12,155 research outputs found
Kinematics of galaxies from [CII] line emission
We study the kinematical properties of galaxies in the Epoch of Reionization
via the [CII] 158m line emission. The line profile provides information on
the kinematics as well as structural properties such as the presence of a disk
and satellites. To understand how these properties are encoded in the line
profile, first we develop analytical models from which we identify disk
inclination and gas turbulent motions as the key parameters affecting the line
profile. To gain further insights, we use "Althaea", a highly-resolved () simulated prototypical Lyman Break Galaxy, in the redshift range , when the galaxy is in a very active assembling phase. Based on
morphology, we select three main dynamical stages: I) Merger , II) Spiral Disk,
and III) Disturbed Disk. We identify spectral signatures of merger events,
spiral arms, and extra-planar flows in I), II), and III), respectively. We
derive a generalised dynamical mass vs. [CII]-line FWHM relation. If precise
information on the galaxy inclination is (not) available, the returned mass
estimate is accurate within a factor (). A Tully-Fisher relation is
found for the observed high- galaxies, i.e. for which we provide a simple, physically-based
interpretation. Finally, we perform mock ALMA simulations to check the
detectability of [CII]. When seen face-on, Althaea is always detected at ; in the edge-on case it remains undetected because the larger
intrinsic FWHM pushes the line peak flux below detection limit. This suggests
that some of the reported non-detections might be due to inclination effects.Comment: 14 pages, 12 figures, accepted for publication in MNRA
Probing Low Energy Neutrino Backgrounds with Neutrino Capture on Beta Decaying Nuclei
We study the interaction of low energy neutrinos on nuclei that spontaneously
undergo beta decay showing that the product of the cross section times neutrino
velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that
decay via allowed transitions. The absence of energy threshold and the value of
the cross section single out these processes as a promising though very
demanding approach for future experiments aimed at a direct detection of low
energy neutrino backgrounds such as the cosmological relic neutrinos.Comment: Includes a discussion of local relic neutrino density effect on
neutrino capture rate. Accepted for publication in JCA
Deep into the structure of the first galaxies: SERRA views
We study the formation and evolution of a sample of Lyman Break Galaxies in
the Epoch of Reionization by using high-resolution (),
cosmological zoom-in simulations part of the SERRA suite. In SERRA, we follow
the interstellar medium (ISM) thermo-chemical non-equilibrium evolution, and
perform on-the-fly radiative transfer of the interstellar radiation field
(ISRF). The simulation outputs are post-processed to compute the emission of
far infrared lines ([CII], [NII], and [OIII]). At , the most massive
galaxy, `Freesia', has an age , stellar mass
, and a star formation rate
, due to a recent burst.
Freesia has two stellar components (A and B) separated by ; other 11 galaxies are found within . The
mean ISRF in the Habing band is and is spatially uniform; in
contrast, the ionisation parameter is , and
has a patchy distribution peaked at the location of star-forming sites. The
resulting ionising escape fraction from Freesia is .
While [CII] emission is extended (radius 1.54 kpc), [OIII] is concentrated in
Freesia-A (0.85 kpc), where the ratio . As many high- galaxies, Freesia lies below the local [CII]-SFR
relation. We show that this is the general consequence of a starburst phase
(pushing the galaxy above the Kennicutt-Schmidt relation) which
disrupts/photodissociates the emitting molecular clouds around star-forming
sites. Metallicity has a sub-dominant impact on the amplitude of [CII]-SFR
deviations.Comment: 22 pages, 14 figures, accepted by MNRA
Systems for Conflict Resolution in Comparative Perspective
A cornerstone of industrial relations theory is the idea that the potential for conflict is inherent in the employment relationship. Across countries, forms of workplace conflict and methods of conflict resolution take a range of different forms. Yet aside from attempts to understand cross-national variation in strikes, little research has examined systemic differences in the manifestation and management of workplace conflict. The authors seek to fill this void by analyzing through a comparative lens practices for addressing employment-related conflict in four countries: Germany, the United States, Italy, and Australia. In contrast to the unidimensional varieties of capitalism approach, they analyze workplace conflict resolution systems across two dimensions: collective-individual and regulated-voluntarist. The analysis also emphasizes the importance of within-country variation and interactions between different conflict resolution subsystems
PRIMARY SCHOOL TEACHER TRAINING IN BRAZIL: A PROPOSAL WHICH CONTEMPLATES THE PARADIGM OF COMPLEXITY IN THE TRANSDISCIPLINARY VISION
This article originates from part of a research, with a focus on the issue: How to offer a proper in-service continuous training programme which contemplates the Paradigm of Complexity, catering for a transdisciplinary vision, in the search of the (re)construction and consolidation of the pedagogical knowledge of teachers who work with early childhood education? This research, of a descriptive nature, is linked to the group called PEFOP - Paradigmas Educacionais Formação de Professores, allocated to the stricto sensu Graduate Programme in Education, at Pontifícia Universidade Católica do Paraná-Brazil. The research as a whole aims to investigate the point of view of teachers who work with early childhood education, proposing the curricular extension in regards to teacher training, emphasizing the importance of the complexity vision in the pedagogical practice. It proposes the investigation of different professional training possibilities of this level of education, taking into account the necessity of a pragmatic change to teaching practice. In this article which was consolidated while the researcher sought to understand the components that make up the change of early childhood education professionals. The investigation allowed us to realize that the professionals who work with this level of education can enhance their teaching practice, having as basis the transdisciplinary vision, focusing on the paradigmatic change of the Complexity. This, as a comprehensive theoretical-practical basis, allows a methodological unleashing able to build substrates to go beyond the content included in the curriculum, in search of learning which is really significant to the lives of the students
PRIMARY SCHOOL TEACHER TRAINING IN BRAZIL: A PROPOSAL WHICH CONTEMPLATES THE PARADIGM OF COMPLEXITY IN THE TRANSDISCIPLINARY VISION
This article originates from part of a research, with a focus on the issue: How to offer a proper in-service continuous training programme which contemplates the Paradigm of Complexity, catering for a transdisciplinary vision, in the search of the (re)construction and consolidation of the pedagogical knowledge of teachers who work with early childhood education? This research, of a descriptive nature, is linked to the group called PEFOP - Paradigmas Educacionais Formação de Professores, allocated to the stricto sensu Graduate Programme in Education, at Pontifícia Universidade Católica do Paraná-Brazil. The research as a whole aims to investigate the point of view of teachers who work with early childhood education, proposing the curricular extension in regards to teacher training, emphasizing the importance of the complexity vision in the pedagogical practice. It proposes the investigation of different professional training possibilities of this level of education, taking into account the necessity of a pragmatic change to teaching practice. In this article which was consolidated while the researcher sought to understand the components that make up the change of early childhood education professionals. The investigation allowed us to realize that the professionals who work with this level of education can enhance their teaching practice, having as basis the transdisciplinary vision, focusing on the paradigmatic change of the Complexity. This, as a comprehensive theoretical-practical basis, allows a methodological unleashing able to build substrates to go beyond the content included in the curriculum, in search of learning which is really significant to the lives of the students
Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior
The KamLAND and Borexino experiments have detected electron antineutrinos
produced in the decay chains of natural thorium and uranium (Th and U
geoneutrinos). We analyze the energy spectra of current geoneutrino data in
combination with solar and long-baseline reactor neutrino data, with
marginalized three-neutrino oscillation parameters. We consider the case with
unconstrained Th and U event rates in KamLAND and Borexino, as well as cases
with fewer degrees of freedom, as obtained by successively assuming for both
experiments a common Th/U ratio, a common scaling of Th+U event rates, and a
chondritic Th/U value. In combination, KamLAND and Borexino can reject the null
hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or
indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in
broad agreement with typical Earth model expectations. Conversely, the results
disfavor the hypothesis of a georeactor in the Earth's core, if its power
exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is
highlighted.Comment: 12 pages, including 6 figure
Particle size effect in methane activation over supported palladium nanoparticles
A synthesis method for producing MgAl oxide supported uniform palladium nanoparticles with varying diameters has been developed. The method consists of reductive-thermal decomposition of a PdMgAl hydrotalcite-like compound, formed via co-precipitation of metal nitrate salts and sodium carbonate. The hydrotalcite–like precursors were characterized by XRD, TG-MS and SEM, and were found to contain a well-defined crystalline structure and a uniform distribution of all constituent elements. The resulting catalysts were characterized by XRD, TEM, Chemisorption of CO and in situ IR measurements of CO, and were found to consist of partially oxide-embedded Pd nanoparticles with diameters ranging from d = 1.7 to 3.3 nm and correspond dispersions of 67–14%. Furthermore, the particle size was found to be inversely related to Pd loading. The palladium catalysts were studied for methane activation via chemisorption at 200 and 400 °C followed by a temperature programmed surface hydrogenation. The most disperse catalyst (d = 1.7 nm) possessed an intrinsic methane adsorption capacity, which was an order of magnitude larger than that of other catalysts in the series, indicating a strong structure sensitivity in this reaction. Additionally, the methane adsorption capacity of the hydrotalcite-derived Pd catalysts was nearly two orders of magnitude higher than that of catalysts derived through other synthesis pathways such as colloidal deposition or sonochemical reduction
-Decay Spectrum, Response Function and Statistical Model for Neutrino Mass Measurements with the KATRIN Experiment
The objective of the Karlsruhe Tritium Neutrino (KATRIN) experiment is to
determine the effective electron neutrino mass with an
unprecedented sensitivity of (90\% C.L.) by precision electron
spectroscopy close to the endpoint of the decay of tritium. We present
a consistent theoretical description of the electron energy spectrum in
the endpoint region, an accurate model of the apparatus response function, and
the statistical approaches suited to interpret and analyze tritium
decay data observed with KATRIN with the envisaged precision. In addition to
providing detailed analytical expressions for all formulae used in the
presented model framework with the necessary detail of derivation, we discuss
and quantify the impact of theoretical and experimental corrections on the
measured . Finally, we outline the statistical methods for
parameter inference and the construction of confidence intervals that are
appropriate for a neutrino mass measurement with KATRIN. In this context, we
briefly discuss the choice of the energy analysis interval and the
distribution of measuring time within that range.Comment: 27 pages, 22 figures, 2 table
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