2,813 research outputs found
PM2.5 dispersion in Venice area: a model validation
No full textA multidisciplinary project was developed with the aim of better understand PM2.5 primary sources and secondary aerosol formation and compositions. A model system was used to simulate four periods during different seasons in 2009 for which both organic and inorganic measured data were available. Input data were estimated and formatted as requested by models. Measured and predicted data were compared for the three stations and during different seasons in order to test model performance
EPHECT II: Exposure assessment to household consumer products
No full textWithin the framework of the EPHECT project (Emissions, exposure patterns and health effects of consumer products in the EU), irritative and respiratory health effects were assessed in relation to acute and long-term exposure to key and emerging indoor air pollutants emitted during household use of selected consumer products. In this context, inhalation exposure assessment was carried out for six selected 'target' compounds (acrolein, formaldehyde, benzene, naphthalene, d-limonene and α-pinene). This paper presents the methodology and the outcomes from the micro-environmental modelling of the 'target' pollutants following single or multiple use of selected consumer products and the subsequent exposure assessment. The results indicate that emissions from consumer products of benzene and α-pinene were not considered to contribute significantly to the EU indoor background levels, in contrast to some cases of formaldehyde and d-limonene emissions in Eastern Europe (mainly from cleaning products). The group of housekeepers in East Europe appears to experience the highest exposures to acrolein, formaldehyde and benzene, followed by the group of the retired people in North, who experiences the highest exposures to naphthalene and α-pinene. High exposure may be attributed to the scenarios developed within this project, which follow a 'most-representative worst-case scenario' strategy for exposure and health risk assessment. Despite the above limitations, this is the first comprehensive study that provides exposure estimates for 8 population groups across Europe exposed to 6 priority pollutants, as a result of the use of 15 consumer product classes in households, while accounting for regional differences in uses, use scenarios and ventilation conditions of each region
Mechanica op de microcomputer
No full textAfscheidscollege van prof.dr.ir. J.G. Lekkerkerker (informele notities)
Installatierede van de Technische Commissie voor de Waterkeringen
No full textRede uitgesproken bij de installatie van de Technische Adviescommissie voor de Waterkeringen door de Minister van Verkeer en Waterstaat, J.G. Suurhoff, en het antwoord van de voorzitter van de TAW op deze rede, prof.ir. P.P. Jansen. De commissie werd ingesteld naar aanleiding van de overstromingen in Tuindorp-Oostzaan in 1960. De commissie is officieel ingesteld op 31 mei 1965, maar de installatierede is in Augustus van dat jaar uitgesprokenTAW/EN
Implicit large-eddy simulation of the stratocumulus-topped boundary layer: A grid sensitivity study
No full textA range of implicit large-eddy simulations of the stratocumulus-topped boundary layer is performed to study the influence of grid resolution on selected parameters including liquid water path and second and third moments of vertical velocity fluctuations. The simulations are based on two sets of aircraft measurements, which are also used to evaluate the results of the simulations. The specific case presented here indicates that simulations with a grid aspect ratio accounting for the anisotropic nature of the turbulence near the surface and at the top of the boundary layer lead to better agreement with measurements than simulations with an isotropic grid
Experimental application of a dynamic observer to capture and predict the dynamics of a flat-plate boundary layer
No full textThe recent approach, proposed by Guzman-Inigo et al. \cite{GuzmanInigo2014}, using System Identification to derive a Reduced Order Model from snapshots of a flow is applied to a transitional boundary layer growing over a flat-plate. It is shown that such an approach can indeed be applied to experimental PIV snapshots. Using a proper learning dataset and a proper local sensor, it is shown that the evolution of boundary layer can be properly estimated from the time evolution of the local probe and with no more than ten POD modes for the Reduced Order Model. The influence of the various parameters on the efficiency of the system identification technique is discussed
Entering GATTACA: Yeast genomes: Analysis, insights and applications
No full textAccepted Author ManuscriptBT/Industriele Microbiologi
Hydrodynamic behavior of a bare rod bundle. [LMFBR]
No full textThe temperature distribution within the rod bundle of a nuclear reactor is of major importance in nuclear reactor design. However temperature information presupposes knowledge of the hydrodynamic behavior of the coolant which is the most difficult part of the problem due to complexity of the turbulence phenomena. In the present work a 2-equation turbulence model--a strong candidate for analyzing actual three dimensional turbulent flows--has been used to predict fully developed flow of infinite bare rod bundle of various aspect ratios (P/D). The model has been modified to take into account anisotropic effects of eddy viscosity. Secondary flow calculations have been also performed although the model seems to be too rough to predict the secondary flow correctly. Heat transfer calculations have been performed to confirm the importance of anisotropic viscosity in temperature predictions. All numerical calculations for flow and heat have been performed by two computer codes based on the TEACH code. Experimental measurements of the distribution of axial velocity, turbulent axial velocity, turbulent kinetic energy and radial Reynolds stresses were performed in the developing and fully developed regions. A 2-channel Laser Doppler Anemometer working on the Reference mode with forward scattering was used to perform the measurements in a simulated interior subchannel of a triangular rod array with P/D = 1.124. Comparisons between the analytical results and the results of this experiment as well as other experimental data in rod bundle array available in literature are presented. The predictions are in good agreement with the results for the high Reynolds numbers
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