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Fault Ride-Through(FRT)Behavior in VSC-HVDC as Key Enabler of Transmission Systems Using SCADA Viewer Software

Energy Engineering 2022年第6期119卷 2369-2406页

作者： Samuel Bimenyimana Chen Wang Godwin Norense Osarumwense Asemota Aphrodis Nduwamungu Francis Mulolani Jean De Dieu Niyonteze Shilpi Bora Chun-Ling Ho Noel Hagumimana Theobald Habineza waqar bashir Yiyi Mo Intelligence and Automation in Construction Provincial Higher-Educational Engineering Research Centre Huaqiao UniversityXiamen361021China African Centre of Excellence in Energy for Sustainable Development University of RwandaKigali4285Rwanda Fujian Province Key Laboratory of Automotive Electronics and Electric Drive Fujian University of TechnologyFuzhou350118China Department of Climate Change Observatory Secretariat Ministry of EducationKigali4285Rwanda School of Electrical Engineering and Automation Tianjin Polytechnic UniversityTianjin300000China Department of Electrical and Electronics Engineering Copperbelt UniversityKitwe23456Zambia Ajeenkya D Y PatilUniversity LohegaonPune412105India Carnegie Mellon University-Kigali Rwanda Campus Kigali4285Rwanda

The world’s energy consumption and power generation demand will continue to ***,the bulk of the energy resources needed to satisfy the rising demand is far from the load *** aforementioned requires long-distance transmission systems and one way to accomplish this is to use high voltage direct current(HVDC)transmission *** main technical issues for HVDC transmission systems are loss of synchronism,variation of quadrature currents,amplitude,the inability of station 1(rectifier),and station 2(inverter)to either inject,or absorb active,or reactive power in the network in any circumstances(before a fault occurs,during having a fault in network and after a fault cleared),and the variations of power transfer ***,faults impact power quality such as voltage dips and power line outage *** paper presents a method of overcoming the aforementioned technical issues using voltage-source converter(VSC)based HVDC transmission systems with SCADA VIEWER software and dynamic grid *** benefits include having a higher capacity transmission system and proposed best method for control of active and reactive power transfer *** results obtained using MATLAB validated the experimental results from SCADA Viewer *** results indicate that the station’s rectifier or inverter can either inject or absorb either active power or reactive power in any ***,the reverse power flow under different modes of operation can ride through *** a 100.0%power transfer rate,the rectifier injected 775.0 W into the *** a 0.0%power transfer rate,the rectifier injected 164.0 W into the *** a-100.0%rated power,the rectifier injected 1264.0 W into the network and direction was also changed.

关键词： Fault ride through capability dynamic grid fault simulator asymmetric components negative sequence control

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Experimental Study on Heat Storage Properties Comparison of Paraffin/Metal Foams Phase Change Material Composites

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Journal of Thermal Science 2024年第2期33卷 469-478页

作者： waqar AHMED Abid HUSSAIN Hanzla SHAHID Imran ALI Hafiz Muhammad ALI Department of Mechanical Engineering University of Engineering and TechnologyTaxila47080Pakistan Department of Mechanical Engineering Institute of Space TechnologyIslamabadPakistan Department of Mechanical Mechatronics and Manufacturing EngineeringUniversity of Engineering and Technology LahoreFaisalabad CampusPunjabPakistan Mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power Systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Heat storage properties of phase change materials(PCMs) are essential characteristics that perform a key role in thermal heat energy storage *** thermal properties of PCMs can be improved by developing metal foam/PCM *** addition of metal foam in PCMs has a significant effect on the thermal characteristics of *** this paper,the heat storage properties of two different metal foam/PCM composites were experimentally *** behavior of paraffin in metal foam(copper and iron-nickel)/paraffin composites concerning pure paraffin at a constant heat flux of 1000 W/m^(2) in three directions simultaneously(x,y,and z) was *** was infiltrated into copper and iron-nickel foams to develop composite materials which resulted in enhancing the thermal conductivity of the paraffin.A comparative analysis is made on the heat storage properties of paraffin in copper and iron-nickel foams/paraffin *** temperature distribution during the phase transition process is experimentally *** comparison indicates that temperature uniformity in copper foam/paraffin composite is better than in iron-nickel foam/paraffin composite and pure paraffin at the same heat *** results show that at heat flux of 1000 W/m^(2),the heat storage time for copper foam/paraffin composite is 20.63% of that of iron-nickel foam/paraffin composite.

关键词： heat storage capacity paraffin/metal foam composite temperature uniformity heat storage rate phase transition process

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Flexible pavement longitudinal joint quality evaluation using non-destructive testing

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Journal of Road Engineering 2024年第2期4卷 189-202页

作者： Hamad Bin Muslim Syed waqar Haider Lev Khazanovich Department of Civil and Environmental Engineering Michigan State UniversityEast LansingMI 48824USA Department of Civil and Environmental Engineering University of PittsburghPittsburghPA 15261USA

Longitudinal joint construction quality is critical to the life of flexible *** deteriorated longitudinal joints has become a challenge for many highway *** the joint's quality through better compaction during construction can help achieve flexible pavements with longer service lives and less *** quality control(QC)and quality assurance(QA)plans provide limited ***,the risk of missing areas with poor joint compaction is significant.A density profiling system(DPS)is a non-destructive alternative to conventional destructive evaluation *** can provide quick and continuous real-time coverage of the compaction during construction in *** paper presents several case studies comparing various types of longitudinal joints and demonstrating the use of DPS to evaluate the joint's compaction *** paper shows that dielectric measurements can provide valuable insight into the ability of various construction techniques to achieve adequate levels of compaction at the longitudinal *** paper proposes a dielectric-based longitudinal joint quality index(LJQI)to evaluate the relative compaction of the joint during *** also shows that adopting DPS for assessing the compaction of longitudinal joints can minimize the risk of agencies accepting poorly constructed joints,identify locations of poor quality during construction,and achieve better-performing flexible pavements.

关键词： Sustainable pavements Dielectric/density profiling system Quality assurance Non-destructive testing Asphalt longitudinal joint

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Electronic and thermoelectric properties of YbMg_(2)X_(2)(X=P,As,Sb,Bi)zintl compounds by first-principles method

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Journal of Rare Earths 2024年第1期42卷 147-154,I0006页

作者： Sajid Khan Dil Faraz Khan R.Neffati Tariq Usman Muhammad waqar Ahsraf Shamim Khan Saeed Ullah Jan G.Murtaza Department of Physics University of Science&Technology BannuBannu28100Pakistan Department of Physics Faculty of ScienceKing Khalid UniversityP.O.Box 9004AbhaSaudi Arabia Laboratoire de Physique de La Matiere Condensee Departement de PhysiqueFaculte des Sciences de TunisUniversite Tunis El ManarCampus Universitaire1060TunisTunisia Department of Physics Shaoxing UniversityShaoxing312000China Department of Mathematics&Natural Sciences Prince Mohammad Bin Fahd UniversityAlkhobar31952Saudi Arabia Materials Modeling Lab Department of PhysicsIslamia College Peshawar25120KhyberPakhtunkhwaPakistan

In this work the structural,electronic and thermoelectric properties of YbMg_(2)X_(2)(X=P,As,Sb,Bi)zintl compounds were investigated comprehensively using first principles *** electronic properties were studied using PBE GGA,TB-mBJ and hybrid(YS-PBE0)*** the structural parameters of optimized structures are in harmonious agreement to the available *** band structure study illustrates that the titled materials manifest metallic and semi metallic nature using PBE and TB-mBJ potentials while they show wide band gap semiconducting behavior by following hybrid(YS-PBE0)*** density of states(TDOS)and partial density of states(PDOS)were also calculated to glimpse the contribution of orbitals of atoms in the formation of *** properties were studied by using BoltzTraP2 code employed to *** get enormous values of Seebeck coefficient(S),power factor(PF)and thermoelectric figure of merit(ZT)for all the samples YbMg_(2)X_(2)(X=P,As,Sb,Bi),Moreover,the overwhelming transport properties for the titled compounds indicate the optimum level of carriers’concentration which pinpoints these materials to be better thermoelectrics in the 1-2-2 zintl family.

关键词： Zintl compounds Hybrid functional Band structure Thermoelectrics Rare earths

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Soil erosion susceptibility mapping of Hangu Region,Kohat Plateau of Pakistan using GIS and RS-based models

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Journal of Mountain Science 2024年第8期21卷 2547-2561页

作者： Fakhrul ISLAM Liaqat Ali WASEEM Tehmina BIBI waqar AHMAD Muhammad SADIQ Matee ULLAH Walid SOUFAN Aqil TARIQ Department of Geology Khushal Khan Khattak UniversityKarak 27200Pakistan Department of Geography Government College University FaisalabadPunjab 38000Pakistan Institute of Geology The University of Azad Jammu&KashmirMuzaffarabad 13100Pakistan Department of Earth Sciences Changan UniversityXi’an 710003China NCEG University of PeshawarPeshawar 25120Pakistan Faculty of Earth Sciences Geography and AstronomyUniversity of ViennaVienna 1090Austria Plant Production Department College of Food and Agriculture SciencesKing Saud UniversityRiyadh 11451Saudi Arabia Department of Wildlife Fisheries and AquacultureCollege of Forest ResourcesMississippi State UniversityMS 39762USA

Soil erosion is a crucial geo-environmental hazard worldwide that affects water quality and agriculture,decreases reservoir storage capacity due to sedimentation,and increases the danger of flooding and ***,this study uses geospatial modeling to produce soil erosion susceptibility maps(SESM)for the Hangu region,Khyber Pakhtunkhwa(KPK),*** Hangu region,located in the Kohat Plateau of KPK,Pakistan,is particularly susceptible to soil erosion due to its unique geomorphological and climatic ***,the Hangu region is characterized by a combination of steep slopes,variable rainfall patterns,diverse land use,and distinct soil types,all of which contribute to the complexity and severity of soil erosion *** factors necessitate a detailed and region-specific study to develop effective soil conservation *** this research,we detected and mapped 1013 soil erosion points and prepared 12 predisposing factors(elevation,aspect,slope,Normalized Differentiate Vegetation Index(NDVI),drainage network,curvature,Land Use Land Cover(LULC),rainfall,lithology,contour,soil texture,and road network)of soil erosion using GIS ***,GIS-based statistical models like the weight of evidence(WOE)and frequency ratio(FR)were applied to produce the SESM for the study *** SESM was reclassified into four classes,i.e.,low,medium,high,and very high *** results of WOE for SESM show that 16.39%,33.02%,29.27%,and 21.30%of areas are covered by low,medium,high,and very high zones,*** contrast,the FR results revealed that 16.50%,24.33%,35.55%,and 23.59%of the areas are occupied by low,medium,high,and very high ***,the reliability of applied models was evaluated using the Area Under Curve(AUC)*** validation results utilizing the area under curve showed that the success rate curve(SRC)and predicted rate curve(PRC)for WOE are 82%and 86%,respectively,while SRC and PRC for FR are 85%and 96%,res

关键词： Soil erosion Geospatial technology Statistical models Hangu Pakistan

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Deposition and electrical properties of cadmium telluride thin films by thermal vacuum evaporation technique

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材料科学与工程（中英文版） 2009年第10期3卷 11-17,34页

作者： Nazar Abbas Shah Manzar Abbas Muhammad bashir waqar Ahmad Adil Syed Muhammad Ashraf Atta Department of Physics COMSA TS Institute of Information Technology Islamabad 45320 Pakistan

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不同干扰方式对塔克拉玛干沙漠南缘荒漠植物的防风固沙效果的影响

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生态学杂志 2024年

作者：杜艺张玉林赵广兴丛孟菲董新平高艳菊张志浩 Islam waqar 曾凡江中国科学院新疆生态与地理研究所新疆荒漠植物根系生态与植被修复重点实验室中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室干旱区生态安全与可持续发展重点实验室新疆策勒荒漠草地生态系统国家野外科学观测研究站中国科学院大学新疆大学生态与环境学院

在荒漠和绿洲过渡带，防风固沙是解决荒漠化和沙漠化问题的重要手段之一。骆驼刺（Alhagi sparsifolia）是沙漠地区常见的一种荒漠深根植物，对防风固沙起到重要作用。当地居民不合理的利用方式导致骆驼刺植被遭受大面积的破坏。本试验... 详细信息

在荒漠和绿洲过渡带，防风固沙是解决荒漠化和沙漠化问题的重要手段之一。骆驼刺（Alhagi sparsifolia）是沙漠地区常见的一种荒漠深根植物，对防风固沙起到重要作用。当地居民不合理的利用方式导致骆驼刺植被遭受大面积的破坏。本试验以骆驼刺为研究对象，设置自然对照（control group， CK）、春季砍伐（cutting in spring， CS）、春季火烧（burning in spring， BS）、秋季砍伐（cutting in fall， CF）和洪水灌溉（flood water irrigation， FI）5个处理，研究不同干扰方式对骆驼刺生长特征及土壤风蚀的影响。结果表明，在经历13年后（2010—2023年），自然对照（CK）的株高和冠幅显著高于其他干扰方式，洪水灌溉后的多样性指数、均匀度指数和物种丰富度显著高于其他干扰方式。在不同干扰方式下，土壤的pH、电导率、全氮、全磷、全钾和速效磷差异不显著。洪水灌溉（FI）后的土壤速效氮显著低于自然对照（CK），而土壤有机碳和速效钾显著低于春季砍伐（CS）。春季火烧（BS）后的土壤风蚀高度显著低于其他干扰方式。土壤风蚀高度与植株的株高和冠幅呈显著正相关。研究结果为更好地保护和合理利用骆驼刺及其他荒漠植被资源提供科学依据。

关键词：荒漠植物物种多样性采伐方式形态特征

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Analysis of ancient Rongcharong landslide dam failure events in the Suwalong reach of the upper reaches of the Jinsha River

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Journal of Earth Science 2024年

作者： Yongchao Li Songfeng Guo Bowen Zheng Yu Zou Shengyuan Song Yiwei Zhang Jianhua Yan Muhammad Faisal waqar Khan Zada Shengwen Qi Jianping Chen Institute of Geology and Geophysics Chinese Academy of Sciences Innovation Academy for Earth Science Chinese Academy of Sciences College of Construction Engineering Jilin University College of Earth and Planetary Science University of Chinese Academy of Sciences School of City and Architecture Engineering Zaozhuang University School of Earth Sciences and Engineering Hohai University Geo-technical and Geo-Environmental Engineering Division National Engineering Service Pakistan

Active tectonic movements and geological disasters frequently occur in the upper reaches of the Jinsha River， increasing the likelihood of landslides obstructing the river. Taking the ancient Rongcharong landslide dam failure events in the Suwalong reach as an example， this paper first analyzes the accuracy and applicability of the commonly used methods in calculating the peak flow of the dam failure， such as the empirical formula， the numerical method based on the physical mechanism， and the computational fluid dynamics (CFD) method. Then， the peak flood flow of the Rongcharong-dammed lake when it overflows the dam is determined to be 28393～64272m3/s. At the same time， the failure process of landslide dam due to flood erosion was elucidated using the CFD method， which can be divided into three stages: gradual erosion in the initial stage， rapid development in the middle stage， and gradual expansion in the final stage. Finally， the factors that affect the peak flow of floods are analyzed， and suggestions for emergency treatment of landslide dams are put forward. The findings of this research can serve as a valuable reference for disaster prevention and mitigation strategies to adapt to the increasing frequency of landslide-induced river blockages.

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刈割对豆科和非豆科植物叶片内稳性及叶片土壤化学计量特征的影响

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草地学报 2024年第5期32卷 1513-1521页

作者：杜艺宋佼阳张玉林柴旭田张志浩 ISLAM waqar 曾凡江中国科学院新疆生态与地理研究所新疆荒漠植物根系生态与植被修复重点实验室新疆乌鲁木齐830011 中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室干旱区生态安全与可持续发展重点实验室新疆乌鲁木齐830011 新疆策勒荒漠草地生态系统国家野外科学观测研究站新疆策勒848300 中国科学院大学北京100049 新疆大学生态与环境学院新疆乌鲁木齐830046

为了明确豆科和非豆科植物在生长发育过程中养分利用策略的差异。本试验以典型豆科植物苜蓿(Medicago sativa)和非豆科植物菊苣(Cichorium intybus)为研究对象。分别于2021年7月14日(播种后第60 d)、2021年8月3日(播种后第80 d)和2021年... 详细信息

为了明确豆科和非豆科植物在生长发育过程中养分利用策略的差异。本试验以典型豆科植物苜蓿(Medicago sativa)和非豆科植物菊苣(Cichorium intybus)为研究对象。分别于2021年7月14日(播种后第60 d)、2021年8月3日(播种后第80 d)和2021年8月24日(播种后第100 d)采集地上部分和土壤样品,计算生态化学计量内稳性。结果表明:2种植物叶片氮钾比在播种后第80 d刈割显著高于播种后第100 d刈割,而叶片磷钾比表现相反趋势(PH K>H P,表明植物对氮元素的调控能力更强。这项研究发现叶片化学计量特征存在物种间差异,这种差异是物种对环境长期适应的结果,与自身遗传特征有关,具有相对稳定性,并非全部受制于土壤养分的影响。

关键词：生态化学计量植物养分内稳性指数土壤特性

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Designing Bayesian Two-Sided Group Chain Sampling Plan for Gamma Prior Distribution

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Computer Systems Science & Engineering 2023年第2期44卷 1069-1079页

作者： waqar Hafeez Nazrina Aziz School of Quantitative of Sciences Universiti Utara MalaysiaSintok06010Malaysia Institute of Strategic Industrial Decision Modelling(ISIDM) Universiti Utara MalaysiaSintok06010Malaysia

Acceptance sampling is used to decide either the whole lot will be accepted or rejected,based on inspection of randomly sampled items from the same *** an alternative to traditional sampling plans,it is possible to use Baye-sian approaches using previous knowledge on process *** study pre-sents a Bayesian two-sided group chain sampling plan(BTSGChSP)by using various combinations of design *** BTSGChSP,inspection is based on preceding as well as succeeding *** function is used to derive the probability of lot acceptance based on defective and non-defective *** distribution is considered as a suitable prior for Poisson *** quality regions are found,namely:(i)quality decision region(QDR),(ii)probabil-istic quality region(PQR),(iii)limiting quality region(LQR)and(iv)indifference quality region(IQR).Producer’s risk and consumer’s risk are considered to esti-mate the quality regions,where acceptable quality level(AQL)is associated with producer’s risk and limiting quality level(LQL)is associated with consumer’s ***,AQL and LQL are used in the selection of design parameters for *** values based on all possible combinations of design parameters for BTSGChSP are presented and inﬂection points’values are ***ﬁnding exposes that BTSGChSP is a better substitute for the existing plan for industrial practitioners.

关键词： Bayesian acceptance sampling poisson distribution gamma distribution producer’s risk consumer’s risk

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