The determination of glycerol : Absorptiometric determination as the copper complex

Spectrophotometric studies of the copper-glycerol complex are reported. A single 1 : l complex is formed under the experimental conditions employed. The interference of precipitated or colloidal copper(II) hydroxide can be overcome by filtration through glass-fibre discs or by application of a correction factor. Filtered solutions of the complex in 90% ethanol obey Beer's law over a wide range of concentration. The stability of the complex and the effects of variation in alcohol and alkali concentration have been studied.An absorptiometric method for the determination of 0.5–40 mg of glycerol is proposed and the effect of possible interferences is considered.     

The polarographic behaviour of some elements in concentrated calcium chloride solution: The determination of chromium in the presence of nickel

Further studies on the polarography of trivalent chromium in concentrated calcium chloride solution are described. Details are given of a chloride-hydroxylamine base electrolyte (7.4M with respect to chloride) in which chromium may be determined directly in the presence of nickel. This method is not applicable if the nickel-chromium ratio is large. Results are presented and certain theoretical aspects are discussed.     

On the dynamics of turbulent vortical flow

Zusammenfassung Die Wirbelströmung in einer turbulenten kompressiblen Flüssigkeit wird behandelt. Die Bewegungsgleichungen werden durch die Vernachlässigung der kleineren Glieder vereinfacht. Die experimentellen Ergebnisse erlauben eine Fehlerrechnung für einen Fall. Ein wichtiger Schritt in der Vereinfachung ist die Voraussetzung, dass die Radialgradienten viel grösser sind als die Axialgradienten. Für die kräftigen Wirbel erwies sich diese Annahme sowohl durch die Erfahrung als auch aus den wesentlichen theoretischen Betrachtungen heraus als begründet. Die vereinfachten Gleichungen zeigen einige wichtige Aspekte der schnelldrehenden Strömungen und geben einen Anhaltspunkt für die ausführlicheren Studien.

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Notation r radial co-ordinate - z axial co-ordinate - u, U, u radial velocity component, its time-mean value, and the turbulent perturbation to it - v, V, v tangential or swirl velocity component, etc. - w, W, w axial velocity component, etc. - p, P, p fluid pressure, etc. - ,R, fluid density, etc. - , , , numbers small with respect to unity - C, F, G, G ₀ constants of integration     

Water-soluble coumarin dyes for flashlamp-pumped dye lasers

New coumarin derivatives have been prepared that are soluble in water, a solvent with superior thermo-optical properties. The new dyes, flashlamp-pumped, lase with high effeciency between 450 and 520 nm (untuned).     

Trimethine pyrylium dyes

The synthesis and electronic absorption spectra of some pyranylidene trimethine pyrylium salts are described.