• Resources Recycling
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• v.10 no.5
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• pp.8-15
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• 2001

Aluminum dross should be recycled in consideration of characteristics of the dross and its reutilization after processing. In this study, aluminum dross generated in the domestic secondary aluminum industry was processed to use it as raw material for producing aluminum hydroxide. Sample dross was classified according to its size. The dross smaller than $850\mu$m was leached with sodium hydroxide solution to extract the remaining aluminum from the dross into the solution, and then aluminum hydroxide precipitate was recovered (rom the leach liquor. Purity of the obtained aluminum hydroxide was above 98% and size of the sample was in range of $\3~39mu$m. Recovery of aluminum hydroxide precipitate was highest on condition that A/C ratio of the solution was 0.5 and pulp density was 14~16% at the leaching step. From the result, it was suggested that this process could be applicable to recycling of aluminum dross.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.11 s.158
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• pp.1581-1588
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• 2006

The effects of removal of lignin or hemicellulose on the cottonizing and pulping characteristics of kenaf fiber were studied by comparing the conditions of non-cellulosic material contents, fiber lengths and dyeability. And the effects of lignin or hemicellulose on dyeability of the kenaf fiber using CI Direct Green 26 and CI Direct Red 81 were investigated. The results were as follows. The lignin contents decreased and the kenaf fiber became shorter and finer as the reaction time with sodium chlorite increased. The hemicellulose could be removed by treating sodium hydroxide solution to the fiber from which the lignin partly removed. The 80% of hemicellulose could be removed by 5% of sodium hydroxide solution in 5 minutes. But if lignin were not removed at all, hemicellulose could not be removed. The fiber lengths proper for apparel were obtained after treating sodium chlorite for 10-20 minutes and those for pulping were obtained after treating sodium chlorite for 40 minutes. The kenaf fibers from which lignin and hemicellulose partly removed were dyed with CI Direct Green 26 and CI Direct Red 81. Their dyeability increased as the removal rates of lignin increased. The ${\Delta}E$ values of kenaf fiber dyed with CI Direct Green 26 were lower than CI Direct Red 81.

• Fibers and Polymers
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• v.7 no.2
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• pp.186-190
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• 2006

The application of a degassing system to mercerization process was investigated. It was found that the physical properties of cotton fabrics mercerized in the degassed NaOH solution were superior to those mercerized in NaOH solution. The degree of penetration of the degassed water was examined by measuring wicking height. The wicking height in the degassed water without the wetting agent is higher than that of the saturated water with 0.1 % of wetting agent.

• Nuclear Engineering and Technology
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• v.8 no.3
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• pp.159-168
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• 1976

Acrylic acid has been grafted onto nylon fabric with ceric salts and ${\gamma}$-rays from Co-60 as initiators. The distribution of molecular weight of the grafted polyacrylic acid has been determined and it was found that the ratio of weight-average and number-average molecular weight was higher in room temp. than in low temp. (-184$^{\circ}C$). The weight-average molecular weight of the polyacrylic acid was calculated from viscosity measurements in sodium hydroxide solution. The factors affecting graft polymerization of acrylic acid onto nylon were examined. A possible mechanism that the oxidation of nylon probably takes place at the methylene group attached to nitrogen to give a free-radical was discussed.

• Journal of Environmental Health Sciences
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• v.21 no.2
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• pp.68-74
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• 1995

The optimum conditions was synthesized for the formation of Magnetite ($Fe_3O_4$) by air bubbling with the suspensions obtained by mixing Ferrous sulfate ($FeSO_4\cdot 7H_2O$) and Sodium Hydroxide (NaOH) solution in various values equivalent ratio($R=2NaOH/FeSO_4$) were studied. The changes of the structure were measured with XRD, $EM and BET. Equivalent ratio R: 0.65 was synthesized Goethite ($\alpha$-FeOOH), which becomes Maghemite ($\gamma=Fe_2O_3$) by dehydration, reduction and oxidation process. At the equivalent ratio over 1 (R>1), Magnetite ($Fe_3O_4$) was synthesized directly. The oxygen-deficient Magnetite ($Fe_3O_{4-\delta}$), which is obtained by flowing $H_2$ gas(100 ml/min) through the synthesis Magnetite at 350$\circ$C for 4 hr. By using it, was researched the decomposition reaction of $CO_2$. $CO_2$ was decomposed nearly 100% in 45 minutes by the oxygen-deficient Magnetite.

• Journal of the Korean Home Economics Association
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• v.32 no.1
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• pp.229-238
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• 1994

The purpose of this study was to investigate the objectification of coloring matter abstraction of the way to natural dye by cathamus flower. Watersoluble carthamin in the dyeing cathamus flower was removed for the fastness of dyeing and only insoluble carthamon was abstracted which came by solvent such as Sodium hydroxide(NaOH) Potassium hydroxide(KOH) Sodium carbonate(Na2CO3)and Potassi-um carbonate(K2CO3) Carthamon made abstract essence from a carthamus flower out of the pH6, pH7, pH9, pH11, solvent and by using a UV/VIS Spectra according to the change of pH. Silk dyes with solution abstract carthamon and it was treated by 5 kinds of mordant. The table of surface-colors was measured by the number of dyeing the color of silk dyed and by the kind of mordant which treated with and the dyeing was evaluated by measuring Color Fastness to Light and Washing.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.6
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• pp.1-7
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• 2014

Dissolving part of xylan and lignin in lignocellulosic biomass by base can be used as pretreatment technique. Cork oak was pretreated with sodium hydroxide solution and the pretreatment effects were evaluated with two critical factors - NaOH concentration and pretreatment temperature. Some of xylan and lignin were removed by base pretreatment. At $90^{\circ}C$ and 13% NaOH pretreatment, 22.0% of lignin and 78.8% of xylan removed by base treatment. Enzymatic hydrolysis of cork oak which was pretreated at higher temperature or concentration was further improved. After pretreatment of cork oak with 13% NaOH at $90^{\circ}C$, the conversion rate of cellulose to fermentable sugars were reached up to 91.3%. At ethanol fermentation with enzymatic hydrolysate from different pretreatment conditions, all enzymatic saccharification liquids were well fermented by Saccharomyces cerevisiae.

• Journal of Electrochemical Science and Technology
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• v.8 no.2
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• pp.146-154
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• 2017

In this study, copper (II) oxide was prepared for use in a copper electroplating solution. Copper chloride powder and copper (II) oxide are widely used as raw materials for electroplating. Copper (II) oxide was synthesized in this study using a two-step chemical reaction. Herein, we developed a method for the preparation of copper (II) oxide without the use of sintering. In the first step, copper carbonate was prepared without sintering, and then copper (II) oxide was synthesized without sintering using sodium hydroxide. The optimum amount of sodium hydroxide used for this process was 120 g and the optimum reaction temperature was $120^{\circ}C$ regardless of the starting material.

• Textile Coloration and Finishing
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• v.32 no.3
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• pp.135-141
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• 2020

The primary and secondary alcohols in cellulose reacted with acrylonitrile(AN) in the presence of strong alkalis to form cyanoethylated cellulose. The partially cyanoethylated cotton(CEC) fabric with AN in the presence of aqueous sodium hydroxide solution was described, including effects of treatment time and reagent concentrations. The weight increases of cotton fabric were shown to be linearly related to the treatment time, temperature and concentration of sodium hydroxide. The physical properties such as shrinkage ratio and tensile strength were proportional to the weight increases without significant impact on elongation. But the moisture regain decreased with decreasing hydrophilicity. The degree of substitution(DS) and transfer ratio were linearly related to the weight increases. In the CEC with increasing weight up to 24.9%, it has been obtained with DS up to 0.63-0.67 cyanoethyl groups per anhydroglucose and transferring ratio up to 87.7%. The color fastness to washing by sublimation transfer printing was improved by the cyanoethylation.

• Analytical Science and Technology
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• v.17 no.6
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• pp.527-531
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• 2004

Treatment with aqueous sodium hydroxide solution plays an important role to impart certain desirable properties - feel and luster on the surface of polyester fiber. In this process alkali wastewater contains disodium terephthalate, ethylene glycol (EG) and residual sodium hydroxide. In this paper we report a new method containing the pretreatments of derivatization with benzoyl chloride and solvent extraction using pentane. The calibration curve of EG determined by GC/MS-SIM shows a good linearity in the range of 0.1 to $25{\mu}g/mL$ having the standard deviation of ${\leq}8.7%$. The recovery and the detection limit of this method are 91.9-93.7% and $0.05{\mu}g/mL$ respectively.