Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Kounotori Integrated Tether Experiment
Kounotori 6 (こうのとり6号機), also known as HTV-6, is the sixth flight of the H-II Transfer Vehicle, an uncrewed cargo spacecraft launched to resupply the International Space Station. It was launched at 13:26:47 UTC on 9 December 2016 aboard H-IIB launch vehicle from Tanegashima Space Center.
  • 490
  • 27 Oct 2022
Topic Review
Weak Interaction
In nuclear physics and particle physics, the weak interaction, which is also often called the weak force or weak nuclear force, is one of the four known fundamental interactions, with the others being electromagnetism, the strong interaction, and gravitation. It is the mechanism of interaction between subatomic particles that is responsible for the radioactive decay of atoms. The weak interaction participates in nuclear fission, and the theory describing its behaviour and effects is sometimes called quantum flavourdynamics (QFD). However, the term QFD is rarely used, because the weak force is better understood by electroweak theory (EWT). The effective range of the weak force is limited to subatomic distances, and is less than the diameter of a proton.
  • 3.1K
  • 27 Oct 2022
Topic Review
The Hum
The Hum is a phenomenon, or collection of phenomena, involving widespread reports of a persistent and invasive low-frequency humming, rumbling, or droning noise not audible to all people. Hums have been widely reported by national media in the UK and the United States. The Hum is sometimes prefixed with the name of a locality where the problem has been particularly publicized: e.g., the "Bristol Hum" or the "Taos Hum". It is unclear whether it is a single phenomenon; different causes have been attributed. In some cases, it may be a manifestation of tinnitus.
  • 1.3K
  • 27 Oct 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'.
  • 343
  • 27 Oct 2022
Topic Review
Music Without Sound
Music without sound can refer to music that falls outside the range of human hearing (typically 20 Hz–20 kHz) or to compositions, such as visual music, that are analogous to or suggestive of conventional music but in media other than sound, such as color, shape, position, motion and literature (see Discursive music below). It is commonly taken for granted that music is wont to be performed or recorded, but some sound works simply won't fit on a disc or on stage, being either extremely discreet (like Robin Minard's Silent Music) or incomplete (Varèse's Unfinished music). Additionally, silence can be regarded as the via negativa of music and has induced long lasting fascination to music composers of all kinds. A composer deals with the absence of sound as much as they deal with sounds. Therefore, this article includes several examples of apophasis in music (like Algorithmic music or Gesture Music).
  • 589
  • 27 Oct 2022
Topic Review
EnVision (Spacecraft)
EnVision is a proposed orbital mission to Venus that would perform high-resolution radar mapping and atmospheric studies. The mission would help scientists understand the relationships between its geological activity and the atmosphere, and it would investigate why Venus and Earth took such different evolutionary paths. The mission is studied by ESA in collaboration with NASA, with the potential sharing of responsibilities currently under assessment.
  • 312
  • 27 Oct 2022
Topic Review
Emergency Position-Indicating Radiobeacon Station
An emergency position-indicating radiobeacon (EPIRB) is a type of emergency locator beacon, a portable battery powered radio transmitter used in emergencies to locate airplanes, vessels, and persons in distress and in need of immediate rescue. In the event of an emergency, such as the ship sinking or an airplane crash, the transmitter is activated and begins transmitting a continuous radio signal which is used by search and rescue teams to quickly locate the emergency and render aid. The signal is detected by satellites operated by an international consortium of rescue services, COSPAS-SARSAT. The basic purpose of this system is to help rescuers find survivors within the so-called "golden day" (the first 24 hours following a traumatic event) during which the majority of survivors can usually be saved. The feature distinguishing modern EPIRBs, often called GPIRBs, from other types of emergency beacon is that it contains a GPS receiver and broadcasts its position, usually accurate within 100 metres (330 ft), to facilitate location. The standard frequency of a modern EPIRB is 406 MHz. It is an internationally regulated mobile radiocommunication service that aids search and rescue operations to detect and locate distressed boats, aircraft, and people. It is distinct from a Satellite emergency position-indicating radiobeacon station. The first form of these beacons was the 121.500 MHz ELT, which was designed as an automatic locator beacon for crashed military aircraft. These beacons were first used in the 1950s by the U.S. military and were mandated for use on many types of commercial and general aviation aircraft beginning in the early 1970s. The frequency and signal format used by the ELT beacons was not designed for satellite detection, which resulted in a system with poor location detection abilities and with long delays in detection of activated beacons. The satellite detection network was built after the ELT beacons were already in general use, with the first satellite not being launched until 1982, and even then, the satellites only provided detection, with location accuracy being roughly 20 kilometres (12 mi). The technology was later expanded to cover use on vessels at sea (EPIRB), individual persons (PLB and, starting in 2016, MSLD). All have migrated from using 121.500 MHz as their primary frequency to using 406 MHz, which was designed for satellite detection and location. Since the inception of Cospas-Sarsat in 1982, distress radiobeacons have assisted in the rescue of over 28,000 people in more than 7,000 distress situations. In 2010 alone, the system provided information used to rescue 2,388 persons in 641 distress situations.
  • 1.5K
  • 27 Oct 2022
Topic Review
Bow Shocks in Astrophysics
Bow shocks form the boundary between a magnetosphere and an ambient (or at least surrounding) magnetized medium. This occurs when the magnetic field of an astrophysical object interacts with the nearby flowing ambient plasma. For example, when the solar wind, flowing with a relative speed of order 400 km/s, encounters the magnetic field of Earth, a bow shape boundary forms. For Earth and other magnetized planets, it is the boundary at which the speed of the stellar wind abruptly drops as a result of its approach to the magnetopause. For stars, this boundary is typically the edge of the astrosphere, where the stellar wind meets the interstellar medium.
  • 1.6K
  • 27 Oct 2022
Topic Review
The Feynman Lectures on Physics
The Feynman Lectures on Physics is a physics textbook based on some lectures by Richard P. Feynman, a Nobel laureate who has sometimes been called "The Great Explainer". The lectures were presented before undergraduate students at the California Institute of Technology (Caltech), during 1961–1963. The book's co-authors are Feynman, Robert B. Leighton, and Matthew Sands. The Feynman Lectures on Physics is perhaps the most popular physics book ever written. More than 1.5 million English-language copies have been sold; probably even more copies have been sold in a dozen foreign-language editions. A 2013 review in Nature described the book as having "simplicity, beauty, unity ... presented with enthusiasm and insight".
  • 1.0K
  • 27 Oct 2022
Topic Review
Electricity Meter
thumb|North American domestic analogue electricity meter. thumb|Electricity meter with transparent plastic case (Israel) thumb|North American domestic electronic electricity meter An electricity meter, electric meter, electrical meter, or energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device. Electric utilities use electric meters installed at customers' premises for billing and monitoring purposes. They are typically calibrated in billing units, the most common one being the kilowatt hour (kWh). They are usually read once each billing period. When energy savings during certain periods are desired, some meters may measure demand, the maximum use of power in some interval. "Time of day" metering allows electric rates to be changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for demand response load shedding during peak load periods.
  • 708
  • 27 Oct 2022
  • Page
  • of
  • 118
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
Video Production Service
Feedback