Determinação de CD, PB, e TL em água produzida por HR-CS GF AAS após extração em ponto nuvem

Produced water is a major problem associated with the crude oil extraction activity. The monitoring of the levels of metals in the waste is constant and requires the use of sensitive analytical techniques. However, the determination of trace elements can often require a pre-concentration step. The objective of this study was to develop a simple and rapid analytical method for the extraction and pre-concentration based on extraction phenomenon cloud point for the determination of Cd, Pb and Tl in produced water samples by spectrometry of high resolution Absorption source continues and atomization graphite furnace. The Box Behnken design was used to obtain the optimal condition of extraction of analytes. The factors were evaluated: concentration of complexing agent (o,o-dietilditilfosfato ammonium, DDTP), the concentration of hydrochloric acid and concentration of surfactant (Triton X -114). The optimal condition obtained through extraction was: 0,6% m v-1 DDTP, HCl 0,3 mol L-1 and 0,2% m v-1 of Triton X - 114 for Pb; 0,7% m v-1 DDTP, HCl 0,8 mol L-1 and 0,2% m v-1 Triton X-114 for Cd. For Tl was evidenced that best extraction condition occurs with no DDTP, the extraction conditions were HCl 1,0 mol L-1 e 1,0% m v-1 de Triton X - 114. The limits of detection for the proposed method were 0,005 µg L-1 , 0,03 µg L-1 and 0,09 µg L-1 to Cd, Pb and Tl, Respectively. Enrichment factors Were greater than 10 times. The method was applied to the water produced in the Potiguar basin, and addition and recovery tests were performed, and values were between 81% and 120%. The precision was expressed with relative standard deviation (RSD) is less than 5%

Desenvolvimento de metodologia de extração e pré-concentração utilizando sistema microemulsionado para determinação de Cd, Co, Cu, Ni, Pb e Tl em águas naturais e produzidas por HR-CS AAS

The determination and monitoring of metallic contaminants in water is a task that must be continuous, leading to the importance of the development, modification and optimization of analytical methodologies capab le of determining the various metal contaminants in natural environments, because, in many cases, the ava ilable instrumentation does not provide enough sensibility for the determination of trace values . In this study, a method of extraction and pre- concentration using a microemulsion system with in the Winsor II equilibrium was tested and optimized for the determination of Co, Cd, P b, Tl, Cu and Ni through the technique of high- resolution atomic absorption spectrometry using a continuum source (HR-CS AAS). The optimization of the temperature program for the graphite furnace (HR-CS AAS GF) was performed through the pyrolysis and atomization curves for the analytes Cd, Pb, Co and Tl with and without the use of different chemical modifiers. Cu and Ni we re analyzed by flame atomization (HR-CS F AAS) after pre-concentr ation, having the sample introduction system optimized for the realization of discrete sampling. Salinity and pH levels were also analyzed as influencing factors in the efficiency of the extraction. As final numbers, 6 g L -1 of Na (as NaCl) and 1% of HNO 3 (v/v) were defined. For the determination of the optimum extraction point, a centroid-simplex statistical plan was a pplied, having chosen as the optimum points of extraction for all of the analytes, the follo wing proportions: 70% aqueous phase, 10% oil phase and 20% co-surfactant/surfactant (C/S = 4). After extraction, the metals were determined and the merit figures obtained for the proposed method were: LOD 0,09, 0,01, 0,06, 0,05, 0,6 and 1,5 μg L -1 for Pb, Cd, Tl, Co, Cu and Ni, re spectively. Line ar ranges of ,1- 2,0 μg L -1 for Pb, 0,01-2,0 μg L -1 for Cd, 1,0 - 20 μg L -1 for Tl, 0,1-5,0 μg L -1 for Co, 2-200 μg L -1 and for Cu e Ni 5-200 μg L -1 were obtained. The enrichment factors obtained ranged between 6 and 19. Recovery testing with the certified sample show ed recovery values (n = 3, certified values) after extraction of 105 and 101, 100 and 104% for Pb, Cd, Cu and Ni respectively. Samples of sweet waters of lake Jiqui, saline water from Potengi river and water produced from the oil industry (PETROBRAS) were spiked and the recovery (n = 3) for the analytes were between 80 and 112% confirming th at the proposed method can be used in the extraction. The proposed method enabled the sepa ration of metals from complex matrices, and with good pre-concentration factor, consistent with the MPV (allowed limits) compared to CONAMA Resolution No. 357/2005 which regulat es the quality of fresh surface water, brackish and saline water in Brazil.

Undersampled Critical Branching Processes on Small-World and Random Networks Fail to Reproduce the Statistics of Spike Avalanches

The power-law size distributions obtained experimentally for neuronal avalanches are an important evidence of criticality in the brain. This evidence is supported by the fact that a critical branching process exhibits the same exponent t~3=2. Models at criticality have been employed to mimic avalanche propagation and explain the statistics observed experimentally. However, a crucial aspect of neuronal recordings has been almost completely neglected in the models: undersampling. While in a typical multielectrode array hundreds of neurons are recorded, in the same area of neuronal tissue tens of thousands of neurons can be found. Here we investigate the consequences of undersampling in models with three different topologies (two-dimensional, small-world and random network) and three different dynamical regimes (subcritical, critical and supercritical). We found that undersampling modifies avalanche size distributions, extinguishing the power laws observed in critical systems. Distributions from subcritical systems are also modified, but the shape of the undersampled distributions is more similar to that of a fully sampled system. Undersampled supercritical systems can recover the general characteristics of the fully sampled version, provided that enough neurons are measured. Undersampling in two-dimensional and small-world networks leads to similar effects, while the random network is insensitive to sampling density due to the lack of a well-defined neighborhood. We conjecture that neuronal avalanches recorded from local field potentials avoid undersampling effects due to the nature of this signal, but the same does not hold for spike avalanches. We conclude that undersampled branching-process-like models in these topologies fail to reproduce the statistics of spike avalanches.

Ideais formativos de homem da emissora de Educação Rural de Caicó (Rio Grande do Norte, 1963-1978)

Under the aegis of the third diocese bishop of Caicó, Dom Manuel Tavares de Araújo, the Broadcasting Station of Rural Education of that city was founded, in May 1 s" 1963 with the ideal of being then an educational city, preferentially for youths and adults, rural meu and women of the arca of Seridó in Rio Grande do Norte state. In the year of its 40th birthday (2003), we began the investigation of that radio station choosing as study object its educational and formative programming, in the inc1usion of the first fifteen years of its existence (1963-1978), period that reaches the official inauguration of the Radio Station and the end of the bishopric of its fOllllder as Bishop of Caicó. Elucidating and showing Man's formative ideaIs longed by that Catholic educational broadcasting station, underlying to its radiophonic programming, such as the idealization for it reached, is the objective of this Doctorate work. It was considered pertinent to discover the guidelines that historically have permeated the Social Doçtrine of the Catholic Church addressing its aggiornamento, especially in what concerns to the employment of the modern ways of communication for the distance with the aim of evangelizing and educating. In arder to understand the ideaIs of the investigated educational Radio, we have delimited the research to the thematic Catholic Church, means of social communication and base education. In face of the study object and the aim to be reached it was appealed, methodologically, to the notion of cultural action present in Certeau (1995), and to the understanding of educational formation backgrounded fIam the modern thinkers that discuss it. Such frame references have allowed us to analyze in a wider spectrum tl)e programming broadcasted on the air by the sound wavys of that educ(itional Çatholic Radio, as well as, the very acts of cultural idealizations that has orientated it in its foundations. The thesis here defended is that. the Radio, at procJaiming itself as a broadcasting station of rural education directed preferably to the rural sertanejo countrymen, without neglecting its admitted ends, has surpassed them in its overall range. It was identified an articulate approach of its programmatic modules with the guid,elines emanateq from the Catholic Teaching about the use of the. means of social communication. At conceiving, establishin,g and executing an ec1ectic programmatic and div,ersified grating, the Rural Radio of Caicó has transcended to a strict human-Christian formation to request the development of the human, spiritual and cQrporaldimensions, jointly. With suchprogramming, it addressed to the seridoenses as real meu and women inserted in the "sertanej.o" environment with effective structural and existential problems of alI types, induding the hunger, the thirst, the syndical organization, the cQoperativism, the colIective modero work and the absence of universalizing school education. Its radiophonic transmissions, I}lled by the demands of an enlarged, open, dialogic and responsible communication, wheneIllbracing dedicated modules to religious and catechetical emissions, to the entertainment, to the radiojoumalism, to the country root culture, and to the school education of b se for the modality of the School and of the radiophonic classes, subsumed to ideaIs that longed for the formation of a multifaceted and pluridimensional sertanejo Man; of men and women that, without abjuring the Catholicism, were able to understand, to dialogued and to live together with the general demands of a society in progressive mutation, whose economical, social, cultural and educational demands it IDade themselves to be felt through the sertão potiguar of the Serido region, equal way of the intemationalized world

Fatores inibidores do uso de técnicas ambientais nos postos de combustíveis: um estudo de caso em Natal/RN

The objective of this work was to investigate the factors that inhibit the use of Environmental Techniques in the Gas Station of the city of Natal/RN. For this, a survey with the aid of a questionnaire was used like research instrument. It s used a sample for convenience, not probabilistic. For collection of the data, it was used directly application of the questionnaire to the Managers or Assistant managers of the gas station, in accordance with its availability or presence. The data was collected in all the regions of Natal (North, South, East and West). The population in accordance with the data of the ANP of September 2005 is of 111 ranks and the collected sample was of 86. To carry through the analysis of the data of this research had been used softwares Excel and Statistic version 5.0, for Windows. The analysis of data is divided in two parts; descriptive analysis and analysis of groupings (clusters). The results showed that bigger part of the interviewed ones has between 30 and 39 years of age; they have second grade completed; they had declared to have little between and reasonable knowledge how much to the use of Clean Technology (CT) in gas station; and a small part of the interviewed ones had informed to have much knowledge how much the resolutions of the CONAMA established for the Gas Station. Of the searched ranks, the majority is national(76.7%); the most accurate practice environmental used in the gas station are: it collects selective of oil used or contaminated and ecological tanks - coated with strengthened fibre glass; great part of the interviewed ones (33.8%) informed that never the TL makes planning of referring future action; about of the half of the interviewed ones (84.9%) they had more declared that its employees have of none to a reasonable level of training for deal with problems that compromise the environment; the majority of the ranks (72.1%) functions has for more then six years. It is observed that almost all the interviewed ones (96.5%) evaluate as being important or very important the implantation of CT in Gas Station and the great majority (82.1%) evaluates the difficulty in if implanting these technologies in Gas Station as being easy or very easy. In the analysis of cluster, it was verified existence of two groupings (as much in the variable of the barriers and benefits), being that inside of each clusters exists homogeneity and between clusters exists heterogeneity. In reality, everything is important or very important in the opinion of the interviewed ones. There only exists a small significant difference that separates them in clusters

Análise textual dos discursos: responsabilidade enunciativa no texto jurídico

This investigation aims at describing, analyzing and interpreting the Commitment in Initial Petitions, which is a genre circumscribed in the judicial domain. For this purpose, we have chosen sections, facts as found and relevant law , sections of the petition, with the understanding that, in this way, respectively, the narration of events, which gives margin to the propositioning to the judicial action, and the exposition of the law that upholds the author s intention. We base our discussion on the field of Linguistics, more precisely, Textual Discourse Analysis (TDA), whose theoretical basis is derived from Textual Linguistics (TL) and Enunciative Linguistics. We foreground, particularly, the way in which the author of texts, objects of analysis, use discursive strategies that evidence ER. The relevance of this study, then, is in the formation of a critique of the judicial text, as it conceives of a dialogical approach to the point of view, raising not only questions about the way in which a linguistic instance conceives an object of discourse, but also considering questions of language inherent to technical writing and, in this aspect, contributing to the work of those operating in Law about the many ways ER is formed in the body of a petition. We selected two categories to analyze that, according to Adam (2011), characterize the degree of ER in the textual material of the propositional enunciations: the different types of representation of speech and the indications of profile of mediators. In this sense, with this task as an objective, we base our study regarding point of view on Rabatel (2003, 2009a, 2010) with relation to the enunciative approach, including the study of PDV in polyphonic and dialogical theoretical framework to study the ER from different types of speech representations that conceive forms of transmission of discourse and the role of the enunciating subject, mainly the responsibility and the prerogative by the propositional contents. In the same way, intending to study the indications of the mediator profiles, we observed the postulations of Guentchéva (1994, 1996), which develop the notion of mediative grammatical categories, of which permit the linguistic marking of distance and engagement of the enunciator with regard to the information expressed. The methodology we adopted was based on qualitative research, of an interpretive and introspective nature, in light of the fact that his study focuses on processes and strategies underlying language use. The corpus of the research is comprised of Initial Petitions, which gave rise to actions originating in the Civil Court of Currais Novos County RN. The data analysis shows that an object of discourse is always perspective oriented and presents the point of view of one or more enunciators. Consequently, the producer of a text, using the PDV of other enunciators, influences and establishes the argumentative orientation of the text. In the same way, it evidences the relevance of the use of mediated constructions in the judicial text, as they function as strategies attenuated to the responsibility of the producer of the text with what is said, and at the same time points to a discourse of authority through the entrance of the sources of law. Moreover, it reveals the documental and international importance of this practice, at the same time that it exposes the compositional and normative difficulties with regard to legal and linguistic aspects

Tecttôniica póss--riifftte na Baciia Pottiiguar

The study of Brazilian sedimentary basins concentrates on their rift phase, whereas the Post-rift phase has been considered a tectonic quiescent period. The post-rift sequence of the Potiguar Basin, in the far northeastern Brazil, was once considered little deformed, however several studies have shown how that it was affected by major fault systems. The purpose of this thesis is to characterize the post-rift tectonic. The specific objectives are: to characterize the Neogene and Quaternary sedimentary units that outcrop of the Potiguar Basin; to show how the NW-SEtrending Afonso Bezerra Faults System deformed outcrop rocks in the Basin; to describe soft-sediment deformation in gravels of the Quaternary Alluvial Deposits from Açu River. Facies analyses, grain-size studies, luminescence dating, remote sensing, structural mapping, shallow geophysics (georadar), paleostress and petrography were carried out. The structural mapping and the georadar sections indicated that the Carnaubais and Afonso Bezerra fault systems formed fractures, silicified and non-silicified faults or deformation bands, affecting mainly the Açu, Jandaíra and Barreiras formations. The petrographic data indicate that the strong silicification resulted in a sealant character of the faults. Paleostress analysis indicates that two stress fields affected the Basin: the first presented N-S-trending compression, occurred from the Neocretaceous to the Miocene; the second stress field presents E-W-trending compression, acts from the Miocene to the present. It was verified once the Afonso Bezerra System Faults was reactivated in periods post-Campanian and affects all post-rift lithostratigraphic units of Potiguar Basin, including Quaternary sedimentary covers. The study about soft-sediment deformation structures indicates that they are similar in morphology and size to modern examples of seismically-induced deformation strutures in coarse sediments. TL and OSL ages indicate that sediment deposition and associated soft-sediment deformation occurred at least six times from ~352 Ka to ~9 Ka. Finally these studies demonstrate how recent is tectonics in the Basin Potiguar

As dunas eólicas de Natal/RN: datação e evolução

The main purpose of this study is to present complementary information on eolian systems that occur in the Center-South portion of the city of Natal, Rio Grande do Norte State, Brazil. The investigation focused on the identification of eolian units, absolute luminescence dating of eolian sediments, to geophysical analysis by Ground Penetrating Radar (GPR), as well as qualitative identification of the use and terrain occupation in the study area. A map was elaborated in order to separate eolian geological units, and describe their deposicional and erosional characteristics, by aerial photo-interpretation. The study lead to the identification of six main units: Unit I - Blowouts (BW), Unit II - Active dunes field (DA), Unit III - Fixed dunes field (DF), Unit IV - Parabolic dunes field (DP), Unit V - Red parabolic dunes field (DV) and Unit VI - Devastated dunes surface (SD). Were analised by Termoluminescense (TL) Method Eight samples from units I, III, IV and V. The largest number of samples with similar or close resulted yielded ages about 15,000 years. Two GPR profiles were obtained in areas of the Dunes Park, near the "Natal s Conventions Center". Results showed the migration a new dune generation over on older one, the geologic contact between dunes and the Formação Barreiras (FB), and the groundwater level inside the dune unit. The qualitative study on the use and terrain occupation of the soil in some dunes fields in the study area, it was possible identify some use and occupation, as the following ones: the construction of residential and commercial buildings, dunes fields cutted for construction to access road and garbage deposition