355 resultados para Pureza


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The growing utilization of surfactants in several different areas of industry has led to an increase on the studies involving solutions containing this type of molecules. Due to its amphiphilic nature, its molecule presents one polar part and one nonpolar end, which easily interacts with other molecules, being able to modify the media properties. When the concentration in which its monomers are saturated, the airliquid system interface is reached, causing a decrease in interfacial tension. The surfactants from pure fatty acids containing C8, C12 and C16 carbonic chains were synthesized in an alcoholic media using sodium hydroxide. They were characterized via thermal analysis (DTA and DTG) and via infrared spectroscopy, with the intention of observing their purity. Physical and chemical properties such as superficial tension, critical micelle concentration (c.m.c), surfactant excess on surface and Gibbs free energy of micellization were determined in order to understand the behaviour of these molecules with an aqueous media. Pseudo-ternary phase diagrams were obtained aiming to limit the Windsor equilibria conditions so it could be possible to understand how the surfactants carbonic chain size contributes to the microemulsion region. Solutions with known concentrations were prepared to study how the surfactants can influence the dynamic light scattering spectroscopy (DLS) and how the diffusion coefficient is influenced when the media concentration is altered. The results showed the variation on the chain size of the studied surfactant lipophilic part allows the conception of surfactants with similar interfacial properties, but dependent on the size of the lipophilic part of the surfactant. This variation causes the surfactant to have less tendency of microemulsionate oil in water. Another observed result is that the n-alcanes molecule size promoted a decrease on the microemulsion region on the obtained phase diagrams

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Provide data and information on watershed becomes important since the knowledge of their physical characteristics, land use, etcetera, allows for better planning and sustainable use of economically, socially and environmentally in this area. The investigation of the physical environment has been commonly given with the use of geoprocessing, which has proved a very efficient tool. Within this context, this research aims at analyzing the river basin Punaú (located in the cities of Touros, Rio do Fogo and Pureza, state of Rio Grande do Norte) in several aspects, using geoprocessing as a tool of work, to provide information about the entire watershed. Specifically, this study aimed to update pre-existing maps, such as geological, geomorphological and land use, generating map of environmental vulnerability, under the aspect of erosion susceptibility of the area, generating map of legal incompatibility, identifying areas that are already being employed in breach of environmental legislation; propose solutions to the occupation of the river basin Punaú, focused on environmental planning. The methodology was based on the use of geoprocessing tools for data analysis and to make maps of legal incompatibility and environmental vulnerability. For the first map was taken into account the environmental legislation regarding the protection of watersheds. For the vulnerability analysis, the generated map was the result of crossing the maps of geology, geomorphology, soils and land use, having been assigned weights to different attributes of thematic maps, generating a map of environmental vulnerability in relation to susceptibility to erosion. The analysis results indicate that agriculture is the most significant activity in the basin, in total occupied area, which confers a high degree of environmental vulnerability in most of the basin, and some agricultural areas eventually develop in a manner inconsistent with Brazilian environmental legislation. It is proposed to consider deploying a measure of revitalization of the watershed in more critical areas and conservation through mitigation measures on the causes of environmental degradation, such as protection of water sources, protection and restoration of riparian vegetation, protection of permanent preservation areas, containment of erosion processes in general, and others listed or not in specific laws, and even the establishment of a committee of basins in the area

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One of the most important natural resources for sustaining human life, water, has been losing the basic requirements of quality and quantity sufficient enough to attend the population due to water contamination'problems, often caused by human beings themselves. Because of this, the sources of this resource are often located in remote places of the natural environment to ensure the quality of the water. However, when urban expansion began to occupy these areas, which were once regarded as distant, environmental pollution problems began to occur due to occupation of the land without planning. Based on this occurrence, this study aims to propose environmental zoning for the Maxaranguape river watershed in order to protect its water resources. This is important because this river can serve as a source of supply for the metropolitan area of Natal, the capital of Rio Grande do Norte. In accordance to this proposition, the model of natural soil loss vulnerability (CREPANI et al., 2001), the model of aquifer pollution vulnerability (FOSTER et al., 2006), and the legal incompatibility map (CREPANI et al., 2001) were used to delimit the zones. All this was done with Geographic Information System (GIS) and also created a geographic database update of the basin. The results of the first model mentioned indicated that 63.67% of the basin was classified as moderately stable / vulnerable, 35.66% as moderately vulnerable, and 0.67% as vulnerable. The areas with high vulnerability degree correspond with sand dunes and river channels areas. The second model indicated that 2.84% of the basin has low vulnerability, 70.27%) has median vulnerability, and 26.76% and 0.13% has high vulnerability and extreme vulnerability, respectively. The areas with the highest vulnerability values also refer to part of the sand dunes and river channels besides other areas such as Pureza urban area. The legal incompatibility map indicated that the basin has 85.02 km2 of Permanent Protection Area (PPA) and 14.62% of this area has some incongruity of use. Based on these results it was possible to draw three main zones: Protection and Sustainable Use Zone (PSUZ), Protection and Environmental Restoration Zone (PERZ) and Environmental Control Zone, which are divided into A, B and C. The PSUZ refer to the coastal areas of the basin, where the sand dunes are located. These sites should be areas of environmental protection and of sustainable urban expansion. The ZPRA refer to river channels, which are in high need of rehabilitation. The third zone corresponds to the rest of the basin which should have, in general, the mapping of possible sources of contamination for further control on the use and occupation of the river

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We present a study of nanostructured magnetic multilayer systems in order to syn- thesize and analyze the properties of periodic and quasiperiodic structures. This work evolved from the deployment and improvement of the sputtering technique in our labora- tories, through development of a methodology to synthesize single crystal ultrathin Fe (100) films, to the final goal of growing periodic and quasiperiodic Fe/Cr multilayers and investi- gating bilinear and biquadratic exchange coupling between ferromagnetic layer dependence for each generation. Initially we systematically studied the related effects between deposition parameters and the magnetic properties of ultrathin Fe films, grown by DC magnetron sput- tering on MgO(100) substrates. We modified deposition temperature and film thickness, in order to improve production and reproduction of nanostructured monocrystalline Fe films. For this set of samples we measured MOKE, FMR, AFM and XPS, with the aim of investi- gating their magnocrystalline and structural properties. From the magnetic viewpoint, the MOKE and FMR results showed an increase in magnetocrystalline anisotropy due to in- creased temperature. AFM measurements provided information about thickness and surface roughness, whereas XPS results were used to analyze film purity. The best set of parame- ters was used in the next stage: investigation of the structural effect on magnetic multilayer properties. In this stage multilayers composed of interspersed Fe and Cr films are deposited, following the Fibonacci periodic and quasiperiodic growth sequence on MgO (100) substrates. The behavior of MOKE and FMR curves exhibit bilinear and biquadratic exchange coupling between the ferromagnetic layers. By computationally adjusting magnetization curves, it was possible to determine the nature and intensity of the interaction between adjacent Fe layers. After finding the global minimum of magnetic energy, we used the equilibrium an- gles to obtain magnetization and magnetoresistance curves. The results observed over the course of this study demonstrate the efficiency and versatility of the sputtering technique in the synthesis of ultrathin films and high-quality multilayers. This allows the deposition of magnetic nanostructures with well-defined magnetization and magnetoresistance parameters and possible technological applications

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

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Hybrids among transgenic plants and related species are expected to occur if they are sympatric and when there are not crossing barriers; as is the case, in Brazil, of cry1Ac transgenic cotton and Gossypium barbadense. This species has been maintained as dooryard plants, and should be preserved as a genetic resource. Hybrids were evaluated about traits related to fitness, leading to infer about its chances of survivor and selection. A barbadense genotype collected at the state of Mato Grosso was outcrossed to the variety DP 404, containing the gene cry1Ac, and to the isoline DP 404. All the F1 individuals and 122 among 170 F2 individuals expressed the toxin, and presented levels of resistance to pink bollworm (Pectinophora gossypiella) and cotton leafworm (Alabama argillacea) equivalent to the transgenic parent and superior to the isoline, barbadense or non transgenic hybrids. The percentage of germination and number of days to germinate did not differ among genotypes. Anthesis of the first flower and opening of the first cotton boll occurred earlier for herbaceous cotton and F1 hybrids than F2 population in average; all the populations presented a number of days to flower and opening of the first boll smaller then barbadense. The highest plants were barbadenses, and herbaceus the smallest, with F1 and F2 populations presenting intermediary heights. The number of seeds per plants were superior for F1 hybrids an herbaceous cotton, F2 populations were in average intermediary; the barbadense genotype produced the smallest number of seeds per plant. Pink bollworm, mainly, and also cotton leafworm, are important barbadense pests, so the transgene positive effect could favor the selection of hybrids, and hence G. hirsutum genome, against the maintenance of pure G. barbadense genome. The selection may be influenced by the plant uses: the smaller size of hybrids when compared to the barbadense may lead them to be differentiated from these parents to which medicinal properties are attributed; on the other hand, the greater boll production may favor hybrids maintenance with the purpose of producing lamp wicks, or use as an ornamental or swab

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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To investigate the possibilities and limits of mechanisms of participativa management in the scope of the Pronaf - National Program of Fortalecimento of Familiar Agriculture, and the corresponding effectiveness of its actions in the construction of alternatives of sustainable agricultural development in the Coast North of the State of the Great River of the North, more specifically, in the composed Subzona de Touros for the cities of Bulls, White Well, Pureness, Is Miguel of the Gostoso and Taipu. To carry through this analysis they had been carried through Research of Field with the objective to reconstitute the trajectory of the CMDRS, to trace the profile of the citizens that compose each one of the five advice, its expectations, interests and the level of participation of the local population

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In this work we have developed a way to grow Fe/MgO(100) monocrystals by magnetron sputtering DC. We investigated the growing in a temperature range among 100 oC and 300 oC. Structural and magneto-crystalline properties were studied by different experimental techniques. Thickness and surface roughness of the films were investigated by atomic force microscopy, while magneto-crystalline properties were investigated by magneto-optical Kerr effect and ferromagnetic resonance. Our results show that as we increase the deposition temperature, the magneto-crystalline anisotropy of the films also increases, following the equation of Avrami. The best temperature value to make a film is 300 oC. As the main result, we built a base of magnetoresistence devices and as an aplication, we present measurements of Fe/Cr/Fe trilayer coupling. In a second work we investigated the temperature dependence of the first three interlayer spacings of Ag(100) surface using low energy electron diffraction. A linear expansion model of crystal surface was used and the values of Debye temperatures of the first two layers and thermal expansion coefficient were determinated. A relaxation of 1% was found for Ag(100) surface and these results are matched with faces (110) and (111) of the silver. iv

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Hydrographic basins always exercised a big fascination over humankind that attracted for its scenery beauty or for its richness in natural resources, had been acting in order to modify these important ecosystems without, therefore, considering the possible consequences of these changes. The attributed importance to the coast ecosystems, in eminence to the hydrographic basin of Punaú river and adjacent areas, is had when it s verified the diversity of the ecosystems that contemplate it. Hydrographic basin in evidence in Rio Grande do Norte state, occupies an area of nearly 652.71 km², being it sited in the homogeneous micro-region Litoral Nordeste, with a regional population estimated in nearly 75,188 inhabitants, according to the Anuário Estatístico do Rio Grande do Norte 2004. The region of the researched basin is formed by seven municipal districts related as it follows: Maxaranguape, Pedra Grande, Pureza, Rio do Fogo, São Miguel de Touros, Taipu and Touros, but Maxaranguape, Rio do Fogo, Touros and Pureza have a direct participation in the basin. Basin in study have it lands evaluated according to the agriculturist aptitude by the conventionally methodology practiced in the country, having as objective, then, a compara-tive analysis between the ambient unities, Aeolian littoral and coast tray, identified in the researched area. From the characterization of the physic way of the area in study and owning the kept data, it was proceeded the integrated analysis of the structural elements of the landscape which were evidenced that the fragile areas are associated with the areas of agriculture cultivation, such as the ones of irregular occupation. About the degradation, the ambient diagnostic of the basin indicated that the equivalent to the Aeolian Littoral Ambient Unit correspond to the bigger pledging of the ambient quality, in other words, high ambient fragility, being this result due to the use and occupation of the soil, propitiating this way, vulnerability in the vegetal cover of the area, despite it disposes of a low agriculture cultivation percentage. Already in the Coast Ambient Tray, is emphasized the medium ambient fragility, despite of the high index of cultivated area. In a general way, the total area of the hydrographic basin of Punaú river and adjacent areas presented ambient impacts over the tolerance limit, indicating the necessity of a review of the practices of use and handling of the soil, reforesting of the water courses edges, control of erosion and contamination of the aqueous in the perspective to reduce the effects of the impacts due to the use and occupation of the basin in regard. The present search evaluated the ambient impacts diagnosised in the hydrographic basin of Punaú river and adjacent areas, pointing the causes and the probable consequences of the damages caused by these impacts to the basin ambient. From the analysis of these data, if was possible to become explicit how they are fundamental as key elements in the process of decision taking in the ambient questions

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Entre os avanços da engenharia celular e biotecnologia nas últimas décadas, destaca-se a produção de anticorpos monoclonais murinos (AcMm) utilizados no aprimoramento diagnóstico nas rotinas laboratoriais. A produção de fator VIII de alta pureza sempre foi o desejo e a preocupação das indústrias de hemoderivados para tratamento de pacientes portadores de hemofilia A, porém este produto inexiste no Brasil, sendo necessária sua obtenção no mercado internacional a custos elevados. O trabalho tem por objetivo a produção de AcMm anti-fator VIII humano (FVIII H) através da expansão dos clones e caracterização imunoquímica do anticorpo. Camundongos Balb/c foram imunizados com FVIII H purificado como também proveniente de crioprecipitado e as células esplênicas dos animais foram fusionadas com células mielomatosas murinas segundo o método descrito por Kohler e Milstein para produção de híbridos em cultura. Foram testados 1.983 híbridos dos quais 105 foram submetidos à clonagem. Destes, 39 obtiveram monoclonalidade e 7 destes clones foram caracterizados através de técnicas de immunoblotting. Foram submetidas à purificação por cromatografia três imunoglobulinas de diferentes classes pertencentes aos clones LAMB1-10A1A4, LAMB1-17A1A1 e LAMB1-24A2A1. A imunoglobulina purificada pertencente ao clone LAMB1-10A1A4 foi adsorvida em coluna de imunoafinidade para purificação de concentrado de FVIII proveniente de crioprecipitado plasmático.

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Este trabalho teve por finalidade a análise histoquímica foliar de dois genótipos de amendoim (Arachis hypogaea L.), do tipo botânico Valência: SO-53 ('Tatu') e SO-909 (PI-259747), cuja literatura demonstra apresentarem respostas diferentes de resistência às principais moléstias fúngicas foliares do Brasil. Seções transversais das seguintes estruturas - pulvino, haste peciolar, raque, pulvínulo e folíolo - e seções paradérmicas de folíolos coletados em dois anos agrícolas consecutivos, foram analisadas quanto à presença de alcalóides, amido, calose, celulose pura, celulose com pectina, cera, cristais, cutina, lignina, mucilagem, óleo, resina, tanino e ureídeos (micrograma) por folíolo (grama). As diferenças qualitativas histoquímicas observadas nos diversos tecidos, como a freqüência de tanino, alcalóide, pectina e óleo, supostamente, podem ser responsáveis pela resistência ou suscetibilidade dos genótipos às moléstias fúngicas foliares. Para fins de caracterização, mostrou-se eficiente a avaliação de pureza de celulose.

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O ácido 2-metoxicinamalpirúvico (2-MeO-HCP) foi sintetizado e caracterizado por ressonância magnética nuclear (¹H and 13C NMR), espectrometria de massas (MS), espectroscopia na região do infravermelho (FTIR) e calorimetria exploratória diferencial (DSC). A técnica DSC foi usada para determinação da pureza do composto e as principais bandas de absorção na região do infravermelho foram atribuídas utilizando-se o programa GaussView 3.0.