• 제목/요약/키워드: Cloud Chamber

검색결과 13건 처리시간 0.022초

과학관에서 안개상자를 활용한 원자력 체험교육 및 학교밖 교육에 관한 연구 (a Study on the Hands-on Education and the Out-of-School Education of the Nuclear Energy Using the Cloud Chamber in the Science Museum)

  • 오규진;홍대길
    • 한국과학예술포럼
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    • 제6권
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    • pp.67-78
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    • 2010
  • 본 연구의 목적은 원자력 에너지와 방사선에 대한 청소년들의 이해를 돕기 위해 과학관에서 안개상자를 활용하는 교육 방법과 그 교육적 효과를 조사하는 데 있다. 본 연구에서는 안개상자의 역사와 과학관 전시물로서의 가치는 물론 안개상자를 활용한 원자력 체험 교육 및 학교 밖 교육 등을 조사하였다. 또한 과학관에서 안개상자를 활용한 원자력 교육 시 참가자들의 교육 만족도를 조사했다.

Growth and Decay of Alpha Tracks in a Large Scale Cloud Chamber after Injection of Radon

  • Wada, Shinichi;Kobayashi, Tsuneo;Katayama, Yoshiro;Iwami, Toshiaki;Kato, Tsuguhisa;Cameron, John R.
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.275-278
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    • 2002
  • The recognition of the natural background radiation is important not only for radiological education but also for the promotion of people's scientific view about radiation. We made a "room" on the web showing natural background radiation as part of a VRM (Virtual Radiation Museum). The "room" shows the video images of the tracks of charged particles from natural background radiation, alpha and beta ray track from known sources using a Large Scale Diffusion Cloud Chamber. The purpose of this study is to make clear the origin of a kind of track (named A-track) which is thick and easy to recognize with the length less than several cm in the cloud chamber, and to make numerical explanation of its counting rate. The study was carried out using a Large Scale Diffusion Cloud Chamber (Phywe, Germany) installed in the Niigata Science Museum. The Model RNC (Pylon Electronics, Canada) was used as Rn-222 source. Ra-226 activity in RNC was 111.6 Bq calibrated with NIST protocol. Rn-222 gas was injected into the cloud chamber. Continuous video recording with use of Digital Handycam (SONY, Japan) was carried out for 360 min. after injection of Rn-222 gas. The number of alpha-ray track (alpha track) in the video images was analyzed. The growth and decay curve of the total activity of Rn-222 and its alpha emitting progeny were calculated and compared with the count of the alpha tracks. As a result the alpha tracks formed by Rn-222 injection resemble A-Tracks. The relationship between A-track in the cloud chamber and atmospheric Rn is discussed.

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Preliminary Study on the Cloud Condensation Nuclei (CCN) Activation of Soot Particles by a Laboratory-scale Model Experiments

  • Ma, Chang-Jin;Kim, Ki-Hyun
    • Asian Journal of Atmospheric Environment
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    • 제8권4호
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    • pp.175-183
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    • 2014
  • To visually and chemically verify the rainout of soot particles, a model experiment was carried out with the cylindrical chamber (0.2 m (D) and 4 m (H)) installing a cloud drop generator, a hydrotherometer, a particle counter, a drop collector, a diffusing drier, and an artificial soot particle distributer. The processes of the model experiment were as follows; generating artificial cloud droplets (major drop size : $12-14{\mu}m$) until supersaturation reach at 0.52%-nebulizing of soot particles (JIS Z 8901) with an average size of $0.5{\mu}m$-counting cloud condensation nuclei (CCN) particles and droplets by OPC and the fixation method (Ma et al., 2011; Carter and Hasegawa, 1975), respectively - collecting of individual cloud drops - observation of individual cloud drops by SEM - chemical identifying of residual particle in each individual droplet by SEM-EDX. After 10 minutes of the completion of soot particle inject, the number concentrations of PM of all sizes (> $0.3{\mu}m$) dramatically decreased. The time required to return to the initial conditions, i.e., the time needed to CCN activation for the fed soot particles was about 40 minutes for the PM sized from $0.3-2.0{\mu}m$. The EDX spectra of residual particles left at the center of individual droplet after evaporation suggest that the soot particles seeded into our experimental chamber obviously acted as CCN. The coexistence of soot and mineral particle in single droplet was probably due to the coalescence of droplets (i.e., two droplets embodying different particles (in here, soot and background mineral particles) were coalesced) or the particle capture by a droplet in our CCN chamber.

펠티에 소자를 이용한 안개상자 개발 (Development of Cloud Chamber by Using Peltier Device)

  • 우종관;권진영;박상태
    • Journal of Radiation Protection and Research
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    • 제36권3호
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    • pp.134-139
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    • 2011
  • 본 연구에서는 핵물리학 실험에 활용할 목적으로 기존의 안개상자 실험 장치를 개선하여 펠티에 소자를 이용한 새로운 안개상자 실험 장치를 개발하였다. 개발된 안개상자 실험 장치와 캠코더를 활용한 실험을 통해 우주선 비적을 관찰하고 측정된 자료를 비교 분석하였다. 그 결과 다음과 같은 결론을 얻었다. 첫째, 기존의 안개상자 실험 장치는 우주선 비적이 발생되는 빈도가 낮고 따라서 발생된 우주선 비적을 육안으로 관찰하기가 매우 어려웠다. 그러나 본 연구에서 새로 개발한 안개상자 실험 장치는 우주선 비적이 발생되는 빈도가 높고, 실험에 캠코더를 함께 활용하면 발생된 우주선 비적을 편리하고 뚜렷하게 관찰할 수 있었다. 둘째, 본 연구에서 개발한 안개상자 실험 장치를 이용한 실험에서 이소프로판올 $1.04{\times}10^{-5}$ $ml{\cdot}mm^{-3}$ 이상을 사용하고, 안개상자내의 냉각플레이트 상부 1 mm 지점의 온도가 5$^{\circ}C$ 이하가될 때 우주선 비적이 잘 발생되는 최적조건임을 확인하였다. 셋째, 본 연구에서 개발한 안개상자 실험 장치에서 안개상자내의 냉각플레이트의 온도를 전류의 세기에 의해 자동으로 제어할 수 있는 시스템이 개발된다면 더 정확하고 개선된 안개상자 실험 장치를 만들 수 있을 것이며, 그 결과 핵물리학 실험 또는 방사선 종사자 교육에서 개발된 안개상자 실험장치가 쉽게 활용될 수 있을 것으로 사료된다.

Point Cloud Measurement Using Improved Variance Focus Measure Operator

  • Yeni Li;Liang Hou;Yun Chen;Shaoqi Huang
    • Current Optics and Photonics
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    • 제8권2호
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    • pp.170-182
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    • 2024
  • The dimensional accuracy and consistency of a dual oil circuit centrifugal fuel nozzle are important for fuel distribution and combustion efficiency in an engine combustion chamber. A point cloud measurement method was proposed to solve the geometric accuracy detection problem for the fuel nozzle. An improved variance focus measure operator was used to extract the depth point cloud. Compared with other traditional sharpness evaluation functions, the improved operator can generate the best evaluation curve, and has the least noise and the shortest calculation time. The experimental results of point cloud slicing measurement show that the best window size is 24 × 24 pixels. In the height measurement experiment of the standard sample block, the relative error is 2.32%, and in the fuel nozzle cone angle measurement experiment, the relative error is 2.46%, which can meet the high precision requirements of a dual oil circuit centrifugal fuel nozzle.

우주기원의 고에너지 입자가 기후에 미치는 영향: 연구 현황과 정책적 시사점 (Climate Influences of Galactic Cosmic Rays (GCR): Review and Implications for Research Policy)

  • 김지영;장근일
    • 대기
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    • 제27권4호
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    • pp.499-509
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    • 2017
  • Possible links among cosmic ray, cloud, and climate have scientific uncertainties. The reputed topics have been highly controversial during several decades. A link between the atmospheric ionization by galactic cosmic rays (GCR), which is modulated by solar activities, and global cloud cover was firstly proposed in 1997. Some researchers suggested that the GCR can stimulate the formation of cloud condensation nuclei (CCN) in the atmosphere, and then the higher CCN concentrations may lead to an increase of cloud cover, resulting in a cooling of the Earth's climate, and vise versa. The CLOUD (Cosmic leaving outdoor droplets) experiment was designed to study the effect of GCR on the formation of atmospheric aerosols and clouds under precisely controlled laboratory conditions. A state-of-the-art chamber experiment has greatly advanced our scientific understanding of the aerosol formation in early stage and its nucleation processes if the GCR effect is considered or not. Many studies on the climate-GCR (or space weather) connection including the CLOUD experiment have been carried out during the several decades. Although it may not be easy to clarify the physical connection, the recent scientific approaches such as the laboratory experiments or modeling studies give some implications that the research definitively contributed to reduce the scientific uncertainties of natural and anthropogenic aerosol radiative forcing as well as to better understand the formation processes of fine particulate matters as an important parameter of air quality forecast.

스모그 챔버를 이용한 이차 초미세유기먼지의 최근 연구 동향 (Review of Recent Smog Chamber Studies for Secondary Organic Aerosol)

  • 임용빈;이승복;김화진;김진영;배귀남
    • 한국대기환경학회지
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    • 제32권2호
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    • pp.131-157
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    • 2016
  • A smog chamber has been an effective tool to study air quality, particularly secondary organic aerosol (SOA), which is typically formed by atmospheric oxidation of volatile organic compounds (VOCs). In controlled environments, smog chamber studies have validated atmospheric oxidation by identifying, quantifying and monitoring products with state-of-art instruments (e.g., aerosol mass spectrometer, scanning mobility particle sizer) and provided chemical insights of SOA formation by elucidating reaction mechanisms. This paper reviews types of smog chambers and the current state of smog chamber studies that have accomplished to find pathways of SOA formation, focusing on gas-particle partitioning of semivolatile products of VOC oxidation, heterogeneous reactions on aerosol surface, and aqueous chemistry in aerosol waters (e.g., cloud/fog droplets and wet aerosols). For future chamber studies, then, this paper discusses potential formation pathways of fine particles that East Asia countries (e.g., Korea and China) currently suffer from due to massive formation that gives rise to fatal health problems.

초고압 복합소호 차단부의 열가스 거동 예측 (Prediction of Hot Gas Behavior in High Voltage Self-blast Circuit Breaker)

  • 김진범;여창호;서경보;권기영;이학성
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2494-2499
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    • 2007
  • Self-blast circuit breakers utilize the energy dissipated by the arc itself to create the required conditions for arc quenching during the current zero. The high-current simulation provides information about the mixing process of the hot PTFE cloud with $SF_6$ gas which is difficult to access for measurement. But it is also hard to simulate flow phenomenon because the flow in interrupter with high current, $SF_6$-PTFE mixture vapor and complex physical behavior including radiation, calculation of electric field. Using a commercial computational fluid dynamics(CFD) package, the conservation equation for the gas and temperature, velocity and electric fields within breaker can be solved. Results show good agreement between the predicted and measured pressure rise in the thermal chamber.

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MAGNETISM OF NANOPHASE IRON PARTICLES LASER EVAPORATED IN A CONTROLLED OXYGEN ATMOSPHERE

  • Turkki, T.;Jonsson, B.J.;Strom, V.;Medelius, H.;El-Shall, M.S.;Rao, K.V.
    • 한국자기학회지
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    • 제5권5호
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    • pp.745-748
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    • 1995
  • Magnetic nanoparticles of iron and iron oxide have been prepared in a modified upward thermal diffusion cloud chamber using pulsed laser evaporation. SEM/TEM studies of these particles reveal a size distribution with a mean diameter of about $60\;{\AA}$. FTIR spectrum measurements are used to investigate the difference in oxidation level between nanoparticles prepared at different partial oxygen pressures. The complex magnetic behaviour of these particles was studied using DC- and AC-susceptibility measurements. All samples exhibit superparamagnetism with blocking temperatures ranging from 50 K to above room temperature. The coercivity fields as well as the dependence of the blocking temperature on measuring frequency have been studied. magnetic anisotropy constants are found to be one order of magnitude higher than is known for the bulk values. The mean particle size estimated from the magnetic data is found to be in perfect agreement with the TEM observations.

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디젤차량용 통합연료히터의 저온유동성 성능평가 (Low Temperature Fluidity Performance Evaluation of Composited Package Fuel Heater for Diesel Cars)

  • 이정화;박형원;이웅수;이영재;이보희;윤달환
    • 전기전자학회논문지
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    • 제18권1호
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    • pp.152-158
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    • 2014
  • 본 연구에서는 저온유동성 성능검사 시스템 구현을 통해 디젤 차량용 통합형 연료히터의 성능을 평가한다. 저온 유동성 시험장치에서 $+20{\sim}-30^{\circ}C$ 온도범위에 따라 분리형과 통합형 연료히터 성능을 비교하고, 필터 전후에 따라 유압과 시동시간, 히터의 소모전력을 측정한다. 이때 다양한 종류의 필터면적을 사용함으로써 통합형 연료히터와 분리형을 비교한 결과 시동 시간이 23% 향상되었고, 저온시동성능은 19% 정도 향상된다.