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Journal of Hydrodynamics 2015年第3期27卷 436-442页

作者： AmEUR Houari BOUZIT mohamed GHENAIm abdellah Laboratoire de mécanique Appliquée Faculté de Génie MécaniqueUSTO-MB Institut de Technologie Université Ibn Khaldoun INSA de Strasbourg-24 Bd de la Victoire-67084 Strasbourg-France

The 3-D flow fields and power consumption in a vessel stirred by multistage Scaba 6SRGT impeller have been investiga- ted. The Xanthan gum solutions in water were used, which have a shear thinning behavior with yield stress. This study was carried out with the help of a CFD package （CFX 13.0, Ansys Inc.） which is based on the finite volume method to solve the momentum equations. The effects of stirring rate, fluid rheology, impeller number, impeller location and vessel size on the performance of such stirred system are presented. To validate the CFD model, our predicted results have been compared with other literature data and a satisfactory agreement has been found.

关键词： Scaba 6SRGT impeller multistage agitator yield stress fluid stirred tank power consumption

An Adjustable Variant of Round Robin Algorithm Based on Clustering Technique

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Computers, materials & Continua 2021年第3期66卷 3253-3270页

作者： Samih m.mostafa Hirofumi Amano Faculty of Computers and Information South Valley UniversityQena83523Egypt Research Institute for Information Technology Kyushu UniversityFukuoka819-0395Japan

CPU scheduling is the basic task within any time-shared operating *** of the main goals of the researchers interested in CPU scheduling is minimizing time *** between CPU scheduling algorithms is subject to some scheduling criteria(e.g.,turnaround time,waiting time and number of context switches(NCS)).Scheduling policy is divided into preemptive and *** Robin(RR)algorithm is the most common preemptive scheduling algorithm used in the time-shared operating *** this paper,the authors proposed a modified version of the RR algorithm,called dynamic time slice(DTS),to combine the advantageous of the low scheduling overhead of the RR and favor short process for the sake of minimizing time *** process has a weight proportional to the weights of all *** process’s weight determines its time slice within the current *** authors benefit from the clustering technique in grouping the processes that are similar in their attributes(e.g.,CPU service time,weight,allowed time slice(ATS),proportional burst time(PBT)and NCS).Each process in a cluster is assigned the average of the processes’time slices in this cluster.A comparative study of six popular scheduling algorithms and the proposed approach on nine groups of processes vary in their attributes was performed and the evaluation was measured in terms of waiting and turnaround times,and *** experiments showed that the proposed algorithm gives better results.

关键词： Clustering CPU scheduling round robin turnaround time waiting time

Some Applications of Differential Subordination of p-Valent Functions Associated with Cho-Kwon-Srivastava Operator

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Acta mathematica Sinica,English Series 2009年第9期25卷 1483-1496页

作者： A.O.mostafa m.K.AOUF Department of mathematics Faculty of Science Mansoura University

making use of the principle of differential subordination, we investigate some inclusion relationships of certain subclasses of p-valent analytic functions which are defined by Cho-Kwon Srivast ava Operator.

关键词： differential subordination p-valent functions Cho-Kwon-Srivastava operator

Novel aspects for thermal stability studies and shelf life assessment of modified double-base propellants

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Defence Technology（防务技术） 2019年第3期15卷 300-305页

作者： Sherif Elbasuney Ashraf.m. A. Elghafour mostafa Radwan Ahmed Fahd Hosam mostafa Ramy Sadek Amr motaz School of Chemical Engineering Military Technical College Kobry El-Kobba Cairo Egypt British University in Egypt Elshrouk city Cairo Egypt

modified DB propellants, based on energetic nitramine(RDX) were manufactured by solventless extrusion process. Thermal stability and shelf life assessment of modified DB propellant were investigated. Shelf life assessment was evaluated using Van’t Hoff’s formula and artificial aging at 70℃ up to120 days. Quantification of total heat released and heat flow with aging time was conducted using differential scanning calorimetry(DSC) and thermal activity monitoring(TAmIII) respectively. modified DB formulation based on 20 wt % RDX demonstrated enhanced thermal stability in terms of controlled heat flow, and slow decomposition reactions at elevated temperature. This formulation demonstrated extended service life up to 56 years compared with reference formulation. These novel finding was ascribed to the high thermal stability of RDX and its compatibility with DB constituents. This manuscript shaded the light on novel and effective approach for thermal stability via monitoring thermal activity with aging.

关键词： Double-base propellant Thermal stability Artificial aging Shelf-life assessment

Experimental and mathematical modeling of Cr(Ⅵ) removal using nano-magnetic Fe3O4-coated perlite from the liquid phase

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1582-1590页

作者： Ismail m.Ahmed mostafa m.Hamed Sayed S.metwally Chemistry Department College of ScienceJouf UniversitySkakaSaudi Arabia Hot Laboratories and Waste management Center Atomic Energy Authority13759 CairoEgypt

modification of perlite using nano-magnetic iron oxide was implemented to produce nano-magneticFe3O4-coated perlite composite(Fe3O4/Perlite).The prepared composite was characterized using Scanning Electron microscopy,Fourier-Transform Infrared spectroscopy and Powder X-ray *** potentiality of both perlite and Fe3O4/Perlite composite to eliminate Cr(VI)from the environmentally relevant water was *** influence of main factors which could affect the adsorption was studied including;pH of medium,shaking time and Cr(VI)ions *** experimental outcome demonstrated that the modification of perlite by nano-magnetic Fe3O4 showed a significantly enhanced Cr(VI)removal efficiency relative to that of unmodified *** the kinetic studies,the experimental data fitted well with the pseudo-second-order ***,it proposes that Langmuir isotherm is more adequate than the Freundlich isotherm for both perlite and modified *** results recommended that Fe3O4/Perlite composite had a great potential as an economic and efficient adsorbent of Cr(VI)from contaminated water,which has huge application potential.

关键词： Nano-magnetic Composite Kinetics Isotherm Perlite Adsorption

Simple and sensitive method for the determination of trace amounts of thorium using a benzoquinone derivative

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Nuclear Science and Techniques 2019年第5期30卷 22-31页

作者： mostafa m.Hamed Refaat F.Aglan Hot Laboratories and Waste management Center Atomic Energy Authority of Egypt

A novel simple, sensitive, rapid, direct, and spectrophotometry-based procedure was investigated to determine Th(IV) at trace amounts. The new method is based on Th(IV) chelation with 3,6-dichloro-2,5-dihydroxy-l,4-benzoquinone(DDBQ). The reagent reacts with Th(IV) in 0.1 m HCl to form an orange 1:2 complex. The stability constant value is 6.62×10~4 for the Th(IV)complex. The Th(IV)-DDBQ obtained shows one peak with a maximum at about 346 nm. The chelate forms immediately and the absorbance remains stable for over24 h. Beer's law was obeyed in the concentration range0–10 μg mL^(-1). The molar absorptivity and Sandell's sensitivity were 4.4×10~4 L mol^(-1)cm^(-1) and 0.0053 μg cm^(-2), respectively. Different analytical parameters were tested in detail. Interfering ion(cations and anions) effects were tested. methods for Th(IV) determination by second and third-derivative spectrophotometry were also introduced at about 344 and 341 nm, respectively. These two derivative orders offer the feature of sensitivity without the necessity for solvent extraction,heating, or pre-concentration steps. Finally, the methods were successfully utilized for Th(IV) determination in monazite, environmental water, and wastewater samples.

关键词： Th(IV) determination p-benzoquinone derivative Spectrophotometry

Plenty of analytical and semi-analytical wave solutions of shallow water beneath gravity

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Journal of Ocean Engineering and Science 2022年第3期7卷 237-243页

作者： mostafa m.A.Khater SamirA.Salama Department of mathematics Faculty of ScienceJiangsu UniversityZhenjiang 212013China Department of mathematics Obour High Institute For Engineering and TechnologyCairo 11828Egypt Division of Biochemistry Department of PharmacologyCollege of PharmacyTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

This article studies novel soliton wave solutions of the nonlinear fractional ill-posed Boussinesq(NLFIPB)dynamic wave equation by applying the extended Riccati-expansion(ERE)*** Hadamard has formulated the investigated model to figure out the dynamic characterizations of waves in shallow water under *** obtained solutions are explained through some sketches in 2D and 3D and contour *** the same time,the results’accuracy is checked by comparing the obtained solutions with semianalytical solutions through the well-known Adomian decomposition(AD)*** superiority of the ERE method over the original method is *** constructed solutions are checked by submitting them back into the original model through mathematica 12 software.

关键词： Ill-posed Boussinesq dynamical wave Analytical and semi-analytical simulations

New exact solutions for the time fractional coupled Boussinesq-Burger equation and approximate long water wave equation in shallow water

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Journal of Ocean Engineering and Science 2017年第3期2卷 223-228页

作者： mostafa m.A.Khater Dipankar Kumar Department of mathematics Faculty of ScienceJiangsu UniversityJiangsuChina Faculty of Science Department of MathematicsMansoura University35516 MansouraEgypt Doctoral Student Division of Engineering Mechanics and EnergyGraduate School of Systems and Information EngineeringUniversity of TsukubaTennodai 1-1-1TsukubaIbarakiJapan Department of mathematics Bangabandhu Sheikh Mujibur Rahman Scienceand Technology UniversityGopalganj 8100Bangladesh

The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov *** fractional differential equation is converted into ordinary differential equations with the help of fractional complex transform and the modified Riemann-Liouville derivative *** the generalized Kudryashov method through with symbolic computer maple package,numerous new exact solutions are successfully *** calculations in this study have been established and verified back with the aid of the maple package *** executed method is powerful,effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions with the integer and fractional order.

关键词： The generalized Kudryashov method The time fractional coupled Boussinesq-Burger equation The time fractional approximate long water wave equation Exact solutions

Semi-analytical and numerical simulations of the modified Benjamin-Bona-mahony model

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Journal of Ocean Engineering and Science 2022年第3期7卷 264-271页

作者： mostafa m.A.Khater SamirA.Salama Department of mathematics Faculty of ScienceJiangsu UniversityZhenjiang212013China Department of mathematics Obour High Institute For Engineering and TechnologyCairo11828Egypt Division of Biochemistry Department of PharmacologyCollege of PharmacyTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

In this article,semi-analytical and numerical simulations of the well-known modified Benjamin-Bona-mahony(mBBm)equation are *** study targets to check the accuracy of the obtained analytical solutions of the mBBm model that have been obtained in[1]through three recent analytical schemes(extended simplest equation(ESE)method,modified kudryashov(mKud)method,and SechTanh(ST)expansion method).The considered model describes the propagation of long waves in the nonlinear dispersive media in a visual *** Homotopy iteration(HI)method,exponential cubic-B-spline(ECBS)method,and trigonometric-quantic-B-spline(TQBS)method are employed to construct novel semi-analytical and accurate numerical *** obtained solutions’accuracy has been checked through some different types of two-dimensional graphs.

关键词： modified Benjamin-Bona-mahony equation Approximate solutions

Kinematic Analysis and Design of a 3-DOF Translational Parallel Robot

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International Journal of Automation and computing 2017年第4期14卷 432-441页

作者： mahmood mazare mostafa Taghizadeh m. Rasool Najafi School of mechanical Engineering Shahid Beheshti University Tehran lran Department of Engineering University of Qom Qom Iran

Parallel mechanisms are widely used in various fields of engineering and industrial applications such as machine tools, flight simulators, earthquake simulators, medical equipment, etc. Parallel mechanisms are restricted to some limitations such as irregular workspace, existence of singular points and complexity of control systems which should be studied and analyzed for effective and efficient use. In this research, a new machine tool with parallel mechanism which has three translational degrees of freedom is studied and the workspace and singular points are determined by deriving analytical equations and then utilizing of matlab software. To do so, forward and inverse kinematics of the mechanism are obtained and workspace and singular points are calculated using a search algorithm. Afterward in order to validate the results, the proposed mechanism is simulated in automatic dynamics analysis of mechanical systems （ADAmS） software. moreover, in order to investigate the quality of robot performance and dexterity of the mechanism in its workspace, global dexterity index （GDI） of the robot is calculated using Jacobean matrix at different positions of the mobile platform.

关键词： Kinematic analysis parallel robot workspace manipulability dexterity.