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Applied mathematics and mechanics(English Edition) 2005年第4期26卷 470-475页

作者： hamdy m.youssef mathematical Department Faculty of Engineering Umm Al_Qura UniversityMakkah Al_Mokaramah P.5555 Saudi Arabia

The equations of generalized thermoelasticity with one relaxation time with variable modulus of elasticity and the thermal conductivity were used to solve a problem of an infinite material with a spherical *** inner surface of the cavity was taken to be traction free and acted upon by a thermal shock to the surface. Laplace transforms techniques were used to obtain the solution by a direct *** inverse Laplace transforms was obtained *** temperature,displacement and stress distributions are represented graphically.

关键词： thermoelasticity generalized thermoelasticity modulus of elasticity thermal conductivity

State-space approach to vibration of gold nano-beam induced by ramp type heating

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Nano-micro Letters 2010年第3期2卷 139-147页

作者： hamdy m.youssef Khaled A.Elsibai mathematical Department-Faculty of Education-Alexandria University-Egypt mathematics Department Faculty of ScienceMansoura University

In the nanoscale beam,two effects become *** is the non-Fourier effect in heat conduction and the other is the coupling effect between temperature and strain *** the present study,a generalized solution for the generalized thermoelastic vibration of gold nano-beam resonator induced by ramp type heating is *** solution takes into account the above two ***-space and Laplace transform methods are used to determine the lateral vibration,the temperature,the displacement,the stress and the strain energy of the *** effects of the relaxation time and the ramping time parameters have been studied.

关键词： Thermoelasticity Euler-Bernoulli equation Gold nano-beam Ramp type heating

On the Application of the Adomian’s Decomposition method to a Generalized Thermoelastic Infinite medium with a Spherical Cavity in the Framework Three Different models

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Fluid Dynamics & materials Processing 2019年第5期15卷 597-611页

作者： Najat A.Alghamdi hamdy m.youssef mathematics Department Faculty of ScienceUmm Al-Qura UniversityMakkahSaudi Arabia mathematics Department Faculty of EducationAlexandria UniversityAlexandriaEgypt mathematics Department Faculty of EngineeringUmm Al-Qura UniversityMakkahSaudi Arabia

A mathematical model is elaborated for a thermoelastic infinite body with a spherical cavity.A generalized set of governing equations is formulated in the context of three different models of thermoelasticity:the Biot model,also known as“coupled thermoelasticity”model;the Lord-Shulman model,also referred to as“generalized thermoelasticity with one-relaxation time”approach;and the Green-Lindsay model,also called“generalized thermoelasticity with two-relaxation times”*** Adomian’s decomposition method is used to solve the related mathematical *** bounding plane of the cavity is subjected to harmonic thermal loading with zero heat flux and *** results for the temperature,radial stress,strain,and displacement are represented *** is shown that the angular thermal load and the relaxation times have significant effects on all the studied fields.

关键词： Adomian’s decomposition method generalized thermoelasticity relaxation time iteration method

带球形空腔的广义热弹性无限大材料的弹性模量和传热系数与材料参考温度的相关性

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应用数学和力学 2005年第4期26卷 431-436页

作者： H.m.约塞夫吴承平约姆.阿-夸热大学工程学院数学系

　利用具某一松弛时间的广义热弹性方程求解了带球形空腔的无限大材料问题·　该材料的弹性模量和传热系数是可变的·　空腔的内表面没有力作用,但有热冲击作用·　利用Laplace变换求得直接逼近解·　数值求解了Laplace逆变换·　给出... 详细信息

　利用具某一松弛时间的广义热弹性方程求解了带球形空腔的无限大材料问题·　该材料的弹性模量和传热系数是可变的·　空腔的内表面没有力作用,但有热冲击作用·　利用Laplace变换求得直接逼近解·　数值求解了Laplace逆变换·　给出了温度。

关键词：热弹性材料广义热弹性材料弹性模量传热系数

Partially Deep-Learning Encryption Technique

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Computers, materials & Continua 2023年第2期74卷 4277-4291页

作者： hamdy m.mousa Faculty of Computers and Information Menoufia UniversityMenoufia32511Egypt

The biggest problem facing the world is information security in the digital *** protection and integrity are hot topics at all times,so many techniques have been introduced to transmit and store data *** increase in computing power is increasing the number of security breaches and attacks at a higher rate than before on ***,a number of existing security systems are at risk of *** paper proposes an encryption technique called Partial Deep-Learning Encryption Technique(PD-LET)to achieve data ***-LET includes several stages for encoding and decoding digital *** preprocessing,convolution layer of standard deep learning algorithm,zigzag transformation,image partitioning,and encryption key are the main stages of ***,the proposed technique converts digital data into the corresponding matrix and then applies encryption stages to *** implementation of encrypting stages is frequently *** collaboration between deep learning and zigzag transformation techniques provides the best output result and transfers the original data into a completely undefined image which makes the proposed technique efficient and secure via data ***,its implementation phases are continuously changed during the encryption phase,which makes the data encryption technique more immune to some future attacks because breaking this technique needs to know all the information about the encryption *** security analysis of the obtained results shows that it is computationally impractical to break the proposed technique due to the large size and diversity of keys and PD-LET has achieved a reliable security system.

关键词： Encryption technique deep learning security zigzag transformation image partitioning

On null Controllability of fractional stochastic differential system with fractional Brownian motion

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Journal of Control and Decision 2021年第1期8卷 50-63页

作者： hamdy m.Ahmed Higher Institute of Engineering El-Shorouk AcademyEl-Shorouk CityCairoEgypt

In this paper,we are dealing with the null controllability of fractional stochastic differential system with fractional Brownian *** null controllability for Sobolev-type Hilfer fractional stochastic differential system with fractional Brownian motion of Clarke’s subdifferential type is *** sufficient conditions for null controllability of fractional stochastic differential system with fractional Brownian motion and control on the boundary are ***,an example is given to illustrate the obtained results.

关键词： Fractional Brownian motion Clarke subdifferential fractional stochastic differential system null controllability

Hilfer fractional neutral stochastic partial differential equations with delay driven by Rosenblatt process

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Journal of Control and Decision 2022年第2期9卷 226-243页

作者： hamdy m.Ahmed Higher Institute of Engineering El-Shorouk AcademyEI-Shorouk CityCairoEgypt

This manuscript is mainly focusing on the approximate controllability and the null controllability for fractional neutral stochastic partial differential equations with delay driven by Rosenblatt *** discuss the sufficient conditions for approximate controllability and null controllability for Hilfer fractional neutral stochastic partial differential equations driven by Rosenblatt ***,we provide two examples to verify the obtained results.

关键词： Hilfer fractional neutral stochastic integro-differential systems approximate controllability null controllability Rosenblatt process

Study on the SEIQR model and applying the epidemiological rates of COVID-19 epidemic spread in Saudi Arabia

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Infectious Disease modelling 2021年第1期6卷 678-692页

作者： hamdy youssef Najat Alghamdi magdy A.Ezzat Alaa A.El-Bary Ahmed m.Shawky mechanical Engineering Department College of Engineering and Islamic ArchitectureUmm Al-Qura UniversityMakkahSaudi Arabia Department of mathematics Faculty of Applied ScienceUmm Al-Qura UniversityMakkahSaudi Arabia College of Science and Arts Qassim UniversityAl BukairiyahAl QassimSaudi Arabia Arab Academy for Science Technology and Maritime TransportP.O.Box 1029AlexandriaEgypt Science and Technology Unit(STU) Umm Al-Qura UniversityMakkahSaudi Arabia National Committee for mathematics Academy of Scientific Research and TechnologyEgypt

This article attempts to establish a mathematical epidemic model for the outbreak of the new COVID-19 coronavirus.A new consideration for evaluating and controlling the COVID-19 outbreak will be constructed based on the SEIQR Pandemic *** this paper,the real data of COVID-19 spread in Saudi Arabia has been used for the mathematical model and dynamic *** the new reproductive number and detailed stability analysis,the dynamics of the proposed SEIQR model have been *** local sensitivity of the reproduction number has been *** domain of solution and equilibrium based on the SEIQR model have been proved using a Jacobian linearization *** state of equilibrium and its significance have been proved,and a study of the integrity of the disease-free equilibrium has been carried *** Lyapunov stability theorem demonstrated the global stability of the current model *** SEIQR model has been numerically validated and projected by contrasting the results from the SEIQR model with the actual COVID-19 spread data in Saudi *** result of this paper shows that the SEIQR model is a model that is effective in analyzing epidemic spread,such as *** the end of the study,we have implemented the protocol which helped the Saudi population to stop the spread of COVID-19 rapidly.

关键词： COVID-19 Jacobian matrix Lyapunov stability Reproduction number SEIR model SEIQR model

Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction:Impact on in-hospital arrhythmia

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World Journal of Cardiology 2023年第3期15卷 106-115页

作者： mohamed Aboel-Kassem F Abdelmegid mohamed m Bakr hamdy Shams-Eddin Amr A youssef Ahmed Abdel-Galeel Department of Cardiovascular medicine Assiut University Heart HospitalAssiut UniversityAssiut 71526Egypt Department of Cardiology Sohag Heart and GIT CenterSohag 85264Egypt Department of Cardiology Assiut Police HospitalAssiut 71526Egypt Department of Cardiology Qena General HospitalQena 92354Egypt

BACKGROUND myocardial ischemia and ST-elevation myocardial infarction(STEmI)increase QT dispersion(QTD)and corrected QT dispersion(QTcD),and are also associated with ventricular *** To evaluate the effects of reperfusion strategy[primary percutaneous coronary intervention(PPCI)or fibrinolytic therapy]on QTD and QTcD in STEmI patients and assess the impact of the chosen strategy on the occurrence of in-hospital *** This prospective,observational,multicenter study included 240 patients admitted with STEmI who were treated with either PPCI(group I)or fibrinolytic therapy(group II).QTD and QTcD were measured on admission and 24 hr after reperfusion,and patients were observed to detect in-hospital *** There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II *** and QTcD were found to be shorter in group I patients at 24 hr than those in group II(53±19 msec vs 60±18 msec,P=0.005 and 60±21 msec vs 69+22 msec,P=0.003,respectively).The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I(25 patients,20.8%vs 8 patients,6.7%,P=0.001).Furthermore,QTD and QTcD were higher in patients with in-hospital arrhythmia than those without(P=0.001 and P=0.02,respectively).CONCLUSION In STEmI patients,PPCI and fibrinolytic therapy effectively reduced QTD and QTcD,with a higher observed reduction using *** was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic *** addition,QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

关键词： Arrhythmia QT dispersion ST-segment elevation myocardial infarction Reperfusion Primary percutaneous coronary intervention Fibrinolytic therapy

Interstitial cells of Cajal, the maestro in health and disease

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World Journal of Gastroenterology 2010年第26期16卷 3239-3248页

作者： Randa m mostafa Yasser m moustafa Hosam hamdy Department of Basic medical Sciences College of Medicine Sharjah University Sharjah 27272 United Arab Emirates Department of Pharmacology and Toxicology College of Pharmacy Suez Canal University Ismaelia 24421 Egypt Department of Surgery Vice Chancellor of Medical and Health sciences Colleges Sharjah University Sharjah 27272 United Arab Emirates

Interstitial cells of Cajal (ICC) are important players in the symphony of gut motility. They have a very signif icant physiological role orchestrating the normal peristaltic activity of the digestive system. They are the pacemaker cells in gastrointestinal (GI) muscles. Absence, reduction in number or altered integrity of the ICC network may have a dramatic effect on GI system motility. more understanding of ICC physiology will foster advances in physiology of gut motility which will help in a future breakthrough in the pharmacological interventions to restore normal motor function of GI tract. This mini review describes what is known about the physiologic function and role of ICCs in GI system motility and in a variety of GI system motility disorders.

关键词： Interstitial cells of Cajal Gastrointestinal motility Peristalsis