In situ 고상 에피택시 방법에 의한 CoSi₂/Si(111)구조의 형성

이정주,강민성,김현수,최치규,이운환,이종덕,이영백,김건호,이정용 濟州大學校 基礎科學硏究所 1996 基礎科學硏究 Vol.9 No.2

초고진공에서 공상에피택시(solid-phase epiyaxy, SPE) 방법으로 CoSi₂를 Si(111)기판 위에 에피택시 성장시켰다. 2MeV⁴He++ ion후방산란 분광기와 사중결정 x-선 회절기 및 고분해 투과전자 현미경을 이용하여 성장된 CoSi₂의 상과 조성, 결정성, 그리고 계면의 미시구조를 조사하였다. 초고진공상태의 실온에서 Si(111)-7X7기판에 Co를 약 20 ~50 ?? 중착한 후 SPE에 의하여 실리사이드를 형성시키는 경우 600℃에서는 B-형의 CoSi₂가, 그리고 700℃에서는 A형의 CoSi₂가 선택적으로 에피택시 성장하였으며, 정합성은 B-CoSi₂[110]//Si[110] and CoSi₂(111)//Si(111)이, 그리고 700℃에서는 A-CoSi₂[110]//Si[110], CoSi₂(002)//Si(002)을 나타내었다. Epitaxial films of CoSi₂were grown on Si(111) substrates by in situ solid-phase epitaxy in a ultrahigh vacuum. The phase, the chemical composition, the crystallinity, and the microstructure of the Silicide/Si interface were investigated by 2-MeV⁴He++ ion-backscattering spectrometry, quadruple crystal X-ray diffractometry, and high-resolution transmission eletron micorscopy. High-quality films of either B-type or A-type CoSi₂ could be grown selectively on Si(111) substrates by depositing ~ 20 ~ 50 ?? of Co on a Si(111)-7X7 substrate followed by in situ annealing at 600℃ or 700℃ for 10 min. The matching face relationships are CoSi₂[110]//Si[110] and CoSi₂(111)//Si(111) by B-type CoSi₂ and CoSi₂[110]//Si[110]//Si[110] and CoSi₂(002)//Si(002) for A-type CoSi₂.

화상으로 인한 소구증 환자의 치험례

지재휴,이병준,김영균,김수관,황경곤,여환호,박인순 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.3

Deep burns of the face & lips often lead to scarring and contraction of the circum-oral tissues with a marked reduction in the size of the oral aperture. Such burns most commonly caused by electrical contact, for example, children sucking electric plugs, or as a result of chemical burns and the exposture to flame. Once having burns, burned tissue may contract and reduce considerably the size and mobility of the mouth ; therefore bring up the resultant functional disturbance, verbal difficulty, even disgestive difficulty, and poor appearance, which fall into difficulty in social acceptability, caused by burns. In our department, 2 patients who were complain of functional limitations and esthetic problem owing to scar contracture, were visited, and we treated this microstomia with scar excision, graft and flap technique, and postoperative intensive physical therapy. We obtained relatively favorable results, thus report this cases with literature review.

단결정 Si(111) 위에 형성된 Ti-실리사이드에 대한 RBS 및 XRD 분석

이중환,권오준,최치규,박동수,김건호,이상환,이의완,곽호원 濟州大學校 基礎科學硏究所 1991 基礎科學硏究 Vol.4 No.1

초고진공 상태에서 p형 Si(111)기판에 Ti을 증착한 후 고진공에서 열처리하여 Ti-실리사이드를 형성시켰으며, Ti-실리사이드의 상전이 및 형성운동학은 2 MeV⁴He? 이온 후방산란과 x-선 회절방법으로 규명하였다. 형성된 TiSi₂는 결정학적으로 C49(ZrSi₂)와 C54 구조의 두 종류로 확인되었다. C49 TiSi₂상은 열처리온도가 700℃이하의 저온에서 형성되었고, 700℃ 이상의 고온에서는 C54 TiSi₂상으로 나타났다. 본 연구에서 확인된 C54 TiSi₂전이온도(??)는 700℃ 였고, TiSi₂형성온도 영역내에서 TiSi₂ 층두께(χ)와 열처리시간(t)의 관계는 저온(700℃ 이하)일 경우 ??이고, 고온(750℃ 이상)에서는 χ=ct+d 의 관계식이 만족됨을 알 수 있었다. 이것은 700℃ 이하에서 TiSi₂ 형성기구가 Si 확산에 의해 제어되며, 750℃ 이상에서는 핵형성 제어에 의하여 계면반응하는 것으로 나타났다. Titanium silicides were prepared by depositing titanium film on p-type Si(111) followed by annealing in ultra high vacuum. The growth kinetics of Ti-silicide has been studied by using ion backscattering spectrometry and x-ray diffractometry. Two crystallographic structures of Ti-silicide were identified the (ZrSi₂)structure and C54. The C49 TiSi₂ phase was formed at low annealing temperature(<700℃),and it transformed to the C54 phase over 700℃. The relation between the thickness of TiSi₂ layer(χ) and the annealing time(t) was ?? when annealing temperature was under 700℃ and χ=ct+d when that was over 750℃. The former implied that the formation of TiSi₂ was controlled by diffusion and the latter by nucleation of at the Ti/Si(111) interface.

쇄골하 정맥 카테터 제거 후 발생한 일과성 피질맹

김지훈,이규환,한시령,최영빈,김영인 대한신경과학회 1999 대한신경과학회지 Vol.17 No.5

산과 경막외마취가 분만에 미치는 영향

이현숙,김수연,김명희,김정환,방은치,강용인,조경숙,김수연 대한산부인과학회 2000 Obstetrics & Gynecology Science Vol.43 No.12

목적 : 무통분만을 위해 시행한 지속적 경막외제통이 분만에 미치는 영향을 살펴보고자 하였다. 연구방법 : 분만시 통증경감을 원하는 산모를 두군으로 나누어 자궁경부가 3-5cm 개대시 1군 산모 35명은 0.0625% bupivacaine과 0.2㎍/㎖ fentanyl을 혼합하여 지속적 경막외제통을 시행하였고, 2군 산모 43명은 nalbuphine 10mg을 근주하였다. 1군과 2군에서 분만 1기와 2기의 진행시 소요된 시간, 제왕절개술의 빈도, 신생아의 Apgar score 및 체중을 기록하였고 통증 정도는 0-100mm의 시각통증등급에따라 측정하였다. 통계는 모수검정에는 independent t-test, 비모수검정에는 chi-square test를 이용하여 p〈0.05인 경우 통계적 의의를 두었다. 결과 : 1. 1군에서 분만 1기와 2기가 연장되었지만 통계적 차이는 없었다. 2. 신생아의 체중 및 Apgar score는 두 군간에 차이가 없었다. 3. 제왕절개술의 빈도는 1군이 16%(7/35), 2군이 14%(6/43)로 두 군간에 유의한 차이는 없었다. 4. 통증정도는 1군에서 유의하게 낮았다. 결론 : 분만진통시 시행하는 경막외제통은 분만의 진행과정에 지장을 주지 않았고 제왕절개술의 빈도도 높이지 않았다. 경막외제통은 태아나 산모에게 안전하게 시행될 수 있으나 산모선택이나 마취방법, 산과적 수기에 세심한 주의가 필요하다고 사료된다. Background : The effect of epidural analgesia on the progress of labor is controversial. The objective of this study is to determine the effect of analgesia on the outcome of labor, especially cesarean delivery rate in the epidural group and non-epidural group, prospectively. Methods : All the parturients were divided into two groups, group 1(epidural group, n=35) and group 2(non-epidural group, intramuscular nalbuphine, n=43) randomly. Epidural analgesia was maintained with a continuous epidural injection of 0.0625% bupivacaine with 0.2 ㎍/㎖ fentanyl in the group 1 and nalbuphine 10 ㎎ was intramuscular injected in the group 2 when the cervix was dilated to at least 3-5 ㎝. The duration of first and second stage of labor, cesarean delivery rate, Apgar score and body weight of baby were recorded and pain score of parturient was recorded by 0-100 ㎜ visual analog scale. Results : The duration of first and second stage labor were prolonged in the group 1. But there were no significant differences in the duration of first and second stage labor, Apgar score and body weight of baby between the two groups. Cesarean delivery rate was 16%(n= 7/35) in the group 1 and 14%(n= 6/43) in the group 2, so there was no significant difference between the two groups. Pain score was significantly lower in the group 1 than the group 2. Conclusion : Epidural analgesia was not associated with increased cesarean delivery rate and provided safe and effective intrapartum pain control. Maternal-fetal factors and obstetric management, not epidural analgesia, are the most important determinants of the cesarean delivery rate.

디지탈 서보 시스템을 위한 속도 관측기의 설계

이치환 영남이공대학 1995 論文集 Vol.24 No.-

Several algorithms for estimating the instanteneous speed based on the incremental optic encoder are discussed in this paper. First and second order velocity observers are introduced along with simple polynomials. On comparing the performance of these techniques, Pulse-counting method and Period-counting method are robust in whole of operating range. First order velocity observer is shown less phase error than those of others. The derived algorithms are independent of the machine parameters and can be implemented easily based on microprocessor.

RTA방법에 의한 Pd- 실리사이드의 쇼트키 장벽 높이에 관한 연구

崔致圭,李雲煥 제주대학교 1988 논문집 Vol.26 No.-

본 연구에서는 RTA방법에 의하여 Pd-Si계에서 우수한 Pd-Si가 형성됨을 확인하였으며 grain의 크기는 약150~200??으로 나타났다. AES스펙럼인 분석에 의하여 Ar 이온으로 sputtering하면서 얻은 Pd와 Si의 조성비는 41.5%와 58.5%로써 Pd- 실리사이드 상이 PdSi상에 거의 비슷함을 알 수 있었으며, 91eV에서 나타난 line shape는 미시구조를 나타내는 PdSi의 특성 피이크임을 보였다. 100~300K의 온도 영역에서 측정한 전류-전압특성곡선으로부터 SBH값은 0.32~0.75eV로 온도가 증가함에 따라 직선적으로 증하하였고 ideality factor n은 일반적인 값 1~2에 만족하였으며 고온영역에서는 거의 1에 근접함을 Tu 등이 실험한 값과 거의 일치됨을 보였다(Herman 1983, Tu, 1981) Si(111)면에서는 100~150K온도범위, Si(100)면에서는 100~200K 온도범위에서는 재결합 생성중심에 의한 전류흐름을 보여 열처리시 defect를 제거하는데 충분하지 못한다는 것을 알 수가 있었다. 다라서 RTA방법에 의한 실리사이드 형성시 실리콘 표면 영역에서 발생한는 defect를 제거하는 방법만 보완시키면 PdSi접촉을 이용하는 어떤 바이폴라 집적회로의 응용에도 가능하며 RTA는 장시간 열처리를 수반하는 전기로 열처리 방법보다 더 간편하고, 소자의 다른 특성을 변화시키지 않으므로 전이금속 실리사이드 형성에 우수한 장치로 평가된다. Formation of the palladium silicides was performed by the rapid thermal annealing using quartaz-halogen tungsten lamps. The Schottky-barrier heights of palladium silicides on both n-type(100)and(111)-oriented Si wafers have been measrued in the temperature range 100-300k with use of a current-voltoge thechnique. Silicide formation was monitored by glancing -angle X-ray diffraction and AES. The values of the barrier heights are 0.32-0.74eV for Si(111) and 0.34-0.75eV for Si(100) at temperaure in the range 100-300k. The barrier heights depend primarily on the metal deposited and not on the partivular silicide phase.

打擊速度 및 溫度變化가 豫크랙을 가진 衝擊試驗片의 動的破壞靭性에 미치는 影響

兪在煥,李敬奉,金重吉,李致雨,吳世旭 慶南大學校 附設 工業技術硏究所 1989 硏究論文集 Vol.7 No.-

計裝化衝擊試驗에서 打擊速度와 溫度의 變化가 豫크랙을 揷入한 衝擊試驗片의 動的破壞靭性에 미치는 影響을 考察한 結果 다음을 알 수 있었다. 豫크랙을 揷入한 試驗片이 V-노치 試驗片에 比하여 實驗値의 分散度가 적으며 0℃以下의 溫度領域에서 動的破壞靭性의 有效性이 있었다. 또한 打擊速度와 實驗溫度의 影響은 溫度가 速度보다 훨씬 上廻하는 傾向이었다. The effect of various impact velocity and temperature on dynamic fracture toughness is tested with precracked Charpy specimen, and conclude following results. Precracked specimen has less dispersion of test results than V-notched specimen, unstable crack initiation load didn't agreed to maximum load at room temperature but at 0℃ below, thus, the availability of dynamic fracture toughness is relatively high. Comparing V-notched specimen, the precracked Charpy specimen represented lower shelf of temperature different. But, at this time, the absorbed energy is estimated equivalently. With the decrease of temperature, the reduction of fracture toughness was obvious, but the effect of impact velocity didn't appear.

光州 同福水源池의 富營養化 현상과 Photoplankton의 계절적 발생에 관한 연구

김병환,류일광,이치영,강영식 광주보건대학 1980 論文集 Vol.5 No.-

Eutrophication in the Lake Dongbock used as a source of water to Gwangju city was studied to examine the concentration of nutrients and distribution of phytoplanktons. Water sample was collected at 3 positions; surface water of influent area, lake center and pumping station from 18. May 1978 to 18. February 1980. A summary of the experimental results is shown as follows. (1) The phytoplankton identification in this investigation showed Cyanophyceae is 7 genera 8 species, Bacillariophyceae 16 genera 26 species and Chlorphyceae 16 genera 26 species; Total 39 genera 60 species. (2) To appear a dominated alge was Synedra, Melosira, Asterionella, Navicula, Gloecystis, Golenkia and Microcystis. (3) In the remarkly dominated specis of seasonal welfare s.p 1 and s.p 2, Synedra, Melosira, Asterionella and Gloecystis in spring- (May), and Microcystis, Aphanacapsa, Syrndra and Melosira in summer (Aug) occur the great deal of quantity, and is inclined to decrease in Autumn and Winter. (4) The concentration of nutrients for nitrogen and phosphorous was 1.124㎎/l and 0.775㎎/l. Because Melosira, Asterionella, Scenedesmus and Anabaena is occuring, it proved to be Eutrophic Lake. (5) As appearing indication of α and β mesosaprobic system; Anabaena, Microcystis, Oscillatoria, Melosira, Scnedesmus, Navicula and Antictrodesmus, the Lake Dong-bock continues to be a pollution.

長城湖의 水質變化에 관한 조사연구

김병환,류일광,이치영,강영식 광주보건대학 1985 論文集 Vol.10 No.-

Water quality of Changsung Lake was examined for 3 months from May 26, 1984 to November 27, 1984. For checking the water quality 3 sampling positions were selected. The results we obtained are as follows. 1. The average for Changsung Lake was 7.0-7.8 of pH, 0.7-1.0ppm of Biochemical oxygen demand(BOD), 0.088-0. 124ppm of Total phosphate, 0.200-0.308ppm of Total Nitrogen. 2. The phytoplankton identification in this investigation showed cyanophyta is 6 genera 7 species, Bacillariophyta 10 genera 14 species and Chlorophyta 18 genera 24 species; Total 34 genera 45 species. 3. To appear dominant algae was Asterionella gracillima, Lyngbya contorta, Melosira granulata, Melosira sp. Microcystis aeruginosa, Synedra ulna and Euglena sp. 4. A great number of Microcystis, Asterionella and Melosira relating to water bloom\ were found in Changsung Lake.