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The Effect of Hydraulic Retention Time on The Power Density in a Horizontal Flow Microbial Fuel Cell (수평 흐름형 미생물 연료전지에서 수리학적 체류시간이 전력수율에 미치는 영향)

  • Lee, Chae-Young;Park, Su-Hee;Woo, Jeong-Hei;Yoo, Kyu-Seon;Jeong, Jea-Woo;Song, Youn-Chae
    • Journal of the Korea Organic Resources Recycling Association
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    • v.19 no.1
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    • pp.109-114
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    • 2011
  • This study was conducted to investigate the effect of hydraulic retention time(HRT) on the power density in a horizontal flow microbial fuel cell(MFC) reactor. When HRTs were 15min, 30min, 60min and 180min, maximum power densities were $24.7mW/m^2$, $27.3mW/m^2$, $22.8mW/m^2$ and $17.2mW/m^2$, respectively. The highest power density was obtained at HRT of 30min. It was 59% improvement when compared to the power density at an HRT of 180min. When HRT was increased, COD removal rate increased whereas the coulombic efficiency remained constant. The result shows that the optimal performance of the horizontal flow MFC reactor could be achieved at HRT of 30min.

The Respiratory and Hemodynamic Effects of Prone Position According to the Level of PEEP in a Dog Acute Lung Injury Model (잡종견 급성폐손상 모델에서 Prone position 시행시 PEEP 수준에 따른 호흡 및 혈류역학적 효과)

  • Lim, Chae-Man;Chin, Jae-Yong;Koh, Youn-Suck;Shim, Tae-Sun;Lee, Sang-Do;Kim, Woo-Sung;Kim, Dong-Soon;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.140-152
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    • 1998
  • Background: Prone position improves oxygenation in patients with ARDS probably by reducing shunt Reduction of shunt in prone position is thought to be effected by lowering of the critical opening pressure (COP) of the dorsal lung because the pleural pressure becomes less positive in prone position compared to supine position. It can then be assumed that prone position would bring about greater improvement in oxygenation when PEEP applied in supine position is just beneath COP than when PEEP is above COP. Hemodynamically, prone position is expected to attenuate the lifting of cardiac fossa induced by PEEP. Based on these backgrounds, we investigated whether the effect of prone position on oxygenation differs in magnitude according to the level of PEEP applied in supine position, and whether impaired cardiac output in supine position by PEEP can be restored in prone position. Methods: In seven mongrel dogs, $PaO_2/F_1O_2$(P/F) was measured in supine position and at prone position 30 min. Cardiac output (CO), stroke volume (SV), pulse rate (PR), and pulmonary artery occlusion pressure (PAOP) were measured in supine position, at prone position 5 min, and at prone position 30 min. After ARDS was established with warmed saline lavage(P/F ratio $134{\pm}72$ mm Hg), inflection point was measured by constant flow method($6.6{\pm}1.4cm$ $H_2O$), and the above variables were measured in supine and prone positions under the application of Low PEEP($5.0{\pm}1.2cm$ $H_2O$), and Optimal PEEP($9.0{\pm}1.2cm$ $H_2O$)(2 cm $H_2O$ below and above the inflection point, respectively) consecutively. Results : P/F ratio in supine position was $195{\pm}112$ mm Hg at Low PEEP and $466{\pm}63$ mm Hg at Optimal PEEP(p=0.003). Net increase of P/F ratio at prone position 30 min, however, was far greater at Low PEEP($205{\pm}90$ mm Hg) than at Optimal PEEP($33{\pm}33$ mm Hg)(p=0.009). Compared to CO in supine position at Optimal PEEP($2.4{\pm}0.5$ L/min), CO in prone improved to $3.4{\pm}0.6$ L/min at prone position 5 min (p=0.0180) and $3.6{\pm}0.7$ L/min at prone position 30 min (p=0.0180). Improvement in CO was attributable to the increase in SV: $14{\pm}2$ ml in supine position, $20{\pm}2$ ml at prone position 5 min (p=0.0180), and $21{\pm}2$ ml at prone position 30 min (p=0.0180), but not to change in PR or PAOP. When the dogs were turned to supine position again, MAP ($92{\pm}23$ mm Hg, p=0.009), CO ($2.4{\pm}0.5$ L/min, p=0.0277) and SV ($14{\pm}1$ ml, p=0.0277) were all decreased compared to prone position 30 min. Conclusion: Prone position in a dog with saline-lavaged acute lung injury appeared to augment the effect of relatively low PEEP on oxygenation, and also attenuate the adverse hemodynamic effect of relatively high PEEP. These findings suggest that a PEEP lower than Optimal PEEP can be adopted in prone position to achieve the goal of alveolar recruitment in ARDS avoiding the hemodynamic complications of a higher PEEP at the same time.

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A Study On Crystalline Structure Change by Isothermally Annealed after Elevated heating of drawn PP filaments (연신한 PP filament의 승온열처리에 의한 결정구조 변화에 관한 연구)

  • Lee, Eun-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.3 no.4
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    • pp.345-351
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    • 2000
  • The change of crystalline structure of drawn PP filaments were investigated. Samples were treated by isothermally annealed after elevated heating from $20^{\circ}C$. Measurements were carried out with XRD for crystallite size and density gradient tube for crystallinity. Isothermally heat treatment were carried out at the temperature of $100^{\circ}C$, $120^{\circ}C$ and $140^{\circ}C$ for 10min., 30min. and 60min. in dry oven. The isothermal heat treatment after elevated heating from $20^{\circ}C$ were carried out at the temperature of $100^{\circ}C$, $120^{\circ}C$ and $140^{\circ}C$ for 10min., 30min. and 60min. with heating rate of $1^{\circ}C$/min., $5^{\circ}C$/min. and $10^{\circ}C$/min. From the results of this study, it found the following facts. It was found that the crystallinity and crystallite size of (110) plane of sample were increased with increasing of annealed temperature and time. Also crystallinity and crystallite size of samples which were isothermally annealed after elevated heating from $20^{\circ}C$ were higher than those of isohtermally annealed samples.

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A Study On the Mechanical Properties of Isothermally Annealed after Elevated heating of drawn PP filaments (연신후 승온열처리한 PP filament의 역학적 성질에 관한 연구)

  • Lee, Eun-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.5 no.4
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    • pp.361-366
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    • 2002
  • The change of mechanical properties of drawn PP filaments which was treated by isothermally annealed after elevated heating. Measurements were carried out with UTM for mechanical properties. Isothermally heat treatment were carried out $100^{\circ}C$, $120^{\circ}C$, $140^{\circ}C$ for 10min., 30min., 60min, in silicon oil bath. And isothermally heat treatment after elevated heating from $20^{\circ}C$ were carried out $100^{\circ}C$, $120^{\circ}C$, $140^{\circ}C$ for 10min., 30min., 60min., with heating rate of $1^{\circ}C/min$., $5^{\circ}C/min$., $10^{\circ}C/min$. From the results of this study, it found the following facts. Initial modulus and tensile strength were increased with increasing of annealed temperature and time. Also initial modulus of tensile strength of samples which were isothermally annealed after elevated heating from $20^{\circ}C$ were higher than those of isothermally annealed samples.

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A Study on the Influence of Sulphur-compound to Vitamin C in the different Vegetable during Cooking (유황화합물질이 조리시 야채류중의 Vitamin C 함량에 미치는 영향에 대하여)

  • 임양순
    • Journal of the Korean Home Economics Association
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    • v.12 no.1
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    • pp.472-479
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    • 1974
  • In order to study the influence of sulphur-compound on the vitamin C contents of different vegetables-i.e. Korean green pepper, leaf, Bilum, leaf, Soybean sprouts, Mung bean sprouts, Cucumber-the garlic powder and minced garlic were used while the vegetables were cooked. The results garlic juice during scaling the vegetables the vitamin C contents of them were higher as much as 9.2~12.7% 2. When the scaled vegetables were seasoned the vitamin C contents were higher as much as 8.9~`17.5% by adding garlic powder and 7.3~14.9% by adding minced garlic. 3. Vitamin C loss of the cooked vegetables with room condition for 30 min, was higher as much as 15.2~34.5% compared to just cooking. 4. Vitamin C contents of vegetables after 30 min from cooking, compared to just cooking were higher of vegetables after 30 min from cooking, compared to just cooking were higher as much as shown below. 1) ~13.3% by adding garlic powder. 2) 4.0~9.3% by adding minced garlic.

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Separation and Characteristics of the Extract Solution from Ginseng Marc by Roasting Process (볶음처리로 생성된 인삼박 추출액의 분리와 특성)

  • 박명한;김영호
    • Journal of Ginseng Research
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    • v.19 no.2
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    • pp.153-159
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    • 1995
  • Roasting ginseng marc was roasted at different temperatures (140, 170, 200, 23$0^{\circ}C$) and for different periods (10, 20, 30 min) produced aqueous soluble brown pigments, gel filtration of which over Sephadex G-50 yielded 3 fractions A, B, C. The treatment at higher temperature and for longer time lead to increase of peak A and decrease of peak C. The contents of the brown pigments and the degree of brown color increased about 4 times and over 6 times, respectively, by roasting at 23$0^{\circ}C$ and for 30 min as compared to the control. 5-Hydroxymethyl furfural in aqueous and 50% ethanol extracts of treated samples at 23$0^{\circ}C$ and for 30 min was increased to 3.6 times and 8 times, respectively, and carbonyl compound in both aqueous and 50% ethanol extracts was increased 3 times. Also pyroxene-like substance was increased apparently in both aqueous and 50% ethanol extracts of treated samples.

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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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The Study for the characteristics of mechanically and thermally treated PET films (기계적 및 열적 처리된 PET 필름의 특성에 관한 연구)

  • 이종영;노지영;박성수
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.5
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    • pp.197-202
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    • 2001
  • The influence of thermal treatment and cold drawing was investigated for poly(ethy1ene terephthalate) films fabricated with various experimental conditions. Samples were elongated at room temperature under stepwise-drawing condition with the cross-head speed kom 0.5 to 500 mrdmin in an universal tester. Stress oscillation was observed in the stress-stnin curve of the samples heat-treatd at 50, 72 and $129^{\circ}C$ for 30 min, but it was not observed in the samples heat-treatd at $83^{\circ}C$ for 30 min. Thermal analyses of the samples were carried out in differential scanning calorimeter at the heating rate df $10^{\circ}C$/min/min, and the glass transition temperature, crystallization peak, enthalpy of fusion and degree of crystallinity were measured. The dynamic mechanical analyses of the samples were also carried out in a multiplefimction internal kiction pendulum at 1 Hz with the heating rate of $1.5^{\circ}C$/min, and it was found that the elastic modulus increases in the order of non-treated, heat-treated, and elongated samples.

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