Contaminant removal from enclosed atmospheres by regenerable adsorbents

A system for removing contaminants from spacecraft atmospheres was studied, which utilizes catalyst-impregnated activated carbon followed by in-situ regeneration by low-temperature catalytic oxidation of the adsorbed contaminants. Platinum was deposited on activated carbon by liquid phase impregnation with chloroplatinic acid, followed by drying and high-temperature reduction. Results were obtained for the seven selected spacecraft contaminants by means of three experimental test systems. The results indicate that the contaminants could be removed by oxidation with very little loss in adsorptive capacity. The advantages of a catalyst-impregnated carbon for oxidative regeneration are found to be significant enough to warrent its use

A Field Survey of Respiration Rates in Leaves of Arctic Plants

In a survey of several plant species found at Churchill, Manitoba, in the transition zone between the low and subarctic regions, we measured leaf respiration in terms of total respiration and alternative pathway respiration rates. Leaves of arctic plants exhibit higher rates of total respiration and alternative (cyanide insensitive) respiration than temperate species. There is a negative correlation between plant height and alternative pathway activity. Shorter plants have higher rates of alternative pathway respiration. More alternative pathway activity may mean that there is less energy in the form of ATP available for growth. A shorter growth habit keeps these plants in the still air close to the ground. This prevents cooling, water loss and physical damage due to wind abrasion. Thus plants with high rates of alternative pathway respiration may be better adapted to the arctic environment. The alternative pathway respiration of Orchis rotundifolia was shown to be under the influence of the biological clock.Key words: Subarctic, plant respiration, alternative pathway, cyanide insensitivMots clés: subarctique, respiration des plantes, voie alterne, insensible au cyanur

Evaluation of techniques for removal of spacecraft contaminants from activated carbon

Alternative techniques for the regeneration of carbon contaminated with various spacecraft contaminants were evaluated. Four different modes of regeneration were evaluated: (1) thermal desorption via vacuum, (2) thermal desorption via nitrogen purge, (3) in-situ catalytic oxidation of adsorbed contaminants, and (4) in-situ non-catalytic oxidation of adsorbed contaminants

Patient safety in undergraduate radiography curricula : a European perspective

Purpose: To establish an understanding of patient safety within radiography education across Europe by surveying higher education institutions registered as affiliate members of the European Federation of Radiographer Societies (EFRS). Method: An online survey was developed to ascertain data on: programme type, patient safety definitions, relevant safety topics, specific areas taught, teaching and assessment methods, levels of teaching and curriculum drivers. Responses were identifiable in terms of educational institution and country. All 54 affiliated educational institutions were invited to participate. Descriptive and thematic analyses are reported. Results: A response rate of 61.1% (n = 33) was achieved from educational institutions representing 19 countries. Patient safety topics appear to be extremely well covered across curricula, however, topics including radiation protection and optimisation were not reported as being taught at an ‘advanced level’ by five and twelve respondents, respectively. Respondents identified the clinical department as the location of most patient safety-related teaching. Conclusions: Patient safety topics are deeply embedded within radiography curricula across Europe. Variations exist in terms of individual safety topics included, teaching and assessment methods, and the depth in which subjects are taught. Results from this study provide a baseline for assessing developments in curricula and can also serve as a benchmark for comparisons

Positively Biased Appraisals in Everyday Life: When Do They Benefit Mental Health and When Do They Harm It?

To promote optimal mental health, is it best to evaluate negative experiences accurately or in a positively biased manner? In an attempt to reconcile inconsistent prior research addressing this question, we predicted that the tendency to form positively biased appraisals of negative experiences may reduce the motive to address those experiences and thereby lead to poorer mental health in the context of negative experiences that are controllable and severe but lead to better mental health in the context of controllable negative experiences that are less severe by promoting positive feelings without invoking serious consequences from unaddressed problems. In 2 longitudinal studies, individuals in new marriages were interviewed separately about their ongoing stressful experiences, and their own appraisals of those experiences were compared with those of the interviewers. Across studies, spouses\u27 tendencies to form positively biased appraisals of their stressful experiences predicted fewer depressive symptoms over the subsequent 4 years among individuals judged to be facing relatively mild experiences but more depressive symptoms among individuals judged to be facing relatively severe experiences. Furthermore, in Study 2, these effects were mediated by changes in those experiences, such that the interaction between the tendency to form positively biased appraisals of stressful experiences and the objectively rated severity of initial levels of those experiences directly predicted changes in those experiences, which in turn accounted for changes in depressive symptoms. These findings suggest that cognitive biases are not inherently positive or negative; their implications for mental health depend on the context in which they occur