• Proceedings of the PSK Conference
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• 2000.10a
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• pp.270.1-270.1
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• 2000

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.35-41
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• 2019

In this study, the fire resistance performance of polymer cement mortars which are used as a representative repair material for section restoration, is evaluated and residual bond strength is measured by considering unity with concrete. According to the evaluation of fire resistance performance of re-emulsification type polymer cement mortars, residual compressive strength was drastically decreased according to heating temperatures with an increase of polymer addition rate, and this seems to be attributable to the application of polymer film. In addition, an explosion phenomenon occurred frequently with an increase of addition rate, so this should be considered when selecting repair materials and processing.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.199-208
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• 2019

This study reports water-resistant oil-in-water (O/W) emulsion-based sunscreening formulations prepared using a poly(ethylene glycol)-poly(${\varepsilon}$-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) triblock polymeric surfactant. As a result of a variety of outdoor recreational activities such as swimming and hiking, consumer needs for development of advanced water-resistant sunscreen formulations are increasing. Water-resistant sunscreens are mostly based on water-in-oil (W/O) emulsions, because they should not be wiped off by water or sweat. However, the W/O emulsion formulations have a disadvantage in that the feeling of use is oily and difficult to remove. On the other hand, the O/W emulsion formulations are excellent in achieving the better skin feel as well as the easier removal. However, it is difficult to provide the O/W emulsion formulations with the water-repelling performance, since re-emulsification likely occurs upon getting touch with water. To solve this problem, this study proposes a O/W emulsion-based sunscreen formulation, a triblock polymeric surfactant having relatively high interfacial tension HLB value (~ 10). This allows the sunscreen formulations to exhibit the improved water repellence function by preventing their re-emulsification. The sunscreen formation system prepared in this study would be useful for diversification of functional sunscreen products, taking advantages of its excellent emulsion stability, UV protection performance, long lasting water-resistant function and selective cleansing effect with only foam cleanser.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.419-425
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• 2001

A dense pellicular solid matrix has been fabricated by coating 4% agarose gel on to dense zironia-silica(ZS) spheres by watr-in-oil emulsification . The agarose evenly laminated the ZS bead to a depth of 30㎛, and the resultin gpellicular assembly was characterised by densities up to 2.39g/mL and a mean particle dimeter of 136 ㎛. In comparative fluidisation tests, the pellicular solid phase exhibited a two-fold greater flow velocity than commercial benchmark ad-sorbents necessary to achieve common values of bed expansion. Furthermore, the perlicular parti-cles were characterised by improved qualities of chromatographic behaviour, particularly with re-spect to a three-fold increase in the apparent effective diffusivity of lysozyme within a pellicular assembly modified with Cibacron Blue 3GA. The properties of rapid protein adsorption/desorp-tion were attributed to the physical design and pellicular deployment of the reactive surface in the solid phase. When combined with enhanced feedstock throughput, such practical advantages recommend the pellicular assembly as a base matrix for the selective recovery of protein products from complex, particulate feedstocks(whole fermentation broths, cell disruptates and biological extracts).

• Journal of the Korea Institute of Building Construction
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• v.18 no.4
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• pp.329-335
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• 2018

The objective of this study is to develop a mortar mixture with high workability and adhesive strength for section jacketing in seismic strengthening technology of existing concrete structures. To achieve targeted requirements of the mortars (initial flow exceeding 200 mm, compressive strength of 30MPa, and adhesive strength exceeding 1MPa), step-by-step tests were conducted under the variation of the following mixture parameters: water-to-binder ratio, sand-to-binder ratio, polymer-to-binder ratio, dosage of viscosity agent, and content of ultra-rapid-hardening cement. The adhesive strength of the mortars was also estimated with respect to the various surface treatment states of existing concrete. Based on the test results, the mortar mixture with the polymer-to-binder ratio of 10% and the content of ultra-rapid-hardening cement of 5% can be recommended for the section jacketing materials. The recommended mortar mixture satisfied the targeted requirements as follows: initial flow of 220 mm, high-early strength gain, 28-day compressive strength of 35MPa, and adhesive strength exceeding 1.2MPa.

• Journal of Pharmaceutical Investigation
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• v.31 no.3
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• pp.191-196
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• 2001

Biodegradable polymeric microspheres were studied for their usefulness as carriers for the delivery of vaccine antigens. However, protein antigen could be denatured during microencapsulation processes due to the exposure to the organic phase and stress condition of cavitation and shear force. Therefore this study was carried out to re-evaluate the degree of protein denaturation during microencapsulation with poly(lactide-co-glycolide) (PLGA) copolymer. PLGA microspheres containing ovalbumin (OVA), prepared by W/O/W multiple emulsification method, were suspended in pH 7.4 PBS and incubated with shaking at $37.5^{\circ}C$. Drug released medium was collected periodically and analyzed for protein contents by micro-BCA protein assay. In order to evaluate the protein integrity, release medium was subjected to the analyses of SDS-PAGE and size exclusion chromatography (SEC). And enzyme-linked immunosorbent assay (ELISA) was introduced to measure the immunoreactivity of entrapped OVA and to get an insight into the three-dimensional structure of epitope. The structures of entrapped protein were not affected significantly by the results of SDS-PAGE and SEC. However, immunoreactivity of released antigen was varied, revealing the possibility of protein denaturation in some microspheres when it was evaluate by ELISA method. Therefore, in order to express the degree of protein denaturation, antigenicity ratio (AR) was obtained as follows: amount of immunoreactivity of OVA/total amount of OVA released ${\times}100(%)$. ELISA method was an efficient tool to detect a protein denaturation during microencapsulation and the comparison of AR values resulted in more accurate evaluation for immunoreactivity of entrapped protein.