This paper reports the mechanical properties of cement composite boards made using wood-wool from a lesser known Malaysian timber species. A total of 108 specimens were fabricated using Portland cement (Type I) and wood-wool from Kelampayan (Neolamarckia cadamba). The cement to wood ratio of the specimens was 2 to 1 by weight. The aim of the study was to determine the density; flexural, compressive and tensile strength of wood-wool cement composite boards (WWCCB) by studying boards with wood-wool sized 1.5 mm, 2.5 mm and 3.5 mm and board thickness 25 mm, 50 mm and 75mm. The physical and mechanical properties of the boards were evaluated according to ASTM D 1037-96a (Standard testing method for evaluating properties of wood-based fibre and particle panel materials) and MS934:1986. Results showed that mechanical properties of WWCCB were greatly influenced by the density; as the density decreased, the mechanical strengths also decreased. However, the strength properties of the composite boards did not display a similar trend when subjected to different types of loading conditions. The compressive strength increased with thicker boards (50 mm and 75 mm) but the modulus of elasticity and modulus of rupture declined as the thickness of the board was increased.
The government’s science and technology (S&T) apparatus is now in active consultation to formulate the third national S&T policy (NSTP3) and I have been involved in some of these meetings and have benefitted from them. In an earlier article (New Straits Times, 9 July 2011, p. 18) I had briefly described the two previous policies and given some thought on what the essentials of the NSTP3 should be. I am now offering some further thoughts on the subject. (Copied from article).
Warm compaction is an advanced manufacturing technique which consists of two consecutive steps, i.e. powder compaction at above ambient temperature and sintering in a controlled environment. Due to the relative movement between the powder mass and die wall as well as sliding among powder particles, frictional force is generated during the compaction stage. Admixed lubricant is used during the compaction step in order to minimize friction and hence improve the uniformity of the density of distribution inside the component. However, during the sintering process, trapped lubricant is often found to be burnt out hence leaving pores or voids which result in the lower strength of the final products. Warm compaction was initiated in the nineties, however not much information has been published about the effects of lubrication on the quality of the components produced through this route. Therefore, this paper presents the outcome of an experimental investigation about the effects of lubrication on manufacturing near-net shape components through the warm compaction route. Iron powder ASC 100.29 was mixed mechanically with zinc stearate to prepare the feedstock. Mixing time, weight percentage of lubricant content and compaction temperature were varied during green compact generation while sintering temperature, heating rate and holding time were manipulated during sintering. The relative densities and strengths of the final products were investigated at every compaction as well as sintering parameter. The results revealed that lubrication could provide significant effects at the compaction temperature of 180ºC while no significant effect of lubrication was observed during sintering. The suitable lubricant content was found to be 0.4 wt% and mixing time was around 30 min and the sintering temperature was around 990ºC.
Industrial statistics is an important part of the management system in any industry that strives to continuously improve quality and increase productivity and efficiency. That system covers supply chain management, production design and prototyping, production process and marketing. Industrial statisticians, industrial engineers and industrial leaders should work together hand in hand, in the same language, to ensure that the process and products are as expected. The system itself is never complete. Thus, the usefulness, manageability and reliability of all statistical models used in the system are to be considered as first priority, but those skills are not sufficient. Industrial statisticians should also, of course, be able to come and go between the two poles: statistics and industry. This requirement needs a good understanding about the culture of these poles and how to conduct a mutual symbiosis. One of the principal bridges between these cultures is statistical process control (SPC). This paper is to show that modern industry cannot escape from SPC, especially in a multivariate setting. This setting, which characterizes modern industry, consists of two philosophical problems: how to order data and how to measure process variability. Our recent research results sponsored by the Government of Malaysia will be presented to illustrate the challenging statistical problems in modern industry.
Researchers have developed and modified DNA biosensor techniques to provide a fast, simple and sensitive method for detection of human diseases, bacterial food contamination, forensic and environmental research. This study describes the physical characterization of screen-printed carbon electrodes using the scanning electron microscope.
Current National Design Specification (NDS 2005) provides the guideline to design timber joints strengthened with steel fasteners. This study investigates the possibility of using NDS 2005 to estimate the load-carrying capacity of timber joints fastened with Glass Fibre Reinforced Polymer (GFRP) dowel. Double shear timber joint fastened with steel dowels were tested to validate the joints fastened with GFRP using 1.27 cm diameter dowels. Tests were also conducted to determine the dowel bearing strength of wood and dowel bending strength of GFRP and steel. The failure modes of all tests were observed and recorded. Results showed that NDS (2005) successfully estimated the failure mode and was capable of predicting the joint load-carrying capacity when fastened with a GFRP dowel and this was well validated by the load carrying capacity of a steel dowel.
Human activity has ‘very likely’ been the primary cause of global warming since the start of the Industrial Revolution (18th–19th century). As a new player in industrial transformation, Malaysia can choose to ignore the warnings of global warming. blame. This may not augur well. Release of greenhouse gases have been categorically linked to climate change and global warming. In her march towards industrialization, Malaysia too has contributed to the release of greenhouse gases. Apart from those arising from natural sources, the industrial sector in Malaysia also releases other types of gases such as the fluorocarbons. This is evident from the worsening air quality in some of our cities. (Copied from article).
In this present study, a series of polymer electrolyte thin films were synthesized by incorporating different ratios of lithium triflate (LiCF3SO3) in a low molecular weight polyvinyl chloride (PVC) matrix by the solution casting technique. The incorporation of LiCF3SO3 suppressed the high degree of crystallinity in PVC enabling the system to possess an appreciable ionic conductivity. The ionic conductivity of the samples, with different LiCF3SO3 content, was determined by the aid of ac impedance spectroscopy. The highest ionic conductivity of 4.04 10–9 S cm–1 was identified for the composition of PVC: LiCF3SO3 (75:25). Further understanding of the ionic conductivity mechanism was based on temperature-dependent conductivity data which obeyed Arrhenius theory, indicating that the ionic conductivity enhancement was thermally assisted. The possible dipole-dipole interaction between the chemical constituents was confirmed with changes in cage peak, analysed using Fourier transform infrared spectroscopy.
In December 2009, at the UN Climate Change Conference COP 15 in Copenhagen, the Prime Minister of Malaysia, the Rt. Hon. Mohd Najib Abdul Razak, had announced that “Malaysia is adopting an indicator of a voluntary reduction of up to 40% in terms of emissions intensity of GDP by the year 2020 compared to 2005 levels. This indicator is conditional on receiving the transfer of technology and finance of adequate and effective levels from Annex 1 partners, that correspond to what is required in order to achieve this indicator”. Malaysia also needs to decouple its GDP from its current relatively high carbon-based energy demand. In trying to meet both these targets, we need to intensify our research efforts in energy-based areas. As government funding in R&D is limited as the aim is for research to be private-sector driven, and with the grim global economic scenario today, it is most unlikely that Malaysia will get any assistance financially or technologically from Annex 1 nations. It is therefore proposed that Malaysia considers implementing a dedicated carbon cess on petroleum products to fund R&D in the country. (Copied from article).
Several binary and ternary medium- and long-chain triacylglycerol (MLCT)-enriched margarine formulations were examined for their solid fat content, heating profile, polymorphism and textural properties. MLCT feedstock was produced through enzymatic esterification of capric and stearic acids with glycerol. The binary formulations were produced by mixing MLCT feedstock blend (40%–90%) and palm olein (10%–60%) with 10% increments (w/w). Solid fat profiles of commercial margarines were used as a reference to determine the suitability of the formulations for margarine production. The solid fat content of the binary formulations of MO 82 and MO 91 (M, MLCT, O, palm olein) were similar to the commercial margarines at 25°C which met the basic requirement for efficient dough consistency. Ternary formulations using reduced MLCT feedstock blend proportion (from 80%–90% to 60%–70%) were also developed. The reduction of MLCT feedstock blend was
done as it had the highest production cost (3USD/kg) in comparison to palm olein (0.77USD/kg) and palm stearin (0.7USD/kg). The proportions of 5%–15% of palm stearin were substituted with palm olein in MO 64 and MO 73 (M, MLCT; O, palm olein) formulations with 5% increment (w/w). As a result, MOS 702010 and MOS 603010 (M, MLCT; O, palm olein; S, palm stearin) margarine formulations showed similar SFC % to the commercial margarines at 25ºC. These formulations were subsequently chosen to produce margarines. The onset melting and complete melting points of MLCT-enriched margarine formulations were high (51.04ºC –57.93ºC) due to the presence of a high amount of long chain saturated fatty acids. Most of the formulations showed β΄- crystals. MOS 702010 was selected as the best formulation due to values for textural parameters comparable (P
In agricultural systems, animals play a very important multifunctional role for developing communities
throughout the world. This is reflected in the generation of value-added products like meat, milk and eggs for food security; socio-economic benefits like increased income, security and survival, and an infinite variety of services such as the supply of draught power and dung for soil fertility. However, and despite this importance, the situation is awesome since the projected total meat and milk consumption levels in 2020 are far in excess of anticipated supply, and projections of both meat and milk will have to be doubled by 2050 to meet human requirements. Strategies for productivity growth from animals are therefore urgent, and are discussed in the context of the scenario of waning agriculture, extreme poverty and hunger, food crisis, the current contributions from the components of the animal industries, prevailing constraints, opportunities and strategies for improved production. Current trends suggest that the non-ruminant pig and poultry industries will continue to contribute the major share of meat and all of egg production to meet projected human needs. With ruminants by comparison, overall meat production continues to come mainly from the slaughter of numbers. Strategic opportunities exist for maximising productivity in improved production systems. These include targeting rainfed areas, development of small farms, integrated crop-animal systems, intensive application of productivity-enhancing technologies, promoting intensive use of crop residues and expanding the R&D frontiers with interdisciplinarity and farming
systems perspectives. The issues, together with increased investments and institutional commitment, provide for expanded animal production systems and productivity which can forcefully impact on improved human welfare in Asia in the immediate tomorrow.
In this study the effects of phosphorus and nitrogen levels, temperature and light-dark cycle on the algal growth potential (AGP) of an Antarctic Chlorococcum isolated from an ephemeral stream at Reeve Hill, Antarctica was investigated. The highest AGP was attained when the cultures were grown at high nitrogen concentration (329.87 mg NO3-N/l) and low phosphorus concentration (2.6 mg PO4-P/l) at 4ºC on a 12 h:12 h light-dark cycle. The results showed that Chlorococcum sp. required a high concentration of nitrogen, low concentration of phosphorus, low temperature with equal lengths of light and dark period (12 h:12 h) for optimum growth.
In this study polymer electrolytes composed of poly(methyl methacrylate) (PMMA) as a host polymer and ethylene carbonate (EC) as a plasticizer complexed with different lithium salts, i.e. lithium tetrafluoroborate (LiBF4) and lithium triflate (LiCF3SO3) were prepared by the solution casting technique. The conductivities of the films were characterized by impedance spectroscopy. At room temperature, the highest conductivities were 4.07 × 10–7S cm–1 and 3.40 × 10–5 S cm–1 achieved, respectively from the films containing 30 wt% LiBF4 in the PMMA-EC-LiBF4 system and 35 wt% LiCF3SO3 in the PMMA-EC-LiCF3SO3 system. The conductivity-temperature dependence of the films seemed to obey the Arrhenius equation in which the ion transport in these materials was thermally assisted. Scanning electron microscopy analysis showed that the surface of PMMA-EC-LiCF3SO3 film was smooth and homogeneous, hence lithium ions could traverse through the PMMA-EC-LiCF3SO3 film more easily compared to the PMMA-EC-LiBF4 film. X-Ray diffraction studies revealed that complexation had occurred and the complexes formed were amorphous.
Elevated temperature affects marine benthic algae by reducing growth and limits the transport of electron or carbon fixation which may reduce the ability of the cell to use light. This resulting excess light energy may cause photoinhibition. In this study, the photosystem II of the benthic microalgal communities from Casey, eastern Antarctic were relatively unaffected by significant changes in temperatures up to 8ºC, along with high PAR level (450 μmol photons m–2 s–1). Similarly, the community was able to photosynthesize as the temperature was reduced to –5ºC. Recovery from saturating and photoinhibiting irradiances was not significantly influenced by temperatures at both –5ºC and 8ºC. These responses were consistent with those recorded by past experiments on Antarctic benthic diatoms and temperate diatoms which showed that climate change did not have a significant impact on the ability of benthic microalgae to recover from photoinhibitory temperature stress.
Frequency hopping spread spectrum (FHSS) systems with partial band interference require appropriate compounding of spread spectrum modulation, error correcting code, diversity and decoding method to receive improved transmission signal. In this paper, a fast FHSS system with regular low-density parity-check codes was employed to cater some anti-jamming competence by using good waterfall and error floor performance. The performance evalution of the previously mentioned system was conducted in the presence of partial band noise jamming. The best possible design of the system was achieved with the combination of diversity level L=2 with a probability rate of at 0.7 dB which showed the robustness of the system.
Introducing CO2 flux as the carbonate source had an effect on the carbonate content of carbonate apatite (CAp) synthesized by solid state reaction. The reactants were CaCO3 and beta-tricalcium phosphate (β-TCP) and the heat treatment in air was performed at 1250ºC followed by instant cooling in CO2 flux for temperatures ranging from 800ºC room temperature (RT) . The influence of CO2 flux at various temperature drop differences in the cooling process (1250ºC RT, 1250ºC–500ºC, 1250ºC–600ºC, 1250ºC–700ºC, and 1250ºC–800ºC) was tested to optimize the carbonation degree and subsequent effects on the physical and mechanical properties of CAp. Thermally treated samples revealed an increasing degree of carbonation, achieving a maximum of 5.2 wt% at the highest (1250ºC RT) and a minimum of 2.7 wt% at the lowest (1250ºC–800ºC) temperature drop differences, respectively. This showed that the carbonate content was correlated with the increase in exposure to CO2 flux. However, consistent compressive strength, tensile strength, density and porosity were observed against increasing temperature drop differences which indicated that the degree of carbonation exerted no influence on the physical and mechanical properties of CAp. This method enabled the synthesis of solid state CAp simply by exposing calcium phosphate mixtures to CO2 flux. It also allowed the control of carbonate content for desired medical applications.
Ordered microporous NaY zeolite and mesoporous copper oxide are high performance material as catalysts and adsorbents. The copper oxide-NaY zeolite modification in combination of their physicochemical properties could provide excellent opportunities for the creation of new gas adsorbents. In this study, modified NaY zeolite properties and methane adsorptive characteristics were investigated by dispersing copper oxide onto the NaY zeolite structure using the thermal dispersion method. The structures of the copper oxide modified zeolites were characterized by powder X-ray diffraction and Micromeritics ASAP 2000, while the methane adsorption characteristics were analyzed using a thermogravimetric analyzer. The results revealed that types of copper oxide, copper oxide loading concentration, calcination temperature and calcination time greatly affected the modified zeolite structure and gas methane adsorption characteristics.
Stem cells from human extracted deciduous teeth (SHED) have the ability to multiply much faster and double their population in culture at a greater rate, indicating that it may be in a more immature state than other type of adult stem cells. Mesenchymal stem cells (MSC) from human primary molars were isolated and cultured in media supplemented with 20% fetal bovine serum. The MSCs were confirmed using CD 105 and CD 166 and the identification of the osteoblast cells were done using reverse transcriptase polymerase chain reaction (RT-PCR) analysis. Differentiated osteoblast cells (DOC) were characterized by alkaline phosphotase and von Kossa staining followed by immunocytochemistry staining using osteocalcin and osteonectin antibodies. Further validation of SHED was done by RT-PCR to detect the presence of insulin-like growth factor 2 (IGF-2) and discoidin domain tyrosine kinase-2 (DDTK-2) transcripts, while the presence of Runx-2 mRNA was used to characterize DOC. The results showed that SHED was found positive for CD 105 and CD 166 and could differentiate into osteoblast, bone forming cells. The findings revealed the presence of distinct MSC population which had the capability to generate living human cells that could be a possible source for tissue engineering in the future.
Awareness and sensitivity on the subject of green technology are currently commanding the attention of the world in the light of rising energy costs and the threat of global warming. Many countries are now recognizing the benefits of researching into and using green technology to reduce their carbon and water footprints and to minimize waste. (Copied from article).
Studies conducted on the various geometric properties of skeletons of water bodies have shown highly promising results. However, these studies were made under the assumption that water bodies were static objects and that they remained constant over time. Water bodies are actually dynamic objects; they go through significant spatio-temporal changes due to drought and flood. In this study, the characterization of skeletons of simulated drought and flood of water bodies was performed. It was observed that as the drought level increased from 1 to 9, the average length of the skeletons decreased due to reduction in the size of the water bodies and increase in the number of water bodies. As the drought level increased from 9 to 15, the average length of the skeletons increased further due to vanishing of small water bodies. Flood caused an increase in the average length of the skeletons due to merging of adjacent water bodies. Power law relationships were observed between the average length of the skeletons of the simulated drought/flood and the level of drought/flood. The scaling exponent of these power laws which was named as a fractal dimension, indicated the rate of change of the average length of the skeletons of simulated drought/flood of water bodies over varying levels of drought/flood. However, errors observed in the goodness of fit of the plots indicated that monofractals were not sufficient to characterise the skeletons of simulated drought and flood of water bodies. Multifractals and lacunarity analysis were required for more accurate characterisation.