Search results for "Electronics"
showing 10 items of 4340 documents
Observation of topological gravity-capillary waves in a water wave crystal
2019
The discovery of topological phases of matter, initially driven by theoretical advances in quantum condensed matter physics, has been recently extended to classical wave systems, reaching out to a wealth of novel potential applications in signal manipulation and energy concentration. Despite the fact that many realistic wave media (metals at optical frequencies, polymers at ultrasonic frequencies) are inherently dispersive, topological wave transport in photonic and phononic crystals has so far been limited to ideal situations and proof-of-concept experiments involving dispersionless media. Here, we report the first experimental demonstration of topological edge states in a classical water …
Inverse estimation of terminal connections in the cardiac conduction system
2017
Modeling the cardiac conduction system is a challenging problem in the context of computational cardiac electrophysiology. Its ventricular section, the Purkinje system, is responsible for triggering tissue electrical activation at discrete terminal locations, which subsequently spreads throughout the ventricles. In this paper, we present an algorithm that is capable of estimating the location of the Purkinje system triggering points from a set of random measurements on tissue. We present the properties and the performance of the algorithm under controlled synthetic scenarios. Results show that the method is capable of locating most of the triggering points in scenarios with a fair ratio bet…
Surface-plasmon hopping along coupled coplanar cavities
2007
International audience; We report on surface-plasmon propagation along coupled coplanar cavities periodically distributed in an otherwise unperturbed plasmonic crystal. We show that the dispersion of particular Bloch modes can exhibit multiple energy gaps that can be adjusted by choosing the cavity size. For resonant sizes, the composite crystals composed of juxtaposed cavities can support plasmon modes at frequencies within the gap of the unperturbed grating. In this case, we demonstrate that the surface-plasmon propagation relies on a hopping mechanism.
Simulations of a Graphene Nanoflake as a Nanovector To Improve ZnPc Phototherapy Toxicity: From Vacuum to Cell Membrane
2017
International audience; We propose a new approach to improving photodynamic therapy (PDT) by transporting zinc phthalocyanine (ZnPc) in biological systems via a graphene nanoflake, to increase its targeting. Indeed, by means of time-dependent density functional theory simulations, we show that the ZnPc molecule in interaction with a graphene nanoflake preserves its optical properties not only in a vacuum but also in water. Moreover, molecular dynamic simulations demonstrate that the graphene nanoflake/ZnPc association, as a carrier, permits one to stabilize the ZnPc/graphene nanoflake system on the cellular membrane, which was not possible when using ZnPc alone. We finally conclude that the…
On the Interaction between 1D Materials and Living Cells
2020
One-dimensional (1D) materials allow for cutting-edge applications in biology, such as single-cell bioelectronics investigations, stimulation of the cellular membrane or the cytosol, cellular capture, tissue regeneration, antibacterial action, traction force investigation, and cellular lysis among others. The extraordinary development of this research field in the last ten years has been promoted by the possibility to engineer new classes of biointerfaces that integrate 1D materials as tools to trigger reconfigurable stimuli/probes at the sub-cellular resolution, mimicking the in vivo protein fibres organization of the extracellular matrix. After a brief overview of the theoretical models r…
Centrifuge tests on strip footings on sand with a weak layer
2017
Tests on small-scale physical models of a strip footing resting on a dense sand bed containing a thin horizontal weak soil layer were carried out at normal gravity (1 g ). The results, reported in a companion paper, point out that the weak layer plays an important role in the failure mechanism and the ultimate bearing capacity of the footing if it falls within the ground volume relevant to the behaviour of the sand–footing system. The same problem was also investigated by means of centrifuge tests on reduced-scale models at 25 g and 40 g . The results of these tests, reported and discussed in this paper, confirm that failure mechanisms are governed substantially by the presence of the weak…
Aluminium nitrate ceramics: a potential UV dosemeter material.
2002
The ceramic material AlN-Y 2 O 3 is proposed as a potential ultraviolet radiation (UVR) dosemeter using optically stimulated luminescence (OSL) and thermally stimulated luminescence (TL). Experimental studies have shown that AlN ceramics exhibit attractive characteristics suitable for practical UV dosimetry applications. The features are: (1) the spectral sensitivity covers the 200-350 nm range, in the UV-B region it is similar to that of human skin; (2) the angular dependence of the incident radiation follows the cosine law; (3) high yields of both UVR-induced OSL and TL signals compared to those of Al 2 O 3 :C; and (4) a large dynamic range TL signal (5 orders of magnitude). Although ther…
On localization of moving objects in the visual system of cats.
1980
In cortical areas direction-specific receptive fields occur systematically. Direction specifity is based on unsymmetric coupling of neurons. Such a coupling allows an exact localization of moved stimuli. For this task, the asymmetry in the time domain is compensated for by a spatial asymmetry.
Platinum-doped CeO2 thin film catalysts prepared by magnetron sputtering.
2010
The interaction of Pt with CeO(2) layers was investigated by using photoelectron spectroscopy. The 30 nm thick Pt doped CeO(2) layers were deposited simultaneously by rf-magnetron sputtering on a Si(001) substrate, multiwall carbon nanotubes (CNTs) supported by a carbon diffusion layer of a polymer membrane fuel cell and on CNTs grown on the silicon wafer by the CVD technique. The synchrotron radiation X-ray photoelectron spectra showed the formation of cerium oxide with completely ionized Pt(2+,4+) species, and with the Pt(2+)/Pt(4+) ratio strongly dependent on the substrate. The TEM and XRD study showed the Pt(2+)/Pt(4+) ratio is dependent on the film structure.
Growth of nano-porous Pt-doped cerium oxide thin films on glassy carbon substrate
2013
Abstract Glassy carbon (GC) substrates were treated by the oxygen plasma over several periods of time. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) study showed the dramatic influence of oxygen plasma on the morphology of glassy carbon. The treatment leads to the formation of nanostructured surface, which consists of well separated rod-like nanostructures oriented perpendicularly to the substrate surface. The surface roughness was found to increase with increasing treatment time. By using magnetron co-sputtering of platinum and cerium oxide we can prepare oxide layers continuously doped with Pt atoms during the growth. This tec…