• Title/Summary/Keyword: High-$T_{c}$

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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.
    • Progress in Superconductivity and Cryogenics
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    • v.16 no.2
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    • pp.1-6
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    • 2014
  • 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.

The Association between A-FABP Promoter Genotype and Carcass Traits in Pigs (비육돈의 도체형질과 A-FABP Promoter 유전자형의 연관 분석)

  • Han, Sang-Hyun;Cho, In-Cheol;Lee, Chong-Eon;Ko, Moon-Suck;Seong, Pil-Nam;Park, Beom-Young
    • Food Science of Animal Resources
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    • v.27 no.3
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    • pp.382-386
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    • 2007
  • The association between the promoter region genotypes of the porcine adipocyte fatty acid binding protein (A-FABP) gene and carcass traits in commercial pigs was examined. Interestingly, only two different genotypes (-406T/T and T/C) for the A-FABP gene were detected using Hinf-RFLP for the substitution mutation T-406C in the A-FABP promoter in commercial pigs, and no -406C/C homozygotes were detected. The reason for the lack of the -406 C/C genotype is due to the breeding system in which only Duroc, which has a high frequency of -406C/- in this locus among the three breeds involved in commercial pig production, is typically used as a terminal sire. The pigs containing the genotype -406C/- were significantly associated with an increase in intramuscula. fat content and carcass weight (p<0.05), but there was no association with the other carcass traits tested (fat composition, color score, texture score, moisture, and separation score between muscles). This study suggests that the -406C/- genotype of the porcine A-FABP gene may not only be a useful molecular marker for intramuscular fat, but may also contribute to the improvement of meat quality by the production of well-marbled pigs by breeding animals containing this genotype, especially Duroc, as a terminal sire for commercial pigs.

A High Performance AC Propulsion System for Electric Car (전동차용 고성능 AC구동시스템의 개발)

  • Jung, K.C.;Bang, L.S.;Kim, D.S.;Seo, K.D.;Kim, N.H.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.278-280
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    • 1996
  • This paper presents a high performance AC propulsion system for electric car to improve traction capability. The presented VVVF inverter was composed of as GTO thyristor and the the controller was fully digitalized by using 32bit DSP. The improved PWM algorithms and the new adhesion control were adapted to improve traction characteristics. This system could be possible the higher reliability and flexibility. The field test results showed the higher performances characteristics of the presented system.

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The development of membranes for high temperature PEMFC

  • Lee, Doo-Yeon;Sun, Hee-Young;Cho, Chung-Kun;Lee, Myung-Jin;Seung, Do-Young
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.184-184
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    • 2006
  • We have succeeded in the preparation of high molecular weight polybenzimidazoles by solution polycondensation of 3,3'-diaminobenzidine tetrahydrochloride with isophthalic acid, terephthalic acid, or with their derivatives using polyphosphoric acid both as solvent and as condensing agent. Also, we modified phosphoric acid into fluoroalkyl-phosphonic acids[F-PA]. The main reasons are as follows, first of all F-PAs are stronger acids than PA and alkylphosphonic acids which should promote proton hopping and transport. In addition, F-PA has weaker adsorption onto Pt which help to prevent electrocatalyst poisoning and promote higher oxygen reduction activity. The ionic conductivity of 85%-H3PO4 doped membranes show $10^{-2}\;Scm^{-1}\;to\;3{\times}10^{-2}\;Scm^{-1}\;at\;150^{\circ}C$ MEA with 2 %-added electrolyte shows slightly higher cell voltage than the others.

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CO OBSERVATIONS OF A HIGH VELOCITY CLOUD

  • Kim, K.T.;Mihn, Y.C.;Hasegawa, T.I.
    • Journal of The Korean Astronomical Society
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    • v.22 no.1
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    • pp.25-30
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    • 1989
  • We report a null detection of $^{12}CO$ emission from a sub-condensation in a High Velocity Cloud (HVC). As a consequence of this, an upper limit of $n(H_2)\frac{X(CO)}{DV/DR}{\leq}2{\times}10^{-5}$ was set. This implies that $^{12}CO$ abundance is deficient by at least a factor of 10 if the HVC is predominantly molecular, otherwise the CO abundance of the HVC might be normal.

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Junction, Circuit and System Developments for a High-$T_c$ Superconductor Sampler

  • Hidaka, M.;Satoh, T.;Tahara, S.
    • Progress in Superconductivity
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    • v.1 no.2
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    • pp.81-84
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    • 2000
  • A Josephson sampler circuit using high-Tc superconductor (HTS) ramp-edge junctions has been designed, fabricated, and experimentally tested. It consists of five ramp-edge junctions with a stacked groundplane and is based on single-flux-quantum (SFQ) operations. The sampler was used to measure current waveforms at picosecond and microampere resolutions. We are developing a system based on the sampler for measuring the current waveform in a room-temperature sample. And measuring current flowing through wiring in a semiconductor large-scale integrated circuit is a promising application for the HTS sampler system.

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Varietal Variation in Gelatinization and Adaptability to Rice Bread Processing and Their Interrelation (쌀의 호화 및 제빵적성의 품종 변이와 관련특성간 상관)

  • 강미영;손현미;최해춘
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.344-351
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    • 1997
  • The experiment was conducted to examine the varietal variation in gelatinization of rice flour and adaptability to rice bread processing, and the interrelation among the relevant properties. IR 44 showed the lowest temperature of gelatinization onset(T$_{o}$ ) and the highest gelatinization enthalphy(ㅿH) measured by differential scanning calorimetry (DSC). The following lower T$_{o}$ was found with the order of Suweon 230<Pusa-33-30<T(N) 1, Daeribbyeo 1 and the next higher ㅿ.H was followed by the order of Pusa-33-30>Suweon 230. IRAT 177 revealed the highest temperature of gelatinization onset and conclusion(T$_{c}$) and the following higher T$_{c}$ was found with the order of Pusa-33-30>AC 27>Nonganbyeo. The varietal range of T$_{o}$ and T$_{c}$ was 50.0~72.5$^{\circ}C$ and 70.2~87.4$^{\circ}C$, respectively. The rice materials tested can be classified by scatter diagram on the plane of upper two principal components contracted from DSC thermogram and various characteristics relevant to processing and sensory preference of rice bread by principal component analysis. AC27, Suweonjo and IR 44 among high-amylose rices showed better suitability to rice bread processing. The temperatures of gelatinization peak and conclusion of rice flour checked by DSC were significantly negatively associated with springiness of rice bread. The most properties relevant to processing and sensory preference of rice bread such as hardness, moistness, springiness, cohesiveness, specific loaf volume and distribution or size of air cell revealed the close correlation between each other.other.

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Quality and Shelf-Life of Vacuum Packed RTE (Ready-To-Eat) Hamburg Steak Depending on the Oxygen Permeability of Packaging Material and the Storage Temperature (포장재의 산소투과도와 저장온도에 따른 즉석섭취형 햄버그스테이크의 품질 및 저장성)

  • Lim, Ji Hoon;Lee, Sung Ki;Chung, Seung Hee;Lee, Keun Taik
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.22 no.3
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    • pp.95-102
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    • 2016
  • This study investigated the effects of the oxygen permeability of vacuum packaging film and the storage temperature on the quality and shelf life of Hamburg steaks during storage for 14 days. Control samples (C) were packaged in a polyamide/polyethylene (PA/PE) film and stored at $5^{\circ}C$. Treatment samples were either packaged in an ethylene vinyl alcohol/polyethylene (EVOH/PE) copolymer film and stored at $5^{\circ}C$ (T1), and in a PA/PE film and stored at $-18^{\circ}C$ (T2). The initial total plate count (TPC) was 3.6 log cfu/g. In T1 samples, TPC and Brochothrix thermosphacta counts were increased, similar to those in C samples, whereas Pseudomonas spp. counts were significantly lower than those in C samples during storage. Over the storage period, the volatile basic nitrogen values increased most rapidly in C samples, followed by T1 and then T2 samples. The values of thiobarbituric acid reactive substances steadily increased in all samples during storage. The colour parameters were not significantly different among the samples during storage. T1 samples maintained sensory qualities in flavour and off-odour parameters for two days longer than C samples did. At day 12, T2 samples were evaluated as being below the marketability score of 5.0 for texture. In conclusion, using high oxygen barrier films like EVOH/PE copolymer for packaging Hamburg steaks could extend the sensory qualities in view of flavour and off-odour during chilled storage. However, frozen storage at $-18^{\circ}C$ is recommended when the storage period is extended beyond 14 days at $5^{\circ}C$.

Growth of Hexagonal Boron Nitride Thin Films on Silicon Using a Single Source Precursors

  • Boo, Jin-Hyo;Lee, Soon-Bo;Casten Rohr;Wilson Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.120-120
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    • 1998
  • Boron nitride (BN) films have attracted a growing interest for a variety of t technological applications due to their excellent characteristics, namely hardness, c chemical inertness, and dielectrical behavior, etc. There are two crystalline phases 1551; of BN that are analogous to phases of carbon. Hexagonal boron nitride (h-BN) has a a layered s$\sigma$ucture which is spz-bonded structure similar to that of graphite, and is t the stable ordered phase at ambient conditions. Cubic boron nitride (c-BN) has a z zinc blende structure with sp3-bonding like as diamond, 따ld is the metastable phase a at ambient conditions. Among of their prototypes, especially 삼Ie c-BN is an i interesting material because it has almost the same hardness and thermal c conductivity as di없nond. C Conventionally, significant progress has been made in the experimental t techniques for synthesizing BN films using various of the physical vapor deposition 밍ld chemical vapor deposition. But, the major disadvantage of c-BN films is that t they are much more difficult to synthesize than h-BN films due to its narrow s stability phase region, high compression stress, and problem of nitrogen source c control. Recent studies of the metalorganic chemical vapor deposition (MOCVD) of I III - V compound have established that a molecular level understanding of the d deposition process is mandatory in controlling the selectivity parameters. This led t to the concept of using a single source organometallic precursor, having the c constituent elements in stoichiometric ratio, for MOCVD growth of 삼Ie required b binary compound. I In this study, therefore, we have been carried out the growth of h-BN thin f films on silicon substrates using a single source precursors. Polycrystalline h-BN t thin films were deposited on silicon in the temperature range of $\alpha$)() - 900 $^{\circ}$C from t the organometallic precursors of Boron-Triethylamine complex, (CZHs)3N:BRJ, and T Tris(dimethylamino)Borane, [CH3}zNhB, by supersonic molecular jet and remote p plasma assisted MOCVD. Hydrogen was used as carrier gas, and additional nitrogen w was supplied by either aDlIDonia through a nozzle, or nitrogen via a remote plasma. T The as-grown films were characterized by Fourier transform infrared spectroscopy, x x-ray pthotoelectron spectroscopy, Auger electron spectroscopy, x-ray diffraction, t transmission electron diffraction, optical transmission, and atomic force microscopy.roscopy.

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Synthesis and Thermal Properties of PPS/PPSS Copolymer (PPS/PPSS 공중합체의 합성 및 열적 성질)

  • Park, Lee-Soon;Lee, Tae-Hyung;Kwak, Kyu-Dae;Haw, Jung-Rim
    • Applied Chemistry for Engineering
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    • v.9 no.3
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    • pp.440-444
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    • 1998
  • Poly(phenylene sulfide-co-phenylene sulfide sulfone), PPS/PPSS copolymers were synthesized from p-dichlobenzene(DCB), p-dibromobenzene(DBB), p-diiodobenzene(DIB), 4-chlorophenyl sulfone(CPS) and sodium sulfide as comonomers under high temperature and pressure utilizing N-methyl-2-pyrrolidinone(NMP) as solvent. The yield of PPS/PPSS copolymer shoed maximum at $190^{\circ}C$ with [DBB]/[CPS] and [DIB]/[CPS] comonomer pair, while [DCB]/[CPS] pair exhibited maximum yield at $230^{\circ}C$. The change of yield is in the order of I>Br>Cl as leaving groups were in accordance with nucleophilic aromatic substitution reaction mechanism suggested for the synthesis of PPS type polymers. The molecular weight of PPS/PPSS copolymer was the highest($M_w=8,330g/mol$) with [DBB]/[CPS] comonomers in which [CPS] was 10 mole%. The PPS/PPSS copolymer made with 10 mole% of [CPS] showed about $15^{\circ}C$ higher $T_g$ and $15^{\circ}C$ lower $T_m$ than those of PPS homopolymer, which may be useful from the processing and thermal property point of view. The PPS/PPSS copolymer with 30 mole% of CPS or above did not exhibit Tm. The PPS/PPSS copolymer obtained with comonomer feed ratio of [DBB]/[CPS] = 95/5 mole% under $240^{\circ}C$ showed even higher molecular weight($M_w=10,300g/mole$) than PPS homopolymer made under similar reaction condition, retaining high crystallinity and thermal stability.

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