Caracterização microestrutural e elétrica de La(FexNi1-x)O3 sintetizado pelo método da gelatina

The present work deals with the synthesis of materials with perovskite structure with the intention of using them as cathodes in fuel cells SOFC type. The perovskite type materials were obtained by chemical synthesis method, using gelatin as the substituent of citric acid and ethylene glycol, and polymerizing acting as chelating agent. The materials were characterized by X-ray diffraction, thermal analysis, spectroscopy Fourier transform infrared, scanning electron microscopy with EDS, surface area determination by the BET method and Term Reduction Program, TPR. The compounds were also characterized by electrical conductivity for the purpose of observing the possible application of this material as a cathode for fuel cells, solid oxide SOFC. The method using gelatin and polymerizing chelating agent for the preparation of materials with the perovskite structure allows the synthesis of crystalline materials and homogeneous. The results demonstrate that the route adopted to obtain materials were effective. The distorted perovskite structure have obtained the type orthorhombic and rhombohedral; important for fuel cell cathodes. The presentation material properties required of a candidate cathode materials for fuel cells. XRD analysis contacted by the distortion of the structures of the synthesized materials. The analyzes show that the electrical conductivity obtained materials have the potential to act as a cell to the cathode of solid oxide fuel, allowing to infer an order of values for the electrical conductivities of perovskites where LaFeO3 < LaNiO3 < LaNi0,5Fe0,5O3. It can be concluded that the activity of these perovskites is due to the presence of structural defects generated that depend on the method of synthesis and the subsequent heat treatment

Preparação e caracterização de filmes cerâmicos para cátodos de células a combustível de óxido sólido

Alternative and clean energy generation research has been intensified in last decades. Among the alternatives, fuel cells are one of the most important. There are different types of fuel cells, among which stands out intermediate temperature solid oxide fuel cell (IT-SOFC) matter of the present work. For application as cathode on this type of devices, the ceramic Ba0.5Sr0.5C0.8Fe0.2O3-δ doped with rare earth ions (Nd, Sm) have been quite promising because they show good ionic conductivity and operate at relatively low temperatures (500 - 800°C). In this work, Ba0.5Sr0.5Co0.8Fe0.2O3-δ, (BaSr)0.5Sm0.5Co0.8Fe0.2O3-δ and (BaSr)0.5Nd0.5C0.8Fe0.2O3-δ were obtained by modified Pechini method, making use of gelatin as polymerizing agent. The powders were characterized by X-Ray Diffraction (XRD), Temperature Programmed Reduction (TPR) and Scanning Electron Microscopy (SEM). The perovskite phase was observed in all X-ray patterns for the materials Ba0.5Sr0.5C0.8Fe0.2O3-δ doped with rare earth ions (Nd, Sm). The SEM images showed that the materials have a characteristics porous, with very uniform pore distribution, which are favorable for application as cathodes. Subsequently, screen-printed assymmetrical cells were studied by impedance spectroscopy, to assess the kinetics of the cathode for the reduction reaction of oxygen. The best resistance to the specific area was found for the cathode BSSCF sintered at 1050 °C for 4 hours with around 0.15 Ω.cm2 at 750 °C as well as cathodes BSNCF and BSCF obtained resistances specific area of 0.2 and 0.73 Ω.cm2, respectively, for the same conditions. The polarization curves showed similar behavior to the best cathodes BSSCF and BSNCF, such combination of properties indicates that the film potentially depict good performance as IT-SOFC cathodes

Compósitos Portland-biopolímeros para cimentação de poços de petróleo

The oil production in mature areas can be improved by advanced recovery techniques. In special, steam injection reduces the viscosity of heavy oils, thus improving its flow to surrounding wells. On the other hand, the usually high temperatures and pressures involved in the process may lead to cement cracking, negatively affecting both the mechanical stability and zonal isolation provided by the cement sheath of the well. The addition of plastic materials to the cement is an alternative to prevent this scenario. Composite slurries consisting of Portland cement and a natural biopolymer were studied. Samples containing different contents of biopolymer dispersed in a Portland cement matrix were prepared and evaluated by mechanical and rheological tests in order to assess their behavior according to API (American Petroleum Institute) guidelines. FEM was also applied to map the stress distribution encountered by the cement at bottom bole. The slurries were prepared according to a factorial experiment plan by varying three parameters, i.e., cement age, contents of biopolymer and water-to-cement ratio. The results revealed that the addition of the biopolymer reduced the volume of free water and the setting time of the slurry. In addition, tensile strength, compressive strength and toughness improved by 30% comparing hardened composites to plain Portland slurries. FEM results suggested that the stresses developed at bottomhole may be 10 to 100 times higher than the strength of the cement as evaluated in the lab by unconfined mechanical testing. An alternative approach is proposed to adapt the testing methodology used to evaluate the mechanical behavior of oilwell cement slurries by simulating the confined conditions encountered at bottornhole

Modelagem analítica e experimental da filtração em meios porosos

Deep bed filtration occurs in several industrial and environmental processes like water filtration and soil contamination. In petroleum industry, deep bed filtration occurs near to injection wells during water injection, causing injectivity reduction. It also takes place during well drilling, sand production control, produced water disposal in aquifers, etc. The particle capture in porous media can be caused by different physical mechanisms (size exclusion, electrical forces, bridging, gravity, etc). A statistical model for filtration in porous media is proposed and analytical solutions for suspended and retained particles are derived. The model, which incorporates particle retention probability, is compared with the classical deep bed filtration model allowing a physical interpretation of the filtration coefficients. Comparison of the obtained analytical solutions for the proposed model with the classical model solutions allows concluding that the larger the particle capture probability, the larger the discrepancy between the proposed and the classical models

Estudo paramétrico da recuperação de petróleo pesado por aquecimento eletromagnético resistivo

Electrical resistive heating (ERH) is a thermal method used to improve oil recovery. It can increase oil rate and oil recovery due to temperature increase caused by electrical current passage through oil zone. ERH has some advantage compared with well-known thermal methods such as continuous steam flood, presenting low-water production. This method can be applied to reservoirs with different characteristics and initial reservoir conditions. Commercial software was used to test several cases using a semi-synthetic homogeneous reservoir with some characteristics as found in northeast Brazilian basins. It was realized a sensitivity analysis of some reservoir parameters, such as: oil zone, aquifer presence, gas cap presence and oil saturation on oil recovery and energy consumption. Then it was tested several cases studying the electrical variables considered more important in the process, such as: voltage, electrical configurations and electrodes positions. Energy optimization by electrodes voltage levels changes and electrical settings modify the intensity and the electrical current distribution in oil zone and, consequently, their influences in reservoir temperature reached at some regions. Results show which reservoir parameters were significant in order to improve oil recovery and energy requirement in for each reservoir. Most significant parameters on oil recovery and electrical energy delivered were oil thickness, presence of aquifer, presence of gas cap, voltage, electrical configuration and electrodes positions. Factors such as: connate water, water salinity and relative permeability to water at irreducible oil saturation had low influence on oil recovery but had some influence in energy requirements. It was possible to optimize energy consumption and oil recovery by electrical variables. Energy requirements can decrease by changing electrodes voltages during the process. This application can be extended to heavy oil reservoirs of high depth, such as offshore fields, where nowadays it is not applicable any conventional thermal process such as steam flooding

Estudo do comportamento de pastas compósitas cimento/sílica/poliuretana para poços de petróleo HPHT

Os poços HPHT atravessam zonas anormalmente pressurizadas e com altos gradientes de temperatura. Esses poços apresentam elevadas concentrações de tensões produzidas pelas operações de perfuração e fraturamento hidráulico, flutuações da pressão e temperatura, forças dinâmicas geradas durante a perfuração, formações inconsolidadas, entre outros aspectos, podendo resultar em falhas mecânicas na bainha de cimento. Tais falhas comprometem a estabilidade mecânica do poço e o isolamento das zonas produtoras de óleos e/ou gás. Para que operações corretivas não se façam necessárias, é preciso adequar as pastas às condições de cada poço. Sistemas de pastas de cimento para poços HPHT requerem um bom controle de suas propriedades termo-mecânicas. Visto que a temperaturas superiores a 110 oC (230 oF) o cimento, após alcançar um valor máximo de resistência, inicia um processo de perda de resistência (retrogressão). Para prevenir esse efeito substitui-se parcialmente o cimento Portland por sílica com objetivo de incrementar a reação pozolânica. Esta reação modifica a trajetória do processo natural de hidratação do cimento, o gel de silicato de cálcio hidratado (C-S-H) se converte em várias outras fases com maior resistência. Polímeros também são adicionados para proporcionar maior flexibilidade e agir como barreira à propagação de trincas desenvolvidas sob tensão. O presente trabalho teve como objetivo estudar o comportamento do sistema cimento/sílica/polímero quando submetido às condições de alta temperatura e alta pressão. Foram formuladas pastas de cimento puro, pastas contendo 40 % BWOC de sílica flour e pastas com diferentes concentrações de poliuretana (5 % a 25 %) e 40 % BWOC de sílica flour. O peso específico das pastas foi fixado em 1,87 g/cm3 (15,6 lb/gal). Os resultados demonstram que as resistências da pasta contendo 40% de sílica e das com adição de polímero foram muito superiores a da pasta de cimento puro, não ocorrendo o efeito da retrogressão. As pastas com polímero apresentaram um crescente aumento da tenacidade com o aumento da concentração da mesma, sendo assim capaz de suportar as tensões. Além de se manterem estáveis termicamente acima de 180 ºC. O sistema também apresentou excelentes resultados de filtrado, reologia, água livre, estabilidade e permeabilidade. Sendo assim, o mesmo mostrou ser aplicável a poços HPHT

Efeito da adição de cargas minerais leves na resistência mecânica de grautes para cimentação de poços offshore

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

Análise do vetor de impedância bioelétrico na avaliação da suplementação de zinco em crianças prepuberais e sadias

Conselho Nacional de Desenvolvimento Científico e Tecnológico

A violência policial militar e o contexto da formação profissional: um estudo sobre a relação entre violência e educação no espaço da Polícia Militar no Rio Grande do Norte

Cette dissertation a pour thème la formation de la police militaire, dans le contexte de l'insertion dans le nouveau programme scolaire national Matrix (MCN) institutionnalisée pour la formation à la securité publique au Ministère de La Justice (MJ) de La Secrétariat Nationale pour La Sécurité Publique, à partir de 2003. Ce normalisateur document devrait être utilisé comme un paramètre de l'organisation de divers organismes éducatifs dans le domaine de la sécurité nationale. Son institutionnalisation pose elle-même comme étant composé comme um ensemble politiques orientées à formation des professionnels de la sécurité publique qui est en cours de développement au Brésil depuis. En particulier, il a été trouvé dans locus, par le méthode de l observation participant à um cours de formation pour les soldats (CFSD) de La Police Militaire de Rio Grande do Norte (PMRN), en Octobre et Novembre 2007, Centre pour Formation et Perfectionner de PMRN ainsi que par le biais d entrentiens avec la police militaire (PM), changé de la formation, comme nous l avons mise en oeuvre de la l'insertion de la MCN, dans le contexte de l analyse de la violence dans la police militaire de Rio Grande do Norte (RN). Les résultats de l'étude montrent que, en général, le MCN est étant insérés dans CFSD partir de 2004, cette opération fait sentir graduellement dans le visage de certains résistence mennée par une sous-culture (militaires) qui se réinvente dans l'établissement officier de police, résistant aux nouvelles exigences sociales. En outre, il a été noté également que les deux mythes sont limitées à l'imagination, la police brésilienne: le militarisme exarcebé et le baccalauréat em droit, qui contribuent considérablement à la barrière dans la construction d'une police militaire plus identifié à l'activité professionnelle dédié à la sécurité publique, que de la sécurité nationale. L'élargissement de la compréhension de la violence, en particulier, la police militaire, le travail rend l'utilisation des références théoriques qui cherchent à embrasser la diversité et la spécificité qui guident le processus de formation pour les opérateurs de la sécurité publique, en particulier, en essayant de comprendre comment ils sont construits les références théoriques pour les formateurs et les stagiaires dans une relation dialectique et comment ce contexte mai influencer les attitudes conceptuelles, d'attitudes et de procédure dans l'exercice de la police militaire, que dans le contexte nouveau de l'Etat de droit démocratique, a réellement vécu en contradiction avec les fantômes du temps exception, réalisée pendant la dictature (1964-1985), non loin de l imaginaire social, et ni la police ni les militaires, une institution fortement stigmatisées depuis

Indústria cultural e forró eletrônico no Rio Grande do Norte

The present study aimed to understand how and to what extent the electronic forró, currently hegemonic in the music market in the state of Rio Grande do Norte, establishes and maintains relations of domination in the social contexts in which it is produced, transmitted and received. Based, in significant form-content, on the writings of the first generation of theorists of the so-called Frankfurt School (Critical Theory), particularly with Theodor W. Adorno, and systematically using the contributions of the Cultural Studies (from the Centre for Contemporary Cultural Studies of Birmingham) and of the sociology of Pierre Bourdieu, this study aimed to perform, in the fertile intersection of these references, a critical possibility of interpretation of the electronic forró predominantly spread in the state of Rio Grande do Norte. To this end, aiming at a better apprehension of the so-called capital circuits/culture circuits , this study resulted from a qualitative investment of research, based on structured interviews with musicians, entrepreneurs of the sector and music consumers, as well as on the analysis of the themes contained in the official discography of the electronic forró band called Garota Safada (Shameless Girl). As a general empirical conclusion, it was possible to infer that far from the significant presence of domination or mere prevalence of oppositions, there is a relational pluralism of forms of domination and ways of resistances present in the production and consumption of electronic forró, regardless of gender, age, income, education or place of residence. However, the artifices of the cultural industry has been shown to be efficient: from large-scale businessmen to small producers enabled by the so-called open markets . The currentness of the concept of cultural industry is based on the idea that its products are offered systematically (the systematic insistence of everything to everyone) and on the notion that its production primarily meets the administrative criteria of control over the effects on the receiver (capacity of prescription of desires). Thus, the Adornian reflection on the pseudo-individualization leads to the inference that even in some of the most apparent ways of negotiation and/or refusal regarding the consumption of forró, certain behaviors of the cultural industry still prevail both in the very (re)interpretation of the forró and in the choice of other music genres also standardized, rationalized and massified. Therefore, despite the absence of cause-effect relation and the recognition of the popular capacity of re-elaboration and contestation of the media consumption, some world views prevailing in relation to the electronic forró establish or, at least, support some hegemonic ideologies, especially those concerning the life style, consumption and genre relations (fun by all means). Therefore, due the massification of certain songs, some ways of dissemination of values, beliefs and feelings are potentially experienced from the electronic forró. So, it is presumable that in the current advance of the process of semiformation (Halbbildung), the habitus of a part of the youth from the state of Rio Grande do Norte reinforces and is reinforced by the centrality of the trinomial fun, love and sex present in the songs, emphasized in some constructive practices of sense and in certain flows of social significance

A transversalidade no currículo do ensino fundamental: as questões ambientais em foco

This thesis is the result of an investigation about the transversality of the environmental issues into the daily curriculum of High Schools (from first to eighth grade). The research field was the county of Santo Antonio de Jesus in the state of Bahia, Brazil. The investigation is related with the challenge that the present model of social development and organization has put to the school institution: to bring the regular discussion about Environmental Education (EE) to the school s daily life. Facing the complexity of the socio-environmental issues and the basic functions of Education, the object of study was restricted to the identification of the challenges and paradoxes of the EE inside the curriculum organization of Politic-Pedagogic Project of the schools and the teachers daily practices. About the methodology, we adopted different references for the qualitative research: sociology, history, economy, and education. As for the investigative procedures about the teacher s practices, we related the school s daily practices to the context of the community. We also adopted several investigative procedures, such as questionnaires, interviews, observations and formative intervention. The theoretical basis was organized based on references to curriculum organization, environmental culture, teacher education and also considering the pillars of a capitalistic system that is based on consumerism and that generates social exclusion. At the initial considerations, we contextualized the contemporary environmental issues in an attempt to interpret the conditions of the EE transversality into the school s daily practices, which are still oriented to the traditional Cartesian Education. Based on the collected data, we found the reasons for the teachers dilemma and reluctances to the insertion of the environmental issues into the organization of the work plan and into the management of a school. Nevertheless, the results also signed promising possibilities to the EE tranversality, in case the curriculum of the school could be more sensible towards the cultural and social-economical issues of a community. We especially questioned The National Curriculum Parameter s (PCN), which is considered highly insufficient to inform the teachers about the environmental issues, facing the actual local conditions of social and pedagogic work. The final considerations showed the role and the importance of this research as one strategy to organize the curriculum education into the perspective of the transversality of environmental issues inside the education of both teacher and student

Representação social sobre educação inclusiva por professores de Cruzeiro do Sul - Acre

Nowadays the discussion about providing a quality education for all students is more and more recurrent, including for those who have special educational necessities. The discussion increases regarding that it is not enough to include these students in the regular school, but also to provide conditions of learning and development. This requirement implies changes in the educational system, as well as in the teachers‟ everyday; and these changes manifest themselves through the complexity of the functions which are assigned to the teachers and the school. The news that are generated from the perspective of the inclusive education asks for new formative models for teacher‟s performance, once he tries to (re)build knowledge, knowings and doings among troubles and conflicts as a way to decrease the impact caused by the necessary transformations. This research approached this context in order to understand the social representation about the inclusive education from teachers who work in the regular public school system in the Municipality of Cruzeiro do Sul, State of Acre. To approach the symbolic content, we elected the Multiple Classification Procedure (MCP) as the methodological approach. For that, it was necessary to apply the Technique of Free-Association of Words (TFAW) to 60 participants what provided data to the first step of the chosen methodological procedure. The criterion of choice of the participants took into account if they dealt with student who has special educational necessities and with public schools. Later, we applied MCP to 50 teachers from specialized course in inclusive education subgroup 01 and 30 teachers who has no specialized formation subgroup 02. The collected data from this step was examined through multidimensional and content analysis for a better understanding of their symbolic dimensions. The results from the multidimensional analysis showed that the subject inclusive education‟ for subgroup 01 involved the following facets: circulating discourses that meant the naming of the characteristics that teachers think indispensable to inclusive education; teachers in relation to the inclusive practice that was focused on the relation between teaching and included student, and repercussion to the student that showed the advantages that the inclusive education provided to the student who has special educational necessities. Subgroup 02 dealt with the following facets: characteristics of the included student that approached teachers‟ view on this student; negative aspects that regarded the naming of the obstacles in the achievement of inclusive education; and teacher‟s relations to the inclusive education that approach professional, affective, and formative elements. The content analysis revealed four categories: disagreeing concepts; conception of inclusive education; dimension of the teacher‟s inclusive doing, and difficulties and resistance to carry out the inclusion of a student who has special educational necessities in the regularschool. Both analyses multidimensional and content one showed that the constitution of elements in a social representation of inclusive education was a mixture formed by the characteristics of this sort of education and the school integration, materialized on the figure of the different‟ student. The representational field of the subject inclusive education‟ was associated to the social representation of the student who has special educational necessities, making clear the deficiency/ difference, and causing the difficulty of the teachers in achieving what they say about the phenomenon

Anayde Beiriz e a escrita de si: (Educação, história e relações de gênero)

Le thème de cette dissertation est l Histoire de l éducation de la femme. Une analyse des pratiques culturelles de la professeur Anayde da Costa Beiriz (1905-1930), dans le contexte paraibanais du début du XXe siècle, est proposée. Le référentiel théoricométhodologique de l Histoire Culturelle est utilisé, pour aller contre l histoire passée sous silence dans le canon traditionnel. Basée sur le concept de représentation (Chartier, 1990), rompant avec les anciennes idées de sens intrinsèque, absolu, unique, liée aux pratiques complexes, multiples et différenciées, qui construisent le monde comme représentation. Basée aussi sur le concept de configuration (Elias, 1980), en comprenant que apparemment individu et société sont deux objets qui existent indépendamment, mais en vérité, se rapportent à deux niveaux inséparables du monde social, sont unis par des liens d interdépendance. Un dialogue est recherché entre le passé et le présent et les différentes dimensions: historique, sociale, politique et culturelle vécues par la professeur Anayde Beiriz. Pour obtenir des informations sur ses pratiques culturelles, une recherche des marques de cette histoire dans de multiples sources est effectuée: dans la bibliographie disponible parmi les domaines de la littérature, de l histoire, dês sciences sociales et de l éducation; dans des archives de l Institut Historique et Géographique de la Paraiba et de Natal; dans les Bibliothèques de l Université Fédérale de la Paraiba et du Rio Grande do Norte et chez des bouquinistes. L inventaire comprend: des périodiques, la législation en vigueur, des écrits de contemporains, dês témoignages oraux de parents, des lettres et des photos. On comprend de cette façon, que l idée d éplucher au travers de cette étude, des aspects qui n ont pas encore été vus et rappelés, peut non seulement répondre à nos doutes, mais, peut à partir de la réflexion qui se fait, se traduire par une nouvelle compréhension de cette histoire. En conclusion, des significations multiples sont contenues dans le processus d insertion de la femme dans l éducation à partir des Écoles Normales, qui englobent les relations de genre, l histoire du pouvoir, de la morale, de surpassement, des luttes et insatisfactions. On perçoit l héritage de résistances et de conquêtes. Cela a été sous l inspiration des airs de la modernité avec la Belle Époque, en répercutant dans le monde et aussi dans la Parahyba du Nord, que s est concrétisée la formation sociale de la professeur Anayde Beiriz et des femmes de son temps. L analyse de l écriture de soi confirme le discours normatif du contrôle moral social, le joug et les préjugés soufferts par Anayde Beiriz et l éducation différencié de genre qui ont déterminé ses habitudes et coutumes. C est-àdire, pour la femme, la permanence dans l espace privé, la retenue, l anoblissement des tâches ménagères et de la maternité comme sa plus haute aspiration, le support moral de la famille, la préservation de la tradition et la perpétuation des règles religieuses

Mestres e aprendiz: perambulando por ilhas de resistência

Monoculture of mind This idea, presented by Vandana Shiva, reflects the phase that we have experienced in the world: a notion of civilization that, since many decades, characterized by a technocratic big trend, has been shown as dominant and hegemonic. Based on a thinking and acting, felling and whishing standardization, this wave ends implying in what can be called of humanity‟s crisis at civilizational process. Destruction of simpler and more harmonious lifestyles with nature, human relations increasingly distant, values embrittlement, as respect, goodness and love, are some consequences of that behavioral homogenization. In the other hand, appears an archipelago of cultural and cognitive resistance against this devastating wave. Edgar Morin and Ceiça Almeida refer to this archipelago as a South Thought , what is not just a geographic question. Report, therefore, to some places, peoples, island that keep ancient costumes and knowledge, orally transmitted, for instance, from elders to younger, or vice versa, in an almost constant flow. Particular ways of experiencing the world around themselves, the men, animals, plants, rocks, or even not alive beings, masters or enchanted, spiritual guides. Next to a logic of sensitive, as Claude Levi-Strauss proposes, this reading, which is a more attentive, observer and wiser posture of surroundings, is based on touching, smelling, eating, seeing, and, I would add, felling. In light of this, I try to expatiate about certain experiences that I had the pleasure of living in some of these islands of resistance. Talks, perceptions, observations, sensations Stories, prose, poetries, music, photos, graphics Whatever could serve to portray even a bit of the reflections and forms to understand (ourselves) and produce knowledge, such as from a formation/Education to life, was well used at this ethnographic work. Space to the subjectivity and emotions I had, have, and will have a lot Everything for the dear reader may fell traveling around the world of tradition, resistance

Avaliação do concreto de cimento portland com resíduo da produção de scheelita em substituição ao agregado miúdo

From the 70`s, with the publication of the Manifesto for Environment UN Conference, held in Stockholm, in Sweden (1972), defend and improve the environment became part of our daily lives. Thus, several studies have emerged in several segments in order to reuse the waste. Some examples of waste incorporated in portland cement concrete are: rice husk ash, bagasse ash of cane sugar, powder-stone, microsilica, tire rubber, among others. This research used the residue of the mining industry Scheelite, to evaluate the incorporation of the residue composition of Portland cement concrete, replacing the natural sand. The percentage of residue were incorporated from 0% to 100%, with a variation of 10%, 11 being produced concrete mix in the ratio 1:2:3:0.60, by mass. We evaluated the following characteristics of concrete: slump test, compressive strength, tensile strength by diametral compression, water absorption, porosity and density, based on the ABNT, through tests performed in the Laboratory of Civil Construction, UFRN. The trace with the addition of 60% scheelite residue was obtained which better performance. Therefore, the use of the waste from the production of Scheelite is feasible due to the durability parameters (water absorption and porosity), sustainability, and the good results of the resistance of the concrete