204 research outputs found

    A Review of Communication Protocols for Intelligent Remote Terminal Unit Development

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    This paper reviewed all the possible interfacing communication protocols for remote terminal unit (RTU). Supervisory Control and Data Acquisition (SCADA) system is a central station that can communicate with other network using the protocol. Fundamentally, the architectures of all networks are based on the seven layers of open system interconnection (OSI) and International Standard Organization (ISO). The objective of designing the protocols is to check the status of all the input and output field devices and send the report according to that status. The corresponding protocol and communication parameters between the connecting devices will be included in designing a complex SCADA system. The available protocols to develop the communication of RTU are Modbus/ASCII, distributed network protocol (DNP3), controller area network (CAN), International Electro-technical Commission (IEC 60870), and transmission control protocol/internet protocol (TCP/IP)

    Cloud-To-Ground Lightning Flashes Under The Influence Of Pollution In Malaysia And Some Countries

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    The effect of air pollution produced from world war, industrial activities and transportation clearly can change the earth ecology system such as the atmospheric conditions. Base on few studies reported from by researcher in USA, Brazil, Spain and South Korea researcher have proven that the pollution effect can enhance the activity of lightning. Those information above motivate Advanced Multidisciplinary System Technology researcher in UTeM to report the cloud-to-ground lightning flashes in Malaysia the influence of pollution. Particulate Matter (PM10) and Sulfur Dioxide (SO2) concentration were used as gross indicator of Cloud Condensation Nuclei (CCN) and examined in relation to the urban increase in CG lightning activity. PM10 concentration recorded in Subang, Ipoh and Bayan Lepas were 51, 50 and 49μgm/m³ respectively. Meanwhile, SO2 concentration recorded were 8, 7.9, 7.7μgm/m³. The three urban areas have average number of CG lightning flashes of 200, 197 and 184. An analysis related number of CG flashes against pollutants show positive correlation in Malaysia with reading of 0.94. This indicates PM10 and SO2 concentration have high influential factor in enhancement of CG lightning activity in Malaysia

    Poor sitting posture and a heavy schoolbag as contributors to musculoskeletal pain in children: an ergonomic school education intervention program

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    Objectives: The purpose of this study was to evaluate a multidisciplinary, interventional, ergonomic education program designed to reduce the risk of musculoskeletal problems by reducing schoolbag weight and correcting poor sitting posture. Methods: Data were collected twice before and twice following intervention using the Standardized Nordic Body Map Questionnaire, a rapid upper limb assessment for posture evaluation, and schoolbag weight measurement in children aged 8 and 11 years attending two schools within the central region of Malaysia. Results: Students who received the ergonomic intervention reported significant improvements in their sitting posture in a classroom environment and reduction of schoolbag weight as compared with the controls. Conclusion: A single-session, early intervention, group ergonomics education program for children aged 8 and 11 years is appropriate and effective, and should be considered as a strategy to reduce musculoskeletal pain among schoolchildren in this age group

    Development of an indoor air quality checklist for risk assessment of indoor air pollutants by semiquantitative score in nonindustrial workplaces

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    Background: To meet the current diversified health needs in workplaces, especially in nonindustrial workplaces in developing countries, an indoor air quality (IAQ) component of a participatory occupational safety and health survey should be included. Objectives: The purpose of this study was to evaluate and suggest a multidisciplinary, integrated IAQ checklist for evaluating the health risk of building occupants. This IAQ checklist proposed to support employers, workers, and assessors in understanding a wide range of important elements in the indoor air environment to promote awareness in nonindustrial workplaces. Methods: The general structure of and specific items in the IAQ checklist were discussed in a focus group meeting with IAQ assessors based upon the result of a literature review, previous industrial code of practice, and previous interviews with company employers and workers. Results: For practicality and validity, several sessions were held to elicit the opinions of company members, and, as a result, modifications were made. The newly developed IAQ checklist was finally formulated, consisting of seven core areas, nine technical areas, and 71 essential items. Each item was linked to a suitable section in the Industry Code of Practice on Indoor Air Quality published by the Department of Occupational Safety and Health. Conclusion: Combined usage of an IAQ checklist with the information from the Industry Code of Practice on Indoor Air Quality would provide easily comprehensible information and practical support. Intervention and evaluation studies using this newly developed IAQ checklist will clarify the effectiveness of a new approach in evaluating the risk of indoor air pollutants in the workplace

    Bromocarbons in the tropical coastal and open ocean atmosphere during the Prime Expedition Scientific Cruise 2009 (PESC 09)

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    Atmospheric concentrations of very short-lived species (VSLS) bromocarbons, including CHBr3, CH2Br2, CHCl2Br, CHClBr2, and CH2BrCl, were measured in the Strait of Malacca and the South China and Sulu–Sulawesi seas during a two-month research cruise in June–July 2009. The highest bromocarbon concentrations were found in the Strait of Malacca, with smaller enhancements in coastal regions of northern Borneo. CHBr3 was the most abundant bromocarbon, ranging from 5.2 pmol mol−1 in the Strait of Malacca to 0.94 pmol mol−1 over the open ocean. Other bromocarbons showed lower concentrations, in the range of 0.8–1.3 pmol mol−1 for CH2Br2, 0.1–0.5 pmol mol−1 for CHCl2Br, and 0.1–0.4 pmol mol−1 for CHClBr2. There was no significant correlation between bromocarbons and in situ chlorophyll a, but positive correlations with both MODIS and SeaWiFS satellite chlorophyll a. Together, the shortlived bromocarbons contribute an average of 8.9 pmol mol−1 (range 5.2–21.4 pmol mol−1) to tropospheric bromine loading, which is similar to that found in previous studies from global sampling networks (Montzka et al., 2011). Statistical tests showed strong Spearman correlations between brominated compounds, suggesting a common source. Log–log plots of CHBr3/CH2Br2 versus CHBr2Cl/CH2Br2 show that both chemical reactions and dilution into the background atmosphere contribute to the composition of these halocarbons at each sampling point. We have used the correlation to make a crude estimate of the regional emissions of CHBr3 and to derive a value of 32 Gg yr−1 for the Southeast (SE) Asian region (10◦ N–20◦ S, 90–150◦ E). Finally, we note that satellite-derived chlorophyll a (chl a) products do not always agree well with in situ measurements, particularly in coastal regions of high turbidity, meaning that satellite chl a may not always be a good proxy for marine productivity

    The Growth Of Aln Single Layer On Sapphire At Low Pressure Using Metalorganic Chemical Vapor Deposition (MOCVD)

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    In this work, AlN single layer has been successfully grown on c-plane sapphire using metalorganic chemical vapor deposition (MOCVD) at low reactor pressure. The effects of growth temperature, ammonia (NH3) flux and trimethylaluminum (TMAl) flux towards AlN growth were investigated. It was noted that the reaction between NH3 and TMAl has affected the growth rate across the growth temperature. Field emission scanning electron microscopy (FESEM) equipped with Energy-dispersive X-ray (EDX) have revealed the formation of AlN single layer on the sapphire substrate and elemental composition of the layer, respectively. The dependence of growth rate on growth temperature, TMAl flux and NH3 flux was observed. It could be related to the occurrence of parasitic reaction as a result of theunintentional formation of AlON composition in the AlN layer. A relationship was drawn, whereby an increase in TMAl flux and decrease in NH3 flux would lead to an increase in the AlN growth. In addition, a drastic increase in the AlN growth was observed at high growth temperature, which was more than 1000°C. Further characterization was carried out using atomic force microscopy (AFM) and phase analysis using X-ray diffraction system (XRD)

    Bridging the data gaps in the epidemiology of hepatitis C virus infection in Malaysia using multi-parameter evidence synthesis

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    BACKGROUND: Collecting adequate information on key epidemiological indicators is a prerequisite to informing a public health response to reduce the impact of hepatitis C virus (HCV) infection in Malaysia. Our goal was to overcome the acute data shortage typical of low/middle income countries using statistical modelling to estimate the national HCV prevalence and the distribution over transmission pathways as of the end of 2009. METHODS: Multi-parameter evidence synthesis methods were applied to combine all available relevant data sources - both direct and indirect - that inform the epidemiological parameters of interest. RESULTS: An estimated 454,000 (95% credible interval [CrI]: 392,000 to 535,000) HCV antibody-positive individuals were living in Malaysia in 2009; this represents 2.5% (95% CrI: 2.2-3.0%) of the population aged 15-64 years. Among males of Malay ethnicity, for 77% (95% CrI: 69-85%) the route of probable transmission was active or a previous history of injecting drugs. The corresponding proportions were smaller for male Chinese and Indian/other ethnic groups (40% and 71%, respectively). The estimated prevalence in females of all ethnicities was 1% (95% CrI: 0.6 to 1.4%); 92% (95% CrI: 88 to 95%) of infections were attributable to non-drug injecting routes of transmission. CONCLUSIONS: The prevalent number of persons living with HCV infection in Malaysia is estimated to be very high. Low/middle income countries often lack a comprehensive evidence base; however, evidence synthesis methods can assist in filling the data gaps required for the development of effective policy to address the future public health and economic burden due to HCV. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-014-0564-6) contains supplementary material, which is available to authorized users

    Permeance Based Algorithm For Computation Of Flux Linkage Characteristics Of Non-Linear 6/4 Switched Reluctance Motor (SRM)

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    The concept of permeance is used in the analysis of flux linkage of 6/4 SRM. The aim of this paper is to develop an efficient algorithm exploiting the nonlinear feature of the 6/4 SRM using the aforementioned concept of permeance. The first step is to generate the relevant equations related to permeances of the 6/4 SRM under study. The 6/4 SRM’s magnetization curve is then derived from the summation of mmf drops at various blocks representing the motor. The air gap permeances are derived at various angles and 3-D leakage effects are taken into account. These permeances are used for the mmf drop computation. The algorithm is capable of efficiently computing mmf drop at every block to consequently yield a complete accurate nonlinear flux linkage feature of the 6/4 switched reluctance motor. In this way, the capability of the SRM to produce the expected four times the specific output torque due to operation in high saturation region compared to an equivalent induction motor as special the attribute of the SRM is demonstrated

    Is Evaluation of Hepatitis A Immunity Required or Not?

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    Hepatitis A virus (HAV) infection is one of the most common causes of acute hepatitis and it is a serious health problem worldwide. HAV infection is a vaccine preventable disease that can produce the lifelong immunity seen in many developed countries with the vaccination schedule administered to children; however this vaccine is not used in developing countries at the present time. Improvements in food and water hygiene have caused a displacement of hepatitis A infection from children to adults which has increased mortality rates. Therefore evaluation of HAV immunity levels can help health authorities develop polices for prophylaxis especially in developing countries

    Helicobacter pylori cagA gene variants in Malaysians of different ethnicity

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    We have defined DNA repeat variability in the 3′-terminus of the cagA gene of Helicobacter pylori strains from Malaysian patients of different ethnicities. We identified different alleles based on the EPIYA repeats. cagA types A-B-D and A-B-B-D are more similar to the sequence of Japanese strains, whereas cagA types A-B-C, A-B-C-C, A-B and A-C displayed similarity to strain 26695 sequences. A significant association was found between cagA genotypes and patients’ ethnicity, with cagA type A-B-D being predominantly isolated from Chinese patients and cagA type A-B-C from Malays and Indians. Our data further corroborate the possibility that variant biological activity of CagA may affect the host specificity and/or pathogenicity of H. pylori
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