1,455 research outputs found
Geometric observation for the Bures fidelity between two states of a qubit
In this Brief Report, we present a geometric observation for the Bures
fidelity between two states of a qubit.Comment: 4 pages, 1 figure, RevTex, Accepted by Phys. Rev.
Experimental study exploring the factors that promote rib fragility in the elderly
Rib fractures represent a common injury type due to blunt chest trauma, affecting hospital stay and mortality especially in elderly patients. Factors promoting rib fragility, however, are little investigated. The purpose of this in vitro study was to explore potential determinants of human rib fragility in the elderly. 89 ribs from 13 human donors (55\u201399 years) were loaded in antero-posterior compression until fracture using a material testing machine, while surface strains were captured using a digital image correlation system. The effects of age, sex, bone mineral density, rib level and side, four global morphological factors (e.g. rib length), and seven rib cross-sectional morphological factors (e.g. cortical thickness, determined by \u3bcCT), on fracture load were statistically examined using Pearson correlation coefficients, Mann\u2013Whitney U test as well as Kruskal\u2013Wallis test with Dunn-Bonferroni post hoc correction. Fracture load showed significant dependencies (p < 0.05) from bone mineral density, age, antero-posterior rib length, cortical thickness, bone volume/tissue volume ratio, trabecular number, trabecular separation, and both cross-sectional area moments of inertia and was significantly higher at rib levels 7 and 8 compared to level 4 (p = 0.001/0.013), whereas side had no significant effect (p = 0.989). Cortical thickness exhibited the highest correlation with fracture load (r = 0.722), followed by the high correlation of fracture load with the area moment of inertia around the longitudinal rib cross-sectional axis (r = 0.687). High correlations with maximum external rib surface strain were detected for bone volume/tissue volume ratio (r = 0.631) and trabecular number (r = 0.648), which both also showed high correlations with the minimum internal rib surface strain (r = 12 0.644/ 12 0.559). Together with rib level, the determinants cortical thickness, area moment of inertia around the longitudinal rib cross-sectional axis, as well as bone mineral density exhibited the largest effects on human rib fragility with regard to the fracture load. Sex, rib cage side, and global morphology, in contrast, did not affect rib fragility in this study. When checking elderly patients for rib fractures due to blunt chest trauma, patients with low bone mineral density and the mid-thoracic area should be carefully examined
Kneadings, Symbolic Dynamics and Painting Lorenz Chaos. A Tutorial
A new computational technique based on the symbolic description utilizing
kneading invariants is proposed and verified for explorations of dynamical and
parametric chaos in a few exemplary systems with the Lorenz attractor. The
technique allows for uncovering the stunning complexity and universality of
bi-parametric structures and detect their organizing centers - codimension-two
T-points and separating saddles in the kneading-based scans of the iconic
Lorenz equation from hydrodynamics, a normal model from mathematics, and a
laser model from nonlinear optics.Comment: Journal of Bifurcations and Chaos, 201
Electron g-Factor Anisotropy in Symmetric (110)-oriented GaAs Quantum Wells
We demonstrate by spin quantum beat spectroscopy that in undoped symmetric
(110)-oriented GaAs/AlGaAs single quantum wells even a symmetric spatial
envelope wavefunction gives rise to an asymmetric in-plane electron
Land\'e-g-factor. The anisotropy is neither a direct consequence of the
asymmetric in-plane Dresselhaus splitting nor of the asymmetric Zeeman
splitting of the hole bands but is a pure higher order effect that exists as
well for diamond type lattices. The measurements for various well widths are
very well described within 14 x 14 band k.p theory and illustrate that the
electron spin is an excellent meter variable to map out the internal -otherwise
hidden- symmetries in two dimensional systems. Fourth order perturbation theory
yields an analytical expression for the strength of the g-factor anisotropy,
providing a qualitative understanding of the observed effects
Fatigue analysis-based numerical design of stamping tools made of cast iron
This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the SâN curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (SâN) curves for this material is determined at room temperature under push pull loading with different load ratios R0Ïmin/Ïmax0â2, R0â1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important
Lurbinectedin in Refractory Diffuse Malignant Peritoneal Mesothelioma: Report of Two Cases.
Mesothelioma is a malignancy of serosal membranes. Parietal pleura is the most common site, with peritoneum being the second most frequent location. Malignant peritoneal mesothelioma (MPM) is a rare and aggressive disease. The prognosis is often very poor with median overall survival ranging from 6 to 18 months in patients who are not candidates for cytoreductive surgery (CRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) due to non-resectable disease or comorbid conditions. For patients with resectable disease, CRS and HIPEC have become the standard of care. However, for patients with unresectable malignant mesothelioma there is unfortunately no effective systemic treatment beyond the first line. Based on the results of a recent phase II trial, lurbinectedin has clinical activity and acceptable toxicity in the second- and third-line treatment of malignant pleural mesothelioma. However, until present, no data have been available for patients with MPM and for patients who become refractory after multiple treatment lines. We report on two patients with metastatic MPM who achieved durable disease control of 10+ and 8 months with lurbinectedin in the fourth and fifth treatment line, respectively
Principals of the theory of light reflection and absorption by low-dimensional semiconductor objects in quantizing magnetic fields at monochromatic and pulse excitations
The bases of the theory of light reflection and absorption by low-dimensional
semiconductor objects (quantum wells, wires and dots) at both monochromatic and
pulse irradiations and at any form of light pulses are developed. The
semiconductor object may be placed in a stationary quantizing magnetic field.
As an example the case of normal light incidence on a quantum well surface is
considered. The width of the quantum well may be comparable to the light wave
length and number of energy levels of electronic excitations is arbitrary. For
Fourier-components of electric fields the integral equation (similar to the
Dyson-equation) and solutions of this equation for some individual cases are
obtained.Comment: 14 page
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