An inverse analyses procedure for determining the mechanical material properties of strain hardening cement-based materials is presented. It allows to determine the uniaxial stressstrain curve up to the material’s localization point on the basis of the results of four-point bending tests. In these tests, the beam curvature is measured and serves as input value for the inverse analysis. An evolu...

Generation of “Laser Light Sheet” beams and linear laser spots characterized by uniform irradiance distribution is important in various laser techniques like Particle Image Velocimetry (PIV), Laser-Induced Fluorescence (LIF), hardening, annealing, cladding, uniform laser illumination of linear spatial light modulators. This task can be successfully solved with using refractive beam shaping opti...

A Monte Carlo model has been developed using the MCNP code to aid the design of a flattening filter, to improve field uniformity of a superficial x-ray machine. The machine is operating at 90 kV and filtered with a 1.1 mm aluminium filter. In the theoretical simulation the original flat filter was replaced by a varying thickness filter to improve the uniformity across field sizes 20, 5 and 2 cm...

CT findings of the base of the neck are often degraded by beam-hardening artifact from the shoulder girdle. This artifact can be reduced by placing the patient in a "swimmer's" position, a supine position in which the patient has one arm fully abducted and the other arm lowered. We selectively employed swimmer's CT in patients between January 1999 and December 2002 when standard (arms-down) CT ...

Coronary calcium causes beam hardening and blooming artifacts on cardiac computed tomography angiography (CTA) images, which lead to overestimation of lumen stenosis and reduction of diagnostic specificity. To properly remove coronary calcification and restore arterial lumen precisely, we propose a machine learning-based method with a multi-step inpainting process. We developed a new network co...

We have developed an industrial CT and Digital Radiography system (CT/DR) for NDT at the USC (Spain). A 510 mm long detector array of 640 detection elements with sub-millimetre spacing (0.8 mm), together with a 50kV mini-focus tube have been integrated in a 3-axis positioning system of flexible configuration. Accurate characterization of geometrical parameters and system commissioning has been ...

We consider a model for one-dimensional transversal oscillations of an elastic-ideally plastic beam. It is based on the von Mises model of plasticity and leads after a dimensional reduction to a fourth-order partial differential equation with a hysteresis operator of Prandtl-Ishlinskii type whose weight function is given explicitly. In this paper, we study the case of clamped beams involving a ...

Since the advent of CT, imaging of the posterior fossa has posed problems. The proximity and density of the temporal bones have created artifacts at the interfaces with brain [1]. Nevertheless, thinner sections through the posterior fossa reduce the partial volume artifacts [2], and the use of a method we call the composite addition technique (CAT) together with higher tube voltage further redu...