• Journal of the Korean Ceramic Society
• /
• v.12 no.2
• /
• pp.26-30
• /
• 1975

The experiment has been carried out to clarify the condition of acid treatment for preventing the crack formation caused by swelling and shrinking during acid leaching process. The borosilicate glass contained phosphorous pentoxide was chosen as the sample, which is recognized to be more homogeneous in phase separation. The various effects, such as kind, cocentration and acid temperature, were investigated. The experimental results are summerized as follows. (1) Sulfuric acid is more stable than hydrochrolic acid for preventing the crack. (2) The optimum concentration of acid lies in the range of 0.1~0.3N. (3) Higher temperature of the acid to treat the separated glass was more stable than lower temperature. (4) The rate of crack decreased with the longer period and the higher temperature of the heat treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.04a
• /
• pp.67-68
• /
• 2008

A simple bi-layer structure of organic light emitting diode (OLED) was used to study the characteristics of anode preparation. Indium tin oxide (ITO) anode surface treatment of OLEDs was performed to get the optimum condition for the ITO anode. The ITO surface was treated by $O_2$ or $O_2$ / Ar mixed gas plasma with different processing time. The electrical characteristics of OLED were improved by plasma treatment. The operating voltage of OLED with $O_2$ or $O_2$/Ar mixed gas plasma treated anodes decreases from 8.2 to 3.4 V and 3.2V, respectively. The $O_2$ /Ar mixed gas plasma treatment results in better electrical property.

• Proceedings of KOSOMES biannual meeting
• /
• 2004.11a
• /
• pp.105-108
• /
• 2004

Organic acid is made with carbonized organic acid that is produced from charcoal burning process. It is evaluated whether carbonized organic acid is able to removed Enteromorpha in the laboratory and Porphra aquaculture farm test. The optimum condition for Enteromorpha removal are revealed ten times dilution and ten second immersion. The mortality rate of Enteromorpha is $95\%$ and diatom-detaching rate is $100\%$ by the organic acid treatment. On the other hand, the mortality rate of Porphra is lower than $5%\$. It was measured that nitrogen was 0.175 mg/l and phosphorus was 0.0158 mg/l. Therefore, Concentration of nutrients were lower than being necessary to Porphra growth. Growth rate of Porphra was $12\%$ increased by organic acid treatment with carbonized organic acid added nutrient.

• Textile Coloration and Finishing
• /
• v.7 no.3
• /
• pp.44-52
• /
• 1995

Cotton and cellulosic other fabrics, such as rayon, polynosic, and linen were treated with liquid ammonia, and then were treated with cellulase after or before dyeing, as well as in the presence of dye. Dyeing was carried out with C. I. Direct Blue 1 at 5$0^{\circ}C$, for 6hr in the case of rayon, and 24hr in the case of cotton, polynosic, and linen. The optimum condition of cellulase was at 55$^{\circ}C$, pH 4~5. Weight loss of fabrics were increased by the liquid ammonia treatment and it was predominant when they were treated with cellulase alone and in the presence of dye. Changes of color strength of the cotton, polynosic, and linen were increased by liquid ammonia treatment compare with untreatment. Especially, in the presence of dye, K/S value of the liquid ammonia-treated fabrics were nearly the smae as untreated.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2000.02a
• /
• pp.85-88
• /
• 2000

Cu-free Bi-Sr-Ca-O powder mixtures were screen-printed on Cu tapes and heat-treated at 850-$870^{\circ}C$ for several minutes in air, oxygen, nitrogen and low oxygen pressure. Cu-free precursors were composed of Bi_{x}$SrCaO_{y}$ (x=1.2-2). In order to obtain the optimum heat-treatment condition, we studied on an effect of the precursor composition, the printing thickness and the heat-treatment atmosphere on the superconducting properties of Bi2212 films and the reaction mechanism of their rapid formation. Microstructures and phases of thick films were analyzed by optical microscope and XRD. The electric properties of superconducting films were examined by the four probe method. At heat-treatment temperature, the thick films were in a partially molten state by liquid reaction between CuO in the oxidized copper tape and the precursors which were printed on Cu tapes.

• Journal of Korea Foundry Society
• /
• v.23 no.2
• /
• pp.69-76
• /
• 2003

The present work was undertaken to investigate the mutual effect of the individual melt treatment commonly applied in aluminum foundries such as grain refining, modification, degassing and filtration on the microstructures and the mechanical properties. A357 alloys were fabricated through various melt treatments such as degassing by gas bubbling filtration, modification via the addition of Al-Sr master alloy, grain refining through the addition of Al-Ti-B master alloy and filtration before pouring of the melt. Each melt treatment was performed at its optimum condition reported in the literatures. The effects of each melt treatment and their interactions on the microstructures and mechanical properties of A357 alloy were examined.

• Journal of the Korean Society for Heat Treatment
• /
• v.11 no.1
• /
• pp.27-34
• /
• 1998

Effects of different heat treatments on microstructure and damping capacity of Cu-55%Mn alloy were investigated to find an optimum heat treatment condition for a maximum damping capacity. The alloy showed the high level of damping capacity in case of the aging at 375 and $400^{\circ}C$. This is ascribed to the FCC${\rightarrow}$FCT martensitic transformation and microstructural changes from mottled to tweed band type. The damping capacity had a maximum value of 0.33 in logarithmic decrement when the alloy was aged at $375^{\circ}C$ for 14 hours followed by 20 times of thermal cycling between room temperature and $250^{\circ}C$. The refinement of tweed structure by thermal cycling is thought to be responsible for the highest damping capacity.

• Textile Coloration and Finishing
• /
• v.13 no.1
• /
• pp.1-8
• /
• 2001

Amur cork tree is natural basic and yellow dye largely used for dyeing on cotton. The most effective solvent for extract of berberine from amur cork tree was methanol. The dyeabilities of the colorant on cotton and the fastness of cotton fabrics dyed with amur cork tree extract were investigated. And according to the concentration, temperature and time of pre-treatment, K/S values, wash fastness and Hand Value of cotton fabrics dyed with amur cork tree extract were investigated. As a results, K/S values of dyed cotton fabrics were increased by Pre-treatment with chinese gallotannin and the optimum condition of chinese gallotannin treatment was 15%owf concentration at $60^\circ{C}$, 30min. The wash fastness was enhanced to 3.5 grades. There was no degradations of Hand Value of cotton fabrics treated with chinese gallotannin.

• Journal of the Korean Ceramic Society
• /
• v.29 no.10
• /
• pp.785-790
• /
• 1992

A study of the pack cemcented SiC coating on graphite was performed and the process conditions were evaluated by means of experimental design. The content of Si, P2O5, B and Al2O3 reaction temperature, reaction time and acid treatment wast tested as the experimental variables. The results were analyzed and compared by the characteristic value of 10% weight loss by oxidation. The acid treatment exhibited the most effective anti-oxidation property and the optimum conditions were the powder composition of 20% Si, 3% B and 77% SiC, the reaction temperature of 1550$^{\circ}C$ for 7 hours with phosphoric acid treatment. The pack coating performed under this condition improved the 10% weight loss oxidation temperature by 514$^{\circ}C$ compared to the bare graphite.

• Korean Journal of Food Science and Technology
• /
• v.53 no.1
• /
• pp.92-98
• /
• 2021

The effects of heat-moisture treatment (HMT) on rice flour (RF) have been investigated for possibility of texture modifier in protein-based foods matrix, tofu. The optimum condition for preparation of tofu with maximum textural parameters was investigated by using response surface methodology (RSM). Rice flour was subjected to moisture content (10-30%) and heating temperature (100-140℃). Based on the response surface and superimposed plots, the optimized conditions of hydrothermally treated rice flour was as followed: moisture content, 22%; temperature, 130℃, which showed lower swelling power as compared to native RF and became more stable during continuous heating and agitation than native one. Tofu, prepared with HMT-RF, showed a denser network structure than that with RF, thereby inducing an increase in textural parameters. From the above results, the addition of HMT-RF could preserve the quality of tofu and be useful for developing an acceptable protein-based food product.