57 research outputs found
New developments on preparation of cooled and bunched radioactive ion beams at ISOL-Facilities: the ISCOOL project and the rotating wall cooling
No full textLast years have become very productive for the research, construction and development of new facilities devoted to the production of beams with exotic radioisotopes (Radioactive Ion Beams, RIB). These beams are later used for experiments in fields like nuclear physics, atomic physics, astrophysics or medicine, among others. Within this kind of facilities, the ISOL facilities stand out. They are based on the on-line separation of radioactive isotopes produced in nuclear reactions between a target and a high-energy proton beam. The ISOL method was the pioneer for these facilities and it has kept up to now the leadership of RIB facilities. The main reason is ISOLDE, an ISOL facility located at CERN, the largest accelerator complex in the world, where this doctoral thesis has been carried out.The first innovation which is described is the design of an ion trap for the cooling and bunching of RIB's for ISOLDE, the so-called ISCOOL (ISOLDE COOLer). It is an Radio Frequency Quadrupole ion Cooler and Buncher (RFQCB), device based on the Paul traps. In these traps, the ions are confined in the three dimensions by electric fields. The ions are confined on the transverse plane with the pseudopotential well created by the Radio Frequency Quadrupole (RFQ) and focused on the longitudinal axis. At the same time, a gas (normally helium) fills the chamber with a pressure between 10-3 and 10-2 mbar. The collisions between the atoms or molecules of the gas and the ions. In addition, to drive the ions to the extraction of the RFQCB, an axial electric field is created by segmented electrodes. Different voltages are applied to these electrodes in order to choose the shape of the field. The shape can be chosen to create a potential well close to the extraction from the RFQCB in which the ions are accumulated and extracted as bunches, by the fast-switch of the voltages applied to the axial electrodes.The new ISCOOL will be installed as a permanent device of the ISOLDE beam lines.DOCTORAT EN ENGINYERIA NUCLEAR (Pla 1998
Ignorance and Semantic Tableaux: Aliseda on Abduction
No full textThis is an examination of similarities and differences between two recent models of abductive reasoning. The one is developed in Atocha Aliseda’s Abductive Reasoning: Logical Investigations into the Processes of Discovery and Evaluation (2006). The other is advanced by Dov Gabbay and the present author in their The Reach of Abduction: Insight and Trial (2005). A principal difference between the two approaches is that in the Gabbay-Woods model, but not in the Aliseda model, abductive inference is ignorance-preserving. A further differ-ence is that Aliseda reconstructs the abduction relation in a semantic tableaux environment, whereas the Woods-Gabbay model, while less systematic, is more general. Of particular note is the connection between abduction and legal reasoning
La Ortografía práctica de Miranda Podadera:: Metodología y estructura de un manual práctico
No full textEn 1921 apareció la primera edición de la Ortografía práctica de Luis Miranda
Podadera, obra capital en la enseñanza de la ortografía en el siglo xx
que, remodelada numerosas veces, todavía hoy se publica. Se trata de un
método para el ejercicio de la ortografía que influyó de forma decisiva en
generaciones de españoles hasta convertirse en una referencia obligada para profesores, alumnos y opositores. Basado en el aprendizaje memorístico de
las reglas, el dominio de la ortografía se efectúa a través de los ejercicios
que las acompañan. El presente trabajo pretende ofrecer un estudio de la
estructura de la obra y un análisis de la metodología que emplea el autor
desde la perspectiva de un manual del primer cuarto del siglo xx. Asimismo
se contrastará la metodología aplicada en dicha obra con las nuevas —y no
tan nuevas— directrices didácticas y pedagógicas a fin de poner en evidencia
en qué medida el manual de Miranda Podadera cumple con el objetivo
de enseñar las reglas ortográficas del español. Tal cotejo nos conducirá a
reflexionar sobre la enseñanza de la ortografía en su conjunto.In 1921 appeared the first edition of the Ortografía práctica of Luis Miranda
Podadera, major work on the teaching of orthography in the twentieth
century that, remodeled numerous times, it is still published. It is a method
of exercising the spelling that decisively influenced generations of Spaniards
till become a reference for teachers, students and opponents. Based on rote
learning of rules, the control of spelling is done through exercises that
accompany them. This paper aims to provide a study of the structure of
the work and an analysis of the methodology used by the author from
the perspective of a handbook of the first quarter of the twentieth century.
Furthermore, the methodology applied in this work will be contrasted with
the new —and not so new— didactic and pedagogical guidelines in order
to highlight to what extent the handbook of Miranda Podadera meets the
goal of teaching the Spanish spelling rules. Such comparison will lead us to
reflect on the teaching of spelling as a whole
Joint investigation of settling and preferential concentration of inertial particles in turbulence
No full textParticle laden flows are of a great interest in many industrial and natural systems. When the carrier flow is turbulent, a striking feature named preferential concentration takes place: particles denser than the carrier fluid tend to inhomogeneously distribute in space, forming clusters and depleted regions. The present study aims at giving new insight into the possible connection between preferential concentration and particles settling in homogeneous isotropic turbulence. Preferential concentration is quantified using Voronoi diagrams, while 3D Lagrangian Particle Tracking is used to access particles dynamics and in particular statistics of settling velocity. Independent and joint statistics of local concentration and settling velocity will be discussed. Besides, the dependence of particles settling rates on clustering and turbulence levels is further investigated with the use of Laser Phase Doppler Interferometry
¿Qué queda de la distinción entre contexto de descubrimiento y contexto de justificación?
No full textEste comentario se centra en el primer capítulo de Abductive Reasoning (2006), donde Aliseda ofrece nuevas herramientas conceptuales para examinar los modelos metodológicos que trazan una distinción de contextos en la investigación científica. Elucidamos la posición de Popper frente al problema del descubrimiento y distinguimos dos sentidos en que deliberadamente utiliza ‘discovery’ en su LSD (1959), distinción que permite reforzar la heterodoxa interpretación que hace Aliseda de la metodología popperiana. Por último, nos detenemos en la comparación entre Popper y Simon frente a la “lógica del descubrimiento”, ya que condensa las razones por las que Aliseda considera que la dicotomía descubrimiento-justificación está destinada al fracaso.
This brief commentary focuses on the first chapter of Abductive Reasoning (2006), where Aliseda offers new conceptual tools for examining the methodological models in which a distinction between contexts of scientific research is traced. In particular, we analyze Popper’s position with respect to the problem of discovery and distinguish two different senses in which he deliberately uses the term ‘discovery’ in LSD (1959); this, in turn, lends support to Aliseda’s heterodox interpretation of the Popperian methodology. Last, we examine the comparison the author makes between Popper and Simon as it contains the primary reasons for asserting that the discovery-justification dichotomy is doomed to failure
Constructions of the body through the gothic idiom in three "radical naturalist" novels of Alejandro Sawa
No full textThis thesis considers instances of corporeality in three novels (Crimen legal, Criadero de curas and Noche) by Spanish novelist Alejandro Sawa (1862-1909) from the point of view of anti-clerical Gothic aesthetics. Despite the presence of many a literary Gothic element in these novels, these works had traditionally been considered mere by-products of the influence of French naturalist author Emile Zola (1840-1902). This would be due to the “radical naturalist” sobriquet which Sawa himself chose to identify his novels with. However, this thesis contests such considerations of Sawa as a “naturalist” author and focuses instead on the Gothic influences received through French Romanticism, Spanish popular novels of the fin-du-siècle and anti-clerical propaganda, previously unexplored. The exploration of the works considered will be guided by theories such as Julia Kristeva’s concept of “abjection” or affect theory, at the core of which lies a concern with the body and/or the corporeal.
In reading Sawa’s oeuvre under a Gothic lens of corporeality, aspects of his work which had been previously unacknowledged come to the forefront. Such aspects are, for example, Sawa’s dependency on the middle-class representational idiom he allegedly so much despised, or the relationship of his novels with the anti-clerical, misogynistic nation-building project of Spain in the late nineteenth century. The image of the Spanish realist canon and the perception and understanding of Zola’s works within the Spanish letters in the last third of the nineteenth century, especially with regards to corporeality, are now more nuanced, as is Sawa’s literary standing
Constructions of the body through the gothic idiom in three "radical naturalist" novels of Alejandro Sawa
No full textThis thesis considers instances of corporeality in three novels (Crimen legal, Criadero de curas and Noche) by Spanish novelist Alejandro Sawa (1862-1909) from the point of view of anti-clerical Gothic aesthetics. Despite the presence of many a literary Gothic element in these novels, these works had traditionally been considered mere by-products of the influence of French naturalist author Emile Zola (1840-1902). This would be due to the “radical naturalist” sobriquet which Sawa himself chose to identify his novels with. However, this thesis contests such considerations of Sawa as a “naturalist” author and focuses instead on the Gothic influences received through French Romanticism, Spanish popular novels of the fin-du-siècle and anti-clerical propaganda, previously unexplored. The exploration of the works considered will be guided by theories such as Julia Kristeva’s concept of “abjection” or affect theory, at the core of which lies a concern with the body and/or the corporeal.
In reading Sawa’s oeuvre under a Gothic lens of corporeality, aspects of his work which had been previously unacknowledged come to the forefront. Such aspects are, for example, Sawa’s dependency on the middle-class representational idiom he allegedly so much despised, or the relationship of his novels with the anti-clerical, misogynistic nation-building project of Spain in the late nineteenth century. The image of the Spanish realist canon and the perception and understanding of Zola’s works within the Spanish letters in the last third of the nineteenth century, especially with regards to corporeality, are now more nuanced, as is Sawa’s literary standing
Design, integration and manufacturing of the MEBT and Dplate support frames for IFMIF LIPAc
No full textThe International Fusion Materials Irradiation Facility (IFMIF) [1] aims to provide an accelerator-based, D-Li neutron source to produce high energy neutrons at sufficient intensity and irradiation volume for DEMO materials qualification. As part of the Broader Approach (BA) agreement between Japan and EURATOM, the goal of the IFMIF/EVEDA project is to work on the engineering design of IFMIF and to validate the main technological challenges which, among a wide diversity of hardware includes the LIPAc (Linear IFMIF Prototype Accelerator) [2], a 125 mA continuous wave deuteron accelerator up to 9 MeV mainly designed and manufactured in Europe.
The Medium Energy Beam Transport line (MEBT) [3], [4] is in charge of the beam transport at 5 MeV/125 mA and matching beam parameters between two acceleration structures, the RadioFrequency Quadrupole (RFQ) and the Superconducting RF linear accelerator (SRF Linac), while the Diagnostic Plate (DPlate) [5] is a movable module with a set of diagnostics and instrumentations in charge of characterizing the beam in the different accelerator commissioning stages (RFQ commissioning, SRF Linac commissioning) and to provide accelerator operational parameters. Both beamline designs are state of art, being a real engineering (and mechanical) challenge, due to the compactness and alignment requirements from beam dynamics, and the seismic requirements from the accelerator site. An optimized design is critical in order to reduce beam losses and production of radiation at high power beam.
The present paper summarizes the mechanical design and analysis of the MEBT and Diagnostic Plate support frames, as well as their manufacturing solutions and mechanical integration with the components installed both in the MEBT and Diagnostic Plate. The mechanical design and integration show the engineering development, adopted to fulfill the strict structural, seismic and alignment requirements
Hardware availability calculations and results of the IFMIF accelerator facility
No full textHardware availability calculations have been done individually for each system of the deuteron accelerators of the International Fusion Materials Irradiation Facility (IFMIF). The principal goal of these analyses is to estimate the availability of the systems, compare it with the challenging IFMIF requirements and find new paths to improve availability performances.; Major unavailability contributors are highlighted and possible design changes are proposed in order to achieve the hardware availability requirements established for each system. In this paper, such possible improvements are implemented in fault tree models and the availability results are evaluated.; The parallel activity on the design and construction of the linear IFMIF prototype accelerator (LIPAc) provides detailed design information for the RAMI (reliability, availability, maintainability and inspectability) analyses and allows finding out the improvements that the final accelerator could have. Because of the R&D behavior of the LIPAc, RAMI improvements could be the major differences between the prototype and the IFMIF accelerator design.Peer ReviewedPostprint (published version
Hardware availability calculations and results of the IFMIF accelerator facility
No full textHardware availability calculations have been done individually for each system of the deuteron accelerators of the International Fusion Materials Irradiation Facility (IFMIF). The principal goal of these analyses is to estimate the availability of the systems, compare it with the challenging IFMIF requirements and find new paths to improve availability performances.; Major unavailability contributors are highlighted and possible design changes are proposed in order to achieve the hardware availability requirements established for each system. In this paper, such possible improvements are implemented in fault tree models and the availability results are evaluated.; The parallel activity on the design and construction of the linear IFMIF prototype accelerator (LIPAc) provides detailed design information for the RAMI (reliability, availability, maintainability and inspectability) analyses and allows finding out the improvements that the final accelerator could have. Because of the R&D behavior of the LIPAc, RAMI improvements could be the major differences between the prototype and the IFMIF accelerator design.Peer Reviewe
- …
