Prediction of stress-strain behaviors in steels using an integrated constitutive, FEM and ANN model

Austenitic steels with a carbon content of 0.0037 to 0.79 wt% C are torsion tested and modeled using a physically based constitutive model and an Integrated Phenomenological and Artificial neural Network (IPANN) model. The prediction of both the constitutive and IPANN models on steel 0.017 wt% C is then evaluated using a finite element (FEM) code ABAQUS with different reduction in the thickness after rolling through one roll stand. It is found that during the rolling process, the prediction accuracy of the reaction force from FEM simulation for both constitutive and IPANN models depends on the strain achieved (average reduction in thickness). By integrating FEM into IPANN model and introducing the product of strain and stress as an input of the ANN model, the accuracy of this integrated FEM and IPANN model is higher than either the constitutive or IPANN model.

The effect of low cycle fatigue, ratcheting and mean stress relaxation on stress-strain response and microstructural development in a dual phase steel

This study examines the cyclic plastic deformation behavior and microstructural development of a dual phase steel in both symmetric and asymmetric cycling in strain and stress control modes. The low-cycle fatigue (LCF) and mean stress relaxation (MSR) tests show very similar fatigue lifetimes. However, fatigue lifetimes reduce and prominent accumulation of directional strain was observed in ratcheting. A microstructural analysis has revealed that the type of cyclic test carried out has a noticeable impact on the substructural development, and this has been correlated with differences in accumulated tensile strain. Electron backscatter diffraction investigation has shown larger in-grain misorientation for ratcheting specimen in comparison with LCF and MSR specimens. The orientation of ferrite grains was found to have very little effect on their substructural development, and strain localization commonly occurred in the ferrite at the ferrite/martensite interface.

Predictors of job strain and intention to quit in a reorganised Australian workforce

This study examined the role of working conditions in predicting the psychological health, job satisfaction, organisational commitment and intention to quit of employees working in an industry sector that had undergone large-scale organisational change. The working conditions were assessed using an augmented job strain model- whereby job demand, job control and social support had been augmented by industry-specific stressors - and the psychological contract model. The results of regression analyses indicate that social support was predictive of all of the outcome measures. Job control and the honouring of psychological contracts were both predictive of job satisfaction and commitment, Furthermore, job satisfaction and organisational commitment were found to mediate the relationship between working conditions and intention to quit. Collectively, these findings suggest that strategies aimed at combating the negative effects of organisational change could be enhanced by addressing several variables represented in the models - particularly social support, job control and psychological contracts.

Using job strain and organizational justice models to predict multiple forms of employee performance behaviours among Australian policing personnel

The overall purpose of this investigation was to examine the relationship between stress-related working conditions and three forms of employee performance behaviours: in-role behaviours, citizenship behaviours directed at other individuals and citizenship behaviours directed at the organization. The potentially stressful working conditions were based on the job strain model (incorporating job demands, job control and social support) as well as organizational justice theory. A sample of Australian-based police officers (n = 640) took part in this study and the data were collected via a mail-out survey. Multiple regression analyses were undertaken to assess both the strength and the nature of the relationships between the working conditions and employee performance and these analyses included tests for additive, interactional and curvilinear effects. The overall results indicated that a significant proportion of the explained variance in all three outcome measures was attributed to the additive effects of demand, control and support. The level of variance associated with the organizational justice dimensions was relatively small, although there were signs that specific dimensions of justice may provide unique insights into the relationship between job stressors and employee performance. The implications of these and other notable findings are discussed.

International perspectives on psychosocial working conditions, mental health, and stress of dairy farm operators

Dairy farm operators-farmers, workers, and family members-are faced with many demands and stressors in their daily work and these appear to be shared across countries and cultures. Dairy operators experience high psychosocial demands with respect to a hard work and production ethos, economic influences, and social and environmental responsibility. Furthermore, both traditional and industrial farms are highly dependent on external conditions, such as weather, fluctuating markets, and regulations from government authorities. Possible external stressors include disease outbreaks, taxes related to dairy production, and recent negative societal attitudes to farming in general. Dairy farm operators may have very few or no opportunities to influence and control these external conditions, demands, and expectations. High work demands and expectations coupled with low control and lack of social support can lead to a poor psychosocial work environment, with increased stress levels, ill mental health, depression, and, in the worst cases, suicide. Internationally, farmers with ill mental health have different health service options depending on their location. Regardless of location, it is initially the responsibility of the individual farmer and farm family to handle mental health and stress, which can be of short- or long-term duration. This paper reviews the literature on the topics of psychosocial working conditions, mental health, stress, depression, and suicide among dairy farm operators, farm workers, and farm family members in an international perspective.

Comparison of brood size and juvenile weight between a blue strain and normal-coloured strains of the Australian freshwater crayfish Cherax Destructor Clark (Decapoda: Parastacidae)

A blue strain of the yabby Cherax destructor albidus was compared to two normal-coloured strains of C. d. destructor and C. d. albidus for brood size and juvenile weight. Reproductive performance of the blue strain was found to be significantly poorer than the two normal-coloured strains. Similarly, the weight of newly independent juveniles was also found to be significantly lower for the blue strain. No differences were detected between the two normal-coloured strains in either reproductive performance or size of newly independent juveniles. The phenotypic differences between the blue strain and normal-coloured strains are most likely genetic. However, further studies are needed to investigate whether these differences are due to pleiotropy or inbreeding effects.

Understanding ring strain and ring flexibility in six - and eight-membered cyclic organometallic group 14 oxides

A simple model was developed for the approximation of ring strain energies of homo- and heterometallic, six- and eight-membered cyclic organometallic group 14 oxides and the degree of puckering of their ring conformations. The conformational energy of a ring is modelled as the sum of its angular strain components. The bending potential energy functions for the various endocyclic M–O–M′ and O–M–O linkages (M, M′=Si, Ge, Sn) were calculated at the B3LYP/(v)TZ level of theory using H3MOM′H3 and H2M(OH)2 as model compounds. For the six-membered rings, the minimum total angular contribution to ring strain, ERSGmin was calculated to decrease in the order: cyclo-(H2SiO)3 (13.0 kJ mol−1)>cyclo-H2Sn(OSiH2)2O (7.0 kJ mol−1)>cyclo-H2Ge(OSiH2)2O (4.9 kJ mol−1)>cyclo-H2Si(OSnH2)2O (3.4 kJ mol−1)>cyclo-(H2SnO)3 (1.7 kJ mol−1)>cyclo-H2Si(OGeH2)2O (0.8 kJ mol−1)≈cyclo-H2Ge(OSnH2)2O (0.7 kJ mol−1)>cyclo-H2Sn(OGeH2)2O (0.1 kJ mol−1)≈cyclo-(H2GeO)3 (0 kJ mol−1). All of the six-membered rings were predicted to adopt (nearly) planar conformations (a=0.996<a<1). By contrast, all eight-membered rings were predicted to adopt strainless, but puckered conformations. The degree of puckering was predicted to increase in the order: cyclo-(H2SiO)4 (a=0.983)<cyclo-H2Sn(OSiH2O)2SiH2 (a=0.959)<cyclo-(H2SiO)2(H2SnO)2 (a=0.942)< cyclo-H2Si(OSnH2O)2SiH2 (a=0.935)<cyclo-(H2SnO)4 (a=0.916)<cyclo-(H2GeO)4 (a=0.885). The differences in ring strain and the degree of puckering were linked to the different electronegativities of Si, Ge and Sn. The results obtained are consistent with experimental ring strain energies; reactivities towards ring opening polymerizations or ring expansion reactions and observed ring conformations of cyclic organometallic group 14 oxides.

Depression, anxiety and stress in women following acute coronary syndrome: implications for secondary prevention

Objective
To document incidence of depression, anxiety, and stress in women more than 6 months following an acute coronary syndrome.

Design
Participants were identified from a coronary care unit database. The Depression Anxiety Stress Scales 21 (DASS 21) was sent to potential participants via postal survey.

Setting
A metropolitan teaching hospital in Melbourne, Australia.

Participants
The cohort of women was aged between 55 and 70 years. They had been admitted to hospital with a diagnosis of acute coronary syndrome (ACS) between 6 and 14 months prior to participating in this study.

Main outcome measures
Scores on Depression, Anxiety, and Stress Scale (DASS 21).

Results
Of the 117 posted questionnaires, 39 women with a mean age of 63 (S.D. 4.97) responded to the survey, representing a response rate of 33.3%. Most participants scored within normal levels of depression (66.7%), anxiety (60.5%), and stress (70.3%), however, mild to extremely severe levels of each construct (33.4%, 39.6%, and 29.7%, respectively) were found.

Conclusions
The reporting of elevated levels of depression, anxiety and stress in a subset of women more than 6 months following an ACS event underscores the importance of ongoing screening for risk factors impacting on psychological well-being and the inclusion of this information in education and counseling strategies in both the inpatient and outpatient settings. Based on these pilot data, consideration of a screening system in the immediate post discharge period for women at risk and an education or support service are recommended.

The origin of ring strain and conformational flexibility in Tri- and Tetrasiloxane Rings and their heavier group 14 congeners

Never change a winning team. Since the appearance of the first volume in 1994 this series has become a well respected forum, and like its highly successful predecessors, this sixth volume again brings together leading experts from academia and industry to provide a comprehensive and critical survey of the frontiers of current industrial and university research. - Synthesis and characterization of new organosilicon compounds - Applications in polymer and materials science - Summary of the latest research results The result is a unique compendium with two volumes of first-hand information, vital for all experts working in this field.

Using job strain and psychological contract theories to predict employee wellbeing in a reformed public sector agency

This study investigates the Issues that contribute to employee wellbeing in a public sector agency having undergone substantial reform The research is based on a model that is initially demand-oriented, and is expanded to incorporate psychological contract breach and organisational justice. Hierarchical regression analyses were conducted on the 1,010 completed surveys The results confirm the value of the Job strain model (JSM) and that the inclusion of breach and fairness were worthwhile extensions of the JSM Future research may wish to extend this approach and incorporate more of the social aspects of the work situation m studies of employee wellbeing.

Yoga as a preventative and treatment for depression, anxiety and stress

With the dual aims of better understanding the contribution of Yoga to positive mental health and exploring links between yogic philosophy and psychological theory, researchers at Deakin University in Melbourne, Australia, conducted a study on Yoga as a preventative and treatment for symptoms of mental illness. The Yoga classes were designed as a six-week program incorporating breathing techniques (prânâyâma), exercises for strength, vitality, and flexibility (âsanas), guided relaxation (yoga-nidrâ), and meditation. The aim of this process was to enhance self-awareness, encourage the perspective that emotional states are somewhat transient, and encourage a self-accepting and calm attitude through concentrating on synchronizing gentle movements and breathing. By developing calmness, selfacceptance, a balanced perspective, and enhanced concentration it was hypothesized that participants in the six-week Yoga program would strengthen their resistance to emotional distress. Psychometric testing was carried out to assess symptoms of stress, anxiety, and depression across three groups: regular Yoga practitioners, beginners entering the program, and people who did not practice Yoga, and these tests were re-administered after six weeks. In addition, a strong sense of intrinsic spiritual experience has been cited as a possible buffer to stress, anxiety, and depression and has been associated with decreased frequency of medical symptoms. All participants were therefore also assessed on their sense of intrinsic spirituality, but not on religious beliefs. At the end of six weeks, the Yoga beginners group showed lower average levels of symptoms of depression, anxiety, and stress than at commencement, but levels were stable for regular Yoga practitioners and people who did not practice Yoga. In addition, beginners showed growth in their self-reported level of intrinsic spiritual experience.