Modification factors of the embedding strength dependent on the temperature and load-to-grain angle for two wood species planted in Brazil

Author(s):  
Eduardo Schneid ◽  
Poliana Dias de Moraes
Keyword(s):  
Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Yanjie Li ◽  
Wenjian Liu ◽  
Ruishu Cao ◽  
Zifeng Tan ◽  
Jun Liu ◽  
...  

Abstract Background Wood basic density (WBD) is one of the most crucial wood property in tree and mainly determined the end use of wood for industry. However, the measurement WBD is time- and cost-consuming, which an alternatively fast and no-destructive measurement is needed. In this study, capability of NIR spectroscopy combined with partial least squares regression (PLSR) to quantify the WBD were examined in multiple wood species. To obtain more accurate and robust prediction models, the grain angle (0° (transverse surface), 45°, 90° (radial surface)) influence on the collection of solid wood spectra and a comparison of found variable selection methods for NIR spectral variables optimization were conducted, including significant Multivariate Correlation (sMC), Regularized elimination procedure (Rep), Iterative predictor weighting (Ipw) and Genetic algorithm (Ga). Models made by random calibration data selection were conducted 200 times performance evaluation. Results These results indicate that 90° angle models display relatively highest efficiency than other angle models, mixed angle model yield a satisfied WBD prediction results as well and could reduce the influence of grain angle. Rep method shows a higher efficiency than other methods which could eliminate the uninformative variables and enhance the predictive performance of 90° angle and mix angle models. Conclusions This study is potentially shown that the WBD (g/cm3) on solid wood across grain angles and varies wood species could be measured in a rapid and efficient way using NIR technology. Combined with the PLSR model, our methodology could serve as a tool for wood properties breeding and silviculture study.


2020 ◽  
Vol 9 (4) ◽  
pp. e31942727
Author(s):  
João Gabriel Missia da Silva ◽  
Pedro Nicó de Medeiros ◽  
Denise Ransolin Soranso ◽  
Vinicius Peixoto Tinti ◽  
José Tarcísio da Silva Oliveira ◽  
...  

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.


Author(s):  
Nurida Finahari

The art of chisel mask is developed in Tumpang Malang area as part of dance costume fairs, puppet show andcultural ritual, although in its development, this mask sculpture is also sold and become a tourism commodity. The potentialsales of mask sculptures is increasing, especially because of the demanders are foreign tourists, cultural enthusiasts andcomponent of tourism activities. That is, Topeng Malangan has the potential to be developed as an export commodity. Thesales system is still limited to cultural events or when there is a visit of education and tourism to the arts-padepokan. Thisprompted some people around the padepokan to start a home industry to meet the availability of the mask. In general, theproblems encountered by the craftsmen are (1) availability of raw materials, especially for suitable wood species, (2)production equipment, especially for pre-carving process and preservation of product, (3) there is no standard marketingscheme, (4) does not have a business management system, and (5) highly skilled craftsmen are still very limited. The solutionsoffered are divided into three stages: (1) technological strengthening, including strengthening production process technologyand increasing the number of craftsmen; (2) establishing business management; and (3) establishing trademarks, copyrightsand product marketing expansions


2020 ◽  
Vol 52 (1) ◽  
pp. 28-43 ◽  
Author(s):  
Wei Xu ◽  
Xiaoyang Fang ◽  
Jiatong Han ◽  
Zhihui Wu ◽  
Jilei Zhang

2020 ◽  
Vol 11 (1) ◽  
pp. 44
Author(s):  
Sergej Medved ◽  
Daša Krapež Tomec ◽  
Angela Balzano ◽  
Maks Merela

Since invasive alien species are one of the main causes of biodiversity loss in the region and thus of changes in ecosystem services, it is important to find the best possible solution for their removal from nature and the best practice for their usability. The aim of the study was to investigate their properties as components of wood-plastic composites and to investigate the properties of the wood-plastic composites produced. The overall objective was to test the potential of available alien plant species as raw material for the manufacture of products. This would contribute to sustainability and give them a better chance of ending their life cycle. One of the possible solutions on a large scale is to use alien wood species for the production of wood plastic composites (WPC). Five invasive alien hardwood species have been used in combination with polyethylene powder (PE) and maleic anhydride grafted polyethylene (MAPE) to produce various flat pressed WPC boards. Microstructural analyses (confocal laser scanning microscopy and scanning electron microscopy) and mechanical tests (flexural strength, tensile strength) were performed. Furthermore, measurements of density, thickness swelling, water absorption and dimensional stability during heating and cooling were carried out. Comparisons were made between the properties of six WPC boards (five alien wood species and mixed boards). The results showed that the differences between different invasive alien wood species were less obvious in mechanical properties, while the differences in sorption properties and dimensional stability were more significant. The analyses of the WPC structure showed a good penetration of the polymer into the lumens of the wood cells and a fine internal structure without voids. These are crucial conditions to obtain a good, mechanically strong and water-resistant material.


Author(s):  
Joielan Xipaia dos Santos ◽  
Helena Cristina Vieira ◽  
Tawani Lorena Naide ◽  
Deivison Venicio Souza ◽  
Graciela Inés Bolzon de Muñiz ◽  
...  

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 524
Author(s):  
Junhua Xu ◽  
Shuangbao Zhang ◽  
Guofang Wu ◽  
Yingchun Gong ◽  
Haiqing Ren

With the increasing popularity of cross-laminated timber (CLT) constructions around the world, there have been attempts to produce CLT using local wood species in different countries, such as Japanese larch (Larix kaempferi (Lamb.) Carr.) in China. Thus, the need to investigate the connection performance also increases to support the design and construction of CLT buildings using local wood species. In this study, the withdrawal properties of three different types of self-tapping screws (STS), with a diameter of 6 mm, 8 mm, and 11 mm, were tested with Japanese larch CLT. The results revealed that the withdrawal strength of STS increased with increasing density and effective length, but decreased with an increasing diameter. With a density increment of 0.05 g/cm3, the withdrawal strength increased by an average of 9.4%. With an effective length increment of 24 mm, the withdrawal strength increased by an average of 1.4%. An empirical regression model was adopted to predict the withdrawal strength of Japanese larch CLT based on the results, which can be used for potential engineering design of CLT connections using STS.


Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Liselotte De Ligne ◽  
Jan Van den Bulcke ◽  
Jan M. Baetens ◽  
Bernard De Baets ◽  
Gang Wang ◽  
...  

AbstractThe effect of fungicidal components in wood has been known for ages, yet there is no method to assess the impact of such components on the durability of a wood species, as compared to other material characteristics that influence decay. In this paper, the importance of fungicidal effects on the natural durability of 10 wood species is assessed in relation to other decay-influencing factors with a new test, the so-called ‘paste test’. By comparing results from this test with the ‘mini-block test’, on both heartwood and leached sapwood, insight is gained into the significance of fungicidal components on the one hand and other material characteristics on the other hand. The durability of species such as Prunus avium was attributed mainly to fungicidal components. For species such as Pterocarpus soyauxii, durability seemed to be an effect of both fungicidal components and moisture-regulating components, while the latter seemed to be of main importance in regulating the decay of Aucoumea klaineana and Entandrophragma cylindricum. Wood-anatomical features, such as the parenchyma content (in case of brown rot fungi) and the vessel-fiber ratio, possibly affect degradation as well. This work shows that fungicidal components are not always of major importance for the durability of a wood species. The authors hereby emphasize the importance of moisture-regulating components and wood anatomy on the durability of wood.


Author(s):  
Julia Naves Teixeira ◽  
Anderson Renato Vobornik Wolenski ◽  
Vinicius Borges de Moura Aquino ◽  
Tulio Hallak Panzera ◽  
Diogo Aparecido Lopes Silva ◽  
...  

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