Search for: metallic-molybdenum
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    Recovery of metals from spent refinery hydrocracking catalyst using adapted Aspergillus niger

    , Article Hydrometallurgy ; Volume 109, Issue 1-2 , 2011 , Pages 65-71 ; 0304386X (ISSN) Amiri, F ; Yaghmaei, S ; Mousavi, S. M ; Sheibani, S ; Sharif University of Technology
    This study was designed to compare one-step, two-step and spent medium bioleaching of spent catalyst by adapted Aspergillus niger in batch cultures. Aspergillus niger, which was adapted to heavy metal ions, Ni, Mo, Fe, and W, was grown in medium containing up to 5% (w/v) of spent catalyst. The main lixiviant in bioleaching was gluconic acid, which was produced at all pulp densities in the one-step bioleaching process. Gluconic acid was also produced in the two-step bioleaching process when the spent catalyst was present at pulp densities greater than 1% (w/v). In the spent medium leaching, however, the primary agent was citric acid. The pulp density of the spent catalyst was varied, and this... 

    A study of Acidithiobacillus Ferrooxidans DSMZ 583 Adaptation to Heavy Metals

    , Article Iranian Journal of Biotechnology ; Volume 9, Issue 2 , 2011 , Pages 133-144 ; 17283043 (ISSN) Yaghmaei, S ; Ghobadi, Z ; Sharif University of Technology
    In this study the ability of Acidithiobacillus ferrooxi-dans, with regard to the biorecovery of heavy metals in shake flask has been investigated. Adaptation experiments with the single metal ions Ni, Co, V, Mo, W and a mixture of the first four metal ions in the medium was developed through serial sub-culturing. Adaptation showed that A. ferrooxidans could tolerate up to 2.3 g/l Ni, 1.4 g/l Co, 1.4 g/l V, 0.045 g/l Mo and 0.005 g/l W, singly. In the presence of multi-metals considering a mixture of Ni-Co-V-Mo, the bacteria was able to tolerate up to 1.5 g/l Ni, 0.8 g/l Co, 0.8 g/l V and 0.05 g/l Mo in steps of 50-100 mg/l for Ni, Co and V, while for Mo and W with increments in concentration... 

    Deposition of metallic molybdenum thin films on 304L steel substrate by SUT-PF

    , Article Surface and Coatings Technology ; 2016 ; 02578972 (ISSN) Hosseinzadeh, A ; Nazmabadi, M ; Vosoughi, N ; Sharif University of Technology
    Elsevier B. V 
    The present research work aims to employ plasma focus in order to deposit molybdenum (Mo) on the 304 stainless steel substrate. The processing parameters were shot numbers as well as the distance of substrate from the anode tip. Stereo, atom force microscopy (AFM) and field emission-scanning electron microscopy (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDS) were used to study the deposited coatings. Microhardness measurements were also performed on the coatings. Results indicated that the plasma focus can be successfully applied to deposit Mo anode on the stainless steel substrate. The coatings contained discrete pores with sizes varying by processing parameters. The... 

    A general two-step chemical vapor deposition procedure to synthesis highly crystalline transition metal dichalcogenides: a case study of MoS2

    , Article Materials Research Bulletin ; Volume 76 , 2016 , Pages 473-478 ; 00255408 (ISSN) Shidpour, R ; Vosoughi, M ; Maghsoudi, H ; Simchi, A ; Sharif University of Technology
    A green and simple synthesis method based on a two-step chemical vapor deposition approach has been developed to synthesize transition metal dichalcogenides flakes. With non-toxic precursor such as transition metal oxides and elemental sulfur, large-area, strong photoluminescent and uniform MoS2 nanoflakes were produced at a relatively low growth temperature (650 °C). Controlling the layer number and morphology was achieved only by precursor concentration without any oxide impurity revealed by SEM, PL and Raman spectroscopy. This method can be used to make wide range of metal chalcogenides such as ZnS, SnS2, PtS2 and PdS2  

    Process optimization and modeling of heavy metals extraction from a molybdenum rich spent catalyst by aspergillus niger using response surface methodology

    , Article Journal of Industrial and Engineering Chemistry ; Volume 18, Issue 1 , January , 2012 , Pages 218-224 ; 1226086X (ISSN) Mafi Gholami, R ; Mousavi, S. M ; Borghei, S. M ; Sharif University of Technology
    The present study examines the biorecovery of heavy metals from a spent refinery catalyst obtained from one of the oil refineries in Iran using Aspergillus niger. Bioleaching experiments were carried out in batch cultures using A. niger in the one-step process to mobilize Co, Mo and Ni from hazardous spent catalysts. Response surface methodology (RSM) was applied for the design and analysis of experiments with the optimization of pH, temperature, inoculum percentage, pulp density and rotation speed during the bioleaching of the metals. Experiments were designed as per the central composite design (CCD) technique. Three cubic mathematical models were derived for prediction of the responses.... 

    Enhancement of bioleaching of a spent Ni/Mo hydroprocessing catalyst by Penicillium simplicissimum

    , Article Separation and Purification Technology ; Volume 80, Issue 3 , August , 2011 , Pages 566-576 ; 13835866 (ISSN) Amiri, F ; Mousavi, S. M ; Yaghmaei, S ; Sharif University of Technology
    Statistically based experimental designs were applied to screen and optimize the bioleaching of spent hydrocracking catalyst by Penicillium simplicissimum. Eleven factors were examined for their significance on bioleaching using a Plackett-Burman factorial design. Four significant variables (pulp density, sucrose, NaNO3, and yeast extract concentrations) were selected for the optimization studies. The combined effect of these variables on metal bioleaching was studied using a central composite design (CCD). Second-order polynomials were established to identify the relationship between the recovery percent of the metals and the four significant variables. The optimal values of the variables... 

    Investigating the different conditions on solution processed MoOx thin film in long lifetime fluorescent polymer light emitting diodes

    , Article Materials Chemistry and Physics ; Volume 204 , 2018 , Pages 262-268 ; 02540584 (ISSN) Alehdaghi, H ; Marandi, M ; Irajizad, A ; Taghavinia, N ; Jang, J ; Zare, H ; Sharif University of Technology
    Elsevier Ltd  2018
    Transition metal oxides are being more frequently used as hole injection layer (HIL) in organic light emitting diodes (OLEDs), in place of polymer HILs such as PEDOT:PSS. The very thin films of the metal oxide HILs are usually deposited using vapor deposition, in order to create uniform films. Here, we report OLEDs fabricated using solution processed MoOx films as the HIL and super yellow as the emissive layer. The performance of the devices is comparable to PEDOT:PSS based devices, while the stability tests show the lifetime of MoOx-based devices is 4 × 106 h, about 40 times longer than PEDOT:PSS devices, at typical working condition. X-ray photoelectron spectroscopy (XPS) indicates both...