Thermal regulation elements

The thermal parameters for comfort should be relatively uniform both spatially and temporally. Variations in heat flow from the body make the physiological temperature regulation more difficult. Nonuniform thermal conditions can lead to nonuniform skin temperatures. The active elements of the regulatory system may need to make more adjustments and work harder in order to keep thermal skin and body temperatures stable. To avoid discomfort from environmental nonuniformities, the temperature difference between feet and head should be less than about 3 °C (Fig. 5.9) and the mean surface temperature or radiant difference from one side of the body to the other should not he greater then about 10 °C. 

Because of the importance of pH in regulating so many physiological processes, any changes in pH that occur as a result of changes in body temperature would seem likely to add another element of thermal stress to the system. Thus, one might predict a priori that the pH values of the blood (pHB) and the cytosol would need to be closely conserved in the face of changes in body (cell) temperature if homeostasis is to be... 

NNA is one of the most sensitive techniques available for determining trace elements. It irradiates the target material with a thermal neutron flux from a nuclear reactor. The elements in the sample absorb the neutrons and become artificial radionuclides whose spectrum is analysed in order to calculate the proportion of each element. The greatest asset of NNA is that the detection limit can be set at will by the analyst by regulating the neutron flux and irradiation time. One additional asset is that determinations are non-destructive and involve virtually no chemical separation. 

A power measurement is fed in the fuel flow regulator, whose output determines the position of a fuel valve. A step change in the input reactant element will not be noticed as a sudden increase in charges. Typically, there is a sudden but contained rise in output power that takes place in 1-3 s, while the newly desired output power level is reached limited until the SOFC reaches its thermal equilibrium, which may tens of seconds. This characteristic makes the SOFC a poor candidate for isolated systems, where loads require instantaneous power. 

The experimental set-up for studies of Kossel diagrams is depicted in Figures 2.18 and 2.19. The liquid crystal sample is contained in the space of thickness about 0.2 mm between a thin cover glass and a glass cylinder of diameter of 3 mm (Figure 2.18). The temperature of this cell is regulated by means of Peltier elements. This sample is in thermal contact through the... 

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