Sharif Digital Repository

MP210 alloy is a member of multiphase family alloys, a class of wrought nickel-cobalt base alloys extensively used in high-quality applications including aerospace fasteners, gas turbine engines and petrochemical industry. Very limited information can be found in the literature about the microstructure and phase transformations of this alloy. The aim of this work is characterizing the aging response of the material and identifying the major strengthening phases precipitated in different range of temperatures and also studying the static recrystallization behavior of this alloy. The effect of age-hardening heat-treatment on the microstructure of MP210 superalloy was investigated using... 

Complicated theories dominated toward interacting of coastal regions resulted from its nature. Besides of that interference of human activities for acquiring beneficial aspects of shorelines causes environmental considerations to be challenged. One of the main factors for resolving this challenge is to obtain adequate information from hydrodynamic process and sediment regime. In spite of scientific researches that carried out along past three decades for understanding the exact mechanism of along shore sediment transport, it was not fully developed. One of the main reasons of uncertainty for forecasting the sediment regime regarded not exact knowledge of how sediment act in different... 

In this study, the effect of submerged vanes on the bed scouring and deposition pattern at a 90̊ open-channel junction was investigated. First, the bed formation without submerged vanes were studied under the effect of hydraulic variables like the discharge ratio of tributary to main channel and the ratio of mean approach velocity to the threshold velocity. The results show that scour holes enlarge with time while they move towards the downstream and the outer wall in the main channel. Also, by increasing the ratio of mean approach velocity to the threshold velocity about 0.5, the maximum scour depth occurred at the downstream junction corner with time. In the second stage, the proper vane... 

Asphaltene precipitation and deposition may cause severe problems during different stages of oil recovery. All proposed remediation techniques have proven costly and not highly effective, so prevention becomes the most beneficial way to counteract the problem. Revelation of the deposition mechanism and determination of the parameters are necessary in order to devise reliable prevention strategies.This work presents results of the effect of lean gas and CO2 injection process as well as natural depletion on dynamic asphaltene precipitation and deposition. In addition sets of experiments were performed in the same porous media using STO and solvent (with different volume ratios) to investigate... 

Urbanization expansion increases impermeable surfaces and ultimately produces more runoff from urban surfaces. The runoff in the urban streets moves the pollution with high levels from the city and then collects into channels where they are transported into the water courses. The most important factor in runoff polluting is sediments. If you remove sediments from runoff, their quality will be improved. One of the effective systems to reduce sediments from the surface runoff is permeable pavement. In this study a simulator system is used. The sample of permeable pavement analysed consisted of two layers of geotextile beddig, filter granular layer (2.36 to 4.75mm), subbase granular layer (4.75... 

Construction of some structures including parks, bridges and leading walls conducted on the rivers in urbanization leads to the change in the form of the rivers and consequently the change in the hydraulic.The response of river to these changes which are in the form of changes in morphologic features seems to pose some threats such as flood, damage to the buildings located on the route, weakening the bridge of highways and aggradation and degradation of the ecosystem. Kan river, one of the biggest urban rivers in the mega city of tehran, has had some changes such as resort purposes, canalization, the change of slip and roughness and intersection with different bridges during recent...