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Nonlinear ion-acoustic solitary waves in an electron-positron-ion plasma with relativistic positron beam

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Chinese physics B 2018年第10期27卷 471-476页

作者： Ridip Sarma Amar p misra Nirab C Adhikary Department of Mathematics University of Science and TechnologyTechno CityKhanaparaBaridua9th MileRi-BhoiMeghalayaIndia Department of Mathematics Siksha BhavanaVisva-Bharati University physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan PathPaschim BoragaonGarchukGuwahati-781035AssamIndia

The propagation characteristics of nonlinear ion–acoustic（IA） solitary waves（SWs） are studied in thermal electron–positron–ion plasma considering the effect of relativistic positron beam. Starting from a set of fluid equations and using the reductive perturbation technique, we derive a Korteweg–de Vries（KdV） equation which governs the evolution of weakly nonlinear IA SWs in relativistic beam driven plasmas. The properties of the IA soliton are studied, and it is shown that the presence of relativistic positron beam significantly modifies the characteristics of IA solitons.

关键词： electron-positron-ion plasma relativistic effect ion-acoustic wave homogeneous balance method

polarized Debye Sheath in Degenerate plasmas

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Communications in Theoretical physics 2019年第11期71卷 1341-1345页

作者： M.Shahmansouri A.p.misra Department of physics Faculty of ScienceArak UniversityArakP.O.Box 38156-8-8349Iran Department of Mathematics Siksha BhavanaVisva-Bharati(A Central University)Santiniketan-731235India

The force on a charged dust grain in a plasma due to polarization of thermal ions and degenerate electrons around the grain is derived in the limits of weakly relativistic and ultra-relativistic degeneracy of electrons. It is found that in both these cases, the magnitude of the polarization force is enhanced compared to that in classical plasmas. The influence of this force on dust-acoustic(DA) modes is examined and discussed. It is shown that the DA wave frequency in degenerate plasmas is significantly reduced compared to the classical DA mode.

关键词： degenerate plasma polarization force dust acoustic waves

Spread and control of COVID-19:A mathematical model

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第3期13卷 121-148页

作者： O.p.misra Omprakash Singh Sisodiya School of Mathematics and Allied Sciences Jiwaji University Gwalior 474011Madhya PradeshIndia

A mathematical model is proposed in this paper to study the transmission and control of *** mathematical model is formulated using system of nonlinear ordinary differential *** model includes disease-related parameters such as contact rate,disease-induced death rates,immigration rate and transition rates along with parameters for control measures such as implementation of social distancing practices,isolation and quarantine *** the stability analysis of the model,it is shown that if the social distancing is practiced by the large number of susceptible population,then the disease will not spread,and it may eventually die ***,it is derived from the analysis of the model that if most of the infected populations are isolated or quarantined,then the spread of the disease can be eventually ***,from the analysis of the model,it is observed that if there is constant immigration of asymptomatic infected persons,then the disease will continue to spread and will remain *** controlling the disease,two more parameters,that is,vaccination and testing rates,are introduced in the original mathematical model and from the numerical analysis of this model,it has been shown that the control strategy involving vaccination and testing in combination can have synergistic effect for minimizing the COVID-19 infected cases.

关键词： COVID-19 social distancing isolation quarantine immigration mathematical model

SIRS epidemic modeling using fractional-ordered differential equations:Role of fear effect

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International Journal of Biomathematics 2024年第5期17卷 79-100页

作者： Shiv Mangal O.p.misra Joydip Dhar School of Mathematics and Allied Sciences Jiwaji University GwaliorMadhya PradeshIndia Department of Mathematics Post Graduate College BinaMadhya PradeshIndia Department of Applied Sciences Atal Bihari Vajpayee-Indian Institute of Information Technology and Management GwaliorMadhya PradeshIndia

In this paper,an SIRS epidemic model using Grunwald-Letnikov fractional-order derivative is formulated with the help of a nonlinear system of fractional differential equations to analyze the effects of fear in the population during the outbreak of deadly infectious *** criteria for the spread or extinction of the disease are derived and discussed on the basis of the basic reproduction *** condition for the existence of Hopf bifurcation is discussed considering fractional order as a bifurcation ***,using the Grunwald-Letnikov approximation,the simulation is carried out to confirm the validity of analytic results *** the real data of COVID-19 in India recorded during the second wave from 15 May 2021 to 15 December 2021,we estimate the model parameters and find that the fractional-order model gives the closer forecast of the disease than the classical *** the analytical results and numerical simulations presented in this study suggest different policies for controlling or eradicating many infectious diseases.

关键词： SIRS epidemic model fear effect Mittag-Leffler function Hopf bifurcation parameter estimation

Modeling and analysis of the transmission dynamics of mosquito-borne disease with environmental temperature fluctuation

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International Journal of Modeling, Simulation, and Scientific Computing 2022年第3期13卷 31-73页

作者： O.p.misra Joydip Dhar Omprakash Singh Sisodiya School of Mathematics and Allied Sciences Jiwaji University Gwalior 474011M.P.India Department of Applied Sciences ABV-Indian Institute of Information Technology and Management Gwalior 474015 M.P.India

Most of the vector-borne diseases show a clear dependence on seasonal variation,including climate *** this paper,we proposed a nonautonomous mathematical model consisting of a periodic system of nonlinear differential *** the proposed model,the realistic functional forms for the different temperature-dependent parameters are *** autonomous system of the proposed model is also *** nontrivial solution of the autonomous model is locally asymptotically stable if R0point of the autonomous model exists when R0>1 and proved that endemic solution is linearly stable when R0>*** nonautonomous model is shown to have a nontrivial disease-free periodic state,which is globally asymptotically stable whenever temperature-dependent reproduction number is less than *** is observed that a unique positive endemic periodic solution of the nonautonomous system exists only when a temperature-dependent reproduction number greater than unity,which makes for the persistence of the *** simulation has been carried out to support the analytical results and shows the effects of temperature variability in the life span of mosquitoes as well as the persistence of the disease.

关键词： Mosquito-borne disease seasonality temperature-dependent reproduction number periodic steady states

Dynamics of one-prey two-predator system with square root functional response and time lag

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International Journal of Biomathematics 2015年第3期8卷 23-44页

作者： O. p. misra poonam Sinha Chhatrapal Singh School of Mathematics and Allied SciencesJiwaji University Gwalior (M.P.)-474011 India Department of MathematicsS. M. S. Govt. Model Science College Gwalior (M.p.)-474010 India

Animals grouping together is one of the most interesting phenomena in population dynamics and different functional responses as a result of prey-predator forming groups have been considered by many authors in their models. In the present paper we have considered a model for one prey and two competing predator populations with time lag and square root functional response on account of herd formation by prey. It is shown that due to the inclusion of another competing predator, the underlying system without delay becomes more stable and limit cycles do not occur naturally. However, after considering the effect of time lag in the basic system, limit cycles appear in the case of all equilibrium points when delay time crosses some critical value. From the numerical simulation, it is observed that the length of delay is minimum when only prey population survives and it is maximum when all the populations coexist.

关键词： Stability square root functional response Hopf bifurcation time delay.

Laser optogalvanic investigations of the Neon 6302 A transition

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原子与分子物理学报 2007年第B8期24卷 102-104页

作者： HAN Xianming L pOZDIN V HARIDASS C misra p Department of physics ＆ Astronomy Butler University Indianapolis IN 46208 CLOE Comell University Ithaca NY 14850 Department of physical Sciences Belfry School Belfry KY 41514 Department of physics ＆ Astronomy Howard University Washington D. C20059

The optogalvanic effect of neon, in the presence of CO gas, has been specifically investigated for the 630.2 nm transition. Our theoretical model, based on rate equations, predicts well the observed signals as a sum o... 详细信息

关键词：光电效应信号波形蒙特卡罗法激光

Kadomtsev–petviashvili(Kp) Burgers Equation in Dusty Negative Ion plasmas:Evolution of Dust-Ion Acoustic Shocks

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Communications in Theoretical physics 2014年第12期61卷 875-880页

作者： A.N.Dev J.Sarma M.K.Deka A.p.misra N.C.Adhikary Department of Science and Humanities College of Science and Technology RUB Bhutan Department of Mathematics R.G.Baruah College Guwahati-781025 Assam India Centre of plasma physics Tepesia Sonapur Kamrup Assam India Department of Mathematics Siksha Bhavana Visva-Bharati University Santiniketan-731 235 India physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim BoragaonGarchuk Guwahati – 781035 Assam India

We study the nonlinear propagation of dust-ion acoustic(DIA) shock waves in an un-magnetized dusty plasma which consists of electrons, both positive and negative ions and negatively charged immobile dust grains. Starting from a set of hydrodynamic equations with the ion thermal pressures and ion kinematic viscosities included, and using a standard reductive perturbation method, the Kadomtsev–petviashivili–Burgers(K-p-Burgers) equation is derived, which governs the evolution of DIA shocks. A stationary solution of the K-p-Burgers equation is obtained and its properties are analysed with different plasma number densities, ion temperatures and masses. It is shown that a transition from shocks with negative potential to positive one occurs depending on the negative ion concentration in the plasma and the obliqueness of propagation of DIA waves.

关键词： dusty plasmas Shock wave reductive perturbation technique K-p burgers equation

Comparative Analysis of Continuous versus Intermittent proton pump Inhibitor Therapy in patients with Upper Gastrointestinal Bleeding Due to Ulcers

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Open Journal of Gastroenterology 2024年第3期14卷 99-107页

作者： Abraamyan Feruza misra p. Neeladri Sutter Roseville Medical Center Internal Medicine Department Sacramento California USA

Upper gastrointestinal bleeding (UGIB) presents as a prevalent clinical challenge, with annual incidence rates ranging from 80 to 150 cases per 100,000 individuals. Guidelines for managing patients with UGIB due to bleeding ulcers recommend a continuous infusion of proton pump inhibitors (ppI). However, studies comparing intermittent dosing of ppI therapy show that this regimen achieves similar clinical benefits. If the clinical efficacy remains equivalent, intermittent dosing will be more cost-effective for patients and the health care system. Our research study aims to analyze the comparative effectiveness of intermittent versus continuous ppI therapy after endoscopic treatment in patients with UGIB, focusing on such endpoints as rebleeding risk at 3-and 7-day mortality rates. Methods: Resources searched included MEDLINE, EMBASE, pUBMED, and the Cochrane Central Register of Controlled Trials databases from January 2010 through December 2023 with the inclusion of meta-analysis, systematic review, review, or ACG guideline recommendations. Results of the analysis show how recommendations regarding high vs. low ppI regimen changed over time: from no difference in regimen in 2010 to recommending continuous regimen in 2012 to declaring insufficient evidence between choosing one regimen over another in 2013 to determine that both regimens were comparable to each other in 2014-2018 and finally to recommending both regimens in 2021. To conclude, our review shows that in patients with bleeding ulcers and high-risk endoscopic findings, intermittent ppI therapy is non-inferior to continuous ppI infusion for three days, seven days bleeding risk or mortality rates;however, it remains challenging to determine the most optimal intermittent regimen due to heterogeneity of RCTs included in meta-analyses, and further trials will need to be performed.

关键词： Upper Gastrointestinal Bleeding ppI Continuous Intermittent Bolus Regimens Review