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Bifurcation and Stability Analysis of the Hamiltonian-Casimir Model of Liquid Sloshing

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Chinese Physics Letters 2012年第6期29卷 46-49页

作者： salman ahmad YUE Bao-Zeng Department of Humanities&Sciences Institute of Space TechnologyIslamabad 44000Pakistan Department of Mechanics School of Aerospace EngineeringBeijing Institute of TechnologyBeijing 100081

Motion stability of a spacecraft is discussed.A canonical Hamiltonian model for liquid sloshing is presented for a moving rigid *** equivalent mechanical pendulum model is used to represent the fuel slosh inside the *** this model sloshing is represented by the moving mass,the rest of the mass of the spacecraft is assumed to be *** spacecraft structure is considered to be an elliptical rigid shape and the steady rotation along the x-axis is taken as the major-axis *** stability for the present model is analyzed using the Lyapunov theory with Casimir energy *** for stability and instability are derived for a steady principal axis rotation of the rigid *** results are presented to distribute the region into stable and unstable *** this,the nonlinear behavior of the system is analyzed under the influence of an external force acting *** is observed through a bifurcation *** time history map and phase portrait are also presented to analyze the nonlinear behavior of the system.

关键词： Hamiltonian rotation stability

A Class of Maximal Functions with Oscillating Kernels

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Acta Mathematica Sinica,English Series 2007年第11期23卷 2003-2016页

作者： ahmad AL-salman Department of Mathematics Yarmouk UniversityIrbidJordan

The author studies the L^p mapping properties of a class of maximal functions that are related to oscillatory singular integral operators. Lp estimates, as well as the corresponding weighted estimates of such maximal ... 详细信息

关键词： oscillatory singular integrals maximal functions weighted L^p bounds power weights,parametric Marcinkiewicz integral operators Morrey spaces

Parabolic Marcinkiewicz Integrals along Surfaces on Product Domains

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Acta Mathematica Sinica,English Series 2011年第1期27卷 1-18页

作者： ahmad AL-salman Department of Mathematics and Statistics Sultan Qaboos University P.O. Box 36 A1-Khod 123 Muscat Sultanate of Oman

Abstract In this paper, parabolic Marcinkiewicz integral operators along surfaces on the product domain Rn ×RM （n, m ≥2） are introduced. Lp bounds of such operators are obtained under weak conditions on the kernels.

关键词： Parabolic Marcinkiewicz integral operators parabolic maximal functions Fourier transform rough kernels

Impact of slip boundary on sloshing motions in partially filled containers

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Chinese Science Bulletin 2011年第25期56卷 2674-2678页

作者： ahmad salman Department of Mechanics School of Aerospace Engineering Beijing Institute of Technology

Sloshing is a kind of fluid motion inside partially filled containers. In spacecraft and other partially filled moving containers, sloshing plays an important role. The contact line between the fluid and solid boundary affects the fluid movement and sloshing during motion. A physical model for steady fluid flow with a partial slip boundary is presented and equations for this model are derived for cylindrical (tube-shaped) tanks. This gives a nonlinear system of differential equations that is solved numerically by using a Successive Over-Relaxation (SOR) technique and graphical results are shown. Variations in steady fluid flow are observed with changes in the slip length and some useful results are derived. The effects on the microscopic radius of the fluid layer in a capillary tube are also shown through graphical results.

关键词：部分填充晃动滑移容器流体运动物理模型流体流动图形显示

L^p Estimates of certain rough parametric Marcinkiewicz functions

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Frontiers of Mathematics in China 2019年第5期14卷 867-879页

作者： Laith HAWAWSHEH ahmad AL-salman School of Basic Sciences and Humanities German Jordanian UniversityAmmanJordan Department of Mathematics Sultan Qaboos UniversityP.O.Box 36Al-Khod 123 MuscatOman

We prove L^P estimates of a class of parametric Marcinkiewicz integral operators when their kernels satisfy only the L^1(S^n-1)integrability *** obtained L^P estimates resolve a problem left open in previous *** argument is based on duality technique and direct estimation of *** a consequence of our result,we deduce the L^P boundedness of a class of fractional Marcinkiewicz integral operators.

关键词： Marcinkiewicz integrals parametric Marcinkiewicz functions rough kernels Marcinkiewicz interpolation theorem

L^p Estimates of Rough Maximal Functions Along Surfaces with Applications

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Acta Mathematica Sinica,English Series 2016年第8期32卷 925-942页

作者： ahmad AL-salman Abdulla M.JARRAH Department of Mathematics Yarmouk University

Abstract In this paper, we study the Lp mapping properties of certain class of maximal oscillatory singular integral operators. We prove a general theorem for a class of maximal functions along surfaces. As a consequence of such theorem, we establish the Lp boundedness of various maximal oscillatory singular integrals provided that their kernels belong to the natural space L log L（Sn-1）. Moreover, we highlight some additional results concerning operators with kernels in certain block spaces. The results in this paper substantially improve previously known results.

关键词： Oscillatory singular integrals rough kernels maximal functions highly monotone curves

Tracing overlapping biological signals in mid-infrared using colonic tissues as a model system

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World Journal of Gastroenterology 2017年第2期23卷 286-296页

作者： Ranjit Kumar Sahu ahmad salman Shaul Mordechai Department of Physics Ben Gurion University Department of Medicine University of Virginia Department of Physics SCE-Shamoon College of Engineering

AIMTo understand the interference of carbohydrates absorbance in nucleic acids signals during diagnosis of malignancy using Fourier transform infrared (FTIR) *** used formalin fixed paraffin embedded colonic tissues to obtain infrared (IR) spectra in the mid IR region using a bruker II IR microscope with a facility for varying the measurement area by varying the aperture available. Following this procedure we could measure different regions of the crypt circles containing different biochemicals. Crypts from 18 patients were measured. Circular crypts with a maximum diameter of 120 μm and a lumen of about 30 μm were selected for uniformity. The spectral data was analyzed using conventional and advanced computational *** the various components that are observed to contribute to the diagnostic capabilities of FTIR, the carbohydrates and nucleic acids are prominent. However there are intrinsic difficulties in the diagnostic capabilities due to the overlap of major absorbance bands of nucleic acids, carbohydrates and phospholipids in the mid-IR region. The result demonstrates colonic tissues as a biological system suitable for studying interference of carbohydrates and nucleic acids under ex vivo conditions. Among the diagnostic parameters that are affected by the absorbance from nucleic acids is the RNA/DNA ratio, dependent on absorbance at 1121 cm-1 and 1020 cm-1 that is used to classify the normal and cancerous tissues especially during FTIR based diagnosis of colonic malignancies. The signals of the nucleic acids and the ratio (RNA/DNA) are likely increased due to disappearance of interfering components like carbohydrates and phosphates along with an increase in amount of *** present work, proposes one mechanism for the observed changes in the nucleic acid absorbance in mid-IR during disease progression (carcinogenesis).

关键词： Spectral interference Fourier transform infrared diagnosis Nucleic acids Malignancy Colonic tissue

Modeling Chemically Reactive Flow of Sutterby Nanofluid by a Rotating Disk in Presence of Heat Generation/Absorption

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Communications in Theoretical Physics 2018年第5期69卷 569-576页

作者： T.Hayat salman ahmad M.Ijaz Khan A.Alsaedi Department of Mathematics Quaid-I-Azam University Nonlinear Analysis and Applied Mathematics Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz University

In this article we investigate the flow of Sutterby liquid due to rotating stretchable disk. Mass and heat transport are analyzed through Brownian diffusion and thermophoresis. Further the effects of magnetic field, chemical reaction and heat source are also accounted. We employ transformation procedure to obtain a system of nonlinear ODE's. This system is numerically solved by Built-in-Shooting method. Impacts of different involved parameter on velocity, temperature and concentration are described. Velocity, concentration and temperature gradients are numerically computed. Obtained results show that velocity is reduced through material parameter. Temperature and concentration are enhanced with thermophoresis parameter.

关键词： sutterby nanoliquid magnetic field chemical reaction rotating stretchable disk heat generation

Computational modeling and analysis for the effect of magnetic field on rotating stretched disk flow with heat transfer

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Propulsion and Power Research 2021年第1期10卷 48-57页

作者： salman ahmad T.Hayat A.Alsaedi Habib Ullah Faisal Shah Department of Mathematics Quaid-I-Azam University45320Islamabad44000Pakistan Nonlinear Analysis and Applied Mathematics(NAAM)Research Group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityP.O.Box 80257Jeddah21589Saudi Arabia

Time-dependent viscous fluid flow due to a stretchable rotating disk is *** field is applied in vertical direction to the *** equation is assisted with Joule heating *** system of PDE's is transformed to dimensionless form by suitable *** of the numerical techniques known as finite difference scheme is adopted to tackle the given dimensionless partial differential *** method results in a system of simple algebraic *** unknown function is analyzed inside domain of *** this technique of solution,a system is subdivided into many smaller parts called finite *** obtained simpler algebraic equations are then assembled to form a system of equations which governs the original *** method is used to get approximate solution by reducing the error *** of pertinent variables on surface drag force,temperature,velocity and heat transfer rate are shown *** obtained outcomes guarantee that velocity decreases for Hartmann number while it enhances with Reynolds *** increases for higher Prandtl,Eckert and Hartmann *** friction boosts for larger values of Hartmann *** number enhances with Hartmann number.

关键词： Finite difference scheme Magnetic field System of partial differential equations Joule heating Rotating stretchable disk