This paper reviews the advances made on studies related to bank erosion. Bank erosion has been an area of interest by researchers in geological, geotechnical, hydraulic, hydrology and river engineering disciplines. With anticipated global challenges from climate change impacts, bank erosion studies could support challenges faced in ensuring sustainable environmental management. The evolution in the theoretical and laboratory findings have led to the advances in bank erosion and contributed to new knowledge in the said field. This review summarises the findings of previous investigators including measurements approach and prediction of rates of bank erosion through the use of physical models and numerical approach.
Finding a proper transition structure for the peptide bond formation process can lead to a better understanding of the role of the ribosome in catalyzing this reaction. A potential energy surface scan was performed on the ester bond dissociation of the P-site aminoacyl-tRNA and the peptide bond formation of P-site and A-site amino acids. The full fragment of initiator tRNAi met attached to both cognate (met) and non-cognate (ala) amino acids as the P-site substrate and the methionine as the A-site amino acid was used in this study. Due to the large size of tRNA, ONIOM calculations were used to reduce the computational cost. This study illustrated that the rate of peptide bond formation was reduced for misacylated tRNA without the presence of ribosomal bases. This demonstrated that there were indeed specific structural interactions involving the amino acid side chain within the tRNAi met.
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.
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.
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.
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.
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 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).
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).
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).
A study to determine the impact of leachate from operating and closed landfills into the surface water and groundwater systems in the state of Selangor was conducted in the year 2009. Groundwater was a major source of water for various uses in Selangor, Malaysia and was especially important for industrial purposes. The presence of high numbers of landfill sites was seen to have increased the risk of groundwater contamination. There were 20 landfill sites in the state of Selangor and seven of them were still operating and 13 closed. The landfills are classified into four categories, which were: (a) landfills operating at critical stages without controls to prevent pollution into the environment; (b) open dumpsites that have the capacity to continue to accept waste but needed to be upgraded to manage leachate and gas; (c) landfills that were closed but no safety closure plan was carried out; and (d) engineered landfills with up to date technologies. As most of the landfills were built prior to 1989, they were not subjected to the Environmental Impact Assessment requirements, hence, they were being poorly managed and were badly sited. The non-engineered sites had no proper pollution controls such as cover materials, liner materials, groundwater monitoring wells, leachate collection ponds and treatment, and methane gas collection pipes. This study revealed that the surface water and groundwater at and nearby the landfill sites were contaminated at various levels due to the landfill sites and operation. A comparison between the current quality of surface water and groundwater with their respective standards and background levels was carried out to survey the trend of the contamination. However, the limited financial resources hindered a very thorough investigation and restricted the number of samples collected and parameters analysed.
Lead-free solder paste printing processes account for the majority of assembly defects in the electronic manufacturing industry. In the stencil printing process, the solder paste must be able to withstand low and high shear rates which result in continuous structural breakdown and build-up. This study investigated the effect of the addition of nickel and platinum powders to the thixotropic behaviour of lead-free Sn/Ag/Cu solder pastes using the structural kinetic model. A hysteresis loop test and constant shear test were utilized to investigate the thixotropic behaviour of the pastes using parallel plate rheometry at 25ºC. In this study, the shear rates were increased from 0.01 s–1 to 10 s–1 and the second curve was a result of decreasing the shear rate from 10 s–1 to 0.01 s–1. For the constant shear test, the samples were subjected to five different shear rates of 0.01s–1, 0.1s–1, 1s–1, 10s–1 and 100s–1. The constant shear rate test was designed to study the structural breakdown and build-up of the paste materials. From this investigation, the hysteresis loop test was shown to be an effective test method to differentiate the extent of structural recovery in the solder pastes. All the pastes showed a high degree of shear thinning behaviour with time. This might be due to the agglomeration of particles in the flux that prohibited paste flow under low shear rate. The action of high shear rate would break the agglomerates into smaller pieces which facilitated the flow of pastes, thus viscosity was reduced at high shear rate.
The effects of anticipated climate change and the potential impact on animal production are discussed in the context of varying biophysical features, agro-ecological zones (AEZs), ecosystems, land use, and responses in animal genetic diversity and production. The AEZs in Asia have great diversity in their links to food production in crop-animal small farm systems, the poverty complex and livelihoods of the poor. In these environments. climate change effects on animals were mediated through heat stress, water availability, quantity and quality of the available feed resources, type of production system and productivity. The responses to heat stress are tabulated and they vary according to species, breeds within-species, AEZs, physiological and nutritional status, genetic potential and multifunctionality. Among ruminant production systems, dairy production was especially vulnerable to heat stress. Interestingly in India, buffalo numbers owned largely by the landless and small farmers in the semi-arid and arid regions have grown twice as fast as the buffalo population in the irrigated areas. The implications and strategies to cope with climate change involve mitigation, adaptation and policy. The principal strategy is targetting to the reduce on in greenhouse gas (GHG) emission from the agricultural sector from enteric fermentation and manure, and ways to intensify C sequestration. An important link is that of breeding and conserving indigenous animal genetic resources as a means to mitigate climate change, with associated benefits to the trade of live animals and animal products. Improved integrated tree crops-ruminant systems are an important pathway to enhance C sequestration. The opportunities for research and development (R&D) are enormous and they would need policy support and large investments to provide improved understanding of ways to ensure sustainable animal production systems. Coping with the totality of the effects and impact of climate change constitutes the challenges for agricultural R&D and the improved livelihood of the resource-poor in the future.
Malaysia has adopted various strategies in developing its space sector. Indigenous space technologies would enable a sustainable growth of the space field and at the same time develop the strategic space technologies. Therefore, issues related to the current space research level are fundamentally crucial to be highlighted. Subsequently, the space focus areas can be derived in order to meet the expectations of the national and international space technology growth requirements, which are moving on to a stronger posture in R&D. In the absence of a strong R&D national space industry leadership, the Malaysian space sector remains in a traditional downstream mode of the world space technology supply chain ever since. The space technology supply chain can be divided into the ground segment and the space segment. This paper examines the current space research activities in Malaysia within the framework of the space technology supply chain. As a result, a preliminary gap in the overview of space research in Malaysia is established.
Reflex epilepsy is usually induced by external stimulation, photosensitive epilepsy being the most common. Epilepsy induced by auditory stimulation is rarely studied. There are no currently published magnetoencephalographic (MEG) studies demonstrating the initiation of epileptic neuronal discharges by repeated auditory stimulations in temporal lobe epilepsy (TLE) patients. We retrospectively studied one TLE patient who underwent a MEG study to localize her epileptic focus. Auditory, somatosensory, visual and motor evoked potential studies were performed during the MEG recording. A single dipole method calculated equivalent current dipoles to localize the epileptic source. The least-squares minimization method was used to obtain the optimal solution with goodness-of-fit of greater than 80%. Periodic lateralized epileptiform discharges (PLEDs) were recorded in the temporal region when repeated auditory stimulations were done. We postulated that neuronal cortical suppression occurred during repeated stimulations which provoked epileptiform discharges (PLEDs) without any physical symptoms or aura. It was concluded that repeated stimulations could facilitate epileptiform discharges in focal area/areas in certain subjects.
Almost a half century after it was introduced, Wilks’ statistic has come into application in industrial manufacturing process variability monitoring. This is an important breakthrough in the way experts monitor the variability of manufacturing processes which is vital in modern industry. It leaves behind the traditional practice characterized by the use of sample size n which equals 1, if the process variability monitoring is based on individual observations and is greater than the number of variables p if one works with subgroup observations. The use of Wilks’ statistic allows us to work with n < p. This paper contains a review on process variability monitoring based on individual observations. First, some historical backgrounds of process variability monitoring in the general scheme was reviewed before it was revealed where the philosophy of Wilks’ statistic could be further interpreted. Subsequently it was indicated that the way to monitor the process variability depended on how the variability itself was measured. Finally, a new statistic for detecting the shift in variability based on individual observations was introduced and then a new control chart was proposed. The performance of the proposed chart as compared with Wilks chart, was quite promising. Therefore, some recommendations were given to better understand the history of manufacturing process variability.
The functionalization of pristine CNTs is necessary for carbon nanotubes (CNTs) to be fully utilized, with the aim of increasing the nanotube reactivity and solubility in aqueous solutions. In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized with a carboxylic group as this was an important step prior to application. The carboxylic group-functionalization was conducted through acid treatment, using sulphuric and nitric acids mixed at a ratio of 3:1 (v/v) and sonication for 30 min under different temperatures and time durations. The functionalization conditions of 50ºC x 5 h and 60ºC x 3 h were identified to be most suitable for introducing a carboxylic group onto the nanotube surfaces. The percentage of total weight loss due to the carboxylic group on the MWCNTs treated at 50ºC x 5 h and 60ºC x 3 h obtained from the thermogravimetric analysis was 13.26% and 13.76%, respectively. For both samples, peaks corresponding to the carboxylic group were identified in the FT-IR spectra. The changes in the morphology of the treated MWCNTs were also observed under SEM analysis.
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.