Change in impedance of an encircling coil is obtained in the present paper for the case where the electric conductivity and magnetic permeability of a metal cylindrical tube depend on the radial coordinate. The system of equations for the vector potential is solved by means of the Fourier cosine transform. The solution is expressed in terms of improper integral containing modified Bessel functi...

The frequency dependences of complex initial permeability for triplecomponent composite materials based on two different types of ferrite filler (MnZn and NiZn ferrite) and a nonmagnetic polymeric matrix (PVC) were studied in the frequency range of 10 kHz–1 GHz. The frequency dispersion of permeability is discussed by means of a dynamic model based on the superposition of the two types of magne...

Permeability is arguably the most important property in evaluating fluid flow in the reservoir. It is also one of the most difficult parameters to measure in field. One of the main techniques for determining permeability is the application of Nuclear Magnetic Resonance (NMR) logging across the borehole. However, available correlations in literature for estimating permeability from NMR data do n...

Amorphous Fe73B7Si16Nb3Cu1 ribbon was crystallized rapidly by electric current heating under simultaneously applied tensile stress along the ribbon axis. As a result, strong transverse magnetic anisotropy was induced in the ribbon. Dynamic magnetic properties of the ribbons rapidly heated either under the tensile stress or without tensile stress were measured using toroidal cores. Optimal elect...

A theory that takes into account effects of retardation is developed for calculating the effective dielectric constant and magnetic permeability of metal-dielectric composites and photonic crystals containing a metallic component. The effective parameters depend, in general, on the local microgeometry of composites and electromagnetic crystals. For example, in metal-wire crystals the effective ...

A series of Li-Cd ferrite samples of composition Li0.5-x/2CdxBi0.02Fe2.48-x/2O4 for x = 0.0 to 0.7 were prepared by conventional double sintering ceramic technique. From temperature dependent permeability, μ′ at T=TC indicates that the samples have high homogeneity according to Globus et al. The Curie temperature, TC is found to decrease with increasing Cd content. The sample with x=0.7 shows a...

A non-erasable memory based on using differences in the magnetic permeability is demonstrated. The method can potentially store information indefinitely. Initially the high permeability bits were 10–50 μm wide lines of sputtered permalloy (Ni81Fe19) on a glass substrate. In a second writing technique a continuous film of amorphous, high permeability ferromagnetic Metglas (Fe78Si13B9) was sputte...

In this study, the effects of various heat treatments on microstructure, mechanical and magnetic properties of HSLA-100 steel were evaluated. The heat treatments consisted of austenitizing at 900°C for 60 minutes, then quenching by different cooling rates via furnace, air, oil and water; and quenched specimens were aged at 600°C for one hour. Optical and field emission scanning electron m...

In the presence of a strong external field, the vacuum reacts, becoming magnetized and polarized. The index of refraction, magnetic permeability, and dielectric constant of the vacuum are straightforward to calculate using quantum electrodynamic one-loop corrections [1–6]. In this paper, we calculate the magnetic permeability and dielectric tensors of an external electric or magnetic field of a...