Sharif Digital Repository

Improper management and inefficient methods such as direct disposal to the environment to stabilize municipal solid waste and sewage sludge in addition to creating environmental problems due to the existence of food cycles, will also cause problems on human health. In this study, a hybrid system is modeled to produce value added in the form of energy and nutrients from a combination of food waste and secondary sewage sludge. This system has 3 subsystems, two-stage anaerobic digestion process that will be accompanied by the production of your bios (hydrogen + methane), the process of recovery of phosphorus from the sludge out of the digestion process and the system of simultaneous production... 

One of the most modern types of inlets in aircraft is the Diverterless supersonic inlet, which is used in some new UAVs and fighters, and has many advantages over other types of inlets, especially in removing the boundary layer. The most important part of DSI design is the creation of bump geometry, which requires special precision and elegance. There are various methods for designing and creating bump geometry, some of which are mentioned in this report, and finally the method of creating bump geometry is selected based on the flow around the primary cone, which is in accordance with the analytical method and is in fact the most basic and widely used method.In this study, a DSI with cowl... 

Most used polymers, such as hydrolyzed polyacrylamide, are not able to withstand high levels of salinity and high temperature of the reservoirs. To overcome these problems, in this project, new types of microstructures based on modified acrylamide with hydrophilic groups (malic anhydride monomer) and hydrophobic groups (styrene monomer) using inversible mini-emulsion were synthesized. The structure of the synthesized terpolymer was investigated using methods of FT-IR and 1H NMR. The micro-structure and the particle-size of the terpolymer particles were studied with the scanning electron microscopy (FE-SEM) and differential light scattering (DLS) method and the results showed that the average... 

Increasing the global demand for energy and decreasing the production rate of oil reservoirs have forced the oil companies to focus on enhanced oil recovery (EOR) extensively. This paper summarizes the design, reservoir simulation, and results of different gas injection scenarios in one of the Iranian complex oil reservoirs. This complex reservoir is located in the south west of Iran and is made up of sandstone, limestone, and dolomite layers. It is an under saturated reservoir with no gas cap but with a strong aquifer. Oil production has started in 1977, but due to strong aquifer the production is still in the plateau period. In this study, by simulation, it is estimated that natural... 

Concrete is the second most structural material in the world. So attention and promotion of the concrete mix design with respect to variable issues and requirements, is very important. On the other hand, these days environment and its pollution has become very popular discussion. Waste-glass which is produced by human products is one of the environmental pollutants. In this thesis it replaces some aggregate in concrete and it can reduce the level of this material in the world. Also we study effects of silica-fume as cement replacement and properties enhancer in our concrete mix design and see how it can ... 

Low salinity water flooding (LSWF) as an efficient enhanced oil recovery (EOR) technique is proved to affect both, fluid-fluid and rock-fluid interactions to potentially release the trapped oil from the porous rock. Despite more than one decade of extensive research works on the low salinity water effect (LSWE), there are still many parameters to be studied for very complex cases. Therefore, in the first part of the experimental study of the dissertation, a systematic investigation on the effect of the initial wetting state (water-wet or oil-wet) of pure calcite is conducted to study the importance of fluid/fluid and fluid/rock interactions for LSWE investigation. In the case of initially... 

Compressor stations with gas turbine drive have become common in transport of natural gas. However, the thermal efficiency of the gas turbines used in these stations is low. One reason for this is that 70% of the heat of combustion of the fuel gas used by the gas turbine is lost with its exhaust gases. Hence, heat recovery from gas turbine exhaust gas would increase the cycle efficiency by decreasing the fuel gas consumed. On the other hand, gas turbine efficiency highly depends on the climatic conditions of operation. Among several well known methods of performance improvement, the use of an absorption chiller for inlet air cooling has been studied from both process and economic points of... 

EOR (oil enhanced recovery) is very important as oil is a nonrenewable resource. Depending on the characteristics of the rock formation, primary production can result in the recovery of up to 20% of the oil originally in the rock. This means that at least 80% of the oil may remain in the rock unless additional technology is used to increase the recovery. Before finding best way to do for EOR, scientists must study properties of different porous media that oil is trapped between its grains. Most of research and studies investigate networks of porous media but this work focused on oil movement through a pore space in porous media lonely not in network by waterflooding. Studying a pore space is... 

In this thesis, scheduling of surgery rooms is investigated and the objective is minimizing total patient’s departure time from the ward room in a flexible flow shop manner. Here, some constraints like the capacity of recovery rooms, no-wait motion between the rooms and machine eligibility restrictions ( , Σ ) are considered.For solving this problem,we proposed two mixed integer linear programming models for the research problem. Since the research problem is shown to be NP-complete, we developed several algorithm based on Tabu Search (TS) to heuristically solve it. In TS algorithm two different methods and one neighborhood structures are applied to generate initial solution and... 

Minimum miscibility pressure (MMP) is a key parameter for successful gas injection process in the oil reservoirs for more oil recovery. This parameter is critically dependent on the reservoir condition such as temperature, reservoir and injection gas composition. There are many techniques used in the literature for MMP measurement. Vanishing interfacial tension (VIT) has been proposed recently and was used successfully to predict the MMP through pendant drop technique. This technique is used in this study to measure the MMP for Nitrogen/Carbon dioxide and water in oil emulsion fluids; then compare it to the original crude oil without water droplets. This would demonstrate the effects of... 

In this research copper oxide ores were dissolved under acidic condition. Chemical analysis (XRF) and X-Ray diffraction analysis (XRD) were used to identify the phases and determine the percentage and amount of the elements in the mineral. The results showed that the mineral contains 4.464% by weight of copper, which is malachite in mineral. The experimental design method (DOE) was used to dissolve concentrate by sulfurice acid. The parameters of temperature, time, acid concentration and solid to liquid ratio, as well as the interaction of these parameters on leaching and optimization of parameters were also done by response surface method (RSM). To determine the amount of copper dissolved,... 

Monitoring large-scale networks is a critical yet challenging task. Enormous number of nodes and links, limited power, and lack of direct acceß to the entire network,are the most important difficulties. In applications such as network routing,where all nodes need to monitor the status of the entire network, the situation is even worse. In this thesis, a collaborative model in which nodes pick up information from measurements generated by other nodes, is proposed. Considering the fact that in most cases the networked data is sufficiently sparse, we used the Compreßive Sensing theory in the recovery phase of the proposed method. Using this model, for the first time, an upper bound is derived... 

The continuous growth of network traffic and people's demand for higher data rates, have driven wireline communication systems towards higher data rates. In these systems, the power consumption of these transmitters and receivers is a crucial and influential factor. This paper presents two different solutions to reduce the power consumption and area of these systems. In the first solution, a low-power phase shifter with variable phase and amplitude control is introduced. The changes in these parameters are mutually orthogonal, ensuring that a change in one characteristic does not affect the others. This phase shifter can be used to generate clock pulses with different phases in wireline... 

Nowadays, customers hold a pivotal role as co-creators of value in service industries. Therefore, companies usually try to encourage customers to interact and co-create value effectively with the company or with each other. However, if a service provider fails to meet customer expectations, service failure occurs and may influence customer evaluations to co-create value. In this situation, companies usually try to redress the problem that happened to reduce their negative perceptions. Research related to the drivers of customers' value co-creation intentions has gained interest in recent years. However, there has not been an integrated view to simultaneously examine the negative role of... 

Nowadays, customers hold a pivotal role as co-creators of value in service industries. Therefore, companies usually try to encourage customers to interact and co-create value effectively with the company or with each other. However, if a service provider fails to meet customer expectations, service failure occurs and may influence customer evaluations to co-create value. In this situation, companies usually try to redress the problem that happened to reduce their negative perceptions. Research related to the drivers of customers' value co-creation intentions has gained interest in recent years. However, there has not been an integrated view to simultaneously examine the negative role of... 

Acidizing is the most widely performed job to remove the formation damage, and enhance the oil recovery. Different models have been introduced to design the optimized condition for acidizing. However, none of them are able to predict the optimum injection flow rate in the actual application. As a result, Calcite cores are extracted from reservoirs for conducting experiments and modifying the present models. Nevertheless, acidizing is an intrusive technique destroying the costly extracted cores. Thus, there is a need to construct calcite cores of various porosities and permeabilities to take advantage of them in acidizing modelling.Microbially induced calcite precipitation is a well-known... 

Heavy oil reservoirs are becoming more important as the oil price increase and more light oil reservoirs are being depleted. Thermal oil recovery, especially steam flooding is considered as the most efficient EOR technique for heavy oil reservoirs that stays on the top of the recent EOR field experiences. However this method is not applicable in some reservoir conditions like deep reservoirs or reservoirs with thin pay zones.
Due to sever viscous fingering during water flooding heavy oil reservoirs, a large amount of oil would remain untouched in the reservoir. Polymer flooding could be a potential method for enhanced oil recovery by improving sweep efficiency. However there haven’t been... 

Availability of video recording instruments and ease of working with video editing tools have made contents of this digital signal unreliable in general. The goal of this thesis is to present a method to detect tampering of compressed videos in H.264/AVC format and restoring an approximate version of its original contents using watermarking. In the proposed scheme, a low resolution image from a number of video frames in certain time slots are embedded into the DCT coefficients of the other parts of the video which are adequately far from the reference frames. For detecting temporal and spatial tampering, the index of each frame and macroblock is embedded into itself as an authentication... 

With rising oil prices and predictions about the future of hydrocarbon reserves, issues of enhanced oil recovery and optimal production of existing reservoirs are of particular importance. In this study, molecular dynamics simulation was used to study the absorption of silica nanoparticles with surface groups at the interface of water and decane. The effect of surface chemistry of silica nanoparticles on the interface properties of water-decane with changing the surface groups was simulated. The initial surface factor of nanoparticle is hydroxyl (OH), which is called a hydrophilic surface agent. Nanoparticles were modified by methyl and ethyl surface agents to increase the hydrophobicity and... 

Gas pollutants are included volatile inorganic compositions and odorous materials, which are harmful and dangerous for environment and human health. There are several methods for removing gas pollutants such as physical, chemical and biological methods. In this work, we discuss about ethyl-mercaptan adsorption in LPG by ZSM-5 zeolite and in use of micro systems (micro channels). This work is also concerned about micro channel coating by ZSM-5 and NaY zeolites on glass and the method of coating with (3-Chloropropyl) trimethoxysilane linker. After selecting the appropriate method for zeolite coating, we proceed to micro channel coating. In this research, four different designs of micro channel...