• 제목/요약/키워드: sinking

검색결과 445건 처리시간 0.02초

6월중 가막만의 수온, 염분 및 투명도 분포 (Distributions of Water Temperature, Salinity and Transparency in Kamak Bay on June)

  • 이규형;최규정
    • 한국수산과학회지
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    • 제18권2호
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    • pp.157-165
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    • 1985
  • 어장환경관리의 기본자료를 얻기 위하여 1984년 6월중에 가막만에서 실시한 해양관측자료를 가지고 상기만의 밀물과 썰물시 해황분포를 알아보고 그 특성이 지형적 요인에 의해 크게 좌우됨을 살폈다. 가막만은 두개의 만구와 돌출한 도서 및 지세 등 그 지형적 여건에 의해 4개의 특징적 수괴가 나타난다. 내만수는 내륙의 영향이 강한 정체성을, 여수항수는 섬진강 영향이 큰 저염의 외해성을, 만외수는 해저난류 또는 와류발생으로 수직균질한 외해성을, 중간수는 만외수와 내만수의 중간성격이다. 밀물때 양만구로 유입한 해수는 대략 소경도와 항대를 연결하는 선에서 만난다. 군내리근에서는 지형성 와류 혹은 해저난류가 발생하는 것으로 추정되는데, 밀물때는 해수의 침강이, 썰물때는 저층수의 특성치가 보여지며 그 크기는 약 3 km 까지 뻗친다.

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Establishment strategy of a rare wetland species Sparganium erectum in Korea

  • Kim, Seo Hyeon;Nam, Jong Min;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • 제41권8호
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    • pp.202-212
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    • 2017
  • Background: To reveal establishment strategy of Sparganium erectum, we tried to find realized niche of adults through field survey and effects of water level on the establishment process through mesocosm experiments. Results: In the field survey, the height and coverage of community living in deeper water were greater than those of community living in shallow water. There was no statistically significant difference (p > 0.05) in the means of water and soil properties between the two communities. In mesocosm experiments, we found no correlation between water levels and germination rates, but S. erectum seedlings have characteristics of post germination seedling buoyancy when S. erectum seeds germinated in inundation conditions. Shoot height, total leaf length, and survival rates of sinking seedlings in shallow water levels at -5, 0, and 5 cm were higher than those in deeper water levels at 10 and 20 cm. Floating seedlings established in water levels of 3 and 6 cm only. The seedlings could live up to 6 weeks in floating state but died if they were unable to establish. Conclusions: The water level around adult S. erectum communities in the field were different from the water level at which S. erectum seedlings can survive in the mesocosm experiments. The findings provided not only understanding of S. erectum habitat characteristics but also evidence to connect historical links between the early seedlings stage and adult habitat conditions. We suggested the logical establishment strategy of S. erectum based on the data.

넙치 육상수조 양식에 있어 편조류 Cochlodinium polykrikoides의 구제를 위한 화학적 처리 (Experimental Chemical Treatments for the Control of Dinoflagellate Cochlodinium polykrikoides in the Land-based Culture of Olive Flounder Paralichthys olivaceus)

  • 류호영;심정민;방종득;이주
    • 한국양식학회지
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    • 제11권3호
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    • pp.285-294
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    • 1998
  • When Cochlodinium polykrikoides came into the culture tanks through influent cultivated water during the red tides, hundred thousands of commercial flounders were concomitantly killed and many culturists suffered from a great deal of financial loss in the east coast of Korea. It is charactrized by high sinking rate after sunset and the formatino of clump which results in oxygen deficiency by its respiration at tank bottom under condition. We investigated the efficacy of hydrogen peroxide and chlorine dioxide, known to form radicals, for extermination of red tide organism C. polykrikoides. When C. polykrikoides seawater with a density of 6,000 cells/$m\ell$ was treated with 14, 28 and $42mg/\ell$ of hydrogen peroxide, its survival rate was markedly decreased to 9.8, 0.8 and 0.3% respectively immediately after 6 hours of treatments whereas when it was treated with 1.5, 2.1 and $3.0mg/\ell$ chlorine dioxide, its survival rate showed 87.7, 81.3 and 80.1 and 80.1% respectively at the same treatment time. Hydrogen peroxide was the effective agent since it has scarcely injured the cultured olive flounder when exposed to the tested concentration range of $14~28mg/\ell$ with the extermination of almost3 C. polykrikoides during the experimental period of 5 days and has shown the oxygen increase of approximately $1.23mg/\ell$ 2 hours immediately after the flounder by C. polykrikoides in the land-based culture tank is assumed to be not by the toxicity of itself but by oxygen dificiency from the rapid respiration of dinoflagellate clump sunken to the tank bottom.

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감은사지 삼층석탑 구조에 관한 연구 (A study on the structure of the Three storied Stone pagoda in Gameunsa Temple site.)

  • 남시진
    • 건축역사연구
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    • 제17권3호
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    • pp.7-21
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    • 2008
  • Three-story Stone pagodas in Gameunsa Temple site, one of the early staged stone pagodas, has been known as a standard of Silla stone pagodas. A stone pagoda is not only a stone art work and but also a stone architecture. In understanding the stone pagoda it is very important to be approached with technological side in which we can investigate the stone pagoda deeply and as well as to have been approached with art historical view. Also it needs that we should see the stone pagoda in view of structural safety. We can get many high technique from our ancestors who made Gameunsajiseoktap. 1. To reduce any deformation such as relaxation and sinking of members which is caused by a heavy load the members such as the lower tier of the base is made up of the foundation stone and side stone in each, comprising one stone. 2. A special construction method for connection between wall stone and column stone in stereobates was invented. It is to make column stone projected partially and wall stone be caved in that two members should be jointed well. This unique method is not used any longer after the three-story Stone pagodas in Gameunsa Temple Site. 3. In each side upper and lower member are not engaged as the size of roof stones and support stones of roof stones are different. It can be done for a distribution of perpendicular load and a prevention for relaxation of members. 4. It makes sure that to make upper ends of support stones 10mm lower was to be avoid upper loads to it judging from survey in disassemblying east pagoda. It proves that ancestors who made this stone pagoda had a technique to understand the structural matters to make small members as big as possible, not to engage in joint, to avoid in ends of members from upper load.

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한의사 맥진 가압력 재현에 대한 고찰 (Considerations on an Oriental Medical Doctor like Indentation System)

  • 이전;우영재;전영주;이유정;유현희;김종열
    • 한국한의학연구원논문집
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    • 제14권3호
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    • pp.113-119
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    • 2008
  • In pulse diagnosis, the indentation pressure is one of the most important factors as well as the change of pulse shape and the distribution of pressure via time. But, on the oriental medical doctor's indentation pressure control, the understandings of the neurophysiological meanings and mechanisms have been lacked. So, in this paper, we considered on these issues and then proposed a proper system which can imitate the OMD's indentation pressure control mechanisms. As a result, both tactile information and kinesthetic information were found to be essential to the indentation pressure control so that a system, which can measure both the physical indent pressure and the displacement of an indentation arm, has been proposed. With this proposed system, while the indentation was being controlled through the moving step number of the step motor, the physical indentation pres sure and displacement of the indentation arm were measured. From these measured data, the relationships between the moving step number and both physical indentation pressure and displacement were revealed to have linear characteristics in early phase and to have nonlinear characteristics in latter phase. Additionally, three types of graph were generated whose X axis means the moving step number, the physical indentation pressure and the displacement respectively and Y axis means the pulse pressure. By comparing these graphs, we come to conclude that different concepts on indentation pressure control cause different diagnostic results on floating/sinking degrees for the same subject. Consequently, an indentation system for the pulse diagnosis should be able to provide both the tactile information and kinesthetic information, that is, the physical indentation pressure and the displacement of the indentation arm. In future, the proposed system should be optimized to the pulse diagnosis environment and how to combine the both information for more reliable diagnosis should be studied.

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여성 수족냉증 환자의 임상 특성에 관한 연구 (A Study of Clinical Characteristics of Female Patients with Cold Hypersensitivity on Hands and Feet)

  • 권정연;김영지;공경환;전찬용;고호연;고유미
    • 대한한의학회지
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    • 제39권2호
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    • pp.64-79
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    • 2018
  • Objectives: This study was aimed to research clinical characteristics of female patients with cold hypersensitivity on the hands and feet compared with non-cold hypersensitivity group. Methods: 134 women patients were collected from 6 Korean medicine hospitals, and divided into 2 groups(cold hypersensitivity group and non-cold hypersensitivity group). This survey was composed of 19 questions related to clinical symptoms of cold hypersensitivity. Results: We found out the differences between 2 groups in 10 questions among 19 questions in the survey results. (Body Type, Energy, Digestibility, Skin Type, Facial Complexion, Chill, Dry Mouth and Thirst, Preference between Coolness and Warmth, Thickness of Tongue Fur, Floating and Sinking of Pulse) Conclusions: From these results, Patients with cold hypersensitivity on hands and feet have relative clinical characteristics as follows. They are relatively weak and lethargic. They have dry skin and look more pale. They feel chill easily and have dry mouth and thirst. They prefer warmth and have indigestion more. They had more various infirm and ill clinical characteristics compared with the other group from the view of Korean medicine.

Downward particle flux in the eastern Bransfield Strait, Antarctica

  • Kim, Dongseon;Kim, Dong-Yup;Jeonghee Shim;Kang, Young-Chul;Kim, Taerim
    • Journal of the korean society of oceanography
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    • 제38권1호
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    • pp.1-10
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    • 2003
  • A time-series sediment trap was deployed at a depth of 1034 m in the eastern Bransfield Strait from December 25, 1998 to December 24, 1999. Particle fluxes showed large seasonal variation; about 99% of the annual total mass flux (49 g m/sup -2/) was collected during the austral summer and fall (January-March). Settling particles consisted primarily of biogenic silica, organic carbon, calcium carbonate, and lithogenic material. Biogenic silica and lithogenic material predominated settling particles, comprising 36% and 30% of the total mass flux, respectively, followed by organic carbon, 11% and calcium carbonate, merely 0.6%. The annual organic carbon flux was 5.4 g C m/sup -2/ at 1000 m in the eastern Bransfield Strait, which is greater than the central Strait flux. The relatively lower flux of organic carbon in the central Bransfield Strait may be caused by a stronger surface current in this region. Organic carbon flux estimates in the eastern Bransfield Strait are the highest in the Southern Ocean, perhaps because of the fast sinking of fecal pellets, which leads to less decomposition of organic material in the water column. Approximately 5.8% of the organic carbon produced on the surface in the eastern Bransfield Strait is exported down to 1000 m; this percentage exceeds the maximum EF/sub 1000/ values observed in the Atlantic and Southern Oceans. The eastern Bransfield Strait appears to be the most important site of organic carbon export to the deep sea in the Southern Ocean.

POE 오일 나노유체의 열물성과 분산성 평가를 위한 실험적 연구 (Experimental Study on Dispersion and Thermal Properties of Nanofluids based on POE Oil)

  • 이규선;이근안;이종섭;이형욱;박성준;이영선;김상훈;장석필;김정배
    • 한국태양에너지학회 논문집
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    • 제32권3호
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    • pp.170-177
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    • 2012
  • To apply the nanofluids into the general vapor compression cycle, basically have to know the thermal properties including thermal conductivity and dynamic viscosity. And needs to show the dispersion characteristics for various nanofluids and concentrations. So, firstly this study showed experimentally the thermal properties for various concentration (0.1%~0.7%, as mass balance) and temperature($20^{\circ}C{\sim}40^{\circ}C$) on $Al_2O_3$, $TiO_2$, and CuO nanofluids using base fluid as POE oil that has used in the scroll compressor for various refrigeration system. From the results, the dynamic viscosity of nanofluids was considerably changed from the base POE oil. And, the dispersion characteristics of various nanofluids using the simple methods like as analyzing the RGB value or measuring the sinking height of nanofluids were showed experimentally. Through the results, the dispersion characteristics of $Al_2O_3$ nanofluid was better than those of $TiO_2$, and CuO nanofluids not considering the real refrigeration cycle rurming conditions.

중층 트롤 시스템의 계측 및 운동 특성 (Measurements of Midwater Trawl System and Dynamic Characteristics)

  • 이춘우
    • 수산해양기술연구
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    • 제34권3호
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    • pp.294-301
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    • 1998
  • Towing performance of a midwater trawl system was examined aboard the training ship KAYA(2900ps) at the East Sea using the midwater trawl gear that had been designed and manufactured in accordance with the vessel. In this experiment, the trawl system data, the towing speed, the length and tension of the warp, net mouth height, and the depth of otter boards and net were measured and analyzed. The results are as follows: 1. In case of heaving in the warp with constant towing speed, the tension was suddenly increased and then again was reduced and after returned to the original steady state tension. At this time, net height was reduced a bit by ascension of ground rope, but returned to it’s original value. In the case where the warp was paid out, the tension was suddenly decreased and after increased and then returned to the tension of the original state, and the net height was greatly increased instantly by the sinking of the ground rope and then returned to the steady state 2. In the case of increased towing speed mm constant warp length, the tension was increased, and reducing the net height, the gear depth was decreased. On the other hand, in the case where towing speed was reduced, the tension was reduced and the gear depth and net height was increased. 3. Otter boards show a swing motion in the scope of 5~ 10m continuously. Otter boards responded to the state change of the trawl system at first, and then the motion of the net appeared. 4. The depth of net center was about 20m deeper than that of the otter boards, it shows about 0.4 times the warp length at the 4knots towing speed.

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오징어 가공 부산물의 해양투기에 따르는 주변해양환경의 영향에 대한 검토 (Examination of the effect on the surrounding marine environment by disposing of a squid by-product)

  • 황보규;신현옥;김민선;강경미;남택정
    • 수산해양기술연구
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    • 제47권1호
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    • pp.27-36
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    • 2011
  • Squid by-product like viscera has just been recognized as one of the serious pollutants on the surrounding marine environment in Ulleung island of Korea. The effect as a marine pollutant, however, has not been examined and evaluated properly. It was carried out the comprehensive examination of the marine pollution by disposing squid by-products. The sediments and water qualities were investigated in several positions, including the dumping position around Ulleung island. It is also estimated a spreading of by-product in terms of estimating the sinking speed and evaluating the attracting characteristics as a feed. As a result, There were no significant pollutions of the sediment and water quality. The spreading of by-product by the local current was 2-2.5 times of the depth, and it will become longer in spring tide. It was confirmed that the squid by-product has attracting ability for local fish by acoustical survey. Furthermore, it can be useful for the local fish species as feeds.