Large surveys of very metal-poor stars have revealed in recent years that a large fraction of these objects were carbon-rich, analogous to the more metal-rich CH-stars. The abundance peculiarities of CH-stars are commonly explained by mass-transfer from a more evolved companion. In an effort to better understand the origin and importance for Galactic evolution of Fe-poor, C-rich stars, we prese...

controlling the electromagnetic waves propagation using optical transformation is a topic that finds many applications in recent years. one of the most important applications of these transformations is hiding the objects from radar waves, i.e. cloaking. hiding under the carpet or carpet cloak is a special type of cloaking that hides the objects situated between a metal sheet and the ground. in...

Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particle...

Metal objects in the body such as hip prostheses cause artifacts in CT images. When CT images degraded by artifacts are used for treatment planning of radiotherapy, the artifacts can yield inaccurate dose calculations and, for particle beams, erroneous penetration depths. A metal artifact reduction software (O-MAR) installed on a Philips Brilliance Big Bore CT has been tested for applications i...

The present research was designed to examine how the presence or absence of ambient light influences the appearance of metal. The stimuli depicted three possible objects that were illuminated by three possible patterns of illumination. These were generated by a single point light source, two rectangular area lights, or projecting light onto a translucent white box that contained the object (and...

We consider penalized-likelihood reconstruction for X-ray computed tomography of objects that contain small metal structures. To reduce the beam hardening artefacts induced by these structures, we derive the reconstruction algorithm from a projection model that takes into account the photon emission spectrum and nonlinear variation of attenuation to photon energy. This algorithm requires excess...