452 research outputs found

    Modality, Potentiality and Contradiction in Quantum Mechanics

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    In [11], Newton da Costa together with the author of this paper argued in favor of the possibility to consider quantum superpositions in terms of a paraconsistent approach. We claimed that, even though most interpretations of quantum mechanics (QM) attempt to escape contradictions, there are many hints that indicate it could be worth while to engage in a research of this kind. Recently, Arenhart and Krause [1, 2, 3] have raised several arguments against this approach and claimed that, taking into account the square of opposition, quantum superpositions are better understood in terms of contrariety propositions rather than contradictory propositions. In [17] we defended the Paraconsistent Approach to Quantum Superpositions (PAQS) and provided arguments in favor of its development. In the present paper we attempt to analyze the meanings of modality, potentiality and contradiction in QM, and provide further arguments of why the PAQS is better suited, than the Contrariety Approach to Quantum Superpositions (CAQS) proposed by Arenhart and Krause, to face the interpretational questions that quantum technology is forcing us to consider.Comment: Published in: New Directions in Paraconsistent Logic, J-Y B\'eziau M. Chakraborty & S. Dutta (Eds.), Springer, in press. arXiv admin note: text overlap with arXiv:1404.518

    On the complexity of task allocation

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    Fatigue analysis-based numerical design of stamping tools made of cast iron

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    This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the S–N curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (S–N) curves for this material is determined at room temperature under push pull loading with different load ratios R0σmin/σmax0−2, R0−1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important

    Trauma-related dispatch criteria for Helicopter Emergency Medical Services in Europe

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    Introduction: Helicopter Emergency Medical Services (HEMS) are used worldwide in order to provide potentially life-saving pre-hospital medical support to trauma patients at the accident scene. It is currently unclear how much overlap exists regarding the number and type of dispatch criteria used by individual HEMS organisations. The aim of the current study was to provide an overview of dispatch criteria for trauma cases used by HEMS organisations within Europe, and search for similarities and differences, between countries and HEMS stations. Materials and methods: HEMS dispatch criteria related to trauma care were obtained from the literature and divided into four groups of criteria and processed in a questionnaire. HEMS providing organisations were identified and contacted by telephone and via email. Results: Fifty-five of the 65 organisations (85%) that were contacted completed the questionnaire. The criteria "Fall from height", "Lengthy extrication and significant injury" and "Multiple casualty incidents" were used most frequently. Criteria from the subgroup "Patient Characteristics - Co-morbidities and Age" were used the least. In 44 of the organisations the Central Dispatch Centre (CDC) was primarily responsible for HEMS dispatch. Conclusion: This overview demonstrates the lack of uniformity in the use of dispatch criteria for trauma assistance on a national and international level. Furthermore, the activation of HEMS is not only depending on dispatch criterion protocols, but is also influenced by organisational factors like the education of the dispatcher, the training of the EMS personnel, the familiarity with the dispatch criteria, and the responses of bystanders. Future research should aim to identify a general set of criteria with the highest discriminating potential

    Validity of helicopter emergency medical services dispatch criteria for traumatic injuries: A systematic review

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    Objective. This review provides an overview of the validity of Helicopter Emergency Medical Services (HEMS) dispatch criteria for severely injured patients. Methods. A systematic literature search was performed. English written and peer-reviewed publications on HEMS dispatch criteria were included. Results. Thirty-four publications were included. Five manuscripts discussed accuracy of HEMS dispatch cr

    Dreaming of drams: Authenticity in Scottish whisky tourism as an expression of unresolved Habermasian rationalities

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    In this paper, the production of whisky tourism at both independently owned and corporately owned distilleries in Scotland is explored by focusing on four examples (Arran, Glengoyne, Glenturret and Bruichladdich). In particular, claims of authenticity and Scottishness of Scottish whiskies through commercial materials, case studies, website-forum discussions and 'independent' writing about such whisky are analysed. It is argued that the globalisation and commodification of whisky and whisky tourism, and the communicative backlash to these trends typified by the search for authenticity, is representative of a Habermasian struggle between two irreconcilable rationalities. This paper will demonstrate that the meaning and purpose of leisure can be understood through such explorations of the tension between the instrumentality of commodification and the freedom of individuals to locate their own leisure lives in the lifeworld that remains. © 2011 Taylor & Francis

    Carnot cycle for an oscillator

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    Carnot established in 1824 that the efficiency of cyclic engines operating between a hot bath at absolute temperature ThotT_{hot} and a bath at a lower temperature TcoldT_{cold} cannot exceed 1−Tcold/Thot1-T_{cold}/T_{hot}. We show that linear oscillators alternately in contact with hot and cold baths obey this principle in the quantum as well as in the classical regime. The expression of the work performed is derived from a simple prescription. Reversible and non-reversible cycles are illustrated. The paper begins with historical considerations and is essentially self-contained.Comment: 19 pages, 3 figures, sumitted to European Journal of Physics Changed content: Fluctuations are considere
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