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Page K.,Los Alamos National Laboratory | White C.E.,Los Alamos National Laboratory | White C.E.,University of Melbourne | Estell E.G.,Los Alamos National Laboratory | And 4 more authors.
Journal of Applied Crystallography | Year: 2011

Nuclear incoherent neutron scattering contributions present a challenge in the structural characterization of many classes of materials. This article introduces methods for the correction of nanoparticle, bulk crystalline and amorphous powder neutron scattering data with significant incoherent contributions from hydrogen, and describes the effects the corrections have on the resulting atomic pair distribution function data sets. The approach is presented in the context of the PDFgetN data-reduction program [Peterson, Gutmann, Proffen & Billinge (2000). J. Appl. Cryst. 33, 1192]. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.

Page K.,Los Alamos National Laboratory | Hood T.C.,Los Alamos National Laboratory | Proffen T.,Los Alamos National Laboratory | Neder R.B.,University Erlangen Nu rnberg
Journal of Applied Crystallography | Year: 2011

High-energy X-ray and spallation neutron total scattering data provide information about each pair of atoms in a nanoparticle sample, allowing for quantitative whole-particle structural modeling based on pair distribution function analysis. The realization of this capability has been hindered by a lack of versatile tools for describing complex finite structures. Here, the implementation of whole-particle refinement for complete nanoparticle systems is described within two programs, DISCUS and DIFFEV, and the diverse capabilities they present are demonstrated. The build-up of internal atomic structure (including defects, chemical ordering and other types of disorder), and nanoparticle size, shape and architecture (including core-shell structures, surface relaxation and ligand capping), are demonstrated using the program DISCUS. The structure refinement of a complete nanoparticle system (4 nm Au particles with organic capping ligands at the surface), based on neutron pair distribution function data, is demonstrated using DIFFEV, a program using a differential evolutionary algorithm to generate parameter values. These methods are a valuable addition to other probes appropriate for nanomaterials, adaptable to a diverse and complex set of materials systems, and extendable to additional data-set types. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.

Ba nsch E.,University Erlangen Nu rnberg
Computer Methods in Applied Mechanics and Engineering | Year: 2014

We consider the popular pressure correction scheme for the solution of the time dependent Navier-Stokes equations with traction boundary condition. A finite element based method to improve the performance of the classical approach is proposed. The improvement is achieved by modifying the traction boundary condition for the provisional velocity u&tild;n+1 in each time step. The corresponding term consists of a simple boundary functional involving the normal derivative of the pressure correction that can be evaluated in a natural and easy way in the context of finite elements.Computational results show a significant improvement of the solution, in particular for the pressure in the case of smooth domains. © 2014 Elsevier B.V.

MuensterM T.,University Erlangen Nu rnberg | Forst J.,Epartment of Orthopaedics | Huber H.,University Erlangen Nu rnberg
European Journal of Anaesthesiology | Year: 2012

Context Patients with Duchenne muscular dystrophy are at increased risk of some anaesthesia-related hazards such as rhabdomyolysis, fever and hyperkalaemia. Objectives To evaluate the management of anaesthesia in patients with Duchenne muscular dystrophy, including preoperative evaluation, intraoperative performance, critical events and postoperative care. Design We performed a retrospective case review study of anaesthesia in patients with Duchenne muscular dystrophy covering the period between April 2000 and December 2008. Patients 91 Duchenne patients undergoing 232 general anaesthetics for orthopaedic surgical interventions. Setting University hospital. Results Anaesthesia was performed using propofol, opioids and, if required, a non-depolarising muscle relaxant. Eight difficult direct laryngoscopies were reported. All patients undergoing spinal fusion surgery received transfusion of homologous blood products and required postoperative invasive ventilatory support for an average of 19 h. There was no severe anaesthesia-related complication and no case of unexplained fever or rhabdomyolysis. Conclusion This retrospective survey confirms clinical experience that total intravenous anaesthesia can be used safely in Duchenne patients without major concern. Further prospective studies are necessary to establish evidence-based clinical guidelines for daily practice. Copyright © 2012 European Society of Anaesthesiology.

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