1,276 research outputs found
Production of Strange Clusters and Strange Matter in Nucleus-Nucleus Collisions at the AGS
Production probabilities for strange clusters and strange matter in Au+Au
collisions at AGS energy are obtained in the thermal fireball model. The only
parameters of the model, the baryon chemical potential and temperature, were
determined from a description of the rather complete set of hadron yields from
Si+nucleus collisions at the AGS. For the production of light nuclear fragments
and strange clusters the results are similar to recent coalescence model
calculations. Strange matter production with baryon number larger than 10 is
predicted to be much smaller than any current experimental sensitivities.Comment: 9 Pages (no figures
Missed Opportunities: Evolution of Patients Leaving without Being Seen or against Medical Advice during a Six-Year Period in a Swiss Tertiary Hospital Emergency Department.
Aim. The study aimed at describing the evolution over a 6-year period of patients leaving the emergency department (ED) before being seen ("left without being seen" or LWBS) or against medical advice ("left against medical advice" or LAMA) and at describing their characteristics. Methods. A retrospective database analysis of all adult patients who are admitted to the ED, between 2005 and 2010, and who left before being evaluated or against medical advice, in a tertiary university hospital. Results. During the study period, among the 307,716 patients who were registered in the ED, 1,157 LWBS (0.4%) and 1,853 LAMA (0.9%) patients were identified. These proportions remained stable over the period. The patients had an average age of 38.5 ± 15.9 years for LWBS and 41.9 ± 17.4 years for LAMA. The median time spent in the ED before leaving was 102.4 minutes for the LWBS patients and 226 minutes for LAMA patients. The most frequent reason for LAMA was related to the excessive length of stay. Conclusion. The rates of LWBS and LAMA patients were low and remained stable. The patients shared similar characteristics and reasons for leaving were largely related to the length of stay or waiting time
LâIndice de biodiversitĂ© potentielle (IBP) en rĂ©gion mĂ©diterranĂ©enne
LâIBP est un outil pour Ă©valuer la biodiversitĂ© taxonomique ordinaire des peuplements forestiers. Rapide et simple Ă utiliser, il est basĂ© sur lâestimation indirecte de la biodiversitĂ© au travers de lâĂ©valuation de la capacitĂ© dâaccueil en espĂšces et en communautĂ©s, Ă lâĂ©chelle du peuplement forestier. Il consiste Ă apprĂ©cier un ensemble de dix facteurs parmi ceux qui sont habituellement reconnus comme les plus favorables Ă la diversitĂ© interne des peuplements. Un score de 0, 2 ou 5 est donnĂ© sur le terrain Ă chacun des facteurs selon une Ă©chelle de valeurs seuils et leur somme donne lâIBP. LâIBP est adaptĂ© Ă toutes les forĂȘts des domaines atlantique et continental. Lâextension Ă la rĂ©gion mĂ©diterranĂ©enne est Ă lâĂ©tude depuis 2009. Le domaine dâutilisation de lâIBP « mĂ©diterranĂ©e » a Ă©tĂ© prĂ©cisĂ©, tant au niveau gĂ©ographique quâau niveau des formations vĂ©gĂ©tales concernĂ©es. Les facteurs et les seuils ont Ă©tĂ© revus pour tenir compte des caractĂ©ristiques des forĂȘts mĂ©diterranĂ©ennes. La problĂ©matique des incendies est Ă©galement Ă©tudiĂ©e Ă travers les relations entre la biodiversitĂ© taxonomique et les feux de forĂȘt, car la forĂȘt mĂ©diterranĂ©enne est particuliĂšrement concernĂ©e
Open Charm Enhancement in Pb+Pb Collisions at SPS
The statistical coalescence model for the production of open and hidden charm
is considered within the canonical ensemble formulation. The data for the
J/\psi multiplicity in Pb+Pb collisions at 158 A GeV are used for the model
prediction of the open charm yield. We find a strong enhancement of the open
charm production, by a factor of about 2--4, over the standard hard-collision
model extrapolation from nucleon-nucleon to nucleus-nucleus collisions. A
possible mechanism of the open charm enhancement in A+A collisions at the SPS
energies is proposed.Comment: 4 pages, Late
Open and Hidden Charm Production in Heavy Ion Collisions at Ultrarelativistic Energies
We consider the production of the open charm and J/psi mesons in heavy ion
collisions at BNL RHIC. We discuss several recently developed pictures for
J/psi production and argue that a measurement at RHIC energies is crucial for
disentangling these different descriptions.Comment: 19 pages, Latex, 5 PS-figures. v3: Fig.6 is adde
Charmonium Suppression by Comover Scattering in Pb+Pb Collisions
The first reports of and production from experiment NA50 at
the CERN SPS are compared to predictions based on a hadronic model of
charmonium suppression. Data on centrality dependence and total cross sections
are in good accord with these predictions.Comment: 9 pages, latex, 6 figures, epsf, figure added and text modified to
clarify result
The High E_T Drop of J/psi to Drell-Yan Ratio from the Statistical c anti-c Coalescence Model
The dependence of the J/psi yield on the transverse energy E_T in heavy ion
collisions is considered within the statistical c anti-c coalescence model. The
model fits the NA50 data for Pb+Pb collisions at the CERN SPS even in the
high-E_T region (E_T > 100 GeV). Here E_T-fluctuations and E_T-losses in the
dimuon event sample naturally create the celebrated drop in the J/psi to
Drell-Yan ratio.Comment: 14 pages, REVTeX, 1 PS-figure. v2: References are corrected and
update
Millikelvin measurements of permittivity and loss tangent of lithium niobate
Lithium Niobate is an electro-optic material with many applications in
microwave signal processing, communication, quantum sensing, and quantum
computing. In this letter, we present findings on evaluating the complex
electromagnetic permittivity of lithium niobate at millikelvin temperatures.
Measurements are carried out using a resonant-type method with a
superconducting radio-frequency (SRF) cavity operating at 7 GHz and designed to
characterize anisotropic dielectrics. The relative permittivity tensor and loss
tangent are measured at 50 mK with unprecedented accuracy.Comment: 5 pages, 4 figure
Direct observation of homogeneous cavitation in nanopores
We report on the evaporation of hexane from porous alumina and silicon
membranes. These membranes contain billions of independent nanopores tailored
to an ink-bottle shape, where a cavity several tens of nanometers in diameter
is separated from the bulk vapor by a constriction. For alumina membranes with
narrow enough constrictions, we demonstrate that cavity evaporation proceeds by
cavitation. Measurements of the pressure dependence of the cavitation rate
follow the predictions of the bulk, homogeneous, classical nucleation theory,
definitively establishing the relevance of homogeneous cavitation as an
evaporation mechanism in mesoporous materials. Our results imply that porous
alumina membranes are a promising new system to study liquids in a deeply
metastable state.Comment: 14 pages , 4 figures. Source files also contain Supplemental Material
(Doebele_HomogeneousCavitationMembranes_SM.pdf
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