• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2009년도 춘계학술대회 논문집
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• pp.53-56
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• 2009

In this paper, performance evaluation of catalyst for hydrogen peroxide thruster with drying condition is described. Platinum was selected as a catalyst, and alumina of pellet type was chosen as a catalyst support. Evaporation method known as general method for catalyst production was used to make the catalyst. From previous experiments, it is favorable during catalyst making process that solution of active material has low pH level. Therefore, some kinds of low pH level solution had been tested. The drying temperatures are 25, 50, 70, and $90^{\circ}C$. From experimental results, it shows better performance that drying temperature was $90^{\circ}C$ since the catalyst particle could not be crystallized but be evenly spreaded out due to the rapid evaporation of solvent.

• Journal of Korean Society on Water Environment
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• 제28권5호
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• pp.704-716
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• 2012

This paper provides a detailed account of pilot testing conducted at South Lake Tahoe (California), the Ddukdo (Seoul) water treatment plant (WTP) and the Bokjung (Seongnam) WTP between February, 2010, and February, 2012. The objectives were first, to characterize the reactions of ozone with hydrogen peroxide (Peroxone) for Han River water following sand filtration, second to determine empirical ozone and hydrogen peroxide doses to remove a taste-and-odor surrogate 2-methylisoborneol (MIB) using an advanced oxidation process (AOP) configuration and third, to determine the optimum dosing configuration to reduce residual ozone to a safe level at the exit of the process. The testing was performed in a real-time plant environment at both low- and high seasonal water temperatures. Experimental results including ozone decomposition rates were dependent on temperature and pH, consistent with data reported by other researchers. MIB in post-sand-filtration water was spiked to 40-50 ng/L, and in all cases, it was reduced to below the specified target level (7 ng/liter) and typically non-detect (ND). It was demonstrated that Peroxone could achieve both MIB removal and low effluent ozone residual at ozone+hydrogen peroxide doses less than those for ozone alone. An empirical predictive model, suitable for use by design engineers and operating personnel and for incorporation in plant control systems was developed. Due to a significant reduction in the ozone reaction/decomposition at low winter temperatures, results demonstrate the hydrogen peroxide can be "pre-conditioned" in order to increase initial reaction rates and achieve lower ozone residuals. Results also indicate the method, location and composition of hydrogen peroxide injection is critical to successful implementation of Peroxone without using excessive chemicals or degrading performance.

• The Journal of Korean Medicine
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• 제19권2호
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• pp.112-124
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• 1998

The purpose of this study was to investigate the effect of Brousson etiae fructus (BF) on the urethral nitrite level and the urethral nitric oxide synthase (NOS) activity in streptozotocin (STZ) induced diabetic rats. In vitro, the urethral NOS activity was not noted in the level of Dose of extract prepared from BF. In vivo, the urethral NOS activity was increased in normal rats and STZ induced diabetic rats by dose and term of extract prerared from BF. The the NOS activity decreased in STZ induced diabetic rats was increased as highly as norma1 group by the extract of BF The level of urethral nitrite and glutathione was increased too. But the level of urethral lipid peroxide increased in STZ induced diabetic rats was decreased as lowly as normal group by the extract of BF. In conclusion, the extract of BF can restore erectile dysfunction of STZ induced diabetic rats.

• Food Science and Preservation
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• 제10권3호
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• pp.401-405
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• 2003

The antibiotic and antioxidant effect of botanical antimicrobial agent-citrus product(BAAC) prepared from citrus fruits were investigated by using fishmeats made from pollack and ascidian fillet. We inoculated Salmonella typhi into fishmeats that were aferwards treated with BAAC varying the concentration level (50-500ppm) including the control not-treated with BAAC. While specimens were stored at 5$^{\circ}C$ for designated period, we measured changes of total number of bacteria, peroxide level and textural properties. In addition, we performed organoleptic examination, focusing on appearance, texture and odor for fishmeats treated with BAAC and stored for designated period. For pollack and ascidian fishmeats, the initial total number of bacteria were 3.7${\times}$l0$^4$CFU/g and 7.5${\times}$l0$^4$CFU/g, respectively. After they were treated with 250 ppm of BAAC solution and stored for 5 days at 5$^{\circ}C$, the figures reduced to 2.5${\times}$l0CFU/g and 8.4${\times}$10CFU/g. No bacteria were found in fishmeats treated with above 500 ppm of BAAC, which remarkably proved antibiotic effect of BAAC solution. Furthermore, all the BAAC-treated specimens exhibited notable antioxidant effect. Fishmeats which were previously treated with 500 ppm of BAAC solution and stored for 30 days at 5$^{\circ}C$, showed the lower peroxide level of 16.5 meq/kg than 68.9 meq/kg in the control of pollack and 21.2 meq/kg than 80.7 meq/kg in the control of ascidian. In the results of texture and organoleptic evaluation we could also observe good effects of BAAC on maintaining the freshness of fisher products.

• Asian-Australasian Journal of Animal Sciences
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• 제13권10호
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• pp.1373-1376
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• 2000

The peroxidation status of tissues was estimated in broilers under acute or chronic heat stress ($32^{\circ}C$, 24 h, $5{\times}24h$) in the present study. The results showed that the lipid peroxide (LPO) concentrations in plasma and liver were elevated (p<0.05) by acute heat stress, and were not influenced in kidney (p>0.05). At the same time, no significant change of superoxide dismutase (SOD) activity in the liver, kidney or plasma was observed. Under chronic heat exposure, the SOD activity in liver was increased (p<0.05) and the LPO concentrations in the liver and plasma were restored to the normal levels. The LPO level in kidney was not affected by chronic heat stress (p>0.05), but SOD activity was significantly decreased (p<0.01). The results suggested that the peroxidation was induced by acute heat stress and disappeared along with the time of heat exposure, and the peroxidation reactions were different among tissues.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 한국추진공학회 2008년 영문 학술대회
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• pp.378-382
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• 2008

A 50 N monopropellant thruster being developed for attitude control in a variety of aerospace application systems is described in this paper. Ninety percent hydrogen peroxide was selected as a propellant, since it is much less hazardous than hydrazine. A scaled down thruster with aluminum oxide loaded with the platinum in the reaction chamber was tested to determine propellant decomposition onto a catalyst. A scaled up 50 N thruster, with a catalyst bed of 3 cm in diameter and 4 cm in length, was evaluated by decomposition efficiency based on temperature, ${\eta}_T$, efficiency of characteristic velocity, ${\eta}_{C^*}$, and measurement of thrust. The performance of a 50 N thruster was 40.5 Newton in thrust, about 100 % in ${\eta}_T$, and 98 % in ${\eta}_{C^*}$, and 125 sec in specific impulse at sea level.

• Journal of the Korean Society of Food Science and Nutrition
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• 제20권4호
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• pp.285-292
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• 1991

The effects of acute and chronic ethanol administration on hepatic and cerebellar glutathione (GSH) statuses and lipid peroxide levels in rats were investigated. In the liver, chronic ethanol feeding (6.9 g/kg, per day) as 10% (v/v) drinking water for 4 weeks produced a slight decrease of total GSH and an increase in the ratio of GSSG/total GSH without change of GSSG (oxidized GSH). Lipid peroxide level however was not modified. Many other studies have shown the acute ethanol loading effect in the rat liver, that is moderate decrease of total GSH and elevation of lipid peroxide level. Relating to this, it was observed that total GSH in the plasma obtained from post. hepatic inferior vena cava was increased by acute ethanol injection (50 mmol/kg, i.p.). This increased hepatic efflux of GSH into blood, in addition to the promoted antioxidative utilization of GSH, could be suggested as one of the possible reasons for the decrease of hepatic GSH induced by ethanol load. In the cerebellum, acute ethanol load did not change the total GSH and GSSG, but increased the lipid peroxidation rate. In the chronic, neither GSH pattern nor lipid peroxidation rate was changed.

• Journal of Nutrition and Health
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• 제31권4호
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• pp.687-696
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• 1998

This study was performed to investigate effects of hesperidin and naringin on linpid peroxide formation and antioxidative enzyme activities in rats. Thiobarbituric acid reactive substance (TBARS) concentrations were measured in plasma and liver. Catalase, superoxide dismutase, and glutathione peroxidase activities were measured in erythrocyte and liver. Forty-nine male Sprague-Dauley rats weighing 275.3$\pm$3.3g were blocked into seven groups according to body weight and were raised fro four weeks on diets containing 0.25, 0.50 or 1.00%(w/w) hesperidin or naringin . Food intake, weight gain , food efficiency ratio, and weights of liver, kidney, spleen ,and epididymal fat pad were not significantly different among groups. In 0.50 and 1.00% naringin groups , plasma TBARS concentrations were significantly decreased with a dose response patter. In 0.25, 0.50 and 1.00% hesperidin groups, liver TBARS concentrations were significantly decreased without a dose dependent patter. Antiosidative enzyme activities in erythrocyte and liver were not significantly affected by type and amountof dietary bioflavonoid, but in the 1.00% hesperidin group, catalase, superoxide dismutase, and glutahione perosidase activities in linver showed a tendency to increase. In conclusion, naringin inhibited lipid peroxide formation with a dose response pattern in plasma without changing the activities of antioxidative enzymes. Hesperidin adminstration, regardless of the level in the diet, inhibited lipid peroxide formation in liver.

• Journal of the Korean Society of Food Culture
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• 제20권3호
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• pp.352-359
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• 2005

The red ginseng powder was added to Yackwa dough as ratio to 0%, 2%, 4%, 6% and 8%, respectively to know effect of red ginseng powder on Yackwa quality and preservation. The expansion, color, texture and preference characters were investigated at 0,2 and 4 weeks, respectively. The peroxide and acid value were also measured. The 4% addition increased greatly expansion rate. In color test, L value lowed at addition of red ginseng powder and at long storage period. the b value lowed as the addition was increased, but a value was not affected by the addition of red ginseng powder. In mechanical texture test, addition of red ginseng powder had a tendency to show low cohessivness, springness, gumminess while hardness increased. The springness, brittleness and cohessivness decreased while hardness increased at long storage period. In sensory test, surface color, bitterness and red ginseng flavor were recognized strong by addition of red ginseng powder but oily taste, crispness, softness and overall preference were weak. The surface color and red ginseng flavor were strong at long storage period but sweetness, softness and overall preference decreased, respectively. The peroxide value increased at long storage period and decreased after 6 week. The 2% and 4% addition showed lower peroxide value compared to other treatment. The acid value increased at early storage period, but did not change after 4 weeks.

• Journal of the Korean Society of Food Science and Nutrition
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• 제33권1호
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• pp.72-77
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• 2004

Diabetic vascular complications such as atherosclerosis have been reported as one of significant obstructions in treatment of diabetes. There has been a significant increase in recognition of the importance of antioxidative nutrients such as vitamin E, for the prevention of diabetic vascular complication by oxidative stress. This study focused on the effect of dietary $\beta$-carotene on the levels of lipid peroxide and antioxidative vitamins of diabetic rats. The plasma glucose level, hepatic level of lipid peroxide and contents of antioxidants such as vitamins A and E were determined in STZ-induced diabetic rats. Dietary supplementation of B-carotene did not reduce the blood glucose in diabetic rats. Hepatic level of lipid peroxide tended to increase in diabetic rats, but $\beta$-carotene intake reduced the value. Plasma levels of retinol and retinol/lipid were not changed by dietary supplementation of $\beta$-carotene. There was no significant difference among experimental groups in plasma level of $\alpha$-tocopherol. Hepatic levels of retionl and retinyl palmitate were increased by dietary supplementation of $\beta$-carotene in diabetic rats. These results suggest that the supplementation of $\beta$-carotene to the normal diet of diabetics may reduce the incidence of the diabetic vascular complications through the improvement of antioxidants depletion.