The presence of a narrow shape and size distribution for magnetite crystals within magnetotactic organisms suggests strongly that there are species-specific mechanisms that control the process of biomineralization. In order to explore the extent of this control, cultures of Aquaspirillum magnetotacticum in the exponential growth phase were exposed to increasing magnetic pulses with the aim of s...

Two wireless, passive remote query magnetism-based glucose sensors, which operate in combination with a mass and volume changing glucose responsive polymer, are presented. One sensor design is based upon the magnetostatic coupling of magnetically soft thin-film elements; as the polymer volume changes in response to glucose concentration so does the magnetostatic coupling between elements. In re...

A detailed study of the Counter-Rotating Model (CRM) for generic electrostatic (magnetostatic) axially symmetric thin disks without radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating charged dust fluids. We then show that this constra...

We have prepared dilute nanostructured magnetic samples by codeposition of preformed cobalt clusters with a narrow size distribution around 40 atoms per cluster in silver matrices. Magnetoresistance measurements are used to derive information about the magnetic structure of the samples. Effects of cluster size distribution or anisotropy can be neglected in our samples. Deviations from simple La...

Magnetostatic (dipolar) interactions between nanoparticles promise to open new ways to design nanocrystalline magnetic materials and devices if the collective magnetic properties can be controlled at the nanoparticle level. Magnetic dipolar interactions are sufficiently strong to sustain magnetic order at ambient temperature in assemblies of closely-spaced nanoparticles with magnetic moments of...

We analyze the spectrum of a certain singular integral operator on the space (L2(fi))3 where fi is contained in three dimensional Euclidean space and has a Lipschitz continuous boundary. This operator arises in the integral formulation of the magnetostatic field problem. We decompose (L2(fi))3 into invariant subspaces: in one where the operator is the zero map; in one, the identity map; and in ...

A balancing domain decomposition (BDD) method is considered as a preconditioner of the iterative domain decomposition method (DDM) for magnetostatic problems. The BDD method enables us to keep convergence properties of the iterative DDM even if the number of subdomains increases. However, in case of magnetostatic problems, the dimension of the coarse problem required in the BDD procedure depend...