18,809 research outputs found
Overlaps after quantum quenches in the sine-Gordon model
We present a numerical computation of overlaps in mass quenches in
sine-Gordon quantum field theory using truncated conformal space approach
(TCSA). To improve the cut-off dependence of the method, we use a novel running
coupling definition which has a general applicability in free boson TCSA. The
numerical results are used to confirm the validity of a previously proposed
analytical Ansatz for the initial state in the sinh-Gordon quench.Comment: 13 pages, 4 pdf figure
Compatibility of alternative fuels with advanced automotive gas turbine and stirling engines. A literature survey
The application of alternative fuels in advanced automotive gas turbine and Stirling engines is discussed on the basis of a literature survey. These alternative engines are briefly described, and the aspects that will influence fuel selection are identified. Fuel properties and combustion properties are discussed, with consideration given to advanced materials and components. Alternative fuels from petroleum, coal, oil shale, alcohol, and hydrogen are discussed, and some background is given about the origin and production of these fuels. Fuel requirements for automotive gas turbine and Stirling engines are developed, and the need for certain reseach efforts is discussed. Future research efforts planned at Lewis are described
Creating temperature dependent Ni-MH battery models for low power mobile devices
In this paper the methodology and the results of creating temperature
dependent battery models for ambient intelligence applications is presented.
First the measurement technology and the model generation process is presented
in details, and then the characteristic features of the models are discussed.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Optimization Aspects of Carcinogenesis
Any process in which competing solutions replicate with errors and numbers of
their copies depend on their respective fitnesses is the evolutionary
optimization process. As during carcinogenesis mutated genomes replicate
according to their respective qualities, carcinogenesis obviously qualifies as
the evolutionary optimization process and conforms to common mathematical
basis. The optimization view accents statistical nature of carcinogenesis
proposing that during it the crucial role is actually played by the allocation
of trials. Optimal allocation of trials requires reliable schemas' fitnesses
estimations which necessitate appropriate, fitness landscape dependent,
statistics of population. In the spirit of the applied conceptual framework,
features which are known to decrease efficiency of any evolutionary
optimization procedure (or inhibit it completely) are anticipated as
"therapies" and reviewed. Strict adherence to the evolutionary optimization
framework leads us to some counterintuitive implications which are, however, in
agreement with recent experimental findings, such as sometimes observed more
aggressive and malignant growth of therapy surviving cancer cells
Major loop reconstruction from switching of individual particles
Major hysteresis loops of groups of isolated 60 mm square garnet particles of a regular
two-dimensional array, have been measured magnetooptically. Individual loops for each particle
were measured, and the statistics of the distribution of coercivities and interaction fields was
determined. It is shown that from the measured coercivity distribution and calculated magnetostatic
interaction fields the major hysteresis loop can be reconstructed. The switching sequence, and the
major loop of an assembly of 535 particles were calculated numerically for two cases: first, when
calculating the magnetostatic interaction, the 25 particles were assumed to be isolated; second, the
major loop of the same 25 particles, embedded into a 939 square, was reconstructed taking into
account the interactions among all 81 particles. The numerically simulated major hysteresis loops
agree very well with the measured loops, demonstrating the reliability of numerical modeling
Weighing the Neutrino
We investigate the potential of short-baseline experiments in order to
measure the dispersion relation of the (muon) neutrino, with a prospect of
eventually measuring the neutrino mass. As a byproduct, the experiment would
help to constrain parameters of Lorentz-violating effects in the neutrino
sector. The potential of a high-flux laser-accelerated proton beam (e.g., at
the upcoming ELI facility), incident on a thick target composed of a light
element to produce pions, with a subsequent decay to muons and muon-neutrinos,
is discussed. We find a possibility for a muon neutrino mass measurement of
unprecedented accuracy.Comment: 12 pages; RevTe
Self-bound Interacting QCD Matter in Compact Stars
The quark gluon plasma (QGP) at zero temperature and high baryon number is a
system that may be present inside compact stars. It is quite possible that this
cold QGP shares some relevant features with the hot QGP observed in heavy ion
collisions, being also a strongly interacting system. In a previous work we
have derived from the QCD Lagrangian an equation of state (EOS) for the cold
QGP, which can be considered an improved version of the MIT bag model EOS.
Compared to the latter, our equation of state reaches higher values of the
pressure at comparable baryon densities. This feature is due to perturbative
corrections and also to non-perturbative effects. Here we apply this EOS to the
study of neutron stars, discussing the absolute stability of quark matter and
computing the mass-radius relation for self-bound (strange) stars. The maximum
masses of the sequences exceed two solar masses, in agreement with the recently
measured values of the mass of the pulsar PSR J1614-2230, and the corresponding
radii around 10-11 km
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