An Optical Fiber Video System

A general discussion is made of optical fiber video systems from the viewpoint of system design concepts, transmission schemes, etc. Among possible analog CATV systems, the Higashi-Ikoma Project is reviewed as an optical fiber video system application. The essential components and basic technologies required for optical fiber video systems are reviewed. System performance is reviewed by considering some of the typical field trial conditions.     

A 2D–3D integrated tabletop environment for multi‐user collaboration

This paper proposes a novel tabletop display system for natural communication and flexible information sharing. The proposed system is specifically designed to integrate two‐dimensional (2D) and three‐dimensional (3D) user interfaces by using a multi‐user stereoscopic display, IllusionHole. The proposed system takes awareness into consideration and provides both 2D and 3D information and user interfaces. On the display, a number of standard Windows desktop environments are provided as personal workspaces, as well as a shared workspace with a dedicated graphical user interface. In the personal workspaces, users can simultaneously access existing applications and data, and exchange information between personal and shared workspaces. In this way, the proposed system can seamlessly integrate personal, shared, 2D, and 3D workspaces with conventional user interfaces and effectively support communication and information sharing. To demonstrate the capabilities of the proposed display system, a modeling application was implemented. A preliminary experiment confirmed the effectiveness of this system. Copyright © 2006 John Wiley & Sons, Ltd.     

Load dependence of sticking-domain distribution in two-dimensional atomic scale friction of NaF(100) surface

Remarkable transitions were found in atomic-scale friction-images of the NaF(100) surface and the corresponding sticking-domain distribution by detailed investigation of the load dependence using the two-dimensional frictional force microscope. The tip-position map reveals a new type of sticking-domain distribution pattern, which is different from the simple lattice periodicity.     

New design and development of size‐selected gas cluster SIMS

A new cluster time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) was developed, using a size‐selected gas cluster ion as a projectile. Because a large gas cluster ion can generate numerous low‐energy constituent atoms during a collision with the surface, multiple and ultralow‐energy sputterings are induced. Dividing the acceleration energy of a gas cluster ion by the number of constituent atoms provides the mean kinetic energy of the constituent atoms. Hence, sputtering can be controlled to minimize decomposition of the sample molecules by precisely adjusting the number of constituent atoms (the cluster size) and/or the acceleration energy of the gas cluster ions. The cluster size was selected by the time‐of‐flight method using two ion deflectors attached along the ion‐beam line. A high resolution of 11.7 was achieved for the cluster size/size width (m/Δm) of the Ar‐cluster ions. The SIM spectra of poly(methyl methacrylate) (PMMA) were measured using the size‐selected gas‐cluster SIMS machine. The large fragment ions emitted from PMMA are enhanced as the cluster size increases. This result suggests that a large cluster ion projectile in which each constituent atom within the cluster has decreased kinetic energy inhibits the decomposition of the polymer structure. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(3): 52–58, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21159     

Application of generalized grating imaging to pattern projection in three-dimensional profilometry

The theory of generalized grating imaging for a one-dimensional grating is applied to a pattern projection system in pattern projection profilometry. Contrast of the projected grating image is calculated under various conditions. The results help to determine the conditions suitable for obtaining high contrast grating images in a large space. Although the gratings required for the profilometry are hexagonal, the theory for two-dimensional gratings is prohibitively complex. Therefore, the projection system was designed using the one-dimensional theory. The projection system using two-dimensional hexagonal gratings was constructed and experiments were done with it. The result agrees approximately with the theoretical calculations for one-dimensional gratings. This suggests that the one-dimensional theory may be used for estimating the approximated behavior for hexagonal gratings for use in pattern projection profilometry. Some discussions are given for the application of the projection system for profiling the mannequin or human body.     

Structure characterization of Pd/Co/Pd tri-layer films epitaxially grown on MgO single-crystal substrates

Pd/Co/Pd tri-layer films were prepared on MgO substrates of (001), (111), and (011) orientations at room temperature by ultra high vacuum rf magnetron sputtering. The detailed film structures around the Co/Pd and the Pd/Co interfaces are investigated by reflection high energy electron diffraction. Pd layers of (001)_fcc, (111)_fcc, and (011)_fcc orientations epitaxially grow on the respective MgO substrates. Strained fcc-Co(001) single-crystal layers are formed on the Pd(001)_fcc layers by accommodating the fairly large lattice mismatch between the Co and the Pd layers. On the Co layers,, Pd polycrystalline layers are formed. When Co films are formed on the Pd(111)_fcc and the Pd(011)_fcc layers, atomic mixing is observed around the Co/Pd interfaces and fcc-CoPd alloy phases are coexisting with Co crystals. The Co crystals formed on the Pd(111)_fcc layers consist of hcp(0001) + fcc(111) and Pd(111)_fcc epitaxial layers are formed on the Co layers. Co crystals epitaxially grow on the Pd(011)_fcc layers with two variants, hcp(11?00) and fcc(111). On the Co layers, Pd(011)_fcc epitaxial layers are formed.     

Self-assembled fabrication of a polycrystalline boron-doped diamond surface supporting Pt (or Pd)/Au-shell/core nanoparticles on the (111) facets and Au nanoparticles on the (100) facets

Modified boron-doped diamond (BDD) surfaces supporting different, carefully selected types of metal nanoparticles on different types of crystal facets were fabricated via a self-assembly method. A hydrogen plasma-treated BDD surface was treated with UV/ozone for 10 s followed by immersion in a Au nanoparticle (AuNP) solution to fabricate a BDD surface selectively and densely supporting AuNPs on the (111) facet (AuNP₁₁₁-BDD). The AuNP₁₁₁-BDD sample was then immersed in H₂PtCl₆/ascorbic acid or H₂PdCl₄/sodium citrate to cover the AuNP surface with Pt or Pd (Pt/AuNP₁₁₁-BDD or Pd/AuNP₁₁₁-BDD). These samples were treated with UV/ozone for 40 s followed by re-immersion in the AuNP solution to immobilize AuNPs on the (100) facets (Pt/AuNP₁₁₁-AuNP₁₀₀-BDD or Pd/AuNP₁₁₁-AuNP₁₀₀-BDD). The metal nanoparticles supported on the BDD surface were confirmed by cyclic voltammetry to be electrochemically active. The crystal-facet-selective support of the metal nanoparticles was also confirmed by two-dimensional elemental mapping via field emission Auger electron spectroscopy. The macro procedures used for the crystal-facet-selective immobilization of the AuNPs was reproducible, and this technique should be applicable to the creation of a new class of advanced materials in such fields as optics, electronics, sensing, and (electro)catalysis.     

The effects of break location on PWR small break LOCA: Experimental study at the ROSA-IV LSTF

This paper discusses the effect of break location on the break flow rate and break flow quality transitions during a small-break loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). Results from five experiments conducted at the ROSA-IV Large Scale Test Facility (LSTF) are compared for this purpose. These experiments simulated a 2-inch break at the lower plenum, upper head, pressurizer top, cold leg, and hot leg, respectively. The controlling phenomena for the break flow quality transitions in cold-leg and hot-leg break experiments are described.     

Investigation of pre- and post-dryout heat transfer of steam-water two-phase flow in a rod bundle

Pre- and post-dryout heat transfer experiments were performed for steam-water two-phase flow in a 5 × 5 rod bundle under conditions of total mass fluxes from 80 to 320 kg/m²s, inlet qualities from 0.1 to 0.8, heat fluxes from 3 to 26 W/cm² and a pressure of 3 MPa. Heater rod surface temperatures or heat transfer coefficients predicted by several correlations were compared with experimental data with emphasis on the applicability of the correlations to the present experimental conditions which were pertinent to thermal-hydraulic conditions during a LOCA in a nuclear reactor. The Chen and Biorge et al. correlations underestimated heat transfer coefficients in the pre-dryout region. The Varone-Rohsenow prediction which accounted for the thermal nonequilibrium effect, calculated heater rod surface temperatures relatively well in the post-dryout region over the whole region of the present experimental conditions. The Dittus-Boelter and Groeneveld correlations predicted heater rod surface temperatures relatively well in the post-dryout region under high total mass flux conditions, but underestimated considerably under low total mass flux conditions.