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 été menés dans un troupeau de vaches trypanotolérantes de race Somba, pendant quatre cycles de polyovulation réalisés en différentes saisons. Un progestatif (Norgestomet, Crestar® Intervet) et des gonadotrophines (soit p-FSH Pluset® Serono, soit Folltropin® Vetrepharm) ont été utilisés selon des dosages modifiés en raison du poids des animaux. Les donneuses ont été ensuite fécondées deux fois à 12 heures d'intervalle, par saillie naturelle ou insémination artificielle, la semence de trois taureaux ayant été récoltée et congelée sur place en paillettes. Le taux général de réponse à la polyovulation a été de 72 p. 100. Les embryons ont été collectés à 6,5 jours, au stade de morula compactée ou de jeune blastocyste. Sur l'ensemble des 30 collectes, 87 embryons ont pu être récupérés. Parmi ces embryons, 39 (45 p. 100) appartenaient aux catégories Q1 et Q2 et étaient congelables, 19 (22 p. 100) appartenaient à la catégorie Q3 et les 29 restants (33 p. 100) appartenaient à la catégorie Q4 (non transférables). La production moyenne d'embryons transférables (1,9 par donneuse) n'a pas été affectée significativement par le type de gonadotrophine utilisé, mais le taux d'embryons congelables a été plus élevé en saison humide fraîche qu'en saison humide chaude (respectivement 59 vs 38 p. 100)

High-order Harmonic Generation and its Unconventional Scaling Law in the Mott-insulating Ca2RuO4\rm{Ca_2RuO_4}

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

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 $q/2e=1/2$, 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 $\pm1$ 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

Ag/In lead‐free double perovskites

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“I luoghi di Mercalli”: 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 “Anno Mercalliano” (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 – Bicocca, and presentations of students. On that day the exhibition entitled “I luoghi di Mercalli” (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 Università 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