Determination of local traffic emission and non-local background source contribution to on-road air pollution using fixed-route mobile air sensor network

2021 ◽  
pp. 118055
Author(s):  
Peng Wei ◽  
Peter Brimblecombe ◽  
Fenhuan Yang ◽  
Abhishek Anand ◽  
Yang Xing ◽  
...  
Keyword(s):  
Air Pollution ◽  
Sensor Network ◽  
Traffic Emission ◽  
Source Contribution ◽  
Local Background ◽  
Non Local

Effect of transport measures and curfew against COVID-19 spread on air pollution (TSP) in Ecuador’s three most populous cities

2020 ◽  
Keyword(s):  
Air Pollution ◽  
Sustainable Consumption ◽  
State Level ◽  
Emergency Situation ◽  
Traffic Emission ◽  
Policy Makers ◽  
Total Suspended Particulates ◽  
Level Ii ◽  
Pm2.5 And Pm10 ◽  
Future Consequences

Although current circumstances pose challenges to foretelling the future consequences of coronavirus spread, we consider environmental load-related researches became more and more important nowadays perhaps as never before. Many experts believe that the increasingly dire public health emergency situation, policy makers and word leaders should make it possible that the COVID-19 outbreak contributes to a transition of sustainable consumption. With the purpose of contributing to rethink the importance of sustainability efforts, here we present total suspended particulates (TSP) results which represent traffic emission caused air pollution in the three most populous cities of Ecuador obtained before, during, and after the: (i) the traffic measures entered into force on state level; (ii) curfew entered into force on state level; (iii) and quarantine entered into force (in Guayaquil, and whole Guayas province). We documented significant decrease in TSP emissions (PM2.5 and PM10) compared to normal traffic operation obtained from some four lanes roads in Quito, Guayaquil, and Cuenca. The most remarkable fall in suspended particulate values (96.47% decrease in PM2.5) compared to emission observed before traffic measures occurred in Cuenca.

scholarly journals The conformal anomaly action to fourth order (4T) in $$d=4$$ in momentum space

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Claudio Corianò ◽  
Matteo Maria Maglio ◽  
Dimosthenis Theofilopoulos
Keyword(s):  
Momentum Space ◽  
Form Factors ◽  
Conformal Anomaly ◽  
Conformal Field Theories ◽  
Conformal Field ◽  
Independent Form ◽  
Stress Energy ◽  
Complete Determination ◽  
Non Local

AbstractWe elaborate on the structure of the conformal anomaly effective action up to 4-th order, in an expansion in the gravitational fluctuations (h) of the background metric, in the flat spacetime limit. For this purpose we discuss the renormalization of 4-point functions containing insertions of stress-energy tensors (4T), in conformal field theories in four spacetime dimensions with the goal of identifying the structure of the anomaly action. We focus on a separation of the correlator into its transverse/traceless and longitudinal components, applied to the trace and conservation Ward identities (WI) in momentum space. These are sufficient to identify, from their hierarchical structure, the anomaly contribution, without the need to proceed with a complete determination of all of its independent form factors. Renormalization induces sequential bilinear graviton-scalar mixings on single, double and multiple trace terms, corresponding to $$R\square ^{-1}$$ R □ - 1 interactions of the scalar curvature, with intermediate virtual massless exchanges. These dilaton-like terms couple to the conformal anomaly, as for the chiral anomalous WIs. We show that at 4T level a new traceless component appears after renormalization. We comment on future extensions of this result to more general backgrounds, with possible applications to non local cosmologies.

scholarly journals Ambient Air Quality Measurement with Low-Cost Optical and Electrochemical Sensors: An Evaluation of Continuous Year-Long Operation

Environments ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 114
Author(s):  
Jiří Bílek ◽  
Ondřej Bílek ◽  
Petr Maršolek ◽  
Pavel Buček
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Sensor Network ◽  
Electrochemical Sensors ◽  
Reference Method ◽  
Ambient Air ◽  
Sensor Data ◽  
Dust Particles ◽  
Concentration Changes ◽  
The Impact

Sensor technology is attractive to the public due to its availability and ease of use. However, its usage raises numerous questions. The general trustworthiness of sensor data is widely discussed, especially with regard to accuracy, precision, and long-term signal stability. The VSB-Technical University of Ostrava has operated an air quality sensor network for more than two years, and its large sets of valid results can help in understanding the limitations of sensory measurement. Monitoring is focused on the concentrations of dust particles, NO2, and ozone to verify the impact of newly planted greenery on the reduction in air pollution. The sensor network currently covers an open field on the outskirts of Ostrava, between Liberty Ironworks and the nearby ISKO1650 monitoring station, where some of the worst air pollution levels in the Czech Republic are regularly measured. In the future, trees should be allowed to grow over the sensors, enabling assessment of the green barrier effect on air pollution. As expected, the service life of the sensors varies from 1 to 3 years; therefore, checks are necessary both prior to the measurement and regularly during operation, verifying output stability and overall performance. Results of the PMx sensory measurements correlated well with the reference method. Concentration values measured by NO2 sensors correlated poorly with the reference method, although timeline plots of concentration changes were in accordance. We suggest that a comparison of timelines should be used for air quality evaluations, rather than particular values. The results showed that the sensor measurements are not yet suitable to replace the reference methods, and dense sensor networks proved useful and robust tools for indicative air quality measurements (AQM).

scholarly journals Influence of nitrogen dioxide and acetylene on marbles, ceramics and pigment

2013 ◽  
Vol 10 (2) ◽  
pp. 183-191
Keyword(s):  
Air Pollution ◽  
Nitrogen Dioxide ◽  
Synergistic Effects ◽  
Scientific Basis ◽  
Solid Surfaces ◽  
Reversed Flow ◽  
The Social ◽  
Tio2 Pigment ◽  
Adsorption Quantity

The air pollution has a great impact on the social and economic aspects all over the world. Thus, the interaction of materials with the atmosphere has received increased attention nowadays. In order to estimate the impacts of air pollution on the solid surfaces a suitable scientific basis is developed and the well known Reversed Flow - Inverse Gas Chromatography, RF- IGC, is used. This dynamic experimental technique leads to very interesting experimental results through the determination of some important physicochemical quantities. The solids studied were Pentelic marble, white TiO2 pigment, ceramic and the gases were NO2 and C2H2. The synergistic effects between acetylene and nitrogen dioxide were also investigated. Through the curves obtained for each adsorption quantity determined versus time, one can easily and accurately conclude the result of the pollution impact on every solid mentioned above. The surface topography and the mechanism of deterioration can also be studied. All the above answer in detail to the questions of where, when and how the influence of gas pollutants on materials of cultural heritage takes place.

scholarly journals Community Air Sensor Network (CAIRSENSE) project: Evaluation of low-cost sensor performance in a suburban environment in the southeastern United States

2016 ◽  
Author(s):  
Wan Jiao ◽  
Gayle Hagler ◽  
Ronald Williams ◽  
Robert Sharpe ◽  
Ryan Brown ◽  
...  
Keyword(s):  
Air Pollution ◽  
Carbon Monoxide ◽  
Air Quality ◽  
Sulfur Dioxide ◽  
Sensor Network ◽  
Correlation Coefficient ◽  
Low Cost ◽  
Ambient Air ◽  
Sensor Technology ◽  
Sensor Performance

Abstract. Advances in air pollution sensor technology have enabled the development of small and low cost systems to measure outdoor air pollution. The deployment of a large number of sensors across a small geographic area would have potential benefits to supplement traditional monitoring networks with additional geographic and temporal measurement resolution, if the data quality were sufficient. To understand the capability of emerging air sensor technology, the Community Air Sensor Network (CAIRSENSE) project deployed low cost, continuous and commercially-available air pollution sensors at a regulatory air monitoring site and as a local sensor network over a surrounding ~ 2 km area in Southeastern U.S. Co-location of sensors measuring oxides of nitrogen, ozone, carbon monoxide, sulfur dioxide, and particles revealed highly variable performance, both in terms of comparison to a reference monitor as well as whether multiple identical sensors reproduced the same signal. Multiple ozone, nitrogen dioxide, and carbon monoxide sensors revealed low to very high correlation with a reference monitor, with Pearson sample correlation coefficient (r) ranging from 0.39 to 0.97, −0.25 to 0.76, −0.40 to 0.82, respectively. The only sulfur dioxide sensor tested revealed no correlation (r  0.5), step-wise multiple linear regression was performed to determine if ambient temperature, relative humidity (RH), or age of the sensor in sampling days could be used in a correction algorithm to improve the agreement. Maximum improvement in agreement with a reference, incorporating all factors, was observed for an NO2 sensor (multiple correlation coefficient R2adj-orig = 0.57, R2adj-final = 0.81); however, other sensors showed no apparent improvement in agreement. A four-node sensor network was successfully able to capture ozone (2 nodes) and PM (4 nodes) data for an 8 month period of time and show expected diurnal concentration patterns, as well as potential ozone titration due to near-by traffic emissions. Overall, this study demonstrates a straightforward methodology for establishing low-cost air quality sensor performance in a real-world setting and demonstrates the feasibility of deploying a local sensor network to measure ambient air quality trends.

scholarly journals Air pollution in landfill of wastes other than hazardous or inert / Zanieczyszczenia powietrza na składowiskach odpadów innych niż niebezpieczne i obojętne

2015 ◽  
Vol 41 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Ewa Miaśkiewicz-Pęska ◽  
Mirosław Szyłak-Szydłowski
Keyword(s):  
Air Pollution ◽  
Chemical Analysis ◽  
Microscopic Fungi ◽  
Gas Chromatograph ◽  
Psychrophilic Bacteria ◽  
Air Samples ◽  
Atmospheric Air ◽  
Bacteria And Fungi ◽  
Portable Gas Chromatograph

Abstract Microbiological and chemical analysis of air was carried out on the area of landfill of wastes other than inert or hazardous. The landfill covers 20 ha and 40 000 Mg of wastes is deposited annually. Municipal waste is not segregated at the landfill. The research was conducted in April, May and November 2012. Number of the psychrophilic and mesophilic bacteria and fungi was estimated by a culture-based method. Quantitative determination of sulfur compounds and meteorological and olfactrometric examinations were also carried out. Chemical analysis was conducted with a Photovac Voyager portable gas chromatograph. Air samples were collected at 5 points. The largest group of microbes were psychrophilic bacteria, especially in summer. The highest concentration of hydrogen sulfide and other odorants was found at leachate tank and landfill body. According to the Polish Standard for the assessment of atmospheric air pollution the air in the area of the landfill is classified as not contaminated and sporadically moderately contaminated. In spring and summer the number of microscopic fungi was increased also in control samples.

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