Wind tunnel simulations of light and dark streaks on Mars

Wind tunnel experiments have revealed a characteristic flow field pattern over raised-rim craters which causes distinctive zones of aeolian erosion and deposition. Comparisons of the results with Mariner 9 images of Mars show that some crater-associated dark zones result from wind erosion and that some crater-associated light streaks are depositional.     

Laser annealing of ion-implanted semiconductors

The physical and electrical properties of ion-implanted silicon annealed with high-powered laser radiation are described. Particular emphasis is placed on the comparison of materials properties that can be achieved with laser annealing to those which can be achieved by conventional thermal annealing. Applications of these techniques to the fabrication of high-efficiency solar cells, and potential applications of this new technique to other materials areas are discussed.     

Spectrum line intensity as a surrogate for solar irradiance variations

Active Cavity Radiometer Irradiance Monitor (ACRIM) solar constant measurements from 1980 to 1986 are compared with ground-based, irradiance spectrophotometry of selected Fraunhofer lines. Both data sets were identically sampled and smoothed with an 85-day running mean, and the ACRIM total solar irradiance (S) values were corrected for sunspot blocking (S(c)). The strength of the mid-photospheric manganese 539.4-nanometer line tracks almost perfectly with ACRIM S(e), Other spectral features formed high in the photosphere and chromosphere also track well. These comparisons independently confirm the variability in the ACRIM S(e), signal, indicate that the source of irradiance is faculae, and indicate that ACRIM S(e), follows the 11-year activity cycle.