Loading...
Search for: dipping
0.011 seconds
Total 68 records

    Feasibility Study of Painting Line by Electro Deposition in Zagrosskhodro

    , M.Sc. Thesis Sharif University of Technology Fakouri, Hojjatollah (Author) ; Hooshmand, Mahmoud (Supervisor)
    Abstract
    Assurance about projects and industrial plans success always had been one of the most important concerns of investors. Car manufacturing industry is not excluded. In this project the painting line in zagrosskhodro company using electro deposition method is reviewed , analyzed, and investment feasibility study of such method is investigated . All aspect of investment including financial and economic aspect is reviewed by UNIDO methodology.
    The outcome is described here briefly.
    1- Production volume in this plan in complete capacity is equal to 40000 bodies in a year.
    2- The primary fixed investment capital is 132,187,912,140 Rls.
    3- Sum of fixed expenses of production is ... 

    Lanthanum Chromite Coating on Stainless Steel by sol–Gel Dip Coating Technique

    , M.Sc. Thesis Sharif University of Technology Rashtchi, Hamed (Author) ; Faghihi Sani, Mohammad Ali (Supervisor)
    Abstract
    Because of the high operating temperature, interconnect surface tends to be oxidized and Cr2O3 oxide layer will be created on the surface. This phenomenon is undesirable due to decreasing electrical conductivity, so a preservative coating is needed to improve the interconnect properties. In this paper, a dense perovskite thin film was successfully synthesized on a ferritic stainless steel (type 430) substrate by a sol-gel dip coating method. This coating improved chemical stability, oxidation behavior of the substrate and decreased cathode poisoning. The lanthanum chromite was coated on the substrate by sol-gel dip coating process. First, during a hydrolyze process, a stable sol was made up... 

    Fabrication of Mn/Co and Co Coatings on AISI 430 for SOFC Interconnect Via Sol-Gel and Dip Coating

    , M.Sc. Thesis Sharif University of Technology Dayaghi, Amir Masoud (Author) ; Askari, Masoud (Supervisor)
    Abstract
    With regard to recent progress in decreasing of operating temperature of Solid Oxide Fuel Cell (SOFC), metallic interconnect use widely than ceramic interconnect. Metallic interconnect have interested due to their low cost, easy fabrication and high electronic and thermal conductivity.oxidation resistance of metals is big challenge, because of low conductivity of formed oxide layers that led to increasing of electrical conductivity. Ferritic stainless steel is among the most thriving candidate alloy because of BCC structure that its coefficient of temperature expansion is close to that of other SOFC. Nonetheless, the increase of electrical resistance over the time and the evaporation of... 

    Numerical Analysis of Failure Mechanisms in Saw-Tooth and Natural Joints of Rock Mass Under Shear

    , M.Sc. Thesis Sharif University of Technology Garakany, Hadi (Author) ; Sedghiani, Mohammad Hossein (Supervisor)
    Abstract
    Needs for construction of rock structures and underground ones such as underground tunnels, dam foundations, trenches for roads and railways, power plants and caverns built to keep oil, gas and nuclear waste has increased dramatically. In order to design, construct and excavate these underground structures safely and economically, full understanding of rock mass properties, suitable tools and practical techniques of drilling are necessary. Because of existing discontinuities, including joints and layered rock masses and their effects on mechanical behavior of rock mass, it is necessary for the geo-mechanical profile, shear strength and failure mechanism of rock mass to be accurately... 

    Preparation and Stabilizing Graphene Sheets for Gas Sensing Application

    , M.Sc. Thesis Sharif University of Technology Mirmotallebi, Mona (Author) ; Iraji zad, Azam (Supervisor)
    Abstract
    Graphene is one of the most attractive subjects for scientists in the last decade. Its unique properties has been probed by many research groups and innumerable projects have been developed to investigate applications of graphene in electronics, mechanics, biophysics etc. Due to high surface to volume ratio and magnificent electron mobility in graphene, it is a suitable candidate for gas sensing. This has been proved by several theoretical and experimental researches for various gases such as CO, NH3 and NO2 etc. In present thesis, graphene has been prepared chemically and transferred to silicone substrates that are previously coated with a 300 nanometer silicone dioxide layer, by dip... 

    BiFeO3 Thin Films Deposition by Sol-Gel and Dip Coating Process

    , M.Sc. Thesis Sharif University of Technology Kianinia, Mehran (Author) ; Nemati, Ali (Supervisor) ; Alizadeh, Masoud (Supervisor)
    Abstract
    Dark and light conductivity has been investigated in Ca-doped bismuth ferrite thin films. Higher conductivity in the order of 105 magnitude of pure Bismuth ferrite has been observed for Bi0.85Ca0.15FeO3-δ. Structural analysis using Rietveld refinement showed a deviation from volume reduction for Bi0.85Ca0.15FeO3-δ that could be the reason of the abnormally high conductivity for this compound. Although higher calcium doping reduced conductivity but photoresponse could be revived. Atomic Forec Microscopy investigations showed that surface roughness decreases with increasing calcium concentration. Enhanced photoconductivity is reported for Bi0.7Ca0.3FeO3-δ with ~2.9 eV direct optical band gap... 

    Cobalt Based Spinel Coating on Stainless Steel by Sol-Gel Dip Coating Technique for Interconnects

    , M.Sc. Thesis Sharif University of Technology Jalilvand, Golareh (Author) ; Faghihi Sani, Mohammad Ali (Supervisor)
    Abstract
    Because of the high operating temperature, interconnect surface tends to be oxidized and Cr2O3 oxide layer will be created on the surface. This phenomenon is undesirable due to decreasing electrical conductivity, so a preservative coating is needed to improve the interconnect properties. In this paper, a dense spinel thin film was successfully synthesized on a ferritic stainless steel (type 430) substrate by a sol-gel dip coating method. This coating improved chemical stability, oxidation behavior of the substrate and decreased cathode poisoning. The Nickel-Cobalt spinel was coated on the substrate by sol-gel coating process. First, during a hydrolyze process, a stable sol was made up from... 

    , M.Sc. Thesis Sharif University of Technology Fazlali, Masoume (Author) ; Moshfegh, Ali Reza (Supervisor) ; Akhavan, Omid (Supervisor)
    Abstract
    In photocatalitic activity of titana an effective approach to achieve high charge separation efficiency and high level of sensitivity under visible light is coupling it with another semiconductor with smaller band gap and appropriate banding energy structure. achieving all mentioned above, we used bilayer structure and coupled TiO2 with hematite which its small band gap(Eg ~ 2.1 ev) is sensitive to visible light. Bilayer systems of TiO2/Fe2O3 , Fe2O3/TiO2 were fabricated by sol-gel process and variable parameter was upper layer thickness. The layers were deposited on glass substrate via sol-gel process. The upper layers were prepared in different thicknesses in two ways. First, they... 

    Preparation and Characterization of ZrO2 Antistatic Coatings on Glass

    , M.Sc. Thesis Sharif University of Technology Naderi, Armaghan (Author) ; Dolati, Abolghasem (Supervisor) ; Afshar, Abdollah (Supervisor)
    Abstract
    In this study, the zirconia antistatic coating was synthesized by dip coating sol-gel route on glass substrate. The solution contains ZrCl4 as precursor and isopropanol as solvent to synthesize zirconium oxide. The effects of environmental humidity and solution concentration on the coating characterization were analyzed. MPTS and primer binder were added as binding agents in the solution to observe the effect of binding agents on the coating adhesion. Solution stability and antistatic coating characterization were analyzed by zita potential test, FTIR spectroscopy, EDX analysis, FESEM and AFM microscopy, pencil hardness test, thickness test, antidust ability and spectrophotometer. The... 

    YSZ Coating on Ferritic Stainless Steel Interconnect through Sol-Gel Method and Studying its Reaction with Glass Sealant in SOFC

    , M.Sc. Thesis Sharif University of Technology Mousa Mirabad, Homayoun (Author) ; Faghihi Sani, Mohammad Ali (Supervisor) ; Nemati, Ali (Supervisor)
    Abstract
    Solid oxide fuel cells are used to convert solid-state energy to direct electrical current by electrochemistry mixing a gas fuel and an oxidant in an oxide electrolyte. One of the most interesting aspects of this field for the researchers is the reaction between the metal interconnect and the glass sealant. In the current research, deposition of the YSZ coating onto the metal interconnect in order to impede the reaction with glass sealant and prohibition of its oxidation in oxidizing/reducing environment in high temperature, was mainly investigated. Effect of applying YSZ Thin layer in the intersection of Crofer steel and glass sealant on strength and chemical durability of these two... 

    Analysis and Enhancement of Low Voltage Ride Through Of Wind Turbines with Brushless Doubly Fed Induction Generator

    , Ph.D. Dissertation Sharif University of Technology Gholizadeh, Mahyar (Author) ; Oraee Mirzamani, Hashem (Supervisor) ; Tohidi, Sajjad (Co-Advisor)
    Abstract
    Wind energy technologies guarantee low pollution and operational costs. Using a DFIG and a fractionally rated power electronics converter gives variable speed operation with a low cost drive train. As energy policy organizations have allocated a considerable quota of wind energy generation to offshore wind farms, the absence of slip rings and brushes in the brushless DFIG (BDFIG) is an advantage for offshore wind turbines where maintenance is vital and expensive. With increasing wind power penetration in power systems, grid code requirements are an important consideration for the ride-through capability of wind farms through voltage dips, particularly for multi- MW wind turbine generators.... 

    Analysis and Improvement of Dynamic Behavior of Brushless Doubly-Fed Induction Generator in Wind Turbines

    , M.Sc. Thesis Sharif University of Technology Tohidi, Sajjad (Author) ; Oraee Mirzamani, Hashem (Supervisor) ; Zolghadri, Mohammad Reza (Supervisor)
    Abstract
    Recently, the brushless doubly fed induction generator (BDFIG) has been proposed to be used in wind turbines due to variable speed operation with fractionally size power electronic converter and without brushes and slip rings. In this thesis, for the first time, LVRT capability of BDFIG has been assessed regarding the grid codes and several approaches have been suggested for improving it. Firstly, the steady-state performance of the BDFIG in different operating modes has been investigated and required tests have been performed. In addition, a new operating mode named as "double cascade mode" has been introduced. The fault-on performance of BDFIG has also been studied by means of torque-speed... 

    H2S Gas Sensing Characterization of Nano-Structured SnO2-CuO Multilayer Sensor

    , M.Sc. Thesis Sharif University of Technology Salehi, Farnaz (Author) ; Ghorbani, Mohammad (Co-Advisor)
    Abstract
    Hydrogen sulfide, H2S, is a toxic gas and has detrimental effects on human health and the oil and gas industry. Therefore, its identification is very important. According to the devastating effects of this gas, then, the general mechanisms have been studied for gas detection. In addition, by highlighting the benefits of the multilayer nanostructure electrochemical sensors, an applicable and efficient method for the industrial production of these sensors has been investigated. In this regard, the sol-gel method is used to prepare the SnO2-CuO multilayer thin film and the advantages of this method was compared to PVD method. Also sensor properties of both deposition methods have been... 

    Design and Implement a High Voltage Switching DC Power Supply Based on Voltage Multiplier for High Regulation and Controllable Output Voltage

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Abbas (Author) ; Kaboli, Shahriyar (Supervisor)
    Abstract
    High DC voltage is widely used in many applications such as X-Ray machines ,CRT , photocopy machines and etc. One idea to produce this high DC voltage is to use transformers, but it will be large in volume. We can increase frequency to reduce the volume of transformers but high voltage of primary and secondary winding will limited this volume reduction. Furthermore high turn ratio in transformers increases non idealities that cause voltage and current spike, and increase loss and noise. The main goal of this thesis is to reduce differential mode voltages on transformers to reduce the volume of power supply. Voltage multiplier will be used to reduce differential mode voltage. Voltage... 

    Preparation and Characterization of Asymmetric and Thin Film Composite Nanofiltration Membranes for Water Softening

    , M.Sc. Thesis Sharif University of Technology Mokhtari Garekani, Rasoul (Author) ; Mousavi, Abbas (Supervisor) ; Roosta Azad, Reza (Supervisor)
    Abstract
    In this study three type of nanofiltration membranes were prepared from PVC for water softening; (i) asymmetric PVC nanofiltration membrane, and two different thin film composite (TFC) membranes: (ii) polyamide (PA)/PVC composite membrane (iii) poly vinyl alcohol (PVA)/PVC composite membrane. Asymmetric nanofiltration membranes were prepared by phase inversion. The effect of PVC concentration, solvent (THF) and additive (PVP) on morphology and performance were studied by scanning electron microscopy (SEM) and measuring pure water flux and salt rejection. Increasing PVC concentration decreased pure water flux and increased salt rejection. Adding tetrahydrofuran(THF) decreased the pure water... 

    Selection of a Nanostructured Pattern for Increasing Absorption Efficiency of a Solar cell Based Based on TiO2

    , M.Sc. Thesis Sharif University of Technology Daneshvare Asl, Shervin (Author) ; Sadrnezhad, Khatiboleslam (Supervisor) ; Mohammadi, Mohammad Reza (Co-Advisor)
    Abstract
    Dye–sensitized solar cell (DSSC) includes (a) A transparent conductive oxide coated glass substrate, (b) Semi conductive film, (c) Dye adsorbed on this film, (d) Redox couple electrolyte and (e) A counter electrode which can reduce redox couple.In this study, selection of a nanostructured pattern for increasing absorption efficiency of a DSSC based on TiO2 has been considered. For this purpose, using carbon nanotubes (CNTs) in fabrication of photoelectrode has been proposed. Therefore, at the first TiO2–CNT nanocomposites contained various percent of carbon nanotube was coated on fluorinated tin oxide (FTO) conductive glasses via sol–gel dip coating method. Then DSSCs were assembled by... 

    An Investigation on Photocatalytic Behavior of N-doped and N-V-doped TiO2 Thin Film, Coated on Glass Surface by Sol-gel Dip Coating Method

    , M.Sc. Thesis Sharif University of Technology Khatibnezhad, Hediyeh (Author) ; Faghihi Sani, Mohammad Ali (Supervisor)
    Abstract
    In this study, the photocatalytic activity and hydrophilicity of coat improved using Nitrogen and Vanadium elements as dopant in TiO2 coating. By using vanadium and nitrogen elements and silica prelayer, a titania coating was deposited on the soda-lime glass substrate by sol-gel dip coating method to produce self-cleaning surface. XRD and FTIR analyses were done on the powders after heat treating at in 450˚C for 30 min. XPS analysis was done for investigation of N replacement in titania structure. The band-gap energy of formed anatase was derived using UV-Vis analysis. The coating morphology and thickness were also investigated by SEM. Hydrophilicity of coatings was determined by measuring... 

    Investigation of Parameters for Controlling Morphology and Pore Size in UF Mambrans

    , M.Sc. Thesis Sharif University of Technology Mokhtare, Amir (Author) ; Seyfkordi, Ali Akbar (Supervisor) ; Hemmati, Mahmud (Supervisor)
    Abstract
    In order to increase the life-cycle of membrane filtration systems, energy efficient membranes are being developed in membrane bioreactor systems. Technology has been introduced which allows the power required to aerate the membrane for cleaning to be reduced whilst still maintaining a high flux level. Mechanical cleaning processes have also been adopted using granulates as an alternative to conventional forms of cleaning; this reduces energy consumption and also reduces the area required for filtration tanks.Membrane properties have also been enhanced to reduce fouling tendencies by modifying surface properties. This can be noted in the biotechnology industry where membrane surfaces have... 

    Synthesis photocatalytic TiO2/ZnO nanocomposite and investigation through anatase, wurtzite and ZnTiO3 phases antibacterial behaviors

    , Article Journal of Nano Research ; Volume 51 , 2018 , Pages 69-77 ; 16625250 (ISSN) Mohammadi, H ; Ghorbani, M ; Sharif University of Technology
    Trans Tech Publications Ltd  2018
    Abstract
    Titanium dioxide is prepared by sol gel method from titanium tetraisopropoxide (TTIP) as precursor and likewise zinc oxide is prepared by sol gel method from zinc acetate dehydrate (ZAD) as precursor. The composite sols are prepared in three different molar ratios 90TiO2:10ZnO, 70TiO2:30ZnO and 50TiO2:50ZnO. Thin film deposition is carried out by dip coating technique. Crystal structure, surface morphology and photocatalytic activity of the prepared nanocomposite thin films are investigated. The antibacterial activity of the prepared nanocomposite thin film against E-coli ATCC 25922 bacteria is examined by placing the thin film in standard aqueous E-coli medium under UV light for 1, 2, 3 and... 

    Sol–gel preparation and corrosion properties of Zn–SiO2 nanocomposite thin film

    , Article Journal of Sol-Gel Science and Technology ; Volume 79, Issue 1 , 2016 , Pages 133-143 ; 09280707 (ISSN) Razavizadeh, O ; Ghorbani, M ; Sharif University of Technology
    Springer New York LLC 
    Abstract
    In this study, a novel nanocomposite thin film of Zn–SiO2 is considered. The thin film is a viable alternative for higher abrasion-resistant coatings. DLS technique revealed that the nanoparticle size is to be below 10 nm, and FE-SEM showed particle size to be below 17 nm in the obtained coating. The coating was found to be highly adhesive with an amorphous structure and hardness value above 1000HV. Corrosion resistance studies using linear polarization technique revealed that this unique nanocomposite has a lower corrosion rate than hot-dip galvanized steel at higher positive potentials. A conclusive mechanism for corrosion and erosion improvement has been proposed. Graphical Abstract:...