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Search Results: 1 - 10 of 238786 matches for " D.;Silva "
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Multiplicity of Solutions for Gradient Systems Using Landesman-Lazer Conditions
Edcarlos D. da Silva
Abstract and Applied Analysis , 2010, DOI: 10.1155/2010/237826
Abstract: We establish existence and multiplicity of solutions for an elliptic system which presents resonance at infinity of Landesman-Lazer type. In order to describe the resonance, we use an eigenvalue problem with indefinite weights. In all results, we use Variational Methods, Morse Theory and Critical Groups. 1. Introduction In this paper, we discuss results on existence and multiplicity of solutions for the system where is bounded smooth domain in , with and . We assume that the system (1.1) is of gradient type, that is, there is some function such that . Throughout this paper, denotes the gradient in the variables and for each fixed. From a variational standard point of view, to find weak solutions of (1.1) in is equivalent to find critical points of the functional given by where denotes the Dirichlet norm We observe that the problem (1.1) represents a steady state case of reaction-diffusion systems of interest in Biology, Chemistry, Physics, and Ecology; see [1, 2]. In order to define the resonance conditions, we need to consider eigenvalue problems for functions , where denotes the set of all matrices of order 2. Let us denote by the set of all continuous, cooperative, and symmetric functions of order 2 written as satisfying the following hypotheses. is cooperative, that is, for all Moreover, we assume that has zero Lebesgue measure. There is such that or In this way, given , we consider the eigenvalue problem with weights as follows: Using the conditions and above and applying the Spectral Theory for compact operators, we get a sequence of eigenvalues such that as . Here, each eigenvalue ; see [3–5]. We point out that the Problem (1.1) presents a resonance phenomenon depending on the behavior of the functions and at infinity. We assume all along this paper the following basic hypothesis. There is such that Under these hypotheses, system (1.1) is asymptotically quadratic at infinity due to the presence of a linear part given by the function . In addition, when for some the problem (1.1) becomes resonant. In this case, in order to obtain existence and multiplicity of solutions for (1.1), we will assume conditions of the Landesman-Lazer type introduced in the scalar case in [6]. These famous conditions are well known in the scalar case. However for gradient systems, to the best our knowledge, these conditions have not been explored in our case. In order to introduce our Landesman-Lazer conditions for system (1.1), we need the following auxiliary assumptions. There are functions such that Moreover, there are functions such that where the limits in (1.9) and
Dynamic evaluation for liquid tracer in a trickle bed reactor
Silva, J. D.;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2011, DOI: 10.1590/S1678-58782011000300002
Abstract: a mathematical model is developed for a liquid flow on solid particles in a trickle bed reactor. a mathematical formulation is followed based on the liquid-solid model approach where the liquid phase with the (kcl) tracer is treated as a continuum. the physical modeling is discussed, including the formulation of initial and boundary conditions and the description of the solution methodology. results of mathematical model are presented and validated. the model is validated through comparison using three experimental cases. the optimized values of the axial dispersion (dax), liquid-solid mass transfer (kls), and partial wetting efficiency (fm) coefficients are obtained simultaneously using the objective function. the behavior of dax, kls, and fm is analyzed by the empirical correlations.
El no lugar de la música indigenista en Chile: hacia una etnomusicología de la soledad
Díaz Silva,Rafael;
Aisthesis , 2009, DOI: 10.4067/S0718-71812009000100012
Abstract: the article focuses on the analysis of the new cultural places raised within contemporary society, which affects musical expressions attached to aboriginal cultures in chile. the article claims that, next to the socio-aesthetical diasporas of indigenous musical performance, a parallel shift is being produced, from ritualistic places to spaces where no artistic expressions had been before hypermodernity. this reconfiguration of space is a new challenge to ethnomusicology because nowadays, not only the study of new forms of ethnic art in an intercultural context is required, but also the inclusion of the anthropological place. this modifies the aspects (and specters) of oral art and relocates the researcher in a new coordinate, the ?non-place?.
Recombinant Technology and Probiotics
Icy DSilva
International Journal of Engineering and Technology , 2011,
Abstract: Recombinant technology has led the way to monumental advances in the development of useful molecules, including the development of safe probiotics. The development of novel approaches using recombinant technology and probiotics that allow accurate targeting of therapeutics to the mucosa is an interesting area of research. The creation and use of recombinant probiotics expressing recombinantovalbumin, recombinant ovalbumin mutants and yet-to-be-designed recombinant hypo/non-allergenic molecules offer the opportunity to further investigate their effects for food, nutrition, environment andhealth. This review highlights advances in native probiotics and recombinant probiotics expressing native and recombinant molecules for food, nutrition, environment and health.
(Re) significando a solidariedade na velhice: para além de la os consanguíneos = (Re) meaning the solidarity in the old age: beyond consanguineous ties
Raimunda Silva D’ Alencar
Acta Scientiarum : Human and Social Sciences , 2012,
Abstract: O envelhecimento da popula o brasileira vem promovendo altera es substanciais em múltiplas dimens es da vida e, particularmente, nas rela es familiares e extrafamiliares. As aceleradas mudan as sociais impactam diretamente as configura es das famílias e produzem descontinuidades de afetos e solidariedades. à medida que a velhice se estabelece, os idosos reelaboram essas rela es sob novas bases, ajustam-se às novas realidades, mas sem acomoda es e avan am na constru o e diversifica o de novos la os e solidariedades, costurando cuidadosamente as diferen as internas entre filhos, netos, noras e genros, e projetando para outros espa os aquilo que entendem como perdido: carinho, afeto, aten o, respeito. Extrapolando as famílias consanguíneas, os idosos buscam os grupos de convivência, que exercem fun es fundamentais n o apenas por substituírem, em muitos casos, a já instalada ausência de familiares, mas também por preencherem espa os que a sociedade, de um modo geral, tem deixado vazios para quem envelhece. The aging of the brazilian population has been making substantial changes in multiple dimensions of life, and particularly in familiar and extra-familiar relationships. The accelerated social changes impact directly on familiar configurations and produce discontinuities of affection and solidarity. To the extent that aging is established, the elderly reconstruct the familiar relationships under new bases, fit to the new realities, but without accommodations, and advance in the construction and diversification of new ties and solidarities, carefully tailoring the internal differences between children, grandchildren, daughters-in-law and sons-in-law, and designing for others spaces what it means lost: fondness, affection, autonomy, attention, respect. Extrapolating from consanguineous families, the elderly seek the support groups, which exercise fundamental functions not only by replacing, in many cases, the absence of family members already in place, but for filling spaces that the society, in general, has left empty for those ages.
El no lugar de la música indigenista en Chile: hacia una etnomusicología de la soledad The Non-place of the Indigenous Music in Chile: towards an Ethnomusicology of Loneliness
Rafael Díaz Silva
Aisthesis , 2009,
Abstract: El artículo se centra en el estudio de los nuevos espacios que surgen en la sociedad contemporánea, para manifestaciones musicales adscritas a los pueblos originarios de Chile. Se sostiene que, junto con la diaspora socio-estética de la performática musical indígena, se ha producido paralelamente el desplazamiento de sus espacios rituales hacia sitios en donde ninguna actividad artística había encontrado su lugar antes del advenimiento de la sobremodernidad. Esta reconfiguración espacial ofrece nuevos retos para la etnomusicología. Ya no sólo se trata del desafío de estudiar nuevas formas de arte étnico en un contexto intercultural, sino también de incluir el complejo parámetro del lugar antropológico, que modifica los aspectos (y espectros) del arte oral y que resitúa al investigador en una nueva coordenada, la del no-lugar . The article focuses on the analysis of the new cultural places raised within contemporary society, which affects musical expressions attached to aboriginal cultures in Chile. The article claims that, next to the socio-aesthetical Diasporas of indigenous musical performance, a parallel shift is being produced, from ritualistic places to spaces where no artistic expressions had been before hypermodernity. This reconfiguration of space is a new challenge to Ethnomusicology because nowadays, not only the study of new forms of ethnic art in an intercultural context is required, but also the inclusion of the anthropological place. This modifies the aspects (and specters) of oral art and relocates the researcher in a new coordinate, the non-place .
El aporte a la Química Iberoamericana del doctor Alfonso Romo de Vivar. Asegurar la inmortalidad de la ciencia para así perpetuar la humanidad
Mario Silva Ph. D.
Revista de la Sociedad Química de México , 2003,
Abstract:
Multiplicity of solutions for gradient systems
Edcarlos D. Da Silva
Electronic Journal of Differential Equations , 2010,
Abstract: We establish the existence of nontrivial solutions for an elliptic system which is resonant both at the origin and at infinity. The resonance is given by an eigenvalue problem with indefinite weight, and the nonlinear term is permitted to be unbounded. Also, we consider the case where the resonance at infinity and at the origin can occur with different weights. Our main tool is the computation of critical groups.
L’écologie est en deuil : Pierre Dansereau 1911-2011 Mourning ecology: Pierre Dansereau 1911-2011 A ecologia está de luto : Pierre Dansereau 1911-2011
D. Sampaio da Silva
Confins , 2011, DOI: 10.4000/confins.7325
Abstract: L’éminent scientifique Pierre Dansereau s’est éteint à l’age de 99 ans. Dès le début de sa carrière, il a défendu une nouvelle perspective écologique basée sur l’analyse des interrelations entre les agents des écosystèmes où l’homme occupe une place à part entière. Son originalité a fait de Dansereau un précurseur de ce qu’est aujourd’hui le développement durable. Son uvre est riche d’enseignements pour penser la crise écologique actuelle ainsi que les possibilités d’en sortir. Elle est marquée en effet par la nécessité de repenser la relation entre l’humanité et son environnement. The eminent scientist Pierre Dansereau died before his centennial. Since the beginning of his career, he has defended a new ecological perspective based on the analysis of the interrelationships between the different agents in an ecosystems wherehuman beings occupy a place of their own. Dansereau’s originality made him the precursor of sustainable development. His work is rich and instructive to understand the current ecological crisis and the opportunities to get out of it. Indeed, this crisis is marked by the need to rethink the relationship between humanity and environment. O eminente cientista Pierre Dansereau faleceu nas vésperas do seu centenário. Desde o início da sua carreira, ele defendeu uma nova perspectiva ecológica baseada na análise das interrela es entre os agentes dos ecossistemas onde o homem ocupa um lugar próprio. Sua originalidade fez de Dansereau um precursor do que é hoje o desenvolvimento sustentável. Sua obra é rica e instrutiva para se pensar a crise écológica atual assim como as possibilidades para dela sair. Ela é na verdade marcada pela necessidade de repensar a rela o entre a humanidade e o meio ambiente.
EROs in the EIS Fields. I: The AXAF (Chandra) Deep Field
M. Scodeggio,D. Silva
Physics , 2000,
Abstract: The publicly available EIS-DEEP optical-NIR data for the AXAF (Chandra) Deep Field have been used to construct samples of Extremely Red Objects (EROs) using various single-band and multi-band color criteria. In this work we define as EROs objects with colors consistent with passively evolving elliptical galaxies at z $\geq$ 1. The EROs surface densities we derive are intermediate between previous published values, emphasizing again the need for larger survey areas to constrain the effects of possible large-scale structure. Although various single-color selected samples can be derived, the EROs sample selected using R-Ks > 5, I-Ks > 4, J-Ks > 1.8 jointly is likely to contain the highest fraction of passively evolving luminous field elliptical galaxies at z >= 1, or conversely, the lowest fraction of lower redshift interlopers. The surface density of this multi-band selected EROs sample is consistent with the conclusion that little or no field elliptical volume density evolution has occurred in the redshift range 0 > z > 1.5. However, extensive spectroscopic followup is necessary to confirm this conclusion.
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