THE EFFECT OF STANDARD WAVE CONDITIONS ON DRY SUIT INSULATION WHEN MEASURED ON HUMANS
Testing of immersion suits is commonly conducted in calm or circulatory water. Several investigators have argued that this is an unrealistic test for a suit that is designed to protect a human from hypothermia in open ocean conditions. In support of this argument, Steinman et al. (1) and Romet et al.(2) reported a significant reduction of suit insulation in turbulent water when compared to still water by an average of about 30% when measured on humans. Such differences were found for loose-fitting wet suits but were not investigated for dry suits. Recently, Sowood et al. (3) reported a reduction of dry suit insulation by about 30% in turbulent water (wave height of 60 cm) compared to still water when tested on a thermal manikin.
MEASUREMENT OF IMMERSION SUIT INSULATION : A COMPARISON BETWEEN HUMAN SUBJECTS AND A THERMAE MANIKIN
Thermal manikin. Parallel to the human tests, the immersion suit was also tested using a Thermal Instrumented Manikin (TIM, CORD Group Limited, Dartmouth, Nova Scotia) immersed in the same water conditions and at the same time without interfering with the subject or changing the wave pattern. The probe locations (except for the location of the HFTs that were fixed on the pile garment of the manikin instead of the skin as it was for the humans to avoid applying a large correction factor to the heat flow values; see 2) and the clothing were the same as for the human subjects (see 1 for details). The aluminum skin of the manikin was maintained constant and uniform at 25°C during the tests.
Mathematical Time and Physical Time in the Theory Of Relativity
In the Theory of Relativity time is an imaginary quantity that can not be observed; it is a multiplication of a number that indicates duration of material change and number i that is an imaginary number. i on the square is -1. Time i⁄t is a mathematical time that describes the speed and the duration of material change. In the Universe one can observe physical time only as a stream of material change. It is not that change run in physical time, change itself is physical time.. Distinction between imaginary mathematical time and visible physical time opens some new perspectives into interpretation of Theory of Relativity. c