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ABSTRACT: The demonstration and verification tests of a 500 m High-Tc superconducting (HTS) cable were carried out at the CRIEPI laboratory in Yokosuka from March 2004 to March 2005. The HTS cable consisted of a cold dielectric core with nominal capacity of 77 kV and 1 kA that had an HTS shield layer. CRIEPI and Furukawa have conducted tests for investigating the basic properties of the cable and a long-term loading test for confirming 30-year operations. Moreover, we conducted an "over-loading test" and a "cooling system fault test" to investigate the reliability and safety of the cable. After all field tests, the cable was dismantled and taken away from the site to Furukawa's factory for internal inspection. No Ic degradation was found in the HTS conductor, but local degradation was seen in the HTS shield. These degradations might have arisen because protective layer for the shield did not have enough thickness but were within the acceptable range of about 5%.
IEEE Transactions on Appiled Superconductivity 07/2007; · 1.04 Impact Factor
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ABSTRACT: A high-temperature superconducting (HTS) power transmission cable is considered as one of the next-generation power transmission technologies. The introduction of HTS cables into the actual power grid requires a long-distance cooling tube, due to the location of the cooling stations at intervals of several kilometers along the cable length. Therefore, it is essential to understand the flow property of the liquid nitrogen as a coolant for the HTS cable, the current flow properties, electrical insulation characteristics, thermal insulation properties and mechanical behavior for the HTS cable taking into account its long length. This paper provides a brief summary of the HTS cable test system with a length of 500 m constructed in the Yokosuka area of CRIEPI.
IEEE Transactions on Appiled Superconductivity 07/2005; · 1.04 Impact Factor
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ABSTRACT: We have investigated morphology change of FePt nanogranular films (FePt)47(Al2O3)53 under irradiation with 210 MeV Xe ions. Here, electron tomography technique was extensively employed to clarify three-dimensional (3D) structure in irradiated specimens, in addition to conventional transmission electron microscopy (TEM) techniques such as bright-field observation and scanning TEM energy dispersive X-ray spectroscopy (STEM-EDX) analysis. The ion irradiation induces the coarsening of FePt nanoparticles with elongation along the beam direction. Electron tomography 3D reconstructed images clearly demonstrated that when the fluence achieves 5.0 × 1014 ions/cm2, well-coarsened FePt balls have been formed on the irradiated surface, and the particles in the film interior have been deformed into rods along the ion trajectory. The alloy particles become inhomogeneous in composition after prolonged irradiation up to 1.0 × 1015 Xe ions/cm2. The particle center is enriched with Pt, while Fe is slightly redistributed to the periphery.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms.
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ABSTRACT: By using the PIGE technique at JAERI Takasaki, we have measured fluorine (F) distribution in a micro-area of a tooth. Class V cavities were bored at the cement–enamel junction in the buccal face of the teeth and were filled with F-releasing dental materials. Five kinds of F-releasing dental materials were applied. The 1.7 MeV proton beam accelerated by the TIARA single-ended accelerator was delivered to a micro-beam apparatus. The beam spot size was about 1 μm with a beam current of about 100 pA. A nuclear reaction 19F(p,αγ)16O was used for measuring the F concentration. Gamma rays of this reaction were detected with a 4″ NaI(Tl) detector. Proton induced X-rays were detected with a Ge detector for measuring the calcium concentration. The beam intensity was monitored with the X-ray yield from a copper foil for quantitative analysis. The obtained results were shown in the form of two dimensional mapping. The F moved slowly into the tooth from F-releasing materials by diffusion and/or other processes. It was affirmed that the PIGE technique is a very powerful non-destructive tool for characterizing F in a tooth.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms.
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ABSTRACT: We have investigated the magnetic properties of Fe38.5Pt, Fe39.5Pt and Fe50.0Pt (at%) alloys after various heat treatment conditions using a vibrating sample magnetometer, and correlated these properties with the microstructures of the alloys by transmission electron microscopy. The Fe50Pt alloy shows poor magnetic hardness regardless of the heat treatment conditions. The magnetic hardness of the Fe39.5Pt alloy shows a maximum value after annealing for 10 h at 873 K, while it monotonically decreases after annealing at 1073 K. The alloy with the highest coercivity was composed of a single phase γ1 with an average domain size of approximately 10 nm. The electron diffraction results indicate that the alloy is frustrated with accumulated stress, induced by a cubic → tetragonal transformation which occurs without twinning. On the other hand, when stress is relieved by twin formation after prolonged aging, the coercivity decreases. By annealing at 1073 K, the well known polytwin structure evolves. However, only poor hard magnetic properties are observed when this polytwin structure appears. Hence, the highest coercivity is attributed to the formation of nanoscale L10 ordered antiphase domains which is expected to be a highly anisotropic single domain magnetic particle.
Journal of Magnetism and Magnetic Materials.
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H. Kadowaki, K. Yasuda,
K. Iwamoto,
S. Otabe,
K. Shimokawa,
K. Silver,
J. Walston,
H. Yoshinaga,
K. Kosaka,
N. Yamada,
Y. Saito,
R. Hagura,
Y. Akanuma,
A. Shuldiner,
Y. Yazaki,
T. Kadowaki
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ABSTRACT: The Trp 64 Arg mutation in the β3-adrenergic receptor (β3AR) gene was investigated in 350 Japanese subjects. This mutation was not associated with non-insulin-dependent diabetes mellitus (NIDDM). In 191 subjects without NIDDM, body mass index (BMI) was significantly higher in subjects homozygous for this mutation than in those homozygous for the normal allele (24.7±1.4 vs 22.1±0.2 kg/m2, p=0.009). Moreover, the frequency of the mutant allele in obese subjects (BMI>26.4) was significantly higher than that in non-obese subjects (BMI<22) (0.37 vs 0.15, p=0.009). The presence of this mutation was also accompanied by significantly higher fasting (p=0.000) and 2 hrs (p=0.018) serum insulin levels during an oral glucose tolerance test. The β3AR may be one of the loci contributing to obesity and hyperinsulinemia/insulin resistance in Japanese subjects.
Biochemical and Biophysical Research Communications.
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ABSTRACT: The evolution of radiation-induced damage in fully-stabilized, cubic zirconia (FSZ) (Y, Ca and Er dopants acting as stabilizers) and in pure, unstabilized, monoclinic zirconia, was investigated using Rutherford backscattering spectrometry and ion channeling (RBS/C), along with X-ray diffraction and transmission electron microscopy (TEM). FSZ crystals were irradiated with 340–400 keV Xe++ ions and at temperatures ranging from 170 to 300 K, or with 127I+ ions (72 MeV) at temperatures ranging from 300 to 1170 K. No amorphization of zirconia was found under any irradiation condition, though in the case of 72 MeV I+ ion irradiations, the irradiation-induced defect microstructure was observed to produce dechanneling effects in RBS/C measurements that reach the `random' level. Damage accumulation in Xe-ion irradiation experiments on FSZ crystals was found to progress in three stages: (1) formation of isolated defect clusters; (2) a transition stage in which damage increases rapidly over a small range of ion dose, due to the linking of dislocations and defect clusters; and (3) a `saturation' stage in which damage accumulation is retarded or increases only slowly with ion dose. The FSZ crystal composition does not seem to alter significantly the dose-dependence of these damage stages. Unstabilized, monoclinic ZrO2 was observed to transform to a higher symmetry, tetragonal or cubic phase, upon 340 keV Xe++ ion irradiation to Xe fluences in excess of (dose equivalent, ∼2 displacements per atom or dpa) at 120 K. This transformation was accompanied by a densification of the ZrO2 phase by ∼5%. No amorphization of the pure ZrO2 was observed to a Xe++ ion fluence equivalent to a peak displacement damage level of about 680 dpa.
Journal of Nuclear Materials.
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ABSTRACT: Using the proton induced gamma-ray emission (PIGE) method (TIARA, Japan), we have studied fluorine (F) distribution in the human tooth under various conditions. Here, we report F uptake into the human tooth from a thin layer of F-releasing low viscous resin (FLVR). Crowns of human teeth were horizontally cut and the dentin of the cut surface was first covered with four kinds of FLVR (FL-Bond, Reactmer Bond, Xeno Bond, and Protect Liner F; thickness, 50–150 μm) according to the manufacturers’ instructions. Non-F-releasing and F-releasing filling resins were also hardened, on the cut surfaces of crowns covered with four kinds of FLVR thin layers. The type of the non-F-releasing filling materials used was LITE FIL IIP: G1-A (FL-Bond and LITE FIL IIP), G2-A (Reactmer Bond and LITE FIL IIP), G3-A (Xeno Bond and LITE FIL IIP), and G4-A (Protect Liner F and LITE FIL IIP). The types of F-releasing filling materials used were G1-B (FL-Bond and Beautifil), G2-B (Reactmer Bond and Reactmer Paste), G3-B (Xeno Bond and Xeno CF Paste), and G4-B (Protect Liner F and Teethmate F-1). Treatment and measurements of specimens were the same as previously reported [H. Yamamoto, M. Nomahci, K. Yasuda, Y. Iwami, S. Ebisu, N. Yamamoto, T. Sakai, T. Kamiya, Nucl. Instr. and Meth. B 210 (2003) 388]. F uptake from specimens following one month of application was estimated from 2-D maps.F penetration was observed in all teeth of G1-A–G4-A groups. The maximum values of F concentration in each tooth and F penetration depth were larger for larger F concentrations in FLVR. FLVR was useful for the F uptake into the tooth, and the F distribution near the thin layer of FLVR depended on the materials used. Between G1-A and G1-B or G4-A and G4-B, the F uptake was significantly different. We were able to obtain fundamental data, which were useful for the analysis of F transportation relating to prevention of caries.
Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 260(1):194-200. · 1.21 Impact Factor
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ABSTRACT: Recently, adoptive immunotherapy for cancer with lymphokine activated killer (LAK) cells has been widely used experimentally. The therapy has several problems, including difficulty in handling, sterilization, and time consumption. To solve these problems, new materials able to induce antitumor immune cells were investigated. Pokeweed mitogen (PWM) and PWM-conjugated materials (CMC-1) could induce strong killer cells by short-term stimulation of human peripheral blood lymphocytes (PBL). The induced killer cells showed a wide killing spectrum in vitro against human tumor cell lines (MKK-1, PRMI4788, NBT-2, ZR-7530, H-1, Hela, KB, HMV-1, PC-10, C-1). Human PBL stimulated for a short time by CMC-1 also showed a tumoricidal effect on tumor bearing (MKN-1, MKN-45) nude mice. These results suggest that CMC-1 may solve the problems with currently used LAK therapy and may provide easily applicable extracorporeal immunotherapy for cancer.
ASAIO transactions / American Society for Artificial Internal Organs 36(3):M209-11.
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ABSTRACT: By using the PIGE technique at JAERI Takasaki, we measured fluorine (F) distribution in a micro area of occlusal fissures in the enamel of human teeth. The fissures were classified into three groups: Group I, no caries; Group II, incipient caries; Group III, advanced caries. The extracted teeth were embedded in epoxy resin and cut along the longitudinal axis through the fissures. The F concentration in the fissure at the cut surface was measured. A 1.7 MeV proton beam accelerated by the TIARA single-ended accelerator was delivered to a micro-beam apparatus. The beam spot size was about 1 μm with a beam current of about 100 pA. A nuclear reaction, 19F (p,αγ)16O, was used to measure the F concentration and gamma-rays from this reaction were detected with a 4″ NaI(Tl) detector. X-rays induced by proton were detected with a Ge detector to measure calcium concentration and the beam intensity was monitored with the X-ray yield from a copper foil for quantitative analysis. The obtained results were shown as two-dimensional mapping. In all specimens, an F concentration was observed around the fissure. The F concentration varied depending on the location of the fissure and decreased towards the inner part of the tooth. The maximum F concentration values in the measured area ranged from 3500–11700 ppm (mean = 6000 ppm) in Group I, 2400–10700 ppm (mean = 6300 ppm) in Group II, and 5200–16900 ppm (mean = 9300 ppm) in Group III. Although high F concentrations tended to be measured in the carious fissures, high values were also recognized in the sound fissures. More studies are necessary to clarify the relationship between F and carious lesions.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms.
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S. Mukoyama,
S. Maruyama,
M. Yagi,
N. Ishii,
H. Kimura,
H. Suzuki,
M. Ichikawa,
T. Takahashi,
T. Okamoto,
A. Kimura, K. Yasuda
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ABSTRACT: A high-Tc superconducting cable (HTS cable) can transmit more power with lower loss than conventional cables. HTS cable is expected to be a compact and economical transmission line to meet the increasing electrical demands of cities. However, some technical problems must be solved to bring the HTS cable into practical use. Demonstration and verification tests of the world’s longest (500 m) HTS cable have been carried out as part of the Super-ACE project. The 500 m cable was a single-core, cold-dielectric type with a small enough diameter to be installed inside a 150 mm cable duct. We have already successfully completed the production and installation required for the field tests at the Yokosuka laboratory of CRIEPI. The test layout included a 10 m high section, an underground section and an offset section for absorbing the thermal contraction, so as to simulate real transmission lines. Over the course of a year, CRIEPI and Furukawa Electric have conducted numerous experiments on the thermo-mechanical behavior and operating characteristics of the cooling system and the electrical and superconducting properties of the cable, both at its rated load and with a fluctuating load and an overload.
Physica C: Superconductivity.
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ABSTRACT: Objective. The effects of freezing on the remodelling process of the patellar tendon were examined.Design. An experimental study in rabbits.Background. Patellar tendon weakens when grafted as a subsstitute for the anterior cruciate ligament. Fibroblast necrosis is considered to be one of the many factors contributing to this change. Therefore, the effect of freeze-induced necrosis on the patellar tendon has been studied.Methods. Using a technique for freezing the patellar tendon in situ with liquid nitrogen to kill fibroblasts, we studied the biomechanical and histological changes in the patellar tendon up to 24 weeks after freezing.Results. The cross-sectional area started to increase by week 3, reaching a plateau by week 12. The elastic modulus and tensile strength began decreasing by week 3. Although the maximum load decreased at weeks 12 and 24, the stiffness did not change. Histologically, cells were absent until week 2. Athough cells were apparently normal at week 24, there were none of the dense collagen bundles that are normally seen.Conclusions. The once-frozen patellar tendon weakens as tissue remodelling occurs.
Clinical Biomechanics.
