112 research outputs found
Optimising the geospatial configuration of a future lithium ion battery recycling industry in the transition to electric vehicles and a circular economy
Rapid electrification of the transport system will generate substantial volumes of Lithium-ion-battery (LiB) waste as batteries reach their end-of-life. Much attention focuses on the recycling processes, neglecting a broader systemic view that considers the concentration of the costs and impacts associated with logistics and transportation. This paper provides an economic, environmental and geospatial analysis of a future LiB recycling industry in the UK. Hitherto, state-of-the-art assessment methods have evaluated life cycle impacts and costs but have not considered the geographical layer of the problem. This paper develops a GSC derived supply chain model for the UK electric vehicle and end-of-life vehicle battery industry. Considering both pyrometallurgical and hydrometallurgical recycling technologies, the optimisation process takes into account anticipated EV volumes, and, based on anticipated near-term technological evolution of LiBs, the evolution of the mix of battery cathodes in production, and presents a number of scenarios to show where LiB recycling facilities should ideally be geographically located. An economic and environmental assessment based on a customised EverBatt model is provided
How to Make Large Domains of Disoriented Chiral Condensate
Rajagopal and Wilczek have proposed that relativistic nuclear collisions can
generate domains in which the chiral condensate is disoriented. If sufficiently
large ({\it i.e.} nucleus sized), such domains can yield measurable
fluctuations in the number of neutral and charged pions. However, by numerical
simulation of the zero-temperature two-flavor linear sigma model, we find that
domains are essentially {\it pion} sized. Nevertheless, we show that large
domains can occur if the effective mesons masses are much lighter.Comment: 6 pages and 2 postscript figures, BNL-GGP-
Vector Meson Photoproduction from the BFKL Equation II: Phenomenology
Diffractive vector meson photoproduction accompanied by proton dissociation
is studied for large momentum transfer. The process is described by the
non-forward BFKL equation which we use to compare to data collected at the HERA
collider.Comment: 39 pages, 29 figure
Global biogeographic patterns of avian morphological diversity
Understanding the biogeographical patterns, and evolutionary and environmental drivers, underpinning morphological diversity are key for determining its origins and conservation. Using a comprehensive set of continuous morphological traits extracted from museum collections of 8353 bird species, including geometric morphometric beak shape data, we find that avian morphological diversity is unevenly distributed globally, even after controlling for species richness, with exceptionally dense packing of species in hyper-diverse tropical hotspots. At the regional level, these areas also have high morphological variance, with species exhibiting high phenotypic diversity. Evolutionary history likely plays a key role in shaping these patterns, with evolutionarily old species contributing to niche expansion, and young species contributing to niche packing. Taken together, these results imply that the tropics are both âcradlesâ and âmuseumsâ of phenotypic diversity
Reconstruction of the Primordial Power Spectrum by Direct Inversion
We introduce a new method for reconstructing the primordial power spectrum,
, directly from observations of the Cosmic Microwave Background (CMB). We
employ Singular Value Decomposition (SVD) to invert the radiation perturbation
transfer function. The degeneracy of the multipole to wavenumber
linear mapping is thus reduced. This enables the inversion to be carried out at
each point along a Monte Carlo Markov Chain (MCMC) exploration of the combined
and cosmological parameter space. We present best--fit obtained
with this method along with other cosmological parameters.Comment: 23 pages, 9 figure
The critical importance of defined media conditions in Daphnia magna nanotoxicity studies
AbstractDue to the widespread use of silver nanoparticles (AgNPs), the likelihood of them entering the environment has increased and they are known to be potentially toxic. Currently, there is little information on the dynamic changes of AgNPs in ecotoxicity exposure media and how this may affect toxicity. Here, the colloidal stability of three different sizes of citrate-stabilized AgNPs was assessed in standard strength OECD ISO exposure media, and in 2-fold (media2) and 10-fold (media10) dilutions by transmission electron microscopy (TEM) and atomic force microscopy (AFM) and these characteristics were related to their toxicity towards Daphnia magna. Aggregation in undiluted media (media1) was rapid, and after diluting the medium by a factor of 2 or 10, aggregation was reduced, with minimal aggregation over 24h occurring in media10. Acute toxicity measurements were performed using 7nm diameter particles in media1 and media10. In media10 the EC50 of the 7nm particles for D. magna neonates was calculated to be 7.46ÎŒgLâ1 with upper and lower 95% confidence intervals of 6.84ÎŒgLâ1 and 8.13ÎŒgLâ1 respectively. For media1, an EC50 could not be calculated, the lowest observed adverse effect concentration (LOAEC) of 11.25ÎŒgLâ1 indicating a significant reduction in toxicity compared to that in media10. The data suggest the increased dispersion of nanoparticles leads to enhanced toxicity, emphasising the importance of appropriate media composition to fully assess nanoparticle toxicity in aquatic ecotoxicity tests
Resummed event-shape variables in DIS
We complete our study of resummed event-shape distributions in DIS by
presenting results for the class of observables that includes the current jet
mass, the C-parameter and the thrust with respect to the current-hemisphere
thrust axis. We then compare our results to data for all observables for which
data exist, fitting for alpha_s and testing the universality of
non-perturbative 1/Q effects. A number of technical issues arise, including the
extension of the concept of non-globalness to the case of discontinuous
globalness; singularities and non-convergence of distributions other than in
the Born limit; methods to speed up fixed-order Monte Carlo programs by up to
an order of magnitude, relevant when dealing with many x and Q points; and the
estimation of uncertainties on the predictions.Comment: 41 page
Statistical Properties of the Linear Sigma Model
The statistical equilibrium properties of the linear sigma model are studied,
with a view towards characterizing the field configurations employed as initial
conditions for numerical simulations of the formation of disoriented chiral
condensates in high-energy nuclear collisions. The field is decomposed into its
spatial average (the order parameter) and the fluctuations (the quasi-
particles) and enclosed in a rectangular box with periodic boundary conditions.
The quantized quasi-particle modes are described approximately by Klein-Gordon
dispersion relations containing an effective mass that depends on both the
temperature and the magnitude of the order parameter. The thermal fluctuations
are instrumental in shaping the effective potential governing the order
parameter, and the evolution of its statistical distribution with temperature
is discussed, as is the behavior of the associated effective masses. As the
system is cooled the field fluctuations subside, causing a smooth change from
the high-temperature phase in which chiral symmetry is approximately restored
towards the normal phase. Of practical interest is the fact that the
equilibrium field configurations can be sampled in a simple manner, thus
providing a convenient means for specifying the initial conditions in dynamical
simulations of the non-equilibrium relaxation of the chiral field. The
corresponding correlation function is briefly considered and used to calculate
the spectral strength of radiated pions. Finally, by propagating samples of
initial configurations by the exact equation of motion, it has been ascertained
that the treatment is sufficiently accurate to be of practical utility.Comment: 42 pages total, incl 18 figs using pstricks ([email protected]
Evolution of the differential transverse momentum correlation function with centrality in Au+Au collisions at GeV
We present first measurements of the evolution of the differential transverse
momentum correlation function, {\it C}, with collision centrality in Au+Au
interactions at GeV. {\it C} exhibits a strong dependence
on collision centrality that is qualitatively similar to that of number
correlations previously reported. We use the observed longitudinal broadening
of the near-side peak of {\it C} with increasing centrality to estimate the
ratio of the shear viscosity to entropy density, , of the matter formed
in central Au+Au interactions. We obtain an upper limit estimate of
that suggests that the produced medium has a small viscosity per unit entropy.Comment: 7 pages, 4 figures, STAR paper published in Phys. Lett.
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
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