Showing 5 results for Amini
Pakshir M., Amini R.,
Volume 2, Issue 1 (Oct 2005)
Abstract
Anodes are critical component of cathodic protection systems. As part of this effort, three different anodes were tested in a cathodic protection system that was designed and constructed to prevent further corrosion of reinforced concrete. This anodic system includes an electrically conductive coating composition applied in fluid form over an outer surface of the concrete mix. The composition further includes a predetermined amount of electrically conductive carbon material (coke, carbon black, graphite) uniformly distributed in the epoxy resin (as a binder) whereby the coating composition has a predetermined value of resistively. This investigation attempts to find the best type and optimum content of conductive carbon filler in poxy coating, to ensure optimal anode working parameters for marine environments (basically marine and sewer environments) and if any of the coating systems tested in this study excel over the other. In this study, electric and electrochemical parameters of three layer (with average coating thickness of 300µm) coke-epoxy, carbon black-epoxy and graphite-epoxy conducting paints (with different amount of filler) have been determined during long-term anodic polarization (70 days) in a seawater solution. During this test, on the basis of impedance measurements, the electrical resistances of these coatings have been calculated every 14 days. if conductive paints exhibit good electric and electrochemical stability, they will be attractive for cathodic protection of reinforced concrete.
M. Ozve Aminian, J. Hedjazi, Y. Kharazi,
Volume 6, Issue 3 (Summer 2009 2009)
Abstract
Abstract: In this research, the oxidation behaviour of high Aluminum heat resistant steel (%25Cr,%20Ni,%8Al) hasbeen evaluated at the temperature range of (1000-1300ºC).The results showed that there was no countinous healinglayer on the surface of the alloy when Al increased up to %5.5 and the oxidation resistance of steel decreased due toformation of spinel oxides on the surface.By increasing the aluminum amount to %8, only Al oxide formed due to decreasing carbon potential of thealloy,homogenity of elemental concentration in matrix and no diffusion of oxygen through oxide–metalinterface,therefore it has superior oxidation resistance. Meanwhile,oxidation tests showed that the weight gain of thesteel at high temperature oxidation even at 1300ºC was too low.
A. Mohammadzadeh, A. Sabahi Namini, M. Azadbeh,
Volume 11, Issue 3 (september 2014)
Abstract
The rapidly solidified prealloyed alpha brass powder with a size range of 40 to 100 μm produced by water
atomization process was consolidated using liquid phase sintering process. The relationships between sintering
temperature, physic-mechanical properties and microstructural characteristics were investigated. Maximum
densification was obtained at 930 °C, under 600 MPa compacting pressure, with 60 min holding time. The
microstructure of the sintered brass was influenced by dezincification and structural coarsening during supersolidus
liquid phase sintering. As a consequence of Kirkendall effect atomic motion between Cu and Zn atoms caused to
dezincification at the grain boundaries and formation of ZnO particles on the pore surfaces. It was concluded that
microstructural analysis is in a well agreement with obtained physical and mechanical properties. Also, the amount of
liquid phase, which depends on sintering temperature, results in different load bearing cross section areas, and it
affects the type of fracture morphologies.
A. R. Amini, A. R. Zakeri, H. Sarpoolaky,
Volume 12, Issue 3 (September 2015)
Abstract
In this paper, the effect of MgO, BaO, Na
2
O and SrO addition to a pre-melted CaO-Al2O3
-Si
2
O synthetic
slag on sulfur removal from plain carbon steel was studied under the same experimental conditions. The slags were
pre-melted at 1400°C in an electric resistant furnace and desulfurization experiments were carried out in a high
frequency induction furnace. The results showed that the optimum reaction time for desulfurization was 15 min. It was
found that while SrO addition to the ternary slag enhances the sulfur removal capability, MgO, Na
2O and BaO
additions reduce desulfurization efficiency of the ternary slag. Moreover, it was observed that restricting access to
oxygen from the atmosphere by using a covered crucible, could increase desulfurization efficiency of the slag by more
than two fold
A. Qaed Amini Haroooni, H. Eskandari, M. H. Maddahy, I. Danaee,
Volume 12, Issue 4 (December 2015)
Abstract
The electrochemical behavior of 6063 aluminum alloy in ethylene glycol-water mixture was investigated by polarization curves and AC impedance measurements (EIS). The results obtained from polarization curves showed that corrosion rate decreased with increasing ethylene glycol concentration. EIS data showed the decrease in the interface capacitance which caused by adsorption of ethylene glycol at the surface of aluminum alloy. The cathodic current increased with the increase in rotating speeds of solution and the anodic current decreased. The effect of temperature was studied and the corrosion rate was increased with increasing the temperature. In addition, thermodynamic parameters were calculated in different ethylene glycol concentrations
