Cation insertion to break the activity/stability relationship for highly active oxygen evolution reaction catalyst

The production of hydrogen at a large scale by the environmentally-friendly electrolysis process is currently hampered by the slow kinetics of the oxygen evolution reaction (OER). We report a solid electrocatalyst α-Li2IrO3 which upon oxidation/delithiation chemically reacts with water to form a hydrated birnessite phase, the OER activity of which is five times greater than its non-reacted counterpart. This reaction enlists a bulk redox process during which hydrated potassium ions from the alkaline electrolyte are inserted into the structure while water is oxidized and oxygen evolved. This singular charge balance process for which the electrocatalyst is solid but the reaction is homogeneous in nature allows stabilizing the surface of the catalyst while ensuring stable OER performances, thus breaking the activity/stability tradeoff normally encountered for OER catalysts

The medicalization of current educational research and its effects on education policy and school reforms

Este artículo parte del supuesto de la aparición de una cultura pedagogizada durante los últimos 200 años, según la cual los problemas sociales percibidos se traducen en desafíos educativos. En consecuencia, tanto la investigación como las instituciones educativas crecieron, y una política educativa surgió como resultado de las negociaciones entre los profesionales, los investigadores y los responsables políticos. El documento mantiene que algunas experiencias específicas ocurridas durante la Segunda Guerra Mundial, provocaron un cambio fundamental en el papel social y cultural de los círculos académicos, que condujo a una cultura tecnocrática caracterizada por una mayor confianza mostrada hacia los expertos en lugar de a la práctica profesional (es decir, los maestros y administradores). Bajo este cambio tecnocrático, en primer lugar surgió un sistema tecnológico de razonamiento, que luego fue sustituido por un “paradigma” médico. El nuevo paradigma condujo a una medicalización de la investigación social, en el cual se da por sentado un particular entendimiento organicista de la realidad social, y su investigación se realiza bajo las más discutibles premisas. El resultado es que pese a la creciente importancia de la investigación en general, este cambio expertocrático y médico de la investigación social dio lugar a una reducción drástica de las oportunidades reformistas al privar a las partes interesadas de una amplia gama de investigación educativa, experiencia profesional, sentido común, y debate político.This paper starts from the assumption of the emergence of an educationalized culture over the last 200 years according to which perceived social problems are translated into educational challenges. As a result, both educational institutions and educational research grew, and educational policy resulted from negotiations between professionals, researchers, and policy makers. The paper argues that specific experiences in the Second World War triggered a fundamental shift in the social and cultural role of academia, leading up to a technocratic culture characterized by confidence in experts rather than in practicing professionals (i.e., teachers and administrators). In this technocratic shift, first a technological system of reasoning emerged, and it was then replaced by a medical “paradigm.” The new paradigm led to a medicalization of social research, in which a particular organistic understanding of the social reality is taken for granted and research is conducted under the mostly undiscussed premises of this particular understanding. The result is that despite the increased importance of research in general, this expertocratic and medical shift of social research led to a massive reduction in reform opportunities by depriving the reform stakeholders of abroad range of education research, professional experience, common sense, and political deliberation.Grupo FORCE (HUM-386). Departamento de Didáctica y Organización Escolar de la Universidad de Granad

A Peer Help System for Workplace Training

: Informal peer help networks, where workers help one another with tasks, are common in many workplaces. In this paper we present a practical approach for just-in-time workplace training that uses artificial intelligence techniques to extend informal peer help networks to a broader scale. We have developed a system called PHelpS that is a situated, peer-supported, AI-based approach to training in procedural, task-oriented domains. PHelpS supports workers as they perform their tasks, offers assistance in finding peer helpers when required, and mediates communication on task-related topics. Presently we are running pilot-tests of PHelpS with our client organization to ensure that the system adheres to the organizational policies and procedures, that it will be accepted by workers, and that it is sufficiently robust and effective for wider scale deployment. The system opens up new research avenues for further exploration of AI-based training systems and computer-supported collaborative le..

Myocardial And Peripheral Vascular Responses To Behavioral Challenges And Their Stability In Black And White Americans

The purpose of this study was to assess the short term stability of myocardial and peripheral vascular responses to behavioral challenges, and to compare the response patterns of Black and White men. Blood pressure and heart rate, as well as stroke volume, cardiac output, total peripheral resistance, and systolic time interval measures derived from the impedance cardiogram were obtained in 12 Black and 12 White men. These measures were taken prior to and during an evaluative speech stressor, a mirror star tracing task, and a forehead cold pressor test presented during two laboratory sessions scheduled two weeks apart. In general, total peripheral resistance and impedance-derived baseline measures showed acceptable reproducibility (G greater than .85). With a few exceptions, adequate reliability was also demonstrated for change (delta) scores. All tasks raised blood pressure responses above resting levels. Blacks demonstrated significantly greater increases in total peripheral resistance responses across tasks. Whites but not Blacks also revealed increases above baseline in cardiac output and contractility as estimated by the Heather Index. These findings are consistent with the view that Blacks show greater vascular responsiveness than Whites across a variety of tasks, but reveal less myocardial responsiveness