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Attitude dynamics and control of spacecraft using geomagnetic Lorentz force

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Research in Astronomy and Astrophysics 2015年第1期15卷 127-144页

作者： Yehia A.Abdel-Aziz muhammad shoaib National Research Institute of Astronomy and Geophysics (NRIAG) Helwan Cairo 11721Egypt University of Hail Department of Mathematics PO BOX 2440 Kingdom of Saudi Arabia

Attitude stabilization of a charged rigid spacecraft in Low Earth Orbit using torques due to Lorentz force in pitch and roll directions is considered. A spacecraft that generates an electrostatic charge on its surface in the Earth’s magnetic field will be subject to perturbations from the Lorentz force. The Lorentz force acting on an electrostatically charged spacecraft may provide a useful thrust for controlling a spacecraft’s orientation. We assume that the spacecraft is moving in the Earth’s magnetic field in an elliptical orbit under the effects of gravitational, geomagnetic and Lorentz torques. The magnetic field of the Earth is modeled as a non-tilted dipole.A model incorporating all Lorentz torques as a function of orbital elements has been developed on the basis of electric and magnetic fields. The stability of the spacecraft orientation is investigated both analytically and numerically. The existence and stability of equilibrium positions is investigated for different values of the charge to mass ratio（α＊）. Stable orbits are identified for various values of α＊. The main parameters for stabilization of the spacecraft are α＊and the difference between the components of the moment of inertia for the spacecraft.

关键词： space vehicles atmospheric effects celestial mechanics kinematics and dynamics

Equilibria of a charged artificial satellite subject to gravitational and Lorentz torques

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Research in Astronomy and Astrophysics 2014年第7期14卷 891-902页

作者： Yehia A.Abdel-Aziz muhammad shoaib National Research Institute of Astronomy and Geophysics (NRIAG) HelwanCairo 11721Egypt University of Hail Department of MathematicsPO Box 2440Kingdom of Saudi Arabia

The attitude dynamics of a rigid artificial satellite subject to a gravity gradient and Lorentz torques in a circular orbit are considered. Lorentz torque is developed on the basis of the electrodynamic effects of the Lorentz force acting on the charged satellite＇s surface. We assume that the satellite is moving in a Low Earth Orbit in the geomagnetic field, which is considered to be a dipole. Our model of torque due to the Lorentz force is developed for an artificial satellite with a general shape, and the nonlinear differential equations of Euler are used to describe its attitude orientation. All equilibrium positions are determined and conditions for their existence are *** numerical results show that the charge q and radius ρ0of the center of charge for the satellite provide a certain type of semi-passive control for the attitude of the satellite. The technique for this kind of control would be to increase or decrease the electrostatic screening on the satellite. The results obtained confirm that the change in charge can affect the magnitude of the Lorentz torque, which can also affect control of the satellite. Moreover, the relationship between magnitude of the Lorentz torque and inclination of the orbit is investigated.

关键词： space vehicles -- atmospheric effects -- celestial mechanics -- kine-matics and dynamics

A reliable numerical analysis for stochastic gonorrhea epidemic model with treatment effect

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International Journal of Biomathematics 2019年第6期12卷 221-246页

作者： Ali Raza muhammad shoaib Arif muhammad Ualiq Department of Mathematics Stochastic Analysis and Optimization Research Group Air University PAF Complex E-9 Islamabad 44000PedralPakistan Faculty of Engineering.University of Central PunjabLahore 54000 PunjabPakistan

The phenomena of disease spread are unpredictable in nature due to random mixing of individuals in a *** is of more significance to include this randomness while modeling infectious *** epidemics including tlieir stochastic behavior could be a more realistic approach in many *** thus paper,a stochastic gon orrhea epidemic model with treatment effect has been analyzed *** solution of stochastic model is presented in comparison with its deterministic *** dynamics of the gonorrhea disease is governed by a threshold quantity Ai called basic reproductive ***.A11 shows the persistence of disease in *** standard numerical schemes like Euler *** Euler and stochastic Rurige Kutta are highly dependent on step size and do not behave well in certain scenarios.A competitive non-standard finite dif ference numerical scheme in stochastic setting is proposed,which is independent of step size and remains consistent with the corresponding deterministic model.

关键词： Gonorrhea disease stochastic differential equations stochastic numerical schemes

Advancements in Numerical Solutions:Fractal Runge-Kutta Approach to Model Time-Dependent MHD Newtonian Fluid with Rescaled Viscosity on Riga Plate

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Computer Modeling in Engineering & Sciences 2024年第11期141卷 1213-1241页

作者： muhammad shoaib Arif Kamaleldin Abodayeh Yasir Nawaz Department of Mathematics and Sciences College of Humanities and SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Mathematics Air UniversityPAF Complex E-9Islamabad44000Pakistan

Fractal time-dependent issues in fluid dynamics provide a distinct difficulty in numerical analysis due to their complex characteristics,necessitating specialized computing techniques for precise and economical *** study presents an innovative computational approach to tackle these *** main focus is applying the Fractal Runge-Kutta Method to model the time-dependent magnetohydrodynamic(MHD)Newtonian fluid with rescaled viscosity flow on Riga *** efficient computational scheme is proposed for handling fractal time-dependent problems in flow *** scheme is comprised of three stages and constructed using three different time *** stability of the scheme is shown by employing the Fourier series analysis to solve scalar *** scheme’s convergence is guaranteed for a time fractal partial differential equations *** scheme is applied to the dimensionless fractal heat and mass transfer model of incompressible,unsteady,laminar,Newtonian fluid with rescaled viscosity flow over the flat and oscillatory Riga plates under the effects of space-and temperature-dependent heat *** first-order back differences discretize the continuity *** results show that skin friction local Nusselt number declines by raising the coefficient of the temperature-dependent term of heat source and Eckert *** numerical simulations provide valuable insights into fluid dynamics,explicitly highlighting the influence of the temperature-dependent coefficient of the heat source and the Eckert number on skin friction and local Nusselt number.

关键词： Fractal scheme stability convergence fractal Newtonian fluid with rescaled viscosity fluid heat generation

Aluminium and cerium co-doped ZnO nanoparticles:Facile and inexpensive synthesis and visible light photocatalytic performances

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Journal of Rare Earths 2021年第2期39卷 151-159页

作者： Irshad Ahmad muhammad shoaib Akhtar Ejaz Ahmed Mukhtar Ahmad Department of Physics Bahauddin Zakariya UniversityMultan60800Pakistan School of Computer and Communication Lanzhou University of TechnologyLanzhou 730000China

Facile combustion route synthesized Al and Ce co-doped ZnO nanoparticles photocatalysts were characterized using XRD,SEM,BET,EDS,UV-visible DRS,PL,photocurrent and EIS *** and SEM analyses identify that crystallite and particle size is reduced from 13.26 to 11.88 nm with introduction of Al and Ce into ZnO which assists inhibiting the recombination of photo generated charge *** DRS spectra indicate that optical assimilation of ZnO is significantly increased to visible region(-406 nm)and band gap reduces from 3.18 to 3.06 eV with introduction of Al and Ce *** impedance spectroscopy analysis under visible light illumination confirms the enhancement in visible light activity of Al and Ce co-doped ZnO nanoparticles as *** enhanced activity of Al and Ce co-doped ZnO photocatalyst can be ascribed to enhanced light assimilation,high surface area and efficient charge transfer *** results reveal that by incorporating precise amount of Al(~2%)and Ce(~2%)into ZnO,a highly efficient catalyst can be synthesized that have degraded almost 95%methyl orange(MO)dye in just 45 ***,the influence of various operational parameters such as solution pH,catalyst dose,dye concentration,airflow rate and light intensity on photodecomposition of MO was *** rmore,a possible mechanism for Al and Ce modified ZnO was proposed and designed photocatalysts demonstrates good stability in aqueous medium.

关键词： Nanoparticles ZnO Combustion MO decomposition PL Rare earths

Solution of Algebraic Lyapunov Equation on Positive-Definite Hermitian Matrices by Using Extended Hamiltonian Algorithm

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Computers, Materials & Continua 2018年第2期54卷 181-195页

作者： muhammad shoaib Arif Mairaj Bibi Adnan Jhangir Department of Mathematics Air UniversityPAF ComplexE-9IslamabadPakistan Department of Mathematics Comsats Institute of Information TechnologyPark RoadChak-ShahzadIslamabadPakistan Department of Mathematics Comsats Institute of Information TechnologyWah CanttPakistan

This communique is opted to study the approximate solution of the Algebraic Lyapunov equation on the manifold of positive-definite Hermitian *** choose the geodesic distance between􀀀AHX􀀀XA and P as the cost function,and put forward the Extended Hamiltonian algorithm(EHA)and Natural gradient algorithm(NGA)for the ***,several numerical experiments give you an idea about the effectiveness of the proposed *** also show the comparison between these two algorithms EHA and *** results are provided and analyzed *** also conclude that the extended Hamiltonian algorithm has better convergence speed than the natural gradient algorithm,whereas the trajectory of the solution matrix is optimal in case of Natural gradient algorithm(NGA)as compared to Extended Hamiltonian Algorithm(EHA).The aim of this paper is to show that the Extended Hamiltonian algorithm(EHA)has superior convergence properties as compared to Natural gradient algorithm(NGA).Upto the best of author’s knowledge,no approximate solution of the Algebraic Lyapunov equation on the manifold of positive-definite Hermitian matrices is found so far in the literature.

关键词： Information geometry algebraic lyapunov equation positive-definite hermitianmatrix manifold natural gradient algorithm extended hamiltonian algorithm

A Hybrid SIR-Fuzzy Model for Epidemic Dynamics:A Numerical Study

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3417-3434页

This study focuses on the urgent requirement for improved accuracy in diseasemodeling by introducing a newcomputational framework called the Hybrid SIR-Fuzzy *** integrating the traditional Susceptible-Infectious-Recovered(SIR)modelwith fuzzy logic,ourmethod effectively addresses the complex nature of epidemic dynamics by accurately accounting for uncertainties and imprecisions in both data and model *** main aim of this research is to provide a model for disease transmission using fuzzy theory,which can successfully address uncertainty in mathematical *** main emphasis is on the imprecise transmission rate parameter,utilizing a three-part description of its membership *** enhances the representation of disease processes with greater complexity and tackles the difficulties related to quantifying uncertainty in mathematical *** investigate equilibrium points for three separate scenarios and perform a comprehensive sensitivity analysis,providing insight into the complex correlation betweenmodel parameters and epidemic *** order to facilitate a quantitative analysis of the fuzzy model,we propose the implementation of a resilient numerical *** convergence study of the scheme demonstrates its trustworthiness,providing a conditionally positive solution,which represents a significant improvement compared to current forward Euler *** numerical findings demonstrate themodel’s effectiveness in accurately representing the dynamics of disease ***,when the mortality coefficient rises,both the susceptible and infected populations decrease,highlighting the model’s sensitivity to important epidemiological ***,there is a direct relationship between higher Holling type rate values and a decrease in the number of individuals who are infected,as well as an increase in the number of susceptible *** correlation offers a significant understanding of how many elements affect the con

关键词： Fuzzy-based model sensitivity equilibriumpoints proposed numerical scheme convergence and stability analysis

Computational Modeling of Reaction-Diffusion COVID-19 Model Having Isolated Compartment

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Computer Modeling in Engineering & Sciences 2023年第5期135卷 1719-1743页

作者： muhammad shoaib Arif Kamaleldin Abodayeh Asad Ejaz Department of Mathematics and Sciences College of Humanities and SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Mathematics Air UniversityPAF Complex E-9Islamabad44000Pakistan

Cases of COVID-19 and its variant omicron are raised all across the *** most lethal form and effect of COVID-19 are the omicron version,which has been reported in tens of thousands of cases daily in numerous *** WHO(World health organization)records on 30 December 2021,the cases of COVID-19 were found to be maximum for which boarding individuals were found 1,524,266,active,recovered,and discharge were found to be 82,402 and 34,258,778,*** there were 160,989 active cases,33,614,434 cured cases,456,386 total deaths,and 605,885,769 total samples *** far,1,438,322,742 individuals have been *** coronavirus or COVID-19 is inciting panic for several *** is a new virus that has affected the whole *** have introduced certain ways to prevent the *** can lower the danger of infection by reducing the contact rate with other *** crowded places and social events withmany people reduces the chance of one being exposed to the *** deadly COVID-19 spreads *** is thought that the upcoming waves of this pandemicwill be evenmore *** have presented severalmathematical models to study the pandemic and predict future *** need of the hour is to restrict the mobility to control the infection from ***,separating affected individuals from healthy people is essential to control the *** consider the COVID-19 model in which the population is divided into five *** present model presents the population’s diffusion effects on all susceptible,exposed,infected,isolated,and recovered *** reproductive number,which has a key role in the infectious models,is *** equilibrium points and their stability is *** numerical simulations,finite difference(FD)schemes like nonstandard finite difference(NSFD),forward in time central in space(FTCS),and Crank Nicolson(CN)schemes are *** core characteristics

关键词： Reproductive number stability Routh Hurwitz criterion variational matrix NSFD scheme FTCS scheme Crank Nicolson scheme consistency

A Computational Analysis to Burgers Huxley Equation

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Computers, Materials & Continua 2021年第5期67卷 2161-2183页

作者： muhammad Saqib muhammad shoaib Arif Shahid Hasnain Daoud S.Mashat Department of Mathematics Numl UniversityIslamabad44000Pakistan Department of Mathematics Air UniversityIslamabad44000Pakistan Department of Mathematics Air UniversityMultan CampusMultan66000Pakistan Department of Mathematics King Abdulaziz UniversityJeddahSaudi Arabia

The efficiency of solving computationally partial differential equations can be profoundly highlighted by the creation of precise,higher-order compact numerical scheme that results in truly outstanding accuracy at a given *** objective of this article is to develop a highly accurate novel algorithm for two dimensional non-linear Burgers Huxley(BH)*** proposed compact numerical scheme is found to be free of superiors approximate oscillations across discontinuities,and in a smooth ow region,it efciently obtained a high-order *** particular,two classes of higherorder compact nite difference schemes are taken into account and compared based on their computational *** stability and accuracy show that the schemes are unconditionally stable and accurate up to a two-order in time and to six-order in ***,algorithms and data tables illustrate the scheme efciency and decisiveness for solving such non-linear coupled *** is scaled in terms of L_(2) and L_(∞) norms,which validate the approximated results with the corresponding analytical *** investigation of the stability requirements of the implicit method applied in the algorithm was carried *** agreement was constructed under indistinguishable computational *** proposed methods can be implemented for real-world problems,originating in engineering and science.

关键词： Burgers Huxley equation nite difference schemes HOC schemes Thomas algorithm Von-Neumann stability ana