Treesearch

Water vapor sorption is the most fundamental aspect of wood-moisture relations. It is directly or indirectly related to the physical properties of wood and the onset of wood-damage mechanisms. While sorption properties of cellulosic materials have been utilized since antiquity, the time-dependent transition from one moisture content to another (i.e., sorption kinetics) has received much less attention. In this critical review, we present the state-of-the-art of water vapor sorption kinetics in wood. We first examine different experimental methods that have been used to measure sorption...

Mechanically fibrillated cellulose nanofibril (CNF) sheets of varying thicknesses were fabricated by using a wet stacking lamination technique without the use of solvents other than water or binders. The use of this technique allowed for the creation of multilayer structures with a working area of 117 mm by 117 mm and thickness of up to 0.547 ± 0.03 mm in under 2 h, which represents the shortest total processing time reported for such thickness of CNF sheets. To highlight the capabilities of utilizing wet stacking, the thickest reported 100% pure multilayer CNF sheet with a thickness of...

To avoid the use of toxic synthetic chemicals due to their potential environmental impacts, the feasibility of using heartwood extracts of Tectona grandis and Cedrus deodara as wood preservatives against the subterranean termite, Reticulitermes favipes and two basidiomycete decay fungi, Trametes versicolor and Rhodonia placenta, was investigated in laboratory experiments. There were no signifcant diferences in feeding for R. favipes fed solvent-extracted and non-extracted T. grandis in choice and no-choice tests with 100% mortality. Reticulitermes favipes ignored non-extracted C. deodara...

The future bioeconomy depends on the increased utilization of renewable lignocellulosic resources from trees and other bioenergy crops. However, considering that the diffusion of ions, chemicals, and enzymes into secondary cell walls is critical to effectively utilize lignocellulosic biomass, the unidentified mechanisms underpinning this diffusion have hindered progress. Here, nanomechanical spectroscopy was used to measure changes in moisture-dependent relaxations of amorphous polysaccharides inside loblolly pine (Pinus taeda) cell wall layers. The comparison with recent ion mobility...

Although molecular-scale wood-water interactions needed for moisture-durability can lead to the accelerated development of moisture-durable products, these interactions are often experimentally elusive. In this perspective, the topic’s state of the art understanding will be discussed, excluding computational work. Recent research efforts based on infrared spectroscopy methods have provided new insights in terms of the accessibility of the wood polymers and moisture-induced polymer dynamics. Likewise, neutron scattering and nuclear magnetic relaxometry experiments have shown that bound...

This review is a summary of the Raman spectroscopy applications made over the last 10 years in the feld of cellulose and lignocellulose materials. This paper functions as a status report on the kinds of information that can be generated by applying Raman spectroscopy. The information in the review is taken from the published papers and author’s own research—most of which is in print. Although, at the molecular level, focus of the investigations has been on cellulose and lignin, hemicelluloses have also received some attention. The progress over the last decade in applying Raman spectroscopy...

This report presents a compilation of research conducted on the life-cycle assessment analysis for processing raw material woody biomass into biochar activated carbon (AC) and synthesis gas (syngas) for electricity production. The study was part of the United States Department of Agriculture Biomass Research and Development Initiative project with a broader goal of an integrated assessment of biomass feedstock production, logistics, conversion, distribution, and end use focused on a novel thermochemical conversion system using woody biomass feedstocks. Cradle-to-grave analysis of the...

This paper discusses contributions developed at the Forest Products Laboratory that have advanced utilization of the Weibull distribution in wood engineering. The increased use of the Weibull distribution in wood engineering primarily occurred since 1975. The goals of this paper are to (1) unite, clarify, and simplify information published in several sources into a cohesive summary, (2) advance the use of this research through corrections of misinterpretations and errors of some earlier publications, and (3) introduce some potential new concerns about the use of the Weibull distribution in...

The 2nd Mass Timber Research Needs Assessment was held on November 13–14, 2018, at the USDA Forest Service, Forest Products Laboratory (FPL). The workshop was co-sponsored by FPL, WoodWorks, and the U.S. Endowment for Forestry and Communities. The purpose of the workshop was to gather a diverse group of people with expertise in mass timber, in particular cross-laminated timber, to discuss and prioritize research needed to move the mass timber industry forward in North America. The workshop was attended by more than 100 design professionals, researchers, manufacturers, industry leaders, and...

This Statistical Process Control (SPC) Handbook introduces wood preservation industry personnel to the terminology and statistical process control (SPC) tools available for understanding and monitoring industrial processes. For those who want further information, references are provided at the end of each section. The content is for educational purposes only. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the United States Department of Agriculture (USDA) or The University of Tennessee of any product or service. This Handbook...