1,457 results on '"T. Oikawa"'
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2. Appropriate growth models to describe early growth of Kejobong goat based on Growth Hormone (GH) gene sequence analysis
- Author
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S. Sutopo, D. A. Lestari, T. Oikawa, T. Konno, E. Purbowati, A. Setiaji, and E. Kurnianto
- Subjects
gh ,goat ,growth analysis ,mathematical models ,snp ,Animal culture ,SF1-1100 ,Veterinary medicine ,SF600-1100 - Abstract
The objectives of this study were to reveal appropriate growth models describing early growth of Kejobong goat based on Growth Hormone (GH) gene sequence analysis. A total of 35 DNA samples and 1.960 records of quantitative traits of Kejobong goat were collected. The exon 3 of GH gene was amplified and was sequenced to determine the SNP. Body weight and body measurements of the goats were taken at 0-14 weeks of age. Four non-linear growth models were applied for analysis of growth to compare growth performance of different genotypes by Non-Linear Mixed Model. A non-synonymous mutation (g1170AG) genotyped into GG, AG and AA was significantly associated with growth traits. Animals with heterozygous genotype AG showed higher growth traits than animals with homozygous genotype AA. Nonetheless, animals with homozygous genotype GG had the same growth traits with those animals with heterozygous genotype AG and homozygous genotype AA. The most fitted model for describing body weight was Von Bertalanffy model, while for describing wither height and hip height was Brody model. SNP at exon 3 of the GH gene can be used as genetic marker for improvement of growth traits of Kejobong goats.
- Published
- 2021
- Full Text
- View/download PDF
3. Large-scale micromagnetic simulation of Nd-Fe-B sintered magnets with Dy-rich shell structures
- Author
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T. Oikawa, H. Yokota, T. Ohkubo, and K. Hono
- Subjects
Physics ,QC1-999 - Abstract
Large-scale micromagnetic simulations have been performed using the energy minimization method on a model with structural features similar to those of Dy grain boundary diffusion (GBD)-processed sintered magnets. Coercivity increases as a linear function of the anisotropy field of the Dy-rich shell, which is independent of Dy composition in the core as long as the shell thickness is greater than about 15 nm. This result shows that the Dy contained in the initial sintered magnets prior to the GBD process is not essential for enhancing coercivity. Magnetization reversal patterns indicate that coercivity is strongly influenced by domain wall pinning at the grain boundary. This observation is found to be consistent with the one-dimensional pinning theory.
- Published
- 2016
- Full Text
- View/download PDF
4. Seasonal change in CO2 and H2O exchange between grassland and atmosphere
- Author
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N. Saigusa, S. Liu, T. Oikawa, and T. Watanabe
- Subjects
Science ,Physics ,QC1-999 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
The seasonal change in CO2 flux over an artificial grassland was analyzed from the ecological and meteorological point of view. This grassland contains C3 and C4 plants; the three dominant species belonging to the Gramineae; Festuca elatior (C3) dominated in early spring, and Imperata cylindrica (C4) and Andropogon virginicus (C4) grew during early summer and became dominant in mid-summer. CO2 flux was measured by the gradient method, and the routinely observed data for the surface-heat budget were used to analyze the CO2 and H2O exchange between the grassland and atmosphere. From August to October in 1993, CO2 flux was reduced to around half under the same solar-radiation conditions, while H2O flux decreased 20% during the same period. The monthly values of water use efficiency, i.e., ratio of CO2 flux to H2O flux decreased from 5.8 to 3.3 mg CO2/g H2O from August to October, the Bowen ratio increased from 0.20 to 0.30, and the ratio of the bulk latent heat transfer coefficient CE to the sensible heat transfer coefficient CH was maintained around 0.40-0.50. The increase in the Bowen ratio was explained by the decrease in air temperature from 22.3 °C in August to 16.6 °C in October without considering biological effects such as stomatal closure on the individual leaves. The nearly constant CE/CH ratios suggested that the contribution ratio of canopy resistance to aerodynamic resistance did not change markedly, although the meteorological conditions changed seasonally. The decrease in the water use efficiency, however, suggested that the photosynthetic rate decreased for individual leaves from August to October under the same radiation conditions. Diurnal variations of CO2 exchange were simulated by the multi-layer canopy model taking into account the differences in the stomatal conductance and photosynthetic pathway between C3 and C4 plants. The results suggested that C4 plants played a major role in the CO2 exchange in August, the contribution of C4 plants decreased in September, and daily variations of CO2 exchange were mainly due to C3 plants in October. The results also suggested that the decrease in the net canopy CO2 exchange from August to October was induced partly by the decrease of net photosynthesis on the individual leaves in both C4 and C3 plants, which could be due to aging of the leaves.
- Published
- 1996
- Full Text
- View/download PDF
5. Seasonal change in CO2 and H2O exchange between grassland and atmosphere
- Author
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T. Oikawa, S. Liu, N. Saigusa, and T. Watanabe
- Subjects
Science ,Physics ,QC1-999 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
The seasonal change in CO2 flux over an artificial grassland was analyzed from the ecological and meteorological point of view. This grassland contains C3 and C4 plants; the three dominant species belonging to the Gramineae; Festuca elatior (C3) dominated in early spring, and Imperata cylindrica (C4) and Andropogon virginicus (C4) grew during early summer and became dominant in mid-summer. CO2 flux was measured by the gradient method, and the routinely observed data for the surface-heat budget were used to analyze the CO2 and H2O exchange between the grassland and atmosphere. From August to October in 1993, CO2 flux was reduced to around half under the same solar-radiation conditions, while H2O flux decreased 20% during the same period. The monthly values of water use efficiency, i.e., ratio of CO2 flux to H2O flux decreased from 5.8 to 3.3 mg CO2/g H2O from August to October, the Bowen ratio increased from 0.20 to 0.30, and the ratio of the bulk latent heat transfer coefficient CE to the sensible heat transfer coefficient CH was maintained around 0.40-0.50. The increase in the Bowen ratio was explained by the decrease in air temperature from 22.3 °C in August to 16.6 °C in October without considering biological effects such as stomatal closure on the individual leaves. The nearly constant CE/CH ratios suggested that the contribution ratio of canopy resistance to aerodynamic resistance did not change markedly, although the meteorological conditions changed seasonally. The decrease in the water use efficiency, however, suggested that the photosynthetic rate decreased for individual leaves from August to October under the same radiation conditions. Diurnal variations of CO2 exchange were simulated by the multi-layer canopy model taking into account the differences in the stomatal conductance and photosynthetic pathway between C3 and C4 plants. The results suggested that C4 plants played a major role in the CO2 exchange in August, the contribution of C4 plants decreased in September, and daily variations of CO2 exchange were mainly due to C3 plants in October. The results also suggested that the decrease in the net canopy CO2 exchange from August to October was induced partly by the decrease of net photosynthesis on the individual leaves in both C4 and C3 plants, which could be due to aging of the leaves.
6. Construction of a Database of HREM Images on the World Wide Web
- Author
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D Shindo, A Taniyama, Y Murakami, K Hiraga, T Oikawa, and A I Kirkland
- Published
- 2022
7. High-precision solidification simulation by estimating heat transfer coefficients through data assimilation
- Author
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Y Natsume, T Oikawa, and M Ohno
- Subjects
General Medicine - Abstract
Solidification analysis is important for accurately predicting casting processes. A high-precision casting simulation requires accurate data of the physical properties of materials and heat transfer parameters. In particular, the heat transfer coefficient is a major parameter influencing the casting simulation results. Because the heat transfer coefficient is not uniquely determined by the material, it is typically estimated by trial and error, which requires considerable time for accurate estimations. Therefore, we developed a method to quickly estimate the heat transfer coefficient in a casting process by combining data assimilation and solidification simulations. With this method, the time-dependent heat transfer coefficient can be estimated in an appropriate and easy manner. To reproduce the 3D temperature distribution in a casting with high accuracy, we developed a method to estimate multiple heat transfer coefficients simultaneously by combining data assimilation and 3D solidification simulation. Al–5 mass% Si alloy was cast into a sand mold with a casting size of 30 mm × 30 mm × 100 mm, and the temperature was measured at five points in the casting to obtain a cooling curve. Two cooling curves corresponding to locations of 5 mm from the casting wall were used to estimate the two heat transfer coefficients on the side and bottom surfaces, which were simultaneously estimated by data assimilation. The results confirmed that all the five cooling curves could be reproduced with a high accuracy and that high-precision casting simulation was possible.
- Published
- 2023
8. Visualization and Analysis of Temporal and Steady-State Gas Concentration in Process Chamber Using 70-dB SNR 1,000 fps Absorption Imaging System
- Author
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Y. Sakai, Y. Shiba, T. Inada, T. Goto, T. Suwa, T. Oikawa, A. Hamaya, A. Sutoh, T. Morimoto, Y. Shirai, S. Sugawa, and R. Kuroda
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Industrial and Manufacturing Engineering ,Electronic, Optical and Magnetic Materials - Published
- 2023
9. Polarization Characterization of LEDs by Stokes Parameters Measurements
- Author
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T Saito, T Sutani, K Kiyono, and T Oikawa
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History ,Computer Science Applications ,Education - Abstract
Stokes parameters have been measured by using a polarimeter consisting of a rotating phase plate before a fixed polarizer for bullet-shaped red, green and blue LEDs at 3 different directions of 0°, 45° and 90° from the principal axis. The degree of polarization is minimum at the observation angle 0° (observed head-on) for all colors as expected but has non-zero values (1-9%). As for the possible cause for the partial polarization, it is likely to be brought by striae inside the transparent epoxy resin that can be easily visible. Data at observation angle 90° have features common for all colors; the degree of polarization is highest, the long axis azimuth of the polarization ellipse is nearly in the horizontal direction, and the ellipticity is small. These features can be explained as follows. At observation angle 90°, only small fraction of the beam emitted nearly horizontally is detected possibly through multireflection (the plane of incidence is in the vertical plane) inside the top- and bottom-surfaces (in the horizontal direction) of the chip substrate. Since the reflectance for s-polarization (horizontal component) is higher than that for p-polarization, the emerging beam becomes horizontally polarized. The hypotheses that geometrical asymmetry generates polarization is experimentally supported.
- Published
- 2022
10. Examination of Factors Influencing the Success Rates of an In Vitro Chemosensitivity Test for Lung Cancer Using Collagen Gel Droplet-Embedded Cultures
- Author
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Y, Takahara, primary, Y, Kawasaki, additional, R, Kato, additional, S, Shinomiya, additional, T, Oikawa, additional, and S, Mizuno, additional
- Published
- 2019
- Full Text
- View/download PDF
11. Interface challenges as part of the ITER plasma control system design
- Author
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Franco Gandini, M. Schneider, T. Jun, M. A. Henderson, Inho Song, L. Zabeo, Y. Gribov, Joseph Snipes, George Vayakis, S. Maruyama, P. de Vries, A. Vergara, C. Watts, Lennart Svensson, P. U. Lamalle, Y. Yu, A. Winter, Neil Mitchell, Michael Lehnen, and T. Oikawa
- Subjects
Relation (database) ,Computer science ,Mechanical Engineering ,Interface (computing) ,Control (management) ,computer.software_genre ,01 natural sciences ,010305 fluids & plasmas ,Set (abstract data type) ,Consistency (database systems) ,Nuclear Energy and Engineering ,0103 physical sciences ,Limit (music) ,Systems engineering ,General Materials Science ,010306 general physics ,Actuator ,computer ,Civil and Structural Engineering ,Data integration - Abstract
The ITER Plasma Control System (PCS) approaching the second phase of development is now more deeply investigating alternative solutions for the various controls aimed at operations up to 15MA with low auxiliary heating in L-mode. The control functions in the PCS are strictly linked to the performance of the ITER actuators and diagnostics. The capabilities of those systems need to be carefully validated against the control needs. System and performance requirements shall be consistent with the control schemas and where limitations or restrictions are identified, it is necessary to provide alternative solutions. To guarantee this consistency, a set of interface documents is being prepared. Those interfaces for each of the plant systems that can impact the PCS activities detail the requirements specifically needed for control and report also the functional relationship between the two systems. The PCS has also to consider areas not actively part of plasma control that might affect or limit PCS operations (i.e. forces in the superconducting coils). This paper reports the main outcome from the interfaces definition. The actuator boundaries and plant systems constraints impacting the PCS design will be presented. For the sensors the challenge is the derivation of real-time measurement requirements in relation to the separate diagnostic requirements and their respective interface with the PCS. The complex organization of data integration with the PCS will be discussed.
- Published
- 2017
12. Accelerated anaerobic release of K, Mg and P from surplus activated sludge for element recovery and struvite formation inhibition
- Author
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Teruyuki Umita, A. Sato, Ayumi Ito, Nao Ishikawa, H. Kawakami, M. Ito, and T. Oikawa
- Subjects
Environmental Engineering ,Struvite ,Potassium ,0208 environmental biotechnology ,chemistry.chemical_element ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,chemistry.chemical_compound ,Magnesium ,Anaerobiosis ,0105 earth and related environmental sciences ,Water Science and Technology ,Sewage ,Waste management ,Chemistry ,Phosphorus ,020801 environmental engineering ,Anaerobic digestion ,Activated sludge ,Sodium acetate ,Anaerobic exercise ,Waste disposal ,Nuclear chemistry - Abstract
Accelerated release of potassium (K), magnesium (Mg) and phosphorus (P) from surplus activated sludge (SAS) was investigated to develop a new system for the recovery of the elements. Anaerobic cultivation of SAS during 24 h released 78% of K and about 50% of Mg and P from SAS more effectively compared to aerobic cultivation (K: 40%, Mg: 15%, P: 15%). Furthermore, the addition of sodium acetate as an organic carbon source remarkably accelerated the release of K, Mg and P from SAS under anaerobic condition. However, no increase in the maximum release efficiencies was observed. The elements released from SAS could be transferred to separate liquid with the existing mechanical thickener and be recovered as MgKPO4 by some additional process. Furthermore, the removal of the elements from SAS would inhibit the formation of struvite causing the blockage of sludge transport pipe after anaerobic digestion process of thickened sludge.
- Published
- 2017
13. Scattered distribution of oxygen vacancies in anatase TiO2 film; first-principles study on VMCO-memory characteristics
- Author
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T. Oikawa, R. Nagasawa, M. Araidai, K. Shiraishi, and T. Nakayama
- Subjects
Anatase ,Materials science ,Distribution (number theory) ,chemistry ,Condensed matter physics ,chemistry.chemical_element ,Oxygen - Published
- 2019
14. Band Gap Narrowing of 2-D Ultra-Thin MgO Graphene-Like Sheets
- Author
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Nurhanna Badar, Roshidah Rusdi, D. T. Mustaffa, Norlida Kamarulzaman, T. Oikawa, Kelimah Elong, H. Furukawa, Muhd Firdaus Kasim, and Nor Fadilah Chayed
- Subjects
010302 applied physics ,Imagination ,Thesaurus (information retrieval) ,Materials science ,Graphene ,Band gap ,media_common.quotation_subject ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Engineering physics ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,0103 physical sciences ,0210 nano-technology ,Science, technology and society ,media_common - Published
- 2016
15. Current progresses in the ovum pick-up(OPU)for in vitro embryo production in cattle : from lab-research to on-farm technology
- Author
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T. Oikawa
- Subjects
business.industry ,Production (economics) ,Embryo ,Current (fluid) ,Biology ,business ,Biotechnology - Published
- 2017
16. Performance of first mirrors for divertor impurity monitor in ITER: compensation of misalignment and effect of beam divergence
- Author
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Shin Kajita, H. Ogawa, S. I. Kitazawa, T. Oikawa, and E. Veshchev
- Subjects
Optics ,Materials science ,business.industry ,Impurity ,Divertor ,business ,Instrumentation ,Mathematical Physics ,Compensation (engineering) ,Beam divergence - Published
- 2020
17. Superovulatory response in Japanese Black cows receiving a single subcutaneous porcine follicle–stimulating hormone treatment or six intramuscular treatments over three days
- Author
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N. Nishimoto, F. Sano, S. Hiraizumi, H. Nishinomiya, O. Ishiyama, T. Kurahara, N. Sakagami, T. Oikawa, Y. Hasegawa, Y. Hashiyada, and O. Nishino
- Subjects
medicine.medical_specialty ,Dose-Response Relationship, Drug ,Equine ,business.industry ,Injections, Subcutaneous ,medicine.medical_treatment ,Superovulation ,Absorption (skin) ,Injections, Intramuscular ,Drug Administration Schedule ,Follicle-stimulating hormone ,Endocrinology ,Animal science ,Food Animals ,Internal medicine ,medicine ,Animals ,Cattle ,Female ,Animal Science and Zoology ,Follicle Stimulating Hormone ,Small Animals ,business ,Saline - Abstract
To reduce labor for superovulation treatment by twice-daily intramuscular (im) administration of FSH for more than 3 to 4 days, we investigated the superovulatory responses of Japanese Black cows to porcine FSH (pFSH) used as a single subcutaneous (sc) administration at two different doses in two different volumes of saline. In experiment 1, 20 Armour units (AU) of pFSH dissolved in either 10 mL (treatment A; n = 14) or 50 mL (treatment B; n = 14) of saline was administered subcutaneously in the neck region. In experiment 2, 30 AU of pFSH dissolved in either 10 mL (treatment C; n = 15) or 50 mL (treatment D; n = 15) of saline was administered subcutaneously in the neck region. The control animals in experiment 1 (n = 14) and experiment 2 (n = 15) received 20 AU of pFSH administered intramuscularly twice daily in decreasing doses for more than 3 days. In experiment 1, mean (±SEM) numbers of CL (15.4 ± 2.5, 18.1 ± 3.4, and 17.2 ± 2.6), total number of ova and embryos (12.9 ± 1.4, 15.9 ± 3.5, and 16.2 ± 2.8), and transferable embryos (7.5 ± 2.0, 10.4 ± 2.8, and 8.0 ± 2.1) did not differ among treatments A, B, and control. In experiment 2, mean (±SEM) numbers of CL (20.5 ± 4.3, 20.4 ± 2.7, and 20.1 ± 3.4), total number of ova and embryos (21.7 ± 4.2, 17.3 ± 3.4, and 16.5 ± 3.2), and transferable embryos (8.1 ± 1.6, 9.3 ± 2.2, and 9.5 ± 1.9) did not differ among treatments C, D, and control. Although there were no differences in serum pFSH concentrations among the three treatments at each of the time points in experiment 1, in experiment 2, the serum pFSH concentration at 6 and 8 hours after pFSH administration in treatment C (3.1 ± 0.8, 2.7 ± 0.5 ng/mL, mean ± SEM) was significantly greater (P
- Published
- 2015
18. Effect of Two month Intervention to Improve Physical Activity of Evacuees in Temporary Housing after the Great East Japan Earthquake: Pilot Study
- Author
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T. Oikawa, Moriyama N, Urabe Y, Noriaki Maeda, and S. Onoda
- Subjects
Self-efficacy ,Gerontology ,Intervention program ,business.industry ,Intervention (counseling) ,Triaxial accelerometer ,Pedometer ,Physical activity ,Medicine ,business ,Omics - Abstract
Objective: This study aims to clarify effects of intervention to improve the physical activity of elderly evacuees in temporary housing after The Great East Japan Earthquake, which occurred on March 11, 2011. Methods: A total of 15 subjects (5 men and 10 women) underwent a two-month intervention program, which consisted of multiple techniques including education, practice, and feedback, all of which were aimed to increase patients’ physical activity levels. Changes in physical activity levels were gauged according to the number of walking steps recorded with a triaxial accelerometer, or pedometer. Age, gender, and stage of self-efficacy were analyzed to determine which characteristics made it more likely for respondents to add more than 10% to their number of steps in the first 2 weeks and in the last 2 weeks of the study. Results: Three out of fifteen subjects (20.0%) increased their number of steps by more than 10% in postintervention. Males, and those who had smaller levels of physical activity pre-intervention were more likely to improve their number of steps (p
- Published
- 2017
19. Removal of radioactive iodine and cesium in water purification
- Author
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Y. Kobayashi, S. Kitada, Y. Shinoda, K. Nakamura, S. Watanabe, T. Iwamoto, K. Nagai, M. Matsuki, M. Sasaki, K. Tsuchiya, and T. Oikawa
- Subjects
Radionuclide ,Powdered activated carbon treatment ,Sedimentation (water treatment) ,Radiochemistry ,chemistry.chemical_element ,Ocean Engineering ,Portable water purification ,Iodine ,Pollution ,Purified water ,chemistry ,medicine ,Water treatment ,Water Science and Technology ,Activated carbon ,medicine.drug - Abstract
Radioactive iodine, one of the radionuclides released in the nuclear power plant accident on 11 March 2011, was detected in purified water at water purification plants (WPPs). However, information about removal of radioactive materials in actual water purification process was limited. Therefore, we investigated the removal of radioactive materials (iodine and cesium) immediately after the detection. It is found that non-radioactive iodine in water could be removed by the combined use of pre-chlorination and powdered activated carbon (PAC) treatment. The same result was also obtained in terms of radioactive iodine. Removal of non-radioactive iodine in WPPs was also investigated. Approximately, 60% of iodine was removed by combination of pre-chlorination (0.5–1.0 mg/L) and PAC (15–30 mg/L) in coagulation and sedimentation processes. In water purification process, cesium was mostly removed by coagulation and sedimentation; hence, radioactive cesium was not detected in purified water. It was confirmed...
- Published
- 2014
20. MON-101 APPLICATION OF A TELEMEDICAL METHOD TO MAINTENANCE HEMODIALYSIS THERAPY IN A SPARSELY POPULATED AREA
- Author
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K. Tanaka, T. Oikawa, J. Kazama, Y. Aoyagi, A. Oda, and A. Nakajima
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Populated area ,Nephrology ,business.industry ,Medicine ,Medical emergency ,Maintenance hemodialysis ,business ,medicine.disease - Published
- 2019
21. Structural and elemental analysis of iron and indium doped zinc oxide by spectroscopic imaging in Cs-corrected STEM
- Author
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T. Oikawa, Werner Mader, H. Schmid, and Eiji Okunishi
- Subjects
Materials science ,Dopant ,Doping ,Analytical chemistry ,General Physics and Astronomy ,chemistry.chemical_element ,Cell Biology ,Electron ,Zinc ,Crystallography ,chemistry ,Structural Biology ,Elemental analysis ,Monolayer ,Scanning transmission electron microscopy ,General Materials Science ,Indium - Abstract
ZnO with additions of Fe2O3 or In2O3 shows characteristic inversion domain structures. ZnO domains are separated by two types of inversion domain boundaries (IDBs): basal b-IDBs parallel to (0 0 0 1) planes, and complementary pairs of three possible variants of pyramidal p-IDBs parallel to { 2 1 ¯ 1 ¯ 5 } lattice planes. The structure and composition of IDBs were investigated in a sophisticated aberration-corrected scanning transmission electron microscope (probe-corrected TEM/STEM). It is shown that Fe and In additions are essentially located in monolayers within the IDBs, and EELS electron spectroscopic imaging (ESI) as well as EDS spectroscopic imaging by X-rays (SIX) are capable of rapidly mapping the element distribution. With solid solubility of trivalent dopant species well below 1 at.% within ZnO domains, the lateral spacings of b-IDBs are inversely proportional to the dopant concentration. Quantification of data acquired by ESI and SIX from well defined sample regions in STEM both confirm the assumption of one full monolayer of dopants per IDB. Atom columns of cations are well resolved in HAADF STEM imaging; experimental contrast intensities are approximately proportional to Z1.6. Furthermore, annular bright-field (ABF)-STEM imaging is capable of resolving oxygen columns even in thick sample regions, thus providing highly localized information on atom positions and lattice distortions, and enables the construction of more reliable structure models of IDBs in doped ZnO.
- Published
- 2012
22. Aging and immunity (PP-105)
- Author
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M. Li, T. Kojima, C. Koshide, Mar Souto Romero, Y. Ueda, D. Kim, C. J. Van De Wiele, C. Tan, B. Lasareishvili, Karen L. Brown, I. Pilipovic, Y. Katakura, K. Kishihara, J. Sales, R. L. Riley, M. Tominaga, G. Wathne, T. Hayashi, N. Abraham, J. Schrezenmeir, V. Niborski, T. K. Teague, S. van der Werf, D. Kosec, W. Lee, M. Pachówka, S. A. Valkenburg, J. Makula, M. Tanigawa, Moira E. Bruce, M. Perisic, K. Yoshida, S. Yang, D. Jung, J. Kim, T. Oikawa, Ana Marie Landin, M. Fukui, B. Shan, Z. Stojic-Vukanic, D. Jin, M. Iobadze, A. A. Taylor, T. Chikovani, N. Kikodze, K. Nishioka, E. Muso, M. Wahi, Neil A. Mabbott, N. Arsenovic-Ranin, L. Zhao, K. Hirokawa, H. Kojima, P. C. Doherty, G. Hasegawa, N. Pantsulaia, N. Nakamura, Y. Kikuchi, C. Park, M. Kim, M. Davenport, M. Inaba, K. Okazaki, K. Nakachi, Y. Hwang, K. Radojevic, G. Leposavic, S. Ikehara, T. Fujiki, G. Korczak-Kowalska, T. Hosokawa, J. H. Marino, T. Yoshikawa, K. Suzuki, S. Hoshino, I. Pantsulaia, S. Fujita, T. Ito-Ihara, M. Hosono, K. Kedzierska, V. Venturi, K. Nakajima, K. Murata, Alain Diaz, K. Yagi, E. Guillemard, V. Pesic, J. Kang, J. Shin, H. Kunimoto, Daniela Frasca, S. Hong, S. Vaudaine, Y. Kushida, Y. Kusunoki, M. Wachi, M. Touma, B. K. Davis, K. Uno, Bonnie B. Blomberg, and M. Utsuyama
- Subjects
business.industry ,Immunity ,Immunology ,Immunology and Allergy ,Medicine ,General Medicine ,business - Published
- 2010
23. Genetic parameters for preweaning and early growth traits in Berkshire pigs when creep feeding is used
- Author
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Y. Tatsukawa, Masamitsu Tomiyama, H. Mori, T. Oikawa, and T. Kanetani
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Male ,Veterinary medicine ,Swine ,Population ,Weaning ,Breeding ,Environment ,Biology ,Quantitative trait locus ,Weight Gain ,Genetic correlation ,Quantitative Trait, Heritable ,Animal science ,Genetics ,Animals ,Birth Weight ,education ,Weaning weight ,Selection (genetic algorithm) ,education.field_of_study ,Models, Genetic ,General Medicine ,Animal Feed ,Creep feeding ,Animals, Suckling ,Female ,Animal Science and Zoology ,Purebred ,Food Science - Abstract
The objective of this study was to find optimal traits for inclusion in selection criteria by estimating genetic parameters for direct genetic, maternal genetic, and common environmental effects for growth traits before 60 d of age and for the number of teats under an open breeding population, and to evaluate genetic relationships for traits at 60 d of age. Records of 2,344 male and 2,204 female purebred Berkshire pigs were analyzed. For BW at 14 d of age and for weaning weight, the heritabilities of a direct genetic effect were greater than those of a maternal genetic effect. This result is contrary to previous results showing a gradual decrease in the maternal genetic effect and an increase in the direct genetic effect up to weaning. The positive genetic correlations between direct and maternal genetic effects for BW at 14 d of age and weaning weight are clearly contrary to other reports. This phenomenon seems to be caused by creep feeding begun just after the birth of the piglets and maintained throughout the preweaning period in this Berkshire population.
- Published
- 2010
24. Improvement of indigenous cattle to modern Japanese Black (Wagyu) cattle
- Author
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T. Oikawa
- Subjects
Veterinary medicine ,General Medicine ,General Chemistry ,Biology ,Wagyu cattle ,Indigenous - Published
- 2018
25. Analysis of Non-Genetic Factors Influencing Reproductive Traits of Japanese Black Heifer
- Author
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T. Oikawa and A. Setiaji
- Subjects
Biology - Published
- 2018
26. Genetic parameters for measures of residual feed intake and growth traits in seven generations of Duroc pigs
- Author
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H. Kadowaki, T. Shibata, M. A. Hoque, T. Oikawa, and Keiichi Suzuki
- Subjects
General Veterinary ,Feed consumption ,Restricted maximum likelihood ,business.industry ,Heritability ,Biology ,Loin ,Genetic correlation ,Biotechnology ,Animal model ,Animal science ,Animal Science and Zoology ,Intramuscular fat ,Residual feed intake ,business - Abstract
Residual feed intake (RFI) represents the deviation of the actual feed consumption of an animal from that predicted from combination of growth traits. Data on 1642 Duroc (380 boars, 868 gilts, and 394 barrows) pigs in seven generations were used to estimate genetic parameters for measures of RFI, daily feed intake (FI), average daily gain (ADG), backfat (BF), and loin eye area (LEA). Four measures of RFI were estimated from models that included initial test age and weight, and ADG (RFI1); initial test age and weight, ADG, and BF (RFI2); initial test age and weight, ADG and LEA (RFI3); and initial test age and weight, ADG, BF, and LEA (RFI4). Genetic parameters were estimated using an animal model by the REML method. Heritability estimates for measures of RFI were moderate (ranged from 0.22 to 0.38). The corresponding estimates for FI, ADG, and LEA were also moderate (ranging from 0.45 to 0.49), while the estimate for BF was high (0.72). Genetic correlations of FI with ADG (0.84) and BF (0.67) were high. LEA negatively correlated with FI (− 0.42), ADG (− 0.11) and BF (− 0.44). Genetic correlations of BF with measures of RFI were higher when BF was not included in the estimation of RFI (0.77 with RFI1 and 0.76 with RFI3 vs. 0.11 with RFI2 and 0.07 with RFI4). Genetic correlations of LEA with measures of RFI were all negative (ranged from − 0.30 to − 0.60). Selection for ADG, LEA, BF, and intramuscular fat has resulted in small but favourable genetic changes in measures of RFI. Phenotypic correlations between measures of RFI were zero, and genetic correlations between them were low (0.17 to 0.23). FI was strongly correlated with all the measures of RFI, both genetically (ranged from 0.56 to 0.77) and phenotypically (ranged from 0.56 to 0.66). The results suggested that selection against RFI may cause a reduction in FI. BF should also decrease, and LEA should increase. The amount of change in BF or LEA would vary depending on whether RFI was adjusted for BF.
- Published
- 2009
27. Effects of ferromagnetic components on energetic ion confinement in ITER
- Author
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Hajime Urano, T. Oikawa, Johnny Lönnroth, Kouji Shinohara, G. Saibene, Naoyuki Oyama, Vassili Parail, and Yutaka Kamada
- Subjects
Physics ,Tokamak ,Toroid ,Condensed matter physics ,Mechanical Engineering ,Ripple ,Fusion power ,Blanket ,law.invention ,Magnetic field ,Nuclear physics ,Amplitude ,Nuclear Energy and Engineering ,Ferromagnetism ,law ,General Materials Science ,Civil and Structural Engineering - Abstract
By using a fully three dimensional magnetic field orbit-following Monte-Carlo code, the energetic ion confinement was investigated for the current conceptual design of the ferromagnetic components in ITER which will be employed for reducing the toroidal magnetic field (TF) ripple. The ferromagnetic insert is effective in the reference standard scenario with Q = 10 (Scenario No. 2) and steady state scenario with Q = 5 (Scenario No. 4) to improve the energetic ion confinement. Over-compensation appears at half of the full toroidal magnetic field and its effect becomes stronger when the quantity of the ferromagnetic insert is increased in order to more reduce the TF ripple at the full toroidal magnetic field. Though the current design is acceptable, whether to increase the ferromagnetic insert to achieve lower TF ripple amplitude at the full field operation depends on how prospected are possibilities of lower field operations. Planned test blanket modules do not induce large loss (
- Published
- 2009
28. Genetic parameters for measures of energetic efficiency of bulls and their relationships with carcass traits of field progeny in Japanese Black cattle1
- Author
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M. Hosono, Keiichi Suzuki, T. Oikawa, and M. A. Hoque
- Subjects
education.field_of_study ,Marbled meat ,Sire ,Population ,General Medicine ,Beef cattle ,Heritability ,Biology ,Feed conversion ratio ,Genetic correlation ,Animal science ,Genetics ,Animal Science and Zoology ,Residual feed intake ,education ,Food Science - Abstract
Records on 514 bulls from the sire population born from 1978 to 2004, and on 22,099 of their field progeny born from 1997 to 2003 with available pedigree information (total number = 124,458) were used to estimate genetic parameters for feed intake and energy efficiency traits of bulls and their relationships with carcass traits of field progeny. Feed intake and energetic efficiency traits were daily feed intake, TDN intake, feed conversion ratio (FCR), TDN conversion ratio (TDNCR), residual feed intake (RFI), partial efficiency of growth, relative growth rate, and Kleiber ratio. Progeny carcass traits were carcass weight (CWT), yield estimate, ribeye area, rib thickness, subcutaneous fat thickness (SFT), marbling score (MSR), meat color standard (MCS), fat color standard (FCS), and meat quality grade. All measures of feed intake and energetic efficiency were moderately heritable (ranged from 0.24 to 0.49), except for partial efficiency of growth and relative growth rate, which were high (0.58) and low (0.14), respectively. The phenotypic and genetic correlations between FCR and TDNCR were >or=0.93. Selection for Kleiber ratio will improve all of the energetic efficiency traits with no effect on feed intake measures (daily feed intake and TDN intake). The genetic correlations of FCR, TDNCR, and RFI of bulls with most of the carcass traits of their field progeny were favorable (ranged from -0.24 to -0.72), except with fat color standard (no correlation), MCS, and SFT. Positive (unfavorable) genetic correlations of MCS with FCR, TDNCR, and RFI (0.79, 0.70, and 0.51, respectively) were found. The SFT was negatively genetically correlated with FCR and TDNCR (-0.32 and -0.20, respectively); however, the genetic correlation between RFI and SFT was not significantly different from zero (r(g) = -0.08 +/- 0.12). Favorable correlated responses in CWT, yield estimate, ribeye area, rib thickness, MSR, and meat quality grade would be predicted for selection against any measure of energetic efficiency. The correlated responses in CWT and MSR of progeny were greater for selection against RFI than for selection against any other energetic efficiency trait. Results of this study indicate that RFI should be preferred over other measures of energetic efficiency to include in selection programs.
- Published
- 2009
29. Laser-induced crystal growth of nonlinear optical Ba3Ti3O6(BO3)2on glass surface
- Author
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Tsuyoshi Honma, Takayuki Komatsu, and T. Oikawa
- Subjects
Diffraction ,Materials science ,Laser scanning ,business.industry ,Scattering ,Crystal system ,Crystal growth ,General Chemistry ,Condensed Matter Physics ,Laser ,Molecular physics ,law.invention ,Wavelength ,Optics ,law ,General Materials Science ,Crystallization ,business - Abstract
Nonlinear optical Ba3Ti3O6(BO3)2 crystals were patterned on the surface of CuO (1 mol%)-doped 40BaO-40TiO2-20B2O3 glass by irradiations of continuous-wave Nd:YAG (wavelength: λ=1064 nm) and Yb:YVO4 (λ=1080 nm) lasers. Laser energies absorbed by Cu2+ ions were transferred to the lattice system through a nonradiative relaxation process, consequently heating the glass and inducing local crystallizations. For the lines patterned by Yb:YVO4 laser irradiations with a power of 1 W and a scanning speed of 20 μm/s, a c-axis orientation of Ba3Ti3O6(BO3)2 crystals along the laser scanning direction is proposed from measurements of X-ray diffraction analyses, polarized optical photographs, polarized micro-Raman scattering spectra, and azimuthal dependence of second harmonic generations. The laser-induced crystallization technique is found to be applied successfully for the spatially selective patterning of nonlinear optical Ba3Ti3O6(BO3)2 crystals in glass. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
- Published
- 2008
30. Effect of Two month Intervention to Improve Physical Activity of Evacuees in Temporary Housing after the Great East Japan Earthquake: Pilot Study
- Author
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N, Moriyama, primary, Y, Urabe, additional, S, Onoda, additional, N, Maeda, additional, and T, Oikawa, additional
- Published
- 2017
- Full Text
- View/download PDF
31. Simulation of the hybrid and steady state advanced operating modes in ITER
- Author
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T. Oikawa, A.A. Tucillo, M. Schneider, Tomonori Takizuka, F. Imbeaux, M. Murakami, G. Giruzzi, Nobuhiko Hayashi, T.C. Luce, E. Joffrin, Y.-S. Na, C.E. Kessel, Takahisa Ozeki, J. Garcia, V. Basiuk, Jin Myung Park, Holger St. John, R.V. Budny, Jean-Francois Artaud, and A. C. C. Sips
- Subjects
Physics ,Nuclear and High Energy Physics ,Steady state (electronics) ,Safety factor ,Tokamak ,Thermonuclear fusion ,Nuclear engineering ,Magnetic confinement fusion ,Fusion power ,Condensed Matter Physics ,ASTRA ,Bootstrap current ,law.invention ,law ,Atomic physics - Abstract
Integrated simulations are performed to establish a physics basis, in conjunction with present tokamak experiments, for the operating modes in the International Thermonuclear Experimental Reactor (ITER). Simulations of the hybrid mode are done using both fixed and free-boundary 1.5D transport evolution codes including CRONOS, ONETWO, TSC/TRANSP, TOPICS and ASTRA. The hybrid operating mode is simulated using the GLF23 and CDBM05 energy transport models. The injected powers are limited to the negative ion neutral beam, ion cyclotron and electron cyclotron heating systems. Several plasma parameters and source parameters are specified for the hybrid cases to provide a comparison of 1.5D core transport modelling assumptions, source physics modelling assumptions, as well as numerous peripheral physics modelling. Initial results indicate that very strict guidelines will need to be imposed on the application of GLF23, for example, to make useful comparisons. Some of the variations among the simulations are due to source models which vary widely among the codes used. In addition, there are a number of peripheral physics models that should be examined, some of which include fusion power production, bootstrap current, treatment of fast particles and treatment of impurities. The hybrid simulations project to fusion gains of 5.6–8.3, βN values of 2.1–2.6 and fusion powers ranging from 350 to 500 MW, under the assumptions outlined in section 3. Simulations of the steady state operating mode are done with the same 1.5D transport evolution codes cited above, except the ASTRA code. In these cases the energy transport model is more difficult to prescribe, so that energy confinement models will range from theory based to empirically based. The injected powers include the same sources as used for the hybrid with the possible addition of lower hybrid. The simulations of the steady state mode project to fusion gains of 3.5–7, βN values of 2.3–3.0 and fusion powers of 290 to 415 MW, under the assumptions described in section 4. These simulations will be presented and compared with particular focus on the resulting temperature profiles, source profiles and peripheral physics profiles. The steady state simulations are at an early stage and are focused on developing a range of safety factor profiles with 100% non-inductive current.
- Published
- 2007
32. Genetic parameters for measures of the efficiency of gain of boars and the genetic relationships with its component traits in Duroc pigs1
- Author
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Keiichi Suzuki, H. Kadowaki, T. Shibata, T. Oikawa, and M. A. Hoque
- Subjects
education.field_of_study ,Ecology ,Population ,General Medicine ,Biology ,Feed conversion ratio ,Genetic correlation ,Animal science ,Genetic gain ,Genetics ,Animal Science and Zoology ,Residual feed intake ,education ,Food Science - Abstract
Genetic parameters for the efficiency of gain traits on 380 boars and the genetic relationships with component traits were estimated in 1,642 pigs (380 boars, 868 gilts, and 394 barrows) in 7 generations of a Duroc population. The efficiency of gain traits included the feed conversion ratio (FCR) and residual feed intake (RFI) and their component traits, ADG, metabolic BW (MWT), and daily feed intake (FI). The RFI was calculated as the difference between the actual and expected FI. The expected FI was predicted by the nutritional requirement and by the residual of phenotypic (RFI(phe)) and genetic (RFI(gen)) regressions from the multivariate analysis for FI on MWT and ADG. The means for RFI(phe) and RFI(gen) were close to zero, and the mean for nutritional RFI was negative (-0.11 kg/d). The traits studied were moderately heritable (ranging from 0.27 to 0.53). The genetic and phenotypic correlations between ADG and FI were moderate to high, whereas the genetic correlation between MWT and FI was moderate, and the phenotypic correlation between them was low. The corresponding correlations between RFI(phe) and RFI(gen) were > 0.95, implying that they can be regarded as the same trait. The genetic and phenotypic correlations of FCR with measures of RFI were high but lower than unity. The RFI(phe) was phenotypically independent of its component traits, MWT (r(p) = 0.01) and ADG (r(p) = 0.03). The RFI(gen) was genetically independent of MWT (r(g) = -0.04), whereas there was a weak genetic relationship (r(g) = 0.15) between RFI(gen) and ADG. Residual FI was more heritable than FCR, and the genetic and phenotypic correlations of RFI(phe) and RFI(gen) with FI were positive and stronger than that of FCR with FI. These results provide evidence that RFI(phe) or RFI(gen) should be included in breeding programs for Duroc pigs to make genetic improvement in the efficiency of gain.
- Published
- 2007
33. Chapter 6: Steady state operation
- Author
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M. Murakami, M. R. Wade, C. Gormezano, B. Lloyd, C. K. Phillips, T. C. Luce, A. R. Polevoi, E. Barbato, V. Vdovin, C. E. Kessel, R. Bundy, E. Joffrin, T. Oikawa, D. Moreau, P. T. Bonoli, H. E. St John, N. Hayashi, T. A. Casper, D. Mazon, F. Imbeaux, A. Fukuyama, T. Suzuki, J. Hobirk, A. Isayama, A. Zvonkov, J. R. Ferron, A. C. C. Sips, R. Prater, X. Litaudon, A. Becoulet, and S. Ide
- Subjects
Nuclear and High Energy Physics ,Steady state (electronics) ,Tokamak ,Computer science ,Iter tokamak ,Magnetic confinement fusion ,Control engineering ,Fusion power ,Condensed Matter Physics ,Domain (software engineering) ,law.invention ,law ,Current (fluid) ,Actuator - Abstract
Significant progress has been made in the area of advanced modes of operation that are candidates for achieving steady state conditions in a fusion reactor. The corresponding parameters, domain of operation, scenarios and integration issues of advanced scenarios are discussed in this chapter. A review of the presently developed scenarios, including discussions on operational space, is given. Significant progress has been made in the domain of heating and current drive in recent years, especially in the domain of off-axis current drive, which is essential for the achievement of the required current profile. The actuators for heating and current drive that are necessary to produce and control the advanced tokamak discharges are discussed, including modelling and predictions for ITER. The specific control issues for steady state operation are discussed, including the already existing experimental results as well as the various strategies and needs (qψ profile control and temperature gradients). Achievable parameters for the ITER steady state and hybrid scenarios with foreseen heating and current drive systems are discussed using modelling including actuators, allowing an assessment of achievable current profiles. Finally, a summary is given in the last section including outstanding issues and recommendations for further research and development.
- Published
- 2007
34. Effect of Stress on Ferroelectricity of (Hf0.5Zr0.5)O2 Thin Films
- Author
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T. Oikawa, Hiroshi Uchida, H. Funakubo, T. Shiraishi, Takao Shimizu, and T. Yokouchi
- Subjects
Stress (mechanics) ,Materials science ,Thin film ,Composite material ,Ferroelectricity - Published
- 2015
35. Temporal and spatial variations of canopy temperature over a C3C4 mixture grassland
- Author
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T. Oikawa and S. Shimoda
- Subjects
Canopy ,Biomass (ecology) ,Stomatal conductance ,geography ,geography.geographical_feature_category ,Imperata ,biology ,Miscanthus sinensis ,Vegetation ,biology.organism_classification ,Grassland ,Agronomy ,Evapotranspiration ,Botany ,Environmental science ,Water Science and Technology - Abstract
This study discusses the photosynthetic pathway types involved in canopy temperature measurements on a mixed grassland consisting of C3 and C4 plants (dominant species in biomass were Solidago altissima (C3), Miscanthus sinensis (C4), and Imperata cylindrica (C4)). In the wet conditions immediately after the rainy season, the mean canopy temperature for S. altissima was the lowest among the dominant species, mainly due to its leaf conductance being twice as large as the other two species. Despite using the same C4 photosynthetic pathway, M. sinensis had a lower apparent canopy temperature than I. cylindrica due to a smaller proportion of sunlit elements in the field of view. In the dry conditions during late July, the mean canopy temperatures of the three dominant species were within 0·3 °C of one another. These results can be explained by poor water conditions for C3 species (S. altissima). The simultaneous survey of vegetation and thermal imaging can help clarify characteristics of C3 and C4 canopy temperature over complicated grassland. Copyright © 2006 John Wiley & Sons, Ltd.
- Published
- 2006
36. Prokinetic effect of a Kampo medicine, Hange-koboku-to (Banxia-houpo-tang), on patients with functional dyspepsia
- Author
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G. Ito, T. Oikawa, Toshihiko Hanawa, and H. Koyama
- Subjects
Adult ,Male ,medicine.medical_specialty ,Kampo ,medicine.medical_treatment ,Catechols ,Gastric motility ,Prokinetic agent ,Pharmaceutical Science ,Gastroenterology ,Lignans ,Statistics, Nonparametric ,Internal medicine ,Drug Discovery ,medicine ,Humans ,Limited evidence ,Dyspepsia ,Chromatography, High Pressure Liquid ,Ultrasonography ,Pharmacology ,Banxia Houpo Tang ,Gastric emptying ,business.industry ,Biphenyl Compounds ,Healthy subjects ,Middle Aged ,Gastric Emptying ,Complementary and alternative medicine ,Molecular Medicine ,Female ,Medicine, Kampo ,Fatty Alcohols ,Gastrointestinal function ,business ,Drugs, Chinese Herbal ,Phytotherapy - Abstract
Limited evidence is available as to whether Kampo medicine modifies gastrointestinal function in humans. We investigated the effect of a Kampo medicine, Hange-koboku-to (Banxia-houpo-tang, HKT), on patients with functional dyspepsia (FD) and on healthy volunteers with regard to gastric motility. The gastric emptying rate (GER) in FD patients was significantly lower than in the healthy subjects. GER in FD patients and in healthy volunteers showed a significant increase after 2 weeks of medication with HKT. Furthermore, gastrointestinal symptoms improved significantly in the FD patients after the administration of HKT. These results suggest that HKT improves delayed gastric emptying and acts as a prokinetic agent.
- Published
- 2005
37. Observation of the bootstrap current reduction at magnetic island in a neoclassical tearing mode plasma
- Author
-
T Oikawa, T Suzuki, A Isayama, N Hayashi, T Fujita, O Naito, T Tuda, G Kurita, and the JT-60 team
- Subjects
Physics ,Nuclear and High Energy Physics ,Safety factor ,Rational surface ,Condensed matter physics ,Magnetic confinement fusion ,Plasma ,Mechanics ,Condensed Matter Physics ,Bootstrap current ,Physics::Plasma Physics ,Tearing ,Magnetohydrodynamic drive ,Current density - Abstract
Evolution of the current density profile associated with magnetic island formation in a neoclassical tearing mode plasma is measured for the first time in JT-60U by using a motional Stark effect diagnostic. As the island grows, the current density profile turns flat at the radial region of the island and a hollow structure appears at the rational surface. As the island shrinks the deformed region becomes narrower and finally diminishes after the disappearance of the island. In a quiescent plasma without magnetohydrodynamic instabilities, on the other hand, no deformation is observed. The observed deformation in the current density profile associated with the tearing mode is reproduced in a time dependent transport simulation assuming the reduction of the bootstrap current in the radial region of the island. Comparison of the measurement with a calculated steady-state solution also shows that the reduction and recovery of the bootstrap current at the island explains the temporal behaviours of the current density and safety factor profiles. From the experimental observation and simulations, we reach the conclusion that the bootstrap current decreases within the island O-point.
- Published
- 2005
38. Energy loss for grassy ELMs and effects of plasma rotation on the ELM characteristics in JT-60U
- Author
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N Oyama, Y Sakamoto, A Isayama, M Takechi, P Gohil, L.L Lao, P.B Snyder, T Fujita, S Ide, Y Kamada, Y Miura, T Oikawa, T Suzuki, H Takenaga, K Toi, and the JT-60 Team
- Subjects
Nuclear and High Energy Physics ,Materials science ,Amplitude ,Toroid ,Pedestal ,Heat flux ,Divertor ,Magnetic confinement fusion ,Plasma ,Atomic physics ,Magnetohydrodynamics ,Condensed Matter Physics - Abstract
The energy loss for grassy edge localized modes (ELMs) has been studied to investigate the applicability of the grassy ELM regime to ITER. The grassy ELM regime is characterized by high frequency periodic collapses of 800–1500 Hz, which is ~15 times faster than that for type I ELMs. The divertor peak heat flux due to grassy ELMs is less than 10% of that for type I ELMs. This smaller heat flux is caused by a narrower radial extent of the collapse of the temperature pedestal. The different radial extent between type I ELMs and grassy ELMs agrees qualitatively with the different radial distribution of the eigenfunctions as determined from ideal MHD stability analysis. The dominant ELM energy loss for grassy ELMs appears to be caused by temperature reduction, and its ratio to the pedestal stored energy was 0.4–1%. This ratio is lower by a factor of about 10 than that for type I ELMs, which typically have between 2–10% fractional loss of the pedestal energy. A systematic study of the effects of counter (CTR) plasma rotation on the ELM characteristics has been performed using a combination of tangential and perpendicular neutral beam injections (NBIs) in JT-60U. In the high plasma triangularity (δ) regime, ELM characteristics (e.g. amplitude, frequency and type) can be changed from type I ELMs to high frequency grassy ELMs as the CTR plasma rotation is increased. On the other hand, in the low δ regime, complete ELM suppression (QH-mode) can be sustained for long periods up to 3.4 s (~18τE or energy confinement times), when the plasma position in terms of the clearance between the first wall and the plasma separatrix is optimized during the application of CTR-NBIs. In JT-60U, a transient QH phase was also observed during the CO-NBI phase with almost no net toroidal rotation at the plasma edge.
- Published
- 2005
39. Electron cyclotron heating assisted startup in JT-60U
- Author
-
Jt Team, S. Moriyama, Masami Seki, T. Oikawa, K. Kajiwara, T. Fujii, and Y. Ikeda
- Subjects
Nuclear and High Energy Physics ,Materials science ,Cyclotron ,Magnetic confinement fusion ,Atmospheric-pressure plasma ,Condensed Matter Physics ,law.invention ,Nuclear physics ,Townsend discharge ,law ,Electric field ,Torr ,Breakdown voltage ,Atomic physics ,Voltage - Abstract
Electron cyclotron heating (ECH)-assisted startup experiments have been performed in JT-60U. The breakdown loop voltage was successfully reduced from 25 to 4 V (=0.26 V m−1) by 200 kW ECH. This is lower than the 0.3 V m−1, which corresponds to the maximum electric field in ITER. Parameter scans of ECH power, prefill pressure, resonance position and polarization were carried out. The sensitivity of the breakdown to polarization and resonance position was observed. A prefilling gas pressure scan showed that the initial breakdown density increases with prefill pressure when it is is lower than 8 × 10−5 Torr. Higher harmonic ECH was also attempted. The second harmonic ECH-assisted startup was possible with higher ECH power injection. However, the third harmonic ECH-assisted startup was not successful.
- Published
- 2005
40. High-potential magnetic anisotropy of CoPtCr-SiO/sub 2/ perpendicular recording media
- Author
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Hajime Aoi, Hiroaki Muraoka, Satoshi Okamoto, Yoshihisa Nakamura, T. Oikawa, Y. Inaba, Takehito Shimatsu, Osamu Kitakami, and Hiroki Sato
- Subjects
Magnetic anisotropy ,Materials science ,Nuclear magnetic resonance ,Perpendicular magnetic anisotropy ,Platinum compounds ,Analytical chemistry ,Perpendicular recording ,Thermal stability ,Perpendicular media ,Electrical and Electronic Engineering ,Anisotropy ,High potential ,Electronic, Optical and Magnetic Materials - Abstract
The magnetic anisotropy of CoPtCr-SiO/sub 2/ perpendicular recording media, including higher energy terms, was studied as a function of film composition and seed layer materials. All series of CoPtCr films with various Cr content, deposited on Ru seed layers, show maximum values of total anisotropy K/sub u/ at 25-30 at%Pt. The maximum value for CoPt(Cr=0) films reaches /spl sim/15/spl times/10/sup 6/ erg/cm/sup 3/. The addition of SiO/sub 2/ to the CoPtCr films reduces the grain K/sub u/, however the grain K/sub u/ maintains a large value of 8/spl times/10/sup 6/ erg/cm/sup 3/ even when 10at%SiO/sub 2/ is added to (Co/sub 90/Cr/sub 10/)/sub 80/Pt/sub 20/, for instance, which indicates the high-potential thermal stability. Theoretical calculations for media designs of 400 Gbits/in/sup 2/ revealed that the ratio of the high-energy anisotropy term K/sub u2/ to K/sub u1/(K/sub u/=K/sub u1/+K/sub u2/) is required to be 0.2-0.35 to enhance the energy barrier for the remanent state, without a notable change in switching field. The films deposited on Ru seed layers were found to show negligibly small K/sub u2/ values, however, the values of K/sub u1/ and K/sub u2/ vary significantly with the seed layer material used. K/sub u1/ decreases almost linearly as the K/sub u2/ value increases. It is concluded that CoPtCr films have a sufficient potential in the values of K/sub u1/ and K/sub u2/ for high-density perpendicular media.
- Published
- 2005
41. Preliminary study of Hard/Soft-stacked Perpendicular Recording Media
- Author
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Osamu Kitakami, Y. Inaba, Hiroki Sato, T. Oikawa, Hajime Aoi, T. Shimatsu, Hiroaki Muraoka, and Yoshihisa Nakamura
- Subjects
Materials science ,Optics ,business.industry ,Perpendicular recording ,Electrical and Electronic Engineering ,Condensed Matter Physics ,business ,Instrumentation ,Electronic, Optical and Magnetic Materials - Published
- 2005
42. Ku2 term of magnetic anisotropy and microstructure of CoPtCr-SiO2 perpendicular recording media
- Author
-
K. Mitsuzuka, T. Oikawa, Yoshihisa Nakamura, Hiroaki Muraoka, Hajime Aoi, Osamu Kitakami, Satoshi Okamoto, Hiroki Sato, and Takehito Shimatsu
- Subjects
Magnetic anisotropy ,Materials science ,Condensed matter physics ,Distortion ,Perpendicular recording ,Electrical and Electronic Engineering ,Condensed Matter Physics ,Microstructure ,Magnetocrystalline anisotropy ,Anisotropy ,Instrumentation ,Electronic, Optical and Magnetic Materials ,Term (time) - Published
- 2005
43. The Effect of Sub-division (Two or Three Sub-populations) of a Population on Genetic Gain and Genetic Diversity
- Author
-
T. Oikawa, H. Matsui, and K. Sato
- Subjects
education.field_of_study ,Genetic diversity ,Population ,Biology ,Effective population size ,Genetic gain ,Evolutionary biology ,Inbreeding depression ,Additive genetic effects ,Animal Science and Zoology ,education ,Inbreeding ,Selection (genetic algorithm) ,Food Science - Abstract
Breeding efficiencies were compared among three population schemes: a single population, a population with two sub- populations and a population with three sub-populations. A simulation experiment of selection was carried out for 10 generations with 20 replications each by comparing average breeding values and inbreeding coefficients among the three population schemes. Phenotypes of three traits were generated with a model comprising 36 loci, each with additive genetic effects and residuals distributed normally. Among the three population schemes, the single population scheme was definitely superior to the other two with regards to selection response and inbreeding. The multiple sub-population scheme was, however, considered to be an alternative population scheme when the difference in economic weights of the traits was small among the sub-populations, assuming moderate inbreeding depression for traits and crossbreeding. The scheme with two sub-populations had a higher genetic value than that with three sub- populations; however, the genetic values of the schemes were comparable when maternal heterosis was taken into account. The choice of population schemes may depend on the cost-sharing policy between the breeding population and the commercial population rather than just the breeding efficiency. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 6 : 767-771)
- Published
- 2005
44. Evapotranspiration from a wet temperate grassland and its sensitivity to microenvironmental variables
- Author
-
G. Lee, Shenggong Li, T. Oikawa, Chun-Ta Lai, T. Yokoyama, Atsushi Higuchi, and S. Shimoda
- Subjects
Canopy ,Hydrology ,Vapour Pressure Deficit ,Lysimeter ,Evapotranspiration ,Eddy covariance ,Environmental science ,Leaf area index ,Sensible heat ,Energy budget ,Water Science and Technology - Abstract
The eddy covariance and energy balance method was employed to determine evapotranspiration (LE) over a wet temperate C3–C4 co-existing grassland in Japan. After sensible heat flux (H) was estimated via the eddy covariance technique, LE was calculated as the residual of the energy budget with calibration against the direct measurements of LE by a lysimeter. Daily mean LE varied from 0·8 to 10·5 MJ d−1, with a peak at 16·5 MJ d−1 in late July to early August. Day-to-day and seasonal variability in LE was affected appreciably by net radiation (Rn), atmospheric vapour pressure deficit (VPD), canopy surface conductance (gc) and leaf area index (LAI). Before the canopy closure, LE responded to LAI in a linear manner. However, LE decreased with increasing LAI later in summer. Daytime variation in the decoupling coefficient (Ω) demonstrates that the canopy decoupled from the atmosphere in the morning and LE was primarily driven by the available energy, while in the afternoon the canopy partially coupled to the atmosphere so that LE was sensitive to VPD and gc. Throughout the whole measurement period, Ω was generally larger than 0·5, suggesting that the available energy contributes more to LE than VPD. Copyright © 2004 John Wiley & Sons, Ltd.
- Published
- 2005
45. Fast dynamics of type I ELMs and transport of the ELM pulse in JT-60U
- Author
-
N Oyama, N Asakura, A.V Chankin, T Oikawa, M Sugihara, H Takenaga, K Itami, Y Miura, Y Kamada, K Shinohara, and the JT-60 Team
- Subjects
Nuclear and High Energy Physics ,Materials science ,Physics::Instrumentation and Detectors ,business.industry ,Divertor ,Phase (waves) ,Magnetic confinement fusion ,Plasma ,Collisionality ,Condensed Matter Physics ,Pedestal ,Optics ,Heat flux ,Physics::Plasma Physics ,Plasma diagnostics ,Atomic physics ,business - Abstract
Simultaneous fast ELM measurements using a reflectometer, interferometers, Dα intensity and a magnetic probe reveal the detailed characteristics of type I ELMs. From the phase signal of the reflectometer indicating the radial movement of the cut-off layer, four different phases in the ELM event, i.e. a precursor phase, collapse phase, recovery phase and a relaxation phase, were observed. In the collapse phase, the radial extent of the collapse of the density pedestal reached up to twice the pedestal width. A fast drop of the horizontal interferometer signal was observed, while the vertical interferometer on the high-field side edge plasma only exhibited a small and delayed reduction. These features of the plasma response due to ELMs might indicate a non-uniform collapse of the density pedestal in the poloidal direction, localized near the low-field side (LFS) midplane. Expelled particles from the LFS midplane were measured by using scrape-off layer Mach probes, and the heat flux to the divertor target was measured using a fast infrared TV camera. The time constant of the peak heat load was comparable to that of the enhancement of the plasma flow towards the divertor target. The normalized ELM energy loss by pedestal stored energy in JT-60U was found to be less than 10% of the pedestal stored energy. It shows weak dependence on the pedestal parameters such as electron collisionality, parallel ion loss time and the ratio of the pedestal density to the Greenwald density limit.
- Published
- 2004
46. Development of plasma stored energy feedback control and its application to high performance discharges on JT-60U
- Author
-
Y. Kawamata, T. Oikawa, K. Kurihara, T. Fukuda, K. Tsuchiya, Takaaki Fujita, and Yuzuru Neyatani
- Subjects
Tokamak ,Materials science ,Plasma parameters ,Mechanical Engineering ,Mechanics ,Plasma ,Fusion power ,Neutral beam injection ,law.invention ,Nuclear magnetic resonance ,Nuclear Energy and Engineering ,Physics::Plasma Physics ,law ,Beta (plasma physics) ,Physics::Space Physics ,Waveform ,General Materials Science ,Magnetohydrodynamics ,Civil and Structural Engineering - Abstract
The real-time feedback control of the plasma stored energy has been developed for control of the plasma MHD stability in the JT-60U tokamak. The plasma stored energy can be detected with high accuracy in real-time by a function parameterization method for various plasmas available in JT-60U, such as Ohmic plasmas, the L-mode, the H-mode, the high poloidal beta mode and the reversed shear mode over a wide range of the plasma parameters. By manipulating the neutral beam injection power, the plasma stored energy has been successfully controlled along the preprogrammed reference waveform. Especially in the reversed shear mode, this feedback control scheme has improved the reproducibility of the formation of the internal transport barrier, and MHD activities could be suppressed keeping the normalized beta in a stable region. A DT equivalent fusion amplification gain of 0.5 was sustained for 0.8 s in a reversed shear plasma by employing this feedback control scheme.
- Published
- 2004
47. Analytical Electron Microscopy for Materials Science
- Author
-
DAISUKE Shindo, T. Oikawa, DAISUKE Shindo, and T. Oikawa
- Subjects
- Materials--Microscopy, Electron microscopy
- Abstract
Analytical electron microscopy is one of the most powerful tools today for characterization of the advanced materials that support the nanotechnology of the twenty-first century. In this book the authors clearly explain both the basic principles and the latest developments in the field. In addition to a fundamental description of the inelastic scattering process, an explanation of the constituent hardware is provided. Standard quantitative analytical techniques employing electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy are also explained, along with elemental mapping techniques. Included are sections on convergent beam electron diffraction and electron holography utilizing the field emission gun. With generous use of illustrations and experimental data, this book is a valuable resource for anyone concerned with materials characterization, electron microscopy, materials science, crystallography, and instrumentation.
- Published
- 2013
48. Achievement of high fusion triple product, steady-state sustainment and real-time NTM stabilization in high- pELMy H-mode discharges in JT-60U
- Author
-
A Isayama, Y Kamada, N Hayashi, T Suzuki, T Oikawa, T Fujita, T Fukuda, S Ide, H Takenaga, K Ushigusa, T Ozeki, Y Ikeda, N Umeda, H Yamada, M Isobe, Y Narushima, K Ikeda, S Sakakibara, K Yamazaki, K Nagasaki, and the JT-60 Team
- Subjects
Physics ,Nuclear and High Energy Physics ,Steady state ,Record value ,Cyclotron ,Magnetic confinement fusion ,Plasma ,Electron ,Condensed Matter Physics ,law.invention ,Triple product ,law ,Beta (plasma physics) ,Atomic physics - Abstract
This paper reports results on the progress in steady-state high-βp ELMy H-mode discharges in JT-60U. A fusion triple product, nD(0)τETi(0), of 3.1 × 1020 m−3 s keV under full non-inductive current drive has been achieved at Ip = 1.8 MA, which extends the record value of the fusion triple product under full non-inductive current drive by 50%. A high-beta plasma with βN ~ 2.7 has been sustained for 7.4 s (~60τE), with the duration determined only by the facility limits, such as the capability of the poloidal field coils and the upper limit on the duration of injection of neutral beams. Destabilization of neoclassical tearing modes (NTMs) has been avoided with good reproducibility by tailoring the current and pressure profiles. On the other hand, a real-time NTM stabilization system has been developed where detection of the centre of the magnetic island and optimization of the injection angle of the electron cyclotron wave are done in real time. By applying this system, a 3/2 NTM has been completely stabilized in a high-beta region (βp ~ 1.2, βN ~ 1.5), and the beta value and confinement enhancement factor have been improved by the stabilization.
- Published
- 2003
49. Asymmetry of collapse of density pedestal by type I ELM in JT-60U
- Author
-
Yutaka Kamada, Nobuyuki Asakura, S. Takeji, Hidenobu Takenaga, Y.M. Miura, K. Shinohara, A. V. Chankin, Naoyuki Oyama, and T. Oikawa
- Subjects
Physics ,Nuclear and High Energy Physics ,Density gradient ,business.industry ,media_common.quotation_subject ,Magnetic confinement fusion ,Plasma ,Condensed Matter Physics ,Asymmetry ,Intensity (physics) ,Interferometry ,Pedestal ,Optics ,Physics::Plasma Physics ,Plasma diagnostics ,Atomic physics ,business ,media_common - Abstract
The edge plasma density at the high-field side (HFS) and low-field side (LFS) was measured using a FIR interferometer and an O-mode reflectometer simultaneously in order to study the asymmetry of collapse of the density pedestal by type I ELM. From fast time series analysis using the same digitizer system for the reflectometer, Dα intensity, interferometer and magnetic probe, experimental evidence for poloidal asymmetry of the collapse was clearly observed in JT-60U ELMy H-mode discharges for the first time. The collapse of the pedestal density is manifested as a fast inward displacement of the cutoff layer at the LFS, the increase of Dα intensity and large magnetic oscillations. No immediate response, however, was observed in the line-integrated density at the HFS of the plasma (FIR-U1). Instead, the signal showed a small reduction after a time delay of about L∥/Cs, which was attributed to the parallel flow from the inside to outside in order to fill the density gap as a result of localized particle expulsion from the LFS. Furthermore, no density increase in the HFS scrape-off layer (SOL) was observed during the horizontal plasma sweep experiments corresponding to particles expelled from the HFS midplane to the SOL directly, at the onset of density collapse and before the increase of Dα intensity. Together, these results indicate that the collapse of the density pedestal during type I ELMs is localized at the LFS midplane.
- Published
- 2003
50. CoPtCr-SiO/sub 2/ granular media for high-density perpendicular recording
- Author
-
K. Enomoto, H. Uwazumi, Y. Sakai, S. Watanabe, T. Oikawa, and S. Takenoiri
- Subjects
Nuclear magnetic resonance ,Materials science ,Ferromagnetism ,Remanence ,Analytical chemistry ,Perpendicular recording ,Grain boundary ,Electrical and Electronic Engineering ,Coercivity ,Magnetic hysteresis ,Microstructure ,Grain size ,Electronic, Optical and Magnetic Materials - Abstract
SiO/sub 2/ added CoPtCr magnetic layers are employed for perpendicular recording media. The microstructure, magnetic properties, and recording performance of these media are discussed. Very fine grains with size of less than 7 nm, surrounded by grain boundaries mainly consisting of silicon oxide, are realized. The addition of SiO/sub 2/ to CoPtCr is very effective in enhancing the well-isolated fine grain structure without disturbing the epitaxial growth of the CoPtCr grains on the Ru underlayer. The media show a large perpendicular anisotropy K/sub u/ of /spl sim/4 /spl times/ 10/sup 6/ erg/cm/sup 3/ and a K/sub u/V/kT value of more than 80, even at a CoPtCr-SiO/sub 2/ thickness of 12 nm, resulting in a high coercivity H/sub c/ (/spl sim/4 kOe) and high squareness M/sub r//M/sub s/ of /spl sim/0.96. The CoPtCr-SiO/sub 2/ medium shows excellent signal-to-medium-noise ratio performance together with high thermal stability at very thin thickness, indicating great potential for high-density perpendicular recording media.
- Published
- 2003
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