• 펄프종이기술
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• 제45권5호
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• pp.64-70
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• 2013

In this study, the effect of soxhlet extraction on dewaxing of the aged beeswax-treated paper was examined. To do this, soxhlet extraction of the aged beeswax-treated paper performed with different reflux conditions and then measured the dewaxing efficiency and change in the various properties such as tensile strength, folding endurance, color and brightness. Also, an artificial aging test was executed in order to investigate the effect of soxhlet extraction on the preservability of the dewaxed paper. As the result of FT-IR analysis, a peak area of CH and COOH group, which are main band of beeswax, was decreased or removed after soxhlet extraction. The decreasing rate of each peaks were increased depending on reflux time. After dewaxing, the physical property such as MIT type folding endurance and tensile strength was decreased. And $L^*$ value and brightness were increased while $a^*$ and $b^*$ value were decreased due to the remove of color compounds in beeswax. The more color deviation (${\Delta}E$) is expected with higher reflux times. As the result of artificial aging, preservability of two dewaxed papers except of DP_SE(C) sample was higher than that of untreated paper i.e. beeswax-treated paper.

• Fisheries and Aquatic Sciences
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• 제15권4호
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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.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2004년도 춘계임시총회 및 제23회 학술대회
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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.

• 한국대기환경학회지
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• 제34권1호
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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.

• 한국식품영양학회지
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• 제7권4호
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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.

• 한국산학기술학회논문지
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• 제4권2호
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• pp.114-119
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• 2003

본 연구는 폐수로부터 몇 가지의 유기오염물(Phenol, 2-Chlorophenol, Nitrobenzene)을 비분산 용매추출법으로 동시 제거하는 실험이다. 몇 가지의 용매(MIBK, IPAc, Hexane)에 대하여 분배계수를 구하였고, 용매와 폐수사이의 향류와 병류 흐름에 의한 추출 실험을 하였다. 수용액상의 유량이 증가함에 따라 용매와의 접촉시간이 짧아져 제거율이 떨어지고, 용매의 유량이 증가함에 따라 제거율이 증가함을 알 수 있었다. 그리고 병류보다는 향류에서 유기오염물의 제거율이 증가하는 것을 알 수 있었다. 이러한 결과를 토대로 유기오염물만이 아닌 다른 중금속 오염물 둥도 처리할 수 있는 산업용 폐수처리장치의 개발을 위한 기초자료로 쓰일 수 있다.

• Journal of Information Processing Systems
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• 제2권1호
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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.

• 대한영양사협회학술지
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• 제4권1호
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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.

• 한국환경과학회지
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• 제6권2호
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• pp.133-139
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• 1997

말로네이트 제조 공정에서 발생되는 폐액으로부터 용매추출법을 적용하여 코발트 회수 연구를 하였다 용매 추출에서의 주요 변수는 용매의 선택, pH, 코발트 농도, 역추출 온도 등이며 이러한 변수들의 영향을 조사하였다. 용매로써 DEHPA와 PC88A가 사용되었으며 이들 용매의 평형추출 곡선을 구하였다. 공장설계 조건을 찾기 위하여 Mccabe-Tiele 선도를 작성하였고, 연속 공정인 믹서-세틀러 장치를 가동하였다. 본 연구 결과 폐액 중에서 코발트는 99.9% 이상 회수되었고, 회수된 황산코발트의 순도는 99.9% 이상이었다.

• 말소리와 음성과학
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• 제5권1호
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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.