• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.1
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• pp.1-9
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• 2008

This study examined the effect of an electrokinetic-flushing remediation for a soil of a high permeability. The soil was sampled from the site around a research atomic reactor which had high hydro-conductivities due to a high content of sand in the soil. The flow rate of the washing reagent was fast at the beginning but it was reduced as time lapsed. In the case of using citric acid as a washing reagent, the flow rate was fastest, 78.7 ml/day. The removal efficiencies of $Co^{2+}$ and $Cs^+$ from a soil cell with acetic acid were the highest, which were 95.2% and 84.2% respectively. The soil waste-solution volume generated from the electrokinetic remediation was reduced to about 1/20 of that from the soil washing remediation. Meanwhile, the electrokinetic-flushing method enhanced the removal efficiencies of $Co^{2+}$ and $Cs^+$ from the soil by about 6% and 2% respectively, compared to those by the electrokinetic method. Consequently, it was found that the electrokinetic-flushing method was more effective for the remediation of a soil with a high permeability.

• Journal of Environmental Impact Assessment
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• v.32 no.2
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• pp.112-122
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• 2023

To restore the ecological function of contaminated soil and maximize the ecological services provided by the soil, besides the toxicity orrisk caused by pollutants, the functional aspects of the soil ecosystem should be considered. In this study, a method for evaluating the health of cleaned soil was presented, and the applicability of the proposed evaluation method was examined by applying it to soil treated with washing and landfarming. Productivity, habitat, water retention capacity, nutrient cycling, carbon retention capacity, and buffering capacity were used as soil health evaluation indicators. The results showed that the soil health was not completely recovered after remediation, and even in the case of the washed soil, the health was lower than before remediation. On the other hand, there was no significant change in soil quality due to oil pollution, but soil health deteriorated. Unlike the slightly improved soil quality after landfarming treatment, soil health was not completely restored. Therefore, the results of this study indicate that it is desirable to consider both soil quality and health when evaluating the remediation effect. The soil health evaluation method proposed in this study can be usefully utilized for the sustainable use of cleaned soil and to promote ecosystem services.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.2 s.27
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• pp.133-144
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• 1988

Silk fabrics were degummed and dyed in one bath under the condition of high temperature and high pressure and the results obtained were summerized as follows. 1. The degumming ratio is nearly the same as that of two bath method under the normal condition and the optimal condition is for 30 minutes at $120^{\circ}C$. 2. The dyeing absorption ratio is a little lower than that of two bath method. 3. The tensile strength and elongation are hardly shown the difference between two methods. 4. The fastness of the dyed fabric of one bath method is a little better than that of two bath method. (light, washing, rubbing) 5. The stiffness of the silk fabric treated by one bath method is a little harshier compare to that of two bath method.

• Journal of Powder Materials
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• v.16 no.5
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• pp.336-341
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• 2009

To produce alloy powders with only Sm$_2$Fe$_{17}$ single phase by reduction-diffusion (R-D) method, the effect of excess samarium oxide on the preparation of Sm-Fe alloy powder during R-D heat treatment was studied. The quantity of samarium oxide was varied from 5% to 50% whereas iron and calcium were taken 0% and 200% in excess of chemical equivalent, respectively. The pellet type mixture of samarium, iron powders and calcium granulars was subjected to heat treatment at 1100$^{\circ}C$ for 5 hours. The R-D treated pellet was moved into deionized water and agitated to separate Sm-Fe alloy powders. After washing them in deionized water several times, the powders were washed with acetic acid to remove the undesired reaction products such as CaO. By these washing and acid cleaning treatment, only 0.03 wt% calcium remained in Sm-Fe alloy powders. It was also confirmed that the content of unreacted $\alpha$-Fe in Sm$_2$Fe$_{17}$ matrix gradually decreased as the percentage of samarium oxide is increased. However, there was no significant change above 40% excess samarium oxide.

• Journal of the Korean Society of Costume
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• v.60 no.7
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• pp.88-102
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• 2010

The research examines the characteristics of the sewing methods used for women's Jeogori in modern Korea. The results are following. In the 1920s sewing of shoulder parts was started, and in the 1930s sewing by hand had reduced by dissemination of sewing-machine, and in the 1940s the Som-jeogori declined by the matter of economic and sanitary issues. In the 1950s four-fold sewing emerged, and during the 1960s the gause-lined triple-layered Jeogori was in fashion, and in the 1970s the Ggaeggi-jeogori and much elaborated Jeogori became in vogue. The characteristics of the sewing methods are changed by following factors. First, the dissemination of sewing-machine in the 1930's enabled fast and precise sewing of Jeogori which reduced the rate of clothes mending and the production period. Second, by development of washing method, the dry cleaning became common, resulting cleaner washing and better preservation. Third, introduction of western clothes gave rise to modernized Han-bok which was changed into practical and simple one. Fourth, by the introduction of synthetic textile and industry development, Jeogori with no armhole line or right Seop line was made using wide selection of textiles. Fifth, in 1945~60s, women learned' good wife and wise mother' education and the use of sewing machine in school. The clothing lifestyle affected the sewing method's change, for example, clothes sewed strongly by sewing machine not to take clothes apart, and attaching button instead of Go-reum to save clothes.

• International Journal of Human Ecology
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• v.9 no.1
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• pp.17-27
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• 2008

Black garments can lose color, image, and be the main cause of color staining when washed with other laundry that can cause color contamination from interaction with other garments. To know the fiber-based dye fastness for colored garments, 4-5 pieces of various fibers of different fabrics were selected; cotton, linen, wool, silk, rayon, acetate, polyester, and nylon. To determine the colorfastness to washing and crocking, the black fabrics were washed with alkali and neutral detergents under the Laund-O-Meter method under the Crockmeter method. In an alkali detergent laundering conditions, most colored samples did not undergo color or light fastness. However, most of the stained fabrics slightly changed in K/S values while other samples underwent severe changes. With neutral detergent laundering, sample fabrics underwent less shrinking, and had less naps. The stained fabrics also underwent less change in K/S values. With time-repeatedly-washing the original sample went through colorfastness to lose color. In crocking fastness, most samples produced good to excellent results under dry conditions but produced relatively low crocking fastness under wet conditions. Natural fibers especially showed lower crocking fastness than artificial fibers. In conclusion, garments of the same color should be laundered together. The black garments that are washed using neutral detergents can decrease the amount of damage from color change. While it is the responsibility of garment producers to provide appropriate quality indications they should also provide adequate instructions for consumers to understand and appropriately cope with the quality indications in order to contribute to establishing a correct laundering method.

• Korean Journal of Materials Research
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• v.23 no.10
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• pp.543-549
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• 2013

The purpose of this paper was to investigate the effect of a high-energy milling (HEM) process on the particle morphology and the correlation between a thermal treatment and tetragonal/monoclinic nanostructured zirconia powders obtained by a precipitation process. To eliminate chloride residue ions from hydrous zirconia, a modified washing method was used. It was found that the used washing method was effective in removing the chloride from the precipitated gel. In order to investigate the effect of a pre-milling process on the particle morphology of the precipitate, dried $Zr(OH)_4$ was milled using a HEM machine with distilled water. The particle size of the $Zr(OH)_4$ powder exposed to HEM reduced to 100~150 nm, whereas that of fresh $Zr(OH)_4$ powder without a pre-milling process had a large and irregular size of 100 nm~1.5 ${\mu}m$. Additionally, modified heat treatment process was proposed to achieve nano-sized zirconia having a pure monoclinic phase. It was evident that two-step calcining process was effective in perfectly eliminating the tetragonal phase, having a small average particle of ~100 nm with good uniformity compared to the sample calcined by a single-step process, showing a large average particle size of ~300 nm with an irregular particle shape and a broad particle size distribution. The modified method is considered to be a promising process for nano-sized zirconia having a fully monoclinic phase.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.2
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• pp.105-116
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• 2019

Oil adsorption during hair or body washing is responsible for the hair conditioning. In this study, we established a method to extract oil from a substrate, and to determine amount of adsorbed oil upon substrate using a conventional absorption spectroscopy. We controlled the mole fraction of a surfactant in a mixture of anionic and amphoteric surfactants because that it induces the coacervate that regulates amount of adsorbed oil through the alteration of oil viscosity. Based on this, we established the optimized condition for adsorption and extraction for oil. UV absorbance were employed to estimate the amount of adsorbed oil using optical absorbance after extraction via adsorption. The estimation was confirmed by comparing with a mass analysis in HPLC and an adhesive energy in AFM. It has been proved that this method can be applied to all cases of oil adsorption from the results with various cationic polymers and a complex system of the polymers which regulate the oil adsorption.

• Journal of IKEEE
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• v.23 no.2
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• pp.543-551
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• 2019

Permanent Magnet Synchronous Motors(PMSMs) have a wider range of applications due to their high output density and high efficiency. PMSMs are used not only in high-power density, high-performance motor-driven systems such as vehicle and robots, but also in systems where cost-cutting is very important, such as washing machines, air conditioners and refrigerators. To reduce costs, position sensorless control is required, which is generally difficult to be used under conditions of starting the motor. Thus, the I-F speed control that rotates the current vector at any speed in the starting procedure should be used at first, and then the sensorless speed control could be applied after PMSM rotates above a certain speed. Speed control performance in I-F speed control and sensorless speed control is very important. And more speed control performance should be maintained even in the transient in which the two control techniques are changed. In this paper, the speed controller transition method from I-F speed control to sensorless speed control of permanent magnet synchronous motor is proposed. Experiments were carried out on the washing machine drive system to verify the performance of the proposed technique.

• Journal of Korean Society on Water Environment
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• v.40 no.1
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• pp.36-46
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• 2024

Microplastics in water resources have been recognized as a serious problem. The discharge of microplastics from wastewater treatment plants is considered a major contributor to environmental pollution in water resources. However, a reliable analytical method for quantifying microplastics in wastewater treatment plants has not yet been established. This study proposes a reliable, quick, and easy analytical method for quantifying microplastics. For the removal of organic particles, preprocessing steps were applied including oxidation, sonication, washing, and sieving. Nile Red staining was used to visualize microplastics, and quantitative analysis was conducted using fluorescent imaging. The stained microplastics were ultimately quantified through image analysis software. Among the preprocessing steps, sonication and washing stages were particularly effective in efficiently removing interfering substances from wastewater, enhancing the accuracy of the microplastic analysis. Additionally, various solvents (methanol, acetone, and N-hexane) for the Nile Red staining solution were tested. When N-hexane was applied as the solvent, the quantity of stained microplastics was lower compared to methanol and acetone. This suggests that N-hexane has a greater potential of reducing false staining and counting of non-plastic particles. In summary, this research demonstrates a robust method for quantifying microplastics in wastewater treatment plants by employing effective preprocessing steps and optimizing the staining process with Nile Red and N-hexane.