xinde; Ma, Lena Q.

    2004-01-01

    Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg -1 ) and in the fence soil (27 mg kg -1 ), resulting in enhanced As accumulation of 44 mg kg -1 in carrot and 32 mg kg -1 in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils

  3. 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...

  4. Fertilization effects of organic waste resources and bottom wood ash: results from a pot experiment

    Directory of Open Access Journals (Sweden)

    Eva Brod

    2012-12-01

    Full Text Available We conducted a pot experiment to study the fertilization effects of four N- and P-rich organic waste resources alone and in combination with K-rich bottom wood ash at two application rates (150 kg N ha–1 + 120 kg K ha–1, 300 kg N ha-1 + 240 kg K ha–1. Plant-available N was the growth-limiting factor. 48–73% of N applied with meat and bone meal (MBM and composted fish sludge (CFS was taken up in aboveground biomass, resulting in mineral fertilizer equivalents (MFE% of 53–81% for N uptake and 61–104% for yield. MFE% of MBM and CFS decreased for increasing application rates. Two industrial composts had weak N fertilization effects and are to be considered soil conditioners rather than fertilizers. Possible P and K fertilization effects of waste resources were masked by the soil’s ability to supply plant-available P and K, but effects on plant-available P and K contents in soil suggest that the waste resources may have positive effects under more nutrient-deficient conditions.

  5. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica)

    International Nuclear Information System (INIS)

    Sanzo, Domenico; Hecnar, Stephen J.

    2006-01-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2636 and 5109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted. - Road salts have toxic effects on amphibians at environmentally realistic concentrations

  6. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica)

    Energy Technology Data Exchange (ETDEWEB)

    Sanzo, Domenico [Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1 (Canada); Hecnar, Stephen J. [Department of Biology, Lakehead University, 955 Oliver Road, Thunder Bay, ON, P7B 5E1 (Canada)]. E-mail: stephen.hecnar@lakeheadu.ca

    2006-03-15

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2636 and 5109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted. - Road salts have toxic effects on amphibians at environmentally realistic concentrations.

  7. EFFECT OF CHEMICAL MODIFICATION AND HOT-PRESS DRYING ON POPLAR WOOD

    Directory of Open Access Journals (Sweden)

    Guo-Feng Wu

    2010-11-01

    Full Text Available Urea-formaldehyde prepolymer and hot-press drying were used to improve the properties of poplar wood. The wood was impregnated with the prepolymer using a pulse-dipping machine. The impregnated timbers were compressed and dried by a multilayer hot-press drying kiln. The drying rate was more rapid during the chemical modification and hot-press drying than conventional kiln-drying. In addition, the properties of timber were also enhanced obviously. When the compression rate was 28.6%, the basic density, oven dry density and air-dried density of modified wood improved 22%, 71%, and 70%, respectively. The bending strength and compressive strength parallel to grain increased 60% and 40%. The water uptake of treated wood was significantly decreased compared with the untreated wood. The FTIR analysis successfully showed that the intensity of hydroxyl and carbonyl absorption peaks decreased significantly, which was attributed to a reaction of the NHCH2OH of urea-formaldehyde prepolymer with the wood carboxyl (C=O and hydroxyl (-OH groups. The XRD results indicated that the degree of crystallinity increased from 35.09% to 36.91%. The morphologic models of chemical within wood were discovered by SEM.

  8. CREEP BEHAVIOR OF BORATE-TREATED STRANDBOARD: EFFECT OF ZINC BORATE RETENTION, WOOD SPECIES, AND LOAD LEVEL

    OpenAIRE

    Wu,Qinglin; Lee,Ong N; Cai,Zhiyong; Zhou,Dingguo

    2009-01-01

    Creep performance of zinc borate-treated strandboard from southern pine (Pinus taeda L.) and red oak (Quercus falcata) was investigated at 25(0)C temperature and 65% relative humidity. It was shown that the borate treatment had some significant effect on creep deflection of the test panels, and the effect varied with wood species. There was no significant effect of creep loading on residual bending properties of treated strandboard under the stress levels used. The four element spring-dashpot...

  9. The effects of the recent minimum temperature and water deficit increases on Pinus pinaster wood radial growth and density in southern Portugal.

    Directory of Open Access Journals (Sweden)

    Cathy Béatrice Kurz Besson

    2016-08-01

    Full Text Available Western Iberia has recently shown increasing frequency of drought conditions coupled with heatwave events, leading to exacerbated limiting climatic conditions for plant growth. It is not clear to what extent wood growth and density of agroforestry species have suffered from such changes or recent extreme climate events.To address this question, tree-ring width and density chronologies were built for a P. pinaster stand in southern Portugal and correlated with climate variables, including the minimum, mean and maximum temperatures and the number of cold days. Monthly and maximum daily precipitations were also analyzed as well as dry spells. The drought effect was assessed using the standardized precipitation-evapotranspiration (SPEI multi-scalar drought index, between 1 to 24-months. The climate-growth/density relationships were evaluated for the period 1958-2011.We show that both wood radial growth and density highly benefit from the strong decay of cold days and the increase of minimum temperature. Yet the benefits are hindered by long-term water deficit, which results in different levels of impact on wood radial growth and density. Despite of the intensification of long-term water deficit, tree-ring width appears to benefit from the minimum temperature increase, whereas the effects of long-term droughts significantly prevail on tree-ring density. Our results further highlight the dependency of the species on deep water sources after the juvenile stage. The impact of climate changes on long-term droughts and their repercussion on the shallow groundwater table and P. pinaster’s vulnerability are also discussed. This work provides relevant information for forest management in the semi-arid area of the Alentejo region of Portugal. It should ease the elaboration of mitigation strategies to assure P. pinaster’s production capacity and quality in response to more arid conditions in the near future in the region.

  10. The effects of solar variability on climate

    International Nuclear Information System (INIS)

    Hoffert, M.I.

    1990-01-01

    It has been hypothesized for at least a century that some of the observed variance in global temperature records arises from variations in solar output. Theories of solar-variability effects on climate could not be tested directly prior to satellite measurements because uncertainties in ground-based measurements of solar irradiance were larger than the solar variations themselves. Measurements by the Active Cavity Radiometer (ACRIM) onboard the Solar Max satellite and by the Earth Radiation Budget (ERB) instrument onboard Nimbus 6 are now available which indicate solar-constant variations are positively correlated with solar activity over an 11-yr solar cycle, and are of order ± 1.0 W m -2 relative to a mean solar constant of S 0 = 1,367 W m -2 , ΔS/S 0 ∼ ± 0.07%. For a typical climate sensitivity parameter of β = S 0 ∂T/∂S ∼ 100 C, the corresponding variations in radiative equilibrium temperature at the Earth's surface are ΔT e ∼ ± 0.07 C. The realized temperature variations from solar forcing, ΔT, can be significantly smaller because of thermal damping by the ocean. The author considers effects of solar variability on the observed and projected history of the global temperature record in light of this data using an upwelling-diffusion ocean model to assess the effect of ocean thermal inertia on the thermal response. The response to harmonic variations of the 11-yr sunspot cycle is of order ΔT ∼ ± 0.02 C, though the coupling between response and forcing is stronger for long-term variations in the envelope of the solar cycle which more nearly match the thermal response time of the deep ocean

  11. The Effect of Heat Treatment on the Pull-off Strength of Optionally Varnished Surfaces of Five Wood Materials

    Directory of Open Access Journals (Sweden)

    Musa Atar

    2015-09-01

    Full Text Available This study investigated the effects of heat treatment, following optional treatment with synthetic, water-based, and alkyd varnishes, on the pull-off strength of wooden materials sampled from oriental beech (Fagus orientalis L., oak (Quercus petraea Liebl., black poplar (Populus nigra L., pine (Pinus sylvestris L., and fir (Abies bornmulleriana M.. The test samples were subjected to heat treatment at temperatures of 165 °C and 175 °C for periods of 2 and 4 h with a total of 4 variations. With respect to the wood type, the samples of beech wood yielded the highest results for pull-off strength, while fir wood yielded the lowest. With respect to the varnish types, the highest pull-off strength was found in the samples of synthetic varnished beech (5,452 with a 37.2% improvement at 175 °C heat treatment for 4 h, while the lowest results were obtained in the samples of fir (0.991 with a 48.5% decrease at 175 °C heat treatment for 4 h. In conclusion, heat treatment significantly decreased the pull-off strength of the woods.

  12. THE EFFECT OF HEAT TREATMENT ON THE CHEMICAL AND COLOR CHANGE OF BLACK LOCUST (ROBINIA PSEUDOACACIA WOOD FLOUR

    Directory of Open Access Journals (Sweden)

    Yao Chen,

    2012-01-01

    Full Text Available The aim of this study was to investigate the effects of oxygen and moisture content (MC on the chemical and color changes of black locust (Robinia pseudoacacia wood during heat treatment. The wood flour was conditioned to different initial MCs and heated for 24 h at a constant temperature of 120ºC in either oxygen or nitrogen atmosphere. The pH values and chromaticity indexes were examined. Diffuse reflectance UV-Vis (DRUV and Fourier transform infrared (FTIR spectra were used to characterize the changes of chromophores upon heating. The study demonstrated that the pH values decreased after heat treatment, and it was lower when the heat treated was in oxygen than in nitrogen. The L* decreased significantly, while a* and b* increased. The total color difference ΔE* increased with increasing initial MC until a plateau was reached after 30% MC. The color change was greater in oxygen than in nitrogen. The hydroxyl groups decreased after heat treatment. The releases of acid and formation of quinoid compounds and carboxylic groups during heat treatment were confirmed. Discoloration of wood is due mainly to the condensation and oxidation reactions, which are accelerated by oxygen. Higher MCs are required to obtain the greatest color change of wood in inert atmosphere.

  13. The effects of early diagenesis on the chemical and stable carbon isotopic composition of wood

    International Nuclear Information System (INIS)

    Spiker, E.C.; Hatcher, P.G.

    1987-01-01

    Studies of modern and ancient buried wood show that there is a linear correlation between carbohydrate content and the stable carbon isotope composition as carbohydrates are preferentially degraded during early diagenesis. As the carbohydrate content decreases, the delta 13 C value of the degraded wood decreases 1 to 2 per mil, approaching the value of the residual lignin. These results indicate that carbohydrate degradation products are lost and not incorporated into the aromatic structure as lignin is selectively preserved during early diagenesis of wood. These results also indicate that attempts to quantify terrestrial inputs to modern sedimentary organic matter based on delta 13 C values should consider the possibility of a 1 to 2 per mil decrease in the delta 13 C value of degraded wood. (author)

  14. Effect of firm variables on patent price

    Directory of Open Access Journals (Sweden)

    Shyam Sreekumaran Nair

    2012-03-01

    Full Text Available In this study, using singleton patent auction price data from Ocean Tomo, LLC, we analyse the effect of firm variables on patent price. Patents owned by small firms attract higher price than patents owned by large firms, if they engage in multi-country filings. The patents owned by small firms get cited more than the patents owned by large firms. The patents owned by individual inventors attract a higher price than the patents owned by organisations when multi-country filings are not included. We believe that the lack of resources is preventing individual inventors from engaging in multi-country filings and maximising the revenue from their invention. A larger representative data should be used to replicate the results before generalising it.

  15. 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.

  16. Effects of extractives and ash on natural resistance of four woods to xylophogous termites

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2013-09-01

    Full Text Available This study tested the natural resistance of wood of four tree species to Nasutitermes corniger Motsch. xylophogous termite attack and correlate the resistance with the amount of extract and ash in the chemical composition of the tested species. The species evaluated were Anadenanthera colubrina (Vell. Brenan. var. cebil (Gris. Alts., Tabebuia aurea (Mart. Bureau., Amburana cearensis (Allem. A.C.Sm. and Eucalyptus camaldulensis Dehnh. Test samples with dimensions of 2.00 x 10.16 x 0.64 cm (radial x longitudinal x tangential were obtained at two positions (external heartwood and sapwood of each species. The samples were exposed to action of termites for 45 days in food preference assay. The content of wood extractives was obtained through the sawdust that went through sieve of 40 mesh and were retained in the 60 mesh. The natural resistance was not associated with wood extractive contents. The wood more resistant to termite attack was the Anadenanthera colubrina var. cebil in the two positions (external heartwood and sapwood and Eucalyptus camaldulensis wood presented the greatest wear. The biological resistance of wood was correlated with ash content, i.e., the species with the highest levels was the most resistant to termite attack.

  17. Methods for Mitigating the Environmental Risks Associated with Wood Preservatives

    Science.gov (United States)

    Dennis Hayward; Stan T. Lebow; Kenneth M. Brooks

    2011-01-01

    As noted in earlier chapters, the treatment of wood is both art and science. Wood is a variable material; treatment results tend to vary with the preservative and wood species and even within boards of the same species. This means that treated wood often contains a range of preservative retentions. Some pieces will have less than the desired retention, while others may...

  18. Direct and indirect drivers of instream wood in the interior Pacific Northwest, USA: decoupling climate, vegetation, disturbance, and geomorphic setting

    Directory of Open Access Journals (Sweden)

    Hough-Snee Nate

    2014-06-01

    Full Text Available Instream wood is a driver of geomorphic change in low-order streams, frequently altering morphodynamic processes. Instream wood is a frequently measured component of streams, yet it is a complex metric, responding to ecological and geomorphic forcings at a variety of scales. Here we seek to disentangle the relative importance of physical and biological processes that drive wood growth and delivery to streams across broad spatial extents. In so doing, we ask two primary questions: (1 is riparian vegetation a composite variable that captures the indirect effects of climate and disturbance on instream wood dynamics? (2 What are the direct and indirect relationships between geomorphic setting, vegetation, climate, disturbance, and instream wood dynamics? We measured riparian vegetation composition and wood frequency and volume at 720 headwater reaches within the American interior Pacific Northwest. We used ordination to identify relationships between vegetation and environmental attributes, and subsequently built a structural equation model to identify how climate and disturbance directly affect vegetation composition and how vegetation and geomorphic setting directly affect instream wood volume and frequency. We found that large wood volume and frequency are directly driven by vegetation composition and positively correlated to wildfire, elevation, stream gradient, and channel bankfull width. Indicator species at reaches with high volumes of wood were generally long-lived, conifer trees that persist for extended durations once delivered to stream habitats. Wood dynamics were also indirectly mediated by factors that shape vegetation: wildfire, precipitation, elevation, and temperature. We conclude that wood volume and frequency are driven by multiple interrelated climatic, geomorphic, and ecological variables. Vegetation composition and geomorphic setting directly mediate indirect relationships between landscape environmental processes and instream

  19. 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.

  20. Drought-induced legacy effects in wood growth across the Eastern and Midwestern U.S. are mediated by site climate, tree age, and drought sensitivity

    Science.gov (United States)

    Kannenberg, S.; Maxwell, J. T.; Pederson, N.; D'Orangeville, L.; Phillips, R.

    2017-12-01

    While it is widely known that drought reduces carbon (C) uptake in temperate forests, tree growth can also remain stagnant post-drought despite favorable climatic conditions. While such "legacy effects" are well established, the degree to which these effects depend on species identity or variability in site conditions is poorly quantified. We sought to uncover how site, species, climate, and tree age interact to affect the presence and magnitude of legacy effects in temperate trees following drought. To do this, we assembled dendrochronological records of 18 common species across 94 sites in Eastern and Midwestern U.S. forests and quantified drought-induced changes in wood growth in the year of the drought (hereafter "drought sensitivity") and the years after the drought (i.e., legacy effects). We predicted that species particularly prone to hydraulic damage (e.g., oaks) would have the least drought sensitivity yet experience larger legacy effects, and that this effect would be exacerbated at arid sites. Across all species and sites, wood growth was reduced by 14% in the year of the drought and by 7% post-drought. Surprisingly, legacy effects were smaller for oak species and larger across species known to be more drought sensitive (e.g. tulip poplar, maple, birch). As a result, we observed a positive relationship between a species' drought sensitivity and that species' legacy effect. These legacy effects were similar in size across a range of drought severities. Surprisingly, legacy effects were smaller in more arid sites - contrary to previous investigations in dryland ecosystems - perhaps indicating the role of adaptation in mediating a tree's recovery from drought. In addition, many species actually decreased the size of their legacy effects as they aged, despite no change in drought responses. Our results run contrary to our predictions, as species with the greatest drought sensitivity had the least ability to recover, and that younger mesic forests- not arid

  1. Effects of combustion and operating conditions on PCDD/PCDF emissions from power boilers burning salt-laden wood waste.

    Science.gov (United States)

    Leclerc, Denys; Duo, Wen Li; Vessey, Michelle

    2006-04-01

    This paper discusses the effects of combustion conditions on PCDD/PCDF emissions from pulp and paper power boilers burning salt-laden wood waste. We found no correlation between PCDD/PCDF emissions and carbon monoxide emissions. A good correlation was, however, observed between PCDD/PCDF emissions and the concentration of stack polynuclear aromatic hydrocarbons (PAHs) in the absence of TDF addition. Thus, poor combustion conditions responsible for the formation of products of incomplete combustion (PICs), such as PAHs and PCDD/PCDF precursors, increase PCDD/PCDF emissions. PAH concentrations increased with higher boiler load and/or low oxygen concentrations at the boiler exit, probably because of lower available residence times and insufficient excess air. Our findings are consistent with the current understanding that high ash carbon content generally favours heterogeneous reactions leading to either de novo synthesis of PCDD/PCDFs or their direct formation from precursors. We also found that, in grate-fired boilers, a linear increase in the grate/lower furnace temperature produces an exponential decrease in PCDD/PCDF emissions. Although the extent of this effect appears to be mill-specific, particularly at low temperatures, the results indicate that increasing the combustion temperature may decrease PCDD/PCDF emissions. It must be noted, however, that there are other variables, such as elevated ESP and stack temperatures, a high hog salt content, the presence of large amounts of PICs and a high Cl/S ratio, which contribute to higher PCDD/PCDFs emissions. Therefore, higher combustion temperatures, by themselves, will not necessarily result in low PCDD/PCDFs emissions.

  2. Effects of compost and phosphate on plant arsenic accumulation from soils near pressure-treated wood

    Energy Technology Data Exchange (ETDEWEB)

    Cao Xinde [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)]. E-mail: xcao@stevens.edu; Ma, Lena Q. [Soil and Water Science Department, University of Florida, Gainesville, FL (United States)

    2004-12-01

    Leaching of arsenic (As) from chromated copper arsenate (CCA)-treated wood may elevate soil arsenic levels. Thus, an environmental concern arises regarding accumulation of As in vegetables grown in these soils. In this study, a greenhouse experiment was conducted to evaluate As accumulation by vegetables from the soils adjacent to the CCA-treated utility poles and fences and examine the effects of soil amendments on plant As accumulation. Carrot (Daucus carota L.) and lettuce (Lactuca sativa L.) were grown for ten weeks in the soil with or without compost and phosphate amendments. As expected, elevated As concentrations were observed in the pole soil (43 mg kg{sup -1}) and in the fence soil (27 mg kg{sup -1}), resulting in enhanced As accumulation of 44 mg kg{sup -1} in carrot and 32 mg kg{sup -1} in lettuce. Addition of phosphate to soils increased As accumulation by 4.56-9.3 times for carrot and 2.45-10.1 for lettuce due to increased soil water-soluble As via replacement of arsenate by phosphate in soil. However, biosolid compost application significantly reduced plant As uptake by 79-86%, relative to the untreated soils. This suppression is possibly because of As adsorbed by biosolid organic mater, which reduced As phytoavailability. Fractionation analysis showed that biosolid decreased As in soil water-soluble, exchangeable, and carbonate fraction by 45%, whereas phosphate increased it up to 2.61 times, compared to the untreated soils. Our results indicate that growing vegetables in soils near CCA-treated wood may pose a risk of As exposure for humans. Compost amendment can reduce such a risk by reducing As accumulation by vegetables and can be an important strategy for remediating CCA-contaminated soils. Caution should be taken for phosphate application since it enhances As accumulation. - Capsule: Compost amendment can reduce As exposure risk for humans by reducing As accumulation by vegetables and can be an important strategy for remediating CCA

  3. Factors influencing laser cutting of wood

    Energy Technology Data Exchange (ETDEWEB)

    Barnekov, V. G.; McMillin, C. W.; Huber, H. A.

    1986-07-01

    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 work piece. Effects of beam power, mode, polarization, and stability are discussed as are aspects of optics, location of focal point, feed speed, gas-jet assist system and work piece thickness, density, and moisture content. (author)

  4. 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.

  5. COLOR STABILITY FOR WOOD PRODUCTS DURING USE: EFFECTS OF INORGANIC NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    Vincent Blanchard

    2011-04-01

    Full Text Available Despite significant progress having been achieved in recent years to improve wood’s durability, additional developments are still necessary to increase its color stability. ZnO and CeO2 nanoparticles were compared to UV absorbers (Tinuvin 477 DW, 292 and 5151 commonly used to stabilize the wood products color. Nanoparticles, with concentrations in the range 1 to 2 wt%, and UV absorbers, using concentrations advised by the manufacturer, were dispersed in a waterborne UV curable polyurethane/polyacrylate resin. Dispersions were carried out with a high speed mixer at 2,500 RPM with micro glass beads or not, depending on the form of the nanoparticles. Nanocomposite coatings were aged with a weather-o-meter (CI 3000+ - Atlas according ASTM G155. Color variations were measured with a colorimeter (BYK Gardner – Color Guide 45/0 working with the CIE L*a*b* system. The aim of the present study was to assess the effects of inorganic UV absorbers on the stabilization of color under indoor conditions. Results showed that nanoparticles (ZnO, CeO2 absorbed UV light frequencies in a manner similar to common organic molecules. Their efficiency was better at medium durations of light exposure, for which they could achieve the action of organic absorbers. Finally, the simultaneous use of both absorbers seems to create a protective synergy when degradation is due to UV energy alone.

  6. Effect of combustion condition on cytotoxic and inflammatory activity of residential wood combustion particles

    Science.gov (United States)

    Jalava, Pasi I.; Salonen, Raimo O.; Nuutinen, Kati; Pennanen, Arto S.; Happo, Mikko S.; Tissari, Jarkko; Frey, Anna; Hillamo, Risto; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2010-05-01

    Residential heating is an important local source of fine particles and may cause significant exposure and health effects in populations. We investigated the cytotoxic and inflammatory activity of particulate emissions from normal (NC) and smouldering (SC) combustion in one masonry heater. The PM 1-0.2 and PM 0.2 samples were collected from the dilution tunnel with a high-volume cascade impactor (HVCI). Mouse RAW 264.7 macrophages were exposed to the PM-samples for 24 h. Inflammatory mediators, (IL-6, TNFα and MIP-2), and cytotoxicity (MTT-test), were measured. Furthermore, apoptosis and cell cycle of macrophages were analyzed. The HVCI particulate samples were characterized for ions, elements and PAH compounds. Assays of elemental and organic carbon were conducted from parallel low volume samples. All the samples displayed mostly dose-dependent inflammatory and cytotoxic activity. SC samples were more potent than NC samples at inducing cytotoxicity and MIP-2 production, while the order of potency was reversed in TNFα production. SC-PM 1-0.2 sample was a significantly more potent inducer of apoptosis than the respective NC sample. After adjustment for the relative toxicity with emission factor (mg MJ -1), the SC-PM emissions had clearly higher inflammatory and cytotoxic potential than the NC-PM emissions. Thus, operational practice in batch burning of wood and the resultant combustion condition clearly affect the toxic potential of particulate emissions.

  7. Effect of Drying Method on the Permeability Coefficient of Oak Wood (Quercus infactoria

    Directory of Open Access Journals (Sweden)

    Shuboo Salehpour

    2014-05-01

    Full Text Available In this study, the effect of drying method on the permeability coefficient of the oak wood (Quercus infectoria Oliv was studied. Freshly-cut logs of oak were prepared from Oureman, the east area of Kourdistan in Iran. Then, boards with nominal thickness of 6 cm were cut. The boards were dried using two methods. In the first method, the boards were air dried to the moisture content close to FSP for 45 days and then they were kiln dried using T5-D1 schedule. In the second method, the boards were dried from green condition to the final moisture content of 10% using T5-D1 schedule. Then, the permeability coefficient in the transverse and longitudinal directions in both heartwood and sapwood regions was measured, separately. Results showed that the permeability of oak boards dried by kiln drying method both in the transverse and longitudinal directions and also in the heartwood and sapwood regions was greater than that of those dried by the combined method (air drying + kiln drying.

  8. Effects of impregnation of Eucalyptus grandis wood with fire-retardant salt on the production and quality of its charcoal; Efeito da impregnacao da madeira de Eucalyptus grandis com sais ignifugos na producao e na qualidade do carvao

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Marcia Macedo Ladeira; Vital, Benedito Rocha; Gomide, Jose Livio; Della Lucia, Ricardo Marius; Leite, Helio Garcia [Vicosa Univ., MG (Brazil). Dept. de Engenharia Florestal

    1998-12-31

    The present work was carried out to investigate the effects of impregnating Eucalyptus grandis wood fire retardant salts on the production and quality of its charcoal. The wood used came from a commercial stand of 72-month old Eucalyptus grandis planted at an initial 3.0 x 2.0 m spacing, established in Vicosa, Minas Gerais, Brazil. This wood was transformed in chips, treated with some fire-retardant salts and carbonized. results were evaluated through multivariate analysis. The difference among the 34 treatments, evaluated on the wood characteristics, based on group analysis, and using the distance D{sup 2} of Mahalanobis and the Tocher method, showed distinct group and subgroup formations. Based on technological data, treatment with ammonium sulphate at 15% concentration was classified as being the most promising one. The use of canonic variables analysis showed that the treatment with ammonium sulphate at a concentration of 5% was the best, and was given preference because of its lower sulphur content. (author) 12 refs., 1 fig., 7 tabs.

  9. Leachates from wood ash - effects of storage on soil; Lakvatten fraan skogsbraensleaska - markpaaverkan av lagring

    Energy Technology Data Exchange (ETDEWEB)

    Valeur, Inger; Thelin, Gunnar (EkoBalans FenixAB, Lund (Sweden))

    2012-02-15

    In this study we monitored leachate from wood ash stored in a pile in an outdoor environment during six months. Our aim was to contribute with knowledge about leaching behavior and risks connected to storages of wood ash, and more generally leaching from piles affected by various weather conditions. Impacts on soil from storage of wood ash was also included in the study as well as different transport scenarios for recycling wood ash to the forest. Bioenergy output from Swedish forests has more than doubled the last 10 years and as nutrient rich parts as needles and branches (grot) is also taken out, the nutrient export from the forest site has increased by a factor of three to five. To counteract depletion of nutrients in forest soils, wood ash is returned to the forest. Apart from nitrogen, wood ash contains all the nutrients and trace elements that were in the wood before combustion. The wood ash must be hardened before spreading to make it less reactive. The ash self hardens when stored in an outdoor environment for 3 to 6 months and according to the waste act this should be done on a paved area. However, wood ash which is meant to be recycled to the forest has naturally very low amounts of polluting elements and shall also fulfill limit values, set up by the Swedish Forest Agency. As it is so that the storage is during a limited period of time and the ash shall be transported, not only to one place but too several smaller areas, this has given rise to the thought of storing the ash closer to the spreading area. However, the ash would then probably be stored in a non paved area, as the number of paved areas in forests is scarce. If storage close to the spreading area could be done, the distance for transports connected to recycling the ash would presumably be decrease by a factor of two or three. To get permission to store ash on a non paved area, there must be enough data available which can ensure that there are no environmental risks associated to the storage

  10. In a world of big data, small effects can still matter: a reply to Boyce, Daly, Hounkpatin, and Wood (2017)

    OpenAIRE

    Matz, SC; Gladstone, JJ; Stillwell, David John

    2017-01-01

    We make three points in response to Boyce, Daly, Hounkpatin, and Wood (2017). First, we clarify a misunderstanding of the goal of our analyses, which was to investigate the links between life satisfaction and spending patterns, rather than spending volume. Second, we report a simulation study we ran to demonstrate that our results were not driven by the proposed statistical artifact. Finally, we discuss the broader issue of why, in a world of big data, small but reliable effect sizes can be v...

  11. Effect of wood type and thickness on acetification kinetics in traditional vinegar production

    Directory of Open Access Journals (Sweden)

    Maria-Jesús Torija

    2009-04-01

    Full Text Available Maria-Jesús Torija1, Estibaliz Mateo1, Carlos-Alfredo Vegas1, Carla Jara1, Angel González1, Montse Poblet1, Cristina Reguant1, Jóse-Manuel Guillamon2, Albert Mas11Biotecnología enológica. Departament de Bioquímica i Biotecnologia, Facultat d’enologia, Universitat Rovira i Virgili, Tarragona, Spain; 2Departamento de Biotecnología de los Alimentos, Instituto de Agroquímica y Tecnología de Alimentos (CSIC, Burjassot, València, SpainAbstract: Traditional vinegar production is a lengthy process which implies high operational risks and jeopardizes the organoleptic characteristics of the final product. In an effort to solve these problems without changing the traditional model, we modified the wood type and thickness of vinegar barrels. We acetified in triplicate in barrels made of acacia, cherry, chestnut, and oak and in three wood thicknesses (15, 20, and 25 mm in two different vinegar plants. The operating volume was set at 60 L. Reducing wood thickness improved neither maximum acetification velocity or the total length of the process, and in some cases even worsened them. The process took longer in oak barrels than in other types of wood barrel in one of the vinegar plants. Therefore, the choice of wood is a parameter to be considered in the wine vinegar production. Keywords: acacia, cherry, chestnut, oak, acetic acid bacteria

  12. European wood-fuel trade

    International Nuclear Information System (INIS)

    Hillring, B.; Vinterbaeck, J.

    2001-01-01

    This paper discusses research carried out during the l990s on European wood fuel trade at the Department of Forest Management and Products, SLU, in Sweden. Utilisation of wood-fuels and other biofuels increased very rapidly in some regions during that period. Biofuels are replacing fossil fuels which is an effective way to reduce the future influence of green house gases on the climate. The results indicate a rapid increase in wood-fuel trade in Europe from low levels and with a limited number of countries involved. The chief products traded are wood pellets, wood chips and recycled wood. The main trading countries are, for export, Germany and the Baltic states and, for import, Sweden, Denmark and to some extent the Netherlands. In the future, the increased use of biofuel in European countries is expected to intensify activity in this trade. (orig.)

  13. Effects of wood chip ash fertilization on soil chemistry in a Norway spruce plantation on a nutrient-poor soil

    DEFF Research Database (Denmark)

    Ingerslev, Morten; Hansen, Mette; Pedersen, Lars Bo

    2014-01-01

    of wood chip ash application on soil chemistry in a 44-year-old Norway spruce (Picea abies) plantation on a nutrient-poor soil in Denmark and to investigate the effect of applying different ash types and doses. Soil samples were collected and analyzed 2.5years (3 growing seasons) after ash application....... This study shows that, regardless of ash formulation, preparation or dose, application of wood ash to forest soil has a liming effect in the O-horizon manifested as an increase in CECe, BS and pH. This effect was not seen in the mineral soil within the time frame of this study. At the same time, an increase...... in Cd was found in the O-horizon, corresponding to the amount added in the ashes. Generally, no other increase in soil contents of the heavy metals was seen. Hardening of the wood ash did not decrease the chemical impact on the soil chemistry as compared to non-treated ash whereas an increase in ash...

  14. Effects of Large Wood on River-Floodplain Connectivity in a Headwater Appalachian Stream

    Science.gov (United States)

    Keys, T.; Govenor, H.; Jones, C. N.; Hession, W. C.; Scott, D.; Hester, E. T.

    2017-12-01

    Large wood (LW) plays an important, yet often undervalued role in stream ecosystems. Traditionally, LW has been removed from streams for aesthetic, navigational, and flood mitigation purposes. However, extensive research over the last three decades has directly linked LW to critical ecosystem functions including habitat provisioning, stream geomorphic stability, and water quality improvements; and as such, LW has increasingly been implemented in stream restoration activities. One of the proposed benefits to this restoration approach is that LW increases river-floodplain connectivity, potentially decreasing downstream flood peaks and improving water quality. Here, we conducted two experiential floods (i.e., one with and one without LW) in a headwater, agricultural stream to explore the effect of LW on river-floodplain connectivity and resulting hydrodynamic processes. During each flood, we released an equal amount of water to the stream channel, measured stream discharge at upstream and downstream boundaries, and measured inundation depth at multiple locations across the floodplain. We then utilized a 2-dimensional hydrodynamic model (HEC-RAS) to simulate floodplain hydrodynamics. We first calibrated the model using observations from the two experimental floods. Then, we utilized the calibrated model to evaluate differing LW placement strategies and effects under various flow conditions. Results show that the addition of LW to the channel decreased channel velocity and increased inundation extent, inundation depth, and floodplain velocity. Differential placement of LW along the stream impacted the levels of floodplain discharge, primarily due to the geomorphic characteristics of the stream. Finally, we examined the effects of LW on floodplain hydrodynamics across a synthetic flow record, and found that the magnitude of river-floodplain connectivity decreased as recurrence interval increased, with limited impacts on storm events with a recurrence interval of 25 years

  15. Effects of post-fire wood management strategies on vegetation recovery and land surface temperature (LST) estimated from Landsat images

    Science.gov (United States)

    Vlassova, Lidia; Pérez-Cabello, Fernando

    2016-02-01

    The study contributes remote sensing data to the discussion about effects of post-fire wood management strategies on forest regeneration. Land surface temperature (LST) and Normalized Differenced Vegetation Index (NDVI), estimated from Landsat-8 images are used as indicators of Pinus halepensis ecosystem recovery after 2008 fire in areas of three post-fire treatments: (1) salvage logging with wood extraction from the site on skidders in suspended position (SL); (2) snag shredding in situ leaving wood debris in place (SS) performed two years after the event; and (3) non-intervention control areas (CL) where all snags were left standing. Six years after the fire NDVI values ∼0.5 estimated from satellite images and field radiometry indicate considerable vegetation recovery due to efficient regeneration traits developed by the dominant plant species. However, two years after management activities in part of the burnt area, the effect of SL and SS on ecosystem recovery is observed in terms of both LST and NDVI. Statistically significant differences are detected between the intervened areas (SL and SS) and control areas of non-intervention (CL); no difference is registered between zones of different intervention types (SL and SS). CL areas are on average 1 °C cooler and 10% greener than those corresponding to either SL or SS, because of the beneficial effects of burnt wood residuals, which favor forest recovery through (i) enhanced nutrient cycling in soils, (ii) avoidance of soil surface disturbance and mechanical damage of seedlings typical to the managed areas, and (iii) ameliorated microclimate. The results of the study show that in fire-resilient ecosystems, such as P. halepensis forests, NDVI is higher and LST is lower in areas with no management intervention, being an indication of more favorable conditions for vegetation regeneration.

  16. 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)

  17. THE EFFECT OF GRAIN ANGLE AND SPECIES ON THERMAL CONDUCTIVITY OF SOME SELECTED WOOD SPECIES

    Directory of Open Access Journals (Sweden)

    Rasit Esen

    2011-06-01

    Full Text Available In this study the thermal conductivity of different wood materials was determined. For this purpose, Scots pine (Pinus sylvestris L., Uludag fir (Abies Bornmülleriana Matff, Oriental beech (Fagus orientalis L, Oak (Quercus robur L., and Chestnut of Anatolia (Castanea sativa Mill. woods were used. In the test, the thermal conductivity of the woods was measured according to procedure of ASTM C 1113-99 standards. The lowest thermal conductivity was obtained in the perpendicular direction of Scots pine samples as 0.156 Kcal/mh°C. The highest thermal conductivity was obtained from perpendicular direction of samples in Oriental beech as 0.331 Kcal/mh°C.

  18. A benthic survey of Aliwal Shoal and assessment of the effects of a wood pulp effluent on the reef

    International Nuclear Information System (INIS)

    Schleyer, Michael H. . E-mail schleyer@ori.org.za; Heikoop, Jeffrey M.; Risk, Michael J.

    2006-01-01

    Aliwal Shoal lies south of Durban in South Africa and has been the subject of recent bathymetric, seafloor and benthic surveys. ANOVA of the biological data revealed that the biota were uniformly distributed on the reef with the exception of encrusting sponges and algae on rock. The variations in distribution of these biota were significant and, in the case of the encrusting sponges, appeared to be related to the discharge of a wood pulp effluent. Further evidence of this was suggested by stable isotope analyses of representative organisms. The encrusting sponges were recommended as good candidates for further monitoring of the effects of the wood pulp effluent on Aliwal Shoal as the effluent pipeline has been extended

  19. The effect of wood ash fertilization on soil respiration and tree stand growth in boreal peatland forests

    Science.gov (United States)

    Liimatainen, Maarit; Maljanen, Marja; Hytönen, Jyrki

    2017-04-01

    Out of Finland's original 10 million hectares of peatlands over half has been drained for forestry. Natural peatlands act as a sink for carbon but when peatland is drained, increased oxygen concentration in the peat accelerates the aerobic decomposition of the old organic matter of the peat leading to carbon dioxide (CO2) emissions to atmosphere. Increasing use of bioenergy increases also the amount of ash produced as a byproduct in power plants. Wood ash contains all essential nutrients for trees to grow except nitrogen. Therefore, wood ash is ideal fertilizer for nitrogen rich peatland forests where lack of phosphorus or potassium may restrict tree growth. At the moment, wood ash is the only available PK-fertilizer for peatland forests in Finland and areas of peatland forests fertilized with ash are increasing annually. The effects of wood ash on vegetation, soil properties and tree growth are rather well known although most of the studies have been made using fine ash whereas nowadays mostly stabilized ash (e.g. granulated) is used. Transporting and spreading of stabilized ash is easier than that of dusty fine ash. Also, slower leaching rate of nutrients is environmentally beneficial and prolongs the fertilizer effect. The knowledge on the impact of granulated wood ash on greenhouse gas emissions is still very limited. The aim of this study was to examine the effects of granulated wood ash on CO2 emissions from peat and tree stand growth. Field measurements were done in two boreal peatland forests in 2011 and 2012. One of the sites is more nutrient rich with soil carbon to nitrogen ratio (C/N) of 18 whereas the other site is nutrient poor with C/N ratio of 82. Both sites were fertilized with granulated wood ash in 2003 (5000 kg ha-1). The effect of fertilization was followed with tree stand measurements conducted 0, 5 and 10 years after the fertilization. The CO2 emissions of the decomposing peat (heterotrophic respiration) were measured from study plots where

  20. Final Report: Development of Renewable Microbial Polyesters for Cost Effective and Energy- Efficient Wood-Plastic Composites

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, David N.; Emerick, Robert W.; England, Alfred B.; Flanders, James P.; Loge, Frank J.; Wiedeman, Katherine A.; Wolcott, Michael P.

    2010-03-31

    In this project, we proposed to produce wood fiber reinforced thermoplastic composites (WFRTCs) using microbial thermoplastic polyesters in place of petroleum-derived plastic. WFRTCs are a rapidly growing product area, averaging a 38% growth rate since 1997. Their production is dependent on substantial quantities of petroleum based thermoplastics, increasing their overall energy costs by over 230% when compared to traditional Engineered Wood Products (EWP). Utilizing bio-based thermoplastics for these materials can reduce our dependence on foreign petroleum. We have demonstrated that biopolymers (polyhydroxyalkanoates, PHA) can be successfully produced from wood pulping waste streams and that viable wood fiber reinforced thermoplastic composite products can be produced from these materials. The results show that microbial polyester (PHB in this study) can be extruded together with wastewater-derived cell mass and wood flour into deck products having performance properties comparable to existing commercial HDPE/WF composite products. This study has thus proven the underlying concept that the microbial polyesters produced from waste effluents can be used to make cost-effective and energy-efficient wood-plastic composites. The cost of purified microbial polyesters is about 5-20 times that of HDPE depending on the cost of crude oil, due to high purification (40%), carbon substrate (40%) and sterilized fermentation (20%) costs for the PHB. Hence, the ability to produce competitive and functional composites with unpurified PHA-biomass mixtures from waste carbon sources in unsterile systems—without cell debris removal—is a significant step forward in producing competitive value-added structural composites from forest products residuals using a biorefinery approach. As demonstrated in the energy and waste analysis for the project, significant energy savings and waste reductions can also be realized using this approach. We recommend that the next step for development of

  1. A revised multi-Fickian moisture transport model to describe non-Fickian effects in wood

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Damkilde, Lars; Svensson, Staffan

    2007-01-01

    This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multi-phase model. This type of model describes the complex moisture transport system in wood, which consists of separate water vapor and bound-water diffusion interacting through sorption...... sorption allow a simplification of the system to be modeled by a single Fickian diffusion equation. To determine the response of the system, the sorption rate model is essential. Here the function modeling the moisture-dependent adsorption rate is investigated based on existing experiments on thin wood...

  2. 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.

  3. 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)

  4. 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)

  5. [Suppressive Effects of Extract of Cedar Wood on Heat-induced Expression of Cellular Heat Shock Protein].

    Science.gov (United States)

    Miyakoshi, Junji; Matsubara, Eri; Narita, Eijiro; Koyama, Shin; Shimizu, Yoko; Kawai, Shuichi

    2018-01-01

     In recent years, highly antimicrobial properties of cedar heartwood essential oil against the wood-rotting fungi and pathogenic fungi have been reported in several papers. Antimicrobial properties against oral bacteria by hinokitiol contained in Thujopsis have been also extensively studied. The relation of naturally derived components and human immune system has been studied in some previous papers. In the present study, we focused on Japanese cedar, which has the widest artificial afforestation site in the country among various tree species. Extract oil was obtained from mixture of sapwood and heartwood of about 40-year cedar grown in Oguni, Kumamoto, Japan. We examined the influence of extract components from Japanese cedar woods on the expression of heat shock protein 70 (Hsp70) during heating, and on the micronucleus formation induced by the treatment of bleomycin as a DNA damaging agent. Cell lines used in this study were human fetal glial cells (SVGp12) and human glioma cells (MO54). Remarkable suppression of the Hsp70 expression induced by heating at 43°C was detected by the treatment of cedar extract in both SVGp12 and MO54 cells. We also found that cedar extract had an inhibitory tendency to reduce the micronucleus formation induced by bleomycin. From these results, the extract components from Japanese cedar woods would have an inhibitory effect of the stress response as a suppression of the heat-induced Hsp70 expression, and might have a reductive effect on carcinogenicity.

  6. Understanding Digital Learning and Its Variable Effects

    Science.gov (United States)

    Means, B.

    2016-12-01

    An increasing proportion of undergraduate courses use an online or blended learning format. This trend signals major changes in the kind of instruction students receive in their STEM courses, yet evidence about the effectiveness of these new approaches is sparse. Existing syntheses and meta-analyses summarize outcomes from experimental or quasi-experimental studies of online and blended courses and document how few studies incorporate proper controls for differences in student characteristics, instructor behaviors, and other course conditions. The evidence that is available suggests that on average blended courses are equal to or better than traditional face-to-face courses and that online courses are equivalent in terms of learning outcomes. But these averages conceal a tremendous underlying variability. Results vary markedly from course to course, even when the same technology is used in both. Some research suggests that online instruction puts lower-achieving students at a disadvantage. It is clear that introducing digital learning per se is no guarantee that student engagement and learning will be enhanced. Getting more consistently positive impacts out of learning technologies is going to require systematic characterization of the features of learning technologies and associated instructional practices as well as attention to context and student characteristics. This presentation will present a framework for characterizing essential features of digital learning resources, implementation practices, and conditions. It will also summarize the research evidence with respect to the learning impacts of specific technology features including spaced practice, immediate feedback, mastery learning based pacing, visualizations and simulations, gaming features, prompts for explanations and reflection, and tools for online collaboration.

  7. 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...

  8. Does reintroducing large wood influence the hydraulic landscape of a lowland river system?

    Science.gov (United States)

    Matheson, Adrian; Thoms, Martin; Reid, Michael

    2017-09-01

    Our understanding of the effectiveness of reintroduced large wood for restoration is largely based on studies from high energy river systems. By contrast, few studies of the effectiveness of reintroducing large wood have been undertaken on large, low energy, lowland river systems: river systems where large wood is a significant physical feature on the in-channel environment. This study investigated the effect of reintroduced large wood on the hydraulic landscape of the Barwon-Darling River, Australia, at low flows. To achieve this, the study compared three hydraulic landscapes of replicated reference (naturally wooded), control (unwooded,) and managed (wood reintroduced) treatments on three low flow periods. These time periods were prior to the reintroduction of large wood to managed reaches; several months after the reintroduction of large wood into the managed reaches; and then more than four years after wood reintroduction following several large flood events. Hydraulic landscapes of reaches were characterised using a range of spatial measures calculated from velocity measurements taken with a boat-mounted Acoustic Doppler Profiler. We hypothesised that reintroduced large wood would increase the diversity of the hydraulic landscape at low flows and that managed reaches would be more similar to the reference reaches. Our results suggest that the reintroduction of large wood did not significantly change the character of the hydraulic landscape at the reach scale after several months (p = 0.16) or several years (p = 0.29). Overall, the character of the hydraulic landscape in the managed reaches was more similar to the hydraulic landscape of the control reaches than the hydraulic landscape of the reference reaches, at low flows. Some variability in the hydraulic landscapes was detected over time, and this may reflect reworking of riverbed sediments and sensitivity to variation in discharge. The lack of a response in the low flow hydraulic landscape to the

  9. Drying of firewood - the effect of harvesting time, tree species and shelter of stacked wood

    International Nuclear Information System (INIS)

    Nord-Larsen, Thomas; Bergstedt, Andreas; Farver, Ole; Heding, Niels

    2011-01-01

    Firewood represents a renewable source of energy and is the main source of energy for about half the World's population. When burning firewood in domestic stoves, combustion and thus energy efficiency is dependent on the moisture content of the wood. In Denmark, it is generally recommended that moisture content should be no more than 180 g kg -1 total weight. This study aims to assess the effect of species, harvesting time and shelter on the drying of stacked firewood. After felling, the moisture content declined to a relative stable level for all species. The rate of drying depended on the felling time, tree species, and the presence of shelter. The lower asymptotic moisture content depended mainly on the presence of shelter and averaged 188 g kg -1 total weight for frames left in the open and 154 g kg -1 total weight for frames covered by a shelter. It is concluded that Norway spruce felled during the early summer may obtain an acceptable moisture content at the onset of the heating season. Deciduous trees should be felled during the winter or early spring and stored under shelter to be suitable for burning before the heating season. Shelter was found to be of great importance to maintain an acceptable moisture content of firewood in storage during winter. -- Highlights: → Firewood is the main source of energy for about half the World's population. → The moisture content of firewood should be no more than 18% of total weight. → Drying rate depended on the felling time, tree species, and the presence of shelter. → Lower asymptotic moisture content depended mainly on the presence of a shelter. → Sheltered storage is very important to maintain an acceptable moisture content of the firewood.

  10. EFFECT OF EXTRACTIVES AND CARBONIZATION TEMPERATURE ON ENERGY CHARACTERISTICS OF WOOD WASTE IN AMAZON RAINFOREST

    Directory of Open Access Journals (Sweden)

    Jordão Cabral Moulin

    2017-06-01

    Full Text Available The objective of this study was to evaluate the effect of extractives soluble in hot water, besides final carbonization temperatures, on the gravimetric yield and properties of charcoal for waste of three native forest species from the Amazon region. Waste cuttings of Ipé, Grapia and Maçaranduba species, from the machine processing for joinery of a company in the State of Pará, were used. Carbonization was carried out in an adapted electric furnace with a heating rate of 1.67°C min-1 and final temperatures of 500, 600 and 700°C. The waste was carbonized fresh after extraction in hot water to remove extractives. Gravimetric yields were analyzed, as well as chemical features and high heating value. In the evaluation of the experiment, arranged in a factorial scheme with three factors (species x temperature x material with and without extraction, and Principal Component Analysis used too. The presence of extractives (soluble in hot water from wood waste had little influence on the gravimetric yield and immediate chemical composition of charcoal; however, it showed a greater high heating value and lower contents of hydrogen and nitrogen. The increase in the final carbonization temperature reduced the gravimetric yield in charcoal, the content of volatile materials and hydrogen, with a higher content of fixed carbon, carbon and high heating value. The treatments with the best energy characteristics were obtained from Ipé and Maçaranduba charcoals with extractives produced at 600°C, in addition to Ipê and Maçaranduba charcoals with and without extractives obtained at 700°C.

  11. Effect of coating systems on the vaporization of pentachlorophenol from treated wood

    Science.gov (United States)

    L. L. Ingram; G. D. McGinnis; P. M. Pope; W. C. Feist

    1983-01-01

    Specimens of southern pine treated with pentachlorophenol (penta) in mineral spirits (dip treatment), penta in P9 type A oil and penta in methylene chloride (pressure treatments) were used to evaluate the efficacy of different types of coatings in suppressing the vaporization of penta from treated wood. The clear film-forming coatings, such as polyurethane and alkyds,...

  12. Effects of large herbivores on wood pasture dynamics in a European wetland system

    NARCIS (Netherlands)

    Cornelissen, P.; Bokdam, J.; Sykora, K.V.; Berendse, F.

    2014-01-01

    Whether self-regulating large herbivores play a key role in the development of wood-pasture landscapes remains a crucial unanswered question for both ecological theory and nature conservation. We describe and analyse how a ‘partly self-regulating’ population of cattle, horses and red deer affected

  13. Effects of experimental stem burial on radial growth and wood anatomy of pedunculate oak

    NARCIS (Netherlands)

    Copini, P.; Decuyper, M.; Sass-Klaassen, U.G.W.; Gärtner, H.; Mohren, G.M.J.; Ouden, den J.

    2015-01-01

    In dendrogeomorphology, abrupt changes in wood anatomy are frequently used to date the exact year of burial and exposure events. However, few studies have addressed the precision and underlying mechanisms of these changes. In a field experiment, performed in a drift-sand area in the Netherlands, we

  14. Effects of air pollution on morphological and anatomical characteristics of Pinus Eldarica Wood

    Science.gov (United States)

    Vahidreza Safdari; Moinuddin Ahmed; Margaret S. Devall; Vilma Bayramzadeh

    2012-01-01

    Air pollution, including automobile exhaust pollution, can affect anatomical and morphological characteristics of wood. In order to evaluate this subject, the Pinus eldarica trees of Chitgar Park in Tehran, which extends from a crowded highway in the south (polluted site) to the semi polluted midsection and to Alborz Mountain in the north (unpolluted...

  15. Effects of acidity on primary productivity in lakes: phytoplankton. [Lakes Panther, Sagamore, and Woods

    Energy Technology Data Exchange (ETDEWEB)

    Hendrey, G R

    1979-01-01

    Relationships between phytoplankton communities and lake acidity are being studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Numbers of phytoplankton species observed as of July 31, 1979 are Woods 27, Sagamore 38, and Panther 64, conforming to other observations that species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity found in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly instead of occuring very close to ice-out. Contributions of netplankton (net > 48 ..mu..m), nannoplankton (48 > nanno > 20 ..mu..m) and ultraplankton (20 > ultra >0.45 ..mu..m) to productivity per m/sup -2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification leading to decreased availability of phosphorus). The amount of /sup 14/C-labelled dissolved photosynthate (/sup 14/C-DOM), as a percent of total productivity, is ordered Woods > Sagamore > Panther. This is consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. (ERB)

  16. 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...

  17. Effect of Decay on Ultrasonic Velocity and Attenuation Measurements in Wood

    Science.gov (United States)

    Megan McGovern; Adam Senalik; George Chen; Frank C. Beall; Henrique Reis

    2013-01-01

    The percentage mass loss of loblolly pine (pinus taeda) wood cube specimens exposed to Gloeophyllum fungus (Gloeophyllum trabeum) for increasing periods of time ranging from 1 to 12 weeks was recorded after being subjected to controlled decay following ASTM International standard ASTM D 1423-99. The specimens’ corresponding volume...

  18. Effect of temperature during wood torrefaction on the formation of lignin liquid intermediates

    Science.gov (United States)

    Manuel Raul Pelaez-Samaniego; Vikram Yadama; Manuel Garcia-Perez; Eini Lowell; Armando G. McDonald

    2014-01-01

    Torrefaction enhances physical properties of lignocellulosic biomass and improves its grindability. Energy densification, via fuel pellets production, is one of the most promising uses of torrefaction. Lignin contributes to self-bonding of wood particles during pelletization. In biomass thermal pretreatment, part oflignin (in the form of lignin liquid intermediates –...

  19. 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 ...

  20. Effect of fiberglass reinforcement on the behavior of bolted wood connections

    Science.gov (United States)

    Lawrence A. Soltis; Robert J. Ross; Daniel E. Windorski

    1997-01-01

    Bolted connections often fail by a shear plug or by splitting beneath the bolt caused by tension perpendicular-to-grain stress as the bolt wedges its way through the wood. Preventing this type of failure enhances both the capacity and reliability of bolted connections. This research investigated the use of fiberglass reinforcement to enhance the load-carrying capacity...

  1. The effect of planting density on the wood quality of South African ...

    African Journals Online (AJOL)

    This paper presents the results of a wood property and sawn board quality study performed on disc samples and sawlogs taken from a 23-year-old Eucalyptus grandis Nelder 1a spacing trial at J.D.M. Keet plantation near Tzaneen. Ten trees from each of four markedly different planting densities were chosen to provide ...

  2. Copper naphthenate: an update and status report on an effective wood pole and crossarm preservative for Canada

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, M.

    2002-07-01

    The purpose of this PowerPoint presentation was three-fold: (1) tp provide information on copper naphthenate and treated wood, (2) to demonstrate that copper naphthenate is an excellent choice for wood poles, and (3) to provide an evaluation of copper naphthenate-treated poles in service. The author proceeded by describing the nature of naphthenic acid and copper naphthenate. Only those petroleum-based alicyclic carboxylic acids with acid numbers between 180-250 milligram KOH/gram. The author specified that two samples produced in Europe and Australia contain either naphthenic acid blends or 100 per cent synthetic acids, which could result in reduced preservatives performance. As for copper naphthenate, it is produced by the reaction of naphthenic acid and copper compounds. A drawing of the molecule was displayed. The toxicity for humans is low, minimal to avian, and moderate to high aquatic toxicity. Discovered in the late 1800s, copper naphthenate is used for pressure and non-pressure treatment, and the anticipated annual growth rate is 5 per cent. The regulatory status of copper naphthenate was described in both the United States and Canada. Results from field skate decay measurements were presented. The author concluded by stating that copper naphthenate is an excellent choice, recognized for its performance and efficacy. It is considered as an Environmental Protection Agency (EPA) unrestricted use pesticide, imposes minimal regulatory requirements on treaters and users, and there are no federal disposal restrictions. Copper naphthenate is a safe and effective wood preservative. refs., figs.

  3. 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.

  4. Public opinion and wood energy

    Science.gov (United States)

    Sarah Hitchner; John Schelhas; Teppo Hujala; J. Peter Brosius

    2014-01-01

    As wood-based bioenergy continues to develop around the world, it will utilize forestlands in new ways and will have different effects on a number of stakeholders, including forest landowners, local communities, extant industries, policymakers, investors, and others. As more stakeholders become involved in the wood energy web, and as the general public becomes more...

  5. Adaptability to climate change in forestry species: drought effects on growth and wood anatomy of ponderosa pines growing at different competition levels

    OpenAIRE

    Fernández, M.E.; Gyenge, J.E.; de Urquiza, M.M.; Varela, S.

    2012-01-01

    More stressful conditions are expected due to climatic change in several regions, including Patagonia, South-America. In this region, there are no studies about the impact of severe drought events on growth and wood characteristics of the most planted forestry species, Pinus ponderosa (Doug. ex-Laws). The objective of this study was to quantify the effect of a severe drought event on annual stem growth and functional wood anatomy of pines growing at different plantation densities aiming to un...

  6. Photodegradation of wood and depth profile analysis

    International Nuclear Information System (INIS)

    Kataoka, Y.

    2008-01-01

    Photochemical degradation is a key process of the weathering that occurs when wood is exposed outdoors. It is also a major cause of the discoloration of wood in indoor applications. The effects of sunlight on the chemical composition of wood are superficial in nature, but estimates of the depth at which photodegradation occurs in wood vary greatly from 80 microm to as much as 2540 mic rom. Better understanding of the photodegradation of wood through depth profile analysis is desirable because it would allow the development of more effective photo-protective treatments that target the surface layers of wood most susceptible to photodegradation. This paper briefly describes fundamental aspects of photodegradation of wood and reviews progress made in the field of depth profile study on the photodegradation of wood. (author)

  7. 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...

  8. An Effective Outpatient Appointment System for General Leonard Wood Army Community Hospital

    Science.gov (United States)

    1990-07-13

    collection, donated many hours. She asked patients about the appointment system and personally observed clinic personnel. Additionally, as a consumer ...appointment system which must satisfy both the demands 0of external ( patients ) and internal (physicians) customers . At the o0 C 0 same time, the...its health care environment. A variable that can effect patient flow is centralization or decentralization of the registration and appointment system

  9. Effects of variable transformations on errors in FORM results

    International Nuclear Information System (INIS)

    Qin Quan; Lin Daojin; Mei Gang; Chen Hao

    2006-01-01

    On the basis of studies on second partial derivatives of the variable transformation functions for nine different non-normal variables the paper comprehensively discusses the effects of the transformation on FORM results and shows that senses and values of the errors in FORM results depend on distributions of the basic variables, whether resistances or actions basic variables represent, and the design point locations in the standard normal space. The transformations of the exponential or Gamma resistance variables can generate +24% errors in the FORM failure probability, and the transformation of Frechet action variables could generate -31% errors

  10. 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.

  11. 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.

  12. 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.

  13. Enzymic hydrolysis of woods. IV. The effect of pretreatment with aqueous ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Ishihara, T; Ishihara, M

    1979-01-01

    In the hydrolysis of Betusa platyphylla, B. Maximowiczii, and Populus mazimowiczee with cellulase (I) at room temperature, treatment with 5% NH/sub 4/OH resulted in the formation of reducing sugars corresponding to aporoximately half of the amount of wood polysaccharides. The NH/sub 3/-treated B. platyphylla in the presence of I gave yeast in a yield of 40% of the sugar.

  14. Effects of wood anisotropy on Teredo naval is attack and its implications for in -situ preservation of archaeological wood in the marine environment

    DEFF Research Database (Denmark)

    Eriksen, Anne Marie; Lynnerup, Niels; Villa, Chiara

    2014-01-01

    the specific direction. The current results show that the attack is likely to follow the radial section of the wood fibres. These results have implications for archaeological interpretation and conservation. For example, the results show that ships built in a radial cut may require more protection than those......-sectional and if the resulting tunnels are oriented in a specific direction according to the tree fibres within the wood. Computed tomography (CT) scanning is a digital geometry process used to generate a three-dimensional image of the inside of an object such as a wooden block. Blocks of pine were cut with tangential, radial...... to the cross section, indicating a selective attack pattern. X-ray imaging shows a severe attack on all blocks, but the single tunnels can be difficult to follow on the image. CT-scanning images make it possible to isolate single tunnels and follow them throughout the block, making it possible to examine...

  15. Effects of heavy metal pollution on red wood ant (Formica s. str.) populations

    International Nuclear Information System (INIS)

    Eeva, T.; Sorvari, J.; Koivunen, V.

    2004-01-01

    We studied the species composition, mound population densities, relative abundance and colony sizes of red wood ants along a well known air pollution gradient of a copper smelter in Southwest Finland. The dominant species, Formica aquilonia, was further studied for heavy metal (Al, Cu, Cd, Ni, Zn, As, Pb, Hg) levels and morphological characters (body mass, head width, labial gland disease) of workers. We found five species belonging to Formica s. str., and two of them showed changes in their relative abundance, which could not be explained by natural habitat differences. Nest mound volumes were 34% smaller in the polluted area, suggesting that smaller colonies can be maintained there. The heavy metal levels in F. aquilonia workers were higher in the polluted area for all metals, except Hg. The largest relative differences between the study areas (polluted/unpolluted) were found for As (4.1), Ni (2.4), Cu (2.1) and Pb (1.8). Morphological characters of workers were not related to the heavy metal levels. Our data showed that red wood ants can tolerate relatively high amounts of heavy metals and maintain reproducing colonies even in a heavily polluted area, but on the basis of smaller colony sizes, pollution stress may also cause trade-offs in reproduction. - Capsule: Five species of red wood ants vary in their sensitivity to heavy metal pollution but all of them had smaller colonies in a polluted area

  16. Effect of Different Heat Treatment Temperatures on the Chemical Composition and Structure of Chinese Fir Wood

    Directory of Open Access Journals (Sweden)

    Shichao Cheng

    2016-03-01

    Full Text Available The properties of wood can be improved after heat-treatment. There have been many studies dealing with mechanical properties and chemical modifications of heat-treated wood. The purpose of this paper is to provide a new analysis method, to give better insights on the hemicelluloses, cellulose, and lignin contents of heat-treated wood by using Fourier transform infrared (FT-IR and two-dimensional infrared (2D-IR spectroscopies. The FT-IR spectra results showed progressive degradation in the carbonyl groups of the glucuronic acid units and degradation of the pyranose of hemicelluloses. These changes were measured as the percentage decrease of crystalline cellulose and the loss of C=O and C=C groups linking together the aromatic skeleton of lignin. The 2D-IR spectra showed the appearance of 5 × 5 peak clusters in the 1000 to 1200 cm-1 region, which could account for the hemicellulose degradation. In addition, changes in the degree of sensitivity at 1627 and 1509 cm-1 coincided with cross-linking reactions among the aromatic units in the lignin molecules.

  17. 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.

  18. Potassium methyl siliconate-treated pulp fibers and their effects on wood plastic composites: Water sorption and dimensional stability

    Science.gov (United States)

    Cheng Piao; Zhiyong Cai; Nicole M. Stark; Charles J. Monlezun

    2013-01-01

    Potassium methyl siliconate (PMS) was investigated as a new nano modifier of wood fiber and wood flour to improve the compatibility between the fiber/flour and the plastic matrix in fiber reinforced plastic composites. Before injection molding, bleached and brown pulp fibers and mixed species wood flour were pretreated in PMS solutions. The morphology of the treated...

  19. Investigation of bio-composites using Novolac type liquefied wood resin: effects of liquefaction and fabrication conditions

    Science.gov (United States)

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

    2009-01-01

    Wood liquefaction using an organic solvent and an acid catalyst has long been studied as a novel technique to utilize biomass as an alternative to petroleum-based products. Oxalic acid is a weaker organic acid than a mineral acid and wood liquefaction with oxalic acid as a catalyst will result in a higher amount of wood residue than that with a mineral acid....

  20. Effect of weathering on chromated copper arsenate (CCA) treated wood : leaching of metal salts and change in water repellency

    Science.gov (United States)

    R. Sam Williams; Stan Lebow; Patricia Lebow

    2003-01-01

    Wood pressure-treated with chromated copper arsenate (CCA) wood preservative is commonly used for outdoor construction. Oxides of arsenic, copper, and chromium are bound in the wood by a complex series of chemical reactions, but a small percentage of these compounds are gradually released by leaching and weathering. Recent studies suggest that the release of these...

  1. Photostabilisation of the 'wood-clearcoatings' systems with UV absorbers: correlation with their effect on the glass transition temperature

    International Nuclear Information System (INIS)

    Aloui, F; Ahajji, A; Irmouli, Y; George, B; Charrier, B; Merlin, A

    2006-01-01

    In an application-oriented study, the effective transition temperature T g of organic wood-clearcoatings between a hard, glassy state and a viscoelastic and rubbery state is measured. The value of T g is important in the eventual development of cracks and a thermomechanical analysis is used to study the photostabilisation performance of some UV absorbers. A weathering exposure test suggests that certain organic UV absorbers have quite a low T g and may inhibit the crack formation, in contrast with inorganic UV absorbers

  2. Effects of short-term variability of meteorological variables on soil temperature in permafrost regions

    Science.gov (United States)

    Beer, Christian; Porada, Philipp; Ekici, Altug; Brakebusch, Matthias

    2018-03-01

    Effects of the short-term temporal variability of meteorological variables on soil temperature in northern high-latitude regions have been investigated. For this, a process-oriented land surface model has been driven using an artificially manipulated climate dataset. Short-term climate variability mainly impacts snow depth, and the thermal diffusivity of lichens and bryophytes. These impacts of climate variability on insulating surface layers together substantially alter the heat exchange between atmosphere and soil. As a result, soil temperature is 0.1 to 0.8 °C higher when climate variability is reduced. Earth system models project warming of the Arctic region but also increasing variability of meteorological variables and more often extreme meteorological events. Therefore, our results show that projected future increases in permafrost temperature and active-layer thickness in response to climate change will be lower (i) when taking into account future changes in short-term variability of meteorological variables and (ii) when representing dynamic snow and lichen and bryophyte functions in land surface models.

  3. Optically variable threads and polarization effects

    Science.gov (United States)

    Kretschmar, Friedrich; Burchard, Theodor; Heim, Manfred

    2006-02-01

    Based on common criteria for efficient security elements for banknotes the set-up of a state-of-the-art holographic security thread is described - as first representative of window embedded OVD. We continue with new colour-shifting OVD-threads - based on physical vapour deposition thin-film and liquid crystal technology. These three then form the family of optically variable threads following the same set of requirements for efficiency, durability, service to all authentication levels and economics. In addition to this set of OVD threads we introduce how liquid crystal based phase retarding layer can be used to install new authentication channels for the public use up-to machine authentication. Also we show the perspective how those development can be used to install similar sets of OVD families of foil elements on banknotes.

  4. 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.

  5. Effect of demographic variables on public attitudes towards ...

    African Journals Online (AJOL)

    In conclusion, background variables do have a significant effect on some of the dimensions of Malaysians' attitudes towards modern biotechnology. The research findings will be useful for understanding the effect of background variables on public attitudes towards the application of gene technology in medicine.

  6. On the Effect of Unit-Cell Parameters in Predicting the Elastic Response of Wood-Plastic Composites

    Directory of Open Access Journals (Sweden)

    Fatemeh Alavi

    2013-01-01

    Full Text Available This paper presents a study on the effect of unit-cell geometrical parameters in predicting elastic properties of a typical wood plastic composite (WPC. The ultimate goal was obtaining the optimal values of representative volume element (RVE parameters to accurately predict the mechanical behavior of the WPC. For each unit cell, defined by a given combination of the above geometrical parameters, finite element simulation in ABAQUS was carried out, and the corresponding stress-strain curve was obtained. A uniaxial test according to ASTM D638-02a type V was performed on the composite specimen. Modulus of elasticity was determined using hyperbolic tangent function, and the results were compared to the sets of finite element analyses. Main effects of RVE parameters and their interactions were demonstrated and discussed, specially regarding the inclusion of two adjacent wood particles within one unit cell of the material. Regression analysis was performed to mathematically model the RVE parameter effects and their interactions over the modulus of elasticity response. The model was finally employed in an optimization analysis to arrive at an optimal set of RVE parameters that minimizes the difference between the predicted and experimental moduli of elasticity.

  7. Sustainable wood waste management in Nigeria

    Directory of Open Access Journals (Sweden)

    Owoyemi Jacob Mayowa

    2016-09-01

    Full Text Available Wood industries produce large volumes of residues which must be utilized, marketed or properly disposed of. Heaps of wood residues are common features in wood industries throughout the year. In Nigeria, this residue is generally regarded as waste and this has led to open burning practices, dumping in water bodies or dumping in an open area which constitutes environmental pollution. Sawmills in Nigeria generated over 1,000,000 m3 of wood waste in 2010 while about 5000 m3 of waste was generated in plywood mills. Nigeria generates about 1.8 million tons of sawdust annually and 5.2 million tons of wood wastes. The impact of improper disposal of waste wood on the environment affects both the aquatic and terrestrial ecosystems. Also burning of waste wood releases greenhouse gases into the atmosphere causing various health issues. Reuse/recycling of these wood residues in Nigeria will reduce the pressure on our ever decreasing forests, reduce environmental pollution, create wealth and employment. The literature available on this subject was reviewed and this article, therefore, focuses on the various methods of wood waste disposal and its utilization in Nigerian wood industries, the effects of wood waste on the environment as well as on human health and the benefits of proper wood waste management practices.

  8. The Effect of Ultraviolet Light on the 'Liquid Wood'

    International Nuclear Information System (INIS)

    Gheorghe Asachi of Iasi, Romania, Blvd. Mangeron, No. 59A, 700050 Iasi (Romania))" data-affiliation=" (Technical University Gheorghe Asachi of Iasi, Romania, Blvd. Mangeron, No. 59A, 700050 Iasi (Romania))" >Dumitru, Nedelcu; Gheorghe Asachi of Iasi, Romania, Blvd. Mangeron, No. 59A, 700050 Iasi (Romania))" data-affiliation=" (Technical University Gheorghe Asachi of Iasi, Romania, Blvd. Mangeron, No. 59A, 700050 Iasi (Romania))" >Constantin, Cǎrausu; Sabina, Zǎgan; Ticuta, Negreanu-Pirjol; Remus, Zǎgan

    2014-01-01

    To preserve resources, the goal is to use biobased materials containing the maximum possible amount of renewable biomass-based derivatives to secure a sustainable future. Bioplastics, biocomposites, biological fibres and related biomaterials will serve as substitutes for materials and products traditionally made from petroleum resources. To support this need, in 1998, Fraunhofer Institute of Chemistry and Tecnaro GmbH Company (founded by Jurgen Pfitzer and Helmut Nagele in Germany) investigated and developed a new compound made of wood components that can be processed as a thermoplastic material. It is well known that bioplastic and biocomposite materials represent another important group of bio-materials that include plastics reinforced with natural fibers and wood-plastic composites (WPCs). The aim of this research is to identify the behavior of 'Liquid Wood' after UV irradiation. The materials used were Arbofill Fichte, Arboblend V2 Nature and Arboform L, V3 Nature. The samples were obtained by injection and the experimental study plan followed the Taguchi method with six input parameters and two levels for each of them. Three samples from each material were tested in an ultraviolet environment using different time of exposure in order to establish the material characteristics. After the irradiation process the material did not turn to yellow, which suggests that the composition of the sample liquid timber inhibitors have stability and the number of α-carbonyl (C = O) groups is sufficiently low. After the graphs analyzing can be inferred relatively similar performance of the samples in the first stage both UV and the VIS, indicating that the activity is almost absent. In UV is clearly observed the peak amplitude (maximum absorbance) at different wavelengths (λ). So, in terms of peak intensity the samples follow the order: Arboform L, V3 Nature; Arbofill Fichte and Arboblend V2 Nature

  9. THE EFFECTS OF CLIMATIC VARIABLES AND CROP AREA ON MAIZE YIELD AND VARIABILITY IN GHANA

    Directory of Open Access Journals (Sweden)

    Henry De-Graft Acquah

    2012-10-01

    Full Text Available Climate change tends to have negative effects on crop yield through its influence on crop production. Understanding the relationship between climatic variables and crop area on the mean and variance of crop yield will facilitate development of appropriate policies to cope with climate change. This paper examines the effects of climatic variables and crop area on the mean and variance of maize yield in Ghana. The Just and Pope stochastic production function using the Cobb-Douglas functional form was employed. The results show that average maize yield is positively related to crop area and negatively related to rainfall and temperature. Furthermore, increase in crop area and temperature will enlarge maize yield variability while rainfall increase will decrease the variability in maize yield.

  10. Water repellents and water-repellent preservatives for wood

    Science.gov (United States)

    R. Sam. Williams; William C. Feist

    1999-01-01

    Water repellents and water-repellent preservatives increase the durability of wood by enabling the wood to repel liquid water. This report focuses on water-repellent finishes for wood exposed outdoors above ground. The report includes a discussion of the effects of outdoor exposure on wood, the characteristics of water repellent and water-repellent preservative...

  11. Greenhouse effects of the peat production and use as compared to coal, oil, natural gas and wood

    International Nuclear Information System (INIS)

    Hillebrand, K.; Wihersaari, M.

    1993-01-01

    This report examines the greenhouse effects of greenhouse gas emissions (carbon dioxide, methane and nitrous oxide) arising from certain production and utilization chains of peat and compares them with the corresponding effects associated with the production and utilization chains of coal, oil, natural gas and wood. In order to estimate the greenhouse effects of the peat production and utilization chains, the initial state of the peat bog together with the instantaneous and cumulative greenhouse effects associated with the production and burning of peat as well as subsequent use of the production area were taken into account. The initial state of the peat bog was taken to be either a bog in its natural sale, a forest-drained bog or a cultivated peatland. As regards alternatives for subsequent use of the peat production area, afforestation, paludification and lake formation were all examined

  12. Design of an Advanced Wood Composite Rotor and Development of Wood Composite Blade Technology

    Science.gov (United States)

    Stroebel, Thomas; Dechow, Curtis; Zuteck, Michael

    1984-01-01

    In support of a program to advance wood composite wind turbine blade technology, a design was completed for a prototype, 90-foot diameter, two-bladed, one-piece rotor, with all wood/epoxy composite structure. The rotor was sized for compatibility with a generator having a maximum power rating of 4000 kilowatts. Innovative features of the rotor include: a teetering hub to minimize the effects of gust loads, untwisted blades to promote rotor power control through stall, joining of blades to the hub structure via an adhesive bonded structural joint, and a blade structural design which was simplified relative to earlier efforts. The prototype rotor was designed to allow flexibility for configuring the rotor upwind or downwind of the tower, for evaluating various types of teeter dampers and/or elastomeric stops, and with variable delta-three angle settings of the teeter shaft axis. The prototype rotor was also designed with provisions for installing pressure tap and angle of attack instrumentation in one blade. A production version rotor cost analysis was conducted. Included in the program were efforts directed at developing advanced load take-off stud designs for subsequent evaluation testing by NASA, development of aerodynamic tip brake concepts, exploratory testing of a wood/epoxy/graphite concept, and compression testing of wood/epoxy laminate, with scarf-jointed plies.

  13. Steam-explosion pretreatment of wood: effect of chip size, acid, moisture content and pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Brownell, H.H.; Yu, E.K.C.; Saddler, J.N.

    1986-06-01

    Material balances for pentosan, lignin, and hexosan, during steam-explosion pretreatment of aspenwood, showed almost quantitative recovery of cellulose in the water-insoluble fraction. Dilute acid impregnation resulted in more selective hydrolysis of pentosan relative to undesirable pyrolysis, and gave a more accessible substrate for enzymatic hydrolysis. Thermocouple probes, located inside simulated aspenwood chips heated in 240 degrees C-saturated steam, showed rapid heating of air-dry wood, whereas green or impregnated wood heated slowly. Small chips, 3.2 mm in the fiber direction, whether green or air dry gave approximately equal rates of pentosan destruction and solubilization, and similar yields of glucose and of total reducing sugars on enzmatic hydrolysis with Trichoderma harzianum. Partial pyrolysis, destroying one-third of the pentosan of aspenwood at atmospheric pressure by dry steam at 276 degrees C, gave little increase in yield of reducing sugars on enzymatic hydrolysis. Treatment with saturated steam at 240 degrees C gave essentially the same yields of butanediol and ethanol on fermentation with Klebsiella pneumoniae, whether or not 80% of the steam was bled off before explosion and even if the chips remained intact, showing that explosion was unnecessary. 17 references.

  14. The Effect of Soil Warming on Decomposition of Biochar, Wood, and Bulk Soil Organic Carbon in Contrasting Temperate and Tropical Soils

    Science.gov (United States)

    Torn, Margaret; Tas, Neslihan; Reichl, Ken; Castanha, Cristina; Fischer, Marc; Abiven, Samuel; Schmidt, Michael; Brodie, Eoin; Jansson, Janet

    2013-04-01

    Biochar and wood are known to decay at different rates in soil, but the longterm effect of char versus unaltered wood inputs on soil carbon dynamics may vary by soil ecosystem and by their sensitivity to warming. We conducted an incubation experiment to explore three questions: (1) How do decomposition rates of char and wood vary with soil type and depth? (2) How vulnerable to warming are these slowly decomposing inputs? And (3) Do char or wood additions increase loss of native soil organic carbon (priming)? Soils from a Mediterranean grassland (Hopland Experimental Research Station, California) and a moist tropical forest (Tabunoco Forest, Puerto Rico) were collected from two soil depths and incubated at ambient temperature (14°C, 20°C for Hopland and Tabonuco respectively) and ambient +6°C. We added 13C-labeled wood and char (made from the wood at 450oC) to the soils and quantified CO2 and 13CO2 fluxes with continuous online carbon isotope measurements using a Cavity Ringdown Spectrometer (Picarro, Inc) for one year. As expected, in all treatments the wood decomposed much (about 50 times) more quickly than did the char amendment. With few exceptions, amendments placed in the surface soil decomposed more quickly than those in deeper soil, and in forest soil faster than that placed in grassland soil, at the same temperature. The two substrates were not very temperature sensitive. Both had Q10 less than 2 and char decomposition in particular was relatively insensitive to warming. Finally, the addition of wood caused a significant increase of roughly 30% in decomposition losses of the native soil organic carbon in the grassland and slightly less in forest. Char had only a slight positive priming effect but had a significant effect on microbial community. These results show that conversion of wood inputs to char through wildfire or intentional management will alter not only the persistence of the carbon in soil but also its temperature response and effect on

  15. Age trends and within-site effects in wood density and radial growth in Quercus faginea mature trees

    Directory of Open Access Journals (Sweden)

    Vicelina B. Sousa

    2016-04-01

    Full Text Available Aim of the study: This paper aims to valorize the wood of Quercus faginea Lam. for high quality end uses (e.g. furniture by studying growth and quality properties using mature trees. Age trends in tree-ring width and wood density are shown and the main factors responsible for variations in tree-ring width and wood density within and between trees are investigated. Area of study: The study site is in the center of Portugal within the natural species distribution area.Material and methods: Radial samples from ten mature trees were collected at 6 heights (from base to 9.7 m and prepared for X-ray microdensity.Main results: Wood density showed high values, ranging from 0.868 g/cm3 to 0.957 g/cm3. Wood density decreased from pith to bark and with stem height. Cambial age showed a linear relationship with wood density and most of the variation in wood is explained by age. Intra-ring and axial within-tree homogeneity was good.Research highlights: Mature trees of Q. faginea showed high wood density and a high potential for high quality end uses, comparable to other oaks. Wood density is influenced by cambial age and tree-ring width. Wood quality may be improved by tree growth rates adjustment e.g. through an adequate tree stand density (e.g. thinning operations. 

  16. Age trends and within-site effects in wood density and radial growth in Quercus faginea mature trees

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, V.B.; Louzada, J.L.; Pereira, H.

    2016-07-01

    Aim of study: This paper aims to valorize the wood of Quercus faginea Lam. for high quality end uses (e.g. furniture) by studying growth and quality properties using mature trees. Age trends in tree-ring width and wood density are shown and the main factors responsible for variations in tree-ring width and wood density within and between trees are investigated. Area of study: The study site is in the center of Portugal within the natural species distribution area. Material and methods: Radial samples from ten mature trees were collected at 6 heights (from base to 9.7 m) and prepared for X-ray microdensity. Main results: Wood density showed high values, ranging from 0.868 g/cm3 to 0.957 g/cm3. Wood density decreased from pith to bark and with stem height. Cambial age showed a linear relationship with wood density and most of the variation in wood is explained by age. Intra-ring and axial within-tree homogeneity was good. Research highlights: Mature trees of Q. faginea showed high wood density and a high potential for high quality end uses, comparable to other oaks. Wood density is influenced by cambial age and tree-ring width. Wood quality may be improved by tree growth rates adjustment e.g. through an adequate tree stand density (e.g. thinning operations). (Author)

  17. Age trends and within-site effects in wood density and radial growth in Quercus faginea mature trees

    International Nuclear Information System (INIS)

    Sousa, V.B.; Louzada, J.L.; Pereira, H.

    2016-01-01

    Aim of study: This paper aims to valorize the wood of Quercus faginea Lam. for high quality end uses (e.g. furniture) by studying growth and quality properties using mature trees. Age trends in tree-ring width and wood density are shown and the main factors responsible for variations in tree-ring width and wood density within and between trees are investigated. Area of study: The study site is in the center of Portugal within the natural species distribution area. Material and methods: Radial samples from ten mature trees were collected at 6 heights (from base to 9.7 m) and prepared for X-ray microdensity. Main results: Wood density showed high values, ranging from 0.868 g/cm3 to 0.957 g/cm3. Wood density decreased from pith to bark and with stem height. Cambial age showed a linear relationship with wood density and most of the variation in wood is explained by age. Intra-ring and axial within-tree homogeneity was good. Research highlights: Mature trees of Q. faginea showed high wood density and a high potential for high quality end uses, comparable to other oaks. Wood density is influenced by cambial age and tree-ring width. Wood quality may be improved by tree growth rates adjustment e.g. through an adequate tree stand density (e.g. thinning operations). (Author)

  18. 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.

  19. 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...

  20. 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...

  1. Effective Remediation of Lead Ions from Aqueous Solution by Chemically Carbonized Rubber Wood Sawdust: Equilibrium, Kinetics, and Thermodynamic Study

    Directory of Open Access Journals (Sweden)

    Swarup Biswas

    2015-01-01

    Full Text Available Rubber wood sawdust was carbonized into charcoal by chemical treatment which was used for removal of lead ion from aqueous solution. The work involves batch experiments to investigate the pH effect, initial concentration of adsorbate, contact time, and adsorbent dose. Experimental data confirmed that the adsorption capacities increased with increasing inlet concentration and bed height and decreased with increasing flow rate. Adsorption results showed a maximum adsorption capacity of 37 mg/g at 308 K. Langmuir, Freundlich, and Temkin model adsorption isotherm models were applied to analyze the process where Temkin was found as a best fitted model for present study. Simultaneously kinetics of adsorption like pseudo-first-order, pseudo-second-order, and intraparticle diffusion models were investigated. Thermodynamic parameters were used to analyze the adsorption experiment. Fourier transform infrared spectroscopy, scanning electron microscope, and energy dispersive X-ray spectroscopy confirmed the batch adsorption of lead ion onto chemically carbonized rubber wood sawdust.

  2. Effects of interacting variables on the release properties of ...

    African Journals Online (AJOL)

    Purpose: The individual and interaction effects of formulation variables on the release of suppositories were investigated using a 23 factorial experimental design. The variables studied were nature of base (B), type of drug (D), and presence of surfactant (S). Method: Suppositories were formulated with theobroma oil and ...

  3. A geographical analysis of the Swedish wood fuel market

    International Nuclear Information System (INIS)

    Roos, Anders; Bohlin, Folke; Hektor, Bo; Hillring, Bengt; Parikka, Matti

    2000-01-01

    The geographical variation in Swedish wood fuel market characteristics for the district heating sector has been studied using Geographical Information Systems (GIS) and cross-sectional Tobit analysis. The results indicate that local availability and competition for wood fuels influence the wood fuel consumption at inland heating plants. The factors affecting the decision to use wood fuel at heating plants close to seaports, however, were not captured by the model, suggesting that coastal location reduces dependency on the local wood fuel market. The effects of changes in local wood fuel availability on wood fuel use by an inland heating plant are presented and discussed

  4. Effects of practice variability on unimanual arm rotation.

    Science.gov (United States)

    James, Eric G; Conatser, Phillip

    2014-01-01

    High variability practice has been found to lead to a higher rate of motor learning than low variability practice in sports tasks. The authors compared the effects of low and high levels of practice variability on a simple unimanual arm rotation task. Participants performed rhythmic unimanual internal-external arm rotation as smoothly as possible before and after 2 weeks of low (LV) or high (HV) variability practice and after a 2-week retention interval. Compared to the pretest, the HV group significantly decreased hand, radioulnar, and shoulder rotation jerk on the retention test and shoulder jerk on the posttest. After training the LV group had lower radioulnar and shoulder jerk on the posttest but not the retention test. The results supported the hypothesis that high variability practice would lead to greater learning and reminiscence than low variability practice and the theoretical prediction of a bifurcation in the motor learning dynamics.

  5. Wood pellets : a worldwide fuel commodity

    International Nuclear Information System (INIS)

    Melin, S.

    2005-01-01

    Aspects of the wood pellet industry were discussed in this PowerPoint presentation. Details of wood pellets specifications were presented, and the wood pellet manufacturing process was outlined. An overview of research and development activities for wood pellets was presented, and issues concerning quality control were discussed. A chart of the effective calorific value of various fuels was provided. Data for wood pellet mill production in Canada, the United States and the European Union were provided, and various markets for Canadian wood pellets were evaluated. Residential sales as well as Canadian overseas exports were reviewed. Production revenues for British Columbia and Alberta were provided. Wood pellet heat and electricity production were discussed with reference to prefabricated boilers, stoves and fireplaces. Consumption rates, greenhouse gas (GHG) emissions, and fuel ratios for wood pellets and fossil fuels were compared. Price regulating policies for electricity and fossil fuels have prevented the domestic expansion of the wood pellet industry. There are currently no incentives for advanced biomass combustion to enter British Columbia markets, and this has led to the export of wood pellets. It was concluded that climate change mitigation policies will be a driving force behind market expansion for wood pellets. tabs., figs

  6. Interactive Effects of Climate Change and Decomposer Communities on the Stabilization of Wood-Derived Carbon Pools: Catalyst for a New Study

    Energy Technology Data Exchange (ETDEWEB)

    Resh, Sigrid C. [Michigan Technological Univ., Houghton, MI (United States)

    2014-11-17

    > m-2 h-1, respectively; p = 0.068). Our first two growing seasons of soil surface CO2 efflux data show that wood chip location (i.e., surface vs. buried chip application) is very important, with surface chips loosing twice the wood-derived CO2. The DOC data support this trend for greater loss of ecosystem C from surface chips. This has strong implications for the importance of root and buried wood for ecosystem C retention. This strong chip location effect on wood-derived C loss was significantly modified by soil texture, soil temperature, decomposer communities, and wood quality as effected by potential future CO2 and O3 levels.

  7. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R. [Universidad Central de Venezuela, Caracas (Venezuela). Escuela de Quimica; Gonzalez, J.; Ichazo, M. [Universidad Simon Bolivar, Dept. de Mecanica, Caracas (Venezuela); Chipara, M. [Research Institute for Electrotechnics, Bucharest (Romania)

    2001-04-01

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  8. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    International Nuclear Information System (INIS)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R.; Chipara, M.

    2001-01-01

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  9. Effect of carbonization temperature on the microplasticity of wood-derived biocarbon

    Science.gov (United States)

    Shpeizman, V. V.; Orlova, T. S.; Kardashev, B. K.; Smirnov, B. I.; Gutierrez-Pardo, A.; Ramirez-Rico, J.

    2014-03-01

    The uniaxial compression strength under stepped loading and the 325-nm-stepped deformation rate of biocarbon samples obtained by carbonization of beech wood at different temperatures in the 600-1600°C range have been measured using high-precision interferometry. It has been shown that the strength depends on the content of nanocrystalline phase in biocarbon. The magnitude of deformation jumps at micro- and nanometer levels and their variation with a change in the structure of the material and loading time have been determined. For micro- and nanometer-scale jumps, standard deviations of the differences between the experimentally measured deformation rate at loading steps and its magnitude at the smoothed fitting curve have been calculated, and the correlation of the error with the deformation prior to destruction has been shown. The results obtained have been compared with the previously published data on measurements of the elastic properties and internal friction of these materials.

  10. 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.

  11. How spectroscopy and microspectroscopy of degraded wood contribute to understand fungal wood decay.

    Science.gov (United States)

    Fackler, Karin; Schwanninger, Manfred

    2012-11-01

    Nuclear magnetic resonance, mid and near infrared, and ultra violet (UV) spectra of wood contain information on its chemistry and composition. When solid wood samples are analysed, information on the molecular structure of the lignocellulose complex of wood e.g. crystallinity of polysaccharides and the orientation of the polymers in wood cell walls can also be gained. UV and infrared spectroscopy allow also for spatially resolved spectroscopy, and state-of-the-art mapping and imaging systems have been able to provide local information on wood chemistry and structure at the level of wood cells (with IR) or cell wall layers (with UV). During the last decades, these methods have also proven useful to follow alterations of the composition, chemistry and physics of the substrate wood after fungi had grown on it as well as changes of the interactions between the wood polymers within the lignocellulose complex caused by decay fungi. This review provides an overview on how molecular spectroscopic methods could contribute to understand these degradation processes and were able to characterise and localise fungal wood decay in its various stages starting from the incipient and early ones even if the major share of research focussed on advanced decay. Practical issues such as requirements in terms of sample preparation and sample form and present examples of optimised data analysis will also be addressed to be able to detect and characterise the generally highly variable microbial degradation processes within their highly variable substrate wood.

  12. Study of the effect of ionizing radiation on composites of wood flour in polypropylene matrix using barium titanate as coupling agent

    International Nuclear Information System (INIS)

    Ulloa, Maritza Eliza Perez

    2007-01-01

    The purpose of this work was to study the effects of ionizing radiation on the properties of wood flour composites in polypropylene matrix, using barium titanate as a coupling agent and the reactive monomer tripropylene glycol diacrylate (TPDGA). An electron accelerator was used in the study as the radiation source. The physical properties of virgin compounds and of the polypropylene/wood flour composite, with and without barium titanate and TPDGA addition, were investigated. The composites were developed from the load treatment, which first consisted of incorporating additives to the wood flour reinforcement and after that, the fusion process of polypropylene and composite mixing in a 'calander'. Subsequently, the samples to be irradiated and submitted to thermal and mechanical assays were molded by injection. The mechanical properties (hardness, impact resistance and molten fluidity index (MFI)), as well as the thermal properties (HDT and Vicat) of the composites were determined. The investigated compositions consisted of polypropylene/wood flour, polypropylene/wood flour with barium titanate and polypropylene/wood flour with barium titanate and TPDGA, using different wood flour concentrations of 10 por cent, 15 por cent and 20 por cent in the polypropylene matrix. The samples were separated in groups and irradiated to doses of 10 kGy and 20 kGy in the samples of the essays of traction. Besides these doses, it was also used doses of 15 kGy and 25 kGy to be observed the behavior of the sample of the sample due to the increase of the radiation. These doses were chosen to show that with low doses the composite material presents reticulation, what represents a viable commercial option. There was a reduction of the flow rate for the composites containing wood flour, being this reduction more effective in the presence of TiBa. The superficial treatment using TPDGA monomer influence in the composite samples because it acted as a plastic additive becoming the sample

  13. Wood ash or dolomite treatment of catchment areas - effects of mercury in runoff water

    Energy Technology Data Exchange (ETDEWEB)

    Parkman, H; Munthe, J [Swedish Environmental Research Inst., Stockholm (Sweden)

    1996-11-01

    A future increased use of biomass as a source of energy, and the planned restoration of mineral nutrient balance in the forest soils by returning the wood ashes, has led to concern for new environmental disturbances. The objectives of the present study were to investigate if the outflow of total mercury (TotHg) and methyl mercury (MeHg) from catchment areas treated with granulated wood ash (1988, 2.2 tons/ha, `ashed area`) or dolomite (1985, 5 tons/ha, `limed area`) differed from the outflow from an untreated (reference) area, and if variations in Hg outflow were correlated with changes in the outflow of organic substances or pH. The study areas are situated in Vaermland, Sweden. Samples of run-off water were taken weekly or monthly (depending on water-flow) during on year (1993-94). The outflow of MeHg, TotHg as well as H+ and dissolved organic material (DOC) was lower from the limed area compared to the other two areas, which did not differ significantly. There was a strong covariation between concentrations of DOC and MeHg and a weaker relation between DOC and TotHg in the run-off waters. MeHg also covaried with temperature while TotHg covaried with pH and water-supply. No difference was found when comparing Hg-data from the limed area before, directly after and eight years after the liming event. 13 refs, 12 figs, 1 tab

  14. 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...

  15. A study on the effect of macroeconomic variables and firm ...

    African Journals Online (AJOL)

    A study on the effect of macroeconomic variables and firm characteristics on the quality of financial reporting of listed firms in Tehran Stock Exchange. ... Journal of Fundamental and Applied Sciences. Journal Home · ABOUT THIS JOURNAL ...

  16. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal; Ali, Hussnain; Majeed, S. M Imran; Khan, Shoab A.

    2011-01-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal

  17. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Pesek, M.; Dedek, V.; Plander, E.

    1975-01-01

    Wood is impregnated with vinyl monomers in a solution of organic solvents and in the presence of a swelling agent. The impregnation mixture contains a diolefinic hydrocarbon and/or a solid chlorinated or bromated compound with the melting point exceeding 30 degC and less than 10 % of an organosilicon compound. Polymerization is effected by ionizing radiation and a subsequent action of temperature in a range of 40 to 150 JegC. (B.S.)

  18. 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.

  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. The effect of virtual reality on gait variability.

    Science.gov (United States)

    Katsavelis, Dimitrios; Mukherjee, Mukul; Decker, Leslie; Stergiou, Nicholas

    2010-07-01

    Optic Flow (OF) plays an important role in human locomotion and manipulation of OF characteristics can cause changes in locomotion patterns. The purpose of the study was to investigate the effect of the velocity of optic flow on the amount and structure of gait variability. Each subject underwent four conditions of treadmill walking at their self-selected pace. In three conditions the subjects walked in an endless virtual corridor, while a fourth control condition was also included. The three virtual conditions differed in the speed of the optic flow displayed as follows--same speed (OFn), faster (OFf), and slower (OFs) than that of the treadmill. Gait kinematics were tracked with an optical motion capture system. Gait variability measures of the hip, knee and ankle range of motion and stride interval were analyzed. Amount of variability was evaluated with linear measures of variability--coefficient of variation, while structure of variability i.e., its organization over time, were measured with nonlinear measures--approximate entropy and detrended fluctuation analysis. The linear measures of variability, CV, did not show significant differences between Non-VR and VR conditions while nonlinear measures of variability identified significant differences at the hip, ankle, and in stride interval. In response to manipulation of the optic flow, significant differences were observed between the three virtual conditions in the following order: OFn greater than OFf greater than OFs. Measures of structure of variability are more sensitive to changes in gait due to manipulation of visual cues, whereas measures of the amount of variability may be concealed by adaptive mechanisms. Visual cues increase the complexity of gait variability and may increase the degrees of freedom available to the subject. Further exploration of the effects of optic flow manipulation on locomotion may provide us with an effective tool for rehabilitation of subjects with sensorimotor issues.

  1. Natural Protection of Wood with Antagonism Fungi

    Directory of Open Access Journals (Sweden)

    Alba ZAREMSKI

    2011-03-01

    Full Text Available Biological environments contain a certain number of microbial populations which, within a givenecological niche, display various relations ranging from symbiosis to parasitism. Researchers have beeninterested in these types of relations for around fifty years, especially in one very particular type ofrelationship: the antagonism exerted between individuals of the same microbial population.Today, the role played by biological agents, bringing into play inhibitive or destructive antibioticsubstances, reveals a certain potential for their use in controlling microorganisms associated with suchdegradation processes.The work undertaken by HydroQuébec and CIRAD involved two types of experiment: 1 in Petri dishes toassess and characterize the antagonistic capacity of Trichoderma against white rot and brown rot fungi; 2on pieces taken from untreated poles in order to study confrontation between the basidiomycete and theantagonistic strain in wood.This study investigated the antagonism of three ascomycetes of the genus Trichoderma against two whiterot basidiomycetes, Pycnoporus sanguineus and Coriolus versicolor, and two brown rot basidiomycetes,Antrodia sp. and Coniophora puteana, through direct confrontation in Petri dishes and in the wood ofHydroQuébec poles.The results obtained seemed to complete each other coherently. They revealed that the Trichodermagroup of fungi was not aggressive to wood and the results obtained after direct confrontation in Petri disheswere confirmed in wood.By directly exposing the different basidiomycetes and antagonists to each other in Petri dishes, two bytwo, we effectively revealed an antagonism effect for a large majority of the pairs. However, there wassubstantial variability in reactions from one pair to the next.

  2. Integrated control of wood destroying basidiomycetes combining Cu-based wood preservatives and Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Javier Ribera

    Full Text Available The production of new generation of wood preservatives (without addition of a co-biocide in combination with an exchange of wood poles on identical sites with high fungal inoculum, has resulted in an increase of premature failures of wood utility poles in the last decades. Wood destroying basidiomycetes inhabiting sites where poles have been installed, have developed resistance against wood preservatives. The objective of the in vitro studies was to identify a Trichoderma spp. with a highly antagonistic potential against wood destroying basidiomycetes that is capable of colonizing Cu-rich environments. For this purpose, the activity of five Trichoderma spp. on Cu-rich medium was evaluated according to its growth and sporulation rates. The influence of the selected Trichoderma spp. on wood colonization and degradation by five wood destroying basidiomycetes was quantitatively analyzed by means of dry weight loss of wood specimens. Furthermore, the preventative effect of the selected Trichoderma spp. in combination with four Cu-based preservatives was also examined by mass loss and histological changes in the wood specimens. Trichoderma harzianum (T-720 was considered the biocontrol agent with higher antagonistic potential to colonize Cu-rich environments (up to 0.1% CuSO4 amended medium. T. harzianum demonstrated significant preventative effect on wood specimens against four wood destroying basidiomycetes. The combined effect of T. harzianum and Cu-based wood preservatives demonstrated that after 9 months incubation with two wood destroying basidiomycetes, wood specimens treated with 3.8 kg m-3 copper-chromium had weight losses between 55-65%, whereas containers previously treated with T. harzianum had significantly lower weight losses (0-25%. Histological studies on one of the wood destroying basidiomycetes revealed typical decomposition of wood cells by brown-rot fungi in Cu-impregnated samples, that were notably absent in wood specimens

  3. Integrated control of wood destroying basidiomycetes combining Cu-based wood preservatives and Trichoderma spp.

    Science.gov (United States)

    Ribera, Javier; Fink, Siegfried; Bas, Maria Del Carmen; Schwarze, Francis W M R

    2017-01-01

    The production of new generation of wood preservatives (without addition of a co-biocide) in combination with an exchange of wood poles on identical sites with high fungal inoculum, has resulted in an increase of premature failures of wood utility poles in the last decades. Wood destroying basidiomycetes inhabiting sites where poles have been installed, have developed resistance against wood preservatives. The objective of the in vitro studies was to identify a Trichoderma spp. with a highly antagonistic potential against wood destroying basidiomycetes that is capable of colonizing Cu-rich environments. For this purpose, the activity of five Trichoderma spp. on Cu-rich medium was evaluated according to its growth and sporulation rates. The influence of the selected Trichoderma spp. on wood colonization and degradation by five wood destroying basidiomycetes was quantitatively analyzed by means of dry weight loss of wood specimens. Furthermore, the preventative effect of the selected Trichoderma spp. in combination with four Cu-based preservatives was also examined by mass loss and histological changes in the wood specimens. Trichoderma harzianum (T-720) was considered the biocontrol agent with higher antagonistic potential to colonize Cu-rich environments (up to 0.1% CuSO4 amended medium). T. harzianum demonstrated significant preventative effect on wood specimens against four wood destroying basidiomycetes. The combined effect of T. harzianum and Cu-based wood preservatives demonstrated that after 9 months incubation with two wood destroying basidiomycetes, wood specimens treated with 3.8 kg m-3 copper-chromium had weight losses between 55-65%, whereas containers previously treated with T. harzianum had significantly lower weight losses (0-25%). Histological studies on one of the wood destroying basidiomycetes revealed typical decomposition of wood cells by brown-rot fungi in Cu-impregnated samples, that were notably absent in wood specimens previously exposed to T

  4. A nematicidal tannin from Punica granatum L. rind and its physiological effect on pine wood nematode (Bursaphelenchus xylophilus).

    Science.gov (United States)

    Guo, Qunqun; Du, Guicai; Qi, Hongtao; Zhang, Yanan; Yue, Tongqing; Wang, Jingchao; Li, Ronggui

    2017-01-01

    The ethanol extract of Punica granatum L. rind was tested to show significant nematicidal activity against pine wood nematode. Three nematicidal compounds were obtained from the ethanol extract by bioassay-guided fractionation and identified as punicalagin 1, punicalin 2, and corilagin 3 by mass and nuclear magnetic resonance spectral data analysis. Punicalagin 1 was most active against PWN among the purified compounds with the LC 50 value of 307.08μM in 72h. According to the enzyme assays in vitro, punicalagin 1 could inhibit the activity of acetylcholinesterase, amylase and cellulase from PWN with IC 50 value of 0.60mM, 0.96mM and 1.24mM, respectively. The morphological structures of PWNs treated by punicalagin 1 were greatly changed. These physiological effects of punicalagin 1 on PWN may helpful to elucidate its nematicidal mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Falsification Testing of Instrumental Variables Methods for Comparative Effectiveness Research.

    Science.gov (United States)

    Pizer, Steven D

    2016-04-01

    To demonstrate how falsification tests can be used to evaluate instrumental variables methods applicable to a wide variety of comparative effectiveness research questions. Brief conceptual review of instrumental variables and falsification testing principles and techniques accompanied by an empirical application. Sample STATA code related to the empirical application is provided in the Appendix. Comparative long-term risks of sulfonylureas and thiazolidinediones for management of type 2 diabetes. Outcomes include mortality and hospitalization for an ambulatory care-sensitive condition. Prescribing pattern variations are used as instrumental variables. Falsification testing is an easily computed and powerful way to evaluate the validity of the key assumption underlying instrumental variables analysis. If falsification tests are used, instrumental variables techniques can help answer a multitude of important clinical questions. © Health Research and Educational Trust.

  6. Management alternatives of energy wood thinning stands

    International Nuclear Information System (INIS)

    Heikkilae, Jani; Siren, Matti; Aeijaelae, Olli

    2007-01-01

    Energy wood thinning has become a feasible treatment alternative of young stands in Finland. Energy wood thinnings have been carried out mainly in stands where precommercial thinning has been neglected and the harvesting conditions for industrial wood thinning are difficult. Despite of its positive effects on harvesting costs and on renewable energy potential, whole-tree harvesting has been constantly criticized for causing growth loss. In this paper, the profitability of energy wood thinning was studied in 20 Scots pine-dominated stands where energy wood thinning was carried out. The growth of the stands after thinning was predicted with the help of Motti-stand simulator. Entire rotation time of the stands was simulated with different management alternatives. The intensity of first thinning and recovery level of logging residues varied between alternatives. In order to attain acceptable harvesting conditions, industrial wood thinning had to be delayed. The effect of energy wood thinning on subsequent stem wood growth was almost the same as in conventional thinning. Whole-tree harvesting for energy proved to be profitable alternative if the stumpage price is around 3EUR m -3 , the interest rate is 3% or 5% and the removal of pulpwood is less than 20 m 3 ha -1 . If the harvestable pulpwood yield is over 20 m 3 ha -1 , integrated harvesting of industrial and energy wood or delayed industrial wood harvesting becomes more profitable. (author)

  7. 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...

  8. Effect of elliptic or circular holes on the stress distribution in plates of wood or plywood considered as orthotropic materials

    Science.gov (United States)

    C. B. Smith

    1944-01-01

    This is a mathematical analysis of the stress distribution existing near a hole in a wood or plywood plate subjected to tension, as, for example, near holes in the tension flanges of wood box beams. It is assumed that the strains are small and remain within the proportional limit. In this analysis a large, rectangular, orthotropic plate with a small elliptic hole at...

  9. 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...

  10. Comparative analysis of the effect of pretreating aspen wood with aqueous and aqueous-organic solutions of sulfuric and nitric acid on its reactivity during enzymatic hydrolysis

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Osipov, D. O.; Zorov, I. N.

    2016-01-01

    The effect of aspen wood pretreatment methods with the use of both aqueous solutions of sulfuric and nitric acids and aqueous-organic solutions (ethanol, butanol) of sulfuric acid (organosolv) on the limiting degree of conversion of this type of raw material into simple sugars during enzymatic...

  11. Effect of moisture availability on wood density and vessel characteristics of Eucalyptus grandis in the warm temperate region of South Africa

    CSIR Research Space (South Africa)

    Naidoo, Sasha

    2006-09-01

    Full Text Available intolerant of adverse conditions, and performs poorly when planted on shallow soils and/or on dry sites. A study was conducted to assess the effect of moisture availability on the wood density and vessel characteristics of E. grandis grown in the warm...

  12. The effects of a western spruce budworm outbreak on the dead wood component in relation to ownership in forests of eastern Oregon

    Science.gov (United States)

    David. Azuma

    2010-01-01

    Forest Inventory and Analysis data were used to investigate the effects of a severe western spruce budworm outbreak on the dead wood component of forests in 11 counties of eastern Oregon for two time periods. The ownership and the level of damage (as assessed by aerial surveys) affected the resulting down woody material and standing dead trees. The pattern of coarse...

  13. Health aspects of wood particles in fugitive emission during professional exposition

    International Nuclear Information System (INIS)

    Vlckova, H.; Schwarz, M.; Lalik, V.

    2008-01-01

    Fugitive emission of wood dust can constitute serious menace to health of worker in wood industry. Present paper describes not only influence of unaccompanied wood which develops allergic reactions, respire diseases, dermatosis, cancer etc., but also additional effects of natural wood components as endotoxins, microbial spores, amoebas, fungus, animal and proteins, volatile components wood resins, respectively. (authors)

  14. Bond quality of phenol-based adhesives containing liquefied creosote-treated wood

    Science.gov (United States)

    Chung-Yun Hse; Feng Fu; Hui Pan

    2009-01-01

    Liquefaction of spent creosote-treated wood was studied to determine the technological practicability of its application in converting treated wood waste into resin adhesives. A total of 144 plywood panels were fabricated with experimental variables included 2 phenol to wood (P/W) ratios in liquefaction, 6 resin formulations (3 formaldehyde/liquefied wood (F/...

  15. Effects of oil sands waste water on the wood frog (rana sylvatica)

    Energy Technology Data Exchange (ETDEWEB)

    Hersikorn, B.; Smits, J.E. [Saskatchewan Univ., Regina, SK (Canada)

    2007-07-01

    The sustainability of various reclamation strategies can be determined by the growth and health of indigenous amphibians (Wood Frogs). This paper referred to the large quantities of tailings water that are generated by oil sand extraction activities. It presented the results of a study that was conducted in the spring and summer of 2006 and 2007 on reclaimed formation wetlands comprising tailings water. The objective was to understand the impact of these wetlands on native amphibians. Frogs were exposed to wetlands containing oil sands process affected water (OSPW) and reference water (no OSPW). Six experimental trenches were made at one site in the first year. Each trench had 3 enclosures with 50 tadpoles. In the second year, there were 13 sites, including 6 reference and 7 OSPW affected sites, which were classified as old (more than 8 yrs) or young (less than 7 yrs). Four enclosures, with 50 tadpoles each, were placed in each wetland. The study involved the evaluation of growth rate, survival, time to metamorphosis, thyroid hormone concentrations, liver EROD activity, and tissue retinol concentrations. In addition, stable isotopes were used to track carbon flow from primary production plants, through the food chain, to tadpoles and frogs which represent intermediate and higher trophic levels in reclaimed wetlands.

  16. Instrumental variable estimation of treatment effects for duration outcomes

    NARCIS (Netherlands)

    G.E. Bijwaard (Govert)

    2007-01-01

    textabstractIn this article we propose and implement an instrumental variable estimation procedure to obtain treatment effects on duration outcomes. The method can handle the typical complications that arise with duration data of time-varying treatment and censoring. The treatment effect we

  17. Effects of aging on blood pressure variability in resting conditions

    NARCIS (Netherlands)

    Veerman, D. P.; Imholz, B. P.; Wieling, W.; Karemaker, J. M.; van Montfrans, G. A.

    1994-01-01

    The objective of this study was to determine the effect of aging on beat-to-beat blood pressure and pulse interval variability in resting conditions and to determine the effect of aging on the sympathetic and vagal influence on the cardiovascular system by power spectral analysis of blood pressure

  18. Determinants of wood dust exposure in the Danish furniture industry.

    Science.gov (United States)

    Mikkelsen, Anders B; Schlunssen, Vivi; Sigsgaard, Torben; Schaumburg, Inger

    2002-11-01

    This paper investigates the relation between wood dust exposure in the furniture industry and occupational hygiene variables. During the winter 1997-98 54 factories were visited and 2362 personal, passive inhalable dust samples were obtained; the geometric mean was 0.95 mg/m(3) and the geometric standard deviation was 2.08. In a first measuring round 1685 dust concentrations were obtained. For some of the workers repeated measurements were carried out 1 (351) and 2 weeks (326) after the first measurement. Hygiene variables like job, exhaust ventilation, cleaning procedures, etc., were documented. A multivariate analysis based on mixed effects models was used with hygiene variables being fixed effects and worker, machine, department and factory being random effects. A modified stepwise strategy of model making was adopted taking into account the hierarchically structured variables and making possible the exclusion of non-influential random as well as fixed effects. For woodworking, the following determinants of exposure increase the dust concentration: manual and automatic sanding and use of compressed air with fully automatic and semi-automatic machines and for cleaning of work pieces. Decreased dust exposure resulted from the use of compressed air with manual machines, working at fully automatic or semi-automatic machines, functioning exhaust ventilation, work on the night shift, daily cleaning of rooms, cleaning of work pieces with a brush, vacuum cleaning of machines, supplementary fresh air intake and safety representative elected within the last 2 yr. For handling and assembling, increased exposure results from work at automatic machines and presence of wood dust on the workpieces. Work on the evening shift, supplementary fresh air intake, work in a chair factory and special cleaning staff produced decreased exposure to wood dust. The implications of the results for the prevention of wood dust exposure are discussed.

  19. Physicochemical patterns of ozone absorption by wood

    Science.gov (United States)

    Mamleeva, N. A.; Lunin, V. V.

    2016-11-01

    Results from studying aspen and pine wood ozonation are presented. The effect the concentration of ozone, the reagent residence time, and the content of water in a sample of wood has on ozone consumption rate and ozone demand are analyzed. The residence time is shown to determine the degree of ozone conversion degree and the depth of substrate destruction. The main patterns of ozone absorption by wood with different moisture content are found. Ways of optimizing the ozonation of plant biomass are outlined.

  20. Violates stem wood burning sustainable development?

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    2008-01-01

    friendly effects of substituting wood burning for fossil fuels. With reference to Bent Sørensen's classical work on 'Renewable Energy' the assumption of CO2-neutrality regarding incineration is problematised when applied to plants with long rotation periods as trees. Registered CO2-emissions from wood...... burning are characterised together with particle and PAH emissions. The positive treatment of wood stove-technology in the Danish strategy for sustainable development (draft 2007) is critically evaluated and approaches to better regulation are identified....

  1. EVALUATION OF STRENGTH TO SHEAR AND DELAMINATION IN GLUED LAMINATED WOOD

    Directory of Open Access Journals (Sweden)

    Carlito Calil Neto

    2014-12-01

    Full Text Available The Glued Laminated Wood has a large range of applications. In Brazil, its employment as cross-piece poles for overhead electrical power has attracted the attention of companies in the industry, motivated by the potential use of this material. Among the factors that influence the mechanical performance of Glulam solutions stand out efficiency and affinity of the adhesives to the species of wood used, the type of treatment and moisture content of wood veneer, motivating the development of new research on this topic. This research aimed to investigate, by Design of Experiments (DOE, the influence of wood (pinus, teca, eucalipto, adhesive (Purbond; Cascophen and treatment (CCA, CCB, CCBS in the variable responses shear strength and delamination, consisting in the same combination factors evaluated in ANEEL/EESC-PD220-07 project: Head Crosshead Glulam Series. The results of the statistical analysis showed that the species factor expressed significant effect for both response variables evaluated, did not occur with adhesive and treatment factors. Moisture content was significant in the wood evaluated when analyzed the shear strength, and the teca wood showed the highest shear strength and also relating to the delamination.

  2. Radiographic testing of wood

    International Nuclear Information System (INIS)

    Osterloh, K.; Zscherpel, U.; Raedel, C.; Weidemann, G.; Meinel, D.; Goebbels, J.; Ewert, U.; Hasenstab, A.; Buecherl, T.

    2007-01-01

    Wood is an old and established consumption and construction material. It is still the most common material for constructing furniture, roofs, playgrounds and mine supports. In contrast to steel and concrete, wood warns of extreme loads by creaking. Its mechanical stability is more influenced by decay than by peripheral cracks. While external cracks are visible, internal decay by fungus growth is undetectable from outside. This may be a safety problem in supporting structures. The best analysis of the internal structure is provided by computed tomography, but this is also the most complex method, much more so than simple radiographic testing. However, the latter is made inaccurate by scattered radiation resulting from internal moisture. With the image processing options of digital radiographic techniques, the structural information can be separated effectively from noise. In contrast to X-ray and gamma radiography, neutron radiography provides information on the spatial distribution of moisture. In healthy wood, water is conducted in the sapwood while the hardwood is dry. Moisture in hardwood is caused by infestations, e.g. fungus growth. The contribution presents a comparative analysis of the available radiographic methods. (orig.)

  3. Discover the benefits of residential wood heating

    International Nuclear Information System (INIS)

    2003-01-01

    This publication described how residential wood-heating systems are being used to reduce energy costs and increase home comfort. Biomass energy refers to all forms are renewable energy that is derived from plant materials. The source of fuel may include sawmills, woodworking shops, forest operations and farms. The combustion of biomass is also considered to be carbon dioxide neutral, and is not considered to be a major producer of greenhouse gases (GHG) linked to global climate change. Wood burning does, however, release air pollutants, particularly if they are incompletely burned. Incomplete combustion of wood results in dense smoke consisting of toxic gases. Natural Resources Canada helped create new safety standards and the development of the Wood Energy Technical Training Program to ensure that all types of wood-burning appliances are installed correctly and safely to reduce the risk of fire and for effective wood heating. In Canada, more than 3 million families heat with wood as a primary or secondary heating source in homes and cottages. Wood heating offers security from energy price fluctuations and electrical power failures. This paper described the benefits of fireplace inserts that can transform old fireplaces into modern heating systems. It also demonstrated how an add-on wood furnace can be installed next to oil furnaces to convert an oil-only heating system to a wood-oil combination system, thereby saving thousands of dollars in heating costs. Wood pellet stoves are another wood burning option. The fuel for the stoves is produced from dried, finely ground wood waste that is compressed into hard pellets that are loaded into a hopper. The stove can run automatically for up to 24 hours. New high-efficiency advanced fireplaces also offer an alternative heating system that can reduce heating costs while preserving Canada's limited supply of fossil fuels such as oil and gas. 13 figs

  4. Styrene-Assisted Maleic Anhydride Grafted Poly(lactic acid as an Effective Compatibilizer for Wood Flour/Poly(lactic acid Bio-Composites

    Directory of Open Access Journals (Sweden)

    Jun Du

    2017-11-01

    Full Text Available This study aimed to evaluate the effect of styrene-assisted maleic anhydride-grafted poly(lactic acid (PLA-g-St/MAH on the interfacial properties of wood flour/poly(lactic acid (PLA bio-composites. PLA-g-St/MAH was synthesized by free-radical melt grafting using styrene as a comonomer and dicumyl peroxide as an initiator. The structure of PLA-g-St/MAH was characterized by Fourier transform infrared spectroscopy. Wood flour/PLA composites were prepared by compression molding using PLA-g-St/MAH as a compatibilizer. The effects of PLA-g-St/MAH on the rheological and mechanical properties, as well as on the fractured surface morphology of the composites were investigated. Results indicated that storage modulus, complex viscosity, equilibrium torque, and shear heat were significantly increased. The mechanical properties of the wood flour/PLA composites were also significantly increased after the addition of PLA-g-St/MAH. The maximum values were achieved at the loading rate of 3 wt % because of the improved interfacial adhesion between the wood flour and the PLA matrix.

  5. Effect of lime and wood ash on the nixtamalization of maize and tortilla chemical and nutritional characteristics.

    Science.gov (United States)

    Pappa, María Renée; de Palomo, Patricia Palacios; Bressani, Ricardo

    2010-06-01

    The objective of the study was to obtain information on the chemical composition, functional properties, sensory quality and protein value of tortillas made from the nixtamalization of maize using either lime or wood ashes. The Ca, K, Mg, Fe, and Zn content of lime and wood ashes showed lime to be high in Ca content while wood ash contained more K and about 71% of the Ca content of lime. Both contained relatively high levels of Mg, Fe and Zn, but more so in the wood ashes. The level of reagent for nixtamalization was set at 0.8% of the maize weight. All other processing conditions were kept constant. The pH of the cooking solution was 12.0 for lime and 10.9 for wood ash. The moisture content of maize at 60 min of cooking was 45.8% for both treatments, however after 12 h of soaking, moisture level was 51.0% for the lime treatment and only 46.8% for the ash treatment. Solids (2.4%) in the lime cooking liquor were higher than in the wood ash liquor (1.0%). Chemical composition changes were similar between treatments in masa and tortilla; however, both masa and tortillas absorbed relatively high levels of all minerals including Fe and Zn from the wood ash treatment. The different treatment influenced functional properties particularly hardness and color. Tortilla characteristics were also similar. Protein quality of both alkali cooked products was lower than that of raw corn, more so the product from the wood ash treatment. Although some differences were observed in the sensory studies, human subjects did not dislike the wood ash made tortillas.

  6. DNA Damage among Wood Workers Assessed with the Comet Assay

    Science.gov (United States)

    Bruschweiler, Evin Danisman; Wild, Pascal; Huynh, Cong Khanh; Savova-Bianchi, Dessislava; Danuser, Brigitta; Hopf, Nancy B.

    2016-01-01

    Exposure to wood dust, a human carcinogen, is common in wood-related industries, and millions of workers are occupationally exposed to wood dust worldwide. The comet assay is a rapid, simple, and sensitive method for determining DNA damage. The objective of this study was to investigate the DNA damage associated with occupational exposure to wood dust using the comet assay (peripheral blood samples) among nonsmoking wood workers (n = 31, furniture and construction workers) and controls (n = 19). DNA damage was greater in the group exposed to composite wood products compared to the group exposed to natural woods and controls (P < 0.001). No difference in DNA damage was observed between workers exposed to natural woods and controls (P = 0.13). Duration of exposure and current dust concentrations had no effect on DNA damage. In future studies, workers’ exposures should include cumulative dust concentrations and exposures originating from the binders used in composite wood products. PMID:27398027

  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. Understanding the variable effect of instructional innovations on student learning

    Science.gov (United States)

    Iverson, Heidi L.

    2012-02-01

    As a result of dissatisfaction with the traditional lecture-based model of education a large number of reform-oriented instructional innovations have been developed, enacted, and studied in undergraduate physics courses. While previous work has shown that the impact of instructional innovations on student learning has been overwhelmingly positive, it has also been highly variable. The purpose of this analysis is to investigate this variability. For this analysis, 79 published studies on undergraduate physics instructional innovations were analyzed with respect to the types of innovations used and the methodological characteristics of the studies themselves. The findings of this analysis have indicated that nearly half of the variability in effect size can be accounted for by study design characteristics rather than by the characteristics of the innovations used. However, a subsequent analysis illustrated that one specific innovation, Workshop/Studio Physics, appears to be particularly effective within the observed sample of studies.

  9. EFFECTS OF CORPORATE GOVERNANCE VARIABLES ON EARNINGS MANAGEMENT IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Stephanus Remond Waworuntu

    2017-03-01

    Full Text Available To determine the effects of corporate governance on earnings management, this paper analyzed 171 annualreports from issued 2006 to 2009 by 57 non-financial, joint stock companies implementing GCG (GoodCorporate Governance practices, which were listed on the Indonesia Stock Exchange (IDX. Six corporategovernance variables (board composition, independent commissioners, separate chairman/CEO roles, auditcommittee, managerial share ownership, and audit quality as well as three control variables (leverage, size,and ROA were used. The results showed that two corporate governance variables significantly influencedearnings management practices (separate chairman/CEO roles and managerial share ownership; the othervariables had no effect because these companies used GCG practices only to follow regulations rather than tomonitor and control.

  10. 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.

  11. 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.

  12. DIVERSITY AND ECOLOGICAL DETERMINANTS OF DEAD WOOD FUNGI IN TREE NATURAL RESERVES OF BROAD LEAVED FORESTS FROM SUCEAVA COUNTY

    Directory of Open Access Journals (Sweden)

    Ciprian BÎRSAN

    2014-12-01

    Full Text Available Dead wood fungi have a major importance for forests biodiversity as they produce wood degradation in forest habitats. In this paper are presented some aspects related to the diversity of dead wood fungi in tree deciduous forest types from tree natural reserves (Crujana, Dragomirna and Zamostea from Suceava County and the effect of some ecological factors (host tree, diameter and decomposition degree of the dead wood and some microclimatic characteristics of sites on their occurrence and diversity. Investigations carried out in 2013 resulted in the identification of 44 lignicolous fungi species. Analysis of similarities between lingnicolous fungi species from the investigated natural reserves (by hierarchical clustering shows a separation of three fungi groups, depending on the host-trees species. The effect of the tree host species was highlighted also by detrended correspondence analysis, which, in addition presented the existence of an altitudinal gradient and a weaker effect of site conditions (slope and aspect and microclimatic variables (solar radiation on dead wood fungi occurrence. The effect of diameter and decomposition degree of fallen trunks and branches on dead wood fungi species was investigated using the redundancy analysis showing that wood debris with large surfaces are more easily colonized by the fungi species developing large sporocarps compared to small branches with low diameters colonized only by few or a single fungus species.

  13. Effect of Thermal Storage on the Performance of a Wood Pellet-fired Residential Boiler

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Butcher [Brookhaven National Laboratory (BNL), Upton, NY (United States). Sustainable Energy Technologies Dept.

    2017-08-31

    Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood pellet-fired residential boilers, which are the cleanest fuel in this category. In the residential application the load varies strongly over the course of a year and a high fraction of the load is typically under 15% of the maximum boiler capacity. Thermal storage can be used even with boilers which have modulation capacity typically to 30% of the boiler maximum. One common pellet boiler was tested at full load and also at the minimum load used in the U.S. certification testing (15%). In these tests the load was steady over the test period. Testing was also done with an emulated load profile for a home in Albany, N.Y. on a typical January, March, and April day. In this case the load imposed on the boiler varied hourly under computer control, based on the modeled load for the example case used. The boiler used has a nominal output of 25 kW and a common mixed hardwood/softwood commercial pellet was used. Moisture content was 3.77%. A dilution tunnel approach was used for the measurement of particulate emissions, in accordance with U.S. certification testing requirements. The test results showed that the use of storage strongly reduces cycling rates under part load conditions. The transients which occur as these boilers cycle contribute to increased particulate emissions and reduced efficiency. The time period of a full cycle at a given load condition can be increased by increasing the storage tank volume and/or increasing the control differential range. It was shown that increasing the period strongly increased the measured efficiency and reduced the particulate emission (relative to the no storage case). The impact was most significant at the low load levels. Storage tank heat loss is shown to be a significant factor in thermal efficiency

  14. Effect of wood waste on the digestibility of carbohydrates and the level of volatile fatty acids in sheep

    Energy Technology Data Exchange (ETDEWEB)

    Zelanak, I; Cerny, I; Apalovic, R; Doskova, E

    1977-01-01

    In sheep, the use of steam-treated beech sawdust and thickened aqueous hydrolyzate of beech wood (xylocel) as a replacer for ground barley straw favorably influenced the digestibility of monosaccharides, cellulose, lignin, and total dry matter of the diet. Sawdust reduced the concentration of total volatile fatty acids (VFA) in the rumen content, but the ratio of HOAc to EtCO/sub 2/H (A:P) was lower and the energetic efficiency of the VFA produced was higher in the diet containing sawdust. The addition of urea to the diet with beech sawdust conditioned less effectively, and did not give a clear effect. Urea increased the digestibility of pentosans, glucose, and cellulose, but reduced the energetic efficiency of the VFA produced. Xylocel had no clear effect on the digestibility of sugars, either. The higher A:P ratio and the lower energetic efficiency of the VFA produced testify to the fact that xylocel in combination with beet molasses was not a sufficient replacer of sugar beet carbohydrates.

  15. 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...

  16. Theoretical and experimental studies on emissions from wood combustion

    Energy Technology Data Exchange (ETDEWEB)

    Skreiberg, Oeyvind

    1997-12-31

    This thesis discusses experiments on emissions from wood log combustion and single wood particle combustion, both caused by incomplete combustion and emissions of nitric and nitrous oxide, together with empirical and kinetic NO{sub x} modelling. Experiments were performed in three different wood stoves: a traditional stove, a staged air stove and a stove equipped with a catalytic afterburner. Ideally, biomass fuel does not give a net contribution to the greenhouse effect. However, incomplete combustion was found to result in significant greenhouse gas emissions. Empirical modelling showed the excess air ratio and the combustion chamber temperature to be the most important input variables controlling the total fuel-N to NO{sub x} conversion factor. As the result of an international round robin test of a wood stove equipped with a catalytic afterburner, particle emission measurements were found to be the best method to evaluate the environmental acceptability of the tested stove, since the particle emission level was least dependent of the national standards, test procedures and calculation procedures used. In batch single wood particle combustion experiments on an electrically heated small-scale fixed bed reactor the fuel-N to NO conversion factor varied between 0.11-0.86 depending on wood species and operating conditions. A parameter study and homogeneous kinetic modelling on a plug flow reactor showed that, depending on the combustion compliance in question, there is an optimum combination of primary excess air ratio, temperature and residence time that gives a maximum conversion of fuel-N to N{sub 2}. 70 refs., 100 figs., 26 tabs.

  17. Unpalatable plants facilitate tree sapling survival in wooded pastures

    NARCIS (Netherlands)

    Smit, C.; Ouden, den J.; Müller-Schärer, H.

    2006-01-01

    Summary 1. In endangered wooded pasture ecosystems established tree saplings are frequently found in spatial association with protective structures, suggesting nurse effects. This associational resistance is thought to be a driving force behind tree regeneration in wooded pastures. Experimental

  18. Variable viscosity effects on mixed convection heat and mass ...

    African Journals Online (AJOL)

    DR OKE

    the effects of viscous dissipation and variable viscosity on the flow of heat and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate in the ..... been solved by Gauss-. Seidel iteration method and numerical values are carried out after executing the computer program for it. In order to prove.

  19. Variable viscosity effects on mixed convection heat and mass ...

    African Journals Online (AJOL)

    An analysis is carried out to study the viscous dissipation and variable viscosity effects on the flow, heat and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate in the presence of chemical reaction. The governing boundary layer equations are written into a dimensionless form by similarity ...

  20. Effects of Liraglutide on Heart Rate and Heart Rate Variability

    DEFF Research Database (Denmark)

    Kumarathurai, Preman; Anholm, Christian; Larsen, Bjørn Strøier

    2017-01-01

    OBJECTIVE: Reduced heart rate variability (HRV) and increased heart rate (HR) have been associated with cardiovascular mortality. Glucagon-like peptide 1 receptor agonists (GLP-1 RAs) increase HR, and studies have suggested that they may reduce HRV. We examined the effect of the GLP-1 RA...

  1. The survey of accounting variables effect on incomesmoothing in ...

    African Journals Online (AJOL)

    In the present study the effects of company size, income-ability, institutional proprietorship, financial leverage and income rate have been surveyed as accounting variables on the income smoothing of the companies accepted in Tehran's securities market. The study has investigated 146 companies accepted in Tehran's ...

  2. Effect of Climate Variability on Crop Income in Central Ethiopia

    Directory of Open Access Journals (Sweden)

    Arega Shumetie Ademe

    2017-12-01

    Full Text Available Ethiopian agriculture is a vulnerable sector from effects of climate variability. This study identified how strong is the effect of climate variability on smallholders’ crop income in Central highlands and Arssi grain plough farming systems of the country. The unbalanced panel data (1994-2014 of the study collected for eight rounds analysed through fixed effect regression. The model result shows that successive increment of crop season rainfall keeping the temperature constant has negative and significant effect on households’ crop income in the study area. The crop income responds similarly for temperature increment if the rainfall remains constant. Given this, simultaneous increment of the two climate related inputs has positive and significant effect on crop income. Other variables like flood, frost, storm, and rainfall inconsistency in the onset and cessation time affected households’ crop income negatively and significantly. Similarly, draught power and human labour, which are critical inputs in the crop production of Ethiopian smallholders, have positive and significant effect on crop income as to the model result. Thus, this study recommended that there should be supplementing the rainfall through irrigation, check dam and other activities to have consistent water supply for the crop production that enable smallholders to collect better income. Additionally, negative effect of temperature increment should be curved through adopting long lasting strategies like afforestation.

  3. 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.

  4. 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)

  5. 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 ...

  6. 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 ( ...

  7. 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 ...

  8. 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 ...

  9. Reducing the moisture effect on the creep deformation of wood by an irradiation-induced polymer impregnation method

    International Nuclear Information System (INIS)

    Chia, L.H.L.; Boey, F.Y.C.; Teoh, S.H.

    1988-01-01

    This paper reports an attempt to reduce the sensitivity of creep deformation to moisture adsorption by impregnating a tropical wood with methyl-methacrylate and subsequent polymerization by γ-irradiation. Beam specimens both of untreated wood and polymer impregnated wood were subjected to a three-point bend creep test under a constant load of 300 N at 23 ± 1 0 C, at three different humidity levels of 50 ± 5, 65 ± 5 and 85 ± 5%. A Norton-Bailey (power law) mathematical model successfully described the creep behaviour, with the creep components determined by a non-linear regression analysis. A significant reduction in the sensitivity of creep deformation to the humidity level was attained for the polymer impregnated wood. This could be explained by the ability of the impregnated polymer to form a strongly adhesive interface with the wood cell material, thereby acting as a physical barrier to reduce the movement of water to and from the wood cell material. (author)

  10. Variable scaling method and Stark effect in hydrogen atom

    International Nuclear Information System (INIS)

    Choudhury, R.K.R.; Ghosh, B.

    1983-09-01

    By relating the Stark effect problem in hydrogen-like atoms to that of the spherical anharmonic oscillator we have found simple formulas for energy eigenvalues for the Stark effect. Matrix elements have been calculated using 0(2,1) algebra technique after Armstrong and then the variable scaling method has been used to find optimal solutions. Our numerical results are compared with those of Hioe and Yoo and also with the results obtained by Lanczos. (author)

  11. 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....

  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. EFFECT OF IMMERSION TEMPERATURE ON THE WATER UPTAKE OF POLYPROPYLENE/WOOD FLOUR/ORGANOCLAY HYBRID NANOCOMPOSITE

    Directory of Open Access Journals (Sweden)

    Behzad Kord

    2011-02-01

    Full Text Available Polypropylene/wood flour/organoclay hybrid nanocomposites were melt-compounded in an internal mixer at 190 oC and 60 rpm rotor speed. Then samples were fabricated by injection molding. Effects of immersion temperature on the water uptake of hybrid nanocomposite were investigated. To meet this objective, water absorption of samples was determined after 24 h immersion in distilled water at different temperatures (25, 50, 75, and 100 °C. Results indicated that immersion temperature had a significant influence on the water absorption of composites. By increasing the temperature, water absorption increases as well. The maximum water absorption of composite is decreased by increasing the nanoclay and compatibilizer content. The morphology of nanoclay was determined by X-ray diffraction (XRD and transmission electron microscopy. The effect of morphology on water absorption was also evaluated. Due to inadequate compatibilizer, exfoliated morphology of nanoclay was not obtained, but there was evidence of intercalation. The order of intercalation for samples containing 3 phc was higher than that of 6 phc at the same PP-g-MA content due to some agglomerations of organoclay.

  14. Probing the effect of polymer molecular weight on penetration into the wood cell wall using polyethylenimine (PEI) as a model compound.

    Science.gov (United States)

    Dorvel, Brian; Boopalachandran, Praveenkumar; Chen, Ida; Bowling, Andrew; Williams, Kerry; King, Steve

    2018-05-01

    Decking is one of the largest applications for the treated wood market. The most challenging property to obtain for treated wood is dimensional stability, which can be achieved, in part, by cell wall bulking, cell wall polymer crosslinking and removal of hygroscopic components in the cell wall. A commonly accepted key requirement is for the actives to infuse through the cell wall, which has a microporosity of ∼5-13 nm. Equally as challenging is being able to measure and quantify the cell wall penetration. Branched polyethylenimine (PEI) was studied as a model polymer for penetration due to its water solubility, polarity, variable molecular weight ranges, and ability to form a chelation complex with preservative metals to treat lumbers. Two different molecular weight polyethylenimines (PEI), one with a weight average molecular weight (Mw) equal to 800 Da and the other 750 000 Da, were investigated for penetration by microscopy and spectroscopy techniques. Analytical methods were developed to both create smooth interfaces and for relative quantitation and visualisation of PEI penetration into the wood. The results showed both PEI with Mw of 800 Da and PEI with Mw of 750 000 Da coated the lumens in high density. However, only the PEI with Mw of 800 appeared to penetrate the cell walls in sufficient levels. Literature has shown the hydrodynamic radii of PEI 750 000 is near 29 nm, whereas a smaller PEI at 25 K showed 4.5 nm. Most importantly the results, based on methods developed, show how molecular weight and tertiary structure of the polymer can affect its penetration, with the microporosity of the wood being the main barrier. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  15. Wood-energy - The sector get worried

    International Nuclear Information System (INIS)

    Mary, Olivier; Signoret, Stephane; Bohlinger, Philippe; Guilhem, Jean; De Santis, Audrey; Sredojevic, Alexandre; Defaye, Serge; Maindrault, Marc

    2017-01-01

    Wood energy is, today and certainly also tomorrow, one of the most important renewable energies in France. However, the wood-energy sector seems to slow down as hydrocarbon prices stay extremely low. This document presents 8 articles, describing the context and the characteristics of this evolution, plus some examples of developments in France. The themes of the articles are: the activity of the wood-energy sector should be reinforced to meet the objectives of the French energy multi-year plan; The 2035 prospective of the wood yield in the French forest will meet the future demand, however this evaluation does not take into consideration the effects of the climatic change; the conversion to biomass of the 'Fort de l'Est' (near Paris) heating system (equipped with a boiling fluidized bed boiler) has enabled the heat network to beat the 50 pc share of renewable energy; wood-energy professionals use the 'quality' lever to challenge their fossil fuel competitors; the city of Orleans is now equipped with an innovative biomass cogeneration plant; the example of wood waste valorization in a French sawmill; the French ONF (Forest Administration) Wood-Energy actor has just inaugurated its largest biomass dryer, in order to develop the domestic market for wood as a fuel; analysis of the technical and economical feasibility of using wood to generate electric power or replacing electric space heating by heat network

  16. Effect of atrioventricular conduction on heart rate variability

    KAUST Repository

    Ahmad, Talha Jamal

    2011-08-01

    This paper discusses the effect of atrioventricular conduction time (AVCT) on the short-term Heart Rate Variability (HRV) by computing HRV parameters using intervals between the onsets of successive P waves (PP time series) for three groups: normal, arrhythmia and sudden cardiac death (SCD) patients. A very precise wavelet transform based ECG delineator was developed to detect PP, PR and RR time series. Mean PR variation in arrhythmia and SCD group was found to be significantly high as compared to the normal group. It was observed that when PR variations in arrhythmia and SCD cases crossed a certain threshold, RR variability no longer provided a very accurate estimate of HRV. In such cases, PP variability was able to provide a better assessment of HRV. © 2011 IEEE.

  17. Effective Analysis of C Programs by Rewriting Variability

    DEFF Research Database (Denmark)

    Iosif-Lazar, Alexandru Florin; Melo, Jean; Dimovski, Aleksandar

    2017-01-01

    and effective analysis and verification of real-world C program families. Importance. We report some interesting variability-related bugs that we discovered using various state-of-the-art single-program C verification tools, such as Frama-C, Clang, LLBMC.......Context. Variability-intensive programs (program families) appear in many application areas and for many reasons today. Different family members, called variants, are derived by switching statically configurable options (features) on and off, while reuse of the common code is maximized. Inquiry....... Verification of program families is challenging since the number of variants is exponential in the number of features. Existing single-program analysis and verification tools cannot be applied directly to program families, and designing and implementing the corresponding variability-aware versions is tedious...

  18. 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....

  19. 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

  20. 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...

  1. 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...

  2. 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....

  3. 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

  4. Simulated nitrogen deposition affects wood decomposition by cord-forming fungi.

    Science.gov (United States)

    Bebber, Daniel P; Watkinson, Sarah C; Boddy, Lynne; Darrah, Peter R

    2011-12-01

    Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carbon cycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at Wytham Wood, Oxfordshire, UK. Mass loss was greater with P. velutina than with H. fasciculare, and with N treatment than in the control. Decomposition was accompanied by growth of the fungal mycelium and increasing N concentration in the remaining wood. We attribute the N effect on wood decay to the response of cord-forming wood decay fungi to N availability. Previous studies demonstrated the capacity of these fungi to scavenge and import N to decaying wood via a translocating network of mycelium. This study shows that small increases in N availability can increase wood decomposition by these organisms. Dead wood is an important carbon store and habitat. The responses of wood decomposers to anthropogenic N deposition should be considered in models of forest carbon dynamics.

  5. Wood pole overhead lines

    CERN Document Server

    Wareing, Brian

    2005-01-01

    This new book concentrates on the mechanical aspects of distribution wood pole lines, including live line working, environmental influences, climate change and international standards. Other topics include statutory requirements, safety, profiling, traditional and probabilistic design, weather loads, bare and covered conductors, different types of overhead systems, conductor choice, construction and maintenance. A section has also been devoted to the topic of lightning, which is one of the major sources of faults on overhead lines. The book focuses on the effects of this problem and the strate

  6. 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.

  7. Dissolution of granulated wood ash examined by in situ incubation: Effects of tree species and soil type

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Ingerslev, M.; Raulund-Rasmussen, K.

    2007-01-01

    handling and to avoid undesired effects on vegetation and leaching of nutrients. Forest ecosystems with different tree species and soils provide variable conditions for mineral dissolution with respect to pH, amount of organic ligands and humidity in the forest floor and the top soil. To study the effects...

  8. 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.

  9. Effect of micro-oxygenation and wood type on the phenolic composition and color of an aged red wine.

    Science.gov (United States)

    Sánchez-Iglesias, Montserrat; González-Sanjosé, Ma Luisa; Pérez-Magariño, Silvia; Ortega-Heras, Miriam; González-Huerta, Carlos

    2009-12-23

    Many studies have recently been published focused on the effects of micro-oxygenation on the quality of wines, its application modes, and doses, etc. However, there are still few scientific papers on how previously micro-oxygenated wines perform during storage or barrel aging. This study focused on the evolution of the phenolic composition, especially of anthocyanins, and color, together with astringency and tannins, during micro-oxygenation before barrel aging. In addition, to evaluate whether wine evolution during aging depends on barrel type, wines were aged in four different oak barrel types. Tempranillo wines, some micro-oxygenated before malolactic fermentation and others not, were aged for 12 months in American, French, Central European, and Spanish oak, following wine evolution during that period. The study was carried out for two consecutive vintages. Results showed that all wines evolved similarly; therefore, the micro-oxygenation treatment neither accelerated nor delayed the typical changes of aging. Slightly different evolutions were detected according to the barrel wood type, whether or not the wine was micro-oxygenated. The varied evolutions must therefore be associated with the differences from each oak type (structure, grain and density, composition, etc.).

  10. 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.

  11. Wood-ash addition on a drained forest peatland in Southern Sweden - Effects on water chemistry; Tillfoersel av biobra ensleaska i tallskog paa en dikad torvmark i soedra Sverige - Effekter paa vattenkemin

    Energy Technology Data Exchange (ETDEWEB)

    Ring, Eva; Broemssen, Claudia von; Losjoe, Katarina; Sikstroem Ulf

    2012-02-15

    Wood ash can be used for forest fertilization on peatlands or for nutrient compensation following intensive harvesting. This project was performed in order to investigate effects on water chemistry of applying wood ash to a Scots pine stand on a drained peatland. Ditch-water chemistry was monitored before and after the application of wood ash. Furthermore, groundwater was collected and chemically analyzed both from the ash-treated peatland and from an adjacent untreated reference peatland. Both short term (a few months) and more long term effects (up to three years after application) were detected on water chemistry

  12. The effect of economic variables over a biodiesel production plant

    Energy Technology Data Exchange (ETDEWEB)

    Marchetti, J.M., E-mail: jmarchetti@plapiqui.edu.ar [Planta Piloto de Ingenieria Quimica (UNS-CONICET), Camino La Carrindanga km 7, 8000 Bahia Blanca (Argentina)

    2011-09-15

    Highlights: {yields} Influence of the mayor economic parameters for biodiesel production. {yields} Variations of profitability of a biodiesel plant due to changes in the market scenarios. {yields} Comparison of economic indicators of a biodiesel production facility when market variables are modified. - Abstract: Biodiesel appears as one of the possible alternative renewable fuels to substitute diesel fuel derived from petroleum. Several researches have been done on the technical aspects of biodiesel production in an attempt to develop a better and cleaner alternative to the conventional process. Economic studies have been carried out to have a better understanding of the high costs and benefits of different technologies in the biodiesel industry. In this work it is studied the effect of the most important economic variables of a biodiesel production process over the general economy of a conventional plant which employs sodium methoxide as catalyst. It has been analyzed the effect of the oil price, the amount of free fatty acid, the biodiesel price, the cost of the glycerin, the effect due to the modification on the methanol price, the washing water price, and several others. Small variations on some of the major market variables would produce significant effects over the global economy of the plant, making it non profitable in some cases.

  13. The effect of economic variables over a biodiesel production plant

    International Nuclear Information System (INIS)

    Marchetti, J.M.

    2011-01-01

    Highlights: → Influence of the mayor economic parameters for biodiesel production. → Variations of profitability of a biodiesel plant due to changes in the market scenarios. → Comparison of economic indicators of a biodiesel production facility when market variables are modified. - Abstract: Biodiesel appears as one of the possible alternative renewable fuels to substitute diesel fuel derived from petroleum. Several researches have been done on the technical aspects of biodiesel production in an attempt to develop a better and cleaner alternative to the conventional process. Economic studies have been carried out to have a better understanding of the high costs and benefits of different technologies in the biodiesel industry. In this work it is studied the effect of the most important economic variables of a biodiesel production process over the general economy of a conventional plant which employs sodium methoxide as catalyst. It has been analyzed the effect of the oil price, the amount of free fatty acid, the biodiesel price, the cost of the glycerin, the effect due to the modification on the methanol price, the washing water price, and several others. Small variations on some of the major market variables would produce significant effects over the global economy of the plant, making it non profitable in some cases.

  14. Environmental determinants of the old oaks in wood-pastures from a changing traditional social-ecological system of Romania.

    Science.gov (United States)

    Moga, Cosmin Ioan; Samoilă, Ciprian; Öllerer, Kinga; Băncilă, Raluca I; Réti, Kinga-Olga; Craioveanu, Cristina; Poszet, Szilárd; Rákosy, László; Hartel, Tibor

    2016-05-01

    Large, old trees are keystone ecological structures, their decline having disproportional ecological consequences. There is virtually no information available regarding the status and occurrence of old trees in traditional cultural landscapes from Eastern Europe. In this study, we explore the environmental determinants of the old oaks found in wood-pastures from a changing traditional rural landscape from Central Romania. Both the old oaks and the wood-pastures harboring them have exceptional cultural, historical, and ecological values, yet are vulnerable to land-use change. We surveyed 41 wood-pastures from Southern Transylvania and counted the old oaks in them. We then related the number of old oaks from these wood-pastures to a set of local and landscape level variables related to wood-pastures. We found 490 old oaks in 25 wood-pastures. The number of old oaks was positively related to the size of the wood-pasture and the amount of pasture and forest around it (500 m buffer), and negatively related to the proximity of the village. Furthermore, we found a significant interaction between the effects of sheepfolds in the wood-pasture and the size of the wood-pasture on the number of old trees, indicating a negative influence of sheepfolds on the number of old trees in smaller sized wood-pastures. There is an increasing risk for losing old trees in the traditional cultural landscapes due to the lack of formal recognition of these trees. Therefore, while presenting the positive example of local initiatives and citizen science, we argue for an urgent development and implementation of conservation policies along with education strategies targeting the old trees and rural communities from the changing traditional cultural landscapes of Eastern Europe.

  15. A Study of the Kepler K2 Variable EPIC 211957146 Exhibiting a Variable O’ Connell Effect

    Energy Technology Data Exchange (ETDEWEB)

    Sriram, K.; Malu, S.; Rao, P. Vivekananda [Department of Astronomy, Osmania University, Hyderabad 500007 (India); Choi, C. S., E-mail: astrosriram@yahoo.co.in [Korea Astronomy and Space Science Institute, Daejeon 34055 (Korea, Republic of)

    2017-05-01

    We present the multi-band photometric and spectroscopic study of an over-contact binary system, EPIC 211957146. The light curves exhibit a variable O’ Connell effect, confirmed from our observational data and the Kepler K2 data. The best photometric solution incorporating a dark spot over the primary component unveils that the system has a low-mass ratio ( q  ∼ 0.17) and a high inclination ( i  ∼ 85°). To confirm the solution and constrain the uncertainty, Monte-Carlo simulations are performed and the results are reported. Based on the O–C diagram analysis, we see that the variable shows a period increase at the rate of dP / dt  ∼ 1.06 × 10{sup −6} days yr{sup −1}, which is higher than the theoretically predicted value. Presence of a third body having a period of ∼16.23 years is evident from the O–C diagram. No filled-in effect is observed in the H α line, while the effect is vividly present in the Na line. From the Kepler K2 data, we found that the primary and secondary minima exhibit an anti-correlated O–C variation followed by an erratic behavior. This is possibly caused by the longitudinal motion of the spot, and hence, we set a lower limit of ∼40 days for the spot modulation. We also observe a possibly associated photometric difference in the primary depth by comparing our light curves with Kepler K2 normalized light curves. This system has a low-mass ratio and a high fill-out factor, and, theoretically, such a physical configuration would lead to a merger.

  16. A Study of the Kepler K2 Variable EPIC 211957146 Exhibiting a Variable O’ Connell Effect

    International Nuclear Information System (INIS)

    Sriram, K.; Malu, S.; Rao, P. Vivekananda; Choi, C. S.

    2017-01-01

    We present the multi-band photometric and spectroscopic study of an over-contact binary system, EPIC 211957146. The light curves exhibit a variable O’ Connell effect, confirmed from our observational data and the Kepler K2 data. The best photometric solution incorporating a dark spot over the primary component unveils that the system has a low-mass ratio ( q  ∼ 0.17) and a high inclination ( i  ∼ 85°). To confirm the solution and constrain the uncertainty, Monte-Carlo simulations are performed and the results are reported. Based on the O–C diagram analysis, we see that the variable shows a period increase at the rate of dP / dt  ∼ 1.06 × 10 −6 days yr −1 , which is higher than the theoretically predicted value. Presence of a third body having a period of ∼16.23 years is evident from the O–C diagram. No filled-in effect is observed in the H α line, while the effect is vividly present in the Na line. From the Kepler K2 data, we found that the primary and secondary minima exhibit an anti-correlated O–C variation followed by an erratic behavior. This is possibly caused by the longitudinal motion of the spot, and hence, we set a lower limit of ∼40 days for the spot modulation. We also observe a possibly associated photometric difference in the primary depth by comparing our light curves with Kepler K2 normalized light curves. This system has a low-mass ratio and a high fill-out factor, and, theoretically, such a physical configuration would lead to a merger.

  17. 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

  18. The effect of CaCl2 on growth rate, wood decay and oxalic acid accumulation in Serpula lacrymans and related brown-rot fungi

    Science.gov (United States)

    Anne Christine Steenkjaer Hastrup; Bo Jensen; Carol Clausen; Frederick Green

    2006-01-01

    The dry rot fungus, Serpula lacrymans, is one of the most destructive copper-tolerant fungi causing timber decay in buildings in temperate regions. Calcium and oxalic acid have been shown to play important roles in the mechanism of wood decay. The effect of calcium on growth and decay was evaluated for 12 strains of S. lacrymans and compared to five brown-rot fungi....

  19. 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.

  20. Ultrasound assisted extraction of natural dye from jackfruit's wood (Artocarpus heterophyllus): The effect of ethanol concentration as a solvent

    Science.gov (United States)

    Febriana, Ike Dayi; Gala, Selfina; Mahfud, Mahfud

    2017-05-01

    Azo dye are synthetic organic dyes which has an azo group (- N = N -) as chromophore. Azo dye is resistand to decomposition process and harmfull for the environment and human being. Natural dye can be used as substitution of azo dye at textile industry. Natural dye are eco - friendly and can be applied for dyeing of fibrous material. Natural dye can be obtained from natural origin such as leaves, wood, or roots. The wood of jackfruit (Artocarpus heterophyllus) can used as natural source of natural dye. Ultrasound assisted extraction (UAE) is a new method that can be used to extract natural dye from jackfruit's wood. The aim of this research are to study about influence of ethanol concentration as solvent and extraction kinetic. Jackfruit's wood dust from sawmill used for the experimentation were sifted by sieve 35 mesh. Ethanol 96% used as solvent of this experiment and varied the concentration in volume to volume ratio (v/v). Experiment were carried out from 20 to 50 minutes. The result of this experiment shows that ethanol concentration influenced yield of extraction from jackfruit's wood. Concentration of ethanol will be affected polarity of solvent. The Peleg model was used to describe about kinetic model of natural dye extraction. Value of k1 and k2 constant are 0.003835 and 0.04186 respectively.

  1. The effect of moisture content on the corrosion of fasteners embedded in wood subjected to alkaline copper quaternary treatment

    International Nuclear Information System (INIS)

    Zelinka, Samuel L.; Glass, Samuel V.; Derome, Dominique

    2014-01-01

    Highlights: • We examine the dependence of metal corrosion on wood moisture content. • Corrosion of steel and galvanized steel in treated wood were measured. • Corrosion products were analyzed across moisture contents using X-ray diffraction. • The corrosion rate has a sigmoidal dependence on moisture content. • The data herein can be used to improve combined hygrothermal–corrosion models. - Abstract: This paper characterizes the corrosion rate of embedded fasteners as a function of wood moisture content using gravimetric and electrochemical measurements. The results indicated that the corrosion rate increased with moisture content before reaching a plateau. The phases present in the corrosion products, as analyzed using X-ray diffraction, are generally consistent with previous work. Uniform corrosion was observed for all fasteners and all conditions except steel fasteners embedded in water-saturated wood. Data of dependence of corrosion rate on moisture content, presented herein, are necessary to ensure the accuracy of combined hygrothermal/corrosion models used to predict durability of wood structures

  2. Factors affecting distribution of wood, detritus, and sediment in headwater streams draining managed young-growth red alder - Conifer forests in southeast Alaska

    Science.gov (United States)

    Gomi, T.; Johnson, A.C.; Deal, R.L.; Hennon, P.E.; Orlikowska, E.H.; Wipfli, M.S.

    2006-01-01

    Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) - conifer riparian forests (40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder-conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width (0.5-3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels. ?? 2006 NRC.

  3. Evaluating disease management programme effectiveness: an introduction to instrumental variables.

    Science.gov (United States)

    Linden, Ariel; Adams, John L

    2006-04-01

    This paper introduces the concept of instrumental variables (IVs) as a means of providing an unbiased estimate of treatment effects in evaluating disease management (DM) programme effectiveness. Model development is described using zip codes as the IV. Three diabetes DM outcomes were evaluated: annual diabetes costs, emergency department (ED) visits and hospital days. Both ordinary least squares (OLS) and IV estimates showed a significant treatment effect for diabetes costs (P = 0.011) but neither model produced a significant treatment effect for ED visits. However, the IV estimate showed a significant treatment effect for hospital days (P = 0.006) whereas the OLS model did not. These results illustrate the utility of IV estimation when the OLS model is sensitive to the confounding effect of hidden bias.

  4. Granulated wood ash to forest soils. Effects on microorganisms, phosphorus availability, and spatial relationships in the humus layer

    International Nuclear Information System (INIS)

    Clarholm, Marianne

    1999-01-01

    The report summarises effects on microorganisms, phosphorus (P) availability and spatial relationships in the humus layer of two spruce forests in south-western Sweden four to seven years after application of 3.2 tonnes (t) (Skogaby), alternatively three or six t (Torup) of granulated wood ash. There were tendencies for increases in pH and in numbers of ciliates, flagellates and small nematodes while no effects were observed for naked amoebae, the major consumers of bacteria among the protozoa. After seven years, the amount of P in microbial biomass in the humus layer in the wood ash treatment (A) in Skogaby was significantly higher than in the control (C), increased amounts of microbial nitrogen and carbon were also recorded. Observations over time indicated that the P availability in the soil first decreased after the ash addition, but later increased above that in the control. The time course was most readily seen in the microbial biomass, which contained 50% of total P in the humus layer, an amount equal to ten times the yearly uptake in trees. The microbial biomass has a much higher P concentration as compared to the needles, the component of the tree with the highest concentration. The P in micro-organisms thus form a buffer against P deficiency for the trees. A test where the 32 P uptake rate of excised mycorrhizal fine roots in the laboratory is used to establish P availability in the field, indicated an increased P availability in (A), which was in contrast to reported decreased uptake of P in trees, decreased P concentration in needles and also in roots, as compared to (C). In six treatments investigated in Skogaby 32 P uptake rates were negatively correlated to the P/C of the microbial biomass. Acid phosphatase activity was always higher in (A) as compared to treatments where soluble P had been added and at two out of five times also higher than in (C ). High phosphatase activity levels were at least partly connected to large amounts of microbial biomass

  5. 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 ...

  6. Micromechanical modelling of mechanical behaviour and strength of wood

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Qing, Hai

    2008-01-01

    An overview of the micromechanical theoretical and numerical models of wood is presented. Different methods of analysis of the effects of wood microstructures at different scale levels on the mechanical behaviour, deformation and strength of wood are discussed and compared. Micromechanical models...

  7. 21 CFR 178.3800 - Preservatives for wood.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Preservatives for wood. 178.3800 Section 178.3800... Certain Adjuvants and Production Aids § 178.3800 Preservatives for wood. Preservatives may be safely used... to accomplish the technical effect of protecting the wood from decay, mildew, and water absorption...

  8. Wood fuelled boiler operating costs

    International Nuclear Information System (INIS)

    Sandars, D.L.

    1995-01-01

    This report is a management study into the operating costs of wood-fired boilers. Data obtained from existing wood-fired plant has been analysed and interpreted using the principles of machinery management and the science that underlies the key differences between this fuel and any other. A set of budgeting principles has been developed for the key areas of labour requirement, insurance, maintenance and repair and electricity consumption. Other lesser cost centres such as the provision of shelter and the effects of neglect and accidents have also been considered, and a model constructed. (author)

  9. Soil Microbial Community Changes in Wooded Mountain Pastures due to Simulated Effects of Cattle Grazing

    NARCIS (Netherlands)

    Kohler, F.; Hamelin, J.; Gillet, F.; Gobat, J.M.; Buttler, A.

    2005-01-01

    The effect of cattle activity on pastures can be subdivided into three categories of disturbances: herbage removal, dunging and trampling. The objective of this study was to assess separately or in combination the effect of these factors on the potential activities of soil microbial communities and

  10. Effect of water repellent preservatives and other wood treatments on restoration and durability of millwork

    Science.gov (United States)

    R. Sam Williams

    2001-01-01

    This report describes the long-term performance of painted window units that were placed outdoors near Madison, Wisconsin, in 1956. Covered in this report are the effects of the initial water repellent preservative (WRP) treatment during the first 6 years of exposure, a comparison of the water repellent effectiveness (WRE) ofthe WRP with the condition of the windows...

  11. Effectiveness of policy instruments for supporting the use of waste wood as a renewable energy resource in the Czech Republic

    International Nuclear Information System (INIS)

    Jehlickova, Bohumira; Morris, Richard

    2007-01-01

    This paper focuses on an examination of the government's strategy for encouraging the use of wood as a renewable fuel in Czech households. It examines the development of modern combustion technology and its impact on the environment. It describes the estimated requirement for wood by an average household and examines the overall availability of wood as a renewable fuel in the Czech Republic. The paper analyses in detail the policy instruments used by the Czech government to promote the use of this technology. It evaluates the impact of this policy on the users of the technology and practical achievements of the policy measures with respect to the overall objective that is the promotion of generation of renewable energy

  12. 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.

  13. Effect of raw material particle-size distribution on combustion characteristics of stem wood pellets; Paaverkan av partikelfraktionsfoerdelningen paa utbraenningshastigheten hos traepellets vid nyttjande av olika soenderdelningsmetoder

    Energy Technology Data Exchange (ETDEWEB)

    Israelsson, Samuel; Henriksson, Gunnar; Boman, Christoffer; Oehman, Marcus

    2007-01-15

    The objective of the project was to determine the effect of raw material particle-size distribution on combustion characteristics of stem wood pellets. Several well defined pellet qualities were produced from raw materials (stem wood of pine and spruce) which had both different particle-size distributions and were produced with different milling equipments (hammer mill/refiner). The pellets were produced in a traditional (bench-scale) pellet mill and in a laboratory pellet mill/press. The combustion characteristics of the individual pellets were determined in a laboratory scale oven. Char yield, -shrinkage, -density and the micro pore volume of the produced char were also determined. Differences in total conversion times of approximately 5 % at experimental condition relevant for typical pellets equipment were determined for the different pellet qualities. The underlying reasons for the obtained differences in the combustion characteristics between the different pellet qualities are discussed in the report

  14. Assessment of wood liquefaction in acidified ethylene glycol using experimental design methodology

    Energy Technology Data Exchange (ETDEWEB)

    Rezzoug, S.A. [Universite de La Rochelle, Lab. de Maitrise des Technologies Agro-Industrielles, La Rochelle, 17 (France); Capart, R. [Universite de Technologie de Compiegne, Dept. de Genie Chimique, Compiegne, 60 (France)

    2003-03-01

    The liquefaction of milled wood (Pinus pinaster) was effected in ethylene glycol acidified with small quantities of H{sub 2}SO{sub 4} as catalyst. The purpose of this paper is to evaluate the influence upon the liquefaction yield of the three operating variables, the maximal temperature (150-280 deg C), the reaction time at maximal temperature (20-60 min) and the amount of added H{sub 2}SO{sub 4} (0-1.5% on dry wood). The individual effects, as well as the interactions between operating variables, are investigated by using an experimental design methodology. From a Pareto chart, it appears that the most significant effects are clearly those of the maximum temperature and the interaction between acidity and temperature. Such effects can be graphically verified through response surfaces and contour line plots. From a regression analysis, the conversion rate of wood into liquid is simply expressed as a function of the operating variables by a polynomial containing quadratic terms. A statistical model seems particularly appropriate in the case of complex and multi-components, as wood, a kinetic model is nevertheless proposed for the liquefaction of micro-crystalline cellulose. This model accounts for the formation of a carbonaceous solid residue from the liquid product. Such an unwanted phenomenon obviously results in a lower yield in liquid product. (Author)

  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

    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.)

  16. 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.)

  17. Identifying and prioritizing indicators and effective solutions to optimization the use of wood in construction classical furniture by using AHP (Case study of Qom

    Directory of Open Access Journals (Sweden)

    Mohammad Ghofrani

    2017-02-01

    Full Text Available AbstractThe aim of this study was to identify and prioritize the indicators and provide effective solutions to optimize the use of wood in construction classical furniture using the analytic hierarchy process (case study in Qom. For this purpose, studies and results of other researchers and interviews with experts, the factors affecting the optimization of wood consumption were divided into 4 main categories and 23 sub-indicators. The importance of the sub after getting feedback furniture producers were determined by AHP. The results show that the original surface design and human resources are of great importance. In addition, among 23 sub-effective optimization of the use of wood in construction classical furniture, ergonomics, style, skill training and inlaid in classical furniture industry in order to weight the value of 0/247, 0/181, 0/124 and 0/087 are of paramount importance and the method of use of force specialist solutions were a priority.

  18. Effects of Wood Roughness, Light Pigments, and Water Repellent on the Color Stability of Painted Spruce Subjected to Natural and Accelerated Weathering

    Directory of Open Access Journals (Sweden)

    Ladislav Reinprecht

    2015-09-01

    Full Text Available This study examined the color stability of painted Norway spruce (Picea abies samples subjected to natural and accelerated weathering, using Duncan’s tests and correlation analyses. The following effects were studied: (1 the different initial roughness of the wood; (2 use of transparent or lightly-pigmented top-coat layers; and (3 the presence of the final water-repellent layer. Natural weathering at a 45° slope in an industrial zone lasted 104 weeks, whereas accelerated weathering in Xenotest with 0.55 W/m2 UV irradiation at 340 nm and sprayed water lasted 12 weeks. The color stability of painted spruce, measured in a CIE-L*a*b* system, was not, in the majority of cases, significantly affected by the initial roughness of the wood, the type of top-coat (WoodCare UV or PerlColor layer, or presence of the final water repellent (AquaStop layer. The light pine or larch pigments in the top-coat layers had positive color stabilizing effects. In their presence, the darkening (-L* and total color differences (E* of the painted samples dropped ca. 2.5 times during exterior weathering and ca. 5 times during Xenotest weathering. Samples painted with transparent coatings turned a reddish shade (+a* during the Xenotest, while those exposed to the exterior absorbed dirt and became more blue (-b*.

  19. Effects of eCG and progesterone on superovulation and embryo production in wood bison (Bison bison athabascae).

    Science.gov (United States)

    Palomino, J Manuel; Cervantes, Miriam P; Woodbury, Murray R; Mapletoft, Reuben J; Adams, Gregg P

    2017-06-01

    Experiments were done to determine if inclusion of eCG and progesterone in the superstimulation protocol will increase the ovarian response and embryo production in wood bison, and to provide preliminary information regarding the effect of season. In Experiment 1 (anovulatory season), bison (n=26) were synchronized by follicular ablation (Day -1) and given FSH on Days 0 and 2, and assigned to 3 groups: Progesterone (Days 0-4), eCG (Day 3), or progesterone+eCG. On Day 5, bison were given hCG and inseminated 12 and 24h later. Ova/embryos were collected 8days after hCG. In Experiment 2 (ovulatory season), bison (n=24) were synchronized and assigned randomly to two groups in which superstimulation was induced with FSH, either with or without eCG, as in Experiment 1. No differences among groups were found in ovarian response or embryo production in either experiment. The follicular count at wave emergence was positively correlated with the number of large follicles at the end of superstimulation in all groups. A significantly greater number of follicles present at wave emergence in the anovulatory vs. ovulatory season was associated with a greater number of CL at the time of embryo collection, but only half the number of freezable embryos. In conclusion, the number of transferable embryos collected (1-2/bison) was higher than in any previous report, but was not attributable to the inclusion of eCG or progesterone in the superovulatory protocol. The apparent effect of season on oocyte competence, and not superovulatory response, is worthy of further investigation. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Coal and wood fuel for electricity production: An environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F.W.M. [EPON, Zwolle (Netherlands)

    1997-12-31

    Waste wood from primary wood processing and demolition presents both a problem and a potential. If disposed in landfills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MW{sub e}) where 60 000 tonnes of waste and demolition wood will be used annually. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from an environmental liability to an environmental and economic asset. (author)

  1. Coal and wood fuel for electricity production: An environmentally sound solution for waste and demolition wood

    Energy Technology Data Exchange (ETDEWEB)

    Penninks, F W.M. [EPON, Zwolle (Netherlands)

    1998-12-31

    Waste wood from primary wood processing and demolition presents both a problem and a potential. If disposed in landfills, it consumes large volumes and decays, producing CH{sub 4}, CO{sub 2} and other greenhouse gases. As an energy source used in a coal fired power plant it reduces the consumption of fossil fuels reducing the greenhouse effect significantly. Additional advantages are a reduction of the ash volume and the SO{sub 2} and NO{sub x} emissions. The waste wood requires collection, storage, processing and burning. This paper describes a unique project which is carried out in the Netherlands at EPON`s Gelderland Power Plant (635 MW{sub e}) where 60 000 tonnes of waste and demolition wood will be used annually. Special emphasis is given to the processing of the powdered wood fuel. Therefore, most waste and demolition wood can be converted from an environmental liability to an environmental and economic asset. (author)

  2. Effects of air pollutants on the composition of stable carbon isotopes δ13C, of leaves and wood, and on leaf injury

    International Nuclear Information System (INIS)

    Martin, B.; Bytnerowicz, A.; Thorstenson, Y.R.

    1988-01-01

    Air pollutants are known to cause visible leaf injury as well as impairment of photosynthetic CO 2 fixation. Here we evaluate whether the effects on photosynthesis are large enough to cause changes in the relative composition of stable carbon isotopes, δ 13 C, of plant tissue samples, and, if so, how the changes relate to visual leaf injury. For that purpose, several woody and herbaceous plant species were exposed to SO 2 + O 3 and SO 2 + O 3 + NO 2 for one month. At the end of the fumigations, the plants were evaluated for visual leaf lesions, and δ 13 C of leaf tissue was determined. Woody plants generally showed less visual leaf injury and smaller effects on δ 13 C of pollutant exposure than did herbaceous plants. If δ 13 C was affected by pollutants, it became, with few exceptions, less negative. The data from the fumigation experiments were consistent with δ 13 C analyses of whole wood of annual growth rings from two conifer tree species, Pseudotsuga menziesii and Pinus strobus. These trees had been exposed until 1977 to exhaust gases from a gas plant at Lacq, France. Wood of both conifer species formed in the polluted air of 1972 to 1976 had less negative δ 13 C values than had wood formed in the much cleaner air in 1982 to 1986. No similar, time-dependent differences in δ 13 C of wood were observed in trees which had been continuously growing in clean air. Our δ 13 C data from both relatively short-term artificial exposures and long-term natural exposure are consistent with greater stomatal limitation of photosynthesis in polluted air than in clean air

  3. Wood density variations of Norway spruce (Picea abies (L. Karst. under contrasting climate conditions in southwestern Germany

    Directory of Open Access Journals (Sweden)

    Marieke van der Maaten-Theunissen

    2013-07-01

    Full Text Available We analyzed inter-annual variations in ring width and maximum wood density of Norway spruce (Picea abies (L. Karst. at different altitudes in Baden-Württemberg, southwestern Germany, to determine the climate response of these parameters under contrasting climate conditions. In addition, we compared maximum, average and minimum wood density between sites. Bootstrapped correlation coefficients of ring width and maximum wood density with monthly temperature and precipitation, revealed a different climate sensitivity of both parameters. Ring width showed strong correlations with climate variables in the previous year and in the first half of the growing season. Further, a negative relationship with summer temperature was observed at the low-altitude sites. Maximum wood density correlated best with temperature during the growing season, whereby strongest correlations were found between September temperature and maximum wood density at the high-altitude sites. Observed differences in maximum, average and minimum wood density are suggested to relate to the local climate; with lower temperatures and higher water availability having a negative effect on wood density. 

  4. On-line automatic detection of wood pellets in pneumatically conveyed wood dust flow

    Science.gov (United States)

    Sun, Duo; Yan, Yong; Carter, Robert M.; Gao, Lingjun; Qian, Xiangchen; Lu, Gang

    2014-04-01

    This paper presents a piezoelectric transducer based system for on-line automatic detection of wood pellets in wood dust flow in pneumatic conveying pipelines. The piezoelectric transducer senses non-intrusively the collisions between wood pellets and the pipe wall. Wavelet-based denoising is adopted to eliminate environmental noise and recover the collision events. Then the wood pellets are identified by sliding a time window through the denoised signal with a suitable threshold. Experiments were carried out on a laboratory test rig and on an industrial pneumatic conveying pipeline to assess the effectiveness and operability of the system.

  5. Wood smoke particle sequesters cell iron to impact a biological effect.

    Science.gov (United States)

    The biological effect of an inorganic particle (i.e., silica) can be associated with a disruption in cell iron homeostasis. Organic compounds included in particles originating from combustion processes can also complex sources of host cell iron to disrupt metal homeostasis. We te...

  6. Okanagan indoor wood burning appliance inventory survey

    International Nuclear Information System (INIS)

    2001-01-01

    A survey was conducted to determine the usage and nature of wood burning appliances used by residents in British Columbia's Okanagan region. The objective was to better understand this source of air quality concern and to facilitate strategic planning, guidelines and legislation. The survey also provides a baseline to track the effectiveness of any reduction strategies. It identifies the different types of wood burning appliances used in the community and presents residential options about potential bylaws to protect air quality. The receptivity of households to switch to more efficient wood burning appliances was also examined. The survey completes a portion of an overall emissions inventory for the Okanagan Valley. Environment Canada uses the particulate loading results to model the air quality in the airshed. Results showed that approximately 21 per cent of the households in the Okanagan use indoor wood burning appliances, and burn an average of 2.3 cords of wood each year. Only 11 per cent of the appliances are considered to have advanced burning technology. It is projected that the use of wood burning appliances in the Okanagan will increase by 5 to 7 per cent in the next 2 years. Most residents have good burning habits, but some improvements can still be made. Many residents are considering exchanging old wood burning appliances for clean burning technology appliances for environmental and health reasons. Most households would support a bylaw to control nuisance amounts of smoke from wood burning appliances. 20 tabs., 5 figs

  7. LCA-based optimization of wood utilization under special consideration of a cascading use of wood.

    Science.gov (United States)

    Höglmeier, Karin; Steubing, Bernhard; Weber-Blaschke, Gabriele; Richter, Klaus

    2015-04-01

    Cascading, the use of the same unit of a resource in multiple successional applications, is considered as a viable means to improve the efficiency of resource utilization and to decrease environmental impacts. Wood, as a regrowing but nevertheless limited and increasingly in demand resource, can be used in cascades, thereby increasing the potential efficiency per unit of wood. This study aims to assess the influence of cascading wood utilization on optimizing the overall environmental impact of wood utilization. By combining a material flow model of existing wood applications - both for materials provision and energy production - with an algebraic optimization tool, the effects of the use of wood in cascades can be modelled and quantified based on life cycle impact assessment results for all production processes. To identify the most efficient wood allocation, the effects of a potential substitution of non-wood products were taken into account in a part of the model runs. The considered environmental indicators were global warming potential, particulate matter formation, land occupation and an aggregated single score indicator. We found that optimizing either the overall global warming potential or the value of the single score indicator of the system leads to a simultaneous relative decrease of all other considered environmental impacts. The relative differences between the impacts of the model run with and without the possibility of a cascading use of wood were 7% for global warming potential and the single score indicator, despite cascading only influencing a small part of the overall system, namely wood panel production. Cascading led to savings of up to 14% of the annual primary wood supply of the study area. We conclude that cascading can improve the overall performance of a wood utilization system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Effect of wood ash and K-fertilization on {sup 137}Cs uptake by selected forest plants

    Energy Technology Data Exchange (ETDEWEB)

    Mandro, Yrii N. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Rosen, Klas [Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden); Vinichuk, Mykhailo M. [Zhytomyr State Technological University, P.O. Box 10005 Zhytomyr (Ukraine); Swedish University of Agricultural Sciences P.O. Box 7070 SE-750 07 Uppsala (Sweden)

    2014-07-01

    Accumulation {sup 137}Cs by different forest plants and trees after fertilization of soil with potassium and wood ash ({sup 137}Cs-contaminated and non-contaminated) in forest ecosystems of Ukraine contaminated by radionuclides after Chernobyl accident in 1986 was studied. Experiment is performed in Bazar forestry, Zhytomyr region, Ukraine, located about 70 km (51 deg. 5'35'' N, 29 deg. 18'56'' E) from Chernobyl NPP. Potassium fertilizer (KCl, wooden ash (Ash), and {sup 137}Cs-contaminated ash ({sup 137}CsAsh) in different combinations) were spread on the forest floor in April 2012 at a rate corresponding 100 kg/ha potassium. The experiment layout was as follows: 1- Control (no fertilizers were applied), 2- KCl, 3- Ash + KCl, 4- Ash + {sup 137}CsAsh, 5- Ash, 6- {sup 137}CsAsh + KCl. Samples (leaves and annual shoots) of blueberry (Vaccinium myrtillus), cowberry (Vaccinium vitis-idaea), rowan (Sorbus aucuparia), birch (Betula), buckthorn (Frangula) and oak (Quercus robur) and also mushrooms (fruit bodies of Russula, Lactarius, Cantharellus, Collybia etc.) and berries (blueberry and cowberry) were taken monthly from each treatment. Samples were measured for {sup 137}Cs with calibrated HPGe detectors. The results of the first year studies show variation of Transfer Factors (TF) for different plants and for the same plants on different treatments. The effect of fertilization was found for blueberry on Ash-applicated (TF = 0.0085 ± 0.0025), {sup 137}CsAsh + KCl-applicated (TF = 0.0105 ± 0.0060) and Ash + KCl-applicated (TF = 0.0123 ± 0.0058) treatments compared to Control (TF = 0.0163 ± 0.0092). Also good effect for rowan on Ash + KCl-applicated treatment (TF = 0.0067 ± 0.0024) compared to Control (TF = 0.0100 ± 0.0064). Effect was less obvious for birch on Ash + KCl-applicated treatment and for cowberry on Ash + KCl-applicated treatment. There was not found an obvious effect of fertilization for buckthorn. Positive effect of

  9. Fuel- and wood consumption surveys in developing countries: a proposal of an efficient low-cost method and the results of its application in eastern Ethiopia

    Energy Technology Data Exchange (ETDEWEB)

    Poschen, P.; Eiche, G.

    1986-01-01

    The method involves a preliminary survey to establish areas homogeneous for temperature and rainfall regime, natural vegetation, agricultural systems, wood fuel substitutes, housing and cooking habits. Locations are sampled within such areas to reflect variability in presence of forests and other fuel and wood resources, population density, and access to markets. Households are sampled within a location to cover variation in social structure. Results from a survey in the Hararghe highlands differ markedly from previous Ethiopia-wide estimates and show that remaining wood resources supply less than half of the fuel requirements. An effective community forestry programme is urgently required. (Refs. 9).

  10. Fast growing plantations for wood production – integration of ecological effects and economic perspectives

    Directory of Open Access Journals (Sweden)

    Michael eBredemeier

    2015-06-01

    Full Text Available Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRC with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyse, and model the effects of SRC-planting on landscape water budgets. To analyse the effects on the water budget a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modelling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems (AF on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a safety net to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication.

  11. Combining biochar, zeolite and wood vinegar for composting of pig manure: The effect on greenhouse gas emission and nitrogen conservation.

    Science.gov (United States)

    Wang, Quan; Awasthi, Mukesh Kumar; Ren, Xiuna; Zhao, Junchao; Li, Ronghua; Wang, Zhen; Wang, Meijing; Chen, Hongyu; Zhang, Zengqiang

    2018-04-01

    The effect of enhancing wood vinegar (WV) with a mixture of biochar (B) and zeolite (Z) to compost pig manure (PM) in a 130 L reactor was evaluated to determine the levels of greenhouse gas (GHG) and ammonia emissions. Six treatments were prepared in a 2:1 ratio of PM mixed with wheat straw (WS; dry weight basis): PM + WS (control), PM + WS + 10%B, PM + WS + 10%B + 10%Z, and PM + WS with 0.5%, 1.0% and 2.0%WV combined with 10%B + 10%Z. These were composted for 50 days, and the results indicated that the combined use of B, Z, and WV could shorten the thermophilic phase and improve the maturity of compost compared to the control treatment. In addition, WV mixed with B and Z could reduce ammonia loss by 64.45-74.32% and decrease CO 2 , CH 4 , and N 2 O emissions by 33.90-46.98%, 50.39-61.15%, and 79.51-81.10%, respectively. Furthermore, compared to treatments in which B and B + Z were added, adding WV was more efficient to reduce the nitrogen and carbon loss, and the 10%B + 10%Z + 2%WV treatment presented the lowest loss of carbon (9.16%) and nitrogen (0.75%). Based on the maturity indexes used, nitrogen conservation, and efficiency of GHG emissions reduction, the treatment 10%B + 10%Z + 2%WV is suggested for efficient PM composting. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Plasma enhanced modification of TMP fiber and its effect on tensile strength of wood fiber/PP composite

    Science.gov (United States)

    Sangyeob Lee; Todd F. Shupe; Chung Y. Hse

    2009-01-01

    Plasma-assisted surface treatment on thermomechanical pulp (TMP) fiber and polypropylene (PP) film was investigated to obtain interfacial adhesion at the wood fiber and PP interface. A metal plate between electrodes prevented thermal damage to the TMP fiber handsheets and PP film. Oxygen-plasma treatment provided better surface activation on the TMP fiber and...

  13. The effect of particle size and amount of inoculum on fungal treatment of wheat straw and wood chips

    NARCIS (Netherlands)

    Kuijk, van Sandra J.A.; Sonnenberg, Anton S.M.; Baars, Johan J.P.; Hendriks, Wouter H.; Cone, John W.

    2016-01-01

    Background: The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains (0.5, 1.5 or 3.0 % per g

  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. 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...

  16. Effects of Exterior Insulation on Moisture Performance of Wood-Frame Walls in the Pacific Northwest: Measurements and Hygrothermal Modeling

    Science.gov (United States)

    Samuel V. Glass; Borjen Yeh; Benjamin J. Herzog

    2016-01-01

    Continuous exterior insulation on above-grade walls is becoming more common in many parts of North America. It is generally accepted that exterior insulation provides advantages for energy performance, by reducing thermal bridging, and for moisture performance, by warming the wood structural members, thereby reducing the potential for wintertime moisture accumulation....

  17. Effect of cladding systems on moisture performance of wood-framed walls in a mixed-humid climate

    Science.gov (United States)

    S. Craig Drumheller; Charles G. Carll

    2010-01-01

    A 22-month field investigation of nine different north-and south-oriented wood-framed wall assemblies was conducted to determine the moisture performance of various wall construction types, most of which incorporated absorptive cladding. The study was conducted on the campus of the National Association of Home Builders (NAHB) Research Center, in Upper Marlboro, MD, 20...

  18. Effects of lime and wood ash on soil-solution chemistry, soil chemistry and nutritional status of a pine stand in northern Germany

    International Nuclear Information System (INIS)

    Ludwig, Bernard; Rumpf, Sabine; Mindrup, Michael; Meiwes, Karl-Josef; Khanna, Partap K.

    2002-01-01

    Lime and wood ash may be useful to improve acidic forest soils. A field experiment was conducted in a pine stand on a sandy podzol at Fuhrberg, Germany, which involved an application of dolomitic lime (3 t/ha) with three replications or wood ash (4.8 t/ha) without replications on the forest floor. During the 2 yr study period, lime affected the soil solution composition only slightly. Ash had a marked effect on solution chemistry of the mineral soil at 10 cm and the pH values dropped temporarily from 3.7 to 3.1. Nineteen months after the treatments, exchangeable calcium in the organic layer and mineral soil increased by 222 (lime addition) or 411 kg/ha (ash addition) and exchangeable magnesium increased by 101 (lime addition) or 39 kg/ha (ash addition). After ash addition, no marked change in heavy metal content was found below 4 cm of the organic layer. In the ash treatment, the potassium concentration of the 1-yr-old pine needles increased from 5.6 to 5.9 g/kg. This study suggests that ash from untreated wood may be recommended for amelioration of forest soils

  19. The effect of location and facility demand on the marginal cost of delivered wood chips from energy crops: A case study of the state of Tennessee

    International Nuclear Information System (INIS)

    Graham, R.L.; Liu, W.; Downing, M.; Noon, C.; Daly, M.; Moore, A.

    1995-01-01

    Cost-supply curves for delivered wood chips from short rotation woody crops were calculated for 21 regularly-spaced locations spanning the state of Tennessee. These curves were used to systematically evaluate the combined effects of location and facility demand on wood chip feedstock costs in Tennessee. The cost-supply curves were developed using BRAVO, a GIS-based decision support system which calculates marginal cost of delivering wood chips to a specific location given road network maps and maps of farmgate prices and supplies of woody chips from short rotation energy crops. Marginal costs of delivered chips varied by both facility location in the state and facility demand. Marginal costs were lowest in central Tennessee unless the facility demand was greater than 2.7 million dry Mg per year (3 million dry tons per year) in which case west Tennessee was the lowest cost region. Marginal costs rose rapidly with increasing facility demand in the mountainous eastern portion of the state. Transportation costs accounted for 18 to 29% of the delivered cost and ranged between $8 and $18/dry Mg ($7 and $16/dry ton). Reducing the expected farmer participation rate from 100% to 50% or 25% dramatically raised the marginal costs of feedstock supply in the east and central regions of the state. The analysis demonstrates the need to use geographically-specific information when projecting the potential costs and supplies of biomass feedstock

  20. Effects of gamma irradiation on larvae development of Monochamns altevnatus hope in packing wood

    International Nuclear Information System (INIS)

    Chen Wentuan; Zhong Guohua; Hu Meiying; Chen Xiaofan; Luo Zijuan; Pan Guoqi

    2006-01-01

    Effects of gamma irradiation on Monochamns altevnatus Hope larvae were studied. The results showed that mortality of Monchamns altevnatus Hope on the 21 st day reached over 90% by a dose of 500 Gy treatment. The pupating rate decreased below 10% with the dose higher than 400 Gy, while the abnormal pupae began to appear at this dose, and there are no eclosion at 450 Gy. The relationship between death rate and absorbed dose could be described by dose-response curve for tested pest. (authors)

  1. Fast Growing Plantations for Wood Production - Integration of Ecological Effects and Economic Perspectives.

    Science.gov (United States)

    Bredemeier, Michael; Busch, Gerald; Hartmann, Linda; Jansen, Martin; Richter, Falk; Lamersdorf, Norbert P

    2015-01-01

    Biomass crops are perceived as a feasible means to substitute sizeable amounts of fossil fuel in the future. A prospect of CO2 reduction (resp. CO2 neutrality) is credited to biomass fuels, and thus a potential contribution to mitigate climate change. Short rotation coppices (SRCs) with fast growing poplar and willow trees are an option for producing high yields of woody biomass, which is suitable for both energetic and material use. One negative effect that comes along with the establishment of SRC may be a decrease in groundwater recharge, because high rates of transpiration and interception are anticipated. Therefore, it is important to measure, analyze, and model the effects of SRC-planting on landscape water budgets. To analyze the effects on the water budget, a poplar SRC plot was studied by measuring hydrological parameters to be used in the hydrological model WaSim. Results reveal very low or even missing ground water recharge for SRC compared to agricultural land use or grassland, especially succeeding dry years. However, this strong effect on plot level is moderated on the larger spatial scale of catchment level, for which the modeling was also performed. In addition to water, nutrient fluxes and budgets were studied. Nitrogen is still a crucial issue in today's agriculture. Intensive fertilization or increased applications of manure from concentrated livestock breeding are often leading to high loads of nitrate leaching, or enhanced N2O emissions to the atmosphere on arable crop fields. SRC or agroforestry systems on former crop land may offer an option to decrease such N losses, while simultaneously producing woody biomass. This is mainly due to the generally smaller N requirements of woody vegetation, which usually entail no need for any fertilization. The trees supply deep and permanent rooting systems, which can be regarded as a "safety net" to prevent nutrient leaching. Thus, SRC altogether can help to diminish N eutrophication. It is important to

  2. Effects of feed process variables on Hanford Vitrification Plant performance

    International Nuclear Information System (INIS)

    Farnsworth, R.K.; Peterson, M.E.; Wagner, R.N.

    1987-01-01

    As a result of nuclear defense activities, high-level liquid radioactive wastes have been generated at the Hanford Site for over 40 yr. The Hanford Waste Vitrification Plant (HWVP) is being proposed to immobilize these wastes in a waste form suitable for disposal in a geologic repository. Prior to vitrification, the waste will undergo several conditioning steps before being fed to the melter. The effect of certain process variables on the resultant waste slurry properties must be known to assure processability of the waste slurry during feed preparation. Of particular interest are the rheological properties, which include the yield stress and apparent viscosity. Identification of the rheological properties of the slurry is required to adequately design the process equipment used for feed preparation (agitators, mixing tanks, concentrators, etc.). Knowledge of the slurry rheological properties is also necessary to establish processing conditions and operational limits for maximum plant efficiency and reliability. A multivariable study was performed on simulated HWVP feed to identify the feed process variables that have a significant impact on rheology during processing. Two process variables were evaluated in this study: (a) the amount of formic acid added to the feed and (b) the degree of shear encountered by the feed during processing. The feed was physically and rheologically characterized at various stages during feed processing

  3. 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...

  4. 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.

  5. 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

  6. Synergetic Effects of Alcohol/Water Mixing on the Catalytic Reductive Fractionation of Poplar Wood

    Energy Technology Data Exchange (ETDEWEB)

    Renders, Tom; Van den Bosch, Sander; Vangeel, Thijs; Ennaert, Thijs; Koelewijn, Steven-Friso; Van den Bossche, Gil; Courtin, Christophe M.; Schutyser, Wouter; Sels, Bert F.

    2016-12-05

    One of the foremost challenges in lignocellulose conversion encompasses the integration of effective lignin valorization in current carbohydrate-oriented biorefinery schemes. Catalytic reductive fractionation (CRF) of lignocellulose offers a technology to simultaneously produce lignin-derived platform chemicals and a carbohydrate-enriched pulp via the combined action of lignin solvolysis and metal-catalyzed hydrogenolysis. Herein, the solvent (composition) plays a crucial role. In this contribution, we study the influence of alcohol/water mixtures by processing poplar sawdust in varying MeOH/water and EtOH/water blends. The results show particular effects that strongly depend on the applied water concentration. Low water concentrations enhance the removal of lignin from the biomass, while the majority of the carbohydrates are left untouched (scenario A). Contrarily, high water concentrations favor the solubilization of both hemicellulose and lignin, resulting in a more pure cellulosic residue (scenario B). For both scenarios, an evaluation was made to determine the most optimal solvent composition, based on two earlier introduced empirical efficiency descriptors (denoted LFDE and LFFE). According to these measures, 30 (A) and 70 vol % water (B) showed to be the optimal balance for both MeOH/water and EtOH/water mixtures. This successful implementation of alcohol/water mixtures allows operation under milder processing conditions in comparison to pure alcohol solvents, which is advantageous from an industrial point of view.

  7. Assessing the Effects of Climate on Global Fluvial Discharge Variability

    Science.gov (United States)

    Hansford, M. R.; Plink-Bjorklund, P.

    2017-12-01

    Plink-Bjorklund (2015) established the link between precipitation seasonality and river discharge variability in the monsoon domain and subtropical rivers (see also Leier et al, 2005; Fielding et al., 2009), resulting in distinct morphodynamic processes and a sedimentary record distinct from perennial precipitation zone in tropical rainforest zone and mid latitudes. This study further develops our understanding of discharge variability using a modern global river database created with data from the Global Runoff Data Centre (GRDC). The database consists of daily discharge for 595 river stations and examines them using a series of discharge variability indexes (DVI) on different temporal scales to examine how discharge variability occurs in river systems around the globe. These indexes examine discharge of individual days and monthly averages that allows for comparison of river systems against each other, regardless of size of the river. Comparing river discharge patterns in seven climate zones (arid, cold, humid subtropics, monsoonal, polar, rainforest, and temperate) based off the Koppen-Geiger climate classifications reveals a first order climatic control on discharge patterns and correspondingly sediment transport. Four groupings of discharge patterns emerge when coming climate zones and DVI: persistent, moderate, seasonal, and erratic. This dataset has incredible predictive power about the nature of discharge in fluvial systems around the world. These seasonal effects on surface water supply affects river morphodynamics and sedimentation on a wide timeframe, ranging from large single events to an inter-annual or even decadal timeframe. The resulting sedimentary deposits lead to differences in fluvial architecture on a range of depositional scales from sedimentary structures and bedforms to channel complex systems. These differences are important to accurately model for several reasons, ranging from stratigraphic and paleoenviromental reconstructions to more

  8. Instrumental variable methods in comparative safety and effectiveness research.

    Science.gov (United States)

    Brookhart, M Alan; Rassen, Jeremy A; Schneeweiss, Sebastian

    2010-06-01

    Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial.

  9. Instrumental variable methods in comparative safety and effectiveness research†

    Science.gov (United States)

    Brookhart, M. Alan; Rassen, Jeremy A.; Schneeweiss, Sebastian

    2010-01-01

    Summary Instrumental variable (IV) methods have been proposed as a potential approach to the common problem of uncontrolled confounding in comparative studies of medical interventions, but IV methods are unfamiliar to many researchers. The goal of this article is to provide a non-technical, practical introduction to IV methods for comparative safety and effectiveness research. We outline the principles and basic assumptions necessary for valid IV estimation, discuss how to interpret the results of an IV study, provide a review of instruments that have been used in comparative effectiveness research, and suggest some minimal reporting standards for an IV analysis. Finally, we offer our perspective of the role of IV estimation vis-à-vis more traditional approaches based on statistical modeling of the exposure or outcome. We anticipate that IV methods will be often underpowered for drug safety studies of very rare outcomes, but may be potentially useful in studies of intended effects where uncontrolled confounding may be substantial. PMID:20354968

  10. 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...

  11. 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....

  12. Effects of wood fiber surface chemistry on strength of wood–plastic composites

    Energy Technology Data Exchange (ETDEWEB)

    Migneault, Sébastien, E-mail: sebastien.migneault@uqat.ca [University of Quebec in Abitibi-Temiscamingue (UQAT), 445 boulevard de l’Université, Rouyn-Noranda, Québec J9X 5E4 (Canada); Koubaa, Ahmed, E-mail: ahmed.koubaa@uqat.ca [UQAT (Canada); Perré, Patrick, E-mail: patrick.perre@ecp.fr [École centrale de Paris, Grande Voie des Vignes, F-92 295 Chatenay-Malabry Cedex (France); Riedl, Bernard, E-mail: Bernard.Riedl@sbf.ulaval.ca [Université Laval, 2425 rue de la Terrasse, Québec City, Québec G1V 0A6 (Canada)

    2015-07-15

    Highlights: • Infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed variations of surface chemical characteristics according to fiber origin. • Surface chemical characteristics of fibers could partly explain the differences in mechanical properties of the wood–plastic composites. • Fibers with carbohydrate rich surface led to stronger wood–plastic composites because the coupling between the matrix and fibers using coupling agent is achieved with polar sites mostly available on carbohydrates. • Conversely, lignin or extractives rich surface do not have oxidized functions for the esterification reaction with coupling agent and thus led to wood–plastic composites with lower mechanical properties. • Other factors such as mechanical interlocking and fiber morphology interfere with the effects of fiber surface chemistry. - Abstract: Because wood–plastic composites (WPC) strength relies on fiber-matrix interaction at fiber surface, it is likely that fiber surface chemistry plays an important role in WPC strength development. The objective of the present study is to investigate the relationships between fiber surface chemical characteristics and WPC mechanical properties. Different fibers were selected and characterized for surface chemical characteristics using X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). WPC samples were manufactured at 40% fiber content and with six different fibers. High density polyethylene was used as matrix and maleated polyethylene (MAPE) was used as compatibility agent. WPC samples were tested for mechanical properties and fiber-matrix interface was observed with scanning electron microscope. It was found WPC strength decreases as the amount of unoxidized carbon (assigned to lignin and extractives) measured with XPS on fiber surface increases. In the opposite case, WPC strength increases with increasing level of oxidized carbon (assigned to carbohydrates) on fiber surface. The same

  13. Effects of wood fiber surface chemistry on strength of wood–plastic composites

    International Nuclear Information System (INIS)

    Migneault, Sébastien; Koubaa, Ahmed; Perré, Patrick; Riedl, Bernard

    2015-01-01

    Highlights: • Infrared spectroscopy and X-ray photoelectron spectroscopy analyses showed variations of surface chemical characteristics according to fiber origin. • Surface chemical characteristics of fibers could partly explain the differences in mechanical properties of the wood–plastic composites. • Fibers with carbohydrate rich surface led to stronger wood–plastic composites because the coupling between the matrix and fibers using coupling agent is achieved with polar sites mostly available on carbohydrates. • Conversely, lignin or extractives rich surface do not have oxidized functions for the esterification reaction with coupling agent and thus led to wood–plastic composites with lower mechanical properties. • Other factors such as mechanical interlocking and fiber morphology interfere with the effects of fiber surface chemistry. - Abstract: Because wood–plastic composites (WPC) strength relies on fiber-matrix interaction at fiber surface, it is likely that fiber surface chemistry plays an important role in WPC strength development. The objective of the present study is to investigate the relationships between fiber surface chemical characteristics and WPC mechanical properties. Different fibers were selected and characterized for surface chemical characteristics using X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). WPC samples were manufactured at 40% fiber content and with six different fibers. High density polyethylene was used as matrix and maleated polyethylene (MAPE) was used as compatibility agent. WPC samples were tested for mechanical properties and fiber-matrix interface was observed with scanning electron microscope. It was found WPC strength decreases as the amount of unoxidized carbon (assigned to lignin and extractives) measured with XPS on fiber surface increases. In the opposite case, WPC strength increases with increasing level of oxidized carbon (assigned to carbohydrates) on fiber surface. The same

  14. 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....

  15. 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

  16. Effect of Variable Manning Coefficients on Tsunami Inundation

    Science.gov (United States)

    Barberopoulou, A.; Rees, D.

    2017-12-01

    Numerical simulations are commonly used to help estimate tsunami hazard, improve evacuation plans, issue or cancel tsunami warnings, inform forecasting and hazard assessments and have therefore become an integral part of hazard mitigation among the tsunami community. Many numerical codes exist for simulating tsunamis, most of which have undergone extensive benchmarking and testing. Tsunami hazard or risk assessments employ these codes following a deterministic or probabilistic approach. Depending on the scope these studies may or may not consider uncertainty in the numerical simulations, the effects of tides, variable friction or estimate financial losses, none of which are necessarily trivial. Distributed manning coefficients, the roughness coefficients used in hydraulic modeling, are commonly used in simulating both riverine and pluvial flood events however, their use in tsunami hazard assessments is primarily part of limited scope studies and for the most part, not a standard practice. For this work, we investigate variations in manning coefficients and their effects on tsunami inundation extent, pattern and financial loss. To assign manning coefficients we use land use maps that come from the New Zealand Land Cover Database (LCDB) and more recent data from the Ministry of the Environment. More than 40 classes covering different types of land use are combined into major classes such as cropland, grassland and wetland representing common types of land use in New Zealand, each of which is assigned a unique manning coefficient. By utilizing different data sources for variable manning coefficients, we examine the impact of data sources and classification methodology on the accuracy of model outputs.

  17. Biomass Determination Using Wood Specific Gravity from Increment Cores

    Science.gov (United States)

    Michael C. Wiemann; G. Bruce Williamson

    2013-01-01

    Wood specific gravity (SG) is one of the most important variables used to determine biomass. Measurement of SG is problematic because it requires tedious, and often difficult, sampling of wood from standing trees. Sampling is complicated because the SG usually varies nonrandomly within trees, resulting in systematic errors. Off-center pith and hollow or decayed stems...

  18. 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 ...

  19. 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...

  20. Instrumental variables estimates of peer effects in social networks.

    Science.gov (United States)

    An, Weihua

    2015-03-01

    Estimating peer effects with observational data is very difficult because of contextual confounding, peer selection, simultaneity bias, and measurement error, etc. In this paper, I show that instrumental variables (IVs) can help to address these problems in order to provide causal estimates of peer effects. Based on data collected from over 4000 students in six middle schools in China, I use the IV methods to estimate peer effects on smoking. My design-based IV approach differs from previous ones in that it helps to construct potentially strong IVs and to directly test possible violation of exogeneity of the IVs. I show that measurement error in smoking can lead to both under- and imprecise estimations of peer effects. Based on a refined measure of smoking, I find consistent evidence for peer effects on smoking. If a student's best friend smoked within the past 30 days, the student was about one fifth (as indicated by the OLS estimate) or 40 percentage points (as indicated by the IV estimate) more likely to smoke in the same time period. The findings are robust to a variety of robustness checks. I also show that sharing cigarettes may be a mechanism for peer effects on smoking. A 10% increase in the number of cigarettes smoked by a student's best friend is associated with about 4% increase in the number of cigarettes smoked by the student in the same time period. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. 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)

  2. Pelly Crossing wood chip boiler

    Energy Technology Data Exchange (ETDEWEB)

    1985-03-11

    The Pelly wood chip project has demonstrated that wood chips are a successful fuel for space and domestic water heating in a northern climate. Pelly Crossing was chosen as a demonstration site for the following reasons: its extreme temperatures, an abundant local supply of resource material, the high cost of fuel oil heating and a lack of local employment. The major obstacle to the smooth operation of the boiler system was the poor quality of the chip supply. The production of poor quality chips has been caused by inadequate operation and maintenance of the chipper. Dull knives and faulty anvil adjustments produced chips and splinters far in excess of the one centimetre size specified for the system's design. Unanticipated complications have caused costs of the system to be higher than expected by approximately $15,000. The actual cost of the project was approximately $165,000. The first year of the system's operation was expected to accrue $11,600 in heating cost savings. This estimate was impossible to confirm given the system's irregular operation and incremental costs. Consistent operation of the system for a period of at least one year plus the installation of monitoring devices will allow the cost effectiveness to be calculated. The wood chip system's impact on the environment was estimated to be minimal. Wood chip burning was considered cleaner and safer than cordwood burning. 9 refs., 6 figs., 6 tabs.

  3. Application of FTIR spectroscopy to the characterization of archeological wood.

    Science.gov (United States)

    Traoré, Mohamed; Kaal, Joeri; Martínez Cortizas, Antonio

    2016-01-15

    Two archeological wood samples were studied by attenuated total reflectance Fourier transform infrared (FTIR-ATR) spectroscopy. They originate from a shipwreck in Ribadeo Bay in the northwest of Spain and from a beam wood of an old nave of the Cathedral of Segovia in the central Spain. Principal component analysis was applied to the transposed data matrix (samples as columns and spectral bands as rows) of 43 recorded spectra (18 in the shipwreck and 25 in the beam wood). The results showed differences between the two samples, with a larger proportion of carbohydrates and smaller proportion of lignin in the beam than in the shipwreck wood. Within the beam wood, lignin content was significantly lower in the recent than the old tree rings (P=0.005). These variations can be attributed to species differences between the two woods (oak and pine respectively), with a mixture of guaiacyl and syringyl in hardwood lignin, whereas softwood lignin consists almost exclusively of guaiacyl moieties. The influence of environmental conditions on the FTIR fingerprint was probably reflected by enhanced oxidation of lignin in aerated conditions (beam wood) and hydrolysis of carbohydrates in submerged-anoxic conditions (shipwreck wood). Molecular characterization by analytical pyrolysis of selected samples from each wood type confirmed the interpretation of the mechanisms behind the variability in wood composition obtained by the FTIR-ATR. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. 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.)

  5. 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...

  6. 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 (...

  7. 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...

  8. 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…

  9. 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.)

  10. 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...

  11. Country-Specific Effects of Climate Variability on Human Migration

    Science.gov (United States)

    Gray, Clark; Wise, Erika

    2016-01-01

    Involuntary human migration is among the social outcomes of greatest concern in the current era of global climate change. Responding to this concern, a growing number of studies have investigated the consequences of short to medium-term climate variability for human migration using demographic and econometric approaches. These studies have provided important insights, but at the same time have been significantly limited by lack of expertise in the use of climate data, access to cross-national data on migration, and attention to model specification. To address these limitations, we link data on internal and international migration over a 6-year period from 9,812 origin households in Kenya, Uganda, Nigeria, Burkina Faso and Senegal to high-resolution gridded climate data from both station and satellite sources. Analyses of these data using several plausible specifications reveal that climate variability has country-specific effects on migration: Migration tends to increase with temperature anomalies in Uganda, tends to decrease with temperature anomalies in Kenya and Burkina Faso, and shows no consistent relationship with temperature in Nigeria and Senegal. Consistent with previous studies, precipitation shows weak and inconsistent relationships with migration across countries. These results challenge generalizing narratives that foresee a consistent migratory response to climate change across the globe. PMID:27092012

  12. Country-Specific Effects of Climate Variability on Human Migration.

    Science.gov (United States)

    Gray, Clark; Wise, Erika

    2016-04-01

    Involuntary human migration is among the social outcomes of greatest concern in the current era of global climate change. Responding to this concern, a growing number of studies have investigated the consequences of short to medium-term climate variability for human migration using demographic and econometric approaches. These studies have provided important insights, but at the same time have been significantly limited by lack of expertise in the use of climate data, access to cross-national data on migration, and attention to model specification. To address these limitations, we link data on internal and international migration over a 6-year period from 9,812 origin households in Kenya, Uganda, Nigeria, Burkina Faso and Senegal to high-resolution gridded climate data from both station and satellite sources. Analyses of these data using several plausible specifications reveal that climate variability has country-specific effects on migration: Migration tends to increase with temperature anomalies in Uganda, tends to decrease with temperature anomalies in Kenya and Burkina Faso, and shows no consistent relationship with temperature in Nigeria and Senegal. Consistent with previous studies, precipitation shows weak and inconsistent relationships with migration across countries. These results challenge generalizing narratives that foresee a consistent migratory response to climate change across the globe.

  13. Effect of Steam Activation on Development of Light Weight Biomorphic Porous SiC from Pine Wood Precursor

    Science.gov (United States)

    Manocha, Satish M.; Patel, Hemang; Manocha, L. M.

    2013-02-01

    Biomorphic SiC materials with tailor-made microstructure and properties similar to ceramic materials manufactured by conventional method are a new class of materials derived from natural biopolymeric cellulose templates (wood). Porous silicon carbide (SiC) ceramics with wood-like microstructure have been prepared by carbothermal reduction of charcoal/silica composites at 1300-1600 °C in inert Ar atmosphere. The C/SiO2 composites were fabricated by infiltrating silica sol into porous activated biocarbon template. Silica in the charcoal/silica composite, preferentially in the cellular pores, was found to get transformed in forms of fibers and rods due to shrinkage during drying. The changes in the morphology of resulting porous SiC ceramics after heat treatment to 1600 °C, as well as the conversion mechanism of wood to activated carbon and then to porous SiC ceramic have been investigated using scanning electron microscope, x-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. Activation of carbon prior to silica infiltration has been found to enhance conversion of charcoal to SiC. The pore structure is found to be uniform in these materials than in those made from as-such charcoal/silica composites. This provides a low-cost and eco-friendly route to advanced ceramic materials, with near-net shape potential.

  14. Effect of wood ash on leaf and shoot anatomy, photosynthesis and carbohydrate concentrations in birch on a cutaway peatland.

    Science.gov (United States)

    Aguraijuja, Karin; Klõšeiko, Jaan; Ots, Katri; Lukjanova, Aljona

    2015-07-01

    Trees in cutaway peatland are growing in difficult conditions. Fertilization with nutrient-rich wood ash helps improve growth conditions. Photosynthesis and carbohydrate concentration along leaf anatomy were studied on plots treated with 10 and 5 t ha(-1) wood ash (WA10 and WA5) and on untreated (Control) plot to explain the physiological background of the differences in tree growth. The leaves from WA10 had the largest leaf area, total thickness, the thickest mesophyll and also significantly larger average values of all anatomical parameters of the shoots. The photosynthetic assimilation was significantly higher on treated plots at 200 and 400 ppm CO2 levels. In leaves on the treated plots, the sucrose concentration was lower while that of starch was higher than in trees on untreated soil. The differences in the maximum photosynthesis were relatively small. At unit ground, the leaf area provided for a wood ash-treated tree an efficient surface for CO2 assimilation, light interception and some starch storage during the growing period.

  15. Effects of interannual climate variability on tropical tree cover

    NARCIS (Netherlands)

    Holmgren, M.; Hirota, M.; Nes, van E.H.; Scheffer, M.

    2013-01-01

    Climatic warming is substantially intensifying the global water cycle1 and is projected to increase rainfall variability2. Using satellite data, we show that higher climatic variability is associated with reduced tree cover in the wet tropics globally. In contrast, interannual variability in

  16. Wood quality changes caused by mineral fertilization

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2014-06-01

    Full Text Available The diverse and important use of wood from fast growth eucalyptus plantations requires the analysis of the effect of mineral fertilizers on wood quality. The objective of this study was to evaluate the anatomical characteristics and wood density from Eucalyptus grandis trees (3 m x 2 m spacing fertilized with potassium and sodium (at planting, 6 th and 12th month. Fifteen (15 6 years old eucalyptus trees were selected (5 trees/treatment, cut and wood samples at DBH (1,3 m were taken for anatomical characteristics (fiber and vessels and wood density analysis. Results showed that eucalyptus trees treated with mineral fertilizers did not show significant alteration in average wood density, with radial profile model common to all three treatments, characterized by a values increase in the region next to the pith, toward to bark. Mineral fertilization influenced wood anatomical characteristics: treatment with sodium was characterized by thinner walls and lumen larger diameter; in treatment with potassium, larger vessels were detected.

  17. Photostabilisation of the 'wood-clearcoatings' systems with UV absorbers: correlation with their effect on the glass transition temperature

    Energy Technology Data Exchange (ETDEWEB)

    Aloui, F [Laboratoire d' Etude et de Recherches sur le Materiau Bois LERMAB UMR-A1093 INRA/ENGREF/UHP - Faculte des Sciences et Techniques, BP 239 - 54506 Vandoeuvre les Nancy (France); Ahajji, A [Laboratoire d' Etude et de Recherches sur le Materiau Bois LERMAB UMR-A1093 INRA/ENGREF/UHP - Faculte des Sciences et Techniques, BP 239 - 54506 Vandoeuvre les Nancy (France); Irmouli, Y [Laboratoire d' Etude et de Recherches sur le Materiau Bois LERMAB UMR-A1093 INRA/ENGREF/UHP - Faculte des Sciences et Techniques, BP 239 - 54506 Vandoeuvre les Nancy (France); George, B [Laboratoire d' Etude et de Recherches sur le Materiau Bois LERMAB UMR-A1093 INRA/ENGREF/UHP - Faculte des Sciences et Techniques, BP 239 - 54506 Vandoeuvre les Nancy (France); Charrier, B [IUT des Pays de l' Adour, Departement SGM-Bois, 371, rue du ruisseau, 40004 Mont de Marsan (France); Merlin, A [Laboratoire d' Etude et de Recherches sur le Materiau Bois LERMAB UMR-A1093 INRA/ENGREF/UHP - Faculte des Sciences et Techniques, BP 239 - 54506 Vandoeuvre les Nancy (France)

    2006-05-15

    In an application-oriented study, the effective transition temperature T{sub g} of organic wood-clearcoatings between a hard, glassy state and a viscoelastic and rubbery state is measured. The value of T{sub g} is important in the eventual development of cracks and a thermomechanical analysis is used to study the photostabilisation performance of some UV absorbers. A weathering exposure test suggests that certain organic UV absorbers have quite a low T{sub g} and may inhibit the crack formation, in contrast with inorganic UV absorbers.

  18. 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

  19. Learning effect and test-retest variability of pulsar perimetry.

    Science.gov (United States)

    Salvetat, Maria Letizia; Zeppieri, Marco; Parisi, Lucia; Johnson, Chris A; Sampaolesi, Roberto; Brusini, Paolo

    2013-03-01

    To assess Pulsar Perimetry learning effect and test-retest variability (TRV) in normal (NORM), ocular hypertension (OHT), glaucomatous optic neuropathy (GON), and primary open-angle glaucoma (POAG) eyes. This multicenter prospective study included 43 NORM, 38 OHT, 33 GON, and 36 POAG patients. All patients underwent standard automated perimetry and Pulsar Contrast Perimetry using white stimuli modulated in phase and counterphase at 30 Hz (CP-T30W test). The learning effect and TRV for Pulsar Perimetry were assessed for 3 consecutive visual fields (VFs). The learning effect were evaluated by comparing results from the first session with the other 2. TRV was assessed by calculating the mean of the differences (in absolute value) between retests for each combination of single tests. TRV was calculated for Mean Sensitivity, Mean Defect, and single Mean Sensitivity for each 66 test locations. Influence of age, VF eccentricity, and loss severity on TRV were assessed using linear regression analysis and analysis of variance. The learning effect was not significant in any group (analysis of variance, P>0.05). TRV for Mean Sensitivity and Mean Defect was significantly lower in NORM and OHT (0.6 ± 0.5 spatial resolution contrast units) than in GON and POAG (0.9 ± 0.5 and 1.0 ± 0.8 spatial resolution contrast units, respectively) (Kruskal-Wallis test, P=0.04); however, the differences in NORM among age groups was not significant (Kruskal-Wallis test, P>0.05). Slight significant differences were found for the single Mean Sensitivity TRV among single locations (Duncan test, PPulsar Perimetry CP-T30W test did not show significant learning effect in patients with standard automated perimetry experience. TRV for global indices was generally low, and was not related to patient age; it was only slightly affected by VF defect eccentricity, and significantly influenced by VF loss severity.

  20. 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...