Sharif Digital Repository

This research deals with one of the current issues in the world and in Iran, which is named the field of cryptocurrencies. Domain that is managed decentrally due to the use of blockchain platform. This decentralization has caused different challenges (security problems, disruption of economic governance, etc.) for governments and has created different advantages and disadvantages for each country. This study seeks to investigate how Iran is facing the challenges in the field of cryptocurrencies. In this research, three main questions have been asked to determine the situation of Iran in the field of cryptocurrencies. In the first question, what are the policies of Iran is questioned and then... 

This research deals with one of the current issues in the world and in Iran which is called the field of cryptocurrencies. This research has tried to map the situation of cryptocurrencies in the world and then the situation of Iran in this field.In order to understand the situation of Iran in the field of cryptocurrencies, three main questions have been defined. The Questions that first express the nature of Iran's policies and then determine the position of these policies in relation to the conceptual framework, and then it will discover the reason of the adoption of these policies in Iran.Therefore, this research has an exploratory approach and its research method is qualitative. In order... 

Renewable energy deployment through distributed energy resources is among the central goals of future power systems. Microgrids have proven to be an economically viable soloution for distributed energy resources integration into power system and benefit the customers with uninterrupted power supply. In this context provisional microgrids have been introduced with the main goal of rapid renewable energy sources deployment. Since a considerable portion of renewable enegy resources as well as residential loads are DC and this portion is expected to grow even further, hybrid AC/DC design of provisional microgrids can improve both efficiency and economic benefit by optimal arrangement of AC/DC... 

In this thesis the calculated dose by corePLAN treatment planning software is compared with the calculated dose from combining BEAMnrc and DOSXYZnrc Monte Carlo codes. First Varian Clinic 2100c/d linear accelerator was simulated and modeling parameters such as electron beam energy and its spatial distribution FWHM were tuned in order for PDD and dose profile curves to have an agreement with less than 2% error with the ion chamber dosimetry. In the second section the derived X-ray beams from the accelerator head simulations were used to calculate dose in different organs of a RANDO phantom. The female RANDO phantom was simulated based on its CT data using DOSXYZnrc code. The CT files of the... 

Since the classical continuum theory fails to deal with the problems associated with defects, stress concentrators, and relevant deformation phenomena in solids, alternative approaches that can detect the atomistic nature of materials' fracture are required. The deficiency of the capture the size effect which yields delusively high values for some components of the stress field right on the edge of the stress concentrators, and its weakness in describing the complex interaction between small inhomogeneities, cracks and the like when they are only a few nanometers apart, are among some of the disadvantages of the classical approach. In recent years, however, atomistic methods are emerging to... 

Aluminum Bronzes have many applications in marine environments. These alloys suffer from both hot cracking and cold cracking. In order to overcome the hot cracking and cold cracking, Semisolid Stir Joining method and a proper thermal cycle was used respectively. Effects of temperature, stirring rate, and tool type were investigated in Semisolid Stir joining method. In this method, butt joint design was used in order to place specimens, and the specimens were heated up to specific temperatures (920, 925, 930°C). A stirrer (Cylindrical and Grooved tool) with three rotational speeds (800, 1200, 1600 RPM) was introduced into the stir weld seam. Welded specimens were cooled to the 900°C... 

The low female labor force participation rate in the Iranian labor market relative to the global average and even to countries that do not differ significantly from the socio-economic characteristics of our country is one of the important questions of the Iranian labor market. In this study, we seek to answer the question of whether the economic participation rate of married women will increase if the gender gaps in wages, job findings and job losses among women and men are eliminated in the Iranian labor market. To answer this question using household expenditure and income data and labor force data, we show that between the two categories of occupations, in terms of the share of women's... 

Shot peening is a cold-working process commonly used in industry to improve the fatigue performance, stress corrosion resistance and surface nano-crystallization of metallic parts. This process extends fatigue life via two mechanisms: Preventing the crack growth due to compressive residual stresses and, preventing the crack initiation because of increased material hardness. These mechanisms are the results of the bombardment of the component's surface with small spherical particles. In this research, an analytical model is developed for estimating the residual stress distribution induced by shot peening process. The modifications of the developed analytical model are related to...