The diagnostic performance of helical computed tomography (CT) is excellent. However, some artifacts have been reported, such as motion, beam hardening and scatter artifacts. We herein report a case of motion-induced artifact mimicking cervical dens fracture. A 60-year-old man was involved in a motorcycle accident that resulted in cervical spinal cord injury and quadri plegia. Reconstructed CT ...

Industrial applications require parts of components with specific surface properties such are good corrosion resistance, wear resistance and hardness. Alloys with those properties are usually very expensive and there is a great interest in reducing the cost of components for fulfilling these requirements. In this sense, laser surface processing has been used as a cost-effective technique to imp...

Background: This study aims to investigate radiation beam geometry of Cyberknife beam and change in dosimetric characteristics of six megavoltage (6MV) flattening filter free (FFF) beam after passing through high density cadmium free compensator alloy.Material and Methods: In this experimental study, changes in FFF beam dosimetric characteristics after passing through compensator alloy wa...

We show how to achieve large-amplitude oscillation and good frequency stability in a nonlinear NEMS oscillator by using a softening nonlinearity to locally balance the hardening behaviour of the Duffing nonlinearity for a given motion amplitude. The case when the softening behaviour is obtained via electrostatic biasing is theoretically investigated, under parallel-plate assumptions, for a full...

High resolution X-ray radiography and computed tomography are excellent techniques for non-destructive characterization of an object under investigation at a spatial resolution in the micrometer range. However, as the image contrast depends on both chemical composition and material density, no chemical information is obtained from this data. Furthermore, lab-based measurements are affected by t...

The high power multimode fiber-coupled laser sources, like solid state lasers or laser diodes as well as single mode and multimode fiber lasers, are now widely used in various industrial laser material processing technologies like metal or plastics welding, cladding, hardening, brazing, annealing. Performance of these technologies can be essentially improved by varying the irradiance profile of...

Punching experiments on wide honeycomb sandwich beams were performed to evaluate the predictive capabilities of a newly developed constitutive model in structural applications. The employed constitutive model for plastically com-pressible orthotropic materials accounts for both non-uniform hardening and softening associated with stressing in different directions. This feature is vital when asse...

A laser-driven electron-storage ring can produce nearly monochromatic, tunable X-rays in the keV energy regime by inverse Compton scattering. The small footprint, relative low cost and excellent beam quality provide the prospect for valuable preclinical use in radiography and tomography. The monochromaticity of the beam prevents beam hardening effects that are a serious problem in quantitative ...

In this paper, we use Hermite cubic finite elements to approximate the solutions of a nonlinear Euler– Bernoulli beam equation. The equation is derived from Hollomon’s generalized Hooke’s law for work hardening materials with the assumptions of the Euler–Bernoulli beam theory. The Ritz–Galerkin finite element procedure is used to form a finite dimensional nonlinear program problem, and a nonlin...