• Transactions on Electrical and Electronic Materials
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• v.5 no.4
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• pp.161-165
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• 2004

In order to get oxidizing power enough for growth of a superconductive thin film with oxide gas, concentrated ozone was used. As a method for concentrating ozone, a method for concentrating ozone by adsorbing ozone selectively into silica-gel beads is adopted, and this concentration is analyzed by the ultraviolet absorption method, the thermal decomposition method and the Q-mass analyzing method. Thermal decomposition method is most effective for measurement of a high concentration of ozone. Ozone as concentrated by the adsorption method got to have a concentration of 97 mol % at the maximum, and it was identified that the concentration of the ozone gas was stable for the time while a thin film was formed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.142-145
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• 1993

$TiO_2-V_2O_5$ thin films are fabricated by Sol-Gel method and humidity sensing properties have been investigated. As the results of humidity sensing properties of thin films fabricated as humidity sensor, it is confirmed to have good humidity sensing properties in high humidity and low frequency regions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.234-234
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• 2008

Chemically homogeneous $Ba_{0.6}Sr_{0.4}TiO_3$ (BST) sols were synthesized using barium acetate, strontium acetate, and titanium isoproxide as starting materials. BST thin films of thickness 340 nm were deposited on Pt/$TiO_2/SiO_2$/Si and alumina substrates using spin coating method. The technique used for the processing of these films was Ultraviolet (UV) sol-gel photoannealing, using phto-sensitivity precursor solutions and UV-assisted rapid thermal processing(UV-RTP). The crystallization behaviour of the BST sols and thin films was studied by differential thermal analysis (DTA) and X-ray diffraction (XRD). Variation of permittivity and dielectric loss were measured in LCR-meter, model HP 4394A.

• Korean Journal of Pharmacognosy
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• v.13 no.3
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• pp.106-111
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• 1982

Melampyrum roseum Max. is an annual herb in Scrophulariaceae plants. The materials were collected in Kyeongi-Do in 1980. The BuOH extract was evaporated under reduced pressure. The residue was column chromatographed over silica gel with benzene-MeOH (8 : 1) as an eluent and it gave the amorphus powder. Compound I has a molecular formula $C_{17}H_{26}O_{10}$ and it was identified as mussaenoside by chemical data, UV, IR, NMR spectra and compared with the authentic sample of mussaenoside tetraacetate.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.63-68
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• 1997

In the screening of antiviral materials produced by actinomycetes, an isolate named B25 was fond to produce an antibiotic substance ASA, which showed a strong inhibitory activity against tobacco mosaic virus (TMV) infection. ASA was purified from culture broth of B25 by silica gel column chromatography, preparative TLC, and reversed phase HPLC. Also MS, IR, UV spectrum, and melting point of ASA were determined and analysed. ASA was white powder soluble in dimethyl sulfoxide, chloroform, and ethyl acetate, having absorption peaks at 223 and 328 nm in UV-VIS spectrum, and had a molecular weight of 548. ASA showed strong inhibitory effect on TMV infection when it was applied as a mixture of TMV to the upper surface of leaves of a local lesion host (Nicotiana tabacum c. Xanthi-nc). It also showed antimicrobial effect against yeast and some phytopathogenic fungi.

• Journal of the Korean Ceramic Society
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• v.38 no.2
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• pp.238-238
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• 2001

15% Syn M, sintered mullite(SM) and fused mullite(FM) was added to produce high alumina refractory materials. Mullite content of SM, FM and Syn M was 93.17%, 86.79%, 97.57% repectively. Mechanical properties of specimens (added 15wt% mullite) ware investigated to be flexural strength 338.60MPa, compressive stcngth 9,427kgf/㎠. But the specimen which imported mullite was added showed 5~10%l lower stregth than syn M added.

• Carbon letters
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• v.14 no.3
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• pp.131-144
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• 2013

The carbon nanotube (CNT) represents one of the most unique inventions in the field of nanotechnology. CNTs have been studied closely over the last two decades by many researchers around the world due to their great potential in different fields. CNTs are rolled graphene with $SP^2$ hybridization. The important aspects of CNTs are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful as fillers in different materials such as polymers, metallic surfaces and ceramics. CNTs also have potential applications in the field of nanotechnology, nanomedicine, transistors, actuators, sensors, membranes, and capacitors. There are various techniques which can be used for the synthesis of CNTs. These include the arc-discharge method, chemical vaporize deposition (CVD), the laser ablation method, and the sol gel method. CNTs can be single-walled, double-walled and multi-walled. CNTs have unique mechanical, electrical and optical properties, all of which have been extensively studied. The present review is focused on the synthesis, functionalization, properties and applications of CNTs. The toxic effect of CNTs is also presented in a summarized form.

• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.123-126
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• 2011

Titanium dioxide ($TiO_2$) thin films were deposited by the sol-gel method with a surfactant-assisted mechanism. Its application for dye-sensitized solar cells (DSSCs) was investigated. Brunauer-Emmett-Teller, X-ray diffraction and field emission scanning electron microscopy techniques were used to characterize the surface characteristics of thin films. Photovoltaic-current density measurements were performed to determine the photoelectrochemical properties of the thin films and the performance of DSSCs. Energy conversion efficiency of about 6.1% was achieved for cells with conductive glass under illumination with AM 1.5 (100 $mWcm^{-2}$) simulated sunlight. Investigation showed higher photo-energy conversion efficiency for mesoporous $TiO_2$ nanocrystalline films used in DSSCs relative to commercially available Degussa P25 films.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.13-16
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• 1998

Poly(vinyl alcohol) (PVA) gels are easily formed via physical pathway. Most PVA solutions including PVA/water solution are well known to form thermally reversible gels at low temperature but these gels showed poor mechanical properties. In order to overcome this weak point, transparent crosslinked PVA hydrogels were prepared by electron beam irradiation or by chemical process with crosslinking agents or additives. (omitted)

• Transactions on Electrical and Electronic Materials
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• v.2 no.2
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• pp.42-45
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• 2001

An ozone condensation system is evaluated from the viewpoint of an ozone supplier for Bi-superconductor thin film growth. An ozone condenser by a selective adsorption on the silica gel surface is constructed. Ozone density is evaluated by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is found to be available to the density evaluation from dilute to highly condensed ozone. The highest ozone density condensed by the adsorption method is evaluated to be 97 mol%.