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Topic Review
Beta (Plasma Physics)
The beta of a plasma, symbolized by β, is the ratio of the plasma pressure (p = n kB T) to the magnetic pressure (pmag = B²/2μ0). The term is commonly used in studies of the Sun and Earth's magnetic field, and in the field of fusion power designs. In the fusion power field, plasma is often confined using strong magnets. Since the temperature of the fuel scales with pressure, reactors attempt to reach the highest pressures possible. The costs of large magnets roughly scales like β½. Therefore, beta can be thought of as a ratio of money out to money in for a reactor, and beta can be thought of (very approximately) as an economic indicator of reactor efficiency. For tokamaks, betas of larger than 0.05 or 5% are desired for economically viable electrical production. The same term is also used when discussing the interactions of the solar wind with various magnetic fields. For example, beta in the corona of the Sun is about 0.01.
  • 398
  • 08 Oct 2022
Topic Review
Cygnus
Cygnus, known as the Swan, is a prominent constellation in the northern celestial hemisphere. Its distinctive shape resembles a flying bird with outstretched wings, earning it the nickname "the Northern Cross." Cygnus is rich in celestial wonders, including the famous binary star system Albireo, the North America Nebula, and the Veil Nebula complex.
  • 397
  • 08 Mar 2024
Biography
Watt W. Webb
Watt W. Webb is known for his co-invention (with Winfried Denk and Jim Strickler) of Multiphoton microscopy in 1990. Professor Watt W. Webb’s undergraduate studies at MIT in Business and Engineering Administration for his SB degree in 1947 led him to engineering research and development at Union Carbide Corporation Research Laboratories until 1952, then back to MIT for his ScD in Metallurgy
  • 395
  • 12 Dec 2022
Topic Review
Crux
Crux, commonly known as the Southern Cross, is a small but distinctive constellation located in the southern celestial hemisphere. Recognized for its iconic shape resembling a cross, Crux holds cultural significance across various civilizations and is one of the most recognizable asterisms in the night sky. Positioned close to the South Celestial Pole, Crux serves as a navigational aid for travelers in the southern hemisphere and has been used for centuries by sailors and explorers to determine directions.
  • 393
  • 08 Mar 2024
Topic Review
Application of Through Glass Via Technology
Glass has emerged as a highly versatile substrate for various sensor and MEMS (microelectromechanical systems) packaging applications, including electromechanical, thermal, optical, biomedical, and RF devices, due to its exceptional properties such as high geometrical tolerances, outstanding heat and chemical resistance, excellent high-frequency electrical properties, and the ability to be hermetically sealed. In these applications, Through Glass Via (TGV) technology plays a vital role in manufacturing and packaging by creating electrical interconnections through glass substrates.
  • 393
  • 18 Jan 2024
Topic Review
Osmium-162
Osmium (76Os) has seven naturally occurring isotopes, five of which are stable: 187Os, 188Os, 189Os, 190Os, and (most abundant) 192Os. The other natural isotopes, 184Os, and 186Os, have extremely long half-life (1.12×1013 years and 2×1015 years, respectively) and for practical purposes can be considered to be stable as well. 187Os is the daughter of 187Re (half-life 4.56×1010 years) and is most often measured in an 187Os/188Os ratio. This ratio, as well as the 187Re/188Os ratio, have been used extensively in dating terrestrial as well as meteoric rocks. It has also been used to measure the intensity of continental weathering over geologic time and to fix minimum ages for stabilization of the mantle roots of continental cratons. However, the most notable application of Os in dating has been in conjunction with iridium, to analyze the layer of shocked quartz along the Cretaceous–Paleogene boundary that marks the extinction of the dinosaurs 66 million years ago. There are also 30 artificial radioisotopes, the longest-lived of which is 194Os with a half-life of six years; all others have half-lives under 94 days. There are also nine known nuclear isomers, the longest-lived of which is 191mOs with a half-life of 13.10 hours. All isotopes and nuclear isomers of osmium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.
  • 393
  • 20 Oct 2022
Topic Review
Methods for Improving Thermal Fatigue Resistance of Copper
Thermal fatigue is the fatigue failure phenomenon caused by the thermal stress (or thermal strain) cycle caused by the temperature gradient cycle. 
  • 393
  • 11 May 2023
Topic Review
Radio-Mode Feedback in Galaxies
The Active Galactic Nuclei (AGN) population can be represented by two main categories. In the first category, Quasars and Seyfert galaxies, sources of high bolometric luminosities, capable of generating winds through radiation pressure due to its accretion rate close to Eddington, usually found in wide angle outflows, are commonly distinguished as radiative-mode (or sometimes also called as quasar-mode) AGN. In the second category, the so called radio-mode AGN (or jet-mode, or kinetic-mode), the central engine launches powerful collimated jets of relativistic particles accelerated in the inner regions of the accretion disk due to its intense magnetic fields. The origin of the difference between these two categories is believed to happen within the accretion disk structure and internal thermodynamics, and the resulting mass accretion rates.
  • 391
  • 28 Jun 2023
Topic Review
Corona Borealis
Corona Borealis, Latin for "Northern Crown," is a constellation in the northern celestial hemisphere, known for its distinctive semicircular shape resembling a crown. Its counterpart in the southern hemisphere, Corona Australis, shares a similar name and mythological association with crowns but lies on the opposite side of the celestial sphere. 
  • 391
  • 08 Mar 2024
Topic Review
Advanced Telescope for High Energy Astrophysics
Advanced Telescope for High-ENergy Astrophysics (Athena) is an X-ray observatory mission selected by European Space Agency (ESA) within its Cosmic Vision program to address the Hot and Energetic Universe scientific theme. Athena will operate in the energy range of 0.2–12 keV and will offer spectroscopic and imaging capabilities exceeding those of currently operating X-ray astronomy satellites – e.g. the Chandra X-ray Observatory and XMM-Newton – by at least one order of magnitude on several parameter spaces simultaneously.
  • 390
  • 30 Sep 2022
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