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Synthesis and Experimental Study of Organic-Metal Framework (MOF) Nanophotocatalists with Antibacterial Properties
, M.Sc. Thesis Sharif University of Technology ; Vossoughi, Manouchehr (Supervisor) ; Abdi, Jafar (Co-Supervisor)
Abstract
MOFs are new class of materials that are used in different scientific fields because of their hybrid structure. In this project, focused on two specific applications, and aim is synthesis of a nanostructure which has antibacterial and photocatalytic activity. ZIF-8 because of its chemical and physical stability has been studied. For improving antibacterial influence and photocatalytic activity, silver nanoparticles are added to the structure. Magnetic nanoparticles covered by silica were used as core to facilitate separation process, ZIF-8 structure was constructed as shell on SiO2@Fe2O3 nano spheres. Magnetic nanoparticles improving stability of ZIF-8 in aqueous solutions. Synthetic nano...
Ag-doped magnetic metal organic framework as a novel nanostructured material for highly efficient antibacterial activity
, Article Environmental Research ; Volume 188 , 2020 ; Abdi, J ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
Academic Press Inc
2020
Abstract
In the last decades, numerous attempts have been made to prevent microbial pollution spreading, using antibacterial agents. Zeolitic imidazolate framework-8 (ZIF-8) belongs to a subgroup of metal organic frameworks (MOFs) merits of attention due to the zinc ion clusters and its effective antibacterial activity. In this work, Ag-doped magnetic microporous γ-Fe2O3@SiO2@ZIF-8-Ag (FSZ-Ag) was successfully synthesized by a facile methodology in room temperature and used as an antibacterial agent against the growth of the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Several characterization methods were applied to analyze the properties of the materials, and the...
Enhancement of pool boiling heat transfer using ferromagnetic beads in a variable magnetic field
, Article Applied Thermal Engineering ; Volume 164 , 2020 ; Ebrahimi Dehshali, M ; Hakkaki Fard, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The pool boiling is one of the heat transfer mechanisms used in cooling systems. Using an external force to improve the efficiency of thermo-fluid systems is among the most effective approaches, and also highly applicable in enhancing heat transfer. In this study, the pool boiling of water, as the working fluid, in the presence of a variable magnetic field, is studied. To this end, ferromagnetic beads were placed on the boiling surface, and the effect of their movements due to a variable magnetic field was observed and measured. The number of beads was selected such that they would cover 1/3, 1/2 and 2/3 of the surface in different cases and the magnetic field was controlled by altering...
What do one hundred million transactions tell us about demand elasticity of gasoline?
, Article Empirical Economics ; Volume 62, Issue 6 , 2022 , Pages 2693-2711 ; 03777332 (ISSN) ; Tavakoli, A. H ; Rahmati, M. H ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
The price elasticity of gasoline demand is a key parameter in evaluation of various policies. However, most of the literature uses aggregate data to identify this elasticity. Temporal and spatial aggregation make such elasticity estimates biased. We employ a unique dataset of all gasoline transactions in Iran during a 4-month period around an unexpected exogenous price change to identify that price elasticity. We also identify a significant withholding behavior by consumers in response to anticipated price changes. The consumers reduce or postpone their purchases when they expect a decrease in prices. Controlling for date fixed effects would eliminate homogeneous withholding responses....
Unilateral Market Power; Evidences from Iran Wholesale Electricity Market
, M.Sc. Thesis Sharif University of Technology ; Fatemi Ardestani, Farshad (Supervisor)
Abstract
In the early 21st century, Iran established its wholesale electricity market as part of the restructuring of the power industry. Currently, the majority of electricity trades occur in this market. The simultaneous production and consumption of electricity, along with constraints for new companies to enter the market, make exercising market power a significant consideration in the economics literature. The market mechanism is based on auctions and is supported by a rich-data environment that allows for monitoring of production firms' behavior. This research measures the exercise of unilateral market power in Iran's wholesale electricity market using three months' worth of data for each year...
Inflationary Permanent and Long-Term Positive Interest Rate Shocks
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
Co-movement between inflation and nominal interest in response to an interest rate shock, dubbed neo-fisherianism, has been the subject of contentious debate since the advent of non-inflationary ZLB environment. We design an economic model rich with banking features to understand the economic responses to permanent and long-term interest rate shocks. We find that responses to a permanent positive interest rate shock depend on the monetary authorities’ speculation of the new long-term inflation rate, with the most probable outcome being a permanent increase in inflation. Responses to a long-term positive interest rate shock depict an increase and then decrease in inflation. We also discover...
A modified differential evolution optimization algorithm with random localization for generation of best-guess properties in history matching
, Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 33, Issue 9 , Feb , 2011 , Pages 845-858 ; 15567036 (ISSN) ; Nouri, A ; Pishvaie, M. R ; Bozorgmehri, R ; Sharif University of Technology
2011
Abstract
Computer aided history matching techniques are increasingly playing a role in reservoir characterization. This article describes the implementation of a differential evolution optimization algorithm to carry out reservoir characterization by conditioning the reservoir simulation model to production data (history matching). We enhanced the differential evolution algorithm and developed the modified differential evolution optimization method with random localization. The proposed technique is simple-structured, robust, and computationally efficient. We also investigated the convergence characteristics of the algorithm in some synthetic oil reservoirs. In addition, the proposed method is...
The Study of Eliminating Gender Gap in Iran Labor Market on Participation Rate of Married Urban Women
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Joshaghani, Hossein (Supervisor)
Abstract
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...
Estimating Welfare Effects of Rationed Good
, M.Sc. Thesis Sharif University of Technology ; Vesal, Mohammad (Supervisor) ; Rahmati, Mohammad Hossein (Co-Supervisor)
Abstract
Assuring households’ access to essential goods at economy’s hard times has always been of policymakers’ main concerns. Using Household’s Income and Expenditure Survey data during Iran-Iraq war during 80’s, we have calculated welfare and distribution effects of rationing by coupons of three essential goods in these years. We found that rationed quantities were inefficiently excessive and due to their significant low prices, they were overconsumed. Also, without any extra financial burden, government could have improved lowest income quantile’s aggregate utility by 5.2% or 5.6%, if cash subsidy equal to each household’s previous subsidy value or an equal per-capita subsidy were distributed...
Development of bioreactors for comparative study of natural attenuation, biostimulation, and bioaugmentation of petroleum-hydrocarbon contaminated soil
, Article Journal of Hazardous Materials ; Volume 342 , 2018 , Pages 270-278 ; 03043894 (ISSN) ; Kariminia, H. R ; Rahmati, M ; Fazlollahi, F ; Polasko, A ; Mahendra, S ; Wilding, W. V ; Fletcher, T. H ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Bioremediation of soil and groundwater sites contaminated by petroleum hydrocarbons is known as a technically viable, cost-effective, and environmentally sustainable technology. The purpose of this study is to investigate laboratory-scale bioremediation of petroleum-hydrocarbon contaminated soil through development of eight bioreactors, two bioreactors for each bioremediation mode. The modes were: (1) natural attenuation (NA); (2) biostimulation (BS) with oxygen and nutrients; (3) bioaugmentation (BA) with hydrocarbon degrading isolates; (4) a combination of biostimulation and bioaugmentation (BS-BA). Total petroleum hydrocarbons (TPH) mass balance over the bioreactors showed about 2% of...
Estimating The Demand of Freeways in Iran, Using Discreet Choice Model
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
According to the principle No. 44 of the Constitution of the Islamic Republic of Iran, Roads are in the public domain and are at the discretion of the Government. The result of this rule is that there is always a free route on the side of the freeway and motorists have the right to choose between a freeway and its successor road. This is a perfect laboratory condition which gives the opportunity that can be used with discrete choice models to estimate the demand of freeway versus its successor. In this paper we estimate the determinant parameters of the freeway demand versus the successor road and price elasticity of demand that can be calculated separately for each path. The results show...
Characteristics of Stocks that Frequently Hit Price Limits: Empirical Evidence from Tehran Stock Exchange (TSE)
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Co-Advisor)
Abstract
Price limits are boundaries established by market regulators to confine daily movements of security prices within a predetermined price range. In this study, we have used the data of trades of all companies listed in the Tehran Stock Exchange during the years 1385-1393 to study the characteristics of stocks that hit price limits repeatedly using a panel regression model with fixed effects and the generalized method of moments (GMM). In fact, this study aims at investigating the price limits in Tehran Stock Exchange by a novel and distinct approach. In general, risky stocks exhibit more price volatility and thus are more likely to experience price-limit hits. In summary, the results reveal...
Study of the Baby Boom in Iran
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
This paper studies the impact of the revolution on a rise in the rate of marriage and baby boom in the late 1980’s. The key factors that incentivize doing research in this area are manifold—three of which, however, are of great importance: first, the answer to this research question is still a matter of debate; Second, the number of studies in the case of Iran is insufficient; Third, the well-known theoretical models developed in non-Iranian cases are not compatible with the case of Iran. Our research hypothesis is based on the fact that during a period before and after the revolution, people were tremendously involved in the unstable political situation and, therefore no matter what...
Testing for Asymmetric Information in Automobile Insurance Market (Case Study of an Iranian Insurance Company)
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
Presence of asymmetric information is an important source of reducing insurance companies’ efficiency and increasing damage to premium ratio. In this research, we test the conditional independence of the choice of better coverage and the occurance of an accident, where “conditional” means conditional on all variables observed by the insurer. We use two parametric methods: a pair of probits and a bivariate probit model. The data includes 178390 third party and 46633 hull policies and their damage data for individual automobiles during 2013 to 2016 which covers all observations of the insurance company. Both third party and hull insurance policies have the option of adding extra coverage, so...
Air Pollution Effects on Mortality
, M.Sc. Thesis Sharif University of Technology ; Rahmati, Mohammad Hossein (Supervisor) ; Vesal, Mohammad (Supervisor)
Abstract
In this paper evaluate the short-term effects of air pollution on the mortality rate caused by cardiovascular problems, respiratory problems, digestive problems and tumors and cancers. This is done by using daily mortality data of Tehran, Tabriz, Mashad, Shiraz, Ahwaz and Isfahan during the years 1390 to 1394, we also use daily measurements of pollutant levels including Carbon-monooxcide, Sulfure-dioxide, Oxides of Nitrogen, Ozone and Particulate matters in the same period. The effects are estimad by looking at the relation of daily mortality in each city along with its pollution level. By controling for the weather conditions and city and month fixed effects, we find significant positive...
Why Do Firms Bid Stepwise Rather Than Uniform in a Pay-as-bid
Electricity Market?
,
M.Sc. Thesis
Sharif University of Technology
;
Rahmati, Mohammd Hossein
(Supervisor)
;
Alishahi, Kasra
(Supervisor)
Abstract
Why firms does not submit several steps in their bids curve? In this paper, we present a mathematical model for the behavior of power plants in a Pay-as-Bid auction market. According to this model, in the case that the power plant has a fixed marginal cost, the optimal behavior for him is to offer only one price, but in the case of linear marginal cost, bidding one price is not an optimal price, and with increasing the slope of this function, the number of steps and their price level will increase. We also show that increasing the level of competition in the market will force the plants to lower the price level and the number of steps. The model of this paper also predicts the factors...
Household Electricity Demand Estimation: A Regression Discontinuity Design Approach
, M.Sc. Thesis Sharif University of Technology ; Vesal, Mohammad (Supervisor) ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
Estimating electricity demand elasticity in different sectors has been an essential research topic. Considering the fact that pricing electricity in various countries does not follow the same rules, many econometrics methods have been developed to estimate this crucial parameter. Electricity demand elasticity is defined as the percent change in electricity consumption in response to one percentage change in electricity price. Having a correct estimate of this parameter would help policymakers to price electricity properly in order to reach desirable goals in electricity consumption optimization and many other aspects of electricity consumption. In Iran, Tavanir Co. which is a subsidiary of...
Estimating Price Elasticity of Gasoline Demand Using Transaction-Level Data
, M.Sc. Thesis Sharif University of Technology ; Vesal, Mohammad (Supervisor) ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
One of the most widely discussed parameters in energy economics is the price elasticity of gasoline demand due to its substantial implications for taxation, energy efficiency, and environmental policies. This paper aims to estimate the price elasticity of gasoline demand using a novel source of data. The data is from Iran, in the early months of 2014. Vehicles get a quota of 60 liters per month as subsidized gasoline at a lower price. The quota is transferable to the next months if it has not been consumed. All of the information about each pumping transaction is gathered in a centralized database, assigning a unique fuel card to each vehicle. Consequently, the structure of the market provides...
PVP-PEG-BaTiO3 Hydrogels, Synthesis and Characterization for Medical Applications
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Dadbin, Susan (Supervisor)
Abstract
Today, hydrogels have various biomedical applications as three-dimensional networks with the ability to absorb and retain water and biological fluids. This study aimed to prepare nanocomposite hydrogels from polyvinyl pyrrolidone, polyethylene glycol, and barium titanate nanoparticles. Gamma radiation at irradiation doses of 25 and 35 kGy was used as the hydrogel's crosslinking agent. The effects of gamma irradiation dose, percentage of polyethylene glycol, and barium titanate composition on the swelling ratio and gel content were investigated. It was observed that the amount of gel content with the addition of polyethylene glycol and barium titanate nanoparticles reduces the gel content and...
The Effects of Rural Roads on Farmland Rental Rates in Iran
, M.Sc. Thesis Sharif University of Technology ; Vesal, Mohammad (Supervisor) ; Rahmati, Mohammad Hossein (Supervisor)
Abstract
What is the effect of access to paved roads on farmland rental rates? To answer this question, I estimate the impact of the increase in the share of people in counties that access asphalt roads on irrigated farmland rental rents between 2006 and 2011 in Iran. For this analysis, I construct a county-level panel dataset by combining 2006 and 2011 Iranian census and agricultural data on cropland as well as farmland rental rates and exploit a fixed effects approach. I show that the availability of rural asphalt roads, rural sanded roads, and railroad stations increased irrigated farmland rental rates by 3.4 percent, 4.0 percent, and 1.6 percent, respectively. I also show that the effect of...