유량이 진공도 측정에 미치는 영향

유운종,금채,정광화,최석호 충남대학교 자연과학연구소 1989 忠南科學硏究誌 Vol.16 No.1

We extend the ranges of the vacuum standards to 10^-6 Pa by injecting the gas flow into the lower vacuum chamber of the orifice flow type vacuum standards system. The systematic error of the vacuum measurement has been reduced by measuring temperature accurately by reducing leak rate of the flowmeter and by attaching the ballast tank to flowmeter. We measure N_2, He and Ar gases for the sensitivity of nude ionization gauge for the check of the vacuum accuracy. The results are compared with the result of other research institute.

TFT LCD 제조용 대면적 Magnetron Sputtering 장치 설계와 Al 성장막 특성 조사

유운종(W. J. Yoo),현광수(K. S. Hyun),이재선(J. S. Lee),최원성(W. S. Choi),민병희(B. H. Min),연충규(C. K. Yon),표재확(J. H. Pyo),황기웅(K. W. Whang) 한국진공학회(ASCT) 1993 Applied Science and Convergence Technology Vol.2 No.4

TFT LCD(thin film transistor liquid crystal display) 금속화 박막제조를 위한 sputtering 장치 구성시에 대면적 기판에 박막의 균일도와 온도균일도, 진공용기내부에서의 sputtering 기체의 압력구배, 최저도달진공도, 기판 운송계의 이송의 안정성을 고려한다. 기판크기를 400×400 ㎜로 하여 sputtering source가 장착된 증착챔버, 기판을 증착전 RF 세척을 하고 온도를 200℃ 이상 상승을 위한 히탱챔버, 기판을 운송하는 운송계, (un)load lock 챔버로 구성하였다. 히터를 설계ㆍ제조하여 유리기판 위에서 온도균일도를 측정한 결과 250℃±5% 이내였고, 증착챔버의 최저도달진공도는 cryo 펌프로 24 시간 배기 후 1.8×10^(-7)torr였다. Sputtering source에 알루미늄 target를 장착시켜 알루미늄박막의 균일도, reflectivity, sheet resistance를 각각 측정하였다. Factors considered building the magnetron sputtering system for TFT LCD (thin film transistor liquid crystal display) metallization were thin film thickness uniformity, temperature uniformity and the pressure gradient of sputtering gas flow in vacuum chamber, base pressure, and the stability of the carrier moving. The system was consisted of a deposition chamber, a pre-heating chamber, a RF-precleaning chamber and a load/unload lock chamber. The system was designed to handle a substrate with dimension of 400 ×400 ㎜. The temperature uniformity of a heater table developed showed 250℃±5% accuracy on the substrate glass. A base pressure of 1.8×10^(-7)torr was obtained after 24 hours pumping with a cryo pump. After an aluminum target was installed in a sputtering source and the film was deposited on the glass, the uniformity, reflectivity and sheet resistance of the deposited film were measured.

10-¹¹ Torr의 초고진공 실현

유운종(U.J. Yoo),이재선(J.S. Lee),김명길(M.K. Kim),서성기(S.K. Suh) 한국진공학회(ASCT) 1992 Applied Science and Convergence Technology Vol.1 No.1

초고진공 시스템을 구성할 때 고려할 요소는 진공용기의 세척과 표면조도, 진공용기의 재질, 기타 방출 기체의 요인이다. 초고진공용기를 전해연마 처리하였으며, 처리한 진공용기의 표면조도를 표면조도기(surface profiler)로 측정하였다. 진공용기는 직경이 300 ㎜이고 높이는 720 ㎜로 하였다. 설치한 초냉각 펌프로 18시간 배기 후 2.9×10^(-10)Torr를 얻었으며, 계속해서 초고진공용기를 250℃에서 60시간 baking후 최저도달 압력이 3.08×10^(-11)torr에 도달하였다. 누드이온게이지를 이용하여 초고진공용기의 최저도달압력과 누출비를 측정하였다. The factors considered in building the ultrahigh vaccum system were the cleanliness and roughness of chamber surface, chamber material species and other source of outgassing. Electropolishing has been applied to a UHV chamber. The roughness of treated surface was measured by surface profiler. The dimension of the chamber were 300 ㎜ in inner diameter and 720 ㎜ in length. With a cryopump installed, a pressure of 2.9×10^(-10)torr was obtained after 18 hours of pumping. The base pressure of the UHV chamber was reached 3.08×10^(-11)torr after baking the chamber at 250℃ for 60 h. Two nude B-A ion gauge were employed to measure the base pressure and the leak up rate of the UHV chamber.

초거대 자기저항 La₁-xXx MnO₃ 화합물에서의 이중 교환 상호작용

유운종(Unjong Yu),이재동(J. D. Lee),민병일(B. I. Min) 한국자기학회 1997 韓國磁氣學會誌 Vol.7 No.1

Double exchange interaction leads to the ferromagnetism by the direct coupling between conduction electrons and magnetic ions. The most intriguing feature of double exchange is the explicit connection of the conductivity with the magnetism, which has drawn much interest in relation to the colossal magnetoresistance (CMR) recently observed in manganese oxide compounds. In this review, we explain the basic physics of double exchange and examine the classical discussions.

Magnetocapacitance in a Metal-Oxide-Metal Junction System

김규,민병일,유운종 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.4

We investigated the eects of the bandwidth change on the magnetocapacitance (MC) of a metal- oxide-metal junction. The bandwidth change is induced by an electron-electron interaction on the metallic side of the capacitance system. We employed a generalized Hamiltonian incorporating the on-site and the inter-site Coulomb interactions, the exchange interaction, and pair-hopping and obtained a quadratic dependence of the MC on the magnetic .eld. We also found that the eects of the bandwidth change could be substantial near the phase boundary between the paramagnetic and the ferromagnetic phases.民?;

우리나라에서 확보한 해양미생물과 미세조류에 대한 기초생리활성 연구

배승섭,권용민,정다운,유운종,조기철,조은서,정윤희,박윤경,안혜미,이대성,박진수,이재욱,오동찬,오기봉,조은지,박상익,전유진,이효근,김근용,남상집,최혁재,판철호,최그레이스 (사)한국해양생명과학회 2023 한국해양생명과학회지 Vol.8 No.2

우리나라 여러 해양환경 지역으로부터 확보한 370주의 해양세균, 균류, 미세조류로부터 기초생리활성(항산화, 항염, 항균, 항암, 항바이러스)을 조사하여 채집지, 분리원, 종(種) 수준에서의 활성결과를 비교하였다. 해양세균의 경우, 일반적으로 유용성이 많이 알려진 Streptomyces 속과 Bacillus 속에 속하는 균주들이 두드러진 강한 효능이 관찰되었고, 주로 해양퇴적물로부터 유용한 자원을 분리할 수 있었다. 해양균류와 미세조류의 경우에도 종 특이적으로 활성이 강하게 나타나는 결과를 확인할 수 있었고, 효능 특이적으로 활성을 보이는 결과도 얻을 수 있었다. 이러한 결과를 바탕으로 추후 특정질병에 선택적으로 효능을 보이는 화학물질 연구 또는 자원 기반 연구 수행 시 유용성을 전제로 한 자원 확보 전략 수립과 산업 활성화를 위한 전략소재로 우선적 접근이 용이할 수 있는 연구결과라 생각된다. 또한, 이들 결과를 해양바이오 뱅크를 통한 분양소재로 활용함으로써 학계, 산업계에서 활용하여 해양바이오산업 활성화에 좀 더 빠른 접근을 도울 수 있다고 생각한다. Basic bioactivities (antioxidant, anti-inflammatory, antibacterial, anticancer, antiviral) were investigated from 370 strains of marine bacteria, fungi, and microalgae obtained from various marine environmental regions in Korea, and the activity results were obtained at the collection site, isolation source, and species level was compared. In the case of marine bacteria, strains belonging to the generally useful genera Streptomyces and Bacillus were observed to have particularly strong efficacy and useful resources were mainly isolated from marine sediments. In the case of marine fungi and microalgae, results showing strong species-specific activity were confirmed, and results showing efficacy-specific activity were also obtained. Based on these results, it is a research result that can facilitate priority access as a strategic material for industrial revitalization and the establishment of a strategy to secure resources based on usefulness when conducting research on chemicals that are selectively effective against specific diseases or when conducting resource-based research. In addition, we believe that by using these results as material for sale through the Marine BioBank(MBB), academia and industry can use them to help accelerate the revitalization of the marine bio industry.

A novel methanotroph in the genus Methylomonas that contains a distinct clade of soluble methane monooxygenase

Ngoc-Loi Nguyen,유운종,양혜영,김종걸,정만영,박수제,노성운,이성근 한국미생물학회 2017 The journal of microbiology Vol.55 No.10

Aerobic methane oxidation is a key process in the global carbon cycle that acts as a major sink of methane. In this study, we describe a novel methanotroph designated EMGL16-1 that was isolated from a freshwater lake using the floating filter culture technique. Based on a phylogenetic analysis of 16S rRNA gene sequences, the isolate was found to be closely related to the genus Methylomonas in the family Methylococcaceae of the class Gammaproteobacteria with 94.2–97.4% 16S rRNA gene similarity to Methylomonas type strains. Comparison of chemotaxonomic and physiological properties further suggested that strain EMGL16-1 was taxonomically distinct from other species in the genus Methylomonas. The isolate was versatile in utilizing nitrogen sources such as molecular nitrogen, nitrate, nitrite, urea, and ammonium. The genes coding for subunit of the particulate form methane monooxygenase (pmoA), soluble methane monooxygenase (mmoX), and methanol dehydrogenase (mxaF) were detected in strain EMGL16-1. Phylogenetic analysis of mmoX indicated that mmoX of strain EMGL16-1 is distinct from those of other strains in the genus Methylomonas. This isolate probably represents a novel species in the genus. Our study provides new insights into the diversity of species in the genus Methylomonas and their environmental adaptations.

다용도 DC / RF 스퍼터링 시스템 설계

김명길(M. K. Kim),유운종(U. J. Yoo) 한국진공학회 1991 한국진공학회 학술발표회초록집 Vol.- No.-

Complete genome sequence of a zeaxanthin-producing marine bacterium, Fulvivirga lutea S481T

배승섭,정윤희,권용민,정다운,유운종,최그레이스 한국미생물학회 2023 미생물학회지 Vol.59 No.4

A zeaxanthin-producing marine bacterium, Fulvivirga lutea S481T was isolated from surface seawater. The complete genome of F. lutea S481T consists of 4,137,993 bp with a G + C content of 37.3 mol% and contains 3,616 protein-coding sequences, 37 tRNA genes, and 6 rRNA genes. Genome analysis revealed five genes involved in the zeaxanthin synthesis pathway. This genome information will provide fundamental knowledge for synthetic biology and metabolic engineering studies on zeaxanthin carotenoid synthesis.