Sharif Digital Repository

This thesis is divided into three parts: In part I, interactions of neutral and anionic forms of histidine with coinage metal nano clusters M3 (M = Au, Ag and Cu) are investigated. Results demonstrate that nonconventional M…H-O hydrogen bonds and M-X bonds (X = N, O) play stabilization roles in interactions of histidine and metal nano clusters. Presence of negative charge in ligand leads to increase of binding energy of complexes. In the next step, the effects of coinage metal nano clusters on the gas-phase acidity of weak organic acid (histidine) have been explored. The acidity of isolated histidine is compared with the acidity of its Au3–, Ag3– and Cu3–complexed species. Moreover, pKa... 

Increasing the complexity of software systems, their ubiquitous presence in the human activities, and necessity to preserving the functional and nonfunctional requirements of the systems under an uncertain environment, increase the need for self-adaptive systems. A self-adaptive system changes its structure and behaviors in response to changes in its environment and the system itself. A key research challenge in the self-adaptive community is to guarantee that the system fulfills its requirements. This issue can be addressed by employing formal methods during the design of the software systems. However, the assurance techniques should be used during the execution of the system as well as the... 

Given that the most polluting industries in the country there. A suitable treatment system for degradation of these compounds is necessary unless unexpected effect on environment will occur.Moving Bed Biofilm Reactor (MBBR) was developed to adopt the best features of the activated sludge process as well as those of the biofilter processes. MBBR has biomass growth on carriers that move freely in the water volume of the reactor. High surface area of carriers make a good condition for biomass attached growth. This system has had good operation in the urban and some industrial wastewaters.In this study, four reactor volume of approximately 16 litr and 6, respectively, in the aerobic, anoxic... 

Visibility graph is a graph that comprises information about visibility of a set of objects in 2 or 3-dimensional space. By constructing this graph with respect to conditions of environment one can answer questions like minimum Euclidean distance. Inverse of this procedure is required too; i.e. knowing geometrical structure of objects and information about their visibility we want to guess their location in space and, as the saying goes, reconstruct the environment. For example some methods to reconstruct specific polygons knowing which vertices each vertex sees is proposed. In this dissertation we try to reconstruct a 2-dimensional environment that only has two x-monotone paths (chains)  

Signal transmission of information on noiseless and lossy channels is an important issue in data transmission. Using the amplifier in the transmission channels is a good solution to help send information on longer channels. In classical communication, information can be coded in the amplitude or phase of the field and an amplifier is responsible for amplifying these parameters. If we consider the conditions ideal and ignore electrical noises, Classical mechanics does not impose any restrictions on the amplification of arbitrary classical signals. Instead, in quantum telecommunications the information encoded on the quadrature of the electromagnetic field are mounted on quantum states, such... 

Loosening of uncemented tibial component is one the most common causes of total knee prosthesis failure which is a result of short-term factors such as instability and incomplete osseointegration as well as long-term factors such as peri-prosthetic stress shielding and bone atrophy. Porous cellular structures for tibial stem have been considered as a solution to this problem. This project is aimed to achieve an optimal gradient porous cellular design of tibial stem that in addition to sufficient mechanical strength, provides a perfect osseointegration and prevents bone resorption by incorporating appropriate porosity size, small micro-motion and favorable stress distribution on bone. A... 

The world around us changes almost every second, so the economy in this world feels it more by every single minute. When we look at the organizational structures, they experience lots of things for keeping the companies competitive and the human resources have the main role among the other stimulating factors.The human resource management and its improvements have done a lot in this century to organize and manage the human problems in organizations. After that those companies that had more effective strategies become on top of this important management system. By changing fast the work models companies experience more and immediate changes that may not happen even through the years. In this... 

The electronic health system plays a crucial role in modern healthcare, facilitating efficient data management, secure information exchange, and improved patient care. However, existing systems often face challenges related to security, privacy, scalability, and interoperability. The primary objectives of this study are proposing a system that ensures data security, patient and peer privacy, scalability, data integrity, deniability, traceability, secure data sharing, access control, transparency, real-time monitoring, and security in the drug supply chain. To achieve these objectives, we have proposed a system that encompasses a wide range of requirements of healthcare system. To enhance... 

The aim of this research was estimation of investment-specific technological change, using industrial database which is published annually by Bureau of Statistics of Iran. Investment-specific technological change is the quality improvement of investment in capital goods during the time. Before estimation of this rate, production function (regarding 130 industrial activities and during 14 years, 1994-2007) was estimated. All industries classified in 4 groups based on the level of technology used in them. Then factor’s production elasticities were compared between different groups of industries. The results showed that in high-tech industries the elasticities of skilled workers, import and... 

Small strain shear modulus, Gmax, is one of the most important parameters for characterization of the behavior of earth structures subjected to static or dynamic loading conditions. This research presents an experimental laboratory study on the effect of non-plastic fines content and hydraulic hysteresis on the maximum shear modulus of unsaturated sand-silt mixtures. In this regard, clean Firoozkuh No. 161 silica sand which is classified as poorly graded uniform sand was mixed with different percentages of silica non-plastic silt. A set of bender element tests were planned to carry out implementing two modified triaxial devices. The modifications on these two apparatus were to add HAV... 

This existing research has been conducted to reach quick evaluation instructions to pipe earthquake damages in the piping systems inside the industrial complexes. In the old complexes of such kinds there are cases where field inspections and quality evaluations are urgently required subject to peculiar conditions affecting each piping system inside the units and in certain cases subject to lack of access to the as built-drawings. However, so far any definite instruction hasn’t been available for a quick evaluation of likely damages in piping system: all because of various pipe types, complexity of pipes geometry, different temperatures and pressures in different sections. In this research...