摘要:
In the present invention, an iterative process is provided for computed tomographic fluoroscopy (CTF) based upon an ordered-subset based algorithm or an adaptation of the row-action expectation maximization (RAEM) formula. This process is applied to reduce metal artifacts in CTF imaging, reduce image noise and provide rapid-image updating suitable for real-time applications. In one embodiment, generation of a projection mask and computation of a relaxation matrix are used to compensate for beam divergence and data incompleteness, and a priori knowledge such as a known image support is used to reduce image reconstruction errors.
摘要:
A method for the simultaneous deposition of chromium and silicon to form a diffusion coating on a workpiece uses a halide-activated cementation pack with a dual halide activator. Elemental metal powders may be employed with the dual activator. A two-step heating schedule prevents blocking a chromium carbide from forming at the surface of the workpiece. Small contents of either Ce or V can be added to the Cr+Si contents of the coating by introducing oxides of Ce or V into the filler of the pack.