3,191 research outputs found

    The significance of a new locality for Monograptus thomasi (Early Devonian) southwest of Beaconsfield, Tasmania, and of the Corn Hill Formation

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    Monograptus thomasi, Early Devonian, occurs west of Cabbage Tree Hill, Beaconsfield, Tasmania, in rocks previously mapped as Cambrian. The occurrence constrains the location of a basal thrust considered to be a conduit for Late Devonian gold mineralisation. The Corn Hill Formation, which contains the graptolite, is significant in regional stratigraphic, palaeogeographic, structural and tectonic models

    Optimised multi-camera systems for dimensional control in factory environments

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    As part of the United Kingdom’s Light Controlled Factory project, University College London aims to develop a large-scale multi-camera system for dimensional control tasks in manufacturing, such as part assembly and tracking. Accuracy requirements in manufacturing are demanding, and improvements in the modelling and analysis of both camera imaging and the measurement environment are essential. A major aspect to improved camera modelling is the use of monochromatic imaging of retro-reflective target points, together with a camera model designed for a particular illumination wavelength. A small-scale system for laboratory testing has been constructed using eight low-cost monochrome cameras with C-mount lenses on a rigid metal framework. Red, green and blue monochromatic light-emitting diode ring illumination has been tested, with a broadband white illumination for comparison. Potentially, accuracy may be further enhanced by the reduction in refraction errors caused by a non-homogeneous factory environment, typically manifest in varying temperatures in the workspace. A refraction modelling tool under development in the parallel European Union LUMINAR project is being used to simulate refraction in order to test methods which may be able to reduce or eliminate this effect in practice

    CuInS2/ZnS nanocrystals as sensitisers for NiO photocathodes

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    Nickel oxide (NiO) is the most universally studied photocathode to date, however, its poor fill factor (FF) makes its efficiency much lower than its counterpart, n-type photoanodes. Its significance in photovoltaics is based on the potential to fabricate tandem photoelectrodes in order to enhance the overall efficiency of the existing devices. Furthermore, limited work on the sensitisation of NiO with semiconducting nanocrystals (NCs) exists. For the first time, we have fabricated NiO photocathodes sensitised with aqueous CuInS2/ZnS NCs. The NCs were chemically bound to the NiO films with the aid of carboxyl and thiol groups. This was achieved without modifying the bulk surface properties of NiO. Binding of the NCs was investigated using TEM, SEM, XPS, XANES, EXAFS modelling and ToF-SIMS. NiO films were assembled into CuInS2/ZnS NC sensitised photocathodes and their photovoltaic properties were compared to those of unsensitised and dye-sensitised NiO solar cells. We demonstrate that nontoxic NCs can be used to sensitise NiO photocathodes to achieve an (almost) all-inorganic system

    Minimal Model Holography for SO(2N)

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    A duality between the large N 't Hooft limit of the WD_N minimal model CFTs and a higher spin gravity theory on AdS3 is proposed. The gravity theory has massless spin fields of all even spins s=2,4,6,..., as well as two real scalar fields whose mass is determined by the 't Hooft parameter of the CFT. We show that, to leading order in the large N limit, the 1-loop partition function of the higher spin theory matches precisely with the CFT partition function.Comment: 21 pages, LaTe

    Twice Bitten, Thrice Shy: A Case of Recurrent Isolated Cardiac Sarcoidosis in the Transplanted Heart.

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    We present a case of recurrent isolated cardiac sarcoidosis, 3 years post-heart transplantation. The case highlights the scarcity of data on the utility of immunosuppression in cardiac sarcoidosis and, in particular, raises questions about the optimal immunosuppression regimen in transplant recipients. (Level of Difficulty: Advanced.)

    Higher spin AdS_3 holography with extended supersymmetry

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    We propose a holographic duality between a higher spin AdS_3 gravity with so(p) extended supersymmetry and a large N limit of a 2-dimensional Grassmannian-like model with a specific critical level k=N and a non-diagonal modular invariant. As evidence, we show the match of one-loop partition functions. Moreover, we construct symmetry generators of the coset model for low spins which are dual to gauge fields in the supergravity. Further, we discuss a possible relation to superstring theory by noticing an N=3 supersymmetry of critical level model at finite k,N. In particular, we examine BPS states and marginal deformations. Inspired by the supergravity side, we also propose and test another large N CFT dual obtained as a Z_2 automorphism truncation of a similar coset model, but at a non-critical level.Comment: 44 pages, published versio

    Computational modelling of emboli travel trajectories in cerebral arteries: Influence of microembolic particle size and density

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    This article has been made available through the Brunel Open Access Publishing Fund.Ischaemic stroke is responsible for up to 80 % of stroke cases. Prevention of the reoccurrence of ischaemic attack or stroke for patients who survived the first symptoms is the major treatment target. Accurate diagnosis of the emboli source for a specific infarction lesion is very important for a better treatment for the patient. However, due to the complex blood flow patterns in the cerebral arterial network, little is known so far of the embolic particle flow trajectory and its behaviour in such a complex flow field. The present study aims to study the trajectories of embolic particles released from carotid arteries and basilar artery in a cerebral arterial network and the influence of particle size, mass and release location to the particle distributions, by computational modelling. The cerebral arterial network model, which includes major arteries in the circle of Willis and several generations of branches from them, was generated from MRI images. Particles with diameters of 200, 500 and 800 μ m and densities of 800, 1,030 and 1,300 kg/m 3 were released in the vessel's central and near-wall regions. A fully coupled scheme of particle and blood flow in a computational fluid dynamics software ANASYS CFX 13 was used in the simulations. The results show that heavy particles (density large than blood or a diameter larger than 500 μ m) normally have small travel speeds in arteries; larger or lighter embolic particles are more likely to travel to large branches in cerebral arteries. In certain cases, all large particles go to the middle cerebral arteries; large particles with higher travel speeds in large arteries are likely to travel at more complex and tortuous trajectories; emboli raised from the basilar artery will only exit the model from branches of basilar artery and posterior cerebral arteries. A modified Circle of Willis configuration can have significant influence on particle distributions. The local branch patterns of internal carotid artery to middle cerebral artery and anterior communicating artery can have large impact on such distributions. © 2014 The Author(s)

    Mapping The Toronto Theatre Blogosphere

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    From online reviews, to live tweeting during a performance, to “liking” a production on Facebook, the blogosphere is transforming how we talk about theatre. Theatre criticism in the digital world is now a “team sport,” where audience members and artists play alongside professional critics (Fricker 49). This shift holds much potential: online critical discourse can help us develop a more diverse and inclusive picture of theatre reception and theatre-going cultures than print reviews, and expand the historical documentation of performance, which, as a vanishing art form, leaves very few traces of itself. However, the limited research in this area has yet to fully understand the role of the blogosphere in theatre ecology or how to archive the criticism found there (Collins ; Poll ; Radosavljevic). “Mapping the Toronto Theatre Blogosphere” is a new research project bringing together Dramatic Art and Computer Science students. It attempts to answer two key questions: how is the blogosphere changing how we talk about theatre, and how can we preserve the critical discourse occurring there? To answer the first question, we tracked and archived the online critical response (blog reviews, online publications, tweets, and Facebook posts) to a representative sample from the fall 2016 Toronto theatre season. Our resulting dataset was examined using a content analysis approach in order to identify which productions generated the most critical response (posts) online, the demographics of the posters (including age, gender, occupation, and ethnicity), and the purpose of the posts (including commentary on the production, socio-political commentary, endorsements, and check-ins). To answer the second question, our CS team member is developing an open-access website to archive the materials collected, which the public will be invited to use and contribute to once it is launched. Our preliminary findings suggest that the blogosphere is changing how we talk about theatre in three key ways: it is providing more coverage to new plays and plays about political or controversial subject matter; it is increasing and diversifying the participants in critical discourse, allowing women and people of colour more access into the conversations; and it is connecting discussions about theatre to other topics such as political issues and identity. Our UWill Discover presentation will summarize our findings about the Toronto theatre blogosphere and include an interactive demonstration of our database
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