Development of the Micro Pixel Chamber with resistive electrodes

We developed a novel design of a Micro Pixel Chamber ($\mu$-PIC) with resistive electrodes for a charged-particle-tracking detector in high-rate applications. Diamond-Like Carbon (DLC) thin film is used for the cathodes. The resistivity can be controlled flexibly ($\mathrm{10^{5-7}k\Omega/sq.}$) at high uniformity. The fabrication-process was greatly improved and the resistive $\mu$-PIC could be operated at 10$\times$10 $\mathrm{cm^2}$. Resistors for the HV bias and capacitors for the AC coupling were completely removed by applying PCB and carbon-sputtering techniques, and the resistive $\mu$-PIC became a very compact detector. The performances of our new resistive $\mu$-PIC were measured in various ways. Consequently, it was possible to attain high gas gains ($\mathrm{> 10^{4}}$), high detection efficiency, and position resolution exceeding 100 $\mu$m. The spark current was suppressed, and the new resistive $\mu$-PIC was operated stably under fast-neutrons irradiation. These features offer solutions for a charged-particle-tracking detector in future high-rate applications.Comment: 37pages, 40figures, To be submitted to Nucl. Instrum. Methods Phys. Res.

Adsorption of tetrakis(p-sulfonatophenyl)porphyrin on kaolinite

Copyright (c) 2009 Springer The original publication is available at www.springerlink.comThe surface modification of kaolinite to introduce the adsorption sites for anionic species was reported. The introduction of an anion exchange site was as follows; intercalation of 2-aminoethanol into kaolinite by using dimethyl sulfoxide-kaolinite intercalation compound as a precursor and subsequent hydrochlorination of 2-aminoethanol-kaolinite in 1,4-dioxane. The hydrochlorination of 2-aminoethanol-kaolinite was confirmed by the increase in the basal spacing (0.2 nm, corresponding to the diameter of chlorine) and the appearance of the infrared absorption bands due to ammonium groups. The modified kaolinite adsorbed an anionic dye, tetrakis(p-sulfonatophenyl)porphyrin, from a N,N-dimethylformamide solution. Initial slope of the adsorption isotherm of tetrakis(p-sulfonatophenyl)porphyrin on the hydrochlorinated 2-aminoethanol-kaolinite was steep, showing strong adsorbate-adsorbent interactions. The gallery height after the adsorption of tetrakis(p-sulfonatophenyl)porphyrin was close to the thickness of the porphyrin ring, suggesting that tetrakis(p-sulfonatophenyl)porphyrin was intercalated as a monomolecular layer and that chlorine simultaneously deintercalated.ArticleJOURNAL OF POROUS MATERIALS. 16(6):623-629 (2009)journal articl

Concentration of 2-phenylphenol by organoclays from aqueous sucrose solution

The adsorption of 2-phenylphenol, which is an antifungal agent, onto organically modified clay from aqueous sucrose solution was investigated. 2-Phenylphenol was effectively adsorbed on neostigmine-modified smectites and octadecyltrimethylammoniurh modified smectites even in the presence of sucrose in the starting aqueous solution. Two smectites (a natural montmorillonite, Kunipia F, and a synthetic saponite, Sumecton SA) were used to find clay minerals with lower layer charge density gave larger adsorption capacity for 2-phenylphenol. The result showed the potential application of the organically modified clays to remove 2-phenylphenol from orange extracts. (C) 2014 Published by Elsevier B.V.ArticleAPPLIED CLAY SCIENCE. 109: 64-67 (2015)journal articl

Polar Antiferromagnets Produced with Orbital-Order

Polar magnetic states are realized in pseudocubic manganite thin films fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion remains an active variable. Several types of orbital-orders were found to develop large optical second harmonic generation, signaling broken-inversion-symmetry distinct from their bulk forms and films on (100) substrates. The observed symmetry-lifting and first-principles calculation both indicate that the modified JT q2 mode drives Mn-site off-centering upon orbital order, leading to the possible cooperation of "Mn-site polarization" and magnetism.Comment: 5 pages, 4 figure

Mult-wavelength, simultaneous observations of auroras at South Pole and McMurdo stations

The Tenth Symposium on Polar Science/Special session: [S] Future plan of Antarctic research: Towards phase X of the Japanese Antarctic Research Project (2022-2028) and beyond, Tue. 3 Dec. / Entrance Hall (1st floor) at National Institute of Polar Research (NIPR

内側楔状開大式高位脛骨骨切り術後の3次元T1ρ-mappingを用いた軟骨定量評価

Purpose: To evaluate the recently developed three-dimensional (3D) T1ρ-mapping technique for the quantitative evaluation of cartilage changes after open-wedge high tibial osteotomy (OWHTO). Method: Eleven patients with medial knee osteoarthritis and spontaneous osteonecrosis of the medial femoral condyle underwent T1ρ magnetic resonance imaging. The full-thickness cartilage of the medial femoral condyle (MFC), lateral femoral condyle, medial tibial condyle, and lateral tibial condyle, and the trochlea and patella were set as regions of interest; mean T1ρ values were calculated using two-dimensional (2D) and 3D analyses. The state of cartilage injury was evaluated using the International Cartilage Repair Society grading system (ICRS grade). T1ρ values before OWHTO and after hardware removal were compared using the Wilcoxon signed-rank test. The correlation between T1ρ values and the ICRS grade was explored using the Spearman rank correlation coefficient. Results: Cartilage repair at the MFC was observed in a high proportion of patients (82%), but 2D analysis did not reveal a significant difference after surgery at any site. In contrast, 3D analysis revealed a significant decrease in T1ρ values after surgery at the MFC (before surgery: 44.1 ms; after surgery: 38.9 ms; p = 0.016), but no significant difference at any other site. In the MFC, there was a positive correlation between 3D T1ρ values and arthroscopic findings before and after surgery (rs = 0.62, p < 0.01), which was absent from the 2D T1ρ values. Conclusions: 3D T1ρ-mapping may be an effective tool for detecting changes in cartilage quality after OWHTO.博士（医学）・甲第848号・令和4年9月28日© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/)