Prashant Kumar

Bio: Prashant Kumar is an academic researcher from University of Surrey. The author has contributed to research in topics: Air quality index & Medicine. The author has an hindex of 54, co-authored 363 publications receiving 11561 citations. Previous affiliations of Prashant Kumar include Southeast University & Dr. B. R. Ambedkar National Institute of Technology Jalandhar.

Nanoparticle emissions from traditional pottery manufacturing

Abstract: Traditional pottery manufacturing involves firing of the ceramics in kilns, a process that leads to high concentrations of airborne particles that are harmful to human health. In order to assess the associated exposure levels and the involved risks, here, for the first time, we investigate the size, the concentration and the elemental composition of the particles emitted during the different stages of the ceramic firing process. Number size distributions of the emitted particles, having diameters in the range from 10 nm to 20 μm, were measured in a traditional small-sized pottery studio using a Scanning Mobility Particle Sizer (SMPS) and an Optical Particle Counter (OPC). The measurements showed dominance of the nanoparticle mode (i.e., particles smaller than 100 nm) when the kiln reached temperatures above 600 °C. The mean size of the particles ranged from 30 to 70 nm and their peak number concentration was 6.5 × 105 cm−3 during the first stage of the firing process where the ceramics were unpainted and unglazed. During the second stage of the firing process, where the ceramics were painted and glazed, the mean particle size ranged from 15 to 40 nm and their number concentration peaked at 1.2 × 106 cm−3. Elemental analysis of individual particles collected during the two firing stages and studied by Energy-Dispersive X-ray (EDX) spectroscopy showed that the emitted nanoparticles contain significant amounts of lead. These findings provide new information for understanding the health impacts of traditional pottery manufacturing, and underline the need for adopting adequate measures to control nanoparticle emissions at the source.

Modeling of Atmospheric Aerosol Properties in the São Paulo Metropolitan Area: Impact of Biomass Burning

Abstract: Smoke particles ejected into the atmosphere from biomass burning can modify the atmospheric composition around and even 30 far from the sources. In late winter and early spring, biomass burning emissions from inland regions can be efficiently 31 transported to urban areas in south-eastern South America, thus affecting air quality in those areas. In this study, the Weather 32 Research and Forecasting with Chemistry (WRF-Chem) model was applied in order to investigate the impact of biomass 33 burning sources on aerosol loadings and properties over the Sao Paulo Metropolitan Area (SPMA), in south-eastern Brazil, 34 during the period from 19 August to 3 September 2014. The model performance was evaluated using available aerosol 35 measurements from the Narrowing the Uncertainties on Aerosol and Climate Change in Sao Paulo State (NUANCE-SPS) 36 project. The combined application of aerosol data and WRF-Chem simulations made it possible to represent some of the most 37 important aerosol properties, such as particle number concentration (PNC) and cloud condensation nuclei (CCN) activation, in 38 addition to evaluation of the impact of biomass burning by analysing a five-day transport event, from 22 August to 26 August 39 2014. During this transport event, differences in the average predicted PM2.5 concentration reached 15 μg m−3 (peaking at 20 40 μg m−3 during the night-time hours) over the SPMA, compared with 35 μg m−3 over inland areas northwest and north of the 41 SPMA. Biomass burning accounted for up to 20 % of the baseline PNC- and CCN-weighted relative differences over the 42 SPMA (2300 cm−3 and 1400 cm−3, respectively).

The role of materials selection in the urban heat island effect in dry mid-latitude climates

Abstract: This work investigates the role of materials selected for different urban surfaces (e.g. on building walls, roofs and pavements) in the intensity of the urban heat island (UHI) phenomenon. Three archetypal street-canyon geometries are considered, reflecting two-dimensional canyon arrays with frontal packing densities (λf) of 0.5, 0.25 and 0.125 under direct solar radiation and ground heating. The impact of radiative heat transfer in the urban environment is examined for each of the different built packing densities. A number of extreme heat scenarios were modelled in order to mimic conditions often found at low- to mid-latitudes dry climates. The investigation involved a suite of different computational fluid dynamics (CFD) simulations using the Reynolds-Averaged Navier–Stokes equations for mass and momentum coupled with the energy equation as well as using the standard k-e turbulence model. Results indicate that a higher rate of ventilation within the street canyon is observed in areas with sparser built packing density. However, such higher ventilation rates were not necessarily found to be linked with lower temperatures within the canyon; this is because such sparser geometries are associated with higher heat transfer from the wider surfaces of road material under the condition of direct solar radiation and ground heating. Sparser canyon arrays corresponding to wider asphalt street roads in particular, have been found to yield substantially higher air temperatures. Additional simulations indicated that replacing asphalt road surfaces in streets with concrete roads (of different albedo or emissivity characteristics) can lead up to a ~5 °C reduction in the canyon air temperature in dry climates. It is finally concluded that an optimized selection of materials in the urban infrastructure design can lead to a more effective mitigation of the UHI phenomenon than the optimisation of the built packing density.

Climate Change 2007: The Physical Science Basis.

Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.

2019 ESC Guidelines for the diagnosis and management of chronic coronary syndromes.

Abstract: Coronary artery disease (CAD) is a pathological process characterized by atherosclerotic plaque accumulation in the epicardial arteries, whether obstructive or non-obstructive. This process can be modified by lifestyle adjustments, pharmacological therapies, and invasive interventions designed to achieve disease stabilization or regression. The disease can have long, stable periods but can also become unstable at any time, typically due to an acute atherothrombotic event caused by plaque rupture or erosion. However, the disease is chronic, most often progressive, and hence serious, even in clinically apparently silent periods. The dynamic nature of the CAD process results in various clinical presentations, which can be conveniently categorized as either acute coronary syndromes (ACS) or chronic coronary syndromes (CCS). The Guidelines presented here refer to the management of patients with CCS. The natural history of CCS is illustrated in Figure 1.

Climate change 2014 - Mitigation of climate change

Abstract: The talk with present the key results of the IPCC Working Group III 5th assessment report. Concluding four years of intense scientific collaboration by hundreds of authors from around the world, the report responds to the request of the world's governments for a comprehensive, objective and policy neutral assessment of the current scientific knowledge on mitigating climate change. The report has been extensively reviewed by experts and governments to ensure quality and comprehensiveness.