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.

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.

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.

광주·전남지역의 무역구조 분석

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

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.

재조합 대장균의 고농도 유가식 배양에 의한 인체 Granulocyte-Colony Stimulating Factor 생산

김범수,유미진 建陽大學校 1999 建陽論叢 Vol.- No.7

Fed-batch fermentation of recombinant Escherichia coli harboring the gene encoding mature human granulocyte-colony stimulating factor (hG-CSF) fused to the gene for the pectate lyase B (pelB) signal peptide of Erwinia caratovora was performed. The fusion protein, pelB-hG-CSF, was produced at a concentration of ca. 1.7 g/L in an inclusion body form.

D8S210 유전자 과변이부위의 클로닝과 한국인에서 집단유전학적 분석을 통한 법의학적 활용성에 관한 연구

한지수,한길로,염범우,황적준 大韓法醫學會 1997 대한법의학회지 Vol.21 No.2

A multi-locus probe. called pHK-450. detecting multiple variable DNA fragments, was constructed by cloning of the 450 bp fragments into pCR?? vector, which could be obtained from amplification of the variable region of the D8S210 locus of human genome with a primer set of UF1. UR1, and UR2. The sequence data shows that the variable region is entirely G-C rich on one strand consisting of tetranucleotide repeat unit (GGAA)n at both margins and internally diversed regions with simple irregular repeat units of GGAA, GGAG, or GGGAA. The genetic complexixty of the resulting individual-specific DNA patterns was investigated by studying a Korean pedigree(both parents and 10 children). HaeIII and HinfI-generated DNA fragments are inherited to their children in a Mendelian manner with segregation ratio of 1:1.05 and 1:1.14. respectively. In the HinfI-digested genomic DNAs, the segregation of up to 25 variable DNA fragments from both parents could be analysed in a single sibship. Most of these variable DNA fragments detected by pHK-450 probe are not paired as allele, which suggests that they may be derived from 23 heterozygous loci. In the HaeIII-digested genomic DNA, 26 variable DNA fragments are segregated from both parents to 10 children. Excluding one allelic and three linked DNA fragments, 22 out of 26 scored DNA fragments may be derived from 23 hetrozygous loci. To determine the variability of DNA fragments, DNA samples from 113 unrelated Korean were digested with HinfI and hybridized using pHK-450 probe. Pairwise comparisons of individual variable DNA fragments show that the polymorphic patterns were highly specific to an individual. The mean probaility(X) that fragments in A individual is present in B individual is 0.0337. From the degree of maxiaml sharing, band approximate estimates of mean allele frequency and homozygosity is calculated being 0.187 and the mean heterozygossity is 89.69%. For pHK-450 probe, the probability that all 10 resolved DNA fragments in the 5-30 kb size range in an individual A are also present in a second unrelated individual B is (0.337)?? or 7.1 X 10??

유회수기의 유체역학적 특성

현범수 韓國海洋大學校 附設 海洋科學技術硏究所 1998 硏究論文集 Vol.7 No.-

해양오염 사고시 유출유의 수거를 위하여 사용되는 유회수기에 대하여 고찰하였다. 논문의 주요 내용은 (1) 유회수기의 종류, 장단점, 성능지표 및 시장현황에 대한 개괄적인 설명과 (2) 유회수 성능에 영향을 미치는 인자들에 대한 고찰, 그리고 (3) 유회수기 분야에 대하여 현재까지 발표된 논문들에 대한 핵심 아이디어들을 소개하였다. 끝으로 (4) 유체역학적 관점에서 본 유회수기의 특성과 해양, 토목, 기계등 유사관련분야의 연구결과가 유회수기 해석에 어떻게 이용될 수 있는지에 대하여 고찰하였다. The hydrodynamic characteristics of oil skimmers are reviewed. The paper consists of (1) introduction of the general aspects of oil skimmers, including kinds, performance indices, current market situations, (2) the analysis of factors affecting oil-skimming, (3) the review of existing papers with a special focus on hydrodynamic problem and finally (4) conclusions and some suggestions. The purpose of this paper is to draw hydrodynamists' attentions on oil skimmer, more broadly on marine oil spill.

인지된 신뢰, 위험, 유용성 및 편의성이 전자정부 민원서비스 사용의도에 미치는 영향 : 온라인 민원 안내와 민원 신청 서비스를 중심으로

김범수,이정,김경규 한국정보사회진흥원 2006 정보화정책 Vol.13 No.4

전자정부 민원서비스 혁신 시스템(G4C) 사업을 추진한 대한민국 정부는 현재 4,700 여종의 정보와 서비스를 통합전자민원창구(www.egov.go.kr)를 통하여 제공하고 있다. 이러한 전자정부 대국민 민원서비스를 그 관여도에 따라 단순 정보 제공 등“민원 안내 서비스”와 인터넷을 통한“온라인 민원 신청 및 발급 서비스”등의 두 가지로 크게 분류하고, 각 서비스 별로 정부에 대한 신뢰, 정부 서비스 이용과정에서 인지된 위험, 편의성, 유용성이 전자정부 민원서비스 혁신시스템(G4C)의 사용의도에 미치는 영향을 연구하였다. 인터넷을 사용하는 성인 3,074명을 대상으로 한 설문 조사를 통하여 (1) 관여도가 높은 전자정부 서비스에서만, 정부에 대한 신뢰가 사용의도에 영향을 미치며, (2) 인지된 위험은 서비스 종류에 따라 다양한 수준의 영향력을 보이고, (3) 서비스 이용 의도에 가장 큰 영향을 미치는 변수는 유용성이며, (4) 편의성은 서비스 이용의도에 직접적인 영향을 미치기보다는 유용성을 매개로 하여 간접적으로 미치는 영향이 더 큼을 보였다.

PVAc 라텍스 접착제의 열적 안정성에 대한 고찰

권재범,이내우,설수덕 한국안전학회 2003 한국안전학회지 Vol.18 No.3

Latex polymers are widely used for adhesive, binder, paint etc. Especially the PVAc(Polyvinyl acetate) latex which manufactured by vinyl acetate and vinyl alcohol as protective colloid is a useful environmentally friendly adhesive. To increase useful property of PVAc latex, this study was carried out for checking thermal characteristics and physical condition of PVAc latex by DSC, FT-IR, Pyrolyzer GC-MS. The activation energies of thermal decomposition for 40, 48, 56, 64% solid content of PVAc latex were found as 28.1~36.0kcal/mol by Kissinger's method and 17.2~22.0kcal/mol by DSC method. Actually, reasonable solid content could be consiered as 56% because of activation energy and adhesive characteristics. According to the effect of protective colloid for 4, 10, 15, 20wt%, the activation energy shows same tendency to both method and in case of 15wt% has been found as the highest activation energy. The mechanism of thermal decomposition was mainly estimated by main chain scission, not by side group on FT-IR analysis. Main component of Pyrolyzer GC-MS result were consisted of CH₃COOH, CH₃, H₂O and light gases(CO, CO₂, CH₄ etc).