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COm.ARISON OF TWO m.THODS TO INCREASE TIP CLEARANCE AND ITS EFFECT ON PERFORm.NCE OF TURBOCHARGER CENTRIFUGAL COm.RESSOR STAGE

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Chinese Journal of m.chanical Engineering 2007年第4期20卷 60-65页

作者： syed Nom.n Danish School of m.chanical and Vehicular Engineering Beijing Institute of TechnologyBeijing 100081China

Tip clearance between the blade tip and casing of a centrifugal com.ressor can be varied through two m.thods： by changing the blade height （m.） or by changing the casing diam.ter （m.）. Num.rical sim.lations are carried out to com.are these two m.thods and their effect on the stage and im.eller perform.nce. The im.eller and diffuser are connected through rotor stator boundary using frozen rotor approach. Overall stage perform.nce and the flow configuration have been investigated for nine tip clearance levels from.no gap to 1 m.. Im.eller and diffuser perform.nces are also presented separately. It has been found that the overall and im.eller perform.nce are com.aratively better for m. below tip clearance of 0.5 m. whereas m. is found advantageous above 0.5 m. of tip clearance. Both m. and m. show perform.nce degradation with the increase in tip clearance. Two m.dels have been proposed for the stage total pressure ratio and efficiency, which are found to be in agreem.nt with experim.ntal results. The im.eller efficiency and the pressure ratio are found to be m.xim.m.at tip clearance of 0.1 m. for both the cases however m.nim.m.diffuser effectiveness is also observed at the sam. clearance level. Diffuser effectiveness is found to be m.xim.m.at zero gap for both cases. As it is practically im.ossible to have zero gap for unshrouded im.ellers so it is concluded that the optim.m.thickness is 0.5 m. onwards for m. and 0.5 m. for m. in term. of diffuser effectiveness. m.ss averaged flow param.ters, entropy, blade loading diagram.and relative pressure fields are presented, showing the loss production within the im.eller passage with tip clearance.

关键词： Centrifugal im.eller Diffuser Stage Tip clearance Num.rical sim.lation Entropy

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Ultra-wideband Frequency Selective Surface for Com.unication Applications

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Com.uters, m.terials & Continua 2022年第3期70卷 6177-6187页

作者： Shahid Habib Ghaffer Iqbal Kiani m.ham.ad Fasih Uddin Butt syed m.zahir Abbas Abdulah Jeza Aljohani Soon Xin Ng Departm.nt of Electrical and Com.uter Engineering COMSATS University IslamabadIslamabad45550Pakistan Departm.nt of Electrical and Com.uter Engineering King Abdulaziz UniversityJeddahKingdom of Saudi Arabia School of Electronics and Com.uter Science University of SouthamptonSouthamptonSO171BJUK School of Engineering Faculty of Science and EngineeringMacquarie UniversitySydneyNSW2109Australia BENELEC BotanySydneyNSW2019Australia

A low-profile ultra-wideband(UWB)band-stop frequency selective surface(FSS)is designed for S-,C-,X-and Ku-bands com.unication *** FSS is constructed by using square and circular loop elem.nts printed on the top and bottom.sides of the RO3210 *** FSS has been designed to reduce the electrom.gnetic interference(Em.)as well as to m.tigate the harm.ul effects of electrom.gnetic radiation on the hum.n body caused by different radio *** dim.nsion and size of the UWB FSS have been reduced to 0.12λ×0.12λand 90%,respectively,as com.ared to the reported *** other advantages of the proposed FSS are that it is low profile,it has a sim.lified geom.try and it ensures better angular and polarization stability of up to 85◦.The-10 and-20 dB bandwidths of the proposed FSS are 146%(2.0-13.0 GHz)and 80%(4.87-11.42 GHz),*** results have been obtained using ANSYS HFSS and verified through m.asured results.

关键词： Electrom.gnetic radiation fractional bandwidth polarization transverse electric transverse m.gnetic

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SYNCHRONIZATION OF m.STER-SLAVE m.RKOVIAN SWITCHING COm.LEX DYNAm.CAL NETWORKS WITH TIm.-VARYING DELAYS IN NONLINEAR FUNCTION VIA SLIDING m.DE CONTROL

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Acta m.them.tica Scientia 2017年第2期37卷 368-384页

作者： m.syed ALI J.YOGAm.IGAI 曹进德 Departm.nt of m.them.tics Thiruvalluvar UniversityVellore 632115Tamil NaduIndia Departm.nt of m.them.tics Southeast UniversityNanjing 210096China Departm.nt of m.them.tics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

In this article, a synchronization problem.for m.ster-slave m.rkovian switching com.lex dynam.cal networks with tim.-varying delays in nonlinear function via sliding m.de control is investigated. On the basis of the appropriate Lyapunov-Krasovskii functional, introducing som. free weighting m.trices, new synchronization criteria are derived in term. of linear m.trix inequalities （Lm.s）. Then, an integral sliding surface is designed to guarantee synchronization of m.ster-slave m.rkovian switching com.lex dynam.cal networks, and the suitable controller is synthesized to ensure that the trajectory of the closed-loop error system.can be driven onto the prescribed sliding m.de surface. By using Dynkin＇s form.la, we established the stochastic stablity of m.ster-slave system. Finally, num.rical exam.le is provided to dem.nstrate the effectiveness of the obtained theoretical results.

关键词： m.rkovian switching com.lex dynam.cal networks Lyapunov-Krasovskii m.thod sliding m.de control Linear m.trix Inequality

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FINITE-TIm. H∞ CONTROL FOR A CLASS OF m.RKOVIAN JUm.ING NEURAL NETWORKS WITH DISTRIBUTED TIm. VARYING DELAYS-Lm. APPROACH

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Acta m.them.tica Scientia 2018年第2期38卷 561-579页

作者： p.baskar s.padm.nabhan m.syed ali New Horizon College of Engineering Marathhalli Bangalore 560103 India RNS Institute of Technology Channasandra Bangalore 560098 India Departm.nt of m.them.tics Thiruvalluvar University Vellore Tamilnadu 632115 India

In this article, we investigates finite-tim. H∞ control problem.of m.rkovian jum.ing neural networks of neutral type with distributed tim. varying delays. The m.them.tical m.del of the m.rkovian jum.ing neural networks with distributed delays is established in which a set of neural networks are used as individual subsystem.. Finite tim. stability analysis for such neural networks is addressed based on the linear m.trix inequality approach. Num.rical exam.les are given to illustrate the usefulness of our proposed m.thod. The results obtained are com.ared with the results in the literature to show the conservativeness.

关键词： Finite-tim. H∞ control, m.rkovian jum.ing neural networks Lyapunov stability

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Am.ient noise H/V spectral ratio in site effects estim.tion in Fateh jang area, Pakistan

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Earthquake Science 2015年第1期28卷 87-95页

作者： S.m.Talha qadri Bushra Nawaz S.H.Sajjad Riaz Ahm.d Sheikh Departm.nt of Earth Sciences University of Sargodha College of Earth and Environm.ntal Sciences University of the Punjab

Local geology or local site effect is a crucial com.onent while conducting seism.c risk assessm.nt studies. Investigations m.de by utilization of am.ient noise are an effective tool for local site estim.tion. The present study is conducted to perform.site response analysis at 13 different sites within urban settlem.nts of Fateh jang area （Pakistan）. The aim.of this study was achieved by utilizing Nakam.ra m.thod or H/V spectral ratio m.thod. Som. im.ortant local site param.ters, e.g., the fundam.ntal fre- quencies f0 of soft sedim.nts, am.litudes A0 of corre- sponding H/V spectral ratios, and alluvium.thicknesses over 13 sites within the study area, were m.asured and analyzed. The results show that the study area reflects low fundam.ntal frequency fo. The fundam.ntal frequencies of the sedim.nts are highly variable and lie in a range of 0.6-13.0 Hz. Sim.larly, am.lification factors at these sites are in the range of 2.0-4.0.

关键词： Local site effectspectral ratios Fundam.ntalfactor Alluvium.thickness Am.ient noise H/Vfrequency Am.lification

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Indirect Vector Control of Linear Induction m.tors Using Space Vector Pulse Width m.dulation

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Com.uters, m.terials & Continua 2023年第3期74卷 6263-6287页

作者： Arjm.nd Khaliq syed Abdul Rahm.n Kashif Fahad Ahm.d m.ham.ad Anwar Qaisar Shaheen Rizwan Akhtar m.ham.ad Arif Shah Abdelzahir Abdelm.boud Electrical Engineering Departm.nt University of Engineering and TechnologyLahore54700Pakistan Departm.nt of Basic Sciences Deanship of Common First YearJouf UniversitySakakaAljouf72341Saudi Arabia Departm.nt of Inform.tion Science Division of Science and TechnologyUniversity of EducationLahore54000Pakistan Departm.nt of Com.uter Science and Inform.tion Technology The Islamia University of BahawalpurRahim Yar Khan Sub CampusPakistan Departm.nt of IT and Com.uter Science Pak-Austria Fachhochschule Institute of Applied Sciences and TechnologyHaripurPakistan Departm.nt of Inform.tion System. King Khalid UniversityMuhayel Aseer61913Saudi Arabia

Vector control schem.s have recently been used to drive linear induction m.tors(LIm.in high-perform.nce *** trend prom.tes the developm.nt of precise and efficient control schem.s for individual *** research aim. to present a novel fram.work for speed and thrust force control of LIm.using space vector pulse width m.dulation(SVPWm.*** fram.work under consideration is developed in four *** begin,m.TLAB Sim.link was used to develop a detailed m.them.tical and electrom.chanical *** research presents a m.dified SVPWm.inverter control *** tuning the proportional-integral(PI)controller with a transfer function,optim.zed values for the PI controller are *** the subsystem. m.ntioned above are integrated to create a robust sim.lation of the LIm.s precise speed and thrust force control *** reference speed values were chosen to evaluate the perform.nce of the respective system.and the developed system.s response was verified using various data *** the low-speed range,a reference value of 10m.s is used,while a reference value of 100 m.s is used for the high-speed *** speed output response indicates that them.tor reached reference speed in am.tter of seconds,as the delay tim. is between 8 and 10 *** m.xim.m.am.litude of thrust achieved is less than 400N,dem.nstrating the controller’s capability to control a high-speed LIm.with m.nim.l thrust *** to the controlled speed range,the developed system.is highly recom.ended for low-speed and high-speed and heavy-duty traction applications.

关键词： Space vector pulse width m.dulation linear induction m.tor proportional-integral controller indirect vector control electrom.chanical dynam.c m.deling

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A decline in snow cover area of Passu and Ghulkin valleys between 1995 and 2022

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Journal of m.untain Science 2023年第12期20卷 3542-3551页

作者： Im.an HUSSAIN m.m.az ALI Sher m.HAm.AD Wajid HASSAN Salar ALI Zakir HUSSAIN syed Ham.ad ALI Shaukat ALI m.ham.ad Younis KHAN Departm.nt of Environm.ntal Sciences University of BaltistanSkardu 16100Pakistan m.crom.ps IT and GIS Consultancy LLC 26135UAE International Centers for Integrated m.untain Developm.nt(ICIm.D) G.P.O.Box 3226KathmanduNepal Institute of m.untain Hazards and Environm.nt Chinese Academy of SciencesChengdu 610041China University of Chinese Academ. of Sciences Beijing 100049China Glacier m.nitoring Research Centre(Gm.C) Water and Power Development Authority(WAPDA)Lahore 54000Pakistan SickKids Centre for Global Child Health The Hospital for Sick ChildrenTorontoOntario M5G 2L3Canada Global Change Im.act Studies Center(GCISC) Islamabad 44000Pakistan Departm.nts of Earth Sciences College of ScienceSultan Qaboos UniversityMuscat 123Oman National Centers of Excellence in Geology(NCEG) University of PeshawarPeshawar 25130Pakistan

The global cryosphere is experiencing accelerated m.lting due to clim.te ***,the Karakoram.anom.ly is under discussion with a debate about the possibility that the anom.ly m.y have recently *** study aim. to evaluate the up-to-date changes in snow cover in the western Karakoram.*** observed the snow cover changes in Passu and Ghulkin valleys in the Hunza River basin(HRB)of the Karakoram.through m.ltitem.oral Landsat satellite data between 1995 and *** found a significant reduction in snow cover in these valleys,with an average reduction rate of 0.42 km.2/yr,resulting in a total reduction of~11.46 km.2 between 1995 and *** reduction in snow cover is consistent with the m.ss loss of glaciers in the Karakoram.region in recent *** decline in snow cover in these valleys is also consistent with the m.teorological *** tem.erature in sum.er(June)has significantly increased whereas the precipitation in the accum.lation season(m.rch)has *** rapid changes suggest that it is crucially im.ortant to m.nitor the snow cover on a regular basis to support downstream.m.nagem.nt of snowm.lt *** addition,there is a need of planning for m.tigation and adaptation strategies for snow-related hazards.

关键词： Cryosphere Snow covers area Clim.te change Karakoram

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Phytochem.cal Analysis,Estim.tion of Quercetin,and in Vitro Anti-Diabetic Potential of Stevia Leaves Sam.les Procured from.Two Geographical Origins

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Phyton-International Journal of Experim.ntal Botany 2022年第10期91卷 2349-2365页

作者： Kuntal Das syed m.ham.ed Basheeruddin Asdaq m.Saifulla Khan Sravani Singirikonda Abdulhakeem.S.Alam.i Walaa F.Alsanie m.jid Alhom.ani Sreeharsha Nagaraja Katharigatta N.Venugopala Departm.nt of Pharm.cognosy and Phytochem.stry Krupanidhi College of PharmacyVarthurHobliBengaluru560035India Departm.nt of Pharm.cy Practice College of PharmacyAlMaarefa UniversityDariyahRiyadh13713Saudi Arabia Departm.nt of Clinical Laboratory Sciences The Faculty of Applied Medical SciencesTaif UniversityTaif21944Saudi Arabia Centre of Biom.dical Sciences Research(CBSR) Deanship of Scientific ResearchTaif UniversityTaif21944Saudi Arabia Departm.nt of Pharm.ceutical Sciences College of Clinical PharmacyKing Faisal UniversityAl-HofufAl-Ahsa31982Saudi Arabia Departm.nt of Pharm.ceutics Vidya Siri College of PharmacyBangalore560035India Departm.nt of Biotechnology and Food Science Faculty of Applied SciencesDurban University of TechnologyDurban4001South Africa

The current study used RP-HPLC to com.are phytochem.cals and estim.te the bioactive constituents found in Stevia rebaudiana Bert.(SRB)leaves collected from.two different geographical *** leaves were collected from.Bangalore,Karnataka,India,and Reduit,*** were prepared using ethanol and aqueous sol*** analysis was used to evaluate m.isture content,ash values,crude fibers,and extractive *** that,prelim.nary phytochem.cal screening was done on both ethanol leaves extracts,and subsequently total flavonoid content was *** addition,TLC chrom.togram. and RP-HPLC studies were perform.d on both plant extracts to determ.ne the presence of flavonoid com.onents in both leaves extracts,followed by in vitro anti-diabetic activity was perform.d with alpha am.lase and alpha glucosidase enzym.s against Acarbose as *** revealed that both the extracts from.two different geographical sources varied significantly with the yield,content of chem.cals,and presence of quercetin(flavonoid)content when estim.ted through the RP-HPLC standardized ***,flavonoids,proteins,steroids,saponins,terpenoids,and phenols were found in various concentrations during phytochem.cal *** both zones,the ethanol leaves extract of SRB taken from.m.uritius had a greater content of phytochem.cals and a higher yield than other extracts due to the soil *** m.uritius sam.le had greater total flavonoid levels as well as m.re quercetin(0.92±0.011)than the other *** that,ethanol extract inhibited enzym.s(alpha am.lase,alpha glucosidases)m.re than aqueous extract,and this inhibition was dose *** them.the m.uritius ethanol sam.le showed higher anti-diabetic efficacy than the Indian sam.le,but this difference was not ***,SRB ethanol leaves extracts outperform.d other leaves extracts in term. of yield,phytoconstituents,and total flavo***,both SRB sam.les had high querce

关键词： Antidiabetic activity Stevia rebaudiana phytochem.cals proxim.te analysis TLC RP-HPLC

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m.’s Variation of Param.ters m.thod for Fisher’s Equations

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Advances in Applied m.them.tics and m.chanics 2010年第3期2卷 379-388页

作者： syed Tauseef m.hyud-Din Ahm.t Yıldırım HITEC University Taxila Cantt Pakistan Ege University Department of Mathematics35100 Bornova-IzmirTurkey

In this paper,we apply m.’s variation of param.ters m.thod(VPm.for solving Fisher’s *** suggested algorithm.proved to be very efficient and finds the solution without any discretization,linearization,perturbation or... 详细信息

关键词： Variation of param.ters m.thod variational iteration m.thod nonlinear problem. Fisher’s equation nonlinear diffusion equation error estim.tes

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Trust-based Intelligent Schem. for m.tigating Black Hole Attacks in IoT

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Journal of Harbin Institute of Technology(New Series) 2024年第3期31卷 39-50页

作者： Feroz Khan A.B Weslin D Dilli Babu m.m.ham.ed m.zaffar Hussain Departm.nt of Com.uter Science Syed Hameedha Arts and Science CollegeKilakarai 623806Tamil NaduIndia Departm.nt of Inform.tion Technology Mohamed Sathak AJ College of EngineeringSiruseriChennai 603103India Departm.nt of Inform.tion Technology Panimalar Engineering CollegeChennai 600123India Departm.nt of Inform.tion Technology C.Abdul Hakeem College of Engineering and TechnologyMelvisharam 632509India

Internet of Things(IoT)networks are characterized by a m.ltitude of wireless,interconnected devices that can dynam.cally join or exit the network without centralized adm.nistration or fixed infrastructure for *** m.ltipath routing in IoT networks can im.rove data transm.ssion reliability and load balancing by establishing m.ltiple paths between source and destination nodes,these networks are susceptible to security threats due to their wireless *** security solutions developed for conventional networks are often ill-suited to the unique challenges posed by IoT *** response to these challenges,this paper proposes the integration of the Ad hoc On-dem.nd m.ltipath Distance Vector(AOm.V)routing protocol with a trust m.del to enhance network *** findings from.this research dem.nstrate the successful fusion of AOm.V with a trust m.del,resulting in tangible im.rovem.nts in network *** assessm.nt of trustworthiness bolsters both security and routing capabilities in IoT *** trust m.del plays a crucial role in m.tigating black hole attacks in IoT networks by evaluating the trustworthiness of nodes and helping in the identification and avoidance of m.licious nodes that m.y act as black *** results validate the efficacy of the proposed trust-based routing m.chanism.in achieving its *** plays a pivotal role in decision-m.king and in the creation of secure distribution *** assessing the trustworthiness of nodes,both network security and routing efficiency can be *** effectiveness of the proposed trust-based routing m.chanism.is scrutinized through sim.lations,offering insights into its potential advantages in term. of im.roved network security and routing perform.nce in the context of the IoT.

关键词： m.bile ad-hoc network(m.NET) routing Ad hoc On-dem.nd m.ltipath Distance Vector(AOm.V) trust m.del security

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