• 한국표면공학회지
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• 제29권3호
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• pp.149-156
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• 1996

Conducting diamond-like carbon films are synthesized using Triode Magnetron Sputtering-Plasma Enhanced Chemical Vapor Deposition(TMS-PECVD), and are examined by four point probe, microhardeness tester, and scanning electron miscroscopy(SEM). As the target bias and Ar/CH$_4$, ratio increase, the electrical resitivity and microhardness of the films are found to decrease, and also, their surface morphologies tend to be rough. While the resistivities of the films are shown to increase in proportion to the increase of the substrate bias, the microhardness of the films is shown to be maximun value(1600kg/$\textrm{mm}^2$) at a certain substrate bias(-70V). We can obtain the conducting diamond-like carbon films with the microhardness of 1600(kg/$\textrm{mm}^2$) and electrical resitivity of 16($\Omega$cm) at the process condition such as target bias -400V, substrate bias -70V, and Ar/$CH_4$ ratio 20.

• 한국표면공학회지
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• 제33권4호
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• pp.229-232
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• 2000

C-axis oriented zinc oxide thin films were deposited on glass substrate by reactive Facing Targets Sputtering (FTS) system. The characteristics of zinc oxide thin films on power, inter targets distance, and substrate temperature were investigated by XRD(x-ray diffractometer), alphastep (Tencor) analyses. The Facing Targets Sputtering system can deposit thin film in plasma-free situation and change the deposition condition in wide range. The excellently c-axis oriented zinc oxide thin films were obtained at sputter pressure 1mTorr, sputtering current 0.4A, substrate temperature $300^{\circ}C$, inter targets distance 100mm. In the conditions, the rocking curve of zinc oxide thin films deposited on ZnO/Glass was $3.9^{\circ}$.

• 한국표면공학회지
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• 제32권3호
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• pp.406-409
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• 1999

Thin films of silver with high reflectance of 95% and above were fabricated successfully on polyester substrate by using e-beam evaporation processes. The optimum process condition was investigated by varying the current values applied while keeping the substrate temperature at room temperature by circulating the cooling water around it during deposition. Thin films of silver deposited with 30 mA as current revealed the highest reflectance of 96.4%, while being illuminated with a light of 700nm wave-length. But their adhesion showed unsatisfactory results. Though the films showed a condensation type in the cross-sectional views, they revealed crystallinity in the planes of (111) and (200) and growth orientation in <100> direction.

• 한국습지학회지
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• 제13권3호
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• pp.613-621
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• 2011

조름나물(Menyanthes trifoliata L.)은 주로 산지습지에 서식하는 우리나라 멸종위기 식물로, 인간에 의한 교란과 기후변화로 서식지가 감소되고 있다. 생물의 서식을 제한하는 요인으로 환경과 종간경쟁이 있으므로 조름나물의 분포가 제한되는 이유를 이해하기 위해서는 서식 환경 뿐아니라 함께 서식하는 다른 종의 영향을 살펴보는 것이 중요하다. 본 연구에서는 서식 기질과 동반종이 조름나물의 서식에 미치는 영향을 살펴보고자 하였다. 서식기질로는 물이끼 매트와 논흙을 두었으며, 각 조건에서의 식생과 조름나물의 생장을 비교하였다. 그 결과, 물이끼 매트에서 조름나물의 상대피도가 높았으며, 조름나물보다 초고가 큰 종은 적었다. 반면, 논흙에서는 많은 종이 조름나물에 비해 높은 초고를 보였다. 조름나물의 최대 피도는 물, 물이끼 매트, 논흙 조건 순으로 낮아졌다. 이를 통해 조름나물은 식물 간의 경쟁에 의해 생육이 제한됨을 확인하였다. 조건 간 조름나물의 초고는 큰 차이가 없어, 조름나물은 위로 성장하여 경쟁력을 키우기 보다는 다른 식물이 잘 살지 못하는 곳으로 지하경을 확장하여 경쟁력을 확보하는 것으로 보인다. 본 연구결과 조름나물의 보존 또는 서식지 조성을 위해서는 조름나물 이외의 식물이 잘 자라지 못하는 조건을 만들어 주어야 함을 제안한다.

• 한국재료학회지
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• 제33권9호
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• pp.372-376
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• 2023

Transparent conductive tungsten (W) doped indium oxide (In₂O₃; IWO) films were deposited at different substrate bias voltage (-V_b) conditions at room temperature on glass substrates by radio frequency (RF) magnetron sputtering and the influence of the substrate bias voltage on the optical and electrical properties was investigated. As the substrate bias voltage increased to -350 V_b, the IWO films showed a lower resistivity of 2.06 × 10^-4 Ωcm. The lowest resistivity observed for the film deposited at -350 V_b could be attributed to its higher mobility, of 31.8 cm²/Vs compared with that (6.2 cm²/Vs) of the films deposited without a substrate bias voltage (0 V_b). The highest visible transmittance of 84.1 % was also observed for the films deposited at the -350 V_b condition. The X-ray diffraction observation indicated the IWO films deposited without substrate bias voltage were amorphous phase without any diffraction peaks, while the films deposited with bias voltage were polycrystalline with a low In₂O₃ (222) diffraction peak and relatively high intensity (431) and (046) diffraction peaks. From the observed visible transmittance and electrical properties, it is concluded that the opto-electrical performance of the polycrystalline IWO film deposited by RF magnetron sputtering can be enhanced with effective substrate bias voltage conditions.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.489-495
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• 2000

When microorganisms such as bacteria and fungi are injected into porous medium such as soils along with appropriate substrate and nutrients, biomass retained in the soil pore. Soil pore size and shape are varied from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after microorganism are inoculated and cultured with synthetic substrates and nutrients. Biomass-soil mixture was evaluated its applicability to the field condition as an alternative liner material in landfill by measuring hydraulic conductivity change after repetitive freeze-thaw cycles.

• 전자공학회논문지D
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• 제35D권8호
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• pp.1-7
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• 1998

This paper reports a dispersion compensation technique to implement tje distortionless transmission line by satisfying the heaviside conditon. Because of the skin depth for aconductor, compensation condition is dependent on the freuqncy variation. For this reason, first, the resistance have been chaacterized in awide range of frequencies, and then found the effective conductivity of the substrate which satisfied the heaviside condition. The phase velocity and the characteristics impedance are prresented nearly constant over a wideband frequency range.

• E2M - 전기 전자와 첨단 소재
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• 제8권3호
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• pp.357-361
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• 1995

An experiment on characteristics of nMOSFET's in the long stress condition with the maximum of the substrate current has been carried out in order to study on the degradation due to the hot-carrier effect. Based on the measured result of the threshold voltage, the damage is mostly due to the hole injection into the oxide. After long stress, it was shown that the drain current increased at low gate voltages and hence decreased at high gate voltages.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1573-1575
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• 2004

An alumina membrane with nano-sized pores was fabricated by anodic oxidation. The shape and structure of the pore on alumina membrane were changed according to the roughness of aluminum surface. The shape and structure of the nano-sized pre were investigated according to purity of aluminum substrate for the anodization process. The aluminum substrates with 99.5% and 99.999% purities were used. The aluminum substrate(99.5%) was anodized after the processes of pressing, mechanical polishing, chemical polishing, and electrochemical polishing. The nano-sized pores with the pore size of 50 - 100nm, the cell size of 20-50nm and the thickness of $10{\mu}m{\sim}45{\mu}m$ were obtained. Even though the electrochemical polishing was used for the aluminum substrate (99.999%), the same characteristics as the aluminum substrate (99.5%) was obtained. The alumina membrane prepared by anodization for 5 min using fixed voltage method shows the pore with irregular shape. The pore shape was changed to regular shape after pore widening process.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권1호
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• pp.1-8
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• 2010

Cometabolic air sparging (CAS) is a new and innovative technology that uses air sparging principles but attempts to optimize in situ contaminant degradation by adding a growth substrate to saturated zone. CAS relies on the degradation of the primary growth substrate and cometabolic substrate transformation in the saturated zone and in the vadose zone for volatilized contaminants. In this study, we have investigated to determine MTBE degradation pattern and microbial activity variation if using propane as a primary substrate at the condition of considering air injection rate and air injection pattern. Laboratory-scale two-dimentional aquifer physical model studies were used and the experimental results were represented that the optimal conditions were as air injection rate of 1,000 mL/min and pulsed air injection pattern (15 min on/off). Over 1,000 mL/min air injection rate and continuous air injection pattern was no affected to increase DO concentration. On the other hand, Injection of propane and propane-utilizing bacteria degraded MTBE partially. And also, injection of propane- and MTBE-utilizing bacteria effectively degraded MTBE and TBA production was observed.