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

    OpenAIRE

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

    2009-01-01

    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.

  2. Effects of the position in a stem on the variability of tracheids in spruce (Picea abies /L./ Karst. with the occurrence of reaction wood

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    Vladimír Gryc

    2010-01-01

    Full Text Available The paper is aimed at the field of the microscopic structure of wood dealing with the description of the most important anatomic element in softwood – tracheids in a stem with the occurrence of reaction wood. Significant changes of tracheids were found along the height and radius of a stem. There were statistically significant differences between particular annual rings (variability along the stem radius. The height of a stem was also statistically significant. On the basis of the results obtained 3D models were created (for zones compression wood, opposite wood and site wood; models for radial dimension an early-wood tracheid and late-wood tracheid depicting changes in transverse dimensions of the spruce tracheid in relation to its position in a stem. Structure of ring with compression wood was studied too. It was observed that the ring with occurrence of compression wood has a following structure: early wood tracheids at the beginning of the growing season, transitional tracheids, compression tracheids and at the end of an annual ring typical late wood tracheids. The rings with compression wood show more tracheids as compared with annual rings from the opposite side.

  3. 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.

  4. Effects of the position in a stem on the variability of tracheids in spruce (Picea abies /L./ Karst.) with the occurrence of reaction wood

    OpenAIRE

    Vladimír Gryc; Hanuš Vavrčík

    2010-01-01

    The paper is aimed at the field of the microscopic structure of wood dealing with the description of the most important anatomic element in softwood – tracheids in a stem with the occurrence of reaction wood. Significant changes of tracheids were found along the height and radius of a stem. There were statistically significant differences between particular annual rings (variability along the stem radius). The height of a stem was also statistically significant. On the basis of the results ob...

  5. Physiological Effects of Touching Wood

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    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.

  6. 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....

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

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    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.

  8. Effect of Wood Preservatives on Surface Properties of Coated Wood

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    Turgay Ozdemir

    2015-01-01

    Full Text Available Effect of wood preservatives (waterborne and organicborne on the performance of surface finishing properties is investigated. Sapwood of scots pine, (Pinus sylvestris L., oriental beech (Fagus orientalis Lipsky, and chestnut (Castanea sativa Mill. specimens (300 × 100 × 15 mm along the grain were impregnated with aqueous solution of 2% CCA, 2% Tanalith E, 1% boric acid, and Immersol aqua. Surface roughness, dry film thickness, adhesion strength, gloss measurement, scratch, and abrasion resistance were determined according to related standards for treated and untreated samples. The results indicated that surface roughness and adhesion strength depended on wood species and the chemical composition of preservatives. Generally, waterborne wood preservatives increased the surface roughness of wood while the organic-based wood preservatives decreased it. The organic-based wood preservatives decreased adhesion but they increased gloss value. Wood preservatives did not affect the scratch resistance which was found to depend on properties of the coating. All the wood preservatives increased abrasion resistance.

  9. Acetosolv pulping of Eucalyptus globulus wood. Pt. 1. The effect of operational variables on pulp yield, pulp lignin content and pulp potential glucose content

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, G. [Dept. of Chemical Engineering, Univ. of Santiago de Compostela (Spain); Antorrena, G. [Dept. of Chemical Engineering, Univ. of Santiago de Compostela (Spain); Gonzalez, J. [Dept. of Chemical Engineering, Univ. of Santiago de Compostela (Spain)

    1995-07-01

    The HCl-catalysed delignification of Eucalyptus globulus wood by aqueous acetic acid was optimized in accordance with an incomplete 3x3x3 factorial design with HCl concentration (0-0.05%), temperature (120-160 C) and reaction time (1-4 h) as independent variables and pulp yield, pulp lignin content and pulp potential glucose content as dependent variables. Empirical equations derived from the results satisfactorily predict the influence of the independent variables on these characteristics of the delignification process and the delignified pulps. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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

  11. Decay Resistance Variability of European Wood Species Thermally Modified by Industrial Process

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    Kevin CANDELIER

    2017-06-01

    Full Text Available Thermal modification is now considered as a new ecofriendly industrial wood modification process improving mainly the material decay resistance and its dimensional stability. Most industrial thermal treatment processes use convection heat transfer which induces sometimes heterogeneous treatment temperature propagation within the oven and lead to the heterogeneity in treatment efficiency. Thus, it is common that treatment is not completely effective on several stack boards, in a same batch. The aim of this paper was to study the decay resistance variability of various European wood species thermally modified. Thermal modifications were performed around 240°C during 4h, on about 10m3 of 27x152x2000mm3 wood planks placed in an industrial oven having a volume of 20m3 , on the following wood species: spruce, ash, beech and poplar. All of the tests concerning the decay resistance were carried out in the laboratory using untreated beech and pine woods as reference materials. An agar block test was used to determine the resistance of thermally modified woods, leached beforehand according to EN 84 standard or not, to brownrot and white-rot fungi, according to XP CEN/TS 15083-1. A large selection of treated wood samples was tested in order to estimate the variability of treatment efficiency. Thermal treatment increased the biological durability of all leached and un-leached modified wood samples, compared with native wood species. The treatment temperature of 240°C used in this study is sufficient to reach durability classes ‘‘durable’’ or ‘‘very durable’’ for the four wood species. However, the dispersion of weight loss values, due to the fungal attacks was very important and showed a large variability of the durability of wood which has been treated in a single batch. These results showed that there is a substantial need to develop process control and indicator in order to insure that the quality of treated timber is properly evaluated

  12. The effect of chemical treatment of wood flour on some of properties of wood plastic composite

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    Saeed Ismaeilimoghadam

    2016-12-01

    Full Text Available This research aimed to investigate the effect of chemical treatment of wood flour on some of physical, mechanical and morphological properties of wood plastic composite. Chemical treatment of wood flour at 7 levels without treatment, acetylation, benzoylation, mercerization, magnesium hydroxide, calcium hydroxide and warm water treatment were considered as variable factors. For evaluate reaction of wood flour with chemical materials, weight percent gain (WPG were calculated. After chemical treatment, Wood flour and polypropylene with weight ratio of 60 to 40 and 4 per hundred compound (phc of coupling agent mixed in the extruder device and then the specimens were fabricated by injection molding method. Then mechanical tests Included tensile, flexural and impact strength and physical examination, including water absorption and thickness swelling was performed on specimens according to (ASTM standard. Also to study the morphology of the composites, scanning electron microscopy (SEM was used. The results showed that by chemical treatment the mechanical strength increased and physical properties such as water absorption and thickness swelling decreased. Also the highest chemical treatments of wood flour was related to the banzylation treatment. As well as obtained results of scanning electron microscopy was indicate improve in cross linking between fibers and polymeric matrix on effect of chemical treatment, so that in treatment samples exiting of fibers into the matrix not observed.

  13. Exposure to wood smoke increases arterial stiffness and decreases heart rate variability in humans.

    Science.gov (United States)

    Unosson, Jon; Blomberg, Anders; Sandström, Thomas; Muala, Ala; Boman, Christoffer; Nyström, Robin; Westerholm, Roger; Mills, Nicholas L; Newby, David E; Langrish, Jeremy P; Bosson, Jenny A

    2013-06-06

    Emissions from biomass combustion are a major source of indoor and outdoor air pollution, and are estimated to cause millions of premature deaths worldwide annually. Whilst adverse respiratory health effects of biomass exposure are well established, less is known about its effects on the cardiovascular system. In this study we assessed the effect of exposure to wood smoke on heart rate, blood pressure, central arterial stiffness and heart rate variability in otherwise healthy persons. Fourteen healthy non-smoking subjects participated in a randomized, double-blind crossover study. Subjects were exposed to dilute wood smoke (mean particle concentration of 314±38 μg/m3) or filtered air for three hours during intermittent exercise. Heart rate, blood pressure, central arterial stiffness and heart rate variability were measured at baseline and for one hour post-exposure. Central arterial stiffness, measured as augmentation index, augmentation pressure and pulse wave velocity, was higher after wood smoke exposure as compared to filtered air (p smoke compared to filtered air. Acute exposure to wood smoke as a model of exposure to biomass combustion is associated with an immediate increase in central arterial stiffness and a simultaneous reduction in heart rate variability. As biomass is used for cooking and heating by a large fraction of the global population and is currently advocated as a sustainable alternative energy source, further studies are required to establish its likely impact on cardiovascular disease. ClinicalTrials.gov, NCT01488500.

  14. Effects of wood fiber characteristics on mechanical properties of wood/polypropylene composites

    Science.gov (United States)

    Nicole M. Stark; Robert E. Rowlands

    2003-01-01

    Commercial wood flour, the most common wood-derived filler for thermoplastics, is produced in a mixture of particle sizes and generally has a lower aspect ratio than wood and other natural fibers. To understand how wood flour and fiber characteristics influence the mechanical properties of polypropylene composites, we first investigated the effect of different sizes of...

  15. Variability of European beech wood density as influenced by interactions between tree-ring growth and aspect

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    Daniela Diaconu

    2016-02-01

    Full Text Available Background: Wood density is considered to be the most important predictor of wood quality but despite its importance, diffuse-porous tree species have been the subject of only a limited number of studies. The importance of European beech forests for Central Europe calls for profound research to examine the potential impact of a warmer climate on the quality of beech timber. Methods: In this study we analysed the influence of tree-ring width and tree-ring age on the wood density of beech, and whether the wood density response to these two parameters is modified by aspect. A linear mixed-effects model for wood density was constructed for mean density data measured with high frequency densitometry on stem discs from 72 beech trees sampled from two different aspects (northeast -NE and southwest -SW of a valley in southwestern Germany. Results: Part of the variability of mean annual wood density was explained by cambial age: an increase in cambial age resulted in an increase in mean wood density. Tree-ring width and aspect had only a small influence on wood density. Wood density on the SW aspect was lower than on the NE with a difference of approximately 0.006 g/cm3. The between-tree variability was very high. Conclusions: The significant interaction between cambial age and aspect reflects the importance of site conditions at older tree ages: with increasing cambial age the difference between aspects becomes stronger. Our results give a better understanding of the importance of site conditions on the wood quality of beech. Keywords: Fagus sylvatica, HF densitometry, Wood quality, Wood density, Aspect

  16. 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.

  17. 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

  18. 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...

  19. 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...

  20. Optimization of processing variables in wood-rubber composite panel manufacturing technology.

    Science.gov (United States)

    Jun, Zhao; Xiang-Ming, Wang; Jian-Min, Chang; Kai, Zheng

    2008-05-01

    The feasibility of manufacturing wood-rubber functional composite panels with a polymeric methylene diphenyl diisocyanate (PMDI) and urea-formaldehyde (UF) combination binder system was investigated. Mechanisms of interacted independent variables (board density, pressing time and pressing temperature) for effect on board properties were opened out. The board performance was evaluated by measuring internal bond (IB) strength, modulus of rupture (MOR) and modulus of elasticity (MOE). The test results were statistically analyzed by using response surface method (RSM) of Design-Expert software to determine the significant independent variables that influenced board properties. A mathematical simulation or response surface models were developed to predict the board properties (MOR, MOE and IB). The results showed that board density and some interactions between the experimental variables were significant factors that influenced board mechanical properties. The suggested optimal board manufacturing conditions were about 170 degrees C, for pressing temperature, 300 s for pressing time, and 1000 g cm(-3) for board density.

  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. Effects of Wood Ash on Soil Fungi

    DEFF Research Database (Denmark)

    Cruz Paredes, Carla

    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...... were used. However, the AM colonization was as abundant and active as in the untreated plots. In the Norway spruce experiment, ECM mycelial production and nitrogen (N) retention capacity remained unaffected. Moreover, ECM fungal richness, diversity and community composition did not change with wood ash......Reutilizing biomass ash on soil has been proposed to counteract soil acidity and to save fertilizer inputs by recycling valuable nutrients contained in biomass ash such as calcium (Ca), magnesium (Mg) and phosphorus (P). However, the heavy metal content of biomass ashes, such as cadmium (Cd...

  3. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

    is a renewable resource makes it predestinated for what is considered ´sustainable architecture´. But the reality is less linear and there are serious traps: In fact the lecture shows by examples that it is much easier to build very unsustainable buildings in wood than the other way round! Where does the wood...

  4. The effect of tension wood on roughness of poplar wood and its modification by steaming

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    اصغر طارمیان

    2016-12-01

    Full Text Available In this research, the effect of tension wood on the roughness of poplar wood in tangential and radial sections was investigated. Steaming at120 ̊C for 30 and 60 min was aslo applied to reduce the roughness. The potential use of roughness measurement technique for macroscopically detection of tension wood was one of the main objectives of this research. Before roughness measurement and for accurate sampling, the detection of tension wood was carried out using Herzberg reagent and microscopic studies. The roughness of samples was measured by stylus profilometer at 12 % moisture content and the surface quality was also studied by stereo-microscope. Results showed that there is no significant difference in the radial and tangential roughness between tension and normal wood. No difference was also observed between the roughness of tangential and radial sections of both types of woods. In contrast, stereo-microscopic studies clearly showed the higher roughness of tension wood. Steaming for 30 min increased the roughness but the treatment for 60 min had a decreasing effect on the roughness of both types of woods. Overall, it can be concluded that the roughness measurement technique cannot be used as a suitable method to nondestructively detect the poplar tension wood.

  5. Lifetime and residual strength of wood subjected to static and variable load

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1996-01-01

    The DVM-theory (Damaged Viscoelastic Material) previously developed by the author to predict lifetime of wood subjected to static loads is further developed in this paper such that variable loads can also be considered. Lifetime (real time or number of cycles) is predicted as a function of load...... is successfully compared with data from experiments representing different wood products. Algorithms and master graphs are developed which can be used in fatigue design of wood products in general. These graphs are valid for any creep behavior (relaxation, moisture content) and materials quality (grading...

  6. Penetration and Effectiveness of Micronized Copper in Refractory Wood Species.

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    Chiara Civardi

    Full Text Available 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(OH2, 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(OH2 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.

  7. 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)

  8. 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....

  9. Effects of Acid Deposition on Wood

    Science.gov (United States)

    Mark Knaebe

    2013-01-01

    Since acid deposition increases the rate of deterioration of unpainted wood, it can also affect the performance of paint applied to this weathered wood. In tests conducted near Madison, Wisconsin, smooth-planed wood was allowed to weather before painting. Exposure for as little as 2 weeks shortened the service life of the subsequently applied paint. The paint bond was...

  10. 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.

  11. 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...

  12. Effects of shear coupling on shear properties of wood

    Science.gov (United States)

    Jen Y. Liu

    2000-01-01

    Under pure shear loading, an off-axis element of orthotropic material such as pure wood undergoes both shear and normal deformations. The ratio of the shear strain to a normal strain is defined as the shear coupling coefficient associated with the direction of the normal strain. The effects of shear coupling on shear properties of wood as predicted by the orthotropic...

  13. The effect of wind on burning rate of wood cribs

    Science.gov (United States)

    Sara McAllister; Mark Finney

    2016-01-01

    Wood cribs are often used as ignition sources for room fire tests. A wood crib may also apply to studies of burning rate in wildland fires, because wildland fuel beds are porous and three dimensional. A unique aspect of wildland fires is the ubiquitous presence of wind. However, very little is known about what effect the increased ventilation has on the...

  14. Effect of various organic solvents on rheological properties of wood

    Science.gov (United States)

    Sugimoto, H.; Miki, T.; Nishida, M.; Kanayama, K.

    2008-08-01

    Plastics depend strongly on underground resources such as petroleum. To produce novel wood materials as a substitute for plastics, the fine structure of wood impregnated with various organic solvents—ethylene glycol(EG), tri-ethylene glycol, dimethyl folmamyde(DMF), dimethyl sulfoxide(DMSO)—was examined. The dynamic Young's modulus and tanδ—frequency curves of every sample indicated that the relaxation process due to the glass transition of lignin in wood exists. To obtain basic data about the processes, the apparent activation energies (ΔE) were examined. The values of ΔE of the sample impregnated with water and EG were higher than that with DMSO and DMF. These results may not only be due to the hydrogen bonding per volume, but also the confined effect in wood. In fact, the CP/MAS spectra of EG—Wood sample indicates the existence of slow movement EG at higher temperatures of the melting point.

  15. Effect of Altitude and Aspect on Wood-Water Relations of Beech (Fagus orientalis Lipsky. Wood

    Directory of Open Access Journals (Sweden)

    Elif Topaloğlu

    2013-11-01

    Full Text Available Effects of altitude and aspect on wood-water relations in Oriental beech (Fagus orientalis Lipsky. were studied. Study area divided into five altitude steps and two aspect groups, total of 20 trees were cut off. In order to determine the wood-water relations; volume density value, fiber saturation point, maximum moisture content, and shrinkage and swelling percentages were determined. According to results, with 95% significance level (p<0,05, altitude affects volume density value, shrinkage and swelling percentages, fiber saturation point and maximum moisture content; aspect affects volume density value, tangential and radial shrinkage percentages, volumetric shrinkage percentage, tangential and longitudinal swelling percentages, fiber saturation point and maximum moisture content while it has no effect on longitudinal shrinkage percentage, radial and volumetric swelling percentages. Results demonstrated that northern aspect and first altitude step has the lowest values, thus, this aspect and altitude step making a suitable place for this tree species to be used as solid wood.

  16. the effects of some manufacturing variables on the properties

    African Journals Online (AJOL)

    ES Obe

    The effects of type of wood furnish particle-board, specific gravity and press closing speed on properties of resultant particleboard were ... using factorial analysis and regression analysis with Dummy Variables. Most variables and/or their ..... H.D. Effects of Particle Size and. Shape on Strength and Dimensional Stability.

  17. Modeling simulation and control of the wood drying process. Part 2: Variable control structure

    Energy Technology Data Exchange (ETDEWEB)

    Tarasiewicz, S.; Ding, F. [Laval Univ., Sainte-Foy, Quebec (Canada). Dept. of Mechanical Engineering; Leger, F. [Forintek Canada Corp. East Div., Sainte-Foy, Quebec (Canada)

    1998-07-01

    The wood drying process (WDP), is described by an internal model (IM), contains four drying periods and a few different structures of mathematical model. For a given state variables measured accuracy, using piecewise linear approximation to analyze operating functions of these structures, a horizon of WDP can be determined. Based on this feature, an observer is established, which can produce estimated state variables and estimated operating functions, thereby, the time delay can be compensated. Applying a minimum consumption of energy and minimum drying time with the constrain of wood quality as the performance index, a reference system model (RSM) is created and a switching space will be calculated to decide reference trajectories of WDP.

  18. Damage of Wood-Concrete Composite subjected to variable hygrometric conditions

    Directory of Open Access Journals (Sweden)

    Bornert M.

    2010-06-01

    Full Text Available This paper discusses the factors influencing the durability of glued assemblies of wood and cementitious material under variable hygrometric conditions. The composite specimens are composed of cement paste connected to plywood using epoxy glue. The cement paste is subjected to autogeneous shrinkage and the wood is subjected to imbibition test. Plywood is used so that the swelling deformations due to the imbibition process are parallel to the connection plane. Swelling strains in wood are related to the water content measured by gammadensimetry technique. Global strains above and below the glue interface have been measured and have been compared to the free strains. We showed that there are restrained deformations at the glue interface and that the cement paste is damaged. Local strains have been characterized by means of the digital image correlation technique. We showed in particular that the deformations in wood are related to the microstructure of the layers of plywood and that the restrained deformations at the glue interface lead to a bending of the cement paste. In the case of strong adhesion properties, this bending induces cracking in cement paste.

  19. Toxicological and histopathological effects of cheese wood, Alstonia ...

    African Journals Online (AJOL)

    Toxicological and histopathological effects of cheese wood, Alstonia boonei de wild stem bark powder used as cowpea protectant against cowpea bruchid, Callosobruchus maculatu (Fab.) [coleoptera: chrysomelidae] on albino rats.

  20. Effect of Production Conditions of Wood Powder on Bending Properties of Wood Powder Molding Material without Adhesive

    Science.gov (United States)

    Imanishi, Hiroshi; Soma, Naho; Yamashita, Osamu; Miki, Tsunehisa; Kanayama, Kozo

    The effect of production conditions of wood powder on the bending properties of wood powder molding material was investigated. Wood powder was produced by milling wood into powder under conditions of different temperatures (25°C, 100°C) and moisture contents (0%MC, about 30%MC). Molding materials were produced from wood powder in stream atmosphere of high temperature and high pressure (175°C, 900kPa) using self-bonding ability of the wood powder. Adhesives, such as a synthetic resin, were not used. To evaluate the bending properties of the molding materials, the modulus of elasticity and the bending strength were examined by static three-point bending test. As for the characteristic of wood particle, in case of wood particle produced by milling wood under a condition of high temperature and high moisture content (100°C and about 30%MC), tendencies for intercellular layer to be exposed on surface of a particle and for the aspect ratio of particles to be large were confirmed. And in that case, the molding material showed the highest value in modulus of elasticity and bending strength. It is highly probable that the inprovement of the self-bonding ability of wood powder and the increase of the aspect ratio of wood particle take part in the improvement of strength properties of molding material.

  1. 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...

  2. Wood as an adherend

    Science.gov (United States)

    Bryan H. River; Charles B. Vick; Robert H. Gillespie

    1991-01-01

    Wood is a porous, permeable, hygroscopic, orthotropic, biological composite material of extreme chemical diversity and physical intricacy. Table 1.1 provides an overview of the may variables, including wood variables, that bear on the bonding and performance of wood in wood joints and wood-based materials. Of particular note is the fact that wood properties vary...

  3. 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.

  4. 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.

  5. 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...

  6. The Effect of Wood Dust on Lung Function of Woodworkers in Na ...

    African Journals Online (AJOL)

    Background The wood industry is one of the occupations where exposure to wood dust has been shown to lead to chronic lung diseases long after such exposure has ceased. This study assessed the effect of wood dust and other irritants on lung function of wood workers in Na'ibawa market, Kano. Method Using a ...

  7. The effect of different wood varnishes on surface color properties of heat treated wood materials

    Directory of Open Access Journals (Sweden)

    Hüseyin Pelit

    2017-11-01

    Full Text Available This study investigates the effects of different wood varnishes on the surface color properties of heat treated wood. Samples prepared from Oriental beech (Fagus orientalis L. and Scots pine (Pinus sylvestris L. are subjected to heat treatment at 190, 200, and 210 ° C for 2 h. Sample surfaces are then covered with cellulosic (SZ, synthetic (ST, polyurethane (PU, and water-based (SB wood varnishes, and the color properties of samples are determined according to the three-dimensional CIEL*a*b* color space. Results show a decrease in the L* and b* values of samples by 64% and 70%, respectively, depending on the process temperature after heat treatment. The a* value increases by up to 96% for Scots pine samples and up to 56% for beech samples. Color values of heat treated samples change significantly after varnish is applied; L* values of all samples are reduced compared to unvarnished samples and samples are seen to darken. However, the a* value of heat treated Scots pine samples increases significantly after varnishing, while that of heat-treated beech samples at high temperatures (200 and 210 °C generally decreases. Nevertheless, the b* value decreases significantly in both wood species subjected to application of PU and ST varnishes, and the total color change (ΔE* of varnished specimens is generally higher for samples heat-treated at 200 °C. Results show that ST varnish has the largest effect on color change and SB varnish has the smallest effect. The use of SB varnishes is thus preferable when it is necessary to preserve the color of samples from either species following heat treatment.

  8. 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 (...

  9. 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.

  10. THE EFFECTS OF WOOD RAW MATERIAL PRODUCTION ACTIVITIES ON WOOD QUALITY CLASSES

    Directory of Open Access Journals (Sweden)

    Saliha Ünver

    2005-04-01

    Full Text Available Wood raw material production without barked round is 3.5 billion m3 in the world. According to their amounts, industrial wood products set out log, fiber chip and pulp wood respectively in. Wood raw material produced in Turkey is not enough for market demand, so 9% of industrial wood demand has been imported. For this reason, the quality loses are as important as the quantity loses, which can be occurred during wood raw material production. Both preserving of continuity of forest sources and saving of addition to country economy are important during wood raw material production. To reduce the quality losses on the wood raw material is possible with the usage of developed techniques, taking into consideration sector demand, storing of wood raw material by suitable conditions and being worked the experienced worker.

  11. Population effects and variability.

    Science.gov (United States)

    Dorne, Jean Lou; Amzal, Billy; Bois, Frédéric; Crépet, Amélie; Tressou, Jessica; Verger, Philippe

    2012-01-01

    Chemical risk assessment for human health requires a multidisciplinary approach through four steps: hazard identification and characterization, exposure assessment, and risk characterization. Hazard identification and characterization aim to identify the metabolism and elimination of the chemical (toxicokinetics) and the toxicological dose-response (toxicodynamics) and to derive a health-based guidance value for safe levels of exposure. Exposure assessment estimates human exposure as the product of the amount of the chemical in the matrix consumed and the consumption itself. Finally, risk characterization evaluates the risk of the exposure to human health by comparing the latter to with the health-based guidance value. Recently, many research efforts in computational toxicology have been put together to characterize population variability and uncertainty in each of the steps of risk assessment to move towards more quantitative and transparent risk assessment. This chapter focuses specifically on modeling population variability and effects for each step of risk assessment in order to provide an overview of the statistical and computational tools available to toxicologists and risk assessors. Three examples are given to illustrate the applicability of those tools: derivation of pathway-related uncertainty factors based on population variability, exposure to dioxins, dose-response modeling of cadmium.

  12. 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 ...

  13. 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 ...

  14. Evaluating effects of thinning on wood quality in southeast Alaska

    Science.gov (United States)

    Eini C. Lowell; Dennis P. Dykstra; Robert A. Monserud

    2012-01-01

    We examined the effect of thinning on wood quality of western hemlock (Tsuga heterophylla) and Sitka spruce (Picea sitchensis) located on Prince of Wales and Mitkof Islands in southeast Alaska. Sample trees came from paired plots (thinned versus unthinned) in eight naturally regenerated, mixed stands of young-growth western...

  15. 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

  16. Penetrability of nano-wollastonite into the poplar wood and its effect on wood durability and dimensional stability

    Directory of Open Access Journals (Sweden)

    davoud efhamisisi

    2017-08-01

    Full Text Available In recent years, much attention has been paid to nano technology for improving wood defects. Wollastonite as a mineral is commonly used in the production of plastic, ceramic and concrete. Wollastonite production in nano scale has increased interest in using it. Recently, a large number of studies have been carried out in Iran aiming to improve durability, dimensional stability, and flammability of wood and wood products using nano wollastonite. Based on the promising results obtained in these researchs, this study was conducted as a complementary investigation to verify nano-wollastonite penetrability into the wood as well as its effects on biological durability and dimensional stability. The results showed that nano-wollastonite could not penetrate into the xylem since wood texture serves as a filter against it. The treated samples with nano-wollastonite showed partly resistance against white rotting fungus, but this was lost after a short-time leaching. Nano-wollastonite had no effect on the water absorption and volumetric shrinkage of treated samples. Base on the results of this study, nano-wollastonite is not recommended for wood impregnation industry, at least when raw wood is concerned.

  17. Effects of radio transmitters on migrating wood thrushes

    Science.gov (United States)

    Powell, L.A.; Krementz, D.G.; Lang, J.D.; Conroy, M.J.

    1998-01-01

    We quantified the effects of radio transmitters on Wood Thrushes (Hylocichla mustelina) using 4 yr of banding and telemetry data from Piedmont National Wildlife Refuge, Georgia. Flight performance models suggest that the 1.6-g transmitter shortens the migratory range of Wood Thrushes by only 60 km, and the estimated migratory range is adequate to accomplish migration even with limited fat stores. We used two strengths of line, 5- and 9-kg test-strength braided Dacron, to attach the transmitters using the thigh-harness method. We recaptured 13 returning radio-marked Wood Thrushes, seven of which were still marked. Six of the seven birds marked with the 5-kg test harnesses lost their transmitters within 1 yr while all six of the 9-kg test harnesses were still attached up to 21 mo later. Radio-marking did not reduce the return rates of adults and immatures, and the transmitters did not cause radio-marked birds to lose more mass than banded-only birds. Wood Thrushes can successfully carry a transmitter during migration with no detectable negative effects. We recommend continued use of the thigh-harness method, but we encourage the use of 5-kg cotton line.

  18. Contrasting effects of wood ash application on microbial community structure, biomass and processes in drained forested peatlands.

    Science.gov (United States)

    Björk, Robert G; Ernfors, Maria; Sikström, Ulf; Nilsson, Mats B; Andersson, Mats X; Rütting, Tobias; Klemedtsson, Leif

    2010-09-01

    The effects of wood ash application on soil microbial processes were investigated in three drained forested peatlands, which differed in nutrient status and time since application. Measured variables included the concentrations of soil elements and phospholipid fatty acids (PLFAs), net nitrogen (N) mineralization, nitrification and denitrification enzyme activity, potential methane (CH(4)) oxidation, CH(4) production and microbial respiration kinetics. Wood ash application had a considerable influence on soil element concentrations. This mirrored a decrease in the majority of the microbial biomarkers by more than one-third in the two oligotrophic peatlands, although the microbial community composition was not altered. The decreases in PLFAs coincided with reduced net ammonification and net N mineralization. Other measured variables did not change systematically as a result of wood ash application. No significant changes in microbial biomass or processes were found in the mesotrophic peatland, possibly because too little time (1 year) had elapsed since the wood ash application. This study suggests that oligotrophic peatlands can be substantially affected by wood ash for a period of at least 4 years after application. However, within 25 years of the wood ash application, the microbial biomass seemed to have recovered or adapted to enhanced element concentrations in the soil.

  19. A classification proposal for coefficients of variation in Eucalyptus experiments involving survival, growth and wood quality variables

    Directory of Open Access Journals (Sweden)

    Freddy Mora

    2016-01-01

    Full Text Available ABSTRACT The objective of this study was to present a classification proposal for coefficients of variation (CV in Eucalyptus experiments, aiming at providing a useful tool for experiments involving growth, survival and wood quality traits. Ninety-four studies were selected from a search for peer-reviewed journals yielding a total of 508 data. The CVs were classified as low, moderate, high and very high. The mean, standard deviation, maximum and minimum values, skewness and kurtosis were estimated to describe the distribution shape. The Shapiro-Wilk test confirmed that all variables satisfied the assumption of normality (p < 0.05. The results indicated that the growth traits had the highest variability, being variables strongly affected by the environment. In contrast, all variables related to wood quality (except extractives had the lowest range of CVs. In summary, the classification proposed in this report provides a useful tool for researchers interested in estimating the accuracy of their experiments.

  20. Effects of material parameters on the diffusion and sorption properties of wood-flour/polypropylene composites

    Science.gov (United States)

    Vera Steckel; Craig Merrill Clemons; Heiko Thoemen

    2007-01-01

    Composites of wood in a thermoplastic matrix (wood–plastic composites) are considered a low maintenance solution to using wood in outdoor applications. Knowledge of moisture uptake and transport properties would be useful in estimating moisture-related effects such as fungal attack and loss of mechanical strength. Our objectives were to determine how material...

  1. Wood chip mulch thickness effects on soil water, soil temperature, weed growth, and landscape plant growth

    Science.gov (United States)

    Wood chip mulches are used in landscapes to reduce soil water evaporation and competition from weeds. A study was conducted over a three-year period to determine soil water content at various depths under four wood chip mulch treatments and to evaluate the effects of wood chip thickness on growth of...

  2. The termicidal effect of some plant material on some selected wood ...

    African Journals Online (AJOL)

    ... 89.06% follow by M. acuminata extract with 58%, while C. albidum extracts had the least absorption. The weight loss was significantly lower in G. arborea wood. It was observed that D. stramonium water extracts and J. curcas were found effective for wood preservation in other to elongate the life span of wood material.

  3. 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...

  4. THE BLENDING EFFECT OF COALITE, COCONUT SHELL CHARCOAL AND GELAM WOOD CHARCOAL ON CALORIFIC VALUE

    OpenAIRE

    Nukman; Riman Sipahutar; Irsyadi Yani; Taufik Arief

    2014-01-01

    The aim of this research is to scrutinize the effect of blend solid fuels consisting of coalite, coconut shell charcoal and gelam wood charcoal on calorific value. Coalite is the solid fuels made from coal that is mined from the earth, while coconuts shell charcoal and gelam wood charcoal are processed from natural plants. Coalite, coconut shell charcoal and gelam wood charcoal are solid fuels which was obtained from carbonization process or pyrolitic process of fuel material. Gelam wood char...

  5. 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.

  6. 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.

  7. Evaluation of Binding Effects in Wood Flour Board Containing Ligno-Cellulose Nanofibers.

    Science.gov (United States)

    Kojima, Yoichi; Isa, Akiko; Kobori, Hikaru; Suzuki, Shigehiko; Ito, Hirokazu; Makise, Rie; Okamoto, Masaki

    2014-09-22

    Wood-based materials are used extensively in residual construction worldwide. Most of the adhesives used in wood-based materials are derived from fossil resources, and some are not environmentally friendly. This study explores nanofiber technology as an alternative to such adhesives. Previous studies have shown that the three-dimensional binding effects of cellulose nanofiber (CNF), when mixed with wood flour, can significantly improve the physical and mechanical properties of wood flour board. In this study, ligno-cellulose nanofibers (LCNF) were fabricated by wet disk milling of wood flour. Composite boards of wood flour and LCNF were produced to investigate the binding effect(s) of LCNF. The fabrication of LCNF by disk milling was simple and effective, and its incorporation into wood flour board significantly enhanced the physical and mechanical properties of the board.

  8. The variability of the wood-anatomy in large and small genera

    NARCIS (Netherlands)

    Janssonius, H.H.

    1950-01-01

    In the “Mikrographie des Holzes der auf Java vorkommenden Baumarten” I described 991 kinds of wood. Several of these belong to large genera, the majority to small. I found remarkably wide variations in the wood-anatomy of several specimens belonging to a single species of a large genus. These

  9. 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...

  10. Lifetime and residual strength of wood subjected to static and variable load

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    1997-01-01

    The DVM-theory (Damaged Viscoelastic Material) previously developed by the author to predict lifetime of wood subjected to static loads is further developed in this paper such that harmonic load variations can also be considered. Lifetime (real time or number of cycles) is predicted as a function...... is successfully compared with data from experiments representing different wood products. Master graphs are developed which can be used in fatigue design of wood products in general. These graphs are valid for any creep behavior (relaxation, moisture content) and materials quality (grading, strength level.......It is strongly emphasised throughout the paper that reliable mechanical durability studies on wood cannot be made if the influence of wood rheology is disregarded. Lifetime predicted by Palmgren-Miner methods may cause considerably overestimated time to failure, especially at low frequencies. Results from...

  11. Effect of Composite Action on the Strength of Wood Roofs

    Directory of Open Access Journals (Sweden)

    Ivan A. Campos Varela

    2015-01-01

    Full Text Available Engineering certification for the installation of solar photovoltaic modules on wood roofs is often denied because existing wood roofs do not meet current building codes. Rather than requiring expensive structural retrofits, we desire to show that many roofs are actually sufficiently strong if the effect of composite action produced by joist-sheathing interaction is considered. In a series of laboratory experiments using a limited number of two-by-four wood joists with and without sheathing panels, conventionally sheathed stud-grade joists, surprisingly, exhibited between 18% and 63% higher nominal strength than similar bare joists. To explain this strength increase, a simple model was developed to predict the strengths of the nailed partially composite sections, but the model only justifies a 1.4% to 3.8% increase in bending strength of joists with an allowable bending strength of 1000 psi. More testing is indicated to resolve this discrepancy between laboratory results and analytical modeling results. In addition to elucidating nonlinear partial composite behavior of existing roof systems, this paper shows that, with minor changes in roof framing practices, strength increases of 70% or more are achievable, compared to the strengths of conventionally sheathed joists.

  12. The effect of water salinity on wood breakdown in semiarid Mediterranean streams.

    Science.gov (United States)

    Gómez, Rosa; Asencio, Antonia Dolores; Picón, José María; Del Campo, Rubén; Arce, María Isabel; Del Mar Sánchez-Montoya, María; Suárez, María Luisa; Vidal-Abarca, María Rosario

    2016-01-15

    Saline streams occur naturally and they are distributed worldwide, particularly in arid and semiarid regions, but human activities have also increased their number in many parts of the world. Little attention has been paid to assess increasing salt effects on organic matter decomposition. The objectives of this study were to analyse wood breakdown rates and how salinity affects them in 14 streams that exemplify a natural salinity gradient. We also analysed the effect of this gradient on changes in wood chemical composition, fungal biomass and microbial activity. Our results showed low breakdown rates (0.0010-0.0032 d(-1)), but they fell within the same range as those reported in freshwater streams when a similar woody substrate was used. However, salinity had a negative effect on the breakdown rates and fungal biomass along the salinity gradient, and led to noticeable changes in wood composition. Water salinity did not affect microbial activity estimated using hydrolysis of fluorescein diacetate. Variation in breakdown rates and fungal biomass across streams was mediated mainly by salinity, and later by stream discharge. Despite the role of fungi in stick breakdown, the potential wood abrasion by salts must be analysed in detail to accurately understand the effect of increasing salinity on organic matter breakdown. Finally, our results indicate that increased salinity worldwide by human activities or by the global warming would imply organic matter breakdown and mineralisation slowing down, even in natural saline streams. However, because many variables are implicated, the final effect of climatic change on organic matter decomposition in streams is difficult to predict. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. 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.

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

    Science.gov (United States)

    Riddervold, Ingunn Skogstad; Bønløkke, Jakob Hjort; Olin, Anna-Carin; Grønborg, Therese Koops; Schlünssen, Vivi; Skogstrand, Kristin; Hougaard, David; Massling, Andreas; Sigsgaard, Torben

    2012-04-30

    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/m(3), 400 μg/m(3), 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. 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. 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.

  15. 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...... of tree species and soil type on wood ash dissolution, granulated wood ash with particle size 2-4 mm was incubated in situ for 7 years in polyamide mesh bags. The bags were placed under the organic horizon of beech, oak, Norway spruce and Douglas-fir on a nutrient poor soil (typic Haplorthod......) and a nutrient-rich soil (oxyaquic Hapludalf) in Denmark. After 7 years of incubation, the weight loss of the wood ash granulates was 20% in both soil types. Nutrient losses determined by total element analysis were about 35% for calcium, magnesium and potassium and 19% for phosphorus, regardless of tree species...

  16. Adhesive Penetration of Wood and Its Effect on Bond Strength

    Science.gov (United States)

    Charles R. Frihart

    2016-01-01

    Woodworkers know that wood is porous in that adhesive flows into lumens for a mechanical interlock (1) and that wood absorbs water, allowing the use of water-borne adhesives. However, the anatomical aspects of wood that lend to its porosity are much more complicated and have a greater influence on adhesive performance than is normallyrealized or discussed. This...

  17. Effects of wood fiber surface chemistry on strength of wood-plastic composites

    Science.gov (United States)

    Migneault, Sébastien; Koubaa, Ahmed; Perré, Patrick; Riedl, Bernard

    2015-07-01

    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 conclusions were found with FTIR where WPC strength decreases as lignin peaks intensity increases. Esterification reaction of fibers with MAPE occurs on polar sites of carbohydrates, such as hydroxyls (Osbnd H). Thus, fibers with carbohydrates-rich surface, such as cellulose pulp, produced stronger WPC samples. Other factors such as mechanical interlocking and fiber morphology interfered with the effects of fiber surface chemistry.

  18. Effects of heat treatment of wood on hydroxylapatite type mineral precipitation and biomechanical properties in vitro.

    Science.gov (United States)

    Rekola, J; Lassila, L V J; Hirvonen, J; Lahdenperä, M; Grenman, R; Aho, A J; Vallittu, P K

    2010-08-01

    Wood is a natural fiber reinforced composite. It structurally resembles bone tissue to some extent. Specially heat-treated birch wood has been used as a model material for further development of synthetic fiber reinforced composites (FRC) for medical and dental use. In previous studies it has been shown, that heat treatment has a positive effect on the osteoconductivity of an implanted wood. In this study the effects of two different heat treatment temperatures (140 and 200 degrees C) on wood were studied in vitro. Untreated wood was used as a control material. Heat treatment induced biomechanical changes were studied with flexural and compressive tests on dry birch wood as well as on wood after 63 days of simulated body fluid (SBF) immersion. Dimensional changes, SBF sorption and hydroxylapatite type mineral formation were also assessed. The results showed that SBF immersion decreases the biomechanical performance of wood and that the heat treatment diminishes the effect of SBF immersion on biomechanical properties. With scanning electron microscopy and energy dispersive X-ray analysis it was shown that hydroxylapatite type mineral precipitation formed on the 200 degrees C heat-treated wood. An increased weight gain of the same material during SBF immersion supported this finding. The results of this study give more detailed insight of the biologically relevant changes that heat treatment induces in wood material. Furthermore the findings in this study are in line with previous in vivo studies.

  19. Effects of raw materials on the properties of wood fiber-polyethylene composites--part 3: effect of a compatibilizer and wood adhesive on the interfacial adhesion of wood/plastic composites

    Science.gov (United States)

    Chin-yin Hwang; Chung-yun Hse; Todd F. Shupe

    2008-01-01

    The objective of this study was to examine the effect of maleated polypropylene compatabilizer on the interfacial properties of wood and polyolefins. Birch wood dowels containing an adhesive applied on the surface were embedded in molten plastic matrices using specially designed jigs. The three plastics investigated included low density polyethylene (LFPE), linear low...

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

    Science.gov (United States)

    Ribera, Javier; Gandía, Mónica; Marcos, Jose F; Bas, Maria Del Carmen; Fink, Siegfried; Schwarze, Francis W M R

    2017-01-01

    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.

  1. 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.

  2. 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

  3. 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...

  4. 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.

  5. The effect of tannins and pH on the corrosion of metals in wood extracts

    Science.gov (United States)

    Samuel Zelinka; D.S. Stone

    2011-01-01

    Tannins and pH are often cited as factors that affect the corrosiveness of wood yet there are few data to confirm these statements. The purpose of this paper is to systematically investigate the effect of tannins and pH on corrosion of metals in wood. Four wood species known to vary in both their pH and extractives were chosen and extracted with water. The pH, tannin...

  6. Effects of a dehydrating agent on the carbonization of wood

    Science.gov (United States)

    Kim, Dae-Young; Kang, Kyu-Young

    2012-05-01

    The carbonization of sulfuric acid impregnated wood meal and wood block was studied by using thermogravimetry (TG) and scanning electron microscopy (SEM). The samples were carbonized up to 800 °C at a heating rate of 10 °C/min under nitrogen. Improvement of the char yield was observed to be similar to the case of cellulose. Without sulfuric acid impregnation, the wood blocks significantly shrank on carbonization, and the shrinkage was strongly anisotropic. The degree of shrinkage was in the order of tangential > radial > longitudinal directions. Sulfuric acid impregnated wood blocks largely retained the size and cell wall morphology. The nitrogen adsorption surface area of wood meal char prepared with sulfuric acid impregnation was greater than that of the control. Thus, the carbonization of wood with sulfuric acid impregnation was found to be advantageous in mass yield and preservation of size and shape.

  7. Effect of eucalyptus wood vinegar on rubberwood infestation by Asian subterranean termite, Coptotermes gestroi Isoptera: Rhinotermitidae).

    Science.gov (United States)

    Tarasin, M

    2013-01-01

    Wood degradation caused by fungi, termites, and insects, is a major problem for the rubberwood industry. The potential of wood vinegar as rubberwood preservative was studied. The infestation rates of Coptotermes gestroi (Wasmann) (Isoptera: Rhinotermitidae) on rubberwood samples treated with 25%, 50% and 100% eucalyptus wood vinegar for 24 hours were observed in laboratory conditions. Both non-choice and choice experiments were included. The effects of eucalyptus wood vinegar treatment depended on its concentration. In the non-choice experiments, rubberwood samples treated with 100% eucalyptus wood vinegar had the highest resistance to C. gestroi infestation, with the lowest relative loss of mass, followed in rank order by 50% and 25% treatments. However, in the choice experiments the relative loss of mass did not differ significantly between the treatments with varied wood vinegar concentration. Untreated control samples were distinctly infested by C. gestroi in both non-choice and choice experiments, but their relative loss of mass in the non-choice experiments was not significantly different from samples treated with 25% eucalyptus wood vinegar. Hence, 25% eucalyptus wood vinegar was not effective as rubberwood preservative against C. gestroi attack. The results suggest that eucalyptus wood vinegar acts as a rubberwood preservative against termites, provided the treatment is done without dilution. About 50% dilution still has some efficacy, while lower concentrations are not effective.

  8. Effects of wood on debris flow runout in small mountain watersheds.

    Science.gov (United States)

    Stephen T. Lancaster; Shannon K. Hayes

    2003-01-01

    Debris flows have typically been viewed as two-phase mixtures of sediment and water, but in forested mountain landscapes, wood can represent a sizable fraction of total flow volume. The effects of this third phase on flow behavior are poorly understood. To evaluate whether wood can have a significant effect on debris flow runout in small mountainous watersheds, we used...

  9. Effects of wood vinegar as an additive for natural rubber products

    Directory of Open Access Journals (Sweden)

    Kulchanat Prasertsit

    2011-08-01

    Full Text Available Wood vinegar, a product of wood burning in airless condition, is well known as an all- purpose natural chemical, since it can beused in agricultural, food, and pharmaceutical industries, even for home care products. Because of its acidity and anti microorganismgrowth property, it is of interest to use wood vinegar for rubber products by fully or partially replacing the usage oftraditional acids in the production processes. This work is to study effects of crude coconut shell wood vinegar on naturalrubber products. The experiment was conducted by introducing various concentrations of wood vinegar to block and sheetrubbers. Results showed that wood vinegar can improve initial plasticity, plasticity retention index and Mooney viscosity ofrubber products. Moreover, it can also retard the growth of fungi in the products.

  10. A wood density and aboveground biomass variability assessment using pre-felling inventory data in Costa Rica.

    Science.gov (United States)

    Svob, Sienna; Arroyo-Mora, J Pablo; Kalacska, Margaret

    2014-12-01

    The high spatio-temporal variability of aboveground biomass (AGB) in tropical forests is a large source of uncertainty in forest carbon stock estimation. Due to their spatial distribution and sampling intensity, pre-felling inventories are a potential source of ground level data that could help reduce this uncertainty at larger spatial scales. Further, exploring the factors known to influence tropical forest biomass, such as wood density and large tree density, will improve our knowledge of biomass distribution across tropical regions. Here, we evaluate (1) the variability of wood density and (2) the variability of AGB across five ecosystems of Costa Rica. Using forest management (pre-felling) inventories we found that, of the regions studied, Huetar Norte had the highest mean wood density of trees with a diameter at breast height (DBH) greater than or equal to 30 cm, 0.623 ± 0.182 g cm -3 (mean ± standard deviation). Although the greatest wood density was observed in Huetar Norte, the highest mean estimated AGB (EAGB) of trees with a DBH greater than or equal to 30 cm was observed in Osa peninsula (173.47 ± 60.23 Mg ha -1 ). The density of large trees explained approximately 50% of EAGB variability across the five ecosystems studied. Comparing our study's EAGB to published estimates reveals that, in the regions of Costa Rica where AGB has been previously sampled, our forest management data produced similar values. This study presents the most spatially rich analysis of ground level AGB data in Costa Rica to date. Using forest management data, we found that EAGB within and among five Costa Rican ecosystems is highly variable. Combining commercial logging inventories with ecological plots will provide a more representative ground level dataset for the calibration of the models and remotely sensed data used to EAGB at regional and national scales. Additionally, because the non-protected areas of the tropics offer the greatest opportunity to reduce

  11. 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.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... Momo AC (1972). Some thought on wood storage. Niger. J. For. 2(2):. 76-79. Odeyinde MA (1980). Wood decay organisms. Proceedings of the seminar on protection and pre-treatment of Nigerian timbers. Forestry Research Institute of Nigeria Ibadan, 30th April, 1980, pp. 17-23. Wilcox W (1983). Sensitivity ...

  13. 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...

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... largely Ascomycetes and Dueteromycetes, although some Phycomycetes may be present. When a log is abandoned in the forest for a considerable length of time, the early colonizers are replaced by wood-rotting Asco- mycetes and Basidiomycetes (Mommoh, 1972). De Groot. (1975) observed that wood ...

  15. The Effect of Fungal Decay on Ficus Sycomorus Wood

    Directory of Open Access Journals (Sweden)

    Maisa MANSOUR

    2013-09-01

    Full Text Available The deterioration of wood on account of microbiological agents is an acknowledged fact. Botryodiplodia theobromae - Trichoderma longibrachiatum - Aspergillus candidus - Aspergillus ustus and Aspergillus terreus were isolated from two wooden masks dating back to the Greek- Roman period in Egypt. The chemical composition of wood is easily affected after any attack and visible changes can be noticed clearly after some time, but the degree of deterioration of wood constituents cannot be estimated unless the wood is closely studied. Ficus sycomorus wood samples, which had been infected by the fungi isolated from the masks, were studied by using X Ray Diffraction (XRD and Fourier Transform Infrared Spectroscopy with Attenuation Total Reflection (FTIR-ATR.

  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...

  17. Effect of biomass ash in catalytic fast pyrolysis of pine wood

    NARCIS (Netherlands)

    Yildiz, G.; Ronsse, F.; Venderbosch, R.H.; van Duren, R.; Kersten, Sascha R.A.; Prins, W.

    2015-01-01

    Fast pyrolysis experiments of pine wood have been performed in a continuously operated mechanically stirred bed reactor at 500 °C. The effects of the pine wood ash were studied by comparing non-catalytic and catalytic experiments (using a ZSM-5 based catalyst) with their ash-added counterparts. To

  18. 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...

  19. 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...

  20. 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...

  1. Effect of different levels of wood ash on nutrient contents of maize ...

    African Journals Online (AJOL)

    Field experiments were conducted at Umudike in the rainforest zone and at Igbariam in the derived savanna zone in early seasons of 2001 and 2002 to study quantitatively wood ash effects on leaf nutrient compositions and grain yield. Treatments consisted of 0,2,4,6 and 8t, ha wood ash replicated thee times in a ...

  2. 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...

  3. Non Methane Hydrocarbons (NMHCs) at the centre of Athens: variability and relative contribution of traffic and wood burning

    Science.gov (United States)

    Panopoulou, Anastasia; Liakakou, Eleni; Psiloglou, Basil; Gros, Valerie; Bonsang, Bernard; Sauvage, Stephane; Locoge, Nadine; Lianou, Maria; Gerasopoulos, Evangelos; Mihalopoulos, Nikolaos

    2016-04-01

    Non-methane hydrocarbons (NMHC) can be found in significant concentrations in urban areas. They are emitted by biogenic and anthropogenic sources like vehicle exhaust, gasoline evaporation and solvent use. Once emitted they mainly react with hydroxyl radicals (OH) and in the presence of nitrogen oxides (NOx) lead to the formation of secondary pollutants such as ozone (O3), peroxy acetyl nitrate (PAN) and secondary organic aerosols. In Great Athens Area (GAA) despite the numerous air quality issues especially with exceedances in ozone and particulate matter (PM), continuous monitoring of NMHCs is absent. This work presents the first results of a ChArMEX/TRANSEMED project dealing with VOC source apportionment and emission inventory evaluation in megacities around the Mediterranean basin. A representative site in the centre of Athens is progressively equipped with high performance instruments in order to measure continuously NMHCs (time resolution of 30 min) over a long period. The main objective of this presentation is the determination of the ambient level and temporal variability of C2-C6 NMHCs, as well as the impact of the sources controlling their variability. The importance of this work is attributed to the high time resolution measurements providing a detailed light hydrocarbons profile of the area for first time in the GAA. An automatic gas chromatograph (airmoVOC C2-C6 Chromatrap GC, Chromatotec, France) equipped with a flame ionization detector (FID) has been used for the in-situ measurements of NMHCS with two to six carbon atoms (C2-C6 NMHCs) during the period from the 16 of October to end of December 2015. In addition, meteorological and auxiliary data for major gases (CO, O3, NOx) and particulates (PM and Black Carbon (BC) are also available. Atmospheric concentrations of NMHCs range from below the detection limit to a few ppbs, for example almost 14 ppb, 20 ppb and 25 ppb for ethane, propane and acetylene respectively. Between the NMHCs being monitored

  4. EFFECT OF THE SITE IN TECHNOLOGICAL CHARACTERISTICS OF EUCALYPTUS WOOD FOR KRAFT PULP PRODUCTION

    Directory of Open Access Journals (Sweden)

    Patricia Kerlly Ramalho Martins Benites

    2012-11-01

    Full Text Available The aim of this study was to analyze the technological characteristics for pulp production from three eucalyptus clones planted in two different sites derived from experiments considered clonal test from a Brazilian pulp industry. It was determined the wood basic density, the fibers morphologies and the chemical composition of clones(extractives content, lignin and carbohydrates. Kraft pulping was made, using alkali different loads in order to obtain pulps with kappa number 18± 1. The quality of site did not influence on fiber length, the surface area of vessels for all clones, in additional to the syringyl / guaiacyl for clone C. The quality of site influenced on the wood density, wall thickness, extractives content, lignin and syringyl / guaiacyl ratio (except for clone C and carbohydrates. The cloneB showed the better performance on pulp production and an intermediate effect of site at technological characteristics, when comparing with Clones A and C. The Clone C showed the least effect of site on performance of pulp production and it was the only clone that showedno site effect in relation to syringyl/guaiacyl, indicating that this variable is an important parameter for pulp production regarding on performance and alkali loads.

  5. Effect of adding biochar with wood vinegar on the growth of cucumber

    Science.gov (United States)

    Pan, Xin; Zhang, Yipeng; Wang, Xiao; Liu, Guocheng

    2017-04-01

    The chemical fertilizers are abused to improve crop yields, which cause lots of soil problems (e.g., soil compaction and native nutrient loss). We thus investigated the potential of the combination of biochar and wood vinegar as a new type of fertilizer to replace the traditional fertilizer. The results in this study showed that the combined addition of biochar with wood vinegar had the greatest promotion effect on the plant growth of cucumber. Compared to the control treatment, the biochar addition with wood vinegar significantly increased the plant height, root length, root volume and root tips by 29.7%, 117%, 121% and 76.1%, respectively. These positive effects could be attributed to the benefits of the addition of biochar with wood vinegar treatment on improving soil fertility, increasing nutrient supply, and further stimulating plant growth. Overall, the combination of biochar and wood vinegar could be a promising fertilizer to promote plants growth and enhance crop yields.

  6. 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.

  7. The effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood

    National Research Council Canada - National Science Library

    Korkut, Derya Sevim; Korkut, Süleyman; Bekar, Ilter; Budakçi, Mehmet; Dilik, Tuncer; Cakicier, Nevzat

    2008-01-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L.) wood were examined...

  8. Microbial communities in large-scale wood piles and their effects on wood quality and the environment.

    Science.gov (United States)

    Noll, Matthias; Jirjis, Raida

    2012-08-01

    The demand of renewable energy sources, i.e. biomass, is steadily increasing worldwide to reduce the need of fossil energy sources. Biomass such as energy crops, woody species, forestry and agricultural residues are the most common renewable energy sources. Due to uneven demand for wood fuel, the material is mostly stored outdoors in chip piles or as logs until utilisation. Storage of biomass is accompanied by chemical, physical and biological processes which can significantly reduce the fuel quality. However, heating plants require high-quality biomass to ensure efficient operation, thereby minimising maintenance costs. Therefore, optimised storage conditions and duration times for chipped wood and tree logs have to be found. This paper aims at reviewing available knowledge on the pathways of microbial effects on stored woody biomass and on investigations of the fungal and bacterial community structure and identity. Moreover, potential functions of microorganisms present in wood chip piles and logs are discussed in terms of (1) reduction of fuel quality, (2) catalysing self-ignition processes, and (3) constituting health risk and unfriendly work environment.

  9. 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; ...

  10. 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.

  11. Soil organic matter dynamics under decaying wood in a subtropical wet forest: effect of tree species and decay stage.

    Science.gov (United States)

    Marcela Zalamea; Grizelle Gonzalez; Chien-Lu Ping; Gary Michaelson

    2007-01-01

    Decaying wood is an important structural and functional component of forests: it contributes to generate habitat diversity, acts as either sink or source of nutrients, and plays a preponderant role in soil formation. Thus, decaying wood might likely have measurable effects on chemical properties of the underlying soil.We hypothesized that decaying wood would have a...

  12. Effects of nano-clay on biological resistance of wood-plastic composite against five wood-deteriorating fungi

    OpenAIRE

    Bari,E; Taghiyari,H. R; Schmidt, O.; A Ghorbani; Aghababaei, H.

    2015-01-01

    Effects of nano-clay on weight loss of wood-plastic composites (WPC) by five fungi were studied. Nanoclay particles of 20 to 50 nm size were applied at 2, 4, and 6% WPC of 0,90 g/cm³ density. The white-rot fungi Physisporinus vitreus, Pleurotus ostreatus and Trametes versicolor as well as the brown-rot species Antrodia vaillantii and Coniophora puteana were used. Mass loss tests were conducted according to the European standard. The highest (3,2%) and lowest (0,2%) mass losses were produced b...

  13. Wood combustion particles induce adverse effects to normal and diseased airway epithelia.

    Science.gov (United States)

    Krapf, Manuel; Künzi, Lisa; Allenbach, Sandrine; Bruns, Emily A; Gavarini, Ilaria; El-Haddad, Imad; Slowik, Jay G; Prévôt, André S H; Drinovec, Luka; Močnik, Griša; Dümbgen, Lutz; Salathe, Matthias; Baumlin, Nathalie; Sioutas, Constantinos; Baltensperger, Urs; Dommen, Josef; Geiser, Marianne

    2017-04-19

    Residential wood burning is a major source of poorly characterized, deleterious particulate matter, whose composition and toxicity may vary with wood type, burning condition and photochemical age. The causative link between ambient wood particle constituents and observed adverse health effects is currently lacking. Here we investigate the relationship between chemical properties of primary and atmospherically aged wood combustion particles and acute toxicity in human airway epithelial cells. Emissions from a log wood burner were diluted and injected into a smog chamber for photochemical aging. After concentration-enrichment and removal of oxidizing gases, directly emitted and atmospherically aged particles were deposited on cell cultures at the air-liquid interface for 2 hours in an aerosol deposition chamber mimicking physiological conditions in lungs. Cell models were fully differentiated normal and diseased (cystic fibrosis and asthma) human bronchial epithelia (HBE) and the bronchial epithelial cell line BEAS-2B. Cell responses were assessed at 24 hours after aerosol exposure. Atmospherically relevant doses of wood combustion particles significantly increased cell death in all but the asthma cell model. Expression of oxidative stress markers increased in HBE from all donors. Increased cell death and inflammatory responses could not be assigned to a single chemical fraction of the particles. Exposure to primary and aged wood combustion particles caused adverse effects to airway epithelia, apparently induced by several interacting components.

  14. Effect of UV exposure on the surface chemistry of wood veneers treated with ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Patachia, Silvia, E-mail: st.patachia@unitbv.ro [' Transilvania' University of Brasov, Chemistry Department, Eroilor 29 Str., 500036, Brasov (Romania); Croitoru, Catalin, E-mail: c.croitoru@unitbv.ro [' Transilvania' University of Brasov, Chemistry Department, Eroilor 29 Str., 500036, Brasov (Romania); Friedrich, Christian [Albert-Ludwigs-Universitaet Freiburg, Stefan-Meier-Str. 28, Freiburg (Germany)

    2012-07-01

    In this paper, the influence of four types of imidazolium-based ionic liquids (ILs) on the chemical alteration of the surface of wood veneers exposed to 254 nm UV irradiation have been studied by using image analysis, Fourier transform infrared spectroscopy and surface energy calculation. The wood treated with ionic liquids showed better stability to UV light, as demonstrated by the low lignin, carbonyl index and cellulose crystallinity index variation, as well as very small color modification of the surface with the increase of the UV exposure period, by comparing to non-treated wood. The results show that the tested ionic liquids could be effective as UV stabilizers.

  15. Transformations of Nanoenabled Copper Formulations Govern Release, Antifungal Effectiveness, and Sustainability throughout the Wood Protection Lifecycle.

    Science.gov (United States)

    Pantano, Daniele; Neubauer, Nicole; Navratilova, Jana; Scifo, Lorette; Civardi, Chiara; Stone, Vicki; von der Kammer, Frank; Müller, Philipp; Sobrido, Marcos Sanles; Angeletti, Bernard; Rose, Jerome; Wohlleben, Wendel

    2018-02-06

    Here we compare the standard European benchmark of wood treatment by molecularly dissolved copper amine (Cu-amine), also referred to as aqueous copper amine (ACA), against two nanoenabled formulations: copper(II)oxide nanoparticles (CuO NPs) in an acrylic paint to concentrate Cu as a barrier on the wood surface, and a suspension of micronized basic copper carbonate (CuCO 3 ·Cu(OH) 2 ) for wood pressure treatment. After characterizing the properties of the (nano)materials and their formulations, we assessed their effects in vitro against three fungal species: Coniophora puteana, Gloeophyllum trabeum, and Trametes versicolor, finding them to be mediated only partially by ionic transformation. To assess the use phase, we quantify both release rate and form. Cu leaching rates for the two types of impregnated wood (conventional and nanoenabled) are not significantly different at 172 ± 6 mg/m 2 , with Cu being released predominantly in ionic form. Various simulations of outdoor aging with release sampling by runoff, during condensation, by different levels of mechanical shear, all resulted in comparable form and rate of release from the nanoenabled or the molecular impregnated woods. Because of dissolving transformations, the nanoenabled impregnation does not introduce additional concern over and above that associated with the traditional impregnation. In contrast, Cu released from wood coated with the CuO acrylate contained particles, but the rate was at least 100-fold lower. In the same ranking, the effectiveness to protect against the wood-decaying basidiomycete Coniophora puteana was significant with both impregnation technologies but remained insignificant for untreated wood and wood coated by the acrylic CuO. Accordingly, a lifecycle-based sustainability analysis indicates that the CuO acrylic coating is less sustainable than the technological alternatives, and should not be developed into a commercial product.

  16. 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...

  17. 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)

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Rashmi R Devi

    2013-01-01

    Full Text Available 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 repellancy, dimensional stability, hardness, flexural, tensile and thermal stability compared to untreated wood.

  20. Modeling the CO2-effects of forest management and wood usage on a regional basis.

    Science.gov (United States)

    Knauf, Marcus; Köhl, Michael; Mues, Volker; Olschofsky, Konstantin; Frühwald, Arno

    2015-12-01

    At the 15th Conference of Parties of the UN Framework Convention on Climate Change, Copenhagen, 2009, harvested wood products were identified as an additional carbon pool. This modification eliminates inconsistencies in greenhouse gas reporting by recognizing the role of the forest and timber sector in the global carbon cycle. Any additional CO2-effects related to wood usage are not considered by this modification. This results in a downward bias when the contribution of the forest and timber sector to climate change mitigation is assessed. The following article analyses the overall contribution to climate protection made by the forest management and wood utilization through CO2-emissions reduction using an example from the German state of North Rhine-Westphalia. Based on long term study periods (2011 to 2050 and 2100, respectively). Various alternative scenarios for forest management and wood usage are presented. In the mid- to long-term (2050 and 2100, respectively) the net climate protection function of scenarios with varying levels of wood usage is higher than in scenarios without any wood usage. This is not observed for all scenarios on short and mid term evaluations. The advantages of wood usage are evident although the simulations resulted in high values for forest storage in the C pools. Even the carbon sink effect due to temporal accumulation of deadwood during the period from 2011 to 2100 is outbalanced by the potential of wood usage effects. A full assessment of the CO2-effects of the forest management requires an assessment of the forest supplemented with an assessment of the effects of wood usage. CO2-emission reductions through both fuel and material substitution as well as CO2 sink in wood products need to be considered. An integrated assessment of the climate protection function based on the analysis of the study's scenarios provides decision parameters for a strategic approach to climate protection with regard to forest management and wood use at

  1. Effect of Moisture Sorption State on Vibrational Properties of Wood

    Science.gov (United States)

    Jianxiong Lu; Jiali Jiang; Yiqiang Wu; Xianjun Li; Zhiyong Cai

    2012-01-01

    The purpose of this study was to investigate the vibrational properties and corresponding anisotropicity in wood during different states of moisture sorption. Samples of maple (Acer spp.) and red oak (Quercus rubra Michx.f.) were moisture conditioned by the adsorption process from an ovendried state and by the desorption process...

  2. The effect of aspen wood characteristics and properties on utilization

    Science.gov (United States)

    Kurt H. Mackes; Dennis L. Lynch

    2001-01-01

    This paper reviews characteristics and properties of aspen wood, including anatomical structure and characteristics, moisture and shrinkage properties, weight and specific gravity, mechanical properties, and processing characteristics. Uses of aspen are evaluated: sawn and veneer products, composite panels, pulp, excelsior, post and poles, animal bedding, animal food...

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

    DEFF Research Database (Denmark)

    Lange, Jette Bornholdt

    and job/trade codes from the National Pension Fund and self reported job titles in the Central Personal Register. Among the cases wood dust exposure occurred in 21 percent of our patients and was 7 times more frequent in patients with adenocarcinomas than in squamous cell carcinoma (p

  4. 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

  5. Historical range of variability in live and dead wood biomass: a regional-scale simulation study

    Science.gov (United States)

    Etsuko Nonaka; Thomas A. Spies; Michael C. Wimberly; Janet L. Ohmann

    2007-01-01

    The historical range of variability (HRV) in landscape structure and composition created by natural disturbance can serve as a general guide for evaluating ecological conditions of managed landscapes. HRV approaches to evaluating landscapes have been based on age classes or developmental stages, which may obscure variation in live and dead stand structure. Developing...

  6. Effects of Age and Sampling Position on Wood Property Variations ...

    African Journals Online (AJOL)

    Axial uniformity in strength properties ranged between 0.50 and 0.64, 0.65 and 0.73, and from 0.49 to 0.82 in MOR, MOE and MCS respectively. Radial uniformity index also ranged between 0.69 and 0.78 in MOR, 0.78 and 0.85 in MOE and between 0.76 and 0.80 in MCS. For all the properties studied, wood uniformity was ...

  7. 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.

  8. Experimental study of wood shaving addition in mortar and statistical modeling on selected effects

    Science.gov (United States)

    Sotiropoulou, Anastasia; Gavela, Stamatia; Nikoloutsopoulos, Nikolaos; Passa, Dimitra; Papadakos, Georgios

    2017-04-01

    In the frame of an extended research program dealing with wood shavings utilization in mortar, a set of procedures were developed for verifying effects of wood shavings addition to specific mortar properties. Mixes containing wood shavings replacing fine aggregates by 0, 30, 50 and 70% of their volume were made. Workability, fresh mortar unit weight, ultrasonic pulse velocity (UPV) and flexural and compressive strength were determined, based on measurements, at various curing ages. Measurement results and analysis suggest that compressive strength reduction caused by wood shavings addition could be predicted. The outcome was standardized in the form of a multifactorial sigmoidal model. It was also made evident that the mix proportion of cement increases when wood shavings are used as a by volume replacement of conventional fine aggregates, due to the low value of specific gravity of wood compared to conventional aggregates. Another procedure is suggested based on mass and volume measurements aiming at the verification of the mix proportions in the final mortar mixture.

  9. Phenolic composition of vinegars over an accelerated aging process using different wood species (acacia, cherry, chestnut, and oak): effect of wood toasting.

    Science.gov (United States)

    Cerezo, Ana B; Álvarez-Fernández, M Antonia; Hornedo-Ortega, Ruth; Troncoso, Ana M; García-Parrilla, M Carmen

    2014-05-14

    Wood shavings are widely employed in vinegar making to reduce aging time. Accordingly, this study aims to evaluate the effects of using shavings from different wood species (acacia, cherry, chestnut, and oak) and of toasting on the release of phenolic compounds into vinegar during the aging process. The study involved aging vinegars using previously toasted shavings and untoasted ones, at 0.5% and 1% (w/v), and collecting samples at 15 and 30 days. The phenolic compounds were analyzed by LC-DAD during the aging process. As a result, wood markers naringenin and kaempferol (cherry), robinetin and fustin (acacia), and isovanillin (oak) were identified for the first time in vinegars. The results also showed that toasting wood shavings decreases the concentration of most flavonoid wood markers (e.g., (+)-taxifolin, naringenin, and fustin) in vinegar, but that it is essential for the highest releases of aldehyde compounds (syringaldehyde, protocatechualdehyde, and vanillin). Remarkably, 15 days was sufficient to obtain the highest increases of most polyphenol compounds in the vinegar. Statistical analysis (linear discriminant analysis) proved that the phenolic compounds identified in vinegars are useful for discriminating vinegars regarding the wood species of the shavings used to accelerate aging.

  10. The effect of density and thermal diffusivity of wood on the rate of burning of wood cribs

    Science.gov (United States)

    H.D. Bruce; W.Y. Pong; W.L. Fons

    1961-01-01

    A program of research on free-burning wood fires is being conducted by the Forest Service to build up experimental data on the properties of such fires, with the iltimate objective of describing the physical phenomena in terms of fundamental laws. Density was the first wood property investigated. This report gives data on the rate of burning of cribs of five species...

  11. 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.

  12. The variability of pulp-wood basic specific gravity of softwood

    Directory of Open Access Journals (Sweden)

    Jiří Holan

    2004-01-01

    Full Text Available In the present study, basic density of pulpwood of Norway spruce (Piceas abies /L./ Karst. and Scots pine (Pinus sylvestris L. was investigated. The variability of basic density and factors applied are out of concern. Factors are characterised by localization along the log, growing conditions defined by geographic area of Czech Republic, diameter of log, and the storing of logs within transport loading. Basic density was determined on cores taken by modified Pressler borer in the radial direction from bark to pith. The average basic density of Norway spruce is comparable to Scots pine, as well as the variation coefficient. Basic density of Norway spruce was found 443 kg.m-3 (Vx = 13.9% where as the Scots pine base density was 450 kg.m-3 (Vx = 15.5%. Basic density was significantly influenced by all factors assessed except the localization of cores along logs. The investigation demonstrated that basic density can be affected by locality of supply in comparison to within logs variability that have much lower importance.

  13. Pinus taeda L. wood property calibrations based on variable numbers of near infrared spectra per core and cores per plantation

    Science.gov (United States)

    Laurence R. Schimleck; Justin A. Tyson; David Jones; Gary F. Peter; Richard F. Daniels; Alexander III Clark

    2007-01-01

    Near infrared (NIR) spectroscopy provides a rapid, non-destructive method for the estimation of several wood properties of increment cores. MR spectra are collected from adjacent sections of the same core; however, not all spectra are required for calibration purposes as spectra from the same core are autocorrelated. Previously, we showed that wood property...

  14. IMPREGNATION OF WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Engin Derya Gezer

    2003-04-01

    Full Text Available The production of wood based structural panel and lumber composites become to increase since the wood supply is changing due to the limit of larger dimension solid sawn lumber and insufficient solid woods with enough high strength as well. As we substitute wood composites for solid wood in protected application, these composite must show resistance to wood-destroying organisms such as fungi and insects. Accordingly, the exterior structural composites is required to be treated with preservatives. This paper provides an understanding of preservative treated wood composites. The objectives of this paper includes studying how to add preservative to wood composites, examining additive effect on glue-line and evaluating the best method of manufacturing wood composites treated with preservatives.

  15. 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.

  16. The effect of exposure to wood smoke on outcomes of childhood pneumonia in Botswana.

    Science.gov (United States)

    Kelly, M S; Wirth, K E; Madrigano, J; Feemster, K A; Cunningham, C K; Arscott-Mills, T; Boiditswe, S; Shah, S S; Finalle, R; Steenhoff, A P

    2015-03-01

    Tertiary hospital in Gaborone, Botswana. To examine whether exposure to wood smoke worsens outcomes of childhood pneumonia. Prospective cohort study of children aged 1-23 months meeting clinical criteria for pneumonia. Household use of wood as a cooking fuel was assessed during a face-to-face questionnaire with care givers. We estimated crude and adjusted risk ratios (RRs) and 95% confidence intervals (CIs) for treatment failure at 48 h by household use of wood as a cooking fuel. We assessed for effect modification by age (1-5 vs. 6-23 months) and malnutrition (none vs. moderate vs. severe). The median age of the 284 enrolled children was 5.9 months; 17% had moderate or severe malnutrition. Ninety-nine (35%) children failed treatment at 48 h and 17 (6%) died. In multivariable analyses, household use of wood as a cooking fuel increased the risk of treatment failure at 48 h (RR 1.44, 95%CI 1.09-1.92, P = 0.01). This association differed by child nutritional status (P = 0.02), with a detrimental effect observed only among children with no or moderate malnutrition. Exposure to wood smoke worsens outcomes for childhood pneumonia. Efforts to prevent exposure to smoke from unprocessed fuels may improve pneumonia outcomes among children.

  17. 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.

  18. Effect of controlling herbaceous and woody competing vegetation on wood quality of planted loblolly pine

    Science.gov (United States)

    Alexander Clark; Richard F. Daniels; James H. Miller

    2006-01-01

    Southern pine plantations are increasingly established using herbicides to control herbaceous and/or woody competing vegetation to enhance growth, but little is known about the effect on wood quality. A study was established at 13 southern locations in 1984 to examine the effects of complete control of woody, herbaceous, and woody plus herbaceous competition for the...

  19. Effect of thermal treatments on technological properties of wood from two Eucalyptus species.

    Science.gov (United States)

    Cademartori, Pedro Henrique G; Missio, André L; Mattos, Bruno D; Gatto, Darci A

    2015-03-01

    The effect of thermal treatments on physical and mechanical properties of rose gum and Sydney blue gum wood was evaluated. Wood samples were thermally modified in a combination: pre-treatment in an autoclave (127°C - 1h) and treatment in an oven (180-240°C - 4h); and only treatment in an oven at 180-240°C for 4h. Chemical changes in the structure of woods were evaluated through infrared spectroscopy. Evaluation of physical properties was performed through mass loss, specific gravity, equilibrium moisture content and dimensional stability tests. Surface changes were analyzed through apparent contact angle technique and static bending tests were carried out to evaluate the mechanical behavior. Use of pre-treatment in autoclave affected the properties analyzed, however oven, resulted in the highest changes on wood from both species. Chemical changes were related to the degradation of hemicelluloses. Moreover, a significant decrease of hygroscopicity and mechanical strength of thermally modified woods was observed, while specific gravity did not significantly change for either of the species studied. The best results of decrease of wettability were found in low temperatures, while dimensional stability increased as a function of temperature of exposure in oven. The highest loss of mechanical strength was observed at 240°C for both species.

  20. 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

  1. 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.

  2. Effect of a fire retardant on the ignition of pine wood exposed to smoldering particles of pine bark

    Science.gov (United States)

    Kasymov, Denis; Paletsky, Alexander

    2017-10-01

    This paper represents the laboratory research results on the interaction of smoldering pine bark particles with pine wood. Fire retardant treatment "FUKAM" was studied to estimate its effect on the probability of wood ignition. The wind speed and the number and geometric sizes of particles were varied in the experiments. The results have shown that the increase in the wind speed leads to the increase in the probability of wood ignition by the particles of the same size, and fire-retardant treatment significantly increases the protective properties of wood exposed to smoldering pine bark particles.

  3. Effect of a fire retardant on the ignition of pine wood exposed to smoldering particles of pine bark

    Directory of Open Access Journals (Sweden)

    Kasymov Denis

    2017-01-01

    Full Text Available This paper represents the laboratory research results on the interaction of smoldering pine bark particles with pine wood. Fire retardant treatment "FUKAM" was studied to estimate its effect on the probability of wood ignition. The wind speed and the number and geometric sizes of particles were varied in the experiments. The results have shown that the increase in the wind speed leads to the increase in the probability of wood ignition by the particles of the same size, and fire-retardant treatment significantly increases the protective properties of wood exposed to smoldering pine bark particles.

  4. Effect of Moringa oleifera Lam. root-wood on ethylene glycol induced urolithiasis in rats.

    Science.gov (United States)

    Karadi, Ravindra V; Gadge, Navneet B; Alagawadi, K R; Savadi, Rudraprabhu V

    2006-04-21

    In India, drumstick (Moringa oleifera Lam. (Moringaceae)) is commonly used as a phytotherapeutic agent. The effect of oral administration of aqueous and alcoholic extract of Moringa oleifera root-wood on calcium oxalate urolithiasis has been studied in male Wistar albino rats. Ethylene glycol feeding resulted in hyperoxaluria as well as increased renal excretion of calcium and phosphate. Supplementation with aqueous and alcoholic extract of Moringa oleifera root-wood significantly reduced the elevated urinary oxalate, showing a regulatory action on endogenous oxalate synthesis. The increased deposition of stone forming constituents in the kidneys of calculogenic rats was also significantly lowered by curative and preventive treatment using aqueous and alcoholic extracts. The results indicate that the root-wood of Moringa oleifera is endowed with antiurolithiatic activity.

  5. The effect of air temperature on the sappan wood extract drying

    Science.gov (United States)

    Djaeni, M.; Triyastuti, M. S.; Asiah, N.; Annisa, A. N.; Novita, D. A.

    2015-12-01

    The sappan wood extract contain natural colour called brazilin that can be used as a food colouring and antioxidant. The product is commonly found as a dry extract powder for consummer convenience. The spray dryer with air dehumidification can be an option to retain the colour and antioxidant agent. This paper discusses the effect of air temperature on sappan wood extract drying that was mixed with maltodextrin. As responses, the particle size, final moisture content, and extract solubility degradation were observed. In all cases, the process conducted in temperature ranging 90 - 110°C can retain the brazilin quality as seen in solubility and particle size. In addition, the sappan wood extract can be fully dried with moisture content below 2%. Moreover, with the increase of air temperature, the particle size of dry extract can be smaller.

  6. 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.

  7. HCl emission during co-pyrolysis of demolition wood with a small amount of PVC film and the effect of wood constituents on HCl emission reduction

    Energy Technology Data Exchange (ETDEWEB)

    Hidetoshi Kuramochi; Daisuke Nakajima; Sumio Goto; Kazutoshi Sugita; Wei Wu; Katsuya Kawamoto [National Institute for Environmental Studies, Ibaraki (Japan). Research Center for Material Cycles and Waste Management

    2008-10-15

    In this study, HCl emission during the co-pyrolysis of demolition wood and a small amount of polyvinyl chloride (PVC) film (the Cl content of which ranged from 0.5% to 6% by weight) in an N{sub 2} atmosphere at elevated temperatures of up to 600{sup o}C was measured using a laboratory-scale cylindrical batch reactor. In the pyrolysis experiments, HCl emission was reduced by the presence of wood. The effect of the primary constituents of wood (cellulose, hemicellulose, and lignin) on HCl emission was investigated by not only measuring HCl emission and Cl distribution to various phases during the co-pyrolysis of each constituent with PVC film but also by conducting thermogravimetric analysis of the constituents. This investigation first revealed that hemicellulose significantly reduced HCl emission by fixing most of the Cl molecules in a sample into pyrolyzed residue. 11 refs., 2 figs., 1 tab.

  8. 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

  9. Effects of sterilization on the energy-dissipating properties of balsa wood

    Science.gov (United States)

    Sorkin, A. B.

    1969-01-01

    Technical report on the effects of sterilization on the energy-dissipating properties of balsa wood is given. Sterilization by ethylene oxide plus heat enhances the average specific energy of balsa while plastic impregnation followed by irradiation-induced polymerization does not.

  10. Effects of Land Configuration and Wood-shavings Mulch on Pore ...

    African Journals Online (AJOL)

    Effects of Land Configuration and Wood-shavings Mulch on Pore Size Distribution and Water Retention Properties of an Ustipsamment in Northeast Nigeria. ... On the other hand, the proportion of total pore space comprised by macro pore space (diameter >36µm) was little affected by tillage and residue management at all ...

  11. Effect of wood grain and veneer side on loblolly pine veneer wettability

    Science.gov (United States)

    Todd E. Shupe; Chung Y. Hse; Elvin T. Choong; Leslie H. Groom

    1998-01-01

    Research was initiated to determine the effect of veneer side (tight or loose), and wood grain (earlywood or latewood) on the wettability of loblolly pine veneer. Contact angle measurements were performed with phenol-formaldehyde resin and distilled water. The resin and distilled water showed slightly higher contact angle mean values on the latewood portion for both...

  12. Disturbance and diversity of wood-inhabiting fungi: effects of canopy gaps and downed woody debris

    Science.gov (United States)

    Nicholas J. Brazee; Daniel L. Lindner; Anthony W. D' Amato; Shawn Fraver; Jodi A. Forrester; David J. Mladenoff

    2014-01-01

    Experimental canopy gap formation and additions of coarse woody debris (CWD) are techniques intended to mimic the disturbance regime and accelerate the development of northern hardwood forests. The effects of these techniques on biodiversity and ecosystem functioning were investigated by surveying the abundance and diversity of wood-inhabiting fungi in six treatments...

  13. 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...

  14. 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)...

  15. Effect of Six Site-Preperation Treatments on Piedmont Loblolly Pine Wood Properties at Age 15

    Science.gov (United States)

    Alexander Clark; M. Boyd Edwards

    1999-01-01

    The impact of weed control and fertilization on increased tree growth is positive and significant but the effects on wood properties are not well known. Incrernent cores were collectd from loblolly pine (pinus taeda L.) trees growing on an existing site-preparation experiment in the lower Piedmont of Georgia at age 15. The levels of site...

  16. The effect of artificially induced drought on radial increment and wood properties of Norway spruce.

    Science.gov (United States)

    Jyske, Tuula; Hölttä, Teemu; Mäkinen, Harri; Nöjd, Pekka; Lumme, Ilari; Spiecker, Heinrich

    2010-01-01

    We studied experimentally the effects of water availability on height and radial increment as well as wood density and tracheid properties of Norway spruce (Picea abies (L.) Karst.). The study was carried out in two long-term N-fertilization experiments in Southern Finland (Heinola and Sahalahti). At each site, one fertilized and one control plot was covered with an under-canopy roof preventing rainwater from reaching the soil. Two uncovered plots were monitored at each site. The drought treatment was initiated in the beginning of growing season and lasted for 60-75 days each year. The treatment was repeated for four to five consecutive years depending on the site. Altogether, 40 sample trees were harvested and discs sampled at breast height. From the discs, ring width and wood density were measured by X-ray densitometry. Tracheid properties were analysed by reflected-light microscopy and image analysis. Reduced soil water potential during the growing season decreased annual radial and height increment and had a small influence on tracheid properties and wood density. No statistically significant differences were found in the average tracheid diameter between the drought-treated and control trees. The average cell wall thickness was somewhat higher (7-10%) for the drought treatment than for the control, but the difference was statistically significant only in Sahalahti. An increased cell wall thickness was found in both early- and latewood tracheids, but the increase was much greater in latewood. In drought-treated trees, cell wall proportion within an annual ring increased, consequently increasing wood density. No interaction between the N fertilization and drought treatment was found in wood density. After the termination of the drought treatment, trees rapidly recovered from the drought stress. According to our results, severe drought due to the predicted climate change may reduce Norway spruce growth but is unlikely to result in large changes in wood properties.

  17. 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...

  18. Potential Effects of the Fuelwood Market on Wood-using Industries in Northern New England and New York

    Science.gov (United States)

    Susan B. Remington; Paul E. Sendak; Paul E. Sendak

    1984-01-01

    The increased use of fuelwood in northern New England and New York has raised concern about future supplies of manufactured wood products. Direct effects were measured by estimating the competitive advantages of the kraft pulp, waferboard, and oriented strand board industries in purchasing wood. lncreased stumpage prices in the region would have the greatest impact on...

  19. 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 eucalypt species [Eucalyptus nitens, E. grandis, and E. dunnii (of different site qualities)] wood and generated pulp was performed. This study aimed at determining the effects of wood storage at -20°C (for 6 months), by examining their chemical composition...

  20. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA TREATED WOOD; FINAL REPORT

    Science.gov (United States)

    EPA conducted a study to evaluate the effect of coatings on dislodgeable arsenic, chromium, and copper residues on the surfaces of chromated copper arsenate (CAA) treated wood. Dislodgeable CCA, determined by wipe sampling the wood surfaces, was the primary evaluation criterion f...

  1. How chip size impacts steam pretreatment effectiveness for biological conversion of poplar wood into fermentable sugars.

    Science.gov (United States)

    DeMartini, Jaclyn D; Foston, Marcus; Meng, Xianzhi; Jung, Seokwon; Kumar, Rajeev; Ragauskas, Arthur J; Wyman, Charles E

    2015-01-01

    Woody biomass is highly recalcitrant to enzymatic sugar release and often requires significant size reduction and severe pretreatments to achieve economically viable sugar yields in biological production of sustainable fuels and chemicals. However, because mechanical size reduction of woody biomass can consume significant amounts of energy, it is desirable to minimize size reduction and instead pretreat larger wood chips prior to biological conversion. To date, however, most laboratory research has been performed on materials that are significantly smaller than applicable in a commercial setting. As a result, there is a limited understanding of the effects that larger biomass particle size has on the effectiveness of steam explosion pretreatment and subsequent enzymatic hydrolysis of wood chips. To address these concerns, novel downscaled analysis and high throughput pretreatment and hydrolysis (HTPH) were applied to examine whether differences exist in the composition and digestibility within a single pretreated wood chip due to heterogeneous pretreatment across its thickness. Heat transfer modeling, Simons' stain testing, magnetic resonance imaging (MRI), and scanning electron microscopy (SEM) were applied to probe the effects of pretreatment within and between pretreated wood samples to shed light on potential causes of variation, pointing to enzyme accessibility (i.e., pore size) distribution being a key factor dictating enzyme digestibility in these samples. Application of these techniques demonstrated that the effectiveness of pretreatment of Populus tremuloides can vary substantially over the chip thickness at short pretreatment times, resulting in spatial digestibility effects and overall lower sugar yields in subsequent enzymatic hydrolysis. These results indicate that rapid decompression pretreatments (e.g., steam explosion) that specifically alter accessibility at lower temperature conditions are well suited for larger wood chips due to the non

  2. 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.

  3. 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.

  4. Some exploratory considerations of scale effects on the potential performance of wood energy conversion systems

    Science.gov (United States)

    Eggers, A. J., Jr.; Smith, B. A.; Tombaugh, L. W.

    1982-06-01

    Scale effects on the potential performance of wood energy conversion systems whose products might compete in many of the same diverse and dispersed markets as comparable products from fossil fuels are explored. The analytical approach is derived from the average total cost formulation of micro-economics which is configured to account for the factors of total cost rate for wood production, transportation, and conversion in systems with a given conversion efficiency and capacity. The exploratory systems analysis includes: systems elements and cost formulation; area production and associated transportation; point production and associated transportation; conversion system capacity effects; conversion plant learning curve effects; subsystem disaggregation, staging, and production rate effects, and conversion plant financing effects.

  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.

  6. Patterns and determinants of wood physical and mechanical properties across major tree species in China.

    Science.gov (United States)

    Zhu, JiangLing; Shi, Yue; Fang, LeQi; Liu, XingE; Ji, ChengJun

    2015-06-01

    The physical and mechanical properties of wood affect the growth and development of trees, and also act as the main criteria when determining wood usage. Our understanding on patterns and controls of wood physical and mechanical properties could provide benefits for forestry management and bases for wood application and forest tree breeding. However, current studies on wood properties mainly focus on wood density and ignore other wood physical properties. In this study, we established a comprehensive database of wood physical properties across major tree species in China. Based on this database, we explored spatial patterns and driving factors of wood properties across major tree species in China. Our results showed that (i) compared with wood density, air-dried density, tangential shrinkage coefficient and resilience provide more accuracy and higher explanation power when used as the evaluation index of wood physical properties. (ii) Among life form, climatic and edaphic variables, life form is the dominant factor shaping spatial patterns of wood physical properties, climatic factors the next, and edaphic factors have the least effects, suggesting that the effects of climatic factors on spatial variations of wood properties are indirectly induced by their effects on species distribution.

  7. 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 87Sr/86Sr (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 87Sr/86Sr 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 87Sr/86Sr, not precluding the use of this parameter for wine traceability purposes.

  8. 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.

  9. Study on the Effect of Combined Nanosilver- Hygrothermal Treatments on Wood Properties

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    Ghonche Rassam

    2014-05-01

    Full Text Available In this research, the combined effect of impregnation of wood with nanosilver solution and hygrothermal treatment on some physical and mechanical properties of beech (Fagus orientalis Lipskey and spruce (Piceaabies woods was studied. Wood specimens, Initially, were impregnated in an impregnation cylinder for 20 minutes at the pressure of 0.25 MPa, with nanosilver solution. Then, hygrothermal treatment was carried out at the temperatures of 120, 150 and 180°C for 1, 3 and 5 hours. Control specimens, without any impregnation process, were hygrothermally treated. Volumetric Swelling after 2 and 24 hours soaking in water, bending strength, impact load resistance and compressive strength parallel to the grain of specimens were measured, according to ASTM D143 and all data were analyzed statistically. The results showed that swelling and mechanical properties were decreased by increasing the temperature and duration of hygrothermal treatment. Also, nanosilver impregnated specimens which were treated at 180 ˚C had lower swelling without Not clear and not seems. Consequently or it can be concluded that with nanosilver impregnation process of wood, hygrothermal treatment would be carried out at higher temperature (180 ˚C to obtain better dimensional stability with no more decrease in mechanical properties.

  10. Expression of a fungal glucuronoyl esterase in Populus: effects on wood properties and saccharification efficiency.

    Science.gov (United States)

    Latha Gandla, Madhavi; Derba-Maceluch, Marta; Liu, Xiaokun; Gerber, Lorenz; Master, Emma R; Mellerowicz, Ewa J; Jönsson, Leif J

    2015-04-01

    The secondary walls of angiosperms contain large amounts of glucuronoxylan that is thought to be covalently linked to lignin via ester bonds between 4-O-methyl-α-D-glucuronic acid (4-O-Me-GlcA) moieties in glucuronoxylan and alcohol groups in lignin. This linkage is proposed to be hydrolysed by glucuronoyl esterases (GCEs) secreted by wood-degrading fungi. We report effects of overexpression of a GCE from the white-rot basidiomycete Phanerochaete carnosa, PcGCE, in hybrid aspen (Populus tremula L. x tremuloides Michx.) on the wood composition and the saccharification efficiency. The recombinant enzyme, which was targeted to the plant cell wall using the signal peptide from hybrid aspen cellulase PttCel9B3, was constitutively expressed resulting in the appearance of GCE activity in protein extracts from developing wood. Diffuse reflectance FT-IR spectroscopy and pyrolysis-GC/MS analyses showed significant alternation in wood chemistry of transgenic plants including an increase in lignin content and S/G ratio, and a decrease in carbohydrate content. Sequential wood extractions confirmed a massive (+43%) increase of Klason lignin, which was accompanied by a ca. 5% decrease in cellulose, and ca. 20% decrease in wood extractives. Analysis of the monosaccharide composition using methanolysis showed a reduction of 4-O-Me-GlcA content without a change in Xyl contents in transgenic lines, suggesting that the covalent links between 4-O-Me-GlcA moieties and lignin protect these moieties from degradation. Enzymatic saccharification without pretreatment resulted in significant decreases of the yields of Gal, Glc, Xyl and Man in transgenic lines, consistent with their increased recalcitrance caused by the increased lignin content. In contrast, the enzymatic saccharification after acid pretreatment resulted in Glc yields similar to wild-type despite of their lower cellulose content. These data indicate that whereas PcGCE expression in hybrid aspen increases lignin deposition

  11. Investigation on the Effect of Chemical Foaming agent and Wood Flour content on Mechanical Properties, Density and Cell morphology of HDPE/EVA/ Wood Flour Hybrid Foamed Composites

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    Sara Pourabbasi

    2012-01-01

    Full Text Available In this research, the effects of chemical foaming agent and wood flour content on cell morphology, density and mechanical properties of HDPE/EVA/ Wood Flour hybrid foamed composites were investigated. For this aim, composites were prepared via melt mixing in an internal mixer, then foamed using single-stage batch foaming method. Then mechanical properties such as flexural strength, flexural and tensile modulus and density were measured. Morphology of the samples was also evaluated by scanning electron microscopy (SEM. The results of this study have indicated that the flexural strength, flexural and tensile modulus and density increases with the increase of wood flour content. However, with addition of chemical foaming agent content and EVA content, mechanical properties and density of foamed composites decreased. Moreover, wood fiber acted as nucleating agents that substantially reduced cell size and increased cell density. In addition, EVA plays an important role in foaming process by increasing the melt viscosity of the polymer matrix, in a way that samples with higher content of EVA have the highest cell density and the lowest cell size.

  12. 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.

  13. 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.

  14. Effect of gas saturation conditions on the expansion ratio of microcellular poly(lactic acid/wood-flour composites

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available Poly(lactic acid or PLA and PLA/wood-flour composites were microcellular foamed with CO2 through a batch foaming process. Specifically, the gas saturation pressure and time varied during processing to produce PLA foams with a high expansion ratio. A ten fold expansion ratio resulted in microcellular foamed PLA over unfoamed counterpart. The foaming conditions associated with such a high expansion ratio involved a lower gas saturation pressure up to 2.76 MPa, which corresponds to a critical gas concentration of approximately 9.4%. Beyond this critical value, foam expansion decreased significantly. Investigations also studied the effect of incorporating wood flour on the foamability of the resulting PLA/wood-flour composites. The addition of wood flour into the PLA matrix significantly affected the expansion ratio of PLA/wood-flour composite foams.

  15. 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...

  16. Respiratory and skin effects of exposure to wood dust from the rubber tree Hevea brasiliensis.

    Science.gov (United States)

    Sripaiboonkij, P; Phanprasit, W; Jaakkola, M S

    2009-07-01

    Potential health effects related to wood dust from the rubber tree, which produces natural rubber latex, have not been previously investigated. The main aim of this study was to investigate the relations of rubber tree dust exposure to respiratory and skin symptoms, asthma and lung function. A cross-sectional study was conducted among 103 workers (response rate 89%) in a rubber tree furniture factory and 76 office workers (73%) in four factories in Thailand. All participants answered a questionnaire and performed spirometry. Inhalable dust levels were measured in different work areas. Factory workers showed increased risk of wheezing, nasal symptoms and asthma compared to office workers. There was a dose-dependent increase in wheeze and skin symptoms in relation to dust level. Significantly increased risks of nasal symptoms (adj OR 3.67, 95% CI 1.45 to 9.28) and asthma (8.41, 1.06 to 66.60) were detected in the low exposure category. Workers exposed to ethyl cyanoacrylate glue had significantly increased risk of cough, breathlessness and nasal symptoms. There was dose-dependent reduction in spirometric lung function with wood dust level. This study provides new evidence that workers exposed to wood dust from the rubber tree experience increased risk of nasal symptoms, wheeze, asthma and skin symptoms and have reduced spirometric lung function. Exposure to cyanoacrylate is related to significantly increased respiratory symptoms. Results suggest that the furniture industry using rubber tree wood should implement appropriate exposure control measures to reduce wood dust exposure and cyanoacrylate glue exposure to protect their employees.

  17. 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.

  18. Wood flour

    Science.gov (United States)

    Craig M. Clemons

    2010-01-01

    The term “wood flour” is somewhat ambiguous. Reineke states that the term wood flour “is applied somewhat loosely to wood reduced to finely divided particles approximating those of cereal flours in size, appearance, and texture.” Though its definition is imprecise, the term wood flour is in common use. Practically speaking, wood flour usually refers to wood particles...

  19. Wood flour

    Science.gov (United States)

    Craig M. Clemons; Daniel F. Caufield

    2005-01-01

    The term “wood flour” is somewhat ambiguous. Reineke states that the term wood flour “is applied somewhat loosely to wood reduced to finely divided particles approximating those of cereal flours in size, appearance, and texture”. Though its definition is imprecise, the term wood flour is in common use. Practically speaking, wood flour usually refers to wood particles...

  20. 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

  1. 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.

  2. Extractives content in cooperage oak wood during natural seasoning and toasting; influence of tree species, geographic location, and single-tree effects.

    Science.gov (United States)

    Doussot, Franck; De Jéso, Bernard; Quideau, Stéphane; Pardon, Patrick

    2002-10-09

    The chemical composition of cooperage oak wood is highly variable, depending upon the tree species (Quercus robur L. versus Quercus petraea Liebl.), its geographic location, and the single-tree effect. In the process of cask-making, natural seasoning and toasting contribute strongly to the modification of the oak wood chemical composition and therefore influence wine cooperaging. HPLC and GC quantification of ellagitannins and volatile compounds such as whiskey-lactones, eugenol, and vanillin over a sample set of 61 pedunculate oaks and 72 sessile oaks originating from six different forests showed that natural drying leads to a decrease of the ellagitannins and total extractives content level and a quasi constant level of the volatile compounds. Toasting (medium type) drastically enhanced the loss of ellagitannins and the gain in volatile compounds. Statistical treatment showed that the species effect remained significant throughout the process of drying and toasting, but not the provenance. The poor correlation with ring width of extractives levels measured on fresh timber remained unchanged as did the single-tree effect, with high variability found for all chemical parameters. These results provide further evidence that cooperage oak selection should not be based solely on the wood grain or the provenance but rather on a species-provenance combination.

  3. Effect of smoke, charred wood, and nitrogenous compounds on seed germination of ten species from woodland in central-western Spain.

    Science.gov (United States)

    Pérez-Fernández, M A; Rodríguez-Echeverría, S

    2003-01-01

    The effect of smoke, charred wood, and nitrogenous compounds on germination was tested on 10 species of the Cistaceae, Poaceae, Fabaceae, and Asteraceae, from fire-prone, shrubby woodlands in central-western Spain. Dry seeds were exposed to smoke, by watering with distilled water-charred wood suspensions, or NaNO2, KNO3, NH4Cl, and NH4NO3. Smoke enhanced germination in 9 of 10 of the species. In species of Poaceae, germination was stimulated by 20 min of smoke exposure. In Asteraceae and Fabaceae species, 10 min of smoke exposure was the most effective treatment for enhancing germination. Three species--Cistus ladanifer, Cistus crispus, and Cistus monspeliensis--had a positive response to 20 min of smoke exposure; germination of Cistus salviifolius L. was also enhanced after 10 min. The effect of charred wood was variable, with no consistent germination pattern within the families. Trifolium angustifolium and Retama sphaerocarpa showed no stimulation of germination under most of the charred wood concentrations. Similarly, germination of Senecio jacobea under the charred wood treatment did not surpass that of the control. NaNO2 promoted seed germination in Dactylis glomerata (10 mM), Cistus ladanifer (1, 10, and 25 mM), and Cistus crispus (1 and 10 mM). KNO3 enhanced germination in Dactylis glomerata (1 and 25 mM), Dittrichia viscosa (10 and 25 mM), C. ladanifer (1, 10, and 25 mM), Cistus crispus (1 and 25 mM), and C. salviifolius aud C. monspeliensis (25 mM). NH4Cl induced germination of Dactylis glomerata and Dittrichia viscosa (1 mM), and Cistus species germinated best in 25 mM of this salt. NH4NO3 induced germination only in Cistus species. Holcus lanatus had the highest level of germination regardless of treatment.

  4. Effect of biochar on mechanical and flame retardant properties of wood - Plastic composites

    Science.gov (United States)

    Zhang, Qingfa; Cai, Hongzhen; Yang, Keyan; Yi, Weiming

    Biochar/wood/plastic composites were prepared with different biochar content by the extrusion method, and the mechanical properties and flame retardant properties were tested. The study indicated that: with the increase of biochar content, the mechanical properties of the composites tended to rise at first and then fell. This suggested that the appropriate amount of biochar can promote the mechanical properties of the biochar/wood/plastic composites. Though both Mg(OH)2 and Al(OH)3 could improve the Flame retardant properties of the material evidently, Mg(OH)2 obtained a better effect than Al(OH)3. In particular, when the adding amount of Mg(OH)2 is 40 wt%, the flame retardant effect is the best. Al(OH)3 can reduce the mechanical properties of the material, while Mg(OH)2 could evidently promote the tensile strength and impact resistance strength of the material.

  5. 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.

  6. Effect of long-term forest fertilization on Scots pine xylem quality and wood borer performance.

    Science.gov (United States)

    Heijari, Juha; Nerg, Anne-Marja; Kainulainen, Pirjo; Noldt, Uwe; Levula, Teuvo; Raitio, Hannu; Holopainen, Jarmo K

    2008-01-01

    We tested whether changes in long-term nutrient availability would affect the xylem quality and characteristics of Scots pine trees as a food source for the larvae of the xylophagous wood borer Hylotrupes bajulus L. (Cerambycidae). We looked for an effect of host plant growth and xylem structural traits on H. bajulus larval performance, and looked for delayed effects of long-term forest fertilization on xylem chemical quality. In general, larval performance was dependent on larval developmental stage. However, the growth of larvae also varied with host plant quality (increases in the concentration of nitrogen and carbon-based secondary compounds of xylem were correlated with a decrease in the larval growth rate). The greater annual growth of trees reduced tracheid length and correlated positively with second-instar H. bajulus growth rate. This is consistent with the hypothesis that intrinsic growth patterns of host plants influence the development of the xylophagous wood borer H. bajulus.

  7. 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.

  8. 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...

  9. Effects of wood pulp fibre concentration on gas hold-up in bubble ...

    African Journals Online (AJOL)

    Effects of wood pulp fibre concentration on gas hold-up in bubble columns. LK Witika, X Qui. Abstract. No Abstract. Journal of Science and Technology Vol. 9(2) 2005: 35-40. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/jost.v9i2.17546.

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

    OpenAIRE

    Turkay Turkoglu; Ergun Baysal; Hilmi Toker

    2015-01-01

    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 ...

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

    National Research Council Canada - National Science Library

    Islam, Md. Saiful; Hamdan, Sinin; Ahmad, Mansor B; Hasan, Mahbub; Hassan, Azman; Haafiz, M. K. Mohamad; Jawaid, M

    2014-01-01

    ...). 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...

  12. Effect of particle geometry and micro-structure on fast pyrolysis of beech wood

    NARCIS (Netherlands)

    Westerhof, Roel Johannes Maria; Nygard, H.; van Swaaij, Willibrordus Petrus Maria; Kersten, Sascha R.A.; Brilman, Derk Willem Frederik

    2012-01-01

    The influence of particle geometry and microstructure in fast pyrolysis of beech wood has been investigated. Milled wood particles (<0.08–2.4 mm) and natural wood cylinders (2–14 mm) with different lengths (10–50 mm) and artificial wood cylinders (Dp = 0.5–14 mm) made of steel walls, filled with

  13. 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 %.

  14. Modelling the effects of a radiation induced polymer impregnation on the moisture of wood-polymer composites

    Science.gov (United States)

    Boey, Freddy Y. C.; Chia, Lawrence H. L.

    The adverse effect of moisture diffusion on the properties of wood has been one of the main weaknesses of wood. Using a gamma irradiation method, wood-polymer composites have been produced which exhibit significant improvement in mechanical properties like compression, creep deformation and creep rupture particularly at high humidity. It has been thought that the impregnation of polymer into the wood has affected the moisture diffusion in the wood, so that its adverse effects on the mechanical properties has been reduced. In this report the apparent diffusion coefficients of a Ramin wood impregnated with varying amounts of polymethyl methacrylate (PMMA) were determined using a Fick's law approach. An initial linear relationship was found for impregnation of up to 70% PMMA, after which the diffusion coefficient levels off to a maximum value, for the three environmental relative humidity levels of 40, 60 and 90(±5)%. The phenomenon could be explained by means of a cylindrical model with the polymer added as an internal layer onto the wood cell wall. The average maximum reduction in the value of the diffusion coefficient was about 60%.

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

    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.

  16. 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

    2017-03-30

    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.

  17. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Directory of Open Access Journals (Sweden)

    Sensho Honma

    2014-01-01

    Full Text Available The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds.

  18. Effect of catalytic pyrolysis conditions using pulse current heating method on pyrolysis products of wood biomass.

    Science.gov (United States)

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800 °C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800 °C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds.

  19. Effect of Catalytic Pyrolysis Conditions Using Pulse Current Heating Method on Pyrolysis Products of Wood Biomass

    Science.gov (United States)

    Honma, Sensho; Hata, Toshimitsu; Watanabe, Takashi

    2014-01-01

    The influence of catalysts on the compositions of char and pyrolysis oil obtained by pyrolysis of wood biomass with pulse current heating was studied. The effects of catalysts on product compositions were analyzed using GC-MS and TEM. The compositions of some aromatic compounds changed noticeably when using a metal oxide species as the catalyst. The coexistence or dissolution of amorphous carbon and iron oxide was observed in char pyrolyzed at 800°C with Fe3O4. Pyrolysis oil compositions changed remarkably when formed in the presence of a catalyst compared to that obtained from the uncatalyzed pyrolysis of wood meal. We observed a tendency toward an increase in the ratio of polyaromatic hydrocarbons in the pyrolysis oil composition after catalytic pyrolysis at 800°C. Pyrolysis of biomass using pulse current heating and an adequate amount of catalyst is expected to yield a higher content of specific polyaromatic compounds. PMID:25614894

  20. 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

    . At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast......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...

  1. A Revised Multi-Fickian Moisture Transport Model To Describe Non-Fickian Effects In Wood

    DEFF Research Database (Denmark)

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

    2007-01-01

    . At high relative humidities, the effect of this complex moisture transport system becomes apparent, and since a single Fickian diffusion equation fails to model the behavior, it has been referred to as non-Fickian or anomalous behavior. At low relative humidities, slow bound-water transport and fast......This paper presents a study and a refinement of the sorption rate model in a so-called multi-Fickian or multiphase 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. 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.

  3. EFFECT OF AGE AND CLONE ON THE QUALITY OF Eucalyptus spp WOOD AIMING BIOENERGY PRODUCTION

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814587The aim of this work was to evaluate the effect of age and clone on the quality of Eucalyptus spp wood aiming the production of charcoal and bioenergy. Four Eucalyptus spp clones at the ages of 57 and 69 months were evaluated. Four trees per clone in each age were evaluated. The average basic density, the basic density at the DBH, higher heating value and contents of lignin, total extractives, ashes, holocellulose an elemental chemica analylsis (C, H, N, S and O were evaluated. In the evaluation of the assay, and entirely randomized design in the factorial scheme 4 x 2 was used. Besides, a multivariate analysis of main components was made. In general, it was observed effect of age on wood quality. Ash, hydrogen and nitrogen contents tended to diminish with increases in age for all the clones evaluated. However, oxygen content presented an increase with the increase in age of the clones. Lignin content presented significant increase with age increase, being the contrary observed for holocellulose content. The clones at the age of 69 months presented the highest contents of lignin, but the same did not happen for basic density of wood. The clones I144 and I220 had the highest average values for this characteristic, what may be advantageous for charcoal production. 

  4. 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.

  5. Rules of the road: A qualitative and quantitative synthesis of large wood transport through drainage networks

    Science.gov (United States)

    Kramer, Natalie; Wohl, Ellen

    2017-02-01

    To effectively manage wood in rivers, we need a better understanding of wood mobility within river networks. Here, we review primarily field-based (and some numerical) studies of wood transport. We distinguish small, medium, large, and great rivers based on wood piece dimensions relative to channel and flow dimensions and dominant controls on wood transport. We suggest further identification and designation of wood transport regimes as a useful way to characterize spatial-temporal network heterogeneity and to conceptualize the primary controls on wood mobility in diverse river segments. We draw analogies between wood and bedload transport, including distinguishing Eulerian and Lagrangian approaches, exploring transport capacity, and quantifying thresholds of wood mobility. We identify mobility envelopes for remobilization of wood with relation to increasing peak discharges, stream size, and dimensionless log lengths. Wood transport in natural channels exhibits high spatial and temporal variability, with discontinuities along the channel network at bankfull flow and when log lengths equal channel widths. Although median mobilization rates increase with increasing channel size, maximum mobilization rates are greatest in medium-sized channels. Most wood is transported during relatively infrequent high flows, but flows under bankfull can transport up to 30% of stored wood. We use conceptual models of dynamic equilibrium of wood in storage and of spiralling wood transport paths through drainage networks, as well as a metaphor of traffic on a road, to explore discontinuous wood movement through a river network. The primary limitations to describing wood transport are inappropriate time scales of observation and lack of sufficient data on mobility from diverse rivers. Improving models of wood flux requires better characterization of average step lengths within the lifetime travel path of a piece of wood. We suggest that future studies focus on: (i) continuous or high

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

    OpenAIRE

    Cho, Nam-Seok; Matsumoto, Yuji; 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...

  7. Studying the effect of fire retardant coating on the fire hazard characteristics of wood using infrared thermography

    Science.gov (United States)

    Kasymov, Denis; Agafontsev, Mikhail

    2017-10-01

    This paper represents a study concerning the effect of fire retardant treatment «FUKAM» on the fire hazard characteristics of pine, aspen and larch. The front of model ground fire was investigated to estimate its effect on the surface of wood samples. Infrared thermography was used as a diagnostic method. The surface temperature distribution was obtained for the test wood samples after exposure to a fire front that was modeled using pine needles. The probability of ignition was estimated for the chosen experimental parameters for each kind of wood. The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated samples.

  8. PRE-TREATMENTS EFFECTS ON Hovenia dulcis Thunb. WOOD DRYING RATE

    Directory of Open Access Journals (Sweden)

    Magnos Alan Vivian

    2010-11-01

    Full Text Available This study aimed to evaluate the effect of pre-treatments on drying rate of uva-do-japão wood (Hovenia dulcis Thunb.. For this, samples of wood species concerned with dimensions of 2,0 x 10,0 x 20,0 cm (E x L x C, were subjected to pre-treatment of soaking in hot water and freezing. The pre- treatments of heating and freezing were conducted in a thermal tank at 85ºC and a freezer at -18ºC, respectively, where the samples remained for 12 and 24 hours for both treatments. After the pre-treatments, the wood samples were dried in an electric oven at temperatures of 60 and 90°C until the final moisture content. Thedrying rate was significantly influenced by pre-treatments, drying temperature and their duration of them. This rate presented a different behavior according to the duration of treatment: the warning was higher with 12hours whereas the freezing, with 24 hours, was more evident. The increasing duration and temperature observed showed that the tendency of the drying rate is to increase.

  9. Statistical identification of effective input variables. [SCREEN

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. 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...

  11. Freshwater reservoir effect variability in Northern Germany

    OpenAIRE

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fishbones, shells, human bones or food crusts on pottery from sites next to rivers or lakes. The reservoir age in rivers containing considerable amounts of dissolved 14C-free carbonates can be up to several thousand years and may be highly variable. For accurate radiocarbon dating of freshwater-based samples, the order of magnitude of the reservoir effect as well as the degree of variability has to be known.The ini...

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

    Science.gov (United States)

    Chen, Feng; Han, Guangping; Li, Qingde; Gao, Xun; Cheng, Wanli

    2017-01-01

    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. PMID:28772646

  13. 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.

  14. Impregnation of Scots pine and beech with tannin solutions: effect of viscosity and wood anatomy in wood infiltration.

    Science.gov (United States)

    Tondi, G; Thevenon, M F; Mies, B; Standfest, G; Petutschnigg, A; Wieland, S

    The impregnation process of Scots pine and beech samples with tannin solutions was investigated. The two materials involved in the process (impregnation solution and wood samples) are studied in depth. Viscosity of mimosa tannin solutions and the anatomical aspect of beech and Scots pine were analysed and correlated. The viscosity of tannin solutions presents a non-newtonian behaviour when its pH level increases, and in the case of addition of hexamine as a hardener, the crosslinking of the flavonoids turns out to be of great importance. During the impregnation of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.), the liquid and solid uptakes were monitored while taking into consideration the different conditions of the impregnation process. This method allowed to identify the best conditions needed in order to get a successful preservative uptake for each wooden substrate. The penetration mechanism within the wood of both species was revealed with the aid of a microscopic analysis. Scots pine is impregnated through the tracheids in the longitudinal direction and through parenchyma rays in the radial direction, whereas in beech, the penetration occurs almost completely through longitudinal vessels.

  15. Freshwater reservoir effect variability in Northern Germany

    DEFF Research Database (Denmark)

    Philippsen, Bente; Heinemeier, Jan

    2012-01-01

    The freshwater reservoir effect is a potential problem when radiocarbon dating fishbones, shells, human bones or food crusts on pottery from sites next to rivers or lakes. The reservoir age in rivers containing considerable amounts of dissolved 14C-free carbonates can be up to several thousand...... years and may be highly variable. For accurate radiocarbon dating of freshwater-based samples, the order of magnitude of the reservoir effect as well as the degree of variability has to be known. The initial problem in this case was the accurate dating of food crusts on pottery from the Mesolithic sites...... and variability that can also be expected for the past. Water DIC from different seasons, and from the same season in different years, has been dated because it is the carbon source in photosynthesis and thus at the basis of the rivers’ food webs. The radiocarbon ages of underwater plants and different parts...

  16. Effects of role variables on job satisfaction.

    Science.gov (United States)

    Sherman, E C

    1998-01-01

    This study examines the effects of role variables on job satisfaction among physician and non-physician executives in hospital settings. Positive relationships were found for both groups between role variables and job satisfaction. The results indicate that role variables have a significant effect on stress, job satisfaction, and organizational commitment in the physician executive and the non-physician health care executive. On a theoretical level, this research allowed for an extended test of role theory, specifically as it applies to the management of health care. The implications of these findings for role theory and the physician executive are discussed. Since this study is of an exploratory nature, it offers new insights into the field of health care management, and the physician's role as the executive.

  17. The Effect of Chemical Modification with Phenol Formaldehyde and Compression on Mechanical Properties of Paulownia (P.fortunie Wood

    Directory of Open Access Journals (Sweden)

    Mozhgan Sakalo

    2012-06-01

    Full Text Available Shortages of raw wood materials and increasing demand for this raw material, has created challenges for wood working industries. These situation makes wood industries to use wood of fast growing species, such as Paulownia. Expanding plantations of paulownia is a feasible solution, but this species owns a low specific gravity and mechanical properties as well. In this research effects of compreg– impregnated (by phenol for maldehyde resin treatment on improving mechanical properties of paulownia was studied. Test materials were compressed in tangential and radial directions by 3, 30, 40 and 50 percent at 170 ˚c temperature for 12 minute. Specimens were cut from treated test materials and tested according to Iso-3133 & 3787. Result have shown that resin treatment improves all mechanical properties except toughness. Control specomens had higher toughness as compared with treated ones. MOE and MOR did increase, and turned to be highest specomens compressed 50 % in redial direction.

  18. 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.

  19. 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.

  20. The effect of mid-rotation fertilization on the wood properties of loblolly pine (Pinus taeda)

    Science.gov (United States)

    Finto Antony; Lewis Jordan; Laurence R. Schimleck; Richard F. Daniels; Alexander Clark III

    2009-01-01

    Mid-rotation fertilization is a common practice in the management of loblolly pine (Pinus taeda L.) plantations, typically providing large improvements in growth. However, concerns exist about the quality of wood produced following fertilization. The objective of this study was to develop an understanding of wood property changes following fertilization. Wood...

  1. 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...

  2. 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...

  3. 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

  4. 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.

  5. EFFECTS OF SOME BORON COMPOUNDS AND/OR WATER REPELLENTS ON THE HIGROSCOPICITY OF BRUTIA PINE (Pinus brutia Ten. WOOD

    Directory of Open Access Journals (Sweden)

    M. Kemal YALINKILIÇ

    1995-03-01

    Full Text Available As a water borne salt type, boron salts also tend to increase in hygroscopicity of wood. This phonomenon is known as one of the disadvantages of these salts in wood preservation in spite of their protective effectiveness against biological agents and fire. This study was designed to determine the rate of higroscopicity both treated and untreated Brutia pine wood. Impregnation solutions of boric acid (BA and sodium perborate (SP was prepared by water and polyethylene glycol (PEG-400 (P4. Additionally, some water repellents (WRs such as paraffin wax (P, styrene (St, methylmethacrylate (MMA and isocyanate (ISO were used to keep the hygroscopicity level of wood at an acceptable level. Results indicated that paraffin wax and WRs were considerably lowered the hygroscopicity of wood. 4 homogenity groups were formed from the statistical analysis as follows (from the most hygroscopic treatments to lesser, respectively: (1 P4, (2 P4+BA or SP, control, (3 WRs, BA or SP+WRs and, (4 P+BA+Bx (% 15 aqueous solution. None of the solutions increased the hygroscopicity of wood than control treatments, but P4 (P? 0.05.

  6. Effects of nano-zinc oxide based paint on weathering performance of coated wood

    OpenAIRE

    Can, Ahmet; Sivrikaya, Hüseyin

    2014-01-01

    Nano-sized zinc oxide (ZnO) was chosen as a suitable candidate for the UV-protection of coatings. The accelerated weathering performances of Scots pine coated with wood paint mixed with nano- ZnO were investigated. Uncoated specimens, specimens coated with only nano-ZnO and nano-zinc oxide based paint were used as references. This work describes the effect of the nanoparticles and paint performance on accelerated weathering performance of coated specimens. 1 ml and 3 ml nano-zinc oxide is add...

  7. 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...

  8. WOOD WELDING

    OpenAIRE

    Marcos Theodoro Muller; Rafael Rodolfo de Melo; Diego Martins Stangerlin

    2010-01-01

    The term "wood welding" designates what can be defined as "welding of wood surfaces". This new process, that it provides the joint of wood pieces without the use of adhesives or any other additional material, provokes growing interest in the academic environment, although it is still in laboratorial state. Linear friction welding induced bymechanical vibration yields welded joints of flat wood surfaces. The phenomenon of the welding occurs in less time than 10 seconds, with the temperature in...

  9. Effect of oral contraceptives on haemostasis variables.

    Science.gov (United States)

    Kluft, C; Lansink, M

    1997-07-01

    Combined oral contraceptives (COCs) have effects on a large number of haemostasis variables. We have summarised literature data on effects of COCs containing 30-35 micrograms ethinyl estradiol for the third generation of progestogens (PGs): desogestrel, gestodene and norgestimate. It is concluded that about 15 variables show a shift in distribution of the order of magnitude of their interindividual variation coefficient. When comparing the third generation of PGs with the second one (norgestrel, levonorgestrel) stronger increases are noted for the former for some haemostatic variables. Also differences between desogestrel and gestodene for factor VII were apparent. It indicates that the role of PGs in the effects of COCs is significant and their design may in addition to reduction of oestrogen dosage be important in reducing haemostatic complications. The survey on molecular and cellular mechanisms by which the sex steroids might operate showed a great lack of knowledge. Only for factor XII has a functional oestrogen response element in the DNA definitely been identified. The study of molecular markers of coagulation and fibrinolysis have shown a distinct increased activation of coagulation (F 1 + 2, FPA) and fibrinolysis (PAP), and an increased fibrin turn-over (increased FDPs); platelet products are not found increased (beta TG, PF-4). The increase in fibrinolysis represent a counterforce, but individual changes in variables in coagulation and fibrinolysis do not correlate indicating independent effects and no evidence for a individually regulated balance. A first step in further research might be in understanding the increase in coagulation activation (F 1 + 2) which has so far not been satisfactorily related to changes in blood concentrations of haemostatic factors and possibly local factors.

  10. Modeling the Effect of Helical Fiber Structure on Wood Fiber Composite Elastic Properties

    Science.gov (United States)

    Marklund, Erik; Varna, Janis

    2009-08-01

    The effect of the helical wood fiber structure on in-plane composite properties has been analyzed. The used analytical concentric cylinder model is valid for an arbitrary number of phases with monoclinic material properties in a global coordinate system. The wood fiber was modeled as a three concentric cylinder assembly with lumen in the middle followed by the S3, S2 and S1 layers. Due to its helical structure the fiber tends to rotate upon loading in axial direction. In most studies on the mechanical behavior of wood fiber composites this extension-twist coupling is overlooked since it is assumed that the fiber will be restricted from rotation within the composite. Therefore, two extreme cases, first modeling fiber then modeling composite were examined: (i) free rotation and (ii) no rotation of the cylinder assembly. It was found that longitudinal fiber modulus depending on the microfibril angle in S2 layer is very sensitive with respect to restrictions for fiber rotation. In-plane Poisson’s ratio was also shown to be greatly influenced. The results were compared to a model representing the fiber by its cell wall and using classical laminate theory to model the fiber. It was found that longitudinal fiber modulus correlates quite well with results obtained with the concentric cylinder model, whereas Poisson’s ratio gave unsatisfactory matching. Finally using typical thermoset resin properties the longitudinal modulus and Poisson’s ratio of an aligned softwood fiber composite with varying fiber content were calculated for various microfibril angles in the S2 layer.

  11. 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

  12. Assemblage composition of fungal wood-decay species has a major influence on how climate and wood quality modify decomposition.

    Science.gov (United States)

    Venugopal, Parvathy; Junninen, Kaisa; Edman, Mattias; Kouki, Jari

    2017-03-01

    The interactions among saprotrophic fungal species, as well as their interactions with environmental factors, may have a major influence on wood decay and carbon release in ecosystems. We studied the effect that decomposer diversity (species richness and assemblage composition) has on wood decomposition when the climatic variables and substrate quality vary simultaneously. We used two temperatures (16 and 21°C) and two humidity levels (70% and 90%) with two wood qualities (wood from managed and old-growth forests) of Pinus sylvestris. In a 9-month experiment, the effects of fungal diversity were tested using four wood-decaying fungi (Antrodia xantha, Dichomitus squalens, Fomitopsis pinicola and Gloeophyllum protractum) at assemblage levels of one, two and four species. Wood quality and assemblage composition affected the influence of climatic factors on decomposition rates. Fungal assemblage composition was found to be more important than fungal species richness, indicating that species-specific fungal traits are of paramount importance in driving decomposition. We conclude that models containing fungal wood-decay species (and wood-based carbon) need to take into account species-specific and assemblage composition-specific properties to improve predictive capacity in regard to decomposition-related carbon dynamics. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2010-12-01

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

  14. In vitro hypoglycemic effects of hot water extract from Auricularia polytricha (wood ear mushroom).

    Science.gov (United States)

    Wu, Ni-Jung; Chiou, Fu-Jing; Weng, Yih-Ming; Yu, Zer-Ran; Wang, Be-Jen

    2014-06-01

    Viscous dietary fibers were shown to alleviate postprandial blood glucose. Auricularia polytricha (wood ear mushroom, WEM) contains rich amount fibers and water extract WEM was highly viscous. This study aimed to investigate whether WEM extract exhibited hypoglycemic effect in vitro. The effects of WEM extract on glucose adsorption, glucose diffusion, starch digestion and α-amylase activity were examined and compared to those of two high soluble fibers, psyllium and oat fiber and one insoluble fiber, cellulose. Our results showed that WEM extract and psyllium possessed similar ability to adsorb glucose which may thus decrease the level of dialysis glucose. The decrease of dialysis rate is dose-dependent. WEM extract can also suppress the activity of α-amylase which may thus inhibit the digestion of polysaccharides. Since WEM extract exhibited the ability to adsorb glucose and to suppress the activity of α-amylase; it might contribute a beneficial effect on postprandial levels of blood sugar.

  15. 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.

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tothova, Slavka [Forest Research Inst., Kolice (Slovakia)

    2005-07-01

    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{sub 3} {sup -}. 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.

  18. WOOD BASIC DENSITY EFFECT OF Eucalyptus grandis x Eucalyptus urophylla CLONES ON BLEACHED PULP QUALITY

    Directory of Open Access Journals (Sweden)

    Sheila Rodrigues dos Santos

    2010-08-01

    Full Text Available The study analyzed the wood basic density effect in two Eucalyptus grandis x Eucalyptus urophylla hybrid clones (440 kg/m3 e 508 kg/m3 on bleached pulp quality (fiber dimensions and physical-mechanical properties. The woods performance on pulping, bleaching and beating results were analyzed. The Kraft pulping was carried out in forced circulation digester in order to obtain 17±1 kappa number targets. The pulps were bleached to 90±1 using delignification oxygen and D0EOPD1 bleaching sequence. Bleached pulp of low basic density clone showed, significantly, lowest revolutions number in the PFI mill to reach tensile index of 70 N.m/g, low Schopper Riegler degree and generated sheets with higher values to bulk and opacity. These characteristics and properties allow concluding that bleached pulp of low basic density clone was the most indicated to produce printing and writing sheets. The bleached pulp of high basic density clone showed higher values of bulk and capillarity Klemm and lower water retention value when analyzed without beating. The bleached pulp of high basic density clone showed more favorable characteristics to the production of tissue papers.

  19. THE EFFECT OF SOLVENT EXCHANGE ON THE PIT ASPIRATION IN ORIENTAL SPRUCE (Picea orientalis (L. Link. WOOD

    Directory of Open Access Journals (Sweden)

    Hamiyet Şahin

    2003-04-01

    Full Text Available This study investigated the effect of solvent Exchange drying utilizing low surface tension force of organic solvents on pit aspiration in Oriental spruce wood. All trees used for experiments were obtained from Maçka-Karahava region. Investigations for pit aspiration was carried out on electron microscope. Prior to the experiments, samples dried with solvent Exchange method. The principle of this method was the replacement of free water in wood with an organic solvent, low in surface tension. The applied organic solvents were acetone, benzene and pentane. For comparison purposes, pit aspiration experiment also were conducted on oven-dried and air-dried wood samples. Result inticated that solvent Exchange drying was observed to be effective on pit aspiration, and the best result was obtained by acetone treatment.

  20. Sublethal effects on wood frogs chronically exposed to environmentally relevant concentrations of two neonicotinoid insecticides.

    Science.gov (United States)

    Robinson, Stacey A; Richardson, Sarah D; Dalton, Rebecca L; Maisonneuve, France; Trudeau, Vance L; Pauli, Bruce D; Lee-Jenkins, Stacey S Y

    2017-04-01

    Neonicotinoids are prophylactically used globally on a variety of crops, and there is concern for the potential impacts of neonicotinoids on aquatic ecosystems. The intensive use of pesticides on crops has been identified as a contributor to population declines of amphibians, but currently little is known regarding the sublethal effects of chronic neonicotinoid exposure on amphibians. The objective of the present study was to characterize the sublethal effect(s) of exposure to 3 environmentally relevant concentrations (1 μg/L, 10 μg/L, and 100 μg/L) of 2 neonicotinoids on larval wood frogs (Lithobates sylvaticus) using outdoor mesocosms. We exposed tadpoles to solutions of 2 commercial formulations containing imidacloprid and thiamethoxam, and assessed survival, growth, and development. Exposure to imidacloprid at 10 μg/L and 100 μg/L increased survival and delayed completion of metamorphosis compared with controls. Exposure to thiamethoxam did not influence amphibian responses. There was no significant effect of any treatment on body mass or size of the metamorphs. The results suggest that current usage of imidacloprid and thiamethoxam does not pose a threat to wood frogs. However, further assessment of both direct and indirect effects on subtle sublethal endpoints, and the influence of multiple interacting stressors at various life stages, is needed to fully understand the effects of neonicotinoids on amphibians. Environ Toxicol Chem 2017;36:1101-1109. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

  1. 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...

  2. Effect of compression wood on leaching of chromium, copper, and arsenic from CCA-C treated red pine (Pinus resinosa Ait.)

    Science.gov (United States)

    S. Nami. Kartal; Stan. Lebow

    2000-01-01

    In this study, the effect of compression wood formation on the release rate of chromium, copper, and arsenic elements from red pine (Pinus resinosa Ait) was investigated. Wood blocks from red pine containing compression and normal wood portions were treated with a 1.0% CCA-C solution and were then allowed to fix at 23 * 2*C (74 * 4*F) for 0, 6, 24, 48, 96, 192, and 336...

  3. 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

  4. 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

  5. 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.

  6. 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....

  7. [Inhibition effects of wood vinegar on Alternaria panax and Botrytis cinerea].

    Science.gov (United States)

    Li, Xiang-guo; Han, Lian-hua; Wu, Song-quan; Piao, Ren-zhe; Liu, Hai-feng

    2014-09-01

    Less fungicides could be used to biocontrol Alternaria panax and Botrytis cinerea, this experiment can offer preliminary theory for wood vinegar as a botanic fungicide. The in vitro inhibition activities of wood vinegar on Alternaria panax and Botrytis cinerea were tested by using mycelial growth rate method and spore germination method. Inhibition of mycelium growth rate to Alternaria panax was 100% when the concentration of wood vinegar was no less than 3.0%, while the inhibition of mycelium growth rate and spore germination rate were 70.68% and 84.47%, respectively, at concentration of wood vinegar 2.25%. Inhibition of mycelium growth rate and spore germination rate to Botrytis cinerea were 100% when the concentration of wood vinegar was no less than 2.25%. Wood vinegar concentration of no less than 2.25% can be used as a biocontrol agent of Alternaria panax and Botrytis cinerea, it is useful for the further field trial.

  8. Combined effects of ZnO particle deposition and heat treatment on dimensional stability and mechanical properties of poplar wood.

    Science.gov (United States)

    Cui, Wei; Zhang, Nannan; Xu, Min; Cai, Liping

    2017-08-30

    This study proposed a one-step wood modification method by combining the deposition of ZnO particles on wood surface and heat treatment. The effects of ZnO particles and heat treatment on mechanical properties and dimensional stability of poplar wood were examined. Samples were sorted into 4 groups, i.e., control, heat-treated, impregnation/heat-treated, and hydrothermal-treated samples. The mechanical properties and dimensional stability of impregnation/heat-treated and hydrothermal-treated wood samples were measured in comparison with those of the control and heat-treated wood samples. Compared with the control ones, the reduction of the flexural strength of the heat-treated, impregnation/heat-treated and hydrothermal-treated samples were about 11.57%, 8.53% and 15.90%, respectively. The modulus of elasticity of the heat-treated and hydrothermal-treated samples decreased by 13.78% and 23.78%, respectively, while the impregnation/heat-treated samples increased by about 8.57% due to the ZnO particles growth. The dimensional stabilities of the heat-treated, impregnated/heat-treated and hydrothermal-treated samples were improved in comparison with that of the control sample. All samples were characterized by the scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X - ray diffraction (XRD).

  9. Effect of silicone oil heat treatment on the chemical composition, cellulose crystalline structure and contact angle of Chinese parasol wood.

    Science.gov (United States)

    Okon, Kufre Edet; Lin, Fengcai; Chen, Yandan; Huang, Biao

    2017-05-15

    The effect of silicone oil heat treatment (SOTH) on the chemical composition, cellulose crystalline structure, thermal degradation and contact angle of Chinese parasol wood were examined in this study. Samples were heated at 150°C, 180°C and 210°C for 2h and 8h, after SOHT chemical composition, fourier transformed infrared (FTIR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) of the treated samples were evaluated. Results showed that the chemical components of the wood were affected after SOHT particularly when treated at 210°C for 8h. Changes in the chemical components was due to the degradation of biopolymer components of the wood during SOHT. The crystallinity index of cellulose and contact angle of the SOHT samples was increased. The findings demonstrate the potential of SOHT for modification of wood. Thus an economical and eco-friendly approach to thermally modified wood was achieved in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 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

  11. Effects of a catalytic converter on PCDD/F, chlorophenol and PAH emissions in residential wood combustion.

    Science.gov (United States)

    Kaivosoja, T; Virén, A; Tissari, J; Ruuskanen, J; Tarhanen, J; Sippula, O; Jokiniemi, J

    2012-07-01

    Catalytic converters can be used to decrease carbon monoxide, organic compounds and soot from small-scale wood-fired appliances. The reduction is based on the oxidation of gaseous and particulate pollutants promoted by catalytic transition metal surfaces. However, many transition metals have also strong catalytic effect on PCDD/F formation. In this study birch logs were burned in a wood-fired stove (18 kW) with and without a catalytic converter with palladium and platinum as catalysts. PCDD/F, chlorophenol and PAH concentrations were analyzed from three phases of combustion (ignition, pyrolysis and burnout) and from the whole combustion cycle. PCDD/F emissions without the catalytic converter were at a level previously measured for wood combustion (0.15-0.74 ng N m(-3)). PAH emissions without the catalytic converter were high (47-85 mg N m(-3)) which is typical for batch combustion of wood logs. Total PAH concentrations were lower (on average 0.8-fold), and chlorophenol and PCDD/F levels were substantially higher (4.3-fold and 8.7-fold, respectively) when the catalytic converter was used. Increase in the chlorophenol and PCDD/F concentrations was most likely due to the catalytic effect of the platinum and palladium. Platinum and palladium may catalyze chlorination of PCDD/Fs via the Deacon reaction or an oxidation process. The influence of emissions from wood combustion to human health and the environment is a sum of effects caused by different compounds formed in the combustion. Therefore, the usage of platinum and palladium based catalytic converters to reduce emissions from residential wood combustion should be critically evaluated before wide-range utilization of the technology. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Structural performance of light-frame roof assemblies. I, Truss assemblies designed for high variability and wood failure

    Science.gov (United States)

    R.W. Wolfe; Monica McCarthy

    1989-01-01

    The first report of a three-part series that covers results of a full-scale roof assemblies research program. The focus of this report is the structural performance of truss assemblies comprising trusses with abnormally high stiffness variability and critical joint strength. Results discussed include properties of truss members and connections. individual truss...

  14. 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.

  15. 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

    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......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...

  16. Bioprocessing preservative-treated waste wood

    Science.gov (United States)

    Barbara L. Illman; Vina W. Yang; Les. Ferge

    2000-01-01

    Disposal of preservative-treated waste wood is a growing problem worldwide. Bioprocessing the treated wood offers one approach to waste management under certain conditions. One goal is to use wood decay fungi to reduce the volume of waste with an easily managed system in a cost-effective manner. Wood decay fungi were obtained from culture collections in the Mycology...

  17. Durability of Wood in Ground Contact – Effects of Specimen Size

    Directory of Open Access Journals (Sweden)

    Christian BRISCHKE

    2017-06-01

    Full Text Available The durability of wood in ground contact is affected by its material resistance on the one hand, and the exposure situation in the ground on the other hand. The latter is considered to be one of the most severe not at least due to permanent wetting and direct contact to a well-established microbial flora. In addition to physical, chemical, biological, and ecological soil parameters, the design of a wooden commodity which is in contact with the ground can have an effect on its durability. This study examined the effect of size of specimens used for in-ground durability tests. Standard EN 252 specimens, smaller mini-stake specimens, and larger double-size specimens were made from Scots pine sapwood and heartwood (Pinus sylvestris L., Norway spruce (Picea abies Karst., beech (Fagus sylvatica L., and English oak (Quercus robur L. and exposed in ground in a test field in Hannover-Herrenhausen, Germany. In addition, standard size specimens were exposed on the ground. Decay rates and corresponding durability classes according to European standards were determined. Decay proceeded slightly faster with decreasing specimen size, but for the majority of the tested materials no significant effect became apparent. However, the most durable material tested was English oak, for which durability was clearly affected by the specimen size. It was classified ‚durable’ (durability class DC 2 using double size stakes, ‚moderately durable’ (DC 3 using standard specimens, and ‚less durable’ (DC 4 using mini-stake specimens. Specimens exposed on-ground decayed significantly less rapidly compared to specimens buried in the ground to half of their length. The findings from this study recommend to use also test specimens, which are bigger dimensioned than standard specimens and thus closer in dimension to real size commodities. Otherwise, one might accept to underestimate the durability of particular wood-based materials.

  18. 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

  19. 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 (...

  20. Functional Wood

    OpenAIRE

    Cronhjort, Yrsa (ed.); Hughes, Mark (ed.); Paakkanen, Mikko (ed.); Sahi, Karola (ed.); Tukiainen, Pekka (ed.); Tulamo, Tomi (ed.); Vahtikari, Katja (ed.)

    2016-01-01

    Design has been recognized as a key discipline to bring ideas to the market. In addition to current research on human perceptions and the functional capacities of wood, this publication demonstrates the potential of wood in various applications. The designs are the results of three design courses, implemented during 2015 and 2016 at Aalto University in Finland. The Masters student courses included two Wood Studios at Aalto University’s School of Arts, Design and Architecture and the Integrate...

  1. 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.

  2. 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.

  3. Effect of particle size on the composition of lignin derived oligomers obtained by fast pyrolysis of beech wood

    NARCIS (Netherlands)

    Zhou, Shuai; Garcia-Perez, Manuel; Pecha, Brennan; McDonald, Armando G.; Westerhof, Roel Johannes Maria

    2014-01-01

    The effect of particle size on the yield and composition of lignin derived oligomers (also known as pyrolytic lignin (PL)) was studied in a fluidized bed reactor. Milled beech wood particles of sizes between 0.3 and 0.55 and cylinders of 3–14 mm were pyrolyzed at 500 °C. The lignin oligomers were

  4. 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

  5. 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

    Harvest of forest biomass for energy production may lead to export of nutrients from the forest. Recirculation of nutrients from wood chip combustion by ash spreading in forests has been proposed as a means for counteracting the nutrient export. This study was carried out to examine the effect of...

  6. 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...

  7. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA-TREATED WOOD

    Science.gov (United States)

    This is a 2 year study designed to evaluate the effectiveness of a variety of deck sealants in reducing or eliminating potential exposure to arsenic, chromium, and copper from chromated copper arsenate-treated wood used in residential settings, like decks and playsets.

  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. 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-...

  10. Effect of particle size, coupling agent and DDGS additions on Paulownia wood polypropylene composites

    Science.gov (United States)

    The mechanical, flexural, thermal, and physical characteristics of wood plastic composites employing Paulownia wood (PP) flour derived from 36-mo-old trees blended with polypropylene (PP) were analyzed. Composites of 25% and 40% w/w of PW and 0-10% by weight of maleated polypropylene (MAPP) were pr...

  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. The effects of different silane crosslinking approaches on composites of polyethylene blends and wood flour

    Science.gov (United States)

    Craig M. Clemons; Ronald C. Sabo; Kolby C. Hirth

    2011-01-01

    Though silane chemistry has been used to crosslink unfilled polyethylene for many years, such crosslinking has only been recently applied to wood plastic composites to improve properties such as creep resistance. However, the presence of wood significantly changes the silane chemistry and a greater understanding is necessary for optimal processing and performance. We...

  13. Inhibitory effect of essential oils on decay fungi and mold growth on wood

    Science.gov (United States)

    Vina W. Yang; Carol A. Clausen

    2007-01-01

    Structural damage and potential health risks caused by wood decay and mold fungi in residential structures have been a major concern for homeowners, building contractors and insurance companies alike. The combined damage from decay fungi and mold claims exceeds several billion US dollars annually. Protection against decay and mold growth on wood is a critical economic...

  14. The effect of polarity of extractives on the durability of wood

    Science.gov (United States)

    Roderquita K. Moore; Jonathan Smaglick; Erick Arellano-ruiz; Michael Leitch; Doreen Mann

    2015-01-01

    Extractives are low molecular weight compounds and regarded as nonstructural wood constituents. These compounds are present in trees and can be extracted by organic solvents. Extractives consist of several classes of compounds that diversify the biological function of the tree. Fats are an energy source for the wood cells whereas terpenoids, resin acids, and phenolic...

  15. Mechanical properties of small-scale laminated wood composite poles: effects of taper and webs

    Science.gov (United States)

    Cheng Piao; Todd F. Shupe; R.C. Tang; Chung Y. Hse

    2006-01-01

    Laminated hollow wood composite poles represent an efficient utilization of the timber resource and a promising alternative for solid poles that are commonly used in the power transmission and telecommunication lines. The objective of this study was to improve the performance of composite poles by introducing the bio-mimicry concept into the design of hollow wood...

  16. 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...

  17. Visual versus chemical evaluation: Effects of pruning wood decomposition on soil quality in a cherry orchard (Northeast Germany).

    Science.gov (United States)

    van Dongen, Renee; Germer, Sonja; Kern, Jürgen; Stoorvogel, Jetse

    2016-04-01

    Returning crop residues to the soil is a well-known practice to keep a sustainable soil quality in agriculture. In an orchard, pruning material could be returned for soil and water conservation or could be removed for energy production. Pruning wood decomposition rates and their impact on soil quality and greenhouse-gas emissions depend on climate, soil type, land management and water availability. Changing the soil management from leaving wood prunings on soil to removing them from the orchard is expected to result in a slow but lasting change of soil quality. Therefore a quick and cost-effective technique for soil quality evaluation is needed. This study aims to compare pruning wood decomposition effects on soil quality determined by soil chemistry (pH, C/N-ratio) or by Visual Soil Examination and Evaluation (VSEE). In addition, treatments effects on soil quality were compared for sampling positions in tree rows versus interrows. In a cherry orchard (Northeast Germany) six plots were established spreading over two planting rows. At each plot, three subplots with 1x (0.55 kg/m2), 2x (1.10 kg/m2) and 10x (5.50 kg/m2) the average pruning wood rates were installed in both tree and interrows. 5 months later the soils were sampled and a Visual Soil Evaluation and Examination (VSEE) was applied. To relate wood decomposition to impacts on soil quality, wood bags were placed in each plot and were sampled in time intervals of 5 weeks (till a maximum of 20 weeks). Wood decomposition was characterized by decomposition rates and changes in carbon and nitrogen contents. To assess environmental effects, CO2, N2O and CH4 emissions or uptake from soils with different pruning rates were determined with the closed chamber method. There were no significant differences in pH and C/N-ratio between the 3 pruning rates. However, pH was significant higher in the tree row compared to the interrow for the 10-fold pruning rate. The 10-fold pruning rate had significant higher VSEE

  18. 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 at meso...... arrangements and cellulose strength distributions on the tensile strength of wood is studied numerically. Good agreement of the theoretical results with experimental data has been obtained.......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...

  19. 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...

  20. Untreated and copper-treated wood soaked in sodium oxalate: effects of decay by copper-tolerant and copper-sensitive fungi

    Science.gov (United States)

    Katie M. Ohno; Grant T. Kirker; Amy B. Bishell; Carol A. Clausen

    2017-01-01

    Copper is widely used as the primary component in wood protectants because it demonstrates a broad range of biocidal properties. However, a key concern with using copper in wood preservative formulations is the possibility for brown-rot basidiomycetes to resist the toxic effect. Many brown-rot basidiomycetes have evolved mechanisms, like the production and accumulation...

  1. The Effect of Stringer Repair Methods and Repair Frequency on the Performance of GMA-Style 48x40-Inch Wood Pallets

    Science.gov (United States)

    John W. Clarke; Marshall S. White; Philip A. Araman

    2004-01-01

    Over 135 million wood pallets were repaired for reuse in 1995. One of the most commonly damaged components in a wood pallet is the notched stringer. Metal plates, half companion stringers, and full companion stringers are repair methods described in the U.S. industry standard published by the American Society of Mechanical Engineers. This study evaluated the effect of...

  2. Potential Effects of Wood Chip Mill Harvests on Economic Returns and Forest Management Practices of Nonindustrial Private Forest Landowners in North Carolina

    Science.gov (United States)

    Anthony Snider; Frederick Cubbage; Robert Moulton

    2001-01-01

    Four approaches were used to estimate the market effects of wood chip mills for nonindustrial private forest (NIPF) landowners. First, we used economic welfare analyses to estimate potential changes in consumer and producer surplus that might be attributed to increased stumpage demand created by wood chip mills. Better markets would consistently increase economic...

  3. Effect of Wood Ash Fertilization on Soil Chemical Properties and Stand Nutrient Status and Growth of Some Coniferous Stands in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Saarsalmi, Anna; Maelkoenen, Eino; Kukkola, Mikko [Finnish Forest Research Inst. Vantaa (Finland)

    2004-06-01

    The effects of wood ash or wood ash plus nitrogen (N) fertilization on soil chemical properties, needle nutrient concentrations and tree growth were studied in five coniferous stands, aged 31-75 yrs, after 5 and 10 yrs. In each experiment 3 t/ha of loose wood ash was applied to three replicated plots (30 x 30 m). In three of the experiments 120-150 kg N/ha was applied together with the same wood ash (WAN). These three experiments also included a stand-specific fertilization (SSF) treatment, which consisted of 120, 150 or 180 kg N/ha. Five years after wood ash or WAN application the pH increase in the humus layer was 1-1.7 pH-units and in the 0-5 cm mineral soil layer 0.3-0.4 pH-units. The increase was approximately the same 10 yrs after application, and was also associated with an increase in pH in the 5-10 cm mineral soil layer. Wood ash or WAN significantly increased both the total and extractable calcium and magnesium concentrations in the humus layer on all the sites. Wood ash or WAN had an increasing effect on the boron concentrations, but a decreasing effect on the manganese concentrations in the needles. Wood ash had no significant effect on the volume growth. The trees on the WAN plots grew as well as or slightly better than those on the SSF plots.

  4. Using ring width correlations to study the effects of plantation density on wood density and anatomical properties of red pine (Pinus resinosa Ait.)

    Science.gov (United States)

    J. Y. Zhu; C. T. Scott; K. L. Scallon; G. C. Myers

    2006-01-01

    This study demonstrated that average ring width (or average annual radial growth rate) is a reliable parameter to quantify the effects of tree plantation ndensity (growth suppression) on wood density and tracheid anatomical properties. The average ring width successfully correlated wood density and tracheid anatomical properties of red pines (Pinus resinosa Ait.) from...

  5. Wildfires and water chemistry: effect of metals associated with wood ash.

    Science.gov (United States)

    Cerrato, José M; Blake, Johanna M; Hirani, Chris; Clark, Alexander L; Ali, Abdul-Mehdi S; Artyushkova, Kateryna; Peterson, Eric; Bixby, Rebecca J

    2016-08-10

    The reactivity of metals associated with ash from wood collected from the Valles Caldera National Preserve, Jemez Mountains, New Mexico, was assessed through a series of laboratory experiments. Microscopy, spectroscopy, diffraction, and aqueous chemistry measurements were integrated to determine the chemical composition of wood ash and its effect on water chemistry. Climate change has caused dramatic impacts and stresses that have resulted in large-scale increases in wildfire activity in semi-arid areas of the world. Metals and other constituents associated with wildfire ash can be transported by storm event runoff and negatively affect the water quality in streams and rivers. Differences among ash from six tree species based on total concentrations of metals such as Ca, Al, Mg, Fe, and Mn were identified using non-metric multidimensional analysis. Metal-bearing carbonate and oxide phases were quantified by X-ray diffraction analyses and X-ray spectroscopy analyses. These metal-bearing carbonate phases were readily dissolved in the first 30 minutes of reaction with 18 MΩ water and 10 mM HCO3(-) in laboratory batch experiments which resulted in the release of metals and carbonates in the ash, causing water alkalinity to increase. However, metal concentrations decreased over the course of the experiment, suggesting that metals re-adsorb to ash. Our results suggest that the dissolution of metal-bearing carbonate and oxide phases in ash and metal re-adsorption to ash are relevant processes affecting water chemistry after wildfire events. These results have important implications to better understand the impact of wildfire events on water quality.

  6. 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...

  7. The effect of geometric structure on stiffness and damping factor of wood applicable to machine tool structure

    Directory of Open Access Journals (Sweden)

    Susilo Adi Widyanto

    2013-06-01

    Full Text Available Stiffness and vibration damping capability are important criteria in design of machine tool structure. In other sides, the weight of machine tool structure must be reduced to increase  the handling capability. This paper presents  an analysis of the effect of geometric structure on stiffness and vibration damping of wood structure.  The stiffness was analysed  using numerical method, so called finite element method (FEM, while the vibration damping capability was experimentally tested. Vibration testing was also performed to wood structures with sand powder filled  into  its rectangular hole to observe the its effect on damping factor. Simulation results show  that the cross ribs structure yielded minimum mass reduction ratio compared to the three square holes as well as the single rectangular hole structures. While the vibration test results explained that the damping factor of Shorea laevis wood was higher than that Hevea braziiensis wood. The use of sand powder as vibrating  mass in closed-box structure effectively increased the damping capability, for single rectangular hole structure the damping factor was increased from 0.048 to 0.079doi: http://dx.doi.org/10.12777/ijse.4.2.2013.57-60[How to cite the article: Widyanto, S. A., Widodo, A., Nugroho, S., & Siahaan, D. (2013. The effect of geometric structure on stiffness and damping factor of wood applicable to machine tool structure. INTERNATIONAL JOURNAL OF SCIENCE AND ENGINEERING, 4(2, 57-60. doi: http://dx.doi.org/10.12777/ijse.4.2.2013.57-60

  8. Dynamic Processes of Large Wood and Their Effects on Fluvial Export at the Watershed Scale

    Science.gov (United States)

    Seo, J.; Nakamura, F.; Chun, K.

    2008-12-01

    The presence of large wood (LW) has a pronounced impact on the geomorphic and ecological character of river corridors, yet relatively little is known about the patterns and processes at the watershed scale. To understand these patterns we monitored the volumetric input of LW into 131 reservoirs and a suite of watershed characteristics. Of all geomorphic and hydrologic variables tested, watershed area was most important in explaining LW export. LW export per unit watershed area was relatively high in small watersheds, peaked in intermediate-sized watersheds and decreased in large watersheds. To explain these variations, we surveyed the amount of LW with respect to channel morphology in 78 segments (26 segments in each size class) in the Nukabira River, northern Japan, and examined the differences in LW dynamics, including its recruitment, transport, storage, and fragmentation and decay along the spectrum of watershed sizes. We found in small watersheds a larger proportion of LW produced by forest dynamics and hillslope processes was retained due to narrower valley floors and lower stream power. The retained LW pieces may eventually be exported during debris flows. In intermediate-sized watersheds the volume of LW pieces derived from hillslopes decreased substantially with reductions of proportion of channel length bordered by hillslope margins, which potentially deliver large quantities of LW. Because these channels have lower wood piece length to channel width ratios and higher stream power, LW pieces can be transported downstream. During transport, LW pieces are further fragmented and can be more easily transported; and therefore, the fluvial export of LW is maximized in intermediate-sized watersheds. Rivers in large watersheds, where the recruitment of LW is limited by the decreasing hillslope margins, cannot transport LW pieces because of their low stream power and thus LW pieces accumulate at various storage sites. Although these stored LW pieces can be re

  9. The Effects of Heat Treatment on the Physical Properties and Surface Roughness of Turkish Hazel (Corylus colurna L. Wood

    Directory of Open Access Journals (Sweden)

    Nevzat Çakıcıer

    2008-09-01

    Full Text Available Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on the physical properties and surface roughness of Turkish Hazel (Corylus colurna L. wood were examined. Samples obtained from Kastamonu Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for different durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements, using the stylus method, wereb made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra, mean peak-to-valley height (Rz, root mean square roughness (Rq, and maximum roughness (Ry obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p = 0.05 between physical properties and surface roughness parameters (Ra,Rz, Ry, Rq for three temperatures and three durations of heat treatment. The results showed that the values of density, swelling and surface roughness decreased with increasing temperature treatment and treatment times. Turkish Hazel wood could be utilized successfully by applying proper heat treatment techniques without any losses in investigated parameters. This is vital in areas, such as window frames, where working stability and surface smoothness are important factors.

  10. 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.

  11. Quantitative Wood Anatomy-Practical Guidelines

    National Research Council Canada - National Science Library

    von Arx, Georg; Crivellaro, Alan; Prendin, Angela L; Čufar, Katarina; Carrer, Marco

    2016-01-01

    Quantitative wood anatomy analyzes the variability of xylem anatomical features in trees, shrubs, and herbaceous species to address research questions related to plant functioning, growth, and environment...

  12. 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.

  13. Effects of polychlorinated dibenzo-p-dioxins and dibenzofurans on nesting wood ducks (Aix sponsa) at Bayou Meto, Arkansas.

    Science.gov (United States)

    White, D H; Hoffman, D J

    1995-05-01

    Wood ducks (Aix sponsa) nesting along Bayou Meto downstream from a hazardous waste site in central Arkansas were contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Residues in eggs, based on 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ), ranged up to 611 parts per trillion (ppt), and egg arithmetic means were 90-fold higher at the site nearest the point source compared with a reference site. We monitored productivity of wood ducks in artificial nest boxes at three sites on the bayou and at a reference site on a separate drainage during 1988-1990. Productivity was suppressed (p nests. The threshold range of toxicity, where reduced productivity was evident in wood ducks (based on TCDD-EQs), was > 20 to 50 ppt. Oxidative stress and teratogenic effects occurred in ducklings at the more contaminated nesting sites nearest the point source. These findings suggest that wood ducks may be more sensitive to PCDD and PCDF contamination than some other aquatic birds and could serve as an indicator species for monitoring biological impacts from these contaminants.

  14. Effect of Impact Modifier Type on Water Absorption and Thickness Swelling Parameters of Wood Flour- Recycled Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Saman Ghahri

    2012-01-01

    Full Text Available In this research, the effect of impact modifier type on water diffusion coefficient, maximum water absorption and thickness swelling parameters of wood flour- recycled polypropylene composites were evaluated. For this purpose, a virgin PP was thermo-mechanically degraded by two times extrusion under controlled conditions in a twin-screw extruder at a rotor speed of 100 rpm and a temperature of 1900C. The virgin and recycled PP in 2nd stage, compatibilizer (0, 2 % w/w and wood flour were compounded at 50% weight sawdust loading in a counter-rotating twin-screw extruder in presence different type of impact modifiers (0, 6 % w/w. Ethylene vinyl acetate (EVA, ethylene-propylene-diene monomer (EPDM and acrylonitrile-butadiene-styrene (ABS were used as impact modifiers. The analysis of diffusion mechanism and thickness swelling rate were done based on Fick’s theory and swelling model for wood flour- recycled polypropylene composites. The composites containing two times recycled PP exhibited lower moisture diffusion coefficients, swelling rate parameter, maximum water absorption, thickness swelling. Also results showed that moisture diffusion coefficients and thickness swelling parameters of composites containing EVA are lower than composites containing EPDM and ABS. The use of compatibilizer decreased the moisture diffusion coefficients and thickness swelling parameters of the wood flour- recycled polypropylene composites

  15. Accumulation and effects of lead and cadmium on wood ducks near a mining and smelting complex in Idaho.

    Science.gov (United States)

    Blus, L J; Henny, C J; Hoffman, D J; Grove, R A

    1993-06-01

    : A study of wood ducks (Aix sponsa) was conducted along the Coeur d'Alene River system in northern Idaho in 1986 and 1987. Most of this area has been subjected to severe contamination from lead and other metals from mining and smelting since the 1880s. In 1986, a preliminary study of wood duck nesting was conducted in the contaminated area; incubating hens captured in nest boxes were bled and weighed. Blood samples were used to determine lead and cadmium concentrations and physiological characteristics. In 1987, an intensive study of wood ducks involved trapping and monitoring nest boxes in the contaminated area. Blood and tissue samples were also taken from wood ducks from a reference area without known contamination from metals. Lead levels in blood and tissues of most wood ducks from the contaminated area frequently exceeded those considered hazardous to birds; maximum levels (wet weight) of lead were 8 μg g(-1) in blood and 14 μg g(-1) in liver. Changes in physiological characteristics constituted the only evidence of potentially adverse effects from lead. In the contaminated area, nesting success (55% unadjusted, 35% Mayfield estimate) was less than in other areas where predation was low and nest boxes were used; but lead concentrations and physiological characteristics of blood were similar in successful and unsuccessful hens.Values of ALAD, hemoglobin, and body mass were negatively correlated with blood concentrations of lead, whereas protoporphyrin was positively correlated with lead levels in the blood. Some of the protoporphyrin values (1,091 μg dl(-1) in a male and 756 μg dl(-1) in a female) equalled those associated with lead toxicosis in experimental birds. ALAD activity was low in most birds from the contaminated area; values of 0 were obtained from 11 birds. Lead levels in blood, ALAD, protoporphyrin, and hemoglobin were significantly different between birds from the contaminated and reference areas. Concentrations of lead in ingesta of wood

  16. Accumulation and effects of lead and cadmium on wood ducks near a mining and smelting complex in Idaho

    Science.gov (United States)

    Blus, L.J.; Henny, C.J.; Hoffman, D.J.; Grove, R.A.

    1993-01-01

    A study of wood ducks (Aix sponsa) was conducted along the Coeur d'Alene River system in northern Idaho in 1986 and 1987. Most of this area has been subjected to severe contamination from lead and other metals from mining and smelting since the 1880s. In 1986, a preliminary study of wood duck nesting was conducted in the contaminated area; incubating hens captured in nest boxes were bled and weighed. Blood samples were used to determine lead and cadmium concentrations and physiological characteristics. In 1987, an intensive study of wood ducks involved trapping and monitoring nest boxes in the contaminated area. Blood and tissue samples were also taken from wood ducks from a reference area without known contamination from metals. Lead levels in blood and tissues of most wood ducks from the contaminated area frequently exceeded those considered hazardous to birds; maximum levels (wet weight) of lead were 8 :g g?1 in blood and 14 :g g?1 in liver. Changes in physiological characteristics constituted the only evidence of potentially adverse effects from lead. In the contaminated area, nesting success (55% unadjusted, 35% Mayfield estimate) was less than in other areas where predation was low and nest boxes were used; but lead concentrations and physiological characteristics of blood were similar in successful and unsuccessful hens. Values of ALAD, hemoglobin, and body mass were negatively correlated with blood concentrations of lead, whereas protoporphyrin was positively correlated with lead levels in the blood. Some of the protoporphyrin values (1,091 :g dl?1 in a male and 756 :g dl?1 in a female) equalled those associated with lead toxicosis in experimental birds. ALAD activity was low in most birds from the contaminated area; values of 0 were obtained from 11 birds. Lead levels in blood, ALAD, protoporphyrin, and hemoglobin were significantly different between birds from the contaminated and reference areas. Concentrations of lead in ingesta of wood ducks ranged

  17. 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

  18. The antimicrobial effects of wood-associated polyphenols on food pathogens and spoilage organisms.

    Science.gov (United States)

    Plumed-Ferrer, Carme; Väkeväinen, Kati; Komulainen, Heli; Rautiainen, Maarit; Smeds, Annika; Raitanen, Jan-Erik; Eklund, Patrik; Willför, Stefan; Alakomi, Hanna-Leena; Saarela, Maria; von Wright, Atte

    2013-06-03

    The antimicrobial effects of the wood-associated polyphenolic compounds pinosylvin, pinosylvin monomethyl ether, astringin, piceatannol, isorhapontin, isorhapontigenin, cycloXMe, dHIMP, ArX, and ArXOH were assessed against both Gram-negative (Salmonella) and Gram-positive bacteria (Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus) and yeasts (Candida tropicalis, Saccharomyces cerevisiae). Particularly the stilbenes pinosylvin, its monomethyl ether and piceatannol demonstrated a clear antimicrobial activity, which in the case of pinosylvin was present also in food matrices like sauerkraut, gravlax and berry jam, but not in milk. The destabilization of the outer membrane of Gram-negative microorganisms, as well as interactions with the cell membrane, as indicated by the NPN uptake and LIVE/DEAD viability staining experiments, can be one of the specific mechanisms behind the antibacterial action. L. monocytogenes was particularly sensitive to pinosylvin, and this effect was also seen in L. monocytogenes internalized in intestinal Caco2 cells at non-cytotoxic pinosylvin concentrations. In general, the antimicrobial effects of pinosylvin were even more prominent than those of a related stilbene, resveratrol, well known for its various bioactivities. According to our results, pinosylvin could have potential as a natural disinfectant or biocide in some targeted applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

    OpenAIRE

    Wu, Zhiping; Hu, Na; Wu, Yiqiang; Wu, Shuyun; Qin, Zu

    2014-01-01

    The effect of ultrafine magnesium hydroxide (UMH) and ordinary magnesium hydroxide (OMH) on the tensile properties and flame retardancy of wood plastic composites (WPC) were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM) of fracture section of samples provided the positive evidence that the ten...

  20. Exposure and effects of urban contaminants on wood stork health and reproduction in Florida

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Considering the information provided in the previous section, the objective of the present investigation is to examine foraging habits of wood storks, as well as...

  1. Effect of Enzymatic Beech Fagus Sylvatica Wood Hydrolysate on Chlorella Biomass, Fatty Acid and Pigment Production

    National Research Council Canada - National Science Library

    Krystian Miazek; Claire Remacle; Aurore Richel; Dorothee Goffin

    2017-01-01

    .... Neutralized wood enzymatic hydrolysate containing glucose (TGP-Enz10), was tested on Chlorella growth during heterotrophic cultivation and compared with microalgae growth in a medium containing synthetic glucose (TGP...

  2. Effects of cutting orientation in poplar wood biomass size reduction on enzymatic hydrolysis sugar yield.

    Science.gov (United States)

    Zhang, Meng; Ju, Xiaohui; Song, Xiaoxu; Zhang, Xiao; Pei, Z J; Wang, Donghai

    2015-10-01

    The aim of this study was to understand how cutting orientation in poplar wood biomass size reduction affects enzymatic hydrolysis sugar yield of wood particles. A metal cutting (milling) machine was used to produce poplar wood particles from three cutting orientations. Results showed that cutting orientation significantly affected enzymatic hydrolysis sugar yield of wood particles. In this study, size reduction from the optimum cutting orientation produced 50% more sugars than the other two cutting orientations. Particles from the cutting orientation with the highest sugar yield had a large enzyme accessible area (125 mg orange dye/g biomass, as evaluated by Simons' stain procedure) and low crystallinity (50% crystallinity index, as calculated by the Segal method). Furthermore, small particle size did not necessarily lead to improvement in enzymatic digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Chemical Analysis and Study of Phenolics, Antioxidant Activity, and Antibacterial Effect of the Wood and Bark of Maclura tinctoria (L. D. Don ex Steud.

    Directory of Open Access Journals (Sweden)

    K. C. Lamounier

    2012-01-01

    Full Text Available Maclura tinctoria (L. D. Don ex Steud. has one of the highest qualities among the coefficients for Brazilian woods (up to 9.6 and resistance rates equivalent to Indian teak (Tectona grandis. In this study, the macromolecular constituents and total phenols compounds as well as the antioxidant and antibacterial activities of this wood were evaluated. Total phenols and proanthocyanidin levels were higher in wood when compared with bark levels. The antioxidant activity of wood extracts (IC50 = 18.7 μg/mL was more effective than that of bark extracts (IC50 = 20.9 μg/mL. Wood and bark extracts revealed a high potential for inhibition of aerobic and anaerobic bacteria. The bark extracts were the most active (MIC from 20 to 60 μg/mL. Both antioxidant activity and high potential for bacteria inhibition turn these extracts promising for drug formulations, especially as antibacterial agent.

  4. Effect of Cyclic Loading on Modulus of Elasticity of Aspen Wood

    OpenAIRE

    Milan Gaff; Miroslav Gašparík

    2014-01-01

    This article investigates the modulus of elasticity of solid and laminated aspen wood of various thicknesses after cyclic loading. A three-point static bending test was carried out to determine the modulus of elasticity. Cyclically loaded samples were compared with samples without cyclic loading. For the laminated wood, the results demonstrated a statistically significant impact of cyclic loading on the elasticity modulus. In contrast, no significant impact of cyclic loading was shown for the...

  5. Effect of Cultivation Methods on Wood Static Bending Properties in Alnus Glutinosa

    OpenAIRE

    Majid Kiaei

    2014-01-01

    This study was carried out to determine radial variation of wood density, modulus of elasticity (MOE), modulus of rupture (MOR) and stress at elastic limit in plantation and natural alder (Alnus glutinosa) forests in north of Iran. Testing samples were taken at breast height of the stem and at three radial positions (10, 50 and 90 % of radius) for both cultivation methods (natural and plantation forests) to determine wood mechanical strength properties according to the ASTM standard. Analysis...

  6. 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.

  7. Effects of the technolology of machining on the surface quality of selected wood

    Directory of Open Access Journals (Sweden)

    Michal Svatoš

    2011-01-01

    Full Text Available The paper deals with the dependence of using basic types of machining technologies on the surface quality of most common wood. In wood-processing industry, cutting by circular-saw blades and milling are the most often used technology to machining wood materials. The quality and accuracy of the machining are derived from the machine construction, shape and the amount of saw teeth, kind of wood species, feed per tooth and the size of the tool. Research was carried out on an experimental milling stand at setting various feed speeds and the spindle rpm, on an experimental cutting stand at using three types of circular-saw blades in the field of optimum and resonance rpm. Evaluation of the surface quality was carried out on a top multisensor apparatus Taylor Hobson-Talysurf CLI 1000 using a contactless method by a confocal sensor. Software equipment of a powerful computer was provided by the Talymap platinum program. Tree species were evaluated generally from the aspect of roughness and waviness altogether. An expert evaluation is carried out from two aspects. The first aspect is selection of the best technology for actual wood and the second aspect is selection of the best species for the actual technology. Particular relationships between wood and technology are evidently best described by graphs.

  8. 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.

  9. Effect of Handling, Packing and Transportation on the Moisture of Timber Wood

    Science.gov (United States)

    Pálková, Zuzana; Rudolfová, Martina; Georgin, Eric; Ben Ayoub, Mohamed W.; Fernicola, Vito; Beltramino, Giulio; Ismail, Nabila; Gelil, Doaa abd El; Choi, Byung Il; Heinonen, Martti

    2017-10-01

    In order to improve the efficiency of moisture meters calibrations, we studied the effect of ambient humidity, sample handling, packing and transportation on the timber wood (spruce) moisture determination. It was proved by experiments that dry timber samples (12 × 12 × 2.5 cm) reach equilibrium within 30-40 days even when moisturizing them at a high relative air humidity (80 %). On the other hand, the major mass loss of moist samples placed at normal laboratory conditions was found to occur during the first few days while the first 5 days are critical. The effects of sample handling, packing and transportation were studied by means of interlaboratory comparison between CMI, CETIAT, INRIM, NIS and KRISS. The obtained results show that samples with moisture content less than 7 % tend to absorb small amount of water, whereas samples with moisture content larger than 15 % tend to desorb small amount of water during the handling and transporting even when using vacuum packing and short handling times.

  10. 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.

  11. Effect of extending FSH treatment on superovulation and embryo production in wood bison (Bison bison athabascae).

    Science.gov (United States)

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

    2017-06-01

    The effect of extending the length of the FSH treatment protocol on superovulatory response and embryo production was investigated in wood bison during the anovulatory and ovulatory seasons. In Experiment 1 (anovulatory season), follicular wave emergence was synchronized by follicular ablation (Day -1) and bison were assigned randomly to two groups (n = 14/group) and given 200 mg FSH on Day 0 and Day 2 (non-extended group), or 133 mg FSH on Days 0, 2, and 4 (extended group). Human chorionic gonadotropin (hCG; 3000 IU) was given on Day 5 and Day 6 in the non-extended and extended groups, respectively, and bison were inseminated 12 and 24 h later. Ova/embryos were collected 8 days after hCG treatment. In Experiment 2 (ovulatory season), bison were synchronized and superstimulated as in Experiment 1 (n = 12/group), but prostaglandin was given to control CL development. Data were compared by t-test and Chi-square test. In Experiment 1, no differences in ovarian response or embryo production between groups were detected. In Experiment 2, there was no difference in the ovarian response between groups, however, a greater number of ova/embryos (4.3 ± 0.8 vs. 2.3 ± 0.4; P ≤ 0.05) and freezable embryos (2.5 ± 0.6 vs. 1.2 ± 0.4; P ≤ 0.05) were obtained in the extended group. The number of freezable embryos was greater during the ovulatory vs anovulatory season (1.8 ± 0.4 vs. 0.3 ± 0.2; P ≤ 0.05). In conclusion, extending the FSH treatment in wood bison did not improve the superovulatory response during the anovulatory season, but resulted in twice as many freezable embryos during the ovulatory season. The number of freezable embryos collected during the anovulatory season was <20% that of the ovulatory season. Copyright © 2017. Published by Elsevier Inc.

  12. 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

  13. Backwater rise due to large wood accumulations: Effect of organic fine material

    Science.gov (United States)

    Schalko, Isabella; Schmocker, Lukas; Weitbrecht, Volker; Boes, Robert M.

    2017-04-01

    Large wood (logs with a diameter ≥ 0.1 m and a length ≥ 1.0 m) in rivers improves the diversity of morphological structures and flow conditions. It may be transported as single logs or in a bulk, forming a log jam or an accumulation at an obstruction. In a natural river, large wood (LW) accumulations create heterogeneous hydraulic gradients and increase the flow resistance. Besides various ecological benefits, LW accumulations may intensify flood hazard. During flood events, transported LW may accumulate at river infrastructures or is retained intentionally at LW retention structures. In both cases, the accumulation results in an upstream backwater rise and may lead to flooding of the nearby area. Consequently, engineering measures are necessary to mitigate LW accumulation risk. The number of investigations on the role of LW during flood events has substantially increased within the last decades. At the Laboratory of Hydraulics, Hydrology, and Glaciology (VAW) of ETH Zurich, several studies were conducted on LW accumulation probability and rate. Formulae for backwater rise calculation already exist, but the governing parameters are still contradictory. In addition, the effect of organic fine material (e.g. branches or leaves in a LW accumulation) was neglected in all previous studies. In this present study, a series of small-scale and close-to-prototype model tests were conducted to identify the governing parameters on backwater rise due to LW accumulations. During the experiments, the approach flow conditions (inflow flow depth and Froude number) and LW accumulation characteristics (accumulation length, compactness of LW accumulations, LW characteristics, and organic fine material) were varied systematically. The experimental results show that the backwater rise depends mainly on the compactness of LW accumulations, approach flow Froude number, and organic fine material. The study confirms the hypothesis that organic fine material changes the accumulation

  14. The effect of predation on begging-call evolution in nestling wood warblers.

    Science.gov (United States)

    Haskell

    1999-04-01

    I combined a comparative study of begging in ground- and tree-nesting wood warblers (Parulidae) with experimental measures of the predation costs of warbler begging calls. Throughout their development, ground-nesting warbler nestlings had significantly higher-frequency begging calls than did tree-nesting warblers. There was also a trend for ground-nesting birds to have less rapidly modulated calls. There were no consistent associations between nesting site and the amplitude of the calls. Using miniature walkie-talkies hidden inside artificial nests, I reciprocally transplanted the begging calls of 5- and 8-day-old black-throated blue warblers, Dendroica caerulescens (tree-nesting) and ovenbirds, Seiurus aurocapillus (ground-nesting) and measured the corresponding changes in rates of nest predation. For the begging calls of 8-day-old nestlings, but not those of 5-day-olds, the calls of the tree-nesting species coming from ground nests incurred greater costs than did the calls of ground nesters. The reciprocal transplant had little effect on the rate of predation. Tooth imprints on clay eggs placed in artificial nests indicated that eastern chipmunks, Tamias striatus, were responsible for the increased cost of begging for black-throated blue calls coming from the ground. These data suggest that nest predation may be responsible for maintaining some of the interspecific differences in the acoustic structure of begging calls. Copyright 1999 The Association for the Study of Animal Behaviour.

  15. Pyrolysis polygeneration of poplar wood: Effect of heating rate and pyrolysis temperature.

    Science.gov (United States)

    Chen, Dengyu; Li, Yanjun; Cen, Kehui; Luo, Min; Li, Hongyan; Lu, Bin

    2016-10-01

    The pyrolysis of poplar wood were comprehensively investigated at different pyrolysis temperatures (400, 450, 500, 550, and 600°C) and at different heating rates (10, 30, and 50°C/min). The results showed that BET surface area of biochar, the HHV of non-condensable gas and bio-oil reached the maximum values of 411.06m(2)/g, 14.56MJ/m(3), and 14.39MJ/kg, under the condition of 600°C and 30°C/min, 600°C and 50°C/min, and 550°C and 50°C/min, respectively. It was conducive to obtain high mass and energy yield of bio-oil at 500°C and higher heating rate, while lower pyrolysis temperature and heating rate contributed towards obtaining both higher mass yield and energy yield of biochar. However, higher pyrolysis temperature and heating rate contributed to obtain both higher mass yield and energy yield of the non-condensable gas. In general, compared to the heating rate, the pyrolysis temperature had more effect on the product properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Effects of heat treatment on sound absorption coefficients in nanosilver-impregnated and normal solid woods.

    Science.gov (United States)

    Esmailpour, Ayoub; Taghiyari, Hamid Reza; Zolfaghari, Habib

    2017-06-01

    Effects of impregnation with silver nano-suspension as well as heat-treatment on sound absorption coefficients (AC) were studied in tangential direction of five different solid woods based on their importance. AC was measured at two frequencies of 250 and 500 Hz. A 400 ppm nanosuspension was used for the impregnation; silver nanoparticles had a size range of 30-80 nm. Based on the obtained results, the species reacted significantly different in absorbing sound at the two frequencies. Impregnation with nano-suspension substantially decreased AC at the lower frequency of 250 Hz; it did not show any particular trend when AC was measured at the frequency of 500 Hz. Heat treatment significantly increased AC at the frequency of 250 Hz. ACs of mulberry tended to be similar at the two frequencies; in the other four species though, ACs were significantly different. High significant correlations were found in the hardwoods between the ACs measured at the two frequencies.

  17. Wood handbook : wood as an engineering material.

    Science.gov (United States)

    Forest Products Laboratory

    1999-01-01

    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.

  18. 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

  19. 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.

  20. 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

  1. Effect of age and diameter class on the properties of wood from clonal Eucalyptus

    Directory of Open Access Journals (Sweden)

    Wilma Michele Santos Santana

    2012-03-01

    Full Text Available The objective of this work was to evaluate the influence of age and diameter class on the physical, thermal and chemical characteristics of a clone of Eucalyptus grandis and Eucalyptus urophylla. The material originated from a reforestation site owned by GERDAU S.A. and included trees at age 34, 48, 61, 74 and 86 months. Two trees were selected per age in each diameter class, observing the proportion of each established plot. Analyses of physical characteristics included wood basic density, dry matter weight and carbon stock, and of chemical characteristics included holocellulose, total extractives content, total lignin and ash content, in addition to elemental and thermal analysis of the wood. Results led to the conclusion that most wood properties were influenced by age and diameter class. The species was found to have great potential for production of biomass and generation of heat energy, potentially convertible into mechanical energy and electricity.

  2. Structural quantification of wood fibre surfaces--morphological effects of pulping and enzymatic treatment.

    Science.gov (United States)

    Chinga-Carrasco, Gary; Johnsen, Per Olav; Øyaas, Karin

    2010-08-01

    Wood fibres have been utilized by our society as an important component of paper products and are presently gaining more interest as reinforcement in composite materials. During the last decades biochemical treatments have also found applications in the processing of wood fibres. The chemical, mechanical and biochemical treatments affect the morphology of the fibre wall structure at the micro- and nano-level. In this study, we present a modern approach where field-emission SEM (FE-SEM) and relevant computerized image analysis are applied to quantify the fibre wall characteristics. Details such as surface roughness and texture of the fibre walls are quantified objectively. Global polar plots are generated, which are considered to represent the fingerprint of a given pulp. The approach offers a novel perspective in the characterisation of surface structures, moving forward from performing subjective evaluations to performing objective quantifications of wood pulp fibre surfaces. (c) 2010 Elsevier Ltd. All rights reserved.

  3. Effect of anatomical and chemical structure in the permeability of "Amapá" wood

    Directory of Open Access Journals (Sweden)

    Edy Eime Pereira Baraúna

    2014-12-01

    Full Text Available This paper aimed to study the permeability to air and liquid, in the longitudinal direction of "amapá" wood (Brosimum parinarioides Ducke, originating from the Amazon Forest. Furthermore, the influence of anatomical and chemical characteristics in the permeability of the wood was investigated. For this study, samples were collected from three trees, in the state of Pará, Brazil, and submitted to permeability test, anatomical characterization, and chemical analyses. The permeability to the air of the "amapá" wood was estimated at 63.7.10-9 m3.[m.(N.m-2.s]-1 and to the liquid was 2.07.10-9 m3.[m.(N.m-2.s]-1. There were low correlations between air and liquid permeability and the anatomical features.

  4. 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

  5. Effect of carbon dioxide injection on production of wood cement composites from waste medium density fiberboard (MDF).

    Science.gov (United States)

    Qi, H; Cooper, P A; Wan, H

    2006-01-01

    The possibility of recycling waste medium density fiberboard (MDF) into wood-cement composites was evaluated. Both new fibers and recycled steam exploded MDF fibers had poor compatibility with cement if no treatment was applied, due to interference of the hydration process by the water soluble components of the fiber. However, this issue was resolved when a rapid hardening process with carbon dioxide injection was adopted. It appears that the rapid carbonation allowed the board to develop considerable strength before the adverse effects of the wood extractives could take effect. After 3-5 min of carbon dioxide injection, the composites reached 22-27% of total carbonation and developed 50-70% of their final (28-day) strength. Composites containing recycled MDF fibers had slightly lower splitting tensile strength and lower tensile toughness properties than those containing new fibers especially at a high fiber/cement ratio. Composites containing recycled MDF fibers also showed lower values of water absorption. Unlike composites cured conventionally, composites cured under CO(2) injection developed higher strength and toughness with increased fiber content. Incorporation of recycled MDF fibers into wood cement composites with CO(2) injection during the production stage presents a viable option for recycling of this difficult to manage waste material.

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

    Energy Technology Data Exchange (ETDEWEB)

    Brink, Nico van den, E-mail: nico.vandenbrink@wur.n [Alterra, Wageningen UR, Box 47, NL-6700AA, Wageningen (Netherlands); Lammertsma, Dennis; Dimmers, Wim; Boerwinkel, Marie-Claire; Hout, Annemariet van der [Alterra, Wageningen UR, Box 47, NL-6700AA, Wageningen (Netherlands)

    2010-01-15

    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 Cd, Cu and Zn these effects propagated through the food web to the wood mouse. Soil-to-kidney ratios differed between sites: Cd: 0.15 versus 3.52, Cu: 0.37 versus 1.30 and Zn: 0.33-0.83. This was confirmed in model calculations for Cd and Zn. Results indicate that total soil concentrations may be unsuitable indicators for risks that metals pose to wildlife. Furthermore, environmental managers may, unintentionally, change soil properties while taking specific environmental measures. In this way they may affect risks of metals to wildlife, even without changes in total soil concentrations. - Soil properties significantly affect accumulation of heavy metals to wood mice so; risks cannot be based on total concentrations.

  7. Effect of Spacing Regimes on Growth, Yield, and Wood Properties of Tectona grandis at Longuza Forest Plantation, Tanzania

    Directory of Open Access Journals (Sweden)

    Eliakimu Zahabu

    2015-01-01

    Full Text Available This study examined the effects of planting spacing on growth, yield, and wood properties of teak planted at square spacing regimes of 2 m, 3 m, and 4 m at Longuza Forest Plantation, Tanzania. To achieve this, tree, stand, and wood properties were studied at age of 14 years. Results showed that diameter at breast height and total height increased with increasing spacing. Mean annual increment increased significantly with increasing spacing while spacing did not have significant effect on total volume production and basal area. Basic density is also not affected by spacing while heartwood proportion increases as planting spacing increases. All studied wood properties (modulus of rupture, modulus of elasticity, compression strength tangential to grain, and shear tangential to the grain except cleavage tangential to grain were not significantly affected by increasing spacing. It is recommended to use the spacing of 3 × 3 m, but if thinning can be done before onset of competition at 5 years, the currently used spacing of 2.5 × 2.5 m can still be used. However, the use of a spacing of 4 × 4 m can give at least 50% heartwood at shorter rotation age of 30 years.

  8. Effect of climate variability on sugarcane breeding in Nigeria | Ishaq ...

    African Journals Online (AJOL)

    Effect of climate variability on sugarcane breeding in Nigeria. ... Flowering in sugarcane (Saccharum species) is poor and variable at many tropical locations due to sub-optimal photoperiod. The situation is often compounded by ... sugar production in Nigeria. Keywords: Climate Change, Variability and Sugarcane Breeding ...

  9. 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

  10. 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

    has often exploited the different structural properties created by the material’s inherent anisotropy. When experimenting with protective methods against marine borers, such as shipworm, the British Standard BS EN 275:1992 is often used. The standard states that wood blocks are cut in tangential......When exposed on the seabed, waterlogged archaeological wood in the marine environment can be subjected to degradation by Teredo navalis (commonly known as shipworm). The degradation is swift and devastating as the artefact can disappear within months. In-situ preservation of archaeological...... materials has become more widespread since the UNESCO Convention on the Protection of the Underwater Cultural Heritage and the Valletta Treaty. Therefore, there is a need to understand the attack rate of T. navalis taking the anisotropy of wood into consideration, primarily because in the past ship building...

  11. Effects of Silviculture and Genetics on Branch/Knot Attributes of Coastal Pacific Northwest Douglas-Fir and Implications for Wood Quality—A Synthesis

    Directory of Open Access Journals (Sweden)

    Eini C. Lowell

    2014-07-01

    Full Text Available Douglas-fir is the most commercially important timber species in the US Pacific Northwest due to its ecological prevalence and its superior wood attributes, especially strength and stiffness properties that make it highly prized for structural applications. Its economic significance has led to extensive establishment and management of plantations over the last few decades. Cultural treatments and genetic improvement designed to increase production of utilizable wood volume also impact tree morphology and wood properties. Many of these impacts are mediated by crown development, particularly the amount and distribution of foliage and size and geometry of branches. Natural selection for branch architecture that optimizes reproductive fitness may not necessarily be optimal for stem volume growth rate or for wood properties controlling the quality of manufactured solid wood products. Furthermore, Douglas-fir does not self-prune within the rotation lengths currently practiced. This paper synthesizes extensive Douglas-fir research in the Pacific Northwest addressing: (1 the effects of silviculture and genetics on branch structure and associated consequences for wood quality and the product value chain; and (2 methods to measure, monitor, modify, and model branch attributes to assist managers in selecting appropriate silvicultural techniques to achieve wood quality objectives and improve the value of their Douglas-fir resource.

  12. The Effect of Variability in Price on Consumer Brand Choice

    OpenAIRE

    B. P. S. Murthi; Ernan Haruvy; He Zhang

    2007-01-01

    Grocery store managers change prices on a weekly basis either as part of price promotions or in response to changes on their supply side. Consumers experience this price variability and may respond to it. Even though behavioral literature suggests that price variability affects consumers' decisions, most brand choice models have not focused on the consumers' response to such variability. This study attempts to remedy this omission and examine the effect of price variability on consumer brand ...

  13. Effects of physical variables on settling velocities of calcium and ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Effects of physical variables on settling velocities of calcium and strontium phosphates ... Department of Chemistry, Rivers State University of Science & Technology, Port Harcourt, Nigeria .... simplified stoichiometric chemical reactions.

  14. Wood decomposing abilities of diverse lignicolous fungi on nondecayed and decayed beech wood.

    Science.gov (United States)

    Fukasawa, Yu; Osono, Takashi; Takeda, Hiroshi

    2011-01-01

    We tested the decay abilities of 28 isolates from 28 lignicolous fungal species (Basidiomycota, Ascomycota and Zygomycota) with the pure culture test. We used beech wood powder in varying moisture conditions and decay stages (nondecayed, intermediately decayed and well decayed) as substrates. The weight loss in wood powder was -0.2-17.8%. Five isolates of Basidiomycota (Bjerkandera adusta, Mycena haematopus, Omphalotus guepiniformis, Trametes hirsuta, Trametes versicolor) caused high weight losses in nondecayed wood. We detected significant effects of decay stage on weight loss in wood in most isolates tested, whereas moisture content rarely had an effect on weight loss. Among Basidiomycota and Xylariaceae in Ascomycota weight loss was greater for nondecayed wood than for intermediately and well decayed wood. In contrast four isolates in Ascomycota (Scytalidium lignicola, Trichoderma hamatum, T. harzianum, T. koningii) caused substantial weight loss in intermediately and well decayed wood, although they rarely caused weight loss in nondecayed wood. Zygomycota caused low weight loss in wood. Wood decay stages also affected decomposition of wood chemical components. Acid-unhydrolyzable residue (AUR) decomposition was reduced, whereas holocellulose decomposition was stimulated by some strains of Basidiomycota and Ascomycota in well decayed wood. T. harzianum in particular caused significant weight loss of holocellulose in well decayed wood, although this fungus caused negligible weight loss of both AUR and holocellulose in nondecayed wood. We discuss these changes in the decay patterns of AUR and holocellulose with varying wood decay stages in relation to the role of fungal decomposition of woody debris in forests.

  15. Signature wood modifications reveal decomposer community history.

    Directory of Open Access Journals (Sweden)

    Jonathan S Schilling

    Full Text Available Correlating plant litter decay rates with initial tissue traits (e.g. C, N contents is common practice, but in woody litter, predictive relationships are often weak. Variability in predicting wood decomposition is partially due to territorial competition among fungal decomposers that, in turn, have a range of nutritional strategies (rot types and consequences on residues. Given this biotic influence, researchers are increasingly using culture-independent tools in an attempt to link variability more directly to decomposer groups. Our goal was to complement these tools by using certain wood modifications as 'signatures' that provide more functional information about decomposer dominance than density loss. Specifically, we used dilute alkali solubility (DAS; higher for brown rot and lignin:density loss (L:D; higher for white rot to infer rot type (binary and fungal nutritional mode (gradient, respectively. We first determined strength of pattern among 29 fungi of known rot type by correlating DAS and L:D with mass loss in birch and pine. Having shown robust relationships for both techniques above a density loss threshold, we then demonstrated and resolved two issues relevant to species consortia and field trials, 1 spatial patchiness creating gravimetric bias (density bias, and 2 brown rot imprints prior or subsequent to white rot replacement (legacy effects. Finally, we field-tested our methods in a New Zealand Pinus radiata plantation in a paired-plot comparison. Overall, results validate these low-cost techniques that measure the collective histories of decomposer dominance in wood. The L:D measure also showed clear potential in classifying 'rot type' along a spectrum rather than as a traditional binary type (brown versus white rot, as it places the nutritional strategies of wood-degrading fungi on a scale (L:D=0-5, in this case. These information-rich measures of consequence can provide insight into their biological causes, strengthening the

  16. Variability in wood-frame building damage using broad-band synthetic ground motions: a comparative numerical study with recorded motions

    Science.gov (United States)

    Pei, Shiling; van de Lindt, John W.; Hartzell, Stephen; Luco, Nicolas

    2014-01-01

    Earthquake damage to light-frame wood buildings is a major concern for North America because of the volume of this construction type. In order to estimate wood building damage using synthetic ground motions, we need to verify the ability of synthetically generated ground motions to simulate realistic damage for this structure type. Through a calibrated damage potential indicator, four different synthetic ground motion models are compared with the historically recorded ground motions at corresponding sites. We conclude that damage for sites farther from the fault (>20 km) is under-predicted on average and damage at closer sites is sometimes over-predicted.

  17. 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.

  18. Properties of seven Colombian woods

    Science.gov (United States)

    B. A. Bendtsen; M. Chudnoff

    1981-01-01

    Woods from abroad are an important raw material to the forest products industries in the United States. A major concern in effective utilization of this resource is the lack of technical information on many species. This report presents the results of an evaluation of the mechanical properties of small, clear specimens of seven Colombian woods. These results are...

  19. 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...

  20. 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 ...

  1. Effect of environmental conditions on the flexural properties of wood I-beams and lumber

    Science.gov (United States)

    Gwo-Huang Chen; R.C. Tang; E.W. Price

    1989-01-01

    Flexural properties as affected by environmental conditions were evaluated for full-sized wood composite I-beams webbed with oriented strand board (OSB), randomly oriented flakeboard (RF) and 3-ply Structural I plywood (PLY). Solid-sawn southern pine 2 by 10's, ordinarily used in light-frame building construction, were also tested for comparative purposes....

  2. 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 –...

  3. Effect of early age woody and herbaceous competition control on wood properties of loblolly pine

    Science.gov (United States)

    F. Antony; L. R. Schimleck; L. Jordan; Alexander Clark; R. F. Daniels

    2011-01-01

    Early age competition control has been reported to significantly improve the growth and yield of plantation grown loblolly pine. The objective of this paper is to understand the changes in wood properties: basal area weighted whole disk SG, earlywood SG (EWSG), latewood SG (LWSG) and latewood percent (LWP) of 14 year-old trees which received early age herbaceous and...

  4. Fiberboards from loblolly pine refiner groundwood: effects of gross wood characteristics and board density

    Science.gov (United States)

    Charles W. McMillin

    1968-01-01

    Boards for insulation and and structural uses are being manufactured in increasing quantities. The coarse fiber required for these products can be disk-refined from untreated wood chips. Since such fiber is produced in essentially one mechanical operation, continuous control is required of the raw material as well as the refining process.

  5. Effects of host wood moisture on the life cycle development of the Asian longhorned beetle

    Science.gov (United States)

    Alexandra N. Whitney; Melody A. Keena

    2011-01-01

    The Asian longhorned beetle, Anoplophora glabripennis, is an alien invasive species recently introduced to the United States in larval form within solid wood packing material from China. Larvae develop within the xylem of apparently healthy trees. In the U.S., the species has been found infesting 21 species of hardwoods, across 12 genera, with maple...

  6. 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...

  7. 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...

  8. Effect of Fuel wood on the Quality of Smoked Freshwater Fish ...

    African Journals Online (AJOL)

    The study was conducted in Tamale and three villages around it. The method involved processing and smoking some raw freshwater fish species with different fuel wood species to ascertain the quality of the smoked products. A market survey was conducted to match the quality of the smoked products with those sold on the ...

  9. Effects of Eucalyptus globulus Wood Autohydrolysis Conditions on the Reaction Products

    NARCIS (Netherlands)

    Garrote, G.; Kabel, M.A.; Schols, H.A.; Falque, E.; Domingues, H.; Parajo, J.C.

    2007-01-01

    Eucalyptus globulus wood samples were reacted in aqueous media (hydrothermal treatments) at 160 °C for 30¿66 min. Liquors from the several experiments were analyzed by spectrophotometry, high-performance liquid chromatography, or gas chromatography¿mass spectrometry for monosaccharides,

  10. 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)

  11. 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

  12. The effect of changes in lumber and furniture prices on wood furniture manufacturers' lumber usage

    Science.gov (United States)

    William G. Luppold

    1983-01-01

    Wood furniture manufacturers' demands for oak, maple, poplar, open-grain, and close-grain lumber are estimated using cross-sectional, time-series techniques. The analyses indicate that the demand for open-grain species is more price responsive than the demand for close-grain species. The calculated cross-price elasticities indicate that furniture producers do...

  13. 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...

  14. 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 ...

  15. Catalytic effects of eight inorganic additives on pyrolysis of pine wood sawdust by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ming-qiang; Wang, Jun; Zhang, Ming-xu; Chen, Ming-gong; Min, Fan-fei [Department of Chemical and Material Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001 (China); Zhu, Xi-feng [Laboratory of Biomass Clean Energy, University of Science and Technology of China, Hefei 230026 (China); Tan, Zhi-cheng [Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China)

    2008-05-15

    In this paper, pyrolysis of pine wood sawdust was carried out by microwave heating at ca. 470 C under dynamic nitrogen atmosphere. Eight inorganic additives (NaOH, Na{sub 2}CO{sub 3}, Na{sub 2}SiO{sub 3}, NaCl, TiO{sub 2}, HZSM-5, H{sub 3}PO{sub 4}, Fe{sub 2}(SO{sub 4}){sub 3}) were investigated in terms of their catalytic effects on the pyrolysis. All of the eight additives have increased yields of solid products greatly and decreased yields of gaseous products more or less. Yields of liquid products have not subjected to dramatic change. The incondensable gases produced from pyrolysis consist mainly of H{sub 2}, CH{sub 4}, CO and CO{sub 2}. All of the eight additives have made these gases evolve earlier, among which the four sodium additives have the most marked effect. All the additives have made the amount of CH{sub 4} and CO{sub 2} decrease, while all of them except NaCl, TiO{sub 2} and Fe{sub 2}(SO{sub 4}){sub 3} have made that of H{sub 2} increase and all of them except Na{sub 2}SiO{sub 3} and HZSM-5 have made that of CO decrease. Alkaline sodium compounds NaOH, Na{sub 2}CO{sub 3} and Na{sub 2}SiO{sub 3} favor H{sub 2} formation most. The most abundant organic component in the liquid products from pyrolysis of untreated sample and samples treated by all the additives except H{sub 3}PO{sub 4} and Fe{sub 2}(SO{sub 4}){sub 3} is acetol. All the four sodium compounds favor acetol formation reaction and the selection increasing effect follows the order of NaOH > Na{sub 2}CO{sub 3} {approx} Na{sub 2}SiO{sub 3} > NaCl. TiO{sub 2} goes against the formation of acetol, HZSM-5 has no marked effect on acetol formation. The two dominant organic components identified in the liquid products from pyrolysis of H{sub 3}PO{sub 4} and Fe{sub 2}(SO{sub 4}){sub 3} treated samples are both fufural and 4-methyl-2-methoxy-phenol. A possible pathway for acetol formation is tentatively proposed. (author)

  16. Effects of wood chip amendments on the revegetation performance of plant species on eroded marly terrains in a Mediterranean mountainous climate (Southern Alps, France)

    Science.gov (United States)

    Breton, Vincent; Crosaz, Yves; Rey, Freddy

    2016-04-01

    The establishment of plant species can limit soil erosion dynamics in degraded lands. In marly areas in the Southern French Alps, both harsh water erosion and drought conditions in summer due to the Mediterranean mountainous climate prevent the natural implementation and regeneration of vegetation. Soil fertility improvement is sometimes necessary. With the purpose of revegetating such areas, we aimed to evaluate the effects of wood chip amendments on the revegetation performance of different native or sub-spontaneous plant species. We conducted two experiments on steep slopes over three growing seasons (2012-2014). The first consisted of planting seedlings (10 species), and the second consisted of seeding (nine species including six used in the first experiment). First we noted that wood chips were able to remain in place even in steep slope conditions. The planting of seedlings showed both an impact of wood chip amendment and differences between species. A positive effect of wood chips was shown with overall improvement of plant survival (increasing by 11 % on average, by up to 50 % for some species). In the seeding experiment, no plants survived after three growing seasons. However, intermediate results for the first and second years showed a positive effect of wood chips on seedling emergence: seeds of four species only sprouted on wood chips, and for the five other species the average emergence rate increased by 50 %.

  17. Short-term and long-term effects of weed control and fertilization on growth and wood anatomy of a Populus deltoides clone

    Directory of Open Access Journals (Sweden)

    Silvia Estela Monteoliva

    2015-04-01

    Full Text Available Aims of study: The short- and long-term effects of weed control and fertilization on growth and wood anatomy of 10-y-old Populus deltoides were investigated. Weed control and fertilization usually leads to an increase the growth rate of trees, and consequently, a possible modification in the quality of produced wood. Area of study: We analyzed trees from an experimental plantation in Buenos Aires, Argentina (34° 50’ S Lat; 60° 30’ W Long. Methods: 32 trees from three treatments: mechanical weed control (M, chemical and mechanical weed control (CHM and fertilized plus chemical and mechanical weed control (CHM-F were analyzed. Basal area, fibre morphology, cell wall area and vessel size were measured in the growth ring 1, 3 and 10. Results: differences on wood anatomy among treatments were mainly observed at the third year (short-term effect. Long-term negative effects were not observed. Fertilized trees had greater proportion and quality of wood closer to pith. Research highlights: fibre and vessel differences seen in CHM and CHM-F compared to controls in year 3 could be interpreted as evidence of maturation in cambial development (thicker, longer and wider fibres and greater vessels. The CHM-F treatment had a greater proportion of wood that showed characteristics of more mature wood.

  18. Effects of the synoptic scale variability on the thermohaline circulation

    Directory of Open Access Journals (Sweden)

    J. J. Taboada

    2005-01-01

    Full Text Available In this paper the effect of the synoptic scale variability is analyzed using a simple atmosphere-ocean coupled model. This high frequency variability has been taken into account in the model adding white gaussian noise in variables related to zonal and meridional temperature differences. Results show that synoptic scale frequency variability on longitudinal heating contrast between land and sea can produce a collapse of thermohaline circulation when a threshold of noise is overcome. This result is significant because if synoptic scale variability in the next century increases due to the climatic change an increment of the probability of this collapse could be produced.

  19. Using Instrumental Variables Properly to Account for Selection Effects

    Science.gov (United States)

    Porter, Stephen R.

    2012-01-01

    Selection bias is problematic when evaluating the effects of postsecondary interventions on college students, and can lead to biased estimates of program effects. While instrumental variables can be used to account for endogeneity due to self-selection, current practice requires that all five assumptions of instrumental variables be met in order…

  20. Wood Availability

    NARCIS (Netherlands)

    Schelhaas, M.; Layos Mayr, Marian

    2017-01-01

    Estimation of the amount of wood that could potentially be harvested in a country can be accomplished using several approaches. A simple indicator is the balance between annual fellings and Net Annual Increment. However, this indicator does not take into account the actual age-class distribution of

  1. Effect of hydrothermal pretreatment on properties of bio-oil produced from fast pyrolysis of eucalyptus wood in a fluidized bed reactor.

    Science.gov (United States)

    Chang, Sheng; Zhao, Zengli; Zheng, Anqing; Li, Xiaoming; Wang, Xiaobo; Huang, Zhen; He, Fang; Li, Haibin

    2013-06-01

    Eucalyptus wood powder was first subjected to hydrothermal pretreatment in a high-pressure reactor at 160-190°C, and subsequently fast pyrolyzed in a fluidized bed reactor at 500°C to obtain high quality bio-oil. This study focused on investigating effect of hydrothermal pretreatment on bio-oil properties. Hemicellulose and some metals were effectively removed from eucalyptus wood, while cellulose content was enhanced. No significant charring and carbonization of constituents was observed during hydrothermal pretreatment. Thus pretreated eucalyptus wood gave higher bio-oil yield than original eucalyptus wood. Chemical composition of bio-oil was examined by GC/MS and (13)C NMR analyses. Bio-oil produced from pretreated eucalyptus wood exhibited lower contents of ketones and acids, while much higher levoglucosan content than bio-oil produced from original eucalyptus wood, which would help to improve thermal stability of bio-oil and extract levoglucosan from bio-oil. Hydrothermal pretreatment also improved bio-oil fuel quality through lowering water content and enhancing heating value. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. 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.

  3. 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.

  4. Extracting value from Eucalyptus wood before kraft pulping: effects of hemicelluloses solubilization on pulp properties.

    Science.gov (United States)

    Vila, C; Romero, J; Francisco, J L; Garrote, G; Parajó, J C

    2011-04-01

    Eucalyptus globulus wood samples were subjected to autohydrolysis for extracting hemicelluloses, and the resulting solids were assayed as substrates for kraft pulping and further Totally Chlorine Free (TCF) bleaching. The susceptibility of treated solids to kraft processing was assessed under selected experiments covering the optimum experimental range. In order to establish a basis for comparison, samples of untreated wood were also subjected to kraft delignification. The best kraft pulps obtained from autohydrolyzed solids were subjected to an optimized TCF bleaching sequence involving double alkaline oxygen and pressurized H(2)O(2) processing, and characterized using standard methods. The suitability of the final product obtained by autohydrolysis-kraft delignification-TCF bleaching for specific purposes is discussed on the basis of the experimental results. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Effect of steam treatment on the properties of wood cell walls.

    Science.gov (United States)

    Yin, Yafang; Berglund, Lars; Salmén, Lennart

    2011-01-10

    Steam treatment is a hygrothermal method of potential industrial significance for improving the dimensional stability and durability of wood materials. The steaming results in different chemical and micromechanical changes in the nanostructured biocomposite that comprise a wood cell wall. In this study, spruce wood ( Picea abies Karst.) that had been subjected to high-temperature steaming up to 180 °C was examined, using imaging Fourier Transform Infrared (FT-IR) microscopy and nanoindentation to track changes in the chemical structure and the micromechanical properties of the secondary cell wall. Similar changes in the chemical components, due to the steam treatment, were found in earlywood and latewood. A progressive degradation of the carbonyl groups in the glucuronic acid unit of xylan and a loss of mannose units in the glucomannan backbone, that is, a degradation of glucomannan, together with a loss of the C═O group linked to the aromatic skeleton in lignin, was found. The development of the hygroscopic and micromechanical properties that occurred with an elevation in the steam temperature correlated well with this pattern of degradation in the constituents in the biocomposite matrix in the cell wall (hemicellulose and lignin).

  6. Effect of Filler Loading on Mechanical and Tribological Properties of Wood Apple Shell Reinforced Epoxy Composite

    Directory of Open Access Journals (Sweden)

    Ojha Shakuntala

    2014-01-01

    Full Text Available During the last century, natural fibers and particulates are used as reinforcement in polymer composite that has been continuously growing in the composite industry. This polymer matrix composite has wide range of applications in hostile environment where they are exposed to external attacks such as solid particle erosion. Also, the mechanical properties of different polymer composites show the best alternate to replace the metal material. In the present investigation, an attempt has been made to improve the mechanical and tribological behaviour of polymer matrix composite using wood apple shell particles as a filler material in polymer matrix. Also the temperature variation of the dynamic-mechanical parameters of epoxy matrix composites incorporated with 5, 10, 15, and 20 wt% of wood apple shell particles was investigated by DMA test. It is clearly observed that the incorporation of wood apple shell particles tends to increase the tensile strength, flexural strength, erosive wear resistance, and viscoelastic stiffness of the polymer composite. To validate the results, SEM of the polymer matrix composite has been studied.

  7. 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...

  8. 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...

  9. Effect of PF impregnation and surface densification on the mechanical properties of small-scale wood laminated poles

    Science.gov (United States)

    Huaqiang Yu; Chung Y. Hse; Zehui Jiang

    2009-01-01

    The wood poles in the United States are from high-valued trees that are becoming more expensive and less available. Wood laminated composite poles (LCP) are a kind of alternative to solid poles. Considerable interest has developed in last century in the resin impregnation and wood surface densification to improve its physical and mechanical properties. In this...

  10. 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....

  11. EVALUATION OF THE EFFECTIVENESS OF COATINGS IN REDUCING DISLODGEABLE ARSENIC, CHROMIUM, AND COPPER FROM CCA TREATED WOOD, INTERIM DATA REPORT

    Science.gov (United States)

    EPA is approximately 20 months into a project to evaluate the performance of wood coatings as a way to prevent arsenic, chromium and copper exposure from the surfaces of CCA treated wood. Potential dermal exposure, as measured by wipe sampling dislodgeable CCA chemical from wood ...

  12. 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.

  13. 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.

  14. The effect of personal and socio- conomic variables on the ...

    African Journals Online (AJOL)

    The effect of personal and socio- conomic variables on the knowledge, attitude and belief of farm workers about HIV/AIDS, two case studies – a lesson for extension. ... The influence of the socio-economic variables before the Intervention Program indicated that females had a better knowledge and a more positive attitude ...

  15. 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 ...

  16. Effects of interannual climate variability on tropical tree cover

    Science.gov (United States)

    Holmgren, Milena; Hirota, Marina; van Nes, Egbert H.; Scheffer, Marten

    2013-08-01

    Climatic warming is substantially intensifying the global water cycle and is projected to increase rainfall variability. 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 rainfall can have neutral or even positive effects on tree cover in the dry tropics. In South America, tree cover in dry lands is higher in areas with high year-to-year variability in rainfall. This is consistent with evidence from case studies suggesting that in these areas rare wet episodes are essential for opening windows of opportunity where massive tree recruitment can overwhelm disturbance effects, allowing the establishment of extensive woodlands. In Australia, wet extremes have similar effects, but the net effect of rainfall variability is overwhelmed by negative effects of extreme dry years. In Africa, effects of rainfall variability are neutral for dry lands. It is most likely that differences in herbivore communities and fire regimes contribute to regulating tree expansion during wet extremes. Our results illustrate that increasing climatic variability may affect ecosystem services in contrasting, and sometimes surprising, ways. Expansion of dry tropical tree cover during extreme wet events may decrease grassland productivity but enhance carbon sequestration, soil nutrient retention and biodiversity.

  17. 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.

  18. 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...... hydrolysis are compared. The effects of temperature, acid concentration, composition of organic phase (for sulfuric acid), and pressure (for nitric acid) on the effectiveness of pretreatment were analyzed. It is shown that the use of organosolv with 0.5% sulfuric acid allows us to increase the reactivity...... of ground wood by 300–400%, compared to the initial raw material. Pretreatment with a 4.8% aqueous solution of nitric acid (125°C, 1.8 MPa, 10 min) is shown to be most effective, as it increases the reactivity of the ground aspen wood by more than 500%....

  19. 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.

  20. Effect of biochar on mechanical and flame retardant properties of wood – Plastic composites

    Directory of Open Access Journals (Sweden)

    Qingfa Zhang

    Full Text Available Biochar/wood/plastic composites were prepared with different biochar content by the extrusion method, and the mechanical properties and flame retardant properties were tested. The study indicated that: with the increase of biochar content, the mechanical properties of the composites tended to rise at first and then fell. This suggested that the appropriate amount of biochar can promote the mechanical properties of the biochar/wood/plastic composites. Though both Mg(OH2 and Al(OH3 could improve the Flame retardant properties of the material evidently, Mg(OH2 obtained a better effect than Al(OH3. In particular, when the adding amount of Mg(OH2 is 40 wt%, the flame retardant effect is the best. Al(OH3 can reduce the mechanical properties of the material, while Mg(OH2 could evidently promote the tensile strength and impact resistance strength of the material. Keywords: Biochar, Composites, Mechanical properties, Flame retardant properties

  1. Effects of oat hulls and wood shavings on digestion in broilers and layers fed diets based on whole or ground wheat.

    Science.gov (United States)

    Hetland, H; Svihus, B; Krogdahl, A

    2003-05-01

    1. An experiment was conducted to study the effects of inclusion of oat hulls in diets based on whole or ground wheat for broilers. Effects of wood shavings on layers were investigated in a further experiment. 2. Inclusion of oat hulls in wheat-based broiler diets did not affect weight gain. Feed conversion efficiency (FCE), corrected for insoluble fibre contents, was improved by oat hull inclusion. 3. Gizzard size increased with inclusion of oat hulls, whole wheat, wood shavings and grit. 4. Starch digestibility was significantly increased by inclusion of oat hulls for broilers, and by wood shavings for layers. 5. Wood shavings and whole wheat did not affect bile acid concentration of gizzard contents. However, the total amount of bile acids in gizzard increased with access to wood shavings due to an increase in the weight of gizzard contents, indicating an increased gastroduodenal reflux. 6. Fibre concentration was considerably higher in the gizzard contents than in the feed. 7. Duodenal particle size decreased with access to grit. No effect of hulls or whole wheat inclusion was found, indicating that all particles are ground to a certain critical size before leaving the gizzard.

  2. THE EFFECTS OF SEASONAL CHANGES ON THE COMBUSTION DURATION OF THE CEDAR (Cedrus libani A. Rich. AND ORIENTAL SPRUCE (Picea Orientalis Lipsky WOOD SAMPLES

    Directory of Open Access Journals (Sweden)

    Muhammed Said Fidan

    2016-12-01

    Full Text Available In this study, the effects of the wood’s combustion properties on the combustion duration are investigated towards the protection of the wood samples from the effects of outdoor by using various impregnation and high-level processes. For that purpose, in accordance with the given principles on the standard of combustion test ASTM–E 160-50 test samples from cedar (Cedrus libani A.Rich. and spruce (Picea orientalis L. are impregnated with tanalith-E and wolmanit-CB impregnation materials then water based and synthetic outdoor varnishes are applied as a high level process, afterwards seasonal effects on outdoor conditions are analysed. According to the obtained findings, first failure time for spruce wood samples the peak is 457 seconds in winter and the minimum is 257 seconds in fall, for cedar wood samples the top time is 479 seconds and the minimum time is 326 seconds in winter samples. In all combustion durations, top time at spruce wood samples is 2105 seconds at control examples and minimum time is 1143 seconds in summer samples. For cedar wood samples the top time confirmed is 2707 seconds in fall samples and minimum time is 1338 seconds in summer examples.

  3. Effectiveness of Polyacrylamide, Wood Shred Mulch, and Pine Needle Mulch as Post-Fire Hillslope Stabilization Treatments in Two Contrasting Volcanic Soils

    Directory of Open Access Journals (Sweden)

    Jonay Neris

    2017-07-01

    Full Text Available Post-fire hillslope stabilization treatments aim to reduce runoff-erosion risks following forest fires by counteracting the impact of fire on key soil and hillslope properties. Here we evaluate the effectiveness of wood shred mulch, long-leaved pine needle mulch, and polyacrylamide (PAM in reducing post-fire runoff and erosion in two volcanic soil types of contrasting wettability using rainfall simulations (55 mm h−1 for 30 min at the microplot (0.25 m2 scale. The cover provided by the wood shreds and pine needles led to a reduction of runoff and erosion in both the wettable—(62% and 92%, respectively, for wood shreds, and 55% and 87%, respectively, for needle mulch and the extremely water-repellent soils (44% and 61%, respectively, for wood shreds. In contrast to what might be expected, PAM did not reduce runoff or erosion when applied to the extremely water-repellent soils, suggesting that PAM should not be applied in this terrain type. Although more research is needed to determine whether the high effectiveness of pine needle mulch and wood shred mulch fully translates to coarser scales, the results are encouraging in terms of these materials’ ability to provide effective and relatively economic mitigation treatments for fire-induced runoff-erosion risks in volcanic soils.

  4. The influence of the raw material on the wood product manufacturing

    OpenAIRE

    Salim, Roaa; Johansson, Jimmy

    2016-01-01

    This paper focuses on the later part of the wood processing chain in wood industry: the wood product manufacturing. Wood product manufacturers are facing many challenges e.g. due to the high variability of the raw material. Waste and rework are prevalent, resulting in high manufacturing costs. Each processing step in the manufacturing affects material utilization and cost efficiency. The proportion of the material cost and waste in most wood products are high. The challenge for wood product m...

  5. 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.

  6. Response variables for evaluation of the effectiveness of conservation corridors.

    Science.gov (United States)

    Gregory, Andrew J; Beier, Paul

    2014-06-01

    Many studies have evaluated effectiveness of corridors by measuring species presence in and movement through small structural corridors. However, few studies have assessed whether these response variables are adequate for assessing whether the conservation goals of the corridors have been achieved or considered the costs or lag times involved in measuring the response variables. We examined 4 response variables-presence of the focal species in the corridor, interpatch movement via the corridor, gene flow, and patch occupancy--with respect to 3 criteria--relevance to conservation goals, lag time (fewest generations at which a positive response to the corridor might be evident with a particular variable), and the cost of a study when applying a particular variable. The presence variable had the least relevance to conservation goals, no lag time advantage compared with interpatch movement, and only a moderate cost advantage over interpatch movement or gene flow. Movement of individual animals between patches was the most appropriate response variable for a corridor intended to provide seasonal migration, but it was not an appropriate response variable for corridor dwellers, and for passage species it was only moderately relevant to the goals of gene flow, demographic rescue, and recolonization. Response variables related to gene flow provided a good trade-off among cost, relevance to conservation goals, and lag time. Nonetheless, the lag time of 10-20 generations means that evaluation of conservation corridors cannot occur until a few decades after a corridor has been established. Response variables related to occupancy were most relevant to conservation goals, but the lag time and costs to detect corridor effects on occupancy were much greater than the lag time and costs to detect corridor effects on gene flow. © 2014 Society for Conservation Biology.

  7. 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. 

  8. 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)

  9. EFFECT OF Eucalyptus grandis WOOD REFINING ON THE FIBER MORFHOLOGY AND ON MDF PANELS PROPERTIES

    Directory of Open Access Journals (Sweden)

    Ugo Leandro Belini

    2008-09-01

    Full Text Available The utilization of eucalypts wood for MDF panels producing is recent in Brazil and presents larger perspective of increase, in relationship to pine wood, due to the shorter harvesting cycle and integral use of the bark in the productive process, etc,. The present work evaluated the anatomical structure and properties of MDF panels manufactured at laboratory with Eucalyptus grandis fibers obtained in three treatments. It were evaluated the variations in heating time, digester and refining pressure and specific energy. MDF panels obtained in critical refining condition showed darker fibers and cell walls transversely broken and lower resistance to internal bond, surface soundness, withdrawal of screws and swelling in thickness. MDF panels obtained after less intensive refining condition showed better physical properties. Better refining conditions increase the bulk density and hinder the adhesive recover and fiber interlace, with worse physical and mechanics properties. Fiber morphology was evaluated through stereoscope and scanning electronic microscopic (SEM, establishing relationships between chips refining treatments and MDF panels properties.

  10. Exploring sub-lethal effects of exposure to a nucleopolyhedrovirus in the speckled wood (Pararge aegeria) butterfly.

    Science.gov (United States)

    Hesketh, Helen; Gibbs, Melanie; Breuker, Casper J; Van Dyck, Hans; Turner, Emma; Hails, Rosemary S

    2012-01-01

    This study investigated the sub-lethal effects of larval exposure to baculovirus on host life history and wing morphological traits using a model system, the speckled wood butterfly Pararge aegeria (L.) and the virus Autographa californica nucleopolyhedrovirus. Males and females showed similar responses to the viral infection. Infection significantly reduced larval growth rate, whilst an increase in development time allowed the critical mass for pupation to be attained. There was no direct effect of viral infection on the wing morphological traits examined. There was, however, an indirect effect of resisting infection; larvae that took longer to develop had reduced resource investment in adult flight muscle mass. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  11. The Effect of Ultrafine Magnesium Hydroxide on the Tensile Properties and Flame Retardancy of Wood Plastic Composites

    Directory of Open Access Journals (Sweden)

    Zhiping Wu

    2014-01-01

    Full Text Available The effect of ultrafine magnesium hydroxide (UMH and ordinary magnesium hydroxide (OMH on the tensile properties and flame retardancy of wood plastic composites (WPC were investigated by tensile test, oxygen index tester, cone calorimeter test, and thermogravimetric analysis. The results showed that ultrafine magnesium hydroxide possesses strengthening and toughening effect of WPC. Scanning electron micrograph (SEM of fracture section of samples provided the positive evidence that the tensile properties of UMH/WPC are superior to that of WPC and OMH/WPC. The limited oxygen index (LOI and cone calorimeter test illustrated that ultrafine magnesium hydroxide has stronger flame retardancy and smoke suppression effect of WPC compared to that of ordinary magnesium hydroxide. The results of thermogravimetric analysis implied that ultrafine magnesium hydroxide can improve the char structure which plays an important role in reducing the degradation speed of the inner matrix during combustion process and increases the char residue at high temperature.

  12. 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.

  13. 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...... ceramic material can be achieved, thus suggesting new industrial applications. The structure and composition of numerous as-synthesized samples were characterized in detail by using a wide range of techniques. Wear and friction properties were also investigated, with polished samples. The properties found...

  14. Wood Scrap Project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Beachy, D.

    1983-01-01

    This study investigated Utah's sawmill residue, logging residue and pinyon-juniper resource for use as an energy resource to replace supplement conventional fuels now in use. This was accomplished by analyzing existing and future supplies of wood suitable for energy use on a renewable basis and the cost effectiveness of using wood as compared to coal, natural gas, and propane. The promotion of the use and development of wood as a renewable resource to reduce Utah's dependency for selected residential, institutional, commercial, and industrial markets for conventional non-renewable forms of energy is also considered. 84 references, 21 figures, 32 tables.

  15. 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.

  16. Small-angle x-ray scattering investigation of the effect of heating temperature on the submicroscopic pore structure of wood charcoal

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, P.W.; Cutter, B.E.; Kalliat, M.

    1984-04-01

    In order to learn about the effects of higher preparation temperatures, we recently examined a series of charcoals from black cherry (Prunus serotina Ehrh.) wood heated to temperatures from 600/sup 0/ to 2000/sup 0/C. The results are summarized in this report. In addition to obtaining some information about the pore structure of black cherry charcoal, we have developed a general picture of how the charcoal porosity depends on the temperature to which the wood was heated during pyrolysis. These results have led us to propose that the macropores in charcoals are similar to those in wood and that the main effect which pyrolysis at temperatures above 400/sup 0/C exerts on the pore structure is to cause the micropores and transitional pores to grow, while leaving the macropores almost unchanged.

  17. The effects of biographical variables on job satisfaction among nurses.

    Science.gov (United States)

    Curtis, Elizabeth A

    A review of the literature confirms that there is no clear picture with regard to which biographical variables are strongly correlated with job satisfaction. Studies have shown small and inconsistent effects on variables, such as age, gender, education and personality, on job satisfaction. This study aimed to determine the effect of biographical variables on job satisfaction among nurses. The study used a dominant-less dominant mixed-method design and quantitative data were collected by a postal questionnaire survey. The sample was selected using stratified random sampling. The findings demonstrated no significant differences in job satisfaction for female and male nurses, and between job satisfaction and tenure. The findings did, however, confirm that nurses under the age of 35 were less satisfied than those over the age of 36; nurses with degrees were less satisfied than those without; and nurses in senior positions are more satisfied than their junior counterparts. The findings should be interpreted with caution because of the sample size and the small correlations between variables. Limitations aside, this study provides an insight into the relationship between these variables among nurses in the Republic of Ireland. It is possible that biographical variables are distal influences on job satisfaction, but further research is needed to better understand the relationship between these two sets of variables.

  18. 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.

  19. Extrusion pretreatment of pine wood chips.

    Science.gov (United States)

    Karunanithy, C; Muthukumarappan, K; Gibbons, W R

    2012-05-01

    Pretreatment is the first step to open up lignocellulose structure in the conversion of biomass to biofuels. Extrusion can be a viable pretreatment method due to its ability to simultaneously expose biomass to a range of disruptive conditions in a continuous flow process. Extruder screw speed, barrel temperature, and feedstock moisture content are important factors that can influence sugar recovery from biomass. Hence, the current study was undertaken to investigate the effects of these parameters on extrusion pretreatment of pine wood chips. Pine wood chip at 25, 35, and 45 % wb moisture content were pretreated at various barrel temperatures (100, 140, and 180 °C) and screw speeds (100, 150, and 200 rpm) using a screw with compression ratios of 3:1. The pretreated pine wood chips were subjected to standard enzymatic hydrolysis followed by sugar and byproducts quantification. Statistical analyses revealed the existence of significant differences in sugar recovery due to independent variables based on comparing the mean of main effects and interaction effects. Pine wood chips pretreated at a screw speed of 150 rpm and a barrel temperature of 180 °C with a moisture content of 25 % resulted in a maximum cellulose, hemicellulose, and total sugar recoveries of 65.8, 65.6, and 66.1 %, respectively, which was about 6.7, 7.9, and 6.8 fold higher than the control (unpretreated pine chips). Furthermore, potential fermentation inhibitors such as furfural, hydroxyl methyl furfural, and acetic acid were not found in any of the treatment combinations.

  20. Assessing the impact of a wood stove replacement program on air quality and children's health.

    Science.gov (United States)

    Noonan, Curtis W; Ward, Tony J; Navidi, William; Sheppard, Lianne; Bergauff, Megan; Palmer, Chris

    2011-12-01

    Many rural mountain valley communities experience elevated ambient levels of fine particulate matter (PM*) in the winter, because of contributions from residential wood-burning appliances and sustained temperature inversion periods during the cold season. A wood stove change-out program was implemented in a community heavily affected by wood-smoke-derived PM2.5 (PM < or = 2.5 microm in aerodynamic diameter). The objectives of this study were to evaluate the impact of this intervention program on ambient and indoor PM2.5 concentrations and to identify possible corresponding changes in the frequency of childhood respiratory symptoms and infections and illness-related school absences. Over 1100 old wood stoves were replaced with new EPA-certified wood stoves or other heating sources. Ambient PM2.5 concentrations were 30% lower in the winter after the changeout program, compared with baseline winters, which brought the community's ambient air within the PM2.5 standards of the U.S. Environmental Protection Agency (U.S. EPA). The installation of a new wood stove resulted in an overall reduction in indoor PM2.5 concentrations in a small sample of wood-burning homes, but the effects were highly variable across homes. Community-level reductions in wood-smoke-derived PM2.5 concentration were associated with decreased reports of childhood wheeze and of other childhood respiratory health conditions. The association was not limited to children living in homes with wood stoves nor does it appear to be limited to susceptible children (e.g., children with asthma). Community-level reductions in wood-smoke-derived PM2.5 concentration were also associated with lower illness-related school absences among older children, but this finding was not consistent across all age-groups. This community-level intervention provided a unique opportunity to prospectively observe exposure and outcome changes resulting from a targeted air pollution reduction strategy.

  1. Effects of Modifier Type on Properties of in Situ Organo-Montmorillonite Modified Wood Flour/Poly(lactic acid) Composites.

    Science.gov (United States)

    Liu, Ru; Chen, Yu; Cao, Jinzhen

    2016-01-13

    Wood flour (WF) was modified with sodium-montmorillonite (Na-MMT) and two types of surfactant modifiers, namely, didecyl dimethylammonium chloride (DDAC) and sodium dodecyl sulfonate (SDS) though a two-step process inside WF. The thus-modified WFs were characterized, and the effects of MMT type on physical, mechanical, and thermal properties of their composites with poly(lactic acid) (PLA) were investigated. The results showed: (1) either DDAC or SDS could modified Na-MMT into OMMT, and then uniformly distributed in WF cell walls; (2) OMMT improved the physical properties, most mechanical properties, and thermal properties of the composites except for the impact strength; and (3) compared with SDS, DDAC seemed to perform better in properties of composites. However, DDAC showed some negative effect on the early stage of composite thermal decomposition.

  2. Studying and Assessment of the Effective Criteria on Opportunities Attainment from Offshore Outsourcing in Iran Wood Furniture Industry

    Directory of Open Access Journals (Sweden)

    nemat allah mohebbi

    2015-11-01

    Full Text Available Nowadays, many of developing countries are looking for outsourcing opportunities of developed countries, because this will bring them many benefits. In this regard, the goal of this study is determining and prioritizing of the effective criteria on attainment of outsourcing benefits of the developed countries in wood furniture industry by non-parametric approach of analytic hierarchy process as one of the most creditable multi-criteria decisionmaking methods. For this purpose, after comparative studies and interview with relevant experts, the effective criteria were identified. After design of analytic hierarchy levels of decision making tree, the necessary data for prioriting provided by standard questionnaire based on paired comparisons and finally the computational steps was done by Expert Choice software. Base on the obtained results, currency exchange rate, economical stability, inflation rate, labor cost, cost of raw material, technological software and hardware of furniture industry, skillfull manpower and developed lateral industries, have the highest priorities.

  3. 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...

  4. 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.

  5. EFFECTS OF BELT SPEED, PRESSURE AND GRIT SIZE ON THE SANDING OF Pinus elliottii WOOD

    Directory of Open Access Journals (Sweden)

    Manoel Cléber de Sampaio Alves

    2015-03-01

    Full Text Available The present paper aims to evaluate the influence of the factors (belt speed, pressure and grit size on the output parameters (temperature and surface roughness for Pinus elliottii wood sanding, processed parallel to the fibers. Three levels of belt speed, three levels of pressure and four levels of grit size were employed, with six replicates for each process, totaling 216 observations. The experiment conducted under a randomized complete block design (RCBD. The results were analyzed employing the analysis of variance (ANOVA with 5% of significance level. Only grit sizes were significant to different temperature levels. The same outcome was observed for roughness, where only grits sizes were significant. No interaction between the pressure and belt speed factors were observed for all the results analyzed.

  6. The effect of kaolin and peat ash on the combustion of demolition wood under well controlled conditions

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Roger A.; Todorovic, Dusan; Skreiberg, Oeyvind; Backman, Rainer; Goile, Franziska; Skreiberg, Alexandra; Soerum, Lars

    2010-07-01

    Full text: In an attempt to look at means for corrosion reduction in boilers, combustion experiments were performed on demolition wood with kaolin and peat ash as additive. The fuel was reduced in size by grinding and mixed with kaolin prior to pelletization. The combustion experiments were performed in a multi-fuel reactor with continuous feed of the pellets by applying staged air combustion. In general a good control over parameters that influence the combustion process in terms of fuel and air supply and reactor temperature was obtained. In addition, the gas concentration and the particle distribution in the flue gas was monitored. A total characterization of the elemental composition of the fuel, the bottom ash and some particle size stages of fly ash was also performed. This was done in order to follow the fate of some of the problematic compounds in demolition wood as a function of kaolin and peat ash addition and other combustion related parameters. In particular chlorine and potassium distribution between the gas phase, the bottom ash and the fly ash is reported as a function of increased additive addition, reactor temperature and air staging. Kaolin addition of 5 and 10 % were found to give the least aerosol load in the fly ash. In addition, the chlorine concentration in aerosol particles was at its lowest levels for the same addition of kaolin, although the difference between 5 and 10 % addition was minimal. The reactor temperature was found to have a minimal effect on both the fly ash and bottom ash properties. Leaner oxygen conditions on the combustion grate was also found to produce less particle load and aerosols with less chlorine content. The results of adding 1-10 % peat ash to the demolition wood show that the concentrations of zinc and lead are very high in the fly ash samples. A considerable part of these metals are chemically bound to chlorides and sulfates together with potassium and sodium indicating extensive volatilization of both zinc and

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. EFFECTS OF SHEEP TREADING ON PLANT COVERING AND SOIL ORIBATIDA (ACARI IN A WOODED HAY MEADOW IN SOGN (NORWAY

    Directory of Open Access Journals (Sweden)

    STANISŁAW SENICZAK

    2008-05-01

    Full Text Available Effects of sheep treading on plant covering and soil oribatid mites in a traditionally maintained wooded hay meadow in Sogn (Norway were investigated. Samples were taken under the elm trees in 2 zones, situated 1m from the elm trunks, heavily treaded by sheep, and 5m from these trunks. The sheep treading decreased the plant covering, especially mosses, and the density of Oribatida, but increased the participation of their juvenile stages. The Oribatida occupied mainly the upper soil layer and the density distinctly decreased with the soil depth, but the sheep treading appeased the differences of density of mites in soil layers, comparing to the zone situated 5m from the elm trunks.

  12. Age-dependent radial increases in wood specific gravity of tropical pioneers in Costa Rica

    Science.gov (United States)

    Bruce G. Williamson; Michael C. Wiemann

    2010-01-01

    Wood specific gravity is the single best descriptor of wood functional properties and tree life-history traits, and it is the most important variable in estimating carbon stocks in forests. Tropical pioneer trees produce wood of increasing specific gravity across the trunk radius as they grow in stature. Here, we tested whether radial increases in wood specific gravity...

  13. 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/...

  14. 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...

  15. 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...

  16. Effect of adhesive applied to the tooth-wood interface on metal-plate connections loaded in tension

    Science.gov (United States)

    Leslie H. Groom

    1991-01-01

    The structural behavior of metal-plate connections (MPCs) is affected not only by the isolated properties of the adjoining wood members and metal plate but also by the interfacial region between individual teeth and the surrounding wood. This study looked at maintaining a good interface by applying an epoxy adhesive to metal-plate teeth immediately preceding joint...

  17. 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...

  18. 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.

  19. Causes of Variability in the Effects of Vegetative Ash on Post-Fire Runoff and Erosion

    Science.gov (United States)

    Balfour, V.; Woods, S.

    2008-12-01

    Vegetative ash formed during forest wildfires has varying effects on post-fire runoff and erosion. In some cases the ash layer reduces runoff and erosion by storing rainfall and by protecting the soil surface from surface sealing and rainsplash detachment. In other cases, the ash layer increases runoff and erosion by forming a surface crust, clogging soil pores, and providing a ready source of highly erodible fine material. Since only a handful of studies have measured the hydrogeomorphic effect of ash, it is unclear whether the observed variability in its effect reflects initial spatial variability in the ash properties due to factors such as fuel type and fire severity, or differences that develop over time due to compaction and erosion or exposure of the ash to rainfall and air. The goal of our research was to determine if the observed differences in the effect of ash on runoff and erosion are due to: 1) variability in initial ash hydrologic properties due to differences in combustion temperature and fuel type, or 2) variability in ash hydrologic properties caused by mineralogical phase changes that develop after the ash is exposed to water. We created ash in the laboratory using wood and needles of Lodgepole pine (Pinus contorta), Ponderosa pine (Pinus Ponderosa) and Douglas fir (Pseudotsuga menziesii) and at 100° C temperature increments from 300 to 900° C. A subsample of ash from each fuel type / temperature combination was saturated, left undisturbed for 24 hours and then oven dried at 104° C. Dry and wetted ash samples were characterized in terms of: structure (using a scanning electron microscope), carbon content, mineralogy (using X-ray diffraction), porosity, water retention properties and hydraulic conductivity. Ash produced at the higher combustion temperatures from all three fuel types contained lime (CaO), which on wetting was transformed to portlandite (Ca(OH)2) and calcite (CaCO3). This mineralogical transformation resulted in irreversible

  20. A new methodology for monitoring wood fluxes in rivers using a ground camera: Potential and limits

    Science.gov (United States)

    Benacchio, Véronique; Piégay, Hervé; Buffin-Bélanger, Thomas; Vaudor, Lise

    2017-02-01

    Ground imagery, which produces large amounts of valuable data at high frequencies, is increasingly used by fluvial geomorphologists to survey and understand processes. While such technology provides immense quantities of information, it can be challenging to analyze and requires automatization and associated development of new methodologies. This paper presents a new approach to automate the processing of image analysis to monitor wood delivery from the upstream Rhône River (France). The Génissiat dam is used as an observation window; all pieces of wood coming from the catchment are trapped here, hence a wood raft accumulates over time. In 2011, we installed an Axis 211W camera to acquire oblique images of the reservoir every 10 min with the goal of automatically detecting a wood raft area, in order to transform it to wood weight (t) and flux (t/d). The methodology we developed is based on random forest classification to detect the wood raft surface over time, which provided a good classification rate of 97.2%. Based on 14 mechanical wood extractions that included weight of wood removed each time, conducted during the survey period, we established a relationship between wood weight and wood raft surface area observed just before the extraction (R2 = 0.93). We found that using such techniques to continuously monitor wood flux is difficult because the raft undergoes very significant changes through time in terms of density, with a very high interday and intraday variability. Misclassifications caused by changes in weather conditions can be mitigated as well as errors from variation in pixel resolution (owing to camera position or window size), but a set of effects on raft density and mobility must still be explored (e.g., dam operation effects, wind on the reservoir surface). At this stage, only peak flow contribution to wood delivery can be well calculated, but determining an accurate, continuous series of wood flux is not possible. Several recommendations are

  1. 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...

  2. Effect of Some Environmental Variables on the Community Structure ...

    African Journals Online (AJOL)

    Water samples and zooplankton were collected monthly for five months in three sites in Wushishi Dam, Niger State. The study was undertaken to look at effect of some environmental variables on zooplankton community in the dam. Dissolved oxygen (DO) was highest in site 1 with mean value of 2.60±0.248 mg/l. There was ...

  3. 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 ...

  4. Effects of physical variables on settling velocities of calcium and ...

    African Journals Online (AJOL)

    Settling velocity is an important parameter used in modeling solid-liquid flow operations and for evaluating tank volumes in water treatment technology. In the present study, series of bench-scale batch-wise precipitation and settling tests were performed to evaluate the effect of some physical variables such as precipitate ...

  5. Effects of experimental variables on the degree of epoxidation of ...

    African Journals Online (AJOL)

    The effects of experimental variables such as temperature, time, type of solvent and nature of the clay-supported hydrogen peroxide on the degree of epoxidation of cashew nut shell liquid (CNSL) and cashew nut oil (CNO) were investigated by iodine value measurements. Results show that the acid treatment of the ...

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

    African Journals Online (AJOL)

    DR OKE

    porous medium, Physics Letters A, Vol. 372, 14, pp 2355-2358. Jayanthi S. and Kumari M., 2007. Effect of variable viscosity on non-Darcy free or mixed convection flow on a vertical surface in a fluid saturated porous medium, Applied Mathematics and Computations, Vol.186, 2, pp 1643-1659. Kafoussius N.G. and Williams ...

  7. 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 ...

  8. Phenotypic effects of genetic variability in human clock genes on ...

    Indian Academy of Sciences (India)

    Several mouse models of clock gene null alleles have been demonstrated to have affected sleep homeostasis. Recent findings have shown that the variable number tandem polymorphism in PER3, previously linked to diurnal preference, has profound effects on sleep homeostasis and cognitive performance following sleep ...

  9. Effects of wood ash on the biologic diversity of the soil fauna. Final report; Effekter av vedaska paa biologisk maangfald hos markfaunan. Slutrapport

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tryggve; Ahlstroem, Kerstin; Lindberg, Niklas [Swedish Univ. of Agricultural Sciences, Vindeln (Sweden). Dept. of Ecology and Environmental Research

    2005-06-01

    The aim was to assess long-term effects of wood-ash and lime application on the soil fauna diversity. The study was made at three sites, Oeringe and Torup in the county of Halland and Asa in the county of Smaaland, 20, 14 and 10 years after treatment, respectively. The soil fauna groups reported here are Enchytraeidae, Tardigrada and Oribatida. Different kinds of wood ash results in very different effects on soil pH despite similar dose. Non-hardened fresh ash increased pH as indicated by the liming potential (ca. 2 tonnes of CaCO{sub 3} correspond to 2,4 tonnes of loose ash). Hardened wood ash (at Asa) had a smaller effect on pH than corresponding amount of lime, and ca. 6 tonnes of ash/ha were needed to obtain the same effects as 3 tonnes of lime. Granulated wood ash (at Torup) had an even smaller effect on pH than the hardened ash at Asa. A preliminary estimate is that 6 tonnes/ha granulated ash correspond to 3 tonnes/ha of hardened ash, 1.5 tonnes/ha of non-hardened loose ash and 1 tonne/ha of CaCO{sub 3}. The results with regard to soil fauna show that individual numbers, species numbers and single species of Enchytraeidae and Oribatid mites are strongly dependent on the ash/lime effect on pH in the topsoil layer. Lime and ash appear to have similar effect on these animal groups provided that the pH effect is similar. Therefore, it is possible to extrapolate conclusions from liming trials to ash trials, provided that the pH effect is known. The Tardigrades did not seem to react on the treatments. We conclude that the effect of wood ash on the diversity of soil fauna investigated depends on the solubility of the wood ash and its effect on soil pH. Depending on the effect on pH, ash application results in (a) decreasing densities but increasing species numbers of enchytraeids, (b) decreasing densities but no change in species numbers of oribatid mites and (c) a strong change in the community structure of both enchytraeids and oribatid mites.

  10. Vacuum-soaking of wood chip shiitake (Lentinula edodes) logs to reduce soak time and log weight variability and to stimulate mushroom yield.

    Science.gov (United States)

    Royse, D J; Rhodes, T W; Sanchez, J E

    2002-01-01

    Synthetic logs were vacuum-soaked or regular-soaked to determine the effects of soaking on yield and mushroom size, log weight variability and water distribution within the log. Yields (g/log) from substrates vacuum-soaked were higher by 26.7%, 18.6% and 35.8% (mean = 27.2%) for crops I, II and III, respectively, when compared with regular-soaked. However, mushroom size averaged only 11.2 g for vacuum-soaked logs vs 17 g for regular-soaked logs (51.8% larger for regular-soaked). The time required for vacuum-soaking logs was generally less than 3 min, compared with regular-soaking times ranging over 3-15 h. Water tended to accumulate more in the outside zone in the vacuum-soaked logs, compared with regular-soaked logs. Mean moisture contents for crops I and II for outside, middle and interior zones of vacuum-soaked logs were 66%, 47.5% and 42.2%, respectively, while regular-soaked logs for the same zones were 62.4%, 52.1% and 50.9%, respectively. Vacuum-soaked log weights had lower standard deviations than weights for regular-soaked logs in four out of six soaks, indicating a more uniform soaking process.

  11. 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.

  12. 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....

  13. Effect of Instructions on Selected Jump Squat Variables.

    Science.gov (United States)

    Talpey, Scott W; Young, Warren B; Beseler, Bradley

    2016-09-01

    Talpey, SW, Young, WB, and Beseler, B. Effect of instructions on selected jump squat variables. J Strength Cond Res 30(9): 2508-2513, 2016-The purpose of this study was to compare 2 instructions on the performance of selected variables in a jump squat (JS) exercise. The second purpose was to determine the relationships between JS variables and sprint performance. Eighteen male subjects with resistance training experience performed 2 sets of 4 JS with no extra load with the instructions to concentrate on (a) jumping for maximum height and (b) extending the legs as fast as possible to maximize explosive force. Sprint performance was assessed at 0- to 10-m and 10- to 20-m distances. From the JS jump height, peak power, relative peak power, peak force, peak velocity, and countermovement distance were measured from a force platform and position transducer system. The JS variables under the 2 instructions were compared with paired t-tests, and the relationships between these variables and sprint performance were determined with Pearson's correlations. The jump height instruction produced greater mean jump height and peak velocity (p 0.05). Jump height was the variable that correlated most strongly with 10-m time and 10- to 20-m time under both instructions. The height instruction produced a stronger correlation with 10-m time (r = -0.455), but the fast leg extension JS produced a greater correlation with 10-20 time (r = -0.545). The results indicate that instructions have a meaningful influence on JS variables and therefore need to be taken into consideration when assessing or training athletes.

  14. 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.

  15. The effects of criterion variability on relative operating characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Brown, W.S. [Brookhaven Natl. Lab., Bldg. 130, Upton, NY 11973-5000 (United States); Emmerich, D.S. [State Univ. of New York at Stony Brook, Stony Brook, NY 11974 (United States)

    1995-05-01

    The form of the relative operating characteristic (ROC) describing auditory detection typically differs from that expected based on the assumption that the observer`s responses reflect underlying distributions that are normal and of equal variance [e.g., Green and Swets, {ital Signal} {ital Detection} {ital Theory} {ital and} {ital Psychophysics}]. Specifically, it is found that binormal ROCs often have slopes less than one, and are not strictly linear [Watson {ital et} {ital al}., 283--288 (1964)]. It has been suggested that nonlinear binormal ROCs may be the result of extreme criteria being more variable than those more centrally positioned [Emmerich and Binder, J. Acoust. Soc. Am. Suppl. 1 {bold 65}, S59 (1979)]. The forms of rating ROCs obtained in an experiment designed to reveal the effects of such variability were consistent with the proposition that criteria associated with ``no`` responses are more variable than those associated with ``yes`` responses. Criterion operating characteristics [Wickelgren, J. Math. Psychol. {bold 5}, 102--122], which reflect the relative locations and variances of the boundaries of confidence categories, favored the same interpretation. It is concluded that the variability of criteria defining categories of rated confidence is sizable and not necessarily constant across criteria, and that such variability significantly influences the forms of empirical ROCs determined using confidence ratings in auditory signal detection.

  16. Recognition and rating of effecting indexes on consumption of different sites poplar wood production in Iran for paper making industries

    Directory of Open Access Journals (Sweden)

    ebrahim lashkarbolouki

    2016-12-01

    Full Text Available Considering the growth in population, the need for wood consumption also increases. The rapid progress of science and technology doubles the wood consumption. Supplying this need at a glance was focused on the forests. Forests for many reasons have faced decrease in production and this extreme need for wood, by planting fast growing trees (poplar, eucalypt, Paulownia … makes it possible. One of industries plenty of the wood is paper industry that needs to huge primary wood material. This industry can continue their production activities by using the wood of poplar. This research was found out with the aim of assessing the practical characteristics of poplar wood by nondestructive test method in paper production industry. Poplar sites were selected in areas of country that poplar trees were planted widely. For locating the production of different site in paper industry found out Analytic Hierarchy Process (AHP in Expert choice 11 software. For field studies of this research, the questionnaires were prepared and sent for expert and university professors with special expertise in this industry. The results showed that: Production of Pulp and paper industry: in this industry among of five main indexes influencing in pulp and paper production, fiber morphology trait recognized as first priority with weighting value (0.435. Production allocations with their weighting value are determined: Sari (0.240, Fouman (0.236, Lashtnasha (0.182, Abhar (0.174 and Zanjan (0.168, respectively.

  17. Effect of compression combined with steam treatment on the porosity, chemical compositon and cellulose crystalline structure of wood cell walls.

    Science.gov (United States)

    Yin, Jiangping; Yuan, Tongqi; Lu, Yun; Song, Kunlin; Li, Hanyin; Zhao, Guangjie; Yin, Yafang

    2017-01-02

    The changes of porosity, chemical composition and cellulose crystalline structure of Spruce (Picea abies Karst.) wood cell walls due to compression combined with steam treatment (CS-treatment) were investigated by nitrogen adsorption, confocal Raman microscopy (CRM) and X-ray diffraction (XRD), respectively. A number of slit-shaped mesopores with a diameter of 3.7nm was formed for the CS-treated wood, and more mesopores were found in the steam-treated wood. CRM results revealed cellulose structure was affected by treatment and β-aryl-ether links associated to guaiacyl units of lignin was depolymerized followed by re-condensation reactions. The crystallinity index (CrI) and crystallite thickness (D200) of cellulose for CS-treated wood were largely increased due to crystallization in the semicrystalline region. Higher degree of increase in both CrI and D200 was observed in both the earlywood and latewood of steam-treated wood, ascribing to the greater amount of mesopores in steam-treated wood than CS-treated wood. Copyright © 2016. Published by Elsevier Ltd.

  18. 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

  19. 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 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.

  20. 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.

  1. 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.

  2. 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

    Energy Technology Data Exchange (ETDEWEB)

    Graham, R.L.; Liu, W.; Downing, M. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Noon, C.E.; Daly, M. [Tennessee Univ., Knoxville, TN (United States). Management Science Program; Moore, A. [Energy Technology Support Unit, Harwell (United Kingdom)

    1997-12-31

    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 farm-gate prices and supplies of wood 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 2,700 000 dry Mg/y (3 000 000 dry t/y) 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 18-29% of the delivered cost and ranged between $8 and 18/dry Mg ($7 and 16/dry t). 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. (author)

  3. The Effect of Age on Technique Variability and Outcome Variability during a Leg Press.

    Directory of Open Access Journals (Sweden)

    Cassie Wilson

    Full Text Available The aim of this study was to determine the effect of aging on power generation and joint coordination during a leg press, in order to increase understanding of how functional movements are affected during the aging process. 44 older and 24 younger adults performed eight sub-maximal power repetitions on a seated leg press dynamometer. Peak power and velocity (at 40% maximum resistance were measured along with the coordination (coupling angle of the lower limb joints using the vector coding technique. The younger adults produced significantly greater peak power than the older adults (mean ± SD; 762 W ± 245 vs 361 W ± 162, p < 0.01 and at higher peak velocities (mean ± SD; 1.37 m/s ± 0.05 vs 1.00 m/s ± 0.06, p < 0.01. The older adults produced less consistent values of peak power than younger adults, evidenced by a higher coefficient of variation (mean ± SD; 7.6% ± 5.2 vs 5.0% ± 3.0, p < 0.01, however, there was significantly less variability in the coupling angles displayed by the older adults compared to the younger adults (mean ± SD; 2.0° ± 1.1 vs 3.5° ± 2.7, p < 0.01 (ankle-knee; 1.7° ± 0.6 vs 4.1° ± 3.0, p < 0.01 (knee-hip. The results of this study demonstrate that older adults display higher outcome variability but lower variability in technique (coordination. The more rigid movement strategies displayed by the older adults potentially reflects an increased risk of overuse injury due to repetitive demands on the same structures, or the reduced ability to respond to unexpected situations due to a lack of flexibility in joint control.

  4. 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.

  5. The effects of heat treatment on physical and technological properties and surface roughness of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood.

    Science.gov (United States)

    Gündüz, Gökhan; Korkut, Süleyman; Korkut, Derya Sevim

    2008-05-01

    Heat treatment is often used to improve the dimensional stability of wood. In this study, the effects of heat treatment on physical properties and surface roughness of Camiyani Black Pine (Pinus nigra Arn. subsp. pallasiana var. pallasiana) wood were examined. Samples obtained from Yenice-Zonguldak Forest Enterprises, Turkey, were subjected to heat treatment at varying temperatures and for varying durations. The physical properties of heat-treated and control samples were tested, and oven-dry density, air-dry density, and swelling properties were determined. The mechanical properties of heat-treated and control samples were tested, and compression strength, and Janka-hardness were determined. A stylus method was employed to evaluate the surface characteristics of the samples. Roughness measurements by the stylus method were made in the direction perpendicular to the fiber. Four main roughness parameters, mean arithmetic deviation of profile (Ra), mean peak-to-valley height (Rz), root mean square roughness (Rq), and maximum roughness (Ry) obtained from the surface of wood were used to evaluate the effect of heat treatment on the surface characteristics of the specimens. Significant difference was determined (p=0.05) between physical and technological properties, and surface roughness parameters (Ra, Rz, Ry, Rq) for three temperatures and three durations of heat treatment. Based on the findings in this study, the results showed that density, swelling, compression strength, Janka-hardness and surface roughness values decreased with increasing treatment temperature and treatment times. Increase in temperature and duration further diminished technological strength values of the wood specimens. Camiyani Black Pine wood could be utilized by using proper heat treatment techniques without any losses in strength values in areas where working, stability, and surface smoothness, such as in window frames, are important factors.

  6. Effect of composting on the Cd, Zn and Mn content and fractionation in feedstock mixtures with wood chips from a short-rotation coppice and bark.

    Science.gov (United States)

    Vandecasteele, B; Willekens, K; Zwertvaegher, A; Degrande, L; Tack, F M G; Du Laing, G

    2013-11-01

    Micronutrient content and availability in composts may be affected by the addition of wood chips or tree bark as a bulking agent in the compost feedstock. In the first part of this study, micronutrient levels were assessed in bark and wood of poplar and willow clones in a short-rotation coppice. Large differences between species were observed in bark concentrations for Cd, Zn and Mn. In the second part of the study, we aimed to determine the effect of feedstock composition and composting on Cd, Zn and Mn concentrations and availability. By means of three composting experiments we examined the effect of (a) bark of different tree species, (b) the amount of bark, and (c) the use of bark versus wood chips. In general, compost characteristics such as pH, organic matter and nutrient content varied due to differences in feedstock mixture and composting process. During the composting process, the availability of Cd, Zn and Mn decreased, although the use of willow and poplar bark or wood chips resulted in elevated total Cd, Zn or Mn concentrations in the compost. Cd concentrations in some composts even exceeded legal criteria. Cd and Zn were mainly bound in the reducible fraction extracted with 0.5M NH2OH⋅HCl. A higher acid-extractable fraction for Mn than for Cd and Zn was found. Higher Cd concentrations in the compost due to the use of bark or wood chips did not result in higher risk of Cd leaching. The results of the pH-stat experiment with gradual acidification of composts illustrated that only a strong pH decline in the compost results in higher availability of Cd, Zn and Mn. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2015-11-01

    This is the longest continuous experiment where ethylenediurea (EDU) was used to protect plants from ozone (O3). Effects of long-term ambient O3 exposure (23 ppm h AOT40) on biomass of an O3 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 O3 although the effect was significant only for stem and coarse roots. Ambient O3 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 O3 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Effect of size, seasoning and toasting in the volatile compounds in toasted oak wood and in a red wine treated with them.

    Science.gov (United States)

    Fernández de Simón, B; Cadahía, E; del Alamo, M; Nevares, I

    2010-02-15

    The increasing demand for wood for barrel-making in addition to the rapid extension of alternative aging system, have led to looking into the possibility of utilizing Spanish oak. Quercus pyrenaica is the species that predominates in Spain, and the chemical composition of its heartwood (ellagitannins, low molecular weight phenolic and volatile compounds) and its incidence in characteristics of wine are similar to that of other species that are of recognized oenological quality for barrel-making, showing only quantitative differences with respect to French (Quercus petraea) and American (Quercus alba) species. However, at present, the quantity of good quality wood that we can obtain from the Q. pyrenaica Spanish forest is limited. Hence, in the short term, and considering the high chemical oenological quality of Q. pyrenaica wood, we propose the utilizing of chips, segments, staves, and other oak alternatives for wine aging, which would be obtained from wooden remnants from barrel-making as well as from trees with small diameters or physical defects which would normally be inappropriate for cooperage. With regards to the latter idea, studies on special chip-making processes, and other oak wood pieces are being carried out, especially focused on reducing seasoning time, and to toasting optimization as a function of wood piece size, in addition to its behaviour when incorporated into the different alternative aging systems. We present in this study the effect of seasoning way (traditional or unconventional) on volatile composition of Q. pyrenaica chips and staves at three toasting levels (light, medium and heavy), and the evolution of the wood-released aromatic composition of a Spanish artificially aged wine, using these alternative products. The wines showed in general small differences in their oak-derived characteristics, which were more related to the wood piece size and the toasting intensity than to the seasoning way, and they could be linked with the

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

    Science.gov (United States)

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

    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°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.

  11. Tolerance to wood preservatives by copper-tolerant wood-rot fungi native to south-central Chile.

    Science.gov (United States)

    Guillén, Yudith; Navias, David; Machuca, Angela

    2009-02-01

    Understanding the effect of heavy metals and wood preservatives on the growth of wood-rot fungi native to a certain region may improve reliability in determining the effectiveness of antifungal products, particularly when dealing with new formulations. In this investigation, strains of copper-tolerant wood-rot fungi native to south-central Chile were evaluated against two preservatives: commercial chromated copper arsenate type C (CCA-C) and a new formulation with boron and silicon (BS). Thirteen native strains, mainly white-rot fungi, were selected for their high growth rates in solid medium containing 3 mM of copper. A short-term test was then carried out, consisting of adding cellulose disks impregnated with different concentrations of preservatives to solid culture media inoculated with selected copper tolerant strains. There was a great variability in interspecific and intraspecific responses to the presence of copper and preservatives in culture media. Among the native and commercial strains evaluated, the white-rot fungi Trametes versicolor 38 and mainly Ganoderma australe 100 were notable for their tolerance to all the CCA-C and BS concentrations. The brown-rot fungus Wolfiporia cocos, used as reference strain, showed a high tolerance to CCA-C, but not to BS preservative. T. versicolor 38 and G. australe 100 were selected for subsequent studies on preserved wood degradation.

  12. Soil food web structure after wood ash application

    DEFF Research Database (Denmark)

    Mortensen, Louise Hindborg; Qin, Jiayi; Cruz-Paredes, Carla

    to be slightly negatively affected, however the bacteria feeding nematodes a bit less so. The effects had not yet transferred to the lower soil layer (3-6 cm) at the site. Sampling in 2016 and 2017 will clarify the variability of both indirect effects of wood ash application to the terrestrial food web......In 2006, the European Council established a mandatory target of 20 % renewable energy of consumption by 2020. Part of the replacement is burning biomass for heating and electricity. ~ Whole tree biomass harvesting for biofuel combustion intensifies removal of nutrients from the by applying ash from...... the consequences of returning wood ash to biofuel producing coniferous forest. We that the change in pH and increased availability of nutrients after ash application to forest floor can facilitate an increase in the bacteria to fungi ratio with possible effects for the soil food by applying ash of different...

  13. Intraspecific competition in the speckled wood butterfly Pararge aegeria: Effect of rearing density and gender on larval life history

    Directory of Open Access Journals (Sweden)

    Melanie Gibbs

    2004-05-01

    Full Text Available In insects, the outcome of intraspecific competition for food during development depends primarily upon larval density and larval sex, but effects will also depend on the particular trait under consideration and the species under study. Experimental manipulations of larval densities of a Madeiran population of the speckled wood butterfly Pararge aegeria confirmed that intraspecific competition affected growth. As densities increased P. aegeria adults were smaller and larval development periods were longer. Sexes responded differently to rearing density. Females were more adversely affected by high density than males, resulting in females having smaller masses at pupation. Survivorship was significantly higher for larvae reared at low densities. No density effect on adult sex ratios was observed. Intraspecific competition during the larval stage would appear to carry a higher cost for females than males. This may confer double disadvantage since females are dependent on their larval derived resources for reproduction as they have little opportunity to accumulate additional resources as adults. This suggests that shortages of larval food could affect fecundity directly. Males, however, may be able to compensate for a small size by feeding as adults and/or by altering their mate location tactics.

  14. Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature.

    Science.gov (United States)

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2008-03-01

    It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy. (c) 2008 Wiley-Liss, Inc.

  15. Maternal effects, flight versus fecundity trade-offs, and offspring immune defence in the Speckled Wood butterfly, Pararge aegeria

    Directory of Open Access Journals (Sweden)

    Hails Rosemary S

    2010-11-01

    Full Text Available Abstract Background Maternal condition can generate resource-related maternal effects through differential egg provisioning, and can greatly affect offspring performance. In the present study, the speckled wood butterfly Pararge aegeria (L. was used to investigate whether (after controlling for egg size maternal age, and increased flight during the oviposition period, resulted in changes in egg provisioning and whether this contributed to variation in offspring performance, i early in development (egg stage and early post-hatching development, and ii later in larval development after being exposed to the model viral pathogen system; the baculovirus Autographa californica multinucleocapsid nucleopolyhedrovirus (AcMNPV. Results Age-related changes in maternal egg provisioning were observed to influence egg stage development only. Flight-induced changes in maternal egg provisioning had direct consequences for offspring growth and survival across each life stage from egg to adulthood; offspring from forced flight mothers had lower larval masses and longer development times. Offspring with lower larval masses also had reduced survival after exposure to the viral pathogen. Conclusion The present study demonstrates that a change in maternal provisioning as a result of increased flight during the oviposition period has the potential to exert non-genetic cross-generational fitness effects in P. aegeria. This could have important consequences for population dynamics, particularly in fragmented anthropogenic landscapes.

  16. Effects of a natural extract of chestnut wood on digestibility, performance traits, and nitrogen balance of broiler chicks.

    Science.gov (United States)

    Schiavone, A; Guo, K; Tassone, S; Gasco, L; Hernandez, E; Denti, R; Zoccarato, I

    2008-03-01

    Currently, feed ingredients containing tannin are attracting more interest as substitutes for antibiotic growth promoters in animal and poultry feeding. This study investigated the influence of a natural extract of chestnut wood (Silvafeed ENC) on broiler digestibility (experiment 1) and on the growth performance, carcass quality, and nitrogen balance of broilers (experiment 2). Results showed that the inclusion of ENC did not influence the apparent digestibility of organic matter, CP, and ether extract. Chick growth performance showed a quadratic or cubic response with increasing levels of ENC. When chicks were fed ENC from 14 to 56 d of age, the ENC had a positive effect on average daily gain in the first 2 wk of addition, whereas this effect was not evident in the last 2 wk compared with the control group. Similar trends were also shown for daily feed intake. Overall, the chicks fed 0.20% ENC had significantly better growth performance than the control group. Carcass analysis showed no gross lesions in organs and no significant differences in thigh and breast composition among groups. Noteworthy is the fact that the ENC-treated groups had less total litter nitrogen; in particular, chicks fed 0.15 and 0.20% ENC showed a significant difference in total litter nitrogen compared with the control group. No significant difference in nitrogen balance was observed. Addition of 0.20% ENC seemed to have a positive influence on chick feeding.

  17. 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.

  18. 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 ...

  19. The effects of seasonally variable dragonfly predation on butterfly assemblages.

    Science.gov (United States)

    Tiitsaar, Anu; Kaasik, Ants; Teder, Tiit

    2013-01-01

    Where predation is seasonally variable, the potential impact of a predator on individual prey species will critically depend on phenological synchrony of the predator with the prey. Here we explored the effects of seasonally variable predation in multispecies assemblages of short-lived prey. The study was conducted in a landscape in which we had previously demonstrated generally high, but spatially and seasonally variable dragonfly-induced mortality in adult butterflies. In this system, we show that patterns of patch occupancy in butterfly species flying during periods of peak dragonfly abundance are more strongly associated with spatial variation in dragonfly abundance than patch occupancy of species flying when dragonfly density was low. We provide evidence indicating that this differential sensitivity of different butterfly species to between-habitat differences in dragonfly abundance is causally tied to seasonal variation in the intensity of dragonfly predation. The effect of dragonfly predation could also be measured at the level of whole local butterfly assemblages. With dragonfly density increasing, butterfly species richness decreased, and butterfly species composition tended to show a shift toward a greater proportion of species flying during periods of off-peak dragonfly abundance.

  20. Estimating peer effects in longitudinal dyadic data using instrumental variables.

    Science.gov (United States)

    O'Malley, A James; Elwert, Felix; Rosenquist, J Niels; Zaslavsky, Alan M; Christakis, Nicholas A

    2014-09-01

    The identification of causal peer effects (also known as social contagion or induction) from observational data in social networks is challenged by two distinct sources of bias: latent homophily and unobserved confounding. In this paper, we investigate how causal peer effects of traits and behaviors can be identified using genes (or other structurally isomorphic variables) as instrumental variables (IV) in a large set of data generating models with homophily and confounding. We use directed acyclic graphs to represent these models and employ multiple IV strategies and report three main identification results. First, using a single fixed gene (or allele) as an IV will generally fail to identify peer effects if the gene affects past values of the treatment. Second, multiple fixed genes/alleles, or, more promisingly, time-varying gene expression, can identify peer effects if we instrument exclusion violations as well as the focal treatment. Third, we show that IV identification of peer effects remains possible even under multiple complications often regarded as lethal for IV identification of intra-individual effects, such as pleiotropy on observables and unobservables, homophily on past phenotype, past and ongoing homophily on genotype, inter-phenotype peer effects, population stratification, gene expression that is endogenous to past phenotype and past gene expression, and others. We apply our identification results to estimating peer effects of body mass index (BMI) among friends and spouses in the Framingham Heart Study. Results suggest a positive causal peer effect of BMI between friends. © 2014 The Authors. Biometrics published by Wiley Periodicals, Inc. on behalf of International Biometric Society.

  1. 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

  2. Effects of biochar and wood pellets amendments added to landfill cover soil on microbial methane oxidation: A laboratory column study.

    Science.gov (United States)

    Yargicoglu, Erin N; Reddy, Krishna R

    2017-05-15

    Alternate landfill covers designed to enhance microbial methane (CH 4 ) oxidation and reduce the negative impacts of landfill gas emissions on global climate have recently been proposed and investigated. In this study, the use of biochar as a soil amendment is examined in order to assess the feasibility and effectiveness for enhanced CH 4 removal in landfill covers when incorporated under high compaction conditions and relatively low soil moisture. Four different cover configurations were tested in large soil columns for ∼510 days and potential CH 4 oxidation rates were determined following long-term incubation in small batch assays. Cover designs tested include: a thin biochar layer at 15-18 cm; 2% mixed soil-biochar layer at 20-40 cm; 2% mixed soil-uncharred wood pellets at 20-40 cm; and soil obtained from intermediate cover at an active landfill site. The placement of a thin biochar layer in the cover significantly impacted moisture distribution and infiltration, which in turn affected CH 4 oxidation potential with depth. An increase in CH 4 removal rates was observed among all columns over the 500 day incubation period, with steady-state CH 4 removal efficiencies ranging from ∼60 to 90% in the final stages of incubation (inlet load ∼80 g CH 4  m -2  d -1 ). The thin biochar layer had the lowest average removal efficiency as a result of reduced moisture availability below the biochar layer. The addition of 2% biochar to soil yielded similar CH 4 oxidation rates in terminal assays as the 2% uncharred wood pellet amendment. CH 4 oxidation rates in terminal assays were positively correlated with soil moisture, which was affected by the materials' water holding capacity. The high water holding capacity of biochar led to higher oxidation rates within the thin biochar layer, supporting the initial hypothesis that biochar may confer more favorable physical conditions for methanotrophy. Ultimate performance was apparently affected by soil type and CH 4

  3. 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.

  4. 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

  5. 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...

  6. Energy from wood

    Science.gov (United States)

    J.I. Zerbe

    2004-01-01

    In most developing countries wood and charcoal are the predominant fuels for preparation of food to maintain the quality of life that encompasses the majority of citizens. In many developing countries wood fuels are also important for small and medium size industries. Moreover, energy from wood continues to be important in industrial countries. In the USA biomass...

  7. Wood Formation in Trees

    Science.gov (United States)

    Melanie Mauriat; Gregoire Le Provost; Phillippe Rozenberg; Sylvain Delzon; Nathalie Breda; Bruno Clair; Catherine Coutand; Jean-Christoph Domec; Thierry Fourcaud; Jacqueline Grima-Pettenati; Raul Herrera; Jean-Charles Leple; Nicolas Richet; Jean-Francois Trontin; Christophe Plomion

    2014-01-01

    Among the ecosystem services provided by forests, wood provisioning takes a central position. Wood and derived products have played a critical role in the evolution of human kind and demand for raw material is increasing in a foreseeable future. Wood is used for energy production, construction and a wide variety of products for which different properties are required....

  8. 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

  9. 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.

  10. The Effect of Clear Paints, Nanozycofil and Nanozycosil on Water Absorption and Contact Angle of Poplar Wood

    Directory of Open Access Journals (Sweden)

    Hadi Gholamian

    2012-01-01

    Full Text Available In this research, the effect of nano-zycosil, nano-zycofil, acid catalyzed lacquer and nitrocellulose lacquer and polyester on improving the water absorption and contact angle of wood was investigated. Some boards were prepared from the sapwood of poplar (P.nigra. They were dried based  on T6E3 schedule and some specimens were cut according to EN 927-5 standard (20 × 70 × 150 mm.  They were coated and immersed with the nano particles and clear paints.  The clear paint- and nanoparticles-coated samples were dried in laboratory environment and in an oven at the temperatures of 1032°c, respectively. After drying process, the water absorption of the samples was measured after 2, 24, 72, 168 h immersion. The contact angle of samples was measured after 1 and 10 seconds. The results revealed that the pattern of water absorption for the paints and nanoparticles is different. The samples coated with combined acid catalyzed lacquers and nitrocellulose lacquers and those coated with nanozycosil had the highest resistance to water absorption. The greatest contact angle was observed for the samples coated by nanozycosil.

  11. Effect of Ammonium Polyphosphate to Aluminum Hydroxide Mass Ratio on the Properties of Wood-Flour/Polypropylene Composites

    Directory of Open Access Journals (Sweden)

    Wen Wang

    2017-11-01

    Full Text Available Two halogen-free inorganic flame retardants, ammonium polyphosphate (APP and aluminum hydroxide (ATH were added to wood-flour/polypropylene composites (WPCs at different APP to ATH mass ratios (APP/ATH ratios, with a constant total loading of 30 wt % (30% by mass. Water soaking tests indicated a low hygroscopicity and/or solubility of ATH as compared to APP. Mechanical property tests showed that the flexural properties were not significantly affected by the APP/ATH ratio, while the impact strength appeared to increase with the increasing ATH/APP ratio. Cone calorimetry indicated that APP appeared to be more effective than ATH in reducing the peak of heat release rate (PHRR. However, when compared to the neat WPCs, total smoke release decreased with the addition of ATH but increased with the addition of APP. Noticeably, WPCs containing the combination of 20 wt % APP and 10 wt % ATH (WPC/APP-20/ATH-10 showed the lowest PHRR and total heat release in all of the formulations. WPCs combustion residues were analyzed by scanning electron microscopy, laser Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR. Thermogravimetric analysis coupled with FTIR spectroscopy was used to identify the organic volatiles that were produced during the thermal decomposition of WPCs. WPC/APP-20/ATH-10 showed the most compact carbonaceous residue with the highest degree of graphitization.

  12. 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.

  13. Effects of heat pretreatment of starch on graft copolymerization reaction and performance of resulting starch-based wood adhesive.

    Science.gov (United States)

    Zheng, Xianyu; Cheng, Li; Gu, Zhengbiao; Hong, Yan; Li, Zhaofeng; Li, Caiming

    2017-03-01

    In this study, effects of starch heat pretreatment at 70, 80 and 90°C on graft copolymerization reaction with vinyl acetate (VAc) and the performance of the resulting starch-based wood adhesive (SWA) were investigated. It was shown that SWA pretreated at 90°C achieved the best performance. At this temperature, the bonding capacity improved by 17.84% compared to the adhesive synthesized without heat pretreatment and the viscosity increased by 18.16% after 7 free-thaw cycles, much better than other samples. Scanning electron microscopy (SEM) and polarizing microscopy demonstrated that structures of starch granules were fully damaged after heat pretreatment at 90°C. The reaction took place not only on the surface of starch granules, but also internally, leading to improvement in the grafting amounts and grafting efficiency by 42.86% and 39.03%, respectively. This was further confirmed by Fourier transform infrared spectroscopy (FT-IR), Confocal Raman microscopy (CRM) and X-ray photoelectron spectroscopy (XPS), which also showed better reaction homogeneity both between different starch granules and from granule surface to its internal structure. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The effect of combined colloidal nano silver-hydrothermal treatment on weight changes and chemical structure of beech wood (Fagus orientalis)

    OpenAIRE

    مریم قربانی; rahim aghayi; poriya biparva

    2015-01-01

    Synthesis of colloidal silver nano-particles, as well as the effect of combined colloidal nano-silver and hydrothermal modification, on weight and chemical changes of wood particles through spectroscopic FTIR were investigated. Treatment levels were divided in 4 groups namely, control, nano- impregnated, hydrothermal and nano-hydrothermal. Hydrothermal and nano-hydrothermal treatments were separated in two temperatures (150 and 170 °C) and two times (30 and 45 min) with total of 10 treatment ...

  15. 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....

  16. Bench-scale gasification of cedar wood--part II: effect of operational conditions on contaminant release.

    Science.gov (United States)

    Aljbour, Salah H; Kawamoto, Katsuya

    2013-01-01

    Here, we present the evolution profile of tar in the product gas during cedar biomass gasification. We also discuss the evolution of other contaminants (H(2)S, COS, NH(3), HCN, and HCl). The cedar wood was gasified under various operating conditions in a bench-scale externally heated updraft gasifier; this was followed by thermal reforming. Tar levels in the product gas were significantly affected by the operating conditions used. At a gasification temperature of 923 K, there was no clear relation between the evolution of phenolic tar in the product gas as a function of residence time. The evolution of PAH tar at a low gasification temperature was lower than the evolution of phenolic tar. With increasing temperature, the proportion of PAH tar content became significant. At a gasification temperature of 1223 K, increasing the residence time reduced the content of PAH tar owing to a catalytic effect associated with ash generation at high temperatures. Increasing the steam-to-carbon (S/C) ratio under thermal conditions had a slight effect on PAH conversion. However, increasing the equivalence ratio (ER) effectively reduced the tar levels. The conversion of fuel-sulfur and fuel-nitrogen to volatile-sulfur and volatile-nitrogen, respectively, increased with increasing S/C ratio and ER. The evolutions of COS and HCN gases were much smaller than the evolution of H(2)S and NH(3). The evolution of HCl in the product gas decreased slightly with increasing ER. Increasing the S/C ratio decreased the HCl levels in the product gas. The effect of temperature on contaminant levels could not be fully understood due to limited availability of experimental data at various temperatures. We also compare our findings with data in the literature. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. 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 ...

  18. Effects of UV-accelerated weathering and natural weathering conditions on anti-fungal efficacy of wood/PVC composites doped with propylene glycol-based HPQM

    Directory of Open Access Journals (Sweden)

    P. Srimalanon

    2016-04-01

    Full Text Available This work studied the mechanical, physical and weathering properties and anti-fungal efficacy of polyvinyl chloride(PVC and wood flour/polyvinyl chloride composites(WPVC. 2-hydroxypropyl-3-piperazinyl-quinoline carboxylic acid methacrylate (HPQM in propylene glycol was used as an anti-fungal agent. Propylene glycol-based HPQM was doped in neat PVC and in WPVC containing 50 and 100 pph wood (WPVC-50 and WPVC-100. The flexural properties of PVC decreased when propylene glycol-based HPQM was added. However, adding this component did not affect the flexural properties of WPVC. Fungal growth inhibition test and dry weight technique were used for evaluation of anti-fungal effectiveness. Aspergillus niger was used as a testing fungus. Adding propylene glycol-based HPQM to WPVC-100 led to the most effective anti-fungal performance. Wood flour acted as an anti-fungal promoter for the WPVC composites. The optimal dosages of propylene glycol-based HPQM in PVC, WPVC-50, and WPVC-100 were 50000, 15000, and 10000 ppm, respectively. UV-accelerated weathering aging and natural weathering conditions were found to affect the flexural properties of PVC and WPVC. The change in the anti-microbial performance of WPVC under natural weathering were slower than those under UV-accelerated weathering aging. The anti-microbial evaluation indicated that the samples doped with less than 20000 ppm propylene glycol-based HPQM had a more pronounced effect than the ones doped with higher dosages.

  19. 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.

  20. Wood Anatomical Structure Of The Clones Of Eucalyptus Tereticornis Sm. Mysore Gum

    OpenAIRE

    P. Sreevani; R. V. Rao

    2015-01-01

    Abstract Wood being a natural material is very variable. This variability is attributed mostly to variations in the anatomical structure of the wood. The wood structure of five clones at macroscopic level and microscopic level is provided for the first time. In addition study on the general features of all the clones are also described. Thus the information provided is a starting point to understand the wood structure of the clonal material as well as identification of some of the clones on t...

  1. Discrimination constrained and justified : Variable effects of group variability and in-group identification

    NARCIS (Netherlands)

    Jetten, J; Spears, R; Hogg, MA; Manstead, ASR

    In two studies we investigated how group variability influences the degree to which in-group bias is expressed by high and low group identifiers. Group members were provided with group variability and group status feedback in a minimal (Study 1) and in a natural group setting (Study 2). Results show

  2. Short-term effects of human urine fertiliser and wood ash on soil pH and electrical conductivity

    Directory of Open Access Journals (Sweden)

    Dora Neina

    2014-03-01

    Full Text Available The fertiliser value of human urine has been examined on several crops, yet little is known about its effects on key soil properties of agronomic significance. This study investigated temporal soil salinization potential of human urine fertiliser (HUF. It further looked at combined effects of human urine and wood ash (WA on soil pH, urine-NH_3 volatilisation, soil electrical conductivity (EC, and basic cation contents of two Acrisols (Adenta and Toje series from the coastal savannah zone of Ghana. The experiment was a factorial design conducted in the laboratory for 12 weeks. The results indicated an increase in soil pH by 1.2 units for Adenta series and 1 unit for Toje series after one week of HUF application followed by a decline by about 2 pH units for both soil types after twelve weeks. This was attributed to nitrification of ammonium to nitrate leading to acidification. The EC otherwise increased with HUF application creating slightly saline conditions in Toje series and non-saline conditions in Adenta series. When WA was applied with HUF, both soil pH and EC increased. In contrast, the HUF alone slightly salinized Toje series, but both soils remained non-saline whenWA and HUF were applied together. The application ofWA resulted in two-fold increase in Ca, Mg, K, and Na content compared to HUF alone. Hence, WA is a promising amendment of acid soils and could reduce the effect of soluble salts in human urine fertilizer, which is likely to cause soil salinity.

  3. Bench-scale gasification of cedar wood--part I: effect of operational conditions on product gas characteristics.

    Science.gov (United States)

    Aljbour, Salah H; Kawamoto, Katsuya

    2013-01-01

    The present study was conducted within the framework of R&D activities on the development of gasification and reforming technologies for energy and chemical recovery from biomass resources. Gasification of the Japanese cedar wood has been investigated under various operating conditions in a bench-scale externally heated updraft gasifier; this was followed by thermal reforming. Parametric tests by varying the residence times, gasification temperatures, equivalence ratios (ERs) and steam-to-carbon (S/C) ratios were performed to determine their effects on the product gas characteristics. Thermodynamic equilibrium calculations were preformed to predict the equilibrium gas composition and compared with the experimental value. We found that the product gas characteristics in terms of the H(2)/CO ratio, CO(2)/CO ratio, and CH(4) and lighter hydrocarbons concentrations are significantly affected by the operating conditions used. Increasing the residence time decreased the CO(2)/CO ratio; however, a nominal effect was noticed on H(2) concentration as a function of the residence time. At sufficient residence time, increasing the temperature led to higher H(2) yields, CO efficiency and higher heating value (HHV) of the product gas. The presence of steam during gasification effectively enhanced the proportion of H(2) in the product gas. However, higher S/C ratio reduced the HHV of the product gas. Increasing the ER from 0 to 0.3 increased the H(2) yields and CO efficiency and decreased the HHV of the product gas. The evolution of CH(4) and lighter hydrocarbons at low gasification temperatures was relatively higher than that at high temperature gasification. The evolution of CH(4) and lighter hydrocarbons at high gasification temperatures hardly varied over the investigated operating conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. 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.

  5. INFLUENCE OF CLONE HARVESTING AGE OF Eucalyptus grandis AND HYBRIDS OF Eucalyptus grandis x Eucalyptus urophylla IN THE WOOD CHEMICAL COMPOSITION AND IN KRAFT PULPABILITY

    OpenAIRE

    Paulo Henrique Damasceno de Morais; Dalton Longue Júnior; Jorge Luiz Colodette; Elisa Helena da Costa Morais; Carolina Marangon Jardim

    2017-01-01

    ABSTRACT The recent efforts on the quality of the wood used in pulp and paper mills has focused in many points, among them the influence of the raw material chemical characteristics in the production process and final product quality. Considering the current demand for younger trees, the effect of the wood harvesting age in the chemical composition and in the process variables becomes a very important fact for the industries of this sector. So, the objective of this study was to characterize ...

  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...... of deformation and strength of wood are divided into three groups: cellular models (applied most often to the mesoscale or cell scale analysis of the wood deformation), continuum micromechanics and homogenization based methods, models which consider wood as a composite and are applied mainly to the analysis...... of wood at the microscale (cell wall scale) level and multiscale models. Lattice and composite models, which are used to analyze the damage and fracture of wood, are considered in a separate section. The areas of applicability and strong sides of each approach are discussed. (C) 2008 Elsevier B.V. All...

  7. The Effects of Land Configuration and Wood-Shavings Mulch on the Properties of a Sandy Loam Soil in Northeast Nigeria. 1. Changes in Chemical Properties

    Directory of Open Access Journals (Sweden)

    Chiroma, AM.

    2006-01-01

    Full Text Available In the savanna region of Nigeria, the search continues for practices that will improve the productivity of the fragile soils characterized by low organic matter and plant nutrients, poor structure and very high permeability. A 4-year (1999-2002 field experiment was conducted to determine the effects of land configuration and wood-shavings mulch on soil chemical properties under rainfed sorghum. The treatments were Flat Bed (FB as control, Open-ridge (OR, Tied-ridge (TR, Flat bed with wood-shavings mulch (FBM, Open-ridge with wood-shaving mulch (ORM and Tied-ridge with wood-shavings mulch (TRM. Wood-shavings at the rate of 5 t/ha were used in 1999 but the rate was increased to 10 t/ha during subsequent years to ensure adequate soil coverage. Soil samples from 0.075 m depth were obtained at the end of the third (2001 and fourth (2002 cropping seasons and analysed for pH, organic carbon (OC, total nitrogen (TN, available P (AP, exchangeable acidity, exchangeable K+, Ca++ Mg++ and Na+. The results indicate that over the 4-year study period, the topsoil in all the treatments acidified but the rate of acidification was much faster in bare treatments (FB, OR and TR than in the mulched treatments (FBM, ORM and TRM, irrespective of tillage methods. In 2002; OC, TN and AP in the top 0-0.075 m layer of the wood-shavings amended soil were 24-29, 15-23 and 92-112% higher, respectively, than in the unamended control. OC in this soil layer correlated with TN (r= 0.98** and AP (r= 0.97**. Similarly, the three bare treatments experienced a rapid loss in exchangeable K+, Ca++ Mg++ and Na+ between 1999 and 2002 but the reduction was much greater in OR and TR treatments compared to the FB treatment. FBM, ORM and TRM treatments significantly improved the topsoil fertility with respect to exchangeable K+, Ca++ and Mg++ content. This was attributed to the release of these exchangeable cations from the decomposing organic mulch. These results demonstrate the potential

  8. East Urals Radioactive Trace: Dose-dependent functional-metabolic effects in the myocardium of the pygmy wood mouse (Apodemus uralensis) taking into account population size.

    Science.gov (United States)

    Orekhova, Nataĺya A; Modorov, Makar V

    2017-09-01

    The population dynamics, radiometric data and biochemical parameters (concentrations of total lipids, proteins, DNA and RNA, activity of succinate dehydrogenase, glucose phosphate isomerase and catalase, as well as lipid peroxidation level) in the myocardium of the pygmy wood mouse (Apodemus uralensis Pall., 1811) inhabiting the area of the East Urals Radioactive Trace (EURT) were analyzed. The functional-metabolic radiation effects as a result external and internal exposure to (137)Cs and (90)Sr (unweighted total dose rate 0.04-0.5 mGy/day) are characterized by a reduction in lipid catabolism, mitochondrial oxidation and antioxidant defense, as well as the activation of anaerobic glycolysis as well as the protein-synthesizing and genetic apparatus. The data indicate the low efficiency of cell energy production and allow us to state that compensatory myocardial hypertrophy can improve myocardial contractile function. The level of the functional-metabolic response in pygmy wood mice in the EURT area increased with increasing whole-body radiation dose rate and was more pronounced with a large pygmy wood mouse population size. The harmful effects (cardiac decompensation stage) of synergies resulting from non-radiation and radiation factors manifest after population abundance above 30 ind./100 trap-day and a radiation burden above 0.1 mGy/day. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. 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.)

  10. 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.

  11. Variability of adjacency effects in sky reflectance measurements.

    Science.gov (United States)

    Groetsch, Philipp M M; Gege, Peter; Simis, Stefan G H; Eleveld, Marieke A; Peters, Steef W M

    2017-09-01

    Sky reflectance Rsky(λ) is used to correct in situ reflectance measurements in the remote detection of water color. We analyzed the directional and spectral variability in Rsky(λ) due to adjacency effects against an atmospheric radiance model. The analysis is based on one year of semi-continuous Rsky(λ) observations that were recorded in two azimuth directions. Adjacency effects contributed to Rsky(λ) dependence on season and viewing angle and predominantly in the near-infrared (NIR). For our test area, adjacency effects spectrally resembled a generic vegetation spectrum. The adjacency effect was weakly dependent on the magnitude of Rayleigh- and aerosol-scattered radiance. The reflectance differed between viewing directions 5.4±6.3% for adjacency effects and 21.0±19.8% for Rayleigh- and aerosol-scattered Rsky(λ) in the NIR. Under which conditions in situ water reflectance observations require dedicated correction for adjacency effects is discussed. We provide an open source implementation of our method to aid identification of such conditions.

  12. 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.

  13. Wood production, wood technology, and biotechnological impacts.

    OpenAIRE

    2007-01-01

    In the year 2001, Prof. Dr. Ursula Kües was appointed at the Faculty of Forest Sciences and Forest Ecology of the Georg-August-University Göttingen to the chair Molecular Wood Biotechnology endowed by the Deutsche Bundesstiftung Umwelt (DBU). Her group studies higher fungi in basic and applied research. Research foci are on mushroom development and on fungal enzymes degrading wood and their applications in wood biotechnology. This book has been edited to thank the DBU for all support given to...

  14. Air suspension characterisation and effectiveness of a variable area orifice

    Science.gov (United States)

    Alonso, A.; Giménez, J. G.; Nieto, J.; Vinolas, J.

    2010-12-01

    The air spring is one of the components that most affects vehicle comfort. This element usually makes up the main part of the secondary suspension, which introduces both stiffness and damping between the bogie and the car body. Therefore, a deep understanding of this element is necessary in order to study the comfort of a vehicle, the influence of different parameters and the ways to improve it. In this work, the effect of the air spring system on comfort is studied. To accomplish this, a typical pneumatic suspension composition is briefly studied as a first step. Then, the test bench developed to characterise air springs is described, presenting experimental results. Correlation of the results with some theoretical models is also addressed. Afterwards, the effect of the air spring system on comfort is analysed, and finally, improvements from introducing a variable area orifice in the pipe that joints the air spring and the surge reservoir are discussed.

  15. 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)

  16. Woodland recovery after suppression of deer: cascade effects for small mammals, wood mice (Apodemus sylvaticus and bank voles (Myodes glareolus.

    Directory of Open Access Journals (Sweden)

    Emma R Bush

    Full Text Available Over the past century, increases in both density and distribution of deer species in the Northern Hemisphere have resulted in major changes in ground flora and undergrowth vegetation of woodland habitats, and consequentially the animal communities that inhabit them. In this study, we tested whether recovery in the vegetative habitat of a woodland due to effective deer management (from a peak of 0.4-1.5 to <0.17 deer per ha had translated to the small mammal community as an example of a higher order cascade effect. We compared deer-free exclosures with neighboring open woodland using capture-mark-recapture (CMR methods to see if the significant difference in bank vole (Myodes glareolus and wood mouse (Apodemus sylvaticus numbers between these environments from 2001-2003 persisted in 2010. Using the multi-state Robust Design method in program MARK we found survival and abundance of both voles and mice to be equivalent between the open woodland and the experimental exclosures with no differences in various metrics of population structure (age structure, sex composition, reproductive activity and individual fitness (weight, although the vole population showed variation both locally and temporally. This suggests that the vegetative habitat--having passed some threshold of complexity due to lowered deer density--has allowed recovery of the small mammal community, although patch dynamics associated with vegetation complexity still remain. We conclude that the response of small mammal communities to environmental disturbance such as intense browsing pressure can be rapidly reversed once the disturbing agent has been removed and the vegetative habitat is allowed to increase in density and complexity, although we encourage caution, as a source/sink dynamic may emerge between old growth patches and the recently disturbed habitat under harsh conditions.

  17. 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.

  18. Modelling of air resistance during drying of wood-chips

    OpenAIRE

    Karaj, S.; Barfuss, Isabel; Schalk, J.; Reisinger, G.; Pude, R.; Müller, Joachim

    2011-01-01

    The objective of this study was to investigate the parameters that affect the drying process of wood chips at low air flow conditions. This objective was determined by measuring the air pressure resistance being produced by wood chips by examining different variables such as: air flow rate, air velocity, wood chip size, bulk density, bulk height and porosity. The air flow resistance was measured inside a 3 meter high cylindrical air duct constructed at University of Hohenheim. Physical proper...

  19. Heat sink effects in variable polarity plasma arc welding

    Science.gov (United States)

    Abdelmessih, Amanie N.

    1991-01-01

    The Space Shuttle External Tank is fabricated by the variable polarity plasma arc (VPPA) welding process. In VPPA welding, a noble gas, usually argon, is directed through an arc to emerge from the torch as a hot plasma jet. This jet is surrounded by a shielding gas, usually helium, to protect the weld from contamination with air. The high velocity, hot plasma jet completely penetrates the workpiece (resembling a line heat source) when operated in the 'keyhole' mode. The metal melts on touching the side of the jet, as the torch travels in the perpendicular direction to the direction of the jet, and melted metal moves around the plasma jet in the keyhole forming a puddle which solidifies behind the jet. Heat sink effects are observed when there are irregularities in the workpiece configuration, especially, if these irregularities are close to the weld bead. These heat sinks affect the geometry of the weld bead, i.e., in extreme cases they could cause defects such as incomplete fusion. Also, different fixtures seem to have varying heat sink effects. The objective of this research is to study the effect of irregularities in workpiece configuration and fixture differences (heat sink effects) on the weld bead geometry with the ultimate objective to compensate for the heat sink effects and achieve a perfect weld. Experiments were performed on different workpiece geometries and compared to approximate models.

  20. Kinetic investigation of wood pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Thurner, F.; Mann, U.; Beck, S. R.

    1980-06-01

    The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.