• International Journal of Internet, Broadcasting and Communication
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• v.6 no.1
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• pp.13-15
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• 2014

We develop a method to fabricate a flexible thin film audio systems using polyvinylidene fluoride(PVDF). The system we designed showed the properties of increased flexibility, transparency, and sound pressure levels. As an input port of two terminals, transparent oxide thin film with a low resistivity is adopted. In order to provide dielectric insulation, a transparent insulating oxide thin film is coated to obtain double-layered structure. In the range of visible light, the output from the output of the system showed a increased and improved sound pressure level. The piezoelectric polymer film of PVDF is used to produce mechanical vibration due to the applied electrical voltage signal. An analog electric voltage signal is transformed into sound waves in the audio system.

• Journal of Pharmaceutical Investigation
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• v.39 no.4
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• pp.257-261
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• 2009

Effective therapeutics for renal failures have not yet been developed until now. Recently, there was a report showing that Wen-pi-tang-Hab-Wu-ling-san (WHW) prescriptions had the potential to prevent renal failures through the increased expression of HSP-27 and HSP-72 after ischemia/reperfusion. Therefore, formulation studies by pH-specific released systems were carried out to exhibit the optimal activity of WHW prescriptions in this study. WHW prescriptions were separately extracted using water into two parts of stomach-released (SR) and intestine-released (IR) extracts. Subsequently, the double-layered tablet was prepared using the SR extracts and pharmaceutical additives and enteric-coated IR tablet. Dissolution studies were carried out to figure out the release of cinnamic acid and icarrin from SR tablet, IR tablet and double-layered tablet, respectively. The complete release of cinnamic acid from SR tablet showed 90min after dissolution in pH 1.2 and insignificant drug released from IR tablet. As well as, icarrin from IR tablet completely released in pH 6.8 and 7.4 as enteric-coating film dissolved.

• Journal of the Korean Graphic Arts Communication Society
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• v.9 no.1
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• pp.1-11
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• 1991

In this reseach, double-layered photoconductor consist of the carrier generation layer(CGL) of $\varepsilon$ type copper phthalocyanine thin film by an aqueous coating method and the carrier transport layer(CGL) of polyvinyl carbazol(PVK) by spin coating. We inverstigated effect of the surfactant solution and cathod electrolysis to the crystal type of $\varepsilon$-CuPc in CGL with TEM, SEM and X- ray diffraction spectroscopy and studied the mechanism of an aqueous coating for the preparation of CGL. The effect of the washing of CGL about the electrophotographic characteristics of the $\varepsilon$-CuPc/PVK doublelayered photoconductors is studied also.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.436-437
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• 2008

Flexible CIGS thin film solar cell was fabricated using STS430 plate as a flexible substrate in this work. A diffusion barrier layer of $SiO_2$ thin film was deposited on STS430 substrate by PECVD followed by deposition of double layered Mo back contact. After depositing CIGS absorber layer by co-evaporation, CdS buffer layer by chemical bath deposition, ZnO window layer by RF sputtering and Al electrode by thermal evaporation, the solar cell fabrication processes were completed and its performance was evaluated. Corresponding solar cell showed an conversion efficiency of 8.35 % with $V_{OC}$ of 0.52 V, $J_{SC}$ of 26.06 mA/$cm^2$ and FF of 0.61.

• Membrane Journal
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• v.12 no.4
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• pp.240-246
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• 2002

New polysulfone scintillation proximity membranes were prepared by impregnating Cerium Activated Yttrium Silicate (CAYS), an inorganic fluor, in a membrane structure. The membranes were applied to detect the radionuclide contamination directly without the aid of a scintillation cocktail. The preparation of membranes was divided into two processes. A supporting polymer film was made of casting solutions consisting of polysulfone and solvent, their cast film being solidified by vacuum evaporation. CAYS-dispersed polymer solutions were cast over the first, solidified polymer films and coagulated either by evaporating solvent or by exchanging solvent in the solution with nonsolvent in a coagulation bath. The prepared membranes had two distinguished, but tight1y attached, double layers: one is the supporting layer of dense polymer film and the other the detecting layer consisting of CAYS and polymer. The radionuclide counting results revealed that the prepared membranes were efficient to monitor radioactivity contamination with reliable counting ability.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.97-104
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• 2004

Double-layered polysulfone composite films, containing cerium activated yttrium silicate (CAYS) as a flour, were prepared from double casting of two polymeric solutions, and their morphology and physical strength were superior to those of single-layered composites. The prepared polymeric films consist of a dense bottom layer and a CAYS-holding top layer. The former is made of coagulating the polysulfone and methylene chloride binary solution and works as a supporter to improve the composite's physical strength, while the latter holding the inorganic fluor plays a role as an active site to detect the radioactive contamination. The prepared films revealed two distinguished, but tightly attached, double layers, their attachment being identified by morphology of the interface between two layers. As prepared by water immersion coagulation, the films have highly developed macropores, compared with a dense structure in the film prepared by evaporation. In the radionuclide detection test of the CAYS-impregnated composites, the films have reliable detection capacity at a radionuclide spotting test. The double-layered composites with the dense support layer show a better stability in holding the radionuclides spotted on the surface as well as an improvement in physical strength, compared with the single-layer composites having shortcomings such as being too porous or being brittle.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.27-28
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• 2013

This study investigates the effect of a protective layer on the level of carbonation resistance of concrete. For the protective layer, a PE film, bubble sheets, double layered bubble sheets and styroform were placed in a mold before placing the concrete. In addition, PE film was retrofitted by attaching on the surface of the substrate concrete with a glue. Results showed that the carbonation depths of the control concrete were 4.6 mm and 5.2 mm at one week and two weeks exposure in an accelerated carbonation chamber, whereas the concrete with all types of protective layer except PE flim did not allow the ingress of carbon dioxide during the same period.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.7
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• pp.102-108
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• 2013

In manufacturing of solution-processed organic electronic devices, a spin coating method is frequently used, but which has a big problem. Solvent in a solution has a decisive effect such as physical and chemical damage for successive solution-based film deposition. Such a severe damage by solvent restricts for fabricating building blocks of multi-layered films from solutions. In this work, it will be shown that a proper combination of well-known solvents gives a chance to fabricate multi-layered film, also this new method was applied to make organic field effect transistor. Two types of bottom gate, bottom contact transistors were fabricated, one of which is fabricated by conventional single spin coating method, the other fabricated by double spin coating method. Compared with the electrical characteristics in a single spin coated transistor, the leakage current between source and gate electrode was decreased, ON state current was increased, and the extracted saturation mobility was multiplied more than 2.7 time for double spin coated transistors. It is suggested that the multiple coated gate dielectric structure is more desirable for high performance organic ferroelectric field effect transistors.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.55-56
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• 2006

We investigated the diffraction grating efficiency by the DPSS laser beam wavelength to improve the diffraction efficiency on AsGeSeS & Ag/ AsGeSeS thin film. Diffraction efficiency was obtained from DPSS(532nm)(P:P)polarized laser beam on AsGeSeS, Ag/ AsGeSeS and AsGeSeS/Ag/AsGeSeS thin films. As a result, for the laser beam intensity, 0.24 mW, single AsGeSeS thin film shows the highest value of 0.161% diffraction efficiency at 300 s and for 2.4 mW, it was recorded with the fastest speed of 50 s, which the diffraction grating forming speed is faster than that of 0.24 mW beam. Ag/ AsGeSeS and AsGeSeS/ Ag/ AsGeSeS multi-layered thin film also show the faster grating forming speed at 2.4 mW and higher value of diffraction efficiency at 0.24 mW.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.04a
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• pp.93-94
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• 2022

The presence of chloride (Cl-) ions in environments causes localized corrosion resulting decrease the durability of the structures. In this study, 5% Mg containing Al alloys (Al-5Mg) wire used vis-à-vis compared its corrosion resistance with pure Al in 3.5wt.% NaCl solution with exposure periods. Initially both wires exhibited identical open circuit potential (OCP) attributed to the presence of native oxide film on the surface but with the exposure periods it shifted towards active direction owing to the dissolution of oxide film. The pure Al continuously shifted the OCP towards active direction while Al-5Mg shows stabilization of OCP after 8 days of exposure. The OCP of Al-5Mg is slightly higher compared to pure Al wire owing to the activeness of Mg. The total impedance of the Al-5Mg alloy is almost three times greater than pure Al with exposure periods in 3.5 wt.% NaCl solution. It might be formation of Al-Mg LDH (layered double hydroxide) thin film onto the surface.