OBJECTIVES The aim of this study was to assess the effect of tube current, kilovoltage peak (kVp), metal type, and the position of metal objects on metal artifacts in cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS Titanium and cobalt-chromium rods were fabricated and placed in a dry human mandible. Samples were scanned using a Promax 3D CBCT unit with different milli-amper...

From the early Copper Age several millennia ago, to the beginning of the Steel Age in the 19th century, our capacity to access and manipulate metals has created the foundation for the modern world. Today, metal structures are ubiquitous— from the tallest skyscrapers to the most elegant of jewelry—that we often forget much of it originated from metal containing ores, comprised of metal compounds...

All metal objects support fluctuating currents that are responsible for evanescent-wave Johnson noise in their vicinity due to both thermal and quantum effects. The fields can decohere qubits. It is quantified by the average value of $\mathbf{B}(\mathbit{x},t)\phantom{\rule{0.28em}{0ex}}\mathbf{B}({\mathbit{x}}^{\ensuremath{'}},{t}^{\ensuremath{'}})$ its time Fourier transform. We develop forma...

This paper describes a method of automated type and pose (position and orientation) identification of partially exposed metal objects that makes excavation of hazardous materials safe and efficient. The object pose is estimated by matching a model of the object to the area that is extracted from the range image using the characteristics of metal objects. Experimental results show feasibility of...

The assessment of the detection performance of metal detectors (hand-worn, hand-held, and walk-through models) is based on the ability of the detectors to sound an alarm when presented with a test object. These test objects are typically actual threat items or simulated threat items. The orientation of these test objects with the magnetic field generated by the metal detectors may affect the de...

We present a small data base of homogeneously derived photospheric element abundances of DZ white dwarfs and related objects. Our previous investigations are supplemented with the analysis of ultraviolet spectra for nine white dwarfs. Of particular interest is the detection of Lα absorption in van Maanen 2 and a determination of the effective temperature of this star. The new value is about 100...