• 제목/요약/키워드: Source depletion

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Current Saturation Improvement of Poly-Si TFTs for Analog Circuit Integration

  • Nam, Woo-Jin;Han, Sang-Myeon;Lee, Hye-Jin;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.289-292
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    • 2005
  • New poly-Si TFTs have been proposed and fabricated in order to increases the output channel resistance ($r_o$). The counter-doped($p^+$) source is tied to the $n^+$ source and is extended into the channel region so that it employs the reverse bias depletion in the channel. As $V_{DS}$ is increased, the depletion width is increased and the effective channel width is reduced. Therefore, the output current saturates well and the $r_o$ is increased successfully. The proposed CMOS devices may improve the amplifier gain of data driver in active-matrix displays

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확장형칼만필터에 의한 연속회분식반응조의 탈질 적응제어 (Adaptive Control of Denitrification by the Extended Kalman Filter in a Sequencing Batch Reactor)

  • 김동한
    • 상하수도학회지
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    • 제20권6호
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    • pp.829-836
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    • 2006
  • The reaction rate of denitrification is primarily affected by the utilization of organics that are usually limited in the anoxic period in a sequencing batch reactor. It is necessary to add an extemal carbon source for sufficient denitrification. An adaptive model of state-space based on the extended Kalman filter is applied to manipulate the dosage rate of extemal carbon automatically. Control strategies for denitrification have been studied to improve control performance through simulations. The normal control strategy of the constant set-point results in the overdosage of external carbon and deterioration of water quality. To prevent the overdosage of external carbon, improved control strategies such as the constrained control action, variable set-point, and variable set-point after dissolved oxygen depletion are required. More stable control is obtained through the application of the variable set-point after dissolved oxygen depletion. The converging value of the estimated denitrification coefficient reflects conditions in the reactor.

Enhancement of $\beta$-D-Glucans Production by Agaricus blazei Murill by Nitrogen Supplementation

  • NA JEONG-GEOL;KIM HYUN-HAN;CHUN GIE-TAEK;CHANG YONG KEUN;LEE SANG JONG;CHUNG YEON HO
    • Journal of Microbiology and Biotechnology
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    • 제15권6호
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    • pp.1388-1391
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    • 2005
  • Temporal changes of cell growth pattern and intracellular content of $\beta$-D-glucans were investigated with off-gas data in Agaricus blazei culture where glucose was intermittently fed. It was observed that the time point of carbon source depletion coincided with the point of sudden drop in the carbon dioxide evolution rate (CER), and that the sole supplementation of glucose was not enough to maintain active cell growth and glucan content. On the other hand, when yeast extract, a typical nitrogen source, was supplemented together with glucose when the CER suddenly dropped because of carbon source depletion, an active cell growth could be maintained until the end of the culture and the glucan content did not decrease with culture time, significantly enhancing glucan productivity.

공핍형 SOI MOSFET를 이용한 5GHz대역 저잡음증폭기 (A 5GHz-Band Low Noise Amplifier Using Depletion-type SOI MOSFET)

  • 김규철
    • 한국정보통신학회논문지
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    • 제13권10호
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    • pp.2045-2051
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    • 2009
  • SOI MOSFET를 이용하여 5GHz대역 저잡음 증폭기를 설계하였다. 잡음특성을 향상시키기 위해 공핍형 SOI-MOSFET를 사용하였고, 저전압에서 동작시키기 위해 소스접지와 게이트접지 증폭기를 연결한 2단형으로 설계 하였다. 제작된 LNA는 5.5GHz에서 이득이 21dB, S11이 -10dB이하, 소비전력 8.3mW의 결과를 얻었으며 잡음지수는 공핍형 저잡음 증폭기가 1.7dB로 일반형보다 0.3dB 개선된 결과를 얻을 수 있었다. 이 같은 결과로 공핍형 SOI MOSFET를 사용함으로써 보다 잡음특성이 우수한 CMOS LNA를 설계 할 수 있음을 확인하였다.

Investigating the Impact of Best Management Practices on Nonpoint Source Pollution from Agricultural Lands

  • 최예환
    • 한국농공학회지
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    • 제32권E호
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    • pp.1-19
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    • 1990
  • Abstract Over the last several decades, crop production in the United States increased largely due to the extensive use of animal waste and fertilizers as plant nutrient supplements, and pesticides for crops pests and weed control. Without the application of animal waste best management, the use of animal waste can result in nonpoint source pollution from agricultural land area. In order to increase nutrient levels and decrease contamination from agricultural lands, nonpoint source pollution is responsible for water quality degradation. Nonpoint source pollutants such as animal waste, ferilizers, and pesticides are transported primarily through runoff from agricultural areas. Nutrients, primarily nitrogen and phosphorus, can be a major water quality problem because they cause eutrophic algae growth. In 1985, it was presented that Watershed/Water Quality Monitoring for Evaluation BMP Effectiveness was implemented for Nomini Creek Watershed, located in Westmoreland County, Virginia. The watershed is predominantly agricultural and has an aerial extent of 1505 ha of land, with 43% under cropland, 54% under woodland, and 3% as homestead and roads. Rainfall data was collected at the watershed from raingages located at sites PNI through PN 7. Streams at stations QN I and QN2 were being measured with V-notch weirs. Water levels at the stream was measured using an FW-l Belfort (Friez FWl). The water quality monitoring system was designed to provide comprehensive assessment of the quality of storm runoff and baseflow as influenced by changes in landuse, agronomic, and cultural practices ill the watershed. As this study was concerned with the Nomini Creek Watershed, the separation of storm runoff and baseflow measured at QNI and QN2 was given by the master depletion curve method, and the loadings of baseflow and storm runoff for TN (Total Nitrogen) and TP (Total Phosphorus) were analyzed from 1987 through 1989. The results were studied for the best management practices to reduce contamination and loss of nutrients, (e.g., total nitrogen and total phosphorus) by nonpoint source pollution from agricultural lands.

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공핍층 폭의 선형 변화를 가정한 단채널 MOSFET I-V 특성의 해석적 모형화 (Analytical Modeling for Short-Channel MOSFET I-V Characteristice Using a Linearly-Graded Depletion Edge Approximation)

  • 심재훈;임행삼;박봉임;여정하
    • 전자공학회논문지D
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    • 제36D권4호
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    • pp.77-85
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    • 1999
  • 본 논문은 진성영역에서 공핍증 폭이 선형적으로 변화한다는 가정을 도입하고 전자이동도의 수평 및 수직 전계 이존성을 고려하여 단채널 MOSFET의 {{{{ { I-V }_{ } }}}} 특성에 대한 해석적 모형을 제시하였다. 이 모형으로부터 전 동작영역에 걸쳐 적용되는 문턱전압 방정식과 드레인전류 방정식을 도출하였다. 본 모형의 타당성을 검토하기 위하여 위 식들의 계산을 수행하였고, 그 결과 채널길이가 짧아짐에 따라 문턱전압이 지수함수적으로 감소하였으며, 아울러 채널길이변조, 채널이동로 열화 등을 본 모형에 의하여 일괄적으로 설명할 수 있었다.

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The Morphology of Equatorial Plasma Bubbles - a review

  • Kil, Hyosub
    • Journal of Astronomy and Space Sciences
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    • 제32권1호
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    • pp.13-19
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    • 2015
  • Plasma bubbles that occur in the equatorial F-region make up one of the most distinguishing phenomena in the ionosphere. Bubbles represent plasma depletions with respect to the background ionosphere, and are the major source of electron density irregularities in the equatorial F-region. Such bubbles are seen as plasma depletion holes (in situ satellite observations), vertical plumes (radar observations), and emission-depletion bands elongated in the north-south direction (optical observations). However, no technique can observe the whole three-dimensional structure of a bubble. Various aspects of bubbles identified using different techniques indicate that a bubble has a "shell" structure. This paper reviews the development of the concepts of "bubble" and "shell" in this context.

Mitochondrial fatty acid metabolism in acute kidney injury

  • Jang, Hee-Seong;Padanilam, Babu J.
    • Journal of Medicine and Life Science
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    • 제15권2호
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    • pp.37-41
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    • 2018
  • Mitochondrial injury in renal tubule has been recognized as a major contributor in acute kidney injury (AKI) pathogenesis. Ischemic insult, nephrotoxin, endotoxin and contrast medium destroy mitochondrial structure and function as well as their biogenesis and dynamics, especially in renal proximal tubule, to elicit ATP depletion. Mitochondrial fatty acid ${\beta}$-oxidation (FAO) is the preferred source of ATP in the kidney, and its impairment is a critical factor in AKI pathogenesis. This review explores current knowledge of mitochondrial dysfunction and energy depletion in AKI and prospective views on developing therapeutic strategies targeting mitochondrial dysfunction in AKI.

Verification of a novel fuel burnup algorithm in the RAPID code system based on Serpent-2 simulation of the TRIGA Mark II research reactor

  • Anze Pungercic;Valerio Mascolino ;Alireza Haghighat;Luka Snoj
    • Nuclear Engineering and Technology
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    • 제55권10호
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    • pp.3732-3753
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    • 2023
  • The Real-time Analysis for Particle-transport and In-situ Detection (RAPID) Code System, developed based on the Multi-stage Response-function Transport (MRT) methodology, enables real-time simulation of nuclear systems such as reactor cores, spent nuclear fuel pools and casks, and sub-critical facilities. This paper presents the application of a novel fission matrix-based burnup methodology to the well-characterized JSI TRIGA Mark II research reactor. This methodology allows for calculation of nuclear fuel depletion by combination and interpolation of RAPID's burnup dependent fission matrix (FM) coefficients to take into account core changes due to burnup. The methodology is compared to experimentally validated Serpent-2 Monte Carlo depletion calculations. The results show that the burnup methodology for RAPID (bRAPID) implemented into RAPID is capable of accurately calculating the keff burnup changes of the reactor core as the average discrepancies throughout the whole burnup interval are 37 pcm. Furthermore, capability of accurately describing 3D fission source distribution changes with burnup is demonstrated by having less than 1% relative discrepancies compared to Serpent-2. Good agreement is observed for axially and pin-wise dependent fuel burnup and nuclear fuel nuclide composition as a function of burnup. It is demonstrated that bRAPID accurately describes burnup in areas with high gradients of neutron flux (e.g. vicinity of control rods). Observed discrepancies for some isotopes are explained by analyzing the neutron spectrum. This paper presents a powerful depletion calculation tool that is capable of characterization of spent nuclear fuel on the fly while the reactor is in operation.

EVALUATION OF THE UNCERTAINTIES IN THE MODELING AND SOURCE DISTRIBUTION FOR PRESSURE VESSEL NEUTRON FLUENCE CALCULATIONS

  • Kim, Yong-Il;Hwang, Hae-Ryong
    • Journal of Radiation Protection and Research
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    • 제26권3호
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    • pp.237-241
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    • 2001
  • The uncertainties associated with fluence calculation at the pressure vessel have been evaluated for the Korean Next Generation Reactor, APR1400. To obtain uncertainties, sensitivity analyses were performed for each of the parameters important to calculated fast neutron fluence. Among the important parameters to the overall uncertainties, reactor modeling and core neutron source were examined. Mechanical tolerances, composition and density variations in the reactor materials as well as application of $r-{\theta}$ geometry in rectilinear region contribute to uncertainty in the reactor modeling. Depletion and buildup of fissile nuclides, instrument error related to core power level, uncertainty of fuel pin burnup, and variation of long-term axial peaking factors are main contributors to the core neutron source uncertainty. The sensitivity analyses have shown that the uncertainty in the fluence calculation at the reactor pressure vessel is +12%.

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