Electronics & Semiconductors
Waves, whether they are light waves, sound waves, or any other kind, travel in the same manner in forward and reverse directions—this is known as the principle of reciprocity. If we could route waves in one direction only—breaking ...
May 21, 2020
0
140
Hardware
A team of scientists has taken steps to create a new form of digital data storage, a "Racetrack Memory," which opens the possibility to both bolster computer power and lead to the creation of smaller, faster, and more energy ...
May 5, 2020
1
134
Energy & Green Tech
A technique based on the principles of MRI has allowed researchers to observe not only how next-generation batteries for large-scale energy storage work, but also how they fail, which will assist in the development of strategies ...
Mar 2, 2020
0
87
Internet
Researchers at Pohang University of Science and Technology (POSTECH) have advanced online security by integrating an AI-based metasurface with oblique helicoidal cholesteric liquid crystals.
Apr 15, 2024
0
21
Energy & Green Tech
An increasing number of electric cars are being sold, consequently raising the quantity of produced electric motors. At the end of their useful life, these electric motors are shredded and then recycled. The individual components ...
Jan 2, 2024
0
15
Engineering
Superconductors make highly efficient electronics, but the ultralow temperatures and ultrahigh pressures required to make them work are costly and difficult to implement. Room-temperature superconductors promise to change ...
Mar 28, 2023
0
6
Energy & Green Tech
A new device harvests two types of energy during the daytime, making it cool on one end and hot on the other, to generate electricity around the clock. With further improvements, the device could be used in off-grid Internet-of-things ...
Mar 8, 2022
0
43
Automotive
General Motors has taken two more steps to make sure it has the raw materials for the transition from petroleum to battery power, this time lining up magnets for electric vehicle motors.
Dec 9, 2021
0
3
Robotics
The rhythmic motions of hair-like cilia move liquids around cells or propel the cells themselves. In nature, cilia flap independently, and mimicking these movements with artificial materials requires complex mechanisms. Now, ...
May 19, 2021
0
5
Automotive
Fiat Chrysler is recalling nearly 132,000 vehicles worldwide to fix a problem that could cause some diesel engines to stall.
Aug 24, 2020
0
5
A magnet (from Greek μαγνήτις λίθος magnḗtis líthos, "Magnesian stone") is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials and attracts or repels other magnets.
A permanent magnet is one made from a material that stays magnetized. An example is a magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some rare earth metals and some of their alloys (e.g. Alnico), and some naturally occurring minerals such as lodestone.
Although ferromagnetic (and ferrimagnetic) materials are the only ones with an attraction strong enough to a magnet to be commonly considered "magnetic", all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
An electromagnet is made from a coil of wire which acts as a magnet when an electric current passes through it, but stops being a magnet when the current stops. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.
The overall strength of a magnet is measured by its magnetic moment, while the local strength of the magnetism in a material is measured by its magnetization.
This text uses material from Wikipedia, licensed under CC BY-SA
