Instability zones for satellites of asteroids: The example of the (87) Sylvia system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Uma escola para homem rural: a cultura popular, os camponeses e o movimento de educação de base (1960-1964)

Nos idos dos anos 1960, a intervenção sobre a cultura popular tornou-se um suposto da ação política de agentes modernizadores da sociedade brasileira. Por meio da Conferência Nacional dos Bispos do Brasil (CNBB), a Igreja Católica elaborou um projeto educacional de dimensão nacional, articulando suas emissoras de rádio no território brasileiro aos centros de educação radiofônica rural e criando, em 1961, o Movimento de Educação de Base (MEB). Os pressupostos teóricos e filosóficos do Movimento transcendiam as questões do aprendizado formal e pautavam-se por estratégias de ação da Igreja sobre os problemas de crescimento econômico e desenvolvimento social das regiões pobres brasileiras. O artigo em questãoversa sobre o camponês que participou do MEB e suas experiências escolares, avaliando os preceitos de educação rural, educação cívica e alfabetização de adultos propostos na ação dos agentes e das instituições modernizadoras do campo brasileiro. Analisamos os processos de assimilação e resistência do camponês aos princípios e projetos modernizantes externos à sua cultura. Novos ritmos de tempo, novas representações e novos significados foram introduzidos pela escola sobre práticas culturais seculares do campesinato brasileiro. No MEB, tal fenômeno resultou tanto na assimilação dos novos estímulos trazidos pela escola, quanto na insurreição de costumes e hábitos interligados às funções ritualísticas e costumeiras do indivíduo e/ou da comunidade rural.

Cafeicultura científica globalizada e as montanhas capixabas: a produção de caféarábica nas regiões do Caparaó e Serrana do Espírito Santo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Defining Issues Test-2: fidedignidade da versão brasileira e ponderações acerca de seu uso em pesquisas sobre moralidade

Este estudo teve como objetivo avaliar a fidedignidade da tradução e adaptação brasileira do Definig Issues Test (DIT) -2, assim como realizar algumas ponderações sobre a utilização desse instrumento e do DIT -1 em pesquisas sobre moralidade. Os testes DIT-1 e DIT-2 foram aplicados em 621 jovens brasileiros, proporcionalmente distribuídos conforme a cidade de procedência (Floriano/PI, Erechim/RS e Marília/SP), o tipo de escola (pública e particular) e o ano escolar freqüentado (8º ano do ensino fundamental e 3º ano do ensino médio). em relação à fidedignidade, notou-se que, apesar de os valores alcançados serem próximos àquele obtido na tradução e adaptação do DIT-1, revelam-se bem menores que os verificados nas versões originais americanas. Na verificação das pontuações alcançadas nos testes, foi observada a existência de tendências distintas no interior da amostra investigada, marcadas pelas variáveis controladas. Foram tecidas considerações sobre a validade e a interpretação desses testes.

Limites e contradições da cidadania na sociedade capitalista

O artigo defende o argumento de que a lógica objetiva das relações sociais capitalistas opõe-se ao desenvolvimento da moral e da cidadania. Também argumenta que a cidadania é uma representação idealizada que não tem força para superar a alienação das relações sociais, que têm o dinheiro como mediação universal em nossa sociedade. Por fim, o artigo analisa criticamente a proposta curricular do Estado de São Paulo para o ensino de filosofia no Ensino Médio, a qual tem como referência a pedagogia das competências.

THE REDUCTIVE PERTURBATION METHOD AND THE KORTEWEG-DE VRIES HIERARCHY

By using the reductive perturbation method of Taniuti with the introduction of an infinite sequence of slow time variables tau(1), tau(3), tau(5), ..., we study the propagation of long surface-waves in a shallow inviscid fluid. The Korteweg-de Vries (KdV) equation appears as the lowest order amplitude equation in slow variables. In this context, we show that, if the lowest order wave amplitude zeta(0) satisfies the KdV equation in the time tau(3), it must satisfy the (2n+1)th order equation of the KdV hierarchy in the time tau(2n+1), With n = 2, 3, 4,.... AS a consequence of this fact, we show with an explicit example that the secularities of the evolution equations for the higher-order terms (zeta(1), zeta(2),...) of the amplitude can be eliminated when zeta(0) is a solitonic solution to the KdV equation. By reversing this argument, we can say that the requirement of a secular-free perturbation theory implies that the amplitude zeta(0) satisfies the (2n+1)th order equation of the KdV hierarchy in the time tau(2n+1) This essentially means that the equations of the KdV hierarchy do play a role in perturbation theory. Thereafter, by considering a solitary-wave solution, we show, again with an explicit, example that the elimination of secularities through the use of the higher order KdV hierarchy equations corresponds, in the laboratory coordinates, to a renormalization of the solitary-wave velocity. Then, we conclude that this procedure of eliminating secularities is closely related to the renormalization technique developed by Kodama and Taniuti.

Some comments on the F ring-Prometheus-Pandora environment

The system formed by the F ring and two close satellites, Prometheus and Pandora, has been analysed since the time that Voyager visited the planet Saturn. During the ring plane crossing in 1995 the satellites were found in different positions as predicted by the Voyager data. Besides the mutual effects of Prometheus and Pandora, they are also disturbed by a massive F ring. Showalter et al. [Icarus 100 (1992) 394] proposed that, the core of the ring has a mass which corresponds to a moonlet varying in size from 15 to 70 kin in radius which can prevent the ring from spreading due to dissipative forces, such as Poynting-Robertson drag and collisions. We have divided this work into two parts. Firstly we analysed the secular interactions between Prometheus-Pandora and a massive F ring using the secular theory. Our results show the variation in eccentricity and inclination of the satellites and the F ring taking into account a massive ring corresponding to a moonlet of different sizes. There is also a population of dust particles in the ring in the company of moonlets at different sizes [Icarus 109 (1997) 304]. We also analysed the behaviour of these particles under the effects of the Poynting-Robertson drag and radiation pressure. Our results show that the time scale proposed for a dust particle to leave the ring is much shorter than predicted before even in the presence of a coorbital moonlet. This result does not agree with the confinement model proposed by Dermott et al. [Nature 284 (1980) 309]. In 2004, Cassini mission will perform repeated observations of the whole system, including observations of the satellites and the F ring environment. These data will help us to better understand this system. (C) 2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

Legitimacy and context: Implications for public sector reform in developing countries

This article examines the interplay between legitimacy and context as key determinants of public sector reform outcomes. Despite the importance of variables Such as legitimacy of public institutions, levels of civic morality and socio-economic realities, reform strategies often fail to take such contextual factors into account. The article examines, first, relevant literature both conceptual and empirical, including data from the World Values Survey project. It is argued that developing countries have distinctive characteristics which require particular reform strategies. The data analysed shows that in Latin American countries, there is no clear Correlation between confidence in public institutions and civic morality. Other empirical studies show that unemployment has a negative impact on the level of civic morality, while inequality engenders corruption. This suggests that poorer and socio-economically stratified countries face greater reform challenges owing to the lack of legitimacy of public institutions. The article concludes that reforms should focus on areas of governance that impact on poverty. This will in turn help produce more stable outcomes. Copyright (C) 2008 John Wiley & Sons, Ltd.

On the first nu(6) anti-aligned librating asteroid family of Tina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of the resonance in a gravity-gradient stabilized satellite

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Boussinesq solitary-wave as a multiple-time solution of the Korteweg-de Vries hierarchy

We study the Boussinesq equation from the point of view of a multiple-time reductive perturbation method. As a consequence of the elimination of the secular producing terms through the use of the Korteweg-de Vries hierarchy, we show that the solitary-wave of the Boussinesq equation is a solitary-wave satisfying simultaneously all equations of the Korteweg-de Vries hierarchy, each one in an appropriate slow time variable. © 1995 American Institute of Physics.

The Korteweg-de Vries hierarchy and long water-waves

By using the multiple scale method with the simultaneous introduction of multiple times, we study the propagation of long surface-waves in a shallow inviscid fluid. As a consequence of the requirements of scale invariance and absence of secular terms in each order of the perturbative expansion, we show that the Korteweg-de Vries hierarchy equations do play a role in the description of such waves. Finally, we show that this procedure of eliminating secularities is closely related to the renormalization technique introduced by Kodama and Taniuti. © 1995 American Institute of Physics.

Linearizability of the perturbed Burgers equation

We show in this report that the perturbed Burgers equation ut = 2uux + uxx + ε(3 α1u2ux + 3 α2uuxx + 3 α3u2 x + α4uxxx) is equivalent, through a near-identity transformation and up to O(ε), to a linearizable equation if the condition 3 α1 - 3 α3 - 3/2α2 + 3/2α4 = 0 is satisfied. In the case this condition is not fulfilled, a normal form for the equation under consideration is given. We show, furthermore, that nonlinearizable cases lead to perturbative expansions with secular-type behavior. Then, to illustrate our results, we make a linearizability analysis of the equations governing the dynamics of a one-dimensional gas.

Vibrational-rotational structure of supersingular plus Coulomb potential A/r4 - Z/r*

The vibrational-rotational states of the supersingular plus Coulomb potential A/r4 - Z/r are variationally constructed using a nonorthogonal basis of atomic hydrogenic eigenfunctions modulated by an exponential factor exp(- α/r), ensuring the correct behavior in the vicinity of the supersingularity. The construction is carried out in two successive stages. The first stage is restricted to trial functions without radial nodes, leading to a variational optimization of the parameters of the basis for each value of the angular momentum. The second stage uses the complete basis to construct linear trial functions and to formulate the variational problem in terms of secular equations, yielding the successive vibrational and rotational states. Numerical results for the corresponding energy levels are presented for different combinations of the intensity parameters of the potential. © 2001 Plenum Publishing Corporation.

Analytical direct planetary perturbations on the orbital motion of satellites

An analytical expansion of the disturbing function arising from direct planetary perturbations on the motion of satellites is derived. As a Fourier series, it allows the investigation of the secular effects of these direct perturbations, as well as of every argument present in the perturbation. In particular, we construct an analytical model describing the evection resonance between the longitude of pericenter of the satellite orbit and the longitude of a planet, and study briefly its dynamic. The expansion developed in this paper is valid in the case of planar and circular planetary orbits, but not limited in eccentricity or inclination of the satellite orbit. © 2012 Springer Science+Business Media Dordrecht.