Annual new housing starts in the United States decreased dramatically between 2005 and 2012. Consequently, products that are heavily tied to new housing starts, such as flooring, cabinetry, and moulding produced from Appalachian hardwoods, have suffered a corresponding decrease in demand. There may be opportunities to increase demand for these products, however, as demand in the green building sector increases. The present study evaluated the demand for certified wood products (CWPs) and green-labeled wood products in the central Appalachian affordable housing sector in 2011. The study also identified price premiums that affordable home builders were willing to pay for CWPs and green-labeled wood products. Results indicated that 50 percent of affordable housing respondents were planning future CWP purchases. Results also indicated that 62 percent of affordable housing respondents followed some type of green building standard. Additionally, more than 70 percent of affordable housing respondents suggested a willingness to pay an additional percentage for CWPs and local wood products. The use of CWPs was found to result from a combination of builder and homeowner preference. Last, of the housing builders who looked to purchase CWPs locally in 2011, only 17 percent were not able to locate the materials for purchase. The low percentage of unsuccessful procurement suggests CWPs are well distributed in areas near affordable housing projects in central Appalachia.ABSTRACT
Using wood wastes provides an opportunity to avoid fossil carbon emissions from the combustion of natural gas or other fossil fuels. Using a life-cycle assessment, a new biomass boiler sourced by forest residuals, sawmill residuals, and clean demolition material (CDM) was compared with an existing natural gas boiler for supplying heat to a large-scale district heating system. Potential alternative uses of these feedstocks, such as recycled or reprocessed products, and landfill alternatives were also evaluated for their relative impact on carbon emissions. We found a reduction in emissions from natural gas of 0.62 unit of carbon for every unit of carbon in the wood combusted. Temporary losses of forest carbon after initiating the collection of forest residuals were minimal over a short interval. These losses were more than offset by the joint production of wood products displacing fossil emissions. Carbon mitigation in the Pacific Northwest was increased from 5.5 metric tons/ha/y from the production of forest products with no collection of forest residuals to 6.5 metric tons/ha/y after completing the first rotation, an 18 percent reduction in fossil emissions per hectare of forest. The potential to recycle CDM into wood products may ultimately raise the efficiency in avoiding carbon emissions by 40 to 60 percent, although available wood quality and logistics currently favor use of CDM as biofuel feedstock. In the absence of any “incentives” or value for carbon mitigation, feedstock collection costs relative to low-cost fossil fuel will substantially limit the use of waste woods for biofuel or recycling alternatives.ABSTRACT
The use of wood waste for heating in urban settings provides an opportunity for communities to reduce annual fossil emissions by directly reducing the amount of fossil fuel used. Life-cycle assessments (LCA) comparing the environmental impacts of alternative processes or products provide the essential information to better understand opportunities for improvement. An LCA was performed on a Seattle, Washington, district heating system that provides thermal energy to a large number of buildings in downtown Seattle. This study presents annual impacts in terms of carbon emissions for heat production generated using a new boiler design fuel mix including wood wastes as well as natural gas. Results are compared with the results from the 100 percent natural gas boiler that was previously used. The LCA includes results from both a life-cycle inventory of all inputs and outputs and a life-cycle impact assessment comparing alternatives. Results show that global warming potential (GWP) was reduced by 57 percent for the mix fuel design boiler compared with an all natural gas boiler. When 100 percent woody biomass is used, the reduction increases to 104 percent. Transportation and collection of feedstocks contributed minimally (8%) to the overall impact, while the combustion life-cycle stage accounted for 92 percent of the total GWP.ABSTRACT
Brown stain makes the appearance of ponderosa pine shop lumber look dark, streaky, and splotchy, which often results in lumber downgrading. When brown stain occurs in a piece of shop lumber, it is often sorted separately and ultimately sold for a discount. Manufacturers of ponderosa pine shop lumber have adopted low-temperature dry kiln schedules to mitigate brown stain effects. The low-temperature schedules are lengthy, often taking more than 100 hours of drying time. Preliminary high-temperature (>212°F [100°C]) drying schedules have reduced drying time while minimizing brown stain effects. The purpose of this study was to further explore drying schedules with high temperatures early in the schedules followed by conventional drying settings. Results showed that 10 hours of initial high-temperature drying can be used without brown stain affecting the visual grades of ponderosa pine shop lumber while reducing drying time up to 17 percent.ABSTRACT
Efficient use of sapstain control products requires information on the effectiveness of the actives and formulations against different types of fungal challenges. The present work examines sapstain control product efficacy against spores, approaching mycelia, and established mycelia in laboratory experiments, and against preinfection in field experiments. Laboratory experiments found that 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT)/2-methyl-4-isothiazolin-3-one (MIT), 3-iodo-2-propynylbutylcarbamate (IPBC), and propiconazole applied prior to exposure to mold fungi were most effective against spores, less so against approaching mycelium, and least effective against live mycelia already present in wood prior to treatment. Field tests confirmed that sapstain was more difficult to control on wood preinfected with sapstain and mold. Although short periods of exposure prior to treatment may not affect efficacy, any delays between manufacture and treatment increase the risk of preinfection and should be avoided.ABSTRACT
The effect of cutting speed on surface quality of black spruce (Picea mariana (Mill) B.S.P.) cants produced by a chipper-canter was evaluated. Four cutting speeds (18.9, 21.3, 24.2, and 27.1 m/s) were tested while feed speed was adjusted to obtain the same nominal chip length of 27.5 mm for each condition. For each speed, 15 logs were processed under frozen and unfrozen wood temperatures using 25 mm of cutting width at their small end. The surface quality was analyzed according to roughness and waviness standard parameters and to the depth of torn grain. The results showed that surface quality was not affected by the cutting speed. In contrast, surface was affected by the temperature of the logs and was better under unfrozen conditions. Quality of cants was also better at the small end of the log and generally at the upper part of the cant.ABSTRACT
The goal of this study was to investigate the effects of thinning and fertilization on mechanical properties of loblolly pine (Pinus taeda L.) strands associated with growth ring number and height. A systematic link to forest management, anatomical properties, and mechanical properties was obtained by correlating the test results with anatomical properties. The modulus of elasticity (MOE) and ultimate tensile strength (UTS) of strands from three loblolly pine trees increased with the increment in growth ring number, whereas the MOE and UTS showed different trends with the increment in height. Prediction of the MOE and UTS with specific gravity for the trees seemed to be unreliable. A natural tree had the greatest correlation between tangential latewood cell wall thickness and the mechanical properties. A thinned tree had the greatest correlation between ring width and the mechanical properties. A fertilized tree had the greatest correlation between density and the mechanical properties. However, the correlation between a specific anatomical property and mechanical properties was weak. Different combinations of anatomical properties predicted MOE and UTS of loblolly pine strands from different forest-managed trees more closely, indicating an R2 of 0.84 to 0.95.ABSTRACT
Owing to the constant increase of prices of the process for petrochemical resin and the possibility of harmful formaldehyde emissions from industrial produced medium-density fiberboards (MDF), enzymatic binder systems are discussed as an environmentally friendly alternative for gluing lignocelluloses such as wood fibers. In this work laccase-mediator systems (LMSs) were used to activate the lignin on wood fiber surfaces. Two different mediators were tested, vanillic acid (VAN) and 4-hydroxybenzoic acid (HBA), of which HBA performed best. Carbon-13 nuclear magnetic resonances (13C-NMR) and electron spin resonances (ESR) of LMS-treated thermomechanical pulp (TMP) fibers were determined for qualitative and quantitative analysis of lignin activation. Analysis outputs were transferred to produce MDF using a dry process. 13C-NMR revealed more structural changes in the wood fibers using LMS with HBA than LMS with VAN. ESR spectroscopy indicated a higher amount of phenoxy radicals after treatment with LMS containing HBA as a mediator. The data correlated well with the quality of MDF. The best mechanical technological properties were achieved by using HBA within the LMS, so that the European Norms could be fulfilled. But VAN also performed well, which showed a high potential to produce ecofriendly MDF by using LMSs in the future.ABSTRACT
To utilize agricultural and forestry wastes and to improve environmental protection, polypropylene (PP) wood–plastic composites were prepared with rice straw powder by using two methods of formation. The effects of formation conditions and rice straw powder content on the mechanical properties, water absorption, and moisture absorption performance of the composites were studied. The tensile sections of the composites were observed by using a stereo-microscope. The results showed that the mechanical properties, water absorption, and moisture absorption performance of the composites formed by mixing compression molding were better than those obtained by layer compression molding. Mixing produced more uniform blending of PP with the fiber compared with using layers of PP with powder. With a rice straw powder content of 50 percent, composites formed by mixing compression molding had good mechanical properties, water absorption, and moisture absorption performance.ABSTRACT
Western Himalaya has a very rich heritage of medicinal and aromatic plants. Nardostachys grandiflora is among the highly renowned medicinal and aromatic plants of this region. It is harvested for its rhizome, which is used to treat diseases such as heart palpitation, convulsions, epilepsy, and insomnia and also used as a source of aromatic oil that is used as incense, as a flavoring agent, and in quality perfumes. This species is on the verge of extinction due to overexploitation and habitat destruction. Due to its remote location as well as sparse population, scientific investigations on this species are sporadic and fragmentary. Trade-related information on this species is also scanty and fragmented. However, such studies are important because they provide insight into the scientific information available, even if meager, with a view to determining the gaps that need to be addressed in the future. This article tries to consolidate all the available information into a single compilation. A previous article along similar lines (G. Amatya and V. M. Sthapit, J. Herbs Spices Med. Plants 20:39–47, 1994) is now about two decades old and needs to be updated in the light of research conducted in the last two decades.ABSTRACT