• Journal of the Microelectronics and Packaging Society
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• v.10 no.1
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• pp.1-5
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• 2003

The multi-layered OELDs(organic electroluminescent devices) were prepared on the patterened ITO (indium tin oxide)/glass substrates by the vacuum thermal evaporation method. The $Alq_3$ (tris-(8-hydroxyquinoline)aluminum) low molecule compound was used as the light emission layer. TPD(triphenyl-diamine) and $\alpha-NPD$ were used as the hole transport layer. CuPc (Copper phthalocyanine) was also used as the hole injection layers. In addition, QD2 (quinacridone2) organic material with $10\AA$ thickness was deposited in the $Alq_3$ emission layer to improve the luminance efficiency. The threshold voltage was about 7V for all devices. The luminance and efficiency of devices was improved by substitution the $\alpha-NPD$ for TPD as the hole as the hole transport layer. The luminance efficiency of the OELD sample with QD2 thin film in the $Alq_3$ emission layer was found to be 1.55 lm/W, which is about 8 times larger value compared to the sample without QD2 thin layer.

• YAKHAK HOEJI
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• v.34 no.4
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• pp.244-251
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• 1990

N-Monoalkylations of ditertiary diamines succeed best in nitromethane or ethanol at low temperature. Unsymmetrical 1,2-diaminoethane, 1,3-diaminopropane and piperazine compounds react selectively under these conditions at the sterically less hindered nitrogen atom.

• Bulletin of the Korean Chemical Society
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• v.3 no.2
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• pp.76-78
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• 1982

Ethanolic tetracarbonylhydridoferrate solution combined with glutaraldehyde is a very effective reducing agent for the selective transformation of two moles of secondary amines into pentane-1,5-diamine derivatives. A variety of aliphatic secondary amines react with ferrate-glutaraldehyde at room temperature under carbon monoxide to give the corresponding N-substituted pentane-1,5-diamines in reasonable yields.

• Journal of the Korean Chemical Society
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• v.29 no.5
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• pp.490-495
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• 1985

Novel palladium (II) complexes, $[Pd((ieaa)_2-en)]$ and [PdCl((ieaa)-l-pn)] ($(ieaa)_2-en)]$ and (ieaa)-l-pn denote N,N'-ethylenebis(isonitrosoethylacetoacetate imine) and l-N-(2-aminopropyl)-isonitrosoethylacetoacetate imine, respectively), have been prepared. The palladium (II) complexes were characterized on the bases of the electronic absorption, circular dichroism (CD), $^{13}C$ NMR, infrared, and Raman spectra. The reaction of palladium(II) cliloride and isonitrosoethylacetoacetate (ieaa) with methylenediamine gives an $(ieaa)_2-en)]$ type Schiff base, while similar reaction using l-propylenediamine instead of ethylenediamine gives an (ieaa)-l-pn type Schiff base. The difference in formation is discussed from the stereochemical viewpoint of the diamine employed.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.71-75
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• 2006

The yellow emitting OLED using GDI602:Rubrene(10%) material has been fabricated and characterized. In the device fabrication, 2-TNATA [4,4',4'-tris(2-naphthylphenyl-phenylamino)-triphenyl-amine] as a hole injection material and NPB[N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl -4,4'-diamine] as a hole transport material were deposited on the ITO(indium thin oxide)/glass substrate by vacuum evaporation. And then, yellow emission material was deposited using GDI602 as a host material and Rubrene(10%) as a dopant. Finally, small molecular OLED with the structure of $ITO/2-TNATA/NPB/GDI602:Rubrene(10%)/Alq_{3}/LiF/Al$ was obtained by in-situ successive deposition of $Alq_{3}$, LiF and Al as the electron transport material, electron injection material and cathode. The yellow OLED fabricated in our experiments showed the color coordinate of CIE(0.50, 0.49), the luminance of $2300\;Cd/m^{2}$ and the power efficiency of 0.7 lm/W at 10 V with the peak emission wavelength of 562 nm.

• Journal of the Korean Chemical Society
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• v.35 no.1
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• pp.46-50
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• 1991

Some nickel(II) complexes have been derived from the condensation of isonitrosobenzoylacetone and diamine(ethylenediamine and propylenediamine) in the presence of metal ion. It is suggested that an isonitroso group(=N-O) of the ligand coordinates to metal through nitrogen atom to form a five-membered ring while other =N-O coordinates to metal through oxygen atom to form a six-membered ring in Ni(IBN)$_2$-en ((IBA)$_2$-en = N,N'-propylenebis(isonitrosobenzoylacetone imino)). But both isonitroso groups of the ligand coordinate to metal through nitrogen atoms to form five-membered rings in Ni(IBA)$_2$-pn ((IBA)$_2$-pn = N,N'-propylenebis(isonitrosobenzoylacetone imino)).

• Journal of the Korean Ceramic Society
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• v.35 no.5
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• pp.421-428
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• 1998

The effect of silane coupling agents on the water stability of HAC/PVA based MDF cement composites which were modified with urethane and epoxy resin were studied as a function of the functional groups and addition amount of silane coupling agent. According to the composition of polymer matrix the silanes with different functional groups showed the different effectiveness. In case of the only PVA matrix the silane with vinyl functional group was more effective than other silanes. When the epoxy resin was added the silane of epoxy-methodxy group enhanced the flexural strength of dry and wet state more than other. In case of urethane-added MDF cement the silane of diamine group was effective and enhanced the water sta-bility fo MDF cement composite more and more as the addition amount of silane increased, Especially in case of warm-presed composite the effect of silane was enhanced By addition of 2wt% of silane with 야-amine group the flexural strength of urethane-added composites were enhanced by 20% more in dry state 40-70% in wet state in accord with the porosity analysis. The flexural strength of the poxy resin-added MDF cement composite was increased by addition of 1wt% and 2wt% silane of epoxy-methoxy group However the addition of 4wt% of silane decreased the flexural strength of dry and wet state by formation of closed pore in the polymer matrix.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.593-599
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• 2007

In this study, we examined the volatile flavor components in the mashes of takju prepared using different yeasts such as Saccharomyces coreanus, S. ellipsoideus, S. carlsbergensis, S. cerevisiae (Baker's yeast), and S, rouxii by GC and GC-MS. Fourteen alcohols, 13 esters, 5 acids, 3 aldehydes, 7 amines, and 2 other compounds were identified in the mash after 6 days of fermentation. On day 6, the takju fermented by S. coreanus had the greatest variety of volatile flavor components. Fifteen flavor components, including ethanol, isobutyl alcohol, isoamyl alcohol, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzeneethanol, ethyl lactate, acetic acid, acetaldehyde, and 1,3-cyclohexane diamine, were typically detected in all the treatments. The relative peak areas of the volatile components were as follows: alcohols (96.758-99.387%), esters (0.081-0.968%), acids (0.040-0.640%), aldehydes (0.266-0.959%), and amines (0.011-0.047%). In particular, 1-propanol, isobutyl alcohol, 3-methyl-1-butanol, 2,3-butanediol, trimethyl benzylalcohol, heptene-2,4-diol, ethyl lactate, diethyl succinate, ethyl nonanoate, methyl hexadecanoate, linoleic acid, hexadecanoic acid, and acetaldehyde were hish in the takju made by S. coreanus. Also, ethyl stearate was high in the takju made by S. carlsbergensis, and hexanoic acid was high in the takju made by S. cerevisiae. Finally, methyl pentanol, 1,3-butanediol, 3-methylthio-1-propanol, benzene ethanol, ethyl octadecanoate, acetic acid, pentanal, and 1,3-cyclohexane diamine were high in the takju made by S. rouxii.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.467-475
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• 2021

The purpose of this study was to compare the effect of sodium fluoride(NaF) varnish and potassium iodide(KI) on remineralization efficacy of silver diamine fluoride(SDF) by measuring microhardness and evaluating surface morphology by scanning electron microscope(SEM). Artificial caries lesions were induced on extracted primary molars and vickers microhardness was measured. Specimens were randomly separated into 4 groups for treatment. The specimens in group I were treated with SDF, group II with NaF varnish after SDF, group III with KI after SDF and group IV with distilled water. After 8 days of pH cycling, vickers microhardness was measured and difference before and after treatment was calculated. For SEM, 2 samples were evaluated respectively after enamel polishing, lesion formation and after pH cycling. Group III showed highest increase in microhardness. Group I showed higher increase in microhardness than Group II but without statistical difference. Group IV showed lowest increase in microhardness value among 4 groups. On SEM image, group I, II and III showed smoother and less irregular surface compared to group IV. Amorphous crystal pellicles were observed in group III. In conclusion, SDF, SDF and NaF, SDF and KI groups showed smoother surface and increase in microhardness suggesting the possibility that remineralization effect might take place in oral conditions. In addition, in limited conditions of this study, applying NaF varnish after SDF did not increase the remineralization efficacy of SDF while KI significantly increased the remineralization efficacy of SDF. However, additional study considering various conditions that might affect demineralization and remineralization in clinical situations need to be conducted.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.15-20
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• 2022

Aerogel is a material having a nanopore structure based on a high porosity. Due to this high porosity, it has excellent properties not found in conventional materials, but its application has been limited due to low mechanical strength. Therefore, to improve the mechanical strength of the aerogel, polyurea crosslinking was introduced and a precursor having an amine group essential for polyurea polymer formation was selected to synthesize a polyurea crosslinked aerogel composite. In addition, the crosslinking of polyurea was adjusted according to the number of amine groups present in aminosilane. It was confirmed through various analyses that the nanopore structure of the aerogel was maintained to have mesopores. The aerogel thus formed was able to improve the mechanical strength by about two times, and it was confirmed through field emission scanning electron microscope analysis that a one-dimensional polymer was formed on the silica aerogel surface through the introduction of ethylene diamine. The one-dimensional polymer thus formed has improved mechanical properties, resulting in securing an elastic modulus of about 2.66 MPa.