Treesearch

Vibration can occur in wood floor systems as a consequence of a variety of human activities, ranging from common daily movements associated with individuals living in homes to high-intensity activities associated with sporting events that are held in large sports arenas. For example, the potential for harvesting energy from a wooden floor system in public buildings during daily rush hours could be substantial. In this pilot study, an energy harvesting system was developed to investigate the feasibility of harvesting energy from a vibrating wooden floor system. The purpose of this publicatio...

The polymeric angle and concentration within the S2 layer of the softwood fiber cell wall are very critical for molecular and microscopic properties that influence strength, stiffness and acoustic velocity of wood at the macroscopic level. The main objective of this study was to elucidate the effect of cellulose, hemicellulose, lignin, microfibril angle and density on acoustic velocity and material mechanical properties of 14-year-old suppressed loblolly pine. Cellulose, hemicellulose and density are consistently the most important drivers of strength, stiffness and velocity. Cellulose and...

Financial enhancement of biomass value prior to pulping requires subsequent use of remaining materials; e.g., high value use of remaining stock material after cellulosic ethanol production would improve the economics for cellulosic ethanol. In this work, use of enzymatic hydrolysis residual solids (EHRS), a cellulosic ethanol byproduct, were investigated as a bulking agent. The study examined the effect across several grammages, 20 g/m2 -200 g/m2, and EHRS substitution levels, 10%, 15%, and 20%. EHRS retention was examined with light scattering. EHRS loading increased bulk while reducing...

Although X-ray diffraction (XRD) has been the most widely used technique to investigate crystallinity index (CrI) and crystallite size (L200) of cellulose materials, there are not many studies that have taken into account the role of sample moisture on these measurements. The present investigation focuses on a variety of celluloses and cellulose containing materials—from loblolly pine wood to tunicin, and evaluated moisture-induced changes in CrI and L200. It was observed that upon introduction of a small amount of water (5%) into P2O5 dried samples, for most samples, both absolute...

The resistance drilling technique has been in focus for assessing the specific gravity (SG) of young Eucalyptus trees from plantations for pulpwood production. Namely, the data of 50 34-month-old and 50 62-monthold trees from Eucalyptus grandis × Eucalyptus urophylla clonal plantations was evaluated, while the relative resistance profiles were collected with the amplitude in a scale from 0 to 100% of each tree at the breast height. For laboratory determination of SG and moisture content (MC), 3-cm-thick disks were taken at breast height. The average resistance amplitude of a full drill...

The flexural properties of wood–plastic composite (WPC) deck boards exposed to 9.5 years of environmental decay in Hilo, Hawaii, were compared to samples exposed to moisture and decay fungi for 12 weeks in the laboratory, to establish a correlation between sample flexural properties and calculated void volume. Specimens were tested for flexural strength and modulus, both wet and dry, at 23°C and 52°C. Some specimens degenerated to only 15% of original flexural strength. UV radiation had no impact on flexural properties of field-exposed boards; loss occurred mainly on the side opposite to...

Key message Field methods for rapid determination of wood density in trees have evolved from increment borer, torsiometer, Pilodyn, and nail withdrawal into sophisticated electronic tools of resistance drilling measurement. A partial resistance drilling approach coupled with knowledge of internal tree density distribution may offer an alternative solution for wood density surveys in the future. Context Finding ways to nondestructively assess wood density in trees has been a quest by foresters and wood scientists around the world. In the past several decades, traditional increment borer...

The identification of strength-reducing characteristics that impact modulus of rupture (MOR) is a key differentiation between lumber grades. Because global design values for MOR are at the fifth percentile level and in-grade lumber can be highly variable, it is important that nondestructive evaluation technology be used to better discern the potential wood strength. In that manner, higher-performance pieces could potentially be identified and their value captured accordingly. In this study, laboratory tests of three nondestructive testing (NDT) technologies and destructive four-point...

In the beginning of 2013, the U.S. housing construction market indicated increases in all sectors; yet, by the fourth quarter’s end, only housing under construction improved. Moderation and declines are to be expected in the fourth quarter, as winter is setting in. Permits, starts, housing under construction, completions, and new and existing house sales all exceeded the record lows recorded in the 2008 to 2011 time period. With that stated, there are still several hindrances for a return to a robust housing industry, including a sluggish economy, declining real incomes, and stricter...

The U.S. housing construction market’s third quarter was subdued, as all sectors moderated or declined. Once again, consensus expectations were for aggregate housing market gains, and these expectations were not realized. Overall starts, housing under construction, and completion data indicated quarterly improvement. Viewed from a recent his¬torical context, all housing construction subsectors exceeded the record lows observed in the 2008 to 2011 time period.