A cathode readout gas sampling calorimeter with conductive plastic tubes

We constructed and tested a prototype gas sampling electromagnetic calorimeter of the Pb-proportional tube sandwich type. The calorimeter uses conductive plastic tubes and cathode pad readout with a tower structure which resulted in reasonable energy and spatial resolutions for electrons in the momentum range 0.5–4.0 GeV/c; $\text{σ}{}_{\mathrm{E}}\text{E =}\text{21\%}\text{(E(}\text{GeV}\text{)}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, σ}{}_{\mathrm{x}}\text{= 6}\text{mm}\text{(at 3 GeV}$/c). This paper describes the test and the performance studied under various conditions.     

Performance prediction of a hybrid‐excitation synchronous machine with axially arranged excitation poles and permanent‐magnet poles

This paper presents a method of predicting the steady‐state performance of a new hybrid‐excitation synchronous machine (HESM) theoretically. The field pole of this HESM is axially divided into two parts; one is an excitation part and the other a permanent‐magnet (PM) part. A nonlinear equivalent circuit, which can include the saliency of the rotor and the magnetic saturation due to the iron core, is derived. Based on this equivalent circuit, the steady‐state performance of the HESM is calculated, and the results are confirmed through experiments. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(2): 43–49, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20033     

Theory of rough surface effects on the anisotropic BCS states

We present a Green's function theory of the rough surface effects on the anisotropic BCS states using the formulation developed in the randomly rippled wall model. It is shown that the randomly rippled wall formulation is general enough to treat rough surface effects from the specular limit to the diffusive limit. We propose a statistical wall configuration such that gives the diffusive limit in the normal state. Within the weak coupling theory, we give a formal solution of the quasi-classical Green's function in a slab geometry and in a semi-infinite geometry with arbitrarily rough surfaces. The formal solution already satisfies the boundary condition. In the diffusive limit, the present theory correctly recovers the linearized gap equation obtained by Kjäldman et al. for the p-wave state in a slab geometry.     

Iodine reaction of vinyl acetate/vinyl propionate copolymers. III. Iodine affinities of the radically polymerized copolymers and the copolymers derived from partially saponified polyvinyl acetate

The minimum sequence lengths (n_c) of vinyl acetate (VAc) units necessary to form a colored iodine complex were determined to be 4 and 17 for radically polymerized VAc/vinyl propionate (VPr) and VAc/isopropenyl acetate (IPAc) copolymers, respectively. The iodine affinities (I/VAc) of VAc/VPr copolymers (SP-series) obtained by propionylation of partially saponified polyvinyl acetate (PVAc) were remarkably affected by the saponification conditions. An increase of the water content in acetone/water mixture as saponification solvent brought about a decrease of the iodine affinities of the SP-series. The dependence of the iodine affinity on the saponification of monomer units in the SP-series was compared with that in the radically polymerized VAc/VPr copolymers by taking the sequence probability as the measure of monomer unit distribution. The results strongly supported an occurence of the slide fastener reaction at high degrees of saponification, which was well-known in the saponification of PVAc. Furthermore, it was found that the saponification mode of PVAc at low degrees of saponification was influenced uniquely by the water content in saponification solvents and the saponification temperature.     

Design of new catalysts for ecological high-quality transportation fuels by combinatorial computational chemistry and tight-binding quantum chemical molecular dynamics approaches

Recently, we introduced a concept of combinatorial chemistry to computational chemistry and proposed a new method called “combinatorial computational chemistry”, which enables us to perform a theoretical high-throughput screening of catalysts. In the present paper, we reviewed our recent application of our combinatorial computational chemistry approach to the design of new catalysts for high-quality transportation fuels. By using our combinatorial computational chemistry techniques, we succeeded to predict new catalysts for methanol synthesis and Fischer–Tropsch synthesis. Moreover, we have succeeded in the development of chemical reaction dynamics simulator based on our original tight-binding quantum chemical molecular dynamics method. This program realizes more than 5000 times acceleration compared to the regular first-principles molecular dynamics method. Electronic- and atomic-level information on the catalytic reaction dynamics at reaction temperatures significantly contributes the catalyst design and development. Hence, we also summarized our recent applications of the above quantum chemical molecular dynamics method to the clarification of the methanol synthesis dynamics in this review.     

Sensitive Label-Free Immunoassay by Colorimetric Plasmonic Biosensors Using Silver Nanodome Arrays

The sensitive direct detection of biomolecules is demonstrated by a colorimetric plasmonic biosensor utilizing the surface colors of plasmonic metasurfaces named Ag nanodome arrays. The Ag nanodome arrays consist of polystyrene bead monolayers coated with Ag thin films whose surface colors are optimized by changing the size of the polystyrene beads. The bulk refractive index sensitivity of colorimetric detection evaluated using the hue angle is 590° RIU⁻¹ (RIU: refractive index unit). For selected geometry, the refractive index resolution (5.0 × 10⁻⁵ RIU) obtained by colorimetric detection surpasses that of spectroscopic detection evaluated via the dip wavelength in the reflection spectrum. The numerical simulations predict an enhanced sensing performance when the hue angle of the surface colors of the Ag nanodome arrays changes from 300° to 200°, corresponding to changes in the dip wavelength from 570 to 600 nm in the reflection spectra. Furthermore, the detection sensitivity of the biomolecules is characterized using a direct IgG immunoassay format. The detection limit of the IgG concentration is as low as 134 pM using simple colorimetric detection. The feasibility of sensitive label-free immunoassays using a colorimetric plasmonic biosensor is expected to accelerate the development of highly sensitive and reliable smartphone-based plasmonic biosensors.     

Detection of environmental changes from network structure

We studied the networks of the temperature record in the atmosphere. They are made by the strength of the synchronization, including the delay between temperatures at locations on Earth. We consider these locations as nodes, and we consider a pair of locations as a link if the synchronization between them is stronger than a threshold. The network is scale-free, which is thought to contribute to the stability of the climate. This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January 25–27, 2007     

A new learning method using prior information of neural networks

In this paper, we present a new learning method using prior information for three-layer neural networks. Usually when neural networks are used for identification of systems, all of their weights are trained independently, without considering interrelated weights values. Thus, the training results are usually not good. The reason for this in that each parameter has its influence on others during learning. To overcome this problem, we first give an exact mathematical equation that describes the relation between weight values given a set of data conveying prior information. The we present a new learning method that trains part of the weights and calculates the others using these exact mathematical equations. This method often a priori keeps the given mathematical structure exactly the same during learning; in other words, training is done so that the network follows a predetermined trajectory. Numerical computer simulation results are provided to support this approach. This work was presented, in part, at the Fourth International Symposium on Artificial Life and Robotics, Oita, Japan, January 19–22, 1999.     

Design of recursive digital filters for the selection or rejection of a particular velocity in seismic signals

In this paper a new type of velocity-selecting/rejecting filter which passes or stops a particular event in a seismic signal is proposed. The velocity-selecting filter is based on a time-space band-pass filter with sharp passband for a particular direction, and similarly, the velocity-rejecting filter is based on a time-space band-stop filter. A technique for designing such filters, in terms of an infinite-impulse-response (IIR) filter, is presented, in which a rotated version of separable filter is used. Finally, numerical examples are included to illustrate the design theory.