Sharif Digital Repository

A prismatic high temperature gas-cooled reactor (HTGR), which is a graphite moderated, helium-cooled reactor, is a promising candidate for next generation nuclear power plant in that it enables applications, such as hydrogen production or process heat for petrochemical by supplying heat with core outlet temperatures as high as 1000°C. A Thermal Hydraulic Analysis Code (THAC) for gas-cooled reactors has been developed. THAC implicitly solves heat transfer equation of fuel, graphite block and helium. Three types of fuel pins were considered; solid fuel pin, fuel pins with inside holes and annular fuels with coolant flow from its inside and outside surfaces. THAC predicts axial and radial... 

In this thesis, a model of electrochemical treatment of tumor is simulated by numerical method. The orthogonal collocation method is used for numerical solution. The model is solved in two situations, one in the absence of chemical reaction (water hydrolysis) and the other when chemical reaction is occurring in the electrolyte. In transient mode, it is possible to solve the model in low level currents (about 20 A/m2) by few number of collocation points (about 15 points) and only in a single domain. However, by increasing current, it is necessary to use more points in domain especially in the first 10% of the domain (very close to the electrode) where the maximum rate of diffusion/migration... 

In this work, a non-isothermal model of natural gas in pipelines including mass, momentum and energy balance equations are used as model equations for modeling and state estimation in gas pipeline systems. An algorithm is proposed to handle the discontinuities that appear in the dynamic model of a GTN. The states of GTN are estimated using the continuous/discrete form of the extended Kalman filter for two benchmarks and some heuristic rules for sensor placement in a GTN are concluded. Also, a framework for distributed and decentralized state estimation in high-pressure and long-distance gas transmission networks (GTNs) is proposed. Some heuristic rules are suggested for system decomposition... 

this is one of the most widely used is the weighted residual method. The advantages of this method is likely to reach an appropriate solution is (in this project collocation method for solving systems of differential equations is used). After solving steady-state model with the lowest number of variables come to turn the control measures, including non-linear design of a Kalman Filter incentives that could be the orthogonal modulation system (which requires less computational time and good accuracy) as a representative of the system in the state estimation, optimization and control system used. In the end, offering a range of control methods such as multivariate linear and nonlinear... 

The aim of this work was to investigate the performance of different kinds of Linde type A zeolite (LTA) for the dehydration of Tetrahydrofuran (THF)-water solution. Batch experiments were carried out to evaluate the effect of various operating parameters such as contact time, initial concentration, mixing temperature (10, 15,and 25 C), amount of adsorbent, and zeolite type(3A, 4A, and 5A zeolites). In theoretical studies, we took the advantage of several types of equilibrium model isotherms such as Langmuir, Freundlich, Dubin-Kaganer-Radushkevich (DKR) to describe the experimental adsorption data. Besides, three adsorption kinetic models including pseudo-first-order, pseudo-second-order,... 

Simulation and controlling nonlinear process is one of the challenging problems in academic and industrial research. Saving data for keeping history of process or arising number of calculation for optimization in control design, is forcing to decrease number of equation or order of system. One of the methods to decrease the order of distillation process is using the travelling wave theory. This solution shows god accuracy for simulation the behavior of distillation column. On the other hand finite difference method as a solver for distillation equation takes some time to converge to steady state condition and the numbers of calculation in this method are high. Finite difference method is...