• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.6
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• pp.218-225
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• 1998

FTIR spectroscopy, useful technology for simultaneous and continuous measurement of the various components of the automotive exhaust gas, is utilized to investigate catalytic reaction charactristics of methane and a few unregulated exhaust emissions of NGV. Major findings are (1) catalytic reaction characteristics of methane measured in unsteady states of varying temperature are similar to those measured in steady states, (2) about 24 % of NO was oxidized to $NO_2$ as soon as they encounter catalysts, (3) study of formaldehyde suffers from difficulties in measurement due to the proximity in wavenumber of formaldehyde and methane, and requires an analyzer of higher resolution and accuracy than used in this study.

• Polymer(Korea)
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• v.28 no.6
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• pp.545-550
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• 2004

The refractive index of thin copolymer film was controlled by photo-degradation of chromophores in the copolymer. FTIR and UV/Vis spectroscopy were employed to elucidate the effect of chemical structure on refractive index changes after photobleaching. The decrease of refractive index of the film by photobleaching can be ascribed to the decrease of polarizability of polymer molecules through breakage of C =C bond in the chromophore. Due to the selective photoreaction of the chromophores which align along the film plane, refractive index of the copolymer film measured in TE mode decreases faster than that in TM mode. Polarized ATR-FTIR spectroscopy was used to verify such a difference in refractive index of the film.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.257-271
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• 2019

The use of food grade hexane (FGH) for edible oil extraction is responsible for the presence of benzene in the crude oil. Benzene is a Group 1 carcinogen and could pose a serious threat to the health of consumer. However, its detection still depends on classical methods using chromatography which requires a rapid non-destructive detection method. Hence, the aim of this study was to investigate the feasibility of using Fourier transform infrared (FTIR) spectroscopy combined with multivariate analysis to detect and quantify the benzene residue in edible oil (sesame and cottonseed oil). Oil samples were adulterated with varying quantities of benzene, and their FTIR spectra were acquired with an attenuated total reflectance (ATR) method. Optimal variables for a partial least-squares regression (PLSR) model were selected using the variable importance in projection (VIP) and the selectivity ratio (SR) methods. The developed PLS models with whole variables and the VIP- and SR-selected variables were validated against an independent data set which resulted in $R^2$ values of 0.95, 0.96, and 0.95 and standard error of prediction (SEP) values of 38.5, 33.7, and 41.7 mg/L, respectively. The proposed technique of FTIR combined with multivariate analysis and variable selection methods can detect benzene residuals in edible oils with the advantages of being fast and simple and thus, can replace the conventional methods used for the same purpose.

• Rapid Communication in Photoscience
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• v.4 no.3
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• pp.67-69
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• 2015

FTIR spectroscopy has been employed to investigate the variation of anion-water hydrogen bonding in 1-butyl 3-methyl imidazolium tetrafluoroborate ([Bmim][$BF_4$]) ionic liquid caused by addition of organic co-solvents with various polarities. The variation was estimated by probing band shape and intensity of the OH stretching vibration of trace water present in ionic liquid at $3400-3800cm^{-1}$. The presence of polar aprotic co-solvent in ionic liquid dramatically reduces the absorptivity of the OH stretch band, indicating that the co-solvent changes the nature of anion-water hydrogen bond drastically, which might be responsible for the reduction of the viscosity of ionic liquid in the presence of the co-solvent.

• Journal of Conservation Science
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• v.35 no.1
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• pp.11-18
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• 2019

The adhesives joining Buddhist scripture scrolls from medieval Korea(Goryeo Dynasty, A.D. 918~1392) are different from wheat starch adhesive. The composition of the adhesive was analyzed using Attenuated Total Reflectance-Fourier Transform Infrared(ATR-FTIR) spectroscopy. In the adhesive used to join Buddhist scripture scrolls, peaks attributed to amide I and amide II of the protein and carbohydrate were detected in the ATR-FTIR spectra, and no carbonyl peak($1745cm^{-1}$) for oil was detected in the 2nd derivative ATR-FTIR spectra. The ATR-FTIR spectra almost coincided with those of defatted soybean powder adhesive. Hence, the adhesives joining Buddhist scripture scrolls were inferred to be soybean adhesive prepared from a defatted soybean cake.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.463-464
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• 2006

• Advances in environmental research
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• v.9 no.3
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• pp.215-232
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• 2020

Crude oils are essential source of energy. It is majorly found in geographical locations beneath the earth's surface and crude oil is the main factor for the economic developments in the world. Natural crude oil contains unrefined petroleum composed of hydrocarbons of various molecular weights and it contains other organic materials like aromatic compounds, sulphur compounds, and many other organic compounds. These hydrocarbons are rapidly getting degraded by biosurfactant producing microorganisms. The present study deals with the isolation, purification, and characterization of biosurfactant producing microorganism from oil-contaminated soil. The ability of the microorganism producing biosurfactant was investigated by well diffusion method, drop collapse test, emulsification test, oil displacement activity, and blue agar plate method. The isolate obtained from the oil contaminated soil was identified as Bacillus subtilis. The identification was done by microscopic examinations and further characterization was done by Biochemical tests and 16SrRNA gene sequencing. Purification of the biosurfactant was performed by simple liquid-liquid extraction, and characterization of extracted biosurfactants was done using Fourier transform infrared spectroscopy (FTIR). The degradation of crude oil upon treatment with the partially purified biosurfactant was analyzed by FTIR spectroscopy and Gas-chromatography mass spectroscopy (GC-MS).

• Journal of Dental Rehabilitation and Applied Science
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• v.26 no.4
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• pp.447-453
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• 2010

The purpose of this study was to compare the light transmitting ability of halogen light in different colors and thicknesses. A1, A2, A3 colors of Z-250 composite resin(3M ESPE, St. Paul, U.S.A.) were used. Degree of conversion of separated resin specimens under the 2, 3, 4mm thickness resin were measured by FTIR spectroscopy. The result shows that decrease of degree of conversion by increase of resin thickness and decrease of degree of conversion by decrease of lightness of color. Within the limitation of results, it is recommended to use more light color of composite resin in small thickness to improve degree of conversion when use halogen light.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.177-180
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• 2006

Inter-fiber bonding is improved by refining resulting in higher Young's modulus. This effect is consistent to the changes of FTIR absorption intensities associated with the hydroxyl groups in the pulp samples. A PLS model, which is established to correlate the FTIR spectral data with the Young's modulus of the pulp samples for predicting the elastic Young's modulus of paper, is statistically robust.

• Journal of Photoscience
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• v.9 no.2
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• pp.376-378
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• 2002

Role of cl$^{[-10]}$ in photosynthetic oxygen-evolving complex was studied by light-induced Fourier transform infrared (FTIR) spectroscopy. cl$^{[-10]}$ depletion resulted in the suppression of amide I and amide II IR modes upon S$_1$ to S$_2$ transition. Br$^{[-10]}$ , 1$^{[-10]}$ and N0$_3$$^{[-10]}$ substituted FTIR difference spectra were very similar to that in cl$^{[-10]}$ reconstitution. F$^{[-10]}$ and $CH_3$COO$^{[-10]}$ substituted spectra were largely distorted. We succeeded in detecting the structural change of N0$_3$ $^{[-10]}$ in the cl$^{[-10]}$ site upon the S$_1$ to S$_2$ transition from $^{14}$ N0$_3$$^{[-10]}$ /$^{15}$ N0$_3$$^{[-10]}$ difference spectrum.