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

Efeitos da interação dipolar na nucleação de vórtices em nano-cilindros magnéticos

The effect of confinement on the magnetic structure of vortices of dipolar coupled ferromagnetic nanoelements is an issue of current interest, not only for academic reasons, but also for the potential impact in a number of promising applications. Most applications, such as nano-oscillators for wireless data transmission, benefit from the possibility of tailoring the vortex core magnetic pattern. We report a theoretical study of vortex nucleation in pairs of coaxial iron and Permalloy cylinders, with diameters ranging from 21nm to 150nm, and 12nm and 21nm thicknesses, separated by a non-magnetic layer. 12nm thick iron and Permalloy isolated (single) cylinders do not hold a vortex, and 21nm isolated cylinders hold a vortex. Our results indicate that one may tailor the magnetic structure of the vortices, and the relative chirality, by selecting the thickness of the non-magnetic spacer and the values of the cylinders diameters and thicknesses. Also, the dipolar interaction may induce vortex formation in pairs of 12nm thick nanocylinders and inhibit the formation of vortices in pairs of 21nm thick nanocylinders. These new phases are formed according to the value of the distance between the cylinderes. Furthermore, we show that the preparation route may control relative chirality and polarity of the vortex pair. For instance: by saturating a pair of Fe 81nm diameter, 21nm thickness cylinders, along the crystalline anisotropy direction, a pair of 36nm core diameter vortices, with same chirality and polarity is prepared. By saturating along the perpendicular direction, one prepares a 30nm diameter core vortex pair, with opposite chirality and opposite polarity. We also present a theoretical discussion of the impact of vortices on the thermal hysteresis of a pair of interface biased elliptical iron nanoelements, separated by an ultrathin nonmagnetic insulating layer. We have found that iron nanoelements exchange coupled to a noncompensated NiO substrate, display thermal hysteresis at room temperature, well below the iron Curie temperature. The thermal hysteresis consists in different sequences of magnetic states in the heating and cooling branches of a thermal loop, and originates in the thermal reduction of the interface field, and on the rearrangements of the magnetic structure at high temperatures, 5 produce by the strong dipolar coupling. The width of the thermal hysteresis varies from 500 K to 100 K for lateral dimensions of 125 nm x 65 nm and 145 nm x 65 nm. We focus on the thermal effects on two particular states: the antiparallel state, which has, at low temperatures, the interface biased nanoelement with the magnetization aligned with the interface field and the second nanoelement aligned opposite to the interface field; and in the parallel state, which has both nanoelements with the magnetization aligned with the interface field at low temperatures. We show that the dipolar interaction leads to enhanced thermal stability of the antiparallel state, and reduces the thermal stability of the parallel state. These states are the key phases in the application of pairs of ferromagnetic nanoelements, separated by a thin insulating layer, for tunneling magnetic memory cells. We have found that for a pair of 125nm x 65nm nanoelements, separated by 1.1nm, and low temperature interface field strength of 5.88kOe, the low temperature state (T = 100K) consists of a pair of nearly parallel buckle-states. This low temperature phase is kept with minor changes up to T= 249 K when the magnetization is reduced to 50% of the low temperature value due to nucleation of a vortex centered around the middle of the free surface nanoelement. By further increasing the temperature, there is another small change in the magnetization due to vortex motion. Apart from minor changes in the vortex position, the high temperature vortex state remains stable, in the cooling branch, down to low temperatures. We note that wide loop thermal hysteresis may pose limits on the design of tunneling magnetic memory cells

Demonstração didática da interação entre correntes elétricas

Apresentamos a primeira experiência crucial de Ampère mostrando a interação entre dois fios metálicos conduzindo correntes elétricas. Discutimos sua importância na história da física. Descrevemos uma reprodução moderna dos procedimentos e observações de Ampère com materiais de baixo custo.

Interação entre professora e alunos em salas de aula com proposta pedagógica de educação inclusiva

Correntes teóricas presentes na literatura científica têm demonstrado a importância das relações interpessoais para o processo de construção do conhecimento. É no contexto da interação professor e aluno que se configura a relação entre as necessidades educacionais dos alunos e as respostas pedagógicas a elas disponibilizadas, o que envolve o domínio do conhecimento pelo professor, sua capacitação técnico-científica, a competência de ensinar pesquisando, as características sócio-culturais e o perfil psicológico dos atores sociais envolvidos- professor e aluno. Buscando melhor compreender este universo, elaborou-se este estudo que teve como objetivo descrever as interações ocorridas entre uma professora, e seus alunos, em classes em que se propunha adotar uma prática pedagógica inclusiva. Os dados foram coletados em 2 salas de aula, em escola estadual de Ensino Fundamental, no município de Bauru. O processo de coleta de dados se deu através do registro da realidade de sala de aula em vídeo tape. Optou-se por este método, por permitir a recuperação posterior dos dados. A coleta se deu no transcorrer do 1º semestre do ano letivo de 2001. A análise fundamentou-se em sistema prévio de categorias, e tratou os dados quantitativa e qualitativamente. Os resultados demonstraram peculiaridades e diferenças nas interações da professora com os seus alunos, em função da presença ou ausência da deficiência. Indicaram, também, que a interação vem demonstrando avanços na prática educacional, no que diz respeito à atenção pedagógica, da professora, ao aluno com deficiência.

A influência do discurso do professor na motivação e na interação social em sala de aula

Estudos têm mostrado a importância das interações sociais desencadeadas em sala de aula como fundamentais para a aprendizagem dos alunos. Contudo, o professor deve ser capaz de motivar os estudantes para se envolverem mais ativamente com as atividades de ensino propostas. Este artigo apresenta os resultados de uma investigação sobre as interações sociais desenvolvidas no contexto de uma sala de aula do Ensino Médio, que explicou os princípios da conservação da energia mecânica com uma aula experimental de demonstração. O principal objetivo era entender como o discurso do professor pode contribuir para o bom nível de motivação do aluno durante uma aula. As entrevistas com professor e alunos e todo o processo de interação durante as atividades foram gravados, transcritos e analisados . Os resultados ressaltam a importância da abordagem discursiva dos professores para manter o processo de motivação entre os alunos.

Participação da neurotransmissão dopaminergica no efeito hiperlocomotor do neuropeptideo S

Neuropeptide S (NPS) is an endogenous 20-aminoacid peptide which binds a G protein-coupled receptor named NPSR. This peptidergic system is involved in the modulation of several biological functions, such as locomotion, anxiety, nociception, food intake and motivational behaviors. Studies have shown the participation of NPSR receptors in mediating the hyperlocomotor effects of NPS. A growing body of evidence suggests the participation of adenosinergic, dopaminergic and CRF systems on the hyperlocomotor effects of NPS. Considering that little is known about the role of dopaminergic system in mediating NPS-induced hyperlocomotion, the present study aims to investigate the locomotor actions of intracerebroventricular (icv) NPS in mice pretreated with α-metil-p-tirosine (AMPT, inhibitor of dopamine synthesis), reserpine (inhibitor of dopamine vesicle storage) or sulpiride (D2 receptor antagonist) in the open field test. A distinct group of animals received the same pretreatments described above (AMPT, reserpine or sulpiride) and the hyperlocomotor effects of methylphenidate (dopamine reuptake inhibitor) were investigated in the open field. NPS and methylphenidate increased the mouse locomotor activity. AMPT per se did not change the locomotion of the animals, but it partially reduced the hyperlocomotion of methylphenidate. The pretreatment with AMPT did not affect the psychostimulant effects of NPS. Both reserpine and sulpiride inhibited the stimulatory actions of NPS and methylphenidate. These findings show that the hyperlocomotor effects of methylphenidate, but not NPS, were affected by the pretreatment with AMPT. Furthermore, methylphenidate- and NPS-induced hyperlocomotion was impaired by reserpine and sulpiride pretreatments. Together, data suggests that NPS can increase locomotion even when the synthesis of catecholamines was impaired. Additionally, the hyperlocomotor effects of NPS and methylphenidate depend on monoamines vesicular storaged, mainly dopamine, and on the activation of D2 receptors. The psychostimulant effects of NPS via activation of dopaminergic system display clinical significance on the treatment of diseases which involves dopaminergic pathways, such as Parkinson s disease and drug addiction

Uso de produto à base de enzima e levedura na dieta de bovinos: digestibilidade dos nutrientes e desempenho em confinamento

Objetivou-se, com este trabalho, avaliar os efeitos da adição de diferentes níveis de enzima mais levedura na dieta de bovinos sobre a digestibilidade aparente dos nutrientes e o desempenho em confinamento, utilizando-se 18 animais machos, mestiços, de origem leiteira, com peso vivo (PV) médio de 190±10 kg e 12 meses de idade, e 27 animais da raça Guzerá com PV médio de 325 kg e idade média de 27 meses. Os níveis de enzima mais levedura foram zero (controle), 5 g de enzima (E) mais 5 g de levedura (L) e 10 g de E mais 5 g de L por animal por dia. Todos os animais receberam a mesma dieta, constituída de 65% de silagem (50% de milho:50% de sorgo) e 35% de concentrado composto de milho (24,6%), farelo de algodão (7,4%), uréia (1,2%), sal mineralizado (0,54%) e calcário (0,86%). Esta dieta apresentava 12,4% de PB; 10,1 MJEM/kg MS e 41,1% de FDN. A adição de enzima mais levedura não alterou o consumo de MS (3,31% do PV ou 126,6 g/kg PV0,75), e CDA da MS (63,0%), PB (68,2%), EE (83,3%), CHOT (61,3%), FDN (47,2%), FDA (43,8%) e valor de NDT (62,8%). O GMD e o CMS diminuíram de forma quadrática e a CA alimentar piorou linearmente, em função dos dias de confinamento. O fornecimento de enzima mais levedura para bovinos de corte não traz benefícios nutricionais ou de desempenho.

Abordagem clínica da atividade de trabalho do cozinheiro: interação de saberes, gênero profissional e inovação criativa

The focus of this dissertation is the study of work activities developed in the context of professional occupations characterized by varied previous schooling levels amongst those that work in them, and, at the same time, a high degree of complexity related to the typical tasks performed in the context of such professional practices. This dissertation intends to investigate the cook s professional activity, based on data from a determined specific professional genre in Natal (RN), in order to establish aspects related not only to the activity performed (activity which manifests itself empirically in registered behaviors), but also related to the real aspects of the work activity, that also compromises the non-realized options of the guiding of professional activity, be it by a matter of choice, be it due to the activity s own impediment. In this context, we tried to evaluate how much the professional activity observed keeps in relation to the reference practices of the professional genre, be it in terms of conformity, be it in terms of innovation (stylization) in relation to this genre. In addition, we tried to verify the contribution of the school and extra-school knowledge to the professional activity observed. Such work plan took on a preliminary step of the description of the socialprofessional profile of a cook in the city of Natal (RN), followed by a step of clinical labor approach, specifically utilizing as a methodological tool the simple and crossed self-confrontation procedure guided by the francophone theoretical referential of the Activity Clinic. The preliminary step in the description of profile of cooks from Natal (RN), of which 138 cooks took part in, evidenced three professional groupings, all predominantly masculine in their composition and fundamentally differentiated amongst each other by the time of professional activity, schooling type and time, work place and salary. The clinical approach step, composed by a pair of cooks, allowed us to verify elements of the cooks subordination to the professional genre, but also evidences of individual innovation (stylization) by these cooks, as well as the predominance of usage of extra-school knowledge when compared to school knowledge. We tried, in this step, to demonstrate how much the inclusion and submission to the genre dynamic, coordinated with the stylization initiatives, was able to contribute to the maintenance and amplification of the cook s power of acting in his professional practice.

Estudo teórico QTAIM e DFT dos compostos de coordenação: efeito quelato, titanocenos e ligação química

This work is a study of coordination compounds by quantum theory of atoms in molecules (QTAIM), based on the topological analysis of the electron density of molecular systems, both theoretically and experimentally obtained. The coordination chemistry topics which were studied are the chelate effect, bent titanocene and chemical bond in coordination complexes. The chelate effect was investigated according to topological and thermodynamic parameters. The exchange of monodentate ligands on polydentate ligands from same transition metal increases the stability of the complex both from entropy and enthalpy contributions. In some cases, the latter had a higher contribution to the stability of the complex in comparison with entropy. This enthalpic contribution is explained according to topological analysis of the M-ligand bonds where polidentate complex had higher values of electron density of bond critical point, Laplacian of electron density of bond critical point and delocalization index (number of shared electrons between two atoms). In the second chapter, was studied bent titanocenes with bulky cyclopentadienyl derivative π-ligand. The topological study showed the presence of secondary interactions between the atoms of π-ligands or between atoms of π-ligand and -ligand. It was found that, in the case of titanocenes with small difference in point group symmetry and with bulky ligands, there was an nearly linear relationship between stability and delocalization index involving the ring carbon atoms (Cp) and the titanium. However, the titanocene stability is not only related to the interaction between Ti and C atoms of Cp ring, but secondary interactions also play important role on the stability of voluminous titanocenes. The third chapter deals with the chemical bond in coordination compounds by means of QTAIM. The quantum theory of atoms in molecules so far classifies bonds and chemical interactions in two categories: closed shell interaction (ionic bond, hydrogen bond, van der Waals interaction, etc) and shared interaction (covalent bond). Based on topological parameters such as electron density, Laplacian of electron density, delocalization index, among others, was classified the chemical bond in coordination compounds as an intermediate between closed shell and shared interactions

Síntese e caracterização de compostos de coordenação homolépticos e heterolépticos com o ligante ácido kójico

The present work has as main objective to contribute to the coordination chemistry of the ligand kojic acid, with the synthesis and characterization of the homoleptic compounds [Al(kj)3], [Fe(kj)3], [Fe(kj)2], [Cu(kj)2] e [Ru(kj)3], and the new heteroleptic complexes, trans- K2[Fe(kj)2(CN)2] and trans-Na2[Ru(kj)2(CN)2]. The obtained compounds were characterized by vibrational spectroscopy in the infrared region (IV) and Electronic spectroscopy in the ultraviolet and visible region (Uv-Vis). The infrared results indicated the coordination of the bidentate ligand kojic acid, due to reductions in the values of the stretching frequencies of the carbonyl and double bonds, compared to the free ligand for all complexes obtained. The presence of new vibrational modes indicated the change of symmetry of the molecules in the new compounds synthesized. Additionally, the presence of vibrational modes assigned to metal-oxygen also contributed to confirm the ligand coordinating to the metal ions. Through this technique, was also possible to perform correlations of the numbers of vibrational modes, in the region 1400-900 cm-1 and the compounds geometry. The heteroleptic compounds exhibited υC≡N in 2065 and 2053 cm-1, respectively, for the trans-K2[Fe(kj)2(CN)2] and trans-Na2[Ru(kj)2(CN)2], indicating coordination of the cyano ligand to metal ions FeII e RuII. Comparing the obtained values with literature data was possible to identify the complex isomerism as trans. In relation to the results of electronic spectroscopy, studies of pH variation of kojic acid provided information on the distribution of electron density in the molecule, showing characteristic spectral profile of kojic ion and its protonated form (Hkj, kojic acid), with two bands at 215 and 269 nm, or deprotonated (kj-), with bands at 226 and 315 nm. The electronic spectra obtained for all complexes in aqueous medium, in the ultraviolet region, exhibited variations of the energies assigned to kojic acid intraligand transitions while in the visible region, only transitions assigned to charge transfer of iron and ruthenium complex have been identified

Aprendizagem na interação ensino-serviço-comunidade: a formação na perspesctiva dialógica com a sociedade

Considerando o papel do ensino superior em saúde para a sociedade brasileira, em que os egressos dos cursos ofertados na área serão os profissionais prestadores de serviços à população, este estudo objetivou analisar o componente ensino do PET-Saúde da Família - Natal-RN na formação de estudantes dos cursos de graduação em saúde da UFRN. Foi realizada pesquisa qualitativa com análise de documentos das disciplinas SACI e POTI datados entre 2009 e 2011 (portfólios, avaliações de desempenho e oficina de avaliação), mediante o auxílio do software Alceste© e análise de conteúdo, segundo Bardin. Na análise foi encontrado como potencialidades: o alunato trabalhando em grupo tutorial multidisciplinar, cuja interação e contato com a Unidade de Saúde da Família, incluídos os profissionais, bem como a comunidade, instiga nos aprendizes o diálogo consigo mesmo e com o outro, numa construção dos ser/agir no mundo. Os textos trabalhados durante as aulas permitem refletir e teorizar a respeito da realidade observada, auxiliando-os na identificação dos problemas e no traçar estratégias de intervenção. Já a observação da realidade reveste o aluno de humanização. Este passa a captar as necessidades e dificuldades enfrentadas pela comunidade observada. Nas fragilidades ficaram evidenciados: problemas de relações interpessoais entre os estudantes da SACI; a maioria dos projetos de intervenção ocorrendo numa perspectiva paternalista, reproduzindo o modelo de prestação de serviços na saúde mais praticado nas sociedades brasileiras; dificuldades em aprofundar no aprendiz, a importância da teorização dos assuntos; problemas de financiamento de projetos de intervenção; descumprimento do plano de ensino em alguns grupos tutoriais; e, por fim, dificuldades dos alunos e monitores em acompanhar as atividade de pesquisa e extensão do PET-Saúde, pela falta de integração dos projetos pedagógicos dos cursos. Conclui-se que o componente ensino do PET-Saúde da Família adota metodologias ativas de ensino na inserção de alunos na Atenção Primária em Saúde, proporcionando uma formação dentro de princípios éticos e humanísticos a partir do trabalho em equipe e da inclusão reflexiva dos alunos na Estratégia Saúde da Família. Apesar da existência de fragilidades concernentes às relações interpessoais, descompasso entre as proposições multiprofissionais e interdisciplinares da SACI e POTI e as dificuldades de pô-las em prática em currículos fragmentados e organizados por disciplinas pouco flexíveis, potencialmente, ao fim dessas experiências conectadas a Atenção Primária, os discentes apresentam uma nova visão do cuidado com a saúde, próxima às necessidades da população, iniciando uma tomada de postura crítica e reflexiva, entendendo-se com sujeitos ativos no construir a saúde coletivamente

Uma linguagem de modelagem da interação para auxiliar a comunicação designer-usuário

The development of interactive systems involves several professionals and the integration between them normally uses common artifacts, such as models, that drive the development process. In the model-driven development approach, the interaction model is an artifact that includes the most of the aspects related to what and how the user can do while he/she interacting with the system. Furthermore, the interactive model may be used to identify usability problems at design time. Therefore, the central problematic addressed by this thesis is twofold. In the first place, the interaction modeling, in a perspective that helps the designer to explicit to developer, who will implement the interface, the aspcts related to the interaction process. In the second place, the anticipated identification of usability problems, that aims to reduce the application final costs. To achieve these goals, this work presents (i) the ALaDIM language, that aims to help the designer on the conception, representation and validation of his interactive message models; (ii) the ALaDIM editor, which was built using the EMF (Eclipse Modeling Framework) and its standardized technologies by OMG (Object Management Group); and (iii) the ALaDIM inspection method, which allows the anticipated identification of usability problems using ALaDIM models. ALaDIM language and editor were respectively specified and implemented using the OMG standards and they can be used in MDA (Model Driven Architecture) activities. Beyond that, we evaluated both ALaDIM language and editor using a CDN (Cognitive Dimensions of Notations) analysis. Finally, this work reports an experiment that validated the ALaDIM inspection method

Mobile interact: uma ferramenta de auxílio didático proporcionando interação entre professores e alunos através de celulares

Education is one of the oldest activities practiced by man, but today it is still performed often without creating dialogues and discussions among all those involved, and students are passives agents without interactivity with teachers and the content approached. This work presents a tool used for providing interactivity in educational environments using cell phones, in this way, teachers can use technology to assist in process of education and have a better evaluation of students. The tool developed architecture is shown, exposing features of wireless communication technologies used and how is the connection management using Bluetooth technology, which has a limited number of simultaneous connections. The details of multiple Bluetooth connections and how the system should behave by numerous users are displayed, showing a comparison between different methods of managing connections. Finally, the results obtained with the use of the tool are presented, followed by the analysis of them and a conclusion on the work

Avaliação do Uso de Smartphones na Interação com as Aplicações da Televisão Digital Brasileira

Brazil is going through the process from analogical transmission to digital transmission. This new technology, in addition to providing a high quality audio and video, also allows applications to execute on television. Equipment called Set-Top Box are needed to allow the reception of this new signal and create the appropriate environment necessary to execute applications. At first, the only way to interact with these applications is given by remote control. However, the remote control has serious usability problems when used to interact with some types of applications. This research suggests a software resources implementation capable to create a environment that allows a smartphone to interact with applications. Besides this implementation, is performed a comparative study between use remote controle and smartphones to interact with applications of digital television, taking into account parameters related to usability. After analysis of data collected by the comparative study is possible to identify which device provides an interactive experience more interesting for users

Interação entre a analgesia de parto e o seu resultado: avaliação pelo peso e índice de Apgar do recém-nascido

JUSTIFICATIVA E OBJETIVOS: Existem controvérsias quanto à possibilidade de a analgesia de parto interferir no andamento do trabalho de parto e na vitalidade do recém-nascido. O objetivo deste estudo foi a interação entre analgesia do parto pelas técnicas peridural contínua e duplo bloqueio, com pequena dose de anestésico local, e o tipo de parto ocorrido, pela análise do peso e índice de Apgar do recém-nascido. MÉTODO: Analisaram-se, prospectivamente, os resultados de 168 analgesias de parto (janeiro de 2002 a janeiro de 2003), divididas em quatro grupos: G1 (n = 58) peridural contínua e evolução para parto vaginal; G2 (n = 69) duplo bloqueio e evolução para parto vaginal; G3 (n = 25) peridural contínua e evolução para cesariana; G4 (n = 16) duplo bloqueio e evolução para cesariana. Para G1 foi administrada ropivacaína a 0,125% (12 a 15 mL), para G2, bupivacaína a 0,5% (0,5 a 1 mL), sufentanil (10 mg), por via subaracnóidea. Administrou-se ropivacaína a 0,5%, por via peridural, para o parto vaginal (8 mL) e para cesariana (20 mL). Avaliaram-se idade, peso, altura, índice de massa corpórea (IMC), idade gestacional (IG), paridade e complicações (hipotensão arterial, bradicardia e hipóxia), e, do recém-nascido, peso e índice de Apgar (1º, 5º e 10º min). RESULTADOS: A maioria das parturientes era primigesta, com gestação de termo (uma IG de 28 semanas e nenhum pós-datismo), com peso, G2 < G4, e, IMC, G2 £ G4. Para o peso do RN, G1 < G3 e G2 < G4, e o Apgar do 1º min, G1 > G3. CONCLUSÕES: As técnicas de analgesia, peridural contínua e duplo bloqueio, com pequenas doses de anestésico local, não apresentaram interação com o resultado do parto, se a análise estiver focalizada no peso e no índice de Apgar do recém-nascido.