• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.179-182
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• 2001

Photocyclizable poly(cinnam-4'-yl methyl methacrylate) derivatives bearing methoxy benzene (PMCMMA), anthracene (PACMMA), and coumarin (PCCMMA) have been synthesized via Heck type reaction. Three different types of polymers are photoreactable usin g linearly polarized UV light and applicable as liquid crystal alignment layer. Anthracence and coumarin containing polymers (PACMMA, PCCMMA) have better thermal stability than PMCMMA. This observation may be attributed to the glass transition temperature elevation due to the bulky size and another photocrosslinking site provided by anthracene or coumarin group.

• Composites Research
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• v.27 no.3
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• pp.109-114
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• 2014

Manufacture of nancomposites has simple process for developing nanocomposites due to the increasing applications using nanofillers. This work studied nanofiller coated glass fiber for reinforcing material with good wetting and conductivity and the morphology of nanofiller coated glass fiber was analyzed by FE-SEM. The durability of reinforced glass fiber was investigated with different shapes of nanofillers using sonication rinsing method. Fatigue test was performed to evaluate the adhesion of reinforcing interface and stability of nanofiller coating layer for single fiber reinforced composites. Apparent modulus and conductivity of nanofiller coating layer were evaluated to realize multifunctional of nanocomposites. Fiber type of nanofiller was better than plate type due to better cohesion between fiber and nanofillers. At last, the stability of fiber type nanofiller of coating layer has better durability and conductivity than plate type case.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.159-163
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• 2013

As mulberry fruit's functionalities are known to the media, the interest in promoting of consumption and processed products is increasing. But there is no C3G(Cyanidin-3-glucoside) data based on the stability of the pigment during processing. To solve this problems, and to expand the use of mulberry fruit, processing methods was developed for mulberry fruit juice improved cyanidin-3-glucoside(C3G) stability. The results obtained are summarized as follows. The food additive citric acid with 0.3 % improved C3G content and antioxidant ability in the treatment of mulberry fruit and sucrose the ratio of 50 % : 50 %(w/w). In the case of the addition of oligosaccharides, citric acid decreased antioxidant ability. Xylitol treatment showed up the lowest of C3 content, but by the addition of citric acid improved the pigment content and antioxidant activity of the mulberry fruit juice. Addition of citric acid was more affected C3G stability than containers (clear glass bottles, brown glass bottles, aluminum foil, green glass bottle, translucent glass bottles). In the processing of mulberry juice, 3 minutes blanching treatment using microwave dropped C3G content somewhat. Therefore, using this method is not recommended. However in the antioxidant ability, microwave blanching showed a stabilizing effect compared to the other treatments.

• International Journal of Concrete Structures and Materials
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• v.10 no.3
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• pp.337-353
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• 2016

The successful completion of the present research would be achieved using ground waste glass (GWG) microparticles in self-consolidating concrete (SCC). Here, the influences of GWG microparticles as cementing material on mechanical and durability response properties of SCC are investigated. The aim of this study is to investigate the hardened mechanical properties, percentage of water absorption, free drying shrinkage, unit weight and Alkali Silica Reaction (ASR) of binary blended concrete with partial replacement of cement by 5, 10, 15, 20, 25 and 30 wt% of GWG microparticles. Besides, slump flow, V-funnel, L-box, J-ring, GTM screen stability, visual stability index (VSI), setting time and air content tests were also performed as workability of fresh concrete indicators. The results show that the workability of fresh concrete was increased by increasing the content of GWG microparticles. The results showed that using GWG microparticles up to maximum replacement of 15 % produces concrete with improved hardened strengths. From the results, when the amount of GWG increased there was a gradual decrease in ASR expansion. Results showed that it is possible to successfully produce SCC with GWG as cementing material in terms of workability, durability and hardened properties.

• Journal of the Korean institute of surface engineering
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• v.44 no.5
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• pp.213-219
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• 2011

Recently aspheric lenses are widely used for superpricision optical instruments, such as cellular phone camera modules, digital cameras and optical communication modules. The aspherical lenses are processed using mold core under high temperature compressive forming pressure. It is imperative to develop superhard protective films for the life extension of lens forming mold core. Especially ta-C films with higher $sp^3$ fractions receive attentions for the life extension of lens forming mold and, in turn, the cost reduction of lenses due to their suprior high temperature stability, high hardness and smooth surfaces. In this study ta-C films were processed on WC mold as a function of substrate bias voltage using FVA (Filtered Vacuum Arc) method. The processed films were characterized by Raman spectroscopy and nano-indentation to investigate bonding nature and hardness, respectively. The film with maximun 87% of $sp^3$ fraction was obtained at the substrate bias voltage of -60 V, which was closest to ta-C film. ta-C films showed better high temperature stability by sustaining relatively high fraction of $sp^3$ bonding even after 2,000 glass lens forming applications.

• Macromolecular Research
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• v.15 no.2
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• pp.185-190
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• 2007

Poly(norbornene dimethyl dicarboxylate)s, (PNDMD)s, were prepared by addition polymerization with palladium(II) catalyst from pure exo-monomers, and their structure and properties were compared with those of poly(norbornene dicarboxylic acid dialkyl ester)s, (PNDADA)s. Both polymer series exhibited good solubility in general organic solvents and excellent thermal stability up to $330^{\circ}C$. Wide-angle X-ray scattering (WAXS) study indicated the presence of nano-scale layer-like order in amorphous PNDADAs, while PNDMDs showed random amorphous structure. The glass transition temperatures and dielectric constants of solid polymers were found to decrease as the alkyl side-chain length increases for both polymer series. However, PNDMDs showed lower glass transition temperatures and higher dielectric constants, as compared with those of PNDADAs containing the same alkyl substituents. This difference, caused by the higher side-group mobility of PNDMDs, may be closely related to the nano-scale order in amorphous PNDADAs and its absence in PNDMDs.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.981-984
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• 2004

We have studied a printability of synthesized silver nano solon ITO glass substrate. The highly concentrated polymeric dispersant-assisted silver nano sol was prepared by variation of molecular weight and control of initial nucleation and growth of silver nanoparticles, to achive dispersion stability and controlling the size of silver nanoparticles. The synthesized silver nano-sol was tested for printability to explore the possibility of micro-electrodes patterning on ITO glass substrate. The silver micro-electrode with 50${\sim}100{\mu}m$ line width was formed on ITO glass substrate.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.175-180
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• 1998

This paper describes evaluation of oxidation stability for diesel engine oils by Hot-tube oxidation tester at high temperature. Evaluation was rated by visual inspection of lacquer in capillary glass tube and TAN determination of used oil. Air, NO$_2$-air and SO$_2$-air mixed gases were used as oxidizing gas. One oil which has low oxidation stability is selected and reformulated by addition of some additives such as antioxidant, detergent and disperant to improve oxidation stability. As a results of reformulation, antioxidant and detergent was effective for improvement of high temperture oxidation stability on diesel engine oil.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1011-1016
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• 2002

Colloidal particles of silica (100 nm in size) were electrostatically dispersed and adsorbed on a glass substrate coated with silica sol or alumina sol. Stability of the suspensions and microstructure of the adsorbed particle layers were discussed in terms of total potential energies between the particles and the substrate. Well-dispersed suspension resulted in a layer with densely packed and regularly arranged particles, whereas less stable suspension resulted in a porous layer with loosely packed and irregularly arranged particles. Despite repulsive interactions between the particles and the substrate coated with silica sol, the observed adsorption can be attributed to chemical bonds formed at the interface between the particle and silica sol. In contrast, the adsorption of the particles on the substrate coated with alumina sol formed a layer with strongly adhered and densely packed particles, due to large attractive interactions between the particles and alumina sol.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.173-178
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• 2008

This is green roof bottom system which composed by aluminum valve and glass fiber together as major reinforcement, so the cooper sheet can have root proof, and using recycled tire gel-type membrane waterproofing system which dost not contains VOCs. The copper sheet reduce the plants' root growing, so it helpes to maintain the waterproofing layer and stability of root proofing. Gel type membrane waterproofing system can do waterproofing, stress dispersion, and reducing leakage expansion. So those two materials can help each other to make green roof bottom layer would have the stability and durability.