• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.73-79
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• 2001

Stricter environmental demands have increased the need to replace conventional C/D bleaching sequence by chlorine-free sequence. Permanganate is well known as a powerful oxidant and have been used industrially in variable fields. However, it has considered to be difficult to use permanganate as a bleaching reagent because of its strong oxidative effect decreasing the viscosity of pulps extremely. We have tried to use permanganate as a bleaching reagent for KP under the mild condition and it was clear that pernanganate oxidized lignin remained in pulps selectively and increased pulp brightness decreasing K number of pulps with small degradation of cellulose. We have employed the neutral condition in the permanganate bleaching process in this study. In this case, permanganate was converted to manganese dioxide after bleaching reaction. The manganese dioxide is remained in the treated pulp fibers because of its insolublity in water. So it was required to reduction the manganese oxide to manganese ion by using reductants with acid. In this paper, we proposed to use oxalic acid as a reducing reagent converting manganese oxide to manganese ion after bleaching reaction. Oxalic acid plays the role as a reductant and a acid, so post-treatment after bleaching became to be easy by using oxalic acid. On the study using lignin model compounds, it was clear that permaganate react with phenols firstly, after that oxalic acid reduce the manganese oxide to manganese ion in the mixture of permanganate, phenols and oxalic acid. Several lignin model compounds ($\textit{p}$-hydroxybenzaldehyde, vanillin, syringaldehyde, veratraldehyde) are selected to elucidate the effect of substituents on reaction rate and its mechanism with permanganate including oxalic acid in this study. Except for veratraldehyde, the rate of oxidative degradation of phenolic compounds by permanganate with oxalic acid are higher than neutral condition. Especially, the degradation rate of $\textit{p}$-hydroxybenzaldehyde are strongly dependent on pH of reaction mixture. On the other hand, the degradation rate of veratraldehyde are decreased with decreasing pH and main degradation product is veratric acid. This result indicate that pH of bleaching liquor should be kept over 2 to degrade of non-phenolic lignin in the pulps effectively in permanganate bleaching.

• International Journal of Oral Biology
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• v.43 no.2
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• pp.83-91
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• 2018

Nonthermal atmospheric plasma has been studied for its many biomedical effects, such as tooth bleaching, wound healing, and coagulation. In this study, the effects of dentinal tubules occlusion were investigated using fluoride-carboxymethyl cellulose (F-CMC) gel, nano-sized hydroxyapatite (n-HA), and nonthermal atmospheric plasma. Human dentin specimens were divided to 5 groups (group C, HA, HAF, HAP, and HAFP). Group HA was treated with n-HA, group HAF was treated with n-HA after a F-CMC gel application, group HAP was treated with n-HA after a plasma treatment and group HAFP was treated with n-HA after a plasma and F-CMC gel treatment. The occlusion of dentinal tubules was investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS), which shows Ca/P ratio. In the EDS results, a higher Ca/P ratio was shown in the groups including n-HA than in the control group. The specimens of group HAP and HAFP had a higher Ca/P ratio in retentivity. In the SEM results, there was not a significant difference in the amount of times applied. Therefore, this study suggests F-CMC gel and n-HA treatment using nonthermal atmospheric plasma will be a new treatment method for decreasing hypersensitivity.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.111-116
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• 2001

Waste office paper, photocopied or laser printed, has recently increased along with office automatization. In waste office paper, toner ink is used as the printing medium in place of conventional oil ink. Since toner ink cannot be saponificated by alkali and be decolored by bleaching, different from the case of oil ink, toner remains on regenerated paper as black specks. Although cascade recycling of waste office paper is compelled at present, the demand for low-grade paper is limited. From such circumstances, a new separation process for waste office paper is demanded to achieve parallel recycling. At the first stage of separation studies, the sharpness of separation is evaluated using small separators to obtain fundamental data. In a lab-scale separator, the sample amount of one feed is generally a few grams. However, the sample amount used for brightness, ERIC, and image analysis that are generally used to evaluate the efficiency of deinking are not small for lab-scale tests of these analyses. This paper describes an investigation of a sheet preparation method by a small amount of sample under 0.5g and compares the precision of toner content determination of spectroscopic analysis and image analysis from the viewpoint of separation evaluation. The easiness and convenience of the operation using only general-purpose equipments has also been set as a principle purpose. From the viewpoint of an analysis that yields high precision with a small amount of sample in short time, the method calculating the absorption coefficient from diffuse reflectance in the visible region is the most rational method in this study.

• Journal of Convergence for Information Technology
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• v.10 no.4
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• pp.175-183
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• 2020

The change in the demand and perception of wigs worn for hair loss is getting better, but hair extension is emerging as a new treatment method that improves as there are inconvenient areas such as hair loss, bleaching, and tangling of wigs themselves, and time spent on unnatural hair styling and wearing wigs. The purpose of this study is to verify that the quality of life of middle-aged female hair loss is positively affected by hair growth techniques that weave wool strands into their hair. Those surveyed were middle-aged women with hair loss and were analyzed by measuring the quality of life before and after hair growth. The analysis showed that hair increased techniques affects the economic satisfaction, physical satisfaction, mental satisfaction and social satisfaction of middle-aged women with hair loss, indicating that hair increased techniques is effective in improving the quality of life for middle-aged women with hair loss. It is also expected that the beauty industry will develop high value through hair increased techniques, a blue ocean in the beauty market.

• Journal of Fashion Business
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• v.26 no.2
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• pp.15-27
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• 2022

The purpose of this study is to perform research of ecology concepts expressed in fashion and to propose a new ecology fashion design based on the results. As a specific research method, first, to determine the concept of ecology, the contents related to ecology were extracted and organized through literature research, and then a fashion collection research was conducted to acquire basic design data, such as silhouettes, materials, details, and colors. From WGSN, and a total of 57 images were selected and used as basic data for the design suggestions. As a result of collecting the collection images, it was found that cotton or denim fabrics were mainly used, and in particular, the frequency of use was high mainly for bright tones. The use of chambray, lace, and wrinkles, was also frequent, and the use of expression techniques using burn-out, bleach, and bleaching effects or parts, or entire dyeing was often noticeable. The colors showed neutral and pastel-toned characteristics, and the silhouette was mainly composed of long silhouettes centered on maxi, such as a top or calf based on the knee, rather than a mini. Fabrics for the final designs were linen and sappan wood, and they were used for the dye and red was used as the overall color. The silhouettes were simplified, and care was taken to prevent unnecessary waste, such as paper or materials, from being generated during the production stage. We tried to achieve the purpose of eco-logy by refraining from excessive trimming, except for essential subsidiary materials, such as zippers.