• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3771-3776
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• 2010

The dynamics of the $CN^-$-ligated ferric cytochrome c (CytcCN) in $D_2O$ at 283 K following Q-band photoexcitation at 575 nm was observed using femtosecond time-resolved vibrational spectroscopy. The equilibrium vibrational spectrum of the CN stretching mode of CytcCN shows two overlapping bands: one main band (82%) at $2122\;cm^{-1}$ with $23\;cm^{-1}$ full width at half maximum (fwhm) and the other band (18%) at $2116\;cm^{-1}$ with $7\;cm^{-1}$ fwhm. The time-resolved spectra show bleaching of the CN fundamental mode of CytcCN and two absorption features at lower energies. The bleach signal and both absorption features are all formed within the time resolution of the experiment (< 200 fs) and decay with a life time of 1.9 ps. One transient absorption feature, appearing immediately red to the bleach signal, results from the thermal excitation of low-frequency modes of the heme that anharmonically couple to the CN fundamental mode, thereby shifting the CN mode to lower energies. The shift of the CN mode decays with a lifetime of 2 ps, equivalent to the time scale for vibrational cooling of the low-frequency heme modes. The other transient absorption feature, which is 3.3 times weaker than the bleach signal and shifted $27\;cm^{-1}$ toward lower energies, is attributed to the CN mode in an electronically excited state where the CN bond is weakened with a lowered extinction coefficient. These observations suggest that photoexcited CytcCN mainly undergoes ultrafast radiationless relaxation, causing photo-deligation of $CN^-$ from CytcCN highly inefficient. As also observed in $CN^-$-ligated myoglobin, inefficient ligand photodissociation might be a general property of $CN^-$-ligated ferric hemes.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.106-112
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• 2011

This study is to investigate the effect of an aromatic content in high cetane number (CN) fuels on exhaust emissions under low temperature diesel combustion, which expands the previous research about an aromatic content in low CN fuels. A 1.9L common rail direct injection diesel engine was run at 1500 rpm 2.6 bar BMEP with four fuel sets: an aromatic content of 20% (A20) or 45% (A45) with CN30, i.e. low CN fuels, and CN55, i.e. high CN fuels. Given experimental conditions, the trend of exhaust emissions in high CN fuels was inconsistent with that of low CN fuels which all produced nearly zero smoke but higher NOx for the high aromatic fuel (CN30-A45). For high CN fuels, however, the low aromatic fuel (CN55-A20) produced lower smoke than the high one (CN55-A45) while NOx was similar to each other. The cause of this discrepancy between high CN and low CN fuels is unclear whether it comes from that CN may be a dominant factor to govern exhaust emissions rather than an aromatic content or that the actual CN value of CN55-A45 is lower than CN55-A20. More decent fuel matrix should be prepared and further experiments are needed to confirm it.

• 한국가스학회지
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• 제19권3호
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• pp.44-48
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• 2015

중회귀분석을 사용하여 혼합연료가스의 탄화수소 이슬점(DT)을 구하였다. QSDR(Quantitative Structure Dew-point Relationship)에서 주요한 설명인자는 혼합연료가스 중의 평균탄소수(CN : carbon number)와 혼합연료가스 중의 가지달린 이성질체 비율(BI : the ratio of the branched isomer)이었다. 혼합연료가스의 압력을 100 kPa ~ 500 kPa로 변화시키며 QSDR을 수행한 결과는 다음과 같다. $$DT(^{\circ}C)=-683.1+1224.98CN-898.01CN^2+308.58CN^3-49.56CN^4+3.02CN^5-12.42BI$$ (at 100 kPa, $$R_{adj}{^2}=0.99$$) (1) $$DT(^{\circ}C)=-745.2+1351.66CN-978.1CN^2+332.7CN^3-52.96CN^4+3.20CN^5-12.84BI$$ (at 200 kPa, $$R_{adj}{^2}=0.99$$) (2) $$DT(^{\circ}C)=-795.4+1457.1CN-1051.1CN^2+357.53CN^3-57.07CN^4+3.46CN^5-13.10BI$$ (at 300 kPa, $$R_{adj}{^2}=0.99$$) (3) $$DT(^{\circ}C)=-868.1+1608.4CN-1156.0CN^2+393.38CN^3-63.06CN^4+3.85CN^5-13.39BI$$ (at 500 kPa, $$R_{adj}{^2}=0.99$$) (4) 혼합연료 중의 평균탄소수의 값이 감소하거나 비점이 낮은 가지달린 이성질체의 비율이 증가할 때 탄화수소 이슬점이 낮아진다. 이 결과는 중회귀분석에 의하여 얻어진 탄화수소이슬점과 상용프로그램 VMGSim을 통하여 계산된 값과 유사하였다.

• 한국환경과학회지
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• 제29권1호
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• pp.95-108
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• 2020

Silver nanoparticles were loaded onto g-C₃N₄ (CN) with a nanoroll-type morphology (Ag/CN) synthesized using a co-polymerization method for highly selective conversion of toxic nitrobenzene to industrially-valuable aminobenzene. Scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM) images of Ag/CN revealed the generation of the nanoroll-type morphology of CN. Additionally, HRTEM analysis provided direct evidence of the generation of a Schottky barrier between Ag and CN in the Ag/CN nanohybrid. Photoluminescence analysis and photocurrent measurements suggested that the introduction of Ag into CN could minimize charge recombination rates, enhancing the mobility of electrons and holes to the surface of the photocatalyst. Compared to pristine CN, Ag/CN displayed much higher ability in the photocatalytic reduction of nitrobenzene to aminobenzene, underscoring the importance of Ag deposition on CN. The enhanced photocatalytic performance and photocurrent generation were primarily ascribed to the Schottky junction formed at the Ag/CN interface, greater visible-light absorption efficiency, and improved charge separation associated with the nanoroll morphology of CN. Ag would act as an electron sink/trapping center, enhancing the charge separation, and also serve as a good co-catalyst. Overall, the synergistic effects of these features of Ag/CN improved the photocatalytic conversion of nitrobenzene to aminobenzene.

• 천문학회지
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• 제38권2호
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• pp.23-31
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• 2005

CN and CH band strengths for fourteen bright giants in the globular cluster M71 have been measured from archival spectra obtained with the Multiple Mirror Telescope. Adding the collected. data from the literature we confirm a bimodality of CN distribution on the red giant branch and the honzontal branch, and CN-CH anti-correlations on the lower giant branch and horizontal branch. However a CN-CH anti-correlation on the upper red giant branch is not quite clear as those of other branches. The small number If statistics could not be excluded as a possible cause. To confirm this, a greater number of sample stars are needed. We also confirm that the ratio of CN-strong to CN-weak stars is quite different from that in 47 Tuc, although the anti-correlation between CN and CH bands, the bimodality of the CN distribution, and the spatial distribution of CN stars in M71 are found to be similar to those III 47 Tuc.

• 한국물환경학회지
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• 제26권4호
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• pp.590-597
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• 2010

NRCS Curve Number (CN) method is widely used for practical purposes in the field by engineers and researchers to calculate direct runoff from total rainfall. However, CN is obtained from antecedent moisture condition and soil characteristics and so it has some problems due to its uncertainty. Therefore this study estimated CN of a watershed using asymptotic CN method which can estimate CN by rainfall and runoff data and compared the result with representative CN given by WAMIS. And we performed runoff simulation for rainy season of Bocheong stream by CN regression equation. From the result, we showed that it could be more reasonable to simulate direct runoff using watershed CN regression equation than WAMIS CN. Furthermore, we knew that the equation is more sensitive to small rainfall event.

• BMB Reports
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• 제41권6호
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• pp.455-460
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• 2008

Calcineurin (Cn) is a serine/threonine phosphatase implicated in a wide variety of biological responses. To identify proteins that mediate Cn signaling pathway effects, we used yeast two-hybrid assays to screen for Cn interacting proteins, discovering a protein encoded by the gene, cnp-2 (Y46G5A.10). Utilizing serially deleted forms of Cn as baits, we demonstrated that the catalytic domain of Cn (TAX-6) binds with CNP-2, and this physical interaction was able to be reconstituted in vitro, supporting our yeast two-hybrid results. cnp-2 is a nematode-specific novel gene found in C. elegans as well as its closest relative, C. briggsae. CNP-2 was strongly expressed in the intestine of C. elegans. To study the function of cnp-2, we performed cnp-2 RNAi knock-down and characterized phenotypes associated with Cn mutants. However, no gross defects were revealed in these RNAi experiments. CNP-2 was proven to be a Cn binding protein; however, its role remains to be elucidated.

• 한국수자원학회논문집
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• 제34권6호
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• pp.735-743
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• 2001

CN법은 토지이용변화로 인한 수문학적 영향을 판단하는 경우, 그 적용성이 매우 우수한 것으로 알려져 있다. 본 연구에서는 토지이용의 공간적분포를 분석하기 위해 Landsat 다중분광영상을 이용하였다. 분석된 영상자료로부터 산지지역을 식생밀도에 따라 재분류하고, 식생밀도가 유출에 미치는 영향을 분석하기 위해 CN법을 이용하였다. 토양도의 종류(정밀토양도, 개략토양도)에 따라 분석한 결과, CN은 식생밀도에 따라서는 변화가 미미한 반면 토양 도의 종류에 따라서는 매우 큰 차이를 보였다. 실측강우·유출자료와 비교해본 결과 CN추정에 있어 정밀토양도를 사용하는 것이 향상된 결과를 보였다.

• 한국미생물·생명공학회지
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• 제38권4호
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• pp.373-378
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• 2010

우리술의 주질개선 및 현장 실용화기술을 개발하기 위해 술 담금의 기본재료인 누룩의 규격화 및 품질향상 연구가 필요하다. 이와 같은 요구에 부응하기 위해, 누룩에 생육하는 우수 양조미생물의 분리 발굴, 균주개량 및 보존관리 등 우리 고유의 양조미생물 자원을 확보하고 활용함으로써 다양한 종류의 누룩 제조가 가능할 것으로 여겨진다. 따라서, 본 연구는 충청지역에서 시판되고 있는 누룩을 수집하여 희석평판 배양법으로 174개 균주를 분리하여 효소활성 검정을 통하여 효소 활성이 높은 균주를 다수 분리하였다. 분리된 곰팡이를 대상으로 액화력 및 당화력 등의 효소학적 특성을 조사하였고, 선발된 활성균주의 동정을 위해 genomic DNA상의 ITS(Internal Transcribed Spacer) 부위의 염기서열을 분석한 결과 Aspergillus sp.(4균주), Rhizopus sp.(4균주), Rhizomucor sp.(2균주), Mycocladus sp.(2균주)으로 동정되었다. 밀기울을 사용한 고체배양에서 액화력, 당화력 및 산 생성능을 검토한 결과, Rhizopus sp. CN084, CN174, Aspergillus sp. CN161와 Mycocladus sp. CN042 균주가 효소활성이 높은 것으로 나타났으며 Aspergillus sp. CN010, CN161, Rhizopus sp. CN105, CN168 균주와 Rhizomucor sp. CN088 균주는 산 생성능이 우수한 것으로 나타났다. 따라서 이들 균주가 양조를 위한 누룩의 원료 균주로서 사용될 경우 단일 누룩제조가 가능할 것으로 판단되었다.

• 농업과학연구
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• 제20권1호
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• pp.56-67
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• 1993

본(本) 연구(硏究)는 유단백질(乳蛋白質)의 유전적표식(遺傳的標識)(genetic marker)를 유우(乳牛)의 유전적(遺傳的) 개량(改良)을 위한 유우등록 및 선발(選拔) 자료로 활용하고자 1992년 국립 종축원에서 사육증인 Holstein종 159두에서 각각 유즙 시료를 채취하여 Polyacrylarnide gel(PAGE)에 의한 전기영동방법에 의하여 ${\alpha}S1$-casein(${\alpha}S1$-CN) 및 ${\beta}$-casein(${\beta}$-CN), ${\kappa}$-casein(${\kappa}$-CN) 및 ${\beta}$-lactoglobulin(${\beta}$-LG)의 유전적(遺傳的) 다형(多型)을 분석(分析)하여 유전적(遺傳的) 변이체의 표현형(表現型), 유전자형(遺傳子型) 및 유전자빈도(遺傳子頻度)를 추정하고 이들 단백질의 유전적(遺傳的) 다형(genetic polyrnorphisms)과 유조성분과의 연관성을 분석(分析) 검토(檢討)하였다. 유단백질(乳蛋白質)인 ${\alpha}S1$-CN, ${\beta}$-CN, ${\kappa}$-CN 및 ${\beta}$-LG 유전좌위(遺傳座位)의 유전적(遺傳的) 변이체의 표현형(表現型) 분포의 관찰치와 기대치간에 유의적(有意的)인 차이가 인정 되지않아 이들 유전자(遺傳子)들이 유전적(遺傳的) 평형을 이루고 있는 것으로 사료되었다. 유단백질(乳蛋白質) 좌위(座位)의 유전자형(遺傳子型)을 분석(分析)한 결과(結果) ${\alpha}S1$-CN BB유전자형(遺傳子型), ${\beta}$-CN AA유전자형(遺傳子型), ${\kappa}$-CN AA유전자형(遺傳子型) 및 ${\beta}$-LG AB 유전자형(遺傳子型)의 출현빈도(出現頻度)가 각각 79.87%, 84.28%, 71.70% 및 49.10%로 높게 나타났다. 유단백질(乳蛋白質)의 유전자빈도(遺傳子頻度)에 있어서는 ${\alpha}S1-CN^B$와 ${\alpha}S1-CN^C$가 각각 0.899 및 0.101이었고, ${\beta}-CN^A$ 및 ${\beta}-CN^B$은 각각 0.921 및 0.079이었으며, ${\kappa}-CN^A$ 및 ${\kappa}-CN^B$은 각각 0.837 및 0.163이었고, ${\beta}-LG^A$ 및 ${\beta}-LG^B$은 각각 0.378 및 0.622이었다. 분산분석(分散分析) 결과(結果) 유단백질(乳蛋白質)의 유전자형(遺傳子型)들은 유조성분인 유지율, 단백질 함량 및 총 고형분 함량에서 유의적(有意的)인 연관성이 인정되었다. 유조성분 함량에 있어서는 ${\kappa}$-CN좌위(座位)의 BB유전자형(遺傳子型)은 유지율 및 유단백질(乳蛋白質) 함량에서 ${\kappa}$-CN좌위(座位)의 AA 및 AB 유전자형(遺傳子型)보다 유의적(有意的)으로 높게 나타났으며, ${\beta}$-LG좌위(座位)의 AA유전자형(遺傳子型)은 유지율에서 ${\beta}$-LG좌위(座位)의 AB 및 BB 유전자형(遺傳子型)보다 유의적(有意的)으로 높게 추정되었다. 이상의 연구결과(硏究結果)를 종합하여 볼때 유조 성분인 유지율 및 단백질함량을 높히기 위하여서는 ${\kappa}$-CN좌위(座位)의 BB 유전자형(遺傳子型)과 ${\beta}$-LG좌위(座位)의 AA 유전자형(遺傳子型)을 선발(選拔)하는것이 보다 유리할 것으로 생각되었다.