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Effect of Conductive Fillers on the Cyclic Stress-Strain and Nano-Scale Free Volume Properties of Silicone Rubber

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Chinese Journal of Polymer Science 2014年第5期32卷 558-567页

作者： m.H.Abd-el Salam S.el-Gamal m.mohsen D.m.Abd el-maqsoud Physics Department Faculty of Education Ain Shams University Physics Department Faculty of Science Ain Shams University

The effect of carbon black （CB） and graphite （G） powders on the macroscopic and nano-scale free volume properties of silicone rubber based on poly（di-methylsiloxane）（PDmS） was studied through thermal and cyclic mechanical measurements, as well as with positron annihilation lifetime spectroscopy （PALS）. The melting temperature of the composites （Tm） and the endothermic enthalpy of melting （ΔHm） were estimated by differential scanning calorimetry （DSC）. Tm and the degree of crystallinity （χc） of PDmS composites were found to decrease with increasing the CB content. This can be explained due to the increase in physical cross-linking which results in a decrease in the crystallite thickness. Besides, χc was found to be dependent on the filler type. Cyclic stress-strain behavior of PDmS loaded with different contents of filler has been studied. mullins ratio （Rm） was found to be dependent on the filler type and content. It was found that, Rm increases with increasing the filler content due to the increase in physical cross-linking which results in a decrease in the size of free volume, as observed through a decrease of the o-Ps lifetime τ3 measured by PALS. moreover, the hysteresis in PDmS-CB composites was more pronounced than in PDmS-G composites. Furthermore, a correlation was established between the free volume Vf and the mechanical properties of PDmS composites containing different fillers. A negative correlation was observed between Vf and Rm.

关键词： Positron annihilation Positronium Free volume Si-rubber Composite Cyclic mechanical properties.

Effect of Ca addition on modification of primary mg_(2)Si,hardness and wear behavior in mg-Si hypereutectic alloys

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Journal of magnesium and Alloys 2014年第3期2卷 230-238页

作者： m.E.moussa m.A.Waly a.m.el-Sheikh Department of manufacturing Technology Laboratory of FoundryCentral Metallurgical Research and Development Institute(CMRDI)P.O.87HalwanEgypt Department of mining Petroleum and Metallurgical EngineeringFaculty of EngineeringCairo UniversityP.O.12613GizaEgypt

The effect of Ca addition on modification of primary mg_(2)Si,hardness and wear behavior in mg-5 wt.%Si hypereutectic alloy has been *** results showed clearly that without Ca addition,most of primary mg_(2)Si appeared as coarse dendritic morphology with average size of about 215μ*** the addition of 0.1 wt.%Ca,the average size of primary mg_(2)Si decreased to about 98μm,but their morphologies did not significantly *** the addition level of Ca increased to 0.3 wt.%,the average size of primary mg_(2)Si decreased significantly to about 50μm and their morphologies changed to polyhedral ***,with further increasing Ca addition to 0.6 wt.%and 1 wt.%,some needle-like and blocky CamgSi particles formed and the average size of primary mg_(2)Si increased slightly,which could described as *** present work showed that the optimal modification effect could be obtained when the Ca content in the investigated alloy reached 0.3 wt.%.The modification mechanism may be referred mainly due to poisoning effect resulting from the segregation of Ca atoms at the growth front of the mg_(2)Si and the adsorption effect of some Ca atoms in the mg_(2)Si crystal growth *** 0.3 wt.%Ca-added alloy has the highest hardness value and the best wear resistance among all other *** excessive Ca addition resulted in the formation of some needle-like and blocky CamgSi particles,which was detrimental to hardness and wear behavior of the 0.6 wt.%and 1 wt.%Ca-added *** wear mechanism of investigated alloys is a mild abrasive oxidative wear with little adhesion.

关键词： mg-Si alloys modification Ca addition Hardness Wear

Petrology, geochemistry, radioactivity, and m–W type rare earth element tetrads of el Sela altered granites, south eastern desert,Egypt

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Acta Geochimica 2019年第1期38卷 95-119页

作者： a.m.el mezayen m.A.Heikal m.G.el-Feky H.A.Shahin I.K.Abu Zeid S.R.Lasheen Geology Department Faculty of Science Al Azhar University Nuclear material Authority

The southern part of the Eastern Desert of Egypt—about 30 km southwest of Abu-Ramad city—is mainly covered by ophiolitic rocks(Sul Hamed), island arc assemblage, younger granites(muscovite granites of Qash Amer and two mica granites of el Sela), and various acidic and basic dikes. Field, petrological, and geochemical studies indicate that the el Sela shear zone has been subject to hydrothermal and supergene alteration such as kaolinization, albitization, sericitization, and hematitization. It is invaded by quartz ENE–WSW veins associated with hydrothermal alteration accompanied by radioactive mineralization. The investigated younger granitic rocks had very low contents of compatible elements, such as Cr, Ni,and Co; and high contents of incompatible elements, such as Zr, and large ion lithophiles, such as Sr, especially in the el Sela shear zone. major oxide and trace element analyses revealed calc-alkaline affinity and peraluminous *** highly differentiated granitic rocks' lower Zr/Hf and higher Y/Ho than the normal ratio are consistent with hydrothermal alteration. most samples had rare earth element(REE)-patterns with an m-type tetrad effect in the first and fourth segments and a W-type tetrad in the third segment. The average ∑REE in the studied granites was lower than the world granite average; the ratio of light to heavy REEs greater. The main radioactive, uranium-bearing, and uraniferous Fe and mn minerals are uranothorite,autunite, uranophane and autunite as compounds, kasolite,columbite, xenotime, uranophane-bearing zircon and jarosite, silver-bearing pyrite, hematite, and autunite-bearing pyrolusite.

关键词： Geochemistry REE-tetrad effect Radioactive minerals Radiometric measurements Qash Amer el Sela

Synthesis, in vitro antitumor activity and molecular modeling studies of a new series of benzothiazole Schiff bases

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Chinese Chemical Letters 2016年第3期27卷 380-386页

作者： moustafa T.Gabr Nadia S.el-Gohary Eman R.el-bendary mohamed m.el-Kerdawy Nanting Ni Department of medicinal Chemistry Faculty of Pharmacy Mansoura University Mansoura 35516 Egypt Department of Chemistry Ceorgia State University Atlanta CA 30303 USA

A new series of benzothiazole Schiff bases 3–29 was synthesized and screened for antitumor activity against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that compounds 3, 14, 19, 27 and 28 have promising activity against Hela cell line with IC50 values of 2.41,3.06, 6.46, 2.22 and 6.25 mmol/L, respectively, in comparison to doxorubicin as a reference antitumor agent（IC50 2.05 mmol/L）. In addition, compound 3 displayed excellent activity against COS-7 cell line with IC50 value of 4.31 mmol/L in comparison to doxorubicin（IC50 3.04 mmol/L）. In the present work,structure based pharmacophore mapping, molecular docking, protein-ligand interaction, fingerprints and binding energy calculations were employed in a virtual screening strategy to identify the interaction between the compounds and the active site of the putative target, EGFR tyrosine kinase. molecular properties, toxicity, drug-likeness, and drug score profiles of compounds 3, 14, 19, 27, 28 and 29 were also assessed.

关键词： Benzothiazole Schiff bases Antitumor activity molecular modeling In silico studies

Changing dietary n-6:n-3 ratio using different oil sources affects performance,behavior,cytokines mRNA expression and meat fatty acid profile of broiler chickens

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Animal Nutrition 2018年第1期4卷 -页

作者： Doaa Ibrahim Rania el-Sayed Safaa I.Khater Enas N.Said Shefaa a.m.el-mandrawy Department of Nutrition and Clinical Nutrition Faculty of Veterinary MedicineZagazig University Department of Biochemistry Faculty of Veterinary MedicineZagazig University Department of Veterinary Public Health Faculty of Veterinary MedicineZagazig University Department of Clinical Pathology Faculty of Veterinary MedicineZagazig University

Typical formulated broiler diets are deficient in n-3 poly-unsaturated fatty acids(PUFA) due to widening n-6:n-3 PUFA ratio which could greatly affect performance,immune system of birds and,more importantly,meat *** study was conducted to evaluate the effect of modifying dietary n-6:n-3 PUFA ratio from plant and animal oil sources on performance,behavior,cytokine m RNA expression,antioxidative status and meat fatty acid profile of broiler ***(n=420) were fed 7 diets enriched with different dietary oil sources and ratios as follows: sunflower oil in control diet(C); fish oil(FO); 1:1 ratio of sunflower oil to FO(C1 FO1); 3:1 ratio of sunflower oil to fish oil(C3 FO1); linseed oil(LO); 1:1 ratio of sunflower oil to linseed oil(C1 LO1); 3:1 ratio of sunflower oil to linseed oil(C3 LO1),resulting in dietary n-6:n-3 ratios of approximately 40:1,1.5:1,4:1,8:1,1:1,2.5:1 and 5:1,*** best final body weight,feed conversion ratio as well as protein efficiency ratio of broilers were recorded in the C1 FO1 and C1 LO1 *** with the control group,the dressing percentage and breast and thigh yield were highest in the C1 FO1 and C1 LO1 *** the dietary n-6:n-3 ratio increased(P meat contents of eicosapentaenoic acid and docosahexaenoic acid increased(P m FO and LO clearly decreased(P m total cholesterol,triglycerides and very low-density lipoproteins and enhanced antioxidative *** feeding frequency was decreased(P mpared to plant oil,to broiler diets enhanced the relative m RNA expression of interferon gamma,interleukin-1 beta,interleukin-2 and

关键词： Broiler n-6:n-3 PUFA ratio Performance Antioxidant status meat Immunity

Solid Waste management:A mADm Approach Using Fuzzy Parameterized Possibility Single-Valued Neutrosophic Hypersoft Expert Settings

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Computer modeling in Engineering & Sciences 2025年第1期142卷 531-553页

作者： Tmader Alballa muhammad Ihsan Atiqe Ur Rahman Noorah Ayed Alsorayea Hamiden Abd el-Wahed Khalifa Department of mathematics College of SciencesPrincess Nourah bint Abdulrahman UniversityRiyadh11671Saudi Arabia 2 Department of mathematics University of Management and TechnologyLahore54000Pakistan Department of mathematics College of ScienceQassim UniversityBuraydah51452Saudi Arabia

The dramatic rise in the number of people living in cities has made many environmental and social problems *** search for a productive method for disposing of solid waste is the most notable of these *** scholars have referred to it as a fuzzy multi-attribute or multi-criteria decision-making problem using various fuzzy set-like approaches because of the inclusion of criteria and anticipated *** goal of the current study is to use an innovative methodology to address the expected uncertainties in the problem of solid waste site *** characteristics(or sub-attributes)that decision-makers select and the degree of approximation they accept for various options can both be indicators of these *** tackle these problems,a novel mathematical structure known as the fuzzy parameterized possibility single valued neutrosophic hypersoft expert set(ρˆ-set),which is initially described,is integrated with a modified version of Sanchez’s *** this,an intelligent algorithm is *** steps of the suggested algorithm are explained with an example that explains *** compatibility of solid waste management sites and systems is discussed,and rankings are established along with detailed justifications for their *** study’s strengths lie in its application of fuzzy parameterization and possibility grading to effectively handle the uncertainties embodied in the parameters’nature and alternative approximations,*** uses specific mathematical formulations to compute the fuzzy parameterized degrees and possibility grades that are missing from the prior *** is simpler for the decisionmakers to look at each option separately because the decision is *** the computed results,it is discovered that they are consistent and dependable because of their preferred properties.

关键词： Hypersoft expert set Sanchez’s method decision making optimization solid waste management possibility grade fuzzy parameterization

Geochemistry, mineralogy, and radioactivity of the Abu Furad Area, Central Eastern Desert, Egypt

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Acta Geochimica 2019年第2期38卷 307-326页

作者： a.m.el mezayen E.K.Abu Zeid W.S.Hosny m.G.el-Feky S.m.Omar S.A.Taalab Geology Department Faculty of Science Al Azhar University Nuclear material Authority Cairo Egypt

Abu Furad is in the Central Eastern Desert,Egypt. It comprises metasediments, metavolcanics,metagabbros, syn-to late-orogenic granites, and post-orogenic granites, in addition to numerous dykes and veins of different shapes and composition invading all the older rocks cropping out in the study area. Field, petrographic,mineralogical, and chemical investigations led to the classification of Abu Furad granites as quartz diorite, tonalite,granodiorite, and *** oxide and trace element data revealed that the syn-to late-orogenic granites and post-orogenic granites are peraluminous. Syn-to lateorogenic granites originated from calc-alkaline volcanic arc–related magma; while the post-orogenic granites(syenogranite) are highly fractionated, calc-alkaline granite from a within plate regime. Radiometrically, the studied quartz diorite, tonalite, and granodiorite had lower uranium and thorium contents and higher eU/eTh ratios than the syenogranites. This may indicate that the syn-to late-orogenic rocks originated from sources depleted in these elements. The average e Th/eU ratio of syenogranites was higher than that of average continental crust, suggesting that the syenogranites are relatively depleted in U. The studied altered syenogranites were strongly enriched in U and Th compared to the Earth's crust. On the other hand, the average of e U in pegmatites is lower than the global average for uraniferous pegmatites. The most recorded accessory minerals in the altered syenogranites were thorite, fergusonite, samarskite, columbite, zircon, monazite, xenotime,apatite, fluorite, sphene, atacamite, and malachite, in addition to chromium and nickel inclusions.

关键词： Hydrothermal alterations major oxide and trace elements Radiometry mineralogy Geochemistry Altered syenogranites Egypt

Estimation of radiation hazard indices from natural radioactivity of some rocks

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Nuclear Science and Techniques 2006年第2期17卷 118-122页

作者： A.ABBADY N.K.AHmED a.m.el-ARABI R.mICHel A.H.el-KAmel A.G.E.ABBADY Physics Department Faculty of Science Qena South Valley University Egypt Institute of the Radiation Protection and Radioecology Hannover University Germany Physics Department Faculty of Science Assiut University Egypt

Different samples of igneous and metamorphic rocks from Egypt and Germany have been considered to measure γ-ray activity concentrations due to naturally occurring, potentially hazardous radonuclides 226Ra, 232Th and 40K. The radiation hazard parameters including radiation equivalent activity, gamma-absorbed dose rate, and exter- nal and internal hazard indices have been estimated. The gamma-absorbed dose rates in air of rocks in Egypt range from 4.2 to 128.5 nGy·h-1 with a mean value of 55.3 nGy·h-1. For igneous and metamorphic rocks from Germany, the values of absorbed dose rates fluctuate from 5.1 to 148.6 nGy·h-1, with a mean value of 60.9 nGy·h-1. Generally, it is found that the radiation hazard indices in common igneous rocks are distinctly higher in acidic than in ultrabasic rocks. The results are discussed and compared with the corresponding published data.

关键词：自然放射性岩石变质岩环境放射学

Synthesis,antimicrobial, antiquorum-sensing and cytotoxic activities of new series of benzothiazole derivatives

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Chinese Chemical Letters 2015年第12期26卷 1522-1528页

作者： moustafa T.Gabr Nadia S.el-Gohary Eman R.el-bendary mohamed m.el-Kerdawy Nanting Ni mona I.Shaaban Department of medicinal Chemistry Faculty of Pharmacy Mansoura University Department of Chemistry Georgia State University Department of microbiology Faculty of Pharmacy Mansoura University Department of microbiology College of Pharmacy Taibah University

New series of benzothiazole derivatives were designed and synthesized. The newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus. Compounds 6j and 6o showed the highest activity against E. coli and S. aureus. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus fumigatus293. Compounds 4c, 4g and 6j exhibited the highest activity against C. albicans. In addition, compounds4 a and 6j displayed promising activity against A. fumigatus 293. The same compounds were examined for their antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, whereas compounds4 a, 6j and 6p showed moderate activity. The in vitro cytotoxicity testing of the synthesized compounds was performed against cervical cancer（Hela） and kidney fibroblast cancer（COS-7） cell lines. Results indicated that all tested compounds have IC50 values 〉50 mmol/L against both cell lines. molecular properties, toxicities, drug-likeness, and drug score profiles of compounds 4a–c, 5a, 6g,h, 6j, 6l, 6o and7 c,d were also assessed.

关键词： antibacterial moiety antifungal antimicrobial cytotoxic screened moderate substituent Candida albicans