Recent high precision (142)Nd isotope measurements showed that global silicate differentiation may have occurred as early as 30-75 Myr after the Solar System formation [Bennett V, et al. (2007) Science 318:1907-1910]. This time scale is almost contemporaneous with Earth's core formation at approximately 30 Myr [Yin Q, et al. (2002) Nature 418:949-952]. The (182)Hf-(182)W system provides a power...

We model the positional dependence of the optical polarization (BVRI–bands) in the circumstellar disc of β Pictoris as observed by Gledhill et al. (1991) and Wolstencroft et al. (1995). The particles are spherical, have a size distribution n(a) ∼ a and their number density decreases with distance from the star as r. We consider both compact and porous grains. Varying the grain size and the expo...

INTRODUCTION The aim of this study was to evaluate MTA Plus (Prevest Denpro Limited, Jammu, India, for Avalon Biomed Inc) material's properties, namely calcium release, the pH change, solubility, water sorption, porosity, surface morphology, and apatite-forming ability after immersion in simulated body fluid. METHODS Two tricalcium silicate powders (MTA Plus and ProRoot MTA; Dentsply Tulsa Sp...

The viscosity and diffusivities of silicate melts under high-pressure, high-temperature conditions are difficult to obtain experimentally. Estimation and extrapolation of transport coefficients are further complicated by their extreme sensitivity to melt composition. Our molecular-dynamics simulations show that, over a broad range of melt composition, temperature, and pressure, the diffusivitie...

Silicate glasses and melts have been of interest to mineralogists, geochemists and igneous petrologists for many decades. Silicate melts are essential components of igneous processes, participating actively in Earth differentiation, heat transfer and global geodynamics, and geochemical cycles. Melt viscosity can decrease some 20 orders of magnitude below that of corresponding solids, and timesc...

Space localization of the linear and nonlinear optical properties in a transparent medium at the submicron scale is still a challenge to yield the future generation of photonic devices. Laser irradiation techniques have always been thought to structure the matter at the nanometer scale, but combining them with doping methods made it possible to generate local growth of several types of nanocrys...