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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...

Wildfires are getting extreme and more frequent because of increased fuel loads in the forest and extended dry conditions. Prevention of wildfire by fuel treatment methods will generate forest residues in large volumes, which in addition to available logging residues, can be used to produce biofuels and bioproducts. In this study, the techno-economic assessment of three portable systems to produce woodchips briquettes (WCB), torrefiedwoodchips briquettes (TWCB) and biochar from forest residues were evaluated using pilot-scale experimental data. A discounted cash flow rate of return method...

It has been common practice to assume that a two-parameter Weibull probability distribution is suitable for modeling lumber strength properties. In a series of papers published from 2012 to 2018, Verrill et al. demonstrated theoretically and empirically that the modulus of rupture (MOR) distribution of a visual grade of lumber or of lumber that has been “binned” by modulus of elasticity (MOE) is not a twoparameter Weibull. Instead, the tails of the MOR distribution are thinned via “pseudo-truncation.” The theoretical portion of Verrill et al.’s argument was based on the assumption of a...

Bolted/pinned joints in orthotropic composite materials have received considerable attention over the years. Bolt fastening is one of the most commonly used methods to connect wood to wood and/or wood to steel, etc. Stresses at such connections can be the “Achilles’ heel”, causing structural failures. Notwithstanding the challenges in stress analyzing bolted joints, their advantages and widespread use motivate developing ability to optimize their design. Acknowledging the above, a finite element code is combined here with a screening optimization algorithm to optimize a bolt-hole pattern...