Aviat Space Envir Md
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Asian, European, and American Indian men were subjected to craniofacial cooling to determine relative ranking and temperature curves for various facial skin sites. Moving and still air 0 degrees C to -35 degrees C in both laboratory and subarctic outdoor settings were used. The objective was to examine resistance to facial frostbite. ⋯ Racial differences in face temperatures were clearly shown at only the malar eminence, and there was some evidence that exercise can be used to enhance facial circulation. These results and those of other studies reviewed demonstrate that facial sites cooled by convection are usually ranked from forehead (warmest) through malar, cheek, and chin, to nose (coldest). When cooled by still air, the sites tend to retain that same ranking, but there is more variation in ranking.
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Aviat Space Envir Md · Jan 1979
Application of a bubble formation model to decompression sickness in rats and humans.
Although decompression sickness results from bubble formation in blood or tissue, pressure schedules currently in use are essentially empirical and contain little input from cavitation theory. The recent convergence of three lines of investigation suggests that a synthesis of practice and theory may now be possible. ⋯ We demonstrate that the model is also in good agreement with data on rats and humans over a wide range of pressures and that the model parameters assume sensible values in each case. This suggests that cavitation theory can provide a rationale for current diving practice and can serve to secure, consolidate, and extend this practice.
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Aviat Space Envir Md · Sep 1978
Alternating measurement of ambient and cabin ozone concentrations in commercial jet aircraft.
Ambient and cabin-air ozone concentrations were determined with an adapted commercial ozone analyzer installed in a KLM DC-10 from Amsterdam to Toronto and back. Cabin levels were detected directly and almost continuously; ambient levels were measured using a sampling system in which the ambient samples were converted to the cabin pressure at intervals of 13 min. ⋯ For about 50% of the total flying time, the ozone level exceeded 200 parts per billion, by volume (ppb) in the cabin, with peak concentrations of about 600 ppb (TLV levels of 80--100 ppb apply in most IATA countries). Finally, medical and technical recommendations are made for future measurements.