Search results for "Potential"
showing 10 items of 3348 documents
A novel linear-non-linear digital control for DC/DC converters
2006
In this paper, a digitally controlled multi-module DC-DC converter with fast transient response, based on a linear-non-linear control is presented. The proposed digital control improves the stability of the system, cuts off the effects of limit-cycle and reduces the recovery time, by making the "effective" bandwidth of the system independent of the bandwidth of the linear control loop and limits, at the same time, output voltage variations. The novel digital control is AVP-compatible and halves the recovery time. Preliminary hardware tests on a single phase step-down converter are reported. The experimental results match simulation ones, obtained by modelling system with Matlab/Aldec mixed …
Deregulated Electric Energy Price Forecasting in NordPool Market using Regression Techniques
2019
Deregulated electricity market day-ahead electrical energy price forecasting is important. It is influenced by external parameters and it is a complicated function. In this work two neighboring regions in the NordPool market are analyzed to provide day-ahead electrical price forecasting using regression techniques. The characteristics of the NordPool market trading behavior leads to unanticipated price peaks at daily, weekly and annual level. The considered two Nordic regions have different energy generation sources (e.g Norway has controllable hydro power, Denmark has non-controllable wind-power) therefore day-ahead electrical energy price forecasting in deregulated market for these two ne…
Fundamentals of photoelectrocatalysis
2022
Photoelectrocatalysis combines heterogeneous photocatalysis and electrocatalysis principles for numerous processes including the degradation of harmful compounds, the generation of H2 and O2 from water splitting, the reduction of CO2 or the photoelectrocatalytic synthesis of valuable organic molecules otherwise difficult to be synthetized with classical approaches. The recent progress of photoelectrocatalysis is heavily related to the development of materials, especially in 2D and nano materials. Highly ordered nanomaterials such as graphene, nanotubes, nanowires, etc. are gaining more attention due to their high surface area and excellent conductivity. Other challenges are the development …
Data-driven analysis of simultaneous EEG/fMRI reveals neurophysiological phenotypes of impulse control
2016
Response inhibition is the ability to suppress inadequate but prepotent or ongoing response tendencies. A fronto-striatal network is involved in these processes. Between-subject differences in the intra-individual variability have been suggested to constitute a key to pathological processes underlying impulse control disorders. Single-trial EEG/fMRI analysis allows to increase sensitivity for inter-individual differences by incorporating intra-individual variability. Thirty-eight healthy subjects performed a visual Go/Nogo task during simultaneous EEG/fMRI. Of 38 healthy subjects, 21 subjects reliably showed Nogo-related ICs (Nogo-IC-positive) while 17 subjects (Nogo-IC-negative) did not. C…
Interaction of ionic compounds with multilamellar liposomes. An electrokinetic model
1998
Abstract We have proposed a theoretical model of interaction of ionic compounds (ionic adsorbate or ionic drugs), with multilamellar-liposomes, by means of their electrokinetic property variation with the ionic compound concentration. In this work, we show the complete development of the model proposed. Its theoretical results have been analysed to study the influence on the zeta-potential value of the following: number of membranes, size, shear-plane situation, critical concentration of formation (ccf), and the ionic compound concentration which annuls the zeta-potential value of the multilamellar-liposomes formed.
C-S-H/solution interface: Experimental and Monte Carlo studies
2010
International audience; The surface charge density of C-S-H particles appears to be one of the key parameters for predicting the cohesion strength, understanding the ion retention, the pollutant leakage, and admixture adsorption in hydrated cement pastes. This paper presents a Monte Carlo simulation of the surface-ions interactions that permits the prediction of surface charge density (σ), electrokinetic potential (ζ) and ions adsorption of mineral surfaces in equilibrium with a given electrolyte solution. Simulated results are compared to experimental data obtained by titration, electrokinetic potential measurements and ions uptake in the case of C-S-H suspensions. An excellent agreement i…
Biorthonormal-basis method for the vector description of optical-fiber modes
1998
This paper gives the theoretical basis for the development of real vector modal methods to describe optical-fiber modes. To this end, the vector wave equations, which determine the electromagnetic fields, are written in terms of a pair of linear, nonself-adjoint operators, whose eigenvectors satisfy biorthogonality relations. The key of our method is to obtain a matrix representation of the vector wave equations in a basis that is defined by the modes of an auxiliary system. Our proposed technique can be applied to fibers with any profile, even those with a complex refractive index. An example is discussed to illustrate our approach.
Exactly solvable model of two three-dimensional harmonic oscillators interacting with the quantum electromagnetic field: The far-zone Casimir-Polder …
2005
We consider two three-dimensional isotropic harmonic oscillators interacting with the quantum electromagnetic field in the Coulomb gauge and within dipole approximation. Using a Bogoliubov-like transformation, we can obtain transformed operators such that the Hamiltonian of the system, when expressed in terms of these operators, assumes a diagonal form. We are also able to obtain an expression for the energy shift of the ground state, which is valid at all orders in the coupling constant. From this energy shift the nonperturbative Casimir-Polder potential energy between the two oscillators can be obtained. When approximated to the fourth order in the electric charge, the well-known expressi…
The electromagnetic and Proca fields revisited: A unified quantization
1997
Quantizing the electromagnetic field with a group formalism faces the difficulty of how to turn the traditional gauge transformation of the vector potential, Aμ(x) → Aμ(x) + ∂μφ(x), into a group law. In this paper, it is shown that the problem can be solved by looking at gauge transformations in a slightly different manner which, in addition, does not require introducing any BRST-like parameter. This gauge transformation does not appear explicitly in the group law of the symmetry but rather as the trajectories associated with generalized equations of motion generated by vector fields with null Noether invariants. In the new approach the parameters of the local group, U(1)(x, t), acquire dyn…
Noncoaxial Inductance Calculations Without the Vector Potential for Axisymmetric Coils and Planar Coils
2008
This paper presents an exact method for calculating the mutual inductance between a general axisymmetric coil and a second planar coil consisting of either a disk coil or a planar loop of essentially arbitrary shape. The approach is based directly on the magnetic field rather than the vector potential . The paper gives detailed results for two circular loops, a circular loop and an elliptic loop, and a circular loop and an annular disk coil. The method can be extended to cover the cases where all these loops and coils are extruded in the axial direction to give the corresponding solenoids. The method is also applicable to calculations for nuclear radiation detectors.