1,720,961 research outputs found
Lagrangian stability for a system of non-local continuity equations under Osgood condition
No full textWe extend known existence and uniqueness results of weak measure solutions for systems of non-local continuity equations beyond the usual Lipschitz regularity. Existence of weak measure solutions holds for uniformly continuous vector fields and convolution kernels, while uniqueness follows from a Lagrangian stability estimate under an additional Osgood condition
Weak-strong uniqueness and vanishing viscosity for incompressible Euler equations in exponential spaces
Full text linkIn the class of admissible weak solutions, we prove a weak-strong uniqueness result for the incompressible Euler equations assuming that the symmetric part of the gradient belongs to Lloc1([0,+∞);Lexp(Rd;Rd×d)), where Lexp denotes the Orlicz space of exponentially integrable functions. Moreover, under the same assumptions on the limit solution to the Euler system, we obtain the convergence of vanishing-viscosity Leray–Hopf weak solutions of the Navier–Stokes equations
The Selective Catalytic Reduction of NO with C3H8 on Cu-S-1, Cu-ZSM-5, Cu-[Fe]-ZSM-5, Fe-ZSM-5 and H-[Fe]-ZSM-5 Catalysts
No full textExistence and stability of weak solutions of the Vlasov-Poisson system in localised Yudovich spaces
Full text linkWe consider the Vlasov-Poisson system both in the repulsive (electrostatic potential) and in the attractive (gravitational potential) cases. Our first main theorem yields the analog for the Vlasov-Poisson system of Yudovich’s celebrated well-posedness theorem for the Euler equations: we prove the uniqueness and the quantitative stability of Lagrangian solutions f = f ( t , x , v ) whose associated spatial density ρ f = ρ f ( t , x ) is potentially unbounded but belongs to suitable uniformly-localised Yudovich spaces. This requirement imposes a condition of slow growth on the function p ↦ ‖ ρ f ( t , ⋅ ) ‖ L p uniformly in time. Previous works by Loeper, Miot and Holding-Miot have addressed the cases of bounded spatial density, i.e. ‖ ρ f ( t , ⋅ ) ‖ L p ≲ 1 , and spatial density such that ‖ ρ f ( t , ⋅ ) ‖ L p ∼ p 1 / α for α ∈ [ 1 , + ∞ ) . Our approach is Lagrangian and relies on an explicit estimate of the modulus of continuity of the electric field and on a second-order Osgood lemma. It also allows for iterated-logarithmic perturbations of the linear growth condition. In our second main theorem, we complement the aforementioned result by constructing solutions whose spatial density sharply satisfies such iterated-logarithmic growth. Our approach relies on real-variable techniques and extends the strategy developed for the Euler equations by the first and fourth-named authors. It also allows for the treatment of more general equations that share the same structure as the Vlasov-Poisson system. Notably, the uniqueness result and the stability estimates hold for both the classical and the relativistic Vlasov-Poisson systems
Preparation, characterisation and catalytic activity of Cu-Zn-based manganites obtained from carbonate precursors
No full textThe NO and N2O selective catalytic reduction on copper and iron containing ZSM-5 catalysts: a comparative study
No full textIn this work a comparison among the activities of H-ZSM-5, H-[Fe]-ZSM-5, Cu-[Fe]-ZSM-5, Cu-ZSM-5 and Fe-ZSM-5 catalysts for the selective catalytic reduction (SCR) of NO and N2O by C3H8 in presence of excess oxygen is reported. The results show that the activity for the NO reduction increases as iron and copper are loaded in the parent materials, i.e. H-ZSM-5 ca.=H-[Fe]-ZSM-5 < Fe-ZSM-5 < Cu-ZSM-5 ca.=Cu-[Fe]-ZSM-5. In the case of N2O reduction the order of activity changed as follows: H-ZSM-5 < Cu-ZSM-5 ca.= Cu-[Fe]-ZSM-5 < Fe-ZSM-5 < H-[Fe]-ZSM-5. In order to provide a more comprehensive picture of the catalytic behaviour, some catalytic results concerning the N2O decomposition are also presented
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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