• Textile Coloration and Finishing
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• v.12 no.6
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• pp.380-388
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• 2000

The porosity of polyester fibers treated with sodium hydroxide aqueous solution was investigated using a nitrogen porosimeter, and the dyeability of the treated fibers was discussed in terms of the porosity. In pore distribution, the polyester fibers treated with sodium hydroxide aqueous solution were characterized by higher amount of pores below $10\AA$ than those of the untreated fibers, and by shift of the pore size having maximum accumulated volume from $10\AA$ for the untreated fibers to $5~6\AA$. As the weight loss of the polyester fibers treated with sodium hydroxide aqueous solution increased, BET surface area and total pore volume increased linearly, but average pore size, showing some different aspect, increased steeply at earlier stage and then approached the maximum value. The dye uptakes of the polyester fibers treated with sodium hydroxide aqueous solution increased with the BET surface area, the total pore volume and the average pore size. The alkali treatment increased the surface area of polyester fibers, so that the chance of contact between the fiber and dye molecules increased. In addition, the pores created on the surface of polyester fibers by alkali treatment might act as pathways for dye molecules into the polyester fibers.

• Current Applied Physics
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• v.18 no.12
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• pp.1507-1512
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• 2018

The development of an organic-based aqueous redox flow battery (RFB) using quinone as an electroactive material has attracted great attention recently. This is because this battery is inexpensive, produces high energy density, and is environment friendly in stationary electrical energy storage applications. Herein, we investigate the redox potentials and solubilities of indole-5,6-quinone and indole-4,7-quinone derivatives in terms of the substituent effects of functional groups using theoretical calculations. Our results indicate that full-site substituted derivatives of indolequinone are more useful as active materials compared to single-site substituted derivatives. In particular, our calculations reveal that the substitution of $-PO_3H_2$ and $-SO_3H$ functional groups with multiple polar bonds is very effective in increasing the activity of the aqueous RFB. As a strategy to overcome the limitation that the aqueous solubility is intrinsically low because they are organic molecules, we suggest the substitution of functional groups with multiple polar bonds to the backbones of active organic materials. Among 180 indolequinone derivatives, 17 candidates that meet the redox potential standards ($${\leq_-}0.2V$$ or $${\geq_-}0.9V$$) and eight candidates with solubility exceeding 2 mol/L are identified. Three indolequinone derivatives that satisfy both conditions are finally presented as promising electroactive candidates for an aqueous RFB.

• Korean Chemical Engineering Research
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• v.60 no.3
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• pp.423-432
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• 2022

Magnetic biochar produced from pyrolysis of dairy cattle manure was used to develop an effective sorbent for arsenic purification from aqueous solution. Biomass and magnetized biomass were pyrolyzed in a tube furnace with 10 ℃/min heating rate at 450 ℃ under nitrogen flow of 100 cm³/min for 2 h. Biochars were characterized by SEM-EDX, BET, XDR, FTIR, TGA, zeta potential analysis. The resultant biochar and magnetic biochar were opposed to 50-100-500 ppm As(V) laden aqueous solution. Adsorption experiments were performed by using ASTM 4646-03 batch method. The effects of concentration, pH, temperature and stirring rate on adsorption were evaluated. As(V) was successfully removed from aqueous solution by magnetic biochar due to its highly porous structure, high aromaticity and polarity. The results suggest dairy cattle manure pyrolysis is a promising route for managing animal manure and producing a cost effective biosorbent for efficient immobilization of arsenic in aqueous solutions.

• YAKHAK HOEJI
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• v.30 no.5
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• pp.228-231
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• 1986

The effect of temperature and pH on the degrdation of minoxidil in the aqueous solution was investigated and the stability of pharmaceutical preparation for solution was also studied. The degradation of minoxidil in the aqueous solution was first order type reaction and the rate constant at $20^{\circ}C$ in pH 7.0 phosphate buffer solution was 9.464${\times]10^{-3} day^{-1}$ and calculated activation energy was 11.7 kcal/mol. The degradation of minoxidil was acid-base catalytic reaction and the most stable range of pH was about 5.0. The liquid pharmaceutical preparation was very stable in 3 months.

• Journal of the Korean Society of Safety
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• v.9 no.3
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• pp.67-73
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• 1994

The gas holdup and volumeteric liquid phase mass transfer coefficient with the variation of the concentration of CMC aqueous solution, gas velocity, diameter and area of the draught tube were investigated. As the results of the experiments, the gas holdup and volumetric liquid phase mass transfer coefficient decreased with decreasing the concentration of CMC aqueous solution, increased with increasing the gas velocity and increased with increasing the circulated area ratio of the draught tube.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.379-382
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• 2006

In this study, an attempt was made to form magnesium oxide layer via aqueous solution route of salt precipitation process. A layer with flake morphology was formed from the process and various dopants were added during the forming process. The films formed were characterized using SEM, XRD, and cathodoluminescence measurement. In addition, the discharge characteristics were evaluated using panel tests. The results indicate that MgO film can be formed via the aqueous solution process successfully, of which characteristics are comparable to those of MgO film formed by e-beam evaporation process.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.784-787
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• 2003

In this study, water jet etching of aqueous green tape was attempted for processing barrier rib of plasma display panel. This process combines 1) chemical etching between water and aqueous based binder in the tape and 2) mechanical erosion by water jet. Effects of etching parameters such as pressure, temperature and aqueous binder content on the morphology of barrier ribs formed were investigated. The results demonstrated a possibility of processing barrier ribs by water jet etching.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.771-777
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• 1998

Aqueous extracts of Pinus rigida changed the electrophoretic patterns of total proteins and of hydrolytic enzymes such as peroxidase, esterase and amylase during the germination of radish (Raphanus sativus var. hortensis for. acanthiformis). When the extract treatment was finished, at the late stage of radish germination, aqueous extracts of P. rigida had suppressed the expression of 24 KD and 60 KD proteins. the extract induced new isozyme bands, indicating concomitant activity of peroxidases, esterase activities were stimulated in the cathodic region. The activity of amylase was enhanced by the extract.

• Advances in environmental research
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• v.1 no.3
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• pp.211-221
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• 2012

Bromadiolone (BRD), a second generation anticoagulant often applied to the living environment to control rodents, is usually considered to have low environmental toxicity due to its poor solubility in water. In this study of the effect of humic acid (HA) on BRD using electronic absorption spectroscopy, it has been observed that BRD is appreciably solubilized even in low concentrations of aqueous HA solutions. The BRD solubilization efficiency of aqueous HA was found to be $2.39{\pm}0.14$ ($4.53{\pm}0.26{\mu}M\;ppm^{-1}$). It was also seen that BRD is reasonably solubilized in aqueous extract of farm soil.

• Journal of the Korean institute of surface engineering
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• v.24 no.3
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• pp.169-176
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• 1991

The pros and cons of deposition metals, alloys and compounds from organic, inorganic and molten salt non-aqueous plating baths are discussed. Although some metals, alloys and compounds not obtainable otherwise can be deposited, few commercial processes exist. Widespread use is limited by the cost, complexity, and hazards associated with non-aqueous electrolytes, coupled with the relatively small markets for many of these coatings.