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Ice nucleation by fertile soil dusts: relative importance of mineral and biogenic components
(2014)Atmospheric Chemistry and PhysicsAgricultural dust emissions have been estimated to contribute around 20% to the global dust burden. In contrast to dusts from arid source regions, the ice-nucleating abilities of which have been relatively well studied, soil dusts from fertile sources often contain a substantial fraction of organic matter. Using an experimental methodology which is sensitive to a wide range of ice nucleation efficiencies, we have characterised the immersion ...Journal Article -
A fast operation of nanometer-scale metallic memristors: highly transparent conductance channels in Ag2S devices
(2014)NanoscaleThe nonlinear transport properties of nanometer-scale junctions formed between an inert metallic tip and an Ag film covered by a thin Ag2S layer are investigated. Suitably prepared samples exhibit memristive behavior with technologically optimal ON and OFF state resistances yielding to resistive switching on the nanosecond time scale. Utilizing point contact Andreev reflection spectroscopy, we studied the nature of electron transport in ...Journal Article -
Adults see vision to be more informative than it is
(2014)Quarterly Journal of Experimental PsychologyHumans gain a wide range of knowledge through interacting with the environment. Each aspect of our perceptual experiences offers a unique source of information about the world—colours are seen, sounds heard and textures felt. Understanding how perceptual input provides a basis for knowledge is thus central to understanding one's own and others’ epistemic states. Developmental research suggests that 5-year-olds have an immature understanding ...Journal Article -
The Pagami Creek smoke plume after long-range transport to the upper troposphere over Europe – aerosol properties and black carbon mixing state
(2014)Atmospheric Chemistry and PhysicsDuring the CONCERT 2011 field experiment with the DLR research aircraft Falcon, an enhanced aerosol layer with particle linear depolarization ratios of 6–8% at 532 nm was observed at altitudes above 10 km over northeast Germany on 16 September 2011. Dispersion simulations with HYSPILT suggest that the elevated aerosol layer originated from the Pagami Creek forest fire in Minnesota, USA, which caused pyro-convective uplift of particles and ...Journal Article -
Intercomparison and evaluation of global aerosol microphysical properties among AeroCom models of a range of complexity
(2014)Atmospheric Chemistry and PhysicsMany of the next generation of global climate models will include aerosol schemes which explicitly simulate the microphysical processes that determine the particle size distribution. These models enable aerosol optical properties and cloud condensation nuclei (CCN) concentrations to be determined by fundamental aerosol processes, which should lead to a more physically based simulation of aerosol direct and indirect radiative forcings. ...Journal Article -
Size distribution, mixing state and source apportionment of black carbon aerosol in London during wintertime
(2014)Atmospheric Chemistry and PhysicsBlack carbon aerosols (BC) at a London urban site were characterised in both winter- and summertime 2012 during the Clean Air for London (ClearfLo) project. Positive matrix factorisation (PMF) factors of organic aerosol mass spectra measured by a high-resolution aerosol mass spectrometer (HR-AMS) showed traffic-dominant sources in summer but in winter the influence of additional non-traffic sources became more important, mainly from solid ...Journal Article -
Variations in tropospheric submicron particle size distributions across the European continent 2008-2009
(2014)Atmospheric Chemistry and PhysicsCluster~analysis of particle number size distributions from~background sites across Europe~is presented. This generated a total of nine clusters of particle size distributions which could be further combined into two main groups, namely: a south-to-north category (four clusters) and a west-to-east category (five clusters). The first group was identified as most frequently being detected inside and around northern Germany and neighbouring ...Journal Article -
Plasmonic heating with near infrared resonance nanodot arrays for multiplexing optofluidic applications
(2014)RSC AdvancesIn this work, we show local laser-induced heating in fluids with gold nanodot arrays prepared by electron-beam lithography that cover resonances in the near infrared spectral range from 750 nm to 880 nm. We utilize two approaches to demonstrate thermal effects, solvent evaporation and flow stop, with a thermosensitive polymer solution. We show that with fluences as low as 4 μJ cm−2, significant heating of the nanostructures occurs in their ...Journal Article -
Volatile and intermediate volatility organic compounds in suburban Paris: variability, origin and importance for SOA formation
(2014)Atmospheric Chemistry and PhysicsMeasurements of gaseous and particulate organic carbon were performed during the MEGAPOLI experiments, in July 2009 and January–February 2010, at the SIRTA observatory in suburban Paris. Measurements comprise primary and secondary volatile organic compounds (VOCs), of both anthropogenic and biogenic origins, including C12–C16 n-alkanes of intermediate volatility (IVOCs), suspected to be efficient precursors of secondary organic aerosol ...Journal Article -
Size-selected gold clusters on porous titania as the most “gold-efficient” heterogeneous catalysts
(2014)Physical Chemistry Chemical PhysicsResearch on homogeneous and heterogeneous catalysis is indeed convergent and finds subnanometric particles to be at the heart of catalytically active species. Here, monodisperse gold clusters are deposited from the gas phase onto porous titania generating well-defined model systems and the resulting composite materials exhibit a sharp size-dependency on the number of gold atoms per cluster and exceptionally high-turnovers toward the ...Journal Article