Image reconstruction by using the propagation law of mutual intensity

An imaging method for partially coherent objects is proposed by the aid of the propagation law of mutual intensity, and it can be reduced to principles used in holography and radio astronomy if the coherence reaches the both extremes, i.e., perfect coherence and complete incoherence, respectively.     

Comments on speckle interferometry with regard to displacements of the camera during an exposure

Displacements of single-lens-reflex camera, which lead to errors in measuring displacements of an object by speckle interferometry, are studied to make sure that cameras with focal plane shutters displace to some extent, regardless of ways of mounting.     

A miniaturization of the multi-degree-of-freedom ultrasonic actuator using a small cylinder fixed on a substrate

Multi-degree-of-freedom ultrasonic actuator has been studied for robot arms and multidimensional precision table and so on because of its simple structure, silent operation, and holding force. In this study, we aim to miniaturize multi-degree-of-freedom ultrasonic actuator for fabrication on a substrate. This actuator consists of a stainless steel cylinder and a PZT ring. The cylinder is fixed on a substrate and the PZT ring is glued to the substrate near the cylinder. The 1st longitudinal vibration and the 2nd bending vibration are simultaneously excited in the cylinder to make elliptical motion at the top of the cylinder and a ball rotor placed on the cylinder rotates because of the friction force. Length of the cylinder was decided so as to tune the resonance frequency of the 1st longitudinal vibration to the 2nd bending one. Actuator performances are evaluated experimentally using a 14 mm height and 7 mm diameter stainless steel cylinder with a 0.5 mm thickness PZT ring. The rotation about the cylinder axis is tested using the two orthogonal bending vibrations with 90 degrees phase difference. Also, the rotation about horizontal axes were investigated using the combination of the longitudinal vibration and one of two bending vibrations. We measured the rotation speed of a steel ball and obtained 15.8 rps using a 6 mm diameter ball rotor.     

Determination of Interfacial Reaction Parameters in Ion-Association Extraction by Total Reflection Induced Thermal Lens

Studies on adsorption kinetics and reaction mechanism at liquid-liquid interfaces are very important for not only classical solvent extraction analysis but also modern nano-science. For this purpose, we should develop versatile techniques that have in-situ, real time and highly sensitive feature. An interfacial thermal lens (TL) technique has been developed for monitoring the formation of Fe(Ⅱ)-4,7-diphenyl-1,10-phenanthroline (DPP) complex at a benzene-acetate buffer interface.     

Thermoplastic photographic material for vibration measurements by speckle photography

In order to measure vibration amplitudes by speckle photography in quasi real-time, the feasibility of using thermoplastic photographic material for recording a speckle pattern image is studied experimentally to be proved true. An optimum recording condition of the material is also obtained.     

Development of a hand-held sensor probe for detection of sound components radiated from a specific device using surface intensity measurements

In this paper, a hand-held sensor probe is developed for surface intensity measurements. The sensor probe is composed of a 1/2-in. condenser microphone and a lightweight accelerometer of 1 g (=10⁻³ kg) which are connected with a vibration damper made of silicon rubber. The reliable measurement range of the sensor probe is examined and shown to be 100 Hz to7 kHz for sound and vibration. The precision of intensity measurements is confirmed by experiments in noisy environment. The precision is shown to be less than 3 dB for a random noise environment when the S/N is greater than −10 dB and for pure tone environment when the S/N is greater than −5 dB. The sensor probe is applied to determine the sound power level of a hard disc drive unit of a personal computer in an office setting. Good agreement is obtained for A-weighted sound power levels determined by the ISO method.     

Image reconstruction of moving acoustic sound sources by temporal reference holography

The feasibility of applying temporal reference holography to detection of moving acoustic radiation sources are examined theoretically and experimentally. Temporal reference holography is proved to be used for the purpose if the width of amplitude spectrum of sound is within a certain range, because the point spread functions of temporal reference hologram coincide with amplitude spectra of sound waves used for recording them.     

Flexible coherent optical probe for vibration measurements

In addition to conventional optical elements, mechanically flexible optical fibers of 17 μm in diameter are successfully used as coherent optical probes for vibration measurements based on optical heterodyne techniques. This means a feasibility of mechanically flexible setup for vibration measurements.     

Measurement of small vibration and deformation by using high order diffraction of a thermoplastic hologram

An experimental study is presented of quasi real-time measurements of small vibration and deformation by using phase difference amplification through high order diffraction of thermoplastic holograms. An optimum recording condition for obtaining high diffraction efficiency of high order diffraction is obtained and the sensitivity becomes three times that of the conventional method.     

Novel wedge-shaped doubly inclined chamber for the flow-through separation of suspended particles

Combined standing and propagating wave modes have previously been successfully used by the authors for simultaneous agglomeration and transportation of small particles suspended in still water. The present study of this method with flowing water, using a 120 x 350 x 13 mm3 agglomerator, confirmed that the proposed method is applicable with suspended SiO2 particles of varying size. The process was found to be most efficient at flow rates below a certain threshold, which varies with particle size. This threshold was found to be 5 ml/s for a particle size of 7.9 microns at an ultrasonic frequency of 2 MHz corresponding to 0.74 mm wavelength. The existence of a maximum particle transport velocity was demonstrated.