Differences in temperature dependence

Because of the significant differences in temperature dependence the kinetically limited reactions can be distinguished from pore diffusion that in turn can be differentiated from bulk mass transfer. This is shown in Fig. 7.2 in... 

B Transitions and band profiles associated with type 3 copper. Note the difference in temperature dependence of the MCD signal as described in the text. 

Based on the above interpretation, the main effect of increased catalyst concentration 1s to produce more diffuse boundaries between the hard and the soft domains, since differences in T c among the samples are small, while differences in temperature dependency of the modulus are large as Indicated by Figure 6. It is interesting to observe in this figure also that all curves converge to a limiting modulus ratio value of about 3.0, G,(-30°C)/G,(70°C). 

FIGURE 12.4 The solubilities of KNO3 and NaCI at 0°C and 60°C. The difference in temperature dependence enables us to isolate one of these compounds from a solution containing both of them by fractional crystallization. 

K, compare stochastic and deterministic formulas (6-13) and (6-15) for the probability of the adiabatic channel of reaction (6-2) limiting the Zeldovich mechanism of NO synthesis in plasma. Explain the difference in temperature dependences of the probabilities for the stochastic and deterministic approaches. 

Hence, extrapolating to 100 C, the refractive index would be about 1.375 which is a sizable change in refractive Index units. Although the refractive indicies may be matched at room temperature, at elevated temperature there develops a mismatch and consequently there is an increase in haze. The new silica filler compositions show some temperature dependent haze, however not to as great an extent as compositions which depend upon matched refractive indices to achieve optical clarity. Table IX shows these differences in temperature dependent haze. For applications which require optical transparency over a range of temperatures, the new silica filled compositions offer a distinct advantage. 

Another technique related to DSC is DTA, differential thermal analysis. In this method sample and reference are heated by a single source and temperatures are measured by thermocouples embedded in the sample and reference or attached to their pans. Because heat is now supplied to the two holders at the same rate, a difference in temperature between the sample and the reference develops, which is recorded by the instrument. The difference in temperature depends, among other things, on the value of K, which needs to be low to obtain large enough differences in temperature to measure accurately. The area under a transition peak now depends on k and it is difficult to determine this accurately or to maintain it at a constant... 

FIGURE 6.8 Local segmental relaxation times (circles) and terminal shift factors (squares) for polybutadienes. The fitted VFTH equations illustrate the marked differences in temperature-dependence of the local and global dynamics (Robertson and Rademacher, 2004). 

Figure 9.9 Graph of the temperature dependence of the solubilities of KNO3 and NaCl in water. KNO3 is considerably more soluble at high temperatures (that is, 60°C) than at low temperatnres (that is, 0°C), whereas the solnbUity of NaCl increases only slightly as the temperatnre increases. The difference in temperature dependence makes it possible to isolate pnre KNO3 from a solution containing both salts via fractional crystallization.

In the case of the crystallization of low molecular mass materials at temperatures above TV, the growth is proportional to AT, whereas experiments on crystal growth in the case of polymers indicate that the growth rate is proportional to IjTciAT. Sadler " suggested that the difference in temperature dependence above 7 was of an entropic origin. In colloid science entropic barriers as a... 

Gorenstein A priori it is not possible to say that a trianionic phosphate is a much better reference standard than a simple monoanionic diester since we know so little about intrinsic temperature dependencies to chemical shifts. Hydrogen-bonding interactions to solvent and electrostatic effects to counter-ions may be quite different between the two types of phosphates and thus 1 am not sure that one "standard" is necessarily better than another. Uhat is important is the relative difference in temperature dependency to P-31 shifts between any reasonable simple model and the nucleic acids. Ue will though investigate your suggestion. Note that our choice of lock standards (P2O or C5F5) also exerts an influence on these measurements (see discussion in ref. 8). 

Along with the surface area alteration possibility, a significant effect can also be brought by noticeable differences in temperature dependencies of thermal capacities of solid and hquid phases. As it is illustrated in Fig. 4, where nickel is used as an example, ACp of phase transition is less if it occurs at some temperature Ti lower than Ttemperature dependence ACp and AH(T) of phase transition. 

The difference in temperature dependence between both class of monomers could be explained in terms of mechanism of polymerization as shown in chapter 4. 

Figure 10.3 Viscosities of a variety of glass-forming systems as a function of reduced reciprocal temperature (Kelvin) Tg/r, where 7g is defined as the temperature when the viscosity t = 10 Pas. The difference in temperature-dependent behaviour between strong and fragile glass-forming liquids is clear (8).

In SPS process, grain growth is suppressed by rapid heating and the densification is accelerated at high temperamre. UHTCs densified by spark plasma sintering usually have higher densities, refined microstructures, clean grain boundaries as well as an overall improvement in the materials performance. In SPS, the temperature measured on the die surface is lower than the actual sample. The difference in temperature depends on the size of the die, level of vacuum and insulation. 

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