احسان الوند

The adsorption of polymeric systems onto reservoir rock through altering the wettability of rock surface improves oil recovery and reduces the unwanted water production. . In this study, the adsorption behavior of dilute polymeric systems based on sulfonated polyacrylamide on the glass particles surfaces (representative of sandstone reservoirs) was investigated and the effect of this phenomenon on changing their surface properties was examined. Results show that crosslinked polymeric samples have lower adsorption on glassy surface comparing with uncrosslinked sulfonated polyacrylamide solution. Furthermore, the contact angle tests results showed that crosslinked samples change the surface property of glass particle less than sulfonated polyacrylamide solution. In addition the Langmuir isotherm model fitted the isotherm data better than the Freundlich model for these dilute polymeric systems. Furthermore, study of the thermodynamic of adsorption showed that their adsorption behavior on glassy surfaces is a spontaneous and exothermic process.

Decision-making in the Integrated Watershed Management is quite complex due to existence of various factors and indices there. To access a specific purpose, there are several solutions, each with a different priority to the different issues such as physical, ecological, socioeconomic, and political and security sectors. This requirement leads naturally to multi-criteria decision-making method, which aims to choose the best answer from among the possible solutions. The solution of decision-making problems so complex that the finding an acceptable solution is not easily possible. In particular, they often conflict with each other, so the increase of the value of one factor in priority could reduce the desirability of another one. Therefore, a special case study (the prioritizing of managerial scenarios for Chel-chai Watershed, Golestan Province) is performed to survey the differences in rate of response, due to changes in the types of compensatory multi-criteria decision-making techniques. In this study, four standards of physical, social, economic, and ecological indices, with two different weighting methods (quantitative and qualitative) are used. In order to prioritize management scenarios, some proposed techniques of TOPSIS, SAW, linear assignment, and VIKOR are utilized. Finally, in order to combine rankings, the techniques of Borda and Copeland are applied. According to the obtained results from all the methods proposed to prioritize scenarios, Scenario A (maintain status quo) is validated as the last priority in the list. However, the scenarios with having the garden is the first priority, and the scenarios with agroforestry and forestry activities are listed as end ones. According to the results, here gardening is an important activity, which needs special attention, and other activities are next priorities. Furthermore, we can say that the weights assigned to the criteria in prioritizing scenarios have a significant impact. There should be given careful consideration in calculating the importance weights. The results of the combined ranking of the proposed techniques using two different weighting methods are more compatible with the VIKOR method. Therefore, this method can serve as an appropriate technique to prioritize scenarios.

The nondestructive techniques are applied to identify important data from the internal process of distillation towers, process towers, pressure vessels and etc. In recent, the gamma-ray scanning techniques as diagnostic tools for scanning of tray columns, packed columns, storage tanks, level measurement and density measurement of containing materials has been used widely. This paper has tried to model tray column failures. Also failures identification using real time analysis and scan profile interpretation has been investigated. This suggested model can be used before gamma ray scanning technique, calibration and adjustment of working conditions in industrial scale.