• Journal of the Korean Graphic Arts Communication Society
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• v.26 no.2
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• pp.31-43
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• 2008

The functional dyes, which has various optical characteristics that can be applicable to field of electronic, photo electronic, such as sensor or electrode, were synthesized. Physical property and optical stability was studied with preparation of conductive type film as a kind of optical filter of plasma display panel, by adapting neon cut off dye, which can selectively absorbing between 580 and 610nm wavelength. The filter was prepared with PSA resin, which has functional group of - COOH and - OH, as binder. And the characters such as spectroscopy, heat-proof / wet-proof, thermal stability and commerciality, which must be held by functional dyes, were examined. Conductive type film is the kind of film includes only neon cut off dyes. For the neon cut off dyes, cyanine dyes can be applied. And it is observed that spectrum of before and after the durability test are not changed due to stability of dyes, as the result of coating on the mesh film with PSA binder.

• Korean Chemical Engineering Research
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• v.54 no.2
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• pp.157-162
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• 2016

Porous $Co(OH)_2$ nano-flake thin films were prepared by a potential-controlled electro-deposition technique at various deposition voltage (-0.75, -1.0, -1.2, and -1.4 V) on Ti-mesh substrates for supercapacitor application. The potential of electrode was controlled to regulate the film thickness and the amount of $Co(OH)_2$ nano-flake on the titanium substrate. The film thickness was shown to reach the maximum value of $34{\mu}m$ at -1.4 V of electrode potential, where 17.2 g of $Co(OH)_2$ was deposited on the substrate. The specific discharge capacitances were measured to be 226, 370, 720, and $1008mF\;cm^{-2}$ in the 1st cycle corresponding to the films which were formed at -0.75, -1.0, -1.2, and -1.4 V of electrode potentials, respectively. Then the discharge capacities were decreased to be 206, 349, 586 and $866mF/cm^{-2}$, where the persistency rates were 91, 94, 81, and 86%, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.7
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• pp.477-483
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• 2018

A transparent antenna designed on the front glass of an automobile operating in the FM broadcast band(88~108 MHz) is proposed. A transparent antenna designed on the front glass of the automobile to avoid space limitation is typically positioned as a roof-mounted shark-fin antenna. An antenna designed on the front glass can reasonably solve the problems of low reception sensitivity and radiated interference from antennas for other service bands. The front glass has a unique closed-line structure, and this structure causes the surface current to flow to the front glass's surroundings; thus, the first resonance is caused before the broadcast band. Through the use of this closed-line structure, the surface current distribution is controlled, and an antenna for which the first resonance is operating in the frequency-modulated(FM) band can be designed. Moreover, the use of a micro-metal-mesh film that is a transparent electrode, suitable for designing a radio frequency device, enables the antenna to minimize visual perception through its transparency. The measured reflection coefficient($S_{11}$) of the antenna is less than -6 dB, and the average peak gain is -0.9 dB in the FM band. Experiments show that the transparent antenna on the front glass offers both the space and design freedom required to develop future automotive antennas.

• Journal of Hydrogen and New Energy
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• v.32 no.6
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• pp.442-454
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• 2021

The porous transport layer (PTL) is essential to effectively remove oxygen and hydrogen gas from the electrode surface at high current density operation conditions. In this study, the effect of PTL with different characteristics such as pore size, pore gradient, interfacial coating was investigated by multi-layered sintered mesh. A water electrolysis single cell of active area of the 34.56 cm² was constructed, and IV performance and impedance analysis were conducted in the range of 0 to 2.0 A/cm². It was confirmed that the multi-layered sintered mesh PTL, which have an average pore size of 25 to 57 ㎛ and a larger pore gradient, removed bubbles effectively and thus seemed to improve IV performance. Also, it was confirmed that the catalytic metals such as Ni, NiMo coating on the PTL reduced activation overpotential, but increased mass transport overpotential.

• Journal of the Korean Electrochemical Society
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• v.19 no.3
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• pp.63-68
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• 2016

$Li_4Ti_5O_{12}$ is prepared through a solid-state reaction between anatase $TiO_2$ and $Li_2CO_3$ for the negative electrode active materials in quick-charging lithium-ion batteries. The small amount of carbon black (0, 0.5, 1.0, and 3.0 wt%) is added for the reduction of powder agglomeration during heat-treatment. As the amount of the added carbon black increases, the tap density of $Li_4Ti_5O_{12}$ powder gradually decreases. Furthermore, the $Li_4Ti_5O_{12}$ powder prepared with 1.0 wt% of carbon black shows the highest sieved fraction at the powder classification by 325 mesh standard sieve. The $Li_4Ti_5O_{12}$ powders with various contents of carbon black are almost same at the rate capability for the negative electrode materials in lithium-ion batteries.

• Carbon letters
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• v.26
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• pp.18-24
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• 2018

Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of $4.0A/m^2$ and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.146-150
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• 2004

The effects on non-thermal plasma generation by duty Ratio and frequency of pulse voltage were investigated experimentally. For these, a new type of non-thermal plasma generator with mesh electrode was manufactured and it was possible to generate the surface and silent discharge simultaneously by new type of non-thermal plasma generator. Duty ratio and frequency were selected as main parameters to control the movement of electron which is mainly related to the non-thermal plasma generation. The characteristics of non-thermal plasma generation were investigated indirectly by measuring the I-V curve and quantity of ozone generation. The most effective condition of duty ratio and frequency to generate the non-thermal plasma was identified by experiments with manufactured non-thermal plasma generator.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.6
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• pp.95-101
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• 2002

There are many effective parameters to high concentration ozone generation. These parameters became very important elements should be considered before designing ozone generator. After designing, there are many peripheral parameters to greatly affect to high concentration ozone generation also. In this study, of many effective peripheral parameters on high concentration ozone generation, the effects of flow rate of inlet oxygen gas and some kinds of additional gases on ozone concentration were investigated As a result, when inlet oxygen gas was introduced at the range of 0.75［LPM］～2.00［LPM］ the highest ozone concentration of 71145［ppm］ was obtained at 1.25［LPM］. When the additional nitrogen gas was mixed to oxygen gas at the range of 0.0［vol%]～6.4［vol%］ the highest ozone concentration of 73135［ppm］ was obtained at 0.8［vol%］ of nitrogen gas. This showed 3［%］ increasing compared to the case of pure oxygen gas inlet. When the additional argon gas was mixed to oxygen gas at the range of 0.0［vol%］～6.4［vol%］ the highest concentration of 67288［ppm］was obtained at 0.8［vol%］of argon gas. This is decreased value compared to that of introducing the pure oxygen.