• Journal of the korean society of oceanography
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• 제32권1호
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• pp.28-37
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• 1997

Two marine bivalve shells were collected from the eastern and western coastal regions of Korea, respectively. Stable oxygen and carbon isotope profiles are constructed using the incremental sampling along the axis of maximum growth to provide the continuous ${\delta}^{18}$O and ${\delta}^{13}$C records, which register the physical, biological and chemical properties of seawater where the organisms live. Cycles in the ${\delta}^{18}$O profiles are interpreted as annual along with the identification of annual growth bands; the maximum ${\delta}^{18}$O values correspond with the coldest temperature of seawater whereas the minimum ${\delta}^{18}$O values with the warmest temperature. The primary control on the amplitude of the ${\delta}^{18}$O profiles is seasonal variation of seawater temperature. The offset of the baseline between ${\delta}^{18}$O values of the two specimens is attributed to differences in both temperature and seawater ${\delta}^{18}$O values between two localities. The ${\delta}^{13}$C profiles show the similar seasonality of carbon cycling associated with phytoplankton productivity. The offset in the ${\delta}^{13}$C profiles between two specimens may be, as in the case of oxygen isotope profile, attributed to the different ${\delta}^{13}$C value of the seawater DIC (dissolved inorganic carbon) between the western coast and the eastern coast. Relationships between the shell isotopic composition and the coastal water properties of shell growth are readily interpreted from the ${\delta}^{18}$O-${\delta}^{13}$C pair diagram of the shell isotope data, similar to the use of salinity-${\delta}^{18}$O diagram for identifying water masses. The preliminary stable isotope results of this study suggest that mollusk shell isotope geochemistry may be useful to monitor the properties of water masses in the coastal and inner shelf setting around Korea and improve the interpretation of paleoceanography, provided the fossil mollusks are well preserved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1193-1194
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• 2015

The volume electrical resistivity of $3.777{\times}10^{13}{\Omega}{\cdot}cm$ of dried CSPE for 660~750 days after seawater & freshwater soaking is lower than $4.011{\times}10^{13}{\Omega}{\cdot}cm$ of that before seawater soaking. The peak binding energy of oxygen and sulphur of CSPE after seawater & freshwater soaking are shifted above 1.0ev. The grass transition temperature($T_g$) of $-19.76^{\circ}C$ of seawater & freshwater soaked CSPE are lower than $-19.59^{\circ}C$ of that of non-soaked CSPE. The melting temperatures($T_m$) of seawater & freshwater soaked and non-soaked CSPE are $45.58^{\circ}C$ and $45.59^{\circ}C$, respectively.

• 동력기계공학회지
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• 제20권5호
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• pp.92-97
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• 2016

In this study, the seawater Heat Pump System using seawater with temperature of annual domestic conditions ($0^{\circ}C$ to $25^{\circ}C$) is designed in order to compare its performance against the Heat Pump using unused heat of seawater. As a potential replacement for current refrigerants that exacerbate global warming and ozone delpetion, a Low GWP refrigerant's performance is analyzed. The basic water to water Heat Pump system is chosen and three commercial refrigerants - R134a, R410a, R32 - are used to compare against new Low GWP refrigerant R1234ze. When seawater with temperature of $25^{\circ}C$ is used, the performance change showed maximal increase in COP, 38.3%. low GWP refrigerant R1234ze, showed great performance characteristics reach to 5.242 and Existing commercial refrigerant, R134a showed only less than 0.03 performance difference against R1234ze. The study confirms notable performance of R1234ze refrigerant through simulation as environmentally friendly refrigerant for domestic seawater Heat Pump.

• 한국해양학회지:바다
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• 제19권2호
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• pp.164-168
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• 2014

거머리말 종자의 적절한 저장 방법과 저장 가능한 기간을 알아보기 위하여 우리나라 남해안에서 채취한 거머리말 종자를 이용하여 다양한 저장 방법과 저장 기간 후 발아율을 조사하였다. 거머리말 종자의 저장 방법은 공기가 공급되는 실온의 해수, $4^{\circ}C$의 해수, $30^{\circ}C$의 해수, 해수가 공급되는 수조, 밀폐된 해수, 냉동, 건조의 방법으로 저장하였다. $4^{\circ}C$의 해수에 저장한 거머리말 종자의 발아율이 가장 높았으며(52.0%), 해수가 유입되는 수조와 실온에서 저장한 종자의 발아율은 각각 17.7%와 27.4%가 나타난 반면, 건조, 냉동한 종자와 $30^{\circ}C$의 해수에 보관한 종자는 전혀 발아하지 않았다. 거머리말 종자의 각 저장 기간은 10, 20, 30, 60, 180일과 240일 동안 저장하였다. 10~60일 동안 저장한 거머리말 종자는 46.4~52.4%의 발아율을 유지하였으나, 저장 기간이 길어질수록 급격히 발아율이 감소하여, 240일 저장한 거머리말은 전혀 발아되지 않았다.

• KIEAE Journal
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• 제16권3호
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• pp.25-34
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• 2016

Purpose: The temperature in Seoul has risen 3 times more than the average global temperature increase for the past 100 years. Today, summer starts 15 days earlier than the early 20th century and is 32 days longer. This tendency causes rapid increase of cooling energy demand. Following this effect, seawater heat resources are to be used as an countermeasure for global warming. Incheon Port near the Western Sea has the lowest water temperature in the winter in South Korea in which it is suitable to use seawater cold heat resources. Method: The cold heat resource is gained from seawater when the water temperature is the lowest in the winter time and saved in a seasonal thermal storage. This can be used as cold heat resource in the summer time. A heat exchanger is essential to gain seawater cold energy. Due to this necessity, sea water heat resource heat exchangers are modeled by heat transfer equations and the fluid characteristics are analyzed. Also, a CFD (computational fluid dynamics) program is used to conduct simulation on the fluid characteristics of heat exchangers. The analyzed data of deducted from this process are comprehensively analyzed and discussed. Result: Regarding the performance of the heat exchanger, the heat exchanger was operated following the prediction within the range of heat transfer rate of minimum 3.3KW to maximum 33.6KW per device. In the temperature change analysis of the heat exchanger, fluid analysis by heat transfer equations almost corresponded to the temperature change by CFD simulation. Therefore, it is considered that the results of this study can be used as design data of heat exchangers.

• 한국환경과학회지
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• 제21권9호
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• pp.1079-1085
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• 2012

Ground seawater quality was investigated, and the algal growth potential (AGP) tests were performed along the Tongyeong coast to examine the inflow of materials, which is needed for the red tide species Cochlodinium polykrikoides to grow. The study was conducted to determine the mechanism for C. polykrikoidesred tides. Water temperature, salinity, pH, and dissolved oxygen (DO) ranged from 16.05 to $20.74^{\circ}C$, 18.20 to 32.11 psu, 6.00 to 7.61, and 3.41 to 7.91 mg/L (41.4-96.1%), respectively. No seasonal variation was observed in water temperature. The salinity, pH, and DO saturations at most stations were lower than those of coastal seawater at Tongyeong. The ${NH_4}^+$-N, ${NO_{2+3}}^-$-N, ${PO_4}^{3-}$-P concentrations ranged from 0.43 to 16.00 ${\mu}M$, 1.50 to 132.38 ${\mu}M$, and 1.30 to 6.29 ${\mu}M$, respectively; the values at some stations were much higher than observed in Tongyeong coast seawater. Using seawater from station B, C. polykrikoides grew consistently, with a high growth rate, similar to the red tide in nature. This seawater appeared to contain materials needed by C. polykrikoides to grow. Therefore, C. polykrikoides red tides seem to occur wherever the ground sea water contains materials that are needed for its growth.

• 한국발생생물학회지:발생과생식
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• 제13권1호
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• pp.35-41
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• 2009

겨울철 사육조건이 양식산 뱀장어 Anguilla japonica의 인위적인 성성숙 유도 및 번식에 미치는 영향을 조사하였다. 봄철 salmon pituitary extracts(SPE)을 이용하여 성성숙 유도 예정인 양식산 암컷 뱀장어 친어를 8주의 겨울철 사육기간 동안, 4개의 사육환경(해수저온, $10^{\circ}C$; 해수고온, $20^{\circ}C$; 담수저온, $10^{\circ}C$; 담수고온, $20^{\circ}C$)에 각각 순치하여 사육하였다. 그 후 각각의 실험구의 뱀장어를 해수 $20^{\circ}C$로 이동하여 SPE를 매주 1회 8주 동안 복강 주사하였다. 그 결과, 생식소증량지수(GSI)와 성호르몬(E2)의 농도가 해수 실험구에서 유의적으로 증가하였으며, 특히 해수저온 실험구에서 가장 높은 값을 나타냈었다. 번식률 또한 해수저온 실험구에서 가장 높게 나타났다. 이러한 결과는 겨울철 사육환경이 봄철의 성성숙 유도에 효과적인 것으로 추측되며, 양식산 뱀장어의 성성숙 유도와 부화율 향상을 위한 기초자료로 유용할 것으로 사료된다.

• 한국환경과학회지
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• 제19권11호
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• pp.1397-1405
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• 2010

Mass mortalities of cultivated organisms have occurred frequently in Korean coastal waters causing enormous losses to cultivating industry. The preventive measures require continuous observation of farm environment and real-time provision of data. However, line hanging aquaculture farm are generally located far from monitoring buoys and has limitations on installation of heavy equipments. Substituting battery pack for solar panels and miniaturizing size of buoy, newly developed system can be attached to long line hanging aquaculture farm. This system could deliver measured data to users in real-time and contribute to damage mitigation and prevention from mass mortalities as well as finding their causes. The system was installed off Gijang and Yeongdeck in Korea, measuring and transmitting seawater temperature at the sea surface every 30 minutes. Short term variation of seawater temperature, less than one day, in Gijang from June to July 2009 corresponded tidal period of about 12 hours and long term variation seemed to be caused by cold water southeast coast of Korea, particularly northeast of Gijang. Seawater temperature differences between Gijang station and the other station that is about 500 m away from Gijang station were $1^{\circ}C$ on average. This fact indicates that it is need to be pay attention to use substitute data even if it is close to the station. Daily range of seawater temperature, one of crucial information to aquaculture, can be obtained from this system because temperature were measured every 30 minutes. Averages of daily range of temperature off Gijang and Yeongdeok during each observation periods were about $2.9^{\circ}C$ and $4.7^{\circ}C$ respectively. Dominant period of seawater temperature variation off Yeongdeok was one day with the lowest peak at 5 a.m. and the highest one at 5 p.m. generally, resulting from solar radiation.

• Ocean and Polar Research
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• 제30권3호
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• pp.249-258
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• 2008

이석(otoliths)은 경골 어류의 내이(inner ear)에 존재하는 평형석으로 어류의 성장과 함께 성장하며, 이석 내 산소동위원소는 어류가 서식했던 수온에 영향을 받으며 침전되기 때문에 어류가 서식했던 서식처의 수온을 반영한다고 알려져 있다. 본 연구에서는 명태 이석 내 산소동위원소(${\delta}^{18}O$)와 서식 수온과의 관계를 조사하여, 명태의 생활사에 따른 서식지의 변동을 비교하였다. 우리나라와 일본의 동쪽 해역에서 $1997{\sim}1999$년 사이에 채집된 명태로부터 이석을 채취하여 연령대 별로 산소동위원소 함량을 분석하였으며, 수온 자료는 양국의 해양자료센터(KODC, JODC)로부터 획득하였다. 명태가 서식하는 수심의 수온은 가을과 겨울에 걸쳐 연중 가장 높았고, 우리나라 동해연안은 200 m 이상의 수심에서는 계절적 변동이 거의 없이 낮은 수온이 분포하는 안정된 상태였으나, 일본 해역에서는 300 m의 비교적 깊은 수심에서도 계절적 변화를 보였다. 전반적으로 모든 수심에서 우리나라 보다 일본 연안의 수온이 높았으며, 일본 해역의 명태가 우리나라 명태보다 깊은 곳에 서식하였다. 우리나라와 일본 명태 이석의 산소동위원소 값은 대부분 시료에서 이석의 핵 부분 보다는 가장자리 부분에서 산소동위원소 값이 높아 명태가 성장하면서 수온이 낮은 깊은 수심으로 이동하는 것으로 이해된다. 또한, 3년 동안의 수온변화와 그 당시 성장하였던 이석의 산소동위원소 값은 역상관 관계를 보이고 있다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 INTERNATIONAL SYMPOSIUM ON SOIL & GROUNDWATER ENVIRONMENT
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• pp.158-159
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• 2005

This study showed that the highest temperature point of the Dongrae thermal spring in Pusan was moved to the north direction of the Dongrae fault as times goes by. The Br concentration(1.5mg/L) in Dongrae thermal waters indicated the influence of 2% seawater mixing. If the simple mixing without hydrochemical reaction occurs between seawater and thermal water, the concentration of Mg will be about 20mg/L. But the low concentration(0.1 mg/L) of Mg, contrary to high concentration(10 mg/L) of surrounding groundwater not affected by thermal water, suggested the thermal water, seawater and rock interactions. The calculation of saturation index(SI) by using the geochemical code of EQ3NR showed that the Mg in thermal groundwater, which was introduced by seawater, was removed by the precipitation of Antigorite (SI: log Q/K =71.753, $Mg_{48}Si_{24}O_{85}(OH)_{62}$) and Tremolite (SI: 8.463, $Ca_2Mg_5Si_8O_{22}(OH)_2$), Talc (SI: 6.409, $Mg_3Si_4O_{10}(OH)_2$), Dolomite (SI: 2.014, $CaMg(CO_3)_2$), Chrysotile (SI: 3.698, $Mg_3Si_2O_5(OH)_4$) in the crack of fault zone. The highest temperature point in the study area will move to north direction and stop in the Jangjun area without the input of seawater.