" The Korean Journal of Chemical Engineering " 게재 논문 요약 : Processabilities & Mechanical Properties of the Biodegradable LDPE / Modified Starch Blends

Young Jin Kim,Yong Man Lee,Hyang Mok Lee,O Ok Park 한국화학공학회 1994 NICE Vol.12 No.5

N/A An investigation of the biodegradable polymers based on starch has been accomplished. Starch needs to be modified before blending with low density polyethylene(LDPE) because of its hydrophilicity. Three kinds of modification methods were applied to obtain the compatibility to starch-LDPE blends. The first one was the esterification of the hydroxyl group of starch with acetic anhydride. The second was the copolymerization of actylonitrile and styrene onto starch. The last was the esterification reaction of the hydroxyl group of starch with three kinds of ionomers. The tensile strength, % elongation, Young`s modulus, and shear viscosities of blends of the modified starch and LDPE were examined. Ionomer-treated starch showed better compatibility with LDPE to give better performances than other blends.

PROCESSABILITIES & MECHANICAL PROPERTIES OF THE BIODEGRADABLE LDPE/MODIFIED STARCH BLENDS

Kim, Young Jin,Lee, Yong Man,Lee, Hyang Mok,Park, O Ok 한국화학공학회 1994 Korean Journal of Chemical Engineering Vol.11 No.3

An investigation of the biodegradable polymers based on starch has been accomplished. Starch needs to be modified before blending with low density polyethylene (LDPE) because of its hydrophilicity. Three kinds of modification methods were applied to obtain the compatibility to starch-LDPE blends. The first one was the esterification of the hydroxyl group of starch with acetic anhydride. The second was the copolymerization of acrylonitrile and styrene onto starch. The last was the esterification reaction of the hydroxyl group of starch with three kinds of ionomers. The tensile strength, % elongation, Young's modulus, and shear viscosities of blends of the modified starch and LDPE were examined. Ionomer-treated starch showed better compatibility with LDPE to give better performances than other blends.

후두와 병변 수술의 발생한 경막하 긴장성 기두증

목진호,김한식,이규춘,박용석,이영배 東國大學校醫學硏究所 1999 東國醫學 Vol.6 No.-

긴장성 기두증은 신경외과영역에서 개두수술 후에 발생할 수 있는 드문 합병증으로 특히 만성 뇌경막하 혈종 제거수술이나 좌위에서 후두와 수술을 시행한 경우에 발생할 수 있다. 따라서 개두수술 후에 신경학적 증상의 악화가 있거나 수술 후 예상경과를 취하지 않는 경우에는 긴장성 기두증의 발생 가증성을 항상 고려하여야 한다. 긴장성 기두증의 발생기전은 물병을 거꾸로 세운 것과 같은 기전(Inverted pop-bottle mechanism)으로 뇌척수액이 누수된 만큼 공기방울이 경막하강으로 올라가 빈 공간을 메우는 것이다. 이와 같은 기전으로 두개강내로 들어간 공기가 일정한 압력을 가지게 되어 주변 뇌조직을 압박하여 신경학적 장애를 초래하게 된다. 뇌전산화 단층촬영을 이용하여 쉽게 진단이 가능하며 치료는 두개골 천공을 시행하여 두개강내 공기를 배기시켜 줌으로서 가능하다. 저자들은 복와위에서 후두와 병변 수술 후에 발생한 긴장성 기두증을 뇌전산화 단층촬영을 이용하여 진단하고 전두골을 천공하여 두개강내 공기를 배기시켜 치험하였기에 문헌고찰과 함께 증례를 보고하는 바이다. 중심단어:긴장성 기두증, 후두와 수술, 경막하강, 복와위 Tension pneumocephalus is a rare complication in neurosurgical operation and should be considered whenever a patient fails to recover as expected following surgery. The possible mechanism for the entry of air into the subdural space is analogous to the entry of air into an inverted soda-pop bottle. As the fluid pours out. air bubbles reach the top of the container, Computed tomography permitted rapid diagnosis including localization of the air, thus facilitating prompt treatment. Peaking of frontal lobe. mountain appearance of frontal lobe. and air densities at the cisterns are characteristic findings of' tension pneumocephalus on brain CT scan. This condition is easily diagnosed and treated using twist-drill aspiration. The authors describe a case of subdural tension pneumocephalus complicating the early postoperative course after posterior fossa surgery in the prone position.

이산화질소, 암모니아 및 수분의 기상반응에 의한 암모늄염 생성 거동에 관한 연구

목영선,이호원,현영진 제주대학교 해양과환경연구소 2001 해양과환경연구소 연구논문집 Vol.25 No.-

This study investigates the kinetics of the gas phase reaction between nitrogen dioxide, ammonia and water vapor, and presents the appropriate ranges of the process variables such as initial NO_2 concentration, absolute humidity and reaction temperature for the effective removal of nitrogen dioxide. According to the kinetic calculations, the gas phase reaction for the removal of NO_2 takes effectively place at the water vapor content higher than 4-6 %(v/v), but further increase in the water vapor content does not significantly enhance the removal. The residence time required to achieve a desired removal efficiency of NO_2 was found to increase with the decrease in its initial concentration. Especially, the residence time required rapidly increases when the initial concentration of NO_2 is less than 100 ppm. The removal rate of NO_2 is in inverse proportion to the reaction temperature, i.e., lower temperature is favorable to promote the removal rate. The results obtained in this study may be useful for the determination of the optimal values of the process variables in non-thermal plasma technology for the removal of nitrogen oxides.

유전체 플라즈마 방전을 이용한 톨루엔 분해 공정에서 충진물,인가 전압,가스 조성 및 전압 극성이 분해효율 및 전력 전달에 미치는 영향

목영선,이호원,현영진,함성원,조무현,남인식 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.1

교류 고전압을 이용하는 유전체 플라즈마 반응기에서 휘발성유기화합물의 일종인 톨루엔의 분해에 대한 연구가 수행되었다. 유전체 충진물로는 직경 4-6㎜인 유리구슬과 4.75-6.7㎜인 천연 제올라이트가 사용되었다. 톨루엔의 분해 및 전력공급에 미치는 유전체의 물리적 특성, 산소함량, 피크전압, 전압 극성의 영향에 대해 고찰하였다. 유리구슬과 천연 제올라이트가 유전체 반응기에 충진되었을 때, 톨루엔의 분해 성능 및 방전 전력이 증가되었다. 천연 제올라이트는 높은 비표면적에도 불구하고, 톨루엔 분해성능 및 전력공급에 있어서 유리구슬과 유사한 특성을 보여 주었는데, 이러한 결과는 정상상태에서 유전체의 흡착성이 톨루엔의 분해에 영향을 주지 못하며, 톨루엔의 분해는 플라즈마 방전에 의해서만 활성화된다는 것을 의미한다. 유전체 충진물이 없을 때는 유전체 충진물이 있을 때 보다 매우 높은 전압에서 톨루엔의 분해가 일어나기 시작하였다. 산소 함량이 증가될수록 톨루엔의 분해 효율이 조금씩 증가하였는데, 이 결과는 산소에서 비롯된 활성 성분인 O 라디칼, O^+ 및 O_2^+이온 등이 질소에서 비롯된 활성 성분(N, N^+, N_2^+)보다 톨루엔의 분해에 있어서 더 중요한 역할을 한다는 것을 나타낸다. 교류 고전압을 반파 정류하여 양 또는 음의 고전압만을 반응기에 인가하였을 때는 방전전력 및 톨루엔 분해효율이 교류의 경우보다 크게 감소하였다. 양의 고전압과 음의 고전압은 톨루엔 분해 및 전력공급에 있어서 동일한 특성을 나타내었다. 고온 소각 및 유전체 플라즈마 공정에서 얻어진 톨루엔 분해반응 속도를 서로 비교한 결과, 고온 소각이 더 높은 분해반응속도를 가지는 것으로 나타났으나, 고온 소각을 위해서는 상당량의 열에너지가 필요하므로 유전체 플라즈마 공정이 충분히 경쟁 가능한 기술임을 알 수 있었다. Dielectric barrier plasma reactor using AC power was applied to the decomposition of toluene. Natural zeolite of 4.75-6.7㎜ and glass beads of 4 to 6㎜ in diameter were used as the dielectric packing materials. The effects of the dielectric packing materials, the oxygen content, the peak voltage, the voltage polarity on the decomposition of toluene and the power delivery were examined. When the dielectric materials such as glass beads and natural zeolite were packed in the reactor, the performance for the decomposition of toluene and the discharge power increased. Despite the adsorption capability, the zeolite showed similar decomposition performance to the glass beads, which indicates that the adsorption capability does not affect the decomposition of toluene in steady state condition. In the absence of the dielectric packing material, higher voltage was required to decompose toluene. As the oxygen content was increased, the decomposition efficiency slightly increased. When the AC voltage was rectified to positive or negative half-wave, the discharge power and the decomposition efficiency greatly decreased. The decomposition efficiency of toluene was identical, regardless of the voltage polarity changed by half-wave rectification. Although the thermal incineration has larger decomposition rate constant than the dielectric barrier plasma processit requires a lot of thermal energy to heat the gas to a high temperature, and thus the dielectric barrier plasma process is considered to be sufficiently competitive to the thermal incineration.

동시에 진단된 대장암·위암 중복암 2예

신영도,이상목,이기형,윤충 대한대장항문학회 1996 Annals of Coloproctolgy Vol.12 No.3

저온 플라즈마를 이용한 휘발성 유기화합물의 분해에 관한 연구

목영선,이호원,현영진 제주대학교 환경연구소 2000 환경연구논문집 : 제주대 Vol.8 No.-

A non-thermal plasma process using pulsed corona discharge was applied to the destruction of a volatile organic compound (propene). Propene was found to be easily destroyed by this process, and the destruction efficiency was proportional to the supplied power while it was in inverse proportion to the initial propene concentration. Ethane and formaldehyde were detected at the reactor outlet, but the concentrations of such byproducts were negligible. The destruction rate equation (first order in terms of propene concentration) and the rate constant (6.75×10^(3)s^(1)W^(1)) proposed were validated by the comparison between the calculations and experimental data. The increases in the contents of oxygen and water vapor decreased the pulse energy delivered to the plasma reactor. At the initial concentration of 5.85 X 10^(3) mol/㎥, the average energy requirement to destroy one molecule of propene was in the range of 26 to 47 eV according to the amount of propene destroyed, which is relatively low value, compared with that of nitric oxide(NO).

전기투석에 의한 아세트산의 농축 : 이온이동의 모델링 Ion Transport Modeling

이병철,김영목,이상운 弘益大學校 産業技術硏究所 2005 産業技術 Vol.15 No.-

This paper deals with the concentration of acetic acid using monopolar electrodialysis its modeling. Voltage changes, energy consumption were measured at various acetic acid concentrations, pHs, and current densities. Based on the experimental results, mathematical models were developed. Model predictions of acetic acid concentration and pHs were in good agreement with the experimental data.

Cyanobacterium Synechocystis PCC6803 내에서 Bacillus thuringiensis subsp. morrisoni PG-14 cryIVD 유전자의 발현

이대원,박현우,진병래,정영호,박영목,강석권 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.2

미생물 살충제로 사용되고 있는 B. thuringiensis를 모기유충방제에 적용하기 위한 시도는 B. thuringiensis가 수서생태계에서 부유하지 못하고 가라앉으며, 생활환을 이루지 못한다는 문제점으로 인해 적용에 어려움이 있다. 따라서 본 연구는 모기유충에 강한 독성을 갖는 B. thuringiensis subsp. morrisoni PG-14의 cryIVD 유전자를 모기유충의 먹이인 cyanobactrium에 도입하기 위하여 발현벡터 pCYASK 5-1을 제작하고, cyanobacterium Synechocystis PCC6803에 형질전환시켜, 세포내에서 cryIVD 유전자의 발현과 뇌염모기에 대한 독성을 조사하였다. 그 결과 형질전환체 내에서 cryIVD 발현은 immunoblot 분석을 통해 B. thuringiensis subsp. morrisoni PG-14에서 발현된 단백질과 같은 분자량으로 발현되는 것을 확인하였으며, 모기유충에 대한 형질전환체의 독성은 1.40×10^6 cells/ml 농도에서 약 80%의 치사율을 나타내었다. Bacillus thuringiensis subsp. morrisoni PG-14 is a gram-positive soil bacterium producing mosquitocidal parasporal inclusions composed of several crystal proteins. Among these crystal protein genes, cryIVD gene is one of major component which has 72 kDa in size. However, these parasporal inclusions sink quickly from the surface of water where mosquito larval feeding occurred. To develope mosquitocidal cyanobacterium, therefore, we constructed the expression vector, pCYASK 5-1 harboring cryIVD gene. The expression vector, pCYASk5-1 was transformed into the cyanobacterium Synechocystis PCC6803 reported as a natural mosquito larval food source and the transformants were selected with kanamycin. Expression of cryIVD gene in transformant was characterized by SDS-polyacrylamide gel electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined electrophoresis (PAGE) and immunoblot analysis. The mosquitocidal activity of a transformant was determined with Culex tritaeniorhynchus. The results showed that the transformed cyanobacterium is toxic to mosquito larvae and will be expected as a potential agent that is used for mosquito control.

설편평세포암에서 CD44, MMP-2, MMP-9, TIMP-1의 발현

이상화,표성운,김영실,최목균 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Adhesion molecules and proteinases play an important role in the invasion and metastasis of a malignant tumor. However, there have not been many studies on tongue squamous cell carcinoma at Saint Mary's Hospital and Kangnam Saint Mary's Hospital, the Catholic University of Korea, between 1994 and 2000, and had not received chemo-or radiotherapy. The expression of the adhesion molecules CD44H, proteinases MMP-2 and MMP-9, and TIMP-1, which controls MMP activity, was analyzed by immunohistochemistry. In addition their association with the tumor size, lymph node metastasis, clinical stage, and cell differentiation was evaluated. Increased MMP-2 expression was significantly correlated with lymph node metastasis and clinical stage. However, it did not correlate with tumor size or cell differentiation. CD44H, MMP-9 and TIMP-1 expression were not significantly related to tumor size, lymph node metastasis, clincial stage and cell differentiation. The results suggest that MMP-2 is a possible immunohistochemical prognostic factor in tongue squamous cell carcinoma. Futher reasearches will be needed to investigate the additional tumor prognostic factors and their mechanisms.