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Underground Space 2019年第2期4卷 109-120页

作者： mohamed Mahjoub ahmed Rouabhi Mines ParisTech PSL Research UniversityCentre de Ge´osciencesFontainebleauFrance

To better describe excavation operations in deep geological formations,several aspects should be considered,especially the material anisotropy,time-dependent behavior,and hydromechanical *** the present paper,a hydromechanical model based on the framework of continuous porous media was *** mechanical elasto-viscoplastic constitutive model accounted for the material elastic and non-elastic anisotropies,using a transformation between the real transversely isotropic material and a fictitious isotropic *** the hydraulic behavior,the permeability was expressed as a function of the volumetric viscoplastic *** model was applied to a case study of two tunnel excavations in an anisotropic rock under an initial anisotropic stress *** results of the numerical simulations using a finite element code were in good agreement with the field convergence and permeability data.

关键词： Hydromechanical behavior Transverse isotropy Tunnel excavation Viscoplasticity Permeability

Exact and heuristic formulae to compute the geodetic height from the ellipse equation

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Geodesy and Geodynamics 2024年第2期15卷 150-155页

作者： mohamed Eleiche ahmed Hamdi Mansi Construction Department Faculty of EngineeringEgyptian Russian UniversityCairoEgypt Istituto Nazionale di Geofisica e Vulcanologia Sezione di PisaPisaPlItaly

The conversion of the cartesian coordinates of a point to its geodetic equivalent coordinates in reference to the geodetic ellipsoid is one of the main challenges in *** ellipse equation in the meridian plane significantly influences the value of the geodetic *** research analyzes this influence and how it can contribute to their *** study investigates the mathematical relation between them and presents an exact formula relating to the geodetic height and the ellipse *** addition,a heuristic formula for the relation between the geodetic height and the ellipse equation is proposed,which is independent of the geodetic latitude and has a relative accuracy better than 99.9 %.The calculation is stable,and the cost is low.

关键词： Ellipse equation Geodetic height Heuristic geodetic height

In vitro and in vivo evaluation of cubosomes containing 5-fluorouracil for liver targeting

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Acta Pharmaceutica Sinica B 2015年第1期5卷 79-88页

作者： mohamed Nasr mohamed K.Ghorab ahmed Abdelazem Department of Pharmaceutics and Industrial Pharmacy Faculty of Pharmacy Helwan University Department of Pharmaceutical Chemistry Faculty of Pharmacy Helwan University

The objective of this study was to prepare cubosomal nanoparticles containing a hydrophilic anticancer drug 5-fluorouracil(5-FU) for liver targeting. Cubosomal dispersions were prepared by disrupting a cubic gel phase of monoolein and water in the presence of Poloxamer 407 as a *** loaded with 5-FU were characterized in vitro and in vivo. In vitro, 5-FU-loaded cubosomes entrapped 31.21% drug and revealed nanometer-sized particles with a narrow particle size distribution. In vitro 5-FU release from cubosomes exhibited a phase of rapid release of about half of the entrapped drug during the first hour, followed by a relatively slower drug release as compared to 5-FU solution. In vivo biodistribution experiments indicated that the cubosomal formulation significantly(Po 0.05) increased5-FU liver concentration, a value approximately 5-fold greater than that observed with a 5-FU ***, serum serological results and histopathological findings revealed greater hepatocellular damage in rats treated with cubosomal formulation. These results demonstrate the successful development of cubosomal nanoparticles containing 5-FU for liver targeting. However, further studies are required to evaluate hepatotoxicity and in vivo antitumor activity of lower doses of 5-FU cubosomal formulation in treatment of liver cancer.

关键词： 5-Fluorouracil Hydrophilic drug Cubosomes Liver targeting Hepatotoxicity

Remote Monitoring of Electric Vehicle Charging Stations in Smart Campus Parking Lot

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Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 124-132页

作者： mohamed A.ahmed mohamed R.El-Sharkawy Young-Chon Kim Department of Electronic Engineering Universidad Técnica Federico Santa MaríaValparaíso 2390123Chile Department of Communications and Electronics Higher Institute of Engineering&TechnologyKing MarriottAlexandria 23713Egypt Department of Automotive and Tractor Engineering Minia UniversityEl-Minia 61111Egypt Department of Computer Engineering Chonbuk National UniversityJeonju 561-756Korea

Smart parking lots are smart places capable of supporting both parking and charging services for electric vehicles(EVs).In order to manage EV charging,the parking lot local controller(PLLC)requires data exchange with EV charging stations(EVCSs)through communication ***,data losses and communication delays are unavoidable and may significantly degrade the system *** work aims to investigate the underlying communication networks for remote monitoring of EVCSs in a smart campus parking *** communication network consists of two subnetworks:parking area network(PAN)and campus area network(CAN).PAN covers communication among EVs,charging stations and PLLC,while CAN enables dedicated communication between PLLCs and a global controller of the *** one of the major obstacles in EV system is the lack of unified communication architecture to integrate EVCS in the power grid,we develop communication models for the in-vehicle system and EVCSs based on logical node concept of IEC 61850 ***,we implement network models for EVCSs using OPNET *** communication technologies and configurations are considered in modeling and simulations,and end-toend delay is evaluated and discussed.

关键词： Communication network electric vehicle(EV) electric vehicle charging station(EVCS) IEC 61850 OPNET smart parking lot

Insights into the adsorption performance and mechanism of Cr(Ⅵ)onto porous nanocomposite prepared from gossans and modified coal interface:Steric,energetic,and thermodynamic parameters interpretations

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Chinese Journal of Chemical Engineering 2023年第9期61卷 118-128页

作者： mohamed Mobarak Saleh Qaysi mohamed Saad ahmed Yasser F.Salama ahmed mohamed Abbass mohamed Abd Elrahman Hamdy AAbdel-Gawwad Moaaz K.Seliem Physics Department Faculty of ScienceBeni-Suef UniversityEgypt Geology and Geophysics Department College of ScienceKing Saud University11451 RiyadhSaudi Arabia Geology Department Faculty of ScienceBeni-Suef UniversityEgypt Department of Building Materials and Construction ChemistryInstitute of Civil EngineeringTechnische Universitat BerlinBerlinGermany Structural Engineering Department Faculty of EngineeringMansoura UniversityMansouraEgypt Raw Building Materials and Processing Technology Research Institute Housing and Building National Research Center(HBRC)CairoEgypt Faculty of Earth Science Beni–Suef UniversityEgypt

Herein,iron oxide/hydroxides deposits(gossans)were utilized,for the first time,in the fabrication of magnetite nanoparticles(MNPs)to load modified coal(MC).The as-synthesized MNPs@MC composite was characterized via different techniques and utilized for the Cr(Ⅵ)*** studies supported by theoretical treatment were applied to offer a new overview of the Cr(Ⅵ)adsorption geometry and mechanism at 25-45℃.Experimental results suggested that the Cr(Ⅵ)uptake was mainly governed by adsorption-reduction coupled *** Langmuir model fitted well the Cr(Ⅵ)adsorption data with maximum adsorption capacities extended from 115.24 to 129.63 mg·g^(-1).Theoretical calculations indicated that Cr(Ⅵ)ions were adsorbed on the MNPs@MC following the theory of the advanced monolayer statistical *** number of ions removed per site ranged from 1.88 to1.23 suggesting the involvement of vertical geometry and multi-ionic mechanism at all *** increment of the active sites density and the adsorption capacity at saturation with improving temperature reflected an endothermic ***,the Cr(Ⅵ)adsorption was controlled by physical forces as the adsorption energies were less than 40 kJ·mol^(-1).The calculated free enthalpy,*** internal energy explained the spontaneous nature and the viability of Cr(Ⅵ)adsorption on the MNPs@MC *** results offer a new approach in utilizing the iron-rich deposits as gossans in the preparation of magnetic and low-cost adsorbents for wastewater remediation.

关键词： Coal Magnetic nanoparticles Cr(Ⅵ)adsorption Statistical models Thermodynamic parameters

SYNTHESIS,CHARACTERIZATION AND ENHANCED ELECTRICAL PROPERTIES OF CTAB-DIRECTED POLYANILINE NANOPARTICLES

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Chinese Journal of Polymer Science 2011年第2期29卷 181-190页

作者： Lal Said Jan mohamed ahmed Siddig Department of Physics Postgraduate College Mardan23200Khyber PakhtunkhwaPakistan School of Physics and Applied Physics Faculty of Science and TechnologyEL Neelain UniversityKhartoumSudan

Inverse microemulsion system of cetyltrimethylammonium bromide（CTAB） molecules is utilized for virtually monodispersed and controlled growth of HCl polyaniline（PANI） nanoparticles at room temperature（ca.300 K）.The templated electroconductive polymer reveals lamellar crystalline structure under X-ray diffraction signifying marked sub-chain alignment of the polymerized *** nanostructured polymer has spherically symmetric morphology in a size range of 2.0 nm to 6.0 nm under electron microscope *** permeation chromatography gives polydispersity index of 1.02 for nanostructured polymer in agreement with the size monodispersity transpired by electron *** *** conductivityσ_（dc） of PANI at room temperature is 10.11 S/cm whereas the variation of conductivity with temperature in the range 227-303 *** that the conducting mechanism can be considered as three-dimensional variable-range-hopping（3D-VRH）.UV-Vis spectrum indicates two broad absorption bands due to polaron formation that contributes to enhanced electrical conductivity of the *** fundamental absorption edge in the polymer is formed by direct allowed transitions to the extent that the optical band gap value was found to be 2.35 *** crystalline nanostructure and homogeneous doping attained in the cationic template of amphiphile are argued as contributing factors to the enhanced conductivity of the polymer.

关键词： Polyaniline Nanostructured Band gap energy Electrical conductivity

Atezolizumab and bevacizumab combination in advanced hepatocellular carcinoma patients:The imperative for safety assessment studies

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World Journal of Clinical Cases 2025年第9期13卷 56-59页

作者： Mina Tharwat ahmed Tawheed mohamed El-Kassas Department of Tropical Medicine and Gastroenterology Faculty of MedicineAswan UniversityAswan 81528Egypt Department of Endemic Medicine Faculty of MedicineHelwan UniversityCairo 11795Egypt

Hepatocellular carcinoma(HCC)is the most prevalent cancer of the hepatobiliary tract and the third leading cause of cancer-related mortality *** and bevacizumab combination is currently considered among the frontline treatment modalities for advanced unresectable *** studies examining this combination were focused on evaluating its *** numerous case reports documenting some side effects,there is a limited number of large-scale studies assessing these side *** this article,we comment on the case report by Park et al published recently,reporting a fatal intra-tumoral hemorrhage in a patient with HCC who received systemic therapy in the form of the combination of atezolizumab and bevacizumab.

关键词： Hepatocellular carcinoma Atezolizumab Bevacizumab Hemorrhage Side effects

Detection of schistosomiasis antibodies in urine patients as a promising diagnostic maker

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Asian Pacific Journal of Tropical Medicine 2011年第10期4卷 773-777页

作者： Salma Medani Elhag Eshtiyag Abdalla Abdelkareem Ashraf Siddig yousif Ehab ahmed Frah ahmed Babiker mohamed Department of Vector and Biomedical Studies Tropical Medicine Research InstituteNational Centre for ResearchKhartoumSudan Department of Immunology and Biotechnology Tropical Medicine Research InstituteNational Centre for ResearchKhartoumSudan National Centre for Research Ministry of Science and TechnologyKhartoumSudan

Objective:To determine secreted antischistosoma antibodies in urine and to discern the epidemiological situation of schistosomiasis in the agricultural field labourers’camps city in the Gezira State-central ***:Total of 66 urine and 66 serum paired samples were collected from those who confirmed parasitologically positive and negative with schistosomiasis from the two *** were tested using ELBA technique to measure and compare the immunoglobulin G(IgG) levels in serum and urine samples of schistosomiasis ***: The overall prevalence of *** and *** was 53.8%and 15.4%,while the intensity were(2.04 GMEC) and(0.9 GMEC) *** relative percentage of positive IgG individulas in urine was 92.40%where as 96.97%in *** no significant difference between the IgG levels in serum and urine samples was ***:This study shows that the detection of secreted IgG antibodies in urine can substitute serum for diagnosis of schistosomiasis.

关键词： Circulating antibodies Schistosomiasis Immunoglobulin G ELISA

DECAY ESTIMATES FOR ISENTROPIC COMPRESSIBLE MAGNETOHYDRODYNAMIC EQUATIONS IN BOUNDED DOMAIN

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Acta Mathematica Scientia 2012年第6期32卷 2211-2220页

作者： mohamed ahmed Abdallah 江飞谭忠 School of Mathematical Sciences Xiamen University College of Mathematics and Computer Science Fuzhou University Institute of Applied Physics and Computational Mathematics

In this paper, under the hypothesis that y is upper bounded, we construct a Lyapunov functional for the multidimensional isentropic compressible magnetohydrodynamic equations and show that the weak solutions decay exponentially to the equilibrium state in L2 norm. Our result verifies that the method of Daoyuan Fang, Ruizhao Zi and Ting Zhang I1] can be adapted to magnetohydrodynamic equations.

关键词： Navier-Stokes equations weak solution decay estimates magnetohydrody-namic

Using nanotechnology to prevent fines migration while production

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Petroleum 2021年第2期7卷 168-177页

作者： mohamed Mansour mohamed Eleraki ahmed Noah El-Abbas Moustafa Faculty of Science Zagazig UniversityEgypt Egyptian Petroleum Research Institute(EPRI) Egypt The British University Egypt

Formation damage due to fines migration is a major reason for well productivity decline for oil and gas *** fines are small enough to pass through pore throats causing pore plugging and permeability *** factors affect fines migration such as flow rate,salinity,pH value,reservoir temperature and oil polarity,as well as changes in chemical environment induced by Enhanced Oil Recovery(EOR)*** paper focuses on the effect of flow rates on fines detachment from the grain surfaces,which causing permeability *** the fluid inside the reservoir moves towards the wellbore,the fluid velocity increases,when the fluid reaches the critical flow rate these fines can be picked up into the *** fines captured by thinner pore throats causing pore plugging and permeability *** concentrations of nanoparticles were used to fix these fines on their sources and prevent their mobilization at high flow *** unique technique used in this study is changing the potential surfaces between fines and grain surfaces to prevent fines movement above the critical flow ***_(2)and MgO NPs used in this study can be adsorbed on the pore surfaces and reduce the repulsion forces between fines and pore ***_(2) and MgO nanoparticles at different concentrations(0.25,0.50 and 0.75 g/L)were used on treating the Abu-Rawash sandstone reservoir using Formation Damage System Cell *** experimental studies showed that using MgO NPs would prevent fines detachment from the pore surfaces and decrease the reduction of permeability at high flow rates more than SiO_(2) *** optimum concentration of MgO NPs was at 0.5 g/L as the permeability remediation at this concentration reaches to 64.83%.

关键词： Formation damage Fines migration Nanoparticles Zeta potential Permeability reduction Fluid flow rate