OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P. O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Lei Dong Name of the dissertation Manuscript submitted 14.10.2008 Manuscript revised 12.12.2008 Date of the defence 19.01.2009 at 13 o’clock, TKK main building, Otakaari 1, lecture hall E Article dissertation (summary + original articles) Monograph Faculty Department Field of researc...

From an investigation of structure it is shown that there exists a large group of dipolar organic solids whose dipoles have two equilibrium positions with opposite dipole direction. To calculate the dielectric properties Onsager’s theory has been extended and developed into a systematic approximation which converges above a critical temperature. To derive the local field acting on a dipole we h...

A ferrite-dielectric metamaterial composed of dielectric and ferrite cuboids has been investigated by experiments and simulations. By interacting with the electromagnetic wave, the Mie resonance can take place in the dielectric cuboids and the ferromagnetic precession will appear in the ferrite cuboids. The magnetic field distributions show the electric Mie resonance of the dielectric cuboids c...

there are described nanocomposites based on ultra high molecular weight polyethylene and graphite nanoplates prepared by in-situ polymerization method. it is carried out a comprehensive study of electric properties of these composites, including direct current (dc) and alternating current (ac) properties. there is explored dependence of the conductivity and dielectric permeability on filler con...

As new algorithms for microwave imaging emerge, it is important to have standard accurate benchmarking tests. Currently, most researchers use homogeneous phantoms for testing new algorithms. These simple structures lack the heterogeneity of the dielectric properties of human tissue and are inadequate for testing these algorithms for medical imaging. To adequately test breast microwave imaging a...

This paper presents a structured model of the dielectric properties of the corneal tissue at microwave frequencies, based on the fine structure and chemical composition of its constituents. This is accomplished by appropriately combining the known properties of tissue substructures using mixing rules, in order to obtain the effective macroscopic properties of the medium. The presented approach ...

Temporal and spatial characteristics of microwave dielectric properties and water status of several forest species were investigated during the 1990 and 1991 growing seasons as part of the NASA FED MAC. Data presented were acquired from Durham, New Hampshire (white pine, eastern hemlock, and American beech), and Howland, Maine (eastern hemlock and red spruce). Dielectric properties of trunk woo...

Being dependent on temperature and frequency, dielectric properties are related to various types of food. Predicting multiple physical characteristics of agri-food products has been the main objective of non-destructive assessment possibilities executed in many studies on horticultural products and food materials. This review manipulates the basic fundamentals of dielectric properties with thei...

The efficacy of emerging microwave breast cancer detection and treatment techniques will depend, in part, on the dielectric properties of normal breast tissue. However, knowledge of these properties at microwave frequencies has been limited due to gaps and discrepancies in previously reported small-scale studies. To address these issues, we experimentally characterized the wideband microwave-fr...

A new DEP spectroscopy method and supporting theoretical model is developed to systematically quantify the dielectric properties of nanoparticles using continuously pulsed DEP collection rates. Initial DEP collection rates, that are dependent on the nanoparticle dielectric properties, are an attractive alternative to the crossover frequency method for determining dielectric properties. The new ...