Overall effective conductance

Overall coefficients cannot be predicted directly from the physical properties and flow rates of a system but must be derived from the individual film coefficients. It is important therefore to be able to relate overall and film coefficients. This can be done if it is realized that the coefficients are in effect conductances. The diffusional resistance of the two films are equal to the reciprocals of the film coefficients, and... 

The assumption of local thermal equilibrium also means that an overall effective thermal conductivity is needed, because there is only a single energy equation. One way to calculate this thermal conductivity is to use Bruggeman factors. 

As discussed by Fuchs and Sutugin (1970, 1971) and Motz and Wise (1960), in this continuous regime, distortion of the Boltzmann velocity distribution in the region close to the surface occurs if there is rapid uptake. In effect, the normal thermal velocity distribution is distorted so that the effective speed toward the surface is higher. In the case of a surface where the uptake occurs on every collision, the net speed toward the surface is effectively doubled. This adds an additional term to the rate of transfer of the gas to the surface, which when normalized using Eq. (PP), gives an additional resistance term of -1 /2. The overall normalized conductance is therefore given by... 

In order to obtain a more intuitive insight into the mechanism of thermodynamic buffering we calculated the effects of thermodynamic buffering on the entropy production of the system. The entropy production of oxidative phosphorylation with an attached load is given in equation (8). A convenient way to introduce the contribution of the adenylate kinase reaction to this system is to consider L/ as an overall load conductance embracing the effects of the adenylate kinase reaction as well as the effects of the true extrinsic load conductance of the irreversible ATP utilizing... 

As sintering proceeds and coalescence and densification occur, the overall heat conduction problem does not remain unaffected. Clearly, the effective thermophysical properties change, thereby influencing the overall temperature distribution and the local sintering problem as well. 

Some individual trials of antidepressants that found no overall effects, found a relatively stronger effect in some of the most severely depressed subjects in post hoc analysis (Elkin et al. 1989 Paykel et al. 1988). However post hoc analysis is where the authors look for significant results without predetermining what particular tests are of interest. This sort of analysis is commonly referred to as a fishing expedition and it is well known that it can highlight results that are positive just by chance. Another similar trial conducted in primary care found no association between melancholic depression, that is the most severe depression, and antidepressant efficacy (Malt et al. 1999). These trials were conducted exclusively with people with relatively mild depression and so could not assess the relation over the whole severity range. The meta-analyses too were based mostly on outpatient studies. On the... 

The properties which determine heat transfer through a deposit layer of given thickness are thermal conductivity, emissivity, and absorptivity. These properties vary with deposit temperature, thermal history, and chemical composition. Parametric studies and calculations for existing boilers were carried out to show the sensitivity of overall furnace performance, local temperature, and heat flux distributions to these properties in large p.f. fired furnaces. The property values used cover the range of recent experimental studies. Calculations for actual boilers were carried out with a comprehensive 3-D Monte Carlo type heat transfer model. Some predictions are compared to full-scale boiler measurements. The calculations show that the effective conduction coefficient (k/As)eff of wall deposits strongly influences furnace exit temperatures. 

The design of TBCs for the use in temperature gradients has to take into account the change of overall thermal conductivity by the grading function. The effective thermal resistivity offers possibilities to calculate coating thicknesses of same heatflux. 

Solvent Effects. The overall effect of solvent on the conductivity of (C6H5)2CHLi-(TMED)2 is shown in Figure 1. As the number of methyl groups around the benzene ring increases, conductivity decreases. The... 

Provided the overall pressure drop is not too great, the treatment given above for liquids may be transferred to gases, with the inlet specific volume replaced by the isentropic average specific volume over the line as a whole, Va e, as given by equation (18.6), and the line conductances, C, replaced by the effective conductances, bojCj. As a result the overall flow... 

Non-paired Fe cations do not participate in the exchange process and thereby tend to contribute to the A site (Fe " ") components of the spectrum. An external magnetic field causes broadening of this component because the spin alignment remains antiparallel. The localised nature of the exchange process accounts for the observed drastic decrease in conductivity with increasing nonstoichiometry, although in a perfect stoichiometric lattice the overall effect can become one of delocalisation. 

The effective conductivity seems to follow the overall fracture transmissivity reduction. Figure 7 shows changes in effective conductivity, average fracture transmissivity change (disregarding orientations for fracture sets) and a fitted trend. 

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