A robust method for measuring the Hubble parameter

We obtain a robust, non-parametric, estimate of the Hubble constant from galaxy linear diameters calibrated using HST Cepheid distances. Our method is independent of the parametric form of the diameter function and the spatial distribution of galaxies and is insensitive to Malmquist bias. We include information on the galaxy rotation velocities; unlike Tully-Fisher, however, we retain a fully non-parametric treatment. We find $H_0=66\pm6$ km/s/Mpc, somewhat larger than previous results using galaxy diameters.Comment: 4 pages, 1 figure, Cosmic Flows Workshop, Victoria B.C. Canada, July 1999, ed. S. Courteau, M. Strauss & J. Willick, ASP conf. serie

Deep space network

Background, current status, and sites of Deep Space Network stations are briefly discussed

Adsorption and binding dynamics of graphene-supported phospholipid membranes using the QCM-D technique

We report on the adsorption dynamics of phospholipid membranes on graphene-coated substrates using the quartz crystal microbalance with dissipation monitoring (QCM-D) technique. We compare the lipid vescle interaction and membranne formation on gold and silicon dioxide QCM crystal surfaces with their graphene oxide (GO) and reduced (r)GO coated counterparts, and report on the different lipid structures obtained. We establish graphene derivative coatings as support surfaces with tuneable hydrophobicity for the formation of controllable lipid structures. One structure of interest formed are lipid monolayer membrannes which were formed on rGO, which are otherwise challenging to produce. We also demonstrate and monitor biotin-avidin binding on such a membranne, which will then serve as a platform for a wide range of biosensing applications. The QCM-D technique could be extended to both fundamental studies and applications of other covalent and non-covalent interactions in 2-dimensional materials

Simulating star formation in molecular cloud cores IV. The role of turbulence and thermodynamics

We perform SPH simulations of the collapse and fragmentation of low-mass cores having different initial levels of turbulence (alpha_turb=0.05,0.10,0.25). We use a new treatment of the energy equation which captures the transport of cooling radiation against opacity due to both dust and gas (including the effects of dust sublimation, molecules, and H^- ions). We also perform comparison simulations using a standard barotropic equation of state. We find that -- when compared with the barotropic equation of state -- our more realistic treatment of the energy equation results in more protostellar objects being formed, and a higher proportion of brown dwarfs; the multiplicity frequency is essentially unchanged, but the multiple systems tend to have shorter periods (by a factor ~3), higher eccentricities, and higher mass ratios. The reason for this is that small fragments are able to cool more effectively with the new treatment, as compared with the barotropic equation of state. We find that the process of fragmentation is often bimodal. The first protostar to form is usually, at the end, the most massive, i.e. the primary. However, frequently a disc-like structure subsequently forms round this primary, and then, once it has accumulated sufficient mass, quickly fragments to produce several secondaries. We believe that this delayed fragmentation of a disc-like structure is likely to be an important source of very low-mass hydrogen-burning stars and brown dwarfs.Comment: 14 pages, 8 figures. Accepted for publication by A&

Creative User-Centered Visualization Design for Energy Analysts and Modelers

We enhance a user-centered design process with techniques that deliberately promote creativity to identify opportunities for the visualization of data generated by a major energy supplier. Visualization prototypes developed in this way prove effective in a situation whereby data sets are largely unknown and requirements open – enabling successful exploration of possibilities for visualization in Smart Home data analysis. The process gives rise to novel designs and design metaphors including data sculpting. It suggests: that the deliberate use of creativity techniques with data stakeholders is likely to contribute to successful, novel and effective solutions; that being explicit about creativity may contribute to designers developing creative solutions; that using creativity techniques early in the design process may result in a creative approach persisting throughout the process. The work constitutes the first systematic visualization design for a data rich source that will be increasingly important to energy suppliers and consumers as Smart Meter technology is widely deployed. It is novel in explicitly employing creativity techniques at the requirements stage of visualization design and development, paving the way for further use and study of creativity methods in visualization design

Emergence of long-range order in BaTiO3 from local symmetry-breaking distortions

By using a symmetry motivated basis to evaluate local distortions against pair distribution function data (PDF), we show without prior bias, that the off-centre Ti displacements in the archetypal ferroelectric BaTiO3 are zone centred and rhombohedral-like in nature across its known ferroelectric and paraelectric phases. With our newly-gained insight we construct a simple Monte Carlo (MC) model which captures our main experimental findings and demonstrate how the rich crystallographic phase diagram of BaTiO3 emerges from correlations of local symmetry-breaking distortions alone. Our results strongly support the order-disorder picture for these phase transitions, but can also be reconciled with the soft-mode theory of BaTiO3 that is supported by some spectroscopic techniques.Comment: 5 pages, 3 figure

Smarter choices - changing the way we travel

Summary: In recent years, there has been growing interest in a range of initiatives, which are now widelydescribed as 'soft' transport policy measures. These seek to give better information and opportunities,aimed at helping people to choose to reduce their car use while enhancing the attractiveness ofalternatives. They are fairly new as part of mainstream transport policy, mostly relativelyuncontroversial, and often popular. They include:. Workplace and school travel plans;. Personalised travel planning, travel awareness campaigns, and public transport information andmarketing;. Car clubs and car sharing schemes;. Teleworking, teleconferencing and home shopping.This report draws on earlier studies of the impact of soft measures, new evidence from the UK andabroad, case study interviews relating to 24 specific initiatives, and the experience of commercial,public and voluntary stakeholders involved in organising such schemes. Each of the soft factors isanalysed separately, followed by an assessment of their combined potential impact.The assessment focuses on two different policy scenarios for the next ten years. The 'high intensity'scenario identifies the potential provided by a significant expansion of activity to a much morewidespread implementation of present good practice, albeit to a realistic level which still recognisesthe constraints of money and other resources, and variation in the suitability and effectiveness of softfactors according to local circumstances. The 'low intensity' scenario is broadly defined as aprojection of the present (2003-4) levels of local and national activity on soft measures.The main features of the high intensity scenario would be. A reduction in peak period urban traffic of about 21% (off-peak 13%);. A reduction of peak period non-urban traffic of about 14% (off-peak 7%);. A nationwide reduction in all traffic of about 11%.These projected changes in traffic levels are quite large (though consistent with other evidence onbehavioural change at the individual level), and would produce substantial reductions in congestion.However, this would tend to attract more car use, by other people, which could offset the impact ofthose who reduce their car use unless there are measures in place to prevent this. Therefore, thoseexperienced in the implementation of soft factors locally usually emphasise that success depends onsome or all of such supportive policies as re-allocation of road capacity and other measures toimprove public transport service levels, parking control, traffic calming, pedestrianisation, cyclenetworks, congestion charging or other traffic restraint, other use of transport prices and fares, speedregulation, or stronger legal enforcement levels. The report also records a number of suggestionsabout local and national policy measures that could facilitate the expansion of soft measures.The effects of the low intensity scenario, in which soft factors are not given increased policy prioritycompared with present practice, are estimated to be considerably less than those of the high intensityscenario, including a reduction in peak period urban traffic of about 5%, and a nationwide reductionin all traffic of 2%-3%. These smaller figures also assume that sufficient other supporting policies areused to prevent induced traffic from eroding the effects, notably at peak periods and in congestedconditions. Without these supportive measures, the effects could be lower, temporary, and perhapsinvisible.Previous advice given by the Department for Transport in relation to multi-modal studies was that softfactors might achieve a nationwide traffic reduction of about 5%. The policy assumptionsunderpinning this advice were similar to those used in our low intensity scenario: our estimate isslightly less, but the difference is probably within the range of error of such projections.The public expenditure cost of achieving reduced car use by soft measures, on average, is estimated atabout 1.5 pence per car kilometre, i.e. £15 for removing each 1000 vehicle kilometres of traffic.Current official practice calculates the benefit of reduced traffic congestion, on average, to be about15p per car kilometre removed, and more than three times this level in congested urban conditions.Thus every £1 spent on well-designed soft measures could bring about £10 of benefit in reducedcongestion alone, more in the most congested conditions, and with further potential gains fromenvironmental improvements and other effects, provided that the tendency of induced traffic to erodesuch benefits is controlled. There are also opportunities for private business expenditure on some softmeasures, which can result in offsetting cost savings.Much of the experience of implementing soft factors is recent, and the evidence is of variable quality.Therefore, there are inevitably uncertainties in the results. With this caveat, the main conclusion isthat, provided they are implemented within a supportive policy context, soft measures can besufficiently effective in facilitating choices to reduce car use, and offer sufficiently good value formoney, that they merit serious consideration for an expanded role in local and national transportstrategy.AcknowledgementsWe gratefully acknowledge the many contributions made by organisations and individuals consultedas part of the research, and by the authors of previous studies and literature reviews which we havecited. Specific acknowledgements are given at the end of each chapter.We have made extensive use of our own previous work including research by Lynn Sloman funded bythe Royal Commission for the Exhibition of 1851 on the traffic impact of soft factors and localtransport schemes (in part previously published as 'Less Traffic Where People Live'); and by SallyCairns and Phil Goodwin as part of the research programme of TSU supported by the Economic andSocial Research Council, and particularly research on school and workplace travel plans funded bythe DfT (and managed by Transport 2000 Trust), on car dependence funded by the RAC Foundation,on travel demand analysis funded by DfT and its predecessors, and on home shopping funded byEUCAR. Case studies to accompany this report are available at: http://eprints.ucl.ac.uk/archive/00001233