• Title/Summary/Keyword: period-2 solution

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Removal Efficiency of Pesticide Residues on Apples by Ultrasonic Cleaner (초음파 세척기를 이용한 사과의 잔류농약 제거 효과)

  • Yoon, Chae-Hyuk;Park, Woo-Churl;Kim, Jang-Eok;Kim, Chung-Hyo
    • Korean Journal of Environmental Agriculture
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    • v.16 no.3
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    • pp.255-258
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    • 1997
  • In order to determine the removal efficiency of pesticide residues on apples by ultrasonic cleaner, apples(Fuji var.) were artificially treated by dipping in water solution of fenitrothion EC, chlorpyrifos EC and phenthoate EC. The treated apples were washed by the ultrasonic cleaner with water, 30% ethanol solution or 0.2% detergent solution, respectively. The removal efficiency of fenitrothion, chlorpyrifos and phent-hoate by ultrasonicated washing in water for 0.5min. was 39.2%, 32.0% and 50.4%, respectively, but there was a tendency to decrease the removal efficiency of the pesticide residues as the duration of ultrasonicated washing period is increased. The maximum removal efficiency of the pesticide residues washed in the detergent solution was observed by ultrasonicated washing the samples for 5min. and it was recorded as 33.5% ; fenitrothion, 30.1% ; chlorpyrifos and 48.3% ; phenthoate, respectively. However it's appeared that the longer the ultrasonicated washing period in 30% ethanol solution the more pesticides from the apples were removed and the maximum removal efficiency of the pesticides was recorded as 66.2%(fenitrothion ; washed for 15min.), 41.7%(chlorpyrifos ; washed for 10min.), 74.2%(phenthoate ; washed for 10min.).

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Effect of bark on the adsorption of heavy metal ions (2) - Effect of Pinus densiflora and Quercus mongolica barks on the adsorption of Cu and Cd ions - (수피(樹皮)에 의(衣)한 중금속(重金屬) 흡착효과(吸着效果)(2) - 소나무와 신갈나무 수피(樹皮)에 의한 Cu와 Cd의 흡착효과(吸着效果) -)

  • Paik, Ki-Hyon;Kim, Kyung-Jik
    • Journal of the Korean Wood Science and Technology
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    • v.14 no.4
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    • pp.1-7
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    • 1986
  • This investigation involves a study of the physical and chemical factors of Pinus densiflora SIEB. et ZUCC. and Quercus mongolica Fisher barks affecting on the adsorption of heavy mteal ions. The results obtained can be summarized as follows. 1. The capacity of the untreated bark to remove the Cu and Cd from solution was similar to or 5% higher than that of formaldehyde treated bark in both species. Considering that untreated bark lead to color-leaching problem, bark treated with formaldehyde are economical. 2. With decreasing particle size of bark(20-80), the adsorption ratio of the Cu and Cd from solution was increased. Quercus bark adsorbed more Cu and Cd at smaller particle size compared to Pinus bark. 3. The heavy metal eqilibrium adsorption of the bark from Cu and Cd solution was attained within 10 min. Pinus bark removed about 48% of the Cu and 41% of the Cd from solution in 10 min while Quercus bark removed about 50% during that period. 4. As the initial metal concentration increased. the absolute metal uptake was increased while percentage removal was decreased. At the lower metal concentration (10 ppm). Pinus and Quercus barks removed 77-94% of the Cu and 72-84% of the Cd. At high metal concentration (200 ppm), the adsorption ratio was 40% Cu and 25% Cd, respectivelty. 5. The maximum adsorption of the Cu and Cd from solution was obtained at pH 5-6 in filtrate. 6. With increased bark weight per given metal concentration, absolute removal of metal ion from solution was increased, but the percentage removal was decreased. The amount of adsorption was 4.2 mg Cu and 4.2 mg Cd per gr. Pinus, bark and 5.4 mg Cu and 4.3 mg Cd per gr. Quercus bark, respectively.

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High-Temperature Drying of Bamboo Tubes Pretreated with Polyethylen Glycol Solution

  • Kang, Chun-Won;Chung, Woo-Yang;Han, Jae-Ok;Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.2
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    • pp.139-146
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    • 2017
  • This study was conducted to develop a new drying technology in order to quickly and massively dry bamboo tubes without crack and check. The bamboo tubes with the diameter of 45 mm - 68 mm had been impregnated in the solution of PEG-1000, and then were dried under room temperature and high temperature, respectively. The cracks occurred on all control specimens while no cracks were found on PEG treated specimens during drying at room temperature due to effect of PEG restraining the circumferential shrinkage of bamboo tube. But the drying period of this method was too long (200 days) compared to 10 hours of kiln drying. During fast high temperature drying, cracks occurred on all control specimens, but no cracks were found on PEG treated specimens, which could be accounted for more solidified PEG due to higher drying temperature and faster drying rate, and the tension set formed on the surface of bamboo tube in the early stage of drying owning to high drying temperature and low relative humidity. Thus, it is advised that PEG treated bamboo tube should be fast dried at high temperature in order to not only prevent crack or check in short drying period but also increase the dimensional stability of the products made of bamboo tubes.

Surgical Management for Esophageal Perforation: A Report of Eleven Cases (식도천공에 대한 외과적 치료 (11례))

  • 이건우
    • Journal of Chest Surgery
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    • v.2 no.2
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    • pp.147-154
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    • 1969
  • This is a report on a total of 11 cases of esophageal perforation in the department of thoracic surgery, Chonnam University Hospital during the period of 8 years from 1962 to 1969. They occurred by the following agents, that is,lye solution[7 cases], fish bone[2 cases]. compress air [one case], strong acid [one case]. The perforated portions of esophagus were cervical esophagus in 2 cases, upper third of esophagus in 5 cases, middle third of esophagus in 3 cases and lower third of esophagus [abdominal esophagus] in one case. 4 cases out of cases of esophageal perforation after ingestion of Lye solution were due to Bougination to improve esophageal stenosis: 2 cases occurred 2 months after ingestion of Lye solution and the remaining 2 cases, 2 to 3 weeks after Lye solution ingestion. Therefore, It is realized that Bougination for esephageal stricture by Lye solution is particularly dangerous. The complication after esophageal perforation were mediastinitis,[10 cases], right pyothorax with mediastinitis [8 cases], peritonitis [4 cases], esophago-bronchial fistula[one case]. Owing to the various complications above mentioned, surgical approach to esophageal perforation is accordingly complicated and a combination of more than two of the following different procedures were properly used case by case, that is. gastrostomy or jejunostomy for feeding and esophageal rest,thoracotomy and chest drainage, lung decortication for pyothorax, primary closure of compress air perforation and esophago-bronchial fistula, mediastinostomy, retrosternal esophagoplasty using right colon to Lye stricture etc. 5 cases[45. 5%] of 11 cases were expired and the rest of 6 cases[54.5%]were survived with complete accomplishment of surgical procedures and satisfactory healing in 4 cases and interruption of follow up in 2 cases because of poor economical condition of the patients.

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Dispersion Characteristics of Zinc Oxide Nanoparticles in Ionic and Non-ionic Isotonic Solution (이온성 및 비이온성 등장액 용매에서 산화아연나노입자의 분산 특성)

  • Choi, Jonghye;Kim, Hyejin;Park, Kwangsik
    • YAKHAK HOEJI
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    • v.57 no.4
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    • pp.282-288
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    • 2013
  • Zinc oxide nanoparticles (ZnONPs) are widely used in a variety of products and cosmetic products including paper, paints, plastics and sunscreen. However, information on the safety of ZnONPs are not enough and many publications suggest possible toxic effects on environmental and human health. Furthermore, physico-chemical characteristics of nanoparticles makes it hard to test toxicity using the test guidelines of chemicals adopted by regulatory bodies. In this study, stability of ZnONPs was investigated using different types of isotonic solution, which is important in the toxicity study of intravenous route. Precipitation, aggregation, size, zeta potential and morphology of ZnONPs were evaluated with different times and concentrations. Precipitation of ZnONPs were observed in ionic isotonic solution including phosphate-buffered saline, Kreb's-Ringer solution, physiological salt solution and cell culture media of DMEM (Dulbecco's Modified Eagle's Medium) with 10% fetal bovine serum. On the other hand, they were stable without precipitation in non-ionic isotonic solution such as 5% glucose and 2% glycerol, respectively, which are biocompatible for intravenous injection. The average size of ZnONPs in 5% glucose and 2% glycerol was stably maintained, which is less than 30 nm and very similar as that in water dispersion of ZnONPs, provided by the manufacturer. The stability was maintained during the experimental period of 5 days and diluted state up to 15,000 ppm. These data suggest that 5% glucose and 2% glycerol solution can be used for the vehicles of ZnONPs in the toxicity study of intravenous injection route.

Homogeneous Catalysis (IV). Hydrogenation of Acrylonitrile with trans-Chlorocarbonylbis(triphenylphosphine)rhodium(I)

  • Woo, Jin-Chun;Chin, Chong-Shik
    • Bulletin of the Korean Chemical Society
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    • v.4 no.4
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    • pp.169-171
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    • 1983
  • It has been found that the acrylonitrile solution of trans-$RhCl(CO)(Ph_3P)_2$ produces propionitrile catalytically at $90^{\circ}C$ under $P_{H_2}$=3 atm. This catalytic hydrogenation proceeds only for a certain period of time producing ca. 50 moles of propionitrile per mole of the rhodium complex. The hydrogenation with trans-$RhCl(CO)(Ph_3P)_2$ in the presence of formaldehyde is much faster than in the absence of formaldehyde, and continues without a decrease in the rate for a prolonged period of time. It is suggested that the hydrogenation with trans-$RhCl(CO)(Ph_3P)_2$ proceeds through the unsaturated route initiated by the dissociation of CO from trans- $RhCl(CO)(Ph_3P)_2$ to give coordinatively unsaturated $RhCl(Ph_3P)_2$.

Optimum Nutrient Solution Strength for Korean Strawberry Cultivar 'Daewang' during Seedling Period (국내 육성 신품종 딸기 '대왕'의 육묘기 적정 배양액 농도)

  • Jun, Ha Joon;Jeon, Eui Hwan;Kang, Soo In;Bae, Geun Hye
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.812-818
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    • 2014
  • Raising seedlings is important for fruit crops and is especially significant for strawberries as it accounts for 80% of their cultivation. However, there are few studies on raising seedlings of strawberries by hydroponics. Since strawberries show clear differences in growth characteristics based on cultivar, it is necessary to develop suitable fertilizer formula, concentration and pH for each cultivar, and also to examine the amount of nutrient feeding appropriate for each medium type. A key to raising seedlings of strawberries by hydroponics is the development of strategies to manage the concentration of nutrient solution. The mother plants of 'Daewang' strawberries were planted on hydroponics benches filled with cocopeat on March 28, 2012. Three nutrient solution treatments were employed during the term of raising seedlings: a type that supplied EC $0.6dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [0.6 (30) + 20]; a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 30 days and only water for 20 days [1.2 (30) + 20]; and a type that supplied EC $1.2dS{\cdot}m^{-1}$ nutrient solution for 50 days [1.2 (50)]. The plants were then planted on hydroponics benches filled with cocopeat on September 20, and managed with EC $0.6-0.8dS{\cdot}m^{-1}$ strawberry nutrient solution developed by Yamazaki. After planting, shoot growth, flowering rate and fruit quality of the first cluster were investigated. The petiole length, leaf length, leaf width and crown diameter showed the highest grown in the [1.2 (50)] treatment, followed by [1.2 (30) + 20], and then [0.6 (30) + 20], indicating that the higher concentration of nutrient solution was preferable for raising seedlings. However, the growth differences among treatments gradually disappeared as growth continued, and the crown diameter especially grew to exhibit almost no difference at all among treatments. The point of flowering came first in [0.6 (30) + 20], followed by [1.2 (30) + 20] and then [1.2 (50)]. The [0.6 (30) + 20] treatment showed much earlier flowering than other treatments, which implies that low-concentration nutrient solution may be beneficial to the flowering of 'Daewang' strawberries while raising seedlings. There was no statistically significant difference among treatments in fruit length, fruit diameter and fruit firmness. Fruit weight in [1.2 (50)] treatment was significantly higher than other treatments. However, soluble solids of fruit was the lowest in [1.2 (50)] treatment. Together, the results of this experiment imply that it is better to supply EC $0.6dS{\cdot}m^{-1}$ solution for 30 days and then supply only water for 20 days to adequately manage concentration of nutrient solutions during the period of raising seedlings of strawberries by hydroponics.

The Effect of Imidazole and 2-Methyl Imidazole on the Corrosion of Mild Steel in Phosphoric Acid Solution

  • Chandrasekara, V.;Kannan, K.;Natesan, M.
    • Corrosion Science and Technology
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    • v.4 no.5
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    • pp.191-200
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    • 2005
  • Two azole compounds viz., Imidazole (IM) and 2-Methylimidazole (2-MIM) were studied to investigate their inhibiting action on corrosion of mild steel in phosphoric acid ($H_3PO_4$) solution by mass loss and polarization techniques at 302K-333K. It has been found that the inhibition efficiency of the all inhibitors increased with increase in inhibitor concentration and decreases with increasing temperature and also with increase in acid concentrations. The inhibition efficiency of these compounds showed very good inhibition efficiency. At 0.5% of IM and 2-MIM in 1N and 5N phosphoric acid solution at 302K to 333K for 5 hours immersion period, the inhibition efficiency of 2-Methylimidazole found to be higher than Imidazole. The adsorption of these compounds on the mild steel surface from the acids has been found to obey Tempkin's adsorption isotherm. The values of activation energy ($E{\alpha}$) and free energy of adsorption (${\Delta}G{\alpha}ds$) were also calculated. The plots of log $W_f$ against time (days) at 302K give straight line which suggested that it obeys first order kinetics and also calculate the rate constant k and half life time $t_{1/2}$. Surface was analyzed by SEM and FITR spectroscopy.

A Study on the Quality and Sensory Characteristics of Ginseng Pickles(JJangachi) (인삼 절임식품의 품질 및 관능특성에 관한 연구)

  • Lee, Kum-Hee;Shin, Kyung-Eun;Rha, Young-Ah;Choi, Soo-Keun
    • Culinary science and hospitality research
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    • v.19 no.2
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    • pp.65-75
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    • 2013
  • The purpose of this study is to investigate the quality and sensory characteristics of ginseng Jeolim, or ginseng pickles. The moisture contents of ginseng pickles decreased significantly with increase in soy sauce and in storage period. The L-value of pickle solution decreased significantly with increase in soy sauce and in storage period while its a-value and b-value increased significantly with increase in soy sauce and in storage period. The salinity and sugar contents of pickle solution increased significantly with increase in soy sauce; however, they decreased with increase in storage period. The pH of pickle solution decreased significantly with increase in soy sauce and in storage period. As the results of acceptance test, apparence, flavor, taste, texture, and overall acceptance were higher in C3. In conclusion, ginseng Jeolim showed great preference with adding soy sauce, and the preference has increased with 20% of soy sauce added and 14 day storage period.

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Optimization of Tank Model Parameters Using Multi-Objective Genetic Algorithm (II): Application of Preference Ordering (다목적 유전자알고리즘을 이용한 Tank 모형 매개변수 최적화(II): 선호적 순서화의 적용)

  • Koo, Bo-Young;Kim, Tae-Soon;Jung, Il-Won;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
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    • v.40 no.9
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    • pp.687-696
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    • 2007
  • Preference ordering approach is applied to optimize the parameters of Tank model using multi-objective genetic algorithm (MOGA). As more than three multi-objective functions are used in MOGA, too many non-dominated optimal solutions would be obtained thus the stakeholder hardly find the best optimal solution. In order to overcome this shortcomings of MOGA, preference ordering method is employed. The number of multi-objective functions in this study is 4 and a single Pareto-optimal solution, which is 2nd order efficiency and 3 degrees preference ordering, is chosen as the most preferred optimal solution. The comparison results among those from Powell method and SGA (simple genetic algorithm), which are single-objective function optimization, and NSGA-II, multi-objective optimization, show that the result from NSGA-II could be reasonalby accepted since the performance of NSGA-II is not deteriorated even though it is applied to the verification period which is totally different from the calibration period for parameter estimation.