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R N Acharya

Publications and source records attributed to R N Acharya.

5 recordsLinked to original sources
PubMed2002

Validation of a neutron activation analysis method using k0-standardization.

A neutron activation analysis method using k0-standardization has been adopted for multielement analysis using our research reactors. Gold has been used as the comparator. The input parameters, used for calculation of elemental concentration, such as subcadmium to epithermal neutron flux ratio (f), the epithermal neutron flux shape factor (alpha), and the absolute efficiency of the detector (epsilon) have been determined. The values of k0-factors and Q0 (the ratio of resonance integral to thermal neutron cross section) have been taken from the literature. The validity of applying this method in our laboratory is evaluated by analyzing the elemental concentrations with respect to the certified values in eight reference materials of different origin obtained from USGS, IAEA and NIST. The percent deviation of the measured elemental concentrations are found to be within +/- 15% to that of the certified values whereas the percent relative standard deviation ranged from 2% to 10% for most of the elements analyzed.

Journal Article↗
PubMed2002

Heavy metal concentration and distribution in a dated sediment core of Nainital Lake in the Himalayan region.

The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years.

Environmental Monitoring↗
PubMed2001

Use of gold as monostandard for the determination of elemental concentrations in environmental SRMs and Ganga river sediments by the k0 method.

Instrumental neutron activation analysis (INAA) using the k0 method by employing gold as monostandard has been used for the determination of 18 elements (As, Ba, Br, Cl, Cr, Co, Cs, Dy, Fe, Hf, Ga, In, La, Mn, Na, Rb, Sc and Th) in standard reference materials (SRMs) of environmental origin and four sediment samples collected from the Ganga river in northern parts of India. Data obtained for SRMs agree within +/- 5-10% with the certified values for most elements. Merits and demerits of the k0 method are discussed. An attempt has been made to identify the sources of heavy metal pollutants in the sediment samples and study the mobility pattern for toxic heavy metals originating from the tanneries along with the river flow.

Journal Article↗
PubMed2000

Multielement analysis in cereals and pulses by k0 instrumental neutron activation analysis.

The concentrations of some elements in a few varieties of cereals and pulses are determined by Instrumental Neutron Activation Analysis using a single comparator method (k0-standardised NAA method). A total of 15 elements are measured. The method was validated by analysing the Standard Reference Material (SRM-1571) of NIST; the results are within +/-10% of the reported values for the majority of the elements. The measured concentrations of major and minor elements are analysed in terms of the average intake of mineral content and the role of these elements in terms of the nutritional value.

Diet↗