Detection of fiber waviness in CFRP using eddy current method

Abstract(#br)In this paper, a method of detecting fiber waviness in carbon fiber reinforced polymer (CFRP) using eddy current (EC) probe is proposed. The probe consists of a rectangular excitation coil and a rectangular reception coil that are perpendicular to each other. The excitation coil is along the designed fiber direction. Fiber waviness changes the direction of EC and generates a magnetic field component that is normal to the reception coil; thereby an output signal is obtained. The results of simulation and experiments show that the resolution of testing fiber direction using the proposed method is as small as 0.5° and fiber waviness can be detected according to the variation of scanning signal

Job burnout and associated influencing factors in employees of 7 research and development enterprises in Minhang District of Shanghai

BackgroundJob burnout is an early mental health condition caused by job stress and contributes to many negative effects on work and life. Employees of research and development (R&D) enterprises are exposed to constant pressure from innovation, production speed and sales expansion, and they are prone to burnout symptoms if such factors are not under effective control. ObjectiveTo evaluate the current situation of job burnout among employees of R&D enterprises in Minhang District of Shanghai and explore its influencing factors. MethodsDuring November to December 2021, a cross-sectional study was developed and a convenient sampling method was used to enroll employees from 7 R&D enterprises in Minhang District of Shanghai. On the basis of voluntary participation with informed consent, a survey was conducted by using a self-made questionnaire (collecting data about general demographic characteristics, occupational characteristics, behavior and lifestyle), the Chinese version of the Concise Occupational Stress Questionnaire, and the Chinese version of the Maslach Burnout Inventory-General Survey. Occupational stress and its dimensions (job demand, job control, and social support) were divided into high, medium, and low levels according to tertiles. The positive rate of job burnout was reported according to score categorization (<1.5 refers to no job burnout, ≥1.5 refers to job burnout, where ≥1.5 and <3.5 refer to mild and moderate job burnout, and ≥3.5 refers to severe job burnout). Potential influencing factors of job burnout were evaluated by using one-way ANOVA, chi-square test, forward stepwise regression, and non-conditional binary logistic regression (α=0.05, two-sided test). ResultsA total of 3153 subjects were enrolled and 3014 samples were included in the analysis, with a valid response rate of 95.6%. Among the included subjects, 888 (29.46%) reported no job burnout, 1775 (58.89%) reported mild to moderate job burnout, and 351 (11.64%) reported severe job burnout. The mean of total job burnout score was 2.17±1.12, and the dimentional mean scores were 2.78±1.61 for emotional exhaustion, 1.60±1.60 for cynicism, and 4.05±1.57 for diminished personal accomplishment. Varied categories of sex, age, marital status, working position, sleep status, job demand, job control, and social support groups of workers resulted in significant differences in job burnout score. Compared with the low job demand group, the positive rate of job burnout was elevated in the medium and high job demand groups; the risk of job burnout in the medium job demand group was 1.42 (95%CI: 1.04-1.94) times higher, and that in the high job demand group was 2.64 (95% CI : 2.17-3.22) times higher versus the low job demand group. The risk of job burnout in the medium job control group was 1.35 (95%CI: 1.06-1.72) times higher versus the low job control group. Compared with the low social support group, job burnout was less reported in the other groups, and the OR (95%CI) values of the medium and high social support groups were 0.41 (0.31-0.53) and 0.15 (0.12-0.19) respectively. ConclusionThe rate of reporting positive job burnout in R&D enterprises is high, which deserves sufficient attention. Relieving work pressure, increasing job control and social support, and maintaining adequate sleep are helpful to reduce job burnout

Mediating effect of sleep quality on the association between job stress and health-related productivity loss among workers in R&D enterprises in Shanghai

BackgroundPast research indicates that occupational stress negatively predicts health-related productivity. Simultaneously, sleep problem among workers may stem from job stress, subsequently leading to a decline in sleep quality and resulting in reduced health productivity. Therefore, this study aims to idenitify whether the sleep quality of employees functions as a mediator in the process through which job stress impacts health productivity.ObjectivesThis study aimed to assess the status and analyze differences in quality of sleep, job stress, and health-related productivity loss (HRPL) among workers in research and development (R&amp;D) enterprises in Minhang District, Shanghai. We also assessed the mediating effect of sleep quality on the relationship between job stress and HRPL.MethodsA total of 3,216 workers in R&amp;D firms aged between 18 and 60 years participated in this study (mean age 35.15 years; standard deviation 8.44; male-to-female ratio≈2:1). The Nakata Insomnia Questionnaire, the Chinese version of the Brief Job Stress Questionnaire revised edition, and the Chinese version of the Work Productivity and Activity Impairment Questionnaire were used in this study. And the Kruskal–Wallis test, Hierarchical Multiple Regression Analysis, and Path Analysis were utilized for data analysis in this study.ResultsThere were significant differences in the positive detection rate of insomnia among participants according to age, educational level, marital status, position, length of service, and level of financial difficulties (all P &lt; 0.05). We also found significant differences in the positive detection rate of HRPL among participants according to age, marital status, length of service, and level of financial difficulties (all P &lt; 0.05); participants with insomnia scored higher for HRPL than those without insomnia (6.00 vs. 4.20, P &lt; 0.001). Additionally, participants with job stress problems had higher HRPL than those without these issues (7.00 vs. 4.20, P &lt; 0.001). Our findings suggest that sleep quality plays a mediating role between job stress and HRPL (all P &lt; 0.05).ConclusionsOccupational health professionals must pay particular attention to job stress, sleep quality, and their influencing factors to positively influence the wellbeing of workers while improving productivity

Characteristics of Eddy Current Attenuation and Thickness Measurement of Metallic Plate

Abstract(#br)In eddy current testing, the law of attenuation of eddy current (EC) is of great concern. In conductive half space under the excitation of uniform magnetic field, the EC density decreases exponentially in the depth direction. However, in conductor with finite thickness tested by coil, the distribution of EC in the depth direction is more complicated. This paper studies the characteristics of EC attenuation in metallic plate of finite thickness. Simulation results show that there is an EC reflection at the bottom of plate, which changes the law of EC attenuation. A new concept, namely the equivalent attenuation coefficient, is proposed to quantify the speed of EC attenuation. The characteristics of EC attenuation are utilized to explain the nonmonotonic relation between coil..

Depressive symptoms, social support, and health-related quality of life: A community-based study in Shanghai, China

BackgroundDepressive symptoms erode both physical and mental aspects of health-related quality of life (HRQoL). Social support (SS) may improve HRQoL through its direct effects or buffering effects. The association among depressive symptoms, SS, and HRQoL has been studied in specific groups, but research in the general adult population remains limited. This study examined the association among depressive symptoms, SS, and HRQoL, including exploring whether SS (including its three dimensions: subjective SS, objective SS and support utilization) mediated or moderated the relationship between depressive symptoms and HRQoL among community-based adults.MethodsWe conducted a cross-sectional survey in six communities in Shanghai, China, and 1642 adult participants with complete information on depressive symptoms and/or SS, and HRQoL were included. Linear regression analysis was used to investigate the association among depressive symptoms, SS, and HRQoL. In addition, we explored the mediating and moderating role of SS in the relationship between depressive symptoms and HRQoL.ResultsMore depressive symptoms were associated with lower physical HRQoL (B = −0.64, p < .001) and lower mental HRQoL (B = −0.83, p < .001). SS (B = 0.07, p = .02), specifically subjective SS (B = 0.09, p = .03), was positively related to mental HRQoL. After adjusting for covariates, we found no evidence for a mediating role of SS in the relationship between depressive symptoms and HRQoL, while SS (subjective SS and objective SS) moderated the association between depressive symptoms and mental HRQoL.LimitationsDue to the low voluntary participation rate of employees, participants represented approximately 50% of the individuals approached, thus limiting the generalizability of our findings. Data collected through self-report scales could lead to information bias.ConclusionsSS does not appear to underlie the relationship between depressive symptoms and HRQoL. However, interventions to increase SS (in particular, subjective SS and objective SS) should be studied to determine whether they may be beneficial in alleviating the adverse impact of depressive symptoms on mental HRQoL

Effects of a mutual recovery intervention on mental health in depressed elderly community-dwelling adults: a pilot study

BackgroundThe prevalence of depression in the elderly is growing worldwide, and the population aging in China makes depression a major health problem for the elderly adults and a tremendous burden to the society. Effective interventions should be determined to provide an approach solving the problem and improving the situation. This study examined the effectiveness of a mutual recovery program intervention on depressive symptom, sleep quality, and well-being in community-dwelling elderly adults with depressive symptom in Shanghai.MethodsRecruitment was performed between July 2012 and August 2012. Using a cluster randomized wait-list controlled design, we randomized 6 communities (n = 237) into either the intervention group (3 communities, n = 105) or to a wait-list control group (3 communities, n = 132). All participants met the inclusion criteria for depression, which were defined by The Geriatric Depression Scale (GDS-15). From March to May of 2013, participants in the intervention group underwent a 2-month mutual recovery program intervention. The intervention included seven 90-min, weekly sessions that were based on a standardized self-designed schedule. Depression was used as primary outcome at three measurement moments: baseline (T1), before intervention at 24 weeks (T2), and immediately after intervention at 32 weeks (T3). Well-being and sleep quality were used as the secondary outcomes, and were evaluated based on the WHO-5 Well-being Index (WHO-5) and the Self-administered Sleep Questionnaire (SSQ). Finally, a total of 225 participants who completed all the sessions and the three measurements entered the final analysis. Mixed-model repeated measures ANOVAs were performed to estimate the intervention effects.ResultsThere was no significant difference in gender, marriage, age structure, post-work type, and education background between the intervention and control group at baseline. Multivariate ANOVAs showed that there was no significant difference within the groups in terms of sleep, well-being, and depression at baseline and before the intervention. Mixed-model repeated measures ANOVAs detected a group × time interaction on depression, sleep, and well-being and showed a favorable intervention effect within groups immediately after the intervention.ConclusionsThe mutual recovery program could be a creative and effective approach to improve mental health in older community-dwelling adults with depressive symptom

Structural architectures of polymer proton exchange membranes suitable for high-temperature fuel cell applications

High-temperature proton exchange membrane (HT-PEM) fuel cells offer more advantages than low-temperature PEM fuel cells. The ideal characteristics of HT-PEMs are high conductivities, low-humidity operation conditions, adequate mechanical properties, and competitive costs. Various molecular moieties, such as benzimidazole, benzo-thiazole, imide, and ether ether ketone, have been introduced to polymer chain backbones to satisfy the application requirements for HT-PEMs. The most common sulfonated polymers based on the main chain backbones have been employed to improve the rties. Side group/chain engineering, includ crosslinking, has been widely applied to HT-PEMs to further improve their proton conductivity, thermal stability, and mechanical properties. Currently, phosphoric acid-doped polybenzimidazole is the most successful polymer material for application in HT-PEMs. The compositing/blending modification methods of polymers are effective in obtaining high PA-doping levels and superior mechanical properties. In this review, the current progress of various membrane materials used for HT-PEMs is summarized. The synthesis and performance characteristics of polymers containing specific moieties in the chain backbones applied to HT-PEMs are discussed systemically. Various modification approaches and their deficiencies associated with HT-PEMs are analyzed and clarified. Prospects and future challenges are also presented

The roles of health culture and physical environment in workplace health promotion: a two-year prospective intervention study in China

Abstract Background To understand the potential influencing factors on the effectiveness of workplace health promotion interventions and examine whether workplace health culture and physical environment can mediate the relationship between workplace health promotion and intervention effectiveness. Methods A total of 719 participants from 10 Chinese government agencies were recruited for a prospective self-controlled trial. Questionnaires, qualitative interviews, and direct observation were used for the baseline evaluation, process evaluation, and effectiveness evaluation. Based on the results of the need assessment and risk assessment at each workplace, a two-year comprehensive health intervention was conducted by each workplace. Health outcomes including self-rated health (SRH) and mental health were measured at baseline and 24 months. Health culture was measured at 24 months. Physical environment and intervention implementation were measured at 12 months and 24 months. Results Compared with the baseline, the means of SRH and mental health increased significantly by 0.302 and 2.698, respectively. The SRH scores were different before and after intervention; furthermore, the differences varied by workplace. Health culture mediated the relationship between intervention implementation and intervention effectiveness, including SRH and mental health improvement, but physical environment did not. Physical environment quality was significantly negatively correlated with SRH improvement and mental health improvement. Under the relatively high-quality interventions with scores higher than 4.047 or 4.151 (out of 5), better health culture may led to greater SRH and mental health improvements. Conclusions Health culture may mediate the relationship between intervention implementation and intervention effectiveness, whereas physical environment does not seem to mediate this relationship. Under relatively high-quality interventions, a better health culture may lead to more positive improvements in SRH and mental health. Future studies will need to examine the physical environment as a moderating effect rather than mediating effect. Trial registration This study was retrospectively registered in Chinese Clinical Trial Registry. Trial registration number: ChiCTR-OOC-16010059. Date of registration: Dec 1, 2016

The “Dark Side” Effects of Social Capital on Harmful Drinking among Chinese Community Residents: A Multilevel Study

Background: To determine the effects of social capital on harmful drinking (HD) among Chinese community residents using a multilevel study. Methods: A cross-sectional study conducted from 2017&ndash;2018. In total, 13,610 participants were randomly interviewed from 29 districts of 3 cities in China with a multi-stage sampling procedure. Social capital, including social cohesion, membership in social organizations, and frequency of social participation, were assessed using validated scales. HD was assessed using the CAGE four-item questionnaire. Multilevel models were developed to determine whether social capital was related to HD when socioeconomic and demographic covariates were controlled. Results: In general, the prevalence of HD was 8.18%, and more specifically, 13.77% for men and 2.74% for women. After controlling for covariates and stratifying by gender, compared to residents in the low individual-level membership of social organizations, we found that the odds ratio (OR) for HD was 1.30 with a 95% confidence interval (CI) of 1.07&ndash;1.56 among men and 1.95 (95% CI: 1.29&ndash;2.97) among women. Compared to residents in the low individual-level frequency of social participation groups, the odds ratio of HD among women was 1.58 (95% CI: 1.10&ndash;2.26). There was no association between district-level social capital and HD. Conclusions: A high level of social capital may promote HD among the residents of Chinese neighborhoods. Intervention to modify social capital under the Chinese drinking culture may help reduce HD