• 한국표면공학회지
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• 제50권6호
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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.

• 한국간호교육학회지
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• 제11권1호
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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.

• 한국학교ㆍ지역보건교육학회지
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• 제20권3호
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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.

• 한국자동차공학회논문집
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• 제5권3호
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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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• 제5권3호
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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.

• 대한금속재료학회지
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• 제49권6호
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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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• 제12권2호
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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.

• 한국산학기술학회논문지
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• 제21권11호
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• pp.595-601
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• 2020

10년 이상 보관된 니트로셀룰로오스 (Nitrocellulose, 니트로셀룰로오스) 재질의 화약용기 안전 검사를 진행하는 과정 중 화약이 보관되어진 용기에 균열이 발생한 것을 확인하여 고장 원인 분석 시험을 실시하였다. 고장이 발생한 데에 영향을 준 요인을 선별하기 위해 먼저 고장수목분석(Fault Tree Analysis, FTA)을 통해 고장 요인 및 원인에 대해 탐구하였으며, 보관 시 발생할 수 있는 내·외부적인 요인 및 환경에 대한 영향성을 확인한 결과 열에 의해 화학 반응이 가속화되어 발생한 화약용기의 물성 변화가 고장의 원인인 것으로 추정하였다. 이를 확인하기 위해 자연 노화된 화약용기를 이용하여 열충격시험, 양립성 시험 등의 환경시험을 수행하여 고장의 원인 분석을 수행하였으며, 가속노화시험을 통해 고장 재현 시험을 실시하였다. 이를 통해 앞선 고장수목분석 결과와 같이 열과 화약에 의해 화학 반응이 가속화되는 것을 확인할 수 있었으며, 화약용기의 물성이 변화하는 것을 확인하였다. 또한, 열 노화에 의한 수명 추정을 위해 아레니우스 모델(Arrhenius Model)을 이용하여 화약용기의 사용 수명을 추정하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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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

• 한국자동차공학회논문집
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• 제12권4호
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• pp.181-190
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• 2004

The interest of the fatigue life of rubber components such as engine mounts is increasing according to the extension of warranty period of the automotive components. Automotive engine mounts get damaged due to thermal and mechanical loadings. This paper discusses a fatigue life prediction of the 3-dimensional dumbbell specimens for natural rubber compound considering the effects of maximum strain and heat aging temperature. Displacement controlled fatigue life tests were performed using specimens with different levels of maximum strain and various hardness. The basic mechanical properties test and the fatigue test of aged rubber specimen under normal and elevated temperature were executed. A procedure to predicted the fatigue life of vulcanized natural rubber material based on the maximum strain method was proposed, and then this curve was in good agreement with fatigue test data less than 200% error range.