Understanding the nature of dust condensation in the outflow from oxygen-rich asymptotic giant branch stars is a continuing problem. A kinetic model has been developed to describe the formation of gas-phase precursors from Ca, Mg, Fe, SiO and TiO in an outflow cooling from 1500 to 1000 K. Electronic structure calculations are used to identify efficient reaction pathways that lead to the formati...

Hydroxyapatite (HA) is one of the most commonly used materials for the coating of bioceramic titanium (Ti) alloys. However, HA has poor mechanical properties and a low bonding strength. Accordingly, the present study replaces HA with a composite coating material consisting of fluorapatite (FA) and 20 wt % yttria (3 mol %) stabilized zirconia (ZrO₂, 3Y-TZP). The FA/ZrO₂ coatings are deposited on...

• Pristine CaTiO 3 has no activity for SCR deNO x , while Ce-Fe-Mn doped could achieve almost 100% NO conversion at 135°C (GHSV = 72000 h -1 ). By selectively activating gaseous molecules, Ti, Fe, and Mn present apparent synergistic effects on accelerating the catalytic cycle of standard SCR. The photocarriers intensify oxidation rather than NH -to-NH 2 transformation. Although photocatalysis e...

Abstract Biomedical applications make high demands on the development of novel bioactive materials, which are often based functionalized calcium phosphates (CaPs). In this study, pure nanoscaled hydroxyapatite (HAp) and modified HAp with titanium dioxide (TiO 2 ) both nano‐ microparticles successfully synthesized from reactants hydroxide orthophosphoric acid in a wet chemistry reaction. The obt...

Abstract Compact type A calcium‐aluminum‐rich inclusions (CTA CAIs) are believed to have experienced partial melting that erased all information on their original nebular condensation. To investigate this question, we report new microstructural data a CTA CAI, composed primarily of melilite, spinel, and perovskite, in the Northwest Africa 5028 CR2 chondrite. The melilite grains contain low (5–1...

En Colombia, el cultivo de sacha inchi (Plukenetia volubilis, L) se siembra como alternativa para la sustitución del coca. La planta adapta a los diversos ecosistemas, pero son escasas las investigaciones su desempeño en diferentes gradientes altitudinales. El objetivo investigación fue analizar relación entre altitud (0 m.s.n.m.- 1.800 m.s.n.m.), y peso semillas, rendimiento aceite torta, mate...

In this paper, we review the current theory of very low mass stars model atmospheres including the coolest known M dwarfs, M subdwarfs, and brown dwarfs, i.e. T eff ≤ 5, 000 K and −2.0 ≤ [M/H] ≤ +0.0. We discuss ongoing efforts to incorporate molecular and grain opacities in cool stellar spectra, as well as the latest progress in deriving the effective temperature scale of M dwarfs. We also pre...