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The ultraviolet spectrometers that observed the atmosphere of Mars in July and August of 1969 consist of a planetary coronagraph and an Ebert-Fastie monochromator. The spectral range 1100-4300 A was measured using two photomultiplier tubes, one with a cesium iodide photocathode, the other with a bialkali photocathode. These tubes were operated with fixed(More)
The in vivo emission spectra of sixteen species of Jamaican fireflies and four species of American fireflies have been measured with a photoelectric recording spectrometer. A simple technique of stimulation with ethyl acetate vapor was found to elicit bright continuous emission over a period of several minutes. Although the luciferin-luciferase(More)
Bioluminescence measurements made by stimulation of the organisms in a jet of water directed at the face of a phototube have increased the sensitivity of data by a factor of 1000 over "spontaneous" luminescence measurements. In light-baffled cells it has been possible to map the surface bioluminescence of large areas continuously in broad daylight.(More)
A Lyman-alpha airglow of atomic hydrogen measured in the outer atmosphere of Venus showed that atomic hydrogen is present. The variation as a function of height indicates that the temperature of the upper atmosphere of Venus is lower than that of Earth. An ultraviolet airglow of atomic oxygen was not found. An ultraviolet nightglow was observed on the dark(More)
An ultraviolet spectrometer aboard the Apollo 17 orbiting spacecraft attempted to measure ultraviolet emissions from the lunar atmosphere. The only emissions observed were from a transient atmosphere introduced by the lunar landing engine. The absence of atomic hydrogen implies that solar wind protons are converted to hydrogen molecules at the lunar surface.
Portable light-baffled underwater photometers have been designed for the measurement of dinoflagellate bioluminescence by day and night. Maximal light emission is obtained by mechanical stimulation in a defined volume. The pump which stimulates the dinoflagellates also constantly replenishes the sample volume so that continuous measurements are possible.(More)
Comprehensive measurements in the vacuum uv range of 1200-3000 A of efficiency, polarization, and scattering of classically ruled and photoresist gratings are reported. The results show that the art of ruling gratings for vacuum uv use has reached a high level of sophistication and that careful analysis of grating properties can lead to useful improvement(More)
We discuss the characteristics of a Quadrant-CCD developed by Tektronix for pointing and tracking applications. The device is discussed in the context of its application to the Johns Hopkins University adaptive optics program, where it is being used for the correction of stellar image motion resulting from atmospheric turbulence. The transfer function of(More)