Thermodynamic Model for Cold Water Survival

A thermodynamic heat flow model for the human body gives survival time as a function of water temperature, assuming constant specific heat and thermal conductance. [S0148-0731(00)01305-4]

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HEAT TRANSFER MODEL FOR PREDICTING SURVIVAL TIME IN COLD WATER IMMERSION

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237205000251 ◽

2005 ◽

Vol 17 (04) ◽

pp. 159-166 ◽

Cited By ~ 9

Author(s):

F. TARLOCHAN ◽

S. RAMESH

Keyword(s):

Heat Transfer ◽

Water Temperature ◽

Survival Time ◽

Cold Water ◽

Water Immersion ◽

Thermal Conductance ◽

Cold Water Immersion ◽

The Body ◽

Complex Nature ◽

Transfer Model

In the present paper a heat transfer (HT) model to estimate survival time of individual stranded in cold water such as at sea is proposed. The HT model was derived based on the assumption that the body specific heat capacity and thermal conductance are not time dependent. The solution to the HT model simulates expected survival time as a function of water temperature, metabolism rate, skin, muscle and fat thickness, insulation thermal conductivity and thickness, height and weight of the subject. Although, these predictions must be considered approximate due to the complex nature of the variables involved, the proposed HT model can be employed to determine supplemental body insulation such as personal protective clothing to meet a predefined survival time in any given water temperature. In particular, the results obtained are useful as a decision aid in search and rescue mission in predicting survival time for shipwreck victims at sea.

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Heat flow model for pulsed laser melting and rapid solidification of ion implanted GaAs

Journal of Applied Physics ◽

10.1063/1.3457106 ◽

2010 ◽

Vol 108 (1) ◽

pp. 013508 ◽

Cited By ~ 12

Author(s):

Taeseok Kim ◽

Manoj R. Pillai ◽

Michael J. Aziz ◽

Michael A. Scarpulla ◽

Oscar D. Dubon ◽

...

Keyword(s):

Heat Flow ◽

Rapid Solidification ◽

Flow Model ◽

Pulsed Laser ◽

Laser Melting ◽

Heat Flow Model ◽

Ion Implanted

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Cold-specific feeding response of rats to cold exposure and energy density of body weight change

Journal of Applied Physiology ◽

10.1152/jappl.1981.51.2.327 ◽

1981 ◽

Vol 51 (2) ◽

pp. 327-334 ◽

Cited By ~ 4

Author(s):

S. D. Morrison

Keyword(s):

Body Weight ◽

Food Intake ◽

Energy Density ◽

Heat Flow ◽

Cold Exposure ◽

Weight Change ◽

Flow Model ◽

Energy Yield ◽

Body Weight Change ◽

Heat Flow Model

The increased food intake of rats exposed to cold is the result of increased intake due to cold (cold-specific compartment; A) and decreased intake due to simultaneously decreased body weight (weight-specific compartment; B). The two compartments are evaluated at 5, 13, and 17 degrees C. B is evaluated as the food intake of theoretical, isogravimetric control (identical to cold-exposed rats with respect to body weight and rate of change of body weight and identical to nonexposed rats in all other respects) that takes into account both the change in energy expenditure due to decreased body weight and the energy yield from tissue catabolism represented by change of body weight. A is the observed food intake minus B. A theoretical heat-flow model, in which expected changes in heat flow during cold exposure drive food intake to maintain or restore preexposure body weight status, corroborated the partition derived from experimental data. However, both the experimental results and the heat-flow model imply that the energy density of body weight change is negatively correlated with rate of body weight change. The energy density of weight change is high with high rates of weight loss and low with high rats of weight gain.

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Conductive and convective heat flows of exercising humans in cold water

Journal of Applied Physiology ◽

10.1152/jappl.1989.67.6.2473 ◽

1989 ◽

Vol 67 (6) ◽

pp. 2473-2480 ◽

Cited By ~ 8

Author(s):

G. Ferretti ◽

A. Veicsteinas ◽

D. W. Rennie

Keyword(s):

Heat Flow ◽

Water Temperature ◽

Convective Heat ◽

Rectal Temperature ◽

Cold Water ◽

Subcutaneous Fat ◽

Skin Surface ◽

Heat Flows

The apparent conductance (Kss, in W.m-2.degrees C-1) of a given region of superficial shell (on the thigh, fat + skin) was determined on four nonsweating and nonshivering subjects, resting and exercising (200 W) in water [water temperature (Tw) 22-23 degrees C] Kss = Hss/(Tsf-Tsk) where Hss is the skin-to-water heat flow directly measured by heat flow transducers and Tsf and Tsk are the temperatures of the subcutaneous fat at a known depth below the skin surface and of the skin surface, respectively. The convective heat flow (qc) through the superficial shell was then estimated as qc = (Tsf - Tsk).(Kss - Kss,min), assuming that at rest Kss was minimal (Kss,min) and resting qc = 0. The duration of immersion was set to allow rectal temperature (Tre) to reach approximately 37 degrees C at the end of rest and approximately 38 degrees C at the end of exercise. Except at the highest Tw used, Kss at the start of exercise was always Kss,min and averaged 51 W.m-2.degrees C-1 (range 33-57 W.m-2.degrees C-1) across subjects, and qc was zero. At the end of exercise at the highest Tw used for each subject, Kss averaged 97 W.m-2.degrees C-1 (range 77-108 W.m-2.degrees C-1) and qc averaged 53% (range 48-61%) of Hss (mean Hss = 233 W.m-2).(ABSTRACT TRUNCATED AT 250 WORDS)

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