Batu Reput’ is primary sediment mineral and abundantly found in Perlis. Perlis is one of the major producers of ‘Batu Reput’ in Malaysia that content large deposit of high-purity dolomite [CaMg (CO3)2]. Pure samples of ‘Batu Reput’ recently explored in the Koperasi Rimba Mas Padang Besar Quarry were investigated for their physical, chemical and mineralogical composition. SEM and XRD analysis methods were applied. The potential of ‘Batu Reput’ as a raw material in fertilizer production was investigated in this paper.
The amount of sugarcane bagasse and rice straw in the state of Perlis (Malaysia) is abundant while its utilization is still limited. One of the alternatives for the bagasse and straw utilization is as pulp raw material. This paper reviews on pulp from sugarcane bagasse and rice straw and its suitability for paper production. In this study, the pulp was extracted by the Soxhlet extraction method. The objective of this study was to investigate the cellulose, lignin and silica content of the pulp from sugarcane bagasse and rice straw. For rice straw, the presence of large amount of pentosanes in the pulp and black liquors, which also contain silica were decreased the using of straw in the paper industry. Therefore, formic acid pulping and NaOH treatment are studied to reduce or prevent silica. The isolated pulp samples were further characterized by Scanning Electron Microscope (SEM) to investigate their fiber dimensions.
The storage of oil sludge at refineries is a major problem to the petroleum industry. Oil sludge treatments such as by using sludge farming, incineration, physical and chemical techniques have been applied to separate the hydrocarbon from the solid sediment. The paper relates a characteristic study performed on solid sediment from a local oil sludge sample for making sintered brick. The study includes the used of XRD, XRF, digital microscopy and particle size analyzer. The result shows that the sample highly contains quartz minerals with particle size ranging from 0.5 – 200 ȝm. The chemical phosphorous from the surfactant can be removed by washing to make this solid sediment to be used as a material in the brick making.
The paper looks into the possibility of using standard addition method to analyse uranium and thorium in tin slag. Tin slag samples obtained from Butterworth was grind to 180 ȝm and injected with different concentrations of uranium and thorium. Linear calibration graphs were obtained for both these samples with R 2 values for uranium and thorium as 0.9989 and 0.9915 respectively. Based on this graphs, the initial uranium and thorium in the tin slag sample was established as 60 ppm for uranium and 160 ppm for thorium.
The main objective of this paper is to explore the varying volatility dynamic of inflation rate in Malaysia for the period from January 1980 to December 2004. The GARCH, GARCH-Mean, EGARCH and EGARCH-Mean models are used to capture the stochastic variation and asymmetries in the economic instruments. Results show that the EGARCH model gives better estimates of sub-periods volatility. Further analysis using Granger causality test show that there is sufficient empirical evidence that higher inflation rate level will result in higher future inflation uncertainty and higher level of inflation uncertainty will lead to lower future inflation rate.
Good Clinical Practice (GCP) is an international ethical and scientific quality standard for the design, conduct, performance, monitoring, auditing, recording, analyses and reporting of clinical trials. It also serves to protect the rights, integrity and confidentiality of trial subjects. It is very important to understand the background of the formation of the ICH-GCP guidelines as this, in itself, explains the reasons and the need for doing so. In this paper, we address the historical background and the events that led up to the formation of these guidelines. Today, the ICH-GCP guidelines are used in clinical trials throughout the globe with the main aim of protecting and preserving human rights.
Since the discovery of carbon nanotubes (CNTs) in 1991, a fundamental question still remained on how to control morphologically the synthesis of CNTs. This task has always been a challenge. In this paper, we report the results that we have published previously with the aim of sharing the possible controlled synthesis approach via this novel production method. Findings demonstrated that various CNTs could be synthesized by using specially developed supported catalysts from the catalytic decomposition of methane. These synthesized CNTs include carbon nanofibres, single-walled and multi-walled CNTs, Y-junction CNTs and CNTs with special morphologies. It was also revealed that catalyst composition and reaction parameters played an important role in controlling the morphology and type of CNTs formed. The synthesis of CNTs with various morphologies is important because this can enrich the nanostructures of the carbon family. This finding also provides useful data for better understanding of the parameters that govern the growth mechanism of CNTs which may be required in the near future for enhanced controlled synthesis of CNTs.
The importance of zeolite surface area and pore volume in adsorption processes has been much reported in literature. In addition to that, structural framework and pore network system may also influence the adsorption capacity and selectivity of methane on zeolite. This paper discusses the characteristics of methane adsorption based on several physical properties of the adsorbents such as surface area, pore volume, pore network system and its interaction with adsorbate. The study, using FTIR spectroscopy showed that the adsorbed methane at room temperature was detected in the FTIR region between 3200 cm–1 – 1200 cm–1. Based on the physical properties of the adsorbents and the FTIR spectra of adsorbed methane, the surface area was not the only factor that determined methane adsorption; in fact the type of pore network system of the adsorbent also affected the interaction, thus affecting the adsorption of methane in zeolite.
Katabatic winds dramatically affect the polar climate. Their activity depends on density of air and temperature in the source region. This paper presents for first time an analysis of the precipitable water vapour (PWV) variability and its relation to a katabatic event at Scott Base station, Antarctica. A significant effect in their characteristics toward calculation of a reliable user accuracy in GPS applications is addressed. Our investigations using the data between 21st and 30th of November 2002 showed that the PWV profile exhibited an irregular pattern with a maximum value of 7.38 mm (~ 6 mm on average), and was more strongly influenced by relative humidity than by wind speed activity. The dominant wind flow during this period was from the North-Northeast (blowing from the Ross Sea) with a median speed of 4.96 ms–1. The PWV was high when the temperature was between –15ºC and –11ºC. During the dates identified as a katabatic event between 21:30 UT of 28th November and 18:40 UT on 29th November, the wind blew from the Southeast-South direction (from the Ross Ice Shelf) with a maximum speed of 10.92 ms–1. The PWV increased ~1.4 mm (23%) from the mean value, indicating severe wind during this event which had pronounced effect on GPS observations.
This paper introduces a method for modification of the formula of the fractal box counting dimension. The method is based on the utilization of the probability distribution formula in the fractal box count. The purpose of this method is to use it for the discrimination of oil spill areas from the surrounding features e.g. sea surface and look-alikes in RADARSAT-1 SAR data. The result showed that the new formula of the fractal box counting dimension was able to discriminate between oil spills and look-alike areas. The low wind area had the highest fractal dimension peak of 2.9, as compared to the oil slick and the surrounding rough sea. The maximum error standard deviation of the low wind area was 0.68 which performed with a 2.9 fractal dimension value.
The paper describes the uses of microfocus XRF to identify infected Basal Stem Rot (BSR) disease in Malaysian palm oil plants. Among symptoms of BSR are wilting of the leaves and plant malnutrition. The study involves determining the inorganic element content of normal and infected leaves. Si, Mo, Cl, K, Ca and Mn had been identified as the major elements. Their distribution was determined by constructing an elemental map of each of this element on the leaves. Line scan was also performed to look into changes on the element composition on a defined region. Quantitative analysis of Cl, Ca and K on the normal and infected leaves show that the infected leaves have lower Cl content and a higher Ca/K ratio than the normal leaves.
Compressive residual stress, induced by mechanical surface treatment, may relax during component
operation life, due to thermal or mechanical mechanism. Fatigue life prediction for the components which have residual stress will be misled and inaccurately predicted the phenomenon of residual stress relaxation is not considered. Despite putting an effort on incorporating the residual stress relaxation, the issues remain concerned with the technical challenge of measuring and quantifying
the magnitude of residual stress relaxation as well as redistribution during the loading cycling itself.
In this paper, the residual stress relaxation and its models were reviewed and discussed to picture
the best knowledge related to this topic, i.e. whether relaxation is a cause or an effect.
This studies are directed towards measuring the electrical conductivity of the (CuSe)1-xSex metal chalcogenide semi-conductor composites, with different stoichiometric compositions of Se (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8,1.0) in bulk form. The electrical conductivity measurement was carried out at room temperature, using the parallel plate technique. The (CuSe)1-xSex composites were prepared using solid state reaction, by varying the ratio of CuSe:Se, in the reaction mixture. The electrical conductivity of (CuSe)1-xSex was determined to be in the range of 1.17 x 10-8 to 1.02 x 10-1 S/cm. The finding indicated that the electrical conductivity value tended to decrease as the concentration of Se increased. The effect of the concentration of Se, on electrical conductivity of (CuSe)1-xSex composites, is discussed in this paper.
Iterative methods, particularly over-relaxation methods, are efficiently and frequently used to solve large systems of linear equations, because in the solutions of partial differential equations, these methods are applied to systems which are resulted from different iterative schemes to discrete equations. In this paper we formulate an accelerated over-relaxation (AOR) method with the quarter-sweep iterative scheme applied to the Poisson equation. To benchmark the new method we conducted experiments by comparing it with the previous AOR methods based on full- and half-sweep iterative schemes. The results of the experiments and the estimation of the computational complexity of the methods proved the superiority of the new method.
In this paper, systems of second-order boundary value problems (BVPs) are considered. The applicability of the homotopy-perturbation method (HPM) was extended to obtain exact solutions of the BVPs directly.
Many papers have been written on the synthesis of gold nanoparticles but very few included pictures of the process, and none of them used video to show the whole process of synthesis. This paper records the process of synthesis of gold nanoparticles using video clips. Every process from cleaning of glassware, an important step in the synthesis of metallic nanoparticles, to the dialysis process is shown. It also includes the preparation of aqua regia and the actual synthesis of gold nanoparticles. In some papers, the dialysis process was omitted, but in this paper, it is included to complete the whole process as it is being used for purification.
The efficiency of advanced oxidation processes (AOPs), enzymatic treatment and combined enzymatic/AOP sequences for the colour remediation of soda and chemimechanical pulp and paper mill effluent was investigated. The results indicated that under all circumstances, the AOP using ultraviolet irradiation (photo-Fenton) was more efficient in the degradation of effluent components in comparison with the dark reaction. It was found that both versatile peroxidase (VP) from Bjerkandera adusta and laccase from Trametes versicolor, as pure enzymes, decolorize the deep brown effluent to a clear light-yellow solution. In addition, it was found that in the laccase treatment, the decolorization rates of both effluents were enhanced in the presence of 2, 2'-azinobis (3-ethylbenzthiazoline-6-sulfonate), while in the case of VP, Mn(+2) decreased the efficiency of the decolorization treatment. The concomitant use of enzymes and AOPs imposes a considerable effect on the colour remediation of effluent samples.
Objective: This paper aimed to determine the prevalence of sleeping pills use among university students and its associated factors in Malaysia. Methods: This cross-sectional study was conducted in January 2010 among 200 Malaysia. The survey was conducted by distributing self-administered questionnaires. The questionnaire was developed based on the literature review. The students were chosen randomly using convenience sampling.
Results: A total of 200 university students participated in this study. The prevalence of using sleeping pills among university students is 7.5%. The majority of the participants were Malay 146 (73.0%), from urban area 169 (84.5%), from medical and health sciences background 101 (50.5%). This study showed that there is a significant relationship between using sleeping pills and depression (p= 0.03). There is also a significant relationship between
using sleeping pills and inducing sleep by reading (p=0.04). Conclusion: The prevalence of sleeping pills usage among university students is relatively high. This study showed that there is a significant relationship between using sleeping pills and depression.
The paper presents a simulation work conducted on the elastomer subjected to cyclic loads. A 3D finite element model of elastomer specimen, in accordance to ASTM D412, was developed using CATIA and ANSYS commercial finite element (FEM) packages. Fatigue life predicted from the simulation was compared with well-documented published data and it showed an acceptable agreement. Meanwhile, the simulated strain-life results are slightly lower than the experimental data. Several factors which potentially influenced the variations of the results were noted. Finally, some recommendations are offered at the end of this study to further improve the simulation
The Lembah Bujang archeological complex near Sungai Petani, Kedah consists of various structures constructed at different times and spread over a wide area. This paper reports on the thermoluminescence (TL) dating of one of these structures. The structure was found to be 350 ± 90 yrs old. This is very young as compared with other structures that are from the 4th to the 16th centuries. This structure is suspected to be remnant of a Muslim Mosque whereas the other structures were Hindu and Buddist temples.