Treesearch

While wood is a highly desirable building material from an ecological and sustainability perspective, we do not understand its fundamental properties nearly as well as we understand competing materials such as steel and concrete. We can avoid toxic preservatives by acetylating wood, but we don’t fundamentally understand why acetylation works. Hydroxymethylated resorcinol (HMR) can dramatically improve the water resistance of wood bonds, but no one has been able to explain the mechanism. This lack of understanding slows progress by forcing wood technology industries to rely on inefficient...

Eastern redcedar expansion is a significant economic and environmental problem in much of the Great Plains. Mechanical control measures are quite common and widely available, but application is costly and the often large piles of trees are significant issues for landowners. Biomass production from redcedar has the potential to lower costs and dispose of the material. Following field harvesting trials in 2015 and 2016, we developed production and costing tools to determine the cost and productivity for available production systems which might produce biomass chips at a cost that could be...

A special test arrangement was used to assess the flammability of 4 different wood plastic composites (WPC), most with fire retardants, all of which has a tendency to high smoke production leading to high radiant energy losses to the apparatus walls. The mass loss calorimeter (MLC) was modified to include a thermopile on the exhaust pipe stack to compensate for radiant energy losses to the wall (Figure 1) (Dietenberger, et. al.) A truncated conical electric heater provides a constant heat flux of up to 100 kW/m2 onto the test specimen of up to 50 mm thick and a spark pilot igniter. Pure...

To simulate fuel oil spills occurring during catastrophic floods, short-term absorption of two chemicals, n-hexadecane (representative of semivolatile organic compounds in fuel oil) and water, into southern yellow pine was gravimetrically monitored as a function of time at ambient conditions. Different scenarios were run on the basis of (1) the order of contamination (n-hexadecane followed by water or vice versa) and (2) whether the wood lateral sides were covered with epoxy. The experiments were designed to evaluate fast initial sorption, allowing separate estimation of the end-grain...

The carbon reports in the Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS) provide two alternate approaches to carbon estimates for live trees (Rebain 2010). These are (1) the FFE biomass algorithms, which are volumebased biomass equations, and (2) the Jenkins allometric equations (Jenkins and others 2003), which are diameter based. Here, we compare FFE and Jenkins-based carbon in aboveground live trees with the component ratio method (CRM) approach (Heath and others 2009) provided in the Forest Inventory and Analysis (FIA) database and focus on identifying where...

Copper is widely used as the primary component in wood protectants because it demonstrates a broad range of biocidal properties. However, a key concern with using copper in wood preservative formulations is the possibility for brown-rot basidiomycetes to resist the toxic effect. Many brown-rot basidiomycetes have evolved mechanisms, like the production and accumulation of oxalate, which helps these fungi to tolerate copper-treated wood by detoxifying copper. The purpose of this study was to determine if untreated wood and copper-treated wood soaked in sodium oxalate influenced the rate of...

There is a strong need to manage low-value forest residues generated from the management practices associated with wildfire, pest, and disease control strategies to improve both the environmental and economic sustainability of forestlands. The conversion of this woody biomass into value-added products provides a great opportunity to benefit both the environment and economy. This study aimed to assess the environmental impacts of converting forest residues into two renewable fuels, cellulosic ethanol and biomethane, by different biochemical conversion pathways. The energy balances and...

Gross primary production (GPP) is the Earth’s largest carbon flux into the terrestrial biosphere and plays a critical role in regulating atmospheric chemistry and global climate. The Moderate Resolution Imaging Spectrometer (MODIS)-MOD17 data product is a widely used remote sensing-based model that provides global estimates of spatiotemporal trends in GPP. When the MOD17 algorithm is applied to regional scale heterogeneous landscapes, input data from coarse resolution land cover and climate products may increase uncertainty in GPP estimates, especially in high productivity tropical...

Stress functions have been used as a complementary tool to support experimental techniques, such as thermoelastic stress analysis (TSA) and digital image correlation (DIC), in an effort to evaluate the complete and separate full-field stresses of loaded structures. The need for such coupling between experimental data and stress functions is due to the fact that experimental techniques offer discrete information of stresses or displacements, e.g. isopachic stresses in the case of TSA, as well as unreliable data near edges. For TSA, additional information is needed to separate stresses, as...

The present work aims to determine the impact performance of two bamboo-based laminated composites [bamboo/poplar laminated composite (BPLC) and bamboo/ glass fiber laminated composite (BGFLC)] using lowvelocity impact tests by a drop tower. In addition, fracture characteristics were evaluated using computed tomography (CT). Results showed that BPLC presented better impact properties in both directions than BGFLC. Three stages are noted in impact load–deflection curves. The load–deflection curve characteristics of two composites are different in different stages. Matrix cracking, fiber-matr...