Sentences with phrase «magnetite particles»

There are two main theoretical models, one based on small magnetite particles that may reorient in an external magnetic field and the other based on the idea that upon photo excitation a certain type of molecules in the eye of a bird support a radical pair formed by two electrons which evolve under the joint action of the Zeeman interaction with the external magnetic field and the hyperfine interaction with the supporting molecule.

The magnetite particles are thought to act like microscopic compass needles, relaying information to the nervous system by straining or twisting receptors in cells as they attempt to align with the Earth's magnetic field.

The two new papers, one published this week in Geochimica et Cosmochimica Acta, the other accepted for publication in the same journal, provide nonbiological explanations for the magnetite particles and the PAHs.

In the paper published this week, the magnetite particles in ALH84001 are analysed by geoscientists Ralph Harvey of Case Western Reserve University in Cleveland, Ohio, and Harry McSween of the University of Tennessee in Knoxville, working with John Bradley of MVA in Norcross, Georgia, a company which specialises in microscopic analysis.

These temporarily magnetise the magnetite particles, now attached to carboxylic molecules, making them form long chains, joined at their «poles», which aggregate in clumps a millimetre or two across.

Debate on how birds sense geomagnetic fields has largely revolved around magnetite particles found in various parts of their heads.

When magnetite particles are exposed to an EMF, they start to vibrate.

Not exact matches

Magnetospirillum cells contain a number of small particles of magnetite (Fe3O4), each approx. 45 nanometers wide.

They think the skill may be related to small particles of magnetite, an iron oxide, located in two masses of nerve tissue in the forward part of the lobsters» bodies.

First, the surface charge on a particle of magnetite (a form of iron oxide) depends on the pH of the solution surrounding it: below pH 6 it is positive, and above it is negative.

FIG-mg18783801.GIF The screened sewage flows to a tank where it is mixed with powdered magnetite, along with aluminium sulphate to weaken the forces that stabilise the suspension of sewage particles.

But locating the cells that contain the 50 - nanometer particles has been like looking for a needle in a haystack, in part because the tissue - dissolving methods used to identify magnetite turn biological samples to mush.

The findings are consistent with the idea, first proposed nearly 40 years ago, that animals have tiny magnetic particles of an iron - containing compound called magnetite in their bodies.

The particles appeared in a different shape than naturally occurring magnetite and were coupled to other similar metals.