검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 204

        141.
        2019.04 서비스 종료(열람 제한)
        If deposits occur around the dam, it is possible to suspect the erosion of the internal material of the dam. Piping can occur if the dam internal material is eroded, and such piping can be a serious safety hazard for the dam. XRD and XRF were performed on the investigated sediments and dam core materials. XRD and XRF were carried out to confirm the constituent minerals and chemical composition of the samples. This method can be applied to detect the possibility of erosion of the material constituting the dam.
        142.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        비정질 Na-규산염과 Na-알루미노규산염 내의 Na 이온의 원자 환경을 규명하는 것은 Na을 포함하는 지구 내부 마그마의 물성을 규명하는 데 중요하다. 특히 Na 원자 환경의 규명을 통해 이동 물성에 매우 중요한 역할을 하는 Na과 산소와의 거리를 밝힐 수 있다. 본 연구에서는 23Na magic angle spinning (MAS) NMR을 이용하여 비정질 Na 규산염과 알루미노규산염의 Na 주변 원자 환경을 규명 하고자 하였고 Dmfit 프로그램을 이용한 시뮬레이션을 통해 δiso 값을 구했다. Dmfit 프로그램에서 제공하는 여러 모델 중 Q mas 1/2 모델과 CzSimple 모델을 사용하여 비정질 Na-알루미노규산염의 23Na MAS NMR 스펙트럼에 대해 시뮬레이션을 진행한 결과 Q mas 1/2 모델은 세 개의 피크로 CzSimple 모델은 하나의 피크로 실험값이 재현되는 것을 확인하였다. 조성에 따른 등방성 화학적 차폐(isotropic chemical shift, δiso)의 변화를 관찰한 결과 비정질 Na-규산염과 Na-알루미노규산염에서 SiO2의 함량이 증가할수록 δiso 값이 감소하는 경향성을 보였고 SiO2 함량이 고정되어 있는 조성에서는 Na2O의 함량이 높을수록 높은 δiso 값을 보였다. 이전 연구에서 실험적으로 얻어진 값들과 본 연구에서 시뮬레이션을 통해 얻은 값을 비교해본 결과 δiso 값은 Al / (Al + Si) 값과 양의 상관관계를 보이는 것이 확인되었고 CzSimple 모델에 비해 Q mas 1/2 모델을 사용하여 시뮬레이션 한 값이 실험값을 더 잘 재현하였다. 본 연구의 결과를 통해 1D 23Na MAS NMR 스펙트럼의 시뮬레이션을 통해 빠른 시간 내 Na 주변의 무질서도를 밝힐 수 있다는 것이 확인되었다.
        143.
        2018.07 KCI 등재 서비스 종료(열람 제한)
        This study observed particulate matter (PM2.5 and PM10) in the downtown area of Jeju City, South Korea, to understand the chemical composition of particulates based on an analysis of the water-soluble ionic species contained in the particles. The mass fraction of the ionic species in the sampled PM10 and PM2.5 was 44.3% and 42.2%, respectively. In contrast, in Daegu City and Suwon City, the mass fraction of the ionic species in PM2.5 was higher than that in PM10. The chloride depletion percentage of PM10 and PM2.5 in Jeju City was higher than 61% and 66%, respectively. The contribution of sea-salt to the mass of PM10 (5.9%) and PM2.5 (2.6%) in Jeju City was similar to that in several coastal regions of South Korea. The mass ratio of Cl- to Na+ in the downtown area of Jeju City was comparable to that in some coastal regions, such as the Gosan Area of Jeju Island, Deokjeok Island, and Taean City. The mass fraction of sea-salt in PM10 and PM2.5 was very low, and the concentration of sodium and chloride ions in PM10 was not correlated with those in PM2.5 (R2 < 0.2), suggesting that the effects of sea-salt on the formation of particulate matter in Jeju City might be insignificant. The relationship between NH4 + and several anions such as SO4 2-, NO3 -, and Cl-, as well as the relationship between the measurement and calculation of ammonium ion concentration, suggested that sea-salts may not react with H2SO4, and (NH4)2SO4 may be a major secondary inorganic aerosol component of PM2.5 and PM10 in Jeju City.
        144.
        2017.11 KCI 등재 서비스 종료(열람 제한)
        This study identified physical characteristics and aerosol particle sources of PM10 and PM2.5 in the industrial complex of Busan Metropolitan City, Korea. Samples of PM10, PM2.5 and also soil, were collected in several areas during the year of 2012 to investigate elemental composition. A URG cyclone sampler was used for collection. The samples were collected according to each experimental condition, and the analysis method of SEM-EDX was used to determine the concentration of each metallic element. The comparative analysis indicated that their mass concentration ranged from 1% to 3%. The elements in the industrial region that were above 10% were Si, Al, Fe, and Ca. Those below 5% were Na, Mg, and S. The remaining elements (1% of total mass) consisted of elements such as Ni, Co, Br and Pb. Finally, a statistical tool was applied to the elemental results to identify each source for the industrial region. From a principal components analysis (SPSS, Ver 20.0) performed to analyze the possible sources of PM10 in the industrial region, five main factors were determined. Factor 1 (Si, Al), which accounted for 15.8% of the total variance, was mostly affected by soil and dust from manufacturing facilities nearby, Factors 2 (Cu, Ni), 3 (Zn, Pb), and 4 (Mn, Fe), which also accounted for some of variance, were mainly related to iron, non-ferrous metals, and other industrial manufacturing sources. Also, five factors determined to access possible sources of PM2.5, Factor 1 (Na, S), accounted for 13.5% of the total variance and was affected by sea-salt particles and fuel incineration sources, and Factors 2 (Ti, Mn), 3 (Pb, Cl), 4 (K, Al) also explained significant proportions of the variance. Theses factors mean that the PM2.5 emission sources may be considered as sources of incineration, and metals, and non-ferrous manufacturing industries.
        145.
        2017.10 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study analyzes the chemical composition and thiobarbituric acid reactive substance levels of Godulbaegi (Youngia sonchifolia M.) depending on collection time. The moisture and crude fat content in leaf and root decreased, while crude fiber, crude protein, carbohydrate, and ash increased with increases in collection time. The mineral elements tended to increase in each sample with increases in collection time. The content of vitamin B increased as collection time increased. Vitamin C content was approximately five times higher in the leaves than that in the roots. Total amino acids in leaf and root increased considerably as collection time increased content of phenolic compounds in root were higher than that in the leaf and these contents increased. Antioxidant activity of Godulbaegi was higher in the root than in the leaf and increased as collection time increased.
        146.
        2017.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        A high resolution spectroscopic observation of the red supergiant star RM_1-390 in the Large Magellanic Cloud was made from a 3.6 m telescope at the European Southern Observatory. Spectral resolving power was R=20,000, with a signal-to-noise ratio S/N > 100. We found the atmospheric parameters of RM_1-390 to be as follows: the effective temperature Teff = 4,250 ± 50 K, the surface gravity log g = 0.16 ± 0.1, the microturbulent velocity vmicro = 2.5 km/s, the macroturbulence velocity vmacro = 9 km/s and the iron abundance [Fe/H] = -0.73 ± 0.11. The abundances of 18 chemical elements from silicon to thorium in the atmosphere of RM_1-390 were found using the spectrum synthesis method. The relative deficiencies of all elements are close to that of iron. The fit of abundance pattern by the solar system distribution of r- and s-element isotopes shows the importance of the s-process. The plot of relative abundances as a function of second ionization potentials of corresponding chemical elements allows us to find a possibility of convective energy transport in the photosphere of RM_1-390.
        149.
        2017.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        High-resolution spectroscopic observations of the eclipsing binary system RR Lyn were made using the 1.8 m telescope at the Bohuynsan Optical Astronomical Observatory in Korea. The spectral resolving power was R = 82,000, with a signal to noise ratio of S/N > 150. We found the effective temperatures and surface gravities of the primary and secondary components to be equal to Teff = 7,920 & 7,210 K and log(g) = 3.80 & 4.16, respectively. The abundances of 34 and 17 different chemical elements were found in the atmospheric components. Correlations between the derived abundances with condensation temperatures and the second ionization potentials of these elements are discussed. The primary component is a typical metallic line star with the abundances of light and iron group elements close to solar values, while elements with atomic numbers Z > 30 are overabundant by 0.5–1.5 dex with respect to solar values. The secondary component is a λ Boo type star. In this type of stars, CNO abundances are close to solar values, while the abundance pattern shows a negative correlation with condensation temperatures.
        150.
        2017.05 KCI 등재 서비스 종료(열람 제한)
        This study aimed to estimate the effects of replacing Mushroom By-Product (MBP) with Tofu By-Product (TBP) on the chemical composition, microbes, and rumen fermentation indices of Fermented Diets (FDs). The basal diet was formulated using MBP, TBP, rice bran, molasses, and inoculants. The MBP in the basal diet was replaced with TBP at 0, 5, and 10% on Dry Matter (DM) basis for the experimental diets. The experimental diets were fermented at 39°C for 144 h. Chemical composition, pH, microbes, and rumen fermentation indices of the FDs were analyzed. With increasing TBP replacement, crude protein content of FDs increased (L, P < 0.001), whereas crude ash content decreased (L, P = 0.002). Lactic acid bacteria and Bacillus subtilis contents in the TBP-replaced FDs were higher than those in the control (P < 0.05), whereas pH level and mold count were lower (P < 0.05). With increasing TBP replacement, in vitro rumen digestibility of DM (L, P = 0.053) and neutral detergent fiber (L, P = 0.024) increased, wheres rumen pH changed (P = 0.026) quadratically. Rumen total volatile fatty acid (L, P = 0.001) and iso-butyrate contents (Q, P = 0.003) increased with increasing TBP replacement. In conclusion, this study indicates that the replacement of MBP with TBP could improve the quality of FD.
        151.
        2017.05 서비스 종료(열람 제한)
        Background : F. fomentarius extracts have been recently reported to process immune-stimulatory and anti-inflammatory effects. In this study, we evaluated the anti-mutagenic effect of F. fomentarius ethanol extracts and the effective chemical components from the extract were analyzed by LC-Q-TOF. Methods and Results : F. fomentarius was extracted with 70% ethanol yielding a crude extract 6.8%. The crude extract was fractionated sequentially to diethyl ether, chloroform, dichloromethane, butanol and water with a yield of 43.9%, 2.958%, 6.8%, 21.6% and 25.5.%, respectively. The anti-mutagenic effect of F. fomentarius extract and its fractions was tested in Ames test by two type of Salmonella typhimurium (TA98 and TA100). Among the five fractions, diethyl ether has shown the highest and significant anti-mutagenic effect (98.3%, at 3,000 ㎍/plate concentration). Moreover, we investigated the chemical constituents of the extract using UPLC-Q-TOF. A total of 10 compounds such as flavonoids (velutin, 3, 4′,5-Trihydroxy-3′,7-dimethoxyflavanone) and fatty acids (γ-linoleic acid, stearic acid) and deterpenoid (kirenol) were tentatively identified with an accurate mass within 10 ppm mass error. Also, flavonoids and fatty acids were detected with higher rate than other compounds based on obtained chromatograms. Conclusion : We demonstrated that F. fomentarius extract and fractions have anti-mutagenic activity through Ames test. Furthermore, we will carry out isolation of each components from its fraction and use them to conduct additional anti-mutagenic test.
        152.
        2016.10 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this study, the morphological features and the chemical composition characteristics of Opuntia ficus-indica and Opuntia humifusa fruits were investigated. The length of minor and major axis, and weight of O. ficus-indica and O. humifusa fruits were compared as the morphological features. The characteristics of components such as color, moisture, crude protein, ash, fat, dietary fiber, mineral, and amino acids were evaluated. The values of O. ficus-indica fruits were higher than those of O. humifusa fruits in each morphological feature such as minor axis, major axis, and weight. According to the Hunter color index results, O. humifusa fruits showed higher values of L (lightness) and b (yellowness), whereas O. ficus-indica fruits showed higher value of a (redness). The ΔE value between two samples was 19.80. The O. ficus-indica fruits had higher carbohydrate content and lower content of crude ash than those of O. humifusa fruits. Both samples showed very high dietary fiber contents, and the major minerals were K and Ca. Glutamic acid was the major amino acids in both samples. In free amino acids contents, O. ficus-indica had higher tyrosine and lower glutamic acid level than those of O. humifusa fruits. γ-aminobutyric acid was found in both samples, whereas taurine was found in O. ficus-indica fruits only. Taken together, the morphological features and chemical quality of O. ficus-indica and O. humifusa fruits showed difference although both of them were originated from the same genus.
        153.
        2016.10 서비스 종료(열람 제한)
        Background : Cellular damage caused by excessive reactive oxygen species (ROS) and peroxynitrite (ONOO-) generations has been implicated in several human diseases. The present study was carried out to evaluate the in vitro ROS and ONOO- scavenging activities of Cirsium japonicum parts. Methods and Results : The dried Cirsium japonicum parts (whole plant, leaf, seed coat) were extracted by EtOH, at room temperature. In order to determine antioxidant activity of Cirsium japonicum parts, we were carried out ROS and ONOO- scavenging analyses. As a result , the IC50 in ROS scavenge were showed 203.99 ± 22.04 μg/ml, 174.44 ± 7.78 μg/ml, 86.77 ± 7.02 μg/ml. The IC50 in ONOO- scavenge were showed 15.68 ± 0.57 μg/ml, 12.99 ± 0.15 μ g/ml, 10.33 ± 0.19 μg/ml, respectively. Active compound content in C. japonicum was determined using a HPLC/UV, reverse-phase column with gradient elution program (water in 0.5% formic acid : acetonitrile = 100:0 to 0:100 for 45 min, 0.8 ml/min). UV detection was conducted at 340 nm. The content of apigenin was measured in whole plant (1.04±0.06 mg/g), leaf (0.91±0.02 mg/g), seed coat (33.33±0.93 mg/g). Conclusion : Each part of Cirsium japonicum was analyzed antioxidant activity and the content of apigenin with EtOH extract. In result antioxidant activity, seed coat > leaf > whole plant. Seed coat were showed a very strong antioxidant activity. The comparative patterns between the antioxidant capacity and HPLC analysis results for the apigenin contained in Cirsium japonicum may also prove to be significant.
        154.
        2016.08 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The seasonal appearance and the chemical composition characteristics of cladode of Opuntia humifusa were investigated in this study. The minor (horizontal) and major (vertical) axes, the width, and weight of O. humifusa cladode were compared for its appearance features. Moisture, crude protein, ash, fat, color, dietary fiber, mineral, and amino acids contents were measured for the comparison of their chemical composition characteristics. The cladode of O. humifusa harvested in summer showed higher values of minor and major axis, width, and weight than those harvested in winter. According to the results of Hunter color index, cladode of O. humifusa harvested in summer showed the highest lightness level (Hunter L value). In the meanwhile, cladode of O. humifusa harvested in spring showed the highest Hunter a (redness) and b (yellowness) values. Cladode of O. humifusa harvested in summer had the lowest crude protein and crude fat contents, while it showed the highest crude ash content. The total contents of moisture and dietary fiber were significantly greater than summer-harvested cladode of O. humifusa followed by spring- and winter-harvested cladode of O. humifusa. The major mineral content of all seasonal cladode of O. humifusa was Ca2+. Glutamic acid and aspartic acid were the major amino acids in all seasonal samples. Contrary, the contents of total amino acids and free amino acids were the lowest in summer-harvested cladode of O. humifusa. Taken together, it was concluded that the appearance and chemical quality of cladode of O. humifusa was versatile depending on the harvesting season.
        155.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 세토카 가지 정유의 주요 성분을 분석하고 이들의 항균, 항염 및 세포독성 실험을 진행하 였다. 세토카는 제주도에서 널리 재배되고 있는 감귤류의 품종이다. 세토카 나무의 가지는 간벌 작업으로 인해 대부분 폐기되고 있고, 이러한 폐자원의 활용은 최근 많은 관심을 받고 있다. 정유 성분은 세토카 가지의 에탄올 추출물을 호호바오일로 처리하여 얻었다. 세토카 정유의 주요 성분은 ethyl linoleate (64.1%), ethyl palmitate (16.5%), neophytadiene (11.1%) 및 β-citronellol (5.1%)임을 확인하였다. 이들의 항균활성을 확인 하기 위하여 피부 관련 미생물에 대한 paper disc 확산법을 실시한 결과 Staphylococcus aureus 및 Propionibacterium acnes에서 좋은 항균활성을 보였다. 또한 항염활성을 확인하기 위해 lipopolysaccharide (LPS)로 염증이 유도된 대식세포에서 nitric oxide (NO) 생성량을 측정한 결과 세토카 정유 성분은 농도의존적 으로 NO 생성을 저해하였다. WST-1 분석법을 이용하여 세포독성을 측정한 결과 RAW 264.7 macrophage 및 HaCaT 각질형성세포에서 세포생존율이 무처리 대조군과 비슷한 결과를 보였다. 이러한 결과를 바탕으로 세 토카 가지 정유는 세포독성이 없으면서 염증억제 및 항균효과가 있음을 확인하였으며, 이를 응용한 화장품소재 로써의 개발이 가능할 것으로 여겨진다.
        156.
        2014.05 KCI 등재 서비스 종료(열람 제한)
        The number concentrations and the water soluble ionic concentrations of PM2.5 have measured at Gosan site in Jeju, Korea, from March 2010 to December 2010, to clarify their characteristics. PM2.5 number concentrations vary from 22.57 to 975.65 particles/㎝3 with an average value of 240.41 particles/㎝3, which have been recorded evidently high in spring season as compared with those in other season. And the concentrations in small size ranges are greatly higher than those in large size ranges, so the number concentration in the size range 0.25∼0.45 ㎛ has more than 94% of the total number concentration of PM2.5. The major ionic components in PM2.5 are SO4 2-, NH4 + and NO3 -, which are mainly originated from anthropogenic sources, on the other hand, the concentrations of Cl-, K+, Ca2+ and Mg2+ are recorded relatively lower levels. The concentrations of the major ionic components are very high in spring season, but the concentration levels of the other components are recorded significantly high in winter season. On the other hand, in summer season, the lowest concentration levels are observed for overall components as well as the sum of them. The concentration ratios of nss-SO4 2-/SO4 2- and nss-Ca2+/Ca2+ are 98.1% and 88.9%. And the concentration ratio of SO4 2-/NO3 -(3.64) is greatly higher than the value in urban area due to no large NOx emission sources in the measurement. In addition, the correlation and the factor analysis for the number and the ionic concentrations of PM2.5 are performed to identify their sources. From the Pearson correlation analysis and the factor analysis, it can be suggested that the smaller parts(<0.5 ㎛) of PM2.5 is contributed by anthropogenic sources, but the sources of the remaining larger parts of PM2.5 are not able to be specified sources in this study.
        158.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        뽕나무를 이용한 고부가가치 건강 기능성 소재를 개발하기 위한 기초 자료 측면에서 ‘과상 2호(Gwasang No. 2)’의 부위별 성분함량 및 생리활성을 조사하였다. 잎에 함유된 비타민 C는 55.3mg· 100g-이었으며, 조 단백질 함량은 잎(25.4%), 뿌리(12.3%), 가지(8.9%) 순으로 많았다. 유리아미노산은 잎에서 29종류, 가지에서 26종류, 뿌리에서 25종류가 검출 되었으며, 함량은 뿌리(26.27mg ·g-), 가지(21.95mg·g-), 잎(16.22mg·g-) 순으로 많았다. 추출물이 1,000mg·L-1 일 때 총 페놀 함량과 총 플라보노이드 함량은 각각 뿌리의 에탄올 추출물에서 51.0mg·L-1 및 42.3mg·L-1로 많았다. 전자공여능은 추출물의 농도가 1,000mg·L-일 때 모두 열수 추출물에서 높았는데, 잎 추출물(69.3%), 뿌리 추출물(68.9%), 가지 추출물(50.2%) 순으로 높았다. 아질산염 소거능은 추출물의 농도가 1,000mg·L-일 때 잎, 가지 및 뿌리 모두 에탄올 추출물에서 61.8%, 54.5 및 42.2%로 각각 높았다. 이와 같은 결과는 뽕나무 ‘과상 2호’의 용도 설정과 효과적인 추출방법을 결정하는데 유익한 정보를 제공할 것으로 생각된다.
        159.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        옥수수 우량 교잡종 육성을 위한 자료로 활용하고자 국내 육성 옥수수 자식계통, F1 종실 및 F2 종실의 이화학적 특성과 지방산 및 아미노산 조성을 각각 분석 검토하였다. 1. F2 종실의 단백질 함량이 9.0%로 자식계통 11.4%와 F1 종실 10.9%에 비하여 유의하게 낮은 것으로 나타났다. 지방 함량은 F2 종실이 자식계통과 F1 종실보다 높았다. 회분은 자식계통, F1 종실, F2 종실간 조성변이에 차이가 없었다. 2. 자식계통, F1 종실, F2 종실 모두 linoleic acid의 조성비가 가장 높고 oleic acid, palmitic acid, stearic acid, linolenic acid의 순으로 지방산 조성비가 높은 것으로 나타났다. F2 종실의 포화지방산의 함량은 17.6%로 F1 종실과는 비슷하였으나, 자식계통보다는 낮았다. F2 종실의 불포화지방산의 함량은 82.4%로 F1 종실과는 비슷하였으나, 자식계통보다는 높았다. 3. F2 종실의 leucine의 함량이 자식계통 및 F1 종실보다 낮았다. 반면 F2 종실의 valine, serine, threonine, cysteine, aspartic acid, lysine, arginine, histidine 등의 함량이 자식계통 및 F1 종실보다 높았다. Alanine 등 나머지 아미노산은 자식계통, F1 종실, F2 종실간 조성변이가 비슷한 경향이었다. 4. 산성아미노산인 MMA(monoamino monocarboxylic acid)가 자식계통, F1 종실, F2 종실에서 그 조성 비율이 가장 높았으며 산성 아미노산인 DMA(diamino monocarboxylic acid), 방향족 아미노산인 AAA(aromatic amino acid) 순으로 조성비가 높았다.
        160.
        2012.06 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 대표적인 섬유작물인 케나프의 가축 사료용으로 이용 가능성을 검증하기 위해서 한국원자력연구원에서 개발한 신품종 장대와 다른 품종들(옥수, C12, C14-DRS)에서 생육특성과 유용물질 함량을 비교 분석하였다. 전체적으로 돌연변이 신품종 장대가 다른 대조품종들보다는 생육이 좋았는데 특히 생체중, 건물중, 줄기직경, 마디 수에서 대조품종들보다 1.6~3.1배 가량 높은 생육 특성을 보였다. 조단백질과 조지방 함량은 장대의 줄기에서 가장 높았으며, 잎에서는 가장 적게 나타났다. 줄기의 조섬유와 조회분 함량은 계통들간의 유의적인 차이를 보이지 않았다. 잎의 조섬유 함량은 C14-DRS가 가장 높았으며 그 다음으로 장대가 높았다. ADF함량은 옥수의 줄기와 잎에서 가장 많이 나타났으며 NDF는 장대의 줄기와 잎에서 가장 높게 나타났다. 총폴리페놀과 총플라보노이드 함량은 옥수, C12, 장대, C14-DRS순으로 나타났다.