6 resultados para Crystal-Growth Process
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
This work presents a reflection on possibilities and boundaries of consolidation and expansion of human settlements characterized as traditional communities that are located within protected areas, using as study reference the State Sustainable Development Reserve Ponta do Tubarão, at Rio Grande do Norte state. The main topics highlight the conflict between the right to housing and the prevalence of fundamental rights of traditional populations, opposed to the diffuse right to environment, according to the regulatory framework of the Brazilian Urban and Environmental Policies. At the same time that these settlements, historically built, are substantiated by the principles of recognition of rights to traditional populations, they are in a condition of complexity to the resolution of conflicts in its urban dimension and lead to an impairment of natural sites. This work questions how the instruments of land use and occupation are defined and relate to environmental planning, especially considering that the settlements are located in Permanent Preservation Areas (APP). It aims to further the discussion of the urban dimension in settlements, characterizing its formation and growth process, to identify the gaps and convergences between the Urban and Environmental Policy, under the foundations of a socio-environmental approach. The results spotlights the conflicts between occupation and natural areas, inferring that the definition of Urban Policies instruments and its integration with Environmental Policies instruments account for essential and priority actions to the achievement to the rights to a sustainable city, as determined in the Cities Statute and environmental protection goals, defined for the Conservation Units
Resumo:
In Natal s urban growth process it is given that the performance period of the National Housing Bank (BNH, 1964-1986) was marked by the intense expansion of the urban grid and configuration of outskirts, through the construction of social housing developments. Implanted in segregated areas of the existing formal city, the population installed in these complexes was also excluded from their rights, considering that the housing defines itself not only by the physical dwelling, but also by its access to urban infrastructure, facilities, services, and others. From this reality and the verification of the city s exclusion and sociospatial segregation processes, we aimed to quantitatively demonstrate levels of social exclusion in Natal, based on the methodology developed by Sposati (2000) and adapted by Genovez (2002), which relates IBGE s (Brazilian Institute of Geography and Statistics) database underlying variables such as income, schooling and dwelling s quality. The research unveiled some spatial patterns promoted by the social housings: in these areas islands were developed with higher indicators than surrounding areas, revealing internal hierarchies in the city s outskirts
Resumo:
This work presents a reflection on possibilities and boundaries of consolidation and expansion of human settlements characterized as traditional communities that are located within protected areas, using as study reference the State Sustainable Development Reserve Ponta do Tubarão, at Rio Grande do Norte state. The main topics highlight the conflict between the right to housing and the prevalence of fundamental rights of traditional populations, opposed to the diffuse right to environment, according to the regulatory framework of the Brazilian Urban and Environmental Policies. At the same time that these settlements, historically built, are substantiated by the principles of recognition of rights to traditional populations, they are in a condition of complexity to the resolution of conflicts in its urban dimension and lead to an impairment of natural sites. This work questions how the instruments of land use and occupation are defined and relate to environmental planning, especially considering that the settlements are located in Permanent Preservation Areas (APP). It aims to further the discussion of the urban dimension in settlements, characterizing its formation and growth process, to identify the gaps and convergences between the Urban and Environmental Policy, under the foundations of a socio-environmental approach. The results spotlights the conflicts between occupation and natural areas, inferring that the definition of Urban Policies instruments and its integration with Environmental Policies instruments account for essential and priority actions to the achievement to the rights to a sustainable city, as determined in the Cities Statute and environmental protection goals, defined for the Conservation Units
Resumo:
In Natal s urban growth process it is given that the performance period of the National Housing Bank (BNH, 1964-1986) was marked by the intense expansion of the urban grid and configuration of outskirts, through the construction of social housing developments. Implanted in segregated areas of the existing formal city, the population installed in these complexes was also excluded from their rights, considering that the housing defines itself not only by the physical dwelling, but also by its access to urban infrastructure, facilities, services, and others. From this reality and the verification of the city s exclusion and sociospatial segregation processes, we aimed to quantitatively demonstrate levels of social exclusion in Natal, based on the methodology developed by Sposati (2000) and adapted by Genovez (2002), which relates IBGE s (Brazilian Institute of Geography and Statistics) database underlying variables such as income, schooling and dwelling s quality. The research unveiled some spatial patterns promoted by the social housings: in these areas islands were developed with higher indicators than surrounding areas, revealing internal hierarchies in the city s outskirts
Resumo:
Titanium nitride films were grown on glass using the Cathodic Cage Plasma Deposition technique in order to verify the influence of process parameters in optical and structural properties of the films. The plasma atmosphere used was a mixture of Ar, N2 and H2, setting the Ar and N2 gas flows at 4 and 3 sccm, respectively and H2 gas flow varied from 0, 1 to 2 sccm. The deposition process was monitored by Optical Emission Spectroscopy (OES) to investigate the influence of the active species in plasma. It was observed that increasing the H2 gas flow into the plasma the luminescent intensities associated to the species changed. In this case, the luminescence of N2 (391,4nm) species was not proportional to the increasing of the H2 gas into the reactor. Other parameters investigated were diameter and number of holes in the cage. The analysis by Grazing Incidence X-Ray Diffraction (GIXRD) confirmed that the obtained films are composed by TiN and they may have variations in the nitrogen amount into the crystal and in the crystallite size. The optical microscopy images provided information about the homogeneity of the films. The atomic force microscopy (AFM) results revealed some microstructural characteristics and surface roughness. The thickness was measured by ellipsometry. The optical properties such as transmittance and reflectance (they were measured by spectrophotometry) are very sensitive to changes in the crystal lattice of the material, chemical composition and film thicknesses. Therefore, such properties are appropriate tools for verification of this process control. In general, films obtained at 0 sccm of H2 gas flow present a higher transmittance. It can be attributed to the smaller crystalline size due to a higher amount of nitrogen in the TiN lattice. The films obtained at 1 and 2 sccm of H2 gas flow have a golden appearance and XRD pattern showed peaks characteristics of TiN with higher intensity and smaller FWHM (Full Width at Half Maximum) parameter. It suggests that the hydrogen presence in the plasma makes the films more stoichiometric and becomes it more crystalline. It was observed that with higher number of holes in the lid of the cage, close to the region between the lid and the sample and the smaller diameter of the hole, the deposited film is thicker, which is justified by the most probability of plasma species reach effectively the sample and it promotes the growth of the film
Resumo:
Thin commercial aluminum electrolytic and passed through reactions was obtained with anodic alumina membranes nanopores. These materials have applications in areas recognized electronic, biomedical, chemical and biological weapons, especially in obtaining nanostructures using these membranes as a substrate or template for processing nanowires, nanodots and nanofibers for applications noble. Previous studies showed that the membranes that have undergone heat treatment temperature to 1300° C underwent changes in morphology, crystal structure and optical properties. This aim, this thesis, a study of the heat treatment of porous anodic alumina membranes, in order to obtain and to characterize the behavior changes structures during the crystallization process of the membranes, at temperatures ranging between 300 and 1700° C. It was therefore necessary to mount a system formed by a tubular furnace resistive alumina tube and controlled environment, applying flux with special blend of Ag-87% and 13% N2, in which argon had the role of carrying out the oxygen nitrogen system and induce the closing of the pores during the densification of the membrane. The duration of heat treatment ranged from 60 to 15 minutes, at temperatures from 300 to 1700° C respectively. With the heat treatment occurred: a drastic reduction of porosity, grain growth and increased translucency of the membrane. For the characterization of the membranes were analyzed properties: Physical - thermogravimetric, X-ray diffraction, BET surface area; morphological - SEM, EDS through compositional and, optical absorbance, and transmittance in the UV-VIS, and FTIR. The results using the SEM showed that crystallization has occurred, densification and significant changes in membrane structure, as well as obtaining microtube, the BET analysis showed a decrease in specific surface area of the membranes has to 44.381 m2.g-1 to less than 1.8 m2.g-1 and in the analysis of transmittance and absorbance was found a value of 16.5% in the range of 800 nm, characteristic of the near infrared and FTIR have confirmed the molecular groups of the material. Thus, one can say that the membranes were mixed characteristics and properties which qualify for use in gas filtration system, as well as applications in the range of optical wavelength of the infra-red, and as a substrate of nanomaterials. This requires the continuation and deepening of additional study