PFA / Silica 유-무기 복합체의 제조 및 표면특성

범정철,하종욱,박인준,이수복 한국공업화학회 2003 응용화학 Vol.7 No.1

Poly(perfluoroalkyl acrylate)(PFA) / silica composites having different silica size were prepared by surface polymerization. In this study, surface characterizations of PFA/silica composites were done by HR-TEM(High Resolution Transmission Microscopy), contact angle measurement, sliding angle measurement, surface roughness measurement, and the relationships between the sliding angle and the contact angle were investigated. In the highly hydrophobic region, the sliding angles of water droplets decreased with increasing contact angle. Their surface free energies were calculated with contact angle data by geometric mean approximation. The composites with super water repellent and sliding could be obtained with contact angle of above 150。and sliding angle of below 10。to water droplets. The ultimate value of surface free energies of the composites reached below ca. ldyn/cm.

표면중합을 이용한 초발수 복합입자의 제조 및 표면특성 : 중합시간의 영향 The Effect of Polymerization Time

범정철,하종욱,박인준,김정훈,이수복,ShiYuan, Cheng 한국공업화학회 2003 응용화학 Vol.7 No.2

This study investigates the preparation of poly(perfluoroalkyl acrylate)[PTA]/silica composite particles by surface polymerization and their characteristics according to surface polymerization time. The particles were prepared by "grafting-from" technique by immobilizing self-assembled initiator and surface radical polymerization from silica particle surface. Characterization was done by contact angle and sliding angle measurements, surface roughness measurement and surface free energy estimation Contact angle were inversely proportion to sliding angle. Graft density(GD) and contact angle of composites increased according to polymerization time. On the other hand, surface free energy and sliding angle were decreased according to increment of polymerization time.

Poly(perfluoroalkyl acrylate)/Silica 나노복합체의 표면이행성 연구

범정철,하종욱,이광원,박인준,소원욱,이수복 한국공업화학회 2003 응용화학 Vol.7 No.2

Surface migration of Poly(perfluoroalkylethyl acrylate)(PFA)/silica nanocomposites added in poly(methylmethacrylate()(PMMA) was investigated by comparing before and after annealing. In this study, surface migration characterizations of PFA/silica composites were measured by SEM(Scanning Electron Microscopy) and contact angle measurement. Their surface free energies were calculated with contact angle data by geometric mean approximation. The contact angles were increased and the surface free energies were decreased, according to increasing the graft density of nanocomposites and decreasing the concentration of PMMA, respectively. It was confirmed that PFA/silica nanocomposites were successfully migrated toward the surface of the PMMA film.

재조합 대장균에 의한 Poly(3-hydroxybutyric acid)의 생산

김범수 建陽大學校 1994 建陽論叢 Vol.- No.3

A recombinant Escherichia coil strain XLI-Blue (KS) harboring the poly(3-hydroxybutyric acid) [P(3HB)] biosynthesis genes from Alcaligenes eutrophus was used to produce P(3HB) by pH-stat fed-batch culture in complex medium. Intial glucose concentration for optimal growth was found to be 20 g/L from a series of flask culture. A final P(3HB) concentration of 89 g/L could be obtained after 42 h of cultivation. The pH-stat fed-batch culture of recombinant E. coli K12 (pSYL 104) using defined medium was not suitable for efficient production of p(3HB) due to the formation of acetic acid. Exponential feeding fed-batch culture of E. coli K12 (pSYL 104) achieved high cell concentration (101 g/L) by controlling the specific growth rate as low as 0.1 h?. However, the P(3HB) content was very low because of the different conditions for cell growth and P(3HB) production.

‘제3세대’이후 국내 러시아 연구의 현황과 과제 : 사회과학을 중심으로

박수헌,신범식 서울대학교 러시아연구소 2006 러시아연구 Vol.16 No.2

Since the mid-1990s, Russian Studies in Korea have been in the stage of "relative stabilization" after undergoing the ups and downs in the previous years. The rise of the "third generation" scholars, many of which returned to Korea after earning their doctoral degrees in Russia, has contributed to this trend. The current research, based on a comprehensive review of social science works on Russia, published as M. A. and Ph.D theses, in book forms and monographs, and as articles in 12 academic journals during the past decade in Korea, shows the following developmental tendencies in the Russian Studies in Korea since the mid-1990s. First, the number of Korean specialists on Russia has consistently increased. Second, the scope of research has been extended in spatial dimension as well as in research topics. In the former, while CIS countries other than Russia have increasingly became the subject of research, the investigation of local politics and economy in Russia has also grown. In the latter, topics have been more diversified beyond the traditional fields of politics, economy, society, and history into education, law, media, anthropology, and political geography. Third, the cases of field researches and surveys have continued to increase, which can contribute to a qualitative progress in the Russian Studies in Korea. Fourth, more research efforts have been devoted to the analysis of various aspects of Russia from a comparative theoretical perspective. Fifth, new attention has been called to the methodological issues in understanding the Russian experiences. Despite these new developments and achievements, however, Russian Studies in Korea still offer the room for continuing improvement. First, compared with those countries with more advanced Russian Studies, the Russian Studies community in Korea is still much small, and there are very few specialists on other CIS countries than Russia. Second, Russian politics and economy still command a disproportionally high position in terms of research topic. Third, researches are lopsidedly tilting toward policy-oriented studies rather than contributing to strengthening the foundation of Russian Studies. Fourth, the previous tendency to approach the Russian experiences from the viewpoint of break with the past has not been fully overcome. Fifth, although efforts have been made for establishing a "Korean style of studying Russia", the Western approaches to the Russian realities still enjoy a disproportionately high popularity. Sixth, strenuous endeavor among the Russian Studies community is required for implementing interdisciplinary researches of Russia as subject of area studies.

광주·전남지역의 무역구조 분석

모수원,김창범 조선대학교 지역사회발전연구원 2001 地域發展硏究 Vol.6 No.1

환경친화적인 무기/유기 Core-Shell의 제조에 관한 연구

설수덕,임재길,임종민,권재범,이내우 한국안전학회 2004 한국안전학회지 Vol.19 No.1

Composite particles using inorganic and organic chemicals were synthesized and the results of those reaction were compared to variation of temperature and agitation speed in presence of CaCO₃ which was adsorbed SDBS. Also the synthesises were optimized according to conversion rate of composite particles. In inorganic/organic core-shell composite particle polymerization, CaCO₃ adsorbed by 0.5wt% surfactant SDBS was prepared initially and then core CaCO₃ was encapsulated by sequential emulsion polymerization using MMA at the addition of APS 3.16X 10^(-3)mo1/L to minimize the coagulated PMMA particle itself during MMA shell polymerization. Encapsulated PMMA on CaCO₃ as inorganic/organic core-shell particles was verified by Fr-IR and DSC analysis. It was found that the CaCO₃ was very well encapsulated by PMMA as shell. The surfaces were distinctly found as spindle shape and broad particle distribution after capsulation.

Yersinia pseudotuberculosis 감염증 환아 1례

한윤수,박범수,한헌석,김염 충북대학교 의과대학 충북대학교 의학연구소 1997 忠北醫大學術誌 Vol.7 No.1

Yersinia는 장내세균과에 속하는 그람음성간균으로 그 중 사람에게 병원성을 갖는 것은 Y. pestis, Y. enterocolitica, Y. pseudotuberculosis의 세 균종으로 알려져 있으며, 주로 동물의 병원체이지만 감염된 동물과 직접 또는 간접적으로 접촉한 사람에서도 질병을 일으키는 것으로 보고되고있다. 이중 Y. pseudotuberculosis는 소화기 증상 발현뿐 아니라 피부병변등의 다양한 임상증상을 유발하기 때문에 다른 질환과의 감별이 어렵다고 알려져있다. 그 동안 Y. pseudotuberculosis 감염증은 국내에서 다수 보고되었으나, 청주를 중심으로한 인근지역에서의 발생은 보고된 예가 없었다 이에 저자들은 지속적인 고열과 전신피부발진을 주소로 내원하여 복통, 설사 등의 소화기증상과 더불어 피부의 낙설, 경부임파선염, 입술의 홍조 등 가와사끼병과 유사한 임상양상을 보이며 청주근방의 약수터에서 길어온 약수를 섭취한 기왕력이 있는 5세 여아가 혈청학적으로 Y. pseudotuberculosis로 진단된 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Yersinia pseudotuberculosis infection is an intestinal infectious disease and its clinical symptoms vary. In this report, we describe the clinical symptoms and laboratory findings of a 6 year old female child who had a history of ingestion of mountain water and was diagnosed on the basis of a 4-fold or greater titer change in agglutinating antibody. She admitted to CNU hospital with major complaints of fever, skin rash, and gastrointestinal symptoms. Litter in the course, periungal desquamation developed, mimicking Kawasaki disease. Treatments with antibiotics improved the conditions and serum examination revealed the Yersinia pseudotuberculosis 4a, 4b infection.

모터내장형 주축계의 열특성 해석

서창범,김수태,유근종 國立 昌原大學校 産業技術硏究所 2002 産技硏論文集 Vol.16 No.-

Unsteady-state temperature distributions and thermal deformations for spindle system with built-in motor according to spindle type are studied. In this analysis, three dimensional model of spindle system is built considering heat transfer characteristics such as natural and forced convection coefficients. Temperature distributions and thermal deformations are analyzed by using the finite element method. Results of analysis according to the spindle type are compared.

뒷채움재 특성변화에 따른 교대구조물 해석

정범석,김광수 동의대학교 산업기술개발연구소 2005 産業技術硏究誌 Vol.19 No.-

The compaction-induced earth pressures are much greater than the at-rest values near the surface of a compacted backfill. At large depth, the overburden pressure induced by the weight of the overlying backfill is significantly larger than the vertical stresses applied during compaction. Therefore, in short walls, the magnitude of the total horizontal force on the wall may be controlled by compaction-induced earth pressures. In higher wall, the total horizontal force on the wall may be controlled by the at-rest pressures for normally consolidated soil backfill. From a series of bridge abutment analyses, various sets of design parameters versus backfill height relationships for different densities and different internal friction angles of the backfill are developed. The influence of changing the backfill material on the design factors for the type of bridge abutment increases with increasing wall heights. Depending on the properties of the backfill material, a certain load combination can give harmful effect to the wall structure specially in the poorly designed drainage systems. The structural design must be adjusted by several methods until the analysis results matched the target values of the design parameters from each code. Therefore, use of new backfill material for the type of bridge abutment is recommended for a close examination of its properties and economical advantages.