Progress in R&D of coated conductor in M-PACC project

Izumi, T.,Ibi, A.,Nakaoka, K.,Taneda, T.,Yoshida, T.,Takagi, Y.,Nakamura, T.,Machi, T.,Katayama, K.,Sakai, N.,Yoshizumi, M.,Koizumi, T.,Kimura, K.,Kato, T.,Kiss, T.,Shiohara, Y. The Korea Institute of Applied Superconductivity a 2014 한국초전도저온공학회논문지 Vol.16 No.2

The five-year national project in Japan for R&D of coated conductors and applications, named as the Materials and Power Applications of Coated Conductors (M-PACC) project, was finished at the end of FY2013. The project consists of four sub-themes as cable, transformer, SMES and coated conductors. In the theme of coated conductors, the fabrication process had been developed to satisfy the requirements from the applications such as in-field $I_c$ performance, low AC loss in the long tapes etc. Through the project, the remarkable progress was achieved as follows; a high in-field minimum $I_c$ value over 54A/cm-width under 3T at 77K was realized in a 200m long EuBCO tape with artificial pinning centers of $BaHfO_3$ by the pulsed laser deposition (PLD) technique on the IBAD template. On the other hand, the AC loss reduction was confirmed in the tapes fabricated by both PLD and the metal organic deposition (MOD) techniques by scribing 100m tapes into 10-filamments. Additionally, the mechanism of the delamination phenomenon was systematically investigated and the strength was improved by eliminating the origins of the weak points in the films. Through the development, all targeted goals were accomplished and the several results were appreciated as a world champion data.

Progress in R&D of coated conductor in M-PACC project

T. Izumi,A. Ibi,K. Nakaoka,T. Taneda,T. Yoshida,Y. Takagi,T. Nakamura,T. Machi,K. Katayama,N. Sakai,M. Yoshizumi,T. Koizumi,K. Kimura,T. Kato,T. Kiss,Y. Shiohara 한국초전도저온학회 (구 한국초전도저온공학회) 2014 한국초전도저온공학회논문지 Vol.16 No.2

One-Anastomosis and Roux-en-Y Gastric Bypass Promote Similar Weight Loss, Patient Satisfaction, Quality of Life, Inflammation Grade, and Cellular Damage in the Esophagus and Gastric Pouch in a Short-term Follow-up

Rafael C. Katayama,Carlos H. Arasaki,Fernando A.M. Herbella,Ricardo A. Neto,Gaspar de Jesus Lopes Filho 대한비만학회 2021 The Korean journal of obesity Vol.30 No.4

Background: One-anastomosis gastric bypass (OAGB) is a simpler procedure than Roux-en-Y gastric bypass (RYGB); however, biliary reflux can occur and impair outcomes. This study aimed to compare outcomes of OAGB and RYGB. Methods: Twenty patients with morbid obesity were randomized prospectively into two groups: OAGB (n=10) or RYGB (n=10). Quality of life (36-item short-form health survey [SF-36]), satisfaction (Visick scale), and body mass index (BMI) were evaluated before and 6 months after the operation. All patients underwent esophagogastroduodenoscopy with gastric and esophageal mucosal biopsies at 3 and 6 months after their operation. Results: The study found no significant difference in BMI before surgery (OAGB, 43.2 kg/m2; RYGB, 43.1 kg/m2; P=0.90) or at 6 months postoperative (OAGB, 32.1 kg/m2; RYGB, 31.8 kg/m2; P=0.91). There was no significant difference in improvement of quality of life (four SF-36 domains) or satisfaction (P=0.08) between groups at 6 months. There was no statistical difference between gastric (P=0.10) and esophageal (P=0.76) inflammation grade at three or 6 months between the two groups. Conclusion: OAGB and RYGB are equally effective in terms of weight loss, patient satisfaction, and quality of life improvement at 6 months after the procedures. Inflammation grade and cellular damage in the gastric pouch and in the esophagus were similar.

PECVD에 의해 작성된 탄소계 박막의 전계전자방출특성에 대한 증착온도 의존성에 관한 연구

류정탁,백양규,이형주,M. Katayama,K. Oura 한국진공학회 2003 Applied Science and Convergence Technology Vol.12 No.1

본 논문에서는 혼합가스 없이 메탄가스만을 사용하여 RF PECVD 방법으로 성장시킨 a-C 박막의 전계전자방출특성을 조사하였다. 또한 본 논문은 박막의 표면형태와 결정들의 결합구조가 어떻게 전계전자방출에 영향을 미치는가에 관하여 보고된다, a-C 박막의 전계전자방출특성은 증착온도에 크게 의존함이 확인되었다. 실온에서 성장된 카본박막의 문턱전압은 20 V/$\mu\textrm{m}$이었다. 그러나 증착온도가 $500^{\circ}C$로부터 $600^{\circ}C$로 증가함에 따라 문턱전압은 17 V/$\mu\textrm{m}$에서 10 V/$\mu\textrm{m}$으로 감소하였으며 $800^{\circ}C$에서는 문턱전압이 B V/$\mu\textrm{m}$로 크게 개선되었다. 박막의 표면형태, 구조적인 특징과 전계전자방출특성의 관계를 조사하기 위해서 라만 스펙트럼과 주사형전자현미경 (scanning electron microscopy : SEM)을 사용하였다. 박막의 물리적, 화학적, 특성은 증착온도에 매우 의존하며 이들 특성들은 전계전자방출특성에 큰 영향을 미친다는 사실을 발견했다. Using RF plasma enhanced chemical vapor deposition, amorphous carbon films were grown in pure methane plasma. Field electron emission of these films were examined at a function of deposition temperature. It was found that the electron emission current of the sample prepared at deposition temperature above $600^{\circ}C$ was considerably improved. The film grown at deposition temperature of $800^{\circ}C$ had the best threshold field of 8 V/$\mu\textrm{m}$ in this experiment. According to the results of Raman spectroscopy. growth of graphite crystallites was promoted with higher deposition temperatures. Moreover the surface morphology was abruptly changed at deposition temperature above $600^{\circ}C$. We discuss the field electron emission characteristics of amorphous carbon films with regard to the structural feature and surface morphology.

나노입자가 내장된 기능성 박막의 제작과 전자소자 특성

Ryu, Jeong-Tak,Ikuno, T,Honda, S.,Katayama, M.,Oura, K. 한국산업정보학회 2006 한국산업정보학회논문지 Vol.11 No.4

본 논문에서는 DC 플라즈마와 금속유기물을 사용하여 CNF의 저온 합성에 성공하였다. 합성된 CNTs는 기판의 위치에 따라 매우 다른 특성 차이가 보였다. CNT는 일반적으로 직경 100 nm, 길이 $10{\mu}m$의 특성을 가진다. CNT의 형태적 특성들은 전계전자방출특성에 큰 영향을 준다는 사실을 본 연구를 통해 알 수 있었다. 따라서 CNF의 합성에 의한 CNF 구조적 특성은 전자소자응용면에서 매우 중요한 역할을 한다. Carbon nanofibers have synthesized a low temperature using DC Ar plasma and Fe-Phthalocyanine, and a characteristic difference of the synthesized CNF according to the location of the substrate was investigated. The carbon nanofibers had about 100nm diameter and up to $10{\mu}m$ length. These were grown in random orientation. There are two shapes in the CNFs, screw and straight line shapes. Furthermore, we found the selective growth of nanofibers on the scratched substrates. The density of CNFs synthesized on the position (a) were higher than that synthesized on the position (b) [See the Fig. 2]. Also, the length of CNFs was different. In the shape, CNFs with screw and straight line shape were synthesized in the position (a), but. only CNFs with straight line shape were synthesized in the position (b). The difference have an important effect on the field emission characteristics.

질소 플라즈마처리에 의한 a-C 박막의 전계방출특성 변화에 관한 연구

Ryu, Jeong-Tak,Lee, K.Y.,Honda, S.,Katayama M.,Oura, K. 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.12

Amorphous carbon (a-C) films have been deposited on Si(100) substrate using RF magnetron system in order to investigate the electron field emission properties. The a-C films were treated by $N_2$ gas plasma at room temperature. Surface morphologices and structural properties of the a-C films before and after $N_2$ plasma treatment were observed by scanning electron microscopy and Raman spectroscope, respectively. Structural properties and surface morphology of the a-C films were changed by $N_2$ plasma treatment. The emission properties can be improved by the plasma treatment according to the contents of nitrogen on the a-C films which is varied by plasma treatment time. Before the plasma treatment, the a-C films are found to have a threshold field of 14 V/$\mu$m, but the a-C film treated by $N_2$ plasma for 30 min exhibit threshold field as low as 6.5 V/$\mu$m.

Microbial Transglutaminase Improves the Property of Meat Protein and Sausage Texture Manufactured with Low-quality Pork Loins

Katayama, K.,Chin, K.B.,Yoshihara, S.,Muguruma, M. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.1

Microbial transglutaminase (MTGase) was investigated to determine whether it was an effective binding agent for the processing of low-quality pork loins. MTGase especially promoted the coagulation of myosin heavy chain (MHC). However, the effect of MTGase on MHC from low-quality meat was less than that from the normal meat when the reaction time was not enough. The breaking strength of the heat-induced gel made of myosin B from low-quality meat with MTGase was lower than that of normal meat. Sausage made with low-quality meat with MTGase did not exhibit improved hardness, as compared to that made with normal meat. Results of this study indicated that use of low-quality meat in the manufacture of sausage was feasible to get textural property equal to that of normal meat sausage, when a half or more of the raw material was normal meat and MTGase was used in the sausage.

Angiotensin I-converting Enzyme Inhibitory Activities of Porcine Skeletal Muscle Proteins Following Enzyme Digestion

Katayama, K.,Fuchu, H.,Sakata, A.,Kawahara, S.,Yamauchi, K.,Kawamura, Y.,Muguruma, M. Asian Australasian Association of Animal Productio 2003 Animal Bioscience Vol.16 No.3

Inhibitory activities against angiotensin I-converting enzyme (ACE) of enzymatic hydrolysates of porcine skeletal muscle proteins were investigated. Myosin B, myosin, actin, tropomyosin, troponin and water-soluble proteins extracted from pork loin were digested by eight kinds of proteases, including pepsin, $\alpha$-chymotrypsin, and trypsin. After digestion, hydrolysates produced from all proteins showed ACE inhibitory activities, and the peptic hydrolysate showed the strongest activity. In the case of myosin B, the molar concentration of peptic hydrolysate required to inhibit 50% of the activity increased gradually as digestion proceeded. The hydrolysates produced by sequential digestion with pepsin and $\alpha$-chymotrypsin, pepsin and trypsin or pepsin and pancreatin showed weaker activities than those by pepsin alone, suggesting that ACE inhibitory peptides from peptic digestion might lose their active sequences after digestion by the second protease. However, the hydrolysates produced by sequential digestion showed stronger activities than those by $\alpha$-chymotrypsin, trypsin or pancreatin alone. These results suggested that the hydrolysates of porcine meat were able to show ACE inhibitory activity, even if they were digested in vivo, and that pork might be a useful source of physiologically functional factors.

Computational Nano-Materials Design for II-VI Compound Semiconductor-Based Spintronics

H. Katayama-Yoshida,K. Sato,T. Fukushima,M. Toyoda,H. Kizaki,Van An Dinh,P. H. Dederichs 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

Based on the state-of-the-art ab-initio electronic structure calculation by using the Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA) method with the local density approximation (LDA) and self-interaction corrected LDA (SIC-LDA) to go beyond the LDA, we propose a unified physical picture of 3d transition-metal-doped dilute-magnetic-semiconductors (DMS) in II-VI compound semiconductors, such as ZnO, ZnS, ZnSe and ZnTe. Zener's double-exchange interaction and super-exchange interaction mechanisms are competing in the magnetism of II-VI DMS. In a homogeneous system, the electronic structure calculated by using the SIC-LDA and the Curie temperature (TC) in a Monte Carlo simulation with the LDA is in good agreement with the experimental data of photoemission spectroscopy and the experimental value of TC. In a inhomogeneous system, we propose the three-dimensional Dairiseki phase and the one-dimensional Konbu phasecaused by spinodal nano-decomposition. These are responsible for the high-TC (or TB) phases in the DMS. We design the growth position and control the shape of nano-magnets by using self-organization. Based on the state-of-the-art ab-initio electronic structure calculation by using the Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA) method with the local density approximation (LDA) and self-interaction corrected LDA (SIC-LDA) to go beyond the LDA, we propose a unified physical picture of 3d transition-metal-doped dilute-magnetic-semiconductors (DMS) in II-VI compound semiconductors, such as ZnO, ZnS, ZnSe and ZnTe. Zener's double-exchange interaction and super-exchange interaction mechanisms are competing in the magnetism of II-VI DMS. In a homogeneous system, the electronic structure calculated by using the SIC-LDA and the Curie temperature (TC) in a Monte Carlo simulation with the LDA is in good agreement with the experimental data of photoemission spectroscopy and the experimental value of TC. In a inhomogeneous system, we propose the three-dimensional Dairiseki phase and the one-dimensional Konbu phasecaused by spinodal nano-decomposition. These are responsible for the high-TC (or TB) phases in the DMS. We design the growth position and control the shape of nano-magnets by using self-organization.

Study on Modular Multi-Level DC-DC Converter with Cell Voltage Balancing and Fast Output Response Using Sub Commutation Circuits

H. Obara,M. Katayama,A. Kawamura,J. Xu,N. Shimosato,S. Inoue 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

DC power supplies for a battery testing are becoming significantly important for developments of electrical vehicles (EVs), mobile devices, and renewable energy generations. In the recent decade, modular multi-level converters (MMC) have been actively studied and started to use on some practical applications such as high- or mediumvoltage DC-AC or AC-DC power converters. However, the widely used MMC topology has a significant issue to extend to a DC-DC converter, because it cannot achieve capacitor voltage balancing of each cell unlike the case of the DC-AC and AC-DC conversions. Therefore, most of the MMC-based DC-DC converters are realized by combining the DC-AC converter, isolation transformer or inductor, and AC-DC converter. In this study, the DC-DC operation in the MMC and its problem are analyzed and clarified. This paper proposes a circuit topology and control method of the MMCbased DC-DC converter with cell voltage balancing and fast dynamic response while the DC-AC and AC-DC converters are not used. Simulation results verify the validity of the capacitor voltage balancing control. Finally, an experimental result in a prototype converter with 6-cells using SiCMOSFETs shows the performances of the voltage balancing control and fast dynamic response.