• Journal of Korean Port Research
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• v.13 no.2
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• pp.419-426
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• 1999

It is essential for port planning, coastal zone management and environmental impact study to analyze the variation of current and water quality due to the development of water area and discharged water from estuary barrage and basin etc. Mokpo sea area downstreams from a long river and two large basins, the Yongsan river and Yongam-Kumho basins discharging much of water through water gates for the purpose of flood control and prohibition of salt intrusion to the inland fresh water area. In this study, the numerical calculations were carried out for the analysis of diffusion characteristics due to discharging operation, adapting the results of tidal current simulation ADI methord is applied to the governing equation for the movement of sea water and diffusion and 6-point method to the advection terms of diffusion equation. As the results of this study, it is known that the discharging operation causes increasing and/or decreasing of current velocity and enlarging and/or depressing of pollutant diffusion limits depending on the distance from the discharging gates and the mode of discharging operation. To utilize these result, the linked gate operation and the method increasing exchange of sea water must be considered.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.253-261
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• 1999

It is essential for port planning, coastal zone management and environmental impact study to analyze the variation of current and water quality due to the development of water area and discharged water from the estuary barrage and basin, etc. Mokpo sea area has downstream from a long river and two large basins, the Yongsan river and Yongam-Kumho basins, discharging much of water through water gates for the purpose of flood and prohibition of salt intrusion to the inland fresh water area. In this study, the numerical calculation were carried out for the analysis of diffusion characteristics due to discharging operation, adopting the results of tidal current simulation. ADI method is applied to the governing equation for the movement of sea water and diffusion and 6-point method to the advection terms of diffusion equation. As the results of this study, it is known that the discharging operation causes increasing and/or decreasing of current velocity and enlarging and/or depressing of pollutant diffusion limits depending on the distance from the discharging gates and the modes of discharging operation. To utilize these result, the linked gate operation and the method increasing exchange of sea water must be considered.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.2
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• pp.105-118
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• 2000

Anchored measurements (12.5 hr) of suspended sediment concentration and other hydrodynamic parameters were carried out at two stations located at the entrance to Hampyung Bay in summer (August 1999). Tidal variations in water temperature and salinity were in the range of 26.0-27.9$^{\circ}C$ and 30.9-31.5, respectively, indicating exchange offshore and offshore water mass. Active tidal mixing processes at the entrance appear to destroy the otherwise vertical stratification in temperature and salinity in spite of strong solar heating in summer. On the contrary, suspended sediment concentrations show a marked stratification with increasing concentrations toward bottom layer. Clastic particles in suspended sediments consist mostly of very fine to fine silt (4-16 ${\mu}$m) with a poorly-sorted value of 14.7-25.9 ${\mu}$m. However, at slack time with less turbulent energy, flocs larger than 40 ${\mu}$m are formed by cohesion and inter-collision of particles, resulting in a higher settling velocity. Strong ebb-dominated and weak flood dominated tidal currents, in the southwestern and the northeastern part, respectively, result in a seaward residual flow of -10${\sim}$-20 cm $s^{-1}$ at station H1 and a bayward residual flow less than 5.0 cm $s^{-1}$ at station H2. However, mean concentration of suspended sediments at station H1 is higher at flood (95.0-144.1 mg $1^{-1}$) than in ebb (75.8-120.9 mg $1^{-1}$). On the contrary, at the station H2, the trend is reversed with higher concentration at the ebb (84.7-158.4 mg $1^{-1}$) than that at the flood (53.0-107.9 mg $1^{-1}$). As a result, seaward net suspended sediment fluxes ($f_{s}$) are calculated to be -1.7 ${\sim}$-$15.610^{3}$ kg $m^{-2}$ $s^{-1}$ through the whole water column. However, the stations H1 and H2 show definitely different values of the flux with higher ones in the former than in the latter. Alternatively, depth-integrated net suspended sediment loads ($\c{Q}_{s}$) for one tidal cycle are also toward the offshore with ranges of 0.37${\times}$$10^{3}$ kg $m^{-1}$ and 0.21${\times}$$10^{3}$ kg $m^{-1}$, at station H1 and H2, respectively. This seaward transport of suspended sediment in summer suggests that summer-time erosion in the Hampyung muddy tidal flats is a rather exceptional phenomenon compared to the general deposition reported for many other tidal flats on the west coast of Korea.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.766-772
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• 2000

Background : Pressure rise time (PRT) is the time in which the ventilator aclieves the set airway pressure in pressure-targeted modes, such as pressure control ventilation (PCV). With varying PRT, in principle, the peak inspiratory flow rate of the ventilator also varies. And if PRT is set to a shorter duration, the effective duration of target pressure level would be prolonged, which in turn would increase inspiratory tidal volume(Vti) and mean airway pressure (Pmean). We also postulated that the increase in Vti with shortening of PRT may relate inversely to the patients' basal airway resistance. Methods : In 13 paralyzed patients on PCV (pressure control 18$\pm$9.5 cm $H_2O$ $FIO_2\;0.6\pm0.3$, PEEP 5$\pm$3 cm $H_2O$, f 20/min, I : E1 : 2) with Servo 300 (Siemens-Elema, Solna, Sweden) from various causes of respiratory failure, PRT of 10 %, 5 % and 0 % were randomly applied. At 30 min of each PRT trial, peak inspiratory flow (PIF, L/sec), Vti (ml), Pmean (cm $H_2O$) and ABGA were determined. Results : At PRT 10%, 5%, and 0%, PIF were 0.69$\pm$0.13, 0.77$\pm$0.19, 0.83$\pm$0.22, respectively (p<0.001). Vti were 425$\pm$94, 439$\pm$101, 456$\pm$106, respectively (p<0.001), and Pmean were 11.2$\pm$3.7, 12.0$\pm$3.7, 12.5$\pm$3.8, respectively (p<0.001). pH were 7.40$\pm$0.08, 7.40$\pm$0.92, 7.41$\pm$0.96, respectively (p=0.00) ; $PaCO_2$ (mm Hg) were 47.4$\pm$15.8, 47.2 $\pm$15.7, 44.6$\pm$16.2, respectively (p=0.004) ; $PAO_2-PaO_2$ (mm Hg) were 220$\pm$98, 224$\pm$95, 227$\pm$94, respectively (p=0.004) ; and $V_n/V_T$ as determined by ($PaCO_2-P_E-CO_2$)/$PaCO_2$ were 0.67$\pm$0.07, 0.67$\pm$0.08, 0.66$\pm$0.08, respectively (p=0.007). The correlation between airway resistance and change of Vti from PRT 10% to 0% were r= -0.243 (p=0.498). Conclusion : Shortening of pressure rise timee during PCV was associated with increased tidal volume, increased mean airway pressure and lower $PaCO_2$.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.279-285
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• 2005

One-lung ventilation (OLV) is the isolation and selective ventilation of one lung field. OLV allows the collapse of lung lobes on the side of the thoracic surgical approach to facilitate observation of intrathoracic structures and to achieve lung immobility. OLV be achieved by endotracheal intubation with double lumen tubes or bronchial blockers. In this study, cardiopulmonary consequences of two-lung ventilation (TLV), OLV and Re-TLV (TLV after OLV) were evaluated in 5 dogs. The dogs were anesthetized with mask induction and maintained with isoflurane in oxygen. Tidal volume and respiratory rates were set to maintain end-tidal $CO_2$ at $40{\pm}2mmHg$ during instrumentation. Following instrumentation, the dogs were placed in right lateral recumbency and induced spontaneously respiration state. Effect of TLV on hemodynamic and pulmonary variables were recorded. Then, the left bronchus was obstructed by endotracheal intubation with double lumen endotracheal tube to achieve OLV state and recording was continued. After OLV, double lumen endotracheal tube was extubated, and standard endotracheal tubes was intubated again. In this study, spontaneous OLV caused significant decrease in $PaO_2$, arterial oxygen saturation, mixed-venous oxygen saturation, and increase in $PaCO_2$. Especially, a significant elevation in $PaCO_2$ and respiratory acidosis were remarkable findings. So spontaneous ventilation in OLV affected gas exchange and hemodynamic function.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.3
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• pp.279-287
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• 1993

Daily variation of particulate organic carbon(POC) and some factors controlling its level were examined for a semi-enclosed bay(Wonmun Bay, south coast of Korea), in which a lot of suspended oyster culture farms existed, in September, 1992. Observations were made at hourly interval. In spite of the relatively short survey period, strong short-term variation of POC concentration could be observed. Concentrations of POC were the range of $58{\sim}582{\mu}g/l(average 272{\mu}g/l)$ and their variation pattern was similar to those of chlorophyll a with the range of $0.90{\sim}7.25{\mu}g/l(average 3.35{\mu}g/l)$. The low C/N ratios also suggested that marine microalgae was a major component of POC for Wonmun Bay. Primary production, average $1.97\;gC/m^2/day$, was the main source of POC beacuse the supply of POC via freshwater input and exchange with the outer part of the bay was little. Oyster population also excreted a small amount of POC. About $40\%$ of produced POC was decomposed heterotrophically. Another important cause for the fluctuation of observed POC was tidal cycle. Considerable POC, which amounted $37\%$ of produced POC, was lost from the bay due to flushing by tidal cycle. It was also calculated that about $16\%$ was transported onto the sediment. It seemed that a part of POC was consumed by oyster and other heterotrophs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.201-211
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• 2022

At the center of the Noryang waterway, the Gwangyang bay area (including the Yeosu Strait) is located at the west, and the Jinju bay area (including Gangjin bay and Sacheon bay) is located at the east. Freshwater from several rivers is flowing into the study area. In particula,r the event of flood, great quantities freshwater flow from Seomjingang (Seomjin river) into the Gwangyang bay area and from Gahwacheon (discharge from Namgang Dam) into the Jinju bay. The Gwangyang and Jinju bay are connected to the Noryang waterway. In addition, freshwater from Seomjingang and Gahwacheon also affect through the Noryang waterway. In this study, we elucidated the characteristics of the tidal exchange rate and residence time for dry season and flood season on 50 frequency, considering freshwater from 51 rivers, including Seomjingang and Gahwacheon, using a particle tracking method. We conducted additional experiments to determine the effect of freshwater from Seomjingang and Gahwacheon during flooding. In both the dry season and flood season, the result showed that the particles released from the Gwangyang bay moved to the Jinju bay through the Noryang waterway. However, comparatively small amount of particles moved from the Jinju bay to the Gwangyang bay. Each experimental case, the sea exchange rate was 44.40~67.21% in the Gwangyang bay and 50.37~73.10% in the Jinju bay, and the average residence time was 7.07~15.36days in the Gwangyang bay and 6.45~12.75days in the Jinju bay. Consequently the sea exchange rate increased and the residence time decreased during flooding. A calculation of cross-section water flux over 30 days for 7 internal and 5 external areas, indicated that the main essential flow direction of the water flux was the river outflow water from Seomjingang flow through the Yeosu strait to the outer sea and from Gahwacheon flow through Sacheon bay, Jinju bay and the Daebang waterway to the outer sea.

• Journal of Korea Soil Environment Society
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• v.5 no.3
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• pp.25-33
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• 2001

The study was performed to examine the influence of sea tide on a tideland composition by Saemankeum reclamation and to evaluate a correlation between the characteristics of physical and the pollution level of heavy metals. Also, it was investigated the characteristics of heavy metal adsorption through a batch experiment and applied to adsorption isotherm equations. In the results, the flow of sea tide occurred to accumulation action and had an effect on the content of heavy metals. It suggests that influence factors for the content of heavy metals in the tidal flat be grain size, cation exchange capacity and organic matter content. Adsorption capacity of heavy metals occurs to 90% adsorption rate for injection concentration within 30 minutes. The flow patterns in Saemankeum area will undergo a change for soil size distribution. In result, this soil size changed will effect the adsorption capacity of heavy metals.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.105-110
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• 1988

The study was undertaken to determine the most adequate tidal volume when used volume preset ventilator during anesthesia. The thirty patients were received controlled mechanical ventilation with constant inspiratory pressure of 10cmH2O and respiratory frequency of 12/minute. The results were as follows : 1) The PH was $7.39{\pm}0.01$ and it is within normal limit. 2) The $PaCO_2$ was $34.0{\pm}0.6$ mmHg and it is a slightly hyperventilatory state. 3) The $PaO_2$ was $228.0{\pm}8.2$ mmHg. 4) The Buffer base was $20.7{\pm}0.3mEql$ and it is a slightly buffer base deficient state. From the above results. We concluded that if patients were fully relaxed during general anesthesia, it is desirable to maintain the inspiratory pressure of anesthetic mechanical ventilator to $10cmH_2O$ for adeguate alveolar ventilation.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.275-283
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• 2018

Ischemic stroke can result from blockage of blood vessels, forming fibrin clots in the body and causing irreparable brain damage. Remedial thrombolytic agents or anticoagulants have been studied; however, because the FDA-approved tissue plasminogen activator has low efficacy and side effects, it is necessary to develop safer and more effective treatment candidates. This study aimed at assessing the fibrinolytic and anticoagulation features of a novel serine protease extracted and purified from Diopatra sugokai, a polychaeta that inhabits tidal flats. The purified serine protease was obtained through ammonium sulfate precipitation, affinity chromatography, and ion-exchange chromatography. Its molecular size was identified via SDS-PAGE. To characterize its enzymatic activities, the protease activity at various pH and temperatures, and in the presence of various inhibitors, was measured via azocasein assay. Its fibrinolytic activity and anticoagulant effect were assessed by fibrin zymography, fibrin plate assay, and fibrinogenolytic activity assays. The novel 38 kDa serine protease had strong indirect thrombolytic activity rather than direct activity over broad pH (4-10) and temperature ($37^{\circ}C-70^{\circ}C$) ranges. In addition, the novel serine protease exhibited anticoagulant activity by degrading the ${\alpha}$-, ${\beta}$-, and ${\gamma}$-chains of fibrinogen. In addition, it did not produce cytotoxicity in endothelial cells. Therefore, this newly isolated serine protease is worthy of further investigation as a novel alkaline serine protease for thrombolytic therapy against brain ischemia.