Dielectric-based methods were used to determine nondestructively and simultaneously bulk density and moisture content in shelled peanuts from measurement of their relative complex permittivity at microwave frequencies (7–12 GHz) and 24 C. The first method is based on direct relationships between the two components of the relative complex permittivity (dielectric constant and dielectric loss fac...

The spectral density representation of Bergman [Ann. Phys. 138 (1982) 78] is applied to measurements of bulk permittivity on a composite system with various levels of filler concentration, in order to extract structural information such as shape and spatial arrangement of the filler particles. The composites are paraffin wax filled with metal-coated hollow glass micro-spheres. The inclusions ha...

BACKGROUND Dual-channel transmit technology improves the image quality in cardiovascular magnetic resonance (CMR) at 3 T by reducing the degree of radiofrequency (RF) shading over the heart by using RF shimming. Further improvements in image quality have been shown on a dual-transmit system using high permittivity pads. The aim of this study is to investigate the transmit field (B 1 (+)) homoge...

The research was planned to test electrical properties of polymer films made from polyurethane cationomers with 0-2 wt.% graphene admixture. The cationomers were synthetized in the reaction of 4,4'-methylenebis(phenyl isocyanate), polycaprolactone diol (M = 2000), N-methyldiethanolamine, and formic acid. It was found that addition of approx. 2 wt.% of graphene causes the loss of volume resistiv...

In this paper, we propose a method for designing Photonic Crystal (PhC) devices that consist of dielectric rods with varying size. In the proposed design method, PhC devices are modeled with the Transformation Optics (TO) approach, and then they are optimized using the gradient method. By applying the TO technique, the original device model is transformed into an equivalent model that consists ...

Permittivity is a very important physical parameter for a detailed understanding of interactions in a biological system. However, at the moment no common experimental method is available for measuring the dielectric constants of a microenvironment or on a local level, and one has to rely on theoretical simulations. In this work we can demonstrate that it is experimentally possible to estimate t...

Homogeneous composites, or metamaterials, made of dielectric or metallic particles are known to show magnetic properties that contradict arguments by Landau and Lifshitz [Landau LD, Lifshitz EM (1960) Electrodynamics of Continuous Media (Pergamon, Oxford, UK), p 251], indicating that the magnetization and, thus, the permeability, loses its meaning at relatively low frequencies. Here, we show th...

An analytic method for obtaining bounds on effective properties of composites is applied to the complex permittivity •* of sea ice. The sea ice is assumed to be a two-component random medium consisting of pure ice of permittivity 1⁄2• and brine of permittivity •2. The method exploits the properties of e* as an analytic function of the ratio El/e2 . Two types of bounds on •* are obtained. The fi...

Metamaterials (MM) have been able to make their position strong in the world of electromagnetic in the past years. Researchers have come up with several novel shapes which behave as metamaterials. The characteristic parameters of permittivity ε and the permeability μ were extracted by doing several experimentations and found them to be negative. This paper presents such a new shape namely Criss...

The presented studies are focused on the dependence of paper sheet strength properties on the composition of additives, chitosan, cyanoethyl and carboxymethyl chitosan. Chitosan and its derivatives achieve an improvement in the strength properties of unagged and agged paper sheets. Also, cyanoethyl chitosan improves the dielectric properties of the treated paper sheets. The dielectric study was...