Short-range structure and cation bonding in calcium-aluminum metaphosphate glasses.

Comprehension of short- and medium-range order of phosphate glasses is a topic of interest, due to the close relation between network structure and mechanical, thermal, and optical properties. In this work, the short-range structure of glasses (1 - x)Ca(PO(3))(2).xAl(PO(3))(3) with 0 < or = x < or = 0.

Asymmetrical gradient coil for head imaging.

This work presents a novel approach to develop dedicated transverse gradient coils for head imaging. The proposed coil design is based on the stochastic optimization of an asymmetrical stream function and improves the matching between the region-of-interest and the homogeneous gradient volume. Additionally, the electric field produced by these asymmetrical coils is 30% lower than that produced by standard symmetrical designs, which minimizes the risk of magnetostimulation of nerves in fast imaging techniques.

Fast optimization of a biplanar gradient coil set.

This work presents an approach for fast optimization of gradient coils, using the simulated annealing method. The shielding condition derived from a target field method and the analytical evaluation of the fields produced by simple geometries were used to reduce the computing time. This method is applied to the optimization of a shielded biplanar gradient coil set.

Shielded biplanar gradient coil design.

An application of the target field method to the design of shielded biplanar gradient coils for magnetic resonance imaging electromagnets is presented. Some specific cases are studied, and optimized geometries are proposed for the axial and transverse gradient coils that eliminate the third- and minimize the fifth-order terms in the magnetic field expansion.

Magnetic fields mapping with the phase reference method.

A simple method for imaging the magnetic field produced by arbitrary current distributions is presented. The method is based on the use of a phase reference image and can be easily adapted to any standard magnetic resonance imaging scanner. Examples are given to application to gradient coil characterization and quantitative field measurements.