Learning about A level physics students’ understandings of particle physics using concept mapping

This paper describes a small-scale piece of research using concept mapping to elicit A level students' understandings of particle physics. Fifty-nine year 12 (16- and 17 year-old) students from two London schools participated. The exercise took place during school physics lessons. Students were instructed how to make a concept map and were provided with 24 topic-specific key words. Students' concept maps were analysed by identifying the knowledge propositions they represented, enumerating how many students had made each one, and by identifying errors and potential misconceptions, with reference to the specification they were studying. The only correct statement made by a majority of students in both schools was that annihilation takes place when matter and antimatter collide, although there was evidence that some students were unable to distinguish between annihilation and pair production. A high proportion of students knew of up, down and strange quarks, and that the electron is a lepton. However, some students appeared to have a misconception that everything is made of quarks. Students found it harder to classify tau particles than they did electrons and muons. Where students made incorrect links about muons and tau particles their concept maps suggested that they thought they were mesons or quarks

Remote sensing of carbon monoxide vehicle emissions

The University of Denver's remote sensor for automobile exhaust emissions has been used to obtain valid model year (defined here as the year of first registration) and emissions data from roadside locations in Middlesbrough and London. Mean carbon monoxide emissions have been plotted against model year to determine if there is a relationship between mean pollutant emissions and the age of the vehicle. The results initially showed a large degree of scatter and no inference, concerning age and emissions, could be made. This can be largely attributed to the older vehicles in the fleet. Older vehicles were then omitted from an additional investigation providing a much stronger relationship with R2 values of 0.88 being calculated for London and 0.77 for Middlesbrough. Analyses of model year fleet emissions were also undertaken. It was demonstrated that old vehicles do not contribute significantly to fleet emissions. Pre-1983 registered vehicles contributed only 9% of total fleet emissions in Middlesbrough and only 21% of total fleet emissions in London. It was also shown that the vast majority of fleet emissions come from a small number of highly polluting new vehicles (quintile 5). Quintile 5 for model year 1989 represented 140 vehicles (2% of the measured fleet) which contributed to 10.6% of fleet emissions at the Middlesbrough site

On the advantages of the use of the three-element detector system for measuring EDXRD patterns to follow the crystallisation of open-framework structures

Time-resolved energy-dispersive X-ray diffraction (EDXRD) studies, employing a new detector technology, of a range of crystallisations of open framework materials are described. We consider four distinct categories of phenomena where new information has been gained specifically from the use of the multi-element (as opposed to the single element) detector system. The systems investigated are: (a) the competitive formation of small-pore and large-pore aluminophosphates (AlPO's), and the effect of concentration of Co-II in the mother liquor (precursor gel) in directing the relative amounts of AlPO-18 (AEI) and chabazite (CHA) structures that are formed; (b) the influence of both template (structure directing) molecules and synthesis time on the stabilities of the AlPO-5 (AFI) structures; (c) a study of both the rate of formation of the open framework titanosilicate (ETS-10) structure and the dissociation rate of crystalline TiO2 used in the preparation of ETS-10; and (d) tracking of the intermediate formed during the synthesis of the gallophosphate structure known as ULM-3. The advantages of using a three-element detector configuration are illustrated