Authors:Sujit Bhattacharya, Chandra Pal and Jagdish Arora
In an earlier study, a methodology was described for identifying Frontier Areas in a research field, i.e., areas which experienced in a particular time period significant increase in research output in comparison to a preceding time period. The application of this methodology was shown by identifying Frontier Areas of research in Physics in 1995. Comparison was done with respect to the outputs in different areas in 1990. Profiles of countries active in the identified Frontier Areas were then constructed.In this paper, attempt is made to reveal the active research topics/themes within these Frontier Areas in 1990 and 1995. The active research topics, which are uncovered, are classified as Frontier Topics. Countries active in these frontier topics are distinguished in each time period. Association among countries and Frontier Topics are observed using the multivariate technique of correspondence analysis. Dynamics are observed by analysing the changes in the profiles of the countries in the two time periods. Results and implications of this study for decision-making and as a policy tool are highlighted.
Authors:D. Chowdhury, S. Saha, Sujit Pal and P.K. Mathur
The rare earth elements (REE), Pr, Sm, Eu, Gd, Ho, Er and Tm have been determined by charged particle activation analysis using 40 MeV a-particles through radiochemical approach. The radiochemical separation of REE as a group has been carried out from the bulk matrix. It has been shown from the theoretical computation that the products obtained from (a,xn) reactions (x = 1, 2, 3) are more suitable compared to those from (a,pyn) reactions (y = 0, 1, 2) due to the former having higher cross section (of the order of thousand millibarns).
Authors:D. Chowdhury, J. Arunachalam, Rakesh Verma, Sujit Pal and S. Gangadharan
40 MeV -particles have been used to determine oxygen impurity at ppm levels in silicon, copper, and stainless steel, through the radiochemical separation of18F from the matrix. The separation of18F has been carried out by two techniques, viz.(1) distillation of H2SiF6 and (2) precipitation of KBF4 and some modification has been applied in the separation, depending on the nature of interferences from the matrix. Instrumental approach was also carried out to determine the oxygen impurity at 100 ppm in Si matrix because this approach is not possible in Cu and stainless steel samples due to matrix activity.