• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.358-359
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• 2001

PAHs는 불완전연소 과정과 주유소나 타르 생산공장 주변에서 발생하는데 돌연변이와 발암의 잠재력으로 인하여 특별한 관심이 요구되는 것들이고 US-EPA에서도 우선 오염물질로 선정되었다. PAHs를 검출하는 훌륭한 기술들이 존재하나, 이러한 기술들은 연속적인 모니터링이 요구되거나 많은 수의 샘플을 분석해야할 경우에 상당한 양의 비용과 시간이 요구된다. 그러나 분광학 기술을 바탕으로 한 Laser-Induced Fluorescence(LIF) spectroscopy를 이용한 방법은 실시간으로 연속적인 측정을 가능하게 할 뿐 아니라 여러 가지 PAHs, 유류오염물질 등의 물질을 동시에 측정할 수 있다. (중략)

• Journal of the Korean Applied Science and Technology
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• v.23 no.1
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• pp.70-76
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• 2006

The influence of fluorophor, scatterer, absorber in turbid materials by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it is studied the molecular property by laser induced fluorescence spectroscopy. It can be found that the effects of optical property are penentrated in scattering media by the optical $parameters({\mu}s$, ${\mu}a$, ${\mu}t$, ${\gamma}$, ${\rho})$. The value of scattering coefficient ${\mu}s$ is large appeared by means of the increasing particles of scattering, it can be found that the slope appears exponentially as a function of distance from laser source to detector. It may also utilize in designing the best model for oil chemistry, laser medicine and application of medical engineering.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.242-248
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• 1987

A sensitive, direct method for the determination of trace amounts of uranium in solution has been developed utilizing laser-induced fluorescence spectroscopy and a fluorescence enhancing reagent 'Fluran.' Standard addition technique is incorporated into the analysis to eliminate sample matrix effects. Analytical data show that a detection limit of 0.1 ppb (part per billion) uranium has been achieved and the precision of the analysis is in the range of 5% relative standard deviation. Results using the laser fluorescence method on many sets of unknown samples have been compared against corresponding values determined by other methods.

• Journal of the Korean Applied Science and Technology
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• v.23 no.4
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• pp.340-346
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• 2006

The influences of fluorescence, scattering, and flocculation in turbid material by light scattering 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. 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 value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, biopharmaceutical products, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.10
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• pp.3355-3360
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• 1996

To provide standard data of temperature and species concentration in a flame for calibrating the laser based combustion diagnostics, we investigated combustion characteristics of a flat flame burner(Mckennar Product). For various stoichiometric ratios we measured temperature and concentration of OH in the premixed methane/air flame with Coherent anti-Stokes Raman spectroscopy and laser induced fluorescence technique, respectively. Assuming the chemical equilibrium condition at the measured temperature, the mole fraction of the OH radical in the flame was obtained and compared with numerical analysis.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.98-99
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• 2012

Deposition of thin films using magnetron sputtering plasmas is a well-developed, classical technology. However, detailed investigations using advanced diagnostics are insufficient in magnetron sputtering, in comparison with plasma-aided dry etching and plasma-enhanced chemical vapor deposition. In this talk, we will show examples of diagnostic works on magnetron sputtering employing metal targets. Diagnostic methods which have fine spatial resolutions are suitable for magnetron sputtering plasmas since they have significant spatial distributions. We are using two-dimensional laser-induced fluorescence spectroscopy, in which the plasma space is illuminated by a tunable laser beam with a planer shape. A charge-coupled device camera with a gated image intensifier is used for taking the picture of the image of laser-induced fluorescence formed on the planer laser beam. The picture of laser-induced fluorescence directly represents the two-dimensional distribution of the atom density probed by the tunable laser beam, when an intense laser with a relatively wide line-width is used. When a weak laser beam with a relatively narrow linewidth is used, the laser-induced fluorescence represents the density distribution of atoms which feel the laser wavelength to be resonant via the Doppler shift corresponding to their velocities. In this case, we can obtain the velocity distribution function of atoms by scanning the wavelength of the laser beam around the line center.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1334-1336
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• 2001

In this study, laser ablation atomic fluorescence (LAAF) spectroscopy has been applied for a nanometer-scale surface analysis of Na-doped polymethyl methacrylate (PMMA). LAAF spectroscopy is a new sensitive element detection technique which involves atomizing of a sample by the laser ablation and detection of ablated plume by laser-induced fluorescence (LIF) spectroscopy. Using this technique in the detection of Na atoms with Na-doped PMMA, a detection limit is obtained as 36 fg for single laser shot. Further, the depth distribution in the sample is measured with a very high spatial resolution using a two-layer PMMA sample by observing the shot-by-shot LIF intensity from the Na atoms.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.385-387
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• 2007

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• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.329-335
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• 1999

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 phantom. It has been found that the effects of optical properties in scattering media could be investigated by the optical parameters(${\mu}_a$, ${\mu}_a$, ${\mu}_t$). Experimental and Monte Carlo Simulation method for modelling light transport in tissue was applied. The experimental results using a phantom were discussed and compared with those obtained through Monte Carlo Simulation. It may also aid in designing the best model for oil chemistry, medicine and application of medical engineering.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.72-78
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• 1993

The application of time-resolved laser induced fluorescence spectroscopy (TRLIF) to the complexation studies of Eu(III) and Cm(III) with humic substances is described. Using this method, three different spectroscopic characteristics(excitation spectra, emission spectra, and lifetimes) of these aquo ions and their complexes can be directly measured. By observing shifts in the wavelength and changes in the lifetime and intensities of the fluorescence emission, the information on the complexation behavior of humic substances with these trivalent metal cations in an aqueous solution, as well as energy transfer mechanisms, can be obtained. In addition, this method allows precise spectroscopic quantification of the complexation processes at very low concentrations of both components.