With a shift to exploiting unconventional petroleum plays in the United States to support energy consumption, understanding the nanopore systems in those unconventional resources becomes important for future exploitation. The goal of this study is to characterize the pore systems of the Cretaceous Lincoln Limestone found in the Denver-Julesburg (DJ) Basin in order to test the hypothesis that li...

The geochemical composition of foraminiferal tests is a valuable archive for the reconstruction of paleo-climatic, -oceanographic and -ecological changes. However, dissolution of biogenic calcite and precipitation of inorganic calcite (overgrowth and recrystallization) at the seafloor and in the sediment column can potentially alter the original geochemical composition of the foraminiferal test...

Reflectance spectra of carbonate minerals in the shortwave infrared (SWIR) and thermal infrared (TIR) wavelength regions contain a number of diagnostic absorption features. The shape of these features depends on various physical and chemical parameters. To accurately identify carbonate minerals or rocks in pure and mixed form, it is necessary to analyze the effects of the parameters on spectral...

This study investigates the influence of some chemical additives such as methanol, ethanol, sodium oleat, chloroform and sodium hexametaphosphate (SHMP) on the dry fine grinding of calcite (X50= 33 µm) using a stirred media mill. The experiments were carried out by a batch operation, and the change in colour properties (Ry, whiteness and yellowness) of calcite powder. The results showed that th...

Fluoride can be removed from wastewater by addition of calcite. However, fluoride is often found in complex mixtures where other contaminants can affect the removal process. Batch experiments were used to determine the impact of phosphate (PO4 3 ) on the removal of fluoride from solution by calcite. In the experiments, up to 2,000 mg/L F and 500 mg/L PO4 3 were used with 150 mm and 1.18 mm calc...

background: gabaergic interneurons in the hippocampal ca1 area are mutually communicated by gap junctions (gjs) composed of connexin36 (cx36). we examined the role of cx36 in ca1 in manifestation of kindled seizures and hippocampal kindling in rats. methods: quinine, as the specific blocker of cx36, was injected into ca1, and kindled seizures severity was examined 10 min afterward. moreover, qu...

Holocene biotic and abiotic marine calcite have a similar range of Mg contents (0 to 22 and 4 to 2 1 mol% MgC03, respectively), yet biotic calcite has Sr*+ concentrations that are consistently 1250 ppm higher than those of abiotic calcite. As in laboratory experiments, a positive linear relation is observed between Dsr and calcite Mg content. This produces two distinct linear trends on a plot o...

The calcite saturation status of soil-water systems in semiarid regions was reexantined taking into consideration organic ligand alkalinity and Ca-organic complexation. These factors have been forwarded as the reason for earlier reports of calcite Supersaturation in soilwater systems. We examined groundwaters beneath irrigated lands, soil-water suspensions in the laboratory using four soils and...

Soils often show supersaturation with respect to calcite. This study was undertaken to test alternative methods of measuring Ca2+ and COjactivities to assess their effects on measured ion-activity products (IAP) of calcite in soils. Soils were reacted with atmospheric CO,(g) and distilled H 2 0 for 1,3, and 7 d. The soil extracts were analyzed for pH, electrical conductivity (EC), cations, anio...