Search results for "harmonic"

Three-Dimensional Numerical Model of an H2+ Ion in Intense Laser Fields

2010

HHG by a 3D-H2+ molecular ion

2009

Study of the effects of nuclear motion on High Harmonic Generation in simple molecules

2009

The Emergence of Chaos in Quantum Mechanics

2020

Nonlinearity in Quantum Mechanics may have extrinsic or intrinsic origins and is a liable route to a chaotic behaviour that can be of difficult observations. In this paper, we propose two forms of nonlinear Hamiltonian, which explicitly depend upon the phase of the wave function and produce chaotic behaviour. To speed up the slow manifestation of chaotic effects, a resonant laser field assisting the time evolution of the systems causes cumulative effects that might be revealed, at least in principle. The nonlinear Schr&ouml

Backward second-harmonic generation of near infrared picosecond pulses

2014

We report on backward second-harmonic generation using picosecond laser pulses in congruent lithium niobate with 3.2 µm periodic poling. By tuning both the pump wavelength and the sample temperature, we observed three resonant peaks in the range 1530-1730 nm, corresponding to 16th, 17th and 18th quasi-phase-matching orders, respectively. A maximum conversion efficiency of 0.475% was achieved at the 16th order with a 10 kW peak pump power. The latter is the highest conversion reported in bulk to date, for the backward configuration, with an improvement greater than 50% with respect to those previously achieved with nanosecond pulses for the same order of resonance.

Metodi Automatici per la Compensazione della Distorsione in Immagini di Risonanza Magnetica

ARC FAULT DETECTION EQUIPMENT AND METHOD USING LOW FREQUENCY HARMONIC CURRENT ANALYSIS

2012

An arc fault detection circuit includes a current sensing circuit coupled to a line conductor carrying a current. The current sensing circuit operates to sense current and output data indicative of the sensed current. A processing circuit implements a frequency transform algorithm to transform the output data to frequency data in a low frequency range and with a high spectral resolution where a minimum short time observation window is concerned. The processing circuit identifies an arc fault condition on the line conductor by identifying differences in said frequency data between at least two subsequent observation windows and identifying characteristics which exceed thresholds.

A single-point approach based on IEEE 1459-2000 for the identification of prevailing harmonic sources detection in distorted three phase power systems

2009

This paper deals with a novel single-point strategy for the detection of prevailing harmonic sources downstream or upstream the metering section in three-phase power systems. It is an enhancement of a previous strategy, already developed by the authors and it is based on the comparison of three non-active power quantities which are based on the IEEE Std. 1459-2000 approach. The method does not require any spectral analysis of voltages and currents because it is based only on the separation of the fundamental components from the harmonic content of voltage and current. In the paper, the effectiveness of the strategy is investigated by means of simulation tests which were carried out on a IEE…

USE OF HARMONIC SCALPEL FOR BRACHIO-BASILIC VEIN TRANSPOSITION IN AUTOGENOUS PROXIMAL ARTERIOVENOUS FISTULA

2009

Objectives: This study evaluates the effectiveness and helpfulness of ultrasonic surgical device for atraumatic surgical dissection and hemostasis in brachio-basilic vein transposition. Since prosthetic grafts have been reached poor results and high costs, the primary use of autogenous AVF is recommended. Materials and Methods: From March 2004 to March 2009 67 cases (61 F ; 6 M; mean age 52 years) of brachio-basilic arteriovenous fistulae (BBAVF) were fashioned; in second stage, after vein maturation (about 30 days), we performed a superficial transposition of arterialized basilic vein by harmonic scalpel (UltracisionTM).. Results : On 67 cases of transposition of BBAVF 2 cases failed after…

Analysis of Stray Flux Spectral Components in Induction Machines under Rotor Bar Breakages at Various Locations

2018

Induction machines under rotor electrical faults have been subjected to intensive research over the years. It is not only the nature of the fault that makes it important to study, but also the differences observed regarding this fault's effect on the motor's conditions. One of these conditions is the rotor bar breakages at non adjacent positions, which has drawn the attention of researchers due to the false negative diagnostic alarms that may be caused. In this paper, a novel approach is presented aiming to reliably detect this type of fault condition. The proposed method is based on the analysis of specific subcomponents of the stray flux over time. The analysis is implemented on an indust…