35 research outputs found

    Greenery as a mitigation strategy to urban heat and air pollution: a comparative simulation-based study in a densely built environment.

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    The urban heat island and the urban air pollution concentration are two major climate-change-related phenomena affecting the built environment worldwide. This paper aims to verify the potential effect of different mitigation measures through a simulation study. In detail the present study focuses on the analysis of the environmental impacts of urban vegetation, such as green facades, vertical greenery, and green pavements. After an extensive screening of the literature review, an investigation of the impact of the most common built environment design variables in a defined case study led to the definition of a typical urban canyon was tested. The results show that the presence of trees in a street canyon could reduce the air temperature peaks by 5-10 °C, while the high-level vegetation canopies can lead to a deterioration in air quality with a PM concentration increasing by 1.2-1.5%. Instead, using low-level green infrastructure improves the air quality conditions on the sidewalk, reducing the NOx in the range of 10-20%. The analyzed high-level greenery generated an air temperature reduction effect on a street level ranging from 8 to 12°C. The present work contributes to clarifying the potential mitigation effect of green infrastructure in a densely built environment, where the risk of increasing temperatures and air pollutants is foreseen to be more intense in the coming years

    Determining behavioural-based risk to SLODs of urban public open spaces: Key performance indicators definition and application on established built environment typological scenarios

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    A behavioural-based approach can be used to assess how users’ reactions to surrounding environmental conditions can alter the urban Built Environment (BE) risk to Slow Onset Disasters (SLODs). Public Open Spaces (POSs) in the BE are relevant scenarios, due to micro-climate-related stress, users’ vulnerabilities (e.g., age, health frailty) and exposure time. Simulation methods can support behavioural-based risk-assessment, but results are generally site-specific. Performing analysis on BE Typologies (BETs) can improve robustness, since BETs represent archetypes from real-world scenarios. This work adopts a behavioural-based approach to evaluate time-dependant users’ risks of POSs in different BETs due to SLODs-related stress (i.e., heat, air pollution). UTCI and AQI values are mapped within each BET. Users’ distributions are then calculated depending on thermal acceptability correlations. Key Performance Indicators are developed associating users’ distribution to SLODs effects on health (i.e., sweat rate, water loss; health affection rate probability). The approach is applied to Italian BETs, under one relevant climate, rating their heat and air pollution risks. Results suggest critical conditions for toddlers. In detail, about 2-hour high heat exposure could result in dehydration, while 1-hour exposure to low NO2 concentration could result in +1% mortality probability. This approach could potentially support decision-makers on BE risk-assessment

    Color heterogeneity of building surfaces: lean image processing approach for visible reflectance characterization performance

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    Daylighting availability and uniformity depend on the interior surface reflectance (). Currently, is obtained through suggested reference values (Illuminating Engineering Society 2012; CIBSE 2015; CIBSE/SLL 2011; CIBSE/SLL 2005), laboratory tests (ASTM E 903 (2012) describes a standardized procedure requiring a calibrated instrument and an as-built surface sample), or by on-site measures (based on luminance and illuminance differences). Novel methodologies compute it by integrating image processing and/or photometry, applied on false colour or HDR images. A simple procedure is needed for accurately assess, even in preliminary design phases, the reflectance of heterogeneous surface areas for new and historical buildings. In fact, heterogeneous surfaces (colour, texture, composition, ageing) difficult the accurate estimation of a representative reflectance value (̅) for building simulation, leading to daylighting performance deviation. This work presents a methodology, based on a per-pixel colour reflectivity () evaluation, to easily acquire an approximate value of the surface visible reflectance (̅). This approach gives a more global ̅ of all surface components, aiming to improve the accuracy of the modelled daylighting analysis. Additionally, the procedure is experimented over a sample reference test room

    Pedestrian Single and Multi-Risk Assessment to SLODs in Urban Built Environment: A Mesoscale Approach

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    Pedestrians are increasingly exposed to slow-onset disasters (SLODs), such as air pollution and increasing temperatures in urban built environments (BEs). Pedestrians also face risks that arise from the combination of the BE features, the effects of SLODs on the microclimate, their own characteristics (e.g., health and ability), and the way they move and behave in indoor and outdoor BE areas. Thus, the effectiveness of sustainable risk-mitigation solutions for the health of the exposed pedestrians should be defined by considering the overlapping of such factors in critical operational scenarios in which such emergency conditions can appear. This work provides an innovative method to define a BE-oriented pedestrian risk index through a dynamic meso-scale approach that considers the daily variation of risk conditions. The method is ensured by a quick-to-apply approach, which also takes advantage of open-source repositories and tools to collect and manage input data, without the need for time-consuming in situ surveys. The resulting risk conditions are represented through meso-scale maps, which highlight the risk differences between BEs by focusing on their open spaces as fundamental parts of the urban road network. The method is applied to a significant case study (in Milan, Italy). The results demonstrate the ability of the approach to identify key input scenarios for risk assessment and mapping. The proposed methodology can: (1) provide insights for simulation activities in critical BE conditions, thanks to the identification of critical daily conditions for each of the factors and for single and multiple risks and (2) support the development of design and regeneration strategies in SLOD-prone urban BEs, as well as the identification of priority areas in the urban B

    Parametric Assessment to Evaluate and Compare the Carbon Footprint of Diverse Manufacturing Processes for Building Complex Surfaces

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    At present, building design is faced with a need to properly manage complex geometries and surfaces. This fact is not only driven by the increased demand for visually stunning spaces but also stems from the rise of new design paradigms, such as “user-centred design”, that include bespoke optimization approaches. Nevertheless, the escalating adoption of customized components and one-off solutions raises valid concerns regarding the optimal use of energy and resources in this production paradigm. This study focuses on the Life Cycle Assessment of a novel Cement–Textile Composite (CTC) patented material. It combines a synthetic reinforcing textile with a customized concrete matrix, to generate rigid elements that are able to statically preserve complex spatial arrangements, particularly double-curvature surfaces. Moreover, the CTC offers a low-volume cost-effective alternative for custom-made cladding applications. The study performed a comparative carbon footprint assessment of the CTC production process in contrast to other technologies, such as CNC milling and 3D printing. To facilitate meaningful comparisons among diverse construction alternatives and to derive generalized data capable of characterizing their overall capacity, independent of specific production configurations, the present study implemented a generalized parametric shape of reference defined as a bounding box (BBOX), which encloses the volume of the target shape. Comparing different production technologies of the same shape with the same BBOX results in a significant carbon saving, up to 9/10th of the carbon footprint, when the CTC technology is adopted. The study therefore highlights the potential environmental advantages of CTC in the fields of architectural design and building engineering

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Built environment and human behavior boosting Slow-onset disaster risk

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    Air pollution concentration and heat wave intensity represent the most recurrent evidence of SLow-Onset Disaster risks that rapidly affect the population in cities. Their manifestation and concurrence depend on the context’s environmental conditions and mass behavior of citizens; risk is more likely to surge during summer, a season progressively getting longer and warmer. This represents even higher risk, since heat and radiation can intensify ground-level pollution. However, these evidences are mostly experienced within the Built Environment, as some of its characteristics have proven to intensify their effect. Thus, this work concentrated on ap-plying data driven methods and tools for identifying representative portions of the Built Envi-ronment in Italian cities (extrapolated from the city of Milan), characterized by extensive his-torical, cultural and architectural heritage, in which critical air pollution concentration and heat wave intensity typically arises. In this analysis, urban canyon and piazzale were identi-fied as morphologies displaying high exposure and vulnerability; also, construction and be-havioral customs are considered
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