• 제목/요약/키워드: N transfer

검색결과 1,862건 처리시간 0.026초

Solutions of Radiative Transfer for Nongray Gases within a 3-D Cylindrical Enclosure

  • Park, Won-Hee;Jung, Hyun-Sung;Kim, Tae-Kuk
    • International Journal of Aeronautical and Space Sciences
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    • 제3권1호
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    • pp.30-38
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    • 2002
  • In multi-dimensional systems, various solution schemes for radiative transfer are suggested but the applicabilities and accuracies of these schemes have not yet fully tested due to the lack of reference solutions especially for nongray gases. In this paper we present some precise radiative transfer solutions for a black walled 3-dimensional cylindrical system filled with nongray gases having uniform temperature and concentration. The ray-tracing method with the $T_N$ quadrature set and the SNB model are used to obtain the radiative transfer solutions by the nongray gases. The solutions presented in this paper are proved to be quite accurate and can be regarded as the reference solutions for the radiative transfer by nongray gases.

GIC 회로 및 그 응용에 관한 연구 (A Study on the GIC Circuit and Its Application)

  • 이영근
    • 대한전자공학회논문지
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    • 제9권3호
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    • pp.9-16
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    • 1972
  • 본논문은 "s"를 변환함수로 하는 GIC회로가 자이레이터와 마찬가지로 인덕터를 RC능동회로로서 실헐할 수 있고, 또 임의의 안정한 전달함수가 GIC를 포함한 2단자대회로의 open-circuit voltage ratio로서 실현될 수 있음을 밝힌 것이다. 트랜지스터를 사용하여 GIC회로를 구성함에 있어시 트랜지스터의 nullator-norator model이 적어도 10kHz 이하의 주파수 범위에서 훌륭하게 적용될 수 있음이 밝혀졌다. GIC를 사용한 회로합성법의 특징은 다음괴 같다. 첫째로, 임의의 안정한 전달함수는 대단히 단순한 회로구성을 되풀이함으로서 체계계적으로 또 기계적으로 실현될 수 있다. 둘째로, 전체 회로에 있어서 GIC를 제외한 모든 회로요소는 저항뿐이다. 셋째로 n차의 전달함수를 실현하는데 있어서 필요한 콘덴서의 수효는 n이며, 이것은 가능한 가장 적은 수효라고 믿어진다.

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Estimation of Energetic and Charge Transfer Properties of Iridium(III) Bis(2-phenylpyridinato-N,C2')acetylacetonate by Electrochemical Methods

  • Cha, Joeun;Ko, Eun-Song;Shin, Ik-Soo
    • Journal of Electrochemical Science and Technology
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    • 제8권2호
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    • pp.96-100
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    • 2017
  • Iridium(III) bis(2-phenylpyridinato-$N,C^{2^{\prime}}$)acetylacetonate ($(ppy)_2Ir(acac)$), a green dopant used in organic light-emitting devices (OLEDs), was subjected to electrochemical characterization to estimate its formal oxidation potential ($E^{o^{\prime}}$), HOMO energy level ($E_{HOMO}$), electron transfer rate constant ($k^{o^{\prime}}$), and diffusion coefficient ($D_o$). The employed combination of voltammetric methods, i.e., cyclic voltammetry (CV), chronocoulometry (CC), and the Nicholson method, provided meaningful insights into the electron transfer kinetics of $(ppy)_2Ir(acac)$, allowing the determination of $k^{o^{\prime}}$ and $D_o$. The quasi-reversible oxidation of $(ppy)_2Ir(acac)$ furnished information on $E^{o^{\prime}}$ and $E_{HOMO}$, allowing the latter parameter to be easily estimated by electrochemical methods without relying on expensive and complex ultraviolet photoemission spectroscopic (UPS) measurements.

The Study on the Physicochemical Properties of Fluid under High Pressure (Ⅱ). The Effect of Pressure and Temperature on the Hexamethyl Benzene-Iodine Charge Transfer Complex in n-Hexane

  • 권오천;김정림
    • Bulletin of the Korean Chemical Society
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    • 제6권4호
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    • pp.186-191
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    • 1985
  • The effect of pressure and temperature on the stabilities of the charge transfer complexes of hexamethyl benzene with iodine in n-hexane has been investigated by UV-spectrophotometric measurements. In this experiment the absorption spectra of mixed solutions of hexamethyl benzene and iodine in n-hexane were measured at 25, 40 and $60^{\circ}C$ under 1,200, 600, 1200 and 1600 bar. The equilibrium constant of the complex formation was increased with pressure while being decreased with temperature raising. Changes of volume, enthalpy, free energy and entropy for the formation of the complexes were obtained from the equilibrium constants. The red shift at higher pressure, the blue shift at higher temperature and the relation between pressure and oscillator strength were discussed by means of thermodynamic functions. In comparison with the results in the previous studies, it can be seen that the pressure dependence of oscillator strength has a extremum behavior in durene as the variation of ${\Delta}H$ or ${\Delta}S$ with the number of methyl groups of polymethyl benzene near atmospheric pressure in the previous study. The shift or deformation of the potential in the ground state and in the excited state of the complexes formed between polymethyl benzene and iodine was considered from the correlation between the differences of the electron transfer energies and the differences of free energies of the complex formation for the pressure variation.

The state space of a canonical linear system

  • Yang, Mee-Hyea
    • 대한수학회지
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    • 제32권3호
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    • pp.447-459
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    • 1995
  • A fundamental problem is to construct linear systems with given transfer functions. This problem has a well known solution for unitary linear systems whose state spaces and coefficient spaces are Hilbert spaces. The solution is due independently to B. Sz.-Nagy and C. Foias [15] and to L. de Branges and J. Ball and N. Cohen [4]. Such a linear system is essentially uniquely determined by its transfer function. The de Branges-Rovnyak construction makes use of the theory of square summable power series with coefficients in a Hilbert space. The construction also applies when the coefficient space is a Krein space [7].

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Lyman alpha radiative transfer at the epoch of cosmic reionization

  • Kim, Hyo Jeong;Park, Hyunbae;Ahn, Kyungjin
    • 천문학회보
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    • 제42권2호
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    • pp.55.2-55.2
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    • 2017
  • We present a numerical code for the random scattering histories of Lyman alpha photons in the intergalactic medium. The numerical code calculates the radiative transfer under generic three dimensional density, ionization fraction, and peculiar velocity fields based on N-body + radiation transfer simulations of the epoch of reionization. The code is tested with models having analytical solutions, which have idealized geometry and simplified velocity fields. The emergent line profiles can give constraints to the ionization structure around Lyman alpha sources in the early universe.

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풋거름 보리-헤어리베치 혼파 작부체계에서 몰리브덴 시용이 질소 고정, 이동 및 수량에 미치는 영향 (Application of Molybdenum Enhances Nitrogen Fixation and Transfer, and Biomass Production under a Hairy Vetch/Barley Mixture Cropping System)

  • 김태영;김송엽;윤영은;김장환;이용복
    • 한국환경농학회지
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    • 제38권4호
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    • pp.291-295
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    • 2019
  • 본 연구는 풋거름보리와 헤어리베치 혼파 작부체계에서 Mo 시용이 풋거름 작물의 수량, 헤어리베치의 공중질소 고정율 및 헤어리베치에서 풋거름보리로 질소 이동율에 대한 정량적 평가를 실시하였다. Mo 2.0 kg/ha 시용에서 풋거름 작물의 최대수량을 나타내었다. 그리고 풋거름 작물의 최대수량을 나타낸 Mo 2.0 kg/ha 처리에서 헤어리베치의 공중질소 고정율은 81.7% 이었으며, 이때 헤어리베치에서 풋거름 보리로 이동된 질소는 풋거름 보리 질소함량의 53.9% 이었다. 따라서, Mo 2.0 kg/ha 처리가 풋거름 보리-헤어리베치 혼파 작부체계에서 가장 적절한 수준으로 나타났다. 본 연구는 국내에서 보고되지 않았던 헤어리베치로부터 보리로의 질소 이동을 정량화하였다는 점에서 의미가 있는 것으로 판단된다.