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Sliding mode controller design for frequency regulation in an interconnected power system

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Protection and Control of Modern Power Systems 2021年第1期6卷 77-88页

作者： Anand Kumar md nishat anwar Shekhar Kumar Department of Electrical Engineering National Institute of Technology PatnaPatnaBiharIndia

In this paper, a Sliding mode controller design method for frequency regulation in an interconnected power system is presented. A sliding surface having four parameters has been selected for the load frequency control (LFC) system model. In order to achieve an optimal result, the parameter of the controller is obtained by grey wolf optimization (GWO) and particle swarm optimization (PSO) techniques. The objective function for optimization has been considered as the integral of square of error of deviation in frequency and tie-line power exchange. The method has been validated through simulation of a single area as well as a multi-area power system. The performance of the Sliding mode controller has also been analyzed for parametric variation and random loading patterns. The performance of the proposed method is better than recently reported methods. The performance of the proposed Sliding mode controller via GWO has 88.91% improvement in peak value of frequency deviation over the method of anwar and Pan in case study 1 and similar improvement has been observed over different case studies taken from the literature.

关键词： Load frequency control Sliding mode control(SMC) Grey wolf optimization Particle swarm optimization Multi-area power system

A unified approach of PID controller design for unstable processes with time delay

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Journal of Central South University 2020年第9期27卷 2643-2661页

作者： Ashraf RAZA md nishat anwar Electrical Engineering Department National Institute of TechnologyPatna-800005India

This paper addresses a unified approach of the PID controller design for low as well as high order unstable processes with time *** design method is based on the direct synthesis(DS)approach to achieve the enhanced load disturbance *** improve the servo response,a two-degree of freedom control scheme has been considered.A suitable guideline has been provided to select the desired reference model in the DS *** direct synthesis controller has been approximated to the PID controller using the frequency response matching method.A consistently better performance has been obtained in comparison with the recently reported methods.

关键词： unstable process maximum sensitivity time delay higher order process direct synthesis method frequency response matching

Improved luminescence and photocatalytic properties of Sm^(3+)-doped ZnO nanoparticles via modified sol-gel route:A unified experimental and DFT+U approach

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Journal of Rare Earths 2023年第4期41卷 550-560页

作者： Sikder Ashikuzzaman Ayon Sajjad Hasan md Muktadir Billah Sadiq Shahriyar nishat Alamgir Kabir Department of Materials and Metallurgical Engineering Bangladesh University of Engineering and TechnologyDhaka1000Bangladesh Department of Physics Bangladesh University of Engineering and TechnologyDhaka1000Bangladesh Department of Materials Science&Engineering Rensselaer Polytechnic Institute(RPI)NY12180USA Department of Physics University of DhakaDhaka1000Bangladesh

In the current study,a modified sol-gel route was used to produce undoped and Sm^(3+)doped(1 mol%,3 mol%and 5 mol%)ZnO nanoparticles(NPs).The study of opto-structural properties of Sm^(3+)doped NPs was carried out both experimentally and *** dissolution of Sm^(3+)ions into the ZnO lattice is obviously seen from X-ray diffraction(XRD)*** evolution with doping was studied using field emission scanning electron microscopy(FESEM)and transmission electron microscopy(TEM).X-ray photoelectron spectroscopy(XPS)was carried out to confirm the prese nce of Sm~(3+)on the doped *** dopant quantity results in a redshift of the NPs along with a reduction in bandgap with increasing abso rption in the visible range,and a minimum of 3.18 eV of optical bandgap for Zn_(0.97)Sm_(0.03)O is *** spectroscopy reveals a drop in the recombination rate of electron-hole with increasing doping content till 3 mol%,followed by an increase of Zn_(0.95)Sm_(0.05)*** electron-hole pair recombination is revealed by the orange band in the luminescence *** analysis was also carried out with density functional theory(DFT).This work also unfolds the fundamental understanding of the structural properties of the synthesized NPs to enhance photocatalytic activity ***,photocatalytic activity for the optimum composition,i.e.,3 mol%,was assessed experimentally.

关键词： Samarium XPS Recombination rate Photocatalytic First principle Defect state

A software-based approach in designing a rooftop bifacial PV system for the North Hall of Residence, IUT

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Clean Energy 2021年第3期5卷 403-422页

作者： Abdullah Al Mehadi Misbahul Alam Chowdhury Mirza Muntasir nishat Fahim Faisal md Minhajul Islam Islamic University of Technology Board-BazarGazipurDhaka-1704Bangladesh

Bifacial rooftop photovoltaic panels appear to be an excellent means of power generation in this era of urbanization,especially for land-limited countries like *** paper presents a software-based approach to design and simulate a bifacial solar-panel-based energy model on the rooftop of the North Hall of Residence of the Islamic University of Technology,*** vertically mounted model investigates the feasibility and applicability of such an energy model in a university residence,situated in a load-shedding-prone ***,three prominent software platforms,namely PVSOL,PVsyst and System Advisor Model(SAM),are brought into action and rigorous simulations are performed for three different orientations;promising outcomes are observed in terms of annual energy yield,bifacial gain(BG)and consumption coverage of the grid and PV *** annual energy demand of the North Hall is~444733.5 *** three orientations can generate annually 92508.62,94643.48 and 86758.94 kWh,***,it is evident that the proposed orientations can supply almost 19-21%of the site’s annual *** BG analysis shows an overall increase in energy gain of 13%,15.6%and 6%for Orientation-1,Orientation-2 and Orientation-3,respectively.A rigorous comparative analysis and deviation analysis among the software results has been accomplished to gain more insight into the feasibility of the proposed ***,we have focused on a detailed software-based estimation of energy production for different orientations of the PV panels,considering several factors,which will provide prior knowledge and assessment before going for hardware implementation in the future.

关键词： bifacial solar PV panel PVSOL PVsyst SAM annual energy yield bifacial gain

Phytochemical screening and in vitro bioactivities of the extracts of aerial part of Boerhavia diffusa Linn.

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Asian Pacific Journal of Tropical Biomedicine 2012年第9期2卷 673-678页

作者： Apurba Sarker Apu Mahmuda Sultana Liza A.T.M.Jamaluddin md.Amran Howlader Repon Kumer Saha Farhana Rizwan nishat Nasrin Department of Pharmacy East West University

Objective:To investigate the bioactivities of crude n-hexane,ethyl acetate and methanol extracts of aerial part of Boerhavia diffusa Linn.(***) and its phytochemical ***: the identification of phyloconstituents and assay of antioxidant,thrombolytic,cytotoxic, antimicrobial activities were conducted using specific standard in vitro ***:The results showed that the plant extracts were a rich source of *** extract showed higher antioxidant,thrombolytic activity and less cytotoxic activity than those of n-hexane and ethyl acetate extracts of A *** the bioactivities,antioxidant activity was the most notable compared to the positive control and thus could be a potential rich source of natural *** case of antimicrobial screening,crude extracts of the plant showed remarkable antibacterial activity against tested *** the extracts showed significant inhibitory activity against Candida albicuns,at a concentration of 1000 μg/***:The present findings suggest that,the plant widely available in Bangladesh,could be a prominent source of medicinally important natural compounds.

关键词： Boerhavia diffusa Antioxidant Cytotoxic Thrombolytic Antimicrobial DPPH NO

Comparison of Sternal Wound Complication after Off-Pump CABG between Skeletonized and Pedicled LIMA Harvesting: A Single Centre Experience in Bangladesh

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World Journal of Cardiovascular Surgery 2023年第6期13卷 101-110页

作者： M. Asmaul Alam Al Nur md. Aslam Hossain md. Abir Tazim Chowdhury Farhat Tabassum nishat Munama Magdum Department of Cardiac Surgery National Institute of Cardiovascular Diseases Dhaka Bangladesh Department of Cardiac Surgery Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh Department of Cardiothoracic and Vascular Surgery Evercare Hospital Dhaka Bangladesh Department of Casualty Dhaka Medical College Hospital Dhaka Bangladesh Department of Community Medicine Shaheed Monsur Ali Medical College Dhaka Bangladesh

Background: Off-pump coronary artery bypass grafting (OPCAB) is a surgical procedure that has gained popularity due to its potential benefits over traditional coronary artery bypass grafting, including reduced morbidity and mortality. However, sternal wound complication (SWC) remains challenging following the procedure. The technique of left internal mammary artery (LIMA) harvesting has been shown to impact the incidence of SWC. This study aimed to compare the incidence of SWC between two techniques of LIMA harvesting, i.e., skeletonized and pedicled. Methods: The study was conducted at the Department of Cardiac Surgery, Bangabandhu Sheikh Mujib Medical University, and included 60 patients who underwent OPCAB. The patients were divided into two groups of 30 each based on the technique of LIMA harvesting used, i.e., skeletonized (group A) or pedicled (group B). The postoperative ICU care was given to each patient as per the protocol. The statistical analysis was conducted using the SPSS version 26.0 for Windows software. Results: The results showed that 5 (8.33%) patients developed SWC, with 1 (1.67%) patient in group A and 4 (6.66%) patients in group B. However, the occurrence of SWC was not statistically significant between the two groups (p = 0.35). The mean age, gender distribution, and comorbidities such as hypertension, diabetes, dyslipidemia, and anemia were also not statistically significant between the two groups. The number of smokers was statistically significant between the two groups (p = 0.03), and the occurrence of SWC was found to be higher in smoker patients in group B (p = 0.04). Preoperative and postoperative parameters such as duration of operation, duration of mechanical ventilation, duration of chest drains, duration of the central venous line, and amount of postoperative mediastinal bleeding were also not statistically significant between the two groups. The distribution of wound complications, duration of ICU stays, and hospital stay between t

关键词： Sternal Wound Complication (SWC) Off-Pump Coronary Artery Bypass Grafting (OPCAB) Left Internal Mammary Artery (LIMA) Skeletonized LIMA Harvesting Pedicle LIMA Harvesting

Development of Genetic Algorithm (GA) Based Optimized PID Controller for Stability Analysis of DC-DC Buck Converter

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Journal of Power and Energy Engineering 2020年第9期8卷 8-19页

作者： Mirza Muntasir nishat Fahim Faisal Anik Jawad Evan md. Moshiour Rahaman md. Sadman Sifat H. M. Fazle Rabbi Department of Electrical and Electronic Engineering Islamic University of Technology Dhaka Bangladesh

This paper delineates a conventional buck converter controlled by optimized PID controller where Genetic Algorithm (GA) is employed with a view to enhancing the performance by analyzing the performance parameters. Genetic Algorithm is a probabilistic search algorithm which is substantially used as an optimization technique in power electronics. A bunch of modifications have already been introduced to enhance the performance depending upon the applications. However, in this paper, modified genetic algorithm has been used in order to tune the key parameters in the converter. Hence, an analysis is carried out where the performance of the converter is illustrated in terms of rise time, settling time and percentage of overshoot by deploying GA based PID controller and the overall comparative study is presented. Responses of the overall system are accumulated through rigorous simulation in MATLAB environment.

关键词： Genetic Algorithm Optimization PID Controller Converter: State Space Average Method

A Novel Topology of Single-Phase AC-DC Integrated Boost-SEPIC (IBS) Converter Using Common Part Sharing Method (CPSM) for High Step-Up Applications

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Journal of Power and Energy Engineering 2018年第6期6卷 38-47页

作者： Mohammad Bazlur Rashid Mohammad Abdul Moin Oninda Fahim Faisal Mirza Muntasir nishat Golam Sarowar md. Ashraful Hoque Department of Electrical and Electronic Engineering Islamic University of Technology Gazipur Bangladesh

A novel topology of Integrated Boost-SEPIC (IBS) AC-DC converter using common part sharing method (CPSM) has been proposed in this paper. Conventional boost converters with bridge rectifier configuration are inefficient due to limited voltage step-up ratio which may not be applicable for high step-up applications as in the case of micro generators. The proposed IBS topology is based on the common part sharing method capable of operating both for positive and negative half cycle of the input signal. Result and simulation were conducted using PSIM environment. The proposed AC-DC IBS topology eliminates the requirement of bridge rectifier achieving high efficiency (about 99%), improved power factor (0.75, leading) and lower THD (about 38.8%) which is within IEEE standard.

关键词： Integrated Boost-SEPIC (IBS) Bridgeless AC-DC Converter Voltage Gain THD Minimization Efficiency Improvement Power Factor Correction