bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of the Mountain Pine Beetle on Sawmill Operations, Costs, and Product Values in Montana
Authors: Loeffler Dan , Anderson Nathaniel 
Published: August 2021

Abstract
Over the past 20 years, the mountain pine beetle (Dendroctonus ponderosae) has caused considerable tree mortality across the Rocky Mountain region of the western United States. Although the operational and cost impacts of dead timber are generally well known in the sawmill industry, there remains a need to better understand the impact of large-scale outbreaks on the industry at local and regional scales. Using an expert opinion survey of sawmill managers and procurement staff, this study quantified the relative importance of various cost and operations factors related to harvesting and processing beetle-killed timber in Montana. Respondents reported an average log supply of trees in the red or gray stage of mortality as 24.5 percent of log supply from 2010 to 2014, but this dropped to 5.8 percent by 2015. Cracking and checking were perceived as having the highest negative impact on log value, while waste in milling and breakage of logs in handling were ranked highest for milling operations. For a typical lodgepole pine stand, the volume estimated as sawlogs showed a 15 percent decrease between green and red stages and a 50 percent decrease between red and gray stages, with most of the volume change moving into the pulpwood category. Total average cost increases from green to gray for logging, loading and hauling, and sawmilling were 43, 46, and 46 percent, respectively. Results generally support known relationships between defects, costs, recovery, and value, with some interesting departures with regard to blue stain and equipment maintenance.
Effect of Different Hydrothermal Treatments (Steam and Hot Compressed Water) on Physical Properties and Drying Behavior of Yellow-Poplar (Liriodendron tulipifera)
Authors: Rahimi Sohrab , Singh Kaushlendra , DeVallance David 
Published: August 2021

Abstract
Nonchemical high-pressure steam treatments have been intensively researched and commercialized to produce chemical-free wood products with enhanced properties. However, the utilization of high-pressure steam involves vapor-phase reactions using high-temperature steam generated at the expense of high energy input. In this research, influences of reaction media (steam and hot-compressed water) and temperature (100°C and 140°C) during thermal treatment on physical properties and drying behavior of yellow-poplar (Liriodendron tulipifera) heartwood were compared. The length, width, and thickness of the samples were 22.53 mm, 17.18 mm, and 16.72 mm, respectively. After the treatment, the samples were dried under an isothermal temperature condition of 105°C. Data on moisture content and time of drying from drying experiments were fitted with unsteady-state molecular transport equations to calculate overall liquid diffusion coefficients. Dimensions, weight, and true volume of samples were measured for green, thermally treated, and dried samples and the values were used to calculate selected physical characteristics. Additionally, selected mechanical properties were evaluated for samples conditioned to 13 percent moisture content. Results showed that intensified hot-compressed water-treated and control samples had the highest and lowest saturated moisture contents (101% and 44%), respectively, immediately after treatments. Intensified steam-treated and control samples had the highest and lowest total porosity (95% and 82%), respectively. Furthermore, mild hot-compressed water-treated samples showed the greatest compression strength (47.8 MPa) at 13 percent moisture content. Except for steam treatment at 140°C, other treatments significantly decreased the diffusion coefficient. Collectively, samples treated with hot-compressed water at 100°C showed the most improved mechanical properties.
Characterizing Star-sawn Pattern–Produced and Orthogonally Glued Specimens of Southern Pine
Authors: Cao Guangmei , Shmulsky Rubin , Liu Ming , Entsminger Edward D. , Via Brian K. , Wan Hui 
Published: August 2021

Abstract
In this study, triangular specimens of southern pine (Pinus spp.; SP) generated by a star-sawn process were characterized according to knots and deformation. SP specimens were used to understand the differences among glue-line combinations of radial-to-radial, radial-to-tangential, and tangential-to-tangential faces bonded with phenol resorcinol formaldehyde resin. The specimens were tested for shear strength, dimensional stability, wood failure, and delamination rate in accordance with ASTM D1037 and D2559 standards. Among the star-sawn triangular samples studied, bows in tangential-face sections occurred the most. The radial-face sections of SP triangular specimens had more knots but a much lesser degree of deformation than the tangential-face sections. The tangential-to-tangential face glue-line samples showed a lower shear strength, more wood failure, and a greater tendency of delamination and dimensional change, especially when subjected to wet conditions. Confocal microscopic pictures revealed that the tangential-to-tangential glue line showed a greater tendency of deformation in the earlywood part and helped to explain the reason for poor glue-line durability and low shear strength. This article revealed that the star-sawn–process generated wood radial-face samples were more stable than others tested and are perhaps a good alternative for massive panel manufacturing.
Producing Spalted Alder Wood in Yunnan, China
Authors: He Haishan , Gan Changtao , Kuo Monlin , Qiu Jian , Wu Jianrong 
Published: August 2021

Abstract
Given the demand for environmentally friendly wood stains, dyeing by fungi has come to light as a suitable process for staining wood, textiles, and other materials. The identification of fungi capable of producing spalted wood merits considerable effort by researchers, and some spalted color or styles found on wood in the wild cannot be cultivated in the laboratory. To find additional fungal candidates and styles for spalting in China, we here collected and identified wood fungi in Yunnan and Guangxi in China. Fungi were purchased or isolated and then inoculated to alder wood blocks (Alnus nepalensis D. Don). Out of seven purchased strains, three formed zone lines, but it was unclear whether Chlorociboria aeruginascens cfcc 87397 could do so. Out of 20 strains, 15 species were isolated from wood forming zone lines with surface black pigments, and only Diaporthe sp. ZXH63-4 formed additional yellow pigments accompanied by zone lines throughout the wood, which is a new means of forming yellow pigments and black zone lines at the same time. Some fungi collected from stained wood samples showed reddish-brown zone lines, but they showed black zone lines when isolated and inoculated on alder.
Simulation and Evaluation of Coordination Mechanisms for a Decentralized Lumber Production System with Coproduction
Authors: Dumetz Ludwig , Gaudreault Jonathan , El-Haouzi Hind Bril , Thomas André , Lehoux Nadia , Marier Philippe 
Published: August 2021

Abstract
Sawmilling activities in softwood mills (i.e., wood-sawing, drying, and finishing) cannot be efficiently planned at the operational level in a centralized manner because of the complexity of the production process. Sawmills plan their activities in a decentralized manner (although they try to coordinate them). Thus, specific mathematical models have been developed over the years to support planning for each activity. In the literature, these planning models are usually evaluated and tested independently, or connected using heuristics and evaluated for a fixed demand–planning horizon, assuming a known demand for the entire planning period. In this study, we simulate the use of planning models for decentralized sawmill production, but in a context where new orders arrive randomly and replanning is carried out periodically using a rolling horizon. We also simulated and evaluated different coordination mechanisms at the operational level, highlighting that previously published coordination mechanisms for decentralized planning of sawmilling operations may lead to a low order-fill rate when used in such a dynamic environment. We then propose a more advanced push–pull coordination mechanism based on the concept of decoupling point, revealing that this new mechanism may be more appropriate regarding the market characteristics considered in the study, while leading to a sales increase and reduced inventory. Actual numbers vary depending on specific market conditions.
Effect of the Layer Structure of Wooden Floorings on Dimensional Mobility under Different Relative Humidity and Water Retention Conditions
Authors: Kureli Ihsan , Dongel Nihat 
Published: August 2021

Abstract
This study aimed to determine the effect of different wood flooring layer structures and surface features on water intake, shrinkage, and swelling rates under different relative humidity and water retention conditions. Nine wood flooring sample types were tested: solid wood beech (Fagus orientalis L.) flooring covered with polyurethane varnish, four engineered wood flooring types having different core-layers (solid-wood poplar (Populus nigra L.), 2× medium-density fiberboard, and plywood) covered with ultraviolet dried polyurethane varnish on beech veneer, and four laminated wood flooring types having different core layers (high-density fiberboard, medium-density fiberboard, particleboard, and plywood). The results showed the lowest water retention increase rates for 2 and 24 hours in the high-density fiberboard and medium-density fiberboard core-layered laminated wood floorings. The lowest thickness swelling rate occurred in the laminated wood flooring with a plywood core layer during exposure to high relative humidity, whereas the lowest swelling rate in the width dimension occurred for laminated wood flooring compared with other product types. The lowest thickness shrinkage rate was in the poplar core-layered engineered wood flooring, whereas the lowest shrinkage rate in the width direction was in the medium-density fiberboard core-layered engineered wood flooring and plywood core-layered laminated wood flooring at lower relative humidities. In conclusion, high-density fiberboard and medium-density fiberboard core-layered laminated wood floorings are advisable for flooring exposed to a humid environment. All laminated wood flooring types provided good resistance to swelling. The plywood core-layered laminated wood floorings, poplar, and medium-density fiberboard core-layered engineered wood flooring types performed the best for low-humidity environments.
The Effect of Modifier on Properties of Bamboo Powder/High-Density Polyethylene Composites
Authors: Hu Xiaoxia , Chen Zhenghao , Cao Yang , Chen Zhangjing , Zhang Shuangbao , Song Wei 
Published: August 2021

Abstract
The focus of this study was to observe the properties of bamboo plastic composites modified with a self-made modifier, 18 acyl-dopamine (0, 0.25, 0.50, 0.75, 1.00, and 1.25 weight percent [wt%] based on the dry weight of bamboo powder). The effects of the modifier were demonstrated by measures of mechanical properties, water absorption, thermal stability, and scanning electron microscopy (SEM). The results revealed that 18 acyl-dopamine could be used as an effective modifier of bamboo powder/high-density polyethylene composites. When the modifier was increased, the toughness of the composite deteriorated, and the strength and rigidity improved. This indicated that when the dosage became higher, the compatibilization became stronger, and the toughening effect became worse. Based on the experimental data, a small dosage modifier acted as a toughening agent; as the dosage increased to 1.0 wt%, the compatibility began to appear. The modifier reacted with the hydroxyl groups on the surface of the bamboo powder, which caused the bamboo powder to absorb less water, so the thickness expansion rate was lowest at 1.25 wt%. The pyrolysis peak of bamboo powder and plastic showed a tendency to be close to each other, indicating that the interface was improving. Based on the equation of Flynn-Wall-Ozawa, as the dosage of the modifier increased from 0.50 to 1.25 wt%, the apparent activation energy also increased. The SEM analysis showed the binding between bamboo powder and the plastic matrix was strongest when the modifier dosage was 1.25 wt%.
Connection Performance of Mass Plywood Panels
Authors: Miyamoto Byrne T. , Sinha Arijit , Morrell Ian 
Published: August 2021

Abstract
Tall wood buildings have become more prevalent in North America in the past 10 years. Tall wood-frame buildings implement both mass timber construction and products. Mass timber products are wood-based products that can withstand and hold large loads for long durations of time. Mass timber has allowed for large buildings, which consist mainly of wood, to be erected comprising multiple stories. One new mass timber product that has been fashioned is Mass Plywood Panels (MPP). MPP is a veneer-based engineered wood product, which is a massive, large-scale, structural composite lumber–based panel designed for use in building applications as both a vertical and horizontal element. For any new product to be used in the industry with confidence, a thorough investigation of its physical, mechanical, and connection properties is needed. A series of connection tests, such as fastener withdrawal resistance, dowel-bearing strength, lateral resistance, and a component test on a wall-to-floor system were conducted. The lateral resistance test indicated that the current European Yield Models can be used to calculate the yield loads and yield mode of the MPP by using the dowel-bearing strength of plywood. Three different connection configurations were tested in two distinct loading directions—shear and withdrawal. Their performances are evaluated and compared using two existing engineering models—namely, the American Society of Civil Engineers 41-13 tri-linear model and the seismic analysis of wood-frame structures 10-parameter connection model.
Compressive Strength Parallel to the Grain in Relation to Moisture Content in Calamus simplicifolius Cane
Authors: Yang Limei , Liu Xing'e , Jiang Zehui , Tian Genlin , Yang Shumin , Shang Lili 
Published: August 2021

Abstract
This research aimed to investigate the compressive fracture behavior and the compressive strength parallel to the grain in relation to moisture contents (MC) below and above the fiber saturation point (FSP) in Calamus simplicifolius cane. FSP of the rattan was investigated using a dynamic vapor sorption (DVS) apparatus, and the fracture behaviors of compression parallel to grain were analyzed by three-dimensional X-ray microcomputed tomography. The study indicated that the value of FSP derived from the DVS method was 25 percent. The average compressive strength parallel to the grain was found to be 39 MPa at 3 percent MC, 30 MPa at 10 percent MC, 17 MPa at 12 percent MC, 12 MPa at 27 percent MC, and 10 MPa at 45 percent MC. The strains of the yield and densification stage were prolonged with increasing MC, whereas the stress in the linear elastic stage decreased with increasing MC. The cracks of the rattan core and the deflection angle at higher MC were larger than that of low MC. Below the FSP, the compressive failure of the rattan showed a shear band oriented around 45° to the loading axis, and the surface was rough. Above the FSP, the rattan samples showed brooming failure. The interface among fiber bundles was delaminated and the fiber surface in the failure area was smooth. The fracture toughness of the rattan was higher than that of wood, which suggests that the rattan might be more suitable for modeling and curved materials.
Effect of Alkaline Copper Quaternary Type D on Color Retention, Mold Resistance, and Surface Physicochemical Characterization of Neosinocalamus affinis Bamboo
Authors: He Lu , Chen Lin , Xie Jiulong , Qi Jinqiu , Jiang Yongze , Xiao Hui , Chen Yuzhu , Huang Xingyan , Tu Lihua , Shupe Todd 
Published: August 2021

Abstract
The effect of alkaline copper quaternary type D (ACQ-D) treatment on color retention, mold resistance, and surface physicochemical characterization of Neosinocalamus affinis bamboo was analyzed. The results showed that a treatment of 0.25 percent ACQ-D solution combined with pretreatment of potassium hydroxide and sodium dodecyl sulfate mixed aqueous solution can achieve a desired green color on the bamboo surface. The mold test result revealed that the treated bamboo samples had better mold resistance than samples only treated with a mold inhibitor. The thermogravimetric–Fourier-transform infrared spectroscopy analysis of the treated and the control samples indicated that the chemical structure of the surface was slightly modified, e.g., silicon was almost completely removed, which enhanced liquid permeability. The dilute ACQ-D solution combined with a proper pretreatment process could retain the favorable green color of bamboo and also improve mold resistance by slightly modifying the surface chemistry.
Combining Thermo-Hydro-Mechanical and Phenol-Resin Impregnation Treatments: Potential for High-Density Poplar Flooring
Authors: Schwarzkopf Matthew 
Published: August 2021

Abstract
Thermo-hydro-mechanical (THM) treatments can be used to improve certain properties of underutilized wood species, especially those with low densities. These treatments densify the wood by softening the cell walls using heat, pressure, and moisture but are subject to set-recovery (recovery of compressive deformation) when exposed to humidity. Phenol-based resins have been successful in mitigating this issue when impregnated into the wood. This work explores the use of a new phenol-based resin combined with a THM treatment to limit set-recovery and produce products with the potential for flooring applications. Scratch resistance, hardness, and glue-line shear strength were used to assess the performance. The THM treatment and impregnated phenol resin used in this study increased the scratch resistance, density, and hardness of natural poplar wood and created satisfactory bonding conditions for flooring purposes. With optimization of THM parameters and resin solids content, the resulting product could provide a high-quality flooring material used alone or as a thin laminate from a low-density species like poplar.
Physical and Mechanical Properties of Hard Maple (Acer saccharum) and Yellow Poplar (Liriodendron tulipifera)
Authors: Uzcategui Marly Gabriela Carmona , Seale Roy Daniel , França Frederico José Nistal 
Published: August 2021

Abstract
Maple and poplar are common names of species that grow in the eastern United States. Physical and mechanical properties were evaluated from small clear wood specimens of hard maple (Acer saccharum) and yellow poplar (Liriodendron tulipifera). Specific gravity, static bending strength and modulus of elasticity, compression parallel and perpendicular to grain, and Janka hardness were tested. The experiments were carried out on defect-free specimens extracted from boards supplied by members of the Staircase Manufacturers Association. The material was donated by companies located in the eastern United States. On the basis of the findings, it can be stated that mechanical properties for maple and yellow poplar have not changed substantially because the average values remain in a range that is very close to the values published in previous studies.
Moisture Transport in Wood-Based Structural Panels under Transient Hygroscopic Conditions
Authors: Way Daniel , Kamke Frederick A. , Sinha Arijit 
Published: August 2021

Abstract
Development of moisture gradients within wood and wood-based composites can result in irreversible moisture-induced damage. Accelerated weathering (AW), generally employing harsh environmental conditions, is a common tool for assessing moisture durability of wood composite products. Use of milder AW conditions, such as cyclic changes in relative humidity (RH), may be of interest to the wood-based composites industry in assessing moisture durability under more realistic conditions. The primary objective of this study was to determine whether moisture profile development in oriented strand board and plywood during cyclic RH changes could be reasonably predicted with a simple moisture transport model, which may be practical for wood-based composite industry members seeking to develop new AW protocols. The diffusion model based on Fick's second law with empirically determined moisture transport parameters fits the experimental data reasonably well for the purpose of screening RH parameters.
Comparative Study of the Hydrothermal Softening Characteristics of Heartwood and Sapwood
Authors: Li Zhu , Lu Jianxiong , Cao Jinzhen , Jiang Jiali 
Published: August 2021

Abstract
This study was conducted to investigate the hydrothermal softening characteristics of heartwood and sapwood from Catalpa bungei. The viscoelastic properties were investigated by dynamic mechanical analysis (DMA Q800) with a tension and submersion mode. Heartwood and sapwood specimens were tested under water-saturated conditions in the radial and tangential directions. The measured temperature ranged from 25°C to 79°C with three heating rates: 0.5°C/min, 1°C/min, and 2°C/min. The results show that heartwood specimens presented a higher storage modulus (E′) and a lower reduction of wood rigidity (ΔE′) than sapwood specimens. A difference was also observed in loss modulus (E″), and the glass transition temperature of lignin in heartwood specimens was nearly 2°C to 3°C lower than that in sapwood specimens. This could be caused by lower lignin content and higher levels of extractives of sapwood in comparison with heartwood. Additionally, a circular arc curve of E′ versus E″ was formed in heartwood specimens, irrespective of heating rate. These findings suggest that heartwood presented better hydrothermal softening characteristics than sapwood. Compared with the tangential specimens, the radial specimens revealed higher E′ and lower ΔE′, indicating that the radial specimens were less influenced by hydrothermal treatment.
The Use of South African Spent Pulping Liquor to Synthesize Lignin Phenol-Formaldehyde Resins
Authors: Govender Priyashnie , Majeke B. M. , Alawode Abiodun Oluseun , Gorgens Johans F. , Tyhoda Luvuyo 
Published: August 2021

Abstract
This study aims to investigate the potential of using lignin sourced from South African black liquor as a total phenol substitute in phenol-formaldehyde resins (PFRs), with a particular focus on bonding strength and curing properties. Four South African pulping-based lignins were used to synthesize these lignin-phenol formaldehyde resins (LPF100 resins), namely Eucalyptus Kraft lignin, Pine Kraft lignin, Bagasse Soda lignin, and Bagasse Steam Exploded lignin. Fourier-transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry were used to determine structural and curing properties. These resins were then used directly (unmodified) as adhesives to test shear bonding strength (R0 LPF100 adhesives). To improve the bonding properties of the unmodified LPF100 adhesives, the LPF100 resins were modified via the addition of a crosslinker (hexamine) as well as a hardener (either glyoxal, R1, or epichlorohydrin, R2). All R0 LPF100 adhesives fell below the GB/T 17657-2013 plywood standard of ≥0.7 MPa, with the Bagasse Soda LPF100 adhesive recording the highest bonding performance of 0.5 MPa, and the lowest curing temperature of 68°C. From the modified adhesives, the best performing were the Pine Kraft (R1) and the Eucalyptus Kraft (R2) LPF100 adhesives, recording 1.4 and 1.3 MPa, respectively. The curing temperatures of both these resins were 71°C and 80°C, respectively. Ultimately, the results of this study indicated that favorable adhesive properties may be obtained with the use of South African pulping-based lignins as a 100 percent phenol substitute in PFRs.