A degenerating PDE system for phase transitions and damage

In this paper, we analyze a PDE system arising in the modeling of phase transition and damage phenomena in thermoviscoelastic materials. The resulting evolution equations in the unknowns \theta (absolute temperature), u (displacement), and \chi (phase/damage parameter) are strongly nonlinearly coupled. Moreover, the momentum equation for u contains \chi-dependent elliptic operators, which degenerate at the pure phases (corresponding to the values \chi=0 and \chi=1), making the whole system degenerate. That is why, we have to resort to a suitable weak solvability notion for the analysis of the problem: it consists of the weak formulations of the heat and momentum equation, and, for the phase/damage parameter \chi, of a generalization of the principle of virtual powers, partially mutuated from the theory of rate-independent damage processes. To prove an existence result for this weak formulation, an approximating problem is introduced, where the elliptic degeneracy of the displacement equation is ruled out: in the framework of damage models, this corresponds to allowing for partial damage only. For such an approximate system, global-in-time existence and well-posedness results are established in various cases. Then, the passage to the limit to the degenerate system is performed via suitable variational techniques

A sub-mW IoT-endnode for always-on visual monitoring and smart triggering

This work presents a fully-programmable Internet of Things (IoT) visual sensing node that targets sub-mW power consumption in always-on monitoring scenarios. The system features a spatial-contrast $128\mathrm{x}64$ binary pixel imager with focal-plane processing. The sensor, when working at its lowest power mode ($10\mu W$ at 10 fps), provides as output the number of changed pixels. Based on this information, a dedicated camera interface, implemented on a low-power FPGA, wakes up an ultra-low-power parallel processing unit to extract context-aware visual information. We evaluate the smart sensor on three always-on visual triggering application scenarios. Triggering accuracy comparable to RGB image sensors is achieved at nominal lighting conditions, while consuming an average power between $193\mu W$ and $277\mu W$, depending on context activity. The digital sub-system is extremely flexible, thanks to a fully-programmable digital signal processing engine, but still achieves 19x lower power consumption compared to MCU-based cameras with significantly lower on-board computing capabilities.Comment: 11 pages, 9 figures, submitteted to IEEE IoT Journa

How to improve disease control in European organic viticulture

Organic agriculture and, in particular, organic viticulture have grown considerably in the last decade, nonetheless organic farming still has a huge potential for innovation and improved solutions. The research project VineMan.org (www.vineman-org.eu) aims at improving disease control, which is one of the main and most difficult tasks in oganic viticulture, by integrating plant resistance against fungal pathogens, vineyard management practices, and the use of biological control agents according to optimized outbreak forecasting systems

Global existence of strong solutions to the one-dimensional full model for phase transitions in thermoviscoelastic materials

summary:This paper is devoted to the analysis of a one-dimensional model for phase transition phenomena in thermoviscoelastic materials. The corresponding parabolic-hyperbolic PDE system features a {\it strongly nonlinear} internal energy balance equation, governing the evolution of the absolute temperature $\vartheta$, an evolution equation for the phase change parameter $\chi$, including constraints on the phase variable, and a hyperbolic stress-strain relation for the displacement variable ${\bf u}$. The main novelty of the model is that the equations for $\chi$ and ${\bf u}$ are coupled in such a way as to take into account the fact that the properties of the viscous and of the elastic parts influence the phase transition phenomenon in different ways. However, this brings about an elliptic degeneracy in the equation for ${\bf u}$ which needs to be carefully handled. \endgraf First, we prove a global well-posedness result for the related initial-boundary value problem. Secondly, we address the long-time behavior of the solutions in a simplified situation. We prove that the $\omega$-limit set of the solution trajectories is nonempty, connected and compact in a suitable topology, and that its elements solve the steady state system associated with the evolution problem

Ion Transport in Liver Mitochondria IV. THE RELATIONSHIP BETWEEN ION TRANSLOCATION AND ELECTRON TRANSPORT

Abstract Addition of small amounts of Ca++ to liver mitochondria incubated in the absence of phosphate or acetate results in an inhibition of respiration. The inhibition of respiration is reversed by increasing the concentration of substrate anions in the medium, and is enhanced by increasing the ionic strength or the pH of the medium. The H+:O and Ca++:O ratios are increased severalfold when measured under conditions of inhibited respiration. Furthermore, mitochondria which have entered a state of inhibited respiration continue to take up Ca++ and to release H+. It is concluded that the above stoichiometries in the absence of phosphate or acetate are determined by both uninhibited and inhibited respirations. The higher the concentration of Ca++, the larger is the contribution of the inhibited respiration. In the presence of acetate, the Ca++ to total oxygen ratio is in the region of 2.0 to 2.5 with succinate as substrate. The inhibition of respiration is related to the increase of the intramitochondrial pH as followed kinetically with the bromthymol blue technique. The bromthymol blue response is dependent on the rate of influx of anions. Increasing the ionic strength and pH enhances the bromthymol blue response, presumably by restraining the influx of anions. The mechanism by which the inhibition of respiration causes the superstoichiometric ratios is discussed

Come affinare le armi della seduzione: emozioni e vigilanza epistemica

Seduction is often seen as a deceptive strategic game, which hampers deliberation. However, in case of seduction, emotions play a central role in modulating communicated contents. In this sense, seduction is not a form of deception, but an impulse to know. How to provide a cognitive account of seduction able to distinguish it from deception? Within philosophical Western tradition, emotions have a negative role in deliberation as they are automatic, unconscious and obliged. In contrast with this tradition, Mascaro and Sperber have recently argued that the capacity for epistemic vigilance enables people to filter misinformation, based not only on epistemic but also on affective knowledge. Some of the cognitive mechanisms presupposed by epistemic vigilance are targeted at the source of information, others at its content. Within the framework of the argumentative theory of reasoning, we propose a cognitive account of seduction able to distinguish it from deception, by focusing on the affective component of epistemic vigilance. We argue that in seduction emotions, far from being totally automatic, unconscious and obliged, contribute to the appreciation of both the source and content of information. Diversely from deception, seduction presupposes a positive role of emotions which induces a creative style of argumentation

FIRST REPORT OF STREBLOCERA MACROSCAPUS (RUTHE) (HYMENOPTERA BRACONIDAE EUPHORINAE) IN ITALY

A female of Streblocera macroscapus (Ruthe) (Hymenoptera Braconidae Euphorinae) was captured on a yellow sticky trap during a monitoring survey aimed at studying insect biodiversity in Viareggio district (Lucca, Italy). This is the first report of this species in Italy. Biological information on S. macroscapus and its particular ecological niche are reviewed, and images of the specimen are presented. The importance of urban gardens and their proximity to the surrounding wild areas is also considered

Descriptions of the Adult Genitalia and Immatures of the Asian Planthopper Ricania speculum Recently Introduced to Italy (Hemiptera: Fulgoroidea: Ricaniidae).

The ricaniid planthopper Ricania speculum (Walker) (Hemiptera: Fulgoroidea) was recently introduced to Italy, apparently from southeast Asia. This species has the potential to become a significant agricultural pest, as it feeds on > 60 species of plants, some of which are of economic importance. Here we describe and illustrate the adult male and female genitalia and the first- through fifth-instar nymphs