996 resultados para Metais do grupo da platina


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The produced water is a byproduct formed due to production of petroleum and carries with it a high amount of contaminants such as oil particles in suspension, organic compounds and metals. Thus, these latter pollutants are very difficult to treat because of its high solubility in water. The objective of this work is to use and evaluate a microemulsioned system to remove metals ( K , Mg , Ba , Ca , Cr , Mn , Li , Fe ) of synthetic produced water. For the extraction of metals, it was used a pseudoternary diagram containing the following phases: synthetic produced water as the aqueous phase (AP), hexane as organic phase (OP), and a cosurfactant/surfactant ratio equal to four (C/S = 4) as the third phase, where the OCS (saponified coconut oil) was used as surfactant and n-butanol as cosurfactant. The synthetic produced water was prepared in a bench scale and the region of interest in the diagram for the removal of metals was determined by experimental design called. Ten points located in the phase Winsor II were selected in an area with a large amount of water and small amounts of reagents. The samples were analyzed in atomic absorption spectrometer, and the results were evaluated through a statistical assesment, allowing the efficiency analysis of the effects and their interactions. The results showed percentages of extraction above 90% for the metals manganese, iron, chromium, calcium, barium and magnesium, and around 45% for metals lithium and potassium. The optimal point for the simultaneous removal of metals was calculated using statistical artifact multiple response function (MR). This calculation showed that the point of greatest extraction of metals occurs was the J point, with the composition [72% AP, 9% OP, 19% C/S], obtaining a global extraction percentage about 80%. Considering the aspects analyzed, the microemulsioned system has shown itself to be an effective alternative in the extraction of metals on synthetic produced water remediation

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The DGT technique allows one to measure quantitatively free and labile metal species in aquatic systems. Nevertheless, for this approach, knowledge is required of the diffusion coefficients of the analytes in a diffusive layer. In this study, the diffusion coefficients of Hg(II), As(III), Mn(II), Mg(II), Cu(II), Cd(II) were determined in agarose gel and those of Ba(II), Cd(II), Cu(II), Mg(II), Mn(II) e Zn(II) in cellulose acetate membranes. These materials presented good performance and the reported results can be used as a data base for further DGT studies.

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The objective of this work was to evaluate Cd, Cr, Ni and Pb total contents in soil and sugar cane after four annual applications of sewage sludge and vinasse to supply all N and all K required by the crop. A field experiment was carried out on clayey Typic Haplustox. It was used a randomized block design with seven treatments and three replications. The treatments consisted in: (i) rate of sewage sludge to supply 100% of the N required by the crop; (ii) rate of sewage sludge to supply 200% of the N required; (iii) rate of vinasse to supply 100% of the K required; (iv) rate of vinasse to supply 200% of the K required; ( v) combination of the treatments ( i) and ( iii); ( vi) combination of the treatments ( ii) e ( iv); (vii) control ( mineral fertilization). The contents of Cd, Cr, Ni and Pb in sewage sludge reached maximum values of 1.58, 41.66, 35.17 and 45.25 mg kg(-1), respectively. These metals were not detected in vinasse. The residues were applied annually for four years. At the end of this period, sewage sludge and vinasse accumulated rates, that get up to 51 t ha(-1) and 762 m(3) ha(-1), respectively, did not cause alteration in Cd, Cr, Ni and Pb total contents in soil, up to 50 cm of depth, and in plant. Sewage sludge and vinasse application to supply N and K for sugar cane did not offer soil pollution risk by heavy metals.

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The Caatinga is the predominant vegetation type in semi-arid region of Brazil, where many inhabitants depend on hunting and gathering for survival, obtaining resources for: food and feed, folk medicine, timber production, etc. It‟s the dry ecosystem with highest population density in the world. The early stages of development are the most critical during the life cycle of a flowering plant and they‟re primordial to its establishment in environments exposed to water stress. Information about adjustments to the growth of the species, correlated with their studies of distribution in Seridó oriental potiguar, are an important ecological and economic standpoint, because they provide subsidies for the development of cultivation techniques, to programs of sustainable use and recovery of degraded areas. This thesis aimed to study the initial growth and foliar morphology in plants like Enterolobium contortisiliquum (Vell.) Morong. (tamboril) and Erythrina velutina Mart. ex Benth (mulungu), species of occurrence in the Caatinga, under water stress. After sowing and emergency, the seedlings were exposed to three water regimes: 450 (control), 225 (moderate stress) and 112.5 (severe stress) mm of water slide for 40 days. Seeding occurred in bags of 5 kg and after the establishment of seedlings thinning was carried out leaving a plantlet per bag. At the beginning the waterings occurred daily with distilled water, passing to be on alternate days after thinning. Twenty and forty days after the thinning seedlings collections were held to be done analysis of growth and biomass partition. When compared to the control group, the treatments with water stress showed reduction in the growth of the aerial part, growth of the greater root, number of leaves and leaflets, dry leaf area and total phytomass in both species, but in general, this effect was most marked for E. velutina. Regarding the partition of biomass, there were few changes throughout the experiment. Morphological changes in the leaves as a function of stress were not significant, however, there was a trend, in both species, to produce narrower leaves, that facilitate heat loss to the environment. It has not been possible to establish a positive relationship between inhibition of growth and distribution of species, whereas E. velutina is a species of most common occurrence in Seridó oriental potiguar. In this way, other aspects should be taken into account when studying the adaptation of species the dry environments, such as salinity, presence of heavy metals, wind speed, etc

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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mongst the trends in Mathematics Education, which have as their object a more significant and criticallearning, is the Ethnomathematics. This field of knowledge, still very recent amongst us, besides analyzing an externalist history of the sciences in a search for a relationship between the development of the scientific disciplines and the socio-cultural context, goes beyond this externalism, for it also approaches the intimate relationships betwe_n cognition and culture. In fact, the Ethnomathematics proposes an alternative epistemological approach associated with a wider historiography. It struggles to understand the reality and come to the pedagogical action by means of a cognitive approach with strong cultural basis. But the difficulty of inserting the Ethnomathematics into the educational context is met by resistance from some mathematics educators who seem indifferent to the influence of the culture on the understanding of the mathematics ideas. It was with such concerns in mind that I started this paper that had as object to develop a curricular reorientation pedagogical proposal in mathematics education, at the levei of the 5th grade of the Ensino Fundamental (Elementary School), built from the mathematical knowledge of a vegetable farmers community, 30 km away from the center of Natal/RN, but in accordance with the teaching dimensions of mathematics of the 1 st and 2nd cycles proposed by the Parâmetros Curriculares Nacionais - PCN: Numbers and Operations, Space and Form, Units and Measures, and Information Treatment. To achieve that, I developed pedagogical activities from the mathematical concepts of the vegetable farmers of that community, explained in my dissertation research in the period 2000 through 2002. The pedagogical process was developed from August through Oecember 2007 with 24 students of the 5th Grade of the Ensino Fundamental (Elementary School) of the school of that community. The qualitative analysis of the data was conducted taking into account three categories of students: one made up of students that helped their parents in the work with vegetables. Another one by students whose parents and relatives worked with vegetables, though they did not participate directly of this working process and one third category of students that never worked with vegetables, not to mention their parents, but lived adjacent to that community. From the analyses and results of the data gathered by these three distinct categories of students, I concluded that those students that assisted their parents with the daily work with vegetables solved the problem-situations with understanding, and, sometimes, with enriching contributions to the proposed problems. The other categories of students, in spite of the various field researches to the gardens of that community, before and during the pedagogical activities, did not show the same results as those students/vegetable farmers, but showed interest and motivation in ali activities of the pedagogical process in that period

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The thesis: "autobiographical narrative as practical continuous training and updating of itself: the groups-reference and the reflexive group in the mediation of identity construction of teaching" begins in the founder matter: "What are the implications of groups-reference in the process of identity formation and the teaching role of teachers which is participating of the research? This object of study deals with the continuing education of teachers of Basic Education and the role of the reflective group as space-time of (re) construction of educational knowledge, for the recognition of yourself. The thesis defends that the autobiographical narrative, as a pedagogical tool and research, for the initial and continuous training, is presented as theoretical and methodological foundation necessary for identity formation of the teacher. The research is limited to the qualitative approach with a focus on the autobiographical narrative. The participants are six teachers, three teachers and three students-teachers. The corpus comprises six autobiographical narratives, six reports of successful experiences, two studies on the biographical work, and six individual testimonials about the impact in personal and professional life. The data analysis was to reference Dausien and Alheit (2006), Bruner (1997), Contreras (2002), Delory-Momberger (2007), Freire (2005), Giddens (2002), Josso (2004), new (1988, 2002), Passeggi (2001, 2002), Pineau (2004), Ricoeur (2004), Souza (2006), Tardif (2002) and Vygotsky (2005). The research revealed that the formation of identity as a teachers of the educators occurred in the reference group, involving the formal, non-formal and informal of the processes of knowledge , in a movement of alternation training that includes yourself, the other and the ambient. Also revealed that the pedagogical choices of the teachers studied aimed at minimizing educational gaps that were lived in both field personal and social; that the personal identity is configured as an identity narrative and the methodology of the biographical work, through the mimesis of continuing education, provided the passage from the group reflective to the group of reference

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This work aims to analyze the historical and epistemological development of the Group concept related to the theory on advanced mathematical thinking proposed by Dreyfus (1991). Thus it presents pedagogical resources that enable learning and teaching of algebraic structures as well as propose greater meaning of this concept in mathematical graduation programs. This study also proposes an answer to the following question: in what way a teaching approach that is centered in the Theory of Numbers and Theory of Equations is a model for the teaching of the concept of Group? To answer this question a historical reconstruction of the development of this concept is done on relating Lagrange to Cayley. This is done considering Foucault s (2007) knowledge archeology proposal theoretically reinforced by Dreyfus (1991). An exploratory research was performed in Mathematic graduation courses in Universidade Federal do Pará (UFPA) and Universidade Federal do Rio Grande do Norte (UFRN). The research aimed to evaluate the formation of concept images of the students in two algebra courses based on a traditional teaching model. Another experience was realized in algebra at UFPA and it involved historical components (MENDES, 2001a; 2001b; 2006b), the development of multiple representations (DREYFUS, 1991) as well as the formation of concept images (VINNER, 1991). The efficiency of this approach related to the extent of learning was evaluated, aiming to acknowledge the conceptual image established in student s minds. At the end, a classification based on Dreyfus (1991) was done relating the historical periods of the historical and epistemological development of group concepts in the process of representation, generalization, synthesis, and abstraction, proposed here for the teaching of algebra in Mathematics graduation course

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Ce travail a pour objet d'étude le Groupe Scolaire Augusto Severo, situé à Natal, première institution du type dans l'État du Rio Grande do Norte. Il analyse la pratique pédagogique, le modèle d'éducation primaire et d'expérimentation des personnes en formation de l'École Normale de Natal, entre 1908 et l'année de 1928. Dans cette période, se sont produites des tentatives d'organisation scolaire par le biais de la Réforme de l‟Enseignement Primaire (1908) et de la Réforme de l‟Enseignement (1916). Nous nous sommes basés sur l'Histoire Culturelle définie à travers la conjonction de l'histoire des objets dans sa matérialité, des pratiques dans leurs différences et configurations, des dispositifs dans leurs variations. Nous avons utilisé les journaux A República et Diário do Natal, la revue Pedagogium, des Lois, des Décrets et Messages du Gouvernement, des Codes d'Enseignement et le Régime Interne des Groupes Scolaires, documents qui proviennent du fonds de l'Institut Historique et Géographique do Rio Grande do Norte (IHGRN) et des sources iconographiques, provenant de l'Institut du Patrimoine Historique et Artistique National (IPHAN/RN). Dans les Archives Publiques de l‟Etat (APE/RN) nous avons recherché les Livres d'Enregistrement des Groupes Scolaires et Écoles Isolées, Offices, Inscriptions, Rapports et Actes de réunions de la Direction Générale de l'Instruction Publique et Journal de Classe. Nous avons analysé l'action des professeurs dans cette institution primaire, ainsi que l'histoire des disciplines scolaires et des programmes d'enseignement, la problématique des contenus et méthodes. Nous avons observé que la méthode intuitive était la dynamique de la pratique pédagogique efficace et que les rites de récompense, les cérémonies civiques composaient l‟ensemble des idées modernisatrices de l‟époque

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El trabajo que aquí se presenta tuvo como objetivo investigar una institución escolar en la ciudad de Macau / RN. Esta institución, que fue innovadora en su contexto social y pedagógico, fue pesquisada a la luz de los parámetros de la historia cultural. Una escuela que fue creada en el siglo XX, en el año de 1923, cuando el país aún vivía la efervescencia de la implantación del nuevo ordenamiento político - la República. Elegimos como objeto de estudio las fiestas escolares, que tuvo lugar en esta institución durante el periodo 1949-1962, procurando aclarar cómo ocurría la realización de estas fiestas y cómo fueron fundamentales para el funcionamiento de las relaciones políticas, sociales y culturales en el ámbito escolar. El análisis y la interpretación de las fuentes documentales escolares, los documentos de otras instituciones, las entrevistas abiertas, la información oral, la legislación de la educación y de las escuelas, los periódicos y documentos oficiales de la época relacionados con la temática y que formaron el corpus documental, se basaron por obras de Souza (1998), Juliá (2001), Castro (1997), Kossoy (2001) Saviani (2005), Escolano (1992) y Carvalho (1990). Por tratarse de una institución de enseñanza, el análisis central es la cultura escolar y la historia de la educación brasileña es el campo de la investigación, haciendo una relación de las fiestas escolares. En el relato, se reconstituyen las festividades cívicas, solemnes y recreativas, además de los elementos de formación que se evidencian en el discurso de la educación moderna. Para ello, buscamos entender que, en las prácticas cotidianas de la escuela, había un método de actuación que seguía las directrices del Departamento de Educación. Estas directrices eran dadas por medio de las normas y decretos editados y se adentraban en el discurso en torno de las iniciativas emprendidas para difundir las nuevas prácticas pedagógicas, y dentro de ellas, en el momento apropiado, los profesores dedicaban un tiempo de sus clases para explicar acerca de los días festivos y sus organizaciones. Estas constataciones fueron certificadas por la documentación listada y por las entrevistas abiertas, y nos señaló para el modelo escolar propugnado por el Grupo Escolar Duque de Caxias, que era fruto del nuevo orden republicano

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La recherche intitulée l Histoire des femmes agées du group Aurore de La Vie: Campina Grande-PB (1940-1950) a surgit comme consequence de mon observation sur les interêts de femmes en retrouner à l école aprés qu elles étaient arrivées aux soixante ans, um moment de la vie que malgré son importance est encore considerée par trop de gens comme des moments d être seul jusqu à la fin de la vie. Alors, nous avons formulé la question la plus importante de ce travail: Quel est l histoire de l éducation des femmes agées du group Aurore de La Vie, dans le période de son education d enfant? Un group de 25 femmes qui ont étudié le projet Digna, on a fait une seletion de treize agées, entre 65 et 80 ans, qui s appellent: Perpétua, Florinda, Benta, Ambrósia, Celestine, Cordélia, Circe, Filomena, Desdêmona, Dorotéia, Ofelia, Martítius e Nausica. Beaucoup d intelectuels nous ont aidé avec la base theórico-methodologique et nous ont presenté l histoire des excludées comment une histoire en construction. Parmis ces intelectuelles on rencontre Chartier, Halbwachs, Elias, Perrot, Bosi, Bezerra, Morais et Machado. Pendant notre recherche nous avons employés des narrations, des entrevues, des questions ouvertes ou les femmes puissent parler sur l histoire de leur vie. Nous avons regardé aussi le fiche des agées, le arquive de La Secretarie Municipale de Assistence Social (SEMAS) du Hôtel de Ville de Campina Grande-PB. Nous avons aussi étudié sur la legislation relié à la tematique de la Constituition Brésilienne dans l estatute et dans la Politique Nacional de l age. Notre étude nous a donné des analises sur les themas: pauvresse, travail, sourvenirs, jeux e aussi punitions scolaires. Nous sommes arrivés à la conclusion qu à l époque de son enfance, l éducation formale était déjá determinée pour le mariage, la pró-création la famille. Enfim toujours dédans de la maison excludées du reste du monde. Nous avons compris que pesquiser cet object d étude est un contribut avec l histoire des excludées en cassant le silence des femmes lesqueles on été ignorées par presque toute la prodution historiographique