[en] Biogas, the end product of anaerobic digestion of cattle dung, can successfully supplement the cooking fuels in the countryside areas of India, where the raw material needed for its production is plentifully available. Because of the lack of awareness regarding selection of a suitable model and size of biogas plant, the full potential of the biogas producing material is not harnessed, and the economic viability of biogas technology is rendered doubtful. To facilitate this decision making, the economics of family size biogas plants, i.e. with capacity from 1 to 6 m³, was studied, and three prevalent models, viz. KVIC, Janta and Deenbandu, were compared. Calculations for installation cost and annual operational cost were made for the state of Punjab, India, where the hydraulic retention time is 40 days, and current market prices were taken into account. Comparison of the economics revealed that the cost of installation and annual operational cost of each capacity were higher for the KVIC model, followed by the Janta and then the Deenbandhu model. Irrespective of the model, as the capacity of the biogas plant increases, the installation, as well as the annual operational cost increase proportionately. With increase in capacity, the payback period decreased exponentially with the exponential character being highest for the KVIC model, followed by the Janta and then the Deenbandhu model. However, on the basis of comparative economics, the Deenbandhu model was found to be the cheapest and most viable model of biogas plant

[en] Fission product yield studies in the reaction of 99.2 MeV ¹⁹F with ²⁰⁹Bi have been carried out for the first time using gamma-ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products was found to be symmetric and broad with FWHM around 22 mass units and peak near mass 111. The average number of neutrons emitted per fission has been found to be around 6.7. The comparison of the fission products yield distribution of ²⁰⁹Bi using projectiles like ⁴He, ¹²C, ¹⁶O, and ¹⁹F have shown that the mass of symmetric peak increases as the mass of the compound nucleus increases. The high fission yield around mass 112 has been attributed to the presence of deformed neutron shells. The total fission cross section and width of the mass distribution have been found to be low in case of ¹⁶O induced fission as compared to the ⁴He, ¹²C, and ¹⁹F induced fission of ²⁰⁹Bi. (author)

[en] The segmented gamma ray scanning system developed for the assay of plutonium present in 200 L waste drums was modified for the estimation of gram amounts of plutonium in the presence of high beta gamma activity. A multi gamma ray source of ¹⁵²Eu having ∼1 mCi activity was used for the determination of attenuation correction factors for high count rate drums. Dead time corrections were applied to arrive at the corrected count rates for all the gamma rays. Present study has shown that the estimation of ∼1 g of ²³⁹Pu in a waste drum can be carried out in the presence of ¹³⁷Cs up to an activity level of 20 mCi. (author)

[en] The waste drum monitoring system based on HPGe detector was used to study its performance for the estimation of low amounts of plutonium in presence of high activity of ¹³⁷Cs and ⁶⁰Co. The counting was carried out by keeping amount of plutonium constant at 100 mg level and varying the count rate for the γ rays of ¹³⁷Cs and ⁶⁰Co. Present study has shown that the estimation of low amount of ²³⁹Pu in a waste drum can be carried out using 129 keV γ ray in the presence of ¹³⁷Cs up to an activity level of 16 mCi and in the presence of ⁶⁰Co up to an activity level of 8 mCi. (author)

[en] Superparamagnetic and biocompatible β-NaFeO₂ nanoparticles have been examined for treatment of cancer by nanohyperthermia. The synthesized nanoparticles and their nanofluid have been characterized by various techniques such as dynamic light scattering (DLS), Zeta potential, nanohyperthermia and in vitro cytotoxicity. DLS study has been conducted to find hydrodynamic radius of the nanoparticles and it revealed that for 10 day of ageing hydrodynamic radius for synthesized nanoparticles is 64 nm. Zeta potential study has been carried out to understand electro-kinetic parameters of nanofluid. The synthesized nanoparticles possess Zeta potential +37.48 mV to −43.51 mV for varying pH from 1 to 12. The isoelectric point has been observed at pH 3.43. The nanohyperthermia study has been done by measuring induction heating characteristics of nanofluid. The field 251.4 Oe has been found to be the best suitable field for the treatment of cancer by hyperthermia. The in vitro cytotoxicity of synthesized β-NaFeO₂ nanoparticles has been carried on HeLa cancer cell line. The mechanisms responsible for induction heating, electro-kinetic properties and hydrodynamic radius changes have been discussed. (paper)

[en] The mass-yield distributions of various fission products have been determined in the 50-, 60- and 70-MeV end point bremsstrahlung induced fission of ^natPb using off-line γ-ray spectrometric technique in the electron linac at Pohang Accelerator Laboratory, Korea. The mass-yield distributions are symmetric with average mass of 102.34, 102.25 and 102.03 and FWHM of 21, 22 and 23 mass unit, respectively. From the present data and literature data in the 50-85 MeV bremsstrahlung induced fission of ²⁰⁹Bi the following observations were obtained: (i) The average masses of the yield distributions in the 50-85 MeV bremsstrahlung induced fission of ^natPb and ²⁰⁹Bi are around 102.25 ± 0.25 and 103 ± 0.5, respectively. (ii) The FWHM of the mass-yield distributions increases from about 21 mass units at 50 MeV to 23 mass units at 70-85 MeV, which is explained from the point of increase in multi-chance fission probability with increasing excitation energy. (iii) Within the bremsstrahlung energy range of 50-85 MeV, the role of nuclear structure effect in the mass-yield distribution was observed in the photo-fission of ²⁰⁹Bi, whereas it was not seen in case of ^natPb. This may be due to the presence of so many isotopes in ^natPb unlike mono-isotopic ²⁰⁹Bi. (author)