Chittagong University of Engineering & Technology

About: Chittagong University of Engineering & Technology is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Renewable energy & Dielectric. The organization has 1200 authors who have published 1444 publications receiving 10418 citations. The organization is also known as: Engineering College, Chittagong & Bangladesh Institute of Technology, Chittagong.

Modeling of groundwater level changes in an urban area

Abstract: Groundwater level changes, mostly depletion, are widespread around the world due to the high population and industrial growth. Numerical models can provide relevant information in a data scares location and thus could be great means to save both money and time. In this study, an attempt was made to analyze changes in the groundwater level using the widely accepted MODFLOW-2005 model. This study covered 22 wards among the 41 wards of Chittagong city in Bangladesh and the simulation was run for the year 2009–2016. Compare to the observed water heads, the simulated model could reasonably predict water heads with a residual of less than 10%. From 2009 to 2016, the model outcome showed a depletion rate of about 4.75 m/year in the central part of the city. Finally, the model was run for the year 2020 to predict the future condition of the water head. From this, there are five wards in the central part facing a serious groundwater lowering problem. Thus, to save this natural resource more comprehensive strategies as well as ground extraction regulations should be made. And in this context, this study will provide an overview of this urgent issue in this city.

Design of highly stable and efficient molybdenum telluride PV cells with arsenic telluride BSF

Abstract: For high efficiency and better thermal stability, Molybdenum Telluride (MoTe 2 ) is remarkable as potential photovoltaic (PV) cell. AMPS (Analysis of Microelectronic and Photonic Structures) simulator is used to investigate the cell performance parameters to design the highly efficient ultra-thin MoTe 2 PV cell. In this research work, it has been explored that the cell conversion efficiency of MoTe 2 PV cell is improved with the insertion of Arsenic Telluride (As 2 Te 3 ) as back surface field (BSF) above the back contact metal. The highest conversion efficiency of 25.08% was found for As 2 Te 3 BSF with only 0.9 μm of absorber layer whereas it was 17.06% for no BSF with 1 μm thickness of absorber layer. The thermal stability of MoTe 2 PV cell with As 2 Te 3 BSF showed better stability also.

Structural and Optical Properties of RF-Sputtered CdTe Thin Films Grown on CdS:O/CdS Bilayers

Abstract: In this work, we report the structural and optical properties of CdTe thin films on oxygenated Cadmium Sulfide (CdS:O)/Cadmium sulfide(CdS) bilayer using RF magnetron sputtering for different substrate temperatures ( 150, 200, 250, 300 and 350 °C) in Argon ambient. The XRD spectra reveal the polycrystalline nature of all the CdTe thin films with preferential cubic orientation along (111) direction. Raman Spectra show a dominant peak at 163.5 cm -1  and its overtone at 328.7 cm -1  which corresponded to the longitudinal optical (LO) phonon of CdTe. The SEM microscopy exhibits the uniform growth of CdTe films onto the entire glass substrate. The optical transmission of the CdTe films begin at the edge of 800 nm wavelength and showed interference fringe in the transmission spectra. The thickness of the deposited films and the optical constants were calculated from the fringe pattern. The thicknesses of the CdTe films are found to be increasing from 2.34 I¼m to 2.82 I¼m with increasing the substrate temperature i.e. from 150 to 250°C. Thereafter, the CdTe film thickness decreased to 2.24 I¼m while the temperature increased further up to 350°C. The optical bandgap of the deposited CdTe films follows an increasing trend of 1.46 eV to 152 eV with the increase of substrate temperature 150 to 250°C after that the bandgap decrease to 1.50 for 350°C. Hence the obtained structural and optical properties suggest that the deposited CdTe films can be used as a suitable absorber layer for the thin film-based solar cells.

Effect of land-use intensity on surface temperature: A study on Chittagong city corporation area

Abstract: Heat and temperature is on the news of the air in the today's world. High temperatures in urban areas have a direct impact on human health and are associated with heat related problems and excess summer deaths. This study is carried out to know the trend of land surface temperature and assess the impact of land use intensity on temperature in the Chittagong City Corporation Area, Bangladesh. A general linear model was used to estimate surface temperatures using Landsat TM, ETM+ and OLI_TIRS are used in the year 1991, 2003 and 2015 the months of May. Land use and its environmental effects can be quantitatively defined by land-use intensity. In this study, land-use intensity metric was improved using a geographic mapping method. The results revealed the temperature increased when the land-use intensity increased via a hierarchical transition owing to forest land reductions of 26.25%, respectively; built-up land increased by 48.45%. The temperature increase was driven more by the external environmental degrades than by land use intensity changes. The temperature response to land-use intensity changes was more sensitive in low altitude areas than in high altitude areas.