Treesearch

To meet newer environmental standards, modified plant proteins have been studied as no-added formaldehyde wood adhesives for interior applications. Many methods have been developed to increase the wet strength of wood products bonded with soy adhesives. These methods involve modifying the soy in separate steps prior to formulating the adhesive or adding a polymerizable co-reactant to the soy. We show that adding periodate, permanganate, or iodate to soy flour improved the strength of soy adhesive bonds in small-scale testing and in plywood shear, especially when tested under wet conditions....

Recently, measured flame spread indices on commercial wood species tested per ASTM E84 were found to be lower than previously published data. One reason for this may be that the hygrothermal conditioning of the red oak calibrant required by the test standards for measuring flame spread was changed between 1973 and 1981. This paper examines how much variability there is in the moisture content of commercially important wood species at 50% relative humidity by collecting water vapor sorption isotherms. Additionally, the effect of moisture content on the flame spread was evaluated after...

This article reports on the development of accelerated laboratory methods to allow estimation of preservative leaching frompressure-treated wood exposed to precipitation. End-matched lumber specimens were pressure-treated with a boron–copper formulation and exposed to natural weathering for 1 yr, laboratory immersion protocols, or a laboratory-simulated rainfall protocol. The rainfall runoff or immersion water was collected at intervals according to the method used and analyzed for concentrations of copper and boron. Of the laboratory methods evaluated, the simulated rainfall approach...

Continuous exterior insulation is becoming more common in North America in above-grade exterior walls in both retrofit applications and new construction. It is used to improve the overall thermal performance of wall assemblies. The drying capability of wall assemblies with exterior insulation and an interior vapor retarder in cold climates is not well characterized. The moisture performance of wood-framed wall assemblies with and without exterior insulation was monitored during a 2-year period in the cold climate of Madison, Wisconsin, USA, under low and high interior humidity conditions...

Metal fasteners are used to hold wood structures together. In outdoor applications, these fasteners are subject to corrosion when the wood is treated with certain preservative treatments. Typically, these treatments contain copper. Prior work has hypothesized that the mechanism of corrosion in treated wood involves reduction of copper ions from the wood treatments. However, copper was rarely detected in the corrosion products of metals embedded in treated wood, which contradicts the hypothesized mechanism. This present work utilizes synchrotron based X-ray fuorescence microscopy (XFM) and...

July housing data rebounded in the majority of categories; yet, the aggregate housing market appears to be in a sluggish mode. Total permits and starts, including single-family permits and starts crept into positive territory. Total starts were negative on a year-over-year basis. Housing under construction also crept into positive territory on a monthly basis. Total and single-family housing completions were negative on a month-over-month basis. New single-family sales declined month-over-month but were robust on a year-over-year basis. Private residential construction spending indicated...

Sorption of water vapor in cellulosic materials has been studied for more than 100 years. However, the last 2 decades have seen a surge in studies of sorption kinetics due to the adoption of automated sorption balances in laboratories world-wide. Sorption kinetic data is commonly fitted with the parallel exponential kinetics (PEK) model, which is the sum of two exponential functions. The PEK model parameters are often interpreted as representing phys-ical quantities or material properties, but their exact definition remains undetermined. Nonetheless, PEK fitting of sorption data has been...

The primary purpose of this publication is to provide an overview of the information in the statistical literature on the different methods developed for fitting a Weibull distribution to an uncensored set of data and on any comparisons between methods that have been studied in the statistics literature. This should help the person using a Weibull distribution to represent a data set realize some advantages and disadvantages of some basic methods. It should also help both in evaluating other studies using different methods of Weibull parameter estimation and in discussions on American...

Bats are amazing animals. They are among the best flyers of the natural world and are able to maneuver in the dark to intersect small flying insects. Bats consume large quantities of insects, and this helps hold down the populations of pests that could otherwise destroy agricultural crops and forests. Bats also pollinate many species of plants that provide us with food and medicine. Most people in the United States view bats as pests, and this view has undoubtedly contributed to precipitous declines for some species. However, in much of Europe, bats are protected and measures are taken to...

Woody biomass feedstock that is both high quality and low cost has become increasingly important for the bioenergy and bioproducts industries. Logging generates forest residues – low-quality feedstock – and additional operations that also incur additional costs, such as biomass sorting and treetops processing (BSTP), micro-chipping, and screening, which are required to improve the feedstock’s quality. Considering recent developments in technologies and BSTP to generate high-quality feedstocks, economic models were developed in this study to estimate various forest-residue logistics...