5,726 research outputs found
Multi-q Pattern Classification of Polarization Curves
Several experimental measurements are expressed in the form of
one-dimensional profiles, for which there is a scarcity of methodologies able
to classify the pertinence of a given result to a specific group. The
polarization curves that evaluate the corrosion kinetics of electrodes in
corrosive media are an application where the behavior is chiefly analyzed from
profiles. Polarization curves are indeed a classic method to determine the
global kinetics of metallic electrodes, but the strong nonlinearity from
different metals and alloys can overlap and the discrimination becomes a
challenging problem. Moreover, even finding a typical curve from replicated
tests requires subjective judgement. In this paper we used the so-called
multi-q approach based on the Tsallis statistics in a classification engine to
separate multiple polarization curve profiles of two stainless steels. We
collected 48 experimental polarization curves in aqueous chloride medium of two
stainless steel types, with different resistance against localized corrosion.
Multi-q pattern analysis was then carried out on a wide potential range, from
cathodic up to anodic regions. An excellent classification rate was obtained,
at a success rate of 90%, 80%, and 83% for low (cathodic), high (anodic), and
both potential ranges, respectively, using only 2% of the original profile
data. These results show the potential of the proposed approach towards
efficient, robust, systematic and automatic classification of highly non-linear
profile curves.Comment: 12 pages, 7 figure
Double particle production in ultraperipheral collisions at the Large Hadron Collider and Future Circular Collider
In this paper we analyze the associated production of a vector meson with a
(pseudo)scalar bound state or a dimuon system in ultraperipheral
collisions through the double scattering mechanism for the energies of the
Large Hadron Collider (LHC) and Future Circular Collider (FCC). Our results
complement previous studies for the double vector meson production. We present
our predictions for the total cross sections and rapidity distributions
considering the rapidity ranges covered by the ALICE and LHCb detectors, which
indicate that a future experimental analysis of the , and final states is feasible.Comment: 6 pages, 2 figures, 1 table. arXiv admin note: text overlap with
arXiv:2210.0486
Associated and photoproduction in ultraperipheral collisions at the Large Hadron Collider and Future Circular Collider
In this paper we analyze the associated and photoproduction
in ultraperipheral collisions through the double scattering mechanism
for the energies of the Large Hadron Collider (LHC) and Future Circular
Collider (FCC). Our results complement a previous analysis for the ,
and production. We present our predictions for
the total cross sections and rapidity distributions considering the rapidity
ranges covered by the ALICE and LHCb detectors, which indicate that a future
experimental analysis of final state is feasible. These results
point out that the study of the double vector meson photoproduction in heavy
ion collisions can be useful to constrain the double scattering mechanism and
improve our understanding of the QCD dynamics at high energies.Comment: 6 pages, 3 figures, 1 tabl
Associated vector meson and bound-free electron-positron pair photoproduction in ultraperipheral collisions
In this letter we analyze the associated production of a vector meson with
the bound - free process in ultraperipheral collisions through
the double scattering mechanism for the energy of the Large Hadron Collider
(LHC). Such process is characterized by the presence of a meson and a positron
in the final state and by a forward hydrogen - like ion with a distinct
electric charge. We present our predictions for the total cross sections and
rapidity distributions considering the rapidity ranges covered by the ALICE and
LHCb detectors, which indicate that a future experimental analysis of the and final states is feasible.Comment: 5 pages, 2 figures, 1 table. arXiv admin note: substantial text
overlap with arXiv:2306.0551
Harnessing ultraconfined graphene plasmons to probe the electrodynamics of superconductors
We show that the Higgs mode of a superconductor, which is usually challenging to observe by far-field optics, can be made clearly visible using near-field optics by harnessing ultraconfined graphene plasmons. As near-field sources we investigate two examples: graphene plasmons and quantum emitters. In both cases the coupling to the Higgs mode is clearly visible. In the case of the graphene plasmons, the coupling is signaled by a clear anticrossing stemming from the interaction of graphene plasmons with the Higgs mode of the superconductor. In the case of the quantum emitters, the Higgs mode is observable through the Purcell effect. When combining the superconductor, graphene, and the quantum emitters, a number of experimental knobs become available for unveiling and studying the electrodynamics of superconductors.- N.M.R.P. acknowledges support from the European Commission through the project "Graphene-Driven Revolutions in Information and Communication Technology (ICT) and Beyond" (881603-Core 3) and the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Financing UID/FIS/04650/2019. N.M.R.P. also acknowledges COMPETE2020, PORTUGAL2020, Fundo Europeu de Desenvolvimento Regional (FEDER), and the Portuguese FCT through Project POCI-01-0145-FEDER-028114. N.A.M. is a VILLUM Investigator supported by VILLUM FONDEN (Grant 16498) and Independent Research Fund Denmark (Grant 7026-00117B). The Center for Nano Optics is financially supported by the University of Southern Denmark (SDU) (SDU 2020 funding). The Center for Nanostructured Graphene is sponsored by the Danish National Research Foundation (Project DNRF103). Work on hybrid heterostructures at Columbia was supported entirely by the Center on Precision-Assembled Quantum Materials, funded through the US National Science Foundation Materials Research Science and Engineering Centers (Award DMR-2011738). D.N.B. is Moore Investigator in Quantum Materials, Emergent Phenomena in Quantum Systems (EPiQS) 9455. D.N.B. is the Vannevar Bush Faculty Fellow ONR-VB: N00014-19-1-2630. F.H.L.K. acknowledges financial support from the Government of Catalonia trough the SGR grant and from the Span-ish Ministry of Economy and Competitiveness (MINECO) through the Severo Ochoa Program for Centers of Excellence in Research & Development (SEV2015-0522); support by Fundacio ' Cellex Barcelona, Generalitat de Catalunya through the Centres de Recerca de Catalunya (CERCA) program; and the MINECO grants Plan Nacional (FIS2016-81044-P) and the Agency for Management of University and Research Grants 2017 SGR 1656. Furthermore, the research leading to these results has received funding from the European Union's Horizon 2020 program under the Graphene Flagship Grants 785219 (Core 2) and 881603 (Core 3) and the Quantum Flagship Grant 820378. This work was also supported b
Efeito da idade de lagartas de Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) no desempenho do parasitoide Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae) e consumo foliar por lagartas parasitadas e não-parasitadas.
Verificou-se o potencial de parasitismo de Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonide) sobre lagartas de Spodoptera frugiperda (Smith) de diferentes idades e o consumo foliar de lagartas parasitadas, em relacao a nao parasitadas. Quando foram oferecidas ao parasitoide lagartas de 3-d o numero medio de lagartas parasitadas foi de 232/femea, numero semelhante ao que foi obtido com lagartas de 2-d (182,0 lagartas/femea). Com lagartas de 4-5-d, o numero medio de parasitismo foi, respectivamente, 80,7 e 71,0 individuos parasitados/femea. Lagarta sadias, durante todo o seu periodo de vida, consumiram, em media, 209,3 cm3 de area foliar, enquanto que as lagartas parasitadas consumiram apenas 14,5 cm3 (6,9% do consumo de uma lagarta sadia)
Adiabatic Invariant Treatment of a Collapsing Sphere of Quantized Dust
The semiclassical collapse of a sphere of quantized dust is studied. A
Born-Oppenheimer decomposition is performed for the wave function of the system
and the semiclassical limit is considered for the gravitational part. The
method of adiabatic invariants for time dependent Hamiltonians is then employed
to find (approximate) solutions to the quantum dust equations of motions. This
allows us to obtain corrections to the adiabatic approximation of the dust
states associated with the time evolution of the metric. The diverse
non-adiabatic corrections are generally associated with particle (dust)
creation and related fluctuations. The back-reaction due to the dominant
contribution to particle creation is estimated and seen to slow-down the
collapse.Comment: LaTeX, 16 pages, no figures, final version to appear in Class. and
Quantum Gravit
Probing the Ionizing Continuum of Narrow-Line Seyfert 1 Galaxies. I.Observational Results
We present optical spectra and emission-line ratios of 12 Narrow-Line Seyfert
1 (NLS1) galaxies that we observed to study the ionizing EUV continuum. A
common feature in the EUV continuum of active galactic nuclei is the big blue
bump (BBB), generally associated with thermal accretion disk emission. While
Galactic absorption prevents direct access to the EUV range, it can be mapped
by measuring the strength of a variety of forbidden optical emission lines that
respond to different EUV continuum regions. We find that narrow emission-line
ratios involving [OII]3727, Hbeta, [OIII]5007, [OI]6300, Halpha,[NII]6583, and
[SII]6716,6731 indicate no significant difference between NLS1s and Broad-Line
Seyfert 1 (BLS1) galaxies, which suggests that the spectral energy
distributions of their ionizing EUV - soft X-ray continua are similar. The
relative strength of important forbidden high ionization lines like [NeV]3426
compared to HeII4686 and the relative strength of [FeX]6374 appear to show the
same range as in BLS1 galaxies. However, a trend of weaker
F([OI]6300)/F(Halpha) emission-line ratios is indicated for NLS1s compared to
BLS1s. To recover the broad emission-line profiles we used Gaussian components.
This approach indicates that the broad Hbeta profile can be well described with
a broad component (FWHM = 3275 +- 800 km/s) and an intermediate broad component
(FWHM = 1200 +- 300 km/s). The width of the broad component is in the typical
range of normal BLS1s. The emission-line flux that is associated with the broad
component in these NLS1s amounts to at least 60% of the total flux. Thus it
dominates the total line flux, similar to BLS1 galaxies.Comment: 34 pages, 9 figures. accepted for publication in the
Astrophys.Journa
Efeito da idade do hospedeiro, Spodoptera frugiperda no desempenho do parasitóide Campoletis flavicincta.
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