background: providing a cross-sectional image is essential for preimplant assessments. computed tomography (ct) and cone beam ct (cbct) images are very expensive and provide high radiation dose. tangential projection is a very simple, available, and low-dose technique that can be used in the anterior portion of mandible. the purpose of this study was to evaluate the accuracy of tangential proje...

In this paper we extend three results about polycycles (also known as graphs) of planar smooth vector field to non-smooth fields piecewise fields, or Filippov systems). The considered here may contain hyperbolic saddles, semi-hyperbolic saddle-nodes and tangential singularities any degree. We determine when the polycycle is stable unstable. prove bifurcation at most one limit cycle in some cond...

Skin dose assessment for chest wall radiotherapy is important to ensure sufficient dose to the surface target volume without excessive skin reaction. This study quantified changes to the surface doses as a function of bolus material for conventional and intensity modulated radiation therapy (IMRT) tangential fields. Three types of bolus materials (2 mm solid, 2 mm fine mesh and 3.2 mm large mes...

When one wants to treat the time-harmonic Maxwell equations with variational methods, one has to face the problem that the natural bilinear form is not coercive on the whole Sobolev space H. On can, however, make it coercive by adding a certain bilinear form on the boundary of the domain. This addition causes a change in the natural boundary conditions. The additional bilinear form (see (2.7), ...

During breast radiotherapy treatment, the contralateral breast receives radiation doses to the skin and subcutaneous tissue caused mainly from incident electron contamination and low energy photon scatter radiation. Measurements have shown that for a typical hybrid tangential treatment, these dose levels can be up to 17% of maximum applied prescription dose if no shielding is used during the tr...

In this paper a hybrid FEMMOM method was used to solve a canonical printed circuit board (PCB) problem. The PCB is populated with three traces. One is a signal line and the other two are I/O lines that extend beyond the boundary of the board. The Finite Element Method (FEM) was used to model the fields in the volume around the on-board trace. The Method of Moments (MOM) was employed to model th...

Recent work has shown that salient perceptual singularities occur in visual textures even in the absence of feature gradients. In smoothly varying orientation-defined textures, these striking non-smooth percepts can be predicted from two texture curvatures, one tangential and one normal [Proc. Natl. Acad. Sci. USA103, 15704 (2006)]. We address the issue of detecting these perceptual singulariti...

OBJECTIVE While standard magnetoencephalographic systems record only one component of the biomagnetic field, novel vector-biomagnetometers enable measurement of all three components of the field at each sensing point. Because information content in standard one-component magnetoencephalography (MEG) is often not adequate to reconstruct quasi-radial dipolar activity, we tested the hypothesis tha...

the existing studies of threshing process of combine harvesters adopt the assumption of constant mass, which is contradictory to the phenomenon of separation of grains and short stalks in actual threshing process. therefore, the characteristics of threshing and separation are not accurately described. aiming at this problem, this study established the tangential-longitudinal threshing and separ...

Using a MEMS-based sensing device, we have measured the normal and tangential stress fields at the base of a rough elastomer layer in contact with a smooth glass cylinder in steady sliding. This geometry allows for a direct comparison between the stress profiles measured along the sliding direction and the predictions of an original exact bidimensional model of friction. The latter assumes Amon...