10,088 research outputs found

    Renormalizing Sznajd model on complex networks taking into account the effects of growth mechanisms

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    We present a renormalization approach to solve the Sznajd opinion formation model on complex networks. For the case of two opinions, we present an expression of the probability of reaching consensus for a given opinion as a function of the initial fraction of agents with that opinion. The calculations reproduce the sharp transition of the model on a fixed network, as well as the recently observed smooth function for the model when simulated on a growing complex networks.Comment: 5 pages, 7 figure

    Experimental characterization of the structural response of adobe arches

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    Earth was one of the first construction materials used by mankind and has been used as a building material since ancient times until the present days. Its qualities related to thermal comfort, low cost or simple construction techniques have contributed to such a long tradition throughout the world with several different architectural expressions, integrating the culture and history of each region. With the wide propagation of steel and concrete structures, there has been a general loss of the traditional knowledge in earth construction. This type of construction presents important structural fragilities and requires a special maintenance to preserve its qualities. In order to understand the structural behaviour of this type of structures, the associated construction methods and processes have to be considered. Aveiro University has been developing studies on adobe constructions, with research on the material mechanical characterization, experimental study of the structural behaviour of adobe masonry walls and, more recently, in the development of a detailed survey methodology for the characterization of buildings in Aveiro district. Integrated in these studies, arches with different geometries were built using adobe blocks and traditional construction methods. These arches were tested under different types of vertical loading (distributed symmetrical, distributed non-symmetrical and point load) until collapse. The experimental tests performed reproduce the typical loading conditions of these structures during construction and use. The tests conducted, the results obtained and the main conclusions attained are described in this paper

    Interplay between chiral and axial symmetries in a SU(2) Nambu--Jona-Lasinio Model with the Polyakov loop

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    We consider a two flavor Polyakov--Nambu--Jona-Lasinio (PNJL) model where the Lagrangian includes an interaction term that explicitly breaks the UA(1)_A(1) anomaly. At finite temperature, the restoration of chiral and axial symmetries, signaled by the behavior of several observables, is investigated. We compare the effects of two regularizations at finite temperature, one of them, that allows high momentum quarks states, leading to the full recovery of chiral symmetry. From the analysis of the behavior of the topological susceptibility and of the mesonic masses of the axial partners, it is found in the SU(2) model that, unlike the SU(3) results, the recovery of the axial symmetry is not a consequence of the full recovery of the chiral symmetry. Thus, one needs to use an additional idea, by means of a temperature dependence of the anomaly coefficient, that simulates instanton suppression effects.Comment: 21 pages, 5 figures; PRD versio

    Some properties of two Nambu--Jona-Lasinio -type models with inputs from lattice QCD

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    We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio (PNJL) model at finite temperature and nonzero chemical potential. The calculations are performed in the light and strange quark sectors (uu, dd, ss), which includes the 't Hooft instanton induced interaction term that breaks the axial symmetry, and the quarks are coupled to the (spatially constant) temporal background gauge field. On one hand, a special attention is payed to the critical end point (CEP). The strength of the flavor-mixing interaction alters the CEP location, since when it becomes weaker the CEP moves to low temperatures and can even disappear. On the other hand, we also explore the connection between QCD, a nonlocal Nambu--Jona-Lasinio type model and the Landau gauge gluon propagator. Possible links between the quenched gluon propagator and low energy hadronic phenomenology are investigated.Comment: Contribution to the International Meeting "Excited QCD", Peniche, Portugal, 06 - 12 May 201

    Research-based spin-offs as agents of knowledge dissemination: Evidence from the analysis of innovation networks

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    The paper addresses the role played by research-based spin-offs (RBSOs) as knowledge dissemination mechanisms, through their position in knowledge networks. For this purpose the paper analyses the formal networks established by Portuguese RBSOs, in the context of publicly funded research, technology and precommercial product development projects, and investigates their configuration along two levels. At organisational level, in order to understand whether RBSOs extend their reach beyond the academic sphere; and if they do, whether they connect to organisations located downstream in the knowledge value chain, and which is their position in networks involving both research organisations and other firms. At spatial level, in order to understand whether RBSOs extend their reach beyond the region where they are created, thus potentially acting as connectors between diverse regions. The analysis starts from the population of RBSOs created in Portugal until 2007 (327 firms) and identifies those that have established formal technological relationships, as part of projects funded by all the relevant programmes launched in the period 1993-2012. As a result, the analysis encompasses 192 collaborative projects and involves 82 spin-offs and 281 partners, of which only 20% are research organisations, the remaining being other firms and a variety of other downstream organisations. The results, although still preliminary, provide some insights into the knowledge networking behaviour of the RBSOs. As expected, research organisations are a central actor in spin-offs’ networks, being the sole partner for some of them. But half of the RBSOs have moved beyond the academic sphere, being frequently a central element in tripartite technological relationships between research and other organisations, and occupying an intermediation position in the network, thus potentially acting as facilitators in knowledge circulation and transformation. Also as expected, RBSOs are predominantly located in the main metropolitan areas and tend to relate with organisations similarly located. But while geographical proximity emerges as important in the choice of partners, in about half of the cases, RBSOs knowledge networks have extended beyond regional boundaries. Given their central position in the network, this suggests a role as connectors across regions that will be explored in subsequent research.info:eu-repo/semantics/publishedVersio

    Inter-industrial relationships driving the blue economy industrial transformation

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    The “Blue Economy” is considered one of the drivers of European growth, based on the development of new competences and activities that enable a sustainable exploitation of ocean resources (EC, 2021; Howard, 2018). Strategies and policies were formulated, both at the UE and national levels, to address “Blue growth”, combining industrial growth objectives with sustainability concerns. These strategies have targeted a broad variety of actors engaged in ocean-related activities, namely companies from established and new industries, and have promoted the development of new transversal technologies through the support of research and innovation (Sousa et al, 2020; EC, 2012).info:eu-repo/semantics/publishedVersio

    Interoperability between information systems concerning electronic records of patients

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    The problematic over the interoperation between institutions in underdeveloped countries always presents good opportunities for science to contribute to substantial improvements in the real-world issues. The basic support systems such as the health institutions are among the ones that can most benefit from scientific advances. This paper reports an analysis done over the interoperability between health institutions, specifically regarding the interaction between medical centres and clinical laboratories where the main interoperability instrument is the patient record. This research was validated with a real practical use case that is presented in this paper. In order to make the information stored in different software applications of the national health system (SIS), more specifically in the Dr. Ayres de Menezes hospital, in the country of São Tomé and Príncipe, interoperable with the information systems of the clinical laboratories that support the hospital, two different applications were developed (Patient Management System and Clinical Analysis Laboratory Management System) to implement the interoperability between them. The Patient Management application requests medical exams from your Medical Appointment dashboard. The second application receives the exam request and after exams are processed and validated, the second system sends the result to the requesting application. To make the interoperability service effective, the SOAP protocol was used, which allowed the exchange of information synchronously between these two applications, allowing for faster transactions of patients' pathological data, and greater confidentiality of this same information.info:eu-repo/semantics/acceptedVersio

    Encontro de Trypanosoma forattinii Coutinho & Pattoli em roedores de Trinidad

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    Recovery of Trypanosoma forattinii from natural infected Oryzomys capito velutinus from Trinidad, is reported. Negative results were obtained with attempts to infect experimentally, several laboratories animals, silvatyc rodents of the same ecological area and several species of triatomids bugs. Positive results were obtained only by using O. capito velutinus born in laboratory.Relata-se o encontro de Trypanosoma forattinii, em exemplares de Oryzomys capito velutinus de Trinidad. Tentativas de isolamento em meio de NNN e de inoculação experimental em animais de laboratório, foram completamente negativas. Resultados positivos foram obtidos com inoculação de O. capito velutinus criados em laboratórios. As tentativas de infectar triatomíneos e roedores silvestres da mesma área foram igualmente negativas
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