69,562 research outputs found
The âSticky Elasticaâ: Delamination blisters beyond small\ud deformations
We consider the form of an elastic loop adhered to a rigid substrate: the âsticky Elasticaâ. In contrast to previous studies of the shape of delamination âblistersâ, the theory developed accounts for deflections with large slope (i.e. geometrically nonlinear). Starting from the classical Euler Elastica we provide numerical results for the dimensions of such blisters for a variety of end-end confinements and develop asymptotic expressions that reproduce these results well up to the point of self-contact. Interestingly, we find that the width of such blisters does not grow monotonically with increased confinement. Our theoretical predictions are confirmed by simple desktop experiments and suggest a new method for the measurement of the elastocapillary length for deformations that cannot be considered small
Switch on, switch off: stiction in nanoelectromechanical switches
We present a theoretical investigation of stiction in nanoscale electromechanical contact switches. We develop a mathematical model to describe the deflection of a cantilever beam in response to both electrostatic and van der Waals forces. Particular focus is given to the question of whether adhesive van der Waals forces cause the cantilever to remain in the âONâ state even when the electrostatic forces are removed. In contrast to previous studies, our theory accounts for deflections with large slopes (i.e. geometrically nonlinear). We solve the resulting equations numerically to study how a cantilever beam adheres to a rigid electrode: transitions between free, âpinnedâ and âclampedâ states are shown to be discontinuous and to exhibit significant hysteresis. Our findings are compared to previous results from linearized models and the implications for nanoelectromechanical cantilever switch design are discussed
The sensitivity of Graphene âSnap-throughâ to substrate\ud geometry
We study theoretically the deposition of Few Layer Graphene sheets onto a grooved substrate incorporating adhesion between substrate and sheet. We develop a model to understand the equilibrium of the sheet allowing for partial conformation of sheet to substrate. This model gives new insight into recent observations of âsnap-throughâ from flat to conforming states and emphasizes the crucial role of substrate shape in determining the nature of this transition. Our analytical results are consistent with numerical simulations using a van der Waals-like interaction . Finally we propose a novel substrate shape that should exhibit a continuous, rather than âsnap-throughâ, transition
Floating carpets and the delamination of elastic sheets
We investigate the deformation of a thin elastic sheet floating on a liquid surface and subject to a uniaxial compression. We show that at a critical compression the sheet delaminates from the liquid over a finite region forming a delamination âblisterâ. This blistering regime adds to the wrinkling and localized folding regimes that have been studied previously. The transition from wrinkled to blistered states occurs when delamination becomes energetically favourable compared to wrinkling. We determine the initial blister size and the evolution of blister size with continuing compression before verifying our theoretical results with experiments at a macroscopic scale
Impact for Agents
Impact for agents. Most of the agent research community has been predicting greater impact for years and many of us have been working to help the process along. Yet the tremendous growth on the research front has not been met with
Timelike deeply virtual Compton scattering with a linearly polarized real (or quasi-real) photon beam
We calculate timelike virtual Compton scattering amplitudes in the
generalized Bjorken scaling regime and focus on a new polarization asymmetry in
the scattering process with a linearly polarized photon beam in the medium
energy range, which will be studied intensely at JLab12 experiments. We
demonstrate that new observables help us to access the polarized quark and
gluon generalized parton distributions and .Comment: To appear in the proceedings XXII. International Workshop on Deep
Inelastic Scattering and Related Subjects (DIS 2014), 28 April - 2 May 2014,
Warsaw, Polan
Psychoanalysis and male homosexuality
This thesis explores the status of homosexuality, within the history of psychoanalysis, and the effects of that status in the development of contemporary talking therapies. Focusing on homosexuality in men, the research in this study examines Freudâs theories and concepts, as the foundation of this thesis. This paper is divided into four chapters. The first chapter is a reading of Freud and his psychogenesis of homosexuality. The second chapter is an analysis of three American analysts, who interpreted Freudâs theory of the Oedipus complex in a very particular way to make it fit for their purpose. According to these analysts homosexuality, in their view, is an illness in need of a cure. Their aim is to convert homosexuality into heterosexuality by conducting analysis on their homosexual analysands. Throughout this chapter I will be reinterpreting a case study of reparative therapy. The third chapter is a critical analysis of Richard Isayâs radical views of homosexuality. Chapter three will also introduce gay affirmative therapy; a therapy, which is aimed to help one come to terms with their homosexuality. In the fourth chapter I will critically analyse and compare a case study of reparative and gay affirmative therapy. My intentions of analysing these two case studies are to illustrate that: while they differ in their analytic approach, they share some similarities. The purpose of analysing these two therapies is that many homosexuals today undergo reparative or gay affirmative therapy. Freudâs conclusion, that homosexuality or heterosexuality is an outcome of the Oedipus complex, will play an important role in the discussion of reparative and gay affirmative therapy. His perceptions of how psychoanalysis should be conducted throughout analysis will also emphasis how far reparative and gay affirmative therapies have developed since from classical Freudian psychoanalysis
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