Small-scale temperature fluctuation

Baish, J.W., PS. Ayyaswamy, and K.R. Foster, Small-scale temperature fluctuations in perfused tissue during local hyperthermia. J. Biomech. Eng., 1986,108 246-250. 

However, the susceptibility becomes spatially dependent and thus finite at qy>. This means that at small scales the fluctuations are suppressed and the thermodynamic properties are controlled by the instrumental scale L = q. When the correlation length considerably exceeds L, is replaced by L. Figure 7.12 shows the osmotic susceptibility of polystyrene-cyclohexane solutions obtained for various temperatures, and two length scales... 

The velocity relaxation time is m/ (and this is mD/kB T 0.01— 0.1 ps at room temperature for small molecules). It is much longer than the time scale of fluctuations of the force f(t). The time average of f(f ) in the integral above is zero. Taking the average over the ensemble gives... 

The small thermal length scale involved in the microvasculature. Thermally significant blood vessels are generally in a thermal scale of less than 300 fan. It has been difficult to build temperature-measuring devices with sufficient resolution to measure temperature fluctuation. 

In contrast, high temperature fuel eells like SOFCs provide efficient power generation with power to heat ratios > 1 even at small scale. In addition, they are able to process lean biogases and fluctuating gas composition. If the remaining development tasks will be addressed with sufficient resources, this technology can considerably improve electrical power production from biogas in the near future. 

Refractive index detectors also have several applications in lipid analysis. They are "universal" detectors, but lack sensitivity, require isocratic elution conditions and are sensitive to minor fluctuations in temperature. Their main value is probably in small-scale preparative applications, say with 1-2 mg of a lipid extract. For example, a refractive index detector was utilized with a column (4.6 x 250 mm) of Ultrasil Si (5 micron silica gel) and isocratic elution with isooctane-tetrahydrofuran-formic acid (90 10 0.5 by volume) to separate most of the common simple lipid classes encountered in animal tissue extracts, such as those of liver [304]. Cholesterol esters, triacylglycerols and cholesterol were each resolved and gave symmetrical peaks. 

Because the time scale of the anticipated atmospheric motion associated with the temperature fluctuations is only one day, the thermal wind approximation caimot be used. However, diurnal variations in the pressure and wind fields can be estimated from the observed temperature field using classical tidal theory. The basic concept of the formulation is sketched here a detailed treatment can be found in Chapman Lindzen (1970). The theory is based on a linearization of the primative equations. A motionless atmospheric reference state is assumed with temperature profile To z) and a corresponding geopotential surface 4>o(z). It is further assumed that the diabatic heating and all other quantities vary as exp[i(j < — cot)] where s is a longitudinal wavenumber and co is 2 7r/(solar day) or integer multiples thereof. The amplitudes of the time-varying, dependent variables are taken to be sufficiently small so that only terms of first order need be retained. With these assumptions. 

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