Search results for "Quantitative"

Key Electoral Institutions and Rules Influencing Proportionality and Partisan Bias in Spanish Politics

2021

The current paper focuses on the Spanish electoral rules governing political competition for the central “Congreso de los Diputados”. It is well-documented that the system as a whole has traditionally favoured one or the other of the two main political parties (PP and PSOE) at the expense of proportionality and the remaining political parties. This paper focuses on some key Spanish electoral rules and investigates how much the observed biases could be altered by introducing some alternative rules taken from the Swedish electoral system, ceteris paribus. Measures of disproportionality are made through the Loosemore–Hanby index and the Gallagher index. The electoral raw data used for our esti…

A dq axis theory of the magnetic, thermal, and mechanical properties of Curie motor

2011

A dq axis theory of a thermomagnetic Curie motor is presented. This theory allows one to estimate the performances of a Curie motor from its geometrical, magnetic, and thermal properties. The proposed approach shows that the thermomagnetic Curie motor is equivalent from a magnetic point of view to a dc electric machine. The physical meaning of the parameters used in the dq theory of Curie motor is explicated. The theory is validated by using experimental data.

Dynamics of Magnetotactic Bacteria in a Rotating Magnetic Field

2007

The dynamics of the motile magnetotactic bacterium Magnetospirillum gryphiswaldense in a rotating magnetic field is investigated experimentally and analyzed by a theoretical model. These elongated bacteria are propelled by single flagella at each bacterial end and contain a magnetic filament formed by a linear assembly of approximately 40 ferromagnetic nanoparticles. The movements of the bacteria in suspension are analyzed by consideration of the orientation of their magnetic dipoles in the field, the hydrodynamic resistance of the bacteria, and the propulsive force of the flagella. Several novel features found in experiments include a velocity reversal during motion in the rotating field a…

Understanding the regioselectivity in hetero Diels–Alder reactions. An ELF analysis of the reaction between nitrosoethylene and 1-vinylpyrrolidine

2013

[EN] The regioselectivity in the hetero Diels-Alder reaction between nitrosoethylene 1 and 1-vinylpyrrolidine 2 has been studied by a comparative ELF bonding analysis along the IRC of the endo/ortho and endo/meta regioisomeric channels at the B3LYP/6-31G*. level. Along the most favorable endo/ortho regioisomeric channel, the C-C sigma bond is first formed by coupling of two pseudoradical centers located at the most electrophilic carbon of 1 and the most nucleophilic center of 2. Formation of these relevant pseudoradical centers, which depend on the total charge transfer process along the polar reaction, and not on the approach mode of each reagent, is well characterized by analysis of the a…

Oxygen K-shell spectroscopy of isolated progressively solvated peptide

2020

Gas-phase near-edge X-ray-absorption fine structure (NEXAFS) action spectroscopy around the oxygen K-edge and mass spectrometry were employed to probe isolated substance P (SP) molecular ions, both bare and progressively solvated with 4 and 11 water molecules. Detailed mass spectra of bare and hydrated precursors are presented for the resonant photon energy of 532 eV that corresponds to O1s --> pi(amide)* core excitation, triggering resonant Auger decay and fragmentation from the ionized radical molecular system. The fragmentation pattern of doubly protonated SP hydrated with 4 water molecules clearly shows a series of abundant doubly charged backbone fragments, as well as triply charged pr…

Supermolecular control of charge transfer in dye-sensitized nanocrystalline TiO2 films: towards a quantitative structure-function relationship.

2005

T-wave alternans analysis improvement by means of curve alignment prior to distance calculation.

2007

Tracking of repolarization instabilities in the ECG, such as T-wave alternans (TWA), has become a popular non-invasive method to assess the vulnerability to malignant arrhythmic events. These instabilities are usually characterized by small amplitude changes and their measurement is difficult due to the presence of noise and artifacts. Several methods have been recently proposed to address this problem. Most of them are based on amplitude analysis of beat-to-beat alternation of the T wave. This paper describes a preprocessing stage intended to be used prior to amplitude analysis and aimed at improving the alignment between consecutive T waves. This increases the accuracy of the difference c…

Carbon nanotubes as electrodes for dielectrophoresis of DNA

2006

Dielectrophoresis can potentially be used as an efficient trapping tool in the fabrication of molecular devices. For nanoscale objects, however, the Brownian motion poses a challenge. We show that the use of carbon nanotube electrodes makes it possible to apply relatively low trapping voltages and still achieve high enough field gradients for trapping nanoscale objects, e.g., single molecules. We compare the efficiency and other characteristics of dielectrophoresis between carbon nanotube electrodes and lithographically fabricated metallic electrodes, in the case of trapping nanoscale DNA molecules. The results are analyzed using finite element method simulations and reveal information abou…

Monte Carlo simulation of DNA electrophoresis

1989

This paper describes an attempt to study the electrophoresis mobility of a DNA molecule in a gel by means of a Monte Carlo simulation. We find that the electrophoresis mobility mu can be well described by the empirical equation mu v kappa 1/N + kappa 2E2 with N being the number of monomers of the model chain and E being the applied field. For small E the data can merge into the linear response result mu = kappa 1/N. The paper also discusses necessary extensions of the present approach.

Theoretical and experimental study of the role of cell-cell dipole interaction in dielectrophoretic devices: application to polynomial electrodes

2013

BACKGROUND: We aimed to investigate the effect of cell-cell dipole interactions in the equilibrium distributions in dielectrophoretic devices. METHODS: We used a three dimensional coupled Monte Carlo-Poisson method to theoretically study the final distribution of a system of uncharged polarizable particles suspended in a static liquid medium under the action of an oscillating non-uniform electric field generated by polynomial electrodes. The simulated distributions have been compared with experimental ones observed in the case of MDA-MB-231 cells in the same operating conditions. RESULTS: The real and simulated distributions are consistent. In both cases the cells distribution near the elec…