Uncertainty of laboratory and portable solid particle number systems for regulatory measurements of vehicle emissions.

In the European Union's emissions regulations, limits for solid particles >23 nm are applicable for the type-approval and in use compliance of vehicles. Consequently, particle number (PN) systems are used very often for both research and development of engines and vehicles, both in the laboratory and on the road. The technical specifications of the laboratory and portable on-board systems are not the same resulting in different measurement uncertainties.

Comparisons of Laboratory and On-Road Type-Approval Cycles with Idling Emissions. Implications for Periodical Technical Inspection (PTI) Sensors.

For the type approval of compression ignition (diesel) and gasoline direct injection vehicles, a particle number (PN) limit of 6 × 10 p/km is applicable. Diesel vehicles in circulation need to pass a periodical technical inspection (PTI) test, typically every two years, after the first four years of circulation. However, often the applicable smoke tests or on-board diagnostic (OBD) fault checks cannot identify malfunctions of the diesel particulate filters (DPFs).

On-road emissions of passenger cars beyond the boundary conditions of the real-driving emissions test.

Passenger cars are an important source of air pollution, especially in urban areas. Recently, real-driving emissions (RDE) test procedures have been introduced in the EU aiming to evaluate nitrogen oxides (NOx) and particulate number (PN) emissions from passenger cars during on-road operation. Although RDE accounts for a large variety of real-world driving, it excludes certain driving situations by setting boundary conditions (e.

Evaluation of NO emissions of a retrofitted Euro 5 passenger car for the Horizon prize "Engine retrofit".

The Horizon 2020 prize for the "Engine Retrofit for Clean Air" aims at reducing the pollution in cities by spurring the development of retrofit technology for diesel engines. A Euro 5 passenger car was retrofitted with an under-floor SCR (Selective Catalytic Reduction) for NO catalyst in combination with a solid ammonia based dosing system as the NO reductant. The vehicle was tested both on the road and on the chassis dynamometer under various test cycles and ambient temperatures.

Framework for the assessment of PEMS (Portable Emissions Measurement Systems) uncertainty.

European regulation 2016/427 (the first package of the so-called Real-Driving Emissions (RDE) regulation) introduced on-road testing with Portable Emissions Measurement Systems (PEMS) to complement the chassis dynamometer laboratory (Type I) test for the type approval of light-duty vehicles in the European Union since September 2017. The Not-To-Exceed (NTE) limit for a pollutant is the Type I test limit multiplied by a conformity factor that includes a margin for the additional measurement uncertainty of PEMS relative to standard laboratory equipment. The variability of measured results related to RDE trip design, vehicle operating conditions, and data evaluation remain outside of the uncertainty margin.

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC).

Four light-duty vehicles (two diesel, one flex-fuel, and one gasoline vehicle) were tested as part of an intercomparison exercise of the world-harmonized light-duty vehicle test procedure (WLTP) aiming at measuring real-time ammonia emissions from the vehicles' raw exhaust at the tailpipe. The tests were conducted in the Vehicle Emission Laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC), Ispra, Italy. HORIBA, CGS, and the Sustainable Transport Unit of the Joint Research Centre (JRC) took part in the measurement and analysis of the four vehicles' exhaust emissions over the world-harmonized light-duty vehicle test cycle class 3, version 5.

Unequal functional redundancy between the two Arabidopsis thaliana high-affinity sulphate transporters SULTR1;1 and SULTR1;2.

* In Arabidopsis, SULTR1;1 and SULTR1;2 are two genes proposed to be involved in high-affinity sulphate uptake from the soil solution. We address here the specific issue of their functional redundancy for the uptake of sulphate and for the accumulation of its toxic analogue selenate with regard to plant growth and selenate tolerance. * Using the complete set of genotypes, including the wild-type, each one of the single sultr1;1 and sultr1;2 mutants and the resulting double sultr1;1-sultr1;2 mutant, we performed a detailed phenotypic analysis of root length, shoot biomass, sulphate uptake, sulphate and selenate accumulation and selenate tolerance.