• Title/Summary/Keyword: keeping temperature

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Changes of multi-purpose solutions for soft contact lens depending on using period or keeping temperature (사용기간 및 온도에 따른 소프트콘택트렌즈 다목적용액의 변화)

  • Park, Mi-Jung;Ha, Ju-Ryung;Lee, Young-Min;Han, Hyeun-Woo;Kim, Seung-Tae
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.381-389
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    • 2004
  • To investigate changes of multi-purpose solutions for soft contact lens(MPS) depending on using period or keeping temperature, we evaluate four brands of MPS. No significant difference was seen in protein deposit removing efficacy after samples had used for 24 weeks and kept at $4^{\circ}C$, $20^{\circ}C$ or $30^{\circ}C$. The pH values of the samples of 4 brands measured weekly over the 24 week testing period. The initial average pH value of samples were 7.0, 7.5, 7.6 or 8.2. One brand of MPS was in the range of the threshold for ocular awareness, which is outside the zone of 6.6 ~ 7.8. During the testing period, the pH value were decreased in using period-dependent manner. At the 24th week, the average pH values of samples turned to 6.6, 7.2, 7.2 or 7.7. However, the difference of keeping temperature was not associated with decreased levels of pH values. After 24 weeks, one of total 36 samples was contaminated by bacteria. Furthermore, the change of components was shown after 24 weeks in the analysis using thin layer chromatography and the analysis of UV absorption pattern. The results of our study provides that the keeping temperature of MPS is not the important factor of changes of MPS, but the using period of MPS can cause contact lens wearers discomfort.

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A Study on the Performance Valuation of Small Size Water Storage Electric Boiler (소형 수축열식 전기 보일러의 성능 평가에 대한 연구)

  • Mo, Jong-Gun;Shin, Jae-Ho;Bae, Chul-Whan;Suh, Jeong-Se;Chung, Han-Sik;Jeong, Hyo-Min
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1524-1529
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    • 2003
  • We was made 150L an water storage electric boiler and obtained various performances of the storage, radiant and keeping by experimentation, The storage performance is that the heat were off about 50 minutes after heating start, Then the temperature of outlet was arrived the stead state at $91^{\circ}C$ and the storage performances was appeared 93.64%, In the radiant performance, the water temperature was decreased from $90^{\circ}C$ to $44.8^{\circ}C$ after 960 minutes, Then the calorific value changed from 675kcal/h to 72kcal/h and the temperature decreased about 50%, The keeping performance showed mean temperature, $67.06^{\circ}C$ according to progress 800 minutes and the maximum temperature drop were $0.2^{\circ}C$, By the results of the performance valuation, the water storage electric boiler was verified fitted quality on the test prescription of KERI(Korea Electrotechnology Research Institute).

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Bond Capacity of Near-Surface-Mounted FRP in Concrete Corresponding to Fire-Protection Method (콘크리트에 표면매립보강된 FRP의 내화단열방법에 따른 부착성능)

  • Lim, Jong-wook;Kim, Tae-hwan;Seo, Soo-yeon
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.35 no.1
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    • pp.3-10
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    • 2019
  • The purpose of this paper is to find the fire-protection method for keeping on the bond capacity of Near-Surface-Mounted (NSM) FRP under high temperature. Experiments have been carried out to evaluate the bond capacity of NSM FRP by using CFRP-plates and to confirm the heat transfer to the concrete block when the refractory insulation is attached to the surface of NSM FRP. Bond test of NSM FRP under room temperature was conducted to obtain the maximum bond strength. And then a heating tests were carried out with keeping the bond stress of 30% of the maximum bond strength. As a result, the bond capacity of NSM FRP was disappeared when the temperature at epoxy reached to its glass transition temperature (GTT). In order to secure the bond capacity of the NSM FRP, it is necessary to protect the front as well as side by using insulation materials.

Analytic Issues for Trend Management on Insulation Diagnositic for High Voltage Motors (고압전동기 절연진단 결과 추이관리의 문제점 분석)

  • Lee, Young-Jun;Ju, Young-Ho
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2052-2053
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    • 2008
  • High voltage motors are the core equipment of electric generation facilities and need to guarantee stable operation. Therefore, keeping healthy state is of importance by means of insulation diagnosis periodically. However, if the diagnosis went through in the different circumstances such as temperature, humidity, and impedance applied to the test equipment, the trend analysis have no significance. This paper presents the experimental results supporting the importance of keeping the same conditions under insulation diagnosis.

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Solar Energy Storage Effectiveness on Double Layered Single Span Plastic Greenhouse (2중 단동비닐하우스의 태양열 축열이용 효과)

  • Lee, Sung-Hyoun;Ryou, Young-Sun;Moon, Jong-Pil;Yun, Nam-Kyu;Kwon, Jin-Kyung;Lee, Su-Jang;Kim, Kyeong-Won
    • Journal of Biosystems Engineering
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    • v.36 no.3
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    • pp.217-222
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    • 2011
  • This study was carried out in order to reduce the amount of underground water which is used in the double layered single span plastic greenhouse for retaining heat. For this research, two plastic green houses of the double layered single span plastic greenhouse were installed. There was equipped of internal small tunnel for keeping warm air in the interior of the house. Then the internal small tunnel for keeping warm air was fitted with PVC duct of 50 cm in diameter filled with subsurface water. The surplus solar energy in the greenhouse was stored in the water in the PVC duct. Four FCUs (Fan Coil Unit), which has the capacity of 8,000 kcal per hour, were installed in the middle of the house, and a circulation motor in heat storage water tank was operated from 10:30 a.m. to 16:00 p.m. in order to circulate water between the water tank and the FCUs. Consequently about 5 degrees celsius could be maintained in the interior of the internal small tunnel for keeping warm air with the external temperature of lower than minus 5 degrees celsius. It appeared that the alteration of an internal temperature of the house was flexible depending on the sunlight during daytime. To prevent the water freezing, mixing antifreezing liquid in the water or operating FCU continuously was needed. Also, in order to use the surplus solar thermal energy on plastic green house of water curtain system efficiently, storing the surplus heat during daytime simultaneously finding a method of using water curtain systematic underground water happened to be important. As a result of this research, when the house's interior temperature is below zero the operation of FCU appeared to be impossible. Considering the amount of water used in the house with water-curtain-heating system is 150~200 ton per day, using the system mentioned in this research showed that reducing the underground water more than 80% in order to maintain the internal temperature as the level of 5 degree celsius at the extreme temperature of minus 5 degrees celsius.

MILD Combustion Characteristics with Inlet Air Velocity in a Conical Combustor (원추형 연소로에서 공기 유속에 따른 MILD 연소특성)

  • Kim, Tae-Kwon;Ha, Ji-Soo;Jo, A-Ron
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.6
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    • pp.774-779
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    • 2012
  • MILD (Moderate and Intense Low Oxygen Dilution) combustion is a technology that uses the recirculation of combustion gas to increase thermal efficiency not only by keeping down the concentration of Nitric Oxides and temperature but also by uniformizing the internal temperature of the combustion furnace. This study is a trial to obtain MILD combustion characteristics by adjusting the equivalence ratio with the air flow rate in the conical combustor while keeping the fuel flow rate and measuring the exhaust gas of the combustion furnace.

Study on the application of different water vapor spectra to quantify smoke gases with FT-IR (FT-IR을 이용한 연소가스 정량화에서 농도별 수분스펙트라 확보 및 적용연구)

  • Lee, Cheul-Kyu;Lee, Duck-Hee;Jung, Woo-Sung;Park, Ji-Young;Jung, Jong-Hak
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.2213-2217
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    • 2008
  • The important factor is keeping the temperature condition in quantifying several toxic components in combustion gases. In case of not keeping the temperature as it was in combustion, the change of component and concentration of smoke gases was inevitable. To solve this problem, FT-IR spectroscopy with gas cell was applied. But, there is also a difficulty in quantitative analysis of specific toxic component because of water vapor. Thus, in this study, water vapor FT-IR spectra with different concentrations were obtained and applied them to quantitative analysis.

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A Study on Thermal Comfort of Korea Men감s Wear in Summer - Based on Indoor Environment conditions - (하계 남성복의 온열쾌적감에 관한 연구 - 실내 환경조건을 중심으로 -)

  • 정상열;고경태
    • Proceedings of the Korean Fiber Society Conference
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    • 1997.10a
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    • pp.364-368
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    • 1997
  • The purpose of this Study was to determine thermal sensation and physiological responses for men in summer indoor environment, under various air temperature and relative humidity, with male university students. Subjective Evaluation, Heart Rate Variability(HRV), Electroencephalogram(EEG) were examined. We found that comfort of people was achieved at 50% R.H., 24C, and the difference of skin temperature was found at the calf area as air temperature changes. At low air temperature and low humidity, heart rate was decreased, but there was no change at brain wave, keeping a-wave.

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Effect of Feet Cooling and Feet Warming on the Behavioral Temperature Regulation (족부의 냉각과 가온이 행동성 체온조절에 미치는 영향)

  • Jeong, Woon-Seon
    • The Korean Journal of Community Living Science
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    • v.18 no.4
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    • pp.681-686
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    • 2007
  • This study was conducted to investigate the effects of the thermally different states of human feet on temperature regulation in winter season. Five healthy female students of age 20 volunteered as subjects to participate in the study. Physiological responses such as rectal temperature and skin temperatures as well as subjective responses of thermal comfort and thermal sensation were observed. Preferred clothing and preferred temperature were also evaluated in terms of behavioral temperature regulation. The results obtained through the experiment were statistically analyzed using paired t test. Rectal temperature was decreased greater (p<.01) and mean skin temperature was maintained higher (p<.01) in feet wanning than in feet cooling. Results of preferred clothing were coincident with those of general thermal sensation. There was a higher tendency to prefer temperature in feet wanning than feet cooling in the morning. It was concluded that keeping feet skin temperature lower in the early morning and higher in the late evening would be effective in terms of regulating circadian rhythm of core temperature.

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An Experimental Study on the Effect of Temperature and Humidity on the Pressure Change of the Bootstrap type Reservoir in the Aircraft (자체여압 형 항공기용 저장조의 온도 및 습도에 따른 내부압력 변화에 관한 실험적 연구)

  • Kim, Jung-Sik;Yu, Han-Sik;Park, Dong-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.5
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    • pp.170-175
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    • 2013
  • For this study, the domestically developed bootstrap reservoir of the aircraft is set up in accordance with the temperature and humidity conditions depicted on the qualification test, and the variation in the internal pressure of the bootstrap reservoir of the aircraft is examined. The study shows that the bootstrap reservoir has less variation in the internal pressure at room temperature than at low temperature($-40^{\circ}C$). As a result, the internal pressure can be maintained stably when the temperature of working fluid in the bootstrap reservoir and the atmosphere environment is over room temperature($25^{\circ}C$). Therefore the keeping of temperature above room temperature is very important to operate the bootstrap reservoir of the aircraft properly.