bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Pretreatment Methods for Visible–Near-Infrared Calibration Modeling of Air-Dry Density of Ulmus pumila Wood
Authors: Li Ying , Via Brian K. , Cheng Qingzheng , Zhao Jinghan , Li Yaoxiang 
Published: August 2021

Abstract
Due to the multidimensional complexity and redundancy between wavelengths in the visible and near infrared (Vis-NIR) region, the speed and accuracy of data analysis can be affected. This study aims to investigate the feasibility of simplifying high dimensional data based on transformation of the spectra and local correlation maximization (LCM). These two methods will be applied to determine the prediction accuracy of air-dry density of Ulmus pumila wood. In this study, the reflectance spectra (Refl.) were subjected to the reciprocal (1/Refl.) and logarithm reflectance to improve the spectra signal for prediction. LCM was developed for selecting spectral sensitive regions that were important in the prediction of density. A local correlation coefficient (r) criterion was developed such that if the r ≥ 0.75 (between wavelength and density), then partial least squares and support vector machine (SVM) were employed as the prediction method. Likewise, 2D correlation spectroscopy plots were used to further reduce the data matrix by removing redundant wavelengths. The results showed that (1) although the sensitive region of density was different, the region of r ≥ 0.80 was mainly in the Vis and NIR spectral region. Additionally, the performance of models developed from the sensitive region was better than that of data used from the less-sensitive region. (2) The SVM model was optimized by a genetic algorithm based on the log (1/Refl.) of the sensitive region. In conclusion, it was found that the spectral transformation presented better density estimation results ( = 0.909, root mean square error of calibration = 0.014) than when less sensitive wavelengths were used in the data matrix.
Finite Element Resonance Analysis of the Complex Structure of a Crosscut Saw Machine
Authors: Chen Wei-long , Chao Fang-lin , Lin Yu-hui 
Published: August 2021

Abstract
A crosscut saw machine must be tuned to eliminate abnormal sawing marks or skewing during rapid wood processing. Once a wooden board is placed in the feed port, it is clamped and stabilized by a roller. However, the vibration amplification of the structure still causes the relative position of the blade to change and leads to the problem of saw marks on the wood surface. This article optimizes a saw machine by modal analysis based on the finite element method. The redesigned machine was compared to the original for natural frequency and mode shape. The analysis results revealed that at 31.43 Hz, stress reached the maximum value of 383.24 MPa on the frame of an alternating current motor. The mode shape showed significant deformation of the roller frame. By applying ribs on the chassis frame, vertical bending and torsion were reduced. The frequency of the sixth mode of the original machine was 43.9 Hz, which increased to 52.9 Hz after the redesign. The results showed that this was due to the addition of the ribs. A clamping roller was able to mitigate the vibration through the +y and z directions. The natural frequency of the modality was significantly improved through rib-enforced design. The structure of the improved design exhibited improvement compared to the original machine.
Comparative Performance of Modified Solid and Composite Wood Samples in Standard Tests
Authors: Rose Robert , Leavengood Scott , Morrell Jeffrey J. 
Published: August 2021

Abstract
The properties of several modified wood products were evaluated using North American standards to provide comparative data for architects seeking to use these materials. In general, modified wood products had lower moisture uptakes and less shrinkage than unmodified products. Acetylated materials were highly resistant to fungal decay, whereas thermally modified and furfurylated materials were classified as decay resistant. All materials were susceptible to mold, although the nonacetylated moisture-resistant medium-density fiberboard was most susceptible. Thermally modified and furfurylated materials were similar in mold susceptibility to untreated radiata pine sapwood, whereas acetylated materials appeared to be more mold resistant.
Exploring the Sources of Labor Productivity Growth and Convergence among State-Owned Forestry Enterprises in Northeast China
Authors: Ning Youliang , Yu Jinna , Zhang Han , Ning Zekui , Liu Zhen 
Published: August 2021

Abstract
The state-owned forestry enterprises (SOFEs) are important producers of forest products in China, and their competitiveness depends largely on their labor productivity (LP). This article is the first to investigate the sources of LP growth and the convergence patterns of SOFEs in northeast China. Based on panel data from 87 SOFEs in northeast China from 2006 to 2018, this article has used the Cobb-Douglas production function to analyze the sources of LP growth, using three convergent methods to explore convergence patterns. The results show that there is a positive correlation between LP and an SOFE's ability to compete, and that both total factor productivity and capital-to-labor ratio significantly contribute to LP growth in all SOFEs of northeast China; however, the role of the quantity of labor was negative. On the whole, all SOFEs did not have σ-convergence in LP growth, but an absolute and a conditional β-convergence. Although the LP divergence between SOFEs in northeast China has not been narrowed, there has been a “catch-up effect” in LP growth. These results can help people understand the laws pertaining to LP growth among forest enterprises and also how they may reduce production costs, improving market competitiveness among forest products.
The Effect of Multiple Knots in Close Proximity on Southern Pine Lumber Properties
Authors: Barbosa Marcela Cordeiro , Street Jason , Owens Frank C. , Shmulsky Rubin 
Published: August 2021

Abstract
Lumber grade rules address well-spaced single-knot and combination-knot sizes. Information is lacking, however, with respect to multiple knots in close proximity. The term “well-spaced” appears to lack quantitation. This research investigates the effect that knots in close proximity (not necessarily combination knots) have on the strength properties of southern yellow pine (SYP; Pinus spp.) lumber. This study attempts to use a statistical model to determine the modulus of rupture (MOR) for SYP having multiple knots in close proximity using variables including the knot diameter (KD), amount of clear wood (CW) present, knot area (KA), and modulus of elasticity (MOE) of the lumber. This study investigated specimens of 2 by 4-inch SYP dimensional lumber exhibiting multiple knots in close proximity. The basic density (D) was determined by dividing the entire specimen weight by its volume. Third-point bending tests were used in flatwise orientation to quantify the MOR and MOE. There were significant correlations among all parameters analyzed. Multiple regression analysis with one dependent variable, MOR, and three independent variables, KD, MOE, and D, resulted in a coefficient of determination value (r2) of 0.702. When using only the MOE to predict MOR, an r2 value of 0.564 was found.
Performance of Internal Remedial Treatments on Douglas-Fir Poles: A Large-Scale Field Trial
Authors: Konkler Matthew J. , Cappellazzi Jed , Love Connie S. , Freitag Camille , Morrell Jeffrey J. 
Published: August 2021

Abstract
Internal decay is a common problem in poles or timbers of thin sapwood species. Several internal treatments have been developed to arrest this attack, and these systems are widely used in North America. Although these treatments have been evaluated in numerous independent field trials, there is no single test of all treatments. The objective of this study was to assess the chemical distribution and fungal colonization in Douglas-fir poles treated with each of 13 different internal remedial treatments over a 10-year period. Metam sodium treatments provided the shortest protective period, with little evidence of residual chemical 3 years after treatment. Methylisothiocyanate (MITC) in pure form provided a very high initial flush of active ingredient and a longer protective period extending from 5 to 8 years after treatment. Dazomet, which must decompose to produce MITC, took slightly longer to reach effective levels, but was still present at effective levels 10 years after treatment. Chloropicrin, which has strong interactions with wood, was associated with the highest chemical levels after 10 years. Borates took longer to reach effective levels in the poles and their protective zone was narrower than the fumigants, but boron was still present at effective levels 10 years after application. The results illustrate the different properties provided by each treatment, but also show that all tested remedial treatments were effective within certain limitations.
Frequency Domain Identification of Acoustic Emission Events of Wood Fracture and Variable Moisture Content
Authors: Li Xinci , Li Ming , Ju Shuang 
Published: August 2021

Abstract
The effect of moisture content on acoustic emission (AE) during wood damage was studied and the degree of damage was evaluated accordingly. In this article, the Pinus massoniana test-pieces of three different moisture content states, which are ovendried, air-dried, and water-saturated, were used to study the AE frequency characteristics of wood during bending failure. The original AE signal was subjected to wavelet denoising, and the denoised AE signal was classified into DAE (deformation AE) and FAE (fracture AE) according to the frequency distribution characteristics. Then, the instantaneous frequency of the AE signal was obtained by Hilbert transform, and the density of the two types of AE events was separately counted to evaluate the damage degree of the wood. The test results show that the AE signal in the process of wood damage and fracture was composed of two frequency components. The DAE signal frequency was concentrated at 30 to 60 kHz, the FAE signal was concentrated at 160 to 170 kHz, and the moisture content had no significant effect on the frequency distribution of AE events. In addition, the moisture content caused a change in the fracture toughness of the wood, so that the AE event density characteristics of the three damage processes were different. In particular, the ovendried test-piece showed obvious brittle fracture, and the AE event density level was slightly changed. Studies have shown that the change of AE event density based on instantaneous frequency can objectively evaluate and predict the degree of wood damage and fracture.
Effect of Elevated Temperature Exposures on Shear Properties of Sheathing Panels
Authors: Soti Rajendra , Knight Cody , Mageshwar Shanmathi , Valluri Srikar D. , Sinha Arijit 
Published: August 2021

Abstract
Structural wall sheathing such as oriented strand board (OSB) and plywood have been heavily used in residential and commercial timber frame construction. The response of these wood-based composites under elevated temperatures between 100°C and 200°C (herein referred to as elevated temperatures) and exposure time needs to be characterized to assess residual strength of the materials in the existing structures. The main objective of this work is to study the effect of temperature and exposure time on shear strength and shear modulus of plywood and OSB. A total of 110 test specimens was tested in shear after exposure to five different temperatures and two exposure durations, followed by cooling to ambient temperature. The results indicated that the plywood and OSB behaved differently after exposure to elevated temperatures and exposure duration. Plywood showed a consistent degradation of shear strength with elevated temperature and time, while OSB did not exhibit a clear picture of thermal degradation. The results further indicated that the shear modulus of plywood and OSB remained unaffected after exposure to elevated temperatures.
Unit Costs and Trends within Louisiana's Logging Contract Rate
Authors: McConnell T. Eric 
Published: August 2021

Abstract
Quarterly unit costs for a hypothetical logging firm were determined from the logging contract rate for Louisiana spanning the years 1992 to 2018. Machine rate methods were employed to disaggregate the contract rate into five cost centers: felling, skidding, loading, trucking, and tertiary (e.g., trucks, bulldozer, chainsaw). Risk was explained by the quarterly interest rate on a 30-year mortgage, and income taxes were estimated as a fixed percentage of gross income. The real logging contract rate averaged US$19.08 per ton (2018 constant dollars), and it has risen at an annual rate of 1.03 percent above that of inflation for roundwood. Trucking was the firm's highest cost activity followed by skidding, loading, felling, and tertiary. Rates of cost change followed the order of tertiary, trucking, loading, felling, and skidding. The firm faced financial hardship sporadically from 1992 through 2001, but profits were consistently returned from the second quarter of 2000 through the fourth quarter of 2006 (2000Q2 through 2006Q4). Since then, company earnings have fluctuated between profit (n = 25 quarters) and loss (n = 23 quarters). Losses were consistently generated from 2010Q4 through 2013Q2, and all of 2014, as well as in the final three quarters of 2018. Simulation of the contract rate and firm unit costs as stochastic processes utilizing a uniform distribution indicated a 0.48 probability of at least breaking even, but that increased to 0.69 when employing a normal distribution.
Variations in the Anatomical Characteristics of Bambusa pervariabilis Culms with Age and Height
Authors: Xiang Elin , Guo Yihan , Yang Shumin , Liu Xinge , Tian Genlin , Ma Jianfeng , Shang Lili 
Published: August 2021

Abstract
The anatomical characteristics of culms in Bambusa pervariabilis bamboo at different ages and heights were investigated by microscopy and image analysis. Among the two vascular bundle types found in culms, the broken-waist type was considered typical, with the following measurements: average proportion of fibrous tissue, 41.53 percent; length, 1.75 mm; slenderness ratio, 117; and Runkel ratio, 4.00. These values were close to those of the moso bamboo (Phyllostachys edulis), which is commercially relevant in China. Age and height significantly influenced the anatomical characteristics of B. pervariabilis: with an increase in age, both the length and double-wall thickness of the fiber gradually increased, whereas its lumen diameter decreased. The width of vascular bundles and the length, width, double-wall thickness, and lumen diameter of fiber markedly decreased from the bottom to the top. Therefore, B. pervariabilis is an ideal raw material for pulping and papermaking, and its performance is close to that of moso bamboo.
An Educational Needs Assessment of Workforce Supply and Readiness in Maine's Forest Products Industry
Authors: Bernsen Nicole R. , Crandall Mindy S. , Leahy Jessica E. 
Published: August 2021

Abstract
A combination of youth out-migration and lack of in-migration have led to an aging workforce and population decline in Maine, whereas simultaneous declines in pulp and paper demand and biomass utilization have had negative impacts on the perceived future of the once-dominant forest products industry. These changes may increase uncertainty among employers as to the availability and training of the next generation of forest industry workers. This study reports our findings from an analysis of workforce supply and readiness in Maine's forest products industry. To estimate possible gaps in skills and work culture, we administered a survey to current forestry students and employers in the forest products industry. Skills were assessed in three domains: soft skills, knowledge skills, and technical skills. Our gap analysis focused on the difference between the stated importance of skills to employers and the current level of skill knowledge in the workforce across all three domains. Employers identified dealing with change, motivating personnel, negotiating contracts, problem solving, and financial analysis as the top educational needs. In addition, we assessed the willingness of students to accept the culture of work within the forest products industry. Despite the anecdotes shared by employers, we did not find significant evidence of a work culture mismatch between current students and their potential future employers. We recommend that gaps related to regulations, certification standards, or log scaling be addressed through workshops or on-the-job training, whereas areas such as customer relations, marketing, or problem solving could be emphasized in academic curriculum.
Increasing Cold Tack of Polymeric Methylene Diphenyl Diisocyanate Resin with Partial Soy Flour Substitution
Authors: Asafu-Adjaye Osei , Via Brian , Banerjee Sujit 
Published: August 2021

Abstract
Partial substitution of polymeric methylene diphenyl diisocyanate resin with soy flour increases the cold tack of the resin to the level achieved by urea formaldehyde resin. The tack can be fine-tuned by adjusting the amount of soy flour added. The increase in tack is caused by the reaction of the isocyanate resin with the water contained in soy flour, as well as with hydroxyl and other groups present in soy flour components. The higher cold tack should increase the stability of pre-press mats, especially in particleboard manufacturing.
Nondestructive Evaluation of 2 by 8 and 2 by 10 Southern Pine Dimensional Lumber
Authors: França Frederico José Nistal , França Tamara Suely Filgueira Amorim , Seale R. Daniel , Shmulsky Rubin 
Published: August 2021

Abstract
This study investigated the use of two nondestructive testing (NDT) methods to evaluate the mechanical properties of No. 2 grade: 2 by 8 and 2 by 10 southern pine lumber. The dynamic modulus of elasticity (dMOE) of each specimen was evaluated nondestructively by using longitudinal vibration and transverse vibration in edgewise and flatwise directions. After the NDT evaluation, the specimens were destructively tested and correlations between static bending MOE with modulus of rupture (MOR) and dMOE were developed. The overall MOE values were 11.14 and 10.96 GPa for 2 by 8 and 2 by 10, respectively. For MOR, the overall value for 2 by 8 was 42.59 MPa, and for 2 by 10 was 43.05 MPa. As expected, results showed statistically significant correlations between static MOE and dMOE (with r ranging from 0.87 to 0.96 for both sizes tested). Also as expected, weaker correlations were found between MOR and the dMOE values (with r ranging from 0.42 to 0.57 for both sizes tested). The lower correlations are largely explained by the difference between the NDT tools analyzing each specimen's global stiffness versus MOR, which is influenced heavily by localized characteristics. Perhaps this finding occurred because larger strength-reducing characteristics are permitted in larger section pieces (2 by 8 vs. 2 by 10) and thus they have opportunity for greater variability. The continuation of studies to develop more reliable NDT is crucial to improve the evaluation of mechanical properties of southern pine lumber and is beneficial to the southern pine timber industry.
Dynamic Spillover between the Chinese and International Wastepaper Markets: Analysis of the Impact from China's Newly Implemented Wastepaper Policies
Authors: Shang Di , Li Huajing , Yao Jun 
Published: August 2021

Abstract
As China is the largest importer of wastepaper in the world and is highly dependent on the international market, the relationship between the Chinese and international wastepaper markets affects the stability of both markets. The purpose of this study was to investigate the impact of China's newly implemented wastepaper polices on the degree of integration between the Chinese and international wastepaper markets and analyze the dynamics of the relationship between the two markets over time. We developed both the static and dynamic total spillover indices to analyze the degree of integration in average and in time-varying perspectives and performed E-Divisive with Medians (EDM) on the dynamic total spillover index to evaluate the impacts of the new policies. The results revealed that the Chinese and international wastepaper markets were integrated. The calculated dynamic total spillover index varied widely during the studied period and presented an overall declining trend, indicating that these policies have disrupted the integration relationship between the two markets. The results of EDM detected structural breaks in the dynamic spillover index due to the new policies, further confirming and describing the negative impacts of the new policies on the integration relationship between the two markets. Since mutual dependence exists between the Chinese and international wastepaper markets, the interventions on the integration relationship have led to dramatic fluctuations and expanding price differences between the two markets, imposing risks and uncertainties on the stable development of China's paper industry and the global recycling industry.
Process Parameter Investigations on Poplar Wooden Brick for Indoor Partition Wall
Authors: Wang Meng , Dong Rongdan , Lu Zeguang , Jia Wanda 
Published: August 2021

Abstract
Green building materials made from waste wood fiber have attracted worldwide attention. Poplar wood fiber can be molded into indoor partition wall brick with calcium hydroxide. The best process parameters are studied by single and multifactor methods. Compressive strength increases with the decreasing poplar wood fiber content and increasing calcium hydroxide content. The best process is 310 g of poplar wood fiber, 1,849 g of calcium hydroxide, and 10 minutes of cold press time. The mass proportion of poplar wood fiber and calcium hydroxide is 14:86. Compressive strength is affected extremely significantly by the interaction of poplar wood fiber mass, calcium hydroxide mass, and cold press time. It is affected significantly by the interaction between the calcium hydroxide mass and cold press time. The results are important to effectively use poplar wood fiber.
Correlations between Grain Angle Meter Readings and Bending Properties of Mill-Run Southern Pine Lumber
Authors: Anderson Guangmei Cao , Owens Frank C. , Franca Frederico , Ross Robert J. , Shmulsky Rubin 
Published: August 2021

Abstract
Metriguard's grain angle meter (Model 511) measures grain angle in wood by assessing permittivity. This study evaluates the correlations between grain angle meter readings and bending properties of 1,400 kiln-dried 2 by 4 specimens of southern pine (Pinus spp.) lumber and considers its utility for providing supplementary data for predicting the strength of lumber. The results showed that in mill-run lumber, the correlation between grain angle and modulus of rupture (MOR) was −0.420. In addition, in graded lumber, the correlation between grain angle and MOR got progressively stronger as the grade went down. With a few technical modifications, applying this device in a mill production setting could prove useful for supplementing other nondestructive methods for assessing bending strength in lumber.
Perspectives on Ash Wood Utilization and Marketing in Anticipation of Emerald Ash Borer in Minnesota
Authors: Russell Matthew B. , Ring Elizabeth C. 
Published: August 2021

Abstract
The emerald ash borer will likely impact over four million acres of Minnesota's forests in the next 10 years. This study surveyed forest products company representatives and other natural resource professionals to understand their perspectives on the current and future use of ash in wood markets. Survey respondents indicated they were only slightly optimistic that there will be new and emerging ash markets to support the large volume of ash wood potentially available in the next 10 years; however, new technologies such as torrefaction and heat treatments were noted as potential new markets for the species.