Estudo da oxidação superficial de ligas odontológicas de Ni-Cr em plasma pulsado para uso em restaurações metalocerâmicas

Metal ceramic restorations matches aesthetic and strength, and in your making occurs an interface oxide layer, wetting resulting and atomic and ionic interactions resulting between metal, oxide and porcelain. However, frequent clinical fails occurs in this restoration type, because lost homogeneous deposition oxide layer and lost interface bond. Thus, in this study, thought depositate homogeneous oxide films above Ni-Cr samples surfaces polite previously, at plasma oxide environment. Six samples was oxided at 300 and 400ºC at one hour, and two samples was oxided in a comum chamber at 900ºC, and then were characterized: optical microscopic, electronic microscopic, micro hardness, and X ray difratometry. Colors stripes were observed at six samples plasma oxided and a grey surface those comum oxided, thus like: hardness increase, and several oxides from basic metals (Ni-Cr)

Balanço energético de um forno túnel de cerâmica estrutural convertido de lenha para gás natural

In energy systems, the balance of entrances, exits and losses are fundamental to rationalize the energy consumption, independently of the source (sun, natural gas, wind, water, firewood or oil). This estimate is important so much in the phase of project of the facilities, as in the exploration or operation. In the project phase it indicates the energy needs of the process and the contribution of the energy in the cost of the product and the capacity of storage of the fuel and in the operation phase it allows to evaluate the use of the energy in the process of it burns, showing the weak points that should suffer intervention to improve the efficiency. With this tool, it can be implemented routines of calculation of thermal balances in ovens of it burns of structural ceramic, in way to generate an optimized mathematical model for application in the current and promising structural ceramic brazilian industry. The ceramic oven in study is located in the metropolitan area of Natal (Rio Grande do Norte) and it is a continuous oven of the type wagons tunnel, converted of firewood for natural gas and it produces blocks of red ceramic. The energy balance was applied in the oven tunnel before and after the conversion and made the comparisons of the energy efficiencies (it burns to the firewood and it burns to natural gas), what showed that the gaseous fuel is more efficient when we burn structural ceramic in ovens tunnels. When we burn natural gas, the requested energy is smaller and better used. Tests were accomplished in the burned product that showed the best quality of the burned brick with natural gas. That quality improvement makes possible to accomplish new interventions for the most rational use of the energy in the oven tunnel of the Ceramic in study and in the industries of structural ceramic of the whole Brazil, that need control tools of burning and of quality

Distribuição espacial, formação de grupos, uso do hábitat e ecologia comportamental de jovens de tubarão limão, negaprion brevirostris (poey 1868), no arquipélago de fernando de noronha

Lemon sharks, Negaprion brevirostris, are common in the Fernando de Noronha Archipelago, but detailed information about the species in this site is lacking. The aim of this study was to describe the spatial distribution, grouping behavior, habitat use and behavioral ecology of juvenile lemon sharks in the archipelago, and their interaction with some environmental and ecological factors. During 2006 and 2007, the presence and spatial distribution of juvenile sharks were quantified through scuba diving and snorkeling at several sites of the archipelago. In 2008 the habitat use of juvenile sharks was quantified through visual census while snorkeling along 300 x 8 m strip transects. During these transects the grouping behavior of lemon sharks was quantified by ad libitum. Results indicate that Fernando de Noronha Archipelago is used as a nursery area for lemon sharks, and the parturition occurs from November to April. Juveniles preferred using shallower areas available by the tide variation and formed groups only in the presence of adult conspecifics. This preference for shallower habitats and the group behavior probably are anti-predatory tactics used by juvenile lemon sharks, in response to the low availability of shelter and high predation risk of the studied areas. Quantifications of prey availability and predation risk of juveniles showed that, in general, lemon sharks are trading-off food by security and investing in sites with higher possibility of energetic return. Behavioral observations enabled to record juvenile carangid fishes following juvenile lemon sharks, remora host-parasite and juvenile sharks foraging on schools of herrings and octopuses. We also recorded the behavior of juvenile sharks following conspecifics of similar size, circling with two or three individuals and smaller individuals giving way to larger juveniles. When adults are present, juvenile lemon sharks are more social than solitary, indicating that predation is one of the factors that contribute to social behaviors of the species. Results also suggest that when grouped the juveniles have a hierarchical organization according to body size. Furthermore, observation of large adult females with several fresh mating bites and scars in the same habitats used by juvenile lemon sharks, indicates that Fernando de Noronha Archipelago is used as nursery and mating grounds by this species

Análise de uso e cobertura do solo no município de Parelhas/RN

The human interference in the semiarid region of Seridó Potiguar has promoted the increase of degraded areas. The economic dynamic that was established in the Seridó territory, especially after the fall of the trinomial cattle-cotton-mining in the 70s and 80s of the 20th century as pillars of the regional economy, resulted in an accelerated process of erosion of natural resources. The municipalities of the Seridó region have been spatially reordered by this new economic dynamic, marked by the growth of existing enterprises, and the development of new agricultural practices. One of the municipalities in the region that restructured its territorial space with the emergence of new agro-industrial activities was the town of Parelhas. With the demise of the trinomial cattle-cotton-mining in the 1980s, other productive activities were intensified from the 1990s, amongst them, pottery, responsible for the vegetal extraction for use as energy source. This recent economic and spatial restructuring in the region, reflected in the Parelhense municipal territory, required new productive ingredients responsible for the modification of past production relations that were based on cattle, cotton and mining. By that a process of exploring the environment was unleashed, especially the native vegetation, in an uncontrolled manner. In this context, the objective of this study was to survey and detect deforestation in the areas of Caatinga vegetation, used indiscriminately as energy supply for new agricultural practices, using remote sensing techniques based on the quantification of the Normalized Difference Vegetation Index / NDVI, Soil-Adjusted Vegetation Index / SAVI, surface temperature and rainfall data in the years 1990 and 2010. The results indicated that SAVI values above 0.2 in 1990 and 2010 represent the areas with the highest density of vegetation that occur exclusively along the major drainages in the town and areas of higher elevations. The areas between the ranges of values from 0.5 to 0.15 SAVI are areas with poor vegetation. On the other hand the highest values of temperature are distributed in the western and southeastern parts of the township, usually in places where the soil is exposed or there is sparse vegetation. The areas of bare soil decreased in extension in 2010 at 11, 6% when related to 1990, this was caused by a higher rainfall intensity in the first half of 2010, but no regeneration of vegetation occurred in some places in the western and southeastern areas of the municipality today, due to the extraction of firewood to fuel the furnaces of industries in town

Valor energético do óleo ácido de soja para aves

A escassez de valores confiáveis de energia metabolizável tem limitado o uso do óleo ácido de soja como fonte de energia, nas rações de aves. O objetivo deste trabalho foi verificar o efeito da idade da ave e do método de determinação nos valores de energia metabolizável do óleo ácido de soja comercial. No primeiro e segundo ensaios, foi utilizado o método da coleta total de excretas, com pintos de 12 a 20 dias de idade e com galos adultos, respectivamente. No terceiro ensaio, foi utilizado o método Sibbald com galos adultos. em todos os ensaios, utilizou-se uma ração-referência e uma ração-teste, composta por 10% de óleo ácido de soja e 90% da ração de referência. No método da coleta total de excretas, a energia metabolizável aparente corrigida determinada foi de 7.488 e de 8.610 kcal kg-1 de matéria seca para pintos e galos, respectivamente. A energia metabolizável verdadeira corrigida, determinada pelo método Sibbald, com galos, foi de 8.195 kcal kg-1 de matéria seca. Os valores de energia metabolizável, determinados com galos, foram superiores aos determinados com pintos. Portanto, na formulação de rações para aves, deve-se considerar as diferenças nos valores energéticos do óleo ácido de soja, para aves jovens e adultas.

El método DEA y su aplicación al estudio del sector energético y las emisiones de CO2 en América Latina y el Caribe

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El papel de la legislación y la regulación en las políticas de uso eficiente de la energía en la Unión Europea y sus Estados Miembros

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Las reformas energéticas y el uso eficiente de la energía en el Perú

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Proyecto de reforma a la Ley No 7447 "Regulación del uso racional de la energía" en Costa Rica

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Reformas del sector energético, desafíos regulatorios y desarrollo sustentable en Europa y América Latina

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Tercer Diálogo Parlamentario Europa-América Latina para la Promoción del Uso Eficiente de la Energía

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Energía y pobreza: los problemas del desarrollo energético y los grupos sociales marginados en las zonas rurales y urbanas de Brasil

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