Radiation effects control: Eyes, skin

Adverse effects on the lens of the eye and the skin due to exposure to proton radiation during manned space flight were evaluated. Actual proton irradiation which might be encountered in space was simulated. Irradiation regimes included single acute exposures, daily fractionated exposures, and weekly fractionated exposures. Animals were exposed and then maintained and examined periodically until data sufficient to meet the objective were obtained. No significant skin effects were noted and no serious sight impairment was exhibited

Nanoscale Electrodes by Conducting Atomic Force Microscopy: Oxygen Reduction Kinetics at the Pt|CsHSO_4 Interface

We quantitatively characterized oxygen reduction kinetics at the nanoscale Pt|CsHSO_4 interface at ~150 °C in humidified air using conducting atomic force microscopy (AFM) in conjunction with AC impedance spectroscopy and cyclic voltammetry. From the impedance measurements, oxygen reduction at Pt|CsHSO_4 was found to comprise two processes, one displaying an exponential dependence on overpotential and the other only weakly dependent on overpotential. Both interfacial processes displayed near-ideal capacitive behavior, indicating a minimal distribution in the associated relaxation time. Such a feature is taken to be characteristic of a nanoscale interface in which spatial averaging effects are absent and, furthermore, allows for the rigorous separation of multiple processes that would otherwise be convoluted in measurements using conventional macroscale electrode geometries. The complete current-voltage characteristics of the Pt|CsHSO_4 interface were measured at various points across the electrolyte surface and reveal a variation of the oxygen reduction kinetics with position. The overpotential-activated process, which dominates at voltages below -1 V, was interpreted as a charge-transfer reaction. Analysis of six different sets of Pt|CsHSO_4 experiments, within the Butler-Volmer framework, yielded exchange coefficients (α) for charge transfer ranging from 0.1 to 0.6 and exchange currents (i_0) spanning 5 orders of magnitude. The observed counter-correlation between the exchange current and exchange coefficient indicates that the extent to which the activation barrier decreases under bias (as reflected in the value of α) depends on the initial magnitude of that barrier under open circuit conditions (as reflected in the value of i_0). The clear correlation across six independent sets of measurements further indicates the suitability of conducting AFM approaches for careful and comprehensive study of electrochemical reactions at electrolyte-metal-gas boundaries

Electron energy-loss spectrometry on lithiated graphite

Transmission electron energy-loss spectrometry was used to investigate the electronic states of metallic Li and LiC6, which is the Li-intercalated graphite used in Li-ion batteries. The Li K edges of metallic Li and LiC6 were nearly identical, and the C K edges were only weakly affected by the presence of Li. These results suggest only a small charge transfer from Li to C in LiC6, contrary to prior results from surface spectra obtained by x-ray photoelectron spectroscopy. Effects of radiation damage and sample oxidation in the transmission electron microscopy are also reported

Study of behavioral modifications resulting from exposure to high let radiation

Animal irradiations, behavioral studies, neurological studies, and nuclear medicine studies are discussed

The refugee limbo: negotiating the bar of Australian law

Often refugees and asylum seekers are said to be in some sort of limbo: physical, social, and/or legal. This article picks apart the limbo-concept through the expanded metaphor of the Limbo dance; a performance that illustrates an ‘inner history’ that evolved from the conditions aboard the slave ships of the Middle Passage. ‘Playing‘ the Limbo allows the experiences of the slaves to be reenacted: due to the limited space and terrible conditions, slaves had to arch their backs in order to fit inside the ship’s hulls. They had to remain limber or limba before they could re-emerge on the other side. Likewise, this paper investigates the possibilities of an ‘inner history’ of refugee boat arrivals in Australia. However, it is not suggested that the sorts of limbo that refugees encounter are somehow a game or have a lighter meaning. Refugee Limbo is not simply an empty metaphor for the refugee experience. As such, the Limbo line, bar, and the physical bodies placed under the bar are each considered. Due to the restrictive policies in Australia, there lies a particular essence in refugee character, something which can be identified as ‘limberness’

Boundary Bay ambient monitoring program

Metro Vancouver Regional District’s (MVRD’s) Integrated Liquid Waste and Resource Management Plan (ILWRMP) includes a regulatory requirement to conduct ambient monitoring programs to assess, evaluate and forecast the effects of wastewater and stormwater discharges on the receiving environments. The Boundary Bay Ambient Monitoring Program (BBAMP) was initiated in 2009, in partnership with the Ministry of Environment, municipalities of Surrey, Delta and White Rock. Currently, the City of Surrey conducts monitoring of the upland fresh water conditions in tributaries and rivers that discharge into the bay while Metro Vancouver conducts marine monitoring in the bay. The fresh water and marine monitoring incudes annual water column sampling in both dry weather and wet weather conditions. The marine monitoring also includes sediment sampling twice in a 5-year cycle and biota monitoring once every 5 years. The program objectives are to: provide baseline environmental quality data, characterize changes in water quality parameters, evaluate temporal and spatial trends within the monitoring area, identify changes in parameters that might indicate environmental changes, and act as a measure of performance for MVRD’s ILWRMP. In 2017, Metro Vancouver conducted an overall assessment of BBAMP. The program assessment includes a comprehensive compilation, review and interpretation of all previous results and report findings. In addition, the review includes a critical assessment of the adequacy of MVRD’s BBAMP for achieving the program objectives. This presentation provides an overview of the program assessment report findings and recommendations which include: changes to monitoring parameters and sampling plans, further characterizing the benthic community and strengthening alignment with other programs