Sharif Digital Repository

In this paper we seek to find the contribution of groundwater in irrigation agriculture in Iran. We use nationwide panel data of agricultural production in the period of 1993-2013. The results show us differences in productivity of agricultural outputs due to availability of groundwater. Panel data allows us to control regional factors like soil fertility affecting the productivity. We are looking for the main contributors to groundwater usage. Population growth in demand side and groundwater availability in supply side seem to be the most important factors  

Preformed particle gels (PPGs) due to its advatantage over commonly used in situ gels has been successfully applied for controlling excess water production in mature oil reservoirs. Field results of using PPGs in oil fields shows that commonly used PPGs are highly sensitive to hard reservoir conditions such as high temperature and salinity and can not effectively block fractures and high permeability layers.Objects of this study are synthesis and evaluating performance of this novel polymer based hydrogel in oil reservoirs with high temperature and salinity. Central composite design ( which is a experiment design approach) was used for synthesizing thirteen gel samples and optimal sample was... 

Nowadays, as a result of population growth and groundwater resources pollution, many countries in the world are facing serious water crises. Several alternative solutions have been investigated to overcome this obstacle. Atmospheric water vapor processing (AWVP) is a new solution to generate freshwater from ambient moist air. The atmosphere surrounding the earth is potentially a valuable water resource which contains a large amount of freshwater. This paper addresses the effectiveness of thermoelectric coolers (TECs) for refrigeration to produce freshwater from ambient air. Consequently, both numerical and experimental analysis are then used as the basis of water production calculation. 18... 

The current work studies the economic investigation of reverse osmosis (RO) desalination unit and multi-effect distillation (MED) considering the average global and also Iran circumstances. Technical and operational parameters are taken into account for economic modeling of both methods to choose the proper and economic method for water desalination based on different operational conditions. The cost of the desalination plants is investigated in two different parts of capital cost and operating and maintenance cost. Capital cost is divided into direct and indirect cost subsections. Based on these calcifications, the effect of economic parameters on change of capital cost and operating and... 

As the reservoir matures, especially in fractured reservoirs, oil production is usually accompanied by the production of some unwanted water. Water production causes environmental problems and imposes high costs on the production system, including the cost of separating water and oil, corrosion of facility, and sometimes, leading to abandoning well. One way to solve this problem is to use gels as a blocking agent. Today, preformed particle gels are used as an alternative to in situ gels, which can solve some issues of in-situ gels, such as uncertainty in gelling time and penetration depth.This research comprises three main parts. In the first part, four samples of preformed particle gels... 

Access to potable water with standard quality is an inevitable component of human’s lives. Seawater desalination is the precedure of removing the impurities and contaminants in water to achieve the suitable quality for human consumption. Freeze desalination, by consuming relatively much lower energy compared to other techniques has shown to be a promising method for desalination. This technique requires the exertion of a cold source to the system which is then accompanied by simultaneous rejection of the impurities from the water. Regarding this, a numerical study on freeze desalination a hollow cylinder is carried out to determine the effects of the design variables such as heat flux,...