Sharif Digital Repository

Three sizes of silica nanoparticles (160±7, 450±10 and 600±25) were sythetized via template-removing method. The synthetized nanoparticles were functionalized with N-(2-aminoethyl)-3-aminopropyl trimethoxy-silane (EDS) to provide a positive charge on the surface of nanoparticles. BET analysis showed that the average pore diameter, surface area and pore volume of nanoparticles were 2.3 nm, 769 m2.g-1 and 0.44 cm3.g-1, respectively. showed that the Amine-functionalized silica nanoparticles were used to enhance the application of alginate polymer for 3D encapsulation of mammalian cells. Incorporating of silica nanoparticles can be suitable for the bead integrity and attachement of mammalian... 

Oscillators in microwave communication systems play very important role. Therefore, designing an oscillator with a good performance, influences the final performance of the system. One of the parameters that determine the performance of an oscillator is the phase noise. This parameter in systems that have a large number of adjacent frequency channels, is causing many problems. Therefore, designing an oscillator with low phase noise improves the entire system performance.
Microwave oscillator phase noise is influenced by various factors, which one of the most important is the resonator. In microwave applications cavities have small sizes, thus it is difficult to use of them. Thus, in... 

In tall buildings, seismic behavior depends on structural elements and their configuration. The usefulness of shear walls in the structural planning of multistory buildings has long been recognized. When walls are situated in advantageous positions in a building, they can be very efficient in resisting lateral loads originating from wind or earthquakes. Restriction in surrounding effects and the architectural design may contribute to have asymmetry in plan. In a number of papers, published mainly in the last decade, the analysis and design of shear walls has been studied. But just a few of them considered arrangement of shear walls to find the optimum layout. In the present study, analysis... 

Nowadays, advanced and inexpensive pre-clinical methods for investigating the effects of anti-cancer drugs are expanding. One of the latest three-dimensional laboratory modeling for evaluating the effects of drugs is the use of tumor-on-chip technology, which actually models the physiological system of the body through three-dimensional scaffolds, multicellular cultures, and shaped vascular systems. In this study, three-dimensional culture of cancer cells was performed in the form of spheroids. A chip of U-shaped microstructures with and without gaps was used to trap cells and form cancer spheroids. We simulated the simultaneous effect of drug and oxygen concentration distribution inside the... 

The case of rapid small satellite aerial launch by mother airplane has various applications; such as space experiment, weather monitoring, and getting information from the earth monitoring during natural disasters. In this method, the satellite and the launch vehicle will be carried up by mother airplane to the definite height; then, the launch vehicle will be released and flied - to the insert of satellite into the desired orbit. Aerial launch system success depends on a set of complex elements and their interactions. In the present study, first of all, the element interactions will be investigated by system engineering approach based on operational scenarios; then, a new approach for... 

Facility Layout Problem (FLP) is known as one of the classical problems in industrial engineering which have acquired high attractiveness to researchers. Therefore, in this study, a practical mathematical model is formulated and solved
In order to have a real and practical model, robust optimization is applied to FLP. Therefore, it is supposed to have dynamic values for departments' dimensions. This assumption is very critical to generate an effective and acceptable layout. We consider that each dimension of a department can be changed in a given interval. Due to this assumption, we introduce two new parameters which are called width and length deviation coefficients, respectively.... 

Among scientific fields of study, mathematical programming has high status and its importance has led researchers to develop accurate models and effective solving approaches to addressing optimization problems. In particular, meta-heuristic algorithms are approximate methods for solving optimization problems whereby good (not necessarily optimum) solutions can be generated via their implementation. In this study, we propose a population-based meta-heuristic algorithm according to chemotherapy method to cure cancers that mainly search the infeasible region. As in chemotherapy, Chemotherapy Science Algorithm (CSA) tries to kill inappropriate solutions (cancers and bad cells of the human body);... 

Robotic Operating System (ROS) is an open source software framework, developed for the needs of robotics software developers and now it has become the standard ¬¬in this area. In this thesis, in order to propose an approach to verification of ROS-based softwares, we defined the mapping from Rebeca modeling language to ROS. To reach this aim, we have studied the main ROS concepts and investigated several ROS-based systems syntactically and operationally. Our mapping includes specifying the corresponding conceptual and syntactical components between Rebeca and ROS, and proposing an algorithm to convert any Rebeca code to the ROS code. We also have developed a tool to automate this conversion.... 

Corneal perforations are one of the most widespread illnesses which are associated with severe pains and vision loss. Eyes with corneal perforations must be treated immediately in order to preserve its morphology and prohibit secondary complications. Opthalmologist usually apply cyanoacrylate and fibrin glues for filling and sealing incisions, but they have several drawbacks besides their advantages. Cyanoacrylates which are unabsorbable remains as a foreign body in the patient’s eyes and will cause annoyment. Fibrin glues that are attained from ibrinogen and thrombin, can transfer blood diseases. Therefore, fabricating a bioadhesive with high biocompatibility, adhesion and... 

Modeling and performance evaluation of the real time distributed systems is a significant problem. Stochastic activity network is one of the high level models used for this purpose. This network is an extension of generalized stochastic Petri net which is more powerful and flexible than other Petri net extensions. Checking the satisfiability of properties such as performance, dependability and user's expected properties is considerable in these models. Thus, using the approaches and generating modeling and model checking tools with the mentioned purpose is attractive. A model checker automatically checks the correctness of the system behaviors as properties against the model by getting the... 

This study has focused on the important problem of landing on a planet as an important current and future space mission. In this regard, dynamics modeling and integrated state estimation and control problems have been investigated in different views. To this aim, first a novel concurrent representation for translational and rotational kinematics has been developed based on the extension of modified Rodrigues parameters to dual space. This parameter set, called dual modified Rodrigues parameters (DMRP), is then utilized to establish an integrated roto-translational dynamic. The proposed DMRP-based kinematics and dynamics have been verified via comparison to traditional methods of... 

Prevalent deployment of Distributed Energy Resources(DERs) in the demand side of electrical energy grids has several advantages such as greenhouse gases emission reduction, mitigation of power losses in the distribution grids and abatement of the dependency on the wholesale generation companies. At the same time, it paves the way for the advent of local interactive energy trading frameworks. In the following thesis, a distributed data-driven algorithm is developed for market-clearing in a community-based local energy market. The social welfare maximization is considered as the objective of the energy trading. The production and demand of electricity are the decision variables of sellers and...