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International Journal of Ophthalmology(English edition) 2018年第9期11卷 1528-1533页

作者： Amal m Elbendary Hossam youssef Abouelkheir mansoura Ophthalmic Center Mansoura University

AIm： To categorize neovessels morphology and to detect response to anti-angiogenic therapy by using structural and angiographic modes of swept source optical coherence tomography（SS-OCT）.mETHODS： Thirty-two eyes with neovessels at disc（NVD） and neovessels elsewhere（NVE）-as diagnosed by fluorescein angiography-were included. Cross sectional OCT images of disc and macular regions were registered to enface OCT angiography（OCTA）, B-scan blood flow over lay and density maps. Three eyes received antiangiogenic ***： Pin point registration of cross-sectional OCT and OCTA images differentiated active NVD with vascular elements from fibrous or equivalent fibrovascular elements. En face images delineated NVE as vascular tufts or area of filling while cross-sectional images differentiated NVE from microvascular intraretinal abnormality（IRmA）. All cases were associated with enlargement of foveal avascular zone and or areas of capillary non perfusion. Regressed NVD appeared as ghost vessel or pruned vascular loops after ***： Structural and angiographic modes of SS-OCT can detect, characterize and categorize the pattern of wide spectrum of neovessels based on blood flow data and density maps. It is potentially useful to detect ischemic changes in the vascular bed and regression of NVD after therapeutic regimens providing substitute for invasive techniques.

关键词： optical coherence tomography angiography swept proliferative diabetic retinopathy

Fabrication,characterization,and electrical conductivity properties of Pr_6O_(11) nanoparticles

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Journal of Rare Earths 2013年第7期31卷 701-708页

作者： Bahaa m.Abu-Zied youssef A.mohamed Abdullah m.Asiri Chemistry Department Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Chemistry Department Faculty of ScienceAssiut University71516 AssiutEgypt Center of Excellence for Advanced materials Research(CEAmR) King Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

PrrOll nanoparticles were obtained by subsequent thermal decomposition of the as-prepared precipitate formed under ambient temperature and pressure using NaOH as precipitant. The calcination process was affected, for 1 h in static air atmosphere, at 400-700 ℃ temperature range. The different samples were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEm）, field emission scanning electron microscopy （FE-SEm）, thermogravimetric analysis （TGA）, in situ electrical conductivity, and N2 adsorption/desorption. The obtained results demonstrated that nano-crystalline Pr6O11, with crystallites size of 6-12 nm, started to form at 500 ℃. Such value increased to 20-33 nm for the sample calcined at 700℃. The as-synthesized PrrOll nanoparticles presented high electrical conductivity due to electron hopping between Pr（III）-Pr（IV） pairs.

关键词： nanocrystalline praseodymium oxide Pr6O11 nano structured materials electrical conductivity rare earths

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

Ultrafast laser dynamics of metal organic frameworks/TiO_2 nano-arrays hybrid composites for energy conversion applications

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Journal of Energy Chemistry 2019年第2期28卷 88-94页

作者： Fatma m.Ismail Daniel O'Neil Tareq youssef Souad A.Elfeky The National Institute of Laser Enhanced Sciences Cairo University Zewail City of Science and Technology Georgia Institute of Technology

Herein,we report the victorious synthesis of metal-organic frameworks(mOFs) on TiO_2 nanotubes(NTs)using a layer-by-layer(LbL) *** crystalline and homogenous thin films of mOFs were grown and characterized using XRD,SEm,FT-IR and UV/Vis ***,the utilization of the mOF films as sensitizers was probed in bespoke Graetzel type liquid junction solar *** constructed cell performance revealed an I_(sc) of 1.16 mA cm^(–2),Vocof 0.63 V,FF of 0.33,and E_(ff) of 0.42%.Further,pumpprobe transient laser spectroscopy was performed to investigate the energy and charge transfer dynamics of the mOFs/TiO_2 NTs *** results indicated 86% injection *** ultrafast pump-probe spectroscopy allows the investigation of this process and the differences between *** also showed that the relaxation of the mOF chromophores is in competition with electron injection in the Ti O2 *** this study provides a new insight into electron transfer from photoexcited metal-organic frameworks(mOFs) into titanium dioxide.

关键词： Ultrafast laser dynamics metal-organic frameworks TiO2 nano-arrays Energy conversion Thin film

Design framework for robotic surgery wards at hospitals:Computational implementation

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Frontiers of Architectural Research 2020年第3期9卷 514-540页

作者： Randa m.A.mahmoud Amr m.A.youssef Department of Architectural Ensineering Assiut UniversityAssiut 71518Egypt

Robotic surgery is one of the most recent technologies in healthcare building *** to the design complexity of Robotic surgery wards,computational implementations are being developed to either measure the effect of inserting advanced technologies as Electronic medical recorders and tele surgery,or evaluate design alternatives on healthcare *** paper presents a design framework that responds to the need for coordinating design phases for Robotic Surgery Wards(RSWs)*** proposed design framework for RSWs can generate functional RSW alternatives and more than one solution for each *** framework has been structured based on the main architectural considerations of RSWs which are geom etric and topological,the economic considerations,specific developed pools for shape and corridor patterns,and the theory of,fShape Grammars"has been utilized to compute the framework to generate a vast number of design ***,a computational implementation has been established to assist designers in early design *** validation for the applications of the developed framework and implementation has been conducted by using reference examples of *** main finding in this paper is providing healthcare building designers with a computational implementation that generates RSW alternative computationally based on specific shape and cost levels.

关键词： Robotic surgery ward design Architectural and economic design consideration Design framework Computational implementation Shape grammar

Approaches for Delineating Landslide Hazard Areas Using Different Training Sites in an Advanced Artificial Neural Network model

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Geo-Spatial Information Science 2010年第2期13卷 93-102页

作者： Biswajeet Pradhan Ahmed m. youssef Renuganth Varathrajoo Institute of Cartography Faculty of Forestry Hydro and Geosciences Dresden University of Technology Faculty of Engineering University Putra Malaysia Saudi Geological Survey Applied Geology Section Department of Geological Hazards and Engineering

The current paper presents landslide hazard analysis around the Cameron area, malaysia, using advanced artificial neural networks with the help of Geographic Information System (GIS) and remote sensing techniques. Landslide locations were determined in the study area by interpretation of aerial photographs and from field investigations. Topographical and geological data as well as satellite images were collected, processed, and constructed into a spatial database using GIS and image processing. Ten factors were selected for landslide hazard including: 1) factors related to topography as slope, aspect, and curvature; 2) factors related to geology as lithology and distance from lineament; 3) factors related to drainage as distance from drainage; and 4) factors extracted from Tm satellite images as land cover and the vegetation index value. An advanced artificial neural network model has been used to analyze these factors in order to establish the landslide hazard map. The back-propagation training method has been used for the selection of the five different random training sites in order to calculate the factor's weight and then the landslide hazard indices were computed for each of the five hazard maps. Finally, the landslide hazard maps (five cases) were prepared using GIS tools. Results of the landslides hazard maps have been verified using landslide test locations that were not used during the training phase of the neural network. Our findings of verification results show an accuracy of 69%, 75%, 70%, 83% and 86% for training sites 1, 2, 3, 4 and 5 respectively. GIS data was used to efficiently analyze the large volume of data, and the artificial neural network proved to be an effective tool for landslide hazard analysis. The verification results showed sufficient agreement between the presumptive hazard map and the existing data on landslide areas.

关键词： artificial neural network landslide hazard GIS malaysia

Subnormal Serum Liver Enzyme Levels:A Review of Pathophysiology and Clinical Significance

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Journal of Clinical and Translational Hepatology 2024年第4期12卷 428-435页

作者： Elham m.youssef George Y.Wu Biochemistry Department National Research CenterCairoEgypt Department of medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA

Subnormal levels of liver enzymes,below the lower limit of normal on local laboratory reports,can be useful *** instance,subnormal levels of aminotransferases can be observed in vitamin B6 deficiency and chronic kidney *** alkaline phosphatase levels may indicate the presence of hypophosphatasia,Wilson's disease,deficiencies of divalent ions,or *** levels of gamma glutamyl transferase may be seen in cases of acute intrahepatic cholestasis,the use of certain medications,and in bone ***,subnormal levels of 5'-nucleotidase have been reported in lead poisoning and nonspherocytic hemolytic *** aim of this review is to bring attention to the fact that subnormal levels of these enzymes should not be ignored as they may indicate pathological conditions and provide a means of early diagnosis.

关键词： Transaminases Vitamin B6 Celiac disease Renal insufficiency Hepatolenticular Degeneration Crohn disease malnutrition Clofibrate Bone diseases Lead poisoning Anemia Hemolytic

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

Design and experimental testing of a control system for a morphing wing model actuated with miniature BLDC motors

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Chinese Journal of Aeronautics 2020年第4期33卷 1272-1287页

作者： Teodor Lucian GRIGORIE Shehryar KHAN Ruxandra mihaela BOTEZ mahmoud mAmOU youssef méBARKI ETS Laboratory of Active ControlsAvionics and AeroServoElasticity LARCASEMontreal H3C-1K3QuebecCanada military Technical Academy"Ferdinand I" Bucharest 040531Romania Aerodynamics Laboratory NRC AerospaceNational Research Council CanadaOttawa K1A0R6OntarioCanada

The paper deals with the design and experimental validation of the actuation mechanism control system for a morphing wing *** experimental morphable wing model manufactured in this project is a full-size scale wing tip for a real aircraft equipped with an *** morphing actuation of the model is based on a mechanism with four similar in house designed and manufactured actuators,positioned inside the wing on two parallel *** of the four actuators used a BrushLess Direct Current(BLDC)electric motor integrated with a mechanical part performing the conversion of the angular displacements into linear *** following have been chosen as successive steps in the design of the actuator control system:(A)mathematical and software modelling of the actuator;(B)Design of the control system architecture and tuning using Internal model Control(ImC)methodology;(C)Numerical simulation of the controlled actuator and its testing on bench and wind *** morphing wing experimental model is tested both at the laboratory level,with no airflow,to evaluate the components integration and the whole system functioning,but also in the wind tunnel,in the presence of airflow,to evaluate its behavior and the aerodynamic gain.

关键词： BLDC motor Control tuning morphing wing Simulation and experimental testing Wind tunnel

Landslide susceptibility mapping using machine learning algorithms and comparison of their performance at Abha Basin,Asir Region,Saudi Arabia

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Geoscience Frontiers 2021年第2期12卷 639-655页

作者： Ahmed mohamed youssef Hamid Reza Pourghasemi Geology Department Faculty of ScienceSohag UniversityEgypt Geological Hazards Department Applied Geology SectorSaudi Geological SurveyP.O.Box 54141Jeddah21514Saudi Arabia Department of Natural Resources and Environmental Engineering College of AgricultureShiraz UniversityShirazIran

The current study aimed at evaluating the capabilities of seven advanced machine learning techniques(mLTs),including,Support Vector machine(SVm),Random Forest(RF),multivariate Adaptive Regression Spline(mARS),Artificial Neural Network(ANN),Quadratic Discriminant Analysis(QDA),Linear Discriminant Analysis(LDA),and Naive Bayes(NB),for landslide susceptibility modeling and comparison of their *** machine learning algorithms with spatial data types for landslide susceptibility mapping is a vitally important *** study was carried out using GIS and R open source software at Abha Basin,Asir Region,Saudi ***,a total of 243 landslide locations were identified at Abha Basin to prepare the landslide inventory map using different data *** the landslide areas were randomly separated into two groups with a ratio of 70%for training and 30%for validating *** landslide-variables were generated for landslide susceptibility modeling,which include altitude,lithology,distance to faults,normalized difference vegetation index(NDVI),landuse/landcover(LULC),distance to roads,slope angle,distance to streams,profile curvature,plan curvature,slope length(LS),and *** area under curve(AUC-ROC)approach has been applied to evaluate,validate,and compare the mLTs *** results indicated that AUC values for seven mLTs range from 89.0%for QDA to 95.1%for *** findings showed that the RF(AUC=95.1%)and LDA(AUC=941.7%)have produced the best performances in comparison to other *** outcome of this study and the landslide susceptibility maps would be useful for environmental protection.

关键词： Landslide susceptibility machine learning algorithms Variables importance Saudi Arabia