Characterization of pulse reverse Ni-Mo coatings on Cu substrate

, Article Surface and Coatings Technology ; Vol. 238 , 2014 , pp. 158-164 ; ISSN: 02578972 Surani Yancheshmeh, H ; Ghorbani, M ; Sharif University of Technology

2014

Abstract

The effect of pulse reverse current (PRC) method on Ni-Mo coatings electroplated from chloride solution was investigated by various plating parameters such as plating duration, the anodic duty cycle, the anodic current density and the cathodic current density. By increasing the anodic duty cycle and anodic current density, the Mo content of coatings reached 68wt.% and 78wt.%, respectively at cathodic current densities of 500 and 300mAcm-2. The Mo content of coatings increases by the preferential dissolution of Ni on the anodic pulse and also by the replenishment of Mo complexes in the diffusion layer near the substrate surface during the anodic pulse. In comparison with the direct current...

Pulse Reverse Electrodeposition of Ni-Mo Alloy on Cu

, M.Sc. Thesis Sharif University of Technology Surani Yancheshmeh, Hooman (Author) ; Ghorbani, Mohammad (Supervisor)

Abstract

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)...

Entropy generation analysis of thermally developing forced convection in fluid-saturated porous medium

, Article Applied Mathematics and Mechanics (English Edition) ; Volume 29, Issue 2 , 2008 , Pages 229-237 ; 02534827 (ISSN) Hooman, K ; Ejlali, A ; Hooman, F ; Sharif University of Technology

2008

Abstract

Entropy generation for thermally developing forced convection in a porous medium bounded by two isothermal parallel plates is investigated analytically on the basis of the Darcy flow model where the viscous dissipation effects had also been taken into account. A parametric study showed that decreasing the group parameter and the Péclet number increases the entropy generation while for the Brinkman number the converse is true. Heatline visualization technique is applied with an emphasis on the Br < 0 case where there is somewhere that heat transfer changes direction at some streamwise location to the wall instead of its original direction, i.e., from the wall. © 2008 Editorial Committee of...

Entropy generation for forced convection in a porous channel with isoflux or isothermal walls

, Article International Journal of Exergy ; Volume 5, Issue 1 , 2008 , Pages 78-96 ; 17428297 (ISSN) Hooman, K ; Hooman, F ; Mohebpour, S. R ; Sharif University of Technology

Inderscience Publishers 2008

Abstract

A numerical study is reported to investigate the entropy generation due to forced convection in a parallel plate channel filled by a saturated porous medium. Two different thermal boundary conditions are considered being isoflux and isothermal walls. Effects of the Poclet number, the porous medium shape factor, the dimensionless temperature difference for isothermal walls, the dimensionless heat flux for isoflux walls, and the Brinkman number on the Bejan number as well as the local and average dimensionless entropy generation rate are examined. Copyright © 2008 Inderscience Enterprises Ltd

Reliability-based Evaluation and Calibration of Load Combinations for the Design of Steel Building Structures of Iran

, M.Sc. Thesis Sharif University of Technology Mahmoudkalayeh, Soheil (Author) ; Mahsuli, Mojtaba (Supervisor) ; Ghasemi, Hooman ($item.subfieldsMap.e)

Abstract

The objective of this thesis is to evaluate and calibrate design load combinations of steel building structures of Iran based on the reliability theory. The importance of this research stems from recognition that the design load combinations for steel structures in Section 6 of the National Building Code of Iran have been completely adopted from the ASCE/SEI 7-10 standard, whereas the factors that affect these load combinations differ in Iran from those of the United States. Examples are the difference in the construction industry economy, lower quality of here and the differences in probability distributions for the specifications of steel. Hence, the load combinations need to be calibrated...