4,892 research outputs found
The Hidden Beginnings of a Breakthrough: Lina Bo Bardiâs First Steps in Brazil
Italian-born architect Lina Bo Bardi always claimed that she had moved to Brazil in the aftermath of World War II because the freedom ideas of the Italian Resistance had been betrayed. Recent studies argue she was merely accompanying her husband, Pietro Maria Bardi, who was organizing art exhibitions in Rio de Janeiro. However, as documented by the correspondence published here for the first time, Bo Bardi did not embark on the journey to the New World because of the failures of the Italian Resistance or simply as a companion to her husband: she had been charged with the task of ensuring Brazilâs participation in the eighth edition of the Triennale di Milano (1947). On the basis of the correspondence documenting this assignment, this essay fills a historiographic gap and, more importantly, aims to radically revise the narrative around the initial phase of Bo Bardiâsstay in Brazil, the country she increasingly felt asher own and where she eventually spent her en-tire life
Accuracy Improvement of Real-Time Load-Pull Measurements
This paper describes a new procedure aimed to improve the effectiveness of real-time load-pull calibration. Loadpull measurement accuracy is strongly affected by calibration residual uncertainty. The novel methodology reduces this uncertainty contribution by means of error terms optimization. The proposed method has been tested with simulations and applied to actual measurement data. Considerable improvements have been achieve
Pairing fluctuation effects on the single-particle spectra for the superconducting state
Single-particle spectra are calculated in the superconducting state for a
fermionic system with an attractive interaction, as functions of temperature
and coupling strength from weak to strong. The fermionic system is described by
a single-particle self-energy that includes pairing-fluctuation effects in the
superconducting state. The theory reduces to the ordinary BCS approximation in
weak coupling and to the Bogoliubov approximation for the composite bosons in
strong coupling. Several features of the single-particle spectral function are
shown to compare favorably with experimental data for cuprate superconductors.Comment: 4 pages, 4 figure
On the algebraic structure of rotationally invariant two-dimensional Hamiltonians on the noncommutative phase space
We study two-dimensional Hamiltonians in phase space with noncommutativity
both in coordinates and momenta. We consider the generator of rotations on the
noncommutative plane and the Lie algebra generated by Hermitian rotationally
invariant quadratic forms of noncommutative dynamical variables. We show that
two quantum phases are possible, characterized by the Lie algebras
or according to the relation between the
noncommutativity parameters, with the rotation generator related with the
Casimir operator. From this algebraic perspective, we analyze the spectrum of
some simple models with nonrelativistic rotationally invariant Hamiltonians in
this noncommutative phase space, as the isotropic harmonic oscillator, the
Landau problem and the cylindrical well potential.
PACS: 03.65.-w; 03.65.Fd
MSC: 81R05; 20C35; 22E70Comment: 49 pages. No figures. Version to appear in JP
Constraints on Cosmology and Gravity from the Dynamics of Voids
The Universe is mostly composed of large and relatively empty domains known
as cosmic voids, whereas its matter content is predominantly distributed along
their boundaries. The remaining material inside them, either dark or luminous
matter, is attracted to these boundaries and causes voids to expand faster and
to grow emptier over time. Using the distribution of galaxies centered on voids
identified in the Sloan Digital Sky Survey and adopting minimal assumptions on
the statistical motion of these galaxies, we constrain the average matter
content in the Universe today, as well as the
linear growth rate of structure at median redshift
, where is the galaxy bias ( C.L.). These values
originate from a percent-level measurement of the anisotropic distortion in the
void-galaxy cross-correlation function, , and are
robust to consistency tests with bootstraps of the data and simulated mock
catalogs within an additional systematic uncertainty of half that size. They
surpass (and are complementary to) existing constraints by unlocking
cosmological information on smaller scales through an accurate model of
nonlinear clustering and dynamics in void environments. As such, our analysis
furnishes a powerful probe of deviations from Einstein's general relativity in
the low-density regime which has largely remained untested so far. We find no
evidence for such deviations in the data at hand.Comment: 11 pages, 7 figures. Reflects published version in PRL including
Supplemental Materia
Co-constructing a new framework for evaluating social innovation in marginalized rural areas
The EU funded H2020 project \u2018Social Innovation in Marginalised Rural Areas\u2019 (SIMRA; www.simra-h2020.eu) has the overall objective of advancing the state-of-the-art in social innovation. This paper outlines the process for co- developing an evaluation framework with stakeholders, drawn from across Europe and the Mediterranean area, in the fields of agriculture, forestry and rural development. Preliminary results show the importance of integrating process and outcome-oriented evaluations, and implementing participatory approaches in evaluation practice. They also raise critical issues related to the comparability of primary data in diverse regional contexts and highlight the need for mixed methods approaches in evaluation
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