멤브레인구조를 갖는 다공질 실리콘 센서의 에탄올 가스에 대한 식별성

박광열,김성진 경남대학교 신소재연구소 2002 신소재연구 Vol.14 No.-

에탄올 (혹은 알콜) 가스 농도를 측정하기 위해 다공질 실리콘 층을 이용한 멤브레인 알콜 센서를 제조하였다. 에탄올은 실리콘 웨이퍼에 대해 침투성이 강하여 수용액 내에서 실리콘 웨이퍼를 가공할 때 반응을 촉진시키는 물질로서 자주 사용된다. 본 연구에서는 25%의 불화수소용액에서 만든 다공질 실리콘 층을 알코올 감지막으로 한 알코올센서를 제작하여 0%에서 0.5%의 알코올 농도범위에 대해 감지 특성을 측정하였다. 그 결과, 알코올 농도가 증가할 때 다공질 실리콘 층의 전기 전도가 증가하게 되어 측정된 전기저항은 알콜농도에 반비례하는 관계가 관측되었다. 응답 특성은 상용화가 가능할 정도로 양호한 응답속도 및 선형성을 보였다. Porous silicon gas sensors with membrane structure are fabricated to measure vaporous ethanol (called alcohol) concentration. Since ethanol is very strongly permeable into the silicon wafer, it is often used to aid chemical reaction when the silicon wafer is reacted under some aqueous solution. In this work, sensing properties were measured for the alcohol concentration from zero to 0.5 percent with the porous silicon layer formed in 25% HF solution. As the result, the measured resistance was observed to be inversely related to alcohol concentration due to the increase of the electrical conductivity by adsorption into porous silicon surface. The sensors showed good response time and linearity which they can be probably commercialized.

위암종과 Epstein-Barr 바이러스와의 연관성에 대한 연구

심광용,김호영,김효열,백순구,권상옥,조미연,이창훈,이종인 건국대학교 의과학연구소 2004 건국의과학학술지 Vol.14 No.-

Objectives: Epstein-Barr virus (EBV) has been known to be linked to a spectrum of neoplastic conditions, including nasopharyngeal carcinoma, Burkitt's lymphoma, peripheral T-cell lymphoma and Hodgkin's disease. This study aims to investigate the association of EBV with gastric carcinoma in Korea. Methods: Fifty-three cases of gastric adenocarcinoma were studied for evidence of EBV infection by EBV-encoded small RNA (EBER) in situ hybridization (ISH) on the paraffin sections and amplifying the EBV genome encoding envelop glycoprotein (gp220) with polymerase chain reaction (PCR) in fresh gastric cancer specimens. Results: EBER was detected in 7 (13.2%) of 53 gastric carcinomas and all cases were male. In 6 (85.7%) of 7 EBER-positive cases, the tumors were located in the upper and middle part of the stomach. EBER ISH study showed strong positivity in all the tumor cells, but negativity in surrouning lymphocytes, stromal cells and normal gastric mucosa. DNA PCR was positive in 23 (43.4%) of 53 gastric carcinomas, including all of 7 EBER-positive cases. Conclusion: We could observe some association of EBV with gastric carcinoma, and our findings about the charateristics of EBV-positive gastric cancers involving sex, site and histological type are similar to those in Japan. However, EBV-positive rate of gastric cancer is higher than in Japan and lower than in Western countries. Further studies to elucidate oncogenic mechanism of EBV in gastric cancer should be performed.

CEPA 및 2,4,5-TP處理가 萄葡 Campbell Early (Vitis IabruscanaL.)의 果實成熟에 미치는 影響

金基烈,高光出 서울大學校 農科大學 1977 서울대농학연구지 Vol.2 No.2

The growth regulators of CEPA and 2, 4, 5-TP were applied to Campbell Early grapes at the different times, concentrations and with various application methods, and their effects on fruit maturity were investigated through determination of berry color development with changers in fruit constituents. The results are as follows. 1. CEPA treated at the early 3rd fruit growth stage hastened berry color development by 3 days, but delayed by 3 days when treated at the 2nd fruit growth stage. 2. The application of 2,4,5-TP immediately before the 3rd fruit growth stage slowed color development remarkably (15 days), while the delaying effectless pronounced when treated after the third fruit growth stage. 3. The application of 2,4,5-TP immediately before the 3rd fruit growth stage slowed the initial cluster color development but harvest date was similar to that of the other treatment. 4. No appreciable difference in delayed color development was noted between dipping and/or spraying of 2,4,5-TP. 5. The higher dipping concentration of 2,4,5-TP exhibited the more slowed color advancement, thus the advancement delayed by 18 days at the concentration of 40 ppm. 6. 2,4,5-TP increased soluble solids content, decreased titrable acid and appreciably slowed anthocyanin development with the delayed color development. 7. Little translocation of 2,4,5-TP seemed to occur with in the cluster and/or the berry itself.

Hot Wall Epitaxy 법에 의한 CdIn_2S_4 단결정 박막의 성장과 광전류 특성

이상열,홍광준,박진성 한국센서학회 2002 센서학회지 Vol.11 No.5

수평 전기로에서 Cdln_2S_4 다결정을 합성하여 HWE(Hot Wall Epitaxy)방법으로 Cdln_2S_4 단결정 박막을 반절연성 GaAs (100)기판에 성장시켰다. Cdln_2S_4 단결정 박막의 성장 조건은 증발원의 온도 630 ℃, 기판의 온도 420 ℃ 였고 성장 속도는 0.5 ㎛/hr였다. Cdln_2S_4 단결정 박막의 결정성의 조사에서 10 K에서 광발광(photoluminescence) 스펙트럼이 463.9 nm (2.6726eV)에서 exciton emission 스펙트럼이 가장 강하게 나타났으며, 또한 이중 결정 X-선 요동 곡선(DCRC)의 반폭치(FWHM)도 127 arcsec로 가장 작아 최적 성장 조건임을 알 수 있었다. Hall효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 9.01 × 10 exp (16) /cm^3, 219 cm^2/V·s였다. Cdln_2S_4 /Sl(Semi-Insulated) GaAs(100) 단결정 박막의 광흡수와 광전류 spectra를 293K에서 10K까지 측정하였다. 광흡수 스펙트럼으로부터 band gap E_g(T)는 Varshni 공식에 따라 계산한 결과 2.7116eV - (7.74x10 exp (-4)eV/K)T^2/(T+434K)이었으며 광전류 스펙트럼으로부터 Hamilton matrix(Hopfield quasicubic mode)법으로 계산한 결과 crystal field splitting Δcr값이 0.1291 eV이며 spin-orbit Δso값은 0.0248 eV임을 확인하였다. 10K일 때 광전류 봉우리들은 n = 1일때 A_1-B_1-와 C_l-exciton 봉우리임을 알았다. A stoichiometric mixture of evaporating materials for Cdln_2S_4 single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, Cdln_2S_4 mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE)system. The source and substrate temperatures were 630℃ and 420℃, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of Cdln_2S_4 single crystal thin films measured with Hall effect by van der Pauw method are 9.01×10 exp (l6) cm^-3 and 219 cm^2/V·s at 293 K, respectively. The temperature dependence of the energy band gap of the Cdln_2S_4 obtained from the absorption spectra was well described by the Varshni's relation, E_g(T) = 2.7116 eV - (7.74× 10 exp (-4)eV)T^2/(T+ 434). The crystal field and the spin-orbit splitting energies for the valence band of the Cdln_2S_4 have been estimated to be 0.1291 eV and 0.0248 eV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the Δso definitely exists in the Γ_5 states of the valence band of the AgInS_2/GaAs epilayer. The three photocurrent peaks observed at 10K areascribed to the A_l-, B_l-, and Cl-exciton peaks for n = 1.

P2P 기반 자료공유시스템의 응용

양광민,주형렬 中央大學校經營硏究所 2002 經營學論集 Vol.29 No.1

참돌꽃 근경의 항산화작용

류광열,강원식,김영호,장해동,홍진태,유환수,윤여표 충남대학교 약학대학 의약품개발연구소 1998 藥學論文集 Vol.14 No.-

The purpose of this study was to determine the antioxidative effects of Rhodiola sachalinensis Rhodiola methanol extract was fractionated sequentially with dichloromethane and butanol. Each Rhodiola fraction (water, MeOH, BuOH and CH_2Cl_2 fractions) showed the potent superoxide dismutase (SOD) activity, and had inhibitory effets on peroxide value of linoleic acid (40~57%) and lipid peroxidation (47~70%) in FE^2+/ascorbate system-induced rat liver microsome. Rhodiola methanol extract also recovered carbon tetrachloride-induced decrease in SOD by 42% and catalase activities by 50%, and had inhibitory effects (54%) on carbon tetrachloride-induced lipid peroxidation in rat liver microsome. These results suggest that Rhodiola sachalinensis has the antioxidative effects.

ZnO 박막 성장과 광학적 특성 분석을 위한 펄스 레이저 증착(PLD)방법 적용

홍광준,김재열 한국공작기계학회 2005 한국생산제조학회지 Vol.14 No.2

ZnO epilayer was synthesized by the pulsed laser deposition(PLD) process on Al₂O₃ substrate after irradiating the surface of ZnO sintered pellet by ArF(193nm) excimer laser. The epilayers of ZnO were achieved on sapphire(Al₂O₃) substrate at the temperature of 400℃. The crystalline structure of epilayer was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of ZnO epilayer measured with Hall effect by van der Pauw method are 8.27x 1016cm^(-3) and 299㎠/Vㆍs at 293 K, respectively. The temperature dependence of the energy band gap of the ZnO obtained from the absorption spectra was well described by the Varshni's relation, E_(g)(T) = 3.3973eV - (2.69×10^(-4)eV/K)T²/(T + 463K). After the as-grown ZnO epilayer was annealed in Zn atmospheres, oxygen and vaccum the origin of point defects of ZnO atmospheres has been investigated by the photoluminescence(PL) at 10K. The native defects of V_(Zn), Vo, Zn_(int), and O_(int) obtained by PL measurements were classified as a donor or acceptor type. In addition, we concluded that the heat-treatment in the oxygen atmosphere converted ZnO thin films to an optical p-type. Also, we confirmed that vacuum in ZnO/Al₂O₃ did not form the native defects because vacuum in ZnO thin films existed in the form of stable bonds.

B형 간염 동반 원발성 간암 환자에서의 CYP2D6와 NAT2 다형현상에 관한 연구

신동일,이광수,최연남,황기은,조율희 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.2

The CYP2D6 and N-acetyltransferase (NAT2) are polymorphic enzymes which are expressed in the hepatocyte in a genotype-determined manner. CYP2D6 and NAT2 are known to be involved in the inactivation and activation of various mutagens and carcinogens, respectively. The activities of the two enzyme systems are associated with the genetic susceptibility of many human cancers. This study was performed to determine the genotype frequencies of the two enzyme systems in primary hepatocellular carcinoma patients and healthy controls. One hundred healthy controls and 55 liver cancer patients were analyzed by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The results are as followings:1. In the healthy controls, CYP2D6 wild type allele frequency was 0.985 and CYP2D6^*4 frequency was 0.015, and no CYP2D6 poor-metabolizer was detected. No significant differences were found in hepatocellular carcinoma patient group. 2. Frequencies of F, S1, S2 and S3 alleles of NAT2 system were 0.725, 0.01, 0.14 and 0.125 in controls, respectively. The genotype frequencies were found to be 0.91 of rapid acetylator and 0.09 of slow acetylator. No significant differences were found in hepatocellular carcinoma patient group. 3. These results suggest that the distribution of CYP2D6 and NAT2 polymorphisms is very unique in Korean populations characterized by extremely low frequency of CYP2D6 poor-metabolizer and NAT2 slow acetylator. CYP2D6 and NAT2 polymorphisms seemed not to play an important role in the hepatic carcinogenesis in Korean population.

C.V.D. 방법에 의한 Cd_0.78Zn_0.22 S박막 성장과 광전기적 특성연구

유상하,이상렬,홍광준,서상석,김혜숙,전승룡,윤은희,문종대 조선대학교 기초과학연구소 1993 自然科學硏究 Vol.16 No.1

We had grown Cd_0.78Zn_0.22S polycrystal thin films on slide substrate using chemical vapour deposition(CVD) method. We measured X-ray diffraction patterns in order to study Cd_0.78Zn_0.22S polycrystal structure. We studied its band gap using transmission curves and photocurrent and also analyzed photoluminescence using configurational coordinate model. We measured Hall effect·on this sample by Van der Pauw method and studied on carrier density and mobility depending on temperature.

n-CdS_(0.46)Se_(0.54)/p-Cu_92-x)S_(0.46)Se_(0.54) 이종접합 태양전지의 제작과 그 특성에 관한 연구

유상하,최승평,이상열,홍광준,서상석,김혜숙,전승룡,윤은희,문종대,신영진,정태수,신현길,김택성,유기수 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

승화방법에 의해 CdS_0.46Se_0.54 단결정을 성장하여 결정구조를 조사하고, Van der Pauw 방법으로 Hall effect를 측정하여 carrier density의 온도 의존성과 mobility의 온도 의존성을 조사하였다. 성장된 CdS_0.46Se_0.54 단결정을 치환반응하여 n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 이종접합 태양전지를 제작하였다. Spectral response, 전류-전압특성 및 전력변환 효율을 조사하여 그 결과로부터 개방전압은 0.48V, 단락 전류 밀도는 21mA/㎠, fill factor와 전력변환효율은 각각 0.75와 9.5%를 얻었다. CdS_0.46Se_0.54 single crystal was grown by a sublimation method. The crystal structure and the temperature dependence of carrier density and mobility of CdS_0.46Se_0.54 single crystal were studied. Heterojunction solar cells on n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 were fabricated by the substitution reaction. The spectral response, the J-U characteristics and the conversion efficiency of the n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells were studied. The open-cricuit voltage, short-circuit density, fill factor and conversion efficiency of n-CdS_0.46Se_0.54/p-Cu_2-xS_0.46Se_0.54 heterojunction solar cells under 80mW/㎠ illumination were found to be 0.48V, 21mA/㎠, 0.75 and 9.5%, respectively.