Volatile organic compounds in Wroclaw, Poland Source apportionment using chemical mass balance modelling technique

During the measurement campaign performed in August/September 2005 non-methane volatile organic compounds (NMVOCs) were studied at different locations in the city of Wroclaw, Poland. The measurements covered NMVOCs in the range of C-1 to Cu-10. Samples were collected using Carbotrap and Carbosieve SIII solid adsorption tubes and analysed off-line by thermal desorption and GC-FID analysis. Measurements were performed on purpose to assess the contribution of different emission categories to the observed NMVOC porfile by using chemical mass balance modelling (CMB). Profiles of NMVOCs for traffic emissions were measured in a downtown intersection and during driving through the city. Solvent emission profiles for industrial sources were measured in the vicinity of different factories in Wroclaw. To obtain the ambient NMVOC concentrations sampling was performed at different points located in Wroclaw. The sampling sites represented residential, industrial, mixed settings and an area down-wind from the city centre. The results of the present work show that traffic emissions rather than other sources determine the ambient NMVOC composition in the city. Traffic exhaust contributes approximately 99% to the NMVOC concentration in the city centre of Wroclaw and down-wind from the city. A significant influence of investigated industrial solvent emissions could only be observed in the close vicinity of the factories, where the contributions of solvent emissions were up to 90%

Particle Emissions from Aircraft Engines–A Survey of the European Project PartEmis

An overview of the goals and achievements of the European PartEmis project (Measurement and prediction of emissions of aerosols and gaseous precursors from gas turbine engines) is presented. PartEmis was focussed on the characterisation and quantification of exhaust emissions from a gas turbine engine. The engine was composed of a combustor and a unit to simulate a 3-shaft turbine section (so-called Hot End Simulator; HES). A comprehensive suite of aerosol, gas and chemi-ion measurements were conducted under different, i) combustor and HES operating conditions, ii) fuel sulphur concentrations. Measured aerosol properties were mass and number concentration, size distribution, mixing state, thermal stability of internally mixed particles, hygroscopicity, cloud condensation nuclei (CCN) activation potential, and chemical composition. Furthermore, chemi-ions, non-methane volatile organic compounds (NMVOCs) and OH were monitored. The combustor operation conditions corresponded to modern and older engine gas path temperatures at cruise altitude, with fuel sulphur contents (FSC) of 0.05, 0.41, and 1.270 g kg−1. The combustor behaved like a typical aircraft engine combustor with respect to thermodynamic data and main emissions, which suggests that the PartEmis database may be applicable to contemporary aircraft engines. The conclusions drawn from the PartEmis experiment are discussed separately for combustion particles, ultrafine particles, sulphate-containing species and chemi-ions, particle hygrioscopic growth and CCN activation, gaseous organic fraction, and emission properties

Identification and characterization of amphiphysin II as a novel cellular interaction partner of the hepatitis C virus NS5A protein

The hepatitis C virus (HCV) NS5A protein is highly phosphorylated by cellular protein kinases. To study how NS5A might be integrated in cellular kinase signalling, we isolated phosphoproteins from HuH-7 hepatoma cells that specifically interacted with recombinant NS5A protein. Subsequent mass spectrometry identified the adaptor protein amphiphysin II as a novel interaction partner of NS5A. Mutational analysis revealed that complex formation is primarily mediated by a proline-rich region in the C-terminal part of NS5A, which interacts with the amphiphysin II Src homology 3 domain. Importantly, we could further demonstrate specific co-precipitation and cellular co-localization of endogenous amphiphysin II with NS5A in HuH-7 cells carrying a persistently replicating subgenomic HCV replicon. Although the NS5A–amphiphysin II interaction appeared to be dispensable for replication of these HCV RNAs in cell culture, our results indicate that NS5A–amphiphysin II complex formation might be of physiological relevance for the HCV life cycle