Sharif Digital Repository

Steady, laminar, natural-convection flow in the presence of a magnetic field in a porous cavity heated from left wall sinusoidally and cooled from right wall is considered. It is well known that unavoidable hydrodynamic movements can be damped with the help of a magnetic field. The Finite Volume method and SIMPLE algorithm for discretizing is used to solve the non-dimensional governing equations. The Convection and Diffusion term of the equations are discretized by Central Difference Scheme (CDS).The numerical procedure has been done over a range of Rayleigh number, Ra, and value of Hartmann number (Ha), 0 ≤ Ha ≤ 150 and effect of them is investigated on average and local Nusselt number.... 

Enhanced oil recovery (EOR) methods assisted by gravity drainage mechanism and application of sophisticated horizontal wells bring new hope for heavy oil extraction. Variety of thermal and non-thermal EOR techniques inject an external source of energy and materials such as steam, solvent vapor, or gas through a horizontal well at the top of the reservoir to reduce in-situ heavy oil viscosity. So, the diluted oil becomes mobile and flows downwards by gravity drainage to a horizontal producer located at the bottom of the reservoir. In this paper, a sector model of an Iranian fractured carbonate heavy oil reservoir was provided to simulate and evaluate capability of some EOR techniques such as... 

Solar and wind are two main resources of renewable energies that can supply the energy requirement in the most of world's regions. Iran has desirable condition in terms of solar and wind energy and also is faced with shortage of fresh water resources. Hybrid solar wind RO-MSF desalination system that works with two clean and renewable energy resources of solar and wind, could be a sustainable energy resource for water desalination. Hence, in this paper for evaluating the performance of salty water desalination by hybrid RO-MSF desalination plants, a hybrid system is designed and optimized. Different models of solar wind RO-MSF was considered and analyzed technically and economically. Finally... 

In this study, in order to compare effect of unidirectional compression and rolling on final microstructure of strain induced melt activated (SIMA) A356 aluminum alloy, rectangular samples with dimensions of 3cm×5cm in area and 1cm in thickness and cylindrical specimens with 2.5cm in diameter and 1cm in length, have been prepared for rolling and compressing processes, respectively. Then, these samples were plastically deformed at a same strain in ambient temperature. Afterward, the strained samples were cut into equal quarters. In the next stage, to produce globular microstructure, these specimens were partially remelted in 580°C for different times. Results obtained from light microscopy... 

In this work, effective parameters of SIMA process to obtain non dendritic microstructure in A356 alloy were investigated. In addition, the effect of SIMA process on the evolution of morphology of silicon and intermetallic phases in this alloy was studied. Microstructure images obtained from optical microscopy and SEM observation showed that increase in plastic work up to 40% and then holding of samples in the semi solid state at temperature of 580°C, causes that primary dendritic structure changes to non dendritic, fine and globular structure, but optimum reheating time completely depended on initial thickness of samples. If all parameters of SIMA process are the same, the grain boundaries... 

Since the advent of blockchain technology (BT), extensive research has explored using this technology in non-financial cases. The healthcare industry is one of the non-financial sectors that BT has significantly impacted. In this paper, for the first time, barriers to implement BT-based platforms from a balanced scorecard perspective in the healthcare sector are introduced, and these barriers are prioritized using a structural approach based on the weighted influence non-linear gauge system. Unlike other structural models such as decision-making trial and evaluation laboratory (DEMATEL), in this approach, both strength and influence intensity of components are considered in the ranking... 

Since the advent of blockchain technology (BT), extensive research has explored using this technology in non-financial cases. The healthcare industry is one of the non-financial sectors that BT has significantly impacted. In this paper, for the first time, barriers to implement BT-based platforms from a balanced scorecard perspective in the healthcare sector are introduced, and these barriers are prioritized using a structural approach based on the weighted influence non-linear gauge system. Unlike other structural models such as decision-making trial and evaluation laboratory (DEMATEL), in this approach, both strength and influence intensity of components are considered in the ranking... 

Recently, the problem of resilience of distribution networks against high impact low probability (HILP) events (i.e. hurricane) has been raised as one of the newest challenges discussed by engineers and researchers. On the other hand, the transformation of traditional electricity distribution systems into smart networks that have the ability to automatically perform switching and fault locating could enable the utilities to minimize the operational costs in case of HILP events occurrences. In this paper, while presenting a model for hurricane incidence, the impact of the automation system on network resilience has been investigated. Accordingly, a modeling scheme is first developed to... 

As in many other methods that have integrated nanoparticles (NPs), the chemical nose/tongue strategy has also progressed greatly since the entrance of NPs into this field. The fascinating tunable physicochemical properties of NPs have made them powerful candidates for array-based sensing platforms and have enabled the development of real-time, sensitive and portable systems that are able to target complex mixtures of analytes. In particular, the unique optical properties of NPs have a key role in providing promising array-based sensing approaches. This review will describe the main aspects and processes of most common NP-based optical sensor arrays. The fundamental steps in the design of a... 

Lake Urmia (LU) once was the second largest hypersaline lake in the world, covering up to 6000 km2, but has undergone catastrophic desiccation in recent years resulting in loss of 90% of its area and extensive coverage by playas and marshlands that represent a source of salt and dust. This study examines daily Aerosol Optical Depth (AOD) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) between 2001 and 2015 over northwestern Iran, which encompasses LU. Intriguingly, salt emissions from the LU surface associated with ongoing desiccation do not drive the study region's AOD profile, whereas pollution transported from other regions and emissions around LU are more important....