recent developments in nanostructured products draw considerable attention to ultrafine grained materials. these materials are normally manufactured by different severe plastic deformation (spd) methods. in the present study, analytical models and finite element method (fem) are used to calculate strain imposed to a specimen that was deformed by equal channel angular pressing (ecap). in additio...

background: in treating patients with radiation, the degree of accuracy for the delivery of tumor dose is recommended to be within ± 5% by icru in report 24. the experimental studies have shown that the presence of low-density inhomogeneity in areas such as the lung can lead to a greater than 30% change in the water dose data. therefore, inhomogeneity corrections should be used in treatment pla...

The effect of geometrical parameters involved in vortex extrusion (VE) die design, on AA1050 aluminium alloy processed by VE were investigated using finite element analysis (FEA) and response surface methodology (RSM). For this, VE die length (L), reduction in area (RA), twist angle , and position of control points in Beziers' formulation (C1) were considered as input parameters and strain inho...

Intensity inhomogeneity is a smooth intensity change inside originally homogeneous regions. The intensity inhomogeneity degrades performance of image processing algorithms. Intensity inhomogeneity correction methods are important image processing algorithms which are used to reduce the inhomogeneity. Brain image intensity inhomogeneity correction is one of the most important parts of clinical d...

This paper presents a patch-based non-parametric approach to the correction of intensity inhomogeneity from magnetic resonance (MR) images of the human brain. During image acquisition, the inhomogeneity present in the radio-frequency coil, is usually manifested on the reconstructed MR image as a smooth shading effect. This artifact can significantly deteriorate the performance of any kind of im...

In magnetic resonance imaging (MRI), image intensity inhomogeneity hampers the quantitative analysis, e.g. segmentation or registration. Intensity inhomogeneity is an effect perceived as a smooth variation in intensities across the image. This study provides an efficient, fully automated intensity inhomogeneity correction method that makes no a priori assumptions on the image intensity distribu...

introduction polymer gel dosimeters offer a practical solution to 3d dose verification for conventional radiotherapy as well as intensity-modulated and stereotactic radiotherapy. in this study, egsnrc calculated and pagat polymer gel dosimeter measured dose profiles from single shot irradiation with 18 mm collimator of gamma knife in homogeneous and inhomogeneous phantoms were compared with eac...

the microstructure of dual phase steels can be considered as a matrix of ferrite phase reinforced by martensite particles. recent measurements show that the mechanical properties of the ferrite phase are changed with the distance from the martensite grains. in this paper, a new method has been proposed to consider this phenomenon in finite element modeling of dual phase steels microstructure. i...