• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.10a
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• pp.68-71
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• 2006

Multi-component $ZnO-In_2O_3-SnO_2$ thin films have been prepared by RF magnetron co-sputtering using targets composed of $In_3Sn_4O_{12}$(99.99%) [1] and ZnO(99.99%) at room temperature. $In_3Sn_4O_{12}$ contains less In than commercial ITO, so that it lowers cost. Working pressure was held at 3 mtorr flowing Ar gas 20 sccm and sputtering time was 30 min. RF power ratio [RF1 / (RFI + RF2)] of two guns in sputtering system was varied from 0 to 1. Each RF power was varied $0{\sim}100W$ respectively. The thickness of the films was $350{\sim}650nm$. The composit ion concentrations of the each film were measured with EPMA, AES and XPS. The low resistivity of $1-2\;{\times}\;10^3$ and an average transmittance above 80% in the visible range were attained for the films over a range of ${\delta}\;(0.3\;{\leq}\;{\delta}\;{\leq}\;0.5)$. The films also showed a high chemical stability with time and a good uniformity.

• Journal of the Korean Wood Science and Technology
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• v.34 no.5
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• pp.29-41
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• 2006

This study was to investigate the effect of adding additive as tannin, rice husk and charcoal, for reducing the formaldehyde emission level, on the adhesion properties of urea-formaldehyde (UF) resin for particleboard. We controlled the hot-pressing time, temperature and pressure to determine the bonding strength and formaldehyde emission. Blends of various UF resin/additives (tannin, rice husk and charcoal) compositions were prepared. To determine and compare the effect of additives (tannin, rice husk and charcoal) content, 0, 5, 10 and 15%, by weight of UF resin, were used. $NH_4Cl$ as hardener added. To determine the level of formaldehyde emission, we used the desiccator, perforator and 20 L-small chamber method. The formaldehyde emission level decreased with increased additions of additive (except rice husk). Also, increased hot-pressing time decreased formaldehyde emission level. At a charcoal replacement ratio of only 15%, the formaldehyde emission level is under F ✩ ✩ ✩ ✩ grade (emit < $0.3mg/{\ell}$). Curing of the high tannin additive content in this adhesive system indicated that the bonding strength increased. But, in the case of rice husk and charcoal, the bonding strength was much lower due to the inorganic substance. Furthermore, rice husk was poor in bonding strength as well as formaldehyde emission than tannin and charcoal.

• Journal of Environmental Science International
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• v.24 no.7
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• pp.893-905
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• 2015

This study analyzes the correlation between Western Pacific (WP) teleconnection pattern index (WPI) in April during 1954-2008 and rainfall amounts in the same month. Based on the results, it is identified that there have been strong positive correlations between central China, Korea and the southwestern part of Japan in the East Asian region. Through differences between 10 positive WP years and 10 negative WP years selected from the April WPI excluding ENSO years, it is found that rainfall amounts increase in April of positive WP years due to the following characteristics. Increases in rainfall amounts are evident in the East Asian middle latitudinal region where the positive correlation between the two variables is the highest and this is because anomalous southwesterlies are strengthened in the East Asian middle latitudinal region due to the spatial pattern of a south-low-north-high anomalous pressure system centered on this region that is made by anomalous anticyclones centered on the southeastern side of the region and other anomalous anticyclones centered on the northeastern side of the region. In addition, anomalous westerlies (jet) are strengthen in the upper troposphere of the East Asian middle latitudinal region and as a result, anomalous upward flows are strengthened in this region and thus anomalous warm air temperatures are formed in the entire level of the troposphere in the region. In addition to atmospheric environments, anomalous warm sea surface temperatures are formed in the seas in the East Asian middle latitudinal region to help the rainfall amount increases in the East Asian middle latitudinal region.

• Journal of the Korean Ceramic Society
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• v.36 no.9
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• pp.937-945
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• 1999

In an effort to protect a RBSC(reaction -bonded SiC) tube SiC films from methyltrichlorosilane(MTS) by low pressure chemical vapor deposition were deposited in hydrogen atmosphere on the RBSC(reaction-bonded SiC) substrates over a range of input gas ratio(${\alpha}=P_{H2}/P_{MTS}=Q_{H2}/Q_{MTS}$=1 to 10) and deposition temperatures(T=1050~1300$^{\circ}C$). At the temper-ature of 1250$^{\circ}C$ the growth rate of SiC films increased and then decreased with decreasing the input gas ratio. The microstructure of SiC films was changed from granular type structure exhibiting (111) preferred orientation in the high input gas ratios to faceted columnar grain structure showing (220) in the low input gas ratios. The similar microstructure change was obtained by increasing the deposition temperature. These results were closely related to a change of deposition mechanism. Double layer structure having granular type and faceted ciolumnar grain structure from the manipulation of mechanism. Double layer structure having granular type and faceted columnar grain structure from the manipulation of the input gas ratio without changing the deposition temperatue was successfully fabricated through in -site process.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.534-539
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• 2010

The adsorptive removal of organic sulfur compounds including tert-butylmercaptane(TBM), tetrahydrothiophene(THT) and dimethylsulfide(DMS) in methane was investigated over NaY and copper-exchanged NaY(CuNaY) zeolites at 303 K and atmospheric pressure. In the ternary adsorption system, the preferential adsorption of THT over other sulfur compounds on NaY and the concurrent adsorption of all sulfur compounds on CuNaY were achieved, which could be explained by the breakthrough curve, the temperature-programmed desorption, and the apparent activation energy for desorption. The sulfur uptake capacity of CuNaY(2.90~3.20 mmol/g) was much higher than that of NaY(0.70~0.90 mmol/g). A comparative study indicated that the $Cu^{1+}$ sites and acidity of CuNaY were probably responsible for the strong interaction with sulfur atom and high sulfur uptake abilities.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2736-2744
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• 2013

In this paper, we present a Smart Water Treatment Plant using Zigbee USN devices and a real-time monitoring system in K-water Flow Meter Calibration Center Building. For verification, the data of vertical type WTP such as flow rate, pressure, water level and water temperature are obtained by the Zigbee USN devices, operating in 2.45 GHz band, and be wirelessly surveilled by the real-time monitoring system. The received data from the sensor is transmitted to the data processing device, and then the processed data can be monitored on a smart phone. Consequently, the pilot plant based on the low-cost and high-efficiency USN has been developed with the performance analysis for the communication network and remote monitoring system on mobile devices.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.560-565
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• 2005

Catalytic performances of zeolite catalysts such as H-mordenite(HM), H-Beta$(H{\beta})$, H-USY(HUSY) for the transmethylation between 1-methylnaphthalene(1-MN) and 2-methylnaphthalene(2-MN) were investigated in a fixed-bed flow reactor. $H{\beta}$ showed higher and more stable conversion than others to exhibit a high and stable 2-MN/1-MN ratio of 2.3 and 2,6-DMN/2,7-DMN ratio of 1.3 at the $1^{st}$ hour of time on stream under the reaction conditions as follows: reaction temperature of $350^{\circ}C$, reaction pressure of 1.5 MPa, WHSV of $2.7g_{feed}/g_{cat}{\cdot}h$ and the molar ratio of 1-MN and 2-MN of 1:1. The catalytic behavior has been discussed in relation with the catalyst pore structure and acidity.

• Journal of Hydrogen and New Energy
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• v.10 no.4
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• pp.191-196
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• 1999

4-probe resistivity measurement technique was used to study hydrogen A-D(Absorption-Desorption)kinetics on Pd films(18 to 67nm thick) from 25 to $50^{\circ}C$, from 0 to 5 torr hydrogen pressure. Pd films were made on sapphire substrate by thermal evaporation technique under high vacuum at room temperature. Upto about 100 hydrogen A-D cyclings, no pulverization was observed, but film was detached partially from substrate. Forward reaction and backward reaction rate were analyzed separately. The activation energies of hydrogen A-D processes were obtained from the Arrhenius plot of the reaction rates. The activation energies of Pd films are not strongly dependent on the thickness of the film. But the activation energy of very thin film( l8nm thick) was smaller than the others.

• Journal of IKEEE
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• v.14 no.3
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• pp.244-249
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• 2010

We fabricated optical sensor system that take a measurement particles using a line-CCD in ocean. To measure particles, we used 680nm laser diode which is appropriate. we tested to operate optical system in water tank and ocean. It has performance that detected signal of sensors transfer microprocessor, FPGA as long as move up and down it's motion. The system algorithm also analysis output -pressure, temperature, particle numbers in depth.-For experiment, our particle sensor system has high accuracy counter. therefore, we proposed that a line-CCD is available on optical sensor system in ocean.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.6
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• pp.48-56
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• 1989

Contact-type linear image sensors for facsimile have been fabricated by means of rf glow discharge decomposition method of silane. The dependence of their electrical and optical properties on rf power, $SiH_4$ flow rate, ambient gas pressure, $H_2SiH_4$ ratio and substrate temperature are described. The a-Si:H monolayer demonstriated photosensitivity of 0.85 and $I_{ph}/I_d$ ratio of 100 unger 100 lux illumination. However, this monolayer has relatively high dark current due to carrier injection from both electrodes, resulting in low $I_{ph}/I_{dd}$ ratio. To suppress the dark current we have fabricated $SiO_2/i-a-Si:H/p-a-Si:H:B$ multilayer film with blocking structure. The photocurrent of this multilayer sensor with 6 V bias became saturated ar about 20nA under 10 lux illumination, while the dark current was less than 0.2 nA. Moreover, the spectral sensitivity of the multilayer film was enhanced for short wavelength visible region, compared with that of the a-Si:H monolayer. These results show that the fabricated photocon-ductive film can be used as the linear image sensor of the facsimile.