Sharif Digital Repository

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 ... 

We studied porous silicon as a resistive gas sensor at room temperature. Meso- and macro- porous silicon were formed by electrochemical etching of single crystal silicon wafers in different conditions. For Meso porous Si we used p+-type wafers as substrate and for macro porous Si formation n- and p-type wafers were used. The mechanism of methanol vapor sensing was studied by Scanning tunneling spectroscopy and Fourier transform infrared spectroscopy. The results showed that methanol increases partial oxidation of surface and causes increase of defect density. These defects play important role to trap electrons and create “acceptor surface states”. These acceptor surface states in p+-type... 

Ni-P alloy coatings were electrodeposited using pulse current in a watt type bath in various conditions. The influences of different parameters were investigated and optimized for the highest amount of coating hardness using the Design Of Experiment (DOE) method. The optimized deposition parameters were current density 23.7 A/dm2, duty cycle 75%, frequency equal to 188 Hz, temperature equal to 70ºC and 17.5 gr/l of H3PO3. The DOE prediction of hardness for the optimized coatings was between 700 and 750 the achieved micro-hardness was about 725.8 HV. It was obtained that an increase of the current density will improve micro-hardness, decreases P content and increase deposition rate. Also, the... 

Electrocatalytic oxidation of L-ascorbic acid (L-AA) on silver electrode in alkaline solutions was studied employing cyclic voltammetry, chronoamperometry and impedance spectroscopy techniques. In comparison to Pt, the onset potential for L-AA electro-oxidation process on Ag, in a solution containg 0.02 M L-AA and 0.5 M NaOH, was 0.1 V more negative. Also, L-AA oxidation current increased more than 900% at -0.26 V/SCE. According to voltammety and impedance spectropy findings, although hydroxide anion presence was vital for L-AA oxidation to occur, at potentials more positive than -0.2 V/SCE, hydroxide ion tends to inhibit the oxidation process. Studies on the L-AA oxidation process on Ag in... 

Alloy coating of nickel - molybdenum with 20-25 wt% Mo, exhibits excellent protective properties against corrosion in different corrosive environments, therefore it has received much attention. In comparison with Ni coatings, Ni-Mo coatings reduce hydrogen evolution reaction overpotential(HER) significantly, therefore it has suitable catalytic properties for HER.
A few researches on pulse reverse palting of Ni-Mo coatings have been published. in this work, we have evaluated effects of PRC on some properties of Ni-Mo coating such as chemical composition, morphology, catalytic properties for HER, crystaline structure and hardness property. The results of atomic absorption spectroscopy(AAS)... 

An efficient method has been developed to synthesize well-aligned multi-walled carbon nanotubes (MWCNTs) on a conductive Ta substrate by chemical vapor deposition (CVD). By varying CVD parameters, aligned CNTs (A-MWCNTs) with diameter between 20-100 nm and length of some micrometers with bamboo-like shapes were produced. Free-standing MWCNTs arrays were functionalized and purified through electrochemical oxidation. Then in order to improve the performance, facile template-free electrochemical routes were developed for the shape-selective synthesis of less-common Au nanostructures, including flower, sphere, dendrite, sheet and rod on A-CNTs at room temperature. The results showed that the... 

Detection and determination of ultra-trace electroactive materials using electrochemical methods have been widely employed by researchers since they offer a fast, easy and reliable approach. In this way, developing of new nanoelectrodes with special and unique properties plays a profound role on the achievement of better results.
Gold nanoelectrode ensembles are one of the most important nanoelectrodes which due to the high surface area, chemical, electrochemical and physical stability, and integration of a large number of individual nanoelectrodes, introduce excellent opportunities to be employed as promising nanoelectrodes in determinations applications.
In this work, preparation... 

Additional to Temperature, Pressure and Compositional changes of crude oils, Electro-kinetics and Electrical potential effects are also known as the most influencing parameters on Asphaltene deposition during oil production and processing.Mechanisms of electro-kinetics and asphaltene charge generation are very complex and unclear. In the previous studies on asphaltene precipitation and deposition, mostly electro-kinetics effects are ignored.While, recent studies show the great effects of electrical filed on asphaltene deposition during production and processing phase of crude oils.At reservoir porous medium and crude flow line, an electrical field can be developed along the length of the... 

Recently magnesium alloys have shown great potential as biodegradable metallic implants. However, due to high corrosion rate in the body environment, these alloys would be degraded before the tissue healing time period. Therefore corrosion resistance of these alloys has to be improved in order to be used in biological environments. In the present work, supposing improvement of corrosion properties of magnesium AZ91D alloy, the alloy has been coated with biocompatible nano-Zirconia particles using Electrophoretic deposition method and the effects of deposition parameters such as bath agitation, Zirconia concentration, current density and duration of deposition process on the properties of the... 

Electrocodeposition of Ni-TiO2 nanocomposite single layers and Ni-TiO2/TiO2 multilayers from Watts bath containing TiO2 sol has been carried out on copper substrate. Cyclic voltammetry and chronoamperometry techniques were applied to study the influence of nickel sulfate and TiO2 sol concentrations on the electrochemical behavior of Ni-TiO2 deposition by direct current. The results clearly showed that at lower sulfate concentrations, the electrodepostion is a diffusion controlled process. Besides, the nucleation mechanism of the nanocomposites at low overpotentials followed the progressive system while at higher overpotentials, it was found to be instantaneous with three-dimensional growth... 

The purpose of this study is to investigate the effect of halids on electrooxidation of silver in alkalie medium. For this case, electrochemical teqniques such as Chronoamperometery (CA) and Cyclic Voltammetry (CV) were applied. Characterization of the electrodeposition process is based on quantitative analysis of the potentiostatic current versus time curves. Rate constants of nucleation and growth obtained from the fit of the recorded transients to the generalized equations derived based on Abyaneh and Flischmann model. The conditions that justify the use of the limiting forms of the transient equations for the so-called “ instantaneous” and “ progressive” nucleation processes were... 

Nowadays, nanotechnology has emerged in many processes; hence the construction of this scale is also important. By reducing the size of equipment, raw material consumption is reduced and less space is needed for equipment. In addition it is economical. LIGA method has the potential to make parts with small dimensions and accurate tolerances, that it is impossible with other methods (chemical vapor deposition, physical vapor deposition, bulk micromachining, surface Machining). It is possible to assemble the pieces by producing micro-molding in LIGA procedure.In this thesis, numerical simulation of electrodeposition that is one of the main steps in the LIGA procedure has been investigated. One... 

In this project single sided dye sensitized solar cell is introduced as a new design that has both of electrodes in one side. These electrodes can be separated vertically by a thin insulator layer such as SiO2 or horizontally by lithographic method. First a metallic thin film is patterned by lithography, and then thickened by electrochemical deposition of Chromium. Platinum is electrodeposited on the substrate of counter electrode and a thin spacer layer is deposited on Platinum layer to separate it from Titanium dioxide layer.
In Chapters 1, 2 & 3 basic science and methods which are needed for doing this project is introduced. In chapter 1 material for making a standard dye sensitized... 

The present work describes sensing application of modified Pt nanostructures towards detection of glucose. Modified Pt nanostructured electrodes were prepared using electrodeposition method such as chronoampermetry and potentiostatic pulse methods. The electrodeposition of Pt nanostructures was first studied by voltammetry and amperommetry techniques and then potentiostatic pulse method has been used to produce the alloyed structures of platinum. In this regard, the first electrode was proposed based on alloyed Pt/Ni nanowire arrays (NWAs) for the non-enzymatic detection of glucose. The Pt/Ni NWAs were prepared by pulse electrodeposition of Pt and Ni within a nano-pore polycarbonate (PC)... 

In this research a copper- diamond nanocomposite coating prepared by electrodeposition from a sulfate bath in order to increase the hardness and erosion resistance of cooper without disturbing cooper's specific physical properties as like as electrical and thermal conductivity. The mechanism of electrodeposition was analyzed with the technique of Cyclic Voltammetry, Chronopotentiometry and Chronoamperometry. The morphology, hardness, scratch resistance, elastic modulus and friction factor of coating were investigated by using a scanning electron microscope (SEM) and atomic force microscope(AFM) also the mechanism of co- deposition of diamond particles with copper was corresponded with... 

In this research a copper- Tungsten carbided nanocomposite coating prepared by electrodeposition from a sulfate bath in order to increase the hardness and erosion resistance of cooper without loosing cooper's specific physical properties as like as electrical and thermal conductivity. Various parameters were evaluated for finding significant factors in electrodeposition of Cu-Co/WC composite. Current density and concentration of WC and SDS were selected as affective factors. The morphology and structure were characterized by XRD and SEM. The mechanical properties of the coatings, such as hardness, wear resistance and surface roughness were studied with Vickers hardness indentation; pin on... 

In this project Ni-SiC nanocomposite coatings were electrodeposited using Watts nickel bath with addition of SiC particles to the bath. Optimization of Ni-SiC electrodeposition parameters was done using Response Surface Methodology (RSM). At specific conditions, 67 Vol% of 10nm SiC is incorporated in nickel electrodeposits which is unique and not yet reported. Study nanomechanical properties of these coatings using Nanoindentation method, it was realized that the dislocation density is increased as force increasing which is in agreement with increasing intensity of (220) and (200) reflections and intensity attenuation of (111) reflection. Nanoscratch tests show that these... 

Silver is a resistant metal against the oxidation under normal atmospheric conditions, but it reacts readily with sulfur bearing species in the environment and corrodes. Alloying silver with more noble elements, such as Palladium, is a promising approach for increasing corrosion resistance against the sulfur pollutants. The purpose of this research is to develop a plating bath for deposition of Silver-Palladium alloy with acceptable appearance and higher corrosion resistance than pure silver. For this purpose, a bath based on thiosulfate complexing agent was investigated. In this solution, with a bath containing 10 mM of each cation, deposits with palladium content of 6, 11 and 14 % were... 

In present study, with the aim of fabrication of a sacrificial coating with superior barrier properties in comparison with Zn-Ni monolayer, a single Zn-Ni-P bath was developed for electrodeposition of Ni-P/Zn-Ni multilayers. The deposits that were prepared in developed bath at 5 mA/cm2 was dominantly Ni-P containing less than 1 percent Zn and the alloy deposited in 60 mA/cm2 was mainly Zn-Ni containing around 3.2 wt.% P content. The effects of bath ingredients on the electrodeposition mechanism was analyzed through voltammetry. Also, the composition, surface morphology and the growth mechanism as well as the phase structure of deposits were studied via SEM, EDS and XRD analysis. Zn-Ni... 

Ni-Co/SiC composite coatings with various contents of SiC nano particles were electrodeposited in a modified watt type of Ni-Co bath containing 20 nm SiC nano particles to be codeposited. The influences of the SiC concentration, current density, stirring rate of the deposition bath on the composition of the coatings were investigated and these parameters optimized for highest amount of SiC codeposition. The optimized deposition parameters were 40 g/l SiC and 480 rpm stirring rate and current density equal to 4 A/dm2. Ni-Co/SiC composite coating was deposited with the maximum particles content of 30.5 volume percent. Linear voltammetry demonstrates addition of the SiC to the Ni-Co deposition...