Sharif Digital Repository

Two-dimensional (2D) nanomaterials are ultrathin nanomaterials with a high degree of anisotropy and chemical functionality. Research on 2D nanomaterials is still in its infancy, with the majority of research focusing on elucidating unique material characteristics and few reports focusing on biomedical applications of 2D nanomaterials. Here we report the properties and application of 2Dnanomaterials in field of bio technology while used main material in our project is graphene oxide for investigating its antibacterial properties. Because the properties of graphene oxide (GO)-based materials strongly depend on the lateral size and size distribution of GO nanosheets; therefore, GO and its... 

Knowing the trip information such as paths that travelers prefer to choose is useful for practice in developing certain transportation planning step. There are different methods such as using GPS and conducting survey for volunteer travelers in order to understand actual paths. Obviously, all of these methods have some deficiencies. This research suggests and examines a method for estimating travelers’ path by using cell phone data. The main advantage of using these kinds of data is enabling the process of collecting information without any active interference of the users. A big data set consisting of 300,000 cell phone users’ information in the city of Shiraz is studied to achieve this... 

Today's interest growth to the underwater explorations and navigations demands to design appropriate underwater communication methods and systems is strongly felt. Although radio frequencies which are widely used in free space communications, they cannot be a decent candidate for underwater wireless communications, due to their sever attenuation in water environment. On the other hand, underwater acoustic communications has been widely studied and implemented in past decades, because of little attenuation in comparison with other means of communications in water environment. However, acoustic communications suffer from limited bandwidth, low propagation speed, and low security in compared... 

Energy production from fossil fuels such as oil and gas is one of the non-renewable energies, which causes many environmental problems such as global warming and environmental pollution. The existence of these problems has led to agreements such as the Glasgow Environmental Agreement, which obligates governments to apply methods to reduce the production of greenhouse gases, which include reducing the consumption of fossil fuels and increasing the use of renewable energy. Sea wave energy is one of the renewable energies that can be used to generate electricity. In the seas of Iran, including the Caspian Sea, Persian Gulf and Oman, there are sources of wave energy that can be used and are... 

It is the goal of this thesis to develop an analytical model for the hydro-mechanical deep drawing (HDD) process of an axisymmetric sheet metal with the fixed gap method to evaluate the effects of some assumptions such as: proportional loading, plane stress, and constant thickness conditions. The effect of parameters on the HDD process is also studied. The main model is developed with considering the normal stress and part thickness change, non-proportional loading, bending and unbending effects at the top of the cup wall. The interrelationships between geometrical and mechanical variables are obtained in the finite difference form based on the incremental strain theory, thereby being solved... 

The use of fluorophores in metallic and non-metallic analysis, have received great attention for chemical sensing due to the high sensitivity and selectivity. Fluorophores through participating in emission mechanisms, interact with analyte and the emission intensity changes, which leads to determination of analyte concentration. These mechanisms are included fluorescence resonance energy transfer and fluorescence emission quenching. In the first part of this thesis, a highly sensitive probe for detection of copper ions was developed based on fluorescence resonance energy transfer due to the plasmonic peak of citrate capped gold nanoparticles and emission peak of FITC. Quenched emission of... 

From the past, oil and gas industry has been among important industries in Iran and a major source of the government income. Hence achieving successful projects in the industry is of great importance for the country’s development and timely completion has always been considered as one of the characteristics of a successful project. Developing oil and gas fields, as it affect all of the other projects in this industry, is construed as crucial.In this regard, from the first oil exploration in Iran, authorities have signed different types of contracts with many contractors to develop oil and gas fields. Nonetheless projects in this industry, as of the projects in the construction industry in... 

The aim of the current research is to study the process of making a solidstate nanopore by molding from PDMS polymer and to make a laboratory sample of a solidstate nanopore manufacturing device using this method. Solid-state nanopores are used to control ion transport in microfluidic channels,lab-on-a-chip detection to study nucleic acids and proteins, desalination, nanofluidic transistors,single-cell sensing tools, and particle classification. In general, the smaller the nanopore, the shorter the length and the higher the mechanical stability, the better the performance. In this research, chips have been made on which there is a blade with a sharpness of 10 nanometers and a height of 10... 

Internal combustion engines are first and common powertrains in industry. They have developed eminently. Because of energy crisis there are much attention for their improving and optimizing. The purpose of improving of internal combustion engines performance is increasing the ratio of output brake power to engine fixed size. An improved engine should be tried to work near of the maximum power span, whereas an automobile engine (original engine) works at its middle power. In other hand, if an improved engine and original engine work for a long time, improved engine has critical conditions. In attention to above discussions, improving and reforming of an improved engine cooling system are... 

In the presented dissertation an analytical model is developed for the air gap flux density and the cogging torque in the axial flux surface-mounted PM machines. The slotting effect is taken into account in the magnetic flux distribution.The model is derived from solving the 2D Poisson' equation in the slotted air gap. To simplify the solution process, the concept of the uniqueness theorem is used to replace the slotted air gap by a slotless one and some surface current distribution. In addition, the separation of variables method is applied to the analytical solution of the Poisson equation. However, the proposed 2D analytical model is developed for the quasi 3D model by the well-known...