Background/introduction High intensity focused ultrasound (HIFU) ablation of the brain has been increasingly used as a non-invasive treatment for essential tremor and neuropathic pain. However, artifacts arise in magnetic resonance (MR) images as a result of dielectric properties of the water bath coupler and of the tissues being investigated. As radio frequency (RF) waves enter a dielectric me...

The electromagnetic properties of materials are defined from the two following constitutive parameters: permittivity, ε, and permeability, μ; ‘ε’ indicates how the medium reacts when an electric field is applied (field E of the electromagnetic wave), whereas μ indicates how the material behaves further to a magnetic excitation (field H of the electromagnetic wave). To take into account the loss...

Electromagnetic materials with tunable permeability and permittivity are highly desirable for wireless communication and radar technology. However, the tunability of electromagnetic parameters is an immense challenge for conventional materials and metamaterials. Here, we demonstrate a magnetically tunable Mie resonance-based dielectric metamaterials. The magnetically tunable property is derived...

The applicability of the Lifshitz formula is discussed to the case of two thick parallel plates made of real metal. The usual description of the zero-point vacuum oscillations on the background of the frequency-dependent dielectric permittivity is shown to be in contradiction with thermodynamics. Instead, the Lifshitz formula for the Casimir free energy should be reformulated in terms of the re...

A novel method of dielectric sample detection utilizing microwave coupled-line sensor has been presented. The proposed measurement setup composed of two identical baluns and coupled-line section covered by an unknown material has been analyzed and formulas allowing for calculation of effective permittivity have been derived along with simplified calibration procedure. The method allows for dete...

Effects of material and configuration of the internal wall on the performance of wideband channel are investigated by using the Finite Difference Time-Domain (FDTD) method. The indoor wideband channel characteristics, such as the path-loss, Root-Mean-Square (RMS) delay spread and number of the multipath components (MPCs), are presented. The simulated results demonstrate that the path-loss and M...

Recent technological improvements have extended the application range of dielectric permittivity biomass measurements to on-line monitoring of physiological changes during bacterial fermentations. In an industrial fermentation of Bacillus thuringiensis, it is important to verify the intactness of bacterial plasmid content in all steps of culture. Changes in certain plasmid resident properties o...

In this paper, we review the principal theoretical models through which the dielectric function of metals can be described. Starting from the Drude assumptions for intraband transitions, we show how this model can be improved by including interband absorption and temperature effect in the damping coefficients. Electronic scattering processes are described and included in the dielectric function...

Purpose: Non-contrast magnetic resonance angiography (NC-MRA) is an alternative diagnostic tool for assessment of peripheral vascular disease in patients with impaired kidney function. While peripheral NC-MRA based on subtraction of two turbo-spin-echo acquisitions may benefit from increased signal-to-noise ratio at 3T, it also suffers from signal loss in the right femoral artery due to previou...

How can we differentiate between an underground stone and a land mine? We discuss a class of methods for solving such problems. This class of methods concerns globally convergent numerical methods for Coefficient Inverse Problems, unlike conventional locally convergent algorithms. Numerical results are presented modeling imaging of the spatially distributed dielectric permittivity function in a...