• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.275-281
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• 2012

Yellow croaker Larimichthys polyactis muscle oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-$CO_2$), in a semi-batch flow extraction process. SC-$CO_2$ was applied at temperature $35^{\circ}C$ to $45^{\circ}C$ and $150^{\circ}C$ to $250^{\circ}C$ bar of pressure. The flow rate of $CO_2$ (27.79 g/min) was constant throughout the entire 1.5 h extraction period. The oil extraction yield was influenced by the physical properties of SC-$CO_2$ at different temperatures and pressures. The extracted oil was analyzed by gas chromatography to determine the fatty acid composition. According to our results, the SC-$CO_2$ extracted oil was high in eicosapentaenoic acid and docosahexaenoic acid. In addition, the SC-$CO_2$ extracted oil showed greater stability than n-hexane extracted oil based on the peroxide value and acid value. Thus, the quality of yellow croaker oil obtained by SC-$CO_2$ extraction was slightly higher than that of oil obtained by n-hexane extraction.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2004.05a
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• pp.218-226
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• 2004

Solvent extraction and stripping experiments were conducted to separate iron from a spent $FeCl_3$ etching solution containing nickel. In the extraction, PC88A, MIBK and Alamine336 were tested as an extractant in various diluents. Alamine336 salt in toluene led to the highest extraction percentage of iron. Stripping percentage of iron from the loaded organic by Alamine336 increased with decreasing HCl conentration of stripping solution and with increasing volume ratio of aqueous to organic. In the operation of bench scale mixer-settler, 7 extraction stage with 1.0M Alamine336 salt in toluene and 10 stripping stage with 0.01M HCl solution resulted in a stripped solution with 133g/L of iron and in a raffinate with most of nickel together with a small amount of iron when the flow rate ratio of organic to aqueous was 7.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.120-143
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• 2018

The analytical methods and their ambient levels of organic nitrogenous compounds such as nitrosamines, nitramines (nitroamines), imines, amides and nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in the atmosphere are summarized and discussed. Sampling for the analysis of organic nitrogenous compounds was mostly conducted using high volume air sampler. The direct liquid extraction (DLE) using sonification and the pressurized liquid extraction (PLE) using the accelerated solvent extraction (ASE) have been frequently employed for the extraction of organic nitrogenous compounds in the atmospheric samples. After extraction, clean-up via filtration and the solid phase extraction (SPE) and concentrations using nitrogen and rotary evaporator have been generally conducted but in some studies the clean-up and concentration steps have been omitted to prevent the loss of analyte and improve the recovery rate of the analytical procedure. Instrumental analysis was mainly carried out using gas chromatography (GC) or the high performance liquid chromatography (HPLC) coupled with the single quadrupole mass spectrometer or tandem mass spectrometer in the electron ionization (EI), positive chemical ionization (PCI) and negative chemical ionization (NCI) mode and analysis sensitivity of nitrosamines and nitramines were higher in NCI mode. Desirable sampling and analysis methods for analyzing particulate organic nitrogenous compounds are suggested.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.253-258
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• 1994

This thesis is to analyze the ingredients of five-fruit tea depending on extraction time as a basic experiment for quality improvement and industrialization of traditional Korean beverage. According to extraction time, the acidity of the tea is 2.4% at 30 minutes, 2.3% at 50 minutes and 1.7% at 70 minutes, and soluble solid is 0.22 g, 0.31 g and 0.41 g. The pH of five-fruit tea, which is 4.70, 4.85 and 4.98 at each time, and total sugar is 54.01 m9, 108.82 m9 and 142.92 mg as extraction time increases. The total amount of free sugars is 1.14 mg, 1.36 mg and 2.17 mg, and glucose, surcose and fructose which are 98.2%, 92.6% and 92.6% of the whole percentage occupy the most part of free sugars. The total free amino acids content increases to 84.94 mg, 99.67 mg and 120.40 mg. The five kinds of amino acids like serine, glutamic acid, threonine, proline and alanine amount to 94.5%, 93.6% and 94.7% at all. she variation in the percentage of free amino acids content in accordance with extraction time is as follows : threonine, extracted for 50 minutes, is reduced considerably and glutamic acid decreases gradually as extraction time increases. When proline is extracted for 50 minutes, it's rate of increase Is most high.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.2
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• pp.114-119
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• 2003

This study is to remove several organic pollutants from wastewater by non-dispersive membrane solvent extraction technique. The distribution coefficients of several solvents were determined and the experimental system was operated counter-currently and cocurrently with respect to the aqueous phase and solvent. In these experiments, as the flow rate of aqueous solution inclosed, due to being shortened contact time to solvent, the rate of removal of organic pollutants decreased and as the flow rate of solvent increased, the rate of removal increased. Meanwhile, the rate of removal of organic pollutants for the countercurrent flow system was higher than that for the occurrent flow system.

• Journal of Information Processing Systems
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• v.2 no.1
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• pp.13-17
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• 2006

In this paper, we propose an audio extraction method to decrease the influence of the original signal by modifying the watermarking detection system proposed by P. Bassia et al. In the extraction of the watermark, we employ a simple mean filter to remove the influence of the original signal as a preprocessing of extraction and the repetitive insertion of the watermark. As the result of the experiment, for which we used about 20 kinds of actual audio data, we obtain a watermark detection rate of about 95% and a good performance even after the various signal processing attacks.

• Journal of the Korean Dietetic Association
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• v.4 no.1
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• pp.14-19
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• 1998

This study was designed to investigate the role of onion as a natural antioxidant. Onion was distinguished as yellow onion peel and onion flesh. Onion samples were extracted with 5 different kinds of solvents such as water, 70% ethanol, 99.9%ethanol, 99.9% methanol, and 96% butanol in order to select optimal extraction solvents, In this part of study linoleic acid was used s an model system for the purpose of determining the antioxidant activities. The optimal extraction rate of various solvents containing onion samples was determined by measuring extraction yield, electron donating ability(EDA), thiobarbituric acid(TBA), and thiocyanate, which are common methods for measuring activity. As a result 70% ethanol was shown as the most effective solvent.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.133-139
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• 1997

The solvent extraction method was applied on the wastewater produced during malonate(malonic acid esters) process to recover cobalt. DEHPA and PC88A were used as organic solvent From separation funnel experiment(batch experiment), the effects of vari- ous parameters (pH, cobalt concentration, reaction rate, and stripping temperature) on solvent extraction were examined and these data were used to derive equilibrium curve. A mixer-settler experiment (continuous experiment) of bench scale was also carried out for the plant construction and a Mccabe-Thiele diagram was obtained. The results of these experiments indicate that cobalt is recoverable above 99 oyo and that its purity as cobalt sulfate Is higher than 99.9 wt%.

• Phonetics and Speech Sciences
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• v.5 no.1
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• pp.11-16
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• 2013

This paper proposes robust feature extraction for accurate voice activity detection (VAD). VAD is one of the principal modules for speech signal processing such as speech codec, speech enhancement, and speech recognition. Noisy environments contain nonstationary noises causing the accuracy of the VAD to drastically decline because the fluctuation of features in the noise intervals results in increased false alarm rates. In this paper, in order to improve the VAD performance, harmonic-weighted energy is proposed. This feature extraction method focuses on voiced speech intervals and weighted harmonic-to-noise ratios to determine the amount of the harmonicity to frame energy. For performance evaluation, the receiver operating characteristic curves and equal error rate are measured.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.5
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• pp.287-294
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• 2018

Mandibular third molar extraction is commonly performed in dental clinics. However, the optimal method of anesthesia has not been established for this procedure. The conventional inferior alveolar nerve block is the most widely used method. However, its success rate is not high and it may lead to complications, such as aspiration and nerve injury. Therefore, various anesthesia methods are being investigated. Articaine has been proven to be efficacious in a number of studies and is being used with increasing frequency in clinical practice. In this review article, we will briefly review various local anesthesia techniques, anesthetics, and a computer-controlled local anesthetic delivery (CCLAD) system, which reduces pain by controlling the speed of drug injection, for mandibular third molar extraction.