Search results for "Diesel exhaust"

Nucleation particles in diesel exhaust: composition inferred from in situ mass spectrometric analysis.

2005

Mass spectrometric measurements of size and composition of diesel exhaust particles have been performed under various conditions: chassis dynamometer tests, field measurements near a German motorway, and individual car chasing. Nucleation particles consisting of volatile sulfate and organic material could be detected both at the chassis dynamometer test facility and during individual car chasing. We found evidence that if nucleation occurs, sulfuric acid/water is the nucleating agent. Low-volatile organics species condense only on the preexisting sulfuric acid/water clusters. Nucleation was found to depend strongly on various parameters such as exhaust dilution conditions, fuel sulfur conte…

Transition Metal Compound Oxide Catalysts for Lowering the Light Off-Temperature of Particles from Diesel Exhaust

1993

Publisher Summary It has been realized that particle emissions from diesel engines are a severe environmental problem, which is difficult to solve by engine modifications alone. Even if the combustion occurs in a high excess of air, appreciable amounts of soot particles are found. Cracking processes, dehydrogenation, and polymerization play an important role in the formation of soot. To reduce soot fraction, several methods have been developed in the past, but most of them have fundamental disadvantages. Thus, a new procedure based on the catalytic burning of the soot in the exhaust gas is becoming important. This chapter describes the effect of several compound oxides. Further investigatio…

Characterization of Diesel Soot by Sedimentation Field Flow Fractionation

1990

Air Pollution During Pregnancy and Childhood Cognitive and Psychomotor Development: Six European Birth Cohorts

2014

Background: Accumulating evidence from laboratory animal and human studies suggests that air pollution exposure during pregnancy affects cognitive and psychomotor development in childhood. Methods: We analyzed data from 6 European population-based birth cohorts-GENERATI ON R (The Netherlands), DUISBURG (Germany), EDEN (France), GASPII (Italy), RHEA (Greece), and INMA (Spain)-that recruited mother-infant pairs from 1997 to 2008. Air pollution levels-nitrogen oxides (NO2, NOx) in all regions and particulate matter (PM) with diameters of <2.5, <10, and 2.5-10 mu m (PM2.5, PM10, and PMcoarse, respectively) and PM2.5 absorbance in a subgroup-at birth addresses were estimated by land-use regressi…

Soot particle properties in the microwave range

1993

This paper outlines the study of Diesel soot particle properties in the frequency band 2.0-40.0 GHz. Using a transmission/reflection as well as a cavity perturbation method, the complex dielectric constant ?* = ?1 - j?2 was measured for multiple of samples (soot particles produced in a Diesel engine and deposited on paper filter). From the analysis of the experimental data the following conclusions appear: The complex dielectric constant - i.e. the HF electrical conductivity and the microwave power absorption efficiency - are dependent on the frequency and the soot particle thickness. Increasing the soot particle thickness causes the reflection to be stronger and results in less influence o…