Stochastic homogenization of the laser intensity to improve the irradiation uniformity of capsules directly driven by thousands laser beams

Illumination uniformity of a spherical capsule directly driven by laser beams has been assessed numerically. Laser facilities characterized by ND = 12, 20, 24, 32, 48 and 60 directions of irradiation with associated a single laser beam or a bundle of NB laser beams have been considered. The laser beam intensity profile is assumed super-Gaussian and the calculations take into account beam imperfections as power imbalance and pointing errors. The optimum laser intensity profile, which minimizes the root-mean-square deviation of the capsule illumination, depends on the values of the beam imperfections. Assuming that the NB beams are statistically independents is found that they provide a stochastic homogenization of the laser intensity associated to the whole bundle, reducing the errors associated to the whole bundle by the factor  , which in turn improves the illumination uniformity of the capsule. Moreover, it is found that the uniformity of the irradiation is almost the same for all facilities and only depends on the total number of laser beams Ntot = ND × NB

Fast ignition of inertial fusion targets by laser-driven carbon beams

Two-dimensional simulations of ion beam driven fast ignition are presented. Ignition energies of protons with Maxwellian spectrum and carbon ions with quasimonoenergetic and Maxwellian energy distributions are evaluated. The effect of the coronal plasma surrounding the compressed deuterium-tritium is studied for three different fuel density distributions. It is found that quasi- monoenergetic ions have better coupling with the compressed deuterium-tritium and substantially lower ignition energies. Comparison of quasimonoenergetic carbon ions and relativistic electrons as ignitor beams shows similar laser energy requirements, provided that a laser to quasimonoenergetic carbon ion conversion efficiency around 10% can be achieved.Comment: 8 pages, 10 figures, published in Physics of Plasma

Educación lingüística y desarrollo de competencias en evaluación. Análisis de una experiencia en Magisterio. Language Education and Assessment Skills Development. Analysis of an Experience in Teachers Training.

Presentamos los resultados de un proyecto de innovación docente desarrollado en la asignatura Lengua Española para Maestros de los grados de Educación Infantil y Primaria mediante prácticas educativas y procedimientos evaluativos que buscan promover y maximizar la capacidad de los maestros en formación para regular los propios procesos de aprendizaje, la construcción del conocimiento y el desarrollo de competencias profesionales, entre las que se encuentra la capacidad evaluadora. Mediante un diseño que contempla la auto- y coevaluación, y desde el modelo de evaluación orientada al aprendizaje (EOA), se ha pretendido que el alumnado ganara autonomía en la identificación de problemas, rendimientos y resultados de su aprendizaje lingüístico con objeto de esclarecer y afinar el proceso de enseñanza-aprendizaje de la lengua. Los resultados aportados muestran cuál es el grado de dominio percibido en torno al proceso de evaluación desarrollado a lo largo de los tres últimos cursos académicos. Ello nos permite orientar la enseñanza en el aula universitaria ajustando las condiciones y desarrollo del aprendizaje del español

Design of absolute equation of state measurements in optically thick materials by laser-driven shock waves

Abstract Some aspects of the design of a target for the absolute measurement of Equation-of-State data at pressure of tens of Mbar, in optically thick materials are discussed. In the proposed experiment, a shock wave is generated in a laser-irradiated sample, and the shock velocity and the material velocity behind the shock are simultaneously measured by the optical and X-ray diagnostics. Accurate measurements require the generation of a steady, planar shock, and the detection of the motion of a shocked fluid interface by transverse radiography. One- and two-dimensional numerical fluid simulations have been performed to optimize beam and target design, in order to fulfil such requirements

Escritura colaborativa en línea. Un estudio de la revisión textual compartida en la formación inicial de maestros

Presentamos, en el marco de los proyectos de innovación de la Universidad de Valencia, el análisis de una experiencia de escritura colaborativa en línea. Desde una perspectiva que reúne las tesis de escritura y evaluación como herramientas para aprender, se aplica una metodología de investigación-acción para el seguimiento de un proceso de aprendizaje colaborativo: escritura individual, con revisión y evaluación compartidas, a través de un diario virtual que recoge las sesiones presenciales de la asignatura Lengua Española para Maestros, de primer curso de las titulaciones de Magisterio. La muestra analizada, perteneciente a dos cursos académicos, corresponde a la actividad de 84 estudiantes, cada uno de los cuales moderó una conversación virtual con una media de 12-16 mensajes de autoría múltiple cada una, que fueron analizados mediante una técnica ad hoc de análisis de contenido. Como conclusiones más destacadas, los resultados han permitido identificar diferencias en el rendimiento asociadas a procesos de coautoría real favoreciendo la aparición de procesos argumentativos y reflexivos, y guía el trabajo de grupo hacia procesos cercanos a los esperados en las comunidades de aprendizaje. Asimismo, este trabajo invita a la reflexión sobre dos aspectos: el seguimiento de los participantes y la entrega de ayudas durante el proceso. The analysis of an online collaborative writing experience is presented, in the framework of the innovation projects of the University of Valencia. From a perspective that brings together the thesis of writing and assessment as tools to learn, an action research methodology is applied to monitor a collaborative learning process: individual writing, with shared review and evaluation, through a virtual diary that collects the face-toface sessions of the Spanish Language for Teachers subject, in the first year of the Teaching degrees. The sample analysed, belonging to two academic courses, corresponds to the activity of 84 students, each of whom moderated a virtual conversation with an average of 12-16 messages each by multiple authorship, which were analysed using an ad hoc technique of content analysis. The most prominent conclusions point at the results allowing for the identification of differences in performance, associated with real co-authorship processes, favouring the appearance of argumentative and reflexive processes, and guiding the group work towards processes closer to those expected in learning communities. Likewise, this work invites reflection on two aspects: the follow-up of the participants and the delivery of aid during the process

Homogeneity of Interspecific Hybrids Between Saccharomyces cerevisiae and Saccharomyces uvarum by Phenotypic and Transcriptional Analysis

Oenological traits, such as temperature profile and production of certain metabolites, were tested for four interspecifc hybrids obtained by"spore to spore" crossing between Saccharomyces cerevisiae and Saccharomyces uvarum strains and uniformity of their inheritance was found. PCR/RFLP analysis of ITS regions was carried out to confirm the hybrid nature of the strains. They showed an additive profile with five bands of the respective 325, 230, 170 and 125 bp. Finally gene expression study was performed by comparative DNA macroarray analysis of the hybrids and the preliminary results showed that the global gene expression patterns of hybrids are remarkably similar to one another. In conclusion, the data obtained by two different approaches, such as metabolic and transcriptomic strategies, suggest a large degree of homogeneity among interspecific hybrids between S. cerevisiae and S. uvarum. Moreover, the uniformity of F1 hybrids advises that the oenological trait inheritance mechanism is highly constant and reproducible

Ignition conditions for inertial confinement fusion targets with a nuclear spin-polarized DT fuel

The nuclear fusion cross-section is modified when the spins of the interacting nuclei are polarized. In the case of deuterium?tritium it has been theoretically predicted that the nuclear fusion cross-section could be increased by a factor d = 1.5 if all the nuclei were polarized. In inertial confinement fusion this would result in a modification of the required ignition conditions. Using numerical simulations it is found that the required hot-spot temperature and areal density can both be reduced by about 15% for a fully polarized nuclear fuel. Moreover, numerical simulations of a directly driven capsule show that the required laser power and energy to achieve a high gain scale as d-0.6 and d-0.4 respectively, while the maximum achievable energy gain scales as d0.9

Predicting management development and learning behaviour in New Zealand SMEs

Despite concern on the part of policy makers to raise managerial capability in SMEs, there is little evidence on the key drivers of owner-manager participation in management development programmes. The authors argue that such participation is poorly understood. The paper develops a predictive model of the drivers of participation in sources of learning by owner-managers. It tests a theoretical model, based on the small firm as a learning organization, which posits that participation is driven by owner-managers\u27 learning orientation and the extent of their belief in self-improvement. The implications of the results are discussed in light of the provision of management development programmes. <br /

An analysis of material consumption culture in the Muslim world

In this paper, we examine the notion of material consumption culture in Islamic societies. We differentiate between institutionalised religion and religion as culture. We contest the Orientalist portrayal of Islam as a fanatic ideology opposed to Western Modernity’s features of secularism, individualism, and pluralism. With reference to the Qur’anic text, we discuss that such qualities are embedded with Islam. We do not interpret the Qur’an from a theological perspective; rather, we seek to demonstrate the possibilities of its multiple interpretations. We argue that, in their everyday life consumption practices, Muslims (re)interpret religious guidelines in different ways and refer to Islam, as a transcendental set of guidelines, to make better sense of their cultural practices in different ways. We summarise our discussion by highlighting the importance of analysing the culture of consumption from the lens of insiders and offer directions for future research