The three-body recombination of a condensed Bose gas near a Feshbach resonance

In this paper, we study the three-body recombination rate of a homogeneous dilute Bose gas with a Feshbach resonance at zero temperature. The ground state and excitations of this system are obtained. The three-body recombination in the ground state is due to the break-up of an atom pair in the quantum depletion and the formation of a molecule by an atom from the broken pair and an atom from the condensate. The rate of this process is in good agreement with the experiment on $^{23}$Na in a wide range of magnetic fields.Comment: 10 pages, 2 figures, to be published in Phys. Rev.

Defect turbulence in inclined layer convection

We report experimental results on the defect turbulent state of undulation chaos in inclined layer convection of a fluid withPrandtl number $\approx 1$. By measuring defect density and undulation wavenumber, we find that the onset of undulation chaos coincides with the theoretically predicted onset for stable, stationary undulations. At stronger driving, we observe a competition between ordered undulations and undulation chaos, suggesting bistability between a fixed-point attractor and spatiotemporal chaos. In the defect turbulent regime, we measured the defect creation, annihilation, entering, leaving, and rates. We show that entering and leaving rates through boundaries must be considered in order to describe the observed statistics. We derive a universal probability distribution function which agrees with the experimental findings.Comment: 4 pages, 5 figure

New antineutrino energy spectra predictions from the summation of beta decay branches of the fission products

In this paper, we study the impact of the inclusion of the recently measured beta decay properties of the $^{102;104;105;106;107}$Tc, $^{105}$Mo, and $^{101}$Nb nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes $^{235, 238}$U, and $^{239,241}$Pu. These actinides are the main contributors to the fission processes in Pressurized Water Reactors. The beta feeding probabilities of the above-mentioned Tc, Mo and Nb isotopes have been found to play a major role in the $\gamma$ component of the decay heat of $^{239}$Pu, solving a large part of the $\gamma$ discrepancy in the 4 to 3000\,s range. They have been measured using the Total Absorption Technique (TAS), avoiding the Pandemonium effect. The calculations are performed using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of $^{235}$U, $^{239,241}$Pu and in particular of $^{238}$U for which no measurement has been published yet. We conclude that new TAS measurements are mandatory to improve the reliability of the predicted spectra.Comment: 10 pages, 2 figure

Correlating densities of centrality and activities in cities : the cases of Bologna (IT) and Barcelona (ES)

This paper examines the relationship between street centrality and densities of commercial and service activities in cities. The aim is to verify whether a correlation exists and whether some 'secondary' activities, i.e. those scarcely specialized oriented to the general public and ordinary daily life, are more linked to street centrality than others. The metropolitan area of Barcelona (Spain) is investigated, and results are compared with those found in a previous work on the city of Bologna (Italy). Street centrality is calibrated in a multiple centrality assessment (MCA) model composed of multiple measures such as closeness, betweenness and straightness. Kernel density estimation (KDE) is used to transform data sets of centrality and activities to one scale unit for correlation analysis between them. Results indicate that retail and service activities in both Bologna and Barcelona tend to concentrate in areas with better centralities, and that secondary activities exhibit a higher correlation

Performances and stability of a 2.4 ton Gd organic liquid scintillator target for antineutrino detection

In this work we report the performances and the chemical and physical properties of a (2 x 1.2) ton organic liquid scintillator target doped with Gd up to ~0.1%, and the results of a 2 year long stability survey. In particular we have monitored the amount of both Gd and primary fluor actually in solution, the optical and fluorescent properties of the Gd-doped liquid scintillator (GdLS) and its performances as a neutron detector, namely neutron capture efficiency and average capture time. The experimental survey is ongoing, the target being continuously monitored. After two years from the doping time the performances of the Gd-doped liquid scintillator do not show any hint of degradation and instability; this conclusion comes both from the laboratory measurements and from the "in-tank" measurements. This is the largest stable Gd-doped organic liquid scintillator target ever produced and continuously operated for a long period

Quasi-probability representations of quantum theory with applications to quantum information science

This article comprises a review of both the quasi-probability representations of infinite-dimensional quantum theory (including the Wigner function) and the more recently defined quasi-probability representations of finite-dimensional quantum theory. We focus on both the characteristics and applications of these representations with an emphasis toward quantum information theory. We discuss the recently proposed unification of the set of possible quasi-probability representations via frame theory and then discuss the practical relevance of negativity in such representations as a criteria for quantumness.Comment: v3: typos fixed, references adde

Quantum tomography of mesoscopic superpositions of radiation states

We show the feasibility of a tomographic reconstruction of Schr\"{o}dinger cat states generated according to the scheme proposed by S. Song, C.M. Caves and B. Yurke [Phys. Rev. A 41, 5261 (1990)]. We present a technique that tolerates realistic values for quantum efficiency at photodetectors. The measurement can be achieved by a standard experimental setup.Comment: Submitted to Phys. Rev. Lett.; 4 pages including 6 ps figure

Molecular farming of human tissue transglutaminase in tobacco plants

In this study we have utilized Nicotiana tabacum with a molecular farming purpose in attempt of producing transgenic plants expressing the human tissue transglutaminase (htTG). Three plant expression constructs were used enabling targeting and accumulation of the recombinant protein into the plant cell cytosol (cyto), the chloroplasts (chl) and the apoplastic space (apo). Analysis of transgenic T(0) plants revealed that recombinant htTG was detectable in all three transgenic lines and the accumulation levels were in a range of 18-75 mu g/g of leaf material. In the T(1) generation, the recombinant htTG was still expressed at high level and a significant catalytic activity was detected into the leaf protein extracts. Southern blot analyses revealed that apo and chl plants of T(1) generation possess a high copy number of the recombinant htTG in their genome, while the cyto plants carry a single copy

Lagrangian Statistics and Temporal Intermittency in a Shell Model of Turbulence

We study the statistics of single particle Lagrangian velocity in a shell model of turbulence. We show that the small scale velocity fluctuations are intermittent, with scaling exponents connected to the Eulerian structure function scaling exponents. The observed reduced scaling range is interpreted as a manifestation of the intermediate dissipative range, as it disappears in a Gaussian model of turbulence.Comment: 4 pages, 5 figure