42 resultados para Energia eólica : Aspectos econômicos


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Artisanal fishing is one of the important economic activities of Rio Grande do Norte (RN), becoming the main form of survival and income for many families. The southern coast of RN has strong fishing tradition, both in exploitation of fish as in the collection of mollusks on the banks of Guaraíra Lagoon (APA Bonfim-Guaraíra). In recent years, fishing communities have become more vulnerable to outside influences, since the socio-economic and environmental changes are exposed. These changes require adjustments to the fishermen to different environmental conditions, as the social and natural systems are driven by reorganization and upgrading processes. The living conditions in fishing communities are objective and necessary in different ways, according to a selection that is cultural, so adaptable. This study has the general objective to analyze the main environmental changes in fishing communities, based on the understanding of fishermen and mollusk fisherwomen about this problem. The specific objectives searched to: describe the socioeconomic profile, prospects and difficulties of fishermen and mollusk fisherwomen; investigate the major social and environmental changes in the fishing communities of Patané and Camocim (Arez/RN). The methodology was qualitative-quantitative with the techniques of observation in the field and open and semistructured interviews applied to representatives of Cologne fishing, fishermen and mollusk fisherwomen. Between the months of January to July 2014 were applied semistructured interviews with 41 interlocutors in Patané and 23 of Camocim; totaling 64 people. The results indicated that the interlocutors are aged 40 to 60 years; have only completed elementary school level; are married and have children; survive on less than a minimum wage income and they are not receiving employment insurance. The case study also revealed that the socioeconomic and environmental problems reflected in changes in reproduction, organization and social division of labor, which generates adaptive changes of families to external influences, resulting directly from other economic activities and market pressure and indirectly from tourism. Therefore, adaptations to changes scenario presented as favorable to economic aspects and unfavorable to the social and environmental aspects. In short, the fishery develops on technical, bureaucratic and financial obstacles, in the everyday needs of men and women is the determining factor in willingness to continue exercising fishing and shell fishing on Guaraíra Lagoon, space representing relations social, practices and customs transmitted in the course of local history through social memory of the oldest to the youngest.

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The constant necessity for new sources of renewable energy is increasingly promoting the increase of investments in this area. Among other sources, the wind power has been becoming prominent. It is important to promote the search for the improvement of the technologies involved in the topologies of the wind turbines, seeking for alternatives which enhance the gotten performance, despite the irregularity of the wind speed. This study presents a new system for speed control, in this case applied to the wind turbines - the Electromagnetic Frequency Regulator (EFR). One of the most used devices in some topologies is the mechanical gearboxes which, along with a short service life, often represent sources of noise and defects. The EFR does not need these transmission boxes, representing a technological advancement, using for that an adapted induction machine, in which the stator becomes mobile, supportive to the axis of the turbine. In the topology used in this study, the EFR also allows us to leave out the usage of the eletronic converters to establish the coupling between the generator and the electrical grid. It also the reason why it provides the possibility of obtaining the generation in alternating current, with constant voltage and frequency, where there is no electrical grid. Responsable for the mechanical speed control of the generator, the EFR can be useful in other transmission systems in which the mechanical speed control output is the objective. In addition, the EFR operates through the combination of two inputs, a mechanical and other electrical. It multiplies the possibilities of application because it is able to synergistic coupling between different arrays of energy, and, for such reasons, it enables the various sources of energy involved to be uncoupled from the network, being the synchronous generator responsible for the system connection with the electrical grid, simplifying the control strategies on the power injected in it. Experimental and simulation results are presented through this study, about a wind turbine, validating the proposal related to the efficience in the speed control of the system for different wind conditions.

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The use of energy from renewable sources is increasingly demanded by society, especially aeolian - whose raw material is wind. Investments in wind power have become significant in Brazil with emphasis on the Northeast and in particular the Rio Grande do Norte state. According to the Empresa de Pesquisa Energética (Energy Research Company) (2012 ) , investments in the state grew significantly since 2002 with a total accumulated power, by 2013, of approximately 3,400 MW . Even with the early experiences of exploitation of wind energy in 2002, it is still considered new and requires further study referring to the likely changes in the environment and society. In this case, it is of growing and urgent importance to deeply study the wind still in the survey phase of the project, ie , at the beginning of decision making on the most feasible to implement these parks site. Given the above, the question is: from a technical and environmental analysis, how to identify viable areas to install Aeolian parks, taking into account the factors of the environmental dynamics that are relevant to minimize the negative results to the environment and the society? Thus, this study conducted a study on technical and environmental feasibility, proposing a methodology of exploration of feasible wind farms in coastal areas. The study area was a fragment of the northern coast of Rio Grande do Norte and its natural landscape units were identified through the environmental characterization of the area, as well as it was elaborated the map of the land cover, restriction homes and urban areas and Permanent Preservation Areas - PPAs. The environmental fragility was subdivided in the fragility of the natural dynamic, mapped through relief, soils and geology of natural units, and the fragility of the ecosystem, originated by the land cover map. In addition to these maps, it was generated the wind resource for an area from a height of 50 and 100 meters. The intersection between the fragility maps, PPAs and Restriction of homes superimposed on maps of wind potential, provided the map of feasibility of Aeolian parks, resulting in the most favorable areas for its facilities in a technical and environmental point of view. From this study, the entrepreneur can evaluate whether or not to proceed with the studies in this area and especially decrease potential conflicts with society.

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Such work aims to analyze aspects of the lives of adolescents, authors of Infraction, after completion of the Socio-Educational Measures in Half Open (Probation - LA and Services to the Community - PSC) in the city of Natal / RN in 2010. Thus, it become necessary to point out and consider the socio-historical determinations that permeate the lives of these young men, estimating the economic, social, political and historical aspects. We understand that these individuals experience numerous expressions of Social Issues, such as lack of opportunities, violence, unemployment, among others. In the reduction context of the State actions for the social, and investments negligible in public policies. Thus, the research aimed to identify such determinations in the lives of adolescents, young people today, and aimed to know these adolescents and analyze the family situation, socio-economic and political these, after completion of educational measures; and to evaluate the inclusion in school life and in the labor market. Therefore, we used as a methodological way the qualiquantitative research, using the procedure of 4 (four) semi-structured interviews, 9 (nine) analysis processes by configuring so documentary research, through the analysis of reports, processes and monitoring documents. The universe of analysis went adolescents who fulfilled socio-educational measures in liberty in the city of Natal / RN. The sample consisted of nine (9) young, that we follow during the mandatory curricular training, in the period of graduation in Social Work at the Federal University of Rio Grande do Norte, in 2010. The time frame of the research took place between 2010 - 2014. The results of this study indicate that the solution to problems of violence is not the reduction of criminal majority. It is necessary to take actions in ensuring rights and allow other living conditions to the children and adolescents, because, in fact, in the society there is a tendency to regression of rights. We learn that, despite all the difficulties, as: low education, access to the labor market, low income, among others, young people interviewed understand the Socio-Educational Measures such as a watershed in their lives, because, they do not practice more illicit acts, they seek a better life, they have dreams and plans for the future, and they continue writing their histories.

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Such work aims to analyze aspects of the lives of adolescents, authors of Infraction, after completion of the Socio-Educational Measures in Half Open (Probation - LA and Services to the Community - PSC) in the city of Natal / RN in 2010. Thus, it become necessary to point out and consider the socio-historical determinations that permeate the lives of these young men, estimating the economic, social, political and historical aspects. We understand that these individuals experience numerous expressions of Social Issues, such as lack of opportunities, violence, unemployment, among others. In the reduction context of the State actions for the social, and investments negligible in public policies. Thus, the research aimed to identify such determinations in the lives of adolescents, young people today, and aimed to know these adolescents and analyze the family situation, socio-economic and political these, after completion of educational measures; and to evaluate the inclusion in school life and in the labor market. Therefore, we used as a methodological way the qualiquantitative research, using the procedure of 4 (four) semi-structured interviews, 9 (nine) analysis processes by configuring so documentary research, through the analysis of reports, processes and monitoring documents. The universe of analysis went adolescents who fulfilled socio-educational measures in liberty in the city of Natal / RN. The sample consisted of nine (9) young, that we follow during the mandatory curricular training, in the period of graduation in Social Work at the Federal University of Rio Grande do Norte, in 2010. The time frame of the research took place between 2010 - 2014. The results of this study indicate that the solution to problems of violence is not the reduction of criminal majority. It is necessary to take actions in ensuring rights and allow other living conditions to the children and adolescents, because, in fact, in the society there is a tendency to regression of rights. We learn that, despite all the difficulties, as: low education, access to the labor market, low income, among others, young people interviewed understand the Socio-Educational Measures such as a watershed in their lives, because, they do not practice more illicit acts, they seek a better life, they have dreams and plans for the future, and they continue writing their histories.

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The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.

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The farm’s rural dwellings of creation from the Seridó Potiguar microregion, built in the nineteenth century, became a reference by its vernacular character, i.e. these buildings, besides having recognized relevance to the identity of the region, they are adapted to the conditions of the place in many aspects (economic, cultural, construction, physical, et.) and consist in protective spaces in relation to hostile characteristics of Seridó’s climate. Considering the above premise, the following question arises: What characteristics of the nineteenth century Seridó Potiguar’s cattle farms are crucial for them to be a protective space in relation to the semiarid climate? In order to answer the question, this research aim to identify which particularities of the Seridó’s farmhouses that contribute to adaptability in these buildings to semiarid climate, as protection environments; and contribute to the stock valuation of the architectural heritage concerned. Therefore, procedures were adopted divided into two stages. Were first identified the recurring characteristics in the studied buildings, through typological study performed from existing inventories (DINIZ, 2008; FEIJÓ, 2002; IPHAN, 2012). To define the type it worked up with the concept that merges Durand’s analytical typology that identifies the similarities and differences to classify buildings, having the character of historical survey and architectural documentation, with the definition proposed by Argan (1963) that the type is not defined a priory, but the deduction from a number of illustrative cases which have formal and functional similarity with each other. Then worked up in a sample of five different types with each other, defined by the possibility of access to the interior of the houses, proximity to other copies, good state of conservation and preservation. The contemplated farms were: Pitombeiras, Agenus e Garrotes in Acari’s town, and the municipality of Caicó, Palma and Penedo. The second stage consists of the architectural survey, photographic record, digital three-dimensional modeling (aiming to expand the existing documentation and registration) and thermal monitoring over approximately a representative day in five farmhouses, relating the thermal performance of the houses with their individual characteristics. The selected variables for analysis monitoring are based on the thermal comfort adaptive model (SPAGNOLO and DE DEAR, 2003 apud NEGREIROS, 2010). The characteristics of the houses were analyzed as meeting the passive thermal conditioning strategies recommended by NBR 15220 (ABNT, 2005), for the bioclimatic zone 7 where the municipalities of Caicó and Acari are located. The house’s analysis of the operating temperatures revealed that 90% of the times of day the environments are within the comfort range. The farmhouses, which had a higher degree of compliance with recommended bioclimatic strategies, had the best thermal performance. In environments (usually the kitchen and rooms with low ceiling heights, exposed to west radiation) which still had discomfort hours, the thermal comfort can be reached with air movement approximately 1,0 m/s.

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With the heavy use of bearings in various segments of the industry, there are a large number of necessary interruptions in industrial processes to perform maintenance on these devices, with the case study wind turbines. The growth of the wind energy sector, encouraged to conduct research that helps to solve this problem. To contribute to predictive maintenance has been carried out a signal analysis using techniques which allow detection and location of the problem in order to prevent accidents caused and losses due to unexpected equipment failures, whereas low system rotation complicates the detection of the failure. To work around this problem, there was the indication of standard signals for defects in the bearings, making diagnosis of possible failures. With this diagnosis can be performed predictive maintenance, identifying the failure of the system that were tested, such as the introduction of grains of sand in the bearing, wear on the outer race of the bearing and bearing rust. By processing signals it is possible to construct graphs developing a mapping of defects by different peaks in the frequency band.

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CAMPOS,Maria da Luz Góis; ANEZ,Miguel Eduar- do Moreno; CARÍCIO,Marcelo Rique. Estratégias de Competitividade Industrial em Empresas Cooperativas:O caso COMTERN. In:ENCONTRO NACIONAL DE ENGENHARIA DE PRODUÇÃO, 23, 2003, Minas Gerais. Anais...Ouro Petro: ADEPRO, 2003. p. 1-8.

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The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

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The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades

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A proposal for a global analysis of sustainability in projects related in oil facilities is presented. By considering economic, environmental and social aspects in the early stages of design, the suggested method is more comprehensive and can be used to complement the analysis commonly applied in the petroleum industry, such as: Study of Technical and Economic Feasibility; Environmental Impact Assessment and Risk Analysis. Several authors, associations, certification bodies and oil companies suggest different approaches to study sustainability in some specific activities (or industries). In this study, a checklist of significant sustainability aspects for the oil industry (surface facilities) was assembled. In addition, a matrix was developed to assess the sustainability items relevant to these projects. In this work, the checklist interacts with the matrix to perform a "Preliminary Analysis of Sustainability of the Enterprise" (APSE). This method allows the identification of aspects that contribute significantly to global sustainability. From this analysis, which includes economic, social and environmental aspects, is built a report that is used to analyze qualitatively and quantitatively the impact of the sustainability aspects of the project. In this analysis are identified items that strongly influence the economic, social or environmental aspects and evaluated alternatives that can increase the overall sustainability of the project. Finally, the alternatives that can be used to indicate the most sustainable option are identified. This method was applied in a project (design) of a small offshore platform. This case study shows how the APSE can contribute to the identification of sustainability initiatives for the enterprise. The results showed that relevant aspects can contribute decisively to global sustainability. Finally, it was observed that the proposed method can contribute to increased rates of sustainability, even after application of analysis commonly used in these projects