8 resultados para Perfil Elétrico de Densidade (RHOB)

em Universidade Federal do Rio Grande do Norte(UFRN)


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In recent years, the DFA introduced by Peng, was established as an important tool capable of detecting long-range autocorrelation in time series with non-stationary. This technique has been successfully applied to various areas such as: Econophysics, Biophysics, Medicine, Physics and Climatology. In this study, we used the DFA technique to obtain the Hurst exponent (H) of the profile of electric density profile (RHOB) of 53 wells resulting from the Field School of Namorados. In this work we want to know if we can or not use H to spatially characterize the spatial data field. Two cases arise: In the first a set of H reflects the local geology, with wells that are geographically closer showing similar H, and then one can use H in geostatistical procedures. In the second case each well has its proper H and the information of the well are uncorrelated, the profiles show only random fluctuations in H that do not show any spatial structure. Cluster analysis is a method widely used in carrying out statistical analysis. In this work we use the non-hierarchy method of k-means. In order to verify whether a set of data generated by the k-means method shows spatial patterns, we create the parameter Ω (index of neighborhood). High Ω shows more aggregated data, low Ω indicates dispersed or data without spatial correlation. With help of this index and the method of Monte Carlo. Using Ω index we verify that random cluster data shows a distribution of Ω that is lower than actual cluster Ω. Thus we conclude that the data of H obtained in 53 wells are grouped and can be used to characterize space patterns. The analysis of curves level confirmed the results of the k-means

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In recent years, the DFA introduced by Peng, was established as an important tool capable of detecting long-range autocorrelation in time series with non-stationary. This technique has been successfully applied to various areas such as: Econophysics, Biophysics, Medicine, Physics and Climatology. In this study, we used the DFA technique to obtain the Hurst exponent (H) of the profile of electric density profile (RHOB) of 53 wells resulting from the Field School of Namorados. In this work we want to know if we can or not use H to spatially characterize the spatial data field. Two cases arise: In the first a set of H reflects the local geology, with wells that are geographically closer showing similar H, and then one can use H in geostatistical procedures. In the second case each well has its proper H and the information of the well are uncorrelated, the profiles show only random fluctuations in H that do not show any spatial structure. Cluster analysis is a method widely used in carrying out statistical analysis. In this work we use the non-hierarchy method of k-means. In order to verify whether a set of data generated by the k-means method shows spatial patterns, we create the parameter Ω (index of neighborhood). High Ω shows more aggregated data, low Ω indicates dispersed or data without spatial correlation. With help of this index and the method of Monte Carlo. Using Ω index we verify that random cluster data shows a distribution of Ω that is lower than actual cluster Ω. Thus we conclude that the data of H obtained in 53 wells are grouped and can be used to characterize space patterns. The analysis of curves level confirmed the results of the k-means

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The study of complex systems has become a prestigious area of science, although relatively young . Its importance was demonstrated by the diversity of applications that several studies have already provided to various fields such as biology , economics and Climatology . In physics , the approach of complex systems is creating paradigms that influence markedly the new methods , bringing to Statistical Physics problems macroscopic level no longer restricted to classical studies such as those of thermodynamics . The present work aims to make a comparison and verification of statistical data on clusters of profiles Sonic ( DT ) , Gamma Ray ( GR ) , induction ( ILD ) , neutron ( NPHI ) and density ( RHOB ) to be physical measured quantities during exploratory drilling of fundamental importance to locate , identify and characterize oil reservoirs . Software were used : Statistica , Matlab R2006a , Origin 6.1 and Fortran for comparison and verification of the data profiles of oil wells ceded the field Namorado School by ANP ( National Petroleum Agency ) . It was possible to demonstrate the importance of the DFA method and that it proved quite satisfactory in that work, coming to the conclusion that the data H ( Hurst exponent ) produce spatial data with greater congestion . Therefore , we find that it is possible to find spatial pattern using the Hurst coefficient . The profiles of 56 wells have confirmed the existence of spatial patterns of Hurst exponents , ie parameter B. The profile does not directly assessed catalogs verification of geological lithology , but reveals a non-random spatial distribution

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The study of complex systems has become a prestigious area of science, although relatively young . Its importance was demonstrated by the diversity of applications that several studies have already provided to various fields such as biology , economics and Climatology . In physics , the approach of complex systems is creating paradigms that influence markedly the new methods , bringing to Statistical Physics problems macroscopic level no longer restricted to classical studies such as those of thermodynamics . The present work aims to make a comparison and verification of statistical data on clusters of profiles Sonic ( DT ) , Gamma Ray ( GR ) , induction ( ILD ) , neutron ( NPHI ) and density ( RHOB ) to be physical measured quantities during exploratory drilling of fundamental importance to locate , identify and characterize oil reservoirs . Software were used : Statistica , Matlab R2006a , Origin 6.1 and Fortran for comparison and verification of the data profiles of oil wells ceded the field Namorado School by ANP ( National Petroleum Agency ) . It was possible to demonstrate the importance of the DFA method and that it proved quite satisfactory in that work, coming to the conclusion that the data H ( Hurst exponent ) produce spatial data with greater congestion . Therefore , we find that it is possible to find spatial pattern using the Hurst coefficient . The profiles of 56 wells have confirmed the existence of spatial patterns of Hurst exponents , ie parameter B. The profile does not directly assessed catalogs verification of geological lithology , but reveals a non-random spatial distribution

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Peng was the first to work with the Technical DFA (Detrended Fluctuation Analysis), a tool capable of detecting auto-long-range correlation in time series with non-stationary. In this study, the technique of DFA is used to obtain the Hurst exponent (H) profile of the electric neutron porosity of the 52 oil wells in Namorado Field, located in the Campos Basin -Brazil. The purpose is to know if the Hurst exponent can be used to characterize spatial distribution of wells. Thus, we verify that the wells that have close values of H are spatially close together. In this work we used the method of hierarchical clustering and non-hierarchical clustering method (the k-mean method). Then compare the two methods to see which of the two provides the best result. From this, was the parameter � (index neighborhood) which checks whether a data set generated by the k- average method, or at random, so in fact spatial patterns. High values of � indicate that the data are aggregated, while low values of � indicate that the data are scattered (no spatial correlation). Using the Monte Carlo method showed that combined data show a random distribution of � below the empirical value. So the empirical evidence of H obtained from 52 wells are grouped geographically. By passing the data of standard curves with the results obtained by the k-mean, confirming that it is effective to correlate well in spatial distribution

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The present study aimed to characterize the thermal profile of wood fired oven used by the red ceramic industry in Parelhas, in the Seridó region/RN, aiming to propose structural interventions that can contribute to increasing productivity and product quality, optimize wood consumption and mitigate existing losses during the burning process. The study was conducted at Cerâmica Esperança in the city of Parelhas -RN, Brazil, during the period from August 2012 to September 2013. Four treatments were performed with three replicates, ie, with, a total of 12 experimental units (burnings). In the first stage 4 treatments were performed with three replicates, totaling 12 experimental units (firings). In the second stage 2 treatments were performed with three replications, totaling 6 experimental units (firings). The physical characteristics of the wood were analyzed using standard NBR 11941 and NBR 7190 for basic density and moisture, respectively. The clay was used as a reference parameter for distinguishing treatments. For both the analysis and characterization was carried out using techniques of fluorescence X (XRF) rays, X-ray diffraction (XRD) analysis, particle size analysis (FA). In the first and second stages were monitored: the time during the firing process, the amount of wood used at each firing, the number of parts enfornadas for subsequent determination of the percentages of losses, but also product quality. To characterize the thermal profile of the oven, we measured the temperature at 15 points scored in the surface charge put into the oven. Measurements were taken every 30 minutes from preheat until the end of burning, using a pyrometer laser sight sighting from preheating until the end of burning. In the second step 12 metal cylinders distributed on the oven walls, and the cylinder end walls 8 of the furnace 2 and rollers on each side walls are installed equidistant to 17 cm from the soil and the surface 30 of the wall are installed. The cylinders distributed on the front were placed 50 cm above the furnace, and the base of the oven 20 cm distant from the ground. 10 also thermocouples were installed, and five thermocouples distributed 1.77 cm above the combustion chambers, and one thermocouple on each side, and three thermocouples in front of the oven. We carried out the measurements of the temperatures every 1 hour during the burning two hours in cooling the cylinders with a pyrometer and thermocouples for dattaloger. These were fixed with depth of 30 cm from the wall. After statistical analysis it was found that: the thermal profile of the furnace surface and at different heights was heterogeneous; and the ranges of density and moisture content of wood are within recommended for use as an energy source standards. We conclude that even at low temperatures reached during firing there was a significant production of good quality products, this is due to high concentrations of iron oxide and potassium oxide found in clay, which lowers the melting point of the piece. The average burn time for each step varied 650-2100 minutes wood consumption was on average 20 m3, product quality was on average 16% of first quality, 70% second, third and 5% to 10% loss . The distance between the wire and the surface of the oven was a significant parameter for all treatments, but with different variations, meaning that the wire should not be so generic and unique form, used as a criterion for completion of the burn process. The central part of the furnace was the area that reached higher temperature, and in a unified manner, with the highest concentration of top quality products. The ideal temperature curve, which provided the highest quality of ceramic products was achieved in the central part of the furnace

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One of the factors that may interfere with the cultivation of Litopenaeus vannamei is the population density. This study aimed to assess the effect of density on growth, mortality, physical integrity and behavior of shrimp. The study was divided into two stages. At first, the shrimp were placed in tanks at densities of 50, 75 and 100 shrimp m-2. The animals were monitored in relation to the degree of proventricular filling, the stage of the molt cycle and physical integrity three times a week and in relation to the weight and length once a week. Mortality, growth and proventricular filling were not influenced by the density; frequency of records in specific stages of the molt cycle varied according to the density. The lower proportion of broken appendages and higher frequency of necrotic lesions occurred in lower density. The second stage of the research, conducted in aquaria, was divided into two parts. The first described social or feeding behavioral categories: slow displacement by contact, slow displacement by approximation, abrupt displacement by contact, abrupt displacement by approximation, reactivity, cannibalism, occupying the tray, get feed in the tray and get feed outside the tray. In the second part, these and other behavioral categories, described in the literature, were recorded in densities of 50, 75 and 100 shrimp m-2. Mortality was more frequent in higher density. The frequency of most behaviors mentioned above was very low, not differing between densities or being too low to determine differences between them. The behavioral profile of animals in different densities was, in general, very similar, with no difference in exploration, digging and cleaning between the densities. Even so, inactivity, feeding, crawling, burrowing, swimming, and proximity between animals were influenced by the density. These results suggest that some behaviors suffer greater interference from population density. However, the density may not have a broader influence on the animals when other factors, such as physico-chemical parameters of water and feed offering, are adequate

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The development of computers and algorithms capable of making increasingly accurate and rapid calculations as well as the theoretic foundation provided by quantum mechanics has turned computer simulation into a valuable research tool. The importance of such a tool is due to its success in describing the physical and chemical properties of materials. One way of modifying the electronic properties of a given material is by applying an electric field. These effects are interesting in nanocones because their stability and geometric structure make them promising candidates for electron emission devices. In our study we calculated the first principles based on the density functional theory as implemented in the SIESTA code. We investigated aluminum nitride (AlN), boron nitride (BN) and carbon (C), subjected to external parallel electric field, perpendicular to their main axis. We discuss stability in terms of formation energy, using the chemical potential approach. We also analyze the electronic properties of these nanocones and show that in some cases the perpendicular electric field provokes a greater gap reduction when compared to the parallel field