538 research outputs found
Attitudes de consommateurs de viande bovine vis-à-vis du bien-être animal : une comparaison régionale dans la zone pyrénéenne
Attitudes towards animal welfare (AW) are investigated in two Spanish and two French regions located on both sides of the Pyrenees (n=1213). Two scores are used: one measuring the importance of 11 good practices for AW and one capturing the consumers´ trust regarding stakeholder behaviour. Items linked with animal life conditions get the highest scores of importance. Trust scores are of a lower magnitude and statistically significant differences are found across regions. Finally, socio-demographic characteristics and meat purchase and consumption habits explain part of the observed attitudinal differences found among respondent
Apatite germanates doped with tungsten: Synthesis, structure, and conductivity
et al.High oxygen content apatite germanates, La10Ge 6-xWxO27+x, have been prepared by doping on the Ge site with W. In addition to increasing the oxygen content, this doping strategy is shown to result in stabilisation of the hexagonal lattice, and yield high conductivities. Structural studies of La10Ge 5.5W0.5O27.5 show that the interstitial oxygen sites are associated to a different degree with the Ge/WO4 tetrahedra, leading to five coordinate Ge/W and significant disorder for the oxygen sites associated with these units. Raman spectroscopy studies suggest that in the case of the WO5 units, the interstitial oxygen is more tightly bonded and therefore not as mobile as in the case of the GeO5 units, thus not contributing significantly to the conduction process. © 2011 The Royal Society of Chemistry.Financial support from Spanish project MAT2007-64486-C07-02 is acknowledged.Peer Reviewe
Alumnos con deficiencia psíquica: aspectos a tener en cuenta en las clases de educación física
Los alumnos con deficiencia psíquica tienen los mismos estadios de desarrollo que el resto de niños, pero tienen un retraso en su desarrollo. A esto se añaden una serie de características afectivas, sociales, etc., que hay que tener en cuenta para planificar la clase. El artículo propone una seria de aspectos metodológicos que nos van a permitir dar las clases en óptimas condiciones
Raman selection rules in uniaxial media: The nonpolar modes of Mn Ga2 Se4
Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).It is known that optically anisotropic media can change the polarization of light propagating inside them. As regards Raman spectroscopy, this affects the light intensity measured in different geometrical configurations and results in an apparent unfulfillment of selection rules. We present an experimental and theoretical study of such effects in the defect chalcopyrite semiconductor MnGa2Se4. Optical anisotropy is taken into account by including in the calculation of Raman intensities the phase difference appearing between ordinary and extraordinary waves as they propagate, in uniaxial media, with different velocities. Birefringence can be obtained from Raman measurements provided that the distance run by the light is known.We acknowledge financial support from research project MAT2001-3713-C04.Peer Reviewe
Energy dissipation in a nonlinearly damped Duffing oscillator
International audienceIn this paper, we study the effect of including a nonlinear damping term proportional to the power of the velocity in the dynamics of a double-well Duffing oscillator. In particular, we focus our attention in understanding how the energy dissipates over a cycle and along the time, by the use of different tools of analysis. Analytical and numerical results for different damping terms are shown, and the presence of a discontinuity and an inversion of behavior depending on the initial energy are discussed. An averaged power loss in a period is defined, showing similar characteristics as the energy dissipation over a cycle, although no discontinuity is present. The discontinuity gap which appears for the energy dissipation at a certain value of the initial energy decreases as the power of the damping term increases and an associated scaling law is found
The LISA PathFinder DMU and Radiation Monitor
The LISA PathFinder DMU (Data Management Unit) flight model was formally
accepted by ESA and ASD on 11 February 2010, after all hardware and software
tests had been successfully completed. The diagnostics items are scheduled to
be delivered by the end of 2010. In this paper we review the requirements and
performance of this instrumentation, specially focusing on the Radiation
Monitor and the DMU, as well as the status of their programmed use during
mission operations, on which work is ongoing at the time of writing.Comment: 11 pages, 7 figures, prepared for the Proceedings of the 8th
International LISA Symposium, Classical and Quantum Gravit
Interstitial oxide ion distribution and transport mechanism in aluminum-doped neodymium silicate apatite electrolytes
et al.Rare earth silicate apatites are one-dimensional channel structures that show potential as electrolytes for solid oxide fuel cells (SOFC) due to their high ionic conductivity at intermediate temperatures (500-700 °C). This advantageous property can be attributed to the presence of both interstitial oxygen and cation vacancies, that create diffusion paths which computational studies suggest are less tortuous and have lower activation energies for migration than in stoichiometric compounds. In this work, neutron diffraction of NdAlSiO (0 ≤ x ≤ 1.5) single crystals identified the locations of oxygen interstitials, and allowed the deduction of a dual-path conduction mechanism that is a natural extension of the single-path sinusoidal channel trajectory arrived at through computation. This discovery provides the most thorough understanding of the O transport mechanism along the channels to date, clarifies the mode of interchannel motion, and presents a complete picture of O percolation through apatite. Previously reported crystallographic and conductivity measurements are re-examined in the light of these new findings.We are pleased to acknowledge the Agency for Science, Technology and Research (A*STAR) PSF grant 082 101 0021 “Optimization of Oxygen Sublattices in Solid Oxide Fuel Cell Apatite Electrolytes” for funding the work and the Ministry of Education (MOE) Tier 2 grant T208B1212 for enabling the purchase of a single crystal X-ray diffractometer.Peer Reviewe
Neural network interpolation of the magnetic field for the LISA Pathfinder Diagnostics Subsystem
LISA Pathfinder is a science and technology demonstrator of the European
Space Agency within the framework of its LISA mission, which aims to be the
first space-borne gravitational wave observatory. The payload of LISA
Pathfinder is the so-called LISA Technology Package, which is designed to
measure relative accelerations between two test masses in nominal free fall.
Its disturbances are monitored and dealt by the diagnostics subsystem. This
subsystem consists of several modules, and one of these is the magnetic
diagnostics system, which includes a set of four tri-axial fluxgate
magnetometers, intended to measure with high precision the magnetic field at
the positions of the test masses. However, since the magnetometers are located
far from the positions of the test masses, the magnetic field at their
positions must be interpolated. It has been recently shown that because there
are not enough magnetic channels, classical interpolation methods fail to
derive reliable measurements at the positions of the test masses, while neural
network interpolation can provide the required measurements at the desired
accuracy. In this paper we expand these studies and we assess the reliability
and robustness of the neural network interpolation scheme for variations of the
locations and possible offsets of the magnetometers, as well as for changes in
environmental conditions. We find that neural networks are robust enough to
derive accurate measurements of the magnetic field at the positions of the test
masses in most circumstances
On-ground tests of LISA PathFinder thermal diagnostics system
Thermal conditions in the LTP, the LISA Technology Package, are required to
be very stable, and in such environment precision temperature measurements are
also required for various diagnostics objectives. A sensitive temperature
gauging system for the LTP is being developed at IEEC, which includes a set of
thermistors and associated electronics. In this paper we discuss the derived
requirements applying to the temperature sensing system, and address the
problem of how to create in the laboratory a thermally quiet environment,
suitable to perform meaningful on-ground tests of the system. The concept is a
two layer spherical body, with a central aluminium core for sensor implantation
surrounded by a layer of polyurethane. We construct the insulator transfer
function, which relates the temperature at the core with the laboratory ambient
temperature, and evaluate the losses caused by heat leakage through connecting
wires. The results of the analysis indicate that, in spite of the very
demanding stability conditions, a sphere of outer diameter of the order one
metre is sufficient. We provide experimental evidence confirming the model
predictions.Comment: 18 pages, 5 figures, LaTeX2e (compile with pdflatex), sumbitted to
CQG. This paper is a significant extension of gr-qc/060109
The electrochemistry of 5-halocytosines at carbon based electrodes towards epigenetic sensing
Epigenetic modifications in DNA are strongly linked to the triggering and development of pathophysiological disorders and cancer diseases. The halogenation of DNA via radical species, particularly the formation of 5-chlorocytosine (ClC), has recently emerged as epigenetic modification. This work deals for the first time with the exploration of the electrochemical behaviour of ClC on different carbon electrodes such as glassy carbon and boron-doped diamond using cyclic voltammetry and square wave voltammetry. When comparing both carbon materials, the use of glassy carbon turned out to be the appropriate in terms of a more well-defined anodic wave and higher sensitivity. The electrochemical oxidation potential of ClC resulted to be linearly dependent on the pH with a maximum current intensity in acetic acid buffer solution under the conditions used. Moreover, a linear response between peak current intensity and ClC concentration was obtained within the range of 200 and 1000 μM with a limit of detection of 200 μM. In order to elucidate the reaction mechanism of the process, the main oxidation products after a preparative electrolysis were detected by HPLC-MS. Simultaneous detection of ClC in the presence of the unmodified cytosine and mixtures containing other nucleic bases such as guanine, adenine and thymine was also addressed. Finally, the effect of the halogen atom (X = F, Cl, Br) located at position C-5 of the cytosine entity upon the electrooxidation process was examined by theoretical calculations, too.I.S.M., N.H.I. and J.I. thank the Ministerio de Economia y Competitividad MINECO, Spain for its financial support by the research projects CTQ2013-48280-C3-3-R and CTQ2016-76231-C2-2-R
- …