• Membrane Journal
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• v.9 no.2
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• pp.126-131
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• 1999

Diagnostic membranes by using multi-layered gelatin films were prepared to measure blood glucose level of diabetics. Maximum diffusion rates through multi-layered gelatin film were measured at various concentration of glucose in plasma or blood. The effects of storage temperatures on the diffusion rates of glucose were studied after storage of 3 days, 2 weeks and 4 weeks at various temperatures. The stabilities of diagonostic membranes with multi-layered gelation films were examined at RH 80%.

• Journal of Korean Society of Disaster and Security
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• v.14 no.1
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• pp.23-40
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• 2021

In the era of the global coronal 19 pandemic, there is a risk of cross-infection in hospitals at the stage where treatments and vaccines are currently being developed and marketed, so individuals should enhance their acquired immunity and generalize their living systems by the performance of copper ions in the social environment. In order to prevent the spread of infection, the need for anti-bacterial film and its efficacy were analyzed through anti-viral performance tests based on research and development cases of worldwide and immemorial time. he Korea Construction Research Institute (KCL) has received anti-bacterial performance certification and anti-viral test scores from the "National Approval Performance Certification Agency." At the time, NCCP 43326 Human Corona virus (BetaCoV/Korea/KCDC03/2020), which was approved by the Centers for Disease Control and Prevention, was introduced to ensure that the activity rate of infected cells was satisfied in the anti-viral performance test. Anti-proliferation measures for the Corona 19 virus require a quality clinical trial study comparing the experimental group within the glass space where the antiviral copper film is constructed with the comparator of the same condition without copper film.

• Membrane Journal
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• v.18 no.3
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• pp.256-259
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• 2008

In this study, graphite or zeolite 4A was mixed with poly(acrylonitrile-butadiene-strene) (ABS) to make hybrid films, and permeation characteristics of air and water vapor through these films were investigated. In all cases, gas permeabilities of hybrid films were lower than that of pure ABS films. The permeability decrease of oxygen was slightly larger than that of nitrogen, resulting in the little decrease of $O_2/N_2$ selectivity. In addition, the water vapor transfer rates (WVTR) of hybrid films were about half of ABS film's. The decrease of permeabilities may be owing to the increase of tortuosity for diffusion in hybrid films.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.593-598
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• 2013

In this study, we have evaluated the water absorption phenomenon of photoresist dry film, which is commonly used to build circuits on PCB (Printed Circuit Board) by photolithography, by using ATR-FTIR (Attenuated Total Reflectance-Fourier Transform Infrared). We have firstly observed significant change in fracture mode of dry film with respect to temperature and humidity, which we assumed the material transition from ductile to brittle. Secondly, we have established the process of absorption test for determining the diffusion coefficients of water into the dry film both with gravimeter and ATR-FTIR. We have successfully calculated the diffusion coefficients for each environmental conditions from the results which we achieved by gravimeter and ATR-FTIR. Compared to the gravimeter which is a conventional method for absorption test, the ATR-FTIR method in this study has been found to be very easy to use and have the same accuracy as gravimeter. Moreover, we are expecting to use the ATR-FTIR as an appropriate method to study the absorption phenomena related to any kinds of solvent and polymer system.

• Korean Journal of Optics and Photonics
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• v.32 no.4
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• pp.163-171
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• 2021

Conventional white light-emitting diodes (LEDs) for lighting applications consist of blue LEDs and yellow phosphors, the spectrum of which lacks deep red. To improve the color-rendering characteristics of white LEDs, a red quantum-dot film was applied to the diffuser plate of LED lighting. The mean free paths of the quantum dots and the concentration of the TiO₂ particles in the diffuser plate were adjusted to optimize the optical structure of the lighting. The color-rendering index (CRI) was greater than 90 for most conditions, which demonstrates that adoption of the red quantum-dot film is an effective way for improving the color-rendering properties of conventional white LEDs. The angular dispersion of color coordinates could be removed by utilizing the optical cavity formed between the diffuser plate and the reflector on the bottom of the lighting, where multiple passages of the light through the quantum-dot film reduced the differences in optical path length depending on the viewing angle.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1297-1303
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• 2012

In this paper, the standard procedures for measuring the moisture sorption properties of thin polymeric materials such as polyethylene terephthalate (PET) by using the thermo-gravimetric method to characterize the moisture diffusion in the polymer are presented, and the sorption properties are quantified. The moisture diffusivity and solubility are characterized to investigate the effect of temperature and humidity on the moisture sorption properties according to the Arrhenius equation. The validation of the obtained sorption properties using thermogravimetry is discussed with the measured permeability based on Fickian diffusion. The nonlinear behavior of the concentration dependent moisture diffusion is investigated experimentally, and the nonlinearity is characterized numerically for the case of having an interface with an inorganic material such as a metal. The Fickian/Non-Fickian model based on the obtained moisture sorption properties is compared and discussed.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.311-316
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• 2012

We are investigated to an electrochemical characteristic for Langmuir-Blodgett (LB) films by cyclic voltammetry method. The phospholipid compound was deposited by using the LB method on the Indium tin oxide(ITO) glass. We tried to measure the electrochemical by using cyclic voltammetry with three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) in 0.5, 1.0, 1.5 and 2.0 N $NaClO_4$ solution. A measuring range was reduced from initial potential -1350 mV, continuously oxidized to 1650 mV. As a result, LB films of the phospholipid compounds are appeared irreversible process caused by only the oxidation current from the cyclic voltammogram. The diffusivity(D) effect of LB films decreased with increasing of phospholipid compound amount.

• Polymer(Korea)
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• v.25 no.2
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• pp.151-160
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• 2001

Polymeric membranes consisting of poly(d,1-lactide) as a polymer matrix and crystallizable progesterone as a drug were prepared by coagulating polymeric solutions. The homogeneous casting solutions in dimethyformamide were solidified by using three different coagulating processes : solvent evaporation under vacuum, solvent extraction via immersion into the nonsolvent bath, or vapor exposure at high humidity condition. With solvent removal via evaporation under vacuum, the cast solution film was vitrified to form a homogeneous film containing progesterone of spherical shape distributed evenly in the film. Being prepared by solvent extraction via immersion into a water bath, the resulting membrane showed an asymmetric structure, with progesterone of big crystallites distributed unevenly in the structure. On the other hand, the coagulation under high humidity transformed the cast film into a sponge-like structure, where progesterone took a shape like flake.

• Proceedings of the Optical Society of Korea Conference
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• 2007.02a
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• pp.249-250
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• 2007

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.449-450
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• 2008

본 연구에서 우리는 4축 회전이 가능한 휘도측정기를 가지고 확산판 대신, PLF를 사용한 edge형 BLU의 광시야각, 휘도 및 스펙트럼을 측정하였다. 이에 따라, 우리는 조명설계 프로그램 'LightTools'을 이용하여 PLF와 프리즘 시트가 최적화 되도록 설계하여 분석하였다.