Desenvolvimento de material BaCexPr1-xO3 (0 ≤ X ≤ 1) com estrutura perovskita para oxidação catalítica do CO a CO2 em reator de leito fixo

Barium Cerate (BaCeO3) is perovskite type structure of ABO3, wherein A and B are metal cations. These materials, or doped, have been studied by having characteristics that make them promising for the application in fuel cells solid oxide, hydrogen and oxygen permeation, as catalysts, etc .. However, as the ceramic materials mixed conductivity have been produced by different synthesis methods, some conditions directly influence the final properties, one of the most important doping Site B, which may have direct influence on the crystallite size, which in turn directly influences their catalytic activity. In this study, perovskite-type (BaCexO3) had cerium gradually replaced by praseodymium to obtain ternary type materials BaCexPr1-xO3 and BaPrO3 binaries. These materials were synthesized by EDTA/Citrate complexing method and the material characterized via XRD, SEM and BET for the identification of their structure, morphology and surface area. Moreover were performed on all materials, catalytic test in a fixed bed reactor for the identification of that person responsible for complete conversion of CO to CO2 at low operating temperature, which step can be used as the subsequent production of synthesis gas (CO + H2) from methane oxidation. In the present work the crystalline phase having the orthorhombic structure was obtained for all compositions, with a morphology consisting of agglomerated particles being more pronounced with increasing praseodymium in the crystal structure. The average crystal size was between 100 nm and 142,2 nm. The surface areas were 2,62 m²g-1 for the BaCeO3 composition, 3,03 m²g-1 to BaCe0,5Pr0,5O3 composition and 2,37 m²g-1 to BaPrO3 composition. Regarding the catalytic tests, we can conclude that the optimal flow reactor operation was 50 ml / min and the composition regarding the maximum rate of conversion to the lowest temperature was BaCeO3 to 400° C. Meanwhile, there was found that the partially replaced by praseodymium, cerium, there was a decrease in the catalytic activity of the material.

Implementação das diretrizes operacionais para a educação básica nas escolas do campo: embates e limitações do trabalho docente no Rio Grande do Norte

Considering the situation of neglect existing in Brazilian public education and, specially, in the process of rural schooling, this dissertation aims to analyze the process of implementation of the Operational Guidelines for Basic Education in Rural Schools (DOEBEC), regulatory framework of the national policy of rural education. On it, we analyze the conditions of teaching work in rural schools of Rio Grande do Norte (RN), in 2010. The sample of the survey has as reference the representativeness of the chosen universe in relation to the totality of rural schools belonging to the state of RN. To answer the goals of the research, we opted to present a critical analysis of the following points: 1) Implementation of the DOEBEC; 2) Conditions of teaching work and teaching training. The points or categories of research were chosen based in the determinations of the DOEBEC (Resolution CNE/CEB n. 01/2002). For the data collection in the referred schools, we opted for the realization of interviews with the teachers and managers of these teaching establishments, in 2010. It was also utilized, for the characterization of school attendance in rural schools of RN, in 2010, official statistical data available by the State Secretary of Education and Culture (SEEC/RN). The analysis of the statistical data and of the primary data collected in field research indicated that the conditions of teaching work are still an obstacle to the development of the educative work of the teacher in rural areas. According to interviews with the participants of the research, we realized that the DOEBEC, despite being sanctioned in 2002, were still dimly known and discussed by the interviewees of the referred schools in 2010. Thus, we propose that the implementation of the policy of rural education in RN, instituted by DOEBEC’s legal landmark, and reaffirmed by the Rio Grande do Norte’s Charter to Rural Education (Brazil, 2005), is rethought and reconsidered, in the sense of ensuring that the changes proposed in this legal text, inherent to the school functioning, to the conditions of teaching work, to the rural schools’ management, to the remuneration and valorization of teaching work, to the teaching training, to the conditions of school transport, among others, be turned into concrete actions to improve the quality of education offered in the rural schools of RN state.

Implementação das diretrizes operacionais para a educação básica nas escolas do campo: embates e limitações do trabalho docente no Rio Grande do Norte

Considering the situation of neglect existing in Brazilian public education and, specially, in the process of rural schooling, this dissertation aims to analyze the process of implementation of the Operational Guidelines for Basic Education in Rural Schools (DOEBEC), regulatory framework of the national policy of rural education. On it, we analyze the conditions of teaching work in rural schools of Rio Grande do Norte (RN), in 2010. The sample of the survey has as reference the representativeness of the chosen universe in relation to the totality of rural schools belonging to the state of RN. To answer the goals of the research, we opted to present a critical analysis of the following points: 1) Implementation of the DOEBEC; 2) Conditions of teaching work and teaching training. The points or categories of research were chosen based in the determinations of the DOEBEC (Resolution CNE/CEB n. 01/2002). For the data collection in the referred schools, we opted for the realization of interviews with the teachers and managers of these teaching establishments, in 2010. It was also utilized, for the characterization of school attendance in rural schools of RN, in 2010, official statistical data available by the State Secretary of Education and Culture (SEEC/RN). The analysis of the statistical data and of the primary data collected in field research indicated that the conditions of teaching work are still an obstacle to the development of the educative work of the teacher in rural areas. According to interviews with the participants of the research, we realized that the DOEBEC, despite being sanctioned in 2002, were still dimly known and discussed by the interviewees of the referred schools in 2010. Thus, we propose that the implementation of the policy of rural education in RN, instituted by DOEBEC’s legal landmark, and reaffirmed by the Rio Grande do Norte’s Charter to Rural Education (Brazil, 2005), is rethought and reconsidered, in the sense of ensuring that the changes proposed in this legal text, inherent to the school functioning, to the conditions of teaching work, to the rural schools’ management, to the remuneration and valorization of teaching work, to the teaching training, to the conditions of school transport, among others, be turned into concrete actions to improve the quality of education offered in the rural schools of RN state.

Estádios larvais e ocorrência sazonal de imaturos de Psaroniocompsa incrustata (Lutz,1910)(Diptera:Smimuliidae) no Rio Pium, município de Nísia Floesta, RN

The larval instars, seasonal occurrence and environmental factors influence on Psaroniocompsa incrustata (Lutz, 1910) (Diptera: Simuliidae) immature were studied according to its physical and chemical aspects of breeding water. Four collects were made at vegetal substrate from margin, middle and floating on the Pium river, city of Nísia Floresta, state of Rio Grande do Norte, Brazil at dry and wet season. Some of larval characters were used to determinate the larval instars number like lateral length of cephalic capsulae, antennae and the distance among cephalic apodema, as well as pH, water temperature, width, depth, stream velocity, discharge and pluviometric precipitation were used for physical factors. Seven larval instars were determined for this P. incrustata community being the lateral length of cephalic capsulae as the best structure with this meaning propose. The seasonality immature abundance of this species were found in dry season and a positive correlation with pH, stream velocity and precipitation

Estudo de adsorvente obtido de terras diatomáceas para remoção de metais pesados em águas produzidas: processamento, caracterização e dinâmica em leito fixo

The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Macaíba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry