• Journal of Soil and Groundwater Environment
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• v.20 no.5
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• pp.47-51
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• 2015

Biocatalytic degradation of total petroleum hydrocarbons (TPHs) in contaminated soil by hemoglobin and hydrogen peroxide is an effective soil remediation method. This study used a laboratory soil reactor experiment to evaluate the effectiveness of a nonspecific biocatalytic reaction with hemoglobin and H₂O₂ for treating TPH-contaminated soil. We also quantified changes in the soil microbial community using real-time PCR analysis during the experimental treatment. The results show that the measured rate constant for the reaction with added hemoglobin was 0.051/day, about 3.5 times higher than the constant for the reaction with only H₂O₂ (0.014/day). After four weeks of treatment, 76% of the initial soil TPH concentration was removed with hemoglobin and hydrogen peroxide treatment. The removal of initial soil TPH concentration was 26% when only hydrogen peroxide was used. The soil microbial community, based on 16S rRNA gene copy number, was higher (7.1 × 10⁶ copy number/g of bacteria, and 7.4 × 10⁵ copy number/g of Archaea, respectively) in the hemoglobin catalyzed treatment. Our results show that TPH treatment in contaminated soil using hemoglobin catalyzed oxidation led to the enhanced removal effectiveness and was non-toxic to the native soil microbial community in the initial soil.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.340-348
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• 2015

Removal efficiency of PCBs in contaminated marine sediments treated by Fenton-like oxidation combined with surfactant was investigated in this research in order to achieve remediation of PCBs. A washing treatment using various concentrations of hydrogen peroxide (1% and 15%) and surfactants (Triton X-100, Tween 60 and Tween 80) was evaluated at various conditions in laboratory scale experiments. The mean removal efficiencies of tPCBs varied from 24.1 to 46.7% in the sediments for 1 hour duration of the treatments. The concentration of tPCBs in contaminated marine sediments after the simultaneous treatment with hydrogen peroxide and surfactant satisfied the domestic environmental standards for the beneficial use of sediments. When suitable surfactant was used for Fenton-like oxidation, the removal efficiency of tPCBs at low concentration of hydrogen peroxide was similar to that at high hydrogen peroxide concentration. Thus the efficient removal of PCBs in contaminated marine sediments could be achieved through treatment with Fenton-like oxidation combined with surfactant washing.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.56-62
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• 2011

An experimental study on design of a catalytic ignitor was performed to use an ignition source for a small bi-propellant liquid rocket engine which use hydrogen peroxide and kerosene as propellants. In the catalytic ignitor, hot gas of hydrogen peroxide which was decomposed by a catalyst induced autoignition of kerosene. Mass flow rate and O/F ratio for the ignitor were calculated by CEA code. A combustion chamber which had a quartz window and thermocouples was manufactured to determine whether the ignition is successful. Ignition performance was investigated according to exit area of fixed rings and mixture ratio. Results showed that reliable ignition performance was achieved at non-choking exit area of fixed ring and O/F ratio of 6~8.

• The Korean Journal of Food And Nutrition
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• v.33 no.3
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• pp.347-355
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• 2020

Cognitive impairment is considered to be key research topics in the field of neurodegenerative diseases and in understanding of learning and memory. In the present study, we investigated neuroprotective effects of Schisandra chinensis (SC) and Ribes fasciculatum (RF) extracts in hydrogen peroxide-induced neuronal cell death in vitro and scopolamine-induced cognitive impairment in Sprague Dawley^® (SD) rat in vivo. Apoptotic cell death in neuroblastic PC12 cell line was induced by hydrogen peroxide for 1 hour at 100 μM. However, mixture of SC and RF treatment prevented peroxide induced PC12 cell death with no neurotoxic effects. For in vivo experiment, the effect of SC and RF extracts on scopolamine-induced cognitive impairment in SD rat was evaluated by spontaneous alternation behavior in Y-Maze test. After 30 min scopolamine injection, the scopolamine-induced rats presented significantly decreased % spontaneous alteration and acetylcholine level, compared to non-induced group. However, treatment of SC+RF extracts rescued the reduced % spontaneous alteration with acetylcholine concentration from hippocampus in scopolamine-induced rats. These results suggested that mixture of SC and RF extract may be a potential natural therapeutic agent for the prevention of cognitive impairment.

• BMB Reports
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• v.38 no.2
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• pp.218-224
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• 2005

Antioxidant enzymes are related to the resistance to various abiotic stresses including salinity. Barley is relatively tolerant to saline stress among crop plants, but little information is available on barley antioxidant enzymes under salinity stress. We investigated temporal and spatial responses of activities and isoform profiles of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), non-specific peroxidase (POX), and glutathione reductase (GR) to saline stress in barley seedlings treated with 200 mM NaCl for 0, 1, 2, 5 days, respectively. In the control plant, hydrogen peroxide content was about 2-fold higher in the root than in the shoot. Under saline stress, hydrogen peroxide content was decreased drastically by 70% at 2 d after NaCl treatment (DAT) in the root. In the leaf, however, the content was remained unchanged by 2 DAT and increased about 14 % at 5 DAT. In general, the activities of antioxidant enzymes were increased in the root and shoot under saline stress. But the increase was more significant and consistent in the root. The activities of SOD, CAT, APX, POX, and GR were increased significantly in the root within 1 DAT, and various elevated levels were maintained by 5 DAT. Among the antioxidant enzymes, CAT activity was increased the most drastically. The significant increase in the activities of SOD, CAT, APX, POX, and GR in the NaCl-stressed barley root was highly correlated with the increased expression of the constitutive isoforms as well as the induced ones. The hydrogen peroxide content in the root was most highly correlated with the CAT activity, indicating an increased role of CAT in hydrogen peroxide detoxification under salinity stress. In addition, the results suggest the significance of temporal and spatial regulation of each antioxidant isoform in determining the competence of the antioxidant capacity under saline stress.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.174-181
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• 2009

Statement of problem: There is a reduction of dentin bonding strength when the bonding procedure is carried out immediately after bleaching with peroxides. Purpose: The aim of this study is to evaluate a proper time interval for in-office bleaching technique using 35% hydrogen peroxide. Material and methods: Fifty extracted non-caries human third molars were used in this study. Buccal enamel of each tooth was removed and polished by 600 grits silicone carbide paper. They were randomly divided into five groups and bleached 35% hydrogen peroxide except control group. All groups were bonded with Single Bond/Z 350 after each time intervals ; Group-A: control, no bleaching treatment. Group-B: resin bonding immediately after bleaching. Group-C: resin bonding 1day after bleaching. Group-D: resin bonding 2 days after bleaching. Group-E: resin bonding 7days after bleaching. Shear bond strengths were measured with a cross-head speed of 1.0 mm/min using an Instron machine. The data of results were statistically analyzed by analysis of variance(ANOVA) and Tukey multiple comparison test.(P=.05) Results: There were significant decreases in mean shear strength in immediately bonding group after bleaching. The reduction of bond strengths was 78% compared with the group of no bleaching treatment. Group C showed the recovery of 51%, and Group D showed recovery of 63%. Both of them have no statistical difference with non-bleaching group. Group E showed no statistical difference with no bleaching treatment group. Conclusion: Dentin bonding strength is significantly reduced when bonding is performed immediately after bleaching for in-office bleaching regimens using 35% hydrogen peroxide, and increases as time goes by. One week of elapsed time between bleaching and resin bonding significantly increases bonding strengths for the in-office bleaching technique.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.172-176
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• 2014

BACKGROUND/OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is becoming an important public health problem as metabolic syndrome and type 2 diabetes have become epidemic. In this study we investigated the protective effect of Cordyceps militaris (C. militaris) against NAFLD in an obese mouse model. MATERIALS/METHODS: Four-week-old male ob/ob mice were fed an AIN-93G diet or a diet containing 1% C. militaris water extract for 10 weeks after 1 week of adaptation. Serum glucose, insulin, free fatty acid (FFA), alanine transaminase (ALT), and proinflammatory cytokines were measured. Hepatic levels of lipids, glutathione (GSH), and lipid peroxide were determined. RESULTS: Consumption of C. militaris significantly decreased serum glucose, as well as homeostasis model assessment for insulin resistance (HOMA-IR), in ob/ob mice. In addition to lowering serum FFA levels, C. militaris also significantly decreased hepatic total lipids and triglyceride contents. Serum ALT activities and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) levels were reduced by C. militaris. Consumption of C. militaris increased hepatic GSH and reduced lipid peroxide levels. CONCLUSIONS: These results indicate that C. militaris can exert protective effects against development of NAFLD, partly by reducing inflammatory cytokines and improving hepatic antioxidant status in ob/ob mice.

• Elastomers and Composites
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• v.53 no.1
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• pp.1-5
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• 2018

In the current research, the curing kinetics of a mixture system consisting of a Bisphenol-A type vinyl ester resin and styrene monomer was studied. Methylethylketone peroxide and cobalt octoate were used as the polymerization initiator and accelerator respectively. Thermograms with several different heating rates were obtained using non-isothermal differential scanning calorimetry. Activation energy values analyzed by the Flynn-Wall-Ozawa isoconversional method showed a three-step change with conversion ${\alpha}$: a slight decrease initially for ${\alpha}$ < 0.1, a constant value of 47.9 kJ/mol in the range 0.1 < ${\alpha}$ < 0.7, and a slow increase for 0.7 < ${\alpha}$. When assuming a constant activation energy of 47.9 kJ/mol, an autocatalytic model of the Sestak-Berggren equation was considered as the proper mathematical model of the conversion function, indicating an overall order of 1.2.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.349-352
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• 2006

The conventional pulping processes in Iran were reviewed in this paper. On account of forest resources restriction, a considerable extent of non-harvestable hardwood forests, the possibility of accessable non-wood resources and Poplar fast-growing species for using in pulp and paper industry was investigate. The cultivated area and abundance of each mentioned raw material (Wheat Straw, Sugarcane Bagasse, Poplars) were specified and the quality of their produced papers were compared in strength and opacity properties. Spruce species data was used for experiments comparisons. Regarding to environmental pollutions, low yield, inflexibility in wood and non-wood species resulted from the existent conventional processes of paper manufacturing, APMP is recommended due to high quality paper, desirable opacity properties, high yield and also the usage for all the raw materials.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.574-579
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• 2004

Quality characteristics of citron-treated mackerel oil and fillet during refrigerated storage were evaluated. Citron-treated and non-treated mackerel oil and fillet were estimated by periodical measurements of acid, peroxide, carbonyl, volatile basic nitrogen, trimethylamine-N, and thiobarbituric acid values. Volatile basic nitrogen and trimethylarnine-N values in mackerel fillet treated with citron for 25 days during refrigerated storage were significantly lower than those of citron non-treated mackerel fillet, with those of boiled citron water-treat group significantly decreasing compared to 1 and 2% citron extract groups. Acid, peroxide, carbonyl, and thiobarbituric acid values of citron-treated mackerel oil were significantly lower than those of citron non-treated mackerel oil throughout storage period. Overall acceptability of salted mackerel fillets treated with boiled citron water and 1% citron extract was significantly than those of control and 2% citron extract. Results indicate application of citron juice on mackerel surface may be useful to lower rancidity degree and fish odor during refrigerated storage.