99 resultados para Episódios de frio intenso

em Universidade Federal do Rio Grande do Norte(UFRN)


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Research for better performance materials in biomedical applications are constants. Thus recent studies aimed at the development of new techniques for modification of surfaces. The low pressure plasma has been highlighted for its versatility and for being environmentally friendly, achieving good results in the modification of physic chemical properties of materials. However, it is requires an expensive vacuum system and cannot able to generate superficial changes in specific regions. Furthermore, it is limits their use in polymeric materials and sensitive terms due to high process temperatures. Therefore, new techniques capable of generating cold plasma at atmospheric pressure (APPJ) were created. In order to perform surface treatments on biomaterials in specific regions was built a prototype capable of generating a cold plasma jet. The prototype plasma generator consists of a high voltage source, a support arm, sample port and a nozzle through which the ionized argon. The device was formed to a dielectric tube and two electrodes. This work was varied some parameters such as position between electrodes, voltage and electrical frequency to verify the behavior of glow discharges. The disc of titanium was polished and there was a surface modification. The power consumed, length, intensity and surface modifications of titanium were analyzed. The energy consumed during the discharges was observed by the Lissajous figure method. To check the length of the jets was realized with Image Pro Plus software. The modifications of the titanium surfaces were observed by optical microscopy (OM ) and atomic force microscopy (AFM ). The study showed that variations of the parameters such as voltage, frequency and geometric position between the electrodes influence the formation of the plasma jet. It was concluded that the plasma jet near room temperature and atmospheric pressure was able to cause modifications in titanium surface

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This study is the analysis of cultural, political and organizational interfaces of "Caminhos do Frio Rota Cultural" Project in the context of tourism regionalization in Brejo Paraibano and it presents the characterization, routing and inventory of six municipalities of the Project, as well as the identification of cultural elements used for tourist in the routing of the pond, the investigation of political and organizational articulation and the verification of participation of each producing agent in the development of tourism resulting from the swamp of Paraiba. This is a qualitative descriptive and exploratory study, which makes use of the interpretive paradigm to perform an analysis of the environment where occurs the regionalization of tourism in Brejo of Paraíba and the social actors involved in this process in order to pursue development of the region through culture and tourism, with the collection spot in the six counties of the Project participants collected through interviews with managers, community, government agencies and tourist trade, and the use of the technique of direct observation. This time, with the data analysis it was possible to establish the production situation and its cultural and tourist development in the region of Brejo (PB), where culture has become a developmental tool within the tourism industry due to its innovation potential. It was possible to ratify the undisputed vocation of cultural tourism in the region in question, since other projects being developed with the use of cultural resources with a strong influence on the policies of regional tourism. Thus, the main result was that was seen is that the regional development has triggered a refunctionalisation / reappropriation of space just rebuilding a new territorial organization through the development of a regional autonomy of management, a capacity of collective ownership and the use of economic surplus, a spontaneous process of social inclusion as well as awareness and mobilization tourist (even if initial and shy), an appreciation of natural and cultural assets for all stakeholders and especially identification of the population with its region and its culture, as to achieve regional development is not enough to increase the economic, but above all the promotion of endogenous social factors such as changes in social and cultural values and the integration of social actors in this process. Finally, taking into account the definitions of sustainability, it is considered that cannot be said that the development model seen in the swamp of Paraiba is sustainable, but it is a model of regional development based on the unique characteristics that each municipality has and create a regional identity and have correponded expectations / desired results and therefore the viability of the region through the development of cultural tourism was proven

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Surface defects on steel parts borne costs of smelting industries due to the need of rework. Sand molds are frequently used in foundry industries and largely responsible for providing surface defects. This study aims to optimize the levels of the molding process variables to minimize the occurrence of surface defects in steel castings in silica sand molds chemically linked by cold cure process. The methodology used the experimental design with split plot, being considered in the study the resin percentage factors in the mold formulation, addition of iron oxide, type of paint, the paint application method, amount of ink layers, use of hot air along the lines and waiting time of the mold before casting. They were analyzed as response variables erosion defects, sand inclusion, penetration, porosity and surface finish. Tensile strength tests were performed to evaluate the influence of factors on mechanical parameters and the microstructural parameters were carried out the analysis of X-ray diffraction, scanning electron microscopy (SEM) and thermal analysis (TG / DSC / dilatometry). The results elucidate that for the faulty erosion, the only significant factor with a 95% confidence level was the type of ink and the ink alumina-based superior results obtained. For the sand inclusion of defect, there were three significant factors, with best results obtained with alumina-based paint and spray applied using hot air in the mold before casting the metal. For the defect penetration, there were four significant factors, the best results being achieved with 0.8% of resin and addition of iron oxide in the molding formulation, the paint being applied by brush and standby time of 24 hours before leak. For the defect porosity with a 95% confidence level, no significant factors. For the defect surface finish, the best results were achieved with the 0.8% formulation of the resin in the mold and application of the paint brush. To obtain the levels of the factors that optimize all defects simultaneously, we performed a weighted average of the results of each type of fault, concluding that the best levels of the factors were: 0.8% resin and addition of iron oxide in the formulation of the template, application of two coats of paint applied with a brush or spray, using hot air in the mold before casting and 24 hours of waiting ready the mold before casting. These levels of the optimized factors were used in an experiment to confirm that ratified the results, helping to reduce rework and consequently reducing costs of cast steel parts.

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The relationship between the State and the non-governmental organizations (NGOs) needs to be analyzed and debated by the objective to extinguish or to reduce the existent failures in this partnership in order that the whole society may benefit from it. To understand how the partnership between the public and NGOs work is fundamental. The present study searches to contribute to a better understanding of this matter. With this aim, the research focused the partnership formed between Natal Child and Adolescent Council (COMDICA) and NGOs which were selected by public notice in 2007. Theoretical references were based on the Continuum of Collaboration proposed by Austin (2001) that serves to differentiate the degree and the mode of interaction between the two organizations. It was observed that in some points there is a lack in the interaction between COMDICA and the NGOs. The frequent change of the government counselors makes difficult a more intense involvement and partnership awareness with the NGOs. The NGOs members need to be more involved with the activities of COMDICA and search for a larger participation in the assemblies, on the discussions and on the intrinsic council actions. The relationship must also be rethought, since that the partnership must not be limited to financial resources support. The channels of communication must be improved and become more frequent. The evaluation and monitoring of social projects are poor and own methodologies need to be elaborated. Therefore, it is necessary to make some adjustments in this relationship involving not only the partnerships made by the selected ONGs, but also all those who assist the child and the adolescent. A closer relation makes possible a greater effectiveness of the public policies on one side and on the other side improves the performance of the COMDICA and the NGOs

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The transformations economical, cultural and social that happen in world ambit they are associated to the intense progress and expansion of new technologies, forcing governments, people, companies and nations to the introduction of new patterns of behavior, forcing, in that way, to the continuous renewal of products and technological processes to maintain the competitiveness, so much among nations, as in the managerial world. In that matter, the technological innovation is recognized as basic factor of maintainable economical competitiveness, being the responsible for the breaking and/or improvement of the techniques and production processes, what presupposes the systematization varied institutional arrangements that they involve firms, interaction nets among companies, government agencies, universities, research institutes, laboratories of companies and scientists and engineers activities. Those arrangements, to the if they articulate with the educational system, with the industrial and managerial section and, also, with the financial institutions, they take the form that Freeman (1987) it coined of national system of innovation, promoted through public politics of CT&I, which seek to induce and to support innovative initiatives in the companies, as well as to establish demands and to prioritize vocations and regional potentialities. In that context of government support to the technological innovation interferes this study, that it looked for to know the reasons of the fragility innovative in the pharmaceutical industry of State of Pará in Brazil, pointed for PINTEC (2005), starting from the point of view of the businessmen of that section. For such, the qualitative approach was used - with interviews directing semi and the technique of the content analysis. The results of the research pointed that the fragilities innovative of the section links to the ignorance of the government support to the technological innovation on the part of the businessmen of the pharmaceutical industry of State of Pará in Brazil

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Owing to na intense process of urban development, urban uneasiness and discomfort in the daily life of populations have nowadays, especially in the big cities, become increasingly ordinary issues. Population density, degeneration of central areas and pollution are some of the environmental stressors the urban man is subjected to. The existence of open areas in the urban network contributes to a better movement of the air and transforms salubrity conditions. Yet, it has been noticed that parks and squares are disappearing from the heart of the city districts. In their place there are either unused plots of land where garbage has been dumped or nearly all-paved squares with meager or no vegetation at all. Such areas, when handled properly, play an important role in the city because in addition to being zones for rendering a mild climate they perform social, cultural and hygienic functions. Aiming at demonstrating that proper handling of green areas can favorably influence the local microclimate, we have attempted to develop analysis from the point of view of bioclimatizing attributes of urban form and their relationship to the local microclimate found in the eight open areas located in the Ponta Negra Housing Complex in the city of Natal/RN

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This study focuses on the building ensemble of Avenida Roberto Freire, a main road in Natal, Brazil, as a material expression of the confluence of various factors among which the following may be emphasized: high level of accessibility due to urban spatial re-structuring and the growth of the real estate market, in view of the increasing number of consumers, who arrived in Natal within the last decades. The intense urban modification process that has been going on in Natal since at least the 1980s, has engendered the formation of long axial lines which express the expansion dynamics and some of the forces subjacent to it. Avenida Roberto Freire has been an iconic example of an urban thoroughfare where architecture becomes primarily a communication support that can be perceived by fast moving passers-by, what brings it close to the venturian concept of strip (Venturi at al, 1972). The building types that line the road not only respond to the dynamics in process but also contribute to intensify it, as they house a variety of uses which attract people and generate more movement. The dynamics is further strengthened by the action of the real estate business which benefits from the increase of highly accessible locations, and from the private and public investments and incentives to tourism that aim to insert this city into the globalized world. Although the intention of reconstituting part of the history of density increase on this avenue in a diachronical perspective was attempted within the limits of the available references and documentation, the central contribution of this study is to understand the relations between topological accessibility and the typological nature of the building ensemble. By observing the synchronic morphological frame resulting from the spatial configuration analysis pertinent to this avenue (cf. Hillier and Hanson,1984) and the inventory and classification of the building ensemble there existing, this study aims to understand how architecture responds to accessibility in view of the real estate pressure, boosted by a cosmopolitanizing process brought about by the continuous flow of foreign and Brazilian arrivals as visitors, temporary or permanent residents

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The transformations economical, social and politics in you finish them decades of the century XX brought changes that didn't just limit to the production system. The flexible accumulation took many workers lost her/it their workstations and they look for her/it new survival forms, migrating for administrative activities, of services rendered and for the tourist activity of small and medium load. The State has been investing in the implantation of plans of tourist development in order to create favorable conditions for the reproduction of the tourist activity in Brazil, mainly in the Northeast. A space when it starts to present a predominant economical activity suffers a restructuring in their social and economical relationships. The restructuring of these relationships takes to the construction of a new espacialidade. In the city of Christmas, in Rio Grande do Norte, the neighborhood of Black Tip is the most representative of the public investments for the tourist development. After intense process of tourist urbanization, Black Tip passed interfering in the global context consolidating as the tourist locus in the city. The tourist urbanization of the neighborhood took to the transformation of the space in merchandise that is sold and consumed as such. The recreation of fragments of other cultures brought by social actors, resulting from migratory processes stimulated by the tourist development, it has been presenting ruled social relationships in the informational technology, consumption of global goods and in the fragmentation of the urban space characterized by the internationalization and cosmopolitização. That process has been masking the inequalities partners and cultural as well as the territorial appropriation for an economical elite. The spaces are being appropriate for investors of the tourist section, private investors, agents and real estate producers, where the inequality is not just economical, but also cultural. The local population, mainly of the urban fraction of the Town of Black Tip, it doesn't participate of the productive process in function of the little or any professional qualification and he/she doesn't also have access to the consumption process. To the native ones it remains the fight for the preservation of his/her cultural identity and for the survival

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This paper aims at studying how circular dance can afford to sight-disabled peoples movement and how they can learn to cope with the deep movement of relation, consciousness, appropriation and communion with the world. Inside circular dance, a cosmic metaphor, is inscribed the movement of the world, which tells and changes amorously the human history. In the works of Paulo Freire and Maurice Merleau-Ponty one can find the necessary support to discuss, as long as possible, movement and existence. Research-action is used as a methodological approach whose empirical center is placed on the Institute of Education and Rehabilitation of Blind, in Natal, which shelters eight sightdisabled adults. The research s data reveal that the practice of circular dance concurs to enlarge the movement of the research s subjects, to develop a more accurate perception of their selves and of their own capacities, as well as improve the relations Me/Others, Me/World, which require a context of differences. The study has revealed that the practice of dance develops a better perception of the limits and surpasses as a human condition and, in consequence, the discovery of one s own body and the other s body as a resource of lessons and representations of the self and of the world. It lets out the development of a new way of thinking and coping with discrimination surrounding the disabled persons. In movement, in circular dance, the barrier between sight disablement and vision loses force.

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Strandings of live or dead aquatic mammals constitute an important instrument to provide information regarding the occurrence, biology and ecology of these species. The aim of this study was to register the stranded species of cetaceans, the frequency and the spatial-temporal distribution of theses strandings during the period of 1984 to 2005, in the coast of Rio Grande do Norte. Data was acquired through the monitoring of strandings in the north, north-west and south coast of RN, and through information obtained from institutions and newspaper archives of the State. A total of 122 strandings of cetaceans were registered along the coast of Rio Grande do Norte. Of the 14 species of cetaceans registered, four species had higher frequencies: Sotalia guianensis (n= 65), Steno bredanensis (n = 6), Globicephala macrorhynchus (n = 6) and Physeter macrocephalus (n = 7). Out of 118 strandings, 93 occurred in the south coast (78.8 %), 23 in the north coast (19.5%) and 2 (1.7%) in the north-west coast of the State. The highest frequency of strandings occurred during the months of August to March and the maximum number of strandings occurred from 2000 onwards, as a consequence of the intense monitoring of the Pequenos Cetáceos Project in Rio Grande do Norte

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Dopamine (DA) is known to regulate both sleep and memory formations, while sleep plays a critical role in the consolidation of different types of memories. We believe that pharmacological manipulation of dopaminergic pathways might disrupt the sleep-wake cycle, leading to mnemonic deficits, which can be observed in both behavioral and molecular levels. Therefore, here we investigated how systemic injections of haloperidol (0.3 mg/kg), immediately after training in dark and light periods, affects learning assessed in the novel object preference test (NOPT) in mice. We also investigated the hippocampal levels of the plasticity-related proteins Zif-268, brain-derived neurotrophic factor (BDNF) and phosphorylated Ca2+/calmodulin-dependent protein kinases II (CaMKII-P) in non-exposed (naïve), vehicle-injected controls and haloperidol-treated mice at 3, 6 and 12 hours after training in the light period. Haloperidol administration during the light period led to a subsequent impairment in the NOPT. In contrast, preference was not observed during the dark period neither in mice injected with haloperidol, nor in vehicle-injected animals. A partial increase of CaMKII-P in the hippocampal field CA3 of vehicle-injected mice was detected at 3h. Haloperidol-treated mice showed a significant decrease in the dentate gyrus of CaMKII-P levels at 3, 6 and 12h; of Zif-268 levels at 6h, and of BDNF levels at 12h after training. Since the mnemonic effects of haloperidol were only observed in the light period when animals tend to sleep, we suggest that these effects are related to REM sleep disruption after haloperidol injection

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without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming

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The present work shows a contribution to the studies of development and solid sinterization of a metallic matrix composite MMC that has as starter materials 316L stainless steel atomized with water, and two different Tantalum Carbide TaC powders, with averages crystallite sizes of 13.78 nm and 40.66 nm. Aiming the metallic matrix s density and hardness increase was added different nanometric sizes of TaC by dispersion. The 316L stainless steel is an alloy largely used because it s high resistance to corrosion property. Although, its application is limited by the low wear resistance, consequence of its low hardness. Besides this, it shows low sinterability and it cannot be hardened by thermal treatments traditional methods because of the austenitic structure, face centered cubic, stabilized mainly in nickel presence. Steel samples added with TaC 3% wt (each sample with different type of carbide), following a mechanical milling route using conventional mill for 24 hours. Each one of the resulted samples, as well as the pure steel sample, were compacted at 700 MPa, room temperature, without any addictive, uniaxial tension, using a 5 mm diameter cylindrical mold, and quantity calculated to obtain compacted final average height of 5 mm. Subsequently, were sintered in vacuum atmosphere, temperature of 1290ºC, heating rate of 20ºC/min, using different soaking times of 30 and 60 min and cooled at room temperature. The sintered samples were submitted to density and micro-hardness analysis. The TaC reforced samples showed higher density values and an expressive hardness increase. The complementary analysis in optical microscope, scanning electronic microscope and X ray diffractometer, showed that the TaC, processed form, contributed with the hardness increase, by densification, itself hardness and grains growth control at the metallic matrix, segregating itself to the grain boarders

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In this research there was an evaluation of the best conditions of nitriding in plasma within a cathodic cage at an atmosphere of 80% N2-20%H2 in samples of tool manganese steel AISI D6, cold working, treated thermally in the following conditions: tension relief, treated thermally to temperature of maximum heat, temperate heat and temperate and temperate heat. A pressure of 2.5mbar and temperatures of 400 and 300ºC com treatment time of two and three hours were used to evaluate its performance as cutting tool (punch) of bicycle backs. Hardness, micro-structural aspects (layer thickness, interface, grain size etc), and crystal phases on the surface were appraised. When treated to tension relief, thermally treated to maximum heat temperature, temperature and temperate heat, the samples presented hardness levels of 243HV, 231HV, 832HV, and 653HV, respectively. The best nitrification conditions were: four hours and 300ºC for heat samples. A superficial hardness of 1000HV and a 108µm thickness for the nitrided layer were found in these samples

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Metal powder sintering appears to be promising option to achieve new physical and mechanical properties combining raw material with new processing improvements. It interest over many years and continue to gain wide industrial application. Stainless steel is a widely accepted material because high corrosion resistance. However stainless steels have poor sinterability and poor wear resistance due to their low hardness. Metal matrix composite (MMC) combining soft metallic matrix reinforced with carbides or oxides has attracted considerable attention for researchers to improve density and hardness in the bulk material. This thesis focuses on processing 316L stainless steel by addition of 3% wt niobium carbide to control grain growth and improve densification and hardness. The starting powder were water atomized stainless steel manufactured for Höganäs (D 50 = 95.0 μm) and NbC produced in the UFRN and supplied by Aesar Alpha Johnson Matthey Company with medium crystallite size 16.39 nm and 80.35 nm respectively. Samples with addition up to 3% of each NbC were mixed and mechanically milled by 3 routes. The route1 (R1) milled in planetary by 2 hours. The routes 2 (R2) and 3 (R3) milled in a conventional mill by 24 and 48 hours. Each milled samples and pure sample were cold compacted uniaxially in a cylindrical steel die (Ø 5 .0 mm) at 700 MPa, carried out in a vacuum furnace, heated at 1290°C, heating rate 20°C stand by 30 and 60 minutes. The samples containing NbC present higher densities and hardness than those without reinforcement. The results show that nanosized NbC particles precipitate on grain boundary. Thus, promote densification eliminating pores, control grain growth and increase the hardness values