Impedance analysis of electrolyte processes in a solid oxide cell

Electrochemical impedance spectroscopy and the distribution of relaxation times are powerful tools to study polarization processes in solid oxide cells (SOC). Commonly the measured polarization resistance is solely attributed to polarization phenomena in the electrodes whereas the electrolyte is assumed to act as purely ohmic series resistance. In this study an electrolyte supported SOC is investigated by impedance spectroscopy from the nominal operating temperature range of 700–900°C down to temperatures as low as 350°C. At such low temperatures the dielectric polarization of the electrolyte is shifted into the accessible frequency range, providing access to additional processes which are deconvoluted and quantified. It is discussed to which extent the additional layers like gadolinia doped ceria diffusion barrier and electrode layers influence the electrolyte processes as grain and grain boundary

Estructuración de situaciones problemáticas en ausencia de datos claros

En el presente trabajo se aborda la estructuración de un problema de gestión de personal, en una empresa que se dedica al outsourcing de servicios de informática (la organización ofrece personal especializado a empresas que necesitan realizar desarrollos informáticos). Para dicha estructuración, se implementa la denominada SoftSystemMethodology (SSM), conforme al planteo de Georgiou (2006, 2008), una metodología inscripta dentro de la Investigación Operativa Blanda. SSM reconfigurada pretende alcanzar tres objetivos claves para la toma de decisiones: producir conocimiento del contexto de la situación problemática, utilizar dicho conocimiento para la definición rigurosa del problema y diseñar un plan de acción sistémico para la resolución del mismo. El artículo recoge definiciones y opiniones sobre la complejidad y la incertidumbre en los sistemas actuales y justifica la necesidad de utilizar un enfoque multi-metodológico para su análisis. Explica los fundamentos de SSM y de las mejoras utilizadas en este trabajo. Además analiza con cierto detalle un ejemplo de aplicación y destaca las virtudes de este enfoque metodológicoFil: Cabrera, Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Zanazzi, José Luis. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Fil: Castellini, Alejandra. Universidad Nacional de Salta. Facultad de Ingeniería; Argentina.Fil: Salamon, Alicia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Otras Ingenierías y Tecnología

Procesos drv: la toma de decisiones como entrenamiento para equipos de trabajo

Este artículo presenta un método orientado a facilitar la toma de decisiones en equipos de trabajo. La propuesta utiliza herramientas de la Teoría de Utilidad Multiatributo, combinadas con Estadística. El artículo contiene una revisión de contribuciones al problema de la decisión con múltiples decisores, y una reflexión sobre características y requerimientos de las prácticas grupales. Además, se describen los fundamentos conceptuales del método. Se  enumeran y explican los pasos necesarios para su aplicación. El método se ejemplifica con la capacitación de un equipo responsable por el desarrollo de un sistema de mantenimiento preventivo. En ésta y otras experiencias, la propuesta resultó motivadora, con buen nivel de logros y amplia colaboración de los participantes. Esta contribución se diferencia de otros aportes, porque visualiza el proceso de toma de decisiones como una interesante posibilidad de capacitación grupal y, por ello, orienta su estrategia a posibilitar el intercambio de conocimientos, afianzar liderazgos, aumentar la cohesión interna y favorecer el compromiso con la decisión adoptada.This paper presents a method designed to facilitate group decision making. The proposal relies on tools of the Multiattribute Utility Theory combined with Statistics. The article contains a review of contributions to the problem of multiple decision makers and a reflection on the characteristics and requirements of group practices. It describes the conceptual foundations of the method and it also identifies and explains the steps needed for implementation. The method is exemplified with the training of a team responsible for the development of a preventive maintenance system. In this and other experiences, the proposal was motivating, with good level of achievements and ex-tensive collaboration of the participants. This contribution differs from others because it considers the decision making process as an interesting possibility for group training and therefore gears its strategy to enable knowledge exchange, strengthen leadership, improve internal cohesion and foster commitment to the adopted decision

The Extragalactic Background Light Absorption Feature in the Blazar Component of the Extragalactic Gamma-ray Background

High-energy photons from cosmological emitters suffer attenuation due to pair production interactions with the extragalactic background light (EBL). The collective emission of any high-energy emitting cosmological population will exhibit an absorption feature at the highest energies. We calculate this absorption feature in the collective emission of blazars for various models of the blazar gamma-ray luminosity function (GLF) and the EBL. We find that models of the blazar GLF that predict higher relative contributions of high-redshift blazars to the blazar collective spectrum result in emission that is more susceptible to attenuation by the EBL, and hence result in more prominent absorption features, allowing for better differentiation amongst EBL models. We thus demonstrate that observations of such an absorption feature will contain information regarding both the blazar GLF and the EBL, and we discuss tests for EBL models and the blazar GLF that will become possible with upcoming Fermi observations.Comment: 9 pages, 2 figures, emulateapj format, to be published in Astrophysical Journa

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation