Sharif Digital Repository

In the recent years, field effect transistor has been made by using graphane. But there has not been any study about bipolar transistor. Bipolar transistor can’t be constructed using graphene due to the fact that its band gap is zero. So in this thesis, in an attempt to remove this difficulty, the bipolar transistor made using graphane has been investigated and their property has been compared to those of three dimensional silicon transistors.
At the beginning of the thesis, we will have a review of graphane diode and will consider the procedure for evaluating its current which would be the report of what has been done sofar. After that we made graphane transistor using graphane diode... 

Computational Nano Mechanics growth has led researchers towards the development of new multi-scale models. Accordingly, in this dissertation, a step was taken towards introduction, presentation and creation of a new concurrent multi-scale by studying the feasibility of coupling of molecular dynamics methods and temperature related Cauchy-born.To do so, firstly, the above mentioned methods have been studied and then in order to perform molecular dynamics simulations, a program written in C++ language has been used. The accuracy of the written code has been confirmed through studying intuitive phenomenon of gas perfect particle exit from cylinder with an open end. The interpretation of out put... 

Solar energy is one of the man's solutions to cope with problems involved in exhaustible fossil resources. In this regard, using photocatalysts is a practical and rational pproach.Nanotechnology facilitates using catalysts and photocatalysts with more productivity.TiO2 semiconductor is one of the most popular material in this field but its efficiency is low by several factors such as being inactive in visible light, recombination and the high cost of using noble metals. In this research, we tried to fix these limitations by creating a p-n junction TiO2 - NiO nanocomposite. The samples are made by three methods: impregnation, ultrasonic assisted modified impregnation with ammonium hydroxide... 

In past two decades, the direction of oil and gas exploration has moved towards deep water drilling. The pressure and temperature in these zones are ideal for gas hydrate formation that can cause serious and sometimes uncontrollable issues during drilling operations. Gas hydrate formation while drilling can cause problems such as occurrence of kick and blowout, plug chock and kill line, and change in rheology of drilling mud. On the other hand, nowadays, nanotechnology has created an evolution in engineering sciences and because of the wide range of this science, drilling industry is affected like other industries. In the meantime, because of high yield, high stability and various methods of... 

Nanotechnology requires a number of infrastructures for reaching its sustainable development. For each step of its development , various infrastructures should be studied and prepared in advance.In this direction, by introducing and recognizing the priority of Iran Nanotechnology R&D indexes ,the present research is going to propose an effective help. In this case, after studying the related literature and gathering the needed data , 27 indexes were recognized. Then , the indexes were divided in 7 criteria.In order to find the priority of the applied indexes , Fuzzy Multiple Criteria Decision Making (FMCDM) was applied. As the weighting of 7 criteria had been found by FANP , the... 

Polysulfone (PSU) and polyethersulfone (PES) porous membranes; and mixed polymers (PSU and PES) with nanoparticles TiO2, were prepared for air humidification. The mechanical properties and morphology of these membranes were studied by Tensile Tester and SEM/EDX. The effects of membrane composition and operating factors on humidifier performance were investigated. The results revealed that the membrane composition and its structure have significant effect on humidification. The porous membranes with finger type cavities had higher humidification performance but lower mechanical properties. The Membranes which were prepared from polysulfone polymer, 10 wt % of polymers in casting solution and... 

Due to daily decrease of fossil energy resources, increase of environmental pollution which is included of toxic and greenhouse gases, and extensive growing rate of demands in transportation industry, especially vehicle industry, developing solutions in using fuel cells are vital for this industry in our country. Fuel cells are green, efficient and also powerful energy generators. According to potential advantages of fuel cells, structure, performance, benefits and also types of fuel cells are introduced as a desired energy resource. Indentifying existing choices of energy generators and ranking them using MCDM (Multi-Criteria Decision Making) technique was the first step to perform a... 

Innovative small tech companies are required to often have cooperation with large companies in order to scale-up and commercialize their products. Such cooperation is referred as “Technological Cooperation” since it relies on development and commercialization of technology. In this research, as a multiple-case study in the arena of nanotechnology, five cases of technological cooperation are analyzed and key successful factors are identified. In this endeavor, 15 comprehensive interviews were conducted with both small tech companies and technology applicant companies, including experts of Nanotechnology Innovative Council (INIC) – playing the role of a mediator. Due to lack of a comprehensive...