The Application of Periodic Density Functional Theory to the Study of Uranyl-Containing Materials: Thermodynamic Properties and Stability

With the advent of increased computer capacities, improved computational resources, and easier access to large-scale computer facilities, the use of density functional theory methods has become nowadays a frequently used and highly successful approach for the research of solid-state materials. However, the study of solid materials containing heavy elements as lanthanide and actinide elements is very complex due to the large size of these atoms and the requirement of including relativistic effects. These features impose the availability of large computational resources and the use of high quality relativistic pseudopotentials for the description of the electrons localized in the inner shells of these atoms. The important case of the description of uranyl-containing materials and their properties has been faced recently. The study of these materials is very important in the energetic and environmental disciplines. Uranyl-containing materials are fundamental components of the paragenetic sequence of secondary phases that results from the weathering of uraninite ore deposits and are also prominent phases appearing from the alteration of the spent nuclear fuel. The development of a new norm-conserving relativistic pseudopotential for uranium, the use of energy density functionals specific for solids, and the inclusion of empirical dispersion corrections for describing the long-range interactions present in the structures of these materials have allowed the study of the properties of these materials with an unprecedented accuracy level. This feature is very relevant because these methods provide a safe, accurate, and cheap manner of obtaining these properties for uranium-containing materials which are highly radiotoxic, and their experimental studies demand a careful handling of the samples used. In this work, the results of recent applications of theoretical solid state methods based on density functional theory using plane waves and pseudopotentials to the determination of the thermodynamic properties and stability of uranyl-containing materials are reviewed. The knowledge of these thermodynamic properties is indispensable to model the dynamical behavior of nuclear materials under diverse geochemical conditions. The theoretical methods provide a profound understanding of the thermodynamic stability of these mineral phases and represent a powerful predictive tool to determine their thermodynamic properties

Theoretical Studies of the Structural, Mechanical and Raman Spectroscopic Properties of Uranyl-Containing Minerals

The incipient use of theoretical methods in the research of geomaterials reveals the great power of such methodology in the determination of the mineral properties. These methods provide a safe, accurate and cheap manner of obtaining these properties. Uranium-containing minerals are highly radiotoxic, and their experimental studies demand a careful handling of the samples used. However, theoretical methods are free of such inconveniences and may be used in the complete characterization of this type of minerals. Theoretical methods are not only a complement to the use of other experimental techniques but also a powerful predictive tool. The structural, mechanical and Raman spectroscopic properties of uranyl-containing materials, including rutherfordine soddyite, schoepite and uranophane-α, were studied by means of theoretical solid-state methods based on density functional theory using plane waves and pseudopotentials. A new norm-conserving relativistic pseudopotential for uranium atom developed in recent works was employed. These minerals are among the most important secondary phases arising from corrosion of spent nuclear fuel under the final geological disposal conditions. The computed crystal structures of these materials as well as the corresponding and X-ray powder patterns were found to be in excellent agreement with the experimental information. Therefore, the optimized structures of these minerals were employed to study the mechanical properties and stability of these minerals. These properties were obtained using the finite deformation technique. All these minerals were found to be mechanically stable since the corresponding Born stability conditions were satisfied. A large amount of relevant mechanical data were reported including bulk, Young and Shear moduli, Poisson ratios, ductility and hardness indices, anisotropy measures as well as longitudinal and transversal wave velocities. The large volume expansion and mechanical stress resulting from the corrosion of spent nuclear fuel during storage emphasize the great relevance of the mechanical information of the waste components. Finally, the computation of vibrational properties of these minerals is studied. The computed Raman spectra of these materials were found to be in good agreement with their experimental counterparts when they were available for comparison. These results demonstrate the power of the theoretical methods in the research of uranium-containing minerals

Characterization of secondary phases of spent nuclear fuel under final geological disposal conditions: theoretical and experimental studies|

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Analítica y Análisis instrumental. Fecha de lectura: 21-09-201

Antioxidant activity of hydroxytyrosol in frankfurters enriched with n-3 polyunsaturated fatty acids

8 páginas,6 tablas.The capacity of hydroxytyrosol (HXT) to inhibit lipid oxidation in cooked pork meat batter, oil-in-water emulsions and potential functional frankfurters formulated with a healthier oil combination (as animal fat replacer) was studied during chilling storage, and its effect compared with those produced by synthetic antioxidants (BHA/BHT). Although efficiency varied, HXT was an effective antioxidant during chilling storage in the three food matrices studied. In general the order of inhibition capacity of HXT against lipid oxidation (thiobarbituric acid-reactive substances-TBARS) was cooked meat batter > oil-in-water emulsion > frankfurters, whereas in the case of BHA/BHT (with lower inhibitory activity than HXT) it was cooked meat batter > oil-in-water emulsion, and there was no antioxidative effect in frankfurters. Whereas significant correlations were established between lipid oxidation (TBARS) and antioxidative capacity measured by photochemiluminescence (PCL) in frankfurters supplemented with HXT and BHA/BHT, no significant correlations were found between ferric reducing/antioxidant power assay (FRAP) and TBARS and PCL.This research was supported by the projects AGL2008-04892- CO3-01 and Consolider Ingenio 2010: CARNISENUSA (CSD2007- 00016).Peer reviewe

Development of a controlled vocabulary for learning objects' functional description in an educational repository

Proceeding of: Metadata for Knowledge and Learning (DC 2006). October 3-6, 2006. Colima, MexicoThis paper presents the development of a controlled vocabulary for functional description in an educational repository project which has adopted a DC application profile. The vocabulary, organized according to the identified functions of educational documents and learning objects' components, permits their retrieval and reuse to be improved.The DOTEINE Project has been financed by the Spanish Interministerial Commission of Science & Technology (CICYT, ref. BSO2003-04895). The IACORIE Project has been financed by the Regional Government of Madrid (Comunidad de Madrid, ref. 06/HSE/0165/2004).Publicad

Alfabetización en la información y bibliotecas escolares: una experiencia en la comunidad de Madrid

Una tarea muy ligada a la labor del documentalista, desde una perspectiva histórica, ha sido el apoyo a las políticas de alfabetización, del mismo modo ha sido una constante en España el empeño por establecer las Bibliotecas Escolares en el sistema educativo. La Sociedad de la Información y sus medios para acceder y representar el conocimiento ha desarrollado un nuevo modo de leer y escribir, una nueva alfabetización más próxima al quehacer documentalista, information literacy, alfabetización de la información. En esta comunicación realizamos una semblanza de la Hª de las Bibliotecas Escolares en nuestro país y exponemos las líneas de trabajo y los primeros resultados del Seminario de Investigación y aplicación experimental “Las Bibliotecas Escolares y la Alfabetización en la Información.A task closely linked to the work of the specialist in documentation sciences, from a historical perspective, has been the support to the policy of literacy, and, in the same way, the determination in Spain to set up School Libraries in the educational system. The Information Society and its means to accede and represent knowledge has developed a new pattern for reading and writing, a new education closer to the chore of the documentation sciences, “Information Literacy”, education of the information. In this communication we tackle a biographical out line of the history of School Libraries in our country and we lay out the working lines and the first results of the Seminary of Research and experimental application School Libraries and information literacy. The interest of this contribution lies in offering a group working vision between entities far from each other at times, School and University. From the research in progressive line, Information Literacy we show the very important role that the Documentation can play in a School Library completely adapted to the new technological environments and to the increasing needs of the community of users and generated by the Knowledge SocietyPublicad

Investigación en gestión y organización de la información: panorámica hispano brasileña

“Pesquisa em gestão e organização da informação: panorama Hispano Brasileira” -Investigación en gestión y organización de la información: panorámica hispano brasileña- tiene como objetivo consolidar los resultados del VIII Seminario Hispano-Brasileño de Investigación sobre Información, Documentación y Sociedad, así como promover el intercambio académico, científico y cultural entre las comunidades brasileña e hispana. Se reúnen aquí trabajos escogidos que abordaron esta temática.“Pesquisa em gestão e organização da informação: panorama Hispano Brasileira” -Investigación en gestión y organización de la información: panorámica hispano brasileña- tem como objectivo consolidar os resultados do VIII Seminário Hispano-Brasileiro de Pesquisa sobre Informação, Documentação e Sociedade, bem como promover o intercâmbio académico, científico e cultural entre as comunidades brasileira e hispânica. Reúne aqui obras seleccionadas que abordam esta temática.Depto. de Biblioteconomía y DocumentaciónFac. de Ciencias de la DocumentaciónTRUEpu

Methodology for Olive Pruning Windrow Assessment Using 3D Time-of-Flight Camera

The management of olive pruning residue has shifted from burning to shredding, laying residues on soil, or harvesting residues for use as a derivative. The objective of this research is to develop, test, and validate a methodology to measure the dimensions, outline, and bulk volume of pruning residue windrows in olive orchards using both a manual and a 3D Time-of-Flight (ToF) camera. Trees were pruned using trunk shaker targeted pruning, from which two different branch sizes were selected to build two separate windrow treatments with the same pruning residue dose. Four windrows were built for each treatment, and four sampling points were selected along each windrow to take measurements using both manual and 3D ToF measurements. Windrow section outline could be defined using a polynomial or a triangular function, although manual measurement required processing with a polynomial function, especially for high windrow volumes. Different branch sizes provided to be significant differences for polynomial function coefficients, while no significant differences were found for windrow width. Bigger branches provided less bulk volume, which implied that these branches formed less porous windrows that smaller ones. Finally, manual and 3D ToF camera measurements were validated, giving an adequate performance for olive pruning residue windrow in-field assessment

Memoria, patrimonio digital y políticas de información: caminos abiertos en Brasil y España

“Memória, Patrimônio Digital e Políticas de informação: trilhas abertas no Brasil e Espanha” -Memoria, patrimonio digital y políticas de información: caminos abiertos en Brasil y España- tiene como objetivo consolidar los resultados del VIII Seminario Hispano-Brasileño de Investigación sobre Información, Documentación y Sociedad, así como promover el intercambio académico, científico y cultural entre las comunidades brasileña e hispana. La memoria, el patrimonio digital y las políticas de información están intrínsecamente asociadas a las estrategias de preservación digital y actúan como directrices legales para la gestión de la preservación y para el acceso permanente a los objetos digitales producidos, seleccionados y almacenados. Pretende superar la obsolescencia tecnológica tanto de los objetos como de sus propios soportes. Una política de esta naturaleza se elabora a partir de resoluciones, normas, actos administrativos, leyes, modelos y estándares. Se puede analizar bajo los aspectos organizativos, legales y técnicos. Se reúnen aquí los trabajos escogidos que abordaron esta temática.“Memória, Patrimônio Digital e Políticas de informação: trilhas abertas no Brasil e Espanha” -Memoria, patrimonio digital y políticas de información: caminos abiertos en Brasil y España- tem como objetivo consolidar os resultados do VIII Seminário Hispano-Brasileiro de Pesquisa em Informação, Documentação e Sociedade bem como promover o intercâmbio acadêmico, científico e cultural entre as comunidades brasileira e hispana. Memória, Patrimônio Digital e Políticas de informação estão intrinsecamente associados com estratégias de preservação digital e atuam como orientação legal para a gestão da preservação e para o acesso permanente aos objetos digitais produzidos, selecionados e armazenados. Visa à superação da obsolescência tecnológica tanto dos objetos como dos seus próprios suportes. Uma política dessa natureza é elaborada com base em resoluções, normas, atos administrativos, leis, modelos e padrões. Pode ser analisada sob o aspecto organizacional, legal e técnicoDepto. de Biblioteconomía y DocumentaciónFac. de Ciencias de la DocumentaciónTRUEpu