21 research outputs found

    Ultrasonic benchmarking with UTdefect

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    UTDefect is a program for simulation of ultrasonic testing with emphasis on applications within the nuclear power industry. The entire testing process, including the ultrasonic transmitter, the receiver, and scattering from various types of defects of simple shape, is modelled. The basic idea behind UTDefect is to use solutions to the elastodynamic wave equation that are esentially exact. For the 2009 benchmark problems the results obtained from UTDefect are in most cases in fairly good agreement with the experimental data from CEA. © 2010 American Institute of Physics

    Ultrasonic wave propagation in an anisotropic cladding with a wavy interface

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    The propagation of ultrasonic waves in a thick plate with a cladding is investigated in the two-dimensional case. The surfaces of the plate are traction-free except where an ultrasonic probe is attached and emits waves into the plate. The plate is made of two different materials, the base material and the cladding, and these are both allowed to be anisotropic. The interface between the base material and the cladding is assumed to be wavy (sinusoidal) and this is common in practice for welded claddings. The null field approach is used to solve the wave propagation problem. Thus the starting point is the (surface) integral representations in the two materials. The Green’s tensors are chosen as the half space Green’s tensors as only the integrals along the interface then remain. The Green’s functions are expanded in Fourier transforms along the interface and the surface fields are likewise expanded. Applying the periodicity of the interface a discretized set of equations remains. For the sinusoidal interface all integrals can be computed analytically which leads to an efficient numerical scheme. Some numerical results show the influence of the anisotropy and the wavy interface

    Thoracolumbar vertebral fractures in Sweden: an analysis of 13,496 patients admitted to hospital

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    National Longitudinal data of thoracolumbar fracture incidence, trends or mortality rates are lacking. The correlation between admissions and operations of thoracolumbar vertebral fractures has not been investigated. The aim of our nationwide population-based epidemiological study was to analyse the incidence, admissions, operations, and case fatality rate among patients with thoracolumbar vertebral fractures admitted to hospital in Sweden. The Swedish Hospital Discharge Register (SHDR) and the Cause of Death Register (CDR) were linked to determine the incidence of surgical interventions, trends, characteristics of the patients, and case fatality rate for thoracolumbar vertebral fractures based on comprehensive national data. The annual incidence of thoracolumbar fractures was on average 30 per 100,000 inhabitants and did not change considerably during the study period. Among patients younger than 60 years of age the annual incidence was 13 per 100,000 and was twice as high in men compared to women. The proportion operated on was 15%. In the age-group 60 years and older the majority were women. In this group two percent were operated on. However, males were operated on twice as often as women. The 90-day case-fatality rate after surgery was 1.4%. This information may assist health care providers in health care planning. Moreover, these data can also be used for power calculations when planning future clinical studies

    Wave scattering from a rectangular crack in an anisotropic cladding

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    Wave Scattering from a Slightly Wavy Interface Between two Anisotropic Media

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    Wave scattering from a periodic interface separating two anisotropic layers in a thick elastic plate is studied in the two-dimensional case. The problem is solved by replacing the exact boundary conditions, i.e. continuous displacement and traction on the wavy interface, by approximate first order conditions on a flat reference surface. Numerical results are presented for a number of cases and compared to the exact solution obtained by the null field approach. The conclusion is that the approximate method gives reasonably accurate results as long as the slope of the surface is small and the amplitude of the wavy surface is not too large compared to the wavelength of the incident wave

    Reading times and adpative styles among patients diagnosed with psychosis as assessed by the serial color-word test

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    The present study focuses on how patients diagnosed with psychosis deal with a conflicting situation. In the study, two groups of patients were assessed. One group consisted of patients diagnosed with psychosis (n=41), while the comparison group (n=135) consisted of inpatients diagnosed either with anorexia nervosa or with bulimia nervosa. The groups were assessed using the Serial Color Word Test (S-CWT), designed for studying an individual's successive adaptation over time to a conflicting situation. The S-CWT differentiated the two groups regarding both reading time and adaptive styles. Patients diagnosed with psychosis had longer reading times and an adaptive style that was deviant throughout the test, indicating poorer cognitive functioning and more serious psychopathology. These problems may in turn influence functioning in work or study and daily living, all of which are important in treatment planning

    Antenna protein composition of PS I and PS II in thylakoid sub-domains

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    Spinach thylakoids were separated into grana core, grana margin, and two different stromal lamella fractions in the absence of detergents. The levels of all light-harvesting chlorophyll a/b-binding (LHC) proteins were determined in all fractions, and were normalised to the amount of Photosystem I (PS I) and Photosystem II (PS II) centres. PS IÎČ in the stroma lamellae was found to have a full complement of Lhca polypeptides and, probably, one attached LHC II trimer. PS Iα binds additional LHC II trimers, but PS I centres located in the inner parts of the grana stack lack Lhca1 and are depleted in Lhca4. PS IIÎČ, found in grana margins and stroma lamellae, seems to associate one monomer each of Lhcb4, Lhcb5 and Lhcb6 (CP29, CP26 and CP24, respectively) and one LHC II trimer consisting of two Lhcb1 and one Lhcb3 subunit. PS IIα has additional LHC II trimers (consisting of Lhcb1 and Lhcb2) attached. We also find evidence for the existence of both PS I and PS II centres in the extreme stroma (probably centres being synthesised or repaired), that lack all LHC proteins

    Minnesteckningar över avlidna ledamöter 2010. SĂ€rtryck ur KVVS Årsbok 2011

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    Minnesteckningar. Kungl. Vetenskaps- och Vitterhets-SamhĂ€llet - ledamöter avlidna 2010. Bengt Holmberg, Gunilla Åkerström-Hougen, Gunnar Harling, Jan S. Nilsson, Ulf Lagerkvist, Erik Frykman, Sigvard Rubenowit
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