252 research outputs found
Crystalline color superconductors
Inhomogeneous superconductors and inhomogeneous superfluids appear in a
variety of contexts including quark matter at extreme densities, fermionic
systems of cold atoms, type-II cuprates, and organic superconductors. In the
present review the focus is on properties of quark matter at high baryonic
density, which may exist in the interior of compact stars. The conditions
realized in these stellar objects tend to disfavor standard symmetric BCS
pairing and may favor an inhomogeneous color superconducting phase. The
properties of inhomogeneous color superconductors are discussed in detail and
in particular of crystalline color superconductors. The possible astrophysical
signatures associated with the presence of crystalline color superconducting
phases within the core of compact stars are also reviewed.Comment: Added 3 figures, added section II F, added section with conclusions.
Several references added. Improved the quality of the presentation and
removed various typos. Almost matches the version accepted for publication of
Reviews of Modern Physic
Evaluating the phase diagram of superconductors with asymmetric spin populations
The phase diagram of a non-relativistic fermionic system with imbalanced
state populations interacting via a short-range S-wave attractive interaction
is analyzed in the mean field approximation. We determine the energetically
favored state for different values of the mismatch between the two Fermi
spheres in the weak and strong coupling regime considering both homogeneous and
non-homogeneous superconductive states. We find that the homogeneous
superconductive phase persists for values of the population imbalance that
increase with increasing coupling strength. In the strong coupling regime and
for large population differences the energetically stable homogeneous phase is
characterized by one gapless mode. We also find that the inhomogeneous
superconductive phase characterized by the condensate is energetically favored in a range of values
of the chemical potential mismatch that shrinks to zero in the strong coupling
regime.Comment: 9 pages, 5 figure
Neutrino emission from compact stars and inhomogeneous color superconductivity
We discuss specific heat and neutrino emissivity due to direct Urca processes
for quark matter in the color superconductive Larkin-Ovchinnikov-Fulde-Ferrell
(LOFF) phase of Quantum-Chromodynamics. We assume that the three light quarks
are in a color and electrically neutral state and interact by a four
fermion Nambu-Jona Lasinio coupling. We study a LOFF state characterized by a
single plane wave for each pairing. From the evaluation of neutrino emissivity
and fermionic specific heat, the cooling rate of simplified models of compact
stars with a quark core in the LOFF state is estimated.Comment: 16 pages, 5 figures, revtex4 style. Version accepted for publication
in Phys. Rev.
La disclosure volontaria del modello di business nel prospetto informativo di quotazione: un’analisi comparative
How do companies to be listed actually deal with voluntary disclosure of their business model? Is it true that firms with greater knowledge-based resources and technological innovation endowments have a lower propensity to adopt fully open communication behaviors? This paper aims to identify the voluntary disclosure policies adopted by three Italian companies in their Initial Public Offering (IPO) prospectuses in order to investigate whether any differences may depend on the type of innovation underlying each business model. A series of interviews conducted with the top management made it possible to understand more deeply the business model of each company. Further, a content analysis has been developed to compute a measure of disclosure and to point out the strategic concepts and their relevance. We provide evidence that companies with a business model based on technology-push innovation have a lower propensity to the full disclosure of their intangible components, particularly of those mainly based on knowledge as these are also invisible. Our study adds to the literature of business and financial reporting by focusing on a new object of inquiry, that is the business model. The business model plays an important role in allowing external actors to understand a company’s value, thus companies’ strategic communication should be shaped accordingly. The results suggest the need to address the issue of voluntary disclosure of the business model by first distinguishing “visible” intangible resources from those that are “invisible” (both to financial and competitive markets). The study aims to make a contribution to the ongoing debate on business and financial reporting practice
Victims of Violence in Accident & Emergency: Reporting Survey of Eleven Emergency Structures Out of Eighteen
Sexual violence is a widespread and common phenomenon in our society, which unfortunately often goes unreported or undetected: a hidden "iceberg" of great dimension. Often the victims arrive to our emergency department where the sanitary workers are not prepared to help them professionally. By this work the authors want to evaluate health workers true understanding of the "problem of violence"; their human and professional capacity to manage it; their capacity to create and promote sensitisation and training programmes for professionals working in the field; and the ability to design and implement protocols and procedures to be utilized when managing victims of violence by a questionnaire compiled and distributed to health professionals working in the critical areas (A&E and DEA) in the region Lazio
Life-threatening acute myocardial infarction due to left main dissection during radiofrequency transcatheter ablation of atrial tachycardia
May Renal Resistive Index Be an Early Predictive Tool of Postoperative Complications in Major Surgery? Preliminary Results
Background.Patients who undergo high-risk surgery represent a large amount of post-operative ICU-admissions. These patients are at high risk of experiencing postoperative complications. Renal Resistive Index was found to be related with renal dysfunction, hypertension, and posttraumatic hemorrhagic shock, probably due to vasoconstriction. We explored whether Renal Resistive Index (RRI), measured after awakening from general anesthesia, could have any relationship with postoperative complications.Methods.In our observational, stratified dual-center trial, we enrolled patients who underwent general anesthesia for high-risk major surgery. After awakening in recovery room (or during awakening period in subjects submitted to cardiac surgery) we measured RRI by echo-color-Doppler method. Primary endpoint was the association of altered RRI (>0.70) and outcome during the first postoperative week.Results.205 patients were enrolled: 60 (29.3%) showed RRI > 0.70. The total rate of adverse event was 27 (18.6%) in RRI ≤ 0.7 group and 19 (31.7%) in RRI > 0.7 group (P=0.042). Significant correlation between RRI > 0.70 and complications resulted in pneumonia (P=0.016), septic shock (P=0.003), and acute renal failure (P=0.001) subgroups. Patients with RRI > 0.7 showed longer ICU stay (P=0.001) and lasting of mechanical ventilation (P=0.004). These results were confirmed in cardiothoracic surgery subgroup. RRI > 0.7 duplicates triplicates the risk of complications, both in general (OR 2.03 93 95% CI 1.02–4.02,P=0.044) and in cardiothoracic (OR 2.62 95% CI 1.11–6.16,P=0.027) population. Furthermore, we found RRI > 0.70 was associated with a triplicate risk of postoperative septic shock (OR 3.04, CI 95% 1.5–7.01;P=0.002).</jats:p
Non-Destructive Multi-Analytical Approach to Study the Pigments of Wall Painting Fragments Reused in Mortars from the Archaeological Site of Pompeii (Italy)
During the excavations carried out in Via di Mercurio (Regio VI, 9, 3) in Pompeii, in 2015, some red, green, black, and brown wall painting fragments were found in the preparatory layer of an ancient pavement which was probably built after the 62 AD earthquake. These fragments, derived from the rubble, were used as coarse aggregate to prepare the mortar for building the pavement. The wall painting fragments are exceptionally well preserved, which is an uncommon occurrence in the city of Pompeii. However, as they were enclosed in the mortar, the wall painting fragments were protected from the high temperatures (probably ranging between 180 ◦C and 380 ◦C) produced by the eruption in 79 AD. The pigmented outer surface of each sample was analyzed using a non-destructive multi-analytical approach, by combining spectrophotometric colorimetry and portable X-ray fluorescence with micro-Raman spectroscopy. The compositional characterization of the samples revealed the presence of cuprorivaite, goethite, and celadonite in the green pigments; hematite in the red pigments; goethite in the brown pigment; and charcoal in the black pigment. These data probably provide us with the most "faithful picture" of the various red, green, black, and brown pigments used in Pompeii prior to the 79 AD eruptio
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