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  • Author or Editor: M. Sharma x
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Abstract  

Thorium(IV) reacts with 1-(2-thiazolylazo)-2-naphthol (TAN) in the presence of antipyrine to form a sparingly soluble red-coloured chelate, soluble in 36% methanol (v/v). Complexation takes place instantaneously at pH 2.4–2.8, maintained by glycine buffer. Antipyrine is found to enhance sensitivity of the complex, which is stable for 19 hours. The 12 complex exhibits maximum absorbance at 555 nm, obyes Beer's law in the concentration range from 0.32 to 6.56 g of thorium(IV) per ml, has a molar absorptivity of 3.14·104 dm3/mol–1·cm–1 and a Sandel sensitivity of 7.4 ng·cm–2. The formation constant (log K) is found to be 8.62 and 8.45. Interference of 57 anions and cations in the determination of thorium(IV) has been studied. From ten repeated determinations, the coefficient of variation was found to be ±0.98%. The method was successfully applied for determination of thorium content in a sample of monazite.

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The tartrate monohydrates of Sm(III) and Tb(III), Sm2C12H12O18·H2O and Tb2C12H12O18·H2O, were prepared and characterized on the basis of their elemental analysis and IR spectral studies. The thermal decompositions of these compounds, studied by TG and DSC methods, were found to follow an almost uniform pattern. Decomposition occurs in four steps. The first step involves dehydration, accompanied by partial decomposition to the oxalate, followed by conversion to the carbonate. The ultimate product in each case is the oxide M2O3, whereM=Sm or Tb.

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Abstract  

A complete characterization is given for the unit group U(FS 4) of the group algebra FS 4 of the symmetric group S 4 of degree 4 over a finite field F.

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Abstract  

The paper investigates Indian organic chemistry research activity during 1971–1989 using Chemical Abstracts. It attempts at quantification of national contribution to world efforts, and identify areas of relative strengths and weaknesses. Also models the growth of Indian organic chemistry output to world organic chemistry output as a whole and in sub-fields where the activity index for the world and India are similar.

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Abstract  

Gamma-ray spectroscopy has been widely used in many areas of applied science. We have used the method to compare the137Cs contamination in fungi collected in central Sweden, Ukraine (Kiev region) and southern Ontario, Canada. Mean activities were comparable for Sweden and Ukraine, but were much lower in the North American samples. Many European mushroom species which are considered as prized edibles, contained unacceptably high levels of137Cs (1 kBq/kg) and should not be sold for human consumption. By contrast, no activity in mushrooms collected in Ontario or northern Michigan exceed 1 kBq/kg. The excessive contamination in European mushrooms is primarily due to the Chemobyl reactor accident of 1986. However, our observations suggest that about 20% of the137Cs contamination in the Ukraine is not due to this accident.

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β-Agonists have skeletal muscle specific protein anabolic effects and are also known to cause cardiac hypertrophy. Changed total LDH and its isozymic patterns are conveniently employed for the detection of different pathophysiological states of the tissues. The purpose of this study is to confirm total LDH and its isozymic expression in ventricular tissue and serum in mice following oral administration of single but higher dose of isoproterenol (Iso) and clenbuterol (Cl) (100 mg/kg body wt. and 20 mg/kg body wt., respectively), after 4, 8 and 20 hours of drug administration. Mice heart witnessed increased total LDH levels with time. Serum on the other hand showed decline in total LDH concentrations at the initial points of the drug treatment. No doubt, total LDH expression increased towards 20th h post-drug treatment but this increase is mainly due to anaerobic isozymes, i.e. LDH 4 and LDH 5 . The findings of the present study suggest that tissue damage is definitely caused by two β-agonists after giving single dose for shorter time span (20 hours) and the impact of the damage varies from drug to drug. Increase in total LDH in serum is not due to release from heart but from some other tissues having anaerobic metabolism.

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Research on sugarcane biotechnology began in the 1960s with in vitro culture. Serious efforts to improve sugarcane crops by molecular approaches have commenced only in the past two decades. There is an increasing pressure worldwide to enhance the productivity of sugarcane in order to sustain profitable sugar industries, while there are several diseases attacking sugarcane and reducing the quality of the crop. Biotechnological approaches for sugarcane improvement have been applied in the areas of: (1) cell and tissue culture for rapid propagation genetic transformation and molecular breeding, (2) engineering novel genes into commercial cultivars, (3) molecular diagnostics of sugarcane pathogens, (4) developing genetic maps using molecular marker technology, (5) understanding the molecular basis of sucrose accumulation in the stem, (6) molecular testing of plants for clonal fidelity, (7) variety identification and (8) molecular characterization of various traits. Most of the current research in sugarcane biotechnology is recently focused primarily on transgenic and marker assisted breeding. Advancements have made it possible to sequence the complete genome of increasingly complex organisms and to clone and transfer individual genes to engineer new traits.

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High yielding, stable wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite wheat breeding lines developed by CIMMYT, to analyze their stability for grain yield across diverse environments, and to identify superior genotypes that could be valuable for varietal release. Genetically diverse 196 advanced breeding lines were evaluated across different sites in Afghanistan. Grain yield, days to heading and plant height were analyzed. Genotypic superiority for grain yield was determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed arrays of variation for grain yield in each year, with mean values ranging from 3908 to 7209 kg/ha. A set of 20 experimental genotypes superior to the check based on their high mean yield and stability across environments as assessed by the GGE rank was identified. The most stable high yielding genotypes were HD 2687; Elvia/5/Cndo/R143//Ente/Mexi75/3/AE. sq./4/2*Oci; Quaiu; Whear/Vivitsi//Whear; Kiritati/2*Trch; Waxwing; Munal#1; Whear//Inqalab 91*2/Tukuru and Snb//Cmh79A.955/3*Cno79/3/Attila/4/Chen/A.sq.(Taus)//Bcn/3/2*Kauz. These superior genotypes also had acceptable maturity and plant height. The findings of this study provides information on adaptation of the internationally important wheat genotypes, valuable for wheat improvement program in Afghanistan and its neighbouring countries in West, Central and South Asia.

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