• Journal of Advanced Marine Engineering and Technology
• /
• v.27 no.3
• /
• pp.453-459
• /
• 2003

In this study, the effect of heat treatment to the electrochemical polarization resistance for the Ti-6Al-4V alloy was measured. The solution heat treatments were carried out at $1066^{circ}E, 966^{\circ}$E$, followed by aging heat treated $550^{circ}E, 600^{circ}E, and 650^{circ}E$. The electrochemical polarization resistance behavior was measured by potentio-dynamic polarization in the 1N $HNO_3$ + 15ppm HF solution. The obtained results were as follows. 1. As solution heat temperature increased. the corrosion potential was increased, whereas passive current density and critical current density were decreased. 2. As aging heat temperature increased, the corrosion potential was almost constant, but passive current density was decreased 3. The results of composition test measured by EDS at grain boundary and near $\gamma'$ precipitates indicated that S, Cl. and Si which originated from base metal were segregated at the grain boundaries Al and Ti which were the main alloying element in $\gamma'$ were depleted at the $\gamma'$ precipitated. The depletion of Al and Ti in $\gamma'$ was caused to early breakdown of passive film.

• The Korean Journal of Health Service Management
• /
• v.10 no.4
• /
• pp.123-140
• /
• 2016

Objectives : This study aimed to evaluate the factors influencing health promotion behaviors in elderly men. Methods : We used data from the 6th Korea National Health and Nutrition Examination Survey. We analyzed difference between sociodemographic characters, health statuses, and health promotion behaviors by age. Logistic regression analysis was used to investigate the relation between health promotion behaviors and sociodemographic factors by age. Results : Health promotion behaviors related to aging were weight control effort, health screen examination, smoking cessation, and influenza vaccination. Socioeconomic statuses of elderly men declined from the preliminary age, and health status was influenced by the reduction of social role. Health promotion behaviors such as weight control, health screen examination, and performance of aerobic activities were decreased in men of advanced aged. Conclusions : The health promotion behaviors of elderly men differed significantly with age.

• Elastomers and Composites
• /
• v.47 no.3
• /
• pp.201-209
• /
• 2012

Grommet is one of the Automotive rubber components and is made from EPDM(Ethylene Propylene Diene monomer M-class) rubber and the nonlinear hyperelastic material properties of rubber are important to predict the behavior of rubber product. In this study, the stable stress-strain relations were obtained from the uni-axial tension test and the equi-biaxial tension test. Finite element analysis for grommet was carried out and heat aging test for the lifetime prediction of grommet was introduced.

• Journal of the Korean Society for Heat Treatment
• /
• v.34 no.5
• /
• pp.226-232
• /
• 2021

The relationship between precipitation and coefficient of thermal expansion of Al-6%Si-0.4%Mg-0.9%Cu-(Ti) alloy (in wt.%) after various heat treatments were studied by the thermodynamic analyzer (TMA) and differential scanning calorimetry (DSC). Solution heat treatment of the alloy was carried out at 535℃ for 6 h followed by water quenching, and the samples were artificially aged in the air at 180℃ and 220℃ for 5 h. The coefficient of thermal expansion (CTE) curve showed some residual strain and decreased with increasing aging temperature. The CTE curves changed sharply in the temperature range of 200℃ to 400℃, and the corresponding peak shifted for the aged samples due to the change in the precipitation behavior of the secondary phase. These transformation peaks in the aged sample are related to the volume of the precipitation of the Si phase as determined by DSC analysis. The change in CTE is mainly caused by the precipitation of the Si phase in the Al-Si alloy, and the size of the change occurs simultaneously with the size of the precipitate.

• Fashion & Textile Research Journal
• /
• v.11 no.2
• /
• pp.271-277
• /
• 2009

The purpose of this study was to examine the relationships among influence of Social Self-Efficacy, Appearance Concern, Body Cathexis, Appearance Management Behavior. The subjects of this study were 709 women aged for 20 to 50 living in Daegu. The questionnaires were conveniently sampled from December 20 to 31, 2007. The SPSS 14.0 package was use for data analysis which included Frequency analysis, Factor analysis, Cronbach's a and Analysis Structural Equation Modeling by utilizing of Amos 5.0. The results of this study were as follows; First, the social self-efficacy showed a positive influence on both appearance concern and the body cathexis. And the social self-efficacy had a negative influence on appearance management behavior. Second, appearance concern showed a positive influence on appearance management behavior, but there was not a significant relationship between appearance concern and body cathexis. Third body cathexis showed a positive influence on appearance management behavior.

• Journal of Fashion Business
• /
• v.26 no.5
• /
• pp.22-35
• /
• 2022

This study examines the image pursuit behavior according to body surveillance, body shame of image-based SNS-used women. Questionnaires were administered to 215 SNS-used women aging between 20 to 30 years old. The SPSS 25.0 package was utilized for data analysis, which included frequency analysis, factor analysis, Cronbach's α, correlation analysis and regression analysis. The study analyzed the relationship between body surveillance, body shame single factor, and subfactors of image pursuit behavior(conformity, instrumentality, fashion pursuit, attractiveness pursuit, ostentation pursuit, interpersonal). It was observed that body surveillance and body shame had a positive influence on all the factors of image pursuit behavior. Body surveillance demonstrated a high influence on attractiveness pursuit while body shame demonstrated a high influence on ostentation pursuit. Body surveillance had a positive influence on body shame. These results provide useful information for understanding the influence of social media on the psychological attitude and consciousness of women with regard to their body and image pursuit behavior. In addition, results from this study will help to systematize women's theoretical physical consciousness, establish product strategies for physical appearance-related industries, and set marketing directions.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.2061_2062
• /
• 2009

Within serviced period of time in transformer, thermal stress is the most influential parameter affecting the aging behavior of an insulation system. The thermal stress on the insulation system may occur from operation in a high temperature environment due to Joule's heat at winding coils. This paper describes a development of capacitive sensor and preventive diagnosis techniques for electrical insulating oil, widely used for power and distribution transformer. To survey the dielectric properties of the virgin and used mineral insulating oil, we utilized the highly precise measuring system of KRISS. And the results were used to determine the design factors of the sensor. To evaluate diagnosis by the sensor, we performed accelerated aging test about insulating oils. The condition of aged specimens were investigated by measurements of relative permittivity i.e. capacitance change by capacitive sensor.

• Journal of the Korean Society for Heat Treatment
• /
• v.4 no.4
• /
• pp.24-33
• /
• 1991

The effects of thermomechanical treatments on microstructure and fatigue properties of 7050 Al alloy were investigated. The precipitation kinetics changed to a faster rate due to cold deformation employed in this special TAHA thermomechanical treatments including pre-aging, plastic deformation and two step final-aging. The G.P. zones in the under-aged condition were cut by dislocations and dissolved during the plastic deformation. During the low cycle fatigue, the T6' condition showed cyclic hardening behavior whereas the TMT5, TMT27 and T76 conditions showed cyclic softening at above 0.7% total strain amplitudes. The ${\Delta}K_{th}$ value of TMT27 was improved more than two times, compared with that of T76 condition. The T6' with small shearable precipitates resulted in the markedly high ${\Delta}K_{th}$ value. This is thought to be resulted from dislocation reversibility and roughness-induced crack closure due to planarity of slip.

• Journal of the Korean Ceramic Society
• /
• v.52 no.1
• /
• pp.56-60
• /
• 2015

Discontinuous, polycrystalline $Al_2O_3$-dispersed TZP fibers were prepared by the centrifugal spinning of a colloidal $ZrO_2$ sol containing Y and Al nitrates and poly(vinyl alcohol). Factors affecting the rheological properties of the sols, such as sol concentrations, aging, and the amounts and types of additives, were investigated by measuring the shear viscosities. The flow characteristics of the sols were studied in relation to the spinnability by measuring the viscosity with respect to the shear rate. The spinnability was obtained through the addition of a polymer which increases the viscosity to a range of optimum viscosity values for spinning. Aging the sols containing the additives did not noticeably change the sol viscosities at room temperature up to 30 days. The flow behavior of the spinnable sols progressively changed from nearly Newtonian to pseudoplastic with an increase in the sol concentration.

• Journal of the Korean Society for Heat Treatment
• /
• v.9 no.2
• /
• pp.91-102
• /
• 1996

Microstructural control to produce multiphase structure has received much attention to improve the high temperature strength as well as low temperature ductility of intermetallics. Transmission electron microscopic investigation has been carried out concerning the effect of Cr-precipitation on the mechanical properties of B2-ordered NiAl containing 4 to 8 mol% of Cr. By aging at temperatures around 973 K after solution annealing, fine spherical precipitates took place homogeneously in the NiAl matrix and the alloys hardened appreciably. Selected area electron diffraction (SAED) patterns have not revealed any additional extra-spots during aging, because the Cr-particles show cube-cube orientation relationship and keep a perfect coherency with the ordered matrix lattice. Dislocations were confirmed to bypass the particles during deformation. Although the dispersion of Cr-particles increased the yield strength of NiAl at intermediate temperature, the strength decreased appreciably at higher temperatures.