Sharif Digital Repository

Nowadays application of metallic catalysts in many of the organic reactions has been developed; therefore, different types of catalysts have been produced and used. In this way, in the first part of this thesis magnetic cobalt ferrite and nickel ferrite nanocatalysts were synthesized using co-precipitation method and their activity as catalyst was investigated in C-O bond formation reaction. This reaction was carried out between different types of aryl alcohols and aryl halides with good to excellent yields. The results showed that using N,N-dimethyl formamide as solvent, potassium carbonate as base and 5mol% of nanocatalysts at 80°C are the optimized condition for this reaction. In the... 

The problem of consciousness and its place in nature is the central issue in current theorizing about the mind and it also has close relationship with mind –body problem . As if we can prove consciousness and its unique properties then we can use it to reject physicalism but we were faced with other problems such as causal relations. There are different explanations about the nature of consciousness with the world but most of them place in dualism/ physicalim twofold. Russelian monism have recently argued, this view retains the strengths of traditional versions of dualism and materialism while avoiding their weakness. And In this thesis we have studied the theory and then discuss the... 

Using Functionally Graded Materials (FGMs) in hot sections of aged aircrafts is one of the most important ways for life extending of Thermal Barrier Coatings (TBCs). Sudden variation of thermal stresses in interface of bond coat and ceramic coat layers could be changed to gradual variation with use of FGMs. The stress in FGMs has been the subject of several researches. Both macro and micromechanical modeling approaches have been used in these studies. In the macro mechanical approach, FGM is modeled as a multi-layer composite in which mechanical properties of each layer is found by averaging the properties and volume fraction of FGM constituents through the thickness of the layer. In this... 

Vehicular tunnels are very prone to excess of air pollution due to their enclosed nature. Inadequate ventilation combined with high traffic flow result in elevated concentration of vehicle-induced air pollutants, which can pose serious health hazards. This study was carried out in the longest vehicular tunnel in Tehran, locally referred to as Tohid tunnel. Traffic flow characteristics, carbon monoxide level and it's dispersion along the tunnel were investigated in this project. Data were collected in 4 days and 3 times a day, 7-8 in the morning, 11-12 and 17-18 in the evening. Measurements were conducted at fixed locations, outside the tunnel,... 

Designing efficient and secure electronic voting protocols without the presence of trusted authorities, which are known as decentralized voting protocols, is one of the most interesting and challenging problems in cryptography. In these protocols the outcome of the protocol is determined by voters collaborating with each other. Since voting is a significant concept in every society, the correctness and security of voting protocols are important. For security analysis of electronic voting protocols, an intuitive proof is not enough and we require a comprehensive approach that provides provable security. In this thesis, we use universal composition framework to analyze a decentralized e-voting... 

Knowledge based companies have a very important role in progress toward an economy based on knowledge and technology. One of the most important issues about these companies is pattern of Learning Technological capabilities. This issue and the question about the focus of companies about acquire and development of technological capabilities are subjects that have instructive points for both minor and major scales, for companies themselves, and public directing and investing. In this paper pattern of learning of technological capabilities are reviewed for four Knowledge based companies in electronics equipment industry, also the time needed for acquiring levels of technological capabilities for... 

Content-Externalism is the view according to which, content of mental states are determined by relation that the person has with his environment and content of mental states does not depend on intrinsic properties of subjects. According to this view, if two persons with exactly same intrinsic properties were in different environments, contents of their mental states would be different. On the other hand, the doctrine of privileged access to mental states asserts that if cognitive faculty is functioning properly, then subject can know the content of his mental states a priori. Many critics of externalism believes that accepting externalism along with privileged access terminate to... 

In his book “Groundwork for the Metaphysic of Morals ”, Kant tries to pesent a formula for the supreme pinciple of morality. He ends up introducing three formulae that he thinks are all the same and just pesenting one formula In three different ways. After publishing this book, many criticisms were levelled against both his way of argument and the efficacy of his proposed formulae. In this enquiry, by focusing on the first two chapters of Kant’s book, and by considering the universal law formula and the humanity formula, we try to answer these criticisms. In the way, we make use of the new reading of Kant’s view- the critical reading- proposed by Samuel Kerstein, according to which Kant’s... 

Our country in no measure is considered as an industrial one, despite its chain of small, medium and large industries. The vague, general “developing” term might be the best term to assign to economic-industrial condition of our country. We have a fairly limited number of big industrial firms (BIF) which could continue operation without state’s supports in a world BIFs are considered as the key indices in industrial development. The question comes to mind with reading what came above is this study’s main question, “What went wrong?”. This study follows the historical approach to the question through a comprehensive case study. Historical case-study thus is our main research approach here.... 

Think of an Alpine hiker who because of avalanche and a blinding blizzard, is stranded on a desolate, mountain path facing a chasm. The hiker cannot return the way he came because of the avalanche, yet, if he stays where he is, he will freeze as the temperature plummets. The hiker’s only real hope is to jump the chasm. Knowing that exertion generally follows belief, the hiker realizes that his attempt will be half-hearted, diminishing his chance of survival, unless he brings himself to the belief that he can make the jump. In circumstances like these, one is clearly justified both in forming beliefs motivated by pragmatic reasons, and in suppressing beliefs (I cannot make the jump) motivated... 

Consciousness is the most difficult problems in the philosophy of mind and science. Some philosophers propose a evolutionary explanation of consciousness but Another dispute over that. If we give evolutionary explanation of consciousness, we must investigate what theories of consciousness and views of mind-body can support evolutionary consciousness. Then we must pass three steps. The first step, reply to objection of evolutionary consciousness. The second step, weaken view of opponents. The third step, explaining evolutionary consciousness. In this dissertation I try clarify those steps and show objections of them. If those objections was true, I accept them else reply to them. Eventually I...