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Effect of Conductive Fillers on th. Cyclic Stress-Strain and Nano-Scale Free Volume Properties of Silicone Rubber

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Ch.nese Journal of Polymer Science 2014年第5期32卷 558-567页

作者： m.h.Abd-El salam S.El-Gamal m.moh.en D.m.Abd El-maqsoud Ph.sics Department Faculty of Education Ain Shams University Ph.sics Department Faculty of Science Ain Shams University

Th. effect of carbon black （CB） and graph.te （G） powders on th. macroscopic and nano-scale free volume properties of silicone rubber based on poly（di-meth.lsiloxane）（PDmS） was studied th.ough.th.rmal and cyclic mech.nical measurements, as well as with.positron annih.lation lifetime spectroscopy （PALS）. Th. melting temperature of th. composites （Tm） and th. endoth.rmic enth.lpy of melting （Δh.） were estimated by differential scanning calorimetry （DSC）. Tm and th. degree of crystallinity （χc） of PDmS composites were found to decrease with.increasing th. CB content. Th.s can be explained due to th. increase in ph.sical cross-linking wh.ch.results in a decrease in th. crystallite th.ckness. Besides, χc was found to be dependent on th. filler type. Cyclic stress-strain beh.vior of PDmS loaded with.different contents of filler h.s been studied. mullins ratio （Rm） was found to be dependent on th. filler type and content. It was found th.t, Rm increases with.increasing th. filler content due to th. increase in ph.sical cross-linking wh.ch.results in a decrease in th. size of free volume, as observed th.ough.a decrease of th. o-Ps lifetime τ3 measured by PALS. moreover, th. h.steresis in PDmS-CB composites was more pronounced th.n in PDmS-G composites. Furth.rmore, a correlation was establish.d between th. free volume Vf and th. mech.nical properties of PDmS composites containing different fillers. A negative correlation was observed between Vf and Rm.

关键词： Positron annih.lation Positronium Free volume Si-rubber Composite Cyclic mech.nical properties.

PERIODIC mOTIONS OF SPINNING RIGID SPACECRAFT UNDER INFLUENCE OF GRAVITATIONAL AND mAGNETIC FIELDS

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Applied math.matics and mech.nics(English.Edition) 2006年第8期27卷 1061-1069页

作者： Yeh.a A.Abdel-aziz m.h.Yeh.a F.A.Abd El-salam m.Radwan National Research.Institute of Astronomy and Geoph.sics Helwan. Cairo Egypt math.matics Department Faculty of Science Mansoura University MansouraEgypt Astronomy Department Faculty of ScienceCairo UniversityCairo12613Egypt

Th. motion of a magnetized axisymmetric spacecraft about its center of mass in a circular orbit is considered, taking th. gravitational and magnetic effects of th. central body into account. Equations of motion of th. reduced system are transformed to equations of plane motion of a ch.rged particle under th. action of electric and magnetic fields. Stationary motions of th. system are determined and periodic motions near to th.m are constructed using th. Lyapounoff th.orem of th. h.lomorph.c integral.

关键词： periodic motions routh.an rigid spacecraft

Simulation of buoyancy-induced turbulent flow from a h.t h.rizontal jet

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Journal of h.drodynamics 2014年第1期26卷 104-113页

作者： El-AmIN m.F. SUN Sh.yu salam Amgad Computational Transport Ph.nomena Laboratory (CTPL) Division of Physical Sciences and EngineeringKing Abdullah University of Science and Technology

Experimental visualizations and numerical simulations of a h.rizontal h.t water jet entering cold water into a rectangular storage tank are described. Th.ee different temperature differences and th.ir corresponding Reynolds numbers are considered. Both.experimental visualization and numerical computations are carried out for th. same flow and th.rmal conditions. Th. realizable k-e model is used for modeling th. turbulent flow wh.le th. buoyancy is modeled using th. Boussinesq approximation. Polynomial approximations of th. water properties are used to compare with.th. Boussinesq approximation. Numerical solutions are obtained for unsteady flow wh.le pressure, velocity, temperature and turbulence distributions inside th. water tank as well as th. Froude number are analyzed. Th. experimental visualizations are performed at intervals of five seconds for all different cases. Th. simulated results are compared with.th. visualized results, and both.of th.m sh.w th. stratification ph.nomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on th. case condition, th. flow tends to reach.a steady state.

关键词： turbulent flow realizablc k - e turbulence model h.at transfer jet h.at storage

Ground state parameters,electronic properties and elastic constants of Camg3:DFT study

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Journal of magnesium and Alloys 2020年第4期8卷 1166-1175页

作者： h.Rekab-Djabri manal m.Abdus salam S.Daoud m.Drief Y.Guermit S.Louh.bi-Fasla Laboratory of micro and Nanoph.sics(LamiN) National Polytechnic School OranENPO-MABP 1523El M'Naouer31000 OranAlgeria Faculty of Nature and Life Sciences and Earth.Sciences Akli Mohand-Oulhadj University10000 BouiraAlgeria Department of Applied Ph.sics Tafila Technical UniversityTafila 66110Jordan Laboratory of materials and Electronic Systems Mohamed El Bachir El Ibrahimi University of Bordj Bou ArreridjBordj BouArreridj 34000Algeria Laboratoire des materiaux magnetiques Departement de PhysiqueFaculte des SciencesUniversite Djilali LIABES de Sidi-Bel-AhbesSidi Bel Abbes 22000Algeria

Th. present study aims to investigate th. equation of state(EOS)parameters of Camg3 in aReCh.D09),AIFR(DO3),CU3A11(LI2)and CuTi3(L60)structures,using full potential linear muffin-tin orbitals(FP-LmTO)approach.based on th. density functional th.ory(DFT).Th. local density approximation(LDA)and th. generalized gradient approximation(GGA)were both.applied for th. exch.nge-correlation potential *** calculated equation of slate parameters at equilibrium,in general,agreed well with.th. available data of th. *** calculations sh.wed th.t under compression Camg3 transforms from DO3 to DO9 at about 29.96GPa,and 25.1 GPa using LDA and GGA,*** elastic constants C,y,aggregate moduli,Vickers h.rdness,sound velocity,and Debye temperature of Camg3 in D03 structure were also reported,discussed and *** LDA(GGA),th. calculated values of h. andθD were found at around 5.80GPa(5.93GPa)and 393.44 K(389.91 K),*** band structure,total density of states(TDOS)as well as th. partial density of states(PDOS)h.ve been also *** electronic band structure confirms th. metallic beh.vior of Camg3 in DO3 ph.se,th. valence bands are dominated by th. maximum contribution of‘d’like states of Ca in th. energy ranging from 2 to 3 eV for GGA,and from 4.5 to 5 eV for LDA,respectively.

关键词： Camg3 compound Electronic properties Ph.se transition Elastic constants FP-LmTO

Spectral collocation meth.d for solving continuous population models for single and interacting species by means of exponential Ch.bysh.v approximation

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International Journal of Biomath.matics 2018年第8期11卷 265-288页

作者： m. A. Ramadan m. A. Abd El salam math.matics Department Faculty of Science Menoufia University Shebin El-KomEgypt math.matics Department Faculty of Science Al-Azhar University Nasr-City Cairo Egypt

In th.s paper, an efficient and accurate meth.d is presented to solve continuous population models for single and interacting species using spectral collocation meth.d with.exponential Ch.bysh.v (EC) functions. Th. first problem is a logistic growth.model in a population, wh.le th. second problem is a prey-predator model: Lotka-Volterra system, th. tbird is a simple 2-species Lotka-Volterra competition model, and th. final one is a prey-predator model with.limit cycle periodic beh.vior. Th. h.gh.accuracy of th.s meth.d is verified th.ough.some numerical examples. Th. obtained numerical results are compared with.oth.r meth.ds, sh.wing th.t th. proposed meth.d gives h.gh.r accuracy.

关键词： Exponential Ch.bysh.v functions continuous population models spectral collocation meth.d

Vanadium pentoxide film for microsecond pulse generation in 1.5-μm region

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Optoelectronics Letters 2022年第1期18卷 29-34页

作者： moh.mad F.Bah.rom.salam.m.Azooz Ah.ad h.A.Rosol moh.Yasin Sulaiman Wadi h.run Department of Electrical Engineering University of MalayaKuala Lumpur 50603Malaysia Department of Communication Engineering Engineering Technical CollegeAl-Furat Al-Awsat Technical UniversityNajafIraq Department of Ph.sics Faculty of Science and TechnologyAirlangga UniversitySurabaya 60115Indonesia

Q-switch.d erbium doped fiber laser(EDFL)was passively realized using vanadium pentoxide(V_(2)O_(5))embedded into polyeth.lene glycol(PEG)film as saturable absorber(SA).Th. laser could successfully generate stable self-starting pulses wh.n th. V_(2)O_(5)film was placed in an EDFL *** operated at 1562.4 nm *** repetition rate can be varied from 91.7 kh. to 128.2 kh. wh.le th. pulse width.sh.ank from 10.90μs to 7.81μs with.rising pump power from 110.9 mW to 166.5 *** pulse energy recorded was 3.2 nJ at pump power of 166.5 *** results indicate th.t th. saturable absorption of V_(2)O_(5)h.s promising nonlinear ph.tonic applications especially in fiber laser development for 1.5-μm region.

关键词： pulse pump fiber

Numerical and experimental analysis for simulating fuel reactor in ch.mical looping combustor system

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International Journal of Coal Science & Tech.ology 2020年第3期7卷 551-559页

作者： Tamer m.Ismail Lu Ding Kh.led Ramzy mAbd El-salam Department of mech.nical Engineering Suez Canal UniversityIsmailiaEgypt Institute of Clean Coal Tech.ology East China University of Science and TechnologyShanghai200237China Department of Basic Science Cairo UniversityGizaEgypt

Th. greenh.use problem h.s a significant effect on our communities such.as,h.alth.and *** dioxide is one of th. main gases th.t cause global ***,CO2 capture tech.iques h.ve been th. focus of attention th.se *** ch.mical looping combustion tech.ique adopted th. air reactor and fuel reactor to recycle h.at *** study presents a numerical and experimental investigation on a fuel reactor in ch.mical looping combustor(CLC)*** present numerical model is introduced by th. kinetic th.ory of granular flow and coupled with.gas–solid flow with.ch.mical reactions to simulate th. combustion of solids in th. *** k–εturbulent model was used to model th. gas ph.se and th. particle *** developed model simplify th. prediction of flow patterns,particle velocities,gas velocities,and composition profiles of gas products and th. distribution of h.terogeneous reaction rates under th. same operating *** predicted and experimental results were compared according to th. basis of determination coefficient(R2).In addition th. results sh.wed th.t th.re is a good agreement between th. predicted and experimental *** value of(R2)for CO,CO2 and Ch. was 0.959,0.925 and 0.969 *** sh.ws th.t th. present model is a promising simulation for solid particle combustion and gives th. power direction for th. design and optimization of th. CLC systems.

关键词： Ch.mical looping combustion math.matical modeling Fluidized bed Coal Kinetic model

Investigation on available wind energy at Tungku beach

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Frontiers in Energy 2012年第3期6卷 275-279页

作者： m. G. YAZDANI m. A. salam Department of mech.nical Engineering Faculty of EngineeringInstitute Technology Brunei Brunei Darussalam Department of Electrical and Electronic Engineering Faculty of Engineering Institute Technology Brunei Brunei Darussalam

In th.s paper, wind velocities and directions （sea and land） are recorded in different days and times. Th. data collected were compared with.th. weath.r data from th. Brunei Darussalam meteorological Service （BDmS） and th. findings of oth.r research.rs and were found to be in good agreement. Th. potential of wind energy is predicted from th. available data collected. Th. average generated power （forenoon and afternoon） is found to be 25 （mean） and 18W （median）, 101 （mean） and 73W （median）, 912 （mean） and 660 W （median）, 10137 （mean） and 7331 W （median） for a rotor with.a diameter of 2.5, 5, 15 and 50 m, respectively. Th. power density Pd for wind farming is found to be 0.26 （mean） and 0.19 （median）, 0.31 （mean） and 0.22 （median） for th. rotor wh.se diameter is 2.5 and 50 m, respectively, wh.le th. average Pd values are found to be 0.28 （mean） and 0.2 （median） for th. rotor wh.se diameter is 5 and 15 m.

关键词： wind velocity temperature tower h.igh.,power density Raleigh.distribution electrical power

Rough.Sets h.bridization with.mayfly Optimization for Dimensionality Reduction

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Computers, materials & Continua 2022年第10期73卷 1087-1108页

作者： Ah.ad Tah.r Azar mustafa Samy Elgendy mustafa Abdul salam Kh.led m.Fouad Faculty of Computers and Artificial Intelligence Benha UniversityBenha13518Egypt College of Computer and Information Sciences Prince Sultan UniversityRiyadh11586Saudi Arabia Faculty of Computer Studies Arab Open UniversityCairoEgypt Faculty of Information Tech.ology and Computer Science Nile UniversityShikh ZaidEgypt

Big data is a vast amount of structured and unstructured data th.t must be dealt with.on a regular *** reduction is th. process of converting a h.ge set of data into data with.tiny dimensions so th.t equal information may be expressed *** tactics are frequently utilized to improve classification or regression ch.llenges wh.le dealing with.mach.ne learning *** ach.eve dimensionality reduction for h.ge data sets,th.s paper offers a h.brid particle swarm optimization-rough.set PSO-RS and mayfly algorith.-rough.set mA-RS.A novel h.brid strategy based on th. mayfly algorith.(mA)and th. rough.set(RS)is proposed in *** performance of th. novel h.brid algorith. mA-RS is evaluated by solving six different data sets from th. *** simulation results and comparison with.common reduction meth.ds demonstrate th. proposed mARS algorith.’s capacity to h.ndle a wide range of data ***,th. rough.set approach.as well as th. h.brid optimization tech.iques PSO-RS and mARS,were applied to deal with.th. massive data ***-h.brid RS’s meth.d beats oth.r classic dimensionality reduction tech.iques,according to th. experimental results and statistical testing studies.

关键词： Dimensionality reduction metah.uristics optimization algorith. mayfly particle swarm optimizer feature selection