In situ characterization of work hardening and springback in grade 2 α-titanium under tensile load

Plastic effects during sheet metal forming can lead to undesirable distortions in formed components. Here, the three-stage work hardening and plastic strain recovery ("springback") in a cold-rolled, α-phase commercially pure titanium is examined. Interrupted standard tensile tests with in situ x-ray diffraction and quasi-in situ electron backscatter diffraction show that twinning plays a minor role in both of these phenomena. The experiments give evidence that the observed work hardening plateau is the result of an abrupt activation and multiplication of 〈c+a〉 slip and a subsequent redistribution of load between grain families. The springback can be attributed to inelastic backwards motion and annihilation of dislocations, driven by backstresses from dislocation-based hardening during loading. The peak broadening behavior, observed by x-ray diffraction, suggests that the internal stress state is highest in the rolling direction, resulting in consistently higher springback magnitude along this direction

In situ tension-tension strain path changes of cold-rolled Mg AZ31B

The mechanical behavior of cold-rolled Mg AZ31B is studied during in-plane multiaxial loading and tension-tension strain path changes performed on cruciform samples using in situ neutron diffraction and EBSD. The results are compared with uniaxial tension loading of dogbone-shaped samples measured with in situ neutron diffraction and acoustic emission. The activity of slip and twinning mechanisms and the active twin variants are discussed for the different strain paths. It is shown that initial strains of 4–5% cause a strengthened yield stress during reload for strain path change angles of 90 and 135°. The strengthening is primarily due to dislocation accumulation during the initial load impeding dislocation motion during the reload. The twinning observed during the prestrain activates complex multivariant secondary twinning which may also contribute to the strengthening in the reload

In situ uniaxial pressure cell for x-ray and neutron scattering experiments

We present an in situ uniaxial pressure device optimized for small angle x-ray and neutron scattering experiments at low-temperatures and high magnetic fields. A stepper motor generates force, which is transmitted to the sample via a rod with an integrated transducer that continuously monitors the force. The device has been designed to generate forces up to 200 N in both compressive and tensile configurations, and a feedback control allows operating the system in a continuous-pressure mode as the temperature is changed. The uniaxial pressure device can be used for various instruments and multiple cryostats through simple and exchangeable adapters. It is compatible with multiple sample holders, which can be easily changed depending on the sample properties and the desired experiment and allow rapid sample changes

Perceived Parenting and Adolescent Cyber-Bullying: Examining the Intervening Role of Autonomy and Relatedness Need Satisfaction, Empathic Concern and Recognition of Humanness

Due to the progress in information technology, cyber-bullying is becoming one of the most common forms of interpersonal harm, especially among teenagers. The present study (N = 548) aimed to investigate the relation between perceived parenting style (in terms of autonomy support and psychological control) and cyber-bullying in adolescence. Thereby, the study tested for the intervening role of adolescent need satisfaction (i.e., autonomy and relatedness), empathic concern towards others, and adolescents' recognition of full humanness to cyber-bullying offenders and victims. Findings revealed both a direct and an indirect relation between parenting and cyber-bullying. More specifically, parental psychological control directly predicted cyber-bullying, whereas parental autonomy support related to less cyber-bullying indirectly, as it was associated with the satisfaction of adolescents' need for autonomy, which predicted more empathic concern towards others, which in turn differentially related to recognition of humanness to victims and bullies. The discussion focuses on the implications of the current findings

Self-evaluation as a tool in developing environmental responsibility

The purpose of the paper is to share the findings of an action research project aimed at exploring the impact of transformative pedagogies on pre-service teachers following an environmental education programme (EEP), offered by the University of Malta. Assessment and evaluation practices of environmental education (EE) and education for sustainable education (ESD) programmes tend to cater just for knowledge content and skills, usually failing to target the development of attitudes and values that promote sustainable lifestyles. The EEP was specifically designed to target the development of pro-environmental values by actively involving students in their learning mainly and providing opportunities for reflection and self-evaluation. The paper analyses qualitative research data obtained from evaluation questionnaires about every study unit in the programme; reflective questionnaires drawing upon the studentsí reflective journals; a focus group interview and in depth one-to-one interviews with individual students. The paper provides studentsí evaluations about the course design and effectiveness that should provide insights for course developers and evaluators seeking to develop EE/ESD programmes that address individual needs through learner centred pedagogies.peer-reviewe

Identification of safety effects of infrastructure related measures, Deliverable 5.2 of the H2020 project SafetyCube

Identification of safety effects of infrastructure related measures, Deliverable 5.2 of the H2020 project SafetyCub