Dissertations / Theses on the topic 'Hardwood'

Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains ix, 61 p. : ill. (some col.), col. map. Vita. Includes abstract. Includes bibliographical references (p. 28-30).

The primary goal of this study was to identify value added export opportunities for the hardwood products manufacturing industry. By studying current industry practices and trends, we can better understand the opportunities hardwood lumber businesses have exploited in the past and could do so today. The study found that opportunities exist for businesses with the right initial mindset preparing them for exporting, the proper equipment, and the appropriate educational experience. Surveys of hardwood lumber manufacturers in 1989 and 2002 addressed similar objectives and helped better understand export participation of hardwood lumber manufacturers in the Appalachian Region. The objectives of this research project included determining current export experience, access and use of export development programs, key export markets, and mill production, marketing, equipment, personnel and other attributes of the region's hardwood lumber industry. Other objectives included determining if any significant changes in the region's hardwood industry had occurred, and in particular, what was mill export market experience in the past 15 years. The key was to identify key factors that lead to export marketing participation. This study showed that export market participation is growing as forest sector businesses consolidated during this period. Businesses were found to seek assistance from multiple government agencies, trade associations, and most importantly from their customers. While the largest export market continues to be Canada, little information is available on other businesses purchasing Appalachian hardwood lumber, indicating the need for more research on markets and their size. Important species for exporting are red oak, yellow-poplar, white oak, and maple, and higher grades of hardwood lumber continue to be the top three. Owning a kiln is essential to exporting, and having an above average size marketing staff was found to be helpful. The most important attribute of exporters is an open-minded management that sees the benefits of exporting.
Master of Science

In order to gain insights into ultrastructural changes taking place during the conversion of hardwoods into mechanical pulps, refiner pulp fibres were studied in detail using several microscopical techniques. Aspen (Populus tremuloides Michx.) and white birch (Betula papyrifera Marsh.) wood chips were used to produce thermomechanical (TMP), chemithermomechanical (CTMP) and chemimechanical (CMP) pulps. Following the hypothesis that there are fundamental differences in the surface and state of the fibres due to species and processing conditions, four pulps for each species and process were analyzed. Trends in fibre characteristic development were obtained within each group, based on the detailed optical analysis of 300 fibre cross-sections for each pulp. Fibre surface quality was the most important aspect of this study. Retention of middle lamella and of the layer, as well as the extent of exposure of the S₂ layer were evaluated. It was found that TMP processing of wood chips produced fibres with more exposure of the S₂ layer. Chemical pretreatment did not improve the extent of S₂ layer exposure nor the extent of fibrillation. However, the TMP fibres remained stiff, producing pulp sheets of low density and strength. Birch fibres showed a marked tendency to produce separation at or near the S₁/S₂ boundary. This resulted in high exposure of S₂ layers in TMP fibres, but produced a sheath of S₁ and ML around fibres from chemically-treated chips. This sheath was sometimes rolled back, exposing the fibre S₂ layer. Aspen TMP pulps showed high proportions of fibres with partially exposed S₂ layer. The application of chemical pretreatments to aspen chips resulted in fibres of similar levels of S₂ exposure than those achieved by TMP processing of this species, but only after reaching freeness levels of about 100 mL CSF. Fibres that showed radial failure were frequent in TMP but not in CTMP nor CMP pulps. The breakdown pattern of tension wood fibres (G-fibres) was also studied. TMP processing showed preferential breakdown of G-fibres, from which the G-layers were freed. This was not the case in the G-fibres from chemically-treated chips, in which the G-layer generally remained inside the fibres. Other categories discussed in the analysis of fibre cross sections included fibres with delamination of the S₂ layer and proportion of fibres distorted due to chemical impregnation. The breakdown of vessel elements (VE) was studied by comparing VE size frequency distributions and the proportion of whole VE that survived refining. TMP reduced VE into small fragments showing virtually no whole VE, while wood softening due to chemical pretreatment was responsible for a high proportion of whole VE in CTMP and CMP pulps. The VE from birch tend to be destroyed more easily than those from aspen, due to the intervessel pitting arrangement of the former. It is concluded that despite superior bonding potential of TMP fibres due to: - large S₂ exposure in fibres on account of separation at or near the S₁/S₂ boundary, - increased fibrillation, - longer fibrils in fines, and - release and exposure of highly cellulosic G-layers from tension wood in the case of aspen, the lack of conformability of TMP fibres, which translates into low sheet density, negates the promising benefits that otherwise would be obtained.
Forestry, Faculty of
Graduate

A method is described for implementing group selection regeneration in Appalachian hardwoods. The diverse set of definitions of the method, and the current forest demands are combined to form a flexible system of implementation that can accommodate public as well as private forests. Group selection is used where an unevenâ aged silvicultural system is required and multiple objectives demanded. Several types of information are collected in a sample of the forest and then used to make the selection decision of which groups of trees to remove, and which groups to leave.

Master of Science

Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains viii, 59 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 49-52).

The Hardwood Industry in United States has been challenged by low-cost competition from overseas. Although cost reduction strategies have had minimal success, the proximity of industry to the domestic market has large implications on a more customer-focused strategy. The problem arises that individual companies and supply chains evolved based on the principles of economies of size and not on the flexibility to adapt to customer needs and changing resource constraints. An increased rate at which material and information flows through the hardwood supply chains is the key to the industriesâ ability to be customer-focused. Information systems may offer benefits for the industry, but changes in material flow of a company or supply chain cannot necessarily be predicted when implementing information systems. It was hypothesized that by understanding the dynamics between information flow and material flow throughout the supply chain, performance improvement would be possible through more effective release and use of information. A case study analysis of a hardwood supply chain was utilized to identify the effect of increased information flow on the material flow of the supply chain. Value Stream Mapping was utilized to benchmark the current state of lead times of information flow and material flow. System Dynamics was utilized to understand the relationships between the information flow and the material flow. Finally, simulations were performed to identify the specific effects on material flow as increased information flow is released through different information strategies. The study showed that increased information flow between supply chain members increased material flow through the supply chain. For a case study supply chain, an increase in information flow, through advanced knowledge of customer demand by a supplier, was found to reduce the inventory buffers throughout the supply chain by up to 38 percent and increase the total material flow through the supply chain by 10 percent. In addition to the increased information flow caused by the advanced knowledge of demand (18 percent), information flow would increase (by an additional 7 percent) based on the reductions in buffer inventory within each company of the supply chain.
Ph. D.

Pallet cant quality directly impacts pallet part processing and material costs. By knowing the quality of the cants being processed, pallet manufacturers can predict costs to attain better value from their raw materials and more accurately price their pallets. The study objectives were 1) to develop a procedure for accurately predicting hardwood pallet part yield as a function of raw material geometry and grade, processing equipment, and pallet part geometry, 2) to develop a model for accurately predicting raw material costs for hardwood pallet parts as a function of yield, 3) to examine current pallet industry methods of determining hardwood cant quality, and 4) to develop and evaluate hardwood cant grading rules for use in the pallet industry. Yield studies were necessary to accurately quantify the relationship between yield and cant quality. Thirty-one yield studies were conducted throughout the Eastern United States at pallet mills producing pallet parts from hardwood cants. 47, 258 board feet of hardwood cants were graded, and the usable pallet part yield and yield losses were determined for each grade. Yield losses were separated into three components: kerf loss, dimension loss, and defect loss. Kerf and dimension losses are a function of raw material and part geometry and were calculated without regard to cant quality. Defect loss is dependant on cant quality and was calculated for each cant grade as a function of total yield, kerf loss, and dimension loss. Mathematical models were developed from twenty-eight mill studies to predict each yield loss component as a function of cant dimensions, grade, and orientation, cutting bill parameters, pallet part dimensions, and kerf. Dimension and kerf losses were predicted geometrically. Regression analysis was used to predict defect loss. Results indicated that these models accurately predicted the total yield of usable pallet parts and pallet part material costs as a function of cant quality and price. Results also indicated that the pallet industry's current method of counting the number of "bad" ends per cant bundle to determine cant quality is not adequate. The effectiveness of the proposed cant grading rules was determined by grading cants and analyzing the cant grade distributions and corresponding pallet part yields. The grade rules produced statistically different quality divisions between grades. However, a more practical single cant grade based on the minimum quality for the proposed grade 2 rules is recommended.
Master of Science

I compared the interrelationships among traits affecting interspecific variation in the growth of seedlings of 22 hardwood tree species subjected to chronic intermittent drought. Leaf traits were the most responsive to contrasting water regimes; canopy architecture, hydraulic conductivity and leaf phenology were less affected. Relative growth rate (RGR) under drought, however, was most closely related to variation in canopy duration: species in leaf longer had greater RGR. Secondarily, maintaining higher stomatal conductance (g) under drought further enhanced RGR. Higher g is associated with a higher photosynthetic rate (A), but the relationship between A and g varied with internal CO$ sb2$ concentration (c$ sb{ rm i}$), foliar nitrogen and specific leaf mass. Species with weaker homeostatic control over c$ rm sb{i}$ had higher water use efficiency. While photosynthetic characteristics were related primarily to species' shade tolerance, water use efficiency was most closely related to habitat moisture preference.

En Amérique du Nord, la préférence pour la récolte des arbres vigoureux et de gros diamètre a amené les forêts feuillues à un état d’appauvrissement. Ces forêts sont composées de grandes quantités de tiges de faible qualité et d’essences moins prisées par l’industrie. Conséquemment, le secteur forestier doit composer avec une grande quantité de matière première de faible qualité, ce qui entraîne une augmentation des coûts d’opération et cause la production des forts volumes de résidus qui doivent être valorisés. Cette situation force l’industrie à rechercher des solutions pour l’utilisation de grandes quantités de bois de faible qualité abondamment disponibles en forêt afin d’augmenter la rentabilité de ses opérations. Une option serait de miser sur les produits de haute valeur ajoutée qui pourraient être extraits à partir des résidus des scieries. Ces produits incluent les extraits de bouleau jaune (Betula alleghaniensis Britt.), lesquels ont du potentiel pour l’utilisation dans les industries nutraceutique, cosméceutique et pharmaceutique. Les produits de haute valeur ajoutée, intégrés dans l’industrie des produits traditionnels, peuvent augmenter la rentabilité de la chaîne de valeur, surtout si les résidus sont utilisés comme matière première. Afin de comprendre le potentiel et les limites de cette approche, cette étude a évalué les facteurs qui influencent la valeur monétaire de sciage, proposant ensuite une utilisation alternative pour le bois de faible qualité et l’écorce provenant des forêts feuillues de la province de Québec au Canada. Cette étude a été structurée en trois parties : l’évaluation de la relation entre la valeur monétaire des sciages et les caractéristiques du peuplement, de la station et du climat; l’évaluation de la relation entre la quantité d’extraits de bois et d’écorce du bouleau jaune et des caractéristiques des arbres et; l’évaluation de l’inclusion d’un produit à haute valeur ajoutée dans la chaîne de création valeur. Dans la première partie, la valeur monétaire des sciages du bouleau jaune et de l’érable à sucre (Acer saccharum Marsh.) a été utilisée comme indicateur de la qualité du peuplement. Les résultats ont démontré que des patrons géographiques de variation de la valeur monétaire des sciages existaient à travers la province. Cette variation pourrait être attribuée en partie aux caractéristiques du peuplement, de la station et du climat local. Même s’il persiste de l’incertitude quant à l’effet de l’historique d’aménagement forestier, on croit que la production d’arbres de haute qualité devrait être priorisée aux endroits où la valeur monétaire des bois sur pied est la plus grande. Dans la deuxième partie, les analyses réalisées pour quantifier les extraits du bois et de l’écorce ont fourni une compréhension plus approfondie du potentiel du bouleau jaune pour les produits non traditionnels à haute valeur ajoutée. Dans la troisième partie, la rentabilité d’une coupe de jardinage a été évaluée, en plus du profit potentiel de production de la bétuline et l’inclusion de cet extrait dans la chaîne de valeur du bois. Dans certains cas, la coupe de jardinage a été très peu rentable, surtout lorsqu’appliquée dans les peuplements qui étaient composés des grandes quantités de tiges de faible qualité. Dans de tels cas, les produits à haute valeur ajoutée, comme la bétuline, pourraient augmenter les profits et, par le fait même, ajouter de la valeur à la ressource forestière. La diversification des produits est une approche qui pourrait être envisagée par l’industrie forestière pour augmenter sa résilience et promouvoir une sylviculture respectant les règles de l’art.
En Amérique du Nord, la préférence pour la récolte des arbres vigoureux et de gros diamètre a amené les forêts feuillues à un état d’appauvrissement. Ces forêts sont composées de grandes quantités de tiges de faible qualité et d’essences moins prisées par l’industrie. Conséquemment, le secteur forestier doit composer avec une grande quantité de matière première de faible qualité, ce qui entraîne une augmentation des coûts d’opération et cause la production des forts volumes de résidus qui doivent être valorisés. Cette situation force l’industrie à rechercher des solutions pour l’utilisation de grandes quantités de bois de faible qualité abondamment disponibles en forêt afin d’augmenter la rentabilité de ses opérations. Une option serait de miser sur les produits de haute valeur ajoutée qui pourraient être extraits à partir des résidus des scieries. Ces produits incluent les extraits de bouleau jaune (Betula alleghaniensis Britt.), lesquels ont du potentiel pour l’utilisation dans les industries nutraceutique, cosméceutique et pharmaceutique. Les produits de haute valeur ajoutée, intégrés dans l’industrie des produits traditionnels, peuvent augmenter la rentabilité de la chaîne de valeur, surtout si les résidus sont utilisés comme matière première. Afin de comprendre le potentiel et les limites de cette approche, cette étude a évalué les facteurs qui influencent la valeur monétaire de sciage, proposant ensuite une utilisation alternative pour le bois de faible qualité et l’écorce provenant des forêts feuillues de la province de Québec au Canada. Cette étude a été structurée en trois parties : l’évaluation de la relation entre la valeur monétaire des sciages et les caractéristiques du peuplement, de la station et du climat; l’évaluation de la relation entre la quantité d’extraits de bois et d’écorce du bouleau jaune et des caractéristiques des arbres et; l’évaluation de l’inclusion d’un produit à haute valeur ajoutée dans la chaîne de création valeur. Dans la première partie, la valeur monétaire des sciages du bouleau jaune et de l’érable à sucre (Acer saccharum Marsh.) a été utilisée comme indicateur de la qualité du peuplement. Les résultats ont démontré que des patrons géographiques de variation de la valeur monétaire des sciages existaient à travers la province. Cette variation pourrait être attribuée en partie aux caractéristiques du peuplement, de la station et du climat local. Même s’il persiste de l’incertitude quant à l’effet de l’historique d’aménagement forestier, on croit que la production d’arbres de haute qualité devrait être priorisée aux endroits où la valeur monétaire des bois sur pied est la plus grande. Dans la deuxième partie, les analyses réalisées pour quantifier les extraits du bois et de l’écorce ont fourni une compréhension plus approfondie du potentiel du bouleau jaune pour les produits non traditionnels à haute valeur ajoutée. Dans la troisième partie, la rentabilité d’une coupe de jardinage a été évaluée, en plus du profit potentiel de production de la bétuline et l’inclusion de cet extrait dans la chaîne de valeur du bois. Dans certains cas, la coupe de jardinage a été très peu rentable, surtout lorsqu’appliquée dans les peuplements qui étaient composés des grandes quantités de tiges de faible qualité. Dans de tels cas, les produits à haute valeur ajoutée, comme la bétuline, pourraient augmenter les profits et, par le fait même, ajouter de la valeur à la ressource forestière. La diversification des produits est une approche qui pourrait être envisagée par l’industrie forestière pour augmenter sa résilience et promouvoir une sylviculture respectant les règles de l’art.
The historical preference for harvesting vigorous and large-diameter trees from stands in North America resulted in a forest mainly composed of poor-quality stems of less valuable species that present lower growth potential. As a result, the forestry sector has to work with large quantities of low-quality raw material, increasing operation costs and producing large amounts of residues. This situation forces the industry to find solutions to use the abundant quantity of low-quality wood available in forest stands to increase profits. One option is the high value-added products that could be extracted from sawmill residues. These products include yellow birch (Betula alleghaniensis Britt.) extracts that have the potential to be used in the nutraceutical, cosmeceutical and pharmaceutical industries. The enhanced products, when integrated with the traditional products industry, could increase profit of the wood value chain, especially if residues are used as raw material. In order to better understand the potential and limitations of this option, this study assessed the factors that influence lumber value, and proposed an alternative use for the abundant low-value wood and bark available in the province of Quebec, Canada. Structured in three parts, this work first studied the relationship between stand, site and climatic variables and stand quality, using lumber value recovery (LVR) of sugar maple (Acer saccharum Marsh.) and yellow birch as surrogate variable. In the second part, the relationship between extracts content in wood and bark of yellow birch trees with selected tree characteristics was assessed. This allowed a better understanding of the potential of yellow birch extracts as a high-value added product. In the third and final part, the potential impact of integrating a high-value added product to the processing of traditional wood products was evaluated. For this, the profitability of a selection cut was analysed, the potential financial gain of producing betulin extract was assessed, and finally, the inclusion of betulin extracts in a hardwood chain was evaluated. Results from the ensemble of this thesis show that variations in LVR could be attributed to in part to stand, site and climatic conditions. Although it remains uncertain as to what extent the variability of LVR might result from past management practices or from inherent site characteristics, we believe that efforts to produce high-quality lumber should be prioritized in sites where LVR is predicted to be the highest. In addition, simulations showed that tested selection cuts in some cases generated very little profit, especially when forest stands were composed of great quantities of low-quality stems. In this situation, the production of high value-added products, such as betulin extracts, could be an interesting alternative to increase profits, contributing to add value to the existing forest resource. The product diversification is a pathway that could be explored by the forest industry to improve its resilience and promote a more efficient use of the resources.
The historical preference for harvesting vigorous and large-diameter trees from stands in North America resulted in a forest mainly composed of poor-quality stems of less valuable species that present lower growth potential. As a result, the forestry sector has to work with large quantities of low-quality raw material, increasing operation costs and producing large amounts of residues. This situation forces the industry to find solutions to use the abundant quantity of low-quality wood available in forest stands to increase profits. One option is the high value-added products that could be extracted from sawmill residues. These products include yellow birch (Betula alleghaniensis Britt.) extracts that have the potential to be used in the nutraceutical, cosmeceutical and pharmaceutical industries. The enhanced products, when integrated with the traditional products industry, could increase profit of the wood value chain, especially if residues are used as raw material. In order to better understand the potential and limitations of this option, this study assessed the factors that influence lumber value, and proposed an alternative use for the abundant low-value wood and bark available in the province of Quebec, Canada. Structured in three parts, this work first studied the relationship between stand, site and climatic variables and stand quality, using lumber value recovery (LVR) of sugar maple (Acer saccharum Marsh.) and yellow birch as surrogate variable. In the second part, the relationship between extracts content in wood and bark of yellow birch trees with selected tree characteristics was assessed. This allowed a better understanding of the potential of yellow birch extracts as a high-value added product. In the third and final part, the potential impact of integrating a high-value added product to the processing of traditional wood products was evaluated. For this, the profitability of a selection cut was analysed, the potential financial gain of producing betulin extract was assessed, and finally, the inclusion of betulin extracts in a hardwood chain was evaluated. Results from the ensemble of this thesis show that variations in LVR could be attributed to in part to stand, site and climatic conditions. Although it remains uncertain as to what extent the variability of LVR might result from past management practices or from inherent site characteristics, we believe that efforts to produce high-quality lumber should be prioritized in sites where LVR is predicted to be the highest. In addition, simulations showed that tested selection cuts in some cases generated very little profit, especially when forest stands were composed of great quantities of low-quality stems. In this situation, the production of high value-added products, such as betulin extracts, could be an interesting alternative to increase profits, contributing to add value to the existing forest resource. The product diversification is a pathway that could be explored by the forest industry to improve its resilience and promote a more efficient use of the resources.

A computerized system for planning timber harvest to maximize habitat quality over time for a specified group of wildlife species was developed for upland oak forests of the Eastern United States. This system, called WILDWOOD for WILDiife/WOOD optimization system, is designed to run on a microcomputer. It utilizes a widely available database management system called PCFile III, Version 4, a forest growth and yield simulator adapted from work by Dale (1972), and a program developed by the author. The system utilizes 43 species-specific habitat value models developed by the author and others. Timber harvests in approximately one ha blocks (patch clearcut) are specified for each year to result in a maximum yearly average wildlife benefit figure. Wildlife benefits are defined as the product of a wildlife species value provided by the user, a forest-size-classspecific habitat value index, and the area of the cutting unit. WILDWOOD was demonstrated on a 106 ha tract of upland oak forest on Havens Wildlife Management Area of the Virginia Commission of Game and Inland Fisheries. Six different objective functions were investigated and several model tests were conducted. Implications for the application of the WILDWOOD system were discussed, and it was concluded that, although the objectives of the study were met, the current WILDWOOD system should be modified to include smooth wildlife habitat succession models, at least a 150-year planning horizon, and capabilities for addressing cutting unit size, shape, and juxtaposition. Other possibilities for future revisions inclu~e modifying HEP (U.S. Fish and Wildlife Service) for use with WILDWOOD, and linking ageographic information system to WILDWOOD.
Master of Science

Little is known about the original properties of soils in the East. Eight virgin soils and associated southern Appalachian hardwood vegetation were studied in western North Carolina. The study sites ranged in elevation from 720 to 1200 m on steep slopes. Overall these soils are quite deep and highly weathered due to high rainfall (>200 cm) and soluble feldspathic parent material. Organic matter contents of the surface·horizons were quite high (4.5 - 16 %), and they contained moderate to strong crumb structure. All but one soil contained cambic subsurface horizons and were either Typic Haplumbrepts or Umbric Dystrochrepts. The majority of soils in the watershed are formed in colluvium, but significant amounts of residual soils occur on sideslopes, and appear to be quite stable. The present day landforms appear to be the result of periglacial activity. North-facing soils were higher in whole soil clay, organic matter, and A horizon exchangeable cations than south-facing soils. Cation exchange capacity in these soils is almost totally dependent on organic matter content, and the mineral fraction is relatively inert. All soils were in the oxidic mineralogy class. Bibbsite was common throughout all soils and hydroxy-interlayered vermiculite (HIV) is the dominant clay-sized phyllosilicate in surface horizons. Kaolinite was low in all soils, but was more abundant on south-facing slopes. The silt fractions and sand fractions contained significant quantities of weathered 2:1-type minerals The vegetation varied from mixed-mesophytic cove hardwoods on north-facing slopes to mixed oak-hickory and oak-pine on south-facing slopes. Many trees in coves exceed 1.3 m in diameter and 50 m in height. Total litter production averaged 3494 kg/ha, and the litter layers were typified by thin leaf (L), and well developed fermentation (F) and humus (H) layers. Cations and P are concentrated in the litter layers and immediate surface soil, while N is mixed deep into the profile. Due to their oxidic mineralogy, low CEC, decreasing clay content with depth, and concentration of cations and P in litter and standing biomass these soils highly resemble tropical Oxisols.
Ph. D.

In this thesis, a coupled heat and mass transfer and drying stress failure model was developed to predict vacuum and conventional drying behaviour of Australian hardwoods. The method was based on extensive measurement of key model parameters that were used as input data for the Multiphysics and finite element analysis models and then validated against semi-industrial drying trials. The research outcomes provide the Australian hardwood industry with a tool that can be used to reduce current drying time, costs and waste due to drying degradation.

This research examines the drying of hardwood timber with particular reference to seasoning blackbutt (Eucalyptus pilularis) in a solar kiln. The aims of this research were to develop an optimised drying schedule for drying blackbutt and to develop and validate a mathematical model for a solar kiln. In the first stage of this study, the cross-grain physical and mechanical properties were determined for blackbutt timber so that an optimised schedule (based on drying within a limiting strain envelope) can be developed using model predictive control techniques for drying 43 mm thick (green) blackbutt timber boards in solar kilns. This optimised schedule has been developed and tested in the laboratory. The drying time was 10% shorter for this schedule than the original schedule, compared with an expected reduction in drying time of 14% (relative to the original schedule). Overall the quality was slightly better and the drying time was shorter for the optimised schedule compared with the original schedule. A complete solar kiln model has been developed and validated based on comparisons between the predicted and the measured internal air temperatures, relative humidities and timber moisture contents. The maximum difference between the actual and predicted moisture contents was 0.05 kg/kg. The agreement between the predicted and measured temperatures of the internal air is reasonable, and both the predictions and measurements have a similar cyclical pattern. The generally good agreement between the model prediction of the final moisture content and its measurement may be due to the careful measurement of the boundary conditions such as the solar energy input. The key uncertainties were identified as the heat exchanger output, the measurement of the initial moisture content, the amount of accumulation of condensate on the floor, and the estimation of sky temperature. The significant uncertainty (18%) in the estimation of the initial moisture content is a key reason for the mismatch between the model prediction and the measurements. In terms of operating variables, the energy release rate from the heat exchanger had the greatest effect on the simulated performance, followed by the water spray and venting rates. The simulation suggested that a material with a lower transmissivity to thermal radiation may effectively lower radiation losses, improving the kiln performance, so such materials for glazing is a high priority.

This research examines the drying of hardwood timber with particular reference to seasoning blackbutt (Eucalyptus pilularis) in a solar kiln. The aims of this research were to develop an optimised drying schedule for drying blackbutt and to develop and validate a mathematical model for a solar kiln. In the first stage of this study, the cross-grain physical and mechanical properties were determined for blackbutt timber so that an optimised schedule (based on drying within a limiting strain envelope) can be developed using model predictive control techniques for drying 43 mm thick (green) blackbutt timber boards in solar kilns. This optimised schedule has been developed and tested in the laboratory. The drying time was 10% shorter for this schedule than the original schedule, compared with an expected reduction in drying time of 14% (relative to the original schedule). Overall the quality was slightly better and the drying time was shorter for the optimised schedule compared with the original schedule. A complete solar kiln model has been developed and validated based on comparisons between the predicted and the measured internal air temperatures, relative humidities and timber moisture contents. The maximum difference between the actual and predicted moisture contents was 0.05 kg/kg. The agreement between the predicted and measured temperatures of the internal air is reasonable, and both the predictions and measurements have a similar cyclical pattern. The generally good agreement between the model prediction of the final moisture content and its measurement may be due to the careful measurement of the boundary conditions such as the solar energy input. The key uncertainties were identified as the heat exchanger output, the measurement of the initial moisture content, the amount of accumulation of condensate on the floor, and the estimation of sky temperature. The significant uncertainty (18%) in the estimation of the initial moisture content is a key reason for the mismatch between the model prediction and the measurements. In terms of operating variables, the energy release rate from the heat exchanger had the greatest effect on the simulated performance, followed by the water spray and venting rates. The simulation suggested that a material with a lower transmissivity to thermal radiation may effectively lower radiation losses, improving the kiln performance, so such materials for glazing is a high priority.

The objective of this thesis was to understand the spatial patterns and processes responsible for canopy and understorey spider (Arachnida: Araneae) diversity at multiple spatial scales in north-temperate hardwood forests. I sampled tree trunks (sticky traps) and foliage (beating) of sugar maple and American beech tree canopies and their understorey saplings in old growth forests near Montreal, Quebec. Results show the composition of canopy and understorey assemblages differed significantly, and so did sugar maple and American beech canopy assemblages. Each stratum was also dominated by different species. The rank-abundance distribution of species from each habitat wsa also verticaly stratified because it fit different distribution models. Different factors likely structure assemblages in both habitats, particularly since the canopy is a less stable environment. Spiders from canopy and understorey foliage were tested in a laboratory for their propensity to balloon. General linear models indicated that small sized web-building spiders of the RTA and Orbicularia clades have the highest propensity to balloon. Small bodied species initiated ballooning regardless of the habitat they were collected in or their developmental stage. My results support the mixed evolutionarily stable strategy theory and indicate the absence of risk-spreading in the dispersal strategy of canopy spiders. My last chapter focused on dispersal capacity and diversity patterns of spiders at multiple spatial scales. Analyses of the species diversity of limited and high dispersal capacity species subsets through nested-multivariate ANOVA, additive diversity partitioning, and species-abundance distribution curves all point towards species-sorting processes as the main driver of local community spider diversity at the tree and stand spatial scales. Mass-effects and patch-dynamic processes drive site and regional scale diversity patterns. This thesis demonstrates that spiders provide good models to test many biological hypotheses. The research chapters of this thesis test hypotheses on the vertical stratification of forest spider diversity, the evolution of local dispersal adaptations, and the importance of dispersal capacity on species diversity patterns through a metacommunity framework.

Given the overexploitation of indigenous forests and inadequate regeneration programmes in Peninsular Malaysia there is concern about the long term availability of both export grade timber species and low grade timber for domestic consumption. Therefore heartwood samples from seven species with commercial potential, (kapur (Dryobalanops aromatica Gaertn. f); kempas (Koompassia malaccensis Maing. ex Benth); keruing (Dipterocarpus spp.); mersawa (Anisoptera spp.); punah (Tetramerista glabra Miq.); rubberwood (Hevea brasiliensis Muell.-Arg) and simpoh (Dillenia spp.)) but about which there exists little objective information were evaluated in terms of their preservation characteristics. The species' inherent structural limitations to impregnation were water-borne copper-chrome-arsenic (CCA) preservatives were identified through the use of both optical and scanning electron microscopy. Samples of each species were evaluated for their amenability to fluid impregnation through the use of a novel technique which allowed for the direct and continuous measurement and observation of fluid uptake throughout a controlled vacuum-pressure treatment cycle. The technique provided quantitative data on species amenability to impregnation and also allowed for the determination of optimum process duration. The evaluation of preservative active ingredient distribution in treated samples was determined qualitatively through the use of colorimetric reagents and scanning electron microscopy energy dispersive X-ray microanalysis and quantitatively through the use of X-ray fluorescence spectrophotometric analysis. These studies highlighted preservative distribution problems in several of the species examined most notably kapur, kempas, rubberwood and mersawa.

In this thesis, the behaviour of glued laminated timber combined with hardwood and softwood lamallae is investigated. The influence of hardwood in the tension and compression zone, in terms of strength and stiffness is evaluated.The basis of evaluation consists of determining the behaviour of beams with various combinations of hardwood solely in the tension zone along with beams with hardwood in the tension and compression zone. The influence of different amount of hardwood for both cases is studied my means of experimental and analytical methods.Experimental data attained by performing bending tests are evaluated for different combinations made from spruce and oak. By comparing the experimental and analytical data an increase in the strength and stiffness in various combinations is observed and potrayed which varies based on different wood species.

In kraft pulping, one of the main issues is the extensive wood losses. With increasing prices ofwoody biomass an incentive towards minimizing the wood losses exists. Amongst the variousprocess steps, the impregnation of wood chips has shown to enhance the cooking by providinga homogeneous distribution of chemicals inside the chips. It is proven that a more proficientimpregnation phase can improve the overall yield in kraft pulping. However, there is a lack ofscientific research comparing different impregnation techniques for hardwood. Hence, thisthesis will attempt to clarify the impregnation of hardwood.The impregnation efficiency was studied by comparing three different impregnation methods:High Alkali Impregnation (HAI), Extended Impregnation (EI) using a low alkali level and aReference Impregnation (REF) to enable a comparison to the industrially establishedconditions. The cases were compared by analysing the yield, selectivity and homogeneity. Thecomparison was also made under cooking conditions with the objective to understand theimpact of impregnation on the subsequent cooking phase. The cooking procedure was assessedby analysing the degree of delignification, yield and reject content.In impregnation, most chemical consuming reactions occurred within the first 10-30 minutes,mainly contributed by deacetylation. HAI obtained the fastest homogeneous distribution of OH-(~60 min), but the fastest dissolution of wood. The effect was contributed by the high [OH-],providing fast diffusion of ions and rapid dissolution of xylan. In the contrary, EI attained thehighest impregnation yield after a given impregnation time but required a prolonged durationto obtain a chemical equilibrium between the free and bound liquor (~120 min). REF showeda higher yield than HAI and similar chemical equilibrium as EI. The hydrosulphide sorption inimpregnation was highest for EI due to the high initial sulphidity charge and similar for REFand HAI. For impregnations at 115°C, the HS- sorption was significantly increased for all cases,resulting from delignification. In the subsequent cooking phase, it was prevalent that impregnation of chips under EIconditions were easier delignified, leading to a reduced cooking time to reach the defibrationpoint. Birch was more prone to delignification than eucalyptus. In turn, eucalyptus also obtaineda higher defibration point. Highest total cooking yield at similar kappa numbers was achievedwith REF conditions, followed by HAI and lastly the EI conditions. The high yield of REF incontrast to HAI could be explained by an improved xylan yield due to an alleviated hydroxidelevel. The low yield of EI can be assigned to continues peeling due to the prolongedimpregnation and loss of xylan when removing black liquor after impregnation. In terms ofproduction rate, yield, energy and chemical consumption the REF is the most efficientimpregnation condition for birch kraft cooking in this batchwise laboratory kraft cookingprocedure.
Ett av de största problemen vid massaframställning med sulfatprocessen är de stora förlusterna av råmaterial. Med stigande priser på träbiomassa finns ett incitament att minimeraträförlusterna. Bland de olika processtegen har impregneringen av träflis visat sig förbättrakokningen genom att tillföra en homogen fördelning av kemikalier inuti flisen. Det är bevisatatt en väl genomförd impregneringsfas kan förbättra det totala utbytet vid massakokning. Dockfinns det en brist på vetenskaplig forskning som jämför olika impregneringstekniker för lövved. Därav kommer detta arbete att försöka förtydliga impregneringen av lövved. Impregneringseffektiviteten studerades genom att jämföra tre olika impregneringsmetoder:High Alkali Impregnation (HAI), Extended Impregnation (EI) med låg alkalinivå ochreferensimpregnering (REF) för att möjliggöra en jämförelse med de industriellt etableradeförhållandena. Impregneringsteknikerna jämfördes genom att analysera utbytet, selektivitetenoch homogeniteten. Jämförelsen utfördes även under kokningsförhållanden med målet att förståhur impregneringseffekten påverkar det efterföljande kokningssteget. Kokningen bedömdesgenom att analysera ligninnivån, utbytet och spetinnehållet. Under impregneringsförsöken inträffade de flesta kemikaliekonsumerande reaktionerna inom10–30 minuter, främst bidragen av deacetyleringsreaktioner. HAI erhöll den snabbastehomogena fördelningen av OH- (~ 60 min), dock med konsekvensen att snabbast upplösaträmaterialet. Effekten bidrogs av den höga [OH-], vilket gav snabb diffusion av joner och snabbupplösning av xylan. EI erhöll det högsta impregneringsutbytet efter en given impregneringstidmen krävde en förlängd uppehållstid för att erhålla en kemisk jämvikt mellan den fria ochbundna vätskan (~ 120 min). REF visade ett högre utbyte än HAI och liknande kemisk jämviktsom EI. Sorption av vätesulfidjoner vid impregnering var högst för EI på grund av den högainitiala svavelhalten följt av REF och till sist HAI. För impregnering vid 115°C ökade HSupptagetbetydligt för alla metoder, orsakad av delignifiering.I den efterföljande kokningsfasen var det framträdande att impregneringen av flis under EIförhållandenlättare delignifierades, vilket resulterade i en reducerad kokningstid för att nådefibreringspunkten. Björk var mer benägen att delignifieras än eukalyptus. I sin tur fickeukalyptus även en högre defibreringspunkt. Högsta totala kokningsutbytet vid snarlika kappataluppnåddes med REF-förhållandet, följt av HAI och slutligen EI. Det höga utbytet av REFjämfört med HAI kunde förklaras av ett förbättrat xylanutbyte på grund av den lägrehydroxidnivån. Det lägre utbytet av EI kan förklaras på grund en större utsträckning av peelingreaktionpå grund av den förlängda impregneringen och förlust av xylan vid avlägsnande avsvartlut efter impregneringen. Sammanfattningsvis, i termer av produktionshastighet, utbyte,energi och kemikalieförbruk var REF den mest effektiva impregneringsmetoden vidmassatillverkning av björk i denna studie.

Repeated partial cutting in the Appalachian hardwood region has often favored the development of tolerant species like American beech (Fagus grandifolia Ehrh.) and stands with a high proportion of cull trees. Crop tree release is a widely recommended practice to improve species composition and growth rates in these unevenaged structured stands. Chemical control offers some distinct advantages from the standpoint of safety and residual stand damage, over mechanical methods. Control of American beech was the primary focus of this study. Beech is a low value timber tree, normally considered difficult to control. It is a major competitor to more valuable trees, especially on better sites in the Appalachians.

Research plots were established in hardwood stands at three sites in central West Virginia to evaluate the effectiveness of glyphosate (Accord), imazapyr (Arsenal AC and Chopper), and triclopyr (Garlon 3A and Garlon 4) using the hack-and-squirt application method and low volume basal spray treatments. In the injection treatments .051 fl oz (1.5 ml) of solution was used per inch of diameter (dbh). The basal spray treatments used 0.101 fl oz (3 ml) of solution per inch of diameter. The following concentrations were used: Accord (65.2%), Arsenal AC (7.5%), Garlon 3A (50%), Garlon 4 (26.25%), and Chopper (6.25% ). These concentrations were determined by using the highest costing injection and basal treatment at the lowest recommended labeled rate as standards, Garlon 3A and Chopper respectively. Eighteen 0.1 acre plots were systematically located at each study site where crop trees were present and to maximize the number of American beech on each plot. Crop trees, mostly black cherry (Prunus serotina Ehrh.) were chosen on a 0.025 acre subplot established at each plot center. All beech two inches and larger on the 0.1 acre plots and competing trees touching crop trees were treated in June 1998. The treatments were evaluated in September of 1998 and again in June of 1999. A numerical rating system ranging from 1-7, (0-100% crown affected), which utilized visual symptoms, was used to evaluate the efficacy of each treatment. Trees receiving a rating of 5 (75 % crown control) or greater were considered controlled. The relationship between the kinds of herbicide, application method, and numerical rating were analyzed by means of one-way analysis of variance with an incomplete random factorial design.

The most effective treatments for the three month evaluations were the Accord and Garlon 3A injection treatments. Average beech crown control ranged from 95-99% for Accord to 96-99% for Garlon 3A across all study sites. The basal spray treatments were not effective. Average crown control ranged from 1-22%, across all study sites. Accord, Garlon 3A, and Arsenal AC were the most effective treatments for the 12 month evaluations, with average beech crown control ranging from 99-100% across all study sites. The imazapyr treatments (Arsenal Ac and Chopper) had adverse effects on the crop trees and are not recommended for hardwood crop tree release. The cost effectiveness based on treatment costs and the amount of basal area (BA) controlled were averaged for all study sites. The average treatment costs based on the 12 month evaluations expressed in dollars/ft2 BA controlled were as follows: Accord ($0.91), Garlon 3A ($1.04), Arsenal AC ($0.84), Garlon 4 ($15.09), and Chopper ($7.74). NE-TWIGS was used to predict future composition and value of the projected stands. The stem injection treatments decreased the amount of beech and increased the amount of black cherry sawtimber thereby dramatically increasing the future value of the stands. Real rates of return were calculated for the stem injection (8.81%) and low-volume basal spray (-0.81%).
Master of Science

The objectives of this project were:
1.����To compare the drying cost and drying time for oak and poplar pallets for the following mold mitigation strategies for hardwood pallets: air drying, forced air drying (fan shed), kiln drying to 25% moisture content and chemical treatment, and
2.����Develop and evaluate a procedure for preventing and controlling mold growth on heat treated hardwood pallets
Twenty red oak pallets and twenty yellow-poplar pallets were tested for each drying method to compare costs and to determine drying times. �Additional pallets were obtained to conduct a more thorough air drying procedure. �Drying data was extrapolated to allow estimates of the drying time from green (83% moisture content for poplar and 64% moisture content for oak) to 25%. �
After the pallets reached the desired 25% moisture content, they were placed in a 40�" enclosed trailer, inoculated with mold (Aspergillus, Stachybotrys, and Penicillium) and were left undisturbed for a period of 14 days. �After the 14 day incubation period, the pallets were inspected for mold using the ASTM D-4445 Standard Test Method for Fungicides for Controlling Sapstain and Mold on Unseasoned Lumber. �
A comparison of drying costs was then conducted to determine which method was the most cost efficient based on the data obtained in this study. �The cost to treat the pallets with each treatment was calculated including electrical cost, labor, and tax values. �In addition to the cost comparison, a Net Present Value (NPV) was calculated to determine which method produced the best outcome over a longer period of time.
Two heat treatment and drying schedules were then developed to meet both IPPC-ISPM #15 requirements and achieve the desired 25% moisture content with minimal degrade. �This was accomplished by testing several HT/drying schedules on green yellow-poplar and white oak pallets until the pallets met the criteria for being heat treated and had minimal degrade. �The schedules developed are a modified oak HT/KD schedule that required 30 hours to complete and a modified poplar HT/KD schedule that required 16 hours to complete.
The results demonstrated that that mold would not grow on the pallets stored in an enclosed container when the dew point is not reached. Air-drying pallets, chemical application in conjunction with air-drying pallets, fan shed drying pallets and kiln drying pallets to a 19-24% moisture content was demonstrated to prevent mold growth on oak and yellow poplar pallets. Estimates for the time required to dry yellow-poplar and oak pallets to 19% and 25% moisture content were developed for air-drying, forced air-drying and kiln drying for the conditions experienced in Blacksburg, VA between 7/30/2008 and 11/10/2008. Air-drying pallets was found to have the lowest daily operational cost but not the lowest total drying cost. �Fan shed drying had the lowest drying cost to achieve 25% moisture content. �Kiln drying was the most expensive daily and total cost, but yielded the fastest method of drying pallets to 25% moisture content. A NPV cost comparison showed that over a 3 year (36 month) time period, fan shed drying is the most cost effective method of drying pallets based on the values used in this study. Given the environmental conditions experienced between 7/30/2008 and 11/10/2008, no mold grew on the air-dried, fan shed, and kiln dried pallets during the drying process.

Master of Science

Thesis (Ph. D.)--West Virginia University, 2005
Title from document title page. Document formatted into pages; contains ix, 144 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 107-114).

The diversity of saproxylic Cecidomyiidae (Diptera) associated with decaying logs was studied in an old-growth forest on Mont Saint-Hilaire, Quebec from June until September 2004. More than 24 000 specimens representing 323 species and morphospecies were collected in emergence traps set over American beech or sugar maple logs in two different stages of decay. The paedogenic species Miastor metraloas Meinert was by far the most numerous species with 17 002 individuals and was excluded from further analyses. Most of the remaining species were fungivores, detritivores or predators. Significantly more specimens were collected in logs in the more advanced decay stage, and indicator species analysis showed that the most abundant species were associated with this decay stage. Overall species richness was not significantly different between decay stages or tree species; however, non-metric multidimensional scaling indicated that the species assemblages associated with decay stage and tree species were significantly different despite the similar species richness.

Trees in silvopastures may provide forage-livestock systems with multiple goods and services, including shade, shelter, and browse. Reports of forage and animal productivity from these systems indicate that, in some cases, animal gains are similar or better despite lower forage yield. The relationship between grazing system, body temperature, grazing behavior, and animal performance was explored in this study. Black walnut and honeylocust-based silvopasture systems were compared with open pastures in a randomized complete block design (r = 3) over three summers. Pastures were rotationally stocked with 5-7 lambs depending on forage availability. Lambs were weighed every four weeks. Behavior measures were recorded within a replicate within a week, and these measures were taken sequentially within three experimental periods. Ewe lambs (n = 3) were equipped with a vaginal temperature sensor (3 days) and an audio recording device (1 day) to detect prehension events. Cameras documented lamb behavior every 60 seconds. Forage measurements taken with a rising plate meter indicated greater productivity in the honeylocust silvopasture (5020 ± 30 kg · ha⁻¹ ) compared to the open pasture (4930 ± 30 kg · ha⁻¹ ; P = 0.0281), though forage availability in the black walnut silvopastures (3560 ± 30 kg · ha⁻¹ ) was lower than within the other treatments (P < 0.0001). There was no difference in animal gains between systems (P ≥ 0.4813), though gains were highest in the honeylocust silvopastures (25.6 ± 3.4 kg · period⁻¹ ), followed by the gains of the black walnut silvopastures (22.3 ± 3.4 kg · period⁻¹ ), and the gains of the open pastures (22.2 ± 3.4 kg · period- 1 ). Lambs in silvopastures spent more time lying down than animals in the open pastures (P ≤ 0.01), while lambs in the open spent more than two hours longer each day standing (P < 0.0001). During the hottest part of the day, ewes in the open pasture were 0.4 °C hotter than ewes in the black walnut silvopastures (P ≤ 0.0202). Lambs in the black walnut silvopastures grazed more (488 ± 14 minutes · day⁻¹ ) than lambs in the honeylocust silvopastures (438 ± 15 minutes · day⁻¹ ; P = 0.0192) and the open pastures (417 ± 14 minutes · day⁻¹ ; P = 0.0009), with no difference between the latter two systems (P = 0.3073). There was no difference in daily bites taken (P ≥ 0.7222), though lambs in the silvopastures grazed more frequently than lambs in the open pastures. In one six week winter grazing study, animal performance in the honeylocust silvopastures was compared with the productivity of lambs grazing the open pastures and the black walnut silvopastures. The objective of this study was to determine the effect of these pods on lamb growth when animals grazed stockpiled tall fescue (Schedonorus arundinaceus). Preand post-graze forage mass was estimated with a double sampling technique using a rising plate meter. Treatment pastures were rotationally stocked with three (walnut) or six lambs per experimental unit depending on forage availability. Fescue grab samples were collected every other rotation. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and total digestible nutrients (TDN) were estimated with a robust equation using NIR spectroscopy. Pre- and post-graze pod mass per hectare was estimated using randomly placed quadrats. Lambs were naïve to pods and did not readily consume the fodder until four weeks into the trial, and the methods for estimating pod intake were not sufficient to detect pod differences in pre- and post-graze pod mass. Forage availability in the honeylocust silvopastures (5130 ± 90 kg · ha⁻¹ ) and open pastures (5050 ± 90 kg · ha⁻¹ ; P=0.7580) was greater (P < 0.0001) than forage availability in the black walnut silvopastures (3790 ± 90 kg · ha⁻¹ ). Treatment had no effect (P = 0.3763) on average daily gains across the six weeks of the study. However, lambs within the honeylocust silvopastures had greater (P = 0.0251) average daily gains in the final period (0.12 ± 0.02 kg · day⁻¹ ) than lambs within the open pastures (0 ± 0.02 kg · day⁻¹ ), and lambs were observed consuming the pods. These data suggest that honeylocust pods may support greater gains of lambs, but that previous exposure and longer study periods in pasture settings may be necessary to see their nutritional benefit when grazing high quality forages.
Ph. D.

A nation-wide survey of hardwood flooring manufacturers was conducted in the spring of 1998. The objectives of the study were to determine the differences in beliefs towards certification between certified and non-certified hardwood flooring manufacturers and to explore the decision to certify and the implications of that decision. Those objectives were chosen because certification is a developing phenomenon of which there are some aspects that remain unknown. The survey consisted of a mail questionnaire that was sent to more than 250 hardwood flooring manufacturers. The questionnaire was used to collect demographic and attitudinal information from the respondents about certification. The second part of the research used the Analytic Hierarchy Process to model the decision process hardwood flooring manufacturers go through when deciding whether or not to certify. Data were collected as part of the mail questionnaire. The final goal of the research, to explore the experiences of certified manufacturers, was met through the use of personal interviews with the manufacturers. The results from the mail survey indicated that certified hardwood flooring manufacturers tended to be smaller than non-certified hardwood flooring manufacturers. The total amount of certified hardwood flooring produced in the U.S. in 1997 was estimated to be 435,579 bdft, roughly 0.1% of the total reported amount of hardwood flooring produced. The research also indicated that certified manufacturers felt that there was a need for certification in the U.S. and that it was the environmentally responsible thing to do, while the non-certified manufacturers felt that that was untrue. The most important factor in the non-certified manufacturers' decision whether to certify is the profit potential of the product, while the certified manufacturers based their decision to certify on the marketing advantages, image benefits, and access to new markets that the certified product provides. Overall, certified and non-certified hardwood flooring manufacturers hold widely differing views on certification, and those differing beliefs contribute to the choices each group makes.
Ph. D.

Thesis (Ph. D.)--Indiana University, Dept. of Geography, 2008.
Title from PDF t.p. (viewed Oct. 7, 2009). Source: Dissertation Abstracts International, Volume: 70-02, Section: B, page: 0895. Adviser: Hans Peter Schmid.

Afin de valoriser au mieux le bois de feuillu de qualité secondaire, il est important de comprendre ses propriétés et d'optimiser ses propriétés mécaniques. La variabilité de certaines propriétés structurelles, physiques et mécaniques du bois de hêtres et de chênes issus d’éclaircis a été étudiée. Des billons tirés de ces arbres ont été déroulés en trois épaisseurs (2.1, 3, and 4.2 mm). La qualité du placage a été évaluée en mesurant la proportion du nœud et les fissurations. Les propriétés mécaniques du LVL (lamibois) réalisé à partir de ces placages ont été mesurées par méthode destructive et non destructive. Chez les deux espèces, le bois juvénile est concentré dans une petite zone près de la moelle, de sorte qu'il y aura peu ou pas de bois juvénile déroulé. Les propriétés mécaniques et physiques du bois des deux espèces sont fortement influencées par sa densité. Le placage de 3 mm d'épaisseur a fourni les propriétés mécaniques optimales pour le LVL pour les deux espèces. Ces propriétés mécaniques sont comparables à celles de LVL réalisés à partir d'autres essences de feuillus. Le placage interne a fourni du LVL avec une densité plus élevée, mais des propriétés mécaniques plus faibles en raison de sa proportion de nœuds plus élevée
To improve the value of secondary quality hardwood, it is important to understand its wood properties and optimize its mechanical properties. The variability of some structural, physical and mechanical properties of wood from beech and oak trees issued from thinning was studied. Logs from these trees were rotary peeled in three different veneer thicknesses (2.1, 3, and 4.2 mm). Veneer quality was assessed by measuring the veneer knot proportion and checking properties. The mechanical properties of LVL (laminated veneer lumber) made from these veneers were measured using the static and dynamic method. Juvenile wood in both species is concentrated in a very small area near the pith thus there will be no or low part juvenile wood peeled. The wood mechanical and physical properties of both species were strongly influenced by the wood density. The 3 mm thick veneer provided the optimal mechanical properties for LVL for both species. Such mechanical properties are comparable to LVL made with other hardwood species. The internal veneer provided LVL with higher density, but lower mechanical properties as a result of its higher proportion of knots

In this study, over two hundred furniture manufacturers throughout China were surveyed regarding their raw wood material use in 1996 and their estimated use in 1999. Personal interviews were conducted after a mail survey to get interviewees' perceptions of the Chinese furniture market and raw wood material use. Forty-one overall responses were obtained which included 26 from personal interviews. The results from this study indicate general trends in the industry, and provide some important insights into China's furniture industry.

In 1996, total wood materials used by responding firms were approximately 140,000 cubic meters. On average, hardwood dimension accounted for 25% of the total volume of the wood materials used by wood furniture makers. This was followed by particleboard (24%), hardwood lumber (22%), and medium density fiberboard (MDF) (17%). Domestic species grown in temperate regions were found to be the dominant types used in all responding firms. Chinese oak, ash, and birch were the major species used in 1996. U. S. red oak was the most popular temperate hardwood species imported. Interviewees reported that they prefer temperate over tropical hardwood species because they are predominantly light color. Sampled furniture manufacturers purchased hardwood lumber/dimension either from domestic sawmills or from wholesalers. On average, imported wood materials accounted for less than 7% of the total by volume. Most companies thought that price and quality of materials were most important factors affecting their importing decision. Delivery terms and species availability were important to a lesser degree. Approximately one-half the responding firms reported that their wood material demand would increase 5 to 10% annually through 1999. The other half estimated that their wood material needs would remain at or near the 1996 level. In the near future, high quality hardwood lumber, dimension, and wood veneer will need to be imported to supply upper-end solid furniture manufacturing. However, panel products, such as MDF and particleboard will retain their dominant positions in furniture making to meet the needs of consumers with low to middle incomes.
Master of Science

Innovation research in the wood products industry has historically focused on factors that the firm can influence or control, as opposed to factors external to the firm. The purpose of this research is to understand how the external factors of the firm (i.e., social, technological, economic, ecological, and political or STEEP factors) impact Schumpeterâ s five-factors of innovation (i.e., sources of supply, methods of production, markets, products and services, and business models) in decorative hardwood veneer producing firms. Case studies of hardwood veneer firms in Austria and the United States were conducted to understand these impacts from individual firmsâ perspectives. Innovation strategies of the companies were identified based on their use of innovation resources, leverage of those resources and capabilities to serve customers and markets, and deliberateness or emergence. Interviews of experts in each of the environmental areas from both geographic regions also were conducted to qualify and validate the impacts. An online survey was conducted with hardwood veneer companies in Austria, Germany and the United States to quantify the impacts in these regions, and results were analyzed via cluster analysis to better understand the environmental impacts to innovation and the strategies firms were employing to innovate. The results of the study identified American firms as being most impacted by economic environmental factors and Austrian firms most impacted by social factors. Austrian/German and US firms both made more deliberate than emergent attempts to innovate. US firms most attempted to innovate their business models, while Austrian and German firms most attempted source of supply and product and service innovations. The major implications of this research are the awareness firms in the hardwood veneer industry can gain from understanding the innovation strategies their firms employ, how the environment they function within impacts their innovation, and what they can do about it. By helping this niche industry create sustainable competitive advantages, the industry can overcome the adversities of the mature industry lifecycle phase, including competitive threats from substitute products and increased competition from foreign log buyers, and shift back into a growth phase of the lifecycle.
Ph. D.

Thesis (Ph. D.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains viii, 98 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on April 3, 2008) Includes bibliographical references.

Land disposal of municipal wastewater is considered ecologically acceptable and cost effective. The success of land treatment systems, however, requires proper functioning of all ecosystem components. The impact of municipal wastewater irrigation on the structure and function of an Appalachian hardwood forest in Virginia was investigated. Four irrigation rates (17.5, 35, 70, and 140 em yr⁻¹ ) were applied in this hardwood forest, and their effects on forest nutrient cycling were monitored for two years. Tree growth, seedling reproduction, tree mortality, species diversity, and N sequestering by vegetation were not changed significantly. Herbaceous ground cover increased due to irrigation, except for the 140 cm yr⁻¹ treatment where the heavy spray caused physical damage to the cover. Depending on the rate applied, the mature hardwood forest system sequestered only -3.4 to 8.2 kg N ha yr⁻¹ in the above ground biomass. Therefore, the fate of added N to the system became a function of N transformation processes in the soil. Nitrogen mineralization and nitrification increased as irrigation increased. Denitrification rates were not affected by irrigation; the process of denitrification did not constitute a significant N output from the forest system. The additional soil nitrate (N0₃) was left to leach because of the low assimilation by the plant/soil system and the low denitrification rate. Nitrogen storage decreased in the forest floor due to the increase in litter decomposition, and increased in the surface soil due to the increase in microbial N assimilation. Total soil N increased on the low irrigation sites and decreased on the high irrigation sites, indicating that high rates of irrigation stimulated N loss from the soil by enhancing soil N transformations. The health of the forest ecosystem was not adversely affected during this period, but the forest did not serve as a net sink for N. There was little opportunity for N sequestering in this mature hardwood forest. Without harvesting and regeneration, the system is likely to lose system N when wastewater is applied. When wastewater is applied to lands, N sequestering and denitrification should be maximized in order to minimize the pollution potential of N0₃ leaching to groundwater systems.
Ph. D.

A study was initiated to adapt the REGEN regeneration prediction model to the Appalachians of Virginia and West Virginia. REGEN generates predictions via expert created REGEN knowledge bases (RKBs) that contain competitive rankings and stochastic parameters for selected species and size classes of advance reproduction. We developed RKBs for four site productivity classes (xeric, subxeric, submesic, mesic), and tested two (subxeric and submesic) using field collected inventory data in this study. To test the model we collected data from 48 paired sites which contained a mature stand and an adjacent regenerating stand (clearcut) of similar site productivity harvested within the past 20 years. Across all 48 sites, model predictions were within 5% of measured values on average, and explained 32% (R2 = 0.32) of the variation in species composition in regenerating stands. The species compositions of 41 of the paired stands on the Appalachian Plateau in West Virginia were further analyzed to compare species composition. Species composition was compared between the mature and regenerating stands in the subxeric and submesic site classes. A comparison of the upper canopy (dominant and codominant) species composition in regenerating stands to that of all stems â ¥ 1.5 in dbh in the mature stands was conducted as well. Our results suggest that the future species composition of stands regenerating following clearcut harvests will likely differ from previous rotations with mesophytic, shade intolerant species being more numerous. Oaks will likely assume a smaller role as the clearcuts mature, particularly on the submesic sites.
Master of Science

The U.S. hardwood industry has traditionally depended on the domestic demand to sustain levels of production above 14 billion board feet per year. Because of the collapse of the U.S. housing market in 2009 and the economic recession that followed, the industry moved its sight to the international markets, as an opportunity to replace some lost demand, and pursue long term growth. Previous research on international marketing of hardwood products indicates that, there is a growing concern among U.S. companies to understand the main competitiveness factors in key markets such as Asia and Europe. Finding opportunities to add value to U.S. hardwood exports has been the goal of this research project. A case study and survey research were carried out among importers and exporters, whereby it was found that aspects related to price, quality and service, are critical in achieving competitive advantage. This motivated a study in demand and pricing management, which found that these tasks may be subject to innovation through optimization approaches.
Ph. D.

Increasing global competition, high stumpage and energy prices, and the slowing housing market have challenged the U.S. hardwood lumber industry during the past several years. Many wood product manufactures are trying to remain in business by implementing continuous improvement programs like lean manufacturing. However, the lumber drying process where lumber is kiln-dried in large batches, can significantly increase manufacturing and inventory lead-time; and is a process that tends to limit how lean the remaining process can become. Vacuum drying has the potential to reduce drying times, reduce batch sizes and achieve product quality comparable or superior to conventional drying. The overall goal of this research was to evaluate how vacuum-drying technology could support further lean implementation in manufacturing of hardwood products. Specifically, to estimate conventional and vacuum drying times, quality, and costs for drying 4/4 red oak lumber; to determine by the use of feasibility analysis (cash flow, net present value, and internal rate of return) differences between conventional and vacuum drying for 4/4 red oak lumber; and to determine if the high capital cost of vacuum drying equipment can be justified with the reduction of WIP and cycle time, while meeting desired throughput. The study includes a cost analysis of vacuum and conventional drying, and a determination of the potential financial gains associated with the reduced drying times via vacuum drying. It was determined that vacuum drying quality was equal or better than conventional drying with less checking, end splits, drying stress and shrinkage. Compared to conventional drying, vacuum drying times with air drying and without air drying were 67% less and 70% less, respectively. Conventional and vacuum with no air drying scenarios were determined to be financially feasible when compared using Net Present Value and Internal Rate of Return analysis. However, vacuum drying with no air drying had better NPV and IRR values than conventional drying. The scenario of vacuum with air drying was not feasible. Two case studies, each employing the three drying scenarios (conventional drying, vacuum with air drying, and vacuum without air drying), were used to determine the impact of cycle times and work in process. It was determined that the cycle times for vacuum drying were 87% and 95% less than conventional drying for the first case study and 51% and 90% less than conventional drying for the second. WIP was 48% and 84% less in the first case study and 43% and 92% less than conventional drying for the second. Cycle time was reduced by 87% and 51% for Plant C and D, respectively. Finally it was determined that the reduction of WIP represented a cost saving of 73% and 76% for the two case studies. The reduction in costs, faster drying rates, and equal quality, and reduced cycle times make vacuum drying a potential technology available for improvement of the competitiveness for flooring manufacturers.
Master of Science

Three related aspects of competition in the U.S. hardwood lumber industry were investigated. First, product and supplier attributes that are determinant in hardwood lumber purchase decisions were investigated within four segments of the market for hardwood lumber: Millwork producers, hardwood dimension and flooring producers, wood household furniture producers, and wood kitchen cabinet producers. Attributes with the highest determinant scores were: grading accuracy, supplier’s reputation, freedom from surface checks, competitive pricing, and within-load thickness consistency. The least determinant attribute was the presence of the suppliers logo or trademark. The importance of various attributes was generally consistent across the market segments and producers were relatively well attuned to the needs of lumber users. Lumber users were least satisfied with lumber quality. Lumber producers perceived users to be least satisfied with the availability of certain species. Business-level intended competitive strategy in the industry was investigated through quantitative identification of strategic groups in a sample consisting of the 100 largest U.S. hardwood lumber producers. Factor and cluster analyses were used to define strategic groups along the dimensions of cost leadership, focus, and differentiation. Five strategic groups were identified and examined as to strategic orientation and intra-group homogeneity. The differentiation dimension accounted for the greatest portion of strategic variation. Empirical evidence of the use of hybrid Overall Cost Leadership/Differentiation strategies was found—suggesting that strategic typologies that do not account for this strategy may not be applicable to a mature industry. Predicted strategic change in the industry concentrated on increasing differentiation orientation. Qualitative data concerning competition in the industry was obtained via in-person interviews with executives at twenty of the largest companies in the sample. ln general, the largest and smallest companies in the industry were found to be the most production oriented. Companies self-typed their competitive strategies using Porter‘s (1980) strategic typology. Overall Cost Leadership strategies were the most common followed by Differentiation and Focus strategies. The majority of companies interviewed competed for customers based on quality, customer service, and price—in that order of importance. Proprietary grading was an important competitive tool for larger companies.
Ph. D.

Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains viii, 52 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 47-52).