Behavior, Switching Losses, and Efficiency Enhancement Potentials of 1200 V SiC Power Devices for Hard-Switched Power Converters

Semiconductor power devices are the major constituents of any power conversion system. These systems are faced by many circumscriptions due to the operating constraints of silicon (Si) based semiconductors under certain conditions. The emergence and persistence evolution of wide bandgap technology pledge to transcend the restrictions imposed by Si based semiconductors. This paper presents a thorough experimental study and assessment of the performance of three power devices: 1200 V SiC cascode, 1200 V SiC MOSFET, and 1200 V Si IGBT under the same hardware setup. The study aims to capture the major attributes for each power device toward determining their realistic potential applications. The switching performance of each power device is studied and reported. As the gate resistance is a crucial factor in a power device characterization, an extensive analysis of hard-switching losses under different separated turn-on and turnoff gate resistances is also performed and discussed. To appraise the fast switching capability, the switching dv/dts and di/dts are measured and analyzed for each power device. Furthermore, insights are provided about the dependency of switching energy losses on the power device current and blocking voltage. This paper also focuses on evaluating the operations and the performances of these power devices in a hard-switched dc-dc converter topology. While using of 1200 V SiC Schottky diode in the converter design with each power device, the high switching frequency operations and efficiency of the converter are reported and thoroughly explored. The SiC cascode exhibited superior performance when compared to the other two power devices. The results and analyses represent guidelines and prospects for designing advanced power conversion systems

The impact of micro credit on financial condition and socio-economic of women entrepreneurs in Bangladesh

Bangladesh is an innovator and home of abstracting micro credit program. It has taken few programs to alleviate poverty and enhance the quality of life among poor people. The main purpose of this research is to examine the impact of micro credit on financial condition as well as the socio-economic factors of women entrepreneurs in Bangladesh. Quantitative research method is adopted in this research to answer all the research objectives. Overall 230 women entrepreneurs have involved in the survey conducted in this research. Based on descriptive analyses, it is found that micro credit does not significantly affected the borrowers’ financial condition and some of the socio-economic variable including social security, health consciousness, entrepreneurship, and education. This research gives input to the micro finance institutions especially in Bangladesh to develop potential products to increase the borrowers’ financial and economic condition which at the same time alleviating poverty in the country. Finally, it is also benefits the Bangladesh government to enhance the existing policy on financial matters towards enhancing standard of living among the society in Bangladesh. Key words: micro credit, woman entrepreneurs, Bangladesh, financial institution

Millimetre-wave antennas and systems for the future 5G

Editorial of the special issue on Millimetre-Wave Antennas and Systems for the Future 5

Radar Cross-Section Formulation of a Shell-Shaped Projectile Using Modified PO Analysis

A physical optics based method is presented for calculation of monostatic Radar Cross-Section (RCS) of a shell-shaped projectile. The projectile is modeled using differential geometry. The paper presents a detailed analysis procedure for RCS formulation using physical optics (PO) method. The shortcomings of the PO method in predicting accurate surface current density near the shadow boundaries are highlighted. A Fourier transform-based filtering method is proposed to remove the discontinuities in the approximated surface current density. The modified current density is used to formulate the scattered field and RCS. Numerical results are presented comparing the proposed method with conventional PO method. The results are also compared with published results of similar objects and found to be in good agreement

The efficiency of Malaysian Islamic banks: Intermediation, production and operating approach

The Malaysian Islamic banking industry holds one of the top three market shares for global Islamic banking assets. Apparently, a dual banking system involving conventional and full-fledged Islamic banks are currently operating in Malaysia. The main objective of this study is to evaluate and compare the efficiency of conventional-owned Islamic banks and full-fledged Islamic banks using three banking approaches. To achieve this objective, information from the annual reports of 15 Islamic banks were utilised from 2011 to 2018. The findings provided mixed evidence subject to the different approaches of DEA methodology. Full-fledged Islamic banks outperformed conventionalowned Islamic banks in the intermediation approach, while conventional-owned Islamic banks outperformed in the production and operating approaches. The findings provide inputs for banks to increase their competency at the managerial level and for policymakers to sustain the growth momentum of the industry