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.

Influence of Yb3+on the structural, electrical and optical properties of sol-gel synthesized Ni-Zn nanoferrites

Abstract: Polycrystalline Yb substituted NiZn nanoferrites with the compositions of Ni05Zn05YbxFe2-xO4 (x= 000, 004, 008, 012, 016 and 020) have been synthesized using sol gel auto combustion technique Single phase cubic spinel structure has been confirmed by the X ray diffraction (XRD) patterns Larger lattice constants of the compositions are found with increasing Yb3+ concentration while the average grain size (52 to 18 nm) has noticeable decrease as Yb3+ content is increased The presence of all existing elements as well as the purity of the samples has also been confirmed from energy dispersive X ray spectroscopic (EDS) analysis Frequency dependent dielectric constant, dielectric loss, dielectric relaxation time, AC and DC resistivity of the compositions have also been examined at room temperature The DC resistivity value is found in the order of 10 to power 10 (omega-cm) which is at least four orders greater than the ferrites prepared by conventional method This larger value of resistivity attributes due to very small grain size and successfully explained using the Verwey and deBoer hopping conduction model The contribution of grain and grain boundary resistance has been elucidated using Cole Cole plot The study of temperature dependent DC resistivity confirms the semiconducting nature of all titled compositions wherein bandgap (optical) increases from 273 eV to 325 eV with the increase of Yb content The high value of resistivity is of notable achievement for the compositions that make them a potential candidate for implication in the high frequency applications where reduction of eddy current loss is highly required

Wi-Fi Based Real Time Communication for Disaster and Emergencies

Abstract: Most of the time communication infrastructure is badly hampered by the natural disaster. Many people are trapped inside their house during disaster time and they cannot communicate with others as there is no network coverage. This paper aims to help those affected people by using Wi-Fi communication. We developed a real-time communication system for Android users where they can send a message and make an audio call through Wi-Fi and also develop an alarming system by which we can detect the appropriate location of the affected people. For audio call, we use UDP (User Datagram Protocol) and for messaging we use TCP/IP. When there is an audio call request it starts a peer to peer communication between the users. TCP/IP is used for messaging because this is a connection-oriented protocol which means there is a guarantee of message arrival. As our system is worked within the Wi-Fi hotspot range, the experiment shows that it can cover up to 32 meters (105 feet).

Similarity Solutions for Unsteady Hydromagnetic Free Convection Boundary Layer Flow over Flat Plates with Thermophoresis

Abstract: This paper is focused on the analysis of thermophoresis on an unsteady two dimensional free convective boundary layer flow along a permeable inclined flat plate in the presence of magnetic field and thermophoresis. Governing time dependent partial differential equations are non- dimensionalzed and transformed into a system of nonlinear ordinary differential equations by applying similarity transformations. These are solved numerically by using the shooting method along with Runge-Kutta sixth order integration scheme. Numerical results for the dimensionless velocity, temperature and concentration profiles have been obtained and displayed graphically. The skin-friction coefficient, wall heat transfer coefficient and wall deposition flux rate have also been obtained and are presented in tabular form. The obtained numerical results also show that increased unsteadiness parameter significantly controls the thermophoretic particle.

Numerical investigation on the performance of new ultra-thin CZTS solar cell using SCAPS

Abstract: This paper suggests an upgraded structure for CZTS solar cells by simulating an ultra-thin one dimensional CZTS cell with an added absorber layer of silicon and analyzing the cell for several parameters like operating temperature, thickness of absorber layer and concentration of acceptor carrier. Simulation result denotes that with a given extra silicon absorber layer, efficiency of CZTS solar cell shows positive, negative and varying correlation against respective changes in thickness, temperature and concentration. In case of increased concentration of the absorber layer, initially it pushes the efficiency up but eventually falls back after achieving the maximum level. Overall the best conditions of different parameters and respective changes in efficiency of the CZTS solar cell are presented in this work.

Optimization of Features for Classification of Parkinson's Disease from Vocal Dysphonia

Abstract: Parkinsons disease is considered most prominent neurological disease after Alzheimer and Epilepsy. There is no defined test for early diagnosis of Parkinson's patient and medical decisions are provided based on the medical history of the patient and hence the possibility of misdiagnosis. Parkinsons disease influxes different prospects of a patient and in 90% cases vocal dysphonia is present an analysis of the vocal dysphonia can be considered as the early biomarker of decision making for medical practitioners and neurologists as well as biometric analysis. This study aims at vocal dysphonia analysis of Parkinson's patient from voice dataset with different machine learning algorithms with a goal to achieve better performance with less number of attributes. A comparative study is performed where k-Nearest performed approximately with 98% accuracy with 5 relevant attributes, Random Tree with 100% accuracy with 1 related attribute. In addition in the case of Multi-Layer Perceptions with different hiddenlayers, the performance is evaluated. It is observed that MDVP: Fo, MDVP: Shimmer, RPDE, Spread1 attributes contribute more to efficient classification accuracy.