Browsing by Author "Hassan M."

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    Determination of the sensing characteristics of SiO2-Bi2O3-TiO2 system towards relative humidity
    (2018-01-01) Afify A.S.; Slavov S.S.; Mahmoud A.E.R.; Hassan M.; Ataalla M.; Staneva A.; Mohamed A.
    The aim of the present study is to determine the relative humidity (RH) sensing characteristics of the glass and glasscrystalline materials based on SiO2-Bi2O3-TiO2 system prepared by the melt quenching and controlled glass crystallization methods. Sensors were obtained by screen-printing of the prepared compositions onto alumina substrates with Pt electrodes. The sensors were tested in the range (0.0 - 96%) of the relative humidity at room temperature. The results have shown that most of the obtained glass ceramic materials had a lower sensitivity towards RH. The composition 20SiO2.30Bi2O3.50TiO2 has possessed the highest permittivity value (3000 F.m-1) and the lowest value of dielectric loss (0.0002) at room temperature which make it a promising candidate for some industrial applications such as energy storage, electronic capacitors as well as memory devices.
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    Preparation and characterization of a zinc oxide nanopowder supported onto inorganic clay
    (2016-01-01) Hassan M.; Afify A.S.; Ataalla M.; Mohammed A.; Staneva A.; Dimitriev Y.; Tulliani J.M.
    Zinc oxide nanoparticles are obtained by a wet chemical method using zinc sulphate as a raw material. Doping sepiolite, micro-fibrous inorganic clay, with ZnO after precipitation under basic conditions and subsequent thermal treatment is investigated as both materials are abundant. They are used for the development of humidity and gas sensors of great environmental importance. The particle size distribution, the morphology and the composition of the powder samples are characterized by X-Ray diffraction accompanied by Field Emission Scanning Electron Microscopy and High Resolution-Transmission Electron Microscopy techniques. The data obtained confirm the formation of zinc oxide nanoparticles of a size of 10 nm on the modified sepiolite grains.