• 신재생에너지
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• 제10권1호
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• pp.20-29
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• 2014

The present study investigated the effects of thermal pre-treatment on the enhancement of anaerobic biodegradability of waste activated sludge at varied TS concentration levels. The activated sludges were thermally oxidized for 30 minutes at $80{\sim}200^{\circ}C$ with varied TS concentrations (2%, 4% and 6%). and then, sludge characteristics, solubilization efficiency and methane production yield of thermally pre-treated sludges were analyzed. The higher the temperature in the thermal pre-treatment, the higher the concentration levels of dissolved matters such as $SCOD_{Cr}$, $NH_4{^+}$ and VFAs, which indicates that the thermal pre-treatment facilitates the hydrolysis and acid fermentation. Furthermore, the solubilization efficiency was increased in proportion to the temperature rise at all TS concentrations and was reached at 68.9%, 55.6% and 53.1%, respectively, at $200^{\circ}C$. In the BMP test of the pre-treated sludges, higher methane production yields were observed as 0.313. 0.314 and $0.299m^3\;CH_4/kg\;VS_{add}$ at the condition of TS 2% ($160^{\circ}C$), 4% ($160^{\circ}C$) and 6% ($180^{\circ}C$), respectively, and degradation rate was increased by 84%, 79% and 65% compared with non-pretreated waste activated sludge. These findings suggest the effectiveness of thermal pre-treatment of waste activated sludge for anaerobic biodegradable process.

• 공업화학
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• 제20권5호
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• pp.517-521
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• 2009

본 연구는 다양한 갈조류를 이용한 바이오 에탄올 생산을 실험하였다. 갈조류 다당류는 alginate와 laminaran으로 구성되어 있으며, 이를 단당류로 가수분해하면 바이오 에탄올을 생산 할 수 있는 가능성이 높다. 본 연구에서는 열처리와 산 처리 이용하여 갈조류를 당화하고 이를 통한 바이오 에탄올 생산을 확인고자 한다. 에탄올 발효에는 Saccharomyces cerevisiae KCCM1129와 Pachysolen tannophilus KCTC 7937를 이용하였으며, 에탄올 발효효율은 모자반이나 톳보다 다시마에서 월등히 높았다. 다시마를 이용한 최적 전처리 조건에서의 발효 결과 Saccharomyces cerevisiae KCCM1129와 Pachysolen tannophilus KCTC 7937에서 각각 1.83 g/L, 1.96 g/L의 에탄올 생산을 확인 할 수 있었다. 반면, 모자반과 톳에서의 최대 생산량은 0.22 g/L로 매우 낮았다.

• 한국식품과학회지
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• 제25권5호
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• pp.571-575
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• 1993

대두 펩타이드의 표면소수도가 혈청 콜레스테롤의 농도에 미치는 영향을 조사하기 위하여, 대두 단백질(ISP), 카세인(CNP), 이들 단백질을 펩신으로 가수분해하여 pH에 따른 펩타이드 침전 획분들(SHT, SH8, SH6, SH4, CHT, CH6, CH5, CH4)을 흰쥐에 섭취시키고 혈청 콜레스테롤 농도 및 분변 스테로이드이 배설량을 측정하였다. 그리고 각 펩타이드의 표면소수도를 ANS 형광법 및 SDS 결합법으로 측정하여, 이들의 상관관계를 분석한 결과, 펩타이드의 ANS 표면소수도가 높아질수록 분변으로 배설된 스테로이드량은 증가하였으며(r=0.81), 혈청 콜레스테롤 농도는 낮아졌다.(r=-0.868). 그러나 SDS 표면소수도는 그들과 상관관계가 없었다. 또한 대두 단백질은 가수분해에 의하여 ANS 표면소수도가 증가하였다. 이상의 결과는 흰쥐의 담즙염이, 소화중 생성된 높은 표면소수도의 펩타이드와 결합하여 체외로 배출되므로서 대두단백질의 섭취에 의한 혈청 콜레스테롤 농도가 낮아짐을 시사하였다.

• 한국어병학회지
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• 제21권1호
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• pp.1-11
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• 2008

We report the existence of new type of phosphatidylcholine-hydrolyzing phospholipase D (PLD), which has been characterized and partially purified in the scuticociliate, Uronema marinum. The enzyme from partial purification showed that it was existed in membrane fraction and was a neutral PLD, which catalyzed both transphosphatidylation and hydrolysis reaction. The activity of partially purified membrane-bound PLD was also found to be optimal at pH 7.0-7.5 for 2 hours at 37℃ and depended strictly on the presence of Ca2+ (2.5 mM) and Mg2+ (1.6 mM). Immunoblot analysis indicated that the enzyme was distinct from hPLD1 (human PLD1) and hPLD2 (human PLD2) because it was not recognized by a polyclonal antibody raised to the 12 terminal amino acid of these enzymes. We also found that the membrane-bound PLD is a PIP2-dependent PLD and that GTP-binding proteins are not implicated in the regulation of this enzyme: This enzyme activity is markedly stimulated by phosphatidylinositol 4,5-bisphosphate (PIP2) but not by the small G-protein Arf and GTPrS. In addition, this enzyme was capable of hydrolyzing phosphatidylcholine (PC) but not phosphatidylethanolamine (PE), implying that PC was a preferred substrate.

• Applied Biological Chemistry
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• 제18권4호
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• pp.188-193
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• 1975

우리나라의 산간지방(山間地方)에 야생(野生)하는 머루중(中)의 anthocyanin의 구조(構造)를 확인(確認)하였다. 머루에서 0.5% HCl methanol로 추출(抽出)하여 얻은 색소(色素) 추출액(抽出液)을 Amberlite IRC-50 이온 교환수지관(交換樹脂管)을 통과(通過)시켜 정제(精製)하고, Paper chromatography에 의하여 개별색소(個別色素)를 분리(分離)하였다. 각(各) 개별색소(個別色素)에 대하여 부분(部分) 산가수분해(酸加水分解), 결합당(結合糖)의 확인시험(確認試驗), aglycone의 alkali 분해(分解), paper chromatography에서 얻어진 $R_f$치(値), 가시부(可視部)에서의 흡수(吸收) spectra 측정(測定) 등에 의하여 구조(構造)를 확인(確認)하였다. 확인(確認)된 머루중(中)의 7가지 색소(色素)는 delphinidin 3-monoglucoside, petunidin 3-monoglucoside, cyanidin 3-monoglucoside, delphinidin 3,5-diglucoside, malvidin 3-monoglucoside, petunidin 3,5-diglucoside 및 malvidin 3,5-diglucoside 이었으며 cyanidin 3,5-diglucoside로 추측되는 색소(色素) 4-b는 확인(確認)되지 못하였다.

• Applied Biological Chemistry
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• 제42권2호
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• pp.166-169
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• 1999

두충잎으로부터 얻은 MeOH 추출물의 n-BuOH 분획으로부터 silica gel column chromatography를 반복하여 monoamine oxidase B (MAO-B) 억제 활성을 갖는 flavonoid 배당체를 분리하였다. 화합물의 화학구조를 스펙트럼 데이터의 해석과 산가수분해반응을 이용하여 $3-O-[{\beta}-D-glucopyranosyl\;(1{\rightarrow}2)\;{\beta}-D-xylopyranosyl]\;quercetin$으로 결정하였다. 이 화합물의 MAO-B 억제활성에 있어서의 $IC_{50}$ 값은 $8.05\;{\mu}mol/l$로 측정되었다.

• 한국막학회:학술대회논문집
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• 한국막학회 2003년도 추계 총회 및 학술발표회
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• pp.61-63
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• 2003

A major research objective related to proton exchange membrane(PEM) for DMFC is to achieve high proton conductivity over 10$^{-2}$ S/cm, high hydrolytic stability and low methanol permeability with low cost base materials. for the purpose, a lot of thermoplastic polymers such as polysulfones, polyethersulfone, polyetherketones, polyimides, polyoxadiazole, polyphosphazene and polybenzimidazol have been investigated. Amongst those polymers, polyimides have been suggested as a potential PEM due to their excellent thermal, chemical stability and good mechanical properties. Generally, polyimides are synthesized by polycondensation with numerious diamines and dianhydriedes. In our study, polyimide was prepared using non-sulfonated diamine, sulfonated diamine directly synthesized by fuming sulfuric acid, and naphthalenic dianhydride to improve the hydrolysis stability under acidic condition. Through monomer sulfonation-subsequent polymerization method, the high proton conducting capability and the desired sulfonation level were effectively controlled at the same time. To reduce severe methanol transport through the membrane, the chemical crosslinking among polymer chains was introduced using various crosslinking agents with different chain lengths. The crosslinked sulfonated polyimide membranes showed high proton conductivity up to 8.09$\times$10$^{-2}$ S/cm and from crosslinking effect methanol transport through the membranes was considerably reduced as compared with unmodified membranes. For increase of chain length of crosslinker, methanol permeability was adversely reduced to 10$^{-8}$ $\textrm{cm}^2$/s due to decrease of IEC and increase of crosslinking desity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.56-64
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• 2015

Acid mine drainage occurrence is a serious environmental problem by mining industry, it usually contains high levels of metal ions, such as iron, copper, zinc, aluminum, and manganese, as well as metalloids of which arsenic is generally of the greatest concern. An indigenous plant extract was used to produce calcium carbonate from Canavalia ensiformis as effective biomaterial, and its ability to form the calcium carbonate under stable conditions was compared to that of purified urease. X-ray diffraction and scanning electron microscopy were employed to elucidate the mechanism of calcium carbonate formation from the crude plant extracts. The results revealed that urease in the plant extracts catalyzed the hydrolysis of urea in liquid state cultures and decreased heavy metal amounts in the contaminated soil. The heavy metal amounts were decreased in the leachate from the treated mine soil; 31.7% of As, 65.8% of Mn, 50.6% of Zn, 51.6% of Pb, 45.1% of Cr, and 49.7% of Cu, respectively. The procedure described herein is a simple and beneficial method of calcium carbonate biomineralization without cultivation of microorganisms or further purification of crude extracts. This study suggests that crude plant extracts of Canavalia ensiformis have the potential to be used in place of purified forms of the enzyme during remediation of heavy metal contaminated soil.

• Applied Biological Chemistry
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• 제41권2호
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• pp.197-200
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• 1998

홍화 MeOH 추출물의 n-BuOH 분획으로부터 silica gel column chromatography를 반복하여 2종의 flavonoid 배당체를 분리, 정제하였다. 화합문의 화학구조를 HMBC를 포함한 NMR, MS, IR과 같은 기기분석 결과와 산가수분해반응을 이용하여 결정, 각각 $3-O-[{\beta}-D-glucopyranosyl(1{\rightarrow}2)\;{\beta}-D-glucopyranosyl]\;kaempferol$ 및 $3-O-[{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)\;{\beta}-D-glucopyranosyl]\;kaempferol$로 동정하였다. 각 화합물은 Grb2-Shc 결합저해활성$(IC_{50}:43,\;47\;{\mu}g/ml)$을 나타내었다.

• Applied Biological Chemistry
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• 제40권6호
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• pp.583-587
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• 1997

고구마 괴근을 MeOH 수용액으로 추출하고, 얻어진 추출물을 EtOAc, n-BuOH 및 물로 용매분획하였다. EtOAc 분획에 대하여 column chromatography를 반복하여 4종의 화합물을 분리하였다. 각 화합물의 화학구조를 NMR, MS 등 스펙트럼 데이터의 해석 및 가수분해, 메칠화 및 아세칠화반응을 적용하여, 수지 배당체, simonin I, ${\beta}-sitosterol$ 및 2종의 불포화지방산 화합물로 구명하였다.