Loading...
Search for:
nozari--mostafa
0.205 seconds
Total 186 records
Experimental Study of Flame Stability on a Reheat System
, M.Sc. Thesis Sharif University of Technology ; Farshchi, Mohammad (Supervisor)
Abstract
In conventional afterburning systems, the burnt products of the primary combustion enter the afterburning zone, where the fuel is injected and the mixture is ignited to form a flame which is stabilized by a flameholder.
The present experimental study focuses on concepts of afterburning and flame stability in a reheat system. For this purpose an afterburner setup is designed and manufactured. The setup comprises of two main regions; the preheating region and the reheat zone. Fuel used in preheater is LPG while jet fuel is injected in reheat zone. Through the tests the key parameters which are adjusted to be in similar ranges as the conventional afterburners are the oxygen amount of the...
The present experimental study focuses on concepts of afterburning and flame stability in a reheat system. For this purpose an afterburner setup is designed and manufactured. The setup comprises of two main regions; the preheating region and the reheat zone. Fuel used in preheater is LPG while jet fuel is injected in reheat zone. Through the tests the key parameters which are adjusted to be in similar ranges as the conventional afterburners are the oxygen amount of the...
Experimental Study on Erosion Control at Channel Junctions with Submerged Vanes
, M.Sc. Thesis Sharif University of Technology ; Jamali, Mirmosaddegh (Supervisor)
Abstract
In this study, the effect of submerged vanes on the bed erosion pattern at a 90° open-channel junction has been evaluated experimentally. In this study, 41 tests have been conducted in four different steps. In each test, the bed surface level has been measured at the end of 1st, 2nd and 24th hour. In the first step, the preliminary tests have been conducted. In this step, six different formations of submerged vanes have been selected and their performance has been evaluated and the most efficient formation, in the field of maximum scour depth reduction, has been selected. In the second step, six different formations of submerged vanes have been selected and their performance has been...
Stake Size Effect on Guilt Aversion in Psychological Games Master Thesis
,
M.Sc. Thesis
Sharif University of Technology
;
Talebian, Masoud
(Supervisor)
Abstract
Guilt aversion, the process of avoiding guilt, when guilt indicates the human sense which is present when they let down other's expectations. As the definition suggests, guilt is related to what one thinks of the others’ thoughts; i.e. the second-order beliefs. Incomplete information models of guilt aversion are the most reliable ones in the literature due to economic experiments. Based on these models, the dictator game and the trust game are applied to measure the degree of guilt aversion. In both the above psychological games, there are two players where Player A has the power to decide about the split of the money. We use the amount of transferred money to Player B is as a sign of guilt...
Dynamics of null hypersurfaces in general relativity
, Article General Relativity and Gravitation ; Volume 34, Issue 2 , 2002 , Pages 243-253 ; 00017701 (ISSN) ; Mansouri, R ; Sharif University of Technology
2002
Abstract
This paper shows how the structure and dynamics of a lightlike thin shell in general relativity can be obtained from a distributional approach
The methods of gluing manifolds in general relativity
, Article Journal of Mathematical Physics ; Volume 43, Issue 3 , 2002 , Pages 1519-1535 ; 00222488 (ISSN) ; Mansouri, R ; Sharif University of Technology
2002
Abstract
Some areas of modern theoretical physics such as modern cosmology contain different manifolds which must be glued together along a common boundary. These boundaries can be spacelike, timelike, or lightlike hypersurfaces. This paper shows how this gluing for different hypersurfaces is possible. Two different approaches are considered and the extent to which these approaches are equivalent are discussed. In particular, we will construct a distributional approach for dynamics of lightlike hypersurfaces in general relativity. Since Einstein's equations are nonlinear PDEs, for discontinuous metrics such as signature changing metrics, product of distributions are unavoidable. To glue two different...
Optimization of Xylitol Production
, M.Sc. Thesis Sharif University of Technology ; Alemzade, Iran (Supervisor)
Abstract
Xylitol is a sugar alcohol or polyol that has been used as a food additive and sweetening agent due to Its high sweetening power, anti-cariogenic properties and possibilities for use in diabetic food products, makes xylitol an attractive sucrose substitute in a wide variety of foods and beverages. Xylitol is a five carbon polyol or pentitol obtained by the hydrogenation of xylose. xylitol could be produced from xylose in rice seed coats medium by Saccharomyces cerevisiae. For xylitol production, S.cerevisiae was grown in preculture medium at 30°C and agitated at 120 rpm on a rotary platform shaker. The cells were harvested after 20hr, were centrifuged and transferred to the production...
Kinetic Study of Selective Catalytic Reduction of over a Cu/Zeolite Catalyst for Emission Control from Diesel Engines
, M.Sc. Thesis Sharif University of Technology ; Hamzehlouyan, Tayebeh (Supervisor)
Abstract
Urban air pollution has become a significant environmental concern in recent times. NOx recognized as a criterion pollutant, is especially problematic. In 2021, the Tehran Air Quality Control Company reported that the ambient concentration of NOx in Tehran was around 50 ppb, which surpasses both the initial and final targets recently established by the World Health Organization (40 ppb and 10 ppb, respectively). To control and predict NOx emissions from diesel engines, A detailed selective catalytic reduction (SCR) model has been developed to describe the global kinetic reactions within the catalyst. This model incorporates two types of sites for high- and low-temperature NH3...
Study of the Effect of Presence of Nano- Particles on the Mass Transfer and Hydrodynamics of Drops
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Goodarznia, Iraj (Supervisor)
Abstract
Regarding to the effect of nanoparticles on mass transfer and hydrodynamics characteristics, limited number of studiesavailableinthe literature.In this work, mass transfer performanceand hydrodynamic characteristics nanofluidshavebeeninvestigated in the liquid−liquid extraction process. The chemical system of toluene-acetic acid-water was used, and two Extraction columnswith diameter of 10cm and height of 55cm and 6 cm were designed. The drops were organic nanofluids containing silica nano-particles and carbon nano-tubes.Synthesized silica nanoparticles by sol-gel methods, were modified with Triethoxyoctylsilane and Polydimethylsiloxane as well as Carbon nano-tubes were modified with dodecyl...
Collision-free path planning of a novel reconfigurable mobile parallel mechanism
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 231, Issue 20 , 2017 , Pages 3728-3742 ; 09544062 (ISSN) ; Tale Masouleh, M ; Kazemi, H ; Sharif University of Technology
2017
Abstract
This paper initially deals with the design of a new customized reconfigurable mobile parallel mechanism. This mechanism is called the 'Taar Reconfigurable ParaMobile' (TRPM), consisting of three mobile robots as the main actuators. Then, the kinematics and path planning for this mechanism are presented. The newly proposed mechanism is expected to circumvent some shortcomings of inspection operation in unknown environments with unexpected changes in their workspace, for example, in a water pipe with a non-uniform cross-sectional area. In this paper, 'Artificial Potential Field' (APF) has been assumed to be the path planning algorithm and its resulting attractive and repulsive forces are only...
Introduction and Analysis of Energy Index to Evaluate Arm Motion Quality in Neuromuscular Patients
, M.Sc. Thesis Sharif University of Technology ; Behzadipour, Saeed (Supervisor) ; Hoviattalab, Maryam (Supervisor)
Abstract
Quantitative motion quality evaluation has been always of much significance for CVA patients, especially the HCP ones. The purpose of the present study is to introduce and analyze the efficiency of a novel index, namely “Consumed Energy Index”, for evaluating the quality of the motions performed by HCP patients. For this purpose, Firstly, a Musculo-Skeletal model of the human arm was provided on Matlab and OpenSim softwares, with four DoFs: three DoFs at shoulder and one DoF at elbow joint as well as eight muscles. The muscles are in pairs of flexor-extensor at each DoF. The model is capable of receiving Cartesian trajectories for joints and solving inverse kinematics and dynamics to obtain...
Aeroelastic Analysis of Horizontal Axis Wind Turbine Based on Actuator Disk Method
, M.Sc. Thesis Sharif University of Technology ; Ebrahimi, Abbas (Supervisor) ; Rezaei, Mohammad Mahdi (Co-Advisor)
Abstract
The issue of solid and fluid interaction in horizontal axis wind turbines with diameter of more than 120 meters is one of the most important researching subjects of this type of turbines. This issues needs quick and exact solutions because of the high computational cost of fluid and structural domains.In this research a quick method with acceptable accuracy has been suggested which is based on computational fluid dynamic to examine the aeroelastic behavior of rotor and wind turbine tower. The actuator disc method in two domains of axisymmetric and three-dimensional has been used to compute aerodynamic forces. For this purpose a code has been written in C++ to set down virtual momentum on...
Collision-free path planning of a novel reconfigurable mobile parallel mechanism
, Article International Conference on Robotics and Mechatronics, ICROM 2015, 7 October 2015 through 9 October 2015 ; 2015 , Pages 389-394 ; 9781467372343 (ISBN) ; Kazemi, H ; Masouleh, M. T ; Novin, R. S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
This paper initially deals with the design of a new customized reconfigurable mobile parallel mechanism. This mechanism is called "Taar Reconfigurable ParaMobile (TRPM)", consisting of three mobile robots as the main actuators. Then, the kinematics and path planning for this mechanism are represented. The newly proposed mechanism is expected to circumvent some shortcomings of inspection operation in unknown environments with unexpected changes in their workspace, e.g., in a water pipe with non-uniform section area. In this paper, "Artificial Potential Field (APF)" has been assumed to be the path planning algorithm and its resulting attractive and repulsive forces are only applied to the...
Study, Analysis & Optimizing The Process Of Approval, Design & Implementation Of Projects In The Iranian Oil Terminal Company(IOTC)
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
Since the Iranian oil terminals company(I.O.T.C.) has been the main and strategic gateway of exporting petroleum in the country and plays an important role in the optimum continuity of national, regional and international energy supply chain and also conducting the needed projects whit a desirable quality and minimum time and cost has a prominent influence on steady continuity of manufacturing, importing and exporting of petroleum and gas production. The main purpose of doing this thesis is diagnosing the process of approval, design and implementation of projects in the I.O.T.C., Thus, whit regarding to the modern needs of implementing projects and the necessity of reviewing the structure...
Study & Analysis of Delays Causes of Gas Projects in Tehran Gas Company & presenting Optimized Solutions by Applying Project Management Principles
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
To deliver gas in time to different consumers like as industrial, commercial and domestic users is one of the most important parts in gas industry. So it is very important to utilize these projects in the specified time. There are huge harms for client, contractors and consumers when there is a delay in project utilization. To identify effective parameters on delays to remove them in future is an essential factor. In this research, all delay causes for TPGC (Tehran Province Gas Company) projects are analyzed and some solutions to remove these delays are presented. 10 hypotheses in relation of gas delivery have been assumed as delay causes. Then some questions have been discussed in relation...
Service Level Agreement Templates and Guides for Implementing, using eTOM
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
Nowadays, in communication industry, specially data network, in which service quality is a serious parameter, request for making connection with appropriate quality (Proportionate to demands) and necessity of clarification of obligations of service providers and customers, as well as customer awareness of submitted materials and offering various services with different qualities & costs, led service providers, specially IP based networks, to make agreements with their customers, entitled service Level Agreement (SLA). The SLA specifies the service type, mutual obligations, related parameters, measuring methods, violation threshold, penalties and loss compensation. Whereas, applying...
Condition Monitoring of Water Pipelines by Using Acoustic Method a Study of Leak Detection in ABFA
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
Water is crucial to human being. We use water for a wide variety of uses daily. However, leakage has caused substantial water loss to our precious processed water. The major contributor to non-revenue water in Iran is pipeline leakages. The water industry in the nation has invested in equipment to detect and localize leaks in water distribution systems. One of the equipment mentioned is acoustic-based. The principle of acoustic is that whenever a leak is present in a pipeline, noise is generated and will travel along the pipeline. The acoustic leak detection method is then derived by calculating the distance traveled by this noise generated by the leak. Different equipment based on acoustic...
Assessment and Performance Improvement of Hierarchical Voltage Control System
, M.Sc. Thesis Sharif University of Technology ; Parniani, Mostafa (Supervisor)
Abstract
Hierarchical voltage control is one of the conventional kinds of coordinated voltage control schemes which has been studied in some countries in the last decades. In this method network is divided into several voltage control regions and in each region voltage profile is controlled near optimal level, satisfying the economic and secure goals of the network performance. In this thesis, after the explanation of the main concepts of this scheme, its effects on the network voltage control is assessed and its performance is improved. First the primary concepts of hierarchical voltage control are explained. Then, the methods of the control regions determination and pilot nodes selection are...
Analyzing the Healthcare Wastes and Feasibility Study of Related Items (Plastics)
, M.Sc. Thesis Sharif University of Technology ; Mostafavi, Mostafa (Supervisor)
Abstract
Increasing population and competition for producing various productions and also more consumption in recent decades, result in producing more wastes. Therefore effective and continuous waste management is essential for monitoring the process (from the wastes generation source to the waste disposal) and establishing the efficient strategies to reduce wastes. One of the major sources of waste generation is hospitals that cause lots of environmental problem unless they are managed properly.Recycling is an important element of waste management that can reduce costs by innovative and proper management. The purpose of this research is identification of recyclable plastic items and estimates the...
The Analysis of Total Productive Maintenance Based on Computerized Maintenance Management System
, M.Sc. Thesis Sharif University of Technology ; mostafavi, mostafa (Supervisor)
Abstract
The main purpose of this thesis is to analyze the total productive maintenance based on computerized maintenance management system. At first, a detailed study on total productive maintenance is performed and then the requirements of this maintenance strategy are specified. Also, a computerized maintenance management system is defined which can help total productive maintenance to reach to its requirements. Finally, a conceptual model and entity-relationship model for computerized maintenance management system data base has been created
Study of HVDC Transmission for Offshore Wind Farms Based on Voltage Source Converters
, M.Sc. Thesis Sharif University of Technology ; Parniani, Mostafa (Supervisor)
Abstract
In this thesis, DC transmission of offshore wind farms is studied thoroughly. Various system configurations that are introduced in the literatures are discussed and their control scheme for normal conditions and grid faults are studied. Then, the HVDC transmission based on voltage source converter, located between a local offshore ac grid and the onshore ac system is investigated as the most practical choice. The HVDC linke circuit elements are calculated and the control strategies of the offshore and onshore converters are introduced. DFIGs are considered to be the best choice for the offshore wind turbine generators. Then, the system is simulated and the frequency of the offshore grid is...