Efficient use of the available wood resources is necessary to sustainably meet the long-term demand for wood products. This paper presents research about the potential of using transverse and longitudinal vibration techniques to evaluate the bending modulus of elasticity MOE (Eb) and tensile properties (Et and UTS) of 2 by 10 No. 2 grade southern pine (Pinus spp.) lumber. A total of 285 lumber pieces were first nondestructively tested using longitudinal vibration (Director HM 200), transverse vibration (Metriguard E-computer), and proof-loading bending tests (Universal Instron Machine). Each specimen was then destructively tested in tension parallel to the grain to determine tension modulus of elasticity (Et) and ultimate tensile stress (UTS). Correlations between growth characteristics, physical, and mechanical properties were analyzed. Excellent correlative relationships between longitudinal and transverse dMOE with the elastic properties Eb, and Et were found. A strong correlation was also found between the elastic properties Eb and Et. The prediction of Eb was improved after adding density to the model. The estimation of UTS was also improved with the addition of density and a secondary nondestructive measurement. Nondestructive techniques are recommended to assess the mechanical properties of southern pine 2 by 10 lumber.Abstract
The extractives contained in wood are compounds with a very high added value in various fields (e.g., pharmaceuticals, cosmetics, agri-food). These extractives can be classified into four groups: lipid components (terpenes and terpenoids), waxes and fats, phenolic compounds, and alkaloids. This review is particularly focused on the description of the main families of extractives contained in wood waste, with their properties and the potential applications made to date. It also makes a brief report on some conventional techniques for extracting wood extractives, with an eye toward recovering wood waste in our country. These extractives, particularly phenolic compounds, fall into several categories: simple phenols, lignans, flavonoids and tannins. They have chemical and biological properties such as antioxidants, antiradicals, anti-termites, antifungals, anticancer, inhibitors of type 1 human immunodeficiency virus, antimutagenics, and antimicrobial properties. They are also used in food preservation as well as wood protection. This review sums up the interest that should be focused on the availability in large quantities of wood waste in our environment, which, far from being a problem, could be the solution to certain current and future problems.Abstract
Slash pine plantation economic returns from both timber and pine straw producing perspectives were compared. Bare land values (BLVs) were calculated for site index 65 (base age 25) across three discount rates (4%, 5%, and 6%), three planting densities [545 (8 by 10 ft), 623 (7 by 10 ft), and 726 (6 by 10 ft) trees per acre], and two sets of timber prices (30-year and 10-year averages). Timber yields were obtained from the Cutover Slash Growth and Yield Simulator. Straw yields were estimated stochastically using a two-parameter Weibull distribution based on findings from a summary of pine straw yields and economic benefits in loblolly, longleaf, and slash pine stands. Straw production at an estimated average of 198 bales per acre (13 by 13 by 26 inches) improved net economic returns across all discount rates and planting densities. Increasing discount rates expectedly lowered BLVs. The BLVs varied much less across spacings, with planting at 7 by 10 ft being the preferred option. From 159 to 164 bales per acre were needed for pine straw operations to break even when planting 623 trees per acre depending on the discount rate. The distance from the average BLV to the 90th percentile was greater than the distance from the average BLV to the 10th percentile across strategies. This implied a greater potential existed for pine straw harvesting to improve BLV, but risk associated with a pine straw enterprise could reduce net income levels below simply choosing to forgo this activity.Abstract
The prospect of using mass timber products, such as cross-laminated timber (CLT), for building material has increased in recent years because of the advantage of these products over their substitutes in terms of structural rigidity, cost efficiency, and climate benefits. However, the American National Standard developed for CLT currently applies to softwood only. With the expected increase in the market for CLT, the supply chain needs to address the projected rise in demand for hardwood as well. Promoting the production of hardwood mass timber like CLT requires studying the feasibility of quality hardwood lumber supply and identifying the optimal locations for investing capital in CLT manufacturing plants. By presenting a case from Tennessee, this study provides a spatially explicit framework to use a variety of factors such as transportation networks, proximity to sawmills, sawmill capacity, and roundwood supply to identify optimal CLT plant locations. Specifically, fuzzy multicriteria analysis was used to identify potential locations, which provided inputs for a location-allocation model to identify optimal locations for CLT plants. Among the several potential locations, three optimal locations suitable for CLT plants were identified with 12,504 thousand cubic feet (MCF) annual production potential of CLT panels in Tennessee. Although increasing transportation distance for lumber procurement would increase CLT production capacity, it would also result in increased lumber supply costs. Potential investors and regional planners interested in using hardwood forest products can benefit from these findings to locate suitable sites for new investment.Abstract
Wood density is an important attribute that is positively correlated with many wood quality parameters. How to express wood density with drill resistance is a challenge. In this study, we determined the optimal resistance expression using the current, voltage, and power of the DC (Direct-Current) motor. Nine wood blocks crossing over the pith, with widths and heights of 2 cm and 5 cm, respectively, were obtained from three larch (Larix spp.) trees. The microdensity of each wood block at every 0.1-mm length was measured, and the average current, voltage, and power of the DC motor was recorded when the drill fed forward at every 0.1 mm by a self-manufactured resistance drill. The drill path was parallel to the lengthwise direction of the block. The linear models between the current, voltage, and power of the DC motor and wood microdensity were subsequently established, and the model with the highest R2adj was selected to express the resistance. The adjusted R2adj of the forward stepwise regression models between the current, voltage, and power of the DC motor and wood microdensity were determined as 0.2943. This suggests that the drilling needle resistance expressed with the current, voltage, and power or other combination may be optimal.Abstract
Pyrolysis of lignocellulosic biomass is widely used for the production of charcoal, pyroligneous liquid, and noncondensable gases. All three are value-added products that are exploited in several fields. However, this review focuses on three main areas: wood vinegar production methods, its physicochemical properties, and the use of wood vinegar or pyroligneous acid in agriculture and the environment. Wood vinegar is a liquid derived from wood by the condensation of gases and vapors released during the carbonization process, which is the transformation of wood into charcoal. It is mainly composed of aliphatic, aromatic, and naphthenic hydrocarbons and other oxygenated compounds such as alcohols, aldehydes, ketones, furans, acids, phenols, and ethers. Wood vinegar has antioxidant and free-radical-scavenging properties and is used in agriculture as an antimicrobial, antifungal, insecticide, and plant germination and growth agent. It is also used in food preservation, in medicine, and in the ecological preservation of wood. This review also examines the state of the art in pyroligneous liquid production techniques and factors that could potentially affect its quality.Abstract
Heat tensioning was proposed and proved to be effective for improving the dynamic stability of circular saw blades with ideal disk structure by a previous scholar. With the diversification of circular saw blade structure, circular saw blades with external scrapers are widely favored by the market because of their excellent resistance to sawing thermal stress. For circular saw blades with external scrapers, the effect of heat tensioning on the dynamic stability of the blades needs to be further studied. Therefore, the heat tensioning process of circular saw blades with external scrapers was built by the finite element method. The stress field and critical rotational speed of circular saw blades with a different structure after the heat tensioning process were calculated and analyzed. The relationships between circular saw blade structure, the dynamic stability of circular saw blades, and the heat tensioning process are clarified in this article. The results show that heat tensioning is not valid for all types of circular saw blades. For circular saw blades with external scrapers, the effect of heat tensioning on improving the critical rotation speed of the blades is gradually decreased with the number of external scrapers. When circular saw blades are heat tensioned, the average tangential stress of the outer edge of the blades and the critical rotation speed of the blades are higher.Abstract
The phaseout of methyl bromide (MB) fumigation creates an urgent need for an alternative phytosanitary treatment to limit the risk of international spread of the oak wilt fungus, Bretziella fagacearum. Fumigation with ethanedinitrile (EDN) is considered a potential alternative to MB fumigation to eradicate wood-inhabiting pests and pathogens. We evaluated the efficacy of EDN fumigation by comparing the rate of B. fagacearum isolation before and after fumigation of red oak (Quercus rubra or Quercus ellipsoidalis) log sections from oak wilt–affected trees. Logs (range 15.2 to 98.0 cm long; diameter 9.1 to 46.1 cm) were obtained from red oak trees that were naturally infected (NI) or artificially inoculated (AI) with B. fagacearum. The logs were fumigated for 24, 48, and/or 72 hours with 120 g/m3 EDN. Frequencies of pathogen isolation from the sapwood before treatment were higher for AI logs than for NI logs. EDN treatments greatly reduced the frequency of viable pathogen recovery, but eradication occurred only in experiments using the smallest log diameters (9 to 14 cm). Our results suggest that EDN may have limited penetration in oak logs with intact bark, similar to fumigants currently used on wood products, such as MB and sulfuryl fluoride. Results of future work may help in the understanding of the limitations for consistent and full efficacy of EDN against B. fagacearum in logs harvested from diseased trees.Abstract
The integration and development of fashion products and intangible cultural heritage have gradually become the highlight of product design. Following thousands of years of evolution, bamboo weaving patterns offer a rich resource library for use by designers. However, the designers cannot predict which bamboo weaving pattern can be adopted into women’s handbags to satisfy consumers’ aesthetics. Therefore, taking the form design of women’s handbags as an example, this study develops an artificial intelligence-based program through which consumers can codesign with designers to effectively match the bamboo weaving pattern with the design style of women’s handbags. First, based on the coding, selection, and mutation processes of interactive genetic algorithms, consumer preferences, and perception evaluations are effectively incorporated into product design. This ensures that the evolved product solutions meet consumer preferences. Second, considering evaluator fatigue in human–computer interaction evaluation, the decision tree algorithm is used as a proxy for evaluation. Finally, the developed interactive system supports mass-generated bamboo-woven bags of different styles, allowing prediction of consumers’ preferences for the design of women’s handbags. Furthermore, the system can assist designers and bamboo craftsmen in designing other bamboo or wooden products.Abstract
Reasonable assessment of the environmental benefits of integrating forest products into global value chains (GVCs) is important to promote sustainable development. Based on the forest product sector data for 41 countries from 2002 to 2014, this paper explores the impact of GVC participation on carbon embodied in exports using the 2008 financial crisis, a quasi-natural experiment of negative global value chain shocks. We found that deepening backward participation in forest product value chains led to more substantial increases in carbon emissions than did forward participation. Countries with large decreases in GVC participation reduced more carbon embodied in forest product exports after the financial crisis (relative to countries with small decreases) through a larger reduction in the scale of forest product exports, and a decrease in the growth rate of capital-intensive products as a result of the relative decline in capital investment. They increased the embodied carbon of exports through a decrease in the growth rate of skilled personnel. Strengthening the technology effect of GVCs with the guidance of skilled forestry personnel is a key way to decrease exported embodied carbon.Abstract