160 research outputs found

    Promoting energy efficiency at household level: a literature review

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    The household sector is one of the most energy-intensive sectors in Europe, and thus a focal point for reducing greenhouse gas emissions associated with energy consumption. Energy efficiency is considered a key measure to reduce household energy consumption, but several factors could lead to an underinvestment in energy efficiency. This is the so-called energy efficiency gap or paradox. The factors in question are grouped under market failures (including informational failures), behavioural failures and other factors. Various policies can be used to address these failures and promote the adoption of energy-efficient technologies, including energy standards and codes, economic incentives and information instruments. This paper reviews the empirical evidence to date on energy efficiency policies and discusses their effectiveness. On the one hand, command and control instruments seem to be effective policies, but they have to overcome several barriers. In the case of price instruments, subsidies and taxes do not seem to be effective while rebates present mixed results as they sometimes are effective and in other cases, they could present significant shortcomings. Finally, the effectiveness of informational policies is not always ensured as they depend on the country, sector and product category. Information feedback tools also seem to be effective as they work as a constant reminder of energy-efficient behaviour. Some limitations of energy efficiency policies are also identified, such as the difficulties of implementing codes and standards given that a minimum level need to be achieved, differences in the effectiveness of rebate programmes and non-conclusive results in regard to the effectiveness of monetary energy efficiency labels. © 2020, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.This study was conducted as part of the CONSumer Energy Efficiency Decision making (CONSEED) project, an EU-funded H2020 research project under grant agreement number 723741. This research is also supported by the Spanish State Research Agency through María de Maeztu Excellence Unit accreditation 2018-2022 (Ref. MDM-2017-0714). The project leading to these results has received funding from ‘la Caixa’ Foundation under the project SR0435 led by Ibon Galarraga. Amaya de Ayala also acknowledges the support of Fundación Ramon Areces under XVIII Concurso Nacional para la Adjudicación de Ayudas a la Investigación en Ciencias Sociales. Marta Escapa is grateful for financial support from the University of the Basque Country (Grant GIU18/136) and from the Spanish Ministry of Science, Innovation and Universities (Grant RTI2018-093352-B-I00)

    The theory of canonical perturbations applied to attitude dynamics and to the Earth rotation. Osculating and nonosculating Andoyer variables

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    The Hamiltonian theory of Earth rotation, known as the Kinoshita-Souchay theory, operates with nonosculating Andoyer elements. This situation parallels a similar phenomenon that often happens (but seldom gets noticed) in orbital dynamics, when the standard Lagrange-type or Delaunay-type planetary equations unexpectedly render nonosculating orbital elements. In orbital mechanics, osculation loss happens when a velocity-dependent perturbation is plugged into the standard planetary equations. In attitude mechanics, osculation is lost when an angular-velocity-dependent disturbance is plugged in the standard dynamical equations for the Andoyer elements. We encounter exactly this situation in the theory of Earth rotation, because this theory contains an angular-velocity-dependent perturbation (the switch from an inertial frame to that associated with the precessing ecliptic of date). While the osculation loss does not influence the predictions for the figure axis of the planet, it considerably alters the predictions for the instantaneous spin-axis' orientation. We explore this issue in great detail

    A First Assessment of the Corrections for the Consistency of the IAU2000 and IAU2006 Precession-Nutation Models

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    The Earth precession-nutation model endorsed by resolutions of each the International Astronomical Union and the International Union of Geodesy and Geophysics is composed of two theories developed independently, namely IAU2006 precession and IAU2000A nutation. The IAU2006 precession was adopted to supersede the precession part of the IAU 2000A precession-nutation model and tried to get the new precession theory dynamically consistent with the IAU2000A nutation. However, full consistency was not reached, and slight adjustments of the IAU2000A nutation amplitudes at the micro arcsecond level were required to ensure consistency. The first set of formulae for these corrections derived by Capitaine et al. (Astrophys 432(1):355–367, 2005), which was not included in IAU2006 but provided in some standards and software for computing nutations. Later, Escapa et al. showed that a few additional terms of the same order of magnitude have to be added to the 2005 expressions to get complete dynamical consistency between the official precession and nutation models. In 2018 Escapa and Capitaine made a joint review of the problem and proposed three alternative ways of nutation model and its parameters to achieve consistency to certain different extents, although no estimation of their respective effects could be worked out to illustrate the proposals. Here we present some preliminary results on the assessment of the effects of each of the three sets of corrections suggested by Escapa and Capitaine (Proceedings of the Journées, des Systémes de Référence et de la Rotation Terrestre: Furthering our Knowledge of Earth Rotation, Alicante, 2018) by testing them in conjunction with the conventional celestial pole offsets given in the IERS EOP14C04 time series.The four first authors were partially supported by Spanish Project AYA2016-79775-P (AEI/FEDER, UE)

    Integrative paleobotany: Affirming the role of fossils in modern plant biology - Introduction and dedication

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    If you are interested in plant evolution, try this quick exercise: take a phylogenetic tree of the plant kingdom, close your eyes, and point your finger randomly to a node of the phylogeny. Irrespective of the clade to which you are pointing, there is one thing you should know about it: the living representatives of that clade have evolved as a result of a long process in which failed attempts are the rule, and as a result, the diversity of extinct forms accumulated in the fossil record far exceeds that recorded in the extant flora. From this simple concept, Gar W. Rothwell made his career. Because of that, here is a second thing you should know about the plant clade to which you pointed at random: Gar has, more likely than not, contributed information about evolution in that clade at some point in his career. Gar was one of the principal contributors to the revival of paleobotany from a largely descriptive discipline to a vibrant field of investigation at the forefront of modern evolutionary sciences that contributes crucial insights into plant evolution, equal in importance to those provided by genetics and molecular biology. Because of this, the impact of Gar’s scientific contributions reaches far beyond the field of paleobotany, with important implications for wide areas of plant biology, including anatomy and morphology, development, systematics, phylogeny, and evolution. Gar earned a master’s degree in the laboratory of Thomas N. Taylor (University of Illinois at Chicago, 1966) studying Paleozoic seeds in the genus Conostoma (Rothwell and Eggert 1970; Rothwell 1971a). He subsequently earned his PhD degree in the laboratory of Wilson N. Stewart (University of Alberta, 1973), where he reconstructed the plants in the seed fern genus Callistophyton (Rothwell 1972b, 1975, 1980, 1981). His work was instrumental in ushering in studies of fossil plants as whole living organisms, looking at both structure and development. These early experiences launched Gar on a career in plant evolutionary biology that stretched over a half century, during which he occupied positions at the University of Alberta, University of London–Chelsea College, Ohio University, and Oregon State University. Throughout his career, Gar’s scholarly work and contributions have been recognized by numerous awards and honors: the Isabel Cookson Award, the Edgar T. Wherry Award, the Michael A. Cichan Award, the Merit Award of the Botanical Society of America, and honorary membership in the International Organization of Palaeobotany, where he served for 12 years as secretary-treasurer and president.Fil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tomescu, Alexandru M. F.. Humboldt State University. Department of Biological Sciences; Estados UnidosFil: Dunn, Michael T.. Cameron University. Department of Agriculture, Biology and Health Science; Estados UnidosFil: Stockey, Ruth A.. State University of Oregon; Estados Unido

    Bioelectrochemical enhancement of methane production from exhausted vine shoot fermentation broth by integration of MEC with anaerobic digestion

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    [ES] A microbial electrolysis cell integrated in an anaerobic digestion system (MEC-AD) is an efficient configuration to produce methane from an exhausted vine shoot fermentation broth (EVS). The cell worked in a single-chamber two-electrode configuration at an applied potential of 1 V with a feeding ratio of 30/70 (30% EVS to 70% synthetic medium). In addition, an identical cell operated in an open circuit was used as a control reactor. Experimental results showed similar behavior in terms of carbon removal (70–76%), while the specific averaged methane production from cycle 7 was more stable and higher in the connected cell (MECAD) compared with the unpolarized one (OCAD) accounting for 403.7 ± 33.6 L CH4·kg VS−1 and 121.3 ± 49.7 L CH4·kg VS−1, respectively. In addition, electrochemical impedance spectroscopy revealed that the electrical capacitance of the bioanode in MECAD was twice the capacitance shown by OCAD. The bacterial community in both cells was similar but a clear adaptation of Methanosarcina Archaea was exhibited in MECAD, which could explain the increased yields in CH4 production. In summary, the results reported here confirm the advantages of integrating MEC-AD for the treatment of real organic liquid waste instead of traditional AD treatment.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

    Estratigrafía y evolución geológica de la Cuenca de Cañadón Asfalto, Provincia del Chubut, Argentina

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    La Cuenca de Cañadón Asfalto, ubicada entre el Macizo Nordpatagónico y la Cuenca del Golfo San Jorge, presenta una importante columna de sedimentos jurásicos y cretácicos acumulados en hemigrábenes pertenecientes a un sistema de rift formado durante la fragmentación de Gondwana. La Cuenca de Cañadón Asfalto incluye varios depocentros sedimentarios denominados Gastre, Gan Gan, Fossatti, Valle de General Racedo, Gorro Frigio y Paso de Indios, limitados por bloques basamentales en zonas de transferencia. La columna sedimentaria jurásica y cretácica puede dividirse en tres megasecuencias principales (J 1, J 2 y K) separadas entre sí por discordancias de significado regional que se apoyan sobre un basamento de metamorfitas y granitoides del Paleozoico. La Megasecuencia J 1 está constituida por la Formación Las Leoneras, la Formación Lonco Trapial y la Formación Cañadón Asfalto, y su edad se extiende entre el HettangianoSinemuriano?/Pliensbachiano y el Bajociano tardío. Se acumuló en ambientes fluvial, lacustre y volcánico durante los estadíos incipiente a juvenil del rift. La Megasecuencia J 2 incluye sedimentos aluviales y lacustres continentales correspondientes a la Formación Cañadón Calcáreo, de edad oxfordiana-kimmeridgiana, que se depositaron en depocentros parcialmente coincidentes con los anteriores durante una reactivación tectónica multiepisódica del rift. Durante el Tithoniano tardío – Hauteriviano existe un importante hiato estratigráfico. Durante este lapso se generaron esfuerzos transpresivos-transtensivos con rotación de bloques a escala regional, que originaron levantamientos de grandes áreas de la cuenca y la subsecuente erosión de zonas extensas, aunque el entorno tectónico y su correspondiente campo de esfuerzos se encuentran aún en discusión. El posterior colapso de estas áreas elevadas, con un control tafrogénico inicial y una posterior subsidencia termal, permitió el desarrollo del espacio disponible para la acumulación de la Megasecuencia K, formada por los niveles continentales del Grupo Chubut del Barremiano-Campaniano, al cual le siguieron los depósitos marinos y litorales de las formaciones Paso del Sapo y Lefipán del CampanianoDaniano, representativos de la primera transgresión atlántica en la cuenca. Como consecuencia de los procesos detallados más arriba, una marcada discordancia angular separa a la base de la Megasecuencia K de todos los depósitos más antiguos de la cuenca. Posteriormente, durante el Paleoceno tardío-Eoceno, se produjo un episodio tectónico compresivo en el margen occidental de la cuenca, seguido por la acumulación del Complejo Volcánico y Piroclástico del Río Chubut Medio en ambientes de calderas asociadas a un vulcanismo de retro-arco. En el Oligoceno?- Mioceno a Reciente se produjo el levantamiento y la inversión tectónica de la mayor parte de la Cuenca de Cañadón Asfalto, representado por fallamiento generalizado y por plegamiento localizado de intensidad y estilo variables. En este momento se desarrollaron pequeñas cuencas intermontanas limitadas por fallas

    Prospects in the orbital and rotational dynamics of the Moon with the advent of sub-centimeter lunar laser ranging

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    Lunar Laser Ranging (LLR) measurements are crucial for advanced exploration of the laws of fundamental gravitational physics and geophysics. Current LLR technology allows us to measure distances to the Moon with a precision approaching 1 millimeter. As NASA pursues the vision of taking humans back to the Moon, new, more precise laser ranging applications will be demanded, including continuous tracking from more sites on Earth, placing new CCR arrays on the Moon, and possibly installing other devices such as transponders, etc. Successful achievement of this goal strongly demands further significant improvement of the theoretical model of the orbital and rotational dynamics of the Earth-Moon system. This model should inevitably be based on the theory of general relativity, fully incorporate the relevant geophysical processes, lunar librations, tides, and should rely upon the most recent standards and recommendations of the IAU for data analysis. This paper discusses methods and problems in developing such a mathematical model. The model will take into account all the classical and relativistic effects in the orbital and rotational motion of the Moon and Earth at the sub-centimeter level. The new model will allow us to navigate a spacecraft precisely to a location on the Moon. It will also greatly improve our understanding of the structure of the lunar interior and the nature of the physical interaction at the core-mantle interface layer. The new theory and upcoming millimeter LLR will give us the means to perform one of the most precise fundamental tests of general relativity in the solar system.Comment: 26 pages, submitted to Proc. of ASTROCON-IV conference (Princeton Univ., NJ, 2007

    Electron Standing Wave Formation in Atomic Wires

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    Using the Landauer formulation of transport theory and tight binding models of the electronic structure, we study electron transport through atomic wires that form 1D constrictions between pairs of metallic nano-contacts. Our results are interpreted in terms of electron standing waves formed in the atomic wires due to interference of electron waves reflected at the ends of the atomic constrictions. We explore the influence of the chemistry of the atomic wire-metal contact interfaces on these standing waves and the associated transport resonances by considering two types of atomic wires: gold wires attached to gold contacts and carbon wires attached to gold contacts. We find that the conductance of the gold wires is roughly 1G0=2e2/h1 G_0 = 2 e^2/h for the wire lengths studied, in agreement with experiments. By contrast, for the carbon wires the conductance is found to oscillate strongly as the number of atoms in the wire varies, the odd numbered chains being more conductive than the even numbered ones, in agreement with previous theoretical work that was based on a different model of the carbon wire and metal contacts.Comment: 14 pages, includes 6 figure
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