Micro 3D measurement method using SEM

Three diamensional (3D) measurement method by Scanning Electron Microscope (SEM) has already been proposed by using the principle of shadow moiré. In the method, the image of original grid in shadow moiré image must be clearly removed in fringe analysis process in order to perform high resolution analysis. A new method based on the principle of projection moiré is proposed to solve the trouble concerning the grid. In this paper, the mechanism of producing some shadows of grid on the surface of the object by back scattering electron beam in the new method is discussed. Fringe image as shadow of grid is analyzed by Wavelet transform. The precise 3D measurement is realized by using the phenomenon of shadows of grid. Furthermore, a 3D micro structure on the head of a hard disk is measured. From the comparison of results obtained by Atomic Force Microscope (AFM), it is confirmed that the proposed method has high-resolution power(about 20nm).     

The temperature dependence of luminescence from a long-lasting phosphor exposed to ionizing radiation

The temperature dependence of luminescence from a long-lasting phosphor (LLP), SrAl₂O₄ : Eu²⁺,Dy³⁺, exposed to ionizing radiation has been measured to understand the LLP luminescence mechanism. Evaluation of the decay constants of the LLP exposed to -, β- or γ-rays at temperatures from 200 to 390 K showed that the decay constant is divided into four components ranging from 10⁻⁴ to 10⁻¹ s⁻¹ with activation energies of 0.02–0.35 eV.

Total luminous intensity from the LLP with changing irradiation temperature has its maximum value around the room temperature. Irradiation at elevated temperature (390 K) has the total luminescence pattern with monotonous decrease as temperature rises. As a result of evaluating the temperature dependence of luminescence, the luminescence mechanism is considered as follows:

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Estimation method for the light extraction efficiency of light-emitting elements with a rigorous grating diffraction theory

The light extraction efficiency of a light-emitting element with microstructured surface is analyzed with a rigorous grating diffraction theory. The grating theory reveals an improvement of extraction efficiency due to diffraction of light by the surface microstructure. The simulation results show that the improvement of extraction efficiency is due mainly to the reflected diffraction rather than to the transmitted diffraction. A part of total-internal-reflection light is diffracted into directions at less than the critical angle. Extraction efficiency is improved by multiple reflection and diffraction of light in a high-refractive-index layer. We propose a simple design method for an efficient surface microstructure from the viewpoint of reflected diffraction.     

Fabrication of micro-patterned TiO2 thin films incorporating Ag nanoparticles

A photosensitive TiO₂ thin film embedded with Ag nanoparticles has been prepared from a Ti(OBu)₄–acetylacetone solution, containing dispersed Ag nanoparticles, by the sol–gel method. UV–visible absorption spectra showed that the thin film obtained has two absorption bands, characteristic of the acetylacetone chelate rings and plasmon resonance from Ag nanoparticles. After the irradiation of UV light, the absorption band from the chelate rings almost disappeared, ascribed to structural changes associated with dissociation of the chelate rings. The thin film after the UV irradiation exhibited a broad absorption band in the IR spectrum, indicating that a Ti–O–Ti network was formed in the thin film. HRTEM and EDX spectra revealed that Ag nanoparticles were present and dispersed in the TiO₂ thin film. Micro-patterns of 50 μm dots have been fabricated by UV irradiation through a corresponding photomask, followed by leaching.     

Ultrashort X-ray pulse generation using subpicosecond electron linac

As a promising tool for ultrafast material analyses, we propose to utilize the X-ray pulse which may be generated in a quite simple manner using subpicosecond electron linacs. The properties of the X-ray were numerically studied with the EGS4 code. Verification of the X-ray generation was also conducted at the Nuclear Engineering Research Laboratory (NERL) linac and clear diffraction patterns of characteristic X-ray were obtained for typical single crystals.     

A comprehensive economic analysis of biomass gasification systems

This paper presents a comprehensive economic analysis of biomass gasification systems. There has recently been interest in promoting biomass energy systems in Japan's domestic sector. However, there are problems in achieving this project. The costs of plant construction are very high compared with conventional plants. Accordingly, the unit costs of electricity will be increased to levels comparable with those of other environmental energy systems. Copyright © 2004 Wiley Periodicals, Inc. In this paper, biomass energy systems using woody biomass are proposed from the viewpoint of successful environmental business. Biomass integrated gasification combined cycle (BIGCC) plants operated by independent power producers and biomass gasification cogeneration (BGCGS) plants in sawmills or asphalt‐concrete production factories have the potential for implementation in the near future. Our analysis concludes that the systems proposed in this paper provide the following outcomes with subsidies: (1) the generating cost of BIGCC ranges from 15.1 to 36.6 yen/kWh, (2) the generating cost of BGCGS ranges from 2.6 to 32.2 yen/kWh, and (3) the cost reduction of BGCGS products in asphalt factories amounts to about 60 million yen per year. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 52–63, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20089     

Test run of combined propulsion,levitation and guidance system at Miyazaki test track

In commercializing the superconducting Maglev system it is important to reduce the cost, especially that of ground coils constructed along the whole length of the guideway. For this purpose we have examined the combined propulsion, levitation and guidance system (PLG system) which can generate levitation, guidance and propulsion forces by the same coil. This paper describes the test run of the PLG system, whose ground coils (PLG coil) are constructed in one part of the Miyazaki test track. In designing the PLG coil, we make clear the magnitudes of the force acting both under normal and unusual conditions because the electromagnetic force, which levitates, guides, and propels the vehicle, directly acts on the magnet winding of the PLG coil. In the experiment, we examine both the performance of the vehicle and the force of a PLG coil. The measurement of the force at the PLG coil gives not only propulsion force and levitation force directly, but also guidance stiffness by sifting the measured coil. Good correlation recognized between the calculation and the experiment in the propulsion force, levitation force, and guidance stiffness proves that the required characteristics can be expected from the PLG system even under combination of propulsion, levitation and guidance.     

Influence of Thermo-mechanical Control Process for Duplex Stainless Steel on Low-Temperature Toughness

Metallurgical and Materials Transactions A - The microstructure dependence of the low-temperature toughness of a 2205 duplex stainless steel produced by a thermo-mechanical control process was...