Proceedings of the Indian Academy of Sciences - Section A

Raman, C.

doi: 10.1007/BF03046295pmid: N/A

Twelve spectrophotometer records of the absorption by NaF plates are reproduced covering the wavelength range between 7µ and 23µ for absorption paths ranging from 21 mm. down to 0·18 mm. The octave of the fundamental mode of highest frequency records itself as a sharply-defined absorption at 18·2µ. This gives 275 cm.−1 as the fundamental frequency, in fair agreement with the theoretically computed value of 281 cm.−1 It also fits in with the observed infra-red reflexion maximum at 36µ.

Puranik, P.; Rao, E.

doi: 10.1007/BF03046296pmid: N/A

Diphenyl methane has been subjected to normal co-ordinate treatment assuming the phenyl groups to be point masses. The Wilson F-G matrix method has been employed to obtain the secular equation in order to calculate the fundamental frequencies. In calculating the thermodynamic properties, contributions from the ring frequencies are also included.

Rangaswami, S.; Sambamurthy, K.; Sastry, K.

doi: 10.1007/BF03046297pmid: N/A

The leaves ofRhododendron cinnabarinum Hook. have been examined for their chemical constituents. Ursolic acid and quercetin were isolated and characterized. In addition two minor components, which could not be identified or characterized, have also been obtained.

Devanathan, T.

doi: 10.1007/BF03046298pmid: N/A

Venkateswarlu, K.; Thanalakshmi, R.

doi: 10.1007/BF03046299pmid: N/A

A normal co-ordinate treatment has been carried out to calculate the force constants of BH3CO and BD3CO molecules, on the basis of a Urey-Bradley potential force field.

Anantakrishnan, S.; Radhakrishnamurti, P.

doi: 10.1007/BF03046300pmid: N/A

The study of hydrolyses of the diesters of benzene dicarboxylic acids as a consecutive reaction and of the sodium salt of the half ester in mixed solvents clearly indicates that both in the first and in the second stage the reaction is only of the ion-dipole type. Calculations of the dimensions of the reactant species show that the most reasonable values are given by the Laidler approach while the Ingold calculations probably give the dimensions of the solvated transition state.

Venkateswarlu, K.; Rajalakshmi, K.

doi: 10.1007/BF03046301pmid: N/A

Urey-Bradley force constants of ketene and deuteroketene have been evaluated by the normal co-ordinate treatment. Using these force constants, the fundamental vibrational wave-numbers for ketene and its deuterium analogue have been calculated and compared with the observed bands.

Gopinathan, K.

doi: 10.1007/BF03046302pmid: N/A

The extraction of niobium by di-isobutyl ketone from hydrochloric acid solutions is investigated. This method is made use of in the preparation of the neutron-deficient Nb92 in high specific activity. Nb92 is produced by (n, p) reaction in Mo92 using natural molybdenum irradiated in the reactor. The effect of (n, p) reactions in other naturally present isotopes of molybdenum, on the radiochemical purity of the sample, is discussed.

Jain, B.; Singh, J.

doi: 10.1007/BF03046303pmid: N/A

Lanthanum, gadolinium and yttrium are quantitatively precipitated by diammonium-5, 5′-indigo disulphonate between pH 3·0 and 7·5 and the resulting complexes on ignition give the corresponding oxide which can be weighed. Quantities as little as 4·75 mg. of La2O3, 3·3 mg. of Gd2O3 and 4·2 mg. of Yt2O3 can be thus determined.

Rao, M.

doi: 10.1007/BF03046304pmid: N/A

The distributional pattern of manganese in the shelf sediments off east coast of India has been determined. It is found that sediments from the immediate vicinity of river confluences, those of finer texture, and also those that are brownish in colour are generally more enriched in manganese. Manganese content decreases in a direction that is seaward from the coast and away from river confluences. An inverse relationship between the manganese content and the carbonate content of these sediments has been established, the richer the sediment in carbonate content the less the manganese concentration.