639 research outputs found

    Risk assessment applied to comsumer products with reference to CE marking machines for use at work

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    New Approach’ Directives now govern the health and safety of most products whether destined for workplace or domestic use. These Directives have been enacted into UK law by various specific legislation principally relating to work equipment, machinery and consumer products. This research investigates whether the risk assessment approach used to ensure the safety of machinery may be applied to consumer products. Crucially, consumer products are subject to the Consumer Protection Act (CPA) 1987, where there is no direct reference to “assessing risk”. This contrasts with the law governing the safety of products used in the workplace, where risk assessment underpins the approach. New Approach Directives are supported by European harmonised standards, and in the case of machinery, further supported by the risk assessment standard, EN 1050. The system regulating consumer product safety is discussed, its key elements identified and a graphical model produced. This model incorporates such matters as conformity assessment, the system of regulation, near miss and accident reporting. A key finding of the research is that New Approach Directives have a common feature of specifying essential performance requirements that provide a hazard prompt-list that can form the basis for a risk assessment (the hazard identification stage). Drawing upon 272 prosecution cases, and with thirty examples examined in detail, this research provides evidence that despite the high degree of regulation, unsafe consumer products still find their way onto the market. The research presents a number of risk assessment tools to help Trading Standards Officers (TSOs) prioritise their work at the initial inspection stage when dealing with subsequent enforcement action

    Long-time asymptotics of the long-range Emch-Radin model

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    The long-time asymptotic behavior is studied for a long-range variant of the Emch-Radin model of interacting spins. We derive upper and lower bounds on the expectation values of a class of observables. We prove analytically that the time scale at which the system relaxes to equilibrium diverges with the system size N, displaying quasistationary nonequilibrium behavior. This finding implies that, for large enough N, equilibration will not be observed in an experiment of finite duration.Comment: 12 pages, 2 figures. Compared to the published version, a 1/2 has been corrected in Eq. (9) and subsequent equations; the modifications are insubstantial and leave the main results of the article unaltered. arXiv admin note: substantial text overlap with arXiv:1103.083

    Hydrodynamics of thermal granular convection

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    A hydrodynamic theory is formulated for buoyancy-driven ("thermal") granular convection, recently predicted in molecular dynamic simulations and observed in experiment. The limit of a dilute flow is considered. The problem is fully described by three scaled parameters. The convection occurs via a supercritical bifurcation, the inelasticity of the collisions being the control parameter. The theory is expected to be valid for small Knudsen numbers and nearly elastic grain collisions.Comment: 4 pages, 4 EPS figures, some details adde

    Analysis of Ωb(bss)\Omega_b^-(bss) and Ωc0(css)\Omega_c^0(css) with QCD sum rules

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    In this article, we calculate the masses and the pole residues of the 1/2+{1/2}^+ heavy baryons Ωc0(css)\Omega_c^0(css) and Ωb(bss)\Omega_b^-(bss) with the QCD sum rules. The numerical values MΩc0=(2.72±0.18)GeVM_{\Omega_c^0}=(2.72\pm0.18) \rm{GeV} (or MΩc0=(2.71±0.18)GeVM_{\Omega_c^0}=(2.71\pm0.18) \rm{GeV}) and MΩb=(6.13±0.12)GeVM_{\Omega_b^-}=(6.13\pm0.12) \rm{GeV} (or MΩb=(6.18±0.13)GeVM_{\Omega_b^-}=(6.18\pm0.13) \rm{GeV}) are in good agreement with the experimental data.Comment: 18 pages, 18 figures, slight revisio

    Molybdenum blue nano-rings: an effective catalyst for the partial oxidation of cyclohexane

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    Molybdenum blue (MB), a multivalent molybdenum oxide with a nano-ring morphology is well-known in analytical chemistry but, to date it has been largely ignored in other applications. In the present work, MB has been characterized by STEM-HAADF imaging for the first time, showing the nano-ring morphology of this complex molybdenum oxide and the ordered super-molecular framework crystals that can result from the self-assembly of these MB nano-ring units. The potential of MB as an oxidation catalyst has also been investigated, where it is shown to have excellent catalytic activity and stability in the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone which are important intermediates in the production of nylon

    Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star

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    A search of the time-series photometry from NASA's Kepler spacecraft reveals a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626 with a period of 290 days. The characteristics of the host star are well constrained by high-resolution spectroscopy combined with an asteroseismic analysis of the Kepler photometry, leading to an estimated mass and radius of 0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the planet. The system passes a battery of tests for false positives, including reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A full BLENDER analysis provides further validation of the planet interpretation by showing that contamination of the target by an eclipsing system would rarely mimic the observed shape of the transits. The final validation of the planet is provided by 16 radial velocities obtained with HIRES on Keck 1 over a one year span. Although the velocities do not lead to a reliable orbit and mass determination, they are able to constrain the mass to a 3{\sigma} upper limit of 124 MEarth, safely in the regime of planetary masses, thus earning the designation Kepler-22b. The radiative equilibrium temperature is 262K for a planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is a rocky planet, it is the first confirmed planet with a measured radius to orbit in the Habitable Zone of any star other than the Sun.Comment: Accepted to Ap

    Lady Gaga as (dis)simulacrum of monstrosity

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    Lady Gaga’s celebrity DNA revolves around the notion of monstrosity, an extensively researched concept in postmodern cultural studies. The analysis that is offered in this paper is largely informed by Deleuze and Guattari’s notion of monstrosity, as well as by their approach to the study of sign-systems that was deployed in A Thousand Plateaus. By drawing on biographical and archival visual data, with a focus on the relatively underexplored live show, an elucidation is afforded of what is really monstrous about Lady Gaga. The main argument put forward is that monstrosity as sign seeks to appropriate the horizon of unlimited semiosis as radical alterity and openness to signifying possibilities. In this context it is held that Gaga effectively delimits her unique semioscape; however, any claims to monstrosity are undercut by the inherent limits of a representationalist approach in sufficiently engulfing this concept. Gaga is monstrous for her community insofar as she demands of her fans to project their semiosic horizon onto her as a simulacrum of infinite semiosis. However, this simulacrum may only be evinced in a feigned manner as a (dis)simulacrum. The analysis of imagery from seminal live shows during 2011–2012 shows that Gaga’s presumed monstrosity is more akin to hyperdifferentiation as simultaneous employment of heterogeneous and potentially dissonant inter pares cultural representations. The article concludes with a problematisation of audience effects in the light of Gaga’s adoption of a schematic and post-representationalist strategy in the event of her strategy’s emulation by competitive artists

    TOI 540 b: A Planet Smaller than Earth Orbiting a Nearby Rapidly Rotating Low-mass Star

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    We present the discovery of TOI 540 b, a hot planet slightly smaller than Earth orbiting the low-mass star 2MASS J05051443-4756154. The planet has an orbital period of P = 1.239149 days (±170 ms) and a radius of r = 0.903 ± 0.052R⊕, and is likely terrestrial based on the observed mass-radius distribution of small exoplanets at similar insolations. The star is 14.008 pc away and we estimate its mass and radius to be M = 0.159 ± 0.014 M⊙ and R = 0.1895 ± 0.0079R⊙, respectively. The star is distinctive in its very short rotational period of Prot = 17.4264 ± 0.0094 hr and correspondingly small Rossby number of 0.007 as well as its high X-ray-to-bolometric luminosity ratio of LX/LboI = 0.0028 based on a serendipitous XMM-Newton detection during a slew operation. This is consistent with the X-ray emission being observed at a maximum value of as predicted for the most rapidly rotating M dwarfs. TOI 540 b may be an alluring target to study atmospheric erosion due to the strong stellar X-ray emission. It is also among the most accessible targets for transmission and emission spectroscopy and eclipse photometry with the James Webb Space Telescope, and may permit Doppler tomography with high-resolution spectroscopy during transit. This discovery is based on precise photometric data from the Transiting Exoplanet Survey Satellite and ground-based follow-up observations by the MEarth team

    Modelling vehicles acceleration during overtaking manoeuvres

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    [EN] Abstract: Overtaking manoeuvre is a key issue for two-lane rural roads. These roads should provide sufficient overtaking sight distance (OSD) at certain locations to allow faster vehicles to pass slower ones. However, overtaking requires occupying the opposing lane, which represents a serious safety concern. Severity of overtaking related crashes is very high, compared with other manoeuvres. The development of advanced driver assistance systems (ADAS) for overtaking is being a complex task. Only few systems have been developed, but are not still in use. This research incorporated accurate data of real manoeuvres to improve the knowledge of the phenomenon. The trajectory of the overtaking vehicles on the left lane was observed. An instrumented vehicle measured the overtaking time and distance, the abreast position, and the initial and final speed of 180 drivers that passed it during a field experiment. Six different kinematic models (such as uniform acceleration or linear variation of acceleration) were calibrated. Generally, drivers started to accelerate before changing to the opposing lane. These models may be applied to ADAS, to estimate OSD and to improve microsimulation models.Part of this research was included in the project 'Desarrollo de modelos de distancias de visibilidad de adelantamiento', with reference code TRA2010-21736 and subsidised by the Spanish Ministery of Economy and Competitivity. The authors also thank Prof Dr Sayed, from University of British Columbia, for his valuable review.Llorca Garcia, C.; Moreno, AT.; García García, A. (2016). Modelling vehicles acceleration during overtaking manoeuvres. IET Intelligent Transport Systems. 10(3):206-215. https://doi.org/10.1049/iet-its.2015.0035S206215103Gray, R., & Regan, D. M. (2005). Perceptual Processes Used by Drivers During Overtaking in a Driving Simulator. 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Transportation Research Part C: Emerging Technologies, 17(6), 617-630. doi:10.1016/j.trc.2009.04.010Milanés, V., Llorca, D. F., Villagrá, J., Pérez, J., Fernández, C., Parra, I., … Sotelo, M. A. (2012). Intelligent automatic overtaking system using vision for vehicle detection. Expert Systems with Applications, 39(3), 3362-3373. doi:10.1016/j.eswa.2011.09.024Isermann, R., Mannale, R., & Schmitt, K. (2012). Collision-avoidance systems PRORETA: Situation analysis and intervention control. Control Engineering Practice, 20(11), 1236-1246. doi:10.1016/j.conengprac.2012.06.003Petrov, P., & Nashashibi, F. (2014). Modeling and Nonlinear Adaptive Control for Autonomous Vehicle Overtaking. IEEE Transactions on Intelligent Transportation Systems, 15(4), 1643-1656. doi:10.1109/tits.2014.2303995Llorca, C., & García, A. (2011). Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data. Transportation Research Record: Journal of the Transportation Research Board, 2262(1), 42-51. doi:10.3141/2262-05Llorca, C., Moreno, A. T., García, A., & Pérez-Zuriaga, A. M. (2013). Daytime and Nighttime Passing Maneuvers on a Two-Lane Rural Road in Spain. Transportation Research Record: Journal of the Transportation Research Board, 2358(1), 3-11. doi:10.3141/2358-01Llorca, C., Moreno, A. T., Pérez-Zuriaga, A. M., & García, A. (2013). Influence of age, gender and delay on overtaking dynamics. IET Intelligent Transport Systems, 7(2), 174-181. doi:10.1049/iet-its.2012.0147Khoury, J. E., & Hobeika, A. (2007). Incorporating Uncertainty into the Estimation of the Passing Sight Distance Requirements. Computer-Aided Civil and Infrastructure Engineering, 22(5), 347-357. doi:10.1111/j.1467-8667.2007.00491.xRakha, H., Snare, M., & Dion, F. (2004). Vehicle Dynamics Model for Estimating Maximum Light-Duty Vehicle Acceleration Levels. 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