Heating Experiments of the Tagish Lake Meteorite: Investigation of the Effects of Short-Term Heating on Chondritic Organics

We present in this study the effects of short-term heating on organics in the Tagish Lake meteorite and how the difference in the heating conditions can modify the organic matter (OM) in a way that complicates the interpretation of a parent body's heating extent with common cosmo thermometers. The kinetics of short-term heating and its influence on the organic structure are not well understood, and any study of OM is further complicated by the complex alteration processes of the thermally metamorphosed carbonaceous chondrites - potential analogues of the target asteroid Ryugu of the Hayabusa2 mission - which had experienced post-hydration, short-duration local heating. In an attempt to understand the effects of short-term heating on chondritic OM, we investigated the change in the OM contents of the experimentally heated Tagish Lake meteorite samples using Raman spectroscopy, scanning transmission X-ray microscopy utilizing X-ray absorption near edge structure spectroscopy, and ultra-performance liquid chromatography fluorescence detection and quadrupole time of flight hybrid mass spectrometry. Our experiment suggests that graphitization of OM did not take place despite the samples being heated to 900 degrees Centigrade for 96 hours, as the OM maturity trend was influenced by the nature of the OM precursor, such as the presence of abundant oxygenated moieties. Although both the intensity of the 1s-sigma * exciton cannot be used to accurately interpret the peak metamorphic temperature of the experimentally heated Tagish Lake sample, the Raman graphite band widths of the heated products significantly differ from that of chondritic OM modified by long-term internal heating

The purpose and the motivation for future practice of physical activity and related factors in Japanese university students

Purpose: We investigated the purpose and the motivation for the future practice of physical activity and related factors in Japanese university students. Materials and Methods: The participants were 499 university students (407 men and 92 women). Participants were surveyed using an anonymous self-administered questionnaire. Questionnaire items were anthropometrics, current exercise habits, preference for exercise, existence of exercise partners, benefits of exercise, self-efficacy for exercise, and the purpose to be motivated to exercising in the future. Results: The exercise group had higher scores for preference for exercise, exercise partners, self-efficacy for exercise, and benefits of exercise than the non-exercise group. The exercise group also reported being more likely to be motivated to exercise in the future than the non-exercise group. In the exercise group, those who felt benefits of exercise were more likely to be motivated to exercise for enhancement of health, enjoyment, making friends, prevention of illness, and enhancement of competitiveness. In the non-exercise group, those who had a preference for exercise were more likely to be motivated to exercise in the future for enjoyment, prevention of illness, and enhancement of competitiveness. In both the exercise and non-exercise groups, women were markedly more likely to be motivated to exercise in the future for aesthetics. Conclusions: These results indicate that there is a difference in the purpose and the motivation for future practice of physical activity between the exercise group and the non-exercise group as well as between genders

Fine-Bubble–Slug-Flow Hydrogenation of Multiple Bonds and Phenols

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Do Ultrafine Bubbles Work as Oxygen Carriers?

Fine bubbles (FBs) are bubbles with sizes less than 100 μm and are divided into ultrafine bubbles (UFBs, < 1 μm) and microbubbles (MBs, 1–100 μm) depending on their size. Although FB aeration is known as a more efficient way than macrobubble aeration to increase the oxygen level in unoxygenated water, few reports have demonstrated whether dispersed UFBs work as oxygen carriers or not. Furthermore, oxygen supersaturation is one of the attractive characteristics of FB dispersion, but the reason is yet to be revealed. In this study, we evaluated the relationship between the FBs, especially UFB concentration, and oxygen content in several situations to reveal the two questions. The FB concentration and oxygen content were examined using particle analyzers and our developed oxygen measurement method, which can measure the oxygen content in FB dispersion, respectively. First, in the evaluations of the oxygen dispersion from UFBs with respect to the surrounding oxygen level, UFBs did become neither small nor diminish even in degassed water. Second, the changes in UFBs and oxygen content upon storage temperature and the existence of a lid during storage were evaluated, and there was no correlation between them. It means UFBs contribute little to the oxygen content in UFB dispersion. Furthermore, the oxygen content in the UFB dispersion decreased over time identically as that of the oxygen-supersaturated water with little UFBs. Third, we evaluated the relationship between FB concentration and oxygen content during FB generation by measuring them simultaneously. The results showed that dispersed MB and UFB concentrations did not account for the supersaturation of the FB dispersion. From the result, it was revealed that 100–200 nm of UFBs themselves did not work as oxygen carriers, and the oxygen supersaturation in FB dispersions was due to the supersaturated state of dissolved oxygen that was prepared during the FB generation process