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Numerical studies for solving fractional integro-differential equations

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Journal of Ocean Engineering and science 2018年第2期3卷 127-132页

作者： a.m.s.mahdy Department of mathematics Faculty of ScienceZagazig UniversityZagazigEgypt Department of mathematics Faculty of ScienceTaif UniversitySaudi Arabia

In this paper,we give a new numerical method for solving a linear system of fractional integro-differential *** fractional derivative is considered in the Caputo *** proposed method is least squares method aid of Hermite *** suggested method reduces this type of systems to the solution of systems of linear algebraic *** demonstrate the accuracy and applicability of the presented method some test examples are *** results show that this approach is easy to implement and accurate when applied to integro-differential *** show that the solutions approach to classical solutions as the order of the fractional derivatives approach.

关键词： Least squares method Caputo fractional Hermite polynomials Linear fractional integro-differential equations

solving Fractional Integro-Differential Equations by Using sumudu Transform method and Hermite spectral Collocation method

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Computers, materials & Continua 2018年第2期54卷 161-180页

作者： Y.A.Amer a.m.s.mahdy E.s.m.Youssef Department of mathematics Faculty of Science44519Zagazig UniversityEgypt Department of mathematics and statistics Faculty of ScienceTaif UniversitySaudi Arabia

In this paper we are looking forward to finding the approximate analytical solutions for fractional integro-differential equations by using sumudu transform method and Hermite spectral collocation *** fractional derivatives are described in the Caputo *** applications related to sumudu transform method and Hermite spectral collocation method have been developed for differential equations to the extent of access to approximate analytical solutions of fractional integro-differential equations.

关键词： Caputo derivative integro-differential equations hermite polynomials sumudu transform

Reduced Differential Transform method for solving Nonlinear Biomathematics models

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Computers, materials & Continua 2019年第9期61卷 979-994页

作者： K.A.Gepreel a.m.s.mahdy m.s.mohamed A.Al-Amiri Department of mathematics Faculty of ScienceTaif UniversityTaif26571Saudi Arabia Department of mathematics Faculty of ScienceZagazig UniversityZagazig44519Egypt Department of mathematics Faculty of ScienceAl-Azher UniversityNasr CityCairo11884Egypt Department of mathematics Faculty of ScienceBisha UniversityBisha61922Saudi Arabia

In this paper,we study the approximate solutions for some of nonlinear Biomathematics models via the e-epidemic sI1I2R model characterizing the spread of viruses in a computer network and sIR childhood disease *** reduced differential transforms method(RDTm)is one of the interesting methods for finding the approximate solutions for nonlinear *** apply the RDTm to discuss the analytic approximate solutions to the sI1I2R model for the spread of virus HCV-subtype and sIR childhood disease *** discuss the numerical results at some special values of parameters in the approximate *** use the computer software package such as mathematical to find more iteration when calculating the approximate *** results and discussed quantitatively are presented to illustrate behavior of the obtained approximate solutions.

关键词： Reduced differential transforms method nonlinear biomathematics models sI1I2R model sIR model analytic approximate solutions qualitative analysis stability and equilibrium.

Reduced differential transform and sumudu transform methods for solving fractional financial models of awareness

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Applied mathematics(A Journal of Chinese Universities) 2023年第3期38卷 338-356页

作者： a.m.s.mahdy K.A.Gepreel Kh.Lotfy A.El-Bary Department of mathematics and statistics College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt Arab Academy for science Technology and Maritime Transport1029AlexandriaEgypt

In that paper,we new study has been carried out on previous studies of one of the most important mathematical models that describe the global economic movement,and that is described as a non-linear fractional financial model of awareness,where the studies are represented at the steps following:One:The schematic of the model is ***:The disease-free equilibrium point(DFE)and the stability of the equilibrium point are ***:The stability of the model is fulfilled by drawing the Lyapunov exponents and Poincare ***:The existence of uniformly stable solutions have ***:The Caputo is described as the fractional ***:Fractional optimal control for NFFmA is discussed by clarifying the fractional optimal control through drawing before and after ***:Reduced differential transform method(RDTm)and sumudu Decomposition method(sDm)are used to take the resolution of an ***,we display that sDm and RDTm are highly identical.

关键词： financial of awareness stability Lyapunov exponents Poincare map fractional optimal control Hamiltonian

High-Order spatial FDTD solver of maxwell’s Equations for Terahertz Radiation Production

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Journal of Applied mathematics and Physics 2024年第4期12卷 1028-1042页

作者： Abdelrahman mahdy Department of Physical sciences College of Science Jazan University Jazan Kingdom of Saudi Arabia

We applied a spatial high-order finite-difference-time-domain (HO-FDTD) scheme to solve 2D maxwell’s equations in order to develop a fluid model employed to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma. We examined the performance of the applied scheme, in this context, we implemented the developed model to study selected phenomena in terahertz radiation production, such as the excitation energy and conversion efficiency of the produced THz radiation, in addition to the influence of the pulse chirping on properties of the produced radiation. The obtained numerical results have clarified that the applied HO-FDTD scheme is precisely accurate to solve maxwell’s equations and sufficiently valid to study the production of terahertz radiation by the filamentation of two femtosecond lasers in air plasma.

关键词： The Finite-Difference-Time-Domain Terahertz Radiation Production Filamentation of Femtosecond Laser maxwell’s Equations solution

Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) compositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： s.m.Yakout A.m.Youssef Inorganic Chemistry Department National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recombination of the photoexcited charge carriers(electrons-holes pairs) are of paramount *** the current study, we report the photocatalytic characteristics of four compositions composed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harmful dyes(Congo red and methylene blue). The X-ray diffraction technique verified the configuration of mixed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dimensions of the unit cell volume of TiO_(2)confirm the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Remarkable widening of wavelengths absorption with formation of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)samples exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on sEm images, incorporation of Cu^(2+)and La^(3+)ions influences the surface morphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation compared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm CR dye in 20 min as well as above average photocatalytic efficiency of 63% for 30 ppm CR dye in 120 min. As well, it showed acceptable photodegradation activity of 52% for 30 ppm mB solution in 140 min of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in terms of higher ch

关键词： semiconductor TiO_(2) Rare earths Congo red methylene blue solar spectrum Photodegradation

Advancing Early Detection of Colorectal Adenomatous Polyps via Genetic Data Analysis: A Hybrid machine Learning Approach

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Journal of Computer and Communications 2024年第7期12卷 23-38页

作者： Ahmed s. maklad mohamed A. mahdy Amer malki Noboru Niki Abdallah A. mohamed Computer science Department College of Computer Science and Engineering in Yanbu Taibah University Medina Saudi Arabia Information systems Department Faculty of Computers and Artificial Intelligence Beni-Suef University Beni-Suif Egypt Computer science Department Faculty of Computers and Artificial Intelligence Beni-Suef University Beni-Suif Egypt Institute of Advanced science and Technology Tokushima University Tokushima Japan Information systems Department College of Computer Science and Engineering in Yanbu Taibah University Medina Saudi Arabia mathematics and Computer science Department Faculty of Science Menoufia University Menoufia Egypt

In this study, a hybrid machine learning (HmL)-based approach, incorporating Genetic data analysis (GDA), is proposed to accurately identify the presence of adenomatous colorectal polyps (ACRP) which is a crucial early detector of colorectal cancer (CRC). The present study develops a classification ensemble model based on tuned hyperparameters. surpassing accuracy percentages of early detection approaches used in previous studies, the current method exhibits exceptional performance in identifying ACRP and diagnosing CRC, overcoming limitations of CRC traditional methods that are based on error-prone manual examination. Particularly, the method demonstrates the following CRP identification accuracy data: 97.7 ± 1.1, precision: 94.3 ± 5, recall: 96.0 ± 3, F1-score: 95.7 ± 4, specificity: 97.3 ± 1.2, average AUC: 0.97.3 ± 0.02, and average p-value: 0.0425 ± 0.07. The findings underscore the potential of this method for early detection of ACRP as well as clinical use in the development of CRC treatment planning strategies. The advantages of this approach are highly expected to contribute to the prevention and reduction of CRC mortality.

关键词： Colorectal Adenoma Detection Colorectal Cancer Diagnosis Hybrid machine Learning Genetics Analysis

^(4)He monolayer on graphene:a quantum monte Carlo study

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Communications in Theoretical Physics 2024年第9期76卷 149-157页

作者： s Yu m Boninsegni Department of Physics University of AlbertaEdmontonAlbertaT6G 2H5Canada

We revisit the problem of adsorption of a single^(4)He layer on graphene,focusing on the commensurate(C_(1/3))crystalline phase,specifically on whether it may possess a nonzero superfluid response,and on the existence of superfluid phases,either(metastable)liquid or vacancy-doped *** make use of canonical quantum monte Carlo simulations at zero and finite temperature,based on a realistic microscopic model of the *** results confirm the absence of any superfluid response in the commensurate crystal,and that no thermodynamically stable uniform phase exists at lower *** evidence of a possibly long-lived,metastable superfluid phase at C_(1/3)coverage is ***,the results of ground-state projection methods and finite-temperature simulations are entirely consistent.

关键词： superfluidity low-dimensional systems quantum monte Carlo helium supersolids

Direct microwave leaching conditions of rare earth elements in fluorescent wastes

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Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol m.N.saridede s.s.Kaplan m.s.sonmez Department of metallurgical and materials Engineering Yildiz Technical UniversityIstanbulTurkey Department of Chemical Engineering and materials science Stevens Institute of TechnologyNew JereyUSA Department of metallurgical and materials Engineering Istanbul Technical UniversityIstanbulTurkey

The luminescent phosphor powder in the fluorescent lamp constitutes 2%of the lamp’s *** can be mentioned that fluorescent wastes are a crucial raw material to produce rare earth *** the present study,microwave leaching process was conducted to dissolve rare earth elements yttrium(Y),europium(Eu),and remaining rare earth elements(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the microwave leaching process,the effects of the temperature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HNO_(3)),sulphuric acid(H_(2)sO_(4))),acid concentration(0.5-6 mol/L),solid to liquid ratio(0.1:10-0.5:10)and reaction time(5-90 min)parameters on leaching efficiencies of varying rare earth elements and calcium were *** highest yield was obtained in the direct microwave leaching of fluorescent waste with the experimental conditions of 6 mol/L HCl,160℃,0.1:10 solid-to-liquid ratio(s:L),and 90 *** energy calculations were made,and kinetic models of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum(La),cerium(Ce),and terbium(Tb)were examined to be chemical reaction ***,calcium(Ca)and gadolinium(Gd)seem coherent with the mixed ***,mathematical models of all experimental studies are created with the response surface Box-Behnken method and the correlation coefficients of all the models are over 90%.

关键词： Rare earth elements(REEs) Direct microwave leaching Fluorescent waste Kinetic models Response surface method