background cone beam computed tomography (ct) has recently become effective for oral and maxillofacial imaging. objectives the aim of this study was to assess the knowledge of dentists regarding cone beam computed tomography. materials and methods in this descriptive cross sectional study, a questionnaire regarding cone-beam computed tomography (cbct) was distributed amongst 100 dentists (gener...

In this paper, Eringen’s nonlocal elasticity and Timoshenko beam theories are implemented to analyze the bending vibration for non-uniform nano-beams.  The governing equations and the boundary conditions are derived using Hamilton’s principle. A Generalized Differential Quadrature Method (GDQM) is utilized for solving the governing equations of non-uniform Timoshenko nano-beam for pinned-pinned...

this paper describes experimental and numerical investigations on two specimens of frames composed of steel reinforced concrete beam and angle-steel concrete column under horizontal low cyclic loading. based on the test results, the relationship curves of the horizontal load-displacement and the failure modes are acquired. meanwhile the hysteretic behaviors, skeleton curves, stiffness degradati...

Tomographic imaging is a technique for exploration of a cross-section of an inspected object without destruction. Normally, the input data, known as the projections, are gathered by repeatedly radiating coherent waveform through the object in a number of viewpoints, and receiving by an array of corresponding detector in the opposite position. In this research, as a replacement of radiographs, t...

Results are presented of the first experiments with a 10 keV, 100 mA beam in the matching section for UMER. The section, about 1.5 m long, consists of one short solenoid, six printed-circuit (PC) quadrupoles, a bend PC dipole, a number of steering dipoles, and two sets of Helmholtz coils for balancing the Earth’s field. The 2 RMS beam radius as a function of axial distance in the straight part ...

A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy discriminating photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. With a mechanical rotation of a dynamic bowtie and an adaptive adjustment of an...

A particle beam of very small cross-section is useful in many accelerator applications including biological and medical ones. We show the capability of channeling technique using a micron-sized structure on a surface of a single crystal, or using a nanotube, to produce beam of a cross-section down to 1 square micrometer (or nanometer). The channeled beam can be deflected and well separated in a...

In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of xed cross-section. The radiation source can only be moved along simple standardized paths. A new radiosurgical system based on a six degree-of-freedom robotic arm has been developed to overcome limitations of conventional systems. We addr...

In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of fixed cross section. The radiation source can be moved only along simple, standardized paths. A new radiosurgical system based on a six-degree-of-freedom robotic arm has been developed to overcome limitations of conventional systems. We a...