Non-destructive evaluation of beech and oak wood bent at different radii

Published Date
May 2013, Vol.48:106–110, doi:10.1016/j.compositesb.2012.12.006

Author 

• Ümit Büyüksarı ^a,,,
 
• Nusret As ^b

• aDepartment of Wood Mechanics and Technology, Faculty of Forestry, Duzce University, Duzce, Turkey
• bDepartment of Wood Mechanics and Technology, Faculty of Forestry, Istanbul University, Istanbul, Turkey

Received 26 June 2012. Revised 15 September 2012. Accepted 13 December 2012. Available online 27 December 2012.

Abstract

The aim of this study was to investigate the parallel and perpendicular velocity and transmission time of beech and oak wood bent at different radii. Two trees from each wood species, having straight trunks of approximately 40 cm in diameter, were selected, and two 4-m logs were cut from each tree. The prepared samples, except those from the control groups, were steamed, bent and set. The samples were bent at three different radii (300 mm, 200 mm and 100 mm) in the tangential direction. The density, parallel and perpendicular (radial and tangential) velocity and transmission times of the beech and oak wood were determined. The results of this study showed that the bent samples of beech and oak wood had higher density compared to the unbent groups. The density of both wood species increased with the decreasing bending radius. The highest velocity parallel to the fibers was measured on the convex surface, while the lowest was measured on the concave surface. The parallel and perpendicular velocity decreased as the bending radius decreased.

Keywords

A. Wood

B. Mechanical properties 

D. Non-destructive testing

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• ⁎ 
  Corresponding author. Tel.: +90 380 542 1137; fax: +90 380 542 1136.
  
  

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Non-destructive testing of wood and wood-based materials

Published Date
September 2012, Vol.13(3):S26–S34, doi:10.1016/j.culher.2012.04.001
Wood Science for Conservation

Author 

Peter Niemz ^a,

David Mannes ^b,,

aETH Zurich, Institute for Building Materials (Wood Physics), Schafmattstrasse 6, CH-8093 Zurich, Switzerland

bPaul Scherrer Institute, CH-5232 Villigen PSI, Switzerland

Received 29 March 2012. Accepted 4 April 2012. Available online 7 May 2012. 

Abstract

Methods of non-destructive wood testing continue to gain importance. Online tools, for example to control production, have effectually been in use for years. Based on a measuring systematics (physically active principle and important influencing factors), a summary of methods to assess cultural heritage objects is given. To adopt methods based on physical effects, profound knowledge of wood physics is essential, particularly knowledge of interdependencies.

Keywords

Wood

Non-destructive testing

Cultural heritage

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• ⁎ 
  Corresponding author.
  
  

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Thermal conductivity of sorghum and sorghum–thermoplastic composite panels

Published Date
February 2013, Vol.45:455–460, doi:10.1016/j.indcrop.2013.01.011

Author 

• Chusheng Qi ^a,b
• Vikram Yadama ^b,,
• Kangquan Guo ^a
• Michael P. Wolcott ^b

• aCollege of Mechanical and Electronic Engineering, Northwest A&F University, Yanlgling 712100, China
• bComposite Materials and Engineering Center, Washington State University, Pullman 99163, WA, USA

Received 5 October 2012. Revised 25 December 2012. Accepted 4 January 2013. Available online 30 January 2013. 

Abstract

Thermal conductivity of a material is a key parameter to simulate heat transfer during manufacturing of a composite under heat and pressure. This study investigated the thermal conductivity of composite panels hot-pressed with varying proportions of sweet sorghum and high-density polyethylene (HDPE). Thermal conductivity of the composites was tested under steady-state conditions. The effects of temperature (12.5–62.5 °C), density (0.7–1.0 g/cm³) and HDPE (0–40%) content on thermal conductivity of the composite products were investigated. Thermal conductivity increases in a linear manner with temperature and density, and in a nonlinear manner with HDPE content. An empirical equation for describing the thermal conductivity of sweet sorghum and HDPE composite panels was fitted, and has a good agreement with testing data. Compared with other empirical equations for predicting the thermal conductivity of wood, the experimental values in this study consistently had lower values, indicting a significant difference in thermal conductivity of composites manufactured with agro-based natural fibers compared to wood fibers. Additionally, predicted thermal conductivity values are limited by those estimated by the parallel and series models for two phase composites.

Graphical abstract

Highlights

► Sweet sorghum–HDPE composites were fabricated and evaluated for thermal conductivity. ► Thermal conductivity of the tested composites linearly increases with temperature and density. ► Thermal conductivity of the tested composites nonlinearly increases with HDPE content. ► Empirical equation predicting thermal conductivity is presented and compared.

Keywords

• Thermal conductivity
• Natural fiber composites
• Sorghum
• High-density polyethylene
• Hot pressing

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• ⁎ 
  Corresponding author at: Washington State University, Composite Materials and Engineering Center, Pullman, WA, 99164-1806, USA. Tel.: +1 509 335 6261.

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Effects of innovation on the European wood industry market structure

Published Date
March 2014, Vol.40:40–47, doi:10.1016/j.forpol.2013.12.001

Author 

Oscar Alfranca ^a,,

Roberto Voces ^b

A. Casimiro Herruzo ^b

Luis Diaz-Balteiro ^b

aDepartment of Agri-Food Engineering and Biotechnology, Technical University of Catalonia, ESAB, Av. Canal Olímpic, s/n, 08860 Castelldefels, Spain

bDepartment of Forestry Economics and Management, Technical University of Madrid, Spain

Received 7 June 2013. Revised 16 December 2013. Accepted 16 December 2013. Available online 20 January 2014. 

Highlights

• Relationship between innovation and the European wood industry was analysed.
• •
  Wood industry market structure was explained using business and innovation variables.
• •
  R&D spending and personnel are key factors that explain market concentration.

Abstract

This study primarily aimed to contrast the potential relationships between innovation and market concentration. Thus, the relationship between innovation and the European wood industry market structure was analysed. An empirical model was assessed through panel techniques, wherein the wood industry market structure was explained through business-related variables and additional variables associated with generating innovation. The primary conclusion of this study with respect to the European wood industry is that R&D spending and R&D personnel are key factors in explaining market concentration. However, the influence of these variables may be affected by the initial degree of market concentration in the industry.

Keywords

Innovation

Market concentration

Research and development

Wood industry

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• ⁎ 
  Corresponding author. Tel.: + 34 9355 21227.

For further details log on website :
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