• Journal of the Korean institute of surface engineering
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• v.13 no.4
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• pp.211-220
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• 1980

Internal stress of electrodeposited metals affect physical and mechanical characteristics of deposits. Internal stress of nickel deposits was reviewed intensively. Important outcomes are as follows. Substrate have an important effect on internal stress of electrodeposit. Origin of its internal stress could be explained mismatch of crystal lattice and coalescence of crystallites. When surface cleaning is not satisfying, instantaneous stress is low but the electrodeposited layer being thickened increasingly stress become to high and peeling phenomenon occurs. Effect of current density and temperature on internal stress is variable. Internal stress increases rapidly at pH 5 and above because of codepositing colloidal materials caused hydrolysis. Concentrations of nickel ion and $H_3BO_3$ ion affect little on internal stress and solution which contains impurities tend to increase stress. Especially impurities of $H_2O_2$ and iron ion have a great effect on internal stress. Additives are divided in two kind. One is increasing tensile stress another is increasing compressive stress. Concentrations of additives have a great effect on internal stress.

• Korean Journal of Human Ecology
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• v.24 no.2
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• pp.219-236
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• 2015

The purpose of this study is to examine the effect of the elderly's stress on depression, and also to verify the mediating effect of the elderly's resilience and the moderating effect of their social activity between stress and depression. To achieve the purpose of this study, questionnaire survey was conducted. Research subjects of this study were 487 elderly people who were 60 years old and over in Gimhae area. Both the elderly participating in senior welfare center or community center and home care elderly people were included in survey. The study results are as follows: First, there were significant influence of the elderly's stress on depression. Second, the mediating effect of the elderly's resilience between stress and depression was verified. Both the direct effect of stress on depression and indirect effect of stress through resilience on depression were verified. Third, the moderating effect of the elderly's social activity between stress and depression was verified. It was found that the harmful effect of the elderly's stress on depression could be alleviated by participation in social activity. Through the study result, the elderly's resilience which is internal resource, is needed to be strengthened to alleviate depression derived from stress. Also, the elderly's active participation in social activity is needed to be encouraged to prevent the harmful effect of the elderly's stress on depression. Therefore, it is recommended that programs enhancing resilience of the elderly should be developed and the elderly should be supported to participate in social activity more actively.

• Korean Journal of Child Studies
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• v.35 no.3
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• pp.1-14
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• 2014

This study examined the moderated mediating effect of stress by self-concept on the influence of ego-resiliency on school adjustment in children. The participants consisted of 278 4th-graders, who completed self-report questionnaires designed to assess ego-resiliency, school adjustment, self-concept, and stress. The results indicated the following: First, stress mediated the effect of ego-resiliency on school adjustment. Second, self-concept moderated the effect of stress on school adjustment. Third, the mediating effect of stress on the influence of ego-resiliency on school adjustment was moderated by self-concept. The mediating effect of stress was statistically significant when self-concept was positive, but was not statistically significant when self-concept was negative. Methods to improve children's school adjustment are also included, based on the results of this research.

• Geomechanics and Engineering
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• v.14 no.2
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• pp.203-209
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• 2018

Reliable estimation of compressive as well as tensile in-situ stresses is critical in the design and analysis of underground structures and openings in rocks. Kaiser effect technique, which uses acoustic emission from rock specimens under cyclic load, is well established for the estimation of in-situ compressive stresses. This paper investigates the Kaiser effect on marble specimens under cyclic uniaxial compressive as well as cyclic uniaxial tensile conditions. The tensile behavior was studied by means of Brazilian tests. Each specimen was tested by applying the load in four loading cycles having magnitudes of 40%, 60%, 80% and 100% of the peak stress. The experimental results confirm the presence of Kaiser effect in marble specimens under both compressive and tensile loading conditions. Kaiser effect was found to be more dominant in the first two loading cycles and started disappearing as the applied stress approached the peak stress, where felicity effect became dominant instead. This behavior was observed to be consistent under both compressive and tensile loading conditions and can be applied for the estimation of in-situ rock stresses as a function of peak rock stress. At a micromechanical level, Kaiser effect is evident when the pre-existing stress is smaller than the crack damage stress and ambiguous when pre-existing stress exceeds the crack damage stress. Upon reaching the crack damage stress, the cracks begin to propagate and coalesce in an unstable manner. Hence acoustic emission observations through Kaiser effect analysis can help to estimate the crack damage stresses reliably thereby improving the efficiency of design parameters.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.162-166
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• 1996

This study was done to investigate whether cholic acid derivatives have anti-stress activity and what is a cause of this anti-stress effect. Seven cholic acid derivatives (cholic acid, taurocholic acid, ursodeoxycholic acid, tauroursodeoxychoic acid, chenodeoxy cholic acid, dehydrocholic acid, hyodeoxycholic acid) were used, silymarin and valproic acid were used as positive controls. Stress was induced by restraint immobilization technique plus water immersion (24hrs) and adrenal weight, spleen weight, adrenal ascorbic acid, serum cholesterol, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), adrenal cholesterol, glucose and corticosterone levels were measured as stress indicators. Most cholic acid derivatives markedly decreased the adrenal weight, and TUDCA and DHCA increased the spleen weight. The restraint stress induced increments in serum LDH, ALP and cholesterol were attenuated by most cholic acid derivatives. Cholic acid, taurocholic acid and tauroursodeoxycholic acid only increased the content of adrenal ascorbate. While valproic acid showed an inhibitory effect against stress, silymarin did not. Our findings suggest that most cholic acid derivatives have anti-stress effect and that their anti-stress effect is, in part, related to choleretic activity.

• Journal of Korean Society of Rural Planning
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• v.28 no.2
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• pp.1-9
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• 2022

This study analyzed the effect of young farmers' stress on farming satisfaction and Intention to Leave the Farming. The analysis targets young people living in rural areas and engaged in agriculture among 4H members nationwide. As a result of the analysis, there were significant differences in stress of young farmers according to the characteristics of the investigator, and there were differences according to family composition and community activities. In addition, family stress and social stress showed significant results according to the type of young farmers, community activities, and economic stress according to the type and family composition of young farmers. And the stress of young farmers had a positive (+) effect on Intention to Leave the Farming, and family and social stress also had a positive (+) effect on Intention to Leave the Farming. In addition, the stress of young farmers affected farming satisfaction, and family stress and social stress also had a negative (-) effect on farming satisfaction. Therefore, efforts will be needed to improve farming satisfaction and reduce Intention to Leave the Farming by reducing stress among young farmers.

• Korean Journal of Human Ecology
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• v.8 no.2
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• pp.227-243
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• 1999

The purpose of this study was to analyze a causal relations of children's learned helplessness, stress, perception of self-competence and mother's childrearing attitudes. The subjects were 370 of 4th and 6th grade in elementary school and the second grade in junior high school in Busan and their's mothers. The instruments used for this study were learned helplessness scale, stress scale, self-perception profile for children, and childrearing attitude scale. The data was analyzed with pearson's correlation, multiple regression and path analysis. The major findings of this study were as follows : 1. Children's global self-worth, social self, age and mother's controlling childrearing attitudes predicted children's stress. 21% of the variance of children's stress was explained by these variables. 2. Children's stress, global self-worth, academic and social self predicted children's learned helplessness. 54% of the variance of children's learned helplessness was explained by these variables. 3. 1) Global self-worth was the first contribution and had a indirect effect through stress as well as a direct effect on children's learned helplessness. 2) Children's stress and academic self had direct effect on children's learned helplessness. 3) Children's social self had a indirect effect through stress as well as a direct effect on children's learned helplessness. 4) Mother's affectionate childrearing attitudes had indirect effect through academic, and social self and global self-worth on children's learned helplessness. Mother's controlling childrearing attitudes had indirect effect through stress on children's learned helplessness. Children's age had a indirect effect through global self-worth and stress and children's sex had a indirect effect through social self on children's learned helplessness.

• Culinary science and hospitality research
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• v.14 no.2
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• pp.1-17
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• 2008

This study analyzed the factors related to the stress which the top-rated chefs in Jeju suffer and conducted the multiple regression analysis to look into the effect of job-related stress on the stress reaction and the satisfaction with job, in order to examine the effect of job-related stress faced by hotel kitchen employees in performing duties and determine the effect of job-related stress on the reaction of individuals in the peculiar environment of a kitchen in a hotel. Job-related stresses were classified into five factors which were physical, individual, vocational, organizational, and social. The result of regression analysis, which was performed to figure out the effect of job-related stress on the stress reaction and the satisfaction with the job, indicated that the physical factor of job-related stress had the greatest effect on the physiological reaction, followed by the organizational factor, individual factor, and social factor, while the organizational factor of job-related stress had the greatest effect on the psychological reaction, followed by the individual factor, social factor, vocational factor, and physical factor. Meanwhile, the vocational factor of job-related stress had the greatest effect on behavioral re-action, followed by organizational factor and individual factor. The vocational factor of job-related stress had the greatest effect on the satisfaction with the job, followed by individual factor, organizational factor, social factor, and physical factor.

• Journal of Korean Society of Steel Construction
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• v.8 no.3 s.28
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• pp.3-11
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• 1996

To investigate the effect of fatigue crack growth due to the surface residual stress, it is measured the residual stress distribution by x-ray diffraction at the crack tip each constant crack growth in the notch specimens, and quantitively assessed the effect of crack closure caused to the distribution of compressive stress at the crack tip from evaluating crack openning stress using the finite element analysis. It is concluded that the degree of the residual stress distribution at the crack tip is decreased with increasing the crack length. From the fact that it is similar to the crack openning stress ratio, it is found that the compressive residual stress distribution and size is related to the crack closure effect and surface residual stress field with propagating crack in the notch specimens depends on the stress intensity factor range at the crack tip.

• Journal of Power System Engineering
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• v.14 no.1
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• pp.47-52
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• 2010

In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.