2,027 research outputs found
Fuzzy Inference System for VOLT/VAR control in distribution substations in isolated power systems
This paper presents a fuzzy inference system for voltage/reactive power
control in distribution substations. The purpose is go forward to automation
distribution and its implementation in isolated power systems where control
capabilities are limited and it is common using the same applications as in
continental power systems. This means that lot of functionalities do not apply
and computational burden generates high response times. A fuzzy controller,
with logic guidelines embedded based upon heuristic rules resulting from
operators at dispatch control center past experience, has been designed.
Working as an on-line tool, it has been tested under real conditions and it has
managed the operation during a whole day in a distribution substation. Within
the limits of control capabilities of the system, the controller maintained
successfully an acceptable voltage profile, power factor values over 0,98 and
it has ostensibly improved the performance given by an optimal power flow based
automation system
Highlights and Conclusions of the Chalonge 14th Paris Cosmology Colloquium 2010: `The Standard Model of the Universe: Theory and Observations'
The Chalonge 14th Paris Cosmology Colloquium was held on 22-24 July 2010 in
Paris Observatory on the Standard Model of the Universe: News from WMAP7,
BICEP, QUAD, SPT, AMI, ACT, Planck, QUIJOTE and Herschel; dark matter (DM)
searches and galactic observations; related theory and simulations. %aiming
synthesis, progress and clarification. P Biermann, D Boyanovsky, A Cooray, C
Destri, H de Vega, G Gilmore, S Gottlober, E Komatsu, S McGaugh, A Lasenby, R
Rebolo, P Salucci, N Sanchez and A Tikhonov present here their highlights of
the Colloquium. Inflection points emerged: LambdaWDM (Warm DM) emerges
impressively over LambdaCDM whose galactic scale problems are ever-increasing.
Summary and conclusions by H. J. de Vega, M. C. Falvella and N. G. Sanchez
stress among other points: (i) Primordial CMB gaussianity is confirmed.
Inflation effective theory predicts a tensor to scalar ratio 0.05-0.04 at
reach/border line of next CMB observations, early fast-roll inflation provides
lowest multipoles depression. SZ amplitudes are smaller than expected: CMB and
X-ray data agree but intracluster models need revision and relaxed/non-relaxed
clusters distinction. (ii) cosmic ray positron excess is explained naturally by
astrophysical processes, annihilating/decaying dark matter needs growing
tailoring. (iii) Cored (non cusped) DM halos and warm (keV scale mass) DM are
increasingly favored from theory and observations, naturally producing observed
small scale structures, wimps turn strongly disfavoured. LambdaWDM 1 keV
simulations well reproduce observations. Evidence that LambdaCDM does not work
at small scales is staggering. P Biermann presents his live minutes of the
Colloquium and concludes that a keV sterile neutrino is the most interesting DM
candidate. Photos of the Colloquium are included.Comment: 58 pages, 20 figures. Three contributions added: G. Gilmore, S.
Gottlober and E. Komats
Towards the Chalonge 17th Paris Cosmology Colloquium 2013: highlights and conclusions of the Chalonge 16th Paris Cosmology Colloquium 2012
LWDM (Warm Dark Matter) is progressing impressively.The galactic scale crisis
and decline of LCDM+baryons are staggering. The 16th Paris Chalonge Colloquium
2012 combined real cosmological/astrophysical data and hard theory predictive
approach in the LWDM Standard Model. News and reviews from
ACT,WMAP,SPT,QUIET,Planck,Herschel,JWST,UFFO,KATRIN and MARE experiments;
astrophysics, particle and nuclear physics WDM searches, galactic observations,
related theory and simulations, with the aim of synthesis and clarification.
Here highlights by P Biermann, C Burigana, C Conselice, A Cooray, H de Vega, C
Giunti & M Laveder, J Kormendi & K Freeman, E Ma, J Mather, L Page, G Smoot, N
Sanchez. Summary and conclusions by de Vega, Falvella and Sanchez. Data confirm
primordial CMB gaussianity. Effective (Ginsburg-Landau) Inflation theory
predicts r about 0.04-0.05, negligeable running of ns, the inflation energy
scale (GUT scale) and the set of CMB observables in agreement with the data.
WMAP9 and Planck measurements are compatible with one or two Majorana sterile
neutrinos in the eV mass scale. Cored (non cusped) DM halos and keV WDM are
strongly favored by theory and observations, Wimps are strongly disfavoured.
LambdaCDM with baryons do not work at small scales. Inside galaxy cores,
quantum WDM effects are important. Quantum WDM calculations (Thomas-Fermi)
provide galaxy masses, velocity dispersions and cored profiles and their sizes
in agreement with observations. A WDM fermion of about 2 keV naturally
reproduces galaxy, large scale and cosmological observations. WDM keV particles
deserve dedicated astronomical and laboratory searches, theoretical work and
numerical simulations. KATRIN can be adapted to look to keV scale sterile
neutrinos. It will be a fantastic discovery to detect dark matter in beta
decay. Photos of the Colloquium are includedComment: 58 pages, 15 figures. arXiv admin note: substantial text overlap with
arXiv:1203.3562, arXiv:1305.7452, arXiv:1009.3494, arXiv:1304.075
Towards the Chalonge 16th Paris Cosmology Colloquium 2012: Highlights and Conclusions of the Chalonge 15th Paris Cosmology Colloquium 2011
The Chalonge 15th Paris Cosmology Colloquium 2011 was held on 20-22 July in
the historic Paris Observatory's Perrault building, in the Chalonge School
spirit combining real cosmological/astrophysical data and hard theory
predictive approach connected to them in the Warm Dark Matter Standard Model of
the Universe: News and reviews from Herschel, QUIET, Atacama Cosmology
Telescope (ACT), South Pole Telescole (SPT), Planck, PIXIE, the JWST, UFFO,
KATRIN and MARE experiments; astrophysics, particle and nuclear physics warm
dark matter (DM) searches and galactic observations, related theory and
simulations, with the aim of synthesis, progress and clarification. Philippe
Andre, Peter Biermann, Pasquale Blasi, Daniel Boyanovsky, Carlo Burigana,
Hector de Vega, Joanna Dunkley, Gerry Gilmore, Alexander Kashlinsky, Alan
Kogut, Anthony Lasenby, John Mather, Norma Sanchez, Alexei Smirnov, Sylvaine
Turck-Chieze present here their highlights of the Colloquium. Ayuki Kamada and
Sinziana Paduroiu present here their poster highlights. LambdaWDM (Warm Dark
Matter) is progressing impressively over LambdaCDM whose galactic scale crisis
and decline are staggering. The International School Daniel Chalonge issued an
statement of strong support to the James Webb Space Telescope (JSWT). The
Daniel Chalonge Medal 2011 was awarded to John C. Mather, Science PI of the
JWST. Summary and conclusions are presented by H. J. de Vega, M. C. Falvella
and N. G. Sanchez. Overall, LambdaWDM and keV scale DM particles deserve
dedicated astronomical and laboratory experimental searches, theoretical work
and simulations. KATRIN experiment in the future could perhaps adapt its set-up
to look to keV scale sterile neutrinos. It will be a a fantastic discovery to
detect dark matter in a beta decay. Photos of the Colloquium are included.
(Abridged)Comment: 65 pages, 21 figure
On the difference between proton and neutron spin-orbit splittings in nuclei
The latest experimental data on nuclei at Sn permit us for the first
time to determine the spin-orbit splittings of neutrons and protons in
identical orbits in this neutron-rich doubly-magic region and compare the case
to that of Pb. Using the new results, which are now consistent for the
two neutron-rich doubly magic regions, a theoretical analysis defines the
isotopic dependence of the mean field spin-orbit potential and leads to a
simple explicit expression for the difference between the spin-orbit splittings
of neutrons and protons. The isotopic dependence is explained in the framework
of different theoretical approaches.Comment: 8 pages, revte
String Tension and the Generation of the Conformal Anomaly
The origin of the string conformal anomaly is studied in detail. We use a
reformulated string Lagrangian which allows to consider the string tension
as a small perturbation. The expansion parameter is the worldsheet
speed of light c, which is proportional to . We examine carefully the
interplay between a null (tensionless) string and a tensionful string which
includes orders and higher. The conformal algebra generated by the
constraints is considered. At the quantum level the normal ordering provides a
central charge proportional to . Thus it is clear that quantum null
strings respect conformal invariance and it is the string tension which
generates the conformal anomaly.Comment: More references are included. Final version, to appear in Phys.Rev.D.
6 pages, LaTex, no figure
String propagation in four-dimensional dyonic black hole background
We study string propagation in an exact, four-dimensional dyonic black hole
background. The general solutions describing string configurations are obtained
by solving the string equations of motion and constraints. By using the
covariant formalism, we also investigate the propagation of physical
perturbations along the string in the given curved background.Comment: 19 pages, Tex (macro phyzzx is needed
Advances in String Theory in Curved Backgrounds: A Synthesis Report
A synthetic report of the advances in the study of classical and quantum string dynamics in curved backgrounds is provided, namely: the new feature of multistring solutions; the effect of a cosmological constant and of spacial curvature on classical and quantum strings; classical splitting of fundamental strings;the general string evolution in constant curvature spacetimes;the conformal invariant effects;strings on plane waves, shock waves and spacetime singularities and its spectrum. New developments in string gravity and string cosmology are reported: string driven cosmology and its predictions;the primordial gravitation wave background; non-singular string cosmologies from exact conformal field theories;QFT, string temperature and the string phase of de Sitter space; the string phase of black holes;new dual relation between QFT regimes and string regimes and the 'QFT/String Tango'; new coherent string states and minimal uncertainty principle in string theor
Spin-1/2 "bosons" with mass dimension 3/2 and fermions with mass dimension 1 cannot represent physical particle states
We delve into the first principles of quantum field theory to prove that the so-called spin-1/2 "bosons" and the fermions with mass dimension 1, including ELKO, cannot represent physical particle states with spin 1/2. Specifically, we first demonstrate that both aforementioned fields are not invariant under rotational symmetry, which implies that the particles created for these fields are not eigenstates of the spin operator in the (1/2, 0) circle plus (0, 1/2) representation of the Lorentz group, nor is it possible to construct a Hamiltonian density scalar under the rotational group from them. Furthermore, following Weinberg's approach to local causal fields, we prove that regardless of any discrete symmetry or adjoint structure, the relativistic fields in the (1/2, 0) circle plus (0, 1/2) representation satisfy the Fermi-Dirac statistics in complete agreement with the well-established spin-statistics theorem and experimental results.Peer reviewe
Role of Sterile Neutrino Warm Dark Matter in Rhenium and Tritium Beta Decays
Sterile neutrinos with mass in the range of one to a few keV are important as
extensions of the Standard Model of particle physics and are serious dark
matter (DM) candidates. This DM mass scale (warm DM) is in agreement with both
cosmological and galactic observations. We study the role of a keV sterile
neutrino through its mixing with a light active neutrino in Rhenium 187 and
Tritium beta decays. We pinpoint the energy spectrum of the beta particle, 0 <
T_e < (Q_{beta} - m_s), as the region where a sterile neutrino could be
detected and where its mass m_s could be measured. This energy region is at
least 1 keV away rom the region suitable to measure the mass of the light
active neutrino, located near the endpoint Q_{beta} . The emission of a keV
sterile neutrino in a beta decay could show up as a small kink in the spectrum
of the emitted beta particle. With this in view, we perform a careful
calculation of the Rhenium and Tritium beta spectra and estimate the size of
this perturbation by means of the dimensionless ratio R of the sterile neutrino
to the active neutrino contributions. We comment on the possibility of
searching for sterile neutrino signatures in two experiments which are
currently running at present, MARE and KATRIN, focused on the Rhenium 187 and
Tritium beta decays respectively.Comment: 16 pages, 10 figures. Version to appear in Nucl. Phys. B. Results and
conclusions unchange
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