• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1998년도 춘계학술대회 및 발표대회 강연 및 발표논문 초록집
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• pp.6-6
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• 1998

In 1957, the first magnetic disk drive compatible with a movable head was introduced as an external file memory device for computer system. Since then, magnetic disks have been improved by increasing the recording density, which has brought about the development of a high performance thin film magnetic head. The thin film magnetic head has a magnetic circuit on a ceramic substrate using IC technology. The physical property of the substrate material is very important because it influences the tribology of head/disk interface and also manufacturing process of the head. $Al_{2}O_{3}$-TiC ceramics, so called ALTIC, is known to be one of the best substrate materials which satisfies this property requirement. Even though the head is not in direct contact with the disk, frequent instantaneous contacts are unavoidable due to its high rotating speed and the close gap between them. This may cause damage in the magnetic recording media and, thus, it is very important that the magnetic head has a good wear resistance. $Al_{2}O_{3}$-TiC ceramics has an excellent tribological property in head/disk interface. Manufacturing process of thin film head is similar to that of IC, which requires extremely smooth and flat surface of the substrate. The substrate must be readily sliced into the heads without chipping. $Al_{2}O_{3}$-TiC ceramics has excellent machineability and mechanical properties. $Al_{2}O_{3}$-TiC ceramics was first developed at Nippon Tungsten Co. as cutting tool materials in 1968, which was further developed to be used as the substrate materials for thin film head in collaboration with Sumitomo Special Metals Co., Ltd. in 1981. Today, we supply more than 60% of the substrates for thin film head market in the world. In this paper, we would like to present the sintering process of $Al_{2}O_{3}$-TiC ceramics and its property in detail.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.988-990
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• 2003

A plastic substrate for flexible display is developed. The developed PES film has good resistance to heat, low intrinsic birefringence, and mechanical stability. The gas barrier property in the substrate is improved through depositing organic and inorganic multi layer on plastic film by PVD and CVD process.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.584-589
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• 2001

Diamond thin films were synthesized on WC-Co substrate by RF PACVD(radio frequency plasma-assisted chemical vapor deposition) technique with H$_2$-CH$_4$-O$_2$ gas mixture. WC-Co substrate was pre-treated in HNO$_3$solution, scratched with 3$\mu\textrm{m}$ diamond paste and exposed in the O$_2$ plasma before deposition. The diamond thin film prepared at 11% oxygen concentration showed the best quality of good adhesion and wear resistance at various oxygen concentration with the fixed 5% CH$_4$ concentration.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.597-605
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• 2018

Acyl-CoA oxidases (ACOXs) play important roles in lipid metabolism, including peroxisomal fatty acid ${\beta}$-oxidation by the conversion of acyl-CoAs to 2-trans-enoyl-CoAs. The yeast Yarrowia lipolytica can utilize fatty acids as a carbon source and thus has extensive biotechnological applications. The crystal structure of ACOX3 from Y. lipolytica (YlACOX3) was determined at a resolution of $2.5{\AA}$. It contained two molecules per asymmetric unit, and the monomeric structure was folded into four domains; $N{\alpha}$, $N{\beta}$, $C{\alpha}1$, and $C{\alpha}2$ domains. The cofactor flavin adenine dinucleotide was bound in the dimer interface. The substrate-binding pocket was located near the cofactor, and formed at the interface between the $N{\alpha}$, $N{\beta}$, and $C{\alpha}1$ domains. Comparisons with other ACOX structures provided structural insights into how YlACOX has a substrate preference for short-chain acyl-CoA. In addition, the structure of YlACOX3 was compared with those of medium- and long-chain ACOXs, and the structural basis for their differences in substrate specificity was discussed.

• 한국육종학회지
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• 제40권4호
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• pp.422-429
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• 2008

본 실험에서 Lilium longiflorum과 11품종에 대한 biochemical, enzymology 등의 분석방법을 적용하여, 화색생합성조절유전자 chalcone synthase(CHS), flavanone 3-hydroxylase(FHT)의 활성을 분석한 결과는 다음과 같다. 1. Flavonoid의 기본골격형성을 위한 첫 효소인 CHS가 malonyl-CoA와 p-coumaroyl-CoA 기질을 촉매하여 naringenin(NAR) 산물을 생성하였고, caffeoyl-CoA와 p-coumaroyl-CoA 기질에는 eridictiol(ERI)를 생성하지 않아, 백합의 CHS는 기질특이성을 나타냈다. 2. L. longiflorum에서 FHT 효소는 NAR를 기질로써 사용하여, dihydrokaempferol(DHK) 산물을 생성하였고, 그 외 11백합품종에서도 FHT 효소의 뚜렷한 활성이 확인되었다.

• 한국재료학회지
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• 제10권11호
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• pp.738-741
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• 2000

사이클로펜타디에닐 디카보닐 코발트 (Co(η(sup)5-C(sub)5H(sub)5) ($CO_2$)의 반응성 화학 기상 증착법에 의해 $600^{\circ}C$ 근처의기판온도에서 (100)Si 기판 위에 균일한 에피택셜 CoSi2 층이 후열처리를 거치지 않고 직접 성장되었다. (100) Si 기판 위에서 에피택셜 CoSi(sub)2 층의 성장 속도론을 $575^{\circ}C$에서 $650^{\circ}C$의 온도 구간에서 조사하였다. 증착 초기 단계에서 판(plate)모양의 CoSi(sub)2 스차이크가 쌍정의 구조를 가지고 (100) Si 기판에서 <111> 방향을 따라서 불연속적으로 핵생성되었다. {111}과 (100)면을 가진 불연속의 CoSi(sub)2 판은 (100) Si 위에서 평평한 계면으로 이루어진 에피택셜 층으로 성장했다. (100) Si 위에서 에피택셜 CoSi(sub)2 층을 통한 Co의 확산에 의해 제어되는 것으로 나타났다.

• 한국표면공학회지
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• 제54권6호
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• pp.307-314
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• 2021

Diamond-like carbon (DLC) is difficult to achieve sufficient adhesion because of weak bonding between DLC film and the substrate. The purpose of this study is to improve the adhesion between substrate and DLC film. DLC film was deposited on AISI H13 using linear ion source. To improve adhesion, the substrate was treated by dual post plasma nitriding. In order to define the mechanism of the improvement in adhesive strength, the gradient layer between substrate and DLC film was analyzed by Glow Discharge Spectrometer (GDS) and Scanning Electron Microscope (SEM). The microstructure of the DLC film was analyzed using a micro Raman spectrometer. Mechanical properties were measured by nano-indentation, micro vickers hardness tester and tribology tester. The characteristic of adhesion was observed by scratch test. The adhesion of the DLC film was enhanced by active screen plasma nitriding layer.

• 한국전자파학회논문지
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• 제19권2호
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• pp.257-262
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• 2008

본 논문에서는 열전도도가 우수한 AIN 기판에 $CO_2$ Laser 장비 를 이용하여 Thru-hole과 scribing line을 형성하기 위해 $CO_2$ laser의 파라미터(촛점 거리, 공기량, 레이저 빔 시간, 펄스 개수)를 실험하고, 자체 정렬 마스킹 기법을 이용한 5 um 두께의 Cu 도금으로 AIN 기판에 전송 선로와 나선형 평면 인덕터를 제작하였다. AIN 기판에서의 마이크로스트립 라인의 전송 손실은 10 GHz에서 0.1 dB/mm, 6 nH 나선형 평면 인덕터는 1 GHz에서 56의 품질 계수를 얻었고, 이를 통해 열전도도가 우수한 AIN 기판의 고전력 RF 응용이 가능할 것으로 기대한다.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.949-954
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• 2022

The lipolytic yeast Candida aaseri SH14 contains three Acyl-CoA oxidases (ACOXs) which are encoded by the CaAOX2, CaAOX4, and CaAOX5 genes and catalyze the first reaction in the β-oxidation of fatty acids. Here, the respective functions of the three CaAOX isozymes were studied by growth analysis of mutant strains constructed by a combination of three CaAOX mutations in minimal medium containing fatty acid as the sole carbon source. Substrate specificity of the CaAOX isozymes was analyzed using recombinant C. aaseri SH14 strains overexpressing the respective genes. CaAOX2 isozyme showed substrate specificity toward short- and medium-chain fatty acids (C6-C12), while CaAOX5 isozyme preferred long-chain fatty acid longer than C12. CaAOX4 isozyme revealed a preference for a broad substrate spectrum from C6-C16. Although the substrate specificity of CaAOX2 and CaAOX5 covers medium- and long-chain fatty acids, these two isozymes were insufficient for complete β-oxidation of long-chain fatty acids, and therefore CaAOX4 was indispensable.

• ETRI Journal
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• 제32권2호
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• pp.195-203
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• 2010

A new vertical transition between a substrate integrated waveguide in a low-temperature co-fired ceramic substrate and an air-filled standard waveguide is proposed in this paper. A rectangular cavity resonator with closely spaced metallic vias is designed to connect the substrate integrated waveguide to the standard air-filled waveguide. Physical characteristics of an air-filled WR-22 to WR-22 transition are compared with those of the proposed transition. Simulation and experiment demonstrate that the proposed transition shows a -1.3 dB insertion loss and 6.2 GHz bandwidth with a 10 dB return loss for the back-to-back module. A 40 GHz low-temperature co-fired ceramic module with the proposed vertical transition is also implemented. The implemented module is very compact, measuring 57 mm ${\times}$ 28 mm ${\times}$ 3.3 mm.