10 resultados para Natural context

em Universidade Federal do Rio Grande do Norte(UFRN)


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The so-called "residential tourism" came to intensify the previous occupation of the coastal zones, characterized by traditional beach houses, and brought significant consequences for their spatial configuration, and especially for its scenic value of the landscape. Although there is the intention to regulate the activities of enterprising groups by some legal instruments to control the use and occupation of land, and to contain some negative effects, the actions of government are still inefficient in trying to follow the implications on the landscape from the accelerated growth of the real estate and touristic sectors. Supported in the speech of economic development and income generation, public managers prioritize areas to attract tourists to the detriment of preserving important physical attributes of the natural environment that contribute significantly to the quality of life. The result can be noticed in the use of natural elements as one of the major components in the land valorization, and in the immediate attraction of investors and enterprising. Therefore, the objective of this work is to contribute to the debate on the landscape preservation a little detailed thematic in view of their relevance in the current context - by indicating subsidies to the creation of a methodology for the evaluation and protection of coastal zones that may assist the government in creating new instruments, and better prepare it in control of the occupation of these areas. For such, was followed two ways to analysis: the indirect method and the direct method. The first is grounded in the evaluation of landscape attributes, which is based on the work of Raquel Tardin (2008) and Eduardo Cuesta, Encarnación Algarra and Isabel Pastor (2001). The second, based on the research of Leticia and Carlos Hardt (2010) and on the concepts of phenomenology - expressed by Antonio Christofoletti (1985) and Yi-Fu Tuan (1983) - considers the population perspective on the quality of the natural scenery. Developed through cartographic materials, photographic collections and quantitative tables, this dissertation utilized as a case study the beaches of Barra de Tabatinga and Camurupim, located in the city of Nísia Floresta/RN. Despite already being sighted spaces of advanced stage of landscape degradation in these locations, areas of remarkable scenic value can still be found, what reinforce the urgency in adopting preservationists actions. The absence of laws focused on the management and protection of the landscape singularities associated with the inefficiency of the government to invigilate the land occupation in coastal zones, encourage the excessive action of the real estate-tourism, and consequently make the government the main responsible for the environmental and landscape impacts in these areas - by its omission or by their connivance. Therefore, the legislation permeates this entire process and constitutes itself as the most effective way to guarantee the right to the landscape to present and future generations. Are also pointed some important considerations to build a methodology, especially concerning possibilities of improvements and adaptations of its applicability in each case

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The construction industry is one of the largest consumers of natural raw materials, and concrete is considered today the most used material wide. This accentuated consumption of natural resources has generated concern with the preservation of the environment, and has motivated various studies related to the use of resid ues, which can partially or entirely substitute, with satisfactory performance, some materials such as the aggregate, and in so doing, decrease the impact on the environment caused by the produced residues. Research has been done to better understand and improve the microstructure of concrete, as well as to understand the mechanism of corrosion in reinforced steel. In this context, this work was developed aiming at discovering the influence of the substitution of natural sand by artificial sand, with rega rd to mechanical resistance, microstructure, and durability. To obtain the electrochemical parameters, an adaptation was made to the galvanostatic electrochemical method to study the corrosion in reinforced steel. Concretes of categories 20 MPa and 40 MPa were produced, containing natural sand, and concretes of the same categories were produced with artificial sand substituting the natural sand, and with the addition of sodium nitrate and sodium chloride. Due to the use of rock dust reject (artificial sand), an evaluation was made of its environmental risk. The results indicate that the concretes of category 20 MPa present a better performance than the concrete made with natural sand, thus making it a viable substitute. For the category 40 MPa, the better performance is from the concrete containing natural sand. The adaptation of the galvanostatic electrochemical technique to the study of the corrosion of reinforced steel within concrete proved to be valid for obtaining electrochemical parameters with a high degree of reliability, considering the number of degrees of freedom

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In a country of continental dimensions as Brazil, one of the top challenges to its economic growth is the logistic related to energetical demand supply. We live now in the era of environmental protection and, in this new context of priorizations, it passes trough the search for alternative energies for the energetic matrix, due the petroleum elevated costs in the global market (and its finitude), but also due its pollution over the environment. This attempt of substitution needs solutions related to the national reality, into a national long term developing plan and based at a juridical-economic analysis of its realization. This study will look for, also based in an economical analysis, the juridical legitimity of choosing natural gas as the new protagonist of national economic growth (as a substitute of petroleum) and the necessary boost that must be done by law, based on an economic policy focused strictly for that fact, as a modifying agent of this reality. This study, therefore, will always be turned to a constitutional aspect, respecting the principles of economic order and the goal of reducing regional inequalities, which must influence the making off of a developing plan. At the end, it will try to demonstrate the juridical viability of such undertaking, tuned in jus-economical criteria. Another goal is related to the analysis of the natural gas industry, due the regulation of its transport has a major importance for national energetic integration, not only because this activity be characterized as a net industry, still under control of a natural monopoly, but also because the competitive or cooperative profile that should be priorized at the beginning of the economic planning for this activity (such as investment policies and its own rules that will submit private agents)

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In the middle of modern social changes produced by globalization and capitalism, several markets have changed. States have left the direct coordination of these markets (chiefly public utility sector in the form of monopolies), introducing regulation in order to promote competition. These changes have affected natural gas industry by promoting competition as a key factor to the development and the increase of firms in this market. The regulatory reform of natural gas industry ocurred in EUA and Europe Union and it has produced its first results. In Brazilian context, Constitutional Amendment nbr. 09 and Federal Law nbr. 9.478/97 ( Petroleum Law ) opened the natural gas market to a broad range of private economic agents and they finished the monopoly over the industry before managed by Petrobras. The new regulatory framework of Brazilian natural gas industry has designed competition as a central element to the new form of managment of business and contractual relationships of this industry. Among the regulatory instruments, open access regulation in natural gas pipelines is directed to promote competition. The questions arised about its implementation in Brazilian context are studied in the present work, in which it is discussed the constitutional rules and principles are to be applied to the open access regulation within the theme of statal regulation of economy present in constitutional economic order

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Natural gas, although basically composed by light hydrocarbons, also presents in its composition gaseous contaminants such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). Hydrogen sulfide, which commonly occurs in oil and gas exploration and production activities, besides being among the gases that are responsible by the acid rain and greenhouse effect, can also cause serious harm to health, leading even to death, and damages to oil and natural gas pipelines. Therefore, the removal of hydrogen sulfide will significantly reduce operational costs and will result in oil with best quality to be sent to refinery, thereby resulting in economical, environmental, and social benefits. These factors highlight the need for the development and improvement of hydrogen sulfide sequestrating agents to be used in the oil industry. Nowadays there are several procedures for hydrogen sulfide removal from natural gas used by the petroleum industry. However, they produce derivatives of amines that are harmful to the distillation towers, form insoluble precipitates that cause pipe clogging and produce wastes of high environmental impact. Therefore, the obtaining of a stable system, in inorganic or organic reaction media, that is able to remove hydrogen sulfide without forming by-products that affect the quality and costs of natural gas processing, transport and distribution is of great importance. In this context, the evaluation of the kinetics of H2S removal is a valuable procedure for the treatment of natural gas and disposal of the byproducts generated by the process. This evaluation was made in an absorption column packed with Raschig ring, where natural gas with H2S passes through a stagnant solution, being the contaminant absorbed by it. The content of H2S in natural gas in column output was monitored by an H2S analyzer. The comparison between the obtained curves and the study of the involved reactions have not only allowed to determine the efficiency and mass transfer controlling step of the involved processes but also make possible to effect a more detailed kinetic study and evaluate the commercial potential of each reagent

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Natural gas, although basically composed by light hydrocarbons, also presents contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). The H2S, which commonly occurs in oil and gas exploration and production activities, causes damages in oil and natural gas pipelines. Consequently, the removal of hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is essential to consider the better quality of the oil to be processed in the refinery, thus resulting in benefits in economic, environmental and social areas. All this facts demonstrate the need for the development and improvement in hydrogen sulfide scavengers. Currently, the oil industry uses several processes for hydrogen sulfide removal from natural gas. However, these processes produce amine derivatives which can cause damage in distillation towers, can cause clogging of pipelines by formation of insoluble precipitates, and also produce residues with great environmental impact. Therefore, it is of great importance the obtaining of a stable system, in inorganic or organic reaction media, able to remove hydrogen sulfide without formation of by-products that can affect the quality and cost of natural gas processing, transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer and kinetics of hydrogen removal, in this study it was used an absorption column packed with Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by the liquid phase. This absorption column was coupled with a H2S detection system, with interface with a computer. The data and the model equations were solved by the least squares method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride, copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low concentrations (»10 ppm). These solutions were used looking for the evaluation of the interference between absorption physical and chemical parameters, or even to get a better mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow. In this context, the evaluation of H2S removal arises as a valuable procedure for the treatment of natural gas and destination of process by-products. The study of the obtained absorption curves makes possible to determine the mass transfer predominant stage in the involved processes, the mass transfer volumetric coefficients, and the equilibrium concentrations. It was also performed a kinetic study. The obtained results showed that the H2S removal kinetics is greater for NaOH. Considering that the study was performed at low concentrations of chemical reagents, it was possible to check the effect of secondary reactions in the other chemicals, especially in the case of KMnO4, which shows that your by-product, MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to have good efficiency in H2S removal

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Many species have specialized to live in the most varied existing environments showing the remarkable adaptability of the microbial world the most diverse physicochemical conditions. Environments exposed to natural radiation and metals are scarce around the world, presenting a microbiota still unknown. With a total number estimated between 4 and 6 x 1030 microrganisms on earth, they constitute an enormous biological and genetic pool to be explored. Metagenomic approach independent of cultivation, provides a new form to access to the potential genomic environmental samples becoming a powerful tool for the elucidation of ecological functions, metabolic profiles, as well as to identify new biomolecules. In this context, the genetic material of environmental soil and water samples from Açude Boqueirao Parelhas-RN, under the influence of natural radiation and the presence of metals, was extracted, pirosequencing and the generated sequences were analyzed by bioinformatics programs (MG-RAST and STAMP). Taxonomic comparative profiles of both samples showed high abundance of Domain Bacteria, followed by a small portion attributable to Eucaryota Domains, Archaea and Viruses. Proteobacteria, Actinobacteria and Bacterioidetes phyla showed the greater dominance in both samples. Important genera and species associated with resistance to various stressors found in region were observed. Sequences related to oxidative and heat stress, DNA replication and repair, and resistance to toxic compounds were observed, suggesting a significant relationship between the microbiota and their metabolic profile, influenced by regional environmental variables. The results of this study add valuable and unpublished data on the composition of microbial communities in these regions

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The contamination of water bodies with toxic substances causes a decrease in water quality, representing a risk to public health. In this context, human activities are generally seen as the main sources of water degradation. However, elements found naturally in the environment can also compromise water quality. Thus, the Boqueirão‘s dam, located in the municipality of Parelhas (RN, Brazil), was chosen as area for the development of this study, as its geological region is rich in the emission of natural ionizing radiation that produces byproducts like lead and Radon. Moreover, the area has a strong human influence that enhances the risks of pollutant discharge in this body of water.Thus, the objectives of this study were centered (i) in the analysis of risk perception in the city of Parelhas (RN/Brasil) due to the use of the water from the Boqueirão Dam; and (ii) in the assessment of water quality in the Dam using methods that quantify, mainly, heavy metals and radiation levels, as well as these toxics potential of inducing mutations on genetic material. The analysis of risk perception showed that the population in the city of Parelhas can perceive a risk in using the water from the dam and that they can recognize factors that influence the water quality. Regarding the second objective, the set of data point to the contamination of the Dam by heavy metals, as well as levels of radioactive parcicles and Radon – also present in high concentrations in outdoor air and on soil. Thus, it is possible to infer that the population residing in this area is subjected to injuries caused by exposure to natural and anthropogenic contamination. Our findings corroborate with the perception of the population regarding the risks associated with the use of the Dam for several types of activities. It is expected that the information gathered in this study can substantiate activities and future researches in this semiarid region in the Rio Grande do Norte/Brazil. Also, that the set of data can enable a better understanding of the specific toxicological scenario of risk found for the population and the effect of the contamination for the biota, which aids the development of a future risk assessment and a consequent management of this local issue.

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The so-called "residential tourism" came to intensify the previous occupation of the coastal zones, characterized by traditional beach houses, and brought significant consequences for their spatial configuration, and especially for its scenic value of the landscape. Although there is the intention to regulate the activities of enterprising groups by some legal instruments to control the use and occupation of land, and to contain some negative effects, the actions of government are still inefficient in trying to follow the implications on the landscape from the accelerated growth of the real estate and touristic sectors. Supported in the speech of economic development and income generation, public managers prioritize areas to attract tourists to the detriment of preserving important physical attributes of the natural environment that contribute significantly to the quality of life. The result can be noticed in the use of natural elements as one of the major components in the land valorization, and in the immediate attraction of investors and enterprising. Therefore, the objective of this work is to contribute to the debate on the landscape preservation a little detailed thematic in view of their relevance in the current context - by indicating subsidies to the creation of a methodology for the evaluation and protection of coastal zones that may assist the government in creating new instruments, and better prepare it in control of the occupation of these areas. For such, was followed two ways to analysis: the indirect method and the direct method. The first is grounded in the evaluation of landscape attributes, which is based on the work of Raquel Tardin (2008) and Eduardo Cuesta, Encarnación Algarra and Isabel Pastor (2001). The second, based on the research of Leticia and Carlos Hardt (2010) and on the concepts of phenomenology - expressed by Antonio Christofoletti (1985) and Yi-Fu Tuan (1983) - considers the population perspective on the quality of the natural scenery. Developed through cartographic materials, photographic collections and quantitative tables, this dissertation utilized as a case study the beaches of Barra de Tabatinga and Camurupim, located in the city of Nísia Floresta/RN. Despite already being sighted spaces of advanced stage of landscape degradation in these locations, areas of remarkable scenic value can still be found, what reinforce the urgency in adopting preservationists actions. The absence of laws focused on the management and protection of the landscape singularities associated with the inefficiency of the government to invigilate the land occupation in coastal zones, encourage the excessive action of the real estate-tourism, and consequently make the government the main responsible for the environmental and landscape impacts in these areas - by its omission or by their connivance. Therefore, the legislation permeates this entire process and constitutes itself as the most effective way to guarantee the right to the landscape to present and future generations. Are also pointed some important considerations to build a methodology, especially concerning possibilities of improvements and adaptations of its applicability in each case

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The construction industry is one of the largest consumers of natural raw materials, and concrete is considered today the most used material wide. This accentuated consumption of natural resources has generated concern with the preservation of the environment, and has motivated various studies related to the use of resid ues, which can partially or entirely substitute, with satisfactory performance, some materials such as the aggregate, and in so doing, decrease the impact on the environment caused by the produced residues. Research has been done to better understand and improve the microstructure of concrete, as well as to understand the mechanism of corrosion in reinforced steel. In this context, this work was developed aiming at discovering the influence of the substitution of natural sand by artificial sand, with rega rd to mechanical resistance, microstructure, and durability. To obtain the electrochemical parameters, an adaptation was made to the galvanostatic electrochemical method to study the corrosion in reinforced steel. Concretes of categories 20 MPa and 40 MPa were produced, containing natural sand, and concretes of the same categories were produced with artificial sand substituting the natural sand, and with the addition of sodium nitrate and sodium chloride. Due to the use of rock dust reject (artificial sand), an evaluation was made of its environmental risk. The results indicate that the concretes of category 20 MPa present a better performance than the concrete made with natural sand, thus making it a viable substitute. For the category 40 MPa, the better performance is from the concrete containing natural sand. The adaptation of the galvanostatic electrochemical technique to the study of the corrosion of reinforced steel within concrete proved to be valid for obtaining electrochemical parameters with a high degree of reliability, considering the number of degrees of freedom