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An asymmetrical multilevel inverter with minimum voltage stress and fewer components for photovoltaic renewable-energy system

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Clean Energy 2024年第1期8卷 1-22页

作者： Rabail Memon mukhtiar ahmed mahar Abdul Sattar Larik Syed Asif Ali shah Department of Electrical Engineering Mehran University of Engineering and TechnologyJamshoroPakistan

The enhanced power quality provided by multilevel inverters(MLIs)has made them more appropriate for medium-and high-power applications,including photovoltaic ***,a prevalent limitation involves the necessity for numerous switches and increased voltage stress across these switches,consequently increasing the overall system *** address these challenges,a new 17-level asymmetrical MLI with fewer components and low voltage stress is proposed for the photovoltaic *** innovative MLI configuration has four direct current(DC)sources and 10 *** on the trinary sequence,the proposed topology uses photovoltaics with boost converters and fuzzy logic controllers as its DC *** equations are used to calculate cru-cial parameters for this proposed design,including total standing voltage per unit(TSVPU),cost function per level(CF/L),component count per level(CC/L)and voltage stress across the *** comparison is conducted by considering switches,DC sources,TSVPU,CF/L,gate driver circuits and CC/L with other existing MLI *** analysis is carried out under various conditions,encompassing different levels of irradiance,variable loads and modulation *** reduce the total harmonic distortion of the suggested topology,the phase opposition disposition approach has been *** suggested framework is simulated in MATLAB®/Simulink®.The results indicate that the proposed topology achieves a well-distributed stress profile across the switches and has CC/L of 1.23,TSVPU of 5 and CF/L of 4.58 and 5.76 with weight coefficients of 0.5 and 1.5,*** values are not-ably superior to those of existing MLI *** results demonstrate that the proposed topology maintains a consistent output at varying irradiance levels with FLCs and exhibits robust performance under variable loads and diverse modulation ***,the total harmonic distortion achieved with phase opposition disposi

关键词： asymmetrical multilevel inverter photovoltaic system renewable energy component count per level cost function per level total standing voltage per unit phase opposition disposition technique

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Inducing opto-electronic and spintronic trends in bilayer h-BN through TMO3 clusters incorporation: Ab-initio study

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Chinese Physics B 2019年第11期28卷 284-294页

作者： Irfan ahmed Muhammad Rafique mukhtiar ahmed mahar Abdul Sattar Larik Mohsin Ali Tunio Yong Shuai Mehran University of Engineering and Technology SZABCampusKhairpur Mirs’Pakistan School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Mehran University of Engineering and Technology JamshoroSindhPakistan

The band structure, magnetism, charge distribution, and optics parameters of TMO3–h-BN hybrid systems are investigated by adopting first-principles study(FPS) calculations. It is observed that the TMO3 clusters add finite magnetic moments to bilayer h-BN(BL/h-BN), thereby making it a magnetic two-dimensional(2D) material. Spin-polarized band structures for various TMO3–BL/h-BN hybrid models are calculated. After the incorporation of TMO3, BL/h-BN is converted into semimetal or conducting material in spin up/down bands, depending on the type of impurity cluster present in BL/h-BN lattice. Optics parameters are also investigated for the TMO3–BL/h-BN complex systems. The incorporation of TMO3 clusters modifies the absorption and extinction coefficient in visible range, while static reflectivity and refraction parameter increase. It can be surmised that the TMO3 substitution in BL/h-BN is a suitable technique to modify its physical parameters thus making it functional for nano/opto-electronic applications, and an experimental approach can be adapted to reinforce the outcomes of this study.

关键词： bilayer h-BN band structure density of states magnetic moments optics

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Power Factor Improvement of AC-DC Converter Based on Separately Excited DC Motor Using Passive Filter

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Open Journal of Energy Efficiency 2016年第3期5卷 71-77页

作者： Shazia Baloch mukhtiar ahmed mahar Raza Haider Shakeel ahmed Electrical Engineering Department Balochistan University of Engineering and Technology Khuzdar Pakistan Electrical Engineering Department Mehran University of Engineering and Technology Jamshoror Pakistan Civil Engineering Department Balochistan University of Engineering and Technology Khuzdar Pakistan

In industries DC motor drives are very essential due to their high performance applications such as its reliability, ease of control, low cost and simplicity. And speed control of these motors is very easy due to power electronic AC-DC converters. These power electronic converters are with prominent low power factor and higher Total Harmonic Distortion (THD). These converters operate only for short time resulting non-sinusoidal waveform. This problem of harmonic distortion can be mitigated by reshaping the non-sinusoidal waveform to pure sine wave. Different wave shaping techniques have been developed by using different filters among which one is tuned passive filter. This paper proposed power factor improvement and harmonic mitigation of AC-DC converters based on separately excited DC motor using tuned passive filter. In this context experimental model is designed and results are analyzed by power quality analyzer.

关键词： DC Motors AC-DC Converters Power Factor Total Harmonic Distortion Passive Filters

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The surveillance of arsenic levels in the drinking water of primary schools and the assessment of the potential cancer-related health risks of children in Multan, Pakistan

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Emerging Contaminants 2024年第1期10卷 17-23页

作者： Hidayatullah mahar Abdul Rehman Memon Aqsa Ishfaq Suhail ahmed Soomro Mehran University of Engineering&Technology JamshoroPakistan NFC Institute of Engineering&Technology MultanPakistan

To investigate the levels of arsenic(As)in the groundwater and drinking water of primary schools and their potential impact on human health is main objective of this *** assess risk,the following parameters i.e.,carcinogenic indices(CI),hazardous indexes(HI),carcinogenic risk(CR),and hazardous quotient(HQ)have been measured for both dermal and oral arsenic *** study has been focused on primary schools located in four tehsils of Multan,where water samples were *** levels,with concentrations ranging from 3.31 to 191 mg/l,exceeding the safe limit set by the World Health Organization(WHO)have been detected in 99.9%of the *** results show that arsenic content ranged from 3.31 to 191 mg/l,with 99.9%of the samples exceeding the World Health Organization's safe limit of 10 mg/*** CR and CI exceeded the USEPA limit of 10–6 in all four tehsils ranged from 2.6×10^(-6) to 9.4×10^(-6) and 0.00023 to 0.0009 respectively in both dermal and oral cases.,Multan Sadar(1.51,1.39)and Multan City(1.76,1.71)exhibited HI and HQ values that surpassed the threshold of 1.0,signaling a significant likelihood of chronic and cancer-causing health consequences for individuals who are exposed to polluted water causing *** findings suggest that the groundwater in the Multan district poses a significant health risk to humans due to high levels of arsenic *** contamination is associated with an increased risk of mortality from internal cancers(including liver,kidney,lung,and bladder),as well as a higher HI&CI incidence of skin ***,pregnancy outcomes are affected,with associations found between arsenic exposure and lower birth weight,and infant *** researchers propose that water supply organizations and educational institutions promptly take measures to ensure that the affected areas have access to arsenic-free drinking water for the well-being of students and residents.

关键词： Risk assessment Drinking water contamination Arsenic Primary school Pakistan

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Performance Evaluation of Energy Meters Under Nonlinear Loads

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Journal of Shanghai Jiaotong university(Science) 2017年第2期22卷 133-138页

作者： GUL Mehr 邰能灵 mahar mukhtiar ahmed 黄文焘 LARIK Abdul Sattar Department of Electrical Engineering Shanghai Jiao Tong University Department of Electrical Engineering Balochistan University of Information Technology Engineering and Management Sciences (BUITEMS) Department of Electrical Engineering Mehran University of Engineering & Technology

Due to rapid advancements in power electronics, the utilization of electronically switched loads and nonlinear loads is increasing gradually in the electrical power system. These loads create problems of measuring instruments, when connected to the power distribution systems. In this paper, an experimental investigation has been carried out to analyze the performance of single-phase watt-hour (induction and electronic types) energy meters that are being used in Pakistan. The accuracy of the energy meters has been tested under different household nonlinear loads, at various power factors and also at different supply voltage levels. Power factor and total harmonic distortion (THD) of different household loads are also recorded in the experimental work. A hardware based experimental setup has been designed to perform the experimental work. The experimental results have been compared to Water and Power Development Authority (WAPDA) standards for energy meters. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

关键词： energy meter accuracy nonlinear loads experimental investigation harmonic distortion power factor

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Advancements in prokaryotic systematics and the role of Bergey's International Society for Microbial Systematics in addressing challenges in the meta-data era

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National Science Review 2024年第7期11卷 292-304页

作者： Jian-Yu Jiao Rashidin Abdugheni Dao-Feng Zhang Iftikhar ahmed mukhtiar Ali Maria Chuvochina Svetlana N.Dedysh Xiuzhu Dong Markus G?ker Brian P.Hedlund Philip Hugenholtz Kamlesh Jangid Shuang-Jiang Liu Edward R.B.Moore Manik Prabhu Narsing Rao Aharon Oren Ramon Rossello-Mora Bhagwan Narayan Rekadwad Nimaichand Salam Wensheng Shu Iain C.Sutcliffe Wee Fei Aaron Teo Martha E.Trujillo Stephanus N.Venter William B.Whitman Guoping Zhao Wen-Jun Li State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) School of Life Sciences Sun Yat-Sen University State Key Laboratory of Desert and Oasis Ecology Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsXinjiang Institute of Ecology and Geography Chinese Academy of Sciences Jiangsu Province Engineering Research Center for Marine Bio-resources Sustainable Utilization&College of Oceanography Hohai University National Culture Collection of Pakistan(NCCP) Land Resources Research Institute(LRRI) National Agricultural Research Centre(NARC) The University of Queensland School of Chemistry and Molecular Biosciences Australian Centre for Ecogenomics Winogradsky Institute of Microbiology Research Center of BiotechnologyRussian Academy of Sciences State Key Laboratory of Microbial Resources Institute of Microbiology Chinese Academy of Sciences Leibniz Institute DSMZ–German Collection of Microorganisms and Cell Cultures School of Life Sciences University of Nevada Nevada Institute of Personalized Medicine University of Nevada Bioenergy Group MACS Collection of Microorganisms Agharkar Research Institute State Key Laboratory of Microbial Technology Shandong University Department of Infectious Disease Institute for Biomedicine and Culture Collection University of Gothenburg(CCUG) Institute for BiomedicineSahlgrenska AcademyUniversity of Gothenburg Instituto de Ciencias Aplicadas Facultad de Ingeniería Universidad Autónoma de Chile The Alexander Silberman Institute of Life Sciences The Edmond J.Safra Campus The Hebrew University of Jerusalem Marine Microbiology Group Department of Animal and Microbial Biodiversity Mediterranean Institute for Advanced Studies(IMEDEA CSIC-UIB) MicrobeAI Lab Division of Microbiology and Biotechnology Yenepoya Research Centre Yenepoya(Deemed to be University) National Agri-Food Biotechnology Institute Institute of Ecological Science Sch

Prokaryotes are ubiquitous in the biosphere, important for human health and drive diverse biological and environmental processes. Systematics of prokaryotes, whose origins can be traced to the discovery of microorganisms in the 17th century, has transitioned from a phenotype-based classification to a more comprehensive polyphasic taxonomy and eventually to the current genome-based taxonomic *** transition aligns with a foundational shift from studies focused on phenotypic traits that have limited comparative value to those using genome sequences. In this context, Bergey's Manual of Systematics of Archaea and Bacteria(BMSAB) and Bergey's International Society for Microbial Systematics(BISMiS) play a pivotal role in guiding prokaryotic systematics. This review focuses on the historical development of prokaryotic systematics with a focus on the roles of BMSAB and BISMiS. We also explore significant contributions and achievements by microbiologists, highlight the latest progress in the field and anticipate challenges and opportunities within prokaryotic systematics. Additionally, we outline five focal points of BISMiS that are aimed at addressing these challenges. In conclusion, our collaborative effort seeks to enhance ongoing advancements in prokaryotic systematics, ensuring its continued relevance and innovative characters in the contemporary landscape of genomics and bioinformatics.

关键词： prokaryotic systematics Bergey's Manual of Systematics of Archaea and Bacteria (BMSAB) Bergey's International Society for Microbial Systematics (BISMiS) meta-data era

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A Framework for e-Voting System Based on Blockchain and Distributed Ledger Technologies

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Computers, Materials & Continua 2022年第7期72卷 417-440页

作者： Shahid Hussain Danwar Javed ahmed mahar Aneela Kiran Institute of Computer Science Shah Abdul Latif UniversityKhairpur66020SindhPakistan

Election allows the voter of a country to select the most suitable group of candidates to run the *** in Pakistan is simply paper-based method but some certain political and socio-economic issues turn that simple process in complicated and disputes *** of such problems are consisting of many methods including the e-voting *** e-voting system facilitates the voters to cast their votes by electronic means with very easy and convenient *** also allows maintaining the security and secrecy of the voter along with election *** voting reduces the human-involvement throughout the process from start to the *** system is not established yet in ***,every election is disputed *** this paper we proposed the framework of an e-voting system and simulation with the use of blockchain ledger *** proposed framework owns the capacity to deal with ballots in *** novelty of the framework is that the e-voting system is linked to National Database and Registration Authority(NADRA)database which assures voter’s *** fundamental requirements were kept in consideration during the performance evaluation of the *** results are processed and depicted specially with reference to the number of voters and voting stations,real time of vote casting,network bandwidth and controlling *** results support the decision makers and guide them in the foundation and customization of an e-voting system in Pakistan.

关键词： Simulation modeling e-voting system blockchain technology distributed ledger

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Temporal change assessment of agricultural land by Satellite Remote Sensing (SRS) technique

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Natural Science 2013年第6期5卷 689-694页

作者： Gohar Ali mahar Razzaq ahmed Mohammad Jawed Iqbal Ain Zubaida Unit for Rehabilitation and Groundwater Research King Abdulaziz University Jeddah KSA Department of Geography Federal Urdu University of Art Sciences and Technology Karachi Pakistan

Agriculture is the vital economic activity of rural society in nearly all of Pakistan. The Winder-Sonmiani area located at the Makran coast near the city of Hub in Pakistan is economically very promising. Cropping, horticulture, fruit farming and animal husbandry are the common land use activities in the area while fishing along the coast is an important economic activity. Owing to the use of the Satellite Remote Sensing technique (SRST), the triangular basin shape structure of the Winder area has been found to be spatially very promising for agricultural activities. Positive change in the use of agriculture land was detected from the Satellite images of different periods. Use of modern technology and incentives provided by the government have advanced improvement in agriculture.

关键词： Agriculture Spatiotemporal Satellite Remote Sensing (SRS) GIS Landsat

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Optimizing Yield and Quality of Canola Cultivars Using Various Potash Levels

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American Journal of Plant Sciences 2015年第8期6卷 1233-1242页

作者： Ansaar ahmed Fayaz Ali Inamullah Amjad Ali Arif Ullah Rubina Naz Amanullah mahar Shahmir Ali Kalhoro Department of Agronomy The University of Agriculture Peshawar Pakistan College of Natural Resources and Environment Northwest A&F University Yangling China College of Economics and Management Northwest A&F University Yangling China Department of Botany Kohat University of Science & Technology Kohat Pakistan Centre for Environmental Sciences University of Sindh Jamshoro Pakistan Faculty of Agriculture Lasbela University of Agriculture Water & Marine Sciences Lasbela Pakistan

The response of several canola cultivars to different potassium (K) levels was investigated in terms of various agronomic parameters including yields, oil and protein contents in a trial conducted at The University of Agriculture, Peshawar-Pakistan in Rabi 2010-11. Three cultivars including Bulbul-98, Abaseen-95 and Dure-NIFA, with five levels of potassium i.e. 0, 30, 60, 90 and 120 kg·ha-1 were used in Randomized Complete Block (RCB) design with four replications and factorial arrangement. A larger number of days to 50% flowering (116.6 days), plant height (203.8 cm), leaf area index (4.4), 1000 grain weight (3.5 g), biological yield (13189.3 kg·ha-1), grain yield (1799.2 kg·ha-1) and harvest index (13.9%) were obtained in K applied plots than the plots where K was not applied. The highest oil (45.1%) and protein (27.7%) was obtained in plots where K was applied at the rate of 120 and 90 kg·ha-1, respectively. Among cultivars, Bulbul-98 and Abaseen-95 had higher seed yield and oil percentage. Bulbul-98 had more protein content than Abaseen-95 and Durre-NIFA. On average, cultivars gave higher and at par grain yield at 60, 90 and 120 kg·ha-1. However, they produced higher and at par oil and protein percentage at 90 and 120 kg·ha-1. Bul-bul-98 and Abaseen-95 are recommended for higher grain yield and oil content for general culti-vation in Peshawar valley. However, for higher protein content, Bulbul-98 is better. Potassium applied at 60 kg·ha-1 is recommended for higher grain yield, however, for higher oil and protein content, K at 90 kg·ha-1 is recommended.

关键词： Biological Yield Canola Potassium Harvest Index Protein Oil

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Okra Leaves—Agricultural Waste for the Removal of Cr(III) and Cr(VI) from Contaminated Water

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American Journal of Analytical Chemistry 2016年第4期7卷 395-409页

作者： Mazhar Iqbal Khaskheli Saima Qayyum Memon Zaheer ahmed Chandio Wahid Bux Jatoi Mohammad Tariq mahar Faiz Mohammad Khokhar M. A. Kazi Institute of Chemistry University of Sindh Jamshoro Pakistan Institute of Chemistry Shah Abdul Latif University Khairpur Sindh Pakistan

The present study demonstrates the sorptive efficiency of okra leaves for the Cr(III) and Cr(VI) in aqueous system. The batch dynamic sorption method was carried out as the function of the pH of the solution, sorbent doze, initial bulk concentration, shaking speed and contact time. The experimental data were examined by Langmuir and Freundlich isotherms. Cr(III) at pH-4.0 and Cr(VI) pH-2.0 showed a maximum sorption capacities 221.17 mg/g and 81.94 mg/g respectively. Kinetically experimental data of both chromium species were well fitted to pseudo second order rate, Elovich, Morris-Weber and Richenberg equations. Positive values of enthalpy change and negative values of Gibbs free energy indicated the endothermic and spontaneous nature of sorption reaction respectively. The developed method was applied to real ground water samples (affected by industrial wastewater). Up to 92.15% of chromium metal was removed from the real water samples.

关键词： Okra Leaves Chromium Pseudo Second Order

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