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The influence of sample thickness and modulation frequency on the x-ray photoacoustic signal intensity of copper was investigated. The results showed that the photoacoustic signal intensities showed maxima at at the sample thickness close to 10 micrometers for each modulation frequency. The x-ray photoacoustic signal varied by a magnitude of 1.0 when sample thickness was less than or equal to 20 micrometers but varied by only 0.5 when it was larger than 20 micrometers.

The perceptional change of fragrance of essential oils is described in relation to type of work, i.e. mental work, physical work and hearing environmental (natural) sounds. The essential oils examined in this study were ylang ylang, orange, geranium, cypress, bergamot, spearmint and juniper. In evaluating change in perception of a given aroma, a sensory test was employed in which the perception of fragrance was assessed by 13 contrasting pairs of adjectives. Scores were recorded after inhaling a fragrance before and after each type of work., and the statistical significance of the change of score for 13 impression descriptors was examined by Student's t -test for each type of work. It was confirmed that inhalation of essential oil caused a different subjective perception of fragrance depending on the type of work. For example, inhalation of cypress after physical work produced a much more favorable impression than before work, in contrast to orange, which produced an unfavorable impression after physical work when compared with that before work. For mental work, inhalation of juniper seemed to create a favorable impression after work, whereas geranium and orange both produced an unfavorable impression then. From these studies, together with those conducted previously with lavender, rosemary, linalool, peppermint, marjoram, cardamom, sandalwood, basil and lime, we thus concluded that the sensory test described here might serve not only as a screening test for efficacy of aroma but also as a categorized table for aroma samples which can act as a reference to each other. [ABSTRACT FROM AUTHOR]

Transient heat generation by absorption of x-ray and far-infrared beams was successfully detected by a photoacoustic detection method. The photoacoustic detectors of solid and gas phase for x rays and of solid materials for far-infrared light are shown together with its instrumentation. The x-ray photoacoustic signal showed a linear dependence on the ring current and ionization chamber current, both of which are the measure of the photon flux. Typical examples of photoacoustic signals were shown, and their characteristics were briefly discussed in relation to the physicochemical properties of the samples. The potential use of this detection method is discussed. [ABSTRACT FROM AUTHOR]

A proposed photoacoustic imaging by a scanning focused x-ray beam has been investigated. The experimental setup and its current performance are shown using model samples. The current spatial resolution, 0.5 mm, by this method is limited by detector sensitivity or photon flux. For the study of the nondestructive three-dimensional analysis of atomic components, the computer system has the commands to estimate the average values of the signal amplitude and phase at the desired areas. Layered samples were measured for demonstration. [ABSTRACT FROM AUTHOR]

The instrumentation for the photoacoustic EXAFS experiment detailed here is under development at the Photon Factory. In the experimental setup, simultaneous detection of the absorption spectra in addition to the photoacoustic measurement was useful for confirmation of this phenomena and for data correction. The current detection limit of this system is not sufficient for application to a wide variety of samples. Several ways for improvement of the quality of the spectra were carried out and the results were discussed. [ABSTRACT FROM AUTHOR]

Examines the use of a photoacoustic detector in determining the hard x-ray absorption spectroscopy of copper oxide and CU[sub 2]O. Use of the synchrotron radiation in the photoacoustic detector; Effects of the rotating lead plate chopper on the x-ray beam intensity; Method in measuring the absorption spectrum simultaneously.