• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.41-47
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• 1998

The solvent flushing apparatus for soil remediation was manufactured. After the soil around nuclear facilities was sampled and was compulsorily contaminated by Co, the remediation characteristics by solvent flushing were analyzed. Meanwhile, one-dimensional solute transport within nonequilibrium sorption code was developed for modelling of the soil remediation, input parameters for modelling were measured by laboratory experiment. Experimental results are as follows : When water was used as a solvent, the higher was the hydraulic conductivity, the higher the efficiency of soil remediation was. When EDTA solution was used as a solvent, the soil remediation efficiency of EDTA solution showed higher than that of water.

• 전기화학회지
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• 제1권1호
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• pp.52-54
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• 1998

Polypyrrole (PPy), Poly(N-methyl Pyrrole) (PMPy) and Poly(N-phenyl Pyrrole) (PPhPy) films in acetonitrile (Af and propylene carbonate (PC) have been compared focusing on their different ion and solvent transport behaviors. During the redox reaction of PPy films, cation, anion, and solvent take part in mass transport. Whereas during the redox reaction of PMPy and PPhPy films, anion and solvent transport are dominant but cation transport is negligible. In addition, solvent transport occurs in the same direction with cation transport for PPy films. On the other hand, solvent transport occurs in the opposite direction to anion transport for PMPy films, and it changes its amount and direction with the kind of the dopant anion and the solvent used at electropolymerization for PPhPy films.

• Bulletin of the Korean Chemical Society
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• 제25권12호
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• pp.1893-1897
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• 2004

Hydrodynamic simulations of mesoscopic solvent have been performed by multi-particle collision algorithm in a real dimensional system without and with the random shifting of the grid. A systematic conversion of the dimensionless units to a real dimensional system was confirmed by jump rates of solvent particles. Speed distributions of solvent particles obtained from the simulations agreed very well with the Maxwell-Boltzmann distributions. Solvent viscosities obtained from the simulations and from the conversion of units are exactly the same which confirmed the correct conversion of the units once again. The calculation of the friction coefficient of a massive Brownian particle in a mesoscopic solvent as a function of Brownian particle diameter was examined as an example.

• 한국식품영양학회지
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• 제12권4호
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• pp.358-363
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• 1999

This study was conducted to evaluate the extraction methods for the determination of antioxidants in soybean oil. Recovery rates of various antioxidants in soybean oil showed similar rates as 80.4~102.1% by solvent/solvent extraction method and 89.9~106.4% by sweep co-distillation method except 46.6~61.2% of PG at corresponding spiked concentractions. The maximun recovery rates of antioxidnts were obtained when extraction time and extraction temperature used in UNITREX were 20min and 21$0^{\circ}C$ respectively. In the recovery rates with the activation of florisil when 2% ofwater was added to florisil the highest recovery rates for TBHQ, BHA, BHT were obtained by sweep co-distillation met-hod. Therefore sweep co-distillation method showed less solvent simple operation and high recovery rate compared with solvent/solvent extraction method.

• Bulletin of the Korean Chemical Society
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• 제15권3호
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• pp.214-221
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• 1994

We present some results obtained from theoretical study on a non-symmetrical A/BC polymeric system including solvent which consists of two phases, a polymeric phase A on one side and a mixture of polymers B (as a compatibilizer) and C on the other in the presence of a solvent. By employing the functional integral techniques we derive the mean-field equations and solve them numerically to deduce the physical properties of the interface involving the polymers and solvent concentration profiles in the limit that molecular weights of all the polymers involved tend to infinity. The calculations are performed for typical values of the Flory interaction parameters and for the volume fraction of polymer B in the asymptotic phase and of solvent. In the polymers/solvent blend under consideration the interfacial adsorption of polymer B, the solvent concentration, and degrees of the specific interaction between the polymers are found to play important roles in modification of the interfacial properties.

• 한국응용과학기술학회지
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• 제38권1호
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• pp.292-299
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• 2021

본 연구에서는 해삼속의 폴리페놀과 플라보노이드의 생리활성물질을 추출하기 위한 용매분획의 수율을 확인하고자 연구를 시도하였다. 이미 보고된 사례에서 50%에탄올 추출 용매분획은 해삼 항산화 물질의 높은 수율 결과로 확인되었다. 해삼의 항산화물질 추출량을 결정짓는 것은 추출에 적용된 추출 용매분획의 결과로 확인되었다. 또한 '추출용매에 따라 해삼생리활성 항산화물질 추출함량이 크게 차이가 있다.'는 선행연구를 통해 용매분획추출에 관한 필요성의 결과를 얻었다. 50%에탄올 추출 용매분획의 해삼추출물에 포함된 페놀물질의 높은 항산화성분 추출 결과가 증명되었다. 추출용매분획 연구사례에서 수율이 가장 저조한 아세트산에틸 용매분획은 다른 용매분획에 비해 높은 페놀함량을 수확하여 항산화효과가 확인되었다. 이에, 추출 용매분획물의 적용에 따른 수율변화를 통해 항산화추출물의 높은 수율에 미치는 영향을 확인 하였다. 따라서 본 연구를 통해 50%에탄올 용매의 최적화된 해삼생리활성물질 추출 용매분획으로 검증되었다.

• 폴리머
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• 제25권6호
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• pp.811-817
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• 2001

용매와 비용매의 다양한 비율에 따라서 bisphenol A polycarbonate(PC)의 무정형에서 결정성의 상변화를 확인하였다. 용매로 chloroform을, 비용매로 isopropanol을 사용하였다. 결정화된 PC는 광학현미경과 SEM, XRD, DSC를 이용하여 조사하였고, DSC와 XRD의 측정값은 PC의 결정화도를 판단하는데 이용하였다. 용해도 상수는 PC의 결정화도를 조절하는데 중요한 인자로 PC 결정화도 차이는 혼합용매의 용해도 상수 차이로 설명하였다. 용매와 비용매 비율이 75/25 wt%의 PC 용액에서 고결정화도를 가진 PC powder로 얻을 수 있었다. 이런 결과는 혼합용매의 용해도 상수(9.85)가 PC의 용해도 상수(9.9)와 유사하였기 때문이라고 판단된다.

• 폴리머
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• 제32권5호
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• pp.483-488
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• 2008

광학용 폴리카보네이트 필름 제조에 사용되는 methylene chloride/1,3-dioxolane 혼합 용매가 폴리카보네이트 결정화에 미치는 영향에 대하여 살펴보았다. Methylene chloride에 환경 친화성 용매인 1,3-dioxolane을 혼합한 co-solvent를 용액 캐스팅 PC 필름 가공의 용매로 사용하는 경우, 혼합된 1,3-dioxolane에 의하여 필름 건조 시 용매 제거 속도가 느려져 PC필름의 결정화를 유발시킴을 알 수 있었다. 이러한 결정화 현상은 용매 조성비 및 용매 건조 온도를 조절하여 용매 제거 속도를 증가시킴으로 최소화할 수 있음을 확인하였다. PC의 결정화는 PC 필름의 표면 거칠기를 증가시키고 이는 필름의 광학 특성을 감소시키는 요인으로 작용함을 알 수 있었다.

• Applied Biological Chemistry
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• 제47권2호
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• pp.228-237
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• 2004

농약성분 분석에 있어서 시료 전처리시간을 단축할 수 있는 분석방법을 개발하기 위해 농산물 중에 잔류하고 있는 잔류농약성분을 대상으로 ASE(accelerated solvent extraction) 방법을 활용한 자동화된 전처리 방법을 검토하였다. ASE 추출조건은 preheat 1 min, heat 5 min, static 1 min, solvent flush% 60 vol, nitrogen purge 60 sec, cycle 4, pressure 1500 psi, temperature $100^{\circ}C$를 선택하였다. 이 분석조건과 n-hexane:acetone(4 : 1, v/v)를 추출용매로 사용하였을 때, ASE 추출과 정제능력은 solvent extraction 방법과 유의적인 차이를 보이지 않았고, 추출 용매의 감소는 추출산물의 재현성에 큰 영향을 미치지 않았다. ASE 방법은 잔류농약 분석 시 소요되는 유기용매의 양을 감소하고 추출과 정제를 동시에 수행함으로써 동결건조 시간을 제외한 전처리 시간이 단축되어 분석비용 또한 solvent extraction에 비해 감소시킬 수 있었다.

• 한국식품저장유통학회지
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• 제8권2호
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• pp.157-163
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• 2001

Optimal conditions for hot water extraction of Liriope spicata tuber were investigated with changes in solvent ratio(2∼6 fold) and heating time(1∼5 hr) by response surface methodology. The content of extractable solids increased with an increased in solvent ratio, and the highest content showed at heating time of 3 hr. The content of total steroid saponin increased with a decrease in solvent ratio, and increased with an increase in heating time at increasing the solvent ratio. The content of non-reducing sugar containing oligosaccharides at a lower solvent ratio didn’t show changes depending on heating time, while that at a higher ration decreased with an increase in heating time. Optimal extraction conditions using hot water as the limited conditions of 15∼18% extractable solids, 1.5∼2.0% total steroid saponin, 6∼8% reducing sugar, 6∼7% non-reducing sugar and 13∼15 brix were 3 hrs of heating time and 4 fold of solvent ratio.