Treesearch

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants, and many chemical adsorbents have recently been utilized for their removal. In this study, we synthesized a quaternary amine-modified (QA-CNF/DAC) composite aerogel by simultaneous cross-linking and amination of two most abundant natural polymers: cellulose nanofiber (CNF) and deacetylated chitin (DAC). The characterization results confirmed successful modification of aerogel by yielding a high surface area and quaternized amine content of 64.5 m2/g and 0.598 mmol/g, respectively. The aerogel exhibited high adsorption...

The objective of this research was to assess the potential of cellulose nanocrystals (CNCs) at laboratory scale within paving materials that make use of bituminous binders. Brittleness potential as measured by AASHTO T401 protocols was the primary evaluation mechanism where unconditioned, laboratory-conditioned, and field-aged materials were assessed. The investigation was divided into two components, neither of which are prevalent in literature or practice. The first evaluated CNCs within traditional dense graded asphalt mixed at temperatures on the order of 160°C and the second evaluated...

In this study, the modulus of elasticity of red maple (Acer rubrum) veneer, a native species abundant in eastern North America, was evaluated. These veneer sheets were 3.5 mm thick by 304 mm wide by 2.44 m long. Over 500 specimens were visually graded and subjected to a nondestructive stress wave test to determine the dynamic modulus of elasticity (MOEd). Subsequently, 60 specimens were selected for tensile testing to measure the static modulus of elasticity (MOEs). The average MOEd was 19.10 GPa, while the MOEs obtained from tensile testing was 11.88 GPa. This tension-based MOE value was...

This study investigated correlations between the mechanical properties of individual red maple (Acer rubrum) veneers and that of associated laminated veneer lumber (LVL). Veneers with an average thickness of 3.5 mm, width of 304 mm, and length of 2.44 m, were first subjected to a nondestructive test (NDT) using stress wave analysis. Dynamic modulus of elasticity (MOEd) was used to classify 480 veneers into four equal groups: high-grade, medium-grade, low-grade, and a mixed group. Each LVL consisted of 12 veneers bonded with polyurethane (PUR) adhesive. All LVL billets were evaluated...

While it is known that exposing wood to high levels of moisture, fire, or decay agents such as fungi can be detrimental for its performance, what is often missing in literature is a holistic understanding of how wood nanostructure changes due to these exposures. This is of particular interest since treatments that are meant to impart resistance can alter these length scales and/or modify their hygroscopic behavior. Yet, our knowledge of how protection treatments, such as chemical modification, alter the wood nanostructure is limited. X-ray and neutron scattering techniques are uniquely...

Deadwood is an important component of forest health and terrestrial carbon storage. However, the diversity of arthropods inhabiting deadwood and the biotic factors influencing decomposition remain poorly understood, partly due to the challenges associated with studying wood‐dwelling organisms. Ecoacoustic methods—non‐invasive and non‐destructive—offer a promising approach to investigating saproxylic arthropod communities. We tested and optimized ecoacoustic techniques (including recording duration, sensor attachment methods, and soundproofing strategies) for saproxylic detecting abundance...

In 2022, scientists from the Center for Wood Anatomy Research at the USDA Forest Products Laboratory published a field manual entitled Identification of Central American, Mexican, and Caribbean Woods. Bilingual with English and Spanish side-by-side on each page, this publication provided step-by-step processes with simple tools to enable readers with no previous experience in wood anatomy or identification to identify woods of the region. In use, the manual presented potential ergonomic challenges in both print and PDF formats. The objective of this project was to eliminate these challenges...

Near infrared (NIR) spectroscopy combined with partial least squares (PLS) regression has been widely used to predict the physical, mechanical, and chemical properties of wood. Recently, advanced modeling techniques such as deep learning and machine learning models using spectral data have increasingly been used to predict variability in wood physical and mechanical properties, but studies on chemical properties are scarce. Herein, southern pine wood samples were acquired from multiple height levels from 119 trees to yield 1007 pith-to-bark radial strips. The strips were scanned on an NIR...

This study surveyed dry kiln operations in the northeastern and north-central United States to understand current technology use and training needs. The research aimed to establish a better understanding of dry kiln production characteristics, prevailing tools and technology, and training requirements in the hardwood lumber drying industry to help providers better design training opportunities for the industry. Several different hardwood species were being dried by a majority of firms, while eastern white pine was the only softwood species dried by a majority of respondents. Key findings...

The use of downed timber from felled pine trees presents an opportunity to reduce economic losses and enhance sustainability in the forestry and construction industries. This study investigates the mechanical properties of lumber and cross-laminated timber panels from pine trees that were felled and then remained on the ground for up to 1 year. Time intervals included 0, 6, 9, and 12 months. Acoustic velocity (AV) and dynamic modulus of elasticity ( D MOE ) were used for nondestructive evaluation. Additional properties of interest included moisture content and density. After equilibration,...