• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 토목섬유 학술발표회 논문집
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• pp.39-55
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• 1999

Geotextile composites to improve the weather ability were composed of recycled polyester geotextile with carbon black as ultraviolet stabilizer and polypropylene geotextile by needle-punching method, and evaluated physical properties, ultraviolet resistance and chemical stability. Retention ratio of tensile properties of non woven polypropylene geotextiles were decreased about 50% by the exposed condition with ultraviolet but those of geotextile composites were slightly decreased than polypropylene geotextiles. Geotextile composites which have larger weights of polyester geotextile were more stable against ultraviolet. For chemical stability, the changes of tensile properties of geotextile composites were in the range of -20~＋10% at the various chemical conditions.

• 폴리머
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• 제33권5호
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• pp.413-419
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• 2009

프리즘 시트의 프리즘 층 물질의 굴절률을 증가시킬수록 휘도가 향상되어 LCD 백라이트 유닛의 효율이 향상되었다. 프리즘 층의 굴절률을 증가시키기 위해서 방향족을 포함하고 있는 고굴절 물질과 다관능성 반응물을 혼합하여 자외선 경화형 수지를 제조하였다. 9,9-Bis [4-(2-acryloyloxyethoxy)phenyl] fluorene을 반응시켜 프리즘층의 도막 굴절률을 1.58까지 증가시켰고 백라이트의 휘도를 향상시킬 수 있었다. 백라이트 유닛에 사용되는 광원에 장기간 노출될 경우 프리즘 시트에 황변현상이 발생하게 되어 휘도가 감소되므로 자외선 안정제로 hindered amine light stabilizer를 사용하여 프리즘 시트의 내황변성을 크게 향상시켰다.

• 한국분말재료학회지
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• 제27권3호
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• pp.233-240
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• 2020

Nano-sized ZnSe particles are successfully synthesized in an aqueous solution at room temperature using sodium borohydride (NaBH₄) and thioglycolic acid (TGA) as the reducing agent and stabilizer, respectively. The effects of the mass ratio of the reducing agent to Se, stabilizer concentration, and stirring time on the synthesis of the ZnSe nanoparticles are evaluated. The light absorption/emission properties of the synthesized nanoparticles are characterized using ultraviolet-visible (UV-vis) spectroscopy, photoluminescence (PL) spectroscopy, and particle size analyzer (PSA) techniques. At least one mass ratio (NaBH4/Se) of the reducing agent should be added to produce ZnSe nanoparticles finer than 10 nm and to absorb UV-vis light shorter than the ZnSe bulk absorption wavelength of 460 nm. As the ratio of the reducing agent increases, the absorption wavelengths in the UV-vis curves are blue-shifted. Stirring in the atmosphere acts as a deterrent to the reduction reaction and formation of nanoparticles, but if not stirred in the atmosphere, the result is on par with synthesis in a nitrogen atmosphere. The stabilizer, TGA, has an impact on the Zn precursor synthesis. The fabricated nanoparticles exhibit excellent photo-absorption/discharge characteristics, suggesting that ZnSe nanoparticles can be alloyed without the need for organic solutions or high-temperature environments.

• 한국지반신소재학회논문집
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• 제2권3호
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• pp.25-38
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• 2003

적용환경에 대한 저항성을 향상시키기 위하여 자외선 안정제로 카본블랙을 첨가한 재활용 폴리에스테르 지오텍스타일과 폴리프로필렌 지오텍스타일을 니들펀칭법에 의해 복합형 지오텍스타일을 제조하였다. 역학적 특성, 자외선 저항성 및 화학적 안정성을 측정하였다. 폴리프로필렌 지오텍스타일의 인장강도 보유율은 자외선 노출조건에 따라 50% 정도 감소하였지만 복합형 지오텍스타일은 약간의 감소를 나타내었다. 재생 폴리에스테르 지오텍스타일을 많이 사용할수록 자외선에 대한 안정성이 향상되었다. 화학적 안정성의 경우, 다양한 화학조건에서 복합형 지오텍스타일의 인장강도 변화는 -20~+10% 정도이었다.

• 한국지구과학회지
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• 제23권1호
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• pp.52-58
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• 2002

A colorless and transparent zirconium oxide ($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stockbager method. The gem-quality material is produced by adding 20${\sim}$25 wt.% $Y_2O_3$ (stabilizer) and 0.04 wt.% $Nd_2O_3$ (decolorising agent) to the $ZrO_2$ powder. It shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value and specific gravity is measured to be 8${\sim}$$8{\frac{1}{2}}$ and 5.85, respectively. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria-stabilized zirconia with 0.27 at.% Y has been re-investigated, using single crystal X-ray diffraction, and confirmed to be a cubic symmetry, space group $Fm{\overline{3}}m$ ($O^5_h$) with a=5.1552(5) ${{\AA}}$, V=136.99(5) ${{\AA}}^3$, Z=4. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of ${\Delta}/a{\sim}$0.033 and 0.11 along <110> and <111> from the ideal positions of the fluorite structure, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.50-53
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• 2008

In this work, the $TiO_2$ pigment influence in HDPE dielectric strength was analyzed. Chemical and structural characterizations were made to identify changes during the processing and your influence in the electrical properties. Formulations containing 0, 0.5, 1, 2.5, 4 and 6 of titanium dioxide were processed by extrusion and injection molding with stabilization-antioxidants, ultraviolet stabilizers and plasticizers. The electrical strength tests were analyzed by the statistical distribution of Weibull, and the maximum likelihood method. The high concentrations present lower values to electrical strength. The $\beta$ parameter could be using to insulator particles dispersion. The $TiO_2$ concentration variation shows that these incorporations implicate strength values increase has a maximum (5,35MV/cm). High pigment concentration induces a little falls in property values. Observing the $\beta$ parameter, minimum experiment electric field (Ebmin) and electric strength value, found that the best electric perform formulation was the formulation with 2.5% $TiO_2$ weight.

• 폴리머
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• 제39권1호
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• pp.1-5
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• 2015

The effects of zeolite on the thermal stability of poly(vinyl chloride) (PVC) were investigated by the static thermal stability test, pyrolysis experiment and ultraviolet spectrum. The results showed that the porous zeolite could absorb hydrogen chloride (HCl), which suppressed the catalysis of HCl on thermal degradation of PVC, thus improved the thermal stability of PVC. The oxidizing acid which was loaded on zeolite had oxidated on the double bond that formed during the dehydrochlorination of PVC. This process could prohibit the growth of the conjugated polyene and improved the color of PVC. Hence, zeolite might be possible to come up with a high performance thermal stabilizer.

• 한국소음진동공학회논문집
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• 제22권11호
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• pp.1099-1105
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• 2012

Transparent noise barrier panels have the advantages of transmitting light to nearby residents and allowing drivers to orientate themselves by providing views of the surrounding area. To develop guidelines on quality criteria for transparent soundproof panels, their sound transmission loss and weatherability were experimentally investigated. In Korea, the sound transmission loss of noise barrier panels should be more than 25 dB at 500 Hz and 30 dB at 1000 Hz. The transmission loss tests of transparent panels were performed in accordance with KS F 2808. Typically, plastic materials suffer from color changes when exposed to ultraviolet(UV) light over extended periods. Therefore, weathering of plastics is one of the most important properties for outdoor applications. Protection against UV radiation and weathering is usually accomplished by using UV stabilizer additives or coatings. Transparent materials for soundproof panels were examined through accelerated weathering tests and their weathering resistances were evaluated from changes in yellowness index.

• 한국전기전자재료학회논문지
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• 제19권5호
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• pp.457-460
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• 2006

Y doped zinc oxide (YZO) thin films were deposited on F doped $SnO_2$ (FTO) glass substrate by sol-gel method using the spin-coating system. A homogeneous and stable solution was prepared by dissolving acetate in the solution added diethanolamine as sol-gel stabilizer. YZO films were obtained after preheated on the hot-plate for 5minute before each coating; the number of coating was 3 times. After the coating of last step, annealing of YZO films performed at $450^{\circ}C$ for 30 minute. In order to confirming of a ultraviolet ray interruption and down-conversion effects, optical properties of YZO films, transmission spectrum and fluorescent spectrum were used. Also, for understanding the obtained results by experiment, the elestronic state of YZO was calculated using the density functional theory The results obtained by experiment were compared with calculated structure. The detail of electronic structure was obtained by the discrete variational Xa (DV-Xa) method, which is a sort of molecular orbital full potential method. The density of state and energy levels of dopant element were shown and discussed in association with optical properties.

• 한국식품과학회지
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• 제32권1호
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• pp.50-55
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• 2000

수용성 methyl-hesperidin(MH)분말을 원료 MH로부터 제조하였으며, 천연색소의 안정화를 검토하였다. 원료 MH (8%)를 중류수와 혼합한 다음 $45^{\circ}C$에서 24시간동안 교반하여 용해시켰고, 분말 활성탄으로 탈색한 다음 0.45m 막여과를 통해 정제하였다. MH분말을 0.1 또는 0.2%농도로 riboflavin, bixin, 그리고 paprika oleoresin색소용액에 첨가하여 10에서 24시간 동안 자연광에 노출시킨 후 색소용액의 흡광도를 측정하였다. 수용성 MH를 첨가하지 않은 색소용액은 시간 경과에 따라 완전히 퇴색된 반면 MH를 첨가한 경우는 색소의 퇴색을 지연시켰다. 대체로 수용성 MH의 첨가량이 증가함에 따라 더욱 우수한 색소 안정화 효과를 나타내었다. 특히, paprika색소용액에서 수용성 MH와 함께 첨가한 비타민 C는 자연광에 노출시 8시간까지는 뚜렷한 상승효과를 나타내었다. 상기 결과를 통해 수용성 MH는 태양광의 자외선에 대해 우수한 색소 안정화제로서 작용함을 알 수 있었다.