• Membrane and Water Treatment
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• 제6권3호
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• pp.237-249
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• 2015

In this study we investigate a laboratory scale vacuum membrane distillation system to produce pure water from model oil in water emulsion. Experimental determination of liquid entry pressure (LEP) of a commercial Durapore$^{TM}$ GVPH flat sheet membrane using model emulsions in various oil concentrations has been carried out. Two different methods of liquid entry pressure determination - a frequently used, so-called static and a novel dynamic method - have been investigated. In case of static method, LEP value was found to be 2.3 bar. No significant effect of oil content on LEP was detected up to 3200 ppm. In contrast, LEP values determined with dynamic method showed strong dependence on the oil concentration of the feed and decreased from 2.0 bar to a spontaneous wetting at 0.2 bar in the range 0-250 ppm, respectively. Vacuum membrane distillation tests were also performed. The separation performance is evaluated in terms of flux behavior, total organic carbon removal and droplet size distribution of the feed and final retentate. No significant effect of oil content on the flux was found ($5.05{\pm}0.31kgm^{-2}h^{-1}$) up to 250 ppm, where a spontaneous wetting occurred. High separation performance was achieved along with the increasing oil concentration between 93.4-97.0%.

• 한국초지조사료학회지
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• 제26권4호
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• pp.257-266
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• 2006

저 농도와 고 농도 돈분 액비의 비료효과를 비교하기 위해 제주대학교 목장에서 2005년 6월부터 9월까지 피의 생산성, 피 재배 토양의 화학적 특성 및 용탈수 특성을 조사하였다. 실험은 난괴법 4처리 (무비구, 200 N kg/ha +150Pkg/ha+150 K kg/ha 화학비료구, 200 N kg/ha 1.8% DM 저농도 돈액비구, 200 N kg/ha DM 7.0% 고농도 돈액비구) 4반복으로 실시하였다. 용탈수는 2005년 8월 21일(1차), 9월 9일(2차) 및 9월 26일(3차)에 각각 채취하였다. 피의 건물수량은 처리 간 통계적 유의차가 없었으나 화학비료구가 가장 높았으며, 초장은 무비구 보다 화학비료와 돈분 액비 시용구에서 통계적으로 유의적 증가를 보였다. 피의 질소, 인 및 칼륨 흡수량은 화학비료와 고농도 돈액비구에서 다른 처리 보다 높은 추세였다. 토양의 OM함량은 무비 보다 비료시용(화학비료와 돈액비시용구)에서 높았으며 Na 함량은 저농도 액비구에서 가장 높았다. 용탈수 중 $NO_{3^-}N$와 $NH_{4^-}N$ 함량은 처리 간 뚜렷한 차이를 발견치 못 하였으며 1차 채수된$SO_4$ 함량은 고농도 액비에서 3차 채수된 $SO_4$ 함량은 저 농도 액비에서 유의적 증가를 보였다(p<0.05). 1차 채수된 용탈수에서 Cl, Mg 및 Na 함량이 고농도 액비에서 2, 3차 채수 시에는 저 농도 액비구에서 높은 함량을 보였다. 결론적으로 하계작물 피에 고농도 액비 시용은 화학비료나 저농도 액비보다 그의 생산성이나 토양 특성에 큰 영향이 없었으며 다만 시용 초기에 용탈 수의 $SO_4$나 Cl, Mg 및 Na 함량에 영향을 주고 있었다.

• Natural Product Sciences
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• 제16권1호
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• pp.39-42
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• 2010

The content of hyperin in Acanthopanax species was determined by high performance liquid chromatography (HPLC). Hyperin was quantified by a reverse-phase column with elution program [initially gradient solvent (acetonitrile : water = 85 : 15 to 80 : 20 for 20 min), then isocratic solvent (acetonitrile : water = 80 : 20 for 20 min), and finally gradient solvent (acetonitrile : water = 80 : 20 to 65 : 35 for 20 min)]. UV detection was conducted at 210 nm. The content of hyperin in the fruits of Acanthopanax was measured in the species A. chiisanensis (2.04 mg/g), A. sessiliflorus (1.13 mg/g), A. divaricatus (0.98 mg/g), A. koreanum (0.75 mg/g) and A. senticosus (0.05 mg/g). The content of hyperin in A. chiisanensis was higher than that of other Acanthopanax species.

• Food Science and Biotechnology
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• 제17권1호
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• pp.102-105
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• 2008

The freezing patterns of commercial frozen foods were characterized by using proton nuclear magnetic resonance ($^1H$ NMR) relaxometry and differential scanning calorimetry (DSC). The liquid-like components like unfrozen water were investigated as a function of temperature (10 to $-40^{\circ}C$) and then compared with the unfrozen water content measured by DSC. The formation of ice crystals and the reduction of water in the foods during freezing were readily observed as a loss of the NMR signal intensity. The proton NMR relaxation measurement showed that the decreasing pattern of the liquid-like components varied depending on the samples even though they exhibited the same onset temperature of ice formation at around $0^{\circ}C$. When compared with the unfrozen water content obtained by the DSC, the NMR and DSC results could be closely correlated at the temperature above $-20^{\circ}C$. However, the distinct divergence in the values between 2 methods was observed with further decreasing temperatures probably due to the solid glass formation which was not detected by DSC.

• 대한화장품학회지
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• 제26권1호
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• pp.93-106
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• 2000

비이온 계면활성제, 다가알코올, 물과 오일을 사용하여 단상형 액정 조성물을 제조하였고 이에 대한 물리적 성질을 조사하였다. 소수성기가 Y 형인 비이온 계면활성제인 POE octyldodecyl ether series와 친수성기가 Y 형인 POE glyceryl monostearate series가 2:1로 혼합한 계면활성제 system에 다과알코올이 혼합됨에 따른 상의 변화를 관찰하여 본 결과 7:3, 6:4, 5:5 인 비율에서 라멜라 백정상의 구조(In)가 잘 발현됨을 보여 주었으며, 상기 비율에 유성성분의 함량에 따른 라멜라 액정상의 발현을 관찰한 결과 계면활성제의 친수성이 높고, 계면활성제와 화가알코올의 비가 7:3인 system 011서 상대적으로 높은 오일을 함유한 라멜라 백정구조 형성이 가능함을 확인하였다. 전상이 되지 않은 상태로 라멜라 백정조성물의 친수성 층011 수분의 함유 정도를 관찰하여 본 결과 제조된 라멜라 액정조성물은 25 - 40% 정도의 수분을 라멜라 층간에 함유할 수 있음을 확인하였고, 백정조성물의 피부 도포 시에 우수한 피부 수분 함유 효과를 보여 주었다.

• Natural Product Sciences
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• 제18권3호
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• pp.171-176
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• 2012

We previously isolated cordycepin, guanosine and tryptophan from Cordyceps militaris as antiadipogenic constituents. For the quality control of C. militaris for anti-adipogenic activity, simultaneous analytical method using high-performance liquid chromatography (HPLC)-diode array detection (DAD) was developed and validated. Quantitation of these compounds in various Cordyceps samples from different sources and various extraction methods were conducted using developed method. Our study shows that natural Cordyceps and host insect possess higher content than cultured ones and fruiting bodies, respectively. The content of cordycepin showed great difference in different C. militaris samples whereas trytophan content was similar in tested samples. Addition of water to extraction solvent greatly increased the yield of guanosine and tryptophan. High temperature and longer extraction time increased yield of guanosine, whereas the content of trytophan was decreased in high temperature during extraction with water. Extraction using ultrasonic apparatus slightly increased extraction efficiency. Cordycepin, however, has little variation in different extraction method tested. Strong anti-adipogenic activity was observed in the samples that contain all the three constituents. Taken together, quantitation of these compounds using developed analytical method might provide basic requirement for the anti-adipogenic activity of C. militaris.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.27-28
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• 2011

This research aims to secure fundamental data for the development offire-retardant wood by soaking dried wood in fire-retardant liquid. To dry wood, optimal drying conditions for softwood usually used as structural material and hardwood usually used as finishing or furniture material were derived by varying the microwave outputs and heating times of microwave wood drying equipment. The research foundthat each specimen needs 8 to 15 minutes of heating time depending on water content and output. For softwood, fire-retardant liquid equivalent to about 10 percent of the total mass of the specimen infiltrated into the dried wood, of which the water content was reduced to 5~6 percent.

• 생약학회지
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• 제46권1호
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• pp.23-30
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• 2015

Processing of medicinal plants is one of the processing methods for reducing of toxicity or improving of effect on medicinal plants. In this study, we studied the changes in the constituents and antioxidant activity in accordance with the processing conditions by the salt water of Citrus unshiu Markovich. Changes in antioxidant activity was measured by the DPPH method and changes in the components were analyzed by high performance liquid chromatography. As a result, the content of the main constituents (narirutin, hesperidin) and total polyphenol were increased by increasing the concentration of salt water. Moreover, antioxidant activity was increased gradually in proportion to the increase of the total polyphenol content.

• 한국구조물진단유지관리공학회 논문집
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• 제24권6호
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• pp.50-58
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• 2020

발수제를 콘크리트 표면에 함침시키는 방법은 콘크리트의 균열이 발생할 경우, 기대하는 내구성을 확보할 수가 없다. 최근, 다양한 방수 및 발수 재료들을 콘크리트나 모르타르 내부에 혼입하여 균열 내부에서도 발수성을 확보하였으나 압축강도가 크게 저하되었다. 압축강도 저하를 극복하기 위해 아직까지 유기물과 무기물의 장점들을 동시에 이용한 연구가 없기 때문에, 본 연구에서는 유기물과 무기물을 적절히 혼합한 유무기 복합 발수제를 모르타르에 혼입하여 물리적 특성 및 발수성능을 평가하였다. 유무기 복합 발수제 혼입 시 Liquid 시험체에 비해 플로우 약 10%, 공기량이 약 50% 감소하였으며, P6L1 시험체의 경우, 기존 발수제인 Powder와 같은 39.5MPa로 무혼입 모르타르 대비 약 3.5%의 압축강도 저하를 확인하였다. 발수성능도 유무기 복합 발수제 혼입 시험체가 기존의 발수제 혼입 시험체인 Powder보다 높은 발수성을 확인하였으며, 염화물 침투 저항성 평가결과, 유무기 복합 발수제 혼입 시험체가 무혼입 모르타르 대비 약 45% 통과 전하량이 감소되는 것을 확인하였다. 이상의 실험을 종합하면, Powder 발수제와 Liquid 발수제를 5:1의 비율로 혼입한 P5L1 유무기 복합 발수제가 압축강도 저하 방지 및 발수성능 확보를 위하여 가장 합리적이라고 판단된다.

• 산업기술연구
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• 제17권
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• pp.119-124
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• 1997

This thesis is an experimental research of shear behavioral characteristics and shear behavioral coefficient of weathered residual soil which is mostly contained in soil of Korea. Using the weathered residual soil from mountain near Kangwon National University, this experimental research were contained the physical properties of sample in term of the basic test method such as specific gravity, plastic and liquid limit, grain-size distribution, density and water content. Experimental results obtained from direct shear test sand triaxial compression tests show that according to step loading, linear strain and linear stress increase continually and angle of internal friction decreases just little according to incresing of water content in case of ignoring the cohesion, and angle of internal friction appears the maximum angle near a optimum moisture content in case of considering the cohesion.