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The system of model building codes and voluntary product standards used in the United States for structural lumber and engineered wood products can appear complicated and confusing to those introduced to it for the first time. This paper is a discussion of the various types of structural wood products commonly used in U.S. residential and commercial construction and the system of building codes and product and performance standards that help regulate the quality and use of these products.

In laboratory experiments, Douglas-fir wood blocks that were treated with copper- based wood preservatives were challenged with two wood decay fungi known to be tolerant of copper. Factors influencing the amount of decay, as determined by loss of weight in the test blocks, were preservative, then fungus. Within those combinations, the relative importance of preservative retention, block thickness, or leaching depended upon the specific pairings of preservative and fungus. Low retention levels of some preservatives stimulated decay by Wolfiporia cocos but not Postia placenta. We conclude...

Kenaf-based thermoplastic composites were developed and evaluated in this study. The kenaf stems were collected from farms in central Illinois. The kenaf fibers were blended with commercial virgin plastic or polypropylene and with recycled plastics or low-cost polyethylene in form of post-consumer film wastes and shrink wraps. Investigations on the fiber properties and chemical compositions of kenaf stems showed that they can be viably utilized as substitute for wood flour fillers. Manufacturing tests conducted at the U.S. Forest Products Laboratory showed that kenaf stems can be used as...

Xylaria species are common endophytes in tropical plants. It is not known, however, whether transmission of Xylaria occurs horizontally or vertically, whether individual Xylaria strains have wide host ranges or are host-specific, or how they are dispersed. We compared frequency of Xylaria endophytes in leaves and seeds of two tree species in Puerto Rico, Casuarina equisetifolia (Australian pine) and Manilkara bidentata (ausubo). These trees were chosen because they differ markedly in morphology, habitat, distribution, and origin. In C. equisetifolia Xylaria was significantly more frequent...

Most of the approximately 25 to 30 million tons of industrial wood waste generated in the United States per year is burned for energy and/or landfilled. In this study, kraft pulp from industrial wood waste was evaluated and compared with softwood (loblolly pine, Douglas-fir) and hardwood (aspen) pulp. Pulp bleachability was also evaluated. Compared to loblolly pine pulp, industrial wood waste pulp needed less cooking time to achieve the same kappa number and achieved a higher pulp yield for a similar kappa number. Industrial wood waste pulp was more effectively bleached than loblolly pine...

Ten single-spore isolates each of Armillaria sinapina, A. cepistipes, and North American biological species (NABS)X and XI were paired in all combinations. A second set of ten single-spore isolates of each species was likewise paired. Each pairing was duplicated for a total of 3280 pairs. Using the standard morphological criteria (e.g., fluffy, crustose) to assess the pairings, A. sinapina exhibited the following compatibility levels: 68% with itself, 5.5% with A. cepistipes, 3.5% with NABS X, and 5% with NABS XI, respectively. Armillaria cepistipes was rated 53%, 6.5%, and 57% compatible...

A useful genetic system has been developed for the transformation of Pichia stipitis. This includes two selectable markers (URA3 and LEU2), integrating and autonomous replication vectors, a pop-out cassette that enables multiple targeted disruptions, and a genomic X-library for rapid cloning. Using this system we have cloned two genes for alcohol dehydrogenase (PsADH1 and PsADH2). two genes for pyruvate decarboxylase (PsPDC1 and PsPDC2). and cytochrome c (PsCYC1). Disruption of PsADH1, but not PsADH2, resulted in increased xylitol production. Disruption of PsCYC1 resulted in lower growth...

Exterior house paint has undergone some changes in recent years. Designers now have their own brands. And on a technical front, water-based paint now outstrips oil-based paint in quality and durability. You have six decisions to make1 stain versus paint...oil versus latex... type of latex...type of finish...quality level...and brand-name versus generic.

Researchers at the USDA Forest Products Laboratory have developed a new three-dimensional structural panel, called FPL Spaceboard. This panel is formed using a U.S. patented three-dimensional mold capable of using a variety of fibrous materials with either the wet- or dry-forming process. Structurally, the panel departs from the traditional two-dimensional panel by integrally forming vertical ribs and face in one structure. In the literature, significant work has been conducted to model drying of two-dimensional panels, but no known work has been done on such a three-dimensional integral...

This research study proposed to include the glue material in a finite element model that represents the actual geometry and material properties of a corrugated fiberboard. The model is a detailed representation of the different components of the structure (adhesive, linerboard, medium) to perform buckling analysis of corrugated structures under compressive loads. The objective of this analysis was to quantify the influence of the adhesive on the structural performance of corrugated fiberboard. Adhesive parameters are identified in terms of adhesive stiffness and material properties. The...