Abstract. Cubic crystalline oxides such as Y2O3 and MgO is used to stabalized zirconia phases at high temperature. In this paper the Y2O3 powder was added to stabilized zirconia and preparing a mixture of MgAl2O4 Spinel by mixing 1mol of nano-MgO with 1 mol of nano-Al2O3 powders. The spinel was added to the Y2O3-ZrO2 by various weight percentage (5, 10, 15, 20 and 25 wt%), and after that the sp...

Natural spinel (MgAl2O4) usually contains some minor and trace elements (e.g., Cr, Co, Fe, V) that may cause various hues. The ratios of these chromophores directly affect the color composition. red in is attributed to combination significant Cr V. Magenta purple blue green colors spinels are affected by Fe concentration, whereas orange shows contribution V content compared Fe. After heating ex...

A search was conducted for grains of the potential core-collapse supernova (SN) condensate minerals corundum (Al2O3), hibonite (CaAl12O19), and spinel (MgAl2O4) among grains filtered from the 308.6 m Guliya ice core recovered from the Qinghai-Tibetan plateau in China. Simple models are developed and calculations are presented to estimate the number of Al2O3 grains that would be deposited per cm...

a basic alumina-spinel low cement castable (lcc) composed of sintered bauxite, reactive alumina, calcined alumina, calcined magnesia, microsilica, and high alumina refractory cement was prepared (castable a) to which 5% sodium hexa-meta phosphate was later added (castable b) to prepare samples for heat treatment at 110ºc, 900ºc, and 1400ºc. bulk density (bd), apparent porosity (ap), and cold cr...

We present opacity sampling model atmospheres, synthetic spectra and colors for brown dwarfs and very low mass stars in two limiting case of dust grain formation: 1) inefficient gravitational settling i.e. the dust is distributed according to the chemical equilibrium predictions, 2) efficient gravitational settling i.e. the dust forms and depletes refractory elements from the gas, but their opa...