A5017558579- Air Quality and Health Impacts
- Atmospheric chemistry and aerosols
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Physics of Superconductivity and Magnetism
- Scientific Measurement and Uncertainty Evaluation
- Advanced Measurement and Metrology Techniques
- Atmospheric aerosols and clouds
- Superconducting Materials and Applications
- Scientific Research and Discoveries
- Chemical Thermodynamics and Molecular Structure
- Advanced Condensed Matter Physics
- Atmospheric and Environmental Gas Dynamics
- ZnO doping and properties
- Statistical and numerical algorithms
- Magnetic and transport properties of perovskites and related materials
- Sensor Technology and Measurement Systems
- Magnetic properties of thin films
- Electronic and Structural Properties of Oxides
- Advanced Sensor Technologies Research
- Sugarcane Cultivation and Processing
- Advanced Chemical Sensor Technologies
- Global Energy Security and Policy
- demographic modeling and climate adaptation
- Catalytic Processes in Materials Science
National Physical Laboratory
2013-2022
Teddington Memorial Hospital
1989-2017
Imperial College London
1995
University of Oxford
1987-1989
Science Oxford
1987
Abstract. Mobility particle size spectrometers often referred to as DMPS (Differential Particle Sizers) or SMPS (Scanning have found a wide range of applications in atmospheric aerosol research. However, comparability measurements conducted world-wide is hampered by lack generally accepted technical standards and guidelines with respect the instrumental set-up, measurement mode, data evaluation well quality control. Technical were developed for minimum requirement mobility spectrometry...
Abstract. In many large cities of Europe standard air quality limit values particulate matter (PM) are exceeded. Emissions from road traffic and biomass burning frequently reported to be the major causes. As a consequence these exceedances number plans, most them focusing on emissions reductions, have been implemented in last decade. spite this implementation, did not record decrease PM levels. Thus, is efficiency plans overestimated? Do contribute less than expected ambient levels urban...
Mobility particle size spectrometers (MPSS) belong to the essential instruments in aerosol science that determine number distribution (PNSD) submicrometer range. Following calibration procedures and target uncertainties against standards reference are suggested for a complete MPSS quality assurance program: (a) of CPC counting efficiency curve (within 5% plateau efficiency; within 1 nm 50% detection diameter), (b) sizing MPSS, using certified polystyrene latex (PSL) standard at 203 3%), (c)...
Abstract. A comparison exercise on thermal-optical elemental carbon/organic carbon (ECOC) analysers was carried out among 17 European laboratories. Contrary to previous exercises, the participants made use of an identical instrument set-up, after correcting for temperature offsets with application a recently developed calibration kit (Sunset Laboratory Inc, OR, US). Temperature reported by ranged from −93 +100 °C per step. Five filter samples and two sucrose solutions were analysed both...
Although particulate organic and elemental carbon (OC EC) are important constituents of the suspended atmospheric matter (PM), measurements OC EC much less common more uncertain than e.g. ionic components PM. In framework research infrastructures supported by European Union, actions have been undertaken to determine mitigate sampling artefacts, assess comparability data obtained in a network 10 observatories across Europe. Positive artefacts (from 0.4 2.8 μg C/m3) analytical discrepancies...
Abstract. The formation of black carbon fractal aggregates (BCFAs) from combustion and subsequent ageing involves several stages resulting in modifications particle size, morphology, composition over time. To understand quantify how each these influences the BC radiative forcing, optical properties BCFAs are modelled. Owing to high computational time involved numerical modelling, there some gaps terms data coverage knowledge regarding coated vary range different factors (size, shape,...
Atmospheric particulate black carbon has been linked to adverse health outcomes. Additional measurements would aid a better understanding of population exposure in epidemiological studies as well the success, or otherwise, relevant abatement technologies and policies. Two light absorption measurement methods particles collected on filters have applied four different types provide estimations concentrations. The ratio transmittance (lnI0/I) reflectance (lnR0/R) varied by filter type ranged...
The first page of this article is displayed as the abstract.
A standard method for measurements of organic carbon and elemental has been produced.
In this investigation, we summarize performance parameters of 24 TSI CPCs model 3772 and 9 3790 determined at the World Calibration Aerosol Centre Physics hosted by Leibniz Institute for Tropospheric Research. Model are basically identical to laminar continuous flow type butanol-based with a modified temperature difference between saturator condenser. The average 50% detection efficiency silver particles instruments was found be 7.52 ± 0.04 nm 24.34 0.29 (average mobility diameter standard...
R. C. Cass, H. D. Springall and P. G. Quincey, J. Chem. Soc., 1955, 1188 DOI: 10.1039/JR9550001188
The Attenuation Versus Evolved Carbon (AVEC) plot is a new way to represent thermal-optical organic carbon/elemental carbon (OC/EC) analysis data. accumulated concentration plotted against the attenuation (ln (I0/I)). Unlike thermogram, it provides information about sample properties rather than instantaneous instrument sensor status. can be used refine determination of OC and EC split point, either from consideration laser instability or transit time within instrument; investigate optical...
The concentration of nanometre-sized particles is frequently measured in terms particle number using well-established measuring instruments, e.g. condensation counters. Traceability for these measurements can be achieved by means calibrations an aerosol electrometer (AE) as a reference. A national metrology institutes (NMIs) and expert laboratories provide such calibrations, but the metrological basis at present not well established because equivalence between unit realizations has been...
Research into the role of volatile organic compounds (VOCs) in chemistry lower atmosphere has led to requirements for stable and accurate standard gas mixtures underpin long‐term monitoring global background polluted urban concentrations. We describe a novel method preparation containing thirty matrices nitrogen whole air. The estimated uncertainty amount fractions these is typically 2% (relative) typical stability better than 0.2% per annum. also report results comparison exercise between...
Abstract. Particle mobility size spectrometers often referred to as DMPS (Differential Mobility Sizers) or SMPS (Scanning have found a wide application in atmospheric aerosol research. However, comparability of measurements conducted world-wide is hampered by lack generally accepted technical standards with respect the instrumental set-up, measurement mode, data evaluation well quality control. This article results from several instrument intercomparison workshops within European...
This paper concludes that mass absorption cross-section (MAC) values in London, UK have changed over time. It provides possible explanations and highlights implications for the interpretation of long-term trends.