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1.
Food Chem ; 383: 132364, 2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-35193091

RESUMO

Food product nutritional and sensory characteristics are often deeply linked to its territory of origin; therefore, its authentication by means of elemental composition becomes crucial for traceability and fighting food fraud. This study aims to establish a fast and reproducible procedure for origin and quality assessment of Sicilian tomato fruits, including PGI "Pomodoro di Pachino", by using the X-ray fluorescence (XRF) technique. Measurements were performed on different parts of PGI Pachino tomatoes belonging to the same production lot. Principal Component and Cluster Analyses show that the samples cluster accordingly with the production lot, disentangling the different parts of the fruit. This procedure, which uses XRF yield elemental pattern and statistical analysis, establishes a solid basis for characterizing elemental profiles by a fast XRF in-situ campaign, supporting the traceability system. The reliability of XRF results was confirmed by comparing elemental concentrations with ICP-MS measurements, performed for comparison, and tomato literature values.


Assuntos
Frutas , Solanum lycopersicum , Estudos de Viabilidade , Reprodutibilidade dos Testes
2.
Radiat Prot Dosimetry ; 180(1-4): 115-119, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29177426

RESUMO

The neutrons for science (NFS) facility is a component of SPIRAL-2, the new superconducting linear accelerator built at GANIL in Caen (France). The proton and deuteron beams delivered by the accelerator will allow producing intense neutron fields in the 100 keV-40 MeV energy range. Continuous and quasi-mono-kinetic energy spectra, respectively, will be available at NFS, produced by the interaction of a deuteron beam on a thick Be converter and by the 7Li(p,n) reaction on thin converter. The pulsed neutron beam, with a flux up to two orders of magnitude higher than those of other existing time-of-flight facilities, will open new opportunities of experiments in fundamental research as well as in nuclear data measurements. In addition to the neutron beam, irradiation stations for neutron-, proton- and deuteron-induced reactions will be available for cross-sections measurements and for the irradiation of electronic devices or biological cells. NFS, whose first experiment is foreseen in 2018, will be a very powerful tool for physics, fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors.


Assuntos
Deutério/análise , Desenho de Equipamento , Lítio/química , Nêutrons , Aceleradores de Partículas/instrumentação , Prótons , Simulação por Computador , Doses de Radiação
3.
Phys Rev Lett ; 118(22): 222501, 2017 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-28621970

RESUMO

Fast-neutron-induced fission of ^{238}U at an energy just above the fission threshold is studied with a novel technique which involves the coupling of a high-efficiency γ-ray spectrometer (MINIBALL) to an inverse-kinematics neutron source (LICORNE) to extract charge yields of fission fragments via γ-γ coincidence spectroscopy. Experimental data and fission models are compared and found to be in reasonable agreement for many nuclei; however, significant discrepancies of up to 600% are observed, particularly for isotopes of Sn and Mo. This indicates that these models significantly overestimate the standard 1 fission mode and suggests that spherical shell effects in the nascent fission fragments are less important for low-energy fast-neutron-induced fission than for thermal neutron-induced fission. This has consequences for understanding and modeling the fission process, for experimental nuclear structure studies of the most neutron-rich nuclei, for future energy applications (e.g., Generation IV reactors which use fast-neutron spectra), and for the reactor antineutrino anomaly.

4.
Talanta ; 106: 39-44, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23598093

RESUMO

The French Atomic Energy Commission has carried out several experiments for the study of minor-actinide transmutation processes in high intensity thermal neutron flux. In this context a Cm sample enriched in (248)Cm (∼97%) was irradiated in a thermal neutron flux at the High Flux Reactor (HFR) of the Laue-Langevin Institute (ILL). The precise and accurate determination of Cf isotope ratios and of (249)Bk/(248)Cm and (249)Cf/(248)Cm elemental ratios in the (248)Cm irradiated sample is crucial for the calculation of actinide neutron capture cross-sections. This work describes an analytical procedure for the separation and the isotope ratio measurement of Bk and Cf in the irradiated sample. The Bk and Cf separation is based on a lanthanides separation protocol previously developed by the laboratory. Well-defined retention times for Bk and Cf were obtained by coupling the Ionic Chromatography (IC) with an ICP-QMS. All conditions of element separation by IC and the different steps of the analytical protocol in order to obtain the isotopic and elemental ratios are presented. Relative uncertainties of Cf isotopic ratios range from 0.3% to 0.5% and the uncertainty of the (249)Bk/(248)Cm and (249)Cf/(248)Cm elemental ratios are respectively 6.1% and 3.2%. This level of uncertainty for both isotopic and elemental ratios is in perfect agreement with the requirement for transmutation studies.

5.
Phys Rev Lett ; 111(24): 242502, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24483647

RESUMO

Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A≳140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular, the fission fragment yields determine the creation of 110≲A≲170 nuclei. Here, we apply a new scission-point model, called SPY, to derive the fission fragment distribution (FFD) of all relevant neutron-rich, fissioning nuclei. The model predicts a doubly asymmetric FFD in the abundant A≃278 mass region that is responsible for the final recycling of the fissioning material. Using ejecta conditions based on relativistic NS merger calculations, we show that this specific FFD leads to a production of the A≃165 rare-earth peak that is nicely compatible with the abundance patterns in the Sun and metal-poor stars. This new finding further strengthens the case of NS mergers as possible dominant origin of r nuclei with A≳140.

6.
Fam Med ; 22(1): 38-41, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2303181

RESUMO

A majority of patients with mental or emotional problems are seen in the general medical sector first, but physicians often report that they do not have the time or skills for dealing with these patients. This study focuses on physicians' and psychologists' beliefs about the components of making a successful referral. Interviews with family physicians and psychologists revealed that physician visits before and after referrals, good communication between the physician and the psychologist, physician knowledge about psychotherapy, third-party insurance coverage, and a holistic approach to the patient were considered important components of a successful referral. Physicians believed that patients' income and psychologist experience were less important than did psychologists, but physicians felt that involving the family was more important than psychologists. Both groups generally agreed about specific problems and their relationships to a successful referral. This survey identified issues useful to providers attempting to care for patients with psychological problems by the referral process.


Assuntos
Médicos de Família , Psicologia Clínica , Psicoterapia , Encaminhamento e Consulta , Atitude do Pessoal de Saúde , Comportamento Cooperativo , Medicina de Família e Comunidade , Feminino , Humanos , Relações Interprofissionais , Masculino , Relações Médico-Paciente , Relações Profissional-Paciente
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