• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.143-144
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• 2014

The demand of diesel engine on the construction equipment has been rapidly increased because of thermal efficiency and power. But some of the construction equipment is imported from other country, since the their demands are not so large as compared with the other construction equipment. The imported construction equipments will be tested for emission with standard measurement mode. This study was conducted to measure emission characteristics of the construction equipment with changed standard measurement experimentally.

• 에너지공학
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• 제6권2호
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• pp.129-136
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• 1997

본 연구는 전력계통의 화력발전소로부터 배출되는 NOx및 SO$_2$같은 대기환경오염물질을 고려한 새로운 경제부하배분법을 제시한다. 제안된 방법은 총배출량 제약, 지역별 배출랑 제약 그리고 이들의 동시제약을 만족하면서 화력발전기의 출력을 계획하는 것에 대해 설명되어진다. 또한, 모든 부하배분의 대체안이며 배출량과 총연료비 사이의 상호상충관계를 나타내는 Trade-Off곡선에 의해 배출량과 총연료비 사이의 감도해석이 이 알고리즘에 적용된다. 한편, 이 제안된 방법은 개별적 환경피해(NOx, SO$_2$등)의 상대적 가중치와 총환경비용의 함수로써 경제부하배분이 이것에 의해 어떻게 변화되는지를 해석한다. 본 연구에서 제안된 방법을 시험계통에 적용하여 그 유용성을 검증하였다.

• Journal of Astronomy and Space Sciences
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• 제33권2호
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• pp.109-117
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• 2016

We explain the results of Yu et al. (2015b) of the novel sharpness angle measurement to a large number of spectra obtained from the Fermi gamma-ray burst monitor. The sharpness angle is compared to the values obtained from various representative emission models: blackbody, single-electron synchrotron, synchrotron emission from a Maxwellian or power-law electron distribution. It is found that more than 91% of the high temporally and spectrally resolved spectra are inconsistent with any kind of optically thin synchrotron emission model alone. It is also found that the limiting case, a single temperature Maxwellian synchrotron function, can only contribute up to 58⁺²³₋₁₈% of the peak flux. These results show that even the sharpest but non-realistic case, the single-electron synchrotron function, cannot explain a large fraction of the observed spectra. Since any combination of physically possible synchrotron spectra added together will always further broaden the spectrum, emission mechanisms other than optically thin synchrotron radiation are likely required in a full explanation of the spectral peaks or breaks of the GRB prompt emission phase.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.863-866
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• 2003

Multi-walled carbon nanotubes (CNTs) were synthesized on glass substrates in the different ramp-up heating ambient of vacuum, He, Ar, and $N_{2}$ by thermal chemical vapor deposition. CNTs with higher crystallinity were developed in the buffer gases with faster growth rates than in vacuum. Field emission characteristics were strongly related to the relative position of CNT emitters to the cathode electrodes. The areal-spread emission and instability were overcome by locating the emitters far away from the edges of cathode electrodes. The electrical conditioning of emitters improved their emission uniformity over a large area although it decreased the emission current. This study also discussed the long-term stability of CNT emitters.

• 대한기계학회논문집
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• 제19권2호
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• pp.559-567
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• 1995

The combustion process within a porous inert medium (PIM) burner is numerical studied. A detailed chemical reaction scheme including thermal and prompt NO$_{x}$ reactions is used to predict the formation and destruction of pollutants such as NO$_{x}$ and CO. The reaction paths for NO$_{x}$ formation are divided to quantify the amount of NO$_{x}$ formed through thermal NO$_{x}$ reaction or through prompt NO$_{x}$ reaction. Emission index is calculated to compare the actual mass of NO$_{x}$ or CO produced through the combustion of unit mass of fuel. It is found NO formation in PIM burner is confined in flame zone and formation is suppressed due to heat loss at down-stream of the flame. Higher production of NO through prompt NO reaction path is observed due to the higher concentration of fuel derivative species and its higher diffusion at flame front. For all equivalence ratios, CO emission within PIM burner is lower than that from the one-dimensional freely-propagating flame. PIM burner flame has better NO$_{x}$ emission index from .psi. = 0.75 to .psi. = 1.1. to .psi. = 1.1.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2333-2337
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• 2012

We report the synthesis and thermal annealing of Si-core/ZnO-shell nanorods using a two-step process comprising the metal-assisted electroless etching of Si and the sputter deposition of ZnO. Transmission electron microscopy and X-ray diffraction analysis showed that the cores of the annealed core-shell nanorods were single crystal diamond cubic-type Si, whereas the shells of the annealed core-shell nanorods were single crystal wurtzite-type ZnO. The PL spectra of Si nanorods consisted of a broad red emission band and a weaker blue emission band. The major emission band of Si nanorods was shifted from 700 nm (in the red region) to 440 nm (in the violet region) by ZnO coating. The violet emission of the core-shell nanorods was enhanced in intensity considerably by annealing in an oxidizing atmosphere. The origin of the PL enhancement by annealing is also discussed.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5430-5437
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• 2011

본 연구의 목적은 친환경 무공해 승용 차량에 적용되는 전동식 냉방시스템의 성능특성을 실차에서 확인하는 것이다. 이를 위하여 인버터로 구동되는 전동식 스크롤 압축기를 적용한 전동식 냉방시스템을 설계 및 제작하여 수소 연료전지 자동차에 설치하여 다양한 주행도로 조건에서 실험을 진행하였다. 주행조건의 변화는 시험차량에 장착된 전동식 냉방시스템의 성능에 영향을 주었으며, 고속 및 일반도로 주행조건에서 냉방시스템의 성능이 정지조건에서 냉방시스템의 성능보다 우수하게 나타났다. 또한, 외기온도가 $20.0^{\circ}C$에서 $30.0^{\circ}C$로 증가함에 따라 고내 온도는 평균 $5.2^{\circ}C$ 더 적게 감소하였다.

• 한국진공학회지
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• 제17권2호
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• pp.90-95
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• 2008

본 연구에서는 열 및 불산을 이용한 후처리 공정이 레지스트층을 이용하여 제작된 탄소나노튜브의 전자 방출 특성에 미치는 영향에 대하여 연구하였다. 전자 방출 전류는 초기에 $8V/{\mu}m$의 전계에서 $4.2{\mu}A/cm^2$의 전류에서 열 및 불산 처리 시 각각 $7.5mA/cm^2$ 및 $79mA/cm^2$로 향상되었다. 하지만 열 및 불산 처리를 동시에 실시한 경우 전류 밀도는 $426mA/cm^2$ 및 $656mA/cm^2$로 향상된 전자 방출 특성을 얻을 수 있었다. 전자 방출 특성은 처리 순서에 따라 증가하는 양이 다르게 나타났으며, 가장 우수한 전자 방출 특성은 열 처리를 먼저 시행 후, 불산 처리를 하는 공정에서 나타났다. 이는 열 처리에 의한 탄소나노튜브의 결정성의 증가와 이후 불산 처리에 의한 불소 결합의 증가에 기인함을 알 수 있었다. 강한 불소 결합은 탄소나노튜브 에미터의 전자 방출 특성의 향상에 크게 기여를 하였다.

• 대한기계학회논문집A
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• 제25권8호
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• pp.1189-1196
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• 2001

The objective of this paper is to investigate the applicability of acoustic emission(AE) technique to monitor the progress of the thermal shock damage on alumina ceramic. For this purpose, alumina ceramic specimen was heated in the furnace and then was quenched in the water tank. When the specimen was quenched in the water tank, complex AE signals due to the initiation of micro-cracks and boiling effect were generated by the progress of thermal shock damage. These mixed AE signals have to be classified for monitoring the degree of the thermal shock damage of alumina ceramics. In this paper, the mixed AE signals generated from both the boiling effect and the crack initiation under thermal shock test was analyzed. The characteristics of AE signals were also discussed by considering the variation of bending strength and Yongs modulus of specimens.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.494-494
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• 2013

Atmospheric pressure non-thermal plasma of the needle-typed interaction with aqueous solutions has received increasing attention for their biomedical applications [1]. In this context, surface discharges at bio-solutions were investigated experimentally. We have generated the non-thermal plasma jet bombarding the bio-solution surface by using an Ar gas flow and investigated the emission lines by OES (optical emission spectroscopy) [2]. Moreover, The non-thermal plasma interaction with bio-solutions has received increasing attention for their biomedical applications. So we researched, the OH radical density of various biological solutions in the surface by non-thermal plasma were investigated by Ar gases. The OH radical density of DI water; deionized water, DMEM Dulbecco's modified eagle medium, and PBS; 1x phosphate buffered saline by non-thermal plasma jet. It is noted that the OH radical density of DI water and DMEM are measured to be about $4.33{\times}1016cm-3$ and $2.18{\times}1016cm-3$, respectively, under Ar gas flow 250 sccm (standard cubic centimeter per minute) in this experiment. The OH radical density of buffer solution such as PBS has also been investigated and measured to be value of about $2.18{\times}1016cm-3$ by the ultraviolet optical absorption spectroscopy.