10,818 research outputs found

    Symmetry violations at BABAR

    Get PDF
    Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd.2014 J. Phys.: Conf. Ser. 556 012042 (http://iopscience.iop.org/1742-6596/556/1/012042

    A survey of electric and hybrid vehicle simulation programs

    Get PDF
    Results of a survey conducted within the United States to determine the extent of development and capabilities of automotive performance simulation programs suitable for electric and hybrid vehicle studies are summarized. Altogether, 111 programs were identified as being in a usable state. The complexity of the existing programs spans a range from a page of simple desktop calculator instructions to 300,000 lines of a high-level programming language. The capability to simulate electric vehicles was most common, heat-engines second, and hybrid vehicles least common. Batch-operated programs are slightly more common than interactive ones, and one-third can be operated in either mode. The most commonly used language was FORTRAN, the language typically used by engineers. The higher-level simulation languages (e.g. SIMSCRIPT, GPSS, SIMULA) used by "model builders" were conspicuously lacking

    A survey of electric and hybrid vehicle simulation programs, volume 1

    Get PDF
    Development and capabilities of automotive performance simulation programs suitable for electric and hybrid vehicle studies are considered

    Exchange Rate Regimes and Revenue Performance in Sub-Saharan Africa

    Get PDF
    It has been argued that the institutions of the CFA Franc zone may have reduced inflation but that they also induced misalignment of the real exchange rate and that this is the explanation for their dismal revenue performance. This paper uses a panel of 22 countries in sub-Saharan Africa to estimate revenue performance over the period from 1980 to 1996. It finds that the poor cumulative relative revenue performance of the franc zone countries is mainly attributable to differences in environmental and structural factors, and to their different responses to changes in the equilibrium real exchange rate, but that the misalignment of the real exchange rate also played a part.

    Cellular mechanisms underlying burst firing in substantia nigra dopamine neurons

    Get PDF
    Burst firing of substantia nigra dopamine (SN DA) neurons is believed to represent an important teaching signal that instructs synaptic plasticity and associative learning. However, the mechanisms through which synaptic excitation overcomes the limiting effects of somatic Ca2+-dependent K+ current to generate burst firing are controversial. Modeling studies suggest that synaptic excitation sufficiently amplifies oscillatory dendritic Ca2+ and Na+ channel currents to lead to the initiation of high-frequency firing in SN DA neuron dendrites. To test this model, visually guided compartment-specific patch-clamp recording and ion channel manipulation were applied to rodent SN DA neurons in vitro. As suggested previously, the axon of SN DA neurons was typically found to originate from a large-diameter dendrite that was proximal to the soma. However, in contrast to the predictions of the model, (1) somatic current injection generated firing that was similar in frequency and form to burst firing in vivo, (2) the efficacy of glutamatergic excitation was inversely related to the distance of excitation from the axon, (3) pharmacological blockade or genetic deletion of Ca2+ channels did not prevent high-frequency firing, (4) action potential bursts were invariably detected first at sites that were proximal to the axon, and (5) pharmacological blockade of Na+ channels in the vicinity of the axon/soma but not dendritic excitation impaired burst firing. Together, these data suggest that SN DA neurons integrate their synaptic input in a more conventional manner than was hypothesized previously

    Asynchronous response of coupled pacemaker neurons

    Full text link
    We study a network model of two conductance-based pacemaker neurons of differing natural frequency, coupled with either mutual excitation or inhibition, and receiving shared random inhibitory synaptic input. The networks may phase-lock spike-to-spike for strong mutual coupling. But the shared input can desynchronize the locked spike-pairs by selectively eliminating the lagging spike or modulating its timing with respect to the leading spike depending on their separation time window. Such loss of synchrony is also found in a large network of sparsely coupled heterogeneous spiking neurons receiving shared input.Comment: 11 pages, 4 figures. To appear in Phys. Rev. Let

    A decade of ejecta dust formation in the Type IIn SN 2005ip

    Get PDF
    In order to understand the contribution of core-collapse supernovae to the dust budget of the early universe, it is important to understand not only the mass of dust that can form in core-collapse supernovae but also the location and rate of dust formation. SN 2005ip is of particular interest since dust has been inferred to have formed in both the ejecta and the post-shock region behind the radiative reverse shock. We have collated eight optical archival spectra that span the lifetime of SN 2005ip and we additionally present a new X-shooter optical-near-IR spectrum of SN 2005ip at 4075d post-discovery. Using the Monte Carlo line transfer code DAMOCLES, we have modelled the blueshifted broad and intermediate width Hα\alpha, Hβ\beta and He I lines from 48d to 4075d post-discovery using an ejecta dust model. We find that dust in the ejecta can account for the asymmetries observed in the broad and intermediate width Hα\alpha, Hβ\beta and He I line profiles at all epochs and that it is not necessary to invoke post-shock dust formation to explain the blueshifting observed in the intermediate width post-shock lines. Using a Bayesian approach, we have determined the evolution of the ejecta dust mass in SN 2005ip over 10 years presuming an ejecta dust model, with an increasing dust mass from ~108^{-8} M_{\odot} at 48d to a current dust mass of \sim0.1 M_{\odot}.Comment: Accepted by MNRAS, 17 pages, 11 figures. Author accepted manuscript. Accepted on 04/03/19. Deposited on 07/03/1
    corecore