• 제목/요약/키워드: Depletion effect

검색결과 545건 처리시간 0.027초

저압화학기상증착법을 이용한 ZrC 성장에 잔류시간이 미치는 영향 (Residence Time Effect on the Growth of ZrC by Low Pressure Chemical Vapor Deposition)

  • 박종훈;정충환;김도진;박지연
    • 한국세라믹학회지
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    • 제45권5호
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    • pp.280-284
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    • 2008
  • In order to investigate residence time effect on the growth of ZrC film, the ZrC films grew with various system total pressure (P) and total flow rate (Q) by low pressure chemical vapor deposition because residence time is function of system total pressure and total flow rate. Thermodynamic calculations predict that the decomposition of source gases ($ZrCl_4$ and $CH_4$) would be low as increasing the residence time. Thermodynamic calculations results were proved by investigating deposition rate with various residence time. Deposition rate decreased with residence time of source gas increased. Besides, depletion effect accelerated diminution of deposition rate at high residence time. On the other hands, the deposition rated was increased as decreasing the residence time because fast moving of intermediate gas species decrease the depletion effect. The crystal structure was not changed with residence time. However, the largest size of faceted grain showed up to specific residence time and the size of grain was decreased whether residence time increase or not.

Monte Carlo 방법을 이용한 로듐 및 바나듐 자발 중성자계측기의 연소에 따른 민감도 평가 (Depletion Sensitivity Evaluation of Rhodium and Vanadium Self-Powered Neutron Detector (SPND) using Monte Carlo Method)

  • 차균호;박영우
    • 센서학회지
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    • 제25권4호
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    • pp.264-270
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    • 2016
  • Self-powered neutron detector (SPND) is a sensor to monitor a neutron flux proportional to a reactor power of the nuclear power plants. Since an SPND is usually installed in the reactor core and does not require additional outside power, it generates electrons itself from interaction between neutrons and a neutron-sensitive material called an emitter, such as rhodium and vanadium. This paper presents the simulations of the depletion sensitivity evaluations based on MCNP models of rhodium and vanadium SPNDs and light water reactor fuel assembly. The evaluations include the detail geometries of the detectors and fuel assembly, and the modeling of rhodium and vanadium emitter depletion using MCNP and ORIGEN-S codes, and the realistic energy spectrum of beta rays using BETA-S code. The results of the simulations show that the lifetime of an SPND can be prolonged by using vanadium SPND than rhodium SPND. Also, the methods presented here can be used to analyze a life-time of those SPNDs using various emitter materials.

SOME OUTSTANDING PROBLEMS IN NEUTRON TRANSPORT COMPUTATION

  • Cho, Nam-Zin;Chang, Jong-Hwa
    • Nuclear Engineering and Technology
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    • 제41권4호
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    • pp.381-390
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    • 2009
  • This article provides selects of outstanding problems in computational neutron transport, with some suggested approaches thereto, as follows: i) ray effect in discrete ordinates method, ii) diffusion synthetic acceleration in strongly heterogeneous problems, iii) method of characteristics extension to three-dimensional geometry, iv) fission source and $k_{eff}$ convergence in Monte Carlo, v) depletion in Monte Carlo, vi) nuclear data evaluation, and vii) uncertainty estimation, including covariance data.

동자침(洞刺鍼)과 풍지혈(風池穴) 자락(刺絡)의 혈압강하(血壓降下) 효과(效果) (The Depressive Effect of Acupuncture on Dong and Depletion on Fungchi-point (G20))

  • 박인범;김상우;김철홍;서정철;윤현민;장경전;송춘호;안창범
    • Journal of Acupuncture Research
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    • 제20권1호
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    • pp.13-21
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    • 2003
  • Objective : The aim of this research was to investigate the depressive effect of acupuncture on Dong and depletion on Fungchi-point(G20) in stroke patients. Methods : We measured the blood pressure of the patients who were admitted in the Oriental Medical hospital of Dongeui medical center from 21. Dec. 2001. to 2. Oct. 2002. 41 stroke patients were devided into two groups. 15 patients were treated by acupuncture on Dong. The other 26 patients were treated by depletion on Fungchi-point(G20). The activity of daily living was measured. If systolic blood pressure was over 160 mmHg or diastolic blood pressure was over 90mmHg, acupuncture on Dong and depletion on Fungchi-point(G20) were performed. Then 30 minutes and 60 minutes later, systolic. diastolic blood pressure and pulse rates were measured. Results : After 30 minute of treatment, both acupuncture on Dong and depletion on Fungchi-point(G20) significantly depressed systolic blood pressure and diastolic blood pressure. After 60 minute of treatment, both acupuncture on Dong and depletion on Fungchi-point(G20) were significant in depressing systolic blood pressure and diastolic blood pressure. Pulse rates significantly changed in depletion on Fungchi-point(G20) but did not significantly change in acupuncture on Dong. Conclusions: These results suggest that both acupuncture on Dong and depletion on Fungchi-point(G20) are effective in depressing systolic blood pressure and diastolic blood pressure.

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Compact Model of a pH Sensor with Depletion-Mode Silicon-Nanowire Field-Effect Transistor

  • Yu, Yun Seop
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권4호
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    • pp.451-456
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    • 2014
  • A compact model of a depletion-mode silicon-nanowire (Si-NW) pH sensor is proposed. This drain current model is obtained from the Pao-Sah integral and the continuous charge-based model, which is derived by applying the parabolic potential approximation to the Poisson's equation in the cylindrical coordinate system. The threshold-voltage shift in the drain-current model is obtained by solving the nonlinear Poisson-Boltzmann equation for the electrolyte. The simulation results obtained from the proposed drain-current model for the Si-NW field-effect transistor (SiNWFET) agree well with those of the three-dimensional (3D) device simulation, and those from the Si-NW pH sensor model also agree with the experimental data.

홀측정을 이용한 ZTO 반도체 박막계면에서의 터널링 효과 (The Tunneling Effect at Semiconductor Interfaces by Hall Measurement)

  • 오데레사
    • 한국재료학회지
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    • 제29권7호
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    • pp.408-411
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    • 2019
  • ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.

식이 내의 타우린 함량이 고양이의 혈액 및 주유조직의 유리 아미노산 농도에 미치는 영향 (Effect of Dietary Taurine on Free Amino Acid Concentrations in Blood and Various Tissues of Cats)

  • 박태선
    • Journal of Nutrition and Health
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    • 제28권9호
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    • pp.846-854
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    • 1995
  • Taurine concentrations in blood and various tissues were measured in cats fed normal trurine diet(0.15% taurine) and trurine-free diet(0% taurine) for 5 weeks and 12 weeks, respectively. Cumulative body weight gain in young cats fed normal taurine diet and taurine-free diet for the initial 5 weeks were 463$\pm$43g and 383$\pm$53g respectively. Taurine concentration was one to two orders magnitude higher in most tissues than in plasma, among which the liver taurine-free diet for 12 weeks resulted in 98% reduction in plasma taurine concentration, 93% reduction in whole blood tarurine concentration, and 40~90% reduction in tissue taurine concentrations compared to the values for normal taurine diet group. Among the tissues tested, taurine depletion was most profound in heart and kidney, while liver and intestine were relatively resistant to taurine depletion. Whole blood taruined concentration appeared to be a better index for the body taurine status of cats as in more closely reflects the rate of taurine depletion in tissues. Taurine depletion in cats significantly increased the concentrations of essential and non-essential free amino acids in liver, while free amino acid concentrations in other tissues were not affected by taurine depletion.

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해석적 모형을 이용한 심부대수층 지하수 양수로 인한 하천수 감소량 분석 (Evaluation of Stream Depletion from Groundwater Pumping in Deep Aquifer Using An Analytical Model)

  • 이정우;정일문;김남원
    • 대한토목학회논문집
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    • 제36권5호
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    • pp.769-777
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    • 2016
  • 본 연구에서는 2층 누수대수층 시스템에 관한 Ward and Lough (2011)의 해석해를 이용하여 심부대수층 양수로 인한 하천수 감소량을 분석하였다. 하천변에 위치한 110개 지하수 관정 각각에 대해 양수량 대비 하천수 감소량을 산정한 결과 양수기간 5년 동안 작게는 0.1미만에서 크게는 0.8을 초과하여 관정 위치에 따라 큰 차이를 나타내었다. 단일 대수층 구조에 대한 Hunt (1999) 해석해 적용 결과와의 비교를 통해서 Ward and Lough (2011)의 해석해로 구한 하천수 감소량은 두 층의 수리특성의 상이함과 연직 방향 지체의 영향으로 평균적으로 약 50 % 만큼 작게 산정되었다. 충적층에 대한 하천고갈인자가 약 1,000 보다 크거나 암반층의 하천고갈인자가 100보다 큰 경우, 또는 연직 누수계수가 $10^{-5}s^{-1}$보다 작을 경우에는 지하수 양수가 하천수 감소에 미치는 영향이 작은 것으로 분석되었다. 또한 미 측정값인 충적층의 투수량계수 및 저류계수, 충적층과 연결된 하천의 하상수리전도도, 암반층 연직수리전도도 등의 크기에 따른 하천수 감소량의 변동 특성을 평가하였다.

직장 내 괴롭힘이 정서적 고갈 및 조직몰입에 미치는 영향에 관한 연구 - 사회적 지원의 역할 (A Study on the Effects of Workplace Bullying on Emotional Depletion and Organizational Commitment-The Role of Social Support)

  • 정해숙;김현;현병환
    • 한국콘텐츠학회논문지
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    • 제21권12호
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    • pp.463-476
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    • 2021
  • 본 연구는 직장 내 괴롭힘이 정서적 고갈 및 조직몰입에 미치는 영향에 유의한 차이를 살펴보고, 사회적 지원에 따른 유의한 차이가 있을 것인가를 고찰해 보고자 400부의 설문지를 활용하였다. 분석 방법으로 표본 특성에는 SPSS 24를 사용, 확인적 요인 분석, 신뢰도 및 타당도, 경로 분석, 구조방정식 모형에는 SmartPLS 3 통계 프로그램을 사용하였다. 연구 결과로는, 직장 내 괴롭힘은 정서적 고갈에 유의한 정(+)에 영향을 미치며, 정서적 고갈은 조직몰입에 유의한 부(-)의 영향을 미치는 것으로 나타났다. 직장 내 괴롭힘과 조직몰입 사이의 영향 관계에서 정서적 몰입은 부(-)의 방향으로 부분 매개하였고, 정서적 고갈이 조직몰입에 미치는 영향은 사회적 지원의 조절에 유의한 차이가 있는 것으로 나타났다. 시사점으로는 직장 내 괴롭힘은 정서적 고갈에 영향을 미치므로 괴롭힘을 예방하는 기업의 노력이 절실히 요구되며, 조직 내 상사와의 의사소통을 증진할 수 있는 제도나 커뮤니티를 활용하여 종사자들의 조직몰입을 향상할 수 있음을 시사해 주고 있다.

Trimethyl-indium 소스 고갈에 따른 InGaAsP 에피층의 특성 변화 (Effect of trimethyl-indium source depletion on InGaAsP epilayer grown by MOCVD)

  • 김현수;오대곤;편광의;최인훈
    • 한국진공학회지
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    • 제9권4호
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    • pp.400-405
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    • 2000
  • 유기금속 소스의 농도를 연속적으로 in-situ 측정이 가능한 EPISON ultrasonic monitor를 이용하여 TMIn(trimethly-indium)의 소스 고갈이 InGaAs, InGaAsP bulk 에피층과 1.55 $mu extrm{m}$ InGaAs/InGaAsP SMQW (strained multi-quantum well)에 미치는 영향을 조사하였다. TMIn 소스는 사용량이 80%에서 급격하게 소스 고갈 현상을 보였다. TMIn 소스는 사용량이 80%에서 급격하게 소스 고갈 현상을 보였다. TMIn 소스 고갈에 의한 에피층의 특성 변화를 조사한 결과, bulk 에피층의 경우에는 소스가 고갈 되기 전에 성장한 에피층과 비교하여 DCXRD(double crystal X-ray diffractometry) spectrum에서 피크 분리가 약 300 arcsec정도 Ga-rich 방향으로 이동하였으며 relative FWHM은 약 2배 가량 증가하는 것을 보였다. SMQW 구조에서는 bulk 에피층과는 달리, PL 중심파장에서도 약 40 nm 정도 단파장쪽으로 이동하였으며, 피크 분리는 약 300 arcsec정도 Ga-rich 방향으로 이동하였다. 하지만, EPISON의 closed loop 기능을 사용할 경우에는 TMIn 소스 사용량이 95%에서도 피크 분리가 $\pm$100 arcsec이내의 재현성 있는 에피층 성장이 가능하다는 것을 알 수 있었다.

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