Sharif Digital Repository

In recent years, utilization of hybrid attached and suspended growth system for modification of conventional activated sludge systems has attracted a lot of attentions. Nowadays, with development of urban areas and also introducing new emerging contaminants and as a result an increase in the influent loading of wastewater treatment facilities, the importance of upgrading and retrofitting available facilities have been highlighted. Conversion of Sequencing Batch Reactors to Sequencing Batch Biofilm Reactors is a viable solution for overcoming these problems. Eventhough several researches have been conducted on removal of different contaminants through these systems, the information about the... 

During recent years, thin-film solar cells based on chalcogenide light absorbers with CuInxGa1-xS(Se)2 compound have attracted considerable attraction due to their desirable band gaps and demonstrated high power conversion efficiencies. These solar cells are fabricated under two categories named as ‘substrate’ and ‘superstrate’, generally. The best reported energy conversion efficiency belongs to substrate type (sodalime glass/Mo/absorber layer/buffer layer/window layer) CIGS solar cells, most have been fabricated with vacuum processes. In spite of this, superstrate solar cells (transparent conducting oxide/blocking layer/buffer layer/absorber layer/back contact) provide easier and cheaper... 

In a counter current two phase flow systems that liquid flows downward due to gravity on the pipe wall and gas flows upward due to pressure gradient in the pipe core, Flooding and reversal Flooding are important phenomena. Flooding is beginning of velocity direction change of liquid from downward to upward that with zero axial velocity of liquid in interface, liquid is on verge of moving upward. When mass flow rate of liquid or gas increase, some part of liquid film are separated and enter the gas stream. With further increase in mass flow rate of liquid or gas in flooding point, reversal flooding occurs that cause to all liquid film flows upward. Flooding and reversal flooding phenomena are... 

In recent years, mobile social networks have largely been developed and gained considerable popularity. With the development of smartphones, the growth rate of users on mobile social networks has dramatically increased, with users constantly interacting and sharing their various private and public data. Such volume of information can be used for profitable purposes and may affect the users' privacy. However, due to the limitations of smartphones and the trivial and costly encryption, entrusting the encryption to the user, both for users and for the service provider will be challenging, thus, social network providers themselves take charge that can compromise the privacy. In this... 

In this thesis, with a review on policy simulation and economic reform analysis literature, we design a suitable method to analyze the effects of monetizing energy carriers subsidy on welfare criteria of Iranian households. The selected method is limited general equilibrium that needs demand estimates of goods, services and energy. In firs step,based on 13 years of data on “Iranian Households’ Expenditures and Income” surveys, data are provided as a pseudo-panel. Demand equations are estimated using “Seemingly Unrelated Regressions” for panel data, and elasticities are calculated. In the next step, we evaluated the equivalent variation and equivalent gain measures in each price scenarios.... 

This thesis finds evidence for the presence of adverse selection in the Iranian life insurance market. We use a unique dataset including more than one million policyholders’ profile information alongside their chosen life insurance coverage from the largest Iranian insurance company. Our results not only find evidence in support of adverse selection in this market, but also consider the magnitude of adverse selection relatively notable. Moreover, we found that in addition to the coverage, the other dimensions of contract could be the potential source of adverse selection. Particularly, we focused on the insurance duration and the payment method (monthly, annually, all-in-advance).... 

This thesis aim to the study of the effect of bank’s branching decisions on deposit market. Using panel data banks from Iran, we study effect of branching on market share and market size. In theoretical part, we assume that banks maximize discounted flow of the profits. We also assume that the banks take into account the reaction from rival banks in setting number of branches. Banks are assumed to expect the rival banks react by a lag of one period. In empirical part, in order to distinguish between aggregate market size effect and market share effect, we rewrite quantity of deposit in banks as the product of aggregate deposit and market share. We specify deposit market share function with... 

In the past few years mobile usage is increasing in Iran. Since mobile industry is growing and new innovations are presented, the competition between operators is rising. Although this competition has a great influence on the mobile demand for each operator, lack of the data of the all operators made us to use the data of one of the operators to investigate the demand. Based on the subscriber’s data of Hamrahe-Aval company, it has been introduced an estimation of a demand system for customers of this company by using AIDS model in this essay. This model includes three groups of services: sending short messages, calling to mobile numbers and calling to fixed numbers.
This study has two... 

The identification of the poor and the elimination of their poverty always has been the subject of discussion among researchers and policymakers. Today, most researchers consider poverty as a multidimensional phenomenon, and in addition to income indicator, it has indicators related to the level of knowledge, awareness, well-being and the health of individuals. The study of multidimensional poverty and the search for the discovery of its static and dynamic relationship with income-based poverty is the subject of this research. The analysis shows that both statically and dynamically, there is a substantial mismatch in the identification of the poor households according to these two... 

Since the mid-twentieth century, the issue of gender preference has always been of interest to economists. This preference is demonstrated by sex-selection methods such as differential stopping behavior and sex-selective abortion. While it is almost impossible to look directly into abortion behavior in Iran, due to religious beliefs and illegality, we can investigate gender preference by calculating to what extent parents adapt their fertility behavior to ensure the birth of preferred sex. For this purpose, we use “Households Income and Expenditure Survey of 2019” data from the Statistical Center of Iran. Our results indicate that when Iranian parents are deciding to have second child, they... 

The question of whether sex preferences are present in a certain country has long been of interest for economists and demographers. This study first investigates the existence of these preferences among Iranian parents. Next, if any preference are present, it turns to the task of inferring the quality of the observed preferences. There are two widely used methods for addressing these issues in the literature. The first method is to estimate a Logit model which relates the probability of a mother giving birth to a new child, to the sexes of her previous children. The second one is to estimate a Proportional Hazard model in order to investigate the relationship of the time interval between...