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Preparation and Surface Modification of PC Membranes for Gas Separation
, M.Sc. Thesis Sharif University of Technology ; Soltanieh, Mohammad (Supervisor) ; Goodarznia, Iraj (Supervisor)
Abstract
The gas separation properties of polycarbonate (PC) membranes were investigated in this study. These membranes were prepared via dry and dry-wet phase inversion technique. Pure O2, N2, and CO2 gases were permeated through prepared membranes. The effects of membrane preparation conditions, including solvent type, non-solvent type, non-solvent/solvent volumetric ratio, polymer weight fraction, and drying temperature on the gas separation properties of dry PC membranes were investigated using Taguchi experimental design. Taguchi analysis show that polymer weight fraction offers the most important effect on the separation characteristics of the dry PC membranes. To get the highest...
Optimization of Centrifugal Compressor Blades with Experimental Investigation
, M.Sc. Thesis Sharif University of Technology ; Hajilouy Benisi, Ali (Supervisor)
Abstract
In this research, a novel quasi-3D design method is developed for the centrifugal compressor impeller on the blade-to-blade plane. In this method, an iterative inverse design method called Ball-Spine Algorithm (BSA) is incorporated into the quasi-3D analysis code solving the Euler equations on the blade-to-blade and meridional planes at each shape modification step. In design procedure, the difference between the target and current pressure distribution along the suction or pressure sides of the impeller causes the blade-to-blade profile to be changed and the target pressure distribution to be satisfied. In order to validate the quasi-3D analysis code, the centrifugal compressor of a gas...
Two New Meta-Model Based Artificial Neural Network Algorithms for Constrained Simulation Optimization Problems with Stochastic Constraints
, M.Sc. Thesis Sharif University of Technology ; Mahlooji, Hashem (Supervisor)
Abstract
Following the recent developments in the field of decision making, a considerable number of problems involved with stochastic systems can be thought of whose analysis depends on a set of intricate mathematical relations. In such cases, simulation is one of the most popular tools that can be applied toward analysis of behavior of such stochastic systems. Not only does not the simulation model rely on such intricate mathematical relations, it also enjoys the added advantage of being free of any restricting assumptions which may normally be considered in a stochastic system.To analyze such problem, one may aim at determining the best combination of input variables to optimize the system...
Electrodeposition of the Ni-P by Pulse Plating
, M.Sc. Thesis Sharif University of Technology ; Dolati, Abolghasem (Supervisor)
Abstract
Ni-P alloy coatings were electrodeposited using pulse current in a watt type bath in various conditions. The influences of different parameters were investigated and optimized for the highest amount of coating hardness using the Design Of Experiment (DOE) method. The optimized deposition parameters were current density 23.7 A/dm2, duty cycle 75%, frequency equal to 188 Hz, temperature equal to 70ºC and 17.5 gr/l of H3PO3. The DOE prediction of hardness for the optimized coatings was between 700 and 750 the achieved micro-hardness was about 725.8 HV. It was obtained that an increase of the current density will improve micro-hardness, decreases P content and increase deposition rate. Also, the...
The Influence of Metaphysic in Physical Science
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor)
Abstract
The influences of metaphysics in physical science in contemporary philosophy of science have the main place. In this article we consideration the scientific experiment and model for understanding of metaphysic influence .we answer the epistemological and metaphysical question about scientific experiment. We notice in the approximation in the scientific experiment and modeling. In this line we inference the exponential radiation law and consider approximation in this inference and conclude that from approximation, metaphysics of individual scientist influence in the future of physical sciences. We consider the role of model in scientific explanation and with this study we understand that...
Developin A New Metamodel-Based Simulation Optimisaztion Algorithm
, M.Sc. Thesis Sharif University of Technology ; Ghasemi Tari, Farhad (Supervisor)
Abstract
Digital computer simulation and employing the concepts of the experimental design, and other analytical tools for evaluating its output have attracted many of the scientists and researchers interests in the recent decades. The importance of this topic has been increasing and more related analytical tools have been introduced to the scientific literature. One of the powerful tools for simplifying accelerating the optimization process of simulation results, are the use of the metamodels. Use of these powerful tools becomes more eminent when the simulation runs are expensive. By the use of the metamodels the needs of conducting sampling for obtaining some more new points from direct simulating...
Flexural Behavior of Concrete Beams Reinforced with High Volume Steel Fibers
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
In recent years, the use of fibers has found considerable attention in concrete structures as in spillways, basins of dams, shell structure, industrial floors, and bridge pedestrians. Fibers modify the brittle nature of concrete and make the composite behave ductile under various types of loading. Fibers have numerous advantages such as higher impact resistance, less shrinkage, smaller crack width, higher durability and low expense for repair and maintenance.
Till now, no adequate data has been reported on concrete beams reinforced with high volume fiber. In this study, flexural behavior of concrete beams reinforced with high volume steel fibers is experimentally investigated. Concrete...
Till now, no adequate data has been reported on concrete beams reinforced with high volume fiber. In this study, flexural behavior of concrete beams reinforced with high volume steel fibers is experimentally investigated. Concrete...
Development and Application of Carbon Nanomaterials-based Polymer Modified Electrodes for Electrochemical Determination of Pharmaceutical Compounds
, Ph.D. Dissertation Sharif University of Technology ; Shahrokhian, Saeed (Supervisor)
Abstract
In this thesis, in the first part, a promising electrochemical sensor was developed based on a layer by layer process by electropolymerization of pyrrole in the presence of new coccine (NC) as dopant anion on the surface of the CNTs pre-coated glassy carbon electrode (GCE). The modified electrode was used as a new and sensitive electrochemical sensor for voltammetric determination of sumatriptan (SUM). The results showed a remarkable increase in the anodic peak current of SUM in comparison to the bare GCE. In the second part, the electropolymerization of pyrrole was performed in the presence of Nitrazine Yellow (NY) as a dopant anion on the surface of the electrode precoated with CNTs. The...
"Energy Finite Element Method for High Frequency Random Vibrations Analysis of a Reinforced Beam-Plate with a Cutout and Experimental Validation "
, M.Sc. Thesis Sharif University of Technology ; Haddadpour, Hassan (Supervisor) ; Mohammad Navazi, Hossein (Supervisor)
Abstract
In this thesis, the high frequency random vibrations analysis of a reinforced plate with a cutout is carried out using Energy Finite Element Analysis (EFEA) and the final results are validated with experimental results. EFEA method uses the average energy density as the primary variable to form the governing differential equations of energy flow in the structure. In this method the equations of space and time averaged energy density are derived in the Far Field and the energy intensity is considered as continues variable over the structure. In this work, at first for simple beam and plate an EFEA code is developed. Then the relationships for joints are derived using structural dynamics. Some...
Numerical Study on the Effect of Plasma on Flame Behavior in a Channel
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammadreza (Supervisor)
Abstract
In this study, the numerical investigation of the plasma actuator has been discussed on the combustion within a channel by FLUENT software. For this purpose, the empirical and analytical force is applied as a source term in the momentum equations in a certain area of the channel. The empirical force is obtained from experimental data and the analytical force is obtained by simplification of Maxwell equations. These equations include electrical potential and density of charge particle equations. In order to validation of UDF code, the analytical force is applied to air flow and the results are compared with other numerical simulation. Then, we discussed the results of combustion without...
Experimental Investigation of Pressure Distribution on the Surface of a Supercritical Airfoil in Transonic Regime
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
Transonic flow study is important due to its vast applications. Supercritical airfoils are designed for transonic flow to postpone drag divergence and reduce the strength of shock. This type of airfoils are chiefly used in modern commercial airplanes because of their low drag in transonic regime and, as a result, reduction in their fuel consumption. Using supercritical airfoils needs accurate investigation of flow field due to several influential factors such as specific geometry, nonlinear nature of flow phenomena, and compressibility effects. However, the availability of experimental and numerical data for supercritical airfoils is less than that of the conventional ones. Thus,...
Fruits and Vegetables Supply Chain Management (Case Study: Kerman Province)
, M.Sc. Thesis Sharif University of Technology ; Akbari Jokar, Mohammad Reza (Supervisor)
Abstract
One of the challenges of today's economy, is improving economic structures and reduce its dependence on oil revenues. Agricultural industry as an important part of the economy, is not dependent on oil revenues and improving its structure can have a significant impact on increasing revenues. Kerman province with a high proportion of horticultural products in the country, plays a significant role in Agricultural industry .However, the problem of water shortages in the country, highlighted the efficient use of water in economic purpose and crop-planning. By the problems with the current structure, lack of management of planting crops, lack of proper supply chain, redesign of agricultural supply...
Study of Surface Evaporation Currents Due to Wind-Induced in Aquatic Canopy Areaswith Floating Vegetation
, M.Sc. Thesis Sharif University of Technology ; Jamali, Mirmosaddegh (Supervisor)
Abstract
The aquatic canopy areas such as wetlands play an important role in ecology of these area. The exchange flow between open water and vegetated area occurs due to sunlight and surface cooling. Wind also causes surface evaporation and create a cold layer at the surface of water. The creation of exchange flow and its magnitude depends on parameters like solid volume fraction and thermal gradient. In this thesis, the goal is to determine the effects of floating vegetation on the hydrodynamic characteristics of exchange flowas a result of surface cooling experimentally. In this research, the PIV method was used to measure velocity profiles. In the experiments, solid volume fraction, depth of...
Dynamics Modeling and Linear Controller Design of Marin Vehicles
, M.Sc. Thesis Sharif University of Technology ; Seif, Mohammad Saeed (Supervisor) ; Banazadeh, Afshin (Co-Advisor)
Abstract
In recent years, autonomous underwater vehicles have had an increasing role in underwater investigations. These vehicles are used in various fields, including military applications, commercial uses or scientific investigates and also mapping purposes. The test and the fabrication of these kind of vehicles are very costly and time-consuming because of not only the risk of losing the vehicle due to the various computerized errors, but also as a result of the costs of supporting staff, equipment and the structure of a process. As a result of the environment where these vehicles do their missions, there is a crucial need of control methods which have enough accuracy as well as robustness against...
Developing a Model for Design of Small Hydro Power Systems and It’s Validation with Empirical Results
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Hydro power is a clean energy resource which has numerous advantages over other renewable energy systems including competitiveness with fossil fuel systems, high reliability, considerable potential, and availability of technology. These advantages have drawn attention to hydropower systems. Small Hydro Power (SHP) systems can be used for supplying the demand of rural and remote areas where electricity network rarely exists. SHP may also provide an investment opportunity. Comprehensive analysis of design features and operation of SHP and management of risks involved requires development and application of reliable analytical tools. The present research aims at developing a model for optimal...
Numerical and Experimental Evaluation of Steel Moment Resisting Frames with Shear Fuse
, M.Sc. Thesis Sharif University of Technology ; Mohtasham Dolatshahi, Kiarash (Supervisor) ; Mahsuli, Mojtaba (Supervisor)
Abstract
This paper puts forward an innovative energy dissipation system in steel moment resisting frames, and presents its experimental and numerical studies. In the proposed system, a replaceable beam with a smaller cross-section than that of the main beam is placed at the mid span of the beam designed to act as a shear fuse. This shifts the location of the plastic hinging from the ends of the beam to the middle since the shear fuse yields in shear prior to the flexural yielding of the main beam. This system eliminates the need to comply with the rigorous limitation on the beam span-to-depth ratio that is proposed by seismic design codes to ensure the formation of plastic hinges at the two ends of...
Experimental Study of a Side Intake in Transonic Speed
, M.Sc. Thesis Sharif University of Technology ; Farahani, Mohammad (Supervisor)
Abstract
This study aims to evaluate aerodynamic coefficients of an airplane with air breathing engine experimentally. In these experiments, an ejector is used to better simulate flying conditions and aerodynamic interferences generated in inlet and exhaust engine. Therefore, at first, an ejector was designed for simultaneous simulation of exit cold flow and inlet flow of engine. All tests were conducted at QRC Trisonic wind tunnel and at Mach number of 0.5 to 0.85, angles of -4 to 6 deg. and for various amounts of pressure ejector and control surfaces angles. Finally, for the Mach number of 0.5, effect of roughness on the aerodynamic coefficients was examined. The results showed that, drag...
Characterization and Investigating the Effectiveness of Reservoir uncertainty on Waterflooding in a Shared Oil Field
, M.Sc. Thesis Sharif University of Technology ; Masihi, Mohsen (Supervisor) ; Ayatollahi, Shahaboddin (Supervisor)
Abstract
In field management workflow, after preparation of dynamic reservoir model, next step is determining the uncertain parameters and history matching. In this step, simulation model is conditioned to available field data. In this inverse problem, different geological and petrophysical properties may provide equally good history matches. Such diverse models are likely to show different production behaviors in future. This ties the history matching with the second step, uncertainty quantification of predictions. Multiple history matched models are essential for a realistic uncertainty estimate of the future field behavior.This thesis introduces the application of two novel population-based...
Investigating Wind-Induced Currents in Sloped Aquatic Canopy Areas
, M.Sc. Thesis Sharif University of Technology ; Jamali, Mirmosadegh (Supervisor)
Abstract
Aquatic canopy zones play an important role in maintenance of ecosystems. These areas are ubiquitous near rivers, lakes, lagoons, estuaries and shore lines. Governing dynamical systems through these areas have direct influence on, how nutrients and other vital materials for living things disperse. Also, they can control the amount of dissolved oxygen within the body of water in these regions. Nowadays, investigating the effects of vegetation grabbed the attention of many scientists and is a very important burgeoning field. In this study, the effects of surface cooling which resulting from mild wind blow have been investigated. In fact, two type of different currents form when wind blows...
Experimental Investigation of the Effect of the Bleed Slant Angle on the Performance and Stability of a Supersonic Air Intake
, M.Sc. Thesis Sharif University of Technology ; Soltani, Mohammad Reza (Supervisor)
Abstract
In the study of supersonic air intakes, two important issues including performance and stability are considered. In these types of intakes, when inlet mass flow rate is reduced to a specified amount, a self-sustained instability called Buzz phenomenon occurs. During this phenomenon, shocks and expansion waves oscillate ahead of the intake that will degrade the performance considerably due to the periodic pressure fluctuations inside the intake. In the current study, a supersonic axisymmetric air intake with mixed compression which has designed for a free stream Mach number of 2.0 has been tested were conducted for free stream Mach numbers of 1.8, 2.0, and 2.2, and the results were analyzed...