• Asian-Australasian Journal of Animal Sciences
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• v.15 no.9
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• pp.1341-1347
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• 2002

An experiment was conducted to determine effects of oral administration of $Diakur^{TM}$ (an additive of glucose and electrolytes for young calves) on growth performance and some physiological responses in male broilers reared in a high temperature. A 2 by 3 factorial arrangement test of 2 temperatures (24 and $36^{\circ}C$) and 3 levels of oral administration of the glucose and electrolytes additive, $Diakur^{TM}$, (0, 150 and 300 mg/day/100 gBW) were applied in the experiment. Male broiler chicks (2 weeks of age) were assigned to six groups and received dietary and temperature treatments for 7 days. The additive of glucose and electrolytes was suspended with water and intubated into crop twice a day (08:00 and 17:00). Oral administration of the additive prevented decreases in food intake and growth rates in broilers due to exposure of the hot environment. Oral administration of the additive also improved a lowered electrolyte ($Na^+$ + $K^+$ - $Cl^-$) balance in plasma, low mitogenic response of blood mononuclear cell and an increase in glucose concentration due to exposure to the high environmental temperature. Oral administration of the additive increased rectal temperature regardless of environmental temperatures. On the other hand, blood pH, $pCO_2$ and $HCO_3$ - concentration, and plasma creatine kinase activity were not affected by the oral administration. The results suggested that oral administration of the glucose and electrolytes additive, $Diakur^{TM}$ during heat stress did not only prevent decrease in growth performance, but also normalized some physiological and immunological responses in male broilers.

• Korean Journal of Materials Research
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• v.30 no.10
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• pp.522-532
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• 2020

Conductive polymer composites with high electrical and mechanical properties are in demand for bipolar plates of phosphoric acid fuel cells (PAFC). In this study, composites based on natural graphite/fluorinated ethylene propylene (FEP) and different ratios of carbon black are mixed and hot formed into bars. The overall content of natural graphite is replaced by carbon black (0.2 wt% to 3.0 wt%). It is found that the addition of carbon black reduces electrical resistivity and density. The density of composite materials added with carbon black 3.0 wt% is 2.168 g/㎤, which is 0.017 g/㎤ less than that of non-additive composites. In-plane electrical resistivity is 7.68 μΩm and through-plane electrical resistivity is 27.66 μΩm. Compared with non-additive composites, in-plane electrical resistivity decreases by 95.7 % and through-plane decreases by 95.9 %. Also, the bending strength is about 30 % improved when carbon black is added at 2.0 wt% compared to non-additive cases. The decrease of electrical resistivity of composites is estimated to stem from the carbon black, which is a conductive material located between melted FEP and acts a path for electrons; the increasing mechanical properties are estimated to result from carbon black filling up pores in the composites.

• Mycobiology
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• v.47 no.4
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• pp.494-505
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• 2019

In this study, the antioxidant, anti-xanthine oxidase, anti-melanogenic and anti-wrinkle effects of methanol (ME) and hot water (HE) extracts from the fruiting bodies of Phellinus vaninii were investigated. The 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging activity of 2.0 mg/mL HE (95.38%) was comparable to that of butylated hydroxytoluene (96.97%), the reference standard. The hydroxyl radical scavenging activities of ME (98.19%) and HE (97.55%) were higher than that of butylated hydroxytoluene (92.66%) at 2.0 mg/mL. Neither ME nor HE was cytotoxic to murine melanoma B16-F10 cells at 25-750 ㎍/mL. Although the xanthine oxidase (XO) inhibitory effects of ME and HE were significantly lower than that of allopurinol, the values were higher than 84 percent. The in vitro tyrosinase inhibitory activities of ME and HE were comparable to kojic acid at 2.0 mg/mL. The cellular tyrosinase and melanin synthetic activities of ME and HE on B16-F10 melanoma cells at 500 ㎍/mL were higher than arbutin, indicating that the inhibitory effects of arbutin on the tyrosinase and melanin synthesis were higher than those of ME and HE. The collagenase inhibitory activity of HE was comparable to EGCG at 2.0 mg/mL, however, the elastase inhibitory activity of ME and HE was lower than EGCG at the concentration tested. The study results demonstrated that the fruiting bodies of Ph. vaninii possessed good antioxidant, anti-xanthine oxidase, cell-free anti-tyrosinase, cellular anti-tyrosinase, anti-collagenase, and moderate anti-elastase activities, which might be used for the development of novel anti-gout, skin-whitening, and skin anti-wrinkle agents.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.188-195
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• 2002

To investigate the degradation of mechanical properties induced mainly by neutron irradiation, the tensile tests were conducted from room temperature to 300\\`c using the irradiated and the unirradiated Zr-2.5Nb pressure tube materials. The irradiated longitudinal and transverse specimens were collected from the coolant inlet, middle, and outlet parts of M-11 tube which had been operated in Wolsung CANDU Unit-1 and exposed to different operating temperatures and irradiation fluences. The different tensile behavior was characterized not by the fluences of irradiation but by the tensile loading direction. The transverse specimen showed the higher strength and lower elongation than those of the longitudinal one. It was believed that these phenomena resulted from the microstructure anisotropy caused by the extrusion process. The increased strength hardening and decreased elongation embrittlement of the irradiated material were compard to those of the unirradiated one. While the tensile strength of the inlet was higher than that of the outlet, the elongation of the inlet was lower than that of outlet. Considering the operation condition, it was proposed that the operating temperature could be a more effective parameter than the irradiation fluence for long-time life. Through the TEM observation, it was found that while the a-type dislocation density was increased, the c-type dislocation was not changed in the irradiated. The fact that the higher dislocation density was sequentially distributed over the inlet, the middle, and the outlet parts was consistent with the distribution of the tensile strength.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.614-620
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• 2003

KAERI has developed DUPIC nuclear fuel with the refabrication of spent PWR fuel discharged from domestic nuclear power plant by a dry process at M6 hot-cell in IMEF To verify the performance of DUPIC nuclear fuel, irradiation test at the operating conditions of commercial power plant is essential. Since the HANARO research reactor of KAERI does not have fuel test loop(FTL) for irradiating nuclear fuel under high temperature and high pressure conditions, DUPIC fuel cannot be irradiated in the FTL of HANARO. In the 13-th PRM among Korea, Canada, USA and IAEA, AECL proposed that KAERI fabricated DUPIC fuel can be irradiated in the FTL of the NRU research reactor without charge of neutrons. The transportation quantity of DUPIC fuel to Canada is 10 elements(about 6kg). This transportation package is classified as the 7-th class according to "recommendation on the transport of dangerous goods" made by the United Nations. In case of air shipment, until now, there is no proper air transportation cask for DUPIC fuel. In case of sea transportation is possible but requires very high cost.high cost.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.388-394
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• 2003

To handle the high level radioactive materials such a spent fuel, the master-slave manipulators (MSM) are widely used as a remote handling device in nuclear facilities such as the hot cell with sealed and shielded space. In this paper, the Digital Mockup which simulates the remote operation of the Advanced Conditioning Process(ACP) is developed. Also, the workspace and the motion of the slave manipulator, as well as, the remote operation task should be analyzed. The process equipment of ACP and Maintenance/Handling Device are drawn in 3D CAD models using IGRIP. Modeling device of manipulator is assigned with various mobile attributes such as a relative position, kinematics constraints, and a range of mobility, The 3D graphic simulator using the external input device of space ball displays the movement of manipulator. To connect the external input device to the graphic simulator, the interface program of external input device with 6 DOF is deigned using the Low Level Tele-operation Interface(LLTI). The experimental result shows that the developed simulation system gives much-improved human interface characteristics and shows satisfactory response characteristics in terms of synchronization speed. This should be useful for the development of work's education system in the virtual environment.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.162-167
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• 2003

The pool $(3m{\times}6m{\times}10m)$ in Irradiated Materials Examination Facility is usually used for the purpose of taking the specimen out of cask loaded into the pool, and carrying in/out the specimen to/from the hot cell. Always, it must be cared for the water into the pool to be fine condition because all operation are worked with the naked eye during taking an irradiated materials out of the cask and plunging them in the bucket-elevator. In the aspects of the radioactive contamination control, remained substances in the water must be controlled so that the amount of substances are to be lower than the standard amount prescribed by RCA Korea Activity in a part of radioactive contamination control. This paper describes a behavior of the quality of water and the radioactive contamination of pool water for working of pool water purging system and contamination diffusion distribution bahavior of each specimens carried in/out.

• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.316-324
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• 2002

To investigate the mutational spectrum of laccase (Lac) genes (lac -A and lac -B) involved in degrading lignin which is the recalcitrant cell wall polymer, the genes of the Pleurotus ostreatus mutants induced by gamma ray radiation were amplified by PCR and were cloned. All partial lac-A genes of 4 mutants (PO-6, -7, -14 and -15) consisted of 1763 base pairs due to the deletion of two bases (491-nt and 492-nt) and addition of one base (875-nt) in 1764 base pairs of lac -A gene of PO-1. Totally 36 mutational hot spots were detected and 32 positions were mutated in all of those 4 mutants simultaneously. These mutations were predominantly A : T -> G : C transitions (40%). Putative amino acid sequences of lac -A genes of mutants have one simultaneous mutated residue (from Thr-44 to Ala-44). The 1764 bp of partial lac -B gene was cloned only in PO -5 mutant and contained 19 mutated bases. These mutations were predominantly G : C->A : T transitions (45%). Lac-B protein of PO-5 has two mutated residues of Glu-290 and His-363 from Ala-290 and Phe-363, respectively. The hyper-mutational positions were concentrated in specific regions of between 50-nt and 900-nt in lac genes. These results suggested that the mutational hotspots responded to gamma radiation could be in some genes, at least lac -A and lac -B of p. ostreatus.

• Journal of Korea Foundry Society
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• v.15 no.3
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• pp.252-261
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• 1995

The purposes of this study were to investigate the microstructural changes in alloy ribbons of Al-Fe-Mo-Si quarternary system at $450{\sim}500^{\circ}C$, and to study the coarsening mechanism of fine precipitates. Using the hot stage in TEM, in situ microstructural changes in Al-4Fe-0.5Mo-1.5Si alloy ribbon and Al-8Fe-2Mo-1.5Si alloy ribbon have been examined successively up to 60 hours at $450^{\circ}C$ and $500^{\circ}C$. Cell structure in zone B of Al-4Fe-0.5Mo-1.5Si alloy ribbon was observed to collapse even in 10 minutes by in-situ heating at $450^{\circ}C$ and the size of precipitates in zone B increased twice in 60 hours. The precipitates in zone A of Al-4Fe-0.5Mo-1.5Si alloy ribbon showed slower coarsening rate than those in zone B by in-situ heating at $450^{\circ}C$. The precipitates in zone A of Al-8Fe-2Mo-1.5Si alloy ribbon increased 50% by in-situ heating at $500^{\circ}C$ in 50 hours compared to the initial precipitates while any microstructual change in zone B was not observed by in-situ heating at $500^{\circ}C$ up to 50 hours. Only the precipitates in zone A of Al-4Fe-0.5Mo-1.5Si alloy ribbon satisfied $r^3{\propto}t$ relationship of coarsening mechanism.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.35-38
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• 2002

In this paper, the characteristics of channel hot electron (CHE) injection for the write operation in a NOR-type SONOS flash memory with common source line were investigated. The thicknesses of he tunnel oxide, the memory nitride， and the blocking oxide layers for the gate insulator of the fabricated SONOS devices were $34{\AA}$, $73{\AA}$, and $34{\AA}$, respectively. The SONOS devices compared to floating gate devices have many advantages, which are a simpler cell structure, compatibility with conventional logic CMOS process and a superior scalability. For these reasons, the introduction of SONOS device has stimulated. In the conventional SONOS devices, Modified Folwer-Nordheim (MFN) tunneling and CHE injection for writing require high voltages, which are typically in the range of 9 V to 15 V. However CHE injection in our devices was achieved with the single power supply of 5 V. To demonstrate CHE injection, substrate current (Isub) and one-shot programming curve were investigated. The memory window of about 3.2 V and the write speed of $100{\mu}s$ were obtained. Also, the disturbance and drain turn-on leakage during CHE injection were not affected in the SONOS array. These results show that CHE injection can be achieved with a low voltage and single power supply, and applied for the high speed program of the SONOS memory devices.