• 제목/요약/키워드: Enhancement factor

검색결과 927건 처리시간 0.028초

마이크로 채널 관에서의 응축 열전달 성능에 관한 연구 (A study on condensation heat transfer performance in microchannel tube)

  • 이정근
    • Design & Manufacturing
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    • 제13권2호
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    • pp.22-29
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    • 2019
  • This study conducted a research as to condensation heat transfer by using three types of flat micro multi-channel tubes with different processing of micro-fin and number of channels inside the pipes and different sizes of appearances. In addition, identical studies were conducted by using smoothing circular tubes with 5mm external diameter to study heat transfer coefficient. The condensation heat transfer coefficient showed an increase as the vapor quality and mass flux increased. However, each tube shows little differences compared to 400kg/m2s or identical in case the mass flux are 200kg/m2s and 100kg/m2s. The major reason for these factors is increase-decrease of heat transfer area that the flux type of refrigerant is exposed to the coolant's vapor with the effect of channel aspect ratio or micro-fin. In addition, the heat transfer coefficient was unrelated to the heat flux, and shows a rise as the saturation temperature gets lower, an effect that occurs from enhanced density. The physical factor of heat transfer coefficient increased as the channel's aspect ratio decreased. Additionally, the micro pin at the multi-channel type tube is decided as a disadvantageous factor to condensation heat enhancement factor. That is, due to the effect of aspect ratio or micro-fin, the increase-decrease of heat transfer area that the flux type of a refrigerant is exposed to the vapor is an important factor.

일-가정 갈등 및 일-가정 향상 관련 변인 메타분석: 사회적 지지를 중심으로 (A Meta-analysis of Variables related to Work-family Conflict and Work-family Enhancement: Focused on Social Support)

  • 윤민지;윤수란;공현정
    • 한국심리학회지 : 문화 및 사회문제
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    • 제27권1호
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    • pp.113-138
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    • 2021
  • 본 연구는 일-가정 갈등 및 일-가정 향상과 사회적 지지와의 관계를 파악하기 위해 2000년부터 2020년까지 국내에서 이루어진 연구 총 34편(학술지 논문 14편, 학위논문 20편)에 대해 메타분석을 실시하였다(N=17,530). 일-가정 갈등과 향상은 방향에 따라 일→가정, 가정→일, 구분하지 않음으로, 사회적 지지의 지지자원은 가정, 배우자, 조직, 상사, 동료, 구분하지 않음으로, 지지유형은 정서적, 도구적, 정보적, 평가적 지지로 나누어 하위집단분석을 실시하였다. 분석 결과, 지지자원과 지지유형 모두 일-가정 갈등 및 향상과 유의한 관계를 보였으며, 지지자원에 따라 일→가정에서는 갈등과 향상 모두 상사가, 가정→일에서는 갈등에는 가정이, 향상에는 배우자가 가장 유의하였고, 지지유형은 일-가정 갈등에서 일→가정은 평가적, 정서적 순으로, 가정→일은 평가적 정보적 순으로 유의하였다. 이상의 연구결과를 바탕으로 본 연구의 시사점과 한계를 제시하고 추후 연구를 위한 방향을 제언하였다.

Quantum Dot Based Mode-Locked Diode Lasers and Coherent Buried Heterostructure Photonic Crystal Nano Lasers

  • 김지명
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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    • pp.122-122
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    • 2013
  • In this talk, some optical properties of quantum dot based mode-locked diode lasers and photonic crystal nano lasers will be discussed. Linewidth enhancement factor, chirp and interband injection locking technique of quantum dot mode-locked lasers will be presented. Also various types of photonic crystal buried heterostructure lasers toward coherent nano laser will be covered as well.

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Phenothiazine과 Quinone계 분자간 전하 이동형 색소의 합성 및 광 퇴색 (Syntheses and Photofading of Intermolecular Charge-Transfer Complex Dyes of Phenothiazine and Quinonoid Compounds)

  • 김성훈;이순남;임용진
    • 한국염색가공학회지
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    • 제4권2호
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    • pp.64-68
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    • 1992
  • The charge-transfer(CT) complexes derived from phenothiazine as donor and quinonoid compounds as accepters were evaluated as coloring matter. Light fastness of the intermolecular charge-transfer(CT) complex dyes as well as absorption wavelength is an important factor when the complexes are applied to coloring matters. The photofading mechanism of CT complex dyes of phenothiazine and accepters were examined. The addition of effective radical scavenger, antioxidant and photostabilizer gave a remarkable enhancement of the photostability of CT dyes.

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Applied Video Statistics

  • Beek, W.H.M. Van;Cordes, C.N.;Raman, N.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1584-1587
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    • 2005
  • Although the picture quality of today's displays is very good already, a continuous improvement is desirable as the new larger display sizes increase the visibility of artifacts. A contributing factor for picture quality enhancement through smart video processing and algorithm design is the information gathered from video statistics. Interesting parameters gathered from video statistics are e.g. the image- and display load, the usage of the color gamut, the estimated power consumption and the occurrence of static image parts. Examples of applications that can benefit from video statistics are power calculations, color gamut mapping algorithms, dynamic backlight control for LCD panels and LED backlights for LCD panels.

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Fabrication of Vacuum Tube arrays with a sub-micron dimension using Anodic Aluminum Oxide Nano-Templates

  • Hwang, Sun-Kyu;Lee, Kun-Hong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.867-869
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    • 2003
  • Vacuum tube arrays (VTA) with a submicron dimension were fabricated by using anodic aluminum oxide (AAO) nano-templates. The field emission characteristics of Ni nanowires show a turn-on voltage in the range of 11.0-14.0 V and a field enhancement factor in the range of 560-2790. The distance between the tips of Ni nanowires and the anode was much smaller than that between the tips and the anode of conventional designs.

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LDV측정을 통한 엔진내 텀블감쇄 메카니즘 해석 (Analysis of Tumble Decay Mechanism through LDV Measurement in an Engine)

  • 강건용;이진욱;백제현
    • 대한기계학회논문집
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    • 제18권10호
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    • pp.2773-2778
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    • 1994
  • Tumbling motion is very effective for turbulence enhancement during compression process in the cylinder of 4-valve engines. In this paper the tumble decay mechanism for different intake port configuration were measured using laser Doppler velocimetry. Analysis of the tumble decay mechanism was achieved by means of two non-dimensional parameters, defined as tumble eccentricity and shape factor in tumble velocity profile, in addition to the tumble moment.

Electron Field Emission for a Cylindrical Emitter of Single Carbon Nanotube

  • Lee, Youn-Ju;Kim, Chang-Duk;Lee, Hyeong-Rag
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.764-767
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    • 2007
  • We investigated the field emission of single carbon nanotube including the anode effect by calculating the tunneling probability of an electron. The experimental results from this study were in agreement with our theoretical calculations. The constant enhancement factor was calculated using an approximation of the potential barrier.

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