• 제목/요약/키워드: $\delta^{13}C$

검색결과 464건 처리시간 0.03초

Comparison of Terminal-restriction Fragment Length Polymorphism (T-RFLP) Analysis and Sequencing of 16S rDNA Clones in marine sediments

  • Lee Jung-Hyun
    • 한국미생물학회:학술대회논문집
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    • 한국미생물학회 2002년도 추계학술대회
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    • pp.15-21
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    • 2002
  • Terminal-restriction fragment length polymorphism (T-RFLP) analysis has been optimized by using in vitro model community composed of genomic DNAs of known bacterial strains and has been applied to assess the bacterial community structure in marine sediments. The specific fluorescence-labeled terminal restriction fragments (T-RFs) between 39 and 839 base long specifying each strain were precisely measured for known bacterial strains. The addition of a co-solvent (dimethylsulfoxide or glycerol) into PCR reactions has reduced differential PCR amplification. Comparative bacterial community structure was investigated for pristine and polluted sediments. A complex T-RFLP pattern showing complex bacterial community structure was obtained in the pristine sediment, whereas simple T-RFLP pattern (low bacterial diversity) was shown in polluted sediments where caged aquaculture has been conducted for several years. The results of T-RFLP analysis were compared with that of cloning and sequencing 16S rDNA clones from the same sediments. Sequence analysis of 16S rDNA clones (72) of the pristine sediment revealed a diverse collection of lineages, largely of the class Proteobacteria ($6\%$ alpha subdivision, $46\%$ gamma subdivision, $13\%$ delta subdivision, and $3\%$ epsilon subdivision), Nitrospina $(8\%)$, high G+C gram positive $(8\%)$, Verrucomicrobia $(7\%)$, and Planctomycetes $(6\%)$. In the contaminated sediments, 17 $(59\%)$ of the 16S rDNA clones (29) were related to Campylobacter and symbiont of Rimicaris exoculata belonging to epsilon subdivision of Proteobacteria. The results obtained indicated that T-RFLP analysis is a rapid and precise technique for comparative bacterial community analysis.

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Characteristics of Sucrose Thermal Degradation with High Temperature and High Pressure Treatment

  • Woo, Koan-Sik;Hwang, In-Guk;Lee, Youn-Ri;Lee, Jun-Soo;Jeong, Heon-Sang
    • Food Science and Biotechnology
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    • 제18권3호
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    • pp.717-723
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    • 2009
  • Thermal degradation characteristics of sucrose was investigated. A 20% sucrose solution was heated to temperatures of $110-150^{\circ}C$ for 1-5 hr. Chromaticity, pH, organic acids, 5-hydroxymethylfurfural (HMF), free sugars, electron donating ability (EDA), and ascorbic acid equivalent antioxidant capacity (AEAC) of the heated sucrose solutions were evaluated. With increasing temperatures and times, the L-, a-, and b-values decreased; however, total color difference (${\Delta}E_{ab}$) increased. The pH and sucrose contents decreased, and fructose and glucose contents increased with increasing heating temperature and time. Organic acids, such as formic acid, lactic acid, and levulinic acid, and HMF contents increased with increasing heating temperatures and times. EDA (%) and the AEAC of the heated sucrose solutions increased with increasing heating temperature and time. The heated sucrose solution was more effective than unheated sucrose solution, having higher EDA (90 fold), and AEAC (13 fold).

급속열처리산화법으로 형성시킨 $SiO_2$/나노결정 Si의 전기적 특성 연구 (Electrical properties of metal-oxide-semiconductor structures containing Si nanocrystals fabricated by rapid thermal oxidation process)

  • 김용;박경화;정태훈;박홍준;이재열;최원철;김은규
    • 한국진공학회지
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    • 제10권1호
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    • pp.44-50
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    • 2001
  • 전자빔증착법과 이온빔의 도움을 받는 전자빔 증착법(ion beam assisted electron beam deposition; IBAED)법으로 비정질 Si(-200nm) 박막을 p-Si 기판위에 성장하고 이 두 구조를 급속열처리산화(Rapid Thermal Oxidation; RTO)를 시킴으로서 $SiO_2$/나노결정 Si(nanocrystal Si)/p-Si구조를 형성하였다. 그 후 시료 위에 Au 막을 증착함으로서 최종적으로 나노결정이 함유된 MOS(metal-oxide-semiconductor)구조를 완성하였다. 이 MOS구조내의 나노결정 Si의 전하충전 특성을 바이어스 sweep 비율을 변화시키면서 Capacitance-Voltage(C-V) 특성을 측정하여 조사하였다. 전자빔증착시료의 경우에는 $\DeltaV_{FB}$(flatband voltage shift)가 1V 미만의 작은 C-V 이력곡선이 관측된 반면 IBAED 시료의 경우는 $\DeltaV_{FB}$가 22V(2V/s Voltage Sweep비율) 이상인 대단히 큰 C-V 이력곡선이 관측되었다. 전자빔증착중 Ar ion beam을 조사하면 표면 흡착원자이동이 활성화되고 따라서 비정질 Si내에 Si의 핵 생성율이 증가하여 후속 급속열처리산화공정중 이 높은 농도의 핵들이 나노결정 Si으로 자라나게 되고 이렇게 형성된 높은 농도의 나노결정의 전하 충전 및 방전현상이 큰 이력곡선을 나타내는 원인이라고 생각된다. 따라서 IBAED 방법이 고농도의 나노결정 Si을 형성시키는데 유용한 방법이라고 판단된다.

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In-situ ellipsometry를 사용한 광기록매체용 Ge-Sb-Te 다층박막성장의 실시간 제어 (Real time control of the growth of Ge-Sb-Te multi-layer film as an optical recording media using in-situ ellipsometry)

  • 김종혁;이학철;김상준;김상열;안성혁;원영희
    • 한국광학회지
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    • 제13권3호
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    • pp.215-222
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    • 2002
  • 광기록매체용 Ge-Sb-Te다층박막 성장과정을 in-situ 타원계를 사용하여 실시간으로 모니터하여 각 층의 두께를 제어하고 성장된 Ge-Sb-Te 다층박막을 ex-site 분광타원법으로 확인하였다. 보호층인 ZnS-SiO$_2$와 기록층인 Ge$_2$Sb$_2$Te$_{5}$을 단결정실리콘 기층 위에 스퍼터링 방법으로 각각 성장시키면서 구한 타원상수 성장곡선을 분석하여 성장에 따르는 보호층의 균일성 및 기록 층의 밀도변화를 파악하고 이를 기초로 하여 Ge-Sb-Te광기록 다층박막의 두께를 정밀하게 제어하였다. Ge$_2$Sb$_2$Te$_{5}$ 단층박막 시료의 복소굴절율은 eX-Situ 분광타원분석을 통하여 구하였다. 제작된 다층구조는 설정된 다층구조인 ZnS-SiO$_2$(1400$\AA$)$\mid$ GST(200 $\AA$)$\mid$ZnS-SiO$_2$(200$\AA$)와 각 층의 두께 및 전체 두께에서 1.5% 이내에서 일치하는 정확도를 보여주었다.주었다.

춘천 중도 유적에서 출토된 원삼국시대 토기 탄착물에 대한 화학적 분석 (Organic Analysis of Charred Residues on the Pottery in the Proto-Three Kingdom from Joong-do Site, Chuncheon)

  • 강소영;지상현;김윤지;장홍선
    • 보존과학회지
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    • 제29권4호
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    • pp.437-444
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    • 2013
  • 춘천 중도 유적에서 출토된 원삼국시대 경질무문토기 내부의 탄화된 물질에 대한 화학적 분석을 실시하였다. 가스크로마토그래피-질량분석과 퓨리에변환적외선분광분석을 이용하여 부착물에서 유래한 유기물의 정성분석을 수행한 결과, 지방산, 스테롤 등 지방성분이 검출되지 않았다. 탄소와 질소 안정동위원소 분석 결과 부착물을 구성하고 있는 탄소 안정동위원소 비는 평균 $-14.7{\pm}2.8$‰ (-8.7‰~-18.4‰, n=9), 질소 안정동위원소 비는 평균 $6.2{\pm}1.1$‰(-4.4‰~-7.6‰, n=9)로 나타났는데 이 결과는 부착물이 조리된 음식물에서 유래되었음을 추정할 수 있는 과학적 근거라고 할 수 있다. 본 연구결과는 안정동위원소 분석을 조리용 토기 내 탄화된 잔존물 분석에 적용한 국내 첫 사례로서 당시의 토기 용도와 식생활 습관에 대한 중요한 정보를 제공할 것으로 기대된다.

공기유입시스템에서의 섬유매체에 의한 방사성액체폐기물 처리에 관한 연구 (A Study on the Treatment of Radioactive Liquid Wastes using Synthetic textile by Air Intake System)

  • 김태국;이영희;안섬진;손종식;홍권표
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.101-104
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    • 2003
  • 저준위 방사성액체폐기물 처리방법으로 에너지 소모가 적은 경제적이고 효율적인 처리방법을 제시하기 위하여 면 과 Polyester 가 함유된 합성섬유를 증발매체로 하여 자연기상 상태의 건조한 공기를 유입하여 방사성 액체폐기물과 접촉시켜 증발하는 연구를 하였다. 본 연구에서는 자연상태의 공기를 강제 유입시켜 액체의 증발현상, 증발매체표면에서의 물질전달 등 이론을 토대로 방사성액체폐기물을 처리하는 연구를 수행하였다. 실험은 방사성폐액을 직접 사용하였으며, 증발에 영향을 미치는 변수에 따라 증발 단위 면적당 방사성 폐액의 증발량측정 및 제염계수를 조사하였다. 증발효과는 유입공기의 습도가 낮고 공기의 유속과 공급액의 유량이 증가하고 폐액의 온도가 높아질수록 증발량이 증가하였다. 실험결과 습도는 70% 이하, 공급폐액의 유량이 $3.4{\ell}/hr\cdotm^2$ 이상, 공기유속은 1.14~l.47 m/sec 범위가 조업조건이며, 이때 제염계수는 $5.1{\times}10^3$, 배출공기의 방사능 농도는 $4.7{\times}10^{-13}{\mu}Ci/\textrm{m}{\ell}{\cdot}air$로 측정되었다. 공급유량이 $4.6{\ell}/hr\cdotm^2$와 공기유속이 1.47 m/sec일때 최대 증발조건으로 확인되었으며 대기의 온.습도 및 풍속에 따른 실험을 통하여 달톤형의 증발식 Air factor $[\textit{Eh}=(0.018 + 0.0141\textitv) {\delta}textitH]$를 도출하였다.

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연폭로 지표들의 정상치에 관한 연구 (A Study on the Normal Values of Lead Exposure Indices)

  • 신해림;김준연
    • Journal of Preventive Medicine and Public Health
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    • 제19권2호
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    • pp.167-176
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    • 1986
  • For the purpose of determinating the normal values of some parameters relevant to lead exposure, a study was carried out from April 1 to June 30, 1986 on 258 healthy Korean adults who have had no apparant lead exposure. The lead indices subjected to this study were as follows; blood lead (PbB), hemoglobin (Hb), zinc protoporphyrin in blood (ZPP), delta-aminolevulinic acid dehydratase (ALAD) activity in blood, coproporphyrin in urine (CPU), delta-aminolevulinic acid in urine (ALAU). 1) The mean value of PbB was $17.17{\pm}7.87{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of PbB fitted to the log-normal distribution ($x^2=7.38$, p>0.1). 2) The mean value of Hb in male ($15.17{\pm}1.56g/100ml$) was higher than in female ($13.22{\pm}1.51g/100ml$)(p<0.01). The distribution of Hb fitted to the normal distribution ($x^2=9.40$, p>0.1). 3) The mean value of ZPP was $32.61{\pm}8.78{\mu}g/100ml$, and there was no statistically significant difference by age & sex. The distribution of ZPP fitted to the normal distribution ($x^2=13.93$, p>0.05). The correlation of ZPP & ALAD (r=-0.229), CPU (r=0.183) was statistically significant respectively. 4) The mean value of ALAD was $30.20{\pm}10.96{\mu}mol$ ALA/min/L of R.B.C., and there was no statistically significant difference by age & sex. The distribution of ALAD activity did not fit to the normal distribution. The correlation between ALAD & PbB (r=-0.219) was statistically significant 5) The mean value of CPU was $36.10{\pm}24.54{\mu}g/L$, and there was no statistically significant difference by age & sex. The distribution of CPU did not fit to the normal distribution. The correlation between CPU & PbB (r=0.185), ZPP (r=0.183) was statistically signinificant respectively. 6) The mean value of ALAU was $1.94{\pm}0.96mg/L$, and there was no statistically significant difference by age & sex. The distribution of ALAU fitted to the normal distribution ($x^2=9.76$, p>0.1).

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Hot Wall Epitaxy(HWE)법에 의한 BaIn2S4 단결정 박막 성장과 광전도 특성 (Growth and optical conductivity properties for BaIn2S4 single crystal thin film by hot wall epitaxy)

  • 정경아;홍광준
    • 한국결정성장학회지
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    • 제25권5호
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    • pp.173-181
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    • 2015
  • A stoichiometric mixture of evaporating materials for $BaIn_2S_4$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $BaIn_2S_4$ 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 $620^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by double crystal X-ray diffraction (DCXD). The carrier density and mobility of $BaIn_2S_4$ single crystal thin films measured from Hall effect by van der Pauw method are $6.13{\times}10^{17}cm^{-3}$ and $222cm^2/v{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $BaIn_2S_4$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=3.0581eV-(3.9511{\times}10^{-3}eV/K)T^2/(T+536K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $BaIn_2S_4$ have been estimated to be 182.7 meV and 42.6 meV, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_5$ states of the valence band of the $BaIn_2S_4/GaAs$ epilayer. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-exciton for n = 1 and $C_{24}$-exciton peaks for n = 24.

Mn-전기석(Tsilaisite)의 합성 및 리트벨트 구조분석 (Synthesis and Rietveld Structure Refinement of Mn-Tourmalines (Tsilaisite))

  • ;최진범
    • 한국광물학회지
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    • 제19권1호통권47호
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    • pp.15-29
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    • 2006
  • 2 Kbar, $375{\sim}700^{\circ}C$ 조건하에서, 드라바이트의 Mg를 전 구간 치환하는 Mn 조성(Mn%=0, 25, 50, 75, 및 100%)을 가지고 열수법으로 약 50일간 성장시켜 Mn-전기석(tsilaisite)을 합성하였다. 그 결과, 조성별로 생성온도가 다른 6개의 합성 전기석이 얻어졌으며, 앨바이트, 스페샤틴, 능망간석, 금운모 등 다양한 불순물이 함께 생성되었다. 합성 Mn-전기석의 X-자리의 자리결손($0.53{\sim}0.68$)이 천연산(약 $0.2{\sim}0.3$)보다 높게 나타났으며, Y-자리의 Mn mole wt.%는 예상보다 낮은 값을 보이며, 단종 성분의 tsilaisite를 합성하지 못했다. 다양한 복합상으로 이루어진 분말 합성 전기석에 대해 리트벨트 구조분석을 실시하였다. $R_{wp}$값은($R_{p}/R_{exp}$)은 $13.35{\sim}18.62%$의 범위를 보여주며, $R_{B}$ 값은 $4.85{\sim}6.25%$ (S-18: 8.57%), S (GofF) 값은 $1.31{\sim}l.59$ (S-18: 1.81)으로 각각 나타났다. 단위포의 평균값은 공간군 R3m (z=3)으로 ${\alpha}=15.8994\;{\AA},\;c=7.1846\;{\AA}$이며, S-18은 ${\alpha}=15.9491\;{\AA},\;c=7.1773\;{\AA}$이다. 평균 값은 $2.67{\sim}2.69\;{\AA}$ (S-18: $2.65\;{\AA}$), 평균 값은 $2.00{\sim}2.02{\AA}$ (S-18: $1.96\;{\AA}$)으로 각각 계산되었으며, 대칭도(ditrigonality)를 나타내는 ${\delta}$값을 보면 $0.022{\sim}0.031$ (S-18: 0.061)의 범위를 가지는데 Mn 함량이 높아지면서 대칭도가 낮아진다.

라미실 정(테르비나핀 125mg)에 대한 터비넥스 정의 생물학적동등성 (Bioequivalence of Terbinex Tablet to Lamisil Tablet (Terbinafine 125mg))

  • 고현철;홍정희;신인철
    • Biomolecules & Therapeutics
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    • 제11권1호
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    • pp.65-71
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    • 2003
  • Terbinafine is a synthetic allylamine that is available in an oral formulation and is used at a dosage of 250mg/day. It is used as an active antifungal agent and inhibits the fungal enzyme squalene epoxidase, which leads to the accumulation of the sterol squalene, which is toxic to the organism. The purpose of the present study was to evaluate the bioequivalence of two terbinafine tablets, Lamisil (Novartis Korea Ltd.) and Terbinex (C-TRI Ltd.), according to the guidelines of Korea Food and Drug Administration (KFDA). Eighteen normal male volunteers, 26.00$\pm$2.57 year in age and 70.51$\pm$9.36 kg in body weight, were divided into two groups and a randomized 2${\times}$2 cross-over study was employed. After one tablet containing 125 mg of terbinafine was orally administered, blood was taken at predetermined time intervals and the concentrations of terbinafine in plasma were determined using HPLC with UV detector. Pharmacokinetic parameters such as AUC, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters. The results showed that the differences in AUC, $C_{max}$ and $T_{max}$ between two tablets were -4.191%, 5.223% and -25.720%, respectively when calculated against the Lamisil, tablet. The powers (1-$\beta$) for AUC, $C_{max}$ and $T_{max}$ were 81%, 87% and below 60%, respectively. Minimum detectable differences(.il) at alpha=O.1 and 1-/3=0.8 were less than 20% (e.g., 19.72% and 17.77% for AUC and $C_{max}$, respectively). But minimum detectable differences($\Delta$) at alpha=0.1 and 1-$\beta$=0.8 for $T_{max}$ were more than 20% (e.g., 26.25%). The 90% confidence intervals were within $\pm$20% (e.g., -17.440∼9.06 and -6.713∼17.160 for AUC and $C_{max}$ respectively). But 90% confidence intervals for $T_{max}$ were not within $\pm$20% (e.g., -43.346∼8.083). Another ANOVA test was conducted for logarithmically transformed AUC and $C_{max}$. These results showed that there are no significant differences in AUC and $C_{max}$ between the two formulations: The differences between the formulations in these log transformed parameters were all for less than 20% (e.g., -4.19% and 5.22% for AUC and $C_{max}$, respectively). The 90% confidence intervals for the log transformed data were not the acceptance range of log 0.8 to log 1.25 in AUC but the acceptance range of log 0.8 to log 1.25 in $C_{max}$ (e.g., log 1.13∼log 1.50 and log 0.94-log 1.22 for AUC and $C_{max}$ respectively). The major parameters, AUC and $C_{max}$ met the criteria of KFDA for bioequivalence although $T_{max}$ did not meet the criteria of KFDA (1998 year) for bioequivalence, indicating that Onfran tablet is bioequivalent to Zofran tablet. But in another ANOVA test AUC did not meet the criteria of KFDA (2002) for bioequivalence but $C_{max}$ met the criteria of KFDA (2002 year) for bioequivalence.or bioequivalence.equivalence.equivalence.equivalence.