http://dspace.ewubd.edu:8080/handle/123456789/1347 2026-04-05T23:51:21Z http://dspace.ewubd.edu:8080/handle/2525/2737 Impact of Particulate Matter Emission from Barapukuria Coal-Fired Thermal Power Plant on Premature Human Mortality Khan, Musharrat; Tuli, Naheed Nazneen; Ahmed, Sheikh Imran Uddin This study is carried out to assess the impact of PM2.5 emission from Barapukuria Coal-Fired Thermal Power Plant on human health in the adjoining areas. This is the first investigation of its kind. As data for actual concentrations of PM2.5 at various locations around Barapukuria are not available, we have adopted the PM2.5 emission rate data from coal-fired power plants of India and China for Barapukuria Coal-Fired Thermal Power Plant. Using this adopted emission rate of PM2.5, we have calculated the concentrations of PM2.5 in the exposed areas using Gaussian Plume Dispersion Equation. As the first attempt of this kind of work, we have estimated annual average concentrations of PM2.5 in 11 upazillas along the annual average wind direction (south-east) from Barapukuria. These upazillas fall within 160km from Barapukuria along south-east direction. The calculated results show that around 2.3 million people are exposed to significant concentrations of PM2.5. To accommodate the uncertainty of emission rates, we have calculated the impact of PM2.5 emission from the power plant for both the best case and the worst case scenarios. We have calculated intake fraction (iF) for both the best case and the worst case emission rates, which for both cases is found to be 2.18×104. We have also calculated the relative risk (RR). The calculated values of RR for the best case and the worst case are 1.0226 and 1.0610, respectively. We have theoretically calculated the expected number of premature deaths due to PM2.5 exposure. The calculated values for the best case and the worst case scenarios show that on an average 292 to 760 more people will die due to PM2.5 exposure every year. This preliminary study done under the mentioned limitations reveals that there is a potential risk of human health hazard due to PM2.5 emission from Barapukuria Coal-Fired Thermal Power Plant. This thesis submitted in partial fulfillment of the requirements for the degree of B.Sc in Electrical and Electronic Engineering of East West University, Dhaka, Bangladesh. 0012-01-01T00:00:00Z http://dspace.ewubd.edu:8080/handle/2525/2732 Simulation of High Efficiency Hit Solar Cell Bulbul, Jannate; Moyna, Razia Sultana HIT (Heterojunction with Intrinsic Thin layer) solar cells have attracted growing attention among all Si based PV technologies because of their prospect of further improvisation of efficiency and cost reduction. A high efficiency a-Si:H (n)/a-Si:H (i)/c-Si (p)/uc-Si (p+) HIT solar cell is simulated and studied here. AFORS-HET simulation tool is used for simulation purpose. In this thesis, the I-V characteristics and energy band diagram of HIT cell are analyzed. The impacts of the variations of emitter, intrinsic layer and substrate thicknesses on the photovoltaic characteristics of solar cell are discussed. We have varied the emitter, the intrinsic layer and the substrate thicknesses and observed that only the substrate thickness variation affects the conversion efficiency significantly. The increase of substrate thickness leads to increase of efficiency. We have simulated our HIT structure using optimized values of thicknesses. With the optimized parameters combination, this HIT cell reaches a high performance with conversion efficiency (η) of 24.25%, fill factor (FF) of 85.73%, open circuit voltage (VOC) of 783.1 mV, and short circuit current density (JSC) of 36.12 mA/cm2. This thesis submitted in partial fulfillment of the requirements for the degree of B.Sc in Electrical and Electronic Engineering of East West University, Dhaka, Bangladesh. 0012-01-01T00:00:00Z http://dspace.ewubd.edu:8080/handle/123456789/2224 A Semi-Analytical Model for III-V Semiconductor Quantum Well Field Effect Transistors Islam, Md. Samiul; Rahman, Md. Shajedur As conventional silicon transistors are reaching physical size limit, new materials and device structures are being assessed. Among the different materials proposed to continue the microelectronics revolution, III-V semiconductor technology is attracting attention due to its unique optical and electronic properties. As it has been well known for decades, the electron mobility of III-V compounds is much higher than the corresponding one in silicon. There has been tremendous progress made recently in the research of novel electronics for future applications [2]. Silicon has been used as the main material in the Integrated Circuits (IC). The device scaling is an important issue in semiconductor IC industries. Recently this continual device downsizing is becoming increasingly difficult because of both fundamental limitations and practical considerations as the transistor dimensions are approaching the deca-nanometer range [1]. As a result to attain this limiting size and high performance, high mobility channel materials like Ge and III-V materials have joined in present time. Recently, studies have been carried out on III-V compound semiconductors as potential channel materials for MOSFETs This thesis submitted in partial fulfillment of the requirements for the degree of B.Sc in Electrical and Electronic Engineering of East West University, Dhaka, Bangladesh. 0004-01-01T00:00:00Z http://dspace.ewubd.edu:8080/handle/123456789/1408 Substation Voltage Regulators & backup Power Suplies at Navana Electronics LTD Rishad, S. A. N. Shams During my internship, I had gathered practical knowledge of Substations, Voltage Regulators, and Backup Power Systems. I had training on the basic theory behind every product, how the designs are done, how the manufacturing is performed, and finally how the final products are tested in the Quality Control process. These experiences are the content of this report. I have obtained a comprehensive overview of how a power is distributed from grid to the household over the substation. I have achieved hands on experience on Distribution Transformers, Low Tension (LT) & High Tension (HT) Switchgears, Power Factor Improvement (PFI) Plant and Distribution Board. In the process, I have also learnt the use of various types of circuit breakers and protective relays. Apart from substation, I had training on two types of voltage regulators- Auto Voltage Regulator (AVR) and Industrial Voltage Stabilizer (IVS). These two products stabilize supply voltage and ensure safety of the apparatus. I have written my experiences on two types of Backup Power Systems- Instantaneous Power System (IPS) and Uninterruptible Power Supply (UPS). These two products deliver emergency power in the event of power outage from the grid. Sections written on these nine products contain my learning and experience on theories, designs, manufacturing, and quality control process. This thesis submitted in partial fulfillment of the requirements for the degree of B.Sc in Electrical and Electronic Engineering of East West University, Dhaka, Bangladesh. 0007-01-01T00:00:00Z