Enhanced transient effects

Figure 3.30 Overlaid plots of the Si" and 0 secondary ion intensities during the initial stages of sputter depth profiling of Silicon with 1-keV Cs ions (constant current) at the listed angles. Note The enhanced transient effect extends to a depth of 40 nm. Author s...

Enhanced transient effects Additional transient effects noted during the onset of sputter depth profihng... 

Among NMR methods providing insight into radical ions, chemically induced dynamic nuclear polarization (CIDNP) has proved especially useful it results in enhanced transient signals, in absorption or emission CIDNP effects were first reported in 1967 their application was soon extended to radical ions. The method lends itself to modest time resolution. 

Rapid injection of nndilnted miconazole may produce transient tachycardia or arrhythmia. Miconazole and amphotericin B are antagonistic both in vitro and in vivo. The antifnngal activity of the two drngs, when nsed in combination, is less than that of either drng nsed alone. Miconazole enhances the effectiveness of anticoagnlants and increases the sernm level of phenytoin. It has caused rash, pruritis, and phlebitis at the site of infnsion. A transient decrease in hematocrit has been noted. 

Presence of a close contact between the Pt and Ce02 appears a fundamental requirement for the occurrence of the active state. Consistently, a decrease of the particle size of the Ce02 supported on A1203 increases the efficiency in the improvement of the catalytic activity by the reduction treatment. These transient enhancements of the catalytic activity were attributed to the presence of a SMSI state induced by the reduction, which creates some highly active NM-Ce02 interfacial sites (Golunski et al. 1995). In our view, the decrease of H2 chemisorption alone is not sufficient to attribute this transient effect to a SMSI-type phenomenon. As discussed above, the onset of metal decoration requires reduction temperatures higher than 773 K. 

The drug exerts its action by causing relaxation of the hypertonic (i.e., in a state of greater than normal tension) muscles minimise the response to the sensory stimuli, and also causes a significant depression of the superficial reflexes. Its weak activity and transient effect are on account of the facile metabolism of the primary hydroxyl function. In has been observed that the carbamylation of the said moiety enhances its activity. Importantly, the /)ara-chlorination affords an appreciable increase in the prevailing lipid-water partition coefficient and helps in blocking the />ara-position from undergoing hydroxylation as far as possible. 

X 107 cells tumor regression, no metastases 2 X 106 cells transient effect 1 X 108 cells enhanced tumor growth... 

The catalytic properties of the shock-modified rutile whose defect properties have been reported in previous sections of this chapter have been studied in a flow reactor used to measure the oxidation of CO by Williams and coworkers [82G01, 86L01]. As shown in Fig. 7.7 the effect of shock activation is substantial. Whereas the unshocked material displays such low activity that an effect could only be observed at the elevated temperature of 400 °C, the shock-modified powder shows substantially enhanced catalytic activity with the extent of the effect depending on the shock pressure. After a short-time transient is annealed out, the activity is persistent for about 8 h. Although the source of the surface defects that cause the activity is not identified, the known annealing behavior of the point defects indicates that they are not responsible for the effect. 

Luciferase-catalyzed luminescence of luciferin. Odontosyllis luciferin emits light in the presence of Mg2+, molecular oxygen and luciferase. The relationship between the luminescence intensity and the pH of the medium shows a broad optimum (Fig. 7.2.8). The luminescence reaction requires a divalent alkaline earth ion, of which Mg2+ is most effective (optimum concentration 30 mM). Monovalent cations such as Na+, K+, and NH have little effect, and many heavy metal ions, such as Hg2+, Cu2+, Co2+ and Zn2+, are generally inhibitory. The activity of crude preparations of luciferase progressively decreases by repeated dialysis and also by concentrating the solutions under reduced pressure. However, the decreased luciferase activity can be completely restored to the original activity by the addition of 1 mM HCN (added as KCN). The relationship between the concentration of HCN and the luciferase activity is shown in Fig. 7.2.9. Low concentrations of h and K3Fe(CN)6 also enhance luminescence, but their effects are only transient. 

Clearly, if a situation were achieved such that exceeded Np, the excess energy could be absorbed by the rf field and this would appear as an emission signal in the n.m.r. spectrum. On the other hand, if Np could be made to exceed by more than the Boltzmann factor, then enhanced absorption would be observed. N.m.r. spectra showing such effects are referred to as polarized spectra because they arise from polarization of nuclear spins. The effects are transient because, once the perturbing influence which gives rise to the non-Boltzmann distribution (and which can be either physical or chemical) ceases, the thermal equilibrium distribution of nuclear spin states is re-established within a few seconds. 

Cavitations generate several effects. On one hand, both stable and transient cavitations generate turbulence and liquid circulation - acoustic streaming - in the proximity of the microbubble. This phenomenon enhances mass and heat transfer and improves (micro)mixing as well. In membrane systems, increase of fiux through the membrane and reduction of fouling has been observed [56]. 

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