Sharif Digital Repository

Compact linear accelerator is equipped with a single fixed motorized wedge that produces different wedge angles by combining an open and a wedged field in the appropriate proportions.
In this work, the required data for the Treatment Planning System, TPS were generated for utilizing Compact motorized wedge, MW and was verified by dosimetry. To verify MW, the accumulated wedge profiles at a depth of 10 cm for different wedge angles were measured using 2-D Profiler and were calculated the wedge angles using an analytical formula. The validity of effective wedge angles 2-D Profiler has been done by determining the wedge angles in accordance with ICRU-24 for compact MW and Telecobalt... 

Ethanol is one of the most important solvents in the industry with different applications in various fields, which can be used in disinfection solutions, perfumery, paints, fuels, etc. In this research, a predefined superstructure is examined to investigate the possibility of ethanol production by a process which has the lowest production cost per kilogram of ethanol.Various feeds can be used to produce ethanol, the most important of which are bagasse, wheat starch, sugar beet, sugar cane, corn and dextrose. In this study, the corn is selected as feed, while each of the above feed, and contains a different percentage of glucan, xylan and lignin. Conversion factor of components in... 

Monitoring of the water transmission networks is an essential factor to regard efficient, safe and economical strategic considerations. Several parameters (fluid pressure, fluid flow and fluid temperature in some cases) are measured to monitor the water transmission networks. The number and location of these measurements in deferent positions affect the cost and quality of the network states monitoring. It is obvious that measuring the all parameters and states of the network is not cost-effective even when it is possible. The conventional sensor-location methods have been developed based on the pressure variation stemmed from a leakage in the network. This study proposes a new procedure to... 

The design and optimization of processes was focused in the past on economic issues such as profitability and return on investment, and less attention has been paid to environmental issues. In recent years, by introducing environmental criterion as pillars of sustainable development, environmental optimization of processes has becoming an inseparable element of the process engineering. Therefore, it is necessary to examine the compatibility of environmental indicators with economic objective. The purpose of this study is to investigate environmental indicators and economic objective function in optimizing the Crude Distillation Unit (CDU) of an oil refinery. The CDU is one of the most... 

The abstract is the most important section of the thesis because many readers limit most of their reading to abstracts, saving in-depth reading for specific theses. It should give the reader a "preview" of what's to come. The abstract should emphasize new and important aspects of the study or observations. The purpose of the abstract is to allow researchers to decide whether or not to read the whole thesis. The abstract is what researchers read first to decide if the thesis is important, interesting, and it allows them to assess the relevance of a thesis to their own research, without having to read the entire thesis. Thus, it is crucial that the abstract both summarize succinctly the key... 

Supply Chain is a complex system and its modeling generally results in complicated mathematical problems. Solving these problems, one should make assumptions that make solutions impractical. Knowledge-based frameworks such as ontology has been proposed for tackling this issue. In this thesis, with relying on a seven step ontology developing method, UML as development language and Rational Rose as development software environment, an application ontology for supply chain and its problems has been developed. Furthermore, with use of a Benzene, Toluene and Xylene supply chain as an instance, it has been shown qualitatively how to use the ontology in various supply chain problems. It is... 

In this thesis, in the first step, design of an Agent Based framework was accomplished. Agent oriented programming is a kind of programming based on distributed processing by agents in a same location or not. UML was used to design the the agent based framework. To implement the designed framework, C++ programming language was used. Embarcadero C++ Builder IDE was chosen to implement the design. Then the designed framework was used to develop a sofware for data reconciliation. The branch for dynamic data reconciliation of this project was extended. To validate the ability of the sofware, a distillation column model with 7 states was selected. The result of gross error detection and data... 

Asphaltene, the heaviest and most polarizable fraction of crude oil, has a potential to precipitate, deposit and plug pipelines, causing considerable production costs. The main objective of this study is to contribute to the thermodynamic and transport modeling of asphaltene in order to predict its precipitation, segregation and deposition. Potential calculation of some thermophysical properties of asphaltene is also explored. Predicting the flow assurance issues caused by asphaltene requires the ability to model the phase behavior of asphaltene as a function of pressure, temperature and composition. It has been previously demonstrated that the Perturbed Chain form of Statistical Association... 

Diabetes has become the most prevalent disease all among the world. One of the complications of this disease is diabetic nephropathy. Diabetic nephropathy occurs when the kidney cells encounter high glucose concentration for long periods. Kidney cells use glucose as their energy supply. However, the excess glucose in the diabetics triggers specific gene pathways, gradually leading to diabetic nephropathy. As a result, proteins’ levels and the activity of transcription factors change during the disease progression. Diabetic nephropathy is characterized by excessive deposition of the proteins comprising the extracellular matrix in the mesangium, basement membrane of the glomerulus, and in the... 

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... 

Nowadays, one of the most challenging issues concerning the manufacturing industries is the shortage of available resources and their increased costs. As a matter of the fact, for these industries, optimizing the processes is not something to be ignored and one of the most important goals is reducing the costs of manufacturing and increasing the profits of sales. On the other hand, in actual situations, due to the complexities of optimization problem and numerous calculations, the classical methods would be limited to very simplistic cases in which most of the practical changes are ignored. In such problems, the need to use strong optimization techniques like the genetic algorithm is evident... 

Nowadays diabetes is considered as one of the common diseases among mankind. Different body organs utilize the glucose or the sugar existed in various kinds of food as an energy source in order to provide required energy for their activities. Insulin hormone which is created by the pancreas gland has a very significant role in easing the respective procedure. Therefore, when the body is not capable of producing enough insulin, then glucose aggregation in the blood leads to higher blood sugar and thus a disease called diabetes type1. Up to now, considerable research activities have been done regarding the diabetes type1modelling. One of the bolded drawbacks of such models is that the effect... 

In this project a framework for Model Based Fault Diagnosis (MBFD) in a Gas Transmission Network (GTN) was developed. A black-box linear state-space model was used to capture dynamic behavior of an industrial benchmark for GTN. A full fledge commercial network simulator were used to obtain the required data for process identification. In order to check the robustness of the model zero mean white noise was imposed on various output obtained by the commercial simulator. Kalman filter was used to estimate the states of the GTN. These estimated states along with the measured output (all obtained from the commercial simulator) are almost similar to their corresponding estimated signal. This shows... 

Mathematical models are used for describing physical systems to make it possible to study and investigate the behavior of these systems and compare their performance and improve them. For this reason, a mathematical model for cardiovascular system and respiratory system is used to study how these two systems interact. The cardiovascular system model and the respiratory system model comprise four and two compartments, respectively. In fact, the combined model contains the left and right ventricles, body tissue, lung, systemic blood circulation, and pulmonary compartments. Heart rate and alveolar ventilation are assumed to be the quantities through them the central nervous system controls the... 

Due to continuous improvements in manufacturing and the fact that modern technologies such as microprocessors, are becoming more efficient along the rapid growth of nonlinear control methods usage, the application of these two tools together has entered various fields of biomedical engineering, particularly neural prostheses. In this study, the methods of analysis and control of nonlinear systems were used to investigate and improve the behavior of the neural breathing system on the basis of Hodkgin-Huxley model as the original model of the neuron. Using the principles of differential geometry and robust control methods – based on combination of exact input-output linearization ideas,... 

In this thesis, the latest human respiratory system is extended such that it addresses the effect of blood acidity on the performance of the human respiratory system. Since the model does not take into account any controller, two PI controllers proposed by Bental have been used to simulate the closed loop behavior of the respiratory system. Since, in the original model blood pH is considered as a constant value, the extended model has been used for the case where the blood pH pumped by heart is assumed to be and the obtained results have been compared with those of the original model. The similarity of the results shows the extended model to be valid for the normal case. Model since t he... 

The main objective of the present work is to achieve green design of a methanol plant by using life cycle process design (LCPD) and multi-objective optimization. As a starting point, simulation of Lurgi’s combined reforming process as a conventional reference methanol case (RMC) was performed in order to obtain its operational and kinetic parameters as well as its environmental impacts. The environmental concerns were calculated using one of the modern environmental impact assessment methods, i.e. life cycle assessment (LCA). To perform life cycle assessment of RMC, methanol production plant as well as its auxiliary units should be considered. The auxiliary units in the RMC include cryogenic... 

Application of the advanced control techniques and information technology in the biomedical engineering have been the focal point of the research communities in biomedical engineering due to the rapid growth of the nonlinear control theories along with the computer hardware. In this work the application of differential geometry and globally linearizing control has been applied to efficiently control the first phase of HIV disease based on the HIV infection model proposed in the literature. All the efforts have been in the way to obtain a suitable scenario of drug administration to suppress and control the infection. In the proposed scenario, drug administration is time dependant and... 

In the present work, a comprehensive economic, environmental and exergy analysis and multi-objective optimization for world’s largest aromatic plant are provided and the interaction between decision variables in these criterions is discussed. In the first part, potentials of seven environmental features of the operational plant are quantified and normalized using life cycle assessment (LCA) for both process waste and utility environmental impacts. Exergy analysis (EA) is also used to determine the lowest eco-efficiency equipment. By choosing proper decision variables based on sensitivity analysis, LCA and EA results, optimization is performed to determine the best design variables based on... 

All living entities requires energy to continue their lives. In human beings this energy is provide through consumption of food, at first the consumed food gets converted to glucose and the produced glucose enters the blood and then goes to the body cells in which it is used to produce the required energy. The essential hormone which makes it possible to use Glucose for energy production is INSULIN. In the patients suffering from Type 1 Diabetes, lack of Insulin production makes it impossible for the cells to use Glucose for the production of their required energy. In these patients due to the fact that the blood Glucose is not used by the cells, the Blood Glucose Level (BGL) increases,...