• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.223-225
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• 2008

하이드레이트는 저온.고압에서 저분자량의 게스트(guest)가 호스트(host)인 물분자 속에 포획되어 만들어지는데 일련의 과정은 물리적 반응을 통해 생성된다.본 연구에서는$CO_2$보다 지구온난화지수(Global Warming Potential)가 23,900배 높은 $SF_6$의 회수 및 정제기술로써 하이드레이트화를 이용하는 신기술 개발의 일환으로 분광학적 접근을 통해 $SF_6$ 혼합 하이드레이트의 정성 및 정량분석을 수행하였다. Raman Shift 분석 결과 $SF_6$의 $770cm^{-1}$에서 $v_1$ 진동주파수를 확인함으로써 하이드레이트 내 $SF_6$가 안정적으로 포집됨을 확인하였고 혼합가스 내 $SF_6$ 농도별로 만들어진 샘플의 Raman Shift를 통해서 $SF_6$의 하이드레이트 전환율을 가늠할 수 있었다.

• 방사성폐기물학회지
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• 제20권2호
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• pp.161-170
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• 2022

The effect of oxidation time on the characteristics and mechanical properties of spent nuclear fuel cladding was investigated using Raman spectroscopy, tube rupture test, and tensile test. As oxidation time increased, the Raman peak associated with the tetragonal zirconium oxide phase diminished and merged with the Raman peak associated with the monoclinic zirconium oxide phase near 333 cm^-1. Additionally, the other tetragonal zirconium oxide phase peak at 380 cm^-1 decreased after 100 d of oxidation, whereas the zirconium monoclinic oxide peak became the dominant peak. The oxidation time had no effect on the tube rupture pressure of the oxidized zirconium alloy tube. However, the yield and tensile stresses of the oxidized nuclear fuel cladding tube decreased after 100 d of oxidation. The results of the scanning electron microscopy and transmission electron microscopy were represented with the in-situ Raman analysis result for the oxide characteristics generated on the cladding of spent nuclear fuel.

• Bulletin of the Korean Chemical Society
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• 제23권10호
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• pp.1404-1408
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• 2002

The resonance Raman spectra of trans-polyacetylene films doped heavily with electron donor (Na) and acceptor (HClO4) have been measured with excitation wavelengths between 488- and 1320-nm, and the relationships between the Raman excitation photon energies (2.54-0.94 eV) and its wavenumbers were discussed. We found the linear dependence of the Raman shifts with the exchanges of excitation photon energies. In particular, the Raman wavenumbers in the C=C stretching $(V_1$ band) showed a dramatic decrease with the increase in Raman excitation photon energies. In the case of acceptor doping, its change is larger than that of donor doping. The observed wavenumber (1255-1267 $cm^{-1}$) of the $V_2$ band (CC stretch) of Na-doped form is lower than that of the corresponding band (1290-1292 $cm^{-1}$) of its pristine trans-polyacetylene, whereas the contrary is the case for the HClO4 doped form (1295-1300 $cm^{-1}$). The origin of doping-induced Raman bands is discussed in terms of negative and positive polarons.

• 복식
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• 제58권5호
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• pp.211-231
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• 2008

To conserve historic textiles, analyses of textile materials, pollutants and deterioration are prerequisite steps. Based upon analytical results, guides for conservation of historic textiles are established. In analyses of textile materials, pollutants and deterioration, there are chemical methods(burning, solubility and staining), physical methods(microscopy and density) and instrumental analysis(Fourier Transform Infrared Spectroscopy (FT-IR), Fourier Transform Raman Spectroscopy(FT-Raman), Gas Chromatography(GC), Mass Spectroscopy(MS), X-Ray Fluorescence (EDXRF, WDXRF), Energy Dispersive Spectroscopy(EDS), and X-Ray Diffraction(XRD), Tensile Testing Machine etc.). Combination of qualitative and quantitative analyses makes accurate diagnosis of textile condition possible. As examples of analyses and conservation of historic textiles, Chuninsan(19 century) similar to sunshade with handing down historic textile and golden decorative skirt(17 century) with excavated costume are taken.

• 광학과기술
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• 제8권4호
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• pp.30-34
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• 2004

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.135-135
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• 1999

It is well known that Raman spectroscopy is powerful tool in analysis of sp3/sp3 bonding fraction in diamond-like carbon(DLC) films. Raman spectra of DLC film is composed of D-peak centered at 1350cm-1 and G-peak centered at 1530cm-1. The sp3/sp3 fraction is qualitatively acquired by deconvolution method. However, in case of DLC film, it is generally observed that G-peak position shifts toward low wavenumber as th sp3 fraction increases. However, opposite results were frequently observed in ta-C films. ta-C film has much higher residual compressive stress due to its high sp3 fraction compared to the DLC films deposited by CVD method. Effect of residual stress on G-peak position is most recommendable parameter in Raman analysis of ta-C, due to its smallest fitting error among many parameters acquired by peak deconvolution of symmetric spectra. In current study, the effect of residual stress on Raman spectra was quantitatively evaluated by free-hang method. ta-C films of different residual stress were deposited on Si-wafer by modifying DC-bias voltage during deposition. The variation of the G-peak position along the etching depth were observed in the free-hangs of 20~30${\mu}{\textrm}{m}$ etching depth. Mathematical result based on Airy stress function, was compared with experimental results. The more reliable analysis excluding stress-induced shift was possible by elimination of the Raman shift due to residual compressiove stress.

• 미생물학회지
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• 제53권2호
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• pp.71-78
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• 2017

라만 분광법은 레이저가 분자의 공명에 의해 산란되는 특성을 이용하여 세포 내 지질, 핵산, 단백질 등의 구성물질을 신속하게 측정할 수 있어 단세포 수준의 세균 검측에 적합한 기술로 알려져 있다. 세포 구성물질에 대한 높은 특이성과 민감성 때문에 라만 스펙트라(spectra)만으로 일부 종 수준의 세균 계통분석이 가능하다. 또한 탄소-13, 수소-2 등의 동위원소를 동시에 사용하였을 경우 단세포의 생리적 활성 변화에 대한 정량평가에 활용 할 수 있다. 라만 분광법을 이용한 세균 검측 이후에도 광학핀셋과 미세유체칩과 연계하여 관심 있는 난배 양성 세균을 선택적으로 분리하거나 단세포 유전체 연구에 이용할 수 있을 정도로 응용 범위가 넓다. 본 총설에서는 라만 분광법을 활용한 미생물 분석 연구의 정확한 이해를 돕고자 기존의 연구를 중심으로 라만 분광법의 특성과 응용분야에 대해서 검토, 정리하였다.

• 전기학회논문지
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• 제66권7호
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• pp.1131-1140
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• 2017

This study is concerned with a design methodology of optimized fuzzy clustering-based neural network classifier for classifying black plastic. Since the amount of waste plastic is increased every year, the technique for recycling waste plastic is getting more attention. The proposed classifier is on a basis of architecture of radial basis function neural network. The hidden layer of the proposed classifier is composed to FCM clustering instead of activation functions, while connection weights are formed as the linear functions and their coefficients are estimated by the local least squares estimator (LLSE)-based learning. Because the raw dataset collected from Raman spectroscopy include high-dimensional variables over about three thousands, principal component analysis(PCA) is applied for the dimensional reduction. In addition, artificial bee colony(ABC), which is one of the evolutionary algorithm, is used in order to identify the architecture and parameters of the proposed network. In experiment, the proposed classifier sorts the three kinds of plastics which is the most largely discharged in the real world. The effectiveness of the proposed classifier is proved through a comparison of performance between dataset obtained from chemical analysis and entire dataset extracted directly from Raman spectroscopy.

• 보존과학회지
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• 제38권2호
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• pp.117-123
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• 2022

본 연구는 한국의 고대 유리에서 납바륨유리 3점, 납유리 3점, 포타쉬유리 10점 그리고 소다유리 10점을 중심으로 라만분광분석법을 이용하여 고대 유리의 융제 분류와 납유리에서 납의 정량 분석에 대한 가능성을 분석하였다. 분석 결과, 신축 진동 영역에서 납바륨유리가 1040 cm^-1, 납유리가 1000 cm^-1으로 라만 피크 에너지의 차이를 보이며 포타쉬유리와 소다유리는 굽힘 진동 영역에서 Na과 K 양이온의 차이에 따라 포타쉬유리는 490 cm^-1에서, 소다유리는 560 cm^-1에서 라만 피크의 차이를 보인다. 이외에 납유리는 PbO 함량에 따라 라만 스펙트럼의 적색 편이가 비례하므로 이를 통하여 납유리의 주성분인 PbO의 함량을 정량적으로 분석할 수 있다. 즉, 라만분광분석법으로 납바륨, 납, 포타쉬 그리고 소다유리에 대한 분류와 납유리에서 PbO 함량을 측정할 수 있는 가능성이 확인된다.

• 농업과학연구
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• 제46권1호
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• pp.183-194
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• 2019

Adulteration of argan oil with some other cheaper oils with similar chemical compositions has resulted in increasing demands for authenticity assurance and quality control. Fast and simple analytical techniques are thus needed for authenticity analysis of high-priced argan oil. Raman spectroscopy is a potent technique and has been extensively used for quality control and safety determination for food products In this study, Raman spectroscopy in combination with a net analyte signal (NAS)-based methodology, i.e., hybrid linear analysis method developed by Goicoechea and Olivieri in 1999 (HLA/GO), was used to predict the different concentrations of olive oil (0 - 20%) added to argan oil. Raman spectra of 90 samples were collected in a spectral range of $400-400cm^{-1}$, and calibration and validation sets were designed to evaluate the performance of the multivariate method. The results revealed a high coefficient of determination ($R^2$) value of 0.98 and a low root-mean-square error (RMSE) value of 0.41% for the calibration set, and an $R^2$ of 0.97 and RMSE of 0.36% for the validation set. Additionally, the figures of merit such as sensitivity, selectivity, limit of detection, and limit of quantification were used for further validation. The high $R^2$ and low RMSE values validate the detection ability and accuracy of the developed method and demonstrate its potential for quantitative determination of oil adulteration.