Explicit free subgroups of

In this note for any finite , we give an explicit free subgroup of rank of the groups of ordered permutations of the reals for which the proof that the subgroup is free is elementary. Moreover, this example naturally generalizes to the group .

     

Analytical methods for the environmental quantification of uranium isotopes: Method of validation and environmental application

The use of depleted uranium in military ordinance has led to an increasing need to determine isotope-specific uranium concentrations in environmental matrices. To this end, gamma-ray spectrometry, ICP-MS and INAA methods have been validated, in accordance with the ISO 17025 standard. Reporting limits of 0.21 (U-235) and 0.91 (U-238) ng/L were obtained by ICP-MS analysis of water. Higher reporting limits were obtained for INAA (U-238 only) validations of water and gamma-ray spectrometric validations of soil and water. Accredited methods have been used to determine uranium concentration and isotope ratio of samples obtained from the Defence Research and Development Canada Valcartier, Quebec.     

Environmental radionuclide monitoring programme

As part of Canada’s international commitment for the collective defence of allied nations, nuclear submarines from allied nations berth at three approved locations on both east and west coasts of Canada. In the case of any untoward event, a nuclear emergency response (NER) organisation has been established. In addition, regular sampling of the coastal environment is undertaken as the Environmental Radionuclide Monitoring Programme (ERMP). This continuing effort consists of a long-term programme and a visit sub-programme. In the former, samples are ocean sediment, seawater, aquatic plants and sealife; in the latter, samples are seawater taken before, during and after each visit. Samples are collected according to a prescribed schedule and follow a chain of custody to the accredited laboratory in the SLOWPOKE-2 Facility at RMC. Counting and analyses are done by gamma-ray spectroscopy by the Analytical Services Group (ASG) at RMC. With most results below detection limit, the safety of the NPV visits is assured.     

A set-up, calibration, acquisition and analysis program (SCAAP) for gamma-ray spectroscopy

A computer program entitled SCAAP (Set-up, Calibration, Acquisition and Analysis Program) has been designed to make gamma-ray spectroscopy easily useable by staff in laboratories at the Slowpoke-2 Facility at RMC and in support of the Canadian Forces Nuclear Emergency Response Teams (NERTs). The former group utilises gamma-ray spectroscopy for neutron activation analysis (NAA), while the latter may need to have inhalation dose rates calculated. The intent of this program, written using Microsoft Visual Basic, is to provide a simplified interface between the operator and the spectroscopy equipment and to provide the calculations necessary to produce results quickly. There are five sections (Setup, Calibrate, Acquire, Analyse and NAA) of which the first four are linked. In these sections, a checklist of procedures is presented and automated for the user to set up and calibrate the equipment and then to analyse spectra to provide various dose rates. In the unlinked section, NAA, gamma-ray spectra are analysed to provide elemental concentrations in samples.