Wood and Fiber Science最新文献_第8页

Estimating lumber properties with acoustic-based technologies—Part 2: Ultimate tension stress estimation from time- and frequency-domain parameters 用声学技术估计木材性能-第2部分:从时域和频域参数估计极限拉应力

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-10-28 DOI: 10.22382/wfs-2020-037

C. A. Senalik, F. França, R. D. Seale, R. Ross, R. Shmulsky

{"title":"Estimating lumber properties with acoustic-based technologies—Part 2: Ultimate tension stress estimation from time- and frequency-domain parameters","authors":"C. A. Senalik, F. França, R. D. Seale, R. Ross, R. Shmulsky","doi":"10.22382/wfs-2020-037","DOIUrl":"https://doi.org/10.22382/wfs-2020-037","url":null,"abstract":"This research article summarizes results from Part 1 of a study designed to examine the use of advanced signal processing techniques with acoustic-based lumber assessment technologies to evaluate the MOE and ultimate tension stress (UTS) of structural lumber. In Part 1 of this research, a mathematical model of acoustic wave behavior in an idealized specimen is derived using fundamental mechanics. In Part 2, wave behavior is examined experimentally in a series of 38 × 38 × 2438-mm wood specimens. The specimens vary considerably in visual character. Several of the specimens are, from a visual assessment, clear of naturally occurring defects such as knots. Conversely, strength-reducing defects such as knots are visible in several specimens. The presence of naturally occurring defects can affect acoustic waves in a variety of ways. A few examples include altering wave speed, changing the wave travel path, and/or converting the wave from longitudinal waves to shear waves or back through mode conversion. These alterations can cause wave behavior to deviate from the behavior observed in clear wood specimens. Deviations are observable in both time and frequency domains. From the differences, parameters are identified which improve estimation of UTS.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"390-399"},"PeriodicalIF":1.4,"publicationDate":"2020-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48471702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Density profile and micromorphology variation of densified wood from three fast growth hardwood species in Costa Rica 哥斯达黎加三种速生硬木致密木材的密度剖面和微观形态变化

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-28 DOI: 10.22382/wfs-2020-025

C. Tenorio, R. Moya, Mario Tommasiello

{"title":"Density profile and micromorphology variation of densified wood from three fast growth hardwood species in Costa Rica","authors":"C. Tenorio, R. Moya, Mario Tommasiello","doi":"10.22382/wfs-2020-025","DOIUrl":"https://doi.org/10.22382/wfs-2020-025","url":null,"abstract":"This study evaluates 1) the effect of the thermo-hydro-mechanical densification process-using three temperatures, two compression times, and the presence or absence of steam, and 2) the effect of initial wood micromorphology on the density profile of densified wood of three low-density fast growing hardwood species in Costa Rica ( Alnus acuminate , Vochysia ferruginea , and Vochysia guatemalensis ). Four density profiles in the densified wood of the three species resulted from the densification temperature and the initial micromorphology of the wood. The initial diameter of the vessels affects the compression stage during the densification process and causes the formation of irregular density profiles. Therefore, this is the most important element in determining the type of the density profile. The wood of A. Acuminata (with smaller-diameter vessels) densified at 180 o C tends to produce more uniform density profiles than the other two species that have larger diameter vessels. The time of compression and the use or not of steam as an initial stage in the densification process did not influence the types of density profiles obtained. Similarly, the type of wood tissue and wood pattern had no effect on the type of density profiles. In conclusion, uniform and regular density profiles in densified wood are more likely to be achieve at high temperatures and with smaller-diameter vessels.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"266-279"},"PeriodicalIF":1.4,"publicationDate":"2020-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41964712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Oriented strand board with improved dimensional stability by extraction of hemicelluloses 通过提取半纤维素提高尺寸稳定性的定向刨花板

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-28 DOI: 10.22382/wfs-2020-024

Natalia Hornus, George Cheng, Iris Beatriz Vega Erramuspe, M. Peresin, T. Gallagher, B. Via

{"title":"Oriented strand board with improved dimensional stability by extraction of hemicelluloses","authors":"Natalia Hornus, George Cheng, Iris Beatriz Vega Erramuspe, M. Peresin, T. Gallagher, B. Via","doi":"10.22382/wfs-2020-024","DOIUrl":"https://doi.org/10.22382/wfs-2020-024","url":null,"abstract":"Oriented strand board (OSB) panels are commonly used for wooden building structures such as Walls, floors, ceilings, and furniture. These wood composites are manufactured with small wooden strands held together in specific orientations by adhesives. Other additives such as wax might be added to reduce water absorption. One of the limitations of the panels produced today is their poor performance under high humidity conditions. The goal of the present work was 1) to extract hemicelluloses from pine wood strands before the fabrication of OSB panels and 2) to test the impact of the pretreatment on the dimensional stability of these panels. For that purpose, pressure-assisted hydrothermal processes at three different temperatures (120, 140, and 160 o C) were performed for 45 min of extraction time in each case. Hemicelluloses in treated wood strands were quantified using high-performance liquid chromatography. Water absorption, thickness swell, MOE, MOR, and internal bond strength were measured to assess the influence of the pretreatment on OBS properties. According to the results, a hydrothermal pretreatment is beneficial for the performance of OSB panels at high humidity levels. The pretreatment of pine strands at 160 o C allowed for the maximum removal of hemicelluloses, without a significant degradation of cellulose or lignin, and the OSB panels pretreated with these pinewood strands displayed the best performance in dimensional stability under wet conditions.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"257-265"},"PeriodicalIF":1.4,"publicationDate":"2020-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43507371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Use of longitudinal vibration and visual characteristics to predict mechanical properties of No. S Southern pine 2x8 and 2x10 Lumber 利用纵向振动和视觉特性预测南方松2×8和2×10材的力学性能

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-28 DOI: 10.22382/wfs-2020-026

F. França, T. França, R. D. Seale, R. Shmulsky

引用次数: 2

Physical and mechanical behaviors of thermally modified rubberwood glulam beam under sustained cyclic loading 热改性胶木胶合木梁在持续循环荷载作用下的物理力学行为

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-28 DOI: 10.22382/wfs-2020-028

T. Pulngern, T. Udtaranakron, K. Chanto

{"title":"Physical and mechanical behaviors of thermally modified rubberwood glulam beam under sustained cyclic loading","authors":"T. Pulngern, T. Udtaranakron, K. Chanto","doi":"10.22382/wfs-2020-028","DOIUrl":"https://doi.org/10.22382/wfs-2020-028","url":null,"abstract":"This study evaluated the effect of thermal modification on the physical and mechanical properties of rubberwood glued laminated (glulam) timber. The flexural creep property and cyclic loading behavior were also investigated. The obtained results indicated that the MC and specific gravity of thermally modified rubberwood decreased with an increase in modification temperature. Moreover, the flexural strength of the rubberwood glulam timber at modification temperatures of 180 and 220 o C was 8.57% and 46.72%, respectively, which was less than that of the control rubberwood dried at 90 o C. However, the MOE between the thermally modified rubberwood glulam timber and control specimens was not significantly changed. The flexural creep test indicated that the maximum relative creep of the thermally modified rubberwood timber equaled 0.31, which was lower than that of other natural timber and tended to decrease when increasing the stress level. Various mathematical models were also proposed, and the best-fitted model was found to be the Bailey-Norton power law model. Nevertheless, the cyclic loading results also proved that thermal modification temperature had a direct effect on the ductility index and energy dissipation of rubberwood glulam timber, but it had no significant effect on the impairment of strength.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"298-312"},"PeriodicalIF":1.4,"publicationDate":"2020-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47226679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploration of membrane-based dehumidification system to improve the energy efficiency of kiln drying processes: Part 1 – Factors that affect moisture removal efficiency 膜基除湿系统提高窑干过程能源效率的探索:第一部分-影响除湿效率的因素

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-27 DOI: 10.22382/wfs-2020-029

Nasim Alikhani, Ling Li, Jinwu Wang, D. Dewar, M. Tajvidi

{"title":"Exploration of membrane-based dehumidification system to improve the energy efficiency of kiln drying processes: Part 1 – Factors that affect moisture removal efficiency","authors":"Nasim Alikhani, Ling Li, Jinwu Wang, D. Dewar, M. Tajvidi","doi":"10.22382/wfs-2020-029","DOIUrl":"https://doi.org/10.22382/wfs-2020-029","url":null,"abstract":"Green wood drying through a steam kiln-drying technology is an energy-demanding process. This process consumes a large amount of energy to evaporate water from wood and discharge it to the atmosphere through venting. The thermal energy loss from the venting of dry kilns takes up to 20% of total energy consumed by the whole wood-drying operation because a considerably large amount of thermal energy is stored in the exhaust air. Harvesting and reusing such waster thermal energy wood improve the energy efficiency of kiln-drying process. Advanced moisture-selective membranes have been used to dehydrate humid air or gas steam because of the advantages of low energy requirements, simplicity of operation, and high specificity. However, the application of the membrane in wood-drying processes has not been addressed. Therefore, this study aimed to investigate the feasibility of using a moisture-selective membrane system to dehydrate the warm moist exhaust air to achieve an energy-saving purpose. The membrane material was polydimethylsiloxane (PDMS) with high water vapor permeability. A small membrane-based dehumidification system was constructed to evaluate the effects of four factors (temperature, airflow rate, initial RH, and vacuum pressure) on the efficiency of moisture vapor removal. Statistical analysis in terms of response surface methodology was carried out. The major findings include 1) an increase in the temperature and vacuum pressure caused a significant increase in the efficiency of moisture vapor removal, 2) the initial RH had little influence on the efficiency of moisture vapor removal, 3) increasing the airflow rate had a negative impact on the efficiency of moisture vapor removal, and 4) the regression model can be used to predict the efficiency of moisture vapor removal. This PDMS membrane would be a possible solution for a pre-drying process at relatively low operation temperatures (<45 o C), that is dehumidification process.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"313-325"},"PeriodicalIF":1.4,"publicationDate":"2020-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43567647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

EDITORIAL: A farewell from an old wood scientist and technologist 社论:一位老木材科学家和技术专家的告别

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-27 DOI: 10.22382/wfs-2020-023

M. Schneider

引用次数: 0

Decay of birdseye sugar maple (Acer Saccharum) and curly red maple (Acer Rubrum) 鸟眼糖枫(Acer Saccharum)和卷曲红枫(Acer Rubrum)的腐烂

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-27 DOI: 10.22382/wfs-2020-027

T. Bal, K. E. Schneider, D. Richter

{"title":"Decay of birdseye sugar maple (Acer Saccharum) and curly red maple (Acer Rubrum)","authors":"T. Bal, K. E. Schneider, D. Richter","doi":"10.22382/wfs-2020-027","DOIUrl":"https://doi.org/10.22382/wfs-2020-027","url":null,"abstract":"Two figured woods, commonly known as birdseye maple ( Acer saccharum , sugar maple) and curly maple ( Acer rubrum , red maple), were exposed to brown rot and white rot fungi in a standard laboratory decay test and compared with unfigured wood of each species, respectively. For the birdseye maple, two levels of figure intensity were used: wood with heavy figure and wood with light figure. Heavily figured birdseye maple wood was decayed significantly less by the brown rot fungus Rhodonia placenta than unfigured maple wood or lightly figured maple wood. However, heavily figured birdseye maple wood was decayed significantly more by two white rot fungi, Trametes versicolor and Irpex lacteus , than unfigured maple wood but was not decayed significantly more than lightly figured wood. For both brown rot and white rot fungi, lightly figured birdseye maple wood did not decay significantly differently compared with unfigured wood. Likewise, there was no significant difference in decay between curly red maple wood and unfigured red maple wood for either brown rot or white rot fungi. Results suggest chemical or anatomical differences in the heavily figured birdseye sugar maple wood affect decay by brown rot and white rot fungi. These findings may be useful to hobbyists and woodworkers needing to protect wood or who partially decay wood to produce spalted wood for decorative purposes.","PeriodicalId":23620,"journal":{"name":"Wood and Fiber Science","volume":"52 1","pages":"292-297"},"PeriodicalIF":1.4,"publicationDate":"2020-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45519756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PROFESSIONAL PAGES: The Wood Products Processing Program at the University of British Columbia – Reflections on the Last Twenty-Five Years 专业页:木材产品加工程序在不列颠哥伦比亚大学-反思过去的二十五年

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-27 DOI: 10.22382/wfs-2020-031

S. Ellis

引用次数: 0

TECHNICAL NOTE: Effects of Long-term Outdoor Exposure on Properties of I-joists 技术说明:长期暴露在室外对工字托梁性能的影响

IF 1.4 4区工程技术

Wood and Fiber Science Pub Date : 2020-07-27 DOI: 10.22382/wfs-2020-030

D. Way, J. Morrell, Arijit Sinha

引用次数: 2