Sharif Digital Repository

An understanding of the effect of degree of cementation on static behavior of cemented soils in becoming increasingly important in design and analysis of geotechnical engineering problems. Naturally cemented coarse-grained soils are widely present in many parts of the world. Misunderstanding of the behavior of such soils could lead to under or overestimate of the soil parameters. Previous studies conducted by Prof. Haeri and his co-workers show that most of the alluvial deposit of Tehran, the capital city of Iran. The amount and characteristics of the cementation of the deposit varies in different parts from highly cemented in the north to non-cemented in the south. This deposit consists of... 

An understanding of the effect of degree of cementation on static and dynamic behaviour of cemented soils is becoming increasingly important in design and analysis of geotechnical engineering problems. Naturally cemented coarse-grained soils are widely present in many parts of the world. Misunderstanding of the behaviour of such soils could lead to underestimate or overestimate of the soil parameters. Previous studies conducted by Haeri and his co-workers show that most of the alluvial deposit of Tehran, the capital city of Iran, has a soil with cemented nature. The amount and characteristics of the cementation of the deposit varies in different parts from highly cemented in the north to... 

The aim of this study is developing and investigating heterogeneous catalysts based on natural calcite for the transesterification of canola oil and methanol in order to produce biodiesel as a renewable and alternative fuel for fossil fuels. At first calcite was calcined at high temperature to decompose calcium carbonate to calcium oxide. Afterward, Mg-Zr/CaO catalysts were prepared with mass ratio of 2:1 Mg:Zr and different weight percent(2.5, 5,7.5 and 10 wt%) on calcite supported by impregnation method. In order to characterized synthesized catalysts used different analysis such as energy dispersive X-ray (EDX) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy... 

Acidizing is the most widely performed job to remove the formation damage, and enhance the oil recovery. Different models have been introduced to design the optimized condition for acidizing. However, none of them are able to predict the optimum injection flow rate in the actual application. As a result, Calcite cores are extracted from reservoirs for conducting experiments and modifying the present models. Nevertheless, acidizing is an intrusive technique destroying the costly extracted cores. Thus, there is a need to construct calcite cores of various porosities and permeabilities to take advantage of them in acidizing modelling.Microbially induced calcite precipitation is a well-known... 

Low salinity/smart waterflooding is simple to apply and a promising enhanced oil recovery method in which ion-tuned saltwater is injected into subsurface oil reservoirs. Many aspects of this operation, in particular those pertaining to nano-scale, are not yet fully understood. The present dissertation is an attempt to shed light on the microscopic properties and behavior of rock/brine/oil interfaces throughout low salinity/smart waterflooding. Several simulations were carried out for oil/brine and calcite/brine categories each containing various ions and hydrocarbons compounds. The surface contribution of non-functional oil compounds (aromatics and aliphatics) near brine medium was...