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- Author or Editor: S. J. Smith x
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Abstract
Experiments to determine the effect of surface area, head space, and containment on liquid gun propellant degradation at temperatures of 100 and 148°C were conducted. The conclusions from these tests are that an increased surface area in LP containment can significantly increase the rate of LP decomposition. The head space is not a significant factor in altering the rate of degradation, but if the gaseous products are allowed to escape, the degradation rate is significantly lowered.
Abstract
Since the accidental loss of four nuclear weapons by a B-52 at Thule Airbase, Greenland in 1968, the marine environment at Thule has showed enhanced levels of Pu and Am. Most of the activity is confined to the benthic environment within a distance of 50 km from the crash site of the B-52. Samplings of sediments, benthos, seaplants, fish, and water have been carried out in 1968, 1970, 1974, 1979, and in 1984. The study presented herein intends to answer the following questions: What is the mean residence time of these transuranics in the benthic communities? Do Pu and Am behave differently in the environment?
Abstract
Quantitative measurement of fission and activation products resulting from neutron irradiation of fissile materials is of interest for applications in environmental monitoring, nuclear waste management, and national security. Based on established separation processes involving co-precipitation, solvent extraction, and ion-exchange and extraction chromatography, we have optimized a proposed sequence of separation steps to allow for the timely quantification of analytes of interest. We have recently evaluated this scheme using an irradiated sample to examine the adequacy of separations for measurement of desired analytes by gamma spectrometry. Here we present the radiochemical separations utilized and the yields and purity obtained.
Abstract
Background and aims: Slot machines are a pervasive form of gambling in North America. Some gamblers describe entering “the slot machine zone”—a complete immersion into slots play to the exclusion of all else. Methods: We assessed 111 gamblers for mindfulness (using the Mindful Attention Awareness Scale (MAAS)), gambling problems (using the Problem Gambling Severity Index (PGSI)), depressive symptoms (using the Depression, Anxiety, and Stress Scale), and boredom proneness (using the Boredom Proneness Scale). In a counterbalanced order, participants played a slot machine simulator and completed an auditory vigilance task. During each task, participants were interrupted with thought probes to assess whether they were: on-task, spontaneously mind-wandering, or deliberately mind-wandering. After completing each task, we retrospectively assessed flow and affect. Compared to the more exciting slots play, we propose that gamblers may use deliberate mind-wandering as a maladaptive means to regulate affect during a repetitive vigilance task. Results: Our key results were that gamblers reported greater negative affect following the vigilance task (when compared to slots) and greater positive affect following slots play (when compared to the vigilance task). We also found that those who scored higher in problem gambling were more likely to use deliberate mind-wandering as a means to cope with negative affect during the vigilance task. Using hierarchical multiple regression, we found that the number of “deliberately mind-wandering” responses accounted for unique variance when predicting problem gambling severity (over and above depression, mindfulness, and boredom proneness). Conclusions: These assessments highlight a potential coping mechanism used by problem gamblers in order to deal with negative affect.
