• Title/Summary/Keyword: ParA

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Development and validation of diffusion based CFD model for modelling of hydrogen and carbon monoxide recombination in passive autocatalytic recombiner

  • Bhuvaneshwar Gera;Vishnu Verma;Jayanta Chattopadhyay
    • Nuclear Engineering and Technology
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    • v.55 no.9
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    • pp.3194-3201
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    • 2023
  • In water-cooled power reactor, hydrogen is generated in case of steam zirconium reaction during severe accident condition and later on in addition to hydrogen; CO is also generated during molten corium concrete interaction after reactor pressure vessel failure. Passive Autocatalytic Recombiners (PARs) are provided in the containment for hydrogen management. The performance of the PARs in presence of hydrogen and carbon monoxide along with air has been evaluated. Depending on the conditions, CO may either react with oxygen to form carbon dioxide (CO2) or act as catalyst poison, reducing the catalyst activity and hence the hydrogen conversion efficiency. CFD analysis has been carried out to determine the effect of CO on catalyst plate temperature for 2 & 4% v/v H2 and 1-4% v/v CO with air at the recombiner inlet for a reported experiment. The results of CFD simulations have been compared with the reported experimental data for the model validation. The reaction at the recombiner plate is modelled based on diffusion theory. The developed CFD model has been used to predict the maximum catalyst temperature and outlet species concentration for different inlet velocity and temperatures of the mixture gas. The obtained results were used to fit a correlation for obtaining removal rate of carbon monoxide inside PAR as a function of inlet velocity and concentrations.

Balancing Speed, Precision, and Flexibility

  • Tanaka, Yoke
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.937-940
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    • 1993
  • A new hardware architecture achieves high speed, high precision fuzzy inference capabilities while maintaining Flexibility on par with software approaches. This flexibility allows unmodified, uncompromised porting of fuzzy system designs into hardware. The architecture is also scalable and offers data resolutions from 8 bits to 32 bits.

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Evaluation of the daylight performance of four-sided atria with various well configurations for interior vegitation growth (실내 조경 식물의 생육을 고려한 4면형 아트리움의 형태변수별 자연채광 성능평가)

  • Song, Il-Hak;Kim, Ji-Hyun;Song, Kyoo-Dong
    • KIEAE Journal
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    • v.11 no.5
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    • pp.137-143
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    • 2011
  • An atrium space, unlike ordinary office rooms, accommodates variety of activities such as moving and resting of people and usually houses variety of vegitation to improve amenity and indoor environment. Many atrium buildings in Korea have been designed by considering the environmental criteria for human beings, not for the vegitation in the atrium space. Especially the daylighting designs are mostly focused on the required illuminances for various visual tasks of the occupants and glare controls. As a result, some atrium spaces do not provide sufficient light to the interior plants. Consequently, these atrium spaces require a high level of electric lighting to compensate the deficit of natural light for the photosynthesis of the vegitation. The purpose of this study was to suggest design guidelines for 4-sided atrium spaces having different well indices (WI), plan aspect ratio (PAR), and cardinal orientation. The findings from this study might be referenced by building designers when designing or selecting canopy systems by considering the daylight performances of the uncovered atrium spaces. In the study, the daylight performance was evaluated in terms of daylight autonomy (DA).

A Comparison Study on Isoprene Emission Rates from White Oak (갈참나무로부터 발생되는 이소프렌의 배출속도 비교 연구)

  • Son, Youn-Suk;Kim, Jo-Chun;Kim, Ki-Joon;Lim, Yong-Jae;SunWoo, Young;Hong, Ji-Hyung
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.6
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    • pp.791-798
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    • 2006
  • In order to investigate the NVOC (Natural Volatile Organic Compound) emissions from White Oak, the emission rates of isoprene were measured according to season, weather conditions, and the age of the tree. The analysis of seasonal emission rates showed that the emission rates were the highest during summer followed by spring and fall. The emission rates during summer were found to be nearly 8 times greater than those during fall. In addition, it was observed that the emission rates of isoprene depends on PAR and temperature. Moreover, the effect of age on the emission rates was studied, and the White Oak in the age range of $21{\sim}30$ had higher emission rates than that in the range of $41{\sim}50$. Accordingly, the current result indicates that the isoprene emissions are affected by both meteorological parameter and the age of a tree.

Fractionnement des produits de $r{\acute{e}}action$ de Maillard par $diff{\acute{e}}rentes$ techniques et observation $d'activit{\acute{e}}$ fermentaire do ces fractions -II. Fractionnement par chromatographie de partage- (여러가지 방법(方法)에 의(依)한 Premelanoidin의 분획(分劃)과 그 분획물(分劃物)의 발효활성(醱酵活性)에 관(關)한 관찰(觀察) -II. 분배(分配)크로마토고라피에 의(依)한 분획(分劃)-)

  • Lee, Yang-Hee;Petit, Leon;Fittes, Eliane
    • Applied Biological Chemistry
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    • v.11
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    • pp.101-104
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    • 1969
  • Partition chromatography의 방법(方法)으로는 우선 cellulose powder colume을 시도해 보았으나 이는 얻어진 fraction의 용매제거의 난점(難點)이 있으므로 결국(結局) paper chromatography 방법(方法)만을 사용(使用)하였다. 연구결과(硏究結果)로는 우선 갈색색소의 fraction에 있어서 발효초기(醱酵初期)에 약간의 활성(活性)을 관찰(觀察)할수 있었으며 glycine이 함유된 fraction 에서는 발효초기에 벌써 상당한 활성을 보였으며 이는 또한 발효의 진행(進行)에 따라 점차 증가되었다. 그리고 N-glycoside의 fraction에서는 발효초기에 미약(微弱)한 활성(活性)을 관찰할 수 있었다. 그러나 paper chromatography의 방법(方法)은 본실험(本實驗)에 적합하지 않다고 생각되며 그 이유(理由)는 일회(一回)에 fractionation 할수있는 시료(試料)의 양(量)이 극(極)히 제한되어 있다는 점(點)과 또 fractionation 도중에 타물질(他物質)의 오염으로 인(因)해서 시료(試料)의 정확(正確)한 발효 활성(活性)을 측정(測定)할수 없다는 것이다.

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Fractionnement des produits de $r{\acute{e}}action$ de Maillard par $diff{\acute{e}}rentes$ techniques et observation $d'activit{\acute{e}}$ fermentaire do ces fractions -III. Fractionnement par gel-filtration sur 'Sephadex'- (여러가지 방법(方法)에 의(依)한 Premelanoidin의 분획(分劃)과 그 분획물(分劃物)의 발효활성(醱酵活性)에 관(關)한 관찰(觀察) -III Gel-filtration에 의(依)한 분획(分劃)-)

  • Lee, Yang-Hee;Petit, Leon;Fittes, Eliane
    • Applied Biological Chemistry
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    • v.11
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    • pp.105-108
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    • 1969
  • 본(本) 실험(實驗)에 사용(使用)된 Gel로는 Sephadex G-200, G-100과 G-75로써 fractionation은 대체(大體)로 호조건에서 이루어 졌다. G-200과 G-100의 경우에 있어서는 갈색색소의 분자크기가 서로 다른 2개(個)의 Peak를 얻을 수 있었고 Colume에 투입된 시료(試料)는 완전(完全)히 회수(回收)되었다. G-75의 경우에는 갈색색소와 분자 크기가 작은 다른 물질(物質)과를 분리(分離)할 수 있었으나 약간의 시료(試料)는 Gel에 흡착되어 완전(完全)히 회수(回收)할 수 없었다. 발효실험의 결과를 종합해 보면 우선 갈색색소를 함유하늘 모든 fraction은 발효초기에 활성(活性)을 보이며 분자크기가 작은 물질의 구획(區劃)에서는 강하고도 점증되는 활성(活性)을 관찰할 수 있었다. Sephadex Gel에 의(依)한 fractionation은 첫째로 작업(作業)도중에 시료(試料)의 변질현상(變質現象)이 없다는 것과 둘째로 갈색색소를 그들의 분자크기에 따라 분획(分劃)할 수 있다는 이점(利點)들이 있다.

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Flux of Carbon Dioxide and Deposition Velocity of Ozone over Glycine max Canopy (대두 개체군에 있어서 $CO_2$$O_3$ 플럭스)

  • 김원식;이호준
    • The Korean Journal of Ecology
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    • v.23 no.1
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    • pp.39-43
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    • 2000
  • Carbon dioxide (CO₂) and ozone (O₃) fluxes were measured over Glycine max canopy using the bowen ratio energy balance method at Fuchu - 20 km west of Tokyo, in late July and late September 1996. The CO₂, and O₃, fluxes were influenced by variation in leaf area index (LAI) during the measuring period. When LAI was more than 3.0, the CO₂ flux was found to be positively correlated with photosynthetically active radiation (PAR). The O₃, flux was always positive with an average deposition velocity for this case of about 0.5 mol m/sup -2/s/sup -1/. A positive correlation existed between the deposition velocity of O₃ and CO₂ during the period of LAI>2.0.

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The Separation and Determination of Rare Earth Elements by Ion-Association Chromatography (희토류 원소의 분리 및 정량을 위한 이온회합 크로마토그래피)

  • Lee, Seung Hwa;Lee, Cheol;Jeong, Koo Soon
    • Journal of the Korean Chemical Society
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    • v.34 no.1
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    • pp.69-75
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    • 1990
  • An ion-association chromatography was applied for the separation and determination of individual rare earth elements (REE) contained in mineral monazite. Prior to the determination, the group separation of REE was achieved by a cation exchange column of Dowex 5OW-X8 resin. The quantitative recovery of REE by the resin column, free from coexisting elements in monazite, was confirmed with radioactive tracers as well as with ICP-MS. Individual REE at ppm level was separated on reversed-phase column ($\mu$-Bondapak $C_{18}$) using gradient elution from 0.05 to 0.3 M $\alpha$-hydroxyisobutyric acid at pH 4.6. The individual REE was detected at 546 nm following post-column reaction with PAR (4-(2-pyridylazo)-resorcinol monosodium salt).

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Evaluation of Mulberry Germplasm (Morns spp.) for Leaf Yield and Quality through Bioassay

  • Tikader, A.;Kamble, C. K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.2
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    • pp.87-92
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    • 2007
  • Twenty - four elite mulberry germplasm each of indigenous and exotics were studied for their leaf yield and compared with commercial check ($V_1$ and Kosen). Accession MI-0416 and ME-0169 out yielded the check accession in leaf yield/plant. The other few mulberry germplasm were also performed at par with the checks. For quality test and bioassay were conducted with the leaves of selected mulberry germplasm. Among the selected twelve mulberry accessions used for bioassay, MI-0376 and ME-033 performed better than check ($V_1$, Kosen). Other mulberry accessions i.e., MI-0310 and MI-0437 are on par with the check as far as the bioassay is concerned. MI-0376 and ME-0033 out yielded in rearing parameters and qualified for 11 and 10 rearing and related traits. Other mulberry accessions i.e., MI-0310 and MI-0437 were also qualified for eight rearing traits along with check ($V_1$). The mulberry accessions tested after selection from the preliminary characterization seems to be better and equally good in rearing and leaf yield compared to check ($V_1$, Kosen), which provides scope for selection and further evaluation. The selected mulberry accession may be included in crop improvement programme.