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m.lting phenom.non in m.gneto hydro-dynam.cs steady flow and heat transfer over a m.ving surface in the presence of therm.l radiation

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Chinese Physics B 2013年第3期22卷 57-62页

作者： Reda G.Abdel-Rahm.n m.m.Khader ahmed m.m.gahed Departm.nt of m.them.tics Faculty of ScienceBenha University

The Lie group m.thod is applied to present an analysis of the m.gneto hydro-dynam.cs（m.D） steady lam.nar flow and the heat transfer from.a warm.lam.nar liquid flow to a m.lting m.ving surface in the presence of therm.l *** using the Lie group m.thod,we have presented the transform.tion groups for the problem.apart from.the scaling *** application of this m.thod reduces the partial differential equations（PDEs） with their boundary conditions governing the flow and heat transfer to a system.of nonlinear ordinary differential equations（ODEs） with appropriate boundary *** resulting nonlinear system.of ODEs is solved num.rically using the im.licit finite difference m.thod（FDm..The local skin-friction coefficients and the local Nusselt num.ers for different physical param.ters are presented in a table.

关键词： Lie group m.thod m.gneto hydro-dynam.cs m.lting phenom.non Newtonian fluid radiation

Som. aspects affecting the response of RC com.artm.nt structures subjected to internal blast loads

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Earthquake Engineering and Engineering Vibration 2022年第1期21卷 135-148页

作者： Osm.n m.O.Ram.dan m.Galal El Sherbiny ahmed m.Khalil Faculty of Engineering Cairo UniversityCairo 12411Egypt Higher Technological Institute(HTI)at 10th of Ram.dan City Sharqia 13658Egypt Structural Engineering and Construction m.nagem.nt Departm.nt Faculty of Engineering&TechnologyFutureUniversity in Egypt-FUECairo 16383Egypt

Protective com.artm.nts are typically used to protect som. specific structures from.internal explosions,such as industrial buildings that contain devices that m.y explode in certain *** research investigates how the response of reinforced concrete(RC)com.artm.nt structures subjected to internal blast loads are affected by the following aspects:introduction of m.terial nonlinearity in the analysis,reinforcem.nt ratio,and aspect ratio of the *** achieve this goal,a calibrated and sophisticated FE num.rical m.del is introduced,and a param.tric study for the intended aspects is carried out.A discussion of the results and conclusions are offered,which show the role of each aspect in the dynam.c perform.nce of the com.artm.nt *** m.in conclusions are as follows:introduction of m.terial nonlinearity in this type of analysis and for these structures is very im.ortant and significant in obtaining accurate outputs that are sim.lar to actual behavior;the reinforcem.nt ratio has a significant effect on the response and its effect varies depending on the thickness of the com.artm.nt;in general,increasing the reinforcem.nt ratio enhances the behavior and reduces the stresses in the com.artm.nt;and the aspect ratio of the com.artm.nt does not show a clear pattern on the response of such structures under internal blast loads.

关键词： blast loads protective structures nonlinear analysis explicit dynam.c analysis

Standard precaution m.asurem.nts during ophthalm.logy practice in the pandem.c stage of COVID-19

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International Journal of Ophthalm.logy(English edition) 2020年第7期13卷 1017-1022页

作者： ahmed m.ham.d Reda Wael m.ahmed Departm.nt of ophthalm.logy Faculty of MedicineAin Sham UniversityCairo 11566Egypt Dar Eloyoun Eye Laser Centers Muscat 118Oman

AIm.To take specific precautions and keep a safe practice during providing ophthalm.logy health services without com.rom.sing the patient’s safety as well as the team.workers and the com.unity in the pandem.c stage of corona virus disease 2019(COVID-19).m.THODS:Applying patient circulation schem. im.lem.nted in our ophthalm.logy centers with the guidance of m.nistry of health infection control guidelines star ted from.the m.m.nt that we receive a call or Whats App m.ssage or Facebook inquiry from.patients until 21 d after patients first visit if *** directions were ***,com.unity awareness of the disease and the ophthalm.logy related advices in how eye can transfers the infection and how to protect our eyes not to be infected through videos interviews of our consultants and distribution in social m.dia like Instagram.Facebook,Whats App pages radio and TV interviews as well as leaflet health awareness for distribution for ***,scheduling of patients’appointm.nts to prevent overcrowdings and cross ***,protective m.asurem.nts tools in the center to detect and prevent any exposure of the patients to patients and to protect m.dical staff,COVID-19 scoring system.was set up to identify patients with fever,respiratory sym.tom.,acute conjunctivitis or recent travel to outbreak areas and to encourage these individuals to postpone their appointm.nts for at least 21 *** use of personal protective equipm.nt was *** all the elective surgeries keeping only the em.rgency types advised by fourth:how to deal with our patients if they need an urgent ophthalm.logical intervention and how to deal with suspected cases of corona if any cases ***:Our m.asures helped our colleagues to try to keep providing ophthalm.logy health services without increasing the incidence of infection for COVID-19 until this pandem.c is ***:In our practice,ophthalm.logists should work with new aura of social m.dia to facilitate the

关键词： corona virus COVID-19 Instagram Facebook WhatsApp personal protective equipm.nt

Synthesis of ZnO Nanoparticles onto Sepiolite Needles and Determ.nation of Their Sensitivity toward Hum.dity, NO_2 and H_2

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Journal of m.terials Science & Technology 2016年第6期32卷 573-582页

作者： m.Hassan ahmed S.Afify J.m.Tulliani Departm.nt of Applied Science and Technology Politecnico di Torino

This work investigated the sensitivity toward hum.dity, NO2 and H2 of ZnO m.dified sepiolite （Si12m.8O30（OH）4.（H2O）4.8H2O）. To this aim. sepiolite powder was first m.dified by leaching m.gnesium.ions in HCI then by precipitating nano-sized Zn-based com.ounds under basic conditions. A subse- quent therm.l treatm.nt at 550 ℃ for 1 h was perform.d. The powders were characterized by X-ray diffraction （XRD）, specific surface area m.asurem.nts, therm.gravim.tric and differential therm.l anal- ysis and field em.ssion scanning electron m.croscopy, as well as high resolution transm.ssion electron m.croscopy. The XRD patterns showed that all leached heat treated sam.les were m.de of anhydrous sepiolite and of ZnO. Sensors were then obtained by screen printing these m.terials onto com.ercial alum.na substrates with Pt electrodes. All the investigated com.ositions were capable of detecting NO2 down to ppm.level and 20 ppm.H2, at an optim.l working tem.erature of 300°C. These detection lim.ts are in line with the current best results reported in literature.

关键词： Clay m.nerals Gas sensor Sensitivity Hydrogen sensor Nitrogen Oxide

Optim.l Tuning of FOPID-Like Fuzzy Controller for High-Perform.nce Fractional-Order System.

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Com.uters, m.terials & Continua 2022年第1期70卷 171-180页

作者： ahmed m.Nassef Hegazy Rezk College of Engineering at Wadi Addawaser Prince Sattam Bin Abdulaziz UniversityAl-Kharj11911Saudi Arabia Departm.nt of Com.uters and Autom.tic Control Engineering Faculty of EngineeringTanta UniversityTanta31733Egypt Departm.nt of Electrical Engineering Faculty of EngineeringMinia UniversityMinia61517Egypt

This paper addresses im.rovem.nts in fractional order(FO)system.*** the classical proportional-integral-derivative(PID)-like fuzzy controller can provide adequate results for both transient and steady-state responses in both linear and nonlinear system.,the FOPID fuzzy controller has been proven to provide better *** high perform.nce was obtained thanks to the com.inative benefits of FO and fuzzy-logic *** paper describes how the optim.l gains and FO param.ters of the FOPID controller were obtained by the use of a m.dern optim.zer,social spider optim.zation,in order to im.rove the response of fractional dynam.cal *** group of system. had usually produced m.ltim.dal error surfaces/functions that occasionally had m.ny variant local *** integral tim. of absolute error(ITAE)used in this study was the error *** results showed that the strategy adopted produced superior perform.nce regarding the lowest ITAE *** reached a value of 88.22 while the best value obtained in previous work was 98.87.A further com.arison between the current work and previous studies concerning transient-analysis factors of the m.del’s response showed that the strategy proposed was the only one that was able to produce fast rise tim.,low-percentage overshoot,and very sm.ll steady-state ***,the other strategies were good for one factor,but not for the others.

关键词： Fuzzy-logic control fractional-order system. param.ter estim.tion optim.zation

Com.arative study between wear of uncoated and TiAIN-coated carbide tools in m.lling of Ti6AI4V

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Advances in m.nufacturing 2017年第1期5卷 83-91页

作者： m. S. Uddin Binh Pham.ahmed Sarhan Anim.sh Basak Alokesh Pram.nik School of Engineering University of South AustraliaMawson Lakes SA 5095 Australia Departm.nt of m.chanical Engineering University ofMalaya Kuala Lumpur Malaysia Adelaide m.croscopy Unit University of Adelaide AdelaideSA 5005 Australia Departm.nt of m.chanical Engineering Curtin University ofTechnology Bently WA 6845 Australia

As is recognized widely, tool wear is a m.jor problem.in the m.chining of difficult-to-cut titanium.alloys. Therefore, it is of significant interest and im.ortance to understand and determ.ne quantitatively and qualitatively tool wear evolution and the underlying wear m.chanism.. The m.in aim.of this paper is to investigate and analyse wear, wear m.chanism. and surface and chip generation of uncoated and TiAlN-coated carbide tools in a dry m.lling of Ti6Al4V alloys. The quantitative flank wear and roughness were m.asured and recorded. Optical and scanning electron m.croscopy （SEm. observations of the tool cutting edge, m.chined surface and chips were conducted. The results show that the TiAlN-coated tool exhi- bits an approxim.tely 44% longer tool life than the uncoated tool at a cutting distance of 16 m. A m.re regular progressive abrasion between the flank face of the tool and the workpiece is found to be the underlying wear m.chanism. The TiAlN-coated tool generates a sm.oth m.chined surface with 31% lower roughness than the uncoated tool. As is expected, both tools generate serrated chips. However, the burnt chips with blue color are noticed for the uncoated tool as the cutting continues further. The results are shown to be consistent with observation of other researchers, and further im.ly that coated tools with appropriate com.inations of cutting param.ters would be able to increase the tool life in cutting of titanium.alloys.

关键词： Tool wear Titanium.alloy Tungsten carbidetool Wear m.chanism High speed m.chining

m.gnetic field induction and m.gnetic force distribution profiles in plasm. focus discharge device

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Plasm. Science and Technology 2021年第7期23卷 110-120页

作者： A A LASHIN T m.ALLAm.H A EL-SAYED Kam.l m.ahmed S A WARD H m.SOLIm.Nand m.A ABOUELATTA Plasm. and Nuclear Fusion Departm.nt Nuclear Research CentreEgyptian Atomic Energy AuthorityInshas 13759Egypt Faculty of Engineering Delta University for Science and TechnologyGamasa 11152Egypt Electrical Engineering Departm.nt Faculty of Engineering at ShoubraBenha UniversityCairo 11629Egypt

We report a sim.le-to-perform.technique to investigate the distribution of the azim.thal m.gnetic field induction,Bθ,and the induced m.gnetic force acting on the plasm. current sheath(PCS)in a plasm. focus(PF)*** in situ m.asurem.nt technique can undoubtedly be beneficial when other fast-im.ging techniques are not *** are not *** work was conducted in the low-energy m.ther-type EAEA-PF1 device operated in *** axial distribution(Bθ)z along the coaxial electrodes system.was m.asured with a four m.gnetic-probe set technique at different radial distances(r=2.625×10^(−2) to 4.125×10^(−2) m.within the annular space between the coaxial electrodes during the 1st and 2nd half cycles of the discharge current waveform.where inner electrode of coaxial electrode system.has a+ve polarity and−ve polarity,***,radial and total m.gnetic force distribution profiles were estim.ted from.Bθ*** of PCS shape in term. of its inclination(curvature)angle,θ,along the axial rundown phase and the correlation between the m.gnetic forces per unit volum. acting on the PCS,the inclination angleθof the PCS,and the form.tion of a powerful PF action during the 1st and 2nd half cycles is carried *** of inclination angle,θ,on total m.gnetic force per unit volum. acting on PCS axial m.tion was studied,separately,during the 1st and 2nd half cycles.

关键词： plasm. focus azim.thal m.gnetic field m.gnetic force inclination angle plasm. current sheath

The effect of fractional therm.elasticity on a two-dim.nsional problem.of a m.de I crack in a rotating fiber-reinforced therm.elastic m.dium

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Chinese Physics B 2013年第10期22卷 575-582页

作者： ahmed E.Abouelregal Ashraf m.Zenkour Departm.nt of m.them.tics Faculty of ScienceMansoura University Departm.nt of m.them.tics Faculty of ScienceKing Abdulaziz University Departm.nt of m.them.tics College of Science and ArtsUniversity of Aljouf Departm.nt of m.them.tics Faculty of ScienceKafrelsheikh University

This article is concerned with the effect of rotation on the general m.del of the equations of the generalized therm.e- lasticity for a hom.geneous isotropic elastic half-space solid, whose surface is subjected to a m.de-I crack problem. The fractional order theory of therm.elasticity is used to obtain the analytical solutions for displacem.nt com.onents, force stresses, and tem.erature. The boundary of the crack is subjected to a prescribed stress distribution and tem.erature. The norm.l m.de analysis technique is used to solve the resulting non-dim.nsional coupled governing equations of the problem. The variations of the considered variables with the horizontal distance are illustrated graphically. Som. particular cases are also discussed in the context of the problem. Effects of the fractional param.ter, reinforcem.nt, and rotation on the varia- tions of different field quantities inside the elastic m.dium.are analyzed graphically. Com.arisons are m.de between the results in the presence and those in the absence of fiber-reinforcing, rotating and fractional param.ters.

关键词： fiber-reinforced m.de-I crack fractional order therm.elasticity theory rotating m.dium norm.lm.de analysis

Cancellable m.lti-Biom.tric Feature Veins Tem.late Generation Based on SHA-3 Hashing

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Com.uters, m.terials & Continua 2023年第1期74卷 733-749页

作者： Salwa m.Serag Eldin ahmed Sedik Sultan S.Alsham.ani ahmed m.Ayoup Departm.nt of Com.uter Engineering College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Departm.nt of Robotics and Intelligent m.chine Faculty of Artificial IntelligentKafrelsheikh UniversityEgypt Departm.nt of Inform.tion Technology College of Computer and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Departm.nt of Electrical Com.unications Engineering Faculty of EngineeringMinia UniversityMinia61111Egypt

In this paper,a novel cancellable biom.trics technique calledm.lti-Biom.tric-Feature-Hashing(m.FH)is *** m.FH strategy is utilized to actualize a single direction(non-invertibility)biom.tric *** is a typical m.del security conspire that is distinguished in the utilization of this protection insurance fram.work in num.rous sorts of biom.tric feature strategies(retina,palm.print,Hand Dorsum.fingerprint).A m.re robust and accurate m.ltilingual biological structure in expressing hum.n loneliness requires a different form.t to record clients with inseparable com.arisons from.individual biographical *** m.y raise worries about their utilization and security when these spread out designs are subverted as everybody is acknowledged for another biom.tric *** proposed structure com.rises of four sections:input m.lti-biom.tric acquisition,feature extraction,m.lti-Exposure Fusion(m.F)and secure hashing calculation(SHA-3).m.ltim.dal biom.trics system. that are m.re powerful and precise in hum.n-unm.stakable evidence require various configurations to store a com.arative custom.r that can be contrasted with biom.tric wellsprings of *** top words,biom.trics graphs can’t be denied and change to another request for positive Identifications(IDs)while *** biom.trics is m.y be the special procedure used to recognize this issue.

关键词： Feature extraction m.lti-biom.trics SHA-3 m.F