Sharif Digital Repository

Energy conversion and storage as well as life sciences are among the areas of our daily life. Interest in carbon nanomaterials for energy storage systems such as supercapacitors has enormously risen due to their attractive electrical conductivity, chemical inertness, and charge storage capacity. Producing these nanomaterials with a simple, scalable, and cost-effective method is the major problem for commercializing them. The reduction of graphitic oxide is a versatile procedure to prepare 3D graphene. Despite many green methods, the dynamics behind ultrafast thermal graphitization have remained elusive. Here, we demonstrate an effort to understand the graphitization mechanism of graphitic... 

Energy is of the essential elements to improve every nation’s economy and society, which is influenced by a variety of parameters. Thus many empirical methods have been represented to assess the said parameters using other parameters by which they are affected. In this research, Linear Genetic Programming method (LGP) has been used for assessment, which has been applied to project the global shining of the sun in two Iranian metropolises (Tehran and Kerman), and also natural gas utilization in both industrial and domestic sectors. In this research, authentic data from the empirical results existing in technical documents has been used to develop the models. Most prevalent effective... 

During last century, one of the most important philosophy of religious field issues, especially after 1950 was religious language. In other words, one of the most important and affective problems which could attract philosophers was religious language problem. This issue also has a history resume. Ask about religious language, at least could be seen by philosophers of Abrahamic religion like Islam and Christian. However, during last century due to philosophic attention to the language, religious language became for another time, an important problem. In this thesis, first of all, a geographic view of questions and answers will be caught by reviewing theories, from past until now. This would... 

In recent years, highly recommended systems have been used in various areas. One of the approaches of these systems is a collaborative refinement that consists of three user-based, item-based, and matrix-based parsing. Matrix degradation methods are more effective because they allow us to discover the hidden features that exist between user and item interactions and help us better predict recommendations. The low-level mapping method is designed to store and process very high volume of data. In this method, after completing computations in the author’s nodes, the data is sent to the downsizing nodes, which is referred to as ”data spoofing”. It has been observed that in many applications, the... 

Wireless Multimedia Sensor Networks (WMSNs) have many applications in survilient systems. In this kind of applications, although we have limited energy and computational power, we should provide minimal security to transfer data in such networks. These constraints are more crucial when we use multimedia that has more data for processing and transmission. Because of this huge amount of data, we must use compression for using less energy in both processing and transmission.
In some algorithms, it has been proposed to integrate compression and encryption in order to decrease time and power consumption. The proposed algorithm is several times faster than AES (Advanced Encryption Standard) or... 

Pelamis is a semi-submersible device that can extract wave energy and converters that to electrical power. It has 5 cylindrical structure that connects through the joints. This device takes the shape of wave and the wave forces tubes to had angular relative motion together. The Main task of this device is to convert the angular movements of tubes to the Linear movement of pistons. External mechanism called the energy capture device are responsible for absorbing wave energy through angular movements, and then the internal mechanism, called the Power Take-Off, are responsible for converting this energy into the electrical power for use in the electricity grid. This device was designed and... 

Knock is an abnormal phenomena in combustion engines and one the main limiter elements in increasing engine efficiency. From years ago, recognition and elimination of this phenomenon had studied by investigators and various approaches to anticipation had presented. One of the newest methods is using of property variety in air and fuel mixture with using technologies like Variable Valve Timing (VVT) system.
The purpose of this work is development a simple model in basis physics of 3 zone, homogeneous, ignition combustion with a partial kinetics model that this model can predict the knock phenomenon onset with good precision for various qualities of mixture. This study survey effect of... 

The explosive growth of battery operated devices has made low-power design a priority in recent years. Moreover, embedded SRAM units have become an important block in modern SoCs. The increasing number of transistor count in the SRAM units and the surging leakage current of the MOS transistors in the scaled technologies have made the SRAM unit a power hungry block from both dynamic and static perspectives. One of the key strategies for reducing power consumption is reducing the supply voltage to near or below the threshold voltage of the transistor. However, as supply voltage decreases to tackle the power consumption, the data stability of the SRAM cells have become a major concern in recent...