A series of ring shear tests were conducted to investigate the ultimate particle size distribution a carbonate sand. The carried out under different stress levels, on three types specimens: 1) uniformly graded specimens made dry natural sand 2) remoulded crushed after first shearing large strains 3) grains but with same grading as in (2). type (1), very strains, led apparently stable gradings, ...

Calcareous sediments are located in temperate and tropical areas near offshore hydrocarbon industries and petrochemical reserves such as the Persian Gulf of Iran. These sediments have complicated physical properties which make them completely different from silicate soils. Carbonate sediments are mainly formed by the skeletal remains of marine organisms. Therefore, a wide variety of engineering...

Contamination by radioactive strontium ((90)Sr) is a significant environmental problem. Ureolytically driven calcium carbonate precipitation has been proposed for use in geotechnical engineering for soil remediation applications. In this study, 68 ureolytic bacterial strains were newly isolated from various environments. Of these, 19 strains were selected based on ureolytic activity shown when ...

In this study, a series of nuclear magnetic resonance (NMR) tests was conducted on calcareous sand, quartz and glass bead with wide range grain sizes, to understand the effect size micro-pore structure fractal characteristics carbonate-based sand silicate-based sand. The pore distribution (PSD) tested materials were obtained from NMR T2 spectra, theory introduced describe properties PSD. Result...

Burrowing by thalassinidean shrimp in modern tropical, shallow-subtidal to intertidal carbonate environments is widespread and a powerful agent of bioturbation, particularly within sandy substrates. Deep and intense burrowing by callianassids commonly occurs along the intertidal margins of hypersaline lagoons throughout the Bahamas, such as Pigeon Creek on San Salvador Island, where the sedimen...

Coral reef benthic communities are mosaics of individual bottom-types that are distinguished by their taxonomic composition and functional roles in the ecosystem. Knowledge of community structure is essential to understanding many reef processes. To develop techniques for identification and mapping of reef bottom-types using remote sensing, we measured 13,100 in situ optical reflectance spectra...