8 research outputs found
Air Pollution Exposure During Pregnancy, Ultrasound Measures of Fetal Growth, and Adverse Birth Outcomes: A Prospective Cohort Study
Background: Air pollution exposure during pregnancy might have trimester-specific effects on fetal growth
On the Automatic Guidance System with Crab-Steering
Among the steering modes of farm tractor, the crab-steering has hardly been taken up in production and also in research. That mode of steering may be unapplicable to manual operating that has made familiar with normal mode of steering for long time, but because the vehicle with that mode can always hold its body in a certine direction, that type has a profitable property for the automatic guidance in field operation, and positional relation of sensor and implement is one-dimensional problem and attaching point of sensor to body is unrestricted. This type vehicle can not turn, but travelling of field operation necessitates no turning in many kinds of operations except at head land. At head land, it may be solved to change steering mode. The authors aspect to the property of crab-steering and aimed to develop the automatic guidance system with this steering mode. In this paper, the stability of relay-control system of automatic guidance was considered with describing-function method, and the results of tracking tests with trial vehicle were discussed and considered by means of time varying Fourier coefficients of tracking pass
Chronic Air Pollution Exposure during Pregnancy and Maternal and Fetal C-Reactive Protein Levels: The Generation R Study
Background: Exposure to air pollution has been associated with higher C-reactive protein (CRP) levels, suggesting an inflammatory response. Not much is known about this association in pregnancy
Air pollution exposure estimation using dispersion modelling and continuous monitoring data in a prospective birth cohort study in the Netherlands
Previous studies suggest that pregnant women and children are particularly vulnerable to the adverse effects of air pollution. A prospective cohort study in pregnant women and their children enables identification of the specific effects and critical periods. This paper describes the design of air pollution exposure assessment for participants of the Generation R Study, a population-based prospective cohort study from early pregnancy onwards in 9778 women in the Netherlands. Individual exposures to PM10 and NO2 levels at the home address were estimated for mothers and children, using a combination of advanced dispersion modelling and continuous monitoring data, taking into account the spatial and temporal variation in air pollution concentrations. Full residential history was considered. We observed substantial spatial and temporal variation in air pollution exposure levels. The Generation R Study provides unique possibilities to examine effects of short- and long-term air pollution exposure on various maternal and childhood outcomes and to identify potential critical windows of exposure
Modeling of pollutant dispersion in street canyon by means of CFD
Nowadays, pollution from traffic remains one of the major sources for contamination in
urban areas and it is widely known that substances emitted by vehicles represent a serious hazard to
human health; some traffic-related pollutants, such as NO, NOx and CO are responsible for both acute
and chronic effects on human health. This is often the case near busy traffic axis in city centers or
street canyons. Purpose of this work is to validate the CFD model predictions against the field
measurements of pollutants dispersion in an actual urban environment: Göttinger Strasse, Hanover,
Germany. In the location, the population exposure to traffic-related pollution is expected to be high.
Steady-state simulations have been performed for 18 different wind directions, with an increment of
20°, in order to cover the whole wind rose. A grid and a Schmidt number sensitivity analysis have
been carried out in order to determine both the most suitable resolution of the computational geometry
and the most suitable parameter to model the turbulence conditions in the street canyon. All CFD
simulations have been performed for neutral atmospheric conditions and have been carried out with
the CFD code FLUENT 12.1