• Korean Chemical Engineering Research
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• 제46권5호
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• pp.994-1001
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• 2008

바이오필터 모델로서 프로세스럼핑 모델(Lim의 모델)을 넓은 농도범위의 친수성 VOC의 경우에도 유효하도록 robust하게 개선하기 위하여, 수막으로 둘러싸였다고 가정한 멸균된 입상 활성탄, compost 및 동부피의 입상 활성탄/compost 담체 각각에 대해서 모델적용에 필요한 Freundlich 등온흡착관계식의 흡착상수들을 구하고 상호 비교하였다. 당 연구에서는 각각 0.04, 0.08, 0.12, 0.16, 0.2, 0.4, 0.8 및 1.0 ml의 에탄올을 멸균된 각각의 젖은 담체에 첨가하여서 바이오필터 운전조건과 같은 $30^{\circ}C$에서 흡착이 정상상태에 도달한 후에 각각의 담체에 대한 흡착량을 산출하는 에탄올 등온흡착평형 실험을 통하여, 각 담체 내부의 세공에 응축된 물에 용해된 에탄올농도와 등온흡착평형을 이루는 에탄올의 평형 흡착량을 모사하는 Freundrich 등온흡착모델의 파라미터인 흡착능 상수(K) 및 흡착지수(1/n) 값을 멸균된 입상 활성탄, compost 및 동부피의 입상 활성탄/compost 담체에 대하여 각각 0.7566과 $5.070{\times}10^{-7}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.7566}$, 0.8827과 $1.000{\times}10^{-8}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.8827}$ 및 0.5688과 $5.243{\times}10^{-6}mg-ethanol/mgmedia/(mg-ethanol/m^3)^{0.5688}$과 같이 구축하였다. 이와 같은 에탄올 등온흡착평형 실험에서 구해진 흡착능 상수 및 흡착지수를 포함하는 Freundlich 흡착상수는, 바이오필터의 바이오막으로 덮여진 바이오필터담체의 흡착특성에 적용할 수 있었다. 당 연구에서의 에탄올의 공기/물 분배계수와 Delhomenie 등의 젖은 compost담체에 대한 톨루엔 흡착실험에서의 톨루엔의 공기/물 분배계수의, 비의 크기 정도는 compost를 담체로 하는 양쪽의 연구에서 산출된 흡착량 비의 크기 정도와 거의 일치하였다.

• Bulletin of the Korean Chemical Society
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• 제24권3호
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• pp.345-349
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• 2003

The quantity, process and kinetics of di-(2-ethylhexyl)phthalate (DEHP) migration in the 30/70 and 40/60 poly(vinylchloride) (PVC)/DEHP blends were investigated using gas chromatograph. A thin and flexible PVC sheet was soaked in surrounding medium (SM) of water/ethanol mixture and acetonitrile with constant stirring to release DEHP. By observed concentration of DEHP in the SM, it is found that acetonitrile is more intense in DEHP migration than water/ethanol mixture. In addition the amount of extracted DEHP is proportional to the leaching temperature and added ratio of DEHP. The behavior of DEHP migration from flexible PVC sheets was described by the Ficks's law with $2.72-10.1\;{times}\;10^{-10}$ cm²/s of the diffusion coefficients.

• 공업화학
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• 제9권4호
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• pp.469-474
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• 1998

스티렌-무수말레인산 공중합체로 가교된 PVA막을 용액법으로 제조하였다. 투과증발공정에서 가교된 PVA/ PSMAn막에 대한 분리거동을 연구하기 위해 30~90 wt % 에탄올-물 혼합 조성에서 막에 대한 팽윤 및 수착 실험을 막내부로 수착되는 용액의 양과 조성을 측정할 수 있는 장치를 이용하여 수행하였다. 본 연구에서 제조된 막의 경우, 수착과 투과단계에서 물에 대해 좋은 선택성을 나타냈고, 공급액의 농도 50 wt % 이상에서 막의 투과선택도는 가교제의 함량에 따른 팽윤비 변화보다 수착선택도와 보다 많은 상관 관계를 나타내었다. 이러한 거동을 투과 선택도와 수착선택도과 관련된 용해-확산 모델로 고찰한 결과, 투과선택도는 막 내에서의 확산단계에서 보다 오히려 수착단계에서 결정됨을 결론지을 수 있다.

• 한국식생활문화학회지
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• 제23권4호
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• pp.479-488
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• 2008

Some biological activities such as an electron donating capacity, the contents of total polyphenol compounds and flavonoids, fibrinolytic activity and $\alpha$-glucosidase inhibitory activity have been detected in hot water extracts of Ligularia fischeri and Angelica gigas Nakai. To increase the usefulness of the functional ingredients for prevention and improvement of some metabolic disorders, ethanol-treated hot water extracts of Angelica gigas Nakai were prepared. A hot water extract of Ligularia fischeri has 92% of electron donating capacity, 39.4 mg/g of total polyphenol compounds, 24.8 mg/g of flavonoids and 29.8% of $\alpha$-glucosidase inhibitory activity, but no fibrinolytic activity. A hot water extract of Angelica gigas Nakai has 94.7% of electron donating capacity, 5.8 mg/g of total polyphenol compounds, 2.6 mg/g of flavonoids, 0.48 plasmin units of fibrinolytic activity and no $\alpha$-glucosidase inhibitory activity. However, with partial purification using cold ethanol treatment, the $\alpha$-glucosidase inhibitory activity of Angelica gigas Nakai was increased to 70.5%. Thus, we expected a more useful effect with the use of the addition of a cold ethanol-treated Angelica gigas Nakai extract. The L, b values of cold buckwheat noodles using a mixture of 0$\sim$3% of Ligularia fischeri powder and 0.5% of an ethanol-treated hot water extract of Angelica gigas Nakai were decreased with the addition of an increasing amount of Ligularia fischeri powder. Among the mechanical qualities, only adhesiveness was significantly higher in 3% Ligularia fischeri noodles. From sensory evaluation data, it was determined that these two functional ingredients did not ruin the color, texture, and overall acceptance of the cold buckwheat noodles. A higher amount of the extracts improved the quality of the product with little added cost.

• Macromolecular Research
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• 제11권3호
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• pp.163-171
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• 2003

For the pervaporation of water-ethanol mixtures, new composite membranes having poly(acrylic acid)-poly (butyl methacrylate-co-methyl methacrylate) interpenetrati ng polymer network [PAA-P(BMA-co-MMA) IPN] skin layer supported on porous and crosslinked poly(BMA-co-MMA) were prepared. The morphology of the sub-layer of the composite membrane prepared in the presence of 60 wt% solvent showed cellular structure, on the other hand that of sublayer prepared in the presence of 70 wt% solvent presented very porous interconnected pore structure with macrovoids. Permeation rates of the composite membranes were largely influenced by the morphology of the sublayer. Separation factors increased with the increase of the degree of crosslinking of the PAA network. It was found that permeation rates could be increased by introducing anionic charges on carboxyl groups of the PAA. The permeation rate changes of the PAA-P(BMA-co-MMA) IPN composite membranes according to the feed compositions showed quite similar pattern with the swelling behavior in water-ethanol mixtures.

• 대한화학회지
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• 제20권5호
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• pp.358-363
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• 1976

물-에탄올 혼합용매속에서 1-염화 및 2-염화나프탈렌술포닐의 두 나프틸 화합물의 가용매 분해반응을 전기 전도도법을 사용하여 속도론적으로 연구하였다. 연구결과 2-나프틸 화합물의 반응속도상수가 1-나프틸 화합물의 것보다 컸다. 이것은 MO이론의 예측과는 반대였으며 전이상태에서 1-나프틸 화합물의 peri-hydrogen 효과에 기인된 것으로 설명할 수 있었다. Winstein 그림표의 m값과 Kivinen 그림표의 n값에 의하면 물-에탄올 혼합용매속에서의 두 염화 나프탈렌술포닐의 가용매 분해 치환반응은 $S_N2$형 반응과정으로 진행된다고 결론지웠다.

• 한국염색가공학회지
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• 제29권4호
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• pp.256-267
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• 2017

The purpose of this study was to analyze the functional ingredients of Perilla Frutescens L. Britt extracts and to confirm the possibility of producing PVA nanofibers using extracts. Distilled water, 3% aqueous sodium hydroxide solution and ethanol were used as extraction solvents. The electrospinning was carried out at a PVA concentration of 12%, an applied voltage of 10 kV and a tip to collector distance of 15cm. The contents of volatile substances, essential oils, total polyphenols and flavonoids of the extracts were measured to examine the constituents of functional materials. Flavor components and esters were identified in 3% sodium hydroxide and ethanol extracts. The content of polyphenols and flavonoids in ethanol extracts was higher than that of medicinal plants. 1wt.% of Tween 20 was added to disperse the essential oil components of the ethanol extract. Addition of a dispersant made it possible to produce a homogeneous mixture by having some compatibility with the ethanol extracts and the PVA molecule. When the concentration of the ethanol extract was 0.25 and 0.5wt%, relatively uniform PVA nanofiber having an average diameter of 350 to 365nm could be produced. The results of FT-IR, XRD and DSC analysis confirmed that Perilla Frutescens L. Britt ethanol extract was well mixed with PVA molecules and was electrospun.

• 한국식품영양과학회지
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• 제33권4호
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• pp.736-740
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• 2004

50% 에탄올 추출박으로부터 기존의 백삼농축액보다 산성다당체가 다량 함유된 백삼 농축액 제조 방법에 대해서 연구하였다. 50% 에탄올을 사용하여 제조한 백삼농축액의 추출 수율과 산성다당체 함량은 에탄올의 농도가 증가할수록 감소하였다. 반면에 백삼을 0∼90% 에탄올로 추출하고 남은 백삼박 내의 산성다당체 함량은 에탄올 농도가 증가할수록 증가하였다. 백삼박으로부터 산성다당체를 얻을 수 있는 최적의 조건은 $\alpha$-amylase를 390∼650 unit/g residue/15 mL 증류수의 농도로 4$0^{\circ}C$에서 5분 동안 처리하는 것으로 확인되었다. 50% 에탄을 추출 후 남은 백삼박에 $\alpha$-amylase를 처리함으로써 백삼박의 물추출액 중의 산성다당체 함량은 무처리구의 8.3%에서 10.5%로 증가하였다. 기존의 50% 에탄올 백삼추출농축액과 본 실험을 통하여 얻어진 백삼박 추출액을 8:2(w/w)로 혼합한 새로운 흔합백삼농축액을 제조한 결과 기존의 인삼농축액에 비해 조사포닌 함량은 비슷하며 약2배 정도의 산성다당체를 함유하고 색도가 짙은 농축액을 제조할 수 있었다.

• 한국태양에너지학회 논문집
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• 제32권spc3호
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• pp.213-219
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• 2012

Nanofluids are advanced concept fluid that solid particles of nanometer size are stably dispersed in fluid likes water, ethylene glycol and others. They have higher thermal conductivities than base fluids. If using this characteristic, efficiencies of heat exchangers can be increased. Therefore in this study, we measured thermal conductivity and viscosity of carbon nanofluids. They were made to ultra sonic dispersed oxidized multi-walled carbon nanotubes(OMWCNTs) in distilled water and ethanol, respectively. The mixture ratios of OMWCNTs were from 0.0005 vol% ~ 0.1 vol%. Thermal conductivity and viscosity was measured by transient hot-wire method and rotational viscometer. The results of an experiment are as in the following: thermal conductivity of the 0.1 vol% pure-water nanofluid improved 7.98% ($10^{\circ}C$), 8.34% ($25^{\circ}C$), and 9.14% ($70^{\circ}C$), and its viscosity increased by 37.08% ($10^{\circ}C$), 33.96% ($25^{\circ}C$) and 21.64% ($70^{\circ}C$) than the base fluids. Thermal conductivity of the 0.1 vol% ethanol nanofluids improved 33.72% ($10^{\circ}C$), 33.14% ($25^{\circ}C$), and 32.25% ($70^{\circ}C$), and its viscosity increased by 35.12% ($10^{\circ}C$), 32.01% ($25^{\circ}C$) and 19.12% ($70^{\circ}C$) than the base fluids.

• Bulletin of the Korean Chemical Society
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• 제5권3호
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• pp.112-117
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• 1984

The association constants (K) of 3,5,N-trimethyl pyridinium iodide in 95 volume percent ethanol-water mixed solvent were determined by a modified UV and conductance method at $25^{\circ},\;30{\circ},\;40{\circ}\;and\;50{\circ}C$ over the pressure range 1 to 2000 bars. The association process is enhanced with increasing pressure and decreasing temperature. From K values, we obtained the total partial molar volume change (${\Delta}V$) and some thermodynamic parameters. The electrostriction volume (${\Delta}V_{el}$) and intrinsic volume (${\Delta}V_{in}$) were also evaluated. The values of ${\Delta}V,\;{\Delta}V_{el},\;{\Delta}V_{in}$ are negative, negative and positive, respectively, and the absolute values of all these three decrease with increasing pressure and temperature. The ion-pair size (a) were varied 3 to 6 ${\AA}$, with pressure and temperature. The solvation number (n) decreased from 2 to 0.5 with increasing temperature.