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simulation of Compressible Two-Phase Flows Using a Void Ratio Transport Equation

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Communications in Computational Physics 2018年第6期24卷 167-203页

作者： Eric Goncalves Dia zeidan ENsMA Institut PprimeUPR 3346 CNRS86961 Futuroscope ChasseneuilFrance school of Basic sciences and Humanities German Jordanian UniversityAmmanJordan

A compressible and multiphase flows solver has been developed for the study of liquid/gas flows involving shock waves and strong expansion waves leading to *** solver has a structure similar to those of the one-fluid Euler solvers,differing from them by the presence of a void ratio *** model and the system of equations to be simulated are *** are displayed for shock and expansion tube problems,shock-bubble interaction and underwater *** agreement with reference solutions,obtained from explicit finite volume approaches,is *** numerical methods are additionally displayed to provide comparable and improved computational efficiency to the model and the system of *** overall procedure is therefore very well suited for use in general two-phase fluid flow simulations.

关键词： Compressible two-phase flows cavitation homogeneous model shock and expansion waves inviscid simulation

On the Computations of Gas-solid Mixture Two-Phase Flow

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Advances in Applied Mathematics and Mechanics 2014年第1期6卷 49-74页

作者： D.zeidan R.Touma Department of Mathematics Al-Balqa Applied UniversityAl-SaltJordan Department of Computer science&Mathematics Lebanese American UniversityBeirutLebanon

This paper presents high-resolution computations of a two-phase gas-solid mixture using a well-defined mathematical *** HLL Riemann solver is applied to solve the Riemann problem for the model *** solution is then employed in the construction of upwind Godunov methods to solve the general initial-boundary value problem for the two-phase gas-solid *** representative test cases have been carried out and numerical solutions are provided in comparison with existing numerical *** demonstrate the robustness,effectiveness and capability of these methods,the model results are compared with reference *** addition to that,these results are compared with the results of other simulations carried out for the same set of test cases using other numerical methods available in the *** diverse comparisons demonstrate that both the model equations and the numerical methods are clear in mathematical and physical concepts for two-phase fluid flow problems.

关键词： Hyperbolic conservative equations two-phase flows compressible gas-solid mixture conservation laws approximate Riemann solver upwind Godunov methods numerical simulation.

Modeling of climate change impacts on Lake Burullus, coastal lagoon(Egypt)

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International Journal of sediment Research 2021年第6期36卷 756-769页

作者： A.shalby M.Elshemy B.A.zeidan Faculty of Engineering Tanta University Faculty of Engineering Al-Baha University

Coastal lagoons are particularly vulnerable to climate change, in particular, sea Level Rise(sLR) due to their shallowness. Lake Burullus provides a variety of socio-economic services as the second largest coastal lagoon in Egypt. Recently, it has experienced significant ecological deterioration. Thus, its ecosystem is fragile in the face of anthropogenic induced changes. The main objective of the current study is to investigate the climate change impacts on characteristics of Lake Burullus. A depth averaged hydro-ecological modeling system, MIKE21, was applied to develop an eco-hydrodynamic model for the lake. The developed model was calibrated and verified for two successive years: July 2011 - June 2012 and July 2012 -J une 2013. The model simulations exhibited good agreement with the measurements during the calibration and verification processes. six different Regional Climate Models(RCMs) were compared,using six different statistical metrics, to determine the most accurate one for the study area. The required meteorological input, including surface air temperature, precipitation, and evaporation were derived from the selected RCM. The meteorological input was extracted for two different years in the 21century considering one Representative Concentration Pathways(RCPs) scenario, based on the Intergovernmental Panel on Climate Change(IPCC) 5 th Report. Regional sLR projections for the Mediterranean sea for the selected RCP scenario and the two studied years were obtained. These future climate change estimates were used to modify the validated model of the lake. A sensitivity analysis was applied to assess effect of future climatic conditions and sLR, separately. The results revealed that the lake water depths will increase and it will be warmer and more saline. significant spatial variability of the studied parameters under climate change forcing is expected. Consequently, climate change is going to restrict the lake’s ability to preserve the present-day species.

关键词： Climate change IPCC Lake Burullus MIKE 21 Nile Delta Water quality model

Update on acute myeloid leukemia stem cells:New discoveries and therapeutic opportunities

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World Journal of stem Cells 2016年第10期8卷 316-331页

作者： Maximilian stahl Tae Kon Kim Amer M zeidan section of Hematology Department of Internal MedicineYale School of Medicine

The existence of cancer stem cells has been wellestablished in acute myeloid leukemia. Initial proof of the existence of leukemia stem cells(LsCs) was accomplished by functional studies in xenograft models making use of the key features shared with normal hematopoietic stem cells(HsCs) such as the capacity of self-renewal and the ability to initiate and sustain growth of progenitors in vivo. significant progress has also been made in identifying the phenotype and signaling pathways specific for LsCs. Therapeutically, a multitude of drugs targeting LsCs are in different phases of preclinical and clinical development. This review focuses on recent discoveries which have advanced our understanding of LsC biology and provided rational targets for development of novel therapeutic agents. One of the major challenges is how to target the selfrenewal pathways of LsCs without affecting normal HsCs significantly therefore providing an acceptable therapeutic window. Important issues pertinent to the successful design and conduct of clinical trials evaluating drugs targeting LsCs will be discussed as well.

关键词： Leukemia stem cells Cancer stem cells Acute myeloid leukemia stem cell niche Xenotransplantation Plerixafor NF-κ B C-X-C chemokine receptor type 4

Latent Tuberculosis Infection among Household Contacts of Pulmonary Tuberculosis Cases in Central state, sudan: Prevalence and Associated Factors

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Journal of Tuberculosis Research 2017年第4期5卷 265-275页

作者： Abdulmannan Mohamed Aman zeidan Abdu zeidan Medical Centre of the Taibah University Medina Saudi Arabia Department of Family and Community Medicine Medical College Taibah University Medina Saudi Arabia

Introduction: Tuberculosis is a major health problem in developing countries including sudan. screening for TB cases through Household contacts (HHCs) investigation is an appropriate strategy to interrupt transmission of TB. Objectives: To determine the prevalence tuberculosis infection and risk factors for tuberculosis infection among household contacts in Wadimadani locality, Central state, sudan, between November 2015 and April 2016. Methods: An analytical cross-sectional study conducted. During study period, to confirm TB diagnosis, all suspect contacts were tested through sputum samples, tuberculin skin test or chest X-ray. structured questionnaire was used to collect socio-demographic and environmental factors. Results: One hundred forty six patients of smear-positive pulmonary tuberculosis were included in the study, 657 household contacts were identified and screened. Forty three new TB cases were detected from household contacts, yielding a prevalence of 6.5% (95% confidence interval = 0.05, 0.09) of latent tuberculosis infection (LTBI). Two factors were significantly associated with LTBI among HHCs: duration of contact with a TB patient ≤ 4 months (P = 0.03) and the educational status (P = 0.02). Conclusion: screening of HHCs of index case of TB will contribute in early detection and treatment of new cases, and considered as a forward step towards eliminating TB.

关键词： Tuberculosis Latent Tuberculosis Infection Household Close Contact Central state sudan Prevalence Risk Factors

Diabetes Risk Factor and Its Relationship to Increasing Coronavirus (COVID-19) Mortality Rate in United states in 2019-2022: An Epidemiological study

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Open Journal of Epidemiology 2023年第2期13卷 128-143页

作者： Henry zeidan Iman zeidan Laura scholer-Bland College of Graduate & Professional studies University of New England Portland USA McLaren Central Michigan Medical Center and Central Michigan University School of Medicine MT. Pleasant USA Georgia Institute of Technology Atlanta USA

As an effort to understand the effect of diabetes on the increasing rate of COVID-19 infection, we embarked upon a detailed statistical analysis of various datasets that include COVID-19 infection and mortality rate, diabetes and diseases that may contribute to the severity and risk factor of diabetes in individuals and this impact on COVID-19 and the mortality rate. These diseases include respiratory diseases, cardiovascular diseases, and obesity. Equally significant is the statistical analysis on ethnicity, age, and sex on COVID-19 infection as well as mortality rate. Their possible contributions to increasing the severity and risk factor of diabetes as a risk to mortality to individuals who have COVID-19. Objectives: The ultimate objectives of this investigation are as follow: 1) Is there a risk factor of diabetes on COVID-19 infection and increasing mortality rate? 2) To what extent do other disease conditions that include, obesity, heart failure, and respiratory diseases influence the severity and risk factor of diabetes on increasing COVID-19 infection and mortality rate? 3) To what extent does age, race, and gender increase the mortality of COVID-19 and increase the severity and risk factor of diabetes on COVID-19 mortality rate? 4) How and why COVID-19 virus increases the risk of diabetes in children? 5) Diabetes and COVID-19: Who is most at Risk? Lastly, understanding the misconception of COVID-19 and diabetes.

关键词： Middle East Respiratory syndrome Coronavirus (MERs-COVID) Infection Risk Factors Omicron Virus COVID-19 Risk on Children Interactions of Independent Variables Poisson Regression Linear Regression

stem cells in gastrointestinal cancers: The road less travelled

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World Journal of stem Cells 2014年第5期6卷 606-613页

作者： sameh Mikhail Amer zeidan the Ohio state University Comprehensive Cancer Center James Cancer Hospital and Solove Research InstituteColumbusOH 43210 United States Yale Comprehensive Cancer Center Section of Hematology Department of Internal Medicine Yale UniversityNew Haven CT 06520-8028 United States

Cancer stem cells(CsC) are thought to be malignant cells that have the capacity to initiate and maintain tumor growth and survival. studies have described CsC in various gastrointestinal neoplasms such as colon, pancreas and liver and gastroesophageal tumors. The mechanism by which CsC develop remains unclear. several studies have explored the role of dysregulation of the Wnt/β-catenin, transformation growth factor-beta and hedhog pathways in generation of CsC. In this review, we discuss the various molecular abnormalities that may be related to formation of CsC in gastrointestinal malignancies, strategies to identify CsC and therapeutic strategies that are based on these concepts. Identification and targeting CsC is an intriguing area and may provide a new therapeutic option for patients with cancer including gastrointestinal malignancies. Although great progress has been made, many issues need to be addressed. Precise targeting of CsC will require precise isolation and characterization of those cells. This field is also evolving but further research is needed to identify markers that are specific for *** the application of this field has not entered the clinic yet, there continues to be significant optimism about its potential utility in overcoming cancer resistance and curing patients with cancer.

关键词： Cancer stem cells CD133+ WNT/β -catenin Transformation growth factor-beta Hedgehog Notch

Computing the Pressure Drop of Nanofluid Turbulent Flows in a Pipe Using an Artificial Neural Network Model

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Open Journal of Fluid Dynamics 2012年第4期2卷 130-136页

作者： Mahmoud s. Youssef Ayman A. Aly El-shafei B. zeidan Department of Mechanical Engineering Faculty of Engineering Taif University Al-Hawiah Saudi Arabia Mechanical Engineering Department Faculty of Engineering Assiut University Assiut Egypt Mechanical Power Engineering Department Faculty of Engineering Mansoura University Mansoura Egypt

In this study, an Artificial Neural Network (ANN) model to predict the pressure drop of turbulent flow of titanium dioxide-water (TiO2-water) is presented. Experimental measurements of TiO2-water under fully developed turbulent flow regime in pipe with different particle volumetric concentrations, nanoparticle diameters, nanofluid temperatures and Reynolds numbers have been used to construct the proposed ANN model. The ANN model was then tested by comparing the predicted results with the measured values at different experimental conditions. The predicted values of pressure drop agreed almost completely with the measured values.

关键词： Artificial Neural Networks (ANNs) Turbulent Flow Nanofluids Pressure Drop

An Antilock-Braking systems (ABs) Control: A Technical Review

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Intelligent Control and Automation 2011年第3期2卷 186-195页

作者： Ayman A. Aly El-shafei zeidan Ahmed Hamed Farhan salem 不详

Many different control methods for ABs systems have been developed. These methods differ in their theoretical basis and performance under the changes of road conditions. The present review is a part of research project entitled “Intelligent Antilock Brake system Design for Road-surfaces of saudi Arabia” In the present paper we review the methods used in the design of ABs systems. We highlight the main difficulties and summarize the more recent developments in their control techniques. Intelligent control systems like fuzzy control can be used in ABs control to emulate the qualitative aspects of human knowledge with several advantages such as robustness, universal approximation theorem and rule-based algorithms.

关键词： ABs Intelligent Control Fuzzy Control