• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.885-893
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• 2012

DME (Dimethyl ether) is regarded as one of the candidates of alternative fuels for diesel engine, because of its higher cetane number suitable for a compression ignition engine. Also, DME is a simple chemical structure, colorless gas that is easily liquefied and transported. On the other hand, Bunker oil (JIS C heavy oil) has long been used as a basic fuel in marine diesel engines and is the lowest grade fuel oil. In this study, the combustion and emission characteristics were measured experimentally in the direct injection type diesel engine operated with DME and Bunker oil mixed fuel. From our experimental results, it is induced that DME and Bunker oil blended fuel would be an effective fuel which can reduces the concentration of harmful matter in exhaust gases.

• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.264-268
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• 2017

South Korea has the highest reported suicide rate among all countries belonging to the Organization for Economic Cooperation and Development. Nitrogen is a colorless, odorless and nontoxic gas. Nitrogen gas has, however, been recently used as a method of attempted suicide, its nontoxity notwithstanding. We herein report on an unusual case involving a 30-year-old male who presented with symptoms after a suicide attempt by nitrogen inhalation. Diffusion-weighted imaging of his brain was showed curvilinear high signal intensity in the bilateral frontal and right occipital cortices, with subtle low apparent diffusion coefficient value. In addition, T2-weighted images and fluid attenuated inversion recovery images revealed subtle high signal intensity in the bilateral frontal cortices, basal ganglia and occipital cortices with contrast enhancement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1495-1498
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• 2003

Recently, self-healing methods of a cracked matrix, especially polymeric composite materials, became the center of engineering researchers. In this paper, we summarized the self-healing concept for polymeric composite materials and investigated the effect of microparticle on the crack growth behavior in colorless and transparent matrix by experimental observation to describe the crack propagation around the microparticle inside epoxy matrix composite. Compression splitting test for the specimen involving microparticle was conducted. In addition, FE analysis was pursued to present the stress contour around microparticle in the matrix. Through the experiments and FE analysis, we found that the size. relative position, bonding condition and relative stiffness of microparticle are important parameters to decide the direction of crack propagation, which is related to the rupture of microparticle for self-healing

• Korean Journal of Pharmacognosy
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• v.13 no.3
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• pp.132-135
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• 1982

Three phenolic alkaloid compounds (A,B,C) were isolated from the roots of Thalictrum uchiyamai Nakai (Ranunculaceae). Compound A, a colorless crystalline substance $mp168^{\circ}$, $C_{11}H_{15}NO_2$ was identified to be corypalline (6-methoxy-7-hydroxy-N-methyl-1, 2, 3, 4-tetrahydroisoquinoline) which has been reported by Wu from Thalictrum rugosum. Compound B, $mp166^{\circ}$ and Compound C, $mp164^{\circ}$ were shown aromatic rings by UV, IR spectra and chiral center by CD.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.55-57
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• 1999

Botrytis cinerea was isolated from a gray mo이 leaf lesion on persimmon in fields of Kyeonsangnam-do from 1996 to 1998, and etiological study was conducted including physiological characteristics. It formed gray mold lesion with light green color on leaves of persimmon (Diospyros kaki). The temperature range for mycelial growth was between $5^{\circ}C$ and $30^{\circ}C$ with the optimum temperatures of $20^{\circ}C$ to $25^{\circ}C$. Conidia were oviod, cylindric, and colorless and their dimensions in culture were $8.4~11.5\times7.0~8.9\mu\textrm{m}$. The optimum temperature of conidial germination was $25^{\circ}C$. Sclerotia on potato dextrose agar medium were well formed and brownish condiophores were observed with their size of $18.5~64.9\times4.5~8.0\mu\textrm{m}$. Symptoms on artificially inoculated plants were similar to those of gray mold disease on persimmon caused by Botrytis cinerea in fields.

• Textile Coloration and Finishing
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• v.7 no.1
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• pp.72-79
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• 1995

The effect of copper sulfate/thiourea on the diffusion and the dye exhaustion of two dyes, C. I. Acid Orange 7 and C. I. Food Yellow 3 in nylon 6 fiber has been studied. The results obtained from the experimetal are as follows : 1) Copper sulfate reacted with thiourea at constant temperature and then generated the colorless trasparent coordination compound, and then combinated end group of carboxyl of nylon 6 fiber. 2) The coordination compound [$Cu_{2}$($TU_{6}$)] ($(SO_{4})_2$) is conducted at pH 5-6 in solution intensity and repulsed the sulfonic acid group of dyes, and therefore the diffusion of dyes is restraint. 3) Dye uptake and diffusion coefficient were decreased in the order of untreated > copper sulfate/thiourea-treated > tannin-treated.

• Macromolecular Research
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• v.13 no.3
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• pp.180-186
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• 2005

A novel bifunctional dye composed of spirobenzopyran and a cinnamoyl moiety was prepared and its photochromic behavior under the illumination of monochromatic UV light was investigated. This colorless bifunctional dye exhibits typical photochromism in both the film and in solution, through the structural and geometrical transformation from spirobenzopyran to merocyanine accompanied by a photocrosslinking reaction between the cinnamoyl moieties. Two kinds of photochemical reaction were selectively achieved by irradiation with monochromatic UV light at wavelengths of 275 and 365 nm, respectively. The effect of the selective photochemical reaction on the photochromism of the dye and its decaying behavior was investigated.

• Textile Coloration and Finishing
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• v.25 no.2
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• pp.83-88
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• 2013

Rhodamine dyes have been studied in various scientific areas due to their excellent photophysical properties. In particular, these rhodamine dyes are one of the most famous fluorophores as signal unit in chemosensor study. This is related to spirolactam ring system in rhodamine dyes. When the spirolactam ring is closed, there is nonfluorescence and colorless. Whereas, ring-opening of the corresponding spirolactam induces strong fluorescence and color. These absorption and emission changes are related to structural changes as well as electron energy potential levels such as HOMO and LUMO values. In this study, two different structures of rhodamine 6G hydrazide depending on the spirolactam ring system were investigated using absorption measurement, electrochemical measurement and computational calculations.

• YAKHAK HOEJI
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• v.11 no.3_4
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• pp.22-26
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• 1967

From the root of Angelica gigas $N_{AKAI}$ (Umbelliferae), known as "Tang Gui" in Korea, substance A (colorless needle crystal, $C_{14}H_{14}O_{4}$, m.p. $178^{\circ}$) and B (white plate crystal, $C_{19}H_{20}O_{5}$, m.p. $111^{\circ}$) were obtained. Acetylation of "A" gave its monoacetate, white needles, $C_{16}H_{16}O_{5}$. Saponification of "B" with 5% sodium hydroxide produced "A" and senecionic acid. Examination using I.R. and N.M.R. spectra shows that "A" is identical with decursinol and that "B" with decursin. The root also appears to contain five coumarin derivatives and two steroidal compounds.

• Animal Systematics, Evolution and Diversity
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• v.29 no.2
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• pp.144-151
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• 2013

Two marine hypotrichous ciliates, Anteholosticha petzi and Ponturostyla enigmatica, were collected from the Yellow Sea and the Korea Strait, respectively, and described using live observation and protargol-impregnated specimens. Furthermore, the nuclear small subunit ribosomal RNA gene of each was sequenced and compared to previously annotated sequences retrieved from the GenBank. Anteholosticha petzi is characterized by 3 frontal cirri (FC), 2 frontoterminal cirri (FTC), 8-12 transverse cirri (TC), 1 buccal cirrus (BC), 9-12 midventral pairs (MP), 3 bipolar dorsal kineties (DK), and 3 types of colorless cortical granules. Ponturostyla enigmatica is characterized by 8 FC, 5 ventral cirri (VC), 5-7 TC, 6-7 marginal rows (MR) on each side, 4 complete and 2-3 partial DK, and greenish cortical granules. This is the first identification and description of these 2 species, A. petzi and P. enigmatica, in South Korea.