Sharif Digital Repository

This project is aimed to design a controller for nonlinear systems that satisfy a prescribed performance while guaranteeing close-loop stability. To do this, the controller must be designed in such a way that the transient response of the system has had these performance indices and does not exceed them. These performance indices predefine some constraints for systems’ output.A comprehensive form for the model system, the unknown dynamics of the system, consideration of a variety of constraints on the system input, usage of the time-finite method for the residence time and consideration of just one tuning parameter to reduce the computation load, are among the other benefits for the proposed... 

The applications of science and technology of materials grows rapidly nowadays One of the major aspect of this science discuss about the growth of thin films via deposition of molecules and atoms. By this way we can diagnose physical and chemical properties of thin films whose applications in electronics, computer, microelectronic industry, material engineering telecommunications and so advances every day. In this way we smell out the process of the growth of diamond like carbon (DLC) thin films whose importance is extended nowadays. By acknowledgement of variables that influence the dynamics of film formation we make a big jump in attaining the optical, physical and electrical properties of... 

Conjugation of proteins to nanoparticles has numerous applications in sensing, imaging, delivery, catalysis, therapy and control of protein structure and activity. Therefore, characterizing the nanoparticle–protein interface is of great importance. A variety of covalent and non-covalent linking chemistries have been reported for nanoparticle attachment. Typically, a specific protein residue is linked directly to the nanoparticle core or to the ligand. As conjugation often affects the protein structure and function, techniques to probe structure and activity are assessed Characterization studies of nanoparticle–protein complexes show that the structure and function are influenced by the... 

Soil-Structure Interaction (SSI) has been widely studied theoretically and experimentally due to its importance effects on the responses of structures. In experimental studies, acceleration responses recorded during previous earthquakes are generally used in order to investigate the contribution of underlying soil to the response of soil-structure systems. Since acceleration responses are affected by higher modes of vibration, studying the effect of SSI on dynamic characteristics of higher modes are of great importance in these studies. However recent theoretical studies indicate that the influence of SSI on the higher vibrational modes is very much dependent on the behavioral model (bending... 

In elliptic curves equation, if the number of solution is infinite, complication of calculation increase quickly. Even the simplest solutioncan be large. y2 + y = x35115523309x − 140826120488927 The x-coordinate number of smallest solution has 5454 digits. The theorem of Mordell and Weil states that “The set E(Q) of rational solutions has the structure of an infinitely generated abelian group.” E(Q) = (Z)rankE(Q) ⊕T Can the rank be arbitrary large? The current record is rank(E)=28.Manjul Behargava has recently made progress on the study of the average rank for all elliptic curves with rational coefficient. Every such curve has a unique equation of the form y2 = x3 +Ax+B, where A and B are... 

Since expansion of communication technology, telecommuting has gained attention from transportation planners as an approach in field of demand management. In this research, joint effects of feasibility of telecommuting for the employees of each organization and the relevant frequency of employees have been evaluated by using the copula model as the most recent conventional way of developing a joint model since the last few years. The result of telecommuting acceptance is that after presenting the project to each organization, the head employer measures the appropriateness of the project for employees and if he reaches a consensus on the success of the project, the employees get involved and... 

Droplet formation and breakup processes are one of the important steps in many microfluidic devices with a wide range of biological and chemical applications. The purpose of this study is numerical simulation of non-Newtonian droplet formation under the influence of electric field in a microfluidic system. The innovation aspect of this project is the use of non-Newtonian fluid in this process, which, despite many applications in real issues, has been less studied, and in most of the previous researches, Newtonian fluid assumption has been used to simplify the solving. Also, simultaneously, the effects of an external electric field on this process were also studied. Carboxymethyl cellulose... 

Nowadays, the inside needle capillary adsorption trap (INCAT) technique as a solventless sample preparation approach and alternative extraction method derived from SPME is gaining rising attentions. The INCAT and needle-trap devices are inexpensive, robust, reusable, and are applicable for sampling and analyzing suitable organic compounds from many different sample matrices. Compared to the fragile silica-based SPME fiber, the needle device is nearly impossible to break mechanically. In addition, the extraction medium possesses quite a large extraction phase volume and a powerful preconcentration capability. Similar to SPME, needle-like devices are particularly convenient for automation and... 

The nickel-based superalloys play a key role in the development of aircraft and power-generation turbines due to their exceptional properties of high temperature strength, toughness, crack growth resistance and resistance to degradation corrosive and oxidisation environment.In this thesis, the role of base metal composition in isothermal solidification time during diffusion brazing of Nickel-based super alloys was investigated. To achieve this aim, four different super alloys Hynes230, Hastalloy X, Nimonic 263 and Monel were used in similar joining systems. Systems of H230/H230, HX/HX, C263/C263, and Monel/Monel were joined by BNi2 interlayer at 1323K and for different times, until the... 

Recently, due to the increase of environmental concerns, a significant raise in applying films and packaging containers, pollution produced from petroleum-based plastics packaging and problems arising from the various methods of waste disposal, the researchers have concentrate to replace these materials with biodegradable ones. In this study, a nanocomposite based on alloy matrix of thermoplastic starch and polyethylene which is reinforced with different amounts of Montmorillonitenanoclay has been constructed by the extrusion process. Furthermore, in order to increase the compatibility between the polar and non-polar components in the group of samples, compatibilizer was used and its... 

Performance of civil infrastructures, such as high-rise buildings, bridges, tunnels, offshore platforms and other structures may be critically influenced by existence of structural damages or even lead to devastating consequences. Structural Health Monitoring(SHM) and damage detection denotes the ability to monitor the performance of structure, detect and assess any damage at the earliest stage in order to reduce the life-cycle cost of structure and improve its reliability and safety. Generally, damage is defined as some changes in the physical properties of a structure, such as stiffness matrix. On the other hand, presence of damage causes changes in structural dynamic characteristics, such... 

This paper proposes a novel probabilistic approach to account for soil-structure interaction (SSI) in the seismic design of building structures. In this approach, an SSI response modification factor, RSSI, is introduced to capture SSI effects on the seismic performance of structures. The proposed procedure quantifies RSSI such that the probability distribution of the collapse capacity of the structure designed to account for SSI concurs with that of the structure designed using the default fixed-base provisions. The proposed approach is employed for special steel moment frame buildings with surface foundation. A surrogate single degree of freedom (SDOF) system is developed in this study and... 

In recent years with the growth and development of emerging technologies, one of the main challenges in various organizations is the issue of Business-IT Alignment programs at different levels of strategic, tactical, and operational. Many managers and experts in the field of information technology recognize the importance of this issue because of its broad effects on the development and maturity of the organization. However, they face various difficulties in creating actionable plans to achieve high levels of alignment. The main problem is the inability to measure the alignment degree index. This index is affected by various sub-indicators in various fields of business and information... 

Queue is crucial in new atmosphere of business. Firms and people see the dark side of this phenomenon. Investigation on The other side of queue is our main purpose of this study. Examining the relationship between queue and Perceived Quality, Price, Sacrifice, Value, and willingness to buy that make our conceptual framework and hypotheses is our primary objective.Questionnaire designed for evaluating construct. For each construct, standard scale was used. A survey was conducted in Iranian universities. The final sample includes 295 respondents. Regression analyses were performed.Results show significant relationship between our construct that confirm the other side of queue. Results show...