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.

Fabrication of Ni-NiO Foams by Powder Metallurgy Technique and Study of Bulk Crushing Strength

Abstract: Despite the importance of Nickel Oxide (NiO) in diverse functional applications, very little information is available on the mechanical properties of bulk or porous NiO or, mostly unnoticed. In this study, porous Ni-NiO foam was synthesized using space holding-powder metallurgy and sintering methods to produce opened-cell structure with macrogravel and Neolamarckia cadamba (Cadamba flower) like surface morphology. Four different types of porous Ni-NiO with different pore diameter of 35.65 ± 12.77, 36.10 ± 8.85, 68.20 ±7.36 and 62.45 ± 17.48 µm were fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam. The mechanical properties such as bulk crushing force of as synthesized Ni-NiO foam with various porosities such as 20.55, 27.35, 27.85 and 28.82 % exhibited the average crushing load of 115.40, 39.95, 138.10 and 151.20 N, respectively. This study suggests that crushing load of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO. HIGHLIGHTS Ni-NiO foam is synthesized using space holding-powder metallurgy and sintering methods Different pore diameter is fabricated for evaluating the effect of porosity on the mechanical properties of bulk porous Ni-NiO foam Crushing strength of Ni-NiO foam is not only depending on the porosity but also on the sintering temperature and crystallite sizes of NiO GRAPHICAL ABSTRACT

Manipulation of structural, electrical and magnetic properties on zinc substitution in cobalt nanoferrite

Abstract: Using wet chemical co-precipitation method cobalt-zinc nanoparticles (Co 1−x Zn x Fe 2 O 4 , with x =0.2, 0.4, 0.6 and 0.8) were synthesized and sintered at 1200 °C. The single phase spinel formation of all the samples has been confirmed by X-ray diffraction pattern. The scanning electron microscopy (SEM) was utilized for surface morphology study of samples. Impedance spectroscopy and initial permeability studies for all compositions have been performed in the frequency range 1 kHz to 120 MHz. We observed that the initial permeability remains more or less stable up to certain higher frequency range. The DC electrical resistivity demonstrates a definite break that has been explained in the light of conduction mechanism.

IoT Based Bidirectional Speed Control and Monitoring of Single Phase Induction Motors

Abstract: This paper presents the construction and laboratory investigation of an IoT (Internet of Things) based smart system to control, measure, and monitor the bidirectional speed control of single-phase induction motors (SPIM) remotely The design prototype consisting of two single-phase induction motors demonstrates multi-motor control The motors are turned ON and OFF by a specific relay operation To achieve the desired motor speed, the stator voltage control method has been applied by using Pulse Width Modulation (PWM) technique For reversing the motor direction of rotation, the stator magnetic field is reversed by swapping the contacts of auxiliary winding by relay operation Whenever the desired value is submitted for a specific operation from a specially designed website, the desired control signal is generated from a programmed microcontroller according to the user's command via a webserver using GSM communication Motor status data is measured using an IR sensor and observed remotely on the monitoring panel integrated with a web application The result shows little deviation compared to direct field measurement The IoT-based smart motor control system can be used in this modern age to continuously track, control, and monitor machines, goods, plants, etc for versatility in multi-purpose applications

Pyrolysis of ionic liquid pretreated lignite: Effect of 1-butyl-3-methylimidazolium methyl sulfate pretreatment on kinetic and thermodynamic parameters of lignite

Abstract: In this work, the effect of ionic liquid (IL) pretreatment on the pyrolytic behavior of lignite was analyzed by examining reactivity, kinetic, and thermodynamic parameters. Pretreatment of lignite ...

Comparison of Sacrificial Anode and Impressed Current Cathodic Protection Methods using Electric Resistance of Mild Steel

Abstract: Corrosion is a universal process occurring due to chemical reactions between metal and the environment. Corrosion of the metal can be controlled by numerous methods, and among many controlling methods cathodic protection is noteworthy. Cathodic protection of metal consists of two methods namely impressed current method and sacrificial anode method. Both methods deal with the transportation of electrons either receiving or donating from or to the metal or to the environment. Again, the electric resistance of a metal piece is inversely proportional to this cross-sectional area. If a metal bar corrodes fast, then its cross-sectional area reduces rapidly and its electric resistance increases highly. So, the relation between corrosion and electrical resistance of the metal is a helpful parameter to determine the corrosion rate. In this paper, we determine the corrosion behavior of mild steel exposed to different concentrations of ionic liquid to compare the possible variations in the corrosion protection techniques for the mild steel used.