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Journal of Materials Science & Technology 2005年第5期21卷 675-680页

作者： M.H.Khedr A.A.Farghali Chemistry department Faculty of Science(Beni-Suef Branch)Cairo UniversityBeni-Suef EgyptChemistry DepartmentFaculty of Science(Beni-Suef Branch)Cairo UniversityBeni-Suef Egypt

Copper ferrite, CuFe2O4, one of the important ferrites due to its interesting electrical, magnetic and structural properties, is obtained by a novel self flash combustion of a homogeneous mixture of one mole copper acetate monohydrate, Cu（CH3COO）2·H2O, and two moles of iron （Ⅲ） acetate basic, Fe（CHCOO）2·OH. Nanocrystalite （89 nm） Copper ferrite （less than 100%） is obtained at lower temperatures, whereas 100% copper ferrite is obtained after calcination at 1000℃. Thermal analysis （TG and DTA）, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR）, photo microscopy, magnetic and porosity obtained after calcinations at 700, 800, 900 and 1000℃ to measurements have been carried out for the specimens characterize the conversion efficiency of the powder precursors to copper ferrite. It was found that increasing temperature leads to great improvement in the magnetic properties. By increasing calcination temperature from 700～1000℃saturation magnetic flux density （Bs） increased from 17.8 to 40.8 emu/g, while remnant magnetic flux density （Br） increased from 10.1 to 17.11 emu/g.

关键词： Copper ferrite Flash combustion Synthesis Characterization Magnetic properties Microstructure

Development of Sulfuric Acid Speleogenetic Deposits within Cavernous Middle Eocene Beds:Inference on Hydrocarbon Gas Seepages,Giza Pyramids Plateau,Egypt

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Acta Geologica Sinica(English Edition) 2021年第3期95卷 946-961页

作者： Hanan S.BADAWY Geology department Faculty of ScienceBeni-Suef UniversityBeni-SuefEgypt

Development of sulfuric acid speleogenetic mineral deposits within cavernous middle Eocene beds of the Pyramids plateau is linked to hydrocarbon gas *** work carried out field observations,binocular,polarizing,scanning and transmitted electron microscopy investigation,X-ray diffraction and X-ray fluorescence *** morphological and petrographic features and chemical composition of the studied mineral deposits reveal a hypogene sulfuric acid speleogenesis.A model comprised of the following stages can be used to explain the presence of these features.(1)Ascent of hydrogen sulfide(H_(2)S)gas associated with hydrocarbon seepages from the Cretaceous reservoirs under reducing conditions followed by oxidation to sulfuric acid(H_(2)SO_(4)),(2)descent of carbonic acid(H_(2)CO_(3))-rich solution generated from surface sources,(3)reaction of H_(2)SO_(4)and H_(2)CO_(3)with the calcareous and argillaceous host rocks,(4)formation of H_(2)SO_(4)speleogenetic by-products represented by natroalunite,aluminium-phosphate-sulfate,hydrated halloysite and Fe/Mn oxides within the replacive gypsum,and(5)subsequent stresses due to the formation of nearby stratiform cavities gave rise to the development of fractures/veinlets filled with displacive fibrous satinspar *** study sets the paleokarst features of the Giza Pyramids plateau within a hypogene sulfuric acid karst system developed by the action of groundwater containing H_(2)S,H_(2)SO_(4)and H_(2)CO_(3).

关键词： karstification natroalunite aluminium-phosphate-sulfate hydrated halloysite enterolithic growth satinspar gypsum

Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

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Chinese Physics B 2016年第11期25卷 333-339页

作者： Arafa H Aly Ahmed Mehaney Physics department Faculty of Sciences Beni-Suef University

This study reports on the propagation of elastic waves in 1D and 2D mass spring *** analytical and computation model is presented for the 1D and 2D mass spring systems with different *** enhancement in the band gap values was obtained by modeling the structures to obtain low frequency band gaps at small ***,the evolution of the band gap as a function of mass value is *** attention is devoted to the local resonance property in frequency ranges within the gaps in the band structure for the corresponding infinite periodic lattice in the 1D and 2D mass spring system.A linear defect formed of a row of specific masses produces an elastic waveguide that transmits at the narrow pass band *** frequency of the waveguides can be selected by adjusting the mass and stiffness coefficients of the materials constituting the ***,we pay more attention to analyze the wave multiplexer and DE-multiplexer in the 2D mass spring *** show that two of these tunable waveguides with alternating materials can be employed to filter and separate specific frequencies from a broad band input *** presented simulation data is validated through comparison with the published research,and can be extended in the development of resonators and MEMS verification.

关键词： multiplexing waveguide tunable separate dimensions devoted verification stiffness validated infinite

Finite Groups with Certain S-Permutable and GS-Maximal Subgroups

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Algebra Colloquium 2020年第4期27卷 661-668页

作者： A.M.Elkholy M.H.Abd-Ellatif department of Mathematics and Computer Science Faculty of Science Beni-Suef University62511 Beni-SuefEgypt

Let G be a finite group and H a subgroup of *** say that H is S-permutable in G if H permutes with every Sylow subgroup of G.A group G is called a generalized smooth group(GS-group)if[G/L]is totally smooth for every subgroup L of G of prime *** this paper,we investigate the structure of G under the assumption that each subgroup of prime order is S-permutable if the maximal subgroups of G are GS-groups.

关键词： smooth groups subgroup lattices S-permutability

Rudists(Bivalvia) from a Cretaceous Platform in Northern Egypt: Taxonomy and Paleobiogeography

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Acta Geologica Sinica(English Edition) 2021年第6期95卷 1967-1983页

作者： Yasser SALAMA Jamaan S.AJAREM Ahmed A.ALLAM Ahmed M.ALMALKI Geology department Faculty of ScienceBeni-suef UniversityBeni-suef 65211Egypt department of Zoology College of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia department of Zoology Faculty of ScienceBeni-suef UniversityBeni-suef 65211Egypt

New well-preserved rudist materials come from the Barremian–Turonian marine formations in the Yelleg, Minsherah, Maaza, and Raghawi sections in North Sinai, northern Egypt. There, 17 discovered rudist species belonging to 13 genera and seven taxonomic families are described in detail as follows: Eoradiolites plicatus(Conrad), Eoradiolites liratus(Conrad), Praeradiolites ponsianus(d'Archiac), Archaeoradiolites sp., Bournonia africana Douvillé, Bournonia fourtaui Douville, Biradiolites lombricalis(d'Orbigny), Biradiolites zumoffeni Douville, Radiolites lewyi lewyi Parnes, Radiolites sauvagesi(d'Hombres-Firmas), Durania arnaudi(Choffat), Toucasia carinata(Matheron), Toucasia sp., Neocaprina raghawiensis Steuber and Bachmann, Sellaea sp., Ichthyosarcolites sp. and Horoiopleura sp.. The Cenomanian deposits in the northern Eastern desert of Egypt only contain E. liratus. The domination of the Cenomanian rudist species in North Sinai, however, is attributed to changes in the platform, which passes mainly from carbonate in the north to siliciclastics in the south. The presence of Horiopleura sp. in the late Barremian-early Aptian deposits is documented for the first time, which suggests the expansion of taxa of the genus Horiopleura Douville to North Sinai during this interval. The age of the rudist species is documented from the late Barremian-Turonian formations, with their geographic distribution in the Mediterranean region considered..

关键词： invertebrate paleontology mollusks rudists Taxonomy Paleobiogeography Barremian–Turonian Egypt

Influence of temperature on the properties of one-dimensional piezoelectric phononic crystals

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Chinese Physics B 2018年第9期27卷 342-345页

作者： Ahmed Nagaty Ahmed Mehaney Arafa H Aly Physics department Faculty of Sciences Beni-Suef University

The current study investigates the influence of temperature on a one-dimensional piezoelectric phononic crystal using tunable resonant frequencies. Analytical and numerical examples are introduced to emphasize the influence of temperature on the piezoelectric phononic crystals. It was observed that the transmission spectrum of a one-dimensional phononic crystal containing a piezoelectric material（0.7 PMN-0.3 PT） can be changed drastically by an increase in *** resonant peak can be shifted toward high or low frequencies by an increase or decrease in temperature, ***, we deduced that temperature can exhibit a large tuning in the phononic band gaps and in the local resonant frequencies depending on the presence of a piezoelectric material. Such result can enhance the harvesting energy from piezoelectric materials, especially those that are confined in a phononic crystal.

关键词： phononic crystals resonant modes piezoelectric material thermal properties and temperature

Preparation and characterization of (CeO2)x-(Fe2O3)1-x nanocomposites:reduction kinetics and hydrogen storage

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Rare Metals 2020年第3期39卷 218-229页

作者： Shimaa G.Sayed Waleed M.A.El Rouby Ahmed A.Farghali Materials Science and Nanotechnology department Faculty of Postgraduate Studies for Advanced Science(PSAS)Beni-Suef UniversityBeni Suef62511Egypt

A series of nanosized CeO2-Fe2O3 mixed-oxide nanocomposites with different Ce4+/Fe3+molar ratios were successfully prepared by a co-precipitation *** surface area increased with Fe2O3 content increasing up to 60 wt%in the ***,with further increase in Fe2O3 content,the surface area began to *** reduction processes of the CeO2-Fe2O3 nanocomposites were studied in a hydrogen atmosphere at 300-600℃.The reduction rates increased by increasing both the temperature and Fe2O3 content in the *** microstructure of the reduced composites at 500℃illustrated the presence of a considerable number of macro-and *** activation energy values were calculated which were in the range of 3.56-5.37 kJ mol-1 at the initial stages(up to 35%reduction)and 5.21-10.2 kJ·mol-1 at the final stages(up to 80%reduction)of *** rate-controlling mechanisms in both the initial and final reduction stages were determined,and the initial reaction stage was controlled by combined gaseous diffusion and interfacial chemical reaction mechanisms for all the composites except for pure CeO2,which was controlled by a chemical reaction *** final reaction stage was controlled by a gaseous diffusion mechanism for some composites,while for the others it was controlled by combined gaseous diffusion and interfacial chemical reaction *** hydrogen sorption properties of the nanocomposites were studied by pressure composition isotherms using a volumetric *** storage in the nanocomposites increased by increasing the temperature because of the formation of oxygen vacancies which enhance atomic H adsorption and function as strong adsorption sites forming more metal hydride covalent bonds.

关键词： CeO2-Fe2O3 nanocomposite Reduction kinetics Reduction mechanism Hydrogen storage Oxygen vacancies

Thermodynamics Properties of Mesoscopic Quantum Nanowire Devices

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Chinese Physics Letters 2007年第5期24卷 1339-1341页

作者： Attia A. AwadAlla Adel H. Phillips department of Physics Faculty of Science Beni-Suef University Beni-Suef Egypt department of Physics and department of Mathematics Faculty of Engineering Ain Shams University Egypt

We investigate the thermodynamics properties of mesoscopic quantum nanowire devices, such as the effect of electron-phonon relaxation time, Peltier coefficient, carrier concentration, frequency of this field, and channel width. The influence of time-varying fields on the transport through such device has been taken into consideration. This device is modelled as nanowires connecting to two reservoirs. The two-dimensional electron gas in a GaAs- AlGaAs heterojunction has a Fermi wave length which is a hundred times larger than that in a metal. The results show the oscillatory behaviour of dependence of the thermo power on frequency of the induced field. These results agree with the existing experiments and may be important for electronic nanodevices.

关键词： THERMOPOWER TRANSPORT

Thermal 9hot Noise through Boundary Roughness of Carbon Nanotube Quantum Dots

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Chinese Physics Letters 2011年第1期28卷 186-189页

作者： Attia A. Awadalla Adel H. Phillips department of Physics Faculty of Science Beni-Suef University Beni-Suef Egypt department of Engineering Physics and Mathematics Faculty of Engineering Ain Shams University Cairo Egypt

Thermal shot noise, thermal voltage and thermo power are studied through a carbon nanotube quantum dot coupled to two leads with random roughness of amplitude on each of the two boundaries, under the effect of microwave field, and magnetic field. The expressions for the thermal shot noise and thermal energy are deduced when the barrier strength and contact area are taken into consideration. A model for such mesoscopic devices is proposed as a carbon nanotube quantum dot coupled to two leads with random roughness of amplitude on each of the two boundaries. The results show oscillatory behaviors of the dependence of the thermal shot noise on the studied parameters. The thermopower oscillates with the variation of the contact area, and the peak heights decrease linearly with the contact area and increases with temperature. This trend of behavior is due to the interplay of the induced microwave photons and the tunneling rate through the side bands. This research is important for using a model as a high-frequency shot noise detector and the thermopower is sensitive to the energy dependence of the conductance.

关键词： Noise Energy Carbon Lead Carbonates Carbonation Models Boundaries Fields

Combinatory effect of hesperetin and mesenchymal stem cells on the deteriorated lipid profile,heart and kidney functions and antioxidant activity in STZ-induced diabetic rats

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BIOCELL 2020年第1期44卷 27-39页

作者： Osama M.AHMED Mohamed A.HASSAN Ablaa S.SALEH Experimental Obesity and Diabetes Research Lab(EODRL) Physiology DivisionZoology DepartmentFaculty of ScienceBeni-Suef UniversityPO 62521Beni-SuefEgypt Biochemistry department Faculty of ScienceBeni-Suef UniversityPO 62521Beni-SuefEgypt

This study aimed to assess the effect of hesperetin and/or bone marrow-derived mesenchymal stem cells(BM-MSCs)on disturbed lipid profile,heart and kidney functions,oxidative stress and antioxidant defense system in streptozotocin(STZ)-induced diabetic *** 1 diabetes mellitus(T1DM)was induced in male Wistar rats by injecting 40 mg/kg body weight(b.w.)STZ dissolved in citrate buffer(pH 4.5).The diabetic rats were treated with hesperetin orally administered at dose 20 mg/kg b.w.,BM-MSCs intravenously injected at a dose of 1 x 106 cells/rat/week and their combination for 6 *** diabetic rats exhibited lipid abnormalities manifested by elevated serum levels of total cholesterol,triglycerides,LDL-cholesterol and VLDL-cholesterol and lowered HDL-cholesterol as well as elevated liver cholesterol and triglycerides content in association with the resultant fasting and postprandial hyperglycemia and insulin *** heart function biomarkers including CK-MB,AST and LDH activities as well as levels of kidney function parameters,creatinine,and urea,were significantly raised in the serum of diabetic *** changes were concomitant with abnormal redox balance represented by elevated lipid peroxidation,decreased glutathione content,and suppressed antioxidant enzyme activities in both heart and kidney of diabetic *** previous deleterious alterations were significantly ameliorated after the treatment of diabetic rats with hesperetin and BM-MSCs singly or in combination;the treatment with hesperetin together with BM-MSCs was the most *** on these findings,it can be concluded that the use of hesperetin with BM-MSCs may have more additive therapeutic value than their uses singly in *** addition,the ameliorative effects of hesperetin and BM-MSCs on lipid profile and heart and kidney functions in diabetic rats may be mediated,at least in part,via their suppressive effects on oxidative stress and ameliorative effects on the antioxidant defense system

关键词： BM-MSCs Hesperetin Streptozotocin-induced diabetes