• Textile Coloration and Finishing
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• v.13 no.2
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• pp.120-127
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• 2001

In order to make a microfiber fabric with PET/Co-PET Sea-Island Type microfiber, the optimum condition of extraction and elimination of Co-PET from the mocrofiber was examined. At the same time, the physical property change of the fabric with respect to the change of the relative amount of the Co-PET in the microfiber was also examined to provide a directly applicable data set to the industry. The sample fabric used was warp 75/36(DTY) and weft 0.05d(PET/Co-PET, Sea Island Type Microfiber) twill fabric of 36 separated yarns＋40/24(high shrinking yarn) with 130/48 ITY. The data set was made at various NaOH concentrations and steam temperatures with time as a main variable. The physical properties examined were the tensile properties. The results obtained were the tensile. The results obtained were 1. For a proper extraction of Co-PET (13.5%)from the microfiber with wet curing, it takes more than 5 min. in 8 and 12% of NaOH solutions but it takes only 3 min. in 18% of NaOH solution at 12$0^{\circ}C$. 2. For a proper extraction of Co-PET (13.5%) from the microfiber with wet curing, ti takes 3~5min. in 12 and 14% of NaOH solution and it takes less than 3 min. in 18% of NaOH solution at $130^\circ{C}$. 3. The increasing ratio of WT increased with increasing NaOH concentrations and the equilibrium point reached was 3 min. at $120^\circ{C}$. 4. The WT increasing ratio was greater in 14 and 18% NaOH solutions than in 8 and 12% of NaOH solutions at $130^\circ{C}$5. The RT ratio changes at $120^\circ{C}$ in 8 and 12% of NaOH solutions were indifferent from that at $130^\circ{C}$ in 12% of NaOH solution. However, the RT was apparently decreased with increasing NaOH concentration.

• Textile Coloration and Finishing
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• v.13 no.2
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• pp.34-34
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• 2001

In order to make a microfiber fabric with PET/Co-PET Sea-Island Type microfiber, the optimum condition of extraction and elimination of Co-PET from the microfiber was examined. At the same time, the physical property change of the fabric with respect to the change of the relative amount of the Co-PET in the microfiber was also examined to provide a directly applicable data set to the industry. The sample fabric used was warp 75/36(DTY) and weft 0.05d(PET/Co-PET, Sea Island Type Microfiber) twill fabric of 36 separated yarns＋40/24(high shrinking yarn) with 130/48 ITY. The data set was made at various NaOH concentrations and steam temperatures with time as a main variable. The physical properties examined were the tensile properties. The results obtained were the tensile properties. The results obtained were 1. For a proper extraction of Co-PET (13.5%)from the microfiber with wet curing, it takes more than 5 min. in 8 and 12% of NaOH solutions but it takes only 3 min. in 18% of NaOH solution at 120℃. 2. For a proper extraction of Co-PET (13.5%) from the microfiber with wet curing, it takes 3∼5 min. in 12 and 14% of NaOH solution and it takes less than 3 min. in 18% of NaOH solution at 130℃. 3. The increasing ratio of WT increased with increasing NaOH concentrations and the equilibrium point reached was 3 min. at 120℃. 4. The WT increasing ratio was greater in 14 and 18% NaOH solutions than in 8 and 12% of NaOH solutions at 130℃. 5. The RT ratio changes at 120℃ in 8 and 12% of NaOH solutions were indifferent from that at 130℃ in 12% of NaOH solution. However, the RT was apparently decreased with increasing NaOH concentration.

• Korean Chemical Engineering Research
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• v.48 no.3
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• pp.322-326
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• 2010

Stability of sodium borohydride solution during storage was studied. In order to enhance the $NaBH_4$ stability, NaOH and KOH were added to the $NaBH_4$ solution. The effect of concentration of the borohydride and alkaline solution, temperature and materials of storage vessels on the rate of borohydride hydrolysis was investigated. The rate of hydrogen evolution decreased as the concentration of alkaline increased due to increase of $NaBH_4$ stability in the solution. The stability of $NaBH_4$ solution decreased when the borohydride concentration raised from 10 to 15 wt% and then increased when the $NaBH_4$ concentration increased above 15 wt% due to increase in the pH of the concentrated solution. The activity coefficient of hydrolysis of $NaBH_4$ solution(NaOH 3.0 wt%, $NaBH_4$ 25 wt%) was 115.1 kJ/mol and this value was 1.5~4.0 times higher than that of hydrolysis of $NaBH_4$ solution with catalyst. The borohydride solutions in glass and stainless-steel vessel were more stable than the solution in plastic(PE) vessel.

• Analytical Science and Technology
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• v.14 no.6
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• pp.522-529
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• 2001

Carbon monoxide was generated when the saccharides which contained aldehyde group were added to alkali solution (NaOH solution) at $25^{\circ}C$ or $40^{\circ}C$. When the milk was added to 1.0 M NaOH solution at $25^{\circ}C$ and to 0.01 M NaOH solution at $40^{\circ}C$, carbon monoxide was generated. The carbon monoxide gas which was generated by 20 mL of 0.1 M lactose or 0.1 M xylose and 2 mL of 1.0 M NaOH solution at $50^{\circ}C$ for 2days was bubbled through 2 mL of fresh blood. The carboxyhemoglobin concentrations of both conditions were 31%. However, when the carbon monoxide gas which was generated by 30 mL of milk and 2 mL of 1.0 M NaOH at $50^{\circ}C$ for 2days or 3days was bubbled through 2 mL of fresh blood, the carboxyhemoglobin concentration was 32% or 42% respectively.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.117-126
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• 2012

This study carried out on the manufacturing of pidan. The production of pidan can be one of solutions for over-produced eggs and stable egg price. For the alkali-pickling solution for manufacturing of Pidan, the tested concentration of NaOH and NaCl were respectively as 3, 5, 7% and 5, 10, 15, 20%, and examined every 2 days for 14days. According to the results, pH value of alkali-pickling solution was increased by the increment of NaOH concentration and the pickling period, and was decreased by the increment of NaCl concentration. The pH value of egg yolk was increased by the increment of NaOH concentration, but it was not significantly different by the NaCl concentration. By the increment of NaOH and NaCl concentrations, the alkali infiltration in egg yolk and egg white was accelerated. Furthermore, the weight change of the eggs in the alkali-solution has no effects on manufacturing of Pidan. Liquefied albumen showed significant differences by NaOH concentration rather than that of NaCl. There was no liquefied albumen for 14days at 3% of NaOH, but it was found between 11-12days at 5% and 8-10days at 7%, respectively. The pH values of egg white when it was liquefied albumen were between 11.8 and 12.0. Pidan was made by heat treatment after 6-7days dipped in the solution at the concentration of 7%, about 10days at 5%, and 12-14days at 3% of NaOH, respectively. Although, the period of manufacturing of Pidan was saved by the increment of NaOH concentration, liquefied albumen was accelerated and the food preference was decreased by ammonia odor. Therefore, the suitable concentration of NaOH is between 3 and 5%, and that of NaCl is between 5 and 10% due to the effect of salinity by the soaking period. Through this study, optimal pickling solution and dipping time for manufacturing of Pidan was figured out, and also find out that it can save a time about 15days for manufacturing of Pidan.

• Resources Recycling
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• v.28 no.2
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• pp.54-61
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• 2019

In order to recover pure alumina from black dross, leaching of mechanically activated black dross with NaOH solution resulted in an aluminate solution containing a small amount of Si(IV). Selective adsorption of Si(IV) onto hydrotalcite was investigated from 5 M NaOH solution where the concentration of Al(III) and Si(IV) was 13000 and 150 mg/L, respectively. Only Si(IV) was selectively loaded onto hydrotalcite, while Al(III) remained in the solution. Effect of the calcination treatment of hydrotalcite and concentration of calcined hydrotalcite and NaOH on the loading of Si(IV) was investigated. Although the loading percentage of Si(IV) was low from 5 M NaOH solution, most of the Si(IV) was removed by adjusting the concentration of NaOH by 48 times dilution with water when the concentration of calcined hydrotalcite was higher than 4.5 g/L. The loading of Si(IV) onto calcined hydrotalcite followed Freundlich adsorption isotherm.

• Journal of Electrochemical Science and Technology
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• v.3 no.4
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• pp.185-189
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• 2012

A.c. impedances of mechanically polished CP-Ti specimens were measured at open-circuit potential (OCP) with immersion time and under applied anodic potentials between -0.2 and 1 $V_{Ag/AgCl}$ in 0.1 M NaOH solution. Capacitances of native oxide films ($C_{ox,na}$) grown naturally and capacitances of anodic oxide films ($C_{ox,an}$) formed under applied anodic potentials were obtained to examine the growth of native and anodic oxide films in 0.1 M NaOH solution and how to use $C_{ox,na}$ for the surface area measurement of Ti specimen. $1/C_{ox,na}$ and $1/C_{ox,an}$ appeared to be linearly proportional to OCP and applied potential ($E_{app}$), with proportional constants of 0.086 and 0.051 $uF^{-1}\;V^{-1}$, respectively. The $C_{ox,na}$ also appeared to be linearly proportional to geometric surface area of the mechanically polished CP-Ti fixture specimen, with proportional constants of 11.3 and $8.5{\mu}F\;cm^{-2}$ at -0.45 $V_{Ag/AgCl}$ and -0.25 $V_{Ag/AgCl}$ of OCPs, respectively, in 0.1 M NaOH solution. This linear relationship between $C_{ox,na}$ and surface area is suggested to be applicable for the measurement of real surface area of Ti specimen.

• Journal of the Korean Chemical Society
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• v.16 no.4
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• pp.241-248
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• 1972

The adsorption of Methylene Blue on Yeong-Il bentonite which was treated by aqueous NaOH, $Na_2SO_4 or NaHSO_4 solution respectively, varying concentrations, temperature and time, was studied. In case of treatment with NaHSO_4 solution, slight improvement of the adsorption of Methylene Blue on bentonite was observed. With Na_2SO_4$ solution, the best results obtained when bentonite was treated with 1 N of the solution for 2hr at $100^{\circ}C$, and the adsorption capacity of the product was 3 times better than that of original bentonite. At the higher concentration and the higher temperature than above, faujasite was formed. With NaOH solution, the best condition was in 1N solution for 1hr at $100^{\circ}C$ and the adsorption capacity of the product was 3.3 times better than that of original bentonite. At the higher concentration of the treating agent and at the higher temperature than above, hydroxysodalite was formed.

• Korean Chemical Engineering Research
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• v.49 no.6
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• pp.810-815
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• 2011

Concentrated water discharged from seawater desalination process contains a high concentration of $Na^+$ ion. Electrolysis was applied to synthesize NaOH solution from the highly concentrated NaCl solution. The effect of various operating parameters of composited laboratory-scale chlor-alkali (CA) membrane cell was investigated. The operating parameters such as membrane types (CIMS and Nafion membranes), pretreatment of the membrane, flow rate (73 mL/min~200 mL/min), initial $Na^+$ ion concentration (1.5 M, 3M and 5 M) and current (1.5A and 2A) were evaluated. It was observed that synthesis efficiency of NaOH solution with CIMS membrane was higher than that with Nafion membrane, but the durability of CIMS membrane on $Cl_2$ gas was poor. The synthesis efficiency of NaOH solution increased with increasing initial $Na^+$ ion concentration and current, while the efficiency decreased with increasing flow rate using Nafion membrane.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1500-1502
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• 1998

Electro Discharge Machining (EDM) is a so-call nonconventional machining technique. This paper presents the experimental results of an EDM technique for the fabircation of microholes on #7440 pyrex glass substrates. With various applied voltages and various concentration of NaOH or KOH solution, the glass substrates have been microdrilled using the copper electrodes of which diameters are 250 ${\mu}m$ to 450 ${\mu}m$. The machined throughholes have been observed the top diameter, the bottom diameter and machining time have been measured. EDM in NaOH solution causes the fabrication to have better the surface condition, higher selective of electrode, lower concentration of solution with respect to EDM in KOH solution machined fabrication.