ABSTRACT
Research on mental health states involves paying increasing attention to changes in daily life. Researchers have attempted to understand such daily changes by relying on self-reporting through frequent assessment using devices (smartphones); however, they are mostly focused on a single aspect of mental health. Assessing the mental health of a person from various perspectives may help in the primary prevention of mental illness and the comprehensive measurement of mental health. In this study, we used users' smartphone logs to build a model to estimate whether the scores on three types of questionnaires related to quality of life and well-being would increase compared to the previous week (fluctuation model) and whether they would be higher compared to the average for that user (interval model). Sixteen participants completed three questionnaires once per week, and their smartphone logs were recorded over the same period. Based on the results, estimation models were built, and the F-score ranged from 0.739 to 0.818. We also analyzed the features that the estimation model emphasized. Information related to "physical activity," such as acceleration and tilt of the smartphone, and "environment," such as atmospheric pressure and illumination, were given more weight in the estimation than information related to "cyber activity," such as usage of smartphone applications. In particular, in the Positive and Negative Affect Schedule (PANAS), 9 out of 10 top features in the fluctuation model and 7 out of 10 top features in the interval model were related to activities in the physical world, suggesting that short-term mood may be particularly heavily influenced by subjective activities in the human physical world.
ABSTRACT
A synergistic enhancement in oxygen release/storage performance was achieved with composites formed between CeO2 as an oxygen gateway and La2O2SO4 as an oxygen reservoir. CeO2 smoothly transfers oxygen atoms between La2O2SO4 and the gas phase, whereas La2O2SO4 stores a large amount of oxygen. The composite materials exhibited enhanced anaerobic CO oxidation and reversible oxygen storage in the presence of impregnated Pt catalysts as compared to their individual constituents (Pt/CeO2 and Pt/La2O2SO4). In situ X-ray diffraction and Raman experiments demonstrated that CeO2 significantly accelerated the redox reaction between La2O2SO4 (S6+) and La2O2S (S2-), while preserving its structure. The reaction between CO and CeO2/18O-labeled La2O2SO4 composites suggested that CO mainly reacted with the lattice oxygen atoms of CeO2, and the resulting oxygen vacancies were subsequently filled with oxygen atoms supplied by La2O2SO4. This oxygen gateway effect of CeO2 greatly enhanced the oxygen release/storage rates of La2O2SO4, while maintaining the high oxygen storage capacity, which is an advanced feature of oxysulfate materials. The synergistic effect is mostly pronounced when the two different oxygen storage materials are in intimate contact to form a three-phase boundary.
