931 resultados para Sub-Artic


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The aim of this study was to evaluate whether digitized images obtained from periapical radiographs taken with low dose of radiation could be improved with the aid of a computer software (PhotoStyler) for digital treatrnent. Serial and standardized radiographs of molar and premolar areas were studied. A total of 57 images equivalent to the radiographs taken with reduced exposure time ( 60 and 80% of the time considered normal), digitized and treated, were submitted to the evaluation of seven exanúners which compared them with those images without treatment. lt was verified that about 80% of the images equivalem to lhe radiographs taken with 60% reduction of ordinary exposure time were considered to having quality for supporting diagnosis. As for the images taken with 80% reduction of ordinary exposure time, about 50% of them were considered suitable for the sarne purpose

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Metal oxide nanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first process produces directly a two-phase material, while the sol-gel powder never showed second phase below 600°C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.

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Semiconductor-mediated photocatalytic oxidation is an interesting method for water decontamination and a specially modified TiO2 is said to be a promising material. This study verified that the synthesis of 1wt%Ag modified-Sc0.01Ti0.99O1.995 powder samples prepared by Polymeric Precursor Method is capable of forming a mixture of anatase-rutile phase with high photocatalytic performance. This kind of material is found to have a lower bandgap compared to the TiO2-anatase commercial powders, which can be associated to an innovative hybrid modification. The simultaneous insertion of scandium in order to generate a p-type semiconductor and a metallic silver nanophase acting as an electron trapper demonstrated being capable of enhancing the degradation of rhodamine B compared to the commercial TiO2. In spite of the different thermal treatments or phase amounts, the hybrid modified powder samples showed higher photocatalytic activity than the commercial ones.

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Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 °C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Watersheds are considered important study units when it comes to environmental planning, with regard to the optimal use of water resources. Water scarcity is predicted and feared by many societies, and proves to be an increasingly tangible problem nowadays. Still from the perspective of extreme events, this dissertation considers the study of flood waves in the sub-basin of the stream Claro, which belongs to the Corumbataí watershed. - SP, since thay can also have devastating effects for the population, A Decision Support System for Flood Routing Analysis in Complex Basins, ABC 6 software was applied in order to obtain hydrographs and peak flows in the sub-basin of the stream Claro, for return periods of 10 and 100 years, aiming to comprise events of different magnitudes. The model Soil Conservation Service (SCS) and the triangular SCS hydrograph were adopted for the simulations. Simultaneously, the Kokei Uehara method was applied for the obtainment of peak flow values under the same conditions, seeking to compare results. Data collection was performed using geoprocessing tools. For data entry in ABC 6, the fragmentation of sub-basin of the stream Claro was necessary, which generated 7 small watersheds, in order to fulfill a software demand, as the maximum drainage area it accepts is 50km² for each watershed analyzed. For RT = 10 and 100 years, respectively, the results of peak flow with use of ABC 6 were 46.10 and 95.45 m³/s, while for Kokei Uehara method, the results were 47.17 and 65.26 m³/s. The adoption of a single value of discretization time for all watersheds was indicated as limitation of ABC 6, which interfered in the final results. Kokei method Uehara considered the sub-basin of the stream Claro as a whole, which reduced the error accumulation probability

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Many fire occurrences in vegetation happen annually in the city of Rio Claro, causing material losses, environmental damage and discomfort to population. When identified the source, notes that the higher index is intentional, however, climatic factors such as wind speed, temperature, relative air humidity, rainfall, or even the local relief also affects in the spread and its devastating effects. Scientific studies that would assist the local community in the prevention and repression of them still are scarce. This way, the work has as objective contributes in the understanding of the relationship among the fire occurrences in vegetation registered (recorded) by Fire Department of Rio Claro/SP, and their relationships with the atmospheric time. To achieve this goal was made to build a database related to fires in vegetation during the years 2009-2013, and subsequently correlated with data of precipitation and relative humidity the air, provided by Center for Analysis and Planning Environmental (CEAPLA). The result identified the profile of the fires, the seasons of higher frequency, neighborhoods and districts with the highest number of records and correlate events with climatic factors that act in the ignition, propagation and control of fires in the Municipal district of Rio Claro/SP

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Expansion of agricultural practice, cattle raising and forestry, in a disorderly way and no limits of land use, generates the degradation of natural resources such as soil, water and vegetation. That fact brings consequences, impacts the environment and the rural landscape. This study aimed to identify and quantify the land use in nine watersheds included in the watershed of Faxinal creek, located in western Botucatu, São Paulo State, Brazil, at 22º 51’ 35” and 22º 57’ 02” – Latitude S and 48º 39’ 42” and 48º 38’ 01” – Longitude W. The basin was subdivided into 9 subunits, being eight from second and one from third-order branch. The diagnosis of the subunits was carried out with geospatial technologies, in order to gather data on the use and occupation of the soil. Based on the obtained results, was concluded that the sub watersheds are occupied by the sum of areas of Citrus, horticulture, coffee plantation and small other occupations (25,81%), followed by reforestation (24,80%), as an isolated occupation element, has occupied the largest area.

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The land use conservation planning requires knowledge of the soil characteristics, natural susceptibility to erosion and the soil loss limit. In this context, the objectives of this study were to perform a detailed soil survey of Ribeirão das Perobas watershed, located in Santa Cruz do Rio Pardo, São Paulo State and to determine and map the erodibility and soil loss tolerance of the soil classes found in the survey. The following techniques were used to perform the detailed soil survey: photopedology, field sampling, physical analysis, chemical analysis, and morphological description of the soil samples and profiles. The erodibility was determined by the methods described by Denardin (1990) and Mannigel et al. (2002), and the determination of soil loss tolerance followed the methodology of Mannigel et al. (2002). The results of erodibility determined by the methodology of Denardin (1990) were not discrepant and they did not distinguish soils that are known to have different susceptibility to erosion., w\Whereas, using the methodology of Mannigel et al. (2002), very high or very low erodibility values were observed in soils with extreme contents of sand silt or clay. The most influent variable to the soil loss tolerance results was the correction factor for the textural gradient of clay between soil horizons.

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The watershed is considered a unit of territorial study, planning and land management, and is molded by the local geologic conditions and climate. Thus, this study aimed to assess the morphometric features of the subwatershed of Cascata Stream, in Botucatu (SP), and their implications for the siltation process in a lake. The assessment included indexes generated from data calculated by means of a digitalized cartographic basis georeferenced on the 1:10,000 scale using the software AutoCad map 2004. The software Quantum GIS 1.8 was also employed to generate the digital elevation model (DEM) and the map of declivities which led to the mean declivity (Dm) of the subwatershed. According to the indexes form factor (Kf), sinuosity (Is), circularity (Ic) and compacity coefficient (Kc), the subwatershed had elongated form, low propensity to floods and rapid flow. The draining density (Dd) and relief ratio (Rr) indicated more efficient mean drainage, favoring higher desiccation and mean erosive stage. The roughness coefficient (Cr) indicated that this subwatershed is suited to agriculture. The anthropic intervention at the watershed dividing line is the major factor for sediment carrying in the lake and compromises not only the landscape beauty, but also the aquatic life of this ecosystem.

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The study aimed mapping of the land use capacity classes for the Rio das Pedras watershed, Itatinga-SP in order to provide another mechanism of environmental planning for the studied area. It was used 1:10,000 topographic letters for the slope map generation which was overlaid with the studied area soil map. It was applied the judgment table criteria method, for generation of land use capacity map of the studied area. It were identified the following results: First, class III with constraints in relation of low fertility and restrictions about erosion risks on high slope areas. Second, class VI with the same characteristics of class III however with the presence of an aggravating factor of sand texture in all horizons, resulting in high risks of erosion events, especially in high slopes areas, and contamination by pollutants due the high soil permeability. Conclusions: It was verified that the more critical regions for land use capacity classes were VIs and mainly VIes class. The last one has more high relief areas and the presence of Neossolo Quartzarenico soil, with a big erosion propensity. The land use capacity map allow making different decisions for each region of the watershed respecting their individual characteristics.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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This work aimed to carry out a study of the environmental conditions of the Permanent Preservation Areas (PPAs) in the sub-basin of Marimbondo Stream in the city of Jales (SP), through remote sensing techniques and taking as the basis Brazilian environmental legislation, the Forest Code Federal Law Nº 12,651/2012. Permanent Preservation Areas are inserted intrinsically improved conditions in the quantity and quality of water in the areas of springs and along water bodies in rural properties. Therefore, we also carried out studies on the new Forest Code compared to the old Federal Law Order no. 4771/1965 and the observation of its application in the area of sub-basin as well as carrying out the simulation. The results of this research allowed toverify the need for direct implementation of the monitoring measures with the Forest Code, and this water management tool in Brazil, which will ensure sustainable management practices of land use and land cover, with direct benefits to water production, mainly for public supply. Also there was a greater need for involvement by the public actors, the Basin Committee of the São José dos Dourados and the municipal government of Jales, in order to truly act aimed at the protection and maintenance of the water body Stream Wasp

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Pós-graduação em Geociências e Meio Ambiente - IGCE