Intercalation events visualized in single microcrystals of graphite.

The electrochemical intercalation of layered materials, particularly graphite, is fundamental to the operation of rechargeable energy-storage devices such as the lithium-ion battery and the carbon-enhanced lead-acid battery. Intercalation is thought to proceed in discrete stages, where each stage represents a specific structure and stoichiometry of the intercalant relative to the host. However, the three-dimensional structures of the stages between unintercalated and fully intercalated are not known, and the dynamics of the transitions between stages are not understood. Using optical and scanning transmission electron microscopy, we video the intercalation of single microcrystals of graphite in concentrated sulfuric acid. Here we find that intercalation charge transfer proceeds through highly variable current pulses that, although directly associated with structural changes, do not match the expectations of the classical theories. Evidently random nanoscopic defects dominate the dynamics of intercalation

Publisher Correction: Intercalation events visualized in single microcrystals of graphite.

The Peer Review File associated with this Article was updated shortly after publication to redact confidential comments to the editor

Enterprise placements: factors which support learning and prolonged attainment in students

This article investigates the learning and academic attainment of undergraduate education students on enterprise placement projects in a longitudinal mixed methods study. By observing the placement learning and analysing previous and subsequent attainment of a second and third year group it adds to the ontology of purpose for enterprise in education and concurs with the growing body of work identifying placements with sustained academic improvement. The qualitative investigation identifies five key learning factors from the placements which support improved academic attainment. These are: pressure to learn; critical personal learning events; seeing the setting as a learning environment; professional attachments, and having space to learn. These factors support the transfer of learning from one context or situation to another and using concepts of transformative learning (Mezirow 2000; Jones, Matlay, and Harris 2012) or transitional learning (Illeris 2007) contributes to a cycle of increasing self-esteem and motivation and a sustained improvement in academic attainment. It concludes that a praxis curriculum, using self-assessments, continuous short (micro) reflections and taught awareness of the placement as a place to look for and recognise learning, would underpin these five factors and contribute to the academic processes underpinning attainment

The effects of child abuse and race on risk-taking in male adolescents.

This study explores the effects of abuse on the risk-taking behaviors of 2973 black and white adolescent males, 412 of whom were sexually or physically abused. Surveys on mental and physical health, risk-taking behaviors and attitudes, and family living were administered to 9th and 12th graders in an urban midwestern state. The surveys included questions on past history of sexual and physical abuse. More black than white males reported experiencing incest, extrafamilial sexual abuse, and physical abuse. As for outcome risk-taking behaviors, blacks were more likely to use illegal substances, run away, skip school, attempt suicide, force partners into sex, and commit violent acts; however, the racial effects decreased when abuse histories were taken into consideration. Whites were more likely to drink and drive, and to drink before having sex; abuse history did not decrease this racial effect. Abuse but not race was predictive of drinking and of having serious drinking problems. The results point to the importance of pediatricians, psychologists, and other healthcare workers, as well as those in the legal and criminal justice system screening for a history of abuse among adolescents who demonstrate these or other risk-taking behaviors

Publisher Correction: Intercalation events visualized in single microcrystals of graphite

The Peer Review File associated with this Article was updated shortly after publication to redact confidential comments to the editor