Future mission studies: Forecasting solar flux directly from its chaotic time series

The mathematical structure of the programs written to construct a nonlinear predictive model to forecast solar flux directly from its time series without reference to any underlying solar physics is presented. This method and the programs are written so that one could apply the same technique to forecast other chaotic time series, such as geomagnetic data, attitude and orbit data, and even financial indexes and stock market data. Perhaps the most important application of this technique to flight dynamics is to model Goddard Trajectory Determination System (GTDS) output of residues between observed position of spacecraft and calculated position with no drag (drag flag = off). This would result in a new model of drag working directly from observed data

Blueshift in MgxZn1-xO alloys: nature of bandgap bowing

A Mg composition-dependent blueshift has been studied in MgxZn1−xO alloys deposited on 6H-SiC(0001) substrates. The localized exciton energy in MgxZn1−xO alloys for x ∼ 0.3 was blueshifted in the range 212–248 meV. The large negative bowing parameter was estimated in MgxZn1−xO alloys to be 4.72±0.84 eV. This large bandgap bowing emphasizes the Stokes shift, which has been attributed to the existence of spontaneous polarization effects due to the polar growth of MgxZn1−xO/SiC heterostructure and local compositional inhomogeneity