• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.1
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• pp.100-110
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• 2016

Alkaline Peroxide Mechanical Pulping (APMP) of Pinus densiflora harvested from domestic mountains was explored. APMP contributes to various advantages including pulp quality, elimination of the need for a bleaching process, and energy savings. Sequential treatment of impregnation of bleaching chemicals and refining not only overcome the concern of alkaline darkening of wood chips during chemical impregnation, but it also brightens the chips to the desired brightness levels suitable for writing and printing papers. APMP pulping from Pinus densiflora was greatly influenced by the dosage levels of hydrogen peroxide and sodium hydroxide. Alkaline peroxide treatment was carried out by applying one of three levels of hydrogen peroxide (1.5, 3, and 4.5% based on the oven-dried weight of the wood chips) and one of three levels of sodium hydroxide (1.5, 3, and 4.5% based on the oven-dried weight of the wood chips). Other chemicals including a peroxide stabilizers and metal chelation were constantly added for all treatments. Chemical treatment with a liquor-to-wood ration of 9:1 was carried out in a laboratory digestor. Compared to BTMP, APMP pulping displayed outstanding characteristics including the less requirement of refining energy, the better improvement of tensile strength, the more reduction of shives, and the greater increase of pulp brightness. In particular, when 4.5% of hydrogen peroxide with impregnation during 90 minutes was used, the brightness of APMP reached 64.9% ISO. Even though bulk of APMP was decreased with the increase of sodium hydroxide, a better and improved balance could be achieved between optical and strength properties. The spent liquor obtained from the discharge of the impregnation process at the dosage level of 4.5% hydrogen peroxide exhibited an equal level of residual peroxide with BTMP. In conclusion, APMP pulping showed successful results with Pinus densiflora due to its better response to the development of optical and physical properties compared to TMP pulping.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.266-272
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• 2013

Objectives: This study aimed to evaluate the effects of low-level exposure to toluene on T lymphocytes subpopulations.s. Methods: The study lasted from April to October 2010. The subjects were 390 male workers, among whom 137 were chronically exposed to toluene in video-tape manufacturing factories and 253 were controls had never been occupationally exposed to hazardous chemicals. The subpoupulations of CD4+, CD8+, CD16+ (natural killer cells) and total (CD3+) T lymphocytes were examined by two-color staining using monoclonal antibodies. The general and job characteristics of subjects were assessed through a self-administered questionnaire. Results: There was no significant difference in general and job characteristics between both groups. No significant difference in lipid peroxide level was observed between the control and exposed workers, but the concentration of hydrogen peroxide was significantly higher in the exposed workers. The numbers of CD16+ T lymphocytes in controls were significantly higher than those in exposed workers, but no significant differences were found in CD4+, CD8+ and CD3+ T lymphocytes. Hydrogen peroxide levels showed a significantly negative correlation with CD8+ (r = -0.29, p < 0.01), CD16+ (r = -0.56, p < 0.01) and CD3+(r = -0.22. p < 0.01), and toluene levels was significantly negative correlated with CD3+ (r = -0.29, p < 0.05). Conclusions: Our results suggest that chronic low-level exposure to toluene affects cell-mediated immunity and the effects might mediate through ROSs (Reactive Oxygen Species) such as hydrogen peroxide.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.90-95
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• 2005

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.1
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• pp.6-12
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• 2013

TFormic acid-hydrogen peroxide (or performic acid) pulping process needs milder reaction condition than other chemical pulping process. Two-step formic acid-hydrogen peroxide pulping process can produce the chemical pulp with similar pulp yield and lignin content compared with soda-anthraquinone process. Formic acid-hydrogen peroxide pulp can be produced less xylan content than other alkaline pulps, which favor for dissolving pulp production. Formic acid-hydrogen peroxide pulp showed better response beating than soda-anthraquinone(AQ) pulps with reaching target freeness with less beating. Also, formic acid-hydrogen peroxide pulp had better tensile index at similar freeness level compared with soda-AQ pulps.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.9_10 s.146
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• pp.1295-1305
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• 2005

The study was based on a three-stage, non-repetitive factorial experiment in which chemical-rotted kenaf fibers were treated separately with hydrogen peroxide concentrations of $0.5\%,\;1\%\;and\;2\%$, with pH solutions of 7, 9 and 11, and treatment times of 30, 60 and 90 minutes. Under optimal conditions, the study was conducted to determine the bleaching efficiency by the addition of chelators, penetrants and surfactants. The bleaching effects on the kenaf fibers were high in high hydrogen peroxide concentration, high in alkali solution pH, low in long treatment time. The optimal level of hydrogen peroxide on bleaching effects were at $2\%$ hydrogen peroxide concentration, with pH of 11 and treatment time of 60 minutes. Under the conditions of $2\%$ hydrogen peroxide concentration, pH 11 and treatment time of 60 minutes, the addition of chelator: Sodim Pyrophosphate(SP), Citric Acid(CA) made the bleaching effects of the kenaf fibers high.

• Korean Journal of Oriental Medicine
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• v.2 no.1
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• pp.177-191
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• 1996

Chunggansan(淸肝散) was tested for the effects on detoxication mechanism of alcohol. Chunggansan was treated firstly into samples, and then ethanol intoxicated animal models were set with them. In vitro, the level of lipid peroxide in tissue of liver proportionally decreased with the level of concentration of extract prepared from Chunggansan. In vivo, after the extract was administered to the animal model for seven days, the level of lipid peroxide in liver dependently decreased in proportion of concentration. The glutathione percentage purposely induced acute ethanol intoxicated samples, followed by Chunggansan pre-medicating administration, increased in compare with the group treated with only ethanol. Also, the enzyme activities of ALT, AST, and ${gamma}-GTP$ in liver decreased.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1520-1526
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• 2009

We have identified the iscR (PA3815) gene encoding an iron-sulfur cluster assembly regulator homolog as one of the genes required for peroxide resistance in Pseudomonas aeruginosa PA14. Here, we present the phenotypic characterization of an iscR deletion mutant in terms of KatA expression, stress responses, and virulence. The iscR null mutant exhibited reduced KatA activity at the posttranslational level, hypersensitivity to hydrogen peroxide, and virulence-attenuation in Drosophila melanogaster and mouse peritonitis models. These phenotypes were fully restored by multicopy-based expression of katA. These results suggest that the requirement of IscR in P. aeruginosa is related to the proper activity of KatA, which is crucial for peroxide resistance and full virulence of this bacterium.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.5
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• pp.35-41
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• 2012

Liquified hydrogen peroxide as a monopropellant is drawing an attention as a power generating energy source for a machine requiring simple and light weight structure. The liquified hydrogen peroxide is attracted due to its outstanding applicability because it doesn't require an oxidizer and discharge a hazardous product. For the further industrial applications, however, a feasibility study should be carried out carefully in the aspect of the specific power density. In this study, a prototype of vane motor driven by the liquified hydrogen peroxide with high density of upper 95% was developed and its performance characteristic such as a specific power density was estimated via measuring pressure and rotation speed of the vane motor. The specific power density obtained by numerical simulation using FSI analysis supported by experimental results was up to $0.02kW/kg_{f}$, which reaches at the level of the latest developed fuel cell.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.5
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• pp.86-94
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• 1999

Alkaline peroxide bleaching of chemi-mechanical pulp is a very complicated system where various process factors affect the bleacing performance and pulp properties. Traditional onefactor-at a time method is ineffective and costly infinding the optimal bleaching conditions. In this study, statistical experimental design and multiple regression method wre used to investigated the interactions among various bleaching factors and to find out the possbile maximal brightness development during one stage alkaline peroxide bleacing of TMP. The TMP was made from 10% Korean red pine and 90% Korean spruce and had an initial brightness of 54.5% ISO. the TMP was pretreated with EDTA(0.5% on O.D. pulp, 3% pulp consistency, 30$^{\circ}C$ for 60 minutes) and bleached in a 2 L Mark V Quantum Reactor at 750 rmp, 7.5% of bleaching consistency and with 0.05% magnesium sulfate addition. The ranges of chemical factors studied , based on oven-ried pulp, were 1-5% for hydrogen peroxide, 1-4% for sodium hydroxide and 1-4% for sodium silicate. The rages of reaction temperature and time were 50-90$^{\circ}C$ and 40-180minutes respectively. Interactions of hydrogen peroxide with alkali , time with temperature ature, alkali with time and silicate with temperature were found to be significant which means that hydrogen peroxide bleaching will be favored at stable concentration of perhydroxyl ion, relatively short time and low temperature, and high level of silicate. Mathematical model which has good predictability for target brightness in one stage peroxide bleaching can also be established easily. Base ion the model, maximal brightness of 70% ISO was found to at 50$^{\circ}C$ and 50 minutes by chemical additions of 5% for hydrogen peroxide, 3.2-3.4% for sodium hydroxide and 4% for silicate based on O.D. pulp. However, this result might not be suitable for situation where furnishes are different from ours, or different pretreatment is used, or bleaching carried out at different pulp consistency. In these cases it will be good to re-investigate the process by a similar methodology as was used in this study.

• The Journal of Internal Korean Medicine
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• v.21 no.3
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• pp.389-398
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• 2000

The fallowing are the results of the experimental studies of Cordyceps militaris (CM) on the penile nitric oxide synthase (NOS) activity and the level of blood testosterone in hydrocortisone acetate-treated rats. CM was tested for the effects on activity of xanthine oxidase and lipid peroxidation in penis of hydrocortisone acetate-treated rats. In vitro, CM didn't effect the levels of lipid peroxide and the activity of NOS. In the penis of hydrocortisone acetate-treated rats, lipid peroxide, the activities and ratio of type conversion of xanthine oxidase were increased but activity of NOS and content of nitrite were decreased. In vivo, after administration of CM to hydrocortisone acetate-treated rats, levels of lipid peroxide in penis was decreased. Also, the activities and ratio of type conversion of xanthine oxidase were decreased, too. The body weight and concentration of testosterone in the blood were increased. The effects of Cordyceps militalis Broth did better than the effects of Cordyceps militalls Mycelia, These results suggest that CM decrease the activities of free radical generating enzymes such as xanthine oxidase which form lipid peroxide and increase the penile NOS activity and the level of blood testosterone in hydrocortisone acetate-treated rats. Conclusively, CM is capable of improving of sexual ability in hydrocortisone acetate-treated rats.