1,499 research outputs found
Recommended from our members
The Evolution of Ethnic Identity From Adolescence to Middle Adulthood: The Case of the Immigrant Second Generation
Through an analysis of qualitative interview and survey data, this study examines ethnic identity development from midadolescence to middle adulthood among a representative sample of immigrants’ children from Mexico, the Philippines, and other countries, who were followed for more than 20 years. Findings reveal that ethnic self-identity labels are more stable in adulthood than adolescence or the transition to adulthood, but the importance of ethnic identity diminishes, especially among those born abroad. Most prefer ethnic identity labels referencing their origin country, reflecting family ties and cultural attachments. However, some, mostly foreign-born, shift to ethnic self-identity labels exclusively related to their American experience, including panethnic labels in response to U.S. racialization. Only a few actively resist such labeling and claim nonhyphenated American identities. Overall, the findings reveal how diverse ethnic identity development patterns over the life course are shaped both by ancestral attachments and the imposition of existing U.S. racial structures
First-principles study of multiferroic RbFe(MoO)
We have investigated the magnetic structure and ferroelectricity in
RbFe(MoO) via first-principles calculations. Phenomenological analyses
have shown that ferroelectricity may arise due to both the triangular chirality
of the magnetic structure, and through coupling between the magnetic helicity
and the ferroaxial structural distortion. Indeed, it was recently proposed that
the structural distortion plays a key role in stabilising the chiral magnetic
structure itself. We have determined the relative contribution of the two
mechanisms via \emph{ab-initio} calculations. Whilst the structural axiality
does induce the magnetic helix by modulating the symmetric exchange
interactions, the electric polarization is largely due to the in-plane spin
triangular chirality, with both electronic and ionic contributions being of
relativistic origin. At the microscopic level, we interpret the polarization as
a secondary steric consequence of the inverse Dzyaloshinskii-Moriya mechanism
and accordingly explain why the ferroaxial component of the electric
polarization must be small
Portuguese adaptation of the academic time management questionnaire : new elements
This paper presents the adaptation of the “Time Management Questionnaire” (TMQ) – drawn up by
Britton and Tesser (1991), the final version of which has become known as the “Academic Time
Management Questionnaire” (ATMQ). The sample comprised 705 Primary School and Secondary
School pupils of both sexes. The factorial analysis of the results followed by varimax rotation led to
three factors that explain 40.06% of the variance; the reliability coefficients were also ascertained. For
the external validity study, the relationship between the ATMQ results and other school variables were
considered, in which significant relations were observed, as expected. The data presented highlights the
qualities of the ATMQ, as well as its usefulness in research. New data confirmed these qualities.info:eu-repo/semantics/publishedVersio
Measuring Active-to-Sterile Neutrino Oscillations with Neutral Current Coherent Neutrino-Nucleus Scattering
Light sterile neutrinos have been introduced as an explanation for a number
of oscillation signals at eV. Neutrino oscillations at
relatively short baselines provide a probe of these possible new states. This
paper describes an accelerator-based experiment using neutral current coherent
neutrino-nucleus scattering to strictly search for active-to-sterile neutrino
oscillations. This experiment could, thus, definitively establish the existence
of sterile neutrinos and provide constraints on their mixing parameters. A
cyclotron-based proton beam can be directed to multiple targets, producing a
low energy pion and muon decay-at-rest neutrino source with variable distance
to a single detector. Two types of detectors are considered: a germanium-based
detector inspired by the CDMS design and a liquid argon detector inspired by
the proposed CLEAR experiment.Comment: 10 pages, 7 figure
Equilibrium properties of the mixed state in superconducting niobium in a transverse magnetic field: Experiment and theoretical model
Equilibrium magnetic properties of the mixed state in type-II superconductors
were measured with high purity bulk and film niobium samples in parallel and
perpendicular magnetic fields using dc magnetometry and scanning Hall-probe
microscopy. Equilibrium magnetization data for the perpendicular geometry were
obtained for the first time. It was found that none of the existing theories is
consistent with these new data. To address this problem, a theoretical model is
developed and experimentally validated. The new model describes the mixed state
in an averaged limit, i.e. %without detailing the samples' magnetic structure
and therefore ignoring interactions between vortices. It is quantitatively
consistent with the data obtained in a perpendicular field and provides new
insights on properties of vortices. % and the entire mixed state. At low values
of the Ginzburg-Landau parameter, the model converts to that of Peierls and
London for the intermediate state in type-I superconductors. It is shown that
description of the vortex matter in superconductors in terms of a 2D gas is
more appropriate than the frequently used crystal- and glass-like scenarios.Comment: 8 pages, 9 figure
GW method with the self-consistent Sternheimer equation
We propose a novel approach to quasiparticle GW calculations which does not
require the computation of unoccupied electronic states. In our approach the
screened Coulomb interaction is evaluated by solving self-consistent
linear-response Sternheimer equations, and the noninteracting Green's function
is evaluated by solving inhomogeneous linear systems. The frequency-dependence
of the screened Coulomb interaction is explicitly taken into account. In order
to avoid the singularities of the screened Coulomb interaction the calculations
are performed along the imaginary axis, and the results are analytically
continued to the real axis through Pade' approximants. As a proof of concept we
implemented the proposed methodology within the empirical pseudopotential
formalism and we validated our implementation using silicon as a test case. We
examine the advantages and limitations of our method and describe promising
future directions.Comment: 18 pages, 6 figure
Intranasal endoscopy diagnosing skull base pathology: A case of clivus chordoma
A técnica endoscópica endonasal, universalmente implementada no diagnóstico e tratamento de múltiplas patologias nasossinusais, surge como uma alternativa válida aos métodos tradicionais de biópsia da base do crânio. De acordo com a literatura disponível, apresenta taxas de sucesso comparáveis ou mesmo superiores às abordagens neurocirúrgicas, com menor morbilidade, desde que efectuada por equipas cirúrgicas experientes e após um estudo pré-operatório cuidadoso. O objectivo deste artigo é a apresentação de um caso clínico de lesão tumoral do clivus, cuja biópsia realizada por via endoscópica demonstrou tratar-se de um cordoma, a mais frequente das neoplasias intrínsecas desta região da base do crânio.info:eu-repo/semantics/publishedVersio
First Astronomical Application of a Cryogenic TES Spectrophotometer
We report on the first astronomical observations with a photon counting pixel
detector that provides arrival time- (delta t = 100ns) and energy- (delta
E_gamma < 0.15eV) resolved measurements from the near IR through the near UV.
Our test observations were performed by coupling this Transition Edge Sensor
(TES) device to a 0.6m telescope; we have obtained the first simultaneous
optical near-IR phase-resolved spectra of the Crab pulsar. A varying infrared
turnover gives evidence of self-absorption in the pulsar plasma. The potential
of such detectors in imaging arrays from a space platform are briefly
described.Comment: 4 pages, 5 figure
- …