• Textile Coloration and Finishing
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• v.28 no.4
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• pp.231-238
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• 2016

We investigated the evolution of crystal formation as a function of drawing ratio in poly(1,4-diaminobutane-co-adipic acid-co-${\varepsilon}$-caprolactam-co-diethylenetriamine)(nylon 466T) copolymer formed by four monomers, i.e 1,4-diaminobutane, adipic acid, ${\varepsilon}$-caprolactam, diethylenetriamine(DETA), using synchrotron X-ray scattering measurement. In case of pristine(as spun) nylon 466T fiber, it was consisted with unoriented nylon $6{\alpha}$ and unoriented nylon $46{\alpha}$ phases. As increase the drawing ratio, unoriented nylon $6{\alpha}$ was transformed to oriented ${\gamma}$ phase, while unoriented nylon $46{\alpha}$ changed to oriented $46{\alpha}$ phase. The effect of the addition of DETA was not observed in the pristine fibers. However, DETA affected to restrict the formation of crystals at the maximum drawing condition, and as a result it had a role to increase the moisture regain.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.374-374
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• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.1
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• pp.1-3
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• 2001

No abstract, See Full-text.

• Proceedings of the Optical Society of Korea Conference
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• 2005.07a
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• pp.92-93
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• 2005

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.2-6
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• 2009

This presentation reviews the current progress in the technology of Light Emitting Diode (LED) as it relates to the LED backlight for Liquid Crystal Display (LCD). A vivid description is given about the performance of LED that is still on the rise and certain limitations of LED that is on the decline.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.133-134
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.23-24
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• 2006

• Journal of Pharmaceutical Investigation
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• v.41 no.1
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• pp.45-50
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• 2011

Nonclassical pathway of crystallization has been utilized to modify the properties and morphologies of inorganic and organic/inorganic materials. In here, the polymer-directed crystallization method has been applied to the pharmaceutical active ingredient to assess the applicability for as a particle engineering tool. The polymer-directed crystallization was successful to modifying the crystal size, habit and morphology, but it was not effective to discover the novel polymorphs of Sibutramine (SB). SB was selected as a model drug and polyacrylic acid (PAA), polyethylene imine (PEI) and chitosan (CHI) were added as a crystallization pathway modifier. SB was crystallized via drowning crystallization using methanol or ethanol as a solvent and water as a non-solvent. The significant interactions between polymer and the drug were confirmed by measuring the solubility of the drug in presence of polymer during the crystallization. The crystal forms of SB are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and optical microscope (OM). The polymer-directed crystallization seems to be able to modify the crystal properties of pharmaceutical active ingredient, which is critical in determining the bioavailability, processability, and stability.

• YAKHAK HOEJI
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• v.3 no.1
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• pp.23-25
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• 1957

The herb of Geranium sibirium L, a drug knwon as "Chui Sonni Poul" distributed widely, has been used as a folk-medicine for the treatment of diarrhea. The dried entire herb is boiled with methanol and methanol is distilled of from the filtered methanol extract under reduced pressure. Then the extract is boiled with water and filtered off. From the filtrate, the following substances are isolated and identified by treating with organic solvents as ether, ethyl acetate, and etc.: 1. Gallic acid: a colorless needle crystal which is soluble in alcohol and water. mp.235.deg. C, positive (dark blue) against the ferric chloride reagent. 0.76 percent of gallic acid is yielded from the herb. 2. Quercetin: a light yellow crystal. mp.194.deg. C. negative against the ferric chloride reagent. 3. Ellagic acid: a light yellow crystal which is insoluble in ehter and acetone and slightly soluble in alcohol. Positive (blue) against the ferric chloride reagent. The crystal obtained by recrystalisation from pyridine, does not melt by 360.deg. C. Represent a yield of 0.03 percent from the herb. 4. Crude tannin: a approximately 7.6 percent of crude tannin is yielded by treating with ethyl acetate. gallic acid and querceetin are yielded by hydrosis with dliute sulfuric acid. Based on the above results, the following suggestion could be recommendable; Geraed in the Japanese Pharmacoeia VI.acoeia VI.

• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1358-1362
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• 2007

The structures, energetics and transfer integrals of the acene tetramers up to pentacene are investigated with the ab initio molecular orbital method at the level of second-order Møller-Plesset perturbation theory (MP2). Calculated geometries for the herringbone-style structures found in the crystal structure were characterized as local minima, however the geometrical discrepancy between crystal and MP2 theoretical structure is reasonably small. The binding energy of pentacene tetramer was calculated up to 40 kcal/mol (MP2/6-31G(d)) and about 90 kcal/mol (MP2/aug-cc-pVDZ), and the latter seems to be too much overestimated. The tendency of the hole transfer integrals computed with ab initio MP2/3-21G(d) geometry is well agreement with those estimated with crystal structure with some discrepancy, and the gradual increment of the transfer integrals at the crystal geometry is attributed to mainly packing structure rather than the intrinsic property of acene such as a size of acene.