Stroboscopic oblique-incidence interferometer for motion visualization of stator of ultrasonic motor.

AbstractThis paper describes a motion-visualization technique for an ultrasonic motor (USM) by using a stroboscopic oblique-incidence interferometer. Characteristics of USM depend on a vibration mode of a stator which is one of main component of USM. Though there are some visualization techniques of its vibrated mode, it is difficult to visualization. Because the surface of the stator is rough for a light. For visualization such a surface, we focused on an oblique-incidence interferometer. The interferometer is well suited to analyze the rough surface because a scattering at the rough surface is reduced by using an oblique-incidence light. Furthermore, for detecting a vibrated surface, a pulsed light synchronized with stator was used as light source. We have succeeded to detect a periodically movement of fringe patterns of the vibrated stator

Fourier Amplitude Spectrum at Arbitrary Points Estimated by Kriging Method

This paper reports a method for estimating an acceleration Fourier amplitude spectrum (FS) on ground surface at arbitrary points using the transfer functions of the surface strata and the observation records of limited number of seismometers. The transfer functions at arbitrary points in Owari-asahi City are estimated by using a modified Kriging method based on the results of the seismic response analysis of the surface strata at 748 boring points using seismic waves on engineering bedrock caused by six earthquake scenarios. The acceleration FS on the surface at 642 boring points inside the city are estimated by using the proposed method based on only 20 observation records on the surface (estimated value). The result is compared to the acceleration FS estimated by the transfer functions and seismic waves on the engineering bedrock from earthquake scenarios at the same boring points (tentative observed value). It is found that the correlation coefficients per frequency between the estimated and tentative observed value at 642 points are no less than 0.5 any earthquake scenario

Phase-Modulation Fluorometer Using a Phase-Modulated Excitation Light Source

We propose a phase-modulation fluorometer (PMF) with a light-emitting diode (LED) or a laser diode (LD) used as an excitation light source (ELS) that is driven in the phase-modulation (PM) mode. The PM-ELS generates many frequency sidebands that spread in the vicinity of carrier frequency fc with the interval of modulation frequency fm depending on the maximum phase deviation Δφ . The scheme enables us to derive fluorescence lifetime values of a multicomponent sample at one time. We show a typical numerical simulation result for explaining the principle of operation. To demonstrate the effectiveness of the proposed PMF, we have measured fluorescence lifetimes of three kinds of inorganic fluorescent glasses and that of a mixture solution of 1×10−6M rhodamine 6G and 1×10−6M coumarin 152 in ethanol with a volume ratio of 1 :1

Application of Scan-less Two-Dimensional Confocal Microscopy Based on a Combination of Confocal Slit With Wavelength/Space Conversion

Confocal laser microscope (CLM) has been widely used in the fields of the non-contact surface topography, biomedical imaging, and other applications, because the confocality gives two-dimensional (2D) optical-sectioning or three-dimensional (3D) imaging capability with the depth selectivity. Combination of line-focused CLM with one-dimensional (1D) spectral encoding CLM enables us to obtain the 2D confocal image without the need for the mechanical scanning. So-called scan-less 2D CLM is a unique imaging modality, however, there are no attempts to apply for practical application. In this paper, we constructed scan-less 2D CLM with the image acquisition time of 0.23 ms, the lateral resolution of 1.2 µm, the depth resolution of 2.4 µm, and apply it for different kinds of application to evaluate its practical potential

Species-independent detection of RNA virus by representational difference analysis using non-ribosomal hexanucleotides for reverse transcription

A method for the isolation of genomic fragments of RNA virus based on cDNA representational difference analysis (cDNA RDA) was developed. cDNA RDA has been applied for the subtraction of poly(A)(+) RNAs but not for poly(A)(−) RNAs, such as RNA virus genomes, owing to the vast quantity of ribosomal RNAs. We constructed primers for inefficient reverse transcription of ribosomal sequences based on the distribution analysis of hexanucleotide patterns in ribosomal RNA. The analysis revealed that distributions of hexanucleotide patterns in ribosomal RNA and virus genome were different. We constructed 96 hexanucleotides (non-ribosomal hexanucleotides) and used them as mixed primers for reverse transcription of cDNA RDA. A synchronous analysis of hexanucleotide patterns in known viral sequences showed that all the known genomic-size viral sequences include non-ribosomal hexanucleotides. In a model experiment, when non-ribosomal hexanucleotides were used as primers, in vitro transcribed plasmid RNA was efficiently reverse transcribed when compared with ribosomal RNA of rat cells. Using non-ribosomal primers, the cDNA fragments of severe acute respiratory syndrome coronavirus and bovine parainfluenza virus 3 were efficiently amplified by subtracting the cDNA amplicons derived from uninfected cells from those that were derived from virus-infected cells. The results suggest that cDNA RDA with non-ribosomal primers can be used for species-independent detection of viruses, including new viruses

Multicascade-linked synthetic wavelength digital holography using an optical-comb-referenced frequency synthesizer

Digital holography (DH) is a promising method for non-contact surface topography because the reconstructed phase image can visualize the nanometer unevenness in a sample. However, the axial range of this method is limited to the range of the optical wavelength due to the phase wrapping ambiguity. Although the use of two different wavelengths of light and the resulting synthetic wavelength, i.e., synthetic wavelength DH, can expand the axial range up to a few tens of microns, this method is still insufficient for practical applications. In this article, a tunable external cavity laser diode phase-locked to an optical frequency comb, namely, an optical-comb-referenced frequency synthesizer, is effectively used for multiple synthetic wavelengths within the range of 32 um to 1.20 m. A multiple cascade link of the phase images among an optical wavelength (= 1.520 um) and 5 different synthetic wavelengths (= 32.39 um, 99.98 um, 400.0 um, 1003 um, and 4021 um) enables the shape measurement of a reflective millimeter-sized stepped surface with the axial resolution of 34 nm. The axial dynamic range, defined as the ratio of the maximum axial range (= 0.60 m) to the axial resolution (= 34 nm), achieves 1.7*10^8, which is much larger than that of previous synthetic wavelength DH. Such a wide axial dynamic range capability will further expand the application field of DH for large objects with meter dimensions.Comment: 19 pages, 7 figure