Spectrographic determination of impurities in ultrapure tungsten and tungsten oxide.
The effects of an external magnetic field and of the diameter of the anode on the spectroscopic line intensity of the impurity elements in ultrapure tungsten and tungsten oxide have been studied. The results obtained are used for the development of a more sensitive method for the determination of these impurities (Mn, Pb, Fe, Ni, Al, Mo, V, Cu, Cr).
The use of external magnetic fields in spectroscopic analysis of traces in DC arc
SummaryThe use of external magnetic fields leads to an increase of intensity of spectral lines of traces. This makes possible the elaboration of new methods for spectrochemical trace analysis. The intensification of lines is connected with the broad shape of the arc plasma and with the residence time of particles in it.ZusammenfassungDurch Anwendung von Fremdmagnetfeldern kann eine Intensitätserhöhung der Spektrallinien von Spurenelementen im Lichtbogen erreicht werden. Dadurch ergibt sich die Möglichkeit der Entwicklung neuer spektrochemischer Verfahren zur Spurenanalyse.Die Intensitätserhöhung der Spektrallinien steht im Zusammenhang mit der breiten Plasmaform und der längeren Verweilzeiten der Teilchen im Bogenplasma.
Cholesterol synthesis from acetate in the diabetic liver.
Brady and Gurin (1) recently compared the ability of liver slices prepaped from both normal and diabetic rats to incorporate added acetate into cholesterol. They drew the conclusion that the conversion of acetate to cholesterol in the diabetic liver is “apparently unimpaired, although this process may be inhibited when diabetes is sufficiently prolonged and severe.” In view of our interest in the relation of cholesterol synthesis to arteriosclerosis, the development of which is generally regarded as being accelerated in diabetes (2), we have reinvestigated cholesterol synthesis from acetate in diabetes. A definite increase in cholesterol formation in the diabetic liver is demonstrated here. It is further shown that, as a result of insulin injections in a diabetic rat, slices subsequently prepared from its liver have a reduced capacity to synthesize cholesterol.