• 설비공학논문집
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• 제13권7호
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• pp.549-556
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• 2001

Heat flow characteristics during hot water extraction process was studied experimentally. Data were taken at various outlet port type for the fixed inlet port type, inlet-outlet temperature differences and mass flow rates. In this study, the temperature distribution in a storage tank and an outlet temperature were measured to predict a flow pattern in the storage tank, and a hot water extraction efficiency was analysed with respect to the variables dominating a extraction process. Experimental results show that the extraction efficiency is high in a low flow rate in case of using modified distributor I(MDI) as a outlet port type.

• 태양에너지
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• 제18권3호
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• pp.71-80
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• 1998

In thermal energy storage system, energy collected from many types of heat source is stored in a storage tank and then supply to load for demand. Lately, practical use of thermal energy storage system and attention to essential use of energy have been increased. From this point of view, especially, a study about the energy extraction process from a storage tank is necessary. So in this study, useful rate of hot water and hot water extraction efficiency was analysed respect to dynamic and geometric parameters dominating the hot water extraction process.

• 한국식품조리과학회지
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• 제28권1호
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• pp.51-55
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• 2012

This study was conducted to investigate the physicochemical properties of citrus peel extracts with different hot water extraction and enzymatic hydrolysis conditions. Enzymatic hydrolysis was also employed using Viscozyme L and results were compared with that of optimized hot water extract. Hot water extraction was performed under different parameters; the sample to solvent ratio(1:20, 1:15, 1:10), extraction time(2, 4 hrs), extraction temperature(85, $95^{\circ}C$) and enzymatic hydrolysis(0, 1%) and the subsequent extracts were used for determining their physicochemical properties, such as total yield, total phenolics, total flavonoids, and electron donating ability (EDA). With the increase in the sample to solvent ratio and extraction time, total yield, total phenolics, total flavonoids and EDA increased. But extraction temperature did not significantly affect the hot water extract. As hot water extract was hydrolyzed by the enzyme, total yield and active ingredients increased rapidly. In the result of total yield, total phenolics, total flavonoids and EDA, the activity of enzyme-treated extract was higher than those of enzyme-untreated extract. Based upon the overall hot water extraction efficiency, it was found that 20 times volume or 120 min at a time at $95^{\circ}C$ after enzyme treatment was optimal.

• Korean Chemical Engineering Research
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• 제54권3호
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• pp.310-314
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• 2016

합성 항산화제에 대한 대체제로 천연 항산화제에 대한 연구가 활발히 진행되고 있으며 미세조류는 천연 항산화제의 원료로 많은 관심을 받고 있다. 본 연구에서는 탈지미세조류에서 총 폴리페놀(TPC) 추출증대를 위해 추출용매, 온도, 시간, 고액비율과 에탄올 첨가 농도 최적화를 수행하였다. 열수와 유기용매 추출성능을 비교했을 때, 열수추출이 유기용매 보다 우수한 성능을 보였으며 온도 증가에 따라 추출성능도 비례하여 증가함을 보였다. 열수에 의한 추출이 에탄올 용액 추출(>98%)에 비해 우수한 성능을 보였으며40% 에탄올 용액을 이용한 열수 추출이 가장 우수한 추출 효과를 보였다. 추출조건10 min, $100^{\circ}C$, 40% 에탄올 열수추출에서 최대 폴리페놀 농도인 3.35 mg GAE (gallic acid equivalent)/g DM을 얻을 수 있었다. 지질 추출을 위한 유기용매 전처리 공정이 선수행 되었음에도 불구하고 탈지미세조류(Tetraselmis KCTC 12236BP)의 폴리페놀 농도가 다른 탈지이전 미세조류와 동등한 수준임을 확인할 수 있어 탈지미세조류가 천연 폴리페놀의 원료로서 적합함을 확인 할 수 있었다. 또한, 고액추출을 모사하기 위해 Peleg 모델을 이용해 예측한 폴리페놀 농도가 실험에 의해 얻어진 값과 높은 일치도를 보임으로 모델을 이용한 모사가 폴리페놀 추출 모사에 유용함을 증명할 수 있었다.

• 생약학회지
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• 제45권1호
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• pp.55-61
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• 2014

Microwaves are non-ionizing electromagnetic waves of frequency between 300MHz to 300GHz and positioned between the X-ray and infrared rays in the electromagnetic spectrum. In recent years, the use of microwave for extraction of ingredient from plant material has shown remarkable research interest and potential. Scutellaria radix has been used as a traditional medicine for a variety of diseases. It has been reported to exert beneficial health effects, such as anti-bacterial, antiviral, anti-inflammatory, and free-radical scavenging. Oxidative stress or the accumulation of reactive oxygen species (ROS) leads neuronal cellular death and dysfunction, and it contributes to neuronal degenerative disease such as Alzheimer's disease, Parkinson's disease and stroke. In this study, we aimed to compare the neuroprotective and antioxidant effect of Scutellaria radix extracted by different methods using hot-water extraction (SBE-DW) or microwave extraction (SBE-DW-MW). As a result, we first examined HPLC analysis of hot-water and microwave extracts of Scutellaria radix. The hot-water and microwave extracts of Scutellaria radix showed the discernible difference patterns of HPLC analysis. Microwave-water extracts of Scutellaria radix increased DPPH radical scavenging activity more than hot-water extraction. Microwave-water extracts of Scutellaria radix also showed neuroprotective effects and ROS inhibition against glutamate-induced oxidative stress in mouse hippocampal HT22 cells, but hot-water extraction not showed. In addition, the phosphorylation of MAPKs induced by glutamate insult was prevented by microwave-water extracts of Scutellaria radix. Thus, these results suggested that microwave extraction can be utilized for improving the extraction efficiency and biological activity of Scutellaria radix.

• 태양에너지
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• 제11권2호
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• pp.34-40
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• 1991

Thermal stratification enhancement for the higher extraction efficiency of hot water storage tank was experimentally studied with transparent fiber glass cylindical tank($350{\ell}$, D=516mm, H=1680mm). Height to diameter ratio (H/D =1,2,3), flow rate(Q= 8,10,12LPM), inlet-outlet temperature differences(${\Delta}T=20,25,30^{\circ}C$), and geometry of inlet-outlet port were the parameters. In particular, three kind of distributors were used for geometry of inlet-outlet port. As a result, it was possible to get extraction efficiency of 95% by using the distributor having variable diameter but keeping a constant diameter of perforation. So it is recommendable to design the distributor so that the main pipe decrease in diameter toward the dead end.

• 한국지열·수열에너지학회논문집
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• 제14권4호
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• pp.7-12
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• 2018

Energy performance of electric heater and geothermal source heat pump type hot air dryers are compared in this study. For set temperatures of $30^{\circ}C$, $35^{\circ}C$ and $40^{\circ}C$, radish is dried from initial mass 60 kg until it gets 5 kg, where the difference equals the amount of water removed. As set temperature is increased, drying time is shortened for both electric heater and heat pump types, however energy efficiency is decreased due to increasing electricity consumption. Moisture extraction rate(MER) of electric heater is 2.58~2.84 kg/h, and for heat pump type 2.56~2.71 kg/h, showing little difference between the two types. Specific moisture extraction rate (SMER) of electric heater is 0.94~0.96 kg/kWh, and for heat pump type 1.72~2.21 kg/kWh. SMER of heat pump type is greater by 0.78~1.25 kg/kWh than the electric heater hot air dryer, which is 1.8~2.3 times better in terms of energy efficiency.

• 한국식품저장유통학회지
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• 제12권2호
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• pp.146-150
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• 2005

오가피(Acanthopanax senticosus)로부터 영양 및 기능성 성분의 열수추출 수율을 증대시킬 수 있는 방법을 개발하기 위하여 추출 전처리 및 방법의 효과를 검토하였다. 오가피를 분쇄, 체질$(8\~20\;mesh)$하고 초음파(20 kHz), 마이크로파 (2,450 MHz) 또는 볶음$(180^{\circ}C)$ 처리를 10분 동안 실시한 후 물을 용매로 상압$(100^{\circ}C)$ 추출과 가압$(121^{\circ}C)$ 추출을 각각 2시간 동안 실시하였다. 전반적으로 전처리는 성분들의 추출수율과 유리기 소거능을 증가 시키는 경향을 보였다. 특히, 가용성 고형물, 총당 및 페놀성 물질의 추출수율은 마이크로파와 초음파에 의해, 단백질의 추출수율과 유리기 소거능은 볶음처리에 의해 더욱 증가됨을 보였다. 상압추출보다 가압추출에 의해 가용성 고형물, 총당, 단백질 및 페놀성 물질의 추출수율이 증대되는 경향을 보였다. 이로써 초음파, 마이크로파 및 볶음 전처리 및 가압추출은 오가피의 추출효율 향상에 유효한 방법인 것으로 판단된다.

• 한국식품저장유통학회지
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• 제9권2호
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• pp.184-188
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• 2002

동충하초를 음료로 개발하기 위한 전단계로 열수추출공정을 반응표면분석법으로 최적화하였다. 추출시간에 따라서는 큰 변화가 없어 추출온도와 농도를 요인변수로 하여 실험을 수행하였다. 열수추출액의 당도(brix)와 고형분 함량은 농도에 따라서 큰 영향을 받는 것으로 나타났다. 추출액의 탁도와 총당, 환원당 및 단백질 함량은 낮은 농도에서 추출수율이 좋은 것으로 나타났다. 각 반응변수 모두 농도에 대하여는 유의성이 있는 것으로 나타났으며 수립된 이차 회귀식에 대한 적합성 결여분석 결과 수립된 반응표면 모형이 통계적으로 유의하였다. 동충하초 열수추출에 있어 고형분함량은 2.0~2.4%, brix 1.5~l.8, 총당 l14~120 $\mu\textrm{g}$/g, 환원당 10.5~11.0 $\mu\textrm{g}$/g 그리고 단백질함량 110~l15 $\mu\textrm{g}$/g인 영역을 만족하는 조건은 추출온도 95~10$0^{\circ}C$, 농도 4.0~4.1%로 결정할 수 있었다.

• 한국식품영양학회지
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• 제24권3호
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• pp.458-463
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• 2011

The effect of subcritical water for the extraction of total polyphenols and flavonoids from apple peel was investigated, and then the antioxidant activity of the extracts was estimated. Maximum yields of total polyphenolic compounds($36.4{\pm}1.9mg$ quercetin equivalent(QE)/g dried material) and flavonoids($9.9{\pm}0.8mg$ QE/g dried material) were obtained by subcritical water extraction(SWE) with operating conditions of $190^{\circ}C$, 1,300 psi, and 20 min. Furthermore, the highest antioxidant activity($76.1{\pm}1.1%$) was observed in the extract obtained from SWE using the same conditions. The flavonoids from the SWE of apple peel were compared to three conventional extraction methods in terms of their extraction efficiency and antioxidant activity. The SWE was significantly more effective than hot water ($90^{\circ}C$), methanol, and ethanol extraction for flavonoid yield by 4.7-, 2.2-, and 1.3-fold, respectively, and for antioxidant activity by 11.0-, 4.9, and 2.8-fold, respectively.