Spatially homogeneous and anisotropic cosmological solution in Brans-Dicke theory

An exact solution of the vacuum Brans-Dicke (BD) field equations has been obtained for the metric tensor of a spatially homogeneous and anisotropic Bianchi type-I cosmological model. The Kasner metric is shown to be a special case. Some physical properties of the model have been discussed.     

The C2II-X2Σ system of SrF molecule

The spectrum of the C²II-X² Σ system of SrF molecule has been investigated under high resolution. The rotational structure in the (0, 0) band has been analysed and the rotational constants for the C²II state have been obtained. The vibrational analysis of this system has been carried out using the band heads from the high resolution spectrogram and also the band origins and the precise vibrational constants have been reported for both the participating states.     

Lattice vibrations and specific heat of zinc blende

The dispersion relations, frequency distribution function and specific heat of zinc blende have been calculated usingHouston's method on (1) A short range force (S. R.) model of the type employed in diamond bySmith and (2) A long range model assuming an effective charge Ze on the ions. Since the elastic constant data on ZnS are not in agreement with one another the following values were used in these calculations:

$$C_{11} = 10.78; C_{12} = 6.87 and C_{44} = 3.87 in 10^{11} dynes/cm^2 $$     

An auxiliary table for concentration calculations in atomic-absorption flame photometry

A table has been prepared for atomic-absorption work which gives concentrations in ppm and percent of analyte in original sample for a given series of standards as a function of the dilution ratio used during the steps of sample preparation. The use of original concentrations simplifies the calculation of concentration in manual graphical interpolation and allows the operator the use of simple interpolation computer programs, if desired, without the need of introducing constant or variable conversion factors. The table covers the most frequent concentration ranges of minor and micro components and dilution ratios from 1:10 to 1:10000.     

Stereospecific synthesis and antibiotic activity of some cephalosporin analogs

The strategy used for the stereospecific synthesis of benzofused octams as cepham analogs was the conversion of a 3,4-dihydrothioisocarbostyril to a thioimidate, cycloaddition reaction to form a fused β-lactam and subsequent removal of the alkylthio group by Raney nickel hydrogenolysis. Using azidoacetyl chloride for forming the β-lactam and following known procedures, an amido side chain was generated. Two of the carba analogs of cephalosporin so produced showed low levels of antibacterial activity against a number of gram positive and gram negative organisms.     

The growth and decay of sonic waves in a radiating gas at high temperature

The propagation of a sonic discontinuity in an optically thick gray gas at temperature 10⁵°K or higher has been studied. The effects of radiation pressure and radiation energy density have been taken into account, while the profiles structured by radiant heat transfer are imbedded in the discontinuities under high temperature conditions of an optically thick medium. When the sonic discontinuity is propagating into a gas at rest, its velocity of propagation is found to be a constant which is the effective speed of sound in a radiating gas. The fundamental differential equations governing the growth of the sonic discontinuity are obtained and solved. It is concluded that if the sonic discontinuity is a compressive wave of order 1, then it terminates into a shock wave after a critical timet _c which has been determined. But on the other hand, when the sonic discontinuity is an expansion wave of order 1, then it will decay and will vanish ultimately. Particular cases of interest have been studied in details.     

Differentiation of phase objects by spatial filtering

A filter function has been theoretically arrived at, which in a coherent optical system produces an irradiance image distribution that is quasi-linear to the first derivative of the phase of a purely phase varying object. The filter function is generated with the aid of a computer-controlled plotter and experimental results of phase differentiation are presented.     

Furanverbindungen, 7. Mitt.: Synthese linear anellierter Furoxanthone

Zusammenfassung Die bemerkenswerte photodynamische Wirkung linear anellierter Furobenzopyrone (Psoralen, Methylpsoralen und Khellin) wird zum Anlaß für die Synthese von Xanthonanalogen des 8-Methylpsoralens, wie z. B. des 2,11-Dimethyl- oder des 2,7,11-Trimethyl-5-oxo-5H-furo[3,2-b]xanthens genommen.

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The appreciable photodynamic activity of linear furanobenzopyrones (psoralen, methyl psoralen and khellin) is discussed. The synthesis of xanthone analogues of 8-methylpsoralen viz. 2,11-dimethyl- or 2,7,11-trimethyl-5-oxo-5H-furo[3,2-b]xanthenes is recorded.

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Teilveröffentlichung der vonY. S. Agasimundin eingereichten Dissertation zur Erlangung eines Dr. phil. der Karnatak University.     

Applications de la photométrie de flamme à l'analyse des éléments différents aux alcalins et alcalino-terreux

Résumé On a étudié les possibilités de l'usage du photomètre de flamme pour la détermination quantitative de quelques éléments fréquents dans diverses alliages ferreuses. Parmi ces éléments on a étudié spécialment le cobalt, le nickel, le chrome et le manganèse. La sensibilité de ces éléments dans les méthodes de photométrie de flamme est petite et leur émissions sont affectées par la grande concentration du fer des échantillons, même dans les aciers avec des teneurs élevées de nickel et de chrome. On doit donc faire une séparation préalable du fer, que nous avons effectuée par extraction avec des solvants organiques, ayant étudié de même les récupérations quantitatives des autres métaux dans les solutions privées de fer. D'autre part on a étudié les interférences mutuelles de ces éléments pour arriver à des conclusions sur les erreurs que peuvent apparaître on cours des mesures. On discute aussi la séparation préalable du nickel et les modes opératoires. Quelques résultats sont donnés sur l'analyse de divers échantillons d'acier et de ferromanganèse. Les différences entre les valeurs photométriques et obtenues par voie chimique sont aussi indiquées.

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Summary A study has been made of the use of the flame photometer for determining quantitatively some of the elements found in various ferrous alloys. Among these elements, special studies have been made of cobalt, nickel, chromium, manganese. The sensitivity by the high concentration of iron in the samples, even in steels containing much nickel and chromium. Consequently, the iron should be removed beforehand. The writers accomplished this by extraction with organic liquids, after they studied the quantitative recovery of other metals in solutions freed of iron. A study has also been made of the mutual interferences of these elements to arrive at conclusions regarding the errors which may appear during the course of the measurements. A discussion is given of the preliminary separation of nickel and the procedures. Analyses of different samples of steel and ferromanganese are reported. The differences between the photometric values and those obtained by chemical methods are also pointed out.

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Zusammenfassung Die Möglichkeit der Verwendung der Flammenphotometrie zur quantitativen Bestimmung einiger Elemente, die sich häufig in Eisenlegierungen finden, wurde untersucht. Besonders Kobalt, Nickel, Chrom und Mangan wurden hierbei in Betracht gezogen. Die Empfindlichkeit der Flammenphotometrie für diese Elemente ist gering. Deren Emission wird durch hohe Eisenkonzentrationen beeinträchtigt, auch wenn der Gehalt an Nickel und Chrom im Stahl beträchtlich ist. Daher muß das Eisen vorher abgetrennt werden. Dies wurde durch Extraktion mit organischen Lösungsmitteln durchgeführt, da festgestellt werden konnte, daß sich die übrigen Elemente in den von Eisen befreiten Lösungen quantitativ auffinden lassen. Weiters wurde die gegenseitige Störung dieser Elemente untersucht, um auf allenfalls dadurch bedingte Fehler aufmerksam zu werden. Die vorhergehende Abtrennung des Nickels und die dazu geeigneten Methoden werden erörtert. Einige Analysenergebnisse von verschiedenen Stählen und Mangan-Eisen-Legierungen werden angeführt. Die sich zwischen photometrischer und chemischer Analyse ergebenden Differenzen werden angegeben.