Browsing by Author "B.M. Shukla"

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Adsorption of phosphate ions on antimony tetroxide by radioactive tracer technique
(1973) I.S. Singh; V.N. Singh; R. Tripathi; B.M. Shukla
[No abstract available]
Dissolution effect on the retention of 128l in solid kio3
(1982) R.K. Bera; B.M. Shukla
Dissolution effect on the 128I retention in solid KIO3 has been studied. The neutron irradiated and annealed solids, when dissolved in dilute nitric acid solution, produced retention higher than when dissolved in neutral aqueous and in basic solutions. Also, remarkable variation in retention is found with the variation of pH of dissolution. Metastable radiohypoiodite and radio-iodite species have been assumed to be formed in irradiated and annealed solids and to be responsible for the observed variation of retention with the dissolution condition. Contribution of the hot zone model for the formation of metastable species has been discussed. © 1982, Walter de Gruyter. All rights reserved.
Electromigration studies of bivalent ions by radio-tracer technique
(1973) R.P. Gupta; B.M. Shukla
[No abstract available]
Influence of benzene moderator on the recoil collection of128I charged species during an (n, γ) process
(Kluwer Academic Publishers, 1988) C. Pandey; B.M. Shukla
Recoil reactions of128I in liquid methyl iodide, ethyl iodide and n-butyl iodide target systems in the presence of benzene diluent have been studied by the charged plate technique. The investigations have been carried out over a wide range of diluent concentration. It has been observed that there are more collected recoil charged128I species on the anode than on the cathode. The presence of benzene diluent in the target systems prior to neutron irradiation reduces the recoil collection on both electrodes. © 1988 Akadémiai Kiadó.
Initial retention in lodates and periodates after (n, γ) reaction
(1980) R.N. Singh; B.M. Shukla
Low temperature investigations of the Szilard-Chalmers reaction in HIO3, KH(IO3)2;NaIO4 and Na3H2IO6 have been carried out. The influence of the capture γ-ray of 12-I has been considered for explaining the initial retention. © 1980, Akademische Verlagsgesellschaft, Wiesbaden
(n, γ) Reaction in H5I06
(1981) B.M. Shukla; R.K. Bera
(n, y) reactions have been studied with H, 10 6 in both solid and alkaline aqueous phases. Isochronal thermal annealing of the neutron irradiated solid showed a rapid conversion of radioiodate to radioperiodate within a small range of temperature rise. Beyond 90 °C, a reverse effect is observed. Radio lytic oxygen and hydro xyl radicals from associated water molecules have been considered responsible for the observed variation. In alkaline aqueous phase irradiation with the increase of C2 H5 OH as additive, mainly the radioiodide fraction is found to increase at the cost of radioiodate. There is a small but significant increase in retention. The possible role of additives has been described. © 1981, Akademische Verlagsgesellschaft, Wiesbaden
Some studies on (n, γ) recoil of lodine-128 in alkaline aqueous lodate and periodate
(1978) R.K. Bera; B.M. Shukla
(N, γ) reactions in alkaline aqueous solutions of KIO, and KI04 have been studied in presence of chloride and acetate additives. It has been found that the retentions and yields are remarkably influenced by additives. The radioiodate, -iodide and -periodate fractions observed from neutron irradiation of alkaline aqueous KIO3 are about 20%, 75% and 5%, respectively, while those observed from alkaline aqueous KI04 are about 80%, 10% and 10%, respectively. With the increase of concentrations of the additives, the radioiodate, -iodide and -periodate yields reach the limiting values of about 28%, 54% and 18%, respectively, from both KIO3 and KI04. The irradiation in frozen alkaline aqueous phase leads to retentions and yields remarkably different from those observed in the aqueous phase. The role of water molecules and additives, post recoil effect and chemical effects associated with local radiolysis and internal conversion are discussed to explain the observed results. © 1978, Walter de Gruyter. All rights reserved.
Structural characterization of anthracene‐picric acid eutectic system
(1985) N.P. Singh; B.M. Shukla
The eutectic composition has been derived from phasediagram studies and the nature of eutectics has been established by thermal and spectral studies. Diffraction studies reveal the establishment of preferential ordering and the crystalline character of eutectics. Copyright © 1985 WILEY‐VCH Verlag GmbH & Co. KGaA
Structure of Melts in Binary Organic Eutectics and Molecular Complexes. Phenanthrene-Picric Acid and Anthracene-Picric Acid Systems
(1985) N.P. Singh; B.M. Shukla; Narsingh Bahadur Singh
Phenanthrene-picric acid and anthracene-picric acid systems were chosen for detailed thermochemical measurements. Phase-diagram studies confirmed that a maximum Is surrounded by two eutectics, and a molecular complex of 1:1 stolchiometry with congruent melting is formed in both systems. Enthalpy of fusion values do not obey the mixture law. The exothermic mixing confirms the compound formation in both systems. The values of enthalpy of mixing for the eutectics show the tendency of ordering in the melts. © 1985, American Chemical Society. All rights reserved.
Studies on parameters controlling the degree of undercooling, naphthalene-picric acid and anthracene-picric acid systems
(1985) N.P. Singh; B.M. Shukla; Narsingh Bahadur Singh
The effects of cooling cycle number, cooling rate, quantity of melt and alloy composition on degree of undercooling were determined experimentally. Naphthalene-picric acid and anthracene-picric acid were chosen for the detailed studies. The intensity of the effect on the two systems was different but the trend was the same. The undercooling, instead of being a definite value, was found to be a function of cooling rate, melt quantity, alloy composition and the freezing cycle number. © 1985.
Thermal, mechanical and spectral studies of some organic charge-transfer complexes
(1985) B.M. Shukla; N.P. Singh
The thermal, mechanical and spectral properties of complex formed by picric acid with naphthalene and anthracene respectively have been studied using phase-diagram, linear velocity of solidification, degree of undercooling, fracture value, modulii of elasticity and IR, UV-visible spectral measurements. The phase-diagrams show that the 1:1 molecular complexes which are formed in these systems are stable in the solid state and remain intact in the molten state. The kinetics of solidification in both follows the Hilling and Turnbull equation and the observed kinetic data suggest the Winegard et al, mechanism for the solidification phenomena in the two complexes. The experimental and the theoretically calculated values of heats of fusion were compared. These properties of the pure components and the complexes were studied in the light of molecular interactions which play an important role in deciding the crystal structure of binary organic systems with the formation of congruent melting compounds having structures consisting of infinite stacks of alternate donor and acceptor molecules. © 1985.
Tracer diffusion of131I- ions in a few 1-2 electrolytes in agar gel
(Kluwer Academic Publishers, 1985) Miss; S. Baluja; R.N. Singh; R. Tripathi; B.M. Shukla
Tracer diffusion of131I- ions is studied at different temperatures /20°C-50°C/ in 2.5% agar gel containing sodium and potassium sulphate solutions over a wide range of concentrations. The results are in qualitative agreement with the theoretical values in the concentration range 10-6-10-1M. Agar gel shows an obstruction effect to diffusional flow. The activation energy for tracer diffusion was found to be of the order of 16.3 kJ mol-1. © 1985 Akadémiai Kiadó.
Tracer-diffusion of H2 32P4− Ions in Electrolyte Solutions in Agar Gel Medium
(1984) S. Baluja; B.M. Shukla
The tracer-diffusion coefficients of H235PO ions have been determined in sodium and potassium nitrate solutions immobilized in 2.5 % agar gel over the concentration range 10-6-1.0 M at 298 K. Comparison of the experimental and theoretical values indicates failure of the Onsager-Fuoss theory at higher concentrations of electrolyte solutions. The observed results are explained on the basis of water-gel, ion-water and ion-ion interactions. Diffusion rates are also determined at various gel concentrations at different temperatures (298-323 K), keeping the electrolyte (KNO3) concentration constant at 10-2 M. The obstruction effect of gel calculated in terms of formation factor F is observed to increase with increasing gel concentration. The results are explained on the basis of EYRING's theory of diffusion. © 1984, Walter de Gruyter. All rights reserved.
Wall influence in the production of the joshi effect in chlorine under silent electric discharge
(1949) B.M. Shukla
The Joshi effect (∓Δi) in 170 mm. chlorine has been studied in a modified Siemens tube in which the ionization space could be filled with and emptied of powdered glass, the discharge being "wall influenced" and "normal," respectively. With both of these, due to 8-14 kv. of 50 cycles frequency, in the dark and in light, current i was observed in the aerial and the low-tension lines. A vacuum junction, a diode, and a triode were used as current indicators. In "normal" discharge ohmic resistance R reduces -per cent Δi = 100Δi/iD, owing to suppression of high frequencies, in which -Δi predominates, -per cent Δi in iaerial > in iL.T.. Under "wall" discharge an inversion -Δi ⇌ + Δi occurs at 9.2 kv. and 11 kv. in iL.T., and only at 9.2 kv. in iaerial. The inversion is entirely potential-reversible. Serial R and by-pass capacity C reduce (numerically) -per cent Δi at low potential. At large potential, where +Δi occurs, both these parameters produce a marked -per cent Δi. It is suggested that the positive effect occurs in super high frequencies, simultaneously with negative effect (the latter being associated with moderate high frequencies). With -per cent Δi produced at large potential with a serial R, a capacity parallel to R, providing an alternative path to the super high frequencies suppressed by R, should restore the positive effect. This has been observed. The generality of these results is in accord with Joshi's theory of the surface origin of this phenomenon.