A survey of the interactions between phosphorus (P) species and the components of calcareous soils shows that both surface reactions and precipitation take place, especially in the presence of calcite and limestone. The principal products of these reactions are dicalcium phosphate and octacalcium phosphate, which may interconvert after formation. The role of calcium carbonate in P retention by ...

[1] Thin coatings of atmospherically deposited dust can mask the spectral characteristics of underlying surfaces on Mars from the visible to thermal infrared wavelengths, making identification of substrate and coating mineralogy difficult from lander and orbiter spectrometer data. To study the spectral effects of dust coatings, we acquired thermal emission and hemispherical reflectance spectra ...

Calcite microfossils are widely used to study climate and oceanography in Earth's geological past. Coccoliths, readily preserved calcite plates produced by a group of single-celled surface-ocean dwelling algae called coccolithophores, have formed a significant fraction of marine sediments since the Late Triassic. However, unlike the shells of foraminifera, their zooplankton counterparts, coccol...

INTRODUCTION The combination of hardness, scratch resistance and flexibility is a highly desired feature in many coating applications. A potential route to achieve this aim is via the introduction of a nanoparticle filler into the polymer resin. The great interest for using nanoparticles to reinforce polymers emerged in the late 1980s when a research group from Toyota reported their findings re...

Tight sandstone has low porosity and permeability, a complex pore structure, strong heterogeneity due to diagenetic modifications. Limited intervals of Lianggaoshan Formation in the Fuling area are cored high costs, thus, model for predicting facies based on logging curves was established few core, thin section, X-ray diffraction (XRD), scanning electron microscopy (SEM), cathodoluminescence, r...

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...

The study of the carbonate cements in the Permian-Triassic Dalan-Kangan formations resulted in the identification of five stages of calcite and dolomite cementation, which completely or partially occluded pores. Cement types appear to be early isopachous calcite (i; C1-non-luminescence), equant (ii; C2-dull CL), fairly coarse secondary dolomite rhombs (iii; C3-zoning red CL), coarse sparry calc...