• Resources Recycling
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• v.25 no.4
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• pp.54-59
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• 2016

EAF processed slag which contains about 20 ~ 35 weight percent FetO is poured to slag pot and cooled. If we recover Fe from molten slag by the reduction, we will improve steel yield rate and reduce slag quantity poured from the furnace. Usually, carbon is used as a reductant and slag foaming agent in the EAF process. In this experiment, after melt the metal in induction furnace and then add slag with carbon and Al dross powder as a reductant, we investigated the reduction of FetO from slag and change of Phophorus content. As the result, when we use Al dross as a reductant, recovery rate is two times more than carbon. Phosphorus pick up is less than 50ppm with reduction of EAF slag.

• Journal of Welding and Joining
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• v.26 no.2
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• pp.43-49
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• 2008

Fatigue cracks due to thermal stratification or corrosion in pipelines of nuclear power plants can cause serious problems on reactor cooling system. Therefore, the development of an integrated technology including fabrication of standard specimens and their practical usage is needed to enhance the reliability of nondestructive testing. The test material was austenitic STS 304, which is used as pipelines in the Reactor Coolant System of a nuclear power plants. The best condition for fabrication of thermal fatigue cracks at the notch plate was selected using the thermal stress analysis of ANSYS. The specimen was installed from the tensile tester and underwent continuos tension loads of 51,000N. Then, after the specimen was heated to $450^{\circ}C$ for 1 minute using HF induction heater, it was cooled to $20^{\circ}C$ in 1 minute using a mixture of dry ice and water. The initial crack was generated at 17,000 cycles, 560 hours later (1cycle/2min.) and the depth of the thermal fatigue crack reached about 40% of the thickness of the specimen at 22,000 cycles. As a results of optical microscope and SEM analysis, it is confirmed that fabricated thermal fatigue cracks have the same characteristics as real fatigue cracks in nuclear power plants. The crack shape and size were identified.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.12
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• pp.1887-1897
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• 2001

Korea Atomic Energy Research Institute (KAERI) launched an intermediate scale steam explosion experiment named "Test for Real Corium Interaction with water (TROI)" using reactor material to investigate whether the molten reactor material would lead to energetic steam explosion when interacted wish cold water at low pressure. The melt-water interaction experiment is performed in a pressure vessel with the multi-dimensional fuel and water pool geometry. The novel concept of cold crucible technology, where powder of the reactor material in a water-cooled cafe is heated by high frequency induction, is firstly implemented for the generation of molten fuel. In this paper, the lest facility and cold crucible technology are introduced and the results or the first series of tests were discussed. The 5 kg of molten ZrO$_2$jet was poured into the 67cm deep water pool at 30 ∼ 95 $\^{C}$. Either spontaneous steam explosions or quenching was observed. The morphology of debris and pressure wave profiles clearly indicate the differences between the two cases.

• Clinical and Experimental Reproductive Medicine
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• v.17 no.2
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• pp.167-172
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• 1990

This study was carried out to clarify the effects of various kinds of cryoprotectants which were frequently used in freezing embryos of domestic animals on the survival of frozen-thawed mouse embryos. Mouse embryos were collected by hyperstimulation induction of ICR mouse. The samples were slowly cooled ($l^{\circ}C/min$) to temperatures between $-7^{\circ}C$ and $-30^{circ}C$ before direct transfer to liquid nitrogen ($-196^{\circ}C$) and thawed rapidly ($-500^{\circ}C$/min). As cryoprotectants, Glycerol, DMSO, Ethylene glycol and Propylene glycol were used and applied each 2 cell, 8 cell, morula in embryo stage. After normal mouse embryos developed to blastocyst by in vitro culture, we observed recovery rate and developing rate of embryos at thawing. The results obtained in these experiments were as follows : 1. The in vitro development rate from the frozen-thawed 2 cell embryos to the blastocyst were 67.7% in ethylene glycol, 65.7% in Propylene glycol, 55.2% in glycerol and 50.0% in DMSO respectively. 2. The in vitro development rate from the frozen-thawed 8 cell embryos to the blastocyst were 83.6% in DMSO, 75.7% in glycerol, 52.2% in propylene glycol respectively. 3. The in vitro development rate from the frozen-thawed morula to the blastocyst were 84.2% in glycerol, 80.0% in DMSO, 66.6% in propylene glycol and 55.2% in ethylene glycol respectively.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.867-881
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• 1998

The studies were carried out to investigate the phygiological changes in deep hypothermia in rabbits. Sixty rabbits were continuously cooled with femoral arterio-venous bypass circulation to rectal temperatures of $34.0{\pm}0.3^{\circ}C$(mild hypothermia), $30.0{\pm}0.3^{\circ}C$(moderate hypothermia), and $25.0{\pm}0.3^{\circ}C$(deep hypothermia). The results obtained in these experiments were summarized as follows : In mild, moderate, and deep hypothermia, MAP, HR, RR, pH, $pCO_2$, $pO_2$, $Na^+$, $K^+$, HCT, PLT, glucose, L-lactate, BUN, and creatinine were analyzed. During hypothermia, a statistically significant decrease of MAP occurred between $30^{\circ}C$ and early $25^{\circ}C$(Start) of rectal temperature while significant increases occurred between baseline($38.7^{\circ}C$) and $30^{\circ}C$. Significant decreases of HR and RR were observed in the rabbits, particularly those changes appeared to similar patterns in proportion to hypothermia. Significant decreases of pH occurred between $34^{\circ}C$ and $25^{\circ}C$, and significant increases of $pO_2$ and $pCO_2$ were observed continuously in the hypothermic rabbits. The hypothermia had no significant effect on blood $Na^+$ and serum creatinine. Blood $K^+$ significantly decreased from $3.1{\pm}0.5$(baseline) to $2.6{\pm}0.6mmol/l$($34^{\circ}C$) with the hypothermia for about 30 minutes, and significantly increased from $2.4{\pm}0.6$($25^{\circ}C$(S)) to $2.7{\pm}0.5mmol/l$($25^{\circ}C$(E)) with the hypothermia for 2 hrs. HCT significantly increased to $34^{\circ}C$, thereafter, continuously increased to $25^{\circ}C$(Start, End). PLT increased to $34^{\circ}C$, thereafter, continuously decreased to $25^{\circ}C$(Start, End). Also PLT decreased significantly from 414.3($30^{\circ}C$) to $308.8{\times}103/mm^3$($25^{\circ}C$, Start). Significant increases of blood glucose and L-lactate occurred between $30^{\circ}C$ and $25^{\circ}C$ (Start, End). Slight increase of serum BUN continuously appeared with the hypothermia. These results, such as characteristic changes of the significant decrease of pH and PLT at $34^{\circ}C$, the significant decrease of MAP at $30^{\circ}C$, and the significant increase of glucose and l-lactate at $30^{\circ}C$, suggest that homeostasis of rabbits to hypothermia rapidly decreases at $34{\sim}30^{\circ}C$ of rectal temperature. Therefore, we suggest that, during the period with the rapidly decreased homeostasis, the very carefully control and treatment need to recover hypothermic animals under the circumstances of the various hypothermic experiments and emergency medicine.