Treesearch

Mass timber, which includes cross laminated timber, is becoming increasingly popular as a material choice for mid-level and high-rise construction. Material durability, especially in extreme exterior exposures, is a key concern of developers that has to date not been fully resolved. Data on the effectiveness of currently labeled soil termiticides, as well as spray-on borates applied either post-construction or as a remedial treatment, needs to be generated for cross laminated timber (CLT) structures. Current design standards do allow for preservative treated and naturally durable wood but...

Tannic acid (TA) is a bio-based high-molecular-weight organic molecule. Although biologically sourced, TA is a pollutant in industrial wastewater streams, and there is desire to find applications in which to downcycle this molecule. Many flame retardants (FRs) used in epoxy are synthesized from petroleum-based monomers. Various bio-based modifiers have been developed, but increasing the flame retardancy of the system without trade-offs with other properties has proved challenging. In this work, TA is incorporated into the thermoset. The molecular behavior of the system was dependent on...

Copper tolerance of brown-rot basidiomycete decay fungi can lessen the efficacy of copper-containing wood preservatives for wood products in-service. The purpose of this study was to evaluate wood mass loss and differential expression of three genes that have putative annotations for copper-transporting ATPase pumps (FIBRA_00974, FIBRA_04716, and FIBRA_01430). Untreated southern pine (SP) and SP treated with three concentrations of ammoniacal copper citrate (CC, 0.6, 1.2, and 2.4%) were exposed to two copper-tolerant Fibroporia radiculosa isolates (FP-90848-T and L-9414-SP) and copper-sens...

In order for sustainable nanomaterials such as cellulose nanocrystals (CNCs) to be utilized in industrial applications, a large-scale production capacity for CNCs must exist. Currently the only CNCs available commercially in kilogram scale are obtained from wood pulp (W-CNCs). Scaling the production capacity of W-CNCs isolation has led to their use in broader applications and captured the interest of researchers, industries and governments alike. Another source of CNCs with potential for commercial scale production are tunicates, a species of marine animal. Tunicate derived CNCs (T-CNCs)...

This study performed an environmental sustainability assessment of the wooden pallet industry in the United States using life-cycle assessment methodology. The scope of this study covered the cradle-to-grave life-cycle stages of the wooden pallet supply chain including sourcing of raw material, product manufacturing, transportation, and reuse, repair, and final disposal of pallets. The product stage was composed of raw material supply Module [A1], raw material transport Module [A2], and pallet manufacturing Module [A3]. The use and repair stage was composed of use Module [B1] and repair–reu...

Wood packing materials (WPMs) utilized by the US Department of Defense (DOD) can be constructed with a diversity of wood species depending on end use. To extend service life, these materials are treated with preservatives to protect against insects and decay fungi. Recent issues have prompted the need to include moldicide additives with these treatments. The goal of this study was to evaluate mold susceptibility across a diversity of hardwood species with the purpose of identifying representative hardwood species that would be useful in differentiating efficacy of moldicide treatments in...

Seismic force resisting systems based on cross-laminated timber (CLT) shear walls have garnered considerable attention for in mid-rise construction around the world. The purpose of this study was to determine seismic performance factors for CLT shear wall systems in platform type construction. These factors, namely, the response modification factors, R, overstrength factor, Ωo and deflection amplification factor, Cd, have been developed in this study for CLT walls and proposed for inclusion in ASCE 7. The study follows the FEMA P695 methodology that incorporates testing, evaluating a...

Improving productivity and lipid concentration in microalgae is important for the economic success of both biofuel and microalgae coproducts production. Nannochloropsis spp. are marine microalgae currently being grown at large-scale for the production of biofuel and lipid coproducts. Here we demonstrate improvements of growth and omega-3 production in Nannochloropsis gaditana CCMP526 and Nannochloropsis oceanica CCAP849/10 with plant substrate addition, a potentially economical option for increasing microalgal productivity. We examine growth in the presence of corn stover, switchgrass,...

In July, the resiliency of the U.S. housing market was a bright spot for the aggregate U.S. economy. Most month-over-month sectors were positive, and the majority of year-over-year categories were positive as well. Year-over-year, total multifamily permits, single-family housing under construction, single-family completions, and single-family construction spending indicated declines.

During adaptive metabolic evolution a native glycerol dehydrogenase (GDH) acquired a D-lactate dehydrogenase (LDH) activity. Two active-site amino acid changes were detected in the altered protein. Biochemical studies along with comparative structure analysis using an X-ray crystallographic structure model of the protein with the two different amino acids allowed prediction of pyruvate binding into the active site. We propose that the F245S alteration increased the capacity of the glycerol binding site and facilitated hydrogen bonding between the S245 γ-O and the C1 carboxylate of pyruvate....