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Influence of different types of nano-SiO2 particles on properties of high-performance concrete
, Article Construction and Building Materials ; Volume 113 , 2016 , Pages 188-201 ; 09500618 (ISSN) ; Mobini, M. H ; Hosseini, P ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
The aim of this study was to evaluate the effects of applying low replacement ratios (0.75% and 1.50% of the binder weight) of nano-SiO2 particles with different specific surface areas (200 and 380 m2/g) on the properties of high-performance concrete (HPC). Mechanical (compressive and splitting tensile strengths), electrical resistivity, non-destructive (ultrasonic pulse velocity), and microstructural (mercury intrusion porosimetry, X-ray diffraction, and scanning electron microscopy) tests were conducted to investigate the macroscopic and microscopic effects of nano-SiO2 particles on HPC characteristics. The results indicated that the performance of nano-SiO2 particles significantly...
Effects of conventional, severe, over, and re-shot peening processes on the fatigue behavior of mild carbon steel
, Article Surface and Coatings Technology ; Volume 344 , 25 June , 2018 , Pages 62-74 ; 02578972 (ISSN) ; Unal, O ; Kashyzadeh, K. R ; Sharif University of Technology
Elsevier B.V
2018
Abstract
The present study investigates experimentally the effects of different shot peening treatments, including conventional, severe, over, and re-shot peening on microstructure, mechanical properties, and fatigue behavior of AISI 1050 mild carbon steel. Different shot peening treatments were performed using various effective parameters by considering the influences of increasing Almen intensity and coverage. Optical microscopy and field emission scanning electron microscopy observations and X-Ray diffraction measurements were carried out to analyze grains refinement in each shot peening treatment. Microhardness and residual stress measurements were taken from shot peened surfaces to the core...
Effect of precipitation hardening heat treatment on mechanical and microstructure features of dissimilar friction stir welded AA2024-T6 and AA6061-T6 alloys
, Article Journal of Manufacturing Processes ; Volume 31 , 2018 , Pages 214-220 ; 15266125 (ISSN) ; Jashnani, H. R ; Paidar, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The friction stir welding of AA2024-T6 to AA6061-T6 plates with a 4 mm thickness has been studied at constant traverse and rotational speeds of 1000 rpm and 100 mm/min, respectively. The position of alloys and the effects of precipitation hardening heat treatment in retreating and advancing side in the friction stir welding were analyzed. The tool with taper threaded pin was used for welding. Macro and microstructural analysis were investigated by using Optical and Field Emission-Scanning Electron Microscopes (FE-SEM) to check out the welded joints. Micro-hardness and Tensile tests were also done to study mechanical attributes of the joints. Microstructural analysis revealed some grain...
Effect of severe plastic deformation on evolution of intermetallic layer and mechanical properties of cold roll bonded Al-Steel bilayer sheets
, Article Journal of Materials Research and Technology ; Volume 9, Issue 5 , 2020 , Pages 11497-11508 ; Shadkam, A ; Kazeminezhad, M ; Sharif University of Technology
Elsevier Editora Ltda
2020
Abstract
In this study, evolution of intermetallic layer of the cold roll bonded bilayer of Aluminum-Steel sheets, during severe plastic deformation (SPD) followed by annealing has been investigated. The effect of such evolution on mechanical properties has been discussed. For this purpose, Constrained Groove Pressing (CGP) was used as a SPD process. Field emission scanning electron microscope equipped with energy dispersive spectroscopy and optical microscopy were used for examination of intermetallic compounds morphology and composition. Meanwhile, tensile properties of the bilayer sheets were evaluated. According to microstructural observations, continuous intermetallic layer was formed during...
Direct insights into the pore-scale mechanism of low-salinity waterflooding in carbonates using a novel calcite microfluidic chip
, Article Fuel ; Volume 260 , 15 January , 2020 ; Mahani, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
One of the key open questions in the area of low or controlled salinity water flooding (LSWF or CSWF) is how the observed oil recovery at macro-scale (e.g. Darcy or core-scale) can the explained and what underlying microscopic mechanisms drive it. Thus far, the micromodel investigation of LSWF has been limited to sandstones, remaining challenging to apply to carbonates. In this paper we aim to i) extend the capability to fabricate a novel calcite micromodel using Iceland spar calcite crystal, ii) investigate the pore-scale mechanisms leading to oil recovery from carbonates. A target crude oil-brine-rock (COBR) system was first selected. To screen potential brines which can produce...
Symmetry enhanced spin-Nernst effect in honeycomb antiferromagnetic transition metal trichalcogenide monolayers
, Article Physical Review B ; Volume 103, Issue 1 , 2021 ; 24699950 (ISSN) ; Hamdi, M ; Haddadi, F ; Khavasi, A ; Sadeghi, A ; Mohseni, S. M ; Sharif University of Technology
American Physical Society
2021
Abstract
We investigate systematically the spin-Nernst effect in Néel and zigzag ordered honeycomb antiferromagnets. Monolayers of transition-metal trichalcogenides, MnPSe3, MnPS3, and VPS3 show an antiferromagnetic Néel order while CrSiTe3, NiPS3, and NiPSe3 show an antiferromagnetic zigzag order. We extract the exchange and Dzyaloshinskii-Moriya interaction parameters from ab initio calculations. Using these parameters, we predict that the spin-Nernst coefficient is at least two orders of magnitude larger in zigzag compared to the Néel ordered antiferromagnets. We find that this enhancement relies on the large band splitting due to the symmetry of magnetic configuration in the zigzag order. Our...