Investigation of charge trapping in thin Kapton® polyimide films by means of photo-stimulated discharge spectroscopy
Photo-stimulated discharge-current spectroscopy was performed on 50 μm Kapton® 200HN polyimide thermo- and photoelectrets formed in the temperature range between −40ºC and +130ºC. Films were either charged in the DC electric field of 20 MV/m or photo-charged by illumination with light at the wavelength of 420 nm under the electric field of the same strength. Photocurrent spectra scanned in the wavelength interval 600–350 nm demonstrate a pronounced peak at approximately 470 nm revealing the presence of one charge-trapping level. The long-wavelength cut-off of the peak is at 550 nm corresponding to 2.3 eV trap depth.
Observation of charge compensated polarization zones in polyvinylindenfluoride (PVDF) films by piezoelectric acoustic step wave response
A high resolution (2 μm) acoustic step-wave probing techniques has been developed to investigate the inhomogeneous distribution of the piezoelectric response of incompletely corona poled 85 μm thick PVDF films. We observe persistent polarization zones or layers of 20–40 μm width within the films which are electrostatically compensated by charge accumulation at the polarization zone boundaries. The zone development is explained by charge-trapping in proportion to polarization.
[Effects of dance exercise on exercise intention and exercise-related affect of postmenopausal women].
PURPOSE
A dance exercise program was performed to investigate the effects of exercise on exercise intention and exercise-related affect as these are important determinants of exercise behavior.


METHOD
The subjects were overweight (23< or =BMI< or =25) or obese (BMI> or =25) postmenopausal women (n=14), who participated in an exercise program from May, 2003 through November, 2003 at one public health center located in Kyong-gi Province. Data was analyzed with an SAS PC program.


RESULT
Exercise intention was significantly increased after the exercise program (t=-2.24, P=0.04). Exercise-related affect was also increased, but there was no statistically significant change (t=1.81, P=0.09).


CONCLUSION
This study suggests that exercise participation can increase the level of future exercise behavior by increasing exercise intention and exercise-related affect.