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New Exact Solutions of a Relativistic toda Lattice System

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Chinese Physics Letters 2012年第9期29卷 53-56页

作者： m.t.darvishi F.Khani Department of mathematics Razi UniversityKermanshah 67149Iran

We study the application of the exp-function method to solve a relativistic toda lattice *** reduce the original equation into a convenient form,a suitable transformation is used so that the so-called exp-function method can be *** using the homogeneous balance principle and some further analysis,we succeed in calculating some exact analytic solutions.

关键词： convenient exact calculating

New Exact Solutions to the (2+1)-Dimensional Ablowitz-Kaup-Newell-Segur Equation: modification of the Extended Homoclinic test Approach

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Chinese Physics Letters 2012年第4期29卷 3-6页

作者： mohammad Najafi maliheh Najafi m.t.darvishi Department of Physiology Faculty of MedicineKermanshah University of Medical SciencesKermanshahIran Department of mathematics Razi UniversityKermanshah 67149Iran

By means of modification of the extended homoclinic test approach (mEHtA),we obtain some new exact soliton solutions for the (2+1)-dimensional Ablowitz-Kaup-Newell-Segur (AKNS) equation by obtaining a bilinear closed ... 详细信息

关键词： soliton bilinear exact

A variety of novel closed-form soliton solutions to the family of Boussinesq-like equations with different types

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Journal of Ocean Engineering and Science 2022年第6期7卷 543-554页

作者： Dipankar Kumar Gour Chandra Paul Aly R.Seadawy m.t.darvishi Department of mathematics Bangabandhu Sheikh Mujibur Rahman Science and Technology UniversityGopalganj 8100Bangladesh Department of mathematics University of RajshahiRajshahi 6205Bangladesh mathematics Department Faculty of ScienceTaibah UniversityAl-Madinah Al-MunawarahSaudi Arabia mathematics Department Faculty of ScienceBeni–Suef UniversityBeni SuefEgypt Department of mathematics Razi UniversityKermanshah 67149Iran

this paper deals with the closed-form solutions to the family of Boussinesq-like equations with the effect of spatio-temporal *** sine-Gordon expansion and the hyperbolic function approaches are efficiently applied to the family of Boussinesq-like equations to explore novel solitary,kink,anti-kink,combo,and singular-periodic wave *** attained solutions are expressed by the trigonometric and hyperbolic functions including tan,sec,cot,csc,tanh,sech,coth,csch,and of their *** addition,the mentioned two approaches are applied to the aforesaid models in the sense of Atangana conformable derivative or Beta derivative to attain new wave ***-dimensional and two-dimensional graphs of some of the obtained novel solutions satisfying the corresponding equations of interest are provided to understand the underlying mechanisms of the stated *** the bright wave solutions in terms of Atangana’s conformable derivative,the amplitudes of the bright wave gradually decrease,but the smoothness increases when the fractional parametersαandβ*** the other hand,the periodicities of periodic waves *** attained new wave solutions can motivate applied scientists for engineering their ideas to an optimal level and they can be used for the validation of numerical simulation results in the propagation of waves in shallow water and other nonlinear *** performed approaches are found to be simple and efficient enough to estimate the solutions attained in the study and can be used to solve various classes of nonlinear partial differential equations arising in mathematical physics and engineering.

关键词： Boussinesq-like equations the sine-Gordon expansion approach the hyperbolic function approach Wave solutions Atangana conformable derivative

Numerical investigation for a hyperbolic annular fin with temperature dependent thermal conductivity

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Propulsion and Power Research 2016年第1期5卷 55-62页

作者： m.t.darvishi F.Khani Abdul Aziz Department of mathematics Razi UniversityKermanshah 67149Iran Department of mechanical Engineering School of Engineering and Applied ScienceGonzaga UniversitySpokaneWA 99258USA

An annular fin of hyperbolic profile with temperature dependent thermal conductivity is studied by pseudospectral *** illustrating the effect of fin dimensions,surface convection characteristics and the thermal conductivity parameter on the thermal performance of the fin are presented and discussed.A comparison of the obtained numerical results is made with the closed form analytical solution available in the literature for the case of constant themal *** comparison confirms the high accuracy of numerical *** the thermal conductivity increases with temperature,the effect is to elevate both the temperature distribution in the fin and the fin *** converse is true when the themal conductivity decreases with temperature.

关键词： Hyperbolic annular fin thermal performance Pseudospectral method

A novel approach to study generalized coupled cubic Schrödinger-Korteweg-de Vries equations

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Journal of Ocean Engineering and Science 2024年第1期9卷 13-24页

作者： Lanre Akinyemi P.Veeresha m.t.darvishi Hadi Rezazadeh mehmet Senol Udoh Akpan Department of mathematics Lafayette CollegeEastonPAUSA Department of mathematics Christ Deemed to be UniversityBengaluru 560029India Department of mathematics Razi UniversityKermanshah 67149Iran Faculty of Engineering technology Amol University of Special Modern TechnologiesAmolIran Department of mathematics Nev¸s ehir HacıBekta¸s Veli UniversityNev¸s ehirTurkey Drexel University Department of MathematicsPhiladelphiaPAUSA

the Kortewegde Vries(KdV)equation represents the propagation of long waves in dispersive media,whereas the cubic nonlinear Schrödinger(CNLS)equation depicts the dynamics of narrow-bandwidth wave packets consisting of short dispersive waves.A model that couples these two equations seems in-triguing for simulating the interaction of long and short waves,which is important in many domains of applied sciences and engineering,and such a system has been investigated in recent *** work uses a modified Sardar sub-equation procedure to secure the soliton-type solutions of the generalized cubic nonlinear Schrödinger-Korteweg-de Vries system of *** various selections of arbitrary parameters in these solutions,the dynamic properties of some acquired solutions are represented graph-ically and *** particular,the dynamics of the bright solitons,dark solitons,mixed bright-dark solitons,W-shaped solitons,m-shaped solitons,periodic waves,and other soliton-type *** re-sults demonstrated that the proposed technique is highly efficient and effective for the aforementioned problems,as well as other nonlinear problems that may arise in the fields of mathematical physics and engineering.

关键词： CNLS equation modiﬁed Sardar sub-equation method KdV equation Solitons Long and short waves

Numerical investigation of the flow of a micropolar fuid through a porous channel with expanding or contracting walls

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Propulsion and Power Research 2014年第3期3卷 133-142页

作者： m.t.darvishi F.Khani F.G.Awad A.A.Khidir P.Sibanda Deparment of mathematics Razi UniversityKermanshah 67149Iran School of mathematical Sciences University of KwaZulu-NatalPrivate Bag X01ScottsvillePietermaritzburg 3209South Africa

In this paper,we study the flow of a micropolar fluid in a porous channel with expanding or contracting ***,we use spectral collocation method on the governing equations to obtain an initial approximation for the solution of *** using the obtained initial approximation,we apply the homotopy analysis method to obtain a recursive fomula for the solution.

关键词： Homotopy analysis method Spectral collocation method Series solution micropolar fluid

transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 177-192页

作者： m.NAVEED m.ImRAN t.ASGHAR Z.ABBAS Department of mathematics Division of Science and TechnologyUniversity of Education Department of mathematics The Islamia University of Bahawalpur

this paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAm).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： hybrid nanofluid oscillating curved stretchable sheet gyrotactic microorganism Cattaneo-Christov heat and mass flux chemical reaction analytical solution O368

Stair and Step Soliton Solutions of the Integrable (2+1) and (3+1)-Dimensional Boiti-Leon-manna-Pempinelli Equations

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Communications in theoretical Physics 2012年第12期58卷 785-794页

作者： m.t. darvishi m. Najafi L. Kavitha m. Venkatesh Department of mathematics Razi University Department of Physiology Faculty of Medicine Kermanshah University of Medical Sciences Department of Physics Periyar University Center for Nanoscience and Nanotechnology Periyar University

the multiple exp-function method is a new approach to obtain multiple wave solutions of nonlinear partial differential equations (NLPDEs). By this method one can obtain multi-soliton solutions of NLPDEs. In this paper, using computer algebra systems, we apply the multiple exp-function method to construct the exact multiple wave solutions of a (2+1)-dimensional Boiti-Leon-manna-Pempinelli equation. Also, we extend the equation to a (3+1)-dimensional case and obtain some exact solutions for the new equation by applying the multiple exp-function method. By these applications, we obtain single-wave, double-wave and multi-wave solutions for these equations.

关键词： multiple exp-function method Boiti-Leon-manna-Pempinelli equation exact solution multi-soliton solution

the impact of alpha-fetoprotein (AFP), child-turcotte-pugh (CtP) score and disease staging on the survival of hepatocellular carcinoma (HCC) patients: a retrospective cohort from single oncology center

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Oncology research 2025年第1期33卷 149-160页

作者： Nasser mulla Yousef Katib Asim m Almughamsi Duaa S Alkhayat mohamed mosaad Samir t Alfotih Rawan Alaofi Department of Internal medicine Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Radiology Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Surgery Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Endemic and Infectious Diseases Suez Canal University Ismailia 41522 Egypt. King Salman bin Abdulaziz medical City Madinah 42311 Saudi Arabia. Prince mohammed Bin Abdulaziz Hospital Madinah 41511 Saudi Arabia.

Background:Hepatocellular carcinoma (HCC) is the most common cause of cancer-related death in Saudi Arabia. Our study aimed to investigate the patterns of HCC and the effect of tNm staging, Alfa-fetoprotein (AFP), and Child-turcotte Pugh (CtP) on patients' overall survival (OS).methods:A retrospective analysis was conducted on 43 HCC patients at a single oncology center in Saudi Arabia from 2015 to 2020. All patients had to fulfill one of the following criteria: (a) a liver lesion reported as definitive HCC on dynamic imaging and/or (b) a biopsy-confirmed diagnosis.Results:the mean patient age of all HCC cases was 66.8 with a male-to-female ratio of 3.3:1. All patients were stratified into two groups: viral HCC (n = 22, 51%) and non-viral HCC (n = 21, 49%). Among viral-HCC patients, 55% were due to HBV and 45% due to HCV. Cirrhosis was diagnosed in 79% of cases. Age and sex did not significantly statistically differ in OS among viral and non-viral HCC patients (-value > 0.05). About 65% of patients had tumor size >5 cm during the diagnosis, with a significant statistical difference in OS (-value = 0.027). AFP was >400 ng/ml in 45% of the patients. there was a statistically significant difference in the OS in terms of AFP levels (-value = 0.021). A statistically significant difference was also observed between the CtP score and OS (-value = 0.02). CtP class B had the longest survival. BSC was the most common treatment provided to HCC patients followed by sorafenib therapy. there was a significant statistical difference in OS among viral and non-viral HCC patients (-value = 0.008).Conclusions:the most common predictors for OS were the underlying cause of HCC, AFP, and tumor size. Being having non-viral etiology, a tumor size >5 cm, an AFP > 400 ng/mL, and a CtP score class C were all negatively associated with OS.

关键词： Alpha-fetoprotein (AFP) Child-turcotte-pugh Hepatocellular carcinoma Pattern Progression free survival