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Free radical scavenging activity of three different flowers-Hibiscus rosa-sinensis,Quisqualis indica and Senna surattensis

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Asian Pacific Journal of Tropical Biomedicine 2016年第9期6卷 771-777页

作者： abd el-moneim mohamed radwan afify Hazem mohamed Mahmoud Hassan Biochemistry Department Faculty of AgricultureCairo University

Objective:To evaluate three flowers of Hibiscus rosa-sinensis(***-sinensis),Quisqualis indica(***) and Senna surattensis(***) for their antioxidant activity by different methods in addition to total phenolic,flavonoid and pigment ***:Antioxidant activity of water,ethanol and absolute ethanol extracts of three flowers; ***-sinensis,*** and *** was *** antioxidant activity was assessed by 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity,ferrous chelating activity,reducing power,nitric oxide scavenging activity,hydroxyl radical scavenging activity as well as total antioxidant *** flavonoids,total phenols and total pigments including chlorophylls and carotenoids were measured for the three ***:The results showed that the highest total antioxidant capacity at concentration of 500 mg/L was found in *** as 0.479 ± *** activity of ***,*** and *** flower extracts against 1,1-diphenyl-2-picrylhydrazyl radical showed the highest activity of(90.20 ± 0.29)% with 500 mg/*** screening of the three flowers extracts were carried out for alkaloids,flavonoids,saponins,tannins,steroids,glycosides,terpenoids,amino acid and ***-sinensis showed the total phenolic in water extract of(235.77 ± 14.31) mg/100 g,the other two flowers *** and *** had the total phenolic in ethanol extracts of(937.70 ± 25.06) and(850.30 ± 13.81) mg/100 g,*** the other hand total flavonoids were identified in absolute ethanol extracts in the three flowers[(32.83 ± 1.34),(49.24 ± 4.87) and(2.79 ± 0.23) mg/100 g,respectively].Conclusions:The extracts in the constituents of the three flowers could be used as additives as supplement fractions in foods.

关键词： Free radical Antioxidant Hibiscus rosa-sinensis Quisqualis indica Senna surattensis

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Formulation and evaluation of anti-asthmatic drug montelukast in mucoadhesive buccal patches

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Journal of Coastal Life Medicine 2014年第11期 907-914页

作者： Magdy Ibrahim mohamed Enas abd el-moneim mohamed radwan afify Mary Kamal Gad Mekhael Department of Pharmaceutics Faculty of PharmacyCairo UniversityCairoEgypt National Organization for Drug Control and Research DokyGizaEgypt

Objective: To formulate and evaluate anti-asthmatic drug montelukast in mucoadhesive buccal patches. Methods:Buccal patches were formulated by using different hydrophilic polymers by solvent casting technique. Buccal patches were evaluated by seven physical appearances, in addition toin vitro drug release study. Results: All patches were uniform and translucent, and had smooth surface. In vitro release studies were conducted for montelukast buccal patches proved that release in the range of 75.26%-92.30% in 8 h. Emission of montelukast from all patches simulated zero order and diffusion mechanism. Finally it can be concluded that F3, F15 and F16 are the best formulation. Conclusions: The investigation concluded that patch of 5 mg of montelukast sodium were formulated by using sodium alginate with sodium carboxy methyl cellulose, hydroxy propyl methyl cellulose K100M with sodium carboxy methyl cellulose, and hydroxy propyl methyl cellulose K100M with sodium alginate (F3, F15 and F16 formulations) were the best formulations.

关键词： Montelukast sodium Gelatin Hydroxy propyl methyl cellulose Poly vinyl pyrrolidone Buccal film In-vitro release

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Wear properties of copper and copper composites powders consolidated by high-pressure torsion

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Friction 2020年第2期8卷 433-450页

作者： mohamed Ibrahim abd el AAL Mechanical Engineering Department College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addawaser 11991Saudi Arabia Mechanical Design&Production Department Faculty of EngineeringZagazig UniversityZagazig 44519Egypt

The wear characteristics of Cu and Cu-SiC composite microsize powders consolidated by cold compaction combined with sintering or high-pressure torsion(HPT)were *** HPT processed(HPTed)samples with bimodal and trimodal microstructures and fine Cu grains and SiC particle sizes have superior hardness,reasonable ductility level,and high wear *** wear mass loss and coefficient of friction of HPTed samples were remarkably lower than that of cold-compacted and sintered samples as well as that of micro and nano Cu and Cu-SiC composites from previous *** sample fabrication method has an apparent influence on the wear *** wear mechanism was converted from adhesive,delamination,three-body mechanism,grooves(take off the SiC particles),and cracks into abrasive wear after *** can be considered a dominant wear mechanism in all *** worn surface morphology and analysis support the relationship between wear mechanism and characteristics.

关键词： Cu-SiC composite powders high-pressure torsion(HPT) fine and coarse grains wear characteristics worn surface morphology

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Effect of different metal sulfate precursors on structural and catalytic performance of zirconia in dehydration of methanol to dimethyl ether

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燃料化学学报 2018年第1期46卷 67-74页

作者： abd el-Aziz A.Said mohamed abd el-Aal Chemistry Department Faculty of ScienceAssiut University71516 AssiutEgypt

ZrO_2 was treated with 10% SO_4^(2-) from different metal sulfate precursors for methanol dehydration to dimethyl *** the samples exhibited tetragonal phase and no diffraction peaks corresponding to metal sulfates or metal oxides were *** FT-IR results revealed that there were different interactions between sulfate and ZrO_2,and this had a great effect on the surface area of the *** catalytic activity was measured over the catalysts in the temperature range of 100-300 ℃.The results revealed that sulfated zirconia with CuSO_4·5 H_2O and Al_2(SO_4)_3·16 H_2O showed the best catalytic *** maximum yield of DME ≈87% was obtained over CuSZ at a reaction temperature of 275 ℃.Moreover,the catalytic activity of the catalysts was correlated well with their surface acidity that measured by dehydration of isopropanol.

关键词： MSO 4/ZrO2 甲醇脱水 DME

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Ore Controls and Metallogenesis of Au-Ag Deposits at Atalla Mine,Central Eastern Desert of Egypt

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Acta Geologica Sinica(English Edition) 2020年第5期94卷 1451-1470页

作者： mohamed abd el MONSEF Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt Institute of Geological Sciences Faculty of ScienceMasaryk UniversityBrnoCzech Republic

Gold-silver deposits in the Atalla area occur as hydrothermal quartz veins in NE–SW pre-existing fractures within the Atalla granitic *** orientation of such quartz veins has been attributed to extensional behavior related to the Atalla Shear Zone(ASZ).The Atalla area is covered by a variety of lithologies that are(from oldest to youngest):metasedimentary rocks,metavolcanic rocks,ophiolite assemblage(serpentinites/talc-carbonates),Atalla granite and Dokhan volcanic ***,Atalla granite ranges in composition from granodiorite to *** geochemistry constrains the calc-alkaine affinity of the Atalla granite that was intruded within an orogenic(syncollision)tectonic *** ore minerals are represented by gold/silver(electrum),pyrite(Py1&Py2),arsenopyrite,pyrrhotite,sphalerite,chalcopyrite,galena,covellite and *** temperature of ore formation ranges from 240 to 285℃and the estimated fluid pressure is in the range of 20–100 *** on the geological setting,ore textures and fluid characteristics;the Atalla Au-Ag deposits are considered to be orogenic in nature,formed from a continental collision(~653-590 Ma),synchronous with the emplacement of calc-alkaline magmatism during the evolutionary history of the Arabian Nubian Shield(ANS).The initial ore-forming fluid was primarily derived from a metamorphic source related to ophiolitic-serpentinite rocks under deep regional conditions of greenschist-amphibolite facies,where the Atalla granitic eruption provided the required temperature conditions for the metamorphic process to take *** such conditions,the transportation of ore metals as bisulfide complexes is *** deposition of ore minerals was triggered by fluidwallrock interaction through fracture pathways in conjunction with a temperature-pressure drop that is likely to have been related to uplift into the crustal levels.

关键词： Gold-silver arsenopyrite geothermometry fluid inclusions orogenic deposits Atalla Shear Zone(ASZ)

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Optimal searching for a Helix target motion

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Science China Mathematics 2015年第4期58卷 749-762页

作者： mohamed abd Allah el-Hadidy Department of Mathematics Faculty of Science Tanta University

This paper discusses a search problem for a Helix target motion in which any information of the target position is not available to the searchers. There exist three searchers start searching for the target from the origin. The purpose of this paper is to formulate a search model and finds the conditions under which the expected value of the first meeting time between one of the searchers and the target is finite. Also, the existence of the optimal search plan that minimizes the expected value of the first meeting time is shown. Furthermore,this optimal search plan is found. The effectiveness of this method is illustrated by using an example with numerical results.

关键词： Helix motion optimal search plan first meeting time probability measure multiobjective nonlinear programming problem

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Neoproterozoic Tectonic Events of Egypt

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Acta Geologica Sinica(English Edition) 2021年第4期95卷 1366-1405页

作者： mohamed abd el-WAHED Zakaria HAMIMI Geology Department Faculty of ScienceTanta UniversityTanta 31527Egypt Department of Geology Faulty of ScienceBen ha UniversityBenha 13518Egypt

The Egyptian Nubian Shield(ENS)represents the northwestern part of the Arabian-Nubian Shield and the northern extension of the East African *** ENS is regarded as being formed due to northward-directed escape *** is characterized by mild accretion and suture zones dominated by major strike-slip zones with a commonly sinistral sense of movement;some shear zones display a dextral sense of *** is dominated by gneisses and migmatites in the south,arc volcaniclastic metasediments and highly dismembered ophiolites in the central parts,whereas its northern part is dominated by late-to post-tectonic *** southern Sinai,the Neoproterozoic rocks are grouped into four complexes,namely Feiran–Solaf,Sa’al–Zaghra,Kid and *** ENS ophiolites were formed between 730–750 Ma,mainly in a supra-subduction zone *** ENS has undergone a Neoproterozoic deformation history involving three successive phases:(1)Early N–S shortening phase(D1),(2)Syn-accretionary phase(D2)and(3)Post-accretionary phase(D3).The initial island-arc stage(780–730 Ma)is a N–S shortening phase initiated by collision between the Eastern Desert tectonic terrane to the north with both the Gebeit and Gabgaba terranes to the south(830–720 Ma).During the arc-splitting and back-arc spreading stage(730–620),voluminous syn-tectonic granitoids intruded into the ENS(750–610 Ma).The E–W-directed compressional/transpressional phase(620–450 Ma)led to the overall uplift of the central part of the ENS and consequently the development and exhumation of the core complexes in oblique convergent *** E–W intense shortening deformation resulted also in the formation of NW-and NE-striking sinistral and dextral strike-slip shear zones,*** latest periods of the E–W-directed compressional/transpressional regime were characterized by deposition of the molasse-type Hammamat Sediments unconformably over the Dokhan Volcanics,or interbedded with *** combined thrusting,folding and sin

关键词： Neoproterozoic deformation N–S shortening syn-accretionary phase post-accretionary phase Egyptian Nubian Shield

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Magnetoresistive properties of Ni-doped La_(0.7)Sr_(0.3)MnO_3 manganites

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Rare Metals 2016年第7期35卷 551-558页

作者： Ahmed mohamed Ahmed abd el-Moez Ahmed mohamed Medhat abdelrady abdellateef Hassan Ahmed abd el-Ghanny Physics Department Faculty of ScienceSohag University

Lao.7Sr0.3Mnl_xNixO3 （x = 0, 0.025, 0.050 and 0.075） ceramics were prepared by the conventional solid-state reaction method. The partial substitution of Mn by Ni2＋ leads to a decrease in cell volume as well as a structural transition from the rhombohedral to the orthorhombic structure. Ni2＋ doping increases the electrical resistivity, decreases the semiconductor-metal transition temperature （Tms） and relatively enhances the room temperature magnetoresistance （MR）, especially in x = 0.025 and around Tins. With respect to conduction mechanism, the small polaron hopping （SPH） and the variable range hopping （VRH） models were used to ex- amine conduction in the semiconducting region.

关键词： Manganites X-ray diffraction Structure electrical resistivity Magnetoresistance

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Entropy Generation for Flow and Heat Transfer of Sisko-Fluid Over an Exponentially Stretching Surface

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Computers, Materials & Continua 2020年第1期62卷 37-59页

作者： mohamed abd el-Aziz A.M.Aly Department of Mathematics Faculty of ScienceKing Khalid UniversityAbha61411Saudi Arabia Department of Mathematics Faculty of ScienceHelwan UniversityHelwan-Cairo11795Egypt Department of Mathematics Faculty of ScienceSouth Valley UniversityQena83523Egypt

In the present study,the effects of the magnetic field on the entropy generation during fluid flow and heat transfer of a Sisko-fluid over an exponentially stretching surface are *** similarity transformations are used to transfer the governing partial differential equations into a set of nonlinear-coupled ordinary differential ***-Kutta-Fehlberg method is used to solve the governing *** effects of magnetic field parameter,local slip parameterλ,generalized Biot numberγ,Sisko fluid material parameter,Eckert number Ec,Prandtl number Pr and Brinkman number Br at two values of power law index on the velocity,temperature,local entropy generation number N_(G) and Bejan number Be are ***,the tabular forms for local skin friction coefficient and local Nusselt number under the effects of the physical parameters are *** current results are helpful in checking the entropy generation for *** is found that,an extra magnetic field parameter makes higher Lorentz force that suppresses the *** shear thinning fluids(nelocity *** entropy generation number is more for larger generalized Biot number,magnetic field parameter and Brinkman *** local skin friction coefficient increases as magnetic field parameter and material parameter are increase and it decreases as local slip parameter *** local Nusselt number decreases as magnetic field parameter,local slip parameter and Eckert number are increase,while it increases as material parameter,generalized Biot number and Prandtl number are increase.

关键词： Boundary layer entropy generation exponentially stretching surface magnetic field sisko-fluid

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MHD Boundary Layer Flow of a Power-Law Nanofluid Containing Gyrotactic Microorganisms Over an Exponentially Stretching Surface

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Computers, Materials & Continua 2020年第2期62卷 525-549页

This study focusses on the numerical investigations of boundary layer flow for magnetohydrodynamic(MHD)and a power-law nanofluid containing gyrotactic microorganisms on an exponentially stretching surface with zero nanoparticle mass flux and convective *** nonlinear system of the governing equations is transformed and solved by Runge-Kutta-Fehlberg *** impacts of the transverse magnetic field,bioconvection parameters,Lewis number,nanofluid parameters,Prandtl number and power-law index on the velocity,temperature,nanoparticle volume fraction,density of motile microorganism profiles is *** addition,the impacts of these parameters on local skin-friction coefficient,local Nusselt,local Sherwood numbers and local density number of the motile microorganisms are *** results reveal that the power law index is considered an important factor in this *** to neglecting the buoyancy force term,the bioconvection and nanofluid parameters have slight effects on the velocity *** resultant Lorentz force,from increasing the magnetic field parameter,try to decrease the velocity profiles and increase the rescaled density of motile microorganisms,temperature and nanoparticle volume fraction ***,an augmentation of power-law index drops the reduced local skin-friction and reduced Sherwood number,while it increases reduced Nusselt number and reduced local density number of motile microorganisms.

关键词： Bioconvection gyrotactic microorganisms magnetohydrodynamic nanofluid boundary layer power-law

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