Treesearch

Brown rot (BR) decay mechanisms employ carbohydrate-active enzymes (CAZymes) as well as a unique non-enzymatic chelator-mediated Fenton (CMF) chemistry to deconstruct lignocellulosic materials. Unlike white rot fungi, BR fungi lack peroxidases for lignin deconstruction, and also lack some endoglucanase/cellobiohydrolase activities. The role that the CMF mechanism plays in “opening up” the wood cell wall structure in advance of enzymatic action, and any interaction between CMF constituents and the selective CAZyme suite that BRs possess, is still unclear. Expression patterns for CMF redox...

In April, the vast majority of month-over-month and year-over-year categories were negative. The substantial declines are attributed to the impact of the Covid-19 virus. On a month-over-month basis, single-family under construction and new single-family sales were positive. Year-over-year, total multifamily housing under construction and private residential and single-family construction spending indicated improvement.

To evaluate the reliability of lumber structures, good models for the strength and stiffness distributions of visual and machine stress–rated (MSR) grades of lumber are necessary. Verrill and coworkers established theoretically and empirically that the strength properties of visual and MSR grades of lumber are not distributed as 2-parameter Weibulls. Instead, strength properties of grades of lumber must have “pseudo-truncated” distributions. To properly implement the pseudo-truncation theory (to correctly estimate the MOR and MOE distributions of graded subpopulations), one must know the...

This article details techno-economic analyses for producing alternative jet fuel (AJF) at a greenfield integrated biorefinery (IBR) using softwood forest residues. The scenarios and their corresponding economic outcomes differ based on the co-product selections. The selected technology to produce AJF uses a mild bisulfite pretreatment process to prepare the feedstock for enzymatic hydrolysis and fermentation to isobutanol, which is then upgraded to hydrocarbon ‘drop-in’ fuels using an alcohol-to-jet process. The hydrocarbons are a combination of jet fuel and aviation gasoline (AvGas). The...

The above-ground performance of decking treated with two alternative copper-based preservative formulations is being evaluated at a test site near Madison, Wisconsin, USA. Southern pine sapwood lumber specimens (38 mm by 140 mm by 910 mm) were pressure treated with 0,93 %, 1,40 % or 2,34 % (oxide basis) actives concentrations of a boron-copper formulation (BC) composed of 7,2 % copper hydroxide and 92,8 % sodium tetraborate decahydrate. Similar specimens were pressure-treated with 0,66 % or 1,32 % actives concentrations of a copper-zinc formulation (CZDP) composed of 18 % copper (CuO...

Machine lumber grading has been applied in commercial operations in North America since before 1963, and research has shown that machine grading can improve the efficient use of wood. However, industry had been reluctant to apply research findings without clear evidence that the change from visual to machine grading would be a profitable one. Since 2000, when the most recent version (FPL-GTR-7) of this report was published, new equipment, production scenarios, forest resource changes, and other issues have arisen, resulting in the need for another update. This new report provides key...

Summary of presentation given at the RTA annual meeting in 2019. The presentation discussed the use of born rods as a form of passive dual treatment for borate/creosote treated ties/timbers.

The present study investigated the effects of exposure of bamboo–plastic composites to three aggressive fungi species on mass loss values. Polyvinyl chloride was used as the synthetic matrix of the composite. Three mixing combinations were used for bamboo– polymer composites, namely 40/60, 50/50, and 60/40. The injection-molded process was employed to produce the composites. Specimens were prepared according to modified European standard specifications (EN-113) to be exposed to white-, brown-, and softrot fungi each month for 4 months. The results indicated that the soft-rot fungus...

Water vapor sorption is a fundamental physical property of wood and has numerous implications for the behavior of wood as a building material. As a result, water vapor sorption isotherms have been studied for over a century and are the topic of countless publications. Despite their importance and depth of study, there has not yet been a thorough review of these studies that can be used to guide readers to the highest quality sorption data. Sorption data acquired at multiple temperatures are frequently used for thermodynamic analysis or to validate sorption models. This review summarizes...

To keep environmental product declarations current, the underlying life-cycle inventory data and subsequent life-cycle assessment (LCA) data for structural wood products must be updated. This publication developed the cradle-to-gate LCA production of southeast laminated veneer lumber aligned to the new ULE 2019 wood product PCR.