Loading...
Search for:
protective-layers
0.005 seconds
Seismic Isolation of Structures using Trench Barriers
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Ground vibration induced by human activity such as industrial activities, Blasting, in construction or deconstruction operation. Ground vibration reaches the troublesome limit for men. In the densely populated urban regions and buildings housing, ground vibration has to be strictly controlled. Many vibration reduction methods have been proposed.A metod of protecting structures from dynamic loads is using trench wich will be located between the dynamic sources and the protected structures. Inappropriate designing of trenches will reduce its effect. In this research the effect of trenches and their different properties, such as type of material, width, trench depth, soil bed type and distance...
A new structure to increase the photostability of CdTe quantum dot sensitized solar cells
, Article Journal of Physics D: Applied Physics ; Volume 44, Issue 4 , January , 2011 ; 00223727 (ISSN) ; Iraji zad, A ; Taghavinia, N ; Molaei, M ; Sharif University of Technology
2011
Abstract
In this paper a new cell structure is introduced to reduce the rate of CdTe corrosion in quantum dot sensitized solar cells (QDSSCs) using I -/I- 3 electrolyte. In this cell, one electrode is a titania nanorod that was sensitized with CdTe quantum dots as the working electrode. A thin gold layer is sputtered on the electrode to act as a protective layer against the I-/I- 3 corrosive electrolyte and to passivate the CdTe surface traps which are the main recombination centres in a QDSSC. In addition, a Schottky barrier formed at the interface of Au and CdTe prevents direct electron recombination from the CdTe conduction band with I- 3 ions. The mechanism of charge transfer and quantum dot...
Modelling of carbon dioxide corrosion of steel with iron carbonate precipitation
, Article Corrosion Engineering Science and Technology ; Volume 44, Issue 2 , 2009 , Pages 128-136 ; 1478422X (ISSN) ; Ghorbani, M ; Afshar, A ; Rahmaniyan, M ; Sharif University of Technology
2009
Abstract
Corrosion of mild steel in aqueous solutions containing carbon dioxide was modelled under condition that protective iron carbonate films formed on the steel surface. In this model, the film form on the steel surface due to precipitation of iron carbonate from saturated solution. The precipitation of iron carbonate produces a porous layer on the steel surface, reducing the diffusion of species toward the steel surface. If the precipitation rate is high, the porosity decreases and the mass transport becomes slower. Therefore, formation of protective layers on the steel surface reduces the corrosion rate. In this case, the corrosion processes are controlled with diffusion of species. The model...
A critical state constitutive model for the isotropic thermal compression of structured sand–bentonite buffers
, Article Indian Geotechnical Journal ; Volume 49, Issue 4 , 2019 , Pages 398-408 ; 09719555 (ISSN) ; Karimi, A. H ; Hamidi, A ; Ahmadi, M. M ; Sharif University of Technology
Springer
2019
Abstract
The sand–bentonite mixture is used as the buffer layer in nuclear waste disposals. The buffer layer, as a non-permeable protective layer, is generally exposed to temperature gradients and the long-term subjection to temperature results in creep and more intact structure for the layer. In the present study, thermally induced structure and its effects on the isotropic compression behavior and volume change behavior of buffer layer are evaluated. Thermal consolidation tests were conducted using a modified triaxial cell capable of handling temperatures up to 90 °C. In order to investigate the effects of thermal gradients on the behavior of the mixture, saturated specimens were cured at constant...
Effect of YSZ sol-gel coating on interaction of Crofer22 APU with sealing glass for solid oxide fuel/electrolysis cell
, Article Journal of Alloys and Compounds ; Volume 847 , 20 December , 2020 ; Nemati, A ; Faghihi Sani, M. A ; Fakouri Hasanabadi, M ; Abdoli, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Interactions between the metal interconnect and glass sealant in the solid oxide cells stack are critical to retaining the system integrity. To address this issue, in the current study, 8YSZ coating is applied on the Crofer22 APU steel via sol-gel and dip-coating method. Dense and continuous 8YSZ coatings are obtained on Crofer22 APU substrates. X-ray diffraction and Raman spectroscopy results show that both cubic and tetragonal structures of 8YSZ are formed. A glass-based sealing paste is applied on bare and 8YSZ coated Crofer22 APU steel. The interfacial compatibility and chemical stability of steel/glass and steel/8YSZ/glass joint couples are investigated using SEM and EDS line scan...
Anti-reflection and self-cleaning meso-porous TiO2 coatings as solar systems protective layer: Investigation of effect of porosity and roughness
, Article Optical Materials ; Volume 107 , 2020 ; Afshar, A ; Azadeh, M ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Anti-reflection and self-cleaning coatings on the glass substrate are used to improve the performance of solar systems. TiO2 are one of the most used semiconductors for this application. In this research meso-porous TiO2 coatings (that synthesized by the sol-gel process) with the various extent of porosity (using different concentrations of Pluronic F127, as pore-forming agent) have been investigated. The coating's thickness and porosity and anti-reflective properties were studied by FE-SEM and UV/VIS spectrometer (transmission spectra test), respectively. It was found that the use of F127 leads to the formation of pores smaller than 30 nm and increases the surface roughness from 1.5 (for...