2,671 research outputs found
A neutron scattering study of the interplay between structure and magnetism in Ba(FeCo)As
Single crystal neutron diffraction is used to investigate the magnetic and
structural phase diagram of the electron doped superconductor
Ba(FeCo)As. Heat capacity and resistivity measurements have
demonstrated that Co doping this system splits the combined antiferromagnetic
and structural transition present in BaFeAs into two distinct
transitions. For =0.025, we find that the upper transition is between the
high-temperature tetragonal and low-temperature orthorhombic structures with
( K) and the antiferromagnetic transition occurs at
K. We find that doping rapidly suppresses the
antiferromagnetism, with antiferromagnetic order disappearing at . However, there is a region of co-existence of antiferromagnetism and
superconductivity. The effect of the antiferromagnetic transition can be seen
in the temperature dependence of the structural Bragg peaks from both neutron
scattering and x-ray diffraction. We infer from this that there is strong
coupling between the antiferromagnetism and the crystal lattice
Comparison and calibration of a real-time virtual stenting algorithm using Finite Element Analysis and Genetic Algorithms
In this paper, we perform a comparative analysis between two computational methods for virtual stent deployment: a novel fast virtual stenting method, which is based on a spring–mass model, is compared with detailed finite element analysis in a sequence of in silico experiments. Given the results of the initial comparison, we present a way to optimise the fast method by calibrating a set of parameters with the help of a genetic algorithm, which utilises the outcomes of the finite element analysis as a learning reference. As a result of the calibration phase, we were able to substantially reduce the force measure discrepancy between the two methods and validate the fast stenting method by assessing the differences in the final device configurations
Ceramic production and raw materials in the Tuscan-Ligurian region: an archaeological and petrographic approach in a diachronic perspective
This contribute focuses on the history of ceramic production of a large geographic area from the
archaeological point of view encompassing Liguria and N-W Tuscany and using a petro-archaeometrical approach ( essentially based on thin-section analyses of more than a thousand of samples)
Scintillating double beta decay bolometers
We present the results obtained in the development of scintillating Double
Beta Decay bolometers. Several Mo and Cd based crystals were tested with the
bolometric technique. The scintillation light was measured through a second
independent bolometer. A 140 g CdWO_4 crystal was run in a 417 h live time
measurement. Thanks to the scintillation light, the alpha background is easily
discriminated resulting in zero counts above the 2615 keV gamma line of
Thallium 208. These results, combined with an extremely easy light detector
operation, represent the first tangible proof demonstrating the feasibility of
this kind of technique.Comment: 15 pages, 8 figure
Characterization of Flow Dynamics in the Pulmonary Bifurcation of Patients With Repaired Tetralogy of Fallot: A Computational Approach
The hemodynamic environment of the pulmonary bifurcation is of great importance for
adult patients with repaired tetralogy of Fallot (rTOF) due to possible complications in the
pulmonary valve and narrowing of the left pulmonary artery (LPA). The aim of this study
was to computationally investigate the effect of geometrical variability and flow split on
blood flow characteristics in the pulmonary trunk of patient-specific models. Data from
a cohort of seven patients was used retrospectively and the pulmonary hemodynamics
was investigated using averaged and MRI-derived patient-specific boundary conditions
on the individualized models, as well as a statistical mean geometry. Geometrical analysis
showed that curvature and tortuosity are higher in the LPA branch, compared to the right
pulmonary artery (RPA), resulting in complex flow patterns in the LPA. The computational
analysis also demonstrated high time-averaged wall shear stress (TAWSS) at the outer
wall of the LPA and the wall of the RPA proximal to the junction. Similar TAWSS patterns
were observed for averaged boundary conditions, except for a significantly modified
flow split assigned at the outlets. Overall, this study enhances our understanding about
the flow development in the pulmonary bifurcation of rTOF patients and associates
some morphological characteristics with hemodynamic parameters, highlighting the
importance of patient-specificity in the models. To confirm these findings, further studies
are required with a bigger cohort of patients
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