• Title/Summary/Keyword: 이수체

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Photoisomerization of Cellulose Derivatives Obtained from Homogeneous System (균질계에서 얻은 셀룰로오스 유도체의 광이성질화 현상 연구)

  • No, Young-Ran;Park, Keun-Ho;Lee, Soo
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.4
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    • pp.273-278
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    • 2000
  • Cellulose tosylate(CT) was prepared by reaction of cellulose with p- toluenesulfonylchloride in DMAc/LiCl homogeneous system. In order to study a reversible photoisomerization of disperse red 1(DR-1) attached on natural polymer, cellulose tosylate containing DR-1(DR-1/CT adduct) was prepared at $110^{\circ}C$ in DMAc, and the changes of UV/Vis spectra of its solutions and thick film were investigated by alternate irradiation technique. Form the UV/Vis spectra of DR-1/CT adduct dissolved in cosolvents, such as DMAc, DMAc/THF, DMAc/benzene, and DMAc/chloroform and irradiated with 360 nm and 450 nm ligths, we found out changes of UV/Vis spectra were reversible in all solvents systems and we found out changes of UV/Vis spectra were reversible at thick film, also.

Detection of infectious pathogens in honeybee in Jeonbuk province, Korea (전북지역 꿀벌에서의 주요 병원체 검출)

  • Lee, Su-Ji;Yu, Cheong;Lee, Hee-Seon
    • Korean Journal of Veterinary Service
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    • v.39 no.3
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    • pp.137-140
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    • 2016
  • The correct and quick diagnosis can be minimized damage from honeybee diseases. This study was carried out to detect infectious pathogens in honeybee in Jeonbuk province. 183 samples were collected from 8 area of Jeonbuk beekeeping farms in 2015 and 10 of infectious pathogens were examined through PCR and RT-PCR. Among 183 samples, positive rates of each disease were as follows; BQCV 43.7%, SBV 24.6%, DWV 16.4%, SB 15.8%, CB 10.4%, Nosemosis 7.1%, AFB 6.6%, EFB 1.1%, CBPV 1.1%, ABPV 0.0%. Among 28 beekeeping farms, 19 farms (67.9%) were infected with a complex of two or more diseases. The highest frequency of complex infections was BQCV.

Development of a Low Energy Nitrogen Generator for Small or Mid - Sized Consumers (중소규모 질소사용처에서의 에너지절약형 질소공급장치 개발)

  • 이수언;박경석;박두선;손무룡;조순행;김종남;김한수
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1994.05a
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    • pp.91-97
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    • 1994
  • 본 연구의 목표는 제올라이트 분자체를 흡착제로 사용하여 99.99% 이상의 고순도 질소를 저렴하게 제조하는 PSA(Pressure Swing Adsorption)공정을 개발하고 상업화 설계 자료를 도출하는 것이다. PSA방법에 의한 질소제조는 기존의 심냉법보다 전력원단위가 낮을 뿐만 아니라 on-site방식으로 설치되어 운영되므로 수송경비를 절감할 수 있다. 이러한 장점 때문에 외국의 경우를 보면 PSA의 사용이 날로 증대되고 있다. 현재 국내에 설치중인 질소 PSA는 전량 수입에 의한 것이다. 따라서 본 연구에서 개발한 질소 PSA는 중소규모의 질소가스 사용처에 공급함으로써 에너지절감효과 뿐만아니라, 수입대체효과도 얻을 수 있다.

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A Study on the Standard Curriculum for Civil Engineering (토목공학을 위한 표준 교과과정에 관한 연구)

  • Choi, Se-Hyu;Noh, Tae-Song
    • Journal of Engineering Education Research
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    • v.14 no.4
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    • pp.78-82
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    • 2011
  • This study present the standard curriculum for civil engineering considering korean education environment. The flow charts of USA's 20 universities and Korea's 6 universities are investigated. The standard curriculum are proposed based on the civil engineering curriculum of USA and Korea though analyzing of subject division, major field, and major subject. The proposed standard curriculum is expected when used to improve korean universities curriculum.

Effects of Solid Lubricants on friction and wear behaviors of APSed Al2O3-ZrO2 Ceramic Composites Coating (대기플라즈마 용사법으로 제작된 알루미나-지르코니아 세라믹스 코팅층의 마찰마모거동에 고체윤활체의 효과)

  • Kim, Seong-Ho;Jeong, Sang-Hun;Lee, Sol-Bin;Lee, Su-Wan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2014.11a
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    • pp.296-297
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    • 2014
  • 고체윤활제는 고온부품의 응용에 매우 적합한 소재이다. 세라믹스를 기반으로 하는 고온저마찰소재는 우주항공, 발전시설 등과 같은 다양한 분야에서 매우 중요하다. 본 연구는 고온저마찰 소재를 가지는 자기윤활 $Al_2O_3-ZrO_2$ 세라믹 복합 코팅층의 마찰마모거동에 초점을 맞추고 있다. 이 자기윤활 $Al_2O_3-ZrO_2$ 세라믹 복합 코팅층은 대기플라즈마 용사법으로 제작하였으며, 비윤활상태에서 마찰마모거동을 조사하였다.

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Pulse-echo response of 1-3 type piezoelectric composite transducers for distance measurement (거리 측정용 1-3형 복합압전체 트랜스듀서의 펄스에코 응답 특성)

  • 최헌일;박정학;이수호;사공건
    • Electrical & Electronic Materials
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    • v.8 no.2
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    • pp.211-216
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    • 1995
  • In this study, the piezoelectric ceramics/polymer composite transducers with 1-3 connectivity have been studied. A piezoelectric ceramics PZT prepared by Wet-Dry Combination method was used as a filler in polymer matrix Eccogel. We've got the pulse-echo response for 1-3 type piezc-electric composite transducers in water. It was shown that the transmitting and receiving sensitivity of 1-3 type piezoelectric composite transducers could be improved in comparison with that- of solid PZT transducers. The reason is for that 1-3 type Piezoelectric composites have low dielectric constant and density. There was in a good agreement between the resonant frequencies calculated from one period and observed results on the Ultrasonic Transducer Analyzer. According to these results we could be figured out the distance in water by virture of the pulse-echo response.

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Microwave Absorption Properties of Ferrite/Rubber Composite Microwave Absorber mixed Ni-Zn ferrite and $Ni_2Y$ ferrite (Ni-Zn 페라이트와 $Ni_2Y$ 페라이트를 혼합한 페라이트/고무복합형 전파흡수체의 전파흡수특성)

  • Kim, H.G.;Kim, S.R.;Lee, S.H.;Cho, H.C.;SaGong, G.
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1355-1357
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    • 1997
  • In this study, the ferrite/rubber composite microwave absorbers mixed Ni-Zn ferrite and $Ni_2Y$ ferroxplana were prepared in order to control matching condion. The variation of the material constants($\dot{\varepsilon}$, $\dot{\mu}$) and microwave absorbing characteristics were investigated with various ferrite mixing ratio. The material constants of ferrite/rubber composite microwave absorber could be controlled by variation ferrite mixing radio. The matching frequency and thickness could be controlled with various ferrite mixing ratio.

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A Study on the Characteristics and Fabrication of $\textrm{Mg}_{2}\textrm{SiO}_{4}$ Phosphors ($\textrm{Mg}_{2}\textrm{SiO}_{4}$ 열형광체의 제작 및 특성에 관한 연구)

  • Kim, Yeong-Guk;Son, In-Ho;Chae, Geon-Sik;Lee, Su-Dae;Seol, Gyeong-Sik;No, Gyeong-Seok;Song, Jae-Heung;Lee, Sang-Yun;Do, Si-Heung
    • Korean Journal of Materials Research
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    • v.8 no.2
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    • pp.179-185
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    • 1998
  • Mg2SiO4 열형광체에 란탄계 금속 Tb, Tm, La, Ho, Dy 및 Nd를 활성체로 첨가하여 열형광체를 제작했으며, Peak shape법으로 활성화에너지를 계산한 결과 0.53-1.77eV였으며, 발광과정의 차수는 전부 2차였다. 저 에너지 X-선에 대해 매우 높은 감도를 나타내었으므로 방사선 센서 소자로 개발하기 위한 기초 자료가 될 것이다.

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Pulse-echo Response of Piezoceramic-Polymer 1-3 Type Composite Transducers (압전 세라믹-고분자 1-3형 복합 압전체 트랜스듀서의 펄스에코 특성)

  • Choi, H.I.;Park, J.H.;Lee, S.H.;SaGong, G.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1403-1405
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    • 1994
  • In this study, the piezoelectric transducers with 1-3 connectivity have maded. A piezoelectric ceramic PZT prepared by Wet-Dry Combination method is used as a filler in Eccogel polymer matrix. The pulse-echo response for 1-3 type composite transducers were carried out in water. It was observed that the transmitting and receiving sensitivity of 1-3 type composite transducers were improved in comparison with that or solid PZT transducer. The reason is for that 1-3 composites have a hish piezoelectric voltage coefficients, The period of pulse-echo response for the transducer is in a good agreement with the resonant frequency of self-maded composite transducer.

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A Study on the educational aptitude and examination Web personality tests and the system (교직 적성 및 인성 검사 웹 검정 시스템 연구)

  • Park, Ki-Hong;Jang, Hae-Sook
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2014.07a
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    • pp.381-382
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    • 2014
  • 교원의 핵심 역량 중 지식 역량이나 수행 역량 등은 교직과정 이수 결과의 확인이나 지필 시험 또는 실기 시연 등을 통해 확인 또는 평가할 수 있다. 그러나 태도 역량이나 전문성 개발역량의 일부 요소들은 별도의 도구나 평가로 심사해야 된다. 전문성 개발 역량 가운데 자기반성 노력, 지속적 학습 노력, 교육 공동체 간 의사소통 및 협력 등의 요소들은 기존의 평가 방식으로 파악하기 어렵다. 따라서 교원의 핵심 역량을 평가하기 위해서는 교직 적성 및 인성 검사와 같은 별도의 도구가 필요하다. 본 논문은 교원자격을 강화하기 위한 교직 적성 및 인성 검사를 효율적으로 실시하기 위한 온라인 웹 검정 시스템을 설계하고자 한다.

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