• Journal of Ocean Engineering and Technology
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• v.8 no.2
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• pp.157-165
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• 1994

Effect of an accelerated iso-thermal aging (375 degree C x 66days, 375 degree C x 200days) on elastic-plastic fracture resistance curve were examined in SA533B low alloy steel. Fracture toughness test are conducted by unloading compliance method at room temperature. But the apparent negative crack growth phenomenon, usually arise in partial unloading compliance test. The phenomenon of negative crack growth may be eliminated by the offset technique. There is no effect of aging on J sub(IC) and dJ/da in iso-thermal aged (375 degree C x 66 days) specimen, but there is very little effect in iso-thermal aged (375 degree C x 200 days) specimen.

• Journal of Surface Science and Engineering
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• v.50 no.6
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• pp.492-497
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• 2017

In this study, we investigated the effect of thermal aging on mechanical characteristics of Inconel 600 nickel-based alloy. The thermal aging was conducted up to 1000 hours at an atmosphere of $650^{\circ}C$. The microstructure of thermally aged specimens was investigated by an optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). In addition, tensile test (strain rate: 2 mm/min) and micro Vickers hardness test were conducted to evaluate mechanical properties with time. As a result of the experiment, Cr-rich carbide continuously precipitated during thermal aging, leading to the change of the mechanical characteristics and fracture mode. With the increase of aging time, tensile strength, yield strength, and hardness gradually decreased. The fracture mode changed from ductile to brittle with the increase of grain boundary carbide.

• The Journal of Korean Academic Society of Nursing Education
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• v.11 no.1
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• pp.7-15
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• 2005

Purpose: The purpose of this study were to 1) degree of the aging anxiety 2) to identify predictors influencing aging anxiety of the elderly. Method: Data were collected from 179 elders & utilizing questionnaires developed by Watkins, Coates, and Ferroni(1998). Data were analyzed using SPSS/Win 10.0 program and descriptive statistics t-test ANOVA were adopted as necessary. Result: Degree of the aging anxiety were 33-60scores, mean 49.96 scores. There were significant differeence in aging anxiety scores according to relegion, and disease. conclusion : The result of this study show the aging anxiety in a improtant factor in explaining psychological health, and development of adequate intervention for the elderly population to decrease the aging anxiety.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.3
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• pp.29-42
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• 2019

Objectives: This study aimed to examine the effect of successful aging on depression and social capital(trust, norm, participation, network) of the elderly. Methods: Samples were obtained from 184 people aged over 65 years old in one county of Kyungsangbukdo. Data were analyzed with t-test, ANOVA and regression analysis. Results: First, depression, social capital and successful aging were significantly different by age, economic status and religion. Secondly, regression analysis showed that depression affected a negative influence on successful aging in Model 1, which analyzed only depression. However, Model 2, which analyzed depression and social capital at the same time, showed that only social capital affected successful aging. Conclusions: It was suggested to develop health promotion and social participation program are required for successful aging of the elderly.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.86-94
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• 1997

Quick aging of catalysts has done with IAE(Institute for advanced engineering) AGING MODE suggested by IAE. To estimate the effects of number of aging cycle, temperature and $H_2O$, characteristics of surfaces, mechanical properties and weibull modulus were estimated. Also, the conversion efficiency of aged catalysts was evaluated with model gas bench test. The area of surface and pore volume were decreased according to the number of aging cycle. The precious metal which is well dispersed in fresh state was sintered and agglomerated with aging. The mechanical of deactivation and sintering of catalysts are discussed on the basis of mechanical tests. The conversion efficiency was decreased with the repeats of aging. Especially, the existence of $H_2O$ in supply gas had a main role in catalyst deactivation withy high temperature.

• Corrosion Science and Technology
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• v.5 no.3
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• pp.99-105
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• 2006

This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

• Korean Journal of Metals and Materials
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• v.49 no.6
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• pp.448-453
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• 2011

Pre-aging heat treatment after solution heat treatment (SHT) of Al-0.4 wt%Mg-1.2 wt%Si-0.1 wt%Mn alloy sheets for auto-bodies was carried out to investigate the effect of pre-aging and its conditions on the bake-hardening response. Mechanical properties were evaluated by a tensile and Vickers hardness test. Microstructural observation was also performed using a transmission electron microscope (TEM). It was revealed that pre-aging treatments play a great role in the bake-hardening response. In addition, it was found that the sphere-shaped nanosized clusters that can directly transit to the needle-shaped ${\beta}$" phase during the paint-bake process, not being dissolved into the matrix, are formed at 343 K. The result, reveals that the dominant factor of the bake-hardening response is the pre-aging temperature rather than the pre-aging time.

• International Journal of Advanced Culture Technology
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• v.12 no.2
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• pp.326-333
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• 2024

This is a descriptive correlational study aimed at determining the relationship between SOC strategy, life satisfaction, and successful aging in middle-aged women. The study population was middle-aged women aged 40-65 years living in one metropolitan city, and 295 data collected using a structured questionnaire were used to analyze the results. The collected data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, and Pearson's correlation using SPSS WIN/PC 24.0 statistical program. In the results of this study, the general characteristics related to successful aging in middle-aged women were identified as age, occupation, religion, economic status, presence of chronic diseases, and health status perception, menopause as significant influencing variables. In addition, successful aging was positively related to SOC strategy and life satisfaction among the middle-aged women in this study (p<.05). In particular, life satisfaction was highly correlated with successful aging in this study, and in this regard, efforts should be made to develop various programs to help middle-aged women feel satisfied with their lives so that they can transition to successful aging.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.595-601
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• 2020

During the safety inspection of nitrocellulose-made explosive containers stored for more than 10 years, cracks were found in the containers. Therefore, a failure cause analysis test was performed. First, the cause of failure through the failure tree analysis was conducted to select the factors that influenced failure. The changes in the properties of the container caused by the acceleration of the reaction were found to be the cause of the failure by confirming the influence on the environment and internal/external factors that may occur during storage. To confirm this, environmental tests, such as thermal shock test and vacuum thermal stability test, were performed using a naturally aged container to analyze the cause of failure, and an accelerated aging test was performed to reproduce the failure. Through this, the chemical reaction was accelerated by heat and charge, as in the result of the fault tree analysis, and it was confirmed that the physical properties of the container were changed. In addition, the service life of the container was estimated using the Arrhenius model for the storage life due to thermal aging.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1791-1793
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• 1996

This paper describes Thermal-Mechanical performance and Ultimate Mechanical-Strength test for the purpose of aging analysis of suspension insulator. The temperature difference of insulator surface according to the aging of suspension insulator brought out about $2^{\circ}C$ to $7-8^{\circ}C$ difference comparing with the atmospheric temperature. Quality standard and Mechanical-Strength of used suspension insulator deteriorate more remarkably than that of new suspension insulator. It is required that Thermal-Mechanical performance test standard be revised in the future. And it is described about the development prospect of polymer insulators