Every wood anatomist knows that the wood near the center of a tree (juvenile wood) differs from the wood laid down at some distance from the pith (mature wood), and that the wood produced during the spring (earlywood) differs from the wood produced during the summer (latewood). There is a...
The internal structure of natural fiber composites can be manipulated by controlling the spatial distribution of fiber orientation and internal chemical and thermodynamic conditions during their consolidation. Objects highly tailored to specific service demands may thereby be produced. Techniques to form miniature structural beams from oriented hemp and random wood...
An increment core-based, laboratory method was used to measure tissue-level respiration under controlled temperature (termed respiratory potential) of eleven tree species from three age classes. Respiratory potential was calculated on a basis of core dry-mass, volume, carbon, or nitrogen content and live bole volume. Methods tests suggested that core carbon...
Supercritical fluid (SCF) impregnation is a promising preservative treatment method, however, the development of SCF processes has been slowed by a limited understanding of the process. Developing a better understanding of the effects of various process parameters on treatment results would allow for a more rational development of SCF impregnation....
This study examined the decay resistance of the pine and maple components of wood plastic composites (WPC' s) of varying thicknesses exposed on several culture media to wood decay fungi under laboratory conditions. The ability of malt agar extract (MEA), potato dextrose agar (PDA), amended basal salts, sawdust (maple and...
While microbial colonization of wood is presumed to be characterized by a myriad of interactions between numerous organisms, studying these processes is often difficult owing to the opaque nature of the wood and the inability to readily distinguish among the many species colonizing the material. One method for enhancing the...
Service life prediction models for light-framed wood structures require an extensive quantity of empirical data on deterioration pathologies for the numerous structural components, as well as mechanistic approaches to determine their capacity at various levels of deterioration. The data and models presented in this study satisfy a portion of the...
Heartwood can have properties that are distinct from sapwood,
including resistance to insect and microbial attack. Despite the practical
importance of heartwood formation in trees, a review of the literature revealed
that little was known about the effects of environmental factors on heartwood
quality or how variations in heartwood properties...
The goal of this project was to develop an integrated pest management strategy
for the control of a powder-post beetle (Dinoderus minutus F.). This species causes
serious damage in Philippine bamboo. Developmental threshold and thermal constants
were examined and natural enemies and ftmgi associated with beetles were investigated.
Finally, the...
In wood-plastic composites (WPCs) a compatibilizer is often used to improve
the interfacial adhesion between the hydrophilic wood filler and the hydrophobic
plastic matrix. At present, while the basic concepts of compatibilization are
understood, the optimized chemical structures of an effective compatibilizer, including
the ideal structures of the wood-binding domain...
Wood-plastic composites (WPCs) are one of the fastest-growing sectors of the
wood composites industry. However, the strengths of WPCs are typically low
because of the poor interfacial adhesion between hydrophilic wood and
hydrophobic thermoplastics. A compatibilizer that can form bridges between wood
and plastics is required to give WPCs desirable...
Presently, the production of wood composites relies on the formaldehyde-based wood adhesives such as phenol-formaldehyde (PF) and urea-formaldehyde (UF). However, their dependence on exhaustible fossil fuels and the emission of carcinogenic formaldehyde prompt to develop an environmentally friendly adhesive from renewable natural resources. This work focuses on development and characterization...
Innovativeness, or the propensity of a firm to create and/or adopt new products, process and business systems, has been measured using several methods in previous research. Examples of theses methods include current technology, self-evaluation, research and development funding, the number of new products, and intellectual property. In addition to the...
There has been an increasing realization of the value of innovativeness, the orientation toward innovation, for firms thriving to gain competitive edge. The US forest products industry is no different in this respect and many companies have active initiatives to bring about creativity from their own employees. At the same...
Business is a social institution and society has always designated a role for
business which has been undergoing changes with changing societal values and
paradigms. Thus while business has always had some responsibilities, the modern
connotation of the words corporate social responsibility commonly refers to business
assuming responsibilities in economic,...
The fabrication of nano-scale devices is a challenging, but potentially important, technology that has drawn a great deal of interest among researchers. Such nanoscale constructions utilizing a bottom-up approach for device building have many foreseeable applications in areas as diverse as miniaturized electronics, sensors, and biomedical devices.
One of the...
Non-destructive commercial ultrasonic grading provides laminated veneer lumber (LVL) manufacturers a means for sorting veneer based on average ultrasonic propagation time (UPT) and/or average dynamic modulus of elasticity (MOEd). While this may provide reliable estimations of modulus of elasticity (MOE), little is known about the influence of veneer defects on...
Society uses massive quantities of wood fiber in production of paper, and demand for fiber is projected to increase further as production of biofuels from fermentation of plant cellulosic materials increases. Because these end uses generally require the costly step of removing of lignin, wood with reduced or more easily...
The importance of wood bonding increased in the last decades due to the
increased usage of wood composites whose performance depends to a large extent on
the adhesive penetration and subsequent bonding of the adherends. The presented
research used XMT (x-ray microtomography) to perform a non-destructive, threedimensional
analysis of the...
Rubber without reinforcement has limited applications. The strength of reinforced rubber composites can be ten times stronger than that of unreinforced rubbers. Therefore, rubber composites are widely used in various applications ranging from automobile tires to seals, valves, and gaskets because of their excellent mechanical elastic properties. Silica and carbon...
In wood-based composites, the glue-line (interface) between wood-strands affects the stress transfer from one member to the next. The glue-line properties determine the rate of load transfer between phases and these properties depend on wood species, surface preparation, glue properties, glue penetration into wood cells, and moisture content of the...
Policy makers in the United States (US), following recommendations made by the international scientific community, have drafted national emissions reduction legislation in hopes of minimizing the harmful effects of global climate change. Included in this legislation is a national cap-and-trade system with provisions for carbon offsets. Specific provisions for forest...
Variability in wood properties causes boards within a stack of lumber to
dry at different rates and reach different moisture content levels after drying is
completed. The consequence is that the boards will have properties that differ from
ones that were intended to be achieved by the drying process.
The...
Treating durable, second-growth or plantation-grown material with supplemental chemicals could improve durability while enhancing the uniformity of the products. To test this hypothesis, the effect of two candidate biocide treatments on the durability of teak, redwood, and western redcedar was assessed in a ground proximity field test established in Hawaii....
Moisture intrusion in residential structures can lead to substantial fungal decay and this damage costs billions in repair/replacement costs. The extent of damage and the rate at which it occurs are primarily dependent on the wood moisture content and temperature in the structure. Determining the risk of decay for various...
Engineers, in practice, are often faced with the challenge of evaluating a fire-damaged structure and developing a rehabilitation and retrofit plan. In order to decide on a rehabilitation and retrofit plan, information on thermal degradation of building materials and connections are vital. A critical knowledge gap exists in terms of...
The wood-based building products industry has experienced significant turbulence over the past several decades as a function of multiple forces including among others globalization, product and process innovation, and shifting customer and consumer interest and demands. Collectively, these changes have challenged the historical tenets which have defined industry strategy and...
Rapid discoloration and checking of wooden surfaces when exposed outdoors has caused wood to fall out of favor as an outdoor building material, especially in applications where appearance is important. The surface appearance of wood products exposed outdoors can be improved through the application of film forming coatings or by...
During the past several decades, earthquakes have caused extensive damage to
buildings, including wood-frame, single-family dwellings, in the United States. In
order to mitigate future losses, existing buildings in earthquake prone areas should be
evaluated for their seismic safety. This is also an important issue for buildings in
Oregon due...
Natural fibers are gaining popularity as reinforcement materials for thermoset resins over the last two decades. Natural fibers are inexpensive, abundant, renewable and environmentally friendly. Kenaf fibers are one of the natural fibers that can potentially be used for reinforcing unsaturated polyester (UPE). As a polymer matrix, UPE enjoys a...
There are about 80 million single-family dwellings (SFD) in the United States, predominantly of wood-frame construction. Of these, 68% are owner occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all SFD in...
There is no doubt that adhesive penetration plays an important role in wood bondline joint performance and durability; yet, to date there is no direct experimental evidence linking penetration depth with bond performance. This is, in part, because adhesive penetration is commonly assessed with various 2D microscopy techniques that are...
The mechanical performance of composite materials is determined by the mechanical properties of their individual components and the effective load transfer between these components. Binders are commonly used to bond composite components together and to provide effective load transfer between them. In wood-based composites the binder-component load transfer occurs at...
In the forest products business and management literature, one common categorization of different types of innovation is product innovation, process innovation and business systems innovation. Forest products companies have long placed high emphasis on process innovations, which are related to yield maximization, manufacturing efficiency and operating costs reduction. This is...
A Life Cycle Assessment (LCA) of the production of poplar biomass grown under four management conditions in the Pacific Northwest (PNW) of the U.S.A. was conducted. While the extraction of fossil fuels and the subsequent generation of energy have environmental impacts, the alternative of extracting poplar biomass also has impacts...
Many wood composites are known to poorly resist the effects of moisture and temperature extremes over time. Degradation of adhesive bonds, irreversible thickness swell and dimensional instability result in a decrease of properties and a possible failure of the material. Accelerated weathering has become an essential tool for assessment of...
As the forest industry moves toward the use of younger trees and production of an increasing number of composite products improving durability has gained importance. Coatings are one of the most widely used methods for improving wood durability because they improve resistance to water penetration, and subsequent shrinking and swelling,...
Today nano scale materials are being used for wide range of applications. One promising topic in nano scale materials is using them for reinforcement of different polymeric materials to reach desirable stiffness properties. The stiffness of these materials is mostly found experimentally because the nanocomposite community lacks a decent analytical...
Most of existing commercial unsaturated polyester (UPE) resins are typically composed of a UPE and a high amount of highly volatile, flammable, and toxic styrene. The emission of hazardous styrene in the handling of the UPE resins and the preparation and use of fiber-reinforced UPE composites poses severe hazards to...
Spalting fungi show strong potential as natural colorants on a variety of materials, specifically textiles and wood. Four species of spalting fungi are currently utilized in this manner: Scytalidium cuboideum, which produces a red pigment called draconin red, Scytalidium ganodermophthorum, that produces an unknown yellow pigment, and Chlorociboria aeruginosa and...
One of the recent additions to the panoply of engineered wood products is cross-laminated timber (CLT). CLT is a prefabricated, large-scale, solid wood panel that consists of multiple layers of lumbers stacked together, with each layer arranged perpendicular to the next layer, glued with structural grade adhesives, and pressed. The...
This work is a culmination of a series of published works related to the use of the Material Point Method (MPM) in modeling wood adhesive bonds. The use of wood as construction material has the potential to play a small role in the solution to the current CO2 and climate...
During the 1400s – 1600s, spalted wood was an expensive commodity used in marquetry style artworks across primarily Germany and Italy. It fell out of favor during the Industrial Revolution, but is currently experiencing resurgence in popularity with US woodturners. How spalted wood is used, and what types of spalted...
Fungi are the primary biological agents of wood deterioration and cause major economic losses of wood products globally. Wood in outdoor applications tends to remain wet for extended time periods, making it susceptible to fungal attack. Understanding the factors involved in fungal colonization of wood is important for developing improved...
Wood-staining fungal pigments have potential uses as colorants for wood and textiles. Traditionally, organic solvents have been used as carriers for these pigments. However, other environmentally-friendly and more readily available carriers must be found. Natural oils have the potential to carry these pigments but have demonstrated color loss over relatively...
The majority of low-rise residential structures in the U.S. are constructed with wood. Wood-based composites are primary building materials in these structures, used as structural sheathing, joists, and beam components. Wood composites are susceptible to degradation upon exposure to high levels of moisture. Moisture durability is routinely assessed with accelerated...
Natural durability remains one of the most attractive characteristics of wood, and helps wood obtain a premium price. A worldwide shift towards the use of younger trees from intensively managed forests has created greater concerns about wood quality, especially the wood’s resistance to fungi and insects. Wood durability is assessed...
Wood-based composites such as plywood and particleboard are produced with a thermoset adhesive via a hot-press process. At present, UF is the most commonly used thermoset adhesive for production of decorative plywood. The emission of the carcinogenic formaldehyde from UF-bonded panels during the use of panels affects the indoor air...
Timber engineering is currently in the midst of a significant evolution due to the rise of mass timber products, like cross-laminated timber (CLT). Increasing numbers of structural engineers are facing the challenge of designing lateral-force-resisting systems (LFRS) for multistory CLT structures. LFRS solutions such as steel frames, concrete cores, or...
Cross-Laminated Timber (CLT) is one of the latest engineered wood products to show promising structural features for a variety of structural purposes including resisting lateral loads. For CLT to be widely adopted, its modal behavior needs to be fully evaluated through experimental and numerical methods. It is important to the...
Existing strategies and policies have emphasized the need for cross-sector collaboration as a means for the forest sector to be more competitive. Cross-sector collaboration initiatives of forest sector companies with neighboring industries such as energy, chemicals, plastics, textiles, and packaging are gaining increasing attention as a necessary element for a...
Using plant fibers as a potential renewable material to substitute for glass fibers in fiber-reinforced polymer composites has been growing since the late 1990s. Due to high demand, there has been a shift towards ‘green concept’ material in many applications. Numerous secondary plant fibers have been explored as a source...
Generally presented as a preferred social norm based on both ethical considerations and legislative demands, gender equality has been highly encouraged in recent years. For instance, The United Nations Sustainable Development Goals for 2030 call out achieving gender equality and empowerment of women. However, although there are multiple efforts to...
Restoration programs effectively prevent or mitigate wildfires and pest outbreaks in the forest lands. The most common approach is to selectively harvest smaller and dead trees in order to preserve larger and superior trees. Ponderosa pine, Pinus ponderosa, (PP) lumber is one of the common species harvested from restoration programs...
With growing interest in mass timber, especially mass timber panels (MTP), there has been a need to better understand their structural properties. One of the most versatile uses for MTP are as floor systems. Under new code provisions, these floors can be utilized in new and taller building types, but...
Conflicts and disasters displace millions of populations worldwide. There is a need for rapid and affordable housing to cater to the needs of the displaced and unhoused population. Experience from previous post-disaster responses shows that temporary housing should be rapidly deployable, planned for months to years, and should be environmentally...
Mass timber (MT) offers viable eco-conscious solutions within the building industry, with its high strength ratings, dimensional stability, light weight and renewable nature enhancing its status as a low carbon alternative to conventional building materials like steel and concrete. Moisture intrusion, coupled with the inherent organic nature of wood pose...