Sharif Digital Repository

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... 

Use of nano-scale VLSI technologies in the fabrication of System-on-Chips (SoCs) makes reliability as one of the major issues in the design and implementation of these products. SoCs are susceptible to several fault sources such as crosstalks, cosmic particle strikes, electromagnetic interferences, and power supply disturbances. Among the mentioned fault sources, crosstalks have the major contribution in threatening the reliability of SoCs. This thesis addresses the modeling and mitigation of crosstalk faults. In this regard, two analytical models and three crosstalk reduction methods have been introduced. The proposed analytical models, which have been introduced in the fourth chapter of... 

Climate change and energy security are key drivers for future energy policy. While energy security has been a pillar of energy policy for about a century, concern about climate change is more recent and is bound to radically change the landscape of energy policy. Policy makers are now under increasing pressure to address these twin challenges: to develop cost-effective policies that will both ensure the security of our energy system and reduce greenhouse gas emissions.
Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in... 

Based on International Energy Agency studies, achievement of 450 ppm CO2-equivalent emission target in global emission means that the CO2 emissions in 2050 must be reduced to %50 of 2005 level, and this implies that a portfolio of emission reduction policies and strategies need to be exploited through current century.
At the present time, Carbon Capture and Storage (CCS) Technology is a dominant strategy among all the long-term carbon abatement strategies in many countries. Nevertheless, its potential as a climate mitigating option will be proved, only if it is implemented in the countries which are developing at a great pace and taking advantage of fossil fuels in order to afford their... 

Release of toxic gases and hazardous materials is very dangerous for health of people that presence in near of release places. Whereas if the concentration of some toxic materials is more than a definite limit, it may cause of irreparable hurt to health of people in very short times, hence reduce the concentration of released materials can get the time for refuge in safe sites for people that presence in released site in initial times.
In this paper with use the Computational Fluid Dynamics models the effect of fence in reduce the concentration of dense gases and delay the distribution of these gases has been studied. The two toxic gas (chlorine and methyl-isocyanate ) have been... 

Evaporative cooling systems are of most common cooling systems which their electricity consumption is much lower than vapor compression cooling systems. Enhancement of these system’s performance could help to propagate these systems and also decrease the electricity consumption and corresponding emissions in large scale. In this thesis, first a modified cycle is proposed for evaporative cooling. Then, in order to use evaporative cooling in humid climates, a desiccant wheel is implemented in this modified evaporative cooler. As using evaporative cooling will cause high water consumption, a novel cycle is proposed for desiccant based evaporative cooling which is able to cover system water... 

The main goal of partake quake-attenuating in buildings is to absorb energy and to attenuate the exerted forces into structures as a result of ground motions. Notwithstanding achievements and developments in the field of dampers production, applying of dampers in structures is proportional to following complicated technology and subtle engineering. Installation and initiation of dampers depend on educated and expert crew; moreover, such attenuating systems need maintenance and repair during the useful structural life time. Therefore, nowadays civil engineering suffers from the lack of such quake-attenuating systems to be able to respond simply but applicable mechanism at the same time for... 

Oil and gas industries are always considered as one of the most polluting industries in the world. Many pollutants are emitted from the industry into the environment every year. Equipment’s leak and flaring off additional gases produced by various processes of oil and gas production are the main sources of waste in these industries. In order to control these hazardous wastes, it is necessary to provide effective solutions and make appropriate decisions so policymakers will be able to implement policies in order to reduce the emissions of air pollutants. In order to reduce the emissions, it is necessary to conduct the correct and reliable methods and have sufficient information about the... 

Carbon dioxide is one of the main geenhouse gases emitted from factories as well as transportation vehicles that adversely affect the atmosphere and cause global warming. Among the proposed solutions to reduce carbon dioxide in the atmosphere, carbon dioxide separation would be the most viable medium-term approach. However, the high cost of carbon dioxide separation prevents the development of carbon dioxide absorption technologies. Therefore, it seems that integrating separation and production processes is the most efficient way to save energy and reduce carbon emissions. This method decrease a high proportion of the energy consumption in upstream operations (carbon dioxide removal,... 

Today, considering the global demand for reducing greenhouse gas emissions, rechargeable batteries are considered as a source of energy in electric vehicles, hybrid electric vehicles and smart grids. In all these applications for secondary batteries, the battery management system requires an accurate estimate state of charge of each cell. However, this estimate is difficult particularly for battery aging. In this study, a lithium-ion battery is modeled by using multidimensional multiphysics modeling and simulated in a comsol. In this simulation, the effect of the thermal conductivity coefficient on the battery temperature, initial salt concentration in electrolyte and the rate of discharge... 

The release of toxic materials causes tragic accidents every year. There are various techniques in order to mitigate the release effect of these materials such as Application of air jets, steam curtains and water curtains. This study presents numerical calculations to reproduce the continuous ammonia release dispersion with and without the mitigating influence of a downwind water curtain using computational fluid dynamic (CFD) software ANSYS Fluent 15.0. The RNG model coupled with Lagrangian discrete phase model (DPM) was used to simulate the dilution effectiveness of the water curtain system. The ammonia absorption was taken into account by means of user-defined functions (UDF). The... 

Scientific studies, conducted over the world, show that an immense portion of pollutants and greenhouse gases emission to the atmosphere are the direct result of the incineration of fossil fuels in industrial units. These industrial units include chemical industries, power plants, metal industry, etc. Therefore, there is a tremendous necessity to reduce the pollutants emission from these industries immediately and effectively. Meanwhile, in order to mitigate the emission to the atmosphere, there should be a meticulous estimation of pollutants emission from various sources. Hence, in a project called "standardization of emission of pollutants from diverse industrial units in Iran", the... 

Controlling, managing, and mitigating the emission of greenhouse gases, especially carbon dioxide, which are produced by human activities, are one of the main concerns of researchers today. Market-based methods are one the successful methods to enhance controlling, managing, and mitigating carbon dioxide emissions, among which the carbon tax has received more attention. Increasing clean technologies in the electricity network to the reduce the emissions of the electricity industry may reduce the carbon tax rate. In this regard, the life cycle analysis makes it possible to consider the emissions of the life cycle. The present model is applied for two representative days of Iran's electricity... 

The transportation and electricity industries are major emitters of greenhouse gases (GHGs). In order to reduce emissions, several strategies have been proposed, including plug-in electric vehicle (PEV) use and integration of renewable energy sources (RESs). To reduce the concern emission rate while considering economic constraints, it is important to examine different scenarios of incorporating these elements. To investigate the effectiveness of using PEVs and RES from various perspectives, this study utilizes a combined economic emission dispatch (CEED). The influence of emission and cost coefficients is examined in a sensitivity analysis. In the proposed model, two test cases containing... 

CO2 capture and utilization (CCU) is a promising approach to reduce and control emissions from the industry and energy sector, while also creating new jobs and value-added products. However, one of the main barriers to the widespread adoption of CCU is the high investment and operating costs, which limit its implementation to mostly government-supported research projects. To overcome this barrier, structural optimization and identification of optimal routes and formation of industrial symbiosis networks are needed. In this research, we developed a comprehensive superstructure that includes sources and sinks (in a case study), CO2 capture and separation material and technology combinations... 

In this research, a multigeneration system was designed and evaluated, utilizing solar and geothermal energy to generate electricity, fresh water, hydrogen, and oxygen. The system's performance was assessed from energy, exergy, and economic perspectives. The setup involves a solar tower contributing energy to the gas cycle and a geothermal well supplying preheated water for the steam cycle. The system employs a molten salt cycle to capture heat from the solar receiver, transferring it to the air cycle. The remaining energy requirement is met by the Air Brayton cycle, which combines methane and hydrogen as fuels within the combustion chamber. Additionally, a steam cycle is integrated to...