857 research outputs found
OS RELEVOS CALCÁRIOS DA REGIÃO CENTRAL DO BARROCAL ALGARVIO (SUL DE PORTUGAL) - UM MODELO TECTÓNICO The limestones reliefs of the Algarve Barrocal (south Portugal) – a tectonic model
Several Mesozoic limestone elevations of E-W elongated shape rise up in the central region of the Algarve Barrocal (Portuguese southwestern margin). Tectonic geomorphology suggests that these reliefs correspond to right lateral strike-slip contractional duplexes of a large, NW-SE trending, shear zone, with a pronounced topographic expression, whose southern boundary, located southeast of the Serra de Monchique hill, is defined by the São Marcos–Quarteira Fault Zone
CONTRIBUIÇÕES DA GEOMORFOLOGIA COSTEIRA AOS ESTUDOS SOBRE PELLETS DE PLÁSTICO EM PRAIAS DE SP, BRASIL
Avanços científicos produziram divisões nas Ciências e suas disciplinas, resultando, a exemplo da Geomorfologia, em diversos campos de análise. As interações com o meio e a produção do espaço pelo homem motivaram novas questões voltadas à compreensão da dinâmica do espaço geográfico. Por esta razão, o presente trabalho objetiva elucidar algumas constatações decorrentes da correlação entre um tema ambiental emergente como os pellets de plástico (microlixo marinho) e a Geomorfologia Costeira
Derek Denny-brown: O Homem Por Detrás Dos Gânglios
The authors present an historical review about the main contributions of Professor Derek Denny-Brown to neurology. Some of his achievements include the first description of sensory neuronopathies, and some of the essential textbooks on the function and anatomy of the basal ganglia. In 2016, on the 35th anniversary of his death, modern neurologists are still strongly influenced by his legacy. © 2017, Associacao Arquivos de Neuro-Psiquiatria. All rights reserved.75212712
An Opinion Dynamics Model for the Diffusion of Innovations
We study the dynamics of the adoption of new products by agents with
continuous opinions and discrete actions (CODA). The model is such that the
refusal in adopting a new idea or product is increasingly weighted by neighbor
agents as evidence against the product. Under these rules, we study the
distribution of adoption times and the final proportion of adopters in the
population. We compare the cases where initial adopters are clustered to the
case where they are randomly scattered around the social network and
investigate small world effects on the final proportion of adopters. The model
predicts a fat tailed distribution for late adopters which is verified by
empirical data.Comment: 14 pages, 8 figures, revised text, a new section with empirical
evidence has been adde
Non-Stationary Covariance Matrices And Noise
The exact meaning of the noise spectrum of eigenvalues of the covariance
matrix is discussed. In order to better understand the possible phenomena
behind the observed noise, the spectrum of eigenvalues of the covariance matrix
is studied under a model where most of the true eigenvalues are zero and the
parameters are non-stationary. The results are compared with real observation
of Brazilian assets, suggesting that, although the non-stationarity seems to be
an important aspect of the problem, partially explaining some of the
eigenvalues as well as part of the kurtosis of the assets, it can not, by
itself, provide all the corrections needed to make the proposed model fit the
data perfectly.Comment: 11 pages, 3 figures, submitted to Physica
Technical and economic pre-feasibility study for the construction of septic tank-filter-sinkhole with alternative material
Received: February 2nd, 2021 ; Accepted: August 3rd, 2021 ; Published: August 24th, 2021 ; Correspondence: [email protected] study of the different materials used in the construction of septic tanks aims to
facilitate and spread the use of this sewage treatment system in places that are not assisted by
municipal sewage systems and in the rural area, which despite having a smaller number of
inhabitants compared to the urban area This study aims to carry out a technical and economic
evaluation of the concrete and tires using in the construction of septic tanks-filter-sinkhole. The
wastewater treatment systems were built according to the recommendations in NBR 7229/93 and
13969/97. To evaluate the efficiency of each system built, the following parameters were
analyzed: chemical oxygen demand (COD), the potential of hydrogen (pH), alkalinity, acidity,
and temperature. In the economic evaluation, the materials and labor required to install the
systems were considered using the Brazilian cost database (SINAPI), and an economic and
financial feasibility study was carried out. According to the technical and economic analysis of
construction, both systems showed the same technical performance, however, the concrete design
proved to be more advantageous than the tire design, considering the difficulty in acquiring the
tires and the high cost if it is necessary to buy them, in addition to the greater difficulty in handling
and installing the tire system compared to the concrete one
Efeitos imediatos e latentes de tratamentos térmico e químico em sementes de Brachiaria brizantha cultivar Marandu
Palaeontological framework from Pirabas Formation (North Brazil) used as potential model for equatorial carbonate platform
The Pirabas Formation (early to middle Miocene) from the equatorial margin of North Brazil is characterized by a shallow-marine carbonate platform with high fossil diversity and abundant micro- and macrofossil remains. The Pirabas Formation represents a unique carbonate system along the Atlantic margin of South America that developed before the onset of the Amazon delta. We studied the palaeontology and lithofacies of outcrops of the uppermost Pirabas Formation and found that was deposited in a coastal marine environment with marginal lagoons under the influence of a tidal regime and tropical storms. The remains of calcareous algae, molluscs, crustaceans, echinoiderms, bryozoans, solitary corals, fish and marine mammals, together with foraminifera, ostracods and other marine microfossils, shaped a biogenic framework, that together with the post-depositional processes of dissolution of skeletal grains, is responsible for the mean packstone-floatstone porosity of 14.9%. The palaeontological framework and the petrophysical characterization of the carbonate rocks from the uppermost Pirabas Formation outcrop represent a baseline to interpret the entire Pirabas Formation in the subsurface stratigraphic sections (cores) of this important Neogene unit. Considering that carbonate rocks account for ~50% of oil and gas reservoirs around the world, this research provides a model for Neogene tropical carbonate deposits useful for carbonate petroliferous reservoirs in the Brazilian equatorial basins.publishe
Importance of anatomical leaf features for characterization of three species of Mapania (Mapanioideae, Cyperaceae) from the Amazon Forest, Brazil
Silicon location through backscattered electron imaging and X-ray microanalysis in leaves of Cyperus ligularis L. and Rhynchospora aberrans C. B. Clarke (Cyperaceae)
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