• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2613-2617
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• 2010

Chloroprene is a chlorine substituent of 1,3-butadiene. Butadiene rubber (BR) and chloroprene rubber (CR) composites were thermally aged at 60, 70, 80, and $90^{\circ}C$ for 2 - 185 days in a convection oven and changes of the crosslink densities by the accelerated thermal aging were investigated. The crosslink densities increased as the aging time elapsed and as the aging temperature became higher. Degrees of the crosslink density changes of the BR composite were on the whole larger than those of the CR one except the short-term thermal aging at 60 and $70^{\circ}C$. The crosslink densities abnormally increased after themal aging at high temperatures for a long time. Activation energies for the crosslink density changes of the rubber composites tended to increase with increase of the aging time and the variation showed a local minimum. The activation energies of the CR composite were lower than those of the BR one. The experimental results were explained with a role of ligand of chlorine atom of CR in a zinc complex, steric hindrance by chlorine atom of CR, and oxidation of rubber chain.

• Food Science of Animal Resources
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• v.37 no.6
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• pp.823-832
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• 2017

The objective of this study was to determine the effect of aging method (dry or wet) and time (20 d or 40 d) on physical, chemical, and sensory properties of two different muscles (top round and shank) from steers (n=12) using an electronic tongue (ET). Moisture content was not affected by muscle types and aging method (p>0.05). Shear force of dry aged beef was significantly decreased compared to that of wet aged beef. Most fatty acids of dry aged beef were significantly lower than those of wet aged beef. Dry aged shank muscles had more abundant free amino acids than top round muscles. Dry-aging process enhanced tastes such as umami and saltiness compared to wet-aging process according to ET results. Dry-aging process could enhance the instrumental tenderness and umami taste of beef. In addition, the taste of shank muscle was more affected by dry-aging process than that of round muscle.

• Environmental and Resource Economics Review
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• v.21 no.2
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• pp.341-369
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• 2012

Population aging has been one of the serious problems in Korea. Aging can affect social and economic features including energy consumption. This paper analyzed how population aging makes an effect on residential electricity demand. Yearly data from 1965 to 2010 were collected. The long and short-run demands for residential electricity were estimated with respect to Korean aging index. The results show that population aging reduces residential electricity demands in the short run significantly, but the effect decreases in the long run. However, population aging still negatively affects residential electricity consumption in long run. If population keep aging as Korean government expected, then the residential electricity demand per capita will grow less than 3%.

• Journal of muscle and joint health
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• v.26 no.3
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• pp.175-183
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• 2019

Purpose: This is a descriptive research examining the relationships between aging anxiety, perceived level of successful aging, and preparation for aging as well as factors influencing preparation for aging. Methods: Subjects of this study were 221 women aged between 40 and 59 years residing in area J. Data were collected from October 27, 2017 to November 9, 2017, using a structured questionnaire. The collected data were analyzed using the statistical program SPSS/WIN 24.0. Results: Regression analysis revaled that factors having a significant effect on the preparation for aging of the subjects were age, perceived health status, exercise, leisure activity, aging anxiety, and perception of successful aging. The total explanatory power was 42.3%. Conclusion: Based on the results of this study, it was found that aging anxiety and successful aging influenced the preparation for aging of middle-aged women. Therefore, it is necessary to develop a nursing intervention that properly manage aging anxiety and improves successful aging, in order to encourage middle-aged women to actively prepare for their later lives.

• 한국노년학
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• v.41 no.4
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• pp.527-546
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• 2021

This study examined the effect of past acceptance on suicidal ideation in older adults and verified double mediation effects of attitude to aging and depression. The responses of 329 aged 65 years or older who participate in senior welfare centers in Seoul and Gyeonggi-do were used. As an analysis method, the double mediation effect was confirmed through serial multiple mediation model verification using the SPSS PROCESS macro program. The followings are the results of the study. First, the past acceptance had a significant effect on the aging attitude, the aging attitude on the depression, and the depression on the suicidal ideation, but the direct effect of past acceptance on the suicidal ideation was not significant. Second, double mediation effects of attitude to aging and depression were significant in the relationship between past acceptance and suicidal ideation. Based on these results, practical and policy interventions to prevent suicide in old age were suggested.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.610-616
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• 2014

In this study, we investigated the precipitation behavior of the R-phase precipitated at the initial stage of aging and its effect on the pitting corrosion of 25%Cr-7%Ni-4%Mo super duplex stainless steel. The R-phase in super duplex stainless steel was mainly precipitated at the interface of ferrite/austenite phases and inside of the ferrite phase during the initial stage of aging, and it was transformed into the ${\sigma}$-phase with an increase in aging time. The ferrite phase was decomposed into a new austenite phase and ${\sigma}$-phase. The R phase was an intermetallic compound, which represented a lower Ni and higher Mo than the matrix, and also had a higher Mo and Cr concentration than the ${\sigma}$ phase. With an increasing aging time, the pitting potential $E_p$ was increased slowly by the precipitation of the R-phase, and it was then steeply decreased by the precipitation of the ${\sigma}$-phase. The R-phase was decreased the pitting potential, but its effect was smaller than effect of ${\sigma}$-phase.

• Proceedings of the SCSK Conference
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• 2003.09a
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• pp.291-312
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• 2003

Reactive oxygen species are capable of damaging biomolecules such as lipids, proteins, and DNA, which can not only lead to various diseases, but also oxidative damage resulting aging. In our previous study, Cercis chinensis (Leguminosae) showed a potent antioxidant activity. Nineteen compounds were isolated through antioxidant activity-guided fractionation. The C. chinensis extract and some of the constituents exhibited a potent antioxidant activity on the free radicals and lipid peroxidation and a notable protective effect on the t-BuOOH induced oxidative damage. In vivo test of skin damage induced by UVB irradiation, the extract of C. chinensis and a constituent, piceatannol, exhibited a significant protective effect. The life-span of the HEK-N/F cells were extended by 1.21-2.12 fold as a result of the continuous administration of 3 $\mu\textrm{g}$/ml of the C. chinensis extract and the active constituents compared to that of the control. These observations were attributed to the inhibitory effect of the C. chinensis extract and its constituents on the age-dependent shortening of the telomere. Thus, C. chinensis was demonstrated to protect the skin cells against oxidative stress and inhibit thereby the cellular aging, followed by expectation as anti-aging cosmetic ingredient.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.1
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• pp.35-42
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• 2004

This study was carried out to examinate the effect of aging period on chromatic, chemical and organoleptic characteristics, and to evaluate of optimum aging period for each grade in burley leaf tobacco. The leaf tobaccos were produced in 2000, and threshed, redried and packed in carton box under the current methods. Four grades of processed leaf(A3T, B1T, C1W and D3W) were stored during 24 months (May 10, 2001 to April 31, 2003) in warehouse of Chungju Leaf Tobacco Processing Factory. The leaf tobaccos were sampled at three month intervals for analysis of chromatic, chemical and organoleptic properties. pH values of four grades, and Yellow(b) of A3T and BIT were also significantly decreased during the aging. Filling values, tar, nicotine and CO contents of tobacco smoke, and puff number of cigarettes were not significantly changed during the aging. Positive correlation coefficients were significantly observed between irritation of the calculated attributes from contents of volatile oil components in leaf tobacco and that of the panel sensory attributes. The ratio of maximum change in irritation attribute was larger than that in taste attribute during aging. The calculated irritations of 18～24 months aging for A3T and B1T were significantly lower than zero-aging, while those of C1W and D3W were not significant among aging periods. The panel irritations of 12～15 months aging for four grades were low tendency. The results suggest that decrease of aging period for thin leaf from 21～24 to 12～15 months may be beneficial to save storage cost in burley tobacco.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.23-29
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• 1984

Nowdays, the high strength aluminum alloys are broadly used for structural purpose, but the practical strengthening method by aging treatment are not much available. So that, in this study, in order to investigate the effect of aging treatment for strengthening on the fracture characteristics of the domestic high strength Al alloy (A2024BE), the variations of the aging temperature and time were taken after solution treatment. By microstructural examination, and by SEM fractographs of the fractures, the effects of aging temperature and time were investigated, considering on the fracture behaviour. The results obtained are as follows: 1) It was confirmed by microstructural investigation that the aging temperature of $190^{\circ}C$ and the aging time of 12hours were optimal to get more sound microstructure with distribution of uniform precipitation. 2) By step aging treatment, the proper aging time for obtaining the similar microstructure without any microstructural defects could be shortened in half the normal aging time. 3)By examining the SEM fractographs of the fracture surface, it was found that, regardless of the aging treatment time and temperature, all were intergranular ductile fractures, but the aging treatment at $190^{\circ}C$ for 12 hours resulted in dimple-type-transgranular and intergranular-ductile-frature.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.23 no.2
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• pp.177-185
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• 2016

Purpose: In this study, we sought to identify the impact of aging anxiety and successful aging on the personality traits of elderly. Method: Subjects were 108 elderly persons aged more than 65 years. Data collected from June to November 2015 were analyzed using descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression. Results: With regard to the mean scores of personality traits, conscientiousness yielded the highest score, and neuroticism the lowest. The mean score on aging anxiety was below average, and that on successful aging was above average. Aging anxiety differed significantly according to age, present job, economic status, and health status. Successful aging differed significantly according to having a spouse, economic status, and health status. Significant correlations were found between anxiety and conscientiousness, extraversion, and neuroticism, and between successful aging and conscientiousness, agreeableness, extraversion, openness, and neuroticism. Conscientiousness and neuroticism had an effect on aging anxiety (23.2%), whereas conscientiousness, agreeableness, extraversion, openness, and neuroticism affected aging anxiety (45.3%). Conclusion: These findings indicate that personality traits reduce aging anxiety and lead to successful aging among elderly.