Recursos de colección

Archivo Digital UPM (113.270 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Materiales

Mostrando recursos 1 - 20 de 31

  1. Single - and double energy swift and slow heavy ion irradiated optical waveguides in Er: Tungstene-Tellurite glass and BGO for telecom applications

    Bányász, István; Olivares, J.; Peña Rodríguez, Ovidio Y.; Crespillo Almenara, Miguel; Zolnai, Z.; Fried, M.; Lohner, T.; Berneschi, S.; Righini, G.; Pelli, S.; Nunzi Conti, G.
    The fabrication of broadband amplifiers in wavelength division multiplexing (WDM) around 1.55 m, as they exhibit large stimulated cross sections and broad emission bandwidth. Bi4Ge3O12 (eultine type BGO) - well known scintillator material, also a rare-earth host material, photorefractive waveguides produced in it only using light ions in the past. Recently: MeV N+ ions and swift O5+ and C5+ ions, too*. Bi12GeO20 (sillenite type BGO) - high photoconductivity and photorefractive sensitivity in the visible and NIR good candidate for real-time holography and optical phase conjugation, photorefractive waveguides produced in it only using light ions. No previous attempts of ion beam...

  2. Tunable Fano resonance in symmetric multilayered gold nanoshells

    Peña Rodríguez, Ovidio Y.; Rivera de Mena, Antonio; Campoy Quiles, Mariano; Pal, Umapada
    Fano resonances (FRs) are produced when a discrete state is coupled with a continuum. In addition to fundamental scientific interests, FRs in plasmonic systems give rise to the so-called plasmon-induced transparency. In this work we have studied the evolution of dipole-dipole all-plasmonic FRs in symmetric multilayered nanoshells as the function of their geometrical parameters. We demonstrate that symmetry breaking is not mandatory for controlling the Fano resonance in such multilayered nanoshells. Generation of FRs in these symmetric nanostructures presents clear advantages over their asymmetric counterparts, as they are easier to fabricate and can be used in a wider range of...

  3. Comparative study of ion beam-irradiation effects on silica and α-quartz: evidences for excitonic mechanisms

    Manzano Santamaría, Javier; Olivares, J.; Peña Rodríguez, Ovidio Y.; Rivera de Mena, Antonio; Crespillo Almenara, Miguel; Agullo Lopez, Fernando
    Introduction - SiO 2 •Simple composition and structure; Crystalline and amorphous phases •Adequate for atomistic simulations •Abundant in nature. Relevant for many technologies -Irradiation with swift heavy ions: •They provide EXTREME physical conditions •Very high excitation densities similar to high power lasers •Very high local temperatures •By playing with high energy and heavy mass (SHI) : •One can go from low electronic excitations (collisions regime) to high electronic excitations (electronic regime

  4. Laser ablation modelling of aluminium, silver and crystalline silicon for applications in photovoltaic technologies

    Colina Brito, Mónica; Molpeceres Álvarez, Carlos Luis; Morales Furió, Miguel; Allens-Perkins, F.; Guadaño, G.; Ocaña Moreno, José Luis
    Laser material processing is being extensively used in photovoltaic applications for both the fabrication of thin film modules and the enhancement of the crystalline silicon solar cells. The two temperature model for thermal diffusion was numerically solved in this paper. Laser pulses of 1064, 532 or 248 nm with duration of 35, 26 or 10 ns were considered as the thermal source leading to the material ablation. Considering high irradiance levels (108–109 W cm−2), a total absorption of the energy during the ablation process was assumed in the model. The materials analysed in the simulation were aluminium (Al) and silver...

  5. Ionoluminescence induced by swift heavy ions in silica and quartz: a comparative analysis

    Jimenez Rey, D.; Peña Rodríguez, Ovidio Y.; Manzano Santamaría, Javier; Olivares, J.; Muñoz Martín, Ángel; Rivera de Mena, Antonio; Agullo Lopez, Fernando
    Ionoluminescence (IL) of the two SiO2 phases, amorphous silica and crystalline quartz, has been comparatively investigated in this work, in order to learn about the structural defects generated by means of ion irradiation and the role of crystalline order on the damage processes. Irradiations have been performed with Cl at 10 MeV and Br at 15 MeV, corresponding to the electronic stopping regime (i.e., where the electronic stopping power Se is dominant) and well above the amorphization threshold. The light-emission kinetics for the two main emission bands, located at 1.9 eV (652 nm) and 2.7 eV (459 nm), has been...

  6. Techniques to accelerate convergence of stress-controlled molecular dynamics simulations of dislocation motion

    Cereceda, D.; Perlado Martín, José Manuel; Marian, Jaime
    Dislocation mobility —the relation between applied stress and dislocation velocity—is an important property to model the mechanical behavior of structural materials. These mobilities reflect the interaction between the dislocation core and the host lattice and, thus, atomistic resolution is required to capture its details. Because the mobility function is multiparametric, its computation is often highly demanding in terms of computational requirements. Optimizing how tractions are applied can be greatly advantageous in accelerating convergence and reducing the overall computational cost of the simulations. In this paper we perform molecular dynamics simulations of ½ 〈1 1 1〉 screw dislocation motion in tungsten...

  7. Conceptual design of the liquid metal laboratory of the TECHNOFUSION facility

    Abánades Velasco, Alberto; García, A.; Casal, N.; Perlado Martín, José Manuel; Ibarra, A.
    The application of liquid metal technology in fusion devices requires R&D related to many phenomena: interaction between liquid metals and structural material as corrosion, erosion and passivation techniques; magneto-hydrodynamics; free surface fluid-dynamics and any other physical aspect that will be needed for their safe reliable operation. In particular, there is a significant shortage of experimental facilities dedicated to the development of the lithium technology. In the framework of the TECHNOFUSION project, an experimental laboratory devoted to the lithium technology development is proposed, in order to shed some light in the path to IFMIF and the design of chamber's first wall...

  8. Optimization of laser-firing processes for silicon-heterojunction solar-cell back contacts

    Sanchez Aniorte, Maria Isabel; Barrio, R.; Casado, A.; Morales Furió, Miguel; Carabe, J.; Gandia, J.J.; Molpeceres Álvarez, Carlos Luis
    One of the key steps to achieve high efficiencies in amorphous/crystalline silicon photovoltaic structures is to design low-ohmic-resistance backcontacts with good passivation in the rear part of the cell. A well known approach to achieve this goal is to use laser-fired contact (LFC) processes in which a metal layer is fired through the dielectric to define good contacts with the semiconductor. However, and despite the fact that this approach has demonstrated to be extremely successful, there is still enough room for process improvement with an appropriate optimization. In this paper, a study focused on the optimal adjustment of the irradiation...

  9. Application of Ultraintense Lasers to validate materials for laser fusion: production of ions and other relevant species

    Alvarez Ruiz, Jesus; Mima, K.; Tanaka, K.; Perlado Martín, José Manuel
    Justification of the need and demand of experimental facilities to test and validate materials for first wall in laser fusion reactors - Characteristics of the laser fusion products - Current ?possible? facilities for tests Ultraintense Lasers as ?complete? solution facility - Generation of ion pulses - Generation of X-ray pulses - Generation of other relevant particles (electrons, neutrons..)

  10. Materials Research for HiPER Laser Fusion Facilities: Chamber Wall, Structural Material and Final Optics

    Alvarez Ruiz, Jesus; Rivera de Mena, Antonio; Gonzalez Arrabal, Raquel; Garoz Gómez, David; Rio Redondo, Emma del; Perlado Martín, José Manuel
    The European HiPER project aims to demonstrate commercial viability of inertial fusion energy within the following two decades. This goal requires an extensive Research &Development program on materials for different applications (e.g., first wall, structural components and final optics). In this paper we will discuss our activities in the framework of HiPER to develop materials studies for the different areas of interest. The chamber first wall will have to withstand explosions of at least 100 MJ at a repetition rate of 5-10 Hz. If direct drive targets are used, a dry wall chamber operated in vacuum is preferable. In this...

  11. IFMIF suitability for evaluation of fusion functional materials

    Casal, N.; Sordo Balbín, Fernando; Mota, F.; Jordanova, J.; Garcia, A.; Ibarra, A.; Vila, R.; Rapisarda, D.; Queral, V.; Perlado Martín, José Manuel
    The International FusionMaterials Irradiation Facility (IFMIF) is a future neutron source based on the D-Li stripping reaction, planned to test candidate fusionmaterials at relevant fusion irradiation conditions. During the design of IFMIF special attention was paid to the structural materials for the blanket and first wall, because they will be exposed to the most severe irradiation conditions in a fusion reactor. Also the irradiation of candidate materials for solid breeder blankets is planned in the IFMIF reference design. This paper focuses on the assessment of the suitability of IFMIF irradiation conditions for testing functionalmaterials to be used in liquid blankets and...

  12. Laser Shock Microforming of Thin Metal Sheets

    Ocaña Moreno, José Luis; Morales Furió, Miguel; García-Ballesteros Ramírez, Juan José; Porro González, Juan Antonio; Garcia Garcia, Oscar; Molpeceres Álvarez, Carlos Luis
    Continuous and long-pulse lasers have been used for the forming of metal sheets in macroscopic mechanical applications. However, for the manufacturing of micro-electromechanical systems (MEMS), the applicability of such type of lasers is limited by the long-relaxation-time of the thermal fields responsible for the forming phenomena. As a consequence of such slow relaxation, the final sheet deformation state is attained only after a certain time, what makes the generated internal residual stress fields more dependent on ambient conditions and might make difficult the subsequent assembly process from the point of view of residual stresses due to adjustment. The use of...

  13. Cálculo de la resistencia a la fatiga superficial en superficies con lubricación elastohidrodinámica mediante el criterio de Dang Van

    Guerra Ochoa, Eduardo de la; Chacón Tanarro, Enrique; Lafont Morgado, Pilar; Echávarri Otero, Javier; Muñoz Guijosa, Juan Manuel; Muñoz Sanz, José Luis; Diaz Lantada, Andres
    Los fenómenos de fatiga superficial en sus diferentes escalas (micropitting, pitting, spalling), aparecen en multitud de elementos mecánicos en contacto lubricado como pueden ser los engranajes o rodamientos o en elementos con contacto seco como son las ruedas de ferrocarril. Los defectos que aparecen en las superficies en contacto debidos a estos fenómenos empeoran las condiciones de funcionamiento, provocando vibraciones, desgaste prematuro y en los casos más extremos el fallo de la máquina. El procedimiento que se sugiere en este artículo se inicia con el cálculo de los parámetros que definen el contacto elastohidrodinámico y que tienen influencia en la...

  14. Tecnologías de materiales con aplicaciones en fusión y su desarrollo en la instalación TechnoFusión

    Fernandez, P.; Garcia Cortes, I.; Gonzalez, M.; Gonzalez Arrabal, Raquel; Hernandez, T.; Ibarra, A.; Jimenez Rey, D.; Monge, M.A.; Pareja, R.; Pastor Caño, Jose Ignacio; Perlado Martín, José Manuel; Roman, R.
    El futuro Centro Nacional de Tecnologías para la Fusión, TechnoFusión, tiene como objetivo desarrollar aquellas tecnologías, relacionadas con materiales, metales líquidos, manipulación remota y simulación, que permitan avanzar en los actuales retos que supone el uso de la fusión nuclear. Sus instalaciones, abiertas al servicio de la comunidad científica externa, garantizarán una destacada participación de empresas y grupos de investigación españoles. En esta contribución se describirán y analizarán las instalaciones que TechnoFusión construirá con capacidad para abordar: la fabricación y procesado de nuevas aleaciones a escala semiindustrial; el comportamiento de materiales, simulando las condiciones durante operación mediante una instalación de...

  15. Waste Management Assessment of Candidate Materials for HiPER Reaction Chamber

    Sanz Gonzalo, Javier; Juarez Mañas, Rafael; Ognissanto, Flora; Perlado Martín, José Manuel
    One of the critical decisions in the HiPER project is to select the most appropriate material for the reaction chamber. Within this framework, we investigate the performance of different steel alloys with respect to waste management. The capabilities of commercial steels, both austenitic and ferritic/martensitic, compared to reduced-activation ferritic/martensitic steels are evaluated as for different waste management strategies (near surface burial, clearance, hands-on and remote recycling). The examined materials are: SS304, SS316, mod.9Cr-1Mo and HT9 and EUROFER. Real impurities concentrations are taken into account, and their impact is analyzed. In the study, we have assumed the most exigent HiPER 4a...

  16. Modelos de elementos finitos de componentes de autobuses fabricados en materiales compuestos

    Grimaldi Pastoril, Rocío; Alcalá Fazio, Enrique
    La creciente preocupación por la seguridad en el transporte de pasajeros, ha hecho que las estructuras de los autobuses y autocares se vean sometidas a solicitaciones cada vez más exigentes, sobre todo ante condiciones de vuelco cuyos requerimientos vienen determinados por el Reglamento 66 de ginebra. Es por eso que en esta ponencia se pretende presentar una alternativa de pilares de estructura con materiales compuestos para el uso de los mismos como método reductor de masa de los vehículos. Para ello se presentan ensayos a flexión de pilares y modelos de cálculos validados con dichos ensayos.

  17. Materials Research for HiPER Laser Fusion Facilities: Chamber Wall, Structural Material and Final Optics.

    Alvarez Ruiz, Jesus; Rivera de Mena, Antonio; Gonzalez Arrabal, Raquel; Garoz Gómez, David; Rio Redondo, Emma del; Perlado Martín, José Manuel
    The European HiPER project aims to demonstrate commercial viability of inertial fusion energy within the following two decades. This goal requires an extensive Research &Development program on materials for different applications (e.g., first wall, structural components and final optics). In this paper we will discuss our activities in the framework of HiPER to develop materials studies for the different areas of interest. The chamber first wall will have to withstand explosions of at least 100 MJ at a repetition rate of 5-10 Hz. If direct drive targets are used, a dry wall chamber operated in vacuum is preferable. In this...

  18. Estudio del comportamiento de módulos de autobuses fabricados en materiales compuestos ante ensayo de vuelco

    Grimaldi Pastoril, Rocío; Alcalá Fazio, Enrique; Martín López, Ángel Luis; Aparicio Izquierdo, Francisco
    La creciente preocupación por la seguridad en el transporte de pasajeros, ha hecho que las estructuras de los autobuses y autocares se vean sometidas a solicitaciones cada vez más exigentes, sobre todo ante condiciones de vuelco cuyos requerimientos vienen determinados por el Reglamento 66 de ginebra. Es por eso que en esta ponencia se pretende presentar una alternativa de estructura con materiales compuestos para el uso de los mismos como método reductor de masa de los vehículos. Para ello se presentan ensayos a flexión de pilares, anillos, módulo y modelos de cálculos validados con dichos ensayos.

  19. Induction of Engineered Residual Stresses Fields and Associate Surface Properties Modification by Short Pulse Laser Shock Processing

    Ocaña Moreno, José Luis; Morales Furió, Miguel; Porro González, Juan Antonio; Blasco Litago, Manuel; Molpeceres Álvarez, Carlos Luis; Iordachescu, Danut; Gomez-Rosas, G.; Rubio-Gonzalez, C.
    Laser shock processing (LSP) is consolidating as an effective technology for the improvement of metallic materials surface properties involving their fatigue life. The main acknowledged advantage of the LSP technique consists on its capability of inducing a relatively deep compression residual stresses field into metallic alloy pieces allowing an improved mechanical behaviour, explicitly the life improvement of the treated specimens against wear, crack growth and stress corrosion cracking. Progress accomplished by the authors in the line of practical development of the LSP technique at an experimental level, aiming its integral assessment from an interrelated theoretical and experimental point of view,...

  20. Centro de entrenamiento y desarrollo del bambu Mbeya - Tanzania

    Espinosa Benito, Jaime
    Informe Final del estudiante sobre su estancia en Mbeya (Tanzania), trabajando con la cooperativa Mbeya Bamboo Women Group, dentro del Programa de Ayudas PFCD-2010 de la UPM. El proyecto pretendía potenciar el uso del bambú en Tanzania, aprovechando la coyuntura que ofrecía el Plan MKUKUTA, de implantación nacional para el crecimiento económico y la reducción de la pobreza, centrándose en el uso del bambú rollizo y especialmente en su empleo para fines constructivos.

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