8 resultados para splitting

em Universidade Federal do Rio Grande do Norte(UFRN)


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Novel cementing materials formulations containing flexible polymeric admixtures have been studied aiming at improving the mechanical behavior of oil well cement slurries submitted to steam injection. However, research activities in this sector are still under development. The steam injected directly into the well causes casing dilation, which after a reduction in temperature, tends to return to its original dimensions, resulting in crack formation and hydraulic isolation loss of the well, which will result in shortening of well life. In this scenario, the objective of the present study was to evaluate the mechanical behavior of Portland-based slurries containing SBR latex, applied in oil well cementing of wells submitted to steam injection. Were formulated slurries with densities of 1.797 g/cm3 (15.0 lb/Gal) and 1.869 g/cm3 (15.6 lb/Gal), containing admixtures with a latex concentration of 0; 66.88; 133.76; 200.64 and 267.52 L/m3 (0, 0.5, 1.0, 1.5 and 2.0 gpc). Tests including rheology, fluid loss control, thickening time, API compressive strength and splitting tensile strength, beyond steam injection simulation. Microstrutural characteristics of the slurries were also performed (XRD, TG, FTIR and SEM). The results showed that increasing the polymer concentration increased in the rheological properties and fluid loss, and a decrease in the elasticity modulus of the cement slurries. The results obtained showed that the slurries can be applied in cementing operations of oil wells submitted to steam injection.

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This paper focuses on a study of public policy jurisdictional control as some effectiveness mechanism for cultural, economical, and social fundamental rights. It investigates the juridical profile of public policies based on premises of the current (Neo)Constitutional State model and the assertion of an essentially constitutionalist Law paradigm from its genesis to its most peculiar elements, and through tormenting issues, such as: its position between Law and Politics, the difference with reflective subjective rights, and the problem of high financial costs. Once its object is identified, it moves forward into the theme itself, which is that of jurisdictional control, investigating its legitimacy based on paradigmatic judicial precedents and the facing of themes such as: current role of the Judicial Power, the splitting of state functions, administrative discretion, financial affordability, illegal omissions, and budget control. Finally, it examines, as its study central object, objective parameters for definition control, execution, and transparency of public policies, as well as identifying the most appropriate collective jurisdictional tutoring to its purposes together with some of its law process means. Therefrom, it shows new perspectives for the recent study on jurisdictional control of public policies, building foundations for the fundamental rights effectiveness

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This study - Biologist s formative speech about death. Nuances and metaphors from knowing that the subject of do not want to know - shows a marginal cognitive construction in scientific education from biologist - death. It considered as obvious that death is a theme that covers both the scientific education from biologist and the division of the subject, and concerns the splitting of the double life-death and the principles of inclusion and exclusion of the subject. Part of sensitive question: What is the epistemological weave who supports biologist's speech about death? It is constituted an object of study of the biologist s speech on death. It is advocated the thesis that: Death is an epistemological obstacle announcing for something always aims to escape from the perspective of knowledge, especially of scientific knowledge because, since it is understood as cognitive learning about the disruption of biological phenomenon life which is involved on weave of imaginary and symbolic constructions about the finiteness of life; it has constituted a metaphorical knowing - encouraged by the noisy silence - which does not allow to know in full, mobilizing hence subject in searching for transitional truths that reduce the ontological being-mortal anguish centered in subjective dimension involved in the act of knowing. From this movement of search that the object mental life after death wins a symbolic value that requires a real-looking multi-referential for the study of biology - life - and its implications: the finiteness of life, especially by moving the omnipotence of scientific objectivity expressed by signs and symbols that seek say the completeness of scientific knowledge-, signaling thus the existence of the dynamics of incompleteness implicit in subjectivity that supports knowledge relating to the double, life and death, and to the temporality of the existence of Homo sapiens sapiens, with the axis guiding the desire of the subject, do not want to know about death, implicit in the mechanisms objective-subjective founded by non-said of death is the epistemology of the existence of objective-subjective subject, whose core is the negation of death. The theoretical methodological knowing web is anchored in the multi-reference which favors a transit by theoretical current, as the Psychoanalysis, bachelardian philosophy, the epistemology of complexity, the Thanatology, the Social Psychology, and Etnocenology, and Understanding Interview. The unveiling of the study object from the analysis of oral speech of eleven biologists who serve in high school, from three main guiding: Death in the history of life,Death in biologist s academic education and, Conceptions about concepts

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Eventually, violations of voltage limits at buses or admissible loadings of transmission lines and/or power transformers may occur by the power system operation. If violations are detected in the supervision process, corrective measures may be carried out in order to eliminate them or to reduce their intensity. Loading restriction is an extreme solution and should only be adopted as the last control action. Previous researches have shown that it is possible to control constraints in electrical systems by changing the network topology, using the technique named Corrective Switching, which requires no additional costs. In previous works, the proposed calculations for verifying the ability of a switching variant in eliminating an overload in a specific branch were based on network reduction or heuristic analysis. The purpose of this work is to develop analytical derivation of linear equations to estimate current changes in a specific branch (due to switching measures) by means of few calculations. For bus-bar coupling, derivations will be based on short-circuit theory and Relief Function methodology. For bus-bar splitting, a Relief Function will be derived based on a technique of equivalent circuit. Although systems of linear equations are used to substantiate deductions, its formal solution for each variant, in real time does not become necessary. A priority list of promising variants is then assigned for final check by an exact load flow calculation and a transient analysis using ATP Alternative Transient Program. At last, results obtained by simulation in networks with different features will be presented

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This work has the general proposal of studying the composition of the trevisanian fictional universe, the aesthetic expression engineered to formulate this universe, and last, the representations of reality that emanates from this aesthetic-narrative construction. It seemed to us, however, that it would be impossible to cover, even superficially, so vast and voluminous set of texts as the trevisanian. Therefore, so that we could accomplish this task, and still do it in a way that was, at the same time, plausible and thorough, it was necessary an objective cut within that library. Then we selected a book, representative of the whole trevisanian work, which served as the object of study: Cemitério de Elefantes, 1964, one of the first books of short stories by this author. Within this one, we focused even more our sight, then moving towards what we call a reality forked in paralytic world and world in violence . Supported by the theories and methodologies of Auerbach (2011), Candido (2002, 2006), Adorno (2003), Gennete (1995), Friedman (2002), and still moved by the spirit of Russian Formalism (1973), we built our criticism. Our approach was based then in three steps: first we are dedicated to comment the general context of the trevisanian work, supported strongly by reading two of the biggest critics of his literature, Miguel Sanches Neto and Berta Waldman, secondly, we turn us to comment on the detailed formal construction of language and narrative elements of the trevisanian prose; finally we raised our criticism to the level of reading representations of reality, and then we started to comment the construction of the trevisanian fictional universe, focusing in splitting this universe in paralytic world and world in violence

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This paper proposes a new control chart to monitor a process mean employing a combined npx-X control chart. Basically the procedure consists of splitting the sample of size n into two sub-samples n1 and n2 determined by an optimization search. The sampling occur in two-stages. In the first stage the units of the sub-sample n1 are evaluated by attributes and plotted in npx control chart. If this chart signs then units of second sub-sample are measured and the monitored statistic plotted in X control chart (second stage). If both control charts sign then the process is stopped for adjustment. The possibility of non-inspection in all n items may promote a reduction not only in the cost but also the time spent to examine the sampled items. Performances of the current proposal, individual X and npx control charts are compared. In this study the proposed procedure presents many competitive options for the X control chart for a sample size n and a shift from the target mean. The average time to sign (ATS) of the current proposal lower than the values calculated from an individual X control chart points out that the combined control chart is an efficient tool in monitoring process mean.

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This dissertation presents a study on crustal seismic anisotropy in Cascavel - CE. The earthquake data employed here are from the Seismological Laboratory at Universidade Federal do Rio Grande do Norte (UFRN) and were colected from 29 September 1997 to 05 march 1998 using six three-component digital seismographic stations. In general, the cause of the observed seismic anisotropy in many regions of the world is interpreted in terms of fluid-filled stress aligned microcracks in the rockmass (EDA). In other words, the polarisation direction of the faster shear-wave splitting is parallel to SHmax. However, other researches on seismic anisotropy carried out in NE Brazil have shown a remarkable consistency of the faster shear-wave polarisation direction with the direction of the Precambrian fabric. The present work is another case study that is used to investigate this issue. In order to map the Precambrian fabric we used aeromagnetic data, since the study area is mostly covered with sediments (up to 50m thick) and in-situ field mapping would be very difficult to be carried out. According to the results from the present research, the observations of the faster shear-wave polarisation directions in two seismographic stations in Cascavel region are best explained in the framework of EDA. For the remaining two stations, the observed anisotropy may have two interpretions: (i) - 90_ flips of the direction of polarisation of the faster shear-wave, since that the event-to-station ray path would be through the fracture zone and hence would travel under a higher pore pressure and (ii) - the observed seismic anisotropy would agree with the direction on the ductile Precambrian fabric

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The seismic reflection is used on a large scale in oil exploration. In case of marine acquisition the presence of high impedance contrast at the interfaces water/air generates multiple reflections events. Such multiple events can mask primary events; thus from the interpretational viewpoint it is necessary to mitigate the multiples. In this manuscript we compare two methods of multiple attenuation: the predictive multichannel deconvolution (DPM) and the F-K filtering (FKF). DPM is based in the periodicity of the multiples while FKF is based in multiples and primaries splitting in F-K domain. DPM and FKF were applied in common-offset and CDP gathers, respectively. DPM is quite sensible to the correct identification of the period and size of the filter while FKF is quite sensible to an adequate choice of the velocity in order to split multiples and primaries events in the F-K domain. DPM is a method that is designed to act over a specific event. So, when the parameters are well selected, DPM is very efficient in removing the specified multiple. Then DPM can be optimized by applying it several times, each time with a different parameterization. A deficiency of DPM occurs when a multiple is superposed to a primary event: in this situation, DPM can attenuate also the primary event. On the other hand, FKF presents almost the same performance to all multiples that are localized in the same sector of the F-K domain. The two methods can be combined in order to take advantage of their associated potentials. In this situation, DPM is firstly applied, with a focus in the sea bed multiples. Then FKF is applied in order to attenuate the remaining multiples