Separation and quantification of 238U, 232Th and rare earths in monazite samples by ion chromatography coupled with on-line flow scintillation detector.
An alternative procedure has been described for efficient separation and quantitative determination of uranium (U), thorium (Th) and rare earth elements (REEs) in monazite mineral by high performance ion chromatographic system (IC). Different variables affecting the distribution coefficient, the retention and hence separation efficiency such as eluent flow rate and concentrations of HCI and ammonium sulfate (NH4)2SO4 containing the mobile phase were studied. The developed separation protocol of U, Th and REEs was optimized using an Ion Pac CS5 separation column followed by post-column derivatization reaction with Arsenaso III and UV-VIS spectrophotometric detection. Comparative evaluation of U, Th and REEs concentration in monazite mineral was demonstrated using two different on-line detection modes including flow through cell scintillation detector (FSD) and UV-VIS spectrophotometer. Response of the FSD was found to be linear over the full range of activities investigated (4-100 Bq). The lower limits of detection (LLD) for the investigated radionuclides were 3.0+0.1 Bq for 238U and 6.0 +/- 0.1 Bq for 232Th. The detection of 238U and 232Th by FSD shows good agreement with the corresponding determination by UV-VIS spectrophotometer. The content of ThO2 and U3O8 in monazite sample were found to be 4.7 +/- 0.1% and 0.42 +/- 0.04% using UV-VIS detector and 4.3 +/- 0.1% and 0.45 +/- 0.1% using FSD, respectively.
Alpha-particle spectrometry and its applications
Abstract Alpha-particle spectrometry is a precise and sensitive technique which has many applications in the nuclear-energy field. Using a thin, uniform source with a suitable detector and ancillary electronic equipment, the constituents of a mixture of α-emitting nuclides can be accurately assayed both at activity levels found in the environment and in reprocessing-plant solutions. Factors influencing the achievement of high-quality data and some examples of applications are described.
Responsive Ethics and the War Against Terrorism: A Levinasian Perspective
Realist and liberal understandings of ethics as the dominant approaches to ethics in international relations are unable to respond efficiently to the call of the other in the age of war against terrorism as they revolve around the needs and the interests of the self. Such self-centred understandings of ethics cannot respond to the other ethically and respect the other in its otherness. Therefore, in this work I attempt to develop responsive ethics by drawing on Levinasian ethics which can create the possibilities of concrete non-violent responses to the other in the age of war against terrorism.