• Title/Summary/Keyword: Stress improvement

Search Result 1,789, Processing Time 0.029 seconds

Development of New Code Case "Mitigation of PWSCC and CISCC in ASME Code Section III Components by the Advanced Surface Stress Improvement Technology (일차수응력부식균열(PWSCC) 및 염화이온부식균열(CISCC) 저감용 표면개질기술 적용을 위한 코드케이스 개발)

  • Cho, Sungwoo;Pyun, Youngsik;Mohr, Nick;Tatman, Jon;Broussard, John;Collin, Jean;Yi, Wongeun;Oh, Eunjong;Jang, Donghyun;Koo, Gyeong Hoi;Hwang, Seong Sik;Choi, Sun Woong;Hong, Hyun UK
    • Transactions of the Korean Society of Pressure Vessels and Piping
    • /
    • v.15 no.1
    • /
    • pp.28-32
    • /
    • 2019
  • In nuclear power plant operation and spent fuel canisters, it is necessary to provide a sound technical basis for the safety and security of long-term operation and storage respectively. Recently, the peening technology is being discussed and the technology will be adopted to ASME Section III, Division 1, Subsection NX (2019 Edition). The peening is prohibited in current edition, but it will be approved in 2019 Edition and adopted. However, Surface stress improvement techniques such as the peening is used to mitigate SCC susceptible in operating nuclear plants. Although the peening will be approved to ASME CODE, there are no performance criteria listed in the 2019 edition. The Korean International Working Group (KIWG) formed a new Task Group named "Advanced Surface Stress Improved Technology". The task group will develop a CODE CASE to address PWSCC(Primary Water Stress Corrosion Cracking) and CISCC(Chloride Induced Stress Corrosion Cracking) for new ASME Section III components. TG-ASSIT was started to make peening performance criteria for ASME Section III (new fabrication) applications. The objective of TG-ASSIT is to gain consensus among the relevant Code groups that requirements/mitigation have been met.

State of the Science: Salivary Biomarker Utilization for Stress Research

  • An, Kyungeh;Starkweather, Angela;Sturgill, Jamie;Kao, Hsueh-Fen S.;Salyer, Jeanne
    • Perspectives in Nursing Science
    • /
    • v.11 no.2
    • /
    • pp.87-93
    • /
    • 2014
  • Purpose: The use of salivary biomarkers for stress research is increasing based on the convenience of collection, affordability and scientific merit. This short review provides an overview of the state of the science of salivary biomarkers utilized in research related to stress. Methods: An integrative review was conducted. Results: The trend of utilizing salivary biomarkers in stress research was reviewed, specifically, focusing on the use of endocrine and inflammatory biomarkers incorporated in previous stress research. Then, a review of sampling procedures for salivary biomarkers and the analytic methods is provided. Finally, a discussion on the strengths and areas for improvement in the use of salivary biomarkers in stress research is included. Conclusion: Salivary biomarkers as an alternative to blood biomarkers are increasingly being recognized as a legitimate source for analyzing the stress response in humans.

A Study of Stress Factors Experienced by the Hospitalized Patients (입원이 불안감(Stress)으로서 환자에게 미치는 영향에 관한 일 연구)

  • 최옥신
    • Journal of Korean Academy of Nursing
    • /
    • v.5 no.1
    • /
    • pp.93-111
    • /
    • 1975
  • As the hospitalized patients will be facing new stress situation due to change of his environment from home to hospital it will be very important to understand the psychological stress experienced by hospital patients not only for helping patients in the process of recovery from illness but also fulfil1ing the objective of comprehensive nursing care by understanding the needs of the patients. There is no doubt that it would be very helpful for treatment of patients as well as for improvement of nursing care if we know more about psychological needs of patients and give them adequate support to meet these needs. The study to find out the causes and degree of stress events experienced by hospitalized patients, with the objective of instituting improvement of nursing care program based on the needs of patients, was conducted during the month of September 1974 with 60 patients randomly selected from those admitted to medical and surgical wards at Yonsei Medical Center in that period The questionnaire form included 36 questions which are considered to be stress events for hospital patients, and was devide into five areas namely, such events related to 1) disease itself, 2) hospital environment, 3) nursing care and treatment, 4) communication and human relations, and 5) family and economic problems. The results of the study were as follows: 1. It was confirmed that hospitalization considered to be a stress producing factor and most patients perceived the admission to hospital as a stress factor. 2. According to the rating scale, it was found that degree of perceived stress shows a variation according to the source of stress producing event. 3. No significant differences in the mean values were observed statistically with the perceived stress levels according to demographic and other variables of patients related to hospitalization. 4. Among the questions related to disease itself, "Admission for surgery" was perceived most frequently as a stress event (97.14%) by patients. 5. With regard to the questions related to hospital environment, "death of the patient room-mate" was the most serious stress event perceived by patients (90%) and "living with hospital regulations"was considered to be less serious stress event (23.33%). 6. As for the questions related to nursing care and treatment, "limitation of freedom" was perceived as a stress factor most frequently (70.91%) by the patients and "worry for wrong treatment" turned out to be less frequent stress event (50.0%). 7. As for the questions related to communication and human relations, "difficulty to meet doctors when wanted"appeared to be the most frequent stress event by the respondents (75.86%) , followed by "no explanation about treatment or examination"(75.0%) and "no explanation about nursing care procedures"(71.66%). 8. With regard 111 tile questions related to family and economic problems, "inadequate finances for family living due to hospitalization"and "high cost of hospitalization" were the most frequent cause of stress mentioned by the patients. (80.0%). 9. As a result of application of the stepwise regression analysis, it was found that about 89% was explained by those events associated with disease itself, hospital environment and family and economic problems. By adding those events related to "nursing care and treatment" and "communication and human relation", 100% of stress associated with hospitalization was explained.

  • PDF

Structural Analysis of Damping Hinge for Built-in Side-by-Side Refrigerator and Design Improvement of Bracket Pin to Reduce Stress Concentration (빌트인 양문형 냉장고 댐핑힌지의 구조해석 및 브래킷핀의 응력집중 저감을 위한 설계개선)

  • Lee, Boo-Youn
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.1
    • /
    • pp.373-379
    • /
    • 2020
  • This study performed stress and fatigue life analysis of the damping hinge of a built-in side-by-side refrigerator that occurs when the door is opened to the maximum angle. An analysis of the initial design showed that stress concentration occurred at the corner between the cylinder and upper disk of the bracket pin, and the maximum stress exceeded the yield strength. The maximum stress location and the calculated fatigue life were consistent with the door opening-and-closing endurance test results for a prototype. Three cases of design improvement for the bracket pin were derived with the aim of reducing the stress concentration that appeared in the initial design. An analysis of the cases showed that inserting a fillet between the disk and the cylinder of the bracket pin reduced the stress and increased the fatigue life. Moreover, changing the disk into two steps was more favorable. In conclusion, the best design improvement was the case that the disk was changed to two steps and the fillet with a large radius was inserted. In that case, the stress was the smallest and the fatigue life was infinite.

Mediating effect of Resilience for Life care in the Relationship between Stress Coping and Job Stress of 119 Emergency Medical Technicians (119 구급대원의 라이프 케어를 위한 스트레스 대처와 직무스트레스 간의 관계에서 극복력의 매개효과)

  • Kang, Da-Yeon;Lee, Hyo-Cheol;Ko, Dae-Sik
    • Journal of Korea Entertainment Industry Association
    • /
    • v.14 no.3
    • /
    • pp.463-473
    • /
    • 2020
  • This study was conducted to provide basic data to find measures to alleviate the job stress of 119 Emergency Medical Technicians by identifying the mediating effect of resilience for life care in the relationship between stress coping and job stress of 119 Emergency Medical Technicians. The data for this study were collected from October 5, 2019, to October 31, 2019. The subject was 205 119 Emergency Medical Technicians working in 119 safety centers located in G Metropolitan City. The collected data were analyzed by independent t-test, ANOVA, Scheffé test, Pearson's correlation coefficients, hierarchical multiple regression analysis, and Sobel test using the SPSS Statistics 21.0 program. As a result oh the study, The mediation effect of resilience was not statistically significant in the relationship between stress coping of seeking social support type and job stress; the mediation effect of resilience was not statistically significant in the relationship between stress coping of seeking positive thinking type and job stress. but, resilience was revealed that resilience completely mediates the relationship between problem-solving type and job stress, and partially mediates the relationship between avoidance type and job stress. The measures to reduce the job stress of 119 Emergency Medical Technicians derived from the above results are as follows. First, among the 119 Emergency Medical Technicians, problem-solving stress coping type 119 Emergency Medical Technicians need to reduce job stress through resilience improvement program. Second, avoidance stress coping type 119 Emergency Medical Technicians should take part in education programs that can reduce job stress in parallel with resilience improvement program.

Optimal Use of Stress Waves in Non-Intrusive Seismic Techniques for Geotechnical Applications

  • Joh, Sung-Ho
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2006.10a
    • /
    • pp.434-478
    • /
    • 2006
  • Stress waves have been used for geophysical and geotechnical applications for more than 50 years. The early-stage applications were simply based on travel-time measurements of stress waves and limited to site characterization. Currently stress-wave techniques are expanded to monitoring processes for grouting of damaged geotechnical structures, compaction of embankment, and deformational analyses for static geotechnical problems. Seismic techniques used to be good enough for rough estimators of engineering properties. Nowadays, the sophisticated modeling theory of stress-wave propagation substantially improved reliability and accuracy of the seismic techniques. In this paper, difficulties involved in currently available seismic techniques are discussed and analyzed. Herein some recently-developed non-intrusive seismic techniques, which make optimal use of stress waves for further improvement of reliability and accuracy, are also presented.

  • PDF

A Study of Fatigue Crack Growth in Shot Peened Spring Steel (쇼트피닝한 스프링강의 피로균열진전 연구)

  • Park, Keyung-Dong;Jin, Young-Beom
    • Journal of the Korean Society of Safety
    • /
    • v.19 no.4 s.68
    • /
    • pp.20-24
    • /
    • 2004
  • Antifatigue failure technology take an important the part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore in this paper the effect of compressive residual stress by shot peening on fatigue crack growth characteristics in stress ratio(R=0.1, 0.3, 0.6)was investigated with considering fracture mechanics. There is difference between shot peening specimen and unpeening specimen. Fatigue crack growth rate of shot peening specimen was lower than that of unpeening specimen. Fatigue lift shows more improvement in the shot peening material than in the unpeening material. And compressive residual stress of surface on the shot peening processed operate resistance force of fatigue crack propagation. That is the constrained force about plasticity deformation was strengthened by resultant stress, which resulted from plasticity deformation and compressive residual stress in the process of fatigue crack propagation.

The Evaluation and Relaxation of Residual Stress of Steel Cord (Steel Cord 선재의 판류응력 평가 및 완화에 관한 연구)

  • Lee, S.K.;Hwang, W.H.;Kim, B.M.;Bae, C.M.;Lee, C.Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2006.05a
    • /
    • pp.191-194
    • /
    • 2006
  • Recently the quality improvement of the steel cord product is demanded by the tire market. After wire drawing process, produced residual stresses have a harmful effect on the durability of the wire and become the cause which decreases the quality of the product. Therefore, to improve the quality of the steel cord product, the research regarding the method of residual stress relaxation is necessary. To evaluate the quality of the drawn wire, it is important to measure the residual stress, because the residual stress decides a variety of the quality level which is demanded in the drawn wire. This study proposed a residual stress relaxation method in the drawn wire using FE analysis. The validity of the analysis results was verified by nanoindentation test.

  • PDF