Treesearch

The regulation of building materials and products for flammability is critical to ensure the safety of occupants in buildings and other structures. The involvement of exposed building materials and products in fires resulting in the loss of human life often spurs an increase in regulation and new test methods to address the problem. Flammability tests range from those in which the sample is ground to a powder prior to testing to the full-scale room corner test. Variations in test methods include the specific measurement of flammability parameters being considered, the intensity and...

The purpose of this research was to investigate the total number of pallets that end up in landfills in the United States as well as to gain a better understanding of the overall waste stream. This research was conducted by mailing all of the licensed Municipal Solid Waste (MSW) facilities in the continental United States a questionnaire that included the option to complete the survey online. The questionnaire that was sent to the landfills was built upon previous surveys conducted by researchers at Virginia Tech in both 1995 and 1998. The results indicated that an estimated 249 million...

Pyrolysis is a promising technology for converting lignocellulosic biomass into chemicals, materials, and fuels. Understanding the fundamental reactions and mechanisms during the fast pyrolysis of lignocellulosic biomass is essential for improving the efficiency of this technology. Investigations of lignin fast pyrolysis reactions and mechanisms have thus far lagged relative to cellulose and hemicellulose and have largely been focused on lignin model dimers and monomers. These studies provide valuable information about the reaction tendencies of individual linkages; however, the complex...

Diferuloylputrescine has been found in a variety of plant species, and recent work has provided evidence of its covalent bonding into lignin. Results from nuclear magnetic resonance spectroscopy revealed the presence of bonding patterns consistent with homo-coupling of diferuloylputrescine and the possibility of cross-coupling with lignin. In the present work, density functional theory calculations have been applied to assess the energetics associated with radical coupling, rearomatization, and dehydrogenation for possible homo-coupled dimers of diferuloylputrescine and cross-coupled...

This paper models bench-scale experiments using computational fluid dynamics (CFD). The experiments measured the temperature profiles of fire-protected cross laminated timber (CLT) specimens exposed to parametric fire curve. The bench-scale experiment specimen is 250 x 250 mm and consists of a CLT panel 100 mm with three layers of gypsum plasterboard 15.5 mm as thermal and fire insulation The specimens were exposed to a heat flux generated by a heat-transfer rate inducing system (H-TRIS) device. Two numerical models were created in order to copy the experiment conditions, one by using...

The month-over-month and year-over-year housing data for September were mixed. Single-family permits and starts, harbingers for current and future construction, were negative month-over-month and year-over-year. Completions remained slowed due to the unavailability of building materials and products, among other factors. Total and single-family housing under construction were the only categories positive on month-over-month and year-over-year bases.

The forest landscape of the Southeastern Atlantic coastal plain of the United Statesis experiencing increased threats from extreme precipitation events, tropical storms,flooding, droughts, and growing urbanization impacting on vegetation, road infrastructure,water extraction and other related ecosystem processes (e.g., storm runoff,nutrient and carbon cycling) and functions (e.g., flood protection, aquatic habitat).We describe ongoing hydro-meteorologic monitoring on two first-(1.6 km2 each),the second-(5 km2), and the third-(52.5 km2) order catchments. The catchments arelocated on the...

The long-term viability of United States (US) agriculture and food systems is contingent upon sustainable soil and water conservation. Currently, the majority of conservation practices rely on voluntary adoption by farmers. However, a large and growing proportion of farmland is rented, thereby presenting a conservation decisionmaking context where tenant farmers have less control over conservation behavior than farmers who own the land they operate. For decades, social science scholarship has examined whether and how land tenure affects farmers’ conservation behavior. The overall effect of...

Running buffalo clover (Trifolium stoloniferum; RBC), is a recently delisted stoloniferous species that occurs in several eastern states of the United States. Once thought to be extinct, RBC was rediscovered in West Virginia in 1985 and it is generally accepted that it requires moderate disturbance and filtered sunlight to grow. We studied how light availability and photosynthetic parameters are related to stolon production and overall plant growth. We sampled six occurrences in the USDA Forest Service Fernow Experimental Forest (Parsons, WV) in September 2018. For each occurrence, we...

If periodically outbreaking forest insects are a generic source of forest decline, then why do outbreaks recur more periodically than decline episodes? Do standard field survey data and proxy data systematically underestimate the complexity in herbivore population dynamics? We examine three sources of previously un-analyzed time-series data (population, defoliation, and tree-ring radial growth) for the forest tent caterpillar, Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae) feeding on trembling aspen, Populus tremuloides Michx. (Salicaceae), in Minnesota, in order to answer these...