• 환경생물
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• 제17권4호
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• pp.421-426
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• 1999

공단 주변 지역에 형성되어 있는 초지 군락의 구조, 종 다양성 및 토양 특성을 조사하였다. 조사지역은 상관에 의해 쑥(Artemisia princeps var. orientalis)군락, 미국자리공(Phytolacca americana)군락, 참억새(Miscanthus sinensis)군락으로 구분되었다. 1999년 8월에 조사한 각 식물군락의 지상부 현존량은 쑥군락 5,645g/$m^2$, 미국자리공군락 2,827g/$m^2$, 참억새군락 9,048g/$m^2$으로 다른 지역의 초지에 비해 현저히 높은 것으로 나타났다. 군락의 종 다양성은 쑥군락, 미국자리공군락 그리고 참억새군락이 각각 1.03, 0.54, 0.26으로 매우 낮았다. 초지군락 토양의 pH는 4.4~4.5 범위이었으며, 상층토의 유기물함량은 11.1~15.7%, 전질소 함량은 2.5~3.7 mg/g, 유효인은 52.7~61.2 $\mu$g/g, 황은 357.3~511.4 $\mu$g/g, 가용성 황은 17.8~25.2 $\mu$g/g, 치환성 칼륨, 칼슘, 마그네슘은 각각 15.6~24.6 $\mu$g/g, 25.4~156.2 $\mu$g/g, 4.5~11.1 $\mu$g/g 의 범위이었다. 본 조사지역 초지군락의 구성종은 대부분 토양 부영양화의 지표종이었다.

• 수산해양기술연구
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• 제60권2호
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• pp.101-113
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• 2024

This study investigated the species composition and community structure of aquatic organisms captured using coastal beam trawling in Gomso Bay, Jeollabuk-do, from January to December 2022. Throughout the experimental period, a total of 20,246 individuals belonging to 94 marine species were captured, with a combined biomass of 602,828 g. Fish exhibited the highest abundance, comprising 56 species, followed by crustacea (21 species), bivalvia (8 species), cephalopoda (5 species), gastropoda (3 species), and holothuroidea (1 species). The dominant species was Leiognathus nuchalis, constituting 14.0% of the total individuals, followed by Portunus trituberculatus at 12.1%, Oratosquilla oratoria at 10.4%, Crangon hakodatei at 9.9%, and Metapenaeus joyneri at 7.9%. The diversity index ranged from 1.72 to 2.55, with the lowest diversity observed in March and the highest in July. Cluster analysis based on species composition of the 27 most common species showed that aquatic organisms were divided into three groups: spring and summer organisms (Group A) and summer organisms (Group B) and autumn and winter organisms (Group C).

• Fibers and Polymers
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• 제2권3호
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• pp.141-147
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• 2001

The effect of compositions of isophorone diisocyanate (IPDl)/4.4'-diphenylmethane diisocyalate (MDI) and polypropylene oxide diol (PPG, $M_w$: 3000)/1,4-butane diol (BD) on the properties of UV-cured polyurethane acrylate films based on 2-hydroxyethyl acrylate (HEA) was examined. UV-curable polyurethane acrylates were formulated from the prepolymer. trimethylol propane triacrylate (TMPTA) as a reactive diluent, and 1-hydroxycyclohexyl ketone (Irgacure 184) as a photoinitiator. Dynamic mechanical thermal properties and elastic properties of UV-cured polyurethane acrylates was fecund to depend on the chemical composition of IPDl/MDl and PPG/BD. As the BD content increased, the tensile storage modulus of all series samples increased significantly. The storage modulus increased in the order of samples A (IPDI based samples)> samples B (IPDI/MDl (7/3 molar ratio) based samples) > samples C (IPDI/MDl (5/5 molar ratio) based samples at the same composition. Two distinct louts modulus peaks for all samples are observed owing to the softs segment glass transition temperature ($T_gh$) and hard segment glass transition temperature ($T_gh$). The difference between $T_gh$, and $T_gh$, (Δ$T_g$) increases in the order of A > B > C at the same composition. In cycle test, the initial onset strain (%) was found to decrease with increasing BD content in PPG/BD and with increasing MDI content in IPDI/MDl.

• 수산해양교육연구
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• 제27권1호
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• pp.273-283
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• 2015

This study was carried out to examine the species composition and community structure of benthic marine algae at the subtidal zones of Daepo, Wolpyeong, Wimi and Jigwido in south Jeju, Korea from March to December 2009. Total 87 species including 14 green algae, 23 brown algae, and 50 red algae were collected and identified. Among these species, 9 species were found throughout the year. The dominant species which contributed significantly to the total biomass were Ecklonia cava, Undaria pinnatifida, Peyssonnelia capensis, Cladophora wrightiana, Sargassum serratifolium, Grateloupia angusta, Codium coactum, Plocamium cartilagineum, and Sargassum macrocarpum. The average seaweed biomass was 7,578.2 g wet weight $m^{-2}$ and maximum biomass was recorded seasonally in spring ($9,627.6g\;m^{-2}$), while minimum was recorded in autumn ($5,963.0g\;m^{-2}$), by sites maximum biomass Jigwido ($12,889.9g\;m^{-2}$), while minimum was recorded in Daepo ($5,403.8g\;m^{-2}$). The seasonal and regional flora were investigated as six functional groups. A coarsely branched form was the most dominant functional group constituting from 42.9~52.8% of the total flora. Ecological state group (ESG) II, as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, consisted of 31~59 species, constituting 77.5~84.9%.

• Macromolecular Research
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• 제16권5호
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• pp.404-410
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• 2008

In order to obtain 'value added products' from polypropylene (PP)/waste ground rubber tire powder (WGRT) composites, PP/WGRT microcellular foams were prepared via supercritical carbon dioxide. The effects of blend composition and processing condition on the cell size, cell density and relative density of PP/WGRT micro-cellular composites were studied. The results indicated that the microcellular structure was dependent on blend composition and processing condition. An increased content of waste ground rubber tire powder (WGRT) and maleic anhydride-grafted styrene-ethylene-butylene-styrene (SEBS-g-MA) reduced the cell size, and raised the cell density and relative density, whereas a higher saturation pressure increased the cell size, and reduced the cell density and relative density. With increasing saturation temperature, the cell size increased and the relative density decreased, whereas the cell density initially increased and then decreased.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.709-715
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• 1999

A series of antifungal compounds were obtained from the methanol extract of the mycelium from marine actinomycetes M428 which was identified as a Stereptomyces species by fatty acid composition and biochemical characteristics. These compounds were purified by combined chromatographic techniques and the structures were characterized with spectroscopic methods including 1D and 2D NMR, and mass spectrometry as sn-l lysophosphatidyl inositols. The side chains were established by chemical degradation followed by GC analysis to be 14-methyl pentadecanoic acid (iso-palmitic acid, i-C16:0, compound A) and 13-methyl tetradecanoic acid (iso-pentadecanoic acid, i-C15:0, compound B). These compounds displayed highly selective antifungal activity against C. albicans with MIC values of $5{\;}\mu\textrm{g}/ml$ (compound A) and $2.5{\;}\mu\textrm{g}/ml$ (compound B), while it had almost negligible antibiotic activity against E. coli and P aerogenosa with MIC value higher than $50{\;}\mu\textrm{g}/ml$ and no cytotoxic activities against human myeloma leukemia K562 ($IC_{50}>100{\;}\mu\textrm{g}/ml$).

• 한국자기학회지
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• 제18권5호
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• pp.190-194
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• 2008

FePd 합금박막을 스퍼터링법으로 초격자 박막의 형태로 제작하고 기판온도, 조성변화에 따른 미세구조 및 자기적 특성을 분석하였다. FePd 합금박막의 규칙화를 위한 열처리 온도를 FePt의 열처리 온도에 비해 $150^{\circ}C$ 낮추는데 성공하였다. 또한 FePd 규칙화 합금 박막은 화학양론적 조성일 때 장범위 규칙도는 가장 높은 값을 가졌으며(Fe조성 50 at.%, S = 0.79), 자기이방성 에너지는 Fe 조성이 약간 낮은 조성에서(Fe조성 48 at.%, $K_U=1.6{\times}10^7\;erg/cm^3$) 가장 높은 값을 나타내었다. 이것은 FePd 합금박막의 조성이 장범위 규칙도와 수직자기이방성에 직접적으로 영향을 미친다는 것을 나타낸다.

• 한국재료학회지
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• 제10권3호
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• pp.218-222
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• 2000

W에 소량의 Ti를 첨가하여 그 함량 변화에 따른 X-선 마스크 흡수체용 W-Ti 박막의 물성을 연구하였다. W-Ti 박막은 DC magnetron sputtering system을 이용하여 증착하였다. Sputtering 증착시 증착압력의 증가에 따라 박막의 밀도는 감소하였으며 박막의 응력은 압축응력으로 바뀌었다. Ti 함량이 증가함에 따라 천이 압력 근방에서의 응력곡선의 기울기가 감소하였으며 천이 압력도 점차 낮아지는 경향을 보였다. Pure-W 시편의 경우 천이 압력이 약 6.5mTorr로 비교적 높았으며, 이 때 박막의 밀도는 $17.8g/\textrm{cm}^3$이었고 함량 6.5%에서 가장 낮은 천이 압력(4.3mTorr)을 보였으며, 이때의 박막 밀도는 $17.7g/\textrm{cm}^3$로 pure-W과 거의 차이가 없음을 알 수 있었다. SEM을 이용한 미세구조 분석결과 pure-W 박막은 원형의 주상정 조직을 보이고 있으며, Ti가 첨가된 W-Ti 박막의 경우에는 가늘고 긴 침상 모양을 가지는 주상정 조직을 형성하고 있다. 또한 이러한 침상조직은 Ti함량이 증가할수록 더욱 발달하고 있으며, AFM 분석결과 Ti 첨가 시편 모두 $18{\AA}$이하의 우수한 평균 표면 평활도를 나타내었다. 나타내었다.

• 수산해양기술연구
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• 제50권4호
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• pp.633-642
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• 2014

Monthly variation in abundance and species composition of the fishes were investigated based on specimens collected by gill net in coastal water of Yeosu from October, 2009 and February, May, August, 2010. The collected fishes were 1,529 individuals (183,840g) of the total, identified into 6 orders, 16 families and 24 species. The most dominant order fish was Perciformes comprised 9 species, 7 families, and followed Pleuronectiformes comprised 5 species, 3 families, Scorpaeniformes comprised 5 species, 2 families. These 3 orders constituted 81.1% of the total collected fish. During the study, most dominant species was Hexagrammos otakii accounted for 189 individuals (12.4%) of the total, followed by Lateolabrax japonicus 165 individuals (10.8%), Hexagrammos agrammus 154 individuals (10.0%). The fish was collected by a gill net in coastal water of Yeosu from October, 2009 and February, May, August, 2010, the diversity index of the fishes was 2.09~2.66, which was the highest in August, 2010 and the lowest in February, 2010. The evenness index of them was 0.84~0.89, which was the highest in August, 2010 and the lowest in February, 2010 and the richness index of them was 2.02~3.14, which was the highest in October, 2009 and the lowest in February, 2010. The analyzed species diversity index by the each stations was 2.47~2.66 and the evenness index was 0.84~0.90 and the richness index 2.99~3.37. The similarity of community structure per season was very high which was the least in spring and fall. In addition, the community structure was very similar in state 3 and 2 out of each stations.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.455-461
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• 2009

There is a significant amount of experimental evidence suggesting that polysaccharides from mushrooms enhance the host immune system by activating various mechanisms in immune cells, including macrophages. In this study, polysaccharides from Lentinus edodes were found to stimulate the functional activation of macrophages to secrete inflammatory mediators and cytokines and increase the phagocytotic uptake. The chemical properties of the stimulatory polysaccharides, CPFN-G-I, CPBN-G, and CPBA-G, were determined based on their monosaccharide composition, which mainly consisted of glucose and mannose. According to FT-IR and GC/MS, the structure of CPFN-G-I, purified from the fruiting body of L. edodes, was found to consist of a $\beta$-1,6-branched-$\beta$-1,4-glucan, whereas CPBN-G and CPBA-G, purified from the liquid culture broth, were found to be composed of a heteromannan. The configuration of the p-linkage and triple helical conformation of each polysaccharide were confirmed using a Fungi-Fluor kit and Congo red, respectively.