Applying the present theory to this specimen, we have a total domain-wall area in the demagnetised condition of 6 x 0-07 = 0-42cm, 2 and, assuming as before l-5erg/cm 2 for the wall energy, the total wall energy for the specimen is 0-63 erg. In one complete cycle of magnetisation to saturation, this energy would be released twice, and therefore the hysteresis loss due to the domain walls should be 1 -26erg. It therefore appears that l-26erg is the minimum hysteresis loss per cycle for saturation that could be achieved for this specimen, no matter how well purified and heat-treated it might be.The hysteresis loop actually observed by Williams and Shockley is shown in Fig. 6b, with a coercive force of about 0 012Oe (0-96A/m). From the area of the loop and the volume of the specimen, a simple calculation gives the observed hysteresis loss per cycle as 2 • 6erg, compared with 1 *26erg calculated for the domain-wall loss. These estimates of loss are, however, obviously approximate, since some of the available quantities used in the calculations are given to one significant figure only.
A commercial 10-Mc digital chronometer has been used to measure time lags to breakdown in SF6/air mixtures. This method is much quicker than taking measurements from oscillograms and gives greater accuracy when a very wide range of time lags occurs for the same experimental condition. Precautionary measures against pickup from high voltage circuits are described, together with a method of producing pulses suitable for starting and stopping the chronometer.
We demonstrate the feasibility of quantifying the abundance of 2H in plasma by nuclear magnetic resonance (NMR) spectroscopy. After adding internal standard (tert-butyl-d9 alcohol) to deproteinized plasma samples containing 2H2O, we determined the ratio of NMR peak areas for 2H2O and tert-butyl-d9 alcohol. This peak-area ratio was directly proportional to the exogenous 2H enrichment of plasma (difference between measured and naturally occurring 2H) between 0 and 0.272 atom % (r = 0.999). The coefficient of variation was 1.34% at an exogenous enrichment of 0.136 atom %. We applied this method to a study of the dilution kinetics of 2H2O to determine the optimal time and method of blood sampling for estimation of total body water content. The 2H enrichment of plasma stabilized by 4 h after intravenous injection of 2H2O, 1 g/kg of body weight, and fluctuated within 2-4% of the 4- to 8-h mean thereafter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.