5,542 research outputs found
The political economy of innovation; an institutional analysis of industrial policy and development in Brazil
This dissertation examines Brazilian industrial policies during the administrations of President Lula (2003-2010) and questions if innovation has truly been the main driver of those instruments. It provides a brief overview on the intersections of politics, economics, innovation and institutions as well as the main choices, incentives and alliances of the Brazilian government, which are illustrated by the Innovation Law, PITCE, PDP and campaign financing of President Lula's 2002 and 2006 candidacies. By adding to the analysis Brazil's exports, its balance of trade and the expenditures of BNDES, this research indicates a disconnect between the intentions and the results of the industrial policy. China and “low-tech” businesses seem to have become the real drivers of the government's agenda; the first for its importance to the Brazilian economy and the latter for its influence with government. Finally, while recognizing some positive results, it presents an alternative model based on a “high-tech” natural resources vision of development which could convert the current challenges into opportunitiesBrazil; development; institutions; innovation; industrial policy
Stability windows for proto-quark stars
We investigate the existence of possible stable strange matter and related
stability windows at finite temperature for different models that are generally
applied to describe quark stars, namely, the quark-mass density dependent
model, the MIT bag model and the Nambu-Jona-Lasinio model. We emphasize that,
although the limits for stable strange matter depend on a comparison with the
ground state of 56Fe, which is a zero temperature state, the quantity that has
to be used in the search for strange matter in proto-quark stars is the free
energy and we analyze stability windows up to temperatures of the order of 40
MeV. The effects of strong magnetic fields on stability windows are computed
and the resulting mass-radius relations for different stages of the proto-quark
star are analyzed.Comment: Published versio
NGC 7097: the AGN and its mirror, revealed by PCA Tomography
Three-dimensional (3D) spectroscopy techniques are becoming more and more
popular, producing an increasing number of large data cubes. The challenge of
extracting information from these cubes requires the development of new
techniques for data processing and analysis. We apply the recently developed
technique of Principal Component Analysis (PCA) Tomography to a data cube from
the center of the elliptical galaxy NGC 7097 and show that this technique is
effective in decomposing the data into physically interpretable information. We
find that the first five principal components of our data are associated with
distinct physical characteristics. In particular, we detect a LINER with a weak
broad component in the Balmer lines. Two images of the LINER are present in our
data, one seen through a disk of gas and dust, and the other after scattering
by free electrons and/or dust particles in the ionization cone. Furthermore, we
extract the spectrum of the LINER, decontaminated from stellar and extended
nebular emission, using only the technique of PCA Tomography. We anticipate
that the scattered image has polarized light, due to its scattered nature.Comment: 12 pages, 5 figures, accepted for publication in ApJ Letter
IFU spectroscopy of 10 early type galactic nuclei: II - Nuclear emission line properties
Although it is well known that massive galaxies have central black holes,
most of them accreting at low Eddington ratios, many important questions still
remain open. Among them, are the nature of the ionizing source, the
characteristics and frequencies of the broad line region and of the dusty
torus. We report observations of 10 early-type galactic nuclei, observed with
the IFU/GMOS spectrograph on the Gemini South telescope, analysed with standard
techniques for spectral treatment and compared with results obtained with
principal component analysis Tomography (Paper I). We performed spectral
synthesis of each spaxel of the data cubes and subtracted the stellar component
from the original cube, leaving a data cube with emission lines only. The
emission lines were decomposed in multi-Gaussian components. We show here that,
for eight galaxies previously known to have emission lines, the narrow line
region can be decomposed in two components with distinct line widths. In
addition to this, broad H emission was detected in six galaxies. The
two galaxies not previously known to have emission lines show weak H+[N
II] lines. All 10 galaxies may be classified as low-ionization nuclear emission
regions in diagnostic diagrams and seven of them have bona fide active galactic
nuclei with luminosities between 10 and 10 erg s.
Eddington ratios are always < 10.Comment: 16 pages, 9 figures, accepted for publication in MNRA
Integral field unit spectroscopy of 10 early type galactic nuclei: I - Principal component analysis Tomography and nuclear activity
Most massive galaxies show emission lines that can be characterized as
LINERs. To what extent this emission is related to AGNs or to stellar processes
is still an open question. In this paper, we analysed a sample of such galaxies
to study the central region in terms of nuclear and circumnuclear emission
lines, as well as the stellar component properties. For this reason, we
selected 10 massive ( > 200 km/s) nearby (d < 31 Mpc) galaxies and
observed them with the IFU/GMOS (integral field unit/Gemini Multi-Object
Spectrograph) spectrograph on the Gemini South Telescope. The data were
analysed with principal component analysis (PCA) Tomography to assess the main
properties of the objects. Two spectral regions were analysed: a yellow region
(5100-5800 A), adequate to show the properties of the stellar component, and a
red region (6250-6800 A), adequate to analyse the gaseous component. We found
that all objects previously known to present emission lines have a central
AGN-type emitting source. They also show gaseous and stellar kinematics typical
of discs. Such discs may be co-aligned (NGC 1380 and ESO 208 G-21), in
counter-rotation (IC 1459 and NGC 7097) or misaligned (IC 5181 and NGC 4546).
We also found one object with a gaseous disc but no stellar disc (NGC 2663),
one with a stellar disc but no gaseous disc (NGC 1404), one with neither
stellar nor gaseous disc (NGC 1399) and one with probably ionization cones (NGC
3136). PCA Tomography is an efficient method for detecting both the central AGN
and gaseous and stellar discs. In the two cases (NGC 1399 and NGC 1404) in
which no lines were previously reported, we found no evidence of either nuclear
or circumnuclear emission, using PCA Tomography only.Comment: 26 pages, 17 figures, accepted for publication in MNRA
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