1,546 research outputs found
A non-autonomous scalar one-dimensional dissipative parabolic problem: The description of the dynamics
The purpose of this paper is to give a characterization of the structure of
non-autonomous attractors of the problem when the parameter varies. Also, we answer a
question proposed in [11], concerning the complete description of the structure
of the pullback attractor of the problem when and, more
generally, for , . We construct
global bounded solutions , "non-autonomous equilibria", connections between the
trivial solution these "non-autonomous equilibria" and characterize the
-limit and -limit set of global bounded solutions. As a
consequence, we show that the global attractor of the associated skew-product
flow has a gradient structure. The structure of the related pullback an uniform
attractors are derived from that.Comment: 32 pages, 04 figure
Maximally Localized States in Quantum Mechanics with a Modified Commutation Relation to All Orders
We construct the states of maximal localization taking into account a
modification of the commutation relation between position and momentum
operators to all orders of the minimum length parameter. To first order, the
algebra we use reproduces the one proposed by Kempft, Mangano and Mann. It is
emphasized that a minimal length acts as a natural regulator for the theory,
thus eliminating the otherwise ever appearing infinities. So, we use our
results to calculate the first correction to the Casimir Effect due to the
minimal length. We also discuss some of the physical consequences of the
existence of a minimal length, culminating in a proposal to reformulate the
very concept of "position measurement"
Lower semicontinuity of attractors for non-autonomous dynamical systems
This paper is concerned with the lower semicontinuity of attractors for semilinear
non-autonomous differential equations in Banach spaces. We require the unperturbed
attractor to be given as the union of unstable manifolds of time-dependent hyperbolic
solutions, generalizing previous results valid only for gradient-like systems in which
the hyperbolic solutions are equilibria. The tools employed are a study of the continuity
of the local unstable manifolds of the hyperbolic solutions and results on the continuity of
the exponential dichotomy of the linearization around each of these solutions
Nonlinear dynamical analysis for globally modified incompressible non-Newtonian fluids
We present the global modification of the Ladyzhenskaya equations, for incompressible non-Newtonian fluids. This modification is through a cut-off function that multiplies the
convective term of the equation and an additional artificial smoothing dissipation term as part of
the viscous term of the equation. The goal of this work is the comparative analysis between the
modified system and the non-modified system. Therefore, we show the existence and regularity
of weak solutions, the existence of global attractors, the estimation of the fractal dimension
of the global attractors, and finally, the relationship of the autonomous dynamics between the
modified system and the non-modified system
Mini-Project of Ethanol Production from Waste as a Teaching Methodology
The development of sustainable alternative fuel, energy and chemical products is happening
all over the world. Some of the main reasons for this increase are the increasing demand for fuel
and energy due to population growth and economic development; climate change and the need
for decreasing greenhouse gas (GHG) emissions; enhancement of waste recovery efforts to redirect
waste away from landfills and decrease the reliance on primary raw materials. Thus, it is important
to make students aware of these aspects and explore the development of alternative fuels, while
giving them the tools to be creative and autonomous.
The aim of this paper is to show how the implementation of a mini-project can improve not only
students’ knowledge about the production of a biofuel from waste, but also their development of the
theoretical and basic skills needed to carry out the mini-project.
This paper presents in addition to the methodology used, some results to the implementation of the
mini project, specifically the students’ points of view.info:eu-repo/semantics/publishedVersio
A taxonomic revision of the Neotropical termite genera Labiotermes Holmgren and Paracornitermes Emerson (Isoptera: Termitidae: Nasutitermitinae)
The taxonomy of the South American termite genus Labiotermes Holmgren (sensu novo) is revised,including identification keys to soldiers and workers, and distribution maps for all 10 species.Paracornitermes Emerson is treated as a new synonym of Labiotermes. Two new species aredescribed: L. guasu, from the Amazon rain forest and L. oreadicus, from the Cerrado of centralBrazil. Paracornitermes caapora Bandeira & Cancello and P. hirsutus Araujo are placed under thesynonymy of L. orthocephalus. The imagos of L. emersoni and L. orthocephalus are described forthe first time. The workers of all species are described and illustrated, including the enteric valve armature and the mixed segment. The soldiers of the species previously included inParacornitermes are redescribed.Fil: Constantino, Reginaldo. Universidade de Brasília; BrasilFil: Acioli, Agmo N. S.. PPG Entomologia; BrasilFil: Smith, Karen. Universidade de Brasília; BrasilFil: Cuezzo, Adriana Carolina. Fundación Miguel Lillo. Dirección de Zoología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Carvalho, Sergio H. C. Universidade de Brasília; BrasilFil: Vasconcellos, Alexandre. Universidade Federal do Rio Grande do Norte; Brasi
Vancomycin-Loaded, Nanohydroxyapatite-Based Scaffold for Osteomyelitis Treatment: In Vivo Rabbit Toxicological Tests and In Vivo Efficacy Tests in a Sheep Model
The treatment for osteomyelitis consists of surgical debridement, filling of the dead space, soft tissue coverage, and intravenous administration of antimicrobial (AM) agents for long periods. Biomaterials for local delivery of AM agents, while providing controllable antibiotic release rates and simultaneously acting as a bone scaffold, may be a valuable alternative; thus, avoiding systemic AM side effects. V-HEPHAPC is a heparinized nanohydroxyapatite (nHA)/collagen biocomposite loaded with vancomycin that has been previously studied and tested in vitro. It enables a vancomycin-releasing profile with an intense initial burst, followed by a sustained release with concentrations above the Minimum Inhibitory Concentration (MIC) for MRSA. In vitro results have also shown that cellular viability is not compromised, suggesting that V-HEPHAPC granules may be a promising alternative device for the treatment of osteomyelitis. In the present study, V-HEPHAPC (HEPHAPC with vancomycin) granules were used as a vancomycin carrier to treat MRSA osteomyelitis. First, in vivo Good Laboratory Practice (GLP) toxicological tests were performed in a rabbit model, assuring that HEPHAPC and V-HEPHAPC have no relevant side effects. Second, V-HEPHAPC proved to be an efficient drug carrier and bone substitute to control MRSA infection and simultaneously reconstruct the bone cavity in a sheep model.This work was financed by FEDER-Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020; by Portuguese funds through FCT/MCTES in the framework of the project institute for Research and Innovation in Health Sciences (POCI-01-0145-FEDER-007274); by the Project Biotherapies (NORTE-01-0145-FEDER-000012); and by the project HEPHAPC Program RESOLVE, Norte 2020 (NORTE-01-0246-FEDER-000018). The authors would also like to acknowledge the technical support for histology and histochemical studies of Rui Fernandes and Rossana Correia and all the staff from HEMS/i3S, as well as the support of all the staff and students at the Hospital Veterinario-Universidade de Evora
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