• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.94-96
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• 1997

A mathematical model (hybrid arc model) for arc behaviour in an $SF_6$ puffer gas-blast circuit-breaker has been developed. It has adopted the advantages of integral method and differential method. The method has been applied to model puffer circuit breaker of Noeske et al and good agreement of critical RRRV(Ratio of Rise of Recovery Voltage) has been obtained. Axial or radial distributions of temperature, electric field and arc radius are also presented and analyzed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.4
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• pp.233-239
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• 2000

There are many difficult problems in analyzing the gas flow in puffer type circuit breaker such as complex geometry, moving boundary, shock wave and so on. To predict the interruption performance accurately, these should be considered in the simulation. In this paper, the analysis procedure of the cold gas flow in the circuit breaker is presented. Euler equation is solved by FVFLIC method which is an explicit time difference scheme for an unsteady flow computation. Moving boundaries are treated with a cell elimination-addition technique. The pressure and density in front of piston are calculated from the rate of the cell volume change. The presented method is applied to the real circuit breaker model and the pressure in front of the piston is good agreement with the experimental one.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05a
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• pp.68-73
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• 2000

An arc model based on the N-S equations modified by adding an energy source term to take account of the arc is developed and solved using Taylor-Galerkin FEM. The numerical method is applied to the simulation of the interruption process of a puffer type GCB. Moving boundary conditions of the arc chamber during operation is taken into account. The thermal interruption capability of an actual puffer type GCB will be predicted and compared with that of the measured result.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.467-469
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• 2006

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.292-298
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• 2007

The whitespotted puffer, Arothron hispidus (Linnaeus, 1785), of the family Tetraodontidae were collected by an Koheung Peninsula in July 2003. This species is color of the body; covered with black and the spots on the body is white color. white. Dorsal fin rays 11~12; pectoral fin rays 17; anal fin rays 10~11; caudal fin rays 5+6=11; vertebrae 8+10=18. Measurement for five specimen (195.0~265.3 mm SL) in hundredths of standard length; head length 36.8%; pectoral fin length 13.4%; dorsal fin length 11.6%; caudal peduncle length 15.0%; caudal peduncle depth 13.7%. This is ventral postclavicle, exposed in hundredths of length 6.14~6.75; verterbrae 18; dorsal pterygiophores formula $7{\ast}1231$; number of dorsal pterygiophores 7.

• Journal of fish pathology
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• v.23 no.1
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• pp.107-112
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• 2010

Parasitism of Pseudocaligus sp. in wild grass puffer Takifugu niphobles in the coast of Yeosu in spring, 2007 was identified. The preadult and adult stages of Pseudocaligus sp. were observed, which consisted of cephalothorax, genital segment and abdomen. Lunules were present on the anterior margin of the frontal plate. In order to develop the treatment method, we examined the effects of formalin and fresh water on the parasite. The Pseudocaligus sp. were detached from the host fish by bathing at concentrations of 50 to 400 ppm formalin within 60 min, but 57% was exterminated to fresh water for 90 min.

• Journal of fish pathology
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• v.20 no.2
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• pp.129-137
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• 2007

Skeletal deformity in hatchery-reared river puffer (Takifugu obscurus) fingerlings occurred. The vertebral abnormality was recognized with naked eyes 80 days after hatching. Affected fish had a good appetite but no clinical signs were found except the vertebral abnormality. As more than 90% of the hatchery-reared fish exhibited vertebral abnormality, the fingerlings could not be used for commercial seeds any more. Morphological changes in the vertebrate and the swim bladder were observed with a soft X-ray. Histopathological changes on the caudal muscle around the deformed vertebrae, gill, and spleen were also examined to clarify the cause of the deformity. Spinal curvature occurred between vertebrae 10 and 12, but any malfunction of the swim bladder was not found. The diameters of the muscle fibers around the deformed vertebrae were much smaller and more irregular than those in normal fish, and the gabs between the fiber bundles were greatly enlarged. No evidence of inflammation response was found in the muscle layer. In the hatchery, feed was putting at the position of water inflow, which might attract the fingerings to move toward the feed in spite of incomplete development of their caudal muscle fibers. From these results, it is suggested that the high speed of water current in rearing aquaria might be associated with the development of vertebral abnormality.

• Ocean and Polar Research
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• v.39 no.1
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• pp.1-11
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• 2017

The aim of this study was to determine the physiological response and the applicable concentration ranges of anesthetic clove oil and anesthetic lidocaine-HCl, and to investigate the synergistic effect of a mixture of these two anesthetics on the in grass puffer (Takifugu niphobles). The anesthesia times decreased and the recovery times increased with increasing concentrations of clove oil and lidocaine-HCl. Applicable concentration ranges for long-term transportation requiring more than 1 hour were 2 ppm for clove oil and 50 ppm for lidocaine-HCl. With mixtures of the two anesthetics, the anesthesia time decreased as the admixture concentration of clove oil and lidocaine-HCl increased. Anesthesia times of experimental groups with the combined anesthetics were shorter than those with the same concentrations of clove oil or lidocaine-HCl alone. Plasma cortisol concentrations were highest at 6 hours in all experimental groups anesthetized with the mixture of clove oil and lidocaine-HCl, while all groups with clove oil or lidocaine-HCl alone had the highest plasma cortisol concentrations at 12 hours. Plasma glucose concentrations were highest at 12 hours in experimental groups anesthetized with the mixture of clove oil and lidocaine-HCl, while groups with clove oil or lidocaine-HCl alone had the highest plasma glucose at 24 hours. The results of this study provide basic information about anesthetics and the synergistic effect of mixtures of anesthetics in this fish species. This information should be useful for aquaculturists who require methods for safe and easy fish handling, and for transporters who require that minimal stress is imposed on fish during transport.

• Journal of fish pathology
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• v.19 no.2
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• pp.99-108
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• 2006

Diseased tiger puffer (Takijugu rubripes) showed anorexia and severe anemia in the gills. In wet mount preparations Heterobothrium sp. with 4 sets of clamps on the opisthohaptor attached to the gill filaments of the diseased fish. From the drum-shaped filter for filtration of the culturing water and the sediment of aquarium held the diseased fish in the laboratory, their eggs forming long strings through connection of the bipolar filaments could be easily collected. The parasites with 4 pairs of clamps on the opisthohaptor were 2.38mm in length and 0.71 mm in width, but had no isthmus which was separated the opisthohapor from the body proper. The parasites could be easily distinguished from Heterobothrium tetrodonis and H. okamotoi in the absence of distinct isthmus, and resembled H. yamagutii described from the gills of Takifugu xanthopterus in Japan. Their eggs were yellowish spindle in shape and 180-200 x 5-6 Iffil in size, which were pointed at both ends. The eggs were linked to adjacent egg shells like a string of beads by the filaments. Onchomiracidia, ciliated larvae spawned from the eggs were 133 Iffil (120-146 Iffil) x 751ffil (68-80 Iffil) in size. The length of the ciliates was 12 Iffil in the anterior part of the larvae and 14 Iffil in the posterior part. Round or leaf-shaped young parasites attached on the secondary gill lamellae. There was a tendency that most of round smaller parasites without an opisthohaptor were found in the middle part of the gill lamellae while leaf-shaped larger ones with a opisthohaptor attached on the distal part of the gill filaments. Each clamp of mature parasites grasped one secondary gill filament which resulted in bending of the filaments and hyperplasia of the epithelium and mucous cells. In the branchial cavity around the pseudobranch, mature parasites grasped the adjacent ones by means of the clamps, and the epithelia of the branchial cavity around the parasites showed severe irregular hyperplasia and erosion with strongly PAS-positive mucous cells.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.1126-1131
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• 2003

In this study, we investigated the effects of detoxified puffer liver (PL) oil on fatigue, hepatotoxicity and hyperlipidemia. There are no toxicities in both raw and purified PL oil. The test of swimming time was extended in detoxified PL oil pretreated group compared to the non-treated group. When rats treated with PL oil, the hepatic injuries induced by carbon tetrachloride or DL-galactosamine were reduced. The increased serum triglyceride and total cholesterol by poloxamer-407 were lowered by treating with PL oil remarkably. Also the bleeding time of hyperlipidemic animals was extended and plasma clotting time was delayed by PL oil.