• Elastomers and Composites
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• v.54 no.4
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• pp.351-358
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• 2019

To evaluate the aging of a rubber pad in power window switch which is the part of a vehicle, the accelerated thermal aging test of rubber pad material is performed. Finite element analysis was performed using the nonlinear material constants of the rubber pad to calculate the operating force, and the Arrhenius relationship was derived from the aging temperature and time. The aging test was performed at 150, 180, 210, or 240 ℃ for 1 to 60 days. When the operating force of the rubber pad is changed by 10% from the initial value, the service life is expected to be 113 years, which is much longer than the life of the vehicle. This indicates that the aging life of the rubber pad is sufficiently safe and the operating force of the rubber pad during the life of the vehicle (20 years) was decreased by approximately 8.4%. By examining the correlation between the shear elastic modulus and operating force calculated from finite element analysis under each aging test condition, the changes in the operating force of the rubber pad and the shear elastic modulus showed good linear relationship. The aging life could be predicted by the change in shear elastic modulus and a process for predicting the aging life of automotive power window switch rubber pad parts is described herein.

• Nuclear Engineering and Technology
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• v.36 no.5
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• pp.475-484
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• 2004

Extending the lifetime of a nuclear power plant [(hereafter referred to simply as NPP)] is one of the most important concerns in the global nuclear industry. Cables are one of the long-life items that have not been considered for replacement during the design life of a NPP. To extend the cable life beyond the design life, it is first necessary to prove that the design life is too conservative compared with actual aging. Condition monitoring is useful means of evaluating the aging condition of cable. In order to simulate natural aging in a nuclear power plant. a study on accelerated aging must first be conducted. In this paper, evaluations of mechanical aging degradation for a neoprene cable jacket were performed after accelerated aging under tcontinuous and intermittent heating conditions. Contrary to general expectations, intermittent heating to the neoprene cable jacket showed low aging degradation, 50% break-elongation, and 60% indenter modulus, compared with continuous heating. With a plant maintenance period of 1 month after every 12 or 18 months operation, we can easily deduce that the life time of the cable jacket of neoprene can be extended much longer than extimated through the general EQ test. which adopts continuous accelerated aging for determining cable life. Therefore, a systematic approach that considers the actual environment conditions of the nuclear power plant is required for determining cable life.

• Journal of Korean Public Health Nursing
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• v.26 no.2
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• pp.204-214
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• 2012

Purpose: This study was conducted in order to the relationship between life satisfaction, health behaviors, and successful aging and factors associated with successful aging. Methods: Participants in this study included 159 elders living in one city. Data on life satisfaction (Choi's Life Satisfaction Scale for Korean elderly, 1984), health behaviors (Choi & Kim's Health Behaviors Scale for Korean elderly, 1997), and successful aging (Kim & Shin's Successful Aging Scale for Korean elderly, 2005) were collected by trained interviewers. For analysis of collected data, the PASW 18.0 program was used, which included descriptive analysis, t-test, ANOVA, Scheffe test, Pearson correlation coefficients, and Multiple regression. Results: Results showed a positive correlation between life satisfaction, health behaviors, and successful aging. Life satisfaction, self-perceived health status, and health behavior explained 60.8% of successful aging. Conclusion: There is a need to help improve health behavior and self-perceived health status of elders. We should also understand life satisfaction over their life span and establish a program that encourages healthy behavior in the community. Accordingly, these efforts will allow for achievement of a more successful aging process for the elderly.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.950-958
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• 2018

The physicochemical characteristics and oxidative stability of wet-aged and dry-aged pork cuts were investigated at different aging periods (1, 7, 14 and 21 d). Samples were assigned into four groups in terms of shoulder blade-wet aging (SW), shoulder blade-dry aging (SD), belly-wet aging (BW), and belly-dry aging (BD). SD showed significantly higher pH at 21 d of aging than the other samples. Wet-aged cuts had significantly higher released water (RW) %, lightness ($L^*$) and shear force compared to the dry-aged meats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed greater degradation of proteins for dry-aged cuts than the wet-aged cuts. At the end of aging, wet-aged cuts showed significantly lower thiobarbituric acid-reactive substances (TBARS) value than the dry-aged samples, indicating higher oxidative stability for wet-aged pork cuts. However, dry-aging led to higher degradation of proteins resulting in increased water-holding capacity (WHC) and decreased shear force value.

• Molecules and Cells
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• v.42 no.3
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• pp.210-217
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• 2019

The maintenance of mitochondrial function is closely linked to the control of senescence. In our previous study, we uncovered a novel mechanism in which senescence amelioration in normal aging cells is mediated by the recovered mitochondrial function upon Ataxia telangiectasia mutated (ATM) inhibition. However, it remains elusive whether this mechanism is also applicable to senescence amelioration in accelerated aging cells. In this study, we examined the role of ATM inhibition on mitochondrial function in Hutchinson-Gilford progeria syndrome (HGPS) and Werner syndrome (WS) cells. We found that ATM inhibition induced mitochondrial functional recovery accompanied by metabolic reprogramming, which has been known to be a prerequisite for senescence alleviation in normal aging cells. Indeed, the induced mitochondrial metabolic reprogramming was coupled with senescence amelioration in accelerated aging cells. Furthermore, the therapeutic effect via ATM inhibition was observed in HGPS as evidenced by reduced progerin accumulation with concomitant decrease of abnormal nuclear morphology. Taken together, our data indicate that the mitochondrial functional recovery by ATM inhibition might represent a promising strategy to ameliorate the accelerated aging phenotypes and to treat age-related disease.

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.1-10
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• 2005

This study was conducted to examine how Korean elderly perceive elements of successful aging, and to explore the meanings of a successful life in the contexts of the life experiences of the Korean elderly. From life-contextual perspectives, this study explored differences in perception on successful aging by gender and by class (economic status). Forty elderly persons aged 65 and over participated in this study. The data on the perceptions of successful aging in their own life contexts were collected through in-depth interviews. The major result of this study indicates that there are differences in the key theme of successful aging by class (economic status), because cultural and economic contexts influenced the elderly persons' perception of successful aging. This study will help researchers, educators, and practitioners to understand successful aging experience as well as establish the concept of successful aging among Koreans.

• Korean Journal of Community Nutrition
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• v.6 no.5
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• pp.773-788
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• 2001

The purpose of this study was to investigate the difference in nutrient intake according to the level of self-perception of health status, aging status and life satisfaction of the rural elderly. The factors for the study were surveyed by interview method. The subjects were 270 people(71 male, 129 female) aged over 65 years(73.5 $\pm$ 5.6ys) in the Ham-an area. The obtained results as follows : By evaluation of self-perception of health status, 57.5% of subjects answered they are in a bad health condition. The 91.5% of subjects had diseases(rheumatitis & arthritis 31.4%, cardiovascular disease 20.2%, gastric disease 10.2%). The women had more diseases than the men(p < 0.01). The subjects took medical treatment in private hospital(40.5%) and public health centers(35.0%). The men showed better level of aging status(p < 0.001) and life satisfaction index(p < 0.01) than the worsen. Living with spouse influenced the aging status(p < 0.05) and the more pocket money influenced life satisfaction(p < 0.05) and aging status(p < 0.05). The elderly who eat regularly 3 times a day(p < 0.05) and have a good appetite(p < 0.001) appeared to have positive effect on the self perception of health status and aging status. An increasing level of the self-perception of health status and regular exercise worked to improve aging status(p < 0.001). The habits of smoking and alcohol drinking, however had no effect on any index. The self-perception of health status affected the nutrient intake, but only in female elderly. The aging status and the life satisfaction index related overall positively to the intake of nutrients. In conclusion, the study shows that gender did influence nutrient intake in the elderly. The women who live alone rated lowest in social resources and health condition therefore their nutrient intake was also extremely in deficit. For successful aging, a program for rural elderly is needed, i.e. actions to provide minimum economic life, food delivery and psychological/physical health care through regional public health centers.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.379-387
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• 2019

The effects of dry-aging on changes in taste compounds and electronic taste sensing traits of pork were investigated. Ten pork belly and shoulder blade cuts were divided into wet-aging and dry-aging treatments and stored for 21 days at $2^{\circ}C$. The contents of nucleotides and free amino acids, and electronic tongue analysis were investigated at different aging periods (1, 7, 14, and 21 days). The contents of inosine and hypoxanthine of dry-aged pork cuts increased more rapidly, and they were significantly (p<0.05) higher than wet-aged pork cuts. Total free amino acids of dry-aged pork cuts were also significantly (p<0.05) higher than those of wet-aged pork cuts after 21 days of aging. Consequently, umami intensity of dry-aged pork cuts increased more rapidly and the values were significantly (p<0.05) higher than those of wet-aged pork during 21 days of aging. Results suggested that the better palatability of dry-aged pork cuts might be due to higher umami intensity in relation to higher contents of inosine, hypoxanthine, and free amino acids.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1151-1168
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• 2023

Tenderness and taste characteristics of meat are the key determinants of the meat choices of consumers. This review summarizes the contemporary research on the molecular mechanisms by which postmortem aging of meat improves the tenderness and taste characteristics. The fundamental mechanism by which postmortem aging improves the tenderness of meat involves the operation of the calpain system due to apoptosis, resulting in proteolytic enzyme-induced degradation of cytoskeletal myofibrillar proteins. The improvement of taste characteristics by postmortem aging is mainly explained by the increase in the content of taste-related peptides, free amino acids, and nucleotides produced by increased hydrolysis activity. This review improves our understanding of the published research on tenderness and taste characteristics of meat and provides insights to improve these attributes of meat through postmortem aging.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.3
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• pp.66-72
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• 2011

The annals of Joseon Dynasty is one of UNESCO's Memory of the World Register. For the safety preservation of the waxed annals of Joseon Dynasty, the acidic and alkaline aging mechanism of beeswax and beeswaxed Hanji has been investigated. The weight loss of beeswaxed Hanji by the acidic aging was higher than those of alkaline beeswax. The acid value and relative intensity of carbonyl groups in beeswax were slowly increased with aging time. The strength of dewaxed Hanji was decreased with aging time. The significant changes of crystallinity of dewaxed Hanji by acidic and alkaline aging were not observed.