• Title/Summary/Keyword: 해수 온도

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Performance analysis of a cooling system with refrigerant in a marine absorption refrigerator (선박용 흡수식 냉동기의 냉매적용 냉각 시스템 성능 분석)

  • Yun, Sang-Kook
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.4
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    • pp.282-287
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    • 2016
  • Recently in order to protect the ocean environment and to reduce energy consumption, shipbuilders have been developing highly economized ships. This research analyzed the possibility of adopting the onshore absorption refrigerator to offshore ships having a cooling system with refrigerant by using the waiste heat of the engine jacket cooling water instead of compression refrigerators. The results showed that R236fa could be a suitable medium for absorbing the heat of the absorber and condenser in an absorption refrigerator. The cooling system using R236fa achieved a high COP of 0.798, which is 15% and 5% higher than an air cooling system with a cooling tower and a water cooling system with a heat exchanger, respectively. The cooling system with R236fa achieved high efficiency with a 25% reduction in flow rate of LiBr solution and only 15.7% flow rate of cooling medium as compared to the water cooling system. The heating of sea water by the engine jacket water flowing out from the generator can prevent the crystallization of LiBr solution due to the low temperature of sea water.

A Study of Relation of Winter Climate between El-Nino.La-Nina and Sea Surface Temperature in Korea (한국의 겨울 기후 및 해수 온도에 미치는 엘리뇨와 라니냐의 영향)

  • Bak, Byeong-Su;Min, Woo-Ki
    • Journal of the Korean association of regional geographers
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    • v.5 no.2
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    • pp.143-153
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    • 1999
  • This study is analyzed the correlation between El-Nino and La-Nina and Korea's temperature and precipitation in summer and winter, and the results of this analysis are as follows: (1) The extraction of the occurrences of El-Nino reveals are 5, but La-Nina reveals 6 years. (2) The tendency of change of sea surface temperature around NINO.3 and that of or country are about the same, but the anomaly of Janggi and Pusan was much greater than that of Inchon. (3) The anomaly of sea surface temperature around NINO.3 and that of the temperature showed the similar changing tendency, the temperature of Korea has something to do with that of NINO.3sea surface temperature as the correlation of ground temperature with the temperature of sea surface showed 0.06. Anomaly warm winter has something to do with El-Nino because the temperature of our country was high when El-Nino phenomena appeared. But the precipitation over our country is not significant for La-Nina. (4) Temperature in El-Nino year is lower than normal in summer and higher than normal in winter. But precipitation is more in summer and winter of El-Nino year, but it is not significant of La-Nina year.

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Paleoceanographic Investigation from the Ostracodes of the Middle Miocene Chunbuk Formation in Pohang Basin (포항분지 중기 마이오세 천북층에서 산출되는 개형충 화석을 이용한 고해향학적 연구)

  • Woo, Kyung-Sik;Huh, Min;Park, Se-Moon
    • 한국해양학회지
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    • v.29 no.2
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    • pp.164-170
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    • 1994
  • The well preserved ostracodes of the Chunbuk Formation in Pohang Basin were analyzed isotopically to understand paleoceanographic conditions of the southeastern park of Korean peninsula which Songhacdong, and Mulcheonri areas range from - 2.2 to - 0.7% (PDB), - 0.7 to 0.0% , and -20.0 to - 0.8%, and their corresponding paleotemperatures range from ca 20 to 27$^{\circ}C$ (average = 24$^{\circ}C$), 17 to 20$^{\circ}C$ (average = 18$^{\circ}C$), and 20 to 26$^{\circ}C$ (average=23$^{\circ}C$),respectively. Assuming the $\delta$/SUP 18/O composition of the Middle Miocene seawater was about - 0.34% (SMOW), the paleotemperatures of the Middle Miocene shallow seawater in the Pohang Basin was almost equal to or slightly higher than the present summer temperature (ca 16 to 20$^{\circ}C$) near Pohang area. Carbon isotopic value of Cyhere omotenipponica is - 0.8% (PDB), reflecting marine carbonate carbon composition. Carbon isotopic compositions of other ostracodes such as Aurial okumurai, Trachyleberis niitsmai, Urocythereis sp., Urocythereis cf. gorokuensis, and Acanthocythereis mutsuensis range from - 5.2 to - 3.4% (PDB), which might have secreted their shells out of equilibrium with ambient seawater. This disequilibrium was most likely to have resulted from metabolic (=vital) effect, rather than temperature of productivity.

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Seasonal Predictability of Typhoon Activity Using an Atmospheric General Circulation Model and Observed Sea Surface Temperature Data (대기 대순환 모헝과 해수면 온도 관측 자료를 이용한 태풍 활동의 계절 예측 가능성)

  • Han, Ji-Young;Baik, Jong-Jin
    • Journal of the Korean earth science society
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    • v.27 no.6
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    • pp.653-658
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    • 2006
  • The seasonal predictability of typhoon activity over the western North Pacific is investigated using an atmospheric general circulation model GCPS. A ten-member ensemble with different initial conditions is integrated for five months using observed sea surface temperature data for each year from 1979 to 2003. It is shown that the monthly variation of occurrence frequency of simulated tropical storms and the distribution of tropical storm genesis location are similar to those of observed tropical storms, but the model is unable to reliably predict the interannual variation of the occurrence frequency of tropical storms. This is largely because the observed relationship between tropical storm occurrence frequency and ENSO is different from the simulated one. Unlike the observation, in which the tropical storm occurrence frequency has no relation to ENSO, the model has a tendency to generate more (less) tropical storms than normal during El Nino (La Nina). On the other hand, the interannual variation of the mean longitude of tropical storms that shows a close connection with ENSO in both observations and simulations is simulated similar to the observation.

Sand Elimination in Shortnecked clam, Ruditapes philippinarum, Harvested from Western Coast of Korea (서해산 바지락 (Ruditapes philippinarum)의 토사 배출 조건)

  • SONG Ki-Cheo1;MOK Jong-Soo;KANG Chang-Su;CHANG Dong-Suck
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.34 no.3
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    • pp.179-183
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    • 2001
  • Shortnecked clam, Ruditapes philippinarum, is one of the very important shellfish produced in south-western coast of Korea. But it's ready to be polluted and have sand in flesh because it mainly inhabit in silt at the inside of coastal area. This study was carried out to obtain informations about the elimination of sand in shortnecked clam harvested from western coast of Korea. During rearing shortnecked clams in water tank, the elimination rates of sand from them at 6, 13, 23, $28^{\circ}C$ were 59.0, 88.2, 97.9, $96.1^{\circ}C$ after 48 hours, respectively. The sand was eliminated above $95^{\circ}C$ from the shellfish at 32,9 to $40\%_{\circ}$ of salinity after 48 hours. But the sand elimination from them was incomplete and inconsistent at 10 to 20 of salinity. The sand was eliminated rapidly at pH 1.9 to 9.0 however, its elimination was not effective at neutral or acidity range, It was found that the sand elimination was most effective at $23^{\circ}C, 35\%_{\circ}$ salinty and pH 9.0. Reasonable flow rate for sand eliminate in shortnecked clam was above 150 L/min./shellfish $m^3$ under both 3,000 and 4,000 L/shellfish $m^3$, and above 100 L/min,/shellfish $m^3$ under both 6,000 and 8,000 L/shellfish $m^3$ in water tank.

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A Study on the NOx Reduction of Flue Gas Using Un-divided Electrolysis of Seawater (무격막식 해수 전기분해 방식을 통한 배연 탈질에 관한 연구)

  • Kim, Tae-Woo;Choi, Su-Jin;Kim, Jong-Hwa;Song, Ju-Yeong
    • Korean Chemical Engineering Research
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    • v.50 no.5
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    • pp.825-829
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    • 2012
  • In this study, we investigated NO oxidation characteristic that depends on available chlorine concentration and temperature of seawater which is treated by un-divided electrolysis. Reactant gas passed through bubbling reactors which is filled with electrolyzed water and then NO concentration change was analyzed. In the closed-loop electrolysis system, concentration of available chlorine increased with electrolysis time. The higher oxidation rate of NO to $NO_2$ was obtained with the higher concentration of available chlorine. Oxidation of NO was fast when temperature of electrolyzed water was high, in the case of same concentration of available chlorine.