• Resources Recycling
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• v.15 no.4 s.72
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• pp.36-43
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• 2006

There was some difficulty dewatering properties due to small porosity diameter of cake, when pigment sludge contained fine particle was formed by cake under the dewatering. It was difficult to dewater the sludge with fine particles with the conventional mechanical dewatering method. This study was to improve the dewatering rate as discharging the water from porosity of cake easily, supplying the low heat to the cake layer. Thermal dewatering equipment of piston type to keep up constant temperature on the cake was set up and relative experiment was conducted for sludge of 200 g with fine pigment particle. As test results. filtration of 176.8 g, cake weight of 19.4 g, cake thickness of 4.2 mm was measured, and it was analyzed that the water content of cake was 47 wt% and dewatering velocity, which moaned the residual d교 sloid amount per dewatering area, was $2.1DS\;m^{2}{\cdot}cycle$. This results showed that filtration increased, cake weight and thickness decreased and dewatering velocity increased against mechanical dewatering method. And water content of cake decreased about 30%, so the result which dewatering rate improved was drew generally. The reason is that the inner vapor pressure working at the cake porosity increased as applying the low heat to the cake layer, which lead to discharge the water from porosity easily. Therefore, this study was estimated by the useful technology for sludge reduction.

• Resources Recycling
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• v.21 no.3
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• pp.21-27
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• 2012

In order to make high-purity ferro-manganese from $Mn_3O_4$ dust, the application of aluminothermy process to the reduction of $Mn_3O_4$ dust was investigated in previous work. The result showed the fact that can be obtained high purity ferro-manganese which have over about 93% of manganese content and lower impurities such as C, P, S than those of KS D3712 specification. The addition of silicon powder instead of aluminum powder was investigated as reductant in the thermite reaction process of $Mn_3O_4$ dust in this work because its production cost is lower than that of aluminum powder. In case of addition of silicon powder only as reductant, the experimental result showed the unstable ignition and no thermite reaction of mixture, but in case of simultaneous addition of silicon and aluminum powders as reductant, showed the fact that can be obtained high purity ferro-manganese which have much low content of impurities such as C, P, S component.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.201-208
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• 2007

Functional oils (FOs) were produced from commercial diacylglycerol oil and red yeast rice extracts from 80% ethanol for 1 hr in a shaking water bath at $35^{\circ}C$ and 175 rpm. FOs contained (A) 600, (B) 1200, (C) 1800, and (D) 2280 ppm of red yeast-rice extracts, respectively. The Hunter a value and b value were risen whereas L value was reduced along with the increase of extract concentration. Content of monacolin K and total phenolic compounds in FOs significantly increased according to the increase of extract concentration. The oxidation stability of FOs was observed by Rancimat at $98^{\circ}C$. Induction time decreased according to the increase of extract concentration. The major volatile compounds of FOs were compared using the electronic nose (EN) system and solid phase microextraction (SPME) method combined with gas chromatograph/mass spectrometry (GC/MS). EN was composed of 12 different metal oxide sensors. Sensitivities (Rgas/Rair) of sensors from EN were analyzed by principal component analysis (PCA), whose proportion was 99.66%. For qualitative or quantitative analysis of volatile compounds by SPME-GC/MS, the divinylbenzene/carboxene/polydimethyl-siloxane fiber and sampling temperature of $50^{\circ}C$ were applied.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.553-560
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• 2021

Theanine, the major amino acid and a sweet umami component of green tea, has anti-stress effects in humans. From green tea, theanine was extracted at 80℃ for 2 h using a low temperature, high pressure extractor, and caffeine was removed using an HP-20 column with 80% ethanol. Theanine extracts were applied to produce functional jelly using three kinds of gelling agents (I, II, and III) or various concentrations of theanine extracts (10-50%). Theanine jelly was characterized with respect to its physical properties, product stability, and physiological function. Gelling agent III (tamarind gum, xanthan gum, and locust bean gum=2:3:5, w/w/w) and S3 (35% theanine extracts) jelly exhibited the optimum textural properties with lower hardness and high springiness. Among theanine jellies, S3 exhibited optimum product stability, high 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging, and acetylcholinesterase inhibitory activity. These results indicate that the anine extracts could be used as a neuroprotective source in the food industry.

• Food Science and Preservation
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• v.16 no.1
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• pp.101-108
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• 2009

The purpose of this study was to measure flavonoid and polyphenol contents, and physiological activities of various extracts from Vitex rotundifolia seeds (known as Man Hyung Ja). We obtained three extracts using water (WE), ethanol (EE) and hot water (HWE). The EE sample had the highest flavonoid content of 31.05 mg/g. Polyphenol contents of WE and HWE were 186.69 mg/g and 182.55 mg/g, respectively. HWE had the highest superoxide dismutase (SOD)-like activity, at 83.40%. The electron donating abilities (EDA) were $91.14{\sim}95.97%$ at the concentration of 1.0 mg/mL, and all of extracts showed more than 88% EDA even at a concentration of 0.1 mg/mL. The inhibitory rates of xanthine oxidase were $94.02{\sim}97.51%$ when 1.0 mg/mL extracts were used, and all extracts showed more than 90% inhibition at 0.5 mg/mL. The nitrite scavenging abilities were $59.27{\sim}86.61%$ at pH 1.2 and 1.0 mg/mL extract concentration; these abilities decreased as pH increased. Tyrosinase inhibition activities of HWE and WE were 48.58% and 46.67%, respectively. These results indicate that Vitex rotundifolia seeds extract might be an effective antioxidative activity.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.340-345
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• 2010

국내의 건축물은 강한 내력을 갖기 위해 사용되는 HSC빈도가 점진적 증가하고 있으며, HSC로 시공되어진 건축구조물에서의 화재 발생시 폭렬현상의 문제점이 대두되고 있다. 이에 국내외에서 폭렬현상에 대한 연구들이 진행되었고, 이를 통해 폭렬현상에 원인을 알게 되어 이를 토대로 폭렬 방지 방안을 세웠다. 이에 따라 폭렬현상의 원인 중 합수율이 있으며, 이는 콘크리트가 함유하고 있는 수분으로 고온시에 팽창하여 폭렬현상의 매커니즘이 형성된다. 또한 이러한 함수율이 폭렬 발생에 미치는 영향을 크게 하는 요인으로 탄산화와 양생방법이 있다. 우선 탄산화는 반응을 일으킬 경우, 생성물이 공극을 채워 고온시 팽창된 수분이 외부로 나가는 것을 방해하여 수증기압을 축적시키고, 양생방법에 따라 함수율이 달라지게 되어 고온시 팽창될 수분의 양을 결정하게 된다. 특히, 함수율에 의해 발생되는 폭렬을 방지하기 위해 고강도 콘크리트 내부의 수분을 제거하는 강제건조를 하거나 팽창된 수분이 빠져나갈 곳을 만들기 위해 고온에서 녹는 PP섬유를 사용해 공극을 만들어주는 방법이 있다. 따라서 본 연구는 HSC의 폭렬현상방지 대책을 위한 기초자료를 제시하고자 한다.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.06a
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• pp.53-66
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• 2001

본 실험실에서는 혈당강하효과를 갖는 chiroinositol을 다량 함유하고 있는 식품이나 식용물질을 탐색하여 선발하고, 선택된 식품이나 식용물질에서 chiroinositol을 lab-scale로 분리 정제하여 제조된 chiroinositol의 추출물로 동물실험을 실시하여 혈당강하효과를 증명하고 그 기작을 연구하고 있다. 약 300여종의 식품 및 식용물질을 GC-MS 및 HPLC로 분석한 결과 식품으로 안전한 탈지대두와 두부 순물에서 chiroinositol의 함량이 각각 6.45mg/g, 20mg/g으로 조사되어 선택되었고, chiroinositol의 순도가 40-60%(w/w)인 chiroinositol의 추출물을 이용하여 동물실험을 통한 혈당강하효과를 조사한 결과, 1) steptozotocin(STZ)으로 유발된 고혈당쥐에 경구투여시, 농도 의존적으로 혈당을 감소시키는 탁월한 기능을 나타내었고, 2) 정상쥐의 혈당제거율 검사(glucose tolerance test)에서강한 제거율 및 6시간의 지속시간을 나타내었으며, 3) STZ로 유발된 고혈당쥐의 혈당제거율 검사에서 강한 혈당강하 효과(약 40%)를 나타내었으며 지속시간은 약 12시간이었다. 4) 극심한 고혈당(450 내지 500mg/d)의 경우, 경미한 고혈당(300내지 350mg/d)의 경우보다 혈당 감소율이 20% 가량 높았으며, 지속시간도 1시간 이상 긴 것으로 나타났으며, 5) 인슐린과 복합처리 했을 때 상승작용(synergy)을 나타내었으며, 저혈당증으로 전혀 발전되지 않았다.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.11
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• pp.803-808
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• 2013

The purpose of this study was performed to investigate the optimum conditions of pH, concrete sludge, seed dosage, mixing intensity, operation time in treating fluoride-containing wastewater as $CaF_2$ using the ready-mixed concrete sludge. Considering fluoride removal, water content, that pH 6, concrete sludge dosage of 10 g/L, Seed dosage ($CaF_2$) of 2 g/L, mixing intensity of 100 rpm and operation time of 60 min were found to be optimum. Correspondingly, removal of fluoride and water content was about 85% and 64%, respectively. Increase in amount of seed dosage did not affect fluoride removal efficiency. but the result that the water content is decreased was shown up in occuring the solid-liquid separation well.

• Clean Technology
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• v.27 no.4
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• pp.306-314
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• 2021

Grape skins are a natural resource rich in antioxidants, but people only eat grape flesh and have discarded the skins. This study investigated the possibility of using grape skin extract as a raw material for functional cosmetics. The dried grape skin powder was put in distilled water and stirred for 1 h, and then the supernatant separated from the solid was used as an extract. The extract yield was 17.8 ~ 31.4%, and the total flavonoid and polyphenol contents in the extract were 1.8 ~ 2.5 mg-QE g-extract^-1 and 16.9 ~ 20.3 mg-GAE g-extract^-1, respectively. The extract effectively removed radicals of DPPH and ABTS, and the degree of scavenging increased with the concentration of the extract. The extract inhibited the collagen hydrolysis activity of collagenase, and the activity inhibition rate increased to 84.2% as the extract concentration increased. However, notable inhibition of tyrosinase by the extract was not found. As the extract of Chamaecyparis obtusa was added to the grape-skin extract, the tyrosinase inhibition rate increased, but the DPPH radical scavenging activity decreased. This study found that grape skin extract has a high antioxidant capacity and anti-wrinkle effect but a low whitening effect. However, by mixing the grape skin extract with the extract of C. obtusa in an optimal ratio, the whitening effect was improved with excellent antioxidant and anti-wrinkle effects.

• Resources Recycling
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• v.26 no.3
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• pp.53-60
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• 2017

Black dross contains metallic aluminium, alumina, silica, MgO, soluble salts together with minor ingredients. Control of silica in black dross is important in transforming the black dross into usable materials. First, most of the soluble salts (KCl and NaCl) in black dross were dissolved in water at reaction temperature of $50^{\circ}C$. Leaching behavior of silica, alumina, MgO and $TiO_2$ from the residue after water treatment was investigated by varying NaOH concentration and reaction temperature. Reaction temperature ($25{\sim}95^{\circ}C$) was favorable to the leaching of alumina but an optimum temperature existed for silica. MgO was not dissolved at all in the NaOH concentration range from 2 to 6 M. At the leaching condition of 5 M NaOH and reaction temperature of $95^{\circ}C$, approximately 80% of alumina and 68% of silica was dissolved.