• 한국연초학회지
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• 제2권1호
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• pp.1-7
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• 1980

건조잎담배로부터 단백질로 간주되는 고분자 물질의 gel filtration column chromatography(Sephadex G-75), 투석 그리고 흡착 chromatography의 일종인 brushite column chromatography분리를 시도한 결과, 짙은 갈색의 고분자 물질을 얻었다. Sephadex column에 의한 분리 profile를 보면 분자량이 상이한 두종류의 갈색고분자 물질이 존재함을 확인하였고 brushite column의 분리 profile에 의하면 분자의 전자구조가 다른 두 종류의 고분자가 있음이 나타났다. Burley와 Hicks의 경우 단백질 분해효소에 의한 분해효과를 측정해본 결과, 가장 큰 분해효과를 보인 효소는 chymotrypsin으로 Burley에서 16-30%수준까지 분해현상을 나타내 주었으며 Hicks인 경우 38-57%까지 감소현상을 보여 주었다. Pepsin처리효과는 chymotrypsin처리구와 비슷한 수준을 보였으나 trypsin경우는 매우 낮은 분해현상을 나타냈다. 단백질 분해효소로 처리된 시료의 sephadex column분리 profile을 살펴보면, 분자량이 보다 큰 fraction의 경우 peak가 거의 완전하게 사라짐을 관찰할 수 있으나, 작은 분자량Peak는 약간의 감소현상만을 보여 주었다. 투석후의 갈색 고분자물질을 $300^{\circ}C$에서 연소시킨 경우, 연소전에 관찰할 수 없었던 강한 형광성 물질이 생성되었는데 TLC에 의한 분리후, 이 형광성 물질끈 흡수 스펙트라를 측정해 본 결과, 최대흡수 파장이 265. 275nm(benzene용매)로 나타났으며 스펙트럼 끈 모양이 polynuclear aromatic hydrocarbon(PAH) 계열 화합물의 것과 유사함을 보여 주었다.

• 한국강구조학회 논문집
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• 제19권1호
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• pp.53-65
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• 2007

새로운 형식의 기둥인 내부 구속 중공 콘크리트 충전 튜브 기둥(내부 구속 중공 CFT 기둥, ICH CFT column ; Internally Confined Hollow CFT Column)의 내진 성능 평가 실험을 수행하였다. 준정적 실험을 통하여 2가지 종류의 ICH CFT 기둥과 일반 중실 RC 기둥의 내진 성능을 비교 평가 하였다. 각각의 기둥 시험체에 대해 최대 하중과 변위의 관계를 측정하였으며, 이를 바탕으로 연성도, 소산에너지, 등가 감쇠비, 손상 지수가 계산되었다. 실험 결과 ICH CFT 기둥은 중실 RC 기둥에 비해 약 2배의 모멘트에 저항을 하였으며, 에너지의 흡수와 소산에서도 1.5배 정도의 성능을 보여주어, ICH CFT 기둥이 일반 중실 RC 기둥보다 더 뛰어난 성능을 가짐을 보여주었다.

• Journal of the Korean Wood Science and Technology
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• 제37권1호
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• pp.1-11
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• 2009

외장용 기둥재는 년중 사용환경에서 액상수와 직접 접촉할 수가 있으나, 이에 대한 연구는 그다지 많지 않다. 목재의 섬유방향에서 결합수와 자유수 확산계수를 포함한 수분확산계수를 측정하기 위해 상온에서 흡수실험을 실시하였다. 흡수성은 느릅나무, 까치박달나무, 헴록, 가문비나무, 라디에타 소나무, 고로쇠나무 순으로 크게 나타났다. Boltzmann 변환법으로 구한 확산계수는 저함수율에서 섬유포화점 부근까지 감소하다가 최대함수율 부근에서 급격히 증가하는 경향을 나타내었다. 함수율 변화에 따른 확산계수는 $10^{-10}{\sim}10^{-7}m^2/s$ 정도의 값을 나타내었다.

• Advances in concrete construction
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• 제4권3호
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• pp.161-172
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• 2016

An experimental investigation was carried out on the strength and behavior plain and fiber reinforced geopolymer concrete beam column joints and the results were compared with plain and steel fiber reinforced conventional concrete beam column joints. The volume fraction of fibers used was 0.5%. A total of six Geopolymer concrete joints and four conventional concrete joints were cast and tested under reversed cyclic loading to evaluate the performance of the joints. First crack load, ultimate load, energy absorption capacity, energy dissipation capacity stiffness degradation and moment-curvature relation were evaluated from the test results. The comparison of test results revealed that the strength and behavior of plain and fiber reinforced geopolymer concrete beam column joints are marginally better than corresponding conventional concrete beam column joints.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.665-672
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• 1997

In this paper, sixteen column specimens were tested under the concentrated and excentric load condition to examine the structural behavior of strengthened columns. 16 column specimens were divided into four groups. One group is not strengthened, the other three groups are strengthened by the materials : 1) steel plate, 2) carbon fiber sheet, and 3) glass fiber sheet, each group is composed of four specimens. As a result, strengthened columns have larger bearing capacity and energy absorption after ultimate load than unstrengthened columns. The column group strengthened with steel plate has the best bearing capacity among the strengthened column groups. Also, the columns strengthened with the carbon fiber sheet are similar to glass fiber sheet in bearing capacity. If necessary to strengthen columns in trouble, car should be taken to treat the joint between beam and column because of crack propagation in tension side.

• 한국막학회:학술대회논문집
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• 한국막학회 2002년도 제10회 하계 Workshop
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• pp.59-101
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• 2002

PVDF is good material for a hollow fiber membrane with high porosity and excellent hydrophobicity. Asymmetric PVDF hollow fiber membranes were prepared by the Loeb-Sourirajan phase inversion method. Asymmetric PVDF hollow fiber membranes could be controlled in pore size and porosity using various additives(LiCl, ZnCl$_2$) and internal coagulants (water, EtOH/water, and DMAc/water mixture). $CO_2$removal efficiency of asymmetric PVDF hollow fiber membranes was 1.2 times high than that of commercialized PP hollow fiber membranes at MEA 5wt% solution. $CO_2$flux of asymmetric PVDF hollow fiber membranes was 2.5 times higher than that of commercialized PP hollow fiber membranes. $CO_2$removal efficiency and absorption rate of asymmetric PVDF hollow fiber membranes were 30 times higher than those of packed column at absorbent $H_2O$. $CO_2$flux of asymmetric PVDF hollow fiber membranes at MEA 5wt% solution was 48 times higher than that of pure water. In the case of MEA 5wt% solution used as an absorbent, the $CO_2$absorption rate and removal efficiency of PVDF hollow fiber membrane were 2.3 times higher than that of a packed column.

• 천문학회보
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• 제40권2호
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• pp.52.3-53
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• 2015

It has been known that there is "dark gas" invisible either in 21-cm HI or 2.6-mm CO emission which are general tracers of atomic and molecular gas, respectively. Many researchers consider that the dark gas is "Dark Molecular Gas (DMG)" composed of CO-free $H_2$ in the intermediate zone between atomic and full-fledged molecular gas and that HCO+ and OH molecules are good tracers of the DMG since they can form in much lower $H_2$ column densities where CO does not. We have carried out HCO+ J=1-0 absorption observations toward nine bright extragalactic radio continuum sources using the KVN 21-m telescopes as single dishes. We detected HCO+ absorption lines toward two sources. We derive HCO+ and $H_2$ column densities or their limits, and discuss the implications of our results.

• 천문학논총
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• 제20권1호
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• pp.11-20
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• 2005

We present measurements of interstellar $H_2$ absorption lines in the continuum spectra of 54 early-type stars in the Galactic disk and halo and 3 stars in the Magellanic Clouds. The data were obtained with the Berkeley Extreme and Far-Ultraviolet Spectrometer (BEFS), part of the ORFEUS telescope, which flew on the ORFEUS-SPAS I and II space-shuttle missions in 1993 and 1996, respectively. The spectra extend from the interstellar cutoff at $912{\AA}$ to about $1200{\AA}$ with a spectral resolution of ${\sim}3000$ and statistical signal-to-noise ratios between 10 and 65. Assuming a velocity profile derived from optical observations (when available), we model the column densities N(J) of the rotational levels J = 0 through 5 for each line of sight. Our data reproduce the relationships among molecular and total hydrogen column density, fractional molecular abundance, and reddening first seen in Copernicusobservations of nearby stars (Savage et al. 1977). The results show that most of these molecular clouds have $H_2$ total column densities between $10^{15}cm^{-2}$ and $10^{21}cm^{-2}$, and kinetic temperatures from 21 K to 232 K, with average of 89 K, consistent with the result of Copernicus (Savage et al. 1977).

• BMB Reports
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• 제29권4호
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• pp.335-342
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• 1996

Porcine liver cysteinesulfinic acid decarboxylase was purified approximately 460-fold by means of ammonium sulfate fractionation and sequential column chromatographic separation with Sephadex G-100, DEAE-cellulose and hydroxylapatite. The enzyme has a flat pH profile with maximum activity occurring between pH 6.0 and 7.6. Pyridoxal 5'-phosphate must be present in all buffers used for purification procedures in order to stabilize the enzyme. Addition of sulfhydryl reagents such as 2-mercaptoethanol are also necessary to maintain maximum enzyme activity throughout purification. The absorption spectrum shows that cysteinesulfinic acid decarboxylase is a pyridoxal 5' -phosphate-containing protein. The major absorption is at 280 nm with two smaller absorption regions, one at 425 nm which is ascribed to a Schiffs base between pyridoxal phosphate and protein, and another at 325 nm which is thought to be due to the interaction of 2-mercaptoethanol with the Schiffs base. A number of divalent cations tested did not affect enzyme activity with the exception of mercury, copper, and zinc which are inhibitory. The partially purified enzyme has an apparent $K_m$ of 0.94 mM for cysteinesulfinate. Cysteic acid is a competitive inhibitor of the enzyme with a $K_i$ of 1.32 mM. The molecular weight of the enzyme was estimated to be about 79,600 by using Sephadex G-200 column chromatography.

• 한국해양환경ㆍ에너지학회지
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• 제13권1호
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• pp.47-52
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• 2010

근해에 설치되는 3차원 착저식 OWC 파력발전 챔버 구조물의 파 에너지 흡수효율과 구조물에 작용하는 1차 및 시간 평균 2차 파랑하중의 해석기법을 보였다. 쌍동형 OWC챔버 내부의 변동압력을 각 챔버의 내부 자유표면 경계조건에 도입하였으며 챔버 내부는 Rankine, 외부는 유한수심 3차원 자유표면 Green함수에 연계된 하이브리드 적분방정식을 사용하여 포텐셜 유동을 해석하였다. 수치실험 결과로서 3차원 착저식 OWC 파일럿 플랜트의 파력발전 1차변환 효율과 구조물에 작용하는 반복 및 지속적인 파랑하중을 제시하였다.