• Title/Summary/Keyword: Surface Waters

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LNG-Vessels Hybrid Engine Seawater Desalination Complex System (LNG 선박 하이브리드 엔진 및 해수 담수화 복합 시스템)

  • Lim, Jae Jun;Lee, Dong-Heon;Byun, Gi-Sik;Kim, Gwan-Hyung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.663-664
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    • 2016
  • Temperature difference power generation using sea water is a method repeatedly closed liquefaction and gasification by using the ammonia (refrigerant) of the deep sea water and surface water with a temperature difference between turning the turbine. The larger the temperature difference between the nature of the temperature characteristic energy generation development, the better. This is the story that the surface waters of the deep-water temperature difference is large. But the winter is not large temperature difference between surface water and deep water has lowered energy efficiency. And desalination technologies accounted for 97% of the earth, but we can not eat the technology to convert sea water into fresh water, fresh water produced by the desalination technology that is available for various industries such as irrigation, drinking water in the vessel.In this paper, LNG transport vessels, based on the LNG transport ship to the temperature difference power generation using cold energy of thermal energy and LNG marine diesel engines, which use the existing order to improve the temperature of the surface waters of the season that is the current problem we propose that a complex development of desalination and desalination of seawater freezing research into hybrid research and utilizing the cold energy of the engine.

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Passage Planning in Coastal Waters for Maritime Autonomous Surface Ships using the D* Algorithm

  • Hyeong-Tak Lee;Hey-Min Choi
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.3
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    • pp.281-287
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    • 2023
  • Establishing a ship's passage plan is an essential step before it starts to sail. The research related to the automatic generation of ship passage plans is attracting attention because of the development of maritime autonomous surface ships. In coastal water navigation, the land, islands, and navigation rules need to be considered. From the path planning algorithm's perspective, a ship's passage planning is a global path-planning problem. Because conventional global path-planning methods such as Dijkstra and A* are time-consuming owing to the processes such as environmental modeling, it is difficult to modify a ship's passage plan during a voyage. Therefore, the D* algorithm was used to address these problems. The starting point was near Busan New Port, and the destination was Ulsan Port. The navigable area was designated based on a combination of the ship trajectory data and grid in the target area. The initial path plan generated using the D* algorithm was analyzed with 33 waypoints and a total distance of 113.946 km. The final path plan was simplified using the Douglas-Peucker algorithm. It was analyzed with a total distance of 110.156 km and 10 waypoints. This is approximately 3.05% less than the total distance of the initial passage plan of the ship. This study demonstrated the feasibility of automatically generating a path plan in coastal navigation for maritime autonomous surface ships using the D* algorithm. Using the shortest distance-based path planning algorithm, the ship's fuel consumption and sailing time can be minimized.

Nutrient Recycling : The European Experience - Review -

  • Hall, J.E.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.4
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    • pp.667-674
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    • 1999
  • Intensive livestock production has increased dramatically in Europe since the 1960s, particularly. in Northern and Central European countries, resulting in large increases in the nutrient pollution of surface and ground waters and in atmospheric emissions of ammonia. This has arisen due to inadequate management of the large amounts manure produced, particularly where there has been insufficient land area used for efficient nutrient reuse in crop production. Nutrient pollution from intensive livestock production has progressively degraded the quality of water resources in many parts of Europe, with eutrophication of many inland and coastal waters, as well as soil acidification and ecosystem degradation. These problems have been known for many years, and although there are various international agreements on transboundary pollution, it is largely left to individual countries to set and enforce standards. Consequently, a number of different approaches are employed, although the common feature of these is to encourage farmers to use the nutrients in animal manures efficiently according to crop requirements, which also reduces the potential for accumulation in soil and subsequent loss to the environment. This paper reviews nutrient production and use in Europe and some of the strategies employed to avoid and reduce nutrient pollution.

Nitrate Removal and Recycling Technique (질산 제거 및 재이용 기술)

  • Sim, Sang Jun;Lee, Kyung Hee;Cho, Young Sang
    • Clean Technology
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    • v.3 no.2
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    • pp.31-33
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    • 1997
  • Nitrate contamination in surface water and ground water have increased in Korea. This trend has raised concern because nitrates caused methemoglobinemia in infants. To remove nitrates from waters, various purification processes including ion-exchange, biological denitrification, and chemical denitrification are currently in use for the treatment of water. However, little economically advantageous process exists for the industrial scale treatment of effluents highly polluted with nitrates. A new process has been developed for nitrate and other salts removal from polluted waters. Alumina cement and lime served as precipitating agents to remove nitrate with stirring at basic pH. Decreasing alumina content in alumina cement result in a increasing in nitrate removal yield. Stable removal of nitrate(1000mg/L) was readily achieved by two-stage removal process.

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A New Record of Campylaspis fusiformis (Crustacea: Cumacea: Nannastacidae) from Korea

  • Lee, Chang-Mok;Hong, Soon-Sang;Lee, Kyung-Sook
    • Animal Systematics, Evolution and Diversity
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    • v.28 no.1
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    • pp.54-58
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    • 2012
  • This study dealt with cumacean specimens collected from the shallow waters of the South Sea and East Sea, Korea. Campylaspis fusiformis Gam$\hat{o}$, 1960 belonging to the family Nannastacidae is newly recorded to Korean fauna. This species resembles C. pumila and C. striata in having a similar body form and a pair of narrow lateral sulcuses on the carapace, but it is easily distinguished from them by the dactylus of the pereopod 2 which is more than 3.5 times the length of the propodus and bears many setae (about 20) on the surface. This species mainly occurs in the Korean and Japanese waters.

Depth contours appeared on SAR images by interactions between tidal current and bottom topography

  • Kim, Tae-Rim
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.692-694
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    • 2006
  • X-SAR images taken on the coastal waters of Hwanghe province in Korea during SIR-C/X-SAR campaign in April and October 1994 are analysed. The SAR images show the peculiar signatures like nail marks, curved long string, and vortex streets patterns and they all seem to be produced by strong interactions between the topography in the coastal waters and tidal currents. The nail mark signatures are located at the same position of small scaled sand banks and the curved line patterns are almost identical to the outer boundary of large sand banks. Based on the tidal record, all the three images are taken at the almost same phase of tidal cycles, which are close to the low tide. It seems that bottom shapes are more strongly appeared on the SAR images when the tidal currents are slow. The front between two different current velocities caused by the flows along the steep boundaries of sandbanks is also the main factors imprinting the bottom features to the sea surface SAR images

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On Conditions of Phytoplankton Blooms in the Coastal Waters of the North-Western East/Japan Sea

  • Zuenko, Yury;Selina, Marina;Stonik, Inna
    • Ocean Science Journal
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    • v.41 no.1
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    • pp.31-41
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    • 2006
  • Seasonal changes of abundance of the main phytoplankton groups of species (diatoms, dinoflagellates, chrysophytes, small flagellates and cryptophytes) and a set of environmental parameters were investigated in coastal and pre-estuarine waters of Peter the Great Bay (East/Japan Sea) in May-October of 1998 and 1999. Three periods of mass development were revealed: spring, summer and autumn blooms, with successive change of species. The conditions favourable for each group of species were determined. Driving mechanisms of the succession include nutrients transport through seasonal pycnocline by turbulent mixing, terrestrial nutrients supply by monsoon floods, nutrients supply by upwellings, and light control by the thickness of upper mixed layer. Summer succession could be explained by a simple SST-MLD diagram similar to Pingree S-kh diagram with sea surface temperature as indicator of stratification (S) and mixed layer depth as indicator of light availability (kh).

ICS(Iron oxide Coated Sand)를 이용한 비소 제거

  • 최형진;장윤영;양재규
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.04a
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    • pp.314-317
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    • 2003
  • The overall objective of the adsorption study of arsenic was to elucidate the ability of iron coated sand(ICS), synthesized in the laboratory, to remove arsenic from polluted waters. Batch tests were conducted to provide a relation between arsenic removal and iron content of ICSs. The ICS, developed in the laboratory by coating iron onto the surface of ordinary sand by a simple and easy process has proved as an effective medium for use in removal of arsenic from waters over a wide range of particle sizes of ICS. The composite media is inexpensive to prepare and could serve as the basis of a useful arsenic removal process in variety settings.

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First record of Odontozona arbur(Decapoda: Stenopodidae: Odontozona) from Korea

  • Lee, Seok Hyun
    • Journal of Species Research
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    • v.9 no.3
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    • pp.247-250
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    • 2020
  • Shrimp of the family Stenopodidae occurr in tropical, subtropical and warm temperate parts of the world. Thirty-seven species of four genera (Juxtastenopus, Odontozona, Richardina, and Stenopus) of the family Stenopodidae have been reported in the world. Among them, only Stenopus hispidus of the family Stenopodidae has been recorded from Korean waters. The stenopodid shrimp, Odontozona arbur is reported for the first time from Korea. During a taxonomic survey of the deacapod crustaceans in Korean waters, O. arbur was collected by scuba diving in approximately 14 m depth from the Munseom Islet, in Jejudo Island on 28 Jun 2018. Odontozona arbur is the second species of the family Stenopodidae in Korea. It is easily distinguished from other species of this family in Korea by the entire dorsal surface of the abdominal somites. The morphology of this species is described and illustrated herein.

First Report of Two Diogenid Species of Hermit Crabs (Crustacea: Decapoda: Anomura) from Korea

  • Jung, Jibom;Kim, Won
    • Animal Systematics, Evolution and Diversity
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    • v.31 no.2
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    • pp.107-113
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    • 2015
  • Two diogenid hermit crab species, Dardanus lagopodes and Diogenes deflectomanus, are newly reported from Korea. Dardanus lagopodes is distinguished from the other species of genus Dardanus in Korea by having setae with cream-colored tips on the cephalothorax and the following characteristics: ocular peduncles somewhat longer than antennular peduncles, and the pereopod without a longitudinal sulcus and scute-like projections. Diogenes deflectomanus is similar to D. nitidimanus but can be distinguished by having the fixed finger of the left cheliped bent slightly downwardly and the following characteristics: slightly shorter ocular peduncle, elongated left cheliped with small granules on the surface, right cheliped without calcareous teeth on the cutting edge of the dactylus, and the minute spine of post-median margin of the telson is not well developed. The geographical distributions of these two species are extended by the present study. In particular, D. deflectomanus in the current study is the first report outside Chinese waters. Now, 20 species of the family Diogenidae are known in Korean waters.