• Korean Journal of Human Ecology
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• v.6 no.1
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• pp.27-34
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• 2003

We investigated the bacterial and chemical retting conditions of ramie grown in Hansan. Bacterial retting was done in troughs at a temperature of 30${\pm}$2$^{\circ}C$ for 1, 2, 3, 4, 5, 6 and 10 days. Chemical retting(CR) was done at the different conditions using sodium silicate (Na$_2$SiO$_3$), sodium carbonate(Na$_2$CO$_3$) and sodium hydroxide(NaOH) as alkali solutions. The retting solution was boiled during 1. 2, 4 and 6 hours respectively at the different concentration(0.5, 2.0, 4.0, 6.0. 8.0 %) with decorticated ramie stems submerged in it. The treated ramie was then rinsing with running tap water thoroughly, which was further soaker in 0.5% acetic acid (v/v) solution for three minutes and washed thoroughly with distilled water. Finally ramie was dried for 2 hours in vacuum oven at 100 $^{\circ}C$. To know change of ramie fiber characteristics retted at the different conditions, weight loss, fiber bundle strength were tested and color, texture, luster etc. were also sensually evaluated. The results were as follows. $.$ Weight loss of ramie retted in each alkali solutions were about 10%, 20% and 30% in sodium silicate, sodium carbonate and sodium hydroxide, respectively. $.$ Chemical retting was faster than bacterial retting, but the color of chemically retted ramies were worse than that of bacterially retted ramies. $.$ The combination of bacterial and chemical processing showed some merits. A combination of either 2 or 3 days of bacterial and then chemical retting might provide the best quality ramie. $.$ Ramie fiber became cottonized ramie when retted in 8% NaOH solution for 6-8hours.

• Journal of the Korean Wood Science and Technology
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• v.35 no.3
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• pp.79-87
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• 2007

This study investigated the effects of lacquer-finishing to prevent discoloration of coloring chestnut wood coated with natural dyes from deteriorating factors such as lights (indoor, 500 lux and outdoor, 50,000~70,000 lux), acid, alkali, and heat through measurement of color difference. Lacquer-finishing coating contributed to protection of intrinsic color of the natural dyeing woods in spite of severe treatment. In particular, dyeing liquor with alkali pH played a great role in prevention of light discoloration.

• Korean Journal of Food Science and Technology
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• v.28 no.3
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• pp.514-520
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• 1996

The purpose of this study was to develop the production technology of modified starch. Corn starches were gamma irradiated at 0-110 kGy and the effect of irradiation dose levels on the physicochemical properties of corn starches were investigated. Blue value linearly decreased, while alkali number and solubility markedly increased as irradiation dose levels were increased. The optical transmittance increased as applied irradiation dose levels were increased in the temperature range of $65-95^{\circ}C.$ Water binding capacity and swelling power showed maximum value at 30 and 10 kGy, respectively and they tended to decrease thereafter. Gelatinization viscosity of the gamma irradiated starch considerably decreased as compared to that of the non-irradiated starch. Irradiation at 110kGy resulted in a marked reduction of peak viscosity and cooling viscosity at $30^{\circ}C$ by 100 and 300 times, respectively. The physicochemical properties of corn starch irradiated at 30 kGy were similar to those of commercial acid-modified starch, while those of corn starch irradiated at 100 kGy were similar to those if oxidized starch.

• The Research Journal of the Costume Culture
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• v.14 no.2
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• pp.260-270
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• 2006

In this research, the curly dock was used in the process of dyeing for fabrics of the inner wear & the patient wear. Since the curly dock has a pharmacological effect on dermatosis, this study focused on the variety of color and functions of the inner wear fabrics & patient wear fabrics to make the best use of the pharmacological effect of curly dock. With regards to giving a variety of colors and functions in the inner wear, patient wear fabrics, the curly dock dye was used in each treatment conditions on the cotton & silk fabrics. After dyeing, the dyeability, color change, light fastness, washing fastness, perspiration fastness, antibiosis, far infrared emissivity and emission power were evaluated. The evaluation results are as follows; The dyeablity increased from repeated dyeing and, by using the mordant, variety of colors such as skin, mustard, greyish-brown and dark earth colors were conformed to the naked eye. Fe mordant was better than Al on the lightfastness and the washing fastness. The repeated dyeing was found out to have less effect on neither lightfastness nor washing fastness. Both silk and cotton fabrics were graded $3{\sim}4$, since their degree of degradation appeared to be the same in alkali perspiration and acidic perspiration. In the case of silk fabrics mordanted by Al, the rate of declining in both Staphylococcus aureus ATCC 6538 and Klebsiella pneumonia ATCC 4352 were 99.9%. In addition, the antibiosis was enhanced when the mordant was used. The far infrared was 86.6% of emissivity, $3.34{\times}10^2\;W/m^2{\cdot}{\mu}m$ emission power.

• Journal of the Korean Ceramic Society
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• v.56 no.6
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• pp.577-582
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• 2019

Recently, E-glass fiber is the one of most widely used ceramic fiber for aerospace fields. Recycling technology for waste of wind power blades is arising issue for reasons of low manageability and high cost of wastes. Though glass fiber is perfectly dissolved in hydrofluoric acid, low cost for recycling and harmless to human is important for recycling of blades. Chemically melted glass fiber will be used as different purpose like accelerator of hardening for shotcrete. In this study, dissolution process of glass fiber is tested in NaOH solution at low temperatures. In addition, difference in diameter reduction of glass fiber is observed by various alkali concentration and reaction times, treatment temperatures using FE-SEM.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.607-610
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• 2005

If cement can be manufactured with industrial byproducts such as granulated blast furnace slag(GBFS), phosphogypsum(PG), and waste lime(WL) instead of clinker as its counterproposal, there would be many advantages, including maximum use of these industrial byproducts for high value-added resources, conservation of natural resources and energy by omitting the use of clinker, minimized environmental pollution problems caused by $CO_2$ discharge, and reduction of the production cost. This research investigates the chemical resistance of NSC mortar added PG and WL to GBFS as sulfate and alkali activators. The result of experiment of chemical resistance, showed that NSC is very excellent in acid resistance and seawater resistanc. Such a reasons are that the hydrate like CSH gel and ettringite formed dense pore structure of NSC matrix.

• Journal of the Korean Applied Science and Technology
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• v.18 no.4
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• pp.298-305
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• 2001

Emulsified transesterification of soybean oil into biodiesel was investigated using potassium hydroxide and sodium methoxide catalysts with methyl glucoside oleic polyester as a methanol-in-oil emulsifier. The transesterification reaction conditions were optimized to obtain high yields of fatty acid methyl esters of the quality defined by biodiesel standards. The developed process resulted in $95{\sim}96%$ of overall yield from soybean oil by alkali-catalyzed methanolysis at $45^{\circ}C$ of reaction temperature with 6:1 of methanol-to-oil molar ratio and 1(v/v)% methyl glucoside oleic polyester in the presense of 0.8wt% KOH and 1.2wt% $NaOCH_{3}$.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.192-199
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• 2003

Trimethylglycine, commonly named betaine, is the most simple amphoteric molecule. It is completely vegetal (1,2), as it is produced in the sugar industry by industrial chromatography of molasses. While abundantly used in foods and diet supplements, many interesting applications in cosmetics have recently been investigated, like its capability to increase the volume and stability of foams in surfactant solutions. For its special chemical structure (it is the internal salt of a weak acid and a strong alkali) trimethylglycine is a solvent and buffering agent for strong acids and Lewis' acids. It allows to improve the efficiency of $\alpha$- and $\beta$-hydroxy acids in increasing the physiological rate of epidermal cell renewal, while keeping a low skin-irritation level. In oral care cosmetics, it acts as a mucous membrane protectant (3). For its special water co-ordination capability, its solubilising power, polymer swelling capability, after-feel improvement in hair products, skin moisturization and elasticity enhancing properties, trimethylglycine provides unusual characteristics to many products intended for skin maintenance (4).(omitted)

• Journal of the Korean Chemical Society
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• v.33 no.2
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• pp.177-184
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• 1989

Acidic properties of ZSM-5 zeolite catalysts were investigated by temperature-programmed desorption technique and ir spectroscopy. Ammonia t.p.d. pattern of HZSM-5 showed three different states, designated as ${\alpha}$,${\beta}$ and ${\gamma}$. The amount of ${\gamma}$-state decreased with increasing $SiO_2/Al_2O_3$ ratio, and upon cation-exchanging with alkali cations. From the ir adsorption spectra of absorbed pyridine and the reaction study of toluene alkylation, the ${\gamma}$-state could be explained to be due to the strong Bronsted acid sites of H-ZSM-5. Also they showed that the interaction between alkali cation-exchanged ZSM-5 and bases, i.e. $NH_3$ and pyridine, was increasing with decreasing the size of cations.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.357-361
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• 2001

The possibility of producing Cr$_2$O$_3$powder from waste magnesia-chromium refractory was investigated by sulfuric acid reaction, alkali fusion, water leaching & purification and heat treatment. The effects of temperature, the amount of NaOH added and the flow rate of air on chromium extraction efficiency in an alkali fusion step were investigated. The fusion product was leached with methanol to solve free-NaOH, and then leached with water to produce a Na$_2$CrO$_4$solution. The purity of chrome(Ⅵ) oxides, prepared both from monochromate with an impurity content and monochromate purified with $CO_2$were also examined. The purified monochromate solution was reduced from Cr(Ⅵ) to Cr(III) with NaHSO$_3$solution. The reduced solution was neutralized with NaOH to produce Cr(OH)$_3$. Water washing was treated to eliminate Na$_2$SO$_4$from neutralized Cr(OH)$_3$slurry. The washed Cr(OH)$_3$was dried and thermally treated to produce Cr$_2$O$_3$powder. The properties like lightness and hue of Cr$_2$O$_3$fabricated in this study were L=47.47, a=-14.40 and b=17.21.