Detection and emotional evaluation of an electric vehicle’s exterior sound in a simulated environment

Electric vehicles are quiet at low speeds and thus potentially pose a threat to pedestrians’ safety. Laws are formulating worldwide that mandate these vehicles emit sounds to alert the pedestrians of the vehicles’ approach. It is necessary that these sounds promote a positive perception of the vehicle brand, and understanding their impact on soundscapes is also important. Detection time of the vehicle sounds is an important measure to assess pedestrians’ safety. Emotional evaluation of these sounds influences assessment of the vehicle brand. Laboratory simulation is a new approach for evaluating exterior automotive sounds. This study describes the implementation of laboratory simulation to compare the detection time and emotional evaluation of artificial sounds for an electric vehicle. An Exterior Sound Simulator simulated audio-visual stimuli of an electric car passing a crossroad of a virtual town at 4.47 ms-1 (10 mph), from the perspective of a pedestrian standing at the crossroad. In this environment, 15 sounds were tested using experiments where participants detected the car and evaluated its sound using perceptual dimensions. Results show that these sounds vary significantly in their detection times and emotional evaluations, but crucially that traditional metrics like dB(A) do not always relate to the detection of these sounds. Detection time and emotional evaluation do not have significant correlation. Hence, sounds of a vehicle could be detected quickly, but may portray negative perceptions of the vehicle. Simulation provides a means to more fully evaluate potential electric vehicle sounds against the competing criteria

The industrial pollution projection system

The World Bank's technical assistance work with new environmental protection institutions stresses cost-effective regulation, with market-based pollution control instruments implemented wherever feasible. But few environmental protection institutions can do the benefit-cost analysis needed because they lack data on industrial emissions and abatement costs. For the time being, they must use appropriate estimates. The industrial pollution projection system (IPPS) is being developed as a comprehensive response to this need for estimates. The estimation of IPPS parameters is providing a much clearer, more detailed view of the sources of industrial pollution. The IPPS has been developed to exploit the fact that industrial pollution is heavily affected by the scale of industrial activity, by its sectoral composition, and by the type of process technology used in production. Most developing countries have little or no data on industrial pollution, but many of them have relatively detailed industry-survey information on employment, value added, or output. The IPPS is designed to convert this information to a profile of associated pollutant output for countries, regions, urban areas, or proposed new projects. It operates through sectoral estimates of pollution intensity, or pollution per unit of activity. The IPPS is being developed in two phases. The first prototype has been estimated from a massive U.S. data base developed by the Bank's Policy Research Department, Environment, Infrastructure, and Agriculture Division, in collaboration with the Center for Economic Studies of the U.S. Census Bureau and the U.S. Environmental Protection Agency. This database was created by merging manufacturing census data with Environment Protection Agency data on air, water, and solid waste emissions. It draws on environmental, economic, and geographic information from about 200,000 U.S. factories. The IPPS covers about 1,500 product categories, all operating technologies, and hundreds of pollutants. It can project air, water, or solid waste emissions, and it incorporates a range of risk factors for human toxins and ecotoxic effects. The more ambitious second phase of IPPS development will take into account cross-country and cross-regional variations in relative prices, economic and sectoral policies, and strictness of regulation.Water and Industry,Environmental Economics&Policies,Public Health Promotion,Health Monitoring&Evaluation,Sanitation and Sewerage,Water and Industry,Environmental Economics&Policies,Health Monitoring&Evaluation,Sanitation and Sewerage,TF030632-DANISH CTF - FY05 (DAC PART COUNTRIES GNP PER CAPITA BELOW USD 2,500/AL

Time-reversal symmetry breaking in noncentrosymmetric superconductor Re6Hf:further evidence for unconventional behaviour in the alpha-Mn family of materials

The discovery of new families of unconventional superconductors is important both experimentally and theoretically, especially if it challenges current models and thinking. By using muon spin relaxation in zero-field, time-reversal symmetry breaking has been observed in Re6Hf. Moreover, the temperature dependence of the superfluid density exhibits s-wave superconductivity with an enhanced electron-phonon coupling. This, coupled with the results from isostructural Re6Zr, shows that the Re6X family are indeed a new and important group of unconventional superconductors.Comment: 5 pages, 2 figures Accepted Physical Review B, Rapid Communicatio

Crystal growth and properties of the non-centrosymmetric superconductor, Ru7B3

We describe the crystal growth of high quality single crystals of the non-centrosymmetric superconductor, Ru7B3 by the floating zone technique, using an optical furnace equipped with xenon arc lamps. The crystals obtained are large and suitable for detailed measurements, and have been examined using x-ray Laue patterns. The superconducting properties of the crystals obtained have been investigated by magnetisation and resistivity measurements. Crystals have also been grown starting with enriched 11B isotope, making them suitable for neutron scattering experiments.Comment: 4 pages, 5 figures. Accepted for publication in Journal of Crystal Growt

Superconducting and normal-state properties of the noncentrosymmetric superconductor Re6Zr

We systematically investigate the normal and superconducting properties of non-centrosymmetric Re$_{6}$Zr using magnetization, heat capacity, and electrical resistivity measurements. Resistivity measurements indicate Re$_{6}$Zr has poor metallic behavior and is dominated by disorder. Re$_6$Zr undergoes a superconducting transition at $T_{\mathrm{c}} = \left(6.75\pm0.05\right)$ K. Magnetization measurements give a lower critical field, $\mu_{0}H_{\mathrm{c1}} = \left(10.3 \pm 0.1\right)$ mT. The Werthamer-Helfand-Hohenberg model is used to approximate the upper critical field $\mu_{0}H_{\mathrm{c2}} = \left(11.2 \pm 0.2\right)$ T which is close to the Pauli limiting field of 12.35 T and which could indicate singlet-triplet mixing. However, low-temperature specific-heat data suggest that Re$_{6}$Zr is an isotropic, fully gapped s-wave superconductor with enhanced electron-phonon coupling. Unusual flux pinning resulting in a peak effect is observed in the magnetization data, indicating an unconventional vortex state.Comment: 11 pages, 7 figures, 2 table

Probing the superconducting ground state of the noncentrosymmetric superconductors CaTSi3 (T = Ir, Pt) using muon-spin relaxation and rotation

The superconducting properties of CaTSi3 (where T = Pt and Ir) have been investigated using muon spectroscopy. Our muon-spin relaxation results suggest that in both these superconductors time-reversal symmetry is preserved, while muon-spin rotation data show that the temperature dependence of the superfluid density is consistent with an isotropic s-wave gap. The magnetic penetration depths and upper critical fields determined from our transverse-field muon-spin rotation spectra are found to be 448(6) and 170(6) nm, and 3800(500) and 1700(300) G, for CaPtSi3 and CaIrSi3 respectively. The superconducting coherence lengths of the two materials have also been determined and are 29(2) nm for CaPtSi3 and 44(4) nm for CaIrSi3.Comment: 6 pages, 7 figure

Towards a methodology for assessing electric vehicle exterior sounds

Laws mandate that electric vehicles emit sounds to ensure pedestrians' safety by alerting pedestrians of the vehicles' approach. Additionally, manufacturers want these sounds to promote positive impressions of the vehicle brand. A reliable and valid methodology is needed to evaluate electric vehicles' exterior sounds. To help develop such a methodology, this paper examines automotive exterior sound evaluation methods in the context of experimental design and cognitive psychology. Currently, such evaluations are usually conducted on road or inside a laboratory; however, a virtual environment provides advantages of both these methods but none of their limitations. The stimuli selected for evaluations must satisfy legislative guidelines. Methods for presenting and measuring the stimuli can affect study outcomes. A methodology is proposed for conducting evaluations of an electric vehicle's exterior sounds, testing its detectability and emotional evaluation. An experiment tested the methodology. Thirty-one participants evaluated an electric car in a virtual environment of a town's T-junction with 15 exterior sounds as stimuli. The car's arrival time, direction of approach, and, thus, distance to pedestrian varied across conditions. Detection time of the sound and pleasantness and powerfulness evaluations of the car were recorded. The vehicle's arrival time and approach direction affected its detectability and emotional evaluation; thus, these are important elements to vary and control in studies. Overall, the proposed methodology increases the realistic context and experimental control than in existing listening evaluations. It benefits by combining two competing elements necessary for assessing electric vehicle exterior sounds, namely, pedestrians' safety and impressions of the vehicle brand