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Hematocrit-Shear rate relations-Elevated Generally at both sea levels and high altitudes, hematocrit levels rise as children mature. These health-related causes and impacts of elevated hematocrit levels have been reported: Fall in blood plasma levels Dehydration Administering of testosterone supplement therapy In cases... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-Polycythemia vera (PV), a myeloproliferative disorder in which the bone marrow produces excessive numbers of red cells, is associated with elevated hematocrit.
Chronic obstructive pulmonary disease (COPD) and other pulmonary conditions associated with hypoxia may elicit an increased prod... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-Professional athletes' hematocrit levels are measured as part of tests for blood doping or erythropoietin (EPO) use; the level of hematocrit in a blood sample is compared with the long-term level for that athlete (to allow for individual variations in hematocrit level), and against an ab... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-Anabolic androgenic steroid (AAS) use can also increase the amount of RBCs and, therefore, impact the hematocrit, in particular the compounds boldenone and oxymetholone.
Capillary leak syndrome also leads to abnormally high hematocrit counts, because of the episodic leakage of plasma out... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-At higher altitudes, there is a lower oxygen supply in the air and thus hematocrit levels may increase over time.Hematocrit levels were also reported to be correlated with social factors that influence subjects. In the 1966–80 Health Examination Survey, there was a small rise in mean hem... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-Lowered Lowered hematocrit levels also pose health impacts. These causes and impacts have been reported: A low hematocrit level is a sign of a low red blood cell count. One way to increase the ability of oxygen transport in red blood cells is through blood transfusion, which is carried o... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-A low hematocrit with a low mean corpuscular volume (MCV) with a high red cell distribution width (RDW) suggests a chronic iron-deficient anemia resulting in abnormal hemoglobin synthesis during erythropoiesis. The MCV and the RDW can be quite helpful in evaluating a lower-than-normal he... | milkshake721/2.1M-wiki-STEM |
Hematocrit-Shear rate relations-Decreased hematocrit levels could indicate life-threatening diseases such as leukemia. When the bone marrow no longer produces normal red blood cells, hematocrit levels deviate from normal as well and thus can possibly be used in detecting acute myeloid leukemia. It can also be related t... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-Kinetic energy penetrator-A kinetic energy penetrator (KEP), also known as long-rod penetrator (LRP), is a type of ammunition designed to penetrate vehicle armour using a flechette-like, high-sectional density projectile. Like a bullet or kinetic energy weapon, this type of ammunition does not... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-History-Early cannons fired kinetic energy ammunition, initially consisting of heavy balls of worked stone and later of dense metals. From the beginning, combining high muzzle energy with projectile weight and hardness have been the foremost factors in the design of such weapons. Similarly, th... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-History-The development of the modern KE penetrator combines two aspects of artillery design, high muzzle velocity and concentrated force. High muzzle velocity is achieved by using a projectile with a low mass and large base area in the gun barrel. Firing a small-diameter projectile wrapped in... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-History-Concentration of force into a smaller area was initially attained by replacing the single metal (usually steel) shot with a composite shot using two metals, a heavy core (based on tungsten) inside a lighter metal outer shell. These designs were known as armour-piercing composite rigid ... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-History-Between 1941 and 1943, the British combined the two techniques in the armour-piercing discarding sabot (APDS) round. The sabot replaced the outer metal shell of the APCR. While in the gun, the shot had a large base area to get maximum acceleration from the propelling charge but once ou... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-Design-The principle of the kinetic energy penetrator is that it uses its kinetic energy, which is a function of its mass and velocity, to force its way through armor. If the armor is defeated, the heat and spalling (particle spray) generated by the penetrator going through the armor, and the ... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-Design-minimizing the width, since if the projectile does not tumble, it will hit the target face first. As most modern projectiles have circular cross-sectional areas, their impact area will scale with the square of the radius r (the impact area being πr2 )The penetrator length plays a large... | milkshake721/2.1M-wiki-STEM |
Kinetic energy penetrator-Design-For monobloc penetrators made of a single material, a perforation formula devised by Wili Odermatt and W. Lanz can calculate the penetration depth of an APFSDS round.In 1982, an analytical investigation drawing from concepts of gas dynamics and experiments on target penetration led to t... | milkshake721/2.1M-wiki-STEM |
Ocean-V RNA motif-Ocean-V RNA motif-The Ocean-V RNA motif is a conserved RNA structure discovered using bioinformatics. Only a few Ocean-V RNA sequences have been detected, all in sequences derived from DNA that was extracted from uncultivated bacteria found in ocean water. As of 2010, no Ocean-V RNA has been detected ... | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Cyclophilin-Cyclophilins (CYPs) are a family of proteins named after their ability to bind to ciclosporin (cyclosporin A), an immunosuppressant which is usually used to suppress rejection after internal organ transplants. They are found in all domains of life. These proteins have peptidyl prolyl isomerase a... | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Cyclophilin-Cyclophilin A is a cytosolic and highly abundant protein. The protein belongs to a family of isozymes, including cyclophilins B and C, and natural killer cell cyclophilin-related protein. Major isoforms have been found within single cells, including inside the Endoplasmic reticulum, and some are... | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Mammalian cyclophilins-Human genes encoding proteins containing the cyclophilin domain include: PPIA, PPIB, PPIC, PPID, PPIE, PPIF, PPIG, PPIH PPIL1, PPIL2, PPIL3, PPIL4, PPIAL4, PPIL6 PPWD1 Cyclophilin A Cyclophilin A (CYPA) also known as peptidylprolyl isomerase A (PPIA), which is found in the cytosol, ha... | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Mammalian cyclophilins-Cyclophilin A is also known to be recruited by the Gag polyprotein during HIV-1 virus infection, and its incorporation into new virus particles is essential for HIV-1 infectivity. | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Mammalian cyclophilins-Cyclophilin D Cyclophilin D (PPIF, note that literature is confusing, the mitochondrial cyclophilin is encoded by the PPIF gene), which is located in the matrix of mitochondria, is only a modulatory, but may or may not be a structural component of the mitochondrial permeability transi... | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Mammalian cyclophilins-However, mitochondria obtained from the cysts of Artemia franciscana, do not exhibit the mitochondrial permeability transition pore | milkshake721/2.1M-wiki-STEM |
Cyclophilin-Clinical significance-Diseases Overexpression of Cyclophilin A has been linked to poor response to inflammatory diseases, the progression or metastasis of cancer, and aging.
Cyclophilins as drug targets Cyclophilin inhibitors, such as cyclosporin, are being developed to treat neurodegenerative diseases. Cyc... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Dedekind domain-In abstract algebra, a Dedekind domain or Dedekind ring, named after Richard Dedekind, is an integral domain in which every nonzero proper ideal factors into a product of prime ideals. It can be shown that such a factorization is then necessarily unique up to the order of the factors. Th... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Dedekind domain-A field is a commutative ring in which there are no nontrivial proper ideals, so that any field is a Dedekind domain, however in a rather vacuous way. Some authors add the requirement that a Dedekind domain not be a field. Many more authors state theorems for Dedekind domains with the im... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Dedekind domain-An immediate consequence of the definition is that every principal ideal domain (PID) is a Dedekind domain. In fact a Dedekind domain is a unique factorization domain (UFD) if and only if it is a PID. | milkshake721/2.1M-wiki-STEM |
Dedekind domain-The prehistory of Dedekind domains-In the 19th century it became a common technique to gain insight into integer solutions of polynomial equations using rings of algebraic numbers of higher degree. For instance, fix a positive integer m . In the attempt to determine which integers are represented by th... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-The prehistory of Dedekind domains-For a few small values of m and n these rings of algebraic integers are PIDs, and this can be seen as an explanation of the classical successes of Fermat ( m=1,n=4 ) and Euler ( m=2,3,n=3 ). By this time a procedure for determining whether the ring of all algebraic i... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-The prehistory of Dedekind domains-By the 20th century, algebraists and number theorists had come to realize that the condition of being a PID is rather delicate, whereas the condition of being a Dedekind domain is quite robust. For instance the ring of ordinary integers is a PID, but as seen above the ... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-The prehistory of Dedekind domains-Another illustration of the delicate/robust dichotomy is the fact that being a Dedekind domain is, among Noetherian domains, a local property: a Noetherian domain R is Dedekind iff for every maximal ideal M of R the localization RM is a Dedekind ring. But a local d... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Alternative definitions-For an integral domain R that is not a field, all of the following conditions are equivalent: (DD1) Every nonzero proper ideal factors into primes.
(DD2) R is Noetherian, and the localization at each maximal ideal is a discrete valuation ring.
(DD3) Every nonzero fractional ide... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Alternative definitions-(DD5) For any two ideals I and J in R , I is contained in J if and only if J divides I as ideals. That is, there exists an ideal H such that I=JH . A commutative ring (not necessarily a domain) with unity satisfying this condition is called a containment-division ring (C... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Alternative definitions-A Krull domain is a higher-dimensional analog of a Dedekind domain: a Dedekind domain that is not a field is a Krull domain of dimension 1. This notion can be used to study the various characterizations of a Dedekind domain. In fact, this is the definition of a Dedekind domain us... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Some examples of Dedekind domains-All principal ideal domains and therefore all discrete valuation rings are Dedekind domains. | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Some examples of Dedekind domains-The ring R=OK of algebraic integers in a number field K is Noetherian, integrally closed, and of dimension one: to see the last property, observe that for any nonzero prime ideal I of R, R/I is a finite set, and recall that a finite integral domain is a field; so by (D... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Some examples of Dedekind domains-The other class of Dedekind rings that is arguably of equal importance comes from geometry: let C be a nonsingular geometrically integral affine algebraic curve over a field k. Then the coordinate ring k[C] of regular functions on C is a Dedekind domain. This is largely... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Some examples of Dedekind domains-Both of these constructions can be viewed as special cases of the following basic result: Theorem: Let R be a Dedekind domain with fraction field K. Let L be a finite degree field extension of K and denote by S the integral closure of R in L. Then S is itself a Dedekind... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Some examples of Dedekind domains-Zariski and Samuel were sufficiently taken with this construction to ask whether every Dedekind domain arises from it; that is, by starting with a PID and taking the integral closure in a finite degree field extension. A surprisingly simple negative answer was given by ... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-Let R be an integral domain with fraction field K. A fractional ideal is a nonzero R-submodule I of K for which there exists a nonzero x in K such that xI⊂R.
Given two fractional ideals I and J, one defines their product IJ as the set of all finite sums ∑ninjn,in∈... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-One then tautologically has I∗I⊂R . In fact one has equality if and only if I, as an element of the monoid of Frac(R), is invertible. In other words, if I has any inverse, then the inverse must be I∗ A principal fractional ideal is one of the form xR for some non... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-A domain R is a PID if and only if every fractional ideal is principal. In this case, we have Frac(R) = Prin(R) = K×/R× , since two principal fractional ideals xR and yR are equal iff xy−1 is a unit in R. | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-For a general domain R, it is meaningful to take the quotient of the monoid Frac(R) of all fractional ideals by the submonoid Prin(R) of principal fractional ideals. However this quotient itself is generally only a monoid. In fact it is easy to see that the class of... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-Now we can appreciate (DD3): in a Dedekind domain (and only in a Dedekind domain) every fractional ideal is invertible. Thus these are precisely the class of domains for which Frac(R)/Prin(R) forms a group, the ideal class group Cl(R) of R. This group is trivial if ... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-We note that for an arbitrary domain one may define the Picard group Pic(R) as the group of invertible fractional ideals Inv(R) modulo the subgroup of principal fractional ideals. For a Dedekind domain this is of course the same as the ideal class group. However, on... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-A remarkable theorem of L. Claborn (Claborn 1966) asserts that for any abelian group G whatsoever, there exists a Dedekind domain R whose ideal class group is isomorphic to G. Later, C.R. Leedham-Green showed that such an R may be constructed as the integral closure... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Fractional ideals and the class group-In contrast, one of the basic theorems in algebraic number theory asserts that the class group of the ring of integers of a number field is finite; its cardinality is called the class number and it is an important and rather mysterious invariant, notwithstanding the... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-In view of the well known and exceedingly useful structure theorem for finitely generated modules over a principal ideal domain (PID), it is natural to ask for a corresponding theory for finitely generated modules over a Dedekind domain. | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-Let us briefly recall the structure theory in the case of a finitely generated module M over a PID R . We define the torsion submodule T to be the set of elements m of M such that rm=0 for some nonzero r in R . Then: (M1) T can be decomposed int... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-(M2) The torsion submodule is a direct summand. That is, there exists a complementary submodule P of M such that M=T⊕P (M3PID) P isomorphic to Rn for a uniquely determined non-negative integer n . In particular, P is a finitely generated free modu... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-Now let M be a finitely generated module over an arbitrary Dedekind domain R . Then (M1) and (M2) hold verbatim. However, it follows from (M3PID) that a finitely generated torsionfree module P over a PID is free. In particular, it asserts that all fra... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-Rank one projective modules can be identified with fractional ideals, and the last condition can be rephrased as [I1⋯Ir]=[J1⋯Js]∈Cl(R). | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-Thus a finitely generated torsionfree module of rank n>0 can be expressed as Rn−1⊕I , where I is a rank one projective module. The Steinitz class for P over R is the class [I] of I in Cl(R) : it is uniquely determined. A consequence of this is: T... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Finitely generated modules over a Dedekind domain-These results were established by Ernst Steinitz in 1912.
An additional consequence of this structure, which is not implicit in the preceding theorem, is that if the two projective modules over a Dedekind domain have the same class in the Grothendieck gr... | milkshake721/2.1M-wiki-STEM |
Dedekind domain-Locally Dedekind rings-There exist integral domains R that are locally but not globally Dedekind: the localization of R at each maximal ideal is a Dedekind ring (equivalently, a DVR) but R itself is not Dedekind. As mentioned above, such a ring cannot be Noetherian. It seems that the first examples o... | milkshake721/2.1M-wiki-STEM |
Explanatory journalism-Explanatory journalism-Explanatory journalism or explanatory reporting is a form of reporting that attempts to present ongoing news stories in a more accessible manner by providing greater context than would be presented in traditional news sources. The term is often associated with the explanato... | milkshake721/2.1M-wiki-STEM |
Explanatory journalism-Relation to analytic journalism-Journalism professor Michael Schudson says explanatory journalism and analytic journalism are the same, because both attempt to "explain a complicated event or process in a comprehensible narrative" and require "intelligence and a kind of pedagogical flair, linking... | milkshake721/2.1M-wiki-STEM |
Space tug-Space tug-A space tug is a type of spacecraft used to transfer spaceborne cargo from one orbit to another orbit with different energy characteristics. An example would be moving a spacecraft from a low Earth orbit (LEO) to a higher-energy orbit like a geostationary transfer orbit, a lunar transfer, or an esca... | milkshake721/2.1M-wiki-STEM |
Space tug-Background-The space tug was first envisioned in the post-World War II era as a support vehicle for a permanent, Earth-orbiting space station. It was used by science fiction writer Murray Leinster as the title of a novel published in 1953 as the sequel to Space Platform, another novel about such a space stati... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Space tugs can be roughly categorised into a few types: Large tugs that dock with satellites in orbit which may be able to perform services like refuelling or repairs or enhancements as well as changing the satellites orbit whether that is to extend life of satellite or to deorbit it.
Rock... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Large tugs that dock Mission Extension Vehicle In 2011 ViviSat a joint project between U.S. Space and ATK proposed the Mission Extension Vehicle. In 2016 ViviSat was dissolved when U.S. Space declared bankruptcy and ATK merged with Orbital Science Corporation to form Orbital ATK. In 2017 O... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Shijian-21 In December 2021 - January 2022, China's Shijian-21 space debris mitigation satellite has docked with the defunct Beidou-2 G2 navigation satellite to drastically alter its geostationary orbit, demonstrating capabilities only previously exhibited by the United States. | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Smaller tugs and dispensers SHERPA Spaceflight Inc. developed SHERPA, which builds upon the capabilities of the Spaceflight Secondary Payload System (SSPS) by incorporating propulsion and power generation subsystems, which creates a propulsive tug dedicated to maneuvering to an optimal orb... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-ION Satellite Carrier D-Orbit, an Italian space logistics and transportation company, developed the InOrbit NOW ION Satellite Carrier. The first launch occurred on 3 September 2020 on a Vega rocket, but subsequent launches have all been on SpaceX Falcon 9 Transporter missions. On January 3... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Long Duration Propulsive ESPA (LDPE) LDPE is based on a Northrop Grumman payload adapter used to help attach the upper stage to the main satellite in addition to hosting a few slots for other smallsats. However, the entire system is powered by the ESPAStar satellite bus, which is in charge... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Momentus Space Momentus Space develops different space tug versions focusing on large velocity changes over 1 km/s. Two demonstration missions of their Vigoride platform took place on 25 May 2022 and 3 January 2023 with key tests occurring through 2022. Momentus Space became widely known i... | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Epic Aerospace Epic Aerospace's Chimera LEO 1 launched on 3 January 2023. | milkshake721/2.1M-wiki-STEM |
Space tug-Existing space tugs-Launcher Reports surfaced circa June 15, 2021 of Launcher's Orbiter space tug. Launching on its own rocket as well as SpaceX’s Falcon 9 it provides 150 kilograms of payload, either 90 units of CubeSat or else larger satellites using standard smallsat separation systems. With a chemical pro... | milkshake721/2.1M-wiki-STEM |
Space tug-Early Concepts - NASA Space Transportation System-A reusable space tug was studied by NASA in the late 60s and early 70s as part of a reusable Space Transportation System (STS). This consisted of a basic propulsion module, to which a crew module or other payload could be attached. Optional legs could be added... | milkshake721/2.1M-wiki-STEM |
Space tug-Space Shuttle era-Expendable upper stages The Shuttle program filled the role of high-energy orbital transfer by the development of a solid-fueled single-stage Payload Assist Module and two-stage Inertial Upper Stage.A more powerful liquid hydrogen fueled Centaur-G stage was developed for use on the Shuttle, ... | milkshake721/2.1M-wiki-STEM |
Space tug-Space Shuttle era-Orbital Maneuvering Vehicle NASA studied another space tug design, termed the Orbital Maneuvering Vehicle (OMV), along with its plans for Space Station Freedom. The OMV's role would have been a reusable space vehicle that would retrieve satellites, such as Hubble, and bring them to Freedom f... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Parom The Russian RKK Energia corporation proposed a space tug named Parom in 2005 which could be used to ferry both the proposed Kliper crew vehicle or uncrewed cargo and fuel resupply modules to ISS. Keeping the tug in space would have allowed for a less massive Kliper, enabli... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-VASIMR The VASIMR electric plasma rocket could be used to power a high-efficiency space tug, using only 9 tons of Argon propellant to make a round trip to the Moon, delivering 34 tons of cargo from Low Earth Orbit to low lunar orbit. As of 2014, Ad Astra Rocket Company had put f... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-ISRO PAM-G Indian Space Research Organisation has built an upper stage called PAM-G (Payload Assist Module for GSLV) capable of pushing payloads directly to MEO or GEO orbits from low Earth orbits. PAM-G is powered by hypergolic liquid motor with restart capability, derived from... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-PAM-G would form the fourth stage of GSLV Mk2C launch vehicle, sitting on top of GSLV's cryogenic third stage. | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Jupiter Lockheed Martin made a concept proposal to NASA in 2015 for a design called the Jupiter space tug, to be based on the designs of two earlier Lockheed Martin spacecraft—Mars Atmosphere and Volatile Evolution Mission and the Juno—as well as a robotic arm from MDA derived f... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-In the event, NASA did not agree to fund the Jupiter development, and Lockheed Martin is not developing the tug with private capital. | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Artemis Transfer Stages One of NASA's Artemis Program's proposed lunar landers is a partially reusable three stage design. One of its main elements is a transfer stage to move the lander from the Lunar Gateway's orbit to a low lunar orbit. Future versions should be able to retur... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Moon Cruiser Designed by Airbus, the Moon Cruiser is a conceptual lunar logistics vehicle based on the ATV and ESM that is proposed to be used to support the international Lunar Gateway. If funded, it would make up a part of ESA's contribution to the Lunar Gateway program. As of... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Skyrora Space Tug British launch vehicle manufacturer Skyrora shared details of their Space Tug in 2021, revealing it to be usable as the third stage of their Skyrora XL rocket. The company shared a video of the Space Tug undergoing a live test in January 2021. As well as being ... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-Exotrail SpaceVan Orbital Transfer Vehicle Exotrail unveils the April 12, 2022 of Orbital Transfer Vehicle, SpaceVan. The debut SpaceVan mission will launch on board a Falcon 9 rideshare mission in October 2023 following a launch service agreement signed between Exotrail and Spa... | milkshake721/2.1M-wiki-STEM |
Space tug-Twenty-first century proposals-ULA Common Centaur as a SpaceTug The Flexible Lunar Architecture for Exploration (FLARE) is a concept to deliver four crew to the lunar surface for a minimum of seven days and then return them safely to Earth. A key component of FLARE is the modified ULA Common Centaur used as a... | milkshake721/2.1M-wiki-STEM |
Space tug-Other sources-NASA Report, Technical Study for the Use of the Saturn 5, INT-21 and Other Saturn 5 Derivatives to Determine an Optimum Fourth Stage (space tug). Volume 1: Technical Volume, Book 1. | milkshake721/2.1M-wiki-STEM |
Pitting enamel hypoplasia-Pitting enamel hypoplasia-Enamel hypoplasia can take a variety of forms, but all types are associated with a reduction of enamel formation due to disruption in ameloblast production. One of the most common types, Pitting Enamel Hypoplasia (PEH), ranges from small circular pinpricks to larger i... | milkshake721/2.1M-wiki-STEM |
Pitting enamel hypoplasia-Pitting enamel hypoplasia-It is not always clear why PEH forms instead of other hypoplasia types, particularly linear enamel hypoplasia. However, the position on the crown, the tooth type and the cause of the disruption are all likely contributing factors. It has been suggested that because it... | milkshake721/2.1M-wiki-STEM |
Bushman poison-Bushman poison-Bushman poison can refer to a number of plants or insects used as ingredients by the San people when preparing arrow poisons: Toxicodendron species of the Western Cape province Bushman's poison, Acokanthera spectabilis Bushman's poison, Acokanthera oblongifolia Bushman's poison, Acokanther... | milkshake721/2.1M-wiki-STEM |
Julian Togelius-Julian Togelius-Julian Togelius is an associate professor at the Department of Computer Science and Engineering at the New York University Tandon School of Engineering. | milkshake721/2.1M-wiki-STEM |
Julian Togelius-Career-Togelius holds a BA from Lund University, an MSc from the University of Sussex, and a PhD from the University of Essex.He was an associate professor at the Center for Computer Games Research, IT University of Copenhagen before moving to NYU.Togelius is the editor in chief of the IEEE Transactions... | milkshake721/2.1M-wiki-STEM |
Julian Togelius-Research-Togelius was described by Kenneth O. Stanley as one of "the world's most accomplished experts at the intersection of games and AI". His research has appeared in media such as New Scientist, and Le Monde, The Verge, The Economist, and the MIT Technology Review. | milkshake721/2.1M-wiki-STEM |
Casimir element-Casimir element-In mathematics, a Casimir element (also known as a Casimir invariant or Casimir operator) is a distinguished element of the center of the universal enveloping algebra of a Lie algebra. A prototypical example is the squared angular momentum operator, which is a Casimir element of the thre... | milkshake721/2.1M-wiki-STEM |
Casimir element-Definition-The most commonly-used Casimir invariant is the quadratic invariant. It is the simplest to define, and so is given first. However, one may also have Casimir invariants of higher order, which correspond to homogeneous symmetric polynomials of higher order. | milkshake721/2.1M-wiki-STEM |
Casimir element-Definition-Quadratic Casimir element Suppose that g is an n -dimensional Lie algebra. Let B be a nondegenerate bilinear form on g that is invariant under the adjoint action of g on itself, meaning that ad ad XZ)=0 for all X, Y, Z in g . (The most typical choice of B is the Killing form if g is s... | milkshake721/2.1M-wiki-STEM |
Casimir element-Definition-Although the definition relies on a choice of basis for the Lie algebra, it is easy to show that Ω is independent of this choice. On the other hand, Ω does depend on the bilinear form B. The invariance of B implies that the Casimir element commutes with all elements of the Lie algebra g , an... | milkshake721/2.1M-wiki-STEM |
Casimir element-Definition-A specific form of this construction plays an important role in differential geometry and global analysis. Suppose that a connected Lie group G with Lie algebra g acts on a differentiable manifold M. Consider the corresponding representation ρ of G on the space of smooth functions on M. Then... | milkshake721/2.1M-wiki-STEM |
Casimir element-Definition-Specializing further, if it happens that M has a Riemannian metric on which G acts transitively by isometries, and the stabilizer subgroup Gx of a point acts irreducibly on the tangent space of M at x, then the Casimir invariant of ρ is a scalar multiple of the Laplacian operator coming from ... | milkshake721/2.1M-wiki-STEM |
Casimir element-Properties-Uniqueness of the quadratic Casimir element Since for a simple Lie algebra every invariant bilinear form is a multiple of the Killing form, the corresponding Casimir element is uniquely defined up to a constant. For a general semisimple Lie algebra, the space of invariant bilinear forms has o... | milkshake721/2.1M-wiki-STEM |
Casimir element-Properties-Relation to the Laplacian on G If G is a Lie group with Lie algebra g , the choice of a nondegenerate invariant bilinear form on g corresponds to a choice of bi-invariant Riemannian metric on G . Then under the identification of the universal enveloping algebra of g with the left invaria... | milkshake721/2.1M-wiki-STEM |
Casimir element-Properties-Casimir elements and representation theory By Racah's theorem, for a semisimple Lie algebra the dimension of the center of the universal enveloping algebra is equal to its rank. The Casimir operator gives the concept of the Laplacian on a general semisimple Lie group; but there is no unique a... | milkshake721/2.1M-wiki-STEM |
Casimir element-Properties-By definition any member of the center of the universal enveloping algebra commutes with all other elements in the algebra. By Schur's Lemma, in any irreducible representation of the Lie algebra, any Casimir element is thus proportional to the identity. The eigenvalues of all Casimir elements... | milkshake721/2.1M-wiki-STEM |
Casimir element-Properties-Let L(λ) be the finite dimensional highest weight module of weight λ . Then the quadratic Casimir element Ω acts on L(λ) by the constant ⟨λ,λ+2ρ⟩=⟨λ+ρ,λ+ρ⟩−⟨ρ,ρ⟩, where ρ is the weight defined by half the sum of the positive roots. If L(λ) is nontrivial (i.e. if λ≠0 ), then this cons... | milkshake721/2.1M-wiki-STEM |
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