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X-ray Microtomography
In radiography, X-ray microtomography uses X-rays to create cross-sections of a physical object that can be used to recreate a virtual model (3D model) without destroying the original object. It is similar to tomography and X-ray computed tomography. The prefix ''micro-'' (symbol: μ) is used to indicate that the pixel sizes of the cross-sections are in the micrometre range. These pixel sizes have also resulted in creation of its synonyms high-resolution X-ray tomography, micro-computed tomography (micro-CT or μCT), and similar terms. Sometimes the terms high-resolution computed tomography (HRCT) and micro-CT are differentiated, but in other cases the term high-resolution micro-CT is used. Virtually all tomography today is computed tomography. Micro-CT has applications both in medical imaging and in industrial computed tomography. In general, there are two types of scanner setups. In one setup, the X-ray source and detector are typically stationary during the scan while the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross Section (geometry)
In geometry and science, a cross section is the non-empty intersection (set theory), intersection of a solid body in three-dimensional space with a Plane (geometry), plane, or the analog in higher-dimensional spaces. Cutting an object into slices creates many parallel cross-sections. The boundary of a cross-section in three-dimensional space that is parallel to two of the Cartesian coordinate system, axes, that is, parallel to the plane determined by these axes, is sometimes referred to as a contour line; for example, if a plane cuts through mountains of a raised-relief map parallel to the ground, the result is a contour line in two-dimensional space showing points on the surface of the mountains of equal elevation. In technical drawing a cross-section, being a Planar projection, projection of an object onto a plane that intersects it, is a common tool used to depict the internal arrangement of a 3-dimensional object in two dimensions. It is traditionally crosshatched with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, known as clinical trials, and whole plants. Definition ''In vitro'' (Latin language, Latin for "in glass"; often not italicized in English usage) studies are conducted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Ancient Numeral Systems
Number systems have progressed from the Finger-counting, use of fingers and tally marks, perhaps more than 40,000 years ago, to the use of sets of glyphs able to represent any conceivable number efficiently. The earliest known unambiguous notations for numbers emerged in Mesopotamia about 5000 or 6000 years ago. Prehistory Counting initially involves the fingers, given that digit-tallying is common in number systems that are emerging today, as is the use of the hands to express the numbers five and ten. In addition, the majority of the world's number systems are organized by tens, fives, and twenties, suggesting the use of the hands and feet in counting, and cross-linguistically, terms for these amounts are etymologically based on the hands and feet. Finally, there are neurological connections between the parts of the brain that appreciate quantity and the part that "knows" the fingers (finger gnosia), and these suggest that humans are neurologically predisposed to use their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay Tablet
In the Ancient Near East, clay tablets (Akkadian language, Akkadian ) were used as a writing medium, especially for writing in cuneiform, throughout the Bronze Age and well into the Iron Age. Cuneiform characters were imprinted on a wet clay tablet with a stylus often made of Reed (plant), reed (reed pen). Once written upon, many tablets were dried in the sun or air, remaining fragile. Later, these unfired clay tablets could be soaked in water and recycled into new clean tablets. Other tablets, once written, were either deliberately fired in hot kilns, or inadvertently fired when buildings were burnt down by accident or during conflict, making them hard and durable. Collections of these clay documents made up the first archives. They were at the root of the first library, libraries. Tens of thousands of written tablets, including many fragments, have been found in the Middle East. Most of the documents on tablets that survive from the Minoan civilization, Minoan and Mycenaean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herculaneum Papyri
The Herculaneum papyri are more than 1,800 papyrus scrolls discovered in the 18th century in the Villa of the Papyri in Herculaneum. They had been Carbonization, carbonized when the villa was engulfed by the eruption of Mount Vesuvius in 79 AD. The papyri, containing a number of Greek Philosophy, Greek philosophical texts, come from the only surviving library from antiquity that exists in its entirety.Interview with Daniel Delattre: the Herculaneum scrolls given to Consul Bonaparte (2010), Napoleon.org However, reading the scrolls is extremely difficult, and can risk destroying them. The evolution of techniques to do this continues. The majority of classical texts referred to by other classical authors are lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
En-Gedi Scroll
The En-Gedi Scroll, also called the En-Gedi Leviticus Scroll (EGLev) is an ancient Hebrew parchment found in 1970 at Ein Gedi, Israel. Radiocarbon testing dates the scroll to the third or fourth century CE (88.9% certainty for 210–390 CE), although there is disagreement over whether the evidence from the writing itself supports that date. The scroll was discovered to contain a portion of the biblical Book of Leviticus, making it the earliest copy of a Pentateuchal book ever found in a Torah ark. The deciphered text fragment is identical to what was to become, during the Middle Ages, the standard text of the Hebrew Bible, known as the Masoretic Text, which it precedes by several centuries. Damaged by a fire in approximately 600 CE, the scroll is badly charred and fragmented and required noninvasive scientific and computational techniques to virtually unwrap and read, which was completed in 2015 by a team led by Brent Seales of the University of Kentucky. Dating Radiocarbon dat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segmentation (image Processing)
In digital image processing and computer vision, image segmentation is the process of partitioning a digital image into multiple image segments, also known as image regions or image objects ( sets of pixels). The goal of segmentation is to simplify and/or change the representation of an image into something that is more meaningful and easier to analyze. Linda G. Shapiro and George C. Stockman (2001): "Computer Vision", pp 279–325, New Jersey, Prentice-Hall, Image segmentation is typically used to locate objects and boundaries (lines, curves, etc.) in images. More precisely, image segmentation is the process of assigning a label to every pixel in an image such that pixels with the same label share certain characteristics. The result of image segmentation is a set of segments that collectively cover the entire image, or a set of contours extracted from the image (see edge detection). Each of the pixels in a region are similar with respect to some characteristic or computed pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volume Rendering
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set, typically a 3D scalar field. A typical 3D data set is a group of 2D slice images acquired by a CT, MRI, or MicroCT scanner. Usually these are acquired in a regular pattern (e.g., one slice for each millimeter of depth) and usually have a regular number of image pixels in a regular pattern. This is an example of a regular volumetric grid, with each volume element, or voxel represented by a single value that is obtained by sampling the immediate area surrounding the voxel. To render a 2D projection of the 3D data set, one first needs to define a camera in space relative to the volume. Also, one needs to define the opacity and color of every voxel. This is usually defined using an RGBA (for red, green, blue, alpha) transfer function that defines the RGBA value for every possible voxel value. For example, a volu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomviz
tomviz is an open source software platform for reproducible volumetric visualization and data processing. The platform is designed for a wide range scientific applications but is especially tailored to high-resolution electron tomography, with features that allow alignment and reconstruction of nanoscale materials. The tomviz platform allows graphical analysis of 3D datasets, but also comes packaged with Python, NumPy, and SciPy SciPy (pronounced "sigh pie") is a free and open-source Python library used for scientific computing and technical computing. SciPy contains modules for optimization, linear algebra, integration, interpolation, special functions, fast Fourier ... tools to allow advanced data processing and analysis. Current version is 1.10.0. In 2022 the tomviz platform was used to enable 3D visualization of specimens during an electron or cryo-electron tomography experiment. Tomviz is built with multi-threaded data analysis pipeline runs dynamic visualizations that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sara Bals
Sara Bals (born 1977) is a Belgian nanoscientist known for her research on electron tomography and its application in the study of nanomaterials such as perovskite nanocrystals. She is a professor of electron microscopy for materials science at the University of Antwerp. Education and career Bals was born 25 August 1977 in Antwerp. She was educated in physics at the University of Antwerp, earning a master's degree in 1999 and completing her Ph.D. there in 2003. Her dissertation was ''Optimisation of superconducting thin films and tapes by transmission electron microscopy''. After postdoctoral research in the National Center for Electron Microscopy at Lawrence Berkeley National Laboratory and at the University of Antwerp, she became an assistant professor at the University of Antwerp in 2007. She was promoted to associate professor in 2012 and full professor in 2018. Recognition Bals was elected to the Royal Flemish Academy of Belgium for Science and the Arts The Royal Flem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isotropy
In physics and geometry, isotropy () is uniformity in all orientations. Precise definitions depend on the subject area. Exceptions, or inequalities, are frequently indicated by the prefix ' or ', hence ''anisotropy''. ''Anisotropy'' is also used to describe situations where properties vary systematically, dependent on direction. Isotropic radiation has the same intensity regardless of the direction of measurement, and an isotropic field exerts the same action regardless of how the test particle is oriented. Mathematics Within mathematics, ''isotropy'' has a few different meanings: ; Isotropic manifolds: A manifold is isotropic if the geometry on the manifold is the same regardless of direction. A similar concept is homogeneity. ; Isotropic quadratic form: A quadratic form ''q'' is said to be isotropic if there is a non-zero vector ''v'' such that ; such a ''v'' is an isotropic vector or null vector. In complex geometry, a line through the origin in the direction of an is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
