• 센서학회지
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• 제24권1호
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• pp.41-46
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• 2015

In this work, pure hierarchical ZnO structure was prepared using a simple hydrothermal method, and Ag nanoparticles doped hierarchical ZnO structure was synthesized uniformly through photochemical route. The reduced graphene oxide (rGO) has been synthesized by typical Hummer's method and reduced by hydrazine. Prepared Ag/ZnO nanostructures are uniformly dispersed on the surface of rGO sheets using ultrasonication process. The synthesized samples were characterized by SEM, TEM, EDS, XRD and PL spectra. The average size of prepared ZnO microspheres was around $2{\sim}3{\mu}m$ and showed highly uniform. The average size of doped-Ag nanoparticles was 50 nm and decorated into ZnO/rGO network. The $C_2H_2$ gas sensing properties of as-prepared products were investigated using resistivity-type gas sensor. Ag/ZnO-rGO based sensors exhibited good performances for $C_2H_2$ gas in comparison with the Ag/ZnO. The $C_2H_2$ sensor based on Ag/ZnO-rGO had linear response property from 3~1000 ppm of $C_2H_2$ concentration at working temperature of $200^{\circ}C$. The response values with 100 ppm $C_2H_2$ at $200^{\circ}C$ were 22% and 78% for Ag/ZnO and Ag/ZnO-rGO, respectively. In additions, the sensor still shows high sensitivity and quick response/recovery to $C_2H_2$ under high relative humidity conditions. Moreover, the device shows excellent selectivity towards to $C_2H_2$ gas at optimal working temperature of $200^{\circ}C$.

• 대한화학회지
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• 제39권9호
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• pp.734-740
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• 1995

Xanthomonas palargonii 5S rRNA의 일차구조 및 이차구조를 결정하고 에틸니트로소 우레아, Pb2+, 황산 이메틸 , 피로탄산 이에틸 들의 화학 탐침과 몇 가지 효소 탐침을 사용하여 고차원 구조를 분석하였다. 에틸니트로소 우레아는 삼차 상호작용에 관련되는 포스포디에스테르 결합을 조사하는데 사용되었다. Mg2+이 있을 때 에틸니트로소 우레아에 의한 변형에 대해서 저항성이 있는 자리는 불안정한 d 나선의 Nucleotides G72, A73, G75, A78, G98, G100, A101 들, c고리의 C36, C37, C39, C41들, 그리고 C 줄기의 A29, G33 들이다.이러한 결과와 Pb2+에 의한 가수분해 반응과 화학 탐침과 효소 탐침을 사용하여 얻은 결과들을 종합해 봄으로써 5S 의 b-C 구역과 d 나선 구역은 5S rRNA의 삼차 상호작용에서 돌쩌귀의 구실을 할 것으로 추정할 수 있었다.

• 한국미생물·생명공학회지
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• 제32권2호
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• pp.190-194
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• 2004

The gene product of dctD (DctD) activates transcription from the dctA promoter regulatory region by the $\sigma^{54}$ -holoenzyme form ofRNA polymerase ($E\sigma^{54}$ ) in Rhizobium meliloti and R. leguminosarum. The Escherichia coli integration host factor (IHF) stimulated DctD-mediated activation from the dctA promoter regulatory region of R. leguminosarum but not R. meliloti. In the absence of UAS, IHF inhibited DctD-mediated activation from both of these promoter regulatory regions. IHF also inhibited activation from R. leguminosarum dctA by nitrogen regulatory protein C (NtrC), another activator of $E\sigma^{54}$ but not by one which lacks a specific binding site in this promoter regulatory region. IHF, however, stimulated NtrC-mediated activation from the R. meliloti dctA promoter. Upon removal of the UAS, IHF inhibited NtrC-mediated transcription activation from the R. meliloti dctA promoter regulatory region. These data suggest that IHF likely faciliates productive contacts between the activators NtrC or DctD and $E\sigma^{54}$ to stimulate activation from dctA promoter.

• 설비공학논문집
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• 제11권1호
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• pp.61-72
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• 1999

The present study experimentally investigated the effect of refrigeration lubricant on the heat transfer performance in the straight sections and U-bend of a microfin tube evaporator by using R-22/mineral oil and R-407C/POE oil. The apparatus consisted of test section with U-bend, preheater, condenser, oil injection and sampling devices, magnetic pump, mass flow meter etc. The experimental parameters were oil concentration of 0 to 5 wt%, inlet quality of 0.1 to 0.5, mass flux of 219 and $400kg/m^2s$ and heat flux of 10 and $20kW/m^2$. The effects of parameters on the heat transfer coefficients were large in the order of inlet quality, mass flux and heat flux as oil concentration got increased. As oil concentration was increased, heat transfer coefficients were continuously decreased for R-22 and increased by 3% up to the concentration of 1% and then decreased for R-407C under the condition of large inlet quality, and small mass flux and heat flux. But, the heat transfer coefficients were increased up to the concentration of 3% and then decreased for both R-22 and R-407C refrigerants under the opposite conditions. The variation of enhancement factors for R-407C was under 50% of that for R-22 and the variation with respect to the positions in the test section was small. The pressure drops were increased for both R-22 and R-407C refrigerants as oil concentration was increased. The pressure drops for R-407C were smaller by the maximum of 18% than those for R-22.

• 한국동물위생학회지
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• 제37권3호
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• pp.157-164
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• 2014

Clostridium chauvoei is the etiologic agent of blackleg, a high mortality rated disease infection mainly cattle. In the present study, the partial sequences of 16S rRNA and flagellin gene of C. chauvoei isolated in Jeonbuk, Korea were determined and compared with those of reference strain. Oligonucleotide primers were designed to amplify a 811 bp fragment of 16S rRNA gene and 1229 bp fragment of flagellin gene. Sequencing analysis of 16S rRNA gene showed high homology to the reference strains ranging 82.3% to 100%, while flagellin gene were different from published foreign clostridia, showing 98.7% to 72.0% nucleotide sequence homology. Phylogenetic analysis based on 16S rRNA gene revealed the close phylogenetic relationship of C. chauvoei and C. septicum in cluster I, which includes C. carnis, C. tertium, C. quinii, C. celatum, C. perfringens, C. absonum, C. botulinum B. Phylogentic analysis also revealed that flagellin gene formed a single cluster with C. chauvoei, C. septicum, C. novyi A, C. novyi B, C. tyrobutylicum, C. acetobutylicum. The genetic informations obtained from this study could be useful for the molecular study of C. chauvoei.

• 한국구조물진단유지관리공학회 논문집
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• 제18권6호
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• pp.50-59
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• 2014

본 논문에서는 경북 구미시 봉곡천에 최근 건설된 다기능어도를 대상으로 SAP2000으로 구조 해석하기 위한 변수를 R/C Slab, R/C+S/C Slab 및 지하이동통로 규격(가로${\times}$세로)을 $1m{\times}0.2m$, $1m{\times}0.4m$, $1m{\times}0.6m$와 유속 0.8m/s, 1.2m/s, 1.6m/s으로 구분하여 해석한 결과와 봉곡천 설계식을 비교하여 안정성을 검토하였다. 봉곡천의 설계식 보다 R/C+S/C Slab 타입이 지하이동통로 출구부는 휨모멘트와 최대응력은 각각 28~54%, 26~50%, 측벽은 24~47%, 17~31%, 상부슬래브인 경우도 10~27%, 4~20% 적게 나타났다. 따라서 최대응력과 휨모멘트가 R/C+S/C Slab 타입이 구조 안정성이 확보되는 것으로 나타났기 때문에 지하통로는 휨모멘트와 최대 응력이 27%, 25%, 측벽은 24%, 15% 상부슬래브는 14%, 10%의 보완이 요구되는 것으로 판단된다. 이러한 결과는 지하이동통로 규격이 봉곡천 규격과 동일한 $1m{\times}0.4m$일 때가 $1m{\times}0.2m$, $1m{\times}0.6m$ 보다 안정성이 가장 유리한 것으로 확인되었다. 또한 해석 및 분석 결과를 근거로 다기능어도 시공 시 기본 자료로 활용이 기대된다.

• Journal of Ginseng Research
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• 제27권2호
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• pp.66-71
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• 2003

천연생물자원으로부터 적변억제 효과가 우수한 ICPE-P$_{107}$R와 ICPE-C$_{105}$R을 선발하였고 실험 포장에서 1년생 묘삼을 식재하여 2년간에 걸친 인삼의 적변현상 억제 효과를 검증하였다. 그 결과 방제물질과 보조제를 조합한 방제물질 처리구에서 인삼의 생장이 우수하였는데 특히 ICPE-P$_{107}$R와 ICPE-C$_{105}$R에서는 건물중이 대조구의 1.15g dry wt. x ginsen$^{-1}$보다 더 많은 1.99g dry wt. 와 1.47g dry wt. 로 생장 증가를 나타내었다. 또한 적변 억제 효과에서 방제물질 ICPE-P$_{107}$R 와 ICPE-C$_{105}$W가 각각 20%, 13.3%로 대조구 58%에 비해 놀라울 정도로 높은 방제 효과를 나타냈으며 ICPE-C$_{105}$R, ICPE-C$_{105}$P에서도 16.7% 18.2%로 비교적 양호한 효과를 나타내었다. 총 ginenoside의 함량과 각 ginsenoside의 함량역시 모든 방제제 처리구에서 대조구보다 공히 더 높은 함량을 나타내었다. 특히 ICPE-C$_{105}$R, ICPE-P$_{107}$R 처리구에서는 대조구보다 조사한 ginsenoside의 종류와 총 함량에 있어서 모두 월등하게 더 높았다.

• 한국구조물진단유지관리공학회 논문집
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• 제25권4호
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• pp.83-91
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• 2021

본 연구에서는 기존 철근콘크리트 (R/C) 구조체와 내진보강 부재의 접합부의 성능을 향상시키기 위해서 접합부에 탄성패드를 가지는 새로운 H형강 철골프레임 내부접합형 내진보강공법 (H-section Steel Frame with Elastic Pad, HSFEP)을 제안하였다. HSFEP 시스템은 필요 내진보강량 산정이 간편한 내력향상형 보강공법으로서, 전단파괴가 발생할 가능성이 매우 높은 비내진상세를 가지는 중·저층 R/C 건축물에 적합한 공법이다. 본 연구에서 제안한 HSFEP 내진보강공법의 유용성을 검증하기 위하여 비내진상세를 가지는 국내 R/C 건축물을 바탕으로 실물 2층 골조 실험체를 제작하여 유사동적실험을 수행하여 최대지진응답 하중 및 변위, 지진피해정도를 중심으로 내진보강효과를 검토하였다. 실험결과 본 연구에서 개발한 HSFEP 내부접합형 내진보강법은 접합부성능이 개선되었으며, 효과적으로 수평극한내력을 증진시킴과 동시에 대지진 입력 시에도 지진응답변위를 매우 효과적으로 억제시켰다.

• 한국환경보건학회지
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• 제28권5호
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• pp.28-34
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• 2002

Antigenicity of Rhodotrula rubra isolated from pulmonary tissue of pulmonary tuberculosis patients was studied by means of agglutination reaction with R. rubra whole cell antiserum. And the serological reactivity of crude polyfac charide from R. frubra, Candida albicans, Candida tropicalis, Candida, glabrata, and Saccharomyces cerevisiae ATCC 26603 with antiserum to R. rubra whole cell was studied by means of immunodiffusion test. R. rubra showed stationary phase after 48h when it was cultured in GYEP broth. While agglutinogen titer was 1:64 at lag phase, agglutinogen titer was 1 :256 after 20h. After growth of R. rubra on different 11 media, nutritional environment showed similar agglu-tination reartivity. The agglutinogen titer of C. albicans, C. tropicalis, C. giabrata, which were isolated from patient's expectoration, to R. rubra antiserum by means of agglutination reaction were 1:16, respectively. But, Sacch. cervisiae ATCC26603 was negative. Those results were lower than that of R. rubra agglutinogen titer 1:256. As a result of immu-nodiffusion test with crude polysaccharide extracted from cell wall of R. rubra, C. albicans, C. tropicalis, C. glabrata, Sacch. cervisiae ATCC26603, precipitin line was found only with R. rubra, of which antibody titer was 8.

• 대한수학회보
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• 제31권1호
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• pp.105-113
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• 1994

In the course of study of dendroids, Czuba [3] introduced a notion of $R^{i}$ -continua which is a generalization of R-arc [1]. He showed a new class of non-contractible dendroids, namely of dendroids which contain an $R^{i}$ -continuum. Subsecequently Charatonik [2] attempted to extend the notion into hyperspace C(X) of metric continuum X. In so doing, there were some oversights in extending some of the results relating $R^{i}$ -continua of dendroids for metric continua. In fact, Proposition 1 in [2] is false (see example C below) and his proof of Theorem 6 in [2] is not correct (Take Example 4 in [4] with K = [e,e'] as an $R^{1}$-continuum of X and work it out. Then one seens that K not .mem. K as he claimed otherwise.). The aims of this paper are to introduce a notion of w-regular convergence which is weaker than 0-regular convergence and to prove that the w-regular convergence of a sequence {Xn}$^{\infty}$$_{n=1}$ to $X_{0}$ of subcontinua of a metric continuum X is a necessary and sufficient for the sequence {C( $X_{n}$)}$^{\infty}$$_{n=1}$ to converge to C( $X_{0}$ ), and also to prove that if a metric continuum X contains an $R^{i}$ -continuum with w-regular convergence, then the hyperspace C(X) of X contains $R^{i}$ -continuum.inuum.uum.