• Nuclear Engineering and Technology
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• 제51권8호
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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.

• 식물분류학회지
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• 제41권2호
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• pp.130-137
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• 2011

제주도 한라산에 자라는 한라송이풀은 고유종 Pedicularis hallaisanensis Hurusawa로 인식되고 있다. 한편 이 식물은 근연종인 P. amoena, 구름송이풀 또는 이삭송이풀과 형태적으로 유사하여 분류학적 처리가 혼동되어왔다. 본 연구는 이 식물의 분류학적 위치를 파악하기 위하여 한라송이풀과 근연종을 대상으로 외부형태 및 핵 리보소옴 DNA 염기서열을 조사하였다. 한라산의 이 식물은 꽃받침 열편, 화판 상순과 하순의 길이 비, 식물체의 선모 밀도, 개화기 근생엽의 유무 및 염기서열 자료에서 P. amoena 및 구름송이풀과는 뚜렷한 차이를 보였다. 하지만 한라송이풀은 외부형태 및 ITS 염기서열에서 동북아에 분포하는 이삭송이풀과 뚜렷이 구별되지 않았다. 본 연구의 형태 및 분자생물학적 자료는 한라송이풀이 이삭송이풀로 통합되는 것을 지지하였다.

• 한국추진공학회지
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• 제17권5호
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• pp.47-53
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• 2013

본 연구에서는 고에너지 금속 알루미늄 군입자 연소 화염 분석을 위한 측정기법 개발 연구로서 스펙트로메터를 사용하여 화염 온도와 자발광 스펙트럼을 측정하였다. 마이크로 크기의 알루미늄 군입자 연소 반응시 발생하는 화염온도는 약 2400 K 이상의 초고온이므로 비접촉식 광학 계측 방법을 사용하였으며, 측정을 위해 개발된 기법은 520 nm, 640 nm를 사용하는 이색법을 응용한 방법과 광대역 파장 비교법으로서 각각의 방법은 정밀하게 검증 후 실험에 적용되었다. 연소실 하단에서 화염온도 측정결과 두 방법 모두 2400 K 이상의 화염온도를 확인할 수 있었으며 자발광 측정 결과 알루미늄 연소 반응시 가장 지배적으로 발생하는 화학종인 AlO를 확인할 수 있었다.

• 약학회지
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• 제51권2호
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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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• 제16권6호
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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.

• 약학회지
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• 제50권6호
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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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• 제12권6호
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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.

• 멤브레인
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• 제29권3호
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• pp.164-172
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• 2019

본 연구에서는 녹말(starch)과 poly(acrylonitrile) (PAN)으로 이루어진 가지형 공중합체 기반의 슈퍼 캐퍼시터용 전해질막을 손쉽게 제조하는 방법을 제시하였다. 가지형 공중합체(starch-g-PAN)는 세륨 이온에 의해 개시된 자유 라디칼 중합을 통해 합성되었다. 실온에서 어떠한 유기용매 없이 Starch-g-PAN 고분자를 이온성 액체, 1-ethyl-3-methylimidazolium dicyanamide (EMIM DCA)에 용해하였으며 1시간 동안 $100^{\circ}C$의 고온을 가해줌으로써 손쉽게 고분자 막을 만들었다. 제조된 막은 유연하여 플렉서블 고체 슈퍼 캐퍼시터의 전해질에 적용되었다. Starch-g-PAN 기반의 고분자 전해질막을 사용한 슈퍼 캐퍼시터는 0.5 A/g의 전류 밀도에서 약 21 F/g의 정전용량을 가졌으며 10,000 사이클 동안 86%의 유지율을 보이며 높은 주기 안정성을 보였다. 본 연구를 통해 starch-g-PAN 기반의 고분자 전해질막이 우수한 성능을 가진 플렉서블 고체 슈퍼 캐퍼시터에 응용될 수 있음을 확인하였다.

• 한국식품영양학회지
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• 제33권6호
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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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• 제62권1호
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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.