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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： Memon, Rabail Mahar, Mukhtiar ahmed Larik, Abdul Sattar Shah, syed Asif Ali Mehran Univ Engn & Technol Dept Elect Engn Jamshoro Pakistan

The enhanced power quality provided by multilevel inverters (MLIs) has made them more appropriate for medium- and high-power applications, including photovoltaic systems. Nevertheless, a prevalent limitation involves the necessity for numerous switches and increased voltage stress across these switches, consequently increasing the overall system cost. To address these challenges, a new 17-level asymmetrical MLI with fewer components and low voltage stress is proposed for the photovoltaic system. This innovative MLI configuration has four direct current (DC) sources and 10 switches. Based on the trinary sequence, the proposed topology uses photovoltaics with boost converters and fuzzy logic controllers as its DC sources. Mathematical equations are used to calculate crucial 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 switches. The comparison is conducted by considering switches, DC sources, TSVPU, CF/L, gate driver circuits and CC/L with other existing MLI topologies. The analysis is carried out under various conditions, encompassing different levels of irradiance, variable loads and modulation indices. To reduce the total harmonic distortion of the suggested topology, the phase opposition disposition approach has been incorporated. The suggested framework is simulated in MATLAB (R)/Simulink (R). 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, respectively. These values are notably superior to those of existing MLI topologies. Simulation 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 indices. Furthermore, the total harmonic disto

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 CONVERTER TOPOLOGY REDUCED NUMBER IMPLEMENTATION PERFORMANCE CONNECTION REDUCTION DESIGN SINGLE

AI-Driven Energy Optimization in UAV-Assisted Routing for Enhanced Wireless Sensor Networks Performance

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Computers, Materials & Continua 2024年第9期80卷 4085-4110页

作者： syed Kamran Haider Abbas ahmed Noman Mujeeb Khan Ali Nauman Sung Won Kim College of Internet of Things(IoT)Engineering Hohai UniversityChangzhou213001China Department of Electrical and Electronics Engineering Beaconhouse International CollegeIslamabad44000Pakistan School of Computer Science and Engineering Yeungnam UniversityGyeongsan38428Republic of Korea

In recent advancements within wireless sensor networks(WSN),the deployment of unmanned aerial vehicles(UAVs)has emerged as a groundbreaking strategy for enhancing routing efficiency and overall network *** research introduces a sophisticated framework,driven by computational intelligence,that merges clustering techniques with UAV mobility to refine routing strategies in *** proposed approach divides the sensor field into distinct sectors and implements a novel weighting system for the selection of cluster heads(CHs).This system is primarily aimed at reducing energy consumption through meticulously planned routing and path *** a greedy algorithm for inter-cluster dialogue,our framework orchestrates CHs into an efficient communication *** comparative analysis,the proposed model demonstrates a marked improvement over traditional methods such as the cluster chain mobile agent routing(CCMAR)and the energy-efficient cluster-based dynamic algorithms(ECCRA).Specifically,it showcases an impressive 15%increase in energy conservation and a 20%reduction in data transmission time,highlighting its advanced ***,this paper investigates the impact of various network parameters on the efficiency and robustness of the WSN,emphasizing the vital role of sophisticated computational strategies in optimizing network operations.

关键词： UAV trajectory clustering next-generation wireless sensor network(NGWSN) energy efficiency mobile sink

A review:Health benefits and physicochemical characteristics of blended vegetable oils

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Grain & Oil Science and Technology 2024年第2期7卷 113-123页

作者： Hina Daud Memon Sarfaraz ahmed Mahesar Sirajuddin Huseyin Kara syed Tufail Hussain Sherazi Mohammad Younis Talpur National Centre of Excellence in Analytical Chemistry University of SindhJamshoro 76080Pakistan International Center for Chemical and Biological Sciences HEJ Research Institute of ChemistryUniversity of KarachiKarachi 75270Pakistan Department of Chemistry Faculty of ScienceSelcuk UniversityKonya 42075Turkey Dr.M.A.Kazi Institute of Chemistry University of SindhJamshoro 76080Pakistan

Oil blending is the method of choice used worldwide to improve oxidative stability and nutritional *** is no such edible oil/fat that meets all the recommendations from the health point of *** fatty acid composition of vegetable oils decides the fate of the *** single oil is unable to provide a balanced amount of fatty acids(FAs)required/recommended on a daily intake *** oils/fats is an appropriate procedure of physically mixing multiple oils in suitable proportions which may provide functional lipids with improved antioxidant potential and desirable physical and chemical *** review piled up the accessible data on the blending of diverse oils/fats in the combination of binary,ternary,quaternary,or other types of oils into a single blended *** can be found very convincing towards appropriate FA profile,enhancement in physicochemical characteristics,and augmented stability for the period of storage or when used as cooking/frying processes which could ultimately serve as an effectual dietary intervention towards the health protectiveness.

关键词： Vegetable oil Oil blending Physicochemical properties Nutritional benefits

Genesis of Graphite in Betul Belt, Madhya Pradesh, India:Inferences Based on Petrographic and Other Studies

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Prevalence of post-traumatic stress disorder and depressive symptoms among civilians residing in armed conflict-affected regions:a systematic review and meta-analysis

Open Journal of Geology（地质学期刊） 2022年第11期

作者： rajendra kumar sharma biswajeet lenka syed ajaz ahmed

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General Psychiatry 2024年第3期37卷 324-334页

作者： syed Hassan ahmed Aabia Zakai Maha Zahi Muhammad Youshay Jawad Rui Fu Michael Chaiton Dow University of Health Sciences KarachiPakistan Department of Psychiatry and Behavioral Health Penn State College of MedicineHersheyPennsylvaniaUSA Dalla Lana School of Public Health University of TorontoTorontoOntarioCanada institute of Mental Health Policy Research The Center of Addiction and Mental HealthTorontoOntarioCanada

Background Globally,populations afflicted by armed conflict are known to have high rates of mental health *** This meta-analysis aims to estimate the prevalence of post-traumatic stress disorder(PTSD)and depressive symptoms among civilians residing in armed conflictaffected *** This meta-analysis was conducted in accordance with the Preferred Reporting Items forSystematic Reviews and Meta-Analyses.A literature search employing MEDLINE(R),Embase Classic+Embase,APA PsyclNFO,Ovid Healthstar,Journal@Ovid Full Text,Cochrane,PTSDpubs and CINAHL was conducted from inception until 19 March 2024 to identify relevant *** assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Prevalence Studies,and a Comprehensive Meta-Analysiswas usedto conduct the statistical *** The search yielded 38595 articles,of which 57 were considered eligible for *** included studies comprised data from 64596 *** estimated a prevalence of 23.70%(95%CI 19.50%to28.40%)forPTSD symptomsand 25.60%(95%Cl 20.70%to 31.10%)for depressive features among war-afflicted *** subgroup analysis based on time since the war and the country's economic status revealed the highest prevalence for both PTSD and depressive symptoms was present during the years of war and in low/*** The results of this study provide conclusive evidence of the detrimental impacts of armed conflict on mental health ***,it is crucial to emphasise the significance of both physical and mental health in the aftermath of war and take appropriate humanistic measures to overcome challenges in the management of psychiatric illnesses.

关键词： analysis stress armed

Discharging patients home from the intensive care unit:A new trend

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World Journal of Clinical Cases 2024年第23期12卷 5313-5319页

作者： Esraa M Hassan Abbas B Jama ahmed Sharaf Asim Shaikh Mohamad El Labban Salim Surani syed A Khan Department of Critical Care Medicine Mayo Clinic Health systemMankatoMN 56001United States Department of Internal Medicine Baptist Hospital of Southeast TexasBeaumontTX 77701United States Department of Medicine Aga Khan UniversityKarachi 74200SindhPakistan Department of Internal Medicine Mayo Clinic Health SystemMankatoMN 56001United States Department of Medicine and Pharmacology Texas A&M UniversityCollege StationTX 77843United States Department of Anaesthesiology Mayo Clinic Health SystemRochesterMN 55905United States

Discharging patients directly to home from the intensive care unit(ICU)is becoming a new *** review examines the feasibility,benefits,challenges,and considerations of directly discharging ICU *** analyzing available evidence and healthcare professionals'experiences,the review explores the potential impacts on patient outcomes and healthcare *** practice of direct discharge from the ICU presents both opportunities and *** it can potentially reduce costs,enhance patient comfort,and mitigate complications linked to extended hospitalization,it necessitates meticulous patient selection and robust post-discharge support *** this strategy successfully mandates the availability of home-based care services and a careful assessment of the patient's readiness for the *** critical evaluation of existing literature,this review underscores the significance of tailored patient selection criteria and comprehensive post-discharge support systems to ensure patient safety and optimal *** insights provided contribute evidence-based recommendations for refining the direct discharge approach,fostering improved patient outcomes,heightened satisfaction,and streamlined healthcare ***,the review seeks to balance patientcentered care and effective resource utilization within ICU discharge strategies.

关键词： Intensive care unit Critical care Early discharge Cost effective critical care Patient comfort Early recovery

Long-term outcomes of titanium-nitride-oxide coated stents and drug-eluting stents in acute coronary syndrome:A systematic review and meta-analysis

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World Journal of Cardiology 2024年第5期16卷 293-305页

作者： Muhammad ahmed Ali Fahim Afia Salman Hira Anas Khan syed Muhammad Hasan Muskan FatimaBhojani Sarah Aslam Amna Zia Ul Haq Vishal Reddy Bejugam Beena Muntaha Nasir Wajiha Gul Abdul Moeed Abdelrahman S Abdalla Muhammad Majid Muhammad Sohaib Asghar Md Al Hasibuzzaman Department of Internal Medicine Dow University of Health SciencesKarachi 74200Pakistan Department of Internal Medicine North Central Bronx HospitalBronxNY 10467United States Department of Urology Center for Academic MedicineStanford University School of MedicinePalo AltoCA 33872United States Department of Cardiovascular Imaging Cleveland ClinicClevelandOH 44195United States Division of Nephrology and Hypertension Mayo Clinic RochesterRochesterMN 55905United States Institute of Nutrition and Food Science University of DhakaDhaka 1000Bangladesh

BACKGROUND In severe cases of coronary artery disease,percutaneous coronary intervention provide promising *** stent used could be a drug-eluting stent(DES)or a titanium-nitride-oxide coated stent(TiNOS).AIM To compare the 5-year effectiveness and safety of the two stent *** The following systematic review and meta-analysis was conducted in accordance with the preferred reporting items for systematic reviews and meta-analysis guidelines,and PubMed/MEDLINE,Scopus,and Cochrane Central were searched from inception till August *** outcomes were major adverse cardiac events(MACE),cardiac death,myocardial infarction(MI),cardiac death or MI,and ischemia-driven total lesion revascularization(ID-TLR).RESULTS Four randomized controlled trials(RCT),which analyzed a sum total of 3045 patients with acute coronary syndrome(ACS)after a median follow-up time of 5 years were *** statistically insignificant,an increase in the ID-TLR was observed in patients receiving TiNOSs vs *** addition,MI,cardiac death and MI,and definite stent thrombosis(DST)were significantly decreased in the TiNOS *** analysis revealed no significant results with meta-regression presenting non-ST elevated MI(NSTEMI)as a statistically significant covariate in the outcome of *** TiNOS was found to be superior to DES in terms of MI,cardiac death or MI,and DST outcomes,however,the effect of the two stent types on ID-TLR and MACE was not significant.A greater number of studies are required to establish an accurate comparison of patient outcomes in TiNOS and DES.

关键词： Stents Drug-eluting Major adverse cardiac events All-cause death Meta-analysis

Prediction of pressure gradient and hold-up in horizontal liquid-liquid pipe flow

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Petroleum Science 2023年第6期20卷 3766-3782页

作者： syed Amjad ahmed Bibin John School of Mechanical Engineering Vellore Institute of TechnologyIndia Department of Mechanical Engineering C Abdul Hakeem College of Engineering&TechnologyIndia

This paper aims to propose correlations to predict pressure gradient,friction factor and fluid phase hold-up in liquid-liquid horizontal pipe *** develop the correlations,experiments are conducted using high viscous oils(202 and 630 mPa⋅s)in a steel pipe of length 11.25 m and length-to-diameter ratio of *** addition,the experimental data from the literature comprising wide range of flow and fluid properties is *** the analysis,the liquid-liquid pipe flow data is categorized into two as:stratified and *** existing friction factor correlations are modified to incorporate the effects of viscosity of the oil phase,interfacial curvature(contact/wetting angle-in lieu of material of the pipe)and fluid phase *** the two-fluid model of stratified flow,the wall stress and interfacial stress correlations are substituted with superficial velocities of fluids and superficial Reynolds numbers of fluid phases replacing fluid phase velocities and fluid Reynolds ***,for dispersed flow,an effective Reynolds number is described as the sum of superficial Reynolds number of oil and water *** the generally employed mean or mixture Reynolds number with the effective Reynolds number into the existing single-phase turbulent flow friction factor correlation,an effective friction factor for oil-water flow is *** the proposed correlations,the pressure gradient across the oil-water flow and hold-up volume fraction are predicted with significant reduction in error compared with that of conventionally employed *** average error and standard deviation values of−7.06%,20.72%and 0.31%,18.79%are found for stratified flow and dispersed flow respectively.

关键词： oil-water flow two-fluid model pressure gradient stratified flow dispersed flow

Survey and technological analysis of laser and its defense applications

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Defence Technology（防务技术） 2021年第2期17卷 583-592页

作者： syed Affan ahmed Mujahid Mohsin syed Muhammad Zubair Ali Department of Avionics Engineering-College of Aeronautical Engineering(CAE) National University of Sciences and Technology(NUST)RisalpurKPKPakistan

The laser technology has made remarkable progress over the past couple of *** is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military *** to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive *** modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground ***,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial ***,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical ***,the developments in space sciences and laser technology have given synergistic potential outcomes to use laser systems in space *** paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in ***,a detailed analysis has been done on recent advancements of the laser technology for target indicators and *** also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and advancements in the domain of high energy directed laser weapons that have revolutionized the evolving military *** offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.

关键词： Laser systems Laser military applications Directed energy weapons Non-lethal weapons Laser military projects Survey Taxonomy