Sharif Digital Repository

New electric Unmanned Aerial Vehicles (UAV) has unconventional methods for design and performance analyzing. Using the electric power sources and reduce power with time, cause to confusion about operating this type of planes, so new optimization methods are generated. This methods, can used for some part of flight and special problems and involve some assumptions. One of these new methods is using Singular Perturbation theory for prediction optimal path trajectory of Aerial Vehicles. In this research, we solve the optimal climb trajectory for an electric UAV in rested (no wind) atmosphere. Solution of this problem, involve some parameters such as velocity, altitude and flight path angle with... 

In recent years, access to clean energy sources is the major instruments for sustainable development. Limitation of energy resources and the problems resulting from the use of fossil fuels was caused attention to biomass in different countries as a stable source of renewable energy. Organic waste in municipal solid waste and domestic wastewater are biomasses that can be used as a raw material used in the production of energy. Practical studies show that quality and quantity of municipal solid waste to produce biogas and bioethanol in Iran is very appropriate. In this process, the household solid waste and wastewater are in the anaerobic digestion reactors and fermentation systems without any... 

Population growth require increasing demand of Energy. The fossil fuels are the main source of energy. However, they are main source of carbon dioxide emissions. Considerable amount of fossil fuels is used in the power plants. Increasing trend of electricity consumption as well as the lack of alternative fuels such as renewables in the short time will increase the consumption of fossil fuels and emissions. The most important greenhouse gas emitted from the power plants is carbon dioxide. That's why the separation of carbon dioxide from the gas stream of power plants is necessary.Separation of the carbon dioxide by adsorption is considered in this project both experimentally and... 

Energy consumption and pollutions especially carbon dioxide emissions are two of the main challenges in the cement industry. 5-7 percent of world’s carbon dioxide emissions is due to cement production while 900 kg of carbon dioxide is emitted for the production of a tone of cement. The main source of carbon dioxide emissions in a cement plant is the combustion of fuel to provide heating demands and also converting the ore into clinker. Therefore, any improvement in energy efficiency in a cement plant could reduce carbon dioxide emissions resulting from the combustion. Important ways of energy recovery in a cement plant are using the energy recovered from the exhaust gas in the preheater... 

Nowdays much of the organic solid waste and wastewater is buried using centralized and traditional methods. This leads to many problems, including groundwater pollution, methane emissions into the atmosphere and rapid transmission of disease. In order to avoid these problems, using a decentralized approach can be a good solution. In this study, recovery of organic waste and wastewater of residential buildings using anaerobic digester as a decentralized way, have been examined. Using experiments, the optimum mass ratio of organic solid waste and wastewater is obtained as 80% and 20% respectively. Biogas production model is developed using mass balance and Balance of electrons in redox... 

Nowadays, classic energy supply systems are rapidly shifting towards more efficient, with less pollution, and more economic energy systems. In the meantime, the growing dependence of human activities on energy sources and the reduction of fossil fuels resources as the main source of energy supply at present time, has led to fundamental changes in the energy policy of communities. The use of distributed power generation systems utilizing renewable energy sources is one of the solutions that have been proposed in this regard. This research aims to develop a local energy supply network for a specific rural district using energy sources in place, so that the area is energy self-sufficient and... 

Iran has many fossil fuels resources and today due to several reasons such as the environmental effects caused by burning these fuels, the depletion of fossil resources and energy security, the pattern of fuel production and consumption has changed.In recent years biofuels received the attention of researchers all over the world due to the sustainability of energy supply and their positive environmental effects. The agricultural wastes and Residues may be used to produce biofuels. Qazvin province, with its high potential of agriculture, can provide many sources of agricultural waste and residues for the production of biofuels. In this research, the aim is to optimize the biofuels supply... 

Due to the increase in population and the migration of people from rural to urban areas, the amount of municipal solid waste is increasing. Therefore, waste management is one of the most important social, economic, and even cultural issues in society now. In this research, one of the methods of waste management, i.e. energy production from waste based on municipal solid waste incinerators, will be investigated. Considering the sensitive environment of Mazandaran province, this province was chosen as the study area of the research. In the methodology of this research, after pre-processing the waste data of the case study, these data were determined as input conditions to the... 

The growing amounts of generation of electronic wastes (e-waste) and their increasing environmental impacts require a special optimal waste management strategy. Many different methods have been developed to managing e-waste. To make the best choices according to the conditions of each system, having an adequate knowledge of all methods and comparing them is the most important point. This research aims to design a system for managing e-waste by selecting mobile phones as an example of electronic waste and find the optimal condition of the system to increase economic benefits and reduce environmental impact. Recycling and landfill are selected as the main methods in this project. Four lines... 

There are different technologies for supplying water from alternative sources that meet different needs. In relation to thermal technologies such as multi-effect distillation, the highest water quality is obtained, there is no limit on the concentration of the incoming water, and there is the least need for maintenance. On the other hand, thermal technologies consume higher energy than membrane technologies. In this process, the better the heat transfer, the number of steps can be increased, and this means the production of more distilled water for the same amount of thermal energy. The distilled water layer on the surface of the heat exchanger has a high thermal resistance compared to the... 

Water and energy are among the sectors affected by climate change. In recent years, many effects of climate change have been observed. In 2021, average land and ocean temperatures are 0.84 degrees Celsius higher than the 20th century average. The impact of climate change on water resources is also reflected. Iran has dry and semi-arid climate and 41% of Iranians live in low water areas. Considering the population growth, industrial development and importance of agriculture in Qazvin, it is necessary to plan the management of the water sector in this area. In this project, a water supply network model is proposed to provide water between urban, industrial and agricultural consumers and... 

Preserving and promoting the health of citizens in a society is one of the most important problems addressed in any country. The power sector discharges a huge volume of carbon dioxide which intensifies the climate change and consequent human health problems.The goal of this study is to evaluate the ultimate effect of climate change caused by power plant emissions on the human health using life cycle analysis approach for different provinces in Iran. An integrated model has been developed to evaluate the impact of climate change due to power plant emissions on the human health. This model includes the equations regarding the variations in carbon dioxide concentration in the atmosphere,... 

Fossil fuel usage caused global warming and other environmental problems. Recently, biofuels are considered as an important alternative. However, the efficient usage of water and energy in their production may accelerate their diffusion. ETBE is a kind of oxidizing fuel additive that can be biologically produced from the ethanol reaction. High water and energy consumption in the production and separation process is still a challenge. In this work, the ETBE production from lignocellulosic feed are considered. Then, the effect of different parameters are investigated by performing sensitivity analysis. In the next step, the optimal pathway of water and energy use in the production of ETBE are... 

With the growing development of urban communities and population, the demand for water and treated sewage water has grown significantly. The environmental damage of polluted water has resulted in passing of new and strict environmental laws on wastewater discharge recently. In the present research, a hybrid system involving a power, heat and cool cogeneration and a carbon dioxide capture system has been designed for a typical wastewater treatment plant. The plant is optimized from economic and environmental criteria. The anaerobic digester is modeled using the ADM1 model. The biogas is directed into the hydrogen sulfide removal filter to remove the impurities and into the heat exchanger to... 

In recent years, there has been the extensive researches on energy and water efficiency due to the increasing stress on these resources. Therefore, the water-energy nexus in large industries, especially power plants, has become very important. In the present study, the water and energy nexus has been analyzed using energy analysis tools, exergy, economic and environmental in a combined cycle power plant. The nexus are observed in the boiler blow-downs, leakage of steam traps, cooling of the air entering the compressor and injection of steam into the combustion chamber, which have been studied in different scenarios to improve water and energy consumption and reduce environmental impact. In...