The DNA elements are typically double stranded molecules and connected by cohesive "sticky ends" that are single stranded. The object shapes include cubes and truncated octahedrons. The resultant structures are imaged using X-ray crystallography. An important goal of this work is to make DNA-based nano-sized robots and DNA-based computers. Paper SP.05, a plenary talk.
The magnetocaloric effect is a change in the temperature of a magnetic material because of the change in the surrounding magnetic field. Thus turning on or off a nearby magnet can result in refrigeration. Of all magnetic materials, ferromagnets show the largest and potentially the most practical magnetocaloric effects at temperatures near their ordering (Curie) temperatures. The Curie temperature (named after Pierre Curie) is the temperature at which a material undergoes marked changes in its magnetic properties. Yurij Mozharivskyj, a chemist at McMaster University, is at the ACA meeting to receive the ACA's Etter Award for his research in these materials. He will report on efforts to improve the process.
The magnetocaloric effect can be significantly enhanced when a ferromagnetic ordering is combined with a structural transition. Such effect is known as a giant magnetocaloric effect and was first discovered in Gd5Si2Ge2 and related compounds. Modification of the electron concentration is a powerful tool to tune the structure and magnetism of the compounds.
While currently there are no commercial magnetic refrigerators, there are a few laboratory prototypes, with a rotary magnetic refrigerator developed by the Astronautics Corporation of America in 2001 being the most promising. This rotary magnetic refrigeration, operating on the Gd and Gd-Er materials, can achieve the temperature span of 24oC. Unfortunately, the temperature span decreases with an increase in the heat load. It is predicted that once technology development
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American Institute of Physics