• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.73-81
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• 2006

Heat treatment condition for the stabilization of foamed glass block through the foaming process of the hydrolized waste glass was investigated and scale-up test for the manufacturing of foamed glass was also attempted for the actual foaming process. Proper heat treatment condition was quenching from the foaming temperature to $550{\sim}600^{\circ}C$ for stabilization, and then annealing from stabilization temperature to $200^{\circ}C$ and holding up at $200^{\circ}C$ for removal thermal stress, and then annealing to the room temperature with cooling speed of $0.3^{\circ}C/min$. Through this heat treatment conditions, foamed glass block with size of $250mm{\times}250mm{\times}90mm$ was produced successfully. The properties of this foamed glass block showed density of $0.28{\pm}0.06g/cm^3$, thermal conductivity of $0.048{\pm}0.005kcal/hm^{\circ}C$, moisture absorption of $0.5{\pm}0.09vol%$, linear expansion coefficient of $(8.6{\pm}0.2){\times}10^{-6}m/m^{\circ}C$($400^{\circ}C$), flexural strength of $15.0{\pm}0.6kg/cm^2$, and compression strength of $39.5{\pm}0.6kg/cm^2$.

• Journal of Powder Materials
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• v.22 no.3
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• pp.187-196
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• 2015

With the stabilization of Korea's industrialization, it has become interested in the efficient use of rare metals, climate change and industrial environment and safety etc. It is thus making efforts to implement economic policies that address such issues. Therefore it is necessary to understand the demand, supply and use of metal materials. Since 2010, the Korean government has developed the integrated material flow methodology and has been trying to examine the demand, supply and use of metal materials. In 2013, the Korean government surveyed the material flow of chromium. Material flow analysis and environment emission of chromium were investigated 8 steps; (1) raw material, (2) first process, (3) Intermediate product, (4) End product, (5) Use/accumulation, (6) Collection, (7) Recycling, (8) Disposal. Chromium was used for stainless steel, alloy steel, coated sheets, refractory material and coating materials. Recycling was done mainly in use of stainless steel scrap. To ensure efficient use of chromium, process improvement is required to reduce the scrap in the intermediate product stage. In the process of producing of the products using chromium, it was confirmed that chromium was exposed to the environment. It requires more attention and protection against environment emission of chromium.

• Polymer(Korea)
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• v.34 no.4
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• pp.386-389
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• 2010

Thermal behaviors of water in the poly(acrylic acid) (PAA)/water mixtures with 0.1 M NaCl, HCl, and NaOH were investigated by DSC. It showed that adding ions in the mixtures affected the crystallization of water evidently. Compared with the PAA/water mixtures, the $T_m$ of freezable bound water in the mixtures with ions moved to lower values and varied with different cations and anions, due to the stabilization or destabilization of the hydrogen-bonding hydration between polymers and water molecules through ionic hydration. The content of non-freezable bound water in the non-crystalline phase of the PAA/water mixtures with ions was not constant, it increased with total water content gradually, owing to the more binding sites created by ions. The ions could change the distribution of different states of water in the polymer aqueous solutions evidently.

• Electrical & Electronic Materials
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• v.11 no.10
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• pp.40-45
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• 1998

This paper describes a collaborative work between SEI and KEPCO on the Superconducting Magnetic Energy Storage system (SMES). We have studied two types of magnets. One is the 400kJ class LTS-SMES for testing the power stabilization operated at liquid helium temperature (4.2K) and the other is the 100J class HTS-SMES for confirming the possibility of applying HTS wire to SMES at liquid nitrogen temperature (77k). In this paper, the design of the magnet and the test results are described. Each magnet performed completely at rated operation.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.10 no.1
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• pp.16-27
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• 2001

Composite resin have very important roles as a esthetic fillng material. Today we are confusing by a numerous number of the polymer options in the market. Are there any complications such as tooth sensitivity? Do they have stabilization in the long term aspect? These are the reasons why many dentists don't use composite resin in my country. But the problems can be overcome by choosing the best suited materials and meticulous clinical procedures. So that we are able to expand our clinical boundary. I would like to introduce the clinical techniques of Dr.Gordon Christensen in Utah, and overall clinical cases under the base of CRA newsletter.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.222-223
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• 2001

Optical parametric oscillator(OPO) has been used to generate coherent and tunable laser source with birefringent phase-matching technique in various nonlinear materials. In birefringent phase-matching, the output wavelength is controlled with angle or temperature tuning of the refractive index. However these tuning methods have several limitations such as restriction of tuning wavelength due to reasonable angular and temperature tuning ranges, Poynting vector walk-off which limits the interaction length, and thermal stabilization time. (omitted)

• Journal of the Korean Ceramic Society
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• v.33 no.7
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• pp.755-760
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• 1996

Sol-gel processing was used to prepare PZT fibers. Titanium isopropoxide Zirconium n-butoxide and lead acetate trihydrate were used as starting materials and TEA(triethanolamine) was added to form stabilized Pb-Ti-Zr complex alkoxide, Effects of catalysts and various solvents on the state of precursor sol gelation reaction fiber spinnability pyrolysis and crystallization were also investiated.

• Electrical & Electronic Materials
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• v.5 no.2
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• pp.237-243
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• 1992

무독성 혼합안정제인 Zn/Ca-stearate의 방사선 안정화 효과를 증진시키기 위해서 안정화 조제로 알코올들을 PVC에 배합하여 방사선 조사하였을 때 PVC의 색차변화를 측정하여 이들 안정화 조제의 방사선 안정화 효과를 비교 검토하였다. 2가알코올에 의한 PVC 안정화 효과는 2가알코올의 주쇄길이에 비례하여 나타나고 있으나 sorbitol을 제외한 다가알코올에 의한 PVC 안정화 효과는 거의 없는 것으로 나타났다. 이들 알코올에 의한 PVC의 방사선 안정화는 2가알코올이 PVC에서 발생된 고분자 라디칼에 대한 라디칼 포착제로서 작용하기 때문인 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.245-248
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• 1992

Polyethylene oxide (PEO) surfaces are recognized as having an effective steric stabilization character. A theoretical scaling analysis involves the osmotic and elastic coefficients of the polymer as a function of molecular weight, in a good solvent. The calculated results show that PEO in water may exhibit the greatest flexibility among water soluble polymers, probably due to its lowest elastic contribution.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.6
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• pp.217-221
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• 2005

The evaporation amounts of volatile Cd, Pb and Zn were characterized by measuring their total concentrations in the EAF dust-clay bodies with various mixing ratio and heat treatment temperature. TCLP test was conducted for evaluating the chemical stabilities of the heavy metal elements. Evaporation amounts and leaching concentrations of heavy metal components were strongly dependent on the mixing ratio and heat treatment temperature. The evaporation of the heavy metal components in EAF dust was effectively suppressed by increasing the clay content. The leaching concentrations of heavy metal components were decreased with increasing clay content and temperature. 20 wt% EAF dust-80 wt% clay sample shows nearly zero evaporation and leaching concentrations of heavy metal components. XRD analysis showed that peak intensities of major crystalline phases such as franklinite and quartz were decreased with increasing the heat treatment temperature which means that the stabilization mechanism of the heavy metals was related with the vitrification process of the $SiO_2$ in the clay.