The transition from invertebrate calcium carbonate-based calcite and aragonite exo- and endoskeletons to the calcium phosphate-based vertebrate backbones and jaws composed of microscopic hydroxyapatite crystals is one of the great revolutions in the evolution of terrestrial organisms. To identify potential factors that might have played a role in such a transition, three key domains of the vert...

Selective solid-phase reduction of iron and phosphorus in oolite ores the Lisakovsky Ayat deposits was experimentally studied. Using X-ray phase analysis, composition initial samples after roasting determined. Goethite, magnetite quartz were found both deposits. Phosphorus ore deposit is form aluminum phosphate hydrophosphate, – as a component calcium hydrophosphate. Experiments on carried out ...

Abstract. The purpose of the work was to study effect high doses superphosphate on yield forage beans and composition phosphates in dark gray forest soil. Research methods. studies were carried out a microfield experiment. Doses are calculated taking into account increase phosphorus content from medium very high. total determined after calcining soil, mineral group natural state soil an extract...

Doping calcium phosphates with ionic species can play an important role in biological responses promoting alkaline phosphatase activity, and, therefore inducing the generation of new bone. Thus, in this study, the synthesis of niobium-doped hydroxyapatite (Nb-HA) nanosize particles obtained by the precipitation process in aqueous media followed by thermal treatment is presented. The bioceramics...