THE MUST MODEL EVALUATION EXERCISE: STATISTICAL ANALYSIS OF MODELLING RESULTS

The first validation exercise of the COST action 732 lead to a substantial number of simulation results for comparison with the MUST wind tunnel experiments. Validation metrics for selected simulation results of the flow field and the concentrations are presented and compared to the state of the art. In addition mean metrics and corresponding scatter limits are computed from the individual results

THE MUST MODEL EVALUATION EXERCISE: PATTERNS IN MODEL PERFORMANCE

As part of the COST 732 action more than a dozen different research groups have modelled the MUST experiment, as simulated in a wind tunnel. The model evaluation guidance developed within COST 732 recommends \u27exploratory data analysis\u27 as one of the elements in model validation. Experience has shown that such exploratory analysis is crucial to reveal shortcomings of models that might otherwise pass unnoticed. Conditions are best for detecting common patterns and anomalies if you have a situation where several models are put into a common framework – like the case at hand. The available material provides a unique opportunity to identify and explore patterns within model performance

Impact of photocatalytic remediation of pollutants on urban air quality

SSCI-VIDE+CARE+CGOInternational audienceIn the recent years, photocatalytic self-cleaning and "depolluting" materials have been suggested as a remediation technology mainly for NOx and aromatic VOCs in urban areas. A number of products incorporating the aforementioned technology have been made commercially available with the aim to improve urban air quality. These commercial products are based on the photocatalytic properties of a thin layer of TiO2 at the surface of the material (such as glass, pavement, etc.) or embedded in paints or concrete. The use of TiO2 photocatalysts as an emerging air pollution control technology has been reported in many locations worldwide. However, up to now, the effectiveness measured in situ and the expected positive impact on air quality of this relatively new technology has only been demonstrated in a limited manner. Assessing and demonstrating the effectiveness of these depolluting techniques in real scale applications aims to create a real added value, in terms of policy making (i.e., implementing air quality strategies) and economics (by providing a demonstration of the actual performance of a new technique). (C) Higher Education Press and Springer-Verlag Berlin Heidelberg 201

Cost Action Es1006. Evaluation, improvement and guidance of local-scale emergency prediction and response tools for airborne hazards in built environments: Ongoing activities, experiments and recent results

International audienceThe COST Action ES1006 is mainly aimed at evaluating and improving the reliability of neighbourhoodscale emergency response tools on the basis of a comprehensive, concerted and harmonized crossnational approach. The main focus is the evaluation of the air dispersion models, when used in urban or industrial environments with complex building structures, and their integration in emergency response systems. In the frame of this research, three working groups are carrying out several activities such as: to inventory models, tools and methodologies currently applied in the context of emergency management and local-scale threat reduction; to categorize and characterize local-scale threat scenarios; to identify the main gaps, deficiencies and limitations in presently available knowledge and models and to determine the directions for the development of the next generation of models; to test and evaluate available models by model inter-comparison and by comparison against test data from qualified field and laboratory experiments. The ongoing activities in the three WGs and the latest available results will be presented. © Copyright 2014, AIDIC Servizi S.r.l

Photocatalytic abatement results from a model street canyon

SSCI-VIDE+CARE+RCI:FBE:ABO:NCA:YDU:CGOInternational audienceDuring the European Life+ project PhotoPAQ (Demonstration of Photocatalytic remediation Processes on Air Quality), photocatalytic remediation of nitrogen oxides (NOx), ozone (O3), volatile organic compounds (VOCs), and airborne particles on photocatalytic cementitious coating materials was studied in an artificial street canyon setup by comparing with a colocated nonactive reference canyon of the same dimension (5 × 5 × 53 m). Although the photocatalytic material showed reasonably high activity in laboratory studies, no significant reduction of NOx, O3, and VOCs and no impact on particle mass, size distribution, and chemical composition were observed in the field campaign. When comparing nighttime and daytime correlation plots of the two canyons, an average upper limit NOx remediation of ≤2 % was derived. This result is consistent only with three recent field studies on photocatalytic NOx remediation in the urban atmosphere, whereas much higher reductions were obtained in most other field investigations. Reasons for the controversial results are discussed, and a more consistent picture of the quantitative remediation is obtained after extrapolation of the results from the various field campaigns to realistic main urban street canyon conditions