Electrodeposition of a Au-Dy 2 O 3 Composite Solid Oxide Fuel Cell Catalyst from Eutectic Urea/Choline Chloride Ionic Liquid

In this research we have fabricated and tested Au/Dy2O3 composites for applications as Solid Oxide Fuel Cell (SOFC) electrocatalysts. The material was obtained by a process involving electrodeposition of a Au-Dy alloy from a urea/choline chloride ionic liquid electrolyte, followed by selective oxidation of Dy to Dy2O3 in air at high temperature. The electrochemical kinetics of the electrodeposition bath were studied by cyclic voltammetry, whence optimal electrodeposition conditions were identified. The heat-treated material was characterised from the morphological (scanning electron microscopy), compositional (X-ray fluorescence spectroscopy) and structural (X-ray diffractometry) points of view. The electrocatalytic activity towards H2 oxidation and O2 reduction was tested at 650 °C by electrochemical impedance spectrometry. Our composite electrodes exhibit an anodic activity that compares favourably with the only literature result available at the time of this writing for Dy2O3 and an even better cathodic performance

Convolutors on Sω(RN)\mathcal{S}_\omega(\mathbb{R}^N)

In this paper we continue the study of the spaces $\mathcal{O}_{M,\omega}(\mathbb{R}^N)$ and $\mathcal{O}_{C,\omega}(\mathbb{R}^N)$ undertaken in [1]. We determine new representations of such spaces and we give some structure theorems for their dual spaces. Furthermore, we show that $\mathcal{O}'_{C,\omega}(\mathbb{R}^N)$ is the space of convolutors of the space $\mathcal{S}_\omega(\mathbb{R}^N)$ of the $\omega$-ultradifferentiable rapidly decreasing functions of Beurling type (in the sense of Braun, Meise and Taylor) and of its dual space $\mathcal{S}'_\omega(\mathbb{R}^N)$. We also establish that the Fourier transform is an isomorphism from $\mathcal{O}'_{C,\omega}(\mathbb{R}^N)$ onto $\mathcal{O}_{M,\omega}(\mathbb{R}^N)$. In particular, we prove that this isomorphism is topological when the former space is endowed with the strong operator lc-topology induced by $\mathcal{L}_b(\mathcal{S}_\omega(\mathbb{R}^N))$ and the last space is endowed with its natural lc-topology.Comment: arXiv admin note: text overlap with arXiv:2011.0396

Topological Properties of Weighted Composition Operators in Sequence Spaces

For fixed sequences u=(ui)i∈N,φ=(φi)i∈N , we consider the weighted composition operator Wu,φ with symbols u, φ defined by x=(xi)i∈N↦u(x∘φ)=(uixφi)i∈N . We characterize the continuity and the compactness of the operator Wu,φ when it acts on the weighted Banach spaces lp(v) , 1 ≤ p≤ ∞ , and c(v) , with v=(vi)i∈N a weight sequence on N . We extend these results to the case in which the operator Wu,φ acts on sequence (LF)-spaces of type lp(V) and on sequence (PLB)-spaces of type ap(V) , with p∈ [1 , ∞] ∪ { 0 } and V a system of weights on N . We also characterize other topological properties of Wu,φ acting on lp(V) and on ap(V) , such as boundedness, reflexivity and to being Montel.

Sustainable Materials from Fish Industry Waste for Electrochemical Energy Systems

Fish industry waste is attracting growing interest for the production of environmentally friendly materials for several different applications, due to the potential for reduced environmental impact and increased socioeconomic benefits. Recently, the application of fish industry waste for the synthesis of value-added materials and energy storage systems represents a feasible route to strengthen the overall sustainability of energy storage product lines. This review focused on an in-depth outlook on the advances in fish byproduct-derived materials for energy storage devices, including lithium-ion batteries (LIBs), sodium-ion (NIBs) batteries, lithium-sulfur batteries (LSBs), supercapacitors and protein batteries. For each of these, the latest applications were presented together with approaches to improve the electrochemical performance of the obtained materials. By analyzing the recent literature on this topic, this review aimed to contribute to further advances in the sustainability of energy storage devices

Mutual estimates of time-frequency representations and uncertainty principles

In this paper we give different estimates between Lebesgue norms of quadratic time-frequency representations. We show that, in some cases, it is not possible to have such bounds in classical $L^p$ spaces, but the Lebesgue norm needs to be suitably weighted. This leads to consider weights of polynomial type, and, more generally, of ultradifferentiable type, and this, in turn, gives rise to use as functional setting the ultradifferentiable classes. As applications of such estimates we deduce uncertainty principles both of Donoho-Stark type and of local type for representations

Finite-element modeling of neuromodulation via controlled delivery of potassium ions using conductive polymer-coated microelectrodes

: Objective. The controlled delivery of potassium is an interesting neuromodulation modality, being potassium ions involved in shaping neuron excitability, synaptic transmission, network synchronization, and playing a key role in pathological conditions like epilepsy and spreading depression. Despite many successful examples of pre-clinical devices able to influence the extracellular potassium concentration, computational frameworks capturing the corresponding impact on neuronal activity are still missing.Approach. We present a finite-element model describing a PEDOT:PSS-coated microelectrode (herein, simplyionic actuator) able to release potassium and thus modulate the activity of a cortical neuron in anin-vitro-like setting. The dynamics of ions in the ionic actuator, the neural membrane, and the cellular fluids are solved self-consistently.Main results. We showcase the capability of the model to describe on a physical basis the modulation of the intrinsic excitability of the cell and of the synaptic transmission following the electro-ionic stimulation produced by the actuator. We consider three case studies for the ionic actuator with different levels of selectivity to potassium: ideal selectivity, no selectivity, and selectivity achieved by embedding ionophores in the polymer.Significance. This work is the first step toward a comprehensive computational framework aimed to investigate novel neuromodulation devices targeting specific ionic species, as well as to optimize their design and performance, in terms of the induced modulation of neural activity

Multiphysics Finite-Element Modeling of the Neuron/Electrode Electrodiffusive Interaction

Understanding the biological-electrical transduction mechanisms is essential for reliable neural signal recording and feature extraction. As an alternative to state-of-the-art lumped-element circuit models, here we adopt a multiscale-multiphysics finite-element modeling framework. The model couples ion transport with the Hodgkin-Huxley model and the readout circuit, and is used to investigate a few relevant case studies. This approach is amenable to explore ion transport in the extracellular medium otherwise invisible to circuit model analysis

Advances in zinc-ion structural batteries

Electrical energy storage technologies have become a critical aspect of the whole clean energy system, which is fundamentally based on batteries. In the past decades, innovations in batteries changed the appearance of our lifestyle with portable devices. More recently, electrical vehicles have lead the mind toward a promising clean world without fossil fuels. However, minimizing the weight and/or volume of such batteries is the critical design driver, and in the last decade, the idea of moving electric energy accumulation inside structural parts has been proposed and named structural batteries, in which structural elements should also act as electric energy accumulators. The work on structural batteries to date has mostly involved Li-ion batteries due to their acceptable performance. However, the adoption of Li-ion batteries must face the limited availability of lithium on the earth and safety during their manufacturing and use. These issues encouraged researchers to seek alternative battery systems not having its drawbacks. Zn-ion structural batteries are a promising alternative to lithium-ion batteries in the post-lithium era. Zinc is one of the most abundant elements on the planet and can be found at low price. Zinc-based batteries also have the potential to use lower-cost production procedures because they do not require particular dry room conditions, which means the ability to operate in the air, allowing for large-scale assembly. Although Zn-ion batteries have numerous advantages, the development of Zn-ion structural batteries is still in its early stages (low Technology Readiness Level, TRL), and additional study is required. This review seeks to provide a concise description of current breakthroughs in materials and architecture design, as well as a critical assessment of the performance and limitations of the solutions adopted for zinc-based structural batteries. The difficulties in constructing Zn-ion structural batteries are discussed. This is the first complete examination of these batteries, and it provides an overview of the technology with the aim of promoting future structure battery chemistry research