• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.522-527
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• 2002

The microstructure and mechanical properties of friction stir welded OFC plates with 2mm in thickness were examined with the changing welding parameters such as welding speed, rotation speed in this study. The sounding welding conditions was acquired at the optimum welding conditions of the 41mm/min to 61mm/min of welding speed at 1250 rpm of rotation speed. The microstructure of weld zone was divided into four parts such as the base metal region (EM), thermal mechanical affected zone (TMAZ), heat affected zone (HAZ), stir zone (SZ). The grain size in the SZ and the width of weld nugget were increased with increasing welding speed. The hardness profiles of the base metal were distributed about 80HV. The HAZ is a slightly softened region of about 60~75 HV relative to the base metal. The hardness profiles of the SZ were higher than that of base metal. The tensile strength was increased with increasing welding speed. In case increasing rotation speed, tensile strength was decreased. The maximum tensile strength was about 220:MPa which was 110% of joint efficience of that of base metal at 41mm/min of welding speed, 1250rpm of rotation speed.

• 생명과학회지
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• 제13권6호
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• pp.911-916
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• 2003

The effects of Opuntia ficus-indica (OF) administration on the biochemical parameters of function in liver tissue and serum of $CCl_4$ treated rats were investigated. Opuntia ficus-indica (200 mg/kg) was administered into rats intraperitoneally for two weeks. $3.3m\ell$ of $CCl_4$$_4$ (50% $CCl_4$ : Olive oil = 1 : 1) was treated to rats on the 14th day and 15th day and they were operated on 15th day. We examined the antioxidative enzymatic activity by measuring the level of AST (Aspartate aminotransferase), ALT (Alanine aminotransferase), GSH (Glutathione reduced form), GSSG (Glutathione oxidezed form), GPx (GSH-peroxidase), SOD (Superoxide dismutase) and CAT (Catalase) in serum and liver tissue of rats. OFC administered group showed 24.8% of inhibitory effect in AST activity compared to $CCl_4$ -treated abnormal group (CTA). ALT level of OF administered group was decreased by 60.7% to the level of CTA. GSH, GSSG and GPx of OFC administered group were significantly higher than those of CTA group. SOD and CAT in OFC administered group were increased by 28.3% and by 16.9% respectively compared to those of CTA group.

• 대한금속재료학회지
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• 제48권1호
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• pp.77-84
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• 2010

Annealing characteristics of an oxygen free copper (OFC) processed by differential speed rolling (DSR) were investigated in detail. An OFC sample with a thickness of hum was rolled to 35% reduction at ambient temperature without lubrication, varying the differential speed ratio from 1.0:1 to 2.2:1, and then annealed for 0.5h at various temperatures from 100 to $400^{\circ}C$. Different recrystallization behavior was observed depending on the differential speed ratio, especially in the case of annealing at $200^{\circ}C$ Complete recrystallization occurred in the specimens annealed at temperatures above $250^{\circ}C$ regardless of the differential ratios. The hardness distribution in the thickness direction of the rolled OFC sheets varied depending on the differential speed ratios. These annealing characteristics were explained by the magnitude of shear strain introduced during rolling.

• The Journal of Korean Physical Therapy
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• 제35권6호
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• pp.190-194
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• 2023

Purpose: Traumatic brain injury (TBI) refers to brain damage caused by external forces or trauma. TBIs can vary in severity and result from accidents, falls, sports injuries, assaults, or other forms of physical trauma. The prefrontal cortex (PFC) is known have roles in various cognitive functions. We report on a patient with traumatic brain injury who showed prefrontal symptoms after injury of thalamocortical connections between mediodorsal nuclei (MD) of thalamus and PFC. Methods: A 54-year-old, male patient suffered a TBI as a result of a heavy object falling on his head. After onset of TBI, he showed typical symptoms of prefrontal lobe injury, including personality changes, memory impairment, and general cognition problem. The thalamocortical connections between MD and PFC (ventrolateral prefrontal cortex (VLPFC), dorsolateral prefrontal cortex (DLPFC), and obrbitofrontal cortex (OFC)) were reconstructed using diffusion tensor tractography. In terms of fractional anisotropy value, the right thalamocortical connections to the OFC were significantly lower than those of control subjects. Results: The value of mean diffusivity in the right thalamocortical connections to the DLPFC was significantly higher than that of control subjects. By contrast, both VLPFC and left OFC showed significant decrement in the tract volume of thalamocortical connections compared with that of control subjects. Conclusion: We reported on a patient who showed cognitive and neuropsychiatric impairment due to global injury of the thalamocoritcal connections between MD and PFC following TBI.

• 과학과기술
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• 제35권9호통권400호
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• pp.30-31
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• 2002

• 광산업정보
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• 통권63호
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• pp.6-7
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• 2011

• 광산업정보
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• 통권52호
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• pp.18-21
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• 2009

• 광산업정보
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• 통권10호
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• pp.22-26
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• 2002

• 대한치과교정학회:학술대회논문집
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• 대한치과교정학회 2003년도 제36회 학술대회
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• pp.26-26
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• 2003

• 광산업정보
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• 통권16호
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• pp.38-41
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• 2003