Treesearch

This paper examines the strength of wood adhesive bonds at high temperatures. The goal of this research is to better understand the conditions of heat delamination in cross laminated timber (CLT) that is exposed to fire. Heat delamination in CLT occurs when one lamination detaches from the composite panel before the char front reaches the bondline. Timber that falls from the panel, as a result of delamination, contributes additional fuel to the fire, which can cause fire regrowth, while the loss of a lamination causes a sudden loss in strength. Currently, to demonstrate that an adhesive...

This research presents the development of a mass timber buckling restrained brace (T-BRB) that combines a low yield strength steel core with a mass timber casing to create a new ductile fuse. The T-BRB is an essential element of a mass timber buckling restrained braced frame (BRBF), which is a promising mass timber wood lateral force–resisting system. Critical elements of T-BRB design that are important for good performance include casing stiffness, casing material, number and spacing of bolts, timber spacer and casing gap, steel core yield strength, and friction between steel core and...

Synthetic polymers are ubiquitous materials widely used in construction, automotive, electronics, and countless commercial products. With the growing trend of polymer applications in everyday life, upholding the rigorous fire safety regulations has become a matter of concern. In this regard, numerous studies have been conducted for improving the fire retardancy of polymers, mainly through incorporating a diverse group of fire-retardant compounds into polymer-based composites. This review article aims to present a comprehensive overview of recent advances in the fire-retardant categories...

Lignin as a polyphenolic non-toxic bio-renewable polymer has been considered a promising candidate to replace phenol a relatively costly and toxic substance to reduce the carbon footprint and cost of phenolic resins. A detailed look at the current status of research in regard to ligninbased resins is presented. The discussion includes resins synthesized using lignin sourced from traditional pulping processes and the more recent biorefinery-based technologies, as well as the challenges facing lignin valorization

The multi-scale hierarchical structure of tooth enamel enables it to withstand a lifetime of damage without catastrophic failure. While many previous studies have investigated structure-function relationships in enamel, the effects of crystal misorientation on mechanical performance have not been assessed. To address this issue, in the present study, we review previously published polarization-dependent imaging contrast (PIC) maps of mouse and human enamel, and parrotfish enameloid, in which crystal orientations were measured and displayed in every 60-nm-pixel. By combining those previous...

Switchgrass was fractionated using maleic acid (MA) as an acid hydrotrope in comparison with p-toluenesulfonic acid (p-TsOH) at atmospheric pressure. MA achieved more rapid and greater maximal dissolution of lignin and hemicelluloses (88 % and 63 %, respectively) than did p-TsOH (73 % and 55 %, respectively). MA esterified (carboxylated) the dissolved acid hydrotropic lignin (AHL) as evidenced by 2D 1 H-13C HSQC NMR analysis, which improved AHL antioxidant ability compared with AHL from p-TsOH that is not carboxylated. MA also carboxylated the lignin and cellulose in the fractionated...

This work proposes the application of dicarboxylic acid cellulose nanofibril (DCA-CNF) obtained through maleic acid hydrolysis as an additive in water-based drilling fluids (WBMs). Specifically, the use of DCA-CNF as a replacement of xanthan gum (XGD) in the WBM formulations was evaluated. The effect of DCA-CNF on the main functional properties of WBMs and their performance was evaluated and compared with that corresponding to XGD. To this end, interactions between DCA-CNF and bentonite (BT), as well as between DCA-CNF and polyanionic cellulose (PAC), were studied using quartz crystal...

The meat industry in the US generates considerable amount of slaughterhouse waste (SHW), which is typically converted into more useable products through the rendering process. Although rendering generates sellable fat and meal commodities, it has large environmental impacts because it is energy intensive. Anaerobic digestion (AD) is a promising technology for treating SHW and reducing environmental impact through biogas production to generate heat or electricity, as well as by enabling nutrient recovery and pathogen reduction. This study compared the life-cycle energy use and global...

he Forest Products Laboratory (FPL), part of the USDA, in Madison, Wis., along with its new satellite laboratory in Starkville, Miss., have been involved in the examination and testing of wood preservative systems to improve durability of railroad ties and other wood products for the last 110 years. In keeping with the spirit of a pragmatic approach to research, FPL continues to devote a signifcant portion of its efforts toward applied research in wood preservation, often in collaboration with industry and university partners. In September of 2018, the FPL Starkville group partnered with...

Lignin is a multifunctional biopolymer with high application potential in the synthesis of thermoplastic materials. Industrial and investigational lignins have been incorporated into various commercial polymers, including biobased polymers, to improve their biodegradability, cost, and thermomechanical stability. Lignin is also expected to bring additional beneõts to the formulations, such as ôame retardancy, UV-protecting ability, and antioxidant and anti-weathering capacity. Strategies focused on lignin size reduction, fractionation, and modiõcation via esteriõcation, etheriõcation, and...