Traumatismo encéfalocraneano por agresión con objeto contundente sólido

Fil: Cutroni, Francisco. Universidad Nacional de Cuyo. Facultad de Ciencias MédicasFil: Santamarina, M.. Universidad Nacional de Cuyo. Facultad de Ciencias Médica

Effects of grain size distribution on the initial strain shear modulus of calcareous sand

The soil’s small strain shear modulus, Gmax or G0, is applied in dynamic behavior analyses and is correlated to other soil properties (density and void ratio) for predicting soil dynamic behavior under seismic loadings such as earthquakes, machinery or traffic vibrations. However, for calcareous sands, selecting representative samples for the field conditions is difficult; therefore, almost all measured soil parameters (post-seismic properties) do not reflect exactly the soil state before seismic loading. In some cases of dynamic loading, a change in grain size distribution (GSD) of soils, especially for calcareous sands might occur. Moreover, many of these sand types behave differently from silica sands owing to their mineralogy, particle characterization, soil skeleton, and the continuous changing of particle size. For this reason, a series of isotropic consolidation tests in ranges of confining pressure from 25 to 300 kPa as well as bender element measurements on a calcareous sand and on a reference silica sand were performed in this study. The effects of differences in gradation and in the type of material on the soil’s small strain shear modulus, Gmax, are discussed

The pion-pion scattering lengths from DIRAC

The scattering lengths of a two pion system are the {\it golden magnitudes} to test the QCD predictions in the low energy sector. The DIRAC (PS-212) experiment at CERN will obtain a particular combination of the S-wave isospin 0 and 2 scattering lengths by measuring the lifetime of pionium, the hydrogen-like $\pi^+ \pi^-$ atom. This measurement tests the accurate predictions of the Chiral Perturbation Theory. The most recent experimental results are presented.Comment: Talk presented at Xth International Conference on Hadron Spectroscopy HADRON '03, August 31 -- September 6, 2003, Aschaffenburg, German

Dynamics of the Pionium with the Density Matrix Formalism

The evolution of pionium, the $\pi^+ \pi^-$ hydrogen-like atom, while passing through matter is solved within the density matrix formalism in the first Born approximation. We compare the influence on the pionium break-up probability between the standard probabilistic calculations and the more precise picture of the density matrix formalism accounting for interference effects. We focus our general result in the particular conditions of the DIRAC experiment at CERN.Comment: 14 pages, 2 figures, submitted to J. Phys. B: At. Mol. Phy

Commissioning of the ATLAS Electron and Photon Trigger Selection

Since the start-up of the LHC end of 2009, the trigger commissioning is in full swing. The ATLAS trigger system is divided into three levels: the hardware-based first level trigger, and the software-based second level trigger and Event Filter, collectively referred to as the High Level Trigger (HLT). Initially, events have been selected online based on the Level-1 selections with the HLT algorithms run but not rejecting any events. This has been an important step in the commissioning of these triggers to ensure their correct functioning and subsequently to enable the HLT selections. Due to increasing LHC luminosity and the large QCD cross section, this has been a vital step to select leptons from J/$\Psi$, bottom, charm, W and Z decays. This presentation gives an overview of the trigger performance of the electron and photon selection. Comparisons of the online selection variables with the offline reconstruction are shown as well as comparisons of data with MC simulations on which the current selection tuning is performed.Comment: Contribution to the proceedings of the Hadron Collider Physics 2010 symposium held in Toronto. Three pages and 2 Figure

Faculty in the News: September 9, 2016

Juan Santamarina discusses recent changes in U.S.-Cuba relations and how they affect our nation\u27s tourism industry, and other highlights of recent media coverage of College of Arts and Sciences faculty research, scholarship and commentary

Cuba: A Lifetime of Passion

A new documentary film from University of Dayton historian Juan Santamarina and alumnus Glenn Gebhard explores Cuba’s difficult past and uncertain future — with a spotlight on the people affected today by the Cuban Revolution

The Galician fiddle style

Publisher PD

Experimental study on the cyclic resistance of a natural loess from Northern France

In order to analyze the instability phenomenon observed along the Northern High Speed Line of R\'eseau Ferr\'e de France (RFF), soil blocks were taken at a site near the railway, at four different depths (1.2, 2.2, 3.5 and 4.9 m). Cyclic triaxial tests were carried out on saturated and unsaturated soil specimens. The results from tests on initially saturated specimens showed that the soil taken at 2.2 m depth has the lowest resistance to cyclic loading, in relation to its highest porosity and lowest clay fraction. This soil was then studied at unsaturated state with various initial water contents. Unsaturated soil specimens were first subjected to cyclic loadings to decrease their volume. These cyclic loadings was stopped when the volume decrease was approximately equal to the initial pore air volume, or when the pores filled by air were eliminated and the soil was considered to become saturated. Afterwards, the back-pressure tubing was saturated with de-aired water and cycles were applied under undrained condition. Significant effect of initial water content was evidenced: the lower the initial water content, the higher the cyclic resistance. This can be explained by the densification of the soil during the initial cyclic loadings