Seri O.,Muroran Institute of Technology
Electrochemistry Communications | Year: 2017
A new technique was introduced to assist the Tafel extrapolation method (TEM). The hydrogen evolution reaction (her) on nickel electrode in H2SO4 solution was investigated in comparison with the TEM and proposed technique. The exchange current density (j0) for her was assessed from points of simple and more accurate handling. The proposed technique has advantages: (1) proper reading of the Tafel slope region and (2) easy removing of undesirable physical factors such as oxide film and solution resistances. © 2017 Elsevier B.V.
Muroran Institute of Technology and Nitta Corporation | Date: 2012-07-25
The present invention provides an aromatic polyester which is substantially free from the occurrence of coloration and retains significantly high transparency even after being thermally processed at high temperature and which has high flowability. The aromatic polyester contains a polyhydric phenol residue and a residue of any one of aromatic polycarboxylic acid, halide thereof, and anhydride thereof, and terminals of the aromatic polyester have a structure represented by the formula -C(O)-R. The aromatic polyester has an end-capping rate of 90% or higher and a weight average molecular weight (Mw) ranging from 3,000 to 1,000,000.
Nitta Corporation and Muroran Institute of Technology | Date: 2010-09-09
The present invention provides an aromatic polyester which is substantially free from the occurrence of coloration and retains significantly high transparency even after being thermally processed at high temperature and which has high flowability. The aromatic polyester contains a polyhydric phenol residue and a residue of any one of aromatic polycarboxylic acid, halide thereof, and anhydride thereof, and terminals of the aromatic polyester have a structure represented by the formula C(O)R. The aromatic polyester has an end-capping rate of 90% or higher and a weight average molecular weight (Mw) ranging from 3,000 to 1,000,000.
Kadokawa J.-I.,Kagoshima University |
Kadokawa J.-I.,Muroran Institute of Technology
RSC Advances | Year: 2015
Recent developments in the fabrication of nano- and microstructured chitin materials are reviewed, specifically focusing on approaches through gelation with suitable dispersion media. Although chitin is one of the most abundant natural polysaccharides, it is under-used as a result of its poor solubility and difficulties in processing. The dissolution of chitin in different solvent systems, including ionic liquids, has been investigated for the production of various materials. For example, the ionic liquid 1-allyl-3-methylimidazolium bromide dissolved chitin at concentrations up to 5% w/w and formed ion gels at higher concentrations of chitin. A highly concentrated solution of CaBr2·2H2O/methanol also induced the gelation of chitin. As one of the most efficient methods of production of nanomaterials from chitin, self-assembled nanofibers have been fabricated by regeneration from solutions or gels of chitin with the appropriate solvents and dispersion media using a bottom-up approach. For example, a chitin ion gel with 1-allyl-3-methylimidazolium bromide was regenerated using methanol to produce a chitin nanofiber dispersion, which was then used to construct a film with a highly entangled nanofiber morphology by filtration. Physical and chemical approaches have been investigated for the fabrication of composite materials of self-assembled chitin nanofibers with other polymeric components. Poly(vinyl alcohol) and carboxymethyl cellulose were made compatible with chitin nanofibers by co-regeneration and electrostatic interaction procedures, respectively. Surface-initiated graft polymerization of some monomers from chitin nanofiber films with the appropriate initiating groups have been conducted using the latter approach to obtain composite films covalently linked to graft chains on the nanofibers. Regeneration from gels with CaBr2·2H2O/methanol resulted in the efficient production of microporous materials. © The Royal Society of Chemistry 2015.
Eguchi M.,Chitose Institute of Science and Technology |
Tsuji Y.,Muroran Institute of Technology
Journal of Lightwave Technology | Year: 2013
In photonic bandgap (PBG) fibers, light is confined by a photonic bandgap caused by a periodic structure of air holes in the cladding regions. The doubly degenerate fundamental mode in ideal PBG fiber structures becomes slightly nondegenerate in actually produced fibers, and this causes polarization instability and polarization mode dispersion. Here, to avoid these problems, we propose a novel absolutely single-polarization PBG fiber structure with an elliptical-hole lattice core. A PBG fiber with a single-polarization bandwidth of 420 nm is numerically demonstrated. Furthermore, based on the proposed fiber structure, we report another single-polarization PBG fiber that has two absolutely single-polarization bands being orthogonal to each other. © 2012 IEEE.
Nakano H.,Muroran Institute of Technology
Chemistry Letters | Year: 2011
The ability of photoinduced surface-relief-grating (SRG) formation of 4-[bis(4-methylphenyl)amino]azobenzene (BMAB) was found to be drastically enhanced by mixing with 4,4′,4″- tris[3-methylphenyl(phenyl)amino] triphenylamine (m-MTDATA) due to the increase in glass-transition temperature (T g). The resulting SRG inscribed on the mixed amorphous film remained even after annealing at 55°C, which was considerably higher than the T g of BMAB. These results suggest that the m- MTDATA molecules in the mixed film were transported together with BMAB molecules upon irradiation with the writing beams. © 2011 The Chemical Society of Japan.
Koga T.,Muroran Institute of Technology
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2012
The pth-order conditional electron density C (p) N(r 1,⋯, r p 1|r p) of an N-electron system is shown to have a peculiar property that when the radius r p = |r p| of the pth electron approaches , it reduces to the (p1)th-order reduced density Γ (p 1) N 1(r 1,⋯, r p 1) divided by p of the (N1)-electron system arising from the removal of an electron from the original system, where both systems are considered to be in their ground states. © 2012 IOP Publishing Ltd.
Koga T.,Muroran Institute of Technology
Journal of Physics B: Atomic, Molecular and Optical Physics | Year: 2013
Based on subshell and shell analysis of the electron-pair radial density D(2)(r1, r2) of atoms, we report that D (2)(r1, r2) is well expressed by a set of shell densities dn(r) in the Hartree-Fock theory, where n denotes the principal quantum number. Numerical tests on the 53 atoms, He through Xe, show that the quantum similarity index, bounded by 0 (complete dissimilarity) and 1 (complete similarity), is never smaller than 0.9995 between the original and approximate electron-pair densities. The relation implies a construction of a two-electron property from single-electron properties. The result is applied to the derivation of an improved upper bound to the radial coalescence density in terms of the single-electron radial density D(r). Numerical tests for the 53 atoms demonstrate the usefulness of the new bound. © 2013 IOP Publishing Ltd.
Kaneiwa K.,Iwate University |
Kudo Y.,Muroran Institute of Technology
International Journal of Approximate Reasoning | Year: 2011
Sequential pattern mining is a crucial but challenging task in many applications, e.g., analyzing the behaviors of data in transactions and discovering frequent patterns in time series data. This task becomes difficult when valuable patterns are locally or implicitly involved in noisy data. In this paper, we propose a method for mining such local patterns from sequences. Using rough set theory, we describe an algorithm for generating decision rules that take into account local patterns for arriving at a particular decision. To apply sequential data to rough set theory, the size of local patterns is specified, allowing a set of sequences to be transformed into a sequential information system. We use the discernibility of decision classes to establish evaluation criteria for the decision rules in the sequential information system. © 2011 Elsevier Inc. All rights reserved.
Nakano H.,Muroran Institute of Technology |
Suzuki M.,Muroran Institute of Technology
Journal of Materials Chemistry | Year: 2012
Relatively long-range mass flow at the surface level of amorphous films of azobenzene-based photochromic molecular materials was observed upon angled irradiation using a p-polarized laser beam. According to the same principle, the movement of the fragments of these molecular glasses could be induced by angled irradiation from their bottom. © 2012 The Royal Society of Chemistry.