Search results for "Pulse"

Intramolecular proton transfer boosts water oxidation catalyzed by a Ru complex

2015

We introduce a new family of complexes with the general formula [Run(tda)(py)2]m+ (n = 2, m = 0, 1; n = 3, m = 1, 2+; n = 4, m = 2, 32+), with tda2– being [2,2′:6′,2″-terpyridine]-6,6″-dicarboxylate, including complex [RuIV(OH)(tda-κ-N3O)(py)2]+, 4H+, which we find to be an impressive water oxidation catalyst, formed by hydroxo coordination to 32+ under basic conditions. The complexes are synthesized, isolated, and thoroughly characterized by analytical, spectroscopic (UV–vis, nuclear magnetic resonance, electron paramagnetic resonance), computational, and electrochemical techniques (cyclic voltammetry, differential pulse voltammetry, coulometry), …

High performance hardware correlation coefficient assessment using programmable logic for ECG signals

2003

Abstract Correlation coefficient is frequently used to obtain cardiac rhythm by peak estimation and appreciate differences in the signal compared to a pattern. This work focuses on the description of a real-time correlation assessment procedure. Applied to electrocardiogram (ECG) signals, a new correlation value is obtained every new sample and pulse detection information is provided. The ECG pattern is internally stored and can be changed when desired. This procedure is useful in Systems on Chip implementation and can be applied to design compact ECG monitoring systems consisting on a system on chip where programmable logic offloads the main processor. A Xilinx FPGA device has been used fo…

Contribution to the study of physico-chemical properties of surfaces modified by last treatment : application to the enhancement of localized corrosi…

2011

Metallic materials are more and more used in severe conditions with particularly strong request for improving their behavior in aggressive environment and especially over long periods. The objective of this PhD work is to estimate the potentiality of a laser surface melting treatment on the improvement of the stainless steel 304L corrosion resistance, surface treatments by laser can be revisited on the basis of a recent change in the laser technology. In the frame of this work, a nano-pulsed laser fiber was chosen : it allows the treated surface to be melted for few microns in depth, followed by an ultra-fast solidification occuring with cooling rates up to 1011 K/s. The combination of thes…

Tracking the time-evolution of the electron distribution function in Copper by femtosecond broadband optical spectroscopy

2019

Multitemperature models are nowadays often used to quantify the ultrafast electron-phonon (boson) relaxations and coupling strengths in advanced quantum solids. To test their applicability and limitations, we perform systematic studies of carrier relaxation dynamics in copper, a prototype system for which the two-temperature model (TTM) was initially considered. Using broadband time-resolved optical spectroscopy, we study the time evolution of the electron distribution function, $f(E)$, over a large range of excitation densities. Following intraband optical excitation, $f(E)$ is found to be athermal over several 100 fs, with a substantial part of the absorbed energy already being transferre…

Zero Ripple Current with Coupled Inductors in Continuous Conduction Mode under PWM Signals

2020

This article presents a generalized analysis to explain current ripple of an $m$ windings coupled inductor with a given coupling factor $k_{ij}$ for each pair of windings and then studies more in detail its use in the continuous conduction mode and with pulsewidth modulated signals. To determine the current ripple, a generalized expression of the equivalent inductance of each winding is calculated, including the influence of voltage unbalance. In the ideal case, the equivalent inductance shows that the current ripple can only become $m$ times smaller than that with uncoupled inductors. But in the unbalanced case, some divergences of the equivalent inductance appear that are responsible for …

Nonlinear pulse deceleration using photorefractive four-wave mixing

2009

We investigate the possibilities of the backward four-wave coupling based on the nonlocal photorefractive response for the nonlinear deceleration of light pulses. The presence of an additional external variable parameter—the pump intensity ratio—allows to improve the output characteristics of the decelerated pulses compared to those typical of the two-wave coupling. In particular, large delay times of the output pulses can be achieved without their strong amplification. This positive distinctive feature of the pulse deceleration occurs far from threshold of the mirrorless optical oscillation.

The TES-based cryogenic anticoincidence detector for IXO: First results from large area prototypes

2010

The technique which combines high resolution spectroscopy with imaging capability is a powerful tool to extract fundamental information in X-ray Astrophysics and Cosmology. TES (Transition Edge Sensors)-based microcalorimeters match at best the requirements for doing fine spectroscopy and imaging of both bright (high count rate) and faint (poor signal-to-noise ratio) sources. For this reason they are considered among the most promising detectors for the next high energy space missions and are being developed for use on the focal plane of the IXO (International X-ray Observatory) mission. In order to achieve the required signal-to-noise ratio for faint or diffuse sources it is necessary to r…

Formation of luminescence centres under excitation with electron beams in PbWO 4 and ZnWO 4 crystals

2005

The leading edge of intrinsic luminescence pulse in PbWO 4 and ZnWO 4 single crystals is studied. The rise of luminescence intensity is observed after excitation with electron beam pulse. The luminescence rise is shown tobe a result of luminescence center formation via electron-hole recombination within spatially correlated pairs. An electron of a geminate electron-hole pair of PbWO 4 crystal self-traps and stimulates self-trapping of a hole at a close distance. In the ZnWO 4 crystal a hole of a geminate electron-hole pair self-traps and stimulates self-trapping of the electron producing a W 5 + center at a short distance. The rise-time of luminescence depends on spatial separation of recom…

Historical and systematical aspects of indirect translation in the de Gruyter Handbuch Übersetzung – HSK. 26.1–3: insight and impulse to further rese…

2014

Analog Photonic Fractional Signal Processing

2018

Fil: Cuadrado Laborde, Christian. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Cuadrado Laborde, Christian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Cuadrado Laborde, Christian. Pontificia Universidad Católica Argentina. Facultad de Química e Ingeniería del Rosario; Argentina Fil: Poveda-Wong, Luis. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Carrascosa, Antonio. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales ; España Fil: Diez, Antonio. Universidad de Valencia. Instituto Universitario de Ciencia de los Materiales; España Fil: Cruz, Jo…