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Thermal buckling analysis of ceramic-metal functionally graded plates

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Natural Science 2010年第9期2卷 968-978页

作者： Ashraf M. Zenkour daoud S. Mashat 不详

Thermal buckling response of functionally graded plates is presented in this paper using sinusoidal shear deformation plate theory (SPT). The material properties of the plate are assumed to vary according to a power law form in the thickness direction. Equilibrium and stability equations are derived based on the SPT. The non-linear governing equations are solved for plates subjected to simply supported boundary conditions. The buckling analysis of a functionally graded plate under various types of thermal loads is carried out. The influences of many plate parameters on buckling temperature difference will be investigated. Numerical results are presented for the SPT, demonstrating its importance and accuracy in comparison to other theories.

关键词： Thermal Buckling Non-Linear Strains Functionally Graded Material Sinusoidal Plate

Stress Function of a Rotating Variable-Thickness Annular Disk Using Exact and Numerical Methods

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Engineering（科研） 2011年第4期3卷 422-430页

作者： Ashraf M. Zenkour daoud S. Mashat 不详

In this paper, the exact analytical and numerical solutions for rotating variable-thickness annular disk are presented. The inner and outer edges of the rotating variable-thickness annular disk are considered to have free boundary conditions. Two different annular disks for the radially varying thickness are given. The numerical Runge-Kutta solution as well as the exact analytical solution is available for the first disk while the exact analytical solution is not available for the second annular disk. Both exact and numerical results for stress function, stresses, strains and radial displacement will be investigated for the first annular disk of variable thickness. The accuracy of the present numerical solution is discussed and its ability of use for the second rotating variable-thickness annular disk is investigated. Finally, the distributions of stress function, displacement, strains, and stresses will be presented. The appropriate comparisons and discussions are made at the same angular velocity.

关键词： Rotating Annular Disk Variable Thickness Runge-Kutta Method

Analytical and Numerical Solutions for a Rotating Annular Disk of Variable Thickness

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Applied Mathematics 2010年第5期1卷 430-437页

作者： Ashraf M. Zenkour daoud S. Mashat 不详

In this paper, the analytical and numerical solutions for rotating variable-thickness solid disk and numerical solution for rotating variable-thickness annular disk are presented. The outer edge of the solid disk and the inner and outer edges of the annular disk are considered to have clamped boundary conditions. Two different cases for the radially varying thickness of the solid and annular disks are given. The numerical solution as well as the analytical solution is available for the first case of the solid disk while the analytical solution is not available for the second case of the annular disk. Both analytical and numerical results for displacement and stresses will be investigated for the first case of radially varying thickness. The accuracy of the present numerical solution is discussed and its ability of use for the second case of radially varying thickness is investigated. Finally, the distributions of displacement and stresses will be presented and the appropriate comparisons and discussions are made at the same angular velocity.

关键词： Rotating Annular Disk Solid Disk Finite Difference Method

Pancreatic acinar cell carcinoma:A comprehensive review

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World Journal of Gastroenterology 2022年第40期28卷 5827-5844页

作者： Luis Fernando Calimano-Ramirez Taher daoud Dheeraj Reddy Gopireddy Ajaykumar C Morani Rebecca Waters Kazim Gumus Albert Russell Klekers Priya R Bhosale Mayur K Virarkar Department of Radiology University of Florida College of Medicine JacksonvilleJacksonvilleFL 32209United States Department of Diagnostic Radiology The University of Texas MD Anderson Cancer CenterHoustonTX 77030United States Department of Diagnostic Radiology University of Florida College of Medicine JacksonvilleJacksonvilleFL 32209United States Department of Pathology and Lab Medicine The University of Texas MD Anderson Cancer CenterHoustonTX 77030United States Department of Research and Diagnostic Radiology University of Florida College of Medicine JacksonvilleJacksonvilleFL 32209United States

Acinar cell carcinoma(ACC)is a rare pancreatic malignancy with distinctive clinical,molecular,and morphological *** long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma *** there are no significant patient series about ACCs,our understanding of this illness is mainly based on case reports and limited patient *** resection is the treatment of choice for patients with the disease restricted to one organ;however,with recent breakthroughs in precision medicine,medicines targeting the one-of-a-kind molecular profile of ACC are on the *** are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not *** a result of shared genetic alterations,ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal *** role of neoadjuvant or adjuvant chemoradiotherapy has not been *** article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

关键词： Acinar cell carcinoma Pancreas Imaging Immunohistochemical stains Molecular features Surgery Chemotherapy

Multi-Team Bertrand Game with Heterogeneous Players

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Applied Mathematics 2011年第9期2卷 1182-1190页

作者： Mohammed Fathy Elettreby daoud Suleiman Mashat Ashraf Mobarez Zenkour 不详

In this paper, we proposed a general form of a multi-team Bertrand game. Then, we studied a two-team Bertrand game, each team consists of two firms, with heterogeneous strategies among teams and homogeneous strategies among players. We find the equilibrium solutions and the conditions of their local stability. Numerical simulations were used to illustrate the complex behaviour of the proposed model, such as period doubling bifurcation and chaos. Finally, we used the feedback control method to control the model.

关键词： Bertrand Game Non-convex Dynamical Multi-team Game Incomplete Information Dynamical System Marginal Profit Method Nash Equilibrium

Power Conversion Enhancement of CdS/CdTe Solar Cell Interconnected with Tunnel Diode

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Circuits and Systems 2012年第3期3卷 230-237页

作者： Wagah F. Mohammed Omar daoud Munther Al-Tikriti Communications and Electronics Department Faculty of Engineering Philadelphia University Amman Jordan

One of the most promising solar cell devices is cadmium telluride (CdTe) based. These cells however, have their own problems of stability and degradation in efficiency. Measurements show that CdS/CdTe solar cell has high series resistance which degrades the performance of solar cell energy conversion. Both active layers (CdS and CdTe) had been fabricated by thermal evaporation and tested individually. It was found that CdS window layer of 300 nm have the lowest series resistance with maximum light absorption. While 5 - 7 μm CdTe absorber layer absorbed more than 90% of the incident light with minimum series resistance. A complete CdS/CdTe solar cell was fabricated and tested. It was found that deposited cell without heat treatment shows that the short circuit current increment decreases as the light intensity increases. This type of deposited cell has low conversion efficiency. The energy conversion efficiency was improved by heat treatment, depositing heavily doped layer at the back of the cell and minimizing the contact resistivity by depositing material with resistivity less than 1 m??cm2. All these modifications were not enough because the back contact is non-ohmic. Tunnel diode of CdTe (p++)/CdS (n++) was deposited in the back of the cell. The energy conversion efficiency was improved by more than 7%.

关键词： CdS/CdTe Solar Cells Energy Conversion Efficiency

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七周七Web开发框架

Reliable Train Network with Active Supervisor

作者： (美)Jack Moffitt (美)Fred daoud

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Journal of Transportation Technologies 2013年第3期3卷 214-219页

作者： Mai Hassan Ramez M. daoud Hassanein H. Amer Electronics Engineering Department American University in Cairo Cairo Egypt

In this paper, a new reliable hierarchical model is suggested for a two-wagon train Networked Control System. Each wagon has a Controller that carries the control load and an Entertainment server that handles the entertainment. A supervisory controller runs on top of the two controllers and the two entertainment servers. Contrary to a similar model in the literature, the Supervisory node replaces a Controller as soon as it fails (Active Supervisor). All system states are analyzed and simulated using OPNET. It is shown that, for all states, this architecture has zero control packets dropped and the end-to-end delay is below the maximum target delay. A comparison between this Active model and the other model in the literature is presented. It is found that the entertainment in this new architecture is kept available for the passengers in more of the system states when compared to the architecture previously presented in the literature.

关键词： Ethernet Train Networked Control Systems Active Supervisor Hierarchical Architecture

Coronavirus disease 2019 and renal transplantation

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World Journal of Clinical Cases 2021年第27期9卷 7986-7997页

作者： Mahmoud Nassar Nso Nso Jonathan Ariyaratnam Jasmine Sandhu Mahmoud Mohamed Bahaaeldin Baraka Atif Ibrahim Mostafa Alfishawy David Zheng Harangad Bhangoo Karim M Soliman Matthew Li Vincent Rizzo Ahmed daoud Department of Medicine Icahn School of Medicine at Mount Sinai(NYC Health and Hospitals:Queens)New YorkNY 10029United States Department of Medicine University of Tennessee Health Science CenterMemphisTN 38163United States Department of Oncology Southend University HospitalNHS Foundation TrustEssex SS00RYUnited Kingdom Renal Division Department of MedicineUniversity of Tennessee Health Science CenterMemphisTN 38163United States Infectious Diseases Infectious Diseases Consultants and Academic Researchers of Egypt IDCARECairo 0000Egypt Department of Medicine Medical University of South CarolinaCharlestonSC 29425United States Department of Clinical Pharmacy Icahn School of Medicine at Mount Sinai(NYC Health and Hospitals:Queens)New YorkNY 10029United States Department of Medicine Icahn School of Medicine at Mount Sinai(NYC Health and Hospitals:Queens)New YorkNY 11373United States Department of Medicine Kasr Alainy Medical SchoolCairo UniversityCairo 11562Egypt

Ever since the severe acute respiratory syndrome virus causing coronavirus disease 2019(COVID-19)struck the world,global health strategies have changed *** to the Centers for Disease Control and Prevention,kidney transplant recipients are stratified as being high risk of developing fatal illness from COVID-19 *** transplant is the gold-standard treatment for end-stage kidney disease *** the pandemic,significant concerns have emerged regarding continuation of kidney transplant surgeries and management of kidney transplant recipients *** added risk of immunosuppression in this cohort was and remains a theoretical concern,posing a potential risk of transplantation rather than *** comprehensive review aims to cover most of the faced challenges in kidney transplantation in different stages of the *** addition,it will elucidate the epidemiology,nature,course of the disease,surgical consideration in donors and recipients as well as role of immunosuppression and management of COVID-19 infected kidney transplant recipients during these extraordinary circumstances.

关键词： Renal transplantation COVID-19 SARS-CoV-2 Kidney failure