31 resultados para Invariância a escala
em Universidade Federal do Rio Grande do Norte(UFRN)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
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Recent studies have shown evidence of log-periodic behavior in non-hierarchical systems. An interesting fact is the emergence of such properties on rupture and breakdown of complex materials and financial failures. These may be examples of systems with self-organized criticality (SOC). In this work we study the detection of discrete scale invariance or log-periodicity. Theoretically showing the effectiveness of methods based on the Fourier Transform of the log-periodicity detection not only with prior knowledge of the critical point before this point as well. Specifically, we studied the Brazilian financial market with the objective of detecting discrete scale invariance in Bovespa (Bolsa de Valores de S˜ao Paulo) index. Some historical series were selected periods in 1999, 2001 and 2008. We report evidence for the detection of possible log-periodicity before breakage, shown its applicability to the study of systems with discrete scale invariance likely in the case of financial crashes, it shows an additional evidence of the possibility of forecasting breakage
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VARELA, M. L. et al. Influência da adição de resíduo de caulim nas propriedades tecnológicas de uma massa padrão de porcelanato produzido em escala industrial. Cerâmica, v.55, n.334 p.209-215. 2009.ISSN 0366-6913.Disponível em:
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MARIANO, J. L. ; FIGUEIREDO, ERIK A. . Efeitos da composição domiciliar e da escala equivalente sobre as medidas de desigualdade de renda e pobreza no Brasil. In: XXXVI Encontro Nacional de Economia,Salvador 2008.
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The present study provides a methodology that gives a predictive character the computer simulations based on detailed models of the geometry of a porous medium. We using the software FLUENT to investigate the flow of a viscous Newtonian fluid through a random fractal medium which simplifies a two-dimensional disordered porous medium representing a petroleum reservoir. This fractal model is formed by obstacles of various sizes, whose size distribution function follows a power law where exponent is defined as the fractal dimension of fractionation Dff of the model characterizing the process of fragmentation these obstacles. They are randomly disposed in a rectangular channel. The modeling process incorporates modern concepts, scaling laws, to analyze the influence of heterogeneity found in the fields of the porosity and of the permeability in such a way as to characterize the medium in terms of their fractal properties. This procedure allows numerically analyze the measurements of permeability k and the drag coefficient Cd proposed relationships, like power law, for these properties on various modeling schemes. The purpose of this research is to study the variability provided by these heterogeneities where the velocity field and other details of viscous fluid dynamics are obtained by solving numerically the continuity and Navier-Stokes equations at pore level and observe how the fractal dimension of fractionation of the model can affect their hydrodynamic properties. This study were considered two classes of models, models with constant porosity, MPC, and models with varying porosity, MPV. The results have allowed us to find numerical relationship between the permeability, drag coefficient and the fractal dimension of fractionation of the medium. Based on these numerical results we have proposed scaling relations and algebraic expressions involving the relevant parameters of the phenomenon. In this study analytical equations were determined for Dff depending on the geometrical parameters of the models. We also found a relation between the permeability and the drag coefficient which is inversely proportional to one another. As for the difference in behavior it is most striking in the classes of models MPV. That is, the fact that the porosity vary in these models is an additional factor that plays a significant role in flow analysis. Finally, the results proved satisfactory and consistent, which demonstrates the effectiveness of the referred methodology for all applications analyzed in this study.
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A self-flotator vibrational prototype electromechanical drive for treatment of oil and water emulsion or like emulsion is presented and evaluated. Oil production and refining to obtain derivatives is carried out under arrangements technically referred to as on-shore and off-shore, ie, on the continent and in the sea. In Brazil 80 % of the petroleum production is taken at sea and area of deployment and it cost scale are worrisome. It is associated, oily water production on a large scale, carrier 95% of the potential pollutant of activity whose final destination is the environment medium, terrestrial or maritime. Although diversified set of techniques and water treatment systems are in use or research, we propose an innovative system that operates in a sustainable way without chemical additives, for the good of the ecosystem. Labyrinth adsor-bent is used in metal spirals, and laboratory scale flow. Equipment and process patents are claimed. Treatments were performed at different flow rates and bands often monitored with control systems, some built, other bought for this purpose. Measurements of the levels of oil and grease (OGC) of efluents treaty remained within the range of legal framework under test conditions. Adsorbents were weighed before and after treatment for obtaining oil impregna-tion, the performance goal of vibratory action and treatment as a whole. Treatment technolo-gies in course are referenced, to compare performance, qualitatively and quantitatively. The vibration energy consumption is faced with and without conventional flotation and self-flotation. There are good prospects for the proposed, especially in reducing the residence time, by capillary action system. The impregnation dimensionless parameter was created and confronted with consecrated dimensionless parameters, on the vibrational version, such as Weber number and Froude number in quadratic form, referred to as vibrational criticality. Re-sults suggest limits to the vibration intensity
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This study aimed at assessing the interobserver reliability of the Brazilian-Portuguese version of the Berg Balance Scale (BBS). The assessment was made by physiotherapists with extensive or little clinical experience in non-institutionalized elderly individuals. Participants comprised 12 elderly subjects (10 women and 2 men) with mean ages of 75.8 ± 8.4 years (range = 63-87) and 18 physiotherapists with varying clinical experience. Inter-examiner reliability obtained for each scale item yielded weighted kappa value > 0.75 in 11 of the 14 items (varying from 0.37 to 1.0). The intra-class correlation coefficient (ICC) for the total sum of BBS scores between the two groups of physiotherapists was 0.996 (95% confidence interval, 0.987 0.999) with a Cronbach alpha coefficient of 0.996. We found no difference between the rater groups when we compared the sum score means obtained with the student s T-test (p = 0.86). Although some items had low reliability values, in general our results suggest that the Brazilian Version of the BBS showed good levels of interrater reliability and agreement when used by physiotherapists with different clinical practice levels and without previous training on non-institutionalized elderly patients. We concluded that the BBS can be useful as an important evaluation instrument on a protocol for Rehabilitation clinics. It may be used by various health professionals, as: Physicians, Physical therapists, Physical educators, Occupational therapists, Nurses and Phonoaudiologists, so confirming the interdisciplinary character of this study
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This study compared the evolution of posture, tone and neonatal reflexes in preterm infants without clinical or neurological complications before and after the age of term using the scale of Saint-Anne Dargassies. To reach the age of the term, was applied Scales Amiel-Barrier-Shnider changed and the Prechtl, traditionally used in the evaluation of term newborns, looking for possible changes to the term, while also evaluating the sensitivity of these scales. We studied 20 non-complicated preterm infants, both sexes aged 32-36 weeks, born in Januário Cicco Maternity School, from August 2006 to August 2007. Was applied to the scale of Saint-Anne Dargassies every two weeks until reach the term, and the range of Amiel-Barrier-Shnider changed and the Prechtl, after reaching 39 and 41 weeks. The evaluation result of articular angles was subjected to the test of Friedman ANOVA, significant differences between the three measurements of the scale of Saint-Anne Dargassies only for angles heel-to-ear to term. Neonatal reflexes changed in the period of prematurity were the cardinal points reflexes, Moro reflexes, cross extensions reflex and the automatic walking reflexes. The posture was the parameter which remained unchanged in the three scales. Considering a significance level of 5% by applying Cochran Q Test, it was found that the scale of Saint-Anne Dargassies is more sensitive to detect suspects. With this methodology and the results it was possible to prepare a manuscript: The neurological examination of non-complicated preterm newborns using the Sanit-Anne Dargssies Scale from birth to term: normal or altered? In which we describe that despite the good clinical condition, the RNP show changes in tone and neonatal reflexes. These data are important because though non-complicated RNP need further attention its maturation process, enabling us to detect and intervene early. With these results we can build a scale simplified neurological assessment made with items found most altered during the application of three scales. The development of this project has a multidisciplinary approach, because it involved Paediatric Neurologist, Physiotherapist and Neonatologist, as recommended by PPGCSA
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Currently, we attend a reverence of concepts ahead as health, life, youth and body. In we widen amount the ideals concerned to the healthful life, to the quality of life, the longevity and joviality and the extremities of the body represented by the illness, for the virus infection, the physical deficiency and the aging. Of the historical shades of the plague, of the hunger and the war that gagged the defenseless individual and its body, in the current days we increase the search for a full and powerful life, independent of a religious imaginary to predict the epidemic curse, the threat represented for the sick people and the incarnate divine anger in the death; or of medical science presented in the spaces of the technology and the physiology, being left fragile the social and psychological dimensions of the human confined to the patient issue and, finally, the commanded urban health politics in quantitative goals of hygienic cleaning, of the medical techniques and the education citizen. For beyond these instances, emerges in our days a plural, close and biographical agreement well of the body and welfare. On the other hand, an understanding of the healthful life and well-being that more certifies the presence of something the one that clear landmarks amongst normality and the irregularity, the esteem and the destructive vice: it has a projection of healthful life measures without conceptual models of body and health under the doctor-scientific standard occidental. This thematic one will confide in way to the enclosure for spaces to the muscles and fitness exercises and the bars from the city of Natal, in the state of Rio Grande do Norte, Brazil, while comprehensive interchange concerning as the individual comes dealing with the notion the body and health and, mainly, if perceiving inside of its body and its health. Amongst these two spaces of typical leisure of the modern urban phenomenon, the hedonism bodily with its muscles and salience and one another form of hedonism in the fruition of allowed drugs will be across itself in a dialogue about which social s relationships are really in game in an imaginary construction amongst an doctor-aesthetic ideal of health and the social and subjective experience in the option for a healthful life
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The problem facing the incidence of pressure ulcers (UP) in the hospital environment especially in the intensive care unit (ICU), although it is an old and frequent event in our professional practice, it is not notified in the researches as much as it should be. We observed a tendency to invest in therapeutical and in studies about the production of sophisticated new bandages. Few, however, are the investments in research on preventive measures in order to prevent or at least slow down the development of lesions. In this sense, the study aimed to analyze the correlation between nursing care and the risk of developing UP measured by the Braden scale in ICU patients. This is a descriptive study of longitudinal quantitative approach. The project obtained a favourable opinion from the Ethics Committee of HUOL (no 486/10). Data collection was carried out in the Hospital of Unimed in Natal during six months in 2011. The sample was of 32 patients hospitalized in ICU for over four days. The results were processed in SPSS 15.0 for descriptive statistics and inferential statistics. We identified that, only 9.4% of our sample developed UP, being predominantly male, elderly people aged above 60 years, Caucasian, with diagnostic hypothesis at the time of hospitalization of sepsis, were clinical patients, who presented hemodynamic instability, using orotracheal tube (TOT), enteral probe (SNE), vesical probe delay (SVD) and had values of albumin and hemoglobin levels below normal. In addition, these patients had a longer hospital stay, longer usage of TOT, SNE, SVD, increased use of sedation and drain than those who did not develop UP and were all at risk for developing these injuries second Braden scores. 66.7% of the lesions developed were located in the sacral region, limiting the degree I and all patients that developed were considered serious, 100.0% of them have evolved since the death. Small were the differences between the averages of Braden scores between patients with and without UP, 11,9+2,4 against 12,4+2,6 with p = 0.627. The clinical aspects of the patients in the study were instrumental in the development of UP, once, these findings were statistically significant through the Mann-Whitney test, and appropriateness of nursing conduct was decisive for the prevention of pressure ulcers in critical patients, since many were those classified as at risk (28) and few who have developed lesions (03)
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A modeling of criterias and alternatives is through and applied a questionnaire based on method AHP to proprietors of gas stations. The considered alternatives had been the maintenance of the current state with electric energy of the deliverer and the generation in small scale based on the natural gas. The used criteria had been Cost of the Investment, Final Cost of the Energy, Operational cost, Ambient Benefits, Risk and Variation of Costs. The study it was carried through in the city of Natal, RN in ranks that make use of the natural as for resale, where the generation alternative on the basis of the available gas is present. The main results evidence in a dimension the viability of use of method AHP with questionnaire by means of validation of the judgments with analysis of variance beyond proper the normal mechanisms of analysis of consistency to the method. The main results of the analysis help to show that in this in case that the profile of models of criteria and judgments of the actors is similar, with the final evidence of that it has a dominance of the maintenance of the energy of the deliverer. The main criterion to influence this decision was the risk
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This Master s Thesis proposes the application of Data Envelopment Analysis DEA to evaluate economies of scale and economies of scope in the performance of service teams involved with installation of data communication circuits, based on the study of a major telecommunication company in Brazil. Data was collected from the company s Operational Performance Division. Initial analysis of a data set, including nineteen installation teams, was performed considering input oriented methods. Subsequently, the need for restrictions on weights is analyzed using the Assurance Region method, checking for the existence of zero-valued weights. The resulting returns to scale are then verified. Further analyses using the Assurance Region Constant (AR-I-C) and Variable (AR-I-V) models verify the existence of variable, rather than constant, returns to scale. Therefore, all of the final comparisons use scores obtained through the AR-I-V model. In sequence, we verify if the system has economies of scope by analyzing the behavior of the scores in terms of individual or multiple outputs. Finally, conventional results, used by the company in study to evaluate team performance, are compared to those generated using the DEA methodology. The results presented here show that DEA is a useful methodology for assessing team performance and that it may contribute to improvements on the quality of the goal setting procedure.
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This Master s Thesis proposes the application of Data Envelopment Analysis DEA to evaluate the performance of sales teams, based on a study of their coverage areas. Data was collected from the company contracted to distribute the products in the state of Ceará. Analyses of thirteen sales coverage areas were performed considering first the output-oriented constant return to scale method (CCR-O), then this method with assurance region (AR-O-C) and finally the method of variable returns to scale with assurance region (AR-O-V). The method used in the first approach is shown to be inappropriate for this study, since it inconveniently generates zero-valued weights, allowing that an area under evaluation obtain the maximal score by not producing. Using weight restrictions, through the assurance region methods AR-O-C and AR-O-V, decreasing returns to scale are identified, meaning that the improvement in performance is not proportional to the size of the areas being analyzed. Observing data generated by the analysis, a study is carried out, aiming to design improvement goals for the inefficient areas. Complementing this study, GDP data for each area was compared with scores obtained using AR-O-V analysis. The results presented in this work show that DEA is a useful methodology for assessing sales team performance and that it may contribute to improvements on the quality of the management process.
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Biosurfactants are amphiphilic molecules synthesized by microorganisms such as bacteria, yeast or filamented fungi cultivated in various carbon sources among sucrose and hydrocarbons. These molecules are composed by a hydrophilic and hydrophobic part. They operate mostly at interfaces of fluids of different polarities. Because of this characteristic, they are potentially employed in numerous industries, such as the textile, medical, cosmetics, food and mainly in the petrochemical ones. Therefore industry has interest in developing new biosurfactant production processes in high scale, in order to become them economically competitive when compared to synthetic biosurfactants. This work aims to evaluate the biosurfactant production applying a non-conventional substrate sugar cane molasses proceeding from the sugar industry thus reducing the production costs. The strain identified as AP029/GLIIA, isolated from oil wells in Rio Grande do Norte state and used in these experiments belongs to the culture collection of Antibiotics Department of UFPE. The fermentation were carried out using different conditions according to a factorial planning 24 with duplicate at center point, in which the studied factors were molasse concentration, nitrate concentration, agitation and aeration ratio. The experiments were performed in a shaker at 38ºC of temperature. Samples were withdrawn in regular periods of time of up to 72 hours of fermentation in order to analyze substrate consumption, cellular concentration, superficial tension, critical micelle dilution (CMD-1 e CMD-2) as well as extracelullar protein production. The results showed a production of 3,480 g/L of biomass, a reduction of 41% on superficial tension, 67% of substrate consumption and 0,2805 g/L of extracellular protein
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The aim of this work is to use a new technology in the treatment of produced wastewaters from oil industry. An unit for treat produced waters called UTMDIF, was designed, installed and operated in an industrial plant for treatment of effluents from oil industry. This unit operates by means of the method of separation of phase inversion and can become a promising alternative to solve the problem of oil/water separation. This method constitutes the basis of the working of a new design of mixersettler of vertical configuration which occupies small surface area. The last characteristic becomes specially important when there is limitation on the lay-out of the plant, for example, over maritime platforms to explore oil. This equipment in a semi-industrial scale treats produced wastewaters contaminated with oil at low concentrations (ranging from 30 to 150 mg/L) and throughputs of 320 m3/d (47,4 m3 m-2 h-1). Good results were obtained in oil/water separation which leads to the necessary specification to discharge those wastewaters. Besides, the non dependence of the efficiency of separation in spite of the salinity of the medium becomes the equipment an attractive new technology to treat wastewaters containing oil at low concentrations