Synthesis and ion-exchange properties of zirconium molybdoarsenate (ZrMAs)

Zirconium molybdoarsenate (ZrMAs), an inorganic ion exchanger, has been synthesized and the suitable conditions to separate cesium-137 from fission products waste solution are suggested.     

Aberration-corrected catadioptric magnifiers useful for simple microfiche readers

The present paper considers the magnifying power and aberration properties of three different catadioptric magnifying systems useful for application as simple hand-held microfiche readers. These are in the form of a plano-convex lens, a meniscus lens and an achromatic doublet lens and all their outer surfaces have been coated with a semi-reflecting film so that they behave like catadioptric elements. These can be designed to give magnification in the range of 15 × to 25 × with sufficient eye relief. Using such magnifiers, it is possible to read microfiche having frame sizes of 16 × 12 mm and 12 × 9 mm. The cemented achromatic doublet coated on the outer surfaces seems to give a very good image for use in microfiche reader.     

Determination of trace elements in rocks by optical emission spectroscopy: A new method of internal standardization

Summary A method has been described for the determination of twelve trace elements (Pb, Sn, Cr, Co, Ni, V, Y, La, Zr, Cu, Zn, Sc) in different types of rocks using optical emission Spectroscopy (OES). The method employs a single set of synthetic standards for analysing any type of rock, basic, acidic or intermediate. When an external element, such as osmium, has been added to serve as internal standard, the analytical data showed poor precision. A new method of internal standardization has, therefore, been attempted. In this, a line due to silicon whose intensity is influenced by two adjacent Fe lines, has been used as the internal standard. Such an approach gave better presision (expressed in terms of coefficient of variation). Six international rock standards have been analysed and the data obtained have been compared with that previously reported.

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Bestimmung von Spurenelementen in Gesteinen durch optische Emissions-Spektroskopie: Ein neues Verfahren zur inneren Eichung

Zusammenfassung Zwölf Spurenelemente (Pb, Sn, Cr, Co, Ni, V, Y, La, Zr, Cu, Zn, Sc) werden in verschiedenen Gesteinstypen bestimmt. Basische, saure und intermediäre Gesteine können mit einem einzigen Satz synthetischen Standards analysiert werden. Bei Benutzung eines externen Elements (Os) zur Eichung wurden schlechte Ergebnisse erhalten. Bei dem neuen Verfahren wird eine bessere Reproduzierbarkeit (ausgedrückt als Variationskoeffizient) durch Verwendung einer Siliciumlinie, die durch benachbarte Eisenlinien beeinflußt wird, erzielt. Sechs internationale Standardgesteinsproben wurden nach diesem Verfahren untersucht und die Ergebnisse mit früher erhaltenen verglichen.

     

Flow past a continuously moving flat plate in transverse magnetic field

The analysis of flow past a continuously moving semi-infinite flat plate in the presence of transverse magnetic field has been presented. Model solutions have been derived and the resulting equations are integrated numerically. Velocity profiles are displayed graphically and the numerical values of the transverse velocity skin friction are given in the form of tables. It has been observed that an increase inM (magnetic field parameter) leads to a decrease in velocity.The author wishes to express his thanks to Dr. H. N. Siddiquie, Director, and Dr. J. S. Sastry, Head, Physical Oceanography Division, for their keen interest and encouragement throughout this work.     

Theoretical study of14N pure quadrupole resonance in amino acids

The theoretical hybridization model of Vega is adapted to the tetrahedral environment around the nitrogen nucleus in eleven amino acids to estimate the orbital occupation numbers using the experimental values of the quadrupole coupling constant and asymmetry parameter of¹⁴N quadrupole resonance and the results are discussed.     

Ramanujan — Fourier series and a theorem of Ingham

Given two arithmetical functions f, g, we derive, under suitable conditions, asymptotic formulas for the convolution sums ∑ _n≤N f (n) _g (n + h) for a fixed number h. To this end, we develop the theory of Ramanujan expansions for arithmetical functions. Our results give new proofs of some old results of Ingham proved by him in 1927 using different techniques.     

Heat transfer in flow past a continuously moving semi-infinite flat plate in transverse magnetic field with heat flux

Thermal boundary layer on a continuously moving semi-infinite flat plate in the presence of transverse magnetic field with heat flux has been examined. Similarity solutions have been derived and the resulting equations are integrated numerically. This investigation has indicated a fall in the temperature of the thermal boundary layer with increase in magnetic field parameter.

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Wärmeübertragung in Strömungen an einer gleichmäßig bewegten, halbunendlichen ebenen Platte in einem quergerichteten Magnetfeld mit Wärmefluß

Zusammenfassung Es ist die thermische Grenzschicht auf einer gleichmäßig bewegten, halbunendlichen ebenen Platte in einem quergerichteten Magnetfeld mit Wärmefluß untersucht worden. Ähnlichkeitslösungen sind abgeleitet und die erhaltenen Gleichungen numerisch integriert worden. Diese Untersuchung hat einen Rückgang der Temperatur in der thermischen Grenzschicht mit steigendem Magnetfeldparameter nachgewiesen.