Utilização de nanosílica como aditivo estendedor para pastas cimentantes de baixa densidade destinadas à cimentação de poços petrolíferos

Cementing operations are conducted at different times of the well s life and they have high importance, because the functions are fundamental to keep good properties during a long life of the well, such as, maintain the mechanical stability of the well, to promote the isolation hydraulic and support the tubing. In some situations, the rocky zones have low fractures pressures and require the use of lightweight slurries to prevent the hydrostatic pressure in the formation is greater than the pressure of fracture. There are three ways to reduce the density of cement slurries: exterders water additives, microspheres and foamed slurries. The most used extender water additive is sodium bentonite, which is a clay with a good capacity of water absorption and expansion of its volume, the main disadvantage of this additive is the reduction of the strength. Currently, the use of nanoscale particles has received special attention, mainly because they get new functionalities. Following this trend, this paper aims to use a colloidal solution of nano-silica as an exterders water additives for use in oil wells. Slurries were designed with fixed 13lb/gal density and concentration of nano silica 0.1 gpc; 0.4 gpc; 0.7 and 1gpc, the influence of nano-silica was studied at these levels in isolation and combined varying concentrations of CaCl2,. Tests including rheology, stability, strength, thickening time, porosity and permeability. Besides the API tests, microstructural characterizations were performed after 28 days of the slurries, X-ray diffraction (XRD) and scanning electron microscopy (SEM)

Formulação e caracterização de pastas espumadas por incorporação de ar e estabilizantes minerais

Cementing operations may occur at various stages of the life cycle of an oil well since its construction until its definitive abandonment. There are some situations in which the interest zones are depleted or have low fracture pressure. In such cases, the adoption of lowdensity cement slurries is an efficient solution. To this end, there are basically three ways to reduce the density of cement slurries: using microspheres, water extending additives or foamed cement. The objective of this study is to formulate, to study and to characterize lowdensity foamed cement, using an air entrainment surfactant with vermiculite or diatomite as water extenders and stabilizers. The methodology consists on preparation and evaluation of the slurries under the American Petroleum Institute (API) and the Brazilian Association of Technical Standards (ABNT) guidelines. Based on calculated densities between 13 and 15 ppg (1.559 and 1.799 g/cm3), the slurries were prepared with fixed surfactant concentration, varying the concentrations of vermiculite and diatomite and were compared with the base slurries. The results of plastic viscosity, yield point and gel strength and the compressive strength for 24 h showed that the slurries presented suitable rheology and mechanical strength for cementing operations in oil wells, and had their densities reduced between 8.40 and 11.89 ppg (1.007 and 1.426 g/cm3). The conclusion is that is possible, under atmospheric conditions, to obtain light weighted foamed cement slurries with satisfactory rheological and mechanical properties by means of air entrainment and mineral additions with extenders and stabilizers effects. The slurries have great potential for cementing operations; applicability in deep wells, in low fracture gradient formations and in depleted zones and bring cost savings by reducing the cementing consumption

Mutagênese induzida por flavonóides presentes do decocto das cascas da aroeira (Schinus terebinthifolius, Raddi)

The decoction of Brazilian pepper tree barks (Schinus terebinthifolius, Raddi), is used in medicine as wound healing and antiinflamatory. Once extracts from this plant are used for acceleration of scar s process, it is important to study their mutagenic and genotoxic potential. In previous works in our laboratory, it was observed mutagenicity caused by the decoction when in high concentrations. Among the chemical compounds of this plant that could be able to induce mutation, the flavonoids were the only group that was referred to have either an oxidant or antioxidant potential. The flavonoids were isolated, purified and quantified by adsorptive column chromatography under silica gel, bacterial and in vitro genotoxic tests were realized to determine if the flavonoids were the responsible agents for this mutagenicity found. The tests realized with plasmidial DNA were indicative that the flavonoids are probably genotoxic, due to the presence of correlation between increase of the flavonoid concentration and in plasmidial DNA double strand breakage visualized in agarose gel, as well as they were capable to generated abasic sites shown by the in vitro treatment with exonuclease III. The same tests with plasmidial DNA in the presence of copper [10 µM] and of a Tris-HCl pH 7.5 [10 µM] buffer were realized with the isolated flavonoids to determine if there would be or not participation of reactive oxygen species (ROS). The transformation of plasmidial DNA in different bacterial strains proficient and deficient in DNA repair enzymes in the presence or not of a Tris-HCl buffer, suggests that the enzymes that repair oxidative lesions are necessary to repair the lesions generated by the flavonoids and that ROS are generated and are necessary to promote the lesions. Bacterial tests with Escherichia coli strains of the CC collection (deficient or not for DNA repair enzymes), showed that the flavonoids are able to increase the frequency of mutations, mainly in strains mutated in repair enzymes (MutM, MutY-glicosylases and double mutant), suggesting that these agents are responsible for the enhancement in the mutation rate. In order to determine the mutation spectrum caused by the flavonoids of the Brazilian pepper tree stem bark, plasmidial DNA previously treated with the flavonoids were transformed in bacterial strains deficient and proficient in the DNA repair enzymes, followed by a blue-white selection with X-gal, DNA amplification by PCR and sequencing the positive mutant clones. Analysis of the mutants obtained from strains CC104, CC104mutM, CC104mutY, CC104mutMmutY, BW9101, BW9109 indicated a predominance of some mutations like G:C to C:G that can be correlated with the origin of 8-oxoG, due to oxidative lesions caused by the flavonoids. So it can concluded that the flavonoid isolated or in fractions enriched on them are genotoxic and mutagenic, and their mutations are predominantly oxidative, mediated by ROS, and the lesions are recognized by the BER system. In this way it is proposed that the flavonoids can act in two different ways to generate the DNA lesion: 1. in a Fenton-like reaction, when the flavonoid are in the presence of metal ions and that together with the water generate ROS that promotes the DNA lesions; 2. in another way the lesions can be generated by the formation of ROS due to the internal chemical structure of the flavonoid molecule due to the quantity and location of hydroxyl groups, and so producing the DNA lesions, those lesions can be directly (suggested by the in vitro experiments) or indirectly done (supported by the experiments using the CC bacterial strains)

Evaluation of the possible role of ants (Hymenoptera: Formicidae) as mechanical vectors of nematodes and protists

Os Nematoda e Protista podem ser transmitidos ao homem de diversas maneiras, mas pouca ênfase é dada para a transmissão mecânica por intermédio de formigas. Assim, esse trabalho procurou investigar a transmissão mecânica de ovos de Ascaris lumbricoides e cistos de Entamoeba coli pelos Formicidae. Através de experimentos com espécies mantidas em ninhos no laboratório (Tapinoma melanocephalum, Linepithema humile e Monomorium pharaonis) e com 17 espécies de formigas de uma área antropizada na região de Mogi as Cruzes (SP), foi possível constar que os ovos A. lumbricoides foram transportados por L. humile, tanto no campo (1 operária) como no laboratório (1 operária), por Camponotus rufipes (2), por Solenopsis saevissima (1) e por Acromyrmrex niger (1). em três operárias de C. rufipes foram encontrados cistos de E. coli. Apesar da baixa incidência de transporte, as três primeiras espécies pelo fato de viverem muito próximas ao ser humano, podem levar para dentro do ambiente domiciliar patógenos de Nematoda e Protista.

Marcadores sociais da diferença nas experiências travestis de enfrentamento à aids

Os argumentos apresentados neste artigo partem de apontamentos etnográficos oriundos de pesquisa antropológica realizada entre travestis que se prostituem. A partir da análise dessas notas, apresentam-se as categorias classificatórias acionadas pelas travestis que se prostituem a fim de, por esses termos, demarcarem diferenças pouco consideradas pelos formuladores de políticas de saúde, mas que são significativas para elas, pois se referem a maneiras singularizadas de subjetividades nas quais gênero, geração, classe e raça estão implicadas. Assim, procura-se explorar como esses marcadores sociais da diferença operam contextual e relacionalmente nas respostas que esses sujeitos têm elaborado frente à sistemática associação entre travestis e aids, e como esses eixos se enfeixam compondo experiências específicas do adoecer e do sofrimento, ao mesmo tempo em que permitem que as travestis mobilizem diversas estratégias de resistência e enfrentamento a processos de estigmatização. A discussão a ser empreendida vale-se do escopo teórico pós-estruturalista, bem como das contribuições do feminismo como crítica epistemológica.

Identificação dos princípios ativos presentes no extrato etanólico de cereus jamacaru e avaliação em ratos dos possíveis efeitos tóxicos e/ou comportamentais da exposição prolongada

Conselho Nacional de Desenvolvimento Científico e Tecnológico

O jingle e outras práticas culturais dos vendedores de rua de Aracaju/SE

This masters dissertation constitutes in a mapping with base in a field research carried in the streets of commercial center and adjacencies of the Aracaju city, capital of Sergipe state, located in Brazilian‟s Northeast. This is a study about the jingle and others social practices found in the day-by-day of streets by the streets sellers. There is a clear intention of consider the pregão singed by sellers of the street how a jingle that is produced, transmitted and accepted in a means social, characterized how cultural manifestation study. Thus, this ethnography aims to observe the use of the jingle and other cultural practices carried out by street vendors, showing how they are produced, disseminated and consumed in everyday life, as a way to do it. These practices that occur in cities since ancient times continue to occur in all Brazilian cities, including the capital cities, although in some cases, some of them such as the jingle, they get more scarce. Specifically aimed at rescuing the memory of these cultural practices, considering them as "tactics" of practitioners, a resistance of street vendors, individuals, "ordinary" real "anonymous wanderers" in the face of pressure from a dominant force and uneven. In this perspective, the present study is based on the theories of Certeau (1990, 1996) and Coradini (1995) on daily life in the cities, seeking to demonstrate how street vendors engage in a "diverted", subversive, selling its products, creating and using the jingle and other similar relationships that are part of common culture, introducing itself as "ways of doing" that are appropriate or re-appropriated, consumed or accepted in joints over time and within the "anthropological urban spatiality

A construção das representações sociais na relação da polícia militar e a sociedade Aracajuana

In recent years, issues involving public safety have gained more prominence in scientific debates, the media, and common sense, because undoubtedly the feeling of fear and insecurity caused by the increase in violence overall, has spread like construction element of social representations, both in individual levels, as well as collectively. Violence is a social phenomenon existing in human manifestations, from the older societies, ie it was present in all historical periods, but in different ways in the subjective and objective, having had the task of being the central element in modeling process for the formation of individual behavior, both in older societies as in modern society. However, it has a peculiar feature of acquiring new contours to the extent that the individual and collective behaviors are modified in relation individual-violence. In this sense, the institutions that establish the order from the control of violence, have their social representations in the context of social relationships permeated by elements of violence, fear and insecurity, that shift the subjective feeling of insecurity, or existential, for a concrete plan and goal, namely to the level of physical insecurity in daily life in the modern world. The objective of this study was to capture the construction of social representations of the population in Aracaju on the police institution and the figure of the policeman in the contemporary context. We focus our attention only to the institutions of order, which constitute the field of the apparatus of public security and social protection of our state

Ethopoiésis e Heavy Metal: Subjetivação e consumo na cena de Natal-RN

Our research intends to comprehend the configuration of the resistance (Foucault) as the stylization of life in the contemporary world, taking Heavy Metal as the specific object of study. We believe that Heavy Metal is an ethopoietical device which admits practices of freedom withstanding the reified moral habits since the beginning of the socialization. This is reflected, mainly, in the creation of new individual and communal ways to stylize the life. We also suggest an expansion of Foucault s concept of resistance, considering the idea of consumer society described by Zygmunt Bauman. Our hypothesis understands that the contact with the underground of Heavy Metal provides new ethical manners (Foucault), where the individual take the Heavy Metal as a way of life. At this point, the consumption becomes a key-word since the participation in the underground of Heavy Metal is a way of consumption out of the rules of marketing a practice of freedom, a way of particular existence , being different in both mode and duration

Tecendo os fios de rede: juventude e produção de si em projetos sociais.

The study is about youthful subjectivities in quarters, of the West Zone of Natal-RN, marked for lacks and contingencies that constitute the everyday life of the social existence of its young inhabitants. For this purpose the researchers selected two youth groups: the Association of Youths Constructing Dreams (in the quarter of Felipe Camarão) and Lelo Melodia Crew (Quarter of Guarapes). Both are articulated through the strategy of coalition in regional and national nets. The hypothesis is that inside the groups and nets new youthful citizens arises. That would be a change in the representation of poor youth: from 1980 s street children - young whose social stigma associated poverty and crime to late 1990 s kids of project (pointing their trajectory in social projects) or, in present days, called as young peripherals - for the enrollment in cultural movements, as the hip hop movement - These new young citizens are contributing to new social imagery significations on poor youths. The methodology encloses: a) focal group; b) participant research analyzing the making arts (ways to think, social daily practices, actions engaged in a diversity plans) of youth groups; c) life stories of some of the youngs produced in workshops; d) not structuralized interviews. d) several documents of the groups; e) local and national surveys. Results emphasize a feeling of opening to a project of autonomy in relation to a social system that leaves them in a situation of social precariousness. Conclusion remarks that such practices of the youthful groups through the art, leisure, sport and culture unfold politics effect so that can point innovative forms of politics participation on the part of this specific segment of poor youths of Brasilian country, although conflicts and paradoxes crosses individual citizens, youth groups and youth nets.

O espaço de todos, cada um no seu lugar : o uso dos espaçõs públicos destinados ao lazer em Natal

A problemática atual da urbanização coloca questões delicadas referentes ao seu ritmo de crescimento, sua relação com o desenvolvimento econômico, o aparecimento de novas formas urbanas e sua relação com as novas maneiras de articulação capitalista. A compreensão espacial do lazer nas cidades apresenta-se, assim, como tema de grande importância para as sociedades contemporâneas. O interesse e a importância de tratar esse tema na cidade do Natal - enfocando-se a distribuição dos espaços públicos de lazer nos diversos bairros e sua utilização pelos seus habitantes - justifica-se pelo fato dessa capital apresentar um crescimento populacional surpreendente nos últimos anos, tendo uma expansão urbana desordenada que se reflete na carência de infra-estrutura urbana e numa forte segregação espacial. Foram feitas a verificação da disponibilidade de espaços públicos de lazer nos bairros e a identificação dos diversos fatores que interferem na utilização desses espaços, visando contribuir para a compreensão do fenômeno do lazer urbano, bem como, para o aprofundamento da discussão acerca da função social desses, que possibilite montar estratégias para a utilização de forma democrática desses espaços nas cidades. Para tanto foi necessária uma articulação teórica das questões peltinentes ao espaço urbano e ao lazer, que formam uma área epistemológica de interseção quando trata das questões referentes ao direito à cidadania, onde está contemplado o direito à cidade (á moradia e ao seu entomo). Os dados para que caracterizaram as vivências do lazer nos espaços públicos da cidade foram levantados em três fontes: nos documentos (plano diretor da cidade, planos de políticas públicas entre outros), nas entrevistas com a comunidade e nas observações diretas dos espaços de manifestações do lazer. A análise aponta que existe uma distribuição irregular dos espaços públicos de lazer, por bairro e Região Administrativa da cidade do Natal que apresenta relação com a segregação espacial por classe, existente na cidade, fruto da dinâmica econômica e práticas sociais aqui existentes. Constata-se ainda que a camada desprovida desses equipamentos de lazer não age espontaneamente, nem através de seus representantes e mandatários institucionais, em prol da distribuição de oportunidades nesses campos, possibilitando que a segregação continue em círculos viciosos, pois a própria segregação dificulta o encontro, a percepção das diferenças e o conflito, que podem ser resgatados numa nova forma de organização do cotidiano

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

Os efeitos da estrutura de habitat sobre as comunidades de aranhas em uma floresta de caatinga do nordeste brasileiro

The inherent complexity of natural communities is a challenge to our understanding about how the habitat influences the abundance, local distribution and species diversity. The habitat can influence community structure in multiple ways and elucidate these relationships has provoked a lot of debate in ecology. The habitat heterogeneity hypothesis states that an increase in habitat heterogeneity (number of habitats) leads to an increase in species diversity in the landscape due to an expansion in niche dimensions. This study aims to identify whether this hypothesis is valid for the spiders that inhabit a locality in the Caatinga of northeastern Brazil. Cursorial and arboreal spiders were sampled in 30 plots within an area of Caatinga together with measures of environmental complexity, habitat heterogeneity and environmental parameters related to multiple aspects of vegetation architecture and species composition of woody plants. Stepwise multiple regressions were used to define which local environmental parameters best explain the variation in arboreal and cursorial spiders richness. Then a NMDS (Nonmetric multidimensional scaling) was used to reduce the number of predictive variables to those who are the most important and best represent the variation in spiders richness associated with the environment they were sampled. The results show a clear segregation between the guilds of arboreal and cursorial spiders, both related to what kind of environmental variables best explain its variation as well as in relation to what part of the vegetation they occupy

Diálogos e reflexão

The present work highlights the importance of Dialogue in dealing with situations of crisis, and human conflicts. It has a starting point in some ideas of David Bohm, and in so doing, it presents itself with the challenge of testing the premise that dialogical strategies, of thought and action, can make the human choices inherent to those situations, more coherent and creative. They also allow us to elucidate and grasp them, towards broader comprehension and resolution, while keeping the framework of consistent assessment. However, we believe that said strategies are not, necessarily, problem solvers. With that in mind, we expanded the notion of Dialogue , systematizing dialogical visions of the world, derived from the ideas of David Bohm, Paulo Freire and Mikhail Bakhtin, in which they give priority to the Dialogue component, in all human relations within crucial contexts. From the elaboration of that systemic and dialogical interface, in which Dialogue appears as common theme, and pervasive tool, we detected the emerging of ancillary themes such as Liberty , Consciousness , Creativity , Ethics and Responsibility . We see these themes as ways of comprehending Life, as each one embodies interests, needs and shared human motivations. We have articulated them as a network, and added to that the need of Reflection in conjunction with Dialogue as a watchful call for noticing the incoherence

Autoconhecimento e práticas corporais: para uma educação transpessoal integradora do saber ao ser no processo de formação inicial dos alunos de educação física

This thesis deals with the self-knowledge importance and corporal practices and the contribution of the Transpersonal Education for the initial formation process of students of Physical Education. In this context, students are stimulated to come in contact with the bases of learning to know, to make, to live together and to be for the promotion of integral education. We give priority to holistic conception of educating based in Emergent Paradigm. In this conception, student in initial formation is led to get back the view of integral being, life and love as education basis. We had as starting point, the essential dimensions to the learning geared toward the embodiment integration, autopoiesis and trans-disciplinarity. This work presents tracks for the teacher formation of Physical Education. It deals with the unfolding of teaching experiences in 2006, in Graduation Course in Physical Education of Universidade Federal do Rio Grande do Norte, in subject of Corporal Conscience, offered to undergraduate students which can be characterized as an action-research. This process was chosen as knowledge and intervention method because it allowed knowing and acting at the same time, studying the conditions and results of accomplished experience. In shared meetings with reflected experiences, we appeal to the experiences of situations that had mobilized the corporal, emotional, mental and spiritual dimensions of participants. The data collected through observations, accounts, questionnaires and interviews of learning processes had been starting points for the beginning of dialogue along with students of Graduation Course in Physical Education. The findings had been interpreted through of hermeneutics and discourse analysis. In this research, participants are considered as protagonist and boosters of educative process. The theoretical basis was supported by Transpersonal Education which contributed for a peace culture and respectful relationship. In its initial formation process, this research protagonists had evidenced of the importance of transpersonal education, geared toward action and changing, new ways of being and living together, facing the daily conflicts from a human and rational perspective. The research emphasized the importance of a new look on the teacher formation of Physical Education to face the limits of fragmented formation. Thus, we recognize that through the teacher education process, the transpersonal education provided wide significant changes reported during research, extending and re-meaning different learning levels such as: cognitive, emotional, attitudinal, and behavioral geared toward the personal and transpersonal development, reiterating the relevance of self-knowledge for development and establishment of pedagogical practice which prioritizes the life direction. The necessity of integrating knowledge to being in the initial process of teaching formation was emphasized in all the transpersonal meetings