Neutron and X-ray diffraction studies and cohesive interface model of the fatigue crack deformation behavior

The crack-tip deformation behavior during a single overload, fatigue test of ferritic stainless steel, and Ni-based HAYNES 230 superalloy is studied at different structural levels using (1) neutron-diffraction, from which both the elastic-lattice strain and volume-averaged total dislocation densities are obtained, (2) polychromatic X-ray microdiffraction to probe the geometrically necessary dislocations and boundaries distribution, and (3) an irreversible and hysteretic cohesive interface model which has been implemented into a finite element framework to simulate the stress/strain evolution near the fatigue crack tip. Neutron strain measurements and finite element simulations are in qualitative agreement on the macroscopic length scale. Large plastic deformation induced by the overload and the resulting compressive residual strains are observed in front of the crack tip after the overload, and are the principal reason for the fatigue-crack-growth retardation. Strong strain gradients surrounding the crack propagation result in the formation of a high density of geometrically necessary dislocations near the fractured surface and cause local lattice rotations on the submicron level.     

Enhanced fatigue resistance of a nickel-based hastelloy induced by a surface nanocrystallization and hardening process

Improvements in the fatigue resistance of a nickel-based alloy have been achieved via a surface nanocrystallization and hardening (SNH) process. The enhanced fatigue resistance is related to the surface nanocrystallization, work hardening, and compressive residual stresses induced by the SNH process.     

Examining the Mechanisms Linking Transformational Leadership,Employee Customer Orientation,and Service Performance: The Mediating Roles of Perceived Supervisor and Coworker Support

Purpose  

The aim of this study is to test whether store-level transformational leadership influences service employees’ customer orientation via two different mechanisms—supervisor support and coworker support—and whether customer orientation leads to favorable customer-perceived employee service performance.     

Monozygotic twins with schizoform psychosis and hypothalamic-induced hypogonadotropic hypogonadism

It is reported about an uniovular male pair of twins which has been permanently hospitalized because of an intermittently progressing schizoform psychosis. A hypothalamically conditioned hypogonadotropic hypogonadism provable beyond that substantiates the possibility of the common causal genetic embodiment of both the clinical pictures which is disputed in literature.     

Transformational leadership and customer service: A moderated mediation model of negative affectivity and emotion regulation

Integrating theories from leadership, emotion management, affectivity, and customer service, this study examines how transformational leadership leads to favourable customer intentions via the mediation of service employees' emotion regulation, job satisfaction, and their service performance and via the moderation of employee negative affectivity. Results obtained from data of 204 matched sets of managers, service employees, and customers show that the effect of transformational leadership on amplification of pleasant emotions was conditioned on service employees' negative affectivity. Employee service performance partially mediated the effect of job satisfaction on customer outcomes. Finally, overall results reveal that transformational leadership and amplification of pleasant emotions were more strongly related to the customer outcomes, as mediated through the intervening variables in the model, when negative affectivity was high than when negative affectivity was low. Results have implications for how service workers with negative affectivity can manage their emotions to achieve effective service outcomes through interactions with a leader, how the effect of transformational leadership can be bounded, and how transformational leadership and emotion regulation are relevant to customer service.     

Exploring learners' self-efficacy, autonomy and motivation toward e-learning

A questionnaire survey was conducted with 116 college students (47 men, 69 women) in Central Taiwan to investigate predictive relationships among four attitudinal variables, perceived self-efficacy, learners' autonomy, intrinsic motivation, and extrinsic motivation toward e-learning. Analysis showed learners' autonomy was predictive of both intrinsic (57% independent variance explained) and extrinsic motivation (61% independent variance explained). Although perceived self-efficacy was not a predictor of intrinsic motivation and extrinsic motivation, it correlated significantly with extrinsic motivation.     

Early social attention impairments in autism: social orienting, joint attention, and attention to distress

This study investigated social attention impairments in autism (social orienting, joint attention, and attention to another's distress) and their relations to language ability. Three- to four-year-old children with autism spectrum disorder (ASD; n = 72), 3- to 4-year-old developmentally delayed children (n = 34), and 12- to 46-month-old typically developing children (n = 39), matched on mental age, were compared on measures of social orienting, joint attention, and attention to another's distress. Children with autism performed significantly worse than the comparison groups in all of these domains. Combined impairments in joint attention and social orienting were found to best distinguish young children with ASD from those without ASD. Structural equation modeling indicated that joint attention was the best predictor of concurrent language ability. Social orienting and attention to distress were indirectly related to language through their relations with joint attention. These results help to clarify the nature of social attention impairments in autism, offer clues to developmental mechanisms, and suggest targets for early intervention.