3,265 research outputs found

    Las fiestas de San Froilán, en Lugo

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    En número dedicado a: Lug

    Servicio de seguridad combinable mediante técnicas de orquestación de servicios

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    En los últimos años, la seguridad en redes y servicios ha evolucionado de manera exponencial debido al crecimiento de dispositivos conectados a Internet. Con el avance de las nuevas tecnologías es imprescindible dotar a cualquier servicio o dispositivo de la seguridad adecuada dado que éstos se pueden ver afectados por diversas amenazas tales como la accesibilidad, la integridad, la identidad del usuario, la disponibilidad y la confidencialidad de los datos. Cuando se trata de comunicaciones, la seguridad cobra especial importancia dado que los datos enviados a través de la red pueden ser interceptados por un agente no autorizado y utilizarlos para su propio beneficio o alterar su contenido. Para contrarrestar estos ataques, se han definido unos servicios de seguridad como son, por ejemplo, la confidencialidad y la integridad de los datos. Existen diversos mecanismos de seguridad que implementan estos servicios los cuales se apoyan en técnicas criptográficas. Desde el comienzo de las primeras comunicaciones se han desarrollado diferentes técnicas criptográficas que han ido evolucionando a la vez que éstas. La primera de estas técnicas conocida fue escítala lacedemonia en el siglo V a.C. Los éforos espartanos, que eran los que utilizaban dicha técnica, escribían el mensaje en una cinta de cuero o papiro enrollada en una vara de grosor variable. A continuación desenrollaban la cinta y la enviaban al receptor. Sí el mensaje era interceptado solo podrían leer una pila de letras sin sentido. Sí el mensaje llegaba al receptor, éste enrollaría de nuevo la cinta en una vara del mismo grosor que lo hizo el emisor y leería el mensaje. En este proyecto de fin de grado se va a realizar un estudio del estado de arte sobre mecanismos de seguridad para posteriormente diseñar e implementar un componente de seguridad que ofrecerá los servicios citados. Dicho componente se integrará en el sistema del proyecto Europeo I3RES como un servicio más de los definidos dentro del propio proyecto. Los servicios de seguridad que requiere el proyecto I3RES, y por tanto los que ofrecerá el componente, son los de autenticación, integridad, no repudio y confidencialidad. El proyecto I3RES basa su sistema en una arquitectura distribuida por lo que es necesario realizar un estudio del estado del arte sobre dichas arquitecturas para el correcto despliegue del componente en el sistema. Actualmente, la mayoría de los sistemas mantienen una arquitectura distribuida. Este tipo de arquitectura conecta distintos equipos y dispositivos que están separados físicamente mediante una red llamada middleware. Estos equipos trabajan conjuntamente para implementar un conjunto de servicios. En el documento presente se tratan todos los temas anteriormente citados y se detalla el componente a desarrollar así como las correspondientes pruebas de validación y las conclusiones obtenidas. ABSTRACT. Security in networks and services have been extensively developed in last decades due to the arising of multiple devices connected to Internet. Advances in new technologies enhanced the necessity of security requirements to in order to avoid several warnings such as accessibility, integrity, user identity, availability, and confidentiality of our data. In terms of communications, security is crucial due to data could be intercepted on Internet by non-authorised agents which could use them or even alter their content. In order to avoid this warnings, security services have been defined such as data confidentiality and integrity. There is several security mechanism which implement this services based on cryptographic techniques. In parallel to the evolution of communication, cryptographic technics have been also developed with. The most ancient of technics was described in s. V b.C called escitala lacedemonia. Spartan ephorts, which extensively used this method, were used to write messages on the surface of a leather tape or papyri which were rolled on a rod. Next, they unrolled the tape and they sent to the receptor. Whether the message was intercepted they just would be able to read a mess of letters without sense. On the other hand, if the message arrive to the proper receptor, he roll the tape again in a rod with similar anchor of the transmitter one which leads to the adequate read. This Degree Project is focused on an analysis of the state of art about security mechanism together with a design and implement of a security component which offered the services mentioned. This component will be integrated within the European project I3RES as one of the security elements defined inside the project. The security components required in project I3REs are authentication, integrity and non-repudiation will be offered by the designed component as well. Nowadays, the most of the systems maintain a distributed architecture. This type of architecture connect several devices which are physically separated by a network called middleware. This equipment work altogether to implement a set of services. This document is focused on all the topics mentioned as well as the details of the component developed together with the validation tests required and the conclusions obtained

    Rheological and hydration characterization of calcium sulfoaluminate cement pastes

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    Calcium sulfoaluminate (CSA) cements are currently receiving a lot of attention because their manufacture produces less CO2 than ordinary Portland cement (OPC). However, it is essential to understand all parameters which may affect the hydration processes. This work deals with the study of the effect of several parameters, such as superplasticizer (SP), gypsum contents (10, 20 and 30 wt%) and w/c ratio (0.4 and 0.5), on the properties of CSA pastes during early hydration. This characterization has been performed through rheological studies, Rietveld quantitative phase analysis of measured x-ray diffraction patterns, thermal analysis and mercury porosimetry for pastes, and by compressive strength measurements for mortars. The effect of the used SP on the rheological properties has been established. Its addition makes little difference to the amount of ettringite formed but strongly decreases the large pore fraction in the pastes. Furthermore, the SP role on compressive strength is variable, as it increases the values for mortars containing 30 wt% gypsum but decreases the strengths for mortars containing 10 wt% gypsum.This work has been supported by Spanish Ministry of Science and Innovation through MAT2010- 16213 research grant, which is co-funded by FEDER, and Ramón y Cajal Fellowship (RYC-2008- 03523)

    Hydration studies of calcium sulfoaluminate cements blended with fly ash

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    The main objective of this work is to study the hydration and properties of calciumsulfoaluminate cement pastes blended with fly ash (FA) and the corresponding mortars at different hydration ages. Laboratory X-ray powder diffraction, rheological studies, thermal analysis, porosimetry and compressive strength measurements were performed. The analysis of the diffraction data by Rietveld method allowed quantifying crystalline phases and overall amorphous contents. The studied parameters were: i) FA content, 0, 15 and 30 wt.%; and ii) water addition, water-to-CSA mass ratio (w/CSA = 0.50 and 0.65), and water-to-binder mass ratio (w/b = 0.50). Finally, compressive strengths after 6 months of 0 and 15 wt.% FA [w/CSA = 0.50] mortars were similar: 73 ± 2 and 72 ± 3 MPa, respectively. This is justified by the filler effect of the FA as no strong evidences of reactivity of FA with CSA were observed. These results support the partial substitution of CSA cements with FA with the economic and environmental benefitsThis work has been supported by Spanish MINECO through MAT2010-16213 research grant, which is co-funded by FEDER. I. Santacruz thanks a Ramón y Cajal fellowship, RYC-2008-03523

    La importancia de la determinación del sexo y la estimación de la edad en paleopatología: sobre un caso con lesiones sugerentes de etiología metastásica

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    X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

    Estudio de los marcadores de actividad de los restos recuperados de la Mezquita del Cristo de la Luz (Toledo)

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    X Congreso Nacional de Paleopatología. Univesidad Autónoma de Madrid, septiembre de 200

    Effect of calcium sulfate source on the hydration of calcium sulfoaluminate eco-cement

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    The availability of cements, including eco-cements, with tailored mechanical properties is very important for special applications in the building industry. Here we report a full study of the hydration of calcium sulfoaluminate eco-cements with different sulfate sources (gypsum, bassanite and anhydrite) and two water/cement ratios (0.50 and 0.65). These parameters have been chosen because they are known to strongly modify the mechanical properties of the resulting mortars and concretes. The applied multitechnique characterization includes: phase assemblage by Rietveld method, evolved heat, conductivity, rheology, compressive strength and expansion/retraction measurements. The dissolution rate of the sulfate sources is key to control the hydration reactions. Bassanite dissolves very fast and hence the initial setting time of the pastes and mortars is too short (20 min) to produce homogeneous samples. Anhydrite dissolves slowly so, at 1 hydration-day, the amount of ettringite formed (20 wt%) is lower than that in gypsum pastes (26 wt%) (w/c = 0.50), producing mortars with lower compressive strengths. After 3 hydration-days, anhydrite pastes showed slightly larger ettringite contents and hence, mortars with slightly higher compressive strengths. Ettringite content is the chief parameter to explain the strength development in these eco-cements.Universidad de Málaga. Campus de Excelencia Interncaional Andalucía Tech

    Promoción de estilos de vida saludables en trabajadores administrativos de una institución técnica

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    An investigation was developed under the foundations, theoretical - normative, of Safety and Health at Work, with the objective of formulating an intervention proposal for the promotion, maintenance of health and prevention of common non-communicable diseases, based on the lifestyles of the human talent of an institution of Distance Education and Training for work, this project was based on the positivist and phenomenological epistemological conceptions, considering a mixed study, first a diagnosis was made and later, the promotion program was elaborated. of healthy lifestyles, the results indicated a negative prevalence in the healthy lifestyles of said population, as well as associations between the variables with the presence of non-communicable diseases, in conclusion it is considered that inadequate lifestyles contribute to the appearance of non-communicable diseases, for which it is necessary to continue designing activities focused on health promotion and disease prevention in the workplace to support the promotion of better conditions for the country's workers.Se desarrolló una investigación bajo los fundamentos, teóricos – normativos, de la Seguridad y Salud en el Trabajo, con el objetivo de formular una propuesta de intervención para la promoción, mantenimiento de la salud y prevención de las enfermedades comunes no transmisibles, basada en los estilos de vida del talento humano de una institución de Educación a Distancia y Formación para el trabajo, este proyecto se basó en las concepciones epistemológicas positivistas y fenomenológicas, planteándose un estudio mixto, primero se realizó un diagnóstico y posteriormente, se elaboró el programa de promoción de estilos de vida saludables, los resultados indicaron una prevalencia negativa en los estilos de vida saludables de dicha población, así como asociaciones entre las variables con la presencia de enfermedades no transmisibles, en conclusión se considera, que los estilos de vida inadecuados contribuyen con la aparición de enfermedades no transmisibles, por lo cual se debe seguir diseñando actividades enfocadas a la promoción de la salud y prevención de las enfermedades en el ámbito laboral para apoyar el fomento de mejores condiciones para los trabajadores del país

    Nuclear organization in stress and aging

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    This article belongs to the Special Issue Nuclear Organisation.The eukaryotic nucleus controls most cellular processes. It is isolated from the cytoplasm by the nuclear envelope, which plays a prominent role in the structural organization of the cell, including nucleocytoplasmic communication, chromatin positioning, and gene expression. Alterations in nuclear composition and function are eminently pronounced upon stress and during premature and physiological aging. These alterations are often accompanied by epigenetic changes in histone modifications. We review, here, the role of nuclear envelope proteins and histone modifiers in the 3-dimensional organization of the genome and the implications for gene expression. In particular, we focus on the nuclear lamins and the chromatin-associated protein BAF, which are linked to Hutchinson–Gilford and Nestor–Guillermo progeria syndromes, respectively. We also discuss alterations in nuclear organization and the epigenetic landscapes during normal aging and various stress conditions, ranging from yeast to humans.Work in the M.A.-S. and P.A. laboratories is funded by the Spanish Ministry of Science, Innovation and Universities (BFU2016-79313-P to P.A. & MDM-2016-0687 to P.A. and M.A.-S.), the European Research Council (ERC-2011-StG-281691 to M.A.-S.) and the European Regional Development Fund.Peer reviewe
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