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Topic Review
Plasma Modeling and Prebiotic Chemistry
The plasma kinetics involves elementary processes by which free electrons ultimately activate weakly reactive molecules, such as carbon dioxide or methane, thereby potentially starting prebiotic reaction chains. These processes include electron–molecule reactions and energy exchanges between molecules. They are basic processes, for example, in the famous Miller-Urey experiment, and become relevant in any prebiotic scenario where the primordial atmosphere is significantly ionized by electrical activity, photoionization or meteor phenomena. The kinetics of plasma displays remarkable complexity due to the non-equilibrium features of the energy distributions involved.
  • 620
  • 18 Mar 2022
Topic Review
Plasma Medicine
Plasma medicine is an emerging field that combines plasma physics, life sciences and clinical medicine. It is being studied in disinfection, healing, and cancer. Most of the research is in vitro and in animal models. It uses ionized gas (physical plasma) for medical uses or dental applications. Plasma, often called the fourth state of matter, is an ionized gas containing positive ions and negative ions or electrons, but is approximately charge neutral on the whole. The plasma sources used for plasma medicine are generally low temperature plasmas, and they generate ions, chemically reactive atoms and molecules, and UV-photons. These plasma-generated active species are useful for several bio-medical applications such as sterilization of implants and surgical instruments as well as modifying biomaterial surface properties. Sensitive applications of plasma, like subjecting human body or internal organs to plasma treatment for medical purposes, are also possible. This possibility is being heavily investigated by research groups worldwide under the highly-interdisciplinary research field called 'plasma medicine'.
  • 340
  • 27 Oct 2022
Topic Review
Plasma
Plasma (from grc πλάσμα (plásma) 'moldable substance') is one of the four fundamental states of matter. It contains a significant portion of charged particles – ions and/or electrons. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. It extends to the rarefied intracluster medium and possibly to intergalactic regions. Plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field. The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching. Depending on temperature and density, a certain amount of neutral particles may also be present, in which case plasma is called partially ionized. Neon signs and lightning are examples of partially ionized plasmas. Unlike the phase transitions between the other three states of matter, the transition to plasma is not well defined and is a matter of interpretation and context. Whether a given degree of ionization suffices to call a substance 'plasma' depends on the specific phenomenon being considered.
  • 2.7K
  • 25 Nov 2022
Topic Review
Planetary Radar
Planetary radar observations have provided invaluable information on the solar system through both ground-based and space-based observations. The radar technology is a remote-sensing method for planetary exploration and the methods to interpret the radar data have advanced in the eight decades of increasing use, where the field stands in the early 2020s, and what are the future prospects of the ground-based facilities conducting planetary radar observations and the planned spacecraft missions equipped with radar instruments. 
  • 304
  • 11 Dec 2023
Topic Review
Planetary Geology
Planetary geology, alternatively known as astrogeology or exogeology, is a planetary science discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites. Although the geo- prefix typically indicates topics of or relating to Earth, planetary geology is named as such for historical and convenience reasons; due to the types of investigations involved, it is closely linked with Earth-based geology. These investigations are centered around the composition, structure, processes, and history of a planet. Planetary geology includes such topics as determining the internal structure of the terrestrial planets, and also looks at planetary volcanism and surface processes such as impact craters, fluvial and aeolian processes. The structures and compositions of the giant planets and their moons are also examined, as is the make-up of the minor bodies of the Solar System, such as asteroids, the Kuiper Belt, and comets. Planetary geology includes applications derived from other closely related fields within in the geological sciences, such as geophysics and geochemistry.
  • 679
  • 18 Oct 2022
Topic Review
Planet-Hosting Stars
Planet-hosting stars are stars which host planets, therefore forming planetary systems. This article describes the correlations between stars' characteristics and the characteristics of the planets that orbit them, and other connections between stars and their planets.
  • 1.4K
  • 23 Nov 2022
Topic Review
PIXE and XRF in Heritage Science
Analytical techniques play a fundamental role in heritage science (HS). Among them, Particle Induced X-ray Emission (PIXE) and X-ray Fluorescence (XRF) techniques are widely used in many laboratories for elemental composition analysis. Although they are well-established, a strong effort is put on their upgrade, making them suitable for more and more applications. 
  • 795
  • 11 Jul 2022
Topic Review
Pisces
Pisces, the Latin term for "fishes," is a sprawling constellation in the northern celestial hemisphere, representing two fish tied together by a cord. Positioned between Aquarius and Aries along the ecliptic, Pisces is rich in mythology and serves as a prominent fixture in both ancient and modern astronomy.
  • 277
  • 15 Mar 2024
Topic Review
Piezoelectric Transducers Energy Conversion Network
Conversion between mechanical energy and electrical energy is critically important in industrial applications. Piezoelectric materials are unique for their ability in electric–mechanical transduction by applications of piezoelectric transducers that are usually spherical, cylindrical, or schistose. This topic review presents the most recent development of a piezoelectric transducers energy conversion network.
  • 1.8K
  • 31 Oct 2020
Topic Review
Pictor
Pictor, a relatively faint constellation in the southern celestial hemisphere, is named after the easel used by artists to hold their canvases. It is located between the star Canopus and the Large Magellanic Cloud.
  • 238
  • 15 Mar 2024
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