• Textile Coloration and Finishing
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• v.17 no.5 s.84
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• pp.1-12
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• 2005

Polyester fibers can be modified into cationic dyeable polyester fibers(CDP) by the copolymerization of terephthalic acid and 5-sodium sulphoisophthalic acid with ethylene glycol. The advantage of CDP on most cationic dyes is the conspicuous brilliance due to a narrow steep absorption band and the wash fastness and etc. Weight reduction by alkali hydrolysis, dyeing and solvent wicking properties of fabrics with cationic dyes, and change of fine structure were investigated. To obtain optimum splitting process parameters for dyeing and physical properties of micro CDP fiber, splitting method under various conditions was carried out. By means of SEM, it was confirmed that the splitting process of the micro CDP fiber be achieved at the weight reduction. A comparatively greater quantity of dye is necessary to dye microfiber than conventional fiber. The fastness and solvent wicking of regular CDP fiber is higher than that of micro CDP fiber.

• International Journal of Industrial Entomology and Biomaterials
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• v.48 no.2
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• pp.86-97
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• 2024

Alkaline- or salt-assisted extractions have been widely used to extract edible insect proteins, however, there is a need for extraction techniques that balance cost-efficient production as well as preserving the protein properties. Mealworm proteins (Tenebrio molitor larvae) were extracted using three different extraction methods-alkali (AMP), salt (SMP), and water (WMP)-and then physicochemical and techno-functional properties were examined. AMP had high yield, protein, and amino acid contents, whereas WMP had high moisture, ash, and fat contents. SDS-PAGE showed a wide range of molecular weights in WMP whereas mostly low molecular weights were observed in AMP and SMP. AMP had poor protein solubilities compared to SMP and WMP across all pHs. AMP had enhanced water-holding capacity and emulsion stability, whereas WMP had improved oil-holding capacity and foaming properties. WMP formed a gel with and without the transglutaminase. The physicochemical and techno-functional properties demonstrated that water-soluble mealworm protein was superior to alkali-and salt-soluble mealworm proteins. Considering the cost efficiency and minimal impact on the environment as well, a cold press juicer could be utilized for mass production of mealworm protein compared to the conventional methods of protein extraction using alkali and salt.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.2
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• pp.85-93
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• 2013

This study has been carried out to elucidate the characteristics of the dissolution for Thermal Decomposed Solid Waste of uranium-bearing sludge (TDSW), the removal of impurities by an alkalization in a nitric acid dissolving solution of TDSW, and the selective removal (/recovery) of uranium by an acidification in an carbonate alkali solution, respectively. TDSW generated by thermal decomposition of U-bearing sludge which was produced in the uranium conversion plant operation, was stored in KAERI as a solid-powder type. It is found that the dissolution of TDSW is more effective in nitric acid dissolution than oxidative-dissolution with carbonate. At 1 M nitric acid solution, TDSW was undissolved about 30wt% as a solid residue, and uranium contained in TDSW was dissolved more than 99%. In order to the alkalization for the nitric acid dissolving solution of TDSW, carbonate alkalization is more effective with respect to remove the impurities. At the carbonate alkali solution controlled to about 9 of pH, Al, Ca, Fe and Zn co-dissolved with U in dissolution step was removed about $98{\pm}1%$. On the other hand, U could be recovered more than 99% by an acidification at pH about 3 in a carbonate alkali solution, which was nearly removed the impurities, adding 0.5M $H_2O_2$. It was found that uranium could be selectively recovered (/removed) from TDSW.

• Journal of the Korean Society of Industry Convergence
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• v.20 no.4
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• pp.257-263
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• 2017

The following thesis researched into the characteristics of electrolytic ion water with different levels of electrical conductivity by adding NaCl into tap water which is for experimental use in multi-layered electrolytic ion water generator. Electrolytic ion water is generated by underwater electrolysis and the electrolysis generator has a simple structure, is easy to control and is highly utilized in industries. Electrolytic ion water is useful in many areas since it has a superior sterilizing power, has no possibility of secondary pollution itself as water and removes active oxygen. In the experiment, we used tap water with NaCl excluded and water with three different levels of electrical conductivity by changing NaCl concentration levels into three levels. The features of current and voltage in electrolytic ion water represented a form of quadric instead of the linear characteristic following ohm's law. As well, as the electric conductivity of water and applied voltage increased, we were able to generate much stronger acid water and alkali water.

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.53-58
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• 2001

Sulfonated poly(phenylene sulfide) (SPPS) polymers were prepared by sulfonation of poly[methyl[4-(phenylthio) phenyl]sulfonium trifluoromethanesulfonate] (PPST) with fumic sulfonic acid (10% $SO_3-H_2SO_4$) and demethylation with aqueous NaOH solution. The equilibrium constants of ion exchange reactions between alkali metal cations ($Li^+,\;Na^+,\;and\;K^+$) and SPPS ion exchanger in organic solvents such as tetrahydrofuran (THF) and dioxane were measured. The equilibrium constants of ion exchange reactions increased as the polarity of the solvent increased, and the reaction temperature decreased. The equilibrium constants of the ion exchange reaction ($K_{eq}$) also increased in the order of $Li^+,\;Na^+,\;and\;K^+$. To elucidate the spontaneity of the exchange reaction in organic solvents, the enthalpy, entropy, and Gibbs free energy were calculated. The enthalpy of reaction ranged from -0.88 to -1.33 kcal/mol, entropy ranged from 1.42 to 4.41 cal/Kmol, and Gibbs free energy ranged from -1.03 to -2.55 kcal/mol. Therefore, the exchange reactions were spontaneous because the Gibbs free energies were negative. The SPPS ion exchanger and alkali metal ion bounding each other produced good ion exchange capability in organic solvents.

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.278-279
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• 2011

• Journal of the Korea Institute of Building Construction
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• v.13 no.5
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• pp.457-464
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• 2013

Traditionally, the material used for the form in reinforced concrete construction has been wood or steel. But recently, aluminum forms have been widely used in wall structures such as apartment buildings. Aluminum is light, easy to handle, and economically advantageous, but the hydrogen gas created due to its reaction with the alkali component in concrete gives rise to air pockets on the concrete's surface, and deteriorates the surface's finishability. In this research, to determine the influence of aluminum material on concrete, the cement paste W/C and its chemical reactivity in alkali and acid solution were analyzed. As a prevention plan, the influence of the number of applications of calcium hydroxide and various surface coating materials was analyzed. Through the analysis, it was found that the surface voids on the aluminum form are the result of the reaction of hydrogen gas with an alkali such as $Ca(OH)_2$. This can be prevented by the surface treatment of $Ca(OH)_2$, separating material and coating material. However, poor surface form and damages to the form are expected to cause quality degradation because of the aluminum-concrete interaction. Therefore, thorough surface treatment, rather than the type of separating material or coating material, is considered the most important target of management.

• Journal of the Korean Chemical Society
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• v.12 no.4
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• pp.155-159
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• 1968

On the extraction of humic acid from peat, the optimum conditions were studied and the effects of them on the characteristics of humic acid were also examined by means of infrared spectroscopy. 1. Pretreatment of peat with diluted 6-8% HCl solution for 5 hrs. prior to extraction with alcohol-benzol azeotropic mixture have resulted the better yield of humic acid. The water soluble Na-humates were obtained by the subsequent extraction with one hundred times quantity of caustic soda solutieon for 1hr. at 90 $^{\circ}C$. Thus the pure humic acids have been yielded approximately 40% (by wt.) from the raw peat. 2. In characteristics of humic acid, the chemical structure, mainly the contents of such functional groups as -COOH, -OH (phenol type), $-CH_2CO-$, $-CH_2{\cdot}O{\cdot}CH_2-$ and aromatic rings were varied according to the concentration of alkaline solution, temperature and time when the humic acids were extracted with alkali.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.323-323
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• 2010

Saw damage of crystalline silicon wafer is unavoidable factor. Usually, alkali treatment for removing the damage has been carried out as the saw damage removal (SDR) process for priming the alkali texture. It usually takes lots of time and energy to remove the sawed damages for solar grade crystalline silicon wafers We implemented two different mixed acidic solution treatments to obtain the improved surface structure of silicon wafer without much sacrifice of the silicon wafer thickness. At the first step, the silicon wafer was dipped into the mixed acidic solution of $HF:HNO_3$=1:2 ration for polished surface and at the second step, it was dipped into the diluted mixed acidic solution of $HF:HNO_3:H_2O$=7:3:10 ratio for porous structure. This double treatment to the silicon wafer brought lower reflectance (25% to 6%) and longer carrier lifetime ($0.15\;{\mu}s$ to $0.39\;{\mu}s$) comparing to the bare poly-crystalline silicon wafer. With optimizing the concentration ratio and the dilution ratio, we can not only effectively substitute the time consuming process of SDR to some extent but also skip plasma enhanced chemical vapor deposition (PECVD) process. Moreover, to conduct alkali texture for pyramidal structure on silicon wafer surface, we can use only nitric acid rich solution of the mixed acidic solution treatment instead of implementing SDR.

• Journal of the Korean Chemical Society
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• v.39 no.5
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• pp.371-378
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• 1995

The triazacrown compound, 1,7-dioxa-4,10,13-triazacyclopentadecane trihydrobromide salt (Na3O2-3HBr) was synthesized. And this compound was used to synthesize the new ion exchanger, which combined with Merrifield peptide resin. This new ion exchanger had a capacity of 3.2 meq/g dry resin. And the distribution coefficients of alkali and alkaline earth metal ions on this ion exchanger in the various concentrations of hydrochloric acid were determined. The ion exchange behaviors of alkali and alkaline earth metal ions in the various hydrochloric acid concentrations are, also, discussed.