We discuss optical constants in artificial metamaterials showing negative magnetic permeability and electric permittivity and suggest a simple formula for the refractive index of a general optical medium. Using the effective-field theory, we calculate the effective permeability and the refractive index of nanofabricated media composed of pairs of identical gold nanopillars with magnetic respons...

BACKGROUND AND PURPOSE Animal models of acute cerebral ischemia have demonstrated that diffuse blood-brain barrier (BBB) disruption can be reversible after early reperfusion. However, irreversible, focal BBB disruption in humans is associated with hemorrhagic transformation in patients receiving intravenous thrombolytic therapy. The goal of this study was to use a magnetic resonance imaging bio...

High-permeability magnetic shields generate magnetic field noise that can limit the sensitivity of modern precision measurements. We show that calculations based on the fluctuation-dissipation theorem allow quantitative evaluation of magnetic field noise, either from current or magnetization fluctuations, inside enclosures made of high-permeability materials. Explicit analytical formulas for th...

During the development of ferrite-loaded accelerating cavities, the electromagnetic properties of the dispersive ferrite material need to be known. We describe a coaxial short-circuit measurement technique to measure the complex permeability of toroidal-shaped samples (127mm outer and 70mm inner diameter) that are exposed to an external magnetic bias field. The external magnetic bias field is a...

Permeability and coercivity are the most important parameters for the evaluation of soft magnetic materials. The criteria for the softest magnetic materials demand very high permeability and / or extremely low coercivity and these properties necessitate the anisotropy energy and the magnetoelastic energy tend towards zero. These unique demands are fulfilled when the FINEMET type of nanocrystall...

the objective of this research is to represent applicability of surface nuclear magnetic resonance (snmr) in aquifer characterization, based on snmr and electrical resistivity tomography data. snmr is the only geophysical method that directly detects water. two important parameters, porosity and permeability are available through inversion of initial amplitude and decay time constant versus pul...

PURPOSE The present study examines the use of an external magnetic field in combination with the disruption of tight junctions to enhance the permeability of iron oxide nanoparticles (IONPs) across an in vitro model of the blood-brain barrier (BBB). The feasibility of such an approach, termed magnetic field enhanced convective diffusion (MFECD), along with the effect of IONP surface charge on p...