Sharif Digital Repository

This project presents appropriate strategies for HIV infection treatment. In order to close the presented strategy to real treatment regimen, appropriate parameters are selected for the HIV infection model, real outputs are considered for the system, and three widely used drugs (one PI: ritonavir (RDV), two RTIs: lamivudine (3TC) and zidovudine (ZDV)) are used to design a drug regimen. A Luenberger-like nonlinear observer (LNO) is also designed for estimation of unmeasurable states. In order to minimize the side effects of drug regimen, the concentration of ZDV is fixed at a minimum value at all time because this drug has a greater side effects than other drugs and the parameters of... 

Many researches have been made on super hydrophobic and photocatalyst nano coatings in the last decades as a solution to some environmental issues. Among all semiconductors chosen for this property, titanium dioxide is often used because of it's low cost, ease of accessibility and stability in different chemical circumstances to break up organic pollutions. Mixing this property of TiO2 with hydrophobic manner of SiO2 causes a superhydrophobe & photocatalyst nano coating. Doping TiO2 with another semiconductor may also improve photocatalytic behavior of coating by increasing surface area of reaction or decreasing the band-gap.In this research TiO2-SiO2 hybrid nano coating is made via... 

In the ship designing, it is preferable to access to a good performance in waves and low efficiency loss. Accordingly, modeling and estimation of added resistance would be an important issue. Added resistance in wave is an important part of ship's performance due to many technical and economic effects on the ship's performance. With understanding and awareness of the added resistance that comes from ship accident to the waves, we can reduce this parameter by changing in specifications and hull form of ships. Designers are also interested in optimizing the ship from this aspect. In previous works, added resistance in waves was obtained from experimental, numerical and analytical methods. In... 

Design optimization of ships by taking maneuverability in account has great influence on the performance of the vessels. Thus providing a method to predict the behavior of vessel in the design process is very important. Ship maneuverability is remarkable from different aspects of view. Especially in high speed vessels of various applications and missions’ good maneuverability would be a positive rating for it. For example, military vessels in specific situations need to change the speed and direction and this is a crucial capability of them. Also in accordance to the rules of IMO all of the vessels should perform maneuvering trials and fulfil the minimum requirements. Accordingly, this issue... 

Aircraft Range extension is a very common modification for today’s aircraft. Using the conformal fuel tanks is an appropriate method for today’s military and civil aircraft. In this thesis, a Design method has been developed for designing these tanks using DSM, CFD and DOE. The main goal in developing the method was to be able to consider these tanks as an add-on feature for the aircraft, which can be designed after the aircraft production. The main aspects of designing the tanks was to identify the consequences of adding the tanks to the aircraft. Due to limited resources, only the Longitudinal static and dynamic stability of the aircraft has been considered.The method introduced here shows... 

Conjugated linoleic acid (CLA), a mixture of positional and geometrical isomers of linoleic acid with conjugated double bonds, has gained considerable attention because of its anticarcinogenic and obesity treatment properties. The most biologically active CLA isomers are 9c, 11t-18:2 and 10t, 12c-18:2. The aim of this study is to separate and purify the two essential isomers via enzymatic method by Candida rugosa lipase and chemical method by urea crystallization and also optimization of reaction conditions in order to better separation. For enzymatic purification, L-menthol and Lauryl alcohol were used separately. Optimization of reaction conditions by enzyme content, time and the ratio of... 

In this study, the influence of eutectic modification, grain refining and cooling rate on amount of shrinkage porosity in aluminium A356 alloy were investigated. Modification process for changing the morphology of eutectic silicon from needle like to fibrous like, use in aluminium – silicon alloys. This process often leads to increasing porosity in melt and affect harmfully on mechanical properties. For studying shrinkage porosity, the melt degassed completely to minimizing amount of gas in the melt. For modification, strontium in Al-10Sr master alloy and sodium in NaF salt used and for grain refining Al-10Ti and Al-5Ti-1B master alloys used. To study the effect of cooling rate, three mold... 

This thesis analyses the relationship between performance and capital structure of listed companies in the Tehran stock exchange. For examining this relationship, we use trade-off theory. This theory states that using debt comes with some benefits and costs for the company. If this theory holds true, we expect that in a low debt capital structure, as a result of benefits of using debt surpasses the costs of it, the relationship between debt and performance should be positive and in a high debt capital structure, as a result of costs of using debt surpasses the benefits of it, using more debt should have negative relationship with performance. For examining this relationship, we first gather... 

Successful performance of forward heuristic planners in classical planning, has motivated the use of forward heuristic search in many temporal planners. Most of forward temporal planners are decision epoch planners that use an explicit representation of time and schedule actions while searching. However, decision epoch planners aren’t complete and cannot solve certain temporal problems with required concurrency. In this dissertation, we present ATFP, a forward temporal planner that does not use an explicit representation of time. In ATFP, duration of actions are temporarily ignored, and a causally valid order of beginnings and endings of actions is searched using classical forward heuristic... 

We calculate NJL-Model free energy throughthe finite- temperature methods.Then according to the energy-gap equation, we determine symmetric and anti-symmetric phases under Chiral Transformation, in different regions of the phase diagram,with chemical potential() and temperature(T)as control parameter. We conclude with comparing the result of the finite temperature expansion to nonzero chemical potential to the result of,T=0 and finite ,andT=μregime.
 

This research investigates the impact of Bitcoin and cryptocurrency news along with macroeconomic and financial indicators, on Bitcoin price fluctuations for two years (May 2016-2018). The reason for this examination is due to high variations of Bitcoin price in the late 2017 and beginning of 2018, while academic research focusing on Bitcoin price are mostly conducted before 2017. Findings show that the number of news with positive and negative contexts, and news related to cryptocurrency technology have a direct relationship with Bitcoin price change. The other result shows that among news concentrated on Bitcoin, the most effective is regarding adverse incidents, famous people concerns and... 

In drilling the percolation structure reservoirs (such as offshore Channelized reservoirs), one of the most important factors in the effectiveness of wells is drilling permeable areas (Channels), while Channel constraints make it possible for two wells to collide. On the other hand, if the desired reservoir is an offshore reservoir, these restrictions have been increased because usually several wells are drilled near together from one platform. Therefore, proper well collision analysis method is also important in these situations. In this project, anti-collision analysis is performed using the MWD device error model between two or more wells in a static reservoir model with channel... 

Over the past two decades, in developed countries, public-private partnerships have been used as a mechanism to provide the required infrastructure by using private sector capacity. Risk management is the most critical factor in achieving optimal "value for money" in this type of project. In Iran, this is still far from its maturity and the growing trend of adopting this method and the vacuum of its academic literature in the country, necessitate such research. This study has been written to solve this problem due to the lack of risk management framework in the contracts of Tehran Municipality's Partnerships Organization. This dissertation covers three stages of risk management, which... 

Radial turbines with small dimensions and in small power capacities are of great interest. In general, turbine performance improvement and higher output power may be achieved through increasing the inlet mass flow rates however at the expense of more weight and larger dimensions. On the other hand, increasing the inlet total temperature to the turbine will result in higher power potentials. Nevertheless, the turbine needs to be cooled in case that the intended inlet temperature goes beyond the turbine material limitation. In this thesis, radial turbine equations are reviewed and the logic of a 1D algorithm is developed where parameters like the total temperature, total pressure, and mass...