• 제목/요약/키워드: Trace component

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Invariant Trace Fields of Chain Links

  • Ryou, Kazuhiro
    • Kyungpook Mathematical Journal
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    • 제56권1호
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    • pp.257-271
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    • 2016
  • In this paper, we compute the trace field of C(2, s), the complement of two component chain link with s left half twists in ${\mathbb{S}}^3$, for every s. As a result, for every $n{\in}{\mathbb{N}}{\backslash}\{1\}$, we can find $s{\in}{\mathbb{Z}}$ such that the degree of the trace field of C(2, s) is n. We also prove that if for fixed p, the degree of the trace field of C(p, s) runs over ${\mathbb{N}}{\backslash}\{1\}$, then p is contained in {1, 2, 4, 8}.

GC/AED를 이용한 HFC-134a의 미량 불순물 분석 (Determination of trace impurities of HFC-134a by gas chromatograph with atomic emission detector (GC/AED))

  • 김명자;임정식;이진복;이정순
    • 분석과학
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    • 제30권5호
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    • pp.240-251
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    • 2017
  • 1,1,1,2-수소불화탄소(HFC-134a)는 에어컨에 주로 사용되는 냉매로, 최근 온실가스로 규제되어 정제를 통한 재사용 방법이 권장되고 있다. 폐냉매의 재사용 기준 평가를 위해서는 폐냉매에 존재하는 미량 성분의 정량분석이 매우 중요하다. 본 연구에서는 표준 물질이 없어서 정량화하기 어려웠던 C, H, Cl, F가 포함된 미량 성분들을 GC/AED (gas chromatograph-atomic emission detector)를 이용하여 정량분석하였다. 이를 위하여 GC/MSD (mass selective detector)를 통한 정성분석을 선행하였다. 또한 성분의 원자 수와 비례하여 반응하는 AED의 특성을 조사하기 위하여, 탄화수소 혼합 표준물질을 이용하여 선형성을 확인하였다. 시료 중 C, H, Cl, F가 포함된 미량 성분의 정성 분석 결과, 주성분인 HFC-134a와 유사 냉매류들을 포함한 총 15 개의 성분이 검출되었다. MSD 결과를 토대로 AED를 이용한 미량 성분들을 정량 분석한 결과, 한 시료는 $CHClF_2$ 성분($45438.38{\mu}mol/mol$), 또 다른 시료는 $C_2H_2ClF_3$ 성분($1311.47{\mu}mol/mol$)이 가장 높은 몰분율을 나타냈다. 본 연구에서는 이 분석법을 기반으로 하여, 표준 물질이 존재하지 않아 정량화하기 어려운 복합 성분들의 정성 및 정량 분석의 확장 적용이 가능할 것으로 보인다.

'아날로그-디지털 인터랙션 흔적'에 관한 개념 연구와 미디어 아트에의 응용 (A study of the Concept of Analogue-Digital Interaction Trace and its Application in Media Art)

  • 최민아;권두영
    • 한국콘텐츠학회논문지
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    • 제11권9호
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    • pp.76-84
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    • 2011
  • 본 논문에서는 인터랙티브 미디어 작품 제작에 적용 가능한 개념을 제안하고 개념이 적용된 미디어 아트작품에 대한 사용자 경험과 그것에 대한 결과물을 통해 개념의 타당성과 그 가능성을 시험해보고자 한다. 이를 위해 사용자 인터랙션 흔적을 아날로그와 디지털 형태로 남기도록 하는 '에이디-트레이스(AD-Trace)'라는 개념을 세우고, 이를 적용한 다양한 인터랙티브 미디어 아트 작품 창작을 시도하였다. 에이디-트레이스는 디자인 요소로서 '아날로그 흔적(Analogue Trace)', '디지털 흔적(Digital Trace)', 그리고 두 요소를 연결하면서 사용자의 인터랙션을 유도하여 보다 의미 있는 흔적을 남길 수 있도록 지원하는 '인터랙션 메타포(Interaction Metaphor)'를 갖는다. 이 세 가지 요소는 본 연구자의 세 개 작품인 '에이디-피디(AD-PD)', '에이디-스타(AD-Star)', 그리고 '에이디-맵(AD-Map)'에서 각 작품의 콘셉트에 맞게 디자인 되었으며, 사용자 참여 후 얻어진 결과물을 통해 에이디-트레이스가 가질 수 있는 특성을 분석하였다.

Detection of Toxic Heavy Metal, Co(II) Trace via Voltammetry with Semiconductor Microelectrodes

  • Ly, Suw Young;Lee, Chang Hyun;Koo, Jae Mo
    • Toxicological Research
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    • 제33권2호
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    • pp.135-140
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    • 2017
  • The cobalt (Co(II)) ion is a main component of alloys and considered to be carcinogenic, especially due to the carcinogenic and toxicological effects in the aquatic environment. The toxic trace of the Co(II) detection was conducted using the infrared photodiode electrode (IPDE) using a working electrode, via the cyclic and square-wave anodic stripping voltammetry. The results indicated a sensitive oxidation peak current of Co(II) on the IPDE. Under the optimal conditions, the common-type glassy carbon, the metal platinum, the carbon paste, and the carbon fiber microelectrode were compared with the IPDE in the electrolyte using the standard Co(II). The IPDE was found to be far superior to the others.

EFFECTS OF TRACE METALS ON PARTICULATE MATTER FORMATION IN A DIESEL ENGINE: METAL CONTENTS FROM FERROCENE AND LUBE OIL

  • Lee, D.G.;Miller, A.;Park, K.H.;Zachariah, M.R.
    • International Journal of Automotive Technology
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    • 제7권6호
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    • pp.667-673
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    • 2006
  • Diesel particulate matter(DPM) often contains small amounts of metal as a minor component but this metal may contribute to adverse health effects. Knowledge of the mechanism for particle formation as well as the size preference of the trace metals is critical to understanding the potential for health concerns. To achieve this, the size and the composition of each particle should be optimally measured at the same time. Single particle mass spectrometer(SPMS) would be the best tool for this objective. In this paper, we therefore will introduce new findings about the mechanism and distribution of the trace metals in DPM, derived from a study where an SPMS was used to analyze freshly emitted DPM.

Experimence Study of Trace Water and Oxygen Impact on SF6 Decomposition Characteristics Under Partial Discharge

  • Zeng, Fuping;Tang, Ju;Xie, Yanbin;Zhou, Qian;Zhang, Chaohai
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1786-1795
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    • 2015
  • It is common practice to identify the insulation faults of GIS through monitor the contents of SF6 decomposed components. Partial discharges (PD) could lead to the decomposition of SF6 dielectric, so new reactions usually occur in the mixture of the newly decomposed components including traces of H2O and O2. The new reactions also cause the decomposed components to differ due to the different amounts of H2O and O2 even under the same strength of PD. Thus, the accuracy of assessing the insulation faults is definitely influenced when using the concentration and corresponding change of decomposed components. In the present research, a needle-plate electrode was employed to simulate the PD event of a metal protrusion insulation fault for two main characteristic components SO2F2 and SOF2, and to carry out influence analysis of trace H2O and O2 on the characteristic components. The research shows that trace H2O has the capability of catching an F atom, which inhibits low-sulfide SFx from recombining into high-sulfide SF6. Thus, the amount of SOF2 strongly correlates to the amount of trace H2O, whereas the amount of SO2F2 is weakly related to trace H2O. Furthermore, the dilution effect of trace O2 on SOF2 obviously exceeds that of SO2F2.

FRACTIONAL ORDER SOBOLEV SPACES FOR THE NEUMANN LAPLACIAN AND THE VECTOR LAPLACIAN

  • Kim, Seungil
    • 대한수학회지
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    • 제57권3호
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    • pp.721-745
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    • 2020
  • In this paper we study fractional Sobolev spaces characterized by a norm based on eigenfunction expansions. The goal of this paper is twofold. The first one is to define fractional Sobolev spaces of order -1 ≤ s ≤ 2 equipped with a norm defined in terms of Neumann eigenfunction expansions. Due to the zero Neumann trace of Neumann eigenfunctions on a boundary, fractional Sobolev spaces of order 3/2 ≤ s ≤ 2 characterized by the norm are the spaces of functions with zero Neumann trace on a boundary. The spaces equipped with the norm are useful for studying cross-sectional traces of solutions to the Helmholtz equation in waveguides with a homogeneous Neumann boundary condition. The second one is to define fractional Sobolev spaces of order -1 ≤ s ≤ 1 for vector-valued functions in a simply-connected, bounded and smooth domain in ℝ2. These spaces are defined by a norm based on series expansions in terms of eigenfunctions of the vector Laplacian with boundary conditions of zero tangential component or zero normal component. The spaces defined by the norm are important for analyzing cross-sectional traces of time-harmonic electromagnetic fields in perfectly conducting waveguides.

Analysis of LBLOCA of APR1400 with 3D RPV model using TRACE

  • Yunseok Lee;Youngjae Lee;Ae Ju Chung;Taewan Kim
    • Nuclear Engineering and Technology
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    • 제55권5호
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    • pp.1651-1664
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    • 2023
  • It is very difficult to capture the multi-dimensional phenomena such as asymmetric flow and temperature distributions with the one-dimensional (1D) model, obviously, due to its inherent limitation. In order to overcome such a limitation of the 1D representation, many state-of-the-art system codes have equipped a three-dimensional (3D) component for multi-dimensional analysis capability. In this study, a standard multi-dimensional analysis model of APR1400 (Advanced Power Reactor 1400) has been developed using TRACE (TRAC/RELAP Advanced Computational Engine). The entire reactor pressure vessel (RPV) of APR1400 has been modeled using a single 3D component. The fuels in the reactor core have been described with detailed and coarse representations, respectively, to figure out the impact of the fuel description. Using both 3D RPV models, a comparative analysis has been performed postulating a double-ended guillotine break at a cold leg. Based on the results of comparative analysis, it is revealed that both models show no significant difference in general plant behavior and the model with coarse fuel model could be used for faster transient analysis without reactor kinetics coupling. The analysis indicates that the asymmetric temperature and flow distributions are captured during the transient, and such nonuniform distributions contribute to asymmetric quenching behaviors during blowdown and reflood phases. Such asymmetries are directly connected to the figure of merits in the LBLOCA analysis. Therefore, it is recommended to employ a multi-dimensional RPV model with a detailed fuel description for a realistic safety analysis with the consideration of the spatial configuration of the reactor core.

한국산 구약감자의 이화학적 성분조사 (Studies on the Physico-chemical Components of Elephant-foot Produced in Korea)

  • 이성갑
    • 한국식생활문화학회지
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    • 제10권5호
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    • pp.443-448
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    • 1995
  • Korean fresh elephant-foot (Amorphophalus konjak K. Koch) and its powder were analyzed and compared with foreign samples to investigate the physico-chemical characteristics of Korean konjak. The Korean fresh konjak contained 80.6% of moisture content and most of the solid component comprises much of sugar, protein and trace of fat and fibre. The mannan content of Korean konjak powder is far smaller than those of Japanese and Chinese konjak powder. The analysis of the Korean konjak revealed that glutamic acid, aspartic acid and arginine included 45% of total amount, and other amino acid was incresaed with the order of valine, serine, leucine and glycine. The Korean konjak contained a moderate amount of K component and other inorganic component was larger with the order of P, Na and Ca. The yield of refined powder obtained from dried chip of Konjak was 61.0% in Korean one and 57.5% in Chinese one. The degree of lightness of Chinese konjak powder was slightly higher than that of Korean product, but the difference could not be recognized by naked eye.

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Comprehensive studies of Grassmann manifold optimization and sequential candidate set algorithm in a principal fitted component model

  • Chaeyoung, Lee;Jae Keun, Yoo
    • Communications for Statistical Applications and Methods
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    • 제29권6호
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    • pp.721-733
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    • 2022
  • In this paper we compare parameter estimation by Grassmann manifold optimization and sequential candidate set algorithm in a structured principal fitted component (PFC) model. The structured PFC model extends the form of the covariance matrix of a random error to relieve the limits that occur due to too simple form of the matrix. However, unlike other PFC models, structured PFC model does not have a closed form for parameter estimation in dimension reduction which signals the need of numerical computation. The numerical computation can be done through Grassmann manifold optimization and sequential candidate set algorithm. We conducted numerical studies to compare the two methods by computing the results of sequential dimension testing and trace correlation values where we can compare the performance in determining dimension and estimating the basis. We could conclude that Grassmann manifold optimization outperforms sequential candidate set algorithm in dimension determination, while sequential candidate set algorithm is better in basis estimation when conducting dimension reduction. We also applied the methods in real data which derived the same result.