Treesearch

In the present study, very small concentrations of CNCs and CNFs were melt-compounded into PLA using a solvent-free process where poly(ethylene glycol) (PEG) was used to disperse the nanoparticles in PLA. As a comparison, the commercial nucleant, talc, was processed similarly into PLA. CNC and CNF were shown to be efficient nucleants for PLA, similar to talc, and conventional Avrami and Lauritzen-Hoffman analysis of the crystallization behavior was performed for isothermal temperatures from 90 °C to 130 °C across all compositions. From the Avrami analysis, the crystallization rate,...

This report summarizes information on the use of wood from hardwood species in engineered materials, components, and structures. It includes information on use in a wide variety of engineering products and applications.

This study evaluated maleic acid (MA) as a green hydrotrope for efficient wood fractionation at atmospheric pressure and ≤100 °C. MA hydrotropic fractionation (MAHF) resulted in esterified lignin with a low degree of condensation and a very light color. 2D 1H–13C HSQC and HMBC NMR analyses of reaction products of a lignin model compound guaiacylglycerol-beta-guaiacyl ether with MA identified bonding through the γ-OH group. The surface charge of lignocellulosic MAHF water insoluble solids (WIS), induced by lignin esterification (carboxylation), enhanced enzymatic sugar yield by reducing...

In the United States, wood has been traditionally used in residential construction. However, the combustibility of wood still limits its use as a building material in prescriptive building codes, and to overcome the limitations, performance‐based codes can be used. In order to properly analyze performance‐based designs, more information on the fire performance of materials is required, including fire performance under different fire exposures. The char rate when timber elements are exposed to the standard time‐temperature curve have been well characterized and can be used to determine the...

In recent years, a bioinformatics method for interpreting genome-wide association study (GWAS) data using metabolic pathway analysis has been developed and successfully used to fnd signifcant pathways and mechanisms explaining phenotypic traits of interest in plants. However, the many scripts implementing this method were not straightforward to use, had to be customized for each project, required user supervision, and took more than 24 h to process data. PAST (Pathway Association Study Tool), a new implementation of this method, has been developed to address these concerns. PAST has been...

Three compounding methods were compared to determine their effects on the organization of the interphase in nanocomposites of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and cellulose nanocrystals (CNCs) processed via (1) direct compounding, (2) reactive extrusion using a coupling agent (PHBV-g-GMA), or (3) reactive extrusion using a peroxide free-radical initiator (dicumyl peroxide, DCP). Tensile testing showed that only the peroxide-aided extrusion resulted in improvement in strength by 13%. Analyzing the interphases via DSC, WAXRD, SAXS, ATR-FTIR, and XPS helped relate the...

The energy used for regulating building temperatures accounts for 14% of the primary energy consumed in the U.S. One-quarter of this energy is leaked through ineffcient glass windows in cold weather. The development of transparent composites could potentially provide affordable window materials with enhanced energy efficiency. Transparent wood as a promising material has presented desirable performances in thermal and light management. In this work, the performance of transparent wood is optimized toward an energy efficient window material that possesses the following attributes: 1) high...

This study describes assessment of the internal conditions of timber bridge structural members along Route 66 in California. These timber bridges were exposed to desert climate conditions for several decades, which can lead to a variety of deterioration. Overtime, the deterioration may cause loss of structural integrity within the bridges and lead to potentially hazardous conditions for the motoring public. Members from dismantled bridges were brought to the Forest Products laboratory inMadison,WI. Strength-reducing features including decay, splits and cracks, insect attack, and corrosion...

An object detection method of ground-penetrating radar (GPR) signals using empirical mode decomposition (EMD) and dynamic time warping (DTW) is proposed in this study. Two groups of timber specimens were examined. The first group comprised of Douglas fir (Pseudotsuga menziesii) timber sections prepared in the laboratory with inserts of known internal characteristics. The second group comprised of timber girders salvaged from the timber bridges on historic Route 66 over 80 years. A GSSI Subsurface Interface Radar (SIR) System 4000 with a 2 GHz palm antenna was used to scan these two groups...

The use of acoustic waves for assessing wood properties in standing trees has been investigated extensively in recent years. Most studies were experimental in nature and limited to direct measurement of wave velocities in trees using a time-of-flight (TOF) method. How acoustic waves propagate in a tree trunk and how tree diameter, species, stand age, and juvenile wood affect wave propagation behavior in standing trees are not well understood. In this study, we examined propagation patterns of acoustic waves in a virtual tree trunk through numerical simulation using COMSOL Multiphysics®...