• Title/Summary/Keyword: Spectroscopy

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Corrosion Stability of Iron Artifacts after Treating with Water Treatment (수처리제를 사용한 철제유물의 부식 안정성 연구)

  • Jeong, Ji Hae
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.381-390
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    • 2017
  • Desalination is the main focus of the stabilization of iron artifacts. However, drawbacks such as re-corrosion are noted due to the uncertainty in the elimination of the corrosive factors and artifacts. Several studies have been carried out on the effects of corrosion inhibitors to overcome these shortcomings. In this study, the effects of type 3 water treatment on corrosion inhibitors were investigated. Surfaces of samples that contained film corrosion inhibitors on their surfaces were analyzed. The results revealed that the surface rust was removed from the sample of type 1 No. 2 that was mainly composed of phosphate. The average weight reduction rates of re-corrosion samples were 0.58, 0.03, and 0.07% for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The changes in the $Cl^-$ ion, a corrosive agent were found to be 28.60, -4.08, and -1.94 ppm for type 1 No. 2, type 2 No. 2, and type 3 No. 2 respectively. The water-treated films were analyzed by X-ray photoelectron spectroscopy (XPS). It was found that type 2 No. 2 had less Fe the basis metal, than that in type 3 No. 2 indicating much better film. Moreover, Si content was higher in type 2 No. 2, based on the silicate content, than in type 3 No. 2. They are speculated to be the reason or the formation of a better film. Type 1 No. 2, which is mainly composed of phosphate, would be inappropriate as a metal artifact conservation treatment. It was determined that type 2 No. 2 and type 3 No. 2 water treatments, which are mainly composed of silicate, provided excellent corrosion inhibiting effects. Corrosion inhibitors could be used as emergency treatment agents during the excavation of iron artifacts.

Scientific Investigation of the Clothes Collected at Comfort Station in Nara, Japan (일본 나라현 위안소 수습 의복 조사 및 과학적 분석)

  • Choi, Jung Eun;Jeon, Yu Ree;Lee, Yu Jin;Kim, Min Seo;Jin, Chul Min
    • Journal of Conservation Science
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    • v.33 no.5
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    • pp.363-370
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    • 2017
  • The aim of this study was to obtain information about two early-20th Century clothes, for which the "National Memorial Museum of Forced Mobilization under Japanese Occupation" has sought to receive preservation treatment. Optical microscopes and a scanning electron microscope were used to investigate the weaving of the clothes, and Fourier transform infrared spectroscopy(FT-IR) was used to investigate the fibers. Cloth A is believed to be a Japanese half sleeved inner wear(Hanjuban) used by women. Cloth B is believed to be working clothing that was checked by an Osaka plant. This was verified by a book written by the Japanese army. Both of the clothes were made mostly from cotton, although the inner wear also used viscose rayon on the neck collar. The button on the working wear was made of urea formaldehyde resin, an early precursor to plastic.

The Characterization of Spherical Particles in S/G Sludge (S/G 슬러지 중 구형입자의 특성측정)

  • Pyo Hyung-Yeal;Park Yang-Soon;Park Sun-Dal;Park Yong-Joon;Park Kyoung-Kyun
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2005.06a
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    • pp.129-136
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    • 2005
  • There should not be ion exchange resin particles in S/G sludge. The suspicious spherical resin particles observed in S/G sludge sample were characterized for particle size distribution under optical microscope using the micro-technique, for element analysis by the electron probe micro analysis (EPMA), and for molecular identification by the IR spectroscopy The particle sizes are distributed from 1 to 200 ${\mu}m$ for the sludge, while 40 to 500 ${\mu}m$ for the spherical resin particles. The results of the elemental analysis showed different major impurities: Si, Al, Mn, Cr, Ni, Zn and Ti for the sludge particles, while Si, Cu, Zn for the spherical resin particles. However, both particles contain Fe as a matrix of hematite ($Fe_{3}O_4$). IR spectrum of the spherical particles was quite different from that of ion exchange resins used in S/G system. These results indicate that the spherical particles are not related to ion exchange resin particles and formed by the process of the sludge formation.

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Chemical Structure of the Major Color Component from a Korean Pigmented Rice Variety (한국산 유색미에서 분리한 안토시아닌의 화학구조)

  • Cho, Man-Ho;Paik, Young-Sook;Yoon, Hye-Hyun;Hahn, Tae-Ryong
    • Applied Biological Chemistry
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    • v.39 no.4
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    • pp.304-308
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    • 1996
  • The major color component of a Korean pigmented rice (Oeyza sativa var. Suwon 415) was purified with Amberlite XAD-7 column and preparative paper chromatography. The purified pigment was determined as anthocyanin by paper chromatography, UV/Vis and NMR spectroscopy. The $\lambda_{max}$ of the Purified anthocyanin on UV/Vis spectrum were 529 nm and 281 nm. The $A_{440}/A_{529}$ value of the purified anthocyanin was 23% suggesting the presence of 3-glycosidic structure. The aglycone from acid hydrolysis showed bathochromic shift (18 nm) in the presence of $AlCl_3$ indicating that the anthocyanidin contained free adjacent hydroxyl groups such as cyanidin, delphinidin, petunidin or luteolinidin. The sugar moiety obtained from acid hydrolysis was determined as glucose by paper chromatography. The NMR spectra showed that the aglycone was cyanidin and the sugar was ${\beta}-D-glucopyranose$. Thus, the chemical structure of the purified anthocyanin was identified as cyanidin $3-O-{\beta}-D-glucopyranoside$.

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Measurement of Surface Color and Fermentation Degree in Tea Products Using NIRS (근적외선 분광광도계를 이용한 차제품의 표면 색상 및 발효정도 측정)

  • Chun, Jong-Un
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.54 no.1
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    • pp.55-60
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    • 2009
  • This study was conducted to measure tea surface colors using the visible bands ($400{\sim}700$ nm) with near-infrared spectroscopy (NIRS). The surface colors of 117 tea products were measured with a colorimeter. The $a^*/b^*$ (CIE color scale) or a/b (Hunter color scale) ratios in different tea products accounted for about 99.7% of the variation in fermentation degree (FD), indicating that the $a^*/b^*$ (a/b) ratio is a very useful trait for assessing fermentation degree. Also tea powders were scanned in the visible bands used with NIRS. Calibration equations for surface colors and fermentation degree were developed using the regression method of modified partial least-squares (MPLS) with internal cross validation. The equations had low SECV (standard errors of cross-validation), and high $R^2$ (coefficient of determination in calibration) values with $0.779{\sim}0.999$, indicating that the whole bands ($400{\sim}2500\;nm$) with NIRS could be used to rapidly measure traits related to surface color, fermentation degree and other chemical components in tea products with high precision and ease at a time.

A Quantitative Study for Hydrothermal Alteration Zones using Short Wavelength Infrared Spectrometry (단파장적외선 분광분석법을 이용한 열수변질대 정량화 연구)

  • Kim, Yong-Hwi;Choi, Seon-Gyu;Ko, Kwang-Beom;Han, Kyeong-Soo;Koo, Min-Ho
    • Economic and Environmental Geology
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    • v.50 no.1
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    • pp.15-26
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    • 2017
  • Advanced argillic, argillic, and phyllic zones are the most important alteration patterns to predict the hidden ore body during exploration of hydrothermal deposits. We examined the quantitative relationship between the spectral absorption characteristics and the mineral content of the synthetic mixtures such as alunite-kaolinite and illite-kaolinite using short wavelength infrared (SWIR) spectroscopy. In the alunite-kaolinite mixtures, the spectral absorption characteristics of the alunite was highly correlated with the Hull quotient reflectance(0.99) and the kaolinite had the highest correlation with the Gaussian peak(0.92). Illite-kaolinite mixtures are essential for Gaussian deconvolution because of the overlap of absorption region. Illite and kaolinite mixtures indicate the high correlation of 0.93 and 0.98, respectively. The error ranges in the alunite-kaolinite(8%) and illite-kaolinite mixtures(5%) derived from SWIR were smaller than the ones(29% and 26%) obtained from X-ray diffraction(Rietveld) analysis. These results show that SWIR spectroscopic analysis is more reliable than XRD Rietveld analysis in terms of quantification of allowed minerals.

Characteristics of Adhesive Disks in Parthenocissus tricuspidata during Attachment (착생에 따른 담쟁이덩굴 흡착근의 부착 특성)

  • Lee, Myung-Hui;Kim, In-Sun
    • Applied Microscopy
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    • v.41 no.2
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    • pp.139-145
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    • 2011
  • Parthenocissus tricuspidata is an epiphyte that lacks a main axial stem, but develops adhesive disks along the stem for climbing support. In this study, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were utilized to examine the brick wall surface and the adhesive disks of P. tricuspidata that attached to the surface successfully. The study was mainly focused the outermost layers of both structures before and after adhesion to find out whether there has been some structural and/or physical interactions between the two. The adhesive disks adhered firmly to the brick wall by secreting adhesive materials that help them for a tight attachment to the surface. The rough wall surface appeared facilitating better attachment of the adhesive disks by infiltrating the materials into those spaces leading to some degree of interactions at the interface. EDS analysis on the outermost layers of the adhesive disks that were separated from the substrates was also consistent with the SEM data on the interaction between the adhesive disks and the substrate surface. EDS analysis of the brick wall surface and the adhesive disks demonstrated similar elements of O, Si, Fe, Al, K, Mg, and Na in their components.

Oxidative Stability of the Pine Needle Extracted Oils and Sensory Evaluation of Savored Laver Made by Extracted Oils (솔잎추출유의 산화 안정성 및 추출유를 이용한 맛김의 관능적 평가)

  • Chung, Hae-Kyung;Choe, Chang-Suk;Lee, Ji-Hyun;Chang, Moon-Jeong;Kang, Myung-Hwa
    • Journal of the Korean Society of Food Culture
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    • v.18 no.2
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    • pp.89-95
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    • 2003
  • In order to evaluate the oxidative stability and sensory evaluation for the pine needle extracted oils, we prepared the pine needle extracted oils by the autoclave method with soybean and/or olive oils. The lipid peroxidation was monitored by measuring the formation of 2-thiobarbituric acid reactive substances(TBARS). In addition, the secondary reaction products of lipid oxidation were measured by fluorescence spectroscopy. A weight changing was decreased in oils added pine needle during storage periods. The formation of TBARS was the lowest in olive pine needle oils after 14 days storage, whereas it was the highest in soybean oil. The levels of fluorescent products in extracted oils added pine needle were also decreased in organic layers. According to the sensory evaluation, the scores of fragrance, taste and overall preference in savored laver using an pine needle extracted oils were no significant differences. Overall results suggest that the pine needle extracted oils can be developed to functional oil resources.

Properties of Capacity on Carbon Electrode in EC : MA Electrolyte II. Effect of Additives on Initial Irreversible Capacity (EC : MA 혼합전해질에서 카본 전극의 용량 특성 II. 초기 비가역 용량에 대한 첨가제의 효과)

  • Park, Dong-Won;Kim, Woo-Seong;Son, Dong-Un;Choi, Yong-Kook
    • Applied Chemistry for Engineering
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    • v.17 no.6
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    • pp.575-579
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    • 2006
  • Solid electrolyte interface is formed on a carbon electrode used as an anode in Li-ion battery, which can be of $Li^{+}$ intercalation/deintercalation during the first cycle. The passivation film formed by a solvent decomposition during the initial charge process affects cell performance and it was one of the main reason of an initial irreversible capacity. This paper describes the use, for the first time, of $Li_2CO_3$ as the additive for the formation of a passivation film on the carbon surface to suppress the initial irreversible reaction. Chronopotentiometry, cyclic voltammetry, and impedance spectroscopy were used to investigate the effects of the $Li_{2}CO_{3}$ additive. Scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction were also used to monitor changes in the surface morphology and composition of the passivation film formed by solvent decomposition and the precipitation of $Li_{2}CO_{3}$. The addition of $Li_{2}CO_{3}$ to a solution of 1 M $LiPF_{6}$/EC:MA (1:3, v/v) resulted in a decrease in the initial irreversible capacity and it was due to the suppression of the solvent decomposition on the electrode surface.

Fabrication and Photocatalytic Properties of SiO2-TiO2 Composite Nanofibers (SiO2-TiO2계 복합 나노섬유의 제조 및 광활성 연구)

  • Hyun, Dong Ho;Lim, Tae-Ho;Lee, Sung Wook
    • Applied Chemistry for Engineering
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    • v.19 no.5
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    • pp.554-558
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    • 2008
  • $(1-x)SiO_2-(x)TiO_2$ composite fibers with various compositions of $TiO_2$ were prepared by electrospinning their sol-gel precursors of titanium (IV) iso-propoxide (TiP), and tetraethyl orthosilicate (TEOS). The surface morphology and structure of sintered composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), simultaneous thermogravimetric analysis-differential scanning calorimetry (TGA-DSC) and Fourier transform infrared spectroscopy (FT-IR). As the content of $TiO_2$ in $(1-x)SiO_2-(x)TiO_2$ system was increased the average diameter of composite fibers was proportionally increased. Also, the transformation of $TiO_2$ from anatase to rutile form was inhibited by the highly dispersed $TiO_2$ around $SiO_2$ particles up to $0.6SiO_2-0.4TiO_2$ composite fibers even after calcination at $1000^{\circ}C$. The photocatalytic activity of $SiO_2-TiO_2$ composite fibers was examined for the methylene blue (MB) decomposition which was confirmed using UV-vis/DRS spectra. The experiments demonstrated that the MB in aqueous solution was successfully photodegraded using $SiO_2-TiO_2$ composite nanofibers under UV-visible light irradiation.