• Membrane Journal
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• v.25 no.5
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• pp.385-390
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• 2015

To determine the pervaporation separation characteristics of IPA/water mixtures, PEI/PDMS hollow fiber membrane module commercialized by Airrane Co. was subjected to both lab and pilot tests. The flux of $0.52kg/m^2h$ and IPA concentration of 68.5% at $25^{\circ}C$ were obtained whereas the $1.368kg/m^2h$ and 61.2% were measured at $55^{\circ}C$. In order to realized the durability of the module, the long-term test (at $50^{\circ}C$) of 100 days has been conducted and as a result, the flux $1.03{\sim}1.15kg/m^2h$ and IPA concentration 61.8~62.5% were maintained with the initial values.

• Membrane Journal
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• v.33 no.6
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• pp.377-382
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• 2023

In this study, a PEBAX/PVDF composite membrane was fabricated, and its pervaporation performance was tested in an ethanol/water mixture. In addition, we attempted to improve the pervaporation performance of the composite membrane by forming a ZIF-8 layer on the surface of the PVDF substrate. The thickness of selective layer was optimized by comparing the pervaporation performance depending on the PEBAX thickness. A pervaporation test was performed on the Ethanol/Water mixture. As a result, the composite membrane using PVDF substrate with ZIF-8 layer had a flux of 1.98 kg/m²h and separation factor of 3.88, showing higher values of both permeation flux and selectivity than the composite membrane using bare PVDF substrate.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.32-39
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• 2005

When PFC(Perfluorocarbonate) decontamination technology is applied to removal of radioactive contaminated particulate adhered at surface during the operation of nuclear research facilities, it is necessary to develop a filtration equipment to reuse of PFC solution due to high price, also to minimize the volume of second wastewater. Contaminated characteristics of hot particulate was investigated and a filtration process was presented to remove suspended radioactive particulate from PFC decontamination wastewater generated on PFC decontamination. The range of size of hot particulate adhered at the surface of research facilities measured by SEM was $0.1{\sim}10{\mu}m$. Hot particulate of more than $2{\mu}m$ in PFC contamination wastewater was removed by first filter and then hot particulate of more than $0.2{\mu}m$ was removed by second filter. Results of filter experiments showed that filtration efficiency of PVDF(Poly vinylidene fluoride), PP(Polypropylene), Ceramic filter was $95{\sim}97\%$. A ceramic filter showed a higher filtration efficiency with a little low permeate volume. Also, a ceramic of inorganic compound could be broken easily on experiment and has a high price but was highly stable at radioactivity in comparison of PVDF and PP of a macromolecule which generate $H_2$ gas in alpha radioactivity environment.

• Journal of Life Science
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• v.27 no.7
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• pp.812-816
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• 2017

Although amaranth, a red-colored tar dye, is usually used in foods, cosmetics, and pharmaceutics, its bioavailability and intestinal absorption have not previously been investigated. Therefore, the purpose of this study was to investigate the pharmacokinetics properties and intestinal permeability of amaranth in rats following the intravenous and oral administration of this dye. Amaranth rapidly disappeared from the plasma following the intravenous injection, with a half-life of 38.8 minutes. However, the plasma concentration of amaranth was increased to 400 minutes following the oral administration of amaranth, and the absorption time and bioavailability of amaranth were calculated to be 356 minutes and 55.6%, respectively. This suggests that once amaranth exists in the gut, this dye may be efficiently and effectively absorbed. Consistent with this result, the intestinal permeability of amaranth was comparable to atenolol, a marker compound of moderate permeability, and to one-third of caffeine's intestinal permeability (a highly permeable compound). In conclusion, a significantly long absorption time and substantial intestinal absorption of amaranth was observed following the oral administration of amaranth at a dose of 300 mg/kg in rats, despite the rapid elimination of this dye from the plasma. These results may suggest the necessity of a careful and limited use of amaranth dye when it is added to food, lip-care cosmetics, and orally administered pharmaceutics.

• Membrane Journal
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• v.7 no.1
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• pp.39-47
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• 1997

The self-designed membrane system was tested to examine the performance of the hollow fiber type polysulfone ultrafiltration(UF) membrane for the treatment of pure water(the 3rd treated water). The molecular weight cut-off's (MWCO) of the membranes used in this study were 5, 000 and 10, 000, respectively. The recovery rate, the ratio of permeate flow rate to the feed flow rate, increased as the temperature rose. The values of MWCO obtained in this study, using 2, 000 ppm polyethylene glycol and dextran solutions with various molecular weight, showed higher values than those suggested by SKI. Based on the results of the primary experiments, the water of the Gongji-stream, in which water quality is deteriorated by the inflow of domestic wastewater, was selected for the UF membrane test. Biological oxygen demand(BOD), total solids, and turbidity of the treated water had much lower values than those of the source water. Therefore, this study confirmed the possibility of the domestic water treatment using the hollow fiber type UF membrane.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.235-245
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• 2016

In this study, we examined the effects of various molecular weights (1, 10, 50, 100, 660, and 1500 kDa) of sodium hyaluronate (HA), which were prepared by enzyme hydrolysis, on the collagen synthesis, anti-inflammation and skin absorption. These HA did not significantly affect the viability of human dermal fibroblast Hs68 cells. Among them, 1500 kDa, 50 kDa HA most significantly increased collagen production by 59%, and 50% in the Hs 68 cells, respectively. Whereas 1500 and 660 kDa HA hardly pass through mouse transdermis membrane, lower molecular weights (1, 10, or 50 kDa) of HA showed time-dependent increase in skin permeation. HA of 50 kDa showed highest anti-inflammatory effects by reducing nitric oxide and tumor necrosis factor-${alpha}$ production in the RAW 264.7 cells, comparing to other HA (1, 10, and 100 kDa HA). Recently, there is no report about anti-wrinkle and anti-inflammatory effects and skin permeation of different molecular weights HA (1, 10, 50, 100, 660 and 1500 kDa), which were produced by enzyme hydrolysis. These results suggested that 50 kDa HA can be potent candidates for the development of effective anti-aging and anti-wrinkle cosmetic agents. The results of this study demonstrated that among those HA with different molecular weights, 50 kDa HA showed highest anti-inflammatory activity, significant capability to induce collagen synthesis and high level of skin permeation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.3
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• pp.121-129
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• 2004

The different types of coastal souctures have been constructed for the protection of coastal region from the incident waves. Among them. the permeable submerged breakwater has been widely used as a wave dissipater and sediment transport controller because of its excellent advantages in scenery effects, construction efficiency and environment aspects. This study numerically investigated the characteristics of wave energy variations and transmission coefficient at the rear of the permeable submerged breakwater installed in the irregular wave field. To analyze it's performance numerically, a two-dimensional numerical wave flume based on VOF method was used. A frequency spectral analysis showed that the spectral peak moved to the short-period in the one-row submerged breakwater, and the wave energy was distributed evenly for the whole period in the two-row submerged breakwater in the case of breaking on the submerged breakwater. The spectral peak was shown to be converged within the significant wave period at the rear of the permeable submerged breakwater in the case of non-breaking conditions. From the result of transmission coefficients analysis. it was confirmed that a considerable quantity of wave energy was transmitted to the rear of the permeable submerged breakwater in the case of non-breaking rather than breaking.

• Tunnel and Underground Space
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• v.21 no.4
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• pp.287-296
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• 2011

We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than $1.0{\times}10^{-18}\;m^2$ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 MPa. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.129-133
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• 2000

환경대기중 입자상물질의 검사방법은 환경부고시 97-98호(97. 11. 5)에 의거 고용량공기포집법(high volume air sampler), 저용량공기포집법(low volume ai sampler), 광산란법 및 광투과법 그리고 $\beta$흡수법 등으로 되어 있다. 이중 고용량공기포집법, 저용량공기포집법, $\beta$흡수법등은 중량법의 범주에 드는 측정법으로 되어 있다. 이들 방법 중 먼지채취전후의 무게를 직접 칭량하여 분석하는 고용량공기포집법은 총부유먼지의 측정법으로, 저용량공기포집법은 $PM_{10}$의 분석에 이용되는 것이며 $PM_{10}$ 고용량공기포집기($PM_{10}$ high volume air sampler) 또는 $PM_{10}$ 분석에 이용될 수 있다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.58-63
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• 2003

폐쇄형 묘생산 시스템(closed system for transplants production)은 자연광이 투과되지 않도록 단열재로 구성되어 있어 시스템 내부와 외부의 공기, 물, 열 등의 교환이 기본적으로 제한된다. 또한 식물 생육에 필요한 관수량, 내부에 적절한 습도를 유지시켜 주기 위한 가습량 및 공조기구에 의한 제습량 등이 시스템 내에서 평형을 이루며 순환한다. (중략)