Procés de fabricació de paper per ondular a partir de paperot (paper recuperat)

El disseny d’aquest procés comporta una sèrie d’etapes necessàries per al tractament del paperot i la fabricació del producte desitjat ( paper per ondular). La fàbrica on es produeix el paper per ondular es divideix en les diferents seccions: preparació de pastes, secció humida de la màquina de paper, secció seca de la màquina de paper, zona de acabat i zona de tractament d’aigua. En la zona de preparació de pastes ,es produeix la desintegració del paperot i la neteja dels contaminats que conté . A continuació, a la zona humida de la màquina de paper, es procedeix a la formació de la fulla i es premsa posteriorment. En la zona seca, es produeix el secat del paper mitjançant una bateria de assecadors, que proporciona una sequedat al paper de l’ordre del 90-95%. Un cop surt el paper dels assecadors, passa per la llisa i a continuació, per la pope (on s’enrotlla el paper en forma de bobines). Les bobines mare que surten de la màquina de paper i són enrotllades a la pope, han de tallar-se en bobines més petites ,segons la mida requerida pel client ( aquesta operació es produeix a la bobinadora). Un cop formada la bobina, passa per una retractiladora on la bobina s’embala amb plàstic. A la zona de tractament d’aigües, hi ha una unitat de flotació que permet recuperar les fibres de l’aigua blanca i reutilitzar-les en el procés, així com l’aigua blanca és recirculada cap al pulper. D’aquesta manera es permet l’aprofitament de l’aigua blanca en el pulper i l’aigua que surtclarificada, s’aprofita en els ruixadors de la màquina de paper

Effects of wet/dry-cycling and plasma treatments on the properties of flax nonwovens intended for composite reinforcing

Producción CientíficaThis research analyzes the effects of different treatments on flax nonwoven (NW) fabrics which are intended for composite reinforcement. The treatments applied were of two different kinds: a wet/dry cycling which helps to stabilize the cellulosic fibers against humidity changes and plasma treatments with air, argon and ethylene gases considering different conditions and combinations, which produce variation on the chemical surface composition of the NWs. The resulting changes in the chemical surface composition, wetting properties, thermal stability and mechanical properties were determined. Variations in surface morphology could be observed by scanning electron microscopy (SEM). The results of the X-ray photoelectron spectroscopy (XPS) showed significant changes to the surface chemistry for the samples treated with argon or air (with more content on polar groups on the surface) and ethylene plasma (with less content of polar groups). Although only slight differences were found in moisture regain and water retention values (WRV), significant changes were found on the contact angle values, thus revealing hydrophilicity for the air-treated and argon-treated samples and hydrophobicity for the ethylene-treated ones. Moreover, for some of the treatments the mechanical testing revealed an increase of the NW breaking force.Ministerio de Educación y Formación Profesional (grants BIA2014-59399-R and FPU12/05869

Decoding Options for the Symmetric and Asymmetric Turbo-Coded Two-Way Relay Channel

In this paper, we extend our recent work on joint decoding of trellis codes for the two-way relay channel to quaternary decoding of turbo codes and evaluate two approaches for rate adaptation. More specifically, we consider the uplink phase, which has been identified as the bottleneck, and apply a quaternary joint turbo decoder for both packets. For asymmetric channels, we evaluate two methods of adapting the code rate while keeping the standard LTE turbo codes. The first approach applies puncturing which is known in LTE as rate matching and adapts the codeword lengths while the second, less well-known, method reduces the message length and is known as expurgatio

Psychosocial risk and protective factors for the health and well-being of professionals working in emergency and non-emergency medical transport services, identified via questionnaires

Medical transport (MT) professionals are subject to considerable emotional demands due to their involvement in life-or-death situations and their exposure to the serious health problems of their clients. An increase in the demand for MT services has, in turn, increased interest in the study of the psychosocial risk factors affecting the health of workers in this sector. However, research thus far has not distinguished between emergency (EMT) and non-emergency (non-EMT) services, nor between the sexes. Furthermore, little emphasis has been placed on the protective factors involved. The main objective of the present study is to identify any existing differential exposure - for reasons of work setting (EMT and non-EMT) or of gender - to the various psychosocial risk and protective factors affecting the health of MT workers.Descriptive and transversal research with responses from 201 professionals.The scores obtained on the various psychosocial scales in our study - as indicators of future health problems - were more unfavourable for non-EMT workers than they were for EMT workers. Work setting, but not gender, was able to account for these differences.The scores obtained for the different psychosocial factors are generally more favourable for the professionals we surveyed than those obtained in previous samples.The significant differences observed between EMT and non-EMT personnel raise important questions regarding the organization of work in companies that carry out both services at the same time in the same territory. The relationships among the set of risk/protective factors suggests a need for further investigation into working conditions as well as a consideration of the workers' sense of coherence and subjective well-being as protective factors against occupational burnout syndrom

Procés de fabricació de paper per ondular a partir de paperot (paper recuperat)

El disseny d’aquest procés comporta una sèrie d’etapes necessàries per al tractament del paperot i la fabricació del producte desitjat ( paper per ondular). La fàbrica on es produeix el paper per ondular es divideix en les diferents seccions: preparació de pastes, secció humida de la màquina de paper, secció seca de la màquina de paper, zona de acabat i zona de tractament d’aigua. En la zona de preparació de pastes ,es produeix la desintegració del paperot i la neteja dels contaminats que conté . A continuació, a la zona humida de la màquina de paper, es procedeix a la formació de la fulla i es premsa posteriorment. En la zona seca, es produeix el secat del paper mitjançant una bateria de assecadors, que proporciona una sequedat al paper de l’ordre del 90-95%. Un cop surt el paper dels assecadors, passa per la llisa i a continuació, per la pope (on s’enrotlla el paper en forma de bobines). Les bobines mare que surten de la màquina de paper i són enrotllades a la pope, han de tallar-se en bobines més petites ,segons la mida requerida pel client ( aquesta operació es produeix a la bobinadora). Un cop formada la bobina, passa per una retractiladora on la bobina s’embala amb plàstic. A la zona de tractament d’aigües, hi ha una unitat de flotació que permet recuperar les fibres de l’aigua blanca i reutilitzar-les en el procés, així com l’aigua blanca és recirculada cap al pulper. D’aquesta manera es permet l’aprofitament de l’aigua blanca en el pulper i l’aigua que surtclarificada, s’aprofita en els ruixadors de la màquina de paper

On the Threat of Systematic Jamming of GNSS

This paper presents a study of the threat of malicious interference to GNSS and examines the special case where the jamming device is incrementally more sophisticated than a typical always-on interference source. The concept of a systematic jamming attack is considered, where the interference signal is intentionally synchronized with the GNSS signals, with the intention of causing maximum disruption with the minimum power expenditure. Various attack methodologies are examined for the case of a civilian L1 receiver. It is shown that, depending on the attack strategy, the target signal and the target receiver, data-recovery, navigation and timing can be denied to a user with some tens of decibels less average power than a traditional jamming attack. It is further shown that some attacks may be capable to effectively deny some receiver functionality in a subtle manner such that presence of the malicious interference goes undetected. Key signal and receiver features that expose a vulnerability are identified and some means of improving receiver robustness are provided

An iterative model for fractal antennas: application to the Sierpinski gasket antenna

A simple model that explains the behavior of the Sierpinski fractal antenna is presented. This model shows that the multiband behavior of the Sierpinski fractal antenna is a consequence of its fractal nature. The model is applied to predict the behavior of the Sierpinski fractal antenna when the flare angle is modified and its validity is assessed by comparing its predictions with measured dataPeer Reviewe

La educación bilingüe: ¿Una respuesta al Aragón trilingüe?

Frente al progresivo reconocimiento de los derechos de las diferentes minorías lingüísticas del Estado español, en el caso de Aragón no ha sido hasta recientemente que el debate sobre el papel de las lenguas minoritarias ha alcanzado cierta notoriedad. Más concretamente, la reforma del Estatuto de Autonomía aprobada en 2007 establece el mandato de desarrollar una Ley de Cortes que determine las zonas de uso predominante de las lenguas y modalidades propias de la región, así como otros aspectos relativos a su recuperación, promoción o enseñanza. En este contexto, el artículo presenta una taxonomía de los modelos de educación bilingüe y describe los resultados de diversos estudios centrados en el análisis de las actitudes lingüísticas manifestadas por los ciudadanos aragoneses. A partir de ello, se plantea una propuesta de educación bilingüe coherente con el conocimiento acumulado sobre el tema y ajustada a la realidad trilingüe de la Comunidad

La coordinació académica de la Universidad : estrategias para una educación de calidad

El colectivo de profesores implicados en materias de Organización Educativa en la licenciatura de Pedagogía de la Universidad Autónoma Barcelona desarrolla diversas acciones dirigidas a favorecer la calidad de la formación de los estudiantes, a partir de una mayor coordinación en la confección y desarrollo de los programas. Las reuniones de coordinación, el intercambio desarrollado de experiencias, el debate sobre la distribución de contenidos por materias y ciclos, la acotación metodológica mediante fichas o la elaboración de casos para su resolución han sido actuaciones destacadas en los últimos cursos académicos. El presente texto las describe, delimitando también las bases de actuación, el proceso realizado, algunos de los resultados y los productos elaboradosMost lecturers and professors involved in teaching School Management and Education Management courses have been engaged in developing some innovative actions to improve the training quality that we offer to students in the Pedagogy degree at the Autonomous University of Barcelona. These actions are aimed at increasing co-ordination among the teaching staff when designing and implementing the course curricula. Co-ordination meetings, exchanges of teaching experiences, discussions about what, how and when to teach the different contents, in which courses and at what level, methodological issues pointed out through technical description cards or the elaboration of study cases to be solved have become the basis of relevant actions during the last academic years. This paper explains each one of them, and provides useful information about the theoretical background, the process carried out, some of the results obtained, the output and the tools create