Cu 기판위에 성장한 MgO, MgAl₂O₄와 MgAl₂O₄/MgO 박막의 집속이온빔을 이용한 스퍼터링수율 측정과 이차전자방출계수 측정

정강원(K. W. Jung),이혜정(H. J. Lee),정원희(W. H. Jung),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.4

MgAl₂O₄ 막은 MgO 보호막 보다 단단하며 수분 흡착 오염문제에 상당히 강한 특성을 가진다. 본 연구에서 AC-PDP의 유전체보호막으로 사용되는 MgO 보호막의 특성을 개선하기 위해 MgAl₂O₄/MgO 이중층 보호막을 제작하여 특성을 조사하였다. 전자빔 증착기를 사용하여 Cu 기판에 MgO와 MgAl₂O₄을 각각 1000 Å 두께로 증착, MgAl₂O₄/MgO을 200/800 Å 두께로 적층 증착 후, 이온빔에 의한 충전현상을 제거하기 위해 Al을 1000 Å 두께로 증착하였다. 집속 이온빔(focused ion beam ; FIB)장치를 이용하여 10 ㎸에서 14 ㎸까지 이온빔 에너지에 따라 MgO는 0.364 ~ 0.449 값의 스퍼터링 수율에서 MgAl₂O₄/MgO을 적층함으로 24 ~ 30 % 낮아진 0.244 ~ 0.357 값의 스퍼터링 수율이 측정되었으며, MgAl₂O₄는 가장 낮은 0.088 ~ 0.109 값의 스퍼터링 수율이 측정되었다. g-집속이온빔(g-FIB)장치를 이용하여 Ne? 이온 에너지를 50 V에서 200 V까지 변화 시켜 MgAl₂O₄/MgO와 MgO는 0.09 ~ 0.12의 비슷한 이차전자방출 계수를 측정 하였다. AC-PDP셀의 72시간 열화실험 후 SEM 및 AFM으로 열화된 보호막의 표면을 관찰하여 기존의 단일 MgO 보호막과 MgAl₂O₄/MgO의 적층보호막의 열화특성을 살펴보았다. It is known that MgAl₂O₄ has higher resistance to moisture than MgO, in humid ambient MgO is chemically unstable. It reacts very easily with moisture in the air. In this study, the characteristic of MgAl₂O₄ and MgAl₂O₄/MgO layers as dielectric protection layers for AC-PDP (Plasma Display Panel) have been investigated and analysed in comparison for conventional MgO layers. MgO and MgAl₂O₄ films both with a thickness of 1000 Å and MgAl₂O₄/MgO film with a thickness of 200/800 Å were grown on the Cu substrates using the electron beam evaporation. 1000 Å thick aluminium layers were deposited on the protective layes in order to avoid the charging effect of Ga? ion beam while the focused ion beam(FIB)is being used. We obtained sputtering yieds for the MgO, MgAl₂O₄ and MgAl₂O₄/MgO films using the FIB system. MgAl₂O₄/MgO protective layers have been found th show 24 ~ 30% lower sputtering yield values from 0.244 up to 0.357 than MgO layers with the values from 0.364 up to 0.449 for irradiated Ga? ion beam with energies ranged from 10 ㎸ to 14 ㎸. And MgAl₂O₄ layers have been found to show lowest sputtering yield values from 0.88 up to 0.109. Secondary electron emission coefficient(g) using the γ-FIB. MgAl₂O₄/MgO and MgO have been found to have similar g values from 0.09 up to 0.12 for indicated Ne+ ion with energies ranged from 50 V to 200 V. Observed images for the surfaces of MgO and MgAl₂O₄/MgO protective layers, after discharge degradation process for 72 hours by SEM and AFM. It is found that MgAl₂O₄/MgO protective layer has superior hardness and degradation resistance properties to MgO protective layer.

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

CHF₃ / C₂F6 플라즈마에 의한 실리콘 표면 잔류막의 특성

권광호(K.-H. Kwon),박형호(H.-H. Park),이수민(S. M. Lee),강성준(S. J. Kang),권오준(O.-J. Kwon),김보우(B.W. Kim),성영권(Y.-K. Sung) 한국진공학회(ASCT) 1992 Applied Science and Convergence Technology Vol.1 No.1

실리콘을 CHF₃/C₂F_6 가스 플라즈마를 이용하여 식각하면 실리콘위에 탄소, 불소 및 산소로 이루어진 잔류막이 형성된다. 이 잔류막을 XPS로 분석한 결과 탄소는 C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, C-F₃ 결합을 하고 있으며, 불소는 F-Si, F-C 및 F-O 결합으로 이루어져 있음을 알았다. 한편 산소는 O-Si 및 O-F 결합으로, 실리콘은 Si-Si, Si-C 및 Si-O 결합상태를 나타낸다. 잔류막의 수직분포 연구를 통하여 Si-O 및 Si-C 결합이 탄소와 불소의 결합층 아래에 존재하고, 잔류막의 표면부에 F-O 결합이 분포함을 알았다. 또한 건식식각 변수가 잔류막 형성에 미치는 영향이 조사되었으며 CHF₃/C₂F_6 가스 유량비, RF power 벚 압력 등이 잔류막의 두께, 조성비 및 잔류막의 결합상태에 영향을 미침을 알 수 있었다. Si surfaces exposed to CHF₃/C₂F_6 gas plasmas in reactive ion etching (RIE) have been characterized by X-ray photoelectron spectroscopy (XPS). CHF₃/C₂F_6 gas plasma exposure of Si surface leads to the deposition of residual film containing carbon and fluorine. The narrow scan spectra of C 1s show various bonding states of carbon as C-Si, C-Si, C-C/H, C-CF_x(x≤3), C-F, C-F₂, and C-F₃. The chemical bonding states of fluorine are described with F-Si, F-C, and F-O. And the oxygen and silicon are also detected. The effects of parameters for reactive ion etching as CHF₃/C₂F_6 gas ratio, RF power, and pressure are investigated.

어육제품류의 기준규격 및 위해요소 중점관리방안에 관한 연구 : 어류 및 어육가공제품류의 위생적 품질지표로서의 부패성아민에 대하여 Putrefactive amines as a standpoint of sanitation of fish and fish products

이종옥,김명철,김인복,박혜경,김옥희,김연교,임성아,이근배,주현규 국립보건연구원 1994 국립보건원보 Vol.31 No.2

Dysregulation of upstream binding factor-1 acetylation at K352 is linked to impaired ribosomal DNA transcription in Huntington's disease

Lee, J,Hwang, Y J,Boo, J H,Han, D,Kwon, O K,Todorova, K,Kowall, N W,Kim, Y,Ryu, H Macmillan Publishers Limited 2011 Cell death and differentiation Vol.18 No.11

Huntington's disease (HD) is an autosomal-dominant neurological disorder caused by expanded CAG repeats in the Huntingtin (Htt) gene, but it is not known how this mutation causes neurodegeneration. Herein, we found that dysfunction of upstream binding factor-1 (UBF-1) is linked to reduced ribosomal DNA (rDNA) transcription in HD. We identified that UBF1 acetylation at Lys (K) 352 by CREB binding protein (CBP) is crucial for the transcriptional activity of rDNA. UBF1 mutation (K352A, K352Q, and K352R) decreased rDNA transcriptional activity. Moreover, both CBP–dHAT mutant and knockdown of CBP by siRNA reduced acetylation of UBF1 and resulted in the decreased transcription of rDNA into rRNA. ChIP analysis showed a significant reduction of UBF1 occupancy in the promoter of rDNA in STHdh<SUP>Q111</SUP> cell line model of HD. These results demonstrate that abnormal activity of UBF1 and its acetylation by CBP are linked to impaired rDNA transcription in HD. This novel mechanism suggests that modulation of UBF-mediated rDNA synthesis by CBP may be a therapeutic target for improving neuronal rDNA transcription in HD.

Temperature dependence of magnetoimpedance effect in amorphous CO?? Fe₄NiB?? Si? ribbon

Lee, Heebok,Cho, W.S,Kim, C.O,Kim, T.K,Kim, Y.K 公州大學校 基礎科學硏究所 1998 自然科學硏究 Vol.7 No.-

The temperature dependence of the magnetoimpedance (MI) effect is important both for scientific study and for thermal stability of MI sensors. We have performed the measurement of MI effect in amorphous Co66Fe4 NiB14Si15 (Metglas 2714A) ribbon from a cryogenic chamber where the temperature of the sample can vary from 10 to 300 K. The ac current was fixed at 10 mA for all measured frequencies ranging from 100 kHz to 10 MHz. The magncioimpedancc ratio (MIR) was revealed the drastic increment as a function of MIR(T)=MIR(O)exp(cT2), where c is a constant. The measured MIR values at room temperature are usually 2-3 times larger than the data measured at 10 K for all measured frequencies. However, the shapes of the MIR curves are remained. This result shows the potential application of the MI effect for a temperature sensor.

骨形成不全症의 1例

李連培,李容權,李基玉,安鍾瑾 대한소아과학회 1971 小兒科 Vol.14 No.8

터빈 로타 디스크의 초음파탐상을 위한 초음파탐촉자의 지향성 및 탐상범위

이종규,조경식,원순호,장홍근,이종오 韓國非破壞檢査學會 1998 한국비파괴검사학회지 Vol.18 No.3

터빈 디스크에서 발생하는 결함에 대한 초음파탐상기술을 확립하기 위하여 초음파탐촉자의 근/원거리 음장 및 지향성에 대하여 연구하였다. 영광원자력 LP터빈 No.6 디스크와 동일하게 대비시험편을 제작하였고 터빈로타 디스크의 총음파탐상에 사용된 5MHz PZT 압전탐촉자의 직경에 따른 근/원거리 음장 및 지향성을 계산하고 실험을 통하여 확인하였다. 쐐기와 디스크로 구성된 실험계에서 bore면에 깊이 2mm 및 4mm 인공결함을 지닌 시편과 직경이 0.5inch이고 중심 주파수 5MHz인 초음파탐촉자를 이용하여 계산 및 실험을 수행하였고 그 결과를 비교, 분석하였다. Keyway 영역에 발생한 결함의 탐상능력을 평가하기 위하여 내부의 53mm 및 75mm 지점에 초음파탐촉자를 두고서 45℃ 및 90˚경사각 초음파탐촉자를 설치한 경우를 가정하여 결함의 탐상영역을 결정하였다. Near/far field length and directivity of transducers were investigated for the improvement and evaluation of the detectability of flaws in a disc. The reference block is fabricated for the disc of stage 6 in Yonggwang unit 1. The near/far field and directivity of an ultrasonic transducer with the center frequency of 5 MHz were calculated for the inspection of the disc. These values showed good agreements with the experimental results. In the system composed of a wedge and a disc, those are evaluated theoretically and experimentally for the specimen with the artificial flaws of the size 2mm and 4mm and an ultrasonic transducer with the center frequency 5MHz and diameter 0.5inch. The detectability of keyway-flaw and detectable region for inspection were evaluated by using both tangential 45˚and 90˚ transducers located at the distance of 53mm and 75mm from the disc hub, respectively.

MgAl₂O₄ 스피넬 내화물의 합성과 응용

이윤복,권상오,장윤식,박상희,오기동 부산대학교 1995 生産技術硏究所論文集 Vol.48 No.-

MgO-Al₂O₃계에서 MgO첨가량에 따른 스피넬의 생성과 소결성을 조사하였다. 아울러 스피넬 내화물과 시멘트를 구성하는 주성분인 CaO의 반응성에 대하여 검토하였다. 가열된 시편의 상은 대부분의 스피넬, 페리클레이스 및 코런덤으로 동정되었고 과잉의 MgO를 함유한 시편의 경우 1750℃에서는 잔류 코런덤은 확인되지 않았다. MgO 함량이 감소함에 따라 스피넬내에 Al₂O₃의 고용에 기인된 스피넬의 생산량은 증가하는 경향을 나타내었다. 과잉의 MgO를 함유한 시편은 1600℃에서 치밀화가 촉진되어 1750℃, 5시간 유지한 시편의 경우 최종 소결밀도는 3.51g/㎤였다. 1750℃, 5시간 유지한 시편을 회전침식시험한 결과, 과잉의 MgO를 함유한 시편의 경우 침식깊이가 8.2mm, 침식면적이 225㎟로 다른 시편에 비교하여 가동면에서 CaO에 대한 침식저항성이 우수하였다. Effects of MgO content in spinel formation and sintering behavior of MgO-Al₂O₃ system were investigated. The reactivity of CaO in spinel refractories was also studied. From phase analyse, the refractories composed of mainaly two phase as like periclase and spinel, and residual corundom. However, the residual corundum was almost disappeared as it was fired at 1750℃ with excess of MgO. As the amount of MgO was reduced, the formation of spinel increased due to solid solubility of Al₂O₃ in spinel. The sample with excess of MgO markedly promoted the densification of spinel at 1600℃. The density of sample fired at 1750℃ for 5h was 3.51g/㎤. In rotary corrosion test, the sample with excess of MgO content, which had 8.2mm in the corrosion depth and 225㎟ in the corrosion area showed excellent corrosion resistance against the reactivity of CaO on the surface of spinel refractories.

Fragellation and Composite graft of skin and fat -8 Case report-

이영호,이종현,김동구,황오열,이원구,김성기 大韓成形外科學會 1981 Archives of Plastic Surgery Vol.8 No.2

No matter how various methods may be tried, for preventing contracture of flexor and extensor surface and padding the recipient bed which had been healed with split thickness skin graft or naturally, the results were not so acceptable unfourtunately. Of this procedure, preoperative beating and composite grafts of skin and fat is so unpopualr that we can not use easily. However, this method could satisfied us, we could use this method for covering of extensor and flexor surface of the neck, popliteal fossa, hand and corsum of foot although all cases were elective surgery. We had tried this method for eight cases of patient, and had good result. We thought this method had many difficult problem in skin biochemistry, physiolgy and unknown survival mechanism. But if further study and experimental work could support this operative method for transplanting fat and skin.