Attitude toward Daytime Nap in the Aged

This study investigated attitudes toward daytime nap on the 470 aged people (M=73.7 years old) by two measures. One measure was 13 items-scale on an attitude toward positive effects of daytime nap (AE). Another measure was 15 items-scale on an attitude toward napping person (AP). A factor analysis confirmed that AE consists of 3 dimensions of effects of daytime nap : effects on work, physical effects, and psychological effects, and that AP consists of 2 dimensions of beliefs about napping person : belief about taboo and belief about rest. The survey results clearly show that most of the aged people have positive attitudes toward daytime nap. So far, it has been proposed that there are social pressures which inhibit daytime nap in Japanese country and that daytime nap in the aged people is harmful to their health. The results of present study were, however, inconsistency with these previous issues

Relationship of daytime activity and nocturnal sleep in the elderly

This study investigated the relationship between the level of daytime activities and nocturnal sleep in the elderly using the wrist actigraph and ambulatory polysomnograph (PSG) system. Ten male and ten female subjects (mean age ± SE=73.2 ± 1.62 years; range 65-81 years) participated in this study. The level of daytime activity was positively correlated with the sleep efficiency of the subsequent night. Based on the amount of daytime activity level on the PSG recording night, 6 participants were selected as the high activity group, and other 6 participants selected as the low activity group. The duration of slow wave sleep (SWS) was significantly longer for high activity group than those for low activity group. Moreover, the duration of wake after sleep onset was longer for low activity group than those for high activity group. The results imply that increment the time of physical activities may improve the quality of nocturnal sleep for the elderly subjects

Rim Breakups of Impacting Drops on a Superhydrophobic Surface and a Superheated Surface

The rim breakup of an impacting drop is experimentally investigated by comparing the impacts on superheated and superhydrophobic surfaces. The objective of the present study is to experimentally examine whether the Bo = 1 criteria holds for the rim breakups of drops impacting on the surfaces. A transparent sapphire plate was heated to achieve the Leidenfrost impact, which enables us to observe with a high-speed camera from below. The characteristics of the rim breakup were evaluated quantitatively using a particle tracking velocimetry method for both the rim and the drops generated. As a result, we clarified that Bo of the rim increases in the spreading phase and marks the highest value of 0.5 on a superheated surface, which is smaller than that on a pillar, where Bo ≈ 1. On a superhydrophobic surface, the highest Bo was 1.2, which is smaller than that on a wettable solid surface, 2.5, but close to the value on a pillar. We also revealed that diameters of generated drops collapse on a master curve when plotted as a function of pinch-off time for both the impacts on superheated and superhydrophobic surfaces

Rim Breakups of Impacting Drops on a Superhydrophobic Surface and a Superheated Surface

The rim breakup of an impacting drop is experimentally investigated by comparing the impacts on superheated and superhydrophobic surfaces. The objective of the present study is to experimentally examine whether the Bo = 1 criteria holds for the rim breakups of drops impacting on the surfaces. A transparent sapphire plate was heated to achieve the Leidenfrost impact, which enables us to observe with a high-speed camera from below. The characteristics of the rim breakup were evaluated quantitatively using a particle tracking velocimetry method for both the rim and the drops generated. As a result, we clarified that Bo of the rim increases in the spreading phase and marks the highest value of 0.5 on a superheated surface, which is smaller than that on a pillar, where Bo ≈ 1. On a superhydrophobic surface, the highest Bo was 1.2, which is smaller than that on a wettable solid surface, 2.5, but close to the value on a pillar. We also revealed that diameters of generated drops collapse on a master curve when plotted as a function of pinch-off time for both the impacts on superheated and superhydrophobic surfaces