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  • Author or Editor: R.S. Singh x
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Abstract  

The distribution ratios for the extraction of Zr(IV) by TBP and its binary mixtures with DMSO or Py in n-dodecane in the presence of HNO3, and HClO4 have been determined. Based on stoichiometric and slope analysis methods a possible mechanism for the extraction has been proposed.

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Abstract  

The radiotracer technique has been applied to find the transference number of anion/cation constituents of iodine-alcohols “inner chargetransfer complexes” and it is deduced that the anions are the main charge carriers.

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Abstract  

Sorption behaviour of monovalent Rb+, Tl+ and Ag+ is studied on chromium fericyanide gel. Log Kd vs log concentration plots show that Rb+ and Tl+ are sorbed through ion exchange mechanism in a higher concentration range of ammonium nitrate or nitric acid, whereas the adsorption of Ag+ is irreversible. It was found possible to elute Rb+ and Tl+ on the columns of this gel by 4 mol dm−3 NH4NO3 and 10 mol dm−3 HNO3, respectively. Binary separations of Rb+ and Tl+ from a number of other metal ions were achieved as other ions were found practically unadsorbed on these columns and were eluted with water of pH 2–3. Achieved separations are of radioanalytical and analytical importance.

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β-Galactosidase is an enzyme of commercial importance owing to its multiple benefits. Among all microbial sources, fungal species are of great interest for the production of this enzyme. Thus, the aim of this present work was to optimize the media as well as process parameters to achieve maximum β-Galactosidase production by solid state fermentation using the fungal isolate Rhizomucor pusillus. Various agro-industrial residues were tested for carbon as well as for nitrogen sources. The different process parameters were also studied to observe their effects on β-galactosidase production. Among all screened agro-industrial residues, wheat bran and corn steep liquor had the potential to be used as carbon and nitrogen sources, respectively; whereas MgSO4 was found to be a suitable salt supplement. The optimal process parameters included particle size of 1000 microns, 50% moisture content, pH 5.5, 50 ºC temperature, and 7 days of fermentation.

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Terminal heat referred to as increase in temperature during grain filling, is one of the important stress factors for wheat production and is responsible for decline in wheat production in many environments worldwide. In order to meet the challenges of high temperature ahead of global warming, concerted efforts are needed to evaluate wheat genotypes for heat tolerance and develop genotypes suitable for such stressed environments. Twenty-seven advanced wheat genotypes developed for stress and normal environments by different research centres were evaluated during 2009–10 and 2010–11 under timely sown (normal) and late sown (heat stress) environments. Analysis of variance revealed that the genotypes differed significantly in grain filling duration (GFD), grain growth rate (GGR) and thousand-grain weight (TGW). Out of 27 genotypes, 16 were found to be tolerant for thousand-grain weight under late planting (heat stress) during 2009-10 but only 12 were tolerant during 2010–11. Many of the genotypes registered more reduction in thousand-grain weight during 2010–11 as compared to 2009–10; the temperatures during 2009–10 were higher. The differences in grain filling duration under two conditions during both seasons as well as difference in temperatures during first half of grain filling explain the reduction pattern in the genotypes. GFD had significant negative correlation with temperatures during post heading period and the difference in GFD under two environments had positive correlation with these temperatures. The reduction in GFD had regression of 33.3% on reduction in GGR and reduction in GGR had regression of 41.6% on reduction in TGW genotypes AKW 1071, DBW 17, HS 277, K 7903, K 9107, NW 1014 and RAJ 3765 had less sensitivity to stress environments during both years.

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A study was undertaken to determine the genetics of corn leaf aphid (CLA) resistance in barley under controlled conditions with artificial inoculation at adult plant stage. Inheritance of CLA resistance was investigated in five resistant barley genotypes (EB921, EB2507, Manjula, DL529 and K144) in crosses with susceptible parent Alfa93 in F1, F2, F3 and backcross (BCF1) generations. The aphid inoculation was done using the brush method as well as the detached leaf method. Individual plants were classified in resistant, moderately resistant, susceptible and highly susceptible categories base on number per shoot as well as multiplication of CLA on any of the fresh, young leaf. The plants scored as resistant or moderately resistant were observed twice more at 10 days interval to confirm their reaction. Resistance was governed by a single dominant gene in EB921, DL529 and K144, while it was monogenic recessive in Manjula and EB2507. These diverse sources may be used in breeding for CLA resistance in barley improvement programme.

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Apart from the issue of sustainability and resource drain, the yield plateau in the rice-wheat cropping system of south-east Asia is the major area of concern. Realizing that genetic gain is a remote possibility, efforts are directed to management options for yield improvement. Adequate crop nutrition in general and nitrogen (N) in particular figure at the top among various management issues. A survey was conducted covering the rice-wheat belt of Haryana state, India representing Trans-Gangetic plains to know about on-farm practices related to N management in wheat crop and how far it deviates from the blanket recommendations given by State Agricultural Universities. The survey revealed that about 42.7 per cent farmers used either recommended dose of N (150 kg/ha) or less and others used higher dose of N. Positive correlation between the size of the farm and extent of N used was established. Whenever the farmers tended to use higher dose of N, they also tended to partition it in more number of splits (up to 3 splits, excluding basal application) staggering upto 54 days after sowing (DAS) as against the recommended practice of two splits (including basal application) within 35 DAS. The study confirmed deviation from the recommended practices of N management but major revelation came about reverse gap holding that the practice of N management in wheat crop being followed by the farmers is better in terms of grain yield. The NPhysical optimum and NEconomic optimum exceeded the current use (165.7 kg/ha) and recommended levels. This study suggests a fit case for the upward revision of recommended dose of N in wheat crop involving no element of risk as arising from aggravated problem of insect pest and disease complex. Nearly half of the farmers use either recommended dose of N or less than that and it is here, where opportunity lies in augmenting the wheat productivity by enhancing the existing level of N use.

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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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