On the comparison of results regarding the post-Newtonian approximate treatment of the dynamics of extended spinning compact binaries

A brief review is given of all the Hamiltonians and effective potentials calculated hitherto covering the post-Newtonian (pN) dynamics of a two body system. A method is presented to compare (conservative) reduced Hamiltonians with nonreduced potentials directly at least up to the next-to-leading-pN order.Comment: Conference proceedings for the 7th International Conference on Gravitation and Cosmology (ICGC2011), 4 page

A frequency-adjustable electromagnet for hyperthermia measurements on magnetic nanoparticles

We describe a low-cost and simple setup for hyperthermia measurements on colloidal solutions of magnetic nanoparticles (ferrofluids) with a frequency-adjustable magnetic field in the range 5-500 kHz produced by an electromagnet. By optimizing the general conception and each component (nature of the wires, design of the electromagnet), a highly efficient setup is obtained. For instance, in a useful gap of 1.1 cm, a magnetic field of 4.8 mT is generated at 100 kHz and 500 kHz with an output power of 3.4 W and 75 W, respectively. A maximum magnetic field of 30 mT is obtained at 100 kHz. The temperature of the colloidal solution is measured using optical fiber sensors. To remove contributions due to heating of the electromagnet, a differential measurement is used. In this configuration the sensitivity is better than 1.5 mW at 100 kHz and 19.3 mT. This setup allows one to measure weak heating powers on highly diluted colloidal solutions. The hyperthermia characteristics of a solution of Fe nanoparticles are described, where both the magnetic field and the frequency dependence of heating power have been measured

On the comparison of results regarding the post-Newtonian approximate treatment of the dynamics of extended spinning compact binaries

A brief review has been given of all the Hamiltonians, and effective potentials calculated hitherto covering the post-Newtonian (pN) dynamics of a two-body system. A method has been presented to compare (conservative) reduced Hamiltonians with non-reduced potentials directly at least up to the next-to-leading-pN order

Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes

We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power

An investigation of the laser-induced zircon 'matrix effect'

This study aims to improve our understanding of the current limitations to high-precision U-Pb analysis of zircon by LA-ICP-MS by investigating the underlying causes of variation in ablation behaviour between different zircon matrices. Multiple factors such as: the degree of accumulated radiation damage, trace element composition; crystal colour; and crystallographic orientation are all systematically investigated. Due to the marked decrease in elastic moduli of natural zircon crystals with increasing radiation damage, the accumulation of this damage is the dominant factor controlling the rate of ablation for partially damaged to highly metamict zircon samples. There are slight differences, however, in ablation behaviour between highly crystalline matrices that cannot be attributed solely to differences in the degree of accumulated radiation damage. These differences are associated with structural weakening (i.e., decrease in elastic moduli and overall lower mechanical resistance) caused by an increasing degree of cation substitution in some of the zircon samples. Effects of crystallographic orientation and of crystal opacity (i.e., colour) on ablation behaviour are negligible compared to the combined influences of accumulated radiation damage and trace element substitution into the zircon structure. Experiments performed on natural and annealed zircon grains reveal that the reduction in ablation rates observed for the treated samples compared to the untreated grains is proportional to the degree of structural reconstitution achieved after annealing. Thermal annealing of natural zircon at temperatures >1000 °C results in much more uniform ablation characteristics. This 'homogenisation' of ablation behaviour between zircon matrices produces a decrease in the laser-induced matrix effects and subsequent improvement in the accuracy of 206Pb/238U ratio determinations by LA-ICP-MS

Aligned Spins: Orbital Elements, Decaying Orbits, and Last Stable Circular Orbit to high post-Newtonian Orders

In this article the quasi-Keplerian parameterisation for the case that spins and orbital angular momentum in a compact binary system are aligned or anti-aligned with the orbital angular momentum vector is extended to 3PN point-mass, next-to-next-to-leading order spin-orbit, next-to-next-to-leading order spin(1)-spin(2), and next-to-leading order spin-squared dynamics in the conservative regime. In a further step, we use the expressions for the radiative multipole moments with spin to leading order linear and quadratic in both spins to compute radiation losses of the orbital binding energy and angular momentum. Orbital averaged expressions for the decay of energy and eccentricity are provided. An expression for the last stable circular orbit is given in terms of the angular velocity type variable $x$.Comment: 30 pages, 2 figures, v2: update to match published versio