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Urban air pollution is still an emerging environmental problem, it causes damage to health and is difficult to be controlled in urban centers. The population of large metropolises is often exposed to concentrations of nitrogen oxides (NOx), mainly due to vehicle emissions. Epidemiological studies claim that exposure to these oxides is strongly corr...
Contexts in source publication
Context 1
... measurements were performed in five Brazilian urban centers (São Paulo, Belo Horizonte, Rio de Janeiro, Londrina and Salvador), as shown in Table 1 and Figure 1. The sampling points represent an external environment with intense vehicular flow. ...Context 2
... Londrina has more defined seasons and intense rainfall throughout the year. Table 1 includes information on the vehicle fleet in the five urban centers, besides to the percentage of the vehicle fleet, that were manufactured before 1997, when it became mandatory in Brazil the use of catalysts in vehicles. ...Context 3
... data of Table 1 shows that São Paulo has the largest oldest vehicular fleet (28% without catalysts), although this data is very close to that one found for Rio de Janeiro and Londrina. Belo Horizonte and Salvador, very different centers about diesel consumption, have practically the same percentage of vehicles without use of catalysts. ...Context 4
... is a closed PS kit, with covering that serves as protection during outdoors exposure (Figure 1), also making it safe for transporting the kit over long distances. Thus, the kits could be sent by air mail to the different sampling sites, in distant urban centers (Table 1), where they were received, exposed for 7 days and returned to our laboratory for all chemical analyzes. ...Context 5
... concentration of nitrogen oxides in the atmosphere was presented in the following order: São Paulo > Belo Horizonte > Rio de Janeiro > Londrina > Salvador. These results can indicate a direct correlation with the consumption of diesel fuel, the predominant source of emission of these gases in urban atmospheres, mainly when it is associated with the vehicle fleet and its age (Table 1). This table shows the consumption of this fuel in the cities in study, already considering the final consumer, according to the National Petroleum Agency-Brazil. 26 The order of diesel consumption between 2017/2018 was exactly the one observed for the levels of nitrogen oxides in the air (São Paulo > Belo Horizonte > Rio de Janeiro > Londrina > Salvador). ...Context 6
... 7b shows that, in general, Brazilian urban centers present high NO 2 /NOx ratios, representing intense primary NO 2 emissions and favoring the chemistry of the atmosphere in the formation of secondary NO 2 . ANP data 26 show an increase in the number of vehicles powered by diesel, and consequently, an increase in diesel consumption in recent years ( Table 1), inferring that the results presented may be more associated with the increase in the contribution of direct emissions of NO 2 for the total NOx levels. ...Similar publications
Atmospheric pressure non-equilibrium plasmas can form nitrogen oxide (NO x ) compounds directly from nitrogen and oxygen without a catalyst, and at lower catalyst temperatures than would be possible without plasma. In this work, the oxidation of plasma-produced NO from an Ar/N2/O2 non-equilibrium atmospheric-pressure plasma-jet (APPJ) over a platin...
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Nitrogen oxides (NOx) gases, such as nitrous oxide (N2O), nitrogen oxide (NO), and nitrogen dioxide (NO2), are considered the most hazardous exhausts exhaled by industries and stationary and non-stationary application engines. Investigation of catalytic decomposition of NO has been carried out on copper ion exc...
Benefits from EV (Electric vehicles) and e-mobility include the reduction of local emissions of pollutants from particulate matter (PM0.5, PM5, and PM10) and nitrogen oxides (NOx and NO2). Cities and urban agglomerations benefit the most from potential emission reductions from EVs due to the large number of cars utilized in most urban traffic syste...
Although many considerable efforts have been done to reveal the driving factors on haze aggravation, however, the roles of aerosol liquid water (ALW) in secondary inorganic aerosol (SIA) formation were mainly focused on the condition of aerosol liquid water content (ALWC) < 100 µg m−3. Based on the in situ high-resolution field observations, this w...
We compared the activity enhancement effect of noble metal deposited on TiO2 in photocatalytic nitrogen oxides oxidation. Titanium dioxide was decorated with Ag, Au, Pt or Pd in the sol-gel process. Synthesized catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller measurement (BET), X-ray photoelectron spectroscopy (XPS),...
Citations
... With exceptions, NO accounts for the remainder of the percentage and is the dominant factor of NOx in tailpipe emissions (Xiang et al. 2022). A higher NO 2 /NOx ratio indicates a more rapid transformation of NO to NO 2 by reacting with O 3 (Da Rocha et al. 2022). In contrast, semi-rural sites had lower ratios implying less influence of traffic emissions. ...
... For example, (Sather et al. 2007) found the difference of mostly less than 1 ppb for NO 2 duplicate samples. Da Rocha et al. (2022). found the precision of 3.1% and 2.7% for NOx and NO 2 , respectively. ...
