Study of laser-plasma interaction with particle-in-cell simulations: attosecond pulse generation and proton acceleration

The advancement of lasers over the last decades has allowed researchers to explore new regimes of physics and their applications. High power lasers interacting with plasmas have provided with the tools to create high frequency ultrashort pulsed radiation, near the X-ray regime and with temporal lengths on the attosecond scale, and has allowed to create compact and cheap particle accelerators. Numerical simulations are a fundamental tool in the advancement of this scientific area, since they provide with insights into the physical processes involved and they can be used to design experiments. In this thesis we present the results of numerical simulations for ultrashort pulse production, ion acceleration and other laser-plasma applications

Frequency gating to isolate single attosecond pulses with overdense plasmas using particle-in-cell simulations

We present the isolation of single attosecond pulses for multi-cycle and few-cycle laser pulses from high harmonic generation in overdense plasmas, calculated with particle-incell simulations. By the combination of two laser pulses of equal amplitude and a small frequency shift between them, we demonstrate that it is possible to shorten the region in which the laser pulse is most intense, therefore restricting the generation of high harmonic orders in the form of attosecond pulses to a narrower time window. The creation of this window is achieved due to the combination of the laser pulse envelope and the slow oscillating wave obtained from the coherent sum of the two pulses. A parametric scan, performed with particle-in-cell simulations, reveals how the pulse isolation behaves for different input laser pulse lengths and which are the optimal frequency shifts between the two laser pulses in each case, giving the conditions for having a good isolation of an attosecond pulse when working with laser-plasma interaction in overdense targets.European Union and the Spanish Ministry of Economy and Competitivity (MINECO) (MAT2015-71119-R AEI/FEDER); Xunta de Galicia/FEDER (Agrup2015/11 (PC034)); Spanish Ministry of Education, Culture and Sports (MECD) (FPU14/00289)S

Table-top laser-based proton acceleration in nanostructured targets

The interaction of ultrashort, high intensity laser pulses with thin foil targets leads to ion acceleration on the target rear surface. To make this ion source useful for applications, it is important to optimize the transfer of energy from the laser into the accelerated ions. One of the most promising ways to achieve this consists in engineering the target front by introducing periodic nanostructures. In this paper, the effect of these structures on ion acceleration is studied analytically and with multidimensional particle-in-cell simulations.Weassessed the role of the structure shape, size, and the angle of laser incidence for obtaining the efficient energy transfer. Local control of electron trajectories is exploited to maximize the energy delivered into the target. Based on our numerical simulations, we propose a precise range of parameters for fabrication of nanostructured targets, which can increase the energy of the accelerated ions without requiring a higher laser intensity.This work has been partially supported by the Xunta de Galicia/FEDER under contract Agrup2015/11 (PC034) and by MINECO under contracts MAT2015-71119-R and FIS2015-71933-REDT. The authors would like to acknowledge the OSIRIS Consortium, consisting of UCLA and IST (Lisbon, Portugal) for the use of OSIRIS, for providing access to the OSIRIS framework. M Blanco also thanks the Ministry of Education of the Spanish government for the FPU fellowship. Camilo Ruiz also thanks MINECO project FIS2016-75652-P M Vranic acknowledges the support of ERC-2010-AdG Grant 267841 and LASERLAB-EUROPE IV—GA No. 654148. Simulations were performed at the Accelerates cluster (Lisbon, Portugal)S

A UAV and Blockchain-Based System for Industry 4.0 Inventory and Traceability Applications

[Abstract] Industry 4.0 has paved the way for a world where smart factories will automate and upgrade many processes through the use of some of the latest emerging technologies. One of such technology is Unmanned Aerial Vehicles (UAVs), which have evolved a great deal in the last years in terms of technology (e.g., control units, sensors, UAV frames) and have reduced significantly their cost. UAVs can help industry in automatable and tedious tasks, like the ones performed on a regular basis for determining the inventory and for preserving the traceability of certain items. Moreover, in such tasks, it is essential to determine whether the collected information is valid or true, especially when it comes from untrusted third-parties. In such a case, blockchain, another Industry 4.0 technology that has become very popular in other fields like finance, has the potential to provide a higher level of transparency, security, trust and efficiency in the supply chain and enable the use of smart contracts. Thus, in this paper, the design and preliminary results are presented of a UAV-based system aimed at automating the inventory and keeping the traceability of industrial items attached to Radio-Frequency IDentification (RFID) tags. Such a system can use a blockchain to receive the inventory data collected by UAVs, validate them, ensure their trustworthiness and make them available to the interested partiesXunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/01Agencia Estatal de Investigación; TEC2016-75067-C4-1-

A UAV and Blockchain-Based System for Industry 4.0 Inventory and Traceability Applications

[Abstract] Industry 4.0 has paved the way for a world where smart factories will automate and upgrade many processes through the use of some of the latest emerging technologies. One of such technology is Unmanned Aerial Vehicles (UAVs), which have evolved a great deal in the last years in terms of technology (e.g., control units, sensors, UAV frames) and have reduced significantly their cost. UAVs can help industry in automatable and tedious tasks, like the ones performed on a regular basis for determining the inventory and for preserving the traceability of certain items. Moreover, in such tasks, it is essential to determine whether the collected information is valid or true, especially when it comes from untrusted third-parties. In such a case, blockchain, another Industry 4.0 technology that has become very popular in other fields like finance, has the potential to provide a higher level of transparency, security, trust and efficiency in the supply chain and enable the use of smart contracts. Thus, in this paper, the design and preliminary results are presented of a UAV-based system aimed at automating the inventory and keeping the traceability of industrial items attached to Radio-Frequency IDentification (RFID) tags. Such a system can use a blockchain to receive the inventory data collected by UAVs, validate them, ensure their trustworthiness and make them available to the interested partiesXunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/01Agencia Estatal de Investigación; TEC2016-75067-C4-1-

Phase matching effects in high harmonic generation at the nanometer scale

Plasmon resonances are known to amplify the electromagnetic fields near metallic nanostructures, providing a promising scheme to generate extreme-ultraviolet harmonics using low power drivings. During high-order harmonic generation (HHG), the driving and harmonic fields accumulate a phase di erence as they propagate through the target. In a typical set-up –a laser focused into a gas jet– the propagation distances amount to several wavelengths, and the cumulative phase-mismatch a ects strongly the e ciency and properties of the harmonic emission. In contrast, HHG in metallic nanostructures is considered to overcome these limitations, as the common sources of phase mismatch –optical density and focusing geometry– are negligible for subwavelength propagation distances. We demonstrate that phase matching still plays a relevant role in HHG from nanostructures due to the non-perturbative character of HHG, that links the harmonic phase to the intensity distribution of the driving field. Our computations show that widely used applications of phase matching control, such as quantum path selection and the increase of contrast in attosecond pulse generation, are also feasible at the nanoscale.Junta de Castilla y León (SA046U16) and MINECO (FIS2013-44174-P, FIS2016-75652-P, FIS2015-71933-REDT, SEV-2015-0522, FIS2013-46768-P, FIS2016-79508-P). M. Blanco is funded by FPU grant program of MECD. C. H.-G. is funded by Marie Curie International Outgoing Fellowship within the EU Seventh Framework Programme for Research and Technological Development (2007-2013), grant Agreement No. 328334. A. Chacón and M. Lewenstein also acknowledge support from Adv. ERC grant OSYRIS, Generalitat de Catalunya (SGR 874, CERCA Program), and Fundació Privada CellexS

Efectos de metas academicas, autoeficacia y estrategias de aprendizaje en el rendimiento de alumnado de secundaria de Galicia y Norte de Portugal

Objetivo. Analizar la determinación y capacidad predictiva de las metas académicas, autoeficacia y estrategias de aprendizaje en el rendimiento académico de alumnos de Educación Primaria y Secundaria de Galicia y Norte de Portugal. Muestra. Integrada por un total de 997 alumnos de 7º de Enseñanza Básica (Portugal) o de 1º de ESO (España). Del total de la muestra 510 eran del norte de Portugal (48% varones), de edades comprendidas entre 10 y 16 años, (media de 12,4 años y desviación típica 0,94 años) y 487 de Galicia (España) (51% varones), de edades comprendidas entre 11 y 15 años, (media de 12,3 años y desviación típica 0,70). Su procedencia es de tipo urbano, si bien la mayoría procede de la periferia de ciudades como Porto, Guimaraes, Braga y Chaves, así como de A Coruña, Ourense y Santiago de Compostela. Instrumento de evaluación. Se ha utilizado la Escala REFEMA (Evaluación de relación familia-escuela y motivaciones académicas), elaborada a partir de la Escala CDPFA (Evaluación de Datos Personales, Familiares y Académicos), en concreto las Subescalas de Metas Académicas y Estrategias de Aprendizaje. Variables. Las variables utilizadas describen las Metas académicas y Autoeficacia y las principales Estrategias de aprendizaje, básicamente cognitivas, que se utilizan en este trabajo. Técnicas de Análisis. Se pretendía conocer la capacidad predictiva de las variables que se señalan en el objetivo general del trabajo. Para ello se utiliza el paquete estadístico SPSS, versión 17.0, realizando un análisis de regresión lineal múltiple en el que las variables independientes son las referidas a las Metas académicas de Aprendizaje, de Rendimiento, valoración social Resultados. Apuntan, en la muestra de alumnado de Portugal, hacia las Metas académicas de aprendizaje y las Metas de autoeficacia (capacidad percibida de autorregulación del aprendizaje) como factores determinantes positivos del rendimiento académico, mientras que son las Metas de valoración social y las Estrategias superficiales de aprendizaje (de ansiedad ante los exámenes) las que tienen una determinación negativa sobre el rendimiento escolar con efectos de inhibición hacia el aprendizaje. En la muestra de Galicia se observa que la variable que mantiene efectos positivos sobre el rendimiento es la Autoeficacia Académica (capacidad percibida de autorregulación del aprendizaje), mientras que son las Estrategias de aprendizaje de Organización y Comprensión las que poseen efectos positivos y significativos sobre el rendimiento y desempeño escolar. Al contrario, las Metas de Valoración social, las Metas de aprendizaje y las Estrategias superficiales (de ansiedad ante los exámenes) son otras tantas variables que mantienen efectos significativos, pero negativos y de inhibición motivacional sobre el rendimiento y desempeño escolar.Grupo de Investigación en Psicoloxia do desenvolvemento e da aprendizaxe escolar (GIPDAE)CERXunta de Galicia - Consellería de Educación e Ordenación Universitaria (Secretaria Xeral)Ministerio de Educación y CienciaBase de Datos - ISOCFundación Universidade da CoruñaAyuntamiento de La Coruña - Concello de A CoruñaUniversidade do Minh

Pseudoaneurisma femoropoplíteo pós-traumático em doente alérgico às heparinas

Os pseudoaneurismas pós-traumáticos da artéria femoral são uma complicac¸ão rara. Normalmente têm causa iatrogénica e aparecem de imediato. Menos frequentemente surgem numa fase tardia e costumam estar relacionados com traumatismos, cirurgia ortopédica, lesões ósseas, infec¸ões, etc. Este artigo apresenta o caso de um paciente alérgico àheparina com pseudoaneurisma da artéria femoral superficial e primeira parte da artéria poplítea, secundário ao traumatismo remoto de uma extremidade com sérias deformidades como sequela. Realizamos cirurgia convencional com abordagem posterior e obtivemos um resultado e evoluc¸ão satisfatórios

Pseudoaneurisma femoropoplíteo pós-traumático em doente alérgico às heparinas

Os pseudoaneurismas pós-traumáticos da artéria femoral são uma complicação rara. Normalmente têm causa iatrogénica e aparecem de imediato. Menos frequentemente surgem numa fase tardia e costumam estar relacionados com traumatismos, cirurgia ortopédica, lesões ósseas, infeções, etc. Este artigo apresenta o caso de um paciente alérgico àheparina com pseudoaneurisma da artéria femoral superficial e primeira parte da artéria poplítea, secundário ao traumatismo remoto de uma extremidade com sérias deformidades como sequela. Realizamos cirurgia convencional com abordagem posterior e obtivemos um resultado e evoluc¸ão satisfatórios