The nuclear magnetic resonance spectra of four spin systems

The ring proton resonance spectra ofα, β andγ picolines have been studied at 40 Mc./sec. The spectra which belong to the classes ABCX, ABXY and A₂X₂ respectively have been completely analyzed to determine all the involved parameters.     

Effect of longitudinal or inplane deformation and inertia on the large amplitude flexural vibrations of slender beams and thin plates

Large amplitude flexural vibrations of slender beams, and thin circular and rectangular plates have been studied when a compatible longitudinal or inplane mode is coupled with the fundamental flexural mode. It is shown that the effect of longitudinal or inplane deformation and inertia is to reduce the non-linearity in the flexural frequency-amplitude relationship. Further, for slender beams and thin plates, the effect of longitudinal or inplane inertia is negligible.     

A novel transformation of 2-dichloracetamido-1-methyl-5-nitroimidazole to 5-dichloroacetylimino-tetrahydroimidazo (4,5-c) pyrazoles.

2-Dichloracetamido-1-methyl-5-nitroimidazole undergoes novel cycloaddition with diazomethane to form 5-dichloracetylimino-tetrahydroimidazopyrazoles via 2-dichloracetylimino-1,3-dimethyl-5-nitroimidazoline.     

Secondary flow of a conducting fluid in a rotating straight annular pipe

A theoretical analysis is made of the flow of a conducting viscous and incompressible fluid through a straight annular pipe of circular cross-section flowing under a constant pressure gradient. The pipe is rotated about an axis perpendicular to it and also there is imposed a uniform magnetic field transverse to the motion. The secondary flow pattern has been studied in detail for small values of angular velocity and Hartman number.     

Polarography of divalent manganese in sodium formate solution

Summary A well defined wave for manganese in 1 M sodium formate solution is reported and its use for the determination of microquantities of the element is indicated. Several foreign ions studied do not cause any interferences.

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Zusammenfassung Die polarographische Bestimmung von Mikromengen Mangan kann mit gutem Erfolg in einer Grundlösung aus 1 m Natriumformiat durchgeführt werden. Eine Anzahl untersuchter Anionen verursacht keine Störungen.

     

Determination of lead by the precipitation of lead molybdate from a homogeneous solution by the diffusion method

A satisfactory quantitative method for the determination of lead as lead molybdate by precipitation from a homogeneous solution has been developed. The method employs the diffusion of ammonia into a solution containing lead and sodium molybdate in nitric acid medium. The precipitation of lead in the range of 28·0–280·0 mg is complete within 8–9 hours. Anions like sulphate, arsenate, phosphate, tungstate and chromate in moderate concentrations and cations such as Zn (II), Cu (II), Ni (II), Co (II), Mn (II), Cd (II), Hg (II), Ag (I), Ti (IV), As (V), Mg (II) and Al (III) do not contaminate the precipitate. The precipitate gets constant weight at 120°. This eliminated the ignition of the precipitate,i.e., the contamination of molybdic oxide by the precipitate was reduced.     

On slow motion of a sphere in a viscous liquid

Stokes’ and Seth’s solutions for the slow motion of a sphere in a viscous, incompressible liquid have been discussed from the viewpoint of the structure of the velocity field and its relation to the drag of the sphere. The problem is analysed from a different angle in this paper. It is believed that it throws more light on thephysics of the problem.