• 제목/요약/키워드: pohang

검색결과 4,650건 처리시간 0.036초

X-ray Scattering Studies on the Structure of Porcine Pepsin in Various pH Solutions

  • Jin, Kyeong-Sik;Jin, Sang-Woo;Yoon, Jin-Hwan;Heo, Kyu-Young;Kim, Jae-Han;Kim, Hee-Soo;Ree, Moon-Hor
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.348-348
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    • 2006
  • In the present study, porcine pepsin in various pH conditions was investigated by small-angle X-ray scattering (SAXS) in order to detailed information on the structure and its variations with pH conditions. These analyses identified the structure of pepsin, and compared with that obtained by single crystallography. Moreover, this study found the structure' variations with changing pH conditions. All the results will be discussed with considering the conformational characteristics of pepsin in solution and further correlate to the biological and spectroscopic characteristics reported previously.

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200MW MODULATOR의 출력안정화를 위한 DE-Q'ING SYSTEM에 관한 연구 (Study on the De-Q'ing System for the Output Voltage Stabilization of a 200MW Modulator)

  • 손윤규;오종석;조무현;남궁원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1612-1614
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    • 1994
  • Modulators Installed in PLS(Pohang Light Source) Linac are composed of a DC high voltage section, a charging section and a discharging section. PFN is charged by a resonant charging mechanism, and discharged by a switching device through the primary of the pulse transformer connected to a load. Charged PFN voltage must be well regulated to obtain stable output pulse voltage at the load. For this purpose, DCHV is controlled by a SCR controller with feedback signal, and PFN voltage is regulated by a De-Q'ing circuit. The full power operation test shows the pulse voltage regulation within ${\pm}0.13%$ with SCR feedback control alone, and within ${\pm}0.08%$ together with De-Q'ing. This paper describes the design concept and operational characteristics of the De-Q'ing circuit.

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4세대 가속기 고정밀 고전압CCPS 개발 (Development of high-precision high-voltage CCPS)

  • 문용조;박성수;김상희;권세진;장성덕;이병준;이흥수;강흥식;황정연;김동수;이수영;신현석;장계용;노성채
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2012년도 전력전자학술대회 논문집
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    • pp.172-173
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    • 2012
  • 포항가속기 연구소에서는 4세대 가속기의 전자를 가속시키기 위해서 100ppm(0.01%) 이하의 고전압 안정도를 가진 200MW 펄스 모듈레이터가 요구된다. 그러므로 본 연구소에서는 고전압 안정도를 가진 고정밀 고전압 CCPS를 일반 CCPS와 병행하여 산업체와 함께 공동 개발을 진행하였다. 개발된 일반 CCPS의 사양은 50 kV, 30 kJ/sec, 600mA, 1000ppm이하이고, 고정밀 CCPS의 사양은 50 kV, 5 kJ/sec, 100mA, 100ppm이하이다. 본 논문에서는 CCPS의 개발 및 실제 모듈레이터에 설치하여 시험한 결과를 발표하고자 한다.

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Current Status of the Synchrotron Small-Angle X-ray Scattering Station BL4C1 at the Pohang Accelerator Laboratory

  • Jorg Bolze;Kim, Jehan;Huang, Jung-Yun;Seungyu Rah;Youn, Hwa-Shik;Lee, Byeongdu;Shin, Tae-Joo;Moonhor Ree
    • Macromolecular Research
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    • 제10권1호
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    • pp.2-12
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    • 2002
  • The small-angle X-ray scattering (SAXS) beamline BL4C1 at the 2.5 GeV storage ring of the Pohang Accelerator Laboratory (PAL) has been in its first you of operation since August 2000. During this first stage it could meet the basic requirements of the rapidly growing domestic SAXS user community, which has been carrying out measurements mainly on various polymer systems. The X-ray source is a bending magnet which produces white radiation with a critical energy of 5.5 keV. A synthetic double multilayer monochromator selects quasi-monochromatic radiation with a bandwidth of ca. 1.5%. This relatively low degree of monochromatization is sufficient for most SAXS measurements and allows a considerably higher flux at the sample as compared to monochromators using single crystals. Higher harmonics from the monochromator are rejected by reflection from a flat mirror, and a slit system is installed for collimation. A charge-coupled device (CCD) system, two one-dimensional photodiode arrays (PDA) and imaging plates (IP) are available its detectors. The overall performance of the beamline optics and of the detector systems has been checked using various standard samples. While the CCD and PDA detectors are well-suited for diffraction measurements, they give unsatisfactory data from weakly scattering samples, due to their high intrinsic noise. By using the IP system smooth scattering curves could be obtained in a wide dynamic range. In the second stage, stating from August 2001, the beamline will be upgraded with additional slits, focusing optics and gas-filled proportional detectors.

산업용 선형가속기 시스템 적용을 위한 30-MW 클라이스트론용 고 평균전력 펄스 트랜스포머의 설계 (Design of High Average Power Pulse Transformer for 30-MW Klystron of L-Band Linac Application)

  • 장성덕;손윤규;권세진;오종석;;;문성익;김상호;조무현;남궁원
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1550-1551
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    • 2006
  • An L-band linear accelerator system for e-beam sterilization is under design for bio-technology application. The klystron-modulator system as RF microwave source has an important role as major components to offer the system reliability for long time steady state operation. A PFN line type pulse generator with a peak power of 71.5-MW, $7{\mu}s$, 285 pps is required to drive a high-power klystron. The high power pulse transformer has a function of transferring pulse energy from a pulsed power source to a high power load. The pulse transformer producing a pulse with a peak voltage of 275 kV is required to produce 30-MW peak and 60 kW average RF output power at the frequency of 1.3-GHz. We have designed the high power pulse transformer with 1:13 step-up ratio. The peak and average power capability is 71.5-MW (275 kV, 260 A at load side with $7{\mu}s$ pulse width) and 130 kW, respectively. In this paper, we present a system overview and initial design results of the high power pulse transformer.

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Hypomyopathic Dermatomyositis 1예 (A Case of Hypomyopathic Dermatomyositis)

  • 김현태;이현욱;권병진;이지은;오동호;손민수;최정란
    • Journal of Yeungnam Medical Science
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    • 제28권2호
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    • pp.202-205
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    • 2011
  • Dermatomyositis is a rare and idiopathic inflammatory myopathy with a characteristic cutaneous manifestation. A 62-year-old female complained of polyarthralgia that lasted for many years. She was diagnosed with hypomyopathic dermatomyositis by the typical skin rash associated with dermatomyositis but without muscle involvement such as muscle weakness, elevated level of creatinine phosphokinase and aldolase. Her symptoms improved with treatment of hydroxychloroquine and prednisolone. We experienced a case of hypomyopathic dermatomyositis on 62-year-old female patient and report with review of literatures.

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Development of High-Performance Organic Field-Effect Transistors via Surface-Mediated Molecular Ordering

  • Cho, Kil-Won;Kim, Do-Hwan;Park, Yeong-Don;Jang, Yun-Seok;Hwang, Min-Kyu;Lee, Hwa-Sung;Lim, Jung-Ah
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.147-148
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    • 2005
  • We report on high-performance organic field-effect transistors by promoting surface-mediated two-dimensional molecular ordering in organic semiconductor. To achieve this goal, we have controlled the intermolecular interaction at the interface between organic semiconductor and the insulator substrate.

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