• Title/Summary/Keyword: Water temperatures

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Phase Behavior of Sorbitan Monopalmitate Surfactant in Supercritical Carbon Dioxide (초임계 이산화탄소에서 소르비탄 모노팔미테이트 계면활성제의 상거동에 관한 연구)

  • Oh, Kyung Hwan;Kim, Eun Jin;Shin, Hun Yong
    • Clean Technology
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    • v.19 no.1
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    • pp.8-12
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    • 2013
  • Phase behavior of carbon dioxide + surfactant binary system and carbon dioxide + surfactant + water ternary system was investigated at the temperatures from 318 K to 348 K by using high pressure vapor liquid equilibrium apparatus containing variable-volume view cell. Sorbitan monopalmitate was used as the surfactant. The cloud point pressures for the binary mixture of carbon dioxide + sorbitan monopalmitate increased with an increasing of system temperatures and the maximum cloud point pressure was observed at the composition of 0.226 wt% of sorbitan monopalmitate. On the other hand, as the temperatures and compositions of water increased, the cloud point pressures for ternary system containing 0.1 wt% of sorbitan monopalmitate increased significantly. For the ternary system of constant 0.2 wt% of water, the cloud point pressure curves show relatively flat according to the change of compositions of surfactant. The cloud point pressures increased when the temperatures and compositions of water increased.

Numerical Analysis of Natural Convection from a Horizontal Surface Immersed in Cold Water (저온의 물속에 잠겨있는 수평 평면에 의하여 야기되는 자연대류의 수치해석)

  • 유갑종;예용택;권혁용
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.6
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    • pp.1195-1204
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    • 1992
  • The natural convection from upward and downward facing horizontal isothermal plate immersed in water is studied numerically. The temperature of the plate is from 0.0 .deg. C to 8.0 .deg. C and the ambient water temperature is from 1.0 .deg. C to 10.0 .deg. C. Numerical results are presented for the velocity profiles, temperature profiles, local heat transfer coefficients, and average Nusselt numbers over the entire flow fields. Flow patterns are shown in the upward and downward facing surfaces at different ambient water temperatures. For the upward facing surface, there are upflow and unsteady flow. And the regions of the ambient water temperatures which give rise to the upflow are more extensive as the temperatures of the isothermal surface become more distant from the density extremum temperature. For the downward facing surface, only the downflow region is shown. For the upward facing horizontal isothermal surface, the average Nusselt number(= N $u_{1}$$^{*}$) is 28.86(Ra)$^{0.01}$. And for the downward facing surface, the average Nusselt number(= N $u_{2}$$^{*}$) is $C_{2}$(Ra)$^{0.2}$ and the values of $C_{2}$ are enlarged in the range of 0.785 .leq. $C_{2}$ .leq. 1.250 as increasing of the temperatures of the isothermal surface.ace.ace.

A Review of the Optimum Feeding Rates and Feeding Frequency in Korean Rockfish Sebastes schlegeli Reared at Seven Different Water Temperatures

  • Mizanur, Rahman M.;Bai, Sungchul C.
    • Fisheries and Aquatic Sciences
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    • v.17 no.2
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    • pp.229-247
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    • 2014
  • Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish Sebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at $17^{\circ}C$ and $20^{\circ}C$; three feeding rate experiments for 16-g Korean rockfish at $16^{\circ}C$ and $24^{\circ}C$; and finally, two feeding frequency experiments for 93- and 100-g at $15^{\circ}C$ and $20^{\circ}C$ were conducted. Twenty fish averaging $5.5{\pm}0.2$ g ($mean{\pm}SD$) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of $17^{\circ}C$ and $20^{\circ}C$. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of $15^{\circ}C$ and $19^{\circ}C$. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at $17^{\circ}C$ and 4.83% (BW/day) at $20^{\circ}C$. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at $16^{\circ}C$, 3.75% (BW/day) at $20^{\circ}C$, and 3.34% (BW/day) at $24^{\circ}C$. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of $15^{\circ}C$, and 100 to 132 g at $19^{\circ}C$.

Growth and Body Composition of Mandarin Fish Siniperca scherzeri Reared at High Water Temperatures (고수온(27-33℃)에서 사육한 쏘가리(Siniperca scherzeri) 치어의 성장 및 체조성 변화)

  • Kim, Yi-Oh;Lee, Sang-Min
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.6
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    • pp.756-761
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    • 2017
  • This study investigated the growth of juvenile mandarin fish Siniperca scherzeri, reared at high water temperatures. Feed-trained juvenile fish were reared at four water temperatures: 27, 29, 31, and $33^{\circ}C$. The fish were fed to apparent satiation twice daily using pelleted diet. After 10 weeks of feeding trial, the survival exceeded 98% in all groups. The weight gain of fish reared at $31^{\circ}C$ was higher than for fish reared at the other temperatures. The feed efficiency and protein efficiency ratio of fish reared at 29 and $31^{\circ}C$ were higher than for the fish reared at 27 and $33^{\circ}C$. The daily feed intake of fish reared at 27 and $33^{\circ}C$ was higher than for the 29 and $31^{\circ}C$ groups. The whole body moisture content of fish reared at $33^{\circ}C$ was higher than in the $27^{\circ}C$ group. The whole body crude protein and lipid contents of fish reared at $27^{\circ}C$ were higher than in the $33^{\circ}C$ group. The results indicate that suitable rearing water temperature was $31^{\circ}C$ for optimal growth and feed efficiency of juvenile mandarin fish under the experimental conditions.

Hot-water soluble on Waxy Black Rice and Waxy Rice Flours (찰흑미와 일반찰벼의 열수가용성 물질)

  • Oh, Geum-Soon;Kim, Kwan;Choi, Gyeong-Cheol;Na, Hwan-Sik;Kang, Gil-Jin;Kim, Sung-Kon
    • Korean Journal of Food Science and Technology
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    • v.34 no.2
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    • pp.343-345
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    • 2002
  • The study was investigated hot-water soluble on waxy black and waxy rice flours according to gelatinization temperatures and heating time. The hot-water soluble contents of both samples were increased during heating time at $90^{\circ}C$. The waxy black and waxy rice flours solutions according to gelatinization temperatures ($80^{\circ}C,\;90^{\circ}C,\;95^{\circ}C\;and\;98^{\circ}C$) were heated for 10, 20 and 30 min. Determination of elution patterns of rice flours was used by Sepharose CL-2B column. As a result, the elution patterns were eluted the most in void volume ($V_0$) and the elution patterns of the hot-water solubles were increased according to heating time and gelatinization temperatures.

Water-Temperature Prediction of Streams Entering into Imha Reservoir using Multi-Regnssion Method (다중회귀분석을 이용한 임하호 유입하천의 수온예측)

  • Yi, Yong-Kon;Lee, Sanguk;Koh, Deuk Koo
    • Journal of Korean Society on Water Environment
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    • v.22 no.5
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    • pp.919-925
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    • 2006
  • The regression models for the water temperatures of Ban Byeon Stream and Yong Jeon stream were developed using multi-regression method. It was also investigated that the applicability of the stream temperature prediction to two-dimensional numerical simulation to predict the vertical water temperature in Imha Reservoir. Air temperature and dew point as independent variables were selected to be applicable to cases with the different variation of flow rates. The data division of water temperature using a cutoff flow rate of $20m^3/s$ was found to reduce the prediction error of the stream temperature. The mean absolute percent error of the numerical simulation results of the vertical water temperature in Imha Reservoir using the regression models was 11%, which was only 4.3% lager than the simulation result using the measured stream temperature. Therefore, the regression models of the stream temperatures using multi-regression method applied in this study could be applied to predict the vertical water temperature in Imha Reservoir with a good accuracy.

Water Supply Reliability Revaluation For Agricultural Water Supply Pattern Changes Considering Climate Changes (기후변화에 따른 농업용수공급패턴의 변화로 인한 이수안전도변화분석)

  • Choi, Young-Don;Ahn, Jong-Seo;Shin, Hyun-Suk;Cha, Hyung-Sun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2010.05a
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    • pp.273-277
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    • 2010
  • This research was performed to examine changes in the timing of the growth of crops along with changes in temperatures due tochanges and to analyze the change of water-supply-reliability by adding an analysis of the change of agricultural water supply patterns in the basin area of Miryang dam in Korea. Had-CM3 model from U.K. was the tool adopted for the GCM model, a stochastic, daily-meteorology-generation-model called LARS-WG was alsoused for downscaling and for the climate change scenario (A1B) which represents Korea's circumstances best. First of all, to calculate changes in the timing of the growth of crops during this period, the theory of GDD was applied. Except for the period of transplanting and irrigation, there was no choice but to find the proper accumulated temperature by comparing actual temperature data and the supply pattern of agricultural use due to limited temperature data. As a result, proper temperatures were found for each period. $400^{\circ}C$ for the preparation period of a nursery bed, $704^{\circ}C$ for a nursery bed's period, $1,295^{\circ}C$ for the rice-transplanting period, $1,744^{\circ}C$ for starting irrigation, and $3,972^{\circ}C$ for finishing irrigation. To analyze future agricultural supply patter changes, the A1B scenario of Had-CM3 model was adopted, and then Downscaling was conducted adopting LARS-WG. To conduct a stochastical analysis of LARS-WG, climate scenarios were generated for the periods 2011~2030, 2046~2065, 2080~2099 using the data of precipitation andMax/Min temperatures collected from the Miryang gauging station. Upon reviewing the result of the analysis of accumulated temperatures from 2011~2030, the supply of agricultural water was 10 days earlier, and in the next periods-2046~2065, 2080~2099 it also was 10 days earlier. With these results, it is assumed that the supply of agricultural water should be about 1 month ahead of the existing schedule to meet the proper growth conditions of crops. From the results of the agricultural water supply patterns should be altered, but the reliability of water supply becomes more favorable, which is caused from the high precipitation change. Furthermore, since the unique characteristics of precipitation in Korea, which has high precipitation in the summer, water-supply-reliability has a pattern that the precipitation in September could significantly affect the chances of drought the following winter and spring. It could be more risky to make changes to the constant supply pattern under these conditions due to the high uncertainty of future precipitation. Although, several researches have been conducted concerning climate changes, in the field of water-industry, those researches have been solely dependent on precipitation. Even so, with the high uncertainty of precipitation, it is difficult for it to be reflected in government policy. Therefore, research in the field of water-supply-patterns or evapotranspiration according to the temperature or other diverse effects, which has higher reliability on anticipation, could obtain more reliable results in the future and that could result in water-resource maintenance to be safer and a more advantageous environment.

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Effect of Water Temperatures and Photoperiods on Gondal Development in Banded Catfish Pseudobagrus fulvidraco (동자개(Pseudobagrus fulvidraco)의 생식소 발달에 수온과 광주기가 미치는 영향에 관한 연구)

  • Lim, Sang-Gu;Han, Chang-Hee
    • Journal of Fisheries and Marine Sciences Education
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    • v.24 no.6
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    • pp.854-861
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    • 2012
  • To investigate the role of water temperatures and photoperidos as environmental cues regulating reproductive rhythm in banded catfish Pseudobagrus fulvidraco, rearing experiments were conducted using sveral rearing regimes conbined with changes in photoperiods and water temperatures during growing and spawning periods. GSI of $23^{\circ}C$ was significantly higher than $18^{\circ}C$ in female, but 9 light of 18 and $23^{\circ}C$ were no difference in male. In case of estradiol, $18^{\circ}C$ and 15 L was higher than other experintal precinct after 20 days. But, end of the experiment, all of experimental precinct were no difference. Testosteron of female was no difference in $18^{\circ}C$-9 and 15 L after 20 days. Testosteron of male was no difference in $18^{\circ}C$-9 L. In case of 11-KT, control level was $0.39{\pm}0.03$ ng/mL and $18^{\circ}C$-9 L was no significantly difference after 20 days. But, 15 L was higher than other experimental precinct.

Barix Thin Film Encapsulation of OLED's on Flexible and Rigid Glass substrates; high temperature performance and manufacturing aspects.

  • Chu, X.;Moro, L.;Rutherford, N.;Visser, R.J.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1699-1702
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    • 2007
  • We will discuss encapsulation of OLEDs on both flexible and rigid glass substrates. Accelerated testing at 6CC/90RH and 85C/85RH is compared and acceleration factors for OLED and Calcium test samples are discussed.We have tested the stability and performance of our barrier coating to much higher temperatures: up to 140 C. Water Vapor Transmission rates at temperatures from 60 to 140 C are presented. Rates and methods for low cost manufacturing on a large scale are analysed

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