The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform
Tiziana Di Carlo - One of the best experts on this subject based on the ideXlab platform.
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Energy-saving policies and low-energy residential buildings: An LCA case study to support decision makers in piedmont (Italy)
International Journal of Life Cycle Assessment, 2010Co-Authors: Gian Andrea Blengini, Tiziana Di CarloAbstract:Background, aim and scope A low-energy family house recently built in Northern Italy was selected by Regione Piemonte as an outstanding example of resource efficient building. An economic incentive was awarded to cover the extra costs of the thermal insulation, windows and equipment in order to decrease the yearly winter heat requirement from the legal standard of 109 to 10 kW h/m2, while existing buildings in the study area typically require 200 kW h/m2. As the building was claimed to be sustainable on the basis of its outstanding energy-saving performance, an ex post life cycle assessment (LCA) was set up to understand whether, and to what extent, the positive judgement could be confirmed in a life cycle perspective. Materials and methods After an analysis of the literature on LCA of whole buildings, a detailed life cycle assessment has been conducted by encompassing all the life cycle phases. Emphasis was given on the end-of-life stage, too often disregarded due to lack of data or heavily simplified. Virtually all the materials used in the building Structure, finishes and equipment were considered, paying attention to their expected service duration and the recycling potential. In order to increase transparency and therefore credibility and acceptance of LCA in the building sector, an uncertainty analysis was carried out. Results and discussion The dramatic contribution of material-related impacts Emerged. Structure and finishes materials represented the highest relative contribution, but maintenance operations also played a major role. The contributions of equipment, construction stage and trans- portation were minor. The important role of the recycling potential also Emerged. Unlike standard buildings, where heating-related impacts overshadow the rest of the life cycle, there is no single dominating item or aspect. Rather, several of them play equally important roles. Conclusions The study confirmed that the initial goal of resource and environmental efficiency was reached, but to a much lower extent than previously thought. In comparison to a standard house,while thewinter heat requirement was reduced from109 to 10kWh/m2 (10:1 ratio), the life cycle energy was only reduced by 2.1:1 and the carbon footprint by 2.2:1. Recommendations and perspectives The findings empha- sise the need for incorporating the life cycle approach in energy-saving policies and economic incentives schemes in the building sector, in Italy and elsewhere, as single-step improvements might not be effective in a life cycle perspective and could even disappoint expectations.
Gian Andrea Blengini - One of the best experts on this subject based on the ideXlab platform.
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Energy-saving policies and low-energy residential buildings: An LCA case study to support decision makers in piedmont (Italy)
International Journal of Life Cycle Assessment, 2010Co-Authors: Gian Andrea Blengini, Tiziana Di CarloAbstract:Background, aim and scope A low-energy family house recently built in Northern Italy was selected by Regione Piemonte as an outstanding example of resource efficient building. An economic incentive was awarded to cover the extra costs of the thermal insulation, windows and equipment in order to decrease the yearly winter heat requirement from the legal standard of 109 to 10 kW h/m2, while existing buildings in the study area typically require 200 kW h/m2. As the building was claimed to be sustainable on the basis of its outstanding energy-saving performance, an ex post life cycle assessment (LCA) was set up to understand whether, and to what extent, the positive judgement could be confirmed in a life cycle perspective. Materials and methods After an analysis of the literature on LCA of whole buildings, a detailed life cycle assessment has been conducted by encompassing all the life cycle phases. Emphasis was given on the end-of-life stage, too often disregarded due to lack of data or heavily simplified. Virtually all the materials used in the building Structure, finishes and equipment were considered, paying attention to their expected service duration and the recycling potential. In order to increase transparency and therefore credibility and acceptance of LCA in the building sector, an uncertainty analysis was carried out. Results and discussion The dramatic contribution of material-related impacts Emerged. Structure and finishes materials represented the highest relative contribution, but maintenance operations also played a major role. The contributions of equipment, construction stage and trans- portation were minor. The important role of the recycling potential also Emerged. Unlike standard buildings, where heating-related impacts overshadow the rest of the life cycle, there is no single dominating item or aspect. Rather, several of them play equally important roles. Conclusions The study confirmed that the initial goal of resource and environmental efficiency was reached, but to a much lower extent than previously thought. In comparison to a standard house,while thewinter heat requirement was reduced from109 to 10kWh/m2 (10:1 ratio), the life cycle energy was only reduced by 2.1:1 and the carbon footprint by 2.2:1. Recommendations and perspectives The findings empha- sise the need for incorporating the life cycle approach in energy-saving policies and economic incentives schemes in the building sector, in Italy and elsewhere, as single-step improvements might not be effective in a life cycle perspective and could even disappoint expectations.
E. Tandberg-hanssen - One of the best experts on this subject based on the ideXlab platform.
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Disruption of Helmet Streamers by Current Emergence
The Astrophysical Journal, 1996Co-Authors: S. T. Wu, E. Tandberg-hanssenAbstract:We have investigated the dynamic response of a coronal helmet streamer to the emergence from below of a current with its magnetic field in a direction opposite to the overlying streamer field. Once the emerging current moves into the closed region of the streamer, a current sheet forms between the emerging field and the streamer field, because the preexisting field and the newly emerging field have opposite polarities. Thus magnetic reconnection will occur at the flanks of the Emerged Structure where the current density is maximum. If the emerging current is large enough, the energy contained in the current and the reconnection will promptly disrupt the streamer. If the emerging current is small, the streamer will experience a stage of slow evolution. In this stage, slow magnetic reconnection occurring at the flanks of the Emerged Structure leads to the degeneration of the Emerged current to a neutral point. Above this point, a new magnetic bubble will form. The resulting configuration resembles an inverse-polarity prominence. Depending on the initial input energy of the current, the resulting Structure will either remain in situ, forming a quasi-static Structure, or move upward, forming a coronal transient similar to coronal jets. The numerical method used in this paper can be used to construct helmet streamers containing a detached magnetic Structure in their closed field region. The quasi-static solution may serve as a preevent corona for studying coronal mass ejection initiation.
Andreas A. Ioannides - One of the best experts on this subject based on the ideXlab platform.
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Semantic geodesic maps: A unifying geometrical approach for studying the Structure and dynamics of single trial evoked responses
Clinical Neurophysiology, 2002Co-Authors: Nikolaos A. Laskaris, Andreas A. IoannidesAbstract:Objectives: A general framework for identifying and describing Structure in a given sample of evoked response single-trial signals (STs) is introduced. The approach is based on conceptually simple geometrical ideas and enables the convergence of pattern analysis and non-linear time series analysis. Methods: Classical steps for analyzing the STs by waveform are first employed and the ST-analysis is transferred to a multidimensional space, the feature space, the geometry of which is systematically studied via multidimensional scaling (MDS) techniques giving rise to semantic maps. The Structure in the feature space characterizes the trial-to-trial variability and this is utilized to probe functional connectivity between two brain areas. The underlying dynamic process responsible for the Emerged Structure can be described by a multidimensional trajectory in the feature space. This in turn enables the detection of dynamical interareal coupling as similarity between the corresponding trajectories. Results and conclusions: The utility of semantic maps was demonstrated using magnetoencephalographic data from a simple auditory paradigm. The coupling of ongoing activity and evoked response is vividly demonstrated and contrasted with the apparent deflection from zero baseline that survives averaging. Prototypes are easily identified as the end points of distinct paths in the semantic map representation, and their neighborhood is populated by STs with distinct properties not only in the latencies where the evoked response is expected to be strong, but also and very significantly in the prestimulus period. Finally our results provide evidence for interhemispheric binding in the (4-8 Hz) range and dynamical coupling at faster time scales. © 2002 Elsevier Science Ireland Ltd. All rights reserved.
S. T. Wu - One of the best experts on this subject based on the ideXlab platform.
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Disruption of Helmet Streamers by Current Emergence
The Astrophysical Journal, 1996Co-Authors: S. T. Wu, E. Tandberg-hanssenAbstract:We have investigated the dynamic response of a coronal helmet streamer to the emergence from below of a current with its magnetic field in a direction opposite to the overlying streamer field. Once the emerging current moves into the closed region of the streamer, a current sheet forms between the emerging field and the streamer field, because the preexisting field and the newly emerging field have opposite polarities. Thus magnetic reconnection will occur at the flanks of the Emerged Structure where the current density is maximum. If the emerging current is large enough, the energy contained in the current and the reconnection will promptly disrupt the streamer. If the emerging current is small, the streamer will experience a stage of slow evolution. In this stage, slow magnetic reconnection occurring at the flanks of the Emerged Structure leads to the degeneration of the Emerged current to a neutral point. Above this point, a new magnetic bubble will form. The resulting configuration resembles an inverse-polarity prominence. Depending on the initial input energy of the current, the resulting Structure will either remain in situ, forming a quasi-static Structure, or move upward, forming a coronal transient similar to coronal jets. The numerical method used in this paper can be used to construct helmet streamers containing a detached magnetic Structure in their closed field region. The quasi-static solution may serve as a preevent corona for studying coronal mass ejection initiation.