41 research outputs found
Internal dose of particles in the elderly: modeling based on aerosol measurements
The paper presents an integrated methodology that combines experimental and modeling techniques and links exposure to airborne particulate matter (PM) with internal dose in the respiratory system and burden in adjacent tissues over a period of time. The methodology is used to estimate doses in the respiratory systems of elders that reside in 10 elderly care centers (ECCs) in the metropolitan area of Lisbon. Measurements of PM were performed in the ECCs and combined with a time-budget survey for the occupants. This information served as input to the first model that estimated particle doses in the different regions of the respiratory tract of the elderly, and then a second model was used to calculate particle build-up in the alveolar region, the interstitium and the hilar lymph nodes of the elders over a 5-year exposure period. It was found that in 5 years of continuous exposure to the average particle concentration measured over all ECCs, 258 mg of all particles are deposited on the surface of the alveoli of which 79.6% are cleared, 18.8% are retained in the alveolar region, 1.5% translocate to the hilar lymph nodes, and 0.1% are transferred to the interstitium.info:eu-repo/semantics/publishedVersio
Facilitating knowledge transfer: decision support tools in environment and health
The HENVINET Health and Environment Network aimed to enhance the use of scientific knowledge in environmental health for policy making. One of the goals was to identify and evaluate Decision Support Tools (DST) in current use. Special attention was paid to four “priority” health issues: asthma and allergies, cancer, neurodevelopment disorders, and endocrine disruptors
Thermophoretic Deposition in Tube Flow
Thermophoretic deposition in laminar and turbulent circularpipe
flows is investigated. One-dimensional (1D) Eulerian and twodimensional
(2D) Eulerian and Lagrangian models are developed.
In 1D models the importance of correct reference scales is demonstrated.
A 1D universal expression for the thermophoretic deposition
efficiency in a long tube is derived that is valid for laminar
and turbulent flows and that gives excellent agreement with previous
empirical correlations and theoretical results.Two-dimensional
models incorporating radial-profile effects are developed to assess
the effectiveness of the 1D approach. The 2D modelling is based
on a nonstochastic Lagrangian methodology that allows the calculation
of thermophoretic deposition with computationally inexpensive
means. The developed models are extensively validated by
comparing their predictions to experimental results, previous numerical
calculations, and theoretical results in laminar and turbulent
flows. The models are also used to calculate thermophoretic
deposition in large-scale experiments simulating fission-product
behavior during a postulated severe accident at a nuclear power
plant. It is found that in laminar flow a properly constructed 1D
description provides accurate predictions. In turbulent flow1Dand
2D predictions provide the same degree of accuracy, unless large
bulk gas-to-wall temperature differences prevail where the more
detailed 2D approach offers significant improvement.JRC.H.4-Transport and air qualit
The Effect of Pulse Operation on Tritium Permeation and Inventory in ITER's Plasma-Facing Components.
Abstract not availableJRC.(EI)-Environment Institut
Dehumidification of Air Flow through Cooling at Sub-Freezing Temperatures.
An experimental and numerical study is presented in which laminar air flow with low water-vapour concentration is cooled at temperatures well below 0* C to remove the humidity contained in the carrier gas. The experiment uses a cold trap that consists of a vertical tube-bundle immersed in a cold shell. The analysis is carried out with the help of a model that simulates heat and mass transfer, as well as aerosol dynamics in the tube flow. It is found that an optimal temperature range exists for the efficiency of the process. The results are interpreted in terms of the competition between vapour diffusion to the wall and ice particle formation and growth.JRC.(ISIS)-Institute For Systems, Informatics And Safet
Combined Heat and Mass Transfer in Laminar Flow Diffusion Nucleation Chambers.
Abstract not availableJRC.H-Institute for environment and sustainability (Ispra
Effect of Small-Scale Turbulent Fluctuations on Rates of Particle Formation.
Abstract not availableJRC.H-Institute for environment and sustainability (Ispra
Effect of Small-Scale Turbulent Fluctuations on Rates of Particle Formation.
Abstract not availableJRC.H-Institute for environment and sustainability (Ispra
Two-Dimensional Effects in Thermophoretic Particle Deposition: the PHEBUS-FP Steam Generator.
Abstract not availableJRC.(IAM)-Institute For Advanced Material