• 제목/요약/키워드: AC4C

검색결과 613건 처리시간 0.027초

PAI 유/무기 하이브리드코일의 곡률변화에 따른 AC 및 DC 절연파괴 특성 (Insulation Breakdown Properties of AC and DC according to Curvature Variation of PAI Organic/Inorganic Hybrid Coils)

  • 박재준
    • 전기학회논문지
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    • 제65권10호
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    • pp.1721-1726
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    • 2016
  • 4-types of coils were prepared by coating with polyamideimide (PAI) organic/inorganic hybrid. One type was made with original PAI vanish and the other 3-types were made of double layers, that was to say, high flexural PAI layer and high anti-corona PAI/nanosilica (15 wt%) layer. Drying temperature (T/D) were $220^{\circ}C$, $240^{\circ}C$, and $260^{\circ}C$, respectively and rectangular type coil for high-voltage rotating machine was used. DC and AC electrical breakdown tests were carried out in order to study the insulation properties according to T/D temperature and coil curvature (5, 15, and $25mm{\Phi}$). As the curvature increased, electrical breakdown voltage decreased and as T/D temperature decreased, electrical breakdown voltage increased.

광섬유 마이켈슨 간섭계형 교류 전류센서 (Fiber-Optic Michelson Interferometric AC Current Sensor)

  • 김창원;박동수;김명규;이정희;강신원;손병기
    • 센서학회지
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    • 제4권2호
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    • pp.22-28
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    • 1995
  • 인가 전압에 의해 수축 팽창하는 원통형 PZT tube와 단일모드 광섬유를 이용하여 마이켈슨 간섭계형 교류 전류센서를 제작하였다. 본 연구에 사용된 신호처리장치는 측정전류의 주파수에 무관하게 전류의 크기를 측정할 수 있었다. 전류의 크기는 교류 전류의 반주기 내에 생기는 간섭무늬의 개수로 측정하였다. 간섭무늬의 개수는 전류의 크기에 따라 선형적으로 변화하였으며, 온도변화($-20^{\circ}C{\sim}\;80^{\circ}C$)에 따른 오차는 5% 이내였다.

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합성된 PGE-AcAm이 에폭시 수지 계의 반응속도의 미치는 영향 (Effect of Synthetic PGE-AcAm on the Reaction Rate of Epoxy System)

  • 이재영;심미자;김상욱
    • 한국재료학회지
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    • 제6권6호
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    • pp.644-650
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    • 1996
  • Diglycidy1 ether of bisphenol A (DGEBA)/4,4'-methylene dianiline(MDA)계의 경화반응 속도에 미치는 pheny1 glycidy1 ether (PGE)-acetamide(AcAm)의 영향을 연구하였다. 반응성 첨가제로 사용된 PGE-AcAm는 PGE와 acetamide를 2:1의 몰 비로 혼합한 후 18$0^{\circ}C$에서 1시간 반응시켜서 합성하였으며, PGE의 에폭사이드기와 AcAm의 아민기가 반응함으로써 수산기를 형성함에 의해 진행되었다. 이 때 생성된 수산기는 DGEBA와 MDA의 반응에서 촉매로 작용하여 반응속도를 크게 활성화 에너지는 11.11 Kcal/mol이었고, 30 phr의 PGE-AcAm이 첨가된 계의 활성화 에너지는 7.91Kcal/mol이었다.

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AC2A 합금의 양극 산화 피막 형성에 미치는 석출물의 영향 (Effect of second-phase particles on the formation of anodic oxide films on AC2A alloy)

  • 남윤경;문성모;김종화
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2009년도 추계학술대회 초록집
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    • pp.205-206
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    • 2009
  • 다량의 석출물을 포함하고 있는 AC2A 합금을 $0^{\circ}C$에서 2.25M H2SO4에서 양극산화처리를 행하여 피막형성 거동을 관찰하였다. 주조용 알루미늄 합금은 다량의 석출물을 포함하고 있고 석출물들은 산화피막의 형성에 영향을 미치게 된다. 본 연구에서는 주조용 AC2A합금의 양극 산화 피막의 형성에 미치는 석출물들의 영향을 OM, SEM, LSCM을 사용하여 정밀하게 관찰해 보았다.

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도전재 종류에 따른 $LiMn_2O_4$정극의 AC Impedance 측정 및 충방전 특성 (AC Impedance analysis and charge/discharge characteristics of $LiMn_2O_4$ cathode according to conductive agent)

  • 정인성;성창호;박복기;구할본
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 C
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    • pp.1594-1596
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    • 1997
  • $LiMn_2O_4$ is prepared by reacting stoichiometric mixture of LiOH $H_2O$ and $MnO_2$ (mole ratio 1 : 2) and calcinating at $800^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. At X-ray diffraction, cathode active materials calcined at $800^{\circ}C$ for 36h. (111)/(311) peak ratio was 0.37. It was that crystal structure is formed very well. In the result of charge/discharge test, when heated at $800^{\circ}C$ for 36h, charge/discharge characteristics of $LiMn_2O_4$ is the best and Super-s-black sort of conductive agent showed well property. Also, AC impedance creased gradually during cycling and stabilized after 10cycle.

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Implementation of an Adaptive Robust Neural Network Based Motion Controller for Position Tracking of AC Servo Drives

  • Kim, Won-Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제9권4호
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    • pp.294-300
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    • 2009
  • The neural network with radial basis function is introduced for position tracking control of AC servo drive with the existence of system uncertainties. An adaptive robust term is applied to overcome the external disturbances. The proposed controller is implemented on a high performance digital signal processing DSP TMS320C6713-300. The stability and the convergence of the system are proved by Lyapunov theory. The validity and robustness of the controller are verified through simulation and experimental results

천문동 뿌리의 자연발효에 관여하는 미생물 및 발효 후 효능 변화 (Microorganisms Involved in Natural Fermentation of Asparagus cochinchinensis Roots and Changes in Efficacies after Fermentation)

  • 김민지;신나래;이명종;김호준
    • 한방비만학회지
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    • 제18권2호
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    • pp.96-105
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    • 2018
  • Objectives: The aim of this study was to examine the effect of Asparagus cochinchinensis (AC) and fermented AC (fAC) on microorganisms and efficacies. Methods: AC was fermented for four weeks without using any bacterial strains. Then we investigated fermentation characteristics including potential of hydrogen (pH), total sugar, microbial profiling and antioxidant compound contents such as total polyphenol and total flavonoid. The anti-obesity effects of AC and fAC were evaluated by using Oil Red O staining in 3T3-L1 adipocyte. Also anti-diabetic effects of them were evaluated by using 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) uptake in C2C12 skeletal muscle cell. Results: Both pH and total sugar of fAC were decreased significantly compared to unfermented AC. And the abundance of total bacteria and lactic acid bacteria increased during fermentation, especially Lactobacillus plantarum. Also fermentation of AC increased the content of total polyphenol. On the metabolic aspects, we found that AC and fAC suppressed fat accumulation. Conclusions: After four weeks of fermentation, AC increased concentrations of active compounds, altered microbial composition, and inhibited fat accumulation such as triglyceride. These results indicate that fermentation of AC might be a beneficial therapeutic approach for obesity.

미생물 살균제 Paenibacillus sp. AC-1 입제의 물리화학적 특성 (Physicochemical properties of granular formulation using Paenibacillus sp. AC-1 as a microbial fungicide)

  • 오경석;이영기;이재국;김진화
    • 농약과학회지
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    • 제9권3호
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    • pp.262-267
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    • 2005
  • 유기합성농약의 부작용을 최소화하고, 미생물 농약의 실용화를 목적으로 Paenibacillus sp. AC-1 건조 분말 그리고 여러 가지 보조제 및 증량제를 이용하여 입제를 제조하였으며, 이들 제제에 대한 물리화학적 특성을 연구하였다. 시제품은 Paenibacillus sp. AC-1 건조분말을 사용하여 고추역병 방제용 입제 4종을 제조하였다. 증량제 종류별 원제에 대한 영향은 talc가 가장 안정하였으며, 시제품 제조시 균주 생존성은 시제품 모두 제조 후에 안정하였다. Paenibacillus sp. AC-1 건조분말을 사용한 시제품의 물리화학적 특성 중 시제품 모두 입제의 품질규격에 적합하였다. Paenibacillus sp. AC-1 건조분말을 사용한 입제의 저장온도별 균주 안정성은 $4{\sim}50^{\circ}C$의 온도 범위에서 12주후까지도 안정하였다. 입제의 균 수중용출은 처리 7시간 후에 Paenibacillus sp. AC-1 균이 90% 이상 용출되었으며, 입자붕괴성은 처리 1일 후에 완전히 붕괴되었다. 이상의 결과를 종합할 때, Paenibacillus sp. AC-1를 이용한 고추역병 방제용 미생물 살균제의 실용화를 위한 제조처방은 원제로서 AC-1 건조분말 20%, 보조제로서 sodium polyacrylate 1.0%, 계면활성제로서 polycarboxylate를 주제로한 제제 7%, 증량제로서 나머지를 talc로 사용하는 것이 Paenibacillus sp. AC-1의 입제 제조에 최적 조건이었다.

Identification and Screening of Gene(s) Related to Susceptibility to Enterotoxigenic Escherichia coli F4ab/ac in Piglets

  • Li, Hejun;Li, Yuhua;Qiu, Xiaotian;Niu, Xiaoyan;Liu, Yang;Zhang, Qin
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권4호
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    • pp.489-493
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    • 2008
  • In 2004, Jorgensen and coworkers proposed the MUC4 gene as a candidate gene of enterotoxigenic Escherichia coli (ETEC) F4ab/ac receptor in piglets and a mutation of $G{\rightarrow}C$ in intron 7 of MUC4 was identified to be associated with the ETEC F4ab/ac adhesion phenotypes. In this study, we used 310 piglets of three breeds (Landrace, Large White and Chinese Songliao Black) to analyze the relationship between this mutation and the F4ab/ac adhesion phenotype. The results show that the genotypes at this site and the ETEC F4ab/ac adhesion phenotypes were not completely consistent, although they are very strongly associated. Among the individuals with genotype CC, which was identified as a resistant genotype to F4ab/ac adhesion, only 72.1% (124/172) were non-adhesive to ETEC F4ab and 77.9% (134/172) were non-adhesive to ETEC F4ac infections. This suggests that this mutation may not be the causative mutation for ETEC F4ab/ac adhesion, rather, the actual causative mutation may be in another gene closely linked to MUC4, or at aother site within the MUC4 gene. Our results also suggest that the receptors of F4ab and F4ac may be determined by two different but closely linked loci. In order to screen other genes related to F4ab/ac adhesion in piglets, the mRNA profiles from six full sib piglets, of which three were adhesive to ETEC F4ab/ac and three non-adhesive, were analyzed by suppression subtractive hybridization (SSH). One up-regulated gene, Ep-CAM, was selected for further analysis based on its role in the intestinal epithelial cells adhesion. Using real-time RT-PCR, we found that the Ep-CAM gene was significantly up-regulated in the piglets adhesive to F4ab/ac. It was mapped to SSC3q11-q14 by radiation hybrid mapping.

트위스트 피치를 고려한 Bi-2223 선재 제작과 AC 손실 측정 및 분석 (Fabrication, AC Loss Measurement and Analysis of Bi-2223 Conductors with Respect to Various Twist Pitch)

  • 장미혜;추용;임준형;주진호;고태국
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권11호
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    • pp.589-595
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    • 2000
  • In this papre, AC losses of Bi-2223 tapes with different twist pitch of superconducting core were fabricated, measured and analyzed. These samples produced by a powder-in-tube method are multi-filamentary tape with Ag matrix. Also, it's produced by non-twist and different twist pitch(8, 10, 13, 30, 50, 70 mn). The critical current measurement was carried out under the environment in Liquid nitrogen and in zero field by 4-probe method. And the AC loss measurement was carried out under the environment of applied time-varying transport current by transport method. From experiment, the critical current is larger non-twist than twisted filament. And, the AC loss by Norris equation is higher non-twisted tape than 13mm twisted tape. Also, it is confirmed that of AC loss of tape having non-twist pitch larger than those having differnet twist pitch.

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