• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.5
• /
• pp.1087-1091
• /
• 1999

Microwave extraction system equipped with closed vessels, which is known to rapidly extract target compounds from natural products, was applied to monitor the changes in phenolic compounds, browning color intensity and electron donating ability by using response surface methodology(RSM). Maximum content of phenolic compound was 21.65mg/100ml in 67.88% of ethanol concentration, 145oC of extraction temperature, and 6.24min of extraction time. The phenolic compounds in extracts are dependent on the increase of the extraction temperature and the ethanol concentration. Browning color intensity, which was maximized in 67.21%, 147oC, and 6.02min, was proportional to the increase of the extraction temperature. Maximum value of electron donating ability was 24.50units in 54.33%, 147oC, and 6.11 min. The electron donating ability of extracts was dependent on the increase of extraction temperature and maximized in the range from 50 to 65% of ethanol concentration.

• KSBB Journal
• /
• v.28 no.4
• /
• pp.238-243
• /
• 2013

Astaxanthin is one of the carotenoid with strong antioxidant. The conditions of extraction of astaxanthin from Portunus trituberculatus were optimized in this work. Six factors of conditions such as, extraction method, extraction solvent, ratio of solvent to raw material, temperature, and time, were investigated. For the increase of the extraction yield, ionic liquids were used as additives in the extraction solvent. The optimum extraction conditions were found: heat reflux extraction, Dichloromethane/methanol (25:75, v/v) as solvent, 1:30 of the ratio of solvent raw material, $80^{\circ}C$, 90 min, and ionic liquid as additive. As a result, 45.81 ${\mu}g/g$ of astaxanthin was extracted from waste.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.1
• /
• pp.123-144
• /
• 2014

Wireless sensor networks are generally deployed for specific applications to accomplish certain objectives over a period of time. To fulfill these objectives, it is crucial that the sensor network continues to function for a long time, even if some of its nodes become faulty. Energy efficiency and fault tolerance are undoubtedly the most crucial requirements for the design of an information extraction protocol for any sensor network application. However, most existing software agent based information extraction protocols are incapable of satisfying these requirements because of static agent itineraries and large agent sizes. This paper proposes an Information Extraction protocol based on Multiple software Agents with Dynamic Itineraries (IEMADI), where multiple software agents are dispatched in parallel to perform tasks based on the query assigned to them. IEMADI decides the itinerary for an agent dynamically at each hop using local information. Through mathematical analysis and simulation, we compare the performance of IEMADI with a well known static itinerary based protocol with respect to energy consumption and response time. The results show that IEMADI provides better performance than the static itinerary based protocols.

• Current Research on Agriculture and Life Sciences
• /
• v.29
• /
• pp.83-89
• /
• 2011

Various functional and useful components in Portulaca oleracea were extracted with ethanol and the optimum solvent conditions were set by monitoring of response surface methodology(RSM). A central composite design for optimization was applied to investigate the effects of the three independent variables of extraction temperature, ethanol concentration, and extraction time, on dependent variables including total phenolics, electron-donating ability, brown clolor and total flavonoids of Portulaca oleracea. The content of total phenol was essentially unaffected by extraction time or extraction temperature, but it was highly influenced by ethanol concentration. The maximum total phenol content was 31.70mg/mL obtained at 45.84% of ethanol concentration, $79.66^{\circ}C$, and after 2.67hr of extraction. Electron-donating ability (EDA) was affected by ethanol concentration and the maximum EDA was 74.67mg/mL at 52.95% ethanol concentration, $52.33^{\circ}C$ and 4.84hr of extration time. The browning color was rarely affected by extraction time but, it was highly influenced by ethanol concentration and extraction temperature. The maximum extent of browning color was obtained at 97.75% of ethanol concentraion, $65.88^{\circ}C$ and 2.93hr of extraction time. The content of total flavonoid was significantly influenced by extraction time, and the maximum total flavonoid level was 58.28mg/mL obtained at 96.62% ethanol concentration, $61.87^{\circ}C$ after 3.70hr of extraction. As a result, The optimal conditions for effective extraction were predicted as follows, 70.3% of ethanol concentration, $62.1^{\circ}C$ of extraction temperature and 3.3hr of extraction time.

• Natural Product Sciences
• /
• v.25 no.2
• /
• pp.150-156
• /
• 2019

Conventional extraction of oil and azadirachtin, a botanical insecticide, from Azadirachta indica involves defatting the seeds and leaves using hexane followed by azadirachtin extraction with a polar solvent. In order to simplify the process while maintaining the yield we explored a binary extraction approach using Soxhlet extraction device and hexane and ethanol as non-polar and polar solvents at various ratios and extraction times. The highest oil and azadirachtin yields were obtained at 6 h extraction time using a 50:50 solvent mixture for both neem leaves (44.7 wt%, $720mg_{Aza}/kg_{leaves}$) and seeds (53.5 wt%, $1045mg_{Aza}/kg_{leaves}$), respectively.

• Journal of Korean Society of Water and Wastewater
• /
• v.18 no.5
• /
• pp.638-648
• /
• 2004

In many drinking water treatment plants, chlorination process is one of the main techniques used for the disinfection of water. This disinfecting treatment leads to the formation of haloacetic acid (HAAs). In this study, headspace solid-phase microextraction (HS-SPME) was studied as a possible alternative to liquid-liquid extraction for the analysis of HAAs in drinking water. The method involves direct derivatization of the acids to their methyl esters without methyl tert-butyl ether (MTBE) extraction, followed by HS-SPME with a $2cm-50/30{\mu}m$ divinylbenzene/carboxen/polydimethylsiloxane fiber. The effects of experimental parameters such as selection of SPME fiber, the volume of sulphuric acid and methanol, derivatization temperature and time, the addition of salts, extraction temperature and time, and desorption time on the analysis were investigated. Analytical parameters such as linearity, repeatability and limit of detection were also evaluated. The $2cm-50/30{\mu}m$-divinylbenzene/carboxen/polydimethylsiloxane fiber, sulphuric acid of 1ml, methanol of 3ml, derivatization temperature of $50^{\circ}C$ derivatization time of 2hrs, sodium chloride salt of 10g, extraction time of 30 minutes, extraction temperature of $20^{\circ}C$ and desorption time of 1 minute at $260^{\circ}C$ were selected as the optimal experimental conditions for the analysis of HAAs. The linearities ($r^2$), relative standard deviations (%RSD) and limits of detection (LOD) for HAAs were 0.9978~0.9991, 1.1~9.8% and $0.05{\sim}0.2{\mu}g/l$, respectively.

• Korean journal of food and cookery science
• /
• v.18 no.1
• /
• pp.51-56
• /
• 2002

This study was carried out to develop a traditional functional beverage by using hot-water extraction of dried peels of Korean tangerine. The pH of the hot-water extracts of dried tangerine peels decreased as the extraction time increased. The acidity and viscosity of the extracts increased as the extraction time increased. The antioxidative activity of the extracts during the extraction was monitored by measuring the electron donating ability. The electron donating abilities of the extracts were in the range of 80.93-83.27%. Extraction time did not affect the antioxidative activity of the extracts. The fibrinolytic activity of the extracts increased as the extraction time increased. The pH of the beverage made with the peel extract was not affected by the extraction time and the kind of sweetener added. The viscosity of the beverage increased as the extraction time increased. In sensory evaluation the highest score was obtained in the beverage samples made with the ones extracted for 180 min and added with sugar. The aboveresults indicate that the dried peel of Korean tangerine can be used as a functional material in beverage industry.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.2
• /
• pp.244-251
• /
• 2009

Extraction characteristics of dried jujube and functional properties of corresponding extract were monitored by response surface methodology. Maximum extraction yield of 53.69% was obtained at extraction temperature of $50.35^{\circ}C$, extraction time of 16.69 hr, and ethanol concentration of 72.88%. At extraction temperature, extraction time, and ethanol concentration of $45.80^{\circ}C$, 15.47 hr, and 73.12%, respectively, maximum cyclic adenosine monophosphate content was 8.20 mg/100 g. Maximum total polyphenol content was 18.85 mg/g at extraction temperature, extraction time, and ethanol concentration of $64.91^{\circ}C$, 20.84 hr, and 66.91%, respectively. Maximum total flavonoid content was 0.48 mg/g at extraction temperature, extraction time, and ethanol concentration of $57.36^{\circ}C$, 15.14 hr, and 71.08%, respectively. $IC_{50}$ value of electron donating ability showed maximum level of 32.34 mg/mL at extraction temperature of $48.46^{\circ}C$, extraction time of 19.25 hr, and ethanol concentration of 65.36%. Maximum ascorbic acid equivalent antioxidant capacity was 3.58 mg ascorbic acid equivalent per gram sample at extraction temperature, extraction time, and ethanol concentration of $56.09^{\circ}C$, 21.86 hr, and 65.36%, respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.2
• /
• pp.11-23
• /
• 2011

In this paper, an accurate and fully automatic video object segmentation method is proposed for video conferencing systems in which the real-time performance is required. The proposed method consists of two steps: 1) accurate object extraction on the initial frame, 2) real-time object extraction from the next frame using the result of the first step. Object extraction on the initial frame starts with generating a cumulative edge map obtained from frame differences in the beginning. This is because we can estimate the initial shape of the foreground object from the cumulative motion. This estimated shape is used to assign the seeds for both object and background, which are needed for Graph-Cut segmentation. Once the foreground object is extracted by Graph-Cut segmentation, real-time object extraction is conducted using the extracted object and the double edge map obtained from the difference between two successive frames. Experimental results show that the proposed method is suitable for real-time processing even in VGA resolution videos contrary to previous methods, being a useful tool for immersive video conferencing systems.

• Korean Journal of Pharmacognosy
• /
• v.38 no.1
• /
• pp.56-61
• /
• 2007

This study was carried out to investigate the optimum conditions for extraction of acidic polysaccharides from red ginseng marc produced by manufacturing alcoholic extract from red ginseng. Method of carbazole-sulfuric acid was applied to determine the amount of acidic polysaccharides in red ginseng marc. The amounts of acidic polysaccharides in water extract of red ginseng marc were increased with increasing extraction temperature. The contents of acidic polysaccharides were not significantly different despite of the extraction time increasing from 6 hours to 48 hours. The contents of starch in water-extract of red ginseng marc were increased with increasing extraction temperature. The starch amounts in water extract of red ginseng marc extracted for 48 hours were increased. The yields of polysaccharide precipitated from water-extract of red ginseng marc were increased with increasing extraction temperature. The hydration rate of acidic polysaccharides and starch from water-extract of red ginseng marc were decreased with increasing extraction temperature. The contents of starch were not significantly different despite of the extraction time increasing from 6 hours to 48 hours at $8^{\circ}C$. However, the rehydration rate of acidic polysaccharide for 48 hours were decreased at $8^{\circ}C$. The rehydration rate of acidic polysaccharide and starch extracted from 6 hours to 24 hours at $25^{\circ}C$ were not significantly different, but those extracted for 48 hours were increased. From the above results, we suggest that by altering the extraction conditions in red ginseng marc it is possible to develop optimum conditions for extraction that modulate the proportions of acidic polysaccharide and starch.