Visualizing Electromagnetic Vacuum by MRI

Abstract

Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface decay exponentially inside the conductor, 1-3 leading to a virtual EM vacuum at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present the first visualization of a virtual EM vacuum inside a bulk metal strip by MRI, amongst several novel findings.We uncover unexpected MRI intensity patterns arising from two orthogonal pairs of faces of a metal strip, and derive formulae for their intensity ratios, revealing differing effective elemental volumes (voxels) underneath these faces.Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively.Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expected to grow in importance. The fundamental nature of results presented here may impact bulk metal MRI and CSI across many fields.

Bromamine-T (TsNBrNa): A Biologically Significant, Versatile Bromo-Organic Reagent

“…Chandrashekar et al investigated the Ru(III)-catalysed oxidation of nicotinamide in HCl at 303 K using bromamine-T (BAT) as the oxidant (Scheme 74). 103 Their study revealed that the rate of the reaction follows first-order kinetics in terms [BAT] and [Ru(III)], whereas, the reaction rate exhibits inverse fractional-order dependence based on [H + ] and fractional-order dependence with respect to [nicotinamide]. The dielectric constant and the addition of halide ions and p-toluenesulfonamide did not enforce any significant impact on the reaction rate.…”

“…Scheme 73 Oxidation of piperazines by bromamine-T Chandrashekar et al investigated the Ru(III) catalysed oxidation of nicotinamide in HCl medium at 303 K using bromamine-T (BAT) as an oxidant (Scheme 74). 103 The study revealed that rate of the reaction follows first-order kinetics in terms of BAT and…”

“…101 Gowda and his colleagues investigated the kinetics behind the oxidation of piperazine, 1-methylpiperazine, and 1ethylpiperazine by bromamine-T (BAT) in buffered acidic medium at 303 K (Scheme 73). 102 The reaction follows first-order kinetics in terms of [BAT]0 and [piperazine]0, and inverse fractional-order kinetics with respect to [H + ]. It was observed that the addition of halide ions and the reaction product, i.e., ptoluenesulfonamide, along with the variation of the ionic strength of the medium did not showcase any significant impact on the rate.…”