• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.761-766
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• 2006

This paper describes a study on the performance of steam ejector by variation of steam pressure. Water temperature is especially important for good qualify of fish in an inland aquafam. In summer season, the water temperature increases above $25^{\circ}C$, but for good quality breeding or fish is the maintenance of optimum aquafam temperature by about $20^{\circ}C$. Therefore it is needed to drop the water temperature to provide suitable conditions of fish growth. There are many kinds of cooling system, in this study using steam ejector. After cooling the water in vacuum tank with the steam ejector then circulate this water to inland aquafam. In this way to minimizes fish stress that it is caused by water temperature. The objective of research confirms the difference of the case which there is no water in the vacuum tank and has water in the vacuum tank. The purpose of this paper is to examine the effects on the performance of steam ejector by variation of steam pressure.

• Fisheries and Aquatic Sciences
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• 제26권12호
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• pp.738-751
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• 2023

The Sembilan Archipelago is famous for its great biodiversity, in which the humphead wrasse (Cheilinus undulatus) (locally named Napoleon fish) is the primary commodity (economically important), and currently, the environmental degradation occurs due to anthropogenic activities. This study aimed to examine the eco-environmental parameters and assess their influence on the abundance of humphead wrasse and other coral reef fish compositions in the Sembilan Archipelago. Direct field monitoring was performed using a visual census throughout an approximately one km transect. Coral cover data collection and assessment were also carried out. A coastal water quality index (CWQI) was used to assess the water quality status. Furthermore, statistical-based analyses [hierarchical clustering, Pearson's correlation, principal component analysis (PCA), and canonical correspondence analysis (CCA)] were performed to examine the correlation between eco-environmental parameters. The Napoleon fish was only found at stations 1 and 2, with a density of about 3.8 Ind/ha, aligning with the dominant composition of the family Serranidae (covering more than 15% of the total community) and coinciding with the higher coral mortality and lower reef fish abundance. The coral reef conditions were generally ideal for supporting marine life, with a living coral percentage of about > 50% in all stations. Based on CWQI, the study area is categorized as good and excellent water quality. Of the 60 parameter values examined, the phytoplankton abundance, Napoleon fish, and temperature are highly correlated, with a correlation coefficient value greater than 0.7, and statistically significant (F < 0.05). Although the adaptation of reef fish to water quality parameters varies greatly, the most influential parameters in shaping their composition in the study area are living corals, nitrites, ammonia, larval abundance, and temperature.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.133-137
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• 2014

Rearing experiments were conducted using several regimes combined with different photoperiods and water temperatures to investigate the role of temperature and photoperiod as environmental cues regulating reproduction in red marbled rockfish, Sebastiscus tertius. The initial gonadosomatic index (GSI) was $1.62{\pm}0.32%$ and that in the $15^{\circ}C$ control was $7.01{\pm}0.46%$ at the end of the experiment. The highest GSI was $9.10{\pm}0.35%$ in the 12L:12D photoperiod-treated fish. The highest GSI at $19^{\circ}C$ was $15.03{\pm}0.86%$ in the 12L:12D photoperiod treatment. The initial hepatosomatic index (HSI) was $3.09{\pm}0.72%$ and that in the $15^{\circ}C$ control was $3.88{\pm}0.45%$. The highest HSI was $4.00{\pm}0.56%$ in the 15L:9D treated fish. The highest HSI at $19^{\circ}C$ was $4.05{\pm}0.63%$ in the 12L:12D treated fish.

• 한국수산과학회지
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• 제37권1호
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• pp.13-17
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• 2004

The effects of temperature on nitrification of enriched nitrifiers were investigated by using kinetics and thermodynamics method through the batch test. Aquaculture recirculating water, which was sampled at Chung Cheong Buk-Do Inland Fisheries Research Institute, was analized to observe the characteristics of nitrification. Temporal variation of ammonium, nitrite and nitrate concentration was measured at batch experiments. Activation energy was calculated using Arrhenius equation with the oxidation rates of specific ammonium or nitrite ion. These oxidation rates were measured at temperature range of $6-35^{\circ}C$ and ammonium concentration range of 0.2-1.8 mg/L. Two distinct activation energy of Nitrosomonas sp. at temperature $6-15^{\circ}C\;and\;15-35^{\circ}C$ was 93.1 and 25.0 KJ/mol, respectively. Nitrate accumulation was observed at temperature over $15^{\circ}C.$

• 한국어류학회지
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• 제23권2호
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• pp.150-157
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• 2011

칼납자루를 중심으로 납자루아과 고유종 각시붕어, 한강납줄개, 묵답자루의 재생산을 위한 기초 연구를 하였다. 난의 형태와 부화 자어는 종별로 독특하였으며 암컷의 크기와 1회 산란량의 상관관계는 뚜렷하게 나타나지 않았다. 칼납자루 $13.0^{\circ}C$에서도 산란이 가능하였으나 수정란의 부화율은 43.5%로 낮았으며, 수온 $21.0^{\circ}C$에서 79시간 만에 부화하였고 다른 비교 종들과 같이 수온이 높을수록 부화에 이르는 시간은 단축되었다. 칼납자루는 부화 후 자어 시기를 거쳐 300일 만에 52.4 mm로 성장하여 재생산에 참여할 어미가 되기에 충분하였다. 납자루아과 어류의 재생산 연구는 고유 담수어 보존 연구의 기초자료로 활용될 것이다.

• 한국지역지리학회지
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• 제19권2호
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• pp.352-361
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• 2013

기상 현상을 예측하는 수치예보모델의 주요한 기초 입력 데이터로 토지이용, 지형, 식생, 지표 온도 등이 있다. 이 중 지표 온도의 일부인 내륙 수면 온도에 대한 지상 관측 데이터는 강이나 호수의 일부 지역에만 존재한다. 따라서 본 연구는 수치예보모델의 입력 데이터인 내륙 수면 온도로 활용할 수 있는 MODIS 위성영상의 지표 온도 데이터의 오차정도를 확인하기 위해 국내 내륙 수온 지상 관측 데이터와 비교 분석하였다. 이를 위해 2011년 7월부터 2012년 6월까지 약 1년의 MODIS Land Surface Temperature(LST) 데이터와 수질자동측정망의 수온 데이터를 비교하였다. MODIS 데이터는 주간 및 야간 데이터로 구성되는 데, 각각의 월 평균 오차는 $2^{\circ}{\sim}8^{\circ}C$, $3^{\circ}{\sim}12^{\circ}C$로 주간 데이터의 오차가 작았다. 특히, 주간 데이터의 오차는 가을에 $2^{\circ}C$로 다른 계절에 비해 작았고, 야간 데이터는 여름에 $3^{\circ}C$로 다른 계절에 비해 작았다. 또한 지역적으로는 한강, 낙동강, 금강, 영산강의 4대강을 비교한 결과 가장 남쪽에 있는 영산강 유역에서 가장 오차가 작았다. 본 연구를 통해 수치예보모델의 입력 데이터로 활용함에 있어 MODIS 지표 온도 데이터의 오차 정도를 확인할 수 있었다. 연구 결과는 아시아 지역에 대해 수치예보모델을 운용할 때 북한 및 해외 지역에 대해 MODIS 지표 온도 데이터를 활용함에 있어 그 오차 정도의 기준이 될 수 있을 것이다.

• 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.

• 한국수산과학회지
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• 제49권5호
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• pp.607-611
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• 2016

This study was conducted to investigate the effects of different water temperatures on growth, survival, biochemical composition, and blood physiological parameters of juvenile mandarin fish Siniperca scherzeri. Feed-trained juvenile fish were subjected to four water temperatures (20, 23, 26 and 29℃) with two replicate groups. The fish were fed to apparent satiation twice daily using a formulated diet containing 55% crude protein and 6% crude lipid. After the 8-week feeding trial, survival was >96% in all groups. Weight gain and feed efficiency of fish reared at 26 and 29℃ were higher than those reared at 20℃. The protein efficiency ratio, daily feed intake, and whole body proximate composition were not affected by water temperature. These results indicate that a suitable water temperature range for optimal growth and feed efficiency of juvenile mandarin fish is 26-29℃ under these experimental conditions.

• Ecology and Resilient Infrastructure
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• 제6권2호
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• pp.120-127
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• 2019

본 연구에서는 광섬유 온도 분포 센싱을 통한 제체의 침투 및 붕괴와 같은 물리적 변화 현상을 모니터링하기 위해 중규모 제방 수리실험을 수행하였다. 본 실험의 중규모 실험 제방은 바이오폴리머 흙을 제방 전면에 도포하여 강도를 증진시킨 것으로 월류에 의한 침투 및 붕괴 현상이 일반 제방과는 다르게 나타날 수 있으며, 이러한 현상은 광섬유 온도 분포 센싱을 통해 획득한 온도 변화 정보를 통해 분석할 수 있었다. 제체의 위치별 시간에 따른 온도 변화 자료를 통해 제체 내부의 물리적 변화 및 침투가 발생하는 위치와 시간을 판단할 수 있었다. 본 실험에서는 급격한 온도 변화 시점이 제외지 사면보다 제내지 사면에서 먼저 발생하였으며, 이는 실험에서 제내지 사면이 붕괴된 후에 제외지 사면이 붕괴된 순서와 일치하였다.

• Journal of Ecology and Environment
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• 제41권3호
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• pp.45-53
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• 2017

Background: There have been many studies on the growth conditions of Zostera marina and Zostera japonica, but few studies have examined how spatial and temporal factors affect growth in established seagrass beds or the distribution range and shoot density. This study aims to clarify the factors that determine the temporal and spatial distribution of Zostera marina and Zostera japonica in the Seto Inland Sea east of Yamaguchi Prefecture. Methods: The study site is in Hiroshima Bay of the Seto Inland Sea, along the east coast of Yamaguchi Prefecture, Japan. We monitored by diving observation to confirm shoot density, presence or absence of both species and observed water temperature, salinity by sensor in study sites. Results: The frequency of occurrence of Zostera marina was high in all seasons, even in water depths of D.L. + 1 to -5 m ($80{\pm}34%$ to $89{\pm}19%$; mean ${\pm}$ standard deviation), but lower (as low as $43{\pm}34%$) near the breakwall, where datum level was 1 to 2 m, and it was further reduced in datum level -5 m and deeper. The frequency of occurrence of Zostera japonica was highest in water with a datum level of +1 to 0 m. However, in datum level of 0 m or deeper, it became lower as the water depth became deeper. Datum level +1 m to 0 m was an optimal water depth for both species. The frequency of occurrence and the shoot density of both species showed no negative correlation. In 2011, the daily mean water temperature was $10^{\circ}C$ or less on more days than in other years and the feeding damage by S. fuscescens in the study sites caused damage at the tips. Conclusions: We considered that the relationship between these species at the optimal water depth was not competitive, but due to differences in spatial distribution, Zostera marina and Zostera japonica do not influence each other due to temperature conditions and feeding damage and other environmental conditions. Zostera japonica required light intensity than Zostera marina, and the water depth played an important role in the distribution of both species.