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Article
Publication date: 14 September 2011

Shahril Bahari and Wan Raihan Wan Jaafar

The bamboo strips and oil palm trunk veneers were laid-up together alternately using phenol formaldehyde (PF) adhesive to form composite lumber with two different types of…

Abstract

The bamboo strips and oil palm trunk veneers were laid-up together alternately using phenol formaldehyde (PF) adhesive to form composite lumber with two different types of layer orientation. The composite lumber was hot pressed at two different pressing times. Physical properties test, such as cold water and hot water delamination, as well as mechanical properties test, such as flexural and compression were conducted according to a specific standard. Results showed that longer pressing time has increased all properties, except flexural and compression. Cross orientation has increased the bonding strength behaviour between bamboo strips and oil palm trunk veneers, thus influenced the low delamination percentage and good modulus of elasticity value. It is observed that the different failure behaviour was influenced by different types of layer orientation, especially in compression and physical properties. Different pressing times had not influenced any difference of failure modes.

Details

World Journal of Engineering, vol. 8 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

Article
Publication date: 13 November 2007

W.H. Wang, Q.W. Wang, H. Xiao and J.J. Morrell

To investigate the effects of moisture and freeze‐thaw cycling on the absorption and flexural properties of rice‐hull‐polyethylene (PE) composite.

Abstract

Purpose

To investigate the effects of moisture and freeze‐thaw cycling on the absorption and flexural properties of rice‐hull‐polyethylene (PE) composite.

Design/methodology/approach

Various rice‐hull‐PE composite specimens were submerged in water at various temperatures and subjected to various freeze‐thaw cycles. Various characterisations including water absorption, bending strength and stiffness, Fourier transform infrared spectroscopy and scanning electron microscope imaging were performed.

Findings

High temperatures accelerated the water sorption of the rice‐hull‐PE composite and increased the equilibrium moisture content. The uncoated surface was not significantly more easily permeated than the coated surface, contrary to expectations. However, more water was absorbed from the cut surface than from the original extruded surface. This was attributed to the tiny checks left on the surface by the sawing action, which indicated the importance of protecting the original surface layer from scraping or other damage. Bending strength and stiffness of the rice‐hull‐PE composite decreased significantly after the freeze‐thaw cycling treatment. The modulus of elasticity decreased more than the modulus of rupture. Compared to the effect of water immersion alone, freeze‐thaw cycling treatment slightly accelerated this decrease.

Research limitations/implications

The results of this study were obtained from accelerated laboratory experiments. Further research could be carried out to evaluate the properties of this rice‐hull‐PE composite in practical application.

Practical implications

The research revealed a possible degradation in quality when the rice‐hull‐PE composite is used in moist or freezing conditions. The resin layer on the extruded surface provides an important protection.

Originality/value

In China, rice‐hull powder is widely used as a reinforcing component in plastic composite. However, the durability of rice‐hull/PE composites has rarely been investigated. Results from this study will help users apply rice‐hull‐PE composites correctly and encourage the development of other agro‐fibre/polymer materials.

Details

Pigment & Resin Technology, vol. 36 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 21 June 2021

Shashi K. Shahi, Mohamed Dia, Peizhi Yan and Salimur Choudhury

The measurement capabilities of the data envelopment analysis (DEA) models are used to train the artificial neural network (ANN) models for the best performance modeling…

Abstract

Purpose

The measurement capabilities of the data envelopment analysis (DEA) models are used to train the artificial neural network (ANN) models for the best performance modeling of the sawmills in Ontario. The bootstrap DEA models measure robust technical efficiency scores and have benchmarking abilities, whereas the ANN models use abstract learning from a limited set of information and provide the predictive power.

Design/methodology/approach

The complementary modeling approaches of the DEA and the ANN provide an adaptive decision support tool for each sawmill.

Findings

The trained ANN models demonstrate promising results in predicting the relative efficiency scores and the optimal combination of the inputs and the outputs for three categories (large, medium and small) of sawmills in Ontario. The average absolute error in predicting the relative efficiency scores varies from 0.01 to 0.04, and the predicted optimal combination of the inputs (roundwood and employees) and the output (lumber) demonstrate that a large percentage of the sawmills shows less than 10% error in the prediction results.

Originality/value

The purpose of this study is to develop an integrated DEA-ANN model that can help in the continuous improvement and performance evaluations of the forest industry working under uncertain business environment.

Article
Publication date: 1 March 1997

Robert W. Messler

An ongoing revolution in the development and implementation of new materials has placed new demands on the ability to join these materials into devices, parts and…

841

Abstract

An ongoing revolution in the development and implementation of new materials has placed new demands on the ability to join these materials into devices, parts and components, and devices, parts and components into packages, assemblies and structures for both electrical and mechanical applications. Looks at the past successes and shortcomings of traditional joining technologies. Presents some obvious and some not‐so‐obvious directions as one attempt at prognostication of the needs for new joining technologies for the forthcoming new century.

Details

Assembly Automation, vol. 17 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

Content available
Article
Publication date: 1 September 2004

84

Abstract

Details

Structural Survey, vol. 22 no. 4
Type: Research Article
ISSN: 0263-080X

Article
Publication date: 20 January 2022

Milad Shabanian and Nicole Leo Braxtan

The purpose of this paper is to investigate the thermo-mechanical behavior of intermediate-size glued-laminated beam-to-girder assemblies connected with T-shaped…

Abstract

Purpose

The purpose of this paper is to investigate the thermo-mechanical behavior of intermediate-size glued-laminated beam-to-girder assemblies connected with T-shaped slotted-in steel doweled connections at ambient temperature (AT), after and during non-standard fire exposure.

Design/methodology/approach

AT tests were performed using a universal testing machine (UTM) to evaluate the load-carrying capacity and failure modes of the assembly at room temperature. Post-fire-performance (PFP) tests were conducted to study the impact of 30-min and 60-min partial exposure to a non-standard fire on the residual strength of the assemblies. The assemblies were subject to fire in a custom-designed frame, then cooled and loaded to failure in the UTM. A fire-performance test was conducted to investigate the fire-resistance during non-standard fire exposure by simultaneously applying fire and mechanical load with the custom frame.

Findings

At AT, embedment failure of the dowels followed by brittle splitting failure were found to be the dominant failure modes in the beams. In the PFP tests, embedment failure and plastic bending of the dowels were the only observed failure modes. The residual strength of the assembly was reduced by 23.7% after 30-min and 47.8% after 60-min of fire exposure. Ductile embedment failure of the timber in contact with the dowels was the only failure mode observed during the fire-performance test, with the maximum rate of displacement at 57 min into the fire.

Originality/value

Data are presented for full-contact (no gap) connections in Glulam assemblies. PFP results are first to be published.

Article
Publication date: 24 May 2011

N.A. Abdelwahab and M.A. Nassar

The purpose of this paper is to examine the preparation of adhesive by incorporation of kraft lignin as an agricultural waste into phenol formaldehyde (PF) resin structure…

Abstract

Purpose

The purpose of this paper is to examine the preparation of adhesive by incorporation of kraft lignin as an agricultural waste into phenol formaldehyde (PF) resin structure and to evaluate the mechanical properties of lignin phenol formaldehyde (LPF) as wood adhesive.

Design/methodology/approach

PF resin (resole) was prepared using sodium hydroxide as a catalyst. Different concentrations of lignin were incorporated into PF resin structure. The effect of lignin concentration, formaldehyde to phenol molar ratio, catalyst concentration, temperature and time upon solid content, adhesive strength and gel time was studied. The kraft lignin, PF and LPF resins were characterised using FT‐IR and thermal analysis.

Findings

The incorporation of lignin into PF resin (resole) increases adhesive strength and decreases gel time. The highest adhesive strength and the lowest gel time were achieved at 90 per cent of kraft lignin, formaldehyde to phenol molar ratio, 7.2 and 10 per cent of catalyst, after 4 h and at 80°C.

Research limitations/implications

The effect of different concentrations of kraft lignin, formaldehyde/phenol molar ratio, catalyst concentration, temperatures and time upon solid content, gel time and adhesive strength was studied.

Practical implications

Incorporation of kraft lignin into resole leads to adhesive with improved mechanical properties.

Originality/value

It was found that LPF resin is better than PF resin from the economical point of view and has the better mechanical properties.

Details

Pigment & Resin Technology, vol. 40 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 25 May 2010

June Mitsuhashi and J.J. Morrell

Wetting wood plastic composites (WPCs) prior to testing can be challenging because of the inherent water repellency of the plastic. The purpose of this paper is to explore…

311

Abstract

Purpose

Wetting wood plastic composites (WPCs) prior to testing can be challenging because of the inherent water repellency of the plastic. The purpose of this paper is to explore the use of heating and wetting to accelerate moisture uptake on two WPCs.

Design/methodology/approach

Full size samples of the two WPCs were immersed in water at various temperatures or heated in an autoclave. Samples were removed periodically and dissected to determine the moisture profile by oven drying and weighing.

Findings

Moisture uptake is accelerated by heating, but the effect is mainly confined to the outer 5 mm of the samples. Moisture levels deeper in the samples are largely unaffected.

Research limitations/implications

Moisture uptake can be enhanced by heating, but the inability to increase moisture levels deeper in the wood suggests that tests assessing the role of moisture on WPC properties should use thinner specimens to ensure that moisture is well distributed in the materials.

Practical implications

The results suggest the need for a re‐evaluation of test methodologies for WPCs where moisture uptake is an integral part of the procedures to more closely align the methods to the WPC/moisture behaviour.

Originality/value

This paper will help researchers develop better methods for assessing the role of moisture in WPC behaviour.

Details

Pigment & Resin Technology, vol. 39 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

Book part
Publication date: 30 June 2004

Harry Nelson and Ilan Vertinsky

Disputes about Canadian exports of softwood lumber to the U.S. have persisted for more than a century. In this paper the roots of the disputes and the prospects for their…

Abstract

Disputes about Canadian exports of softwood lumber to the U.S. have persisted for more than a century. In this paper the roots of the disputes and the prospects for their resolution are examined. The focus is on the following key factors: (1) the nature of supply and demand; (2) the normative differences underlying the systems of timber management in the two countries and differences about what constitutes a “level playing field”; (3) rent seeking by stakeholders; and (4) weakness in bilateral and multilateral trade dispute resolution institutions. The paper concludes that there are good reasons to expect short term solution to the current dispute but persistence of the disputes in the long run.

Details

North American Economic and Financial Integration
Type: Book
ISBN: 978-0-76231-094-4

Article
Publication date: 1 September 2006

Amr A.G. Hassanein and Bahaee N.L. Khalil

The aim of this article is to develop a cost index to serve as a price indicator for the Egyptian construction industry.

1415

Abstract

Purpose

The aim of this article is to develop a cost index to serve as a price indicator for the Egyptian construction industry.

Design/methodology/approach

The model (Egypt 1 indices) developed for building the indices in this paper has been derived based on the “Engineering News Record” (ENR) indices model with modifications to better suit the Egyptian market. Egypt 1 indices are comprised of three indices, which serve as a general construction price indicator for the construction industry price movement in Egypt. The period analyzed in this research is 11 years (1988 through 1998).

Findings

Validation of Egypt 1 indices numbers produced in this paper showed that each index does indeed represent the respective type of building for which it was computed. Further, the analysis of Egypt 1 indices compared to the ENR indices revealed that both indices exhibited trends that are generally similar from the year 1992 up to 1998 (the last year included in this study).

Originality/value

This research has the potential to introduce the use of construction cost indices and to put these into practice. This should help aid contractors and other construction parties operating in Egypt with an adequate tool for pricing and estimation of projects.

Details

Engineering, Construction and Architectural Management, vol. 13 no. 5
Type: Research Article
ISSN: 0969-9988

Keywords

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