EXPERIMENTAL STUDY OF ISOSPIN SYMMETRY IN N=Z NUCLEI

The Isospin symmetry is one of the first dynamical symmetries identified in nuclear physics. It helps us to simplify the description of a system, in this case the atomic nucleus, a quantum many-body system consisting of two types of fermion, the neutron and the proton. The assumptions of the charge symmetry and the charge independence of the nuclear interaction led to consider neutrons and protons as two different states of the same particle, the nucleon. To account for this, in 1932, Heisenberg introduced a new quantum number, the isotopic spin or Isospin. The concept of the Isospin symmetry neglects the presence of Coulomb interaction inside the atomic nucleus. This interaction breaks the Isospin symmetry, inducing impurities in the nuclear wave function. This is the so called Isospin-mixing phenomenon. In this thesis work the experimental study of the Isospin-mixing phenomenon is approached from two different points of view. On one hand, the characterization of two types of detectors ideal for the Isospin mixing investigation is presented. On the other hand, the experimental determination of the Isospin mixing probability in the nucleus 60Zn is discussed

Chromatographic determination of 12 dyes in meat products by HPLC-UV-DIODE array detection

The use of food dyes in meat is regulated by the current European and non-European legislation, due to several food safety concerns. A reliable method for the quali-quantitative determination of 12 food dyes (Amaranth, Ponceau 4R, Carmine, Ponceau SX, Ponceau 3R, Allura Red AC, Carmoisine, Erythrosine, Sudan I, Sudan II, Sudan III and Sudan IV) in meat products, by high performance liquid chromatography coupled to UV diode array detection is presented. The extraction was accomplished by using acetonitrile, methanol, water, and ammonia, 50:40:9:1 (v/v/v/v) as the solvent and ultrasonic bath. The chromatographic separation was obtained with a C18 RP column eluted by a gradient of acetate buffer/acetonitrile. Good analytical performances characterized this method (Table 1), in terms of selectivity, sensitivity, accuracy and ruggedness. Both method precision (CV% range: 6%-15%) and recovery percentages (range: 86%-105%) resulted in compliance with Decision 2002/657/EC, and the expanded measurement uncertainties, estimated by a bottom-up approach, were in the range 6%-20%. All these results demonstrated that the procedure can be applied successfully for confirmation analyses of commercial meat products. •12 food dyes were determined in meat by new HPLC/UV-DAD method.•The analytical method was fully validated for accurate confirmation analyses.•Method accuracy, sensitivity, selectivity and ruggedness resulted satisfactory

Tritiated Steel Micro-Particles: Computational Dosimetry and Prediction of Radiation-Induced DNA Damage for In Vitro Cell Culture Exposures.

Biological effects of radioactive particles can be experimentally investigated in vitro as a function of particle concentration, specific activity and exposure time. However, a careful dosimetric analysis is needed to elucidate the role of radiation emitted by radioactive products in inducing cyto- and geno-toxicity: the quantification of radiation dose is essential to eventually inform dose-risk correlations. This is even more fundamental when radioactive particles are short-range emitters and when they have a chemical speciation that might further concur to the heterogeneity of energy deposition at the cellular and sub-cellular level. To this aim, we need to use computational models. In this work, we made use of a Monte Carlo radiation transport code to perform a computational dosimetric reconstruction for in vitro exposure of cells to tritiated steel particles of micrometric size. Particles of this kind have been identified as worth of attention in nuclear power industry and research: tritium easily permeates in steel elements of nuclear reactor machinery, and mechanical operations on these elements (e.g., sawing) during decommissioning of old facilities can result in particle dispersion, leading to human exposure via inhalation. Considering the software replica of a representative in vitro setup to study the effect of such particles, we therefore modelled the radiation field due to the presence of particles in proximity of cells. We developed a computational approach to reconstruct the dose range to individual cell nuclei in contact with a particle, as well as the fraction of "hit" cells and the average dose for the whole cell population, as a function of particle concentration in the culture medium. The dosimetric analysis also provided the basis to make predictions on tritium-induced DNA damage: we estimated the dose-dependent expected yield of DNA double strand breaks due to tritiated steel particle radiation, as an indicator of their expected biological effectiveness

Isospin mixing in Zr 80: from finite to zero temperature

S. Ceruti et al.; 5 págs.; 4 figs.; PACS numbers: 24.30.Cz, 24.60.Dr, 24.80.+y, 25.70.GhThe isospin mixing was deduced in the compound nucleus Zr80 at an excitation energy of E∗=54 MeV from the γ decay of the giant dipole resonance. The reaction Ca40+Ca40 at Ebeam=136 MeV was used to form the compound nucleus in the isospin I=0 channel, while the reaction Cl37+Ca44 at Ebeam=95 MeV was used as the reference reaction. The γ rays were detected with the AGATA demonstrator array coupled with LaBr3:Ce detectors. The temperature dependence of the isospin mixing was obtained and the zero-temperature value deduced. The isospin-symmetry-breaking correction δC used for the Fermi superallowed transitions was extracted and found to be consistent with β-decay data.This work was supported by PRIN No. 2001024324_01302, the Polish National Center for Science Grants No. 2013/08/ M/ST2/00591 and No. 2011/03/B/ST2/01894, and the Spanish Grant No. FPA2011-29854-C04-01. German Bundesministerium für Bildung und Forschung (BMBF) under Contract No. 05P12PKFNE TP4.Peer Reviewe

The PARIS cluster coupled to the BaFPro electronic module: data analysis from the NRF experiment at the γ\gammaELBE facility

International audience; The first cluster of the constructed PARIS calorimeter was assembled and tested atthe ELBE facility at HZDR, Dresden, Germany. The experiment was aimed at the evaluationof the performance of each detector separately as well as the whole PARIS cluster with discrete$\gamma$-ray energies seen by the PARIS ranging up to 8.9 MeV. As the detectors use phoswichconfiguration, with 2'' x 2'' x 2'' LaBr3(Ce) crystal coupled to 2'' x 2'' x 6'' NaI(Tl) one, greatcare must be taken during the data analysis process to obtain the best possible values for energyresolution. Two algorithms for data transformation from matrices created with slow vs fastpulse shaping to energy spectra were tested from which one was chosen for further analysis. Analgorithm for adding back energies of $\gamma$-rays scattered inside the cluster was prepared, as well.Energy resolution for $\gamma$-rays in 2–8 MeV range was estimated and is presented in this paper

Chemometric Analysis to Support Untargeted Lipidomics for Characterization of Irradiated and Not Irradiated Camembert Cheese

An investigation using UHPLC-Q-Orbitrap-MS and multivariate statistics was conducted to obtain lipid fingerprint of Camembert cheese and to explore its correlated variation with respect to X-ray irradiation treatment

ASE optimization by RSM for lipid profile of mozzarella cheese

A novel Accelerated Solvent Extraction (ASE) procedure, combined with Ultra-High Liquid Chromatography Orbitrap Mass Spectrometry (UHPLC-Q-Orbitrap-MS) identification provided a detailed lipidomic profile of mozzarella cheese. Response Surface Methodology (RMS), obtained from a Central Composite Design (CCD) was employed to define the optimized combination of extraction temperature, number of extraction cycles and solvent mixture (cyclohexane, methyl-tert-butyl ether and isopropanol). From response surfaces analysis, it can be affirmed that the main dependence of extraction efficiency is linked to the percentage of solvents in the mixture. Furthermore, comparing ASE extraction with Folch procedure, it is possible to affirm that they are complementary for the complete recovery of lipid classes.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

2-Dodecylcyclobutanone and 2-tetradecylcyclobutanone data in X-ray irradiated dairy products: evolution in function of irradiation doses and fat and moisture contents

Headspace‐solid phase microextraction-gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS) technique was used to investigate 2-dodecylcyclobutanone (2-DCB) and 2-tetradecylcyclobutanone (2-TCB) as X-ray induced markers in irradiated dairy products. For the first time, an intensive study was conducted on different types of milk and cheese, different in matrix composition, ripening time and technological processes

Chemometric Analysis to Support Untargeted Lipidomics for Characterization of Irradiated and Not Irradiated Camembert Cheese

An investigation using UHPLC-Q-Orbitrap-MS and multivariate statistics was conducted to obtain lipid fingerprint of Camembert cheese and to explore its correlated variation with respect to X-ray irradiation treatment.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV