This study attempts to obtain the correlation between lightning activities and aerosol optical depth over the Himalayan and lesser Himalayan region. To investigate the association between Aerosol Optical Depth (AOD) w...
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In the course of a severe accident, fission products from the damaged core can be released into the containment in the form of aerosols. These aerosols are radioactive and can be transported anywhere, which increases ...
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Vertical drainage and vent pipelines in a building are crucial components for the inter-flat transportation of sewage and exhaust gas, which serves as the primary route for the transmission of aerosols produced by def...
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ObjectiveThe purpose of the present observational study was to evaluate the bacterial load in the air following various dental procedures. MethodsAir contamination following seven aerosol-generating dental procedures ...
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ObjectiveThe purpose of the present observational study was to evaluate the bacterial load in the air following various dental procedures. MethodsAir contamination following seven aerosol-generating dental procedures was assessed. The air volume was sampled by a wet cyclone collector for 10 min during 10 sessions of the following procedures: air-polishing, ultrasonic instrumentation, manual instrumentation, rubber cup polishing, cavity preparation with a 1:5 red contra-angle, cavity preparation with turbine and Low Volume Evacuator (LVE), and cavity preparation with turbine and High Volume Evacuator (HVE). Contamination of the sampled solution was determined using ATP (Adenosine TriPhosphate) quantification of the viable bacterial count, and compared to baseline measurements. ResultsThe baseline air contamination was 1.45 (0.85-2.04) CFUs/L of air. The highest increase in air contamination was observed after the use of a turbine with LVE, with an average of 7.38 (95% CI 3.87-10.89) CFUs/L of air (p < 0.01). The use of the turbine with HVE and the use of the red hand-piece resulted in non-significant increases in bacterial counts compared to baseline (2.98 [1.34-4.63] and 2.70 [0.18-4.22] CFUs/L of air respectively). The application of air polishing, ultrasonic instrumentation, hand instrumentation and rubber cups did not result in a higher bacterial count than the baseline. ConclusionRoutine professional oral hygiene procedures do not increase air contamination. However, cavity excavation with LVE creates a significantly higher bacterial count in the air.
aerosols' influences on Earth's climate have been documented by several authors. This ranges from scattering and reflecting of shortwave radiation (direct effect) which is also regarded as the "Whitehouse...
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aerosols' influences on Earth's climate have been documented by several authors. This ranges from scattering and reflecting of shortwave radiation (direct effect) which is also regarded as the "Whitehouse Effect," to the ability to act as condensation nuclei (indirect effect) which results in cloud droplet formation. This broad summary of aerosol's effect on earth's climate has in turn affected some other weather variables either positively or negatively depending on people's perspectives. This work was done in a view to ascertaining some of these claims by determining the statistical significance of some certain aerosol's relationships with some selected weather variables. This was done over six (6) stations across the West African region to represent the climatic zones from the rainforest around the coasts to the desert of the Sahel. Data used consist of aerosol types (biomass burning, carbonaceous, dust, and PM2.5) and climatic types (convective precipitation, wind speed, and water vapor) over a period of 30 years, with the python and ferret programs explicitly used for the graphical analyses. Climatologically, locations close to the point source seem to record more of the presence of the pollutants than the farthest ones. Results indicated that aerosols were more pronounced in the dry months of NDJF over the rainforest region depending on the latitudinal position of the location. The relationship result showed a negative correlation between convective precipitation and aerosols, except carbonaceous. But the strongest relationship can be found between water vapor and the selected aerosol types.
This study investigated the variability of radioactive and stable aerosols (Be-7,Pb- 210, Cs-137, K-40, PM10, and PM2.5) in relation to mixing layer height (MLH) based on outdoor radon and meteorological factors in Br...
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This study investigated the variability of radioactive and stable aerosols (Be-7,Pb- 210, Cs-137, K-40, PM10, and PM2.5) in relation to mixing layer height (MLH) based on outdoor radon and meteorological factors in Bratislava, Slovakia from 2017 to 2021. Aerosol concentrations exhibit distinct seasonal patterns, with higher 7Be concentrations in summer and lower in winter, while( 137)Cs, K-40, Pb-210, PM10 and PM2.5 showed almost the opposite trends. Different statistical techniques, including Pearson's correlation analysis, multiple regression analysis (MRA), and canonical correlation analysis (CCA), were employed to elucidate the intricate relationships between aerosol concentrations, MLH, and meteorological parameters. The MRA identified a significant correlation between aerosol variability and specific predictors, while the CCA highlighted the differential influence of MLH and meteorological parameters on aerosol concentrations. The analysis revealed that temperature, MLH, and relative humidity are the primary factors influencing aerosol concentrations, underscoring their pivotal role in environmental dynamics.
A model for the fast pyrolysis of anisotropic biomass particles is presented which considers bubbling dynamics within the liquid intermediate phase (metaplast) and aerosol ejection from this phase. The model employs t...
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A model for the fast pyrolysis of anisotropic biomass particles is presented which considers bubbling dynamics within the liquid intermediate phase (metaplast) and aerosol ejection from this phase. The model employs the population balance equation and the method of moments to estimate the production rate and resultant size distribution of aerosol ejections, incorporating a detailed CRECK reaction mechanism, and considers the effect of anisotropic biomass microstructure on the intraparticle transport of mass and energy. This study investigates the impact of particle size, heating rate (heat transfer coefficient), and lignocellulosic composition on aerosol ejection. The model predicts that, at high heating rates (convective heat transfer coefficient of 359 W/m(2).K), aerosols can contribute over 20% to the heavy fraction yield in bio-oil for small particles (1 mm diameter, 4 mm length). The model can predict aerosol size distribution and surface area, indicating an average size of 20 mu m for bubbles and 5 mu m for aerosols during increased bubble production and aerosol ejection rates. These findings are consistent with prior experimental results and provide essential information for future modeling of extra-particle reactions of the aerosols as they progress through the reactor.
Lightning has profound social implications for public safety and usually causes casualties and significant damage to infrastructure. Due to the advancement of both ground-based and spaceborne detection technology, lig...
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Lightning has profound social implications for public safety and usually causes casualties and significant damage to infrastructure. Due to the advancement of both ground-based and spaceborne detection technology, lightning has been monitored globally in recent decades as an indicator of severe weather and an essential variable of climate change. This article reviews recent progress in the study of lightning variations and their response to temperature and aerosols, based on both spaceborne and ground-based lightning data. The responses of lightning to temperature and aerosol show large spatial and temporal heterogeneity, with relation to the meteorological and environmental conditions. The latest research show that lightning exhibited significant increase in some high altitude or high latitude regions, such as the Tibetan Plateau and Arctic regions, where undergone fast warming during the recent decades and the ecosystems is fragile. Aerosol particles play an important role in modulating lightning variations under certain dynamical and thermodynamic conditions in some regions, even on a global scale. The projected lightning activity will generally increase in the future but may with very few exceptions. Continuous long-term lightning observations with consistent spatial and temporal detection efficiency remain crucial for tracking the response of lightning to climate change in the coming decades.
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