Kota Y.,Fukushima College |
Yoshimori Y.,Osaka University |
Imamura H.,Japan National Institute of Advanced Industrial Science and Technology |
Kimura T.,Osaka University
Applied Physics Letters | Year: 2017
The effect of hydrostatic pressure on structure and magnetism was investigated by a combined theoretical and experimental study for Cr2O3 showing the linear magnetoelectric effect below the Néel temperature TN ≈ 307 K. Based on first-principles calculations and Monte-Carlo simulations, we predicted that TN linearly increases with increasing applied pressure P with the slope of (1/TN)(dTN/dP) = +1.9 × 10−2 GPa−1. This theoretical prediction was qualitatively verified by our experimental observation about the pressure dependence of TN, which was detected by measurements of dielectric constant through the magnetoelectric coupling [(1/TN)(dTN/dP) = +1.6 × 10−2 GPa−1]. These results provide an effective way to enhance magnetoelectric operating temperature in the rare room-temperature magnetoelectric, Cr2O3. © 2017 Author(s).
Nishiura K.,Fukushima College |
Ouchi S.,Shimonoseki City University |
Usui K.,Japan National Institute of Advanced Industrial Science and Technology
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017
In this paper, we analyze how the accurate use of mathematical graphics in teaching materials contributes to an understanding of mathematics. We describe an experimental study used to verify the educational effect of teaching materials including mathematical graphics, and outline a method to analyze the experimental results. The mathematical software KeTCindy was used to make the teaching materials including mathematical artworks, and to process data collected using a cognitive detection clicker system which we created. The results suggest that careful use of mathematical artworks produced with a system such as KeTCindy can help improve student understanding of mathematical problems. © Springer International Publishing AG 2017.
Wakamatsu T.,Fukushima College |
Fujimura R.,Utsunomiya University |
Kajikawa K.,Tokyo Institute of Technology
Applied Optics | Year: 2017
On silver thin film, an organic semiconductor rubrene layer consisting of a planar waveguide exhibits spectrally narrowing photoluminescence (PL) spectra with an increasing emission angle, which are compared with those of rubrene thin films on glass. The PL spectra of rubrene on Ag have a polarization characteristic. In the side direction of the multilayer structure, spectrally very sharp PL was observed. The PL characteristics are discussed from the viewpoint of waveguided modes allowed only for a phase-matching condition. The narrowed PL spectra are attributable to generation of a leaked waveguided mode in the rubrene layer, which is supported by the underlying Ag thin film. © 2017 Optical Society of America.
Moriya M.,Nihon University |
Sakatani K.,Fukushima College
Advances in Experimental Medicine and Biology | Year: 2017
Recent near-infrared spectroscopy (NIRS) studies demonstrated that physical exercise enhances working memory (WM) performance and prefrontal cortex (PFC) activity during WM tasks in normal adults. Interestingly, the effects of rehabilitation (i.e. physiotherapy) on post-stroke patients could be enhanced by motor imagery (MI), an active process during which the specified action is reproduced within WM without any actual physical movement. However, it is not known whether MI can enhance cognitive function and associated brain activity. To clarify these issues, we evaluated the effect of MI on WM performance and PFC activity during WM tasks in normal adults, employing NIRS. We studied 10 healthy adults. The present study was a crossover comparison test; the MI training and control condition (rest) were applied to the subjects at random. The Time Up and Go method was used for MI training: the subject sat on a chair and conducted MI for 3 min, three times. Neuronal activity (oxyhemoglobin concentration) in the bilateral PFC was measured using 2-CH NIRS during WM tasks. We found that MI improved the behavioral performance of WM compared with the control (p < 0.01). NIRS revealed that MI enhanced PFC activity induced by the WM task compared with the control task (p < 0.01). These results suggest that MI can improve cognitive function and increase associated PFC activity in normal adults. © Springer International Publishing AG 2017.
Wang Z.-L.,Tottori University |
Onda T.,Tottori University |
Chen Z.-C.,Tottori University |
Akao T.,Fukushima College
Scripta Materialia | Year: 2017
A rapid solidification and spark plasma sintering technique was applied to fabricate Bi-Sb-Te bulk thermoelectric materials. Although the grain boundaries in sintered samples were primarily composed of large-angle boundaries, a large fraction of small-angle boundaries was found at a high sintering temperature. As the sintering temperature increased, the Seebeck coefficient was almost unchanged while the electrical resistivity gradually decreased. The thermal conductivity gently increased till 420 °C, and then abruptly increased. As a result, the largest ZT value of 1.1 was achieved for the sample sintered at 400 °C, which is increased by 44.7% compared with that prepared from mechanically alloyed powders. © 2017 Acta Materialia Inc.
Takigawa T.,Okayama University of Science |
Saijo Y.,Asahikawa University |
Morimoto K.,Osaka University |
Nakayama K.,Osaka University |
And 5 more authors.
Science of the Total Environment | Year: 2012
To determine whether indoor chemicals act as possible environmental risk factors responsible for sick building syndrome (SBS)-related symptoms in new houses (< 6. years old) in Japan, we studied 871 people living in 260 single-family houses in 2004 and 2005. We measured the indoor concentrations of aldehydes and volatile organic compounds and longitudinal changes in the living rooms over two consecutive years. Participants answered standardized questionnaires on SBS symptoms and lifestyle habits. Approximately 14% and 12% of subjects were identified as having SBS in the first and second year, respectively. According to analysis adjusted for sex, age, smoking, and allergic diseases, increases in aldehydes and aliphatic hydrocarbons contributed to the occurrence of SBS. Elevated levels of indoor aldehydes and aliphatic hydrocarbons increased the possible risk of SBS in residents living in new houses, indicating that source controls against indoor chemicals are needed to counter SBS. © 2011 Elsevier B.V.
Hyodo K.,Tohoku University |
Sakuma A.,Tohoku University |
Kota Y.,Fukushima College
Physical Review B - Condensed Matter and Materials Physics | Year: 2016
We develop a first-principles procedure for the individual evaluation of the intrinsic, side-jump, and skew-scattering contributions to the anomalous Hall conductivity σxy. This method is based on the different microscopic conductive processes of each origin of σxy in the Kubo-Bastin formula. We also present an approach for implementing this scheme in the tight-binding linear muffin-tin orbital (TB-LMTO) method with the coherent potential approximation (CPA). The validity of this calculation method is demonstrated for disordered FePt and FePd alloys. We find that the estimated value of each origin of σxy exhibits reasonable dependencies on the electron scattering in these disordered alloys. © 2016 American Physical Society.
Yokota O.,Fukushima College
Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C | Year: 2012
In this study, the replica of the metal processing surface was produced using the transparent silicone. The new measuring method which examined the transmission image was proposed with a scattering of the spot light in the replica. The result was summarized in the following. It was able to be classified to four patterns of the transmission image from the replica reflection plane, that is to say, point pattern, circular pattern, elliptic pattern, diffraction pattern. It is possible that these patterns estimate the shape of the reflection plane, namely shape and processing method of the machined surface. The surface roughness by the diffraction was equal to the maximum height roughness by the tracer. In circular pattern and elliptic pattern, the empirical formula which showed the relationship between maximum height roughness and radius of gyration was obtained. In the point pattern, it was not possible to show surface roughness in the measuring range of this experiment. © 2012 The Japan Society of Mechanical Engineers.
Yamauchi N.,Fukushima College |
Kurumada K.,Fukushima College
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2016
A facile method for surface hydrophobization of magnetite (Fe3O4) nanoparticles with polyhexylsilsesquioxane was proposed. The surface-hydrophobizing coating formed of polyhexylsilsesquioxane on the surface of the magnetite nanoparticles was spontaneously generated from hexylated silanol moiety dissolved in diethylamine. Due to the Lewis basicity, diethylamine worked as the catalyst for the polycondensation of the hexylated silanol. At the same time, the relatively low polarity of diethylamine was found favorable for maintaining the dispersibility of the polyhexylsilsesquioxane-coated magnetite nanoparticles. Moreover, the presence of the surface-hydrophobizing coating was effective for suppressing the transition of the magnetite phase to hematite (α-Fe2O3) even under highly oxidative condition since the polyhexylsilsesquioxane coating blocked oxygen molecules from the access to the surface of the magnetite nanoparticles as evidenced by the absence of micropores in the polyhexylsilsesquioxane coating layer. © 2016 Elsevier B.V.
Imai E.,Nagoya University |
Yamamoto R.,Osaka University |
Suzuki H.,Saitama University |
Watanabe T.,Fukushima College
Clinical and Experimental Nephrology | Year: 2010
Background: Use of erythropoiesis-stimulating agents (ESA) has been reported to increase the incidence of cardiovascular diseases at target Hb levels by more than 12.0 g/dl. The recent TREAT study found an increased incidence of stroke and cancer when maintaining the Hb level at 12.5 g/dl in diabetic patients. Methods: Surveillance of Epoetin-Adverse Events of Stroke and Cancer (SEASCAN) was a cross-sectional study conducted under urgent conditions by the Committee on CKD Initiatives of the Japanese Society of Nephrology. Patients who were at least 18 years old and had CKD stage 4 and 5, namely, eGFR <30 ml/min/1.73 m2, and who had visited the outpatient department of the participating facilities between December 2009 and January 2010 with at least 6 months of prior medical treatment in the participating facilities were eligible to participate in the study. Results: Of 7,415 patients with CKD stage 4 and 5, 3,653 (49.3%), 879 (11.9%) and 2,883 (38.9%) patients received no epoetin, epoetin for less than 6 months and epoetin for at least 6 months, respectively. In patients who did not use epoetin, use of epoetin for less than 6 months and use of epoetin for at least 6 months, the numbers of patients with stroke were 38 (1.0%), 8 (0.9%) and 27 (0.9%), respectively, and those with newly diagnosed or exacerbated malignancy were 88 (2.4%), 30 (3.4%) and 71 (2.5%), respectively, demonstrating insignificant associations between outcome and duration of treatment with epoetin (P for trend = 0.666 in stroke and 0.836 in malignancy). Conclusions: No significant increase in the risk of developing symptomatic stroke and cancer was observed for the use of epoetin in current clinical practice in Japan. © 2010 Japanese Society of Nephrology.