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.
The Effects of Wave Conditions on Dry Immersion Suit Insulation: A Comparison Between Humans and Manikin,
Abstract : The objective of the present study was to investigate the effect of standard wave conditions (0 to 70 cm) on dry immersion suit insulation when tested on humans and a manikin simultaneously. Six human subjects and a thermal manikin dressed with the same dry immersion suit system (pile undergarment insulation, uninsulated immersion suit and neoprene gloves and hood) were immersed simultaneously for one hour in 16 deg C water rendered turbulent with an irregular wave pattein. One immersion was performed for each randomly chosen wave condition, from 0 to 70 cm wave height, changing by steps of 10 cm. In addition to the physiological parameters measured on the human subjects (skin and rectal temperatures, skin heat loss and heart rate), and the ambient temperature of water and air, heat fluxes and surface temperatures were measured at 12 sites on the subjects and manikin for each compartment of the dry suit system (skin, pile garment, suit garment). This allowed the calculation of the thermal resistance of every suit compartment in addition to the air and water boundary layer surrounding the suit. The results showed that none of the physiological parameters were significantly affected by the wave conditions, except for the skin heat flux which increased with wave height from 72.0 +/- 1.9 W m(-2) at 0 cm to 85.5 +/- 2.9 W m(-2) at 70 cm. The thermal resistance data showed that wave height up to 70 cm decreased dry suit system insulation by 14 and 17% when measured on human subjects and manikin, respectively; and that the only suit component significantly affected by the wave motion was the insulation of the water and air boundary layers surrounding the body. The body sites that were the most affected by the effect of wave motion were the head, and the proximal limbs with a 58% and 63% decrement in suit thermal resistance from 0 to 70 cm wave height for humans and mani
Nuclear Astrophysics with Radioactive Beams
The quest to comprehend how nuclear processes influence astrophysical phenomena is driving experimental and theoretical research programs worldwide. One of the main goals in nuclear astrophysics is to understand how energy is generated in stars, how elements are synthesized in stellar events and what the nature of neutron stars is. New experimental capabilities, the availability of radioactive beams and increased computational power paired with new astronomical observations have advanced the present knowledge. This review summarizes the progress in the field of nuclear astrophysics with a focus on the role of indirect methods and reactions involving beams of rare isotopes.