혼합소스 HVPE 방법에 의해 성장된 육각형 Si 결정

이강석,김경화,박정현,김소윤,이하영,안형수,이재학,전영태,양민,이삼녕,전인준,조채용,김석환,Lee, Gang Seok,Kim, Kyoung Hwa,Park, Jung Hyun,Kim, So Yoon,Lee, Ha Young,Ahn, Hyung Soo,Lee, Jae Hak,Chun, Young Tea,Yang, Min,Yi, Sam Nyung,Jeon, I 한국결정성장학회 2021 韓國結晶成長學會誌 Vol.31 No.3

고체 재료인 Si, Al 그리고 Ga을 혼합하는 혼합소스 수소화물기상 방법에 의해 육각형 Si 결정을 성장하였다. 새로 고안된 상압의 혼합소스 수소화물기상 방법에서는 1200℃의 고온에서 GaCl_n, AlCl_n 그리고 SiCl_n 가스 사이의 상호작용에 의해 핵이 형성된다. 또한 Si과 HCl 가스의 급격한 반응에 의해 높은 분압을 가진 전구 기체를 발생시키는 구조로 설계 되었다. 주사 전자 현미경(FE-SEM), 에너지 분산형 X-선 분광법(EDS), 고해상도 X-선 회절(HR-XRD) 그리고 라만 스펙트럼을 통하여 육각형 Si 결정의 특성을 확인하였으며, Si 산업 분야에서 새로운 소재로서 응용성이 기대된다. Hexagonal shape Si crystals were grown by the mixed-source hydride vapor phase epitaxy (HVPE) method of mixing solid materials such as Si, Al and Ga. In the newly designed atmospheric pressure mixed-source HVPE method, nuclei are formed by the interaction between GaCl_n, AlCl_n and SiCl_n gases at a high temperature of 1200℃. In addition, it is designed to generate a precursor gas with a high partial pressure due to the rapid reaction of Si and HCl gas. The properties of hexagonal Si crystals were investigated through scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), high-resolution X-ray diffraction (HR-XRD), and Raman spectrum. From these results, it is expected to be applied as a new material in the Si industry.

항공안전관리 향상을 위한 항공여객의 행동 변화 연구

이강석,Lee, K.S. 한국항공운항학회 2005 한국항공운항학회지 Vol.13 No.4

The research purpose of A Study on the Effect of Aviation Safety over the Air Passenger's Behavior for enhancement of aviation safety management lies at the judgement that passenger's airlines choice criteria has much changed after several serious aviation accidents as before when we used to overlook "aviation safety" variable through surveying to Korean aviation passengers and foreigners visit or travel Korea on various purposes. This study will be regarded significant in terms that empirical analysis was used to prove "Aviation Safety", a variable which had not been regarded as a airline choice factor within Korea air transport market so far, and has an effect on the air passengers' airline preference change and choice after recent frequent aviation accidents. I wish, it can be another opportunity for Korean two national flag airlines to reappraise and reinforce the significance of "aviation safety" and set forth immediate vigorous efforts to support the government's aviation safety improvement countermeasures.

혼합소스 HVPE 방법에 의한 전력 반도체 소자용 p형 AlN 에피층 성장

이강석,김경화,김상우,전인준,안형수,양민,이삼녕,조채용,김석환,Lee, Gang Seok,Kim, Kyoung Hwa,Kim, Sang Woo,Jeon, Injun,Ahn, Hyung Soo,Yang, Min,Yi, Sam Nyung,Cho, Chae Ryong,Kim, Suck-Whan 한국결정성장학회 2019 韓國結晶成長學會誌 Vol.29 No.3

본 논문에서는 전력 반도체 소자용 Mg-doped AlN 에피층을 혼합 소스 수소화물 기상 에피택시 방법에 의해 성장하였다. p형 재료로는 Mg을 사용하였다. 소자응용을 위한 기초 기판으로서 역할을 하기 위하여 GaN 에피층이 성장된 기판과 GaN 에피층이 성장되어 패턴이 형성된 사파이어 기판 위에 Mg-doped AlN 에피층을 선택 성장하였다. Mg-doped AlN 에피층의 표면과 결정 구조는 FE-SEM 및 HR-XRD에 의해 조사하였다. XPS 스펙트럼과 라만 스펙트럼 결과로부터 혼합소스 HVPE 방법에 의해 성장된 Mg-doped AlN 에피층은 전력소자 등에 응용이 가능할 것으로 판단된다. In this paper, Mg-doped AlN epilayers for power semiconductor devices are grown by mixed-source hydride vapor phase epitaxy. Magnesium is used as p-type dopant material in the grown AlN epilayer. The AlN epilayers on the GaN-templated sapphire substrate and GaN-templated-patterned sapphire substrate (PSS), respectively, as the base substrates for device application, were selectively grown. The surface and the crystal structures of the AlN epilayers were investigated by field emission scanning electron microscopy (FE-SEM) and high-resolution-X-ray diffraction (HR-XRD). From the X-ray photoelectron spectroscopy (XPS) and Raman spectra results, the p-type AlN epilayers grown by using the mixed-source HVPE method could be applied to power devices.

꽃게 ( Portunus trituberculatus ) Hemocyanin 의 정제 및 특성에 관하여

이강석,김상복,이정호 ( Kang Suk Lee,Sang Bog Kim,Jung Ho Lee ) 생화학분자생물학회 1985 BMB Reports Vol.18 No.2

The hemocyanin from the hemolymph of crab, Portunus trituberculatus which belong to crustacean was purified by a single step of ion-exchange column chromatography after dialysis and ultracentrifugation. The purified hemocyanin was revealed a high degree of polymorphism after analyzed it by Davis-polyacrylamide gel electrophoresis, the peroxidase activity, and copper staining method. On the other hand, the denatured hemocyanin was appeared to be homogeneous polypeptide by SDS-PAGE, and the approximate molecular weight was estimated to be 70,000. It was found that the purified hemocyanin was a glycoprotein in nature that contained 2 males of copper/l mole of hemocyanin, and it was estimated that their contents in normal body fluid were approximately 46%.

Studies on Histones from Sracoma 180 Ascites Tumor Cells. Biosynthesis and Phosphorylation

이강석,Lee, Kang-Suk 생화학분자생물학회 1971 한국생화학회지 Vol.4 No.2

1. Histone fractions, f1, f2b, f2a2, f3 and f2a1 were isolated from Sarcoma 180 ascites tumor cells and characterized by acrylamide disc electrophoresis, phosphorylation in vitro and amino acid analysis. 2. The rate of incorporation in vivo of L-Iysine-$^{14}C$ into different histone fractions isolated from tumor cells and tumor-bearing liver of mice has been determined for the study of biosynthesis. The fraction f2b from the tumor cells showed the highest incorporation rate, whereas the fraction f2a2 exhibited the lowest. No marked differences in the incorporation rate of the lysine-$^{14}C$ into the fractions f3, fl and f2a1 were observed 3. In the experiments with tumor-bearing mouse liver, the rate of lysine-$^{14}C$ into the histone fractions fl, f2a1, f2a2 and f3 was very similar to each other. On the other hand, the rate of incorporation of lysine-$^{14}C$ into the fraction f2b was approximately twice as high as that into other fractions. 4. The incorporation rate of lysine-$^{14}C$ into histone fractions isolated from the tumor cells was higher (approximately 1.5 times) than that into liver histone fractions. 5. Amino acid composition of the whole histone from the tumor cells is very similar to the published values for calf liver and kidney and rat liver. It is also similar to that for calf thymus except for the lower content of basic amino acids and lower ratio of basic residues. The whole histone fractions isolated from the tumor cells contained much less proline and methionine and much more glutamic acid, as compared with that isolated from others. Amino acid composition of the whole histone isolated from tumor-bearing liver of mice showed higher content of basic amino acids and lower content of acidic residues. 6. The relative amounts of incorporation in vitro of $^{32}P$ into different histone fractions from cells have been determined. The incorporation of $^{32}P$ into histone fractions f2b was the greatest, while almost no radioactivities were observed in the fractions f2a1 and f2a2. The incorporation of the radioisotopes into remaining fractions was variable from one fraction to another, the incorporation rate into the fraction fl being higher than that into the f3 fraction. 7. Evidence was obtained confirming the presence of phosphoserine in histone fractions f2b, f1 and f3 from cells. It was shown that a greater amount of $^{32}P$ was incorporated into the fraction f2b. being present in the form of phosphoserine in the proteins. 1. Sarcoma 180 ascites tumor cells에서 histone 분획 f1, f2b, f2a2, f3 및 f2a1을 각각 추출 정제하여 각 분획을 acrylamide disc electrophoresis. $^{32}P$를 사용하여 in vitro에서 phosphorylation 및 amino 산 조성을 관찰하여 이 물질들의 성상을 밝혔다. 2. 마우스의 복수암 세포 및 간에 lysine-$^{14}C$을 in vivo에서 incorporate 시켜 histone의 생합성을 각 분획별로 비교 관찰하였다. 복수암 세포 histone 에서는 lysine-$^{14}C$이 f2b 분획에 가장 많이 incorporate 된 반면 f2a2가 가장 적었다. 분획 f3, f1 및 f2a1에는 차이가 없이 비슷하였다. 3. 복수암이 이식된 마우스의 간 histone에 lysine-$^{14}C$의 incorporate 된 비율은 분획 f2b가 다른 분획 보다 2배 높았고 분획 f1, f2a1, f2a2 및 f3는 거의 비슷하였다. 4. Lysine-$^{14}C$의 incorporation은 복수암 histone 분획들이 간 histone 분획 보다 1.5 배나 더 많이 일어났다. 5. 복수암 세포 histone의 amino 산 조성은 이미 보고된 소의 간, 신장 및 흰쥐의 간 histone과 비슷하였다. 또 소 흉선 histone의 amino 산 조성에 비하면 염기성 amino 산 함량이 낮은 것과 산성 amino 산에 대한 염기성 amino 산의 비율이 낮은 점을 제외하고는 유사하였다. 복수암 세포의 총 histone을 기타 정상조직 histone과 비교하면 proline과 methionine이 대단히 적었고 glutamic acid의 함량이 더 많았다. 복수암을 이식한 마우스 간의 총 histone 의 amino 산 조성은 정상조직과 비교하면 염기성 amino 산 함량이 높았으며 산성 amino 산 함량이 낮었다. 6. 복수암 세포의 핵을 in vitro 에서 $^{32}P$와 함께 incubate 하고 histone 각 분획에 incorporate 되는 비율을 관찰하였다. Histone 분획 f2b에 가장 많이 $^{32}P$가 incorporate 된 반면 분획 f2a1 및 f2a2에는 거의 incorporate 가 일어나지 않았다. 기타 분획에 incorporate 되는 비율은 큰 차이를 나타냈다. 즉 분획 f1이 f3 보다 높은 방사능을 나타냈다. 7. Phosphoserine을 복수암 세포의 histone 분획 f2b, f1 및 f3에서 분리 확인하였으며 이런 점으로 미루어 분획 f2b 단백질 내에 phosphoserine의 형태로 많은 량의 $^{32}P$가 incorporate 됨을 알 수 있었다.

격자자료분석을 위한 이웃정보시스템의 비교

이강석,신기일,Lee, Kang-Seok,Shin, Key-Il 한국통계학회 2008 응용통계연구 Vol.21 No.3

Recently many researches on data analysis using spatial statistics have been studied in various field and the studies on small area estimations using spatial statistics are in actively progress. In analysis of lattice data, defining the neighborhood information system is the most crucial procedure because it also determines the result of the analysis. However the used neighborhood informal ion system is generally defined by sharing the common border lines of small areas. In this paper the other neighborhood information systems are introduced and those systems are compared with Moran's I statistic and for the comparisons, Economic Active Population Survey (2001) is used. 최근 공간통계를 이용한 많은 연구가 진행되고 있고 공간통계학을 접목한 소지역 추정(small area estimation) 방법이 좋은 결과를 주고 있는 것으로 알려져 있다 소지역 추정에 사용되는 격자자료(lattice data) 분석에서 이웃정보를 정의하는 것은 자료 분석의 성패를 결정짓는 매우 중요한 부분이다. 그러나 기존에 사용된 대부분의 이웃정보시스템은 경계선을 공유할 때 이웃으로 정하는 방법을 사용하고 있다. 이에 본 논문에서는 경계선 공유를 이용한 이웃정보시스템 뿐 아니라 다른 여러 이웃정보시스템을 구하는 방법을 설명하고 2001년 경제활동자료를 이용하여 이 시스템들을 비교하였다

광합성 세균 Rhodobacter capsulata 에 의한 우라늄 흡착

이강석,김진규,김인규,박효국,이정호 ( Kang Suk Lee,Jin Kyu Kim,In Gyu Kim,Hyo Kook Park,Jeong Ho Lee ) 한국하천호수학회 1990 생태와 환경 Vol.23 No.4

Aqueous waste effluents from nuclear fuel processing operations may contain trace quantities of heavy metals such as uranium, Conventional treatment of waste waters may be ineffective or expensive when uranium concentrations in the waste water must be reduced down to 1 ㎍/㎖ or less. The ability of some microorganisms to uptake or adsorb dissolved heavy metals offers an alternative method for waste treatment. The adsorption of uranium by Rhodobacter capsulata DSM 1710, a strain of photosynthetic bacteria, was examined to identify factors that might affect a process for the removal of uranium from aqueous solution. The optimal pH for uranium adsorption was 4.5. Temperature had little or no effect on the process since more than 95% of dissoved uranium was adsorbed to the bacterial biomass within 10 minutes after mixing of cell biomass at 25, 30, and 40 ℃, all the same. Maximum capacity of uranium adsorption by R. capsulata DSM 1710 was equivalent to 1/4 of the dry cell mass (248 ㎍ U/㎎-dry biomass), the highest among the reported so far.

기존 R/C 건축물의 내진진단기준

이강석,Lee, Kang Seok 한국구조물진단유지관리공학회 2012 한국구조물진단유지관리공학회지 Vol.16 No.1

꽃게 (Portunus trituberculatus) Hemocyanin의 정제 및 특성에 관하여

이강석,김상복,이정호,Lee, Kang-Suk,Kim, Sang-Bog,Lee, Jung-Ho 생화학분자생물학회 1985 한국생화학회지 Vol.18 No.2

꽃게 (P. trituberculatus) hemolymph를 채취한 후 원심분리 및 DEAE-Sephadex A-50 column chromatgraphy를 행하여 hemocyanin을 정제하였다. 정제된 hemocyanin은 단일 polypeptide로 이루어져 있었으며 monomer의 분자량은 약 70,000으로 추정 되었다. 또한 꽃게 hemolymph 단백질중 hemocyanin의 함량은 46%, Cu는 단일 polypeptide 당 2 mole, 그리고 당 함량은 단백질 mg 당 $10\;{\mu}g$ 이었다. 한편 정제된 hemocyanin은 Ca등 2가 이온을 가하지 않고 pH 5.7~8.9인 상태에서 mono, di, tri, tetra, pentamer등 다양한 polymorphism을 나타내었다. The hemocyanin from the hemolymph of crab, Portunus trituberculatus which belong to crustacean was purified by a single step of ion-exchange column chromatography after dialysis and ultracentrifugation. The purified hemocyanin was revealed a high degree of polymorphism after analyzed it by Davis-polyacrylamide gel electrophoresis, the peroxidase activity, and copper staining method. On the other hand, the denatured hemocyanin was appeared to be homogeneous polypeptide by SDS-PAGE, and the approximate molecular weight was estimated to be 70,000. It was found that the purified hemocyanin was a glycoprotein in nature that contained 2 moles of copper/l mole of hemocyanin, and it was estimated that their contents in normal body fluid were approximately 46%.

A New Discrete Size Optimization Method for Structures Using Harmony Search Heuristic Algorithm

이강석,Lee, Gang-Seok Computational Structural Engineering Institute of 2013 전산구조공학 Vol.26 No.1