53 research outputs found

    Solitary and compact-like shear waves in the bulk of solids

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    We show that a model proposed by Rubin, Rosenau, and Gottlieb [J. Appl. Phys. 77 (1995) 4054], for dispersion caused by an inherent material characteristic length, belongs to the class of simple materials. Therefore, it is possible to generalize the idea of Rubin, Rosenau, and Gottlieb to include a wide range of material models, from nonlinear elasticity to turbulence. Using this insight, we are able to fine-tune nonlinear and dispersive effects in the theory of nonlinear elasticity in order to generate pulse solitary waves and also bulk travelling waves with compact support

    Modular symbols in Iwasawa theory

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    This survey paper is focused on a connection between the geometry of GLd\mathrm{GL}_d and the arithmetic of GLd1\mathrm{GL}_{d-1} over global fields, for integers d2d \ge 2. For d=2d = 2 over Q\mathbb{Q}, there is an explicit conjecture of the third author relating the geometry of modular curves and the arithmetic of cyclotomic fields, and it is proven in many instances by the work of the first two authors. The paper is divided into three parts: in the first, we explain the conjecture of the third author and the main result of the first two authors on it. In the second, we explain an analogous conjecture and result for d=2d = 2 over Fq(t)\mathbb{F}_q(t). In the third, we pose questions for general dd over the rationals, imaginary quadratic fields, and global function fields.Comment: 43 page

    Global generalized solutions for Maxwell-alpha and Euler-alpha equations

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    We study initial-boundary value problems for the Lagrangian averaged alpha models for the equations of motion for the corotational Maxwell and inviscid fluids in 2D and 3D. We show existence of (global in time) dissipative solutions to these problems. We also discuss the idea of dissipative solution in an abstract Hilbert space framework.Comment: 27 pages, to appear in Nonlinearit

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Session 17 Ecophysiology

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    Calcium phosphates grown on bacterial cellulose template

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    © 2018 Elsevier Ltd and Techna Group S.r.l. Bacterial cellulose membranes were employed as templates for calcium phosphates deposition by successive immersion in solutions of Ca(NO 3 ) 2 ·4H 2 O and (NH 4 ) 2 HPO 4 , under ultrasonication. During the wet chemical reaction, mineral phases were loaded on bacterial cellulose fibrils, leading to precursor hybrid composites. These were subjected to a lyophilisation procedure in order to preserve the 3D porous aspect and afterwards to a thermal treatment with the aim of removing the polymeric phase and generating well crystallized structures. Different types of morphologies were achieved by varying the heating rate, as well as the calcination temperature and period. The as-prepared samples and the final ones were investigated from compositional and structural point of view through X-ray diffraction and Fourier-transform infrared spectroscopy and morphologically concerning by scanning electron microscopy. The magnetic properties were also evaluated in order to demonstrate the suitability of the obtained materials for the development of magnetic scaffolds dedicated to hard tissue applications

    Interagency Relations and the {EU} Migration Crisis: Strengthening of Law Enforcement Through Agencification?

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    While scholarly literature on Frontex has mushroomed over the last decade, agency’s interaction with other EU Justice and Home Affairs (JHA) agencies has received less attention. It is the objective of this paper to analyse how the crisis has shaped the horizontal interactions between EU JHA agencies and ask whether these relations have either enhanced the law enforcement focus of EU JHA or, conversely, strengthened a human rights-promoting EU as a ‘Union of Values’. Empirically, the chapter assesses the relations of Frontex with other JHA-related agencies such as the European Asylum Support Office or the Fundamental Rights Agency before and after the 2015 migration crisis. We argue that despite an increased human rights sensitivity, the migration crisis has not substantially changed the border management approach of Frontex but rather consolidated law enforcement profile of interagency cooperation and led only to minor improvements of fundamental rights
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