• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.233-240
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• 1989

This experiment was carried out to select of heterokaryon based on the different buoyant densities of protoplasts. Protoplats were isolated from cultured cells (calli) of Nicotiana tobacum(cv. BY4) and from mesophyll cells of N. glauca. The two types of protoplats were fractionated by centrifugation in an iso-osmotic (770 mOs/kg. H2O) density gradients condition. Major difference in the buoyant density exists between two types of protoplasts isolated from different cells. The mesophyll protoplasts were fractionated in the higher gradient interphases than that of callus protoplasts. The two types of fractionated protoplasts were fused with 40% polyethylene glycol (PEG), and the protoplasts treated with PEG were separated by centrifugation in the same density gradients condition. The heterokaryons were fractionated in the intermediate density gradients.

• Korean Journal of Veterinary Research
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• v.32 no.4
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• pp.585-595
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• 1992

We have investigated the characteristics of encephalomyocarditis(EMC) virus isolated in Korea. The CPE, buoyant density, polypeptide profile and the size of RNA of EMC virus were examined. The granulation, pyknosis and necrosis were observed from 30 to 48 hour's post inoculation of the virus into baby hamster kidney and lung cells. The buoyant density was 1.30 and $1.35g/m{\ell}$. Three different polypeptides, 26Kd, 32Kd, and 34Kd in size, were observed and the size of viral RNA was 7.7Kb.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.191-197
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• 2002

The prediction of the dynamic behaviors of buoyant water discharges into a large volume of water bodies, the flows of water accompanying the density differences due to temperature differences and sometimes also to salinity differences, have attracted great concern over several decades. Heated water surface discharges from power plants and freshwater discharges in estuaries are typical examples of the buoyant flows. (omitted)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.1
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• pp.11-22
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• 1987

A plane buoyant jet discharged vertically upward into a crossflow is analyzed by numerical solution of the governing equations of continuity, momentum and constituent transport. The turbulent transport is modelled by the Prandtl's mixing length theory. In the numerical solution procedure, the governing equations are transformed by stream function and vorticity transport, non-dimensionalyzed by discharge velocity, slot width, and parameters representing flow characteristics, and solved by Gauss-Seidel iteration method with successive underrelaxation. The numerical experiments were performed for the region of established flow of buoyant jet in the range of discharge densimetric Froude number of 4 to 32 and in the range of velocity ratio of 8 to 15, which is the ratio of discharge velocity to crossflow velocity. Variations of velocities and temperatures, flow patterns and vorticity patterns of receiving water due to buoyant jet were investigated. Also investigated are the effects of velocity ratio and discharge densimetric Froude number on the trajectories of buoyant jet. Computed are velocities, temperatures and local densimetric Froude numbers along the trajectory of the buoyant jet. Spreading rate and dispersion ratio were analyzed in terms of discharge densimetric Froude number, local densimetric Froude number and distance from the source along the jet trajectory. It was noted that the similarity law holds in both the profiles of velocity and temperatures across the jet trajectory and the integral type analysis of Gaussian distribution is applicable.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.229-238
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• 2016

This study aims to investigate egg quality and amino acid composition of buoyant and non-buoyant eggs and evaluate egg quality of sevenband grouper, Epinephelus septemfasciatus. Amino acid analysis of eggs was conducted to investigate what elements were necessary for the survival and good quality of egg depending on farming condition and different diet. We analyzed amino acid from buoyant eggs and non-buoyant eggs, farming conditions (tank and sea cage), and different dietary conditions (formulated feed, formulated feed+raw fish-based moist pellets, and raw fish-based moist pellets). Egg quality was the best in a sea cage and when raw fish-based moist pellets (MP) were fed. In addition, egg quality with formulated and MP was better than that with formulated feed. As a result of amino acid analysis of eggs, buoyant eggs were containing more free amino acid than non-buoyant eggs. Also, eggs with MP were containing more free amino acid than those with formulated feed and MP. Eggs with mixed formulated feed and MP were containing more free amino acid than formulated feed. In conclusion, amino acid was helpful to improve egg quality, and egg quality can be controlled by farming conditions and feed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.7 no.3
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• pp.248-256
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• 1995

The numerical study on the surface buoyant jets has remained of requiring more intensive investigation for problems due to the treatments of free surface, Reynolds stress/flux terms in turbulent flow and especially buoyancy effects on the turbulent fluctuation. etc. The verification of predicted results from the numerical study continues in the qualitative study. because of the lack of experimental data, which seems to be due to the difficulties in measuring the turbulent fluctuations in concentration or temperature fields. In this study, the computer program of Algebraic Stress Model has been developed to investigate the behaviours of two-dimensional surface buoyant jets with free surface boundary condition. The computational results are compared with published experimental data. By comparing these results with experimental data. it is found that this model can predict fairly well the flow characteristics of two-dimensional surface buoyant jets in the momentum-dominant region and buovancy-dominant region. Especially, it is proved that this model can predict the flow characteristics reasonably in buoyancy-dominant region stably stratified due to buoyancy effect.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.6
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• pp.466-473
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• 2011

The buoyancy and initial momentum fluxes make near-field dominated by buoyant jet when thermal discharge releases underwater. In order to estimate prediction capabilities of those near-field phenomena, non-hydrostatic RANS applied CFD(Computational Fluid Dynamic) model was used. Condition of model was composed based on past laboratory experiments. Numerical simulations carried out for the horizontal buoyant jet in the stagnant flow and vertical buoyant jet into crossflow. The results of simulation are compared with the terms of trajectory and dilution rate of laboratory experiments and analytic model(CorJET) results. CFD model showed a good agreement with them. CFD model can be appropriate for assessment of submerged thermal discharge effect because CFD model can resolve the limitations of near-field analytic model and far-field quasi 3D hydrodynamic model. The accuracy and capability of the CFD model is reviewed in this study. If the computational efficiency get improved, CFD model can be widely applied for simulation of transport and diffusion of submerged thermal discharge.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.1
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• pp.1-8
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• 2005

Transition of momentum-controlling hydrogen jet to buoyant jet is experimentally investigated in order to develop a prediction model for the moving trajectory of hydrogen leaked from hydrogen devices. In the experiments, room-temperature helium, that has a similar density to the hydrogen leaked from high pressure tank, is horizontally injected through a 4mm tube and its moving trajectory is visualized by the shadowgraph method. The moving trajectories are found to be parabolic, thereby exhibiting increasing influence of the buoyancy. In analyzing the experimental results, the vertical movement is assumed to be controlled by the buoyancy while the horizontal movement is controlled by the air entrainment caused by the initial momentum. The resealing based on this assumption yields a single curve fitting to the all experimental results.

• Water Engineering Research
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• v.3 no.2
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• pp.93-111
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• 2002

In this paper, mixing characteristics and dilution of the merging buoyant discharges from array of multiple jets has been extensively studied in the hydraulic model experiments. New equations for dilution, which include the merging effects correctly, were derived. Experiments were constructed in a 20-m long, 4.9-m wide and 0.6-m deep flume, and the model diffuser was manufactured to indicate the typical characteristics of the existing ocean wastewater outfall in South Korea. Buoyant discharge from the diffuser was reproduced using heated water. Water temperature was measured using CC-Type thermocouple sensors, which were connected to a 40-channel data logger. Experimental results show that merging between ports in a particular riser is dependent upon the discharge densimetric Froude number, whereas merging between two ports which are facing each other at 90$\circ$ at the adjacent risers is dependent upon the discharge densimetric Froude number and distance from the port and port spacing. Centerline dilution increase with distance from the port outlet until two plumes has merged. However, after merging occurs, increase of the centerline dilution almost stops. Further distance from the position where merging occurs, centerline dilution increases again.

• New & Renewable Energy
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• v.7 no.4
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• pp.37-41
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• 2011

This paper presents a Combined solar-wave Power Generation (CPG) concept that the CPG unit is maintained as buoyant at the level of sea water and it is also supported by a submerged tunnel, with the aim of supplying emergency electric power during the station blackout events of nuclear power plants. The CPG concept has been motivated from the 2011 Fukushima-Daiichi Accidents due to the loss of both offsite AC power and emergency diesel power caused by natural hazards such as earthquake and tsunami. The CPG is conceptualized by applying different types and different sites for emergency power generation, in order to reduce common cause failures of emergency power suppliers due to natural hazards. Thus, the CPG can provide a new mean for supplying emergency electric power during station blackout events of nuclear power plants. For this application, the CPG requirements are described with a typical configuration at the ocean side of a submerged tunnel.