1. The xylem pressure inducing 50% loss of hydraulic conductivity due to embolism
widely used for comparisons of xylem vulnerability among species and across aridity
However, despite its utility as an index of resistance to catastrophic xylem failure
drought, P5o may have no special physiological relevance in the context of...
Innovativeness can help companies differentiate themselves, with the ultimate goal of securing survival and improving performance. Modern theories in organizational behavior look at innovation as something that starts with individual creativity but that is also affected by the work environment. Using one broad industry sector, the US forest products industry,...
Natural dyes have been used to color textiles for centuries, but with the shift to mass production, the use of synthetic dyes has increased due to their lower cost and easy manufacturing volume. However, synthetic dyes (such as disperse blue dyes 106 and 124) have been reported to cause skin...
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...
In investigating wood treatment as a possible processing option for Alaska forest products manufacturers, the double-diffusion method using sodium fluoride followed by a copper sulfate appeared to be the most advantageous approach. Yet, little information was available as to the chemical retention after treating and its resistance to leaching. Green...
The specification, inspection, and remedial treatment of utility poles are addressed. Included are discussions of enhancing specifications for improved performance, techniques for detecting decay and other defects, and chemical treatments available for arresting decay of poles in service.
Light-frame construction practices and materials have changed greatly
over the past 100 years. Contemporary research has focused on modern construction; thus, we know a great deal about the behavior of modern lightframe buildings under lateral forces. However, there are many light-frame buildings that were built prior to the introduction of...
Cross-sectional disks were cut at two stem heights (1.5 m and 3.0 m) from 9-year-old trees of three Populus clones grown in an intensively-cultured plantation in western Washington. At age 1.5 years, when the trees averaged 3.4 m tall, half of the trees were pruned by removing all branches below...
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...
• A technique for measuring in vitro respiration was investigated to understand why rates were higher than those reported in vivo and to elucidate trends within mature Pseudotsuga menziesii (Douglas‐fir) trees.
• Extracted increment cores were divided into 3–4 radial depths and a gas chromatograph was used to compare respiration...
In deciduous species, water exits stems mainly through leaf traces
attached to the outer growth ring and yet we know that water ascends
throughout the entire cross-section of the sapwood. There is an increasing
amount of information on sap flow and sapwood hydraulic properties from
separate studies, but little information...
The air permeability of western hemlock from coastal forests in western Oregon was assessed. Permeability varied widely among trees, as well as by position within individual trees. Permeability tended to decrease with distance inward from the bark, a trend implying that this species produces a heartwood zone. These variations may...
Each year the United States: Forest Service (USFS) spends billions of dollars fighting forest fires. One strategy used by the USFS to prevent catastrophic fires is through forest restoration programs, in which potential forest fuel is removed through mechanized thinning. This program is expensive and generates high volumes of small-diameter...
The United States spends about $2 billion each year fighting wildfires. While it is a costly operation, mechanized thinning of dense federal forests is one preventative strategy that generates high volumes of small logs. These small logs are often used for wood chips, pulp, or biomass because of the high...
A sawmill is similar to other manufacturing enterprises when it comes to making decisions, scheduling production and meeting customer demands. In order to help sawmills achieve their goals, and because there is such a high degree of variability in the raw material used in this industry, computer simulation has proven...
In recent years, multiple historic and contemporary timber buildings have been instrumented with sensors to monitor the performance of wood products and novel engineering systems. While literature states the potential of structural health monitoring (SHM) data to inform decision-making process of key stakeholders in the architects, engineers, contractors and manufacturers...
Many nondestructive techniques for structural health monitoring are subjective and based on visual observations of degradation. In addition, dynamic properties of structures are already used to obtain quantitative structural health data. However, most current data collection is limited to localized damage on the structure, rather than global response. Recent research...
Wood-based composites (WBCs) are an important sector of the US economy. For a WBC product to succeed, understanding its long-term durability, including seasonal variations in temperature and humidity, is critical. Durability is especially important WBCs because they are predominantly made from wood, which is a biological, hygroscopic material that is...
Of 14 transgenic poplar genotypes (Populus tremula × Populus alba) with antisense 4-coumarate:coenzyme A ligase that were grown in the field for 2 years, five that had substantial lignin reductions also had greatly reduced xylem-specific conductivity compared with that of control trees and those transgenic events with small reductions in...
Since 2004 there have been multiple devastating tsunamis around the globe triggered by large magnitude earthquakes; with the most recent being the Tohoku, Japan tsunami in March 2011. These tsunamis have caused significant loss of life and damage to the coastal communities impacted by these powerful waves. The resulting devastation...
The forces exerted on light-frame wood buildings as a result of surge and waves are not fully understood. With a better understanding of these types of forces, it may eventually be possible to build coastal structures to better withstand the loads. In this paper, a recent two part experimental study...
We determined the axial and radial xylem tension gradients in trunks of young Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Axial specific conductivity (ks-a) and sap flux density (Js) were measured at four consecutive depths within the sapwood at a stem height of 1 m. By definition, at a given position...
We studied xylem anatomy and hydraulic architecture in 14 transgenic insertion events and a control line of hybrid poplar (Populus spp.) that varied in lignin content. Transgenic events had different levels of down‐regulation of two genes encoding 4‐coumarate:coenzyme A ligase (4CL). Two‐year‐old trees were characterized after growing either as free‐standing...
Commercial methodologies for producing fungal pigments are of worldwide interest due to the desire to move away from synthetic dyes. Chlorociboria species and Scytalidium species have been reported to produce sufficient yields of pigments for commercial production and have attracted special attention because of their use in spalted wood applications....
While wood plastic composites have gained an increasingly large share of the market for decks and other outdoor structures, there are many questions about the long-term potential for biodeterioration of these materials. While the plastic does appear to retard moisture uptake, thereby slowing the rate of degradation, a number of...
This thesis consists of three manuscripts related to the methodology of evaluating charring behavior in cross laminated lumber panel specimens subjected to fire performance tests on cross-laminated lumber panel specimens. The topic of the first manuscript is the measurement of char rates of unprotected CLT layups fabricated with ponderosa pine...
This study investigated the effect of exposure to elevated temperature on the yield strength of single-shear nail connections when subjected to lateral loading. Solid sawn lumber and laminated veneer lumber were used as framing members and two different thicknesses of both oriented strand board and plywood were used as the...
The construction industry has relied heavily on wood and wood-based composites, such as oriented strand board (OSB) and plywood for timber frame construction. Therefore, it is highly imperative to categorize the response of wood-based composites when exposed to elevated temperatures for a sustained period of time. The essence of fire-resistant...
Wood and wood-based composites are being used extensively in single-family residential dwellings. Therefore, it is important to categorize their response when exposed to elevated temperatures for a sustained period of time. In fire-resistant design for wood structures, the main goal is to ensure that enough structural integrity is maintained, during...