International Islamic University, Chittagong

About: International Islamic University, Chittagong is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Debye model & Density functional theory. The organization has 1111 authors who have published 1089 publications receiving 7918 citations. The organization is also known as: IIUC.

Structural and electrical properties of Cu substituted Ni-Cd nanoferrites for microwave applications

Abstract: A series of Ni0.7-xCuxCd0.3Fe2O4 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) were synthesized by sol-gel auto combustion technique. The X-ray diffraction (XRD) analysis confirms the creation of cubic spinel structure of single-phase ferrites with crystallite size from 11 to15 nm. The lattice constant and grain size of the ferrite nanoparticles are found to increase with Cu content. The dielectric study of the materials at room temperature unveils a typical dispersion behavior in the lower frequency region (20 Hz - 1 KHz) and the dielectric constants remain constant at higher frequencies. The minimum loss tangent of ~0.019 at 13 MHz is found in the composition of x = 0.1. Both the complex impedance and electric modulus analysis confirms the presence of non-Debye type of relaxation phenomenon in the prepared ferrites. The ac conductivity bands suggest the hopping type of conduction and the ionic conduction relaxation mechanism in the investigated materials.

An Application of Data Mining and Machine Learning for Weather Forecasting

Abstract: Weather forecasting for an area where the weather and climate changes occurs spontaneously is a challenging task. Weather is non-linear systems because of various components having a grate impact on climate change such as humidity, wind speed, sea level and density of air. A strong forecasting system can play a vital role in different sectors like business, agricultural, tourism, transportation and construction. This paper exhibits the performance of data mining and machine learning techniques using Support Vector Regression (SVR) and Artificial Neural Networks (ANN) for a robust weather prediction purpose. To undertake the experiments 6-years historical weather dataset of rainfall and temperature of Chittagong metropolitan area were collected from Bangladesh Meteorological Department (BMD). The finding from this study is SVR can outperform the ANN in rainfall prediction and ANN can produce the better results than the SVR.

PI controller and park's transformation based control of dynamic voltage restorer for voltage sag minimization

Abstract: Modern electronics based on power electronic devices such as Programmable Logic Controllers (PLC), Distributed Control System (DCS) are used frequently in industrials plants to improve efficient production. These systems are extremely sensitive to power quality problem like voltage sag. Voltage sag is considered to be one of the most severe problems that cause failure, overheating and finally a total shutdown of industrial plants. It has been observed that, Dynamic Voltage Restorer (DVR) is the most efficient and effective modern custom power device exercised in power distribution networks to minimize voltage sags. The efficiency of the DVR depends on the performance of the control technique, which involved in switching the inverters. This paper presents modeling, analysis and simulation of a Dynamic Voltage Restorer (DVR) test systems using MATLAB Simulink for minimizing voltage sag by two promising controlling strategies: control using PI controller and control based on Park's Transformation. Simulation results of DVR controlling found by MATLAB Simulink here which demonstrates the well-organized plant applications. Moreover, this work shows that, control based on Park's Transformation provides better sag improvement than PI Control.

In Vitro and In Vivo Biological Activities of Cissus adnata (Roxb.)

Abstract: This study was conducted to evaluate the in vitro polyphenol content, antioxidant, cytotoxic, antibacterial, anthelmintic properties, and in vivo antinociceptive activity of the ethanol extract of Cissus adnata leaves (EECA) in different experimental models. Polyphenol contents were investigated using spectrophotometric techniques. Antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) radical-scavenging, ferric reducing power, and total antioxidant capacity assays. Cytotoxicity was determined by brine shrimp lethality bioassay and disc diffusion method was used for the antibacterial activity. Anthelmintic activity was studied using aquarium worm (Tubifex tubifex) whereas antinociceptive activity was evaluated in mice by acetic acid and formalin test. Phytochemical screening of EECA revealed the presence of alkaloids, carbohydrates, flavonoids, phenols, terpenoids, saponins, and tannins. EECA showed strong antioxidant activity with high polyphenol contents. It was observed that EECA possessed significant antibacterial activity with a low toxicity profile. EECA also demonstrated dose-dependent and statistically significant anthelmintic and antinociceptive activities. Our study shows that ethanol extract of C. adnata leaves possess strong antioxidant, antibacterial, anthelmintic and antinociceptive activities with lower toxicity. Further studies are needed to identify bioactive phytomolecules and to understand the mechanism of such actions better.