[en] Indoor radon/thoron have been recognised as one of the health hazards for mankind. Common building materials used for construction of houses, which are considered as major sources of these gases in indoor environment, have been studied for exhalation rate of radon/thoron. 'Can' technique using plastic track detector LR-115 type-II has been used for measurement. Exhalation rates for radon and thoron have been found to be varying from a minimum value of 0.024 and 29.4 Bq m^-2 h^-1 for cement plastered brick to a maximum value of 0.16 and 692.2 Bq m^-2 h^-1 for unfired brick, respectively. Exhalation rate for thoron has been found to be several times higher than that for radon. Measured exhalation rates for thoron indicate significant presence of thoron in indoor environment which is also supported by indoor measurements of thoron and its progeny

[en] The electrochemical performance of mixed oxides, Ca₂Fe₂O₅ and Ca₂Co₂O₅ for use in Li-ion batteries was studied with Li as the counter electrode. The compounds were prepared and characterized by X-ray diffraction and SEM. Ca₂Fe₂O₅ showed a reversible capacity of 226 mAh/g at the 14th cycle and retained 183 mAh/g at the end of 50 cycles at 60 mA/g in the voltage window 0.005-2.5 V. A reversible capacity in the range, 365-380 mAh/g, which is stable up to 50 charge-discharge cycles is exhibited by Ca₂Co₂O₅ in the voltage window, 0.005-3.0 V and at 60 mA/g. This corresponds to recycleable moles of Li of 3.9±0.1 (theoretical: 4.0). Significant improvement in the cycling performance and attainable reversible capacity were noted for Ca₂Co₂O₅ on cycling to an upper cut-off voltage of 3.0 V as compared to 2.5 V. Coulombic efficiency for both compounds is >98%. Electrochemical impedance spectroscopy (EIS) data clearly indicate the reversible formation/decomposition of polymeric surface film on the electrode surface of Ca₂Co₂O₅ in the voltage window, 0.005-3.0 V. Cyclic voltammetry results compliment the galvanostatic cycling data

[en] The ability of the extreme halophile Halobacterium cutirubrum to recover from the effects of ultraviolet radiation during liquid holding in the dark in non-nutrient medium has been compared with that of (i) a moderately halophilic bacterium (NRC 41227) and (ii) Escherichia coli B. The photoreactivabilities of all three bacteria have also been studied. The extreme halophile was incapable of liquid-holding recovery in these conditions, in marked contrast to both E. coli B and the moderate halophile, and also failed to recover when held in nutrient medium in the dark. These results strongly support the hypothesis that H. cutirubrum lacks DNA excision repair. It was also found that ultraviolet-irradiated H. cutirubrum could be almost completely photoreactivated from any level of survival in the range 10^-₄-80%, provided exposure to visible light was not delayed, whereas the moderate halophile resembled E. coli B and had a comparatively limited capacity for photoreactivation. (Auth.)

[en] The present work deals with evaluation of the adaptation and biomass production of various switchgrass cultivars (upland and lowland type) in Southern Italy. A field trial was established in 1998 with 15 switchgrass varieties in ENEA Trisaia (Matera). The experiment was conducted for four years (1998-2001). During each growing period, a series of measurements were taken. At the end of each growing season, a final harvest was made in order to estimate the fresh and dry matter yields of the different varieties. The mean dry matter yield was recorded at a maximum (12.36 t/ha) in the third year, and it fluctuated from 5.63 (9005439) to 26.08 (SL 93-3) t/ha. The crop yields tend to stabilize from the fourth year of its cultivation. In fact, the yield recorded for this year was reduced to 10.27 t/ha, averaged over all the varieties

[en] Highlights: • Development of a helicon plasma system to carry out ion–ion plasma studies in electronegative gases such as Hydrogen, Oxygen and Chlorine. • Determination of initial parameters of helicon plasma source for ion–ion plasma by using dispersion relation of bounded helicon waves. • Design and development of solenoid with magnetic field strength production capability of ∼ 600 G along the axis of the chamber. • Optimization of the chamber parameters using Helic codes and estimation of optimum attainable density. • Estimation of RF power requirements for various gases. - Abstract: A helicon plasma system is being designed and developed at CPP-IPR. The design parameters of the system are deduced from the dispersion relation of bounded helicon waves and the required magnetic fields are simulated by using Poisson Superfish code. The Helic code is used to simulate the power deposition profile for various conditions and to investigate the optimum values of chamber parameters for effective coupling of radio frequency (RF) power to plasma. The helicon source system is aimed at carrying out ion–ion plasma studies in electronegative gases such as Hydrogen, Oxygen and Chlorine. The system mainly consists of a source chamber in which helicon plasma will be produced by injecting RF power at a frequency of 13.56 MHz through a right helical antenna in presence of a DC magnetic field followed by an expansion chamber in which it is expected to produce negative ions along with the positive ions. Installation of the various parts of the system is in progress. The details of the design and development of the system is presented in this article.

[en] Terbium sops (laureate, myristate and palmitate) were synthesized by direct metathesis of corresponding potassium soap with an aqueous solution of terbium nitrate. The physico-chemical characteristics of soaps in solid state were investigated by IR spectra, X-ray diffraction patterns and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding while the soaps possess partial ionic character. The X-ray analysis showed that the soaps have double layer structure with molecular axes slightly inclined to the basal plane. The thermal analysis suggested that the decomposition of soaps occur in two steps. The energy of activation, order of reaction and various kinetic parameters (i.e. frequency factor, entropy of activation and free energy) for the thermal decomposition of soaps were evaluated. (author). 26 refs, 4 figs, 4 tabs

[en] Tritiated water (HTO) injected intraperitoneally to Swiss albino mice at the rate of 370 kBq (10 μCi)/g body weight has been found to cause certain alterations in blood parameters 1, 5, 7 and 15 days post injectionem. Leukocyte count dropped significantly post treatment. Differential leukocyte counting showed lymphocytes to be most affected which were reduced by 38.29% on 5th day p.i. Erythrocyte count, haemoglobin and haematocrit values though showed no significant changes at early intervals, these values were significantly lower at later intervals than those of control. (author)

[en] An indoor radon/thoron survey has been carried out in selected villages in four districts of the state of Himachal Pradesh, India. This survey has been conducted using twin-chamber dosemeter cups designed by the Environmental Assessment Division (EAD) of the Department of Atomic Energy, of the Government of India. The track-etch technique was used for the calibration of an LR-115 type-II plastic detector employed in the recording of alpha tracks produced by radon and thoron and their daughter radionuclides. The indoor radon levels were found to range from a minimum value of 17.4 Bq/m³ to a maximum value of 140.3 Bq/m³, while indoor thoron levels ranged from a minimum value of 2.0 Bq/m³ to a maximum value of 92.2 Bq/m³. The annual average dose rate for the local population was calculated to range from 0.03 μSv/h to 0.83 μSv/h. The gamma dose rates in the dwellings were measured using an environmental radiation dosimeter (model ER 705). Gamma dose rates in the dwellings were found to range from a minimum value of 76.6 nGy/h to a maximum value of 330.6 nGy/h. (orig.)

No abstract available

[en] Radon is a radioactive inert gas, which is produced during the decay of radium, an element present in the naturally occurring uranium series. In the recent past, environmental scientists all over the world have been expressing great concern about the radiation hazard from radon and its short lived daughter products inside buildings. The radon concentration inside a building depends upon the radon exhalation from the building materials used for the construction and the soil underneath the building. In the present investigations, a comparative study for radon exhalation rate has been carried out in some Indian and Pakistani cements and other building materials being used locally such as sand, soil, bricks, marbles, CaCO₃, POPs by using Track Etch Technique. The Pakistani cement with the trade name 'Elephant' shows the minimum mass exhalation rate while the Indian 'Birla White' cement has shown the maximum. Among the other building materials studied, CaCO₃ has shown the minimum, while local soil the maximum mass exhalation rate. Out of the fired clay bricks, roof tiles, floor tiles and different marbles, floor tiles have the minimum areal exhalation rate while roof tiles the maximum. (author)