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Communications in Theoretical Physics 2023年第2期75卷 18-27页

作者： Weaam Alhejaili Alvaro H Salas S A el-tantawy Department of Mathematical Sciences College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia Department of Mathematics and Statistics Universidad Nacional de ColombiaFIZMAKO Research GroupColombia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia

In this investigation,some different approaches are implemented for analyzing a generalized forced damped complex Duffing oscillator,including the hybrid homotopy perturbation method(H-HPM),which is sometimes called the Krylov-Bogoliubov-Mitropolsky(KBM)method and the multiple scales method(MSM).All mentioned methods are applied to obtain some accurate and stable approximations to the proposed problem without decoupling the original *** obtained approximations are discussed graphically using different numerical values to the relevant ***,all obtained approximate solutions are compared with the 4thorder Runge-Kutta(RK4)numerical *** maximum residual distance error(MRDE)is also estimated,in order to verify the high accuracy of the obtained analytic approximations.

关键词： complex Duffing oscillators forced damped complex oscillator multiple scales method KBM method

Formation of Alfvénic supernonlinear waves in a plasma containing double spectral distributed electrons

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Communications in Theoretical Physics 2024年第12期76卷 140-149页

作者： a a el-tantawy W F el-Taibany S K el-Labany A M Abdelghany Department of Physics Faculty of Science Damietta University Center of Space Research and Its Application Damietta University

The characteristics of nonlinear and supernonlinear Alfvén waves propagating in a multicomponent plasma composed of a double spectral electron distribution and positive and negative ions were investigated. The Sagdeev technique was employed, and an energy equation was derived. Our findings show that the proposed system reveals the existence of a double-layer solution, periodic, supersoliton, and superperiodic waves. The phase portrait and potential analysis related to these waves were investigated to study the main features of existing waves. It was also found that decreasing the electron temperature helps the superperiodic structure to be excited in our plasma model. Our results help interpret the nonlinear and supernonlinear features of the recorded Alfvén waves propagating in the ionosphere D-region.

关键词： Alfvén waves double spectral distribution nonlinear waves Sagdeev method supernonlinear waves

A new approach for modelling the damped Helmholtz oscillator:applications to plasma physics and electronic circuits

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Communications in Theoretical Physics 2021年第3期73卷 119-130页

作者： S A el-tantawy Alvaro H Salas M R Alharthi Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia Department of Mathematics Universidad National de ColombiaUniversidad National de Colombia-Nubia Campus Derpartment of Mathematics and Statistics FIZMAKO Research GroupColombia Department of Mathematics and Statistics College of ScienceTaif UniversityPO Box 11099Taif 21944Saudi Arabia

In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic *** exact solution for undamped HE(integrable case)and approximate/semi-analytical solution to the damped HE(non-integrable case)are given for any arbitrary initial *** a special case,the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is *** general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic *** addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in ***,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two ***,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be *** real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model.

关键词： damped and undamped Helmholtz equation Korteweg-de Vries type equation plasma oscillations nonlinear RLC circuits Weierstrass ellliptic function periodical solution

Novel anlytical solution to the damped Kawahara equation and its application for modeling the dissipative nonlinear structures in a fluid medium

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Journal of Ocean Engineering and Science 2022年第5期7卷 492-497页

作者： Noufe H.Aljahdaly S.A.el-tantawy Department of Mathematics Faculty of Sciences and Arts-Rabigh campusKing Abdulaziz UniversityJeddahSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia

A novel approximate analytical solution to the linear damped Kawahara equation using a suitable hypothesis is reported for the first *** on the exact solutions(such as solitary waves,cnoidal waves,etc.)of the undamped Kawahara equation,the dissipative nonlinear structures like dissipative solitons and cnoidal waves are *** obtained solution is considered a general solution,i.e.,it can be applied for studying the properties of all dissipative traveling waves described by the linear damped Kawahara *** technique is not limited to solve the linear damped Kawahara equation only,but it can be used for solving a large number of non-integrable evolution equations related to the realistic natural ***,the maximum global residual error in the whole space-time domain is estimated for checking the accuracy of the obtained *** obtained solutions can help many researchers in explaining the ambiguities about the mechanisms of propagation of nonlinear waves in complex systems such as seas,oceans,plasma physics,and much more.

关键词： Semi-analytical solutions Damped Kawahara equation A collisional plasma Dissipative Kawahara solitons and cnoidal waves

The phase shift analysis of the colliding dissipative KdV solitons

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Journal of Ocean Engineering and Science 2022年第6期7卷 521-527页

作者： Wedad Albalawi S.A.el-tantawy Sadah A.Alkhateeb Department of Mathematical Sciences College of SciencePrincess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia Mathematics Department Faculty of ScienceUniversity of JeddahJeddahSaudi Arabia

In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are *** extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)*** dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact ***,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative *** residual error is estimated for checking the accuracy of the new obtained *** approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the *** impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is *** obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc.

关键词： Dissipative soliton collisions Damped Korteweg-de Vries equation The extended Poincare-Lighthill-Kuo method The temporal phase shifts

Multiple scales method for analyzing a forced damped rotational pendulum oscillatorwithgallows

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Communications in Theoretical Physics 2024年第5期76卷 58-67页

作者： Haifa A Alyousef Alvaro H Salas B M Alotaibi S A el-tantawy Department of Physics College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia Department of Mathematics and Statistics Universidad Nacional de ColombiaFIZMAKO Research GroupColombia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversityAl-Baha 1988Saudi Arabia

This study reports the analytical solution for a generalized rotational pendulum system with gallows and periodic excited *** multiple scales method(MSM)is applied to solve the proposed *** types of rotational pendulum oscillators are studied and talked about in *** include the forced damped rotating pendulum oscillator with gallows,the damped standard simple pendulum oscillator,and the damped rotating pendulum oscillator without *** MSM first-order approximations for all the cases mentioned are derived in *** obtained results are illustrated with concrete numerical *** first-order MSM approximations are compared to the fourth-order Runge-Kutta(RK4)numerical ***,the maximum error is estimated for the first-order approximations obtained through the MSM,compared to the numerical approximations obtained by the RK4 ***,we conducted a comparative analysis of the outcomes obtained by the used method(MSM)and He-MSM to ascertain their respective levels of *** proposed method can be applied to analyze many strong nonlinear oscillatory equations.

关键词： rotational pendulum system multiple scales method approximate solution damped oscillations forced pendulum with gallows he-multiple scales method

Optimal analytical and numerical approximations to the(un)forced(un)damped parametric pendulum oscillator

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Communications in Theoretical Physics 2022年第10期74卷 16-29页

作者： Haifa A Alyousef M R Alharthi Alvaro H Salas S A el-tantawy Department of physics College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia Department of Mathematics and Statistics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Mathematics and Statistics Universidad Nacional de ColombiaFIZMAKO Research GroupSede ManizalesColombia Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Research Center for Physics(RCP) Department of PhysicsFaculty of Science and ArtsAl-MikhwahAl-Baha UniversitySaudi Arabia

The(un)forced(un)damped parametric pendulum oscillator(PPO)is analyzed analytically and numerically using some simple,effective,and more accurate *** the first technique,the ansatz method is employed for analyzing the unforced damped PPO and for deriving some optimal and accurate analytical approximations in the form of angular Mathieu *** the second approach,some approximations to(un)forced damped PPO are obtained in the form of trigonometric functions using the ansatz *** the third approach,He’s frequency-amplitude principle is applied for deriving some approximations to the(un)damped *** the forth approach,He’s homotopy technique is employed for analyzing the forced(un)damped PPO *** the fifth approach,the p-solution Method,which is constructed based on Krylov–Bogoliúbov Mitropolsky method,is introduced for deriving an approximation to the forced damped *** the final approach,the hybrid Padé-finite difference method is carried out for analyzing the damped PPO *** proposed techniques are compared to the fourth-order Runge–Kutta(RK4)numerical ***,the global maximum residual distance error is estimated for checking the accuracy of the obtained *** proposed methodologies and approximations can help many researchers in studying and investigating several nonlinear phenomena related to the oscillations that can arise in various branches of science,*** and oscillations in plasma physics.

关键词： parametric pendulum equation Ansatz method He’s frequency-amplitude principle He’s homotopy technique Krylov-Bogoliúbov Mitropolsky method the hybrid Padé-finite difference method

On the analytical soliton approximations to fractional forced Korteweg-de Vries equation arising in fluids and plasmas using two novel techniques

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Communications in Theoretical Physics 2024年第8期76卷 1-10页

作者： Weaam Alhejaili Emad A Az-Zo’bi Rasool Shah S A el-tantawy Department of Mathematical Sciences College of SciencePrincess Nourah bint Abdulrahman UniversityPO Box 84428Riyadh 11671Saudi Arabia Department Mathematics and Statistics Mutah UniversityAl-KarakJordan Department of Computer Science and Mathematics Lebanese American UniversityBeirutLebanon Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt Department of Physics Faculty of ScienceAl-Baha UniversityAl-Baha P.O.Box 1988Saudi Arabia

The current investigation examines the fractional forced Korteweg-de Vries(FF-KdV) equation,a critically significant evolution equation in various nonlinear branches of science. The equation in question and other associated equations are widely acknowledged for their broad applicability and potential for simulating a wide range of nonlinear phenomena in fluid physics, plasma physics, and various scientific domains. Consequently, the main goal of this study is to use the Yang homotopy perturbation method and the Yang transform decomposition method, along with the Caputo operator for analyzing the FF-KdV equation. The derived approximations are numerically examined and discussed. Our study will show that the two suggested methods are helpful, easy to use, and essential for looking at different nonlinear models that affect complex processes.

关键词： forced fractional KdV equation Caputo operator Yang homotopy perturbation method Yang transform decomposition method solitons

Toxoplasma gondii infection among chronic hepatitis C patients:A casecontrol study

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Asian Pacific Journal of Tropical Medicine 2014年第8期7卷 589-593页

作者： Hala A el-Nahas Nora L el-tantawy Raghda E Farag Argaya MA Alsalem Faculty of Medicine Mansoura University Faculty of Science Sebha Unirersity

Objective:To determine the detection rate of anti-Toxoplasma gondii(***) IgG and IgM in chronic HCV patients attending the Department of Tropical Medicine Mansoura University hospital in ***:This study included 120 adult chronic HCV patients.81 decompensate cirrhosis(late-stage)and 39 chronic HCV non cirrhotic patients(early-stage) and40 healthy blood donors as *** samples uere examined for anti-Toxoplasma IgM and anti-Toxoplasma IgG antibodies by ***-time RT-polymerase chain reaction assay was done for quantitation of hepatitis C ***:*** IgG antibodies were detected in 75(92.6%) of 81 late-stage cirrhotic patients.30(76.9%) of the 39 chronic HCV non cirrhotic patients(early-Stage) and in 6(15ft) of 40 controls with statistically significant difference(Pelation between stage of fibrosis and IgM or IgG antibodies positivity in our studied groups(P=0.526).High IgG levels significantly correlated with high viral load(P=0.026).Conclusions:Our findings suggest that the serious opportunistic *** infection represent a potential significant risk for chronic HCV *** should be considered in their investigations and follow-up.

关键词： Toxoplasma gondii HCV elISA Real-time PCR

Highly efficient enzymolysis and fermentation of corn stalk into L-lactic acid by enzyme-bacteria friendly ionic liquid pretreatment

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Green Chemical Engineering 2022年第4期3卷 321-327页

作者： Yongqing Yang Yuehai Wang Xingmei Lu Xu Zheng Dongxia Yan Jiayu Xin Ibrahim el-tantawy el-Sayed Ying Kang Jiming Yang Beijing Key Laboratory of Ionic Liquids Clean Process Key Laboratory of Green Process EngineeringInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemistry and Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Department of Chemistry Faculty of ScienceMenoufia UniversityShebin El-KomMenoufia32511Egypt Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China

Ionic liquids(ILs)have been widely used in the pretreatment of ***,the effects of residual ILs on the enzymolysis and fermentation of biomass are still ***,a large quantity of water-washing is usually followed after biomass pretreatment to eliminate the inhibition of residual ILs on subsequent hydrolysis and fermentation *** this work,the effect of choline glycine([Ch][Gly])concentration on the activity of cellulase and Bacillus *** P38 was systematically investigated to explore the impacts of residual ILs on enzymolysis and *** results confirmed that the activities of them were almost not inhibited in low concentrations(less than 0.5 wt%)of[Ch][Gly].Under optimal pretreatment conditions,the maximum cellulose digestibility was 99.23%.Enzymatic hydrolysate was suitable for L-lactic acid fermentation without appreciable inhibition,and the highest sugar-acid conversion rate of 96.33%was obtained by simplified *** work provides an economic route to produce fermentable sugar and L-lactic acid,which shows an industrial application prospect in lignocellulosic biorefinery.

关键词： Corn stalk Biocompatibility Choline glycine Enzymatic hydrolysis L-lactic acid fermentation