• Title/Summary/Keyword: Sea levels

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Variation and Profile of Paralytic Shellfish Poisoning Toxins in Jinhae Bay, Korea

  • Mok, Jong-Soo;Song, Ki-Cheol;Lee, Ka-Jeong;Kim, Ji-Hoe
    • Fisheries and Aquatic Sciences
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    • v.16 no.3
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    • pp.137-142
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    • 2013
  • To understand critical aspects of paralytic shellfish poisoning (PSP) in a chief area of bivalve production in Korea, seasonal variation in PSP toxins in bivalves collected from Jinhae Bay, Korea in 2009 was surveyed by the pre-column high-performance liquid chromatography oxidation method. We also confirmed the profiles of major bivalves such as oysters Crassostrea gigas and mussels Mytilus galloprovincialis in Jinhae Bay. PSP toxins in the bivalves showed remarkable seasonal variation. PSP toxin levels were detected from April to May in 2009, and the highest total toxin levels at all stations were recorded in May. The major toxins in bivalves were gonyautoxin [GTX] 1&4 and C 1&2; in oysters GTX 2&3 were also detected as major components. GTX 1&4, which showed the highest PSP toxin levels at each station, accounted for the highest proportions of toxin components in mussels and oysters (64.5-71.3% and 41.4-42.4%, respectively). It was also confirmed that the highest toxicity (in ${\mu}g$ saxitoxin [STX] eq/g) was derived from GTX 1&4. The highest total toxicity (in ${\mu}g$ STX eq/g) was approximately 2-8-fold higher in mussels than in oysters collected from the same station. PSP toxin levels in bivalves differed significantly according to the sample collection station. However, the profiles of toxins in the bivalves did not show significant differences during the survey period according to sample collection station. This study shows that PSP toxin levels in some samples from Jinhae Bay were above the regulatory limit in Korea during a specific period in spring.

Na-binding Capacity of Alginate and Development of Sea Tangle Added Kimchi (Alginate의 Na 흡착효과와 다시마 첨가 김치의 개발)

  • 하정옥;박건영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.6
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    • pp.995-1002
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    • 2000
  • In order to Develop a low Na functional kimchi using sea tangle, the Na-binding capacity of alginate in sea tangle along with other dietary fibers was evaluated in vitro. The adding type and amount of the sea tangle that contains alginate in kimhi and characteristics of the sea tangle added kimchi were also studied. Na-binding capacity of various dietary fibers such as cellulose, pectin, gun gum, carageenan, alginates (sodium alginate, alginate, alginate from sea tangle) was measured by equilibrium dialysis method in pH 2 and pH 7 in vitro. Gua gum, carageenan and a group of alginates effectively bound to Na+ Espacially sodium alginate showed high Na-binding capacity of 29.2% in pH of stomach (pH 2.0) and 33.8% in pH of small intestine (pH 7.0), however, the alginate extracted from sea tangle could not bind Na in PH of stomach (pH 2.0), but 27.4% in pH of small intestine (pH 7.0) condition. The content of alginate in sea tangles (dried sea tangle, salted sea tangle and washed salted sea tangle) was 19.8 ~ 22.2% on dry matter basis. The sea tangle added kimchi was prepared with the addition of the flake type (0.5$\times$3 cm) of sea tangle with a quantity of 30% in kimchi from the data of the sensory analysis. The addition of the sea tangle to the kimchi increased the content of soluble dietary fiber, suggesting the Na-binding capacity increased. The sea tangle added kimchi (SK) and sea tangle and fermented anchovy added kimchi (SAK) showed higher levels of reducing sugar and acidity than the control kimchi (CK). In quantitative descriptive analysis (QDA) SK and SAK showed higher score in overall acceptance, and lower score in acidic order than CK, however, SK showed less moldy taste and more fresh acidic taste than SAK.

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Physical Environment Changes in the Keum River Estuary by the Dyke Gate Operation: I. Mean Sea Level and Tide (하구언 수문작동으로 인한 금강 하구역의 물리적 환경변화: I. 평균해수면과 조석)

  • Kwon, Hyo-Keun;Lee, Sang-Ho
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.4 no.2
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    • pp.93-100
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    • 1999
  • Analyzing the tide data taken at Kunsan inner and Outer ports, non-tidal and mean sea level and harmonic constants of major constituents are investigated to examine the effects of the dyke gate operation on the sea level change in Keum River estuary. Non-tidal and annual mean sea levels decrease at Kunsan Inner and Outer ports after the dyke gate operation, especially showing an abrupt drop of non-tidal sea level at Kunsan Inner port. This non-tidal sea level drop results in the mean sea level gradient change between the inner and outer port, which can be mainly explained in terms of the decrease of river discharge from the dyke. Amplitudes of the $M_2$ and $S_2$ tides at the Inner port increase after the dyke gate operation, showing an abrupt jump, and phases of both tides slightly decrease. Amplitude and phase of the $K_1$ and $O_1$ tides show slight changes after the dyke gate operation. This significant change of semi diurnal tide amplitude is believed as a result of superposition of incident tidal wave and reflected tidal wave from the dyke.

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Swimming Suitability and Management of Sea Water for Artificial created Swimming in the Southwestern Sea of Korea (한국 서남해역 인공해수욕장의 적합성 판정과 수질관리 방안)

  • Kim, Do-Hee;Chang, Jin-Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.6
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    • pp.640-645
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    • 2014
  • This study aimed to determine the swimming suitability of sea and to suggest methods to address the problems on sea water color and green plants growing on sediment in the artificial created swimming in the beach of southwestern Korea. Sea water samples were collected from January to December of 2010 and analysis for SS, COD, $NH_4{^+}-N$, TP, MPN, sediment IL, ORP and plants on sediment. The results showed that the sea water under the swimming suitability "level of management" based on the relating high levels of SS and TP, but still suitable for swimming on the basis of MPN. Improving exchange seawater flow, dredging, coating and chemical treatment of polluted sediments in addition to removal of point sources and restriction of non point sources in the study area could improve the sea water quality and swimming suitability of the sea.

Effect of climate change and sea level rise on taking water of South Thai Binhirrigation system in Vietnam

  • Nguyen, Thu Hien;Nguyen, Canh Thai
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.222-222
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    • 2015
  • Vietnam is one of the most vulnarable countries affected by climate change and sea level rise. One of the consequences of climate change and sea level rise is the increase of salinity intrusion into the rivers which is challenging to irrigation systems in coastal areas. This indicates the necessary to study the ability of taking water through sluice gates of irrigation systems in coastal zones, especially in the dry season with the effects of climate change and sea level rise in the future. In this paper, Nam Thai Binh irrigation system is selected as a case study. The irrigation system is one of 22 biggest irrigation systems of the Red River delta in Vietnam located in coastal region. The computed duration is selected in dry season to irrigate for Winter-Spring crops. The irrigation water for the study area is taken from different sluice gates along the Red River and the Tra Ly River. In this paper, MIKE-11 model was applied to assess the ability of taking water for irrigation of the study area in current situation and in the context of climate change and sea level rise senario in 2050 (under the medium emissions scenario (B2) published by the Ministry of Natural Resources and Environment of Vietnam published in 2012) with different condition of water availability. The operation of the gates depends on the water levels and sanility conditions. The sanility and water level at different water intake gates of Nam Thai Binh irrigation system were simulated with different senarios with and without climate change and sea level rise. The result shows that, under climate change and sea water level rise, some gates can take more water but some can not take water because of salinity excess and the total water taking from the different gates along the rivers decrease while the water demand is increase. The study indicates the necessary to study quantitatively some recommended solutions in the study area particularly and in coastal region generally in Vietnam to ensure water demand for irrigation and other purposes in the context of climate change and sea level rise in the future.

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Review of the Melting of West Antarctic Ice Shelves in the Amundsen Sea and Its Influence: Research Issues and Scientific Questions (아문젠해 서남극 빙붕 용융과 영향에 대한 고찰: 연구동향 및 과학적 질문)

  • Seung-Tae Yoon
    • Ocean and Polar Research
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    • v.45 no.3
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    • pp.155-172
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    • 2023
  • The collapse of ice shelves is a process that can severely increase the rise of global sea-levels through the reduction of the buttressing effect of ice shelves and the consequent acceleration of the ice flow of ice sheets. In recent years, the West Antarctic ice shelves in the Amundsen Sea, whose buttressing effect is essential for a great part of the West Antarctic ice sheet, have been experiencing the most rapid melting and thinning in the world. The melting of the West Antarctic ice shelves is caused primarily by heat transported by Circumpolar Deep Water (CDW). For this reason, it is important to investigate ice-ocean interactions that could influence the melting of ice shelves and evaluate the stability of West Antarctic ice shelves. A lot of researchers have been actively investigating the West Antarctic ice shelves in the Amundsen Sea. High-impact journals have recognized the importance of and published studies on ice-ocean interactions occurring near and under the ice shelves as well as the connections among ice shelves. However, in situ observations are limited due to extreme weather and sea-ice conditions near the ice shelves; therefore, many scientific questions remain unanswered. This study introduces the characteristics of the Amundsen Sea and investigate the past and latest research issues in this region. This study also gives suggestions regarding important scientific questions and directions for future research that should help early-career scientists take the lead in future research on the melting dynamics of the West Antarctic ice shelves in the Amundsen Sea.

On the Variations of Monthly Mean Sea Levels along the Coast of Korea (한국연안의 월평균해면의 변화에 대하여)

  • Sok-UYi
    • 한국해양학회지
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    • v.2 no.1_2
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    • pp.24-33
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    • 1967
  • The variations of monthly mean sea levels along the coast of Korea anre studied graphic and harmonic methods with the data from 9 tides stations and compared with the variations of atmospheric pressure and the changes in density of sea water measured near some of the stations. The monthly mean sea level generally rises in Summer to Autumn, and falls in Winter to Spring and its range is from 20 cm to 50 cm. The variation of monthly mean sea level is of annual type, having one maximum and one minimum. The semi-range of annual components is 10.5 cm at Pusan and increases to the north in the west coast, to 20.8 cm at Inchon. It's phase is, on the whole, similar for the entire coast with about 210 (middle of August), except at Inchon, 200 . The variation of monthly mean sea level is mainly isostatic, or caused by those of sea water density and atmospheric pressure. Especially, the steric effect is predominant on the south- east coast around Pusan. However, in shallow long bays and estuaries on the west coast, the river runoff effect as well as local wind effect is also considerable. Magnitudes of annual variations at each stations are not constant, but widely variable from year to year. On the east and south coast, especially at Ulneungdo and Pusan the variations are large, which seem to be connected with the shifting of main current axes or current patterns in the offing.

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Effect of Deep Sea Water on Phase I, Phase II and Ornithine Decarboxylase. (Phase I, phase II 효소 및 ornithine decarboxylase에 미치는 해양심층수의 영향)

  • Shon, Yun-Hee;Kim, Mee-Kyung;Jang, Jung-Sun;Jung, Eun-Jung;Nam, Kyung-Soo
    • Journal of Life Science
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    • v.18 no.3
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    • pp.381-386
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    • 2008
  • Deep sea water was tested for cancer chemopreventive activity by measuring the activities of ${\beta}-$ naphthoflavone $({\beta}-NF)-induced$ cytochrome P 450 1A2 (CYP 1A2), quinone reductase (QR) and glutathione-S-transferase (GST), glutathione (GSH) levels, and ornithine decarboxylase (ODC) activity. The in vitro incubation of rat liver microsome with deep sea water (a hardness range of $100{\sim}1,000$) showed a hardness-dependent inhibition of CYP 1A2 activity. QR and GST activities were induced about $1.1{\sim}1.2$ fold with the treatment of deep sea water in murine hepatoma Hepa 1clc7 cells. In addition GSH levels were increased $1.3{\sim}1.4$ fold in a hardness range of $100{\sim}1,000$. The deep sea water showed 20.3 and 35.0% inhibition of 12-O- tetradecanoylphorbol-13-a-cetate (TPA)-induced ODC activity at hardness 800 and 1,000, respectively. Therefore, deep sea water is worth further investigation with respect to cancer chemoprevention or therapy.

Study on the Effect of the Sound-Deadening Paint on the Inside Running Noise in Railway Vehicles (제진도료가 전동차 실내소음에 미치는 영향에 관한 연구)

  • Woo, Kwang-Je
    • Proceedings of the KSR Conference
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    • 2009.05a
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    • pp.702-706
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    • 2009
  • Internal running noise of a vehicle running in open field is the summation of air borne noise and structure-borne noise. In this paper vibration damping characteristics of carbody are investigated to see the effect of sound-deadening paint on the internal running noise. By using SEA method, vibration levels of complete train with and without sound-deadening paint are estimated and structure borne noise levels are estimated.

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Barotropic Shelf Waves Generated By Longshore Wind Stress

  • Lie, Heung-Jae
    • 한국해양학회지
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    • v.16 no.2
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    • pp.99-107
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    • 1981
  • A partial differential equation for the adjusted sea level, obtained from the long wave equations in shallow water, is reduced to a simpler one by the use of physically reasonable approximations based on the observations. The similar equation for the stream function indicates that shelf waves are generated by the longshore wind stress. This indication is in good agreement with the high correlation between the adjusted sea levels and the longshore wind stress. From the dispersion relationship and the boundary conditions, there exist a countable infinite number of modes which satisfy a first-order wave equations. The adjusted sea level for a given wind stress can easily be calculated by utilizing the convolution and the Fourier transformation. Some detailed solutions are presented here for sinusoidal and exponential wind stress.

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