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    Sustainable Usage of Fly ash as Stabilizer in Rammed Earth Structures

    , M.Sc. Thesis Sharif University of Technology Kosari Movahhed, Mohammad Hossein (Author) ; Toufigh, Vahab (Supervisor)
    Abstract
    Rammed earth (RE) is an eco-friendly building material and has been capturing special attention among researchers. Many of the recently studied RE additives are extremely resource- and energy-consuming. On the other hand, the usage of fly ash (FA), which is a sustainable replacement for cement, has been scarcely investigated in RE construction. In this paper, an experimental investigation was performed on the physical and mechanical properties of RE materials stabilized with the combination of cement and alkali-activated FA. This scrutiny consists of density measurements, pulse velocity tests, unconfined compression tests, and direct shear tests. Additionally, the carbon dioxide emission and... 

    Designing of Integrated Polygeneration System of Heating, Power and Carbon Dioxide in Urban Wastewater Treatment Plants

    , M.Sc. Thesis Sharif University of Technology Movahhed, Paria (Author) ; Avami, Akram (Supervisor)
    Abstract
    With the growing development of urban communities and population, the demand for water and treated sewage water has grown significantly. The environmental damage of polluted water has resulted in passing of new and strict environmental laws on wastewater discharge recently. In the present research, a hybrid system involving a power, heat and cool cogeneration and a carbon dioxide capture system has been designed for a typical wastewater treatment plant. The plant is optimized from economic and environmental criteria. The anaerobic digester is modeled using the ADM1 model. The biogas is directed into the hydrogen sulfide removal filter to remove the impurities and into the heat exchanger to... 

    Fluoride ions removal using yttrium alginate biocomposite from an aqueous solution

    , Article International Journal of Engineering, Transactions A: Basics ; Volume 30, Issue 1 , 2017 , Pages 1-6 ; 17281431 (ISSN) Kosari, M ; Sepehrian, H ; Sharif University of Technology
    Materials and Energy Research Center  2017
    Abstract
    Removal of fluoride ions was investigated using a new adsorbent of yttrium alginate biocomposite (YALG). Effect of various parameters such as pH, contact time, initial concentration of fluoride ions and temperature on the sorption capacity of adsorbent was studied. Performing a mathematical assessment of fluoride sorption, isotherm and kinetics models including Freundlich & Langmuir isotherms and pseudo first & second order kinetics were applied on experimental equilibrium results through this work. Isotherm analysis revealed that Langmuir model showed a better evaluation from sorption equilibrium data than Freundlich. Based on kinetics evaluation, the pseudo second-order equation was... 

    Design of LQG/LTR controller for attitude control of geostationary satellite using reaction wheels

    , Article 2013 9th IEEE Vehicle Power and Propulsion Conference, IEEE VPPC 2013 ; N: 6671729 , 2013 , Pages 411-415 ; 9781479907205 (ISBN) Kosari, A ; Peyrovani, M ; Fakoor, M ; Pishkenari, H. N
    IEEE Computer Society  2013
    Abstract
    In this paper, LQG/LTR controller is designed for attitude control of the geostationary satellite at nominal mode. Usage actuator is the reaction wheel and control torque is determined by the LQR regulator. LQR controller signal has good performance, if all states are considered in feedback, but does not include model and sensors noises. Usage sensors are sun and earth sensors and EKF is used for estimation of noisy states. Then, LQG and LQG/LTR controllers are designed based on the estimated states, and are compared with LQR controller. The results show that robustness and performance of LQG/LTR are better than LQG and its control overshoot is smaller than LQR. The term that is provided in... 

    Introducing a method for calculating water saturation in a carbonate gas reservoir

    , Article Journal of Natural Gas Science and Engineering ; Volume 70 , 2019 ; 18755100 (ISSN) Movahhed, A ; Nabi Bidhendi, M ; Masihi, M ; Emamzadeh, A ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Cementation factor greatly affects water saturation estimation. Factors such as depositional environment, diagenesis and depositional architecture make the estimation of water saturation a big challenge in carbonate reservoirs. The current study is introduced a method for calculating cementation factor in Archie formula. First, (MRGC) technique was applied on the (NMR) logging parameters along with (NDS) data to obtain the optimum number of clustering. After that, fuzzy logic method was applied on conventional log parameters obtained from the wells without any NMR log data. In the third part of the study, a novel crossplot introduced including compressional to shear-wave velocity ratio... 

    The Study of Eliminating Gender Gap in Iran Labor Market on Participation Rate of Married Urban Women

    , M.Sc. Thesis Sharif University of Technology Asghari, Fatemeh (Author) ; 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... 

    Crack Detection in a Rotor using Traditional Mode Shape Based Modal Analysis Methods and Experimental Evaluation

    , M.Sc. Thesis Sharif University of Technology Ashtiani, Mohammad Reza (Author) ; Mohammad Navazi, Hossein (Supervisor)
    Abstract
    Fatigue crack growth can have harmful effects on the reliability rotary machine. While an early warning to crack, can be used to extend the life of these expensive machines and increase reliability.Structural Vibration Condition Monitoring as a primary fault detection method, achieved to a lot amazing result and for this reason studies vibration behavior of cracked rotational shaft is a big issue for engineers of dynamic machine.In this research, first check the fault detection methods based on structural vibration condition monitoring, mode shape methods were extracted. Then by modeling rotational shaft in computer and creation of crack on it, fault detection quality of these methods have... 

    Investigating and Analyzing the Optimal Method for Construction of Keshavarz Metro Station on Line Three of Esfahan Urban Railway

    , M.Sc. Thesis Sharif University of Technology Torabi Ziaratgahi, Mohammad Ali (Author) ; Sadaghiani, Mohammad Hossein (Supervisor)
    Abstract
    It is important to provide an appropriate and economically method with technical and engineering considerations to stabilize excavated underground spaces. The necessity of this, especially for the construction of underground metro stations located in the cities which faces many problems, is more evident. In this research, it has been tried to introduce an optimal method according to the type of area for the construction of the underground station. In order to obtain stress and strain condition in structural elements and surface deformations due to different stages of excavating, numerical modeling in FLAC3D has been used. By examining the parameters that affect the sustainability of this... 

    The Effect of Increasing The Value of Natural Gas Production on Property Value, Wages, Unemployment Rate and Birth Rate in The United States of America (2000-2011)

    , M.Sc. Thesis Sharif University of Technology Asgari, Mohammad Hossein (Author) ; Rahmati, Mohammad Hossein (Supervisor)
    Abstract
    In the present study, the effects of increasing the value of shale gas production, either due to increased production or price increases, have been studied on economic variables such as employment, wage, property value and the number of births. In this regard, the data for each of these variables was used at the county level in the United States of America between 2000 and 2011. In order to estimate the desired effects, counties are divided into two types of boom and non-boom counties. The findings indicate that increasing natural gas production will lead to more employment and wage growth in boom counties than non-boom counties. Also, during the period of increasing production, the value of... 

    Inflationary Permanent and Long-Term Positive Interest Rate Shocks

    , M.Sc. Thesis Sharif University of Technology Ahmadian, Mohammad Hesam (Author) ; 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... 

    Learning Interpretable Representation of Drugs based on Microscopy Images

    , M.Sc. Thesis Sharif University of Technology Sanian, Mohammad Vali (Author) ; Rohban, Mohammad Hossein (Supervisor)
    Abstract
    In this study, we aim to learn representations from microscopic cell images that effectively capture the features of drugs affecting the cells, allowing us to identify effective drugs for treating a disease. We employ two parallel learning paths using predictive and generative models. Specifically, we have achieved a predictive model on the RxRx19a dataset that, unlike previous models, is interpretable, optimized, and robust to dras- tic changes in drug properties. Additionally, we have developed the first generative model on this dataset, which not only generates high-quality images but also discovers a meaningful latent space. This latent space divides the representation into relevant... 

    A new model for robust facility layout problem [electronic resource]

    , Article Information Sciences, Elsevier ; Volume 278, 10 September 2014, Pages 498–509 Neghabi, H. (Hossein) ; Eshghi, Kourosh ; Salmani, Mohammad Hassan ; Sharif University of Technology
    Abstract
    The Facility Layout Problem (FLP) is the problem of locating each department in a long plant floor without any overlap between departments in order to minimize the material handling cost. The main purpose of this study is to show the effectiveness of a robust approach to solve FLP. In this study, it is assumed that the departments’ length and width are not predetermined. For modeling this kind of uncertainty, the size of each department is considered as a bounded variable and two new parameters are also introduced to implement a robust approach. Moreover, a new adaptive algorithm is designed to determine the robust layout with respect to the decision makers’ requirements. Furthermore, the... 

    Interaction of Parallel Tunnels; Case Study: Interaction of Towhid Tunnel and Tehran Metro line 7 Tunnel

    , M.Sc. Thesis Sharif University of Technology Mirhadi, Nima (Author) ; Sadaghiani, Mohammad Hossein (Supervisor)
    Abstract
    Influence of excavating the Tehran metro line 7 tunnel on surface settlement, stresses and deformations induced in Towhid tunnel is investigated using numerical modeling. Construction of Metro tunnel as the new one must be carried out without imposing any damage to the Towhid tunnel as the existing tunnel. Towhid tunnel is a set of twin tunnels along the Chamran highway in Tehran. The tunnels were constructed using sequential excavation method and lined with cast in place reinforced concrete; on the other side metro line 7 is being constructed using 2 EPB tunnel boring machines and lined with reinforced concrete segments. This research consists of the study of the effects of pillar width,... 

    Pore-Scale Experimental Study of Foam/Nano-Foam Flooding to Heavy oil in Heterogeneous Five-Spot System: Stability Analysis and Displacement Mechanisms

    , M.Sc. Thesis Sharif University of Technology Suleymani, Mohammad (Author) ; Ghazanfari, Mohammad Hossein (Supervisor)
    Abstract
    Foam injection for enhanced oil recovery is concerned by petroleum engineers because it decreases adverse effects of fingering and gravity segregation caused by the injected fluid .Obviously foam stability is an important factor in the efficiency of this process. So investigating it is an imperative. One of the ways that less studied and can improve foam stability is using of nanoparticles. In this project effect of nanoparticles on foam stability and displacement mechanism during foam flooding has been discussed.
    Study consisted of two sets of experiments. In the first part, the static foam stability in the presence of silica nanoparticles has been investigated. Also influence of... 

    Modeling and Simulation of Miscible Flow through Fractured Porous Media Using Random Walk Method

    , M.Sc. Thesis Sharif University of Technology Fayazi, Amir (Author) ; Ghazanfari, Mohammad Hossein (Supervisor)
    Abstract
    Miscible displacement in fluid flowing through a porous medium plays an important role in many environmental and industrial applications; for instance, miscible displacements in enhanced oil recovery processes and pollutant spreading in groundwater. A large number of numerical approaches have been developed to solve the advection-dispersion equation that describes the behavior of miscible displacement in porous media. Most of these numerical models suffer from numerical dispersion. Random walk seems to be an effective method to overcome this problem especially in heterogeneous media. Here, a random walk model was developed and used for simulating miscible displacement in heterogeneous porous... 

    Spherical Graphite Cast iron Production from Sponge Iron

    , M.Sc. Thesis Sharif University of Technology Hosseini, Mohammad Reza (Author) ; Ashuri, Hossein (Supervisor)
    Abstract
    Due to the increasing spread of metal industries and the need for raw material as feed for electric furnaces in order to produce cast iron and steel, as well as scrap deficiency and rising prices, the use of sponge iron as a substitute for scrap was considered in this project Therefore, in order to achieve the chemical analysis of the sorel ingot that is special for spherical graphite cast iron production with low manganese and chromium content, the direct reduction process was carried out using tunnel kiln method on low-manganese iron ore concentrate.After the investigation on direct reduction parameters including the saggers and coal grading,the produced sponge iron has melted in... 

    Non-stationary Vibration of a Rotor with Foil Gas Bearings Passing Through Critical Speeds

    , M.Sc. Thesis Sharif University of Technology khaji, Zahra (Author) ; Mohammad Navazi, Hossein (Supervisor)
    Abstract
    The use of air bearings was began the last decade. Oil-free air bearing technology is implemented in rotating machines such as turbines, Micro gas turbines and turbocharged, this technology has improved the efficiency of rotating systems. In rotating machines, at high speeds, passing through the critical speed happens. As a result, the natural frequency of the system is crossing the critical speed, which causes system instability and lack of system amplitude control. Instability causes damage to the system. The aim of this thesis is to investigate the nonstationary vibrations of a flexible rotor with air bearings in the passing critical speeds. Behavior of air bearings is also considered to... 

    Investigating the Effect of Household Budget Shocks on Household Religious Expenditures

    , M.Sc. Thesis Sharif University of Technology (Author) ; Rahmati, Mohammad Hossein (Supervisor)
    Abstract
    In Islam, a solar eclipse is considered a significant event and a sign of the power of Allah (God). During a solar eclipse, Muslims are encouraged to perform a specific prayer. In addition, it symbolizes and reminds believers of the Day of Judgment. The solar eclipse is an exogenous and predictable event with no daily life consequences. Therefore, the only channel that may affect religious spending is a spiritual reference to God. We find that a total solar eclipse within a past quarter significantly increases the likelihood of religious contributions by 2.44 percent, mainly driven by making vows and donating to holy shrines. It also increases the donation sizes and its share in total... 

    Parametric Analysis of Interaction Between Crossing Tunnel with Existing Metro Station at Different Levels

    , M.Sc. Thesis Sharif University of Technology Asgarpanah Soveiri, Mohammad Reza (Author) ; Sedghiani, Mohammad Hossein (Supervisor)
    Abstract
    The interaction of perpendicularly tunneling beneath existing metro station is investigated. In this paper E4R7 station, in line 7 of Tehran Metro (Tehran Urban and Suburban Railway co., TUSRC); Iran has been studied. This existing station has some special specifications such as a new pre-supporting system that is called Concrete Arch Pre-supporting System (CAPS). Construction of CAPS is mainly based on an Old Iranian small water tunnels excavation method, Quanat, which is faster and more economical than other common methods. CAPS is a rib like structure consisting of concrete piles and arch beams constructed around underground space before its construction. This method has been utilized in...