• 제목/요약/키워드: Radiation pressure

검색결과 684건 처리시간 0.021초

Evaluation of Thermal Comfort on Protective Clothing Worn in an Radiation Power Plant

  • Kim, Eun-Joo;Han, Myung-Sook;Lee, Won-Ja
    • The International Journal of Costume Culture
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    • 제3권1호
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    • pp.30-40
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    • 2000
  • The purpose of this research was to device thermal comfort model for radiation power plant workers in protective clothing. Three fabrics commonly used in protective workwear were made into coveralls of identical design and were evaluated by adult healthy males in four simulated work environment. It was investigated between the physiological response and subjects comfort according to environmental variance and clothing types. The of simulated work enviro mensent was controlled under four different humidity and temperature of each type. (Temperature 20±1℃, RH 40∼70%±5%, Temperature 30±1℃, RH 40∼70%±5%) An index of physiological response was connected with the thermal comfort designed. Mean skin temperature, skim temperature, Axillasy temperature ear canal temperature, clothing climate, total sweat, blood pressure, and R-R interval were be evaluated. Skin temperature difference ocurring during exercise and rest were significant only with respect to time and regions of the body, This despite physical differences in the three coveralls, particulary mass statistically experiment. Also, an index of subject wearing sensation was designed for thermal comfort after investigation determined the kind of clothes and the type of environment. As a result of this research, two types of multiple regressions was deviced to estimate thermal comfort of the protective clothing.

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KCCH-50 MeV 싸이클로트론의 진공계통에 관한 연구 (Study on the Vacuum System of the KCCH-50MeV Cyclotron)

  • 박주식;채종서;류성렬
    • Journal of Radiation Protection and Research
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    • 제11권2호
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    • pp.146-151
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    • 1986
  • 본 논문에서는 원자력병원에 설치된 50MeV-proton싸이클로트론의 진공계통에 관한 일반적인 특성과 측정된 진공결과를 기술하고 있다. 진공장치는 5개의 그룹으로 구성되어 있으며, 동작순서는 EPROM-PC장치에 의해 자동제어된다. 정상가동중의 도달 진공도는 각각 $5{\times}10^{-6}mbar(I,\;II),\;2{\times}10^{-6}mbar(III),\;1.2{\times}10^{-5}mbar(IV),\;1.5{\times}10^{-6}mbar(V)$였으며 이 진공도는 50MeV-proton빔을 가속하기에 충분함을 보여 주었다.

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경기도 안양시 오존농도의 시계열모형 연구 (Analysis of Time Series Models for Ozone Concentration at Anyang City of Gyeonggi-Do in Korea)

  • 이훈자
    • 한국대기환경학회지
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    • 제24권5호
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    • pp.604-612
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    • 2008
  • The ozone concentration is one of the important environmental issue for measurement of the atmospheric condition of the country. This study focuses on applying the Autoregressive Error (ARE) model for analyzing the ozone data at middle part of the Gyeonggi-Do, Anyang monitoring site in Korea. In the ARE model, eight meteorological variables and four pollution variables are used as the explanatory variables. The eight meteorological variables are daily maximum temperature, wind speed, amount of cloud, global radiation, relative humidity, rainfall, dew point temperature, and water vapor pressure. The four air pollution variables are sulfur dioxide $(SO_2)$, nitrogen dioxide $(NO_2)$, carbon monoxide (CO), and particulate matter 10 (PM10). The result shows that ARE models both overall and monthly data are suited for describing the oBone concentration. In the ARE model for overall ozone data, ozone concentration can be explained about 71% to by the PM10, global radiation and wind speed. Also the four types of ARE models for high level of ozone data (over 80 ppb) have been analyzed. In the best ARE model for high level of ozone data, ozone can be explained about 96% by the PM10, daliy maximum temperature, and cloud amount.

음향 홀로그래피를 이용한 방사 음장의 전방예측 방법에 관한 기본 이론 및 신호처리 방법 (The Forward Prediction of Radiation Sound Field Using Acoustic Holography : Basic Theory and Signal Processing Method)

  • 김양한;권휴상
    • 대한기계학회논문집
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    • 제16권9호
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    • pp.1654-1668
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    • 1992
  • 본 연구에서는 경험적으로 측정점 사이의 간격과 구경의 크기를 정하는 방법 에 대하여 살펴보았다.이에 반하여 둘러싸기 오차(wraparound error)는 이산화된 파수 성분 데이타의 처리 과정에서 발생하게 되는데, 이를 줄이기 위한 방법의 일환으 로 본 논문에서는 제로패딩(zero padding)방법을 도입하였다. 또한 둘러싸기 오차 (wraparound error)의 크기를 정량화하여 신뢰할 수 있는 예측결과의 범위를 살펴보았 다.

MODIS 총일차생산성 산출물의 오차요인 분석: 입력기상자료의 영향 (Errors of MODIS product of Gross Primary Production by using Data Assimilation Office Meteorological Data)

  • 강신규;김영일;김영진
    • 한국농림기상학회지
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    • 제7권2호
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    • pp.171-183
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    • 2005
  • In order to monitor the global terrestrial carbon cycle, NASA (National Aeronautics and Space Administration) provides 8-day GPP images by use of satellite remote-sensing reflectance data from MODIS (Moderate Resolution Imaging Spectroradiometer) at l-km nadir spatial resolution since December, 1999. MODIS GPP algorithm adopts DAO (Data Assimilation Office) meteorological data to calculate daily GPP. By evaluating reliability of DAO data with respect to surface weather station data, we examined the effect of errors from DAO data on MODIS GPP estimation in the Korean Peninsula from 2001 to 2003. Our analyses showed that DAO data underestimated daily average temperature, daily minimum temperature, and daily vapor pressure deficity (VPD), but overestimated daily shortwave radiation during the study period. Each meteorological variable resulted in different spatial patterns of error distribution across the Korean Peninsula. In MODIS GPP estimation, DAO data resulted in overestimation of GPP by $25\%$ for all biome types but up to $40\%$ for forest biomes, the major biome type in the Korean Peninsula. MODIS GPP was more sensitive to errors in solar radiation and VPD than in temperatures. Our results indicate that more reliable gridded meteorological data than DAO data are necessary for satisfactory estimation of MODIS GPP in the Korean Peninsula.

승용 디젤엔진 소음 기여인자 추출에 관한 연구(I) (The Study on the Noise Contributing Factors Extraction of the Passenger Diesel Engine(I))

  • 김성훈;권용준;고필규;정연욱;임옥택
    • 한국자동차공학회논문집
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    • 제19권3호
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    • pp.90-98
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    • 2011
  • Noises from diesel engine are the major issues for noise pollution as well as affect customers' purchasing needs to vehicles powered by diesel engine. This study investigates to screen-out main factors that contribute to noises from diesel engine using VGT 2000cc engine developed recently. Changes of fuel temperature, intake temperature and the presence of three way catalyst don't affect the 'Engine Radiation Noise' and the solely three way catalyst influence on the 'Tail Pipe Noise'. Especially, there are no effects of the presence of three way catalyst on torque, which is main subject that should be considered in secondary study.

Co$^{60}\gamma$.gamma.선이 저밀도 폴리에티렌의 각상에 미치는 조사효과 (Radiation Effect to Each Phase of Morphology on a Low Density Polyethylene Irradiated to $C_0^{60}\gamma$. ray)

  • 김봉흡;강도열;김재환
    • 전기의세계
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    • 제23권5호
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    • pp.54-60
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    • 1974
  • Proposals were mode on how to differentiate radiation effects in morphological phases of polyethylene and discussions were developed with the results obtained on a low density polyethylene, SOCAREX, specified by number average molecular weight; overbar Mn=5,400, density; 0.92, and degree of branch; 3.4/100 carbon atom, which was irradiated to Co$^{60}$ .gamma. ray at the dose rate of 0.5 Mrad/hr in ambient temperature under the pressure of 10$^{-5}$ Torr. or 1 atm. respectively. The effect to crystalline phase in possibly deduced from dose dependent variation of relative area between (110) and (200) peaks on X ray diffraction spectrum and that, the effects to amorphous phase can be understood through dose dependent relaxation behaviours of .betha. peak on internal friction characteristics of the specimen. The results obtained thus far indicate that, in crystalline phase, relative crystallinity shows a rather rapid decrease up to 20 Mrad with increasing dose, however, little change of crystallinity can be observed in the region between 20-200 Mrad, and degradation appears to be more predominant than crosslinking up to 60 Mrad. While in amorphous phase the indication also shows that degradation is only predominant up to 20 Mrad. Furthermore several correlations can be seen with amenable explanation between dose dependent behaviours observed in both phases.

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냉장고용 압축기 소음원 규명에 관한 연구 (A Study on the Noise Source Identification of Refrigerator Compressor)

  • 오재응;이창호;이명렬;염성하
    • 한국음향학회지
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    • 제6권1호
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    • pp.48-57
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    • 1987
  • 냉장고에 있어서 소음의 주발생원이 압축기라는 것은 잘 알려져 있는 사실이며 최근 제품의 경량화와 고급화 추세에 따라 그 영향이 더욱 증대되고 있다. 본 연구에서는 이러한 소음을 방지 또는 감소시키기 위하여 냉장고용 압축기에 대한 음압과 음향인텐시티를 측정하여 소음의 방사특성을 파악하였으며 이를 규명하기 위하여 실험적 모우드 해석법을 압축기 구조물에 대하여 적용하였다. 연구결과, 압축기 내부의 모우터 구동에 의해 발생한 진동이 스프링에 의해 효과적으로 절연되지 못하고 있으며 압축기의 shell과 mounting도 소음에 크게 기여하고 있음을 알았다.

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라돈 자핵종의 알파 측정용 여과지 매질의 평가 (Evaluation of Filter Media for Use in Alpha Measurement of Radon Progeny)

  • 서경원
    • Journal of Radiation Protection and Research
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    • 제17권1호
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    • pp.31-41
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    • 1992
  • 라돈 자핵종의 알파 측정용 여과지 매질에 대한 평가를 위한 연구는 물리적 특성조사로 여과지의 정전하 충전과 역학적 강도가 조사된 후, 시료채취 전과 후 여과지에 부가되는 압력차로 여과지의 성질을 시험하였으며, 알파 스팩트럼분석으로 여과지내 부착된 라돈 자핵종의 에너지스펙트럼을 분석하여 성능지수를 계산한 후 여과지의 특성을 비교 평가하였다. 평가의 결과 새로운 여과지 매질은 과거의 표준인 Millipore AA보다 크게 유리한 점은 없었으나, 정전하가 문제되는 곳에서는 Metricel DM-800을 권고하였다. 또한 평가방법은 새로 개발될 여과지들의 물리적 특성과 매질의 수집효율을 고려하여 라돈 자핵종의 알파 측정용 여과지 매질 평가를 위해 유용하게 사용될 수 있을 것이다.

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Scanning Photoelectron Microscopy Study on the Chemical State of Locally Oxidized and Hydrogenized Graphene Layer

  • Km, Wondong;Byun, Iksu;Hwang, Inrok;Park, Bae Ho;Baek, Jaeyun;Shin, Hyun-Joon;Shiu, Hung Wei;Chen, Chia-Hao
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.144.1-144.1
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    • 2013
  • Recently, we have developed the local oxidization and hydrogenization method for graphene layer using atomic force microscope(AFM) tip at room temperature and ambient pressure. With this method we could create locally oxidized or hydrogenized area on the graphene layer with various size from nanometer to micrometer scale, by controlling the amplitude and polarity of the voltage supplied between conducting AFM tip and the graphene layer. We investigated the chemical states of functionalized C atoms in the graphene layer using scanning photoelectron microscopy. By measuring C 1s core level X-ray Photoemission Spectra of the C atoms and suitable fitting process carried on the measured spectra, we could obtain the fraction of oxidization and hydrogenization under various condition, and the evolution of each chemical state during thermal annealing process.

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