More recently, rare earths have been driving the growth of green technologies, such as wind power and electric vehicles. These metals generate sound waves in your headphones and boost digital data through space. They also help build some of the world’s strongest, most reliable magnets. They relay signals through fiber-optic cables along the seafloor. They fluoresce to signal that euro banknotes are the real deal. For instance, we rely on rare earths to color our smartphone screens. Rare-earth mining is dirty but key to a climate-friendlier futureīut the most outstanding capabilities of rare earths are their luminescence and magnetism. It captures neutrons to control the production of energy by a reactor’s fuel. Nuclear reactors rely on another: gadolinium. The rare earth cerium can serve as a catalyst to process crude oil into a host of useful products. They also have similar chemical properties. Those last two elements tend to occur in the same ore deposits as lanthanides. Also included in the rare earths are scandium (atomic number 21) and yttrium (atomic number 39). Known as lanthanides, they run from lanthanum to lutetium - atomic numbers 57 through 71. And demand for these metals has been skyrocketing.įifteen rare earths make up a whole row on most periodic tables. Called rare earths, these 17 elements are crucial to nearly all modern electronics. That was, of course, fiction.īack here on Earth, in real life, a group of metallic elements has made possible our own technology-driven society. It also became the basis of an intergalactic civilization. This spice granted people the ability to navigate vast expanses of the cosmos. Mining a precious natural substance called spice melange was a driving theme in that epic space saga. The brain phantom and simulated MR images have been made publicly available on the Internet ().The first volume of Frank Herbert’s Dune series debuted back in 1965. Furthermore, since the same anatomical phantom may be used to drive simulators for different modalities, it is the ideal tool to test intermodality registration algorithms. Since the contribution of each tissue type to each voxel in the brain phantom is known, it can be used as the gold standard to test analysis algorithms such as classification procedures which seek to identify the tissue "type" of each image voxel. The digital brain phantom can be used to simulate tomographic images of the head. This three-dimensional digital brain phantom is made up of ten volumetric data sets that define the spatial distribution for different tissues (e.g., grey matter, white matter, muscle, skin, etc.), where voxel intensity is proportional to the fraction of tissue within the voxel. Since simple objects such as ellipsoids or parallelepipedes do not reflect the complexity of natural brain anatomy, we present the design and creation of a realistic, high-resolution, digital, volumetric phantom of the human brain. Such considerations have become increasingly important with the rapid growth of neuroimaging, i.e., computational analysis of brain structure and function using brain scanning methods such as positron emission tomography and magnetic resonance imaging. Experiments with simulated data permit controlled evaluation over a wide range of conditions (e.g., different levels of noise, contrast, intensity artefacts, or geometric distortion). Although the algorithm must be evaluated on real data, a comprehensive validation requires the additional use of simulated data since it is impossible to establish ground truth with in vivo data. After conception and implementation of any new medical image processing algorithm, validation is an important step to ensure that the procedure fulfills all requirements set forth at the initial design stage.
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