741 research outputs found
Nominal C-Unification
Nominal unification is an extension of first-order unification that takes
into account the \alpha-equivalence relation generated by binding operators,
following the nominal approach. We propose a sound and complete procedure for
nominal unification with commutative operators, or nominal C-unification for
short, which has been formalised in Coq. The procedure transforms nominal
C-unification problems into simpler (finite families) of fixpoint problems,
whose solutions can be generated by algebraic techniques on combinatorics of
permutations.Comment: Pre-proceedings paper presented at the 27th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur,
Belgium, 10-12 October 2017 (arXiv:1708.07854
Radio interferometry applied to the observation of cosmic-ray induced extensive air showers
We developed a radio interferometric technique for the observation of
extensive air showers initiated by cosmic particles. In this proof-of-principle
study we show that properties of extensive air showers can be derived with high
accuracy in a straightforward manner. Direction reconstruction resolution of and resolution on the depth of shower maximum of \,g/cm are
obtained over the full parameter range studied, with even higher accuracy for
inclined incoming directions. In addition, by applying the developed method to
dense arrays of radio antennas, the energy threshold for the radio detection of
extensive air showers can be significantly lowered. The method can be applied
to several operational experiments and offers good prospects for planned cosmic
particle observatories.Comment: 4 pages, 3 figure
Detection of Exotic Massive Hadrons in Ultra High Energy Cosmic Ray Telescopes
We investigate the detection of exotic massive strongly interacting hadrons
(uhecrons) in ultra high energy cosmic ray telescopes. The conclusion is that
experiments such as the Pierre Auger Observatory have the potential to detect
these particles. It is shown that uhecron showers have clear distinctive
features when compared to proton and nuclear showers. The simulation of uhecron
air showers, and its detection and reconstruction by fluorescence telescopes is
described. We determine basic cuts in observables that will separate uhecrons
from the cosmic ray bulk, assuming this is composed by protons. If these are
composed by heavier nucleus the separation will be much improved. We also
discuss photon induced showers. The complementarity between uhecron detection
in accelerator experiments is discussed.Comment: 9 page 9 figure
RDSim: A fast, accurate and flexible framework for the simulation of the radio emission and detection of downgoing air showers
RDSim is a fast, accurate and flexible framework for the simulation of the
radio emission of downgoing air showers and its detection by an arbitrary
array, including showers initiated by neutrino interactions or tau-lepton
decays. RDSim was build around speed and is based on simple and fast, yet still
accurate, toymodel-like approaches. It models the radio emission using a
superposition emission model that disentangles the Askaryan and geomagnetic
components of the shower radio emission. It uses full ZHAireS simulations as an
input to estimate the electric field at any position on the ground. A single
input simulation can be scaled in energy and rotated in azimuth, taking into
account all relevant effects. This makes it possible to simulate a huge number
of geometries and energies using just a few ZHAireS input simulations. RDSim
takes into account the main characteristics of the detector, such as trigger
setups, thresholds and antenna patterns. To accommodate arrays that use
particle detectors for triggering, such as the Auger RD extension, it also
features a second toymodel to estimate the muon density at ground level and
perform simple particle trigger simulations. Owing to the large statistics made
possible by its speed, it can be used to investigate in detail events with a
very low trigger probability and geometrical effects due to the array layout,
making it specially suited to be used as a fast and accurate aperture
calculator. In case more detailed studies of the radio emission and detector
response are desired, RDSim can also be used to sweep the phase-space for the
efficient creation of dedicated full simulation sets. This is particularly
important in the case of neutrino events, that have extra variables that
greatly impact shower characteristics, such as interaction or decay
depth as well as the type of interaction and it's fluctuations
RDSim, a fast and comprehensive simulation of radio detection of air showers
We present RDSim, a fast and comprehensive framework for the simulation of
the radio emission and detection of downgoing air showers. It can handle any
downgoing shower that can be simulated with ZHAireS including those induced by
CC and NC neutrino interactions and decays. RDSim is based on a
superposition toymodel that disentangles the Askaryan and geomagnetic
components of the shower emission. By using full ZHAireS simulations as input,
it is able to estimate the full radio footprint on the ground. A single input
simulation at a given energy and arrival direction can be scaled in energy and
rotated in azimuth by taking into account all relevant effects. This makes it
possible to simulate a huge number of geometries and energies using just a few
ZHAireS input simulations. The framework takes into account the main
characteristics of the detector, such as trigger setups, thresholds and antenna
patterns. To accommodate arrays that use particle detectors for triggering,
such as the Auger RD extension, it also features a second toymodel to estimate
the muon density at ground level, which is used to perform simple particle
trigger simulations. It's speed makes it possible to investigate in detail
events with a very low trigger probability, as well as many geometrical effects
due to the array layout. In case more detailed studies of the radio detection
are needed, RDSim can also be used to sweep the phase-space for the efficient
creation of dedicated full simulation sets. This is particularly important in
the case of neutrino events, that have extra variables that greatly impact
shower characteristics, such as interaction or decay depth as well as
the type of interaction and it's fluctuations.Comment: arXiv admin note: text overlap with arXiv:2307.0735
Ambientalização curricular na formação de professores de química
Embora o tema da ambientalização curricular (AC) na formação de professores é hoje de interesse nas pesquisas, ainda é pouco abordado nos processos de ensino; por isto, as responsabilidades das universidades, dos programas de formação e dos professores de ciências (química), são fundamentais para atender as problemáticas ambientais e para ter melhores professores que enfrentem este desafio. Assim, a partir de um estudo documental qualitativo feito nos documentos publicados nós últimos dez anos, foram identificadas as tendências da AC no contexto internacional. O estudo faz parte dos antecedentes de uma tese de doutoramento em desenvolvimento na UNESP, SP, Brasil, que busca compreender como melhorar a AC nos programas de formação de professores de química na Colômbia. Os resultados das tendências mostram a AC centrada sobretudo na química verde, articulada ao ensino de química
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