741 research outputs found

    Magnetization of SrCu2(BO3)2 in ultrahigh magnetic fields up to 118 T

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    The magnetization process of the orthogonal-dimer antiferromagnet SrCu2(BO3)2 is investigated in high magnetic fields of up to 118 T. A 1/2 plateau is clearly observed in the field range 84 to 108 T in addition to 1/8, 1/4 and 1/3 plateaux at lower fields. Using a combination of state-of-the-art numerical simulations, the main features of the high-field magnetization, a 1/2 plateau of width 24 T, a 1/3 plateau of width 34 T, and no 2/5 plateau, are shown to agree quantitatively with the Shastry-Sutherland model if the ratio of inter- to intra-dimer exchange interactions J'/J=0.63. It is further predicted that the intermediate phase between the 1/3 and 1/2 plateau is not uniform but consists of a 1/3 supersolid followed by a 2/5 supersolid and possibly a domain-wall phase, with a reentrance into the 1/3 supersolid above the 1/2 plateau.Comment: 5 pages + 10 pages supplemental materia

    Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS - a collection of Technical Notes Part 1

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    This report provides an introduction and overview of the Technical Topic Notes (TTNs) produced in the Towards Identifying and closing Gaps in Assurance of autonomous Road vehicleS (Tigars) project. These notes aim to support the development and evaluation of autonomous vehicles. Part 1 addresses: Assurance-overview and issues, Resilience and Safety Requirements, Open Systems Perspective and Formal Verification and Static Analysis of ML Systems. Part 2: Simulation and Dynamic Testing, Defence in Depth and Diversity, Security-Informed Safety Analysis, Standards and Guidelines

    Syntactic Control of Interference Revisited

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    In Syntactic Control of Interference (POPL, 1978), J. C. Reynolds proposes three design principles intended to constrain the scope of imperative state effects in Algol-like languages. The resulting linguistic framework seems to be a very satisfactory way of combining functional and imperative concepts, having the desirable attributes of both purely functional languages (such as pcf) and simple imperative languages (such as the language of while programs). However, Reynolds points out that the obvious syntax for interference control has the unfortunate property that fi-reductions do not always preserve typings. Reynolds has subsequently presented a solution to this problem (ICALP, 1989), but it is fairly complicated and requires intersection types in the type system. Here, we present a much simpler solution which does not require intersection types. We first describe a new type system inspired in part by linear logic and verify that reductions preserve typings. We then define a class of bireflective models, which provide a categorical analysis of structure underlying the new typing rules; a companion paper Bireflectivity, in this volume, exposes wider ramifications of this structure. Finally, we describe a concrete model for an illustrative programming language based on the new type system; this improves on earlier such efforts in that states are not assumed to be structured using locations

    Traces on the Sklyanin algebra and correlation functions of the eight-vertex model

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    We propose a conjectural formula for correlation functions of the Z-invariant (inhomogeneous) eight-vertex model. We refer to this conjecture as Ansatz. It states that correlation functions are linear combinations of products of three transcendental functions, with theta functions and derivatives as coefficients. The transcendental functions are essentially logarithmic derivatives of the partition function per site. The coefficients are given in terms of a linear functional on the Sklyanin algebra, which interpolates the usual trace on finite dimensional representations. We establish the existence of the functional and discuss the connection to the geometry of the classical limit. We also conjecture that the Ansatz satisfies the reduced qKZ equation. As a non-trivial example of the Ansatz, we present a new formula for the next-nearest neighbor correlation functions.Comment: 35 pages, 2 figures, final versio

    Percutaneous endoscopic gastrojejunostomy for a patient with an intractable small bowel injury after repeat surgeries: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The management of intestinal injury can be challenging, because of the intractable nature of the condition. Surgical treatment for patients with severe adhesions sometimes results in further intestinal injury. We report a conservative management strategy using percutaneous endoscopic gastrojejunostomy for an intractable small bowel surgical injury after repeated surgeries.</p> <p>Case presentation</p> <p>A 78-year-old Japanese woman had undergone several abdominal surgeries including urinary cystectomy for bladder cancer. After this operation, she developed peritonitis as a result of a small bowel perforation thought to be due to an injury sustained during the operation, with signs consistent with systemic inflammatory response syndrome: body temperature 38.5°C, heart rate 92 beats/minute, respiratory rate 23 breaths/minute, white blood cell count 11.7 × 10<sup>9</sup>/L (normal range 4-11 × 10<sup>9</sup>/μL). Two further surgical interventions failed to control the leak, and our patient's clinical condition and nutritional status continued to deteriorate. We then performed percutaneous endoscopic gastrojejunostomy, and continuous suction was applied as an alternative to a third surgical intervention. With this endoscopic intervention, the intestinal leak gradually closed and oral feeding became possible.</p> <p>Conclusion</p> <p>We suggest that the technique of percutaneous endoscopic gastrojejunostomy combined with a somatostatin analog is a feasible alternative to surgical treatment for small bowel leakage, and is less invasive than a nasojejunal tube.</p

    A Q-operator for the twisted XXX model

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    Taking the isotropic limit in a recent representation theoretic construction of Baxter's Q-operators for the XXZ model with quasi-periodic boundary conditions we obtain new results for the XXX model. We show that quasi-periodic boundary conditions are needed to ensure convergence of the Q-operator construction and derive a quantum Wronskian relation which implies two different sets of Bethe ansatz equations, one above the other below the "equator" of total spin zero. We discuss the limit to periodic boundary conditions at the end and explain how this construction might be useful in the context of correlation functions on the infinite lattice. We also identify a special subclass of solutions to the quantum Wronskian for chains up to a length of 10 sites and possibly higher.Comment: 19 page
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