43 research outputs found

    Behaviour of a High Frequency Parallel Quasi Resonant Inverter Fitted Induction Heater with Different Switching Frequencies

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    This paper investigates the behavior of a high frequency parallel quasiresonantinverter fitted domestic induction heater with different switching frequencies. The power semiconductor switch Insulated Gate Bipolar Junction Transistor (IGBT) is incorporated in this high frequency inverter that can operate under ZVS and ZCS conditions during the switching operations at certain switching frequency to reduce switching losses. The proposed induction heating system responds to three different switching frequencies with providing different results. An Insulated Gate Bipolar Junction Transistor (IGBT) provides better efficiency and faster switching operations. After the complete study of the proposed induction heating system at the selected switching frequencies, the results are compared and it is decided that most reliable, efficient and effective operations from the proposed induction heater can be obtained if the switching frequency is selected slightly above the resonant frequency of the tank circuit of the resonant inverter. The proposed scheme is analyzed using Power SystemSimulator (PSIM) environment

    A New Approach for Effective Reliability Management of Biomedical Equipment

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    Within the modern hospitals, an increasingly common problem is the efficient management of the maintenance of biomedical equipment. If effective management of medical equipment maintenance is applied, quality health services could be provided by reducing the downtime of medical equipment as well as by decreasing the recovery time for treatment of patients. Risk based maintenance strategy helps in designing an alternative methodology to minimize the risk by identifying the breakdown pattern and then increasing the reliability. The probability of failures that obstruct the reliability can be influenced by some technical, administrative or management actions. The proposed study is based on the analysis of reliability and availability for maintenance planning on the basis of risk index and fault tree analysis. Maintenance of equipment is prioritized based on the risk which helps in reducing the overall risk of the hospital. Fault tree diagram is also developed to understand the actual scenario where highest priority or risk events are sequentially arranged. Failure probability for different biomedical equipment has been established by applying statistical method. It has been observed that Magnetic Resonance Imaging has the lowest risk index while X-Ray has the highest risk index. Also, maintenance planning has been suggested based on the reduction of risk factor to meet the acceptable criteria and reduce the probability of failure. This approach depicts that reliability of equipment is increased after implementation of maintenance planning proposed which contributes to the availability of the equipment as well as its safe operation

    A new approach for effective productivity management of newspaper printing press

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    Within the modern commercial printing press, a common problem is the ef-ficient management of the maintenance of different machines of newspaper printing press. If Effective Maintenance Management is applied, productivity of the machines can be increased by reducing breakdown time of the ma-chine. Productivity Management is an organizational framework that helps machines to improve productivity. Productivity of a machine is dependent on the failure probability which can be controlled by technical and management actions. The present investigation is established by the analysis of productivi-ty, effectiveness and failure probability on the basis of Pareto Analysis. Pareto chart is also developed to understand the actual scenario where highest prior-ity events are sequentially arranged. It has been observed that the web-offset printing machine has the highest productivity and effectiveness with less failure probability while the exposure unit has the highest failure probability having low productivity and effectiveness. Based on the reduction of proba-bility of failure to meet the acceptable criteria, further maintenance planning can be suggested. This approach confirms that productivity and effectivity of the machines of newspaper printing press can be increased by considering consequences of the machines and their corresponding failure assessments

    Application of radio frequency based digital thermometer for real-time monitoring of dairy cattle rectal temperature

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    Aim: Dairy cattle health monitoring program becomes vital for detecting the febrile conditions to prevent the outbreak of the animal diseases as well as ensuring the fitness of the animals that are directly affecting the health of the consumers. The aim of this study was to validate real-time rectal temperature (RT) data of radio frequency based digital (RFD) thermometer with RT data of mercury bulb (MB) thermometer in dairy cattle. Materials and Methods: Two experiments were conducted. In experiment I, six female Jersey crossbred cattle with a mean (±standard error of the mean) body weight of 534.83±13.90 kg at the age of 12±0.52 years were used to record RT for 2 h on empty stomach and 2 h after feeding at 0, 30, 60, 90, and 120 min using a RFD thermometer as well as a MB thermometer. In experiment II, six female Jersey crossbred cattle were further used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90, and 120 min. Two-way repeated measures analysis of variance with post hoc comparisons by Bonferroni test was done. Results: Real-time RT data recorded by RFD thermometer as well as MB thermometer did not differ (p>0.05) before and after feeding/exercise. An increase (p<0.05) in RT after feeding/exercise in experimental crossbred cattle was recorded by both RFD thermometer and MB thermometer. Conclusion: The results obtained in the present study suggest that the body temperature recordings from RFD thermometer would be acceptable and thus RFD thermometer could work well for monitoring real-time RT in cattle
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