582 research outputs found
Using generalized PowerFlux methods to estimate the parameters of periodic gravitational waves
We investigate methods to estimate the parameters of the gravitational-wave
signal from a spinning neutron star using Fourier transformed segments of the
strain response from an interferometric detector. Estimating the parameters
from the power, we find generalizations of the PowerFlux method. Using
simulated elliptically polarized signals injected into Gaussian noise, we apply
the generalized methods to estimate the squared amplitudes of the plus and
cross polarizations (and, in the most general case, the polarization angle),
and test the relative detection efficiencies of the various methods.Comment: 8 pages, presented at Amalid7, Sydney, Australia (July 2007), fixed
minor typos and clarified discussion to match published CQG version; updated
reference
Polarography of Te (IV) Anions in Neutral Solutions in Presence of 2,2'- Dipyridyl and Fe(dipy)3 2+ - Complexes
The electroreduction of Te (IV) ions in neutral non-buffer solutions containing 2,2'-dipyridyl (4⋅10-5- 4⋅10-3 M) or tris-dipyridyl iron (II) complexes is studied by the polarographic method. NaF (0.01-0.5 M) or NaNO3 (0.1-1 M) are used as supporting electrolytes. The mechanism of electrochemical reactions of Te (IV) anions on mercury electrodes in the presence of the additives is discussed. The electroreduction of Te (IV) anions is shown to proceed through electron transfer and proton addition. The obtained results point to a considerable influence of electric double layer structure on electrochemical reactions of Te (IV) ions in the presence of inorganic and specifically adsorbed organic compounds in the electrolyte. It is shown, that 2,2'-dipyridyl does not form complexes with Te (IV) anions. Having been adsorbed on the surface of mercury electrode, 2,2'-dipyridyl complexes increase negative Ψ'-potential that results in a shift of Te (IV) electroreduction wave to more negative potentials and decrease in the current of Te (IV) wave and peak at -1.19 V. It is shown that 2,2'-dipyridyl molecules at ε > 0, (ε – charge of an electrode) are adsorbed in plane orientation, and at ε < 0, plane or vertical. Vertically adsorbed molecules cause a significant decrease in the double layer capacitance. At negative potentials orientation of 2,2'-dipyridyl molecules changes from plane to vertical with the increasing 2,2'-dipyridyl concentration. This change of orientation results in a typical maximum capacitance emerging in the potential range of -0.7 to -1.2 V. It is shown that the supporting electrolyte, 2,2'-dipyridyl and Fe(dipy)32+  have influence on the electroreduction of Te (IV) anions in neutral non-buffer solutions through a change in the Ψ'-potential of mercury electrode
The Principal Element of a Frobenius Lie Algebra
We introduce the notion of the \textit{principal element} of a Frobenius Lie
algebra \f. The principal element corresponds to a choice of F\in \f^* such
that non-degenerate. In many natural instances, the principal element
is shown to be semisimple, and when associated to \sl_n, its eigenvalues are
integers and are independent of . For certain ``small'' functionals , a
simple construction is given which readily yields the principal element. When
applied to the first maximal parabolic subalgebra of \sl_n, the principal
element coincides with semisimple element of the principal three-dimensional
subalgebra. We also show that Frobenius algebras are stable under deformation.Comment: 10 page
Investigation of antiparkinsonian activity of new imidazole-4,5-dicarboxylic acid derivatives on the experimental model of catalepsy
To study the antiparkinsonian activity of new ligands of the glutamate NMDA receptor complex -1,2-substituted imidazole-4,5-dicarboxylic acids - on an experimental model of catalepsy caused by haloperidol intraabdominal injections in rat
Reply to S Riehl and K Pustovoytov (Journal of Archaeological Science 33 (2006) 143-144)
We appreciate the interest of Simone Riehl and Konstantin Pustovoytov (hereafter R&P) in our publication and here we answer their critical remarks and questions. R&P criticise two aspects: (1) our interpretation of the pollen record from Kutuzhekovo Lake and (2) the information we derived from the St. Petersburg radiocarbon database. We discuss the questions and we show that these do not really affect our earlier conclusions.
First search for gravitational waves from the youngest known neutron star
We present a search for periodic gravitational waves from the neutron star in the supernova remnant Cassiopeia
A. The search coherently analyzes data in a 12 day interval taken from the fifth science run of the Laser
Interferometer Gravitational-Wave Observatory. It searches gravitational-wave frequencies from 100 to 300 Hz
and covers a wide range of first and second frequency derivatives appropriate for the age of the remnant and
for different spin-down mechanisms. No gravitational-wave signal was detected. Within the range of search
frequencies, we set 95% confidence upper limits of (0.7–1.2) × 10^(−24) on the intrinsic gravitational-wave
strain, (0.4–4) × 10^(−4) on the equatorial ellipticity of the neutron star, and 0.005–0.14 on the amplitude of
r-mode oscillations of the neutron star. These direct upper limits beat indirect limits derived from energy
conservation and enter the range of theoretical predictions involving crystalline exotic matter or runaway r-modes.
This paper is also the first gravitational-wave search to present upper limits on the r-mode amplitude
Searching for gravitational waves from known pulsars
We present upper limits on the amplitude of gravitational waves from 28
isolated pulsars using data from the second science run of LIGO. The results
are also expressed as a constraint on the pulsars' equatorial ellipticities. We
discuss a new way of presenting such ellipticity upper limits that takes
account of the uncertainties of the pulsar moment of inertia. We also extend
our previous method to search for known pulsars in binary systems, of which
there are about 80 in the sensitive frequency range of LIGO and GEO 600.Comment: Accepted by CQG for the proceeding of GWDAW9, 7 pages, 2 figure
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