Artificial neural networks and physical modeling for determination of baseline consumption of CHP plants

An effective modeling technique is proposed for determining baseline energy consumption in the industry. A CHP plant is considered in the study that was subjected to a retrofit, which consisted of the implementation of some energy-saving measures. This study aims to recreate the post-retrofit energy consumption and production of the system in case it would be operating in its past configuration (before retrofit) i.e., the current consumption and production in the event that no energy-saving measures had been implemented. Two different modeling methodologies are applied to the CHP plant: thermodynamic modeling and artificial neural networks (ANN). Satisfactory results are obtained with both modeling techniques. Acceptable accuracy levels of prediction are detected, confirming good capability of the models for predicting plant behavior and their suitability for baseline energy consumption determining purposes. High level of robustness is observed for ANN against uncertainty affecting measured values of variables used as input in the models. The study demonstrates ANN great potential for assessing baseline consumption in energyintensive industry. Application of ANN technique would also help to overcome the limited availability of on-shelf thermodynamic software for modeling all specific typologies of existing industrial processes

Five decades of terrestrial and freshwater research at Ny-Ålesund, Svalbard

Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMFor more than five decades, research has been conducted at Ny-Ålesund, in Svalbard, Norway, to understand the structure and functioning of High-Arctic ecosystems and the profound impacts on them of environmental change. Terrestrial, freshwater, glacial and marine ecosystems are accessible year-round from Ny-Ålesund, providing unique opportunities for interdisciplinary obser-vational and experimental studies along physical, chemical, hydrological and climatic gradients. Here, we synthesize terrestrial and freshwater research at Ny-Ålesund and review current knowledge of biodiversity patterns, species population dynamics and interactions, ecosystem processes, biogeochemical cycles and anthropogenic impacts. There is now strong evidence of past and ongoing biotic changes caused by climate change, including negative effects on populations of many taxa and impacts of rain-on-snow events across multiple trophic levels. While species-level characteristics and responses are well under-stood for macro-organisms, major knowledge gaps exist for microbes, inverte-brates and ecosystem-level processes. In order to fill current knowledge gaps, we recommend (1) maintaining monitoring efforts, while establishing a long-term ecosystem-based monitoring programme; (2) gaining a mechanistic under-standing of environmental change impacts on processes and linkages in food webs; (3) identifying trophic interactions and cascades across ecosystems; and (4) integrating long-term data on microbial, invertebrate and freshwater com-munities, along with measurements of carbon and nutrient fluxes among soils, atmosphere, freshwaters and the marine environment. The synthesis here shows that the Ny-Ålesund study system has the characteristics needed to fill these gaps in knowledge, thereby enhancing our understanding of High-Arctic ecosystems and their responses to environmental variability and chang

Traumatic brain injury in pedestrian–vehicle collisions: Convexity and suitability of some functionals used as injury metrics

Background and Objective: Abrupt accelerations or decelerations can cause large strain in brain tissues and, consequently, different forms of Traumatic Brain Injury (TBI). In order to predict the effect of the accelerations upon the soft tissues of the brain, many different injury metrics have been proposed (typically, an injury metric is a real valued functional of the accelerations). The objective of this article is to make a formal and empirical comparison, in order to identify general criteria for reasonable injury metrics, and propose a general guideline to avoid ill-proposed injury metrics. Methods: A medium-size sample of vehicle-pedestrian collisions, from Post Mortem Human Subject (PMHS) tests, is analyzed. A statistical study has been conducted in order to determine the discriminant power of the usual metrics. We use Principal Component Analysis to reduce dimensionality and to check consistency among the different metrics. In addition, this article compares the mathematical properties of some of these functionals, trying to identify the desirable properties that any of those functionals needs to fulfill in order to be useful for optimization. Results: We have found a pair-wise consistency of all the currently used metrics (any two injury metrics are always positively related). In addition, we observed that two independent principal factors explain about 72.5% of the observed variance among all collision tests. This is remarkable because it indicates that despite high number of different injury metrics, a reduced number of variables can explain the results of all these metrics. With regard to the formal properties, we found that essentially all injury mechanisms can be accounted by means of scalable, differentiable and convex functionals (we propose to call minimization suitable injury metric to any metric having these three formal properties). In addition three useful functionals, usable as injury metrics, are identified on the basis of the empirical comparisons. Conclusions: The commonly used metrics are highly consistent, but also highly redundant. Formal minimal conditions of a reasonable injury metric have been identified. Future proposals of injury metrics can benefit from the results of this study.Peer ReviewedPostprint (author's final draft

Forgetting complex propositions

This paper uses possible-world semantics to model the changes that may occur in an agent's knowledge as she loses information. This builds on previous work in which the agent may forget the truth-value of an atomic proposition, to a more general case where she may forget the truth-value of a propositional formula. The generalization poses some challenges, since in order to forget whether a complex proposition $\pi$ is the case, the agent must also lose information about the propositional atoms that appear in it, and there is no unambiguous way to go about this. We resolve this situation by considering expressions of the form $[\boldsymbol{\ddagger} \pi]\varphi$, which quantify over all possible (but minimal) ways of forgetting whether $\pi$. Propositional atoms are modified non-deterministically, although uniformly, in all possible worlds. We then represent this within action model logic in order to give a sound and complete axiomatization for a logic with knowledge and forgetting. Finally, some variants are discussed, such as when an agent forgets $\pi$ (rather than forgets whether $\pi$) and when the modification of atomic facts is done non-uniformly throughout the model

Characterization of ageing resistant transparent nanocrystalline yttria-stabilized zirconia implants.

The "Window to the Brain" is a transparent cranial implant under development, based on nanocrystalline yttria-stabilized zirconia (nc-YSZ) transparent ceramic material. Previous work has demonstrated the feasibility of this material to facilitate brain imaging over time, but the long-term stability of the material over decades in the body is unknown. In this study, the low-temperature degradation (LTD) of nc-YSZ of 3, 6, and 8 mol % yttria is compared before and after accelerated ageing treatments following ISO standards for assessing the ageing resistance of zirconia ceramics. After 100 hr of accelerated ageing (equivalent to many decades of ageing in the body), the samples do not show any signs of phase transformation to monoclinic by X-ray diffraction and micro-Raman spectroscopy. Moreover, the mechanical hardness of the samples did not decrease, and changes in optical transmittance from 500 to 1000 nm due to ageing treatments was minimal (below 3% for all samples), and unlikely to be due to phase transformation of surface crystals to monoclinic. These results indicate the nc-YSZ has excellent ageing resistance and can withstand long-term implantation conditions without exhibiting LTD

Optimal electromagnetic energy extraction from transverse galloping

A fully coupled electro-fluid-elastic model for electromagnetic energy harvesting from Transverse Galloping is presented here. The model considers a one degree-of-freedom galloping oscillator where fluid forces are described resorting to quasi-steady conditions; the electromagnetic generator is modelled by an equivalent electrical circuit where power is dissipated at an electrical load resistance; the galloping oscillator and the electromagnetic model are coupled appropriately. Two different levels of simplification have been made depending on the comparison between the characteristic electrical and mechanical timescales. The effect of the electrical resistance load on the energy harvested is studied theoretically. For fixed geometry and mechanical parameters, it has been found that there exists an optimal electrical resistance load for each reduced velocity. On the practical side, this result can be helpful to design tracking-point strategies to maximize energy harvesting for variable flow velocity conditions

Enhanced mechanical energy extraction from transverse galloping using a dual mass system

This paper offers a theoretical study of energy extraction through transverse galloping using a dual-mass system. To this end, a two-degree-of-freedom model is developed where fluid forces on the galloping body are described resorting to quasi-steady hypothesis; the model is solved approximately by using the Harmonic Balance Method. Three possible configurations of the dual-mass system have been analyzed. Two of them show an improvement in the efficiency of energy extraction with respect to that of the single mass configuration when the mechanical properties of the dual-mass system are appropriately chosen. In addition, the dual-mass system promotes a broadening of the values of the incident flow velocities at which the efficiency is kept high

Educación en cosnumo ético y agroecológico. Hacia la soberanía alimentaria pro comunidad de la vida

En éste libro se han reunido una serie de trabajos de investigación que posibilitan la reflexión e idealmente, el cambio en los propios hábitos de consumo. Es por ello que las y los autores, académicos investigadores de la Universidad Autónoma del Estado de México, Corporación Universitaria Minuto de Dios (Colombia), Universidad Complutense de Madrid y la Universidad de Granada (ambas de España), presentan distintos enfoques relacionados con el consumo responsable, como el decrecimiento, los estudios de Paz y la ética No-violenta, la filosofía del cuidado, la Carta de la Tierra, y la soberanía alimentaria, a través de reflexiones teóricas y experiencias resultantes del esfuerzo y el trabajo en el que se han comprometido intelectual y activamente para que, a través de la educación formal, no formal e informal se involucre a los actores que con su voz y su sabiduría nos ayuden a conectar de nuevo con la Naturaleza para actuar con conciencia en aras de nuestra propia supervivencia y la de todos los seres vivos. Invito a la población lectora a que iniciemos el periplo hacia el campo de las posibilidades, aquellas que nos dan la esperanza de vivir en un mundo más justo y más humano, desde una visión Biocéntrica que busca integrar a toda la comunidad de la vida.Resumen No se puede obviar el consumismo orquestado por las grandes industrias, que ha sido tan perfecto su trabajo que la humanidad aletargada camina consumiendo directo hacia el magno ecocidio autosuicida. Y surgen las preguntas ¿Dónde está la ética? ¿Qué papel juega la universidad en todo esto? ¿Aún se está a tiempo de recuperar la salud y la justicia para toda la comunidad de la vida? Aprender a discernir entre lo que es bueno, lo que es justo y lo que mejor conviene a nuestra civilización como la fracción aparentemente más sabia de la comunidad de la vida, es un indicador de la evolución del pensamiento crítico y de un sentido de responsabilidad compartida al que cada persona debiera aspirar. Los temas que se abordan son: Capítulo I La academia y su aporte a la sostenibilidad: promoción de los mercados agroecológicos y el consumo responsable Adriana María Chaparro Africano Capítulo II Educación universitaria en consumo ético no-violento y soberanía alimentaria. Hacia una calidad de vida planetaria Hilda Carmen Vargas Cancino y Lucía M. Collado Medina Capítulo III El comercio justo y agroecológico como alternativa pedagógica universitaria. Hacia la soberanía alimentaria en la Facultad de Odontología David Eduardo Velázquez Muñoz Capítulo IV La conexión con la Comunidad de la Vida. Una estrategia didáctica desde la interiorización Alfonso Fernández-Herrería Capítulo V Buena práctica: Seminario -Taller para un consumo ético. Estrategia didáctica múltiple y de promoción en la Universidad Inmaculada Gómez-Jarabo y Bienvenida Sánchez Alba Capítulo VI El consumo responsable como centro de una ética basada en la libertad y la solidaridad María del Rosario Guerra González y Nancy Caballero Reynaga Capítulo VII Dignidad humana: fundamento ético de la dignidad de la Tierra Virginia Pilar Panchi VanegasSin patrocinadore