Phase temperature shifts

S. Yu and A.M. Weiner, Phase-matching temperature shifts in blue generation by frequency doubling of femtosecond pulses in KNb03, Journal of the Optical Society of Americas 16(8), 1300-1304 (1999). 

Solvents from which the solute could be stripped back into an aqueous phase, perhaps utilizing a temperature shift or a chemical reaction. 

On the basis of the calibration by melting points and phase transitions, a number of shift thermometers have been developed for solid-state NMR spectroscopy in various temperature ranges. Wehrle et al. 144), for example, used the line splitting in the N CP/MAS NMR spectrum of the organic dye molecule tetra-methyldibenzotetraaza annulene (TTAA) in the temperature range 123—405 K. A high-temperature shift thermometer for temperatures of up to 790 K was developed by van Moorsel et al. 40) on the basis of Sn MAS NMR spectroscopic... 

The phase separation temperature shift by photo-isomerization implies that in the temperature range between 19.4 and 26.0 °C, ultraviolet irradiation solubilizes the polymer or expands the polymer chain, while visible irradiation decreases the solubility, or shrinks the chain. Figure 3 shows the photo-stimulated phase separation at 19.5 °C accompanied by the conformation change of the polymer chain. Upon exposure to UV light (350 <%< 410 nm), the opaque solution became transparent, while visible irradiation (>. > 470 nm) again decreased the transmittance of the solution. The polymer chain conformation changed concomitantly with the phase separation. 

Optimizing the value of k, or more importantly (k + 1) is important for the analysis of volatile compounds such as those in aroma samples. The value of k is strongly dependent upon temperature and the phase ratio (B) of the column. From Equation 3 it is apparent that decreasing temperature shifts the equilibrium constant Kjj, and therefore k increases. When k is a small number (i.e. <2), which is often the case with volatile compounds, resolution increases greatly with only small increases of k. 

Typically, the process is set to control temperature to a value that results in high cell growth or production rate. Sometimes, however, a different temperature may be selected, which could result in a better quality product or a respiration rate compatible with the oxygen transfer system (Chuppa et al., 1996). For some processes, a temperature shift batch culture may be desirable in which there are two controlled temperature values, one for the growth phase and another for the production phase, in which the cell division is interrupted due to the low temperature (Fox et al., 2004). 

The particulate catalyst is composed of 90% Fe and 10% Cr. The Cr minimizes sintering of the active Fe phase. The catalytic reaction is limited by pore diffusion so small particles are used. The exit process gas contains about 2% CO as governed by the thermodynamics and kinetics of the reaction. This reaction is slightly exothermic and thermodynamics favor low temperatures that decrease the reaction rate. It is therefore necessary to further cool the mix to about 200°C where it is fed to a low-temperature shift reactor (LTS)... 

For this purpose, the dynamic mechanical properties of a series of 25/75 in situ SIM IPNs have been investigated (Figure 5). With 1% OcSn, the tan 8 vs temperature curve shows a classical shape, as for in situ SEQ IPNs and corroborates the kinetic results two separated transitions, broadened and damped, exist (10). The lower transition corresponding to the polyurethane phase, is shifted... 

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