Sharif Digital Repository

Possessing second place among gas reserve owner countries worldwide, Iran enjoys a very particular position in energy supply field. The crude oil is about to be replaced by natural gas in fuel sector because of growing demand for natural gas along with depletion of crude oil reserves. Some other drivers to this change are the increase in the known reserves of natural gas, the need to monetize stranded gas reserves and the environmental pressure to minimize the flaring of associated gas and carbon dioxide emissions. In such conditions the optimum consumption of these national abundant resources results in obtaining considerable revenues and strong presence of Iran in world consumption... 

The iron and steel industry has faced several challenges during the recent years. There has always been an aspiration towards higher economic profitability for the system. During the mid 1970s and 1980s the energy crises caused a dramatic rise in energy costs, which led to an increased awareness in energy conservation. In recent years, climate change issues have become more important for the industry. The operating practices for an industrial system are often affected by external restrictions concerning the economical, energy and environmental efficiency of the system. There are a large number of ways to increase the system efficiency, e.g. installation of new process equipment, and practice... 

Considering finish ability of fossil fuels and their polluting effects accordingly a need of renewable energies is felt. Among these clean energies biomass considering economical and environmental advantages is one of bests. Therefore a sufficient energy¬-¬efficient process with a good efficiency is needed. In this study an analysis of different mechanism to produce bioethanol from biomass has been done. According to the results from simulation the recovery step of bioethanol from the existing dilute solution from fermentation consumes the most energy in the process. Therefore substituting saline extractive column can result in saving energy. Finally in order to get more accurate result the... 

Analysis of energy flow which effectively leads to reducing energy consumption in buildings is of major importance. The following research is the development of methodology and simulation of energy in the residential buildings and realization of the methods by means of FORTRAN software. In the process of modeling energy flow, in order to evaluate thermal comfort and calculate building’s thermal load, the dynamic and integrated interaction of these parameters must be appraised. The continuous and integrated study required that Mass and energy flow, for various component of building, and their interaction be examined. These factors could not be assessed using simple and reliable methods. In... 

Wireless Sensor Networks (WSNs) has been a research topic for more than a decade, and the range of potential applications has spanned beyond the military domain into commercial domains. A key feature of current WSN solutions is operation in unlicensed frequency bands, for instance, the worldwide available 2.4 GHz band. However, the same band is shared by other wireless applications, such as Wi-Fi and Bluetooth, as well as other proprietary technologies. There is evidence that unlicensed spectrum is becoming overcrowded, to solve this problem, concept of cognitive radio has been introduced.
A main challenge for routing in cognitive radio wireless sensor networks is the collaboration... 

In the building, can be used variaty of Heating, Ventilating and Air conditioning systems. Among the items that affect to select the hvac system can be pointed to building thermal demand and system energy consumpsion. simulation of this systems is one of the ways that can compare hvac systems in the building. according to Iran needs for preparation of software for optimization of energy carriers consumption in building proportional with existing matrials and equipment in the country, in this research has been tried methodology and modeling of hvac systems in the way developed that producted software is capable simply and practical for engineers be operational in a residential unit. In realy... 

This report models the electricity supply network by means of the ESM software. In this model, the distribution company obtains its final users’ electricity demand from three sources: distributed generation plants owned by private sector, distributed generation plants owned by the distribution company and buying from electricity market (Over distribution network). According to the model, the optimum point of operating the network is a point with maximum profit, minimum waste and environmental effects. The optimum point of supply minimizes the network wastes to an optimum extent. In this model, the distribution company can supply the extra electricity to the electricity market, provided that... 

Prolonging the lifetime of wireless sensor networks (WSN) is one of the most important goals in the sensor network research. A lot of work has been done to achieve this goal. Since sensor nodes normally have limited resources in terms of energy, bandwidth and computation capability, efficiency is a key design goal in sensor network research. Data aggregation is a very important method to conserve energy by eliminating the inherent redundancy of raw data in dense WSNs. Previous research on data aggregation has demonstrated its effectiveness in reducing traffic, easing congestion and decreasing the energy consumption. However, few are actually designed for a real world application and... 

The problem of energy is one of the most important and challenging subjects in both science and engineering. However The problem is deeper and more vital in science. In order to prob the concept of energy, it seems nessesary to know the correct meaning of that. In addition to considering and investigating different definitions of energy and exploring its relation with other quantities – specially mass, the thesis plans to search and survey about its meaning. After vast study and complete analyze around this subject, we finish the text presenting a particular conclusion concerning concept of energy and its relation with matter that shows a some what clear image of it. The subject of energy,... 

According to the Government policy in order to make targeted subsidies and apply it on various sectors in the industrial, commercial, agricultural, household and etc. changes in the energy supply needed resources in this section are required to appear. The agriculture sector is one of the most important parts of the food production is the production of security and health product. In this regard, the production of greenhouse products in terms of the use of high yielding varieties, production of the off-season, better control factors in production and reduce water consumption has increased drastically. The main source of supply in the internal energy of the greenhouse heating is mainly fossil... 

Considering problems related to energy, including high fuel prices, increasing demand, constraints, and environmental pollution, makes it clear that efficiency is one of the major problems in all over the world. Iran’s southern parts and those countries around Persian Gulf face serious shortage of drinking water. Moreover, on top of the other three types of energy production the need for drinking water is highly sensible. Therefore, the use of CCHPW System is the best solution in these areas. The purpose of this design is to empower the control capability of the combined systems over all factors and apply the necessary changes under different conditions. This endeavor requires a program to... 

Environmental pollution and depleting the resources of energy are two significant crises which has been caused by excessive Energy consumption in all over the world. One of the most appropriate and reproducible energies is the Biogas energy. Huge amount of sewages and dry wastes are produced in cities every day can causes devastated damages to environment. All types organic matter extracted from different processes of treating sewages are influenced by germ activities and will be transformed to mineral structures and the final product of these reactions would be gases which can be used as enormous sources of fuel and energy. There are different devices made all over the world to be utilized... 

Iran has the third largest reservoirs of oil and the second largest reservoirs of gas and has the greatest hydrocarbon reservoirs worldwide. Considering the fact that production of oil is highly dependent on gas injection, Iran is facing a great challenge in determining proper strategy for consuming natural gas. Due to the lack of proper strategy form the point of view of economical as well as scientific evaluation in political and social aspects, it has resulted in weakening Iran’s place in international markets and also reduction of oil wells’ productions.In this study, after a review of relevant literature, characteristics of oil and gas projects effective on modeling them were... 

Regarding the notable progress in communication and competition theories as well as natural sciences, the study of the concepts of information has displayed more attention in recent years.Information, entropy and energy are interrelated concepts. In one hand one can infer that entropy is a quantitation measure of information and on the other hand systems which carry information can accumulated energy.Here, we are going to survey the qualitation as well as quantitation aspects of information with concentration on the behavior of chemical agents as information processors  

This thesis represents a comprehensive view of electric vehicles from the macroeconomic policy in the energy sector perspective. In fact, in this thesis all the efficient factors in the presence of electric vehicles in the transport sector have been completely proceed. Environmental, economic, social and political factors, power grids and infrastructure are considered as the impressive factors. In order to check all factors comprehensively, Systems thinking based on dynamic system method is used. The causal relationships between all the variables which are involved in the presence of electric vehicles and related models to this thesis are simulated in VENSIM software. To investigate this... 

Dynamic Random Access Memory (DRAM) has been the leading main memory technology during the last four decades. In deep sub-micron regime, however, scaling DRAM comes with several challenges caused by charge leakage and imprecise charge placement. Phase Change Memory (PCM) technology is known as one of the most promising technologies to replace DRAM. Compared to competitive non-volatile memories, PCM benefits from best attributes of fast random access, negligible leakage energy, superior scalability, high density, and operating in both Single-level Cell (SLC) and Multi-level Cell (MLC) storage levels without imposing large storage overhead. Unfortunately, density advantage of MLC PCM devices... 

Appearance of CUDA architecture results in GPU introduction as a suitable platform for parallel processing. Massive usage of GPGPUs in various applications forces the manufacturers to produce this processor with different configurations based on their application demands. But always the design approach observes a ratio between processing capability and bandwidth of GPGPUs. In this way mostly in all GPGPU series the bandwidth increases with growth of GPGPU processing power. At first glance this ratio seems reasonable because more process needs more data. However this approach does not pay attention to the behavior of a wide range of workloads which do not need such a bandwidth. Mentioned... 

Both resources have shaped the development of societies during the course of history. The increase in population, the growthe of middle-class societies, climate changes, economic development, health and environmental concerns, all play roles in magnifying or reducing the growing stresses on the vital resources of water and energy. Projections for water availability and quality, food and enrgy availability, soil and air quality are alarming. These alarms point to a major conclusion:’business as usual’ is no longer viable. Indeed, they call for a fundamental shift in the manner in which we understand and manage resources: a shift away from traditional approaches toward more integrative,... 

Nowadays, water and energy shortage is the main concern of many industries. Every saving that could be done is valuable. In the first step of this project, energy recovery devices that are used in reverse osmosis systems, are reviewed and advantages and disadvantages of each system are investigated. These apparatuses save energy by recovering high-pressure energy from leaving brine and reduce the energy consumption of the device. The main focus of this study is energy consumption of the device that is used for desalination of seawater in reverse osmosis systems and on this basis, different energy recovery devices are compared. According to the investigation, results showed that most of the... 

Today, energy has a great impact on the economy, political relations, prosperity, and lifestyle of human societies. Energy sustainable development has become inevitable because of factors such as increasing population growth and as a result, increasing the energy consumption, consuming more energy from fossil fuels, decreasing in reserves of fossil fuel resources, environmental damage caused by the burning down of fossil fuels and greenhouse gas emissions,high cost of energy from burning fossil fuels.Generally, the sustainable development isall steps in order to comply with economic development and protecting the environment, resources and living standards. Considering that a large part of...