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Sample records for birch wood xylan

  1. Synthesis and characterization of birch wood xylan succinoylated in 1-n-butyl-3-methylimidazolium chloride

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Plackett, David

    2011-01-01

    analysis of the modified and native xylans showed a slight lowering of thermal stability with functionalization. Contact angle measurements on spin-coated surfaces of modified xylan films showed a significant increase in hydrophobicity with the introduction of the alkenyl-functionalized succinic anhydride...

  2. Properties of plasticized composite films prepared from nanofibrillated cellulose and birch wood xylan

    DEFF Research Database (Denmark)

    Hansen, Natanya Majbritt Louie; Blomfeldt, Thomas O. J.; Hedenqvist, Mikael S.

    2012-01-01

    was combined with nanofibrillated cellulose (NFC) and films were cast with and without glycerol, sorbitol or methoxypolyethylene glycol (MPEG) as plasticizers. Microscopy revealed some NFC agglomeration in the composite films as well as a layered nanocellulose structure. Equilibrium moisture content...... in plasticized films increased with glycerol content but was independent of xylan:NFC ratio in unplasticized films. Sorbitol- and MPEG-plasticized films showed equilibrium moisture contents of approximately 10 wt% independent of plasticizer content. Tensile testing revealed increases in tensile strength...... with increased NFC content in the xylan:NFC composition range from 50:50 to 80:20 and plasticizer addition generally provided less brittle films. The oxygen permeability of unplasticized xylan-NFC films fell into a range which was similar to that for previously measured pure NFC films and was statistically...

  3. Study on the Modification of Bleached Eucalyptus Kraft Pulp Using Birch Xylan

    Science.gov (United States)

    Wenjia Han; Chuanshan Zhao; Thomas Elder; Rendang Yang; Dongho Kim; Yunqiao Pu; Jeffery Hsieh; Arthur J. Ragauskas

    2012-01-01

    In this study, birch xylan was deposited onto elementally chlorine free (ECF) bleached eucalyptus kraft pulp, and the corresponding changes in physical properties were determined. An aqueous 5% birch xylan solution at pH 9 was added to 5 wt% slurry of bleached kraft eucalyptus fibers, with stirring at 70 C for 15 min after which the pH was adjusted to 5–6. The xylan...

  4. Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

    Science.gov (United States)

    Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

    2017-06-01

    High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  5. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    Science.gov (United States)

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. The distribution of lignin in white birch wood as determined by bromination with TEM-EDXA

    International Nuclear Information System (INIS)

    Saka, S.; Goring, D.A.I.

    1988-01-01

    Ultraviolet absorbance and bromine uptake were measured on various morphological regions of birch wood. To facilitate precise comparison, observations were made on identical locations in successive cross sections. From the data, the concentration of lignin and the ratio of the guaiacyl to syringyl residues were determined. The results obtained were then compared with the previous findings from the use of UV microscopy alone

  7. Contamination of pine and birch wood dust with microscopic fungi and determination of its sterol contents.

    Science.gov (United States)

    Stuper-Szablewska, Kinga; Rogoziński, Tomasz; Perkowski, Juliusz

    2017-06-27

    Wood compounds, especially sterols, are connected with the level of contamination with microscopic fungi. Within this study, tests were conducted on wood dust samples collected at various work stations in a pine and birch timber conversion plant. Their contamination with mycobiota was measured as the concentration of ergosterol (ERG) by ultra performance liquid chromatography (UPLC). Another aim of this study was to assess the effect of contamination with microscopic fungi on the sterol contents in wood dusts. Analyses were conducted on five sterols: desmosterol, cholesterol, lanosterol, stigmasterol, and β-sitosterol using UPLC and their presence was confirmed using gas chromatography/mass spectrometry (GC/MS). The results of chemical analyses showed the greatest contamination with mycobiota in birch wood dust. We also observed varied contents of individual sterols depending on the wood dust type. Their highest concentration was detected in birch dust. The discriminant analysis covering all tested compounds as predictors showed complete separation of all tested wood dust types. The greatest discriminatory power was found for stigmasterol, desmosterol, and ergosterol.

  8. Influence of Biomass Pretreatment Process Time on Furfural Extraction from Birch Wood

    Science.gov (United States)

    Brazdausks, Prans; Puke, Maris; Vedernikovs, Nikolajs; Kruma, Irena

    2013-12-01

    Furfural is a biomass derived-chemical that can be used to replace petrochemicals. In this study, dilute sulphuric acid hydrolysis was used for hemicelluloses secession from birch wood. The reaction was investigated at different biomass treatment times (10-90 min, increasing it by 10 min). We found that the greatest amount of furfural 1.4-2.6%, which is 9.7-17.7% from theoretical possible yield, was formed in the first 30 min of the beginning of birch wood pentoses monosaccharide dehydration, but the greatest yield of furfural 10.3%, which is 70.0% from the theoretical yield, can be obtained after 90 min. Given that furfural yield generally does not exceed 50% from the theoretical amount, the result can be considered as very good.

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

    Directory of Open Access Journals (Sweden)

    Vlastimil Borůvka

    2018-04-01

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

  10. Influences of Thermo-Vacuum Treatment on Colors and Chemical Compositions of Alder Birch Wood

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2015-10-01

    Full Text Available With high temperature-heat treatment, the dimensional stability and durability of wood is improved and wood color is darkened as well. In this paper, alder birch wood (Betula alnoides was treated by the Thermo-Vacuum Treatment (TVT. The changes of wood color parameters and the chemical composition were determined by the CIE1976 L*a*b* method and the chemical analysis method, respectively. The results were revealed as follows: (1 A lower value of lightness, L*, and a higher value of total color difference, △E*, were obtained at the higher heat-treatment temperatures and longer treatment time. (2 The higher the heat-treatment temperatures and the longer the heat-treatment times were, the lower the contents of hemicellulose and cellulose were and the higher the content of lignin was. Moreover, Fourier Transform infrared spectroscopy (FTIR analysis demonstrated that the characteristic absorption peaks of cellulose, hemicellulose, and lignin diminished. The acetylation reaction of hemicellulose and the degradation reaction of groups of lignin side chain occurred during TVT. (3 TVT degraded the chemical composition of cell walls, which resulted in further changes of the wood color. A significant correlation existed between the differences of color indices and the differences of the chemical composition after TVT.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  12. Alaska birch for edge-glued panel production—considerations for wood products manufacturers

    Science.gov (United States)

    David. Nicholls

    2010-01-01

    Edge-glued panels could become a natural extension for the birch (Betula papyrifera Marsh.) lumber industry in Alaska, resulting in greater utilization of the birch resource while allowing producers to explore a wider variety of products and markets. Key advantages of edge-glued panel production include the relatively low cost of equipment, the...

  13. Influence of Welding Time on Tensile-Shear Strength of Linear Friction Welded Birch (Betula pendula L. Wood

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    Jussi Ruponen

    2015-04-01

    Full Text Available The purpose of this work was to determine the optimal welding time for linear friction welding of birch (Betula pendula L. wood while keeping the other parameters constant and at similar levels compared to other species in a similar density range. Specimens with dimensions of 20 × 5 × 150 mm3 were welded together, and the influence of welding time (2.5, 3.0, 3.5, and 4.0 s on the mechanical properties of the specimens was determined. The studies included a tensile-shear strength test as well as visual estimation of wood failure percentage (WFP. Additionally, X-ray microtomographic imaging was used to investigate and characterise the bond line properties as a non-destructive testing method. The highest mean tensile-shear strength, 7.9 MPa, was reached with a welding time of 3.5 s. Generally, all four result groups showed high, yet decreasing proportional standard deviations as the welding time increased. X-ray microtomographic images and analysis express the heterogeneity of the weld line clearly as well. According to the averaged group-wise results, WFP and tensile-shear strength correlated positively with an R2 of 0.93. An extrapolation of WFP to 65% totals a tensile-shear strength of 10.6 MPa, corresponding to four common adhesive bonds determined for beech.

  14. Seasonal dynamics of saproxylic beetles (Coleoptera occurring in decaying birch (Betula spp. wood in the Kampinos National Park

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    Sawoniewicz Michał

    2015-09-01

    Full Text Available The aim of the study was to identify the seasonal changes in the number of saproxylic beetles connected with birch in the Kampinos National Park. The research was conducted for 12 consecutive months in research areas representing 10 different site types. The beetles were collected from wood using photoeclectors. The largest number of species was collected in April and the lowest in January. An increase in number occurred during spring and summer months for species associated only with rotting wood, fructifications of tree fungi, the subcortical environment and hollows. In the same period the number of species not associated or potentially associated with decaying trees and wood decreased. During winter months, the differences in the number of trapped specimens were the smallest. The proportion of zoophagous species amongst the collected specimen increased in autumn and winter. The share of saprophagous species was the highest during the summer-autumn period and the share of mycetophages (jointly with myxomycophages was the highest during spring and summer. We distinguished two separate groups of Coleoptera with the first one (‘summer group’ including species trapped during late-spring and summer months, while the second one (‘winter group’ includes species found in autumn, winter and early-spring months. In the ‘summer group’, an average of 55.8 species was trapped each month with 331.2 specimen of Coleoptera, while in the ʻwinter group’ an average of 56.1 species with 228.4 Coleoptera specimen were caught.

  15. Recycling of wood- and peat-ash. A successful way to establish full plant cover and dense birch stand on a cut-away peatland

    Energy Technology Data Exchange (ETDEWEB)

    Huotari, N.

    2012-07-01

    Mechanical harvesting of peat changes the original mire ecosystem completely, and without active measures these areas may remain non-vegetated even for decades. Afforestation is one of the most popular after-use options for cut-away peatlands in Finland since it has both economic and aesthetic values. Recycling of wood-ash as a fertilizer has been studied extensively in peatlands drained for forestry. Wood-ash is reported to promote tree growth in these areas without any significant negative impact to the environment and could, therefore, be a suitable option also on cut-away peatlands. However, the environmental effects of ash-fertilization on cut-away areas and on ground vegetation are not fully understood. The impact of wood- and peat-ash application on the early establishment of ground vegetation and downy birch (Betula pubescens) seedlings and on post-fertilization element concentrations in plants and peat substrate were studied in a cut-away peatland. Six treatments of wood-ash, peat-ash, biotite or Forest PK-fertilizer were replicated in three blocks in different mixtures and quantities corresponding to 50 kg ha-1 of phosphorus. All the fertilizers accelerated the revegetation of the bare peat surface significantly, whereas the establishment of plants in the unfertilized area was non-existent even several years after the peat harvesting had ceased. The most striking difference between the wood- and peat-ash-fertilizers and the commercial Forest PK-fertilizer was the extensive coverage of fire-loving moss species in all the areas where ash was spread. Wood- and peat-ash application also accelerated the germination and early establishment of downy birch seedlings more efficiently than the PK-fertilizer. Ground vegetation proved to be highly important in increasing the early biomass production and carbon sequestration on ash-fertilized cut-away peatland. In addition, the below-ground biomass was equal to the above-ground biomass, or even greater. Both wood- and

  16. Numerical responses of saproxylic beetles to rapid increases in dead wood availability following geometrid moth outbreaks in sub-arctic mountain birch forest.

    Science.gov (United States)

    Vindstad, Ole Petter Laksforsmo; Schultze, Sabrina; Jepsen, Jane Uhd; Biuw, Martin; Kapari, Lauri; Sverdrup-Thygeson, Anne; Ims, Rolf Anker

    2014-01-01

    Saproxylic insects play an important part in decomposing dead wood in healthy forest ecosystems, but little is known about their role in the aftermath of large-scale forest mortality caused by pest insect outbreaks. We used window traps to study short-term changes in the abundance and community structure of saproxylic beetles following extensive mortality of mountain birch in sub-arctic northern Norway caused by an outbreak of geometrid moths. Three to five years after the outbreak, the proportion of obligate saproxylic individuals in the beetle community was roughly 10% higher in forest damaged by the outbreak than in undamaged forest. This was mainly due to two early-successional saproxylic beetle species. Facultative saproxylic beetles showed no consistent differences between damaged and undamaged forest. These findings would suggest a weak numerical response of the saproxylic beetle community to the dead wood left by the outbreak. We suggest that species-specific preferences for certain wood decay stages may limit the number of saproxylic species that respond numerically to an outbreak at a particular time, and that increases in responding species may be constrained by limitations to the amount of dead wood that can be exploited within a given timeframe (i.e. satiation effects). Low diversity of beetle species or slow development of larvae in our cold sub-arctic study region may also limit numerical responses. Our study suggests that saproxylic beetles, owing to weak numerical responses, may so far have played a minor role in decomposing the vast quantities of dead wood left by the moth outbreak.

  17. Numerical responses of saproxylic beetles to rapid increases in dead wood availability following geometrid moth outbreaks in sub-arctic mountain birch forest.

    Directory of Open Access Journals (Sweden)

    Ole Petter Laksforsmo Vindstad

    Full Text Available Saproxylic insects play an important part in decomposing dead wood in healthy forest ecosystems, but little is known about their role in the aftermath of large-scale forest mortality caused by pest insect outbreaks. We used window traps to study short-term changes in the abundance and community structure of saproxylic beetles following extensive mortality of mountain birch in sub-arctic northern Norway caused by an outbreak of geometrid moths. Three to five years after the outbreak, the proportion of obligate saproxylic individuals in the beetle community was roughly 10% higher in forest damaged by the outbreak than in undamaged forest. This was mainly due to two early-successional saproxylic beetle species. Facultative saproxylic beetles showed no consistent differences between damaged and undamaged forest. These findings would suggest a weak numerical response of the saproxylic beetle community to the dead wood left by the outbreak. We suggest that species-specific preferences for certain wood decay stages may limit the number of saproxylic species that respond numerically to an outbreak at a particular time, and that increases in responding species may be constrained by limitations to the amount of dead wood that can be exploited within a given timeframe (i.e. satiation effects. Low diversity of beetle species or slow development of larvae in our cold sub-arctic study region may also limit numerical responses. Our study suggests that saproxylic beetles, owing to weak numerical responses, may so far have played a minor role in decomposing the vast quantities of dead wood left by the moth outbreak.

  18. A new method for the quantification of monosaccharides, uronic acids and oligosaccharides in partially hydrolyzed xylans by HPAEC-UV/VIS.

    Science.gov (United States)

    Lorenz, Dominic; Erasmy, Nicole; Akil, Youssef; Saake, Bodo

    2016-04-20

    A new method for the chemical characterization of xylans is presented, to overcome the difficulties in quantification of 4-O-methyl-α-D-glucuronic acid (meGlcA). In this regard, the hydrolysis behavior of xylans from beech and birch wood was investigated to obtain the optimum conditions for hydrolysis, using sulfuric acid. Due to varying linkage strengths and degradation, no general method for complete hydrolysis can be designed. Therefore, partial hydrolysis was applied, yielding monosaccharides and small meGlcA containing oligosaccharides. For a new method by HPAEC-UV/VIS, these samples were reductively aminated by 2-aminobenzoic acid. By quantification of monosaccharides and oligosaccharides, as well as comparison with borate-HPAEC and (13)C NMR-spectroscopy, we revealed that the concentrations meGlcA are significantly underestimated compared to conventional methods. The detected concentrations are 85.4% (beech) and 76.3% (birch) higher with the new procedure. Furthermore, the quantified concentrations of xylose were 9.3% (beech) and 6.5% (birch) higher by considering the unhydrolyzed oligosaccharides as well. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Effect of wood ash on leaf and shoot anatomy, photosynthesis and carbohydrate concentrations in birch on a cutaway peatland.

    Science.gov (United States)

    Aguraijuja, Karin; Klõšeiko, Jaan; Ots, Katri; Lukjanova, Aljona

    2015-07-01

    Trees in cutaway peatland are growing in difficult conditions. Fertilization with nutrient-rich wood ash helps improve growth conditions. Photosynthesis and carbohydrate concentration along leaf anatomy were studied on plots treated with 10 and 5 t ha(-1) wood ash (WA10 and WA5) and on untreated (Control) plot to explain the physiological background of the differences in tree growth. The leaves from WA10 had the largest leaf area, total thickness, the thickest mesophyll and also significantly larger average values of all anatomical parameters of the shoots. The photosynthetic assimilation was significantly higher on treated plots at 200 and 400 ppm CO2 levels. In leaves on the treated plots, the sucrose concentration was lower while that of starch was higher than in trees on untreated soil. The differences in the maximum photosynthesis were relatively small. At unit ground, the leaf area provided for a wood ash-treated tree an efficient surface for CO2 assimilation, light interception and some starch storage during the growing period.

  20. Birch's Mantle

    Science.gov (United States)

    Anderson, D. L.

    2002-12-01

    Francis Birch's 1952 paper started the sciences of mineral physics and physics of the Earth's interior. Birch stressed the importance of pressure, compressive strain and volume in mantle physics. Although this may seem to be an obvious lesson many modern paradoxes in the internal constitution of the Earth and mantle dynamics can be traced to a lack of appreciation for the role of compression. The effect of pressure on thermal properties such as expansivity can gravitational stratify the Earth irreversibly during accretion and can keep it chemically stratified. The widespread use of the Boussinesq approximation in mantle geodynamics is the antithesis of Birchian physics. Birch pointed out that eclogite was likely to be an important component of the upper mantle. Plate tectonic recycling and the bouyancy of oceanic crust at midmantle depths gives credence to this suggestion. Although peridotite dominates the upper mantle, variations in eclogite-content may be responsible for melting- or fertility-spots. Birch called attention to the Repetti Discontinuity near 900 km depth as an important geodynamic boundary. This may be the chemical interface between the upper and lower mantles. Recent work in geodynamics and seismology has confirmed the importance of this region of the mantle as a possible barrier. Birch regarded the transition region (TR ; 400 to 1000 km ) as the key to many problems in Earth sciences. The TR contains two major discontinuities ( near 410 and 650 km ) and their depths are a good mantle thermometer which is now being exploited to suggest that much of plate tectonics is confined to the upper mantle ( in Birch's terminology, the mantle above 1000 km depth ). The lower mantle is homogeneous and different from the upper mantle. Density and seismic velocity are very insensitive to temperature there, consistent with tomography. A final key to the operation of the mantle is Birch's suggestion that radioactivities were stripped out of the deeper parts of

  1. Changes in birch wood cellulose through the action of sulphuric acid during furfural production. 3. Isolation of cellulose compounds

    Energy Technology Data Exchange (ETDEWEB)

    Roze, I.M.; Vedernikov, N.A.

    1981-01-01

    The effect was studied of temperature (137-167 degrees C) and H/sub 2/SO/sub 4/ concentration (10-90%) in furfural production on the content of cellulose compounds and the degree of (hydrolytic) breakdown of difficultly-hydrolysed polysaccharides in the residual lignocellulose. Increasing temperature reduced cellulose yield and increased polysaccharide breakdown, especially in 10-30% H/sub 2/SO/sub 4/. A higher concentration of the same amount of H/sub 2/SO/sub 4/ reduced polysaccharide breakdown (by reducing the liquid/solid ratio), especially at a higher temperature, thereby enabling more cellulose to be recovered for further processing (e.g. wood hydrolysis). Results suggest that H/sub 2/SO/sub 4/ catalyzes the hydrolysis and dehydration processes differently. (Refs. 6).

  2. Cellulose- and xylan-degrading thermophilic anaerobic bacteria from biocompost.

    Science.gov (United States)

    Sizova, M V; Izquierdo, J A; Panikov, N S; Lynd, L R

    2011-04-01

    Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to a Clostridium clariflavum strain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation.

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

    Science.gov (United States)

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

    2011-07-01

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

  4. Deep Eutectic Solvent Aqueous Solutions as Efficient Media for the Solubilization of Hardwood Xylans.

    Science.gov (United States)

    Morais, Eduarda S; Mendonça, Patrícia V; Coelho, Jorge F J; Freire, Mara G; Freire, Carmen S R; Coutinho, João A P; Silvestre, Armando J D

    2018-02-22

    This work contributes to the development of integrated lignocellulosic-based biorefineries by the pioneering exploitation of hardwood xylans by solubilization and extraction in deep eutectic solvents (DES). DES formed by choline chloride and urea or acetic acid were initially evaluated as solvents for commercial xylan as a model compound. The effects of temperature, molar ratio, and concentration of the DES aqueous solutions were evaluated and optimized by using a response surface methodology. The results obtained demonstrated the potential of these solvents, with 328.23 g L -1 of xylan solubilization using 66.7 wt % DES in water at 80 °C. Furthermore, xylans could be recovered by precipitation from the DES aqueous media in yields above 90 %. The detailed characterization of the xylans recovered after solubilization in aqueous DES demonstrated that 4-O-methyl groups were eliminated from the 4-O-methylglucuronic acids moieties and uronic acids (15 %) were cleaved from the xylan backbone during this process. The similar M w values of both pristine and recovered xylans confirmed the success of the reported procedure. DES recovery in four additional extraction cycles was also demonstrated. Finally, the successful extraction of xylans from Eucalyptus globulus wood by using aqueous solutions of DES was demonstrated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Animal damage to birch

    Science.gov (United States)

    James S. Jordan; Francis M. Rushmore

    1969-01-01

    A relatively few animal species are responsible for most of the reported damage to the birches. White-tailed deer, yellow-bellied sapsuckers, porcupines, moose, and hares are the major animals involved. We will review reports of damage, discuss the underlying causes, and describe possible methods of control. For example, heavy deer browsing that eliminates birch...

  6. Xylan polysaccharides fabricated into nanofibrous substrate for myocardial infarction

    International Nuclear Information System (INIS)

    Venugopal, J.; Rajeswari, R.; Shayanti, M.; Sridhar, R.; Sundarrajan, S.; Balamurugan, R.; Ramakrishna, S.

    2013-01-01

    Myocardial infarction, a main cause of heart failure, leads to loss of cardiac tissue impairment of left ventricular function. Repair of diseased myocardium with in vitro engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for myocardial infarction. We attempted to solve these problems by in vitro study by selecting a plant based polysaccharides beech wood Xylan for the normal functioning of infarcted myocardium. The present study fabricated Xylan based nanofibrous scaffolds cross-linked with glutaraldehyde (Glu) vapors for 24 h, 48 h and 1% Glu blended fibers for the culture of neonatal rat cardiac cells for myocardial infarction. These nanofibers were characterized by SEM, FT-IR, tensile testing and cell culture studies for the normal expression of cardiac proteins. The observed results showed that the Xylan/polyvinyl alcohol (PVA) 24 h Glu vapor cross-linked nanofibers (427 nm) having mechanical strength of 2.43 MPa and Young modulus of 3.74 MPa are suitable for the culture of cardiac cells. Cardiac cells proliferation increased only by 11% in Xylan/PVA 24 h Glu cross-linked nanofibers compared to control tissue culture plate (TCP). The normal cardiac cell morphology was observed in 24 h cross-linked Xylan/PVA nanofibers but 48 h cross-linked fibers cell morphology was changed to flattened and elongated on the fibrous surfaces. Confocal analysis for cardiac expression proteins actinin, connexin 43 was observed normally in 24 h Glu cross-linked nanofibers compared to all other nanofibrous scaffolds. The fabricated Xylan/PVA nanofibrous scaffold may have good potential for the normal functioning of infarcted myocardium. - Highlights: ► Fabrication of polysaccharides Xylan/PVA nanofibers for cardiac tissue engineering ► Nanofibers characterized by SEM, FT-IR, tensile testing and cell culture studies ► Isolation of cardiac cells and cultured on Xylan/PVA nanofibrous scaffolds ► Cultured cells on 24 h Glu cross

  7. Xylan polysaccharides fabricated into nanofibrous substrate for myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Venugopal, J., E-mail: nnijrv@nus.edu.sg; Rajeswari, R.; Shayanti, M.; Sridhar, R.; Sundarrajan, S.; Balamurugan, R.; Ramakrishna, S.

    2013-04-01

    Myocardial infarction, a main cause of heart failure, leads to loss of cardiac tissue impairment of left ventricular function. Repair of diseased myocardium with in vitro engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for myocardial infarction. We attempted to solve these problems by in vitro study by selecting a plant based polysaccharides beech wood Xylan for the normal functioning of infarcted myocardium. The present study fabricated Xylan based nanofibrous scaffolds cross-linked with glutaraldehyde (Glu) vapors for 24 h, 48 h and 1% Glu blended fibers for the culture of neonatal rat cardiac cells for myocardial infarction. These nanofibers were characterized by SEM, FT-IR, tensile testing and cell culture studies for the normal expression of cardiac proteins. The observed results showed that the Xylan/polyvinyl alcohol (PVA) 24 h Glu vapor cross-linked nanofibers (427 nm) having mechanical strength of 2.43 MPa and Young modulus of 3.74 MPa are suitable for the culture of cardiac cells. Cardiac cells proliferation increased only by 11% in Xylan/PVA 24 h Glu cross-linked nanofibers compared to control tissue culture plate (TCP). The normal cardiac cell morphology was observed in 24 h cross-linked Xylan/PVA nanofibers but 48 h cross-linked fibers cell morphology was changed to flattened and elongated on the fibrous surfaces. Confocal analysis for cardiac expression proteins actinin, connexin 43 was observed normally in 24 h Glu cross-linked nanofibers compared to all other nanofibrous scaffolds. The fabricated Xylan/PVA nanofibrous scaffold may have good potential for the normal functioning of infarcted myocardium. - Highlights: ► Fabrication of polysaccharides Xylan/PVA nanofibers for cardiac tissue engineering ► Nanofibers characterized by SEM, FT-IR, tensile testing and cell culture studies ► Isolation of cardiac cells and cultured on Xylan/PVA nanofibrous scaffolds ► Cultured cells on 24 h Glu cross

  8. Wood

    DEFF Research Database (Denmark)

    Unterrainer, Walter

    2014-01-01

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

  9. Experimental Study of Impregnation Birch and Aspen Samples

    Directory of Open Access Journals (Sweden)

    Igor Vladislavovich Grigorev

    2014-10-01

    Full Text Available An experimental study of wood impregnation was implemented by applying centrifugal methods. The impregnants were a 10% aqueous solution of potassium chloride and a 2% aqueous solution of borax. Birch (Betula pendula and aspen (Populus tremula wood samples in different moisture content were tested. The impregnation time in the centrifugal device were 30 seconds repeated 21 times, and the samples were measured after every 30 seconds. The experimental results were fitted to a nonlinear filtration law, which indicated that the centrifugal wood impregnation was dependent on wood species, wood moisture, rotational speed, and radius. Determination of rotational speed and centrifuge radius for impregnating aspen and birch at varying lengths and humidity under conditions of the nonlinear impregnant filtration law can be done using the example charts that were developed and presented in this study.

  10. Reducing the heterogeneity of xylan through processing.

    Science.gov (United States)

    Zhang, Wei; Johnson, Amanda M; Barone, Justin R; Renneckar, Scott

    2016-10-05

    Glycerol thermal processing (GTP) of hardwood biomass at temperatures between 200 and 240°C facilitated stepwise biopolymer fractionation, while limiting significant degradation of the major hemicellulose, glucuronoxylan, into water-extractable oligosaccharides. After GTP pretreatment and sequential water and organic solvent extraction, up to 80% of the initial xylan remained in the pretreated biomass. The majority of the xylan from GTP pretreated and water/solvent extracted biomass was removed using a mild alkali extraction and the composition was compared to xylan directly isolated from untreated hardwood. The precipitated xylan from the neutralized alkaline filtrate was isolated as a water insoluble xylan portion (WIX). The residual xylan dissolved in the neutralized filtrate was precipitated in cold methanol and recovered as the water soluble xylan portion (WSX). Results showed that xylan in WIX was in a polymeric form with a number average degree of polymerization (DP) over 100, whereas the WSX had a much lower average DP of 27 (ca) and contained more substitution. As the processing severity increased during GTP pretreatment, the proportion of WIX increased and the purity of the xylan within the WIX sample reached 84% based on compositional analysis. FT-IR analysis of WIX revealed that xylan isolated after GTP contained peaks related to a reduced carbonyl signal compared to the control. Furthermore, crude WSX contained less xylan with more lignin contamination at severe GTP conditions. The recovery of the xylan in two portions facilitated a preferential purification strategy resulting in WIX with an extremely narrow polydispersity index between 1.1 and 1.25, dependent upon the GTP severity. This study provided insight into fractionating higher molecular weight xylan that may serve value-added applications such as healthcare materials and advanced packaging. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Birch symposium proceedings

    Science.gov (United States)

    W.T. Doolittle; P.E. Bruns

    1969-01-01

    This symposium on yellow and paper birch is the third in a series of meetings devoted to discussion of our fine hardwood timber species. The first meeting, held at Carbondale, Illinois, in 1966, dealt with black walnut. The second, held at Houghton, Michigan, in 1968, dealt with sugar maple. The purpose of this third meeting is to bring together our present knowledge...

  12. Winter Birch Trees

    Science.gov (United States)

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  13. 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...

  14. Probing Xylan-Specific Raman Bands for Label-Free Imaging Xylan in Plant Cell Wall

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yining; Yarbrough, John M.; Mittal, Ashutosh; Tucker, Melvin P.; Vinzant, Todd; Himmel, Michael E.

    2015-06-15

    Xylan constitutes a significant portion of biomass (e.g. 22% in corn stover used in this study). Xylan is also an important source of carbohydrates, besides cellulose, for renewable and sustainable energy applications. Currently used method for the localization of xylan in biomass is to use fluorescence confocal microscope to image the fluorescent dye labeled monoclonal antibody that specifically binds to xylan. With the rapid adoption of the Raman-based label-free chemical imaging techniques in biology, identifying Raman bands that are unique to xylan would be critical for the implementation of the above label-free techniques for in situ xylan imaging. Unlike lignin and cellulose that have long be assigned fingerprint Raman bands, specific Raman bands for xylan remain unclear. The major challenge is the cellulose in plant cell wall, which has chemical units highly similar to that of xylan. Here we report using xylanase to specifically remove xylan from feedstock. Under various degree of xylan removal, with minimum impact to other major cell wall components, i.e. lignin and cellulose, we have identified Raman bands that could be further tested for chemical imaging of xylan in biomass in situ.

  15. Biomimetic Inks Based on Cellulose Nanofibrils and Cross-Linkable Xylans for 3D Printing.

    Science.gov (United States)

    Markstedt, Kajsa; Escalante, Alfredo; Toriz, Guillermo; Gatenholm, Paul

    2017-11-22

    This paper presents a sustainable all-wood-based ink which can be used for 3D printing of constructs for a large variety of applications such as clothes, furniture, electronics, and health care products with a customized design and versatile gel properties. The 3D printing technologies where the material is dispensed in the form of liquids, so called inks, have proven suitable for 3D printing dispersions of cellulose nanofibrils (CNFs) because of their unique shear thinning properties. In this study, novel inks were developed with a biomimetic approach where the structural properties of cellulose and the cross-linking function of hemicelluloses that are found in the plant cell wall were utilized. The CNF was mixed with xylan, a hemicellulose extracted from spruce, to introduce cross-linking properties which are essential for the final stability of the printed ink. For xylan to be cross-linkable, it was functionalized with tyramine at different degrees. Evaluation of different ink compositions by rheology measurements and 3D printing tests showed that the degree of tyramine substitution and the ratio of CNFs to xylan-tyramine in the prepared inks influenced the printability and cross-linking density. Both two-layered gridded structures and more complex 3D constructs were printed. Similarly to conventional composites, the interactions between the components and their miscibility are important for the stability of the printed and cross-linked ink. Thus, the influence of tyramine on the adsorption of xylan to cellulose was studied with a quartz crystal microbalance to verify that the functionalization had little influence on xylan's adsorption to cellulose. Utilizing xylan-tyramine in the CNF dispersions resulted in all-wood-based inks which after 3D printing can be cross-linked to form freestanding gels while at the same time, the excellent printing properties of CNFs remain intact.

  16. Down-Regulation of PoGT47C Expression in Poplar Results in a Reduced Glucuronoxylan Content and an Increased Wood Digestibility by Cellulase

    Science.gov (United States)

    Xylan is the second most abundant polysaccharide in dicot wood. Unraveling the biosynthetic pathway of xylan is important not only for our understanding of the process of wood formation but also for our rational engineering of wood for biofuel production. Although several glycosy...

  17. Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films

    Czech Academy of Sciences Publication Activity Database

    Šimkovic, I.; Kelnar, Ivan; Uhliariková, I.; Mendichi, R.; Mandalika, A.; Elder, T.

    2014-01-01

    Roč. 110, 22 September (2014), s. 464-471 ISSN 0144-8617 Institutional support: RVO:61389013 Keywords : xylan * films * properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.074, year: 2014

  18. Structural analysis of heat-treated birch (Betule papyrifera) surface during artificial weathering

    International Nuclear Information System (INIS)

    Huang Xianai; Kocaefe, Duygu; Kocaefe, Yasar; Boluk, Yaman; Krause, Cornélia

    2013-01-01

    Highlights: ► Investigate detailed structural changes of heat-treated wood due to weathering. ► Identify connection between physical structural changes and chemical degradation. ► Study effect of heat treatment conditions on weathering degradation process. - Abstract: Effect of artificial weathering on the surface structural changes of birch (Betule papyrifera) wood, heat-treated to different temperatures, was studied using the fluorescence microscopy and the scanning electron microscopy (SEM). Changes in the chemical structure of wood components were analyzed by FTIR in order to understand the mechanism of degradation taking place due to heat treatment and artificial weathering. The results are compared with those of the untreated (kiln-dried) birch. The SEM analysis results show that the effect of weathering on the cell wall of the untreated birch surface is more than that of heat-treated samples. The FTIR spectroscopy results indicate that lignin is the most sensitive component of heat-treated birch to the weathering degradation process. Elimination of the amorphous and highly crystallised cellulose is observed for both heat-treated and untreated wood during weathering. It is also observed that heat treatment increases the lignin and crystallised cellulose contents, which to some extent protects heat-treated birch against degradation due to weathering.

  19. The influence of log soaking temperature on surface quality and integrity performance of birch (Betula pendula Roth) veneer

    Science.gov (United States)

    Anti Rohumaa; Toni Antikainen; Christopher G. Hunt; Charles R. Frihart; Mark Hughes

    2016-01-01

    Wood material surface properties play an important role in adhesive bond formation and performance. In the present study, a test method was developed to evaluate the integrity of the wood surface, and the results were used to understand bond performance. Materials used were rotary cut birch (Betula pendula Roth) veneers, produced from logs soaked at 20 or 70 °C prior...

  20. Structural differences of xylans affect their interaction with cellulose

    NARCIS (Netherlands)

    Kabel, M.A.; Borne, van den H.; Vincken, J.P.; Voragen, A.G.J.; Schols, H.A.

    2007-01-01

    The affinity of xylan to cellulose is an important aspect of many industrial processes, e.g. production of cellulose, paper making and bio-ethanol production. However, little is known about the adsorption of structurally different xylans to cellulose. Therefore, the adsorption of various xylans to

  1. Enzymatic deconstruction of xylan for biofuel production

    Science.gov (United States)

    DODD, DYLAN; CANN, ISAAC K. O.

    2010-01-01

    The combustion of fossil-derived fuels has a significant impact on atmospheric carbon dioxide (CO2) levels and correspondingly is an important contributor to anthropogenic global climate change. Plants have evolved photosynthetic mechanisms in which solar energy is used to fix CO2 into carbohydrates. Thus, combustion of biofuels, derived from plant biomass, can be considered a potentially carbon neutral process. One of the major limitations for efficient conversion of plant biomass to biofuels is the recalcitrant nature of the plant cell wall, which is composed mostly of lignocellulosic materials (lignin, cellulose, and hemicellulose). The heteropolymer xylan represents the most abundant hemicellulosic polysaccharide and is composed primarily of xylose, arabinose, and glucuronic acid. Microbes have evolved a plethora of enzymatic strategies for hydrolyzing xylan into its constituent sugars for subsequent fermentation to biofuels. Therefore, microorganisms are considered an important source of biocatalysts in the emerging biofuel industry. To produce an optimized enzymatic cocktail for xylan deconstruction, it will be valuable to gain insight at the molecular level of the chemical linkages and the mechanisms by which these enzymes recognize their substrates and catalyze their reactions. Recent advances in genomics, proteomics, and structural biology have revolutionized our understanding of the microbial xylanolytic enzymes. This review focuses on current understanding of the molecular basis for substrate specificity and catalysis by enzymes involved in xylan deconstruction. PMID:20431716

  2. Carboxymethylated-, hydroxypropylsulfonated- and quaternized xylan derivative films

    Science.gov (United States)

    Ivan Simkovic; Ivan Kelnar; Iveta Uhliarikova; Raniero Mdndichi; Anurag Mandalika; Thomas Elder

    2014-01-01

    Under alkaline/water conditions carboxymethyl, 2-hydroxypropylsulfonate and trimethylammonium-2-hydroxypropyl groups were introduced into xylan in one step with the goal to prepare film specimens. The materials were characterized by NMR, SEC-MALS, TG/DTG/DTA, AFM and mechanical testing. The properties of triple, double and mono-substituted materials were compared. The...

  3. Maillard reaction products from chitosan-xylan ionic liquid solution.

    Science.gov (United States)

    Luo, Yuqiong; Ling, Yunzhi; Wang, Xiaoying; Han, Yang; Zeng, Xianjie; Sun, Runcang

    2013-10-15

    A facile method is reported to prepare Maillard reaction products (MRPs) from chitosan and xylan in co-solvent ionic liquid. UV absorbance and fluorescence changes were regarded as indicators of the occurrence of Maillard reaction. FT-IR, NMR, XRD and TG were used to investigate the structure of chitosan-xylan conjugate. The results revealed that when chitosan reacted with xylan in ionic liquid, the hydrogen bonds in chitosan were destroyed, the facts resulted in the formation of chitosan-xylan MRPs. Moreover, when the mass ratio of chitosan to xylan was 1:1, the Maillard reaction proceeded easily. In addition, relatively high antioxidant property was also noted for the chitosan-xylan conjugate with mass ratio 1:1. So the obtained chitosan-xylan MRP is a promising antioxidant agent for food industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Effect of acetyl groups of wood on furfural preparation

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-01-01

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

  5. Efficacy of recombinant birch pollen vaccine for the treatment of birch-allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Pauli, Gabrielle; Larsen, Tina H; Rak, Sabina

    2008-01-01

    BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter, randomi......-treated group. CONCLUSION: The rBet v 1-based vaccine was safe and effective in treating birch pollen allergy, and induced a highly specific immune response.......BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter......, randomized, double-blind, placebo-controlled trial was undertaken to compare the following 3 vaccines in 134 adults with birch pollen allergy: recombinant birch pollen allergen vaccine (rBet v 1a), licensed birch pollen extract, natural purified birch pollen allergen (nBet v 1), and placebo. Patients...

  6. Acute toxicity of birch tar oil on aquatic organisms

    Directory of Open Access Journals (Sweden)

    M. HAGNER

    2008-12-01

    Full Text Available Birch tar oil (BTO is a by-product of processing birch wood in a pyrolysis system. Accumulating evidence suggests the suitability of BTO as a biocide or repellent in terrestrial environments for the control of weeds, insects, molluscs and rodents. Once applied as biocide, BTO may end up, either through run-off or leaching, in aquatic systems and may have adverse effects on non-target organisms. As very little is known about the toxicity of BTO to aquatic organisms, the present study investigated acute toxicity (LC50/EC50 of BTO for eight aquatic organisms. Bioassays with the Asellus aquaticus (crustacean, Lumbriculus variegatus (oligochaeta worm, Daphnia magna (crustacean, Lymnea sp. (mollusc, Lemna minor (vascular plant, Danio rerio (fish, Scenedesmus gracilis (algae, and Vibrio fischeri (bacterium were performed according to ISO, OECD or USEPA-guidelines. The results indicated that BTO was practically nontoxic to most aquatic organisms as the median effective BTO concentrations against most organisms were >150 mg L-1. In conclusion, our toxicity tests showed that aquatic organisms are to some extent, invariably sensitive to birch tar oil, but suggest that BTO does not pose a severe hazard to aquatic biota. We deduce that, unless BTOs are not applied in the immediate vicinity of water bodies, no special precaution is required.;

  7. Three novel rice genes closely related to the Arabidopsis IRX9, IRX9L, and IRX14 genes and their roles in xylan biosynthesis

    Directory of Open Access Journals (Sweden)

    Dawn eChiniquy

    2013-04-01

    Full Text Available Xylan is the second most abundant polysaccharide on Earth, and represents a major component of both dicot wood and the cell walls of grasses. Much knowledge has been gained from studies of xylan biosynthesis in the model plant, Arabidopsis. In particular, the irregular xylem (irx mutants, named for their collapsed xylem cells, have been essential in gaining a greater understanding of the genes involved in xylan biosynthesis. In contrast, xylan biosynthesis in grass cell walls is poorly understood. We identified three rice genes Os07g49370 (OsIRX9, Os01g48440 (OsIRX9L, and Os06g47340 (OsIRX14, from glycosyltransferase family 43 as putative orthologs to the putative β-1,4-xylan backbone elongating Arabidopsis IRX9, IRX9L, and IRX14 genes, respectively. We demonstrate that the overexpression of the closely related rice genes, in full or partly complement the two well-characterized Arabidopsis irregular xylem (irx mutants: irx9 and irx14. Complementation was assessed by measuring dwarfed phenotypes, irregular xylem cells in stem cross sections, xylose content of stems, xylosyltransferase activity of stems, and stem strength. The expression of OsIRX9 in the irx9 mutant resulted in xylosyltransferase activity of stems that was over double that of wild type plants, and the stem strength of this line increased to 124% above that of wild type. Taken together, our results suggest that OsIRX9/OsIRX9L, and OsIRX14, have similar functions to the Arabidopsis IRX9 and IRX14 genes, respectively. Furthermore, our expression data indicate that OsIRX9 and OsIRX9L may function in building the xylan backbone in the secondary and primary cell walls, respectively. Our results provide insight into xylan biosynthesis in rice and how expression of a xylan synthesis gene may be modified to increase stem strength.

  8. Silvical characteristics of yellow birch (Betula alleghaniensis)

    Science.gov (United States)

    Adrian M. Gilbert

    1960-01-01

    Of the birches in the Northeast, the yellow birch is the elite species, by far the most valuable as a timber tree. More than that, it is one of the largest deciduous trees of northeastern America. It may reach 100 feet in height and more than 3 feet in diameter, and may live to 300 years of age. Pioneers told tales of the gigantic yellow birches they saw.

  9. Proteomic analysis of the major birch allergen Bet v 1 predicts allergenicity for 15 birch species

    NARCIS (Netherlands)

    Schenk, M.F.; Cordewener, J.H.G.; America, A.H.P.; Peters, J.; Smulders, M.J.M.; Gilissen, L.J.W.J.

    2011-01-01

    Pollen of the European and Asian white birch (Betula pendula and B. platyphylla) causes hay fever in humans. The allergenic potency of other birch species is largely unknown. To identify birch trees with a reduced allergenicity, we assessed the immunochemical characteristics of 15 species and two

  10. Ecological and phytopathological status of birch stands on the territory of Krasnoyarsk group of districts

    Directory of Open Access Journals (Sweden)

    A. I. Tatarintsev

    2015-04-01

    Full Text Available According to inspection data, the health and vital status of birch (Betula pendula Roth. stands in Krasnoyarsk group of lands (southern part of Central Siberia were estimated (established as satisfactory in general; about half of birch stands near urbanized areas were weakened. The condition of stands decreased significantly with increased recreation use, the effect of technogenic pollution was negligible. The most valuable (important representatives of pathogenic biota identified on birch trees were infestations of necrotic cancer and rot diseases. In birch stands the bacterial dropsy was found to be widespread (agent of infection – Erwinia multivora Scz.-Parf, occurrence of the disease ranged from a single ill tree up to 10–38 % of the stands. The birch stands in taiga areas were affected to a greater extent than in forest-steppe; there were high yield class stands on moist soils. Prevalence of bacteriosis rose with increasing stand age and density and not dependent on recreation use level. Trees with dropsy are dead in fact or potentially. In taiga birch forests the infection and rot of roots was caused by honey agaric (Armillaria mellea sensu lato, that lead to single or, rarely, group tree drying and the fungus usually eliminated already weakened trees. Wood biomass was destroyed by complex of aphyllophorous Hymenomycetes, their hemiparasitic species caused stem rots that decreased stand marketability and also resulted in rot-realated wind-break accumulation. Occurrence of rot was significantly higher in second growth birch stands, possibly above 20 %; the relationship between rot prevalence and forest assessment was not revealed.

  11. Wood for sound.

    Science.gov (United States)

    Wegst, Ulrike G K

    2006-10-01

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

  12. Interspecific variation in resistance of Asian, European, and North American birches (Betula spp.) to bronze birch borer (Coleoptera: Buprestidae).

    Science.gov (United States)

    Nielsen, David G; Muilenburg, Vanessa L; Herms, Daniel A

    2011-06-01

    Bronze birch borer (Agrilus anxius Gory) is the key pest of birches (Betula spp.) in North America, several of which have been recommended for ornamental landscapes based on anecdotal reports of borer resistance that had not been confirmed experimentally. In a 20-yr common garden experiment initiated in 1979 in Ohio, North American birch species, including paper birch (Betula papyrifera Marshall), 'Whitespire' gray birch (Betula populifolia Marshall), and river birch (Betula nigra L.), were much more resistant to bronze birch borer than species indigenous to Europe and Asia, including European white birch (Betula pendula Roth), downy birch (Betula pubescens Ehrh.), monarch birch (Betula maximowicziana Regel), and Szechuan white birch (Betula szechuanica Jansson). Within 8 yr of planting, every European white, downy, and Szechuan birch had been colonized and killed, although 100% of monarch birch had been colonized and 88% of these plants were killed after nine years. Conversely, 97% of river birch, 76% of paper birch, and 73% Whitespire gray birch were alive 20 yr after planting, and river birch showed no evidence of colonization. This pattern is consistent with biogeographic theory of plant defense: North American birch species that share a coevolutionary history with bronze birch borer were much more resistant than naïve hosts endemic to Europe and Asia, possibly by virtue of evolution of targeted defenses. This information suggests that if bronze birch borer were introduced to Europe or Asia, it could threaten its hosts there on a continental scale. This study also exposed limitations of anecdotal observation as evidence of host plant resistance.

  13. Paper birch decline in the Niobrara River Valley, Nebraska: Weather, microclimate, and birch stand conditions

    Science.gov (United States)

    Stroh, Esther D.; Miller, Joel P.

    2009-01-01

    The Niobrara River Valley in north-central Nebraska supports scattered stands of paper birch (Betula papyrifera Marsh), a species more typical of boreal forests. These birch stands are considered to be relictual populations that have persisted since the end of the Wisconsin glaciation, when regional flora was more boreal in nature (Wright 1970, Kaul and others, 1988). Dieback of canopy-sized birch has been observed throughout the Niobrara Valley in recent years, although no onset dates are documented. The current dieback event probably started around or after the early 1980’s. The study objectives were to understand microclimatic conditions in birch stands relative to nearby weather stations and historic weather conditions, and to assess current health conditions of individual birch trees. Temperature was measured every half-hour from June 2005 through October 2007 in 12 birch stands and individual birch tree health was measured as expressed by percent living canopy in these and 13 additional stands in spring 2006 and 2007. Birch site microclimate was compared to data from a National Weather Service station in Valentine, Nebraska, and to an automated weather station at The Nature Conservancy Niobrara Valley Preserve 24 kilometers north of Johnstown, Nebraska. Historic weather data from the Valentine station and another National Weather Service Station at Ainsworth, Nebraska, were used to reconstruct minimum and maximum temperature at The Nature Conservancy and one microclimate monitoring station using Kalman filtering and smoothing algorithms. Birch stand microclimate differed from local weather stations as well as among stands. Birch health was associated with annual minimum temperature regimes; those stands whose annual daily minimum temperature regimes were most like The Nature Conservancy station contained smaller proportions of living trees. Frequency of freeze/thaw conditions capable of inducing rootlet injury and subsequent crown dieback significantly have

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

    DEFF Research Database (Denmark)

    Bjørkmann, Anders; Salmén, Lennart

    2000-01-01

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

  15. Wood : adhesives

    Science.gov (United States)

    A.H. Conner

    2001-01-01

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

  16. Some Physical and Mechanical Properties of African Birch ...

    African Journals Online (AJOL)

    PROF HORSFALL

    Also, strength properties of African birch timber perpendicular to grain ... Air dried African birch (Anogeissus leiocarpus) ..... Forest Product Research Labouratory. ... America. 001 – 589. Ikram Mohamed, EE; Abdel Khalig, M; Hiba, AA;. Saad ...

  17. Christian Birch - den korrupte konferensråd

    DEFF Research Database (Denmark)

    Jensen, Mette Frisk

    2005-01-01

      http://www.sidensaxo.dk/fileadmin/saxo-abstract-uploads/christian_birch_den_korrupte_konferensraad_2005_3.pdf......  http://www.sidensaxo.dk/fileadmin/saxo-abstract-uploads/christian_birch_den_korrupte_konferensraad_2005_3.pdf...

  18. Hydrolysis kinetics of tulip tree xylan in hot compressed water.

    Science.gov (United States)

    Yoon, Junho; Lee, Hun Wook; Sim, Seungjae; Myint, Aye Aye; Park, Hee Jeong; Lee, Youn-Woo

    2016-08-01

    Lignocellulosic biomass, a promising renewable resource, can be converted into numerous valuable chemicals post enzymatic saccharification. However, the efficacy of enzymatic saccharification of lignocellulosic biomass is low; therefore, pretreatment is necessary to improve the efficiency. Here, a kinetic analysis was carried out on xylan hydrolysis, after hot compressed water pretreatment of the lignocellulosic biomass conducted at 180-220°C for 5-30min, and on subsequent xylooligosaccharide hydrolysis. The weight ratio of fast-reacting xylan to slow-reacting xylan was 5.25 in tulip tree. Our kinetic results were applied to three different reaction systems to improve the pretreatment efficiency. We found that semi-continuous reactor is promising. Lower reaction temperatures and shorter space times in semi-continuous reactor are recommended for improving xylan conversion and xylooligosaccharide yield. In the theoretical calculation, 95% of xylooligosaccharide yield and xylan conversion were achieved simultaneously with high selectivity (desired product/undesired product) of 100 or more. Copyright © 2016. Published by Elsevier Ltd.

  19. Asymptomatic skin sensitization to birch predicts later development of birch pollen allergy in adults

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, Lars K; Malling, Hans-Jørgen

    2003-01-01

    = 6) were followed through use of daily diary cards during 3 consecutive birch pollen seasons. At inclusion and at the 3-year follow-up visit, conjunctival and nasal challenges, intradermal late-phase reaction evaluation, and measurement of specific IgE were performed. RESULTS: Asymptomatic sensitized...... a clinical characterization of skin test-positive subjects without symptoms and to ascertain the predictive values of common allergologic tests. METHODS: Asymptomatic adults with positive skin prick test results for birch (n = 15), nonatopic control subjects (n = 25), and birch pollen-allergic patients (n...

  20. The influence of felling season and log-soaking temperature on the wetting and phenol formaldehyde adhesive bonding characteristics of birch veneer

    Science.gov (United States)

    Anti Rohumaa; Christopher G. Hunt; Charles R. Frihart; Pekka Saranpää; Martin Ohlmeyer; Mark Hughes

    2014-01-01

    Most adhesive studies employing wood veneer as the substrate assume that it is a relatively uniform material if wood species and veneer thickness are constant. In the present study, veneers from rotary cut birch (Betula pendula Roth) were produced from logs harvested in spring, autumn and winter, and soaked at 20°C and 70°C prior to peeling. Firstly...

  1. Rapid Crustal Uplift at Birch Bay, Washington

    Science.gov (United States)

    Sherrod, B. L.; Kelsey, H. M.; Blakely, R. J.

    2010-12-01

    Geomorphology and coastal marsh stratigraphy suggest late Holocene uplift of the shoreline at Birch Bay, located northwest of Bellingham, Washington, during an earthquake on a shallow fault. LiDAR images show a raised, late Holocene shoreline along Birch Bay, with ~1 m of elevation difference between the modern shoreline and the inferred paleoshoreline. Commercial seismic reflection images reveal an anticline in Tertiary and possibly Quaternary deposits underlying Birch Bay. NW-trending magnetic anomalies are likely associated with the Birch Bay anticline and other nearby structures. Taken together, the geophysical data and lidar images suggest uplift of young deposits along a NW-trending blind reverse fault. Stratigraphy from Terrell Creek marsh, located just south of Birch Bay, shows freshwater peat buried by lower intertidal muds, indicating local submergence ~1300 yr BP. Stratigraphy of a 70-cm sediment core from Birch Bay marsh, sitting astride the anticline imaged with seismic reflection data, shows mud buried by detrital peat. One radiocarbon age from the core places the abrupt change from mud to peat prior to 1520-1700 yr BP. We divide fossil diatom assemblages straddling the mud-peat contact at Birch Bay into three zones. The oldest zone consists primarily of intertidal and marine diatoms, dominated by Paralia sulcata, Scoleoneis tumida, Grammataphora oceanica, and Gyrosigma balticum. An intermediate zone, beginning at the sharp contact between mud and overlying peat, consists of a mixture of brackish marsh and freshwater species, dominated by Diploneis interrupta, with lesser amounts of Aulacoseira sp., Pinnularia viridis, Eunotia pectinalis, and Paralia sulcata. A third and youngest zone lies in the upper half of the peat and is dominated by poorly preserved freshwater diatoms, mostly Aulacoseira cf. crassapuntata, Pinnularia viridis, P. maior, Eunotia pectinalis, and E. praerupta. Paleoecological inferences, based on distributions of modern diatoms

  2. Nanocomposite film prepared by depositing xylan on cellulose nanowhiskers matrix

    Science.gov (United States)

    Qining Sun; Anurag Mandalika; Thomas Elder; Sandeep S. Nair; Xianzhi Meng; Fang Huang; Art J. Ragauskas

    2014-01-01

    Novel bionanocomposite films have been prepared by depositing xylan onto cellulose nanowhiskers through a pH adjustment. Analysis of strength properties, water vapour transmission, transparency, surface morphology and thermal decomposition showed the enhancement of film performance. This provides a new green route to the utilization of biomass for sustainable...

  3. Characterization and mode of action of two acetyl xylan esterases from Chrysosporium lucknowense C1 active towards acetylated xylans

    NARCIS (Netherlands)

    Pouvreau, L.A.M.; Jonathan, M.C.; Kabel, M.A.; Hinz, S.W.A.; Gruppen, H.; Schols, H.A.

    2011-01-01

    Two novel acetyl xylan esterases, Axe2 and Axe3, from Chrysosporium lucknowense (C1), belonging to the carbohydrate esterase families 5 and 1, respectively, were purified and biochemically characterized. Axe2 and Axe3 are able to hydrolyze acetyl groups both from simple acetylated

  4. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches

    International Nuclear Information System (INIS)

    Manninen, S.; Huttunen, S.; Vanhatalo, M.; Pakonen, T.; Haemaelaeinen, A.

    2009-01-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O 3 ) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O 3 , i.e. O 3 levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O 3 and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels. - Northern birches are responsive to ambient ozone levels.

  5. Reconstitution of a thermostable xylan-degrading enzyme mixture from the bacterium Caldicellulosiruptor bescii.

    Science.gov (United States)

    Su, Xiaoyun; Han, Yejun; Dodd, Dylan; Moon, Young Hwan; Yoshida, Shosuke; Mackie, Roderick I; Cann, Isaac K O

    2013-03-01

    Xylose, the major constituent of xylans, as well as the side chain sugars, such as arabinose, can be metabolized by engineered yeasts into ethanol. Therefore, xylan-degrading enzymes that efficiently hydrolyze xylans will add value to cellulases used in hydrolysis of plant cell wall polysaccharides for conversion to biofuels. Heterogeneous xylan is a complex substrate, and it requires multiple enzymes to release its constituent sugars. However, the components of xylan-degrading enzymes are often individually characterized, leading to a dearth of research that analyzes synergistic actions of the components of xylan-degrading enzymes. In the present report, six genes predicted to encode components of the xylan-degrading enzymes of the thermophilic bacterium Caldicellulosiruptor bescii were expressed in Escherichia coli, and the recombinant proteins were investigated as individual enzymes and also as a xylan-degrading enzyme cocktail. Most of the component enzymes of the xylan-degrading enzyme mixture had similar optimal pH (5.5 to ∼6.5) and temperature (75 to ∼90°C), and this facilitated their investigation as an enzyme cocktail for deconstruction of xylans. The core enzymes (two endoxylanases and a β-xylosidase) exhibited high turnover numbers during catalysis, with the two endoxylanases yielding estimated k(cat) values of ∼8,000 and ∼4,500 s(-1), respectively, on soluble wheat arabinoxylan. Addition of side chain-cleaving enzymes to the core enzymes increased depolymerization of a more complex model substrate, oat spelt xylan. The C. bescii xylan-degrading enzyme mixture effectively hydrolyzes xylan at 65 to 80°C and can serve as a basal mixture for deconstruction of xylans in bioenergy feedstock at high temperatures.

  6. Selection and production of insoluble xylan hydrolyzing enzyme by ...

    African Journals Online (AJOL)

    Jane

    2011-03-07

    Mar 7, 2011 ... The effect of pH and temperature on the enzyme activity and stability of crude enzyme produced by T. lanuginosus THKU 56 were investigated. To study the effect of pH on activity, the reaction mixture of 0.5 ml of enzyme and 0.5 ml of 1% insoluble oat spelt xylan in 50 mM buffers with various pH values ...

  7. Production of xylan-degrading enzymes by a Trichoderma harzianum strain

    Directory of Open Access Journals (Sweden)

    Cacais André O.Guerreiro

    2001-01-01

    Full Text Available Trichoderma harzianum strain 4 produced extracellular xylan-degrading enzymes, namely beta-xylanase, beta-xylosidase and alpha-arabinofuranosidase, when grown in liquid medium cultures containing oat spelt xylan as inducer. Cellulase activity was not detected. The pattern of xylan-degrading enzymes induction was influenced by the form of xylan present in the medium. They were detected in different incubation periods. Electrophoretic separation of the proteins from liquid culture filtrates by SDS-PAGE showed a variety of bands with high and low molecular weights.

  8. Do saproxylic beetles respond numerically to rapid changes in dead wood availability following moth outbreaks?

    OpenAIRE

    Schultze, Sabrina

    2012-01-01

    Outbreaks of defoliating insects periodically cause mass mortality of trees, thereby generating pulses of dead wood resources for saproxylic (i.e. dead-wood dependent) organisms. This study investigated the responses of saproxylic beetles to a dead wood resource pulse caused by recent (2001-2009) outbreaks of geometrid moths in the subarctic mountain birch forest of the Varanger region in northern Norway. A large scale (20 km) transect design, implementing window (flight interception) traps a...

  9. Birch pollen allergy: molecular characterization and hypoallergenic products

    NARCIS (Netherlands)

    Schenk, M.F.

    2008-01-01

    Allergic diseases, such as hay fever and food allergy, affect a substantial part of the population in westernized countries. Pollen of the European white birch (Betula pendula) is a considerable cause of hay fever (seasonal allergic rhinitis) in northern and central Europe. The major birch pollen

  10. Expression of bgt gene in transgenic birch (Betula platyphylla Suk ...

    African Journals Online (AJOL)

    Study on the characteristics of integration and expression is the basis of genetic stability of foreign genes in transgenic trees. To obtain insight into the relationship of transgene copy number and expression level, we screened 22 transgenic birch lines. Southern blot analysis of the transgenic birch plants indicated that the ...

  11. Expression of bgt gene in transgenic birch (Betula platyphylla Suk.)

    African Journals Online (AJOL)

    STORAGESEVER

    2009-08-04

    Aug 4, 2009 ... Study on the characteristics of integration and expression is the basis of genetic stability of foreign genes in transgenic trees. To obtain insight into the relationship of transgene copy number and expression level, we screened 22 transgenic birch lines. Southern blot analysis of the transgenic birch.

  12. Oral allergy syndrome to chicory associated with birch pollen allergy

    NARCIS (Netherlands)

    Cadot, P.; Kochuyt, A.-M.; van Ree, R.; Ceuppens, J. L.

    2003-01-01

    BACKGROUND: A few cases of IgE-mediated chicory allergy with oral, cutaneous, and/or respiratory symptoms are reported. We present 4 patients with inhalant birch pollen allergy and oral allergy syndrome to chicory. IgE-binding proteins in chicory and cross-reactivity with birch pollen were studied.

  13. PROTECTIVE TREATMENT OF WOOD IMPREGNATING COMPOSITION OF PETROCHEMICAL WASTE

    Directory of Open Access Journals (Sweden)

    T. V. Maslakova

    2015-01-01

    Full Text Available The paper presents results of experimental and theoretical studies aimed at expanding the applications of the copolymers on the basis of the waste styrene production. One of the areas is used as impregnating compositions of wood materials, selection of optimal conditions modification on samples of the most widely used in the industry of wood, such as birch, aspen and other. Studies were conducted to obtain and use an impregnating compositions based on copolymers synthesized from waste products of styrene and the cubic remainder rectification of ethylbenzene (CRRE for the protective treatment of birch wood. Identified physic-chemical characteristics of physical mixtures of copolymers «CORS», «STAM», CRRE at different ratios. Studied the process of modification birch using the method of experiment planning greco-latin square of the fourth order, and the influence of such factors as the temperature of the impregnating composition, the duration of the impregnation, the temperature and duration of thermal treatment on the performance moisture resistance of wood. Were established optimal conditions modification birch wood treated impregnating compositions on the basis of physical mixtures of copolymer «CORS» with CRRE and copolymer «STAM» with CRRE is the mixing ratio 2:1, the duration and temperature of the impregnation 7 h and 95 0C, time and temperature of heat treatment 7 h and 170 0C, respectively. A sealing composition containing CRRE with copolymer «STAM» 1:2 is more preferable, as in the structure of the copolymer «STAM» contains carboxyl and anhydrite group. Thus was justified use for the modification of natural wood impregnating compositions on the basis of physical mixtures of CRRE with copolymers «CORS» and «STAM», which improve the properties of wood, increase moisture and weather resistance more than twice.

  14. BIRCH: A user-oriented, locally-customizable, bioinformatics system

    Science.gov (United States)

    Fristensky, Brian

    2007-01-01

    Background Molecular biologists need sophisticated analytical tools which often demand extensive computational resources. While finding, installing, and using these tools can be challenging, pipelining data from one program to the next is particularly awkward, especially when using web-based programs. At the same time, system administrators tasked with maintaining these tools do not always appreciate the needs of research biologists. Results BIRCH (Biological Research Computing Hierarchy) is an organizational framework for delivering bioinformatics resources to a user group, scaling from a single lab to a large institution. The BIRCH core distribution includes many popular bioinformatics programs, unified within the GDE (Genetic Data Environment) graphic interface. Of equal importance, BIRCH provides the system administrator with tools that simplify the job of managing a multiuser bioinformatics system across different platforms and operating systems. These include tools for integrating locally-installed programs and databases into BIRCH, and for customizing the local BIRCH system to meet the needs of the user base. BIRCH can also act as a front end to provide a unified view of already-existing collections of bioinformatics software. Documentation for the BIRCH and locally-added programs is merged in a hierarchical set of web pages. In addition to manual pages for individual programs, BIRCH tutorials employ step by step examples, with screen shots and sample files, to illustrate both the important theoretical and practical considerations behind complex analytical tasks. Conclusion BIRCH provides a versatile organizational framework for managing software and databases, and making these accessible to a user base. Because of its network-centric design, BIRCH makes it possible for any user to do any task from anywhere. PMID:17291351

  15. BIRCH: A user-oriented, locally-customizable, bioinformatics system

    Directory of Open Access Journals (Sweden)

    Fristensky Brian

    2007-02-01

    Full Text Available Abstract Background Molecular biologists need sophisticated analytical tools which often demand extensive computational resources. While finding, installing, and using these tools can be challenging, pipelining data from one program to the next is particularly awkward, especially when using web-based programs. At the same time, system administrators tasked with maintaining these tools do not always appreciate the needs of research biologists. Results BIRCH (Biological Research Computing Hierarchy is an organizational framework for delivering bioinformatics resources to a user group, scaling from a single lab to a large institution. The BIRCH core distribution includes many popular bioinformatics programs, unified within the GDE (Genetic Data Environment graphic interface. Of equal importance, BIRCH provides the system administrator with tools that simplify the job of managing a multiuser bioinformatics system across different platforms and operating systems. These include tools for integrating locally-installed programs and databases into BIRCH, and for customizing the local BIRCH system to meet the needs of the user base. BIRCH can also act as a front end to provide a unified view of already-existing collections of bioinformatics software. Documentation for the BIRCH and locally-added programs is merged in a hierarchical set of web pages. In addition to manual pages for individual programs, BIRCH tutorials employ step by step examples, with screen shots and sample files, to illustrate both the important theoretical and practical considerations behind complex analytical tasks. Conclusion BIRCH provides a versatile organizational framework for managing software and databases, and making these accessible to a user base. Because of its network-centric design, BIRCH makes it possible for any user to do any task from anywhere.

  16. Establishing an Alaskan birch syrup industry: Birch Syrup—It’s the Un-maple!TM

    Science.gov (United States)

    Marlene. Cameron

    2001-01-01

    Ten years ago a small group of Alaskans began commercial production of birch syrup from the sap of the paper birch, Betula papyrifera, and established an industry that is expanding in response to demand and has the potential to make a significant contribution to Alaska's economy. There are still many problems to be solved; research and...

  17. Wood burning

    Energy Technology Data Exchange (ETDEWEB)

    Winkelmann, H

    1955-01-01

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

  18. Engineering the Xylan Utilization System in Bacillus subtilis for Production of Acidic Xylooligosaccharides

    Science.gov (United States)

    Mun Su Rhee; Lusha Wei; Neha Sawhney; John D. Rice; Franz J. St. John; Jason C. Hurlbert; James F. Preston

    2014-01-01

    Xylans are the predominant polysaccharides in hemicelluloses and an important potential source of biofuels and chemicals. The ability of Bacillus subtilis subsp. subtilis strain 168 to utilize xylans has been ascribed to secreted glycoside hydrolase family 11 (GH11) and GH30 endoxylanases, encoded by the xynA and...

  19. Diversity in Production of Xylan-Degrading Enzymes Among Species Belonging to the Trichoderma Section Longibrachiatum

    NARCIS (Netherlands)

    Toth, K.; Gool, van M.P.; Schols, H.A.; Samuels, G.J.; Gruppen, H.; Szakacs, G.

    2013-01-01

    Xylan is an important part of plant biomass and represents a renewable raw material for biorefineries. Contrary to cellulose, the structure of hemicellulose is quite complex. Therefore, the biodegradation of xylan needs the cooperation of many enzymes. For industrial production of xylanase

  20. Gorse (Ulex europaeus) as a possible source of xylans by hydrothermal treatment

    NARCIS (Netherlands)

    Ligero, P.; Vega, de A.; Kolk, van der J.C.; Dam, van J.E.G.

    2011-01-01

    Autocatalytic hydrothermal process conditions were used to study Ulex europæus (Gorse) as a source of xylan compounds. The aim was to study the possibilities for using this unutilised biomass material to produce xylans. Ulex is an evergreen shrub that grows in the northwest of Spain and has no

  1. High oxygen nanocomposite barrier films based on xylan and nanocrystalline cellulose

    Science.gov (United States)

    Amit Saxena; Thomas J. Elder; Jeffrey Kenvin; Arthur J. Ragauskas

    2010-01-01

    The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan, sorbitol and nanocrystalline cellulose. The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more...

  2. Thermoactive cellulase-free xylanase production from alkaliphilic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... The enzymatic hydrolysis of xylan, a major hemicellulose ... agar (glucose replaced by 1.0% w/v Birch-Wood Xylan (BW-X, ..... Thermal stability was determined by preincubating the xylanase at pH 9.0; at 60.0°C for 1 h.

  3. Synthesis and thermal characterization of xylan-graft-polyacrylonitrile.

    Science.gov (United States)

    Ünlü, Cüneyt H; Öztekin, N Simge; Atıcı, Oya Galioğlu

    2012-10-01

    In this study emulsion polymerization of acrylonitrile using xylan from agricultural waste material (corn cob) and cerium ammonium nitrate was investigated in terms of catalyst acid. Stock ceric solutions were prepared using either nitric or perchloric acid as catalyst. Optimum conditions were determined using different parameters such as reaction time, temperature, and component concentrations. Nitric acid catalyzed reactions resulted in maximum conversion ratio (96%) at 50°C, 1 h where ceric ion, acrylonitrile, xylan, and catalyst concentrations were 21.7 mmol l(-1), 0.5 mol l(-1), 0.2% (w/v), and 0.1 mol l(-1), respectively. However, 83% conversion was obtained with perchloric acid catalysis at 27 °C, 1 h where concentrations were 5.4 mmol l(-1), 0.8 mol l(-1), 0.5% (w/v), and 0.2 mol l(-1), respectively. Copolymer synthesis using perchloric acid was realized at milder conditions than using nitric acid. Thermal analyses of obtained polymers were conducted to characterize copolymers. Results showed that calculated activation energy, maximum degradation temperature, and heat of thermal decomposition changed relying mainly on molecular weight. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches.

    Science.gov (United States)

    Manninen, S; Huttunen, S; Vanhatalo, M; Pakonen, T; Hämäläinen, A

    2009-05-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O(3)) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O(3), i.e. O(3) levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O(3) and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.

  5. Physical Characterisation and Quantification of Total Above Ground Biomass Derived from First Thinnings for Wood Fuel Consumption in Ireland

    OpenAIRE

    Mockler, Nicholas

    2013-01-01

    Comprehensive knowledge of wood fuel properties assists in the optimisation of operations concerned with the harvesting, seasoning, processing and conversion of wood to energy. This study investigated the physical properties of wood fuel. These properties included moisture content and basic density. The field work also allowed for the quantification of above ground biomass partitions. The species investigated were alder (Alnus glutinosa), ash (Fraxinus excelsior L.), birch (Betula spp.), lodg...

  6. Variation of Drying Strains between Tangential and Radial Directions in Asian White Birch

    Directory of Open Access Journals (Sweden)

    Zongying Fu

    2016-03-01

    Full Text Available In this study, wood disks of 30 mm in thickness cut from white birch (Betula platyphylla Suk logs were dried at a constant temperature (40 °C. The drying strains including practical shrinkage strain, elastic strain, viscoelastic creep strain and mechano-sorptive creep were measured both tangentially and radially. The effects of moisture content and radial position on each strain were also discussed qualitatively. Overall, the difference of the practical shrinkage strain between the tangential and radial directions was proportional to the distance from the pith. The tangential elastic strain and viscoelastic creep strain were higher than these strains in a radial direction, and they all decreased with the decrease of moisture content. Additionally, there were opposite mechano-sorptive creep between tangential and radial directions.

  7. Wood Dust

    Science.gov (United States)

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

  8. Wood Smoke

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2004-01-01

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

  10. Study on the Hydrolysis Kinetics of Xylan on Different Acid Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Na, Byeong-Il; Lee, Jae-Won [Chonnam National University, Gwangju (Korea, Republic of)

    2014-04-15

    In this study, we investigated kinetic model for the acid-catalyzed xylan hydrolysis at temperature 120-150 .deg. C. Also, we analyzed the kinetic parameters for xylose production and furfural decomposition. The hydrolysis of xylan and the degradation of xylose were promoted by high reaction temperature and acid concentration. The optimal hydrolysis condition for the highest reaction rate constants (k{sub 1}) was different depending on the acid catalysts. Among sulfuric, oxalic and maleic acid, the xylan reaction rate constants (k{sub 1}) to xylose had the highest value of 0.0241 min{sup -1} when 100 mM sulfuric acid was used at 120 .deg. C. However, sulfuric acid induced more xylose degradation compared to oxalic and maleic acid hydrolysis. The activation energy for xylan degradation was the highest when sulfuric acid was used.

  11. Food allergy to apple and specific immunotherapy with birch pollen

    DEFF Research Database (Denmark)

    Hansen, K.S.; Khinchi, M.S.; Skov, P.S.

    2004-01-01

    Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen-allergic......Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen......-allergic patients were included in a double-blind, double-dummy, and placebo-controlled comparison of sublingual-swallow (SLIT) and subcutaneous (SCIT) administration of a birch pollen extract. Sixty-nine percent of these patients reported allergy to apple. The clinical reactivity to apple was evaluated by open...... oral challenges with fresh apple and a questionnaire. The immunoglobulin E (IgE)-reactivity was assessed by skin prick test (SPT), specific IgE, and leukocyte histamine release (HR). Forty patients were included in the final evaluation of the effect of SIT. The challenges were positive in 9 (SCIT), 6...

  12. Budburst phenology of white birch in industrially polluted areas

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.; Eraenen, Janne K.; Zverev, Vitali E.

    2007-01-01

    Effects of environmental contamination on plant seasonal development have only rarely been properly documented. Monitoring of leaf growth in mountain birch, Betula pubescens subsp. czerepanovii, around a nickel-copper smelter at Monchegorsk hinted advanced budburst phenology in most polluted sites. However, under laboratory conditions budburst of birch twigs cut in late winter from trees naturally growing around three point polluters (nickel-copper smelter at Monchegorsk, aluminium factory at Kandalaksha, and iron pellet plant at Kostomuksha) showed no relationship with distance from the emission source. In a greenhouse experiment, budburst phenology of mountain birch seedlings grown in unpolluted soil did not depend on seedling origin (from heavily polluted vs. clean sites), whereas seedlings in metal-contaminated soil demonstrated delayed budburst. These results allow to attribute advanced budburst phenology of white birch in severely polluted sites to modified microclimate, rather than to pollution impact on plant physiology or genetics. - Advanced budburst phenology in white birch in severely polluted sites is explained by modified microclimate, not by pollution impact on plant physiology

  13. Possibilities for the Use of Wood Ashes in Agriculture

    OpenAIRE

    Barbara Symanowicz; Marcin Becher; Dawid Jaremko; Korneliusz Skwarek

    2018-01-01

    The aim of the study was to determine the agricultural usefulness of the ashes obtained following the combustion of wood of fourteen tree species (pear tree, apple tree, aspen, ash, alder, birch, poplar, hornbeam, pine, common walnut, oak, hazel, bird cherry and spruce) in home fireplaces. The following physical properties of the ashes were determined: colour, solubility, porosity, absorbability, compression strength, degree of fineness, moisture content and spreadability. In the ashes...

  14. 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 (...

  15. Synthesis of cell wall xylans and glucans by golgi membranes

    International Nuclear Information System (INIS)

    Gibeaut, D.M.; Carpita, N.C.

    1989-01-01

    We investigated the biosynthesis of mixed-linkage β-D-glucan and glucuronoarabinoxylans which make up the hemicellulosic matrix of the primary cell walls of maize and other cereal grasses. The Golgi apparatus was enriched from plasma membrane and other organelles by flotation density gradient centrifugation. Glucan synthase I and II, which are established markers for Golgi and plasma membrane, respectively, displayed considerable overlap in conventional separations with sucrose density gradients. Flotation gradients improved separation of the membranes substantially, but the different synthases themselves also incorporated radioactivity from either 10 μM or 1 mM UDP-[ 14 C]-glucose into polymer. Relative incorporation of radioactivity into polymers from UDP-[ 14 C]-xylose by the various membrane fractions was nearly identical to relative IDPase activities, indicating that combined xylosyl transferase-xylan synthase represents a new, unequivocal marker for the Golgi apparatus. We also have developed techniques of gas-liquid chromatography and radiogas proportional counting to achieve capillary quality separation of partially methylated alditol acetates with simultaneous determination of radioactivity in the derivatives. Digestion of polymeric products by specific endo-glycanohydrolases to diagnostic oligosaccharides also reveal specific kinds of polysaccharides synthesized by the Golgi membranes. A combination of these techniques provides unequivocal determination of the linkage structure of specific polymers synthesized by the purified Golgi apparatus

  16. Modification of Bacterial Cellulose Biofilms with Xylan Polyelectrolytes.

    Science.gov (United States)

    Santos, Sara M; Carbajo, José M; Gómez, Nuria; Ladero, Miguel; Villar, Juan C

    2017-11-28

    The effect of the addition of two [4-butyltrimethylammonium]-xylan chloride polyelectrolytes (BTMAXs) on bacterial cellulose (BC) was evaluated. The first strategy was to add the polyelectrolytes to the culture medium together with a cell suspension of the bacterium. After one week of cultivation, the films were collected and purified. The second approach consisted of obtaining a purified and homogenized BC, to which the polyelectrolytes were added subsequently. The films were characterized in terms of tear and burst indexes, optical properties, surface free energy, static contact angle, Gurley porosity, SEM, X-ray diffraction and AFM. Although there are small differences in mechanical and optical properties between the nanocomposites and control films, the films obtained by BC synthesis in the presence of BTMAXs were remarkably less opaque, rougher, and had a much lower specular gloss. The surface free energy depends on the BTMAXs addition method. The crystallinity of the composites is lower than that of the control material, with a higher reduction of this parameter in the composites obtained by adding the BTMAXs to the culture medium. In view of these results, it can be concluded that BC-BTMAX composites are a promising new material, for example, for paper restoration.

  17. Modification of Bacterial Cellulose Biofilms with Xylan Polyelectrolytes

    Directory of Open Access Journals (Sweden)

    Sara M. Santos

    2017-11-01

    Full Text Available The effect of the addition of two [4-butyltrimethylammonium]-xylan chloride polyelectrolytes (BTMAXs on bacterial cellulose (BC was evaluated. The first strategy was to add the polyelectrolytes to the culture medium together with a cell suspension of the bacterium. After one week of cultivation, the films were collected and purified. The second approach consisted of obtaining a purified and homogenized BC, to which the polyelectrolytes were added subsequently. The films were characterized in terms of tear and burst indexes, optical properties, surface free energy, static contact angle, Gurley porosity, SEM, X-ray diffraction and AFM. Although there are small differences in mechanical and optical properties between the nanocomposites and control films, the films obtained by BC synthesis in the presence of BTMAXs were remarkably less opaque, rougher, and had a much lower specular gloss. The surface free energy depends on the BTMAXs addition method. The crystallinity of the composites is lower than that of the control material, with a higher reduction of this parameter in the composites obtained by adding the BTMAXs to the culture medium. In view of these results, it can be concluded that BC–BTMAX composites are a promising new material, for example, for paper restoration.

  18. Root-Crown Relations of Young Sugar Maple and Yellow Birch

    Science.gov (United States)

    Carl H. Tubbs

    1977-01-01

    Young forest-grown sugar maple and yellow birch (1 to 6 inches d.b.h.) crowns were mapped and roots excavated. Crown dimensions were compared. Sugar maple roots usually terminated within a few feet of the crown perimeter. Yellow birch roots frequently terminated well outside crown perimeters and roots of birch were more irregularly distributed than those of maple....

  19. Genetic and environmental variation in rust frequency on mature mountain birch trees

    Energy Technology Data Exchange (ETDEWEB)

    Elamo, Pirjo; Saloniemi, Irma; Helander, M.L.; Neuvonen, Seppo [Turku Univ. (Finland). Dept. of Biology) and (Kevo Subarctic Research Inst., Turku (Finland)

    2000-07-01

    This study investigated genetic and environmental variation in the frequency of birch rust, the most important leaf disease of birch species, The same half-sib families of mature mountain birch trees were studied in two areas corresponding to their natural growing habitats over 3 yrs. The frequency of birch rust was examined both in the field and from detached leaves inoculated in the laboratory. The frequency of birch rust varied among the mountain birch families. However, the heritability of birch rust resistance was found to be fairly low, with the heritability of naturally occurring birch rust varying between 0.27 and 0.41. The frequency of birch rust varied highly between the two study areas and among study years. Nevertheless, the relative frequency of birch rust among tree individuals and tree families remained similar and as a result no notable genotype x environment interaction was observed. The field and in vitro results differed with respect to the ranking of birch families by birch rust resistance.

  20. A prospective study comparing the efficacy and safety of two sublingual birch allergen preparations

    NARCIS (Netherlands)

    Klimek, Ludger; Sperl, Annette; van Twuijver, Esther; van Ree, Ronald; Kleinjans, Huub; Boot, Johan Diderik; Pfaar, Oliver

    2014-01-01

    Background: SUBLIVAC FIX Birch (SUB-B) is a liquid oral preparation of Betula verrucosa pollen extract for the treatment of allergic rhinitis/rhinoconjuctivitis induced by birch pollen. The major allergen content of SUB-B and Staloral Birch (Stal-B) have been shown to be comparable. In order to

  1. Consumer preferences and willingness to pay for character-marked cabinets from Alaska birch.

    Science.gov (United States)

    Geof Donovan; David. Nicholls

    2003-01-01

    Alaska birch lumber has a higher occurrence of defects (knots, bark pockets, flecks, spalting, etc.) when compared to competing hardwoods. These defects are a disadvantage when birch lumber is graded under standard National Hardwood Lumber Association (NHLA) grading rules. This paper examines whether defects and other character markings found in birch lumber may be an...

  2. 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...

  3. Sugar maple and yellow birch seedling growth after simulated browsing.

    Science.gov (United States)

    Frederick T. Metzger

    1977-01-01

    Simulating natural damage to leaders of forest-grown seedlings of yellow birch and sugar maple resulted in no loss of vigor but a loss in net height growth. Leader elongation depended upon seedling, shoot, and bud characteristics rather than on the extent of damage.

  4. Paper birch (Wiigwaas) of the Lake States, 1980-2010

    Science.gov (United States)

    W. Keith Moser; Mark H. Hansen; Dale Gormanson; Jonathan Gilbert; Alexandra Wrobel; Marla R. Emery; Michael J. Dockry

    2015-01-01

    Data on paper birch (Betula papyrifera L.; wiigwaas in the Ojibwe language), collected by the Forest Inventory and Analysis (FIA) program of the U.S. Forest Service on forested lands in the Great Lakes region (Michigan, Minnesota, and Wisconsin) from 1980 through 2010, are reported. Also presented are results and analysis of a supplemental inventory...

  5. Large-Scale Variations in Lumber Value Recovery of Yellow Birch and Sugar Maple in Quebec, Canada.

    Directory of Open Access Journals (Sweden)

    Mariana Hassegawa

    Full Text Available Silvicultural restoration measures have been implemented in the northern hardwoods forests of southern Quebec, Canada, but their financial applicability is often hampered by the depleted state of the resource. To help identify sites most suited for the production of high quality timber, where the potential return on silvicultural investments should be the highest, this study assessed the impact of stand and site characteristics on timber quality in sugar maple (Acer saccharum Marsh. and yellow birch (Betula alleghaniensis Britt.. For this purpose, lumber value recovery (LVR, an estimate of the summed value of boards contained in a unit volume of round wood, was used as an indicator of timber quality. Predictions of LVR were made for yellow birch and sugar maple trees contained in a network of more than 22000 temporary sample plots across the Province. Next, stand-level variables were selected and models to predict LVR were built using the boosted regression trees method. Finally, the occurrence of spatial clusters was verified by a hotspot analysis. Results showed that in both species LVR was positively correlated with the stand age and structural diversity index, and negatively correlated with the number of merchantable stems. Yellow birch had higher LVR in areas with shallower soils, whereas sugar maple had higher LVR in regions with deeper soils. The hotspot analysis indicated that clusters of high and low LVR exist across the province for both species. Although it remains uncertain to what extent the variability of LVR may result from variations in past management practices or in inherent site quality, we argue that efforts to produce high quality timber should be prioritized in sites where LVR is predicted to be the highest.

  6. Large-Scale Variations in Lumber Value Recovery of Yellow Birch and Sugar Maple in Quebec, Canada.

    Science.gov (United States)

    Hassegawa, Mariana; Havreljuk, Filip; Ouimet, Rock; Auty, David; Pothier, David; Achim, Alexis

    2015-01-01

    Silvicultural restoration measures have been implemented in the northern hardwoods forests of southern Quebec, Canada, but their financial applicability is often hampered by the depleted state of the resource. To help identify sites most suited for the production of high quality timber, where the potential return on silvicultural investments should be the highest, this study assessed the impact of stand and site characteristics on timber quality in sugar maple (Acer saccharum Marsh.) and yellow birch (Betula alleghaniensis Britt.). For this purpose, lumber value recovery (LVR), an estimate of the summed value of boards contained in a unit volume of round wood, was used as an indicator of timber quality. Predictions of LVR were made for yellow birch and sugar maple trees contained in a network of more than 22000 temporary sample plots across the Province. Next, stand-level variables were selected and models to predict LVR were built using the boosted regression trees method. Finally, the occurrence of spatial clusters was verified by a hotspot analysis. Results showed that in both species LVR was positively correlated with the stand age and structural diversity index, and negatively correlated with the number of merchantable stems. Yellow birch had higher LVR in areas with shallower soils, whereas sugar maple had higher LVR in regions with deeper soils. The hotspot analysis indicated that clusters of high and low LVR exist across the province for both species. Although it remains uncertain to what extent the variability of LVR may result from variations in past management practices or in inherent site quality, we argue that efforts to produce high quality timber should be prioritized in sites where LVR is predicted to be the highest.

  7. The Four Arabidopsis Reduced Wall Acetylation Genes are Expressed in Secondary Wall-Containing Cells and Required for the Acetylation of Xylan

    Science.gov (United States)

    Xylan is one of the major polysaccharides in cellulosic biomass, and understanding the mechanisms underlying xylan biosynthesis will potentially help us design strategies to produce cellulosic biomass better suited for biofuel production. Although a number of genes have been show...

  8. Impact of the fouling mechanism on enzymatic depolymerization of xylan in different configurations of membrane reactors

    DEFF Research Database (Denmark)

    Mohd Sueb, Mohd Shafiq Bin; Luo, Jianquan; Meyer, Anne S.

    2017-01-01

    In order to maximize enzymatic xylan depolymerization while simultaneously purifying the resulting monosaccharide (xylose), different ultrafiltration (UF) membrane reactor configurations were evaluated. Initial results showed that the two hydrolytic enzymes required for complete depolymerization...... which hindered enzymatic attack in addition to fouling. Reaction with both enzymes followed by UF was found to be the optimal configuration, providing at least 40% higher xylan hydrolysis than the cascade configuration (involving sequential reaction with each of the enzymes separately......) and the simultaneous reaction-filtration with both enzymes, respectively. This study thus confirmed that the reactor configuration has a crucial impact on the performance of both the reaction and the separation process of xylose during enzymatic xylan degradation, and that the type of fouling mechanism varies...

  9. Designer biomass for next-generation biorefineries: leveraging recent insights into xylan structure and biosynthesis.

    Science.gov (United States)

    Smith, Peter J; Wang, Hsin-Tzu; York, William S; Peña, Maria J; Urbanowicz, Breeanna R

    2017-01-01

    Xylans are the most abundant noncellulosic polysaccharides in lignified secondary cell walls of woody dicots and in both primary and secondary cell walls of grasses. These polysaccharides, which comprise 20-35% of terrestrial biomass, present major challenges for the efficient microbial bioconversion of lignocellulosic feedstocks to fuels and other value-added products. Xylans play a significant role in the recalcitrance of biomass to degradation, and their bioconversion requires metabolic pathways that are distinct from those used to metabolize cellulose. In this review, we discuss the key differences in the structural features of xylans across diverse plant species, how these features affect their interactions with cellulose and lignin, and recent developments in understanding their biosynthesis. In particular, we focus on how the combined structural and biosynthetic knowledge can be used as a basis for biomass engineering aimed at developing crops that are better suited as feedstocks for the bioconversion industry.

  10. Efficient extraction of xylan from delignified corn stover using dimethyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, John; Decker, Stephen R.; Michener, William; Black, Stuart

    2013-09-13

    Xylan can be extracted from biomass using either alkali (KOH or NaOH) or dimethyl sulfoxide (DMSO); however, DMSO extraction is the only method that produces a water-soluble xylan. In this study, DMSO extraction of corn stover was studied at different temperatures with the objective of finding a faster, more efficient extraction method. The temperature and time of extraction were compared followed by a basic structural analysis to ensure that no significant structural changes occurred under different temperatures. The resulting data showed that heating to 70 degrees C during extraction can give a yield comparable to room temperature extraction while reducing the extraction time by ~90 %. This method of heating was shown to be the most efficient method currently available and was shown to retain the important structural characteristics of xylan extracted with DMSO at room temperature.

  11. Wood preservation

    Science.gov (United States)

    Kevin Archer; Stan Lebow

    2006-01-01

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

  12. In Vitro Antioxidant, Anticoagulant and Antimicrobial Activity and in Inhibition of Cancer Cell Proliferation by Xylan Extracted from Corn Cobs

    Science.gov (United States)

    Melo-Silveira, Raniere Fagundes; Fidelis, Gabriel Pereira; Costa, Mariana Santana Santos Pereira; Telles, Cinthia Beatrice Silva; Dantas-Santos, Nednaldo; de Oliveira Elias, Susana; Ribeiro, Vanessa Bley; Barth, Afonso Luis; Macedo, Alexandre José; Leite, Edda Lisboa; Rocha, Hugo Alexandre Oliveira

    2012-01-01

    Xylan is one of most abundant polymer after cellulose. However, its potential has yet to be completely recognized. Corn cobs contain a considerable reservoir of xylan. The aim of this work was to study some of the biological activities of xylan obtained from corn cobs after alkaline extraction enhanced by ultrasonication. Physical chemistry and infrared analyses showed 130 kDa heteroxylan containing mainly xylose:arabinose: galactose:glucose (5.0:1.5:2.0:1.2). Xylan obtained exhibited total antioxidant activity corresponding to 48.5 mg of ascorbic acid equivalent/g of xylan. Furthermore, xylan displayed high ferric chelating activity (70%) at 2 mg/mL. Xylan also showed anticoagulant activity in aPTT test. In antimicrobial assay, the polysaccharide significantly inhibited bacterial growth of Klebsiella pneumoniae. In a test with normal and tumor human cells, after 72 h, only HeLa tumor cell proliferation was inhibited (p < 0.05) in a dose-dependent manner by xylan, reaching saturation at around 2 mg/mL, whereas 3T3 normal cell proliferation was not affected. The results suggest that it has potential clinical applications as antioxidant, anticoagulant, antimicrobial and antiproliferative compounds. PMID:22312261

  13. Imidazole, a New Tunable Reagent for Producing Nanocellulose, Part I: Xylan-Coated CNCs and CNFs

    Directory of Open Access Journals (Sweden)

    Jia Mao

    2017-09-01

    Full Text Available Imidazole is reported to be an effective reactant for the production of nanocellulose from hardwood pulp. The morphologies and surface properties of the nanocellulose can be simply tailored according to the water content in the imidazole system: with pure imidazole, cellulose nanofibrils (CNFs in a yield of 10 wt % can be produced. With 25 wt % of water in imidazole, cellulose nanocrystals (CNCs are obtained in 20 wt % yield. Both nanocelluloses exhibit crystallinity indices in the order of 70%. Interestingly, they retain the original xylan from the pulp with ca. 9–10 wt % of residual xylan content.

  14. On the Effect of Thinning on Tree Growth and Stand Structure of White Birch (Betula platyphylla Sukaczev and Siberian Larch (Larix sibirica Ledeb. in Mongolia

    Directory of Open Access Journals (Sweden)

    Alexander Gradel

    2017-03-01

    Full Text Available The forests of North Mongolia are largely dominated either by larch (Larix sibirica Ledeb. or birch (Betula platyphylla Sukaczev. The increasing demand for timber and firewood is currently met by removal of wood from these forest stands. Therefore, silvicultural approaches that account for both utilization and protection are needed. Thinning trials were established in the research area Altansumber, in the mountain forest steppe west of the town of Darkhan. We analyzed the response of non-spatial and spatial structure and growth of birch and larch stands on thinning. Before thinning, spatial tree distribution was largely clumped. Thinning promoted regular tree distribution. Ingrowth of new stems after thinning tended to redirect stand structure towards clumping. Both relative and absolute tree growth and competition were evaluated before, directly after, and three years after the thinning. Competition played a significant role in tree growth before thinning. A reduction in competition after thinning triggered significantly increased growth of both birch and larch. The observed positive growth response was valid in absolute and relative terms. A methodically based forest management strategy, including thinning operations and selective cuttings, could be established, even under the harsh Mongolian conditions. Our findings could initiate the development of broader forest management guidelines for the light-taiga dominated stands.

  15. Wood handbook : wood as an engineering material

    Science.gov (United States)

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

    2010-01-01

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

  16. Changes in structural and chemical components of wood delignified by fungi

    Energy Technology Data Exchange (ETDEWEB)

    Blanchette, R.A.; Otjen, L.; Effland, M.J.; Eslyn, W.E.

    1985-01-01

    Cerrena unicolor, Ganoderma applanatum, Ischnoderma resinosum and Poria medulla-panis were associated with birch (Betula papyrifera) wood that had been selectively delignified in the forest. Preferential lignin degradation was not uniformly distributed throughout the decayed wood. A typical white rot causing a simultaneous removal of all cell wall components was also present. In the delignified wood, 95 to 98% of the lignin was removed as well as substantial amounts of hemicelluloses. Scanning and transmission electron microscopy were used to identify the micromorphological and ultrastructural changes that occurred in the cells during degradation. In delignified areas the compound middle lamella was extensively degraded causing a defibration of cells. The secondary wall, especially the S2 layer, remained relatively unaltered. In simultaneously white-rotted wood all cell wall layers were progressively removed from the lumen toward the middle lamella causing erosion troughs or holes to form. Large voids filled with fungal mycelia resulted from a coalition of degraded areas. Birch wood decayed in laboratory soil-block tests was also intermittently delignified, selective delignification, sparsely distributed throughout the wood, and a simultaneous rot resulting in the removal of all cell wall components were evident. SEM appears to be an appropriate technique for examining selectively delignified decayed wood. 30 references.

  17. Particulate emissions from the combustion of birch, beech, and spruce logs cause different cytotoxic responses in A549 cells.

    Science.gov (United States)

    Kasurinen, Stefanie; Jalava, Pasi I; Happo, Mikko S; Sippula, Olli; Uski, Oskari; Koponen, Hanna; Orasche, Jürgen; Zimmermann, Ralf; Jokiniemi, Jorma; Hirvonen, Maija-Riitta

    2017-05-01

    According to the World Health Organization particulate emissions from the combustion of solid fuels caused more than 110,000 premature deaths worldwide in 2010. Log wood combustion is the most prevalent form of residential biomass heating in developed countries, but it is unknown how the type of wood logs used in furnaces influences the chemical composition of the particulate emissions and their toxicological potential. We burned logs of birch, beech and spruce, which are used commonly as firewood in Central and Northern Europe in a modern masonry heater, and compared them to the particulate emissions from an automated pellet boiler fired with softwood pellets. We determined the chemical composition (elements, ions, and carbonaceous compounds) of the particulate emissions with a diameter of less than 1 µm and tested their cytotoxicity, genotoxicity, inflammatory potential, and ability to induce oxidative stress in a human lung epithelial cell line. The chemical composition of the samples differed significantly, especially with regard to the carbonaceous and metal contents. Also the toxic effects in our tested endpoints varied considerably between each of the three log wood combustion samples, as well as between the log wood combustion samples and the pellet combustion sample. The difference in the toxicological potential of the samples in the various endpoints indicates the involvement of different pathways of toxicity depending on the chemical composition. All three emission samples from the log wood combustions were considerably more toxic in all endpoints than the emissions from the pellet combustion. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1487-1499, 2017. © 2016 Wiley Periodicals, Inc.

  18. Birch veneer and plywood demand: projected needs of the industry

    Science.gov (United States)

    Clark E. McDonald

    1969-01-01

    Production of hardwood plywood in the United States has increased steadily from 1955 to 1967 - almost doubling during this period (table 1). The peak year for shipments of hardwood plywood was 1965, for all species (1,668,313,000 square feet surface measure) and also for birch ( 600,72 3,000 square feet surface measure). The U.S. Bureau of Census figures are not...

  19. Reproduction of mountain birch along a strong pollution gradient near Monchegorsk, Northwestern Russia

    International Nuclear Information System (INIS)

    Kozlov, Mikhail V.; Zvereva, Elena L.

    2004-01-01

    We explored effects of severe pollution on sexual reproduction of mountain birch, Betula pubescens subsp. czerepanovii, by counting catkins on sample branches and weighing both somatic and generative structures of both short and long shoots from birches growing at 21 sites around large nickel-copper smelter at Monchegorsk, Northwestern Russia. Proportion of reproducing trees, production of catkins, shoot and catkin weight, as well as the relative difference in weight of somatic structures of generative and vegetative shoots, were generally independent of pollution load; in 2003 birches growing in industrial barrens produced more catkins than birches growing in unpolluted forests. Thus, we found no support for the hypothesis that reproductive allocation should decrease with decrease in environmental capacity. Absence of adverse effects might indicate that long-lasting pollution impact already eliminated the most sensitive individuals from the affected birch populations. - Capsule: Variation in reproductive characteristics of mountain birch near the nickel-copper smelter at Monchegorsk is independent of pollution load

  20. Arabidopsis GUX Proteins Are Glucuronyltransferases Responsible for the Addition of Glucuronic Acid Side Chains onto Xylan

    Science.gov (United States)

    Xylan, the second most abundant cell wall polysaccharide, is composed of a linear backbone of β-(1,4)-linked xylosyl residues that are often substituted with sugar side chains, such as glucuronic acid (GlcA) and methylglucuronic acid (MeGlcA). It has recently been shown that muta...

  1. Properties of polyvinyl alcohol/xylan composite films with citric acid.

    Science.gov (United States)

    Wang, Shuaiyang; Ren, Junli; Li, Weiying; Sun, Runcang; Liu, Shijie

    2014-03-15

    Composite films of xylan and polyvinyl alcohol were produced with citric acid as a new plasticizer or a cross-linking agent. The effects of citric acid content and polyvinyl alcohol/xylan weight ratio on the mechanical properties, thermal stability, solubility, degree of swelling and water vapor permeability of the composite films were investigated. The intermolecular interactions and morphology of composite films were characterized by FTIR spectroscopy and SEM. The results indicated that polyvinyl alcohol/xylan composite films had good compatibility. With an increase in citric acid content from 10% to 50%, the tensile strength reduced from 35.1 to 11.6 MPa. However, the elongation at break increased sharply from 15.1% to 249.5%. The values of water vapor permeability ranged from 2.35 to 2.95 × 10(-7)g/(mm(2)h). Interactions between xylan and polyvinyl alcohol in the presence of citric acid become stronger, which were caused by hydrogen bond and ester bond formation among the components during film forming. Copyright © 2013. Published by Elsevier Ltd.

  2. In situ enzyme aided adsorption of soluble xylan biopolymers onto cellulosic material.

    Science.gov (United States)

    Chimphango, Annie F A; Görgens, J F; van Zyl, W H

    2016-06-05

    The functional properties of cellulose fibers can be modified by adsorption of xylan biopolymers. The adsorption is improved when the degree of biopolymers substitution with arabinose and 4-O-methyl-glucuronic acid (MeGlcA) side groups, is reduced. α-l-Arabinofuranosidase (AbfB) and α-d-glucuronidase (AguA) enzymes were applied for side group removal, to increase adsorption of xylan from sugarcane (Saccharum officinarum L) bagasse (BH), bamboo (Bambusa balcooa) (BM), Pinus patula (PP) and Eucalyptus grandis (EH) onto cotton lint. The AguA treatment increased the adsorption of all xylans by up to 334%, whereas, the AbfB increased the adsorption of the BM and PP by 31% and 44%, respectively. A combination of AguA and AbfB treatment increased the adsorption, but to a lesser extent than achieved with AguA treatment. This indicated that the removal of the glucuronic acid side groups provided the most significant increase in xylan adsorption to cellulose, in particular through enzymatic treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Hydrolysis of Wheat Arabinoxylan by Two Acetyl Xylan Esterases from Chaetomium thermophilum

    DEFF Research Database (Denmark)

    Tong, Xiaoxue; Lange, Lene; Grell, Morten Nedergaard

    2015-01-01

    The thermophilic filamentous ascomycete Chaetomium thermophilum produces functionally diverse hemicellulases when grown on hemicellulose as carbon source. Acetyl xylan esterase (EC 3.1.1.72) is an important accessory enzyme in hemicellulose biodegradation. Although the genome of C. thermophilum has...

  4. Characterization of O-acetil-(4-O-methylglucurono)xylans from Eucalyptus urograndis

    International Nuclear Information System (INIS)

    Magaton, Andreia da Silva; Pilo-Veloso, Dorila; Colodette, Jorge Luiz

    2008-01-01

    The O-acetyl- 4-O-methyl-(glucurono)xylans were isolated from E. urograndis by extraction with dimethyl sulfoxide, analysed for monosaccharide composition and structurally characterized by NMR spectroscopy. These xylans contained one 4-O-methyl-glucuronic acid substituent and 5.5 acetyl groups for approximately 10 xylose residues. About 10% of 4-O-methyl-glucuronic acid (MeGlcA) units were branched at O-2. The O-acetyl-4-O-methyl-(glucurono)-xylans were composed of the following (1→4)-linked β-D-xylopyranosyl structural elements: unsubstituted (51 mol%), 2-O-acetylated (12 mol%), 3-O-acetylated (20 mol%), 2,3-di-Oacetylated (6 mol%) and [MeGlcA α-(1→2)] [3-O-acetylated] (11 mol%). The weight-average molar mass and polydispersity of this xylan were 34.9 kDa and 1.16, respectively, as measured by size-exclusion chromatography. (author)

  5. Xylan hydrolysis in Populus trichocarpa × P. deltoides and model substrates during hydrothermal pretreatment.

    Science.gov (United States)

    Trajano, Heather L; Pattathil, Sivakumar; Tomkins, Bruce A; Tschaplinski, Timothy J; Hahn, Michael G; Van Berkel, Gary J; Wyman, Charles E

    2015-03-01

    Previous studies defined easy and difficult to hydrolyze fractions of hemicellulose that may result from bonds among cellulose, hemicellulose, and lignin. To understand how such bonds affect hydrolysis, Populus trichocarpa × Populus deltoides, holocellulose isolated from P. trichocarpa × P. deltoides and birchwood xylan were subjected to hydrothermal flow-through pretreatment. Samples were characterized by glycome profiling, HPLC, and UPLC-MS. Glycome profiling revealed steady fragmentation and removal of glycans from solids during hydrolysis. The extent of polysaccharide fragmentation, hydrolysis rate, and total xylose yield were lowest for P. trichocarpa × P. deltoides and greatest for birchwood xylan. Comparison of results from P. trichocarpa × P. deltoides and holocellulose suggested that lignin-carbohydrate complexes reduce hydrolysis rates and limit release of large xylooligomers. Smaller differences between results with holocellulose and birchwood xylan suggest xylan-cellulose hydrogen bonds limited hydrolysis, but to a lesser extent. These findings imply cell wall structure strongly influences hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Insight into glycoside hydrolases for debranched xylan degradation from extremely thermophilic bacterium Caldicellulosiruptor lactoaceticus.

    Directory of Open Access Journals (Sweden)

    Xiaojing Jia

    Full Text Available Caldicellulosiruptor lactoaceticus 6A, an anaerobic and extremely thermophilic bacterium, uses natural xylan as carbon source. The encoded genes of C. lactoaceticus 6A for glycoside hydrolase (GH provide a platform for xylan degradation. The GH family 10 xylanase (Xyn10A and GH67 α-glucuronidase (Agu67A from C. lactoaceticus 6A were heterologously expressed, purified and characterized. Both Xyn10A and Agu67A are predicted as intracellular enzymes as no signal peptides identified. Xyn10A and Agu67A had molecular weight of 47.0 kDa and 80.0 kDa respectively as determined by SDS-PAGE, while both appeared as homodimer when analyzed by gel filtration. Xyn10A displayed the highest activity at 80 °C and pH 6.5, as 75 °C and pH 6.5 for Agu67A. Xyn10A had good stability at 75 °C, 80 °C, and pH 4.5-8.5, respectively, and was sensitive to various metal ions and reagents. Xyn10A possessed hydrolytic activity towards xylo-oligosaccharides (XOs and beechwood xylan. At optimum conditions, the specific activity of Xyn10A was 44.6 IU/mg with beechwood xylan as substrate, and liberated branched XOs, xylobiose, and xylose. Agu67A was active on branched XOs with methyl-glucuronic acids (MeGlcA sub-chains, and primarily generated XOs equivalents and MeGlcA. The specific activity of Agu67A was 1.3 IU/mg with aldobiouronic acid as substrate. The synergistic action of Xyn10A and Agu67A was observed with MeGlcA branched XOs and xylan as substrates, both backbone and branched chain of substrates were degraded, and liberated xylose, xylobiose, and MeGlcA. The synergism of Xyn10A and Agu67A provided not only a thermophilic method for natural xylan degradation, but also insight into the mechanisms for xylan utilization of C. lactoaceticus.

  7. Dose in a house built with contaminated wood

    International Nuclear Information System (INIS)

    Thomassin, A.

    2006-01-01

    This paper aims to assess the annual effective dose which could be received by a person living in a house built in France with wood from Belarus and contaminated by cesium 137 from Chernobylsk accident fallout. After the context be specified and the potential levels of radioactivity presented, an assessment of the annual effective dose is performed, based on an as realistic as possible scenario. After calculations it appears that the annual effective dose by external exposure potentially received by an inhabitant living in a house build with contaminated wood (pine or birch) at 1,000 Bq/kg is of the order of 1 mSv, due to external exposure to walls. This dose is not negligible, and could even be much more higher if wood from highly contaminated Belarusian areas is used for building houses. Projects of such wooden buildings should be studied with a particular attention to the characterization of the contamination. (N.C.)

  8. Dose in a house built with contaminated wood

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin, A. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Fontenay aux Roses (France)

    2006-07-01

    This paper aims to assess the annual effective dose which could be received by a person living in a house built in France with wood from Belarus and contaminated by cesium 137 from Chernobylsk accident fallout. After the context be specified and the potential levels of radioactivity presented, an assessment of the annual effective dose is performed, based on an as realistic as possible scenario. After calculations it appears that the annual effective dose by external exposure potentially received by an inhabitant living in a house build with contaminated wood (pine or birch) at 1,000 Bq/kg is of the order of 1 mSv, due to external exposure to walls. This dose is not negligible, and could even be much more higher if wood from highly contaminated Belarusian areas is used for building houses. Projects of such wooden buildings should be studied with a particular attention to the characterization of the contamination. (N.C.)

  9. A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

    Directory of Open Access Journals (Sweden)

    Weili Gong

    2018-03-01

    Full Text Available Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS to cultures of filamentous fungi.

  10. A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

    Science.gov (United States)

    Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

    2018-01-01

    Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi. PMID:29623069

  11. A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study.

    Science.gov (United States)

    Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

    2018-01-01

    Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger . This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger , we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi.

  12. Identification of an algal xylan synthase indicates that there is functional orthology between algal and plant cell wall biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Jacob Kruger [Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology; Michigan State Univ., East Lansing, MI (United States). DOE Great Lakes Bioenergy Research Center; Busse-Wicher, Marta [Univ. of Cambridge (United Kingdom). Dept. of Biochemistry; Poulsen, Christian Peter [Carlsberg Research Lab., Copenhagen (Denmark); Fangel, Jonatan Ulrik [Carlsberg Research Lab., Copenhagen (Denmark); Smith, Peter James [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC); Yang, Jeong-Yeh [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Peña, Maria-Jesus [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC); Dinesen, Malene Hessellund [Carlsberg Research Lab., Copenhagen (Denmark); Martens, Helle Juel [Univ. of Copenhagen (Denmark). Dept. of Plant and Environmental Sciences; Melkonian, Michael [Univ. zu Koln (Germany). Botanical Inst., Dept. of Biological Sciences; Wong, Gane Ka-Shu [BGI-Shenzhen, Shenzhen, Guangdong (China); Moremen, Kelley W. [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Wilkerson, Curtis Gene [Michigan State Univ., East Lansing, MI (United States). Dept. of Plant Biology; Michigan State Univ., East Lansing, MI (United States). DOE Great Lakes Bioenergy Research Center; Michigan State Univ., East Lansing, MI (United States). Dept. of Biochemistry and Molecular Biology; Scheller, Henrik Vibe [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Genomics and Systems Biology Division; Dupree, Paul [Univ. of Cambridge (United Kingdom). Dept. of Biochemistry; Ulvskov, Peter [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Urbanowicz, Breeanna Rae [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC); Harholt, Jesper [Carlsberg Research Lab., Copenhagen (Denmark)

    2018-02-20

    Insights into the evolution of plant cell walls have important implications for comprehending these diverse and abundant biological structures. In order to understand the evolving structure-function relationships of the plant cell wall, it is imperative to trace the origin of its different components. The present study is focused on plant 1,4-β-xylan, tracing its evolutionary origin by genome and transcriptome mining followed by phylogenetic analysis, utilizing a large selection of plants and algae. It substantiates the findings by heterologous expression and biochemical characterization of a charophyte alga xylan synthase. Of the 12 known gene classes involved in 1,4-β-xylan formation, XYS1/IRX10 in plants, IRX7, IRX8, IRX9, IRX14 and GUX occurred for the first time in charophyte algae. An XYS1/IRX10 ortholog from Klebsormidium flaccidum, designated K. flaccidumXYLAN SYNTHASE-1 (KfXYS1), possesses 1,4-β-xylan synthase activity, and 1,4-β-xylan occurs in the K. flaccidum cell wall. Finally, these data suggest that plant 1,4-β-xylan originated in charophytes and shed light on the origin of one of the key cell wall innovations to occur in charophyte algae, facilitating terrestrialization and emergence of polysaccharide-based plant cell walls.

  13. Daily home measurements of exhaled nitric oxide in asthmatic children during natural birch pollen exposure

    DEFF Research Database (Denmark)

    Vahlkvist, Signe; Sinding, Marianne; Skamstrup, Kirsten

    2006-01-01

    the feasibility, repeatability, accuracy, sensitivity, and biologic plausibility of new handheld equipment for FENO measurements. We studied day-to-day home measurements of FENO during the birch pollen season in children with allergy to birch pollen and a history of mild asthma and rhinoconjunctivitis during...... this season, as well as in nonatopic children. METHODS: Eleven children with mild asthma and allergy to birch pollen, performed daily home measurements of FENO for 6 weeks before and during the birch pollen season by using a handheld FENO monitor (NIOX MINO). Additionally, FENO (chemiluminescence equipment...... of FENO to a wider group of asthma clinics and even home measurements....

  14. Survival and growth for pubescent birch, pendula birch and common alder growing on farmland areas; Oeverlevnad och tillvaext hos glasbjoerk, vaartbjoerk och klibbal planterade paa aakermark

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Tord

    2000-07-01

    Pendula birches (Betula pendula Roth) and pubescent birches (Betula pubescens Ehrh.) were planted on former farmland. Before planting, the ground was harrowed or the ground was sprayed with terbuthylazine. Tree shelters were used as protection against weeds, voles and wild habitat. Birches treated with terbuthylazine showed the lowest survival. Birches growing in tree shelters were tallest and those growing on spots treated with terbuthylazine were smallest. The diameter at 0.1 m did not differ in a statistically significant way between the treatments. In another experiment with different herbicides, common alder (Alnus glutinosa (L.) Gaertn.) and pendula birch (Betula pendula Roth) were planted on former farmland that had been treated with glyphosate, terbuthylazine and propyzamide or after ground had been harrowed or not treated. In the study on herbicide-treated plants, birch had the highest plant survival. Mostly, species treated with glyphosate were thicker than species treated in other ways. Both species appeared sensitive to terbuthylazine, but not to glyphosate. Birch was not sensitive for propyzamide in opposite to alder. Some practical recommendations concerning afforestation of former farmland, especially weeding, are given.

  15. Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings

    Science.gov (United States)

    Sarah K. Poznanovic; Erik A. Lilleskov; Christopher R. Webster

    2015-01-01

    Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF) and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with...

  16. Conversion of xylan by recyclable spores of Bacillus subtilis displaying thermophilic enzymes.

    Science.gov (United States)

    Mattossovich, Rosanna; Iacono, Roberta; Cangiano, Giuseppina; Cobucci-Ponzano, Beatrice; Isticato, Rachele; Moracci, Marco; Ricca, Ezio

    2017-11-28

    The Bacillus subtilis spore has long been used to display antigens and enzymes. Spore display can be accomplished by a recombinant and a non-recombinant approach, with the latter proved more efficient than the recombinant one. We used the non-recombinant approach to independently adsorb two thermophilic enzymes, GH10-XA, an endo-1,4-β-xylanase (EC 3.2.1.8) from Alicyclobacillus acidocaldarius, and GH3-XT, a β-xylosidase (EC 3.2.1.37) from Thermotoga thermarum. These enzymes catalyze, respectively, the endohydrolysis of (1-4)-β-D-xylosidic linkages of xylans and the hydrolysis of (1-4)-β-D-xylans to remove successive D-xylose residues from the non-reducing termini. We report that both purified enzymes were independently adsorbed on purified spores of B. subtilis. The adsorption was tight and both enzymes retained part of their specific activity. When spores displaying either GH10-XA or GH3-XT were mixed together, xylan was hydrolysed more efficiently than by a mixture of the two free, not spore-adsorbed, enzymes. The high total activity of the spore-bound enzymes is most likely due to a stabilization of the enzymes that, upon adsorption on the spore, remained active at the reaction conditions for longer than the free enzymes. Spore-adsorbed enzymes, collected after the two-step reaction and incubated with fresh substrate, were still active and able to continue xylan degradation. The recycling of the mixed spore-bound enzymes allowed a strong increase of xylan degradation. Our results indicate that the two-step degradation of xylans can be accomplished by mixing spores displaying either one of two required enzymes. The two-step process occurs more efficiently than with the two un-adsorbed, free enzymes and adsorbed spores can be reused for at least one other reaction round. The efficiency of the process, the reusability of the adsorbed enzymes, and the well documented robustness of spores of B. subtilis indicate the spore as a suitable platform to display enzymes

  17. Simultaneous catalytic conversion of cellulose and corncob xylan under temperature programming for enhanced sorbitol and xylitol production.

    Science.gov (United States)

    Ribeiro, Lucília Sousa; Órfão, José J de Melo; Pereira, Manuel Fernando Ribeiro

    2017-11-01

    Sorbitol and xylitol yields can be improved by converting cellulose and xylan simultaneously, due to a synergetic effect between both substrates. Furthermore, both yields can be greatly enhanced by simply adjusting the reaction conditions regarding the optimum for the production of each product, since xylitol (from xylan) and sorbitol (from cellulose) yields are maximized when the reaction is carried out at 170 and 205°C, respectively. Therefore, the combination of a simultaneous conversion of cellulose and xylan with a two-step temperature approach, which consists in the variation of the reaction temperature from 170 to 205°C after 2h, showed to be a good strategy for maximizing the production of sorbitol and xylitol directly from mixture of cellulose and xylan. Using this new and environmentally friendly approach, yields of sorbitol and xylitol of 75 and 77%, respectively, were obtained after 6h of reaction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Fibrillar assembly of bacterial cellulose in the presence of wood-based hemicelluloses.

    Science.gov (United States)

    Penttilä, Paavo A; Imai, Tomoya; Sugiyama, Junji

    2017-09-01

    Composite materials mimicking the plant cell wall structure were made by culturing cellulose-producing bacteria together with secondary-wall hemicelluloses from wood. The effects of spruce galactoglucomannan (GGM) and beech xylan on the nanoscale morphology of bacterial cellulose were studied in the original, hydrated state with small-angle X-ray scattering (SAXS). The SAXS intensities were fitted with a model covering multiple levels of the hierarchical structure. Additional information on the structure of dried samples was obtained using scanning and transmission electron microscopy and infra-red spectroscopy. Both hemicelluloses induced a partial conversion of the cellulose crystal structure from I α to I β and a reduction of the cross-sectional dimensions of the cellulose microfibrils, thereby affecting also their packing into bundles. The differences were more pronounced in samples with xylan instead of GGM, and they became more significant with higher hemicellulose concentrations. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. 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.

  20. Integrated production of wood fuel and pulp wood from young stands; Integroitujen tuotantomenetelmien vertailu

    Energy Technology Data Exchange (ETDEWEB)

    Korpilahti, A [Metsaeteho Oy, Helsinki (Finland)

    1997-12-01

    The aim of the study was to clarify the competitiveness of different harvesting chains and processing methods of first thinning wood. Great expectations have been laid on integrated production of wood fuel and pulp wood. Results produced in other bioenergy projects were taken into account, and in this project some field experiments on mechanised felling-bunching and compressing of the load of tree sections during forwarding were carried out. The new processing methods, the MASSAHAKE-method and chain-flail delimbing combined with small-scale drum debarking, still are under development giving a rather unstable data for comparisons. Both in pine and birch dominant stands modern multiple tree logging gave the most favourable results when ranking on the bases of the price of pulp chips. Integrated methods were not very far and they have more potential than methods based on harvesting delimbed short wood. When compared on the bases of the production cost of pulp, integrated methods were in general the most favourable because they give good subsidies on the form of bioenergy. (orig.)

  1. Integrated production of merchantable wood and wood fuels in industry; Teollisuuden ainespuun ja puupolttoaineen integroitu tuotanto

    Energy Technology Data Exchange (ETDEWEB)

    Kuvaja, K [Enso Oy, Imatra (Finland). Forest Dept.

    1997-12-01

    The aim of this project is the economically profitable integrated harvesting of industrial wood and firewood especially in harvesting of small-diameter first thinning wood. The research in 1994 was concentrated on improvement of the quality of the chipping methods based on chain-flail debarking chipping method, and on determination of the possible utilisation targets for the fuel fraction. A reasonably large drum debarking test was also carried out at the industrial scale debarking station of the Enocell Oy. More than 80 000 m{sup 3} of first thinning wood was delivered by Enocell during this project. The quality of wood chips, produced using the chain-flail delimbing method, could be improved in the case of pine nearly to the required quality level, but additional measures are still needed in the case of birch. The fuel fraction deliveries to different points of utilisation was started. The particle size of the fuel fraction appeared to be good after crushing. In 1995 a chain-flail-drum debarking chipping unit was developed to improve and homogenise the quality of chips. (orig.)

  2. Differential response of Aspen and Birch trees to heat stress under elevated carbon dioxide

    Science.gov (United States)

    Joseph N.T. Darbah; Thomas D. Sharkey; Carlo Calfapietra; David F. Karnosky

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO2 protected photosynthesis of both species against moderate heat stress. Elevated CO...

  3. Impact of urbanization of the proteome of birch pollen and its chemotactic activity on human granulocytes

    NARCIS (Netherlands)

    Bryce, M.; Drews, O.; Schenk, M.F.; Menzel, A.; Estrella, N.; Weichenmeier, I.; Smulders, M.J.M.; Buters, J.; Ring, J.; Gorg, A.; Behrendt, H.; Traidl-Hoffmann, C.

    2010-01-01

    Background: Epidemiologic studies reveal a dramatic increase in allergies in the last decades. Air pollution is considered to be one of the factors responsible for this augmentation. The aim of this study was to analyze the impact of urbanization on birch pollen. The birch pollen proteome was

  4. Fertilization increases diameter growth of birch-beech-maple trees in New Hampshire

    Science.gov (United States)

    L. O. Safford

    1973-01-01

    In a 60-year-old northern hardwood stand treated with lime plus NPK fertilizer, the following increases in average basal area growth rate over untreated trees were observed: sugar maple 128 percent, paper birch 69 percent, yellow birch 51 percent, and beech 20 percent. Magnitude of response was inversely related to relative growth rate of the species. Growth rate...

  5. Defects in birch associated with injuries made by Xyloterinus politus Say.

    Science.gov (United States)

    Alex L. Shigo

    1966-01-01

    The purpose of this note is to give a brief pictorial description of the internal defects in paper birch (Betula papyrifera Marsh.) and yellow birch (B. alleghaniensis Britt.) that are associated with external signs of infestation by the ambrosia beetle Xyloterinus politus (fig. 1). The information was gained...

  6. Selective suppression of antibody production with the aid of radiolabelled birch pollen allergen

    International Nuclear Information System (INIS)

    Filipp, G.; Biro, G.; Hartung, W.D.; Lehmann, G.

    1981-01-01

    In accordance with the clonal selection theory we intended to prevent the development of artificially induced birch pollen allergy in rabbits with the aid of of the radiolabelled pollen allergen (75-1000 μCi 125 I-pollen/animal) intravenously administered prior to pollen sensitization. The birch pollen allergen, in accordance with Burnet's working hypothesis, reacts only with a genetically determining B cell subpopulation. The fixation of the radiolabelled birch pollen allergen to the receptors of the competent B cell clone causes the lesion of the latter. Compared with the control group, this group of rabbits showed an extensive suppression of anaphylactic reagin-like PCA-antibodies, and haemagglutinating antibodies in the blood as well as in nasal secretion. In addition, we tried to influence the already ongoing synthesis of the antibodies with the aid of a subsequent intravenously administered radiolabelled birch pollen allergen (750-1000μCi 125 I-pollen/animal). An intensive suppression of the synthesis of antibodies could also be proved in this case. The simultaneous immunization of the control rabbits with birch pollen and egg albumin resulted in the production of antibodies against both antigens, as expected. The hot-labelled birch pollen antigen intravenously injected before or after immunization with egg albumin and birch pollen led selectively to suppression of anti-birch-pollen PCA antibodies. The synthesis of anti-egg albumin PCA antibodies was unaffected. (author)

  7. A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

    OpenAIRE

    Weili Gong; Lin Dai; Huaiqiang Zhang; Lili Zhang; Lushan Wang; Lushan Wang

    2018-01-01

    Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secre...

  8. Biochemical and structural insights into xylan utilization by the thermophilic bacterium Caldanaerobius polysaccharolyticus.

    Science.gov (United States)

    Han, Yejun; Agarwal, Vinayak; Dodd, Dylan; Kim, Jason; Bae, Brian; Mackie, Roderick I; Nair, Satish K; Cann, Isaac K O

    2012-10-12

    Hemicellulose is the next most abundant plant cell wall component after cellulose. The abundance of hemicellulose such as xylan suggests that their hydrolysis and conversion to biofuels can improve the economics of bioenergy production. In an effort to understand xylan hydrolysis at high temperatures, we sequenced the genome of the thermophilic bacterium Caldanaerobius polysaccharolyticus. Analysis of the partial genome sequence revealed a gene cluster that contained both hydrolytic enzymes and also enzymes key to the pentose-phosphate pathway. The hydrolytic enzymes in the gene cluster were demonstrated to convert products from a large endoxylanase (Xyn10A) predicted to anchor to the surface of the bacterium. We further use structural and calorimetric studies to demonstrate that the end products of Xyn10A hydrolysis of xylan are recognized and bound by XBP1, a putative solute-binding protein, likely for transport into the cell. The XBP1 protein showed preference for xylo-oligosaccharides as follows: xylotriose > xylobiose > xylotetraose. To elucidate the structural basis for the oligosaccharide preference, we solved the co-crystal structure of XBP1 complexed with xylotriose to a 1.8-Å resolution. Analysis of the biochemical data in the context of the co-crystal structure reveals the molecular underpinnings of oligosaccharide length specificity.

  9. A molecular modeling approach to understand the structure and conformation relationship of (GlcpA)Xylan.

    Science.gov (United States)

    Guo, Qingbin; Kang, Ji; Wu, Yan; Cui, Steve W; Hu, Xinzhong; Yada, Rickey Y

    2015-12-10

    The structure and conformation relationships of a heteropolysaccharide (GlcpA)Xylan in terms of various molecular weights, Xylp/GlcpA ratio and the distribution of GlcpA along xylan chain were investigated using computer modeling. The adiabatic contour maps of xylobiose, XylpXylp(GlcpA) and (GlcpA)XylpXylp(GlcpA) indicated that the insertion of the side group (GlcpA) influenced the accessible conformational space of xylobiose molecule. RIS-Metropolis Monte Carlo method indicated that insertion of GlcpA side chain induced a lowering effect of the calculated chain extension at low GlcpA:Xylp ratio (GlcpA:Xylp = 1:3). The chain, however, became extended when the ratio of GlcpA:Xylp above 2/3. It was also shown that the spatial extension of the polymer chains was dependent on the distribution of side chain: the random distribution demonstrated the most flexible structure compared to block and alternative distribution. The present studies provide a unique insight into the dependence of both side chain ratio and distribution on the stiffness and flexibility of various (GlcpA)Xylan molecules. Copyright © 2015. Published by Elsevier Ltd.

  10. Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

    Directory of Open Access Journals (Sweden)

    Petersen Pia Damm

    2012-11-01

    Full Text Available Abstract Background Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production. Results Xylan is the major non-cellulosic polysaccharide in secondary cell walls, and the xylan deficient irregular xylem (irx mutants irx7, irx8 and irx9 exhibit severe dwarf growth phenotypes. The main reason for the growth phenotype appears to be xylem vessel collapse and the resulting impaired transport of water and nutrients. We developed a xylan-engineering approach to reintroduce xylan biosynthesis specifically into the xylem vessels in the Arabidopsis irx7, irx8 and irx9 mutant backgrounds by driving the expression of the respective glycosyltransferases with the vessel-specific promoters of the VND6 and VND7 transcription factor genes. The growth phenotype, stem breaking strength, and irx morphology was recovered to varying degrees. Some of the plants even exhibited increased stem strength compared to the wild type. We obtained Arabidopsis plants with up to 23% reduction in xylose levels and 18% reduction in lignin content compared to wild-type plants, while exhibiting wild-type growth patterns and morphology, as well as normal xylem vessels. These plants showed a 42% increase in saccharification yield after hot water pretreatment. The VND7 promoter yielded a more complete complementation of the irx phenotype than the VND6 promoter. Conclusions Spatial and temporal deposition of xylan in the secondary cell wall of

  11. Choosing Wood Burning Appliances

    Science.gov (United States)

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

  12. Are the birch trees in Southern England a source of Betula pollen for North London?

    Science.gov (United States)

    Skjøth, C. A.; Smith, M.; Brandt, J.; Emberlin, J.

    2009-01-01

    Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts ( n = 60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200-0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

  13. Molecular passportization of clones of karelian birch using PCRwith semi-specific primers

    Directory of Open Access Journals (Sweden)

    Tatyana V Matveeva

    2008-09-01

    Full Text Available Using 4 clones of Karelian birch (Betula pendula Roth var caretica Merckl. from the collection of the karelian birch of the laboratory of genetics of Research Institute of Forest Genetics and Breeding, Voronezh, one normal tree of Betula pendula Roth, and one tree of B. pubescens Ehrh., collected from the nature, we have analyzed the possibility of application of PCR with semi-specific primers for molecular typing. We found primers with high percentage of polymorphic markers. These primers could be recommended for molecular typing of birch.

  14. Short-rotation forestry of birch, maple, poplar and willow in Flanders (Belgium) II. Energy production and CO2 emission reduction potential

    International Nuclear Information System (INIS)

    Walle, Inge van de; Camp, Nancy van; Casteele, Liesbet van de; Verheyen, Kris; Lemeur, Raoul

    2007-01-01

    Belgium, being an EU country, has committed itself to a 7.5% reduction of greenhouse gas emissions during the first commitment period of the Kyoto Protocol. Within this framework, the Flemish government aims at reaching a share of 6% of renewable electricity in the total electricity production by 2010. In this work, the biomass production of birch, maple, poplar and willow in a short-rotation forestry (SRF) plantation after a 4-year growth period served as the base to calculate the amount of (electrical) energy that could be produced by this type of bioenergy crop in Flanders. The maximum amount of electricity that could be provided by SRF biomass was estimated at 72.9 GWh e year -1 , which only accounts for 0.16% of the total electricity production in this region. Although the energy output was rather low, the bioenergy production process under consideration appeared to be more energy efficient than energy production processes based on fossil fuels. The high efficiency of birch compared to the other species was mainly due to the high calorific value of the birch wood. The maximum CO 2 emission reduction potential of SRF plantations in Flanders was estimated at only 0.09% of the total annual CO 2 emission. The most interesting application of SRF in Flanders seemed to be the establishment of small-scale plantations, linked to a local combined heat and power plant. These plantations could be established on marginal arable soils or on polluted sites, and they could be of importance in the densely populated area of Flanders because of other environmental benefits, among which their function as (temporary) habitat for many species

  15. Hardrock Elastic Physical Properties: Birch's Seismic Parameter Revisited

    Science.gov (United States)

    Wu, M.; Milkereit, B.

    2014-12-01

    Identifying rock composition and properties is imperative in a variety of fields including geotechnical engineering, mining, and petroleum exploration, in order to accurately make any petrophysical calculations. Density is, in particular, an important parameter that allows us to differentiate between lithologies and estimate or calculate other petrophysical properties. It is well established that compressional and shear wave velocities of common crystalline rocks increase with increasing densities (i.e. the Birch and Nafe-Drake relationships). Conventional empirical relations do not take into account S-wave velocity. Physical properties of Fe-oxides and massive sulfides, however, differ significantly from the empirical velocity-density relationships. Currently, acquiring in-situ density data is challenging and problematic, and therefore, developing an approximation for density based on seismic wave velocity and elastic moduli would be beneficial. With the goal of finding other possible or better relationships between density and the elastic moduli, a database of density, P-wave velocity, S-wave velocity, bulk modulus, shear modulus, Young's modulus, and Poisson's ratio was compiled based on a multitude of lab samples. The database is comprised of isotropic, non-porous metamorphic rock. Multi-parameter cross plots of the various elastic parameters have been analyzed in order to find a suitable parameter combination that reduces high density outliers. As expected, the P-wave velocity to S-wave velocity ratios show no correlation with density. However, Birch's seismic parameter, along with the bulk modulus, shows promise in providing a link between observed compressional and shear wave velocities and rock densities, including massive sulfides and Fe-oxides.

  16. Establishing correspondence in wood: the challenge and some solutions?

    Science.gov (United States)

    Courtin, Gerard M; Fairgrieve, Scott I

    2013-09-01

    Establishing correspondence between the upper portion of a white birch sapling, a suspected weapon, and a potential source from a stand of trees was posed to one of us (GMC). A bending force shattered the sapling, precluding physical matching. Three white birch saplings were taken from the same stand of trees in a similar manner. Correspondence was achieved by measuring the width of the annual rings along four radii from a disk cut above and below the break. The regression coefficient of the data from the two disks from the same sapling was r(2) = 0.95. Regressing the upper disk against the lower disk of two other saplings resulted in r(2) values of 0.26 and 0.17, respectively. The various characteristics that are confined to a wood stem as part of its normal process of growth can be used to eliminate candidate saplings and establish correspondence between two pieces of wood. © 2013 American Academy of Forensic Sciences.

  17. Effect of pH on production of xylanase by Trichoderma reesei on xylan- and cellulose-based media

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, M.J. (VTT, Biotechnical Lab., Espoo (Finland)); Buchert, J. (VTT, Biotechnical Lab., Espoo (Finland)); Viikari, L. (VTT, Biotechnical Lab., Espoo (Finland))

    1993-11-01

    Trichoderma reesei VTT-D-86271 (Rut C-30) was cultivated on media based on cellulose and xylan as the main carbon source in fermentors with different pH minimum controls. Production of xylanase was favoured by a rather high pH minimum control between 6.0 and 7.0 on both cellulose- and xylan-based media. Although xylanase was produced efficiently on cellulose as well as on xylan as the carbon source, significant production of cellulase was observed only on the cellulose-based medium and best production was at lower pH (4.0 minimum). Production of xylanase at pH 7.0 was shown to be dependent on the nature of the xylan in the cultivation medium but was independent of other organic components. Best production of xylanase was observed on insoluble, unsubstituted beech xylan at pH 7.0. Similar results were obtained in laboratory and pilot (200-1) fermentors. Downstream processing of the xylanase-rich, low-cellulase culture filtrate presented no technical problems despite apparent autolysis of the fungus at the high pH. Enzyme produced in the 200-1 pilot fermentor was shown to be suitable for use in enzyme-aided bleaching of kraft pulp. Due to the high xylanase/cellulase ratio of enzyme activities in the culture filtrate, pretreatment for removal of cellulase activity prior to pulp bleaching was unnecessary. (orig.)

  18. Effect of xylan and lignin removal by batch and flowthrough pretreatment on the enzymatic digestibility of corn stover cellulose.

    Science.gov (United States)

    Yang, Bin; Wyman, Charles E

    2004-04-05

    Compared with batch systems, flowthrough and countercurrent reactors have important potential advantages for pretreating cellulosic biomass, including higher hemicellulose sugar yields, enhanced cellulose digestibility, and reduced chemical additions. Unfortunately, they suffer from high water and energy use. To better understand these trade-offs, comparative data are reported on xylan and lignin removal and enzymatic digestibility of cellulose for corn stover pretreated in batch and flowthrough reactors over a range of flow rates between 160 degrees and 220 degrees C, with water only and also with 0.1 wt% sulfuric acid. Increasing flow with just water enhanced the xylan dissolution rate, more than doubled total lignin removal, and increased cellulose digestibility. Furthermore, adding dilute sulfuric acid increased the rate of xylan removal for both batch and flowthrough systems. Interestingly, adding acid also increased the lignin removal rate with flow, but less lignin was left in solution when acid was added in batch. Although the enzymatic hydrolysis of pretreated cellulose was related to xylan removal, as others have shown, the digestibility was much better for flowthrough compared with batch systems, for the same degree of xylan removal. Cellulose digestibility for flowthrough reactors was related to lignin removal as well. These results suggest that altering lignin also affects the enzymatic digestibility of corn stover. Copyright 2004 Wiley Periodicals, Inc.

  19. Characterization of xylan in the early stages of secondary cell wall formation in tobacco bright yellow-2 cells.

    Science.gov (United States)

    Ishii, Tadashi; Matsuoka, Keita; Ono, Hiroshi; Ohnishi-Kameyama, Mayumi; Yaoi, Katsuro; Nakano, Yoshimi; Ohtani, Misato; Demura, Taku; Iwai, Hiroaki; Satoh, Shinobu

    2017-11-15

    The major polysaccharides present in the primary and secondary walls surrounding plant cells have been well characterized. However, our knowledge of the early stages of secondary wall formation is limited. To address this, cell walls were isolated from differentiating xylem vessel elements of tobacco bright yellow-2 (BY-2) cells induced by VASCULAR-RELATED NAC-DOMAIN7 (VND7). The walls of induced VND7-VP16-GR BY-2 cells consisted of cellulose, pectic polysaccharides, hemicelluloses, and lignin, and contained more xylan and cellulose compared with non-transformed BY-2 and uninduced VND7-VP16-GR BY-2 cells. A reducing end sequence of xylan containing rhamnose and galaturonic acid- residues is present in the walls of induced, uninduced, and non-transformed BY-2 cells. Glucuronic acid residues in xylan from walls of induced cells are O-methylated, while those of xylan in non-transformed BY-2 and uninduced cells are not. Our results show that xylan changes in chemical structure and amounts during the early stages of xylem differentiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Finishing of wood

    Science.gov (United States)

    R. Sam Williams

    1999-01-01

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

  1. Metagenomic and functional analysis of hindgut microbiota of a wood-feeding higher termite

    Energy Technology Data Exchange (ETDEWEB)

    Warnecke, Falk; Warnecke, Falk; Luginbuhl, Peter; Ivanova, Natalia; Ghassemian, Majid; Richardson, Toby H.; Stege, Justin T.; Cayouette, Michelle; McHardy, Alice C.; Djordjevic, Gordana; Aboushadi, Nahla; Sorek, Rotem; Tringe, Susannah G.; Podar, Mircea; Martin, Hector Garcia; Kunin, Victor; Dalevi, Daniel; Madejska, Julita; Kirton, Edward; Platt, Darren; Szeto, Ernest; Salamov, Asaf; Barry, Kerrie; Mikhailova, Natalia; Kyrpides, Nikos C.; Matson, Eric G.; Ottesen, Elizabeth A.; Zhang, Xinning; Hernandez, Myriam; Murillo, Catalina; Acosta, Luis G.; Rigoutsos, Isidore; Tamayo, Giselle; Green, Brian D.; Chang, Cathy; Rubin, Edward M.; Mathur, Eric J.; Robertson, Dan E.; Hugenholtz, Philip; Leadbetter, Jared R.

    2007-10-01

    From the standpoints of both basic research and biotechnology, there is considerable interest in reaching a clearer understanding of the diversity of biological mechanisms employed during lignocellulose degradation. Globally, termites are an extremely successful group of wood-degrading organisms and are therefore important both for their roles in carbon turnover in the environment and as potential sources of biochemical catalysts for efforts aimed at converting wood into biofuels. Only recently have data supported any direct role for the symbiotic bacteria in the gut of the termite in cellulose and xylan hydrolysis. Here we use a metagenomic analysis of the bacterial community resident in the hindgut paunch of a wood-feeding Nasutitermes species to show the presence of a large, diverse set of bacterial genes for cellulose and xylan hydrolysis. Many of these genes were expressed in vivo or had cellulase activity in vitro, and further analyses implicate spirochete and fibrobacter species in gut lignocellulose degradation. New insights into other important symbiotic functions including H{sub 2} metabolism, CO{sub 2}-reductive acetogenesis and N{sub 2} fixation are also provided by this first system-wide gene analysis of a microbial community specialized towards plant lignocellulose degradation. Our results underscore how complex even a 1-{micro}l environment can be.

  2. Xylan oligosaccharides and cellobiohydrolase I (TrCel7A interaction and effect on activity

    Directory of Open Access Journals (Sweden)

    Baumann Martin J

    2011-10-01

    Full Text Available Abstract Background The well-studied cellulase mixture secreted by Trichoderma reesei (anamorph to Hypocrea jecorina contains two cellobiohydolases (CBHs, cellobiohydrolase I (TrCel7A and cellobiohydrolase II (TrCeI6A, that are core enzymes for the solubilisation of cellulose. This has attracted significant research interest because of the role of the CBHs in the conversion of biomass to fermentable sugars. However, the CHBs are notoriously slow and susceptible to inhibition, which presents a challenge for the commercial utilisation of biomass. The xylans and xylan fragments that are also present in the biomass have been suggested repeatedly as one cause of the reduced activity of CHBs. Yet, the extent and mechanisms of this inhibition remain poorly elucidated. Therefore, we studied xylan oligosaccharides (XOSs of variable lengths with respect to their binding and inhibition of both TrCel7A and an enzyme variant without the cellulose-binding domain (CBM. Results We studied the binding of XOSs to TrCel7A by isothermal titration calorimetry. We found that XOSs bind to TrCel7A and that the affinity increases commensurate with XOS length. The CBM, on the other hand, did not affect the affinity significantly, which suggests that XOSs may bind to the active site. Activity assays of TrCel7A clearly demonstrated the negative effect of the presence of XOSs on the turnover number. Conclusions On the basis of these binding data and a comparison of XOS inhibition of the activity of the two enzyme variants towards, respectively, soluble and insoluble substrates, we propose a competitive mechanism for XOS inhibition of TrCel7A with phosphoric swollen cellulose as a substrate.

  3. Who's Counting Dead Wood ?

    OpenAIRE

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

    2009-01-01

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

  4. Correlation between the morphogenetic types of litter and their properties in bog birch forests

    Science.gov (United States)

    Efremova, T. T.; Efremov, S. P.; Avrova, A. F.

    2010-08-01

    A formalized arrangement of morphogenetic types of litter according to the physicochemical parameters provided their significant grouping in three genetic associations. The litter group (highly decomposed + moderately decomposed) is confined to the tall-grass group of bog birch forests. The rhizomatous (roughly decomposed) litter is formed in the sedge-reed grass bog birch forests. The litter group (peaty + peatified + peat) is associated with the bog-herbaceous-moss group of forest types. The genetic associations of the litters (a) reliably characterize the edaphic conditions of bog birch forests and (b)correspond to formation of the peat of certain ecological groups. We found highly informative the acid-base parameters, the exchangeable cations (Ca2+ + Mg2+) and the total potential acidity, which differentiated the genetic associations of litter practically with 100% probability. The expediency of studying litters under groups of forest types rather than under separate types of bog birch forests was demonstrated.

  5. Determination of some significant batch culture conditions affecting acetyl-xylan esterase production by Penicillium notatum NRRL-1249

    Directory of Open Access Journals (Sweden)

    Akhtar MN

    2011-05-01

    Full Text Available Abstract Background Acetyl-xylan esterase (AXE, EC 3.1.1.72 hydrolyses acetate group from the linear chain of xylopyranose residues bound by β-1,4-linkage. The enzyme finds commercial applications in bio-bleaching of wood pulp, treating animal feed to increase digestibility, processing food to increase clarification and converting lignocellulosics to feedstock and fuel. In the present study, we report on the production of an extracellular AXE from Penicillium notatum NRRL-1249 by solid state fermentation (SSF. Results Wheat bran at a level of 10 g (with 4 cm bed height was optimized as the basal substrate for AXE production. An increase in enzyme activity was observed when 7.5 ml of mineral salt solution (MSS containing 0.1% KH2PO4, 0.05% KCl, 0.05% MgSO4.7H2O, 0.3% NaNO3, 0.001% FeSO4.2H2O and 0.1% (v/w Tween-80 as an initial moisture content was used. Various nitrogen sources including ammonium sulphate, urea, peptone and yeast extract were compared for enzyme production. Maximal enzyme activity of 760 U/g was accomplished which was found to be highly significant (p ≤ 0.05. A noticeable enhancement in enzyme activity was observed when the process parameters including incubation period (48 h, initial pH (5, 0.2% (w/w urea as nitrogen source and 0.5% (v/w Tween-80 as a stimulator were further optimized using a 2-factorial Plackett-Burman design. Conclusion From the results it is clear that an overall improvement of more than 35% in terms of net enzyme activity was achieved compared to previously reported studies. This is perhaps the first report dealing with the use of P. notatum for AXE production under batch culture SSF. The Plackett-Burman model terms were found highly significant (HS, suggesting the potential commercial utility of the culture used (df = 3, LSD = 0.126.

  6. Direct hydrodeoxygenation of cellulose and xylan to lower alkanes on ruthenium catalysts in subcritical water

    International Nuclear Information System (INIS)

    Osaka, Yuriko; Ikeda, Yoichi; Hashizume, Daisuke; Iwamoto, Masakazu

    2013-01-01

    Nano particles of Ru, Rh, Pd, Ir, Pt, and Au, protected by polyvinyl pyrrolidone (PVP), were applied to the hydrodeoxygenation of cellulose and xylan in water and 5 MPa H 2 at 543 K. The distributions of products generated from cellulose and xylan were roughly similar to each other under the present reaction conditions, and therefore, the former was intensively studied. The Ru-PVP catalyst afforded mainly methane and lower alkanes, rather than producing water soluble organic compounds, such as diols and alcohols, that were formed with the use of the other catalysts. The changes in the product distributions with reaction temperature and time indicated that the reaction consisted of two consecutive reactions: cellulose or xylan → water soluble compounds → hydrogenolysis. The first transformation was promoted in subcritical water, and the second step was catalyzed by the Ru catalyst. The Ru catalyst that was supported on CeO 2 , γ-Al 2 O 3 , or activated carbon yielded a similar product distribution to that on Ru-PVP; however, the loading of Ru on TiO 2 , ZrO 2 , SiO 2 –Al 2 O 3 , or SiO 2 resulted in the increment of diols. After the reaction a small portion of the CeO 2 and most of the SiO 2 –Al 2 O 3 and SiO 2 were dissolved in water, and a portion of the Al 2 O 3 was transformed to boehmite AlO(OH) from the γ-alumina. Little change in the catalytic activity however was observed upon the reuse of Ru/Al 2 O 3 in the second run. Highlights: •One-path hydrodeoxygenation of cellulose and xylan to methane and lower alkanes was studied. •Ru-PVP catalysts gave the best yields among Ru-, Rh-, Pd-, Ir-, Pt-, and Au-PVP. •The reaction pathways were cellulose → water soluble compounds → hydrogenolysis. •The catalytic activity of Ru was greatly dependent on the supports

  7. Engineering of plants with improved properties as biofuels feedstocks by vessel-specific complementation of xylan biosynthesis mutants

    DEFF Research Database (Denmark)

    Petersen, Pia; Lau, Jane; Ebert, Berit

    2012-01-01

    Background: Cost-efficient generation of second-generation biofuels requires plant biomass that can easily be degraded into sugars and further fermented into fuels. However, lignocellulosic biomass is inherently recalcitrant toward deconstruction technologies due to the abundant lignin and cross......-linked hemicelluloses. Furthermore, lignocellulosic biomass has a high content of pentoses, which are more difficult to ferment into fuels than hexoses. Engineered plants with decreased amounts of xylan in their secondary walls have the potential to render plant biomass a more desirable feedstock for biofuel production...... in the xylem vessels is sufficient to complement the irx phenotype of xylan deficient mutants, while maintaining low overall amounts of xylan and lignin in the cell wall. This engineering approach has the potential to yield bioenergy crop plants that are more easily deconstructed and fermented into biofuels....

  8. Vegetation of birch and aspen forests in the Pinega State Reserve

    Directory of Open Access Journals (Sweden)

    Sergey Yu. Popov

    2017-05-01

    Full Text Available The Pinega State Nature Reserve (Russia is located in the Arkhangelsk region in the northern taiga subzone. Together with spruce forests and mires, birch forests represent one of the most wide-spread plant communities of its territory. Birch forests cover 24.6% of the Reserve's area. Aspen forests are rare plant communities in the Pinega Reserve. These forests cover only 0.9% of the whole Reserve's area. The birch and aspen forests vegetation has been classified based on 82 relevès. Eleven associations could be distinguished, which represent six groups of associations. Detailed characteristics of these syntaxa are provided including their biodiversity analysis. The analysis allowed establishing that the revealed syntaxa differ in relation to habitat environmental conditions: e.g., soil moisture, trophicity, nitrogen saturation and soil acidity. Sphagnum and blueberry birch forests proved to be the poorest in nitrogen, in contrast to the richest humidoherbaceous and broad-grassed groups of birch forest associations. Broad-grassed birch forests in the Pinega Reserve inhabit the most drained locations, while humidoherbaceous and Sphagnum forests occur in lesser drained locations.

  9. Green synthesis of silver nanoparticles in xylan solution via Tollens reaction and their detection for Hg(2+).

    Science.gov (United States)

    Luo, Yuqiong; Shen, Suqin; Luo, Jiwen; Wang, Xiaoying; Sun, Runcang

    2015-01-14

    This work reported a facile and green method to prepare highly stable and uniformly distributed Ag nanoparticles (AgNPs), in which a biopolymer xylan was used as the stabilizing and reducing agent via the Tollens reaction under microwave irradiation. Different variables were evaluated to optimize the reaction conditions. Complete characterization was performed using UV-Vis, XRD, TEM, size distribution analysis and XPS. The results revealed that AgNPs were well dispersed with diameters of 20-35 nm due to the packing of xylan. The optimal conditions were as follows: microwave irradiation temperature was 60-70 °C, microwave power was 800 W, microwave time was 30 min, the ratio of xylan to AgNO3 was 50 mg: 0.13 mmol, and ammonia concentration was 2%. In addition, the AgNPs were collected via high-speed centrifugal separation, and the supernatant was tested by HPAEC, GPC, FT-IR, and NMR. By comparing the structure of xylan before and after the reaction, the reaction mechanism was discussed. It was noted that the xylan-AgNPs composites showed high selectivity and sensitivity for Hg(2+) detection. The other 15 metal ions used had no obvious effect on the detection of Hg(2+), and the limit of detection (LOD) was 4.6 nM, which is lower than the allowed maximum level of 30 nM for drinking water by WHO. In addition, the xylan-AgNPs composites can be applied for Hg(2+) detection in real water samples. This study provides a novel way for the high-value utilization of a rich biomass resource, and a green method for the synthesis of AgNPs for the selective and sensitive detection of harmful heavy metals.

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

    Science.gov (United States)

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

    2014-06-01

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

  11. Start-up emissions from residential down-draught wood log boilers

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, E. (Luleaa Univ. of Technology (Sweden). Energy Technology Centre in Piteaa), Email: esbjorn.pettersson@ltu.se

    2009-07-01

    Start-up emissions can be substantial and even dominating in real use. There are few published investigations regarding the relative importance of different parameters on the start-up emissions. It has though recently been stated that for down-draught boilers, best results are achieved if the wood charge is ignited fairly close to the secondary chamber. The objective of the experimental work was to evaluate the effect of different fuel and design parameters on the start-up emissions, using experimental design which enables a direct comparison between different parameters, using three levels of preheating of secondary air, electric preheating of primary air, different moisture and size of the start wood as well as different amounts of birch bark, which was used to spread the fire during the start. The boiler did not use a bypass damper and the full fuel charge was added before igniting the start wood through an ignition door situated slightly above the grate. The only significant results for the four parameters were that smaller and drier start wood gave lower start-up emissions. Extra amount of birch bark gave the same result. The most important parameters are the fuel parameters, which mean that the result is generally applicable. (orig.)

  12. Deciduous birch canopy as unexpected contributor to stand level atmospheric reactivity in boreal forests

    Science.gov (United States)

    Bäck, Jaana; Taipale, Ditte; Aalto, Juho

    2017-04-01

    In boreal forests, deciduous trees such as birches may in future climate become more abundant due to their large biomass production capacity, relatively good resource use ability and large acclimation potential to elevated CO2 levels and warmer climate. Increase in birch abundance may lead to unpredicted consequences in atmospheric composition. Currently it is acknowledged that conifers such as Scots pine and Norway spruce are important sources for volatile organic compounds (VOCs), especially monoterpenes, throughout the year, although the strong temperature relationships implies that emissions are highest in summertime. However, the dynamics of the deciduous birch foliage VOC emissions and their relationship with environmental drivers during the development, maturation and senescence of foliage has not been well analyzed. Long-term measurements of birch, which are unfortunately very sparse, can provide very useful information for the development of biosphere-atmosphere models that simulate boreal and subarctic forested areas where birch is often a sub-canopy species, occurs as a mixture among conifers or forms even pure stands in the higher latitudes. We measured the branch level VOC emissions from a mature Silver birch with proton transfer reaction mass spectrometer during 2014 and 2015 at the SMEAR II station (Station for Measuring Ecosystem-Atmosphere Relations), southern Finland. Our results showed that the Silver birch foliage is a huge source for both short-chained volatiles such as methanol, acetaldehyde and acetone, as well as for monoterpenes. The mean emission rates from birch leaves were 5 to 10 times higher than the corresponding emissions from Scots pine shoots. We compared several semi-empirical model approaches for determining the birch foliage monoterpene standardized emission potentials, and utilized the continuous emission measurements from the two growing seasons for development of a novel algorithm which accounts for the leaf development and

  13. The impact of birch seedlings on evapotranspiration from a mined peatland: an experimental study in southern Quebec, Canada

    Directory of Open Access Journals (Sweden)

    E. Fay

    2009-03-01

    Full Text Available Dense stands of birch (Betula spp. on abandoned peat workings have often been identified as potential barriers to site restoration, but little research has been conducted to evaluate their impact on water resources. The objective of this experimental study was to determine whether birch seedlings established on an abandoned mined peatland in eastern Canada had a significant impact on evapotranspiration. Transpiration rates from birch seedlings planted in containers filled with Sphagnum compost were measured gravimetrically. Unplanted containers were used to similarly measure evaporation rates from bare peat. On average, the measured rates of evaporation (per unit area from peat were 2.5 times the rates of transpiration from birch leaves. However, if the total leaf area of a dense birch population established on an abandoned mined peatland is considered, the total amount of water lost through birch transpiration could be higher than that lost by evaporation from the peat surface. This study provides a rough estimate of potential water losses due to birch seedling transpiration, and indicates that a dense population of birch on a mined peatland may influence site hydrology even at the early establishment phase (seedlings. Consequently, recently abandoned mined peatlands should be restored rapidly to prevent the establishment of birch trees.

  14. Responses of human birch pollen allergen-reactive T cells to chemically modified allergens (allergoids).

    Science.gov (United States)

    Dormann, D; Ebner, C; Jarman, E R; Montermann, E; Kraft, D; Reske-Kunz, A B

    1998-11-01

    Allergoids are widely used in specific immunotherapy for the treatment of IgE-mediated allergic diseases. The aim of this study was to analyse whether a modification of birch pollen allergens with formaldehyde affects the availability of T-cell epitopes. Efficient modification of the allergens was verified by determining IgE and IgG binding activity using ELISA inhibition tests. T-cell responses to birch pollen allergoids were analysed in polyclonal systems, using peripheral blood mononuclear cells (PBMC) of five birch pollen-allergic individuals, as well as birch pollen extract-reactive T-cell lines (TCL), established from the peripheral blood of 14 birch pollen-allergic donors. To determine whether the modification of natural (n)Bet v 1 with formaldehyde or maleic anhydride results in epitope-specific changes in T-cell reactivities, 22 Bet v 1-specific T-cell clones (TCC), established from nine additional birch pollen-allergic individuals, were tested for their reactivity with these products. The majority of PBMC and TCL showed a reduced response to the birch pollen extract allergoid. Bet v 1-specific TCC could be divided into allergoid-reactive and -non-reactive TCC. No simple correlation between possible modification sites of formaldehyde in the respective T-cell epitopes and the stimulatory potential of the allergoid was observed. Mechanisms of suppression or of anergy induction were excluded as an explanation for the non-reactivity of representative TCC. All TCC could be stimulated by maleylated and unmodified nBet v 1 to a similar extent. These results demonstrate differences in the availability of T-cell epitopes between allergoids and unmodified allergens, which are most likely due to structural changes within the allergen molecule.

  15. Integrated production of merchantable wood and wood fuels in industry; Teollisuuden ainespuun ja puupoltto-aineen integroitu tuotanto

    Energy Technology Data Exchange (ETDEWEB)

    Kuvaja, K. [Enso-Gutzeit Oy, Imatra (Finland). Forest Dept.

    1996-12-31

    The aim of this project is the economically profitable integrated harvesting of industrial wood and firewood especially in harvesting of small-diameter first thinning wood. The research in 1994 was concentrated on improvement of the quality of the chipping methods based on chain-flail debarking chipping method, and on determination of the possible utilization targets for the fuel fraction. A reasonably large drum debarking test was also carried out at the industrial scale debarking station of the Enocell Oy. More than 80 000 m{sup 3} of first thinning wood was delivered by Enocell during this project. The quality of wood chips, produced using the chain-flail delimbing method, could be improved in the case of pine nearly to the required quality level, but additional measures are still needed in the case of birch. The fuel fraction deliveries to different points of utilization was started. The particle size of the fuel fraction appeared to be good after crushing. In 1995 a chain-flail-dry drum debarking chipping unit was developed to improve and homogenize the quality of chips

  16. Integrated production of merchantable wood and wood fuels in industry; Teollisuuden ainespuun ja puupoltto-aineen integroitu tuotanto

    Energy Technology Data Exchange (ETDEWEB)

    Kuvaja, K [Enso-Gutzeit Oy, Imatra (Finland). Forest Dept.

    1997-12-31

    The aim of this project is the economically profitable integrated harvesting of industrial wood and firewood especially in harvesting of small-diameter first thinning wood. The research in 1994 was concentrated on improvement of the quality of the chipping methods based on chain-flail debarking chipping method, and on determination of the possible utilization targets for the fuel fraction. A reasonably large drum debarking test was also carried out at the industrial scale debarking station of the Enocell Oy. More than 80 000 m{sup 3} of first thinning wood was delivered by Enocell during this project. The quality of wood chips, produced using the chain-flail delimbing method, could be improved in the case of pine nearly to the required quality level, but additional measures are still needed in the case of birch. The fuel fraction deliveries to different points of utilization was started. The particle size of the fuel fraction appeared to be good after crushing. In 1995 a chain-flail-dry drum debarking chipping unit was developed to improve and homogenize the quality of chips

  17. Wood-plastic combination

    International Nuclear Information System (INIS)

    Schaudy, R.

    1978-02-01

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

  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. Wood's lamp examination

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003386.htm Wood lamp examination To use the sharing features on this page, please enable JavaScript. A Wood lamp examination is a test that uses ultraviolet ( ...

  20. Wood's lamp illumination (image)

    Science.gov (United States)

    A Wood's lamp emits ultraviolet light and can be a diagnostic aid in determining if someone has a fungal ... is an infection on the area where the Wood's lamp is illuminating, the area will fluoresce. Normally ...

  1. Robert Wood Johnson Foundation

    Science.gov (United States)

    Robert Wood Johnson Foundation Search How We Work Our Focus Areas About RWJF Search Menu How We Work Grants ... Learn more For Grantees and Grantseekers The Robert Wood Johnson Foundation funds a wide array of programs ...

  2. Non_standard Wood

    DEFF Research Database (Denmark)

    Tamke, Martin

    . Using parametric design tools and computer controlled production facilities Copenhagens Centre for IT and Architecture undertook a practice based research into performance based non-standard element design and mass customization techniques. In close cooperation with wood construction software......, but the integration of traditional wood craft techniques. The extensive use of self adjusting, load bearing wood-wood joints contributed to ease in production and assembly of a performance based architecture....

  3. Construction of low-cost, Mod-OA wood composite wind turbine blades

    Science.gov (United States)

    Lark, R. F.

    1983-01-01

    Two sixty-foot, low-cost, wood composite blades for service on 200 kW Mod-OA wind turbines were constructed. The blades were constructed of epoxy resin-bonded Douglas fir veneers for the leading edge sections, and paper honeycombcored, birch plywood faced panels for the afterbody sections. The blades were joined to the wind turbine hub by epoxy resin-bonded steel load take-off studs embedded into the root end of the blades. The blades were installed on the 200 kW Mod-OA wind turbine facility at Kahuku, Hawaii, The blades completed nearly 8,000 hours of operation over an 18 month period at an average power of 150 kW prior to replacement with another set of wood composite blades. The blades were replaced because of a corrosion failure of the steel shank on one stud. Inspections showed that the wood composite structure remained in excellent condition.

  4. Xylan utilization in human gut commensal bacteria is orchestrated by unique modular organization of polysaccharide-degrading enzymes

    KAUST Repository

    Zhang, Meiling; Chekan, Jonathan R.; Dodd, Dylan; Hong, Pei-Ying; Radlinsk, Lauren; Revindran, Vanessa; Nair, Satish K.; Mackie, Roderick Ian; Cann, Isaac Ko O

    2014-01-01

    highly induced carbohydrate active genes encode a unique glycoside hydrolase (GH) family 10 endoxylanase (BiXyn10A or BACINT-04215 and BACOVA-04390) that is highly conserved in the Bacteroidetes xylan utilization system. The BiXyn10A modular architecture

  5. Adhesive interactions with wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    While the chemistry for the polymerization of wood adhesives has been studied systematically and extensively, the critical aspects of the interaction of adhesives with wood are less clearly understood. General theories of bond formation need to be modified to take into account the porosity of wood and the ability of chemicals to be absorbed into the cell wall....

  6. Soil-wood interactions

    NARCIS (Netherlands)

    Wal, van der Annemieke; klein Gunnewiek, Paulien; Boer, de Wietse

    2017-01-01

    Wood-inhabiting fungi may affect soil fungal communities directly underneath decaying wood via their exploratory hyphae. In addition, differences in wood leachates between decaying tree species may influence soil fungal communities. We determined the composition of fungi in 4-yr old decaying logs

  7. 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...

  8. Wood preservative testing

    Science.gov (United States)

    Rebecca Ibach; Stan T. Lebow

    2012-01-01

    Most wood species used in commercial and residential construction have little natural biological durability and will suffer from biodeterioration when exposed to moisture. Historically, this problem has been overcome by treating wood for outdoor use with toxic wood preservatives. As societal acceptance of chemical use changes, there is continual pressure to develop and...

  9. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Roger M. Rowell

    2010-01-01

    The wood industry can expand into new sustainable markets with the formation of a new class of composites with the marriage of the wood industry and the plastics industry. The wood component, usually a flour or fiber, is combined with a thermoplastic to form an extrudable, injectable or thermoformable composite that can be used in many non-structural applications....

  10. 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

  11. m-BIRCH: an online clustering approach for computer vision applications

    Science.gov (United States)

    Madan, Siddharth K.; Dana, Kristin J.

    2015-03-01

    We adapt a classic online clustering algorithm called Balanced Iterative Reducing and Clustering using Hierarchies (BIRCH), to incrementally cluster large datasets of features commonly used in multimedia and computer vision. We call the adapted version modified-BIRCH (m-BIRCH). The algorithm uses only a fraction of the dataset memory to perform clustering, and updates the clustering decisions when new data comes in. Modifications made in m-BIRCH enable data driven parameter selection and effectively handle varying density regions in the feature space. Data driven parameter selection automatically controls the level of coarseness of the data summarization. Effective handling of varying density regions is necessary to well represent the different density regions in data summarization. We use m-BIRCH to cluster 840K color SIFT descriptors, and 60K outlier corrupted grayscale patches. We use the algorithm to cluster datasets consisting of challenging non-convex clustering patterns. Our implementation of the algorithm provides an useful clustering tool and is made publicly available.

  12. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Darbah, Joseph N.T., E-mail: darbah@ohio.ed [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States); Department of Environmental and Plant Biology, Ohio University, 315 Porter Hall, Athens, OH 45701 (United States); Sharkey, Thomas D. [Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 (United States); Calfapietra, Carlo [Institute of Agro-Environmental and Forest Biology (IBAF), National Research Council (CNR), Via Salaria km 29300, 00016 Monterotondo Scalo, Roma (Italy); Karnosky, David F. [School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 (United States)

    2010-04-15

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO{sub 2} and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO{sub 2} protected photosynthesis of both species against moderate heat stress. Elevated CO{sub 2} increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO{sub 2} treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO{sub 2} were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO{sub 2}. Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO{sub 2} confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  13. Differential response of aspen and birch trees to heat stress under elevated carbon dioxide

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Sharkey, Thomas D.; Calfapietra, Carlo; Karnosky, David F.

    2010-01-01

    The effect of high temperature on photosynthesis of isoprene-emitting (aspen) and non-isoprene-emitting (birch) trees were measured under elevated CO 2 and ambient conditions. Aspen trees tolerated heat better than birch trees and elevated CO 2 protected photosynthesis of both species against moderate heat stress. Elevated CO 2 increased carboxylation capacity, photosynthetic electron transport capacity, and triose phosphate use in both birch and aspen trees. High temperature (36-39 deg. C) decreased all of these parameters in birch regardless of CO 2 treatment, but only photosynthetic electron transport and triose phosphate use at ambient CO 2 were reduced in aspen. Among the two aspen clones tested, 271 showed higher thermotolerance than 42E possibly because of the higher isoprene-emission, especially under elevated CO 2 . Our results indicate that isoprene-emitting trees may have a competitive advantage over non-isoprene emitting ones as temperatures rise, indicating that biological diversity may be affected in some ecosystems because of heat tolerance mechanisms. - We report that elevated CO 2 confers increased thermotolerance on both aspen and birch trees while isoprene production in aspen confers further thermotolerance in aspen.

  14. Algological and Mycological Characterization of Soils under Pine and Birch Forests in the Pasvik Reserve

    Science.gov (United States)

    Korneikova, M. V.; Redkina, V. V.; Shalygina, R. R.

    2018-02-01

    The structure of algological and mycological complexes in Al-Fe-humus podzols (Albic Podzols) under pine and birch forests of the Pasvik Reserve is characterized. The number of micromycetes is higher in more acid soils of the pine forest, while the species diversity is greater under the birch forest. The genus Penicillium includes the largest number of species. The greatest abundance and occurrence frequency are typical for Penicillium spinulosum, P. glabrum, and Trichoderma viride in pine forest and for Umbelopsis isabellina, Mucor sp., Mortierella alpina, P. glabrum, Aspergillus ustus, Trichoderma viride, and T. koningii in birch forest. Cyanobacteria-algal cenoses of the investigated soils are predominated by green algae. Soils under birch forest are distinguished by a greater diversity of algal groups due to the presence of diatoms and xanthophytes. Species of frequent occurrence are represented by Pseudococcomyxa simplex and Parietochloris alveolaris in soils of the pine forest and by Tetracystis cf. aplanospora, Halochlorella rubescens, Pseudococcomyxa simplex, Fottea stichococcoides, Klebsormidium flaccidum, Hantzschia amphioxys, Microcoleus vaginatus, and Aphanocapsa sp. in soils under birch forest

  15. Wood frame systems for wood homes

    Directory of Open Access Journals (Sweden)

    Julio Cesar Molina

    2010-12-01

    Full Text Available The use of constructive systems that combine strength, speed, with competitive differential techniques and mainly, compromising with the environment, is becoming more popular in Brazil. The constructive system in wood frame for houses of up to five stories is very interesting, because it is a light system, structured in reforested treated wood which allows the combination of several materials, besides allowing speed in the construction and total control of the expenses already in the project phase for being industrialized. The structural behavior of the wood frame is superior to the structural masonry in strength, thermal and acoustic comfort. However, in Brazil, the wood frame is still little known and used, due to lack of technical knowledge about the system, prejudice associated the bad use of the wood as construction material, or still, in some cases, lack of normalization. The aim of this manuscript consists of presenting the main technical characteristics and advantages of the constructive system in wood frame homes, approaching the main stages of the constructive process through examples, showing the materials used in the construction, in addition the main international normative recommendations of the project. Thus, this manuscript also hopes to contribute to the popularization of the wood frame system in Brazil, since it is a competitive, fast and ecologically correct system. Moreover, nowadays, an enormous effort of the technical, commercial and industrial section has been accomplished for the development of this system in the country.

  16. Fabrication of Hydrophobic Surface on Wood Veneer via Electroless Nickel Plating Combined with Chemical Corrosion

    Directory of Open Access Journals (Sweden)

    Zhaojun Tang

    2015-12-01

    Full Text Available Birch veneers were coated with Ni-P films by a combined process of KBH4 activation and electroless plating. The plated veneers were further chemically corroded to obtain hydrophobic surfaces on wood. The effect of chemical corrosion on the contact angle of the veneers was investigated. The hydrophobic veneers were characterized by X-ray photo electron spectroscopy (XPS, scanning electron microscopy (SEM, and X-ray diffraction (XRD. The surface contact angle of birch veneer before and after it was plated with Ni-P alloy coating was 41º and 121º, respectively. The contact angle reached 136.7º when the nickel-coated veneers were corroded in CuSO4 aqueous solution for 30 min. XPS analysis showed that Cu0 cluster doped with little CuO formed on the corroded surface of Ni-P alloy film after chemical corrosion. SEM and XRD showed that rough copper clusters formed on the surface of the wood veneer and revealed the reason of the surface hydrophobicity. This study provides a new pathway for fabricating hydrophobic wood.

  17. Potential role of soil calcium in recovery of paper birch following ice storm injury in Vermont, USA

    Science.gov (United States)

    Joshua M. Halman; Paul G. Schaberg; Gary J. Hawley; Christopher F. Hansen

    2011-01-01

    In recent years, an increased number of mature paper birch (Betula papyrifera Marsh.) and heart-leafed paper birch (B. papyrifera var. cordifolia (Regel) Fern.) in northeastern United States forests have exhibited decline symptoms including foliar loss, reduced fine branching, and tree mortality. We assessed crown health, radial...

  18. An investigation of the possible immunological relationship between allergen extracts from birch pollen, hazelnut, potato and apple

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Løwenstein, H

    1978-01-01

    identity between birch pollen and hazelnut. By the same method no partial immunological identity between birch pollen and extracts and fresh peel from apples and potatoes was found. However, both apples and potatoes gave rise to non-immunological affinity precipitates. On this basis it is discussed...

  19. Climate change effect on Betula (birch) and Quercus (oak) pollen seasons in the United States

    Science.gov (United States)

    Zhang, Yong; Bielory, Leonard; Georgopoulos, Panos G.

    2014-07-01

    Climatic change is expected to affect the spatiotemporal patterns of airborne allergenic pollen, which has been found to act synergistically with common air pollutants, such as ozone, to cause allergic airway disease (AAD). Observed airborne pollen data from six stations from 1994 to 2011 at Fargo (North Dakota), College Station (Texas), Omaha (Nebraska), Pleasanton (California), Cherry Hill and Newark (New Jersey) in the US were studied to examine climate change effects on trends of annual mean and peak value of daily concentrations, annual production, season start, and season length of Betula (birch) and Quercus (oak) pollen. The growing degree hour (GDH) model was used to establish a relationship between start/end dates and differential temperature sums using observed hourly temperatures from surrounding meteorology stations. Optimum GDH models were then combined with meteorological information from the Weather Research and Forecasting (WRF) model, and land use land coverage data from the Biogenic Emissions Land use Database, version 3.1 (BELD3.1), to simulate start dates and season lengths of birch and oak pollen for both past and future years across the contiguous US (CONUS). For most of the studied stations, comparison of mean pollen indices between the periods of 1994-2000 and 2001-2011 showed that birch and oak trees were observed to flower 1-2 weeks earlier; annual mean and peak value of daily pollen concentrations tended to increase by 13.6 %-248 %. The observed pollen season lengths varied for birch and for oak across the different monitoring stations. Optimum initial date, base temperature, and threshold GDH for start date was found to be 1 March, 8 °C, and 1,879 h, respectively, for birch; 1 March, 5 °C, and 4,760 h, respectively, for oak. Simulation results indicated that responses of birch and oak pollen seasons to climate change are expected to vary for different regions.

  20. Many Roles of Wood Adhesives

    Science.gov (United States)

    Charles R. Frihart

    2014-01-01

    Although wood bonding is one of the oldest applications of adhesives, going back to early recorded history (1), some aspects of wood bonds are still not fully understood. Most books in the general area of adhesives and adhesion do not cover wood bonding. However, a clearer understanding of wood bonding and wood adhesives can lead to improved products. This is important...

  1. Urban Wood Waste Resource Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wiltsee, G.

    1998-11-20

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

  2. Controversy. The wood war

    International Nuclear Information System (INIS)

    James, O.

    2010-01-01

    The author comments the conflict emerging in France between industries exploiting wood for construction and those exploiting it as a heating material for power generation. The first ones accuse the others to steal their raw material, to pull the prices up, and to destabilize the sector. This conflict takes place notably around sawmill wastes which are used either by wood panel fabricators or by wood pellets producers. Both sectors are claiming they are creating more jobs than the other. The French forest indeed offers good opportunities for both sectors, but other countries which are lacking forest surfaces, are buying wood in France. Several issues are matter of discussion: burning wood seems to go against the reduction of greenhouse gas emissions, subsidies awarded to big heater projects. The situation of the wood sector in Austria, Finland and Poland is briefly presented

  3. The role of novel forest ecosystems in the conservation of wood-inhabiting fungi in boreal broadleaved forests.

    Science.gov (United States)

    Juutilainen, Katja; Mönkkönen, Mikko; Kotiranta, Heikki; Halme, Panu

    2016-10-01

    The increasing human impact on the earth's biosphere is inflicting changes at all spatial scales. As well as deterioration and fragmentation of natural biological systems, these changes also led to other, unprecedented effects and emergence of novel habitats. In boreal zone, intensive forest management has negatively impacted a multitude of deadwood-associated species. This is especially alarming given the important role wood-inhabiting fungi have in the natural decay processes. In the boreal zone, natural broad-leaved-dominated, herb-rich forests are threatened habitats which have high wood-inhabiting fungal species richness. Fungal diversity in other broadleaved forest habitat types is poorly known. Traditional wood pastures and man-made afforested fields are novel habitats that could potentially be important for wood-inhabiting fungi. This study compares species richness and fungal community composition across the aforementioned habitat types, based on data collected for wood-inhabiting fungi occupying all deadwood diameter fractions. Corticioid and polyporoid fungi were surveyed from 67 130 deadwood particles in four natural herb-rich forests, four birch-dominated wood pastures, and four birch-dominated afforested field sites in central Finland. As predicted, natural herb-rich forests were the most species-rich habitat. However, afforested fields also had considerably higher overall species richness than wood pastures. Many rare or rarely collected species were detected in each forest type. Finally, fungal community composition showed some divergence not only among the different habitat types, but also among deadwood diameter fractions. Synthesis and applications : In order to maintain biodiversity at both local and regional scales, conserving threatened natural habitat types and managing traditional landscapes is essential. Man-made secondary woody habitats could provide the necessary resources and serve as surrogate habitats for many broadleaved deadwood

  4. Chapter 9: Wood Energy

    Science.gov (United States)

    Francisco X. Aguilar; Karen Abt; Branko Glavonjic; Eugene Lopatin; Warren  Mabee

    2016-01-01

    The availabilty of information on wood energy continues to improve, particularly for commoditized woodfuels.  Wood energy consumption and production vary in the UNECE region because demand is strngly affected by weather and the prices of competing energy sources.  There has been an increase in wood energy in the power-and-heat sector in the EU28 and North American...

  5. Complex geometries in wood

    DEFF Research Database (Denmark)

    Tamke, Martin; Ramsgaard Thomsen, Mette; Riiber Nielsen, Jacob

    2009-01-01

    The versatility of wood constructions and traditional wood joints for the production of non standard elements was in focus of a design based research. Herein we established a seamless process from digital design to fabrication. A first research phase centered on the development of a robust...... parametric model and a generic design language a later explored the possibilities to construct complex shaped geometries with self registering joints on modern wood crafting machines. The research was carried out as collaboration with industrial partners....

  6. Browsing affects intra-ring carbon allocation in species with contrasting wood anatomy.

    Science.gov (United States)

    Palacio, S; Paterson, E; Sim, A; Hester, A J; Millard, P

    2011-02-01

    Current knowledge on tree carbon (C) allocation to wood is particularly scarce in plants subjected to disturbance factors, such as browsing, which affects forest regeneration worldwide and has an impact on the C balance of trees. Furthermore, quantifying the degree to which tree rings are formed from freshly assimilated vs. stored carbohydrates is highly relevant for our understanding of tree C allocation. We used (13)C labelling to quantify seasonal allocation of stored C to wood formation in two species with contrasting wood anatomy: Betula pubescens Ehrh. (diffuse-porous) and Quercus petraea [Matt.] Liebl. (ring-porous). Clipping treatments (66% shoot removal, and unclipped) were applied to analyse the effect of browsing on C allocation into tree rings, plus the effects on tree growth, architecture, ring width and non-structural carbohydrates (NSCs). The relative contribution of stored C to wood formation was greater in the ring-porous (55-70%) than in the diffuse-porous species (35-60%), although each species followed different seasonal trends. Clipping did not cause a significant depletion of C stores in either species. Nonetheless, a significant increase in the proportion of stored C allocated to earlywood growth was observed in clipped birches, and this could be explained through changes in tree architecture after clipping. The size of C pools across tree species seems to be important in determining the variability of seasonal C allocation patterns to wood and their sensibility to disturbances such as browsing. Our results indicate that the observed changes in C allocation to earlywood in birch were not related to variations in the amount or concentration of NSC stores, but to changes in the seasonal availability of recently assimilated C caused by modifications in tree architecture after browsing.

  7. Integrated production method for wood fuel and pulp wood in Northern Finland; Polttojakeen hankinta puun yhdistelmaekorjuussa ja integroitu energiapuun tuotantomenetelmae Pohjois-Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Hooli, A. [Hooli Oy, Kemi (Finland); Kuitto, P.J. [VTT Energy, Jyvaeskylae (Finland); Ranta, T. [Finntech Ltd. Oy, Jyvaeskylae (Finland)

    1996-12-31

    Chip production company Hooli Ltd. has built an innovative mobile chain-flail delimbing-debarking-unit which includes also a hammer crusher for wood fuel. This integrated production method for wood fuel and pulp wood based on that unit has been planned especially for the circumstances where the power or heating plants are near and the pulp mills more remote from the wood processing sites. The trees are felt into bunches and transported as whole trees or tree-sections to the roadside. The Hooli-unit delimbs and debarks the trees using multi-tree processing. The optimal bark content of Scot pine bolts after processing is under 1 %. All green branches, stops and bark are directly crushed into wood fuel in the same unit. Fuel chips are carried to the nearest power plant. The debarked bolts are transported to the pulpmills in the form of roundwood or pulpchips, thus giving better economy for the whole method. Based on first field experiments in 1995 this method has operated well. However, there are still development work ahead: e.g. good debarking quality of birch and spruce in the winter conditions. To attain the targets of the project looks promising. The project is carried out as joint project between Hooli Ltd, Finntech Ltd. Oy, the Finnish Forest Research Institute, Veitsiluoto Ltd and VTT Energy. The chain-flail delimbing-debarking-crushing unit was built at Tervolan Konepaja Ky

  8. Integrated production method for wood fuel and pulp wood in Northern Finland; Polttojakeen hankinta puun yhdistelmaekorjuussa ja integroitu energiapuun tuotantomenetelmae Pohjois-Suomessa

    Energy Technology Data Exchange (ETDEWEB)

    Hooli, A [Hooli Oy, Kemi (Finland); Kuitto, P J [VTT Energy, Jyvaeskylae (Finland); Ranta, T [Finntech Ltd. Oy, Jyvaeskylae (Finland)

    1997-12-31

    Chip production company Hooli Ltd. has built an innovative mobile chain-flail delimbing-debarking-unit which includes also a hammer crusher for wood fuel. This integrated production method for wood fuel and pulp wood based on that unit has been planned especially for the circumstances where the power or heating plants are near and the pulp mills more remote from the wood processing sites. The trees are felt into bunches and transported as whole trees or tree-sections to the roadside. The Hooli-unit delimbs and debarks the trees using multi-tree processing. The optimal bark content of Scot pine bolts after processing is under 1 %. All green branches, stops and bark are directly crushed into wood fuel in the same unit. Fuel chips are carried to the nearest power plant. The debarked bolts are transported to the pulpmills in the form of roundwood or pulpchips, thus giving better economy for the whole method. Based on first field experiments in 1995 this method has operated well. However, there are still development work ahead: e.g. good debarking quality of birch and spruce in the winter conditions. To attain the targets of the project looks promising. The project is carried out as joint project between Hooli Ltd, Finntech Ltd. Oy, the Finnish Forest Research Institute, Veitsiluoto Ltd and VTT Energy. The chain-flail delimbing-debarking-crushing unit was built at Tervolan Konepaja Ky

  9. Moisture Transport in Wood

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  10. Wood pellet seminar

    International Nuclear Information System (INIS)

    Aarniala, M.; Puhakka, A.

    2001-01-01

    The objective of the wood pellet seminar, arranged by OPET Finland and North Karelia Polytechnic, was to deliver information on wood pellets, pellet burners and boilers, heating systems and building, as well as on the activities of wood energy advisors. The first day of the seminar consisted of presentations of equipment and products, and of advisory desks for builders. The second day of the seminar consisted of presentations held by wood pellet experts. Pellet markets, the economy and production, the development of the pellet markets and their problems (in Austria), the economy of heating of real estates by different fuel alternatives, the production, delivery and marketing of wood pellets, the utilization of wood pellet in different utilization sites, the use of wood pellets in detached houses, pellet burners and fireplaces, and conversion of communal real estate houses to use wood pellets were discussed in the presentations. The presentations held in the third day discussed the utilization of wood pellets in power plants, the regional promotion of the production and the use of pellets. The seminar consisted also of visits to pellet manufacturing plant and two pellet burning heating plants

  11. CHEMICAL VALORIZATION OF AGRICULTURAL BY-PRODUCTS: ISOLATION AND CHARACTERIZATION OF XYLAN-BASED ANTIOXIDANTS FROM ALMOND SHELL BIOMASS

    Directory of Open Access Journals (Sweden)

    Anna Ebringerová

    2008-02-01

    Full Text Available The isolation of non-cellulosic polysaccharides from both almond shells and their solid residue after autohydrolysis using a two-step alkaline extraction without and in combination with short ultrasonic treatment was investigated. The obtained polysaccharide preparations were characterized by yield, chemical composition and structural features, and the antioxidant activity of the water-soluble preparations was discussed in relation to the content of phenolics. The results suggested that, depending on the extraction conditions used, xylan associated to various extent with pectic polysaccharides and phenolics can be prepared, and the reaction time significantly shortened by application of ultrasound. The xylan polymers might serve as biopolymer sources in native form or after targeted modification for production of value-added substances and polysaccharide-based antioxidants, applicable in food, cosmetics and other areas.

  12. Enzymic hydrolysis of xylans. I. A high xylanase and beta-xylosidase producing strain of Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, D.

    1981-01-01

    Aspergillus niger, strain 110.42 (CBS) was selected as a producer of high xylanolytic activities. The time course of xylanase and beta-xylosidase production as well as the effect of pH and temperature on the activity of these enzymes were studied. High-performance liquid chromatography analysis of the enzymic degradation of arabinoxylan showed a nearly complete conversion to pentose sugars. Aspects of using crude xylanase preparations for enzymic saccharification of xylans are discussed.

  13. Estimating the spread rate of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer using fluorescence

    Science.gov (United States)

    Toni Antikainen; Anti Rohumaa; Christopher G. Hunt; Mari Levirinne; Mark Hughes

    2015-01-01

    In plywood production, human operators find it difficult to precisely monitor the spread rate of adhesive in real-time. In this study, macroscopic fluorescence was used to estimate spread rate (SR) of urea formaldehyde adhesive on birch (Betula pendula Roth) veneer. This method could be an option when developing automated real-time SR measurement for...

  14. Photographic guide of selected external defect indicators and associated internal defects in yellow birch

    Science.gov (United States)

    Everette D. Rast; John A. Beaton; David L. Sonderman

    1991-01-01

    To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external...

  15. Growth Response of Seedling Yellow Birch to Humus-Soil Mixtures

    Science.gov (United States)

    Carl H. Tubbs; Robert R. Oberg

    1966-01-01

    Previous observations of the establishment of yellow birch have cited the importance of mixed humus-mineral soil seedbeds. Godman and Krefting pointed out that both germination and growth were enhanced. Subsequent studies have shown that while germination in the absence of competition is adequate on mineral soil of a Podzol A under a wide variety of light and...

  16. Study of the betulin enriched birch bark extracts effects on human carcinoma cells and ear inflammation

    Directory of Open Access Journals (Sweden)

    Dehelean Cristina A

    2012-11-01

    Full Text Available Abstract Background Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition. Results New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%. Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma, A2780 (ovarian carcinoma, HeLa (cervix adenocarcinoma and MCF7 (breast adenocarcinoma, by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice. Conclusions The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.

  17. Delivery Systems for Birch-Bark Triterpenoids and Their Derivatives in Anticancer Research.

    Science.gov (United States)

    Mierina, Inese; Vilskersts, Reinis; Turks, Maris

    2018-05-29

    Birch-bark triterpenoids and their semi-synthetic derivatives possess a wide range of biological activities including cytotoxic effects on various tumour cell lines. However, due to the low solubility and bioavailability, their medicinal applications are rather limited. The use of various nanotechnology-based drug delivery systems is rapidly developing approach to the solubilisation of insufficiently bioavailable pharmaceuticals. Herein, the drug delivery systems deemed to be applicable for birch-bark triterpenoid structures are reviewed. The aforementioned disadvantages of birch-bark triterpenoids and their semi-synthetic derivatives can be overcome through their incorporation into organic nanoparticles, which include various dendrimeric systems, as well as embedding the active compounds into polymer matrices or complexation with carbohydrate nanoparticles without covalent bonding. Some of the known triterpenoid delivery systems consist of nanoparticles featuring inorganic cores covered with carbohydrates or other polymers. Methods for delivering the title compounds through encapsulation and emulsification into lipophilic media are also suitable. Besides, the birch-bark triterpenoids can form self-assembling systems with increased bio-availability. Even more, the self-assembling systems are used as carriers for delivering other chemotherapeutic agents. Another advantage besides increased bioavailability and anticancer activity is the reduced overall systemic toxicity in most of the cases, when triterpenoids are delivered with any of the carriers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. MACC regional multi-model ensemble simulations of birch pollen dispersion in Europe

    NARCIS (Netherlands)

    Sofiev, M.; Berger, U.; Prank, M.; Vira, J.; Arteta, J.; Belmonte, J.; Bergmann, K.C.; Chéroux, F.; Elbern, H.; Friese, E.; Galan, C.; Gehrig, R.; Khvorostyanov, D.; Kranenburg, R.; Kumar, U.; Marécal, V.; Meleux, F.; Menut, L.; Pessi, A.M.; Robertson, L.; Ritenberga, O.; Rodinkova, V.; Saarto, A.; Segers, A.; Severova, E.; Sauliene, I.; Siljamo, P.; Steensen, B.M.; Teinemaa, E.; Thibaudon, M.; Peuch, V.H.

    2015-01-01

    This paper presents the first ensemble modelling experiment in relation to birch pollen in Europe. The seven-model European ensemble of MACC-ENS, tested in trial simulations over the flowering season of 2010, was run through the flowering season of 2013. The simulations have been compared with

  19. Why linear Birch and U/sub s/-U/sub p/ expansions work

    International Nuclear Information System (INIS)

    Grover, R.

    1987-07-01

    The equivalence of the Birch-Murnoghan equation to a linear U/sub s/-U/sub p/ equation was illustrated in the previous paper. Here it is shown in a direct manner how the virial theorem boundary localization of valence electron kinetic energy changes lead to the convergence of the Eulerian strain expansion about the zero-pressure state

  20. Crown Release Increases Diameter Growth and Bole Sprouting of Pole-Size Yellow Birch

    Science.gov (United States)

    Gayne G. Erdmann; Ralph M. Jr. Peterson

    1971-01-01

    During the second and third years after release, dominant, codominant, and intermediate pole-size yellow birch grew nearly twice as fast in diameter as unreleased poles. Growth rates were also related to foliage density. Epicormic sprouting was increased by crown release but most sprouting occured in the second log.

  1. High-Titer Methane from Organosolv-Pretreated Spruce and Birch

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2017-02-01

    Full Text Available The negative impact of fossil fuels and the increased demand for renewable energy sources has led to the use of novel raw material sources. Lignocellulosic biomass could serve as a possible raw material for anaerobic digestion and production of biogas. This work is aimed at using forest biomass, both softwood (spruce and hardwood (birch, as a raw material for anaerobic digestion. We examined the effect of different operational conditions for the organosolv pretreatment (ethanol content, duration of treatment, and addition of acid catalyst on the methane yield. In addition, we investigated the effect of addition of cellulolytic enzymes during the digestion. We found that inclusion of an acid catalyst during organosolv pretreatment improved the yields from spruce, but it did not affect the yields from birch. Shorter duration of treatment was advantageous with both materials. Methane yields from spruce were higher with lower ethanol content whereas higher ethanol content was more beneficial for birch. The highest yields obtained were 185 mL CH4/g VS from spruce and 259.9 mL CH4/g VS from birch. Addition of cellulolytic enzymes improved these yields to 266.6 mL CH4/g VS and 284.2 mL CH4/g VS, respectively.

  2. Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

    Science.gov (United States)

    Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

    2015-09-01

    Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Direct transformation of xylan-type hemicelluloses to furfural via SnCl₄ catalysts in aqueous and biphasic systems.

    Science.gov (United States)

    Wang, Wenju; Ren, Junli; Li, Huiling; Deng, Aojie; Sun, Runcang

    2015-05-01

    Direct catalytic transformation of xylan-type hemicelluloses to furfural in the aqueous system and the biphasic system were comparatively investigated under mild conditions. Screening of several promising chlorides for conversion of beech xylan in the aqueous system revealed the Lewis acid SnCl4 was the most effective catalyst. Comparing to the single aqueous system, the bio-based 2-methyltetrahydrofuran (2-MTHF)/H2O biphasic system was more conducive to the synthesis of furfural, in which the highest furfural yield of 78.1% was achieved by using SnCl4 as catalysts under the optimized reaction conditions (150°C, 120 min). Additionally, the influences of xylan-type hemicelluloses with different chemical and structural features from beech, corncob and bagasse on the furfural production were studied. It was found that furfural yield to some extent was determined by the xylose content in hemicelluloses and also had relationships with the molecular weight of hemicelluloses and the degree of crystallization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Recombinant Mal d 1 facilitates sublingual challenge tests of birch pollen-allergic patients with apple allergy.

    Science.gov (United States)

    Kinaciyan, T; Nagl, B; Faustmann, S; Kopp, S; Wolkersdorfer, M; Bohle, B

    2016-02-01

    It is still unclear whether allergen-specific immunotherapy (AIT) with birch pollen improves birch pollen-related food allergy. One reason for this may be the lack of standardized tests to assess clinical reactions to birch pollen-related foods, for example apple. We tested the applicability of recombinant (r) Mal d 1, the Bet v 1-homolog in apple, for oral challenge tests. Increasing concentrations of rMal d 1 in 0.9% NaCl were sublingually administered to 72 birch pollen-allergic patients with apple allergy. The dose of 1.6 μg induced oral allergy syndromes in 26.4%, 3.2 μg in 15.3%, 6.3 μg in 27.8%, 12.5 μg in 8.3%, 25 μg in 11.1%, and 50 μg in 4.2% of the patients. No severe reactions occurred. None of the patients reacted to 0.9% NaCl alone. Sublingual administration of 50 μg of rMal d 1 induced no reactions in three nonallergic individuals. Our approach allows straight forward, dose-defined sublingual challenge tests in a high number of birch pollen-allergic patients that inter alia can be applied to evaluate the therapeutic efficacy of birch pollen AIT on birch pollen-related food allergy. © 2015 The Authors. Allergy Published by John Wiley & Sons Ltd.

  5. Impacts of Elevated Atmospheric CO2 and O3 on Paper Birch (Betula papyrifera: Reproductive Fitness

    Directory of Open Access Journals (Sweden)

    Joseph N. T. Darbah

    2007-01-01

    Full Text Available Atmospheric CO2 and tropospheric O3 are rising in many regions of the world. Little is known about how these two commonly co-occurring gases will affect reproductive fitness of important forest tree species. Here, we report on the long-term effects of CO3 and O3 for paper birch seedlings exposed for nearly their entire life history at the Aspen FACE (Free Air Carbon Dioxide Enrichment site in Rhinelander, WI. Elevated CO2 increased both male and female flower production, while elevated O3 increased female flower production compared to trees in control rings. Interestingly, very little flowering has yet occurred in combined treatment. Elevated CO2 had significant positive effect on birch catkin size, weight, and germination success rate (elevated CO2 increased germination rate of birch by 110% compared to ambient CO2 concentrations, decreased seedling mortality by 73%, increased seed weight by 17%, increased root length by 59%, and root-to-shoot ratio was significantly decreased, all at 3 weeks after germination, while the opposite was true of elevated O3 (elevated O3 decreased the germination rate of birch by 62%, decreased seed weight by 25%, and increased root length by 15%. Under elevated CO2, plant dry mass increased by 9 and 78% at the end of 3 and 14 weeks, respectively. Also, the root and shoot lengths, as well as the biomass of the seedlings, were increased for seeds produced under elevated CO2, while the reverse was true for seedlings from seeds produced under the elevated O3. Similar trends in treatment differences were observed in seed characteristics, germination, and seedling development for seeds collected in both 2004 and 2005. Our results suggest that elevated CO2 and O3 can dramatically affect flowering, seed production, and seed quality of paper birch, affecting reproductive fitness of this species.

  6. The wood, renewable energy

    International Nuclear Information System (INIS)

    Acket, C.

    2006-12-01

    This document evaluates the french forest situation and its future. Indeed, the wood energy constitutes in France the first renewable energy after the hydraulic. It presents the today situation of the french forest providing statistical data, evaluation of the energy estimation, the carbon fixation, the resources, the perspectives wood energy for 2050, the biofuels and an economic analysis. (A.L.B.)

  7. Heat sterilization of wood

    Science.gov (United States)

    Xiping Wang

    2010-01-01

    Two important questions should be considered in heat sterilizing solid wood materials: First, what temperature–time regime is required to kill a particular pest? Second, how much time is required to heat the center of any wood configuration to the kill temperature? The entomology research on the first question has facilitated the development of international standards...

  8. Wood thermoplastic composites

    Science.gov (United States)

    Daniel F. Caulfield; Craig Clemons; Rodney E. Jacobson; Roger M. Rowell

    2005-01-01

    The term “wood-plastic composites” refers to any number of composites that contain wood (of any form) and either thermoset or thermoplastic polymers. Thermosets or thermoset polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins, such as epoxies and phenolics, plastics with which the forest products industry is most familiar (...

  9. Wood supply and demand

    Science.gov (United States)

    Peter J. Ince; David B. McKeever

    2011-01-01

    At times in history, there have been concerns that demand for wood (timber) would be greater than the ability to supply it, but that concern has recently dissipated. The wood supply and demand situation has changed because of market transitions, economic downturns, and continued forest growth. This article provides a concise overview of this change as it relates to the...

  10. Economy of wood supply

    International Nuclear Information System (INIS)

    Imponen, V.

    1993-01-01

    Research and development of wood fuels production was vigorous in the beginning of the 1980's. Techniques and working methods used in combined harvesting and transportation of energy and merchantable wood were developed in addition to separate energy wood delivery. After a ten year silent period the research on this field was started again. At present the underutilization of forest supplies and the environmental effects of energy production based on fossil fuels caused the rebeginning of the research. One alternative for reduction of the price of wood fuels at the utilization site is the integration of energy and merchantable wood deliveries together. Hence the harvesting and transportation devices can be operated effectively, and the organizational costs are decreased as well. The wood delivery costs consist of the stumpage price, the harvesting and transportation costs, and of general expenses. The stumpage price form the largest cost category (over 50 %) of the industrial merchantable wood delivery, and the harvesting and transportation costs in the case of thinningwood delivery. Forest transportation is the largest part of the delivery costs of logging residues. The general expenses, consisting of the management costs and the interest costs of the capital bound to the storages, form a remarkable cost category in delivery of low-rank wood for energy or conversion purposes. The costs caused by the harvesting of thinningwood, the logging residues, chipping and crushing, the lorry transportation are reviewed in this presentation

  11. How James Wood Works

    Science.gov (United States)

    Goldstein, Evan R., Comp.

    2008-01-01

    Reading through news-media clippings about James Wood, one might reasonably conclude that "pre-eminent critic" is his official job title. In fact, Wood is a staff writer for "The New Yorker" and a professor of the practice of literary criticism at Harvard University. But at a time when there is much hand-wringing about the death of the…

  12. Method of stabilizing wood

    International Nuclear Information System (INIS)

    Pesek, M.; Jarkovsky, J.

    1973-01-01

    Wood is impregnated with a mixture of a vinyl or an allyl monomer (20 - 90 wt. %) and unsaturated polyester resins. The impregnated wood is then exposed to ionizing radiation at doses of 0.1 to 20 Mrad at a temperature of 60 to 180 degC. (B.S.)

  13. Chemical modification of wood

    Science.gov (United States)

    Roger M. Rowell

    2007-01-01

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

  14. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    Sewage sludge and wood ashes could be used as fertilizers in order to increase forest tree production. In southern Sweden forest growth normally increases with approximately 10 % after ash recycling due to increased N and/or P availability. P is added with the ashes and the pH-increasing effect of the wood ash can lead to increased N net mineralization. Other positive effects of wood ash recycling are improved nutrient sustainability and less acid run-off water. Possible negative effects are heavy metal accumulation, if the content of one or more heavy metals of the recycled ash exceeds the heavy metal content of the harvested biomass, and nitrate leaching if the vegetation cannot take up nitrified N. It is important to evaluate the sustainability of fertilization systems based on residues such as sludge and wood ash. Wood ash does not contain N and the P concentration often is too low for the ashes to function as an NP fertilizer. Thus N and sometimes P must be added. Sludge is an interesting alternative. The main purpose of the project is to study sustainable production of forest bio energy in intensively cultivated birch and hybrid aspen stands. Another purpose is to establish experiments that can be used for long term studies and as demonstration objects. In the first few years the goal is to study the short term effects of residue based fertilization compared to conventional NPK fertilization on tree nutrient uptake, nutrient leaching, sustainability and economy. In the long term the goal is to design appropriate fertilization strategies in a residue based fertilization system for the intensive cultivation of birch and hybrid aspen without negative side effects such as large scale nutrient leaching. Four field experiments were established in 2008 and one additional experiment in hybrid aspen will be established in the spring of 2009. Elevated bud N and P concentrations after fertilization with both Ashes+N and NPK means good possibilities for future growth

  15. Altered Expression of Genes Implicated in Xylan Biosynthesis Affects Penetration Resistance against Powdery Mildew.

    Science.gov (United States)

    Chowdhury, Jamil; Lück, Stefanie; Rajaraman, Jeyaraman; Douchkov, Dimitar; Shirley, Neil J; Schwerdt, Julian G; Schweizer, Patrick; Fincher, Geoffrey B; Burton, Rachel A; Little, Alan

    2017-01-01

    Heteroxylan has recently been identified as an important component of papillae, which are formed during powdery mildew infection of barley leaves. Deposition of heteroxylan near the sites of attempted fungal penetration in the epidermal cell wall is believed to enhance the physical resistance to the fungal penetration peg and hence to improve pre-invasion resistance. Several glycosyltransferase (GT) families are implicated in the assembly of heteroxylan in the plant cell wall, and are likely to work together in a multi-enzyme complex. Members of key GT families reported to be involved in heteroxylan biosynthesis are up-regulated in the epidermal layer of barley leaves during powdery mildew infection. Modulation of their expression leads to altered susceptibility levels, suggesting that these genes are important for penetration resistance. The highest level of resistance was achieved when a GT43 gene was co-expressed with a GT47 candidate gene, both of which have been predicted to be involved in xylan backbone biosynthesis. Altering the expression level of several candidate heteroxylan synthesis genes can significantly alter disease susceptibility. This is predicted to occur through changes in the amount and structure of heteroxylan in barley papillae.

  16. Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

    DEFF Research Database (Denmark)

    Assing, K; Bødtger, Uffe; Poulsen, L K

    2007-01-01

    of seasonal allergic symptoms and prospective seasonal symptom registration among subjects with AS. METHODS: On the basis of a population survey, autumn 2002, including skin prick tests (positive if > or =3 mm) and a screening questionnaire, 87 subjects with AS to birch and/or grass pollen, birch and/or grass...... days. RESULTS: Eleven AS subjects (birch: n = 10) subsequently developed allergic symptoms, yet nine admitted, at follow up, to have had symptoms before inclusion, or even denied pollen-related symptoms despite a significant diary. Compared with AS subjects sensitized to grass pollen, AS subjects...

  17. Wood adhesives : vital for producing most wood products

    Science.gov (United States)

    Charles R. Frihart

    2011-01-01

    A main route for the efficient utilization of wood resources is to reduce wood to small pieces and then bond them together (Frihart and Hunt 2010). Although humankind has been bonding wood since early Egyptian civilizations, the quality and quantity of bonded wood products has increased dramatically over the past 100 years with the development of new adhesives and...

  18. 2-methylanthraquinone as a marker of occupational exposure to teak wood dust in boatyards.

    Science.gov (United States)

    Gori, Giampaolo; Carrieri, Mariella; Scapellato, Maria Luisa; Parvoli, Giorgio; Ferrara, Daniela; Rella, Rocco; Sturaro, Alberto; Bartolucci, Giovanni Battista

    2009-01-01

    A new gas chromatographic/mass spectrometric (GC/MS) method was developed to detect 2-methylanthraquinone (2-MeA) in wood dust. 2-MeA is present in teak wood (a suspected human carcinogen) but not in oak, beech, mahogany, birch, ash or pine. The method involved collection of workplace dust on filters and extraction of 2-MeA with methanol and GC/MS analysis. The method was tested on teak wood dust samples (n = 43) collected on polyvinylchloride membrane filters during various work operations in four small factories making furniture and fittings for leisure craft and boatyards (air teak wood dust concentration: range 0.32-14.32 mg m(-3)). A high correlation coefficient for the content of 2-MeA versus teak dust was obtained (logarithmic correlation: y = 1.5308x + 0.0998, r = 0.9215). Determination of airborne 2-MeA is a useful technique to confirm occupational exposure to teak wood dust.

  19. Feasibility of Machine Learning Methods for Separating Wood and Leaf Points from Terrestrial Laser Scanning Data

    Science.gov (United States)

    Wang, D.; Hollaus, M.; Pfeifer, N.

    2017-09-01

    Classification of wood and leaf components of trees is an essential prerequisite for deriving vital tree attributes, such as wood mass, leaf area index (LAI) and woody-to-total area. Laser scanning emerges to be a promising solution for such a request. Intensity based approaches are widely proposed, as different components of a tree can feature discriminatory optical properties at the operating wavelengths of a sensor system. For geometry based methods, machine learning algorithms are often used to separate wood and leaf points, by providing proper training samples. However, it remains unclear how the chosen machine learning classifier and features used would influence classification results. To this purpose, we compare four popular machine learning classifiers, namely Support Vector Machine (SVM), Na¨ıve Bayes (NB), Random Forest (RF), and Gaussian Mixture Model (GMM), for separating wood and leaf points from terrestrial laser scanning (TLS) data. Two trees, an Erytrophleum fordii and a Betula pendula (silver birch) are used to test the impacts from classifier, feature set, and training samples. Our results showed that RF is the best model in terms of accuracy, and local density related features are important. Experimental results confirmed the feasibility of machine learning algorithms for the reliable classification of wood and leaf points. It is also noted that our studies are based on isolated trees. Further tests should be performed on more tree species and data from more complex environments.

  20. FEASIBILITY OF MACHINE LEARNING METHODS FOR SEPARATING WOOD AND LEAF POINTS FROM TERRESTRIAL LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    D. Wang

    2017-09-01

    Full Text Available Classification of wood and leaf components of trees is an essential prerequisite for deriving vital tree attributes, such as wood mass, leaf area index (LAI and woody-to-total area. Laser scanning emerges to be a promising solution for such a request. Intensity based approaches are widely proposed, as different components of a tree can feature discriminatory optical properties at the operating wavelengths of a sensor system. For geometry based methods, machine learning algorithms are often used to separate wood and leaf points, by providing proper training samples. However, it remains unclear how the chosen machine learning classifier and features used would influence classification results. To this purpose, we compare four popular machine learning classifiers, namely Support Vector Machine (SVM, Na¨ıve Bayes (NB, Random Forest (RF, and Gaussian Mixture Model (GMM, for separating wood and leaf points from terrestrial laser scanning (TLS data. Two trees, an Erytrophleum fordii and a Betula pendula (silver birch are used to test the impacts from classifier, feature set, and training samples. Our results showed that RF is the best model in terms of accuracy, and local density related features are important. Experimental results confirmed the feasibility of machine learning algorithms for the reliable classification of wood and leaf points. It is also noted that our studies are based on isolated trees. Further tests should be performed on more tree species and data from more complex environments.

  1. High correlation of specific IgE sensitization between birch pollen, soy and apple allergens indicates pollen-food allergy syndrome among birch pollen allergic patients in northern China.

    Science.gov (United States)

    Hao, Guo-Dong; Zheng, Yi-Wu; Wang, Zhi-Xiang; Kong, Xing-Ai; Song, Zhi-Jing; Lai, Xu-Xin; Spangfort, Michael D

    2016-05-01

    Birch pollen sensitization and associated pollen-food syndrome among Chinese allergic patients have not been investigated. Sera from 203 allergic patients from the northern part of China and collected during February to July 2014 were investigated. Specific immunoglobulin E (IgE) against birch pollen extract Bet v and major birch pollen allergen Bet v 1 were measured using the ADVIA Centaur. The presence of major apple allergen Mal d 1 and soy bean allergen Gly m 4 specific IgE was measured by ImmunoCAP 100. Among the 203 sera, 34 sera (16.7%) had specific IgE to Bet v and of these, 28 sera (82.4%) contained Bet v 1-specific IgE. Among the 28 sera with Bet v 1-specific IgE, 27 sera (96.4%) contained Mal d 1-specific IgE and 22 sera (78.6%) contained Gly m 4-specific IgE. Of the 34 Bet v-positive sera, 6 sera (17.6%) contained no specific IgE for Bet v 1, Mal d 1, or Gly m 4. Almost all Bet v-positive sera were donated during the birch pollen season. The prevalence of birch allergy among patients visiting health care during pollen season can be as high as 16.7% in Tangshan City. The majority of Chinese birch allergic patients are IgE-sensitized to the major birch pollen allergen Bet v 1 as well as to the major apple allergen Mal d 1 and soy bean allergen Gly m 4. A relatively high number of patients (17.6%) are IgE-sensitized to birch pollen allergen(s) other than Bet v 1. The high prevalence of specific IgE to Mal d 1 and Gly m 4 among Bet v 1-sensitized patients indicates that pollen-food allergy syndrome could be of clinical relevance in China.

  2. Cord Wood Testing in a Non-Catalytic Wood Stove

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, G. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-06-30

    EPA Method 28 and the current wood stove regulations have been in-place since 1988. Recently, EPA proposed an update to the existing NSPS for wood stove regulations which includes a plan to transition from the current crib wood fuel to cord wood fuel for certification testing. Cord wood is seen as generally more representative of field conditions while the crib wood is seen as more repeatable. In any change of certification test fuel, there are questions about the impact on measured results and the correlation between tests with the two different fuels. The purpose of the work reported here is to provide data on the performance of a noncatalytic stove with cord wood. The stove selected has previously been certified with crib wood which provides a basis for comparison with cord wood. Overall, particulate emissions were found to be considerably higher with cord wood.

  3. Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

    Science.gov (United States)

    Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

    2017-04-01

    Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for

  4. Effect of changing slope of grain on ash, maple, and yellow birch in bending strength

    Science.gov (United States)

    David E. Kretschmann; James J. Bridwell; Timothy C. Nelson

    2010-01-01

    The presence of slope of grain (SoG) in wood can severely reduce the bending strength in wood. Failure to recognize the degree to which SoG can reduce strength can be catastrophic if wood is in single member use. In the United States, a growing concern in the sport of baseball relates to the high frequency of multi-piece broken wood bats. It was observed that hard...

  5. Hydrogenated graphenes by birch reduction: influence of electron and proton sources on hydrogenation efficiency, magnetism, and electrochemistry

    Czech Academy of Sciences Publication Activity Database

    Eng, A.Y.S.; Sofer, Z.; Huber, Š.; Bouša, D.; Maryško, Miroslav; Pumera, M.

    2015-01-01

    Roč. 21, č. 7 (2015), 16828-16838 ISSN 0947-6539 Institutional support: RVO:68378271 Keywords : hydrogenated graphenes * birch reduction * magnetism * electrochemistry * hydrogenation efficiency Subject RIV: CA - Inorganic Chemistry Impact factor: 5.771, year: 2015

  6. 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...

  7. Fatigue Damage in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1996-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Fatigue failure is found to depend both on the total time under load and on the number of cycles.Recent accelerated fatigue research on wood is reviewed, and a discrepancy between...... to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation between stiffness reduction...

  8. Wood wastes: Uses

    International Nuclear Information System (INIS)

    Cipro, A.

    1993-01-01

    The 1,500 industrial firms manufacturing furniture in the Italian Province of Treviso can generate up to 190,000 tonnes of wood wastes annually. In line with the energy conservation-environmental protection measures contained in Italian Law No. 475/88, this paper indicates convenient uses for these wood wastes - as a raw material for fibreboards or as a fuel to be used in the furniture manufacturing plants themselves and in kilns producing lime. Reference is made to the wood wastes gasification/power generation system being developed by ENEA (the Italian Agency for New Technology, Energy and the Environment)

  9. Consequences of bioenergy wood extraction for landscape-level availability of habitat for dead wood-dependent organisms.

    Science.gov (United States)

    Hiron, Matthew; Jonsell, Mats; Kubart, Ariana; Thor, Göran; Schroeder, Martin; Dahlberg, Anders; Johansson, Victor; Ranius, Thomas

    2017-08-01

    Stumps and slash resulting from forest clearcutting is used as a source of low-net-carbon energy, but there are concerns about the consequences of biofuel extraction on biodiversity. Logging residues constitute potentially important habitats, since a large part of forest biodiversity is dependent on dead wood. Here we used snapshot field data from a managed forest landscape (25 000 ha) to predict landscape scale population changes of dead wood dependent organisms after extraction of stumps and slash after clearcutting. We did this by estimating habitat availability for all observed dead wood-dependent beetles, macrofungi, and lichens (380 species) in the whole landscape. We found that 53% of species occurred in slash or stumps. For most species, population declines after moderate extraction (≤30%) were small (dead wood types. However, some species were only recorded in slash and stumps. Red listed species were affected by slash and stump extraction (12 species), but less often than other species. Beetles and fungi were more affected by stump extraction, while lichens were more affected by slash extraction. For beetles and lichens, extraction of a combination of spruce, pine and birch resulted in larger negative effects than if only extracting spruce, while for fungi tree species had little effect. We conclude that extensive extraction decreases the amount of habitat to such extent that it may have negative consequences on species persistence at the landscape level. The negative consequences can be limited by extracting only slash, or only logging residues from spruce stands. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2014-01-01

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

  11. Xylan degradation by the human gut Bacteroides xylanisolvens XB1A(T) involves two distinct gene clusters that are linked at the transcriptional level.

    Science.gov (United States)

    Despres, Jordane; Forano, Evelyne; Lepercq, Pascale; Comtet-Marre, Sophie; Jubelin, Gregory; Chambon, Christophe; Yeoman, Carl J; Berg Miller, Margaret E; Fields, Christopher J; Martens, Eric; Terrapon, Nicolas; Henrissat, Bernard; White, Bryan A; Mosoni, Pascale

    2016-05-04

    Plant cell wall (PCW) polysaccharides and especially xylans constitute an important part of human diet. Xylans are not degraded by human digestive enzymes in the upper digestive tract and therefore reach the colon where they are subjected to extensive degradation by some members of the symbiotic microbiota. Xylanolytic bacteria are the first degraders of these complex polysaccharides and they release breakdown products that can have beneficial effects on human health. In order to understand better how these bacteria metabolize xylans in the colon, this study was undertaken to investigate xylan breakdown by the prominent human gut symbiont Bacteroides xylanisolvens XB1A(T). Transcriptomic analyses of B. xylanisolvens XB1A(T) grown on insoluble oat-spelt xylan (OSX) at mid- and late-log phases highlighted genes in a polysaccharide utilization locus (PUL), hereafter called PUL 43, and genes in a fragmentary remnant of another PUL, hereafter referred to as rPUL 70, which were highly overexpressed on OSX relative to glucose. Proteomic analyses supported the up-regulation of several genes belonging to PUL 43 and showed the important over-production of a CBM4-containing GH10 endo-xylanase. We also show that PUL 43 is organized in two operons and that the knockout of the PUL 43 sensor/regulator HTCS gene blocked the growth of the mutant on insoluble OSX and soluble wheat arabinoxylan (WAX). The mutation not only repressed gene expression in the PUL 43 operons but also repressed gene expression in rPUL 70. This study shows that xylan degradation by B. xylanisolvens XB1A(T) is orchestrated by one PUL and one PUL remnant that are linked at the transcriptional level. Coupled to studies on other xylanolytic Bacteroides species, our data emphasize the importance of one peculiar CBM4-containing GH10 endo-xylanase in xylan breakdown and that this modular enzyme may be used as a functional marker of xylan degradation in the human gut. Our results also suggest that B. xylanisolvens

  12. Preparation of Polyvinyl Alcohol/Xylan Blending Films with 1,2,3,4-Butane Tetracarboxylic Acid as a New Plasticizer

    Directory of Open Access Journals (Sweden)

    Cun-dian Gao

    2014-01-01

    Full Text Available Miscible, biodegradable polyvinyl alcohol (PVA/xylan blending films were firstly prepared in the range of the PVA/xylan weight ratio from 1 : 2 to 3 : 1 by casting method using 1,2,3,4-butane tetracarboxylic acid (BTCA as a new plasticizer. The properties of blending films as functions of PVA/xylan weight ratio and BTCA amount were discussed. XRD and FT-IR were applied to characterize the blending films. Experimental results indicated that tensile strength (TS and elongation at break (EAB of blending films decreased along with the decrease of the PVA/xylan weight ratio. Both of TS and EAB firstly increased and then decreased as the amount of BTCA was increased. More importantly, blending films were biodegraded almost by 41% with an addition of 10% BTCA in blending films within 30 days in soil. For all hydroxyl functionalized polymers (xylan and PVA, their molecular interactions and miscibility with BTCA endowed blending films with the biocompatibility and biodegradability. Therefore, these blending films are environmentally friendly materials which could be applied as biodegradable plastics for food packaging and agricultural applications.

  13. Cadmium accumulation and its effect on the in vitro growth of woody fleabane and mycorrhized white birch

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, R.; Bertrand, A.; Casares, A. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain); Garcia, R. [Departamento de Quimica Fisica y Analitica, Oviedo University, Julian Claveria s/n, 33071 Oviedo (Spain); Gonzalez, A. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain)], E-mail: aidag@uniovi.es; Tames, R.S. [Departamento de Biologia de Organismos y Sistemas, Oviedo University, Catedratico Rodrigo Uria s/n, 33071 Oviedo (Spain)

    2008-04-15

    The effect of Cd on woody fleabane (Dittrichia viscosa (L.) Greuter) and white birch (Betula celtiberica Rothm. and Vasc.) was examined. Woody fleabane and white birch were grown in vitro in Murashige, T., Skoog, F., [1962. A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15, 473-479] (MS) plus Cd (10 mg Cd kg{sup -1}) and except for root length in white birch, plant development was inhibited when Cd was added. Cd accumulation in above-ground tissues showed differences among clones, reaching 1300 and 463 mg Cd kg{sup -1} dry wt. in selected clones of woody fleabane and white birch, respectively. Tolerance of Paxillus filamentosus (Scop) Fr. to Cd was also examined before mycorrhization. Plants of mycorrhized white birch grown in the presence of Cd had a better development and accumulated more Cd in their shoots than the non-mycorrhized ones. The use of selected clones of woody fleabane and the mycorrhization of white birch enhance extraction efficiency from contaminated soils in phytoremediation programs. - The high accumulation of Cd observed in selected clones of Dittrichia viscosa and mycorrhized Betula celtiberica grown in vitro implies a potential application for phytoextraction.

  14. Proteomic Analysis of Responsive Proteins Induced in Japanese Birch Plantlet Treated with Salicylic Acid

    Directory of Open Access Journals (Sweden)

    Hiromu Suzuki

    2014-07-01

    Full Text Available The present study was performed to unravel the mechanisms of systemic acquired resistance (SAR establishment and resistance signaling pathways against the canker-rot fungus (Inonotus obliquus strain IO-U1 infection in Japanese birch plantlet No.8. Modulation of protein-profile induced by salicylic acid (SA-administration was analyzed, and SA-responsive proteins were identified. In total, 5 specifically expressed, 3 significantly increased, and 3 significantly decreased protein spots were identified using liquid chromatography/tandem mass spectrometry (LC/MS/MS and the sequence tag method. These proteins were malate dehydrogenase, succinate dehydrogenase, phosphoglycerate kinase, diaminopimalate decarboxylase, arginase, chorismate mutase, cyclophilin, aminopeptidase, and unknown function proteins. These proteins are considered to be involved in SAR-establishment mechanisms in the Japanese birch plantlet No 8.

  15. Growth and Yield of 15-Year Plantations of Pine, Spruce and Birch in Agricultural Land

    Directory of Open Access Journals (Sweden)

    Daugaviete Mudrite

    2017-07-01

    Full Text Available The growth data and the potential returns from 15-year-old plantations of pine Pinus sylvestris L. (6 trial sites, spruce Picea abies Karst L. (9 trial sites and silver birch Betula pendula Roth (13 trial sites, established in abandoned agricultural lands in a variety of soil types (sod calcareous, anthrosols, podzolic, podzols, gley, podzolic gley, alluvial, using the planting density 2,500 and 3,300 and also 5,000 trees/ha are analysed.

  16. Shelf life extension and sensory evaluation of birch tree sap using chemical preservatives

    Directory of Open Access Journals (Sweden)

    Maciej Bilek

    2016-10-01

    Full Text Available The aim of this study was to assess the stability of the birch tree sap, depending on the addition and concentration of two chemical factors, ie. potassium sorbate and acids: malic, citric or lactic. As in our previous studies we found that the optimal physical parameter to assess the stability of birch sap is turbidity measurement, we used turbidimeter for estimate the effectiveness of shelf life extending. Sensory evaluation was carried out by university sensory panel with 8 skilled people (students and teachers with pre-selection and basic training of sensory methodology. On the other hand artificial perception measurements were realized by electronic nose. Birch tree sap stability without addition of preservatives, both room temperature and refrigerated, is less than three days. The effectiveness of preservation of birch tree sap depends on the concentration of acids. Independently of storage temperature, samples that received stability during the whole one-month storage period, were those with potassium sorbate and three acids in the highest concentrations, ie. malic acid at 0.3%, citric acid at 0.5% and lactic acid at 0.5%. Unfortunately, concentrations of acids, which allow extension of shelf life at least for one month in a room temperature, are characterized by the worst sensory evaluation rating. Thus, they should be corrected by the use of additives for improving the flavor, such as fruit syrups or herbal extracts. On the other hand, additionally storage in a refrigerated conditions allows one-month-stability for the sample with the highest sensory evaluation rating, ie. with the addition of lactic acid at 0.1% and potassium sorbate, which taste not need to be corrected.

  17. Why linear Birch and U/sub s/-U/sub p/ expansions work

    International Nuclear Information System (INIS)

    Grover, R.

    1987-11-01

    The equivalence of the Birch-Murnaghan equation to a linear U/sub s/-U/sub p/ equation was illustrated in the previous paper. Here we show in a direct manner how the virial theorem and the effect of core exclusion on valence electron kinetic energy changes lead to the convergence of the Eulerian strain expansion about the zero-pressure state. 7 refs., 4 tabs

  18. Indirectional statistics and the significance of an asymmetry discovered by Birch

    International Nuclear Information System (INIS)

    Kendall, D.G.; Young, G.A.

    1984-01-01

    Birch (1982, Nature, 298, 451) reported an apparent 'statistical asymmetry of the Universe'. The authors here develop 'indirectional analysis' as a technique for investigating statistical effects of this kind and conclude that the reported effect (whatever may be its origin) is strongly supported by the observations. The estimated pole of the asymmetry is at RA 13h 30m, Dec. -37deg. The angular error in its estimation is unlikely to exceed 20-30deg. (author)

  19. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2009-11-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission potential in 2006 was almost 2600 ng gdw−1 h−1 (3.5 pmol gdw−1 s−1 while in 2007 α-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last for several years.

  20. Differential bacterial capture and transport preferences facilitate co-growth on dietary xylan in the human gut

    DEFF Research Database (Denmark)

    Leth, Maria Louise; Ejby, Morten; Workman, Christopher

    2018-01-01

    Metabolism of dietary glycans is pivotal in shaping the human gut microbiota. However, the mechanisms that promote competition for glycans among gut commensals remain unclear. Roseburia intestinalis, an abundant butyrate-producing Firmicute, is a key degrader of the major dietary fibre xylan...... of capture and transport preferences as a possible strategy to facilitate co-growth on abundant dietary fibres and may offer a unique route to manipulate the microbiota based on glycan transport preferences in therapeutic interventions to boost distinct taxa....

  1. Reported symptoms to peanut between 4 and 8 years among children sensitized to peanut and birch pollen - results from the BAMSE birth cohort.

    Science.gov (United States)

    Asarnoj, A; Ostblom, E; Ahlstedt, S; Hedlin, G; Lilja, G; van Hage, M; Wickman, M

    2010-02-01

    Specific IgE tests are sometimes difficult to interpret due to structural similarities between certain food and pollen allergens. This may be the reason why concomitant sensitization to peanut and birch pollen is frequently seen. The aim of this study was to investigate reported symptoms to peanut- and birch pollen in relation to sensitization. The data originate from 1928 children in the BAMSE birth cohort. Background factors and clinical parameters were obtained and the levels of IgE antibodies to peanut and birch pollen measured at 4 and 8 years. IgE antibodies to peanut were found in 5.5% and 7.4% of the children at 4 and 8 years, respectively. The IgE antibody levels to peanut were higher in children sensitized to peanut but not birch than in children sensitized to peanut and birch among both 4- and 8-year-olds (P = 0.093 and P = 0.003, respectively). Eight-year-olds sensitized to peanut but not birch, more often reported symptoms to peanut than children sensitized to both peanut and birch pollen (76%vs 46%, P = 0.002). The probability of reported symptoms to peanut increased significantly with increasing IgE levels to peanut, especially in 8-year-olds not sensitized to birch. Children sensitized to both peanut and birch pollen are less likely to report symptoms to peanut than children sensitized to peanut but not to birch pollen at 8 years. This is likely due to cross reactions between birch pollen and peanut and can explain the high sensitization rate to peanut in areas where birch trees are common.

  2. Extração e caracterização de xilanas de sabugos de milho Extraction and characterization of xylans from corncobs

    Directory of Open Access Journals (Sweden)

    Simone S. Silva

    1998-06-01

    Full Text Available Neste trabalho, duas frações de xilana, denominadas xilana A e xilana B, foram isoladas a partir de sabugos de milho através de três processos diferentes, combinando métodos de extração aquosa, remoção de lipídeos, deslignificação e extração alcalina. Os produtos obtidos durante os processos foram analisados por termogravimetria. A etapa de deslignificação foi responsável por uma acentuada degradação dos polímeros, evidenciada por queda de rendimento e resistência térmica. Os espectros obtidos no infravermelho evidenciaram a ausência de ácidos urônicos na cadeia polimérica. As viscosidades intrínsecas obtidas para a xilana A (56 mL/g e xilana B (75 mL/g associadas aos resultados do infravermelho sugerem um número maior de grupos substituintes, constituídos basicamente por resíduos de L-arabinose, para a xilana B.In this work, two fractions of xylan, named xylan A and xylan B, were isolated from corncobs through three different processes using aqueous extraction, lipid removal, delignification, and alkaline extraction. The products obtained during the processes were analysed by thermogravimetry. The delignification step was responsible for the occurrence of an accentuated polymer degradation, evidenced by yield and thermal resistance decrease. Infrared spectra indicated the absence of uronic acids in the polymeric chains. Intrinsic viscosities obtained for xylan A (56 mL/g and xylan B (75 mL/g, associated to the results from i.r. analysis, suggested a higher number of substituents, basically constituted of L-arabinose residues, in the case of xylan B.

  3. Wood for the trees

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2013-10-01

    Full Text Available Our paper focuses on the materiality, cultural history and cultural relations of selected artworks in the exhibition Wood for the trees (Lismore Regional Gallery, New South Wales, Australia, 10 June – 17 July 2011. The title of the exhibition, intentionally misreading the aphorism “Can’t see the wood for the trees”, by reading the wood for the resource rather than the collective wood[s], implies conservation, preservation, and the need for sustaining the originating resource. These ideas have particular resonance on the NSW far north coast, a region once rich in rainforest. While the Indigenous population had sustainable practices of forest and land management, the colonists deployed felling and harvesting in order to convert the value of the local, abundant rainforest trees into high-value timber. By the late twentieth century, however, a new wave of settlers launched a protest movements against the proposed logging of remnant rainforest at Terania Creek and elsewhere in the region. Wood for the trees, curated by Gallery Director Brett Adlington, plays on this dynamic relationship between wood, trees and people. We discuss the way selected artworks give expression to the themes or concepts of productive labour, nature and culture, conservation and sustainability, and memory. The artworks include Watjinbuy Marrawilil’s (1980 Carved ancestral figure ceremonial pole, Elizabeth Stops’ (2009/10 Explorations into colonisation, Hossein Valamanesh’s (2008 Memory stick, and AñA Wojak’s (2008 Unread book (in a forgotten language. Our art writing on the works, a practice informed by Bal (2002, Muecke (2008 and Papastergiadis (2004, becomes a conversation between the works and the themes or concepts. As a form of material excess of the most productive kind (Grosz, 2008, p. 7, art seeds a response to that which is in the air waiting to be said of the past, present and future.

  4. Wood fuel and the environment

    International Nuclear Information System (INIS)

    Foster, C.A.

    1992-01-01

    The purpose of this paper is to try and demonstrate the role that the use of Wood as a Fuel can play in our environment. The term ''Wood Fuel'', for the purposes of these proceedings, refers to the use of wood obtained from the forest or the farm. It does not refer to waste wood from for example buildings. The role of wood fuel in the environment can be assessed at many different levels. In this paper three different scales of ''Environment'' and the role of wood fuel in each, will be considered. These three scales are namely the global environment, the local environment, and the National (community) environment. (Author)

  5. Crystal Structure and Substrate Specificity Modification of Acetyl Xylan Esterase from Aspergillus luchuensis.

    Science.gov (United States)

    Komiya, Dai; Hori, Akane; Ishida, Takuya; Igarashi, Kiyohiko; Samejima, Masahiro; Koseki, Takuya; Fushinobu, Shinya

    2017-10-15

    Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis ( Al AXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. Al AXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that Al AXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of A lAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with site-directed mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan. IMPORTANCE Hemicelluloses in the plant cell wall are often decorated by acetyl and ferulic acid groups. Therefore, complete and efficient degradation of plant polysaccharides requires the enzymes for cleaving the side chains of the polymer. Since the Esterase_phb family contains a wide array of fungal FAEs and AXEs from fungi and bacteria, our study will provide a structural basis for the molecular mechanism of these industrially relevant enzymes in biopolymer degradation. The structure of the Esterase_phb family also provides information for bacterial polyhydroxyalkanoate depolymerases that are involved in biodegradation of

  6. Multi-scale processes of beech wood disintegration and pretreatment with 1-ethyl-3-methylimidazolium acetate/water mixtures.

    Science.gov (United States)

    Viell, Jörn; Inouye, Hideyo; Szekely, Noemi K; Frielinghaus, Henrich; Marks, Caroline; Wang, Yumei; Anders, Nico; Spiess, Antje C; Makowski, Lee

    2016-01-01

    The valorization of biomass for chemicals and fuels requires efficient pretreatment. One effective strategy involves the pretreatment with ionic liquids which enables enzymatic saccharification of wood within a few hours under mild conditions. This pretreatment strategy is, however, limited by water and the ionic liquids are rather expensive. The scarce understanding of the involved effects, however, challenges the design of alternative pretreatment concepts. This work investigates the multi length-scale effects of pretreatment of wood in 1-ethyl-3-methylimidazolium acetate (EMIMAc) in mixtures with water using spectroscopy, X-ray and neutron scattering. The structure of beech wood is disintegrated in EMIMAc/water mixtures with a water content up to 8.6 wt%. Above 10.7 wt%, the pretreated wood is not disintegrated, but still much better digested enzymatically compared to native wood. In both regimes, component analysis of the solid after pretreatment shows an extraction of few percent of lignin and hemicellulose. In concentrated EMIMAc, xylan is extracted more efficiently and lignin is defunctionalized. Corresponding to the disintegration at macroscopic scale, SANS and XRD show isotropy and a loss of crystallinity in the pretreated wood, but without distinct reflections of type II cellulose. Hence, the microfibril assembly is decrystallized into rather amorphous cellulose within the cell wall. The molecular and structural changes elucidate the processes of wood pretreatment in EMIMAc/water mixtures. In the aqueous regime with >10.7 wt% water in EMIMAc, xyloglucan and lignin moieties are extracted, which leads to coalescence of fibrillary cellulose structures. Dilute EMIMAc/water mixtures thus resemble established aqueous pretreatment concepts. In concentrated EMIMAc, the swelling due to decrystallinization of cellulose, dissolution of cross-linking xylan, and defunctionalization of lignin releases the mechanical stress to result in macroscopic disintegration of

  7. Wood plastic combination

    International Nuclear Information System (INIS)

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

    1976-03-01

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

  8. Bacteroides intestinalis DSM 17393, a member of the human colonic microbiome, upregulates multiple endoxylanases during growth on xylan.

    Science.gov (United States)

    Wang, Kui; Pereira, Gabriel V; Cavalcante, Janaina J V; Zhang, Meiling; Mackie, Roderick; Cann, Isaac

    2016-09-29

    Many human diets contain arabinoxylan, and the ease of genome sequencing coupled with reduced cost have led to unraveling the arsenal of genes utilized by the colonic Bacteroidetes to depolymerize this polysaccharide. The colonic Bacteroidetes with potential to ferment arabinoxylans include Bacteroides intestinalis. In this study, we analyzed the hydrolytic activities of members of a xylan degradation cluster encoded on the genome of Bacteroides intestinalis DSM 17393. Here, it is demonstrated that a cocktail of the xylanolytic enzymes completely hydrolyze arabinoxylans found in human diets. We show that this bacterium and relatives have evolved and secrete a unique bifunctional endoxylanase/arabinofuranosidase in the same polypeptide. The bifunctional enzyme and other secreted enzymes attack the polysaccharides extracellularly to remove the side-chains, exposing the xylan backbone for cleavage to xylo-oligosaccharides and xylose. These end products are transported into the cell where a β-xylosidase cleaves the oligosaccharides to fermentable sugars. While our experiments focused on B. intestinalis, it is likely that the extracellular enzymes also release nutrients to members of the colonic microbial community that practice cross-feeding. The presence of the genes characterized in this study in other colonic Bacteroidetes suggests a conserved strategy for energy acquisition from arabinoxylan, a component of human diets.

  9. Carbon Nanotubes Reinforced Maleic Anhydride-Modified Xylan-g-Poly(N-isopropylacrylamide) Hydrogel with Multifunctional Properties

    Science.gov (United States)

    Liu, Xinxin; Song, Tao; Chang, Minmin; Meng, Ling; Wang, Xiaohui; Sun, Runcang; Ren, Junli

    2018-01-01

    Introducing multifunctional groups and inorganic material imparts xylan-based hydrogels with excellent properties, such as responsiveness to pH, temperature, light, and external magnetic field. In this work, a composite hydrogel was synthesized by introducing acid treated carbon nanotubes (AT-CNTs) into the maleic anhydride modified xylan grafted with poly(N-isopropylacrylamide) (MAX-g-PNIPAM) hydrogels network. It was found that the addition of AT-CNTs affected the MAX-g-PNIPAM hydrogel structure, the swelling ratio and mechanical properties, and imparted the hydrogel with new properties of electrical conductivity and near infrared region (NIR) photothermal conversion. AT-CNTs could reinforce the mechanical properties of MAX-g-PNIPAM hydrogels, being up to 83 kPa for the compressive strength when the amount was 11 wt %, which was eight times than that of PNIPAM hydrogel and four times than that of MAX-g-PNIPAM hydrogel. The electroconductibility was enhanced by the increase of AT-CNTs amounts. Meanwhile, the composite hydrogel also exhibited multiple shape memory and NIR photothermal conversion properties, and water temperature was increased from 26 °C to 56 °C within 8 min under the NIR irradiation. Thus, the AT-CNTs reinforced MAX-g-PNIPAM hydrogel possessed promising multifunctional properties, which offered many potential applications in the fields of biosensors, thermal-arrest technology, and drug-controlled release. PMID:29495611

  10. An Aspergillus oryzae acetyl xylan esterase: molecular cloning and characteristics of recombinant enzyme expressed in Pichia pastoris.

    Science.gov (United States)

    Koseki, Takuya; Miwa, Yozo; Akao, Takeshi; Akita, Osamu; Hashizume, Katsumi

    2006-02-10

    We screened 20,000 clones of an expressed sequence tag (EST) library from Aspergillus oryzae (http://www.nrib.go.jp/ken/EST/db/index.html) and obtained one cDNA clone encoding a protein with similarity to fungal acetyl xylan esterase. We also cloned the corresponding gene, designated as Aoaxe, from the genomic DNA. The deduced amino acid sequence consisted of a putative signal peptide of 31-amino acids and a mature protein of 276-amino acids. We engineered Aoaxe for heterologous expression in P. pastoris. Recombinant AoAXE (rAoAXE) was secreted by the aid of fused alpha-factor secretion signal peptide and accumulated as an active enzyme in the culture medium to a final level of 190 mg/l after 5 days. Purified rAoAXEA before and after treatment with endoglycosidase H migrated by SDS-PAGE with a molecular mass of 31 and 30 kDa, respectively. Purified rAoAXE displayed the greatest hydrolytic activity toward alpha-naphthylacetate (C2), lower activity toward alpha-naphthylpropionate (C3) and no detectable activity toward acyl-chain substrates containing four or more carbon atoms. The recombinant enzyme catalyzed the release of acetic acid from birchwood xylan. No activity was detectable using methyl esters of ferulic, caffeic or sinapic acids. rAoAXE was thermolabile in comparison to other AXEs from Aspergillus.

  11. Nutritional ecology of the formosan subterranean termite (Isoptera: Rhinotermitidae): feeding response to commercial wood species.

    Science.gov (United States)

    Morales-Ramos, J A; Rojas, M G

    2001-04-01

    The feeding preferences of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were tested in three separate experiments on 28 different wood species. Experiment 1 was a multiple-choice test designed to test relative preferences among 24 wood species commercially available in New Orleans, LA. Experiment 2 was a similar study designed to test relative preferences among 21 wood species shown or reported to be unpalatable to the Formosan subterranean termite. Experiment 3 was a no-choice test to examine the feeding deterrence of the 10 least preferred wood species. Preference was determined by consumption rates. Birch (Betula alleghaniensis Britton), red gum (Liquidambar styraciflua L.), Parana pine [Araucaria angustifolia (Bert.) 1, sugar maple (Acer saccharum Marsh.), pecan (Carya illinoensis Wangenh.), and northern red oak (Quercus rubra L.) were the most preferred species by C. formosanus in order of consumption rate. All of these species were significantly more preferred than southern yellow pine (Pinus taeda L.), widely used for monitoring. Sinker cypress [ = old growth bald cypress, Taxodium distichum (L.)], western red cedar (Thuja plicata Donn), Alaskan yellow cedar (Chamaecyparis nootkatensis D. Don), eastern red cedar (Juniperus virginiana L.), sassafras [Sassafras albidum (Nutt.)], Spanish cedar (Cedrella odorata L.), Honduras mahogany (Swietenia macrophyla King), Indian rosewood (Dalbergia latifolia Roxb.), Honduras rosewood (D. stevensonii Standl.), and morado (Machaerium sp.) induced significant feeding deterrence and mortality to C. formosanus. The last eight species produced 100% mortality after 3 mo.

  12. Turning wood residues into wood revenues

    International Nuclear Information System (INIS)

    Graham, R.G.; Kravetz, Don

    1996-01-01

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

  13. Energy from wood - an overview

    International Nuclear Information System (INIS)

    Nussbaumer, T.

    2000-01-01

    The present publication is the introduction to a series of papers on fundamentals and applications of wood energy. It summarizes figures and data of the actual situation of fuel wood utilization in Switzerland and its potential for the future. Further, the advantages of bio-energy are discussed and the possibilities of funding for bio-energy in Switzerland are described. Wood contributes with 2.5% to the total energy demand in Switzerland nowadays. However, the utilization of wood energy can be more than doubled, which is one of the targets of the Swiss energy policy. The supply chains for the different types of fuel wood are described and specifications and prices of log wood, forestry wood chips and wood residues are presented. The main applications of wood energy are residential heating with manually operated wood boilers and stoves, on the one hand, and heat production with automatic wood furnaces in industry and communities, on the other hand. Automatic furnaces have been promoted in the past ten years and hence they contribute nowadays with more than 50% to the energy supply from wood with a further growing share. As an assistance for further information, a list of institutions and addresses in the field of wood energy in Switzerland is given in the paper. (author)

  14. Biobutanol production by Clostridium acetobutylicum using xylose recovered from birch Kraft black liquor.

    Science.gov (United States)

    Kudahettige-Nilsson, Rasika L; Helmerius, Jonas; Nilsson, Robert T; Sjöblom, Magnus; Hodge, David B; Rova, Ulrika

    2015-01-01

    Acetone-butanol-ethanol (ABE) fermentation was studied using acid-hydrolyzed xylan recovered from hardwood Kraft black liquor by CO2 acidification as the only carbon source. Detoxification of hydrolyzate using activated carbon was conducted to evaluate the impact of inhibitor removal and fermentation. Xylose hydrolysis yields as high as 18.4% were demonstrated at the highest severity hydrolysis condition. Detoxification using active carbon was effective for removal of both phenolics (76-81%) and HMF (38-52%). Batch fermentation of the hydrolyzate and semi-defined P2 media resulted in a total solvent yield of 0.12-0.13g/g and 0.34g/g, corresponding to a butanol concentration of 1.8-2.1g/L and 7.3g/L respectively. This work is the first study of a process for the production of a biologically-derived biofuel from hemicelluloses solubilized during Kraft pulping and demonstrates the feasibility of utilizing xylan recovered directly from industrial Kraft pulping liquors as a feedstock for biological production of biofuels such as butanol. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Abdulkadir Malkoçoğlu

    2006-04-01

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

  16. Wood for fuel

    Energy Technology Data Exchange (ETDEWEB)

    Beaton, D

    1986-01-01

    Growing wood for energy could contribute three million tonnes of coal equivalent per year by the end of the century. Research programmes in the UK involved with energy forestry are reported. Three systems of wood energy, modified conventional forestry, single stem timber cropping and short rotation coppicing are being investigated. The short rotation coppicing requires inputs similar to those of agricultural crops and the machinery geared towards agricultural operations is compatible with it. Single stem forestry has a medium rotation period of 20 years. The production of coppice wood fuels is discussed in further detail for different parts of the UK with recommendations for species selection and adaption of existing farming practices. A coppice willow harvester has been developed for harvesting during November - February. Weed control and fertilizer application are also briefly mentioned.

  17. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

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

    Science.gov (United States)

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

    2015-12-01

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

  19. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S

    2005-07-15

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  20. Methane from wood

    International Nuclear Information System (INIS)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S.

    2005-07-01

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  1. Wood energy-commercial applications

    Science.gov (United States)

    Kennel, R. P.

    1978-01-01

    Wood energy is being widely investigated in many areas of the country because of the many obvious benefits of wood fuel such as the low price per million Btus relative to coal, oil, and gas; the wide availability of noncommercial wood and the proven ability to harvest it; established technology which is reliable and free of pollution; renewable resources; better conservation for harvested land; and the potential for jobs creation. The Southeastern United States has a specific leadership role in wood energy based on its established forest products industry experience and the potential application of wood energy to other industries and institutions. Significant questions about the widespread usage of wood energy are being answered in demonstrations around the country as well as the Southeast in areas of wood storage and bulk handling; high capitalization costs for harvesting and combustion equipment; long term supply and demand contracts; and the economic feasibility of wood energy outside the forest products industry.

  2. 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.

  3. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  4. Rhizosphere C flux from tree roots to soil: spatial and temporal differences between sugar maple and yellow birch saplings

    Science.gov (United States)

    Phillips, R. P.; Fahey, T. J.

    2003-12-01

    Rhizosphere carbon flux (RCF) has rarely been measured for intact root-soil systems. We measured RCF for eight year-old saplings of sugar maple (Acer saccharum) and yellow birch (Betula allegheniensis) collected from Hubbard Brook Experimental Forest and transplanted into 35 cm diameter pots with native soil horizons intact. We hypothesized birch roots which support ectomycorrhizal fungi would release more C to the rhizosphere than sugar maple roots which support vesicular-arbuscular mycorrhizal fungi. Saplings (n=5) were pulse-labeled with 13CO2 at ambient CO2 concentrations for 4-6 hours, and the label was chased through rhizosphere and bulk soil pools in organic and mineral horizons for 7 days. We observed immediate appearance of the label in rhizosphere soil, and there was a striking difference in the temporal pattern of 13C concentration between species. In maple, peak concentration of the label appeared at day 1 and declined over time whereas in birch the label increased in concentration over the 7 day chase period. As a result, total RCF was 2-3 times greater from birch roots. We estimate at least 5% and 10% of NPP may be released from this flux pathway in sugar maple and yellow birch saplings respectively. These results suggest that rhizosphere C flux likely represents a substantial proportion of NPP in northern hardwood forests, and may be influenced by trees species and mycorrhizal association.

  5. Power generation from waste wood

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, H

    1980-04-18

    Since the energy crisis, power generation from waste wood has become increasingly important. The most profitable way to use waste wood in woodworking plants with an annual production of 100 to 150,000 m/sup 3/ solid measure of wood chips and bark is by combustion and thermal energy recovery. In plants with an annual production of 10,000 m/sup 3/ solid measure of wood chips and bark, electric power generation is a suitable application.

  6. Structure and function of wood

    Science.gov (United States)

    Alex Wiedenhoeft

    2010-01-01

    Wood is a complex biological structure, a composite of many chemistries and cell types acting together to serve the needs of a living plant. Attempting to understand wood in the context of wood technology, we have often overlooked the key and basic fact that wood evolved over the course of millions of years to serve three main functions in plants― conduction of water...

  7. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    The intent of this article is to demonstrate how wood waste called sawdust or wood flour can be transformed by plastic moulding machine into items of economic value. Wood flour is wood reduced to very fine particle form. It can be waste product from saw mills, wood working plants or produced from selected dry wood by ...

  8. Status of wood energy applications

    International Nuclear Information System (INIS)

    Zerbe, J.I.

    1991-01-01

    In this address, the potential of wood and wood residues to supply future energy needs is examined. In addition, the possible environmental impact of the use of wood fuels on global climate change is discussed. Technologies for the development of new fuels are described

  9. Strength loss in decayed wood

    Science.gov (United States)

    Rebecca E. Ibach; Patricia K. Lebow

    2014-01-01

    Wood is a durable engineering material when used in an appropriate manner, but it is susceptible to biological decay when a log, sawn product, or final product is not stored, handled, or designed properly. Even before the biological decay of wood becomes visually apparent, the decay can cause the wood to become structurally unsound. The progression of decay to that...

  10. Macrophotographic wood atlas of Annonaceae.

    NARCIS (Netherlands)

    Koek-Noorman, J.; Westra, L.I.T.

    2012-01-01

    In this article, a general description of the microscopic wood anatomy of Annonaceae is given. We provide a description of the wood anatomical features of the family and of all subfamilies and tribes, all from material in the Utrecht Wood collection. Hand-lens images can be an important help in

  11. Wood construction and magnetic characteristics of impregnated type magnetic wood

    International Nuclear Information System (INIS)

    Oka, Hideo; Hojo, Atsushi; Seki, Kyoushiro; Takashiba, Toshio

    2002-01-01

    The results of experiments involving the AC and DC magnetic characteristics of impregnated type magnetic wood were studied by taking into consideration the wood construction and fiber direction. The experimental results show that the sufficient amount of impregnated magnetic fluid varies depending on the fiber direction and length, and the grain face of the wood material. The impregnated type magnetic wood sample that is fully impregnated by magnetic fluid has a 60% saturation magnetization compared to the saturation magnetization of magnetic fluid. Samples for which the wood fiber direction was the same as the direction of the magnetic path had a higher magnetization intensity and permeability

  12. CO2 response to rewetting of hydrophobic soils - Can soil water repellency inhibit the 'Birch effect'?

    Science.gov (United States)

    Sanchez-Garcia, Carmen; Urbanek, Emilia; Doerr, Stefan

    2017-04-01

    Rewetting of dry soils is known to cause a short-term CO2 pulse commonly known as the 'Birch effect'. The displacement of CO2 with water during the process of wetting has been recognised as one of the sources of this pulse. The 'Birch effect' has been extensively observed in many soils, but some studies report a lack of such phenomenon, suggesting soil water repellency (SWR) as a potential cause. Water infiltration in water repellent soils can be severely restricted, causing overland flow or increased preferential flow, resulting in only a small proportion of soil pores being filled with water and therefore small gas-water replacement during wetting. Despite the suggestions of a different response of CO2 fluxes to wetting under hydrophobic conditions, this theory has never been tested. The aim of this study is to test the hypothesis that CO2 pulse does not occur during rewetting of water repellent soils. Dry homogeneous soils at water-repellent and wettable status have been rewetted with different amounts of water. CO2 flux as a response to wetting has been continuously measured with the CO2 flux analyser. Delays in infiltration and non-uniform heterogeneous water flow were observed in water repellent soils, causing an altered response in the CO2 pulse in comparison to typically observed 'Birch effect' in wettable systems. The main conclusion from the study is that water repellency not only affects water relations in soil, but has also an impact on greenhouse gas production and transport and therefore should be included as an important parameter during the sites monitoring and modelling of gas fluxes.

  13. DNA typing of birch: Development of a forensic STR system for Betula pendula and Betula pubescens.

    Science.gov (United States)

    Wesselink, Monique; Dragutinović, Aleksandar; Noordhoek, Jeroen W; Bergwerff, Leonie; Kuiper, Irene

    2018-04-07

    Although botanical trace evidence is often encountered in case investigations, the utilization of such traces in forensic investigations is still limited. Development of a forensic STR system for the two species of Betula (birch) indigenous to and abundant in North West Europe is a step in enhancing the applicability of traces from these species. We describe six microsatellite markers developed for birch species in detail, including repeat structure, and we propose a nomenclature for the encountered alleles. To assess the population characteristics, the genetic composition of wild, planted and intermediate populations of Betula pendula (a diploid species) and Betula pubescens (a tetraploid species) were investigated. The genetic differences between these two species were larger than the differences between populations of one species, even when both species co-occurred at one location. Therefore allele frequencies were estimated for both species separately. General, conservative random match probabilities were estimated for wild trees based on these allele frequencies (5∙10 -6 for the diploid B. pendula and 1∙10 -13 for the tetraploid B. pubescens), illustrating the potential relevance if trace evidence secured from a suspect is found to match a birch tree growing on or near a crime scene. Apart from wild trees, planted Betula trees also occur that may not originate from seeds, but may have been propagated through cloning. Based on the studied Betula trees, the random match probability of a potentially planted profile might be as high as 1.4∙10 -2 . Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Comprehensive Transcriptome Analysis of Response to Nickel Stress in White Birch (Betula papyrifera.

    Directory of Open Access Journals (Sweden)

    Gabriel Theriault

    Full Text Available White birch (Betula papyrifera is a dominant tree species of the Boreal Forest. Recent studies have shown that it is fairly resistant to heavy metal contamination, specifically to nickel. Knowledge of regulation of genes associated with metal resistance in higher plants is very sketchy. Availability and annotation of the dwarf birch (B. nana enables the use of high throughout sequencing approaches to understanding responses to environmental challenges in other Betula species such as B. papyrifera. The main objectives of this study are to 1 develop and characterize the B. papyrifera transcriptome, 2 assess gene expression dynamics of B. papyrifera in response to nickel stress, and 3 describe gene function based on ontology. Nickel resistant and susceptible genotypes were selected and used for transcriptome analysis. A total of 208,058 trinity genes were identified and were assembled to 275,545 total trinity transcripts. The transcripts were mapped to protein sequences and based on best match; we annotated the B. papyrifera genes and assigned gene ontology. In total, 215,700 transcripts were annotated and were compared to the published B. nana genome. Overall, a genomic match for 61% transcripts with the reference genome was found. Expression profiles were generated and 62,587 genes were found to be significantly differentially expressed among the nickel resistant, susceptible, and untreated libraries. The main nickel resistance mechanism in B. papyrifera is a downregulation of genes associated with translation (in ribosome, binding, and transporter activities. Five candidate genes associated to nickel resistance were identified. They include Glutathione S-transferase, thioredoxin family protein, putative transmembrane protein and two Nramp transporters. These genes could be useful for genetic engineering of birch trees.

  15. Thermal analysis of wood of the main tree species of Central Siberia

    Directory of Open Access Journals (Sweden)

    S. R. Loskutov

    2015-12-01

    Full Text Available Thermal decomposition of wood from coniferous and deciduous species of Siberia has been studied using thermogravimetry (TG and differential scanning calorimetry (DSC. The tree species were larch Larix sibirica Ledeb., Scots pine Pinus sylvestris L., spruce Picea obovata Ledeb., fir Abies sibirica Ledeb., Siberian pine Pinus sibirica Du Tour., birch Betula pendula Roth., and aspen Populus tremula L. Thermal analysis of wood samples was carried out under oxidative (air and inert (argon atmospheres from 25 to 700 °С at heating rates 10, 20, 40 °С • min–1 (TG/DTG and from 25 to 590 °С at heating rates 10, 40 °С • min–1 (DSC. The stages of thermal decomposition, the temperature intervals, the mass loss, the mass loss rate, the temperature of DTG/DSC peaks, and heating effects were determined for each tree species. The kinetic thermal degradation parameters of wood were obtained by the Broido and Ozawa–Flynn–Wall models. The wood of coniferous and deciduous species of Siberia was characterized on the base of analysis of activation energy values at various stages of thermal decomposition and the relations of activation energy on conversion level of wood substance of different tree species, and also the comparison of mass loss at the same stages of thermal destruction, heating effects, residual mass and other parameters of TG/DTG, DSC. In our opinion, the results of this work present interest for researchers and specialists in the field of forest pyrology, wood science, dendrochemistry.

  16. Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

    Science.gov (United States)

    2011-01-01

    Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX) and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy. PMID:21702938

  17. Comparative Analysis of End Point Enzymatic Digests of Arabino-Xylan Isolated from Switchgrass (Panicum virgatum L of Varying Maturities using LC-MSn

    Directory of Open Access Journals (Sweden)

    Michael J. Bowman

    2012-11-01

    Full Text Available Switchgrass (Panicum virgatum L., SG is a perennial grass presently used for forage and being developed as a bioenergy crop for conversion of cell wall carbohydrates to biofuels. Up to 50% of the cell wall associated carbohydrates are xylan. SG was analyzed for xylan structural features at variable harvest maturities. Xylan from each of three maturities was isolated using classical alkaline extraction to yield fractions (Xyl A and B with varying compositional ratios. The Xyl B fraction was observed to decrease with plant age. Xylan samples were subsequently prepared for structure analysis by digesting with pure endo-xylanase, which preserved side-groups, or a commercial carbohydrase preparation favored for biomass conversion work. Enzymatic digestion products were successfully permethylated and analyzed by reverse-phase liquid chromatography with mass spectrometric detection (RP-HPLC-MSn. This method is advantageous compared to prior work on plant biomass because it avoids isolation of individual arabinoxylan oligomers. The use of RP-HPLC- MSn differentiated 14 structural oligosaccharides (d.p. 3–9 from the monocomponent enzyme digestion and nine oligosaccharide structures (d.p. 3–9 from hydrolysis with a cellulase enzyme cocktail. The distribution of arabinoxylan oligomers varied depending upon the enzyme(s applied but did not vary with harvest maturity.

  18. Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

    Directory of Open Access Journals (Sweden)

    Qing Qing

    2011-06-01

    Full Text Available Abstract Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy.

  19. Insight into Aluminum Sulfate-Catalyzed Xylan Conversion into Furfural in a γ-Valerolactone/Water Biphasic Solvent under Microwave Conditions.

    Science.gov (United States)

    Yang, Tao; Zhou, Yi-Han; Zhu, Sheng-Zhen; Pan, Hui; Huang, Yao-Bing

    2017-10-23

    A simple and efficient biphasic system with an earth-abundant metal salt catalyst was used to produce furfural from xylan with a high yield of up to 87.8 % under microwave conditions. Strikingly, the metal salt Al 2 (SO 4 ) 3 exhibited excellent catalytic activity for xylan conversion, owing to a combination of Lewis and Brønsted acidity and its ability to promote good phase separation. The critical role of the SO 4 2- anion was first analyzed, which resulted in the aforementioned characteristics when combined with the Al 3+ cation. The mixed solvent system with γ-valerolactone (GVL) as the organic phase provided the highest furfural yield, resulting from its good dielectric properties and dissolving capacity, which facilitated the absorption of microwave energy and promoted mass transfer. Mechanistic studies suggested that the xylan-to-furfural conversion proceeded mainly through a hydrolysis-isomerization-dehydration pathway and the hexa-coordinated Lewis acidic [Al(OH) 2 (aq)] + species were the active sites for xylose-xylulose isomerization. Detailed kinetic studies of the subreaction for the xylan conversion revealed that GVL regulates the reaction rates and pathways by promoting the rates of the key steps involved for furfural production and suppressing the side reactions for humin production. Finally, the Al 2 (SO 4 ) 3 catalyst was used for the production of furfural from several lignocellulosic feedstocks, revealing its great potential for other biomass conversions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Tannins in tropical woods

    Energy Technology Data Exchange (ETDEWEB)

    Doat, J

    1978-01-01

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

  1. Grant Wood: "American Gothic."

    Science.gov (United States)

    Fitzgerald, Diane M.

    1988-01-01

    Presents a lesson plan which exposes students in grades 10-12 to the visual symbols and historical references contained in Grant Wood's "American Gothic." Includes background information on the artist and the painting, instructional strategies, a studio activity, and evaluation criteria. (GEA)

  2. Dark Dark Wood

    DEFF Research Database (Denmark)

    2017-01-01

    2017 student Bachelor film. Synopsis: Young princess Maria has had about enough of her royal life – it’s all lesson, responsibilities and duties on top of each other, every hour of every day. Overwhelmed Maria is swept away on an adventure into the monster-filled dark, dark woods. During 2017...

  3. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O; Ribeiro, R [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1998-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  4. Sweetgum - an American wood

    Science.gov (United States)

    C. B. Briscoe

    1973-01-01

    Sweetgum grows throughout most of the eastern United States and sporadically throughout Mexico and Central America. The wood is moderately heavy, even-textured, and it machines moderately well. It is used for a variety of purposes, with furniture, plywood, containers, and pulp absorbing the most volume. Growth is good, but supplies are slowly diminishing because the...

  5. Wood waste in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Matos, O.; Ribeiro, R. [Biomass Centre for Energy - CBE, Miranda do Corvo (Portugal)

    1997-12-31

    The energy policy of the EC, as well as most of member states points to a sizeable increase of energy production based on renewable energy sources, wood, wood residues, agricultural residues, energy crops including SRF, organic sludges, solid residues, etc. Most recent goals indicate a desirable duplication of today`s percentage by 2010. The reasons for this interest, besides diversification of sources, less dependence on imported fuels, use of endogenous resources, expected decrease of fossil fuel reserves, use of available land, additional employment and income for rural communities, etc., are related to important environmental benefits namely in terms of emissions of hot house gases. Wood waste, resulting from forest operations, cleaning, cultural and final cuttings, and from wood based industries, constitute a special important resource by reason of quality and availability. In addition to this they do not require additional land use and the removal is beneficial. In the run-up to the becoming December`s 1997 `Climate Change Summit` in Kioto, there is mounting pressure on companies to plan on carbon cuts. (author) 6 refs., 1 tab.

  6. Handling wood shavings

    Energy Technology Data Exchange (ETDEWEB)

    1974-09-18

    Details of bulk handling equipment suitable for collection and compressing wood waste from commercial joinery works are discussed. The Redler Bin Discharger ensures free flow of chips from storage silo discharge prior to compression into briquettes for use as fuel or processing into chipboard.

  7. Chemical composition and speciation of particulate organic matter from modern residential small-scale wood combustion appliances.

    Science.gov (United States)

    Czech, Hendryk; Miersch, Toni; Orasche, Jürgen; Abbaszade, Gülcin; Sippula, Olli; Tissari, Jarkko; Michalke, Bernhard; Schnelle-Kreis, Jürgen; Streibel, Thorsten; Jokiniemi, Jorma; Zimmermann, Ralf

    2018-01-15

    Combustion technologies of small-scale wood combustion appliances are continuously developed decrease emissions of various pollutants and increase energy conversion. One strategy to reduce emissions is the implementation of air staging technology in secondary air supply, which became an established technique for modern wood combustion appliances. On that account, emissions from a modern masonry heater fuelled with three types of common logwood (beech, birch and spruce) and a modern pellet boiler fuelled with commercial softwood pellets were investigated, which refer to representative combustion appliances in northern Europe In particular, emphasis was put on the organic constituents of PM2.5, including polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and phenolic species, by targeted and non-targeted mass spectrometric analysis techniques. Compared to conventional wood stoves and pellet boilers, organic emissions from the modern appliances were reduced by at least one order of magnitude, but to a different extent for single species. Hence, characteristic ratios of emission constituents and emission profiles for wood combustion identification and speciation do not hold for this type of advanced combustion technology. Additionally, an overall substantial reduction of typical wood combustion markers, such as phenolic species and anhydrous sugars, were observed. Finally, it was found that slow ignition of log woods changes the distribution of characteristic resin acids and phytosterols as well as their thermal alteration products, which are used as markers for specific wood types. Our results should be considered for wood combustion identification in positive matrix factorisation or chemical mass balance in northern Europe. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Influence of mycorrhizal associations on paper birch and jack pine seedlings when exposed to elevated copper, nickel or aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Jones, M.D.; Browning, M.H.R.; Hutchinson, T.C.

    1986-10-01

    Acid deposition may adversely affect northern forest ecosystems by increasing the concentration of metals in the soil solution. This study investigates the effects of ectomycorrhizal fungi on paper birch and jack pine seedlings exposed to elevated Cu, Ni or Al in sand culture. One of four mycorrhizal fungi, Scleroderma flavidum, was able to reduce Ni toxicity to the birch seedlings. It did this by reducing transport of Ni to the stems. None of the fungi affected Cu toxicity in birch. In separate experiments, jack pine seedlings were exposed to combinations of Al and Ca. Infection with Rhizopogon rubescens increased seedling susceptibility to Al. Seedlings inoculated with Suillus tomentosus showed a greater growth stimulation by Ca than uninoculated jack pines. Thus, for both tree species, the mycorrhizal association could alter the response of seedlings to high concentrations of certain metals, although this varied with fungal species. 8 references.

  9. Improvement of the quality of wood derived biofuel-oils; Puuperaeisten biopolttooeljyjen laadun parantaminen. Raakasuovan terminen nestefaasikaesittely hiilivety-polttoaineiksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A; McKeough, P; Kuoppala, E; Kylloenen, H; Levander, J; Tapola, E; Haekkinen, R

    1996-12-31

    Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralized refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Both catalytic hydrotreatment and liquid-phase thermal treatment of a mixed pine/birch soap have been investigated in the laboratory. Liquid and gaseous hydrocarbons were the principal products formed in both types of treatment. Although the liquid product formed under hydrotreatment conditions contained a higher proportion of aliphatic compounds, it was clear that the thermal treatment process would be, economically, the more favorable option. In the thermal process, a predominantly hydrocarbon oil product was obtained at 450 deg C using a residence time of at least 60 min. About 50 % of the energy content of the tall oil soap was recovered as oil product, about 30 % as gases, and about 20 % as organic material contained in an aqueous slurry phase. When the oil product was carefully separated from the aqueous slurry phase, only trace amounts of impurities, such as water, sodium and organic acid salts were present in the product. A techno-economic evaluation of the process concept has been performed. The economics of the thermal treatment process appear to be favorable in comparison with those of the conventional acidulation process

  10. Improvement of the quality of wood derived biofuel-oils; Puuperaeisten biopolttooeljyjen laadun parantaminen. Raakasuovan terminen nestefaasikaesittely hiilivety-polttoaineiksi

    Energy Technology Data Exchange (ETDEWEB)

    Oasmaa, A.; McKeough, P.; Kuoppala, E.; Kylloenen, H.; Levander, J.; Tapola, E.; Haekkinen, R.

    1995-12-31

    Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralized refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock. Both catalytic hydrotreatment and liquid-phase thermal treatment of a mixed pine/birch soap have been investigated in the laboratory. Liquid and gaseous hydrocarbons were the principal products formed in both types of treatment. Although the liquid product formed under hydrotreatment conditions contained a higher proportion of aliphatic compounds, it was clear that the thermal treatment process would be, economically, the more favorable option. In the thermal process, a predominantly hydrocarbon oil product was obtained at 450 deg C using a residence time of at least 60 min. About 50 % of the energy content of the tall oil soap was recovered as oil product, about 30 % as gases, and about 20 % as organic material contained in an aqueous slurry phase. When the oil product was carefully separated from the aqueous slurry phase, only trace amounts of impurities, such as water, sodium and organic acid salts were present in the product. A techno-economic evaluation of the process concept has been performed. The economics of the thermal treatment process appear to be favorable in comparison with those of the conventional acidulation process

  11. The safety and efficacy of subcutaneous birch pollen immunotherapy - a one-year, randomised, double-blind, placebo-controlled study

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Poulsen, L K; Jacobi, H H

    2002-01-01

    BACKGROUND: There is only very limited documentation of the efficacy and safety of high-dose subcutaneous birch pollen immunotherapy (IT) in double-blind, placebo-controlled (DBPC) studies. Birch pollen is a major cause of allergic morbidity in northern Europe and in eastern parts of North Americ...

  12. Cooking birch pollen-related food: divergent consequences for IgE- and T cell-mediated reactivity in vitro and in vivo

    NARCIS (Netherlands)

    Bohle, Barbara; Zwölfer, Bettina; Heratizadeh, Annice; Jahn-Schmid, Beatrice; Antonia, Yuliya Dall; Alter, Mareike; Keller, Walter; Zuidmeer, Laurian; van Ree, Ronald; Werfel, Thomas; Ebner, Christof

    2006-01-01

    BACKGROUND: The major birch pollen allergen Bet v 1 cross-reacts with homologous food allergens, resulting in IgE-mediated oral allergy syndromes (OASs). To avoid this food, allergy allergologists and guidebooks advise patients to consume birch pollen-related foods after heating. OBJECTIVE: We

  13. Mimotopes for Api g 5, a Relevant Cross-reactive Allergen, in the Celery-Mugwort-Birch-Spice Syndrome.

    Science.gov (United States)

    Lukschal, Anna; Wallmann, Julia; Bublin, Merima; Hofstetter, Gerlinde; Mothes-Luksch, Nadine; Breiteneder, Heimo; Pali-Schöll, Isabella; Jensen-Jarolim, Erika

    2016-03-01

    In the celery-mugwort-birch-spice syndrome, a significant proportion of IgE is directed against high molecular weight (HMW) glycoproteins, including the celery allergen Api g 5. BIP3, a monoclonal antibody originally raised against birch pollen, recognizes HMW allergens in birch and mugwort pollens, celery, and Apiaceae spices. Our aim was to generate mimotopes using BIP3 for immunization against the HMW allergens relevant in the celery-mugwort-birch-spice cross reactivity syndrome. Mimotopes were selected from a random-peptide display library by BIP3 and applied in IgE inhibition assays. The 3 phage clones with the highest inhibitory capacity were chosen for immunization of BALB/c mice. Mouse immune sera were tested for IgG binding to blotted birch pollen extract and used for inhibiting patients' IgE binding. Furthermore, sera were tested for binding to Api g 5, to horseradish peroxidase (HRP) as a second glycoprotein, or to non-glycosylated control allergen Phl p 5 in ELISA, and the specific Api g 5-specific IgG titers were determined. Three rounds of biopanning resulted in phage clones exhibiting 7 different sequences including 1 dominant, 1-6-cyclo-CHKLRCDKAIA. Three phage clones had the capacity to inhibit human IgE binding and induced IgG to the HMW antigen when used for immunizing BALB/c mice. The induced BIP3-mimotope IgG reached titers of 1:500 specifically to Api g 5, but hardly reacted to glycoprotein HRP, revealing a minor role of carbohydrates in their epitope. The mimotopes characterized in this study mimic the epitope of BIP3 relevant for Api g 5, one of the cross-reactive HMW allergens relevant in the celery-mugwort-birch-spice syndrome. BIP3 mimotopes may be used in the future for hyposensitization in this clinical syndrome by virtue of good and specific immunogenicity.

  14. Wood construction under cold climate

    DEFF Research Database (Denmark)

    Wang, Xiaodong; Hagman, Olle; Sundqvist, Bror

    2014-01-01

    As wood constructions increasingly use engineered wood products worldwide, concerns arise about the integrity of the wood and adhesives system. The glueline stability is a crucial issue for engineered wood application, especially under cold climate. In this study, Norway spruce (Picea abies...... affected shear strength of wood joints. As temperature decreased, the shear strength decreased. PUR resin resulted in the strongest shear strength at all temperatures tested. MF resin responded to temperature changes in a similar ways as the PUR resin. The shear strength of wood joints with EPI resins...... specimens need to be tested in further work to more completely present the issue. The EN 301 and EN 302 may need to be specified based on wood species....

  15. Partial structural characterization and antioxidant activity of a phenolic-xylan from Castanea sativa hardwood.

    Science.gov (United States)

    Renault, Emmanuel; Barbat-Rogeon, Aline; Chaleix, Vincent; Calliste, Claude-Alain; Colas, Cyril; Gloaguen, Vincent

    2014-09-01

    4-O-Methylglucuronoxylans (MGX) were isolated from chestnut wood sawdust using two different procedures: chlorite delignification followed by the classical alkaline extraction step, and an unusual green chemistry process of delignification using phthalocyanine/H2O2 followed by a simple extraction with hot water. Antioxidant properties of both MGX were evaluated against the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) by electronic spin resonance (ESR). IC50 of water-extracted MGX was found to be less than 225 μg mL(-1), in contrast with alkali-extracted MGX for which no radical scavenging was observed. Characterization of extracts by colorimetric assay, GC, LC-MS and NMR spectroscopy provided some clues to understanding structure-function relationships of MGX in connection with their antioxidant activity. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A Transcriptomic Analysis of Xylan Mutants Does Not Support the Existence of a Secondary Cell Wall Integrity System in Arabidopsis.

    Science.gov (United States)

    Faria-Blanc, Nuno; Mortimer, Jenny C; Dupree, Paul

    2018-01-01

    Yeast have long been known to possess a cell wall integrity (CWI) system, and recently an analogous system has been described for the primary walls of plants (PCWI) that leads to changes in plant growth and cell wall composition. A similar system has been proposed to exist for secondary cell walls (SCWI). However, there is little data to support this. Here, we analyzed the stem transcriptome of a set of cell wall biosynthetic mutants in order to investigate whether cell wall damage, in this case caused by aberrant xylan synthesis, activates a signaling cascade or changes in cell wall synthesis gene expression. Our data revealed remarkably few changes to the transcriptome. We hypothesize that this is because cells undergoing secondary cell wall thickening have entered a committed programme leading to cell death, and therefore a SCWI system would have limited impact. The absence of transcriptomic responses to secondary cell wall alterations may facilitate engineering of the secondary cell wall of plants.

  17. Xylan utilization in human gut commensal bacteria is orchestrated by unique modular organization of polysaccharide-degrading enzymes.

    Science.gov (United States)

    Zhang, Meiling; Chekan, Jonathan R; Dodd, Dylan; Hong, Pei-Ying; Radlinski, Lauren; Revindran, Vanessa; Nair, Satish K; Mackie, Roderick I; Cann, Isaac

    2014-09-02

    Enzymes that degrade dietary and host-derived glycans represent the most abundant functional activities encoded by genes unique to the human gut microbiome. However, the biochemical activities of a vast majority of the glycan-degrading enzymes are poorly understood. Here, we use transcriptome sequencing to understand the diversity of genes expressed by the human gut bacteria Bacteroides intestinalis and Bacteroides ovatus grown in monoculture with the abundant dietary polysaccharide xylan. The most highly induced carbohydrate active genes encode a unique glycoside hydrolase (GH) family 10 endoxylanase (BiXyn10A or BACINT_04215 and BACOVA_04390) that is highly conserved in the Bacteroidetes xylan utilization system. The BiXyn10A modular architecture consists of a GH10 catalytic module disrupted by a 250 amino acid sequence of unknown function. Biochemical analysis of BiXyn10A demonstrated that such insertion sequences encode a new family of carbohydrate-binding modules (CBMs) that binds to xylose-configured oligosaccharide/polysaccharide ligands, the substrate of the BiXyn10A enzymatic activity. The crystal structures of CBM1 from BiXyn10A (1.8 Å), a cocomplex of BiXyn10A CBM1 with xylohexaose (1.14 Å), and the CBM from its homolog in the Prevotella bryantii B14 Xyn10C (1.68 Å) reveal an unanticipated mode for ligand binding. A minimal enzyme mix, composed of the gene products of four of the most highly up-regulated genes during growth on wheat arabinoxylan, depolymerizes the polysaccharide into its component sugars. The combined biochemical and biophysical studies presented here provide a framework for understanding fiber metabolism by an important group within the commensal bacterial population known to influence human health.

  18. Xylan utilization in human gut commensal bacteria is orchestrated by unique modular organization of polysaccharide-degrading enzymes

    KAUST Repository

    Zhang, Meiling

    2014-08-18

    Enzymes that degrade dietary and host-derived glycans represent the most abundant functional activities encoded by genes unique to the human gut microbiome. However, the biochemical activities of a vast majority of the glycan-degrading enzymes are poorly understood. Here, we use transcriptome sequencing to understand the diversity of genes expressed by the human gut bacteria Bacteroides intestinalis and Bacteroides ovatus grown in monoculture with the abundant dietary polysaccharide xylan. The most highly induced carbohydrate active genes encode a unique glycoside hydrolase (GH) family 10 endoxylanase (BiXyn10A or BACINT-04215 and BACOVA-04390) that is highly conserved in the Bacteroidetes xylan utilization system. The BiXyn10A modular architecture consists of a GH10 catalytic module disrupted by a 250 amino acid sequence of unknown function. Biochemical analysis of BiXyn10A demonstrated that such insertion sequences encode a new family of carbohydrate-binding modules (CBMs) that binds to xy-lose- configured oligosaccharide/polysaccharide ligands, the substrate of the BiXyn10A enzymatic activity. The crystal structures of CBM1 from BiXyn10A (1.8 Å), a cocomplex of BiXyn10A CBM1 with xylohexaose (1.14 Å), and the CBM fromits homolog in the Prevotella bryantii B 14 Xyn10C (1.68 Å) reveal an unanticipated mode for ligand binding. Aminimal enzyme mix, composed of the gene products of four of the most highly up-regulated genes during growth on wheat arabinoxylan, depolymerizes the polysaccharide into its component sugars. The combined biochemical and biophysical studies presented here provide a framework for understanding fiber metabolism by an important group within the commensal bacterial population known to influence human health.

  19. Prospect for Developing a Consolidated Bioprocessing (CBP) Strain Using Xylan as the Substrate: the Case Study of Yarrowia lipolytica

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Wei, Hui; Alahuhta, Markus; Zhang, Min; Himmel, Michael E.

    2016-07-08

    To achieve the goal of developing a direct microbial sugar conversion platform for the production of lipids and drop-in fuels from cellulosic biomass substrate, Yarrowia lipolytica was used to investigate its potential for being developed as CBP strain by expressing cellulase and xylanase enzymes. Y. lipolytica is known to accumulate lipids intracellularly and is capable of metabolizing glucose and xylose to produce lipids; however, due to the lack of the biomass degrading enzymes, it cannot directly utilize lignocellulosic substrates as carbon sources. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of several xylanases in Y. lipolytica. To the best of our knowledge, this is the first study introducing heterologous hemicellulose genes into the genome of Y. lipolytica. SDS-PAGE and western blotting analysis showed that the endo-xylanase gene XynII and exo-xylosidase gene XlnD were successfully expressed and secreted, and the expressed xylanases were likely either not or sparsely glycosylated, which is advantageous for expression of heterologous proteins from any species. Enzymatic activity tests further demonstrated active expression of XynII and XlnD in Y. lipolytica. Furthermore, synergistic action on converting xylan to xylose was observed when XlnD worked in concert with XynII. XlnD was able to work on the xylo-oligomers generated by XynII, enhancing the xylan conversion to monomeric xylose. The successful expression of these xylanases in Yarrowia further advances us towards our goal to develop a direct microbial conversion process using this organism. and xylose to produce lipids; however, due to the lack of the biomass degrading enzymes, it cannot directly utilize lignocellulosic substrates as carbon sources. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of

  20. Application of wood chips for soil mulching in the cultivation of ornamental grasses

    Directory of Open Access Journals (Sweden)

    Henschke Monika

    2016-12-01

    Full Text Available A mulch is a layer of material applied to the surface of the soil. Mulching plays an important role in the maintenance of green spaces. Organic materials are still sought for the preparation of mulches. Recently interest in wood chips has grown. The aim of the study was to determine the effect of mulching with pine and birch chips on the contents of phenolic compounds in the soil, as well as on the growth and flowering of ornamental grasses – Bouteloua gracilis (Kunth. Lag. ex Griffiths, Panicum virgatum L. and Pennisetum alopecuroides L. The content of phenolic compounds in the soil steadily increased from spring to autumn. Mulching led to a substantial increase in the level of phenolic compounds. In the first year of cultivation more phenolic compounds were released by chips of pine than birch, while in the second year this difference did not occur. Mulching had a negative impact on the growth and flowering of ornamental grasses, especially in the first year of cultivation. Ornamental grass sensitivity to the substances released from mulches decreased with the age of the plants and was dependent on the species – Bouteloua gracilis was found to be particularly sensitive.

  1. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  2. Lignin-Retaining Transparent Wood.

    Science.gov (United States)

    Li, Yuanyuan; Fu, Qiliang; Rojas, Ramiro; Yan, Min; Lawoko, Martin; Berglund, Lars

    2017-09-11

    Optically transparent wood, combining optical and mechanical performance, is an emerging new material for light-transmitting structures in buildings with the aim of reducing energy consumption. One of the main obstacles for transparent wood fabrication is delignification, where around 30 wt % of wood tissue is removed to reduce light absorption and refractive index mismatch. This step is time consuming and not environmentally benign. Moreover, lignin removal weakens the wood structure, limiting the fabrication of large structures. A green and industrially feasible method has now been developed to prepare transparent wood. Up to 80 wt % of lignin is preserved, leading to a stronger wood template compared to the delignified alternative. After polymer infiltration, a high-lignin-content transparent wood with transmittance of 83 %, haze of 75 %, thermal conductivity of 0.23 W mK -1 , and work-tofracture of 1.2 MJ m -3 (a magnitude higher than glass) was obtained. This transparent wood preparation method is efficient and applicable to various wood species. The transparent wood obtained shows potential for application in energy-saving buildings. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  3. Radioactivity of Wood and Environment

    International Nuclear Information System (INIS)

    Hus, M.; Kosutic, K.; Lulic, S.

    2003-01-01

    Nuclear experiments in the atmosphere and nuclear accidents caused global deposition of artificial radionuclides in the soil of Earth's northern hemisphere, the territory of the Republic of Croatia included. Soil contamination by radionuclides resulted in their deposition in plants growing on the contaminated soil as well as in the trees. Large area of the Republic of Croatia is covered with wood, which is exploited in manufacture of industrial wood and for firewood. From approximately 3 million cubic metres of wood exploited annually, nearly one third serves for firewood. In the process of burning a smaller portion of radionuclides deposited in the wood evaporates and goes to atmosphere while a larger portion is retained in the ash. In this paper are presented the results of natural radionuclides 4 0K , 2 32T h and 2 38U as well as of artificial radionuclide 1 37C s content determination in the wood, wood briquette, charcoal and in ash remained after burning the wood, wood briquette and charcoal. The obtained results are discussed from wood radiocontamination aspect and from the aspect of potential environmental radiocontamination by the products from wood burning process. (author)

  4. Radioactivity of wood ash

    International Nuclear Information System (INIS)

    Rantavaara, A.; Moring, M.

    2000-01-01

    STUK (Finnish Radiation and Nuclear Safety Authority) has investigated natural and artificial radioactivity in wood ash and radiation exposure from radionuclides in ash since 1996. The aim was to consider both handling of ash and different ways of using ash. In all 87 ash samples were collected from 22 plants using entirely or partially wood for their energy production in 1996-1997. The sites studied represented mostly chemical forest industry, sawmills or district heat production. Most plants used fluidised bed combustion technique. Samples of both fly ash and bottom ash were studied. The activity concentrations of radionuclides in samples of, e.g., dried fly ash from fuel containing more than 80% wood were determined. The means ranged from 2000 to less than 50 Bq kg -1 , in decreasing order: 137 Cs, 40 K, 90 Sr, 210 Pb, 226 Ra, 232 Th, 134 Cs, 235 U. In bott radionuclide contents decreased in the same order as in fly ash, but were smaller, and 210 Pb was hardly detectable. The NH 4 Ac extractable fractions of activities for isotopes of alkaline elements (K, Cs) in bottom ash were lower than in fly ash, whereas solubility of heavier isotopes was low. Safety requirements defined by STUK in ST-guide 12.2 for handling of peat ash were fulfilled at each of the sites. Use of ash for land-filling and construction of streets was minimal during the sampling period. Increasing this type of ash use had often needed further investigations, as description of the use of additional materials that attenuate radiation. Fertilisation of forests with wood ash adds slightly to the external irradiation in forests, but will mostly decrease doses received through use of timber, berries, mushrooms and game meat. (orig.)

  5. Method of stabilizing wood

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  6. Wood Composite Adhesives

    Science.gov (United States)

    Gomez-Bueso, Jose; Haupt, Robert

    The global environment, in which phenolic resins are being used for wood composite manufacture, has changed significantly during the last decade. This chapter reviews trends that are driving the use and consumption of phenolic resins around the world. The review begins with recent data on volume usage and regional trends, followed by an analysis of factors affecting global markets. In a section on environmental factors, the impact of recent formaldehyde emission regulations is discussed. The section on economics introduces wood composite production as it relates to the available adhesive systems, with special emphasis on the technical requirement to improve phenolic reactivity. Advances in composite process technology are introduced, especially in regard to the increased demands the improvements place upon adhesive system performance. The specific requirements for the various wood composite families are considered in the context of adhesive performance needs. The results of research into current chemistries are discussed, with a review of recent findings regarding the mechanisms of phenolic condensation and acceleration. Also, the work regarding alternate natural materials, such as carbohydrates, lignins, tannins, and proteinaceous materials, is presented. Finally, new developments in alternative adhesive technologies are reported.

  7. Radiographic testing of wood

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  8. Wood fuels utilization in Central Europe - the wood fuels consumption and the targets of utilization

    International Nuclear Information System (INIS)

    Alakangas, E.

    1999-01-01

    Following subjects are discussed in this presentation: The share of bioenergy of the total energy consumption in EU region; the wood fuels consumption in EU region in 1995; the division of bioenergy utilization (households, wood- based district heating, wood consumption in industry, power generation from wood and residues, biofuels, biogas and sludges); wood fuels consumption in households in EU countries in 1995; wood consumption in France; the additional wood fuel consumption potential in France; Blan bois - wood energy program; French wood energy markets; German wood energy markets; energy consumption in Germany; wood consumption in Bavaria; the wood fuels potential in Bavaria; wood fuels consumption in households in Bavaria; wood fuels consumption for district heating in Bavaria; fuel prices in Bavaria; Environmental regulations in Germany; small boiler markets in Germany; Energy consumption in Austria; small-scale utilization of wood fuels; utilization of wood energy. (Slides, additional information from the author)

  9. Urban Wood Waste Resource Assessment; TOPICAL

    International Nuclear Information System (INIS)

    Wiltsee, G.

    1998-01-01

    This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris

  10. European wood-fuel trade

    International Nuclear Information System (INIS)

    Hillring, B.; Vinterbaeck, J.

    2001-01-01

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

  11. Assessing the Potential Stem Growth and Quality of Yellow Birch Prior to Restoration: A Case Study in Eastern Canada

    Directory of Open Access Journals (Sweden)

    Alexis Achim

    2013-09-01

    Full Text Available Past silvicultural treatments have resulted in the high-grading mixed temperate forests of Québec, Canada. Despite recognition of this issue, the low occurrence of yellow birch (Betula alleghaniensis Britton within current stands raises questions about the potential of the species to grow and eventually constitute a high-quality forest resource. The objective of this study was to assess this potential using tree characteristics, forest structure and additional site and climatic conditions as predictors. A total of 145 trees were sampled in two areas located in the same bioclimatic zone. Lower-Saguenay-Charlevoix was chosen as an area where a restoration plan could be implemented, whereas Portneuf was selected as a reference. We used nonlinear mixed models to investigate which environmental factors are likely to influence the radial growth and stem quality of yellow birch sample trees. Our results suggest that topographic and climatic conditions, as well as the competitive environment of the trees, are important factors to consider in the evaluation of yellow birch production. Despite the limited occurrence of yellow birch, the potential for growth and quality was high in the Lower-Saguenay-Charlevoix area. For equivalent topographic, climatic, and competitive environment conditions, there was no significant difference in either radial growth or stem quality with Portneuf. We suggest that the economic interest of producing high quality timber should be used to justify the implementation of a restoration strategy in the Lower-Saguenay-Charlevoix area.

  12. The influence of lathe check depth and orientation on the bond quality of phenol-formaldehyde-bonded birch plywood

    Science.gov (United States)

    Anti Rohumaa; Christopher G. Hunt; Mark Hughes; Charles R. Frihart; Janne Logren

    2013-01-01

    During the rotary peeling of veneer for plywood or the laminated veneer lumber manufacture, checks are formed in the veneer that are as deep as 70 – 80 % of the veneer thickness. The results of this study show that, during adhesive bond testing, deep lathe checks in birch (Betula pendula Roth.) veneer significantly reduce the shear strength and the...

  13. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems

    Directory of Open Access Journals (Sweden)

    Markus Armbruster

    2017-03-01

    Full Text Available Triterpene compounds like betulin, betulinic acid, erythrodiol, oleanolic acid and lupeol are known for many pharmacological effects. All these substances are found in the outer bark of birch. Apart from its pharmacological effects, birch bark extract can be used to stabilise semisolid systems. Normally, birch bark extract is produced for this purpose by extraction with organic solvents. Employing supercritical fluid technology, our aim was to develop a birch bark dry extract suitable for stabilisation of lipophilic gels with improved properties while avoiding the use of toxic solvents. With supercritical carbon dioxide, three different particle formation methods from supercritical solutions have been tested. First, particle deposition was performed from a supercritical solution in an expansion chamber. Second, the Rapid Expansion of Supercritical Solutions (RESS method was used for particle generation. Third, a modified RESS-procedure, forming the particles directly into the thereby gelated liquid, was developed. All three methods gave yields from 1% to 5.8%, depending on the techniques employed. The triterpene composition of the three extracts was comparable: all three gave more stable oleogels compared to the use of an extract obtained by organic solvent extraction. Characterizing the rheological behaviour of these gels, a faster gelling effect was seen together with a lower concentration of the extract required for the gel formation with the supercritical fluid (SCF-extracts. This confirms the superiority of the supercritical fluid produced extracts with regard to the oleogel forming properties.

  14. Material properties of plasticized hardwood xylans for potential application as oxygen barrier films.

    Science.gov (United States)

    Gröndahl, Maria; Eriksson, Lisa; Gatenholm, Paul

    2004-01-01

    Free films based on glucuronoxylan isolated from aspen wood were prepared by casting from aqueous solutions and drying in a controlled environment. Addition of xylitol or sorbitol facilitated film formation and thus examination of the material properties of these films. The mechanical properties of the films were evaluated using tensile testing and dynamic mechanical analysis in a controlled ambient relative humidity. The strain at break increased, and the stress at break and Young's modulus of the films decreased with increasing amounts of xylitol and sorbitol due to plasticization. At high amount of plasticizer, it was found that films with xylitol gave lower extensibility. Wide-angle X-ray scattering analysis showed that xylitol crystallized in a distinct phase, which we believe contributes to the more brittle behavior of these films. The effect of the plasticizers on the glass transition temperature was determined using dynamic mechanical analysis and differential scanning calorimetry. An increased amount of plasticizer shifted the glass transition to lower temperatures. The effect of moisture on the properties of plasticized films was investigated using water vapor sorption isotherms and by humidity scans in dynamic mechanical analysis. Sorption isotherms showed a transition from type II to type III when adding plasticizer. The films showed low oxygen permeability and thus have a potential application in food packaging.

  15. Inoculation Expedition of Agar wood

    International Nuclear Information System (INIS)

    Peng, C.S.; Mohd Fajri Osman; Rusli Zakaria

    2015-01-01

    Inoculation expedition of agar wood is a main field works for researcher in Nuclear Malaysia to prove the real inoculation of agar wood in real jungle. These expeditions was conducted fourth times in the jungles of Malaysia including Gunung Tebu in Terengganu, Murum in Belaga, Sarawak, Kampung Timbang in Kota Belud, Sabah and Nuclear Malaysia itself. This expedition starts from preparation of samples and equipment, transportation into the jungle, searching and recognition of agar wood and lastly, inoculation of the agar wood. Safety aspects precedence set out in the preparation and implementation of this expedition. (author)

  16. The wood energy in France

    International Nuclear Information System (INIS)

    Douard, F.; Oremus, Y.; Garsault-Fabbi, A.

    2007-01-01

    The program law fixing the energy policy (POPE Law of the 13 july 2005) fixes an objective of 50% of growth for the renewable heat. As this renewable heat is today generated by the biomass, it seems necessary to adjust all the efforts on this sector. This document proposes to takes stock on the wood energy in France. It presents the wood fuels, an evaluation of the Wood-Energy Plan decided by the ADEME in 2000, the wood heat networks, and some example of installations. (A.L.B.)

  17. Evaluating the efficacy of epinastine ophthalmic solution using a conjunctivitis allergen challenge model in patients with birch pollen allergic conjunctivitis.

    Science.gov (United States)

    Tagawa, Yoshiaki; Namba, Kenichi; Nakazono, Yumi; Iwata, Daiju; Ishida, Susumu

    2017-04-01

    The efficacy of epinastine 0.05% ophthalmic solution for pollen allergic conjunctivitis has already been shown in a conjunctival allergen challenge (CAC) test using cedar pollen as a challenge. The present study investigated the efficacy of this solution against birch pollen conjunctivitis in a CAC test. Ten adult subjects (eight males and two females) with asymptomatic birch pollen conjunctivitis were enrolled in this study. The average age of the subjects was 41.1 years. This study was conducted during a period without birch pollen dispersion. In each subject, the epinastine 0.05% ophthalmic solution was instilled in one eye, and an artificial tear fluid was instilled in the fellow eye in a double-blind manner. Five minutes or 4 h after the drug instillation, both eyes were challenged with an optimal concentration of birch pollen, and ocular itching and conjunctival hyperemia were then graded. Tears were collected before the drug instillation and 20 min after the pollen challenge, and the histamine level was measured. The ocular itching scores and palpebral conjunctival hyperemia scores of the epinastine-treated eyes were significantly lower than those of the contralateral control eyes when the eyes were pretreated with the drug 4 h before the CAC. There was a significant correlation between the tear histamine level and mean ocular itching score of three time points (3, 5 and 10 min) following the CAC in the control eyes but not the epinastine-treated eyes. Epinastine is effective in suppressing ocular itching and conjunctival hyperemia in birch pollen conjunctivitis. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  18. Corrosion of Fasteners in Wood Treated with Newer Wood Preservatives

    Science.gov (United States)

    Samuel L. Zelinka

    2013-01-01

    This document compiles recent research findings related to corrosion of metals in preservative treated wood into a single report on corrosion of metals in wood. The research was conducted as part of the Research, Technology and Education portion of the National Historic Covered Bridge Preservation (NHCBP) Program administered by the Federal Highway Administration. The...

  19. Survival, growth, wood basic density and wood biomass of seven ...

    African Journals Online (AJOL)

    A performance comparison of seven-year-old individuals of 13 Casuarina species/provenances in terms of survival, growth (diameter, height and volume), wood basic density and wood biomass was undertaken at Kongowe, Kibaha, Tanzania. The trial was laid out using a randomised complete block design with four ...

  20. Quantifying arthropod contributions to wood decay

    Science.gov (United States)

    Michael Ulyshen; Terry Wagner

    2013-01-01

    Termites carry large amounts of soil into dead wood, and this behaviour complicates efforts to measure their contributions to wood decay. A novel method for isolating termite soil by burning the wood is described, and some preliminary results are presented.

  1. Determining the age of CO2 Released From Mountain Birch Forest and Heath in Arctic Sweden

    Science.gov (United States)

    Hartley, I. P.; Garnett, M. H.; Hopkins, D. W.; Sommerkorn, M.; Wookey, P. A.

    2008-12-01

    Nuclear weapons testing released a large amount of 14C into the atmosphere during the mid 20th Century. This radiocarbon pulse provides a tracer that can be used to determine the age of C released from plants and soils. Such information is critical for predicting how terrestrial C storage will respond to global change. If respired CO2 is mainly modern, then respiration and photosynthesis are tightly coupled. In contrast, if older C is being mineralized then there is more potential for climate change to induce C loss. We carried out one of the first studies to measure seasonal variations in the 14C content of CO2 released from arctic ecosystems. Using molecular sieves, we trapped CO2 respired from a mountain birch forest and heath near Abisko, northern Sweden and measured 14C contents by accelerator mass spectrometry. CO2 was collected from both vegetated plots (control) and clipped and trenched plots (CT) on three occasions during the 2007 growing season. In addition, we used a new passive sampling technique to collect CO2 from the CT plots during winter 2007-2008. Assuming that the respired C was derived from post bomb sources (justifiable as the majority of each soil profile was enriched with bomb C), we estimated the age of the CO2 and how it changed during the year in response to changes in plant activity and key environmental drivers. On the heath, the mean age of the CO2 respired from the control plots increased from 4 to 6 years old during the growing season. The CO2 respired from the CT plots increased from 5 years old in early June to 11 years old by July, but then declined to 8 years old in September. The C released during winter was also 8 years old. In the Birch forest, the mean age of CO2 respired from the CT plots increased from 4 years old in late May to 8-9 years old during July and September. However, during winter, the CO2 released was >10 years old. In the control plots, the age of respired CO2 increased from being 1 year old in late May to 6

  2. Chain-brush method in delimbing and debarking of wood; Ketjuharja-menetelmae puun karsinnassa ja kuorinnassa

    Energy Technology Data Exchange (ETDEWEB)

    Aho, V J; Nikala, L; Laitinen, H [VTT Energy, Jyvaeskylae (Finland)

    1997-12-01

    The objective of this project is to study, develop and make an integrated method for production of wood fuels and industrial raw material, promoting the competitiveness of the refining and energy usage of felling residues based on chain-brush delimbing-debarking technology, operational. VTT Energy has tested different brush constructions and the thickness of chains using varying feeding speeds and rotation speeds of the brush-delimber. First thinning pine, spruce and birch have been tested as single trees. Different temperatures have been used in the summer, and frozen timber in the winter. A method has been developed for estimation of the bark content and the wood losses for pine. The method is based on the measurement of the areas covered by bark and the debarked areas of the timber, on the bark thickness values and dry substance content of the wood obtained from the literature, as well as on the calculation formulas obtained from these. Unscrambler software will be used to assist the planning of the tests, and for analysing of the results. The utilisation of the chain-brush method for different wood-species, and the effect of different chain adjustments will be simulated by the software. The chain-brush delimbing will be studied using the high-speed camera acquired to VTT Energy. (orig.)

  3. Furfural Production from d-Xylose and Xylan by Using Stable Nafion NR50 and NaCl in a Microwave-Assisted Biphasic Reaction

    Directory of Open Access Journals (Sweden)

    Sarah Le Guenic

    2016-08-01

    Full Text Available Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME biphasic system under microwave irradiation. Heated up between 170 and 190 °C in the presence of Nafion NR50 and NaCl, d-xylose, l-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered.

  4. Furfural Production from d-Xylose and Xylan by Using Stable Nafion NR50 and NaCl in a Microwave-Assisted Biphasic Reaction.

    Science.gov (United States)

    Le Guenic, Sarah; Gergela, David; Ceballos, Claire; Delbecq, Frederic; Len, Christophe

    2016-08-22

    Pentose dehydration and direct transformation of xylan into furfural were performed in a water-cyclopentyl methyl ether (CPME) biphasic system under microwave irradiation. Heated up between 170 and 190 °C in the presence of Nafion NR50 and NaCl, d-xylose, l-arabinose and xylan gave furfural with maximum yields of 80%, 42% and 55%, respectively. The influence of temperature and reaction time on the reaction kinetics was discussed. This study was also completed by the survey of different reactant ratios, such as organic layer-water or catalyst-inorganic salt ratios. The exchange between proton and cation induced by an excess of NaCl was monitored, and a synergetic effect between the remaining protons and the released HCl was also discovered.

  5. Wood pole overhead lines

    CERN Document Server

    Wareing, Brian

    2005-01-01

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

  6. Production of bio-oil via hydrothermal liquefaction of birch sawdust

    International Nuclear Information System (INIS)

    Malins, Kristaps

    2017-01-01

    Highlights: • NaOH has significant impact on hydrothermal liquefaction of birch sawdust. • High yield of bio-oil (54.1%) was obtained under developed optimal conditions. • Compounds in bio-oil have appropriate chemical structure for hydrocarbon synthesis. • The yield of marketable solid residue with potential for industrial application was 7.1%. • Solid residue has high calorific value (29.8 MJ/kg) and C content (74.6 wt.%). - Abstract: The effect of weight ratio of plywood manufacturing by-product birch sawdust (BS) to water (1/2–1/8), reaction temperature (200–340 °C), initial H 2 pressure (0–10 MPa), residence time (5–90 min), catalysts amount (0.25–7.0 wt.%) and type (FeSO 4 , ZnSO 4 , NiSO 4 , Raney-nickel, Ni65%/SiO 2 −Al 2 O 3 , Na 2 CO 3 and NaOH) on hydrothermal liquefaction of BS was investigated. High yield of bio-oil (54.1%) with calorific value (CV) 24.9 MJ/kg under developed optimal experimental conditions in the presence of NaOH (5 wt.%) utilizing weight ratio of BS to water 1/4, residence time 5 min, mixing speed 250 rpm at 300 °C without pressurized particular inert gas or H 2 atmosphere was achieved. Compounds in bio-oil analyzed by gas chromatography-mass spectrometry (GC-MS) have suitable chemical structures for conversion into renewable hydrocarbons. Marketable solid residue (SR) with yield 7.1%, high CV (29.8 MJ/kg) and perspective characteristics for industrial application was obtained. Produced gas in process analyzed by gas chromatography-thermal conductivity detector (GC–TCD) contains 60.1 vol.% of CO 2 .

  7. Chemical modification of birch allergen extract leads to a reduction in allergenicity as well as immunogenicity.

    Science.gov (United States)

    Würtzen, Peter Adler; Lund, Lise; Lund, Gitte; Holm, Jens; Millner, Anders; Henmar, Helene

    2007-01-01

    In Europe, specific immunotherapy is currently conducted with vaccines containing allergen preparations based on intact extracts. In addition to this, chemically modified allergen extracts (allergoids) are used for specific allergy treatment. Reduced allergenicity and thereby reduced risk of side effects in combination with retained ability to activate T cells and induce protective allergen-specific antibody responses has been claimed for allergoids. In the current study, we compared intact allergen extracts and allergoids with respect to allergenicity and immunogenicity. The immunological response to birch allergen extract, alum-adsorbed extract, birch allergoid and alum-adsorbed allergoid was investigated in vitro in human basophil histamine release assay and by stimulation of human allergen-specific T cell lines. In vivo, Bet v 1-specific IgG titers in mice were determined after repetitive immunizations. In all patients tested (n = 8), allergoid stimulations led to reduced histamine release compared to the intact allergen extract. However, the allergoid preparations were not recognized by Bet v 1-specific T cell lines (n = 7), which responded strongly to the intact allergen extract. Mouse immunizations showed a clearly reduced IgG induction by allergoids and a strongly potentiating effect of the alum adjuvant. Optimal IgG titers were obtained after 3 immunizations with intact allergen extracts, while 5 immunizations were needed to obtain maximal response to the allergoid. The reduced histamine release observed for allergoid preparations may be at the expense of immunological efficacy because the chemical modifications lead to a clear reduction in T cell activation and the ability to induce allergen-specific IgG antibody responses. Copyright 2007 S. Karger AG, Basel.

  8. Asparagus IRX9, IRX10, and IRX14A Are Components of an Active Xylan Backbone Synthase Complex that Forms in the Golgi Apparatus1[OPEN

    Science.gov (United States)

    Zeng, Wei; Picard, Kelsey L.; Song, Lili; Wu, Ai-Min; Farion, Isabela M.; Zhao, Jia; Ford, Kris; Bacic, Antony

    2016-01-01

    Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana. We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis. PMID:26951434

  9. Asparagus IRX9, IRX10, and IRX14A Are Components of an Active Xylan Backbone Synthase Complex that Forms in the Golgi Apparatus.

    Science.gov (United States)

    Zeng, Wei; Lampugnani, Edwin R; Picard, Kelsey L; Song, Lili; Wu, Ai-Min; Farion, Isabela M; Zhao, Jia; Ford, Kris; Doblin, Monika S; Bacic, Antony

    2016-05-01

    Heteroxylans are abundant components of plant cell walls and provide important raw materials for the food, pharmaceutical, and biofuel industries. A number of studies in Arabidopsis (Arabidopsis thaliana) have suggested that the IRREGULAR XYLEM9 (IRX9), IRX10, and IRX14 proteins, as well as their homologs, are involved in xylan synthesis via a Golgi-localized complex termed the xylan synthase complex (XSC). However, both the biochemical and cell biological research lags the genetic and molecular evidence. In this study, we characterized garden asparagus (Asparagus officinalis) stem xylan biosynthesis genes (AoIRX9, AoIRX9L, AoIRX10, AoIRX14A, and AoIRX14B) by heterologous expression in Nicotiana benthamiana We reconstituted and partially purified an active XSC and showed that three proteins, AoIRX9, AoIRX10, and AoIRX14A, are necessary for xylan xylosyltranferase activity in planta. To better understand the XSC structure and its composition, we carried out coimmunoprecipitation and bimolecular fluorescence complementation analysis to show the molecular interactions between these three IRX proteins. Using a site-directed mutagenesis approach, we showed that the DxD motifs of AoIRX10 and AoIRX14A are crucial for the catalytic activity. These data provide, to our knowledge, the first lines of biochemical and cell biological evidence that AoIRX9, AoIRX10, and AoIRX14A are core components of a Golgi-localized XSC, each with distinct roles for effective heteroxylan biosynthesis. © 2016 American Society of Plant Biologists. All Rights Reserved.

  10. Wood-related occupations, wood dust exposure, and sinonasal cancer.

    Science.gov (United States)

    Hayes, R B; Gerin, M; Raatgever, J W; de Bruyn, A

    1986-10-01

    A case-control study was conducted to examine the relations between type of woodworking and the extent of wood dust exposure to the risks for specific histologic types of sinonasal cancer. In cooperation with the major treatment centers in the Netherlands, 116 male patients newly diagnosed between 1978 and 1981 with primary malignancies of epithelial origin of this site were identified for study. Living controls were selected from the municipal registries, and deceased controls were selected from the national death registry. Interviews were completed for 91 (78%) cases and 195 (75%) controls. Job histories were coded by industry and occupation. An index of exposure was developed to classify the extent of occupational exposure to wood dust. When necessary, adjustment was made for age and usual cigarette use. The risk for nasal adenocarcinoma was elevated by industry for the wood and paper industry (odds ratio (OR) = 11.9) and by occupation for those employed in furniture and cabinet making (OR = 139.8), in factory joinery and carpentry work (OR = 16.3), and in association with high-level wood dust exposure (OR = 26.3). Other types of nasal cancer were not found to be associated with wood-related industries or occupations. A moderate excess in risk for squamous cell cancer (OR = 2.5) was associated with low-level wood dust exposure; however, no dose-response relation was evident. The association between wood dust and adenocarcinoma was strongest for those employed in wood dust-related occupations between 1930 and 1941. The risk of adenocarcinoma did not appear to decrease for at least 15 years after termination of exposure to wood dust. No cases of nasal adenocarcinoma were observed in men whose first exposure to wood dust occurred after 1941.

  11. Synthesis of Acylated Xylan-Based Magnetic Fe3O4 Hydrogels and Their Application for H2O2 Detection

    Directory of Open Access Journals (Sweden)

    Qing-Qing Dai

    2016-08-01

    Full Text Available Acylated xylan-based magnetic Fe3O4 nanocomposite hydrogels (ACX-MNP-gels were prepared by fabricating Fe3O4 nanoctahedra in situ within a hydrogel matrix which was synthesized by the copolymerization of acylated xylan (ACX with acrylamide and N-isopropylacrylamide under ultraviolet irradiation. The size of the Fe3O4 fabricated within the hydrogel matrix could be adjusted through controlling the crosslinking concentrations (C. The magnetic hydrogels showed desirable magnetic and mechanical properties, which were confirmed by XRD, Raman spectroscopy, physical property measurement system, SEM, TGA, and compression test. Moreover, the catalytic performance of the magnetic hydrogels was explored. The magnetic hydrogels (C = 7.5 wt % presented excellent catalytic activity and provided a sensitive response to H2O2 detection even at a concentration level of 5 × 10−6 mol·L−1. This approach to preparing magnetic hydrogels loaded with Fe3O4 nanoparticles endows xylan-based hydrogels with new promising applications in biotechnology and environmental chemistry.

  12. Aquatic wood -- an insect perspective

    Science.gov (United States)

    Peter S. Cranston; Brendan McKie

    2006-01-01

    Immersed wood provides refugia and substrate for a diverse array of macroinvertebrates, and food for a more restricted genuinely xylophagous fauna. Worldwide, xylophages are found across aquatic insect orders, including Coleoptera, Diptera, Trichoptera and Plecoptera. Xylophages often are specialised, feeding on the wood surface or mining deep within. Many feed...

  13. The wood of Merovingian weaponry

    Czech Academy of Sciences Publication Activity Database

    Tegel, W.; Muigg, B.; Büntgen, Ulf

    2016-01-01

    Roč. 65, JAN (2016), s. 148-153 ISSN 0305-4403 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : Early Middle Ages * Merovingian weaponry * Mineralised wood * Wood anatomy Subject RIV: EH - Ecology, Behaviour Impact factor: 2.602, year: 2016

  14. Assessing potential sustainable wood yield

    Science.gov (United States)

    Robert F. Powers

    2001-01-01

    Society is making unprecedented demands on world forests to produce and sustain many values. Chief among them is wood supply, and concerns are rising globally about the ability of forests to meet increasing needs. Assessing this is not easy. It requires a basic understanding of the principles governing forest productivity: how wood yield varies with tree and stand...

  15. Preservation of forest wood chips

    Energy Technology Data Exchange (ETDEWEB)

    Kofman, P.D.; Thomsen, I.M.; Ohlsson, C.; Leer, E.; Ravn Schmidt, E.; Soerensen, M.; Knudsen, P.

    1999-01-01

    As part of the Danish Energy Research Programme on biomass utilisation for energy production (EFP), this project concerns problems connected to the handling and storing of wood chips. In this project, the possibility of preserving wood chips of the Norway Spruce (Picea Abies) is addressed, and the potential improvements by anaerobic storage are tested. Preservation of wood chips aims at reducing dry matter losses from extensive heating during storage and to reduce production of fungal spores. Fungal spores pose a health hazards to workers handling the chips. Further the producers of wood chips are interested in such a method since it would enable them to give a guarantee for the delivery of homogeneous wood chips also during the winter period. Three different types of wood chips were stored airtight and further one of these was stored in accordance with normal practise and use as reference. The results showed that airtight storage had a beneficial impact on the quality of the chips: no redistribution of moisture, low dry matter losses, unfavourable conditions for microbial activity of most fungi, and the promotion of yeasts instead of fungi with airborne spores. Likewise the firing tests showed that no combustion problems, and no increased risk to the environment or to the health of staff is caused by anaerobic storage of wood chips. In all, the tests of the anaerobic storage method of forest wood chips were a success and a large-scale test of the method will be carried out in 1999. (au)

  16. The sustainable wood production initiative.

    Science.gov (United States)

    Robert. Deal

    2004-01-01

    To address concerns about sustainable forestry in the region, the Focused Science Delivery Program is sponsoring a three year Sustainable Wood Production Initiative. The Pacific Northwest is one of the world's major timber producing regions, and the ability of this region to produce wood on a sustained yield basis is widely recognized. Concerns relating to the...

  17. Composites from wood and plastics

    Science.gov (United States)

    Craig Clemons

    2010-01-01

    Composites made from thermoplastics and fillers or reinforcements derived from wood or other natural fibers are a dynamic research area encompassing a wide variety of composite materials. For example, as the use of biopolymers grows, wood and other natural fiber sources are being investigated as renewable sources of fillers and reinforcements to modify performance....

  18. Moisture transport in coated wood

    NARCIS (Netherlands)

    Meel, P.A. van; Erich, S.J.F.; Huinink, H.P.; Kopinga, K.; Jong, J. DE; Adan, O.C.G.

    2011-01-01

    Moisture accumulation inside wood causes favorable conditions for decay. Application of a coating alters the moisture sorption of wood and prevents accumulation of moisture. This paper presents the results of a nuclear magnetic resonance (NMR) study on the influence of a coating on the moisture

  19. Holistic approach to wood protection

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

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

  20. Measuring wood specific gravity, correctly

    Science.gov (United States)

    G. Bruce Williamson; Michael C. Wiemann

    2010-01-01

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

  1. 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...

  2. On Erdos–Wood's conjecture

    Indian Academy of Sciences (India)

    In this article, we prove that infinite number of integers satsify Erdős–Woods conjecture. Moreover, it follows that the number of natural numbers ≤ satisfies Erdős–Woods conjecture with = 2 is at least /(log ) for some positive constant > 2.

  3. The Swedish wood fuel market

    International Nuclear Information System (INIS)

    Hillring, Bengt

    1999-01-01

    In Sweden, wood fuels are traditionally used in the Swedish forest products industry and for heating of single-family houses. More recently they are also become established as an energy source for district heating and electricity production. Energy policy, especially the energy taxation system, has favoured wood fuels and other biofuels, mainly for environmental reasons. There is now an established commercial market for wood fuels in the district heating sector, which amounts to 45 PJ and is growing 20 per cent annually. Price levels have been stable in current prices for a decade, mainly because of good access to wood fuels. Price levels are dominated by production costs on a market that is largely governed by the buyer. It is expected that the use of wood fuels will increased in Sweden in the future, which will push a further development of this section on the market and bring about technological changes in the area. (Author)

  4. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

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

  5. Hourly pattern of allergenic alder and birch pollen concentrations in the air: Spatial differentiation and the effect of meteorological conditions

    Science.gov (United States)

    Borycka, K.; Kasprzyk, I.

    2018-06-01

    In temperate climate widespread alder and birch are an important source of strong aeroallergens. The diurnal pattern of airborne pollen concentrations depends on the rhythm of pollen release from anthers as well as weather conditions, convection air currents, long-distance transport, pollen trap location and local vegetation. The aim of the study was to present a diurnal pattern of Alnus (alder) and Betula (birch) pollen concentrations in the air in a horizontal and vertical gradient and examine the weather parameters that had the greatest impact on the pattern. The study was conducted in Rzeszów City, southeast Poland over three years. Pollen grains were collected using a Hirst volumetric spore trap at three sampling points: two at 12 m the agl, and one at 1.5 m agl. Data were analysed using circular statistics and a nonlinear function. For alder, three models of hourly patterns were elaborated and the most common presented early morning minimum and early afternoon maximum. For birch, the most common model has one peak at night and a marked decrease in concentrations in early morning, although a second model has peak during early afternoon. A model with 3 peaks is much less common. These models are characteristic for warm temperate climate regions, where alders and birches are common. The diurnal patterns did not depend on the localization of traps or proximity of the pollen source, although these factors influenced the hourly concentrations, with higher values observed at roof level. Significant relationships between the hourly pollen counts and meteorological parameters were observed only for alder. Three incidents of increasing birch pollen concentrations were observed during the first two hours of precipitation and linked to a convection effect. Unstable weather conditions caused by air convection might strongly modify the circadian pattern and cause the nightly peaks concentrations. The general results are that people suffering from allergies may be exposed

  6. Projected wood energy impact on US forest wood resources

    Energy Technology Data Exchange (ETDEWEB)

    Skog, K.E. [USDA Forest Service, Madison, WI (United States)

    1993-12-31

    The USDA Forest Service has developed long-term projections of wood energy use as part of a 1993 assessment of demand for and supply of resources from forest and range lands in the United States. To assess the impact of wood energy demand on timber resources, a market equilibrium model based on linear programming was developed to project residential, industrial, commercial, and utility wood energy use from various wood energy sources: roundwood from various land sources, primary wood products mill residue, other wood residue, and black liquor. Baseline projections are driven by projected price of fossil fuels compared to price of wood fuels and the projected increase in total energy use in various end uses. Wood energy use is projected to increase from 2.67 quad in 1986 to 3.5 quad in 2030 and 3.7 quad in 2040. This is less than the DOE National Energy Strategy projection of 5.5 quad in 2030. Wood energy from forest sources (roundwood) is projected to increase from 3.1 billion (10{sup 9}) ft{sup 3} in 1986 to 4.4. billion ft{sup 3} in 2030 and 4.8 billion ft{sup 3} in 2040 (88, 124 and 136 million m{sup 3}, respectively). This rate of increase of roundwood use for fuel -- 0.8 percent per year -- is virtually the same as the projected increase rate for roundwood for pulpwood. Pulpwood roundwood is projected to increase from 4.2 billion ft{sup 3} in 1986 to 6.0 billion ft{sup 3} in 2030 and 6.4 billion ft{sup 3} in 2040 (119, 170 and 183 million m{sup 3}, respectively).

  7. Pelletizing and combustion of wood from thinning; Pelletering och foerbraenning av gallringsvirke

    Energy Technology Data Exchange (ETDEWEB)

    Oerberg, Haakan; Thyrel, Mikael; Kalen, Gunnar; Larsson, Sylvia

    2007-12-14

    This work has been done in order to find new raw material sources for an expanding pellet industry, combined with finding a use for a forest product that has no market today. The raw material has been forest from early thinning in two typical stands in Vaesterbotten. The purpose has been to evaluate this material as a raw material for producing pellets. Two typical stands have been chosen. One stand with only pine trees and one mixed stand dominated by birch. The soil of these stands was poor. Half of the trees were delimbed by harvest and half of the trees were not delimbed. This formed four different assortments that were handled in the study. After harvesting the assortments were transported to an asphalt area to be stored. Half of the material was stored during one summer and half of the material was stored during one year and one summer. The different assortments were upgraded to pellets and test combusted in the research plant BTC at the Swedish University of Agricultural Sciences, in Umeaa. The upgrading process contains of the following steps: 1.Chipping by a mobile chipper. 2.Low temperature drying (85 deg C). 3. Coarse shredding ({phi}15 mm). 4. Fine shredding ({phi}4-6 mm) and 5. Pelletizing (Die: {phi}8). Samples for fuel analysis were taken during the chipping. Analyses shows that the net calorific value for delimbed assortments are about 0,3 MJ/kg DM higher than for limbed assortments. Pellets made of the assortments Mixed limbed and Pine limbed has shown a net calorific value comparable to stem wood pellets. Pellets made of Birch delimbed show a net calorific value 0,4 MJ/kg DM lower than stem wood pellets. Analyses show that ash contents of the assortment Mixed delimbed was 1 %-unit higher compared to stem wood pellets. The assortment Pine delimbed and Birch delimbed has showed an ash contents comparable with stem wood pellets. The ash melting characteristics can reduce the value of a raw material. Low ash melting temperature for a fuel might cause

  8. [Altitude-belt zonality of wood vegetation within mountainous regions of the Sayan Mountains: a model of ecological second-order phase transitions ].

    Science.gov (United States)

    Sukhovol'skiĭ, V G; Ovchinnikova, T M; Baboĭ, S D

    2014-01-01

    As a description of altitude-belt zonality of wood vegetation, a model of ecological second-order transitions is proposed. Objects of the study have been chosen to be forest cenoses of the northern slope of Kulumyss Ridge (the Sayan Mauntains), while the results are comprised by the altitude profiles of wood vegetation. An ecological phase transition can be considered as the transition of cenoses at different altitudes from the state of presence of certain tree species within the studied territory to the state of their absence. By analogy with the physical model of second-order, phase transitions the order parameter is introduced (i.e., the area portion occupied by a single tree species at the certain altitude) as well as the control variable (i.e., the altitude of the wood vegetation belt). As the formal relation between them, an analog of the Landau's equation for phase transitions in physical systems is obtained. It is shown that the model is in a good accordance with the empirical data. Thus, the model can be used for estimation of upper and lower boundaries of altitude belts for individual tree species (like birch, aspen, Siberian fir, Siberian pine) as well as the breadth of their ecological niches with regard to altitude. The model includes also the parameters that describe numerically the interactions between different species of wood vegetation. The approach versatility allows to simplify description and modeling of wood vegetation altitude zonality, and enables assessment of vegetation cenoses response to climatic changes.

  9. How the user can influence particulate emissions from residential wood and pellet stoves: Emission factors for different fuels and burning conditions

    Science.gov (United States)

    Fachinger, Friederike; Drewnick, Frank; Gieré, Reto; Borrmann, Stephan

    2017-06-01

    For a common household wood stove and a pellet stove we investigated the dependence of emission factors for various gaseous and particulate pollutants on burning phase, burning condition, and fuel. Ideal and non-ideal burning conditions (dried wood, under- and overload, small logs, logs with bark, excess air) were used. We tested 11 hardwood species (apple, ash, bangkirai, birch, beech, cherry, hickory, oak, olive, plum, sugar maple), 4 softwood species (Douglas fir, pine, spruce, spruce/fir), treated softwood, beech and oak wood briquettes, paper briquettes, brown coal, wood chips, and herbaceous species (miscanthus, Chinese silver grass) as fuel. Particle composition (black carbon, non-refractory, and some semi-refractory species) was measured continuously. Repeatability was shown to be better for the pellet stove than for the wood stove. It was shown that the user has a strong influence on wood stove emission behavior both by selection of the fuel and of the burning conditions: Combustion efficiency was found to be low at both very low and very high burn rates, and influenced particle properties such as particle number, mass, and organic content in a complex way. No marked differences were found for the emissions from different wood species. For non-woody fuels, much higher emission factors could be observed (up to five-fold increase). Strongest enhancement of emission factors was found for burning of small or dried logs (up to six-fold), and usage of excess air (two- to three-fold). Real world pellet stove emissions can be expected to be much closer to laboratory-derived emission factors than wood stove emissions, due to lower dependence on user operation.

  10. Diagnostic value of scratch-chamber test, skin prick test, histamine release and specific IgE in birch-allergic patients with oral allergy syndrome to apple

    DEFF Research Database (Denmark)

    Osterballe, M; Scheller, R; Stahl Skov, P

    2003-01-01

    BACKGROUND: The aim of the study was to examine the diagnostic value of skin prick test (SPT), scratch-chamber test (SCT), histamine release (HR) and specific immunoglobulin E (IgE) in birch-allergic patients with oral allergy syndrome to apple. METHODS: Ten birch-allergic patients with oral...... a detailed case history about symptoms of oral allergy syndrome combined with a SPT with fresh apple peel or A72 will be useful....

  11. Cooling of wood briquettes

    Directory of Open Access Journals (Sweden)

    Adžić Miroljub M.

    2013-01-01

    Full Text Available This paper is concerned with the experimental research of surface temperature of wood briquettes during cooling phase along the cooling line. The cooling phase is an important part of the briquette production technology. It should be performed with care, otherwise the quality of briquettes could deteriorate and possible changes of combustion characteristics of briquettes could happen. The briquette surface temperature was measured with an IR camera and a surface temperature probe at 42 sections. It was found that the temperature of briquette surface dropped from 68 to 34°C after 7 minutes spent at the cooling line. The temperature at the center of briquette, during the 6 hour storage, decreased to 38°C.

  12. Wood power in North Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Cleland, J.G.; Guessous, L. [Research Triangle Institute, Research Triangle Park, NC (United States)

    1993-12-31

    North Carolina (NC) is one of the most forested states, and supports a major wood products industry. The NC Department of Natural Resources sponsored a study by Research Triangle Institute to examine new, productive uses of the State`s wood resources, especially electric power generation by co-firing with coal. This paper summarizes our research of the main factors influencing wood power generation opportunities, i.e., (1) electricity demand; (2) initiative and experience of developers; (3) available fuel resources; (4) incentives for alternate fuels; and (5) power plant technology and economics. The results cover NC forests, short rotation woody crops, existing wood energy facilities, electrical power requirements, and environmental regulations/incentives. Quantitative assessments are based on the interests of government agencies, utilities, electric cooperatives, developers and independent power producers, forest products industries, and the general public. Several specific, new opportunities for wood-to-electricity in the State are identified and described. Comparisons are made with nationwide resources and wood energy operations. Preferred approaches in NC are co-generation in existing or modified boilers and in dedicated wood power plants in forest industry regions. Co-firing is mainly an option for supplementing unreliable primary fuel supplies to existing boilers.

  13. Wood would burn

    International Nuclear Information System (INIS)

    Swithenbank, Jim; Chen, Qun; Zhang, Xiaohui; Sharifi, Vida; Pourkashanian, Mohamed

    2011-01-01

    Absract: In view of the world-wide problem of energy sustainability and greenhouse gas production (carbon dioxide), it is timely to review the issues involved in generating heat and power from all fuels and especially new (to the UK) solid fuels, including high moisture fuels such as wood, SRF, oil shale, tar sands and brown coal, which will become major international fuels as oil and gas become depleted. The combustion properties of some of these materials are significantly different from traditional coal, oil and gas fuels, however the technology proposed herein is also applicable to these conventional fuels. This paper presents some innovative combustion system options and the associated technical factors that must be considered for their implementation. For clarity of understanding, the novel concepts will be largely presented in terms of a currently developing solid fuel market; biomass wood chips. One of the most important characteristics of many solid fuels to be used in the future (including oil shale and brown coal) is their high moisture content of up to 60%. This could be removed by utilising low grade waste heat that is widely available in industry to dry the fuel and thus reduce transport costs. Burning such dried wood for power generation also increases the energy available from combustion and thus acts as a thermal transformer by upgrading the low grade heat to heat available at combustion temperatures. The alternative approach presented here is to recover the latent heat by condensing the extrinsic moisture and the water formed during combustion. For atmospheric combustion, the temperature of the condensed combustion products is below the dew point at about 55-65 o C and is only suitable for recovery in an efficient district heating system. However, in order to generate power from the latent heat, the condensation temperature must be increased to the level where the heat can be used in the thermodynamic power cycle. This can be achieved by

  14. Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction

    International Nuclear Information System (INIS)

    Darbah, Joseph N.T.; Kubiske, Mark E.; Nelson, Neil; Oksanen, Elina; Vapaavuori, Elina; Karnosky, David F.

    2008-01-01

    We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO 2 and/or O 3 on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO 2 increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O 3 also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO 2 + O 3 ) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO 2 may have a largely positive impact on forest tree reproduction and regeneration while elevated O 3 will likely have a negative impact. - In this study, we found that elevated CO 2 enhances and elevated O 3 decreases birch reproduction and early seedling growth

  15. COMBUSTION PROPERTIES OF EUCALYPTUS WOOD

    Directory of Open Access Journals (Sweden)

    Yalçın ÖRS

    1999-03-01

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

  16. Wood fuels sources and markets

    International Nuclear Information System (INIS)

    Koopmans, Auke

    2003-01-01

    Biomass energy is an important source of energy in most Asian countries. Households and industries use substantial amounts of fuel wood, charcoal and other biomass energy, such as agricultural residues, dung, leaves and sawmill residues. The main household applications are cooking and heating whereas industrial applications range widely. This paper provides an overview of estimates on the production and trade of biomass fuels in the South-east Asia region. The flows and channels used in the supply of wood fuels in different countries were analysed. This paper may help in identifying policy gaps with regards to the supply and consumption of wood fuels from both forest and non-forest sources. (Author)

  17. Fire Safety Design of Wood Structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2006-01-01

    Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections.......Lecture Notes on Fire Safety Design of Wood Structures including charring of wood and load bearing capacity of beams, columns, and connections....

  18. Moisture relations and physical properties of wood

    Science.gov (United States)

    Samuel V. Glass; Samuel L. Zelinka

    2010-01-01

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

  19. The challenge of bonding treated wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    Wood products are quite durable if exposure to moisture is minimized; however, most uses of wood involve considerable exposure to moisture. To preserve the wood, chemicals are used to minimize moisture pickup, to prevent insect attack, and/or to resist microbial growth. The chemicals used as preservatives can interfere with adhesive bonds to wood. Given the many...

  20. FIRE INSURANCE AND WOOD SCHOOL BUILDINGS.

    Science.gov (United States)

    PURCELL, FRANK X.

    A COMPARISON OF FIRE INSURANCE COSTS OF WOOD, MASONRY, STEEL AND CONCRETE STRUCTURES SHOWS FIRE INSURANCE PREMIMUMS ON WOOD STRUCTURES TEND TO BE HIGHER THAN PREMIUMS ON MASONRY, STEEL AND CONCRETE BUILDINGS, HOWEVER, THE INITIAL COST OF THE WOOD BUILDINGS IS LOWER. DATA SHOW THAT THE SAVINGS ACHIEVED IN THE INITIAL COST OF WOOD STRUCTURES OFFSET…

  1. The Carbon Impacts of Wood Products

    Science.gov (United States)

    Richard Bergman; Maureen Puettmann; Adam Taylor; Kenneth E. Skog

    2014-01-01

    Wood products have many environmental advantages over nonwood alternatives. Documenting and publicizing these merits helps the future competitiveness of wood when climate change impacts are being considered. The manufacture of wood products requires less fossil fuel than nonwood alternative building materials such as concrete, metals, or plastics. By nature, wood is...

  2. The major birch pollen allergen Bet v 1 induces different responses in dendritic cells of birch pollen allergic and healthy individuals.

    Directory of Open Access Journals (Sweden)

    Ursula Smole

    Full Text Available Dendritic cells play a fundamental role in shaping the immune response to allergens. The events that lead to allergic sensitization or tolerance induction during the interaction of the major birch pollen allergen Bet v 1 and dendritic cells are not very well studied. Here, we analyzed the uptake of Bet v 1 and the cross-reactive celery allergen Api g 1 by immature monocyte-derived dendritic cells (iMoDCs of allergic and normal donors. In addition, we characterized the allergen-triggered intracellular signaling and transcriptional events. Uptake kinetics, competitive binding, and internalization pathways of labeled allergens by iMoDCs were visualized by live-cell imaging. Surface-bound IgE was detected by immunofluorescence microscopy and flow cytometry. Allergen- and IgE-induced gene expression of early growth response genes and Th1 and Th2 related cytokines and chemokines were analyzed by real-time PCR. Phosporylation of signaling kinases was analyzed by Western blot. Internalization of Bet v 1 by iMoDCs of both donor groups, likely by receptor-mediated caveolar endocytosis, followed similar kinetics. Bet v 1 outcompeted Api g 1 in cell surface binding and uptake. MoDCs of allergic and healthy donors displayed surface-bound IgE and showed a pronounced upregulation of Th2 cytokine- and NFκB-dependent genes upon non-specific Fcε receptor cross-linking. In contrast to these IgE-mediated responses, Bet v 1-stimulation increased transcript levels of the Th2 cytokines IL-4 and IL-13 but not of NFκB-related genes in MoDCs of BP allergic donors. Cells of healthy donors were either unresponsive or showed elevated mRNA levels of Th1-promoting chemokines. Moreover, Bet v 1 was able to induce Erk1/2 and p38 MAPK activation in BP allergics but only a slight p38 activation in normal donors. In conclusion, our data indicate that Bet v 1 favors the activation of a Th2 program only in DCs of BP allergic individuals.

  3. Potential wood protection strategies using physiological requirements of wood degrading fungi

    NARCIS (Netherlands)

    Sailer, M.F.; Etten, B.D. van

    2004-01-01

    Due to the increasing restrictions in the use of wood preserving biocides a number of potential biocide free wood preserving alternatives are currently assessed. Wood degrading fungi require certain conditions in the wood in order to be able to use wood as a food source. This paper discusses the

  4. Allergy immunotherapy with a hypoallergenic recombinant birch pollen allergen rBet v 1-FV in a randomized controlled trial.

    Science.gov (United States)

    Klimek, Ludger; Bachert, Claus; Lukat, Karl-Friedrich; Pfaar, Oliver; Meyer, Hanns; Narkus, Annemie

    2015-01-01

    Pollen extracts and chemically modified allergoids are used successfully in allergen immunotherapy (AIT). Recombinant extracts offer potential advantages with respect to pharmaceutical quality, standardization and dosing. A hypoallergenic recombinant folding variant of the major birch pollen allergen (rBet v 1-FV) was compared with an established native birch preparation. A pre-seasonal, randomized, actively controlled phase II study was performed in birch pollen allergic rhino-conjunctivitis with or without asthma, GINA I/ II. 51 patients (24 rBet v 1-FV, 27 native extract) started therapy with subcutaneous allergen immunotherapy (SCIT). Primary end-point was a combined symptom medication score (SMS), changes in nasal provocation test, visual rating score and specific antibody responses secondary end-points. After one pre-seasonal treatment course the combined SMS was 5.86 (median; IQR: 14.02) for the rBet v 1-FV group versus 12.40 (median; IQR: 9.32) for the comparator during the three weeks pollen season (p = 0.330). After treatment in the second year, scores were 3.00 (median; IQR: 6.50) and 2.93 (4.86) respectively. Allergen tolerance in a nasal provocation test improved to a comparable extent in both groups. Significant increases in birch pollen-specific IgG1 and IgG4 were observed in both treatment groups following the first treatment phase and remained significantly raised until the end of the study. In this first in man, proof of concept phase II trial no statistical difference between rBet v 1-FV and an established natural pollen extract could be observed. rBet v 1-FV could be administered in higher doses than the native protein with no increase in adverse effects. The study was registered in clinicalTrials.gov (NCT00266526).

  5. Isolation of suberin from birch outer bark and cork using ionic liquids: A new source of macromonomers

    OpenAIRE

    Ferreira, Rui; Garcia, Helga; Sousa, Andreia F.; Freire, Carmen S. R.; Silvestre, Armando J. D.; Rebelo, Luis Paulo N.; Pereira, Cristina Silva

    2013-01-01

    Cholinium hexanoate, a biocompatible and biodegradable ionic liquid, was recently demonstrated to efficiently and selectively extract suberin domains from cork, combining high extraction efficiency with isolation of a partial depolymerised material. In the present paper, we report a comparative study of the characterisation of suberin extracted from birch outer bark and from cork using cholinium hexanoate. It became apparent that both extracted suberin samples showed still a cross-linked natu...

  6. Features of secondary birch young stands in low mountain Pokuttya (Ukrainian Carpathian mts.

    Directory of Open Access Journals (Sweden)

    S. Y. Milevskaya

    2015-06-01

    Full Text Available Forest landscapes of the region during the last 3–5 centuries undergone the profound anthropogenic transformation. Secondary young stands occupy 25% of the total forest area. The problem of derivatives is particularly relevant for the modern forest typology in the Carpathian region. It requires the reflection in its dynamic trends shaping the stands, especially mixed young stands. The aim of our study consisted in getting the knowledge of the structural features of the secondary phytocoenosis of birch young stands in this area.The object of the study was age class I saplings growing in the mountainous part of Pokuttya, particularly in the basin of the Lutshka River. The conceptual basis of our study is the modern dynamic vision that every forest type is a consecutive series of forest plant communities within each type of homogeneous growing conditions. We apply methods of ecological-floristic research of the Brown-Blanke school in the interpretation of the Polish school phytosociology. However we also take into account both syntaxonomy generalizations of the Ukrainian scientists. The actual material comprises the original geobotanical studies with fixation of the vast majority of species in plant communities. Mainly the species having diagnostic value to separate syntaxons were taken into account in the analytical processing. Young forest stands (with the height of 8–12 m and crown cover of 70% together form the trees Betula pendula and B. pubescens. Fairly numerous admixture is formed by trees Alnus incana; besides, there are Fagus sylvatica, Populus tremula, Quercus robur, Padus avium. For dominants, they can be called “grey-alder birch blackberry sedge bracken fern” – Betula pendula+Alnus incana–Rubus caesius–Carex brizoides+Pteridium aquilinum. It is rich in floristic composition of the plant communities. They contain at least 12 species of trees, 3 species of shrubs, 4 species of bushes and 89 species of herbs. Diagnostic

  7. Impact of ectohumus application in birch and pine nurseries on the presence of soil mites (Acari, Oribatida in particular

    Directory of Open Access Journals (Sweden)

    Klimek Andrzej

    2016-03-01

    Full Text Available Intensively used forest nurseries are characterised by degradation processes that lead to a drop in the quality of seedlings. The main reason of this problem is a decrease in biological soil diversity. Therefore, an attempt of nursery soil enrichment by introducing ectohumus – as compost and fresh litter – from the pine forest was carried out. The research was carried out in 2009–2011 in the Bielawy forest nursery near the city of Toruń, Poland. The objective of the study was to determine the impact of organic fertilisation (compost made up of forest humus and mulching using fresh ectohumus on the density and community composition of Acari mites and on species composition of oribatid mites (Oribatida in the nurseries of silver birch and Scots pine. Mites, especially oribatid mites, were treated as bioindicators of soil biological activity. Research has shown that mulching using fresh ectohumus caused a multiple increase in the density of mites, especially in saprophagous mites Oribatida. Oribatid mites were clearly more numerous in birch cultivation than in that of pine. Overall, 27 species of oribatid mites were found. Mulching resulted in a significant growth in species diversity in both cultivations. The most numerous oribatid mite in the area under the study was Oribatula tibialis. This species was present in all plots and showed clear preference for birch cultivation. Tectocepheus velatus and Oppiella nova, common and known to be present in a variety of environments, were slightly less numerous.

  8. Women's work... in wood products

    Science.gov (United States)

    Janice K. Wiedenbeck

    1998-01-01

    Women have opportunities galore in the 1990s in wood products research, education, extension, consulting,manufacturing, marketing, and associations in North America. In the 1980s the same statement could not have been made.

  9. Slavic Forest, Norwegian Wood (models)

    OpenAIRE

    Rosa, Rudolf; Žabokrtský, Zdeněk; Zeman, Daniel; Mareček, David

    2017-01-01

    Trained models for UDPipe used to produce our final submission to VarDial 2017 shared task (https://bitbucket.org/hy-crossNLP/vardial2017) and described in a paper by the same authors titled Slavic Forest, Norwegian Wood.

  10. Wood and Paper Manufacturing Sectors

    Science.gov (United States)

    Find EPA regulatory information for the wood product and paper manufacturing sectors, including paper, pulp and lumber. Information includes NESHAPs and effluent guidelines for pulp and paper rulemaking, and compliance guidelines

  11. Rethinking wood dust safety standards

    OpenAIRE

    Ratnasingam, Jega; Wai, Lim Tau; Ramasamy, Geetha; Ioras, Florin; Tadin, Ishak; Universiti Putra Malaysia; Buckinghamshire New University; Centre for Occupational Safety and Health Singapore

    2015-01-01

    The current universal work safety and health standards pertaining to wood dust in factories lack the localisation required. As a study has shown, there is a urgent need to reevaluate the current guidelines and practices.

  12. Biodiesel production using heterogeneous catalysts including wood ash and the importance of enhancing byproduct glycerol purity

    International Nuclear Information System (INIS)

    Uprety, Bijaya K.; Chaiwong, Wittavat; Ewelike, Chinomnso; Rakshit, Sudip K.

    2016-01-01

    Highlights: • Comparison of biodiesel production using homogeneous and heterogeneous catalysts. • Comparative study of CaO and CaO supported on alumina for biodiesel production. • Tradeoff between biodiesel conversion rate and purity. • Ash from birch bark and wood pellet industry explored as a potential catalyst. - Abstract: Transesterification of vegetable oils or animal fats with methanol in the presence of catalysts produces fatty acid methyl esters (FAME) and glycerol as a co-product. This study was focused on a comparative study of the transesterification of refined, bleached and deodorized palm oil (RBD palm oil) using a heterogeneous catalysts CaO with and without γ-alumina (γ-Al_2O_3) as a support. The results were also compared to that using sodium hydroxide (NaOH), which is a homogenous catalyst. Parameters like the amount of catalyst, the molar ratio of methanol to oil, reaction time and reaction temperature that affect methyl ester and glycerol formation were analyzed and the optimum conditions were determined. The FAME and glycerol content (96.75% and 92.73% respectively) obtained using CaO were lower in purity compared to that using CaO/Al_2O_3 (97.66% and 96.36% respectively). In the second phase of our work, wood ash from two different sources (birch bark & flyash from a biomass based power plant), which were calcined at 800 °C were studied for their potential use as a cheap renewable alternative heterogeneous catalyst. Both the wood ash samples were found to have good potential for use in such production process, but needs to be optimized further to obtain biodiesel which meets fuel biodiesel specifications. Both CaO and CaO supported on alumina produces FAME to levels that meet the fuel specifications required for blending with diesel. However, the latter produces a purer form of byproduct glycerol that can be easily converted to value added products, without the need for purification. On this basis the supported catalyst is

  13. Use of woods at continual phytoextraction

    International Nuclear Information System (INIS)

    Maruskova, A.

    2007-01-01

    Phytoextraction that used natural hyper-accumulators for cleaning polluted soil has more advantages than induced phytoextraction. After all, using the tree species as hypo-accumulators is very rarely. This paper notes about few characteristics of tree species, especially birch (Betula pendula), which should encourage the research and next, their using in the process of phytoextraction. (author)

  14. Life cycle environmental impacts of different construction wood waste and wood packaging waste processing methods

    OpenAIRE

    Manninen, Kaisa; Judl, Jáchym; Myllymaa, Tuuli

    2016-01-01

    This study compared the life cycle environmental impacts of different wood waste processing methods in three impact categories: climate impact, acidification impacts and eutrophication impacts. The wood waste recovery methods examined were the use of wood waste in terrace boards made out of wood composite which replace impregnated terrace boards, incineration of wood waste in a multi-fuel boiler instead of peat and the use of wood waste in the production of particleboard in either Finland or ...

  15. Occurrence patterns of dead wood and wood-dependent lichens in managed boreal forest landscapes

    OpenAIRE

    Svensson, Måns

    2013-01-01

    Dead wood is a key resource for biodiversity, on which thousands of forest organisms are dependent. Because of current forest management, there has been a large-scale change in dead wood amounts and qualities, and consequently, many wood-dependent species are threatened. The general aim of this thesis is to increase our understanding of habitat requirements and occurrence patterns of wood-dependent lichens in managed, boreal forest landscapes. We surveyed dead wood and wood-dependent lichens ...

  16. Simulation of water-surface elevations for a hypothetical 100-year peak flow in Birch Creek at the Idaho National Engineering and Environmental Laboratory, Idaho

    International Nuclear Information System (INIS)

    Berenbrock, C.; Kjelstrom, L.C.

    1997-01-01

    Delineation of areas at the Idaho National Engineering and Environmental Laboratory that would be inundated by a 100-year peak flow in Birch Creek is needed by the US Department of Energy to fulfill flood-plain regulatory requirements. Birch Creek flows southward about 40 miles through an alluvium-filled valley onto the northern part of the Idaho National Engineering and Environmental laboratory site on the eastern Snake River Plain. The lower 10-mile reach of Birch Creek that ends in Birch Creek Playa near several Idaho National Engineering and Environmental Laboratory facilities is of particular concern. Twenty-six channel cross sections were surveyed to develop and apply a hydraulic model to simulate water-surface elevations for a hypothetical 100-year peak flow in Birch Creek. Model simulation of the 100-year peak flow (700 cubic feet per second) in reaches upstream from State Highway 22 indicated that flow was confined within channels even when all flow was routed to one channel. Where the highway crosses Birch Creek, about 315 cubic feet per second of water was estimated to move downstream--115 cubic feet per second through a culvert and 200 cubic feet per second over the highway. Simulated water-surface elevation at this crossing was 0.8 foot higher than the elevation of the highway. The remaining 385 cubic feet per second flowed southwestward in a trench along the north side of the highway. Flow also was simulated with the culvert removed. The exact location of flood boundaries on Birch Creek could not be determined because of the highly braided channel and the many anthropogenic features (such as the trench, highway, and diversion channels) in the study area that affect flood hydraulics and flow. Because flood boundaries could not be located exactly, only a generalized flood-prone map was developed

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

    Science.gov (United States)

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

    1987-01-01

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

  18. Robert Williams Wood: pioneer of invisible light.

    Science.gov (United States)

    Sharma, Shruti; Sharma, Amit

    2016-03-01

    The Wood's lamp aids in the diagnosis of multiple infectious, inflammatory and neoplastic dermatologic conditions. Although the Wood's lamp has many applications, which have improved both the diagnosis and management of disease, the man credited for its invention is relatively unknown in medicine. Robert Williams Wood, a prominent physicist of the early 20th century, is credited for the invention of the Wood's lamp. Wood was the father of infrared and ultraviolet photography and made significant contributions to other areas in optics and spectroscopy. Wood's work encompassed the formative years of American Physics; he published over 200 original papers over his lifetime. A few years after the invention of the Wood's lamp for ultraviolet photography, physicians in Europe adopted the Wood's lamp for dermatologic applications. Wood's lamp remains popular in clinics globally, given its ease of use and ability to improve diagnostic precision. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Reactivity and burnout of wood fuels

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo

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

  20. Acoustic and adsorption properties of submerged wood

    Science.gov (United States)

    Hilde, Calvin Patrick

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

  1. Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes.

    Science.gov (United States)

    Teeravivattanakit, Thitiporn; Baramee, Sirilak; Phitsuwan, Paripok; Sornyotha, Somphit; Waeonukul, Rattiya; Pason, Patthra; Tachaapaikoon, Chakrit; Poomputsa, Kanokwan; Kosugi, Akihiko; Sakka, Kazuo; Ratanakhanokchai, Khanok

    2017-11-15

    Complete utilization of carbohydrate fractions is one of the prerequisites for obtaining economically favorable lignocellulosic biomass conversion. This study shows that xylan in untreated rice straw was saccharified to xylose in one step without chemical pretreatment, yielding 58.2% of the theoretically maximum value by Paenibacillus curdlanolyticus B-6 PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase. Moreover, xylose yield from untreated rice straw was enhanced to 78.9% by adding endoxylanases PcXyn10C and PcXyn11A from the same bacterium, resulting in improvement of cellulose accessibility to cellulolytic enzyme. After autoclaving the xylanolytic enzyme-treated rice straw, it was subjected to subsequent saccharification by a combination of the Clostridium thermocellum endoglucanase CtCel9R and Thermoanaerobacter brockii β-glucosidase TbCglT, yielding 88.5% of the maximum glucose yield, which was higher than the glucose yield obtained from ammonia-treated rice straw saccharification (59.6%). Moreover, this work presents a new environment-friendly xylanolytic enzyme pretreatment for beneficial hydrolysis of xylan in various agricultural residues, such as rice straw and corn hull. It not only could improve cellulose saccharification but also produced xylose, leading to an improvement of the overall fermentable sugar yields without chemical pretreatment. IMPORTANCE Ongoing research is focused on improving "green" pretreatment technologies in order to reduce energy demands and environmental impact and to develop an economically feasible biorefinery. The present study showed that PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase from P. curdlanolyticus B-6, was capable of conversion of xylan in lignocellulosic biomass such as untreated rice straw to xylose in one step without chemical pretreatment. It

  2. Two-dimensional NMR evidence for cleavage of lignin and xylan substituents in wheat straw through hydrothermal pretreatment and enzymatic hydrolysis

    DEFF Research Database (Denmark)

    Yelle, Daniel J.; Kaparaju, Laxmi-Narasimha Prasad; Hunt, Christopher G.

    2013-01-01

    correlation spectroscopy, via an heteronuclear single quantum coherence experiment, revealed substantial lignin β-aryl ether cleavage, deacetylation via cleavage of the natural acetates at the 2-O- and 3-O-positions of xylan, and uronic acid depletion via cleavage of the (1 → 2)-linked 4-O....... g., further deacylation revealed by the depletion in ferulate and p-coumarate structures). Supplementary chemical analyses showed that the hydrothermal pretreatment increased the cellulose and lignin concentration with partial removal of extractives and hemicelluloses. The subsequent enzymatic...

  3. Partial debarking of energy wood stems in production of high quality fuel chips and fuel logs (DryMe); Runkopuun osittainen kuorinta metsaehakkeen ja pilkkeidentuotantoketjussa (DryMe) - PUUT58

    Energy Technology Data Exchange (ETDEWEB)

    Sikanen, L.; Roeser, D.; Tahvanainen, T.; Prinz, R. [Finnish Forest Research Institute, Joensuu (Finland); Erkkilae, A.; Heikkinen, A.; Hillebrand, K. [VTT Technical Research Centre of Finland, Jyvaeskylae (Finland)

    2007-07-01

    Small wood chip fueled heating plants require high quality chips in order to achieve low service need and problem free running. Low moisture content is considered to be the most important quality factor in wood based fuels. On the other hand, drying should be efficient and handy as a part of supply chain. Rapidly growing small-scale wood energy business needs new methods to ensure availability of high quality fuel. Partial debarking of both boreal broadleaved and coniferous species is known as effective method to dry timber during storing. Anyhow, proper place for storing and convenient weather conditions are needed. Partly debarked stems could be also the raw material for wood pellets. In Finnish studies, for example, storing over one summer took moisture content down from 40% to 27% with partly debarked birch logs. Some preliminary tests have been made also in Scotland and England with baled residues and small diameter logs without debarking. Even British climate seems to be suitable for natural drying of logs. In Central Europe, natural drying is crucial in order to achieve high quality of forest chips for heating. The aims of the DryMe-project are: (1) Remodify and study harvester head which is capable to debark energy wood stems. The aim is to create modified feeding rolls and delimbing knives or extra debarking device, which remove effectively 30-50% of bark during normal harvesting work. The success of debarking will be tested by field experiments and drying trials. Method should work with Silver Birch, Scots Pine and Lodgepole Pine. (2) Test different kinds of bark scarifying patterns and methods according to their capability to evaporate water out from the logs in natural drying. (orig.)

  4. wood burns down

    Directory of Open Access Journals (Sweden)

    Vladimir Bukh

    2004-11-01

    Full Text Available To relax the local authorities and to receive the guests of high rank «with no tie» the so-called «Fisherman's House» was built at the source of Angara-river, near Lake Baikal. Vladimir Ivanov, a young architect, was noticed by his skillful performa nee of exclusive orders and became the author of this house. At the time of ferroconcrete boom the proposal to build a wooden guest house turned out to be unexpectedly to the point and was graciously approved. The economic department was entrusted to select the men good for carpenter's work, and the forestry department was entrusted to provide thick round timber. And the work started. But, as it usually happens, the workers did not take the trouble and made the first eight rims of the current timber with an inappropriate diameter.And when Pavlov insisted on demolishing the construction and replacing the logs by the logs with the necessary diameter, the building work obeyed to his will and was finished suecessfully.The architecture of the house is not the derived action of the saw and the fret-saw. It is a technology of the axe. It is natural, convincing and original. It is no use to look for the local sources in it. It grew up in the area of timber and cold winter. And this clear and efficient action kept the construction from the annoying vulgarity and provided Siberian exotics easily penetrating into one's soul, refined as it may be.One of the eminent guests said with admiration: «Even if Pavlov had created nothing more, he would have justified his professional choice with this single house.» Why not to say it as a good toast. However, this is a suitable case to add: style is an absence of style. It is a taste.After the Fisherman's House Irkutsk architects were attracted by wood. They followed the strictness in wood and, as much as they could, created a couple of successful remakes, until the cylinder logs and ... new

  5. Refraction and absorption of microwaves in wood

    International Nuclear Information System (INIS)

    Ziherl, Saša; Bajc, Jurij; Čepič, Mojca

    2013-01-01

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

  6. Sugar yields from dilute oxalic acid pretreatment of maple wood compared to those with other dilute acids and hot water.

    Science.gov (United States)

    Zhang, Taiying; Kumar, Rajeev; Wyman, Charles E

    2013-01-30

    Dilute oxalic acid pretreatment was applied to maple wood to improve compatibility with downstream operations, and its performance in pretreatment and subsequent enzymatic hydrolysis was compared to results for hydrothermal and dilute hydrochloric and sulfuric acid pretreatments. The highest total xylose yield of ∼84% of the theoretical maximum was for both 0.5% oxalic and sulfuric acid pretreatment at 160 °C, compared to ∼81% yield for hydrothermal pretreatment at 200 °C and for 0.5% hydrochloric acid pretreatment at 140 °C. The xylooligomer fraction from dilute oxalic acid pretreatment was only 6.3% of the total xylose in solution, similar to results with dilute hydrochloric and sulfuric acids but much lower than the ∼70% value for hydrothermal pretreatment. Combining any of the four pretreatments with enzymatic hydrolysis with 60 FPU cellulase/g of glucan plus xylan in the pretreated maple wood resulted in virtually the same total glucose plus xylose yields of ∼85% of the maximum possible. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    Science.gov (United States)

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. © 2013 John Wiley & Sons Ltd.

  8. Water relations in silver birch during springtime: How is sap pressurised?

    Science.gov (United States)

    Hölttä, T; Dominguez Carrasco, M D R; Salmon, Y; Aalto, J; Vanhatalo, A; Bäck, J; Lintunen, A

    2018-05-06

    Positive sap pressures are produced in the xylem of birch trees in boreal conditions during the time between the thawing of the soil and bud break. During this period, xylem embolisms accumulated during wintertime are refilled with water. The mechanism for xylem sap pressurization and its environmental drivers are not well known. We measured xylem sap flow, xylem sap pressure, xylem sap osmotic concentration, xylem and whole stem diameter changes, and stem and root non-structural carbohydrate concentrations, along with meteorological conditions at two sites in Finland during and after the sap pressurisation period. The diurnal dynamics of xylem sap pressure and sap flow during the sap pressurisation period varied, but were more often opposite to the diurnal pattern after bud burst, i.e. sap pressure increased and sap flow rate mostly decreased when temperature increased. Net conversion of soluble sugars to starch in the stem and roots occurred during the sap pressurisation period. Xylem sap osmotic pressure was small in comparison to total sap pressure, and it did not follow changes in environmental conditions or tree water relations. Based on these findings, we suggest that xylem sap pressurisation and embolism refilling occur gradually over a few weeks through water transfer from parenchyma cells to xylem vessels during daytime, and then the parenchyma are refilled mostly during nighttime by water uptake from soil. Possible drivers for water transfer from parenchyma cells to vessels are discussed. Also the functioning of thermal dissipation probes in conditions of changing stem water content is discussed. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  9. The effect of rabbit age on in vitro caecal fermentation of starch, pectin, xylan, cellulose, compound feed and its fibre.

    Science.gov (United States)

    Lavrenčič, A

    2007-03-01

    In vitro gas production kinetics of six different substrates, pectin (PEC), xylan (XYL), starch (STA), cellulose (CEL), commercial compound feed (FEED; 201 g crude protein per kg, 155 g crude fibre per kg, 334 g neutral-detergent fibre (NDF) per kg and 190 g acid-detergent fibre (ADF) per kg) and an NDF prepared from commercial compound feed (NDFFEED) were determined using the caecum contents of weaned rabbits (36 days of age) and of rabbits at slaughter age (78 days of age) as inoculums. The cumulated gas production over 96 h of incubation was modelled with Gompertz model, and the kinetic parameters compared. The total potential gas production (parameter 'B' of the Gompertz model) was not affected (P>0.05) by the inoculum source, except with STA, where rabbits at slaughter weight had significantly higher total potential fermentability (314 ml/g dry matter (DM)) than those at weaning age (189 ml/g DM). Intensities of fermentation (maximum fermentation rate; MFR) of PEC (32.2 ml/h) and XYL (24.4 ml/h) were significantly greater in rabbits at weaning, while that of STA (45 ml/h) was significantly lower than at slaughter age (23.0, 14.3 and 14.0 ml/h for PEC, XYL and STA, respectively). The MFRs of CEL and NDFFEED were very similar between inoculum sources. In the first 10 h of fermentation which correspond to the normal retention time of the substrates in the caecum, the highest amount of gas was produced from PEC, followed by FEED and XYL. These substrates had a time of maximum fermentation rate (TMFR) at both rabbit ages short enough (8.0 and 9.5 h for PEC, 9.5 and 6.6 h for FEED, 13.7 and 14.2 h for XYL at weaning and at slaughter age, respectively) to be almost completely fermented in vivo.

  10. Liquefaction of aspen poplar wood

    Energy Technology Data Exchange (ETDEWEB)

    Eager, R L; Mathews, J F; Pepper, J M

    1982-01-01

    Dried and green aspen poplar wood suspended in water containing alkali catalysts was converted completely to an oil, water-soluble chemical, and gases by heating for 1 hour in the presence of CO in a rocking batch reactor. Within the ranges of parameters studied: temperature of 593-633 K; nominal reaction times of less than or equal to 1 hour; water-to-wood ratio of 0.5:1-5:1; Na/sub 2/CO/sub 3/, K/sub 2/CO/sub 3/, and NaOH catalysts; amount of catalyst 7.0-12.5%; and initial H-CO ratios of 2:1-0:1, the water-to-wood ratio was most important. Oil yields of approximately 50% with a C plus H content of approximately 80% and representing a C recovery of approximately 66% were obtained. The higher heats of combustion were 32.2-36.0 MJ/kg.

  11. Thermopower of beech wood biocarbon

    Science.gov (United States)

    Smirnov, I. A.; Smirnov, B. I.; Orlova, T. S.; Sulkovski, Cz.; Misiorek, H.; Jezowski, A.; Muha, J.

    2011-11-01

    This paper reports on measurements of the thermopower S of high-porosity samples of beech wood biocarbon with micron-sized sap pores aligned with the tree growth direction. The measurements have been performed in the temperature range 5-300 K. The samples have been fabricated by pyrolysis of beech wood in an argon flow at different carbonization temperatures ( T carb). The thermopower S has been measured both along and across the sap pores, thus offering a possibility of assessing its anisotropy. The curves S( T carb) have revealed a noticeable increase of S for T carb biocarbons, which suggests that for T carb ˜ 1000°C they undergo a phase transition of the insulator-(at T carb 1000°C) type. The existence of this transition is attested also by the character of the temperature dependences S( T) of beech wood biocarbon samples prepared at T carb above and below 1000°C.

  12. Wood-burning stoves worldwide

    DEFF Research Database (Denmark)

    Luis Teles de Carvalho, Ricardo

    global environmental health risk, since these sources are important contributors to fine particulate matter (PM2.5) in the ambient air that increase climate and health risks. This thesis explores the social-technical dimensions of both the use of wood-burning stoves (WBSs) and transition to the use......More than any time in our history, the wood-burning stove continues to be the most popular technology used for cooking and heating worldwide. According to the World Health Organization and recent scientific studies, the inefficient use of solid-fuels in traditional stoves constitutes the major...... systems, improved efficient retrofits and advanced stove innovations. In chapter 3, four popular wood-burning practices found in five countries were singled-out to be examined closely in four case studies: “cooking in Brazil”, “cooking and heating in Peru”, “heating in Portugal” and “recreational heat...

  13. Disinfection of foot-and-mouth disease and African swine fever viruses with citric acid and sodium hypochlorite on birch wood carriers

    Science.gov (United States)

    Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contam...

  14. Assessment of the wood waste resource and its position in the wood / wood-energy sector - Synthesis

    International Nuclear Information System (INIS)

    Guinard, Ludovic; Deroubaix, Gerard; Roux, Marie-Lise; Levet, Anne-Laure; Quint, Vincent

    2015-04-01

    The first objective of this study is to obtain a better knowledge of the 'wood wastes' issue, to propose a photography of the wood waste sector (productions, trades, consumptions), and then to elaborate different prospective scenarios on the use of wood waste volumes while taking into account possible evolutions on the medium or short term of the regulation and market of the wood/wood energy sector. The considered wastes come from industrial production, from the use of wood-based products, and from the end of life of products potentially containing wood. The authors present bibliographical sources and the adopted methodology, briefly describe the 'wood waste' system with its actors, and then report their assessment of wood wastes. They propose a global assessment as well as detailed assessments with respect to waste origins: wood trade and distribution, industries, craft, households and communities, building sector, public and private tertiary sector, packaging. They also address the collection and management of wood wastes by public services, and present the different types of valorisation (panel fabrication, energy, and others). They discuss exports, and then present different scenarios: a trend-based scenario, and two prospective scenarios with a priority to energetic valorisation or to material valorisation of wood wastes. These scenarios are compared

  15. Enhanced Agarose and Xylan Degradation for Production of Polyhydroxyalkanoates by Co-Culture of Marine Bacterium, Saccharophagus degradans and Its Contaminant, Bacillus cereus

    Directory of Open Access Journals (Sweden)

    Shailesh S. Sawant

    2017-02-01

    Full Text Available Over reliance on energy or petroleum products has raised concerns both in regards to the depletion of their associated natural resources as well as their increasing costs. Bioplastics derived from microbes are emerging as promising alternatives to fossil fuel derived petroleum plastics. The development of a simple and eco-friendly strategy for bioplastic production with high productivity and yield, which is produced in a cost effective manner utilising abundantly available renewable carbon sources, would have the potential to result in an inexhaustible global energy source. Here we report the biosynthesis of bioplastic polyhydroxyalkanoates (PHAs in pure cultures of marine bacterium, Saccharophagus degradans 2-40 (Sde 2-40, its contaminant, Bacillus cereus, and a co-culture of these bacteria (Sde 2-40 and B. cereus degrading plant and algae derived complex polysaccharides. Sde 2-40 degraded the complex polysaccharides agarose and xylan as sole carbon sources for biosynthesis of PHAs. The ability of Sde 2-40 to degrade agarose increased after co-culturing with B. cereus. The association of Sde 2-40 with B. cereus resulted in increased cell growth and higher PHA production (34.5% of dry cell weight from xylan as a carbon source in comparison to Sde 2-40 alone (22.7% of dry cell weight. The present study offers an innovative prototype for production of PHA through consolidated bioprocessing of complex carbon sources by pure and co-culture of microorganisms.

  16. Effect of degradation of xylan constituent in Mitsumata (Edgeworthia papyrifera Sieb. et Zucc. ) bast on its pulping by pectinolytic enzymes form Erwinia carotovora

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Hiroyuki; Matsuo, Ryukichi; Kobayashi, Yoshinari

    1988-01-01

    Pulping of mitsumata (Edgeworthia papyrifera Sieb. et Zucc.) bast by the crude enzyme from a bacterium Erwinia carotovora FERM P-7576, was more effective by a stepwise treatment at pH 6.5 and subsequently at pH 9.5 and eluted greater amount of xylose constituent than a constant pH treatment at pH 9.5 where only the maceration enzymes, endo-pectate lyase and endo-pectin lyase, among the crude enzyme are operative. The crude enzymes obtained from the cultivation of this bacterial strain on mitsumata bast fibers were more effective for the stepwise pH pulping method than those from the cultivation on soluble pectin. Xylanase activity in the mitsumata bast-induced enzyme at pH 6.5 was twice as high as that in the soluble pectin-induced one. The activities of other hemicellulases and cellulase were, high as that in the soluble pectin-induced one. The activities of other hemicellulases and cellulase were, however, independent on the inducing materials. Purified exo-type xylanase prepared from the crude enzyme acted comparably to the entire crude enzyme in the first step of the combination pulping, but the xylanase per se showed no maceration activity. These results suggests that the degradation of xylan constituent within the bast fibers effects the acceleration of the subsequent enzymatic pulping by the pectinolytic maceration enzymes. The maceration mechanism involving xylan degradation was also discussed.

  17. Production of furfural from xylose, xylan and corncob in gamma-valerolactone using FeCl3·6H2O as catalyst.

    Science.gov (United States)

    Zhang, Luxin; Yu, Hongbing; Wang, Pan; Li, Yong

    2014-01-01

    An efficient and simple one-pot monophasic reaction system with small carbon footprint for converting xylose, xylan and corncob into furfural was developed in gamma-valerolactone (GVL, an ideal sustainable solvent derived from lignocelluloses) by using FeCl3·6H2O as catalyst. Good yields of furfural from xylose were obtained, and the system was shown to work for xylan and corncob as well. A surprisingly high furfural yield of 79.6% from untreated corncob was achieved at 458 K for 100 min. Contrary to what was generally believed, the addition of water, reduced the rate of the reactions, but showed positive effect on preventing the furfural from degradation in GVL. Besides, the C6 sugars (glucose and cellulose) afforded 11.4-24.5% furfural yields when employing this catalytic approach. The reaction system proposed in this manuscript showed great potential for optimizing the catalytic process in furfural production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Effects of the cellulose, xylan and lignin constituents on biomass pyrolysis characteristics and bio-oil composition using the Simplex Lattice Mixture Design method

    International Nuclear Information System (INIS)

    Fan, Yongsheng; Cai, Yixi; Li, Xiaohua; Jiao, Lihua; Xia, Jisheng; Deng, Xiuli

    2017-01-01

    Highlights: • Simplex Lattice Mixture Design was firstly applied to study biomass pyrolysis process. • Interactions between the constituents had effects on the biomass pyrolysis behavior. • Biomass pyrolysis behavior can be predicted based on the ratios of three constituents. • Bio-oil composition was affected by the constituents and their pyrolysis products. - Abstract: In order to clarify the relationships between biomass pyrolysis mechanism and its main constituents. The effects of main constituents on biomass pyrolysis characteristics were firstly determined by thermo-gravimetric analysis based on the Simplex Lattice Mixture Design to investigate that whether the prediction of the pyrolysis behavior of a certain lignocellulosic biomass is possible when its main constituent contents are known. The results showed that there are constituent interactions in the pyrolysis process, which can be intuitively reflected through the change laws of kinetics parameters. The mathematical models for calculating kinetics values were established, and the models were proved to be valid for predicting lignocellulosic biomass pyrolysis behavior. In addition, the effects of biomass constituents on bio-oil compositions were explored by subsequent vacuum pyrolysis experiments. The xylan pyrolysis had a certain inhibitory effect on the pyrolysis of cellulose, and the pyrolysis products of lignin might promote the further decomposition of sugars from cellulose pyrolysis, while the interaction between xylan and lignin had a little effect on the bio-oil composition.

  19. Perinatal maternal administration of Lactobacillus paracasei NCC 2461 prevents allergic inflammation in a mouse model of birch pollen allergy.

    Directory of Open Access Journals (Sweden)

    Irma Schabussova

    Full Text Available BACKGROUND: The hygiene hypothesis implies that microbial agents including probiotic bacteria may modulate foetal/neonatal immune programming and hence offer effective strategies for primary allergy prevention; however their mechanisms of action are poorly understood. We investigated whether oral administration of Lactobacillus paracasei NCC 2461 to mothers during gestation/lactation can protect against airway inflammation in offspring in a mouse model of birch pollen allergy, and examined the immune mechanisms involved. METHODS: BALB/c mice were treated daily with L. paracasei in drinking water or drinking water alone in the last week of gestation and during lactation. Their offspring were sensitized with recombinant Bet v 1, followed by aerosol challenge with birch pollen extract. RESULTS: Maternal exposure to L. paracasei prevented the development of airway inflammation in offspring, as demonstrated by attenuation of eosinophil influx in the lungs; reduction of IL-5 levels in bronchoalveolar lavage, and in lung and mediastinal lymph node cell cultures; and reduced peribronchial inflammatory infiltrate and mucus hypersecretion. While allergen-specific IgE and IgG antibody levels remained unchanged by the treatment, IL-4 and IL-5 production in spleen cell cultures were significantly reduced upon allergen stimulation in offspring of L. paracasei treated mice. Offspring of L. paracasei supplemented mothers had significantly reduced Bet v 1-specific as well as Concanavalin A-induced responses in spleen and mesenteric lymph node cell cultures, suggesting the modulation of both antigen-specific and mitogen-induced immune responses in offspring. These effects were associated with increased Foxp3 mRNA expression in the lungs and increased TGF-beta in serum. CONCLUSION: Our data show that in a mouse model of birch pollen allergy, perinatal administration of L. paracasei NCC 2461 to pregnant/lactating mothers protects against the development of airway

  20. Wood Protection Research Council: Research Priorities 2013

    Science.gov (United States)

    Carol A Clausen; Frederick Green III; Grant T. Kirker; Stan T. Lebow

    2014-01-01

    This report summarizes presentations and comments from the inaugural Wood Protection Research Council meeting. Research needs for the wood protection industry were identified and prioritized. Methods for successfully addressing research needs were discussed by industry, academia, and association representatives.

  1. Wood: a construction material for tall buildings

    Science.gov (United States)

    Wimmers, Guido

    2017-12-01

    Wood has great potential as a building material, because it is strong and lightweight, environmentally friendly and can be used in prefabricated buildings. However, only changes in building codes will make wood competitive with steel and concrete.

  2. Three Construction Projects with Wood Scraps

    Science.gov (United States)

    Levine, Elizabeth

    1977-01-01

    Wood, a natural material, appeals to children of all ages. Wood construction allows children the flexibility of moving parts of their work around until they are satisfied with the arrangement. Three projects are described. (Author/RK)

  3. The environmental assessment of the wood combustion

    International Nuclear Information System (INIS)

    Dinca, Cristian; Badea, Adrian; Apostol, Tiberiu

    2007-01-01

    In this paper, the authors analysed the emissions from residential boilers burning wood logs, bark pellets, wood briquettes and wood pellets. Three boilers, selected with respect to age, design, connection to heat storage tank, and type of biofuel, were included in the study. The emissions captured comprised carbon monoxide (CO), carbon dioxide (CO 2 ), oxygen (O 2 ), total organic carbons (TOC), nitrogen oxides (NO x ), polycyclic aromatic hydrocarbons (PAC) and 33 volatile organic compounds (VOC). We have used the Life Cycle Inventory method in order to identify the main stressors generated by the wood combustion stage. In this purpose, we have analysed one type of old boiler, one type of modern boiler and a multi-fuel boiler, which can burn wood logs, bark pellets, wood briquettes and wood pellets. In this article, we selected only the wood combustion stage because it is the most important according to the emissions produced. (authors)

  4. Photodegradation of wood and depth profile analysis

    International Nuclear Information System (INIS)

    Kataoka, Y.

    2008-01-01

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

  5. Ergonomics and safety in secondary wood processing

    Science.gov (United States)

    Rado Gazo; James D. McGlothlin; Yuehwern, Wiedenbeck, Jan Yih; Yuehwern Yih

    2002-01-01

    The main goal of the project was to initiate a pilot program in ergonomics for the secondary wood products industry. Case studies were conducted at three Midwest secondary wood product companies in 2000 and 2001.

  6. Forest industry wood fuel supply

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The potential for wood fired energy production in the UK is significant. Large scale developments are currently underway which could utilise over 100,000 green tonnes of forest residues. The fuel supply chain is likely to be complicated and there are perceived risks in its organisation and security. This report sets out to address some of these perceived risks and suggest suitable measures to reduce it. Six areas of the fuel supply chain have been studied, namely; Extraction, Comminution, Transport, Assessment and payment of wood fuel; Environmental impact; Nutrient recycling (ash disposal). (author)

  7. Fuel wood symposium; Symposium Energieholz

    Energy Technology Data Exchange (ETDEWEB)

    Wild, C.; Wauer, A. (comps.)

    2001-07-01

    The Bavarian State Institute of Forestry (LWF) organised a 'Fuel Wood Symposium' in Freising-Weihenstephan on 17.11.2000. The purpose of this specialist conference was to give an overview of the use of biomass, especially wood, as an source of energy. (orig.) [German] Die Bayerische Landesanstalt fuer Wald und Forstwirtschaft richtete am 17.11.2000 in Freising-Weihenstephan das 'Symposium Energieholz' aus. Ziel der Fachtagung war es, einen Ueberblick ueber die energetische Nutzung von Biomasse, insbesondere Holz, zu geben. (orig.)

  8. Wood fuelled boiler operating costs

    International Nuclear Information System (INIS)

    Sandars, D.L.

    1995-01-01

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

  9. Preparation of coloured wood plastics

    International Nuclear Information System (INIS)

    Lebedev, V.T.; Filippova, T.G.; Rajchuk, F.Z.

    1977-01-01

    A study has been made into the possibility of using fat, as well as alcohol- and water-soluble dyes for radiation-chemical dying of polymers and plastics filled with wood. The use of fat-soluble azo and anthraquinone dyes permits obtaining intensely colored wood-plastic materials based on methyl methacrylate by way of gamma radiation with doses of up to 3 Mrad. At a dose above 5 Mrad, a marked tarnishing of the dye or a change in color and stains are observed. Dyes in styrene withstand higher radiation doses without any significant destruction

  10. Wood pellets for stoker burner

    International Nuclear Information System (INIS)

    Nykaenen, S.

    2000-01-01

    The author of this article has had a stoker for several years. Wood chips and sod peat has been used as fuels in the stoker, either separately or mixed. Last winter there occurred problems with the sod peat due to poor quality. Wood pellets, delivered by Vapo Oy were tested in the stoker. The price of the pellets seemed to be a little high 400 FIM/500 kg large sack. If the sack is returned in good condition 50 FIM deposit will be repaid to the customer. However, Vapo Oy informed that the calorific value of wood pellets is three times higher than that of sod peat so it should not be more expensive than sod peat. When testing the wood pellets in the stoker, the silo of the stoker was filled with wood pellets. The adjustments were first left to position used for sod peat. However, after the fire had ignited well, the adjustments had to be decreased. The content of the silo was combusted totally. The combustion of the content of the 400 litter silo took 4 days and 22 hours. Respectively combustion of 400 l silo of good quality sod peat took 2 days. The water temperature with wood pellets remained at 80 deg C, while with sod peat it dropped to 70 deg C. The main disadvantage of peat with small loads is the unhomogenous composition of the peat. The results of this test showed that wood pellets will give better efficiency than peat, especially when using small burner heads. The utilization of them is easier, and the amount of ash formed in combustion is significantly smaller than with peat. Wood pellets are always homogenous and dry if you do not spoil it with unproper storage. Pellets do not require large storages, the storage volume needed being less than a half of the volume needed for sod peat. When using large sacks the amount needed can even be transported at the trunk of a passenger car. Depending on the area to be heated, a large sack is sufficient for heating for 2-3 weeks. Filling of stoker every 2-5 day is not an enormous task

  11. Wood preservatives and pressure-treated wood: considerations for historic-preservation projects

    Science.gov (United States)

    Ronald W. Anthony; Stan T. Lebow

    2015-01-01

    Wood, an abundant resource throughout most of the world, has been used as a building material for thousands of years. Many historic buildings have been built primarily of wood, and masonry and stone buildings generally have wood elements, both structural and architectural. As a biological material, wood is both remarkably complex and yet quite durable if well...

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

    Science.gov (United States)

    Eastern Kentucky Univ., Richmond.

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

  13. Composite structure of wood cells in petrified wood

    International Nuclear Information System (INIS)

    Nowak, Jakub; Florek, Marek; Kwiatek, Wojciech; Lekki, Janusz; Chevallier, Pierre; Zieba, Emil; Mestres, Narcis; Dutkiewicz, E.M.; Kuczumow, Andrzej

    2005-01-01

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, μ-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of μ-Raman and μ-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested

  14. Composite structure of wood cells in petrified wood

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, Jakub [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Florek, Marek [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Kwiatek, Wojciech [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Lekki, Janusz [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Chevallier, Pierre [LPS, CEN Saclay et LURE, Universite Paris-Sud, Bat 209D, F-91405 Orsay (France); Zieba, Emil [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland); Mestres, Narcis [Institut de Ciencia de Materials de Barcelona (ICMAB), Campus de la UAB, E-08193-Bellaterra (Spain); Dutkiewicz, E.M. [Institute of Nuclear Physics, Department of Nuclear Spectroscopy, 31-342 Cracow (Poland); Kuczumow, Andrzej [Department of Chemistry, Catholic University of Lublin, 20-718 Lublin (Poland)

    2005-04-28

    Special kinds of petrified wood of complex structure were investigated. All the samples were composed of at least two different inorganic substances. The original cell structure was preserved in each case. The remnants of the original biological material were detected in some locations, especially in the cell walls. The complex inorganic structure was superimposed on the remnant organic network. The first inorganic component was located in the lumena (l.) of the cells while another one in the walls (w.) of the cells. The investigated arrangements were as follows: calcite (l.)-goethite-hematite (w.)-wood from Dunarobba, Italy; pyrite (l.)-calcite (w.)-wood from Lukow, Poland; goethite (l.)-silica (w.)-wood from Kwaczala, Poland. The inorganic composition was analysed and spatially located by the use of three spectral methods: electron microprobe, X-ray synchrotron-based microprobe, {mu}-PIXE microprobe. The accurate mappings presenting 2D distribution of the chemical species were presented for each case. Trace elements were detected and correlated with the distribution of the main elements. In addition, the identification of phases was done by the use of {mu}-Raman and {mu}-XRD techniques for selected and representative points. The possible mechanisms of the described arrangements are considered. The potential synthesis of similar structures and their possible applications are suggested.

  15. Determination of the suitability of chips from selected hardwoods for the production of furfural and charcoal. [Birches, beeches, oaks, alders

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowski, Z

    1979-01-01

    Debarked, cut beech, birch, alder, and oak residues from forestry and woodworking operations contain 16.56-19.73% pentosans and as such can be used for hydrolysis to furfural (I). The hydrolytic residue (mostly lignocellulose) can be carbonized at 400 degrees to charcoal. The hydrolysis is carried out continuously with steam at 250-300 degrees and 1.18 MPa. The residue chips are first soaked in water at 90 degrees for 4 hours and then fed into the hydrolyzer countercurrently to the steam. The yields of I are 5-6% and the yields of charcoal are approximately 20% on the chip weight.

  16. Selected mechanical properties of modified beech wood

    Directory of Open Access Journals (Sweden)

    Jiří Holan

    2008-01-01

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

  17. Comparative toxic effects of some xenobiotics on the germination and early seedling growth of jack pine (Pinus banksiana Lamb. ) and white birch (Betula papyrifera Marsh. )

    Energy Technology Data Exchange (ETDEWEB)

    Weinberger, P; Vladut, R

    1981-12-01

    Seeds of jack pine (Pinus banksiana Lamb.) and white birch (Betula papyrifera Marsh.) were germinated in homogeneous emulsions or aqueous tank-mix solutions of fenitrothion or Matacil and their respective adjuvants: Atlox and Aerotex, or diluent oil No. 585 and nonylphenol. Percentage and peak germination values, water uptake, sprout length, ATP content, and morphological modifications were recorded from 0 to 14 or 21 days. Apart from 100 ppm fenitrothion which stimulated germination values, germination in jack pine was only marginally affected by any of the treatments; in contrast, white birch was negatively affected by all treatments. The most sensitive parameters of toxicity were the sprout length and ATP content after 14 days growth. Aberrant hypocotyl/root length ratios were evidenced in pine seeds after exposure to xenobiotic treatments which did not affect the germinative capacity of seeds. ATP content in the 14-day-old pine and birch seedlings was consistently higher than controls in all treatment sets. (Refs. 29).

  18. 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....

  19. Bioremediation of treated wood with fungi

    Science.gov (United States)

    Barbara L. Illman; Vina W. Yang

    2006-01-01

    The authors have developed technologies for fungal bioremediation of waste wood treated with oilborne or metal-based preservatives. The technologies are based on specially formulated inoculum of wood-decay fungi, obtained through strain selection to obtain preservative-tolerant fungi. This waste management approach provides a product with reduced wood volume and the...

  20. Build Green: Wood Can Last for Centuries

    Science.gov (United States)

    Carol A. Clausen; Samuel V. Glass

    2012-01-01

    This report updates and revises information from the 1976 Forest Service publication by Rodney C. DeGroot, “Your Wood Can Last for Centuries.” It explains why wood decays, alerts the homeowner to conditions that can result in decay in buildings, and describes measures to prevent moisture-related damage to wood.

  1. Cone calorimeter tests of wood composites

    Science.gov (United States)

    Robert H. White; Kuma Sumathipala

    2013-01-01

    The cone calorimeter is widely used for the determination of the heat release rate (HRR) of building products and other materials. As part of an effort to increase the availability of cone calorimeter data on wood products, the U.S. Forest Products Laboratory and the American Wood Council conducted this study on composite wood products in cooperation with the Composite...

  2. Advances and challenges of wood polymer composites

    Science.gov (United States)

    Roger M. Rowell

    2006-01-01

    Wood flour and fiber have been blended with thermoplastic such as polyethylene, polypropylene, polylactic acid and polyvinyl chloride to form wood plastic composites (WPC). WPCs have seen a large growth in the United States in recent years mainly in the residential decking market with the removal of CCA treated wood decking from residential markets. While there are...

  3. The extractives of Pinus pinaster wood

    Science.gov (United States)

    Richard W. Hemingway; W. E. Hillis; L. S. Lau

    1973-01-01

    The extractives in Pinus pinaster wood grown in South Australia were examined as part of an assessment of the suitability of this wood for manufacture of absorbent tissues from bisulphite pulps. The average petroleum solubility of the wood was 2.0% but the amount and composition of the petroleum extract varied widely depending upon the age of the...

  4. Determination of pectin content of eucalyptus wood

    NARCIS (Netherlands)

    Coetzee, B.; Schols, H.A.; Wolfaardt, F.

    2011-01-01

    Very little is known about the occurrence of pectin in wood and it is speculated that between 10 mg g-1 and 40 mg g-1 of wood consists of pectin. The present study aimed to quantify pectin in eucalyptus wood and to determine the influence of tree species, yield potential of the site, tree age class

  5. 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.

  6. Mechanical Behaviour of the Wood Masonry

    Directory of Open Access Journals (Sweden)

    Fazia FOUCHAL

    2011-09-01

    Full Text Available In this paper we study the walls wood masonry behaviour. First, we propose a regulatory validation of the walls wood masonry behaviour subjected to vertical and horizontal loads according to Eurocode 5. Then we present the numerical application on the wall wood supported two floors level.

  7. Characteristics and availability of commercially important woods

    Science.gov (United States)

    Regis B. Miller

    1999-01-01

    Throughout history, the unique characteristics and comparative abundance of wood have made it a natural material for homes and other structures, furniture, tools, vehicles, and decorative objects. Today, for the same reasons, wood is prized for a multitude of uses. All wood is composed of cellulose, lignin, hemicelluloses, and minor amounts (5% to 10%) of extraneous...

  8. Wood Flour Moulding Technology: Implications for Technical ...

    African Journals Online (AJOL)

    User

    2011-04-19

    Apr 19, 2011 ... be waste product from saw mills, wood working plants or produced from selected dry wood by .... Stop watch-used to indicate the exact time the mould has remained in the press before wood .... There is abundance of saw dust the source of which is the ... Madison, Wisconsin: Wiley Interscience. Usoro, H. S. ...

  9. Contrasting short-term performance of mountain birch (Betula pubescens ssp. czerepanovii treeline along a latitudinal continentality-maritimity gradient in the southern Swedish Scandes

    Directory of Open Access Journals (Sweden)

    Lisa Öberg

    2012-01-01

    Full Text Available Positional treeline shift is a fundamental aspect and indicator of high-mountain vegetation response to climate change. This study analyses treeline performance during the period 2005/2007 -2010/2011 in the Swedish Scandes. Focus is on mountain birch (Betula pubescens ssp. czerepanovii along a regional climatic maritimity-continentality gradient. Treeline upshift by 3.0 yr-1 in the maritime part differed significantly from retreat by 0.4 m yr-1 in the continental part of the transect. This discrepancy is discussed in terms of differential warming-induced snow cover phenology patterns and their influence on soil moisture conditions. In the continental area, earlier and more complete melting of prior relatively rare late-lying snow patches, even high above the treeline, has progressed to a state when melt water irrigation ceases. As a consequence, soil drought sets back the vigor of existing birches and precludes sexual regeneration and upslope advance of the treeline. In the maritime area, extensive and deep snow packs still exist above the treeline and constrain its position, although some release is taking place in the current warm climate. Thereby, the birch treeline expands upslope as the alpine snow patches shrink, but continue to provide sufficient melt water throughout the summer. Treeline rise appears to have been based primarily on seed regeneration over the past few decades. This is a novelty, since prior (1915-2007 treeline advance was accomplished mainly by in situ shifts in growth form of relict krummholz birches, in some cases millennial-old, prevailing above the treeline. By the snow phenology mechanism, birch can benefit from climate warming in the maritime region, which contrasts with the situation in the continental region. This discrepancy should be accounted for in projective models. In a hypothetical case of sustained warming, the subalpine birch forest belt may expand less extensively than often assumed, although advance may

  10. The effect of cisplatin administration on certain trace elements homeostasis in rats and the protective effect of silver birch (Betula pendula) sap.

    Science.gov (United States)

    Muselin, Florin; Dumitrescu, Eugenia; Berbecea, Adina; Doma, Alexandru Octavian; Brezovan, Diana; Savici, Jelena; Trif, Alexandra; Cristina, Romeo Teodor

    2018-02-07

    A clinically active structure with known antitumor activities is cisplatin (CDDP), but this it comes with toxicity characteristics which can be faded by the beneficial effects of Silver birch (Betula pendula) sap. We aimed to assess the cisplatin activity on: Mn, Mg, Cu, Fe and Zn homeostasis in rats and to observe the effect of birch sap. Healthy Wistar rats (n = 10/group) were divided in four groups: Control: receiving 1 mL saline I.P. way + water; E1: cisplatin 20 mg kgbw -1 , I.P.; E2: cisplatin 20 mg kgbw -1 , I.P. + birch sap and Control sap group: 1 mL saline I.P. + birch sap. Blood was collected: at the trial's start and after 48 h, and blood and organs (liver, kidney and spleen) for the cytoarchitecture investigation and readings were sampled after seven days. Samples were processed in nitric acid by microwave digestion and readings were completed by flame atomic absorption spectroscopy, the outcomes being statistically analyzed by ANOVA. Cisplatin produced a significant imbalance in the trace elements homeostasis, the birch sap administration recovering them usual homeostasis status. Comparatively with the Control, rats exposed to cisplatin presented a not significant (p > 0.05) decrease of Zn (-26.74%) and Mg (-10.25%), a significant (p  0.05) increase of Mn (+28.16%). Birch sap administration after Cisplatin was followed by restoration or nevertheless significant increase (p sap against diverse cisplatin deleterious side-effects. Copyright © 2018 Elsevier GmbH. All rights reserved.

  11. Body of Wood

    Directory of Open Access Journals (Sweden)

    Pierre Michon

    2014-12-01

    not only a defrocked friar with the guys or on the street; he donned the silk babouches when he went home too. He dispossessed himself of the Seine that rolled on before his eyes; the small girl who lived on her feet, whom he puts to death in all his books, he hardly saw her; the loveliest girls of his day, the finest too for sure, who wanted him, so that he happened to come – he dispossessed himself of them, whether he came or opted to come no more, which amounted to the same thing; no apples from Norman orchards, no trees deep in the woods, no unlaced Louise Colet, no lilies, no young laughter, no Louise Colet weeping at his door, he kissed it all off, laughed over it and kissed it off, cried about it and kissed it off, he was not there. In fact he had nothing, he was deprived of everything, since it was in his head.

  12. Pelly Crossing wood chip boiler

    Energy Technology Data Exchange (ETDEWEB)

    1985-03-11

    The Pelly wood chip project has demonstrated that wood chips are a successful fuel for space and domestic water heating in a northern climate. Pelly Crossing was chosen as a demonstration site for the following reasons: its extreme temperatures, an abundant local supply of resource material, the high cost of fuel oil heating and a lack of local employment. The major obstacle to the smooth operation of the boiler system was the poor quality of the chip supply. The production of poor quality chips has been caused by inadequate operation and maintenance of the chipper. Dull knives and faulty anvil adjustments produced chips and splinters far in excess of the one centimetre size specified for the system's design. Unanticipated complications have caused costs of the system to be higher than expected by approximately $15,000. The actual cost of the project was approximately $165,000. The first year of the system's operation was expected to accrue $11,600 in heating cost savings. This estimate was impossible to confirm given the system's irregular operation and incremental costs. Consistent operation of the system for a period of at least one year plus the installation of monitoring devices will allow the cost effectiveness to be calculated. The wood chip system's impact on the environment was estimated to be minimal. Wood chip burning was considered cleaner and safer than cordwood burning. 9 refs., 6 figs., 6 tabs.

  13. Permian Silicified Wood in Oman

    Czech Academy of Sciences Publication Activity Database

    Matysová, Petra; Grygar, Tomáš

    -, č. 15 (2009), s. 14-18 ISSN N Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z40320502 Keywords : silicified wood * Oman * geology Subject RIV: DD - Geochemistry www.geologyoman.com/gso/Haj(Nov09).pdf

  14. Wood and concrete polymer composites

    International Nuclear Information System (INIS)

    Singer, K.

    1974-01-01

    There are several ways to prepare and use wood and concrete polymer composites. The most important improvements in the case of concrete polymer composites are obtained for compressive and tensile strengths. The progress in this field in United States and other countries is discussed in this rview. (M.S.)

  15. Adhesive bonding of wood materials

    Science.gov (United States)

    Charles B. Vick

    1999-01-01

    Adhesive bonding of wood components has played an essential role in the development and growth of the forest products industry and has been a key factor in the efficient utilization of our timber resource. The largest use of adhesives is in the construction industry. By far, the largest amounts of adhesives are used to manufacture building materials, such as plywood,...

  16. Detecting decay in wood components

    Science.gov (United States)

    R.J. Ross; X. Wang; B.K. Brashaw

    2005-01-01

    This chapter presents a summary of the Wood and Timber Condition Assessment Manual. It focuses on current inspection techniques for decay detection and provides guidelines on the use of various non-destructive evaluation (NDE) methods in locating and defining areas of deterioration in timber bridge components and other civil structures.

  17. 5000 sustainable workplaces - Wood energy provides work

    International Nuclear Information System (INIS)

    Keel, A.

    2009-01-01

    This article presents the results of a study made by the Swiss Wood Energy Association on the regional and national added value resulting from large wood-fired installations in Switzerland. The number of workplaces created by these installations is also noted. Wood energy is quoted as not only being a way of using forest wastes but also as being a creator of employment. Large wood-fired heating installations are commented on and efforts to promote this type of energy supply even further are discussed. The study indicates which professions benefit from the use of wood energy and quantifies the number of workplaces per megawatt of installed power that result.

  18. The case for wood-fuelled heating

    International Nuclear Information System (INIS)

    Bent, Ewan

    2001-01-01

    This article looks at the wood heating industry in the UK and examines the heat market and the growth potential in the domestic, public, agricultural and commercial sectors. The current status of wood-fueled heating technology is considered, along with log and chip boilers, and the use of pellet fuel. The economics of wood-fuelled heating, the higher level of utilisation of wood-fuelled heating by utilities in northern European countries compared with the UK, and the barriers to the exploitation of wood fuelled heating are examined

  19. Wood as a home heating fuel

    International Nuclear Information System (INIS)

    Wood, K.

    1991-01-01

    This article describes the development of clean-burning technology in three types of wood-burning appliances: catalytic, non-catalytic, and pellet stoves. A recent study by the Washington State Energy Extension Office concluded that in homes that use both electricity and wood, 73 megawatts of electricity/yr were saved by using wood. Since wood-burning stoves can now meet air quality standards, wood could be considered to be a greenhouse-neutral fuel if more trees are planted as they are consumed

  20. The natural catalytic function of CuGE glucuronoyl esterase in hydrolysis of genuine lignin-carbohydrate complexes from birch

    DEFF Research Database (Denmark)

    Mosbech, Caroline; Holck, Jesper; Meyer, Anne S.

    2018-01-01

    Glucuronoyl esterases belong to carbohydrate esterase family 15 and catalyze de-esterification. Their natural function is presumed to be cleavage of ester linkages in lignin-carbohydrate complexes particularly those linking lignin and glucuronoyl residues in xylans in hardwood. Here, we show...... for the first time a detailed product profile of aldouronic acids released from birchwood lignin by a glucuronoyl esterase from the white-rot fungus Cerrena unicolor (CuGE). CuGE releases substrate for GH10 endo-xylanase which results in significantly increased product release compared to the action of endo......-xylanase alone. CuGE also releases neutral xylo-oligosaccharides that can be ascribed to the enzymes feruloyl esterase side activity as demonstrated by release of ferulic acid from insoluble wheat arabinoxylan. The data verify the enzyme's unique ability to catalyze removal of all glucuronoxylan associated...

  1. How does solar ultraviolet-B radiation improve drought tolerance of silver birch (Betula pendula Roth.) seedlings?

    Science.gov (United States)

    Robson, T Matthew; Hartikainen, Saara M; Aphalo, Pedro J

    2015-05-01

    We hypothesized that solar ultraviolet (UV) radiation would protect silver birch seedlings from the detrimental effects of water stress through a coordinated suite of trait responses, including morphological acclimation, improved control of water loss through gas exchange and hydraulic sufficiency. To better understand how this synergetic interaction works, plants were grown in an experiment under nine treatment combinations attenuating ultraviolet-A and ultraviolet-B (UVB) from solar radiation together with differential watering to create water-deficit conditions. In seedlings under water deficit, UV attenuation reduced height growth, leaf production and leaf length compared with seedlings receiving the full spectrum of solar radiation, whereas the growth and morphology of well-watered seedlings was largely unaffected by UV attenuation. There was an interactive effect of the treatment combination on water relations, which was more apparent as a change in the water potential at which leaves wilted or plants died than through differences in gas exchange. This suggests that changes occur in the cell wall elastic modulus or accumulation of osmolites in cells under UVB. Overall, the strong negative effects of water deficit are partially ameliorated by solar UV radiation, whereas well-watered silver birch seedlings are slightly disadvantaged by the solar UV radiation they receive. © 2014 John Wiley & Sons Ltd.

  2. Experimental methods for the Palaeolithic dry distillation of birch bark: implications for the origin and development of Neandertal adhesive technology.

    Science.gov (United States)

    Kozowyk, P R B; Soressi, M; Pomstra, D; Langejans, G H J

    2017-08-31

    The destructive distillation of birch bark to produce tar has recently featured in debates about the technological and cognitive abilities of Neandertals and modern humans. The abilities to precisely control fire temperatures and to manipulate adhesive properties are believed to require advanced mental traits. However, the significance given to adhesive technology in these debates has quickly outgrown our understanding of birch bark tar and its manufacture using aceramic techniques. In this paper, we detail three experimental methods of Palaeolithic tar production ranging from simple to complex. We recorded the fuel, time, materials, temperatures, and tar yield for each method and compared them with the tar known from the Palaeolithic. Our results indicate that it is possible to obtain useful amounts of tar by combining materials and technology already in use by Neandertals. A ceramic container is not required, and temperature control need not be as precise as previously thought. However, Neandertals must have been able to recognize certain material properties, such as adhesive tack and viscosity. In this way, they could develop the technology from producing small traces of tar on partially burned bark to techniques capable of manufacturing quantities of tar equal to those found in the Middle Palaeolithic archaeological record.

  3. The impact of climate change on ecosystem carbon dynamics at the Scandinavian mountain birch forest-tundra heath ecotone.

    Science.gov (United States)

    Sjögersten, Sofie; Wookey, Philip A

    2009-02-01

    Changes in temperature and moisture resulting from climate change are likely to strongly modify the ecosystem carbon sequestration capacity in high-latitude areas, both through vegetation shifts and via direct warming effects on photosynthesis and decomposition. This paper offers a synthesis of research addressing the potential impacts of climate warming on soil processes and carbon fluxes at the forest-tundra ecotone in Scandinavia. Our results demonstrated higher rates of organic matter decomposition in mountain birch forest than in tundra heath soils, with markedly shallower organic matter horizons in the forest. Field and laboratory experiments suggest that increased temperatures are likely to increase CO2 efflux from both tundra and forest soil providing moisture availability does not become limiting for the decomposition process. Furthermore, colonization of tundra heath by mountain birch forest would increase rates of decomposition, and thus CO2 emissions, from the tundra heath soils, which currently store substantial amounts of potentially labile carbon. Mesic soils underlying both forest and tundra heath are currently weak sinks of atmospheric methane, but the strength of this sink could be increased with climate warming and/or drying.

  4. A Preliminary Pharmacokinetic Study of Betulin, the Main Pentacyclic Triterpene from Extract of Outer Bark of Birch (Betulae alba cortex

    Directory of Open Access Journals (Sweden)

    Melanie N. Laszczyk

    2008-12-01

    Full Text Available During the last two decades triterpenes have attracted attention because of their pharmacological potential. Triterpene extract (TE from outer bark of birch consisting mainly of betulin is able to form an oleogel which was successfully tested in the treatment of actinic keratosis. Some aspects of TE in vitro pharmacology are already known. Now we show preliminary pharmacokinetics of betulin and results of a subchronic toxicity study of TE in rats and dogs. Because of poor aqueous solubility of the TE-triterpenes (< 0.1 μg/mL respectively, for pharmacokinetic studies it was suspended in sesame oil (rats, i.p. and PEG 400 / 0.9 % NaCl (dogs, s.c.. I.p. administered, betulin, the main component of TE, shows time dependency over a period of 4 h and reaches a dose-independent serum level of 0.13 μg/mL. Dose dependency was observed with s.c. administration. At 300 mg/kg a maximum plasma concentration of 0.33 μg/mL betulin was detected after 28 daily applications. The subchronic toxicity study showed no toxicity of TE in rats (i.p. and dogs (s.c.. In conclusion, triterpene extract from birch bark is safe, its betulin is bioavailable and in addition to published triterpene biological activities TE provides high potential for further pharmaceutical and pharmacological research.

  5. Gene expression responses of paper birch (Betula papyrifera) to elevated CO2 and O3 during leaf maturation and senescence

    International Nuclear Information System (INIS)

    Kontunen-Soppela, Sari; Parviainen, Juha; Ruhanen, Hanna; Brosche, Mikael; Keinaenen, Markku; Thakur, Ramesh C.; Kolehmainen, Mikko; Kangasjaervi, Jaakko; Oksanen, Elina; Karnosky, David F.; Vapaavuori, Elina

    2010-01-01

    Gene expression responses of paper birch (Betula papyrifera) leaves to elevated concentrations of CO 2 and O 3 were studied with microarray analyses from three time points during the summer of 2004 at Aspen FACE. Microarray data were analyzed with clustering techniques, self-organizing maps, K-means clustering and Sammon's mappings, to detect similar gene expression patterns within sampling times and treatments. Most of the alterations in gene expression were caused by O 3 , alone or in combination with CO 2 . O 3 induced defensive reactions to oxidative stress and earlier leaf senescence, seen as decreased expression of photosynthesis- and carbon fixation-related genes, and increased expression of senescence-associated genes. The effects of elevated CO 2 reflected surplus of carbon that was directed to synthesis of secondary compounds. The combined CO 2 + O 3 treatment resulted in differential gene expression than with individual gas treatments or in changes similar to O 3 treatment, indicating that CO 2 cannot totally alleviate the harmful effects of O 3 . - Clustering analysis of birch leaf gene expression data reveals differential responses to O 3 and CO 2 .

  6. Evaluation of a New Temporary Immersion Bioreactor System for Micropropagation of Cultivars of Eucalyptus, Birch and Fir

    Directory of Open Access Journals (Sweden)

    Edward Businge

    2017-06-01

    Full Text Available The use of liquid instead of solid culture medium for the micropropagation of plants offers advantages such as better access to medium components and scalability through possible automation of the processes. The objective of this work was to compare a new temporary immersion bioreactor (TIB to solid medium culture for the micropropagation of a selection of tree species micropropagated for commercial use: Nordmann fir (Abies nordmanniana (Steven Spach, Eucalyptus (E. grandis x E. urophylla, Downy birch (Betula pubescens Ehrh, and Curly birch (Betula pendula var. carelica. Cultivation of explants in the TIB resulted in a significant increase of multiplication rate and fresh weight of Eucalyptus and B. pendula, but not Betula pubescens. In addition, the fresh weight of embryogenic tissue and the maturation frequency of somatic embryos increased significantly when an embryogenic cell line of A. nordmanniana was cultivated in the TIB compared to solid culture medium. These results demonstrate the potential for scaling up and automating micropropagation by shoot multiplication and somatic embryogenesis in commercial tree species using a temporary immersion bioreactor.

  7. Functional characterization of CCR in birch (Betula platyphylla × Betula pendula) through overexpression and suppression analysis.

    Science.gov (United States)

    Zhang, Wenbo; Wei, Rui; Chen, Su; Jiang, Jing; Li, Huiyu; Huang, Haijiao; Yang, Guang; Wang, Shuo; Wei, Hairong; Liu, Guifeng

    2015-06-01

    We cloned a Cinnamoyl-CoA Reductase gene (BpCCR1) from an apical meristem and first internode of Betula platyphylla and characterized its functions in lignin biosynthesis, wood formation and tree growth through transgenic approaches. We generated overexpression and suppression transgenic lines and analyzed them in comparison with the wild-type in terms of lignin content, anatomical characteristics, height and biomass. We found that BpCCR1 overexpression could increase lignin content up to 14.6%, and its underexpression decreased lignin content by 6.3%. Surprisingly, modification of BpCCR1 expression led to conspicuous changes in wood characteristics, including xylem vessel number and arrangement, and secondary wall thickness. The growth of transgenic trees in terms of height was also significantly influenced by the modification of BpCCR1 genes. We discuss the functions of BpCCR1 in the context of a phylogenetic tree built with CCR genes from multiple species. © 2014 Scandinavian Plant Physiology Society.

  8. Screening and characterizing of xylanolytic and xylose-fermenting yeasts isolated from the wood-feeding termite, Reticulitermes chinensis.

    Directory of Open Access Journals (Sweden)

    Sameh Samir Ali

    Full Text Available The effective fermentation of xylose remains an intractable challenge in bioethanol industry. The relevant xylanase enzyme is also in a high demand from industry for several biotechnological applications that inevitably in recent times led to many efforts for screening some novel microorganisms for better xylanase production and fermentation performance. Recently, it seems that wood-feeding termites can truly be considered as highly efficient natural bioreactors. The highly specialized gut systems of such insects are not yet fully realized, particularly, in xylose fermentation and xylanase production to advance industrial bioethanol technology as well as industrial applications of xylanases. A total of 92 strains from 18 yeast species were successfully isolated and identified from the gut of wood-feeding termite, Reticulitermes chinensis. Of these yeasts and strains, seven were identified for new species: Candida gotoi, Candida pseudorhagii, Hamamotoa lignophila, Meyerozyma guilliermondii, Sugiyamaella sp.1, Sugiyamaella sp. 2, and Sugiyamaella sp.3. Based on the phylogenetic and phenotypic characterization, the type strain of C. pseudorhagii sp. nov., which was originally designated strain SSA-1542T, was the most frequently occurred yeast from termite gut samples, showed the highly xylanolytic activity as well as D-xylose fermentation. The highest xylanase activity was recorded as 1.73 and 0.98 U/mL with xylan or D-xylose substrate, respectively, from SSA-1542T. Among xylanase-producing yeasts, four novel species were identified as D-xylose-fermenting yeasts, where the yeast, C. pseudorhagii SSA-1542T, showed the highest ethanol yield (0.31 g/g, ethanol productivity (0.31 g/L·h, and its fermentation efficiency (60.7% in 48 h. Clearly, the symbiotic yeasts isolated from termite guts have demonstrated a competitive capability to produce xylanase and ferment xylose, suggesting that the wood-feeding termite gut is a promising reservoir for novel

  9. Wood pellets : a worldwide fuel commodity

    International Nuclear Information System (INIS)

    Melin, S.

    2005-01-01

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

  10. Analysis of functional xylanases in xylan degradation by Aspergillus niger E-1 and characterization of the GH family 10 xylanase XynVII.

    Science.gov (United States)

    Takahashi, Yui; Kawabata, Hiroaki; Murakami, Shuichiro

    2013-01-01

    Xylanases produced by Aspergillus niger are industrially important and many types of xylanases have been reported. Individual xylanases have been well studied for their enzymatic properties, gene cloning, and heterologous expression. However, less attention has been paid to the relationship between xylanase genes carried on the A. niger genome and xylanases produced by A. niger strains. Therefore, we examined xylanase genes encoded on the genome of A. niger E-1 and xylanases produced in culture. Seven putative xylanase genes, xynI-VII (named in ascending order of the molecular masses of the deduced amino acid sequences), were amplified from the strain E-1 genome using primers designed from the genome sequence of A. niger CBS 513.88 by PCR and phylogenetically classified into three clusters. Additionally, culture supernatant analysis by DE52 anion-exchange column chromatography revealed that this strain produced three xylanases, XynII, XynIII, and XynVII, which were identified by N-terminal amino acid sequencing and MALDI-TOF-MS analyses, in culture when gown in 0.5% xylan medium supplemented with 50 mM succinate. Furthermore, XynVII, the only GH family 10 xylanase in A. niger E-1, was purified and characterized. The purified enzyme showed a single band with a molecular mass of 35 kDa by SDS-PAGE. The highest activity of purified XynVII was observed at 55°C and pH 5.5. The enzyme was stable in the broad pH range of 3-10 and up to 60°C and was resistant to most metal ions and modifying regents. XynVII showed high specificity against beechwood xylan with K m and V max values of 2.8 mg mL(-1) and 127 μmol min(-1)mg(-1), respectively. TLC and MALDI-TOF-MS analyses showed that the final hydrolyzed products of the enzyme from beechwood xylan were xylose, xylobiose, and xylotriose substituted with a 4-o-metylglucuronic acid residue.

  11. Kinetic Modelling and Experimental Studies for the Effects of Fe2+ Ions on Xylan Hydrolysis with Dilute-Acid Pretreatment and Subsequent Enzymatic Hydrolysis

    Directory of Open Access Journals (Sweden)

    Hui Wei

    2018-01-01

    Full Text Available High-temperature (150–170 °C pretreatment of lignocellulosic biomass with mineral acids is well established for xylan breakdown. Fe2+ is known to be a cocatalyst of this process although kinetics of its action remains unknown. The present work addresses the effect of ferrous ion concentration on sugar yield and degradation product formation from corn stover for the entire two-step treatment, including the subsequent enzymatic cellulose hydrolysis. The feedstock was impregnated with 0.5% acid and 0.75 mM iron cocatalyst, which was found to be optimal in preliminary experiments. The detailed kinetic data of acid pretreatment, with and without iron, was satisfactorily modelled with a four-step linear sequence of first-order irreversible reactions accounting for the formation of xylooligomers, xylose and furfural as intermediates to provide the values of Arrhenius activation energy. Based on this kinetic modelling, Fe2+ turned out to accelerate all four reactions, with a significant alteration of the last two steps, that is, xylose degradation. Consistent with this model, the greatest xylan conversion occurred at the highest severity tested under 170 °C/30 min with 0.75 mM Fe2+, with a total of 8% xylan remaining in the pretreated solids, whereas the operational conditions leading to the highest xylose monomer yield, 63%, were milder, 150 °C with 0.75 mM Fe2+ for 20 min. Furthermore, the subsequent enzymatic hydrolysis with the prior addition of 0.75 mM of iron(II increased the glucose production to 56.3% from 46.3% in the control (iron-free acid. The detailed analysis indicated that conducting the process at lower temperatures yet long residence times benefits the yield of sugars. The above kinetic modelling results of Fe2+ accelerating all four reactions are in line with our previous mechanistic research showing that the pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C

  12. Mathematical Simulation of Temperature Profiles within Microwave Heated Wood Made for Wood-Based Nano composites

    International Nuclear Information System (INIS)

    Li, X.; He, X.; Lv, J.; Wu, Y.; Luo, Y.; Chen, H.

    2013-01-01

    High intensive microwave pretreatment is a new method to modify wood for the fabrication of wood-based nano composites. Based on the physical law on heat transfer, a mathematical model to describe the temperature profiles within wood heated by high intensive microwave was established and simulated in this research. The results showed that the temperature profiles within wood were related to microwave heating methods; The temperature inside wood firstly increased and then gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied, and the temperature difference along the thickness direction of wood was very significant; The temperature with wood firstly increased and then gradually decreased from the wood surface to interior when the bilateral microwave heating was applied. Compared with the unilateral microwave heating, bilateral microwave heating is a better microwave heating method for the more uniform wood microwave pretreatment.

  13. β-D-(1→4), β-D-(1→3) 'mixed linkage' xylans from red seaweeds of the order Nemaliales and Palmariales.

    Science.gov (United States)

    Viana, Adriano G; Noseda, Miguel D; Gonçalves, Alan G; Duarte, Maria Eugênia R; Yokoya, Nair; Matulewicz, Maria C; Cerezo, Alberto S

    2011-06-01

    Xylans from five seaweeds belonging to the order Nemaliales (Galaxaura marginata, Galaxaura obtusata, Tricleocarpacylindrica, Tricleocarpa fragilis, and Scinaia halliae) and one of the order Palmariales (Palmaria palmata) collected on the Brazilian coasts were extracted with hot water and purified from acid xylomannans and/or xylogalactans through Cetavlon precipitation of the acid polysaccharides. The β-D-(1→4), β-D-(1→3) 'mixed linkage' structures were determined using methylation analysis and 1D and 2D NMR spectroscopy. The presence of large sequences of β-(1→4)-linked units suggests transient aggregates of ribbon- or helical-ordered structures that would explain the low optical rotations. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Advantages of the use of energy wood

    International Nuclear Information System (INIS)

    Kaerhae, K.; Aarnio, J.; Maekinen, P.

    2000-01-01

    According to the Regional Forestry Associations it would be possible to develop the harvesting of energy wood by increasing the use of it. The study was made at the areas of 34 regional forestry associations as an inquiry to the executive managers, as well as the persons responsible for timber trade, harvesting or regional affairs. The inquiries studied the use of energy wood and the user of them at the areas of the associations, as well as the amounts of harvesting and the realization of it. Only a third of the associations have large energy wood consuming plants (using more than 500 m 3 energy wood per year). The closest large energy wood consuming plant was in the average 31 km from the office of the association. The average energy wood use of the plant was 20 000 m 3 /a, the variation being 700 - 200 000 m 3 /a. The energy wood purchase range of the plants varied from few kilometers to hundred kilometers, the average being 47 km. Most of the energy wood was harvested from forest regeneration areas. Some of the energy wood is also harvested from young forest maintenance and thinning areas. The estimated harvesting of energy wood in 1999 was 6300 m 3 . A part of the energy wood is used for heating the farms and other small real estates, and a part is used for heating larger buildings like schools, hospitals, factories. The fees to the associations for purchase of energy wood varied significantly. The range was 2.00 - 11.00 FIM/m 3 . One association charged 300 FIM/parcel, and in one association the price depend on the amount of wood acquired from the lot, the unit price being 0.5 FIM/m 3 . It appeared that the associations estimated the use of energy wood to increase. The level in 1999 was 6300 m 3 and it is estimated to increase to 14 300 m 3 in 2005. The associations estimated that the levels can only be achieved if the stumpage price of energy wood may not be 0.0 FIM. Even a marginal price would lead to an increased harvesting of energy wood. The associations

  15. Wood energy and air quality

    International Nuclear Information System (INIS)

    2015-12-01

    This publication first recalls the main benefits of the use of wood, the first source of renewable energy in France: abundant and local resource, low CO 2 emission, competitiveness, job creation. It comments the relationship between the use of this source of energy and the compliance with air quality standards as they are notably defined by European directives, as the use of wood as heating source is one of the recommended lever to improve air quality. The publication comments emissions generated by this type of heating (mainly in the housing sector, with some critical meteorological periods). Levers for actions are discussed: fleet renewal to promote the best performing equipment, practice improvements (fuel quality, apparatus maintenance). Actions undertaken by the ADEME are briefly reviewed: support to individual equipment fleet modernisation, support to R and D, support to the sector, and information and communication

  16. Crystallization and preliminary X-ray analysis of birch-pollen allergen Bet v 1 in complex with a murine monoclonal IgG Fab' fragment

    DEFF Research Database (Denmark)

    Spangfort, M D; Mirza, Osman Asghar; Gajhede, M

    1999-01-01

    of the clinical symptoms of allergy. In order to study the structural basis of allergen-antibody interaction, a complex between the major birch-pollen allergen Bet v 1 and a Fab' fragment isolated from the murine monoclonal Bet v 1 antibody BV16 has been crystallized. Complex crystals belong to space group P1...

  17. Ozone-induced H2O2 accumulation in field-grown aspen and birch is linked to foliar ultrastructure and peroxisomal activity

    Science.gov (United States)

    E. Oksanen; E. Häikiö; J. Sober; D.F. Karnosky

    2003-01-01

    Saplings of three aspen (Populus tremuloides) genotypes and seedlings of paper birch (Betula papyrifera) were exposed to elevated ozone (1.5x ambient) and 560 p.p.m. CO2, singly and in combination, from 1998 at the Aspen-FACE (free-air CO2 enrichment) site (Rhinelander, USA).

  18. Ozone and climate - Effects of the excess of critical loads on birches and mountain plants; Ozon og klima - effekter av taalegrenseoverskridelser paa bjoerk og fjellplanter

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, L M

    1996-01-01

    The conference paper relates to the environmental effects of high concentrated ozone on the biomass production in Norway. The effects on birches and mountain plants from ozone together with the interaction between ozone and carbon dioxide and their influence on vegetation are discussed

  19. Concentrations of Ca and Mg in early stages of sapwood decay in red spruce, eastern hemlock, red maple, and paper birch

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle; Jody Jellison; Jon Connolly; Jonathan Schilling

    2007-01-01

    The decay of coarse woody debris is a key component in the formation of forest soil and in the biogeochemical cycles of Ca and Mg. We tracked changes in density and concentration of Ca and Mg in sapwood of red maple (Acer rubrum L.), red spruce (Picea rubens Sarg.), paper birch (Betula papyrifera Marsh.), and...

  20. Wood and Sediment Dynamics in River Corridors

    Science.gov (United States)

    Wohl, E.; Scott, D.

    2015-12-01

    Large wood along rivers influences entrainment, transport, and storage of mineral sediment and particulate organic matter. We review how wood alters sediment dynamics and explore patterns among volumes of instream wood, sediment storage, and residual pools for dispersed pieces of wood, logjams, and beaver dams. We hypothesized that: volume of sediment per unit area of channel stored in association with wood is inversely proportional to drainage area; the form of sediment storage changes downstream; sediment storage correlates most strongly with wood load; and volume of sediment stored behind beaver dams correlates with pond area. Lack of data from larger drainage areas limits tests of these hypotheses, but analyses suggest a negative correlation between sediment volume and drainage area and a positive correlation between wood and sediment volume. The form of sediment storage in relation to wood changes downstream, with wedges of sediment upstream from jammed steps most prevalent in small, steep channels and more dispersed sediment storage in lower gradient channels. Use of a published relation between sediment volume, channel width, and gradient predicted about half of the variation in sediment stored upstream from jammed steps. Sediment volume correlates well with beaver pond area. Historically more abundant instream wood and beaver populations likely equated to greater sediment storage within river corridors. This review of the existing literature on wood and sediment dynamics highlights the lack of studies on larger rivers.

  1. Management alternatives of energy wood thinning stands

    International Nuclear Information System (INIS)

    Heikkilae, Jani; Siren, Matti; Aeijaelae, Olli

    2007-01-01

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

  2. WOOD BIOMASS FOR ENERGY IN MONTENEGRO

    Directory of Open Access Journals (Sweden)

    Gradimir Danon

    2010-01-01

    Full Text Available Wood biomass has got its place in the energy balance of Montenegro. A little more than 6% of the total energy consumption is obtained by burning wood. Along with the appropriate state measures, it is economically and environmentally justified to expect Montenegro to more than double the utilization of the existing renewable energy sources including wood biomass, in the near future. For the purpose of achieving this goal, ‘Commercial Utilisation of the Wood Residue as a Resource for Economic Development in the North of Montenegro' project was carried out in 2007. The results of this project were included in the plan of the necessary interventions of the Government and its Agencies, associations or clusters, non-government organisations and interested enterprises. The plan was made on the basis of the wood residue at disposal and the attitude of individual subjects to produce and/or use solid bio-fuels and consists of a proposal of collection and utilisation of the wood residue for each individual district in the north of Montenegro. The basic factors of sustainability of future commercialisation of the wood residue were: availability of the wood raw material, and thereby the wood residue; the development of wood-based fuel markets, and the size of the profit.

  3. Examining Young's modulus for wood

    International Nuclear Information System (INIS)

    Perkalskis, Benjamin S; Freeman, J Reuben; Suhov, Alexander

    2004-01-01

    Symmetry considerations, dimensional analysis and simple approximations are used to derive a formula for Young's modulus of a simple anisotropic system, a straight-layer wood bar whose fibre axis makes an angle with respect to the bar's longitudinal axis. Agreement between the derived formula and experiment (carried out in far from ideal conditions) is within 10%. Improvements and extensions are suggested for this undergraduate physics experiment

  4. Blood parasites of wood ducks

    Science.gov (United States)

    Herman, C.M.; Knisley, J.O.; Knipling, G.D.

    1971-01-01

    Examination of blood films from wood ducks (Aix sponsa) from several northeastern states revealed Haemoproteus, Leucocytozoon, Plasmodium and a typanosome. Haemoproteus occurred in all areas sampled and birds of the year from Massachusetts demonstrated the highest incidence during the last 2 weeks in August. Leucocytozoon was most prevalent in more northern areas. P. circumflexum and a trypanosome are reported for the first time from this host.

  5. Discover the benefits of residential wood heating

    International Nuclear Information System (INIS)

    2003-01-01

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

  6. Fluorescing macerals from wood precursors

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S A; Bensley, D F

    1987-01-01

    A preliminary investigation into the origin of wood-derived macerals has established the existence of autofluorescent maceral precursors in the secondary xylem of swamp-inhabiting plant species. The optical character and fluorescent properties of microtomed thin-sections of modern woods from the Florida Everglades and Okefenokee Swamp, Georgia are compared to the character and properties of their peatified equivalents from various Everglades and Okefenokee peat horizons and their lignitic equivalents from the Brandon lignite of Vermont and the Trail Ridge lignitic peat from northern Florida. The inherent fluorescence of woody cell walls is believed to be caused by lignin though other cell wall components may contribute. The fluorescence spectra for several wood and cell types had a ..gamma../sub m//sub a//sub x/ of 452 nm and Q value of 0.00. The color as observed in blue light and the spectral geometry as measured in UV light of peatified and lignitic woody cell walls (potential textinites) may change progressively during early coalification. Cell wall-derived maceral material is shown to maintain its fluorescing properties after being converted to a structureless material, perhaps a corpohuminite or humodetrinite precursor. Fluorescing xylem cell contents, such as condensed tannins or essential oils, can maintain the fluorescent character through early coalification. Xylem cell walls and xylem cell contents are shown to provide fluorescing progenitor materials which would not require subsequent infusion with 'lipid' materials to account for their fluorescence as phytoclast material or as macerals in coal. 35 references.

  7. Competitive outcomes between wood-decaying fungi are altered in burnt wood.

    Science.gov (United States)

    Edman, Mattias; Eriksson, Anna-Maria

    2016-06-01

    Fire is an important disturbance agent in boreal forests where it creates a wide variety of charred and other types of heat-modified dead wood substrates, yet how these substrates affect fungal community structure and development within wood is poorly understood. We allowed six species of wood-decaying basidiomycetes to compete in pairs in wood-discs that were experimentally burnt before fungal inoculation. The outcomes of interactions in burnt wood differed from those in unburnt control wood for two species:Antrodia sinuosanever lost on burnt wood and won over its competitor in 67% of the trials compared to 40% losses and 20% wins on unburnt wood. In contrast, Ischnoderma benzoinumwon all interactions on unburnt wood compared to 33% on burnt wood. However, the responses differed depending on the identity of the competing species, suggesting an interaction between competitor and substrate type. The observed shift in competitive balance between fungal species probably results from chemical changes in burnt wood, but the underlying mechanism needs further investigation. Nevertheless, the results indicate that forest fires indirectly structure fungal communities by modifying dead wood, and highlight the importance of fire-affected dead wood substrates in boreal forests. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Long-term development of experimental mixtures of Scots pine (Pinus sylvestris L. and silver birch (Betula pendula Roth. in northern Britain

    Directory of Open Access Journals (Sweden)

    Bill Mason

    2016-07-01

    Full Text Available The Caledonian pinewoods of northern Scotland are a priority conservation habitat in Europe which are dominated by Scots pine (Pinus sylvestris, but varying proportions of a number of broadleaved species such as silver birch (Betula pendula can occur in these forests. Better understanding of the dynamics of mixed Scots pine-birch stands would be helpful in informing current initiatives to restore and increase the area of the pinewood ecosystem. Some evidence is provided by two experiments established in the 1960s which compared plots of pure Scots pine and pure birch with two treatments where the two species were mixed in 3:1 and 1:1 ratios. Some fifty years later, Scots pine was the more vigorous of the two species in these experiments, being both taller and significantly larger in diameter. The highest basal area was generally found in the pure Scots pine plots and the values in the mixed plots tended to be intermediate between those of the two component species. Examination of the growth in the mixed plots showed a slight, but non-significant, tendency towards overyielding. This appeared to be due to Scots pine growth being better than predicted, while that of birch was slightly less than predicted. These results suggest that in these mixtures, which are composed of two light demanding species, the main mechanism driving long-term performance is competition for light and there is little evidence of any complementary effect. These results suggest that any strategy seeking to increase the long-term representation of broadleaves such as birch in the Caledonian pinewoods will need to create discrete blocks that are large enough to withstand the competitive pressures exerted by the pine.

  9. Seasonal and inter-annual variation of Beryllium-7 deposition in birch-tree leaves and grass in the northeast upland area of the Czech Republic

    Energy Technology Data Exchange (ETDEWEB)

    Poeschl, Michael, E-mail: poschl@mendelu.c [Department of Molecular Biology and Radiobiology, Faculty of Agronomy, Mendel University of Agriculture in Brno, Zemedelska 1, 61300 Brno (Czech Republic); Brunclik, Tomas, E-mail: brunclik@georadis.co [Georadis s.r.o., Hudcova 56b, 621 00 Brno (Czech Republic); Hanak, Jaromir, E-mail: jaromir.hanak@geology.c [Czech Geological Survey, Department of Environmental Geology and Geophysics, Leitnerova 22, 658 69 Brno (Czech Republic)

    2010-09-15

    The activity concentrations of Beryllium-7 ({sup 7}Be), a naturally occurring radioisotope produced in the atmosphere, were measured in leaves of birch-trees, above-ground parts of grass, soil and rainwater in the mountain massive Kralicky Sneznik (the northeast of the Czech Republic, altitude about 750 m) in the years of 2005, 2006 and 2007. Dried and ground samples of the plants and soils, and water samples from wet deposition were used to determine the {sup 7}Be content using a semiconductor gamma spectrometer. The {sup 7}Be values ranged from 147.0 to 279.6 Bq kg{sup -1}, from 48.7 to 740.8 Bq kg{sup -1}, from 2.1 to 8.7 Bq kg{sup -1}, and from 0.6 to 1.9 Bq kg{sup -1} in birch-tree leaves, grass samples, soils, and rainwater, respectively. Insignificant inter-annual variations but significant increase in the {sup 7}Be activity concentrations during the spring and summer months were observed in birch-tree leaves and grass samples. The seasonal variation of the {sup 7}Be concentrations in grass samples correlated (R{sup 2} = 0.4663 and 0.6489) with precipitation. No similar correlation was found for {sup 7}Be in birch-tree leaves. Beryllium-7 content in birch-tree leaves and in aerial parts of grass was mainly caused by direct transport of {sup 7}Be from wet deposition into aerial parts of the observed plants.

  10. EVOLUTION OF LIGHTWEIGHT WOOD COMPOSITES

    Directory of Open Access Journals (Sweden)

    Marius C. BARBU

    2016-01-01

    Full Text Available Lightweight boards and beams in the wood-based construction and furniture industry are not a new topic. The density reduction of panels using sandwich structure with light cores was confirmed by users like doors or mobile homes more than three decades ago. Today many ways to attain a lighter wooden structure are on offer, partially in industrial application. The first one is the use of light-weight wood species like balsa, lime, pine from southern hemisphere plantations etc. limited by the availability, strength properties, gluability and so on. A second one is the sandwich structure made from hard faces like thick veneer, thin plywood, particleboard or high density thin fiberboard and cores made from honeycomb paper, very light wood species or foams like the polystyrene one. A third way to produce a light structure is to reduce the core drastically, using predesigned skeletons with special shapes and connections to the faces. The engines for these developments are on the one hand the fast growing market of knockdown furniture and on the other hand the increasing costs for energy and raw materials. Additional factors that make weight saving a primary economical objective for most producers are transportation costs, easier handling and higher acceptance among the end users. Moreover, customers demand more for ergonomical solutions regarding packaging. Many patents were generated by researchers and developers for new one-stage production processes for sandwich panels with wood- and impregnated paper-based facings made from veneers, particles or fibres and a core consisting of expandable foams, particles or embedded hard skeletons. These ideas or prototypes could be integrated in existing continuous pressing lines for wood based panels keeping some of the advantages of the continuous production technique in matters of efficiency. Some of the challenges of the light weight wooden structure are the connection in half or final parts, resistance to

  11. Carbon sequestration via wood burial

    Directory of Open Access Journals (Sweden)

    Zeng Ning

    2008-01-01

    Full Text Available Abstract To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink. It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 ± 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1, followed by temperate (3.7 GtC y-1 and boreal forests (2.1 GtC y-1. Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized. Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC, lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.

  12. Adhesives for Achieving Durable Bonds with Acetylated Wood

    Science.gov (United States)

    Charles Frihart; Rishawn Brandon; James Beecher; Rebecca Ibach

    2017-01-01

    Acetylation of wood imparts moisture durability, decay resistance, and dimensional stability to wood; however, making durable adhesive bonds with acetylated wood can be more difficult than with unmodified wood. The usual explanation is that the acetylated surface has fewer hydroxyl groups, resulting in a harder-to-wet surface and in fewer hydrogen bonds between wood...

  13. Wood Programs. Courseware Evaluation for Vocational and Technical Education.

    Science.gov (United States)

    Kaylor, Robert; And Others

    This courseware evaluation rates the Wood Programs software developed by the Iowa Department of Public Instruction. (These programs--not contained in this document--include understanding board feet, wood characteristics, wood safety drill, wood dimensions, wood moisture, operating the table saw, radial arm, measurement drill, fraction drill, and…

  14. Chapter 02: Basic wood biology—Anatomy for identification

    Science.gov (United States)

    Alex Wiedenhoeft

    2011-01-01

    Before the topics of using a hand lens, preparing wood for observation, and understanding the characters used in wood identification can be tackled, a general introduction to the biology of wood must be undertaken. The woods in commercial trade in Central America come almost exclusively from trees, so the discussion of wood biology is restricted to trees here, though...

  15. Ethanol from wood 'can be competitive'

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-19

    Estimates by Stones and Webster indicate that the cost of producing ethanol for fuel purposes from wood will be as cheap as any other method and comparable with proven sugarcane and maize technology. In coming to this conclusion, it was assumed that significant advances would be made in the hydrolysis of wood and that saleable by-products would be possible from the lignin and hemicellulose of the feedstock wood.

  16. Forest biomass and wood waste resources

    Science.gov (United States)

    K. Skog; P. Lebow; D.. Dykstra; P.. Miles; B.J. Stokes; R.D. Perlack; M. Buford; J. Barbour; D. McKeever

    2011-01-01

    This chapter provides estimates of forest biomass and wood waste quantities, as well as roadside costs (i.e., supply curves) for each county in the contiguous United States. Roadside price is the price a buyer pays for wood chips at a roadside in the forest, at a processing mill location in the case of mill residue, or at a landfill for urban wood wastes prior to any...

  17. 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.

  18. Southern Woods-Burners: A Descriptive Analysis

    Science.gov (United States)

    M.L. Doolittle; M.L. Lightsey

    1979-01-01

    About 40 percent of the South's nearly 60,000 wildfires yearly are set by woods-burners. A survey of 14 problem areas in four southern States found three distinct sets of woods-burners. Most active woods-burners are young, white males whose activities are supported by their peers. An older but less active group have probably retired from active participation but...

  19. 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....

  20. Effects of decadal exposure to interacting elevated CO2 and/or O3 on paper birch (Betula papyrifera) reproduction.

    Science.gov (United States)

    Darbah, Joseph N T; Kubiske, Mark E; Nelson, Neil; Oksanen, Elina; Vapaavuori, Elina; Karnosky, David F

    2008-10-01

    We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO(2) and/or O(3) on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO(2) increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O(3) also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO(2)+O(3)) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO(2) may have a largely positive impact on forest tree reproduction and regeneration while elevated O(3) will likely have a negative impact.