Sharif Digital Repository

Permanent Downhole Gauge (PDG) has been employed since 1990s to acquire more information and better access to well and control production. PDG provides huge amount of pressure transient data during well test operation and production. However, such data are encountering with various noise and outliers. The noise and outliers can cause misleading and misinterpretation results. Therefore, denoising and outlier removal are two imperative steps before pressure transient analysis. The conventional denoising methods are mostly based on wavelet thresholding methods that preserve mean of data and have good performance when noise distribution is Gaussian distribution. However, noise distribution... 

Underground reservoirs are highly complicated due to the presence of spatial heterogeneities at length scales that span from micrometer in pore structure of the rocks to kilometer in the reservoir models. While large-scale flow units need to be characterized using seismic and well data, detailed displacements of fluids in pore space need to be modeled using thin section analysis and pore network modeling. It is therefore necessary to adopt a multi-scale approach to reservoir description to make best use of all the available data that vary over several orders of magnitude, from micro-scale in pore structure to field scale in reservoir flow models. In this thesis, an integrated framework for... 

In this research, we focused on demonstration of features and advantages of supercritical fluids technology to formation of fine particles (nano and micro scales) from bulk materials (solid) and synthesized metal oxides nanoparticles. Therefore, using two different fluids, carbon dioxide and water, and two completely different methods, the Rapid expansion of supercritical solution and supercritical hydrothermal, were used to produce fine particles of drug (acetaminophen) and nano metal oxide (zirconium dioxide and bismuth ferrite). The summary of this research are as follows:1. The solubility of acetaminophen in SuperCritical-Carbon Dioxide (SC-CO2) with and without menthol as a cosolvent... 

Polyamide 6 (PA6) / Polyphenylene oxide (PPO) nanoblends containing carbon naotube (CNT)/conductive carbon black (CCB) with incorporation of PPO-g-MA compatibilizer, physical and chemical dispersing agents were prepared via melt blending method. The effect of carbonic nano additives weight percent, incorporation of physical dispersing agent, PA6 viscosity, PPO weight percent and sequential mixing were investigated. Modified CNT with physical dispersing agent studied by thermal gravimetric analysis (TGA), fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy and PPO-g-MA studied by FTIR and titration. Also, nanoblend morphologies, CNT/CCB dispersability and CNT/CCB selective... 

In this study the kinetic modeling of visbreaking reactions of heavy oils was investigated using available experimental data from the literatures. The continuous lumping model was developed for kinetic analysis of visbreaking reactions. The normalized boiling point was used to describe the reactant mixture as a continuous mixture and the concentration distribution of the mixture would change under reaction conditions. The continuous model with five adjustable parameters was used to describe visbreaking reactions and these parameters were optimized for each feed and reaction temperatures in the range of 400 to 430ºC using the available experimental data. Therefore for a special feed in a... 

The kinetics of side reactions in dehydrogenation of propane over a supported platinum catalyst modified by tin was investigated. Catalytic dehydrogenation over a commercial Pt-Sn/γ-Al2O3 was carried out in a laboratory-scale plug-flow reactor at 580 to 620oC under atmospheric pressure. Several kinetic models derived from different reaction mechanisms were tested using experimental data obtained over a range of reaction conditions. It was found that the kinetics of the main dehydrogenation reaction was best described in terms of a Langmuir-Hinshelwood mechanism where adsorption of propane was the rate controlling step. Simple power low rate expressions were used to express the kinetics of... 

The traders exchange currencies in an online foreign exchange market (Forex), so they need to know ways help them to predict trend of market. There are some methods to forecast exchange rate based on experiment. However they can submit good signals, they are too late for exchange. Two things are important, they should be correct and on time. In this research, we try to submit a prediction by Adaptive Methods in which provides both of them. In first approach, we test 468 models of Artificial Neural Network to achieve the best; and in second approach, Genetic Algorithm and Swarm Intelligence are applied to training Artificial Neural Network. Finally, in addition to forecasting exchange rate,... 

Government intervention in markets may go beyond the market regulation. Interventions may cause some idiosyncratic price distortions. It means the relative prices of factors to become different among firms. Therefore, micro conditions for firms will be changed. These will result in misallocation of factor production between firms and change in manufacturing TFP. According to data from about 14000 medium and small industrial firms in Iran, removing misallocation of production factors (capital and energy) and output idiosyncratic distortions between industrial firms would result in 115 percent increase in manufacturing TFP.

 

In this research a monopolist is considered which its object is maximization of profit during a predetermined period. Optimal control theory is used as a tool for determining of optimal trend for control variables. Price, warranty length and production rate are considered as control variables and cumulative demand and production are considered as state variables. Learning effect in production side and demand side are entered in the model too. In the demand side, learning effect shows its influences with movement of market from diffusion phase to saturation phase. In diffusion phase the demanded quantity of productions increases by increase of cumulative demand, on the contrary in the... 

In this research, a new metaheuristic algorithm is developed for solving the Discrete Time- Resource Trade off Problem in the field of project scheduling.In this problem ,a project contains activities interrelated by finish-start type precedence constraints and each has a specified work content and can be performed in different combinations of duration and resource requirement.Since the problem is NP-hard , the Particle Swarm Optimization is adopted due to minimization of the makespan subject to precedence relations and a single renewable resource. Basically PSO is used to solve continous problems and discrete problems have just begun to be solved by the discrete PSO.In proposed method,a... 

Nanotechnology requires a number of infrastructures for reaching its sustainable development. For each step of its development , various infrastructures should be studied and prepared in advance.In this direction, by introducing and recognizing the priority of Iran Nanotechnology R&D indexes ,the present research is going to propose an effective help. In this case, after studying the related literature and gathering the needed data , 27 indexes were recognized. Then , the indexes were divided in 7 criteria.In order to find the priority of the applied indexes , Fuzzy Multiple Criteria Decision Making (FMCDM) was applied. As the weighting of 7 criteria had been found by FANP , the... 

Propylene, as one of the most important raw materials of petrochemical industries, is produced through different methods. One of the major methods is propane dehydrogenation. This reaction is endothermic and many by-products will be produced in high temperature. Therefore catalytic dehydrogenation is preferred. Reduction in catalyst's activity and too many side reactions are the most important problems. Coke formation is the most effective reason of deactivation. Main source of coke is propylene. Experiments show that very small amount of water presence within reaction can reduce rate of coke formation. Water content growth does not always increase activity. If water be more than optimum...