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: Computer science & Renewable energy. 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.

Design of a dual circular polarization microstrip patch array antenna

Abstract: Design of a microstrip array antenna to achieve dual circular polarization is proposed in this paper. The proposed antenna is a 2×2 array antenna where each patch element is circularly polarized. The feed network has microstrip lines, cross slot lines and air-bridges. The array antenna can excite both right-hand circular polarization (RHCP) and left-hand circular polarization (LHCP) without using any 90° hybrid circuit or PIN diode. “Both-sided MIC Technology” is used to design the feed network as it provides flexibility to place several types of transmission lines on both sides of the dielectric substrate. The design frequency of the proposed array antenna is 10 GHz. The simulated return loss exhibits an impedance bandwidth of greater than 5% and the 3-dB axial ratio bandwidths for both RHCP and LHCP are approximately 1.39%. The structure and the basic operation along with the simulation results of the proposed dual circularly polarized array antenna are demonstrated in this paper.

High efficient and stable ultra-thin CdTe solar cell with a potential Copper Telluride BSF

Abstract: CdTe is recognized as leading solar cell for having the feature of low cost, high efficiency and better cell stability. The BSF strategy below the absorber layer of CdTe solar cell showed the possibility of higher power conversion efficiency. In this research work, Copper Telluride (Cu 2 Te) BSF is used to explore the hidden potentiality of CdTe solar cell at ultra-thin level. It was investigated that the addition of Cu 2 Te BSF significantly enhanced the cell conversion efficiency to 22.51% (Jsc = 24.26 mA/cm2, FF = 0.875, Voc = 1.06 V) with only 0.8 µm of absorber layer in CdTe solar cell. In addition, the cell stability was improved by adding Cu 2 Te BSF layer in CdTe solar cell and the temperature co-efficient (TC) was 0.16%/°C which indicated better thermal stability.

Design of a circular polarization array antenna with dual-orthogonal feed circuit

Abstract: In this paper, the design of a circularly polarized array antenna at 10 GHz frequency is presented. The proposed antenna consists of a 1×2 array antenna with feed circuit. To realize circular polarization, dual-orthogonal feed circuit is used that excites two orthogonal modes with equal amplitude but quadrature in phase. Feed circuit is designed using microstrip lines and slot lines where microstrip lines are placed on the top surface of the substrate and slot lines on the reverse side of the substrate. The feed point is chosen in such a way that it provides the each patch element two RF signals with 90° phase difference. Therefore, the circular polarization is realized by employing microstrip-slot feed circuit. “Both-Sided MIC Technology” is used to design the proposed array antenna as it gives flexibility in the design process. The simulated return loss of the proposed array antenna is less than -45 dB at the design frequency. The 3 dB axial ratio bandwidth of 0.8% is obtained. The structure and the basic behavior along with the simulation results of the proposed circularly polarized array antenna are demonstrated in this paper.

NGOs and Their Implications in Promoting Social Development in Bangladesh: An Overview

Abstract: As the non-profit sector of a country, Non-Government Organizations (NGOs) are truly vital cog in the paradigm of social development in Bangladesh. It is generalized that Civil Society Organizations (CSOs) and NGOs have created jointly a new era of partnership in poverty alleviation activities, gender sensitive issues, education, health and been giving competent sustainability in the socio-economic conditions of Bangladesh. Since the NGOs are aimed to spreading awareness in people, strengthening and institutionalization of democracy promotion as well as ensuring maximum people participation in community- driven development approach. Therefore, the paper reviews these developmental phenomena launched by local and international NGOs in the context of Bangladesh especially in the field of education, health, environment, micro-finance, good governance, democracy and social justice etc. It investigates their contribution and present status along with necessary critical evaluations as well as factors that sometimes underestimate of NGOs' existence. The paper is designed with a theoretical conception of development contributed by NGOs along with its location in civil society and is fully literature-based that data and information have been accumulated from books, journals and electronic media as well. As the finding it has been seen that the sector is working for ensuring socio-economic development of poor and hard core poor people those are treated as the very negligible and marginalized by other two sectors i.e state and business working with political implications and profit maximization respectively whereas NGOs do for poors in assurance of financial solvence, basic education, nutritional status, participation in decision making for women both inside and outside of family and good governance etc. After all their activities are on the ground of no generation of profit.

A hands-on approach to estimate debris flow velocity for rational mitigation of debris hazard

Abstract: Rational estimation of debris flow velocity is one of the key issues in debris hazard mitigation. Among the various procedures, back-calculation of debris flow velocity is one of the most frequentl...