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mafi--alireza
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Determine oil content in petroleum waxes
, Article Hydrocarbon Processing ; Volume 85, Issue 6 , 2006 , Pages 95-97 ; 00188190 (ISSN) ; Yazdani, F ; Farhadi, F ; Sharif University of Technology
2006
STATCOM System Cooling Optimization
, M.Sc. Thesis Sharif University of Technology ; Rajabi Qahnuyeh, Abbas (Supervisor)
Abstract
Today's electric power industry is unthinkable without high-power electronic converters. Statcom is one of the critical equipment; which is known for its quick response in reactive power compensation/supply. Losses in a high-power system are considerable. Most of these losses are caused by switching. In a conventional system, the cooling system is used only to control the temperature and stable operation of the switches. In this project, an attempt is made to evaluate the temperature of the outlet fluid for use in the Rankine cycle with organic materials by modeling the heat-generating parts in the Statcom equipment. Also, the unification of the Stacom cooling system with the Rankine cycle...
Regression test selection in test-driven development
, Article Automated Software Engineering ; Volume 31, Issue 1 , 2024 ; 09288910 (ISSN) ; Mirian-Hosseinabadi, S. H ; Sharif University of Technology
2024
Abstract
The large number of unit tests produced in the test-driven development (TDD) method and the iterative execution of these tests extend the regression test execution time in TDD. This study aims to reduce test execution time in TDD. We propose a TDD-based approach that creates traceable code elements and connects them to relevant test cases to support regression test selection during the TDD process. Our proposed hybrid technique combines text and syntax program differences to select related test cases using the nature of TDD. We use a change detection algorithm to detect program changes. Our experience is reported with a tool called RichTest, which implements this technique. In order to...
Test Case Selection in Test-Driven Development
, Ph.D. Dissertation Sharif University of Technology ; Mirian Hosseinabadi, Hassan (Supervisor)
Abstract
The large number of unit tests produced in the test-driven development (TDD) method and the iterative execution of these tests extend the regression test execution time in TDD. This study aims to reduce test execution time in TDD. We propose a TDD-based approach that creates traceable code elements and connects them to relevant test cases to support regression test selection during the TDD process. Our proposed hybrid technique combines text and syntax program differences to select related test cases using the nature of TDD. We use a change detection algorithm to detect program changes. Our experience is reported with a tool called RichTest, which implements this technique. To evaluate our...
Physical and hydraulic properties of a new spring packing
, Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) ; Yazdani, F ; Farhadi, F ; Deldari, H ; Sharif University of Technology
2006
Abstract
Physical and hydraulic properties of new stainless steel spring packing are introduced. The measured hydraulic properties are: dry and wetted packed bed pressure drop, loading and flooding points and the liquid holdups. The appropriate coefficients for predicting the mentioned hydraulic properties from different correlations are also reported. Hydraulic properties for this packing are compared with available packings. In spite of small size, the dry and wetted packed bed pressure drops of spring packing are less than similar Raschig and Protruded rings. The total liquid holdup of this packing is greater than other commercial packings. The big total liquid holdup and physical surface area are...
Process optimization and modeling of heavy metals extraction from a molybdenum rich spent catalyst by aspergillus niger using response surface methodology
, Article Journal of Industrial and Engineering Chemistry ; Volume 18, Issue 1 , January , 2012 , Pages 218-224 ; 1226086X (ISSN) ; Mousavi, S. M ; Borghei, S. M ; Sharif University of Technology
2012
Abstract
The present study examines the biorecovery of heavy metals from a spent refinery catalyst obtained from one of the oil refineries in Iran using Aspergillus niger. Bioleaching experiments were carried out in batch cultures using A. niger in the one-step process to mobilize Co, Mo and Ni from hazardous spent catalysts. Response surface methodology (RSM) was applied for the design and analysis of experiments with the optimization of pH, temperature, inoculum percentage, pulp density and rotation speed during the bioleaching of the metals. Experiments were designed as per the central composite design (CCD) technique. Three cubic mathematical models were derived for prediction of the responses....
Heavy metals recovery from spent catalyst using acidithiobacillus ferrooxidans and acidithiobacillus thiooxidans
, Article ICCCE 2010 - 2010 International Conference on Chemistry and Chemical Engineering, Proceedings, 1 August 2010 through 3 August 2010, Kyoto ; 2010 , Pages 331-335 ; 9781424477647 (ISBN) ; Borghei, S. M ; Mousavi, S. M ; Sharif University of Technology
2010
Abstract
In this investigation, a spent processing catalyst from one of the oil refineries in Iran was initially characterized physically and chemically. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used to mobilize aluminum, cobalt, molybdenum and nickel from hazardous spent catalysts. Bioleaching experiments were performed in batch cultures. The growth characteristics of the bacteria (pH, Eh, cell concentration and ferrous and ferric iron concentration) were determined during bioleaching along with the concentration of metal values extracted from the catalyst. The results obtained from Inductive coupled plasma-optical emission spectrometry (ICP-OES) showed that after the...
Efficiency-effectiveness assessment of national innovation systems: comparative analysis
, Article Journal of Science and Technology Policy Management ; 2021 ; 20534620 (ISSN) ; Ghazinoory, S. S ; Aslani, A ; Mafi, V ; Sharif University of Technology
Emerald Group Holdings Ltd
2021
Abstract
Purpose: The purpose of this paper is to present and evaluate the performance of innovation systems by considering two indicators of efficiency and effectiveness. The scope of the evaluation is globally and due to the situation of each country, the suggested strategies are proposed to maintain the status quo or move toward the desired situation for countries. Design/methodology/approach: The approach is to compare and benchmark the countries in terms of the efficiency and effectiveness of their innovation system. The Global Innovation Index report’s input-to-output ratio and the global competitiveness report are used for the assessment. Findings: The findings indicate that countries such as...
Efficiency-effectiveness assessment of national innovation systems: comparative analysis
, Article Journal of Science and Technology Policy Management ; Volume 13, Issue 3 , 2022 , Pages 625-651 ; 20534620 (ISSN) ; Ghazinoory, S. S ; Aslani, A ; Mafi, V ; Sharif University of Technology
Emerald Group Holdings Ltd
2022
Abstract
Purpose: The purpose of this paper is to present and evaluate the performance of innovation systems by considering two indicators of efficiency and effectiveness. The scope of the evaluation is globally and due to the situation of each country, the suggested strategies are proposed to maintain the status quo or move toward the desired situation for countries. Design/methodology/approach: The approach is to compare and benchmark the countries in terms of the efficiency and effectiveness of their innovation system. The Global Innovation Index report’s input-to-output ratio and the global competitiveness report are used for the assessment. Findings: The findings indicate that countries such as...
Design and Simulation of CMOS Based Magnetic Sensor for Biosensing Applications
, M.Sc. Thesis Sharif University of Technology ; Akbari, Mahmood (Supervisor) ; Fotowat-Ahmady, Ali (Supervisor)
Abstract
This paper presents a scalable and ultrasensitive magnetic biosensing scheme based on on-chip LC resonance frequency-shifting. The sensor transducer gain is demonstrated as being location-dependent on the sensing surface and proportional to the local polarization magnetic field strength |B|2 generated by the sensing inductor. To improve the gain uniformity, a periodic coil is proposed as a substitution for the standard process coil. As an implementation example, the circuit is designed in a 65nm CMOS process. The spatially uniform sensor gain of the array is verified by COMSOL simulations. Overall, the presented sensor demonstrates an improvement in the uniformity of the inductor’s magnetic...
Multi-variable Optimization of Vehicle Seat Suspension Considering Human Body Model Using Spring-Damper Isolators and Genetic Algorithm
, M.Sc. Thesis Sharif University of Technology ; Moradi, Hamed (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
Abstract
In recent years, the seat suspension system in commercial vehicles, industry, agriculture, transportation and … have been focused by researchers. Designing the spring-damper isolators for vehicle’s seat can be an achievable and suitable strategy to increase the comfort and decrease the risk of injuries in vehicles. In this research, the effect of vibrations due to road roughness has been examined by dynamic modeling of a vehicle in combination with the human body model. Thus by using spring-damper isolators and genetic algorithm, we try to optimize the performance of the system. Designing parameters includes the stiffness and viscosity of seat isolator and our target functions include the...
A Quasi-Three-Dimensional Multiscale Model for Two-Phase Simulation of Multi-Stream Plate-Fin Heat Exchangers
, Ph.D. Dissertation Sharif University of Technology ; Saeedi, Mohammad Hassan (Supervisor) ; Kazemzadeh Hannani, Siamak (Co-Supervisor) ; Mafi, Mostafa (Co-Supervisor)
Abstract
The present thesis aimed to develop a thermal-hydraulic model for simulation of multi-stream plate-fin heat exchangers. In this study, a multi-scale point of view was employed for three-dimensional simulation of multi-stream plate-fin heat exchangers. This is a cost-effective method that reflects the effects of complex phenomena at the micro-scale in the macro-scale model. In this model, fluid and solid matrix temperature distributions were obtained in the three-dimensional space, considering conduction heat transfer through separating plates, side plates, cap plates, and transverse conduction through fins. The modular form of the model has facilitated layer-by-layer simulation of parallel...
Rcci Curvature for Metric-Measure Space via Optimal Transport
, M.Sc. Thesis Sharif University of Technology ; Bahraini, Alireza (Supervisor) ; Ranjbar Motlagh, Alireza (Co-Advisor)
Abstract
One of the important questions in mathematics is generalized. In case of metric spaces, one of the questions is: Can we extend notions of Riemannian geometry to arbitrary metric spaces smoothly? Ricci curvature is one of the most important concepts in differential geometry. Ricci curvature is defined for the Riemannian manifold and has many applications in mathematics and physics like Einstein’s equation in relativity theory. There is a good notion for a metric space having “sectional curvature bounded below by K” or “sectional curvature bounded above by K”, due to Alexandrov. Can we define the concept of Ricci curvature in metric space? A motivation for this question comes from Gromov’s...
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
Seismic design codes reduce loads by using response modification factor. Because of the reserved strength in structural elements and capacity of structure to dissipate energy, structures can be designed for lower seismic loads. This factor has modified over time. In this thesis, the effect of the reduction in behavior factor on the response of two kinds of reinforced concrete systems were evaluated. Moment resisting frames and dual systems with different heights and regularity in plan, heve been design according to the behavior factor which is recommended in the 3rd edition of the Iranian codes of practice for seismic resistance design of buildings (Standard No. 2800). Drift and...
Prediction of Financial Markets Using Combination of Artificial Intelligence and Technical Analysis
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
Generally, nowadays, machine learning methods are used in many different areas for their superiority over other methods of prediction. Although being a tough task, stock market prediction with machine learning approaches is being spread due to satisfying results published ever yday. Machine learning methods usually use varied kinds of data ,including structured data such as market data, technical indicators and some fundamental data as well as unstructured one entailing text and graph data in order to enhance their predictability capacity. In this thesis we aimed to find out more about the importance and the contribution of structured data in prediction and we tried to attain a framework...
, M.Sc. Thesis Sharif University of Technology ; Hajji, Alireza (Supervisor)
Abstract
This thesis presents an inventory control system which is based on Meta-heuristic Algorithms.In this thesis we will optimize the input values of our tree-echelon inventory model (keeping costs,stock worth,reorder costs,...) with these Algorithms. The presented method is able to determine the optimal stock level, costs of system and number of shipments in the system. The method is basically a decision support system (DES) and it is able to provide the order scheduling parameters of goods at operational level. The aim of the current research is to demonstrate that a Meta-heuristic algorithmis capable of solving complex inventory problems and with future improvements it is able to achieve...
The Ricci Flow with Applications to the Poincare and Calabi Conjectures
, M.Sc. Thesis Sharif University of Technology ; Bahreini, Alireza (Supervisor)
Abstract
Poincare conjecture is one of the rst eorts for classifying 3-manifolds that was stated in the begining of 20th century. Eorts for proving this conjecture continued for about 100 years and nally Perelman has solved it in 2003. He has used Ricci ow which has been invented by Richard Hamilton in the early 80's. In this thesis rst we will introduce Ricci ow and will state the results before Perelman such as short time and long time existence of solution. Then we will mention some applications of Ricci ow and will state an explanation of the proof of uniformization and Calabi conjecture by Ricci ow. After that we start the main part of the thesis. In this part we will montion one of the...
Feasibility And Study(CNG Cylinder Production Plant)
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor)
Abstract
Nowadays best using of fossil fuels sources of the country (and) importance of comparison against lack of capacity in petrol production make determined the programmers and the directors to foresee and design expanded programs of the goals, to use natural gas for car fuels. To reach fulfillment of these programs, the confirmed needs of the natural gas cylinders are improved and make it essential to invest on producing compressive natural gas cylinders. In this way economical and technical change researches has been done in order to construct on department to produce 200,000 compressive natural gas cylinders in a year during two sets.(shifts) According to the results of technical researches...
Synthesis, Characterization and Field Emission Study of Molybdenum Oxide (MoOx)Nanostructures
, M.Sc. Thesis Sharif University of Technology ; Moshfegh, Alireza (Supervisor)
Abstract
Different molybdenum oxide nano/micro structure thin films were synthesized by thermal evaporation method under various growth conditions such as deposition time, temperature and evaporation source-substrate distance. Molybdenum oxide nanostructures grown on Si(100) such as nanowalls, nanostars and nanowires were characterized with scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HRTEM). Shape and type of nanostructures were determined with SEM, AFM and HRTEM analysis. XPS analysis showed that the synthesized nanostructures contained Mo6+, Mo5+, Mo4+ and...
Identification and Abnormal Condition Detection of a Cement Rotary Kiln
, M.Sc. Thesis Sharif University of Technology ; Fatehi, Alireza (Supervisor)
Abstract
One of the most important parts of a cement factory is the cement rotary kiln which plays a key role in quality and quantity of produced cement. In this part, the physical exertion and bilateral movement of air and materials, together with chemical reactions take place. Thus, this system has immensely complex and nonlinear dynamic equations. These equations have not worked out yet. Only in exceptional case; however, a large number of the involved parameters were crossed out and an approximation model was presented instead. This issue caused many problems for designing a cement rotary kiln controller. In this thesis, we employed a nonlinear system identification method for identification,...