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Superconducting magnets in fusion reactors are subjected to a huge electromagnetic force of >100 MN/m. The magnets have to be sustained with a strong-body structure to avoid high stress and deformation. The total weight of the magnet system in the fusion reactor is estimated to be more than 20,000 tons. We applied topology optimization technique to the magnet support structure to reduce the weight of fusion reactors. Compared with the conventional design, we achieved a weight reduction of >25%. Static and seismic analyses were carried out to validate the soundness of the topology-optimized design. Consequently, the stress against the electromagnetic force in the structure was within the permissible range. It was discovered that using seismic isolation structure can adequately prevent the damage to the magnet system even when directly subjected to a massive earthquake.

Three-phase dual active bridge converters (DAB3) are a widely used topology in battery charging applications thanks to their numerous advantages, such as bidirectional power flow, galvanic isolation, low output current ripple, and inherent soft-switching. In such applications, three single-phase transformers are commonly employed as the AC-link to simplify manufacturing and reduce costs. These transformers’ leakage inductance can be utilized instead of the external leakage inductance to achieve high power density. However, the assumption of uniformity in these inductances is not always accurate as they can vary significantly during fabrication. This study presents a comprehensive analysis of the impact of transformer leakage inductance variation, which can deviate by up to 24% from the desired value. The effects of this variation are investigated from different perspectives, including power transfer, soft-switching range, root-mean-square (RMS) current, and the temperature rise of the transformer winding. Although the power transfer and total copper loss of transformers are changed insignificantly even under highly mismatched leakage inductance, the currents and thermal distribution among phases are considerably impacted. Based on statistical probability, a maximum leakage inductance variation threshold of 10–15% compared to the desired value is recommended to ensure the maximum acceptable temperature rise among phases. Experimental results are presented to validate the analysis.

Electrochemical reduction processes of oxides in molten salt have been proposed as the carbon free technology in order to achieve carbon neutral. The anodic behavior of La1−xSrxFeO3−δ as an oxygen-evolution anode in LiCl−KCl at 723 K is investigated. Data suggests that at 723 K, the electrical conductivity of La1−xSrxFeO3−δ tends to increase as the extent of Sr doping. The anodic reactions of La1−xSrxFeO3−δ electrodes are characterized by electrochemical measurements in LiCl−KCl + Li2O at 723 K. Based on the cyclic voltammograms of the La0.7Sr0.3FeO3−δ electrode, oxygen evolution has proceeded between 2.7 V and 3.6 V. The potential of La0.7Sr0.3FeO3−δ electrode during galvanostatic electrolysis has conducted at 39 mA cm-2 for 15 h has remained stable at 2.8 V, indicating that the stable evolution of oxygen gas is monitored. The corrosion rate is estimated to have the low value of 8.6 × 10−4 g cm−2 h−1. Electrode surface data collect after electrolysis indicate that La0.7Sr0.3FeO3−δ electrode has excellent chemical and physical stability in LiCl−KCl at 723 K. Evidence thus indicates that La0.7Sr0.3FeO3−δ electrode is a promising candidate material as inert anodes for oxides decomposition. As one of application of the La0.7Sr0.3FeO3−δ electrode, the electrolysis reduction of CO2 was also successfully achieved.

Background/Aim: Invariant natural killer T (iNKT) cells are involved in the initiation and resolution of inflammatory responses. We previously reported that activated iNKT cells facilitate liver repair after hepatic ischemia reperfusion (I/R) injury by accelerating macrophage polarization during the early phase of hepatic I/R injury. Upon activation with α-galactosylceramide (α-GalCer), iNKT cell numbers transiently decrease before increasing within 72 h of stimulation. In the present study, we examined the role of expanded hepatic iNKT cells in the late phase of hepatic I/R injury. Materials and Methods: iNKT cells were activated by intraperitoneal injection of α-GalCer in male C57/BL6 mice at the induction of hepatic ischemia followed by reperfusion. Results: Numbers of activated hepatic iNKT cells immediately diminished after hepatic I/R and reached minimal levels at 24 h and 48 h post-reperfusion. Numbers of hepatic iNKT cells then increased at 72 h and 96 h post-reperfusion to levels approximately 2-fold higher than in mice that underwent a sham operation. Liver repair as demonstrated by decreased necrotic area and increased expression of proliferating cell nuclear antigen (PCNA) was enhanced in α-GalCer-treated mice at 96 h post-reperfusion. Interleukin (IL)-13 production by proliferating iNKT cells was observed at 96 h post-reperfusion, which was associated with enhanced liver repair and increased numbers of reparative macrophages. Conclusion: Repopulation of hepatic iNKT cells promotes liver repair by stimulating macrophage phenotype switching in the late phase of hepatic I/R injury.

This study proposes an estimation method of flux density in high‐frequency transformers of three‐phase dual‐active‐bridge transformers. The steady‐state analysis shows that the flux in the converter is different in Buck and Boost modes and depending on load and voltage gain condition. From that, a closed‐form formula is proposed to estimate the flux swing in the core. Unlike the conventional estimation technique, the proposed one represents the flux as a function of input and output voltages and the phase shift value. Finite element analysis confirms that the proposed formula can predict the flux with less than 4% error. The proposed formula can also help to improve the prediction of temperature profile of the transformers with a high accuracy of less than 1 degree Celsius in the mid‐ to high‐power range as validated in experiments. The proposed flux estimation method can be used in designing the converter or in predicting the converter behaviour under critical conditions such as load changing or starting, and so forth, to help protect the transformers from saturation or DC bias.

電析より絶縁体上への絶縁体の被覆は困難であるが、実現すれば機械・電子産業等で応用範囲の拡大が期待できる。著者らはTiO_2と金属チタンを添加・浸漬させたLiF-KF浴中でAl_2O_3上に電析によって酸化チタンを形成する新たな方法を提案する。電析した酸化チタンは、ニッケル線/溶融塩/Al_2O_3の三相界面から放射状に成長することが判明した。本研究では酸化チタンの結晶成長に関する知見を与え、絶縁体への酸化チタンのメッキ方法の提案をする。, Electrochemical deposition of an insulator on any insulator is considered to be difficult. If such deposition can be accomplished, it would have a variety of practical applications in both mechanical and electronic industries. We are thus proposing a new method for electrochemical deposition of titanium oxide on alumina substrate in LiF-KF with the addition of TiO_2 and metal titanium. Titanium oxide deposition grew from the three-phase interface of nickel wire, molten salt and alumina substrate in a radial pattern. These results provide new insight into the growth process of titanium oxide crystals and possibly a new comprehensive plating procedure for titanium oxide on insulator substrates., 論文名・抄録(日本語)・抄録(英語)の_2と_3は下付き文字

The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS).The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group.After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested.Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6 ± 1.4 kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30 minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20-minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross-clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non-working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure-volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End-systolic elastance (P = .02) and pulmonary arterial elastance significantly increased (P = .03), but the ratio of arterial elastance to end-systolic elastance was preserved (P = .91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension.

Macrophage plasticity is essential for liver wound healing; however, the mechanisms underlying macrophage phenotype switching are largely unknown. Dendritic cells (DCs) are critical initiators of innate immune responses; as such, they orchestrate inflammation following hepatic injury. Here, we subjected EP3-deficient (Ptger3-/- ) and wild-type (WT) mice to hepatic ischemia-reperfusion (I/R) and demonstrate that signaling via the prostaglandin E (PGE) receptor EP3 in DCs regulates macrophage plasticity during liver repair. Compared with WT mice, Ptger3-/- mice showed delayed liver repair accompanied by reduced expression of hepatic growth factors and accumulation of Ly6Clow reparative macrophages and monocyte-derived DCs (moDCs). MoDCs were recruited to the boundary between damaged and undamaged liver tissue in an EP3-dependent manner. Adoptive transfer of moDCs from Ptger3-/- mice resulted in impaired repair, along with increased numbers of Ly6Chigh inflammatory macrophages. Bone marrow macrophages (BMMs) up-regulated expression of genes related to a reparative macrophage phenotype when co-cultured with moDCs; this phenomenon was dependent on EP3 signaling. In the presence of an EP3 agonist, interleukin (IL)-13 derived from moDCs drove BMMs to increase expression of genes characteristic of a reparative macrophage phenotype. The results suggest that EP3 signaling in moDCs facilitates liver repair by inducing IL-13-mediated switching of macrophage phenotype from pro-inflammatory to pro-reparative.

We report the case of a 16-year-old boy in whom we successfully repaired a distal aortic arch aneurysm associated with pseudocoarctation using double aortic cannulation and antegrade selective cerebral perfusion through the L-incision approach. This approach provided excellent exposure from the ascending aorta to the descending aorta, which enabled total body perfusion. We avoided cardiac arrest and hypothermic circulatory arrest during the surgery. The L-incision approach could be a better alternative for aortic arch surgery in adolescents.

The difference between Ti(III) and Ti(IV) significantly influences the electrodeposition process of Ti in fluoride melt. In this study, we investigated the melt structure of LiF-KF with the addition of TiO2 for Ti(IV) and with the addition of both TiO2 and bulk titanium (Ti0) for Ti(III) by combining high-temperature Raman spectroscopic technique and density functional theory calculations. The Raman spectra were characterized by three kinds of coordination structures: polyatomic ion-like structures such as TiO2F2 2−, polyatomic cation-coordinated ion-like structures such as [TiF6−K]−, and molecule-like structures such as TiOF3−K. The results showed that the K+ ions are more likely to form structures with the titanium oxyfluorides. We also found that the melt with and without Ti0 showed almost completely different Raman bands. The information gained in this study for the coordination structure around titanium ions in the fluoride melts is significant towards the electrodeposition process of titanium-based materials in fluoride melt and marks an important step towards further understanding of the dissolution process of titanium oxyhalide structure in the melt.

β-MoSi2 is one of the expected silicide candidates for thermoelectric material because of its semi-conductive and metastable characteristics. However, it is not easy to fabricate β-MoSi2 phase under low temperature condition as easily anticipated from the equilibrium Mo-Si binary phase diagram. In this study, the formation of β-MoSi2 by electrochemical silicification of a Mo substrate with a thickness of 0.5 mm in CaCl2-based melts containing SiO2 has been confirmed. Throughout XRD analysis, the formation of metastable β-MoSi2 phase was identified on a Mo substrate by potentiostatic electrolysis below 973 K. The results of TEM combined with EDS analysis at the Mo/β-MoSi2 interface showed the inverse concentration gradients of Mo and Si in the width of ca. 25 nm. In addition, we examined the growth process of β-MoSi2 by using a partially Pt-coated Mo substrate since the reduction of Si ions does not proceed at the Pt-coated area. The cross-sectional SEM image of the substrate demonstrated that a homogeneous film of β-MoSi2 was grown with almost the same thickness on both sides of the Mo substrate and the melt region. The results indicated that the growth of β-MoSi2 was caused by the mutual diffusion of Mo and Si atoms.

Electrochemical reduction processes of oxides and injected CO2 in molten salt have been paid much attention as the carbon free technology to achieve the SDGs. We focused on La1− x Sr x FeO3− δ materials to utilizing O2 evolution electrode, because they intrinsically possess both oxygen ion conductivity and electron conductivity at elevating temperatures. Unfortunately, the properties have not been well examined in the molten salt despite the fundamental characteristics for the application to the inert anode. We found that La1− x Sr x FeO3− δ electrodes had excellent chemical and physical stability for keeping stable oxygen evolution reaction in the molten chlorides at 723 K.

Heart failure causes increased venous pressure, leading to liver dysfunction. The fibrosis-4 index is a simple index for liver fibrosis and has been reported to be useful for predicting prognosis in heart failure; however, its impact on patients with pulmonary hypertension due to left heart disease (PH-LHD) has not yet been fully elucidated.We enrolled consecutive 230 hospitalized patients who had been diagnosed as having PH-LHD. The fibrosis-4 index was calculated as follows: [aspartate transaminase (U/L) × age]/[alanine transaminase 1/2 (U/L) × platelet count (109/L) ]. We followed patients for all-cause mortality during the follow-up period (mean 1112 ± 822 days).The patients were divided into tertiles based on their fibrosis-4 index: the first tertile 0.335 to 1.381; the second tertile 1.391 to 2.311; and the third tertile 2.323 to 14.339. Compared with the first tertile, the third tertile had lower estimated glomerular filtration rates and hemoglobin levels. All-cause mortality was significantly higher in the third than in the first tertile. In a Cox proportional hazard model, the fibrosis-4 index was a predictor of all-cause mortality in PH-LHD patients (HR 1.212, 95% CI 1.099-1.337, P < 0.001).The fibrosis-4 index is associated with kidney function, anemia, and high mortality in PH-LHD patients.

Design studies on the helical fusion reactor FFHR-c1 have progressed. The main goal of the FFHR-c1 is to demonstrate one-year steady-state sustainment of the fusion plasma with self-produced fuel and electricity. The major radius of the plasma, R, is ˜10 m and the magnetic field strength at the plasma center, B, is ˜8 T. The magnet coil arrangement is basically similar to that of the LHD. The fusion gain during the one-year operation will be ˜15 with the fusion output of ˜370 MW. Three new technologies of the high-temperature superconducting magnet coils, the cartridge-type liquid blanket, and the fusible metal pebble divertor are adopted. Including these three, we have defined 22 important issues. The strategy to efficiently address the 22 issues has been also discussed. As a result, we propose a step-by-step approach by developing the FFHR-a1 (R ˜ 2.5 m and B ˜ 4 T) and the FFHR-b1 (R ˜ 3.6 m and B ˜ 6 T), before the FFHR-c1. The FFHR-b1 is a HElical Volumetric Neutron Source (HEVNS) driven by the neutral beam injection heating, and the FFHR-a1 corresponds to the pilot HEVNS.

Magnetic interaction between a tokamak reactor and its reinforced-concrete building has been analyzed using the analytical method and ANSYS electromagnetic code. Although it is better to use the non-magnetized material for the foundation of the air core tokamak building, it is interesting to study whether the magnetic material can be used in order to save the total cost of a fusion reactor. This study is motivated from the present ITER under construction in France. Assuming the iron plate approximation instead of discrete rebars, we analyzed the effect of the magnetized material on the magnetic field null regime in the plasma break down phase, x point location in the divertor operation, the magnetic force applied to the floor, and the induction effect on the iron floor. Although the effect of the magnetic material on the plasma performance is found to be not so crucial, the mechanical soundness of the floor due to the magnetic attractive force is most concern for machine safety.

The conceptual design of a helical fusion reactor was studied at the National Institute for Fusion Science in collaboration with other universities. Two types of the force free helical reactor (FFHR) are FFHR-d1 and FFHR-c1. FFHR-d1 is a self-ignition demonstration reactor that operates with a major radius of 15.6 m at a magnetic field intensity of 4.7 T. FFHR-c1 is a compact subignition reactor that aims to realize steady electrical self-sufficiency. Compared to FFHR-d1, FFHR-c1 has a magnetic field intensity of 7.3 T and a geometrical scale of 0.7. The location of the superconducting coils in both types of FFHR is based on that of the Large Helical Device (LHD). LHD has a major radius of 3.9 m. According to the design of LHD, the deformation must be within the required value to compensate for the accuracy of the magnetic field. According to this concept, the magnet support structure of LHD was fabricated using thick Type 316 stainless steel to impart sufficient rigidity. Thus, the stress of the magnet system of LHD is sufficiently below the permissible stress. In the case of FFHR, from the viewpoint of the reactor, a large access port is required for the maintenance of the in-vessel components. The mechanical design of the support structure is conceptualized by considering the basic thickness of the material and residual aperture space by referencing the mechanical analysis results. Details of the design concepts of LHD and FFHR-d1/FFHR-c1 as well as the results of mechanical analyses are introduced in this paper.

Li electrodeposition on liquid Ga substrates was carried out in PC-LiClO4 at 40 °C. It was found that interfacial flow phenomena were induced by differences in interfacial tension between the liquid Ga and the liquid Ga-Li alloy formed on the substrate under potentiostatic electrolysis at −1.0 V (vs. Li+/Li), which caused the interfacial shape change of the liquid Ga electrode. We carried out in-situ observations in order to understand why such interfacial phenomena occur between the liquid electrolyte and the liquid metal cathode. Moreover, a significant difference in electrochemical response between liquid and solid Ga substrates was also noticed employing the current-time transient technique. These experimental results suggest that the process of liquid Ga-Li phase formation by the dissolution of electrodeposited Li atoms into the liquid Ga substrate dominated during the initial stage of Li electrodeposition. In contrast, the typical peaks induced by growth of solid Ga-Li alloy phase and Li metal phase were observed on solid Ga substrates. These results provide new insight into the design of electrochemical processing involving liquid electrolyte/liquid metal interface. Keywords: Liquid metal electrode, Interfacial phenomenon, Non-aqueous solvent

FFHR-d1A and c1 are the conceptual design of a helical fusion reactor. The positional relationship among superconducting coils, a pair of helical coils with two sets of vertical-field coils, are observed to be similar in both type of FFHR. Such a relation of coil configuration is based on the coil configuration of the Large Helical Device, which has been designed and constructed at the National Institute for Fusion Science. There is increasing demand to achieve an optimized coil configuration to anticipate improvements in plasma-confinement conditions. In this study, the structural design of FFHR based on the fundamental set of parameters of coil configuration is depicted, which satisfies the soundness of the structure. Further, the effects of the coil configuration parameters on the stress distributions are investigated. An effect of radius of curvature on a winding scheme of the helical coil is also discussed.

Electrodeposition of titanium materials on substrates is an important technique to improve and functionalize the surface properties. Especially electrodeposition of titanium and titanium oxide on a material that is an insulator. However, electrodeposition of an insulator on another insulator is considered to be difficult. If such deposition can be accomplished, it would have a variety of practical applications in both mechanical and electronic industries. We are thus proposing a new method for electrodeposition of titanium oxide on alumina substrates in LiF-KF with the addition of TiO2 and metal titanium. We have carried out the electrodeposition to test hypotheses on deposition of titanium oxide on the alumina surface by employing the three electrodes method in the molten salt. The nickel-wire in contact with alumina substrate was employed as a working electrode to grow titanium oxide on the substrate by the proposed electrochemical process. Titanium oxide deposition grew from the three-phase interface of nickel wire, molten salt and alumina substrate in a radial pattern. The growth rate of the deposition was controlled by adjusting the electrochemical parameters. We have also investigated the melt structure of LiF-KF with the addition of TiO2 and the addition of bulk titanium by combining high temperature Raman spectroscopic technique and density functional theory calculations. These results provide new insight into the growth process of titanium oxide crystals and possibly a new comprehensive plating procedure for titanium oxide on insulator substrates.

Metal silicides are attracting attention as environment-friendly functional materials because they are composed of abundant elements in the earth’s crust. However, conventional processes for preparing silicides from SiO2 as the starting material consume a lot of energy and utilize hazardous materials through the reduction process of SiO2. Against this background, the electrochemical process in molten salt become key technology for fabricating silicon materials in an environmentally friendly, simple, and inexpensive process. We have already reported the electrodeposition of metallic silicon films from SiO2 in high temperature molten salt. This process has the potential to develop environmentally friendly and sustainable systems for fabricating silicon materials by combining non-consumable oxygen-evolving anodes. In this study, we focused on the electrochemical formation of molybdenum silicide from SiO2 in molten chloride because the molybdenum silicide are promising materials for ultra-high temperature protective coating, heating element, and thermoelectric conversion element. We report here the electrochemical formation of molybdenum silicide in CaCl2-based molten chloride containing SiO2 system. A Mo substrate was used as the working electrode. From the results of characterization by XRD, SEM, and EDS analysis, a metastable β-MoSi2 phase and stable α-MoSi2 phase were obtained by controlling applied potentials during potentiostatic electrolysis. In addition, since the nucleation and growth process of the silicide is very important to control its structure, composition and morphology, the electrolytic time transient between molybdenum substrate/molten chloride interface were carefully observed by SEM analysis. The fundamental research on formation process of silicides in molten salt will greatly contribute to materials science in high temperature environment and developing the novel rout for fabricating silicon materials.

Background/aim Although the pathology of sinusoidal obstruction syndrome (SOS) is characterized by damage to liver sinusoidal endothelial cells (LSECs), the processes underlying LSEC repair are incompletely understood. The angiopoietin (Ang)/Tie system contributes to angiogenesis. The present study aimed to examine the processes of LSEC repair and the involvement of the Ang/Tie pathway in LSEC recovery. Materials and methods Experimentally, SOS was induced by intraperitoneal injection of monocrotaline (MCT) to C57/BL6 mice. Results Levels of LSEC markers were up-regulated during the repair phase of MCT-induced hepatotoxicity. The damaged LSECs recovered from the injury by expanding LSECs expressing lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) in the peri-central area of MCT-injured livers, while LSECs in the same area of uninjured livers lacked LYVE-1 expression. Bone marrow (BM)-derived cells did not incorporate into the restored LSECs. Tie2 expression was related to LSEC recovery in MCT-injured liver tissue. Conclusion The resident LSECs neighboring uninjured tissue replace damaged LSECs in MCT-injured livers. Tie2 is involved in LSEC recovery from MCT-induced hepatotoxicity.

We describe a seven-month-old boy with tetralogy of Fallot and an absent left pulmonary artery. Due to the diminutive size of the left pulmonary artery, we performed a native tissue left pulmonary artery reconstruction and intrapulmonary artery septation procedure with a left modified Blalock-Taussig shunt. After confirming left pulmonary artery growth, the patient underwent tetralogy of Fallot repair, removal of septation patch, and division of the Blalock-Taussig shunt. Nine months post-surgery, we confirmed his balanced lung perfusion (R/L ratio 6:4). The intrapulmonary artery septation procedure would be suitable for both the resuscitation and reconstruction of the hypoplastic absent pulmonary artery.

The right internal thoracic artery to the right coronary artery bypass with ligation of the proximal native vessel is a simple and reliable option for the treatment of an anomalous aortic origin of the right coronary artery arising from the left sinus of Valsalva without an intramural course. Coronary artery bypass grafting is an uncomplicated option for elderly patients, those with connective tissue diseases, and those for whom combined aortic valve procedures are planned. Herein, we present four cases of this anomaly that underwent right internal thoracic artery anastomosis to the distal right coronary artery along with proximal right coronary artery ligation using a surgical clip. There was no occurrence of complications such as hypoperfusion syndrome, graft occlusion, recurrent symptoms, or late cardiac events.