Evolução da excentricidade dos sistemas binários com componente evoluída

On this study we have revisited the predicted tidal circularization theory in close binary systems with a evolved component. Close binaries suffer tidal interactions that tend to synchronize periods and circularize the orbits (Zahn 1977, 1989, 1992). According to Zahn s theory we compute the integral that give us the variation of the eccentricity in a binary under the influence of tidal force and we compare the integral results with new observations for 260 binary systems with orbital solutions. Our results confirm the success of the Zahn s theory with a new data and new stellar evolutionary models, on the other hand, our results points to the need for a better description of the role of convection on this theory

Entre o mar e estrela, um lugar para se bem viver : a problemática da expansão urbana da Cidade de Baía Formosa/RN

The urban expansion problem of Baía Formosa, a southern edge city of de Rio Grande do Norte eastern coast, which has been presented in other coast Brazilian towns, specially on those with tourist activities increase. Therefore, this situation brings huge concerns to their inhabitants, to their technical /scientific community and to the governments, because of the conflicts of interest and of the growth of urban problems that this has been created. At Baía Formosa, the situation is aggravated because the city is confined, once around it, there are large private proprieties, environmental preservation area and the sea, at the eastern edge. The objectives of this study are the analyses of this city expansion process in order to obtain adequate alternatives and defining methodology to apply in other urban nucleus that are subjected to similar situations. Of course, presents social relations, environmental conditions and promoting local population insertion should be considered in order that enjoin this process and contributing to a better social balance. This case study has used bibliography research, field data, maps and soil occupation recorders and photographs of the area, besides the primary data gathering by surveys carried out with many social actors. The present analysis shows that the urban expansion observed today is featured by a recent unsustainable model, which attacks the environment and brings either farm conflicts. On the other hand, the ecological tourism can represent an alternative in order to achieve an adequate expansion form, without forgetting the several structural parameters necessary to support the sustainable activities

No céu da boca das gentes, tem estrela e maravilhas: atualização e permanência das narrativas populares nos contos de enganar a morte

This current study consists in an analysis of the work Contos de enganar a morte (2004), of the novelist, illustrator and researcher of popular culture Ricardo Azevedo, aiming to highlight aspects and elements present in this work which show the update and the permanence of traditional popular narratives, widespread by orality, especially those collected by the Luís da Câmara Cascudo in Literatura oral no Brasil (1984), linked to the category of the Cycle of the Death and Tales of the Deceived Demon. It is argued that the symbolic, playful, humor and aspects of orality, evident in these narratives are cultural possessions own of a popular tradition that diffuses, is updated and maintained by the memory of handmade anonymous narrators (BENJAMIN, 1994), poets and brazilian singers of cordel, holders of the traditional knowledge not established, but polyphonic, dialogical and democratic in essence (BAKHTIN, 1996). Still, alongside the people who know and counts the stories of Trancoso and Fairies, the tale, as a written literary genre, has allowed to maintain outstanding the same subjects successively renewed, enabling the resistance of popular narrative tradition and understanding and appreciation of popular orality (ZUMTHOR, 1993; 2000) and of the updates performed in the contemporarity (CANDIDO, 1976), without losing sight of the singularity and autonomy of the literary work

Um estudo sobre a interação estrela-planeta a partir da relação massa-período planetário com a atividade estelar

n this work, we analyze the behavior of the chromospheric and coronal activities as a function of the mass and the orbital period of extrasolar planets which were detected by transit technique. So we look for possible effects of the planet on the star s chromosphere and corona. For this study we selected a sample of 48 stars with chromospheric activity indicator and 23 with coronal activity indicator. Our work is based on the work from Pont et al. (2011) in order to study stars with planets which were obtained by transit technique. Furthermore, we studied the relationship between planetary mass and orbital period with the chromospheric and coronal activity in order to better understand which influences the planets cause in the outer layers of stellar atmosphere. In our analysis we can observe that the mass of the planets exerts no influence in the stellar activity. However, we observed that the stellar coronal and chromospheric activities decrease with the increase of the orbital period of the planet

Um estudo sobre a interação estrela-planeta a partirda relação massa-período planetário com a atividade estelar

In this work, we analyze the behavior of the chromospheric and coronal activities as a function of the mass and the orbital period of extrasolar planets which were detected by transit technique. So we look for possible effects of the planet on the star s chromosphere and corona. For this study we selected a sample of 48 stars with chromospheric activity indicator and 23 with coronal activity indicator. Our work is based on the work from Pont et al. (2011) in order to study stars with planets which were obtained by transit technique. Furthermore, we studied the relationship between planetary mass and orbital period with the chromospheric and coronal activity in order to better understand which influences the planets cause in the outer layers of stellar atmosphere. In our analysis we can observe that the mass of the planets exerts no influence in the stellar activity. However, we observed that the stellar coronal and chromospheric activities decrease with the increase of the orbital period of the planet

Interação estrela planeta: sobre o magnetismo de planetas gigantes gasosos

In this thesis we analyze the effects that the presence of a near gas giant planet can cause in its host star. It has been argued that the star planet interaction can cause changes in the coronal and chromospheric stellar activity. With this in mind, we analyze a sample of 53 extrasolar planets orbiting F, G and K main sequence stars, among them three super-Earths. In this analysis, we look for evidence of changes in the chromospheric activity due to the proximity of the giant planet. We show that, so far, there is not enough evidence to support such a hypothesis. Making use of the same sample and also taking in account available data for the Solar System, we revisit the so-called magnetic Bode s law. This law proposes the existence of a direct relationship between magnetism and rotation. By using estimations for the stellar and planetary magnetic momentM and the angular momentumL, we construct a Blackett s diagram (logL 􀀀logM). In this diagram is evident that the magnetic Bode s law is valid for both the Solar System and the new planetary systems

Análise espectroscópica da estrela HD 150050: uma nova estrela gigante rica em lítio

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Rotação e processos de acreção e coalescência em sistemas planetários e sistemas binários

The discovery of giant stars in the spectral regions G and K, showing moderate to rapid rotation and single behavior, namely with constant radial velocity, represents one important topic of study in Stellar Astrophysics. Indeed, such anomalous rotation clearly violates the theoretical predictions on the evolution of stellar rotation, since in evolved evolutionary stages is expected that the single stars essentially have low rotation due to the evolutionary expansion. This property is well-established from the observational point of view, with different studies showing that for single giant stars of spectral types G and K values of the rotation are typically smaller than 5kms−1 . This Thesis seeks an effective contribution to solving the paradigm described above, aiming to search for single stars of spectral types G and K with anomalous rotation, tipically rotation of moderate to rapid, in other luminosity classes. In this context, we analyzed a large stellar sample consisting of 2010 apparently single stars of luminosity classes IV, III, II and Ib with spectral types G and K, with rotational velocity v sin i and radial velocity measurements obtained from observations made by CORAVEL spectrometers. As a first result of impact we discovered the presence of anomalous rotators also among subgiants, bright giants and supergiants stars, namelly stars of luminosity classes IV, II and Ib, in contrast to previous studies, that reported anomalous rotators only in the luminosity class III classic giants. Such a finding of great significance because it allows us to analyze the presence of anomalous rotation at different intervals of mass, since the luminosity classes considered here cover a mass range between 0.80 and 20MJ, approximately. In the present survey we discovered 1 subgiant, 9 giants, 2 bright giants and 5 Ib supergiants, in spectral regions G and K, with values of v sin i ≥ 10kms−1 and single behavior. This amount of 17 stars corresponds to a frequency of 0.8% of G and K single evolved stars with anomalous rotation in the mentioned classes of luminosities, listed at the Bright Star Catalog, which is complete to visual magnitude 6.3. Given these new findings, based on a stellar sample complete in visual magnitude, as that of the Bright Star Catalog, we conducted a comparative statistical analysis using the Kolmogorov- Smirnov test, from where we conclude that the distributions of rotational velocity, v sin i, for single evolved stars with anomalous rotation in luminosity classes III and II, are similar to the distributions of v sin i for spectroscopic binary systems with evolved components with the same spectral type and luminosity class. This vii result indicates that the process of coalescence between stars of a binary system might be a possible mechanism to explain the observed abnormal rotation in the referred abnormal rotators, at least among the giants and bright giants, where the rotation in excess would be associated with the transfer of angular momentum for the star resulting from the merger. Another important result of this Thesis concerns the behavior of the infrared emission in most of the stars with anomalous rotation here studied, where 14 stars of the sample tend to have an excess in IR compared with single stars with low rotation, within of their luminosity class. This property represents an additional link in the search for the physical mechanisms responsible for the abnormal observed rotation, since recent theoretical studies show that the accretion of objects of sub-stellar mass, such as brown dwarfs and giant planets, by the hosting star, can significantly raise its rotation, producing also a circumstellar dust disk. This last result seems to point in that direction, since it is not expected that dust disks occurring during the stage of star formation can survive until the stages of subgiants, giants and supergiants Ib. In summary, in this Thesis, besides the discovery of single G and K evolved stars of luminosity classes IV, II and Ib with anomalously high rotation compared to what is predicted by stellar evolution theory, we also present the frequency of these abnormal rotators in a stellar sample complete to visual magnitude 6.3. We also present solid evidence that coalescence processes in stellar binary systems and processes of accretion of brown dwarfs star or giant planets, by the hosting stars, can act as mechanisms responsible for the puzzling phenomenon of anomalous rotation in single evolved stars.

Entre o mar e estrela, um lugar para se bem viver : a problemática da expansão urbana da Cidade de Baía Formosa/RN

The urban expansion problem of Baía Formosa, a southern edge city of de Rio Grande do Norte eastern coast, which has been presented in other coast Brazilian towns, specially on those with tourist activities increase. Therefore, this situation brings huge concerns to their inhabitants, to their technical /scientific community and to the governments, because of the conflicts of interest and of the growth of urban problems that this has been created. At Baía Formosa, the situation is aggravated because the city is confined, once around it, there are large private proprieties, environmental preservation area and the sea, at the eastern edge. The objectives of this study are the analyses of this city expansion process in order to obtain adequate alternatives and defining methodology to apply in other urban nucleus that are subjected to similar situations. Of course, presents social relations, environmental conditions and promoting local population insertion should be considered in order that enjoin this process and contributing to a better social balance. This case study has used bibliography research, field data, maps and soil occupation recorders and photographs of the area, besides the primary data gathering by surveys carried out with many social actors. The present analysis shows that the urban expansion observed today is featured by a recent unsustainable model, which attacks the environment and brings either farm conflicts. On the other hand, the ecological tourism can represent an alternative in order to achieve an adequate expansion form, without forgetting the several structural parameters necessary to support the sustainable activities

Estudo morfológico da blenda polimérica poli(metacrilato de metila)/poli(tereftalato de etileno) reciclado (PMMA/PET)

Among the options for plastics modification more convenient, both from a technical-scientific and economic, is the development of polymer blends by processing in the molten state. This work was divide into two stages, with the aim to study the phase morphology of binary blend PMMA / PET blend and this compatibilized by the addition of the poly(methyl methacrylate-co-glycidyl methacrylate-co-ethyl acrylate) copolymer (MMA-GMA-EA). In the first stage is analyzed the morphology of the blend at a preliminary stage where we used the bottle-grade PET in a Haake torque rheometer and the effect of compatibilizer in this blend was evaluated. In the second stage the blend was processed using the recycled PET in a single screw extruder and subsequently injection molding in the shape of specimens for mechanical tests. In both stages we used a transmission electron microscopy (TEM) to observe the morphologies of the samples and an image analyzer to characterize them. In the second stage, as well as analysis by TEM, tensile test, scanning electron microscopy (SEM) and atomic force microscopy (AFM) was performed to correlate the morphology with the mechanical properties. The samples used in morphological analyzes were sliced by cryo-ultramicrotomy technique for the analysis by TEM and the analysis by SEM and AFM, we used the flat face of the block after cut cryogenic. It was found that the size of the dispersed phase decreased with the addition of MMA-GMA-EA in blends prepared in a Haake. In the tensile test, the values of maximum tensile strength and modulus of elasticity is maintained in a range between the value of pure PMMA the pure PET, while the elongation at break was influenced by the composition by weight of the PMMA mixture. The coupling agent corroborated the results presented in the blend PMMA / PETrec / MMA-GMA-EA (80/15/5 %w/w), obtained by TEM, AFM and SEM. It was concluded that the techniques used had a good morphologic correlation, and can be confirmed for final analysis of the morphological characteristics of the blends PMMA / PET

Efeito da adição do poli(etileno acrilato de metila) (ema) e da fibra de linter de algodão nas propriedades do poli(tereftalato de etileno) reciclado (petrec)

The development of new materials to fill the demand of technological advances is a challenge for many researchers around the world. Strategies such as making blends and composites are promising alternatives to produce materials with different properties from those found in conventional polymers. The objective of this study is to evaluate the effect of adding the copolymer poly(ethylene methyl acrylate) (EMA) and cotton linter fibers (LB) on the properties of recycled poly(ethylene terephthalate) (PETrec) by the development of PETrec/EMA blend and PETrec/EMA/LB blend composite. In order to improve the properties of these materials were added as compatibilizers: Ethylene - methyl acrylate - glycidyl methacrylate terpolymer (EMA-GMA) and maleic anhydride grafted polyethylene (PE-g-MA). The samples were produced using a single screw extruder and then injection molded. The obtained materials were characterized by thermogravimetry (TG), melt flow index (MFI) mensurements, torque rheometry, pycnometry to determinate the density, tensile testing and scanning electron microscopy (SEM). The rheological results showed that the addition of the EMA copolymer increased the viscosity of the blend and LB reduces the viscosity of the blend composite. SEM analysis of the binary blend showed poor interfacial adhesion between the PETrec matrix and the EMA dispersed phase, as well as the blend composite of PETrec/EMA/LB also observed low adhesion with the LB fiber. The tensile tests showed that the increase of EMA percentage decreased the tensile strength and the Young s modulus, also lower EMA percentage samples had increased the elongation at break. The blend composite showed an increase in the tensile strength and in the Young`s modulus, and a decrease in the elongation at break. The blend formulations with lower EMA percentages showed better mechanical properties that agree with the particle size analysis which showed that these formulations presented a smaller diameter of the dispersed phase. The blend composite mechanical tests showed that this material is stronger and stiffer than the blend PETrec/EMA, whose properties have been reduced due to the presence of EMA rubbery phase. The use of EMA-GMA was effective in reducing the particle size of the EMA dispersed phase in the PETrec/EMA blend and PE-g-MA showed evidences of reaction with LB and physical mixture with the EMA

Influência de fatores biopsicossociais sobre a mortalidade de idosos no município de Santa Cruz/RN: um estudo prospectivo

The aging process if characterizes for a complex events network, from multidimensional nature, that encloses biological, social, psychic and functional aspects. The alteration of one or more aspects can speed up the aging process, anticipating limitations and until the death in the aged. For an adjusted confrontation of this question is necessary an interdisciplinary vision, in which the some areas of the knowledge can interact and with this to intervenes of the best possible form. Then, information derived from studies of aspects related to incidence, morbidity-mortality and transition patterns, involved in the health-illness process can more accurately identify risk groups thereby establishing links between social factors, illness, incapacity and death. Thus, this study aimed to identify, by a multidimensional vision, the risk factors of mortality in a coorth of elderly in a city in the interior of the state of Rio Grande do Norte (RN), Brazil. A prospective study carried out in Santa Cruz RN, where 310 elderly were randomly selected to form a baseline. The follow-up was 53 months. The predictive variables were divided into sociodemographic, physical health, neuropsychiatric and functional capacity. The statistical analysis carried out by bivariate analysis, survival analysis, followed by binary logistic regression and Cox regression, in the multivariate analysis, considering significant levels p < 0.05 and confidence interval (CI) of 95%. A total of 60 (19.3%) elderly died during the follow-up, where cardiovascular disease was the main cause. The survival was approximately 24.8 months. The study of general survival showed, at 12, 24, 36, and 48 months of observation, a survival rate of 97%, 54%, 31%, and 5% respectively, with a statistical difference in survival only observed for the variables of cognitive function and Basic Activities of Daily Living. In the logistic regression analysis, the risk factors identified were cognitive deficits (OR = 8.74), poor perception of health (OR = 3.89) and dependence for Basic Activities of Daily Living (OR = 3.96). In the Cox analysis, as well as dependence for Basic Activities of Daily Living (HR = 3.17), cognitive deficit (HR = 4.30) and stroke (CVA) (HR = 3.49) continued as independent risk factors for death. The risk factors found in the study can be interpreted as the primary predictors for death among elderly members of the community. Therefore, improvements in health conditions, with actions towards sustaining an autonomous life with special attention for elderly with cognitive impairment, could mean additional healthy quality of life, resulting in the reduction of premature mortality in this population

Apitidão funcional e comportamentos relacionados à saúde em mulheres idosas do município de Jequié-BA

The identification of the factors that interfere in the decline of functional conditions is useful in the planning of actions addressing the improvement in the conditions of the lives of elderly people. The purpose of this investigation was to analyze the relationship between social demographics and health aspects of the functional condition in elderly women of low income of the Brazilian northeast. This crosssectional study involved a representative sample of 222 women with an average age of 70 years (± 7.1), belonging to coexisting groups and that were resident in the urban area of the municipal district of Jequié /Bahia. In order to achieve this objective, a battery of physical tests of functional aptitude was carried out previously tested in pilot study, anthropometric measurements collected with a comparison of the measures referred to the reported weight and height as well as the application of an interview with questions containing subjects related to social demographic variables, clinical conditions and health, physical conditions and behaviors. Descriptive statistics Proceedings (frequency, average, standard deviation and percent distribution) were used for statistic analysis, and the calculation of the respective odds ratio by binary logistics regression, for the analysis of factors hierarchically grouped; p<0.05. The prevalence of 56% (n=122) of women considered with moderated or serious type of functional limitations was found, In which from multi-varied hierarchical analysis, significant association was verified with the age group over 80 years (p=0.02), conditions of widowhood (p=0.04), presence of arterial hypertension (p=0.001), and physical inactivity during leisure time (p=0.03). On the other hand for functional incapacities the prevalence was of 46.8% (n=104) being associated to the increase of the age (p=0.01), hospitalization (p=0.02), absence of physical activities along their lives (p=0.001) and the occurrence of alterations in the cognitive function (p=0.001). The normative table for the parameters of physical fitness generated conducive to health professionals in the diagnosis of health conditions and the prescription of physical exercises. The identified characteristics that are associated with the functional limitations / functional incapacities suggest a complex causal net in the determination of the functional condition in elderly women. However, actions addressed to the incentive of the practice of physical activities in the leisure time and the preservation of the cognitive function can contribute to a life with more quality for these people. This research was multidisciplinary approach to involve elements of psychology, nutrition and Physical Education in the elucidation of the object of study related to the functional condition of elderly women

Caracteristicas sodiodemogáficas, ocupacionais e de saúde na avaliação da qualidade de vida de professores da rede municipal de Natal/RN

Objetivo: Analisar as características sociodemográficas, ocupacionais e de saúde clínica/comportamental, e o impacto desses fatores na avaliação da qualidade de vida de professores da rede municipal de Natal/RN. Métodos: Estudo descritivo-analítico com corte transversal e amostra de 242 docentes. Foram utilizados os questionários Whoqol-breve e nórdico, além de questões referentes ao trabalho do Job Content Questionnaire (JCQ). Os dados foram submetidos à análise estatística com nível de significância p<0,05, sendo utilizada a regressão logística binária, para análise de fatores hierarquicamente agrupados. Resultados: O domínio físico apresentou maior comprometimento entre os professores com trabalho de alta exigência (p=0,043), com mais de 02 diagnósticos de doenças (p < 0,001), atividade física inadequada (p= 0,001) e com sintomas osteomusculares (p=0.025); o domínio psicológico entre os docentes com trabalho de alta exigência (p=0,043), com carga horária maior que 28 horas semanais (p=0,034), com mais de 02 doenças (p=0,012) e que praticavam atividade física inadequadamente (p< 0,001); o de relações sociais com tempo de trabalho inferior/igual a 18 anos (p=0,036) e que residiam em bairro diferente do que trabalhavam (p=0,027); e, por último, o domínio meio ambiente apresentou maior comprometimento entre os docentes com carga horária superior a 28 horas semanais (p=0,025), que exerciam a atividade com tempo inferior/igual a 18 anos (p=0,013) e com sintomas osteomusculares (p= 0,002). Conclusões: Os professores apresentaram uma avaliação comprometida da qualidade de vida e do seu estado de saúde, tendo as atividades laborais desenvolvidas por esse grupo de trabalhadores um impacto importante sobre os resultados demonstrados. Tais achados podem comprometer a efetivação da proposta das escolas promotora de saúde

Relação entre ambiente familiar e capacidade funcional de idosos residentes no município de Jequié-BA

(Objective) Assess the functional capacity and determine the difference between the means of functional capacity (basic and instrumental activities of daily living) and the age groups of elderly residents in an outlying area in the hinterland of Bahia/Northeast of Brazil. (Methods) Analytical study with cross-sectional design and a sample of 150 elderly individuals enrolled in four Health Units in the municipality of Jequié, Bahia, Brazil. The instrument consisted of sociodemographic and health data, the Barthel Index and the Lawton scale. (Results) In all, 78.00% of the elderly were classified as dependent in the basic activities and 65.33% in the instrumental activities of daily living. Using the Kruskal- Wallis test, we found a statistically significant difference between the means of instrumental activities and the age groups (p= 0.011). (Conclusion) An elevated number of elderly were classified as dependent in terms of functional capacity and increased age is related to greater impairment in the execution of instrumental activities of daily living