• Environmental Engineering Research
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• v.15 no.3
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• pp.157-161
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• 2010

Forest soils are often nitrogen-limited, and nitrogen input to forest soils can cause substantial changes in the structure and functions of a soil ecosystem. To determine the effects of nitrogen input on methane oxidation and the microbial enzyme activities, manipulation experiments were conducted using nitrogen addition to soil samples from Mt. Jumbong. Our findings suggested that the addition of nitrogen to the soil system of Mt. Jumbong did not affect the microbial enzyme activities. Conversely, the addition of nitrogen affected the rate of methane oxidation. Inorganic nitrogen in soils can inhibit methane oxidation via several mechanisms, such as substrate competition, toxic effects, and competition with other microbes, but the inhibitory effects are not always the same. In this research, seasonal changes were found to produce different inhibitory factors, and these different responses may be caused from differences in the methantrophic bacteria community structure.

• Corrosion Science and Technology
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• v.3 no.1
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• pp.26-29
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• 2004

Metal plated plastics are becoming more prevalent in materials of communication parts. A new technique MmSH is a process of injecting plastics to produce innovated physical properties compared to the conventional injection process. This study involves two ways of coating plastics Ni by electroless plating and varying bath and plasma treatment for improved adhesion strength between plating layer and surface. MmSH injection processed ASS with plasma treated after neutralization showed a superior adhesion force and a gloss and rate of deposition when it was in pH 7.5. On the other hand, conventional injection processed ASS was in pH 6.5.

• Corrosion Science and Technology
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• v.10 no.3
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• pp.87-94
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• 2011

The typical corrosion prevention method inside the steel upper box girder in a suspension bridge involves the use of paints. However, in an effort to reduce environmental impact and cost, the suspension portion of the Yeongjong Bridge, Korea utilizes dehumidification systems to control humidity and prevent corrosion inside its box girder. Maintaining a uniform humidity distribution at the proper level inside the box girder is critical to the successful corrosion control. In this study, the humidity and the resultant atmospheric corrosivity inside the box girder of the Yeongjong Bridge was monitored. The corrosion rate of the steel inside the box girder was obtained using thin-film electrical resistance (TFER) corrosion sensors. Time-of-wetness (TOW) measurements and the deposition rates of atmospheric pollutants such as $Cl^{-}$ and $SO_{x}$ were also obtained. Classification of the atmospheric corrosivity inside the box girder was evaluated according to ISO 9223. As a result, no corrosion was found in the upper box girder, indicating that the dehumidification system used in the Yeongjong Bridge is an effective corrosion control method.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.294-297
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• 2000

Boron Phosphide films were deposited on the glass substrate at low temperature, 550$^{\circ}C$, by the reaction of B$_2$H$\sub$6/ with PH$_3$ using CVD. N$_2$ was employed as carrier gas. The deposition rate was 1000${\AA}$/min and the refractive index of film was 2.6. The data of XRD show that the film has the preferred orientation of (1 0 1). The VIS spectrophotometer's data proved that the films are transparent in the visible range. Also, we performed AFM, FT-IR measurement. To investigate the annealing effect, the samples were annealed for 1hour, 3hours at 550$^{\circ}C$ and tested.

• Journal of Industrial Technology
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• v.36
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• pp.57-63
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• 2016

In this study characteristics of debris flow landslide were investigated on the focus of debris flow disaster occurred by heavy rainfall in 2013 at Goeun-ri around Kaeryoung Mt. in Chuncheon-si. Appropriate method for estimating scale of debris flow was investigated by comparing those values from soil loss by Universal Soil Loss Equation, debris flow yield rate obtained by field survey of investigating debris flow path from initiation and erosion to deposition and other methods. As results of this study, it might be an opportunity of contributing to construct the data base for determining the size of erosion control facilities in future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.27-30
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• 2002

Photoconductor for direct detection flat-panel imager present a great materials challenge, since their requirements include high X -ray absorption, ionization and charge collection, low leakage current and large area deposition. Selenium is practical material. But it needs high thickness and high voltage in selenium for high ionization rate. We report comparative studies of detector sensitivity. One is an a-Se with $70{\mu}m$ thickness on glass. The other has hybrid layer of depositting ZnS phosphor with $100{\mu}m$ on a-Se. The leakage current of hybrid is similar to it of a-Se, but photocurrent is lager than a-Se. Both of them have high spatial resolution, but hybrid has higher sensitivity than a-Se at comparable bias voltage.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.261-264
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• 1991

Titanium carbide(TiC) films were deposited on stainless-steel sheets using HCD(Hollow Cathode Discharge) reactive ion plating. Acetylene gas was used as the reactant gas. The characteristics of TiC films were examined by X-Ray diffraction, $\alpha$-step, ESCA(Electron Spectroscopy for Chemical Analysis), and, AES(Auger Electron Spectroscopy). The results were discussed with regard to various deposition conditions(bias voltage, acetylene flow rate, temperature).

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.10
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• pp.505-509
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• 2004

The (Sr/sub 0.9/Ca/sub 0.1/)TiO₃(SCT) thin films are deposited on Pt-coated electrode(Pt/TiN/SiO₂/Si) using RF sputtering method at various substrate temperature. The optimum conditions of RF power and Ar/O₂ ratio were 140[W] and 80/20, respectively. Deposition rate of SCT thin film was about 18.75[Å/min]. The crystallinity of SCT thin films were increased with increase of substrate temperature in the temperature range of 100～500[℃]. The dielectric constant of SCT thin films were increased with the increase of substrate temperature, and changed almost linearly in temperature ranges of -80～+90[℃]. The current-voltage characteristics of SCT thin films showed the increasing leakage current as the substrate temperature increases.

• Journal of Surface Science and Engineering
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• v.34 no.6
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• pp.537-544
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• 2001

In the present study, tin-zinc alloys were coated on a cold-rolled steel sheet with variations of electrolyte concentration, additives quantity and current density employing the Hull cell and circulation cell simulator. With an addition of additives of 2m1/L, tin-zinc deposits containing 10 to 40 percent Zn revealed a good surface appearance with weak acidic electrolytes. The organic additives suppressed the Sn deposition rate and thus increased the zinc contents in tin-zinc coating layers. The zinc contents in the tin-zinc coating layers depended almost linearly on the concentrations of metal ions of tin and zinc. Temperature of the electrolyte affected the composition tin-zinc coating layer. However, the concentration of complexants revealed little effectiveness. The surface morphology of tin-zinc coating showed dense tin and zinc phases with fine equiaxed grains with the high current density.

• Journal of Surface Science and Engineering
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• v.35 no.3
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• pp.121-126
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• 2002

WC/C multilayered films were deposited by arc ion plating and magnetron sputter hybrid system with various $C_2$H$_2$ flow rates and bias voltages. The coatings have been characterized with respect to their chemical composition (Glow Discharge Optical Emission Spectroscopy), hardness(Knoop micro-hardness), residual stress(Laser beam bending) and friction coefficient(Ball on disc type wear test). Deposition rate, microhardness and residual stress of WC/C films were observed to increase with increasing the $C_2$$H_2$ flow rates. The highest hardness and residual stress were measured to be 26.5 GPa and 1.1GPa for, WC/C film deposited at substrate bias of -100V. WC/C multilayered film was obtained very low friction coefficient(~0.1).