Treesearch

Preliminary studies have shown that electrochemical methods, especially Electrochemical Impedance Spectroscopy (EIS), appear to have great promise for measuring the corrosion rate of metals in wood. One of the major reasons for using these techniques is the ability to maintain moisture content and temperature at conditions encountered in service while measuring the instantaneous corrosion rate. For these reasons, EIS and other electrochemical methods have been investigated at the USDA Forest Products Laboratory in Madison, Wisconsin. This paper discusses progress made and problems encounter...

Following natural disasters (such as hurricanes, tornados, or tsunamis), when civilians become displaced, or when military troops are deployed overseas, temporary housing is often a critical need. The USDA Forest Products Laboratory recently developed a lightweight, transportable, reusable, and recyclable biocomposite building material—threedimensional engineered fiberboard (3DEF)—that can be used to uniquely meet this need. Once commercialized, this material can be made in large sheets—as large as the manufacturer’s platen—designed to serve as single-piece prefabricated wall, floor, and...

The isotopic composition of ancient wood has the potential to provide information about past environments. We analyzed the ä13C, ä18O, and ä2H of cellulose of conifer trees from several cross-sections at each of 9 sites around the Great Lakes region ranging from ~4000 to 14,000 cal BP. Isotopic values of Picea, Pinus, and Thuja species seem inter-changeable for ä18O and ä2H comparisons, but Thuja appears distinctly different from the other 2 in its ä13C composition. Iso-topic results suggest that the 2 sites of near-Younger Dryas age experienced the coldest conditions, although the Gribben...

Janka hardness determined on 1.5- by 3.5-in. specimens (2×4s) was found to be equivalent to that determined using the 2- by 2-in. specimen specified in ASTM D 143. Data are presented on the relationship between Janka hardness and the strength of clear wood. Analysis of historical data determined using standard specimens indicated no difference between side hardness values determined on the radial face as opposed to the tangential. Analysis of historical data also indicated that the relationship between hardness modulus (HM) and Janka hardness (H) may be different for hardwood species than...

The regulation of building materials and products for flammability is critical to ensure the safety of occupants in buildings and other structures. The involvement of exposed building materials and products in fires resulting in the loss of human life often spurs an increase in regulation and new test methods to address the problem. Flammability tests range from those in which the sample is ground to a powder prior to testing to the full-scale room comer test. Variations in test methods include the specific measurement of flammability parameters being considered, the intensity and character...

The threat of insects in or around your home can be alarming, especially when those insects can cause structural damage. It is important to know if insects you find around the house are in fact termites or some other crawling insect. Subterranean termites are found everywhere in the contiguous United States, making the possibility of termite infestation a widespread structural damage problem. Early detection and treatment of termites can drastically reduce the threat of damage to your home.

This poster presentation reports on recent laboratory work aimed at quantifying the biodegradation process of wood during exposure to natural weathering. Approximately 330 southern pine lumber specimens were placed “above-ground” at an outdoor exposure site near Gulfport, Mississippi for periods up to five years. An additional 90 specimens were stored indoor to serve as controls. Two chemical preservative treatments, CCA and DDAC, were also applied to several sets of lumber specimens. NIR spectroscopy techniques were used to characterize the condition of the weathered wood surface....

The laser induced breakdown spectroscopy (LIBS) technique was evaluated for its capability of quantifying CCA in preservative-treated wood. The results of the study reveal that the LIBS technique can be used to predict the amount of preservative based on chromium peak analysis, but further refinement of the process is necessary before the technique is practiced. The largest variation measured by the LIBS system is the result of heterogeneity in the wood matrix, specifically between transitions corresponding with earlywood and latewood growth.

Wood can be chemically modified to reduce the moisture content of the cell wall and increases decay resistance. As the level of bonded chemical increases, the cell wall equilibrium moisture content decreases and the resistance to attack by white-and brown-rot fungi increases. There is a direct relationship between the decrease in cell wall moisture Content and resistance to fungal attack.

As the world population grows, there is a growing awareness that our environment is getting more polluted. Clean water is becoming a critical issue for many parts of the world for human, animal and agricultural use. Filtration systems to clean our air and water are a growing industry. There are many approaches to removing contaminates from our water supply ranging from reverse osmosis to simple sand filters. Agricultural residues represent a low cost, renewable, available, and sustainable resource that can remove metal ions from water.