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  • Author or Editor: S. Pandey x
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Abstract  

The direct production of copper sulphate from copper ore is an important route to recover copper. The condition, however, is dependant on temperature and sulphatising environment. The oxidation of chalcopyrite in static air bed condition has been studied by TG/DTA and DSC techniques. The addition of catalysts, improved the sulphation by in-situ producing better condítions. The mutual effects of sulphides were further confirmed by studying the oxidation reaction on pure copper-iron sulphides and results so obtained were corroborated with X-ray diffractrograms. With only chalcopyrite a mass gain of 8% (TG) corresponding to copper sulphate formation was observed, in the temperature range 628–738 K. The TG plots showed respective mass gain of 14, 17 and 12% in presence of Fe2O3, Na2SO4 and FeSO4 with chalcopyrite in the wider temperature range 628–923 K. As such the cupric sulphide had a negligible tendency of sulphation, which increased with the addition of ferrous sulphide mixture under the temperature range studied. At higher temperature copper ferrite formation was found.

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Sixty durum wheat genotypes were analysed for protein (gliadin) polymorphism to find out the existing genetic diversity, and to assess its utility for improvement in grain yield along with quality traits. Six different Gli-B 1 alleles were found in land races, rust resistance sources and old released varieties, while two in recently released and advance lines. Most of the recently released varieties and advance lines showed γ-45/ Gli-1 alleles, which is the best type for pasta making quality, remaining showed γ-42/ Gli-1 allele, which are not good for pasta making. It is advisable to select for γ-45/ Gli-1 as a bio-chemical marker in the future breeding programmes. The rust resistance sources do not possess γ-45/ Gli-1 alleles, so these lines can be used as donors to introduce disease resistance in the good quality recently released varieties, which are containing γ-45/ Gli-1 alleles. From hierarchical analysis, it was found that landraces, released varieties and rust resistance sources are genetically distinct. The presence of new γ-gliadin patterns are interesting in rust resistance sources and need to be investigated for their role in pasta making as well as overall technological quality of durum wheat.

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Abstract  

A simple and rapid, laser fluorimetric method for the determination of uranium concentration in raffinate stream of Purex process during reprocessing of spent nuclear fuel has been developed. It works on the principle of detection of fluorescence of uranyl complex formed by using fluorescence enhancing reagent like sodium pyrophosphate. The uranium concentration was determined in the range of 0–40 ppb and detection limit of 0.2 ppb. The optimum time discrimination is obtained when the uranyl ion is complexed with sodium pyrophosphate. Need of preconcentration step or separation of uranium from interfering elements is not an essential step.

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The dithiocarbamato complexes of titanyl(IV), zirconyl(IV) and hafnyl(IV), abbreviated as MO(S2CNRR)2·nH2O(M=Ti, Zr or Hf,R=H,R′=C5H9;R=H,R′=C7H11,n=1 for Ti andn=2 for Zr and Hf), were prepared in aqueous medium and characterized by elemental analyses, magnetic susceptibility measurements and IR spectral studies. The thermal behaviour of these compounds under non-isothermal conditions was investigated by thermogravimetric, derivative thermogravimetric and differential scanning calorimctric techniques in nitrogen and oxygen atmospheres. The intermediates obtained at the end of various thermal decomposition steps were identified on the basis of analyses and IR spectral studies. Kinetic parameters, such as apparent activation energy and order of reaction, were determined by the graphical method of Coats and Redfern. The heats of reaction for the different decomposition steps were calculated from the DSC curves.

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Grain yield and quality under terminal heat stress (post anthesis) are the most complex traits that are influenced by environmental factors and are characterized by low heritability and large genotype × environment interactions. The present study was undertaken to determine effectiveness of selection for genotypes tolerant to heat stress using differences in 1000-grain weight (dTGW) under the optimum and late sown field condition. A Recombinant Inbred Line (RIL) mapping population derived from the heat sensitive genotype Raj 4014 and heat tolerant genotype WH730 was evaluated for the heat stress over 2 years in a replicated trial under optimum and late sown field conditions. The parental lines were screened with approximately 300 SSR (μsatellite) markers out of which about 20% showed polymorphism. These polymorphic markers were utilized for genotyping a subset that had clear contrasting variation for dTGW. The difference in TGW between the timely and late sown conditions was used as a phenotypic trait for association with markers. Analysis of the two years data under timely and late sown condition revealed parents and their RILs clearly showing variation with respect to the dTGW. Regression analysis revealed significant association of dTGW of RILs with two markers viz., Xpsp3094, and Xgwm282 with coefficients of determination (R2) values of 0.14 and 0.11, respectively.

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Abstract  

Personnel from the Pennsylvania State University's Breazeale Nuclear Reactor assisted NRC (Nuclear Research Corporation) personnel in calibrating a new MSL/16N Nitrogen-16 Monitor. This paper describes the neutron flux calibration procedures utilized and the results obtained for the production of a nitrogen-16 source of known activity for a BGO detector calibration.

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Abstract  

A simple analytical procedure for the sequential determination of uranium (IV), free acidity and hydrazine in presence of hydrolysable ions is developed and described. In this method, first, uranium (IV) is determined using fiber optic aided spectrophotometry then same solution is used for determination of free acidity and hydrazine. Free acid is titrated with standard sodium carbonate solution after uranium (IV) is masked with EDTA. Once the end point for the free acid is determined at pH 3.0, an aliquot of formaldehyde is added to liberate the acid equivalent to hydrazine which is then titrated with the same standard sodium carbonate solution using an automatic titration system. The described method is simple, accurate and reproducible. The overall recovery of uranium (IV), nitric acid and hydrazine is 98% with 3% relative standard deviation respectively. The major advantage of the method is that it uses sodium carbonate a primary standard as titrant and generation of corrosive analytical wastes containing oxalate or sulphate is avoided. Valuable metals like uranium and plutonium can easily be recovered from analytical waste before final disposal.

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Abstract  

Several human tumors such as neuroendocrine tumors, medullary thyroid carcinoma, etc., express somatostatin receptors which specifically bind somatostatin and its analogues such as lanreotide, octreotide, etc. In order to prepare a therapeutic agent for targeting such tumors, attempts were made to prepare 90Y-DOTA-Lanreotide. Lanreotide could be successfully conjugated with the macrocyclic chelating agent DOTA (1,4,7,10-tetraaza cyclododecane tetracetic acid) which forms stable complexes with 90Y. 90Y-DOTA-Lanreotide could be prepared in >98% radiochemical purity and remained stable for 72 hours at room temperature. The tracer showed specific binding to A431 cells. Biodistribution studies in C57BL6 mice bearing melanoma showed ∼1.3% uptake pergram of tumor at 24-hour p.i.

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Zinc is essentially required for crop growth and its insufficient supply to the plants may severely limit the yield traits of a crop. A field experiment was performed during rabi season of 2009–10 and 2010–11 to evaluate the performance of different wheat genotypes under different levels of zinc namely 0 kg ZnSO4 ha−1, 20 kg ZnSO4 ha−1 and 20 kg ZnSO4 ha−1 along with foliar spray of 0.5% solution of ZnSO4. Genotypes responded positively in terms of tiller number, grain and biological yield, spikelet length, spikelet number, grain number and thousandgrain weight. The best response was observed with the application of 20 kg ZnSO4 ha−1 along with foliar spray of 0.5% solution of ZnSO4. Zinc application brought about a maximum increase of 58.6% in tiller number, 63.7% in thousand-grain weight, 40.5% in biological yield, 66.1% in grain yield irrespective of genotypes and the year of study. Wheat genotypes exhibited a variation in their performance which has been exploited in this study. Genotypes UP-262, PBW-175, PBW-343 were found to be superior for one or the other yield contributing factors.

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Genetic relationships among 24 genotypes of Hyophila involuta collected from five different natural populations of Mount Abu (Rajasthan) is analysed using RAPD and SSR markers. Based on efficiency parameters calculated for each marker system such as polymorphic information content (RAPD = 0.34; SSR = 0.66), marker index (RAPD = 2.78; SSR = 2.62) and resolving power (RAPD = 8.13; SSR = 2.23), the RAPD marker system shows higher values for some indices but microsatellites are more accurately reproducible than RAPD. Moreover, in case of the SSR, the average number of alleles was almost twice compared to RAPD. Mean coefficient of genetic differentiation between populations with RAPD was Gst = 0.269, while with SSR marker was Fst = 0.224. The UPGMA cluster analysis assembled genotypes into two main clusters with diverse levels of sub-clustering within the clusters. Also, the Mantel test showed no significant correlation between geographical and genetic distances. The observed moderately high genetic variability can be explained by efficient spore dispersal. Other factors such as reproductive mode, somatic mutation, continuous propagule recruitment and high degree of intermingling have great impact on the level of genetic variability in moss populations.

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