• 제목/요약/키워드: Cold Water Zone

검색결과 74건 처리시간 0.026초

Temporal Variation of Phytoplankton Community Related to Water Column Structure in the Korea Strait

  • Lee, Yong-Woo;Park, Hyun-Je;Choy, Eun-Jung;Kim, Yun-Sook;Kang, Chang-Keun
    • Ocean and Polar Research
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    • 제32권3호
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    • pp.321-329
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    • 2010
  • Photosynthetic pigments, nutrients, and hydrographic variables were examined in order to elucidate the spatio-temporal variation of water column structure and its effect on phytoplankton community structure in the western channel of the Korea Strait in fall 2006 and spring 2007. High phytoplankton biomass in the spring was associated with high salinity, implying that nutrients were not supplied by coastal waters or the Yangtze-River Diluted water (YRDW) with low salinity. Expansion of the Korea Strait Bottom Cold Water (KSBCW) and a cold eddy observed during the spring season might enhance the nutrient supply from the subsurface layer to the euphotic zone. Chemotaxonomic examination showed that diatoms accounted for 60-70% of total biomass, followed by dinoflagellates. Nutrient supply by physical phenomena such as the expansion of the KSBCW and the occurrence of a cold eddy appears to be the controlling factors of phytoplankton community composition in the Korea Strait. Further study is needed to elucidate the mechanisms by which the KSBCW is expanded, and its role in phytoplankton dynamics.

수종 상록식물의 월동 중 수분상태 (Water Status of Several Evergreen Plants during Overwintering)

  • Kim, Joon-Ho;Chang-Seok Lee
    • The Korean Journal of Ecology
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    • 제9권4호
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    • pp.201-208
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    • 1986
  • The water status of the leaves of several evergreen plants was investigated in order to discuss the geopgraphical distribution of them. Relastionship between relative water content and water potential of the leaves showed linear decrease for evergreen conifers but exponential decrease for Korean box tree (Buxus microphylla var. koreana). On the basis of the leaf water potential, the water status of the conifers during wintering was distinctly divided into three periods; hardening, cold resistance and dehardening, but lacking in those periods for the Korean box tree, where the status continously decreased. In the cold resistance the leaf water potentials were -23 bar for both spruce (Picea jezoensis) and yew (Taxus cuspidata). From these results and threshold temperature at beginning of hardening, distribution of the conifers was explained that in order of the red pine, the Korean white pine, the yew and the spruce the distribution could be extended at higher altitudes and in more northward areas, whereas the distribution of the Korean box tree was restricted to the lowland of temperate zone.

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Analytical Model of Salt Budget in the Upper Indian River Lagoon, Florida USA

  • Kim, Young-Taeg
    • Ocean and Polar Research
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    • 제26권1호
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    • pp.33-42
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    • 2004
  • Effect of freshwater discharge on the long-term salt balance in the Northern and Central Indian River Lagoon (IRL) is successfully simulated by a new analytical solution to a water balance-based one-dimensional salt conservation equation. Sensitivity tests show that the salinity levels drop abruptly even during the dry season (November to May) due to the high surface runoff discharge caused by tropical storms, depressions, and passage of cold fronts. Increasing surface runoff and direct precipitation has risen by ten times, lowering the salinity level down to 12psu in the Northern Central zone, and to 17 psu in the Northern zone. However, the salinity level in the Southern Central zone has decreased to 25 psu. High sensitivity of the Northern Central zone to freshwater discharge can be partially explained by a rapid urbanization in this zone. During the dry season, less sensitivity of the Southern Central zone to the increased surface runoff is attributed to the proximity of the zone to the Sebastian Inlet and a strong diffusion condition possibly resulting from the seawater intrusion to the surficial aquifer at the Vero Beach. During the wet season, however, the whole study area is highly sensitive to freshwater discharge due to the weak diffusion conditions. High sensitivity of the IRL to the given diffusion conditions guarantees that the fresh-water release occurs during strong wind conditions, achieving both flood control in the drainage basin and a proper salinity regime in the IRL.

도시근교 택지개발지역의 경관계획지표 적용방안 (Applying of Indicators for Landscape Planning in Building Lots Development District around Urban Fringe)

  • 김용수;박찬용
    • 농촌계획
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    • 제13권3호
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    • pp.51-60
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    • 2007
  • In terms of the indicators by the type for the landscape plan per the district nit, geographic ecology indicators were the items such as water, water system, topography and climate, while biological ecology indicators were the items such as green zone size, green zone ratio, biotope size and distribution. The sensory and visual indicators were the items such as view point, view axis and skyline, and the accessibility indicator items for the green zone were applied as the socially used indicators. As for the application method according to each indicator, the water or water system was expressed and applied through the slopes and elevation topographic analysis drawings, the climate was expressed and applied through the main direction of the wind and the cold wind pass alley drawings. As for the green zone size and green zone ratio, the land use according to the status and housing area development was compared to present the measured figures. In case of the biotop size and the distribution item, the range was limited to the preparation of the biotope drawings for the focused preservation. As for the view point and view axis, the view point was selected according to the view point to prepare and apply the view analysis drawing in which the view area to be preserved is analyzed. As for the skyline, its landscape photo was composed with the housing area shape, and then skyline photography was applied as the plan in order to propose and consider the various shapes of the skyline. As for the accessibility to the peen zone, the network drawing was drawn to reflect the users' accessibility and continuity of the green zone formed and preserved according to the land use plan and then the drawing was prepared and proposed as the applicable plan.

하기주간의 국소냉방과 토마토 배꼽썩음병 발생에 관한 연구 (Studies on Zone Cooling of Greenhouse in the Daytime in Summer and Occurrence of Blossom - End Rot in Tomato Plants)

  • 조일환;우영회;인과홍중;교본강
    • 생물환경조절학회지
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    • 제3권1호
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    • pp.36-41
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    • 1994
  • 본 시험의 목적은 온실의 주년계획이용을 위해서 하기주간 냉방의 방법으로 heat pump를 이용한 냉수냉방과세무냉방의 효율성을 검사했고 하기 토마토 배꼽썩음병 발생을 억제하기 위하여 냉방과 함께 과실에 송풍처리와 식물체 전체의 공기유동을 촉진시켜주는 처리를 했다. 시험결과는 다음과 같다. 1) 냉수냉방구간 기온은 13시경 온실내 기온보다 약 1$0^{\circ}C$이상 낮았고, 세무냉방구간 하부의 기온은 13시경 온실내 기온보다 약 5$^{\circ}C$ 낮았다. 2) 과실에 송풍처리는 냉방방법에 상관없이 배꼽썩음병이 방지됐고, 냉수냉방 무송풍구의 배꼽썩음병 발생율은 34.5%, 세무냉방 무송풍구는 54.5%, 세무순환냉방구는 78%였다. 냉방효율면에서는 냉수냉방 방법이 충분히 생육한계온도 이하로 냉각되었고, 배꼽썩음병 발생율에서도 세무냉방보다 낮았다. 세무냉방은 재배구간의 공기를 유동시킴으로서 약 24%증가했다. 그러므로 토마토 배꼽썩음병 발생에 관한 환경요인은 온도보다는 습도가 밀접한 관계가 있는 것으로 생각되어진다.

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자하거 저온숙성비누의 세안전·후 안면피부상태 비교연구 (Comparative Study on Facial Skin Conditions Before and After Washing Face with Placenta CP Soap)

  • 구진숙
    • 대한본초학회지
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    • 제38권2호
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    • pp.35-41
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    • 2023
  • Objectives : Washing face is the first step in skin beauty and health. I wanted to study the cleansing effect by using Placenta cp (cold process) soap. The skin condition is greatly influenced by the external environment such as lifestyle, drinking, smoking, and stress etc. I tried to measure the skin change state without environmental factors. Methods : In order to examine the effect before and after washing face under the same conditions, the same water and towel were used in the same place. The skin test was performed before and 10 minutes after washing. As a control group, a case of washing with water and foam cleanser. I compared and analyzed three cases: water washing, F/C (foam cleanser) washing, and Placenta cp soap washing. Results : In the case of water washing, it was significantly reduced in pores and increased in facial temperature. In the case of F/C washing, the facial temperature was significantly increased, but the decrease in moisture. In the case of washing with Placenta cp soap, significant reductions in T-zone and U-zone oil content, reduction in pore size, and increase in facial skin temperature were observed. Conclusion : In the case of Placenta cp soap, it is thought to be suitable for oily skin type, because of significant decrease in T-zone and U-zone oil content. It is thought to have the effect of increasing blood circulation in the facial skin and to reduce pores for oily skin types.

동해 전선역 동물플랑크톤 군집 : 1. 종 목록, 우점종 분포, 종간 유연관계 (Zooplankton Community in the Front Zone of the East Sea of Korea (the Sea of Japan) : 1. Species List, Distribution of Dominant Taxa, and Species Association)

  • 박철;최중기
    • 한국수산과학회지
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    • 제30권2호
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    • pp.225-238
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    • 1997
  • 동해 전선역에 분포하는 동물 플랑크톤의 분포 특성을 파악하였다. 우리나라 서해나 남해의 어떤 지역에서 보다도 많은 종류인 $101\~111$개 분류군이 출현하였다. 1994년의 경우에는 Paracalanus parvus, Oikopleura spp., Noctiluca scintillans 등의 난류수 선호종이 주요 우점군으로 나타났고, 상대적으로 수온이 약 $2^{\circ}C$ 낮았던 1995년에는 한류 수역을 선호하는 Metridia lucens와 낮은 수온으로 인하여 아직 성장이 완전히 이루어지지 않은, Calanus copepodid, 미성숙 Sagitta, 갑각류 난 등과 Parathemisto japonica, Conchoecia spp. 등이 우점종으로 나타났다. 수심에 따른 수온 변화가 큰 이지역에서 주요 우점종의 수층별 분포 양상도 종류에 따라 다른 양상을 띠었다. 대체로 난류 수역을 선호하는 종류들은 많은 종이 동시에 적은 개체수로 표층에 주로 분포하는 특성을 보이고, 한류 수역을 선호하는 종은 적은 종류가 많은 양 집중적으로 나타나는 특성을 보였다. 따라서, 전선역의 높은 종 다양성은 난류수의 영향, 높은 생물양은 한류수의 영향이라고 할 수 있었다.

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The Chlorophyll Concentration in the Southwestern East Sea Observed by Coastal Zone Color Scanner (CZCS)

  • Lee Dong-Kyu;Son Seung-Hyun
    • Fisheries and Aquatic Sciences
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    • 제3권1호
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    • pp.8-13
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    • 2000
  • Monthly mean chlorophyll concentration in the East Sea was estimated from the ocean color observed by the Coastal Zone Color Scanner (CZCS) on Nimbus-7 satellite which had performed various remote sensing missions from 1979 to 1986. The areas of high chlorophyll concentration were found in the sea between Siberia coast and Sakhalin Island, in the Donghan Bay and in the Ulleung Basin. In the southwestern East Sea, especially in the area near Ulleung Island, the yearly maximum chlorophyll concentration occurred in December. The chlorophyll concentration in Ulleung Basin in December was about two times higher than during spring bloom in April. The early winter bloom occurred in the warm side of the front that was formed between warm water from the East China Sea and nutrition rich cold water from the northern East Sea.

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ADVANCED DVI+

  • Kwon, Tae-Soon;Lee, S.T.;Euh, D.J.;Chu, I.C.;Youn, Y.J.
    • Nuclear Engineering and Technology
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    • 제44권7호
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    • pp.727-734
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    • 2012
  • A new advanced safety feature of DVI+ (Direct Vessel Injection Plus) for the APR+ (Advanced Power Reactor Plus), to mitigate the ECC (Emergency Core Cooling) bypass fraction and to prevent switching an ECC outlet to a break flow inlet during a DVI line break, is presented for an advanced DVI system. In the current DVI system, the ECC water injected into the downcomer is easily shifted to the broken cold leg by a high steam cross flow which comes from the intact cold legs during the late reflood phase of a LBLOCA (Large Break Loss Of Coolant Accident)For the new DVI+ system, an ECBD (Emergency Core Barrel Duct) is installed on the outside of a core barrel cylinder. The ECBD has a gap (From the core barrel wall to the ECBD inner wall to the radial direction) of 3/25~7/25 of the downcomer annulus gap. The DVI nozzle and the ECBD are only connected by the ECC water jet, which is called a hydrodynamic water bridge, during the ECC injection period. Otherwise these two components are disconnected from each other without any pipes inside the downcomer. The ECBD is an ECC downward isolation flow sub-channel which protects the ECC water from the high speed steam crossflow in the downcomer annulus during a LOCA event. The injected ECC water flows downward into the lower downcomer through the ECBD without a strong entrainment to a steam cross flow. The outer downcomer annulus of the ECBD is the major steam flow zone coming from the intact cold leg during a LBLOCA. During a DVI line break, the separated DVI nozzle and ECBD have the effect of preventing the level of the cooling water from being lowered in the downcomer due to an inlet-outlet reverse phenomenon at the lowest position of the outlet of the ECBD.

한국 서해 중부 연안역의 수질환경 특성 (Water Quality Characteristics Along Mid-western Coastal Area of Korea)

  • 임동일;강미란;장풍국;김소영;정회수;강양순;강영실
    • Ocean and Polar Research
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    • 제30권4호
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    • pp.379-399
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    • 2008
  • Spatial-temporal variations in physiochemical water qualities (temperature, salinity, DO, SPM, POC and nutrients) of surface and bottom waters were investigated along the mid-western coastal area (Taean Peninsula to Gomso Bay) of Korea. Spatial distribution patterns of temperature and salinity were mostly controlled by the physical mixing process of freshwater from Geum River and/or Gyunggi Bay with nearby coastal water. A strong tidal front is formed off Taean Peninsula during spring and summer. Seasonal variations in nutrient concentrations, lower in spring and summer and higher in fall and winter, are primarily regulated by magnitude of phytoplankton occurrence rather than freshwater loadings into the bay. Based on seasonal and spatial variability of physicochemical parameters, water quality of the study area can be divided into four water masses; Gyunggi Bay-influenced Water Mass (GBWM), Geum River-influenced Water Mass (GRWM), Yellow Sea Bottom Cold Water Mass (YSBCWM) and Cheonsu Bay Water Mass (CBWM). Water quality of the GBWM (Taean Peninsula coastal area), which has relatively low salinity and high concentrations of nutrients, is strongly controlled by the Gyunggi Bay coastal water, which is under influence of the Han River freshwater. In this water mass, the mixed layer is always developed by strong tidal mixing. As a result, a tidal front is formed along the offshore boundary of the mixed layer. Such tidal fronts probably play an important role in the distribution of phytoplankton communities, SPM and nutrients. The GRWM, with low salinity and high nutrients, especially during the flood summer season, is closely related to physiochemical properties of the Geum River. During the flood season, nutrient-enriched Geum River water mass extends up to 60 km away from the river mouth, potentially causing serious environmental problems such as eutrophication and unusual and/or noxious algal blooms. Offshore (<$30{\sim}40m$ in water depth) of the study area, YSBCWM coupled with a strong thermocline can be identified in spring-summer periods, exhibiting abundant nutrients in association with low temperature and limited biological activity. During spring and summer, a tidal front is formed in a transition zone between the coastal water mass and bottom cold water mass in the Yellow Sea, resulting in intensified upwelling and thereby supplying abundant nutrients to the GBWM and GRWM. Such cold bottom water mass and tidal front formation seems to play an important role in controlling water quality and further regulating physical ecosystem processes along mid-western Korean coastal area.