• Title/Summary/Keyword: scattering media

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Radiative Heat Transfer in Radiatively Particpating Finite Cylindrical Media - Exact and P-N Solutions - (복사에 관여하는 유한 원통형 매질에서의 복사열 전달)

  • 서인수;손종관;임승욱;이준식
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.6
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    • pp.1428-1437
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    • 1988
  • An analysis of radiative heat transfer has been conducted on axisymmetric finite cylindrical media. It is assumed that the temperature in the media is uniformly distributed and the boundaries are diffusely emitting and reflecting at a constant temperature. The scattering phase function is represented by the delta-Eddington approximation to account for highly forward scattering by particulates just as in the combustion system. Exact numerical solutions are obtained by Gaussian quadrature method and compared with P-1 and P-3 approximation solutions to verify their engineering application limit. The effects of optical thickness, scattering albedo, wall emissivity and aspect ratio are investigated. The results show that P-3 approximation is found to be in good agreement with the exact solution.

Studies on the Wave Propagation and Fluctuation in Randomly Ditribution Media of L-Aspartic Acid (L-Aspartic Acid의 무질서하게 분포된 매질에서 파동전개와 변동에 관한 연구)

  • Kim, Ki-Jun;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.1
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    • pp.122-128
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    • 2012
  • The influences of fluorescence, scattering, and flocculation in turbid material by light scattering of L-aspartic acid, preservative and emulsifier were interpreted for the scattered fluorescence intensity and wavelength. They have been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF) and flocculation. The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used. When two particles approach each other, interactions of several colloid particles can come into play which may have major effect on the flocculation and LIF process. The values of scattering coefficient ${\mu}_s$ are large by means of the increasing scattering of scatterer, The values have been found that the slope decays exponentially as a function of concentration from laser source to detector by our experimental result. It may also aid in designing the best model for oil chemistry, bio-pharmaceutical products, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

A Study on the Measurements of Beam Wave Propagation and Fluorescence Spectroscopy in Particles Media (입자매질에서 빔파동전파와 형광분광 측정에 관한 연구)

  • Kim, Ki-Jun;Lee, Jou-Youb;Sung, Wan-Mo
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.2
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    • pp.167-175
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    • 2014
  • The influences of fluorescence, scattering, and flocculation in turbid material were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by the spectroscopy of laser induced fluorescence(LIF). The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used in Photodynamic therapy. The interactions of several colloid particles can come into play which have major effect on the flocculation and LIF process. We measured scattering and fluorescence spectra of the sample for in vitro as function of concentration from lase source to detector. The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer. Therefore, Phorphyrin A is larger than Phorphyrin C in scattering intensity ${\mu}_s$, but Phorphyrin A is smaller than Phorphyrin C in penetration depth ${\delta}$.

A Study on Wave Propagation and Scattering in Purple Membrane and β-carotene (Purple Membrane과 β-carotene에서 산란과 파동전파에 관한 연구)

  • Kim, Ki-Jun;Park, Tae-Sul;Sung, Wan-Mo
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.1
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    • pp.136-142
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    • 2016
  • The influences of fluorescence, scattering, and flocculation in random media were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by the spectroscopy of laser induced fluorescence(LIF). The effects of optical properties in scattering media have been found by the optical parameters(${\mu}_s$, ${\mu}_a$, ${\mu}_t$). Flocculation is an important step in many solid-liquid separation processes and is widely used in Photodynamic therapy. The interactions of several colloid particles can come into play which have major effect on the flocculation and LIF process. We measured scattering and fluorescence spectra of the sample in vitro as function of distance from lase source to detector. The value of scattering coefficient ${\mu}_s$ is and ${\beta}$-carotene were measured as larger values(I, ${\delta}$) by means of closer distance from source to detector.

Measurement on the Methotrexate in L-${\alpha}$-Phosphatidylcholine Media by Light Sacttering (L-${\alpha}$-Phosphatidylcholine 매질에서 빔산란에 의한 Methotrexate의 측정)

  • Kim, Ki-Jun;Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.2
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    • pp.251-257
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    • 2013
  • The influences of Methotrexate as fluorophor, scatterer, absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by laser induced fluorescence spectroscopy. It has been found that the effects of optical properties in scattering media by the optical parameters((${\mu}_s$, ${\mu}_a$, ${\mu}_t$). The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of L-${\alpha}$-Phosphatidylcholine, it has been found that the slope decays exponentially as a function of depth from laser source to detector. It may also aid in designing the best model for oil chemistry, laser medicine and application of medical engineering.

Verification on Diffusion of Beam Propagation in Randomly Distributed Scattering Medium (무질서하게 분포된 산란매질에서 빔전파의 확산에 관한 검증)

  • Kim, Ki-Jun;Lee, Hoo-Seol
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.4
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    • pp.354-361
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    • 2007
  • The distribution of light in a randomly scattering medium can represent problems found in many area. Particularly, in the clinical application of lasers for Photodynamic therapy(PDT) or in the fluorescence spectroscopy for biological tissue, turbidity plays a very important role. The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in scattering medium as tissue. It has been found that the effects of optical properties in scattering media could be investigated by the optical $parameters({\mu}_s$, ${\mu}_a$ ,${\mu}t)$. Experimental and Monte Carlo simulation method for modelling light transport in tissue was applied. The experimental results using a randomly distributed scattering medium were discussed and compared with those obtained through Monte Carlo simulation. It'll be also important in designing the best model for oil chemistry, medicine and application of medical engineering.

Evaluation of Molecular Structural Changes in Starch Depending on Amylose Content Using Dynamic Light Scattering (동적광산란법을 이용한 아밀로즈 함량에 따른 전분 분자 구조 변화 분석)

  • Moon, Ju-Hyeon;Ma, Jin-Gyeong;Kim, Jong-Yea
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.5
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    • pp.653-658
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    • 2017
  • To evaluate the effects of amylose content and dissolution media on the molecular structure of maize starch, changes in the hydrodynamic diameter of starch molecules were assessed via dynamic light scattering depending on amylose content and dissolution media. As the amylose content of starch increased, the hydrodynamic diameter of starch molecules proportionally decreased from 204 to 92 nm. To alter ionic strength, hydrogen bonding, or polarity of dissolution media, various contents of NaCl (1, 2, or 3 M), urea (1, 2, or 3 M), or 1-butanol (0.1, 0.5, or 1.0%) were added to media, respectively, resulting in increased hydrodynamic diameter of starch. However, the degree of expansion was dependent on amylose content and the concentration and/or type of additive. The hydrodynamic diameter of starch molecules exhibited significant correlation with amylose content obtained by size exclusion chromatography, regardless of dissolution conditions.

Measurement-based Face Rendering reflecting Positional Scattering Properties (위치별 산란특성을 반영한 측정기반 얼굴 렌더링)

  • Park, Sun-Yong;Oh, Kyoung-Su
    • Journal of Korea Game Society
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    • v.9 no.5
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    • pp.137-144
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    • 2009
  • This paper predicts 6 facial regions that may have sharply different scattering properties, rendering the face more realistically based on their diffusion profiles. The scattering properties are acquired in the form of high dynamic range by photographing the pattern formed around an unit ray incident on facial skin. The acquired data are fitted to a 'linear combination of Gaussian functions', which well approximates the original diffusion profile of skin and has good characteristics as the filter. During the process, to prevent its solutions from converging into local minima, we take advantage of the genetic algorithm to set up the initial value. Each Gaussian term is applied to the irradiance map as a filter, expressing subsurface scattering effect. In this paper, to efficiently handle the maximum 12 Gaussian filterings, we make use of the parallel capacity of CUDA.

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EM wave scattering by bianisotropically coated multilayer cylinder with an impedance sheet[II] (쌍이방성 매질 코팅 다층 원통에 의한 전자파 산란 해석[II])

  • 엄상진;윤중한;이화춘;곽경섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.4B
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    • pp.391-399
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    • 2001
  • In this paper, electromagnetic wave scattering from a bianisotropicaly coated cylinder is formulated by using wave functions for bianisotropic media and boundary-value method. The cross section of the cylinder is made of a conducting core, a lossless dielectric layer which is both electrically magnetically bianisotropic, and a bianisotropic impedance sheet and a different uniaxial bianisotrpic coating. The solutions to arbitrary polarization angles are presented in two-dimensional. This paper presents and exact solution to the problem of scattering by a long composite circular cylinder using the boundary method. The validity of this solution is verified by comparing numerical results with those in literature. The numerical results for various geometrical and electrical parameters on bistatic scattering cross-section are presented.

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