5 resultados para Mines and mining

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

80.00% 80.00%

Publicador:

Resumo:

The progress of a nation is closely linked to the energy supply that it has to develop its economic capabilities. The dependence of contemporary society for energy requires the continued expansion of the use of renewable energy, and implies coordinated action of the Democratic State in the delimitation of the best ways to make full use of energy. In periods of rapid development, countries need an increment of energy supplies superior to those of periods of regular economic growth. Energy demand generated by the condition of Brazil as an emerging country reveals the need for orderly expansion of energy supply. In reverse, lack of energy planning effectively paralyzes a country and generates incalculable losses in national socioeconomic development. The Brazilian Constitution abandoned the notion of development tied to the simple increase in the gross domestic product. The respect for the environment, sovereignty, national development, and especially the constant and growing supply of energy, promotes the advancement of national economic agents, and quenches the simple accounting increase in energy supply. Constitutional principles condition the rational use of energy potentials, in ensuring adequate supply of energy for the entire national territory. The Brazilian Ministry of Mines and Energy, through its agencies, government offices and companies, establishes and formulates policies and guidelines for energy in Brazil, playing an important role in national energy planning. National development is enhanced by the good performance of the state agencies responsible for planning the energy sector

Relevância:

80.00% 80.00%

Publicador:

Resumo:

The production of the red pottery brick, made traditionally with clay, is a technique that is already stabled. However, in spite of the little complexity that involves the conventional process of these bricks production, it are exposed to many problems that begin in the fase of exploration of the mines, the problems get worse because of the lack of the clay's characterization, and they continue through the steps of the dough preparation, conformation of the products, the drying and the burning process. The wastefulness is shown and so is the low quality of the material produced. Among other factors, the high use of energy in the burning makes the cost of this material inaccessible to the low income consumer. Besides this, the destruction of the environment around the mines and the use of native vegetation to produce wood - the most used fuel in the pottery industry - make serious environmental damage. The production technique of a new type of simple brick (adobe), that has low cost and no environmental damage, can be the viable altemative to lower the cost of this part of the civil construction, and, consequently, in the building of cheaper houses. In this paper, the results of the mechanical resistance of the adobe brick are shown, using in its composition, clay, natural vegetable fibers, cement and plaster in a process that is completely handcrafted and manual. It is intented to make clear that are possible alternatives to be put in practice, with the simple process, using "raw earth" that has been used in the construction of houses in thousands of years, trying to solve these severe problems. Analysis and tests were performed to find results that could prove the possibility of the utilization of this kind of material. Other studies are in progress, and the new researches are necessary to enrich this work, but it stays the certainty that there is potential to produce bricks from adobe, as an alternative that has low cost to civil construction

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Considering that the Jesuitical tradition which Father Samuel Fritz belonged, has a clear political and institutional dimension that reveals itself in the missionary initiative placed since the Trento Council, his journal is a experience story as missionary at Maynás region during the period from 1686 until 1725. In his narrative, a series of data related to the conquer of Amazonia, conflicts among the Iberic Kingdoms and french, dutches and british, transformation of culture and space close the period of the Madrid Deal. I´ll explore the men and space relationship, in this case, the missionary in his special practice, therefore an effective and geometrical politic for border control was only applied at 1750 with reformist governments and that Amazônia was, until now, an object of autonomous initiatives, not being until now a priority focused state politics action like the ones in the central regions (silver mines) and that the missionary action of Samuel Fritz represented ant that moment represented the most important border advance to the Spanish Kingdom, coinciding with the end of the borders previously set in Madrid and Santo Idelfonso, I´ll put the question of how and with which politics the experience of Fritz in Maynás could represent an advance about Amazônia space. Then I´ll approach the problem about three aspects that are chapters: The first one was focused to the Iberic Kingdoms atlantic politics and the internal geopolitical relationships they created as the centre and the border emerging a new order; in the second chapter I studied the special transformation cause by the encounter and conflicts between the Indian and European order generating a new organization; in the third chapter I´ll examined the political border of the state and the emergency of the missionary body as an institution, with the tradition and missionary action as support, or not, to the exploration of the east border of Spanish America influencing the delimitation process of the border between Portugal and Spain

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Vriesea minarum is a rupiculous bromeliad species, with naturally fragmented populations, restricted to the Iron Quadrangle, Minas Gerais, Brazil. It is a threatened species, which is suffering from habitat loss due to the growth of cities and mining activities. The knowledge of genetic variability in plant populations is one of the main branches of conservation genetics, linking genetic data to conservation strategies while the knowledge about plant reproductive biology can aid in understanding key aspects of their life story, as well as in the comprehension of their distribution and survival strategies. Thus, the study of diversity, richness, and genetic structure, as well as the reproductive biology of populations of V. minarum can contribute to the development of conservation actions. Chapter 1 presents the transferability of 14 microsatellite loci for V. minarum. Among the results of this chapter, we highlight the successful transferability of 10 microsatellite loci described for other species of Bromeliaceae, all of which are polymorphic. In Chapter 2, we present the genetic analyses of 12 populations of V. minarum that are distributed throughout the Iron Quadrangle. We used the 10 microsatellite loci tested in Chapter 1. The results show a low population structuring (Fst = 0.088), but with different values of genetic richness (mean = 2.566) and gene diversity (mean = 0.635) for all populations; and a high inbreeding coefficient (Gis = 0.376). These may be the result of pollinators action and/or efficient seed dispersal, thus allowing a high connectivity among populations of naturally fragmented outcrops. The reproductive biology and floral morphology of a population of V. minarum, located in the Parque Estadual da Serra do Rola-Moça, are studied in Chapter 3. This reserve is the only public environmental protection area where the species occurs. As a result of field experiments and observations, we found that the species has its flowering period from January to March, with flowers that last for two days and that it has a mixed pollination syndrome. It is primarily alogamous, but also has the capacity to be self-ferilized. It is expected that data obtained in chapters 1, 2 and 3 serve as basis for other studies with species from the ferruginous rocky fields, since until now, to our knowledge, there are no other survey of endemic species from the Iron Quadrangle, seeking to merge the genetic knowledge, with the data of the reproductive biology, with the ultimate aim of biodiversity conservation. Considering the great habitat loss for the species by mining, it becomes crucial to analyze the creation of new protected areas for its conservation

Relevância:

80.00% 80.00%

Publicador:

Resumo:

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