Thermal strain indicators temperature

Since thermal strain is not determined by single climate parameters, it is not useful to link decisions or recommendations regarding the risks of participating in sports events to temperature, wind, humidity, or radiation alone. Instead, it is better to use climatic indices. 

During exercise in the heat, sweat loss is the main mechanism to lose heat. Core temperature increases more when hypohydrated as compared to euhydrated subjects. Therefore, an international standard, ISO 7933, was based on the ratio between the amount of sweat that should be evaporated to stay in thermal equilibrium and the amount of sweat that can be evaporated maximally. This required sweat rate index (Ereq) standard is replaced with the Predictive Heat Strain Index developed by Malchaire (2006). This index is mainly used for the industry. Sometimes thermal strain is combined with thermal stress indicators in order to make an individual recommendation for performance limits (Epstein and Moran, 2006). 

Theoretical studies indicate that for dt < 2 nm the effect of strain energy exceeds that of the room temperature thermal energy, so that it is only at small nanotube diameters that the strain energy associated with nanotube... 

From the dynamic mechanical investigations we have derived a discontinuous jump of G and G" at the phase transformation isotropic to l.c. Additional information about the mechanical properties of the elastomers can be obtained by measurements of the retractive force of a strained sample. In Fig. 40 the retractive force divided by the cross-sectional area of the unstrained sample at the corresponding temperature, a° is measured at constant length of the sample as function of temperature. In the upper temperature range, T > T0 (Tc is indicated by the dashed line), the typical behavior of rubbers is observed, where the (nominal) stress depends linearly on temperature. Because of the small elongation of the sample, however, a decrease of ct° with increasing temperature is observed for X < 1.1. This indicates that the thermal expansion of the material predominates the retractive force due to entropy elasticity. Fork = 1.1 the nominal stress o° is independent on T, which is the so-called thermoelastic inversion point. In contrast to this normal behavior of the l.c. elastomer... 

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