Search

Your search keyword '"Hanzawa K"' showing total 219 results
Start Over Author "Hanzawa K"
219 results on '"Hanzawa K"'

1. First-principles Study of the RKKY Interaction and the Quadrupole Order in the Pr 1-2-20 systems PrT2Al20 (T=Ti, V)

Author

Iizuka, Y., Yamada, T., Hanzawa, K., and Ōno, Y.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Electronic states and quadrupole orders in the Pr 1-2-20 systems PrT2Al20 (T=Ti, V) are investigated on the basis of the first-principles calculations. The effective 196 orbital model is derived to reproduce the first-principles electronic structures of LaT2Al20 (T=Ti, V) without contribution from the Pr 4f electrons which are considered to be well localized and is employed to calculate the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions between quadrupole and octupole moments of the Pr ions. Within the random phase approximation for the RKKY Hamiltonian, the most divergent susceptibility is found to be the quadrupole one for the wave vector Q = (0,0,0) in the case of PrTi2Al20 while that for Q = (pi/a,0,pi/a) in the case of PrV2Al20 as consistent with experimental observations in the both cases which exhibit the ferro-quadrupole (FQ) and the antiferro-quadrupole (AFQ) orders, respectively. We also discuss the ordered states using the mean-field approximation and find that, in the case of PrTi2Al20, the 1st-order phase transition to the O20 FQ order with a tiny discontinuity takes place as predicted by the Landau theory. In the case of PrV2Al20, the system exhibits two distinct O22 AFQ orders, AFQ-I and AFQ-II, and shows subsequent two phase transitions, the 2nd-order one from normal to AFQ-I and the 1st-order one from AFQ-I to AFQ-II, that may be responsible for the double transitions observed by specific heat measurements., Comment: 6 pages, 6 figures

Published
2022
Full Text
View/download PDF

2. RKKY Interaction and Quadrupole Order in PrT2Al20 (T=Ti, V) Based on Effective 196 Orbital Model Extracted from First-Principles Calculation

Author

Iizuka, Y., Yamada, T., Hanzawa, K., and Ōno, Y.

Subjects
Condensed Matter - Strongly Correlated Electrons
Abstract

Electronic states and quadrupole orders in the 1-2-20 systems PrT2Al20 (T=Ti, V) are investigated on the basis of the first-principles band calculation. As the de Haas-van Alphen experiments reveal that the Pr-4f electrons in the systems are sufficiently localized and irrelevant for the Fermi surface, we derive the low-energy effective tight-binding models consists of 196 orbitals of conduction electrons so as to reproduce the first-principles electronic structures of LaT2Al20 (T=Ti, V) without contribution from the 4f electrons. Based on the effective models, we calculate the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the quadrupole moments of the Pr ions mediated by the conduction electrons. The obtained results indicate that the wave vector of the expected quadrupole order is Q=(0,0,0) for PrTi2Al20 while it is Q=(pi/a,pi/a,0) for PrV2Al20 as consistent with experimental observations in PrTi2Al20 and PrV2Al20 which exhibit ferro- and antiferro-quadrupole orders, respectively., Comment: 6 pages, 3 figures

Published
2019
Full Text
View/download PDF

3. First-Principles Study of the RKKY Interaction and the Quadrupole Order in the Pr 1-2-20 Systems PrT2Al20 (T = Ti, V)

Author

Iizuka, Y., Yamada, T., Hanzawa, K., and Ōno, Y.

Subjects
Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), FOS: Physical sciences, General Physics and Astronomy
Abstract

Electronic states and quadrupole orders in the Pr 1-2-20 systems PrT2Al20 (T=Ti, V) are investigated on the basis of the first-principles calculations. The effective 196 orbital model is derived to reproduce the first-principles electronic structures of LaT2Al20 (T=Ti, V) without contribution from the Pr 4f electrons which are considered to be well localized and is employed to calculate the Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions between quadrupole and octupole moments of the Pr ions. Within the random phase approximation for the RKKY Hamiltonian, the most divergent susceptibility is found to be the quadrupole one for the wave vector Q = (0,0,0) in the case of PrTi2Al20 while that for Q = (pi/a,0,pi/a) in the case of PrV2Al20 as consistent with experimental observations in the both cases which exhibit the ferro-quadrupole (FQ) and the antiferro-quadrupole (AFQ) orders, respectively. We also discuss the ordered states using the mean-field approximation and find that, in the case of PrTi2Al20, the 1st-order phase transition to the O20 FQ order with a tiny discontinuity takes place as predicted by the Landau theory. In the case of PrV2Al20, the system exhibits two distinct O22 AFQ orders, AFQ-I and AFQ-II, and shows subsequent two phase transitions, the 2nd-order one from normal to AFQ-I and the 1st-order one from AFQ-I to AFQ-II, that may be responsible for the double transitions observed by specific heat measurements., 6 pages, 6 figures

Published
2022

14. LIST OF CONTRIBUTERS

Author

Abe, S., primary, Adachi, K., additional, Aoki, K., additional, Bessho, K., additional, Bloch, D., additional, Chikazumi, S., additional, Date, M., additional, de Boer, F.R., additional, de Châtel, P.F., additional, de Groot, P., additional, de Jongh, L.J., additional, De Vos, G., additional, Eremenko, V.V., additional, Feldmann, P., additional, Foner, S., additional, Franse, J.J.M., additional, Frings, P.H., additional, Fujiwara, S., additional, Fukamichi, K., additional, Fukushima, Y., additional, Fukutani, H., additional, Gambino, R.J., additional, Gersdorf, R., additional, Guillot, M., additional, Gurtovoj, K.G., additional, Hanzawa, K., additional, Harada, I., additional, Harada, T., additional, Henkie, Z., additional, Herlach, F., additional, Higashi, K., additional, Hirabayashi, H., additional, Hiroyoshi, H., additional, Honda, M., additional, Hori, H., additional, Hoshi, A., additional, Ido, H., additional, Ikebe, M., additional, Isihara, A., additional, Isikawa, Y., additional, Iwasa, Y., additional, Jaccarino, V., additional, Janssen, P., additional, Kakudate, Y., additional, Kaneko, T., additional, Kasuya, T., additional, Katagiri, K., additional, Katsumata, K., additional, Kiko, G., additional, King, A.R., additional, Kobayashi, M., additional, Komatsubara, T., additional, Kotani, A., additional, Kunitomi, N., additional, Kuroda, N., additional, Kurosawa, K., additional, Kusakabe, M., additional, Lagutin, A.S., additional, Lee, Z.-H., additional, Leupold, M.J., additional, Liu, Zhi-Yi, additional, Marchand, A., additional, Markowski, P.J., additional, Maruyama, H., additional, Mashimo, T., additional, Matsui, M., additional, Mattens, W.C.M., additional, McGuire, T.R., additional, Menovsky, A., additional, Misu, A., additional, Miura, N., additional, Miura, S., additional, Miyajima, H., additional, Miyazaki, T., additional, Mollymoto, H., additional, Motizuki, K., additional, Motokawa, M., additional, Muller, F.A., additional, Muto, Y., additional, Nagayama, K., additional, Nakagawa, Y., additional, Nakamura, K., additional, Nakao, K., additional, Niitsuma, N., additional, Nishina, Y., additional, Noguchi, S., additional, Noto, K., additional, Okuda, K., additional, Ono, F., additional, Orbach, R., additional, Ozhogin, V.I., additional, Pan, Shiao-Thur, additional, Pauthenet, R., additional, Picoche, J.C., additional, Roeland, L.W., additional, Rub, P., additional, Rubin, L.G., additional, Saito, S., additional, Sakakibara, T., additional, Sato, K., additional, Satoh, T., additional, Schneider-Muntau, H.J., additional, Shen, Bao-Gen, additional, Shintomi, T., additional, Shiwa, Y., additional, Suematsu, H., additional, Sugiyama, K., additional, Suzuki, N., additional, Suzuki, T., additional, Takada, Y., additional, Takagi, S., additional, Takegahara, K., additional, Tanaka, K., additional, Tsuda, T., additional, Tsuge, S., additional, Tuchendler, J., additional, Vallier, J.C., additional, Voiron, J., additional, Wake, M., additional, Wang, Yi-Zhong, additional, Watanabe, K., additional, Weggel, R.J., additional, Williams, J.E.C., additional, Witters, J., additional, Wohlfarth, E.P., additional, Wolfrat, J.C., additional, Wu, Yong-Sheng, additional, Yamada, O., additional, Yamada, S., additional, Yamagishi, A., additional, Yamauchi, H., additional, Yanase, A., additional, Yang, Fu-Min, additional, Yashima, H., additional, Yasuoka, H., additional, Yoshida, M., additional, Yosida, T., additional, and Zhao, Xi-Chao, additional

Published
1983
Full Text
View/download PDF

26. CORE LOSS IN TURBINE GENERATORS: ANALYSIS OF NO-LOAD CORE LOSS BY 3D MAGNETIC FIELD CALCULATION.

Author

Wiak, S., Dems, M., Komęza, K., Nakahara, A., Takahashi, K., Ide, K., Kaneda, J., Hattori, K., Watanabe, T., Mogi, H., Kaido, C., Minematsu, E., and Hanzawa, K.

Abstract

Magnetic field analysis of no-load core loss in turbine generators is described. The losses in laminated steel sheets are calculated from the results of finite element magnetic field analysis. The additional losses in metal portions other than the steel sheets are also calculated. The sums of these losses were compared with the measured values for two generators and found to be 88% and 96% of the measured values. The results revealed that the additional losses made up a considerable part of the core losses. [ABSTRACT FROM AUTHOR]

Published
2006
Full Text
View/download PDF

31. Deep venous thrombosis among disaster shelter inhabitants following the March 2011 earthquake and tsunami in Japan: a descriptive study.

Author

Shibata, M., Hanzawa, K., Ueda, S., and Yambe, T.

Subjects
*VENOUS thrombosis risk factors, *ULTRASONIC imaging, *CHI-squared test, *CONFIDENCE intervals, *LEG, *RESEARCH methodology, *MULTIVARIATE analysis, *NATURAL disasters, *QUESTIONNAIRES, *T-test (Statistics), *VENOUS thrombosis, *LOGISTIC regression analysis, *RETROSPECTIVE studies, *DATA analysis software, *DESCRIPTIVE statistics, *ODDS ratio
Abstract

Objectives: A retrospective analysis of data collected during subject screening following Japan's March 2011 earthquake and tsunami was performed. We aimed to determine the incidence of deep venous thrombosis (DVT) among screened subjects and to identify risk factors associated with the development of DVT as independent variables. Methods: Calf ultrasonography was undertaken in 269 subjects living in 21 shelters in Miyagi prefecture during the one-month period immediately following the March 2011 disaster. Information regarding the health and risk factors of subjects was collected by questionnaire and assessment of physical signs. Results: Of the 269 evacuees screened, 65 (24%) met the criteria for calf DVT. We found lower limb trauma, reduced frequency of urination and sleeping in a vehicle to be independent positive predictors of DVT. Conclusions: Evacuees had an increased risk of developing DVT, associated with tsunami-related lower limb injury, immobility and dehydration. [ABSTRACT FROM AUTHOR]

Published
2014
Full Text
View/download PDF

38. Major factors of homologous blood transfusion in valvular heart operation with intraoperative autologous blood predonation in cases with difficulty in preoperative predonation.

Author

Sato K, Namura O, Hanzawa K, Kikuchi C, Takekubo M, Asami F, Wakabayashi T, Saito T, Homma T, Baba H, Hayashi J, Sato, Koichi, Namura, Osamu, Hanzawa, Kazuhiko, Kikuchi, Chizuo, Takekubo, Masaru, Asami, Fuyuki, Wakabayashi, Takashi, Saito, Takeshi, and Homma, Takayuki

Published
2010
Full Text
View/download PDF

42. Effects of exercise on erythrocytes in normal and splenectomised Thoroughbred horses.

Author

HANZAWA, K., KUBO, K., KAl, M., HIRAGA, A., and WATANABE, S.

Abstract

Summary Changes in erythrocyte quality during exercise were determined in 3 control ( Group C) and 3 splenectomised ( Group 5) horses that performed an incremental exercise test on a treadmill until the point of fatigue. Venous blood samples were drawn before the exercise test and immediately after warming-up and incremental exercise test. Incremental exercise increased erythrocyte count and haemoglobin concentration by 46 and 37% respectively in control horses and by 15 and 17% respectively in Group S animals. Packed cell volume (PCV) increased by 48% in controls but there was no change in Group S animals. Warming-up decreased mean cell volume (MCV), mean cell Hb (MCH) and mean cell Hb concentration (MCHC) by 9, 19 and 7% in control horses. Incremental exercise restored MCV and MCHC but MCH remained lower than the resting level. In Group S horses, warming-up and incremental exercise decreased MCV by 6 and 9% respectively, did not change MCH, but increased MCHC by 4 and 15% respectively. Incremental exercise increased erythrocyte density (ED) in Group C but not in Group S horses. Osmotic fragility of erythrocytes measured as the red cell haemolysis rates in 0.56% NaCl (HL) were significantly higher in Group C than in Group S horses regardless of exercise. Warming-up decreased HL by 7% in Group C vs 19% in Group S horses, but exercise increased HL by 26% in Group C vs 38% in Group S horses. These results suggest that: 1) exercise causes shrinking of erythrocytes; 2) erythrocyte indices are dependent on the intensity of the exercise; 3) release of erythrocytes from the spleen is associated with an increase in osmotic fragility; and 4) exercise changes osmotic fragility regardless of the release of erythrocytes from the spleen into circulation. [ABSTRACT FROM AUTHOR]

Published
1995
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results