34 research outputs found

    Decompression illness secondary to occupational diving : recommended management based current legistation and practice in Malaysia.

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    Occupational divers are exposed to hazards which contribute to the risk of developing decompression illnesses (DCI). DCI consists of Type I decompression sickness (DCS), Type II DCS and arterial gas embolism (AGE), developed from formation of bubbles in the tissues or circulation as a result of inadequate elimination of inert gas (nitrogen) after a dive. In Malaysia, DCI is one of the significant contributions to mortality and permanent residual morbidity in diving accidents. This is a case of a diver who suffered from Type II DCS with neurological complications due to an occupational diving activity. This article mentions the clinical management of the case and makes several recommendations based on current legislations and practise implemented in Malaysia in order to educate medical and health practitioners on the current management of DCI from the occupational perspective. By following these recommendations, hopefully diving accidents mainly DCI and its sequalae among occupational divers can be minimized and prevented, while divers who become injured receive the proper compensation for their disabilities

    Diving accidents treated at a military hospital-based recompression chamber facility in Peninsular Malaysia.

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    This paper describes the pattern of diving accidents treated in a military hospital-based recompression chamber facility in Peninsular Malaysia. A retrospective study was carried out to utilize secondary data from the respective hospital medical records from 1st January 1996 to 31st December 2004. A total of 179 cases categorized as diving accidents received treatment with an average of 20 cases per year. Out of 179 cases, 96.3% (n=173) received recompression treatment. Majority were males (93.3%), civilians (87.2%) and non-Malaysian citizens (59.2%). Commercial diving activities contributed the highest percentage of diving accidents (48.0%), followed by recreational (39.2%) and military (12.8%). Diving accidents due to commercial diving (n=86) were mainly contributed by underwater logging activities (87.2%). The most common cases sustained were decompression illness (DCI) (96.1%). Underwater logging and recreational diving activities which contribute to a significant number of diving accidents must be closely monitored. Notification, centralised data registration, medical surveillance as well as legislations related to diving activities in Malaysia are essential to ensure adequate monitoring of diving accidents in the future

    The molecular phylogenetic signature of Bali cattle revealed by maternal and paternal markers

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    Bali cattle is a domestic cattle breed that can be found in Malaysia. It is a domestic cattle that was purely derived from a domestication event in Banteng (Bos javanicus) around 3,500 BC in Indonesia. This research was conducted to portray the phylogenetic relationships of the Bali cattle with other cattle species in Malaysia based on maternal and paternal lineage. We analyzed the cytochrome c oxidase I (COI) mitochondrial gene and SRY of Y chromosome obtained from five species of the Bos genus (B. javanicus, Bos gaurus, Bos indicus, Bos taurus, and Bos grunniens). The water buffalo (Bubalus bubalis) was used as an outgroup. The phylogenetic relationships were observed by employing several algorithms: Neighbor-Joining (PAUP version 4.0), Maximum parsimony (PAUP version 4.0) and Bayesian inference (MrBayes 3.1). Results from the maternal data showed that the Bali cattle formed a monophyletic clade, and together with the B. gaurus clade formed a wild cattle clade. Results were supported by high bootstrap and posterior probability values together with genetic distance data. For the paternal lineage, the sequence variation is low (with parsimony informative characters: 2/660) resulting an unresolved Neighbor-Joining tree. However, Bali cattle and other domestic cattle appear in two monophyletic clades distinct from yak, gaur and selembu. This study expresses the potential of the COI gene in portraying the phylogenetic relationships between several Bos species which is important for conservation efforts especially in decision making since cattle is highly bred and hybrid breeds are often formed. Genetic conservation for this high quality beef cattle breed is important by maintaining its genetic characters to prevent extinction or even decreased the genetic quality

    Subchronic toxicity, immunoregulation and anti-breast tumor effect of Nordamnacantal, an anthraquinone extracted from the stems of Morinda citrifolia L.

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    Background: Morinda citrifolia L. that was reported with immunomodulating and cytotoxic effects has been traditionally used to treat multiple illnesses including cancer. An anthraquinone derived from fruits of Morinda citrifolia L., nordamnacanthal, is a promising agent possessing several in vitro biological activities. However, the in vivo anti-tumor effects and the safety profile of nordamnacanthal are yet to be evaluated. Methods: In vitro cytotoxicity of nordamnacanthal was tested using MTT, cell cycle and Annexin V/PI assays on human MCF-7 and MDA-MB231 breast cancer cells. Mice were orally fed with nordamnacanthal daily for 28 days for oral subchronic toxicity study. Then, the in vivo anti-tumor effect was evaluated on 4T1 murine cancer cells-challenged mice. Changes of tumor size and immune parameters were evaluated on the untreated and nordamnacanthal treated mice. Results: Nordamnacanthal was found to possess cytotoxic effects on MDA-MB231, MCF-7 and 4T1 cells in vitro. Moreover, based on the cell cycle and Annexin V results, nordamnacanthal managed to induce cell death in both MDA-MB231 and MCF-7 cells. Additionally, no mortality, signs of toxicity and changes of serum liver profile were observed in nordamnacanthal treated mice in the subchronic toxicity study. Furthermore, 50 mg/kg body weight of nordamncanthal successfully delayed the progression of 4T1 tumors in Balb/C mice after 28 days of treatment. Treatment with nordamnacanthal was also able to increase tumor immunity as evidenced by the immunophenotyping of the spleen and YAC-1 cytotoxicity assays. Conclusion: Nordamnacanthal managed to inhibit the growth and induce cell death in MDA-MB231 and MCF-7 cell lines in vitro and cease the tumor progression of 4T1 cells in vivo. Overall, nordamnacanthal holds interesting anti-cancer properties that can be further explored

    Adaptive Mho distance relay for combined transmission line: An optimization technique for charging current compensation

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    The combined transmission system is expanding due to beatification and safety considerations and enhanced reliability in the distribution and transmission systems. It is expected to improve distance relay operation in presence of combined transmission system. Distance relay with Mho characteristics is simulated to mitigate the charging current effect of combined system with significant part of underground cable. The combined system is modelled mathematically based on the equivalent pi model to increase the accuracy. The distance relay is simulated based on the mathematical equation. The rate of charging current is compensation is extracted for single line to ground, line to line to ground and three-phase faults. The charging current compensation rate is extracted by direct search and the feasible solution is extracted by Utopia point approach. The findings show the fault with high resistance faces distance relay to mal-operation. The compensation of charging current can significantly mitigate the mis-operation rate of Mho distance relay. Due to the zone characteristics is constant, the selected value of charging current compensation required to have minimum overreach and underreach rates. By injecting the optimal charging current compensation rate at the relay point, the operation of Mho relay bounces to more than 99.5% for combined transmission system

    Load shedding scheme in large pulp mill by using analytic hierarchy process

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    Pulp mill is one of the heavy industries that consumes large amount of electricity in its production. In particular, the breakdown of the generator would cause other generators to be overloaded. Thus, load shedding scheme is the best way in handling such condition. Selected load will be shed under this scheme in order to protect the generators from being damaged. In the meantime, the subsequence loads will be shed until the generators are sufficient to provide the power to other loads. In order to determine the sequences of load shedding scheme, analytic hierarchy process (AHP) is introduced. Analytic Hierarchy Process is one of the multi-criteria decision making methods. By using this method, the priority of the load can be determined. This paper presents the theory of the alternative methods to choose the load priority in load shedding scheme for a large pulp mill

    Process modelling of combined degumming and bleaching in palm oil refining using artificial neural network

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    Combined degumming and bleaching is the first stage of processing in a modern physical refining plant. In the current practice, the amount of phosphoric acid (degumming agent) and bleaching earth (bleaching agent) added during this process is usually fixed within a certain range. There is no system that can estimate the right amount of chemicals to be added in accordance with the quality of crude palm oil (CPO) used. The use of an Artificial Neural Network (ANN) for an improved operating procedure was explored in this process. A feed forward neural network was designed using a back-propagation training algorithm. The optimum network for the response factor of phosphoric acid and bleaching earth dosages prediction were selected from topologies with the smallest validation error. Comparisons of ANN predicted results with industrial practice were made. It is proven in this study that ANN can be effectively used to determine the phosphoric acid and bleaching earth dosages for the combined degumming and bleaching process. In fact, ANN gives much more precise required dosages depending on the quality of the CPO used as feedstock. Therefore, the combined degumming and bleaching process can be further optimised with savings in cost and time through the use of ANN

    Feasibility study of wave energy potential in southern coasts of Caspian Sea in Iran

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    Wave energy as a predictable renewable energy, can be directly captured from surface wave, which has a significant power. Although the application of wave energy in recent years is rapidly increased all over the world especially in Europe, but there is a lack of research in this field in some developing countries. Hence, in this study a new research about potential of wave in Southern border of Caspian Sea in Iran is performed. Moreover, the climate effect that has contributed to the increasing wave power is also investigated. The results show that Mazandaran seashore in north of Iran has a proper potential for extracting electricity from sea wave. Furthermore, based on a comparison of established wave energy converters, Wave Dragoon is a suitable converter for the study case

    Observability of synchronous generators' parameters in its dynamic performance

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    Observability of synchronous generators' dynamic parameters has significant contribution in the design of the parameter identification method of the generators. Subsequently, it has a serious impact on the accuracy level of the transient stability analysis of electrical power systems. This work is devoted to the observability analysis of these parameters in the generator dynamic performance. It has been done by introducing a sensitivity analysis concept and provides a ranking system for the generator measurements, namely the operating data, related to the observability of each parameter. It has been done using least square based indicator. These measurements consider the generator output variables such as active power, reactive power, rotor speed, rotor angle, terminal voltage and armature current. This evaluation is developed for various types of disturbances normally occur in operation of the generators, using a single-generator infinite-bus standard test system. The above ranking is performed for each type disturbance separately. These events are categorized due to change in excitation voltage, change in prime-mover torque and fault in the connected grid
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