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.

Effect of zinc substitution on structural, morphological and magnetic properties of cobalt nanocrystalline ferrites prepared by co-precipitation method

Abstract: In solid state sintering technology, initial particle size and shape are important factors to determine the properties of the sintered products. The nanoferrites of single phase cubic spinel structure of zinc-substituted cobalt ferrite, Co1−xZnxFe2O4 (x = 0.2, 0.4, 0.6 and 0.8) were synthesized by wet chemical co-precipitation method followed by sintering at 1000 and 1100 °C for 3 h in air. The structural, morphological and magnetic properties of the compositions were estimated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Mossbauer spectroscopy (MS) and vibrating sample magnetometer (VSM). The porosity of the compositions was found to vary in the range between 2.7–5.2% at sintering temperature 1000 and 1100 °C. The density of the individual sample was observed to decrease with increase in Zn content. The values of the maximum saturation magnetization were found 89.8 and 91.9 emu/g for the samples (x = 0.2) sintered at 1000 and 1100 °C, respectively. The effect of zinc concentration on lattice constant and grain size was examined. Increase in the lattice constant, porosity, ionic radii, the distance between the magnetic ions and bond lengths on tetrahedral and octahedral sites have been observed with the increase of zinc content. Due to zinc incorporation, the movement of iron ions from the tetrahedral site to the octahedral site was revealed by Mossbauer spectroscopy. The zinc substitution has a significant effect on structural and magnetic properties like saturation magnetization, remanent magnetization, coercivity, Curie temperature, etc. of Co1−xZnxFe2O4 ferrite.

Heat Transfer and Pressure Drop Characteristics in Turbulent Flow Through a Tube

Abstract: An experimental investigation has been carried out for turbulent flow through a tube with perforated strip inserts. Strips were of mild steels with circular holes of different diameters. Flow varies, with ranging Reynolds numbers from 15,000 to 47,000. Air velocity, tube wall temperatures, and pressure drops were measured for a plain and strip-inserted tube. The heat transfer coefficient and friction factor were found to be 2.80 times and 1.8 times, respectively, that of the plain tube. The heat transfer performance was evaluated and found to be 2.3 times that of the plain tube based on constant blower power.

A smart metering system for wireless power measurement with mobile application

Abstract: At present, advanced meter enabled with wireless machine-to-machine (M2M) communication can play a pivotal role for energy measurement in smart grid. However, the traditional metering and billing system implemented in developing countries (e.g. Bangladesh) even some developed countries is too non-automated and complex that leads a wake-up call to establish a robust and smart metering system to measure energy for user convenience. In this paper, an automated smart metering system is presented to measure energy consumption wirelessly for residential/ industrial areas. The measurement system is an ARDUINO based master-slave wireless technology that incorporates with smart billing payment scheme via Android mobile application. This wireless technology requires a pair of RF transmitter and receiver for transmitting energy consumption data, and for subsequent billing and payment system. Here the authors also measure the performance of the proposed system analytically.

Enhancement the performance of Molybdenum Telluride solar cells with Zinc Telluride BSF

Abstract: The binary semiconductor compound Molybdenum telluride (MoTe 2 ) is For high efficiency and better thermal stability, Molybdenum telluride (MoTe 2 ) is considered as potential solar cell. AMPS (Analysis of Microelectronic and Photonic Structures) simulator is used to investigate the cell performance parameters for 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 Zinc Telluride (ZnTe) as back surface field (BSF) above the back contact metal. The highest conversion efficiency of 25.29% was found for ZnTe BSF with only 0.7 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 ZnTe BSF showed better stability.

A User-Centric Design Approach to Understand International Education in the Contemporary World: Motivations and Gender Preferences for Studying in Europe:

Abstract: Education holds promise as a vehicle for sustainable global development and human capacity development, as reflected in the Sustainable Development Goals set by the United Nations. International ed...