298 research outputs found

    Analysis of model sheet pile walls with plastic hinges

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    As part of a wider project investigating the implications of Eurocode 3, Design of steel structures – Part 5: Piling, centrifuge testing of model sheet pile walls and numerical back-analysis were undertaken. The aims of the study were to examine the effect of plastic hinging on embedded retaining wall response, and to verify calculation methods for use in wider generic calculations. Physical modelling of an anchored wall embedded in dry sand was undertaken. In some of the tests a hinge zone was introduced into the wall in order to reproduce a kinematic mechanism similar to that associated with plastic hinge formation. Finite-element calculations were undertaken using Lade's double-hardening cap model to represent the behaviour of the sand. The analyses generally yielded good accord with the test results in many aspects of the wall behaviour. In terms of the aims of the testing, the study of the effect of plastic hinging was not realistically captured, because the hinge zone was present from the outset of the test, allowing greater than expected earth pressure redistribution, and because the moment–curvature characteristic of the notched wall did not reproduce the buckling effects seen in the plastic bending response of steel sheet piles. On the other hand, the satisfactory agreement between the test observations and the numerical predictions gave confidence in the use of the calculation model for further generic calculations using realistic steel sheet pile moment–plastic curvature characteristics. </jats:p

    Does Scientific Progress Consist in Increasing Knowledge or Understanding?

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    Bird argues that scientific progress consists in increasing knowledge. Dellsén objects that increasing knowledge is neither necessary nor sufficient for scientific progress, and argues that scientific progress rather consists in increasing understanding. Dellsén also contends that unlike Bird’s view, his view can account for the scientific practices of using idealizations and of choosing simple theories over complex ones. I argue that Dellsén’s criticisms against Bird’s view fail, and that increasing understanding cannot account for scientific progress, if acceptance, as opposed to belief, is required for scientific understanding

    Design and development of a novel upper-limb cycling prosthesis

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    The rise in popularity of the Paralympics in recent years has created a need for effective, low-cost sports-prosthetic devices for upper-limb amputees. There are various opportunities for lower-limb amputees to participate in cycling; however, there are only few options for those with upper-limb amputations. If the individual previously participated in cycling, a cycling-specific prosthesis could allow these activities to be integrated into rehabilitation methods. This article describes the processes involved with designing, developing and manufacturing such a prosthesis. The fundamental needs of people with upper-limb amputation were assessed and realised in the prototype of a transradial terminal device with two release mechanisms, including a sliding mechanism (for falls and minor collisions) and clamping mechanism (for head-on collisions). The sliding mechanism requires the rider to exert approximately 200 N, while the clamping mechanism requires about 700 N. The force ranges can be customised to match rider requirements. Experiments were conducted in a controlled environment to demonstrate stability of the device during normal cycling. Moreover, a volunteer test-rider was able to successfully activate the release mechanism during a simulated emergency scenario. The development of this prosthesis has the potential to enable traumatic upper-limb amputees to participate in cycling for rehabilitation or recreation

    'Word from the street' : when non-electoral representative claims meet electoral representation in the United Kingdom

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    Taking the specific case of street protests in the UK – the ‘word from the street’– this article examines recent (re)conceptualizations of political representation, most particularly Saward’s notion of ‘representative claim’. The specific example of nonelectoral claims articulated by protestors and demonstrators in the UK is used to illustrate: the processes of making, constituting, evaluating and accepting claims for and by constituencies and audiences; and the continuing distinctiveness of claims based upon electoral representation. Two basic questions structure the analysis: first, why would the political representative claims of elected representatives trump the nonelectoral claims of mass demonstrators and, second, in what ways does the ‘perceived legitimacy’ of the former differ from the latter

    What is theoretical progress of science?

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    The epistemic conception of scientific progress equates progress with accumulation of scientific knowledge. I argue that the epistemic conception fails to fully capture scientific progress: theoretical progress, in particular, can transcend scientific knowledge in important ways. Sometimes theoretical progress can be a matter of new theories ‘latching better onto unobservable reality’ in a way that need not be a matter of new knowledge. Recognising this further dimension of theoretical progress is particularly significant for understanding scientific realism, since realism is naturally construed as the claim that science makes theoretical progress. Some prominent realist positions (regarding fundamental physics, in particular) are best understood in terms of commitment to theoretical progress that cannot be equated with accumulation of scientific knowledge

    Shielding Children: The European Way

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    The Internet crosses physical borders, and carries with it both its promises and its harms to many different countries and societies. These countries thus share the same technology, but they do not necessarily share the same set of values or legal system. This Article compares the legal response in the United States and in Europe to one important issue: the exposure of children to certain materials, which are deemed harmful to them but not harmful to adults. This US-European comparison, in which the experience in the United Kingdom serves as a leading example, illustrates the traits of various kinds of regulation of the new media: public ordering (direct and indirect), private ordering, and ordering by code, i.e., by technological means. The authors examine the various kinds of regulation and their constitutional meaning. The US opted mostly for a direct legal attack on the material which is harmful to children, an approach which thus far failed the judicial test, due to the limitations it imposes on freedom of speech of adults. While the European framework allows greater balancing between expression rights and competing interests, the European response has not been to follow the direct restrictions attempted in the US. Instead, accepting the practical difficulties of enforcing direct restrictions, the emerging legal response in European countries has been a market-based solution, guided by a legal framework that fosters self-regulation. The Article considers the reasons for adopting the approach of self-regulation and the impact that such methods of control have on freedom of expression. In particular, the Article examines the relationship of such controls with the communitarian approach advocated by Professor Etzioni

    A Qualitative Analysis of Counsellors’ Experiences Working with Individuals Diagnosed with FASD

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    This study used qualitative inquiry guided by phenomenology in effort to make explicit the experiences of three registered psychologists and one registered clinical social worker, who counsel individuals with FASDs. An interview was conducted with each participant and then each interview was analyzed for themes and subthemes. The analysis resulted in three primary themes: Thinking Outside the Box, Finding a Foothold and Finding the Fit Between Tools and The Client. The results of this study indicate that counselling an individual with an FASD is challenging and requires flexibility on the part of the therapist. Finally, the results of this present study will be situated within the literature discussing other noncounselling methods used in working with individuals with an FASD and the literature pertaining to counselling individuals with other disabilities

    Lines of Descent: Kuhn and Beyond

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    yesThomas S. Kuhn is famous both for his work on the Copernican Revolution and his ‘paradigm’ view of scientific revolutions. But Kuhn later abandoned the notion of paradigm (and related notions) in favour of a more ‘evolutionary’ view of the history of science. Kuhn’s position therefore moved closer to ‘continuity’ models of scientific progress, for instance ‘chain-of-reasoning’ models, originally championed by D. Shapere. The purpose of this paper is to contribute to the debate around Kuhn’s new ‘developmental’ view and to evaluate these competing models with reference to some major innovations in the history of cosmology, from Copernicanism to modern cosmology. This evaluation is made possible through some unexpected overlap between Kuhn’s earlier discontinuity model and various versions of the later continuity models. It is the thesis of this paper that the ‘chain-of-reasoning’ model accounts better for the cosmological evidence than both Kuhn’s early paradigm model and his later developmental view of the history of science
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