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  • Author or Editor: K. Singh x
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Abstract  

The sum peak intensity relative to its single peak was determined in various compounds of133Ba by the technique of gamma-ramma-ray sum peaks observed in a single HPGe detector. The change in intensity ratio was used to determine the time integral perturbed angular correlation coefficients for BaCl2, Ba(NO3)2, BaSO4, Ba-EDTA, Ba-MES and Ba-BSA compounds.

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Abstract  

The sum peak method based on the phenomenon of perturbed angular correlation has been applied to study the nuclear quadrupole interaction frequencies at133Cs which is followed by electron-capture decay of133Ba. These values are used to determine the z-component, which is the largest one of the electric field gradient. The electric field gradient /EFG/ is found to vary with different compounds of barium. The method is found to be useful in describing the chemical influences on the attenuation of angular correlations and hence in the study of EFG.

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Abstract  

The thermodynamic behaviour of bulk metallic glass (BMG) forming melts have been studied by analyzing the temperature dependence of the Gibbs free energy difference (∆G), entropy difference (∆S) and enthalpy difference (∆H)between the undercooled melt and the corresponding equilibrium solid phases. The study is made by calculating∆G, ∆S and ∆H in the entire temperature range T m (melting temperature) to T g (glass transition temperature) using the expressions obtained on the basis of Taylor’s series expansion. The entire analysis is made for La-based five samples of BMGs; La55Al25Ni20, La55Al25Ni15Cu5, La55Al25Ni10Cu10, La55Al25Ni5Cu15, and La55Al25Ni5Cu10Co5 and a comparative study is also performed between present results and results obtained in the framework of expressions proposed by earlier workers. An attempt has also been made to study the glass forming ability for BMGs.

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The CERES-rice model (version 4.0) was calibrated and validated using the data from a field experiment carried out during the rainy season of 2004 and 2005 at Shalimar, Srinagar (35° 5′ N latitude and 74° 89′ E longitude, 1587 m above the mean sea level, India. The experiment included six rice cultivars each transplanted on 25 May, 10 June and 25 June. Data of 25 May transplanting was used for model calibration and development of the genetic coefficients of the rice cultivars. The predicted and observed dates of phenological events were in close agreement with root mean square error (RMSE), mean absolute error (MAE) and D-index of 5.0 days, 4.3 days and 0.91, respectively, for anthesis and 3.7 days, 3.1 days and 0.91, respectively, for physiological maturity of the crop. The predicted and observed grain yields were also very close with a RMSE of 0.63 Mg ha −1 , MAE of 0.58 Mg ha −1 and D-index of 0.89, respectively. Corresponding values for above ground biomass was 1.17 Mg ha −1 , 1.01 Mg ha −1 and 0.82. Sensitivity test showed that simulated yield responded to temperature and atmospheric CO 2 concentration. Nitrogen 240 kg ha −1 at 25 May transplanting, recorded highest simulated grain yield (9.71 Mg ha −1 ). Further, 3 seedlings hill −1 produced highest simulated grain yield. The results suggest that the model can be applied in the temperate Kashmir to estimate crop productivity and optimize the management practices.

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Maize protein quality is deficit in essential amino acids, lysine and tryptophan. These constraints of o2 (opaque2) are corrected in genetically improved, hard endosperm QPM (Quality Protein Maize). An integrated strategy of phenotypic selection for endosperm modifiers and molecular marker-assisted foreground and background selection has been used in present study. The QPM donors were, CML 161, DMRQPM 58, CML 176 and CML 141 whereas, normal maize inbreds were CM 212, V338, V361, V336, V341, V351, CM 141 and V335. The inbreds were subjected to parental polymorphism survey between non-QPM and QPM using CIMMYT based three SSR markers, viz. phi057, umc1066 and phi112. Two markers, viz. phi057 and umc1066 exhibited co-dominant reactions, while phi112 was dominant in nature. Finally, two combinations V335 × CML 141 and V351 × CML 141 were considered for conversion program. Foreground selection was exercised using o2 specific marker umc1066 in BC1 and BC2 generations, while background as well as foreground selection was exercised in BC2F3 generation to recover the genome of recurrent parent up to extent of 80 to 100% with the help of SSR markers distributed across the whole maize genome. The tryptophan concentration in endosperm protein was significantly enhanced and the converted maize lines had almost twice the amount of lysine and tryptophan than normal maize inbreds.

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The present report is in continuation to our earlier reports on the identification and fine mapping of three aroma QTLs in basmati rice using a bi-parental mapping population derived from a cross between Pusa 1121, a basmati rice variety, and Pusa 1342, a non-aromatic rice variety. We used a combination of genetic mapping and transcriptome profiling to narrow down the number of differentially expressed genes in rice to identify potential candidate genes for rice grain aroma. Highly aromatic and non-aromatic recombinant inbred lines (RILs) were identified through sensory analysis of mature milled grains. RILs with similar phenotypes were bulked together using bulk segregant analysis approach which drastically reduced the number of differentially expressed genes from 4016 to 1344. The transcriptome profiles generated were analyzed through Affymetrix rice genome array containing probe sets designed from all the predicted rice gene sequences. Microarray-based transcriptome profiling revealed one down-regulated gene co-located in QTL region aro3.1 on chromosome 3, eight genes co-located in the aro4.1 region on chromosome 4 and the badh2 gene on chromosome 8 to be differentially expressed in the aromatic parent and aromatic bulk. These genes are the most suitable candidates for future validation and development of new molecular functional markers to facilitate marker assisted breeding.

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Summary  

Variants of δ-normality and δ-normal separation called weakly (functionally) δ-normal spaces are introduced and studied. This yields new factorizations of normality and δ-normality. A Urysohn type lemma and a Tietze type extension theorem for (weakly) functionally δ-normal spaces are obtained.

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Studies on energetic compounds

Part 40. Kinetics of thermal decomposition of some bis(propylenediamine)metal perchlorate complexes

Authors: G. Singh and D. K. Pandey

Bis(propylenediamine)metal perchlorate (BPMP) complexes like [M(pn)2](ClO4)2 (where M=Cr, Mn, Ni, Cu, Zn and pn=propylenediamine) have been prepared and characterized by gravimetric methods, infrared and elemental analysis. Thermal properties have been studied using simultaneous thermogravimetry-differential thermal analysis in atmospheres of nitrogen and air to examine the effect of atmospheric change on thermal decomposition of these complexes. Changing of the atmosphere does not cause any measurable changes in the decomposition of complexes. However, as indicated by thermoanalytical techniques, the thermal stability of present complexes decreases in the order: [Cr(pn)2](ClO4)2>[Mn(pn)2](ClO4)2>[Zn(pn)2](ClO4)2>[Ni(pn)2](ClO4)2>[Cu(pn)2](ClO4)2. Isothermal thermogravimetry, over the temperature range of decomposition has been done for all the complexes. An analysis of the kinetics of thermal decomposition was made using a model fitting procedure as well as an isoconversional method, independent of any model. The results of both kinetic approaches have been discussed critically. The explosion delay (D E) was measured to investigate the trend of rapid thermal analysis.

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Abstract  

The sum peak method has been applied to electron capture probability changes to the 1086 keV level in the decay of152Eu in the different environments, e.g. ethylenediaminetetraacetic acid (EDTA), bovine serum albumin (BSA) and hydrochloric acid (HCl). An attempt is also made to determine the effect of chemical environment on the directional correlation coefficient of the 1409–122 keV - cascade in152Eu 152Sm decay. A change of G22 is found in the different chemical forms.

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