Síntese de pigmento cerâmico ferrita de cobalto utilizando planejamento experimental

Synthetic inorganic pigments are the most widely used in ceramic applications because they have excellent chemical and thermal stability and also, in general, a lower toxicity to man and to the environment. In the present work, the ceramic black pigment CoFe2O4 was synthesized by the polymerization Complex method (MPC) in order to form a material with good chemical homogeneity. Aiming to optimize the process of getting the pigment through the MPC was used a fractional factorial design 2(5-2), with resolution III. The factors studied in mathematical models were: citric acid concentration, the pyrolysis time, temperature, time and rate of calcination. The response surfaces using the software statistica 7.0. The powders were characterized by thermal analysis (TG/DSC), x-ray diffraction (XRD), scanning electron microscopy (SEM) and spectroscopy in the UV-visible. Based on the results, there was the formation of phase cobalt ferrite (CoFe2O4) with spinel structure. The color of the pigments obtained showed dark shades, from black to gray. The model chosen was appropriate since proved to be adjusted and predictive. Planning also showed that all factors were significant, with a confidence level of 95%

Modelagem e previsão da perda de injetividade em poços canhoneados

Waterflooding is a technique largely applied in the oil industry. The injected water displaces oil to the producer wells and avoid reservoir pressure decline. However, suspended particles in the injected water may cause plugging of pore throats causing formation damage (permeability reduction) and injectivity decline during waterflooding. When injectivity decline occurs it is necessary to increase the injection pressure in order to maintain water flow injection. Therefore, a reliable prediction of injectivity decline is essential in waterflooding projects. In this dissertation, a simulator based on the traditional porous medium filtration model (including deep bed filtration and external filter cake formation) was developed and applied to predict injectivity decline in perforated wells (this prediction was made from history data). Experimental modeling and injectivity decline in open-hole wells is also discussed. The injectivity of modeling showed good agreement with field data, which can be used to support plan stimulation injection wells

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developping the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. Its important to point out that, in spite of the loads being normally connected to the transformers secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Recuperação e purificação de quitosanases usando adsorção em leito expandido com streamline DEAE com modelagem e simulação usando redes neurais

Expanded Bed Adsorption (EBA) is an integrative process that combines concepts of chromatography and fluidization of solids. The many parameters involved and their synergistic effects complicate the optimization of the process. Fortunately, some mathematical tools have been developed in order to guide the investigation of the EBA system. In this work the application of experimental design, phenomenological modeling and artificial neural networks (ANN) in understanding chitosanases adsorption on ion exchange resin Streamline® DEAE have been investigated. The strain Paenibacillus ehimensis NRRL B-23118 was used for chitosanase production. EBA experiments were carried out using a column of 2.6 cm inner diameter with 30.0 cm in height that was coupled to a peristaltic pump. At the bottom of the column there was a distributor of glass beads having a height of 3.0 cm. Assays for residence time distribution (RTD) revelead a high degree of mixing, however, the Richardson-Zaki coefficients showed that the column was on the threshold of stability. Isotherm models fitted the adsorption equilibrium data in the presence of lyotropic salts. The results of experiment design indicated that the ionic strength and superficial velocity are important to the recovery and purity of chitosanases. The molecular mass of the two chitosanases were approximately 23 kDa and 52 kDa as estimated by SDS-PAGE. The phenomenological modeling was aimed to describe the operations in batch and column chromatography. The simulations were performed in Microsoft Visual Studio. The kinetic rate constant model set to kinetic curves efficiently under conditions of initial enzyme activity 0.232, 0.142 e 0.079 UA/mL. The simulated breakthrough curves showed some differences with experimental data, especially regarding the slope. Sensitivity tests of the model on the surface velocity, axial dispersion and initial concentration showed agreement with the literature. The neural network was constructed in MATLAB and Neural Network Toolbox. The cross-validation was used to improve the ability of generalization. The parameters of ANN were improved to obtain the settings 6-6 (enzyme activity) and 9-6 (total protein), as well as tansig transfer function and Levenberg-Marquardt training algorithm. The neural Carlos Eduardo de Araújo Padilha dezembro/2013 9 networks simulations, including all the steps of cycle, showed good agreement with experimental data, with a correlation coefficient of approximately 0.974. The effects of input variables on profiles of the stages of loading, washing and elution were consistent with the literature

Comparação entre planejamento estatístico experimental e análise dimensional em operações de mistura e separação para sistema óleo-água

This work aims to determine a better methodology to help predicting some operational parameters to a new design of mixer-settler on treating wastewater produced by petroleum industry, called MDIF (Misturador-Decantador à Inversão de Fases/ Mixer-Settler based on Phase Inversion MSPI). The data from this research were obtained from the wastewater treatment unit, called MSPI-TU, installed on a wastewater treatment plant (WTP) of PETROBRAS/UO-RNCE. The importance in determining the better methodology to predict the results of separation and extraction efficiency of the equipment, contributes significantly to determine the optimum operating variables for the control of the unit. The study was based on a comparison among the experimental efficiency (E) obtained by operating MSPI-TU, the efficiency obtained by experimental design equation (Eplan) from the software Statistica Experimental Design® (version 7.0), and the other obtained from a modeling equation based on a dimensional analysis (Ecalc). The results shows that the experimental design equation gives a good prediction of the unit efficiencies with better data reliability, regarding to the condition before a run operation. The average deviation between the proposed by statistic planning model equation and experimental data was 0.13%. On the other hand, the efficiency calculated by the equation which represents the dimensional analysis, may result on important relative deviations (up 70%). Thus, the experimental design is confirmed as a reliable tool, with regard the experimental data processing of the MSPI-TU

Influência dos modelos digitais de terreno na modelagem de circulação hidrodinâmica 2DH: um estudo de caso

Digital Elevation Models (DEM) are numerical representations of a portion of the earth surface. Among several factors which affect the quality of a DEM, it should be emphasized the attention on the input data and the choice of the interpolating algorithm. On the other hand, several numerical models are used nowadays to characterize nearshore hydrodynamics and morphological changes in coastal areas, whose validation is based on field data collection. Independent on the complexity of the physical processes which are modeled, little attention has been given to the intrinsic bathymetric interpolation built within the numerical models of the specific application. Therefore, this study aims to investigate and to quantify the influence of the bathymetry, as obtained by a DEM, on the hydrodynamic circulation model at a coastal stretch, off the coast of the State of Rio Grande do Norte, Northeast Brazil. This coastal region is characterized by strong hydrodynamic and littoral processes, resulting in a very dynamic morphology with shallow coastal bathymetry. Important economic activities, such as oil exploitation and production, fisheries, salt ponds, shrimp farms and tourism, also bring impacts upon the local ecosystems and influence themselves the local hydrodynamics. This fact makes the region one of the most important for the development of the State, but also enhances the possibility of serious environmental accidents. As a hydrodynamic model, SisBaHiA® - Environmental Hydrodynamics System ( Sistema Básico de Hidrodinâmica Ambiental ) was chosen, for it has been successfully employed at several locations along the Brazilian coast. This model was developed at the Coastal and Oceanographical Engineering Group of the Ocean Engineering Program at the Federal University of Rio de Janeiro. Several interpolating methods were tested for the construction of the DEM, namely Natural Neighbor, Kriging, Triangulation with Linear Interpolation, Inverse Distance to a Power, Nearest Neighbor, and Minimum Curvature, all implemented within the software Surfer®. The bathymetry which was used as reference for the DEM was obtained from nautical charts provided by the Brazilian Hydrographic Service of the Brazilian Navy and from a field survey conducted in 2005. Changes in flow velocity and free surface elevation were evaluated under three aspects: a spatial vision along three profiles perpendicular to the coast and one profile longitudinal to the coast as shown; a temporal vision from three central nodes of the grid during 30 days; a hodograph analysis of components of speed in U and V, by different tidal cycles. Small, but negligible, variations in sea surface elevation were identified. However, the differences in flow and direction of velocities were significant, depending on the DEM

Diversificação cariotípica em cinco espécies de moréias do Atlântico Ocidental (Anguilliformes)

The Anguiliformes is constituted by 15 families, 141 sorts and 737 species. In this group eight families possess at least one karyotyped species, where a prevalence of karyotypes with 2n=38 is evidenced chromosomes and high NF, apparently basal for the Anguiliformes. The only family who shows a different karyotypic pattern from the others is the Muraenidae family. In this, of the eight species already described, all of them present 2n=42 chromosomes. Despite the dimension of this Order, few species present karyotypics descriptions. In the present work, a species of Ophichthidae, Myrichthys ocellatus (2n=38, 8m+14sm+10st+6a, NF=70) and three species of Muraenidae, Enchelycore nigricans (2n=42, 6m+8sm+12st+16a, NF=68), Gymnothorax miliaris (2n=42, 14m+18sm+10st, NF=84), Gymnothorax vicinus (2n=42, 8m+6sm+28a, NF=56) and Muraena pavonina (2n=42, 6m+4sm+32a, NF=52), collected in the coast of the Rio Grande do Norte state, Saint Peter and Paul Rocks and in the coast of Bahia state were analyzed. Mitotics chromosomes had been gotten through mitotic stimulation with yeasts. Among the analyzed species, it is observed the presence of characteristic large metacentric chromosomic pairs (≅10µm). As for the structural standard, heterochromatics regions in these species in centromeric position of the majority of the chromosomic pairs and simple ribosomal sites had been evidenced. For the Ophichthidae family, the gotten data corroborate the hypothesis of karyotypic diversification mediated by the occurrence of pericentrics inversions and robertsonians rearrangements, while in the Muraenidae, the identification of larger chromosomic values (2n=42), suggests derived karyotypes, possibly caused by possible chromosomic fissions

Zoneamento geoambiental como subsídio ao planejamento territorial municipal: estudo de caso para Currais Novos/RN

This paper presents the master plan and geoenvironmental zoning natures as instruments of environmental planning and management. The discussion of territory environmental planning is guided by two directions: at first the environmental elements involved in planning and the another is the implementation of these instruments at the municipal territory. To analyze the planning directed of the municipal territory we consider the fragments of its, represented by country and urban. The master plan inside of the Estatuto da Cidade (City Statute) and the geoenvironmental zoning are directed to territorial environmental planning. Regarding of the master plan the first challenge has been the spacial area that the plan can cover. It is necessary to prepare master plans that could include all the territory. The environmental zoning are directed for the territory totality.In this sense, the geoenvironmental zoning of the Currais Novos was done in the totality of the municipal territory and guided by the environmental physics variables. The geoenvironmental zoning sets in a planning and ordering of the territory instrument based in the landscape analysis. Therefore grounded in the Geosystems‟s Theory this work has like a main objective to propose a geoenvironmental zoning for the Currais Novos Municipality in RN. So, was used an analysis technique suggested for Bardin (2010) and the Currais Novos‟s physical environment characterization through of the fieldwork and cartographic data vectorization, beyond the image‟s treatment SRTM. The geoenvironmental systems definitions were based in the suggestion of Cestaro, et al. (2007) support in Bertrand (1968). For both were identified five geoenvironmental systems: Borborema Plateau, Residual plateau, Chapada da Serra de Santana, semiarid river valley and lagoon valley and eleven geoenvironmental subsystems: Borborema Plateau Western Slope, Isolated Massif of the Borborema Plateau, Residual Crest, Residual Massif, Erosional Scarp of the Chapada, flat top plateau, fluvial plains, temporary river of the semiarid and ornamental water or sluice

Caracterização geomorfológica e modelagem de dados espaciais na plataforma continental rasa do RN nos limites da folha Touros

This work focuses the geomorphological characterization and spatial data modeling in the shallow continental shelf within the Folha Touros limits (SB-25-CV-II), based on bathymetric data analysis and remote sensing products interpretation. The Rio Grande do Norte state is located in northeastern Brazil and the work area is located at the transition region between the eastern and northern portions of their coast. The bathymetric surveys were conduced between march and may 2009, using a 10 meters long vessel and 0.70 meters draught, equipped with global positioning system and echo sounder (dual beam, 200KHz , 14°). The fieldwork resulted in 44 bathymetric profiles espaced 1.5 km and 30 km average length. The bathymetric data amount were 111,200 points and were navigated 1395.7 km within na area about 1,850 km2. The bathymetric data were corrected for the tide level, vessel draught and were subsequently entered into a geographic information system for further processing. Analysis of remote sensing products was carried out using Landsat 7/ETM + band 1, from november 1999. The image was used for visualization and mapping submerged features. The results showed the presence of geomorphological features within the study area. Were observed, from the analysis of local bathymetry and satellite image, seven types of geomorphological features. The channels, with two longitudinals channels (e. g. San Roque and Cioba channels) and other perpendicular to the coast (e. g. Touros, Pititinga and Barretas). Coastal reef formations (Maracajaú, Rio do Fogo and Cioba). Longitudinal waves, described in the literature as longitudinal dunes. The occurrence of a transverse dune field. Another feature observed was the oceanic reefs, an rock alignment parallel to the coast. Were identified four riscas , from north to south: risca do Liso, Gameleira, Zumbi, Pititinga (the latter being described for the first time). Finally, an oceanic terrace was observed in the deepest area of study. Image interpretation corroborated with the in situ results, enabling visualization and description for all features in the region. The results were analysed in an integrating method (using the diferent methodologies applied in this work) and it was essential to describe all features in the area. This method allowed us to evaluate which methods generated better results to describe certain features. From these results was possible to prove the existence of submerged features in the eastern shallow continental shelf of Rio Grande do Norte. In this way, the conclusions was (1) this study contributed to the provision of new information about the area in question, particularly with regard to data collection in situ depths, (2) the method of data collection and interpretation proves to be effective because, through this, it was possible to visualize and interpret the features present in the study area and (3) the interpretation and discussion of results in an integrated method, using different methodologies, can provide better results

Caracterização geológica tridimensional e monitoramento de dunas no litoral oriental do Rio Grande do Norte

This work presents geophysical and geological results obtained in a dunefield located in the east coast of Rio Grande do Norte State, with the aim to recognize the aeolian body depositional geometries to a future geologic modeling of the aeolian petroliferous reservoirs. The research, which was done in blowouts region situated at Nisia Floresta Municipally, included the characterization of external geometries with GPS and internal geometry analysis by GPR. Data was integrated in GoCAD software, where it was possible the three-dimensional characterization and interpretation of the studied deposits. The interpretation of GPR profiling allowed identifying: First-order bounding surfaces that separated the aeolian deposits of the Barreiras Formation rocks; Second-order bounding surfaces, which limit dune generations and Third-order bounding surfaces, a reactivation surface. This classification was based and adapted by the Brookfield (1977) and Kocurek (1996) propose. Four radarfacies was recognized: Radarfacies 1, progradational reflectors correlated to foresets of the dunes, Radarfacies 2, plain parallels reflectors related to sand sheets, Radarfacies 3, plain parallels reflectors associated to reworking of the blowout dune crest and Radarfacies 4, mounded reflectors associated to vegetated mound of sand or objects buried in subsurface. The GPR and GPS methods was also employed to the monitoring of dunefields susceptible to human activities in Buzios Beach, where the constructions along the blowout region and the tourism are changing the natural evolution of the deposits. This fact possibly to cause negative impacts to the coastal zone. Data obtained in Dunas Park, a unit environmental conservation, was compared with information of the Buzios Beach. There is a major tendency of erosion in Buzios, specifically in blowout corridor and blowout dune

Políticas de turismo e comunidade local no litoral potiguar

This research focuses on raise the discussion of existance tourism policies in Rio Grande do Norte and its contributions to the integration of local communities in the coastal tourist activity. Guided by the background of the neoliberalism and its influence on the model of tourism development adopted in Rio Grande do Norte. For that, were surveyed the concrete realities of coastal localities of the municipalities of Ceará-Mirim, Extremoz, Parnamirim and Nísia Floresta covered by Prodetur-RN I and II, by being part of the tourist portion of the state that have received domestic and international investment and, because are located in the geographical area of the Potiguar capital, Natal. We interviewed the municipal managers and the residents of local communities who live in municipalities more than ten years. Also, was raised a discussion on the role of the state as the main agent of public policies and hegemonic facilitator in the attraction of domestic and foreign investments, with the main scenario the neoliberal model of economic development. Here discuss ways and strategies of socio-political organization of local communities, with regard to the inclusion in the tourist and, pointing to the critical development model in question and signaling other concepts of development model, such as local basis, for example. By the ending of the research, was concluded that the model of development of the tourism in the Rio Grande do Norte is reflected of the way of life of the society, that the communities live in precarious conditions and that the way of inclusion in the tourism is almost incipient. Also, it was possible to detect the inexistence of public politics of tourism that promoted the planning of the tourist activity, as well as, the inclusion of the communities in the decision processes and that, searched the development on the basis of the principles of sustainable and local autonomy

Geografia, turismo e meio ambiente: uma nova face do litoral dos municípios de Extremoz e Ceará-Mirim

La presente pesquisa contempla reflexiones referentes de la actividad turística en la organización socio-espacial en el litoral de las comarcas de Extremoz y Ceará-Mirim, región de la Grande Natal. Nuestro objetivo principal es el estudio de las transformaciones del espacio y de sus implicaciones socio-ambientales en curso en el proceso de producción del espacio turístico en el litoral de las referidas comarcas desde 1997 hasta 2007, momento de importancia publica-privada que, a partir del PRODETUR, tuvo la base para el incremento de las potencialidades turísticas. En este sentido, varias fueron las técnicas para una mejor compresión de las aspiraciones y de la percepción de los actores envueltos con la actividad turística (comerciantes, turistas, populación y poder publico local) para conocer cuales son sus consideraciones en cuanto a los cambios que proceden de la implantación de la actividad turística en el lugar, cuanto a la mejora de la calidad de vida, de la generación de empleo y de renta, comercialización, conservación, preservación del ambiente, cumplimiento de la legislación, afirmación cultural así como las acciones puestas en ejecución en las comarcas. Para tal necesidad, se buscó analizar los datos estadísticos a partir del uso de los cuestionarios con preguntas estructuradas y semi-abiertas como instrumento de colecta de información que les era correlacionada con la opinión de los actores locales de modo que podamos formar y entender los elementos básicos que son parte de los espacios turísticos en foco. Fueran utilizadas fotografías aéreas de las comarcas de Extremoz y Ceará-Mirim, provistas por el IDEMA, con la intención de percibir acerca de los cambios del espacio y las implicaciones socio-ambientales de la área en estudio. Concluimos en función de los resultados que el modelo de Turismo concebido por lo Brasil, estimulado y financiado por lo Gobierno Federal, está insertado en el contexto de la economía global y, por lo tanto, el Estado del Rio Grande del Norte, en específico los espacios litoraneos de las comarcas de Extremoz y Ceará-Mirim, que poseen características similares a este modelo, con sus particularidades, que si traduzca por la exclusión social, formas de apropiación privada de los espacios público y áreas de protección ambiental como las playas, las dunas y las lagunas, el desacato o no el cumplimiento de la legislación ambiental, aumento de las desigualdad de renta en una región que posee una problemática social grave y sin inversión, implantación de la infraestructura, ausencia de política pública local, donde los intereses económicos son prioridad delante de las aclamaciones populares. Se sugiere un repensar cuanto al modelo actual de desarrollo adoptado, que el planeamiento sea pautado en base a la participación integrada de los varios agentes implicados con la actividad turística, incluyendo en la medida del posible, las aspiraciones de la población local como precusoras de sus reales necesidades, donde esta acción interactiva contestará ciertamente en un esfuerzo significativo en la construcción de un nuevo paradigma, modelo del desarrollo sustentable, siendo posible superar gradualmente el incremento de la pobreza, de la exclusión y de los impactos ambientales, donde la calidad de vida sea factor fundamental

Dinâmica ambiental da planície de deflação do litoral de Extremoz / RN e influência das normativas legais no processo de organização territorial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Cetacean records along São Paulo state coast, Southeastern Brazil

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

Detecção de prováveis deformações neotectônicas no Vale do Rio do Peixe, Região Ocidental Paulista, mediante aplicaçao de Índices RDE (Relac̈ão Declividade-Extensão) em segmentos de drenagem

Running water is one of the most important of all the physical processes which fashion the landscape, allowing gravity to operate along the valley floors. Besides this, the streams show a fast adjustment to the crustal deformations, even to the most gentle ones. This geologic behavior turns them a potential tool for neotectonic studies, specially the analysis of morphotnetric parameters associated with hydraulic gradient and discharge, this second factor being directly proportional to the extension of the streams. Both elements, gradient and stream length, can be combined in the SL index. The purpose of this paper is to show the RDE index application in the neotectonics analysis of the Rio do Peixe hydrographic basin and to compare the obtained values with the geologic basement incised by the streams. This basement encompasses Cretaceous sedimentary rocks of post-Serra Oeral Formation magmatism (Caiuá and Bauru groups) and Quaternary deposits that include chiefly recent alluvial plains and some Pleistocene terrace deposits. In the final part of this paper, an attempt is made in order to correlate the RDE results and the neotectonic framework admitted to this portion of the São Paulo State territory, as well as with field geologic, seismologic and paleoseismologic known elements. The results indicate the presence of two groups of anomalies: The first set corresponds to the Marília-Exaporã Plateau border, and the second one, located in the central portion of the hydrographic basin, is correlated to the Presidente Prudente seimogenic zone.