• Journal of Korean Biological Nursing Science
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• 제14권4호
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• pp.275-281
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• 2012

Purpose: This study was performed to evaluate the effect of low-dose lidocaine on fentanyl-induced cough and hemodynamic changes under general anesthesia. This research was a randomized trial design and performed using a double-blind method. Methods: Data collection was performed from October 22, 2008, to May 4, 2009. One hundred and thirty two patients were randomly assigned to control group (Con G) and experimental group (Exp G) using a table of random numbers. Exp G (n=66) were administered 0.5 mg/kg lidocaine and Con G (n=66)) were administered saline. The occurrence of cough and vital sign were recorded within one minute after fentanyl bolus by an anesthesiologist. Collected data were analyzed using Repeated measures ANOVA using SPSS for Windows (Version 17.0). Results: The incidence of cough in Exp G was 13.6%, while Con G was 53%. The incidence cough in Exp G was significantly lower compared to Con G (p<.001). Lidocaine seemed not to suppress mean arterial pressure (p=.145), heart rate (p=.508), and oxygen saturation (p=.161). Conclusion: Intravenous administration of 0.5 mg/kg lidocaine seems to suppress fentanyl-induced cough without affecting mean blood pressure, heart rate and oxygen saturation. Therefore, we recommend intravenous 0.5 mg/kg lidocaine administration to suppress fentanyl-induced cough under general anesthesia.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.208-208
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• 2010

Zinc oxide (ZnO) is a functional material with interesting optical and electrical properties, a wide band gap (more than 3.3 eV), a high transmittance in the visible light region, piezoelectric properties, and a high n-type conductivity. This material has been investigated for use in many applications, such as transparent electrodes, blue light-emitting diodes, and ultra-violet detector. ZnO films grown under low oxygen pressure by thin film deposition methods show low resistivity and large free electron concentration. Therefore, reducing the background carrier concentration in ZnO films is one of the major challenges ahead of realizing high-performance ZnO-based optoelectronic devices. In this study, we deposited ZnO thin films on sapphire substrates by pulsed laser deposition (PLD) with employing an oxygen plasma source to decrease the background free-electron concentration and enhance the crystalline quality. Then, the substrate temperature was varied between 200 'C to 900 'C The vacuum chamber was initially evacuated to a pressure of $10^{-6}$ Torr, and then a pure $O_2$ gas was introduced into the chamber and the pressure during deposition was maintained at $10^{-2}$ Torr. Crystallinity and orientation of ZnO films were investigated by X-ray diffraction (XRD). The film surface was analyzed with atomic force microscope (AFM). And electrical properties were measured at room temperature by Hall measurement.

• 한국자기학회지
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• 제19권3호
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• pp.94-99
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• 2009

Pulsed Laser Deposition 방법으로 합성된 $La_{0.7}Ca_{0.3}MnO_3$ 박막의 물리적 특성을 증착 조건에 따라 조사하였다. 기존에 알려진 바와는 매우 달리 매우 낮은 산소 분압 ($1.0{\times}10^{-5}$, $1.0{\times}10^{-6}Torr$)에서도 큐리 온도가 높은 박막의 합성이 이루어졌으며 이는 박막의 합성 과정에서 쳄버 내부의 산소 분압보다는 플라즈마 plume의 모양과 그 내부 물질들의 운동에너지가 박막의 질을 결정하는 매우 중요한 요소임을 의미한다. 이러한 양질 박막의 합성 증착 조건을 이용하여 $La_{0.7}Ca_{0.3}MnO_3$ 을 Nb가 도핑된 $SrTiO_3$ 기판위에 증착함으로써 p-n 접합을 제작하였으며 이의 전류-전압곡선이 정류 특성을 보였고 그 모양은 자기장에 의해 바뀔 수 있음을 확인하였다.

• 한국연소학회지
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• 제21권4호
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• pp.39-47
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• 2016

The aims of this research were to investigate combustion characteristics of lab-scale pressurized oxy-fuel combustion(POFC) system. In this study, the reactor, 800 mm long, was equipped with co-axial burner. Low calorific value syngas that is composed of mainly CO and $H_2$ was used as fuel whereas pure oxygen was used as an oxidant. Thermal heat input to the reactor varied from 2.6 kW to 6.1 kW. The reactor pressure also increases from atmospheric up to 15 bar. The results show that as the pressure increase, the temperature of reactor decreases on the whole in all cases. A significant temperature drop was observed especially at the bottom section of the reactor that exist flame. In addition, the flame instability increases as the pressure increases. Furthermore $NO_x$ emissions increases from atmospheric up to 2 bar. However beyond 2 bar, $NO_x$ emission reduces as pressure increases. Lastly $NO_2$ ratio in $NO_x$ also increases as pressure increases.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1350-1354
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• 2007

As the importance of low power design is emphasized, power consumption became one of the standards that represent the performance of the system. The purpose of this study is to decide design variable that minimize power consumption for the oxygen concentrator in two bed-one compressor 8 step PSA process that has above 90% purity at 3lpm by using given constants and selected parameters. Setting selected parameters as cycle time and equalization time, optimization for PSA process in the oxygen concentrator is progressed. For this, we need to know the features and basic principals of PSA process and to deduce objective function of performance analysis. Validations for objective function and lots of experiments are needed too. By using the characteristic curve of the compressor and the pressure curve of the process for 1 cycle, objective function was set. After theoretical 2 dimensional optimized paths was obtained. And then, by experiment, theoretical optimized path was verified.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.292-295
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• 2001

The NdBaCuO superconducting samples were prepared by the Zone melting under low oxygen partial pressure. After the zone-melting the oxygenation process of the NdBaCuO samples in a oxygen flow furnace was studied. In order to compare the oxygenation condition the sintering NdBaCuO samples were studied also. In the study it is found that the optimum temperature for the oxygenation is $350^{\circ}C$, and the oxygen flow speed, the sample volume and the surface area of the sample would influence the oxygenation and the oxygen content.

• 한국표면공학회지
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• 제31권2호
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• pp.109-116
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• 1998

Highly transparent conductive pure and fluorine-doped tin oxide(FT0, $SnO_2$ : F) films have been prepared by low pressure metal organic chemical vapor deposition (LP-MOCVD) from various mixtures of tetramethyitin(TMT) with oxygen or oxygen containing ozone. The properties of TO films have been changed with the variation of gases, flow rate, and substrate temperature. The nsing of oxygen containing ozone instead of pure oxygen, reduced substrate temperature by 100-$150^{\circ}C$ while maintaining same thickness. The films prepared by using ozone showed the resistivity in the range from $10^~2$ to $10^{~3}\Omega$cm, and the mobiiity from 10 to $14\textrm{cm}^2$/Vs. Fluorine-doped tin oxide films had properties such as the resistivity about $10^{-4}\Omega$cm, and the mobility from 14 to $19\textrm{cm}^2$/Vs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.292-295
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• 2001

The NdBaCuO superconducting samples were prepared by the Zone melting under low oxygen partial pressure. After the zone-melting the oxygenation process of the NdBaCuO samples in a oxygen flow furnace was studied. In order to compare the oxygenation condition the sintering NdBaCuO samples were studied also. In the study it is found that the optimum temperature for the oxygenation is $350{\circ}C$, and the oxygen flow speed, the sample volume and the surface area of the sample would if1uence the oxygenation and the oxygen content.

• 대한전자공학회논문지
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• 제22권6호
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• pp.7-12
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• 1985

Oxygen-active 금속, 천이금속 및 oxygen-noble 금속, 즉, Al, Ti, Mn, Ni 그리고 Cuㄹ박막의 광투과율을 조사하였다. Slide-glass 위에 $6{\times}10^{-5}$ ~ $2{\times}10^{-4}$ mbr 압력범위와 0.5 ~ $2{\AA}$/sec 의 증착속도 범위에서 두께를 $85{\AA}$내외로 하여 증착하였다. 증착속도와 진공도는 금속박막의 광학적 성질에 큰 영향을 미치며 이는 주로 산소개입에 의한 것임을 알 수 있었다. 특히 광투과율이 매우 낮다고 알려진 산소와의 친화력이 강한 금속, 즉, Al, Ti, Cr 그리고 Ni의 광투과율을 저 진공도나 느린 증착속도에 의한 증착공정으로 상당히 향상시킬 수 있었다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.265-268
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• 2005

Jet A-1과 액체산소를 추진제로 하는 연소압 52.5 bara 추력 30 tonf급 로켓엔진 연소기의 2단 점화시험을 수행하였다. 점화방식으로 TEAL과 액체산소를 사용한 hypergolic 방식을 사용하였다. 산화제 $61\%$, 연료 $67\%$를 공급하여 정상 연소압 대비 $63\%$인 33 abs.bar의 연소압으로 0.25 초 동안 pre-stage 구간을 유지하였다. 2단계의 점화과정을 통해 정상상태에 이르기까지 O/F ratio를 설계조건 보다 낮은 영역에 유지하였다. main-stage로 진입 시 압력피크는 정상 연소압의 $0.6\%$를 보였다.