Sharif Digital Repository

Nowadays, we know that many hydrocarbon reservoirs are fractured regarding this, the investigation of the properties of these reservoirs is necessary to predict the storage, production and the drilling methods. To identify fractured reservoirs, the fracture properties and their geometries under different conditions should be investigated. Besides, the evaluation of the behavior of induced fractures in distinct under ground conditions is very important. The Mechanical properties of the drilling bed like crack propagation, layer and mass rock is impactful in planning of drilling process and hydraulic fracturing operation. In this research, at first we introduce natural and induced fractures... 

As producing and consuming of natural gas has increased in recent years, improving natural gas distribution and transfer network systems has become vital. Pressure reduction station (PRS) is an important part of the natural gas network. Common PRSs are facing two issues: first is the pressure reduction technology, which is throttling valve that destroys the exergy of the high pressure flow. The solution is to utilize turbo-expander instead which can recover the energy. Second is the preheating technology which is boiler and water bath heater in the common systems that cause environmental problems. Using solar collectors is one of the best solution based on the literature. Since the solar... 

Globally energy system is the main source of green house gas emission. 60-90 percent of manmade CO2 is due to energy sector. Pollutants like NOx, CO, Non Methane Hydrocarbons which may cause indirect effect on climate system are mainly emitting from energy sector. Gas, Oil and Coal extraction and transmission are responsible for more than 15% of Methane emission globally. Therefore it is important to consider all types of GHGs emission as well as all sectors of energy system to assess the GHGs mitigation potential throughout the energy system. Considering the significance of energy sector in GHGs emission, in this study we developed an optimized model for Iran’s energy sector in which we ran... 

The image-based profile is a technology by which image morphology information is transformed into a multidimensional profile from a set of image-derived features. These profiles can be used to extract biologically meaningful biological information. For example, in the drug discovery process, the mechanism of action of a drug or disease can be identified by examining the morphological properties of the drug in the patient’s cell or tissue and used to design new drugs or use existing drugs for various diseases. High-throughput imaging technology allows the imaging of a large number of different experiments. Extracting valuable features and a good representation of features is the main... 

Nowadays, the capital market has a significant impact on the economy of a country and causes economic dynamism and growth in gross production. Among the important phenomena in the stock market is stock pricing, the correctness or incorrectness of which has a significant role in the performance of the stock market and the value of companies. The stock price in the stock exchange represents the stock market value and usually represents the investment value of the shareholders. Forecasting the trend of the stock market is considered an important and necessary thing and has been given much attention, because the successful forecasting of the stock price may lead to attractive profits by making... 

Numerical three-dimensional simulation of the entire regions of a gas turbine blade, including hot gas flow over the blade surface, conduction heat transfer within the blade metal, and coolant flow through the Internal cooling System, is highly time-consuming and expensive. Therefore, one-dimensional internal flow simulation is one of the main objectives of this research to address the limitations of commercial software in predicting the temperature distribution along the cooling path. In this study, a one-dimensional in-house simulation code is developed to simulate the coolant flow inside the cooling channels of the internal cooling system of the blade. Additionally, using artificial... 

In this study, Lithium recovery process from lithium-ion battery was investigated by electrodialysis method. First, the cathode of the battery was leached in NMP to separate cathode from aluminum foil. Then, the cathode was leached in sulfuric acid with concentration 3.25 M and 10 volume percent hydrogen peroxide that pulp density was 55 g/L at 60°C for 100 minutes. in the next step, an electrodialysis cell was designed and created to recover lithium. And the influence of time, voltage, flow rate of feed solution, concentration of electrode solution and concentration of feed solution on process was investigated. Purpose of this project were investigated lithium ion recovery rate, lithium... 

Graph signals are sets of values residing on sets of nodes that are connected via edges. Graph Neural Networks (GNNs) are a type of machine learning model for working with graph-structured data, such as graph signals. GNNs have applications in graph classification, node classification, and link prediction. They can be thought of as learnable filters. In this thesis, our focus is on graph filters and enhancing the performance of GNNs. In the first part, we aim to reduce computational costs in graph signal processing, particularly in graph filters. We explore methods to transform signals to the frequency domain with lower computational cost. In the latter part, we examine regulations in... 

Recent advancements in polymer science highlight the growing interest in enhancing polymeric materials with nanoparticles. These materials have extensive applications in tissue engineering, food packaging, and drug delivery due to their biodegradability, sustainable sourcing, and comparable properties to petroleum-based polymers.This study explores composites of polylactic acid, polyethylene glycol, and nanocrystalline cellulose for controlled ciprofloxacin release. Antibacterial activity was assessed through inhibition zone measurements, and cytotoxicity was evaluated using cell viability assays. Results demonstrated a direct correlation between drug release and antibacterial efficacy. Drug... 

The construction industry is undergoing a profound transformation driven by technological advancements, with Building Information Modeling (BIM) at the center of this change. BIM is not merely a tool but a comprehensive process that enhances the design, management, and execution of construction projects by integrating advanced digital technologies. Globally, BIM has proven its ability to address complex project challenges, optimize stakeholder collaboration, reduce costs, and improve efficiency. However, BIM adoption in Iran, particularly among construction product manufacturers, remains limited. While other stakeholders have gradually embraced this technology, this limitation has hindered... 

The ever-increasing applications of fluids in residential areas as well as in main industries require investment to advance and optimize fluid control and their real-time flow rate monitoring. Numerous methods have been developed for measuring fluid flow rates, particularly for water. This study focuses on the design and evaluation of a sound-based water flow measurement system. As the first test, a microphone was placed on the water pipe, and through time-domain analysis, a second-degree relationship was found between the pressure amplitude of the signal and the flow rate to increase the accuracy of signal processing. Analysis of the signal-to-noise ratio revealed that the vibration of the... 

This research examines the impact of indirect network effects in platforms on the likelihood of success for platform complements. The main question addressed by this study is: How does a larger number of complements in a platform ecosystem, through access to diverse resources and knowledge, influence the enhancement of innovation and the likelihood of success for platform complements? While the expansion of indirect networks creates more opportunities for innovation and access to resources on one hand, it may also lead to negative effects such as increased competition among complements and user confusion on the other. The goal of this research is to provide a comprehensive answer to these... 

With the increase in population, industrial advancements, and urbanization, the demand for clean water resources has risen. However, industrial pollutants, particularly heavy metals, pose a significant threat to aquatic ecosystems, necessitating their removal from wastewater. Among various methods, surface adsorption using hydrogels has proven to be effective. This research aims to develop hydrogels from sodium alginate and carboxymethyl nanocellulose for the adsorption of heavy metals, specifically copper and nickel, from wastewater. The results indicate that increasing the percentage of nanocrystalline cellulose enhances the hydrogel's swelling rate, while higher alginate content... 

The notable share of housing sector in GDP (approximately five percent) shows this sector’s relation with macroeconomic activities. On the other hand, House as an asset leads housing sector to be affected by monetary and fiscal variables. A dynamic panel data was used in this study to evaluate the relations between housing sector and some macroeconomic variables in metropolises of Iran. As results show, in long term growth of liquidity, GDP per capita and sharp ratio have positive effects, and land per capita has negative effect on housing price in metropolises of Iran. Price increases have not been equal in different cities. Inequality of land price between metropolises and between... 

In this research, an Index of Iran informal economy in response to the government interventions in credit, labor and product markets is stimated by EMIMIC model. To do this, first these interventions are measured using principal components analysis. In the model, the variables GDP and employment are used as indicators and taxation rates, government distortions in credit, labor and product markets, government expenditure, per capita income, unemployment and inflation as causes of the informal economy. We conclude these government interventions have affected Iran informal economy and their influence is more than indirect interventions influence such as taxation. The estimated index of Iran... 

With altering natural state and increasing impervious surfaces, traditional urbanization leads to deteriorating the environment and water catchments. During the years most efforts in order to control the urban runoff outflow, have been focused on quantity; and awareness about improving water quality has been raised just in the last few years and, which emphasizes on pollution source control. Standard water quality sampling methods are time consuming, expensive and because of sampling in broad geographic areas, difficult; however modeling is a more efficient way in assessing water quality and as worries about non-point source pollution grows, different kinds of models have been used to...