• Journal of Ocean Engineering and Technology
• /
• v.26 no.2
• /
• pp.26-32
• /
• 2012

In this paper, the effects of irregular bead shapes on fatigue life were investigated. A modified S-N curve method was used to estimate the fatigue life, which considered the inherent multiaxiality caused by the geometrical feature produced by the welding process. The point method of the critical distance method was used to determine the fatigue effective stress. Three types of fillet joint models were tested in the fatigue experiments. For each model, real bead shapes were collected using a 3D laser scanner, and finite element analyses were performed. The results of the analyses with actual bead shapes were compared with those using an idealized bead shape model. The results of the present analytical methods showed good agreement with the experimental results.

• Tribology and Lubricants
• /
• v.13 no.3
• /
• pp.28-32
• /
• 1997

Indentation, scratch and sliding tests were carried out in this paper to predict the critical loads and the failure modes of TiN-coated specimen. The test specimens were S20C steels with three different substrate hardness, roughness and coating thickness. The scratch test shows that the coating thickness has more dominant effect on the critical load of coated disk than the hardness and the roughness. Using the percent contact load, the ratio of sliding load to the critical scratch load, the cycles to failure are measured to predict the wear-life of TiN film. On the wear-life diagram the percent loads and the cycle to failure show the good linear relation on semi-log coordinate. With decreasing loads, the diagram shows the wear-limit at which the coated disk survives more than 4000 cycles.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2000.11a
• /
• pp.378-384
• /
• 2000

This paper presents the results of the repeated sliding tests to determine the wear-life of TiN coated AISI 52100 bearing balls deposited by PVD method and to show the wear mechanisms of those. The sliding tests were carried out using a ball-on-disk tribometer under ambient conditions. The coefficient of friction, wear volume and the cycles to failures of TiN coated bearing balls were measured with different normal loads and roughness of lower specimens. On the wear-life diagram, the normal loads and the cycles to failure showed the good linear relation on log-log coordinate. With a decreasing normal load, the diagram showed that the wear-limits, at which the coated bearing balls survived more than 4000cycles were under 0.1N of the normal load.

• International Journal of Internet, Broadcasting and Communication
• /
• v.15 no.3
• /
• pp.160-165
• /
• 2023

Physical education bodybuilders compete by means of external appearance, and more and more people are starting bodybuilding with an interest in improving their individual constitution and diet. However, some of the bodybuilders in sports for life started using banned substances to show off their appearance or to expect good results in bodybuilding competitions. Prohibited drugs only have a short-term positive effect on the subject, and the seriousness of side effects was greater when taking the drug for a long time. An education program that can provide professional education and information on drugs to bodybuilding athletes for life sports should be preceded, and a system that can check regular health should be introduced if necessary. A periodic doping education program for bodybuilders for sport for life is needed to focus on the positive changes in bodybuilding through banned substances and to educate and understand the side effects and damage to life that occur later. Therefore, in order to prevent doping, it is essential to educate various aspects of doping, and it is required to expand the scope not only to elite athletes but also to participants as sports for all

• Korean Journal of Occupational Health Nursing
• /
• v.20 no.1
• /
• pp.35-45
• /
• 2011

Purpose: The purpose of this study was to propose and to test a predictive model that could explain the workers' quality of life. Methods: Data were collected using self-report questionnaires from 901 workers in Daejeon, Korea. The questionnaires included nine measured variables (safety culture, self-efficacy, activity of occupational health provider, knowledge in occupational health, age, health promotion behavior, workplace environment, health level, and quality of life), as revised PRECEDE model has suggested. The collected data were analyzed using SPSS/WIN 15 and AMOS 6.01 version. Results: Based on the constructed model, behavior, environment, and health were found to have significant direct effect on quality of life. Indirect factors were perceived biological, predisposing, reinforcing, and enabling. The proposed model was concise and extensive in predicting quality of life of the participants. The final modified model yielded GFI=.85, AGFI=.89, NFI=.79, and RMSEA=.11 and exhibited good fit indices. Conclusion: Findings of this study may contribute to development of effective nursing interventions for promoting quality of life in workers.

• Journal of East-West Nursing Research
• /
• v.13 no.2
• /
• pp.187-196
• /
• 2007

Purpose: This is a descriptive research to examine the level of health status, depression, and quality of life in the elderly, the relations among the factors. Methods: Subjects were 441 elders in Seoul and Gyung-gi province. Data were collected from July 10, 2006 to October 30, 2006. Measures were CMI, GDS, and SF-36. Data were analyzed by descriptive statistics, Pearson correlation coefficient, T-test, and ANOVA. Results: (1) The health status was the average of 1.75, which indicates being good. Depression was the average of 2.85, which indicate being high, and the quality of life was the average of 2.72, which indicate being moderately. (2) The relations indicate that the better status of health is related with the lower depression, and the better status of health is related with the higher quality of life, and the higher depression is related with the lower quality of life. (3) The health status, depression, and quality of life all showed significant differences according to age, education, past occupation, current occupation, dwelling pattern, monthly pocket money, living expense. Conclusion: for nursing intervention strategies, it are requested the special attention of the current occupation level and interpersonal relation ship in older people.

• Journal of Microbiology and Biotechnology
• /
• v.25 no.10
• /
• pp.1660-1669
• /
• 2015

The present study describes the gene cloning, overexpression and characterization of a novel nitrilase from hyperthermophilic bacterium Thermotoga maritima MSB8. The nitrilase gene consisted of 804 base pairs, encoding a protein of 268 amino acid residues with a molecular mass of 30.07 kDa after SDS-PAGE analysis. The optimal temperature and pH of the purified enzyme were 45℃ and 7.5, respectively. The enzyme demonstrated good temperature tolerance, with 40% residual activity after 60 min of heat treatment at 75℃. The kinetic constants V_max and K_m of this nitrilase toward 3-cyanopyridine were 3.12 μmol/min/mg and 7.63 mM, respectively. Furthermore, this novel nitrilase exhibited a broad spectrum toward the hydrolysis of the aliphatic nitriles among the tested substrates, and particularly was specific to aliphatic dinitriles like succinonitrile, which was distinguished from most nitrilases ever reported. The catalytic efficiency k_cat/K_m was 0.44 /mM/s toward succinonitrile. This distinct characteristic might enable this nitrilase to be a potential candidate for industrial applications for biosynthesis of carboxylic acid.

• Korean Journal of Adult Nursing
• /
• v.19 no.4
• /
• pp.547-555
• /
• 2007

Purpose: The purpose of this study was to test a hypothetical model of health-related quality of life in patients with heart failure. The hypothetical model was derived from the Wilson and Cleary's model, the Rector's model, and published research findings. Methods: Data from 103 patients with heart failure were analyzed to determine the best multivariate health-related quality of life model given variables derived from the prior studies. The statistics programs SPSS 12.0 and LISREL 8.7 program were used for descriptive statistics and covariance structure analysis respectively. Results: The overall fitness of the path final model was good(GFI=.97, AGFI=.95, NNFI=1.06, NFI=.96, p=.96). Symptoms were directly affected by gender. HYHA Class was directly affected by only gender. Physical functioning limitation was directly affected by exercise. Health perception was directly affected by economics, symptom, and physical functioning limitation. Depression was directly affected by exercise and health perception. Heath-related quality of life was directly affected by physical functioning limitation and depression, indirectly affected by gender, economics, exercise, symptoms, NYHA Class, and health perception. This path analysis model explained 51% of health-related quality of life in patients with heart failure. Conclusion: To improve of health-related quality of life with heart failure patients, it is necessary to make nursing interventions for physical functioning and depression.

• Korean Journal of Occupational Health Nursing
• /
• v.26 no.2
• /
• pp.114-123
• /
• 2017

Purpose: This study aimed to explore personal as well as occupational factors and health status associated with work-life balance in Korean registered nurses. Methods: This study was a secondary data analysis using cross-sectional nationally representative data from the Korean Working Conditions Survey (KWCS) in 2014. Study participants included 450 registered nurses in South Korea. Descriptive analysis, Independent t-test, $x^2$ test, and Logistic regression analyses were performed using the SPSS 21.0 statistical program. Results: Work-life balance was reported in 70.6% individuals with 85.7% being male and 70.0% being female nurses. Logistic regression analysis revealed that being male good health state, having less than 40-hour working week, lower number of night duty, policy on flexible work arrangement were significant predictors of work-life balance. Conclusion: This study provided evidence that identify predictors of work-life balance in registered nurses in South Korea. Therefore, we need the actively support health care service promotion and prevention for work-life balance predictors.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.33 no.4
• /
• pp.296-309
• /
• 2009

Thick-walled cylinder with high pressure have had wide application in the armament industry. In the thick-walled cylinder, fatigue crack is generated at inner radius and developed toward the outer radius. To prevent generation of fatigue crack, the autofrettage process had been used. The compressive residual stress induced by the autofrettage process extends loading pressure and fatigue life of the thick-walled cylinder. In this study, the residual stress of single and compound cylinder by the autofrettage process was evaluated. The analytical compressive residual stress of single cylinder was good agreement with experimental result at inner radius. The analysis on the residual stress of compound cylinder was conducted. The compressive residual stress at inner radius was increased with the overstrain level. And fatigue life of the compound cylinder with initial crack was evaluated. The considered initial crack shape was straight and semi-elliptical. The fatigue life was extended with the overstrain level. The fatigue life of the compound cylinder with semi-elliptical crack was longer than straight crack. The suitable way to extend fatigue life of the compound cylinder was proposed.