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Surface treatment of a poly(ethylene naphthalate) (PEN) film by atmospheric pulsed microplasma with humid Ar gas was experimentally investigated. A Marx generator with metal–oxide–semiconductor field-effect transistor (MOSFET) switches that generates negative pulses was used for generating microplasma. Hydrophilization was estimated by measuring contact angle before and after the microplasma surface treatment by a remote process. The initial contact angle was about 76°. The minimum contact angle of about 20° was obtained after a treatment, a discharge voltage of -1.3 kV negative pulse, a frequency of 24 kHz, a gas relative humidity of about 60%. Analysis by X-ray photoelectron spectroscopy (XPS) showed a decrease in the C 1s peak corresponding to the C–H bond or C–C bond, and increases in the O 1s peaks corresponding to the C=O bond or O–H bond.

The uncertainty is evaluated of a calibration method allowing the determination of complex sensitivities of accelerometers in an acceleration range of 102 m s-2 to 106 m s-2 and a frequency band of 103 Hz to 104 Hz. The method uses elastic waves in a thin circular bar to generate input acceleration and an optical interferometer to evaluate the input. The uncertainty in the magnitude of the complex sensitivities is estimated to be of the order of 10-2 and that in the phase shift of the order of 10-2 rad, in the frequency range where the accelerometer signal and the interferometer signal have sufficient spectral intensity. Note that this paper deals with a special case of the calibration of a back-to-back accelerometer, in the frequency domain rather than in the time domain.

ABSTRACT--Dynamic response of foil strain gages is investigated in the ranges of up to approximately 300 kHz in frequency, 2000 t~e in strain and 750 s -t in strain rate. Impulsive input is applied to the gages using elastic wave pulses in a circular bar. The input is determined by measuring the velocity of the bar end with a laser interferometer. It was confirmed that deviations from the static gage factors do not exceed -5 percent within the frequency range up to 45 kHz, 110 kHz and more than 290 kHz for 20-mm, 10-mm and 3-mm gages, respectively, and that the gage length is the dominant factor in the gages' frequency characteristics. This paper also mentions self-generated voltages.