Dynamical mean-field approach to materials with strong electronic correlations

We review recent results on the properties of materials with correlated electrons obtained within the LDA+DMFT approach, a combination of a conventional band structure approach based on the local density approximation (LDA) and the dynamical mean-field theory (DMFT). The application to four outstanding problems in this field is discussed: (i) we compute the full valence band structure of the charge-transfer insulator NiO by explicitly including the p-d hybridization, (ii) we explain the origin for the simultaneously occuring metal-insulator transition and collapse of the magnetic moment in MnO and Fe2O3, (iii) we describe a novel GGA+DMFT scheme in terms of plane-wave pseudopotentials which allows us to compute the orbital order and cooperative Jahn-Teller distortion in KCuF3 and LaMnO3, and (iv) we provide a general explanation for the appearance of kinks in the effective dispersion of correlated electrons in systems with a pronounced three-peak spectral function without having to resort to the coupling of electrons to bosonic excitations. These results provide a considerable progress in the fully microscopic investigations of correlated electron materials.Comment: 24 pages, 14 figures, final version, submitted to Eur. Phys. J. for publication in the Special Topics volume "Cooperative Phenomena in Solids: Metal-Insulator Transitions and Ordering of Microscopic Degrees of Freedom

Lesson learned from the International Registry of Acute Aortic Dissection (IRAD)

Acute aortic dissection (AAD) is a life-threatening disorder that is challenging to diagnose and with defined optimal therapies and outcomes. It is associated with high morbidity and mortality rates, in spite of new management approaches developed over the past few decades. In this article we review lessons learned from the 20-year IRADRegistry experience and its nearly 100 publications. The International Registry of Acute Aortic Dissection (IRAD) is an ongoing registry, which was established in 1996 with the aim to collect data and provide information on this rare disease in order to provide better decision making on clinical practice and surgical management. Acute aortic dissection, including intramural hematoma, is defined as onset of symptoms within 14 days to hospital admission. After 20 years of enrollment, more than 8000 patients with AAD have been collected worldwide, roughly two-thirds with type Aand one-third with type B. Data shows trend for a reduced overall in hospital mortality over the years, in particular for those operated on for type AAAD, due to the improvement in operative technologies, organ perfusion and surgeons taking on even high-risk patients. In contrast, for type B AADendovascular repair has been more frequently adopted in recent years but without a significant demonstrable reduction of in hospital mortality, although an increased survival rate at 5 years was observed. Data suggest an increase in surgical intervention treatment for both type Aand B AAD, particularly in B due to expansion of endovascular treatment. While expanded surgical repair for type Ahas shown a trend for a better outcome, this was not observed for type B patients. In addition, debate continues about endovascular treatment of uncomplicated type B and IMH

The IRAD classification system for characterizing survival after aortic dissection

Background: The classification of aortic dissection into acute (30 days). Overall survival was progressively lower through the 4 time periods. Conclusions: This IRAD classification system can provide clinicians with a more robust method of characterizing survival after aortic dissection over time than previous methods. This system will be useful for treating patients, counseling patients and families, and studying new diagnostic and treatment methods

Le situazioni giuridiche soggettive

Il contributo analizza le principali categorie e specie di diritti soggettivi individuali, nonchè i diritti di categoria, diffusi e collettivi. L'analisi ha poi ad oggetto i diritti procedimentali e processuali nei confronti della pubblica amministrazione, individuando al contempo gli obblighi dei cittadini europei e le situazioni giuridiche soggettive dei pubblici poteri della comunità europea. Si giunge per tale via a tracciare il difficile cammino delle situazioni giuridiche soggettive nazionali verso l’integrazione europea

Le situazioni giuridiche soggettive

Il contributo analizza le principali categorie e specie di diritti soggettivi individuali, nonchè i diritti di categoria, diffusi e collettivi. L'analisi ha poi ad oggetto i diritti procedimentali e processuali nei confronti della pubblica amministrazione, individuando al contempo gli obblighi dei cittadini europei e le situazioni giuridiche soggettive dei pubblici poteri della comunità europea. Si giunge per tale via a tracciare il difficile cammino delle situazioni giuridiche soggettive nazionali verso l’integrazione europea

The EEE MRPC telescopes as tracking tools to monitor building stability with cosmic muons

This paper discusses the possibility to employ the Multi-gap Resistive Plate Chambers (MRPC) of the Extreme Energy Events (EEE) Project as muon tracking detectors to monitor the long term stability of civil buildings and structures when used in conjunction with additional detectors, to reconstruct the average direction of the cosmic muon tracks passing through both devices and any small variation over long time acquisition periods. The performance of such setup is discussed and preliminary experimental coincidence results obtained with a 40 7 60 cm2scintillator detector operated in the same building with one of the EEE telescopes, at about 15 m vertical distance from it, are presented. Simple Monte Carlo and GEANT simulations were also carried out to evaluate typical acceptance values for the operating conditions employed so far, to extrapolate to other geometrical configurations, and to evaluate multiple scattering effects

Strategies to reduce the environmental impact in the MRPC array of the EEE experiment

The Extreme Energy Events (EEE) Project employs Multi-gap Resistive Plate Chambers (MRPCs) for studying the secondary cosmic ray muons in Extensive Air Showers. The array consists of about 60 tracking detectors, sparse on Italian territory and at CERN. The MRPCs are flowed with a gas mixture based on C2H2F4 and SF6, both of which are fluorinated greenhouse gases with a high environmental impact on the atmosphere. Due to the restrictions imposed by the European Union, these gases are being phased out of production and their cost is largely increasing. The EEE Collaboration started a campaign to reduce the gas emission from its array with the aim of containing costs and decreasing the experiment global warming impact. One method is to reduce the gas rate in each EEE detector. Another is to develop a gas recirculation system, whose prototype has been installed at one of the EEE stations located at CERN. Jointly a parallel strategy is focused on searching for environmental friendly gas mixtures which are able to substitute the standard mixture without affecting the MRPC performance. An overview and the first results are presented here.The Extreme Energy Events (EEE) Project employs Multi-gap Resistive Plate Chamber (MRPC) for studying the secondary cosmic ray muons in Extensive Air Showers. The array consists of about 60 tracking detectors, sparse on Italian territory and at CERN. The MRPCs are flowed with a gas mixture based on $C_2H_2F_4$ and $SF_6$, both of which are fluorinated greenhouse gases with a high environmental impact on the atmosphere. Due to the restrictions imposed by the European Union, these gases are being phased out of production and their cost is largely increasing. The EEE Collaboration started a campaign to reduce the gas emission from its array with the aim of containing costs and decreasing the experiment global warming impact. One method is to reduce the gas rate in each EEE detector. Another is to develop a gas recirculation system, whose a first prototype has been installed at one of the EEE stations located at CERN. Jointly a parallel strategy is focused on searching for environmental friendly gas mixtures which are able to substitute the standard mixture without affecting the MRPC performance. An overview and first results are presented here.The Extreme Energy Events (EEE) Project employs Multi-gap Resistive Plate Chambers (MRPCs) for studying the secondary cosmic ray muons in Extensive Air Showers. The array consists of about 60 tracking detectors, sparse on Italian territory and at CERN. The MRPCs are flowed with a gas mixture based on C2H2F4 and SF6, both of which are fluorinated greenhouse gases with a high environmental impact on the atmosphere. Due to the restrictions imposed by the European Union, these gases are being phased out of production and their cost is largely increasing. The EEE Collaboration started a campaign to reduce the gas emission from its array with the aim of containing costs and decreasing the experiment global warming impact. One method is to reduce the gas rate in each EEE detector. Another is to develop a gas recirculation system, whose prototype has been installed at one of the EEE stations located at CERN. Jointly a parallel strategy is focused on searching for environmental friendly gas mixtures which are able to substitute the standard mixture without affecting the MRPC performance. An overview and the first results are presented here

MRPC Telescope Simulation for the Extreme Energy Events Experiment

A simulation tool based on GEMC framework to describe the MRPC telescope of the Extreme Energy Events (EEE) Project is presented. The EEE experiment is mainly devoted to the study of the secondary cosmic muons by using MRPC telescope distributed in high schools and research centres in Italy and at CERN. This takes into account the muon interactions with EEE telescopes and the structures surrounding the experimental apparata; it consists of a dedicated event generator producing realistic muon distribution and a detailed geometry description of the detector. Microscopic behaviour of MRPCs has been included to produce experimental-like data. A method to estimate the chamber efficiency directly from data has been implemented and tested by comparing the experimental and simulated polar angle distribution of muons.A simulation tool based on GEMC framework to describe the MRPC telescope of the Extreme Energy Events (EEE) Project is presented. The EEE experiment is mainly devoted to the study of the secondary cosmic muons by using MRPC telescope distributed in high schools and research centres in Italy and at CERN. This takes into account the muon interactions with EEE telescopes and the structures surrounding the experimental apparata; it consists of a dedicated event generator producing realistic muon distribution and a detailed geometry description of the detector. Microscopic behaviour of MRPCs has been included to produce experimental-like data. A method to estimate the chamber effciency directly from data has been implemented and tested by comparing the experimental and simulated polar angle distribution of muons

A simulation tool for MRPC telescopes of the EEE project

The Extreme Energy Events (EEE) Project is mainly devoted to the study of the secondary cosmic ray radiation by using muon tracker telescopes made of three Multigap Resistive Plate Chambers (MRPC) each. The experiment consists of a telescope network mainly distributed across Italy, hosted in different building structures pertaining to high schools, universities and research centers. Therefore, the possibility to take into account the effects of these structures on collected data is important for the large physics programme of the project. A simulation tool, based on GEANT4 and using GEMC framework, has been implemented to take into account the muon interaction with EEE telescopes and to estimate the effects on data of the structures surrounding the experimental apparata.A dedicated event generator producing realistic muon distributions, detailed geometry and microscopic behavior of MRPCs have been included to produce experimental-like data. The comparison between simulated and experimental data, and the estimation of detector resolutions is here presented and discussed