Modelling of crack initiation in adhesively bonded joints

In this paper, a review of some techniques proposed in the literature for modelling crackinitiation in adhesively bonded joints is presented. The techniques reviewed are: a) the singular intensityfactor, b) the inherent flaw size, c) Cohesive-zone model (CZM) and d) Continuum Damage Mechanics(CDM). The singular intensity factor characterizes the stress singularity at the corner point and can beused as a failure criterion to predict crack initiation. The inherent flaw method technique assumes that asmall crack having a fraction of millimetres is initiated at the singular point in order to develop a fracturemechanics criterion for crack initiation. The strain energy release rate for an un-cracked specimen is usedto determine the size of the inherent flaw. The cohesive zone model (CZM) technique is based ondefining parameters from fracture mechanics test specimens and using them to model failure of the joints.Continuum Damage Mechanics makes use of thermodynamics principles in order to derive a damageevolution law. In this damage evolution law the damage variable (D) is expressed as a function of numberof cycles, applied stress range and triaxiality function. Furthermore, the possibility of using the eXtendedFinite Element Method (XFEM) to predict crack initiation is elaborated

The relationship between non-standard work arrangements and injuries in Europe

Abstract Background: Non-standard work arrangements are becoming an increasingly important determinant of health and safety among workers. The main objective of this study is to examine the relationship between indicators of non-standard work arrangements including precarious contract, long working hours, multiple jobs, shift work, and occupational injuries, using a representative European sample and taking into account several sociodemographic and work characteristics. Methods: The study was based on the data of the fifth European Working Conditions Survey (EWCS). For the purpose of this analysis, the sample was restricted to 26839 respondents from the 27 countries of the European Union, who were all employed workers. Associations between non-standard work arrangements and occupational injuries were studied with multilevel modeling techniques while adjusting for several confounders. Results: About 8.44% of the workers suffered from an occupational injury. Multivariate regression model showed an increased injury risk for those working long hours (OR 1.29, 95% CI 1.15 - 1.44), having multiple jobs (OR 1.23, 95% CI 1.03 - 1.47) and shift work (OR 1.35, 95% CI 1.18 - 1.54). The relationship between contract type and occupational injuries was not significant (OR 0.91, 95% CI 0.78 - 1.07). No significant gender difference was observed. Conclusion: This study confirms that indicators of non-standard work arrangements, except for precarious contract type, were significantly associated with occupational injuries. To reduce the burden of occupational injuries, not only risk reduction strategies and interventions are needed but also policy efforts at European level should be undertaken to limit non-standard work arrangements

Shift work and occupational accident absence in Belgium : findings from the sixth European Working Condition Survey

(1) Background: Irregular and non-standard work arrangements have become a serious determinant to the health and safety of workers. The aim of this study is to investigate the relationship between shift work and occupational accident absence. A representative Belgian sample considering several sociodemographic and work characteristics is used. (2) Methods: This study is based on the data of the sixth European Working Condition Survey (EWCS). The sample is restricted to 2169 respondents from Belgium. By using multivariate logistic regression modeling techniques and adjusting several confounders, the associations between shift work and occupational accident absence are studied. (3) Results: It is found that about 11.1% of the workers undergo an occupational accident absence. A multivariate regression model demonstrates an increased occupational accident absence risk for workers who have shift work (odds ratio, or OR, 1.92, 95% CI 1.06-3.46). Also, gender and biomechanical exposure were significantly associated with occupational accident absence ((OR 2.07, 95% CI 1.16-3.69) and (OR 2.03, 95% CI 1.14-3.63), respectively). No significant interaction effects are found with gender and age variables. (4) Conclusion: This study confirms that doing shift work is significantly associated with occupational accidents. In order to reduce the significance of occupational accidents, shift work should be limited through national-level policies

Occupational injuries: a comparison between temporary and permanent workers. Findings from the fifth European working condition survey

Objective: although the effect of occupation or employment status on health and safety is notable, there are few studies on the effect of precarious employment on occupational injuries. We compared work injuries and harm in precarious workers and their non-precarious counterparts using a representative European sample. Method: a total of 28853 workers (5863 temporary and 22990 permanent; average age 35 and 41 for temporary and permanent workers respectively) were surveyed by means of the fifth European working condition survey. Employment types consisted of permanent employment and four forms of non-standard work employment: fixed-term contract, temporary employment agency contract, an apprenticeship or other training scheme and no contract. Occupational injury was measured by asking whether the participant had an injury on the job in the past 12 months and causing physical injury to others was measured by asking whether the participants’ mistake on the job will cause physical injury to other workers? To investigate the relationships between employment types, and occupational injury, causing physical injury to other workers, multilevel logistic regression tests were conducted. Results: employees with precarious work were more likely to suffer from occupational injuries (OR 1.13, 95% confidence interval 1.01 – 1.26), and causing less harm to a coworker (OR 0.91, 95% confidence interval 0.85 – 0.97) than employees with non-precarious work. After controlling for age, gender (Model 2) and working conditions (Model 3), compared with unadjusted model, men, those working long hours, those who experience multiple jobs and those working at high speed were found to be risk factors of occupational injuries and causing harm to a coworker. Conclusion: The current study indicated that temporary workers had a higher risk of occupational injuries than permanent employees. Indeed, this study is the first to examine the relations between types of employment and occupational injuries for all 27 member states of the European Union. Our study highlights the need to protect and improve the occupational safety of non-standard workers in EU27

Knowledge, Attitude and Practice of Hepatitis B Virus Infection among Dental Students and Interns in Saudi Arabia

Hepatitis B virus (HBV) is a worldwide healthcare problem. Dental health care professionals are at a high risk of infection by HBV. The present study investigated the knowledge, attitude and practice of HBV infection among Saudi dental students and Interns in Saudi Arabia. This was a questionnaire-based cross-sectional study. A self-administered questionnaire consisting of questions on students? knowledge, attitudes, and practices regarding HBV was used. Data of 420 participants were analyzed using SPSS (Statistical Package for Social Studies) version 22.0. The response rate was 84%. Overall, the participants showed fair level of knowledge about HBV, with significant differences between final year students and the interns. Also, the subjects showed negative attitude toward HBV patients. The vast majority reported always wearing gloves (97.9%), gowns (92.1%), face masks (89.2%), disposable caps (87.1%) and protective eye wear (80.9%). The majority of participants (91.4%) had been vaccinated against HBV. However, only 41% completed the recommended 3 doses of the vaccine. These unsatisfactory findings emphasize the necessity of continued education about HBV in order to improve knowledge, attitudes, and practices of dental students and Interns regarding HBV

This House believes that considering the continuous quarantine and precautionary measures should be of a priority over lifting the restrictions to avoid the negative economic and social consequences

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Work accident victims : a comparison between non-standard and standard workers in Belgium

Background: The fast growth of non-standard employment in developed countries highlights the importance of studying the influence of contract type on worker's safety and health. Objective: The main purpose of our study is to investigate whether non-standard workers are more injured than standard workers or not. Additionally, other risk factors for occupational accidents are investigated. Methods: Data from the Belgian surveys on work ability in 2009 and 2011 are used. During their annual occupational health examination, workers were asked to fill in a self-administered questionnaire. In total, 1886 complete responses are collected and analyzed using logistic regression. Results: Temporary workers did not have higher injury rates than permanent workers [OR 0.5, 95% confidence interval 0.2-1.2]. Low-educated, less-experienced workers and those exposed to dangerous conditions are more frequent victims of occupational accidents. Conclusion: The present data do not support the hypothesis that non-standard workers have more injuries than standard workers. Our results about occupational accidents derived from a non-representative sample of the Belgian workforce and cannot be generalized due to the heterogeneity in job organization and labor regulations between countries. Further research is needed to extend our findings and to seek other factors that may be associated with work accidents