• Textile Coloration and Finishing
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• v.7 no.2
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• pp.47-54
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• 1995

Safflower is natural red dye largely used for dyeing on cotton. It contains yellowish safflower yellow and reddish carthamin, whose constitution is known. Safflower yellow is water-soluble dye and carthamin is solved in alkaline condition. Carthamon obtained by adding acidic solution to a carthamin shows the original hue of safflower. In present study, the dyeing behavior of natural dye known as safflower are examined in an aqueous acidic medium by use of the different dyeing methods such as traditional, modern and purifide-powder method. The relationship between the dye-uptake of cotton fabric investigated by the three methods and the various dyeing conditions is discussed.

• Journal of the Korean Chemical Society
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• v.11 no.4
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• pp.173-178
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• 1967

The rearrangement of ${\beta}$-4-nitroazoxybenzene into 4-hydroxy-4'-nitroazobenzene in strongly acidic solutions has been as certained by UV spectrophotometry. The kinetics of the rearrangement in 20 vol. % ethanol and 80 vol. % of aqueous sulfuric acid-water solutions has been studied, and the rearrangement was found to be acid catalyzed pseudo-frst-order reaction. The mechanism of the rearrangement is also discussed.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2973-2979
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• 2010

The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.

• Bulletin of the Korean Chemical Society
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• v.16 no.1
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• pp.42-47
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• 1995

Interpolymer complex formation between basic polypeptide poly(L-proline) Form Ⅱ (PLP(Ⅱ)) and acidic polypeptides poly(L-glutamic acid) (PLGA) and poly(L-aspartic acid)(PLAA) has been studied in water-methanol (1:2 v/v) mixed-solvent by viscometry, potentiometry, light scattering and circular dichroism (CD) measurements. It has been found that polymer complexes between PLP(Ⅱ) and PLGA (or PLAA) are formed via hydrogen bonding with a stoichiometric ratio of PLP(Ⅱ)/PLGA (or PLAA)=1:2 (in unit mole ratio) and that PLP(Ⅱ) forms polymer complex more favorably with PLGA than with PLAA. In addition, the minimum (for pH 5.0) and the maximum (for pH 3.2) in reduced viscosity of dilute PLP(Ⅱ)-PLGA mixed solutions are observed at 0.67 unit mole fraction of PLGA (i.e., [PLP(Ⅱ)]/[PLGA]=1/2). These findings could be explained in terms of molecular structure (or conformation) of the complementary polymers associated with the complex formation.

• Korean Journal of Remote Sensing
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• v.6 no.1
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• pp.49-62
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• 1990

The study is aimed to analize the spectral characteristics of igneous and sedimentary rocks in their reflectance curves obtained from CARY 17-D Spectrophotometer, and correlation between chemical complsition and HHRR data. The reflectance is higher in acidic igneous rocks, while lower in basic igneous rocks. Especially acidic plutonic rocks show sharp absorption bands at 1.4 and 1.9 $\mu\textrm{m}$ due to water inclusion in felsic minerals and basic rocks a broad absoption band near 1.mu.m due to Fe$^{++}$ ion in mafic minerals. Sandstones generally have higher reflectance than siltstones and shales, and show strong absorption at 1.4 and 1.9 $\mu\textrm{m}$. Arkosic sandstones have lower reflectance at blue band due to Fe$^{+++}$ ion exsolved from feldspars. The HHRR data have a positive correlation with SiO$_2$ and $K_2$O, while they have a negative correlation with FeO and MgO.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1665-1673
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• 2014

The objective of this study was to compare the compositions and immuno-enhancing effects of 6-year-old red ginseng powder (RGP) with those of its fractions. RGP was subjected to extraction with 100% ethanol to obtain an ethanol fraction (E) and residue 1 (R1). Then, R1 was subjected to extraction with distilled water to obtain water fraction (W) and residue 2 (R2). Chemical compositions were as follows: 4.94% acidic polysaccharides and 1.56% ginsenosides (amounts of Rg1, Re, Rf, Rg2, Rb1, Rc, Rd, and Rg3) in RGP, 0.11% acidic polysaccharides and 6.99% ginsenosides in E, 4.93% acidic polysaccharides and 0.40% ginsenosides in R1, 0.50% acidic polysaccharides and 0.30% ginsenosides in R2, and 7.46% acidic polysaccharides and 0.61% ginsenosides in W. Immuno-enhancing effects of fractions from RGP were examined based on suppression of immune responses by cyclophosphamide. In the first fraction test, the antibody response to SRBCs increased significantly in the R1-treated group, but not the E-treated group. In the second fraction test, W showed higher immuno-enhancing effect than R1 and R2. W, which contained the highest amount of acidic polysaccharides, restored numbers of T and B cells, macrophages, as well as $CD4^+$ and $CD8^+$ T cells in the spleen suppressed by cyclophosphamide. These results suggest that acidic polysaccharides from red ginseng may be more effective than saponin in enhancing immune functions and reducing immunotoxicity of cyclophosphamide.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.1
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• pp.79-89
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• 2023

Development of efficient and stable electrocatalysts for oxygen evolution reaction (OER) under acidic conditions is desirable goal for commercializing proton exchange membrane (PEM) water electroyzer. Herein, we report iridium-doped hydrogenated titanate (Ir-HTO) nanobelts as a promising catalyst with a low-Ir content for the acidic OER. Addition of low-Ir (~ 3.36 at%) into the single-crystalline HTO nanobelts with large exposed {100} facets significantly boost catalytic activity and stability for OER under acidic conditions. The Ir-HTO outperforms the commenrcial benchmark IrO₂ catalyst; an overpotential for delivering 10 mA cm^-2 current density was reduced to about 25% for the Ir-HTO. Moreover, the catalytic performance of Ir-HTO is positioned as the most efficient electrocatalyst for the acidic OER. An improved intrinsic catalytic activity and stability are also confirmed for the Ir-HTO through in-depth electrochemical characterizations. Therefore, our results suggest that low-Ir doped single-crystalline HTO nanobelts can be a promising catalyst for efficient and durable OER under acidic conditions.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.357-362
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• 1992

To understand water flow path in the cells of Robinia pseudoacacia and Pyrus ussuriensis and obtain color wood from them, this experiment was performed by penetrating 0.5% acidic fuchsin and 0.5% fast green solution into the living wood of them. A comparison was made of the wood structure and water flow path from Robinia pseudoacacia containing the ring-porous wood with tyloses, and Pyrus ussuriensis including solitary diffuse-porous wood with distinct fiber pits. The dye penetrated into vessel elements in the early wood of two growth rings from bark in Robinia pseudoacacia, but permeated all xylem in fonts ussuriensis. In Robinia pseudoacacia, the vessels of heart wood and intermediate wood were not stained because of tyloses.

• Microbiology and Biotechnology Letters
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• v.28 no.2
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• pp.111-116
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• 2000

Cultural conditions for the production of water-soluble pigment from mycelial culture of Cordyceps scarabaeicola KEFC-C252 and antimutagenic activity of the pigment were investigated. To obtain the maximum productivity of the pigment from mycelial culture of C. scarabaeicola KEFC-C252, the optimized medium was made with 1.5% sucrose, 2.5% yeast extract and initial pH 5.5. C. scarabaeicola KEFC-C252 was cultivated to reach the maximum concentration of the pigment at $26^{\circ}C$ for 108 hrs. C. scarabaeicola KEFC-C252 produced about 1.2 g/liter pigment under the optimized condition. The pigment was isolated from the culture filtrate by ethylacetate extraction, acidic precipitation and crystallization. The isolated pigment was scarlet hexagonal column crystal, and the color of the pigment was changed according to pH of the solution. The pigment showed violet in the alkaline water but showed red color in the acidic water. The pigment showed inhibitory activity against mutagenic activity induced by 4-nitroquinoline N-oxide. Furthermore, the pigment showed inhibitory activity against spontaneous mutation on Salmonella typhimurium TA98 and TAlOO.

• Applied Microscopy
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• v.45 no.4
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• pp.249-253
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• 2015

Microorganisms specifically groups of bacteria exhibiting physiological activities of production of acids are a major cause of concern because of their ability to induce corrosion in oil field pipelines and metal systems involved in water handling. Water Injection Stations as a means of secondary recovery from existing oil producing reservoirs, are often employed in most upstream oil and gas industries to ensure replenishment of voidage, maintenance of reservoir pressure and optimization of crude emulsion throughput. In the present study, scanning electron microscopy of macroscopic orange coloured slime formations sampled from leaking valves on the flow-lines of a Water Injection Stations of Oil India Limited revealed the presence of filamentous bacterial mats in association with diatoms. The species composition of the acidic slime formations from the sampled locations reveal the possible role of acid producing iron oxidizing bacteria (IOB) like Acidithiobacillus ferrooxidans in association with Gomphonema sp. in creating conditions for bio-corrosion.