2,966 research outputs found
Configuration of self-organizing informality: socio-spatial dynamic in favelas
This paper aims to discuss on spatial patterns found in favelas throughout di erent cities worldwide, as they seem to reproduce similar con gurations and urban dynamics despite its diverse local contexts. The purpose is to explore these patterns in order to understand its social behaviour and address urban informality issues through it. To see how resilience seems to be inherent to such spaces, that grow vibrant, complex and dynamic global structures emerging and self-organizing from segregation in city space. It pursues the acknowledgement of structural morphological patterns of informality production, those genotypic characteristics that seem to be independent on culture, and might be representative of these social patterns commonly observed worldwide. Favela is observed in this study as a complex, self-organized entity, whose contrast to o cial city relies on its “bottom up” structure. It tends to follow natural rules of organization instead of formal urban strategies. Space Syntax (Hillier and Hanson, 1984) is the theoretical and methodological approach applied, through which it is possible to investigate these peculiar spatial patterns in favela, comparing several cases in Latin America, Africa and Asia. The analyses are based on axial and segment maps. Investigated variables are connectivity, local and global integration, mean depth, synergy, intelligibility, angular Choice, number and length of axes, and number and length of segments, compactness, normalized angular integration and choice for segment comparison. Findings show favela as an entity that maximises use and space into strong fragmented spatial structures, which provides the labyrinthic perception of users, but also accentuates spatial hierarchy. Topography is critical to the understanding of favela’s performance. The more accentuated, the more fragmented, labyrinthic and endogenous. Nevertheless, most analysed favelas locate in at areas and, therefore, present a tendency to better articulate with the surroundings, resulting in a softer in- and-out transition. Such topological performance seems better than Brazilian cities (Medeiros, 2013), which points out favela’s organizing structure as a possible model that could be adopted to re ne the con gurational performance of cities
Extended excitons and compact heliumlike biexcitons in type-II quantum dots.
We have used magneto-photoluminescence measurements to establish that InP/GaAs quantum dots have a type-II band (staggered) alignment. The average excitonic Bohr radius and the binding energy are estimated to be 15 nm and 1.5 meV respectively. When compared to bulk InP, the excitonic binding is weaker due to the repulsive (type-II) potential at the hetero-interface. The measurements are extended to over almost six orders of magnitude of laser excitation powers and to magnetic fields of up to 50 tesla. It is shown that the excitation power can be used to tune the average hole occupancy of the quantum dots, and hence the strength of the electron-hole binding. The diamagnetic shift coe±cient is observed to drastically reduce as the quantum dot ensemble makes a gradual transition from a regime where the emission is from (hydrogen-like) two-particle excitonic states to a regime where the emission from (helium-like) four-particle biexcitonic states also become significant
Sociospatial reading of favela: A comparative analysis from organic Portuguese cities
This research decodifies the favelas spatial system through its configuration in com- parison to historical organic structures aiming at searching similar self-organized processes. It is intended to observe in which way the configuration of such areas, read through their spatial patterns, affects their sociospatial dynamics and how it gets closer to common strategies for organizing the urban space: in which way favela reproduces historically consolidated spatial patterns inherent to organic cities? The Theory of The Social Logic of Space (Hillier & Han- son, 1984) is the theoretical, methodological and technical approach for this study, allowing to investigate such phenomena by means of its spatial complexity. The sample consists of 120 set- tlements around the world, explored according to a set of 26 configurational variables (among qualitative and quantitative, both geometric and topological), compared to a group of 45 Por- tuguese medieval towns (representative of organic cities). Findings show that the favelas recog- nized spatial patterns are mostly common to those associated with organic structures. Despite being much denser and apparently labyrinthine shapes, the internal dynamics of the favelas reveal positive global relationships. These settlements behave similarly to consolidated urban systems and share common spatial logics throughout world regions and distinct cultures, fea- ture which allows recognizing the self-organization strategy as essential to their structural and survival process.info:eu-repo/semantics/publishedVersio
Biosynthesis of Îł-Polyglutamic Acid by Bacillus licheniformis Through Submerged Fermentation (SmF) and Solid-state Fermentation (SSF)
Gamma-Polyglutamic acid (Îł-PGA) was produced from fermentation processes by inoculating the bacterium Bacillus licheniformis on different substrates. In submerged
fermentation (SmF), glycerol and glucose were used as the main carbon substrates while ammonium sulfate served to provide nitrogen. In solid-state fermentation (SSF), soybean was used as the main substrate. Tests carried out in an airlift bioreactor with B. licheniformis showed a maximum productivity of 0.789 g L–1 h–1 and a yield of 0.4 g g–1. Different soybean cultivars from the 2015 and 2016 crops were used in the SSF. The BRS 1001IPRO cultivar, from the 2016 crop, showed the highest production, i.e., 1.2 g L–1 of γ-PGA. This cultivar was subjected to different levels of milling (fine, intermediate and coarse). Coarsely milled grains increased γ-PGA production to 2.7 g L–1. Moreover, coarse milling made the internal nutrients of the grains available for fermentation and this particle size did not compromise aeration during fermentation.
This work is licensed under a Creative Commons Attribution 4.0 International License
Avaliação da biomassa e valor nutricional de pastagem nativa em sistema agroflorestal no semiárido brasileiro.
Adaptação de mapeamento sistemático para levantamento do estado da prática na área de pecuária de precisão.
O objetivo é apresentar uma adaptação do protocolo de mapeamento sistemático para permitir o levantamento do estado da prática quanto a sistemas de software na área de pecuária de precisão
The OSACA Database and a Kinematic Analysis of Stars in the Solar Neighborhood
We transformed radial velocities compiled from more than 1400 published
sources, including the Geneva--Copenhagen survey of the solar neighborhood
(CORAVEL-CfA), into a uniform system based on the radial velocities of 854
standard stars in our list. This enabled us to calculate the average weighted
radial velocities for more than 25~000 HIPPARCOS stars located in the local
Galactic spiral arm (Orion arm) with a median error of +-1 km/s. We use these
radial velocities together with the stars' coordinates, parallaxes, and proper
motions to determine their Galactic coordinates and space velocities. These
quantities, along with other parameters of the stars, are available from the
continuously updated Orion Spiral Arm CAtalogue (OSACA) and the associated
database. We perform a kinematic analysis of the stars by applying an
Ogorodnikov-Milne model to the OSACA data. The kinematics of the nearest single
and multiple main-sequence stars differ substantially. We used distant
(r\approx 0.2 kpc) stars of mixed spectral composition to estimate the angular
velocity of the Galactic rotation -25.7+-1.2 km/s/kpc, and the vertex
deviation,l=13+-2 degrees, and detect a negative K effect. This negative K
effect is most conspicuous in the motion of A0-A5 giants, and is equal to
K=-13.1+-2.0 km/s/kpc.Comment: 16 pages, 8 figure
X-ray Evidence of the Common Envelope Phase of V471 Tauri
Chandra Low Energy Transmission Grating Spectrograph observations of the
pre-cataclysmic binary V471 Tau have been used to estimate the C/N abundance
ratio of the K dwarf component for the first time. While the white dwarf
component dominates the spectrum longward of 50 AA, at shorter wavelengths the
observed X-ray emission is entirely due to coronal emission from the K dwarf.
The H-like resonance lines of C and N yield an estimate of their logarithmic
abundance ratio relative to the Sun of [C/N]=-0.38+/-0.15 - half of the
currently accepted solar value. We interpret this result as the first clear
observational evidence for the presumed common envelope phase of this system,
during which the surface of the K dwarf was contaminated by CN-cycle processed
material dredged up into the red giant envelope. We use the measured C/N ratio
to deduce that 0.015-0.04 Msun was accreted by the K dwarf while engulfed, and
show that this is consistent with a recent tentative detection of 13C in the K
dwarf photosphere, and with the measured Li abundance in the scenario where the
red giant companion was Li-rich during the common envelope phase.Comment: 6 pages, 2 figures, ApJL accepte
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