Análise wavelet e modelo de manchas em curvas de luz estelares dos telescópios espaciais Kepler e CoRoT

Analogous to sunspots and solar photospheric faculae, which visibility is modulated by stellar rotation, stellar active regions consist of cool spots and bright faculae caused by the magnetic field of the star. Such starspots are now well established as major tracers used to estimate the stellar rotation period, but their dynamic behavior may also be used to analyze other relevant phenomena such as the presence of magnetic activity and its cycles. To calculate the stellar rotation period, identify the presence of active regions and investigate if the star exhibits or not differential rotation, we apply two methods: a wavelet analysis and a spot model. The wavelet procedure is also applied here to study pulsation in order to identify specific signatures of this particular stellar variability for different types of pulsating variable stars. The wavelet transform has been used as a powerful tool for treating several problems in astrophysics. In this work, we show that the time-frequency analysis of stellar light curves using the wavelet transform is a practical tool for identifying rotation, magnetic activity, and pulsation signatures. We present the wavelet spectral composition and multiscale variations of the time series for four classes of stars: targets dominated by magnetic activity, stars with transiting planets, those with binary transits, and pulsating stars. We applied the Morlet wavelet (6th order), which offers high time and frequency resolution. By applying the wavelet transform to the signal, we obtain the wavelet local and global power spectra. The first is interpreted as energy distribution of the signal in time-frequency space, and the second is obtained by time integration of the local map. Since the wavelet transform is a useful mathematical tool for nonstationary signals, this technique applied to Kepler and CoRoT light curves allows us to clearly identify particular signatures for different phenomena. In particular, patterns were identified for the temporal evolution of the rotation period and other periodicity due to active regions affecting these light curves. In addition, a beat-pattern vii signature in the local wavelet map of pulsating stars over the entire time span was also detected. The second method is based on starspots detection during transits of an extrasolar planet orbiting its host star. As a planet eclipses its parent star, we can detect physical phenomena on the surface of the star. If a dark spot on the disk of the star is partially or totally eclipsed, the integrated stellar luminosity will increase slightly. By analyzing the transit light curve it is possible to infer the physical properties of starspots, such as size, intensity, position and temperature. By detecting the same spot on consecutive transits, it is possible to obtain additional information such as the stellar rotation period in the planetary transit latitude, differential rotation, and magnetic activity cycles. Transit observations of CoRoT-18 and Kepler-17 were used to implement this model.

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.

Efeitos do freio magnético sobre a distribuição da rotação estelar

The pioneering work proposed by Skumanich (1972) has shown that the projected mean rotational velocity < v sini > for solar type stars follows a rotation law decreases with the time given by t −1/2 , where t is the stellar age. This relationship is consistent with the theories of the angular momentum loss through the ionized stellar wind, which in turn is coupled to the star through its magnetic field. Several authors (e.g.: Silva et al. 2013 and de Freitas et al. 2014) have analyzed the possible matches between the rotational decay and the profile of the velocity distribution. These authors came to a simple heuristic relationship, but did not build a direct path between the exponent of the rotational decay (j) and the exponent of the distribution of the rotational velocity (q). The whole theoretical scenario has been proposed using an efficient and strong statistical mechanics well known as non-extensive statistical mechanics. The present dissertation proposes effectively to close this issue by elaborating a theoretical way to modify the q-Maxwellians’ distributions into q-Maxwellians with physics links extracted from the theory of magnetic braking. In order to test our distributions we have used the GenevaCapenhagen Survey data with approximately 6000 F and G field stars limited by age. As a result, we obtained that the exponents of the decay law and distribution follow a similar relationship to that proposed by Silva et al. (2013).

Análise wavelet em curvas de luz estelares de sistemas binários da missão espacial CoRoT

Binary systems are key environments to study the fundamental properties of stars. In this work, we analyze 99 binary systems identified by the CoRoT space mission. From the study of the phase diagrams of these systems, our sample is divided into three groups: those whose systems are characterized by the variability relative to the binary eclipses; those presenting strong modulations probably due to the presence of stellar spots on the surface of star; and those whose systems have variability associated with the expansion and contraction of the surface layers. For eclipsing binary stars, phase diagrams are used to estimate the classification in regard to their morphology, based on the study of equipotential surfaces. In this context, to determine the rotation period, and to identify the presence of active regions, and to investigate if the star exhibits or not differential rotation and study stellar pulsation, we apply the wavelet procedure. The wavelet transform has been used as a powerful tool in the treatment of a large number of problems in astrophysics. Through the wavelet transform, one can perform an analysis in time-frequency light curves rich in details that contribute significantly to the study of phenomena associated with the rotation, the magnetic activity and stellar pulsations. In this work, we apply Morlet wavelet (6th order), which offers high time and frequency resolution and obtain local (energy distribution of the signal) and global (time integration of local map) wavelet power spectra. Using the wavelet analysis, we identify thirteen systems with periodicities related to the rotational modulation, besides the beating pattern signature in the local wavelet map of five pulsating stars over the entire time span.

Análise wavelet em curvas de luz estelares de sistemas binários da missão espacial CoRoT

Binary systems are key environments to study the fundamental properties of stars. In this work, we analyze 99 binary systems identified by the CoRoT space mission. From the study of the phase diagrams of these systems, our sample is divided into three groups: those whose systems are characterized by the variability relative to the binary eclipses; those presenting strong modulations probably due to the presence of stellar spots on the surface of star; and those whose systems have variability associated with the expansion and contraction of the surface layers. For eclipsing binary stars, phase diagrams are used to estimate the classification in regard to their morphology, based on the study of equipotential surfaces. In this context, to determine the rotation period, and to identify the presence of active regions, and to investigate if the star exhibits or not differential rotation and study stellar pulsation, we apply the wavelet procedure. The wavelet transform has been used as a powerful tool in the treatment of a large number of problems in astrophysics. Through the wavelet transform, one can perform an analysis in time-frequency light curves rich in details that contribute significantly to the study of phenomena associated with the rotation, the magnetic activity and stellar pulsations. In this work, we apply Morlet wavelet (6th order), which offers high time and frequency resolution and obtain local (energy distribution of the signal) and global (time integration of local map) wavelet power spectra. Using the wavelet analysis, we identify thirteen systems with periodicities related to the rotational modulation, besides the beating pattern signature in the local wavelet map of five pulsating stars over the entire time span.

A gestão de F&B num serviço de excelência Conrad Algarve - Portugal

Este relatório tem como principal objectivo a descrição e análise de todos os outlets do departamento de F&B do Conrad Algarve, Resort 5 estrelas luxo no Algarve. Estando o F&B presente ao longo de toda a estada do hóspede, torna-se num departamento em constante observação e avaliação. A falta de qualificação e formação dificulta a satisfação das elevadas expectativas do cliente que adquire uma experiencia de luxo mediante o patamar de serviço realmente alcançado por cada sector. De forma mais ou menos incisiva, esta realidade faz-se sentir na produtividade, na motivação e no atendimento geral ao cliente. Nos outlets em que os recursos a trabalhadores temporários são elevados, o decréscimo do elevado padrão de qualidade é notório aos olhos dos hóspedes. Assim, na mesma medida da falta de formação, também a rotatividade se torna um verdadeiro impedimento ao alcance de um nível estável e coerente da prestação de um serviço de luxo.

Gerenciamento de impressões e qualidade dos serviços em hotéis da Paraíba

The present study has got as its aim to show how the impressions management is being used by the hotels in Paraiba State. For that, the dramma or role play perspective has been adopted as a model for service management. From the theater metaphor, the physical environment and its components can be seen as a scenery of the service show. We conduct the reader to notice the importance of the consummer about the service quality demand and its influence on his satisfaction. A methodology with exploring and qualifying nature has been adopted by using the analyses of content technique in interviews applied to hotel managers lebeled as having 4 and 5 stars in the State, trying to check how impression management takes place, identifying impression management tools used in relation to the physical evidences and to contacting people, as well as checking managers views in the survey about the use of impression management for client satisfaction make. The information revealed that managers, maybe for being unaware about impression management theory, haven t considered neither the physical evidences yet, nor contacting people as marketing tools. About the physical evidences, we could see that hotels take actions in a pulverized way referring to environment decoration and colors, however there isn t a global usage of physical evidences to highlight the service. Contacting people by their turn, receive better importance and attention. It was possible to make sure that managers are aware about the influence of the employee over the attendance quality. This way, we may come into a conclusion that impression management at Paraiba hotels has been under used, as long as managers seem to be, most times, turned to actions related to contacting people, not having realized the planning importance and national-wide use of service scenery in a genaral way yet

Gestão do marketing de relacionamento: um estudo em empresas hoteleiras de Natal - RN

The present study it analyzes the Management of the Marketing of strategy Relationship as distinguishing for the host s companies of the city of Natal - RN. To carry through this analysis interviews with managers had been carried through, as well as the direct comment of processes, documents, actions and strategies developed for the hotels, with intention to know the level of perception and valuation of the relationship with customers, to verify resources and technologies used in the Management of the Relationship Marketing, identification, segmentation and differentiation of customers, personalization of products and services, and results of the emphasis in the relationship with customers for the host s companies. The research can be classified as exploratory - descriptive, and its universe is limited to the city of Natal, having enclosed hotels that have carried through tourist activity in 2005 and 2006. Still on the criteria of election of the sample, the study it investigated host s companies who if fit in the category superior luxury, or either, five stars, pertaining the national nets and international. How much to the treatment and analysis of the data the was made to leave of the theoretical support of the authors who work the thematic one and of the analysis of the interviews with managers, documents and processes observed for the researcher in the studied hotels. The research sample that the interviewed ones understand the importance to work the Management of the Marketing of Relationship in the host s companies me intention to get sustainable competitive advantage. One still evidenced that the searched hotels make use of strategies and instruments of Management of the Marketing of Relationship, however without an ample theoretical knowledge and yes only as base in the experience of the managers and spread processes already, generating one moment competitive advantage and not relationships of long duration

Gerenciamento de impressões e qualidade dos serviços em hotéis da Paraíba

The present study has got as its aim to show how the impressions management is being used by the hotels in Paraiba State. For that, the dramma or role play perspective has been adopted as a model for service management. From the theater metaphor, the physical environment and its components can be seen as a scenery of the service show. We conduct the reader to notice the importance of the consummer about the service quality demand and its influence on his satisfaction. A methodology with exploring and qualifying nature has been adopted by using the analyses of content technique in interviews applied to hotel managers lebeled as having 4 and 5 stars in the State, trying to check how impression management takes place, identifying impression management tools used in relation to the physical evidences and to contacting people, as well as checking managers views in the survey about the use of impression management for client satisfaction make. The information revealed that managers, maybe for being unaware about impression management theory, haven t considered neither the physical evidences yet, nor contacting people as marketing tools. About the physical evidences, we could see that hotels take actions in a pulverized way referring to environment decoration and colors, however there isn t a global usage of physical evidences to highlight the service. Contacting people by their turn, receive better importance and attention. It was possible to make sure that managers are aware about the influence of the employee over the attendance quality. This way, we may come into a conclusion that impression management at Paraiba hotels has been under used, as long as managers seem to be, most times, turned to actions related to contacting people, not having realized the planning importance and national-wide use of service scenery in a genaral way yet

Relatório de Estágio

O Relatório de Estágio apresentado espelha todo um percurso de formação profissional e pessoal desenvolvido ao longo do Mestrado em Ensino do 1.º e 2.º ciclo do Ensino Básico com a finalidade de obter a habilitação para a docência. Do percurso experienciado salienta-se a importância da Prática Educativa Supervisionada realizada no âmbito da Unidade Curricular de Integração Curricular: Prática Educativa e Relatório de Estágio. Na base da Prática Educativa Supervisionada encontram-se um conjunto de pressupostos teóricos e legais que sustentaram toda a trajetória e que são apresentados neste Relatório. Do mesmo modo, são caracterizados os contextos onde se desenvolveu a prática educativa, visto que é fulcral que a ação do professor tenha em conta as especificidades dos mesmos. Assim, é apresentada uma descrição das experiências e vivências concretizadas ao longo da prática educativa. Esta descrição é acompanhada de uma forte dimensão reflexiva que advém de uma postura crítica e indagadora em que as bases teóricas, didáticas e pedagógicas adquiridas se encontram espelhadas. As singularidades mencionadas e das quais o professor se deve capacitar, contribuem para o desenvolvimento de uma prática pedagógica com características de investigação-ação, tendo como finalidade melhorar o ambiente educativo. Importa referir que esta etapa, apoiada numa dinâmica de supervisão que contribuiu significativamente para a construção da identidade profissional, constitui apenas o início de um longo caminho do “ser professor”.

Gestão do marketing de relacionamento: um estudo em empresas hoteleiras de Natal - RN

The present study it analyzes the Management of the Marketing of strategy Relationship as distinguishing for the host s companies of the city of Natal - RN. To carry through this analysis interviews with managers had been carried through, as well as the direct comment of processes, documents, actions and strategies developed for the hotels, with intention to know the level of perception and valuation of the relationship with customers, to verify resources and technologies used in the Management of the Relationship Marketing, identification, segmentation and differentiation of customers, personalization of products and services, and results of the emphasis in the relationship with customers for the host s companies. The research can be classified as exploratory - descriptive, and its universe is limited to the city of Natal, having enclosed hotels that have carried through tourist activity in 2005 and 2006. Still on the criteria of election of the sample, the study it investigated host s companies who if fit in the category superior luxury, or either, five stars, pertaining the national nets and international. How much to the treatment and analysis of the data the was made to leave of the theoretical support of the authors who work the thematic one and of the analysis of the interviews with managers, documents and processes observed for the researcher in the studied hotels. The research sample that the interviewed ones understand the importance to work the Management of the Marketing of Relationship in the host s companies me intention to get sustainable competitive advantage. One still evidenced that the searched hotels make use of strategies and instruments of Management of the Marketing of Relationship, however without an ample theoretical knowledge and yes only as base in the experience of the managers and spread processes already, generating one moment competitive advantage and not relationships of long duration

Desporto e turismo : caraterização dos serviços desportivos e perceção da procura turística em unidades de alojamento do Algarve

O turismo desportivo é um fenómeno que tem sido estudado a partir da segunda metade do século XX, começando a existir uma oferta mais diversificada e planeada de férias em conjunto com a prática desportiva que, segundo Pereira & Carvalho (2004), favoreceu a consolidação do conceito Desporto e Turismo. Segundo Higham (2005), os destinos turísticos são lugares que atraem e satisfazem as necessidades dos visitantes, nomeadamente ao nível: dos recursos, das infra-estruturas e dos serviços necessários para facilitar as viagens para o destino, e da realização de experiências satisfatórias. Neste âmbito, os objetivos deste estudo são identificar a perceção dos gestores quanto à procura desportiva e analisar a oferta desportiva nas unidades de alojamento de 4 e 5 estrelas da região do Algarve. Para este estudo foi feita uma recolha de dados em 43 unidades de alojamento, através de um inquérito por questionário e utilizado como método de análise de dados a estatística descritiva para tratamento de questões fechadas e a análise de conteúdo nas questões abertas. Os resultados mostram que o perfil do turista do Algarve mudou, revelando que os turistas de nacionalidade inglesa pertencentes ao segmento de famílias se apresenta valores mais elevados de procura na época alta, enquanto que na época baixa o segmento de turismo sénior é o que surge em primeiro lugar da procura, sendo o tipo de turismo de sol e mar mais procurado em ambas as épocas. Conclui-se que não existem valores elevados de procura por parte de turistas cuja principal motivação seja a prática desportiva. Verificou-se ainda que tem havido uma evolução ao nível dos serviços desportivos com a existência de mais instalações e responsáveis de seção desportiva nas unidades de alojamento. Os gestores afirmam ter uma oferta adequada em matéria de desporto e que nos próximos 6 meses não irão investir. Relativamente à frequência de utilização das instalações é muito baixa. Ser pago ou gratuito também é um fator influenciador para haver uma maior frequência de utilização.

Cosmologia e astrofísica no ensino secundário

Dissertação de mest. em Física - área de especialização em Física para Ensino, Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2003

Parques de campismo. Uma proposta de projeto para a Mata Nacional do Urso

Dissertação de Mestrado, Arquitetura Paisagista, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016

As redes sociais online na hotelaria

Dissertação de Mestrado, Direção e Gestão Hoteleira, Escola Superior de Gestão, Hotelaria e Turismo, Universidade do Algarve, 2016