• Korean journal of food and cookery science
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• v.28 no.1
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• pp.25-32
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• 2012

This study was carried out to evaluate biological activities concerning extracts according to extraction methods from unripened fruit of Rubus coreanus Miq. The extraction methods were HWE (hot water extraction for 4 hr at $100^{\circ}C$), SFE (extraction for 3 hr at $40^{\circ}C$ under 300 bar, 100% of $CO_2$ fluid), USE (ultrasonification extraction for 4 hr at $50^{\circ}C$ with water), USE+HWE (hot water extraction for 2 hr at $100^{\circ}C$ after ultrasonification process for 2 hr), VE (vacuum extraction for 4 hr at $90^{\circ}C$ under 0.9 bar with water). VE extract showed the highest contents of total polyphenol ($178.78{\pm}3.79\;mg/g$) and total flavonoid ($40.93{\pm}0.68\;mg/g$). $IC_{50}$ values of DPPH radical scavenging activity, linoleic acid peroxidation inhibition activity and LDL (low density lipoprotein) oxidation inhibition activity of HWE extract showed the lowest $35.39{\pm}0.25{\mu}g/mL$, $12.61{\pm}0.31{\mu}g/mL$ and $1.31{\pm}0.02{\mu}g/mL$ among other all extracts, respectively. $IC_{50}$ values of ${\alpha}$-glucosidase inhibitory activities of VE and HWE extracts showed lower $14.34{\pm}0.20{\mu}g/mL$ and $15.83{\pm}0.20{\mu}g/mL$ than those of other extracts, respectively. Specifically, HWE and VE extracts have relatively better biological activities than other extracts; these could be potentially used as a bioactive source for health functional foods.

• Food Science and Preservation
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• v.14 no.1
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• pp.67-72
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• 2007

To prepare useful foods from Acanthopanax koreanum, extraction of major constituents by water and ethanol solutions were investigated Reflux extractions of 300 g of dried material of particle size less than 0.5 cm, were carried out in 7.5 L of water, or ethanol solutions (30 -95% v/v) for 9 hr at $100^{\circ}C$. The pH values of extracted solutions were 4.0-6.5. The Color b-value of extracted solutions increased as ethanol concentrations dropped and with longer extraction times. The amounts of material in extracts increased rapidly in the first 2-3 hr of extraction. The extract levels from 30-70% ethanol solutions were 0.27-0.47 g/100 g. The main free sugars of extract were sucrose, fructose and glucose. Eleutherosides were extracted rapidly (within 3 hr), and eleutheroside extraction was best in water or in 30-70% ethanol 95% ethanol solutions were less effective. The eleutherosides were extracted to 97% by water or 30-70% ethanol solutions after 3-5 hr. Acanthoic acid extraction was more affected by ethanol level than by extraction time water achieved only trace extinction. In summary, reflux extraction in 40-70% ethanol for 3-5 hr was adequate for the extraction of functional materials from Acanthopanax koreanum.

• Korean Journal of Remote Sensing
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• v.31 no.4
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• pp.293-302
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• 2015

Water body extraction is significant for flood disaster monitoring using satellite imagery. Conventional methods have focused on finding an index, which highlights water body and suppresses non-water body such as vegetation or soil area. The Normalized Difference Water Index (NDWI) is typically used to extract water body from satellite images. The drawback of NDWI, however, is that some man-made objects in built-up areas have NDWI values similar to water body. The objective of this paper is to propose a new method that could extract correctly water body with built-up areas in before and after images of flood. We first create a two-element feature vector consisting of NDWI and a Near InfRared band (NIR) and then select a training site on water body area. After computing the mean vector and the covariance matrix of the training site, we classify each pixel into water body based on Mahalanobis distance. We also register before and after images of flood using outlier removal and triangulation-based local transformation. We finally create a change map by combining the before-flooding water body and after-flooding water body. The experimental results show that the overall accuracy and Kappa coefficient of the proposed method were 97.25% and 94.14%, respectively, while those of the NDWI method were 89.5% and 69.6%, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.6
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• pp.503-511
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• 2002

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 degree of stratification in the storage tank, and a useful rate of hot water was analysed with respect to the variables dominating a extraction process. Experimental results show that the degree of stratification and useful rate of hot water are all high in a low flow rate in case of using modified distributor I (MDI) as the outlet port type.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.111-116
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• 2016

To determine the optimum condition for the extraction of active components, noni adventitious roots were extracted under various conditions employing various solvents including methanolic water at different ratio (20, 40, 60, 80, and 100% water), extraction times and extraction methods. Anthraquinones, phenolic compounds, and flavonoids extraction using different solvents showed that 1 h of ultrasonic extraction was effective in 60-80% methanol, and 2 h of reflux extraction was effective in 80% methanol. To compare the extraction efficiency of active components according to different extraction methods and extraction times for noni adventitious roots, the active components were extracted by ultrasonic extraction, shaking extraction, reflux extraction, homogenizer extraction, high-pressure extraction, and soaking extraction. The highest phenolic contents were found in the extracted from ultrasonic extraction and anthraquinones and flavonoids contents were highest in the reflux extraction.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.91-95
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• 1998

Some physical properties and chemical compositions of Lycii Cortex depending on the various extracting conditions were investigated for their changes during extraction with ethanol and water. Solid matter and contents of total sugar in water extracts were higher than those of ethanol extract. but contents of tannic acid in ethanol extracts was higher than that in water extracts. The methanol extract of the Lycii Cortex were fractionated with ethyl ether. ethyl acetate. n-butanol and water. The yield was higher in the order of water > n - butanol > ethyl ether and ethyl acetate fraction. Turbidity of water extraction was higher than that of ethanol extraction.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.241-246
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• 2004

The ocean signal that reaches the detector of an imaging system after multiple interactions with the atmospheric molecules and aerosols was retrieved from the total signal recorded at the top of the atmosphere (TOA). A simple method referred to as 'Path Extraction' applied to the Landsat-TM ocean imagery of turbid coastal water was compared with the conventional dark-pixel subtraction technique. The shape of the path-extracted water-leaving radiance spectrum resembled the radiance spectrum measured in-situ. The path-extraction was also extended to the SeaWiFS ocean color imagery and compared with the standard SeaWiFS atmospheric correction algorithm, which relays on the assumption of zero water leaving radiance at the two NIR wavebands (765 and 865nm). The path-extracted water-leaving radiance was good agreement with the measured radiance spectrum. In contrast, the standard SeaWiFS atmospheric correction algorithm led to essential underestimation of the water-leaving radiance in the blue-green part of the spectrum. The reason is that the assumption of zero water-leaving radiance at 755 and 865nm fails due to backscattering by suspended mineral particles. Therefore, the near infrared channels 765 and 865nm used fur deriving the aerosol information are no longer valid for turbid coastal waters. The path-extraction is identified as a simple and efficient method of extracting the path radiance largely introduced due to light interaction through the complex atmosphere carried several aerosol and gaseous components and at the air-sea interface.interface.

• Journal of Information Processing Systems
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• v.17 no.5
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• pp.947-959
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• 2021

Aiming at the problem of low accuracy in the water boundary automatic extraction of islands from GF-2 remote sensing image with high resolution in three bands, new water edges automatic extraction method in island based on GF-2 remote sensing images, genetic algorithm (GA) method, is proposed in this paper. Firstly, the GA-OTSU threshold segmentation algorithm based on the combination of GA and the maximal inter-class variance method (OTSU) was used to segment the island in GF-2 remote sensing image after pre-processing. Then, the morphological closed operation was used to fill in the holes in the segmented binary image, and the boundary was extracted by the Sobel edge detection operator to obtain the water edge. The experimental results showed that the proposed method was better than the contrast methods in both the segmentation performance and the accuracy of water boundary extraction in island from GF-2 remote sensing images.

• Journal of Environmental Science International
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• v.23 no.6
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• pp.1037-1047
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• 2014

A highly sensitive analytical method based on stir bar sorptive extraction (SBSE) technique and gas chromatography/tandem mass spectrometry (GC/MS-MS) has been developed, allowing the simultaneous multi-analyte determination of seven UV filters in water samples. The stir bar coated with polydimethylsiloxane (PDMS) was added to 40 mL of water sample at pH 3 and stirred at 1,100 rpm for 120 min. Other SBSE parameters (salt effect and presence of organic solvent) were optimised. The method shows good linearity (coefficients > 0.990) and reproducibility (RSD < 12.9%). The extraction efficiencies were above 84% for all the compounds. The limits of detections (LOD) and limits of quantification (LOQ) were 2.1~8.6 ng/L and 6.8~27.5 ng/L, respectively. The developed method offers the ability to detect 8 UV filters at ultra-low concentration levels with only 40 mL of sample volume. Matrix effects in tap water, river water, wastewater treatment plant (WWTP) final effluent water and seawater were investigated and it was shown that the method is suitable for the analysis of trace level of 7 UV filters except of benzophenone (BP). The method developed in the present study has the advantage of being rapid, simple, high-sensitive and both user and environmentally friendly.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.122-127
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• 2006

Fundamental studies were carried out for an effective removal and recovery of silver from waste photo-developing solution by solvent extraction. The organic solvents examined for silver-extraction were ALIQUAT 336, D2EHPA, KELEX 100, and TBP. ALIQUAT 336, which is an anionic exchanger, was found to be efficient for the extraction of silver and the reason for this was considered to be due to the chloride ion contained in its structure. The extent of silver extraction was examined to increase with the concentration of ALIQUAT 336 until it reached 0.6 M and no more extraction was observed above this concentration. The extraction of silver by ALIQUAT 336 was found to reach its pseudo-equilibrium within a few minutes after the reaction started and additional slight increase in silver extraction was observed until 30 minutes of reaction time. The observed differences in silver extraction for artificial and actual waste solutions were considered to be based upon the different ionic form of silver-containing species in these solutions.