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Open Journal of Obstetrics and Gynecology 2020年第12期10卷 1788-1802页

作者： Ahmed Mohammed Abbas Manal Mahmoud Elhalwagy Khaled Afifi Khaled Ibrahim mohamed samir sweed Obstetrics & Gynecology Ain Shams University Cairo Egypt Obstetrics & Gynecology Helwan General Hospital Cairo Egypt

Introduction: It is estimated that about 18% of pregnant women suffer from iron deficiency anemia throughout their whole pregnancy. In twin pregnancy, owing to the relatively greater feto-placental requirements and greater expansion in maternal plasma volume and red cell mass, iron requirements are magnified 1.8 times compared to singleton pregnancies. However, for prevention of iron deficiency in twin pregnancy, only sparse data exist regarding the sufficiency of the standard antenatal iron supplementation dose used in singleton pregnancies to meet the increased iron demand. In this study, we investigate the effect of single and double dose iron supplementation for prevention of iron deficiency anemia in twin pregnancy. Methods: A randomized controlled clinical trial was conducted at our center in the period between February 2019 and October 2020, and included 450 eligible healthy non-anemic women aged 18 - 35 year

关键词： Iron Supplementation Iron Deficiency Anemia Twin Pregnancy Hepcidin Mucosal Block

Spatial Variability and Cartography of Maximum Annual Daily Rainfall under Different Return Periods in Northern Algeria

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Journal of Mountain Science 2015年第6期12卷 1403-1421页

作者： MEDDI mohamed TOUMI samir National High School of Hydraulic (ENSH)

The estimation of precipitation quantiles has always been an area of great importance to meteorologists, hydrologists, planners and managers of hydrotechnical infrastructures. In many cases, it is necessary to estimate the values relating to extreme events for the sites where there is little or no measurement, as well as their return periods. A statistical approach is the most used in such cases. It aims to find the probability distribution that best fits the maximum daily rainfall values. In our study, 231 rainfall stations were used to regionalize and find the best distribution for modeling the maximum daily rainfall in Northern Algeria. The L-moments method was used to perform a regionalization based on discordance criteria and homogeneity test. It gave rise to twelve homogeneous regions in terms of LCoefficient of variation(L-CV), L-Skewness(L-CS) and L-Kurtosis(L-CK). This same technique allowed us to select the regional probability distribution for each group using the Z statistic. The generalized extreme values distribution(GEV) was selected to model the maximum daily rainfall of 10 groups located in the north of the steppe region and the generalized logistic distribution(GLO) for groups representing the steppes of Central and Western Algeria. The study of uncertainty by the bias and RMSE showed that the regional approach is acceptable. We have also developed maximum daily rainfall maps for 2, 5, 10, 20, 50 and 100 years return periods. We relied on a network of 255 rainfall stations. The spatial variability of quantiles was evaluated by semi-variograms. All rainfall frequency models have a spatial dependence with an exponential model adjusted to the experimental semi-variograms. The parameters of the fitted semi-variogram for different return periods are similar, throughout, while the nugget is more important for high return periods. Maximum daily rainfall increases from South to North and from West to East, and is more significant in the coastal areas of ea

关键词： Annual maximum daily rainfall Regionalisation L-moments Mapping Northern Algeria

Development of Magnetite/Graphene Oxide Hydrogels from Agricultural Wastes for Water Treatment

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Journal of Renewable Materials 2022年第7期10卷 1889-1909页

作者： Hebat-Allah STohamy mohamed El-Sakhawy samir Kamel Cellulose and Paper Department National Research CentreCairo12622Egypt

A novel magnetic hydrogel loaded with graphene oxide(GO)was developed in this ***,GO was prepared from bagasse through a single step via oxidation in the presence of ferrocene under muffled atmospheric conditions,followed by the loading of different amounts of magnetite onto GO via co-precipitation reaction of iron onto GO ***,the 2-acrylamido-2-methyl-1-propane sulfonic acid was grafted onto carboxymethyl cellulose in the presence of magnetite GO and N,N′-methylenebisacrylamide as crosslinker yielded *** structure,morphological,and thermal behavior of the prepared hydrogels were *** addition,the adsorption performance of Ni(Ⅱ)ions from aqueous media by the prepared hydrogels was investigated as a function of temperature,time,and concentration of adsorbate in a batch *** results demonstrated a remarkable enhancement in the adsorption process of Ni(Ⅱ)(Removal efficiency=98.82%).All isotherms were found to fit the Langmuir model *** adsorption properties of both magnetic GO and magnetic hydrogel showed promising properties as green and cheap adsorbents.

关键词： Magnetite graphene oxide hydrogel Ni(Ⅱ)adsorption kinetic models thermodynamics

Microstructure of coupled Al/gray cast iron obtained by molding and its effect on mass loss

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China Foundry 2018年第5期15卷 378-383页

作者： mohamed Bouitna Naima Boutarek-Zaourar samir Mansour samir Mourad Chentouf Eric Mossang Laboratory of Materials Technology Faculty of Mechanical Engineering and Process EngineeringUniversity of Science and Technology Houari BoumedieneB.P.32 El Alia16111 AlgiersAlgeria Department of Mechanical Engineering School of Technology Superior1100 Notre-Dame Street WestMontrealQuebec H3C 1K3Canada NEEI Institute National Center for Scientific Research25rue des MartyrsBO 16638042Grenoble CedexFrance

This study aims to consolidate the surface of gray cast iron with aluminum deposition by developing a method that combines the preparation and surface treatment in a single operation. The effect of the wall thickness of the castings on the microstructure of the formed layers was studied, and two thicknesses, 8 mm and 25 mm, were studied. The formation of a continuous and homogeneous rich aluminum layer on the surface of the cast iron was observed. The formed layer is composed of two successive zones identified as two proeutectoid phases FeAl+FeAl/FeAl2 and single-phase FeAl, which significantly increases the surface hardness. Furthermore, this change in surface composition makes it possible to reduce the mass of the immersed samples in a 1 M hydrochloric acid solution during different exposure times(1 to 4 days). Consequently, a clear improvement in the corrosion resistance of the treated layers is highlighted.

关键词： gray cast iron aluminum coating treatment in the mold mass loss

Transpressive Structures in the Ghadir Shear Belt, Eastern Desert, Egypt: Evidence for Partitioning of Oblique Convergence in the Arabian-Nubian Shield during Gondwana Agglutination

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Acta Geologica Sinica(English Edition) 2019年第6期93卷 1614-1646页

作者： mohamed ABD EL-WAHED samir KAMH Mahmoud ASHMAWY Aly SHEBL Geology Department Faculty of Science Tanta University

Transpressional deformation has played an important role in the late Neoproterozoic evolution of the ArabianNubian Shield including the Central Eastern Desert of *** Ghadir Shear Belt is a 35 km-long,NW-oriented brittleductile shear zone that underwent overall sinistral transpression during the Late *** this shear belt,strain is highly partitioned into shortening,oblique,extensional and strike-slip structures at multiple ***,strain partitioning is heterogeneous along-strike giving rise to three distinct structural *** the East Ghadir and Ambaut shear belts,the strain is pure-shear dominated whereas the narrow sectors parallel to the shear walls in the West Ghadir Shear Zone are simple-shear *** domains are comparable to splay-dominated and thrust-dominated strike-slip shear *** kinematic transition along the Ghadir shear belt is consistent with separate strike-slip and thrustsense shear *** earlier fabric(S1),is locally recognized in low strain areas and SW-ward thrusts.S2 is associated with a shallowly plunging stretching lineation(L2),and defines^NW-SE major upright macroscopic folds in the East Ghadir shear belt.F2 folds are superimposed by^NNW–SSE tight-minor and major F3 folds that are kinematically compatible with sinistral transpressional deformation along the West Ghadir Shear Zone and may represent strain partitioning during deformation.F2 and F3 folds are superimposed by ENE–WSW gentle F4 folds in the Ambaut shear *** sub-parallelism of F3 and F4 fold axes with the shear zones may have resulted from strain partitioning associated with simple shear deformation along narrow mylonite zones and pure shear-dominant deformation in fold *** ENEstriking shear zones were subsequently active at ca.595 Ma,coeval with sinistral shearing along NW-to NNW-striking shear *** occurrence of upright folds and folds with vertical axes suggests that transpression plays a significant role in

关键词： Arabian-Nubian Shield Ghadir shear belt transpression splay-dominated and thrust-dominated strike-slip shear zones Egypt

Wood By-Products as UV Protection:A Consequence Review

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Journal of Renewable Materials 2024年第4期12卷 699-720页

作者： Naglaa Salem El‑Sayed mohamed Hasanin samir Kamel Cellulose and Paper Department National Research CentreCairo12622Egypt

In recent decades,the ozone layer has suffered considerable damage,increasing the entry of ultraviolet(UV)light into the atmosphere and reaching the earth’s surface,negatively affecting ***,researchers aimed to solve this problem by synthesizing advanced UV-shielding *** the other hand,developing an easy and green strategy to prepare functional materials with outstanding properties based on naturally abundant and environmentally friendly raw materials is highly desirable for sustainable *** biomass-derived materials are sustainable and biodegradable,they present a promising substitute for petroleum-based *** three main structural constituents of the plant biomass-based materials that are naturally available are cellulose,hemicellulose,and *** review details current developments using wood-based products such as cellulose,hemicellulose,and lignin in UV-shielding *** will start with assembling the structure and chemistry of cellulose,hemicellulose,and lignin,followed by their contributions to preparing UV-shielding ***,it will briefly discuss the different processing methods for the design of UV-shielding *** wood by-products offer additional opportunities to use the whole tree harvest.

关键词： UV-shielding wood cellulose lignin hemicellulose sunlight protection

EJUSTCO:Monte Carlo radiation transport code hybrid with ANN model for gamma-ray shielding simulation

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Nuclear Science and Techniques 2023年第9期34卷 155-176页

作者： Joseph Konadu Boahen Ahmed S.G.Khalil Mohsen A.Hassan samir A.Elsagheer mohamed Materials Science and Engineering Department School of Innovative Design EngineeringEgypt-Japan University of Science and Technology(E-JUST)179New Borg El-Arab CityEgypt Physics Department Environmental and Smart Technology GroupFaculty of ScienceFayoum UniversityFayoum 63514Egypt Faculty of Engineering Aswan UniversityAswanEgypt

Gamma ray shielding is essential to ensure the safety of personnel and equipment in facilities and environments where radiation *** Monte Carlo technique is vital for analyzing the gamma-ray shielding capabilities of *** this study,a simple Monte Carlo code,EJUSTCO,is developed to cd simulate gamma radiation transport in shielding materials for academic *** code considers the photoelectric effect,Compton(incoherent)scattering,pair production,and photon annihilation as the dominant interaction mechanisms in the gamma radiation shielding *** reduction techniques,such as the Russian roulette,survival weighting,and exponential transformation,are incorporated into the code to improve computational *** the exponential transformation parameter typically requires trial and error as well as ***,a deep learning neural network is proposed as a viable method for predicting this parameter for the first *** model achieves an MSE of 0.00076752 and an R-value of *** exposure buildup factors and radiation dose rates due to the passage of gamma radiation with different source energies and varying thicknesses of lead,water,iron,concrete,and aluminum in single-,double-,and triple-layer material systems are validated by comparing the results with those of MCNP,ESG,ANS-6.4.3,MCBLD,MONTEREY MARK(M),PENELOPE,and *** errors of 5.6%,2.75%,and 10%are achieved for the exposure buildup factor in single-,double-,and triple-layer materials,respectively.A significant parameter that is not considered in similar studies is the gamma ray *** the EJUSTCO code,the total number and energy albedos have been *** results are compared with those of MCNP,FOTELP,and *** general,the EJUSTCO-developed code can be employed to assess the performance of radiation shielding materials because the validation results are consistent with theoretical,experimental,and literary results.

关键词： Monte Carlo Gamma rays Shielding Artificial neural network Simulation

Development of a Smart Technique for Mobile Web Services Discovery

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Computers, Materials & Continua 2021年第11期69卷 1483-1501页

作者： mohamed Eb-Saad Yunyoung Nam Hazem M.El-bakry samir Abdelrazek Department of Information Systems Faculty of Computers and InformationMansoura UniversityMansoura35516Egypt Department of Computer Science and Engineering Soonchunhyang UniversityAsan31538Korea

Web service(WS)presents a good solution to the interoperability of different types of systems that aims to reduce the overhead of high processing in a resource-limited *** the increasing demand for mobile WS(MWS),the WS discovery process has become a significant challenging point in the WS lifecycle that aims to identify the relevant MWSs that best match the service *** discovery process is a resource-consuming task that cannot be performed efficiently in a mobile computing environment due to the limitations of mobile ***,a cloud computing can provide rich computing resources for mobile environments given its unlimited and easily scalable *** paper proposes a semantic WS discovery and invocation framework in mobile environments based on cloud and a relationship-aware matchmaking *** discovery algorithm enriches MWS and user requests semantically with the functional and non-functional properties of Ontology Web Language for Services,such as Quality of Web Service,device context,and user *** WS repository is filtered based on logical reasoning and a parameter-based matching algorithm to minimize the matching space and improve runtime *** cosine similarity between the user request and services repository is then assessed to generate the most relevant *** relationships among concepts in the ontology are considered to improve the recall and precision *** the WS discovery process,users can invoke and test these services in a mobile environment through a dynamic user *** interface of the invocation process is changed according to the WS description *** application prototype is also developed to evaluate the framework based on a Cordova cross-mobile development framework.

关键词： Cloud web service web service discovery semantic matching mobile web service discovery

Preparation of ammonium nitrate-based solid composite propellants supplemented with polyurethane/nitrocellulose blends binder and their thermal decomposition behavior

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Defence Technology（防务技术） 2022年第11期18卷 2023-2033页

作者： Sabri Touidjine Moulai Karim Boulkadid Djalal Trache samir Belkhiri Abderrahmane Mezroua mohamed Islam Aleg Afaf Belkebiche Energetic Propulsion Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria Energetic Materials Laboratory Teaching and Research Unit of Energetic ProcessesEcole Militaire PolytechniqueBP 17Bordj-El-Bahri16046AlgiersAlgeria

To improve the performance of solid composite propellants(SCPs)supplemented with ammonium nitrate(AN)as an oxidizer,the incorporation of energetic ingredients such as explosives,energetic binders or catalysts is a common effective *** this purpose,polyurethane(PU),a typical inert binder,was mixed with nitrocellulose(NC)as an energetic *** composite solid propellant compositions based on AN and NC-modified polyurethane binder with different NC ratios were *** prepared formulations were characterized using Fourier transform infrared spectroscopy(FTIR),RAMAN spectroscopy,X-ray diffraction(XRD),electron densimetry,thermogravimetric(TG)analysis,and differential scanning calorimetry(DSC).A kinetic study was then performed using the iterative KissingerAkahira-Sunose(It-KAS),Flynn-Wall-Ozawa(It-FWO),and non-linear Vyazovkin integral with compensation effect(VYA/CE)*** theoretical performances,such as theoretical specific impulse,adiabatic flame temperature,and ideal exhaust gaseous species,were also determined using the NASA Lewis Code,Chemical Equilibrium with Application(CEA).Spectroscopic examinations revealed the existence of NC and full polymerization of PU in the prepared *** to density tests,the density of the propellant increases as the nitrocellulose component *** to the thermal analysis and kinetics study,the increase in NC content catalyzed the thermal decomposition of the AN-based composite solid *** on the theoretical study,increasing the amount of NC in the propellant increased the specific impulse and,as a result,the overall performance.

关键词： Composite propellants Polyurethane Nitrocellulose Ammonium nitrate Decomposition kinetics Thermal decomposition

Electroconductive Composites Containing Nanocellulose,Nanopolypyrrole,and Silver Nanoparticles

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Journal of Renewable Materials 2019年第2期7卷 193-203页

作者： samir Kamel Ahmed A.Haroun Amany M.EI-Nahrawy mohamed A.Diab Cellulose and Paper Department National Research Centre33 El Bohouth st.Dokki GizaP.O.12622Egypt Industrial Research Division National Research Centre33 El Bohouth st.Dokki GizaP.O.12622Egypt Solid State physics Department Physics Research DivisionNational Research Centre33 El Bohouth st.Dokki GizaP.O.12622Egypt

In this work,conducting composites of nanocellulose(NC)/polypyrrole nanoparticles(NPPy)and silver nanoparticles(AgNPs),i.e.,NC/NPPyAg,were synthesized for the first time,to the best of our knowledge,via in situ emulsion polymerization of pyrrole in the presence of surfactant *** AgNPs acted as an oxidizing agent to simultaneously incorporate nanoparticles into the prepared *** structures and morphologies of the prepared composites were studied using Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),UV-Vis Spectra,thermogravimetric analysis(TGA),and scanning and transmission electron microscopy(SEM and TEM)***,the prepared composites were characterized by their conductivities,and the dielectric constants(e΄),dielectric losses(e˝),and AC conductivities were studied for the prepared composites with an increasing NPPy content as a function of the frequency.

关键词： Nanocellulose nanopolypyrrole emulsion polymerization silver nanoparticles conductive nanocomposites