32 research outputs found

    Sources of water-soluble Brown Carbon at a South-Eastern European Site

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    Atmospheric brown carbon (BrC) is a highly uncertain, but potentially important contributor to light absorption in the atmosphere. Laboratory and field studies have shown that BrC can be produced from multiple sources, including primary emissions from fossil fuel combustion and biomass burning (BB), as well as secondary formation through a number of reaction pathways. It is currently thought that the dominant source of atmospheric BrC is primary emissions from BB, but relatively few studies demonstrate this in environments with complex source profiles. A field campaign was conducted during a month-long wintertime period in 2020 on the campus of the University of Peloponnese in the southwest of Patras, Greece which represents an urban site. During this time, ambient filter samples (a total of 35 filters) were collected from which the water-soluble BrC was determined using a semi-automated system similar to Hecobian et al. (2010), where absorption was measured over a 1 m path length. To measure the BrC, a UV-Vis Spectrophotometer was coupled to a Liquid Waveguide Capillary Cell and the light absorption intensity was recorded at 365 and 700 nm. The latter was used as a reference wavelength. We found that the average BrC absorption in Patras at a wavelength of 365 nm was 8.5 ± 3.9 Mm-1 suggesting that there was significant BrC in the organic aerosol during this period. Attribution of sources of BrC was done using simultaneous chemical composition data observations (primarily organic carbon, black carbon, and nitrate) combined with Positive Matrix Factorization analysis. This analysis showed that in addition to the important role of biomass burning (a contribution of about 20%) and other combustion emissions (also close to 20%), oxidized organic aerosol (approximately 40%) is also a significant contributor to BrC in the study area. Reference Hecobian, A., Zhang, X., Zheng, M., Frank, N., Edgerton, E.S., Weber, R.J., 2010. Water-soluble organic aerosol material and the light-absorption characteristics of aqueous extracts measured over the Southeastern United States. Atmos. Chem. Phys. 10, 5965–5977. https://doi.org/10.5194/acp-10-5965-201

    Oxidative Potential of Atmospheric Particles at an Eastern Mediterranean Site

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    Aerosol oxidative potential (OP; the inherent ability of ambient particles to generate reactive oxygen species in vivo) may be linked to the health effects of population exposure to aerosol and is a metric of their toxicity. The goal of this work was to quantify the water-soluble OP of particles in an urban area in Patras, Greece and to investigate its links with source emissions or components of this particulate matter (PM). A field campaign was conducted during a monthlong wintertime period in 2020 (January 10 to February 13) on the campus of the University of Peloponnese in the southwest of Patras. During this time, ambient filter samples (a total of 35 filters) were collected. To measure the water-soluble OP we used a semiautomated system similar to Fang et al. (2015) based on the dithiothreitol (DTT) assay. The accuracy of our system was validated by measuring the DTT activity of 11 phenanthrequinone (PQN) solutions on both our system and the identical semi-automated validated system at the National Observatory of Athens (NOA). These two sets of analysed DTT activities (current vs. NOA system) were significantly correlated (R2=0.99) with a slope of 1.15 ± 0.04 and an intercept close to zero. We found that the average water-soluble OP in Patras was 1.5 ± 0.3 nmol min-1 m-3, ranging from 0.7 to 2 nmol min-1 m-3. The OP measured in Patras during the campaign is higher than reported values from similar wintertime studies in other urban areas such as Athens (Paraskevopoulou et al., 2019). The average watersoluble OP during a summer study for Patras was significantly lower and equal to 0.18 ± 0.02 nmol min-1 m- 3. Taking into account the average PM1 mass concentrations for these two periods (summer: 6 Όg m-3 and winter: 23 Όg m-3) it is clear that the increase in OP was two times the increase in PM mass making the wintertime aerosol more toxic. Additionally, the water-soluble brown carbon (BrC) was determined using an offline semi-automated system, where absorption was measured over a 1 m path length. The average BrC absorption in Patras at a wavelength of 365 nm was 8.6 ± 3.9 Mm-1 suggesting that there was significant BrC in the organic aerosol during this period. The coefficients of determination, R2, in Table 1 are used as a metric of the potential relationships between the various carbonaceous aerosol components and the DTT activity. The results suggest that the OP is not dominated by a single source or component, but that there are multiple components contributing to it during the study period. Interestingly, the highest correlation coefficient (R2 = 0.46) was found between the OP and Brown Carbon. This is consistent with recently published results for an urban site in Atlanta where the oxidative potential measured with the DTT method also had stronger correlations with BrC during the winter (Gao et al., 2020)

    Analyzing the Impact of Urban Planning and Building Typologies in Urban Heat Island Mitigation

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    Urban and building typologies have a serious impact on the urban climate and determine at large the magnitude of the urban overheating and urban heat island intensity. The present study aims to analyze the impact of various city typologies and urban planning characteristics on the mitigation of the urban heat island. The effect of the building height, street width, aspect ratio, built area ratio, orientation, and dimensions of open spaces on the distribution of the ambient and surface temperature in open spaces is analyzed using the Sydney Metropolitan Area as a case study for both unmitigated and mitigated scenarios. Fourteen precincts are developed and simulated using ENVI-met the simulation tool. The ambient temperature, surface temperature, and wind speed are extracted. The parameter ‘Gradient of the Temperature Decrease along the Precinct Axis’ (GTD) is introduced to study the cooling potential of the various precincts. In the mitigated precincts, the GTD ranges between 0.01 K/m to 0.004 K/m. In the non-mitigated precincts, the GTD ranges between 0.0093 K/m to 0.0024 K/m. A strong correlation is observed between the GTD of all the precincts, with and without mitigation, and their corresponding average aspect ratio, (Height of buildings to Width of streets). The higher the aspect ratio of the precinct, the lower the cooling potential. It is also observed that the higher the Built Area Ratio of the precincts, the lower the cooling contribution of the mitigation measures

    Significant spatial gradients in new particle formation frequency in Greece during summer

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    Extensive continuous particle number size distribution measurements took place during two summers (2020 and 2021) at 11 sites in Greece for the investigation of the frequency and the spatial extent of new particle formation (NPF). The study area is characterized by high solar intensity and fast photochemistry and has moderate to low fine particulate matter levels during the summer. The average PM2.5 levels were relatively uniform across the examined sites. The NPF frequency during summer varied from close to zero in the southwestern parts of Greece to more than 60 % in the northern, central, and eastern regions. The mean particle growth rate for each station varied between 3.4 and 8 nm h−1, with an average rate of 5.7 nm h−1. At most of the sites there was no statistical difference in the condensation sink between NPF event and non-event days, while lower relative humidity was observed during the events. The high-NPF-frequency sites in the north and northeast were in close proximity to both coal-fired power plants (high emissions of SO2) and agricultural areas with some of the highest ammonia emissions in the country. The southern and western parts of Greece, where NPF was infrequent, were characterized by low ammonia emissions, while moderate levels of sulfuric acid were estimated (107 molec. cm−3) in the west. Although the emissions of biogenic volatile organic compounds were higher in western and southern sectors, they did not appear to lead to enhanced frequency of NPF. The infrequent events at these sites occurred when the air masses had spent a few hours over areas with agricultural activities and thus elevated ammonia emissions. Air masses arriving at the sites directly from the sea were not connected with atmospheric NPF. These results support the hypothesis that ammonia and/or amines limit new particle formation in the study area.</p

    HIGH PREVALENCE OF Strongyloides stercoralis INFECTION AMONG THE ELDERLY IN BRAZIL

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    SUMMARY Little is known about the frequency of intestinal parasites in the elderly due to a lack of attention given to the occurrence of these infections among older adults. This study compares the frequency of Strongyloides stercoralis and other enteroparasites between elderly living in nursing homes (n = 100) and those noninstitutionalized (n = 100) from UberlĂąndia, state of Minas Gerais, southeastern Brazil, associated with data of epidemiological and socio-demographic conditions. Through coproparasitological examination of both groups, enteroparasites were detected in 15 of 200 individuals examined (7.5%; CI: 5.1- 9.9). S. stercoralis was the most frequent parasite 10/200 (5%; CI: 4.2-5.8), being significantly higher in males and in individuals with autonomy for daily living activities. There were no statistical differences in the prevalence of parasites between the two groups compared. In conclusion, S. stercoralis infection was highly prevalent in elderly patients and it does not depend on whether the individual was institutionalized or not

    From the Sum of Near-Zero Energy Buildings to the Whole of a Near-Zero Energy Housing Settlement: The Role of Communal Spaces in Performance-Driven Design

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    Almost a century ago Modernism challenged the structure of the city and reshaped its physical space in order to, amongst other things, accommodate new transportation infrastructure and road networks proclaiming the,nowadays much-debated ‘scientificated’ pursuit of efficiency for the city. This transformation has had a great impact on the way humans still design, move in, occupy and experience the city. Today major cities in Europe, such as Paris and London, are considering banning vehicles from their historic centers. In parallel, significant effort is currently underway internationally by designers, architects, and engineers to integrate innovative technologies and sophisticated solutions for energy production, management, and storage, as well as for efficient energy consumption, into the architecture of buildings. In general, this effort seeks for new technologies and design methods (e.g., DesignBuilder with EnergyPlus simulation engine; Rhicoceros3D with Grasshopper plugin and Ecotect, Radiance and EnergyPlus tools) that would enable a holistic approach to the spatial design of Near-Zero Energy buildings, so that their ecological benefits are an added value to the architectural design and a building’s visual, and material, impact on its surrounding space. The paper inquires how the integration of such technological infrastructure and performance-orientated interfaces changes yet again the structure and form of cities, and to what extent it safeguards social rights and enables equal access to common resources. Drawing from preliminary results and initial considerations of ongoing research that involve the construction of four innovative NZE settlements across Europe, in the context of the EU-funded ZERO-PLUS project, this paper discusses the integration of novel infrastructure in communal spaces of these settlements. In doing so, it contributes to the debate about smart communities and their role in the sustainable management of housing developments and settlements that are designed and developed with the concept of smart territories

    Consumer Factsheet: Bidet douche seats, flexible hoses and bidets

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    The purpose of this factsheet is to inform consumers about the function of bidet douche seats, flexible hoses and bidets and about the hazards associated to non-compliant installations of these fittings in their bathrooms

    Industry bulletin: COVID-19

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    Evidence Based Practice Review: Lighting your Way into Home Modifications, 2nd ed.

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    Background: The aging process causes changes in the human visual system that lead to significant decreases in mobility performance. Older people and people with vision impairments often struggle to walk around and orientate, not only in new but also in familiar environments, such as residential hallways. Lighting is one of the environmental parameters that can either improve or impair the mobility of people in residential hallways.Objectives: To identify the characteristics of the lighting system that would enable independent and safe mobility of older people and people with vision impairments in a residential hallway.Search Methods: Systematic search through the HMinfo Library, Google Scholar and Standard Electronic Databases to retrieve 117 scientific publications, 1 legislative document, 4 Australian Standards, 2 International Standards and 3 industry guides.Data Collection and analysis: 117 publications were identified, and 27 studies were analysed and included in the review.Results: The mobility performance of people with vision impairments in hallways is better in photopic, than in mesopic or scotopic conditions. Generally, within the photopic range, the higher the illuminance levels, the better the performance of the participants. Ambient lighting systems and systems that provide perceptual cues of the environment are preferred by people and lead to better performances.Authors Conclusions: The lighting of residential hallways should be adapted to the time of day and the needs of the users, to provide safe and independent movement, without disrupting the daily rhythms of people. Hybrid lighting systems, comprising of low ambient lighting and wayfinding elements seem to be effective for mobility in mesopic and scotopic conditions

    Consumer Factsheet: Designing home environments for people who experience problems with cognition and who display aggressive or self- injurious behaviour. Ed. 2

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    This Consumer Factsheet gives information about elements and systems that can be used to make a home safer and more comfortable for people with cognitive impairments, presenting self-injurious or aggressive behaviour and their family members or carers
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