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    Experimental Investigation for Enhancing the Lifetime of Co,Ru/La(γ-Al2O3) Catalyst in Fischer Tropsch Synthesis

    , Ph.D. Dissertation Sharif University of Technology Hemmati Mahmoudi, Mohammad Reza (Author) ; Kazemeini, Mohammad (Supervisor) ; Khorasheh, Farhad (Supervisor) ; Zarkesh, Jamshid (Co-Advisor)
    Abstract
    Fischer-Tropsch synthesis (FTS) is the main part of a Gas to Liquid (GTL) process. In this reaction which shall be done based upon iron or cobalt catalysts, H2 and CO molecules (namely Syngas) transform to long hydrocarbon chains. Regarding all of the advantages of cobalt catalysts in comparison with iron counterparts, Research Institute of Petroleum Industry (RIPI) began investigations since two decade ago. The present catalyst comprised of cobalt as active metal, ruthenium as activity promiter and lanthanum as support (gamma alumina) modifier. By the way, still some areas such as its lifetime duration and deactivation needs to be improved by complimentary researches. The present... 

    Leaching, Solvent Extraction and Separation of Cerium, Lanthanum, Neodymium Rare Earth Elements from Apatite Concentrate of Chadormalu Mine

    , Ph.D. Dissertation Sharif University of Technology Ferdowsi, Ali (Author) ; Youzbashizadeh, Hossein (Supervisor)
    Abstract
    Waste of iron ore concentrate production plant of Chadormalu contains apatite mineral. The content of rare earths elements (REEs) in apatite concentrate of Chadormalu is about one percent. However, considering apatite deposite and production rate, extraction of REEs from apatite is one of valuable source for production of REEs. Lanthanum, cerium and neodymium which have most application amonge other REEs and have the highest frequency in the apatite. Due to their similar physical and chemical properties, it is difficult to separate individual rare earths from each other and the separation process are too complicated. In this study, in order to extract REEs from apatite, it was leached by... 

    an Investigation on REEs' Cerium, Lanthanum, Neodymium leaching from Phosphate Concentrate of Iron Ore Waste in Acidic Environment and Studing Purification and Concentration of the Solution

    , M.Sc. Thesis Sharif University of Technology Aghaeian, Soroush (Author) ; Yoozbashizadeh, Hossein (Supervisor)
    Abstract
    The term “Rare Earth”, represents 17 metalic elements such as Sc, Y and Lanthanides wich have similar chemical properties. Lanthanides are a group of elements with atomic numbers of 57 to 71 that all of them exept Pm are present in nature. Rare earth elements are never concentrated in a special mine rock, but they could be found in various rocks and at very low concentrations. In the present study, apatite concentrate of Chadormalu was used for leaching and solvent extraction of Cerium, Lanthanum and Neodymium. After leaching step, its optimum conditions were found as follow: 30% nitric acid, 10 mins time and 10% for solid to liquid ratio. After finding optimum conditions, sufficient leach... 

    Fabrication and Evaluation of Mechanical and Anti-corrosion Properties of Epoxy Resin/Carbon Nanofibers Containing Organic Corrosion Inhibitors

    , M.Sc. Thesis Sharif University of Technology Ghaderi, Mohammad (Author) ; Ramazani Saadat Abadi, Ahmad (Supervisor) ; Mahdavian Ahadi, Mohammad (Supervisor)
    Abstract
    To protect mild steel against corrosion, an intelligent self-healing epoxy (EP) coating including carbon nanofiber (CNF) modified with polydopamine (PDA)-La (III) complex was successfully fabricated. The high aspect ratio and unique thermal and electrical characteristics of CNF made it an ideal physical barrier against the penetration of corrosive ions. Due to the poor dispersion of CNF, its surface was modified using PDA. PDA, which contains functional groups such as catechol, amine, and imine, can mitigate corrosion reaction by generating the Fe-Catechol complex and also boost the coating's adherence to the metal surface, in addition to anchoring La3+ inorganic corrosion inhibitor....