Sunlight glitter on a wind-ruffled sea: further studies.
Time-averaged intensities are computed for the glitter pattern of sunlight on a wind-ruffled sea. In the present work the azimuthally asymmetric form of the wave-slope distribution measured by Cox and Munk is used, so that the glitter pattern depends on the wind direction as well as magnitude. Results are calculated for both a clean ocean surface and one covered with an oil film. The glitter pattern is quite different with the oil film due to the quieting action of the oil on the waves, the greater reflectivity of the surface when oil is on the surface, and the larger values of polarization for the reflected light at most typical angles in the glitter pattern. These effects are illustrated and discussed as possible methods for the detection of oil slicks. The glitter pattern observed at satellite altitudes is also calculated.
Blue sun glints on water viewed through a polarizer.
Sun glints are formed by specular reflections of the sun from capillary waves formed by wind blowing over water. These glints are normally colorless for a high sun or take on the color of the light source, such as orange-red during sunset or sunrise. However, when the glints are highly polarized by reflection near the Brewster angle, i.e., with relatively high sun they can change from colorless to a blue appearance caused by blue light leakage through a polarizing filter oriented orthogonal to the plane of polarization of the reflected light. Measurements are shown of crossed-polarizer transmission spectra exhibiting blue and near infrared light leakage for photographic polarizing filters and polarized sunglasses. A variety of photographs is shown to confirm blue light leakage as the source of the blue glint color.
Portable Computing in Psychiatry
Personal digital assistants (PDAs) or handheld computers have become more popular in the practice of medicine. These devices have implications for psychiatric practice, and this paper reviews various published articles describing their use. The literature demonstrates their use in document editing, patient tracking, accessing medical information and drug reference guides, prescription writing, and medical education. Security on these devices is covered, and the value and increasing implementation of PDAs in psychiatry is discussed.