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  • Author or Editor: R. Mishra x
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A field experiment on a greengram-wheat cropping sequence was carried out under limited water supply conditions in 1997-98 and 1998-99 at the farm of the Indian Agricultural Research Institute, New Delhi. The greengram was sown either on flat beds or on broad beds 2 m in width, divided by furrows, with 0, 30 and 60 kg P2O5/ha. After the harvest of greengram pods, wheat was grown in the same plots, either with the greengram stover removed or with the stover incorporated along with 0, 40, 80 and 120 kg N/ha applied to wheat. The grain yield of greengram was higher when sown on broad beds with furrows compared to flat bed sowing, and the application of 30 or 60 kg P2O5/ha resulted in significantly higher grain yields compared to no phosphorus application. The combination of broad bed and furrows with phosphorus fertilization was found to be ideal for achieving higher productivity in greengram. The land configuration treatments had no impact on the productivity of wheat. The application of phosphorus to the preceding crop had a significant residual effect on the grain yield of wheat. The incorporation of greengram stover also significantly increased the grain yield of wheat. The increasing levels of N increased the grain yield of wheat significantly up to 80 kg/ha. The combination of greengram stover incorporation and 80 kg N/ha applied to wheat significantly increased the grain yield. Further, there was a significant interaction effect between the phosphorus applied to the preceding crop and N levels given to wheat on the grain yield of wheat.

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Toxic trace metals like mercury, arsenic and cadmium have been determined in widely used Indian chewing tobacco and cigarette tobacco by neutron activation followed by sequential radiochemical separation (RNAA). Differential Pulse Anodic Stripping Voltammetry (DPASV) has been used for the estimation of lead, cadmium and copper in cigarette tobacco and its smoke aerosols. The reliability of the data has been assured by analyzing standard reference materials, bovine liver (NBS-1577) and orchard leaves (NBS-1571), and intercomparison of the Pb, Cd and Cu values by three techniques, namely, RNAA, DPASV and Energy Dispersive X-ray Flourescence technique (EDXRF). The levels of Hg, Cd, As, Pb and Cu in cigarette and chewing tobacco and the estimated intake of Cd, Cu and Pb to the smoker are presented and discussed.

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Optimum temperature and pH for the isolation of soy protein isolate (SPI) from soy protein concentrate (SPC) were established. Enzymatic hydrolysis of SPI with enzymes of different specificities such as trypsin, chymotrypsin, papain and urease was carried out and the products of hydrolysis were characterized by molecular mass determination [sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)] and thermal techniques [differential scanning calorimetry (DSC) and thermogravimetric analysis (TG)]. Enzymatic hydrolysis resulted in a significant reduction in molecular masses. However the thermal stability of hydrolysed SPI was similar to native SPI indicating that it is independent of molecular mass. DSC studies indicated an increase in temperatures of endothermic transition associated with SPI denaturation and loss of absorbed moisture in samples of lower molecular masses.

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A microwave-assisted ultraviolet sterilization system was developed to study the synergistic effect in the sterilization of milk. Electrodeless lamps emitting ultraviolet radiation inside the microwave chamber gave a synergistic effect without challenging food safety standards. This study compared the results of both microwave and microwave assisted ultraviolet sterilizations of milk in terms of various microbial tests and physicochemical properties. The microwave-assisted ultraviolet system was found to be more effective compared to microwave alone. A significant difference (P<0.05) was observed for total plate count and methylene blue reduction test between microwave and microwave assisted ultraviolet treatment from 5 to 15 secs. Microwave-assisted ultraviolet treatment decreased the microbial count exponentially and showed <1 log (CFU ml–1) after ten seconds of treatment. During the treatment period, no significant difference was observed in the physicochemical properties of milk.

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Sixty-seven cultivars and advanced breeding lines from three major Indian wheat-producing zones were used to investigate the presence of 1RS.1BL translocation and high molecular weight glutenin subunits (HMW-GS), and to determine their effect on bread loaf volume and yield. The frequency of 1RS.1BL translocation was detected in 50.7% of the genotypes. Three, five and two allelic variations were observed at Glu-A1, Glu-B1, Glu-D1 , respectively. The genotypes with 1RS.1BL translocation were significantly high in grain yield and bread loaf volume than genotypes without 1RS.1BL translocation. The majority of genotypes (76.4%) possessing 1RS.1BL translocation had HMW-GS 5+10. It was concluded that the deleterious effect of rye translocation can be compensated by desirable HMW-GS at Glu-D1 locus.

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The burning rate of AN–HTPB-based propellant catalysed with chromium salt has been studied using conventional strand burner under the various pressure range, i.e. from atmospheric pressure to 6.897 MPa and verified with Piobert law, i.e. r = aP n. At atmospheric pressure, the burning rate AN–HTPB propellant was being accelerated with the chromium-based catalysts used. In case of lead chromate-catalysed system, burning rate was observed 2.655 times higher than burning rate (r = 0.200 mm s−1) of virgin AN–HTPB propellant sample. However, the Copper chromate-catalysed propellant burned with slower rate (r = 0.160 mm s−1) than the virgin AN–HTPB propellant sample. The burning rate of all catalysed propellant samples are found to be the pressure sensitive and accelerated higher with rise of pressure. The highest burning rate (r = 2.422 mm s−1) was recorded with ammonium dichromate and lowest (r = 1.40 mm s−1) with lead chromate-catalysed propellant sample with the rise of pressure up to 6.897 MPa at different pressures. A linear relationship was observed between the burning rate and pressure rise which followed the Piobert law, i.e. r = aP n. The pressure index (n) values of AN–HTPB-based samples were calculated higher when catalysed with ammonium dichromate, Copper Chromate, Cr2O3, Potassium dichromate (n = 0.525, 0.555, 0.429, and 0.408 respectively) and lower (n = 0.226) with lead chromate compared to virgin sample (n = 0.405). Higher value indicates the positive effect on accelerating the burning rate with catalyst at higher pressure ranges.

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Thorium along with its daughter products present in the soil is one of the major contributors to the external gamma dose in the environment. To establish the dose levels, quantification of thorium contents in soil samples is very important. As a part of pre-operational environmental radiological surveillance, a total of 23 soil and six sand samples were collected from different locations around the proposed nuclear power plant site of Jaitapur, Maharashtra. Thorium concentrations in these samples were determined by instrumental neutron activation analysis (INAA). Samples were irradiated with neutrons in Apsara reactor at a neutron flux of ~5 × 1011 cm−2 s−1 and radioactive assay was carried out using high resolution gamma ray spectrometry. Relative method of INAA was used for quantification of thorium utilizing 311.9 keV gamma ray of 233Pa, the daughter product of 233Th. The concentrations of thorium in the soil and sand samples were in the ranges of 4.0–18.8 and 1.2–6.2 mg kg−1 respectively.

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Barium borosilicate glass (BaBSG) is proposed as a potential candidate for vitrification of nuclear waste generated from thoria based nuclear reactors. Along with fission products, activation products and many inactive chemicals, like fluorine in the form of HF are expected to be present in the dissolver solution with nuclear waste. As vitrification occurs at high temperature, it is important to quantify fluorine in BaBSG. Due to its complex matrix, most of the wet chemical and nuclear analytical methods encounter problems in the estimation of fluorine. Particle induced γ-ray emission (PIGE) method has been standardized for non-destructive determination of fluorine contents in BaBSG samples utilizing measurement of prompt gamma-rays from 19F (p, p’γ) 19F reaction. Experiments have been carried out with thick pellet targets prepared in cellulose matrix using 4 MeV proton beam from the folded tandem ion accelerator at BARC, Mumbai. For obtaining current normalized count rate of interest, beam current variation was monitored by the Rutherford backscattering spectrometry (RBS) method as well as by the in situ approach using an externally added element sensitive to PIGE. In this paper standardization of PIGE methods for F determination, validation of methods using synthetic samples, and application to BaBSG samples are reported.

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