15,555 research outputs found
Estimation of the gravitational wave polarizations from a non template search
Gravitational wave astronomy is just beginning, after the recent success of
the four direct detections of binary black hole (BBH) mergers, the first
observation from a binary neutron star inspiral and with the expectation of
many more events to come. Given the possibility to detect waves from not
perfectly modeled astrophysical processes, it is fundamental to be ready to
calculate the polarization waveforms in the case of searches using non-template
algorithms. In such case, the waveform polarizations are the only quantities
that contain direct information about the generating process. We present the
performance of a new valuable tool to estimate the inverse solution of
gravitational wave transient signals, starting from the analysis of the signal
properties of a non-template algorithm that is open to a wider class of
gravitational signals not covered by template algorithms. We highlight the
contributions to the wave polarization associated with the detector response,
the sky localization and the polarization angle of the source. In this paper we
present the performances of such method and its implications by using two main
classes of transient signals, resembling the limiting case for most simple and
complicated morphologies. Performances are encouraging, for the tested
waveforms: the correlation between the original and the reconstructed waveforms
spans from better than 80% for simple morphologies to better than 50% for
complicated ones. For a not-template search this results can be considered
satisfactory to reconstruct the astrophysical progenitor
Traditional Wisdom and Monte Carlo Tree Search Face-to-Face in the Card Game Scopone
We present the design of a competitive artificial intelligence for Scopone, a
popular Italian card game. We compare rule-based players using the most
established strategies (one for beginners and two for advanced players) against
players using Monte Carlo Tree Search (MCTS) and Information Set Monte Carlo
Tree Search (ISMCTS) with different reward functions and simulation strategies.
MCTS requires complete information about the game state and thus implements a
cheating player while ISMCTS can deal with incomplete information and thus
implements a fair player. Our results show that, as expected, the cheating MCTS
outperforms all the other strategies; ISMCTS is stronger than all the
rule-based players implementing well-known and most advanced strategies and it
also turns out to be a challenging opponent for human players.Comment: Preprint. Accepted for publication in the IEEE Transaction on Game
The Impact of Euro-Mediterranean Partnerships on the Agricultural Sector of the Mediterranean Area
In 1995, the Barcelona Conference Inter-government Euro-Mediterranean, through the plan of the creation of the partnership Euro-Mediterranean, has marked the start of a phase of collaboration between the European Union and the Mediterranean Partner Countries (MPCs) that has origin in the importance that these last ones cover in order to assure conditions of stability and peace in the Mediterranean area. Draft of an ambitious plan turned to the creation of solid report and long-lasting relationships between the countries of the north banks and those of the south. Agricultural sector is one of the most important sectors in the economies of the MPCs.Mediterranean Partner Countries (MPC), free trade area, import, export, International Relations/Trade, Q17,
Competitive reaction modelling in aqueous systems. The case of contemporary reduction of dichromates and nitrates by nZVI
In various Countries, Cr(VI) still represents one of the groundwater pollutant of major concern, mainly due to its high toxicity, furthermore enhanced by the synergic effect in presence of other contaminants. As widely reported in the recent literature, nanoscale zero valent iron particles (nZVI-p) have been proved to be particularly effective in the removal of a wide range of contaminants from polluted waters. In this work, experimental tests of hexavalent chromium reduction in polluted groundwater in the presence of nitrate by nZVI-p are presented and discussed. The effect of different nitrate amounts on Cr(VI) reduction mechanism was investigated and the obtained results were successfully interpreted by the proposed kinetic model. nZVI-p produced by the classical borohydride reduction method were added in to synthetic solutions with the initial concentration of Cr(VI) set at 93, 62 and 31 mg L-1 and different nitrate contents in the range 10-100 mg L-1. According to the experimental results, nitrate showed an adverse effect on Cr(VI) reduction, depending on the nZVI/Cr(VI) and Cr(VI)/NO3 - ratio. The proposed kinetic model soundly grasps the competitive nature of the Cr(VI) reduction process when other chemical species are present in the treated solution
nZVI particles production for the remediation of soil and water polluted by inorganic Lead
The present study deals with experiments of Pb removal by
nano-Zero Valent Iron (nZVI) in aqueous solution and in
soil. Synthetic Pb aqueous solutions were treated by nZVI,
at a fixed Pb concentration of 100 mg L-1
, varying
nanoparticles initial concentration in the range between 27
and 270 mg nZVI L-1
. A kinetic study was carried out: Pb
adsorption followed a first order kinetic, and half life times
between 11 and 26.66 min were determined. Soil samples
were first characterized, and Pb speciation and
concentration by sequential extractions was determined.
Adsorption tests were then carried out at three selected
amounts of nZVI, to allow Pb stabilization in the soil
matrix. To evaluate the treatment efficiency, sequential
extractions were also performed on the treated samples
Revised predictions of neutrino fluxes from Pulsar Wind Nebulae
Several Pulsar Wind Nebulae (PWNe) have been detected in the TeV band in the
last decade.The TeV emission is typically interpreted in a purely leptonic
scenario, but this usually requires that the magnetic field in the Nebula be
much lower than the equipartition value and the assumption of an enhanced
target radiation at IR frequencies. In this work we consider the possibility
that, in addition to the relativistic electrons, also relativistic hadrons are
present in these nebulae. Assuming that part of the emitted TeV photons are of
hadronic origin, we compute the associated flux of TeV neutrinos.
We use the IceCube non detection to put constraints on the fraction of TeV
photons that might be contributed by hadrons and estimate the number of
neutrino events that can be expected from these sources in ANTARES and in
KM3Net.Comment: Submitted to ApJ, 12 pages, 3 figure
Hexavalent chromium reduction in manganese-rich soils by ZVI nanoparticles: the influence of natural organic matter and manganese oxides
Hexavalent chromium reduction by nano Zero-Valent Iron
(nZVI) has been proved fast and efficient, mainly due to
nanoparticles large specific surface area and high chemical
reactivity. In this work the influence of natural organic
matter and manganese oxide was investigated, through a
set of experimental tests carried out on a real polluted soils
naturally rich in manganese. Soil samples were
characterized in terms of initial concentration of Cr,
Cr(VI), Mn, pH, and TOC and three different nZVI
solutions were used (120, 360 and 600 mg nZVI L-1
) for
the treatment. At selected interval times (0, 5, 10, 15, 30,
60, 120 min) a slurry sample was filtered and Cr(VI)
residual concentration and pH were measured. The same
procedure was carried out on an artificial spiked soil,
characterized by a similar TOC and poor of Mn.
Furthermore the two soils were mixed with different
amounts of leonardite, to evaluate the influence of NOM
on treatment efficiency
A new lattice Boltzmann model for interface reactions between immiscible fluids
In this paper, we describe a lattice Boltzmann model to simulate chemical reactions taking place at the interface between two immiscible fluids. The phase-field approach is used to identify the interface and its orientation, the concentration of reactant at the interface is then calculated iteratively to impose the correct reactive flux condition. The main advantages of the model is that interfaces are considered part of the bulk dynamics with the corrective reactive flux introduced as a source/sink term in the collision step, and, as a consequence, the model’s implementation and performance is independent of the interface geometry and orientation. Results obtained with the proposed model are compared to analytical solution for three different benchmark tests (stationary flat boundary, moving flat boundary and dissolving droplet). We find an excellent agreement between analytical and numerical solutions in all cases. Finally, we present a simulation coupling the Shan Chen multiphase model and the interface reactive model to simulate the dissolution of a collection of immiscible droplets with different sizes rising by buoyancy in a stagnant fluid
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