The magnetic properties of a Magnet
The magnetic properties of a magnet may be lost even this process takes a long time. A samarium-cobalt magnet, for example, could take about 700 years only to lose half its magnetic force.
The magnet and everything that surrounds it, magnetic phenomena and their properties were discovered by the ancient Greeks. The story is first observed in Magnesia, a city of Asia Minor which later gave its name to the magnets. The magnetism is associated with the orbital and rotational motion of electrons in atoms. Some specific provisions of these shifts, such as iron atoms, leading to intense magnetic materials. If the electrons are highly ordered, there is magnetism.
For all these reasons, the magnet is also vulnerable to heat and falls. In addition, demagnetization can occur on contact. Each time you paste something to a magnet lose some of its properties, and strong shocks can dislodge the particles causing the magnet to lose some of its power. Thus, the magnet field becomes misaligned and is damaging to their lineup.
Also, magnet loses its power when it achieves the so-called "Curie temperature" (or "Curie Point"). This is the temperature above which a ferromagnetic body loses its magnetism, making it become a purely paramagnetic material. Thus, the Curie temperature is different for each composition. For example, the Curie temperature of a ceramic magnet would be 450 ° C for one of cobalt, 800 ° C, and so on.
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A magnet to discover fraudsters
In times of crisis there are always businesses that are benefiting. This is the case of 'gold rush'. Jewelry stores and businesses to buy gold are rising, and there are always those who want to be benefited by using the trap and this time, sell scrap gold price. To prevent this, the magnet is one of the main tools.
The magnet prevents more 'cheeky' get away with it and sell other metal like gold. A Henry, jeweler by profession, he "slipped" several pieces that were being rolled and lost $ 2,000. "The fat layer was so positive that came outthe acid and the magnet does not attract," says El Mundo. Trinkets whose tracks were not deleted when rubbedagainst the stone. The gold is kept, the iron away. And the magnet attracts the false, but not the real thing. When in doubt despite spending the magnet breaks the jewel Enrique now and see whether it is solid.
Meanwhile, Juan Angel Pujolar, owner of one of these businesses in Madrid, is not exempt from these scams. His business had only been open two days when he paid for a stolen jewels. Of course, he did not know. There is nomagnet that is worth. The protocol dictates that you must complete a police record for each item they buy. Hence, the main tools of this business are the magnet, a box of acids that help to differentiate the karat of gold, police records and money.
When buying gold, buyers need to save the genre for two weeks, at which time the group Theft collate the National Police with the allegations. If a gem matches, the buyer loses it, loses the money already paid. However, many are recovered because a judge finds that the purchase has been legítima.Fuente: The World
The manufacturing process of the magnets
Ever wondered how you make a magnet? The process of magnets is not as complicated as a priori it may seem.All you need is to differentiate the types of magnets exist for each use. The most common magnets usually have present in our daily lives are mostly a fairly simple manufacturing process. To make these magnets need iron powder mixed with other chemicals. After that, proceed to press materials, and thermally treated, thereby achieving iron blocks the chemical composition necessary to achieve the magnets. Once we have obtained the blocks are cut to length depending on what they were going to give. Subsequently, the magnets are cleaned to remove any unnecessary excess material. If necessary rectifying the size of the pieces of the magnets for one reason or another, this is the right time. Now we only have the process of magnetizing the pieces. The magnetization of the pieces we got through the flow of electric current through a coil, where the pieces are magnetized by the magnetic field generated in this process. This results in the magnets. All we need is one last simple step: test the quality of the magnets, for which generally uses a machine called a dynamometer, which measures the strength of the magnets. May also be called newtómetro, being invented by Isaac Newton, and consists of a spring contained in a cylinder of plastic, cardboard or metal, with two hooks, one at each end. Dynamometers have a scale marked in units of force, in the hollow cylinder that surrounds the spring. By hanging weights or exert a force on the lower hook, the lower cylinder cursor moves on the outer scale, indicating the value of force.
How to recycle old advertising magnets that have spent years in the refrigerator?
If someone you believe your advertising magnets and have for many years attached to the refrigerator such as: calendars from past years, numbers of service they have never eaten restaurants and pharmacies that carry the products at home, but never used, then it is time for recycling.
First let's straighten advertising magnets to receive the images. Then we take off the pictures above and leave the surface clean and free of grease if you'll use to glue rubber sheets to the magnet.
There are different types of magnets advertising: there are some in which the image is a plastic sticker as itcomes off in one piece and let the magnet glued ready to paste images without using glue. Others are flimsy paperthat will not peel off in one piece but in pieces, and other advertising magnets seem impossible to separate the paper. If we take off all of a piece, great. If not, we can take off, especially if there is a plastic film on paper andthen soak the magnet advertising, and then with the green sponge and soap to clean the finish. Some magnets can be a little more difficult. There are some who take off and run out of rubber, but others should be washed.
Following these easy steps will have a new advertising magnet last another year more in our renewed fridge.
The compass: that sage magnet
The compass, such as common object used by explorers and adventurers. However, few know that the magnetic field that guides the needle is in the electrical currents in the Earth's molten core about 2900 km. The propertymagnet north-south line is not evident until the 1200 ec
The first use of magnetic needles was presumably in China several centuries before in the old continent. The firstmagnetic needles do not retain magnetization. The discoverer Christopher Columbus knew these drawbacks andremagnetized their needles with a magnet. While permanent properties of magnetite, iron is a strong magnetmagnetized temporarily. During the sixteenth century both types of magnet, hard and soft, were combined toproduce a powerful permanent magnet.
The magnetite, with additions of iron, known as "magnet assembly" was the most potent. For a comparison of thepower of magnets we use two quantities that describe the magnetic properties. One, the magnetic saturation, is the largest magnetic field that can have the material, whether temporary or permanent. the magnetic saturation is a measure of the strength of the magnet when fully magnetized, as this property is a good iron magnet because itsmagnetic saturation is of the order of 20,000 gauss while that of magnetite is less than 4,000.
Another important property of the permanent magnet is related to the opposing magnetic field strength required to demagnetize. This property is called coercivity and can be expressed in gauss. The triumphant material is magnetite whose coercivity is about 200 gauss, while the iron is less than 1. In the case of high coercivity magnetsarmed magnetite iron remains magnetized and high magnetic saturation of iron increases the magnetic field.
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