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The pulse radiolysis method has been used to produce ground-state hydrogen atoms in gaseous hydrogen and has been combined with fast Lyman-α absorption spectrophotometry to observe these atoms directly with microsecond time resolution. The technique has been used to study the kinetics of the reaction H + O2 + M = HO2 + M, where M is H2. The rate constant for this reaction was found to have the value (1.7 ± 0.4) × 1010M−2·sec−1 at 298°K. This value, together with earlier data for Ar as third body, gives kH2 / kAr = 2.0 at 298°K for the ratio of the efficiencies of H2 and Ar as third body in this reaction.

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The first weather satellite was launched on 1 April 1960. In the 25 years since, weather satellites have contributed to improved weather analyses and forecasts worldwide. As a maturing component of a global observing system, the meteorological satellite promises even greater financial benefits and a higher quality of life to mankind.

A useful thin-film passive dosimeter system has been developed through use of a poly(halo)styrene matrix doped with malachite green methoxide as an indicator. Extensive characterization studies of the chlorostyrene dosimeters have been completed and the range of conditions under which they are useful has been defined. Exposure to radiation causes development of a blue color (absorption at 630 and 430 nm) which has an optical density proportional to dose over the range 104−107 rad and may be calibrated to above 3×107 rad. No effects of dose rate have been observed between 102 and 1015 rad/sec, and no effects of photon energy between 2 keV x-rays and 1 MeV gamma rays. Of the environmental parameters studied, only extraneous uv light, temperature, and a few noxious gases have a significant effect on the performance of the dosimeters. Oxygen has only a small effect (a few percent) at low dose rates, but acidic gases such as NO2, SO2, and HCl will first color, then bleach the films. The rate and ultimate amount of coloration are dependent on temperature, but this effect is negligible from 0 to 35°C. These films have an indefinite shelf life at room temperature in the absence of light and corrosive gases, and the small effects of oxygen and temperature can be compensated for in the calibration for a particular application.