• Bulletin of the Korean Space Science Society
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• 2006.10a
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• pp.69-69
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• 2006

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.111-111
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• 2005

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.795-801
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• 1989

The polycrystalline mullite fiber was synthesized from various combination of starting materials including metal alkoxides and colloidal sol by the sol-gel process. The best spinnability was observed in the sol which showed shear thinning and hysteresis (i.e., thixotropic flow), indicating that the network structure was broken down as the shear rate increased. The mullite fiber was polycrystalline after firing and characterized by thermal analysis, XRD, FT-IR spectroscopy, rheological measurements, and SEM.

• Textile Coloration and Finishing
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• v.6 no.1
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• pp.49-53
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• 1994

The transparent coloration of glasses has been successfully achieved by coated glass surface with squarylium dye by the sol-gel colored coating method. Treatment of sol-gel colored coating layer with HCI(g) greatly decreases the absorbance at λ$_{max}$, that increases exposure to $NH_{3}$(g) and the reversible color-colorless responce was extremely rapid.d.

• Bulletin of the Korean Chemical Society
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• v.17 no.2
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• pp.158-162
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• 1996

The steady-state emission and fluorescence lifetimes of 1,3-dipyrenylpropane were measured in silicate sol-gel and xerogel matrices. In sol solution, the fluorescence emission spectra of monomer and excimer resemble those in hydrocarbon solvents. In gel and xerogel condition, however, the fluorescence spectra exhibit significant change, largely confirming the intramolecular motions in gel pores are influenced by microviscosity. The rate constants for intramolecular excimer formation were obtained from the measured fluorescence lifetimes and the rate processes for excimer forming in silicate sol-gel are described by a simple kinetic scheme.

• Journal of the Chungcheong Mathematical Society
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• v.34 no.1
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• pp.17-26
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• 2021

The purpose of this paper is to determine the structure of the crystallographic group 𝚷 of the 4-dimensional solvable Lie group Sol ⁴_m,n that the translation subgroup of 𝚷, 𝚪 := 𝚷; ∩ Sol⁴_m,n, is generated by the particular elements.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.271-277
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• 2000

Transparent $TiO_2$ thin films were prepared by the sol-gel method from titanium alkoxide aqueous solution containing large quantities of water. To prepare the aqueous system sol, the chelate compound solution were prepared from each 1 mole of titanium(IV)iso-propoxide, acetylacetone and 8 moles of isopropyl-alcohol. And then the 50 moles aqueous solution with the 0.02~0.50 moles of HCI for sol stability and the 0.3 mole of polyethylene glycol for coating adhesion were precisely dropped on the chelate compound solution. $TiO_2$thin films were fabricated by dip coating, drying and heat treatment at $400^{\circ}C$ and their characteristics were investigated by XRD, SEM and UV-visible spectrometer, The neutral sol of composition with TTIP : AcAc : IPA : $H_2O$ : PEG : HCl = 1 : 1 : 8 : 50 : 0.3 : 0.15 (molar ratio) was maintained stable sol condition and without problem for coating more than 30 days. The anatase phase $TiO_2$thin film prepared from 30 times dipping, drying and heat treating showed the flat surface and the fine microstructure of fracture surface with about 2 $\mu\textrm{m}$ thickness. Transparency of these $TiO_2$thin film was 80 % in the visible region.

• Fire Science and Engineering
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• v.31 no.3
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• pp.11-18
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• 2017

In this study, a non-halogen type organic-inorganic hybrid flame retardant sol, which can impart flame resistance to synthesize silicate of inorganic material and silane coupling agent of organic material by a sol-gel method, were newly manufactured. The addition of flame retardant will prevent loss of life in a fire because smoke from the flammability of interior finishing materials used as the construction materials poses a major danger. The smoke density measurement standard based on flame retardant performance standards, experiments were conducted according to the test equipment and procedures of ASTM E 662. The non-flaming mode experiment and the flaming mode experiment were conducted to confirm the performance of the manufactured flame retardant sol. As a result, the manufactured flame retardant sol improved the physical properties and heat resistance of existing flame retardants, and decreased the smoke production of the fire. Therefore, it may be possible to reduce the damage caused by smoke and expand the applications to various interior finishing materials.

• Journal of the Korean Ceramic Society
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• v.41 no.10 s.269
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• pp.788-791
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• 2004

We have studied the fabrication of silver micro lines using the silver nano sol on ITO substrate by an ink-jet method. The average particles size of $10wt\%$ silver nano sol synthesized with polyelectrolytes was smaller than 10 nm. The pattern formation of silver nano sol on the substrate closely related with the contact angle of the silver nano sol. The dot shaped of silver nano sol on bare ITO substrate was formed due to the high contact angle of silver nano sol. When ITO substrates was treated with 100 ppm polyethylenimine for silver nano sol patterning, fine silver micro lines of $60{\sim}100{\mu}m$ width was fabricated by ink-jet method.

• Elastomers and Composites
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• v.33 no.5
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• pp.345-354
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• 1998

Rheological properties of polyamide-modified poly(vinyl choride) (PVC)-sol sealants were investigated. PVC-sol was prepared by plasticization with dioctyl phthalate(DOP). Two kinds of polyamide rosins having different amino values and thus different viscosities were compared. The effects of the polyamide types and contents on the viscosities, thixotropic indices, and specific gravities of the PVC-sol were discussed. It was found that viscosities of the PVC-sol sealants were significantly affected by the types of the added polyamide resins, and the thixotropic index of the polyamide-modified PVC-sol sealant was observed to be dependent on the contents(not on the types of the polyamides). The viscosity behaviors of the polyamide-modified PVC-sol sealants aged at $45^{\circ}C$ and the effect of the addition of $CaCO_3$ were also discussed.