• Journal of Industrial Technology
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• v.21 no.B
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• pp.149-153
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• 2001

A study on the particle growth in $TEOS/O_2$ plasma was performed, and particle size and its distribution was measured by the electrical aerosol analyzer (EAA), light scattering particle size analyzer and the particle size was also determined by SEM. The effects of process variables such as total gas flow rate, reactor pressure, supplied power and initial reactant concentration on the particle growth were investigated. From the EAA results, the particle size distribution is divided into three groups of the cluster size and the small and large size particles. The particle size distribution measured by the light scattering particle size analyzer becomes bimodal, because the cluster size particles smaller than 20 nm in diameter cannot be detected by the light scattering particle size analyzer. The size of particles measured by the light scattering particle size analyzer is in good agreements with those by the SEM. Also we could understand that the particle formation is very sensitive to the changes of reactor pressure and reactant concentration. As the total gas flow rate increases, the particle size decreases because of the shorter residence time. As the reactor pressure, or the reactant concentration increases, the particle concentration increases and the particles grow more quickly by the faster coagulation between particles.

• BMB Reports
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• v.29 no.6
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• pp.535-539
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• 1996

The activation of phospholipase D (PLD) catalyzes hydrolysis of phosphatidylcholine (PC) to phosphatidic acid (PA) and choline in plants as well as animals. To determine the presence of PLD in oat cells, we prepared inside-out plasma membrane and cytosolic fractions from oat tissues. PLD activities in both cytosol and plasma membrane were detected by ion chromatography method. The activity of PLD in plasma membrane was dependent upon $Ca^{2+}$ concentration and was heat stable. To investigate whether G-protein couples to PLD, the effects of $GTP{\gamma}S$ and $GDP{\beta}S$ on the PLD activity were measured. PLD activity was dramatically increased 300~400% in the presence of 50 ${\mu}M$ $GTP{\gamma}S$ but not in the presence of 50 ${\mu}M$ $GDP{\beta}S$. These results indicate that G-protein may be involved in regulation of PLD activity. To identify whether PLD is regulated by red light receptor, phytochrome, we irradiated red, far-red, or red/far-red/red light on oat protoplasts. PLD activity has increased 5-fold and 3-fold by treatment with red light and red/far-red/red light, respectively. In contrast, irradiation with far-red light had little or no effect on PLD activity. These results suggest that phytochrome regulates PLD activity through activation of G-protein in oat cells.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.172-180
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• 2007

A new diagnostics of plasma electron temperature and plasma density is introduced with the observation of the light emission along the tube of external electrode fluorescent lamps. With two different methods operating an external electrode fluorescent lamp of outer diameter 4.0 mm and length 860 mm for the back-light source of 37-inch LCD-TVs, the lighting modes and the plasma properties are investigated. In the center balance operation, the light-emission propagates simultaneously from both sides of the high voltage electrodes to the center of the lamp, while in conventional operation the light-emission propagates from the one end of a high voltage to the other ground electrode. In the operation value of luminance $10,000{\sim}15,000cd/m^2$, the electron plasma thermal energy $(kT_e)$ is about $1.3{\sim}2.7eV$ with the electron density $(n_e)$ is about $(1.6{\sim}3.6){\times}10^{16}m^{-3}$.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.623-631
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• 2007

Effect of Soft-start curing on the contraction stress of composite resin restoration polymerized with LED and plasma curing unit The purpose of this study was to evaluate the influence of soft-start light curing on contraction stress and hardness of composite resin. Composite resin (Filtek $Z-250^{TM}$, 3M ESPE, USA) was cured using the one-step continuous curing method with three difference light sources ; conventional halogen light ($XL3000^{TM}$, 3M ESPE, USA) cure for 40 seconds at $400 mw/cm^2$, LED light (Elipar Freelight $2^{TM}$, 3M-ESPE, USA) cure for 20 seconds at $800\;mW/cm^2$ a and plasma arc light ($Flipo^{TM}$, LOKKI, France) cure for 12 seconds at $1300 mW/cm^2$. For the soft-start curing method ; LED light (Elipar Freelight $2^{TM}$, 3M-ESPE, USA) cure exponential increase with 5 seconds followed by 17 seconds at $800\;mW/cm^2$ and plasma arc light ($Flipo^{TM}$, LOKKI, France) cure 2 seconds light exposure at $650\;mW/cm^2$ followed by 11 seconds at $1300\;mW/cm^2$. The strain guage method was used for determination of polymerization contraction. Measurements were recorded at each 2 second for the total of 800 seconds including the periods of light application. Obtained data were analyzed statically using Repeated measures ANOVA, One way ANOVA, and Tukey test. The results of present study can be summarized as follows: 1. Composite resin restoration showed transient expansion just after irradiation of curing light. Contraction stress was increased rapidly at the early phase of polymerization and reduced slowly as time elapsed (P<0.05). 2. Contraction stress was not revealed significant difference between Halogen curing light groups and LED and Plasma Light curing with soft-start group (P>0.05). 3. LED and Plasma Light curing with soft-start showed lower contraction stress than the one-step continuous light curing (P<0.05).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1110-1115
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• 2009

We studied on the design of electrical parameters for ICP(Inductively Coupled Plasma) light sources which can be effective to improve the electrical power efficiency of it. These parameters were derivated from Barkhausen theory about the oscillating condition of a ballaster. The relationships of $f-I_p$ and f-n were calculated theoretically and then these relationships were compared with the measured results about $I_p$ and power depending to a discharge length(l) of ICP light source. Finally, we can see that a specific range of induced current depending to a discharge length would be necessary to minimize the change of magnetization inductance and driving frequency at driving.

• Journal of Information Display
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• v.2 no.4
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• pp.46-51
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• 2001

Using ray-optics code incorporated with three-dimensional PDP cell simulation, we have analysed the energy flow in the PDP cell from the electric power input to the visible light output. Also, the visible light output profile and viewing angle distribution were obtained. We applied our code to the analysis of the barrier rib height effect on the visible light luminance and efficiency of the sustaining discharge. Although cells with higher barrier rib generate more VUV photons, less ratio of visible photons are emitted toward front panel due to the shadow effect. Thus, there exists optimal barrier rib height giving the highest visible luminance and efficiency. This kind of code can be a powerful tool in designing cell geometry.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.293-295
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• 2004

PLS(Plasma Light System) is one of the electrodeless lamp discharged by micro wave. In this new lamp has high efficacy and CRI(Color Rendering Index). It is mainly composed of microwave part and optical part. Microwave parts consist of magnetron, wave-guide and cavity-mesh, while optical parts consist of bulb, mirror and reflector. In this paper, we studied experimentally the heat-resistance and temperature distribution characteristics of bulb in PLS.

• Proceedings of the Korean Vacuum Society Conference
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• 2008.08a
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• pp.295-295
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• 2008

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1489-1490
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• 2011

The $O_2$ plasma treatment is used as improvement of ITO roughness glass for organic light-emitting diodes and organic photovoltaic cells. This study examined the effect of the electrical properties of OLED according to variation of $O_2$ plasma power. In experiment, we found that the electrical characteristics of device are excellent when the power of $O_2$ plasma is 250 W. And when the power of $O_2$ plasma increases over 250 W, the electrical properties were getting worse. $O_2$ plasma treatment not only prevents the diffusion of indium, a metal constituent, to an organic layer but also plays a significant role as improvement of ITO roughness. By considering organic light-emitting diodes treating $O_2$ plasma, it could contribute to the improvement of the efficiency of the device.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.453-457
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• 2008

We studied on the dependency of parameters which those were used to design a ballast of ICP light source. These parameters were derived from Barkhausen criterion equation about the oscillating condition of ballast. Comparing with a change of turns, we can suggest that a change of l is suitable to control a $I_p$ of an ICP light source. According to the Z-l equation, we can find an optimum rating power of ICP light sources corresponding to l.