84 research outputs found

    Existing benchmark systems for assessing global warming potential of buildings – Analysis of IEA EBC Annex 72 cases

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    Life cycle assessment (LCA) is increasingly being used as a tool by the building industry and actors to assess the global warming potential (GWP) of building activities. In several countries, life cycle based requirements on GWP are currently being incorporated into building regulations. After the establishment of general calculation rules for building LCA, a crucial next step is to evaluate the performance of the specific building design. For this, reference values or benchmarks are needed, but there are several approaches to defining these. This study presents an overview of existing benchmark systems documented in seventeen cases from the IEA EBC Annex 72 project on LCA of buildings. The study characterizes their different types of methodological background and displays the reported values. Full life cycle target values for residential and non-residential buildings are found around 10-20 kg CO2_2e/m2^2/y, whereas reference values are found between 20-80 kg CO2_2e/m2^2/y. Possible embodied target- and reference values are found between 1-12 kg CO2_2e/m2^2/y for both residential and non-residential buildings. Benchmark stakeholders can use the insights from this study to understand the justifications of the background methodological choices and to gain an overview of the level of GWP performance across benchmark systems

    Existing benchmark systems for assessing global warming potential of buildings – Analysis of IEA EBC Annex 72 cases

    Get PDF
    Life cycle assessment (LCA) is increasingly being used as a tool by the building industry and actors to assess the global warming potential (GWP) of building activities. In several countries, life cycle based requirements on GWP are currently being incorporated into building regulations. After the establishment of general calculation rules for building LCA, a crucial next step is to evaluate the performance of the specific building design. For this, reference values or benchmarks are needed, but there are several approaches to defining these. This study presents an overview of existing benchmark systems documented in seventeen cases from the IEA EBC Annex 72 project on LCA of buildings. The study characterizes their different types of methodological background and displays the reported values. Full life cycle target values for residential and non-residential buildings are found around 10-20 kg CO2e/m2/y, whereas reference values are found between 20-80 kg CO2e/m2/y. Possible embodied target- and reference values are found between 1-12 kg CO2e/m2/y for both residential and non-residential buildings. Benchmark stakeholders can use the insights from this study to understand the justifications of the background methodological choices and to gain an overview of the level of GWP performance across benchmark systems.publishedVersio

    Comparison of the greenhouse gas emissions of a high-rise residential building assessed with different national LCA approaches – IEA EBC Annex 72

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    Introduction: The international research project IEA EBC Annex 72 investigates the life cycle related environmental impacts caused by buildings. The project aims inter alia to harmonise LCA approaches on buildings. Methods: To identify major commonalities and discrepancies among national LCA approaches, reference buildings were defined to present and compare the national approaches. A residential high-rise building located in Tianjin, China, was selected as one of the reference buildings. The main construction elements are reinforced concrete shear walls, beams and floor slabs. The building has an energy reference area of 4566 m2 and an operational heating energy demand of 250 MJ/m2a. An expert team provided information on the quantities of building materials and elements required for the construction, established a BIM model and quantified the operational energy demand. Results: The greenhouse gas emissions and environmental impacts of the building were quantified using 17 country-specific national assessment methods and LCA databases. Comparisons of the results are shown on the level of building elements as well as the complete life cycle of the building. Conclusions: The results of these assessments show that the main differences lie in the LCA background data used, the scope of the assessment and the reference study period applied. Despite the variability in the greenhouse gas emissions determined with the 17 national methods, the individual results are relevant in the respective national context of the method, data, tool and benchmark used. It is important that environmental benchmarks correspond to the particular LCA approach and database of a country in which the benchmark is applied. Furthermore, the results imply to include building technologies as their contribution to the overall environmental impacts is not negligible. Grant support: The authors thank the IEA for its organizational support and the funding organizations in the participating countries for their financial support.IEA -International Energy Agency(undefined

    Crustins: enigmatic WAP domain-containing antibacterial proteins from crustaceans

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    Crustins are antibacterial proteins of ca. 7Ăąïżœïżœ14 kDa with a characteristic four-disulphide core-containing whey acidic protein (WAP) domain, expressed by the circulating haemocytes of crustaceans. Over 50 crustin sequences have been now reported from a variety of decapods, including crabs, lobsters, shrimp and crayfish. Three main types seem to occur but all possess a signal sequence at the amino terminus and a WAP domain at the carboxyl end. Differences between types lie in the structure of the central region. Those crustins purified as the native protein or expressed recombinantly all kill Gram-positive bacteria, and gene studies have shown that they are constitutively expressed, often at high levels, but show no consistent patterns of change in expression following injection ofbacteria. This variable response to infection is enigmatic but indicates that these proteins could perform additional functions, perhaps as immune regulators in recovery from wounding, trauma or physiological stress

    Comparison of the environmental assessment of an identical office building with national methods

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    The IEA EBC Annex 72 focuses on the assessment of the primary energy demand, greenhouse gas emissions and environmental impacts of buildings during production, construction, use (including repair and replacement) and end of life (dismantling), i.e. during the entire life cycle of buildings. In one of its activities, reference buildings (size, materialisation, operational energy demand, etc.) were defined on which the existing national assessment methods are applied using national (if available) databases and (national/regional) approaches. The ?be2226? office building in Lustenau, Austria was selected as one of the reference buildings. TU Graz established a BIM model and quantified the amount of building elements as well as construction materials required and the operational energy demand. The building assessment was carried out using the same material and energy demand but applying the LCA approach used in the different countries represented by the participating Annex experts. The results of these assessments are compared in view of identifying major discrepancies. Preliminary findings show that the greenhouse gas emissions per kg of building material differ up to a factor of two and more. Major differences in the building assessments are observed in the transports to the construction site (imports) and the construction activities as well as in the greenhouse gas emissions of the operational energy demand (electricity). The experts document their practical difficulties and how they overcame them. The results of this activity are used to better target harmonisation efforts.IEA -International Association for the Evaluation of Educational Achievement(Slovenia

    Performances du Reseau Experimental ATM SPSMA

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    Dans le cadre des etudes "temps reel" en vue des controles de LHC, la technologie ATM a ete experimentee. Cette note decrit les performances specifiques mesurees sur le reseau experimental SPSMA

    The interplay of top-down focal attention and the cortical tracking of speech.

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    Many active neuroimaging paradigms rely on the assumption that the participant sustains attention to a task. However, in practice, there will be momentary distractions, potentially influencing the results. We investigated the effect of focal attention, objectively quantified using a measure of brain signal entropy, on cortical tracking of the speech envelope. The latter is a measure of neural processing of naturalistic speech. We let participants listen to 44 minutes of natural speech, while their electroencephalogram was recorded, and quantified both entropy and cortical envelope tracking. Focal attention affected the later brain responses to speech, between 100 and 300 ms latency. By only taking into account periods with higher attention, the measured cortical speech tracking improved by 47%. This illustrates the impact of the participant's active engagement in the modeling of the brain-speech response and the importance of accounting for it. Our results suggest a cortico-cortical loop that initiates during the early-stages of the auditory processing, then propagates through the parieto-occipital and frontal areas, and finally impacts the later-latency auditory processes in a top-down fashion. The proposed framework could be transposed to other active electrophysiological paradigms (visual, somatosensory, etc) and help to control the impact of participants' engagement on the results.status: Published onlin

    Data-driven spatial filtering for improved measurement of cortical tracking of multiple representations of speech

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    OBJECTIVE: Measurement of the cortical tracking of continuous speech from electroencephalography (EEG) recordings using a forward model is an important tool in auditory neuroscience. Usually the stimulus is represented by its temporal envelope. Recently, the phonetic representation of speech was successfully introduced in English. We aim to show that the EEG prediction from phoneme-related speech features is possible in Dutch. The method requires a manual channel selection based on visual inspection or prior knowledge to obtain a summary measure of cortical tracking. We evaluate a method to (1) remove non-stimulus-related activity from the EEG signals to be predicted, and (2) automatically select the channels of interest. APPROACH: Eighteen participants listened to a Flemish story, while their EEG was recorded. Subject-specific and grand-average temporal response functions were determined between the EEG activity in different frequency bands and several stimulus features: the envelope, spectrogram, phonemes, phonetic features or a combination. The temporal response functions were used to predict EEG from the stimulus, and the predicted was compared with the recorded EEG, yielding a measure of cortical tracking of stimulus features. A spatial filter was calculated based on the generalized eigenvalue decomposition (GEVD), and the effect on EEG prediction accuracy was determined. MAIN RESULTS: A model including both low- and high-level speech representations was able to better predict the brain responses to the speech than a model only including low-level features. The inclusion of a GEVD-based spatial filter in the model increased the prediction accuracy of cortical responses to each speech feature at both single-subject (270% improvement) and group-level (310%). SIGNIFICANCE: We showed that the inclusion of acoustical and phonetic speech information and the addition of a data-driven spatial filter allow improved modelling of the relationship between the speech and its brain responses and offer an automatic channel selection.status: publishe
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