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h-m Bearing Capacity of A modified Suction Caisson Determined by Using Load-/Displacement-Controlled methods

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China Ocean Engineering 2016年第6期30卷 926-941页

作者：张雨坤高玉峰李大勇 ali h.mahfouz Key Laboratory of ministry of Education for Geomechanies and Embankment Engineering Hohai UniversityNanjing 210098China College of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China Faculty of Petroleum and mining Engineering Suez UniversityIsmailiaEgypt

This paper presents a series of monotonically combined lateral loading tests to investigate the bearing capacity of the mSCs （modified suction caissons） in the saturated marine fine sand. The lateral loads were applied under load- and displacement-controlled methods at the loading eccentricity ratios of 1.5, 2.0 and 2.5. Results show that, in the displacement-controlled test, the deflection-softening behavior of load-deflection curves for mSCs was observed, and the softening degree of the load-deflection response increased with the increasing external skirt length or the decreasing loading eccentricity. It was also found that the rotation center of the mSC at failure determined by the load-controlled method is slightly lower than that by the displacement-controlled method. The calculated mSC capacity based on the rotation center position in serviceability limit state is relatively conservative, compared with the calculated capacity based on the rotation center position in the ultimate limit state. In the limit state, the passive earth pressures opposite the loading direction under load- and displacement-controlled methods decrease by 46% and 74% corresponding to peak values, respectively; however, the passive earth pressures in the loading direction at failure only decrease by approximately 3% and 7%, compared with their peak values.

关键词： mSC (modified suction caisson) saturated marine fine sand model tests load- and displacement-controlled loading laterally combined bearing capacity earth pressure

The electrical impedance, AC conductivity and dielectric properties of phenol red compound investigated and modeled by an artificial neural network

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Communications in Theoretical Physics 2020年第10期72卷 139-148页

作者： h.a.m.ali D m habashy Physics Department Faculty of EducationAin Shams UniversityRoxyCairo 11757Egypt

The impedance spectroscopy,electrical conductivity and electric modulus of bulk phenol red were measured,as a function of both frequency and *** neural networks(ANNs)were used for modeling its electrical *** two parts(real and imaginary)of its complex impedance(Z^*)were analyzed and the activation energy related to the electrical relaxation process was *** curves were plotted showing semicircles for the different *** AC electrical conductivity follows a power lawσac(ω)αω^η.The maximum barrier height Bm was derived for specific temperatures.A plausible mechanism for the AC conduction of bulk phenol red was deduced from the temperature reliance of the frequency *** dielectric data was analyzed using electric modulus as a *** addition,ANNs were used to model the impedance parts and the total electrical *** runs were tried,to obtain the best *** training and prediction results were compared to the equivalent experimental results,with a good match *** equation describing the experimental results was obtained mathematically,based on the use of *** outputs demonstrated that ANNs are an admirable tool for modeling experimental results.

关键词： phenol red impedance spectroscopy electric modulus neural network

Casimir wormholes inspired by electric charge in Einstein–Gauss–Bonnet gravity

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Communications in Theoretical Physics 2024年第12期76卷 95-114页

作者： mushayydha Farooq m Zubair ali h Alkhaldi Akram ali Department of mathematics COMSATS University IslamabadLahore Campus National Astronomical Observatories Chinese Academy of Sciences Department of mathematics King Khalid University

This investigation assesses the feasibility of a traversable wormhole by examining the energy densities associated with charged Casimir phenomena. We focus on the influence of the electromagnetic field created by an electric charge as well as the negative energy density arising from the Casimir source. We have developed different shape functions by defining energy densities from this combination. This paper explores various configurations of Casimir energy densities, specifically those occurring between parallel plates, cylinders and spheres positioned at specified distances from each other. Furthermore, the impact of the generalized uncertainty principle correction is also examined. The behavior of wormhole conditions is evaluated based on the Gauss–Bonnet coupled parameter(μ) and electric charge(Q) through the electromagnetic energy density constraint. This is attributed to the fact that the electromagnetic field satisfies the characteristic ρ =-pr. Subsequently, we examine the active gravitational mass of the generated wormhole geometries and explore the behavior of μ and Q concerning active mass. The embedding representations for all formulated shape functions are examined. Investigations of the complexity factor of the charged Casimir wormhole have demonstrated that the values of the complexity factor consistently fall within a particular range in all scenarios. Finally, using the generalized Tolman–Oppenheimer–Volkoff equation, we examine the stability of the resulting charged Casimir wormhole solutions.

关键词： charged casimir wormholes GUP-Corrected casimir wormholes modified gravity

New ternary superconducting compound LaRu2As2： Physical properties from density functional theory calculations

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Chinese Physics B 2017年第3期26卷 453-460页

作者： m A hadi m S ali S h Naqib A K m A Islam Department of Physics University of Rajshahi Rajshahi 6205 Bangladesh Department of Physics Pabna University of Science and Technology Pabna 6600 Bangladesh International Islamic University Chittagong Chittagong 4203 Bangladesh

In this paper, we perform the density functional theory （DFT） -based calculations by the first-principles pseudopo- tential method to investigate the physical properties of the newly discovered superconductor LaRu2As2 for the first time. The optimized structural parameters are in good agreement with the experimental results. The calculated independent elas- tic constants ensure the mechanical stability of the compound. The calculated Cauchy pressure, Pugh＇s ratio as well as Poisson＇s ratio indicate that LaRu2As2 should behave as a ductile material. Due to low Debye temperature, LaRu2As2 may be used as a thermal barrier coating （TBC） material. The new compound should exhibit metallic nature as its valence bands overlap considerably with the conduction bands. LaRu2As2 is expected to be a soft material and easily machinable because of its low hardness value of 6.8 GPa. The multi-band nature is observed in the calculated Fermi surface. A highly anisotropic combination of ionic, covalent and metallic interactions is expected to be in accordance with charge density calculation.

关键词： new superconductor LaRu2As2 density functional theory (DFT) calculations mechanical proper-ties electronic features

Study of abundant explicit wave solutions of the Drinfeld-Sokolov-Satsuma-hirota(DSSh)equation and the shallow water wave equation

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Propulsion and Power Research 2018年第4期7卷 320-328页

作者： h.m.Shahadat ali m.mamun miah m.ali Akbar Department of Applied mathematics Noakhali Science and Technology UniversityNoakhali 3814Bangladesh Department of mathematics Khulna University of Engineering&Technology.Khulna 9203Bangladesh Department of Applied mathematics University of Rajshahi.Rajshahi 6205Bangladesh

In this article,the two variable(G'G,1/G)-expansion method is suggested to investigate new and further general multiple exact wave solutions to the Drinfeld-Sokolov-Satsuma-hirota(DSSh)equation and the shallow water wave equation which arise in mathematical physics with the aid of computer algebra software,like *** functions and the rational functions solution are *** method demonstrates power,reliability and ***,the method is the generalization of the well-known(G/G)-expansion method established by Wang et *** the method also presents a wider applicability for conducting nonlinear wave equations.

关键词： Explicit wave solutions Computer algebra software Drinfeld-Sokolov-Satsuma-hirota(DSSh)equation Shallow water wave equation Soliton

An ab initio investigation of vibrational, thermodynamic, and optical properties of Sc_2AlC mAX compound

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Chinese Physics B 2016年第10期25卷 103-108页

作者： m A ali m T Nasir m R Khatun A K m A Islam S h Naqib Department of Physics Chittagong University of Engineering and Technology Department of Arts & Sciences Bangladesh Army University of Science and Technology Department of Physics University of Rajshahi International Islamic University Chittagong

The structural vibrational, thermodynamical, and optical properties of potentially technologically important, weakly coupled mAX compound, Sc2 Al C are calculated using density functional theory(DFT). The structural properties of ScAlC are compared with the results reported earlier. The vibrational, thermodynamical, and optical properties are theoretically estimated for the first time. The phonon dispersion curve is calculated and the dynamical stability of this compound is investigated. The optical and acoustic modes are observed clearly. We calculate the helmholtz free energy(F), internal energy(E), entropy(S), and specific heat capacity(Cv) from the phonon density of states. Various optical parameters are also calculated. The reflectance spectrum shows that this compound has the potential to be used as an efficient solar reflector.

关键词： mAX compound phonon dispersion thermodynamical properties optical properties

Effects of g-jitter and radiation on three-dimensional double diffusion stagnation point nanofluid flow

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Applied mathematics and mechanics(English Edition) 2020年第11期41卷 1707-1722页

作者： m.h.A.KAmAL N.A.RAWI A.ali S.ShAFIE Department of mathematical Sciences Faculty of ScienceUniversiti Teknologi MalaysiaJohor Bahru 81310Johor Darul TakzimMalaysia

The unsteady double diffusion of the boundary layer with the nanofluid flow near a three-dimensional(3D)stagnation point body is studied under a microgravity *** effects of g-jitter and thermal radiation exist under the microgravity environment,where there is a gravitational field with *** flow problem is mathematically formulated into a system of equations derived from the physical laws and principles under the no-slip boundary *** the semi-similar transformation technique,the dimensional system of equations is reduced into a dimensionless system of equations,where the dependent variables of the problem are lessened.A numerical solution for the flow problem derived from the system of dimensionless partial differential equations is obtained with the Keller box method,which is an implicit finite difference *** effects studied are analyzed in terms of the physical quantities of principle interest with the fluid behavior characteristics,the heat transfer properties,and the concentration *** results show that the value of the curvature ratio parameter represents the geometrical shape of the boundary body,where the stagnation point is *** increased modulation amplitude parameter produces a fluctuating behavior on all physical quantities studied,where the fluctuating range becomes smaller when the oscillation frequency ***,the addition of Cu nanoparticles enhances the thermal conductivity of the heat flux,and the thermal radiation could increase the heat transfer properties.

关键词： stagnation point nanofluid thermal radiation g-jitter double diffusion

Novel synthesis of stabilized Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5) solid electrolytes with enhanced conductivity for intermediate temperature solid oxide fuel cells(SOFCs)

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Journal of Rare Earths 2024年第10期42卷 1903-1911页

作者： Ahmed h.Ibrahim Yehia m.Abbas h.A.Ayoub marwa h.ali mustafa Aldoori materials Science Laboratory Physics DepartmentFaculty of ScienceSuez Canal University41522IsmailiaEgypt ministry of higher Education and Scientific Research Aliraqia University10011BaghdadIraq

herein,we report the synthesis of a Dy-Gd co-doped cubic phase-stabilized Bi_(2)O_(3) solid electrolyte system via solid-state processing under atmospheric *** with Dy^(3+) and Gd^(3+) has been observed to significantly enhance the densification process during sintering for stabilization purposes,thereby improving the electrical properties of δ-Bi_(2)O_(3)-type *** synthesized ceramics were characterized using X-ray diffraction(XRD),field emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEm-EDX),thermal gravimetry/differential thermal analysis(TG/DTA),and the four-point probe technique(4PPT).XRD analysis reveals that the samples Bi_(1-x-y)Gd_(x)Dy_(y)O_(1.5)(y=0.05/x=0.05,0.10,0,15,and 0.20,and x=0.05/y=0.10,0.15,and 0.20) exhibit a stable face-centered cubic δ-phase and a mixed-phase crystallographic *** XRD analysis of the stabilized δ-phase suggests that the prepared oxides show a face-centered cubic(FCC) structure with a space group of *** micrographs reveal that the composition Bi_(0.90)Gd_(0.05)Dy_(0.05)O_(1.5) has no significant ***,an evident increase in the pore formation is observed as the amount of Gd_(2)O_(3) increases until it reaches 20%.This finding suggests that dense pellets are formed during the sintering process at 900-1000℃.The DTA analyses were performed to verify the phase stability,which agrees with the XRD *** electrochemical performance of the synthesized Dy-Gd co-doped Bi_(2)O_(3)solid electrolyte system was evaluated and analyzed in detail by using the electrochemical impedance spectroscopy(EIS) technique,Based on EIS and conductivity measurements,Bi_(0.75)Gd_(0.20)Dy_(0.05)O_(1.5) exhibits the lowest activation energy of 0.519 eV and the highest conductivity value of 0.398 S/cm at 627℃compared to the other samples;this composition can be used as a solid electrolyte for intermediatetemperature solid oxide fuel cells(SOFCs).

关键词： Solid oxide fuel cells(SOFCs) Rare earths Solid-state processing Rietveld Fast Fourier transform(FFT) Electrochemical impedance spectroscopy(EIS)

Numerical Algorithm for Solving multi-Pantograph Delay Equations on the half-line Using Jacobi Rational Functions with Convergence Analysis

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Acta mathematicae Applicatae Sinica 2017年第2期33卷 297-310页

作者： Eid h. DOhA ali h. BhRAWY Ramy m. hAFEZ Department of mathematics Faculty of Science Cairo University Giza Egypt Department of mathematics Faculty of Science King Abdulaziz University Jeddah Saudi Arabia Department of mathematics Faculty of Science Beni-Suef University Beni-Suef Egypt Department of mathematics Alwagjh University College University of Tabuk Tabuk Saudi Arabia Department of Basic Science Institute of Information Technology Modern Academy Cairo Egypt

A new spectral Jacobi rational-Gauss collocation （JRC） method is proposed for solving the multi- pantograph delay differential equations on the half-line. The method is based on Jacobi rational functions and Gauss quadrature integration formula. The main idea for obtaining a semi-analytical solution for these equations is essentially developed by reducing the pantograph equations with their initial conditions to systems of algebraic equations in the unknown expansion coefficients. The convergence analysis of the method is analyzed. The method possesses the spectral accuracy. Numerical results indicating the high accuracy and effectiveness of this algorithm are presented. Indeed, the present method is compared favorably with other methods.

关键词： multi-pantograph equation delay equation collocation method Jacobi-Gauss quadrature Jacobirational functions convergence analysis