Carbonate sediments may be cemented by a variety of forms of aragonite. calcite. or dolomite. The mineralogy of the cement has been regarded by most investigators as the product of the physico-chemical environment within the sediment at the time of cementation. This has been a reasonable working hypothesis until it was recently demonstrated that many different kinds of cement may occur in beach...

Microbial induced calcite precipitation (MICP) offers a host of interesting features, from both theoretical and practical standpoints. This process was firstly investigated as geo-biological mechanism involved in carbonate mineral formation rocks soil. The interest its use has significantly increased recent years, MICP been used different fields, such oil recovery, the improvement soil geotechn...

Reticulated nickel foams were alloyed with 8–9 wt% Al or 14–18 wt% Cr and 5–9 wt% Al in a three-step method consisting of (i) gas-phase deposition of Cr and/or Al onto the struts of a pure Ni foam by pack-cementation at 1000 C; (ii) homogenization at 1200 C to remove concentration gradients and to solutionize the alloyed struts; (iii) aging at 900 C to form c0 precipitates within the struts. Th...

the electrical resistivity of hydrocarbon reservoir rocks is an important parameters in the calculation of water and oil saturation percent in both carbonate and sandstone reservoir rocks.in this regard, most studies have concentrated on the confining  pressure on cementation factor and electrical resistivity in sandstone reservoir rocks. in this study the effect of confining pressure on cement...

Beginning of the twentieth century, population growth, urbanization and industrialization has led to depletion of rapidly building areas. Accordingly, each passing day, the opening of the new construction sites has become mandatory. Among these newly opened areas, geotechnical aspects of construction from time to time in areas not suitable for construction and deployment was seen to improve the...

The volume has the feel of an intimate scrapbook of many of the key events and documents in Darwin’s life. But it is more than just a scrapbook: the words are written by science historian, John van Wyhe. A distinguished Darwin scholar at Cambridge University, van Wyhe is also director of the major project to make the entire work of the evolutionary biologist available electronically. Darwin Onl...

OBJECTIVE To evaluate the marginal gap (MG) and absolute marginal discrepancy (MD) of full ceramic crowns with two finish line designs, shoulder and chamfer, using microcomputed tomography (micro-CT) before and after cementation. MATERIALS AND METHODS Sixty extracted human maxillary premolar teeth were divided into two groups based on the finish line design: Group I: 90° shoulder and Group II...