Plasma window performance and scaling for an accelerator-based neutron source.

A "plasma window" was developed for use with a SHINE accelerator-based neutron source. In this work, the design of the plasma window is presented along with results demonstrating successful operation in deuterium over a range of aperture diameters (5-12 mm), gas flow rates (3.5 to 12.5 slm), and input powers (10-55 kW). An empirically determined relationship between the aperture diameter, deuterium gas flow rate, input power, and plasma window pressure differential is also presented.

Understanding the Dependence of Nanoparticles Magnetothermal Properties on Their Size for Hyperthermia Applications: A Case Study for La-Sr Manganites.

Magnetic oxides are promising materials for alternative health diagnoses and treatments. The aim of this work is to understand the dependence of the heating power with the nanoparticle (NP) mean size, for the manganite composition La0.75Sr0.25MnO3 (LSMO)-the one with maximum critical temperature for the whole La/Sr ratio of the series. We have prepared four different samples, each one annealed at different temperatures, in order to produce different mean NP sizes, ranging from 26 nm up to 106 nm. Magnetization measurements revealed a FC-ZFC irreversibility and from the coercive field as function of temperature we determined the blocking temperature. A phase diagram was delivered as a function of the NP mean size and, based on this, the heating mechanism understood. Small NPs (26 nm) is heated up within the paramagnetic range of temperature (T>Tc), and therefore provide low heating efficiency; while bigger NPs are heated up, from room temperature, within the magnetically blocked range of temperature (TT>TB), for intermediate mean diameter size of 37 nm, with maximum efficiency of heat transfer.

Is motivation for marathon a protective factor or a risk factor of injury?

This research investigated whether and how self-determined motivation predicts perceived susceptibility to injury during competition (marathon). Two correlational studies including 378 (Study 1) and 339 (Study 2) marathon runners were conducted. Participants filled out a questionnaire the day before the race measuring self-determined motivation, perceived susceptibilities to marathon-related injury and to keep running through pain, and control variables. Study 1 showed that self-determined motivation was negatively related to perceived susceptibility to marathon-related injury. Study 2 replicated this finding and showed that this relationship was partially mediated by perceived susceptibility to keep running through pain during the race. Moreover, results indicated that the predictive role of self-determination was mostly driven by controlled forms of motivation, and more particularly external regulation. These results suggest that self-determined motivation for sport is a protective factor of injury.

Testing the effect of text messaging cues to promote physical activity habits: a worksite-based exploratory intervention.

This study aims to test the efficacy of text messaging cues (SMS) to promote physical activity (PA) habit formation in the workplace. Employees (N = 49; 28 females and 21 males, Mage = 47.5 ± 8.29 years) were randomized into two parallel groups: a PA group enrolled in a 28-week supervised PA program and a PA+SMS group enrolled in the same PA program with text messaging cues received before their PA sessions. The exercise habit was assessed every week from self-reports on an online application. PA maintenance and several physical fitness measures were also assessed prior to and after the intervention to evaluate its general impact. Mixed model analysis of the 603 observations indicated a small but significant effect of the SMS cues on the speed at which participants engaged in PA behaviors, as the significant interaction effect revealed that the slope of the exercise habit over time was slightly steeper in the PA+SMS group (B = 0.0462, P = 0.0001) than in the PA group (B = 0.0216, P = 0.01). SMS delivery had a marginal effect on the maintenance of PA behaviors 1 year after the intervention. The results suggest that text messaging can help to form PA habits at the workplace and might facilitate long-term maintenance of PA behaviors.

[Risk assessment of soil contamination in a residential area: the importance and role of human biological monitoring--a case report]. / Gefährdungsabschätzung von Bodenverunreinigungen in einem belasteten Wohngebiet: Bedeutung und Funktion des Human-Biomonitoring -- ein Fallbeispiel.

BACKGROUND AND PURPOSE: High levels of arsenic, cadmium, mercury and polychlorinated dibenzodioxins and dibenzofuranes (PCDD/PCDF) were detected in the soil of a residential area located at the river Elbe near Hamburg (Germany). Soil contamination resulted from sediments from the Hamburg harbour and from the Elbe that were deposited in this area up to the late 1950ies. The objective of this study was to evaluate whether the soil contamination in this area is associated with increased levels of arsenic, heavy metals and PCCD/PCDF in the blood and urine of selected residents living on highly contaminated grounds. RESULTS: The blood levels of lead and PCDD/PCDF and the urine levels of arsenic, cadmium and mercury that were measured in 29 residents living on highly contaminated grounds were not elevated in relation to a control group. All individual values were in the range of the background exposure levels of the general population. There were no signs of an increased additional exposure related to soil contamination. CONCLUSIONS: Based on the results of this study it was agreed to refrain from an expensive redevelopment of this area. As a preventive measure some recommendations were given to the residents to minimize possible exposure to soil contaminants. Human biological monitoring studies should be an essential part of exposure and risk assessment of soil contaminations in residential areas in future studies and as a basis for adequate risk management.

Interdependence of Na-excretion, plasma electrolytes, plasma volume and renal Na-K-ATPase-activity in hypertensive rats.

Hypertensive Goldblatt-rats have higher than normal Na-appetite and an enhanced Na-output. They have normal plasma Na- and K-concentration and kidney weight but a significantly reduced plasma volume. The amount of renal membrane protein and the renal Na-K-ATPase-activity of hypertensive rats was found to be significantly below that of controls. In order to evaluate the role of Na-appetite, Na-excretion rate and renal Na-K-ATPase-activity in the electrolyte balance, Goldblatt-rats with a stable hypertension and control animals were put for 8 days on a Na-free diet. Na-excretion rate of control rats reached a minimum (13 muEq/100 g x 24 hr) within 5 days and was maintained on this level up to the end of the experiment. Na-free diet did not alter either the kidney weight or the amount of membrane protein of the animals. However, in salt-free fed control rats total renal Na-K-ATPase-activity was found elevated by about 10% as compared to animals maintained on normal diet. Goldblatt-rats continuously excreted significantly higher amounts of Na (35 muEq/100 g x 24 hr), had sharply reduced plasma volume and plasma Na- concentration. The renal Na-K-ATPase-activity should no adaptation in gold blatt-rats. In all animals studied the rate of Na-excretion showed a close indirect correlation with the renal Na-K-ATPase-activity. It is concluded, that Goldblatt-rats depend on dietary Na to a higher extent than controls because of their reduced capacity to retain Na. The increased Na-appetite of hypertensive rats is a factor secondary to Na-loss.