Colored semi-transparent Cu-Si oxide thin films prepared by magnetron sputtering

Colored semi-transparent Cu-Si oxide thin films have been prepared by reactive magnetron sputtering from a single cathode of copper-silicon composition. Thin films of different composition and optical response were obtained by changing process parameters like the relative amount of copper in the target and the O2/Ar mixture of the reactive plasma gas. The film characteristics were analyzed by several techniques. Their optical properties (refractive index, absorption coefficient, color) have been correlated with the process parameters used in the film preparation as well as with the film stoichiometry and chemistry.Ministerio de Ciencia e Innovación CEN-20072014, MAT2010-18447, MAT2010-21228, CSD2008–00023Junta de Andalucía P09-TEP5283, CTS-518

Uso de microfluorescencia de rayos X y otras técnicas nucleares no destructivas para el estudio de joyas y metales arqueológicos

Hoy en día, el estudio de objetos antiguos de metal incluye el análisis por medio de métodos físico-químicos no destructivos desarrollados en las décadas pasadas. Uno de los parámetros más importantes que deben conocerse de una muestra es su composición química, ya que esta información contribuye significativamente a la determinación de varias suposiciones y a la respuesta de muchas preguntas que surgen mientras se estudia un objeto de gran valor histórico. La fluorescencia de rayos X es una técnica bien conocida y muy empleada en el análisis elemental de objetos antiguos de metal y el nuevo desarrollo del microhaz focalizado de rayos X descrito en este texto incrementa su adecuación para el estudio de técnicas antiguas de fabricación y decoración. Esta técnica de análisis superficial se complementa con la técnica de transmisión de rayos gamma, que ha sido utilizada para la estimación de la composición en el interior de monedas de plata-cobre y objetos realizados en otras aleaciones del cobre. Describimos también el sistema de microfluorescencia confocal portátil desarrollado por nuestro Grupo para la obtención de perfiles en profundidad de forma no destructiva.The study of ancient metal artefacts includes nowadays the non-destructive analysis by means of chemical-physical methods developed in the past decades. One of the most important parameters to be known from a sample is its chemical composition, as this information significantly contributes to the determination of several assumptions and to the response of many questions arisen from the study of a valuable heritage object. X-ray fluorescence is a well-known technique very much employed for the elemental analysis of ancient metal artefacts and the new implementation of a microfocused X-ray beam described in this text increases its applicability for the study of manufacture and decorative ancient techniques. This surface analytical method is complemented with the Gamma Ray Transmission technique, which has been employed in the bulk composition estimation of silver-copper coins and other copper based alloy samples. We also describe a portable confocal microfluorescence system developed by our Group to obtain non-destructive depth profiles.Ministerio de Economía y Competitividad (España) HAR2012-33002Ministerio de Economía y Competitividad (España) HAR2015-67113-PJunta de Andalucía P09-HUM454

Accelerator-based research activities at "Centro Nacional de Aceleradores", Seville (Spain)

5 páginas.-- PACS nrs.: 29.17.+w; 29.20.−c; 82.80.−d; 07.30.Kf.In February 1998, almost 10 years ago, the set-up of the first IBA (ion beam analysis) facility in Spain took place with the arrival of a 3 MV tandem accelerator [J. García-López, F.J. Ager, M. Barbadillo-Rank, F.J. Madrigal, M.A. Ontalba, M.A. Respaldiza, M.D. Ynsa, Nucl. Instr. and Meth. B 161–163 (2000) 1137]. Since then, an intensive research program using IBA techniques has been carried out. Subsequently, a cyclotron for 18 MeV protons has been also installed at the “Centro Nacional de Aceleradores” (CNA), devoted mainly to isotope production for PET (positron emission tomography) techniques, but possibly applied to material analysis and damage studies on a dedicated beam line. Moreover, a 1 MV tandem has been recently installed for AMS (accelerator mass spectrometry) 14C dating and environmental research with other isotopes.In the present paper we describe the new facilities and the developments of the 3 MV tandem beam lines occurred during the past years, as well as some examples of the most recent research activities in our Center in the fields of Material Science, Archaeometry, Biomedicine and Environment.Thanks are due to the three host Institutions, Universidad de Sevilla, Junta de Andalucía and CSIC, for the continuous support given to our Centre.Peer reviewe

Fluoride exposure duringintrauterine and lactation periods promotes changes in the offspring rats' alveolar bone

The importance of fluoride (F) for oral health is well established in the literature. However, evidence suggests that excessive exposure to this mineral is associated with adverse effects at different life stages and may affect many biological systems, especially mineralized tissues. The purpose of this study was to investigate the effects of F exposure during pregnancy and breastfeeding on the alveolar bone of the offspring since the alveolar bone is one of the supporting components of the dental elements. For this, the progeny rats were divided into three groups: control, 10 mg F/L, and 50 mg F/L for 42 (gestational and lactation periods). Analysis of the quantification of F levels in the alveolar bone by particle-induced gamma emission; Raman spectroscopy to investigate the physicochemical aspects and mineral components; computed microtomography to evaluate the alveolar bone microstructure and analyses were performed to evaluate osteocyte density and collagen quantification using polarized light microscopy. The results showed an increase in F levels in the alveolar bone, promoted changes in the chemical components in the bone of the 50 mg F/L animals (p < 0.001), and had repercussions on the microstructure of the alveolar bone, evidenced in the 10 mg F/L and 50 mg F/L groups (p < 0.001). Furthermore, F was able to modulate the content of organic bone matrix, mainly collagen; thus, this damage possibly reduced the amount of bone tissue and consequently increased the root exposure area of the exposed groups in comparison to a control group (p < 0.001). Our findings reveal that Fcan modulate the physicochemical and microstructural dimensions and reduction of alveolar bone height, increasing the exposed root region of the offspring during the prenatal and postnatal period. These findings suggest that F can modulate alveolar bone mechanical strength and force dissipation functionality.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. R.R.L is a researcher from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and received grant under number 312275/2021-8. Also this research was funded by PROCAD Amazônia – CAPES (23038.005350/2018–78).Peer reviewe

Exploring advantages of 4He-PIXE analysis for layered objects in cultural heritage

In the field of cultural heritage 4He particle beams are often used to perform RBS analysis. In most cases the simultaneously produced X-rays are not considered for PIXE analysis. This paper aims to explore the potentials of 4He induced X-ray emission (α-PIXE) using 4, 5 and 6 MeV 4He beams and to compare its performance with that of conventional PIXE with 3 MeV protons. The α-PIXE and α-RBS spectra were collected at the same time in a vacuum chamber. The X-ray yields produced by 6 MeV 4He beam for K-lines were found to be superior to those of protons for atomic numbers below 25. An additional advantage of α-PIXE is the lower bremsstrahlung background which leads to an improved peak to noise ratio for certain elements. © 2006 Elsevier B.V. All rights reserved.Peer Reviewe

PIXE analysis in subfossil bone samples: Testing a preparation protocol

Trabajo presentado al XI Congreso Ibérico de Arqueometría, celebrado en Évora (Portugal) del 14 al 16 de octubre de 2015.[ES]: Los huesos subfósiles son una fuente de información que va más allá del estudio taxonómico y tafonómico a nivel macroscópico. En este sentido, las técnicas de ADN antiguo y las físico-químicas están aportando nuevas perspectivas a los análisis paleobiológicos llegando a describir patrones de domesticación, migración, contaminación ambiental, etc. No obstante, el proceso de diagénesis, por el que pasan todos los restos subfósiles, conlleva una problemática asociada que afecta a este tipo de estudios genéticos y físico-químicos. Además de las pérdidas de material que se producen por erosión, la composición química se puede ver afectada por procesos de disolución, precipitación, absorción, sustitución mineral y recristalización. Todos estos problemas de contaminación están siendo tratados por diferentes especialistas que preparan las muestras en función de los objetivos a alcanzar y de las técnicas a utilizar. Con este trabajo de investigación se pretende desarrollar un protocolo de preparación de muestras efectivo para la detección de contaminaciones ambientales prehistóricas e históricas a partir del estudio de elementos traza con una técnica no destructiva, PIXE.[EN]: Nowadays, we are obtaining new information about our history using genetic and physicchemical analysis on subfossil bones. Nevertheless, during the fossilization there are several processes that could change the results of these kinds of analysis. The chemical composition could change due to processes of dissolution, precipitation, absorption, mineral substitution or recrystallization. All of these problems are being studied by different research teams with different objectives, but in this paper, we have essayed some protocols to clean samples in the study of ancient bioaccumulations registered in subfossil bones using PIXE technique.Este trabajo ha sido realizado gracias a la financiación proporcionada por la Junta de Andalucía al Proyecto de Excelencia “Nuevo enfoque técnicometodológico para la conservación y conocimiento del patrimonio arqueológico orgánico: Paleobiología, ADN antiguo y análisis físico-químicos”.Peer Reviewe

Uranium concentrations in NORM efflorescences formed in a phosphogypsum legacy site determined by PIXE

Trabajo presentado a la 4th International Conference on Environmental Radioactivity: Radionuclides as Tracers of Environmental Processes, celebrada en Vilnius (Lithuania) del 29 de mayo al 2 de junio de 2017.In the vicinity of the town of Huelva (south-western coast of Spain) the restoration of a NORM legacy site covering some tens of hectares and accumulating around 10(8) tons of phopshogypsum (PG) is planned. This PG was generated during near 50 years as a by-product in the production of phosphoric acid in a big industrial complex located in the vicinity.Peer reviewe

Ion beam analysis of elemental signatures in uranium dioxide samples: importance for nuclear forensics

et al.In this paper the suitability of two non-destructive analytical techniques for identification of elemental signatures in samples containing uranium of different enrichments was studied. The measurements were based on particle induced X-ray emission (PIXE) and particle induced gamma-ray emission (PIGE) methods. The samples were irradiated by 3 and 5 MeV protons at the 3 MV Tandetron™ of Horia Hulubei National Institute for Physics and Nuclear Engineering. The characteristic X and gamma rays were measured using high purity germanium (HPGe) detectors. The GUPIX software was applied for processing the PIXE spectra, while a relative standardization was applied for PIGE analysis by using certified comparator standards and proton stopping powers calculated by SRIM.Peer Reviewe

The new Cyclone 18/9 beam transport line at the CNA (Sevilla) for high energy PIXE applications

4 pages.-- PACS nrs.: 81.70.Jb; 82.45.Bb; 82.80.Ej; 82.80.Yc.-- Nucl. Instr. and Meth. in Phys. Res. B Volume 266, Issue 8, (April 2008): Ion Beam Analysis - Proceedings of the Eighteenth International Conference on Ion Beam Analysis, Eighteenth International Conference on Ion Beam Analysis.The Cyclone 18/9 cyclotron system at the Centro Nacional de Aceleradores (Sevilla, Spain) is commonly used to create short life radioisotopes for PET applications. Besides, an external beam transport line has been recently installed in one of the target ports with two major purposes: to study the effects of 18 MeV protons irradiation on the behaviour of electronic devices for space applications and to complement the analysis of materials using our 3 MV tandem accelerator with the PIXE measurements at high energy.In this work, the main elements of our beamline will be briefly described and the first PIXE application will be presented. The usual PIXE, in the analysis of archaeological metallic objects, using around 3 MeV protons requires having a shiny area. Our purpose is to obtain a deeper determination of the bulk composition bombarding with 18 MeV protons through the corroded samples surfaces, without polishing the ancient object. To check this methodology high energy PIXE has been performed on two fibulae of the Later Bronze Age and First Iron Age, coming from the area around Sevilla.This work is partially supported by the Projects MAT2006-03519 (Spanish MEC) and P06-TEP-01739 (Junta de Andalucía).Peer reviewe

Colored semi-transparent Cu-Si oxide thin films prepared by magnetron sputtering

13 páginas, 11 figuras, 1 tabla.-- et al.Colored semi-transparent Cu-Si oxide thin films have been prepared by reactive magnetron sputtering from a single cathode of copper-silicon composition. Thin films of different composition and optical response were obtained by changing process parameters like the relative amount of copper in the target and the O2/Ar mixture of the reactive plasma gas. The film characteristics were analyzed by several techniques. Their optical properties (refractive index, absorption coefficient, color) have been correlated with the process parameters used in the film preparation as well as with the film stoichiometry and chemistry.We thank the Spanish Ministry of Science and Innovation (Cenit ARTDECO CEN-20072014, MAT2010-18447, MAT2010-21228, Consolider FUNCOAT CSD2008–00023) and the Junta de Andalucía (projects P09-TEP5283 and CTS-5189) for financial support.Peer Reviewe