Sharif Digital Repository

Along with the development of social and economical development and expansion of urban areas the rate of municipal solid waste (MSW) generation has been increased. Waste-to-Energy technologies consist of any waste treatment process that enables generating energy from a waste source. In recent years many studies have shown that plasma gasification has a considerable potential as an effective method for solid waste treatment and energy recovery. Plasma gasification converts MSW to a clean syngas and its application could reduce MSW volume and the environmental risks of waste landfill. In the present study the methods of waste conversion to energy has been reviewed, then plasma gasification of... 

One atom thick layer of pure carbon in bonded and hexagonal lattice is named graphene. graphene has unique mechanical, optical, thermal and electrical properties and because of these properties has grabbed attention. graphene has been made from high pure graphite by different methods such as CVD(chemical vapor deposition) , chemical exfoliation , micromechanical cleavage and colloidal suspension. through these methods, green methods for synthesis of graphene, using eco-friendly reductants during synthesis of graphene instead of hydrazine and recently using waste(not graphite) are attractive for synthesis of graphene. Following this idea , a group has produced graphene from wastes such as... 

With the increasing population and expanding urbanization and changing consumption patterns and relative prosperity increases, the amount of waste generated has increased significantly. So the municipal waste management as one of the challenges that lie ahead for municipal and state has become. Therefore, different approaches have been proposed to solve this problem. In the past government used landfill or incineration program for waste management. Given the risks to the environment and human health are two ways to create and large amount of biodegradable solid waste, composting seems to be good approach for waste management. With using the process on an industrial scale by municipalities,... 

During production process in Uranium Conversion Facility (UCF) plant at Isfahan, the liquid waste containing uranium compounds, is directed to evaporation lagoons. Gradually, a considerable amount of precipitation will form at the bottom of these lagoons. Uranium concentration in this precipitation is very high and can range from tens of ppm to the order of a few weight percent. As such, it seems that uranium recovery from the UCF waste liquid is not only economically advantageous, but also effective for protecting the environment.The liquid waste resulting from the uranium extraction process contains a great amount of Fluoride ( ppm or higher) which cannot possibly be thrown away into... 

With regards to depleting of fossil energy sources and the country increasing need to energy, some efforts had been done to replacing renewable sources. To do this, due to decreasing greenhouse gasses, increasing the energy the protection sources, rural development and stable fuel supply in future, the biomass sources are take into consideration but one of considered problems of these sources is high cost and lack of infrastructures. Iran is among the countries that its fossil sources are coming to end and also has high potential of biomass sources. This research aim is developing of a model for evaluation of biomass utilization system to finding a path for supplying biomass energy and... 

It is aimed in this study to numerically investigate the effect of contact angle on the heat transfer coefficient in oil-water two-phase flow. For this purpose, the finite element method (FEM) is used to solve the unsteady Navier-Stokes and energy equations. The level set method is also used to capture the interface between the phases. In the first part of the study, two-phase flow of the water and calibration oil is considered in a T-junction geometry at contact angles of 5°, 40°, and 75°. It is observed that the flow patterns formed in the microchannel depend on the initial flow condition which results in the hysteresis phenomenon. Investigating the effect of wall contact angle on the...