190 research outputs found
The effect of anticoagulant, storage time and temperature, and sodium azide on blood progesterone concentrations
Determines the effects of anticoagulant, storage time, storage temperature and sodium azide on blood progesterone concentrations in order to develop practical guidelines for the collection of Zebu blood under tropical conditions
Epitaxial growth and thermodynamic stability of SrIrO3/SrTiO3 heterostructures
Obtaining high-quality thin films of 5d transition metal oxides is essential
to explore the exotic semimetallic and topological phases predicted to arise
from the combination of strong electron correlations and spin-orbit coupling.
Here, we show that the transport properties of SrIrO3 thin films, grown by
pulsed laser deposition, can be optimized by considering the effect of
laser-induced modification of the SrIrO3 target surface. We further demonstrate
that bare SrIrO3 thin films are subject to degradation in air and are highly
sensitive to lithographic processing. A crystalline SrTiO3 cap layer deposited
in-situ is effective in preserving the film quality, allowing us to measure
metallic transport behavior in films with thicknesses down to 4 unit cells. In
addition, the SrTiO3 encapsulation enables the fabrication of devices such as
Hall bars without altering the film properties, allowing precise
(magneto)transport measurements on micro- and nanoscale devices.Comment: 5 pages, 3 figure
Essais de production et de collecte d'embryons chez la vache Somba
Des essais de collecte d'embryons ont Ă©tĂ© menĂ©s dans un troupeau de vaches trypanotolĂ©rantes de race Somba, pendant quatre cycles de polyovulation rĂ©alisĂ©s en diffĂ©rentes saisons. Un progestatif (Norgestomet, CrestarÂź Intervet) et des gonadotrophines (soit p-FSH PlusetÂź Serono, soit FolltropinÂź Vetrepharm) ont Ă©tĂ© utilisĂ©s selon des dosages modifiĂ©s en raison du poids des animaux. Les donneuses ont Ă©tĂ© ensuite fĂ©condĂ©es deux fois Ă 12 heures d'intervalle, par saillie naturelle ou insĂ©mination artificielle, la semence de trois taureaux ayant Ă©tĂ© rĂ©coltĂ©e et congelĂ©e sur place en paillettes. Le taux gĂ©nĂ©ral de rĂ©ponse Ă la polyovulation a Ă©tĂ© de 72 p. 100. Les embryons ont Ă©tĂ© collectĂ©s Ă 6,5 jours, au stade de morula compactĂ©e ou de jeune blastocyste. Sur l'ensemble des 30 collectes, 87 embryons ont pu ĂȘtre rĂ©cupĂ©rĂ©s. Parmi ces embryons, 39 (45 p. 100) appartenaient aux catĂ©gories Q1 et Q2 et Ă©taient congelables, 19 (22 p. 100) appartenaient Ă la catĂ©gorie Q3 et les 29 restants (33 p. 100) appartenaient Ă la catĂ©gorie Q4 (non transfĂ©rables). La production moyenne d'embryons transfĂ©rables (1,9 par donneuse) n'a pas Ă©tĂ© affectĂ©e significativement par le type de gonadotrophine utilisĂ©, mais le taux d'embryons congelables a Ă©tĂ© plus Ă©levĂ© en saison humide fraĂźche qu'en saison humide chaude (respectivement 59 vs 38 p. 100)
High-order Harmonic Generation and its Unconventional Scaling Law in the Mott-insulating
Competition and cooperation among orders is at the heart of many-body physics
in strongly correlated materials and leads to their rich physical properties.
It is crucial to investigate what impact many-body physics has on extreme
nonlinear optical phenomena, with the possibility of controlling material
properties by light. However, the effect of competing orders and
electron-electron correlations on highly nonlinear optical phenomena has not
yet been experimentally clarified. Here, we investigated high-order harmonic
generation from the Mott-insulating phase of Ca2RuO4. Changing the gap energy
in Ca2RuO4 as a function of temperature, we observed a strong enhancement of
high order harmonic generation at 50 K, increasing up to several hundred times
compared to room temperature. We discovered that this enhancement can be
well-reproduced by an empirical scaling law that depends only on the material
gap energy and photon emission energy. Such scaling law cannot be explained by
a simple two-band model under the single electron approximation. Our results
suggest that the highly nonlinear optical response of strongly correlated
materials is deeply coupled to their electron-electron correlations and
resultant many-body electronic structure
Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT
The gravitational spectrometer GRANIT will be set up at the Institut Laue
Langevin. It will profit from the high ultracold neutron density produced by a
dedicated source. A monochromator made of crystals from graphite intercalated
with potassium will provide a neutron beam with 0.89 nm incident on the source.
The source employs superthermal conversion of cold neutrons in superfluid
helium, in a vessel made from BeO ceramics with Be windows. A special
extraction technique has been tested which feeds the spectrometer only with
neutrons with a vertical velocity component v < 20 cm/s, thus keeping the
density in the source high. This new source is expected to provide a density of
up to 800 1/cm3 for the spectrometer.Comment: accepted for publication in Proceedings International Workshop on
Particle Physics with Slow Neutron
Effect of a novel drug-eluted balloon coated with genistein before stent implantation in porcine coronary arteries
Mean Field Theory of Josephson Junction Arrays with Charge Frustration
Using the path integral approach, we provide an explicit derivation of the
equation for the phase boundary for quantum Josephson junction arrays with
offset charges and non-diagonal capacitance matrix. For the model with nearest
neighbor capacitance matrix and uniform offset charge , we determine,
in the low critical temperature expansion, the most relevant contributions to
the equation for the phase boundary. We explicitly construct the charge
distributions on the lattice corresponding to the lowest energies. We find a
reentrant behavior even with a short ranged interaction. A merit of the path
integral approach is that it allows to provide an elegant derivation of the
Ginzburg-Landau free energy for a general model with charge frustration and
non-diagonal capacitance matrix. The partition function factorizes as a product
of a topological term, depending only on a set of integers, and a
non-topological one, which is explicitly evaluated.Comment: LaTex, 24 pages, 8 figure
Electronic and optical properties of families of polycyclic aromatic hydrocarbons: a systematic (time-dependent) density functional theory study
Homologous classes of Polycyclic Aromatic Hydrocarbons (PAHs) in their
crystalline state are among the most promising materials for organic
opto-electronics. Following previous works on oligoacenes we present a
systematic comparative study of the electronic, optical, and transport
properties of oligoacenes, phenacenes, circumacenes, and oligorylenes. Using
density functional theory (DFT) and time-dependent DFT we computed: (i)
electron affinities and first ionization energies; (ii) quasiparticle
correction to the highest occupied molecular orbital (HOMO)-lowest unoccupied
molecular orbital (LUMO) gap; (iii) molecular reorganization energies; (iv)
electronic absorption spectra of neutral and charged systems. The
excitonic effects are estimated by comparing the optical gap and the
quasiparticle corrected HOMO-LUMO energy gap. For each molecular property
computed, general trends as a function of molecular size and charge state are
discussed. Overall, we find that circumacenes have the best transport
properties, displaying a steeper decrease of the molecular reorganization
energy at increasing sizes, while oligorylenes are much more efficient in
absorbing low-energy photons in comparison to the other classes.Comment: 26 pages, 9 figures, 4 tables, accepted for pubblication in Chemical
Physics (14/04/2011
âI luoghi di Mercalliâ: a travelling exhibition as a tool for scientists to dialogue with the public on volcanoes and earthquakes
On March 19, 1914 Giuseppe Mercalli, a seismologist and volcanologist, well-known around the world for the
Intensity scale of earthquakes bearing his name, died tragically. A hundred years after, the Istituto Nazionale di
Geofisica e Vulcanologia (INGV) has promoted a variety of activities and cultural events that will take place under the
Patronage of the President of the Italian Republic within a year, the so called âAnno Mercallianoâ (the Year of
Mercalli).
The opening ceremony took place in Naples, Italy, on March 19, 2014, in the Convitto Nazionale Vittorio Emanuele
II. A scientific conference was held with the participation of experts from INGV and the university of Milano â
Bicocca, and presentations of students. On that day the exhibition entitled âI luoghi di Mercalliâ (Mercalli's places) was
also inaugurated, at the presence of local authorities.
The exhibition, organized by INGV, was realized in collaboration with the high school Vittorio Emanuele II, where
Mercalli has been teaching for 19 years, and the UniversitĂ degli Studi Suor Orsola Benincasa, where he was professor
of natural sciences.
A biographical and geographical description of the places where Mercalli operated introduces the exhibition, which
is organized in sections:
- Mercalli educator (he taught at high schools in Reggio Calabria and Naples);
- Mercalli volcanologist (Mercalli studied Vesuvius volcanic activity for more than twenty years, he was a scientific
witness of the Vesuvius 1906 eruption, and of the eruptions occurred at Vulcano (1888-90) and Stromboli (1891)
islands.
- Mercalli seismologist (Mercalli Intensity scale definition, based on his experience as witness of catastrophic
earthquakes, such as Casamicciola in 1883 and Messina in 1908).
Another section deals with the Vesuvius Observatory, directed by Mercalli between 1911 and 1914, and the
description of the three active volcanoes of the Campania region (Vesuvius, Campi Flegrei and Ischia island), which
have been the subject of studies by the well-known scientist. The exhibition is enriched by documents, manuscripts,
photos and field notebooks of Mercalli.
It is not intended to be only a celebratory exhibition; rather it is designed as a tool for dissemination of scientific
culture and to raise awareness about seismic and volcanic hazards.
In the exhibition path a continuous thread between the figure of Mercalli as a researcher and the role of an Earth
Science researcher today is highlighted, pointing to the development of scientific knowledge in the past century. The
goal is to improve the capability of learning from the disasters occurred in the past to implement preventive actions to
safely deal with future events.
The exhibition is travelling and will be provided on request to institutions and schools.PublishedMilano, Italia1V. Storia e struttura dei sistemi vulcaniciope
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