Abstract: Disclosed herein are systems and methods for treating a magnesium or a magnesium alloy substrate. The system includes a cleaning composition having a pH greater than 8.5 or a solvent, and a pretreatment composition comprising an organophosphate compound and/or an organophosphonate compound. The method includes contacting a substrate surface with the cleaning composition or the solvent, and contacting the surface with the pretreatment composition. Also disclosed are substrates treated with one of the systems or methods. Also disclosed are magnesium or magnesium alloy substrates wherein, between the air/substrate interface and 500 nm below the air/substrate interface (a) oxygen and magnesium are present in a combined amount of at least 70 atomic %; (b) carbon is present in an amount of no more than 30 atomic %; and/or (c) fluoride is present in an amount of no more than 8 atomic %, wherein atomic % is measured by XPS depth profiling.

Abstract: A method for locally creating effectively homogeneous or “clean” magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength.

Abstract: A method for locally creating effectively homogeneous or “clean” magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength. The method of imaging comprises: a) providing a functional approximation of an inhomogeneous static magnetic field strength B0 (r) at a spatial position r; b) providing a temporal functional approximation of Gshim(t) with i basis functions and j variables for each basis function, resulting in vij variables; c) providing a measured value ?, which is an temporally accumulated dephasing due to the inhomogeneities of B0 (r); and d) minimizing a difference in the local dephasing angle (I) by varying the vij variables to form a set of minimized vij variables. The method requires calibration of the static fields prior to minimization, but may thereafter he implemented without such calibration, may he used in open or closed systems, and potentially portable systems.

Abstract: Methods and systems for compensating for static magnetic field inhomogeneities during nuclear magnetic resonance detection are disclosed. Application of radio frequency pulses and/or magnetic field gradients may be used to correct for spin dephasing caused by the inhomogeneities. The methods and system may be used to improve signal-to-noise ratios in NMR and MRI systems where magnetic field inhomogeneity may have an effect.