681 research outputs found
Development and tests of a new prototype detector for the XAFS beamline at Elettra Synchrotron in Trieste
The XAFS beamline at Elettra Synchrotron in Trieste combines X-ray absorption
spectroscopy and X-ray diffraction to provide chemically specific structural
information of materials. It operates in the energy range 2.4-27 keV by using a
silicon double reflection Bragg monochromator. The fluorescence measurement is
performed in place of the absorption spectroscopy when the sample transparency
is too low for transmission measurements or the element to study is too diluted
in the sample. We report on the development and on the preliminary tests of a
new prototype detector based on Silicon Drift Detectors technology and the
SIRIO ultra low noise front-end ASIC. The new system will be able to reduce
drastically the time needed to perform fluorescence measurements, while keeping
a short dead time and maintaining an adequate energy resolution to perform
spectroscopy. The custom-made silicon sensor and the electronics are designed
specifically for the beamline requirements.Comment: Proceeding of the 6YRM 12th-14th Oct 2015 - L'Aquila (Italy).
Accepted for publication on Journal of Physics: Conference Serie
Correlations between isospin dynamics and Intermediate Mass Fragments emission time scales: a probe for the symmetry energy in asymmetric nuclear matter
We show new data from the Ni+Sn and Ni+Sn
reactions studied in direct kinematics with the CHIMERA detector at INFN-LNS
and compared with the reverse kinematics reactions at the same incident beam
energy (35 A MeV). Analyzing the data with the method of relative velocity
correlations, fragments coming from statistical decay of an excited
projectile-like (PLF) or target-like (TLF) fragments are discriminated from the
ones coming from dynamical emission in the early stages of the reaction. By
comparing data of the reverse kinematics experiment with a stochastic mean
field (SMF) + GEMINI calculations our results show that observables from neck
fragmentation mechanism add valuable constraints on the density dependence of
symmetry energy. An indication is found for a moderately stiff symmetry energy
potential term of EOS.Comment: Talk given by E. De Filippo at the 11th International Conference on
Nucleus-Nucleus Collisions (NN2012), San Antonio, Texas, USA, May 27-June 1,
2012. To appear in the NN2012 Proceedings in Journal of Physics: Conference
Series (JPCS
Intravesical administration of combined hyaluronic acid (HA) and chondroitin sulfate (CS) for the treatment of female recurrent urinary tract infections: a European multicentre nested case-control study.
Published onlineJournal ArticleMulticenter StudyObservational StudyResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from BMJ Publishing Group via the DOI in this record.OBJECTIVES: To compare the clinical effectiveness of the intravesical administration of combined hyaluronic acid and chondroitin sulfate (HA+CS) versus current standard management in adult women with recurrent urinary tract infections (RUTIs). SETTING: A European Union-based multicentre, retrospective nested case-control study. PARTICIPANTS: 276 adult women treated for RUTIs starting from 2009 to 2013. INTERVENTIONS: Patients treated with either intravesical administration of HA+CS or standard of care (antimicrobial/immunoactive prophylaxis/probiotics/cranberry). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was occurrence of bacteriologically confirmed recurrence within 12 months. Secondary outcomes were time to recurrence, total number of recurrences, health-related quality of life and healthcare resource consumption. Crude and adjusted results for unbalanced characteristics are presented. RESULTS: 181 patients treated with HA+CS and 95 patients treated with standard of care from 7 centres were included. The crude and adjusted ORs (95% CI) for the primary end point were 0.77 (0.46 to 1.28) and 0.51 (0.27 to 0.96), respectively. However, no evidence of improvement in terms of total number of recurrences (incidence rate ratio (95% CI), 0.99 (0.69 to 1.43)) or time to first recurrence was seen (HR (95% CI), 0.99 (0.61 to 1.61)). The benefit of intravesical HA+CS therapy improves when the number of instillations is ≥ 5. CONCLUSIONS: Our results show that bladder instillations of combined HA+CS reduce the risk of bacteriologically confirmed recurrences compared with the current standard management of RUTIs. Total incidence rates and hazard rates were instead non-significantly different between the 2 groups after adjusting for unbalanced factors. In contrast to what happens with antibiotic prophylaxis, the effectiveness of the HA+CS reinstatement therapy improves over time. TRIAL REGISTRATION NUMBER: NCT02016118.This study was funded by an unrestricted grant from the TETI Association—study group for urogenital diseases. Members of the association were involved in the data collection and revised the manuscript
NArCoS: The new hodoscope for neutrons and charged particles
Proper detection of neutrons and charged particles is motivated by the recent efforts to construct new facilities for radioactive ion beams (RIBs) worldwide. Detection of neutrons is an important opportunity to improve our understanding of nuclear spectroscopy and reaction dynamics, with the possibility of constraining theoretical models of the nuclear equation of state (NEoS) and investigating in-medium nuclear interactions. This topic also has important implications in the study of astrophysical objects, such as neutron stars. In this work, the state-of-the-art of Neutron Array for Correlation Studies (NArCoS), a new hodoscope for neutron and charged particles under construction in Catania (INFN), is briefly reviewed
Recent results on the construction of a new correlator for neutrons and charged particles and for FARCOS
With the advent of new facilities for radioactive ion beams it is necessary to develop neutron detection systems integrated with charged-particle ones. The integration of the neutron signal, especially in the case of neutron-rich beams, becomes a mandatory requirement in order to study the property of the nuclear matter in extreme conditions. For this reason, new detectors using new materials have to be built. NArCoS (Neutron ARray for COrrelation Studies) is a project aimed at the design of a new detector based on stack of plastic scintillators, featuring both good energy and angular resolution sensitive both to neutrons and charged particles within the same detection cell. We present in this work new results on the Pulse Shape Discrimination (PSD) capabilities of two very compact detection systems: the 3 x 3 x 3 cm(3) EJ 276+SiPM and the 3 x 3 x 3 cm(3) EJ 276G +SiPM (the latter green shifted version). In addition, we compare new results about the energy calibration and resolution of the FARCOS correlator in the CHIFAR experiment performed at LNS
Isotope correlations as a probe for freeze-out characterization: central 124Sn+64Ni, 112Sn+58Ni collisions
124Sn+64Ni and 112Sn+58Ni reactions at 35 AMeV incident energy were studied
with the forward part of CHIMERA multi-detector. The most central collisions
were selected by means of a multidimensional analysis. The characteristics of
the source formed in the central collisions, as size, temperature and volume,
were inspected. The measured isotopes of light fragments (3 <= Z <=8) were used
to examine isotope yield ratios that provide information on the free neutron to
proton densities.Comment: 4 pages, Contribution to 8th International Conference on
Nucleus-Nucleus Collisions, Moscow 200
Projected Quasi-particle Perturbation theory
The BCS and/or HFB theories are extended by treating the effect of four
quasi-particle states perturbatively. The approach is tested on the pairing
hamiltonian, showing that it combines the advantage of standard perturbation
theory valid at low pairing strength and of non-perturbative approaches
breaking particle number valid at higher pairing strength. Including the
restoration of particle number, further improves the description of pairing
correlation. In the presented test, the agreement between the exact solution
and the combined perturbative + projection is almost perfect. The proposed
method scales friendly when the number of particles increases and provides a
simple alternative to other more complicated approaches
Population and decay of C-12 states
By using the CHIMERA detector, we have measured the gamma-ray and alpha decay width of excited C-12 states important for the carbon production inastrophysical environments. For the first time, we directly observed the gamma-ray decayof the 9.64 MeV level. A gamma-ray decay width larger than previous observations wasobserved for the Hoyle state. In order to explain this enhanced yield we investigatedon the recently proposed population of an Efimov state at 7.458 MeV. The decaycharacteristics of such level are inferred
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