Sharif Digital Repository

Systems composed of electrical and mechanical elements in micrometer scale are called microelectromechanical systems which are commonly fabricated on silicon substrates. These systems are in connection with environment by the means of sensors and actuators. Thermal microactuators as one of the most applicable actuators produce force and displacement on the basis of thermal expansion.Recently, by the advent of some polymers compatible with microfabrication methods such as SU8 and due to their remarkable thermal properties,polymeric thermal microactuators are attracting more attention in a way that polymeric type of almost every predesigned thermal microactuators are fabricated and much... 

In order to improve the performance of structures against earthquake loads, engineers believe that both minimizing the rigidity and maximizing the ductility; can lead to minimization of the energy input of the structure. However, the minimized energy shall be depreciated as much as possible in different stories so that the damage to the main and Irreplaceable structural members remains as low as possible.
Steel with high strength and ductility is relatively an ideal material for this purpose; however, the ductility level of this material is much higher than that is normally in use. In order to have a better utilization of the steel ductility, RBS (Ribbed Bracing System) was invented in... 

In this research application of Ionic Polymer Metal Composite (IPMC) as actuator in a deformable ring capable of locomotion is studied. Such a deformable ring moves as a result of gravitational force acting on its body when its shape changes. A deformable robot made of IPMC can be used in exploration, search and rescue missions in future, where using conventional robots with rigid bodies and actuators is impossible. Large deformation induced by small stimulating voltage, low stiffness and the sensing characteristics that in future work can be used in feedback control make IPMC a good choice for such an application. In this work first a model for IPMC is introduce that can be used in... 

Social Studies of Science have been taken seriously for some decade recently. The need to these studies after Kuhn is felt in “ The Structure of Scientific Revolution”. One of these approach, allocating to social studies of Scientific Institution, is the so called approach social constructivism. Followers of this approach take Science and scientific discoveris some kind of the Social Constructivism of scintists. Bruno Latour is one of the most famous theorisian of this approach. Studing the laboratory practies, Latour is tring to know about the bihaviour and interaction of scientists. The result of this endivour is “Laboratory Life”, the grand book. Latour is the famous person in the field... 

The discovery of Iron-based superconductors with maximum transition temperature of 56 Kelvin and High critical magnetic field of the order of 50T at temperature 20K has created evolution in different fields of superconductivity including practical issues. BaFe2As2 family is one of the most important compounds of Iron-based superconductors and with different doping elements for instanse elements of the first column like Potassium inters superconducting state with critical temperature of 36K.
The purpose of this thesis is to localize the technology of making this compound in Iran which no project has been done in this field in the country before. In this thesis manufacturing, Optimization... 

Fuel cell is a power generator like internal combustion engines, but the first point is that internal combustion engines produce mechanical power while fuel cells produce electrical power. Secondly, internal combustion engines use hydrocarbon derivatives such as gas as fuel and their exhaust fumes are toxic gaseous, but fuel cells use hydrogen as fuel and their exhaust are only water in either vapor or liquid form. One of the most important issues in fuel cells is optimum design of micro channels of bipolar plates which is different regarding the type and application of fuel cells. Optimum designing of micro channels on bipolar plates plays a key role in fluid mass transport through micro... 

Exoskeleton is a wearable active device used to augment human power in upper or lower extremities. The integration of robotic devices and conventional physiotherapy is becoming more and more acceptable worldwide. The main scope of this thesis is to design and develop a prototype of a light, low-cost and wearable robotic exoskeleton to rehabilitate the upper extremity in stroke patients at home. For this purpose mechanism of a wearable exoskeleton will be proposed compatible with upper extremity degrees of freedoms with minimum number of actuators which is constructed inexpensively to eliminate the demand of expensive and professional therapists. The conceptual design of such a system should... 

Regarding the price of industrial turbo machines, testing the rotating elements of them is always an important issue. One of the companies of the aviation industry decided to design and fabricate a spin tester device to check the quality of new rotating parts before installing them on gas turbines. A team has worked on this project for more than a one year. The present thesis is on designing the drive system of the spin tester. The drive system was chosen to be an air motor. This thesis concentrates on the design procedure of this air motor. The designed system is capable of providing enough power to accelerate the disks to the test speed in the appropriate time. The disk geometry, test... 

Schools are known as the educational infrastructure of countries. Most people in the community spend more than 12 years of their education in schools. The organization for development, renovation, and equipping of in Iran, as the custodian of school construction in the country, has moved towards using new technologies due to the problems encountered in schools' construction. Among these tools, BIM is selected to help project management and control. For BIM implementation on the macro scale, readiness assessment plays a significant role. In this dissertation, an attempt has been made to provide a model for evaluating the needs, use BIM, and evaluate the organization by having a strategic...