• 한국재료학회지
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• 제4권1호
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• pp.24-30
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• 1994

가공열처리한 7075Al합금을 $170^{\circ}C$에서 퇴화처리하여도 GP대는 완전히 분해되지 않았으며 초기의경도저하는 부분적인 GP대의 분해에 기인하고 $\mu '$의 생성으로 강도는 증가하다가 $\mu '$의 성장 및 $\mu$의 생성으로 강도는 다시 저하한다. 퇴화처리시 경도 곡선의 극소점이나 2차 피크점(극대점)에서 RRA처리한 시편의 응력부식 특성은 T6재에 비하여 상당히 개선되며 강도의 저하를 수반하지 않는다. 또한 저온인 $170^{\circ}C$에서 퇴화처리시 기지조직의 변화가 크지 않아 퇴화처리시 경도곡도의 극소점과 2차 피크점에서의 특성차이는 거의 없었다.

• 산업기술연구
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• 제7권
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• pp.49-58
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• 1987

To investigate the effect of the Retrogression and Reaging (RRA) treatment on the strength and the stress corrosion cracking in AA 7039 the measurement of hardness, tensile properties and the time to failure in a constant rate method were measured. Transmission electron microscope was used to examine the microstructural changes within graln and grain boundary. The results show that the RRA treatment of the T6 condition results in a significant increase in the time to failure without sacrifying the original T6 strength. It is believed that high density and even distribution of precipitates in RRA condition were observed within grain so that the RRA condition could have similar strength to the T6 condition. The presence of fine dispersion of semicohernt ${\eta}^{\prime}$ transition phase is also believed to contribute to that effect. Examination of the grain boundary microstructure shows that the RRA treatments increases significantly the average size of the grain boundary preciptates. It is suggested that the benificial effect of the RRA treatment on the susceptibility to SCC be due to the increase in the size of grain boundary precipitates obtained during the retrogression treatment.

• Ecology and Resilient Infrastructure
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• 제3권3호
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• pp.207-211
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• 2016

본 연구는 충적하천의 식생이입 현상, 즉 경관생태적으로 하천이 화이트리버에서 그린리버로 변하는 현상을 원인 별로 구분하고, 구분된 각각의 유형을 설명하고, 앞으로의 연구방향을 제시하는 것이다. 문헌연구와 과거 필자들이 제한된 범위에서 시행한 관련 국내 연구성과에 의하면 사주 상 하천식생 이입과 퇴행의 필요/충분 조건은 기계적 교란 (하상소류력), 토양습윤(지하수위, 지형, 하상재료 구성, 강수 등), 침수기간, 극단적 기후, 그리고 영양염류의 유입 등이다. 본 연구에서 사주 상 하천식생 이입과 퇴행의 원인 별 유형으로서 부분적으로 입증된 가설인 봄철 강우양상 변화로 인한 비조절하천에서 홍수 저감과 하천에 영양물질 유입증가 유형을 추가하였다. 하천식생 이입과 퇴행 현상을 과학적으로 더 규명하고 실제 이용가능한 하천식생모형의 개발을 위해서는 화이트리버가 그린리버로 바뀌는 현상의 전국적인 현황조사, 가설의 검증과 세분화를 통한 원인 별 유형 정립, 동적 하천식생 모델링 기법 개발, 변화에 따른 적응관리 등에 대해 연구가 필요하다.

• Corrosion Science and Technology
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• 제15권4호
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• pp.159-165
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• 2016

An attempt has been made to understand the influence of retrogression and re-aging (RRA) on the exfoliation corrosion behaviour of AA 7085 alloy in comparison with the peak aged condition (PA). Immersion tests using ASTM G34 and studies involving electrochemical impedance spectroscopy showed that the RRA treated alloy provided higher resistance to exfoliation corrosion than the PA treated alloy. The improved resistance was attributed to the enhanced Cu content and the discontinuous nature of the grain boundary precipitate, which was revealed through transmission electron microscopy.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 추계학술발표강연 및 논문개요집
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• pp.36-36
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• 1999

• 대한물리치료과학회지
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• 제11권4호
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• pp.11-19
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• 2004

Muscle stiffness, pain discomfort in daily activities are cardinal symtoms on arthritis. To reduce these symtoms, a nonequivalent one-group pre & posttest experiment was carried out at a rural community health post area in kwangju province during eight weeks(from 25th of January to 20th of March, 2002) The subjects were sixteen old (60-80) with osteoarthritis. And to reduce the level of pain, discomfort in daily living and to increase that of life satisfaction, 25-30minutes of muscle-joint exercise followed by 25-30minutes of local heat therapy were done three times a week. The total experimental period extended at 12 weeks and the total 36 times it executed 1. The retrogression characteristic osteoarthritis elderly with local heat and a muscle joint exercise was the telegram which it receives and after receiving, the score of the paindaily activity function appeared to the lead, there was a difference which considers statistically, this constriction was supported.(Z=4.947, p<0.0001) 2. The retrogression characteristic osteoarthritis elderly with local heat and a muscle joint exercise was the telegram which it receives and after receiving, the score of daily activity function appeared lowly, there was a difference which considers statistically, this construction was supported.(Z=2.7226, p<0.0279) 3. The retrogression characteristic osteoarthritis elderly with local heat and a muscle joint exercise was the telegram which it receives and after receiving, there was not a difference where the quality of life considers statistically, this construction was rejected.(Z=-1.2087, p>0.2171)

• 동의신경정신과학회지
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• 제13권2호
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• pp.173-194
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• 2002

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old age. In the future AD will be the largest problem in public health service. From old times, Much medicines have been used for treatment of dementia, but there is no medicine having obvious effect. AD is one of brain retrogression disease. So We studied on herbal medicine that have a relation of brain retrogression. From old times, In Oriental Medicine, Rhizoma Acori Graminei has been used for disease in relation to brain retrogression. We studied on the effects of anti-Alzheimer in pCT105-induced neuroblastoma cell lines by Rhizoma Acori Graminei extract As the result of this study, In RAG group, the apoptosis in the nervous system is inhibited, the repair against the degerneration of Neuroblastoma cells by CT105 expression is promoted. These results indicate that RAG possess strong inhibitory effect of apoptosis in the nervous system and repair effect against the degeneration of Neuroblastoma cells by CT105 expression.

• 동의신경정신과학회지
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• 제14권2호
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• pp.95-105
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• 2003

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old age. In the future AD will be the largest problem in public health service. From old times, Much medicines have been used for treatment of dementia, but there is no medicine having obvious effect. AD is one of brain retrogression disease. So We studied on herbal medicine that have a relation of brain retrogression. From old times, In Oriental Medicine, Radix Polygalae and Rhizoma Acori Graminei have been used for disease in relation to brain retrogression. We studied of anti-Alzheimer effect on CT105-induced neuroblastoma cell lines by Radix Polygalae(RP) and Rhizoma Acori Graminei(RAG) water extract. As the result of this study, In RP and RAG group, the apoptosis in the nervous system is inhibited, the repair against the degeneration of Neuroblastoma cells by CT105 expression is induced. These results indicate that In RP and RAG, RAG possess the strongest in inhibitory effect of apoptosis in the nervous system and repair effect against the degeneration of Neuroblastoma cells by CT105 expression.

• Asian-Australasian Journal of Animal Sciences
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• 제19권4호
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• pp.514-520
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• 2006

An abandoned mandarin orange orchard in southwestern Japan was set-stocked by Japanese Black cows at two stocking rates (1.0 and 2.0 animals/ha), and vegetation dynamics and diet selection by cattle were monitored for two years, in an effort to obtain information on effective use of abandoned agricultural fields for low-cost animal production and environmental conservation. Two dominant species at the commencement of grazing, kudzu (Pueraria lobata Ohwi) and tall goldenrod (Solidago altissima L.), showed different responses to grazing during the two years; the composition of kudzu decreased, contrasting with that of tall goldenrod which increased at both stocking rates. This was caused by high preference for kudzu and avoidance or low preference for tall goldenrod by cattle. Retrogression of vegetation due to cattle disturbances occurred at both stocking rates, with the high stocking rate leading to a lower degree of succession than the low stocking rate. It was shown that cattle grazing, particularly at a high stocking rate, was effective in the management of vegetation of an abandoned orchard.

• 동의신경정신과학회지
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• 제15권1호
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• pp.65-76
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• 2004

Alzheimer's disease(AD) is a geriatric dementia that is widespread in old ages. In the future AD will be the largest problem in public health service. From old times, much medicines have been used for treatment of dementia, but there is no medicine having obvious effects. AD is one of brain retrogression disease. So we studied on herbal medicine that have a relation for brain retrogression. From old times, in oriental medicine, senile disease such as dementia and AD is treated by exclusion of Tan(痰). But Vascular Dementia(VsD) is due to YuXue(瘀血). So in recent studies, Hua Xue Hua Yu(活血化瘀) medicine is used for precautionary and medical treatment. We studied on the effects for anti-Alzheimer in pCT105-induced neuroblastoma cell lines by Hyeolbuchukeo-tang(HCT). As the results of this study, in HCT group, the apoptosis in the nervous system is inhibited, the repair against the degeneration of Neuroblastoma cells by CT105 expression is promoted. These results indicate that HCT possess strong inhibitory effect of apoptosis in the nervous system and repair effect against the degeneration of neuroblastoma cells by CT105 expression.