Transition energy pressure

Although there have been few data collected, postshock temperatures are very sensitive to the models which specify y and its volume dependence, in the case of the Gruneisen equation of state (Boslough, 1988 Raikes and Ahrens, 1979a Raikes and Ahrens, 1979b). In contrast, the absolute values of shock temperatures are sensitive to the phase transition energy Ejp of Eq. (4.55), whereas the slope of the versus pressure curve is sensitive to the specific heat (see, e.g.. Fig. 4.28). 

The preceding calculations can also be performed for finite cavity sizes. For this case, there are some additional sources of small amounts of energy associated with cavity formation arising from surface tension, pressure-volume work, and electrostriction. Because of the Franck-Condon principle these do not affect the transition energy, but they have some influence on the heat of solvation. Jortner s (1964) results are summarized as follows ... 

In several cases—such as, for example, phthalocyanine and protoporphyrin IX derivatives— the energy red shift and broadening of the transition with pressure may be sufficient to ensure a thermal population of the excited state, by occupation of a ti orbital. As discussed above, the thermal occupation of excited states may lead in principle to the formation of a reaction product. 

Figure 33. Pressure dependence of the electronic transition energies of [Cu(dieten)2](BF4)2 polycrystalline (left panel) and in polyvinyl pyridine matrix (right panel).

Solvatochromic shift data have been obtained for phenol blue in supercritical fluid carbon dioxide both with and without a co-solvent over a wide range in temperature and pressure. At 45°C, SF CO2 must be compressed to a pressure of over 2 kbar in order to obtain a transition energy, E, and likewise a polarizability per unit volume which is comparable to that of liquid n-hexane. The E,j, data can be used to predict that the solvent effect on rate constants of certain reactions is extremely pronounced in the near critical region where the magnitude of the activation volume approaches several liters/mole. 

Solvatochromic data, specifically absorption or transition energies (E s), have been obtained for the dye phenol blue in supercritical fluids as a function of both temperature and pressure. These data will be used to compare the "solvent strength" of these fluids with liquid solvents. He will use the terms "solvent strength" and "Et" synonymously in this paper such that they include the magnitude of the polarizability/volume as well as the dipole moment. The "solvent strength" has been characterized by the spectroscopic solvatochromic parameter, E, for numerous liquid solvents (9 JU, J7,JJ3). 

The planned measurements will be able to accumulate an intensity of more than 10000 events per transition enabling a determination of the transition energy with a statistical accuracy of better than 3 meV. For the 3-1 and 4-1 transitions in pionic hydrogen pionic oxygen and carbon transitions adjacent in energy are available as calibration lines, thus avoiding the systematic errors in the former experiment. In a first step the experiment will establish a result for the shift independent of pressure. In order to achieve this the position of the 3-1 and 4-1 lines will be measured as a function of pressure in the region between... 

From the effects of quasihydrostatic pressure on the transition energy of the 77.3 keV gamma rays of Au in metallic gold, a value of A(r >= +9X10" has been derived for the change of the mean-squared nuclear charge radius. The positive sign of implies an increase in p(0) with increas-... 

Our problem was now that when QED corrections were added the agreement was reduced. However, an experimental pressure dependence of the measured transition wave lengths was found[35] which increases the uncertainty of the experimental data. Our theoretical transition energies do thus appear to be within the current experimental errorbars. The calculated radiative decay rates agree well with experimental work[5]. 

Fig. 3.43 Elements with Mossbauer isotopes are untinted. The energies are transition energies (for high-pressure candidates). Isotopes that have been used in high-pressure experiments are framed by bold lines.

Figure 5 Pressure dependence of the excitronic transition energies for the first singlet state of anthracene...

Repeated impulses generate more PD waves, and this leads to repeated accelerations of pore throat liquid as the waves transit. Sudden pressure pulses are the most effective way to generate the impulse, but a blow to the solid skeleton that has the right frequency content will generate the PD wave because of coupling however, if high frequencies are used (e.g. seismic frequencies of lO-KXX) Hz), very little energy will be converted to PD waves. 

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