복합막 제조를 위한 가교된 폴리비닐알코올 막의 특성 평가와 이를 이용한 투과증발 분리

김연국,이정민,임지원,이영무 한국막학회 1999 멤브레인 Vol.9 No.3

본 실험실에서 개발된 sulfur-succinic acid의 가교제를 이용한 가교된 폴리비닐알코올 (poly(vinyl alcohol), PVA) 균일막은 15℃에서 반응이 일어나므로 복합막을 제조할 때 지지체의 가공구조을 파괴할 우려가 있어 반응온도를 10℃이하로 낮추고자 하였다. 이 때 촉매로서 염산이 사용되었고, 결과 막은 가교반응의 유무를 관찰하기 위하여 화학적.열적 분석을 행하였다. 이로부터 반응온도 10℃, 반응시간 90분, 촉매(염산) 농도 1.5%일 때 최적의 막을 제조할 수 있는 조건을 알 수 있었다. 또한 폴리설폰 한외여과 막 위에 coating하여 복합막을 제조하였으며 , 이의 분리특성을 조사하기 위하여 메틸터셔리부틸에테르/메탄올 혼합액에 대하여 조업온도 30, 40, 5℃에서 투과증발실험을 수행하였다. 실혐 결과 공급액의 온도 5℃에서 5.09g/m2hr의 투과도와 3℃에서 1622의 선택도를 얻었다. In the crosslining reaction of poly(vinyl alcohoJ)(PVA) with sulfur-succinic acid which had been established in our previous work, reaction temperature, 15℃, was so high to collapse the pore structures in support membrane for the preparation of composite membrane. Therefore, the efforts have been focused on lowering of the reaction temperature to 100℃ by using a catalysis, HC!. The newly established crosslinking reaction was characterized through the analysis of the chemical and thermal properties. From these results, the optimum conditions for the membrane preparation couId be drawn as followings : (i) reaction temperature, 100 ℃,(ii) reaction time, 90 min, (iii) the concentration of the catalysis (HCD, 1.5%. Composite membranes were fabricated by coating a casting solution containing PYA, sulfur-succinic acid and HCl on a support membrane followed by crosslinking it at 10℃. The resulting membranes were applied to the pervaporation separation of methyl-tert-butyl ether(MTBE)/methanol (MeOH) mixtures at 30, 40, and 50℃. The flux of 5.09 g/m2hr at 50℃ and the highest separation factor of 1622 were obtained, respectively.

Control of micropores in carbon molecular sieve membranes derived from thermally labile polymeric additive containing polymer blends

김연국,박호범,이영무 한국공업화학회 2003 한국공업화학회 연구논문 초록집 Vol.2003 No.-

어리쌀바구미에 대한 식물정유의 훈증독성과 기피효과

김연국,김광호,이종진,이회선,이상계,Kim, Yeon-Kook,Kim, Kwang-Ho,Lee, Jong-Jin,Lee, Hoi-Seon,Lee, Sang-Guei 한국응용곤충학회 2012 한국응용곤충학회지 Vol.51 No.4

Stored grain insects appear frequently as grains are harvested, stored, and distributed on the market. Producers mostly depend on chemical fumigants to control and repel insect pests, but this application of chemicals may cause side effects for humans and the environment. Safer control approaches, including the use of natural products are required, and in this study, we assessed the control effect of essential oils on stored grain insects. The essential oils of 8 plant species from 6 families were tested for their fumigant toxicity and repellent effects using a Y-tube Olfactometer against Sitophilus zeamais adults. Pennyroyal and tea tree oil respectively exhibited 97% and 63% mortality at $10{\mu}{\ell}L^{-1}$ air concentration in tested fumigant toxicity. Of particular note, pennyroyal oil ($LT_{50}$, hour=3.87) showed higher adulticidal activities than tea tree oil ($LT_{50}$, hour=4.09). When assessing repellent effects, using a Y-tube Olfactometer at $10{\mu}{\ell}$/filter paper concentration, the cedarwood, cinnamon, cypress, patchouli and pennyroyal essential oils showed potent repellent activities against Sitophilus zeamais adults. Cinnamon, cypress and pennyroyal essential oils showed notably high repellent activities of 82.4%, 80.0% and 86.7%, respectively, at $1{\mu}{\ell}$/filter paper concentration. 본 연구는 쌀을 비롯한 저장곡물을 가해하는 어리쌀바구미(Sitophilus zeamais) 성충에 대해서 8종의 식물정유의 훈증독성과 Y-tube를 이용한 후각반응으로 기피효과를 조사하였다. $10{\mu}{\ell}/L$ air의 농도에서 훈증독성시험 결과 pennyroyal과 tea tree 오일에서 각각 97%, 63%의 높은 살충효과를 보였다. 특히, pennyroyal oil($LT_{50}$, hour=3.87)은 tea tree oil($LT_{50}$, hour=4.09)보다 높고 빠른 살충력을 보였다. $10{\mu}{\ell}$/filter paper의 농도에서 후각계를 이용한 기피효과는 Cedarwood(80%), Cinnamon(83.3%), Cypress(81.1%), pennyroyal(97.1%) oil이 높은 기피활성을 보였으며, 이보다 낮은 $1{\mu}{\ell}$/filter paper의 농도에서도 Cinnamon(82.4%), Cypress(80.0%), pennyroyal(86.7%) 오일은 높은 기피활성을 나타냈다.

Study on the Performance of polyamide composite membranes prepared by Interfacial Polymerization

김연국,제갈종건,이규호 한국고분자학회 2001 한국고분자학회 학술대회 연구논문 초록집 Vol.2001 No.4

벼멸구에 대한 식물추출물의 살충활성과 기피효과

김연국,이종진,최만영,Kim, Yeon-Kook,Lee, Jong-Jin,Choi, Man-Young 한국응용곤충학회 2008 한국응용곤충학회지 Vol.47 No.1

Methanol extracts of 35 plant species in 20 families were tested for their insecticidal activities and repellent effects against Nilaparvata lugens female adult by topical application and spray methods. The insecticidal activities and repellent effects of variousplant species and parts were different. The methanol extracts from stem of Garcinia xanthochymus, Senecio scandens and Phytolacca americana, seedcoat of Ginkgo biloba, and leaf+stem of Ailanthus altissima and Catalpa ovata showed potent insecticidal activities against N. lugens. Specially, the G. biloba extract exhibited higher than 90% mortality against N. lugens at a concentration of 4,000 ppm. Repellent effects of plant extracts obtained from whole plant of Daucus carota, fruit of Semecarpus anacardium, leaf+stem of C. ovata and Wisteria sinensis were active, and potent. Also, the plant extracts that are potent in insecticidal activity not necessarily have high repellent activity showing no significant corelation between the two activities. 식물추출물(20과 35종)을 사용하여 미량국소처리방법과 분무방법으로 벼멸구 암컷성충에 대한 살충활성과 기피효과에 대해 실험을 수행하였다. 살충활성과 기피효과의 결과는 식물종과 그 부위에 따라 다양한 차이를 보였다. 인면과수, 구리광, 미국자리공의 줄기 추출물, 그리고 취춘과 석류나무의 잎+줄기 추출물이 벼멸구에 대하여 높은 살충활성을 보였다. 식물추출물들의 기피효과는 남학슬의 전부위 추출물, 캐슈나무의 열매추출물, 석류나무와 등나무의 잎+줄기 추출물이 높은 기피활성을 보였다. 이 실험에 사용한 식물추출물들에서 기피효과가 높은 식물추출물들의 살충활성이 불규칙적으로 나타나 기피효과와 살충률의 관계가 성립되지 않았다. 따라서 처리된 식물추출물의 벼멸구에 대한 살충활성과 기피 효과는 상관관계가 없음을 알 수 있다.

Synthesis and characterization of metal-containing sulfonated polyimide membranes and their gas separation properties

김연국,박호범,이영무 한국고분자학회 2002 한국고분자학회 학술대회 연구논문 초록집 Vol.2002 No.4

Stratified Sampling Design Based on Data Mining

김연국,오윤환,박성훈,조성준,박하영 대한의료정보학회 2013 Healthcare Informatics Research Vol.19 No.3

Objectives: To explore classification rules based on data mining methodologies which are to be used in defining strata in stratified sampling of healthcare providers with improved sampling efficiency. Methods: We performed k-means clustering to group providers with similar characteristics, then, constructed decision trees on cluster labels to generate stratification rules. We assessed the variance explained by the stratification proposed in this study and by conventional stratification to evaluate the performance of the sampling design. We constructed a study database from health insurance claims data and providers’ profile data made available to this study by the Health Insurance Review and Assessment Service of South Korea, and population data from Statistics Korea. From our database, we used the data for single specialty clinics or hospitals in two specialties, general surgery and ophthalmology, for the year 2011 in this study. Results: Data mining resulted in five strata in general surgery with two stratification variables, the number of inpatients per specialist and population density of provider location, and five strata in ophthalmology with two stratification variables, the number of inpatients per specialist and number of beds. The percentages of variance in annual changes in the productivity of specialists explained by the stratification in general surgery and ophthalmology were 22% and 8%, respectively, whereas conventional stratification by the type of provider location and number of beds explained 2% and 0.2% of variance, respectively. Conclusions: This study demonstrated that data mining methods can be used in designing efficient stratified sampling with variables readily available to the insurer and government; it offers an alternative to the existing stratification method that is widely used in healthcare provider surveys in South Korea.

가교된 PVA 막을 이용한 MTBE/methanol 혼합물의 증기투과(Vapor Permeation)분리

김연국,임지원 한국막학회 2000 멤브레인 Vol.10 No.3

본 연구에서는 sulfur-succinic acid의 가교제를 이용한 가교된 폴리비닐알코올(poly(vinyl alcohol), PVA) 가교막을 이용하여 MTBE-methanol 혼합액에 대하여 조업온도, 가교제의 조성에 따른 증기투과 공정의 투과 특성을 조사 하였다. 팽윤 실험을 통해 PVA/SSA 가교막에 대하여 가교제 조성에 따른 막의 구조와 PVA의 하이드록실기(-OH), SSA의 설폰기(-SO3H)와 용매와의 수소결합의 두 가지 인자가 상호 보완적으로 작용하고 있음을 알 수 있었다. 투과 특성에 있어 SSA의 설폰기가 중요한 인자로 작용하였다. 예를 들면 7% SSA 막에 대해서는 수소결합의 효과보다는 가교도의 효과가 투과 특성에 중요한 요인으로 작용하며 5% SSA에 대해서는 수소결합의 효과가 중요하게 작용하였다. 증기투과 공정에 있어 막과 직접 접촉하는 증기상이 액상에 비하여 methanol의 농도가 낮아 PVA의 하이드록실기와 methanol과의 수소결합 확률이 감소함에 따라 투과 특성에 영향을 미친다. 결과적으로 7% SSA 막에 대하여 MTBE/mthanol=80/20 혼합액에 대하여 공급액의 온도 30℃에서 선택도 2187, 투과도 4.84g/m2hr를 보여 주었다. Poly(vinyl alcohol)(PVA)/sulfur-siccinic acid(SSA) membrane performances have been studied for the vapor permeation separation of methyl tort-butyl ether(MTBE)/methanol mixtures with varying operation temperatures, amount of cross-linking agents, and feed compositions. 1'here are two factors, the membrane network and the hydrogen bonding, in the swelling measurements of PVA/SSA membranes. These two factors act interdependently on the membrane swelling. The sulfuric acid group in SSA took an important role in the membrane performance. The cross-linking effect might be more dominant than the hydrogen bonding effect due to the sulfuric acid group at 7% SSA membrane. Hydrogen bonding effect was more important for 5% SSA membrane. In vapor permeation, density or concentration of methanol in vapor feed is lower than that of methanol in liquid feed, as a result, the hydrogen bonding portion between the solvent and the hydroxyl group in PVA is reduced in vapor permeation. In this case, the 7% SSA membrane shows the highest separation factor of 2187 with the flux of 4.84g/m2hr for MTBE/methanol=80/20 mixtures at 30℃.

Pyrolysis of Metal Cations-containing Sulfonated Polyimides and Their Gas Permeation Properties

김연국,박호범,이영무 한국고분자학회 2002 한국고분자학회 학술대회 연구논문 초록집 Vol.2002 No.10

Gas permeation properties of carbon molecular sieve membranes based or metal-containing sulfonated polyimide

김연국,박호범,이영무 한국공업화학회 2002 한국공업화학회 연구논문 초록집 Vol.2002 No.0

Carbon molecular sieve membranes with attractive separation properties were formed by pyrolysis of a polymeric precursors. We study the synthesis and characterization of a thermally stable metal-containing in sulfonated polyimides (M-SPI) based on benzophenone tetracarboxylic dianhydride (BTDA), 4, 4-diamino 2, 2-biphenyl disulfonic acid (BDSA) and meta-phenylenediamine (mPDA). X-ray photoelectron spectroscopy (XPS) was chosen as a tool for confirmation of metal substitution in sulfonic acid group. Thermogravimetric analysis (TGA) spectrum of the M-SPI showed approximately 5% weight loss in the range of 250-350°C and the final decomposition began at around 500.C. Wide angle X-ray diffraction (WAXD) spectra of M-SPI show no crystalline behavior, indicating an amorphous structure of the polymer. The gas transport properties of d and N2 for M-SPI have been investigated as a function of the substituted metal ion in sulfonic acid group. The O₂ permeability slightly increased in the order of Li-SPI〈Na-SPI <K-SPI. It might be explained that the d-spacing between polymer interchains increased by the presence of metal ions with different ion radii. Metal-containing sulfonic acid groups on the phenylene also inhibited the close packing of the polymer chains.