Search results for "enginy"
showing 10 items of 181 documents
Noticias, que se proponen por Don Vicente Clavero de los Porcells ... Sobre si sera conveniente à la Real Hazienda reedificar el Pantano de Ontinien…
1689
Caplletra ornada al començament del text Sign.: A-L2 Reclams
Optimization of the KNN Supervised Classification Algorithm as a Support Tool for the Implantation of Deep Brain Stimulators in Patients with Parkins…
2019
Deep Brain Stimulation (DBS) of the Subthalamic Nuclei (STN) is the most used surgical treatment to improve motor skills in patients with Parkinson&rsquo
Tunable coupled surface acoustic cavities
2012
We demonstrate the electric tuning of the acoustic field in acoustic microcavities (MCs) defined by a periodic arrangement of metal stripes within a surface acoustic delay line on LiNbO3 substrate. Interferometric measurements show the enhancement of the acoustic field distribution within a single MC, the presence of a “bonding” and “anti-bonding” modes for two strongly coupled MCs, as well as the positive dispersion of the “mini-bands” formed by five coupled MCs. The frequency and amplitude of the resonances can be controlled by the potential applied to the metal stripes.
Experimental demonstration of bistable phase locking in a photorefractive oscillator
2012
We report experimental evidence of bistable phase locking in nonlinear optics, in particular, in a photorefractive oscillator emitting in few transverse modes. Bistable phase locking is a recently proposed method for converting a laserlike system, which is phase invariant, into a phase-bistable one by injecting a suitable spatially modulated monochromatic beam, resonant with the laser emission, into the optical cavity. We experimentally demonstrate that the emission on the fundamental TEM00 mode becomes phase bistable by injection of a beam with the shape of the TEM10 mode with appropriate frequency, in accordance with recent theoretical predictions [K. Staliunas et al., Phys. Rev. A 80, 02…
Soliton topology versus discrete symmetry in optical lattices
2005
We address the existence of vortex solitons supported by azimuthally modulated lattices and reveal how the global lattice discrete symmetry has fundamental implications on the possible topological charges of solitons. We set a general ``charge rule'' using group-theory techniques, which holds for all lattices belonging to a given symmetry group. Focusing in the case of Bessel lattices allows us to derive also a overall stability rule for the allowed vortex solitons.
Acousto-optical multiple interference switches
2007
The authors introduce an alternative approach for acousto-optical light control based on the interference of light propagating through several waveguides, each subjected to a periodic refractive index modulation induced by a surface acoustic wave. The feasibility of the concept is demonstrated by the realization of an optical switch for arbitrary time intervals with an on/off contrast ratio of 20.
Acousto-optical multiple interference devices
2008
We present a new concept for waveguide acousto-optical devices based on coupled MachZehnder interferometers driven by acoustic waves. These acousto-optical multiple interference devices use the periodic refractive index modulation induced by the acoustic wave to realize functionalities such as ON/OFF switching for an arbitrary time interval, as well as for efficient light modulation at high harmonics of the acoustic frequency and pulse shaping for, e.g., integrated Q-switches. We also discuss application of the concepts to light modulation by very high acoustic frequencies, where the acoustic wavelengths become much shorter than the optical ones.
Predicting acute termination and non-termination during ablation of human atrial fibrillation using quantitative indices
2022
Background: Termination of atrial fibrillation (AF), the most common arrhythmia in the United States, during catheter ablation is an attractive procedural endpoint, which has been associated with improved long-term outcome in some studies. It is not clear, however, whether it is possible to predict termination using clinical data. We developed and applied three quantitative indices in global multielectrode recordings of AF prior to ablation: average dominant frequency (ADF), spectral power index (SPI), and electrogram quality index (EQI).Methods: In N = 42 persistent AF patients (65 ± 9 years, 14% female) we collected unipolar electrograms from 64-pole baskets (Abbott, CA). We studied N = 1…
Overview: On the transport and transformation of pollutants in the outflow of major population centres - Observational data from the EMeRGe European …
2022
Megacities and other major population centres (MPCs) worldwide are major sources of air pollution, both locally as well as downwind. The overall assessment and prediction of the impact of MPC pollution on tropospheric chemistry are challenging. The present work provides an overview of the highlights of a major new contribution to the understanding of this issue based on the data and analysis of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) international project. EMeRGe focuses on atmospheric chemistry, dynamics, and transport of local and regional pollution originating in MPCs. Airborne measurements, taking advantage of …
Study of the correlation between columnar aerosol burden, suspended matter at ground and chemical components in a background European environment
2012
Although routinely monitored by ground based air quality networks, the particulate matter distribution could be eventually better described with remote sensing techniques. However, valid relationships between ground level and columnar ground based quantities should be known beforehand. In this study we have performed a comparison between particulate matter measurements at ground level at different cut sizes (10, 2.5 and 1.0 mm), and the aerosol optical depth obtained by means of a ground based sunphotometer during a multiinstrumental field campaign held in El Arenosillo (Huelva, Spain) from 28 June to 4 July 2006. All the PM fractions were very well correlated with AOD with correlation coef…