Measured induction periods changes

Local anesthetics interact with peripheral nerve cell membranes and exert a pharmacological effect [34]. Potential oscillation was measured in the presence of 20 mM hydrochlorides of procaine, lidocaine, tetracaine, and dibucaine (structures shown in Fig. 16) [19]. Amplitude and the oscillatory and induction periods changed, the extent depending on the... 

In this study, potential oscillation was measured in the presence of lOOmM sodium salts of barbital, allobarbital, phenobarbital, and amobarbital in phase wl [19]. Their chemical structures are shown in Fig. 15. Amplitude and the oscillatory and induction periods were noted to depend on the particular hypnotic used. Amplitude decreased in the order, barbital > allobarbital > phenobarbital > amobarbital. The oscillatory period increased in the order, barbital < allobarbital < phenobarbital < amobarbital. Induction period increased in the order, barbital < allobarbital < phenobarbital < amobarbital. These parameters changed depending on drug concentration. Hypnotics at less than 5 mM had virtually no effect on the oscillation mode. 

The concept of a measurement of an induction period is based upon determination of critical time of the reaction progress that leads to the catastrophic change of the useful properties of the material. This may be demonstrated on the... 

It has been shown above that during the induction period no change occurs in DSC, macroscopic density, and WAXD. Does nothing change in this period In order to answer this question, we made real-time SAXS measurements. 

Further proof for the fact that these induction periods are caused by slow hydrogenation of the diene ligand was obtained by NMR-spectroscopic measurements under hydrogenation conditions [10f, 15]. The registration of 31P- and 1H-spectra allows the simultaneous monitoring of changes in the bisphosphine complexes and substrate conversion. The results of the hydrogenation of methyl-... 

In many practical systems, one cannot distinguish the two stages in the ignition process since To> t, thus the time that one measures is predominantly the chemical induction period. Any errors in correlating experimental ignition data in this low-temperature regime are due to small changes in rt. 

The effects of slow neutron irradiation caused color changes and darkening in most of the expl crystals, indicating the formation of F centers and nuclei, and subsequently affected the thermal decompns of the expls. The rates of thermal decompn as measured by pressuretime curves for irradiated Pb azide are shown in Fig 2. With Li azide the effect of pre-irradiation with slow neutrons is to cut down the induction period to about one-half and to increase the rate of decompn considerably... 

Figure 5.9B shows the infiuence of US intensity over the range 2.5 to 3.4 W/cm as measured after 30 min of cross-fiow fiitration in order to surpass the longest induction period (28 min at 45 kHz). At 100 kHz, the permeate flow of the dextran solution did not change with the US intensity and was virtually identical with that observed in the absence of US. At 28 and 45 kHz, however, the US intensity clearly influenced the results. 

Methanol is somewhat less reactive than its higher homologues and slow combustion takes place at a conveniently measurable rate only above 390 °C. In uncoated pyrex vessels [7], or vessels coated with boric acid or potassium chloride [8], reaction begins immediately without a true induction period and accelerates to a maximum rate. This maximum is increased by the addition of inert gas and is proportional to the square of the initial methanol concentration, (in boric acid coated vessels this power is about 2.5) but independent of oxygen concentration over a wide range of conditions. The overall activation energy (calculated from the effect of temperature on the maximum rate of pressure change) is about 40 kcal.mole" in coated vessels and about 53—61 kcal.mole in uncoated ones. 

Detailed chemical analysis [43(a)] showed that pressure change was a valid measure of reactant consumption, and further that at 250 °C the reaction in the early stages following the induction period could be represented by... 

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