• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.279-283
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• 2022

UV-vis spectroscopy is one of the powerful tools for measuring the concentrations of reactant and products during a chemical reaction. However, there is an limitation of using the technique when the reaction undergoes in high concentration and high temperature. Color analysis using camera images can provide the identical results with UV-vis analysis with regardless of the sample concentration and temperature. The catalytic reduction reaction of resazurin to resorufin was investigated using the color analysis with the color spaces such as CIE L^*a^*b^*. Moreover, the color analysis enabled the independent analysis of two different material's concentrations without the deconvolution of overlapped wavelengths unlike the case of using UV-vis spectroscopy.

• Conservation Science in Museum
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• v.14
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• pp.81-89
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• 2013

This study concerns UV-Vis spectrophotometry and 3D-fluorescence spectrophotometry analysis of textile parts of blue and green tones dyed with indigo of blue tone and turmeric, gardenia, goldthread and amur cork tree of yellow tone. In order to verify whether the kinds of textiles affected analysis result of each dye, silk and cotton textile samples were produced. According to the analysis of the degree of reflection of UV-Vis spectrophotometry, unique reflection spectrum of indigo appeared regardless of the kinds of textiles when they were dyed with indigo. As for textiles of green tone, the 3D-fluorescence spectroscopic analysis result showed that unique spectrums of yellow dyes, turmeric, goldthread and amur cork tree appeared regardless of the kinds of textiles but the fluorescence spectrums of gardenia and indigo did not appear.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.16 no.1
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• pp.25-31
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• 2006

Many amethysts of different origins such as South America, Aftrica, and Asia were compared. According to ICP-AES analysis, the colorizing elements were Fe, Cr, Cu, and Co. Amethysts from South America showed higher concentrations of the elements. UV- VIS analysis showed that both natural and synthetic amethysts were characterized by the higher absorption at 350 nm and 550 nm wavelength. The natural amethysts had lower permeability than that of the synthetic amethysts. According to FT-IR analysis, the synthetic amethysts were distinguished from the natural amethysts in that they had a typical absorption band of $3543cm^{-1}$. The amethyst from South America showed strong absorption bands of $3584cm^{-1}\;and\;3435cm^{-1}$, and African amethyst had absorption bands of $3299cm^{-1}\;and\;3196cm^{-1}$. $3381cm^{-1}$ absorption band was shown strongly for Asian origins.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.385-393
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• 2009

The spectroscopic characteristics of Madagascar tourmaline were investigated by UV-Vis and FTIR spectroscopy. Physical features were similar to other region's tourmalines. The green and blue samples showed strong absorption band in the 714~743 nm due to $Fe^{3+}$, pink samples showed strong absorption band in the 510~530 nm due to $Mn^{3+}$, brown samples showed strong absorption at 324 nm due to $Mn^{2+}-Ti^{4+}$ IVCT and the colorless samples only revealed weak absorption at 406~413 nm or no absorptions due to low quantity of Mn. Combination of the stretching and bending mode cationic hydroxyl units (metal-OH) are observed in the 4300~4500 $cm^{-1}$. The parallel tube-shaped inclusions which contain hematite were detected generally. This investigation revealed that Cu was not detected but Fe and Mn were detected in the Madagascar tourmalines, and the various colors appear according to the amount of those impurity elements.

• Analytical Science and Technology
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• v.13 no.2
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• pp.250-257
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• 2000

Paint, fiber and dye which play a critcal role in proving the relationship between a suspect and a victim or a crime scene, are one of the most frequently encountered trace evidences at a forensic laboratory, however, in usual, because of infinitesimally small sizes of forensic samples, investigation of the spectroscopic characteristics of such samples is becomming more and more prevalent in forensic science as a non-destructive method. In this study, transmittance/reflectance profiles at ultraviolet-visible region (240-780nm), were investigated by UV/visible microspectro- photometer and used to analyze the spectral characteristics of different types of 14 microfibers, 12 inks of four colors and 44 automotive paints of two colors. Good results for discrimination were given from spectra of these samples due to the characteristic bands in uv/vis region, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.29-36
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• 2010

The spectroscopic characteristics of synthetic and natural emeralds were investigated by UV-Vis and FTIR spectroscopy before and after heat treatment. The Mo and Co for synthetic flux and C1 for synthetic hydrothermal emeralds have been detected by X-ray fluorescence analysis. In the region of UV-Visible, the absorption of emerald from Colombia was generally increased after the heat treatment. The peak which related to C1 component in the $3000-2600cm^{-1}$ was shown in the hydrothermal synthetic emeralds by FTIR spectroscopy. The $2358cm^{-1}$ peak which originates from $CO_2$ was decreased after the heat treatment in the natural emerald. This was corresponded with the changes of gas element after heat treatment.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.445-445
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• 2013

유기태양전지는 간단한 제조공정, 낮은 제조단가, 가벼운 무게 및 우수한 유연성의 장점을 가지고 있기 때문에 모바일 기기의 응용에 많은 관심을 가지고 있다. 그러나 이종접합 유기태양전지의 광전 변환효율이 낮기 때문에 유기태양전지를 상용화하기 위해서는 광전변환 효율을 높이기 위한 연구가 필요하다. 본 연구에서는 태양전지의 광전 변환효율을 증진하기 위하여 열처리 시간 변화에 따른 이종접합 유기 태양전지의 특성에 미치는 효과를 조사하였다. 전자 주게 물질인 P3HT와 전자 받게 물질인 PCBM 물질을 특정용매에 녹여 패턴화된 ITO를 코팅한 glass 기판 위에 스핀 코팅 방법을 이용하여 glass/ITO/PEDOT:PSS/P3HT:PCBM/Al 구조를 가진 이종접합 유기태양전지를 제작하였다. UV-Vis 분광학, X-선 광전자 분광학 및 원자힘 현미경 측정을 하여 제작한 소자의 광학적 및 구조적 특성을 분석하였다. 이종접합 유기태양전지의 우수한 광흡수율과 평탄한 표면을 가지는 최적화 조건을 열처리 시간에 따라 비교 분석하였다. 제작한 소자들을 열처리를 하지 않은 소자와 다양한 시간 동안 열처리를 한 소자의 특성을 비교하였다. 제작한 이종접합 태양전지의 전류-전압 측정 결과를 분석하여 최대의 광전 변환효율을 가지는 최적의 열처리 조건을 결정하였다. 열처리를 할 경우 열처리를 하지 않은 소자보다 광전 변환효율이 증가함을 알 수 있었다.

• Analytical Science and Technology
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• v.15 no.1
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• pp.72-79
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• 2002

Di-(2-ethylhexyl)phthalate (DEHP) may be released from plasticized poly(vinyl chloride) (PVC) articles. In the cases of various methods for the quantitative analysis of migrating DEHP, there are much differences in migrating quantity according to the experimental methods. It is therefore important to make the comparison and analysis between these two results. A study of DEHP migration from blood and infusion bags has been carried out in different methods to evaluate the amount of DEHP migration using gas chromatograph and UV-vis spectrophotometry. Five PVC bags were cut into plane sheets in size of $40{\times}10{\times}0.4mm$, then were immersed in extraction solvent for an hour to release DEHP. It was determined by a gas chromatograph that $23.2{\sim}70.9{\mu}g/mL$ of DEHP was extracted. While extraction solvent was injected into PVC bags which were then placed for an hour to leach DEHP out. It was checked by a UV-vis spectrophotometer that the concentration of DEHP in extraction solvent was $24.8{\sim}41.3{\mu}g/mL$. Two results show different values according to the extraction conditions and experimental methods and the gas chromatographic results were converted into UV-vis spectroscopic results on condition that DEHP would be extracted equally per unit time and unit contact area. It was concluded that DEHP migrating amounts are approximately equal in two analytical methods.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1505-1506
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• 2011

염료감응형 태양전지(Dye-Sensitized Solar Cell, DSSC)의 FTO 표면에 compact layer를 형성시켜 직접적인 마찰에 의한 전자의 재결합을 줄일 수 있다. 따라서 광전극에서의 compact layer의 효과를 최대화하기 위하여 $TiCl_4$ 용액에 acetic acid를 첨가하여 특성변화를 측정하였다. UV-Vis 분광기, I-V 특성곡선, EIS 분석장비를 이용하여 검토한 결과, UV-Vis 분광분석을 통해서 acetic acid를 첨가한 compact layer의 투과도가 현저하게 높아진 것을 확인하였다. 이 결과는 $TiCl_4$ 처리에 의하여 compact layer를 구성하고 있는 $TiO_2$ 입자의 응집현상이 개선되므로 표면특성이 향상되었기 때문이다. Acetic acid를 첨가한 compact layer가 입자응집으로 인한 표면저항의 감소를 유발하여, 전자의 이동이 원활해진 것을 내부 임피던스 분석을 통하여 확인하였다. Compact layer에 의해 재결합이 감소하여 효율이 향상된 것을 I-V 특성곡선을 분석하여 확인하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.2
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• pp.167-175
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• 1993

Lithium-Carbon Intercalation Compounds(Li-CICs) have been synthesized from various carbon ma-terials by use of the modified stainless steel two-bulbs methods. These compounds had various colours by structural character of starting materials. The synthesized Li-CICs were identified to stage formation process by X-ray diffraction data. At these results, well-oriented natural graphite and graphite fiber are formed lower stages(Stage 1, Stage 2), but poor-oriented carbon fiber and petroleum cokes are also formed higher stages(Stage 3, Stage 4, Stage 5). And when we compared with measured d value and calculated d value, these values agreed with each other. But poor-oriented carbon materials are some difference from them. The stage stability and energy stage of Li-CICs were obtained by UV/VIS Spectrophotometric data. X-ray diffraction and UV/VIS Spectrophotometric data suggested that well-oriented carbon materials has distingushible curve between energy and reflectance. In these results, we know that many charge carriers between carbon layers are related to concentration of intercalants. And then, this paper also provides information on high efficiency energy storing materials at intercalation process of Li-CICs.