Treesearch

The repair and remodeling of residential units in both the United States and Canada is an important market for wood products. Many and varied repair and remodeling activities and projects are undertaken annually. Some require substantial amounts of wood products, some none at all. In 2006, about 28 percent of all solid wood products consumed in the United States and 31 percent of all solid wood products consumed in Canada are used for residential repair and remodeling (Adair 2008, FAO 2008, McKeever 2009). This market has become much more important in recent years as housing stocks have...

The construction of new single family, multifamily, and manufactured housing is an important market for wood products in both the United States and Canada. Annual wood products consumption is dependent on many factors, including the number of new units started, the size of units started, architectural characteristics, and consumer preferences. In 2006, about 39 percent of all solid wood products consumed in the United States and 28 percent of all solid wood products consumed in Canada were used for new residential construction (Adair 2008, FAO 2008, McKeever 2009). New residential construct...

Forestry operations require ever more use of expensive capital equipment. Mechanization is frequently necessary to perform cost-effective and safe operations. Increased capital should mean more sophisticated capital costing methodologies. However the machine rate method, which is the costing methodology most frequently used, dates back to 1942. CHARGEOUT!, a recently introduced discounted cash flow methodology is compared with seven machine rate methods using data representing a skidder. I found that use of machine rate methods can lead to either over or under-estimates of machine owning...

It has been argued that repetitive member allowable property adjustments should be larger for high-variability materials than for low-variability materials. We report analytic calculations and simulations that suggest that the order of such adjustments should be reversed, that is, given the manner in which allowable properties are currently calculated, as the coefficient of variation of the strength distribution of individual elements increases, the upward repetitive member adjustments (if any) of assemblies constructed from these elements should decrease.

Pulp and paper production and consumption in both Europe and North America declined in 2008 and 2009 as the global economic crisis took hold. In early 2009, leading trade associations were reporting year-over-year declines of 17% in total paper and paperboard production in both Europe and the United States, considerably more than the 2008 drop. Capacity-utilization rates deteriorated in Europe and North America, leading to a wave of capacity withdrawals in the form of mill downtime and mill shutdowns. By mid-2009, pulp and paper commodity prices were beginning to stabilize or increase...

The objectives of this study are the following: (1) Use solution-state NMR to assign contours in HSQC spectra of the reaction products between pMDI model compounds and: (a) lignin model compounds, (b) milled-wood lignin, (c) ball-milled wood, (d) microtomed loblolly pine; (2) Determine where and to what degree urethane formation occurs with loblolly pine cell wall polymers at 0% and 5% moisture content (MC).

Solution-state NMR spectroscopy is a powerful tool for unambiguously determining the existence or absence of covalent chemical bonds between wood components and adhesives. Finely ground wood cell wall material dissolves in a solvent system containing DMSO-d6 and NMI-d6, keeping wood component polymers intact and in a near-native state. 2D NMR experiments, using 13C-1H one-bond HSQC on non-derivatized cell wall material from loblolly pine reveal details about the major cell wall polymers. This technique can determine covalent bond formation between cell wall polymers and wood adhesives....

Because load-bearing bonded wood assemblies must support the structure during a fire, the limited softening and depolymerization of biobased polymers at elevated temperatures should be an advantage of biobased adhesives compared to fossil fuel-based adhesives. Because load-bearing bonded wood assemblies must support the structure during a fire, the limited softening and depolymerization of biobased polymers at elevated temperatures should be an advantage of biobased adhesives compared to fossil fuel-based adhesives. This study aimed at: 1) advancing biobased adhesive technology using...

To take advantage of nanoscale features in plant cell walls and create our own nanostructures based on plant biomass, we must make reliable measurements at the nanoscale. Although nanoscale measurement methods have expanded in recent years, not all these techniques are useful for soft, hydrophilic, nonconducting biomass specimens. Here we discuss those methods with the potential to be particularly useful in studying nanoscale properties of plant biomass. In contrast to most engineering materials, plant biomass structure changes with water availability. Water swells biomass, creating pores...

We have developed a novel type of nanoindentation creep experiment, called broadband nanoindentation creep (BNC), and used it to characterize the thermal activation of shear transformation zones (STZs) in three BMGs in the Zr-Cu-Al system. Using BNC, material hardness can be determined across a wide range of strain rates (10–4 to 10 s–1) in a single experiment at room temperature. This data can be used to characterize the kinetics of deformation, including the free energy function (ΔG) for thermally-activated deformation. We have found that the activation energy agrees with the theory of...