Cassini measurements of cold plasma in the ionosphere of Titan.

The Cassini Radio and Plasma Wave Science (RPWS) Langmuir probe (LP) sensor observed the cold plasma environment around Titan during the first two flybys. The data show that conditions in Saturn's magnetosphere affect the structure and dynamics deep in the ionosphere of Titan. The maximum measured ionospheric electron number density reached 3800 per cubic centimeter near closest approach, and a complex chemistry was indicated. The electron temperature profiles are consistent with electron heat conduction from the hotter Titan wake. The ionospheric escape flux was estimated to be 10(25) ions per second.

Radio and plasma wave observations at Saturn from Cassini's approach and first orbit.

We report data from the Cassini radio and plasma wave instrument during the approach and first orbit at Saturn. During the approach, radio emissions from Saturn showed that the radio rotation period is now 10 hours 45 minutes 45 +/- 36 seconds, about 6 minutes longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive radio signals were detected from Saturn lightning during the approach and first orbit. Some of these have been linked to storm systems observed by the Cassini imaging instrument. Within the magnetosphere, whistler-mode auroral hiss emissions were observed near the rings, suggesting that a strong electrodynamic interaction is occurring in or near the rings.

Handheld ophthalmoscopes for hazards analysis: an evaluation.

The spectral irradiance was measured from twenty handheld ophthalmoscopes. The optical radiation emitted from each ophthalmoscope was compared to the threshold limit values (TLV(s)) for acute effects published by the American Conference of Governmental Industrial Hygienists. All ophthalmoscopes tested were found to emit unnecessary ultraviolet and infrared radiation in addition to visible light. The levels of optical radiation emitted from most of the ophthalmoscopes were below the applicable TLV(s). Nevertheless, suitable blocking filters can reduce the emission of ultraviolet and infrared radiation. Use of the ophthalmoscopes at the lowest possible power would further minimize patient exposure.

An evaluation of optical radiation emissions from dental visible photopolymerization devices.

Five devices were tested for the amount of optical radiation they emitted. Recommended values can be exceeded with a workload of 17 to 81 applications in any 167-minute period. Some procedures, such as close viewing distances, direct view applications, and treating the anterior teeth may increase the exposure to the user.