• 한국환경보건학회지
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• 제15권2호
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• pp.97-106
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• 1989

This experiment was performed to study the acute toxic effects of mereuric chloride(HgCl$_{2}$) in goldfish (Carassius aurams). In the study, Lc$_{50}$ values were determined for each 24, 48, 72 ,and 96-hr and mercury bioassay during the tests were performed. in five parts gill, kidney, liver, muscle and egg. The results isummarized were as follows 1. In the range of acute lethal toxicity for goldfish was 0.15-1.50 mg/l and the Lc$_{50}$ values decreased with exposure time. 2. The Lc$_{50}$ values of HgCl$_{2}$ for goldfish at 24, 48, 72 and 96 hour were 0.64, 0.53, 0.46, and 0.39 mg/l, respectively. 3. In the 400 $\mu$g/l treatment group, the average levels of mercury residues in the gill, kidey, liver, muscle and egg during 96 hour were 107.02 $\mu$g/g, 8.65 $\mu$g/g, 6.87 $\mu$g/g, 0.61 $\mu$g/g, and 0.82 $\mu$g/g, respectively. 4. The mercuny residues of gill was up to 12-175 times greater than mercury contents found in the other tissues.

• 한국어병학회지
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• 제23권1호
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• pp.119-122
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• 2010

Mortality and gill lesions in snakehead, Channa argus (body length range, 20.3-22.2 cm) reared in a aqua-farm in Busan, Korea, were associated with a dense bloom of Apiosoma-like ciliate, Order Petrichida. The size of parasite was $48.83{\pm}7.75{\mu}m{\times}14.29{\pm}2.66{\mu}m$. Histological examination revealed that a severe edema and collapse of the gill tissue were observed in a number of samples of snakehead. The mechanism of gill damage was likely due to physical irritation by the parasite. It is believed that this is the first report of Apiosoma-like ciliate in cultured fish in Korea.

• Ocean Systems Engineering
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• 제4권3호
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• pp.243-261
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• 2014

Aqua is an underwater biomimetic vehicle designed and built at McGill University that uses six paddles to produce control and propulsion forces. It has the particularity of having time-periodic thrust due to its oscillating paddles. Using an existing model of the vehicle, two types of controller were developed: a PD controller and a Floquet controller. The Floquet controller has the advantage of explicitly addressing the time-periodicity of the system. The performance of the controllers was assessed through simulation and experimentally in the Caribbean Sea. We find that the vehicle was able to follow the prescribed trajectories with relative accuracy using both controllers, though, the Floquet controller slightly outperforms the PD controller. Furthermore, a key advantage of the Floquet controller is that it requires no tuning while the PD controller had to be tuned by trial and error.

• 한국세라믹학회지
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• 제40권7호
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• pp.625-631
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• 2003

Recent work at USC has focused on strategies to enhance the toughness and overall mechanical performance of polymer foams for use in lightweight sandwich structures. Both mechanical and chemical approaches have been employed with reasonable success. Fiber reinforcement, though difficult from a processing perspective, can lead to substantial enhancements in toughness and strength, while reducing friability. Chemical modifications are also challenging from a processing perspective, but can produce similar enhancements in performance. Efforts to enhance performance of phenolic foam and PVC foam through fiber reinforcement and chemical modification are described, along with the resulting enhancements in performance.

• 한국수산과학회지
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• 제9권4호
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• pp.265-271
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• 1976

1. Formalin $50\~60ppm$, malachite green 0.2ppm, dipterex 0.6ppm 되도록 혼합하여 순환수조내의 어류기생성원충류인 Chilodonella, Costia, Trichodine, Ichthyophthirius등을 근절할 수 있었으며 이때 어체의 아가미 조직에 변화는 관찰되지 않았다. 이때에 기생충은 6기간 후부터 구제되었다. $2.130\~140ppm$ formalin에 $24\~48$시간 약욕시킨 잉어의 아가미 상피에 병리학적 변성을 볼 수 있었다. 이 경우 치료약에 장시간 약욕시킴으로서 새엽상피가 변성 괴사되고 새엽지주세포가 떨어졌다.

• 한국어병학회지
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• 제18권1호
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• pp.1-18
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• 2005

This study was performed to investigate the myxosporidian parasites from several organs of freshwater fishes caught from Dongjin River, Jeonbuk Province of Korea. Twelve myxosporidian species were dectected from five fish species out of sixteen fish species. From the gall bladder of Opsariichthys uncirostris amurensis, Zschokkella opiocephali was found; from the skin, gall bladder, liver and spleen of Pseudobagrus fulvidraco, Zschokkella opiocephali and Myxobolus cheisini were found; from the gill, skin, gall bladder and kidney of Carassius carassius, Zschokkella ctenopharyngodonis, Chloromyxum koi, Sphaerospora sinensis, Myxosoma abbottinae, Myxobolus koi and Myxobolus suturalis were found; from the kindney of Misgumus anguillicaudatus, Myxidium lieberkuhni, Neomyxobolus ophicephali and Telohanellus misgurni were found; from the gill of Cyprinus carpio, Myxosoma abbottinae and Myxobolus dispar were found. All these parasitized fishes didn't show any specific symptom.

• 수산해양기술연구
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• 제34권2호
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• pp.159-164
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• 1998

In order to investigate the relation between the environmental factors influencing on the fluctuation of fishing condition and the catch of anchovy in gill nets in the coastal waters of Yosu, five oceanographic factors, i.e., water temperature, salinity, chlorophyll-a and the catch of anchovy in gill nets are observed from June 6 to August 12 in 1993. The results obtained are summerized as follows: 1) The water temperature ranged from 16.$0^{\circ}C$ to 22.6$^{\circ}C$ and the salinity from 30.13$\textperthousand$ to 33.65$\textperthousand$. the water temperature and salinity showed no significant influence on the catch of anchovy, but the catch did not expose high values in low temperature and salinity. 2) The catch of anchovy increased with the amount of chlorophyll-a. It is therefore emphasized that the amount of chlorophyll-a is the greatest one of environmental factors influencing on the catch of anchovy.

• 국제초고층학회논문집
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• 제4권2호
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• pp.109-116
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• 2015

The concept of vertical living has been hailed as a solution to control fast growth and urbanization of cities worldwide. As super tall residential projects become more common and sustainability considerations become more necessary, their efficiency has been called into question. How do vertical residential developments compare with suburban homes? What are the environmental advantages and disadvantages of vertical communities? Is there a middle ground? We present the results from an AS+GG study that compares the environmental performance of different housing typologies ranging from a 215 supertall building to single family residences, including several scales in between. Our samples comprise 2,000 residential units per type and include the infrastructure needed to support them. We analyzed land use, energy use, and lifecycle carbon emissions for each typology. The results show that different typologies perform better depending on the parameter being assessed. We discuss these findings; assess overall performance, and present conclusions.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2000년도 학술발표회 발표논문집
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• pp.466-470
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• 2000

Recently, the calculation of horizontal bearing capacity of piles foundation has been considered very important for earthquake or wind resistant design in Korea. This study deals with the lateral resistance of PHC pile instead of vertical capacity for earthquake resistant design as well as wind. As case study, the prediction values were compared with measured ones based on ASTM. During this research, Matlock & Reese, Davisson & Gill, Broms and Chang's methods were selected in calculating prediction of lateral resistance of PHC piles. In decomposed granite and clayey soils, The result showed that prediction values proposed by Matlock & Reese(Davisson & Gill), Chang and Broms were smaller values than real values. four proposed methods by Matlock & Reese(Davisson & Gill) and Chang based on lateral deflection and Broms by ultimate lateral resistance turned out valid in view of engineering practice.

• Environmental Engineering Research
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• 제23권3호
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• pp.229-241
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• 2018

Microalgae are likely to become a part of our everyday diet in the near future as they are considered to be rich in proteins, carbohydrates, and high density lipoproteins. They will play a pivotal role in the food cycle of many people around the globe. Use of microalgae in treating wastewater is also one of the disciplines which are luring researchers as this contributes to a sustainable way of exploiting resources while keeping the environment safe. In addition, microalgal biomass also has the potential to be used as a feedstock for producing biofuel, bio fertilizers, pharmaceuticals, nutraceuticals and other bio-based products. This review presents the different value-added products obtained from microalgal biomass and the applicability of these products commercially.