Sharif Digital Repository

By combustion, waste toxic, flammable and corrosive materials are changed to less inviromental problems by combustion. It also creats environmental problems (the most serios problem is caused by burning gases), as well as economic resources are wasted. So several ways was investigated to reduce combustion gases. Mini-methanol plant is one of varios possible ways that can convert these gases in to methanol. So methanol plant was simulated and then pinch analysis was performed on the simulated plant. Performing of pinch analysis caused 94.5 percent and 25 percent reduction in amaunt of hot and cold utility respectively. Before and after pinch analysis, the exergy analysis was performed on... 

Cell lysis, as the first procedure of cell pretreatment, is a process that breaks cell membranes open thereby facilitating access to intracellular substances, such as DNA, proteins, and other components for further analysis to diagnose and treat diseases at early stages. Currently, there are several methods for cell lysis at macroscales. However, the time-consuming and expensive procedures as well as the large scal of the system are the main disadvantages of the systems. Recently, microfluidic systems have attracted considerable attention due to advantages associated with automation, integration and miniaturization of biomedical test protocols. Centrifugal microfluidics (Lab-on-a-Disc) is a... 

Mass transfer and axial dispersion coefficients for continues phase were calculated by axial mixing model for continues phase and forward mixing model for dispersed phase simultaneously. Experimental data was achieved in pulsed sieve plate column with 22 cm diameter. Toluene –water-acetone and Butanol-Succinic acid- water were used in this experiment. In these systems continues phase is water and mass transfer takes place from continues phase to dispersed phase. Experimental data involves drop size distributions and operating conditions andconcentration in both phases.For calculating overall mass transfer coefficient for drops the handlos and Baron Model was used. The axial dispersion... 

In this thesis a novel T type scheme for direct ac/ac converters is proposed. In this topology, frequency changing takes place directly (without common DC voltage bus) through three converters that are connected in a T structure. H-bridge converters are implemented in each branches of T to make the proposed converter. Also, multilevel inverters, specially cascaded H-bridge ones can be used in branches of T. this will lead to a multilevel ac/ac converter that is suitable for high power applications such as intertie connections and high power motor drives. Using half-bridge converters as T branch converters, leads to an ac/ac converter with unity power factor by only six semiconductor... 

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... 

Home health care is one of the newest methods of providing services to patients in developed societies that can respond to the individual lifestyle of the modern age and increase of life expectancy. In this study, a new mathematical model is developed taking into account the flexibility of starting and ending locations of each nurse, according to the specific requirements of each service. In this context, there are some special services that require the picking of materials and health equipment from laboratory or force the nurse to return to laboratory to deliver the specimens and equipment. In the next step, this model is expanded to downgrading aspects by adding the objective of minimizing... 

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... 

Understanding biological systems requires extensive knowledge of individual parameters, and to study the processes of cell differentiation and cell behavior, a suitable environment must be created with the physiological conditions of the human body. For this purpose, with the knowledge of microfluidics, a microenvironment can be provided to study the behavior of cells on a small scale. The use of bone tissue model microfluidic chips is an alternative and new method in which it is possible to study the behavior of cells to differentiate into bone and to examine the toxicity of drugs, which in itself can help in the effective and successful treatment of these cases show. Therefore, in this... 

The main topic of this research is the navigation and control of a free-flying satellite with a robot manipulator while transferring and placing cargo on a space station. After connecting the cargo module, astronauts and robots need to deliver the available loads to the desired modules in a space station. Capturing an object or cargo is a critical issue studied extensively so far. However, delivery and placing of the cargo at the target point have not been investigated yet, to the best of the author’s knowledge; hence, this is a primary motivation for conducting the proposed research. After capturing the payload, the position and attitude of the manipulator with respect to the station’s...