• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.81-87
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• 2015

Soda-AQ pulp made from sugarcane bagasse (SCB) were bleached in element chlorine free (ECF) sequence. To reduce chlorine dioxide use, final peroxide bleaching was introduced. Prior to peroxide bleaching, different chelating chemicals were applied for comparative analysis in ISO brightness and viscosity. When using equal total chlorine dioxide usage (4.5%), bleached SCB pulp using chelate and hydrogen peroxide (DEDQP) was reached 86.8% (DTPA), 86.4% (EDTA) ISO brightness, whereas bleached pulp using only hydrogen peroxide (DEDP) reached at 81.2% ISO brightness. Viscosity of DEDQP bleached pulp was 25.6 cPs (DTPA), 25.2 cPs (EDTA), And DEDP bleached pulp was shown 18.0 cPs viscosity. Decreasing of transition metal by chelate process led to improvements in final brightness along with higher viscosity. Due to EDTA is 5-7 times cheaper than DTPA, EDTA is recommended as chelating chemical prior to peroxide bleaching.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.65-74
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• 2000

This study was carried out to acquire basic data necessary for the use of rice-straw chemical pulp. It investigated the proper bleaching conditions when rice-straw chemical pulps(alkaline sulfite-Na2S2O4 pulp) were bleached with the various kinds of bleaching agents. And physical properties of bleached pulps were tested. The results of this study were as follows; 1, The proper conditions of chlorine sequence were determined to be 4% concentration of chlorine 25$^{\circ}C$ of reaction temperature and 50 minutes of reaction time. 2. For calcium hypochlorite sequence the proper conditions of chemical concentration reac-tion temperature and reaction time were 3% 25$^{\circ}C$ and 20 minutes respectively. 3. For chlorine dioxide sequence the proper conditions were 1% concentration of chlorine dioxide 70$^{\circ}C$ of reaction temperature and 2hr. of reaction time. 4. The proper conditions of hydrogen peroxide sequence were 1.5% concentration of hydro-gen peroxide 70$^{\circ}C$ of reaction temperature and 1hr. of reaction time respectively. 5. When the rice-straw chemical pulp were bleached with four kinds of bleaching agents methioned above in the proper conditions respectively brightnesses were the order of chlorine dioxide calcium hypochlorite, chlorine, hydrogen peroxide. And strengthes of pulps bleached with chlorine dioxide and hydrogen peroxide were higher than those of pulps bleached with other bleaching agents.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.56-57
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• 2001

In Experiment 1, two hundred eighty 32wks old ISA brown layers were assigned to seven dietary treatments for 4weeks. Each treatment was consisted of 4 replications with 10 birds per replication. Control diet was formulated 10%CP 2,750KcalME/kg. Euglena bleached(DHA enriched) at the level of 0.5, 1.0, 2.0% in the diet. In Experiment 2, three hundred 84wks old ISA brown layers were assigned to seven dietary treatments: T1; Control, T2; T1 ＋ Euglena bleached(DHA enriched)0.5%, T3; T1 ＋ Euglena gracilis(DHA enriched)0.5%, T4; T1 ＋ Euglena gracilis(DHA enriched)1.0%, T5; T1＋Euglena gracilis(DHA enriched)2.0%. In Experiment 1, 2.0% Euglena bleached treatment showed highest DHA level in Egg yolk(P＜0.05). In Experiment 2, 0.5% Euglena bleached treatment showed highest DHA level in Egg yolk(P＜0.05).

• Journal of the Korean Society of Clothing and Textiles
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• v.36 no.8
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• pp.875-884
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• 2012

Many Koreans have recently bleached their black hair to blond or a light color due to the influence of their favorite Korean idols. Bleaching effects were studied under various bleaching conditions, such as the concentration of oxidants, the ratio between bleach accelerant and oxidant, and treatment temperature and time. The degree of damage of bleached hair with the same color difference (${\Delta}E$) intervals was observed in SEM images, the retention of breaking load and the change of color after dyeing. The ratio between bleach accelerant and oxidant of 1:2.5 was an effective condition. $L^*$ values of the bleached hair treated with 9% oxidant increased to 90 min. At a treatment temperature of $30^{\circ}C$, $a^*$ values were maximum at 30 min and then decreased as time further increased; however, $b^*$ values of the bleached hair increased as the treatment time increased. At $45^{\circ}C$, both of $a^*$ and $b^*$ values showed a maximum at a specific time. Bleaching efficiency was influenced most by temperature, followed in order by time, and oxidant concentration. As the treatment time increased, $L^*$ values greatly increased with twice treatment; however, $a^*$ and $b^*$ values decreased. Bleached hair, which had a color difference of higher than 30, showed the scales were completely removed and the retention of the breaking load greatly decreased. Highly bleached hair showed a great decrease in $L^*$ values by dyeing; however, dyeing with bright colors was more indicative to the effect of bleaching.

• The korean journal of orthodontics
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• v.43 no.3
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• pp.141-146
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• 2013

Objective: Bonding forces of brackets to enamel surfaces may be affected by the procedures used for bleaching and enamel etching. The aim of this study was to investigate the bonding strength of orthodontic brackets to laser-etched surfaces of bleached teeth. Methods: In a nonbleached control group, acid etching (group A) or Er:YAG laser application (group B) was performed prior to bracket bonding (n = 13 in each group). Similar surface treatments were performed at 1 day (groups C and D; n = 13 in each subgroup) or at 3 weeks (groups E and F; n = 13 in each subgroup) after 38% hydrogen peroxide bleaching in another set of teeth. The specimens were debonded after thermocycling. Results: Laser etching of bleached teeth resulted in clinically unacceptable low bonding strength. In the case of acid-etched teeth, waiting for 3 weeks before attachment of brackets to the bleached surfaces resulted in similar, but not identical, bond strength values as those obtained with nonbleached surfaces. However, in the laser-etched groups, the bonding strength after 3 weeks was the same as that for the nonbleached group. Conclusions: When teeth bleached with 38% hydrogen peroxide are meant to be bonded immediately, acid etching is preferable.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.2
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• pp.36-45
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• 1997

Newly bleaching sequence using oxygen, ozone and hydrogen peroxide has introduced to avoid pollution hazards from chlorinated organic compounds, because chlorine dioxide substitution bleaching was produced a little chlorinated organic substance. Oxygen-type chemicals replaced for chlorine has attracted much research attention. Bleachability of ozone was improved at low temperature and high pulp consistency. In third bleaching followed OZ bleaching, addition of O2 and NaBH4 in alkali extraction was effective than only alkali extraction. Bleachability of pulps in ozone bleaching(Z) was improved at higher consistency and lower temperature The addition O2 and NaBH4 in alkali extraction after OZ bleaching sequence improved brightness, when compared to those obtained by only alkaline extraction. Pulps bleached by ECF bleaching sequences such as OZEoD and OZEopD was obtained by 90% ISO brightness. The brightness of pulp bleached by TCF sequences with the ozone dosage of 1.6% was approached to target brightness (88~90%ISO). Pulps bleached Z stage combined bleaching sequence was reduced the viscosity to a little greater extent. However, physical properties of pulps was not great different compared to those bleached by conventional bleaching sequences. A pollution index of bleaching effluente by ozone combined bleaching sequences was lower than by conventional bleaching sequence, but somewhat higher than multistage bleaching sequences combined C/D stage.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.6
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• pp.979-993
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• 2016

Mongolian cashmere sliver, yarn, and fabric were dyed and bleached with a solution of ascorbic acid and iron sulfate at $70^{\circ}C$, and then dyed using natural indigo powder at the dyeing temperature of $25^{\circ}C$ to $90^{\circ}C$ for 15-90 minutes using the IR dyeing machine. K/S values of bleached samples decreased significantly when dyed above $70^{\circ}C$ dyeing temperature for a longer dyeing time. Bleached cashmere fabric showed a greater loss of tensile strength than unbleached cashmere fabric, even when the samples were dyed at $40^{\circ}C$. With a higher dyeing temperature, yarns lost fullness, became thinner, and the pores between the yarns were enlarged. The x-ray diffraction pattern exhibited a prominent increase in crystallinity and the protein assay indicated a loss of protein in the bleached sample dyed at $90^{\circ}C$. Thinning of scales, fractured or raised tip of scales, and roughness on the entire surface of the fiber were also observed. The results indicate that bleaching and high temperature dyeing cause a serious damage to cashmere fibers. In addition, bleaching and high temperature dyeing cause significant fiber damage. Natural indigo dyeing using low temperature dyeing is recommended to produce blue color cashmere.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.37-43
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• 2001

The bleach efficiency between PY and YP bleaching of pulps, which were deinked in neutral (cellulase) and alkaline (NaOH, NaOH/${Na_2}{SiO_3}$) ranges, and were treated on kneader, was compared in this study. The brightness of pulps (84.8~88.4% ISO) which were deinked in alkaline or neutral ranges increased up to 88.4%~88.8% ISO after PY or YP bleaching. There was no difference in the brightness between PY and YP bleaching. And the dirt count of bleached pulps was similar each other at the range of 17~38 ppm. The tensile index of bleached pulps was slightly higher in PY bleaching than those in YP bleaching. While with the treatment of kneading, the brightness and dirt count decreased remarkably compared to those of no-kneading. However, the sharp difference in the brightnesses or in dirt count of bleached pulps decreased after bleaching. The brightness of bleached pulps at YP stages was only numberically higher than those at PY stages without regard to the treatment of kneading. Therefore, in the case of the neutral deinkiing process, the conversion of PY bleaching stages to YP bleaching stages was profitable to water loop system, and was harmless in the aspect of the bleach efficiency.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.4
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• pp.30-36
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• 2002

This research was conducted to investigate the feasibility of using deinked pulp of white ledger(DIP) for the manufacture of high quality premium tissue. The three types of tissues were prepared using the softener treated bleached DIP, softener treated mixed pulp of unbleached DIP and virgin pulp, and untreated mixed pulp of bleached DIP and virgin pulp, respectively, and their tensile index. softness, and brightness were measured and compared. The bulk and surface softness increased only slightly by the addition of softener(0.2% mineral oil) into the bleached DIP. The tensile index was decreased by 15∼30%, and the brightness was the range of 86% to 87% ISO. The softener(0.2∼0.8% mineral oil or dialkyl imidazoline) treatment of mixed pulp of unbleached DIP and virgin pulp Improved the bulk and surface of tissue considerably. However, the brightness was low as 85% ISO or below. Although the softness of the tissue made from bleached DIP blended with virgin pulp was the lowest among three types of tissues evaluated, its tensile index was the highest and brightness was 87∼88% ISO. Based on the results, it may be predicted that the bleached DIP blended with virgin pulp is the best raw material for the manufacture of high quality premium tissue if softener treatment is applied to mixed pulp, because the softness can be improved by the addition of softener. In general, the softness of tissue was improved with the increase in the amount of softener: However, the tensile index inversely proportional to the amount of softener added. Dialkyl imidazoline was more effective than mineral oil with respect to the improvement in softness, even though the loss in tensile index was severe with the treatment of dialkyl imidazoline.

• Journal of Convergence for Information Technology
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• v.11 no.3
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• pp.212-219
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• 2021

The current study aimed to find the effects of hair treatment with shea butter on bleached hair and hair protection. The agent for hair treatment with shea butter was developed in different concentration levels (0%,1%,3%,5%) for experimentation. After applying the agent to bleached hair, hair samples were evaluated as follows. Increase in hair thickness was highest in the hair sample that had 5% of shea butter. The amount of amino acids was also highest in the hair sample that contained 5% of shea butter. Comparing the difference of the surface color, hair sample with 5% of shea butter showed low level of L⁎ while the level of a⁎ value that reflects the redness was high and the level of b⁎ value that reflects yellowness was low. Observation through the scanning microscope confirmed the positive effects by showing smoother surfaces in the sample with shea butter than in the bleached hair. This study showed shea butter is considered to be cosmetics to protect damaged hair by bleaching.