• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.92-92
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• 2010

Replacing the existing illumination with solid-state lighting devices, such as light-emitting diodes (LEDs) are expected to reduce energy consumption and environmental pollution as they provide better efficiency and longer lifetimes. Currently, white light emitting diodes are composed of UV or blue LED with down-converting materials such as highly luminescent phosphors White light-emitting diodes (LED) were fabricated with multi-shell nanocrystal quantum dots for enhanced luminance and improved stability over time. Multi-shell quantum dots (QDs) were synthesized through one pot process by using the Successive Ionic Layer Adsorption and Reaction (SILAR) method. As prepared, the multi-shell QD has cubic lattice of zinc-blend structure with semi-spherical shape with quantum yield of higher than 60 % in solution. Further, highly fluorescent multi-shell QD was deposited on the blue LED, which resulted in QD-based white LED with high luminance with excellent color rendering properties.

• Journal of the Korean institute of surface engineering
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• v.34 no.4
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• pp.313-320
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• 2001

It is well known that the amount of hot-dip Zn coated sheet steels used for automotive is rapidly increasing. As hot-dip steel sheets show good corrosion resistance and excellent formability, the demand for outer panel of automotive has been increased in order to satisfy with the requirement of high surface qualify. There are many kinds of factors influencing on the surface quality and the dross control in the galvanising bath is regarded as one of the most important thing. In this study the characteristic and growing behavior of dross in the galvanizing bath were investigated and the effect of dross on the surface defect of GA was surveyed. The dross defects on the GA sheet steels result from bottom dross whose diameter are larger 50$\mu\textrm{m}$ in the Zn pot. Dross-free state exist for about 30 hours from starting time of GA production.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.80-84
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• 1989

Two properties of sodium naphthalenide (2), i.e. a strong base and a good electron donor were utilized for one pot synthesis: 2-alkylthiobenzimidazoles were synthesized in excellent yields from the reactions of benzimidazoline-2-thione (1) with an equimolar amount of alkyl halides in the presence of 2. Continuous addition of a different alkyl halide without the isolation of 2-alkylthiobenzimidazoles afforded 1-alkyl-2-alkylthiobenzimidazoles having different alkyl groups at N and S atoms in excellent yields. Further addition of 2 to 1-alkyl-2-alkylthiobenzimidazoles gave excellent yields of 1-alkylbenzimidazoline-2-thiones. When 2 in THF was added to a suspension of 1-alkyl-2-alkylthiobenzimidazoles in THF, a bond cleavage between N and C of alkyl group as well as S and C of alkyl group occurred. This is in contrast to the observation in which only cleavage between S and C of alkyl group takes place in the homogeneous solution.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.6-13
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• 2018

Well-modified amino-appended ${\beta}$-cyclodextrin ($AA-{\beta}-CD$) with an amino group at the primary face of the ${\beta}-CD$ was synthesized and used in the catalytic synthesis of chromeno pyrimido[1,2-b]indazol as supramolecular catalysts in water for the first time. $AA-{\beta}-CD$ was characterized by FT-IR, NMR, MALDI-TOF mass spectrometry, and SEM analysis. A possible reaction mechanism featuring molecular complexation was suggested based on 2D NMR (ROESY) spectroscopy, FE-SEM, DSC, and FT-IR. Advantages such as operational simplicity, recyclability of the catalysts, and accessibility in aqueous medium render this protocol eco-friendly.

• Bulletin of the Korean Chemical Society
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• v.21 no.8
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• pp.797-800
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• 2000

The reaction of o-acylthiophenacyl chloride 5a with onc equivalent ofsodium azide in aqueous acetone at-10~ $-5^{\circ}C$ gave 2,9-dimethyl-6H,I3H-dibenzo[d,i][1,6]dithiecin-7,14-dione 7(10%),acyclic dimer 8(64%),and tri-mer 9 (8%). Dimer 8 and trimer 9 we re converted readily to 7 under the similar conditions at room temperature in yields of 72% and 53%,respectivel. Also, one pot synthesis of 7 (64%, 45%) from the reaction of 5a or 5b with two equivalents of sodium azide at room temperature was very successful.

• Journal of Integrative Natural Science
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• v.2 no.4
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• pp.285-288
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• 2009

A synthetic route for 12 metal thiocarboxylate complex, $Cd(SOCCH_3)_2Lut_2$ [Lut = 3,5-dimethylpyridine (lutidine)], were investigated for their potential to act as precursors for the formation of cadmium sulfide nanoparticles. $Cd(SOCCH_3)_2Lut_2$ were characterized by 1H-NMR spectroscopy. Thermal decomposition of $Cd(SOCCH_3)_2Lut_2$ is expected to undergo thiocarboxylic anhydride elimination to give stoichiometric cadmium sulfide nanoparticles and removes the organic supporting ligands cleanly. Prepared cadmium sulfide nanoparticles were characterized by fluorescence and UV-vis absorption spectroscopy and displayed an emission band at 500 nm with an excitation wavelength of 360 nm.

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.1-4
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• 1989

6-Arylamino-3,7-dihydro-3,7-dimethy-2-oxo-1H-purine and 2-arylimino-6-arylamino-3,7-dihydro-3,7-dimethyl-1H-purine were obtained in a one-pot reaction when 3,7-dihydro-3,7-dimethyl-1H-purine-3,6-dione, phosphorus pentaoxide, triethylamine hydrochloride and appropriate amine amino are heated at $170^{\circ}$. Some derivatives were tested for their antitumor activity.

• YAKHAK HOEJI
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• v.48 no.3
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• pp.202-206
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• 2004

New asymmetric dimers, N,N'-dialkyl-4'-hydroxy-4-oxo-2,2',3,3'-tetrahydro-2,2'-diphenyl-4,4'-quinolones 3a-f were synthesized through the dehydration and dea1coholation of N-alkylanilines and ethyl benzoylacetate. Dimers 3a-f were identified by NMR, IR and GC-MS. A series of dimer 3a-f has been synthesized using acid-catalyzed one-pot reaction that involved the condensation, cyc1ization and dimerization. Similarly, the 6,6'-methoxy (or 7,7'-methoxy) substituted dimers were prepared from N-alkyl-meta-(or para)-anisidines. Formation of dimers was undertaken with p-toluenesulfonic acid (p-TSA) at 90∼11$0^{\circ}C$ in toluene for 2∼6 hours over the Dean-Stark apparatus.

• Archives of Pharmacal Research
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• v.27 no.1
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• pp.19-24
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• 2004

The facile synthesis of a series of 2-(4-hydroxyphenyl)benzofurans (4a-e) is described. The one-pot reaction of 4-substituted phenols with the chloride 1 in the presence of zinc chloride afforded 3-methylthio-2-(4-acetoxyphenyl)benzofurans (2a-e). The compounds 4a-e were obtained from the hydrolysis of 2a-e followed by the desulfurization of the resulting 3-methylthio-2-(4-hydroxyphenyl)benzofurans (3a-e). 5-Methyl-3-p-toluoyl-2 -[4-(3-diethylaminopropoxy)phenyl]benzofuran (7), a $\beta$-amyloid aggregation inhibitor, was synthesized by three steps starting from 4a.

• Mycobiology
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• v.46 no.4
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• pp.341-348
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• 2018

A new species of arbuscular mycorrhizal fungi (Glomeromycota), Acaulospora koreana, was isolated from forest soils in South Korea. This novel fungus was collected from the rhizosphere of Lindera obtusiloba and Styrax obassia in forest and propagated with Sorghum bicolor in pot. Morphological characteristics of spores of A. koreana are rarely distinguished from Acaulospora mellea, which is reported as one of the most abundant mycorrhizal species in Korea. However, molecular evidence of rDNA sequence using improved primers for glomeromycotan fungal identification strongly supported that A. koreana is different from A. mellea but also any other species belonging to the genus Acaulospora. This is the first novel glomeromycatan fungus introduced in South Korea, but it suggests that there is a high possibility for discovering new arbuscular mycorrhizal fungi considering the abundance of plant species and advanced phylogenetic analysis technique.