• Journal of Advanced Marine Engineering and Technology
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• 제28권6호
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• pp.922-930
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• 2004

An experimental investigation was performed to study on the generation of air bubble and air core with swirling flow in a horizontal cicular tube. To determine some characteristics of the flow, 2D PIV technique is employed for velocity measurement in water. The experimental rig is manufactured from an acryl tube. The test tube diameter of 80mm, and a length of 3000mm. The used algorithm is the gray leve cross-correlation method(Kimura et al. 1986). An Ar-ion laser is used and the light from the laser(500mW) passes through a probe to make two-dimensional light sheet. In order to make coded images of the tracer particles on one frame, an AOM(Acoustic-Optical Modulator) is used. The maximum axial velocities showed near the test tube wall at y/D =0.1 and y/D =0.9 along the test tube. The higher Reynolds number increase, the lower axial velocities are showed in the center of the test tube. The air bubbles are generated from Re =10,000 and developed into air core from the recirculating water pump rpm equal 30Hz. The pressure and temperature are measured across the test tube at X/D=3.33.

• 한국진공학회지
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• 제2권4호
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• pp.501-506
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• 1993

The spatial potential distribution of electron cyclotron resonance plasma is measured as a function of tehsubstrate DC bias by Langmuir probe method. It is observed that the substrate DC bias changes the slope of the plasma potential near the subsrate, resulting in changes in flux and energy of the impinging ions across plasma $_strate boundary along themagnetric field. The effect of the substrate DC bias on the low-temperature silicon homoepitaxy (below $560^{\circ}C$) is examine dby in situ reflection high energy electron diffraction (RHEED), cross-section transmission electron microscopy (XTEM),plan-view TEM and high resolution transmision electron microscopy(HRTEM). While the polycrystalline silicon layers are grow withnegative substrate biases, the single crystaline silicon layers are grown with negative substrate biases, the singel crystalline silicon layers are grown with positive substrate biases. As the substrate bias changes form negative to positive values, the growth rate decreases. It is concluded that the control of the ion energy during plasma deposition is very important in silicon epitaxy at low temperatures below $560^{\circ}C$ by UHV-ECRCVD.VD.

• 동의생리병리학회지
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• 제27권6호
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• pp.759-763
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• 2013

This experiment was performed to investigate whether 50% ethanol extracts of the combined-preparation of Longanae Arilus, Chrysanthemi Flos, Zizyphi Fructus and Ginseng Radix alba (CPE) has hypnotic effects and/or enhances pentobarbital-induced sleeping time. Locomotor activity was evaluated using a ambulometer of tilting-type. The sedative-hypnotic effects were evaluated by measuring the sleeping onset time and sleeping time in pentobarbital-treated mice 30 min. after oral administration of CPE and muscimol. The intracellular $Cl^-$ concentration of cerebellar granule cells was estimated using $Cl^-$ sensitive fluorescence probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium (MQAE). CPE (150 mg/kg) decreased the locomotor activity, but CPE itself did not induce sleep. However, CPE reduced sleeping onset and prolonged sleeping time induced by pentobarbital (42 mg/kg). In addition, CPE (2 ${\mu}g/ml$) and pentobarbital (2.5 ${\mu}M$) itself did not affect on the chloride influx in primary cultured cerebellar granule cells, but the combination of CPE and pentobarbital (2.5 ${\mu}M$) increased the chloride influx onto the cells. In conclusion, it is suggested that CPE might augment pentobarbital-induced sleep through the increase of chloride influx.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1176-1179
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• 2003

Low-Pressure inductively coupled RF discharge sources have important industrial applications mainly because they can provide a high-density electrodeless plasma source with low ion energy and low power loss. In an inductive discharge, the RF power is coupled to the plasma by an electromagnetic interaction with the current flowing in a coil. In this paper, the experiments have been focussed on the electric characteristic and carried out using a single Langmuir probe. The internal electric characteristics of inductively coupled Ar RF discharge at 13.56 [MHz] have been measured over a wide range of power at gas pressure ranging from $1{\sim}70$ [mTorr].

• 한국전기전자재료학회논문지
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• 제21권8호
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• pp.727-732
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• 2008

In this work, the etch characteristics of $VO_2$ thin films were investigated using inductively coupled plasma (ICP) of $Cl_2/Ar$ gas mixtures. To analyze the plasma characteristics, a quadrupole mass spectrometer (QMS), an optical emission spectroscopy (OES), and a Langmuir probe measuring system were used. The surface reaction of the $VO_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS). It was found that an increase in Ar fraction in the $Cl_2/Ar$ plasma at fixed gas pressure, input power, and bias power resulted in increasing $VO_2$ etch rate which reached a maximum value of 87.6 nm/min at 70-75 % Ar. It was confirmed that the etch rate of the $VO_2$ films was mainly controlled by the ion flux. On the basis of measuring results, we will discuss possible etching mechanism of $VO_2$ film in the $Cl_2/Ar$ plasma.

• 한국공작기계학회논문집
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• 제10권1호
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• pp.133-140
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• 2001

Recently, to assure the integrity of a structural components such as piping pressure vessels and thinning structure, Lamb wave inspection technique has been used in material evaluation. It is very important to select the optimal Lamb wave mode and to analyze the signal accurately because of its unique dispersion properties grnerating several modes within the speci-men. It this study, the feasibility of material evaluation applications using wavelet analysis of Lamb wave has been veir-fied experimentally. These results show as follows; 1)dispersion characteristic of each mode in dispersion curve is demon-strated that A0 mode propagating material surface is useful mode having the lest energy loss and not sensitive to surface condition. 2) it can be detected even the micro defect ($1\times2mm$) fabricated in ultrasonic probe flaw distance (290mm) to axis direction. 3) the wavelet transform which is called "time-frequency analysis" shows the Lamb wave propagation due to the change of materials characterization can be evaluated at each frequency and experimental group velocity of Lamb wave agrees quite well with that of simulated dispersion curve.ion curve.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.137-140
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• 2004

We treated $O_2$ plasma on ITO thin film using RIE (Reactive Ion Etching) system, and analyzed the ingredient of ITO thin film according to change of processing conditions. The ingredient analysis of ITO thin film was used by EDS (Energy Dispersive Spectroscopy) and XPS (X-ray Photoelectron Spectroscopy) to compare and analyze the ingredient of bulk and surface. We measured electrical resistivity using Four-Point-Probe and calculated sheet resistance, and ITO surface roughness was measured by using AFM (Atomic Force Microscope). Finally, we fabricated OLEDs (Organic Light-Emitting Diodes) device using substrate that was treated optimum ITO surface. The result of the study for electrical and optical properties using I V L System (Flat Panel Display Analysis System), we confirmed that electrical properties (I-V) and optical properties (L-V) were improved.

• 한국대기환경학회지
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• 제31권6호
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• pp.497-507
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• 2015

Real-time and quantitative measurement of the chemical composition in ambient aerosols represents one of the most challenging problems in the field of atmospheric chemistry. In the present study, time resolved application by Aerosol-into-Mist System (AIMS) following by total organic carbon analyzer (TOC) has been developed. The unique aspect of the combination of these two techniques is to provide quantifiable water soluble organic carbon (WSOC) information of particle-phase organic compounds on timescales of minutes. We also demonstrated that the application of the AIMS method is not limited to water-soluble organic carbon but inorganic ion compounds. By correlating the volume concentrations by optical particle sizer (OPS), water soluble organic carbon can be highly related to the secondary organic products. AIMS-TOC method can be potentially applied to probe the formation and evolution mechanism of a variety of SOA behaviors in ambient air.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.848-850
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• 1999

In this study, PZT etching was performed using planar inductively coupled Ar(20)/$Cl_2/BCl_3$ plasma, The etch rate of PZT film was 2450 $\AA/min$ at Ar(20)/$BCl_3$(80) gas mixing ratio and substrate temperature of $80^{\circ}C$. X-ray photoelectron spectroscopy (XPS) analysis for film composition was utilized. The chemical bond of PbO is broken by ion bombardment, and the peak of metal Pb in a Pb 4f peak begins to appear upon etching, decreasing Pb content faster than Zr and Ti. As increase content of additive $BCl_3$, the relative content of oxygen decreases rapidly. We thought that abundant Band BCl radicals made volatile oxy-compound such as $B_{x}O_{y}$ and/or $BClO_x$ bond. To understand etching mechanism, Langmuir probe and optical emission spectroscopy (OES) analysis were utilized for plasma diagnostic.

• 한국표면공학회지
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• 제41권4호
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• pp.134-141
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• 2008

We have developed a numerical model for a remote ICP(inductively coupled plasma) system in 2D and 3D with gas distribution configurations and confirmed it by plasma diagnostics. The ICP source has a Cu tube antenna wound along a quartz tube driven by a variable frequency rf power source($1.9{\sim}3.2$ MHz) for fast tuning without resort to motor driven variable capacitors. We investigated what conditions should be met to make the plasma remotely localized within the quartz tube region without charged particles' diffusing down to a substrate which is 300 mm below the source, using the numerical model. OES(optical emission spectroscopy), Langmuir probe measurements, and thermocouple measurement were used to verify it. To maintain ion current density at the substrate less than 0.1 $mA/cm^2$, two requirements were found to be necessary; higher gas pressure than 100 mTorr and smaller rf power than 1 kW for Ar.