* Filtration differs from removal of magnetic contaminants from fluids with magnets ( typically lubrication oil, coolants and fuel oils ), because there is no filter medium.

A ribbon tweeter uses a very thin diaphragm ( often of aluminum, or perhaps metalized plastic film ) which supports a planar coil frequently made by deposition of aluminium vapor, suspended in a powerful magnetic field ( typically provided by neodymium magnets ) to reproduce high frequencies.

Current third-generation synchrotron radiation sources are typically heavily based upon these insertion devices, when straight sections in the storage ring are used for inserting periodic magnetic structures ( composed of many magnets that have a special repeating row of N and S poles ) that force the electrons into a sinusoidal path or helical path.

The sensor is typically a set of one or more magnets mounted on the output shaft or ( in transaxles ) differential crownwheel, or a toothed metal disk positioned between a magnet and a magnetic field sensor.

When a metal fin ( typically copper or a copper / aluminum alloy ) passes between the rows of magnets, eddy currents are generated in the fin, which creates a magnetic field opposing the fin's motion.

This can be addressed with external magnets, but more often the confinement area is wrapped in a conductor, typically copper.

The magnetic field typically produced by rare-earth magnets can be in excess of 1. 4 teslas, whereas ferrite or ceramic magnets typically exhibit fields of 0. 5 to 1 tesla.

The most recent development in cryogenics is the use of magnets as regenerators as well as refrigerators.

Helium is used in cryogenics ( its largest single use, absorbing about a quarter of production ), particularly in the cooling of superconducting magnets, with the main commercial application being in MRI scanners.

Hall effect keyboards use magnets and Hall effect sensors instead of an actual switch.

A very common source of magnetic field shown in nature is a dipole, with a " South pole " and a " North pole ", terms dating back to the use of magnets as compasses, interacting with the Earth's magnetic field to indicate North and South on the globe.

Postgate later recalled they undertook around 26 of these programs live-to-air, which were made harder by the production problems encountered by the use and restrictions of using magnets.

Spitzer's concept used the mechanical arrangement of the confinement area to achieve this goal, while more modern systems use a variety of mechanical shapes or magnets to the same end.

For cost reasons synchronous linear motors rarely use commutators, so the rotor often contains permanent magnets, or soft iron.

The larger radius allows the use of numerous magnets, each of which imparts angular momentum and so allows particles of higher velocity ( mass ) to be kept within the bounds of the evacuated pipe.

HTS has application in scientific and industrial magnets, including use in NMR and MRI systems.

Given the low cost of the materials and manufacturing methods, inexpensive magnets ( or non-magnetized ferromagnetic cores, for use in electronic components such as radio antennas, for example ) of various shapes can be easily mass-produced.

The use of magnets rather than a direct electric current to the brain reduced the discomfort of the procedure and research and allowed mapping of the cerebral cortex and its connections.

Due to wartime needs of copper for use in ammunition and other military equipment during World War II, including windings for massive uranium gas separation magnets as part of the Manhattan Project, the United States Mint researched various ways to limit dependence and meet conservation goals on copper usage.

* 2006-China's EAST test reactor is completed, the first tokamak experiment to use superconducting magnets to generate both the toroidal and poloidal fields.

Research and a demonstration proof of concept in 2001 succeeded in applying commercial-grade materials and permanent magnets at room temperatures to construct a magnetocaloric refrigerator which promises wide use.

In its simplest ( and most commonly used ) form, the railgun differs from a traditional homopolar motor in that no use is made of additional field coils ( or permanent magnets ).

All pickups use magnets to produce a magnetic field around the strings, and induce an electrical current in the coils as the strings vibrate.

These measures include carefully sifting the grain before it is milled or ground to remove stones which could strike sparks from the millstones, and the use of magnets to remove metallic debris able to strike sparks.

Because magnets degrade with time, induction motors use short-circuited rotors ( instead of a magnet ) which follow the rotating magnetic field of a multicoiled stator.

The sword was meant to be held on Cloud's back with the use of magnets, and have a small chain.

In more recent decades, some liquid helium has been used as a cryogenic refrigerant, and liquid helium is produced commercially for use in superconducting magnets such as those used in magnetic resonance imaging ( MRI ), nuclear magnetic resonance ( NMR ), and experiments in physics.

The idea of the system is to use the force of magnets, whose position is adjustable, to regulate the touch-weight of the keys, rather than fixed weights.

The strength and magnetic field homogeneity on neodymium magnets has also opened new applications in the medical field with the introduction of open magnetic resonance imaging ( MRI ) scanners used to image the body in radiology departments as an alternative to superconducting magnets that use a coil of superconducting wire to produce the magnetic field.

One of the most challenging use of SC magnets is in the LHC particle accelerator.

These magnets are widely used in such products as microphones, professional loudspeakers, in-ear headphones, and computer hard disks, where low magnet mass or volume, or strong magnetic fields are required.

Neodymium magnets appear in products such as microphones, professional loudspeakers, in-ear headphones, guitar and bass guitar pick-ups and computer hard disks where low mass, small volume, or strong magnetic fields are required.

However, a new low cost magnet-Mn-Al alloy has been developed and is now dominating the low-cost magnets field.

When neodymium – iron – boron permanent magnets are used, levitation is achieved at low speeds.

Therefore ' soft ' magnetic materials with low hysteresis, such as silicon steel, rather than the ' hard ' magnetic materials used for permanent magnets, are usually used in cores.

The architectural model builders enlisted the help of the visual impaired while creating the model, and utilized various unconventional materials, including magnets to make breakaway lamp posts, sandpaper to indicate detectable warnings, raised crosswalk markings to indicate the crosswalk, fuzzy grass, and everything on the model was labeled with both large text and Braille for low vision people to understand the plans for the bridge.

Coupled to poor design and low quality construction, some of the blocks created as many problems as they solved and became magnets for crime and deprivation.

* increasingly in specialist scientific magnets, particularly where size and electricity consumption are critical ( while HTS wire is much more expensive than LTS in these applications, this can be offset by the relative cost and convenience of cooling ); the ability to ramp field is desired ( the higher and wider range of HTS's operating temperature means faster changes in field can be managed ); or cryogen free operation is desired ( LTS generally requires liquid helium that is becoming more scarce and expensive ).

Furthermore, MgB < sub > 2 </ sub > superconducts at temperatures higher than LTS ( its critical temperature is 39 K, compared with less than 10 K for NbTi and 18. 3 K for Nb < sub > 3 </ sub > Sn ), introducing the possibility of using it at 10-20 K in cryogen-free magnets or perhaps eventually in liquid hydrogen.

The maximum usable temperature is highest for alnico magnets at over, around for ferrite and SmCo, about for NIB and lower for flexible ceramics, but the exact numbers depend on the grade of material.

At present, however, the superconducting magnets that are used in the process have to themselves be cooled down to the temperature of liquid nitrogen, or with even colder, and relatively expensive, liquid helium.

To keep the helium from boiling away, the cryostat is usually constructed with an outer jacket containing ( significantly cheaper ) liquid nitrogen at 77 K. One of the goals of the search for high temperature superconductors is to build magnets that can be cooled by liquid nitrogen alone.

In 1986, the discovery of high temperature superconductors by Georg Bednorz and Karl Müller energized the field, raising the possibility of magnets that could be cooled by liquid nitrogen instead of the more difficult to work with helium.

Anisotropic alnico magnets are oriented by heating above a critical temperature, and cooling in the presence of a magnetic field.

To address these requirements, temperature compensated magnets were developed in the late 1970s.

For conventional SmCo magnets, Br decreases as temperature increases.

Conversely, for GdCo magnets, Br increases as temperature increases within certain temperature ranges.

They are generally ranked similarly in strength to neodymium magnets, but have higher temperature ratings and higher coercivity.

These samarium – cobalt magnets generally have a reversible temperature coefficient of-0. 05 %/° C.

To address these requirements, temperature compensated magnets were developed in the late 1970s.

For conventional SmCo magnets, B < sub > r </ sub > decreases as temperature increases.

Conversely, for GdCo magnets, B < sub > r </ sub > increases as temperature increases within certain temperature ranges.

Single-molecule magnets or SMMs are a class of metalorganic compounds, that show superparamagnetic behavior below a certain blocking temperature at the molecular scale.

Some important properties used to compare permanent magnets are: remanence ( B < sub > r </ sub >), which measures the strength of the magnetic field ; coercivity ( H < sub > ci </ sub >), the material's resistance to becoming demagnetized ; energy product ( BH < sub > max </ sub >), the density of magnetic energy ; and Curie temperature ( T < sub > c </ sub >), the temperature at which the material loses its magnetism.

Rare earth magnets have higher remanence, much higher coercivity and energy product, but ( for neodymium ) lower Curie temperature than other types.