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.

Evaluation of the elemental distribution in soil samples collected from ship-breaking areas and an adjacent island

Abstract: Ship-breaking yards in the world mostly reside along the coastal areas which possess diverse elemental contents due to the presence of heavy minerals. So to explain the heavy elemental enrichment of ship-breaking sites in terms of only anthropogenic contribution is insufficient. While studying elemental distribution of ship-breaking sites, choosing appropriate control sample is vital. To evaluate the elemental distribution in ship-breaking yards of Bangladesh and in an adjacent island (Sandwip), soil samples from each site and some heavy minerals have been analyzed for Na, K, Sc, Cr, Fe, Co, As, Sb, Cs, La, Ce, Sm, Hf and Th abundances by neutron activation analysis. For assessing elemental distribution, pollution load index (PLI), geo-accumulation index and inter-element correlation study were performed. Co-related variation of Cr and Fe (r = 0.651) and chemical compositions of heavy minerals invoke that a significant portion of elemental enrichment in ship-breaking yards seems to have mineralogical origin while the enrichments of As, Sb and Cs (mean abundances: 11.3 ± 3.9, 5.66 ± 4.97 and 10.9 ± 6.6 ppm, respectively) are solely originated from anthropogenic activities (e.g., ship-breaking). On the other hand, elemental distribution of Sandwip (which is sometimes used as control sample) seems to be unaffected by the mainland ship-breaking activities and possesses crustal origin, though a minute fractionation of heavy metals is observed within the east (PLI: 0.84 ± 0.05) and west (PLI: 0.52 ± 0.04) side of the island. For the first time, this study reveals the mineralogical contribution of heavy elements in ship-breaking site and will be decisive for choosing proper elemental abundances of control site.

Maximum power point tracking of photovoltaic arrays in Matlab using fuzzy logic controller

Abstract: A generalized photovoltaic array simulation model in Matlab/Simulink environment is developed and presented in this paper. The model includes PV module and array for easy use on simulation platform. The proposed model is designed with a user-friendly icon and a dialog box like Simulink block libraries. Considering the effect of solar irradiance and temperature changes, the output current and voltage of PV modules are simulated and optimized using this model. A fuzzy logic based maximum power point tracker is also developed using the presented model in Matlab/Simulink. The maximum power point tracker is tested in changing environment of irradiance and/or temperature. It can successfully track the maximum power point more accurately and quicker than conventional perturb and observe based controller in these situations. The overall test results validate the efficiency of the model as well as the fuzzy controller which can be used in related research works.

A deep learning approach to predict autism spectrum disorder using multisite resting-state fmri

Abstract: Autism spectrum disorder (ASD) is a complex and degenerative neuro-developmental disorder. Most of the existing methods utilize functional magnetic resonance imaging (fMRI) to detect ASD with a very limited dataset which provides high accuracy but results in poor generalization. To overcome this limitation and to enhance the performance of the automated autism diagnosis model, in this paper, we propose an ASD detection model using functional connectivity features of resting-state fMRI data. Our proposed model utilizes two commonly used brain atlases, Craddock 200 (CC200) and Automated Anatomical Labelling (AAL), and two rarely used atlases Bootstrap Analysis of Stable Clusters (BASC) and Power. A deep neural network (DNN) classifier is used to perform the classification task. Simulation results indicate that the proposed model outperforms state-of-the-art methods in terms of accuracy. The mean accuracy of the proposed model was 88%, whereas the mean accuracy of the state-of-the-art methods ranged from 67% to 85%. The sensitivity, F1-score, and area under receiver operating characteristic curve (AUC) score of the proposed model were 90%, 87%, and 96%, respectively. Comparative analysis on various scoring strategies show the superiority of BASC atlas over other aforementioned atlases in classifying ASD and control.

Mechanical, electronic, optical, and thermodynamic properties of orthorhonmbic LiCuBiO4 crystal: a first–priciples study

Abstract: Density functional theory (DFT) based first-principles calculations using GGA+U method have been performed for the first time to investigate elastic, electronic, optical, thermodynamic properties including charge density, Fermi surface, Mulliken population analysis, and theoretical Vickers hardness of the newly synthesized LiCuBiO4 (LCBO) compound. The calculated structural parameters are in good agreement with available experimental results, which assessed the reliability of our calculations. The analysis of elastic constants indicates mechanical stability of the LCBO. The values of Poisson's and Pugh's ratios confirm the ductile nature of the LCBO. The mechanically anisotropy is found by the different anisotropy factors. The overlapping of valence and conduction bands near the Fermi level (EF) and the several bands crossing the EF reveal the metallic behaviour of the LCBO. The electronic charge density mapping and Mulliken population analysis exhibits a combination of covalent, ionic, and metallic bonding of the LCBO. The calculated Fermi surface comprised of two-dimensional topology due to the low-dispersion of O-2p and Cu-3d states, which implies the possible multi-band nature of LCBO. The analysis of thermodynamic and various optical properties suggest that LCBO can be a potential candidate for optoelectronic devices in the visible and ultraviolet energy regions and as a thermal barrier coating (TBC) material.