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    Dispersivity, collapsibility and microstructure of a natural dispersive loess from Iran

    , Article 16th Asian Regional Conference on Soil Mechanics and Geotechnical Engineering, ARC 2019, 14 October 2019 through 18 October 2019 ; 2020 Sadeghi, H ; Nasiri, H ; Panahi, P. A ; Sadeghi, M ; Sharif University of Technology
    Asian Regional Conference on Soil Mechanics and Geotechnical Engineering  2020
    Abstract
    A new type of collapsible soil was encountered in Southern Iran and caused some serious technical problems including subsidence, collapse and sinkholes during the construction of Zahedan-Chabahar railway. Field observations indicated that in-situ soil contains excessive amount of salts resulting in dispersive features in response to seepage forces in addition to its collapsibility. Therefore, a systematic research plan including field sampling and laboratory testing was carried out to investigate the observed geotechnical features. Results of physio-chemical tests revealed the dominance of Sodium in excess of 70% relative to total dissolved salts, which results in high dispersive potential.... 

    Bactericidal effects of Ag nanoparticles immobilized on surface of SiO2 thin film with high concentration

    , Article Current Applied Physics ; Volume 9, Issue 6 , 2009 , Pages 1381-1385 ; 15671739 (ISSN) Akhavan, O ; Ghaderi, E ; Sharif University of Technology
    2009
    Abstract
    Bactericidal activity of high concentration Ag nanoparticles immobilized on surface of an aqueous sol-gel silica thin film was investigated against Escherichia coli and Staphylococcus aureus bacteria. Size of the surface nanoparticles was estimated in the range of 35-80 nm by using atomic force microscopy. Due to accumulation of the silver nanoparticles at near the surface (at depth of 6 nm and about 40 times greater than the silver concentration in the sol), the synthesized Ag-SiO2 thin film (with area of 10 mm2) presented strong antibacterial activities against E. coli and S. aureus bacteria with relative rate of reduction of the viable bacteria of 1.05 and 0.73 h-1 for initial... 

    Self-accumulated Ag nanoparticles on mesoporous TiO2 thin film with high bactericidal activities

    , Article Surface and Coatings Technology ; Volume 204, Issue 21-22 , August , 2010 , Pages 3676-3683 ; 02578972 (ISSN) Akhavan, O ; Ghaderi, E ; Sharif University of Technology
    Abstract
    Antibacterial activity of sol-gel synthesized Ag-TiO2 nanocomposite layer (30nm) deposited on rough anatase (a) TiO2 thin film (~200nm in thickness) was investigated against Escherichia coli bacteria, in dark and also in exposure to UV light. The nanocomposite thin films were transparent with a surface plasmon resonance absorption band at a wavelength of 410nm. The metallic silver nanoparticles with an average diameter of 30nm and fcc crystalline structure were self-accumulated on surface of a mesoporous and aqueous TiO2 layer with a capillary pore structure having a pore radius of 3.0nm. By adding the silver nanoparticles in the TiO2 layer, recombination of the photoexcited electron-hole...