Treesearch

As a result of the dominance of urea formaldehyde (UF)-bonded particleboard, it seemed worthwhile to examine formaldehyde emissions years after production. A California Air Resources Board (CARB) phase II-compliant commercial particleboard produced with a UF resin adhesive was compared to a no-added formaldehyde (NAF)-particleboard produced with Soyad™ adhesive resin for formaldehyde emissions during exposure to elevated humidity and temperature conditions after being in a room at 21 ± 1.9 ◦C, 50 ± 3.3% relative humidity for 3.5 years. A modifed version of EN 717-3 was used to collect...

Fungal decay and fire resistance properties of wood treated with nanochitosan-TPP particles were investigated. Quaternized and nonquaternized nano-chitosan particles crosslinked with a commercial fire-retardant, tripolyphosphate, were prepared from low molecular weight chitosan (with a molecular weight of 50 to 190 kDa). Different treatments were performed on southern yellow pine wood samples via a vacuum impregnation process for both quaternized and non-quaternized nanochitosan-TPP particles with a concentration ratio of 12% to 4.8% (nanochitosan to TPP). Both the leached and unleached...

A counter-balanced mass measurement system was constructed to allow measurement of water loss from a full-scale wood-framed wall assembly. Water was injected onto a localized area of paper towel adjacent to the oriented strand board (OSB) wall sheathing. Moisture pins in the OSB and relative humidity/temperature sensors inside the insulated wall cavity monitored conditions as the wall dried out. The wetted OSB area’s moisture content dropped at a faster rate than the total mass of the wall, indicating moisture redistribution within the wall. A simple model was used to calculate overall...

We previously described the structure and activity of a glycoside hydrolase family 30 subfamily 8 (GH30-8) endoxylanase, CaXyn30A, from Clostridium acetobutylicum which exhibited novel glucuronic acid (GA)-independent activity. Immediately downstream from CaXyn30A is encoded another GH30-8 enzyme, CaXyn30B. While CaXyn30A deviated substantially in the highly conserved β7-α7 and β8-α8 loop regions of the catalytic cleft which are responsible for GA-dependence, CaXyn30B maintains these conserved subfamily 8 amino acid residues thus predicting canonical GA-dependent activity. In this report,...

While there are a handful of universally toxic woods (e.g., yew), for most woods and woodworkers, toxicity is a complex but fundamentally individual matter. Some people will react to minor exposures to a given wood, while others can work that species with no obvious effect. What matters most is how we are exposed to those chemicals, how our bodies can react, and how we can protect against exposure to those chemicals.

In May, construction data was weak, but improvements were noted. Total starts; total, single-family, and multi-family permits; and new single-family sales increased on a month-over-month basis. On a year-over-year basis, most of the data indicated declines, except for total starts, new single-family sales, and total private residential construction spending. The impact of the Covid-19 virus is still evident in this month’s data.

In June, housing starts and new house sales were reassuring, as housing was a bright spot for the U.S. economy, albeit a subdued one. Total, single-, and multi-family starts; total and single-family permits; total and single-family completions; and new and existing house sales were positive on a month-over-month basis. Housing under construction and completions were the only subsectors registering positive data year-over-year. The majority of housing subsector data were negative. The effect of the Covid-19 virus is still evident in June’s data.

With this guide we want to provide an overview of the current best-practice methods used to analyse data derived from different wood identification methods, while presenting their respective strengths and limitations. We give advice on data analysis, from the development of reference data, through to the verification of identity and provenance of unknown samples against the reference database. We end with an expert view on combining methods for wood identification and discuss how timber identification possibilities could expand in the future.

Forests, estimated to contain two thirds of the world’s biodiversity, face existential threats due to illegal logging and land conversion. Efforts to combat illegal logging and to support sustainable value chains are hampered by a critical lack of affordable and scalable technologies for field-level inspection of wood and wood products. To meet this need we present the XyloTron, a complete, self-contained, multi-illumination, field-deployable, open-source platform for field imaging and identification of forest products at the macroscopic scale. The XyloTron platform integrates an imaging...

The use of less-toxic solvents is highly desirable for biopolymer processing and applications to meet sustainability while alleviating environmental burdens. In this study, chitin was propionylated to improve its solubility. The highly propionylated chitin exhibited considerably improved solubility (up to 96%) in a binary ethanol/water solution as compared to almost insolubility in a single solvent (either ethanol or water). Transparent films were prepared with acidified solutions and possessed excellent mechanical properties with a tensile strength up to 40MPa and Young’s modulus of...