• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.2
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• pp.37-46
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• 2018

Present research is to evaluate and improve the sealing performance of the duct cap assembly for the ice dispensers through structural analysis. The nonlinear contact problems to check the sealing performance were analyzed using ANSYS software. The results of the analyses related to the sealing performance: the displacement distribution, the contact condition between the cap-silicon and the case, and the pressure distribution on the contact surface, were examined and discussed. Based on the results of the existing design of the duct cap assembly, two cases of the design modifications to improve the sealing performance were introduced. By examining the results of the two cases, a final design improvement plan was proposed and analyzed. It is shown that the sealing performance of the proposed final design is much more favorable than the existing design. The method of structural analysis and design improvement of the duct cap assembly presented in this paper will help improve the sealing performance of the ice dispenser duct caps.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.672-680
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• 2018

The opening angle of the duct cap assembly during the operation of a refrigerator ice dispenser was evaluated by transient structural analysis, and an improved design to maximize the opening angle was obtained. The opening angle of the existing design was found to be 78% of the upper limit. Several design modifications were proposed and analyzed to examine the effects of the design factors on the opening angle. As a result of the design modifications, the opening angle was improved by changing the lever material to a material with a high elastic modulus, moving the position of the support to the motor side, or increasing the lever shaft diameter. Considering the manufacturing cost of the new design, the design modification changing only the lever material was found to be the best because it does not require a change in the structure of the ice dispenser case. In conclusion, the opening angle can be improved by up to 95% of the upper limit value if the lever material is changed to an aluminum alloy. The methods and results presented in this study were found to be of great help in designing the duct cap assembly structure to facilitate the discharge of ice.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.6
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• pp.474-481
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• 2018

This paper is to compare by numerical analysis the flow characteristics and propulsion performance of stern with the shape change of K-duct, a pre-swirl duct developed by Korea Research Institute of Ships & Ocean Engineering (KRISO). First, the characteristics of the propeller and the resistance and self-propulsion before and after the attachment of the K-duct to the ship were verified and the validity of the calculation method was confirmed by comparing this result with the model test results. After that, resistance and self-propulsion calculations were performed by the same numerical method when the K-duct was changed into five different shapes. The efficiency of the other five cases was compared using the delivery horsepower in the model scale and the flow characteristics of the stern were analyzed as the velocity and pressure distributions in the area between the duct end and the propeller plane. For the computation, STAR-CCM +, a general-purpose flow analysis program, was used and the Reynolds Averaged Navier-Stokes (RANS) equations were applied. Rigid Body Motion (RBM) method was used for the propeller rotating motion and SST $k-{\omega}$ turbulence model was applied for the turbulence model. As a result, the tangential velocity of the propeller inflow changed according to the position angle change of the stator, and the pressure of the propeller hub and the cap changes. This regulated the propeller hub vortex. It was confirmed that the vortex of the portion where the fixed blade and the duct meet was reduced by blunt change.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.1-7
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• 2015

The environmental regulations for CO2 emissions from the ship have been established recently, and fuel oil price has been increased continuously. In order to overcome these circumstances, Energy Saving Devices (ESDs) have been developed continuously to reduce the fuel oil consumption and improve the propulsive efficiency. This paper describes the trial performance of PBCF (Propeller Boss Cap Fins), SCHNEEKLUTH duct, Asymmetric rudder bulb and Mewis duct applied to handy-size bulk carriers. As a result, SCHNEEKLUTH duct is more effective than other energy saving devices at the reducing the fuel oil consumption and the improvement of the propulsive efficiency. In addition, it is confirmed that SCHNEEKLUTH duct is really effective in the vibration of the deck house. And the fuel oil consumption can also be reduced through main engine de-rating.

• Journal of Life Science
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• v.8 no.5
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• pp.479-485
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• 1998

The induction of nephric duct from Xenopus presumptive ectoderm(animal cap) was studied and the high-dose ef-fect of IGF-1 was investigated. Activin A induce various organs from cultured animal cap explants and the effects are time and dose-dependent. On the induction of nephric duct, the combined-dose of activin A and retinoic acid was very efficient method in reference study. In present study, we used IGF-1 as well as activin A as a combined growth factor. The concentration ranges of growth factors were activin A l00ng/ml an IGF-1 0-500ng/m1. Explants were cultured in combined solution for 3days to the normal embryo arrives at st. 43. In general, when the explant was cultured in high concentration(l00ng/ml) of activin A, it was destroyed, however, nephric duct and other tis-sues were differentiated by adding IGF-1. In addition, eye induction by adding IGF-1 500ng/ml to activin A 1- 100 ng/ml solution was studied. The low concentration of activin A(1ng/ml) have blood-like cell inducing effect and the explant was balloon-shaped, however, the high dose combination with IGF-1 extended the range of eye inductive concentration of activin A.

• CELLMED
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• v.1 no.1
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• pp.5.1-5.3
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• 2011

Molecular events that cause tumor formation enhance a number of HOX genes, called switch genes, coding for RNApolymeraseII transcription factors. Thus, in tumor cells, RNApolymeraseII is more active than in other somatic cells. Amanita phalloides contains amanitin which inhibits RNApolymeraseII. Partial inhibition with amanitin influences tumor cell - but not normal cell - activity. To widen the treatment spectrum, dilutions of Amanita phalloides, containing amanitin, are applied to a patient with mammary duct cancer. For monitoring tumormarkers, different doses of amanitin are applied. The former duplication time of tumor growth represented three months; however within a period of 18 months the patient can be stabilized without further growth of the tumor. There are also no severe symptoms, no liver damage and no continuous erythrocyte deprivation. This new principle of tumor therapy shows high potential to provide a medical treatment.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.178-185
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• 2023

This study was described the microscopic anatomy of male reproductive organs and spermatophore necessary for understanding the reproductive ecology of the long arm octopus Octopus minor. The long arm octopus was a species that has sexual dimorphism that can distinguish between sex based on the presence of hectocotylus. Male reproductive organs consisted of testis, primary spermatic duct, spermatic gland, secondary spermatic duct, spermatophoric gland and spermatophoric sac. Histologically, the testis was testicular tubule type and male germ cells showed a layered arrangement. The primary spermatic duct was a tube connecting the testis and spermatic gland, and consisted with epithelial layer and connective tissue. The spermatic gland was located between the primary and secondary spermatic duct, and the epithelial layer was composed of epithelial cells and mucous cells. Mucous cells reacted blue in the AB-PAS (pH 2.5) reaction and purple in the AF-AB (pH 2.5) reaction. The secondary spermatic duct was a short tube connecting spermatic gland and spermatophoric gland, and folds were developed in lumen. The spermatophoric gland consisted of numerous tubular glands and secretory cells had eosinophilic granules. The spermatophoric sac was shape of pouch, folds were developed in lumen, and vacuolar secretory cells were present in the epithelial layer. The spermatophore was 83.5 mm long and consisted of cap thread in anterior portion, ejaculatory apparatus and cement body in medial portion, sperm mass in posterior portion.

• Journal of Life Science
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• v.9 no.5
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• pp.504-509
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• 1999

The trend of organogenesis in Xenopus presumptive ectoderm was studied by combined dose of activin A and IGF-1(insulin-like growth factor-1). In reference study of Asashima and his colleagues, the inductive patterns of various organs were reported with activin, the potent mesoderm inducing factor. In present study, the inducing pattern was cleared with combined-dose of concentration 1-100 ng/ml activin A and IGF-1. In addition, the result from single treatment of activin A was compared with former study. As a result, eye was differentiated in 5-20% of explants at 10 and 50 ng/ml concentrative combination of activin A. Otic vesicle was appeared in the entire concentrative combination of IGF-1. Pronephric duct was induced 19-38% of explants at the concentration of activin A 100 ng/ml by adding IGF-1. The comparison of single treatment of activin A was showed some difference in dose-dependent inducing pattern.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1221-1232
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• 2011

We investigated the toxic effects of difenoconazole on the development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of difenoconazole (0-30 ${\mu}M$). $LC_{100}$ for difenoconazole was 30 ${\mu}M$, and the $LC_{50}$ determined by probit analysis was 27.19 ${\mu}M$. Exposure to difenoconazole concentrations ${\geq}$5 ${\mu}M$ resulted in 10 different types of severe external malformation. Histological examinations revealed dysplasia of the eye, heart, liver, somatic muscle, and swelling of the pronephric ducts. The tissue-specific toxic effects were investigated with an animal cap assay. Blood cells were normally induced at a high frequency by mSCF and activin A. However, the induction of blood cells was strongly inhibited by the addition of difenoconazole. Electron micrographs of tested embryos showed the degeneration of somatic muscle and the shrinkage of microvilli on pronephric duct. The gene expression of cultivated animal cap explants was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). It revealed that the expression of the blood-specific marker(${\beta}$-globin II) and muscle-specific marker (XMA) were more strongly inhibited than the neural-specific marker(XEn2) by the addition of difenoconazole.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.6
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• pp.722-733
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• 1999

The wall pressure fluctuations of a turbulent boundary layer over a flat plate have been investigated in an anechoic wind tunnel facility. The anechoic wind tunnel consists of acoustically-lined duct, muffler, and splitter-type silencer for noise suppression and vanes for reducing head losses involved. To improve spectra characteristics in high frequency range, a 1/8" pressure-type microphone sensor, which has a pin-holed cap of various diameters, was employed in this experiment. It was shown that the pin-holed microphone sensor with a dimensionless diameter $d^+$ of 7.1 resolved the high frequency pressure fluctuations most effectively among ones with various pin-hole diameters. The measured wall pressure spectra in terms of three types of scaling parameters were in good agreement with other experimental and numerical results. The pressure events of high amplitude were found to contribute to total fluctuating pressure energies in the turbulent boundary layer significantly and supposed to radiate to the far-field effectively.