• Elastomers and Composites
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• v.41 no.1
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• pp.19-26
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• 2006

In this study, the effect of thermal aging temperature on the weight loss, glass transition temperature, and morphology of epoxy adhesives cured with amine (D-230), amide (G-5022), and anhydride (HN-2200) was investigated. As a result, the weight loss of three specimens was increased with increasing the thermal aging temperature. The result was attributed to the thermal aging which was occurred at the surface of adhesive specimens at high aging temperature, resulting in increasing the weight loss of the specimens. According to the DSC result, the glass transition temperature of DGEBA/D-230 and DGEBA/G-5022 samples war increased as the aging temperature increased, whereas the glass transition temperature of DGEBA/HN-2200 samples was constant above aging temperature of $150^{\circ}C$ and aging tine of 7 days. The SEM result indicated that the surface of DGEBA/G-5022 specimen showed more rough topography than that of DGEBA/D-230 or DGEBA/HN-2200 specimen after thermal aging. This could be correlated with the result of weight loss.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.510-519
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• 2019

The effect of combined electron-beam irradiation and aging temperature of pork on microbiological and physicochemical properties was investigated. The samples from pork shoulder were irradiated with 0 or 2 kGy, vacuum-packaged, and assigned randomly to an aging temperature ($2^{\circ}C$, $10^{\circ}C$, or $25^{\circ}C$) during 8 d. On 4 d of aging at $25^{\circ}C$, total aerobic bacteria of non-irradiated ones reached 7 Log CFU/g which is no salable levels. Shear force values of irradiated meat after aging for 2 and 4 d at $25^{\circ}C$ was lower than those aged at $2^{\circ}C$. Irradiated samples at $2^{\circ}C$ had lower cooking loss after 2 and 8 d of aging, compared with other aging temperatures. Irradiation did not accelerate 2-thiobarbituric acid reactive substance (TBARS) value when aged up to 4 d. Irradiated samples aged at $10^{\circ}C$ and $25^{\circ}C$ for 8 d scored significantly higher TBARS values. With an increased aging period, $a^*$ and $b^*$ in irradiated samples at $2^{\circ}C$ slightly increased, but irradiation caused negligible changes in meat color. The highest contents of a desirable nucleotide flavor compounds (inosine-5-phosphate) were observed in pork at $2^{\circ}C$ when aged for 4 and 8 d, while the lowest contents were observed at $25^{\circ}C$. Aging in irradiated pork for 8 d at $2^{\circ}C$ resulted in optimal condition with improved meat quality and minimal microbiologically negative defect.

• Particle and aerosol research
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• v.5 no.2
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• pp.45-52
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• 2009

Black carbon, which is a by-product of combustion of fossil fuel and biomass burning, is the component that imposes the largest uncertainty on quantifying aerosol climate effect. The direct, indirect and semi-direct climate effects of black carbon depend on its state of the mixing with other water-soluble aerosol components. The process that transforms hydrophobic externally mixed black carbon particles into hygroscopic internally mixed ones is called "aging". In most climate models, simple parameterizations for the aging time scale are used instead of solving detailed dynamics equations on the aging process due to the computation cost. In this study, a new parameterization for the black carbon aging time scale due to condensation and coagulation is presented as a function of the concentration of hygroscopic atmospheric components and the black carbon particle size. It is shown that the black carbon aging time scale due to condensation of sulfuric acid vapors varies to a large extent depending on the sulfuric acid concentration and the black carbon particle size. This result indicates that the constant aging time scale values suggested in the literature cannot be directly applied to a global scale modeling. The aging time scale due to coagulation with internally mixed aerosol particles shows an even stronger dependency on particle size, which implies that the use of a particle-size-independent aging time scale may lead to a large error when the aging is dominated by coagulation.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.668-676
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• 2019

This study aimed to investigate the effect of an electric field refrigeration (EFR) on the quality characteristics of pork loin including dry aging loss, pH, water holding capacity (WHC), cooking loss, color, shear force, thiobarbituric acid reactive substances (TBARS), and microbial growth during dry aging (0, 1, 2, 3, 4, 7, and 9 wk) in comparison with a commercial refrigerator (CR). Total plate counts (TPC) of the CR group approached 8.07 Log CFU/g at 2 wk of dry aging, thus indicating meat spoilage. Cooking loss, lightness, and shear force of EFR were significantly decreased (p<0.05) at subsequent aging weeks in both the EFR and CR. Aging loss, TPC, TBARS levels increased at subsequent aging weeks; however, pH values were not influenced by aging. At the same aging weeks (1 or 2 wk), the EFR group displayed significantly lower values (p<0.05) of aging loss, pH, TPC, and TBARS levels than the CR group. No significant differences in WHC, cooking loss, and shear force was observed until 2 wk of aging between the EFR and CR groups. The present results show that application of the EFR system improves the tenderness, color, and lipid oxidation stability of pork loin and extends its shelf life in comparison with a commercial refrigeration.

• Industry Promotion Research
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• v.8 no.3
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• pp.69-78
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• 2023

Based on the perception that integrated retirement preparation in various areas is needed in preparation for increased old age, this study aims to identify the status and characteristics of retirement preparation of middle-aged people and reveal the relationship with successful aging. In addition, it aims to find out the mediating effect of social support in the relationship between retirement preparation and successful aging for the middle-aged. To confirm this, 1,037 men and women aged 50 to 64 who responded to the third, fourth, and fifth additional surveys of the Korean Retirement & Income Study (KReIS) conducted by the National Pension Research Institute were analyzed. When the preparation of middle-aged people for retirement affects successful aging, bootstrapping with IBM SPSS 26 Process Macro Model 4 was conducted to verify the mediating effect of social support. As a result of verifying the significance of independent variables on the parameters, preparation for retirement was positively (+) significant. In other words, it was verified that the higher the preparation for retirement, the higher the social support. Furthermore, it was discovered that social support, an independent variable, had a significant impact on successful aging, and social support, an independent variable, had a significant impact on successful aging. The results of this study suggest the need for social support for successful aging through the preparation of middle-aged people for retirement. It is intended to derive policy implications for preparing for retirement and provide them as basic data to increase the level of successful aging.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.593-600
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• 2019

The aim of this study is to enhance the level of life satisfaction of the elderly as the aging population grows in readiness for increased old age, beginning with interest in improving the quality of life of the elderly. For this purpose, the subtype of preparation for aging was set as multi-independent variables by organizing it into physical preparation for aging, economic preparation for aging, and emotional & social preparation for aging. Structural relationships between variables was identified by social support a parameter variable and life satisfaction a dependent variable. It was also verified that the social support between subtypes of preparation for aging and life satisfaction had a mediating effect. The subjects of this study are 4,058 elderly people who are over the age of 65. They were originally extracted from the 3rd and 5th additional survey of Korean Retirement and Income Study. For data analysis purposes, SPSS 25.0 and SPSS PROCESS macro v2.16 were used. The results of this study are as followed. The emotional & social preparation for aging not only had a significant direct effect on successful aging, but also resulted in indirect effect on successful aging through life satisfaction. On the basis of the results, this study provided the social welfare policy and practical suggestions to enhance the preparation for aging and social support, which are the key to improving life satisfaction of the elderly.

• Journal of the Korean Geotechnical Society
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• v.20 no.6
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• pp.109-118
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• 2004

The consolidation of clay occurs with time lag, and this kind of lag can be separated into plastic lag and hydraulic lag. In this study, CRS tests were performed to research the effect of original secondary consolidation of the clay with respect to the characteristics of consolidation. Test results showed that plastic time lag was one of the key factors to get the preconsolidation pressure, and suggested the formula of the Quasi-preconsolidation pressure obtained from the relationship between consolidation time lag and consolidation pressures. In addition though the characteristics of coefficient of consolidation show a wide range of values, after passing the double preconsolidation point, it showed the tendency to converge into the constant value. The coefficient of permeability in normally consolidated state is related to its void ratio, and the permeability variables, n and $C_1$ were determined by the test results using the equation suggested by Samarasinghe. et. al. And then the equation was compared with the Kozeny-Carman's equation. Because of delayed compression caused by consolidation time lag, aging effect could be also found in the relationship between coefficient of permeability and void ratio.

• 한국노년학
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• v.29 no.4
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• pp.1413-1425
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• 2009

The objective of the work is to analyze the factors affecting on changes in filial piety responsibility expectation. For the analysis, this study focuses on the two factors-aging effect and cohort effect. This work analyzes the 4 wave Hallym Aging Panel Data with random intercept model. In the study cohort is divided by the criteria of birth year 1940. and the former cohort is called colony-war cohort and the latter cohort is called industrialization-democratization cohort. The results are in following. First, older cohort shows higher filial piety responsibility expectation score than younger cohort. Second, age shows no relationship with filial responsibility expectation score. Third, male and resident in rural area shows higher score. Forth income, year of schooling, and subjective health show negative relationship with responsibility score.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.117-131
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• 2018

The purpose of this study is to examine the effect of economic stress on aging anxiety focusing on the moderating effect of motivations for participation in volunteering, and age. In order to accomplish these purposes, a total of 182 elderly who have been volunteering were used for final analysis. The results from the multiple regression showed that economic stress increases aging anxiety among elderly and motivations for participation in volunteering are likely to mitigate aging anxiety. Also, aging anxiety is expected to be lower as people are older and have higher self-oriented motivation for volunteering. Based on the result, political and practical implications are discussed.

• 한국노년학
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• v.36 no.4
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• pp.1075-1088
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• 2016

This study aimed to identify the effect of the active aging on life satisfaction and present an improvement strategies to increase life satisfaction in elderly people. Active aging is divide into three aspects; health, participation and security. The subjects were people older than 55 years who were enrolled in Korean Retirement and Income Study. The influencing effect was analyzed by a hierarchial regression. Key factors associated with active aging influencing life satisfaction were subjective health, mental health, participation in the labor market, income, and housing while subjective health was a determinant factor that best describes the effect of the active aging on life satisfaction. On the basis of above result, this study suggests that there needs to be an effort in improvement of physical and mental health, participation in the labor market, and housing at national and regional levels.