7,459 research outputs found
Supercritical biharmonic equations with power-type nonlinearity
The biharmonic supercritical equation , where and
, is studied in the whole space as well as in a
modified form with as right-hand-side with an additional
eigenvalue parameter in the unit ball, in the latter case together
with Dirichlet boundary conditions. As for entire regular radial solutions we
prove oscillatory behaviour around the explicitly known radial {\it singular}
solution, provided , where
is a further critical exponent, which was introduced in a recent work by
Gazzola and the second author. The third author proved already that these
oscillations do not occur in the complementing case, where .
Concerning the Dirichlet problem we prove existence of at least one singular
solution with corresponding eigenvalue parameter. Moreover, for the extremal
solution in the bifurcation diagram for this nonlinear biharmonic eigenvalue
problem, we prove smoothness as long as
High-performance analog front-end (AFE) for EOG systems
Electrooculography is a technique for measuring the corneo-retinal standing potential of the human eye. The resulting signal is called the electrooculogram (EOG). The primary applications are in ophthalmological diagnosis and in recording eye movements to develop simple human–machine interfaces (HCI). The electronic circuits for EOG signal conditioning are well known in the field of electronic instrumentation; however, the specific characteristics of the EOG signal make a careful electronic design necessary. This work is devoted to presenting the most important issues related to the design of an EOG analog front-end (AFE). In this respect, it is essential to analyze the possible sources of noise, interference, and motion artifacts and how to minimize their effects. Considering these issues, the complete design of an AFE for EOG systems is reported in this work.info:eu-repo/semantics/publishedVersio
Benchmarking of debris flow experimental tests using combined finite-discrete element method, FEMDEM
A Model for Zebrafish Ventricular Action Potential
From the '90s, the interest in the use of zebrafish has exponentially grown thanks to the numerous characteristics, very close to the human ones, that make this little fish very attractive in different fields. Thus, zebrafish has been increasingly proposed as a pharmacological and genetic screening model. The growing interest and the relevance of this animal model motivate the development of a mathematical model of the action potential of the zebrafish to facilitate the understanding of the mechanisms associated with its electrophysiological behavior and how they correlated with those observed in humans. This work presents the first attempt to develop a mathematical model of the adult zebrafish action potential. The model is based on the Ten Tusscher formulation of the action potential of human cardiomyocyte in which the main currents have been reparametrized to be adapted to those of the zebrafish, while extending the model to account for the T-type calcium current present in the zebrafish. Preliminary results of the proposed model show an action potential morphology in good agreement with experimental data
Study of impact on helicopter blade
This article presents a study of damage in structures that are similar to helicopter blade sections, subjected to an impact. These complex composite structures were impacted by a steel ball of 125 g at impact speed ranging from 30 to 130 m/s. This led to properly highlight the kinematics of the impact and to define the sequence of the damage’s mechanisms. An explicit FE model is also presented. The damage modelling of the roving is performed through a scale change. It allows a good representation of observed experimental behaviour. As the mesh density is low, it can be used for the modelling of a real structure
Eurocode 7 and rock engineering design: The case of rockfall protection barriers
The Eurocode 7 or EC7 is the Reference Design Code (RDC) for geotechnical design including rock engineering design within the European Union (EU). Moreover, its principles have also been adopted by several other countries, becoming a key design standard for geotechnical engineering worldwide. It is founded on limit state design (LSD) concepts, and the reliability of design is provided mainly by a semi-probabilistic method based on partial factors. The use of partial factors is currently an advantage, mainly for the simplicity in its applicability, and a limitation, especially concerning geotechnical designs. In fact, the application of partial factors to geotechnical design has proven to be difficult. In this paper, the authors focus on the way to apply EC7 principles to rock engineering design by analyzing the design of rockfall protection structures as an example. A real case of slope subjected to rockfall is reported to outline the peculiarity connected to rock engineering. The main findings are related to the complementarity of the reliability-based design (RBD) approach within EC7 principles and the possibility of overcoming the limitations of a partial factor approach to this type of engineering problem
Eurocode 7 and rock engineering design: The case of rockfall protection barriers
The Eurocode 7 or EC7 is the Reference Design Code (RDC) for geotechnical design including rock engineering design within the European Union (EU). Moreover, its principles have also been adopted by several other countries, becoming a key design standard for geotechnical engineering worldwide. It is founded on limit state design (LSD) concepts, and the reliability of design is provided mainly by a semi-probabilistic method based on partial factors. The use of partial factors is currently an advantage, mainly for the simplicity in its applicability, and a limitation, especially concerning geotechnical designs. In fact, the application of partial factors to geotechnical design has proven to be difficult. In this paper, the authors focus on the way to apply EC7 principles to rock engineering design by analyzing the design of rockfall protection structures as an example. A real case of slope subjected to rockfall is reported to outline the peculiarity connected to rock engineering. The main findings are related to the complementarity of the reliability-based design (RBD) approach within EC7 principles and the possibility of overcoming the limitations of a partial factor approach to this type of engineering problem
Time-Dependent Gutzwiller Theory for Multiband Hubbard Models
Based on the variational Gutzwiller theory, we present a method for the
computation of response functions for multiband Hubbard models with general
local Coulomb interactions. The improvement over the conventional random-phase
approximation is exemplified for an infinite-dimensional two-band Hubbard model
where the incorporation of the local multiplet-structure leads to a much larger
sensitivity of ferromagnetism on the Hund coupling. Our method can be
implemented into LDA+Gutzwiller schemes and will therefore be an important tool
for the computation of response functions for strongly correlated materials.Comment: 4 pages, 3 figure
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