• 제목/요약/키워드: aging characteristics

검색결과 1,794건 처리시간 0.036초

촉매의 열화에 관한 연구 I (Study I of Catalyst Aging)

  • 손건석;이지연;이귀영;최병철
    • 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.

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가속열화시험에 의한 폴리머애자의 신뢰성 평가 (Reliability Assessment of Polymer Insulators by Accelerated Aging Test)

  • 한채홍;이병성;정종욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
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    • pp.10-14
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    • 2001
  • In order to assess the long-tenn reliability of polymer insulators for distribution power systems, we have developed the accelerated aging test method which can simulate the operation conditions. In this study, 3000 hours aging test for 4 kinds of polymer insulators has been completed by the developed accelerated aging test. After 3000 hours aging test, visual inspection and electrical tests were carried for identifying a change of characteristics. Some specimens showed the surface erosion and the manufacturing defect. In the electrical tests, the wet flashover voltage was significant1y decreased by the accelerated aging test. In comparison with the field-aged polymer insulators, it can be concluded that the developed test method can evaluate the long-tenn reliability within short time and screen the manufacturing defect.

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Degradation of Epoxy Coating due to Aging Acceleration Effects

  • Nah, Hwan Seon;Lee, Chul Woo;Suh, Yong Pyo
    • 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.

중년기 성인의 노화불안, 우울 및 자아존중감에 대한 연구 (A Study on Aging Anxiety, Depression, and Self-esteem of Middle-aged People)

  • 김순이;이정인
    • 기본간호학회지
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    • 제14권1호
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    • pp.103-109
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    • 2007
  • Purpose: The purpose of this study was to investigate the relationship among aging anxiety, depression, and self-esteem of middle-aged people. Method: The study was designed as a descriptive correlation study Data were collected using a structured questionnaire which included general characteristics, and measures of aging anxiety, depression, and self-esteem. Data collection was done between March 15 and June 10. 2006 with 184 middle-aged participants. Results: The average score of the participants for aging anxiety was 48.38, for depression 16.49, and for self-esteem 29.08. There were positive correlations between aging anxiety and depression, aging anxiety and self-esteem. There was a negative correlation between depression and self-esteem. The correlations were statistically significant. Conclusion: Therefore, nursing program should be developed to improve the mental health and increase the qualitative life of middle-aged people.

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The relationship between SOC strategy, life satisfaction, and successful aging in middle-aged women

  • Gie Ok Noh
    • 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.

Meat Quality Changes in Aged Pork Loin using Jeju Volcanic Scoria Earthenware

  • DongGyun Kim;SangHoon Lee;GwangHeun Kim;KyoungBo Ko;YounChul Ryu
    • 한국축산식품학회지
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    • 제43권5호
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    • pp.901-913
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    • 2023
  • This study aimed to investigate changes in the quality of meat aged using Jeju scoria earthenware. Water-holding properties, pH, color, tenderization, fatty acid composition, and free amino acid characteristics of aged pork loin were evaluated to determine the effects of wet and dry (normal and Jeju Scoria) aging methods and aging time (0, 10, 20, 30, and 40 days) on meat quality. The aging methods altered pH and CIE L* after 10 days of aging. However, the aging method did not alter the pH and CIE L* of the aged pork loin after 10 days of aging. The shear force was significantly lower in the Scoria aging method than in the wet aging method after 10 and 20 days of aging. Both the normal and Scoria aging methods increased aging loss compared to the wet aging method, which could be attributed to longer air exposure times of the two non-packaged aging methods than in the packaged aging method. The scoria aging method had significantly higher contents and ratios of saturated (SFA) to mono-unsaturated fatty acids but lower ratios of poly-unsaturated fatty acids to SFA than the wet aging method. The content of most free amino acids significantly increased with aging time, especially those related to the sweet, and umami categories. In summary, this study suggests that the Scoria aging method provides positive aspects of eating quality, such as improvement of meat tenderness and taste, including umami, with minimum changes in the overall meat quality.

주거 특성이 지역사회 지속거주 의사에 미치는 영향 (The effect of Housing related characteristics on Aging in place among Older adults)

  • 정찬우;한창근
    • 한국노년학
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    • 제41권3호
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    • pp.373-396
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    • 2021
  • 본 연구는 우리나라 노인의 Aging in place 실현을 위해 노년기 주거 특성이 지역사회 지속거주 의사에 미치는 영향을 검증하고자 하였다. 지역사회 지속거주 의사에 있어 노인의 건강상태가 중요하기에 건강할 경우와 건강하지 않을 경우를 같이 고려하였고, 주거특성을 경제적 측면인 자가 보유 여부, 주거비 부담, 환경적 측면인 주거 편리성, 주택만족도, 주거환경만족도로 구분하여 지역사회 지속거주 의사와의 관계를 살펴보았다. 이를 확인하기 위해 2017년 노인실태조사 자료를 사용하여 노인 9,798명을 대상으로 분석을 하였다. 분석결과, 첫째, 건강할 경우와 건강하지 않을 경우를 같이 고려하였을 때 지역사회 지속거주를 선택한 노인이 6,704명(68.4%), 건강할 경우에는 지역사회 지속거주를 선택하지만, 건강상태가 악화될 경우 지역사회 지속거주를 선택하지 않는 노인이 3,094명(31.6%)으로 파악되었다. 둘째, 지역사회 지속거주 의사별 평균 주거 특성을 비교한 결과, 지역사회 지속거주를 선택한 노인집단이 그렇지 않은 노인집단보다 주거비 부담은 적었으며 주택만족도와 주거환경만족도가 통계적으로 유의미하게 높게 나타났다. 셋째, 이항 로지스틱 분석결과 주거특성 중 경제적 요인인 자가를 보유할 경우, 주거비 부담이 적을수록 지역사회 지속거주를 선택할 가능성이 높았고, 환경적 요인인 노인을 위한 설비를 갖춘 경우와 주택만족도, 주거환경만족도가 높을수록 지역사회 지속거주를 선택할 가능성이 높은 것으로 나타났다. 본 연구결과를 통해 노인의 실제 선호하는 Aging in place의 욕구를 파악하였고, 노인의 욕구를 존중하면서 진정한 Aging in place의 실현을 위해 실천적, 정책적 제안을 제시하였다. 노인의 주거에 초점을 맞추어 경제적 측면에서 주거안정성을 높여줄 노후준비와 주거비용 경감의 필요성, 주거환경의 측면에서 고령친화적인 주택환경과 지역사회 인프라 구축의 필요함을 강조하였다.

물-시멘트비와 재령이 콘크리트의 염소이온 확산특성에 미치는 영향 (Effect of Water-Cement Ratio and Aging on the Characteristics of Chloride Ions Diffusion in Concrete)

  • 배수호;정영수;김진영;하재담;심은철;임병탁
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.737-742
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    • 2002
  • The chief factors for the penetration and diffusion of chloride ions in concrete are water-cement ratio(w/c), aging, thickness of cover concrete, chloride ions concentration of given environment, wet and dry conditions and etc. In this study, effect of w/c and aging on the characteristics of chloride ions diffusion in concrete were researched when environmental factors for the penetration and diffusion of chloride ions were constant. For this purpose, the voltages passing through the diffusion cell were measured by using accelerated test method using potential difference, and then diffusion coefficients of chloride ions by using Andrade's method were estimated for 44%, 49.5% and 55% of w/c, respectively. As a result, correlation among diffusion coefficients of chloride ions, w/c and aging were concluded through multiple regression model.

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생체주입용 Ni-Ti 합금의 시효특성(I) (Characteristics of Aging of Ni-Ti Alloy Used for Implant Fabrications(I))

  • 조형준;이준희;박기룡
    • 대한의용생체공학회:의공학회지
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    • 제10권3호
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    • pp.261-268
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    • 1989
  • The characteristics of aging of near-equiatomic Ni-Ti alloy has been studied by the three point bend test and the measurement of Differential Scanning Calorimetry(DSC). The DSC is used to measure precise transformation temperatures and the amount of thermal energy required for the corresponding phase transformation. The effort of hardness on aging treatment in saline solution of $37^{\circ}C$ was higher for the annealed than solution treated specimens. As the testing temperature inc- rease from under $M_f$ to above $A_f$ temperature, the elastic stiffness increased. Almost full recovery can be achieved after bending below Belo outer fiber strain. Total bend recovery decreased gradually as aging time and bend angle is increased.

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ZPCCL계 바리스터 세라믹스의 DC 가속열화특성 (DC Accelerated Aging Characteristics of ZPCCL-Based Varistor Ceramics)

  • 김향숙;남춘우
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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    • pp.629-633
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    • 2002
  • The degradation behaviour of ZPCCL-based varistor ceramics composed of 97.5 mol%ZnO-0.5 mol% $Pr_6O_{11}-1.0$ mol% $Cr_2O_3-0.5$ mol% $La_2O_3$ was investigated under various DC accelerated aging streses. The varistor ceramics sintered for 1 h exhibited excellent nonlinearity, in which the nonlinear exponent is 81.6 and the leakage current is $0.2{\mu}A$. It was found that this varistor ceramics possess high stability, in which the variation rates of varistor voltage, nonlinear exponent, and leakage current are -1.14%, -3.7%, and 85.0%, respectively, against DC accelerated aging stress. On the contrary, the varistor ceramics sintered for 2 h also exhibited high nonlinearity and stability, but they were bad characteristics, compared with the varistor ceramics sintered for 1 h.

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