• Journal of the Korean Home Economics Association
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• 제39권4호
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• pp.49-59
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• 2001

Natural red and yellow dyestuff was extracted from safflower (Carthamus tinctorius Linnaeus) by a new process of cellulase extraction compared with the conventional hot water extraction. Dyestuffs were extracted from safflower easily and repeatedly by means of cellulose as safflower cell wall destroyer. It means that new dyestuff extraction by cellulase improves not only yields of dyestuff from safflower successfully but also the rate of repetition of extraction. From the above experiments, the conclusions of this study were summarized as follows. 1. The optimum conditions of dyestuff extraction from safflower by general extraction method were that the solvent was the water of pH 6.0 on yellow dyestuff and 3% $K_2CO_3$ solution on red dyestuff, extraction temperature was $55^{\circ}C$, and extraction time was 30 min. 2. Among various cellulase, the NOVO cellulase was the best cell wall destroyer of safflower and finally produced the largest amount of dyestuff from safflower by cellulase extraction method. 3. The optimum conditions of dyestuff extraction by cellulase extraction method were conducted on 10 unit of cellulase per gram of safflower at $100m{\ell}$ water of pH 5.0 at $50^{\circ}C$ for 30 min.

• Journal of the Korean Chemical Society
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• 제42권1호
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• pp.36-41
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• 1998

In this study, the extraction of Co(Ⅱ) and Cu(Ⅱ) into chloroform solution of dithizone, distribution ratios, extractabilities and extraction rate constants of the metal complexes were compared in each case with which thiocyanate ion was or not used as the auxiliary ligand. The use of the thiocyanate ion increased threefold the distribution ratio for Co(Ⅱ) complex in a basic solution and twofold for Cu(Ⅱ) complex in a wide pH range. And the extractability was also augmented from about 90 to 99 for Co(Ⅱ) and from 95 to 99 for Cu(Ⅱ) in a given period. The extraction rate constants were $k_1\;:\;1.2{\times}10^5$, $k_2\;:\;1.34{\times}10^{17}\; mol^{-1}dm^3s^{-1}$ in case of Co(Ⅱ) and$k_1\;:\;1.1{\times}10^8$, $k_2\;:\;2.83{\times}10^{10}\; mol^{-1}dm^3s^{-1}$ in case of Cu(Ⅱ) on the extraction of dithizonate complexes into chloroform solution.

• Journal of the Korean Society of Food Science and Nutrition
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• 제29권5호
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• pp.790-795
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• 2000

To establish the optimum conditions for the extraction of anthocyanin pigment from purple-fleshed sweet potato, a suitable extraction solvent with the optimum citric acid concentration for acidification of the solvent, and the optimum extraction time and temperature were determined. Twenty percent ethanol solution acidified with citric acid was found to be a good solvent for the extraction of the pigment from purple-fleshed sweet potato. About 10 hour extraction at room temperature was appropriate for the extraction. pH of the extract was below 3 when more than 0.7% citric acid was added. The higher the concentration of citric acid added was, the higher the total optical density (TOD) of the extract was. However, the increase in TOD of the extract was insignificant when more than 1% of citric acid was added. Therefore, addition of 1% citric acid was determined for acidification of the extracting solvent. Though the initial rate of the pigment extraction increased as the extracting temperature increased, extraction at higher temperatures of 60 or 8$0^{\circ}C$ for an extended time caused a decrease in the extraction yield due to degradation of the pigment. The optimum extraction temperature for the anthocyanin pigment from purple-fleshed sweet potato with the solvent used was determined as 4$0^{\circ}C$.

• International Journal of Safety
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• 제4권2호
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• pp.30-35
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• 2005

In case of tunnel fire, one of the most effective facilities to save lives is the smoke control system. In this study, two different smoke extraction schemes of transversely ventilated tunnel were compared. One is the smoke extraction using the fixed exhaust ports on the false ceiling to achieve the uniform and distributed smoke extraction (uniform exhaust). The other is that using the remote controlled smoke extraction where only vents close to the fire is opened whereas the others are closed to enhance the limitation of the smoke spread (localized exhaust). A number of numerical simulations were performed to find out the optimal smoke extraction rate at each smoke extraction scheme to allow the tunnel users to escape to the safe area without endangering their lives by smoke.

• The Korean Journal of Food And Nutrition
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• 제12권4호
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• pp.358-363
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• 1999

This study was conducted to evaluate the extraction methods for the determination of antioxidants in soybean oil. Recovery rates of various antioxidants in soybean oil showed similar rates as 80.4~102.1% by solvent/solvent extraction method and 89.9~106.4% by sweep co-distillation method except 46.6~61.2% of PG at corresponding spiked concentractions. The maximun recovery rates of antioxidnts were obtained when extraction time and extraction temperature used in UNITREX were 20min and 21$0^{\circ}C$ respectively. In the recovery rates with the activation of florisil when 2% ofwater was added to florisil the highest recovery rates for TBHQ, BHA, BHT were obtained by sweep co-distillation met-hod. Therefore sweep co-distillation method showed less solvent simple operation and high recovery rate compared with solvent/solvent extraction method.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• 제44권6호
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• pp.50-57
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• 2012

In this study, the beeswax extraction methods using organic solvents were examined to develop a optimal dewaxing technology for beeswax-treated Hanji. Thermally-aged beeswax-treated Hanji was dewaxed using four types of extraction methods including dipping, Soxhlet extraction, ultrasonic washing and shaking methods. Then, the aging stability of the dewaxed Hanji was evaluated in terms of variations in paper strength and in the color of the printed area with muk. The experimental results suggested that the dewaxing methods allowing solvent to flow during extraction showed superior extraction efficiency. The dipping method in which the organic solvent does not flow showed the slowest extraction rate of beeswax compared to three other methods. In terms of variations in tensile strength and folding endurance, however, no obvious differences in the aging stability were observed amongst these four extraction methods. Regarding the aging stability in terms of the color of the printed area with muk, Soxhlet extraction method showed the best performance of dewaxing.

• The korean journal of orthodontics
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• 제42권2호
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• pp.80-86
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• 2012

Objective: This study aimed to investigate the current data regarding age, sex, and Angle Classification of Korean orthodontic patients and influence of these factors on the tendency to undergo extraction and orthognathic surgery. Methods: The recent trends of Korean orthodontic patients were assessed using questionnaire survey. The questionnaires were e-mailed to orthodontists who met the study criteria; 58% of the orthodontists opened the e-mails, and 27.7% replied to the e-mails. In all, the medical records of 11,340 patients who underwent orthodontic treatment at private clinics and small dental hospitals in Korea were analyzed. Results: The percentage of female patients in the study sample was 69.6%, and the average age of the patients was 19.87 years. The percentage of patients who were older than 19 years was 50.2%. Class II and Class III malocclusions were noted in 33.6% and 23.6% of patients, respectively. Extraction and orthognathic surgery were performed in 60.4% and 6.9% of patients, respectively. Conclusions: The results showed that there were a high percentage of adult, Class II malocclusion and extraction patients in private practices and small dental hospitals during the study period. Further, a relatively high proportion of adult patients opted to undergo orthognathic surgery.

• Nuclear Engineering and Technology
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• 제53권11호
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• pp.3798-3807
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• 2021

Tritium extraction from radioactively contaminated cement mortar samples was performed using heating and liquid scintillation counting methods. Tritiated water molecules (HTO) can be present in contaminated water along with water molecules (H₂O). Water is one of the primary constituents of cement mortar dough. Therefore, if tritium is present in cement mortar, the buildings and structures using this cement mortar would be contaminated by tritium. The radioactivity level of the materials in the environment exposed to tritium contamination should be determined for their disposal in accordance with the criteria of low-level radioactive waste disposal facility. For our experiments, the cement mortar samples were heated at different temperature conditions using a high-temperature combustion furnace, and the extracted tritium was collected into a 0.1 M nitric acid solution, which was then mixed with a liquid scintillator to be analyzed in a liquid scintillation counter (LSC). The tritium extraction rate from the cement mortar sample was calculated to be 90.91% and 98.54% corresponding to 9 h of heating at temperatures of 200 ℃ and 400 ℃, respectively. The tritium extraction rate was close to 100% at 400 ℃, although the bulk of cement mortar sample was contaminated by tritium.

• Analytical Science and Technology
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• 제21권5호
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• pp.392-396
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• 2008

Acer tegmentosum is a tree used to treat various liver diseases in Korea. There have been some concern regarding the safety of Acer tegmentosum due to some toxic chemical compounds in its stems. Supercritical fluid extraction (SFE) was employed to develop a removing method of toxic compounds from Acer tegmentosum. The toxic compounds were effectively extracted with ethanol modified supercritical fluid $CO_2$. The optimum condition of SFE was 100 bar of pressure, $40^{\circ}C$ of extraction temperature, 3 mL/min of $CO_2$ flow rate, 0.2 mL/min of modifier (ethanol) flow rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제29권6C호
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• pp.901-906
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• 2004

For a digital image watermarking some autostereograms are used such as random dot images. In there, the extraction efficiency is good and the distortion rate is low. In this paper, we shall select an optimized scaling parameter which derives low distortion rate and high extraction efficiency, when we use a random dot images as like as autostereograms into some images except for extremely biased gray level images.