• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.7 no.2
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• pp.279-288
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• 1997

The penetrating speeds of organic solvents into the nude mouse skin were measured by in vitro methods(diffusion cell methods) and in vivo methods(measuring internal residues of the organic solvents). The results were as follows: 1. The penetrating speeds of toluene, m-xylene, MEK, MIBK, ethanol, IPA and 2-bromopropane into the skin were $0.4832mg/cm^2/h$, $0.1738mg/cm^2/h$, $1.124mg/cm^2/h$, $0.6627mg/cm^2/h$, $1.747mg/cm^2/h$, $1.359mg/cm^2/h$, and 2-bromopropane $4.165mg/cm^2/h$ respectively. 2. The penetrating speeds of the mixtures of two, toluene and m-xylene, the mixture of three, IPA, ethyl acetate, and MIBK, the mixture of five, toluene, m-xylene, IPA, ethyl acetate, and MIBK were $0.172mg/cm^2/h$, $1.431mg/cm^2/h$, and $2.983mg/cm^2/h$ respectively. 3. The absorption speeds of 2-bromopropane and styrene which were measured by in vivo processes were $3.12mg/cm^2/h$ and $1.44mg/cm^2/h$ respectively. The absorption speed of 2-bromopropane mesured in vivo was 74.9% of that measured by in vitro methods, $4.165mg/cm^2/h$.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.3
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• pp.43-56
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• 2024

In this study, we investigate wet absorption process and the performance and regeneration of Fe(II)EDTA^2- absorbents, electrodeposition of the reducing agent for recovery of metal powder and re-absorption performance using regenerated absorbed for the simultaneous removal of nitrogen oxides (NO) and sulfur oxides (SO₂) emitted from flue gas. As a result of a simultaneous absorption experiment of NO and SO₂ under the presence of oxygen, the antagonistic effects of SO₂ and O₂ in the absorption solution resulted in the regeneration of Fe(III)EDTA^- and Fe(II)EDTA-NO^2- to Fe(II)EDTA^2-, inducing the maintained neutral pH and maintained NO₂ absorption, thereby greatly improving the simultaneous absorption performance of NO and SO₂. In addition, after regenerating the Fe(II)EDTA^2- absorbent with Zn metal powder as a reducing agent, electrodeposition was performed to recover the remaining reducing agent. During the electrodeposition process, the high Zn recovery efficiency (approximately 57.50%) was observed at an applied voltage of 4 V, and the total absorption amount of NO was also significantly improved.

• Bulletin of the Korean Chemical Society
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• v.26 no.3
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• pp.428-432
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• 2005

Squarylium or squaraine dyes are derived from 1,2-dihydroxycyclobuten-3,4-dione, otherwise known as squaric acids. They are two principal types: the 1,2-bisdonorsubstituted derivatives, and the 1,3-bisdonorsubstituted derivatives. The former are essentially merocyanines and have no distinctive properties, whereas the latter represent a unique type of chromophore, which is neither a merocyanines nor cyanine and has exceptional light absorption characteristics. They also have many functional applications based on their special properties. Thus it was the objective of this research project to synthesize a range of 1,3-squarylium dyes of widely differing structural types, and to investigate their light absorption and fluorescence properties in general, and the color change properties of appropriate examples in particular. Also in this study, the various pHinduced colour change processes were examined.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.3
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• pp.183-188
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• 2001

The deposition behavior and photoelectric response characteristics of chlorophyll a(Chl a) monolayers and multilayers were investigated under various film fabrication conditions. Chl a LB films were deposited onto quartz and pretreated ITO glass substrates under several fabrication conditions, including surface pressure and number of layers. The absorption spectra of Chl a in a solution state and solid-like state (LB films) were fairly consistent with each other, and two absorption peaks were found at 678 and 438nm, respectively. The prepared Chl a LB films were set into an electrochemistry cell equipped with a Pt plate as the counter electrode, and the photoelectric response characteristics were obtained and analyzed relative to the light illumination. By considering the resulting photocurrents, the optimal fabrication conditions for Chl a LB films were determined as 20mN/m of surface pressure and 20 layers. The action spectrum of the Chl a LB films was obtained in the visible region, and was found to be in good agreement with the absorption spectrum. The possible application of the proposed system as a constituent of an artificial color recognition device was suggested based on combining with the photoelectric conversion property of another light-sensitive biological pigment.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2089-2092
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• 2007

Tantalum-containing metal oxides, well known for their efficiency in water splitting and H2 production, have never been used in visible light driven photodecomposition of H2S and H2 production. The present work is an attempt in this direction and investigates their efficiency. A mixed metal oxide, ZnFe2Ta2O9, with the inclusion of Fe2O3 to impart color, was prepared by the conventional ceramic route in single- and double-calcinations (represented as ZnFe2Ta2O9-SC and ZnFe2Ta2O9-DC respectively). The XRD characterization shows that both have identical patterns and reveals tetragonal structure to a major extent and a minor contribution of orthorhombic crystalline system. The UV-visible diffuse reflection spectra demonstrate the intense, coherent and wide absorption of visible light by both the catalysts, with absorption edge at 650 nm, giving rise to a band gap of 1.9 eV. Between the two catalysts, however, ZnFe2Ta2O9-DC has greater absorption in almost the entire wavelength region, which accounts for its strong brown coloration than ZnFe2Ta2O9-SC when viewed by the naked eye. In photocatalysis, both catalysts decompose H2S under visible light irradiation (λ ≥ 420 nm) and produce solar H2 at a much higher rate than previously reported catalysts. Nevertheless, ZnFe2Ta2O9-DC distinguishes itself from ZnFe2Ta2O9-SC by exhibiting a higher efficiency because of its greater light absorption. Altogether, the tantalum-containing mixed metal oxide proves its efficient catalytic role in H2S decomposition and H2 production process also.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.943-946
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• 2011

The electronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine (CuPc) layer deposited on chloro[subphthalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, with various thicknesses were investigated using ultraviolet (UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in the UV-visible region that were consistent with the fitted spectra following simple linear combination of the single layer absorption spectra of the two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For the CuPc/SubPc structures, surface morphology was characterized by elongated grains, which are characteristic of SubPc thin films, indicating that the morphological influence of the underlying CuPc layer on the subsequent SubPc layer was not large. For the SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of the CuPc layer varied according to the thickness of the underlying SubPc layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05c
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• pp.3-7
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• 2004

$HgGa_2S_4:CO^{2+}$ single crystal were grown by the chemical transport reaction(CTR) method. 1n the optical absorption spectrum of the $HgGa_2S_4:CO^{2+}$ single crystal measured at 298K, three groups of impurity optical absorption peaks consisting of three peaks, respectively, were observed at 673nm, 734nm, and 760nm, 1621nm, 1654nm, and 1734nm, and 2544nm, 2650nm, and 2678nm. At 10K, the three peaks(673nm, 734nm, and 760nm) of the first group were split to be twelve peaks. These impurity optical absorption peaks are assigned to be due to the electronic transitions between the split energy levels of $Co^{2+}$ sited in the $S_4$ symmetry point.

• Bulletin of the Korean Chemical Society
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• v.34 no.2
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• pp.515-518
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• 2013

We present synthesis of a new kind of organic-inorganic hybrid polymer, poly xylene-hexamethyltrisiloxane hybrid (PXS) by a new synthetic way from o-xylene and 1,1,3,3,5,5-hexamethyltrisiloxane. The merged molecular structure of the two monomeric components for the PXS polymer was confirmed by $^{13}C$- and $^1H$-NMR, and FT-IR. Its optical absorption and emission properties were investigated by UV-vis absorption and photoluminescence (PL) spectroscopy. The PXS exhibits absorption at 265 nm which is the same with the o-xylene but tailing up to nearly 400 nm, which is maybe related the polymeric structure of the PXS. For the PL investigation, the PXS shows red-shift of the peak from 288 nm (o-xylene) to 372 nm in the case of excitation at 265 nm, at which both PXS and o-xylene have sufficiently high absorption for excitation. When 325-nm laser is used for excitation, the PXS shows a broader peak at 395 nm compared to the excitation at 265 nm and the o-xylene shows no luminescence probably due to the lack of absorption at 325 nm.

• Bulletin of the Korean Chemical Society
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• v.18 no.7
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• pp.743-749
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• 1997

Local structure refinement of the BaFe1-xSnxO3-y system (x=0.00-0.50) has been carried out with Fe K-edge x-ray absorpion spectroscopic studies. It is found out that the Fe ions are placed in two different symmetric sites such as tetrahedral and octahedral sites in the compounds by comparison with Fe K-edge x-ray absorption near edge structure (XANES) spectrum of the γ-Fe2O3 compound as a reference. Small absorption peaks of dipole-forbiden transitions appear at a pre-edge region of 7111 eV due to the existence of Fe ions in the tetrahedral and octahedral sites. The peak intensity decreases with the substitution amount of Sn ion. Three different absorption peaks of 1s→4p dipole-allowed transition appear on the energy region between 7123 and 7131 eV. The peaks correspond to 1s→4p main transition of Fe ions in tetrahedral and octahedral sites and 1s→4p transition followed by the shakedown process of ligand to metal charge transfer. The bond distances between Fe ions in the tetrahedral site and nearest neighboring oxygen atom (Fe-4O), and those in octahedral site (Fe-6O) are determined with the extended x-ray absorption fine structure (EXAFS) analysis. Two different interatomic distances increase with the substitution amount of Sn ion and also the bond lengths of Fe-4O are shorter than those of Fe-6O in all compounds.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1609-1612
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• 2007