Modeling magnetar outbursts: flux enhancements and the connection with short bursts and glitches

The availability of a large amount of observational data recently collected from magnetar outbursts is now calling for a complete theoretical study of outburst characteristics. In this Letter (the first of a series dedicated to modeling magnetar outbursts), we tackle the long-standing open issue of whether or not short bursts and glitches are always connected to long-term radiative outbursts. We show that the recent detection of short bursts and glitches seemingly unconnected to outbursts is only misleading our understanding of these events. We show that, in the framework of the starquake model, neutrino emission processes in the magnetar crust limit the temperature, and therefore the luminosity. This natural limit to the maximum luminosity makes outbursts associated with bright persistent magnetars barely detectable. These events are simply seen as a small luminosity increase over the already bright quiescent state, followed by a fast return to quiescence. In particular, this is the case for 1RXS J1708–4009, 1E 1841–045, SGR 1806–20, and other bright persistent magnetars. On the other hand, a similar event (with the same energetics) in a fainter source will drive a more extreme luminosity variation and longer cooling time, as for sources such as XTE J1810–197, 1E 1547–5408, and SGR 1627–41. We conclude that the non-detection of large radiative outbursts in connection with glitches and bursts from bright persistent magnetars is not surprising per se, nor does it need any revision of the glitches and burst mechanisms as explained by current theoretical models.

Ventilated Stone Veneer: Mechanical Behaviour, Calculation Methodologies, Major Pathologies and Existing Tests

The increase of building pathologies related to the use of stone materials and the use of ventilated stone veneers, requires the reformulation of design concepts in building façades and also the reformulation of the architectural project. The aim of this paper is to identify, analyze and evaluate synthetically building pathologies in stone ventilated façades in order to obtain the main technical conditions to be considered in the architectural design, by interpreting its mechanical behavior and capabilities to prevent such pathologies and to ensure the proper features during the building lifetime. The methodology is based on both laboratory stone tests and in situ tests about construction systems, by analyzing physical and mechanical behavior of the outer layer in relation to other building requirements. The results imply the need of proper sizing, specific quality control and practical application of calculation methods, to control high concentration pressures in ventilated façades by reaching appropriate project solutions. In conclusion, the research about different pathologies of stone ventilated façades, the study of their mechanical behavior, their anchorage and their connection with their constructive aspects, will help to improve the construction quality of the stone ventilated façade in buildings and to enhance the use of natural stone in modern architecture.

GPGPU implementation of growing neural gas: application to 3D scene reconstruction

Self-organising neural models have the ability to provide a good representation of the input space. In particular the Growing Neural Gas (GNG) is a suitable model because of its flexibility, rapid adaptation and excellent quality of representation. However, this type of learning is time-consuming, especially for high-dimensional input data. Since real applications often work under time constraints, it is necessary to adapt the learning process in order to complete it in a predefined time. This paper proposes a Graphics Processing Unit (GPU) parallel implementation of the GNG with Compute Unified Device Architecture (CUDA). In contrast to existing algorithms, the proposed GPU implementation allows the acceleration of the learning process keeping a good quality of representation. Comparative experiments using iterative, parallel and hybrid implementations are carried out to demonstrate the effectiveness of CUDA implementation. The results show that GNG learning with the proposed implementation achieves a speed-up of 6× compared with the single-threaded CPU implementation. GPU implementation has also been applied to a real application with time constraints: acceleration of 3D scene reconstruction for egomotion, in order to validate the proposal.

Quantum Hall effect in gapped graphene heterojunctions

We model the quantum Hall effect in heterostructures made of two gapped graphene stripes with different gaps, Δ1 and Δ2. We consider two main situations, Δ1=0,Δ2≠0, and Δ1=−Δ2. They are different in a fundamental aspect: only the latter features kink states that, when intervalley coupling is absent, are protected against backscattering. We compute the two-terminal conductance of heterostructures with channel length up to 430 nm, in two transport configurations, parallel and perpendicular to the interface. By studying the effect of disorder on the transport along the boundary, we quantify the robustness of kink states with respect to backscattering. Transport perpendicular to the boundary shows how interface states open a backscattering channel for the conducting edge states, spoiling the perfect conductance quantization featured by the homogeneously gapped graphene Hall bars. Our results can be relevant for the study of graphene deposited on hexagonal boron-nitride, as well as to model graphene with an interaction-driven gapped phase with two equivalent phases separated by a domain wall.

Hybrid simulation-optimization based approach for the optimal design of single-product biotechnological processes

In this work, we present a systematic method for the optimal development of bioprocesses that relies on the combined use of simulation packages and optimization tools. One of the main advantages of our method is that it allows for the simultaneous optimization of all the individual components of a bioprocess, including the main upstream and downstream units. The design task is mathematically formulated as a mixed-integer dynamic optimization (MIDO) problem, which is solved by a decomposition method that iterates between primal and master sub-problems. The primal dynamic optimization problem optimizes the operating conditions, bioreactor kinetics and equipment sizes, whereas the master levels entails the solution of a tailored mixed-integer linear programming (MILP) model that decides on the values of the integer variables (i.e., number of equipments in parallel and topological decisions). The dynamic optimization primal sub-problems are solved via a sequential approach that integrates the process simulator SuperPro Designer® with an external NLP solver implemented in Matlab®. The capabilities of the proposed methodology are illustrated through its application to a typical fermentation process and to the production of the amino acid L-lysine.

Antoni Serra, ètica negra des d’un llaüt

En aquest article es traça una panoràmica per les obres de gènere negre d’Antoni Serra. Tot i això, la producció de gènere de Serra no es pot entendre sense tres característiques essencials: les referències al clàssic; la voluntat de testimoniatge del canvi social; i el lligam entre el gènere negre i la història contemporània. L’article també indaga sobre els motius que duen a l’escriptor a interessar-se per aquest gènere literari i el relaciona amb algunes de les eleccions que va haver de prendre l’escriptor: canviar de llengua després d’uns inicis en castellà que li havien comportat els primers èxits i l’elecció de la llengua catalana com una conseqüència més de la lluita antifranquista.

Conocimientos tecnológicos, pedagógicos y disciplinares del profesorado de Primaria

La emergencia de las tecnologías de información y comunicación (TIC) plantea nuevos desafíos educativos al profesorado, a los cuales puede responder desde un modelo de formación coherente. El propósito de este estudio es analizar los conocimientos tecnológicos, pedagógicos y disciplinares del profesorado de Educación Primaria, necesarios para la integración de las TIC en la labor docente. Para ello, se llevó a cabo una investigación con una metodología cuantitativa de carácter no experimental en la que participaron 224 profesores de Educación Infantil y Primaria de la provincia de Alicante. Los resultados mostraron que los docentes poseen mayores conocimientos pedagógicos y disciplinares que tecnológicos, lo que conlleva a escasos conocimientos para la integración de las TIC en la labor docente. Se constataron, además, diferencias significativas entre el género y los años de experiencia docente, y la relación entre el uso lúdico de la tecnología y los conocimientos sobre sus aspectos fundamentales. Según los resultados obtenidos, se corrobora la necesidad de una alfabetización digital del profesorado abordada no solo desde una formación tecnológica, sino también pedagógica y disciplinar de forma global. Ello responde al modelo TPACK (Technological, Pedagogical and Content Knowledge), el cual se contempla como un marco de referencia a tener en cuenta por lo que respecta al desarrollo profesional del profesorado y su vinculación a los procesos de enseñanza-aprendizaje en el aula donde las TIC estén presentes.

Evolución de la Ley de Directrices y Bases de la Ley de Educación Nacional Law - nº 5.692/1971 la enfermería profesional en Brasil

A garantia da memória histórica do ensino em nível profissionalizante em enfermagem, na década de 1970, foi o objeto dessa investigação. Teve como objetivos descrever e analisar o contexto sócio-político e as circunstâncias históricas em que a Lei nº 5.692, de 12 de agosto de 1971, das Diretrizes e Bases da Educação Nacional, foi promulgada, bem como discutir as mudanças e desdobramentos dessa no ensino profissionalizante em enfermagem. Trata-se de estudo descritivo, qualitativo, exploratório e de natureza histórico-social, com base em análise documental. Optou-se pela Micro-história para dar sustentação teórica à discussão dos resultados dessa investigação, pois a análise dos documentos históricos, sob o prisma de que, embora não seja possível enxergar a sociedade inteira a partir de um fragmento social, é possível enxergar algo da realidade social que envolve o fragmento humano examinado. A delimitação das fontes históricas do estudo compreende o Acervo do Arquivo Histórico da Associação Brasileira de Enfermagem - Seção São Paulo; o Acervo documental sobre a ABEn/SP, existente no Centro Histórico Cultural da Enfermagem Ibero-Americana da Escola de Enfermagem da USP e a Série Documenta do Ministério da Educação e Cultura. A partir dessa LDB nº 5.692/71, o ensino de Enfermagem foi totalmente integrado ao sistema nacional de Educação e sua promulgação ocorreu durante a Ditadura Militar e a ideologia do “milagre econômico”. De acordo com essa ideologia, o sistema educacional brasileiro deveria adequar-se ao modelo econômico desenvolvimentista, com treinamento de pessoal de nível técnico, visando aumentar e baratear os recursos humanos para o trabalho. A ABEn, como entidade representativa dos interesses políticos e ideológicos dos profissionais da área, liderava os debates sobre as questões da formação dos recursos humanos na enfermagem, sendo que na década de 70 mais da metade do contingente de enfermagem era majoritariamente sem formação específica. Também por conta dessa realidade, houve iniciativas governamentais para tentar reverter essa situação. Apesar das questões do ensino da enfermagem não se encontrarem explicitadas no texto da LDB nº 5.692/71, os resultados deste trabalho revelaram que a legislação estudada teve desdobramentos nas decisões políticas no âmbito do ensino profissionalizante e, consequentemente, impactou sobre a formação dos profissionais de enfermagem.