• 한국수산과학회지
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• 제28권5호
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• pp.659-666
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• 1995

톳과 모자반으로 부터 fucoidan을 추출, 정제하여 그 성질을 분석, 검토하였다. Fucoidan의 추출 조건은 pH 2.0의 산성 추출액으로 $65^{\circ}C$에서 1시간씩 3회 추출을 하고 cethylpyridinum chloride를 사용하여 부분 정제하였다. 부분 정제 fucoidan의 수율은 톳 $2.51\%$, 모자반 $1.56\%$였다. DEAE-Sephadex A-25 이온 교환 칼럼으로 부분 정제 fucoidan을 분획한 결과 톳, 모자반 모두 3종의 획분으로 분획되었고, 각 획분은 전기 영동상에서 2종 이상의 band가 검출되어 불균일함을 알 수 있었다. 분획한 주획분을 다시 알콜 분별 침전법으로 재분획한 결과 톳은 에타놀농도 $60-70\%$에서 침전된 획분 (P-70)이, 모자반은 에타놀농도 $60-65\%$에서 침전된 획분 (P-65)이 cellulose acetate 전기 영동 및 젤 여과 크로마토그라프상에서 각각 균일성을 나타내었다. 균일하게 정제 된 톳과 모자반 fucoidan의 fucose : galactose : 황산기의 mole 조성비는 각각 1:0.66:2.74와 1:0.24:1.46였으며, 분자량은 톳은 26,000, 모자반은 105,000이었다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.121-121
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• 2004

The groundwater in the Pocheon area occurs from both a fractured bedrock aquifer in igneous and metamorphic rocks and an alluvial aquifer with a thickness of <50 m, and forms a major source of domestic and agricultural water supply. In this study, we performed a hydrogeochemical study in order to identify the control of geochemical processes on groundwater quality. For this study, groundwater level and physicochemical parameters (EC, Eh, pH, alkalinity) were monitored once a month from a total of 150 groundwater wells between June 2003 to August 2004. A total of 153 water samples (13 surface water, 66 alluvial groundwater, 74 bedrock groundwater) were also collected and analyzed in February 2004. Groundwater chemistry in the study area is very complex, depending on a number of major factors such as geology, degree of chemical weathering, and quality of recharge water. Hydrochemical reactions such as the leaching of surficial and near-solace soil salts, dissolution of calcite, cation exchange, and weathering of silicate minerals are proposed to explain the chemistry of natural groundwater. Alluvial groundwaters locally have very high TDS concentrations, which are characterized by their chloride(nitrate)-sulfate-bicabonate facies and low Na/Cl ratio. Their grondwater levels are highly fluctuated according to rainfall event. We suggest that high nitrate content and salinity in such alluvial groundwaters originates from the local recharge of sewage effluents and/or fertilizers. Likewise, high concentrations of nitrate were also locally observed in some bedrock groundwaters, suggesting their effect of anthropogenic contamination. This is possibly due to the bypass flow taking place through macropores. Tile degree of the weathering of silicate minerals seems to be a major control of the distribution of major cations (sodium, calcium, magnesium, potassium) in bedrock groundwaters, which show a general increase with increasing depth of wells. Thermodynamic interpretation of groundwater chemistry shows that the groundwater in the study area is in chemical equilibrium with kaolinite and Na-montmorillonite, which indicates that weathering of plagioclase to those minerals is a major control of hydrochemistry of bedrock groundwater. The interpretation of the molar ratios among major ions, as well as the mass balance calculation, also indicates the role of both dissolution/precipitation of calcite and Ca-Na cationic exchange as bedrock groundwaters evolves progressively.

• 한국식품영양과학회지
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• 제39권8호
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• pp.1156-1164
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• 2010

미강유(RBO)와 달맞이꽃 종자유(EPO)를 기질로 한 다양한 몰비율(1:3, 1:4, 1:5)을 가지고 효소촉매를 이용한 재구성 지질을 합성하였다. 달맞이꽃 종자유의 주요 지방산은 필수 지방산인 linoleic acid(C18:2)와 $\gamma$-linolenic acid(C18:3n-6)가 각각 74.9%와 8.1%를 차지하였다. 비율별로 합성된 재구성 지질의 주요 지방산을 살펴보면 oleic acid, linoleic acid, $\gamma$-linolenic acid가 전체 지방산 조성의 88% 이상을 차지하였다. 합성한 재구성 지질은 $\gamma$-linolenic acid를 각각 7.2%(1:3)와 7.9%(1:4), 8.3%(1:5)로 함유하였다. 반응에 사용된 기질 및 합성된 재구성 지질의 TAG 조성을 reversed-phase HPLC를 이용하여 분석한 결과, 미강유의 비율이 증가할수록 달맞이꽃 종자유의 주요한 peak인 LLL(trilinolein) peak는 감소하였고, 새로운 peak의 형성은 점차 증가하였다. 재구성 지질 및 반응에 사용된 미강유와 달맞이꽃 종자유의 $\alpha$-, $\gamma$-, $\delta$-tocopherol 함량을 분석한 결과, 미강유는 $\alpha$-tocopherol과 $\gamma$-tocopherol이 각각 7.60, 2.11(mg/100 g) 함량을 나타내었으며, $\delta$-tocopherol은 검출되지 않았다. 달맞이꽃 종자유는 $\alpha$-tocopherol 및 $\gamma$-tocopherol은 각각 13.36과 10.82(mg/100 g)를 나타내었다. Phytosterol 함량은 달맞이꽃 종자유가 744.49 mg/100 g으로 가장 높은 수치를 보였고, 미강유는 606.64 mg/100 g이었다. 한편, scale-up한 재구성 지질의 phytosterol 함량을 분석해 본 결과, 반응하기 전 campesterol, stigmasterol 및 $\beta$-sitosterol 함량이 3시간 반응 후 감소하였다. 이로써 필수지방산인 $\gamma$-linolenic acid를 함유한 재구성지질을 효소를 이용하여 성공적으로 합성하였다.

• 한국수산과학회지
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• 제49권3호
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• pp.301-309
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• 2016

To facilitate the effective use of butter clam shell as a natural calcium resource, we determined the optimal conditions for calcium lactate (BCCL) preparation with high solubility using response surface methodology (RSM). The polynomial models developed by RSM for pH, solubility and yield were highly effective in describing the relationships between factors (P<0.05). Increased molar ratios of calcined powder (BCCP) from butter clam shell led to reduced solubility, yield, color values and overall quality. The critical values of multiple response optimization to independent variables were 1.75 M and 0.94 M for lactic acid and BCCP, respectively. The actual values (pH 7.23, 97.42% for solubility and 423.22% for yield) under optimization conditions were similar to the predicted values. White indices of BCCLs were in the range of 86.70–90.86. Therefore, organic acid treatment improved color value. The buffering capacity of BCCLs was strong, at pH 2.82 to 3.80, upon the addition of less than 2 mL of 1 N HCl. The calcium content and solubility of BCCLs were 6.2–16.7 g/100 g and 93.6-98.5%, respectively. Fourier transform analysis of infrared spectroscopy data identified BCCL as calcium lactate pentahydrate, and the analysis of microstructure by field emission scanning electron microscopy revealed an irregular form.

• 공업화학
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• 제10권6호
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• pp.876-880
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• 1999

이온성과 비이온성계면활성제의 혼합 미셀 용액의 자기확산계수는 NMR FT-PGSE법으로 측정하였다. 또한 프로톤 NMR 피크의 폭을 관찰하였다. 연구된 계는 $C_{12}EO_5/SDS/D_2O$, $C_{12}EO_5/DTAC/D_2O$ 및 $C_{12}EO_8/SDS/D_2O$의 혼합계이다. 모든 시료에서 솔벤트와 계면활성제의 몰비는 일정하고 계면활성제의 혼합비는 다양하게 실험을 하였다. $C_{12}EO_5$ 계에서 계면활성제의 자기확산계수는 이온성계면활성제의 혼합비가 약 25%일 때 최소치를 나타내었다. 비이온성계면활성제가 이온성계면활성제로 치환됨에 따라서 자기확산계수가 감소하는 것은 미셀간의 반발력이 증가하기 때문이다. 이온성계면활성제의 높은 분율에서 자기확산계수가 증가하는 것은 미셀의 크기가 감소하기 때문이다. $C_{12}EO_8$ 계에서 계면활성제의 혼합비의 효과는 분자의 기하학적 구조와 큰 관능기의 면적 때문에 거의 없다. 프로톤 NMR 피크와 자기확산계수는 상호 밀접한 관계를 나타내고 알킬 사슬의 메틸렌 시그날의 넓혀짐 현상은 자기확산계수가 작을 때 나타난다.

• 한국재료학회지
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• 제4권3호
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• pp.319-328
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• 1994

솔-제법에 의한 고분자솔 제조를 위하여 금속 알콕사이드에 $\beta$-diketonate(DKT)기의 유기 리간드를 치환시켜 만든 전구체를 합성한 결과, 가수분해와 축합 반응의 속도 조절이 가능하였고, 이를 이용하여 코팅에 적합한 nm단위의 입자 크기를 갖는 알루미나, 티타니아 솔을 제조하고 그 물성을 파악하였다. 코팅에 적합한 알루미나 솔의 최적조건은 알콕사이드 1몰당 물 1몰, 산 0.3-0.4몰이었다. 티타니아 솔의 제조시는 물/알콕사이드의 몰비가 1이고, 산의 양은 치환수에 따라 달라 1개와 2개 치환된 전구체의 경우 1목의 알콕사이드당 각각 0.25, 0.20몰 이하였다. Dynamic light scattering 장치를 이용하여 제조한 솔의 평균 입자 크기를 측정한 결과 수 nm단위의 미세한 입자를 갖고 있었다. 슬라이드 글라스 위에 코팅하여 $450^{\circ}C$에서 소결한 막을 SEM으로 관찰한 결과 알루미나와 타타니아의 경우 각각 4-4.5$\mu \textrm{m}$, 2-2.5$\mu \textrm{m}$두께의 매끄럽고 균열이 없는 막이 형성되었음을 알 수 있었다. 이때의 입자 크기는 TEM사진을 통하여 알 수 있었으며 티타니아의 경우 수 nm에서 최대 30nm, 알루미나는 1-2nm이하 심지어 수 $\AA$정도의 입자들로 이루어졌음을 관찰하였다. 또한 회절무늬 분석 결과 알루미나는 $\gamma$구조, 티타니아는 anastase결정임을 알 수 있었다.

• Journal of Pharmaceutical Investigation
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• 제24권2호
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• pp.95-104
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• 1994

Inclusion complexes of ketoconazole(KT) with ${\alpha}^_$, ${\beta}^_$cyclodextrin(CD) and $dimethy1-{\beta}-cyclodextrin$ (CD) and $dimethy1-{\beta}-cyclodextrin(DM{\beta}CD)$ as nasal absorption enhancer were prepared in 1: 2 molar ratios by freeze-drying and solvent evaporation methods. In order to compare with the intrinsic absorptivity of KT in the jejunum(J) and the nasal cavity(N), the in situ simultaneous perfusion method was employed. The in situ recirculation study revealed that KT-CD inclusion complexes with the greater stability constant and the faster dissolution rate proportionally increased the absorption of KT in the J and N of rats. The rank order of apparent KT permeability$(P_{app}\;:\;cm/sec\;{\time}\;1O^{-5}{\pm}S.E.)$, corrected by surface area of absorption, was $5.10{\pm}0.3(N,\; KT-DM{\beta}CD)$ )> $4.13{\pm}0.4(N,\;KT-{\beta}-CD)$ )> $3.52{\pm}0.2(N,\;KT-{\alpha}-CD)$ )> $2.76{\pm}0.3(J,\; KT-DM{\beta}CD)$ )> $2.61{\pm}0.5(J,\;KT-{\beta}-CD)$ )> $2.42{\pm}0.4(J,\;KT-{\alpha}-CD)$ at pH 4.0. The in crease in permeability of $KT-DM{\beta}CD$ inclusion complex was 2.6 folds in the J and 4.5 folds in the N when the perfusing solution was changed from the buffer(pH 4.0) to saline. The absorption rate of $KT-DM{\beta}CD$ inclusion complex after nasal administration was more rapid than those of ketoconazole alone and $KT-DM{\beta}CD$ inclusion complex after oral administration to rats. In comparision with an oral administration of ketoconazole suspension in corn oil, the relative bioavailability was calculated 137.3% for the oral and 195.0% for nasal $KT-DM{\beta}CD$ inclusion complex in rats. The present results suggest that $KT-DM{\beta}CD$ inclusion complex may serve as a potential nasal absorption enhancer for the nasal delivery of ketoconazole.

• 공업화학
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• 제19권5호
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• pp.497-503
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• 2008

디젤 및 바이오디젤의 구성 성분 중에 포함된 n-파라핀과 포화 지방산 메틸에스테르가 저온에서 결정화되는 것을 방지하기 위하여 여러 가지 기술들이 알려져 있다. 그 중에서 메타크릴레이트 공중합체가 디젤의 유동점과 저온필터막힘점을 낮출 수 있는 효과적인 저온유동성 향상제로 알려져 있다. 본 논문에서는 C12, C18 및 C22 지방 알콜과 메타크릴산의 에스테르화 반응에 의하여 알킬 메타크릴레이트 단량체를 합성하여 스티렌과 30:70, 50:50 및 70:30의 몰 비율로 라디칼 공중합체를 합성하였다. 합성한 공중합체의 구조를 $^1H-NMR$ 및 FT-IR 스펙트럼으로 분석하였으며 GPC로 분자량을 측정하였다. 디젤 및 바이오디젤을 5% 함유한 경유(BD5)에 100~5000 ppm의 공중합체를 첨가하여 유동점 및 CFPP 등의 저온 유동성을 평가하였다. 저온 유동성을 평가한 결과, 스티렌-스테아릴 메타크릴레이트 공중합체(PStmSMAn)의 저온 유동성이 다른 공중합체에 비하여 우수하였으며 특히, PSt82SMA18 공중합체 5000 ppm을 함유한 BD5의 유동점이 첨가 전에 비해 $25^{\circ}C$, CFPP $9^{\circ}C$ 강하되는 결과를 나타내었다.

• Ocean and Polar Research
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• 제27권4호
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• pp.359-379
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• 2005

In order to understand the spatial and temporal variations of nutrients and factors controlling their distribution in Gwangyang Bay, this study was carried out bimonthly from June 2001 to July 2003, Inorganic silicate and nitrate concentrations ranged from $0.04{\mu}M\;to\;69.5{\mu}M(avg.\;12.9{\mu}M)$, and from $0.12{\mu}M\;to\;42.2{\mu}M\;(avg.\;7.83{\mu}M)$, respectively. Silicate concentrations measured just after the typhoon were the highest with an average of $43.2{\mu}M$ at the surface layer in June 2001, whereas the highest nitrate concentration $(avg.\;37.0{\mu}M)$ was observed in the surface layer in July 2003. River runoff apparently influenced variations in silicate and nitrate concentrations (r=0.701 and 0.728, p<0.000, respectively) as well as salinity (r=-0.628, p<0.000). Phosphate concentrations ranged from $0.24{\mu}M\;to\;5.70{\mu}M\;(avg.\;1.34{\mu}M)$ and were highest at stations 5, 6, and 7, near a fertilizer plant with an average of $2.01{\mu}M$. On the basis of N/P and Si/N molar ratios, limiting nutrients have varied temporary and spatially. During 2001-2002, nitrogen was a limiting nutrient in the study area, and Phosphate was limited when a large volume of freshwater flowed into the bay. Silicate was limited when the high standing crops of phytoplankton occurred in the whole study area throughout 2003, and in the inner bay in February and August 2002. During the study period, factors controlling the distribution of nutrients might be summarized as follows; 1) inflow of freshwater by heavy rain accompanied by typhoons and frequent rainfall in summer, showing high concentrations of silicate and nitrate, 2) release of high phosphate concentrations from the fertilizer plant located in the south of Moydo to adjacent stations, 3) release of nutrients from bottom sediment, 4) magnitude of occurrence of phytoplankton standing crops.

• 한국대기환경학회지
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• 제21권1호
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• pp.119-129
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• 2005

The ambient TSP data measured at Seoul, Incheon. Taean, Daegu, Busan in Korea were used to explain the chemical composition and general features of Asian Dust (AD) observed in Korea. 9 episodes out of 19 were sampled from 2000 through May 2002, and measurements were conducted covering ionic and metal components with mass concentration. The results showed that daily averaged mass concentration (TSP) during the AD episodes was 458 $\mu\textrm{g}$/㎥, and ionic and metal concentrations were 27.93 $\mu\textrm{g}$/㎥ and 71.7 $\mu\textrm{g}$/㎥, respectively, accounting for 6.1 % and 15.5% of the total aerosol mass. TSP concentrations during episodes were varied from 120 to 1742 $\mu\textrm{g}$/㎥ according to the impact of Asian Dusts and had a tendency of showing higher values at sites in the west side of Korea, which can be explained by the effect of diffusion and deposition. In this study, ionic components like Ca (NO$_3$)$_2$, CaSO$_4$, NaNO$_3$, Na$_2$SO$_4$ were prominent types in secondary aerosol during AD periods and also indicated that V, Co as well as soil elements such as Ca, Fe, Mg, Mn, K correlated well with Al, while Cu, Cd, Pb, Zn didn't agree well with it. In addition, enrichment factors (EFs) for each metal component were obtained to provide simple information about source contribution of Asian Dust, and the results were compared with those from other AD studies. In this study, the results showed that aerosol properties in Korea during the Asian Dust were considerably different from those of general atmospheric condition and specially varied from case to case rather than site to site, which implies that there are certain variations in the soil of source region, pathways of air mass, and meteorological condition. For the enhanced study, those factors should be combined with the features of Asian Dust resolved from this study.