Sharif Digital Repository

The per capita income and welfare levels of countries around the world vary significantly from each other. Identifying the factors that lead to differences in the per capita income of countries as well as their welfare levels is a major concern for economists. Studies conducted in this field indicate that one of the main sources of these differences is the significant disparity in the total factor productivity (TFP) across countries. Suboptimal resource allocation is one of the most influential factors affecting TFP in countries. The primary importance of investigating misallocation in the Iranian economy is that, in line with the decrease in economic growth, the growth rate of industrial... 

Approximately, 60 percent of the world's populations are living at the distance of 60 kilometers of the coasts. In coastal zones, coastal aquifers are the most important resources of the available freshwater while expected that the short-term or long-term impacts of the climate changes threat such aquifers. In general, it is predicted that climate changes e.g. sea-level rise (SLR) cause to increase seawater intrusion (SWI) in the coastal aquifers. In this study, both continental and island coastal aquifers are considered. The objective of this research is the investigation of SWI behavior occurred in the coastal aquifers due to climatic change parameters and aquifer properties. For... 

Concrete has long been one of the most widely used materials in the world. Cement, as a major component of concrete, due to the use of fossil fuels in its production process, emitting greenhouse gases such as carbon dioxide, which cause air pollution and environmental issues such as climate change. On the other hand, the wastes of industrial factories such as slag of the Blast furnace, due to their large volume and lack of sufficient space for storage of these wastes, lead to the release of these wastes that have alkaline structures into enviroment, causing environmental pollution Such as embankment pollution. Alkali-activated concrete has prevented the release of these pollutant into the... 

In the banking and macro-financial literature، banks are modeled as financial intermediaries who give loans to the borrowers from their deposits. In these models، deposits are created from the accumulation of real goods. Besides this view، which is used more in the academic environment، others who are most practical، describe banks not intermediaries، but credit creator which do not need deposits to pay loans. In this research، we use credit creation concept in a Neoclassic environment that the central bank’s monetary policy is fractional reserve to answer this question that if banks could create credit for firms based on its future income، while firms have CIA constraints، how do economic... 

The financial depth in Iran has decreased since 2008 and simultaneously the interbank rate has increased. In addition, researches show that the bank health has decreased over the same period. This research investigates to find evidence for the existence of the relationship between the bank health indicators and its lending power. In this regard, the balance sheet data and financial statement data of the Iranian banks during 2007 to 2014 have been investigated and the effect of the bank health indicators on their lending power studied at the normal conditions and sanction periods. In this research like Kashyap and Stein 2000, and Gambacorta and Marques2011, the bank lending channel consider... 

Related Lending is defined as banks making loans to firms with which they have some kind of ownership association. On one hand, this practice can help diminish asymmetric information between bank and firm which results in a more efficient allocation of bank’s resources. On the other hand, it may lead to the banks’ transferring resources to their related firms inefficiently, without meticulously assessing the risks involved. This paper is focused on the effect of the relationship between bank and firm in their ownership structure, on the loan provision. I have gathered a unique dataset of private and privatized banks and also private firms active in Iran’s stock market, which covers the... 

In this thesis, behavior of multiple pool fires was investigated in the numerical method. Fire modeling is a complex process. The complexity intensify when simultaneous fires occurred, pool fire is the most likely among all kind of fires in city and industrial units. FDS software, a common CFD model for fire simulation, was used to simulate multiple pool fires. Using of CFD models is one of the most advanced techniques to fire simulation and FDS software have been used by engineers and researchers due to using of this technique. In the beginning, review of the existing investigations which FDS performance was examined of fire simulation is presented. Besides of the data gathering, in this... 

This research aimed to investigate the relationship between household poverty and the gender of the head in the Iranian households. The self-reported gender of the head of household (FHH), underestimates the rate of poverty in female- head households (FHH). The self-reported gender of the head of household considers, conventionally, a family as male-head, even if the man of the family is incapable of making money. In much of these families the wife is the sole income holder even though she is not recognized as the head. In this study, a definition for household headship is introduced, which considers head of household the one who provides more than 50% of household income. Using household’s... 

Nitroglycerine is an oily liquid and in pure form it is colorless. It is the main component of high explosives such as dynamites, and an essential ingredient of smokeless, double base propellants. The production of nitroglycerine has to solve the problems that arise from the extremely high mechanical sensitivity of the substance and the chemical instability of impure materials. Without sufficient control and mitigation of hazards, incidents have led to severe consequences, such as explosions, and threats to human lives, properties, and the environment. In this study, the hazard and operability study method is used to identify the existing hazards in the nitroglycerine production plant. Then,... 

Nowadays evolutionary algorithms help developers to solve many problems in applied science and engineering aspects. So the main goal of this thesis is to apply and verify the ability of evolutionary algorithms and artificial neural networks in optimization of Ethane recovery unit. Algorithms applied in this study are Ant Colony Algorithm, Artificial Immune Systems Algorithm, Incremental Evolutionary Algorithm, Chaotic Based Algorithm, Variable Population Size Genetic Algorithm, Frog Leaping Algorithm, Frog Leaping with Bacterial Optimization Approach and Different types of Particle Swarm Optimization Algorithm. Optimization methods based on local search are also applied in order to compare... 

Hazard analysis and risk assessment are the two significant methods of controlling and reducing risk caused by industrial units. To achieve the required safety needed in either new or operating plants, risk assessments are being used for some specific hazards such as fire, explosion and toxic release. Increasing industrial developments and occurrence of several catastrophic accidents in chemical processing plants have contributed to striking disasters and have obliged experts to use analytical solutions to evaluate frequencies and consequences of such events. Congested plants in industrial areas like Mahshahr and Asalouyeh in Iran and other places in the world are the reason why it has... 

Sour Gas is more dangerous than sweet gas because of its hydrogen sulfide contents. So it requires more safety considerations. In this project, the effect of wall thickness and design factor of pipeline on the safe distance was examined by using risk assessment method. The safe distance tables for 4 pipelines with different wall thicknesses and design factors were prepared based on operating pressure, pipe diameter and hydrogen sulfide concentration in gas by using PHAST and PHAST RISK softwares. In this project, the depth of cover parameter was considered in safe distance determination. Also the leak of sour gas was simulated by using... 

One of the most important stages to designing a process plant is layout of equipment in unit area. There are plenty of routine procedures to find out equipment arrangement and their separation distances based on process and cost criteria. Although some studies have been carried out to enter safety parameters to conventional procedures, the problem complexity because of the number of involved equipment is still of concern. To clear these ambiguities, the new approach presented in this thesis is aimed at quantifying the effects of adjacent equipment on each other. In this way, fire radiation and explosion have been selected as the major hazard that any equipment can expose on the other items,... 

In this project, ammonia dispersion in the environment have been investigated and the experimental data have been used in order to show accuracy of calculations. Also, the results of CFD have been compared with the results of PHAST software. The results show that when there is no obstacle in the way of gas release, dispersion models will get good results, but due to existence of the obstacle, their error will be increased to 300%. However, the error resulting from CFD is less than 24% even if there are obstacle there. The effects of obstacle’s distance and height on the dispersion of ammonia gas are investigated. This study showed that the concentration of ammonia increase, when the distance...