800 research outputs found
Characterization of a defective PbWO4 crystal cut along the a-c crystallographic plane: structural assessment and a novel photoelastic stress analysis
Among scintillators, the PWO is one of the most widely used, for instance in
CMS calorimeter at CERN and PANDA project. Crystallographic structure and
chemical composition as well as residual stress condition, are indicators of
homogeneity and good quality of the crystal. In this paper, structural
characterization of a defective PbWO4 (PWO) crystal has been performed by X-ray
Diffraction (XRD), Energy Dispersive Spectroscopy (EDS) and Photoelasticity in
the unusual a-c crystallographic plane. XRD and EDS analysis have been used to
investigate crystallographic orientation and chemical composition, while stress
distribution, which indicates macroscopic inhomogeneities and defects, has been
obtained by photoelastic approaches, in Conoscopic and Sphenoscopic
configuration. Since the sample is cut along the a-c crystallographic plane, a
new method is proposed for the interpretation of the fringe pattern. The
structural analysis has detected odds from the nominal lattice dimension, which
can be attributed to the strong presence of Pb and W. A strong inhomogeneity
over the crystal sample has been revealed by the photoelastic inspection. The
results give reliability to the proposed procedure which is exploitable in
crystals with other structures.Comment: 18 pages, 10 figures, revised versio
Sistema per l'acquisizione, l'archiviazione e la visualizzazione dei dati meteo della rete etnea
THERMAL IMAGING OF ERTA 'ALE LAVA LAKE
The project ''Sviluppo di sistemi di monitoraggio'' (Dipartimento di Protezione Civile di Regione Sicilia, INGV Catania Section, Italy), the Leverhulme Trust, the BBC, and the Ethiopian Air Force
Further constraints on the optical transmission spectrum of HAT-P-1b
We report on novel observations of HAT-P-1 aimed at constraining the optical
transmission spectrum of the atmosphere of its transiting Hot-Jupiter
exoplanet. Ground-based differential spectrophotometry was performed over two
transit windows using the DOLORES spectrograph at the Telescopio Nazionale
Galileo (TNG). Our measurements imply an average planet to star radius ratio
equal to =(0.11590.0005). This result is consistent
with the value obtained from recent near infrared measurements of this object
but differs from previously reported optical measurements being lower by around
4.4 exoplanet scale heights. Analyzing the data over 5 different spectral bins
600\AA wide we observed a single peaked spectrum (3.7 level)
with a blue cut-off corresponding to the blue edge of the broad absorption wing
of sodium and an increased absorption in the region in between 6180-7400\AA. We
also infer that the width of the broad absorption wings due to alkali metals is
likely narrower than the one implied by solar abundance clear atmospheric
models. We interpret the result as evidence that HAT-P-1b has a partially clear
atmosphere at optical wavelengths with a more modest contribution from an
optical absorber than previously reported.Comment: Accepted by Ap
The capital accumulation ratio as an indicator of retirement adequacy
The relationship between meeting the Capital Accumulation Ratio Guideline and retirement adequacy was investigated. About 63% of the households had a consistent relationship between meeting the 25% ratio guideline and being adequately prepared for retirement, with 46% of households both meeting the 25% ratio guideline and being prepared for retirement and 17% not meeting the guideline and not being adequately prepared for retirement. However, 37% of households did not have a consistent relationship. Meeting the 25% ratio guideline does not appear to be an accurate indicator of retirement adequacy. The 25% guideline was a better indicator than the 50% guideline.Includes bibliographical references
Factors related to meeting the capital accumulation ratio guideline
The capital accumulation ratio, investment assets divided by net worth, has been proposed as a useful indicator of financial health. Various experts recommend a minimum value of 25% to 50% for the ratio. When certificates of deposit are not counted as investment assets, 56% of U.S. households meet the 25% guideline and only 40% meet the 50% guideline. In a multivariate logistic regression, education, income, number of years until retirement, overspending, and financial risk tolerance are positively related to meeting the guidelines.Includes bibliographical references
Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis
Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis
Progetto di una banca dati multidisciplinare: il progetto europeo VOLUME come caso di studio
Il presente lavoro si pone come obiettivo la realizzazione di una banca dati multi-parametrica in grado
di archiviare diverse tipologie di dato strumentale. Il sistema proposto, accessibile dal portale dellâINGV
della sezione di Catania al link âaltre INGV-CTâ del menĂš âBanche datiâ, studiato e collaudato allâinterno
del progetto europeo VOLUME (http://www.volume-project.net/), consente la fruizione dei dati messi a
disposizione dalle diverse unitĂ funzionali dellâINGV della sezione di Catania coinvolte nel progetto. I dati,
disponibili ai partner del progetto, sono accessibili previa registrazione e successiva validazione dellâutente.
Lâobiettivo principale di tale progetto è quello di studiare le dinamiche vulcaniche in modo da
identificare e caratterizzare fenomeni che possano essere interpretati come possibili precursori di eruzioni.
Per perseguire tale obiettivo occorre analizzare ed integrare diverse tipologie di misure, da quelle geofisiche
a quelle geochimiche, con il fine di raggiungere una migliore comprensione dei processi in atto allâinterno
delle aree caratterizzate da vulcanismo attivo. Sebbene i dati archiviati siano relativi al solo vulcano Etna ed
il periodo analizzato è relativo agli anni 2002-2003 , il sistema proposto può essere impiegato per la gestione
di dati relativi ad altri vulcani e attinenti a qualsiasi intervallo temporale. Il sistema è stato realizzato in modo
da fornire una interfaccia web user friendly che permetta agli utenti la navigazione, la visualizzazione e il
download dei dati memorizzati allâinterno della banca dati.
Nei paragrafi successivi verrĂ presentata una panoramica delle funzionalitĂ implementate per la
navigazione del database. In particolare, i dati trattati nel presente report sono stati prodotti e forniti dalle
unitĂ funzionali dellâINGV della sezione di Catania (http://www.ct.ingv.it) che hanno partecipato al progetto
VOLUME:
⢠Unità Funzionale Sismologia;
⢠Unità Funzionale Vulcanologia e Geochimica;
⢠Unità Funzionale Gravimetria e Magnetismo;
⢠Unità Funzionale Deformazione e Geodesia
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