Influence of Al Interlayer on Characteristic of Zn Alloy Thin Films

Myeong Hoon Lee,Il Yong Bae,Jae In Jeong,Yeong Jin Kwak,Tae Yeop Kim 한국표면공학회 2008 한국표면공학회 학술발표회 초록집 Vol.2008 No.-

Effects of Dopamine.HCI on Structural Parameters of Bovine Brain Membranes

Bae, Moon-Kyoung,Huh, Min-Hoi,Lee, Seung-Woo,Kang, Hyun-Gu,Pyun, Jae-Ho,Kwak, Myeong-Hee,Jang, Hye-Ock,Yun, Il The Pharmaceutical Society of Korea 2004 Archives of Pharmacal Research Vol.27 No.6

Fluorescence probes located in different membrane regions were used to evaluate the effect of dopamine$.$HCI on the structural parameters (transbilayer lateral mobility, annular lipid fluidity, protein distribution, and thickness of the lipid bilayer) of synaptosomal plasma membrane vesicles (SPMV), which were obtained from the bovine cerebral cortex. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) by trinitrophenyl groups, and radiationless energy transfer from the tryptophan of membrane pro-teins to Py-3-Py and energy transfer from Py-3-Py monomers to 1-anilinonaphthalene-8-sulfonic acid (ANS) was also utilized. Dopamine$.$HCI increased both the bulk lateral mobility and annular lipid fluidity, and it had a greater fluidizing effect on the inner monolayer than on the outer monolayer. Furthermore, the drug had a clustering effect on membrane proteins.

Optical and microstructural properties of InGaN/GaN multiple quantum wells with embedded graphene coating

Bae, Goh-Myeong,Choi, Jae-Kyung,Cho, Chu-Young,Lee, Jong-Hwa,Kwak, Jinsung,Na, Hyunseok,Park, Kyung-Ho,Park, Kibog,Kwon, Soon-Yong Elsevier 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.713 No.-

<P><B>Abstract</B></P> <P>We investigate the effects of embedded graphene coating on the optical and microstructural properties of ultrathin InGaN/GaN multiple quantum wells (MQWs). The InGaN/GaN MQWs grown on graphene-buffered GaN templates displayed enhanced internal quantum efficiency compared to conventional ones and showed the internal electric field effect-free characteristic, desirable for general lighting applications. These phenomena were attributed to the enhancement of potential fluctuation with increased indium content and negligible piezoelectric polarization in ultrathin InGaN QWs, respectively. It was found that the atomically rough surface of GaN induced by embedded graphene coating efficiently relieved the biaxial compressive strain in the ultrathin InGaN/GaN QWs and enhanced the In incorporation efficiency during the InGaN growth, suggesting the potential use of atomic-thick carbon layer in niche optoelectronic applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> InGaN/GaN multiple quantum wells (MQWs) were grown on a graphene-buffered GaN template. </LI> <LI> The MQWs show improved optical properties compared to conventional ones. </LI> <LI> The mechanism relies on the strain relaxation in InGaN QWs by graphene insertion. </LI> <LI> The graphene coating layer can be used for the niche optoelectronic applications. </LI> </UL> </P>

MCP 를 위한 Cu/Sn/Cu 범프의 계면미세구조가 신뢰성에 미치는 영향

정명혁(Myeong-Hyeok Jeong),김재원(Jae-Won Kim),곽병현(Byung-Hyun Kwak),박영배(Young-Bae Park) 한국정밀공학회 2010 한국정밀공학회 학술발표대회 논문집 Vol.2010 No.5월

안전장구시험장치의 특성에 관한 연구

최명호(Myeong-Ho Choi),지용헌(Yong-heon Ji),곽상영(Sang-young Kwak),이순배(Soon-Bae Lee),김래진(Rea-Jin Kim),서삼문(Sam-Moon Suh),안희석(Heau-Seak An) 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

본 연구는 안전장구 시험장치의 특성에 관한 것으로 기존 수동으로 시험하던 장치를 크게 개선하여 안전하고 편리하고 쉬운 시험이 가능하도록 원터치 형태로 자동시험이 가능하며 기존 구형장치를 대체하는 디지털화된 신개념의 “안전장구 시험장치”를 제시한다.

터널 콘크리트 구조물의 보수를 위한 무기게 균열주입기술의 표준화 연구

배기선 ( Bae-kee-sun ),곽수정 ( Kwak Su-jung ),백종명 ( Ba다 Jong-myeong ) 한국구조물진단유지관리공학회 2006 한국구조물진단유지관리공학회 논문집 Vol.10 No.6

본 논문은 터널 콘크리트 구조물의 보수를 위한 무기계 균열주입기술의 표준화에 관한 연구이다. 본 연구를 위하여 균열보수공사가 필요한 터널 라이닝 및 박스 구조물을 선정하여, 균열폭에 따른 주입량, 주입시간 및 주입압력, 주입압력과 주입시간, 구조물 규모에 따른 주입량, 구조물별 균열 위치에 따른 주입량, 균열폭 및 구조물 두께와 주입시간의 관계에 관하여, 현장 조사와 시험평가를 수행하여 구조물의 종류 및 균열의 크기에 따른 균열보수재의 주입압력, 주입량 및 주입시간 등을 명확히 파악하였다. This study is to establish a standardization of injection system by inorganic material for crack repair of tunnel concrete structures. For this various surveys and experiments were carried out as followed. The first we surveyed capability of injection and crack pattern of concrete structures in site. and second we analyzed the relationship between crack width and volume of injection, and decided pressure and volume of injection. Finally we evaluated the relationship between crack width and volume of injection with kind of concrete structures, and between required time for injection and crack width with thickness of structure. From these surveys and experiments, we cleared the relationship between crack patterns and injection technologies such as volume, pressure of injection and required time for injection with kind of structure.

가토 경골에 식립된 Ca-P 박막코팅 임프란트의 뒤틀림 제거력 및 조직형태학적 평가

곽명배,이청희,Kwak Myeong-Bae,Lee Cheong-Hee 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.5

Statement of problem: Surface texture of the implant is one of the important factors of the implant success, especially in the immediate implant loading. Many methods of the surface treatment of implant have developed and introduced. Purpose : This study was to evaluate the effects of the Ca-P coating implant crystallized the hydroxyapatite on the surface by the removal torque test and the histomorphometric analysis in vivo. Material and methods: 135 screw type implants, 4.0mm in length and 3.75mm in diameter were used in this study. Implants were divided into 3 groups and treated in the different mothods. Group I was not treated, Group II was treated in the SLA method, and Group III was treated in the Ca-P coating with the anodizing method and the hydroxyapatite was crystallized on the surface with the hydrothermal treatment. Firstly, the surface roughness of each group was measured, 45 rabbits were used in this experiment. Two implants were inserted on right tibial metaphysis and one implant was inserted on left side with the alternating order. After the healing periods of 3, 5, and 12 weeks, the rabbits were sacrificed to evaluate the osseointergration by the removal torque test and the histomorphometric analysis. Results : 1. In the analysis for the surface roughness, Group II showed the highest roughness. And Group III showed higher secondly. There was a significant difference one another statistically 2. In the removal torque test, Group III and II were significantly higher than Group I. There was no statistical difference between Group III and Group II. 3. For all Groups, the removal torque values at 12th week were significantly higher than at 3rd and 5th week. 4. In histomorphometric analysis, the bone implant contact rates of Group III and II were higher than that of Group I at 3rd and 5th week. There was a significant difference at 5th week. 5. In histomorphometric analysis, the bone implant contact rate of Group III and II increased from 3rd week to 5th week, but decreased at 12th week. In Group I, the contact rate at 12th week was significantly higher than at 3rd week and 5th week.

3차원 적층 패키지를 위한 Cu/thin Sn/Cu 범프구조의 금속간화합물 성장거동분석

박영배 ( Young Bae Park ),김재원 ( Jae Won Kim ),김병준 ( Byoung Joon Kim ),김재동 ( Jae Dong Kim ),주영창 ( Young Chang Joo ),이기욱 ( Ki Wook Lee ),정명혁 ( Myeong Hyeok Jeong ),곽병현 ( Byung Hyun Kwak ) 대한금속재료학회(구 대한금속학회) 2011 대한금속·재료학회지 Vol.49 No.2

Isothermal annealing and electromigration tests were performed at 125℃ and 125℃, 3.6×104 A/cm2 conditions, respectively, in order to compare the growth kinetics of the intermetallic compound (IMC) in the Cu/thin Sn/Cu bump. Cu6Sn5 and Cu3Sn formed at the Cu/thin Sn/Cu interfaces where most of the Sn phase transformed into the Cu6Sn5 phase. Only a few regions of Sn were not consumed and trapped between the transformed regions. The limited supply of Sn atoms and the continued proliferation of Cu atoms enhanced the formation of the Cu3Sn phase at the Cu pillar/Cu6Sn5 interface. The IMC thickness increased linearly with the square root of annealing time, and increased linearly with the current stressing time, which means that the current stressing accelerated the interfacial reaction. Abrupt changes in the IMC growth velocities at a specific testing time were closely related to the phase transition from Cu6Sn5 to Cu3Sn phases after complete consumption of the remaining Sn phase due to the limited amount of the Sn phase in the Cu/thin Sn/Cu bump, which implies that the relative thickness ratios of Cu and Sn significantly affect Cu-Sn IMC growth kinetics.

임플란트 식립 초기 의원성 동요가 최종 골결합에 미치는 영향

곽명배,조진현,이두형,이청희,Kwak, Myeong-Bae,Cho, Jin-Hyun,Lee, Du-Heong,Lee, Cheong-Hee 대한치과보철학회 2014 대한치과보철학회지 Vol.52 No.2

연구 목적: 이 연구의 목적은 임플란트 식립 초기 수회의 의원성 동요가 최종 골결합에 미치는 영향을 확인하는 것이다. 연구 재료 및 방법: 순수한 티타늄(Grade IV) 으로 직경 3.75 mm, 길이 8 mm의 실험용 임플란트를 제작한 후, 하방 4 mm에 RBM 표면처리($MegaGen^{(R)}$: Ca-P)를 하였다. 임플란트의 하부만 골에 식립되었으며 비침하시켰다. 수술은 3.5 kg이상의 토끼의 좌우 경골의 단층 치밀골에 각각 2개씩 130개를 통상적인 방법으로 식립하였다(Female, New Zealand White). 비틀림 제거 간격에 따라, 다음과 같은 13개의 군으로 나누었다; Group I (1일), Group II (1일 + 2일), Group III (1일 + 2일 + 3일), Group IV (1일 + 2일 + 3일 + 4일), Group V (2일), Group VI (2일 + 4일), Group VII (2일 + 4일 + 6일), Group VIII (2일 + 4일 + 6일 + 8일), Group IX (4일), Group X (4일 + 7일), Group XI (4일 + 7일 + 10일), Group XII (4일 + 7일 + 10일 + 14일), 그리고 대조군. 대조군은 식립 후 8주의 치유기간을 준 후 최종 비틀림 제거력을 측정하였다(Mark-10, USA). 실험군은 각각의 조건에 맞추어 1회에서 4회에 걸쳐 비틀림 제거력을 측정하였다. 비틀림 제거력을 측정한 이후에 대체적으로 임플란트를 측정 전의 위치로 재위치시켰다. 모든 실험군에서 임플란트 식립 후 8주간의 치유기간을 준 다음 최종 비틀림 제거력을 측정하여 대조군, 각 실험군의 1, 2, 3, 4번째 비틀림 제거력과 비교하였다. 결과: 실험군 간에 최종 비틀림 제거력을 비교한 결과에서, XII군을 제외한 실험군의 비틀림 제거력은 대조군과 유의할만한 차이를 보이지는 않았다. 그리고 실험 I군과 II군의 값은 VI, VIII, X, XI, XII군의 값보다 유의하게 높게 나타났다. 그리고 III, IV, V군은 XI, XII군의 값보다 유의하게 높게 나타났다. 각 실험군간 비틀림 제거력 비교에서, 최종 비틀림 제거력은 VIII, X, XI, XII군을 제외한 모든 군에서 높게 나타났다. 결론: 충분한 치유기간이 주어진다면, 토끼에게 임플란트 식립 후 매우 이른 초기에 지대주에 가해지는 약간의 동요는 임플란트 골결합에 영향을 미치지 않았다. Purpose: The aim of present investigation was to find out the influence of several times iatrogenic mobilization in the initial stage of implant installation on bone-implant osteointegration. Materials and methods: The experimental implants (3.75 mm in diameter, 8.0 mm in length) were made of commercially pure (Grade IV) titanium, and were treated with RBM ($MegaGen^{(R)}$: Ca-P) on lower 4.0 mm part. Only lower part of implant was inserted to bone and the implants were nonsubmerged. The 130 implants (two in each tibia) were inserted into the monocortical tibias of 33 rabbits which each weighed more than 3.5 kg (Female, New Zealand White). According to the removal torque interval, the groups were divided into 13 groups, group I (1 day), group II (1 day + 2 days), group III (1 day + 2 days + 3 days), group IV (1 day + 2 days + 3 days + 4 days), group V (2 days), group VI (2 days + 4 days), group VII (2 days + 4 days + 6 days), group VIII (2 days + 4 days + 6 days + 8 days), group IX (4 days), group X (4 days + 7 days), group XI (4 days + 7 days + 10 days), group XII (4 days + 7 days + 10 days + 14 days) and control group. In the control group, the removal torque was measured at 8 weeks with a digital torque gauge (Mark-10, USA). In the experimental groups, the removal torque was given once, twice, three times or four times by experiment design before the final removal torque and the value was measured each time. The implants were then screwed back to their original positions. All the experimental groups were given a final healing time of 8 weeks after placement, in which values were compared with the control groups and the 1st, 2nd, 3rd or 4th removal torque values in each experimental group. Results: In comparison of the final removal torque tests among experimental groups, the removal torque value of experimental groups except group XII were not statistically different that of control group. And the values of group I and II were significantly higher than the values of group VI, VIII, X, XI, and XII. In addition, the values of group III, IV, and V were significantly higher than group XI and XII. In comparison of the removal torque in the each experimental group, the final removal torque were significantly higher in all groups except group VIII, X, XI, and XII. Conclusion: If sufficient healing time was allowed, a few mobilization of fixture at the very early stage after the implant placement in the rabbits didn't interrupt the final bone to implant osseointegration.

3차원 칩 적층을 위한 Cu pillar/Sn-3.5Ag 미세범프 접합부의 금속간화합물 성장거동에 따른 전단강도 평가

곽병현 ( Byung Hyun Kwak ),정명혁 ( Myeong Hyeok Jeong ),박영배 ( Young Bae Park ) 대한금속재료학회(구 대한금속학회) 2012 대한금속·재료학회지 Vol.50 No.10

The effect of thermal annealing on the in-situ growth characteristics of intermetallics (IMCs) and the mechanical strength of Cu pillar/Sn-3.5Ag microbumps are systematically investigated. The Cu6Sn5 phase formed at the Cu/solder interface right after bonding and grew with increased annealing time, while the Cu3Sn phase formed at the Cu/Cu6Sn5 interface and grew with increased annealing time. IMC growth followed a linear relationship with the square root of the annealing time due to a diffusion-controlled mechanism. The shear strength measured by the die shear test monotonically increased with annealing time. It then changed the slope with further annealing, which correlated with the change in fracture modes from ductile to brittle at a critical transition time. This is ascribed not only to the increasing thickness of brittle IMCs but also to the decreasing thickness of the solder, as there exists a critical annealing time for a fracture mode transition in our thin solder-capped Cu pillar microbump structures.