Mechanical Properties of Laminated Veneer Lumber (LVL) Fabricated from Three Malaysian Hardwood Species

The application of laminated veneer lumber (LVL) has long been limited to non-structural elements in Malaysia. The LVL is commonly fabricated with veneer from low to medium density (290 to 630 kg/m3) softwood or temperate hardwood. The data on the properties of LVL made from medium to high density (567 to 687 kg/m3) tropical hardwood species is very limited. Therefore, this study investigated the mechanical and bonding properties of LVL fabricated from Malaysian hardwood species namely Kasai (Pometia spp.), Mengkulang (Heritiera spp.) and Kedondong (Canarium spp.). Different variables were studied: i) wood species; ii) loading surface (flatwise or edgewise), iii) grain direction (parallel and perpendicular), iv) treatment condition. The bending and compression test was carried out in accordance with EN 408:2012, while the block shear test was conducted based on EN14374:2004 and EN 314-1:2004. The results shows that the grain direction has the most significant effect (P ≤ 0.01) on the bending, compressive and bonding properties of the samples tested. The treatment conditions for block shear test also displayed significant effect on its shear strength. The samples loaded parallelly displayed bending values 320-450% higher than the samples loaded at perpendicularly. The compressive strength and compressive modulus are 323-365% and 523-2530% respectively when loaded parallelly. LVL performed better mechanically when loaded parallelly and when subjected to less extreme treatment conditions

Mechanical Properties of Laminated Veneer Lumber (LVL) Fabricated from Three Malaysian Hardwood Species

The application of laminated veneer lumber (LVL) has long been limited to non-structural elements in Malaysia. The LVL is commonly fabricated with veneer from low to medium density (290 to 630 kg/m3) softwood or temperate hardwood. The data on the properties of LVL made from medium to high density (567 to 687 kg/m3) tropical hardwood species is very limited. Therefore, this study investigated the mechanical and bonding properties of LVL fabricated from Malaysian hardwood species namely Kasai (Pometia spp.), Mengkulang (Heritiera spp.) and Kedondong (Canarium spp.). Different variables were studied: i) wood species; ii) loading surface (flatwise or edgewise), iii) grain direction (parallel and perpendicular), iv) treatment condition. The bending and compression test was carried out in accordance with EN 408:2012, while the block shear test was conducted based on EN14374:2004 and EN 314-1:2004. The results shows that the grain direction has the most significant effect (P ≤ 0.01) on the bending, compressive and bonding properties of the samples tested. The treatment conditions for block shear test also displayed significant effect on its shear strength. The samples loaded parallelly displayed bending values 320-450% higher than the samples loaded at perpendicularly. The compressive strength and compressive modulus are 323-365% and 523-2530% respectively when loaded parallelly. LVL performed better mechanically when loaded parallelly and when subjected to less extreme treatment conditions

The Regulation of Skeletal Muscle Protein Turnover during the Progression of Cancer Cachexia in the ApcMin/+ Mouse

Muscle wasting that occurs with cancer cachexia is caused by an imbalance in the rates of muscle protein synthesis and degradation. The ApcMin/+ mouse is a model of colorectal cancer that develops cachexia that is dependent on circulating IL-6. However, the IL-6 regulation of muscle protein turnover during the initiation and progression of cachexia in the ApcMin/+ mouse is not known. Cachexia progression was studied in ApcMin/+ mice that were either weight stable (WS) or had initial (≤5%), intermediate (6–19%), or extreme (≥20%) body weight loss. The initiation of cachexia reduced %MPS 19% and a further ∼50% with additional weight loss. Muscle IGF-1 mRNA expression and mTOR targets were suppressed with the progression of body weight loss, while muscle AMPK phosphorylation (Thr 172), AMPK activity, and raptor phosphorylation (Ser 792) were not increased with the initiation of weight loss, but were induced as cachexia progressed. ATP dependent protein degradation increased during the initiation and progression of cachexia. However, ATP independent protein degradation was not increased until cachexia had progressed beyond the initial phase. IL-6 receptor antibody administration prevented body weight loss and suppressed muscle protein degradation, without any effect on muscle %MPS or IGF-1 associated signaling. In summary, the %MPS reduction during the initiation of cachexia is associated with IGF-1/mTOR signaling repression, while muscle AMPK activation and activation of ATP independent protein degradation occur later in the progression of cachexia. IL-6 receptor antibody treatment blocked cachexia progression through the suppression of muscle protein degradation, while not rescuing the suppression of muscle protein synthesis. Attenuation of IL-6 signaling was effective in blocking the progression of cachexia, but not sufficient to reverse the process

A meta-analysis of cross sectional studies investigating language in maltreated children

Purpose: In this review article, meta-analysis was used to summarize research investigating language skills in maltreated children. Method: A systematic search of published studies was undertaken. Studies were included in the meta-analysis if they investigated language skills in groups comprising maltreated and nonmaltreated children. Studies were selected if these 2 groups of children were of comparable age and from a similar socioeconomic background. Results: A total of 26 studies were identified that met the inclusion criteria. Results from the meta-analysis showed that maltreated children demonstrated consistently poorer language skills with respect to receptive vocabulary (k = 19; standardized mean difference [SMD] = .463; 95% confidence interval [CI; .293, .634]; p < .001), expressive language (k = 4; SMD =.860; 95% CI [.557, 1.163]; p < .001), and receptive language (k = 9; SMD =.528; 95% CI [.220, .837]; p < .001). Conclusion: Together, these results indicate a reliable association between child maltreatment and poor language skills

New Dawn : a 23 min documentary drama based on an ex-drug addict's life story

New Dawn is a 23min documentary drama that recites the painful life story of an ex-drug addict, Don Wong, who is now the Director of the Highpoint Drug Rehabilitation Centre in Singapore, located at Amber Road.Bachelor of Communication Studie

Compressive strength characteristic values of nine structural sized Malaysian tropical hardwoods

The design practice of timber structures in Malaysia is still based on permissible stress codes as stated in Malaysian Standard (MS) 544: Part 2 and MS 544: Part 3, which was adopted from the British Standard (BS) 5268. The British Standard was later completely replaced by Eurocode 5 (EC5) in 2009. Therefore, to preserve the continuity of design concepts specified in the British code of practice, local designers should adopt an EC5 limit state design to generate safe and economical designs. However, new strength data based on characteristic values which comply with EC5 for Malaysian tropical hardwoods are still lacking. The aim of this study was to investigate the compressive strength properties of nine structural-sized Malaysian tropical hardwood species namely Balau, Kempas, Kelat, Resak, Kapur, Keruing, Mengkulang, Light Red Meranti and Geronggang tested according to European Standard (EN) 408. A compression test was performed to measure the compressive strength and modulus of elasticity of the timbers and were used to derive characteristic values. The equation for determining characteristic compressive strength given in EN 384 was also assessed to verify that whether it is suitable for high density Malaysian hardwoods, as this equation was derived from softwood and European hardwoods. The results revealed that the derived characteristic values are higher than the values given in EN 338 for the relevant strength classes, particularly for heavy and medium hardwood with densities greater than 700 kg/m3. A verification of the equation used in EN 384 to determine compressive strength characteristic value yields a different equation, (Formula presented.). This shows that the EN 384 equation is not suitable to be used with hardwood timber with a density more than 700 kg/m3, since it will underestimate the strength value

Compressive Strength Characteristic Values of Nine Structural Sized Malaysian Tropical Hardwoods

The design practice of timber structures in Malaysia is still based on permissible stress codes as stated in Malaysian Standard (MS) 544: Part 2 and MS 544: Part 3, which was adopted from the British Standard (BS) 5268. The British Standard was later completely replaced by Eurocode 5 (EC5) in 2009. Therefore, to preserve the continuity of design concepts specified in the British code of practice, local designers should adopt an EC5 limit state design to generate safe and economical designs. However, new strength data based on characteristic values which comply with EC5 for Malaysian tropical hardwoods are still lacking. The aim of this study was to investigate the compressive strength properties of nine structural-sized Malaysian tropical hardwood species namely Balau, Kempas, Kelat, Resak, Kapur, Keruing, Mengkulang, Light Red Meranti and Geronggang tested according to European Standard (EN) 408. A compression test was performed to measure the compressive strength and modulus of elasticity of the timbers and were used to derive characteristic values. The equation for determining characteristic compressive strength given in EN 384 was also assessed to verify that whether it is suitable for high density Malaysian hardwoods, as this equation was derived from softwood and European hardwoods. The results revealed that the derived characteristic values are higher than the values given in EN 338 for the relevant strength classes, particularly for heavy and medium hardwood with densities greater than 700 kg/m3. A verification of the equation used in EN 384 to determine compressive strength characteristic value yields a different equation, fc,0,k=2.2 fm,k0.7. This shows that the EN 384 equation is not suitable to be used with hardwood timber with a density more than 700 kg/m3, since it will underestimate the strength value

Compressive Strength Characteristic Values of Nine Structural Sized Malaysian Tropical Hardwoods

The design practice of timber structures in Malaysia is still based on permissible stress codes as stated in Malaysian Standard (MS) 544: Part 2 and MS 544: Part 3, which was adopted from the British Standard (BS) 5268. The British Standard was later completely replaced by Eurocode 5 (EC5) in 2009. Therefore, to preserve the continuity of design concepts specified in the British code of practice, local designers should adopt an EC5 limit state design to generate safe and economical designs. However, new strength data based on characteristic values which comply with EC5 for Malaysian tropical hardwoods are still lacking. The aim of this study was to investigate the compressive strength properties of nine structural-sized Malaysian tropical hardwood species namely Balau, Kempas, Kelat, Resak, Kapur, Keruing, Mengkulang, Light Red Meranti and Geronggang tested according to European Standard (EN) 408. A compression test was performed to measure the compressive strength and modulus of elasticity of the timbers and were used to derive characteristic values. The equation for determining characteristic compressive strength given in EN 384 was also assessed to verify that whether it is suitable for high density Malaysian hardwoods, as this equation was derived from softwood and European hardwoods. The results revealed that the derived characteristic values are higher than the values given in EN 338 for the relevant strength classes, particularly for heavy and medium hardwood with densities greater than 700 kg/m3. A verification of the equation used in EN 384 to determine compressive strength characteristic value yields a different equation, fc,0,k=2.2 fm,k0.7. This shows that the EN 384 equation is not suitable to be used with hardwood timber with a density more than 700 kg/m3, since it will underestimate the strength value

Depth Effect of Tropical Heavy Hardwood of Kekatong Species Towards EC5 using Weibull’s Theory

The design practice has shifted from permissible stress design to limit state design using Eurocode 5 (EC5), which introduces design strength optimization. However, the adoption of EC5 in Malaysia cannot be done directly due to the absence of design strength data for Malaysian timber species. This paper presents a study that evaluates the bending strength properties, moisture content, and density of kekatong (Cynometra malaccensis) timber specimens using the Weibull theory to produce 1/k values for the local timber species. The depth impact adjustment factors for kekatong timber had a value of 0.23, which is not far from the well-established 1/k value of 0.2 for softwood and temperate hardwood with characteristic densities below 700 kg/m3 in EC5. The study shows that the bending strength of local timber is affected by its volume, and the variation of bending strength at several probabilities is in close agreement with theoretical predictions. Overall, the study provides important insights for the design of timber structures using Malaysian timber species, which can be used to improve the safety and sustainability of timber structures