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High-response n-butanol gas sensor based on ZnO/In_(2)O_(3) heterostructure

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Rare metals 2023年第1期42卷 198-209页

作者： Zhen-Yu Yuan Fan Yang Hong-min Zhu Fan-Li meng medhat Ibrahim College of Information Science and Engineering Northeastern UniversityShenyang110819China Spectroscopy department National Research CentreGiza12622Egypt

In this study,ZnO/In_(2)O_(3)-heterostructured nanosheets were prepared using a one-step hydrothermal *** effects of ZnO content on the gas-sensing performance were discussed,with ZnO/In_(2)O_(3)-2 exhibiting the highest performance among the prepared *** response of ZnO/In_(2)O_(3)-2 to n-butanol was 302 at 26℃,which was 11.93 times higher than that of pure In_(2)O_(3).Among the eight tested gases,ZnO/In_(2)O_(3)-2 displayed the highest response to ***,the lower detection limit of the ZnO/In_(2)O_(3)nanosheets was reduced from 10×10^(-6)to 0.1×10^(-6)(for pure In_(2)O_(3)nanosheets)toward *** is because the doping of Zn2+increases the number of oxygen vacancies on the sensor surface and allows the formation of an n-n heterostructure between ZnO and In_(2)O_(3),which increases the initial resistance of the sensor.

关键词： High-response N-N heterostructure N-butanol Gas sensor

digestive system involvement and clinical outcomes among COVId-19 patients:A retrospective cohort study from Qatar

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World Journal of Gastroenterology 2021年第46期27卷 7995-8009页

作者： muhammad Umair Khan Kamran mushtaq deema Hussam.alsoub Phool Iqbal Fateen Ata Hammad Shabir Chaudhry Fatima Iqbal Girisha Balaraju muna A al maslamani Betsy Varughese Rajvir Singh Khalid al Ejji Saad al Kaabi Yasser medhat Kamel Adeel Ajwad Butt department of Gastroenterology and Hepatology Hamad Medical CorporationDoha 3050Qatar ECPEExecutive and Continuing Professional Education Harvard T.H Chan School of Public HealthBostonMA 02115-5810United States department of Palliative Care National Center for Cancer Care&ResearchHamad Medical CorporationDoha 3050Qatar department of medicine Hamad Medical CorporationDoha 3050Qatar department of Infectious disease Communicable Disease CenterHamad Medical CorporationDoha 3050Qatar department of Cardiology Research Heart HospitalHamad Medical CorporationDoha 3050Qatar department of medicine Division of Infectious DiseasesWeill Cornell Medical CollegeNew YorkNY 10075United States department of medicine Weill Cornell Medical College-QatarDoha 24144Qatar

BACKGROUNd Coronavirus disease 2019(COVId-19)caused by the severe acute respiratory syndrome coronavirus 2 virus most commonly presents with respiratory *** gastrointestinal(GI)manifestations either at presentation or during hospitalization are also common,their impact on clinical outcomes is *** studies have described worse outcomes in COVId-19 patients with GI symptoms,while others have shown either no association or a protective *** is a need for consistent standards to describe GI symptoms in COVId-19 patients and to assess their effect on clinical outcomes,including mortality and disease *** To investigate the prevalence of GI symptoms in hospitalized COVId-19 patients and their correlation with disease severity and clinical *** We retrospectively reviewed 601 consecutive adult COVId-19 patients requiring hospitalization between may 1-15,*** symptoms were recorded at admission and during ***,clinical,laboratory,and treatment data were *** outcomes included all-cause mortality,disease severity at presentation,need for intensive care unit(ICU)admission,development of acute respiratory distress syndrome,and need for mechanical *** logistic regression model was used to identify independent predictors of the adverse *** The prevalence of any GI symptom at admission was 27.1%and during hospitalization was 19.8%.The most common symptoms were nausea(98 patients),diarrhea(76 patients),vomiting(73 patients),and epigastric pain or discomfort(69 patients).There was no difference in the mortality between the two groups(6.21%vs 5.5%,P=0.7).Patients with GI symptoms were more likely to have severe disease at presentation(33.13%vs 22.5%,Pd prolonged hospital stay(15 d vs 14 d,P=0.04).There was no difference in other clinical outcomes,including ICU admission,development of acute respiratory distress syndrome,or need for mechanical ventil

关键词： COVId-19 Gastrointestinal manifestations mortality Intensive care unit admission mechanical ventilation disease severity

multi-Criteria Analysis on Evaluating Egypt's Electricity Generation Options:Reducing CO2 Emissions and Accommodating Climate Change

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Multi-Criteria Analysis on Evaluating Egypt's Electricity Ge...

作者： ahm.d medhat Abdel moniem Khattab 中国石油大学(北京)

学位级别：硕士

The paper presents the process to select the optimum electricity generation technology which was solved using the Egyptian power sector by applying multi-Criteria decision making methos such as AHP（Analytic Hierarchy Process）and TOPSIS（technique for order performance by similarity to ideal solution）.Taking into consideration the financial,environmental,social,and technical impacts,a set of evaluation criteria were developed for electricity generation *** quantitative and qualitative analysis of the criteria helped in rating the electricity generation technologies and ranking them in order of *** results showed that solar energy is the highest ranked resource,and accordingly the worthiest of expansion and ***,the results also showed that natural gas still managed to become the highest ranked option in several surveys explaining why Egypt have not moved forward with its CO emissions reductions plans,and in some cases,took a step back to fossil *** checks were conducted to confirm the validity of the results.

关键词： multi-Criteria analysis AHP TOPSIS GHG CO2 emissions Renewable Energy Resources (RES)

Expanding the liver donor pool worldwide with hepatitis C infected livers, is it the time?

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World Journal of Transplantation 2024年第2期14卷 13-27页

作者： mai Hashem mohammed A medhat doaa Abdeltawab Nahed A makhlouf Fellow of Tropical medicine and Gastroenterology Assiut University HospitalAssiut 71515Egypt department of Tropical medicine and Gastroenterology Faculty of MedicineAssiut UniversityAssiut 71515Egypt department of Tropical medicine and Gastroenterology Al-Rajhi Liver HospitalAssiut UniversityAssiut 71515Egypt

Liver transplantation(LT)provides a life-saving option for cirrhotic patients with complications and hepatocellular *** the increasing number of liver transplants performed each year,the number of LT candidates on the waitlist remains unchanged due to an im.alance between donor organ supply and the demand which increases the waitlist time and *** donor liver transplant had a great role in increasing the donor pool and shortened waitlist time for LT ***,further strategies can be implemented to increase the pool of potential donors in deceased donor LT,such as reducing the rate of organ *** hepatitis C virus(HCV)seropositive liver grafts is one of the expanded donor organ criteria.A yearly increase of hundreds of transplants is anticipated as a result of maximizing the utilization of HCV-positive organs for HCV-negative ***-acting antiviral therapy's efficacy has revolutionized the treatment of HCV infection and the use of HCV-seropositive donors in *** American Society of Transplantation advises against performing transplants from HCV-infected liver donors(d+)into HCV-negative recipient(R-)unless under Institutional Review Board-approved study rules and with full informed consent of the knowledge gaps associated with such *** selection of patients to be transplanted with HCV-infected grafts and confirming their access to direct-acting antivirals if needed is *** and international consensuses are needed to regulate this process to ensure the maximum benefit and the least adverse events.

关键词： donor pool Hepatitis C-viremic organs Non-viremic organs direct acting antivirals Hepatitis C virus treated Liver transplantation

Numerical Simulation of Groundwater Flow and Solute Transport for the Northern Batinah Area, Oman

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Journal of Environmental Science and Engineering(B) 2015年第6期4卷 287-301页

作者： medhat El-Bihery Abdel Aziz al-mushikhi Salim.al-khanbashi ahm.d al Saeedi ali mohsin al-Lawati maqboul al-Rawahi department of Hydrogeology Water Resources Research Institute National Water Research Center Cairo 13411 Egypt department of Surface Water and Groundwater Assessment Ministry of Regional Municipalities and Water Resources Muscat 113 Sultanate of Oman

The northern Batinah occupies approximately 12,150 km2 in the north of Oman Quaternary deposits and Neogene＇s upper Fats form the aquifer units. mOdFLOW compatible mT3d was used for simulation development of the area. It can be concluded that：（1） The groundwater in the Batinah area generally flows from the south-west to the gulf of Oman in the north-east; （2） Recharge takes place through direct recharge from rainfall and wadi flow by about 902 ×10^3 ma/day; （3） The hydraulic conductivity attains a relatively wide range between 0.02 m/day and 78 m/day and 0.02 m/day and 60 m/day for the Quaternary and Fars respectively; （4） There is probably less potential for groundwater abstraction in the northern part of the area; （5） The water level decreased by about 6 m over 24 years and （6） The increase of salinity most likely due to a contribution of sea water intrusion from the gulf along the coast. It is recommended that：（1） automatic well control system should be installed to accurate measurements of abstraction; （2） further analysis under different future scenarios should be made and （3） formulate an integrated management plan for the basin.

关键词： Groundwater numerical modeling Batinah Oman.

Numerical Study on the Hydrogen Fueled SI Engine Combustion Optimization through a Combined Operation of dI and PFI Strategies

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Energy and Power Engineering 2013年第8期5卷 513-522页

作者： medhat Elkelawy Hagar alm-Eldin Bastawissi department of mechanical Power Engineering Tanta University Tanta Egypt

As the practicability of a hydrogen-fueled economy emerges, intermediate technologies would be necessary for the transition between hydrocarbon fueled internal combustion engines and hydrogen powered fuel cells. In the present study, the hydrogen engine efficiency and the load control are the two main parameters that will be improved by using the combined operation of in-cylinder direct fuel injection (dI) and port fuel injection (PFI) strategies to obtain maximum engine power outputs with acceptable efficiency equivalent to gasoline engines. Wide open throttle (WOT) operation has been used to take advantage of the associated increase in engine efficiency, in which the loads have been regulated with mixture richness (qualitative control) instead of volumetric efficiency (quantitative control). The capabilities of a 3d-CFd code have been developed and employed to simulate the whole engine physicochemical process which includes the hydrogen injection through the intake manifold (PFI) and/or the hydrogen dI in the engine compression stroke. Conditions with simulated PFI, PFI + dI and dI have been analyzed to study the effects of mixture preparation behaviors on the hydrogen ignition and its flame propagation inside the engine combustion chamber. Numerically, the CFd code has been intensively validated against experimental engine data which provided remarkable agreement in terms of in-cylinder pressure history evaluation.

关键词： Hydrogen Fuel SI Engine Port Fuel Injection direct Injection Wide Open Throttle Kiva-3vr2

Numerical investigation to evaluate the effects of gravity and pressure on flame structure and soot formation of turbulent non-premixed methaneair flame

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Propulsion and Power Research 2022年第4期11卷 473-495页

作者： Subrat Garnayak Amjad ali Pasha Radi alsulami medhat A.Nemitallah Abdul Gani Abdul Jameel Sukanta K.dash V.mahendra Reddy School of Energy Science&Engineering Indian Institute of Technology KharagpurWest Bengal721302India department of Aerospace Engineering King Abdulaziz UniversityJeddah21589Saudi Arabia department of mechanical Engineering King Abdulaziz UniversityJeddah21589Saudi Arabia IRC-Hydrogen and Energy Storage and mechanical Engineering department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia department of Chemical Engineering King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Center for Refining&Advanced Chemicals King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia department of mechanical Engineering Indian Institute of Technology KharagpurWest Bengal721302India

In this study,a turbulent non-premixed(diffusion)methane-air flame has been investigated computationally to analyze the influences of pressure and gravity on flame structure and sooting characteristics between 1 and 10 *** simulation has been conducted in a 2-d axisymmetric computational domain using the finite volume-based computational fluid dynamics(CFd)*** interaction of turbulence and chemistry is modeled by considering the steady laminar flamelet model(SLFm)and the GRI mech 3.0 chemical *** radiative heat transfer calculation is carried out by considering the discrete ordinate(dO)method and the weighted sum grey gas model(WSGGm).The semi-empirical moss-Brookes model is considered to calculate *** impact of gravity on flame and sooting characteristics are evaluated by comparing the normal-gravity flames with the zero-gravity *** effect of soot and radiation on flame temperature is also *** results show a close agreement with the measurement when both soot and radiation are included in the numerical *** rates of soot formation,surface growth,and oxidation increase with increased operating pressure,regardless of ***-gravity flames have a higher soot volume fraction,a wider soot-containing zone,a higher CO mass fraction,and a lower flame temperature than normal-gravity flames while maintaining constant *** normal-gravity flames,the CO mass fraction decreases with pressure,whereas it increases with pressure rise in flames of zero *** of zero gravity appear taller and broader compared to the flames of normalgravity for a fixed *** increase in pressure significantly reduces the flame length and width in normal-gravity ***,the pressure elevation has little effect on the shape of a zero-gravity *** outcomes of the present study will assist in fully understanding the combustion and sooting characteristics of turbulent diffusion flames that will help design and develop h

关键词： Computational fluid dynamics(CFd) Flamelet Gravity Pressure Soot

Evaluation of the systematic set-up errors using electronic portal image device in the radiotherapy procedures

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The Chinese-German Journal of Clinical Oncology 2013年第9期12卷 439-442页

作者： Ehab m. Attalla Rizk Abd El moneam Aida R. Tolba maha H.mokhtar medhat W. Ismail Children Cancer Hospital department of Radiotherapy and Nuclear medicine National Cancer Institute Cairo University Faculty of Science Helwan University

Objective： The aim of this work was to quantify the extent of set-up errors to conduct a quality assurance （QA） aspect of treatment delivery, verification of the treatment field＇s position on different days using electronic portal. methods： This study was carried out on 12 patients, treated for pelvis tumor; and total of 240 images obtained by electronic portal image device （EPId） were analyzed. The EPIs acquire using EPId attached to the Siemens linear accelerator. The anatomy match- ing software （Theraview） was used and displacement in two dimensions were noted for each treatment field to study patient setup errors. Results： The percentages of mean deviations less than 5 mm in X direction were 65% ＆ 92%, from 5-10 mm were 31% ＆ 19% and more than 10 mm were 11% ＆ 9% forNP and lateral direction respectively. The percentages of mean deviations less than 5 mm in Y direction were 65% ＆ 63%, from 5-10 mm were 33% ＆ 28% and more than 10 mm were 22% ＆ 29%. The mean deviations in 2d-vector errors were 〈 5 mm in 47% and 46%, 5-10 mm in 36% and 37% and 〉 10 mm in 37% and 37% of images in the NP and lateral direction respectively. Conclusion： The results revealed that the ranges of set up errors are immobilization method to improve reproducibility. The observed variations were not within the limits..

关键词： electronic portal imaging device (EPId) setup errors tumor control probability

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中国投资对埃及经济增长的影响

中国投资对埃及经济增长的影响

作者：李浩博（mohamed medhat Shawki Kenawi Khalifa）西南大学

学位级别：硕士

如今,经济增长已经成为反映一个国家发展水平的最重要因素之一,但是要提高一个国家的经济增长速度发展,就必须提供一些稳定的增长发展因素,其中有一个重要的增长因素就是对外投资。这对埃及来说没有什么不同,在过去的20年里,埃及在外国... 详细信息

如今,经济增长已经成为反映一个国家发展水平的最重要因素之一,但是要提高一个国家的经济增长速度发展,就必须提供一些稳定的增长发展因素,其中有一个重要的增长因素就是对外投资。这对埃及来说没有什么不同,在过去的20年里,埃及在外国投资方面已经成为一个非常有吸引力的国家,但是中国成为了为埃及变成最重要的投资伙伴之一。中埃经济关系发展迅速,近年来,中国成为埃及非常重要的贸易伙伴,也是不同领域的有效投资者。然而,没有足够的研究可以给我们展示中埃两国之间这种合作的重要性,也无法使我们充分了解这种合作的方式,以及这种合作将如何成为两国的双赢局面。本文的主要目的是简要概述中国直接投资对埃及贸易和和经济增长的影响,以及这种投资将如何有益于埃及改善经济状况,并且埃及如何做出与中国的这种合作成为强大而高效的合作,还将检验中国企业在埃及进行投资的时候会面临什么问题,并提供一些解决方案,为了解决这些问题,以使两国中国和埃及从该合作中获得最大利益。为了实现本文的主要目的,按照两国之间的贸易和投资数据要分析中国投资对埃及经济增长在短期间和长期间会有什么影响,并试图找出中国投资与埃及经济增长之间的关系。用了回归模型以检验中国投资怎么影响埃及经济增长以后,发现中国投资对埃及年比一年有不断和稳定的增长,再加上中国投资对埃及经济增开始越来越很重要。研究清楚地表明,在过去的20年里许多国际中国公司在埃及投资了在各种个领域中开始进行投资活动,从汽车、电信、建筑、电子和金融服务到再生能源、石油和天然气,以及中国投资对埃及经济增长有很大的影响,中国投资在埃及越多埃及经济越发展,但是还发现中国投资在埃及尚未达到其全部产能,因为双方中国与埃及还面临一些障碍首先需要克服,以使中国对埃及的投资能够实现两国中国和埃及都希望的预期潜力,并双方中国和埃及从该经济合作中得到最大的收获。

关键词：中国投资埃及经济增长