• 생명과학회지
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• 제15권5호
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• pp.840-846
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• 2005

본 연구는 식품의 안전성에 대한 관심이 고조되면서 위생적인 식육생산을 위한 방법으로 전자선을 조사하여 이화학적 특성 및 지방산화에 미치는 영향을 조사하고자 실시하였다. 공시재료는 한우암소 지육중 육질등급 1+판정(근내지방도 No.7. 육색 No.4, 성숙도 No.1, 조직감 No.1)을 받은 지육($280\∼300kg$) 6두를 구매하였다. 구매한 원료지육을 1차 수도물로 고압수세하고 2차 $ 50\% $에틸알콜로 소독한 후 발골 정형하여 실험재료로 사용하였다. 모든 처리에서 가열온도가 높아갈수록 포화지방산의 함량이 높아갔다. PBS는 가열온도에 따른 지방산패에서 전자선 비조사구와 조사구 모두 가열온도가 높을수록 높은 지방산 패도를 나타내 었고(P<0.05), OBS 또한 malonsldehyde양이 증가하였다(p<0.05). 가열온도별로는 $ 60^{\circ}C $에 비하여 $ 80^{\circ}C $가 비조사구와 3, 6 kCy 조사구는 약 2배정도의 MA량이 생성되었다(p<0.05). OBS가 PBS보다 많은 양의 malonaldehyde가 생성되었으며, 전자선 조사 수준의 차이에는 수준에 따라 비조사구와 약간의 차이만 나타내었다. 전자선조사수준과 가열온도가 증가함에 따라 콜레스테롤 산화물의 발생량이 증가하였으며, 또한 가열방법 중 PBS가 OBS에 비하여 산화의 정도가 유의적으로 증가하였다(p<0.05).

• 한국표면공학회지
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• 제25권6호
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• pp.287-292
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• 1992

Silicon nitride thin film (SiNx) was deposited onto the 3inch silicon wafer using an electron cyclotron resonance (ECR) plasma apparatus. The thin films which were deposited by changing the SiH4N2 gas flow rate ratio at 1.5mTorr without substrate heating were analyzed through the x-ray photo spectroscopy (XPS) and ellipsometer measurements, etc. Silicon nitride thin films prepared by the electron cyclotron resonance plasma chemical vapor deposition method at low substrate temperature (<10$0^{\circ}C$) exhibited excellent physical and electrical properties. The very uniform and good quality silicon nitride thin films were obtained. The characteristics of electron cyclotron resonance plasma were inferred from the analyzed results of the deposited films.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권5호
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• pp.246-252
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• 2002

Two-dimensional steady state simulations of planar type radio frequency inductively coupled plasma (RFICP) have been performed. The characteristics of RFICP were investigated in terms of power transfer efficiency, equivalent circuit analysis, spatial distribution of plasma density and electron temperature. Plasma density and electron temperature were determined from the equations of ambipolar diffusion and energy conservation. Joule heating, ionization, excitation and elastic collision loss were included as the source terms of the electron energy equation. The electromagnetic field was calculated from the vector potential formulation of ampere's law. The peak electron temperature decreases from about 4eV to 2eV as pressure increases from 5 mTorr to 100 mTorr. The peak density increases with increasing pressure. Electron temperatures at the center of the chamber are almost independent of input power and electron densities linearly increase with power level. The results agree well with theoretical analysis and experimental results. A single turn, edge feeding antenna configuration shows better density uniformity than a four-turn antenna system at relatively low pressure conditions. The thickness of the dielectric window should be minimized to reduce power loss. The equivalent resistance of the system increases with both power and pressure, which reflects the improvement of power transfer efficiency.

• 열처리공학회지
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• 제24권3호
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• pp.140-143
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• 2011

In this work, Ga doped ZnO (GZO) films were prepared by radio frequency (RF) magnetron sputtering without intentional substrate heating on glass substrate and then the effect of the intense electron irradiation on structural and electrical properties and the NOx gas sensitivity were investigated. Although as deposited GZO films showed a diffraction peak for ZnO (002) in the XRD pattern, GZO films that electron irradiated at electron energy of 900 eV showed the higher intense diffraction peaks than that of the as deposited GZO films. The electrical property of the films are also influenced with electron's energy. As deposited GZO films showed the three times higher resistivity than that of the films irradiated at 900 eV In addition, the sensitivity for NOx gas is also increased with electron irradiation energy and the film sensor showed the proportionally increased gas sensitivity with NOx concentration. This approach is promising in gaining improvement in the performance of thin film gas sensors used for the detection of hazard gas phase.

• 한국세라믹학회지
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• 제49권1호
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• pp.124-129
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• 2012

An M-shaped SiC gas igniter was fabricated by a reaction sintering followed by nitrogen doping. The igniter showed both resistivity at room temperature and NTC to PTC transition temperature values that were lower than those of commercial igniters. It was deduced that the doped nitrogen reduces the electrical resistivity at room temperature, while, at high temperature, the doped nitrogen and a trace of $Si_3N_4$ phase work as scattering centers against electron transfer, resulting in a lowered NTC-to-PTC transition point (below $650^{\circ}C$). Such characteristics were correlated to the fast heating speed (as compared to the commercial models) and to the prevention of the high temperature overshooting of the nitrogen-doped SiC igniter.

• Journal of Astronomy and Space Sciences
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• 제37권1호
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• pp.29-34
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• 2020

On 21 August 2017, during 16:49 UT and 20:02 UT period, a total solar eclipse started. The totality shadow occurred over the United States in time between ~17:15 UT and ~18:47 UT. When the solar radiation is blocked by the moon, observations of the ionospheric parameters will be important in the space weather community. Fortunately, during this eclipse, two Swarm satellites (A and C) flied at about 445 km through lunar penumbra at local noon of United States in the upper ionosphere. In this work, we investigate the effect of the solar eclipse on electron density, slant total electron content (STEC) and electron temperature using data from Swarm mission over United States. We use calibrated measurements of plasma density and electron temperature. Our results indicate that: (1) the electron density and STEC have a significant depletion associated with the eclipse; which could be due to dominance of dissociative recombination over photoionization caused by the reduction of ionizing extreme ultraviolet (EUV) radiation during the eclipse time (2) the electron temperature decreases, compared with a reference day, by up to ~150 K; which could be due to the decrease in photoelectron heating from reduced photoionization.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.611-615
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• 2004

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, Electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The electrodeless fluorescent lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, electron temperature and electron density were measured in a radio-frequency inductively coupled plasma using a Langmuir probe method for emission characteristics. Measurement was conducted in an argon discharge for pressure from 10 [mTorr] and input RF power 100 [W] to 150 [W]. As for the electron density, a electron temperature was more distinguished for a emission characteristic. The results of ideal may contribute to systematic understanding of a electrodeless fluorescent lamps of emission characteristics.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2002년도 제23회 학술발표회 초록집
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• pp.198-198
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• 2002

• Corrosion Science and Technology
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• 제17권6호
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• pp.287-291
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• 2018

In this study, corrosion behavior of a SA178-A alloy used in the boiler tube of a district heating system was investigated in different environments where it was exposed to pure water, district heating (DH) water, and filtered district heating (FDH) water. After the corrosion test, the surface morphology was examined for observation of the number of pitting sites and pitting area fraction, using a scanning electron microscope. The DH water and FDH water conditions resulted in a lower corrosion potential and pitting potential, and revealed a significantly higher corrosion rate than the pure water condition. The pitting sites in the DH water (pH 9.6) were approximately eighteen times larger than those in the pure water (pH 9.6). Compared to the DH water, the corrosion potential became more noble in the FDH water condition, where iron ions were reduced through filtration. However, the corrosion rate increased in the FDH water due to an increased concentration of chloride ions, which deteriorated the stability of passive film.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.43-46
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• 1997

The interfacial bond strength and microstructural analysis of pre-heat treated porcelain-fused-metal (PFM) were investigated using a mechanical three-point bending tester and scanning electron microscope(SEM). Four kinds of heat treated samples were prepared as follows; A: heating $1200^{\circ}F\rightarrow1600^{\circ}F$, holding 1min, reheating $\rightarrow1850^{\circ}F$, hold 3min under vacuum, B: heating $1200^{\circ}F\rightarrow1600^{\circ}F$ holding 1min, reheating $\rightarrow1850^{\circ}F$ under vacuum condition, C: heating $1200^{\circ}F\rightarrow1600^{\circ}F$, holding 1min, reheating $\rightarrow1850^{\circ}F$, holding 3min in the air, repeat same heat treatment process under vacuum condition, D: heating $1200^{\circ}F\rightarrow1600^{\circ}F$, holding 1min, reheating $\rightarrow1850^{\circ}F$, holding 1min in the air. The three-point bending test results shows that the interfacial bond strength of specimen B and C were higher than that of A and B. The SEM study reveals that Specimen C shows the highest surface density.