Sharif Digital Repository

Fire is one of the most important events in nuclear power plants which has a large share of total core damage frequency. For example, the core damage frequency in Bushehr nuclear power plant from fire accidents is 6.1E-6/ year which is equivalent to about 63 percent of core damage frequency from all internal accidents. However, due to the unavoidable presence of flammable materials, e.g. Electrical equipment, cables, gas, flammable liquids, …), it is impossible to prevent fires in these plants . Fire at nuclear power plants may be caused directly or indirectly by one or more initiating events, which the following accidents in turn would threaten the safety of the plant. In this project,... 

Station Blackout (SBO) involves Loss of Offsite Power (LOOP) concurrent with failure of the onsiteemergency ac power system. Although SBO is a beyond designbasis accident, in recent years this accident attracts a lot of attention. Fukushima nuclear accident which was initiated by earthquake followedby tsunami led to a SBO accident. In this thesis, Probabilistic Safety Assessment (PSA) is applied to analyze SBO in IR-360 nuclear power plant and to compute its frequency. Meanwhile, weak points of the plant are identified in order to minimize the SBOprobability of occurrence. Fault tree method is used to evaluate emergency power system and offsite power system reliabilities. Common Cause... 

Nowadays, most of businesses are becoming computer-based. This trend causes the organizations to become more vulnerable to internal and external threats. Internal threats are done through insiders. Insiders unlike outsiders have capabilities which aid them to easily carry out their illicit activities. Unfortunately, most of research in computer security has focused on the outsider threats, whereas the most damaging is the result of insiders’ illicit activities.This dissertation addresses three primary necessities of the research in the area of insider threat: a consistent definition of insider threat, a classification of types of insider threats, and a classification of vulnerabilities which... 

Due to the dynamic topology of vehicular ad hoc networks, routing of packets in these networks faces a lot of difficulties. The situation will become more challenging when we have to deal with Delay Tolerant Networks (DTN) which are also sparse and partitioned and we need to use some vehicles to store the packets and carry them from one partition to another. Despite all these difficulties, by looking through movements of vehicles in an urban environment, we can find out that the topology of the network does not change in a pure random way and we can bring the traffic models of streets into account for having better routing performance. In this thesis, we proposed an intelligent routing... 

In this project, Fe3O4 nanoparticles were synthesized and coated with different polymeric materials for drug delivery application. For this purpose, water dispersible oleic acid(OA)- pluronic block copolymer coated magnetite iron oxide nanoparticles were synthesized that can be loaded with proper doses of cephalexin. Our data indicated that formulation of iron oxide nanoparticles was developed by optimizing the amount of oleic acid required to coat iron oxide nanoparticles and then by optimizing the amount of pluronic required to form an aqueous dispersion of oleic acid coated nanoparticles. Synthesis of magnetite nanoparticles was done by the addition of a strong base (NH4OH) to ferrous... 

In this thesis, a numerical analysis of micro chamber filling in centrifugal microfluidics is investigated. In the development of micro total analysis systems, it is often necessary to achieve complete and uniform filling of relatively large micro chambers. With centrifugal devices, these large micro chambers must often be orientated perpendicularly to the direction of centrifugal force and are usually bounded by materials with varying surface properties. On the other hand, the mixing characterization of two fluid by centrifugal microfluidic method has been also conducted. The multiphase flow analyses based on Eulerian-Eulerian approach have been conducted and the VOF method was used for ... 

Gas turbine engine control is a demanding task that requires the regulation of the thrust as well as the satisfaction of the limitations such as engine aerodynamic instability, over temperature and over speed. Fuzzy logic is an attractive technique for the control of poor understood unmodeled, or complex systems especially where the experience of human operators is available to provide qualitative rules. In such cases, it has been found that control decisions can be made on the basis of linguistic measures or fuzzy algorithms. The controller that is designed on the basis of this theory is called fuzzy logic controller. The main objective of this thesis is hardware implementation of fuzzy... 

Here, we first ivestigate some available nonsmooth algorithms indentilying their drawbacks, and then provide some guidelines to avert these drawbacks. We divide the algorithms to two main classes, first order and second order. The main drawback of the second order class of algorithm is that there does not exist any suitable method to approximate the generalized second order derivative. To solve this problem, we construct a uniform approximation for the generalized Hessian matrix of an SC1 function. Using the discrete gradient and the extended second order derivative, we define the discrete Hessian matrix. We construct a sequence of sets, where each set is composed of discrete Hessian...