Friday, July 16, 2010


Magnetic levitation is well known for its application in mass transport and Maglev trains are known to attain speeds of more than 500 kmph while under vacuum speeds attainable has been calculated at 6400 kmph. As air transport mode can attain speeds as high as 900 kmph, the terrestrial fast trains are not very popular besides being more expensive. Magnetic levitation also known as Maglev or Magnetic Suspension refers to suspending an object with no support other than the magnetic fields and the gravitational pull downwards is counteracted by the magnetic force created using magnets. According to Einstein's theorem static ferromagnets cannot stably levitate against gravity but diamagnetic materials or eddy currents can achieve this. Application of Maglev in food processing is a new dimension and if it can be useful in fast analytical tasks, same is to be welcomed.

"When one thinks of magnetic levitation, or maglev, one generally thinks of insanely fast floating trains or possibly even levitating cans and bottles. Well, scientists are reporting the development of a new use for the technology as an inexpensive sensor for analyzing food, water and other beverages. Measurements of a substance's density are important in the food industry, health care and other settings because they provide key information about chemical composition. Density measurements, for instance, can determine the sugar content of soft drinks, the amount of alcohol in wine, or whether irrigation water contains too much salt to use on a farmer's field. Harvard University's George Whitesides, Ph. D. and colleagues have developed a special sensor that they say is simpler, less expensive and easier to use than devices currently used for making those measurements. The sensor uses maglev to suspend solid or liquid samples and measure their density. About the size of an ice cube, the sensor consists of a fluid-filled container with magnets at each end positioned with like poles facing each other. Samples of different materials can be placed inside, and measuring the vertical position of the suspended object provides a measure of its density. The scientists showed that the device could quickly estimate the salt content of different water samples and the relative fat content in different kinds of milk, cheese, and peanut butter".

The claim that Maglev based analytical tool is easier to use and more cost effective can ensure its fast acceptance by the quality control personnel in food industry and research institutions. The fact that it does not require any complicated electric or electronic gadgets lends itself to wide spread use if validated by independent confirmation studies. Probably proper standardization may be required for different materials to evolve reference data for comparison and reproducible results can be achieved only when easy to handle universal instruments are designed and manufactured for use by the food industry for a wide spectrum of products.


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