• Nuclear Engineering and Technology
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• v.51 no.8
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• pp.1957-1963
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• 2019

A UVC photo-Fenton advanced oxidation process (AOP) was studied to develop a process for the decomposition of oxalic acid waste generated in the chemical decontamination of nuclear power plants. The oxalate decomposition behavior was investigated by using a UVC photo-Fenton reactor system with a recirculation tank. The effects of the three operational variables-UVC irradiation, H₂O₂ and Fenton reagent-on the oxalate decomposition behavior were experimentally studied, and the behavior of the decomposition product, CO₂, was observed. UVC irradiation of oxalate resulted in vigorous CO₂ bubbling, and the irradiation dose was thought to be a rate-determining variable. Based on the above results, the oxalate decomposition kinetics were investigated from the viewpoint of radical formation, propagation, and termination reactions. The proposed UVC irradiation density model, expressed by the first-order reaction of oxalate with the same amount of H₂O₂ consumption, satisfactorily predicted the oxalate decomposition behavior, irrespective of the circulate rate in the reactor system within the experimental range.

• Korean Journal of Plant Taxonomy
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• v.41 no.2
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• pp.130-137
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• 2011

Pedicularis growing at Mt. Halla of Jeju Island is known as an endemic species of P. hallaisanensis Hurusawa. On the other hand, the plant is morphologically similar to P. amoena, P. spicata, and P. verticillata in gross morphology, so the taxonomic treatment of the taxon remains controversial. To clarify the taxonomic position of the plants, we examined external morphological characters and nuclear ribosomal DNA ITS sequences for P. hallaisanensis and its related species. The plants of Mt. Halla are clearly different from P. amoena and P. verticillata in the morphology of calyx lobes, the length of galea and lower lip, density of glandular hairs on plants, presences of the radical leaves after anthesis and molecular data. However, P. hallaisanensis is not clearly separated from P. spicata distributed in N. E. Asia on external morphological characters and DNA sequences of internal transcribed spacers. In this study, the morphological and molecular data suggested that P. hallaisanensis should be merged into the former species.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.5
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• pp.47-53
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• 2013

In this study, In order to develop the measurement method of high energy density metal aluminum dust cloud combustion, flame temperature and emission spectrum was measured using spectrometer. Because of the ultra high ${\mu}m$-sized aluminum flame temperature more than 2400 K, it was measured by non-contact optical technique which is the modified two wavelength pyrometry with 520, 640 nm and spectrum comparison method. These methods were applied to experiment after accurate verification. As a result, we could identify that flame temperature is more than 2400 K in bottom of combustor in both methods. And on the emission spectrum analysis, we could measure AlO radical which is occurred dominantly in aluminum combustion.

• YAKHAK HOEJI
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• v.51 no.2
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• pp.88-95
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• 2007

Atractylodes macrocephala has been used for renal anorexia, gastroenteritis, cold, dyspepsia in Korean folk medicine. Specially aerial parts has been eaten as edible mountain herbs. In order to investigate the efficacy of antioxidant activity the activity guided fractionation and isolation of physiologically active substance were peformed. For the investigation of the active components from Atractylodes macrocephala MeOH extracts of aerial parts of Atractylodes macrocephala Koidzumi L. were suspended with H$_2$O, partitioned by CHCl$_3$. In order to investigate the efficacy of antioxidative activity the activity guided fractionation and isolation of physiologically active substance were peformed. CHCl$_3$, H$_2$O, 30% MeOH, 60% MeOH, MeOH fractions were examined antioxidative activity by DPPH method. It was revealed that 30% MeOH and 60% MeOH fractions have significantly antioxidant activity. From 30% MeOH and 60% MeOH fraction, six flavonoids (7-methoxy-pinocembrin-7-O-${\beta}$-D-glucopyranoside, apige nin-8-C-${\beta}$-D-glucopyranoside, 4'-caffeoyl-luteolin-6-glucopyranoside, luteloin-6-C-${\beta}$-D-glucopyranoside, apigenin-6-C-${\beta}$-D-glucopyranoside, luteolin) and four phenylpropanoids (3-feruloylquinic acid, 4,5-di-O-caffeoylquinic acid, feruloyl acid, 3,5-di-O-caffeoylquinic acid) were isolated. To investigate the antioxidant activities of each compounds, we measured radical scavening activity with DPPH method and anti-lipid peroxidative efficacy on low density lipoprotein (LDL) with TBARS assay. Six compounds (III, IV, V, VI, IX, X) which have antioxidant factor showed significant activities.

• Macromolecular Research
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• v.16 no.6
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• pp.549-554
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• 2008

Proton conducting crosslinked membranes were prepared using polymer blends of polystyrene-b-poly(hydroxyethyl acrylate)-b-poly(styrene sulfonic acid) (PS-b-PHEA-b-PSSA) and poly(vinyl alcohol) (PVA). PS-b-PHEA-b-PSSA triblock copolymer at 28:21:51 wt% was synthesized sequentially using atom transfer radical polymerization (ATRP). FT-IR spectroscopy showed that after thermal ($120^{\circ}C$, 2 h) and chemical (sulfosuccinic acid, SA) treatments of the membranes, the middle PHEA block of the triblock copolymer was crosslinked with PVA through an esterification reaction between the -OH group of the membrane and the -COOH group of SA. The ion exchange capacity (IEC) decreased from 1.56 to 0.61 meq/g with increasing amount of PVA. Therefore, the proton conductivity at room temperature decreased from 0.044 to 0.018 S/cm. However, the introduction of PVA resulted in a decrease in water uptake from 87.0 to 44.3%, providing good mechanical properties applicable to the membrane electrode assembly (MEA) of fuel cells. Transmission electron microscopy (TEM) showed that the membrane was microphase-separated with a nanometer range with good connectivity of the $SO_3H$ ionic aggregates. The power density of a single $H_2/O_2$ fuel cell system using the membrane with 50 wt% PVA was $230\;mW/cm^2$ at $70^{\circ}C$ with a relative humidity of 100%. Thermogravimetric analysis (TGA) also showed a decrease in the thermal stability of the membranes with increasing PVA concentration.

• YAKHAK HOEJI
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• v.50 no.6
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• pp.351-357
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• 2006

Polygoni Radix (Polygonaceae) has been used as renal disoder hematopoietic, menstrual irregularity and antiaging in Korean folk medicine. Specially aerial parts has been used for insomnia and sedative agent. In order to investigate the efficacy of antioxidant activity on these aerial parts, the bio-activity guided fraction and isolation of physiologically active substance were performed. H$_2$O, 30%, 60%, 100% MeOH were examined antioxidant activity by DPPH method. It was revealed that 30%, 60% MeOH fractions have significantly antioxidant activity. From 60% MeOH fraction, six known flavonoid glycosides (quercetin, quercetin 3-O-${\beta}$-D-galactopyranosyl-4'-O-glucopyrano side-3'-methyl ether, quercetin 3-O-${\alpha}$-L-rhannopyranoside, quercetin 3-O- ${\alpha}$-L-rhamnopyranoside-4'-methylethor, quorcetin 3-O-${\beta}$-D-galactopyranoside, quercetin 3-O-${\beta}$-D-galactopyranoside) and 3,4-Oihydrocinnarnic acid were isolated. To investigate the antioxidant activities of each com-pounds, we measured radical scavening activity with DPPH method and anti-lipid peroxidative efficacy on low density lipo-protein (LDL) with TBARS assay and anti-acetylcholinestrase activity with Ellman's Test. Four compounds (ll, IV Vl, Vll) of quercetin glycosides showed significant activity.

• Nutrition Research and Practice
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• v.12 no.6
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• pp.503-511
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• 2018

BACKGROUND/OBJECTIVES: Ginger, a root vegetable, is known to have antioxidant and antiobesity effects. Preparation, such as by steaming, can affect the chemical composition of prepared root vegetables or herbs and can change their functional activities. In the present study, we investigated the protective effects of steamed ginger against oxidative stress and steatosis in C57BL/6J mice fed a high-fat diet. MATERIAL/METHODS: The levels of polyphenols and flavonoids in two different extracts of steamed ginger, i.e., water extract (SGW) and ethanolic extract (SGE); as well, their antioxidant activities were examined. Forty male C57BL/6J mice were fed a normal diet (ND, n = 10), high-fat diet (HFD, 60% fat, w/w, n = 10), HFD supplemented with 200 mg/kg of SGE or garcinia (GAR) by weight (SGED or GARD, respectively, n = 10) for 12 weeks. Serum chemistry was examined, and the expressions of genes involved in lipid metabolism were determined in the liver. Histological analysis was performed to identify lipid accumulations in epididymal fat pads and liver. RESULTS: The SGE had higher contents of polyphenols and flavonoids and higher DPPH and $ABTS^+$ free radical scavenging activities compared to those of SGW. Treatment with SGE or GAR significantly decreased the HFD-induced weight gain. Both SGE and GAR significantly reduced the high serum total cholesterol (TC), triglyceride (TG) and low-density lipoprotein levels induced by HFD. Compared to ND, HFD significantly increased hepatic TC and TG levels. SGE or GAR supplementation significantly decreased the increase of hepatic lipids by HFD. Interestingly, SGE had a more significant effect in reducing hepatic TC and TG levels than GAR. Furthermore, hepatic genes involved in lipogenesis and lipolysis were altered in both the SGED and GARD groups. CONCLUSIONS: The present study indicates that steamed ginger supplementation can decrease plasma TC and TG and can inhibit liver steatosis by regulating the expressions of hepatic genes.

• Membrane Journal
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• v.29 no.3
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• pp.164-172
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• 2019

In this work, we demonstrate a facile process to prepare an electrolyte membrane for the supercapacitor based on a graft copolymer consisting of starch and poly(acrylonitrile) (PAN). The graft copolymer (starch-g-PAN) was synthesized via free radical polymerization initiated by ceric ions. The starch-g-PAN was dissolved in ionic liquid, i.e. 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA) without any organic solvents at room temperature. The gelation of polymer electrolyte membranes occurred by applying high temperature, i.e. $100^{\circ}C$ for 1 hour. The resultant electrolyte membrane was flexible and thus applied to flexible solid supercapacitors. The performance of the supercapacitor based on starch-g-PAN graft copolymer electrolyte reached 21 F/g at a current density of 0.5 A/g. The cell also showed high cyclic stability with 86% of retention rate within 10,000 cycles. The preparation of starch-g-PAN based polymer electrolyte membrane provides opportunities for facile fabrication of flexible solid supercapacitors with good performance.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.672-680
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• 2020

This study was conducted to effectively supplement vitamin D and increase the consumption of ear mushroom based on the investigation of the quality characteristics of cookies containing ear mushroom supplemented with vitamin D. Cookies were made of 0%, 1%, 3%, and 5% ear mushroom powder treated by ultraviolet B. Increased addition of ear mushroom powder led to a decrease in the bulk density of the dough as well as a spread factor, color value, and hardness of the cookies. There was no significant difference in the loss rate, but the water content of the dough and cookies was increased. The total polyphenol content of cookies added with 1~5% ear mushroom powder was higher than that of the 0%. The DPPH free radical scavenging activity of cookies added with 5% ear mushroom powder (23.8%) was 2 times higher than that of the 0% (10.9%). The vitamin D2 content of cookies added with 5% ear mushroom powder (835.5 ㎍/100 g D.W.) was 44 times higher than that of the 0% (19.0 ㎍/100 g D.W.). Consequently, ear mushroom powder is considered to be suitable for the production of functional cookies because of high values of antioxidant activity and vitamin D2 content.

• Human Ecology Research
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• v.62 no.1
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• pp.59-68
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• 2024

This study investigated the quality characteristics of butter sponge cakes added with whey protein concentrate (WPC)(0%, 10%, 30%, 50%, 100%) added as a fat substitute. The density of the dough of butter sponge cakes significantly increased with higher levels of added WPC and the pH decreased (F=248.38, p<.001). The moisture content also decreased significantly (F=3.151, p < .05). However, the volume (F=9.556, p<.01) and specific volume (F=11.15, p<.001) significantly increased. With respect to color, there was no significant difference in the lightness (L) value of the crumb, but the redness (a) value increased significantly with higher levels of added WPC (F=12.616, p < .001), while the yellowness (b) value decreased significantly (F=4.550, p<.01). Regarding the crust, the L values (F=3.791, p<.01) and b values (F=7.000, p<.001) decreased significantly with higher levels of added WPC, while the (a) values increased significantly (F=4.706, p<.01). The DPPH radical scavenging ability of the raw WPC used in the manufacture of butter sponge cakes was found to be 27.45%, but this increased significantly as the amount of WPC added to butter sponge cakes increased (F=45.237, p<.001). In a consumer preference test, the flavor, appearance, texture, odor, and overall acceptability were highest in the case of WPC-10 when taking advantage of the functional advantages of WPC as a lowfat substitute, confirming the development potential and optimal amount of WPC that should be added to butter sponge cakes.