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76,403,602 | https://en.wikipedia.org/wiki/Kristallografija | Kristallografija, also transliterated as Kristallografiya or Kristallografiia, () is a bimonthly, peer-reviewed, Russian crystallography journal currently published by MAIC "Science/Interperiodica". An English translation Crystallography Reports is published by Pleiades Publishing, Inc.
History
The journal was founded in 1956 by Alexei Vasilievich Shubnikov and was initially dedicated to the publication of research from the Institute of Crystallography of the Russian Academy of Sciences.
The journal is also available in English translation as Soviet Physics Crystallography (ISSN 0038-5638) 1956–1992 (volumes 1–37) continued as Crystallography Reports (ISSN 1063-7745) 1993–present (volumes 38–present). The journal is available in online format (ISSN 1562-689X) from 2000–present. The current publisher of the translated journal is Pleiades Publishing, Inc., and the distributor is Springer Nature.
The journal was the first to publish papers in the new areas of antisymmetry, polychromatic symmetry, and generalized symmetry.
Scope
The journal publishes original articles, short communications, and reviews on various aspects of crystallography: crystallographic symmetry; theory of crystalline structures; diffraction and scattering of X-rays, electrons, and neutrons, determination of crystal structure of inorganic and organic substances, including proteins and other biological substances; UV–Vis and IR spectroscopy; growth, imperfect structure and physical properties of crystals; thin films, liquid crystals, nanomaterials and ceramics, partially disordered systems, crystallographic methods; instruments and equipment; crystallographic software; history of crystallography; anniversaries; and obituaries.
Editors
A.V. Shubnikov (1956–1968)
N.V. Belov (1968–1982)
B.K. Vainshtein (1982–1996)
L.A. Shuvalov (1997–2004)
M.V. Kovalchuk (since 2004)
Abstracting and indexing
Crystallography Reports is abstracted and indexed by the following services.
Astrophysics Data System (ADS)
Baidu
CLOCKSS
CNKI
CNPIEC (China National Publications Import Export Corporation)
Chemical Abstracts Service (CAS)
Current Contents Physical, Chemical and Earth Sciences
Dimensions
EBSCO
EI Compendex
FIZ Karlsruhe
Google Scholar
INIS Atomindex
INSPEC
Japanese Science and Technology Agency (JST)
Journal Citation Reports/Science Edition
Naver
OCLC WorldCat Discovery Service
Portico
ProQuest-ExLibris Primo / Summon
Reaction Citation Index
SCImago
SCOPUS
Science Citation Index Expanded (SCIE)
TD Net Discovery Service
UGC-CARE List (India)
Wanfang
References
Crystallography journals
Russian-language journals
Academic journals established in 1956
Bimonthly journals | Kristallografija | [
"Chemistry",
"Materials_science"
] | 590 | [
"Crystallography journals",
"Crystallography"
] |
76,403,716 | https://en.wikipedia.org/wiki/Cortinarius%20lacustris | Cortinarius lacustris is an inedible species of mushroom-forming fungus belonging to the family Cortinariaceae and found mainly in oak groves in deciduous forests.
Description
The mushroom cap is a reddish, cinnamon brown with a diameter between . It has a cylindrical stipe that turns to a purple-black when reacting to potassium hydroxide solution exposure. The partial veil has a slight yellow colour. The ellipsoid spores measure between 8.5–11 μm by 5–6 μm.
See also
List of Cortinarius species
References
lacustris
Fungus species
Fungi described in 1997
Fungi of Europe | Cortinarius lacustris | [
"Biology"
] | 128 | [
"Fungi",
"Fungus species"
] |
76,403,842 | https://en.wikipedia.org/wiki/Fish%20Head%20Nebula | The Fish Head Nebula, or the Northern Bear Nebula, is part of a large star forming system of gas and dust located along the Perseus spiral arm of the Milky Way. The nebula is located in the Constellation Cassiopeia, approximately 6,000 light-years from Earth and is adjacent to the much larger Heart Nebula. The brighter region of the nebula is designated NGC 896 and is the home to many young and large stars. These stars radiate high amounts of ultraviolet light. This UV radiation excites the surrounding gas and causes it to shine at a high brightness. This mapping is known as false color and is common with many of the Hubble Space Images.
Gallery
See also
Heart Nebula, another nebula nearby
Nebula
Astrophotography
References
Milky Way
Emission nebulae
Cassiopeia (constellation) | Fish Head Nebula | [
"Astronomy"
] | 167 | [
"Cassiopeia (constellation)",
"Constellations"
] |
76,404,147 | https://en.wikipedia.org/wiki/Zirconium%20iodate | Zirconium iodate is an inorganic compound with the chemical formula Zr(IO3)4. It can be prepared by reacting sodium iodate and zirconium sulfate tetrahydrate in an aqueous solution. The resulting precipitate is dried and refluxed in concentrated nitric acid. Zirconium iodate trihydrate can be obtained by reacting hydrated zirconium oxide and iodine pentoxide (1.4~3.3% concentration) in water. Its basic salt Zr(OH)n(IO3)4−n is known.
References
Zirconium compounds
Iodates | Zirconium iodate | [
"Chemistry"
] | 138 | [
"Iodates",
"Oxidizing agents"
] |
76,404,216 | https://en.wikipedia.org/wiki/Bismuth%20iodate | Bismuth iodate is an inorganic compound with the chemical formula Bi(IO3)3. Its anhydrate can be obtained by reacting bismuth nitrate and iodic acid, dissolving the resulting precipitate in 7.8 mol/L nitric acid, and heating to volatilize and crystallize at 70 °C; The dihydrate can be obtained by reacting bismuth nitrate and potassium iodate or sodium iodate. It is obtained by evaporation and crystallization in 7 mol/L nitric acid at 50 °C. Its basic salt BiOIO3 is known.
References
Bismuth compounds
Iodates | Bismuth iodate | [
"Chemistry"
] | 139 | [
"Iodates",
"Inorganic compounds",
"Oxidizing agents",
"Inorganic compound stubs"
] |
76,404,260 | https://en.wikipedia.org/wiki/Tin%28IV%29%20iodate | Tin(IV) iodate is an inorganic compound with the chemical formula Sn(IO3)4. It was first obtained in 2020 through the hydrothermal reaction of tin(II) oxide and iodic acid in water at 220 °C. It is a colorless columnar crystal, crystallized in the triclinic P space group. It has an indirect band gap (experimental 4.0 eV; calculated 2.75 eV).
References
Tin compounds
Iodates
Substances discovered in the 2020s | Tin(IV) iodate | [
"Chemistry"
] | 103 | [
"Iodates",
"Inorganic compounds",
"Oxidizing agents",
"Inorganic compound stubs"
] |
76,404,281 | https://en.wikipedia.org/wiki/Vase%20%28heraldry%29 | A vase () is a heraldic symbol that has been used by the Swedish and Polish-Lithuanian House of Vasa. It has been used as a symbol of the Swedish state even after the extinction of the Vasa lineage, and was reused in 1818 as part of the coat of arms of Sweden. The vase has been used by other families, both noble and common, and is still in use by the government-owned real estate enterprise Vasakronan.
The term originally referred to a bundle of twigs or branches and comes from the Old Swedish vasi and is related to vad ("seine").The term has been used in compounds such as risvase (a bundle of straw of twigs used to attract fish near shore) and stormvase ("fascine"). As a coat of arms the term vase has likely been used since the symbol has mostly resembled a fascine.
The exact meaning of the heraldic symbol of the Vasa family has been debated among both historians and heralds. During the late 16th century, the vase was depicted to look more like a sheaf, while medieval depictions show a sort of bundle, and which possibly could have been a depiction of a type of anchor plate. In modern times, depictions of a vase as a sheaf are considered inaccurate. Due to its historical association with a sheaf, it has sometimes been called vasakärven, "the Vasa sheaf".
The vase was used as a nationalist symbol during the 1930s and 1940s, especially by fascist and nazist groups in Sweden, such as the Swedish National Socialist Workers' Party (Svensk socialistisk samling) under Sven Olov Lindholm (1903–1998). The vase was also used as a party symbol by National Socialist Front which was active about 1984–2008. It was also used by democratic political organizations like Svenska Landsbygdens Kvinnoförbund, today Centerkvinnorna, the women's organization of the Centre Party.
Notes
Symbols
Heraldry | Vase (heraldry) | [
"Mathematics"
] | 415 | [
"Symbols"
] |
76,404,335 | https://en.wikipedia.org/wiki/Plutonium%28IV%29%20iodate | Plutonium(IV) iodate is an inorganic compound with the chemical formula Pu(IO3)4, it is a salt which decomposes into plutonium(IV) oxide above 540 °C. It can be generated in the reaction of plutonium(IV) nitrate and iodic acid, but this method cannot obtain a pure product; Another preparation method is the reaction of plutonium(IV) nitrate or plutonium(IV) chloride with potassium iodate and dilute nitric acid. It can crystallize in the tetragonal crystal system with space group P42/n.
References
Plutonium compounds
Iodates | Plutonium(IV) iodate | [
"Chemistry"
] | 128 | [
"Iodates",
"Inorganic compounds",
"Oxidizing agents",
"Inorganic compound stubs"
] |
76,404,400 | https://en.wikipedia.org/wiki/RCW%2042 | RCW 42 (or Gum 26), is a giant H II region in the Milky Way.
It contains DBS2003 38, a deeply embedded infrared cluster.
It lies at the western edge of the immense galactic chimney GSH 277+00+36. Not much research has been done on RCW 42, which is unusual, given that its status as a giant H II region suggests that it is one of the greatest and largest regions of star formation in the Milky Way.
References
Milky Way
Emission nebulae
Gum Nebula
H II regions
Vela (constellation) | RCW 42 | [
"Astronomy"
] | 115 | [
"Vela (constellation)",
"Constellations"
] |
76,404,451 | https://en.wikipedia.org/wiki/Bovista%20tomentosa | Bovista tomentosa is a species of puffball fungus in the family Lycoperdaceae, first described by Carlo Vittadini and given its current name by Giovanni Battista de Toni.
Distribution and habitat
It appears in North America, Europe, Africa and Asia, most often in Europe. It usually grows outside forests, in sunny places, among xerothermic vegetation, on calcareous soils among grasses, on pastures, sometimes on rocks, less often in pine forests, parks and gardens, also in Juniperus communis thickets, on abandoned farmlands and industrial waste.
References
External links
Lycoperdaceae
Puffballs
Fungi described in 1888
Fungus species | Bovista tomentosa | [
"Biology"
] | 138 | [
"Fungi",
"Fungus species"
] |
76,404,536 | https://en.wikipedia.org/wiki/Colacogloea%20peniophorae | Colacogloea peniophorae is a species of fungus in the family Colacogloeaceae, first described by Bourdot & Galzin and given its current name by Franz Oberwinkler, Robert Bauer and Robert Joseph Bandoni.
Distribution and habitat
It appears in North America, Europe and Asia, most often in Europe. It usually grows on Hyphoderma fruiting bodies.
References
External links
Pucciniomycotina
Fungi described in 1991
Fungus species | Colacogloea peniophorae | [
"Biology"
] | 101 | [
"Fungi",
"Fungus species"
] |
76,404,980 | https://en.wikipedia.org/wiki/RCW%20108 | RCW 108, also called the Rim Nebula, is a large star formation in the Milky Way, about 4,000 light years from Earth. RCW 108 is part of the Constellation Ara. is in the process of being destroyed by intense light which radiates from a star inside of NGC 6193. NGC 6188 has an angular extent of 20.0' × 12.0', and has been heavily documented by multiple telescopes, including Chandra and Spitzer.
Gallery
References
Milky Way
Emission nebulae
Gum Nebula
Ara (constellation) | RCW 108 | [
"Astronomy"
] | 112 | [
"Constellations",
"Ara (constellation)"
] |
76,405,293 | https://en.wikipedia.org/wiki/Alexei%20Tsvelik | Alexei Mikhaylovich Tsvelik () is a theoretical condensed matter physicist working on strongly correlated electron systems. He is widely recognised for his pioneering contributions to the theory of low-dimensional systems, including applications of non-perturbative quantum field theory methods and the Bethe Ansatz.
Education and Career
He graduated from the Moscow Physical Technical Institute in 1977,
before gaining his PhD in Theoretical Physics in 1980 from the
Kurchatov Institute for Atomic Energy. Between 1982 and 1989 he worked
at the Landau Institute for Theoretical Physics. After visiting
positions at Harvard, Princeton and the University of Florida, Tsvelik
was appointed as a Lecturer, and subsequently Professor, at the
University of Oxford (where he was affiliated to Brasenose College). In 2001 he was appointed as a Senior
Physicist and Group Leader at Brookhaven National Laboratory. He has also served as an adjunct professor of physics at Stony Brook University.
Research
Tsvelik has published more than 240 papers in refereed journals and is the
author of two textbooks and several books on popular science.
Throughout his career, Tsvelik has significantly contributed to the application of quantum field-theoretical methods to the description of low-dimensional systems, focusing on methods of Integrability, Bosonization and Conformal Field Theory.
Early in his career, he became known for his works on exact solutions of quantum impurity models, including the multichannel Kondo model using the Bethe Ansatz with Paul Wiegmann. Their 1983 review on exact results on impurity models including Kondo and Anderson impurity models remains a landmark in the use of exact methods in quantum many-body systems.
The late 1980s and early 1990s witnessed a concerted experimental and theoretical effort to understand the physics of Haldane gap materials. Field-theoretical methods such as the Landau-Ginzburg approach for the Non-linear sigma model for large-spin Heisenberg chains, and Tsvelik's Majorana fermion approach proved particularly useful for this purpose.
Separately, Tsvelik also used Majorana fermions to model unusual magnetoresistance properties of high-Tc materials in collaboration with Piers Coleman and Andy Schofield.
Similar approaches proved useful in the understanding of spin ladder materials, of interest as simplified versions of high-Tc materials. As shown by Tsvelik in collaboration with Nersesyan and Shelton, a two-leg ladder has a simple low-energy representation in terms of four (weakly interacting) massive Majorana fermions, enabling the calculation of dynamical structure factors.
In a collaboration with John Tranquada and others he established the existence of a Berezinskii–Kosterlitz–Thouless transition in a three dimensional layered high-temperature superconducting material.
A recent notable contribution of Tsvelik provides clear pathways in the search for new states of matter in the form of chiral spin liquids.
Awards and Recognitions
In 2002 Tsvelik was elected as a Fellow of the American Physical Society with citation For seminal contributions to quantum magnetism and for the exact solutions of important integrable models. He received a Brookhaven Science and Technology Award in
2006. In 2009 he was recognized as an Outstanding Referee by the
American Physical Society. He was awarded a Alexander von Humboldt Research Award in 2014
and the Eugene Feenberg Memorial Medal in 2024 "for pioneering applications of quantum field theory to the understanding of emergent, many-body physics of quantum systems, in particular the physics of magnetic impurities, disordered systems, and Majorana representations of correlated problems".
Hobbies
Tsvelik is a prolific caricaturist renowned among his colleagues for his blend of deference, humour and sarcasm. In particular, his textbooks contain many drawings of eminent physicists (a.k.a. "famous people nobody knows"). Alexei Tsvelik, in co-authorship with , published a series of metaphysical articles "Pythagorean Argument of the Intelligent Design of the Universe and its Critique", in the Russian journal "Ideas and Ideals".
References
External links
Professional website
ORCID profile
arXiv preprints
APS author profile
1954 births
Living people
Fellows of the American Physical Society
Theoretical physicists
Moscow Institute of Physics and Technology alumni | Alexei Tsvelik | [
"Physics"
] | 862 | [
"Theoretical physics",
"Theoretical physicists"
] |
76,407,981 | https://en.wikipedia.org/wiki/Biomass%20Energy%20and%20Alcohol%20Fuels%20Act | The Biomass Energy and Alcohol Fuels Act of 1980 is a statute that addresses general biomass energy development in its various forms, and the use of gasohol. It was one of six acts enacted by the U.S. Energy Security Act.
The purpose of the statute is to reduce the dependence of the United States on imported petroleum and natural gas. It is law that had been enacted by the U.S. Congress for the production and use of biomass energy. It also provided for the use of municipal waste biomass energy and rural, agricultural, and forestry biomass energy.
The Biomass Energy and Alcohol Fuels Act (BEAFA) consists of four subsections:
General Biomass Energy Development
Municipal Waste Biomass Energy
Rural, Agricultural, and Forestry Biomass Energy, and
Miscellaneous Biomass Provisions (The use of gasohol in Federal motor vehicles)
Roles of the Secretary of Agriculture and Secretary of Energy
For general biomass energy development, the Secretary of Agriculture and Secretary of Energy were required by the act to jointly prepare and transmit it to the President and the Congress, a plan for maximizing biomass energy production and use. The act required the plan to be designed to achieve a total level of alcohol production and use within the United States of at least 60,000 barrels per day of alcohol by December 31, 1982.
For municipal waste biomass energy, the Secretary of Energy was to prepare a report and transmit it to the President and Congress.
The Secretary of Agriculture was to prepare such a report for rural, agricultural, and forestry biomass energy.
References
Energy policy
Biomass | Biomass Energy and Alcohol Fuels Act | [
"Environmental_science"
] | 306 | [
"Environmental social science",
"Energy policy"
] |
76,408,069 | https://en.wikipedia.org/wiki/Basket-handle%20arch | A basket-handle arch (also depressed arch or chop arch) is characterized by an intrados profile formed by a sequence of circular arcs, each tangent to its neighbors, resulting in a smooth transition between arcs. The simplest form, a three-centered arch, consists of three arc segments with distinct centers, while a five-centered arch is also commonly used. This type of arch is prevalent in architectural applications, particularly in bridge construction. The shape of a basket-handle arch resembles that of a semi-ellipse, featuring a continuous curvature that varies from the extremities of the long axis to the apex of the short axis. It is also referred to as a depressed arch or basket arch, highlighting its distinctive curvature and structural function.
History
Since Roman times, bridge vaults have been built with semicircular arches, forming a complete half-circumference. From the early Middle Ages onwards, the segmental arch, an incomplete half-circumference, was used to build vaults that were less than half the height of their opening.
The pointed arch, which emphasizes height by rising above half the opening, did not see use in bridge construction until the Middle Ages.
The basket-handle arch appeared at the beginning of the Renaissance, offering aesthetic advantages over segmental vaults, notably through its end arches being vertically tangential to the supports.
The earliest applications of basket-handle arches in France can be seen in the Pont-Neuf in Toulouse, constructed in the 16th century, and the Pont Royal in the following century.
By the 18th century, the use of basket-handle arches became prevalent, particularly with three centers, as exemplified by the bridges at Vizille, Lavaur, Gignac, Blois (1716–1724), Orléans (1750–1760), Moulins (1756–1764), and Saumur (1756-1770).
Notable architect Jean-Rodolphe Perronet designed bridges with eleven centers during the latter half of the 18th century, including those at Mantes (1757–1765), Nogent (1766–1769), and Neuilly (1766–1774). The Tours bridge (1764–1777) also featured eleven centers. Other arches were generally reduced to one-third or slightly more, except for Neuilly, which was reduced to one-fourth.
In the 19th century, basket-handle arches were utilized in France's first major railroad bridges, including the Cinq-Mars bridge (1846–1847), Port-de-Piles bridge (1846–1848), Morandière bridges: Montlouis (1843–1845), and Plessis-les-Tours (1855–1857).
In England, while the Gloucester Bridge (1826–1827) and the London Bridge (1824–1831) were elliptical, the Waterloo Bridge in London (1816–1818) retained the basket-handle arch form.
Several basket-handle arches continued to be constructed into the late 19th and early 20th centuries. Notable examples include the Edmonson Avenue Bridge in Baltimore (1908–1909) with three centers, the Annibal Bridge (1868–1870) and Devil's Bridge (1870–1872) with five centers, the Emperor Francis Bridge in Prague (1898–1901) with seven centers, and the Signac Bridge (1871–1872) with nineteen centers.
In the United States, the Thomas Viaduct, featuring a basket-handle arch, was built between 1833 and 1835. It is now owned and operated by CSX Transportation and remains one of the oldest railroad bridges still in service.
Comparison between basket handle arch and ellipse
Aesthetics
Ancient architects placed considerable importance on the methods used to define the outline of the basket-handle arch. The flexibility inherent in these processes allowed for a wide variety of configurations, leading many architects to favor this type of curve over the ellipse, whose contour is rigidly determined by geometric principles.
In the case of an ellipse, the opening of a vault and the height at the center—corresponding to the major and minor axes—result in fixed points along the intrados curve, leaving no room for architectural modification. Conversely, the multi-center curve offers greater design freedom, allowing architects to adjust the curve’s base and apex according to their preferences, depending on the arrangement of the centers. This adaptability made the basket-handle arch an attractive option for those seeking aesthetic flexibility.
Advantages and disadvantages
The advantages of this layout approach were significant: the establishment of full-scale grooves was perceived as easier and more precise, allowing for immediate on-site layout of the normals and segment joints.
The number of voussoir shapes was constrained by the number of distinct radii employed, whereas for elliptical arches, this number was typically equal to half the number of voussoirs plus one.
However, the discontinuity of the layout led to the appearance of unsightly voussoirs, which could not always be removed during restoration work.
Tracing curves with three centers
The ancient oval
Although the basket-handle arch was not utilized for bridge vaults in ancient times, it found application in the construction of other types of vaults. Heron of Alexandria, who authored mathematical treatises more than a century before the Common Era, outlined a straightforward method for tracing this arch.
In Heron's method, if AB represents the width of the intended vault and the height (or rise) is undetermined, a half-circumference is described on AB. A vertical line OC is drawn through point C on this arc, and a tangent mn is constructed at point C. Lengths Cm and Cn are taken to be equal to half the radius of the arc. By connecting points mO and nO, points D and E are established. An isosceles triangle DOE is then traced, with its base equal to the height of the arch. Next, the line segment DA is divided into four equal parts, and parallels to DO are drawn through these division points (a, b, c). The intersections of these parallels with the horizontal axis AB and the extended vertical axis CO yield the necessary centers for tracing various curves with three centers along AB, often referred to as the ancient oval.
As the basket-handle arch became more prevalent in bridge construction, numerous procedures for tracing it emerged, leading to an increase in the number of centers used. The objective was to create perfectly continuous curves with an aesthetically pleasing contour. Given the indeterminate nature of the problem, certain conditions were often imposed arbitrarily to achieve the desired result.
For instance, it was sometimes accepted that the arcs of circles composing the curve must correspond to equal angles at the center, while at other times, these arcs were required to be of equal length. Additionally, either the amplitude of the angles or the lengths of the successive radii were allowed to vary according to specific proportions.
A consistent ratio between the lowering of the arch and the number of centers used to trace the intrados curve was also established. This lowering is measured by the ratio of the rise (b) to the width of the arch (2a), expressed as b/2a. Acceptable ratios may include one-third, one-quarter, or one-fifth; however, if the ratio falls below one-fifth, a circular arc is generally preferred over the basket-handle arch or ellipse. For steeper slopes, it is advisable to employ at least five centers, with some designs utilizing up to eleven centers, as seen in the curve of the Neuilly Bridge, or even up to nineteen for the Signac Bridge. As one of the centers must always be positioned on the vertical axis, the remaining centers are symmetrically arranged, resulting in an odd total number of centers.
The Huygens method
For constructing curves with three centers, Huyghens outlines a method that involves tracing arcs of varying radii corresponding to equal angles, specifically angles of 60 degrees.
To begin, let AB represent the opening and OE signify the arrow of the vault. From the center point O, an arc AMF is drawn using radius OA. The arc AM is then taken to be one-sixth of the circumference, meaning its chord equals the radius OA. The chords AM and MF are drawn, followed by a line Em through point E, which is the endpoint of the minor axis, parallel to MF.
The intersection of chords AM and Em determines point m, the boundary of the first arc. By drawing the line mP parallel to MO, points n and P are established as the two centers required for the construction. The third center n is positioned at a distance n'O from the axis OE, equal to nO.
Analysis of the figure reveals that the three arcs—Am, mEm', and m'B—comprise the curve and correspond to equal angles at the centers Anm, mPm', and m'n'B, all measuring 60 degrees.
The Bossut method
Charles Bossut proposed a more efficient method for tracing a three-center curve, which simplifies the process.
In this method, AB represents the opening and OE denotes the arrow of the vault, serving as the long and short axes of the curve. To begin, the line segment AE is drawn. From point E, a segment EF' is taken, equal to the difference between OA and OE. A perpendicular line is then drawn from the midpoint m of AF'. The points n and P, where this perpendicular intersects the major axis and the extension of the minor axis, serve as the two centers required for the construction.
When using the same opening and rise, the curve produced by this method exhibits minimal deviation from those generated by previous techniques.
Curves with more than three centers
For curves with more than three centers, the methods indicated by Bérard, Jean-Rodolphe Perronet, Émiland Gauthey, and others consisted, as for the Neuilly bridge, in proceeding by trial and error.
Tracing a first approximate curve according to arbitrary data, whose elements were then rectified, using more or less certain formulas, so that they passed exactly through the extremities of the major and minor axes.
The Michal method
In a paper published in 1831, mathematician Michal addressed the problem of curve construction with a scientific approach. He developed tables containing the necessary data to draw curves with 5, 7, and 9 centers, achieving precise results without the need for trial and error.
Michal's calculation method is applicable to curves with any number of centers. He noted that the conditions required to resolve the problem can be somewhat arbitrary. To address this, he proposed that the curves be constructed using either arcs of a circle that subtend equal angles or arcs of equal length. However, to fully determine the radii of these arcs, he also posited that the radii should correspond to the radii of curvature of an ellipse centered at the midpoint of each arc, where the opening serves as the major axis and the ascent functions as the minor axis.
As the number of centers increases, the resulting curve approximates the shape of an ellipse with the same opening and slope.
The following table illustrates the construction of a basket-handle arch, characterized by equal angles subtended by the various arcs that comprise it. The proportional values for the initial radii are calculated using half the opening as the unit of measurement. Additionally, the overhang is defined as the ratio of the arrow (the vertical distance from the highest point of the arch to the line connecting its endpoints) to the total opening.
The table provided allows for the straightforward construction of a basket-handle arch with any specified opening using five, seven, or nine centers, eliminating the need for extensive calculations. The only stipulation is that the drop must match one of the values proposed by Michal.
For instance, to draw a curve with seven centers, a 12-meter opening, and a 3-meter slope corresponding to a drop of one-quarter (or 0.25), the first and second radii can be calculated as follows: 6×0.265 and 6×0.419, resulting in values of 1.594 meters and 2.514 meters, respectively.
To inscribe the curve within a rectangle labeled ABCD, one would start by describing a semicircle on line segment AB, which serves as the diameter, and divide it into seven equal parts. Chords Aa, ab, bc, and cd are then traced, with chord cd representing a half-division.
On the AB axis, from point A, a length of 1.590 meters is measured to establish the first center, labeled m1. A parallel line with radius Oa is drawn through this point, intersecting chord Aa at point n, marking the endpoint of the first arc. From point n, a length of nm2 equal to 2.514 meters is measured to identify the second center, m2. A parallel line with radius Ob is drawn from point m2, while a parallel line to chord ab is drawn from point n. The intersection of these two parallels at point n′ defines the endpoint of the second arc.
Continuing this process, a parallel is drawn through point n′ to chord bc, and from point E, a parallel is drawn to chord cd. The intersection of these two lines at point n′′ is used to draw a parallel to radius Oc. The points m3 and m4, where this line intersects the extensions of radius n′m2 and the vertical axis, become the third and fourth centers. The final three centers, m5, m6, and m7, are positioned symmetrically relative to the first three centers m1, m2, and m3.
As illustrated in the figure, the arcs An, nn′, n′n′′, etc., subtend equal angles at their centers, specifically 51° 34' 17" 14'. Moreover, constructing a semi-ellipse with AB as the major axis and OE as the minor axis reveals that the arcs of the semi-ellipse, contained within the same angles as the circular arcs, possess a radius of curvature equal to that of the arcs themselves.
This method demonstrates the ease with which curves can be constructed with five, seven, or nine centers.
The Lerouge method
Following Mr. Michal's contributions, the subject was further explored by Mr. Lerouge, the chief engineer of the Ponts et Chaussées. Lerouge developed tables for constructing curves with three, five, seven, and even up to fifteen centers.
His approach diverges from Michal's methodology by stipulating that the successive radii must increase according to an arithmetic progression. This requirement means that the angles formed between the radii do not necessarily need to be equal, allowing for greater flexibility in the design of the curves.
References
Bibliography
Architecture
Piecewise-circular curves
Bridges
Arch bridges | Basket-handle arch | [
"Mathematics",
"Engineering"
] | 3,065 | [
"Structural engineering",
"Piecewise-circular curves",
"Euclidean plane geometry",
"Construction",
"Planes (geometry)",
"Bridges",
"Architecture"
] |
76,408,235 | https://en.wikipedia.org/wiki/Ocean%20Thermal%20Energy%20Conversion%20Act | The Ocean Thermal Energy Conversion Act of 1980 (OTECA) is an act authorized by Congress to address ocean thermal conversion. It is one of six acts enacted by the Energy Security Act of 1980. Ocean thermal energy conversion is the extraction of energy from the thermal differentials of subsea and surface water in regions with tropical oceans.
The OTECA activities by means of three main functions:
The regulation of ocean thermal energy conversion (OTEC) facilities and plantships.
Maritime financing of such facilities and plantships.
The enforcement of law and regulations concerning this issue.
OTECA establishes rules for the protection of the environment as well as to ensure the protection of life and property.
For the purposes of the Merchant Marine Act (1936), any ship providing service for OTEC facilities shall be considered "be deemed to be used in, and used in an essential service in, the foreign commerce or foreign trade of the United States." This was to allow financing under the 1936 act.
The act limits the ownership, construction and operation of offshore ocean thermal energy facilities and plantships to those licensed by the National Oceanic and Atmospheric Administration (NOAA).
References
Energy policy
Energy law | Ocean Thermal Energy Conversion Act | [
"Environmental_science"
] | 234 | [
"Environmental social science",
"Energy policy"
] |
76,408,329 | https://en.wikipedia.org/wiki/Robert%20Charles%20Thompson | Robert Charles Thompson (April 21, 1931 – December 10, 1995) was a Canadian-American mathematician, who gained an international reputation for his research on linear algebra and matrix theory.
Biography
Thompson grew up near Vancouver, British Columbia. He graduated from the University of British Columbia in 1955 with a B.Sc. and in 1957 with an M.Sc. In 1960 he graduated from with a Ph.D. in mathematics from Caltech. His Ph.D. thesis Commutators in the Special and General Linear Groups was supervised by Olga Taussky-Todd. In 1961 the Transactions of the American Mathematical Society published a paper based upon his thesis. In the 1961 paper and in two subsequent 1962 papers, he settled several important open questions. From 1963 to 1966 Thompson was a faculty member at the University of British Columbia. From 1966 until his death in 1995, he was a professor of mathematics at the University of California, Santa Barbara (UCSB). At UCSB, he began a career-long collaboration with Marvin Marcus on some research, as well as the founding and development of UCSB's Institute for the Interdisciplinary Application of Algebra and Combinatorics. Thompson and Marcus recruited several prominent mathematicians, including Ky Fan, Eugene Johnsen, Henryk Minc, and Morris Newman (now known for Newman's conjecture). UCSB's mathematics department gained fame for promoting research in linear algebra and matrix theory, influencing matrix research in Israel, Hong Kong, Portugal, Spain, and elsewhere.
Thompson was the author of four undergraduate textbooks and the author or co-author of more than 120 articles. He did important research on invariant factors, integral matrices, principal submatrices, and the Baker-Campbell-Hausdorff formula. His research was honored with his appointment as lecturer for the 1988 Johns Hopkins Summer Lecture Series.
Thompson was one of the founders of the International Linear Algebra Society (ILAS) and of the journal Linear and Multilinear Algebra. He was a contributing editor of Linear Algebra and its Applications (initiated in 1968) and an editor of the SIAM Journal on Matrix Analysis and Applications.
Upon his death in 1995, Robert C. Thompson was survived by his wife Natalie. In 1996 he was posthumously awarded the Hans Schneider Prize in Linear Algebra of the ILAS.
Selected publications
Articles
(over 190 citations)
(over 180 citations)
(over 270 citations)
1994
References
1931 births
1995 deaths
20th-century Canadian mathematicians
20th-century American mathematicians
Combinatorialists
Linear algebraists
University of British Columbia alumni
California Institute of Technology alumni
University of California, Santa Barbara faculty | Robert Charles Thompson | [
"Mathematics"
] | 520 | [
"Combinatorialists",
"Combinatorics"
] |
54,852,248 | https://en.wikipedia.org/wiki/2017%20fipronil%20eggs%20contamination | The 2017 fipronil eggs contamination is an incident in Europe and Asia involving the spread of fipronil insecticide which contaminated human-consumed chicken eggs and egg products.
History
Issue
Chicken eggs were found to contain fipronil and distributed to 15 European Union countries, Switzerland, and Hong Kong. Approximately 700,000 eggs are thought to have reached shelves in the UK alone. Fipronil contaminated eggs may have been sold for a long time prior to the discovery of high levels. Fipronil was used in a remedy to destroy the poultry mite.
Initial actions
Authorities in the Netherlands were alerted by an anonymous source in November 2016 that fipronil was being used in poultry farms, but failed to communicate the findings.
In July/August 2017 millions of chicken eggs were blocked from sale or withdrawn from the market in the Netherlands, Belgium, Germany and France after elevated levels of fipronil were discovered by the Dutch food and product safety board. About 180 Dutch farms were temporarily shut down. In early August, Aldi reported removing all eggs for sale in their German stores as a precaution.
Investigations
Because the use of fipronil is illegal in the production of food for human consumption in Europe, a criminal investigation was initiated.
Early investigation led to two companies: ChickFriend, a provider of pest control services in the Netherlands, suspected of knowingly using and selling DEGA-16 mixed with fipronil to hundreds of chicken farmers, and Poultry Vision in Belgium, accused of selling DEGA-16 mixed with fipronil to ChickFriend. DEGA-16 is a cleaning and sanitising natural product that is approved to clean chicken stables. The Dutch owners of ChickFriend were arrested during a large scale operation conducted by Dutch law enforcement agencies on 10 August.
The first results of an investigation by Belgian police led to the discovery of of fipronil that Poultry Vision had imported from a chemical manufacturing company in Romania.
The Dutch Safety Board announced on 8 August 2017 that an official investigation has been initiated.
On 21 April 2021 the two main suspects were each sentenced to one year incarceration.
In South Korea, authorities found fipronil-contaminated eggs, which were produced in Namyangju, on 14 August 2017. E-mart, Homeplus, and Lotte Mart stopped selling eggs temporarily on the same day.
Scientific tests carried in Germany on imported eggs to Malta found that eight of twenty had traces of fipronil, and the Maltese were informed to take measures in limiting the consumption to not more than two eggs per day.
Reported fipronil concentrations
The maximum residue limit (MRL) of fipronil in eggs is set at the detection limit of 0.005 mg/kg within the European Union, as is outlined in Regulation (EC) No 396/2005 of the European Parliament and of the Council of 23 February 2005.
Fipronil is classed as a WHO Class II moderately hazardous pesticide, and has a rat acute oral LD50 of 97 mg/kg.
The Dutch food and product safety board (NVWA) reported that the test results of one batch of eggs originating from one poultry farm in the Netherlands exceeded the threshold of 0.72 mg/kg. Eggs containing fipronil values above this threshold could have possible negative health effects.
References
2017 in the Netherlands
Adulteration
Egg farming
Food safety in the European Union
Food safety scandals
Scandals in the Netherlands
2017 disasters in the Netherlands
2017 disasters in Europe | 2017 fipronil eggs contamination | [
"Chemistry"
] | 717 | [
"Adulteration",
"Drug safety"
] |
54,852,305 | https://en.wikipedia.org/wiki/NGC%202659 | NGC 2659 is an open cluster in the constellation Vela. It was discovered by John Herschel on 3 February, 1835. It is of Trumpler class III3m. It is a young cluster, with age nearly 8 million years. The core of the cluster is 1.93 parsec (6.3 light years) across and the total radius is 3.6 pc (11.7 light years). The total number of stars that belong to the cluster is estimated to be 1,801 ± 608 stars and the total mass 857 ± 237 . Among its members, one is a Be star, with four more possible Be stars.
References
External links
2659
Vela (constellation)
Open clusters | NGC 2659 | [
"Astronomy"
] | 148 | [
"Vela (constellation)",
"Constellations"
] |
54,852,772 | https://en.wikipedia.org/wiki/Breakthrough%20curve | A breakthrough curve in adsorption is the course of the effluent adsorptive concentration at the outlet of a fixed bed adsorber. Breakthrough curves are important for adsorptive separation technologies and for the characterization of porous materials.
Importance
Since almost all adsorptive separation processes are dynamic -meaning, that they are running under flow - testing porous materials for those applications for their separation performance has to be tested under flow as well. Since separation processes run with mixtures of different components, measuring several breakthrough curves results in thermodynamic mixture equilibria - mixture sorption isotherms, that are hardly accessible with static manometric sorption characterization. This enables the determination of sorption selectivities in gaseous and liquid phase.
The determination of breakthrough curves is the foundation of many other processes, like the pressure swing adsorption. Within this process, the loading of one adsorber is equivalent to a breakthrough experiment.
Measurement
A fixed bed of porous materials (e.g. activated carbons and zeolites) is pressurized and purged with a carrier gas. After becoming stationary one or more adsorptives are added to the carrier gas, resulting in a step-wise change of the inlet concentration. This is in contrast to chromatographic separation processes, where pulse-wise changes of the inlet concentrations are used. The course of the adsorptive concentrations at the outlet of the fixed bed are monitored.
Results
Integration of the area above the entire breakthrough curve gives the maximum loading of the adsorptive material. Additionally, the duration of the breakthrough experiment until a certain threshold of the adsorptive concentration at the outlet can be measured, which enables the calculation of a technically usable sorption capacity. Up to this time, the quality of the product stream can be maintained. The shape of the breakthrough curves contains information about the mass transfer properties of the adsorptive-adsorbent system. These properties can be evaluated by applying simplified models and fitting to experimental data by simulations.
References
Surface science
Materials science
Colloidal chemistry | Breakthrough curve | [
"Physics",
"Chemistry",
"Materials_science",
"Engineering"
] | 427 | [
"Colloidal chemistry",
"Applied and interdisciplinary physics",
"Materials science",
"Colloids",
"Surface science",
"Condensed matter physics",
"nan"
] |
54,853,569 | https://en.wikipedia.org/wiki/NGC%207816 | NGC 7816 is a spiral galaxy located about 215 million light-years away in the constellation of Pisces. It was discovered by astronomer William Herschel on September 26, 1785.
One supernovae has been observed in NGC 7816: SN 2017gww (type II, mag. 17.9)
Pair with NGC 7818
NGC 7816 is listed as being in pair with the galaxy NGC 7818. NGC 7818 is also listed as being a disturbed member of the pair. However, due to the large difference in their recessional velocities, the two galaxies are not a true pair but an optical double.
See also
List of NGC objects (7001–7840)
References
External links
Spiral galaxies
Pisces (constellation)
7816
+1-1-18
00263
00016
Astronomical objects discovered in 1785 | NGC 7816 | [
"Astronomy"
] | 174 | [
"Pisces (constellation)",
"Constellations"
] |
54,854,413 | https://en.wikipedia.org/wiki/Scopuloides%20magnicystidiata | Scopuloides magnicystidiata is a species of crust fungus in the family Meruliaceae. This white rot species was described as new to science in 2003 by mycologists Robert Lee Gilbertson and Karen Nakasone. The type specimen was discovered growing on Cattley guava (Psidium cattleianum) in the South Hilo district of Hawaii. It has also been recorded in the Kalopa State Recreation Area growing on ironwood, and also on guava in Waipio Valley. The fungus is named for its prominent cystidia, which can be seen with a hand lens. A defining macroscopic characteristic is the translucent look of the fruit body when fresh, and its horny, brittle texture when dried.
References
Meruliaceae
Fungi described in 2003
Fungi of Hawaii
Fungi without expected TNC conservation status
Fungus species | Scopuloides magnicystidiata | [
"Biology"
] | 172 | [
"Fungi",
"Fungus species"
] |
54,854,483 | https://en.wikipedia.org/wiki/Mangave | Mangaves are plants formerly given the nothogenus name × Mangave. They are derived from hybridizing species in the genus Agave and the former genus Manfreda. Manfreda is now included in Agave, so the scientific name is obsolete. Mangaves are often employed as ornamental plants in dry environments, as they possess traits of durability found in both parents. Around 30–40 cultivars were available .
Development
The name × Mangave was first coined in 2005 by Tony Avent of Plant Delights Nursery and Carl Schoenfeld and Wade Roitsch of Yucca Do Nursery to describe two plants growing at Yucca Do Nursery in Hempstead, Texas. The plants originated from seed collected as Manfreda in the wild in Northern Mexico that were growing adjacent to plants of Agave mitis (A. celsii). Only two seedlings from the original seed batch were hybrids. Another cultivar of the plant, 'Bloodspot', was the product of breeding Agave maculata (then known as Manfreda maculosa) and Agave macroacantha in Japan.
Around the same time that 'Bloodspot' was being developed, these crosses were being made by others including Dr. John Lindstrom of the University of Arkansas and Tony Avent of Plant Delights Nursery/Juniper Level Botanic Garden in Raleigh, North Carolina. Two breakthroughs in the development of the hybrids came when Hans Hansen of Shady Oaks Nursery in Minnesota became the first person to successfully micropropagate mangaves. Both 'Bloodspot' and 'Macha Mocha' were tissue cultured in vitro, resulting in both becoming more widespread in cultivation. Tissue culture also resulted in two new cultivars derived from a mutation of 'Macho Mocha'. These were named 'Espresso' and 'Cappucino'.
Upon moving from Minnesota to Michigan to become a plant breeder for Walters Gardens, Hans Hansen dived deeper into mangave breeding, creating over 40 cultivars as of 2018.
Description
Mangaves resemble compact, symmetrical agaves with succulent leaves. They typically grow to high and up to wide, although some can grow up to high and wide. The leaves of the plant are stiff, sometimes fragile, and variable in foliage color and patterns. Mangaves flower in June and July, producing brown flowers.
Mangaves inherit the drought-resisting traits of their parent plants. They can resist high temperatures and direct sunlight, but prefer shade. The plant can survive below freezing temperatures, but can become damaged if the temperature drops below -6 degrees Celsius. Although their drought resistance makes them particularly desirable plants in hot, dry places such as California, they can also be cultivated in parts of countries like the United Kingdom. They lack the dangerous spines of many species of Agave.
Cultivars
About 30 cultivars were available . These include:
Agave 'Bad Hair Day' – compact, rosette arches
Agave 'Bloodspot' – grey-green leaves heavily marked with cranberry red spots and with maroon edges
Agave 'Cappucino' - white-centered leaves; mutation of 'Macha Mocha'
Agave 'Espresso' - white-edged leaves; mutation of 'Macha Mocha'
Agave 'Lavender Lady' – purple-silver rosettes, more frost-sensitive
Agave 'Macha Mocha' – gray-green leaves with brown-purple spots, coming together at the tips
Agave 'Pineapple Express' – spotted leaves
Agave 'Silver Fox' – pale grey, almost white leaves
References
External links
Photos of commercial ×Mangave at Juniper Level Botanical Garden photo gallery
Drought-tolerant plants
Garden plants of North America
Agavoideae
Historically recognized angiosperm genera
Hybrid plants | Mangave | [
"Biology"
] | 773 | [
"Hybrid plants",
"Plants",
"Hybrid organisms"
] |
54,854,621 | https://en.wikipedia.org/wiki/NGC%204860 | NGC 4860 is an elliptical galaxy in the constellation Coma Berenices. The galaxy was discovered on 21 April 1865 by Heinrich Louis d'Arrest.
With its distance from Earth being approximately 110 million parsecs, NGC 4860 belongs to the Coma Cluster, which consists of over 1,000 identified galaxies.
See also
List of galaxies
Comet Galaxy
References
External links
Deep Sky Catalog
4860
Coma Cluster
Coma Berenices
Elliptical galaxies
044539 | NGC 4860 | [
"Astronomy"
] | 90 | [
"Coma Berenices",
"Constellations"
] |
54,854,734 | https://en.wikipedia.org/wiki/NGC%204500 | NGC 4500 is a barred spiral galaxy in the constellation Ursa Major. The galaxy was discovered on April 17, 1789 by William Herschel. It is a blue compact galaxy.
Its distance from Earth is approximately 50 million parsecs.
See also
List of galaxies
Comet Galaxy
References
External links
Deep Sky Catalog
4500
Discoveries by William Herschel
Ursa Major
Barred spiral galaxies
041436
Markarian galaxies | NGC 4500 | [
"Astronomy"
] | 82 | [
"Ursa Major",
"Constellations"
] |
54,854,841 | https://en.wikipedia.org/wiki/Fomitopsis%20subfeei | Fomitopsis subfeei is a species of polypore fungus in the family Fomitopsidaceae. Found in southern China, it was reported as new to science in 2014 by mycologists Mei-Ling Han and Bao-Kai Cui. Characteristics of the fungus include perennial, effused-reflexed (partially crust-like and partially pileate) to pileate fruit bodies, a concentrically grooved cap surface, and a pinkish-brown to vinaceous-brown pore surface on the cap underside. Microscopic characters include spindle-shaped cystidioles, and small, oblong-ellipsoid spores measuring 4–5 by 1.9–2.5 μm. The fungus causes a brown rot on gymnosperms.
References
subfeei
Fungi described in 2014
Fungi of China
Taxa named by Bao-Kai Cui
Fungus species | Fomitopsis subfeei | [
"Biology"
] | 183 | [
"Fungi",
"Fungus species"
] |
54,855,489 | https://en.wikipedia.org/wiki/Rhinocladiella%20mackenziei | Rhinocladiella mackenziei is a deeply pigmented mold that is a common cause of human cerebral phaeohyphomycosis. Rhinocladiella mackenziei was believed to be endemic solely to the Middle East, due to the first cases of infection being limited to the region. However, cases of R. mackenziei infection are increasingly reported from regions outside the Middle East. This pathogen is unique in that the majority of cases have been reported from immunologically normal people.
History
Rhinocladiella mackenziei was first identified in 1993 as Ramichloridium mackenziei by C.K. Campbell & Al-Hedaithy when it was identified as the cause of eight cases of human cerebral phaeohyphomycosis. All eight patients had abscess formation and six of the patients had aspirated pus with branching hyphae. Campbell and Al-Hedaithy considered different genera for the un-named fungus, including Zasmidium, Leptodontidium, Ramichloridium, and Rhinocladiella. They elected to place it in the genus Ramichloridium based on morphological similarity. In previous publications, Naim-Ur-Rahman misidentified the fungus in the genus Cladosporium, while Al-Hedaithy et al (1988) considered it synonymous with Fonsecaea pedrosoi.
The genus Ramichloridium encompasses asexual species that produce upright, darkly pigmented, apically elongating, zig-zag-shaped conidiophores that produce single-celled conidia. It was first described in 1937 by Stahel as Ramichloridium musae but the genus was considered invalid as Stahel's publication lacked a Latin diagnosis. The genus Ramichloridium was re-introduced by de Hoog in 1977 typified by R. apiculatum.
Rhinocladiella mackenziei was treated in the genus Ramichloridium until Arzanlou and coworkers explored the phylogeny of Ramichloridium and its related genera through partial sequences of the 28S (LSU) rRNA gene and the ITS region. The fungus was found to cluster in the Chaetothyriales clade along with Rhinocladiella species and was subsequently transferred to the genus Rhinocladiella. One of the main features that helped distinguish Ramichloridium and Rhinocladiella is the presence of Exophiala-like budding cells in Rhinocladiella, which were also seen in R. mackenziei. Additionally, the conidiophores of R. mackenziei resemble undifferentiated from the vegetative hyphae in contrast to those in Ramichloridium that are differentiated.
Habitat and ecology
Rhinocladiella mackenziei is found in the hot and arid climates of temperate and tropical regions. It is considered endemic throughout the Middle East, specifically Saudi Arabia, Kuwait, and Qatar, and infections by this species have been observed in individuals from Afghanistan, Iran, and India. It is known less commonly to inhabit temperate and tropical regions. The environmental niche of R. mackenziei remains unknown. Another fungus associated with causing cerebral phaeohyphomycosis; Cladophialophora bantiana, has been isolated in one occasion from sawdust, which could also be a possible source of R. mackenziei. Due to the lack of knowledge about its environmental niche, it has been difficult to isolate R. mackenziei; and selective techniques such as the use of high temperatures, mouse vectors, alkyl benzenes and mineral oils are required. Enrichment of growth media with volatile aromatic hydrocarbons improves recovery of this agent, implying a role for aromatic hydrocarbon degradation in its environmental niche.
Morphology and reproduction
Rhinocladiella mackenziei is a black yeast-like fungus with holoblastic conidia (conidia that are produced by simple budding) that are broadly oval and more than 2μm wide. In vitro at 30 °C, R. mackenziei has smooth, pigmented, septate hyphae and narrower, pale brown aerial hyphae. Its conidiophores are undifferentiated or only slightly differentiated from vegetative hyphae, and produce brown, smooth-walled, oval conidia. Rhinocladiella mackenziei grows slowly in culture media. Colonies grown for a week at 30 °C on glucose peptone agar develop a dark grey-brown to black appearance with a black reverse, elevated center, and densely cottony texture. Rhinocladiella mackenziei grows poorly at 25 °C and is not to produce a sexual state.
Disease in humans
Rhinocladiella mackenziei is a black yeast-like neurotropic fungus and one of the three main causative agents of cerebral phaeohyphomycosis. Histologically, infection by this agent causes the cerebrospinal fluid to become blackish and necrotic, pus-filled lesions to develop in brain tissue. R. mackenziei is mostly found in brain abscesses of immunocompetent patients, however infection has been reported in conjunction with primary central nervous system lymphoma (PCNSL). Infection by this agent is associated with extremely high mortality despite aggressive antifungal treatment and surgery. Symptoms may include headaches, fevers, neurological deficits, seizures, hemiparesis and even psychotic behavior. Infection is thought to result from exposure to conidia through inhalation, ingestion or through skin lesions. Diagnosis of cerebral phaeohyphomycosis by R. mackenziei is confirmed by the microscopic observation of pigmented fungal elements in affected tissues combined with the identification of the agent by culture or genetic sequencing. Central nervous system colonization is thought to be secondary to spread through blood and lymph tissue. The basis for the affinity of R. mackenziei for brain tissue is unknown but has been hypothesized to involve the fungal melanin which acts as a virulence factor by allowing it to evade a human host's immune system and cross the blood–brain barrier. Melanin also protects the fungal cell wall from hydrolysis by scavenging the free radicals and hypochlorite produced by the immune system as well as helping to prevent antifungal drugs from entering the fungal pathogen.
Treatment
Untreated cerebral phaeohyphomycosis caused by Rhinocladiella mackenziei has a mortality rate of nearly 100%, although some case reports exist of documented survival of patients. Rhinocladiella mackenziei has been shown to be resistant to Amphotericin B, an antifungal drug commonly used to treat fungal infections, both in vivo and in vitro. Susceptibility to triazoles such as itraconazole, posaconazole and isavuconazole has been seen in 10 strains of R. mackenziei, though a mixture of amphotericin B, itraconazole and 5-flucytosine has been associated with poor outcome in animal and clinical studies. Approaches to disease management typically involve combined antifungal chemotherapy (combination therapy), surgical debridement and immunotherapy.
References
Eurotiomycetes
Animal fungal diseases
Fungi described in 1993
Fungus species | Rhinocladiella mackenziei | [
"Biology"
] | 1,503 | [
"Fungi",
"Fungus species"
] |
54,858,363 | https://en.wikipedia.org/wiki/Alexandria%20train%20collision | The Alexandria train collision occurred on 11 August 2017 near Khorshid station in the suburbs of the eastern edge of Alexandria, Egypt.
Crash
Two trains – one traveling from Port Said and the other from Cairo – crashed one into the rear of the other at 2:15 p.m. local time, killing at least 41 people and injuring another 179.
Reactions
On 11 August, President Abdel Fattah el-Sisi expressed his condolences for the victims and ordered government bodies to form an investigative task force to identify the cause of the accident and hold those responsible to account.
References
2017 in Egypt
21st century in Alexandria
August 2017 events in Egypt
Railway accidents in 2017
Train collisions in Egypt | Alexandria train collision | [
"Technology"
] | 141 | [
"Railway accidents and incidents",
"Rail accident stubs"
] |
54,859,077 | https://en.wikipedia.org/wiki/NGC%20464 | NGC 464 is a double star located in the Andromeda constellation. It was discovered in 1882 by Wilhelm Tempel.
References
External links
Andromeda (constellation)
0464
Double stars | NGC 464 | [
"Astronomy"
] | 41 | [
"Andromeda (constellation)",
"Constellations"
] |
54,859,162 | https://en.wikipedia.org/wiki/George%20McRoberts | George McRoberts (1839–1896) was a Scottish chemist and early explosives expert. He assisted Alfred Nobel in establishing the original Nobel Enterprises dynamite factory at Ardeer. He was a close colleague of Nobel and probably a close friend.
Life
He was born in 1839 in central Scotland the son of John N McRoberts and his wife, Sarah Ogle. He was educated at Falkirk Grammar School.
In 1870 he established a chemical factory at Westquarter in Falkirk, mainly producing sulphuric acid. Alfred Nobel bought the company in 1871 and started making detonators there, mainly for the Scottish coalfields. He was very impressed by McRoberts and in 1873 he moved him to the new British Dynamite Factory in Ardeer, North Ayrshire as its Manager, directly under Alfred Nobel, the first dynamite factory in the world. It was McRoberts and a partner John Downie who raised the £24,000 to build the factory rather than Nobel himself, who was yet to become rich from his invention. The company had its offices at 7 Royal Bank Place in Glasgow. The Chairman of the company was the Glasgow shipbuilder, Charles Randolph.
McRoberts was injured in an explosion during his early years there. He also built a second explosives factory at Pitsea in Essex in 1876.
In 1883 he was elected a Fellow of the Royal Society of Edinburgh his proposers being Sir James Dewar, William Dittmar, John Gray McKendrick and Robert Rattray Tatlock.
He died on 15 January 1896.
Family
He was married to Jane Paton.
References
1839 births
1896 deaths
People from Falkirk
Fellows of the Royal Society of Edinburgh
19th-century Scottish people
19th-century Scottish chemists
Alfred Nobel
Explosives engineers | George McRoberts | [
"Engineering"
] | 362 | [
"Explosives engineering",
"Explosives engineers"
] |
54,861,197 | https://en.wikipedia.org/wiki/NGC%204489 | NGC 4489 is a dwarf elliptical galaxy located about 60 million light-years away in the constellation of Coma Berenices. It was discovered by astronomer William Herschel on March 21, 1784. NGC 4489 is a member of the Virgo Cluster.
See also
List of NGC objects (4001–5000)
Messier 32
NGC 4458
NGC 4406
References
External links
Dwarf elliptical galaxies
Coma Berenices
4489
Virgo Cluster
41365
7655
Astronomical objects discovered in 1784 | NGC 4489 | [
"Astronomy"
] | 102 | [
"Coma Berenices",
"Constellations"
] |
54,863,336 | https://en.wikipedia.org/wiki/Nipple%20bleb | A nipple bleb is a blister on the nipple that can be filled with serous or other fluid. It may be pink or light yellow. It is thin-walled and may appear as a small blister, more than 5 mm in diameter. It can also be referred to as a bulla. Some clinicians may also include milk blisters as a type of bleb. In addition, a blocked Montgomery gland may also be called a nipple bleb though its cause is different than a milk or serous-filled bleb on the nipple. In some cases the bleb may be associated with an adjacent blocked sebaceous cyst.
It may be caused by a blocked pore that leads to seepage of milk or serous fluid under the epidermis. This causes a white 'bump' that appears opaque and shiny. If the bleb continues to block the flow of milk out of the breast it may develop into a blocked milk duct or even mastitis.
A nipple bleb is often treated by the woman herself since a warm saline soak and gentle washing may open the blister and cause it to drain.
Symptoms
Shapeless raised, smooth, shiny, pimple-like, tiny bumps filled with water/fluid formed on breasts or in and around the nipple pore might appear. The colour of these fluid in nipple blebs may vary from white, yellow or transparent. They become flat when pressure is applied on them or punctured with hands. This can cause discomfort or pain to the lactating mother while breastfeeding.
Treatment
In case of slight or painless blebs, it is advised to continue the breastfeed to unclog the milk duct or prevent it from clogging altogether. Breastfeeding mothers should make the baby latch properly. In case of pain after breastfeeding one can try wet, warm heating pads before and after each feeding. Ice packs can be soothing as well. One can massage the area applying gentle pressure around the duct to help loosen up the blockage. Tight-fitting bras should be avoided; if the cloth of the bra is rubbing against the nipples, a nursing pad can be used to ease the friction.
A doctor or lactation consultant should be consulted regarding the use of lecithin-based treatments or painkillers such as acetaminophen or ibuprofen.
See also
Areola
Intimate part
Inverted nipple
Lactation
Mammary gland
References
Bleb
Exocrine system
Glands
Secondary sexual characteristics
Mammal anatomy | Nipple bleb | [
"Biology"
] | 523 | [
"Exocrine system",
"Organ systems"
] |
54,863,674 | https://en.wikipedia.org/wiki/Van%20Genuchten%E2%80%93Gupta%20model | The Van Genuchten–Gupta model is an inverted S-curve applicable to crop yield and soil salinity relations. It is named after Martinus Theodore van Genuchten and Satyandra K. Gupta's work from the 1990s.
Equation
The mathematical expression is:
where Y is the yield, Ym is the maximum yield of the model, C is salt concentration of the soil, C50 is the C value at 50% yield, and P is an exponent to be found by optimization and maximizing the model's goodness of fit to the data.
In the figure: Ym = 3.1, C50 = 12.4, P = 3.75
Alternative one
As an alternative, the logistic S-function can be used.
The mathematical expression is:
where:
with Y being the yield, Yn the minimum Y, Ym the maximum Y, X the salt concentration of the soil, while A, B and C are constants to be determined by optimization and maximizing the model's goodness of fit to the data.
If the minimum Yn=0 then the expression can be simplified to:
In the figure: Ym = 3.43, Yn = 0.47, A = 0.112, B = -3.16, C = 1.42.
Alternative two
The third degree or cubic regression also offers a useful alternative.
The equation reads:
with Y the yield, X the salt concentration of the soil, while A, B, C and D are constants to be determined by the regression.
In the figure: A = 0.0017, B = 0.0604, C=0.3874, D = 2.3788. These values were calculated with Microsoft Excel
The curvature is more pronounced than in the other models.
See also
Maas–Hoffman model
References
Soil science
Mathematical modeling
Crops | Van Genuchten–Gupta model | [
"Mathematics"
] | 385 | [
"Applied mathematics",
"Mathematical modeling"
] |
54,863,717 | https://en.wikipedia.org/wiki/Brodie%27s%20Law%20%28act%29 | Brodie's Law is an amendment to the Victorian Crimes Act 1958 which makes serious bullying an offence punishable by a maximum penalty of 10 years' imprisonment. The law is named after Brodie Panlock, a 19-year-old who took her own life after being bullied at work. Brodie Panlock's parents, Damien and Rae Panlock, successfully lobbied the Victorian Government to make the amendment.
Brodie Panlock
Brodie Rae Constance Panlock grew up in the outer eastern suburbs of Melbourne in the Australian state of Victoria with her parents and two older brothers. In early 2005, at age 18, Panlock started working at Cafe Vamp in Hawthorn, an inner suburb of Melbourne. In March 2006, shortly after her 19th birthday, Panlock moved to a small flat in Hawthorn to be closer to work. Cafe Vamp helped Panlock with references and lent her the bond money for the flat. She worked 12 hours a day, 6 days a week, and was described as a "loyal employee" and a "buoyant, chirpy, compassionate, patient, giving girl" by co-workers. Panlock had plans to save enough money to travel overseas with her brother and his girlfriend before enrolling at TAFE to study social work.
Bullying
Panlock became involved in an intermittent intimate relationship with cafe manager Nicholas Smallwood in the fifteen months leading up to her death. Panlock became infatuated with Smallwood, but the attention was not returned.
In the last few months Panlock's relationship with Smallwood became unhealthy, according to coroner Peter White, who found that Smallwood and others "systematically bullied her, both physically and emotionally". Smallwood, fellow waiter Rhys MacAlpine and, to a lesser extent, chef Gabriel Toomey, called her names and told her she was fat, ugly and a whore. They kicked and spat on her, held her down and poured oil on her hair and clothes, covered her in chocolate sauce and filled her kit bag with fish oil. Other employees intervened without effect, and the cafe owner Marcus Da Cruz turned a blind eye to the behaviour.
In May 2006, after being kicked out of Smallwood's apartment, Panlock made a suicide attempt. Smallwood later taunted Panlock that she could not do it properly, and put poison in her handbag.
Final days
On 20 September 2006, Smallwood left her flat after Panlock had begged him to stay. She called a former school friend, Ashlea Cooper, who gave evidence to the inquest. Cooper recalled that Panlock "cried hysterically" and felt that she had made a fool of herself, saying:
Shortly after 11:00pm on 20 September 2006, Brodie attempted suicide in Hawthorn; she died from her injuries in The Alfred Hospital three days later.
Penalty
Four men and MAP Foundation, the company that owned Cafe Vamp, were charged with offences under the Occupational Health and Safety Act 2004 for their part in bullying Panlock. They pleaded guilty to the charges on 8 February 2010, at the Melbourne Magistrates' Court. They were ordered to pay $335,000 in fines as follows:
MAP Foundation – $220,000
Marcus Da Cruz – $30,000
Nicholas Smallwood – $45,000
Rhys MacAlpine – $30,000
Gabriel Toomey – $10,000
Law reform
Victoria
Damien and Rae Panlock successfully lobbied the Victorian Government to make changes to the law to include serious bullying as an offence punishable by imprisonment.
On 4 November 2010, the Victorian Attorney-General asked the Victorian Law Reform Commission to review the adequacy of Victoria's criminal laws in dealing with serious bullying. The request was made to ensure that perpetrators of serious bullying receive appropriate sanction under Victoria's criminal law. On 5 April 2011, the Attorney-General introduced the Crimes Amendment (Bullying) Bill 2011 to Parliament, which amended the offence of stalking under section 21A of the Crimes Act 1958, to include serious bullying as a crime carrying a maximum penalty of ten years. The Bill received royal assent on 7 June 2011, and commenced immediately; it is colloquially known as "Brodie's Law".
In the five years since the law's proclamation on 16 June 2011, 58 offenders were charged with 140 offences against Brodie's Law.
National
The Victoria Attorney-General Robert Clark announced that Brodie's Law would be discussed at the Standing Committee of Attorneys-General in November 2011.
The response by the Victorian government was backed by the Federal Assistant Treasurer, Bill Shorten. In September 2011 the New South Wales Government was examining the Victorian legislation.
Damien and Rae Panlock continued to lobby the federal government because they feared that the states would fail to agree on the matter. On 26 May 2012, they met with Australian Prime Minister Julia Gillard and Bill Shorten, now Minister for Workplace Relations, and made a joint announcement of a national parliamentary inquiry into bullying. The report was released on 25 November 2012, and "contained 23 recommendations including the adoption of a new national definition of 'workplace bullying', a workplace bullying 'hotline' and a legislative and regulatory framework." In response to the recommendations the Federal Parliament passed the Fair Work Amendment Act 2013 which gave the Fair Work Commission jurisdiction to hear and resolve "a workplace incidence of bullying".
Brodie's Law Foundation
In late 2012, Damien and Rae Panlock toured Victoria, using the first anniversary of the introduction of Brodie's Law to raise awareness about bullying.
Damien and Rae Panlock continue to tour Australia and speak in workplaces and at public events, to campaign against bullying. The foundation assists with education in workplaces, schools and sporting clubs, with speaking engagements and production of education packages for teachers, club members, employers, and employees.
In February 2017, Brodie's Law Foundation was formed and registered as a charity.
See also
Workplace bullying
Toxic workplace
Workplace aggression
References
External links
Brodie's Law Foundation
Victorian Department of Justice and Regulation
Suicides by jumping in Australia
Bullying
Victoria (state) legislation | Brodie's Law (act) | [
"Biology"
] | 1,212 | [
"Harassment and bullying",
"Behavior",
"Aggression"
] |
54,865,693 | https://en.wikipedia.org/wiki/John%20McVail | John Christie McVail FRSE LLD (22 October 1849- 29 July 1926) was a Scottish physician and public health expert. He helped to establish the National Health Insurance system in the UK.
Life
McVail was born on 22 October 1849 in Kilmarnock the second son of James McVail and his wife, . His older brother was David McVail (later Sir David McVail).
He was educated at Kilmarnock Academy then studied medicine first at the University of Glasgow and then at the University of St Andrews graduating with a MB Chb in 1873. He became a general practitioner in Kilmarnock, and gained his doctorate (MD) in 1875. Inspired by Henry Littlejohn in Edinburgh he developed an interest in public health and the application of statistics to public health. In 1885, he gained a Diploma in Public Health from the University of Cambridge and succeeded Dr Borland as Medical Officer of Health for the Kilmarnock area also becoming a Physician at Kilmarnock Infirmary. In 1891, he left Kilmarnock to become Medical Officer of Health for Stirlingshire and Dunbartonshire. From 1887 he was President of the Sanitary Association of Scotland.
In 1890, he was elected a Fellow of the Royal Society of Edinburgh his proposers being Joseph Bell, Andrew Wilson, Andrew Douglas Maclagan, and John Brown Buist. He resigned from the Society in 1908. In 1922, the Epidemiology section of the Royal Society of Medicine awarded him the Jenner Medal.
In 1922, he retired to Golders Green in London and then moved to Torquay on the south coast of England where he died on 29 July 1926.
Family
In 1877 he married Jessie Schoolbred Rowat. They had two sons and two daughters. His son John Borland McVail married the daughter of his friend John Glaister.
Publications
Vaccination Vindicated: Being an Answer to the Leading Anti-Vaccinators (1887)
Dr. C. Creighton, M.D. and Vaccination: A Review (1889)
Report to the Royal Commission on Poor Laws (1918)
References
1849 births
1926 deaths
People from Kilmarnock
Fellows of the Royal Society of Edinburgh
19th-century Scottish people
19th-century Scottish medical doctors
20th-century Scottish medical doctors
Vaccination advocates
Recipients of the Jenner Medal of the Royal Society of Medicine | John McVail | [
"Biology"
] | 487 | [
"Vaccination",
"Vaccination advocates"
] |
54,865,823 | https://en.wikipedia.org/wiki/NGC%20465 | NGC 465 is an open cluster in the Magellanic Clouds. Being part of the Tucana constellation, it was discovered by Scottish astronomer James Dunlop in 1826.
See also
List of NGC objects (1–1000)
References
External links
0465
Tucana
Open clusters
Discoveries by James Dunlop | NGC 465 | [
"Astronomy"
] | 59 | [
"Tucana",
"Constellations"
] |
54,866,314 | https://en.wikipedia.org/wiki/NGC%20468 | NGC 468 is a spiral galaxy in the constellation Pisces. Located approximately 209 million light-years from Earth, it was discovered by John Frederick William Herschel in 1827.
See also
List of galaxies
List of spiral galaxies
References
External links
Deep Sky Catalog
SEDS
468
Pisces (constellation)
Spiral galaxies
004780 | NGC 468 | [
"Astronomy"
] | 68 | [
"Pisces (constellation)",
"Constellations"
] |
54,866,690 | https://en.wikipedia.org/wiki/Maas%E2%80%93Hoffman%20model | The Maas–Hoffman model is a mathematical tool to characterize the relation between crop production and soil salinity. It describes the crop response by a broken line of which the first part is horizontal and the second is sloping downward. The breakpoint (Pb) or threshold is also called tolerance because up to that point the yield is unaffected by the salinity, so the salt is tolerated, while at greater salinity values the crops are affected negatively and the yield goes down.
Mathematics
Mathematically the two lines are represented by the equations:
where Y is the crop production or yield, C is the maximum yield, X is the soil salinity, A is the slope (regression coefficient) of the descending line, and B is the regression constant of that line.
In the example of the figure: C = 1.2, A = —0.10, Pb = 7.0
The value of Pb is to be found by regression analysis and optimization so that the goodness of fit of the data to the model is maximum.
The Maas–Hoffman model is used in crop tolerance to seawater.
Inverted model
For growth factors, like the depth of the watertable, that affect crop production negatively at low values while there is no effect at high values, the inverted Maas–Hoffman model can be used.
See also
Van Genuchten–Gupta model
References
Mathematical modeling
Crops
Soil science | Maas–Hoffman model | [
"Mathematics"
] | 286 | [
"Applied mathematics",
"Mathematical modeling"
] |
54,866,942 | https://en.wikipedia.org/wiki/NGC%204488 | NGC 4488 is a lenticular galaxy located about 60 million light-years away in the constellation of Virgo. The galaxy was discovered by astronomer William Herschel on December 28, 1785. NGC 4488 is a member of the Virgo Cluster.
Structure
NGC 4488 has an unusual rectangular-shaped structure similar to the galaxy LEDA 74886. The galaxy does not have an inner disk. It also has two arms coming off diagonally opposite sides suggesting that NGC 4488 has had a gravitational interaction with another galaxy.
See also
List of NGC objects (4001–5000)
LEDA 74886
Peculiar galaxy
References
External links
Lenticular galaxies
Virgo (constellation)
4488
Virgo Cluster
41363
7653
Astronomical objects discovered in 1785
Peculiar galaxies | NGC 4488 | [
"Astronomy"
] | 159 | [
"Virgo (constellation)",
"Constellations"
] |
54,867,983 | https://en.wikipedia.org/wiki/Pavona%20maldivensis | Pavona maldivensis is a species of colonial stony coral in the family Agariciidae. It is found on shallow reef slopes, particularly those with strong wave action, and on vertical surfaces, in tropical parts of the Indian and Pacific Oceans.
Description
Pavona maldivensis can be encrusting or massive, or a mixture of the two, and can form clumps over a metre in diameter, although colonies smaller than across are more usual. In areas with strong water movement they tend to form cylindrical, finger-like growths while elsewhere they may form horizontal plates, often with "leafy" edges. The corallites (stony cups in which the polyps sit) are circular and of irregular sizes, and have individual but indistinct stony walls. This coral is usually some shade of greyish-brown or green but can be bright orange.
Distribution and habitat
Though named "of the Maldives" (maldivensis), P. maldivensis has a wide distribution in tropical and subtropical waters. Its range extends from the Red Sea, Gulf of Aden and Madagascar, through the southwestern and central Indian Ocean, northern Australia, southern Japan and the South China Sea, to the western, central and eastern Pacific Ocean.
Ecology
Pavona maldivensis is a zooxanthellate species of coral; this means that its tissues contain symbiotic single celled algae which provide part of its nutritional requirements. These contain chlorophyll and tend to be some shade of brown or green, but in this coral there is an additional photosynthetic pigment, phycoerythrin. In daylight, this absorbs light at one wavelength and transmits it at another, giving a bright orange fluorescence.
In aquaria
Pavona maldivensis and other species in this genus are kept in reef aquariums where they are said to be easy small stony corals for beginners to care for.
References
Agariciidae
Animals described in 1905
Coral reefs | Pavona maldivensis | [
"Biology"
] | 413 | [
"Biogeomorphology",
"Coral reefs"
] |
54,868,300 | https://en.wikipedia.org/wiki/Nubia%20Technology | Nubia Technology is a Chinese smartphone manufacturer headquartered in Shenzhen, Guangdong. Originally established as a wholly owned subsidiary of ZTE in 2012, it became an independent company in 2015 and received a significant investment from Suning Holdings Group and Suning Commerce Group in 2016. ZTE reduced its stake in Nubia to 49.9% in 2017, officially meaning Nubia was no longer considered a subsidiary of ZTE, but more of an associate company.
In February 2016 Nubia became a sponsor of Jiangsu Suning F.C. for a reported .
The company hired footballer Cristiano Ronaldo to promote the mobile phone of the company in May 2016.
In 2017, China Daily reported that Nubia would build a factory in Nanchang, Jiangxi Province.
In April 2018, Nubia Technology launched a gaming sub-brand, named REDMAGIC (红魔). REDMAGIC announced its new 5G compatible device REDMAGIC 5G on March 12, 2020, in Shanghai. REDMAGIC is known for being the first smartphone brand to put cooling fans inside their phones. The company also unveiled a partnership with Chinese esport team Royal Never Give Up, to further expand its brand among esport enthusiasts.
On 13 April 2020, the company unveiled a brand new logo as well as its new brand vision.
In March 2022, Nubia unveiled the first gaming phone featuring an under-display camera technology, the REDMAGIC 7 Pro.
In 2023, Nubia released the Red Magic 8S Pro, touted as the strongest gaming phone to date.
In 2024, Nubia released the Red Magic 9S Pro+ with the highest Antutu smartphone score to date. In July 2024, RedMagic announced its entry in the computer category with its first gaming laptop, the Titan 16 Pro, available in China and global markets, while in September, they launched their first gaming tablet, the Nova gaming pad.
Products
Smartphone
RedMagic sub-brand
Nubia
Nubia Neo 2 2024
References
External links
Manufacturing companies based in Shenzhen
Mobile phone companies of China
Mobile phone manufacturers
Electronics companies of China
Chinese brands
Flexible displays
2015 in Shenzhen | Nubia Technology | [
"Materials_science",
"Mathematics"
] | 433 | [
"Flexible displays",
"Planes (geometry)",
"Thin films"
] |
54,869,297 | https://en.wikipedia.org/wiki/Tim%20Elliott%20%28geochemist%29 | Timothy Richard Elliott is a professor at the University of Bristol.
Education
Timothy Elliot was educated at the University of Cambridge and the Open University where he was awarded a PhD in 1991 for research investigating element fractionation in the petrogenesis of ocean island basalts.
Career and research
Elliott specialises in developing analytical approaches to yield novel isotopic means to reconstruct planetary histories. He has investigated production of melt from the Earth's interior and the chemical consequences of the return of solidified melts to depth via the plate tectonic cycle. In particular, he has assessed elemental fluxes from descending plates and has highlighted how the rise of atmospheric oxygen has been remarkably recorded in the isotopic composition of the deep, solid Earth. His recent focus on planetary growth has identified the rapid formation of metallic cores, how bulk chemistry is notably modified during early accretion and distinctively embellished in its terminal stages.
Awards and honours
Elliot was awarded the Murchison Medal by the Geological Society of London in 2017 and elected a Fellow of the Royal Society (FRS) in 2017.
References
Fellows of the Royal Society
Living people
Year of birth missing (living people)
Alumni of the University of Cambridge
Alumni of the Open University
Academics of the University of Bristol
British geochemists
Murchison Medal winners | Tim Elliott (geochemist) | [
"Chemistry"
] | 261 | [
"Geochemists",
"British geochemists"
] |
54,870,250 | https://en.wikipedia.org/wiki/Brando%20Huang | Brando Huang (; born 22 March 1981) is a Taiwanese actor and television host.
Early life and education
Born in Huwei, Yunlin, Huang attended Chien Hsin University of Science and Technology and graduated with a bachelor's degree in electronic engineering. After graduating, he became an engineer at Hsinchu Science and Industrial Park.
Career
Huang had an interest in performing since young. Discovered by comedian Hsu Hsiao-shun, Huang started out by making numerous appearances in television shows where he is known for impersonating famous personalities such as the comedian Kang Kang and musician Wu Bai.
Huang's first acting role was in the series Your Home is My Home, and he has appeared in several films and television series since, including Monga, Monga Yao Hui, Partners in Crime and At Cafe 6. In 2015, he earned a Golden Bell Award nomination for his role in the television film Let the Sunshine In.
Filmography
Television series
Film
Variety show
Music video appearances
Awards and nominations
References
External links
1981 births
Living people
People from Yunlin County
21st-century Taiwanese male actors
Taiwanese male film actors
Taiwanese male television actors
Taiwanese television presenters
Taiwanese engineers
Electronics engineers | Brando Huang | [
"Engineering"
] | 237 | [
"Electronics engineers",
"Electronic engineering"
] |
66,170,294 | https://en.wikipedia.org/wiki/Marie%20Jakus | Marie Agnes Jakus (born ) was an American biologist and microscopist specialized in electron microscopic studies of the fine structure of eye tissues. She was a researcher at the Massachusetts Institute of Technology, Retina Foundation, and the National Institute of Neurological Diseases and Blindness before becoming a science administrator at the Center for Scientific Review.
Early life and education
Jakus was born in Ohio to Hungarian immigrants, Anna H. Vintila (née Hovancsik) and Anton Jakus. She had a sister, Florence A. Frash. Jakus completed a B.A. from Oberlin College where she was a student assistant for 5 years. She was a member of Phi Beta Kappa and Sigma Xi. Jakus received a fellowship from Oberlin College in 1938 to study marine invertebrate zoology at Woods Hole Oceanographic Institution. She later worked as a graduate assistant at Washington University in St. Louis between 1938 and 1941, during which she received a fellowship in 1941 to return to Woods Hole to study physiology. Jakus joined the staff of the Massachusetts Institute of Technology (MIT) as a research assistant. At MIT, she began working toward her Ph.D. in biology, receiving it in 1945. Her dissertation was titled The Structure and Properties of the Trichocysts of Paramecium. Jakus' doctoral advisor was Francis O. Schmitt.
Career
Jakus remained at MIT as a research associate. During her 10 years there, she was awarded a Rockefeller Foundation Fellowship and took a year's sabbatical leave to study at the Institute for Cell Research at the Karolinska Institute. In 1951, Jakus joined the Retina Foundation where she developed a national reputation for electron microscopic studies of the fine structure of eye tissues. She has authored and coauthored publications dealing with electron microscopic and ocular studies, among them, a volume of electron micrographs of ocular tissues and papers describing the fine structure of collagen, paramyosin, trichocysts, and Descemet's membrane in the cornea.
Jakus joined the National Institute of Neurological Diseases and Blindness (NINDB) in 1961 as a program coordinator in vision in the extramural programs. ln this capacity, she was responsible for the administration of research grants and programming activities along disease-oriented lines for all disorders of the eye. She became a science administrator and joined the Center for Scientific Review as executive secretary in the visual sciences study section to review, analyze, evaluate, and process research grant applications. Jakus retired in 1977.
Jakus was a member of the Electron Microscopy Society of America, the American Association of Anatomists, and an honorary member of the Association for Research in Ophthalmology.
Personal life
Jakus was interested in photography, music, and reading. She was also a "Royal River Rat," a title she earned in 1968 when she shot the complete course of the Colorado River rapids between Lees Ferry and Temple Bar Marina in a rubber raft.
Selected works
References
20th-century American women scientists
Microscopists
20th-century American biologists
Oberlin College alumni
Massachusetts Institute of Technology alumni
Massachusetts Institute of Technology faculty
National Institutes of Health people
American women biologists
1910s births
American people of Hungarian descent
Biologists from Ohio
Date of death unknown
American women academics
Washington University in St. Louis alumni | Marie Jakus | [
"Chemistry"
] | 675 | [
"Microscopists",
"Microscopy"
] |
66,170,910 | https://en.wikipedia.org/wiki/Schepens%20Eye%20Research%20Institute | The Schepens Eye Research Institute, formerly known as the Retina Foundation Institute of Biological and Medical Sciences, is an independent nonprofit research foundation founded by ophthalmologist Charles Schepens that operates as part of the research program of Massachusetts Eye and Ear. In 1976, singer Ella Fitzgerald performed a benefit concert to show appreciation after her medical procedure. Doctors from the foundation occasionally travelled to India to perform operations for villagers. By 1964, 14 years after its establishment, the foundation had 88 staff members and received 60 percent of its funding from the government and the rest from private sector contributions. Frances Todman was named chairperson in 1985. She was a member of the national board of trustees and the corporation board. In 1986, the foundation employed over 100 researchers.
Notable people
Charles L. Schepens, founder and president
Endre Alexander Balazs, researcher
Marie Jakus, researcher
Ralph Lowell, chairperson
Frances Todman, chairperson
W. Clement Stone, chair of fundraising
Rao Sanadi, section chief of gerontology
References
1950 establishments in Massachusetts
Ophthalmology organizations
Medical research institutes in Massachusetts
Biological research institutes in the United States
Research institutes established in 1950
Biomedical research foundations | Schepens Eye Research Institute | [
"Engineering",
"Biology"
] | 239 | [
"Biotechnology organizations",
"Biomedical research foundations"
] |
66,170,969 | https://en.wikipedia.org/wiki/WASP-41 | WASP-41 is a G-type main-sequence star. Its surface temperature is 5450 K. WASP-41 is similar to the Sun in its concentration of heavy elements, with a metallicity Fe/H index of −0.080, but is much younger at an age of 2.289 billion years. The star does exhibit strong starspot activity, with spots covering 3% of the stellar surface.
Multiplicity surveys did not detect any stellar companions as of 2017.
Planetary system
In 2012, one planet, named WASP-41b, was discovered on a tight, circular orbit. The transmission spectrum taken in 2017 was gray and featureless. No atmospheric constituents could be distinguished. The planetary orbit of WASP-41b is slightly misaligned with the equatorial plane of the star, at a misalignment angle of 9.15°. Planetary equilibrium temperature is 1242 K.
Another planet, WASP-41c, was discovered in 2015. The planets are too far apart to significantly affect each other's orbits. The planetary equilibrium temperature of WASP-41c is 247 K.
References
Centaurus
Planetary transit variables
G-type main-sequence stars
Planetary systems with two confirmed planets
J12422849-3038235
CD-29 98732 | WASP-41 | [
"Astronomy"
] | 259 | [
"Centaurus",
"Constellations"
] |
66,173,003 | https://en.wikipedia.org/wiki/Variant%20%28biology%29 | In microbiology and virology, the term variant or genetic variant is used to describe a subtype of a microorganism that is genetically distinct from a main strain, but not sufficiently different to be termed a distinct strain. A similar distinction is made in botany between different cultivated varieties of a species of plant, termed cultivars.
Viruses
SARS-CoV-2
It was said in 2013 that "there is no universally accepted definition for the terms 'strain', 'variant', and 'isolate' in the virology community, and most virologists simply copy the usage of terms from others". The lack of precise definition continued in 2020; in the context of the Variant of Concern 202012/01 version of the SARS-CoV-2 virus, the website of the US Centers for Disease Control and Prevention (CDC) states, "For the time being in the context of this variant, the [terms "variant", "strain", and "lineage"] are generally being used interchangeably by the scientific community".
References
External links
Variant (biology) – Biology Online
Microbiology terms
Virology
Microbial population biology
Genetics
Infraspecific virus taxa
Infraspecific bacteria taxa | Variant (biology) | [
"Biology"
] | 254 | [
"Genetics",
"Microbiology terms"
] |
66,174,505 | https://en.wikipedia.org/wiki/%28Chloromethylene%29triphenylphosphorane | (Chloromethylene)triphenylphosphorane is the organophosphorus compound with the formula Ph3P=CHCl (Ph = phenyl). It is a white solid but is usually generated and used in situ as a reagent in organic synthesis. It is structurally and chemically related to methylenetriphenylphosphorane.
The reagent is prepared from the chloromethylphosphonium salt [Ph3PCH2Cl]Cl by treatment with strong base. The phosphonium compound is generated by treatment of triphenylphosphine with chloroiodomethane.
(Chloromethylene)triphenylphosphorane converts aldehydes to vinyl chlorides:
RCHO + Ph3P=CHCl → RCH=CHCl + Ph3PO
These vinyl chlorides undergo dehydrochlorination to give alkynes:
RCH=CHCl + NaN(SiMe3)2 → RC≡CH + NaCl + HN(SiMe3)2
Related compounds
(Iodomethylene)triphenylphosphorane
(Dichloromethylene)triphenylphosphorane
References
Organophosphorus compounds | (Chloromethylene)triphenylphosphorane | [
"Chemistry"
] | 270 | [
"Organophosphorus compounds",
"Organic compounds",
"Functional groups"
] |
66,174,650 | https://en.wikipedia.org/wiki/Heat%20pen | A heat pen (also known as a thermal stick) is a device used to mitigate the effects of an insect sting (e. g. wasp sting) or insect bite (e. g. mosquito bite) by briefly heating the skin.
Shape
The heat pen is available either as a pen-like device or as a USB-attachment for the smartphone.
Effect
A heat pen has a ceramic or metal plate at the tip, which heats to 50 to 60 °C. The heated plate is brought into contact with the area of skin affected by the insect bite for 3 to 10 seconds, causing the skin to briefly heat up to 53 °C (local hyperthermia). The heat activates various physiological processes. For example, it is assumed that the insect proteins are destroyed (denatured) and the body's histamine release is reduced. This results in symptom relief, for example itching is avoided. Due to the short application time, the skin is not damaged. The positive effect of the heat stick could be confirmed by a study, however employees of the manufacturer are the lead authors and may be biased.
The exact effect is not known; various mechanisms are discussed.
The same mode of action is also used to treat cold sores.
References
Medical devices | Heat pen | [
"Biology"
] | 258 | [
"Medical devices",
"Medical technology"
] |
66,175,166 | https://en.wikipedia.org/wiki/Future%20French%20aircraft%20carrier | The French Navy is actively planning for a future aircraft carrier (supercarrier) and new flagship. It is known in French as Porte-avions de nouvelle génération (PA-NG) for 'new generation aircraft carrier'. Construction of the PANG is expected to begin around 2031 and it is projected to enter service in about 2038; the year the aircraft carrier is due to be retired. The ship will be nuclear-powered and will feature the Electromagnetic Aircraft Launch System (EMALS) and Advanced Arresting Gear (AAG).
History
Context
The current French aircraft carrier, the nuclear-powered Charles de Gaulle, entered service on 18 May 2001. As the only aircraft carrier of the French Navy, the ship's maintenance periods leave France without an available aircraft carrier. As a result the PA2 project (French: Porte-Avions 2, "Aircraft Carrier 2") started in 2003 to study the feasibility of another carrier based on the design of the British Queen Elizabeth-class. The PA2 project was suspended in 2009 and ultimately cancelled in 2013.
In October 2018, French Minister of the Armed Forces Florence Parly announced the start of a second carrier programme, this time as replacement for Charles de Gaulle. The military planning legislation for 2019-2025 (Loi de programmation militaire 2019-2025) defined a 18-month, €40M study phase, to allow the President to decide on the main characteristics of the programme by 2020. In May 2020, during a visit to Chantiers de l'Atlantique, Parly stated that the new carrier would be built in Saint-Nazaire—as expected, since it is the only dry dock in France capable of harbouring ships of that size.
Architecture, propulsion options and number of ships were originally to be decided by President Macron in July 2020, to allow him to make the announcement at Bastille Day. However, on 6 July 2020, a governmental reshuffle put the Castex government in charge, forcing to delay the Defence Council to later in the year.
During a visit to the Framatome site at Le Creusot on 8 December 2020, President Macron officially announced the start of the PANG programme, and selection of nuclear propulsion for the new ship.
In 2022, Naval Group released new renderings of the carrier that included a revised island structure.
Construction
In May 2020, Defence minister Florence Parly stated that the PANG would be built in Saint-Nazaire at Chantiers de l'Atlantique.
Preliminary design work on new 220 MW K22 nuclear reactors to power the ship was completed in 2023. A production contract for the ship itself is anticipated in about 2025 with hull construction to begin in about 2031. Sea trials are projected to begin in around 2035.
See also
French aircraft carrier PA2 (previous effort to construct a new French aircraft carrier, canceled 2013)
Future of the French Navy
References
Proposed aircraft carriers
Aircraft carriers of the French Navy
Nuclear-powered ships of the French Navy | Future French aircraft carrier | [
"Engineering"
] | 610 | [
"Military projects",
"Proposed aircraft carriers"
] |
66,175,495 | https://en.wikipedia.org/wiki/Iod%C3%A9OS | iodéOS is an Android-based mobile operating system developed by French company iodé. The operating system is a fork of LineageOS and does not include Google Play Services, instead using MicroG as a free and open-source replacement.
Software
iodéOS is presented as a privacy-oriented fork of LineageOS combined with MicroG and a firewall. From 2020 through November 2022, IodéOS was closed source and included proprietary apps. In November 2022, the company announced it was releasing version 3.3 as "open source" with options for uninstalling default apps. No license terms were specified, and multiple licenses can be found in each repository on GitLab, including Apache2 and AGPL
IodeOS comes with a set of default apps and utilities that can be optionally installed upon startup. Among these are app stores: F-Droid and Aurora Store, MicroG, the Iodé browser, which is based on Firefox, Thunderbird as email client, Magic Earth for maps, and the Iodé app (a tracking-prevention control center), and parental control.
Reception
According to Stefan Mey of Heise.de and "Sunny" of tarnkappe.info, iodéOS includes hosts file based ad and tracker blocking. According to "Sunny" of tarnkappe.info, users may install a VPN or an additional adblocker. According to Stefan Mey of heise.de, the operating system comes with F-Droid and Aurora Store app stores pre-installed. Manuel Vonau of AndroidPolice.com said it was "good" that the setup of a pre-installed phone isn't "much more complicated than with any other phone." However, inclusion of the Aurora Store meant the operating system still communicated with Google APIs and breaks Google's Terms of Service, but no warning is given.
In a review of iodeOS in April 2023, pentester Mike Kuketz said "iodéOS has been relatively successful in reducing Google's data collection mania - but not completely." As examples, to speed up location, the system accesses the Google SUPL server, and the included browser uses Google Safe Browsing. Kuketz warned, if you enable microG, more connections to Google will be made. Other criticisms included: Delayed delivery of (security) updates; Older devices do not receive full security updates of proprietary components like bootloader or firmware; and iodéOS does not support Verified Boot on every device. Kuketz concluded, "iodéOS could be improved especially by faster delivery of (security) updates. Overall, however, some restrictions in terms of security have to be accepted. Ultimately, iodéOS is mainly aimed at privacy-sensitive users who want to continue using their (older) devices."
See also
Comparison of mobile operating systems
Criticism of Google
DeGoogle
List of custom Android distributions
References
External links
Android (operating system) forks
Custom Android firmware
Free mobile software
Mobile operating systems | IodéOS | [
"Technology"
] | 619 | [
"Operating system stubs",
"Computing stubs"
] |
66,175,500 | https://en.wikipedia.org/wiki/Dana%20Carroll | Dana Carroll is an American molecular biologist and biochemist at the University of Utah School of Medicine who has made important contributions to the field of genome editing. He has been a member of the National Academy of Sciences since 2017.
References
Living people
Year of birth missing (living people)
American molecular biologists
Genome editing
United States National Academy of Sciences
Place of birth missing (living people) | Dana Carroll | [
"Engineering",
"Biology"
] | 77 | [
"Genetics techniques",
"Genetic engineering",
"Genome editing"
] |
66,177,504 | https://en.wikipedia.org/wiki/HD%20136138 | HD 136138, or HR 5692, is a binary star system in the Serpens Caput segment of the Serpens constellation. It has a golden hue like the Sun and is dimly visible to the naked eye with an apparent visual magnitude of 5.68; the light contribution from the companion is effectively negligible. This system is located at a distance of approximately 420 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −7.7 km/s and has a proper motion of ·yr−1.
The radial velocity variation of this star was reported by J. R. de Medeiros and M. Mayor in 1999, and it was confirmed as a binary by A. Frankowski and colleagues in 2007 using proper motion measurements. It is an unresolved, single-lined spectroscopic binary system with an orbital period of and an eccentricity (ovalness) of 0.335. Proper motion measurements allow an estimate of the orbital inclination angle as ~43°. Their semimajor axis is around , or double the distance from the Earth to the Sun.
The stellar classification of the primary component is G8IIIa, indicating this is a evolved G-type giant star that has exhausted the supply of hydrogen at its core. It is a red clump giant that is generating energy through core helium fusion. There is some ambiguous evidence for this being a mild barium star of class Ba0.3, with the spectra showing marginal overabundances of s-process elements. A low level of X-ray emission has been detected, which appears to be coming from the star's corona.
The high level of ultraviolet flux coming from this system strongly suggests the companion is a compact white dwarf. Mass estimates put it in the range of 0.6 to 0.8 times the mass of the Sun, and the temperature is around 30,400 K. It is possible that the earlier evolution of this component contaminated its partner with s-process elements, although the resulting interaction should have circularized the orbit to some degree. The dwarf has a visual magnitude of 15.3 and a hydrogen-dominated atmospheric class of DA1.7.
References
G-type giants
Barium stars
Horizontal-branch stars
White dwarfs
Spectroscopic binaries
Serpens
5692
BD+21 2755
136138
074896 | HD 136138 | [
"Astronomy"
] | 490 | [
"Constellations",
"Serpens"
] |
66,177,541 | https://en.wikipedia.org/wiki/EF-24 | EF-24 is a compound that is a synthetic analogue of curcumin, a bioactive phytochemical from turmeric. Curcumin has antioxidant, antibiotic, anti-inflammatory and anti-cancer properties in vitro but has low potency and very poor bioavailability when taken orally, resulting in limited efficacy. EF-24 was developed to try to improve upon these properties, and has been found to be around 10 times more potent than curcumin and with much higher systemic bioavailability. It has never been developed for medical use, though research continues to investigate whether it may be useful as an adjuvant treatment for some cancers alongside conventional chemotherapy drugs.
References
Anti-inflammatory agents | EF-24 | [
"Chemistry"
] | 156 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
66,178,339 | https://en.wikipedia.org/wiki/Honoured%20Doctor%20of%20the%20People | Honoured Doctor of the People () was the highest honorary title awarded to physicians in East Germany. It was given in form of a medal. The title was stablished on 31 March 1949 and awarded every year on 11 December, the birthday of Robert Koch.
Sources
Bundesministerium für innerdeutsche Beziehungen (Hrsg.): DDR-Handbuch, Auszeichnungen, Verlag Wissenschaft und Politik, 1985, S. 26 und 29, .
Andreas Herbst, Winfried Ranke, Jürgen R. Winkler: So funktionierte die DDR, Lexikon der Organisationen und Institutionen; Gesundheitswesen, Rowohlt Taschenbuch, 1994, .
Health care in East Germany
Honorary titles
Medicine awards
Awards established in 1949
1949 establishments in East Germany
Orders, decorations, and medals of East Germany | Honoured Doctor of the People | [
"Technology"
] | 182 | [
"Science and technology awards",
"Medicine awards"
] |
66,180,125 | https://en.wikipedia.org/wiki/Geometric%20Constructions | Geometric Constructions is a mathematics textbook on constructible numbers, and more generally on using abstract algebra to model the sets of points that can be created through certain types of geometric construction, and using Galois theory to prove limits on the constructions that can be performed. It was written by George E. Martin, and published by Springer-Verlag in 1998 as volume 81 of their Undergraduate Texts in Mathematics book series.
Topics
Geometric Constructions has ten chapters. The first two discuss straightedge and compass constructions, including many of the constructions from Euclid's Elements, and their algebraic model, the constructible numbers. They also include impossibility results for the classical Greek problems of straightedge and compass construction the impossibility of doubling the cube and trisecting the angle are proved algebraically, while the impossibility of squaring the circle and constructing some regular polygons is mentioned but not proved.
The next four chapters study what happens when the use of the compass or straightedge is restricted: by the Mohr–Mascheroni theorem there is no loss in constructibility if one uses only a compass, but a straightedge without a compass has significantly less power, unless an auxiliary circle is provided (the Poncelet–Steiner theorem). These chapters also discuss the restriction of compasses to dividers, tools that can transfer line segments onto equal segments of other lines but cannot be used to find intersections of circles with other curves, or to rusty compasses, compasses that cannot change radius, and they use dividers to construct the Malfatti circles.
The final three chapters go beyond the straightedge and compass to other construction tools. A highly restricted form of construction, the "match-stick geometry" of Thomas Rayner Dawson from the 1930s, uses only unit line segments, which can be placed along each other, intersected, or pivoted around one of their endpoints; despite its limited nature, this turns out to be as powerful as straightedge and compass. Chapter 9 considers neusis constructions with a marked ruler, and the final chapter investigates the mathematics of paper folding; the marked ruler and paper folding models are equivalent algebraically, and both allow constructions for angle trisection.
As well as the mathematics it describes, Geometric Constructions includes many pieces of historical background, quotations and pointers to source material for additional reading, and solutions and hints to its many exercises.
Audience and reception
Martin originally intended his book to be a graduate-level textbook for students planning to become mathematics teachers. However, as well as this use, it can also be read by anyone who is interested in the history of geometry and has an undergraduate-level background in abstract algebra, or used as a reference work on the topic of geometric constructions.
Reviewer Horst Martini writes that it "conveys joy in the subject", while Maurice Burke describes the book as one that "invites the reader to play the game, take frequent side trips—many unexpected, and enjoy the ride".
References
Mathematics textbooks
1998 non-fiction books
Euclidean plane geometry
Algebraic numbers | Geometric Constructions | [
"Mathematics"
] | 613 | [
"Euclidean plane geometry",
"Mathematical objects",
"Algebraic numbers",
"Planes (geometry)",
"Numbers"
] |
66,180,640 | https://en.wikipedia.org/wiki/SRT-2104 | SRT-2104 is an experimental drug that was studied by Sirtris Pharmaceuticals as a small-molecule activator of the sirtuin subtype SIRT1. The compound progressed to Phase II human trials for Type II diabetes before development was discontinued, however it continues to be widely used in animal research into the functions of SIRT1.
See also
SRT-1460
SRT-1720
SRT-2183
SRT-3025
STAC-9
References
Anti-aging substances
4-Morpholinyl compounds
Thiazoles
3-Pyridyl compounds
Amides
Imidazothiazoles | SRT-2104 | [
"Chemistry",
"Biology"
] | 129 | [
"Pharmacology",
"Anti-aging substances",
"Functional groups",
"Medicinal chemistry stubs",
"Senescence",
"Pharmacology stubs",
"Amides"
] |
61,191,761 | https://en.wikipedia.org/wiki/Journal%20of%20Separation%20Science | The Journal of Separation Science is a biweekly peer-reviewed scientific journal covering analytical chemistry. It was established in 1978 as the Journal of High Resolution Chromatography & Chromatography Communications: HRC & CC. In 1989, it was renamed the Journal of High Resolution Chromatography. It obtained its current name in 2001, when it also absorbed the preexisting Journal of Microcolumn Separations, which had been established in 1989. It is an organ of the European Society for Separation Science and the California Separation Science Society. The editor-in-chief is František Švec (Charles University). According to the Journal Citation Reports, the journal has a 2020 impact factor of 3.645, ranking it 25th out of 83 journals in the category "Chemistry, Analytical".
References
External links
Analytical chemistry
Chemistry journals
Wiley-VCH academic journals
Academic journals established in 1978
Semi-monthly journals
English-language journals | Journal of Separation Science | [
"Chemistry"
] | 194 | [
"nan"
] |
61,191,884 | https://en.wikipedia.org/wiki/NGC%20972 | NGC 972 is a dusty spiral galaxy in the northern constellation of Aries, located at an approximate distance of from the Milky Way. It was discovered in 1784 by William Herschel. The galactic features suggest it may have undergone a merger with a gas-rich companion, giving it asymmetrical arms, plus starburst activity in the nucleus and an off-planar nuclear ring. The inner 3.6 kpc of the galaxy is undergoing star formation at the rate of 2.1–2.7 ·yr−1, but it lacks a nuclear bulge.
On October 16, 2008, a possible supernova event was observed about west and north of the Galactic Center. It reached magnitude 14.7 in the infrared K' band, but only a possible very faint transient event was observed in the visual frequency range, most likely as a result of strong extinction.
The group of galaxies around NGC 972 is sometimes referred to as the "NGC 972 group," which includes NGC 1012, NGC 1056, UGC 1958, UGC 2017, UGC 2053, and UGC 2221.
References
External links
NGC 972 on SIMBAD
Spiral galaxies
972
Aries (constellation)
009788 | NGC 972 | [
"Astronomy"
] | 251 | [
"Aries (constellation)",
"Constellations"
] |
61,194,642 | https://en.wikipedia.org/wiki/Teegarden%27s%20Star%20b | Teegarden's Star b (also known as Teegarden b) is an exoplanet found orbiting within the habitable zone of Teegarden's Star, an M-type red dwarf 12.5 light years away from the Solar System. It had the highest Earth Similarity Index (ESI) of any exoplanet, but in February 2024 a new study updated the parameters of the planet, thus reducing its ESI to 0.90, making it no longer the planet with the hightest ESI. Along with Teegarden's Star c, it is among the closest known potentially habitable exoplanets.
Discovery
In July 2019, a team of more than 150 scientists led by Mathias Zechmeister published a peer-reviewed article in Astronomy & Astrophysics as part of the CARMENES survey supporting the existence of two candidate exoplanets orbiting Teegarden's Star.
Because of the alignment and faintness of Teegarden's Star, Doppler spectroscopy (also known as the radial velocity method) was necessary to detect possible exoplanets. This method detects exoplanets indirectly by observing their effects on a host star's radial velocity, the speed at which it is moving towards or away from the Earth. These radial velocity anomalies in turn produce doppler shifts observable with a spectrograph-equipped telescope of sufficient power.
To accomplish this, the team used the CARMENES instrument on the 3.5-meter telescope of Spain's Calar Alto Observatory. After three years of observation, two periodic radial velocity signals emerged: one at 4.91 days (Teegarden's Star b) and another at 11.41 days (Teegarden's Star c).
Physical characteristics
Mass and orbit
Teegarden's Star b is the innermost known planet orbiting Teegarden's Star, with an orbital period of just 4.91 days. The planet's minimum mass is 1.05 Earth masses (); this value would be the true mass if the planet's orbit is not inclined from the Earth's perspective. Because of this, Teegarden's Star b is likely to be rocky. Astronomers estimate that Teegarden's Star b has a 60 percent chance of having liquid water, but only a 3 percent chance of having an atmosphere.
Host star
Teegarden’s Star is a low-mass red dwarf, with a mass of around 9 percent the mass of the Sun, and with a temperature of around 2,900 Kelvin (2,623 °C or 4,760 F). Due to the very low temperature and luminosity of Teegarden's Star, it was only discovered in 2003, since it has an apparent magnitude of only 15.1 (and an absolute magnitude of 17.22). Like most red and brown dwarfs, it emits most of its energy in the infrared spectrum. It is also older than the Sun, with an age of at least 8 billion years.
Habitability
Teegarden's Star b orbits within the habitable zone of its host star, meaning it is possible that its atmospheric composition could allow for stable liquid water on its surface, which could have also allowed the development of life.
See also
List of nearest exoplanets
List of potentially habitable exoplanets
References
Exoplanets discovered in 2019
Aries (constellation)
Exoplanets detected by radial velocity
Near-Earth-sized exoplanets in the habitable zone | Teegarden's Star b | [
"Astronomy"
] | 725 | [
"Aries (constellation)",
"Constellations"
] |
61,194,766 | https://en.wikipedia.org/wiki/Time-domain%20diffuse%20optics | Time-domain diffuse optics or time-resolved functional near-infrared spectroscopy is a branch of functional near-Infrared spectroscopy which deals with light propagation in diffusive media. There are three main approaches to diffuse optics namely continuous wave (CW), frequency domain (FD) and time-domain (TD). Biological tissue in the range of red to near-infrared wavelengths are transparent to light and can be used to probe deep layers of the tissue thus enabling various in vivo applications and clinical trials.
Physical concepts
In this approach, a narrow pulse of light (< 100 picoseconds) is injected into the medium. The injected photons undergo multiple scattering and absorption events and the scattered photons are then collected at a certain distance from the source and the photon arrival times are recorded. The photon arrival times are converted into the histogram of the distribution of time-of-flight (DTOF) of photons or temporal point spread function. This DTOF is delayed, attenuated and broadened with respect to the injected pulse. The two main phenomena affecting photon migration in diffusive media are absorption and scattering. Scattering is caused by microscopic refractive index changes due to the structure of the media. Absorption, on the other hand, is caused by a radiative or non-radiative transfer of light energy on interaction with absorption centers such as chromophores. Both absorption and scattering are described by coefficients and respectively.
Multiple scattering events broaden the DTOF and the attenuation of a result of both absorption and scattering as they divert photons from the direction of the detector. Higher scattering leads to a more delayed and a broader DTOF and higher absorption reduces the amplitude and changes the slope of the tail of the DTOF. Since absorption and scattering have different effects on the DTOF, they can be extracted independently while using a single source-detector separation. Moreover, the penetration depth in TD depends solely on the photon arrival times and is independent of the source-detector separation unlike in CW approach.
The theory of light propagation in diffusive media is usually dealt with using the framework of radiative transfer theory under the multiple scattering regime. It has been demonstrated that radiative transfer equation under the diffusion approximation yields sufficiently accurate solutions for practical applications. For example, it can be applied for the semi-infinite geometry or the infinite slab geometry, using proper boundary conditions. The system is considered as a homogeneous background and an inclusion is considered as an absorption or scattering perturbation.
The time-resolved reflectance curve at a point from the source for a semi-infinite geometry is given by
where is the diffusion coefficient, is the reduced scattering coefficient and is asymmetry factor, is the photon velocity in the medium, takes into account the boundary conditions and is a constant.
The final DTOF is a convolution of the instrument response function (IRF) of the system with the theoretical reflectance curve.
When applied to biological tissues estimation of and allows us to then estimate the concentration of the various tissue constituents as well as provides information about blood oxygenation (oxy and deoxy-hemoglobin) as well as saturation and total blood volume. These can then be used as biomarkers for detecting various pathologies.
Instrumentation
Instrumentation in time-domain diffuse optics consists of three fundamental components namely, a pulsed laser source, a single photon detector and a timing electronics.
Sources
Time-domain diffuse optical sources must have the following characteristics; emission wavelength in the optical window i.e. between 650 and 1350 nanometre (nm); a narrow full width at half maximum (FWHM), ideally a delta function; high repetition rate (>20 MHz) and finally, sufficient laser power (>1 mW) to achieve good signal to noise ratio.
In the past bulky tunable Ti:sapphire Lasers were used. They provided a wide wavelength range of 400 nm, a narrow FWHM (< 1 ps) high average power (up to 1W) and high repetition (up to 100 MHz) frequency. However, they are bulky, expensive and take a long time for wavelength swapping.
In recent years, pulsed fiber lasers based on super continuum generation have emerged. They provide a wide spectral range (400 to 2000 ps), typical average power of 5 to 10 W, a FWHM of < 10ps and a repetition frequency of tens of MHz. However, they are generally quite expensive and lack stability in super continuum generation and hence, have been limited in there use.
The most wide spread sources are the pulsed diode lasers. They have a FWHM of around 100 ps and repetition frequency of up to 100 MHz and an average power of about a few milliwatts. Even though they lack tunability, their low cost and compactness allows for multiple modules to be used in a single system.
Detectors
Single photon detector used in time-domain diffuse optics require not only a high photon detection efficiency in the wavelength range of optical window, but also a large active area as well as large numerical aperture (N.A.) to maximize the overall light collection efficiency. They also require narrow timing response and a low noise background.
Traditionally, fiber coupled photomultiplier tubes (PMT) have been the detector of choice for diffuse optical measurements, thanks mainly due to the large active area, low dark count and excellent timing resolution. However, they are intrinsically bulky, prone to electromagnetic disturbances and they have a quite limited spectral sensitivity. Moreover, they require a high biasing voltage and they are quite expensive. Single photon avalanche diodes have emerged as an alternative to PMTS. They are low cost, compact and can be placed in contact, while needing a much lower biasing voltage. Also, they offer a wider spectral sensitivity and they are more robust to bursts of light. However, they have a much lower active area and hence a lower photon collection efficiency and a larger dark count. Silicon photomultipliers (SiPM) are an arrays of SPADs with a global anode and a global cathode and hence have a larger active area while maintaining all the advantages offered by SPADs. However, they suffer from a larger dark count and a broader timing response.
Timing electronics
The timing electronics is needed to losslessly reconstruct the histogram of the distribution of time of flight of photons. This is done by using the technique of time-correlated single photon counting (TCSPC), where the individual photon arrival times are marked with respect to a start/stop signal provided by the periodic laser cycle. These time-stamps can then be used to build up histograms of photon arrival times.
The two main types of timing electronics are based on a combination of time-to-analog converter (TAC) and an analog-to-digital converter (ADC), and time-to-digital converter (TDC), respectively. In the first case, the difference between the start and the stop signal is converted into an analog voltage signal, which is then processed by the ADC. In the second method, the delay is directly converted into a digital signal. Systems based on ADCs generally have a better timing resolution and linearity while being expensive and the capability of being integrated. TDCs, on the other hand, can be integrated into a single chip and hence are better suited in multi-channel systems. However, they have a worse timing performance and can handle much lower sustained count-rates.
Applications
The usefulness of TD Diffuse optics lies in its ability to continually and noninvasive monitor optical properties of tissue. Making it a powerful diagnostic tool for long-term bedside monitoring in infants and adults alike. It has already been demonstrated that TD diffuse optics can be successfully applied to various biomedical applications such as cerebral monitoring, optical mammography, muscle monitoring, etc.
See also
Near-infrared spectroscopy
Functional near-infrared spectroscopy
Diffuse optical imaging
Neuroimaging
Functional neuroimaging
References
Neuroimaging
Optical imaging
Spectroscopy | Time-domain diffuse optics | [
"Physics",
"Chemistry"
] | 1,634 | [
"Instrumental analysis",
"Molecular physics",
"Spectroscopy",
"Spectrum (physical sciences)"
] |
61,194,775 | https://en.wikipedia.org/wiki/Micro-spatially%20offset%20Raman%20spectroscopy | Micro-spatially offset Raman spectroscopy (micro-SORS) is an analytical technique developed in 2014 that combines SORS with microscopy. The technique derives its sublayer‐resolving properties from its parent technique SORS. The main difference between SORS and micro-SORS is the spatial resolution: while SORS is suited to the analysis of millimetric layers, micro-SORS is able to resolve thin, micrometric-scale layers. Similarly to SORS technique, micro-SORS is able to preferentially collect the Raman photons generated under the surface in turbid (diffusely scattering) media. In this way, it is possible to reconstruct the chemical makeup of micrometric multi-layered turbid system in a non destructive way. Micro-SORS is particularly useful when dealing with precious or unique objects as for Cultural Heritage field and Forensic Science or in biomedical applications, where a non-destructive molecular characterization constitute a great advantage.
To date, micro-SORS has been mainly used to characterize biological materials such as bones, blood, and Cultural Heritage materials, especially paint stratigraphies. Other materials have been studied with this technique including polymers, industrial paper and wheat seeds.
Micro-SORS was developed on a conventional micro-Raman instrument, and portable micro-SORS prototypes are currently under further optimization to enable in-situ measurements and avoid the need of sampling.
Working principle
In turbid media, the depth‐resolving power of confocal Raman microscopy is restricted due to the optical proprieties of these materials. In such materials, Raman photons generated at different depths emerge on the surface after a certain number of scattering events. The Raman photons generated in the sub-surface emerge on the surface laterally compared to the incident light position, and this displacement is statistically proportional with the depth the Raman photon was generated at. Micro-SORS permits to preferentially collect these displaced photons coming from the sub-surface by enlarging (defocusing) or separating laser excitation and collection zones (Full micro-SORS).
Micro-SORS key-modalities
Defocusing micro-SORS
Defocusing is the most basic variant of the technique and it does not provide a complete separation between excitation and collection zones, rendering this variant less effective. Nonetheless, defocused measurements have the great advantage to be easily performed with a conventional micro-Raman without any hardware nor software modifications. Defocusing consists in the enlargement of the excitation and the collection zones that is achieved by moving the microscope objective out of focus (Δz movements) from the surface of the object or sample under analysis. The Δz movements range goes typically from few tens to two millimeters, depending on the numbers and thicknesses of the materials.
Full micro-SORS
This more sophisticated micro-SORS variant provides a complete separation of laser excitation and collection zones (Δx offset) that requires a hardware or a software modification to a conventional Raman microscope. The separation can be achieved by using an external probe or fibre optics to deliver the laser, by displacing the laser spot by moving the beam-steer alignment mirrors, by using a spatially resolved CCD, by using a digital micro-mirror device (DMD), by moving the tip of the Raman detection fibre to perform an off-confocal detection of the signal or by combining hyperspectral SORS and defocusing micro-SORS. Full micro-SORS was proven to be more effective in terms of both penetration depth into the sample and relative enhancement of sublayer signal
Layers system reconstruction
To reconstruct the micro-layer succession it is required to collect a conventional Raman spectrum and at least a one micro-SORS spectrum; the acquisition of several spectra at gradually increasing defocusing distances or spatial offsets is usually the best way to approach unknown materials. A comparison among the acquired spectra allows achieving the layers composition: in defocused of spatially offset spectra, the signals of the sub-surface layers appear or are intensified compared to the surface signal. Data treatment as spectra normalization or subtraction is commonly used to better visualize the layer sequence.
The layers' thickness can be estimated after calibration on a well characterized sample set with a known thickness.
Micro-SORS in art
Non-destructivity is a major goal for Conservation Scientist, due to the intrinsic value of Cultural Heritage objects. Micro-SORS was developed to address the need of a non-destructive analytical technique with high chemical specificity for the non-destructive analysis of thin painted layers. In painted artworks, the painted film is typically obtained superimposing turbid thin (micrometric-scale) pigmented layers, and their chemical characterization is essential to detect the presence of degradation products, to gain information about the artistic technique and for datation and authentication purposes. To date, Micro-SORS was successfully used to characterize the paint stratigraphy in polychrome sculptures, painted plasters., painted cards and contemporary street art mural paintings
References
See also
Cultural Heritage
Conservation Science
Biomedicine
Forensic Scienze
Raman Spectroscopy
Raman spectroscopy
Microscopy | Micro-spatially offset Raman spectroscopy | [
"Chemistry"
] | 1,071 | [
"Microscopy"
] |
61,195,896 | https://en.wikipedia.org/wiki/Lump%20sum%20contract | A lump sum contract in construction is one type of construction contract, sometimes referred to as stipulated-sum, where a single price is quoted for an entire project based on plans and specifications and covers the entire project and the owner knows exactly how much the work will cost in advance. This type of contract requires a full and complete set of plans and specifications and includes all the indirect costs plus the profit and the contractor will receive progress payments each month minus retention. The flexibility of this contract is very minimal and changes in design or deviation from the original plans would require a change order paid by the owner. In this contract the payment is made according to the percentage of work completed. The lump sum contract is different from guaranteed maximum price in a sense that the contractor is responsible for additional costs beyond the agreed price, however, if the final price is less than the agreed price then the contractor will gain and benefit from the savings.
There are some factors that make for a successful execution of a lump sum contract on a project such as experience and confidence, management skills, communication skills, having a clear work plan, proper list of deliverables, contingency, and dividing the responsibility among the project team.
According to Associated General Contractors of America (AGC),
With a lump sum contract or fixed-price contract, the contractor assesses the value of work as per the documents available, primarily the specifications and the drawings. At pre-tender stage the contractor evaluates the cost to execute the project (based on the above documents such as drawings, specifications, schedules, tender instruction and any clarification received in response to queries) and quotes a fixed inclusive price.
Advantages
The owner's risk is reduced due to the price of the contract being fixed and variations are not as much like other contracts.
There are fewer change orders.
The bidding and contractor selection is less complicated.
Obtaining construction loans are easier with this type of contract.
The profit margins and percentages are greater for engineers and contractors.
Payments and instalments are made on regular basis which provides the contractor with a reliable cash flow.
Management of the contract is a lot easier for the owner.
It creates an improved communication and relationship between the design team, contractor, and the owner.
Disadvantages
There is a higher risk for the contractor.
Proper change order documentation is required which could be time-consuming.
Higher fixed price due to unforeseen conditions.
The contractor selection usually takes longer.
The design has to be completed before the start of activities.
Change orders could be rejected by the owner.
It increases the adversarial relationship among the stakeholders of the project.
The contractor has a freedom to choose its own methods.
Potential for disputes between the client and the contractor, due to for example unbalanced bids, change orders, design changes, and compensation for early completion.
Variations to lump sum contracts
Variations occur due to fluctuation in prices and inflation, provisional items, statutory fees, relevant events such as failure of the owner to deliver goods, etc. Where the cost of a specific activity is identified as a "provisional sum", a variation in actual cost may be accepted by the employer.
Variations are typically broken down into two categories, beneficial and detrimental, where the former is for improvement of work quality, cost and schedule reduction, and the latter is a negative change in performance or quality of work due to client's financial difficulties. There are many reasons for variations to occur but main causes are normally due to omission in design, inadequate design, changes in specifications and scope, and lack of coordination and communication among the stakeholders.
Case law
Harvey Shopfitters Limited -v- ADI Limited (2003): Work was commenced under a Letter of Intent but a formal contract document was never completed. Harvey wanted to be paid for work on a quantum meruit basis; ADI argued that a lump sum contract had been agreed and should be enforced. The England and Wales Court of Appeal held that there was sufficient certainty in the parties' prepared agreements to establish that a lump sum contract was in place.
References
Contract law
construction | Lump sum contract | [
"Engineering"
] | 820 | [
"Construction"
] |
61,197,768 | https://en.wikipedia.org/wiki/Petroyuan | Petroyuan is a form of the official Chinese currency, the yuan intended at least initially for oil trading. On 26 March 2018, the Chinese government issued the first long term oil trading contracts denominated in petroyuans. This project exists to attempt to compete with the U.S. petrodollar as a main currency in crude oil transactions, whose hegemony has led the market since the dollar standard was first established in 1971, replacing the gold standard and giving the United States the power to manage most of the world's currency supply (around ~60%).
History
Since 1971, when U.S. President Richard Nixon ended the dollar convertibility to gold, many foreign currencies emerged trying to replicate the pre-1971 situation. An example of a petrocurrency backed by gold was a project by the Libyan leader Muammar Gaddafi, who released a project to create a multinational African currency, However, this project was discarded because he was overthrown by the United States and its allies during the 2011 military intervention in Libya.
China, with a currency constantly growing on market relevance, attempted to create a dollar alternative. In June 2017, the People's Bank of China and the Central Bank of Russia signed a memorandum to facilitate the exchange of crude oil using yuans. Months later, in September 2017, China made official the existence of the petroyuan.
The operation was given on a context where China dominated crude oil importations, with approximately 400 million tons as of 2017 as stated by Sinopec, one of China's biggest oil companies.
Characteristics
One of the reasons the petroyuan was created was that Russia, Venezuela and Iran may be able to avoid the United States' sanctions, so nations such as Saudi Arabia, one of the main oil producers and extractors could avoid dollar hegemony and U.S. pressure. The yuan's main problems are its volatile liquidity and short scale extension, however the Chinese government intervened increasing its gold reserves to back the petroyuan.
See also
Petro (token) – Venezuelan cryptocurrency
References
Petroleum economics
Petroleum politics | Petroyuan | [
"Chemistry"
] | 432 | [
"Petroleum",
"Petroleum politics"
] |
61,198,269 | https://en.wikipedia.org/wiki/OpenPsych | OpenPsych is an online collection of three pseudoscientific open access journals covering behavioral genetics, psychology, and quantitative research in sociology. Many articles on OpenPsych promote scientific racism, and the site has been described as a "pseudoscience factory-farm". The journals were started in 2014 by a pair of nonprofessional researchers, Emil Kirkegaard and Davide Piffer, who had difficulty publishing their studies in mainstream peer-reviewed scientific journals. The website describes its contents as open peer reviewed journals, but the qualifications and neutrality of its reviewers and quality of reviews have been disputed.
Founders
OpenPsych was founded by Danish white supremacist Emil Kirkegaard, the registrant of the Mankind Quarterly website. Kirkegaard has controversially pushed for the legalization of child pornography and legally changed his name to William Engman in 2021. Davide Piffer has written on remote viewing which is widely dismissed by scientists as parapsychology.
Journal contents and quality
OpenPsych consists of three journals — Open Differential Psychology, Open Behavioral Genetics, and Open Quantitative Sociology & Political Science — founded by Emil Kirkegaard and Davide Piffer in 2014. Journal contents are free to access and there is no cost associated with submission. The founders of the website believed that their articles were being regularly rejected by mainstream scientific publishers because of bias against their contentious submissions. Many of the articles are about "race realism", a form of scientific racism, and advance related views which are rejected by mainstream science, such as the idea that there is a genetic basis for group-level differences in measures such as crime and IQ. Unlike typical scientific journals, OpenPsych accepts anonymous manuscripts.
Academic reception
The quality of peer review at OpenPsych has been disputed. Reviewers do not need advanced academic qualifications, nor need to specialise in what they review. For example, Kirkegaard reviews paper submissions to two of the journals, but has only a BA in linguistics, claiming he is entirely "self-taught". Most of the reviewers are also authors of articles in the same group of journals. Of the thirteen known members of the review board in 2020, two were anonymous and eight seemed to have doctorates. Members of the review teams include Gerhard Meisenberg, Heiner Rindermann, Peter Frost, John Fuerst, Kenya Kura, Bryan J. Pesta, Noah Carl and Meng Hu.
Political positions
The journals act as a research network for far right, alt-right, and White nationalist causes, following in the footsteps of the Pioneer Fund and Mankind Quarterly; of its top 15 contributors in 2018, 11 had written for Mankind Quarterly in the preceding three years. Several members of its editorial board hold far-right political views and have attended the controversial London Conference on Intelligence. The Southern Poverty Law Center, in an article discussing proponents of scientific racism including Kirkegaard, describes OpenPsych as a "pseudojournal". Kirkegaard is regarded by the Centre for Analysis of the Radical Right to be a "figure on the radical right fringe". Landis MacKellar has described Emil Kirkegaard and John Fuerst as "both outright cranks" noting OpenPsych are "tenderly peer-reviewed online journals specializing in scientifically controversial (bordering on dubious) politically incorrect pieces derived in part from (Roger) Pearsonian hereditarianism."
Review process
Eric Turkheimer in a coauthored paper in Perspectives on Psychological Science criticises the review process of OpenPsych's journals and describes them as "pseudo-scientific vehicles for scientific racism":
Controversies
OKCupid
In May 2016, Kirkegaard and Julius Daugbjerg Bjerrekær published a paper in Open Differential Psychology that includes the data of nearly 70,000 OkCupid (a dating website) users, such as their intimate sexual details. The publication was widely criticised at the time and been described as "without a doubt one of the most grossly unprofessional, unethical and reprehensible data releases." Although Kirkegaard claimed the data was public, this was disputed by data ethics scholar Michael Zimmer who pointed out that the data is restricted to logged-in users only:
Kirkegaard uploaded the OkCupid data to the Open Science Framework, but this was later removed after OkCupid filed a Digital Millennium Copyright Act (DMCA) complaint.
Noah Carl
In April 2019, Noah Carl who reviews submissions for Open Quantitative Sociology & Political Science was dismissed as a research fellow at St Edmund's College, Cambridge University because of his association with OpenPsych, which involved collaborating with a number of individuals who are known to hold racist and far-right political views.
References
External links
2014 establishments in Denmark
Academic publishing companies
Academic journals established in 2014
Fringe science journals
Open access publishers
Publishing companies established in 2014
Race and intelligence controversy
Scientific racism | OpenPsych | [
"Biology"
] | 994 | [
"Biology theories",
"Obsolete biology theories",
"Scientific racism"
] |
61,198,684 | https://en.wikipedia.org/wiki/Irina%20Grigorieva%20%28academic%29 | Irina Grigorieva, Lady Geim is a Professor of Physics at the University of Manchester and Director of the Engineering and Physical Sciences Research Council Centre for Doctoral Training in Science and the Applications of Graphene. She was awarded the 2019 David Tabor Medal and Prize of the Institute of Physics and was elected as a Fellow of the Institute.
Early life and education
Grigorieva was born in Russia. She studied physics at the Institute of Solid State Physics in Russia and earned her PhD in 1989.
Research and career
In 1990, Grigorieva moved to Nottingham with her husband Andre Geim. She visited the University of Oxford, University of Cambridge and Imperial College London to deliver seminars on her PhD research. Eventually, she joined the University of Bristol as a postdoctoral researcher.
She moved to Nijmegen where she worked as a laboratory assistant.
Grigorieva suggested to Geim that he use a frog to demonstrate magnetic levitation, for which Geim won the Ig Nobel Prize.
She joined the University of Manchester in 2001, where she works in the Condensed Matter Physics group. When she joined the group, she started studying the adhesive mechanisms of the feet of gecko lizards. In 2003, she created a gecko-like adhesive that is self-cleaning and re-attachable. Grigorieva is a member of the Graphene Council.
Grigorieva is a Professor of Physics at the University of Manchester and Director of the Engineering and Physical Sciences Research Council Centre for Doctoral Training in Science and the Applications of Graphene. She works on the electronic and magnetic properties of two-dimensional materials. She is interested in superconducting materials and the application of graphene in spintronics. In 2013, she was the first to demonstrate that graphene could be magnetic through the use of non-magnetic atoms and vacancies. Defects in graphene carry Spin-½ magnetic moments.
In 2015, she demonstrated that it is possible to switch the magnetism in graphene on and off. She created small bubbles out of graphene and showed that they can withstand pressures of 200 megapascals, which is greater that in the deep ocean. To measure the pressure inside a graphene bubble, they used atomic force microscopy and a monolayer of boron nitride.
Grigorieva used graphene as a filter to remove subatomic particles, including taking protons from heavy water. This includes removing deuterium for the cleaning of nuclear waste.
Awards and honours
2019 Institute of Physics David Tabor Medal and Prize
Personal life
Grigorieva and husband, physicist Sir Andre Geim, have a daughter. She serves on the Board of Governors of Withington Girls' School.
References
Academics of the University of Manchester
Living people
Russian materials scientists
Russian women scientists
Women materials scientists and engineers
Year of birth missing (living people)
Wives of knights | Irina Grigorieva (academic) | [
"Materials_science",
"Technology"
] | 582 | [
"Women materials scientists and engineers",
"Materials scientists and engineers",
"Women in science and technology"
] |
61,199,339 | https://en.wikipedia.org/wiki/Lists%20of%20uniform%20tilings%20on%20the%20sphere%2C%20plane%2C%20and%20hyperbolic%20plane | In geometry, many uniform tilings on sphere, euclidean plane, and hyperbolic plane can be made by Wythoff construction within a fundamental triangle, (p q r), defined by internal angles as π/p, π/q, and π/r. Special cases are right triangles (p q 2). Uniform solutions are constructed by a single generator point with 7 positions within the fundamental triangle, the 3 corners, along the 3 edges, and the triangle interior. All vertices exist at the generator, or a reflected copy of it. Edges exist between a generator point and its image across a mirror. Up to 3 face types exist centered on the fundamental triangle corners. Right triangle domains can have as few as 1 face type, making regular forms, while general triangles have at least 2 triangle types, leading at best to a quasiregular tiling.
There are different notations for expressing these uniform solutions, Wythoff symbol, Coxeter diagram, and Coxeter's t-notation.
Simple tiles are generated by Möbius triangles with whole numbers p,q,r, while Schwarz triangles allow rational numbers p,q,r and allow star polygon faces, and have overlapping elements.
7 generator points
The seven generator points with each set of (and a few special forms):
There are three special cases:
– This is a mixture of and , containing only the faces shared by both.
– Snub forms (alternated) are given by this otherwise unused symbol.
– A unique snub form for U75 that isn't Wythoff-constructible.
Symmetry triangles
There are 4 symmetry classes of reflection on the sphere, and three in the Euclidean plane. A few of the infinitely many such patterns in the hyperbolic plane are also listed. (Increasing any of the numbers defining a hyperbolic or Euclidean tiling makes another hyperbolic tiling.)
Point groups:
(p 2 2) dihedral symmetry, (order )
(3 3 2) tetrahedral symmetry (order 24)
(4 3 2) octahedral symmetry (order 48)
(5 3 2) icosahedral symmetry (order 120)
Euclidean (affine) groups:
(4 4 2) *442 symmetry: 45°-45°-90° triangle
(6 3 2) *632 symmetry: 30°-60°-90° triangle
(3 3 3) *333 symmetry: 60°-60°-60° triangle
Hyperbolic groups:
(7 3 2) *732 symmetry
(8 3 2) *832 symmetry
(4 3 3) *433 symmetry
(4 4 3) *443 symmetry
(4 4 4) *444 symmetry
(5 4 2) *542 symmetry
(6 4 2) *642 symmetry
...
The above symmetry groups only include the integer solutions on the sphere. The list of Schwarz triangles includes rational numbers, and determine the full set of solutions of nonconvex uniform polyhedra.
In the tilings above, each triangle is a fundamental domain, colored by even and odd reflections.
Summary spherical, Euclidean and hyperbolic tilings
Selected tilings created by the Wythoff construction are given below.
Spherical tilings (r = 2)
Some overlapping spherical tilings (r = 2)
Tilings are shown as polyhedra. Some of the forms are degenerate, given with brackets for vertex figures, with overlapping edges or vertices.
Dihedral symmetry (q = r = 2)
Spherical tilings with dihedral symmetry exist for all many with digon faces which become degenerate polyhedra. Two of the eight forms (Rectified and cantillated) are replications and are skipped in the table.
Euclidean and hyperbolic tilings (r = 2)
Some representative hyperbolic tilings are given, and shown as a Poincaré disk projection.
Euclidean and hyperbolic tilings (r > 2)
The Coxeter–Dynkin diagram is given in a linear form, although it is actually a triangle, with the trailing segment r connecting to the first node.
See also
Regular polytope
Regular polyhedron
List of uniform tilings
Uniform tilings in hyperbolic plane
List of uniform polyhedra
List of uniform polyhedra by Schwarz triangle
References
Coxeter Regular Polytopes, Third edition, (1973), Dover edition, (Chapter V: The Kaleidoscope, Section: 5.7 Wythoff's construction)
Coxeter The Beauty of Geometry: Twelve Essays, Dover Publications, 1999, (Chapter 3: Wythoff's Construction for Uniform Polytopes)
Coxeter, Longuet-Higgins, Miller, Uniform polyhedra, Phil. Trans. 1954, 246 A, 401–50.
pp. 9–10.
External links
The Wythoff symbol
Greg Egan's applet to display uniform polyhedra using Wythoff's construction method
A Shadertoy renderization of Wythoff's construction method
KaleidoTile 3 Free educational software for Windows by Jeffrey Weeks that generated many of the images on the page.
Polyhedra
Uniform polytopes
Mathematical notation | Lists of uniform tilings on the sphere, plane, and hyperbolic plane | [
"Physics",
"Mathematics"
] | 1,048 | [
"Uniform polytopes",
"nan",
"Symmetry"
] |
61,200,236 | https://en.wikipedia.org/wiki/C6H13Br | {{DISPLAYTITLE:C6H13Br}}
The molecular formula C6H13Br (molar mass: 165.07 g/mol, exact mass: 164.0201 u) may refer to:
1-Bromohexane
2-Bromohexane | C6H13Br | [
"Chemistry"
] | 63 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,200,396 | https://en.wikipedia.org/wiki/C22H25N3O2 | {{DISPLAYTITLE:C22H25N3O2}}
The molecular formula C22H25N3O2 may refer to:
Baxdrostat
Bucindolol | C22H25N3O2 | [
"Chemistry"
] | 43 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,200,720 | https://en.wikipedia.org/wiki/El%20Paso%20and%20Southwestern%20Railway%20Water%20Supply%20System | The El Paso and Southwestern Railway Water Supply System, in the area south of Nogal, New Mexico, was built in 1908. It was listed on the National Register of Historic Places in 1979.
It is also named, or it includes, the Bonito Pipeline. The construction engineer was Charles H. Henning.
References
Water supply
National Register of Historic Places in Lincoln County, New Mexico
Buildings and structures completed in 1908
Water Supply System | El Paso and Southwestern Railway Water Supply System | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 88 | [
"Hydrology",
"Water supply",
"Environmental engineering"
] |
61,202,555 | https://en.wikipedia.org/wiki/%CE%91-Eucaine | α-Eucaine (alpha-eucaine) is a drug that was previously used as a local anesthetic. It was designed as an analog of cocaine and was one of the first synthetic chemical compounds to find general use as an anesthetic.
Synthesis
The Aldol condensation between two equivalents of acetone gives Mesityl oxide [141-79-7] (1) (isophorone is a side-product of this reaction). Ammonolysis of mesityl oxide formed diacetonamine [625-04-7] (2). The reaction of this product with acetone then gives 2,2,6,6-tetramethyl-4-piperidone [826-36-8] (3). N-methylation of the secondary amine gives 1,2,2,6,6-pentamethylpiperidin-4-one [5554-54-1] (4). Cyanohydrin formation gives CID:434556 (5). Esterification of the tertiary alcohol with benzoyl chloride gives (6). Pinner reaction of the nitrile with EtOH/H+ affords alpha-eucaine (7).
See also
Eucaine, or β-eucaine, a related local anesthetic
References
Local anesthetics
Piperidines
Benzoate esters
Methyl esters | Α-Eucaine | [
"Chemistry"
] | 301 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
56,364,964 | https://en.wikipedia.org/wiki/7%20Draconis | 7 Draconis, also named Tianyi , is a single star in the northern circumpolar constellation of Draco. It is visible to the naked eye as a faint orange-hued star with a stellar classification of 5.43. Based upon an annual parallax shift of as seen from the Earth, the star is located approximately 780 light-years from the Sun.
This is an evolved giant star with a stellar classification of K5 III. The measured angular diameter of this star, after correction for limb darkening, is . At its estimated distance, this yields a physical size of about 67 times the radius of the Sun. It is radiating about 1,024 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,945 K.
Nomenclature
7 Draconis is the star's Flamsteed designation.
The star bore the traditional Chinese name of Tianyi, from 天乙 (Tiān Yǐ) or 天一 (Tiān Yī, the Celestial Great One), a deity in Taoism. In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name Tianyi for this star on 30 June 2017 and it is now so entered on the List of IAU-approved Star Names.
References
K-type giants
Draco (constellation)
Draconis, 07
111335
62423
4863
Tianyi | 7 Draconis | [
"Astronomy"
] | 305 | [
"Constellations",
"Draco (constellation)"
] |
56,365,055 | https://en.wikipedia.org/wiki/Debasisa%20Mohanty | Debasisa Mohanty (born 30 November 1966) is an Indian computational biologist, bioinformatician and a staff scientists at the National Institute of Immunology, India. Known for his studies on structure and function prediction of proteins, genome analysis and computer simulation of biomolecular systems, Mohanty is an elected fellow of all the three major Indian science academies namely the Indian Academy of Sciences, the Indian National Science Academy and the National Academy of Sciences, India. The Department of Biotechnology of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards, for his contributions to biosciences, in 2009.
Biography
Born on 30 November 1966, Debasisa Mohanty earned a post graduate degree (MSc) in physics from the Indian Institute of Technology, Kanpur in 1988 and did his doctoral studies at the Molecular Biophysics Unit of the Indian Institute of Science to secure a PhD in computational biophysics in 1994. Subsequently, he completed his post-doctoral work, first the Hebrew University of Jerusalem and, later, at the Scripps Research Institute. On his return to India, he joined the National Institute of Immunology, India (NII) where he serves as a Grade VII staff scientist and hosts a number of research scholars at his laboratory. He currently hold director position at NII. At NII, he also supervises the activities of RiPPMiner, (Bioinformatics Resource for Deciphering Chemical Structures of RiPPs) and the Bioinformatics Centre.
Mohanty resides at the NII Campus, along Aruna Asaf Ali Marg in New Delhi.
Legacy
Mohanty's research focus is in the fields of computational biology and bioinformatics and he is known to have developed computational methods for predicting the substrate specificity of proteins as well as identified biosynthetic pathways. His work has assisted in widening the understanding of the function of putative proteins in genomes and the protein interaction networks in newly sequenced genomes. His studies have been documented by way of a number of articles and ResearchGate, an online repository of scientific articles has listed 108 of them.
Mohanty was a member of the national organizing committee of the International Conference in Bioinformatics (INCOB) held in 2006 in India
and has delivered invited speeches at various conferences which included the seminar series on Proteomics and bioinformatics of the Regional Centre for Biotechnology held in 2013, the Symposium on Accelerating Biology 2017: Delivering Precision of the Centre for Development of Advanced Computing (C-DAC) held in January 2017 in Pune, and the Symposium on Functional Genomics organized by the Indraprastha Institute of Information Technology in Delhi in December 2017.
Awards and honors
Mohanty received the Samanta Chandrashekhar Award of the Orissa Bigyan Academy in 2005 and the Rajib Goyal Young Scientist Prize in Life Sciences of Kurukshetra University in 2007. The National Academy of Sciences, India elected him as a fellow the next year and the Department of Biotechnology (DBT) of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards in 2009. He became an elected fellow of the Indian Academy of Sciences in 2012 and of the Indian National Science Academy in 2013.
Selected bibliography
See also
Protein–protein interaction
In silico
Notes
References
Further reading
External links
N-BIOS Prize recipients
Living people
20th-century Indian biologists
Computational biology
Indian bioinformaticians
IIT Kanpur alumni
Indian Institute of Science alumni
Scripps Research alumni
Hebrew University of Jerusalem alumni
1966 births
Scientists from Delhi | Debasisa Mohanty | [
"Biology"
] | 741 | [
"Computational biology"
] |
56,367,582 | https://en.wikipedia.org/wiki/ACS%20Mersin | ACS Mersin is a glass factory in Mersin, Turkey. ACS stands for Anadolu Cam Sanayii ("Anatolian Glass Industry")
The factory is at in Yenitaşkent neighborhood to the north of the Turkish state highway which connects Mersin to Tarsus. Its distance to Mersin is about .
The factory was put into operation in 1969. In 1975, it was acquired by Şişecam Group of Companies. In 1988, NNPB (narrow neck press and blow) technology was successfully used for the first time in Turkey at ACS. Current annual glass production is 260 822 metric tons. The number of employees is 461. But after the planned instauration the annual production will rise to 366685 metric tons and the number of employees will increase to 483.
References
Buildings and structures in Mersin Province
Glassmaking companies
Akdeniz District
Industrial buildings in Turkey
Industrial buildings completed in 1975
Companies based in Mersin
Turkish brands
Turkish companies established in 1969
Manufacturing companies established in 1969 | ACS Mersin | [
"Materials_science",
"Engineering"
] | 208 | [
"Glass engineering and science",
"Glassmaking companies",
"Engineering companies"
] |
56,367,698 | https://en.wikipedia.org/wiki/Kepler-277b | Kepler-277b (also known by its Kepler Objects of Interest designation KOI-1215.01) is the second most massive and third-largest rocky planet ever discovered, with a mass close to that of Saturn. Discovered in 2014 by the Kepler Space Telescope, Kepler-277b is a sub-Neptune sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock and iron. Along with its sister planet, Kepler-277c, the planet's mass was determined using transit-timing variations (TTVs).
Characteristics
Size and temperature
Kepler-277b was detected using the transit method and TTVs, allowing for both its mass and radius to be determined to some level. It is approximately 2.92 , between the size of Earth and Neptune. At that radius, most planets should be gaseous Mini-Neptunes with no solid surface. However, the mass of Kepler-277b is extremely high for its size. Transit-timing variations indicate a planetary mass of about 87.3 , comparable to Saturn's mass at 95.16 . The planet has a density of approximately 19.3 g/cm3 and about 10.4 times the surface gravity of Earth. Such a high density for an object of this size implies that, like its sister planet, Kepler-277b is an enormous rock-based planet. It is currently the second most massive and third largest terrestrial planet ever discovered, behind Kepler-277c in radius and PSR J1719−1438 b in both radius and mass. Due to its proximity to its host star, Kepler-277b is quite hot with an equilibrium temperature of about , hot enough to melt certain metals.
Internal structure and composition
Models of Kepler-277b's internal structure suggest that it has a very large iron core with an estimated radius of 2.435 . The core predominantly consists of an allotrope of iron with a face-centered cubic (FCC) crystalline structure. At the innermost region of Kepler-277b's core where pressures reach as high as 37.52 terapascals, iron exists in a body-centered-tetragonal (BCT) and body-centered cubic (BCC) crystalline structure.
Kepler-277b has a relatively thin silicate mantle in comparison to its core. The mantle of Kepler-277b is thought be predominantly composed of ultrahigh-pressure phases of magnesium silicates (MgSiO3). The uppermost mantle of Kepler-277b is thought to consist of olivine, wadsleyite, and ringwoodite while the lower part of Kepler-277b's upper mantle consists of silicate perovskite and post-perovskite.
Orbit
Kepler-277b orbits close to its host star, with one orbit lasting 17.324 days. Its semi-major axis, or average distance from the parent object, is about 0.136 AU. For comparison, the planet Mercury in the Solar System takes 88 days to orbit at a distance of 0.38 AU. At this distance, Kepler-277b is very hot and most likely tidally locked to its host star. It is close to a 2:1 resonance with Kepler-277c, which orbits at an average distance of about 0.209 AU.
Host star
The parent star Kepler-277 is a large yellow star. It is 1.69 and 1.12 , with a temperature of 5946 K, a metallicity of -0.315 [Fe/H], and an unknown age. For comparison, the Sun has a temperature of 5778 K, a metallicity of 0.00 [Fe/H], and an age of about 4.5 billion years. The large radius in comparison to its mass and temperature suggest that Kepler-277 could be a Subgiant star.
See also
Mega-Earth
Kepler-277c
References
Exoplanets discovered in 2014
Exoplanets discovered by the Kepler space telescope
Transiting exoplanets
Lyra
Mega-Earths | Kepler-277b | [
"Astronomy"
] | 835 | [
"Lyra",
"Constellations"
] |
56,367,760 | https://en.wikipedia.org/wiki/Kepler-277c | Kepler-277c (also known by its Kepler Objects of Interest designation KOI-1215.02) is the third most massive and second-largest rocky planet ever discovered, with a mass about 64 times that of Earth. Discovered in 2014 by the Kepler Space Telescope, Kepler-277c is a Neptune-sized exoplanet with a very high mass and density for an object of its radius, suggesting a composition made mainly of rock with some amounts of water. Along with its sister planet, Kepler-277b, the planet's mass was determined using transit-timing variations (TTVs).
Characteristics
Size and temperature
Kepler-277c was detected using the transit method and TTVs, allowing for both its mass and radius to be determined to some level. It is approximately 3.36 , close to the size of Neptune. At that radius, most planets should be gaseous Mini-Neptunes with no solid surface. However, the mass of Kepler-277c is extremely high for its size. Transit-timing variations indicate a planetary mass of about 64.2 , close to Saturn's mass at 95.16 . The planet has a density of approximately 9.33 g/cm3 and about 5.7 times the surface gravity of Earth. Such a high density for an object of this size implies that, like its sister planet, Kepler-277c is an enormous rock-based planet with a small portion of its mass as water. It is currently the third most massive and second largest terrestrial planet ever discovered, behind Kepler-277b in mass and PSR J1719-1438 b in both radius and mass. Due to its proximity to its host star, Kepler-277c is quite hot with an equilibrium temperature of about , hot enough to melt certain metals.
Orbit
Kepler-277c orbits close to its host star, with one orbit lasting 33.006 days. Its semi-major axis, or average distance from the parent object, is about 0.209 AU. For comparison, the planet Mercury takes 88 days to orbit the Sun at a distance of 0.38 AU. At this distance, Kepler-277c is very hot and most likely tidally locked to its host star. It is close to a 1:2 resonance with Kepler-277b, which orbits at an average distance of about 0.136 AU.
Host star
The parent star Kepler-277 is a large yellow star. It is 1.69 and 1.12 , with a temperature of 5946 K, a metallicity of -0.315 [Fe/H], and an unknown age. For comparison, the Sun has a temperature of 5778 K, a metallicity of 0.00 [Fe/H], and an age of about 4.5 billion years. The large radius in comparison to its mass and temperature suggest that Kepler-277 could be a Subgiant star.
See also
Mega-Earth
Kepler-277b
References
Exoplanets discovered in 2014
Transiting exoplanets
Exoplanets discovered by the Kepler space telescope
Lyra
Mega-Earths | Kepler-277c | [
"Astronomy"
] | 630 | [
"Lyra",
"Constellations"
] |
56,367,992 | https://en.wikipedia.org/wiki/1%2C1%2C3%2C3-Tetramethoxypropane | 1,1,3,3-Tetramethoxypropane is an organic compound with the formula CH(CH(OCH)). A colorless liquid, it is a protected form of malondialdehyde, a usefully reactive reagent that has poor storage properties.
References
Acetals
Protecting groups | 1,1,3,3-Tetramethoxypropane | [
"Chemistry"
] | 69 | [
"Acetals",
"Protecting groups",
"Functional groups",
"Reagents for organic chemistry"
] |
56,369,081 | https://en.wikipedia.org/wiki/C/2016%20R2%20%28PanSTARRS%29 | C/2016 R2 (PanSTARRS) is a comet, discovered using the Pan-STARRS telescopes on September 7, 2016. The comet attracted attention from many astronomers as it approached its closest point to the Sun in May 2018. It has been observed to have a very complex tail, which has been suggested to be due to a fast rotation period of the nucleus.
The comet orbits the Sun on a 20,000 year orbit, which takes it out about 740 AU. It was found to differ from typical comets, and was found to be rich in carbon monoxide (CO) but depleted in hydrogen cyanide (HCN), resulting in a blue coma. The blue color is thought to come from the rich amounts of carbon monoxide being ionized. The comet was also noted to be rich in nitrogen.
The comet was observed by a submillimeter wavelength telescope in the late 2010s.
The comet made its closest approach to the Sun in May 2018, and its blue, teal, and dust tail were noted as an astronomical target. Blue comets are a less common type of comet.
Gallery
See also
2I/Borisov
C/1908 R1 (Morehouse)
C/1961 R1 (Humason)
References
External links
Comet C/2016 R2 (PanSTARRS) Information | TheSkyLive.com
Non-periodic comets
Oort cloud
Comets in 2016
20160907
Discoveries by Pan-STARRS | C/2016 R2 (PanSTARRS) | [
"Astronomy"
] | 293 | [
"Astronomical hypotheses",
"Oort cloud",
"Astronomy stubs",
"Comet stubs"
] |
56,369,319 | https://en.wikipedia.org/wiki/64%20Piscium | 64 Piscium is the Flamsteed designation for a close binary star system in the zodiac constellation of Pisces. It can be viewed with the naked eye, with the components having a combined apparent visual magnitude of 5.07. An annual parallax shift of 42.64 mas provides a distance estimate of 46.5 light years. The system is moving further from the Sun with a radial velocity of +3.76 km/s.
This is a double-lined spectroscopic binary system consisting of two similar components designated Aa and Ab. The initial orbital elements were determined by Abt and Levy (1976), giving an orbital period of 13.8 days. In Boden et al. (1999), the full set of orbital elements were derived using measurements with the Palomar Testbed Interferometer. Nadal et al. (1979) suggested that some variation in the measurements may be caused by a third component in the system, but this was not supported by the results from Boden et al. (1999). In 2005, Maciej Konacki pioneered a new technique for accurately determining the radial velocity of a double-lined binary system, which allowed the elements to be further refined. This yielded an orbital period of 13.82449 days, an eccentricity of 0.2366, and an angular semimajor axis of 6.55 mas.
Both stars in this system have a spectrum matching a stellar classification of F8 V, indicating they are ordinary F-type main-sequence stars that are generating energy via hydrogen fusion at their cores. The orbital measurements of this system allows the masses of the two stars to be determined accurately: the primary component has 1.22 times the mass of the Sun while the secondary has 1.17 times the Sun's mass. Both stars are larger and brighter than the Sun, with higher temperature photospheres − having effective temperatures of around 6,200 K compared to 5,772 K for the Sun. The age of the system is estimated as 6.8 billion years and they have a similar element abundance as the Sun.
In 2010, the system was identified as a debris disk candidate based upon the detection of an infrared excess at a wavelength of 24 μm. This dust has a mean temperature of 300 K and is orbiting at a radius of 1.7 AU, compared to a projected linear separation of 0.23 AU for the components.
The Washington Double Star Catalog lists two additional visual components. Component B is a magnitude 12.6 star at an angular separation of 77 arcseconds from the primary system. Component C is magnitude 13.0 and is located 71 arcseconds away. It is unknown if either is gravitationally bound to 64 Piscium Aab, but if they are then the projected separations are about 1,800 AU with an orbital period of around 50,000 years.
References
F-type main-sequence stars
Spectroscopic binaries
Pisces (constellation)
Durchmusterung objects
Piscium, 064
004676
003810
0225 | 64 Piscium | [
"Astronomy"
] | 630 | [
"Pisces (constellation)",
"Constellations"
] |
56,369,610 | https://en.wikipedia.org/wiki/Dithiolium%20salt | Dithiolium salts are compounds of the formula [(RC)3S2]+X− (R = H, alkyl, aryl, etc.). These salts consist of a planar organic cation with a variety of anions such as halides. The five-membered ring cations are observed in either of two isomers, 1,2- and 1,3-dithiolium cations. These cations differ with respect to the relative positions of the pair of sulfur atoms. Both isomers feature a planar ring, which is aromatic owing to the presence of 6π electrons. For example, the 1,2-ditholium ring can be represented as an allyl cation of the three carbons, with each sulfur atom donating one of its lone pairs of electrons to give a total of three pairs.
Preparation, occurrence, reactions
1,2-Dithiolium cations have been prepared from 1,3-diketones by treatment with H2S and oxidants such as bromine.
1,3-Dithiolium cations are often prepared by alkylation of the corresponding unsaturated dithio- or trithiocarbonates:
The analogous reaction of electrophiles with 1,2-dithiole-2-ones affords 1,2-dithiolium cations.
References
Organosulfur compounds
Aromatic compounds | Dithiolium salt | [
"Chemistry"
] | 297 | [
"Organic compounds",
"Aromatic compounds",
"Organosulfur compounds"
] |
56,371,096 | https://en.wikipedia.org/wiki/Sheaf%20of%20algebras | In algebraic geometry, a sheaf of algebras on a ringed space X is a sheaf of commutative rings on X that is also a sheaf of -modules. It is quasi-coherent if it is so as a module.
When X is a scheme, just like a ring, one can take the global Spec of a quasi-coherent sheaf of algebras: this results in the contravariant functor from the category of quasi-coherent (sheaves of) -algebras on X to the category of schemes that are affine over X (defined below). Moreover, it is an equivalence: the quasi-inverse is given by sending an affine morphism to
Affine morphism
A morphism of schemes is called affine if has an open affine cover 's such that are affine. For example, a finite morphism is affine. An affine morphism is quasi-compact and separated; in particular, the direct image of a quasi-coherent sheaf along an affine morphism is quasi-coherent.
The base change of an affine morphism is affine.
Let be an affine morphism between schemes and a locally ringed space together with a map . Then the natural map between the sets:
is bijective.
Examples
Let be the normalization of an algebraic variety X. Then, since f is finite, is quasi-coherent and .
Let be a locally free sheaf of finite rank on a scheme X. Then is a quasi-coherent -algebra and is the associated vector bundle over X (called the total space of .)
More generally, if F is a coherent sheaf on X, then one still has , usually called the abelian hull of F; see Cone (algebraic geometry)#Examples.
The formation of direct images
Given a ringed space S, there is the category of pairs consisting of a ringed space morphism and an -module . Then the formation of direct images determines the contravariant functor from to the category of pairs consisting of an -algebra A and an A-module M that sends each pair to the pair .
Now assume S is a scheme and then let be the subcategory consisting of pairs such that is an affine morphism between schemes and a quasi-coherent sheaf on . Then the above functor determines the equivalence between and the category of pairs consisting of an -algebra A and a quasi-coherent -module .
The above equivalence can be used (among other things) to do the following construction. As before, given a scheme S, let A be a quasi-coherent -algebra and then take its global Spec: . Then, for each quasi-coherent A-module M, there is a corresponding quasi-coherent -module such that called the sheaf associated to M. Put in another way, determines an equivalence between the category of quasi-coherent -modules and the quasi-coherent -modules.
See also
quasi-affine morphism
Serre's theorem on affineness
References
External links
https://ncatlab.org/nlab/show/affine+morphism
Sheaf theory
Morphisms of schemes | Sheaf of algebras | [
"Mathematics"
] | 659 | [
"Topology",
"Sheaf theory",
"Mathematical structures",
"Category theory"
] |
56,373,609 | https://en.wikipedia.org/wiki/Soda%20Industry%20Inc. | Soda Industry Inc. (, also called Sodakrom) is a chemical company in Mersin, Turkey producing soda ash and chromium compounds mainly for the glass industry in its parent's group of companies. It is owned and operated by the Şişecam Group.
The soda plant at is to the west of Kazanlı neighborhood in Akdeniz district of Mersin, southern Turkey.
History
The Soda Industry Inc. was established in 1969 as a subsidiary of the Şişecam Group, Turkey's major glass producer. Production of soda ash (sodium carbonate, Na2CO3), a key raw material for the glass industry, began in 1975.
In 1979, the Kromsan Chromium Compounds Plant () was founded. It is situated just to the northwest of the Soda Plant. In 1982, it joined the Şişecam Chemicals Group, one of the four main businesses of Şişecam Group. In 1986, Kromsan merged with the Soda Industry company.
Beginning by 1997, Soda Industry began foreign investments. Soda Industry acquired 25% share of the Bulgarian Soda factory Sodi in 1997 and all shares of the Bosnian soda factory Lukavac in 2006 to increase its soda production. In 2011 Soda Industry also acquired the Italian Chromium Products factory Cromital .
The Soda Plant and the Kromsan Chromium Compounds Plant produce chemicals, which are used in a variety of industrial and consumer goods such as detergents, leather and pharmaceuticals.
Production
Soda Industry now is the leading producer of chromium compounds and the 4th greatest producer of sodium compounds (such as sodium dichromate (), basic chromium sulfate ([Cr2(H2O)6()4]) and chromic acid (H2CrO4 ) with an annual production of 2.2 million metric tons in Europe. Vitamin K3 and sodium metabisulphite are among the other products.
References
Buildings and structures in Mersin
Akdeniz District
Chemical industry
Chromium compounds
Industrial buildings in Turkey
Companies based in Mersin
Chemical companies established in 1979
Chemical companies established in 1969
Turkish companies established in 1979
Turkish companies established in 1969 | Soda Industry Inc. | [
"Chemistry"
] | 440 | [
"nan"
] |
56,374,292 | https://en.wikipedia.org/wiki/Type%20theory%20with%20records | Type theory with records is a formal semantics representation framework, using records to express type theory types. It has been used in natural language processing, principally computational semantics and dialogue systems.
Syntax
A record type is a set of fields. A field is a pair consisting of a label and a type. Within a record type, field labels are unique. The witness of a record type is a record. A record is a similar set of fields, but fields contain objects instead of types. The object in each field must be of the type declared in the corresponding field in the record type.
Basic type:
Object:
Ptype:
Object:
where and are individuals (type ), is proof that is a boy, etc.
References
Type theory
Semantics | Type theory with records | [
"Mathematics"
] | 148 | [
"Type theory",
"Mathematical logic",
"Mathematical structures",
"Mathematical objects"
] |
56,375,520 | https://en.wikipedia.org/wiki/SWISS%20TXT | SWISS TXT (SWISS TXT Corporation) (until December 2015: SWISS TXT Schweizerische Teletext AG) is a subsidiary and the centre of multimedia expertise of the Swiss Broadcasting Corporation.
History
The company was founded on 23 December 1983 with a licence granted by the Swiss Federal Council Teletext Licence.
The Teletext service started operations on SF DRS in 1984, on TSR in 1985 and on TSI in 1986.
In 2001, the number of daily viewers reached a record of 1.17 million. In 2004, that number reached 1.3 million a day.
Until 2015, SWISS TXT was responsible for the development, operation and commercialization of the Teletext service on television channels operated by the Swiss Broadcasting Corporation. Between 2005 and 2008, the Teletext editorial department was integrated into Swiss Broadcasting Corporation television channels SRF 1, SRF zwei, RTS Un, RTS Deux, RSI La 1, RSI La 2 operations.
The multimedia sector was expanded in 2009. With the strategic reorientation on 1 January 2016, SWISS TXT operates in multimedia for the Swiss Broadcasting Corporation and on the third-party market.
Organisation
SWISS TXT has its headquarters in Biel/Bienne and branch offices in Zürich, Bern, Geneva, Lausanne and Comano.
Access Services (subtitling, transcription, translation, audio description, speech-to-text)
SWISS TXT subtitles the Swiss Broadcasting Corporation television programmes. It also provides transcription, translation and audio description services.
Further services as a multimedia provider
Software-as-a-Service (SaaS): Media Cloud, mediahub and video delivery platforms VDP/Kaltura.
Infrastructure-as-a-Service (IaaS): Storage, content delivery network CDN, livestreaming.
Platforms-as-a-Service (PaaS): Docker, Kubernetes.
Hybrid Broadband Broadcast TV (HbbTV): Interactive television.
Multi-device-solutions for sport: multimedia platforms
Consulting: Advice on video strategy.
References
External links
Official website of the company
1983 establishments in Switzerland
Mass media companies of Switzerland
Multimedia
Teletext
Swiss Broadcasting Corporation
Companies based in the canton of Bern | SWISS TXT | [
"Technology"
] | 451 | [
"Multimedia"
] |
64,674,054 | https://en.wikipedia.org/wiki/Nepal%20Engineers%20Association | Nepal Engineers' Association (NEA) (Nepali:नेपाल ईन्जिनियर्स एसोसियसन) is an independent non-profit organization of engineers of Nepal. Its headquarters is located in Pulchowk, Lalitpur. It was established in 1962. It has the provincial committee in each province of Nepal.
Objectives
It has the following objectives:
promote the development of the engineering science and technology
promote fellowship and safeguard their rights and interests of engineers
enhance participation of the national engineering manpower for national development activities
develop relations, fellowship and goodwill with international engineering associations and institutions.
Activities
NEA celebrates its annual Engineers' day on Shrawan 3.
Veteran engineers are facilitated with lifetime achievement awards and young and upcoming fellow engineers are recognized at the event. Apart for the annual event, NEA also holds international conventions every two years.
Training and rapid response in disaster management.
Members
Year 2022: 36,500 plus members
International centers
NEA Qatar, established 2004
Australia
Thailand
United Kingdom
Japan
External links
Official website
See also
Nepal Engineering Council
References
Scientific organisations based in Nepal
Professional associations based in Nepal
1962 establishments in Nepal
Engineering organizations in Nepal | Nepal Engineers Association | [
"Engineering"
] | 230 | [
"Engineering organizations in Nepal"
] |
64,674,233 | https://en.wikipedia.org/wiki/HD%2074423 | HD 74423 is a heartbeat binary star and one component pulsates on only one hemisphere. This is caused by tidal interaction with its partner. The star is located in the Volans constellation.
HD 74423 is slightly variable in brightness. It fluctuates between magnitudes 8.58 and 8.66 every 19 hours. The exact variability type is unclear. It was initially found in a search for α2 Canum Venaticorum variables and assumed to be one, but has since been considered to be a δ Scuti variable. The spectrum shows unusually strong absorption lines of some iron peak elements, a characteristic of λ Boötis stars. Both components are thought to show the chemical peculiarity.
References
External links
Press release
Volans
074423
Lambda Boötis stars
A-type main-sequence stars
Durchmusterung objects
Delta Scuti variables
Alpha2 Canum Venaticorum variables
Rotating ellipsoidal variables | HD 74423 | [
"Astronomy"
] | 192 | [
"Volans",
"Constellations"
] |
64,675,441 | https://en.wikipedia.org/wiki/Graph%20homology | In algebraic topology and graph theory, graph homology describes the homology groups of a graph, where the graph is considered as a topological space. It formalizes the idea of the number of "holes" in the graph. It is a special case of a simplicial homology, as a graph is a special case of a simplicial complex. Since a finite graph is a 1-complex (i.e., its 'faces' are the vertices - which are 0-dimensional, and the edges - which are 1-dimensional), the only non-trivial homology groups are the 0-th group and the 1-th group.
The 1st homology group
The general formula for the 1st homology group of a topological space X is: The example below explains these symbols and concepts in full detail on a graph.
Example
Let X be a directed graph with 3 vertices {x,y,z} and 4 edges {a: x→y, b: y→z, c: z→x, d: z→x}. It has several cycles:
One cycle is represented by the loop a+b+c. Here, the plus sign represents the fact that all edges are travelled at the same direction. Since the addition operation is commutative, the + sign represents the fact that the loops a+b+c, b+c+a, and c+a+b, all represent the same cycle.
A second cycle is represented by the loop a+b+d.
A third cycle is represented by the loop c−d. Here, the minus sign represents the fact that the edge d is travelled backwards.
If we cut the plane along the loop a+b+d, and then cut at c and "glue" at d, we get a cut along the loop a+b+c. This can be represented by the following relation: (a+b+d) + (c-d) = (a+b+c). To formally define this relation, we define the following commutative groups:
C0 is the free abelian group generated by the set of vertices {x,y,z}. Each element of C0 is called a 0-dimensional chain.
C1 is the free abelian group generated by the set of directed edges {a,b,c,d}. Each element of C1 is called a 1-dimensional chain. The three cycles mentioned above are 1-dimensional chains, and indeed the relation (a+b+d) + (c-d) = (a+b+c) holds in the group C1.
Most elements of C1 are not cycles, for example a+b, 2a+5b-c, etc. are not cycles. To formally define a cycle, we first define boundaries. The boundary of an edge is denoted by the operator and defined as its target minus its source, so So is a mapping from the group C1 to the group C0. Since a,b,c,d are the generators of C1, this naturally extends to a group homomorphism from C1 to C0. In this homomorphism, . Similarly, maps any cycle in C1 to the zero element of C0. In other words, the set of cycles in C1 generates the null space (the kernel) of . In this case, the kernel of has two generators: one corresponds to a+b+c and the other to a+b+d (the third cycle, c-d, is a linear combination of the first two). So is isomorphic to Z2.
In a general topological space, we would define higher-dimensional chains. In particular, C2 would be the free abelian group on the set of 2-dimensional objects. However, in a graph there are no such objects, so C2 is a trivial group. Therefore, the image of the second boundary operator, , is trivial too. Therefore: This corresponds to the intuitive fact that the graph has two "holes". The exponent is the number of holes.
General case
The above example can be generalized to an arbitrary connected graph G = (V, E). Let T be a spanning tree of G. Every edge in E \ T corresponds to a cycle; these are exactly the linearly independent cycles. Therefore, the first homology group H1 of a graph is the free abelian group with |E \ T| generators. This number equals |E|-|V|+1; so:In a disconnected graph, when C is the set of connected components, a similar computation shows:In particular, the first group is trivial if and only if X is a forest.
The 0-th homology group
The general formula for the 0-th homology group of a topological space X is:
Example
We return to the graph with 3 vertices {x,y,z} and 4 edges {a: x→y, b: y→z, c: z→x, d: z→x}. Recall that the group C0 is generated by the set of vertices. Since there are no (−1)-dimensional elements, the group C−1 is trivial, and so the entire group C0 is a kernel of the corresponding boundary operator: = the free abelian group generated by {x,y,z}.
The image of contains an element for each pair of vertices that are boundaries of an edge, i.e., it is generated by the differences {y−x, z−y, x−z}. To calculate the quotient group, it is convenient to think of all the elements of as "equivalent to zero". This means that x, y and z are equivalent - they are in the same equivalence class of the quotient. In other words, is generated by a single element (any vertex can generate it). So it is isomorphic to Z.
General case
The above example can be generalized to any connected graph. Starting from any vertex, it is possible to get to any other vertex by adding to it one or more expressions corresponding to edges (e.g. starting from x, one can get to z by adding y-x and z-y). Since the elements of are all equivalent to zero, it means that all vertices of the graph are in a single equivalence class, and therefore is isomorphic to Z.
In general, the graph can have several connected components. Let C be the set of components. Then, every connected component is an equivalence class in the quotient group. Therefore: It can be generated by any |C|-tuple of vertices, one from each component.
Reduced homology
Often, it is convenient to assume that the 0-th homology of a connected graph is trivial (so that, if the graph contains a single point, then all its homologies are trivial). This leads to the definition of the reduced homology. For a graph, the reduced 0-th homology is: This "reduction" affects only the 0-th homology; the reduced homologies of higher dimensions are equal to the standard homologies.
Higher dimensional homologies
A graph has only vertices (0-dimensional elements) and edges (1-dimensional elements). We can generalize the graph to an abstract simplicial complex by adding elements of a higher dimension. Then, the concept of graph homology is generalized by the concept of simplicial homology.
Example
In the above example graph, we can add a two-dimensional "cell" enclosed between the edges c and d; let's call it A and assume that it is oriented clockwise. Define C2 as the free abelian group generated by the set of two-dimensional cells, which in this case is a singleton {A}. Each element of C2 is called a 2-dimensional chain.
Just like the boundary operator from C1 to C0, which we denote by , there is a boundary operator from C2 to C1, which we denote by . In particular, the boundary of the 2-dimensional cell A are the 1-dimensional edges c and d, where c is in the "correct" orientation and d is in a "reverse" orientation; therefore: . The sequence of chains and boundary operators can be presented as follows: The addition of the 2-dimensional cell A implies that its boundary, c-d, no longer represents a hole (it is homotopic to a single point). Therefore, the group of "holes" now has a single generator, namely a+b+c (it is homotopic to a+b+d). The first homology group is now defined as the quotient group: Here, is the group of 1-dimensional cycles, which is isomorphic to Z2, and is the group of 1-dimensional cycles that are boundaries of 2-dimensional cells, which is isomorphic to Z. Hence, their quotient H1 is isomorphic to Z. This corresponds to the fact that X now has a single hole. Previously. the image of was the trivial group, so the quotient was equal to . Suppose now that we add another oriented 2-dimensional cell B between the edges c and d, such that . Now C2 is the free abelian group generated by {A,B}. This does not change H1 - it is still isomorphic to Z (X still has a single 1-dimensional hole). But now C2 contains the two-dimensional cycle A-B, so has a non-trivial kernel. This cycle generates the second homology group, corresponding to the fact that there is a single two-dimensional hole: We can proceed and add a 3-cell - a solid 3-dimensional object (called C) bounded by A and B. Define C3 as the free abelian group generated by {C}, and the boundary operator . We can orient C such that ; note that the boundary of C is a cycle in C2. Now the second homology group is: corresponding to the fact that there are no two-dimensional holes (C "fills the hole" between A and B).
General case
In general, one can define chains of any dimension. If the maximum dimension of a chain is k, then we get the following sequence of groups: It can be proved that any boundary of a (k+1)-dimensional cell is a k-dimensional cycle. In other words, for any k, (the group of boundaries of k+1 elements) is contained in (the group of k-dimensional cycles). Therefore, the quotient is well-defined, and it is defined as the k-th homology group:
References
Homology theory
Graph theory | Graph homology | [
"Mathematics"
] | 2,189 | [
"Discrete mathematics",
"Mathematical relations",
"Graph theory",
"Combinatorics"
] |
64,675,556 | https://en.wikipedia.org/wiki/Vogel%E2%80%93Fulcher%E2%80%93Tammann%20equation | The Vogel–Fulcher–Tammann equation, also known as Vogel–Fulcher–Tammann–Hesse equation or Vogel–Fulcher equation (abbreviated: VFT equation), is used to describe the viscosity of liquids as a function of temperature, and especially its strongly temperature dependent variation in the supercooled regime, upon approaching the glass transition. In this regime the viscosity of certain liquids can increase by up to 13 orders of magnitude within a relatively narrow temperature interval.
The VFT equation reads as follows:
where and are empirical material-dependent parameters, and is also an empirical fitting parameter, and typically lies about 50 °C below the glass transition temperature. These three parameters are normally used as adjustable parameters to fit the VFT equation to experimental data of specific systems.
The VFT equation is named after Hans Vogel, Gordon Scott Fulcher (1884–1971) and Gustav Tammann (1861–1938).
References
Eponymous equations of physics
Equations of fluid dynamics | Vogel–Fulcher–Tammann equation | [
"Physics",
"Chemistry"
] | 203 | [
"Equations of fluid dynamics",
"Equations of physics",
"Eponymous equations of physics",
"Fluid dynamics stubs",
"Fluid dynamics"
] |
64,677,509 | https://en.wikipedia.org/wiki/Cobalt%20monosilicide | Cobalt monosilicide (CoSi) is an intermetallic compound, a silicide of cobalt. It is a diamagnetic semimetal with an electrical resistivity of around 1 mΩ·cm.
References
Cobalt compounds
Transition metal silicides
Iron monosilicide structure type | Cobalt monosilicide | [
"Chemistry"
] | 62 | [
"Alloys",
"Alloy stubs"
] |
64,677,653 | https://en.wikipedia.org/wiki/Zammis%20Clark | Zammis Clark (born 1994), also known as wack0, Slipstream or Raylee, is a British computer security specialist and former employee of Malwarebytes. Clark is suspected to have hacked numerous large entities, including VTech, Nintendo, Microsoft, and North Korea, leaking Version 3.0 of its Red Star Operating System.
In 2019, Clark pleaded guilty to charges relating to hacking and data breaches, but did not receive a custodial sentence, instead receiving a suspended sentence lasting 15 months for infiltrating Microsoft and Nintendo's servers between March and May 2018.
See also
Nintendo data leak
References
Hackers
British cybercriminals
Living people
1994 births | Zammis Clark | [
"Technology"
] | 142 | [
"Computer security stubs",
"Computing stubs",
"Lists of people in STEM fields",
"Hackers"
] |
64,678,062 | https://en.wikipedia.org/wiki/Utpatti%20pidugu | The term 'Utpatti pidugu' is arguably a name that appears on many inscriptions from ancient India. Many historians have taken note of these inscriptions and have written extensively on them. The meaning of these words is 'thunder bolt' and it is believed that it may be the name of an artist guild working in Andhra Pradesh. The inscription is written is Telugu-Kannada script.
K.V. Soundararajan has read the inscription as Utpatipidugu and interprets it as a pilgrim label. Deepak Kannal and Jayaram Poduval have worked on a special volume titled 'Sri Utpattipidugu', Nirukta, 2005. Deepak Kannal believes that Utpatti pidugu could be the name of a religious leader who created a new movement and was able to gain political influence.
List of sites on which this title occurs
List of sites:
Cave temples
Akkanna Madanna
Mogalrajapuram
Undavalli
Ghatnandra
Bhokardan
Structural temples
Alampur
Satyavolu
Mahanandisvara temple at Mahanandi - The inscription here reads thus, "vanjjita i (U)tpattipidugu koluvu kkamiya Pritivi Bhi(ma) vrase, which has been deciphered by Deepak Kannal with the help of Krishna Shastri as "Vanchhita Sri Utpattipidugu koluvu Kamiya Ptrivibhima. Vrase...". i.e. created as per the desire of Sri Utpattipidugu. Written in the service of Kamiya Prthvibhima. This has been mentioned in the volume titled 'Sri Utpattipidugu', Nirukta, Journal of Art History and Aesthetics, Baroda, MS University, 2005.
B.Rajendra Prasad further adds that in a sandstone quarry located at Satanikota, Andhra Pradesh inscriptions have been found on boulders thus - "Sri Utpatti Pidugu, Sri Attumnan, Ekantanivasi loka sila bhima..." Many carved stones and pillars were also recovered from this site.
See also
References
Palaeography
Lightning
Telugu language | Utpatti pidugu | [
"Physics"
] | 460 | [
"Physical phenomena",
"Electrical phenomena",
"Lightning"
] |
64,679,396 | https://en.wikipedia.org/wiki/Depot%20injection | A depot injection, also known as a long-acting injectable (LAI), is a term for an injection formulation of a medication which releases slowly over time to permit less frequent administration of a medication. They are designed to increase medication adherence and consistency, especially in patients who commonly forget to take their medicine. Depot injections can be created by modifying the drug molecule itself, as in the case of prodrugs, or by modifying the way it is administered, as in the case of oil/lipid suspensions. Depot injections can have a duration of action of one month or greater and are available for many types of drugs, including antipsychotics and hormones.
Purpose
Depot injections provide longer duration drug action through slow absorption into the bloodstream. They are usually administered in the muscle, into the skin, or under the skin. The injected medication slowly releases the medication into the bloodstream. It may be used in patients who forget to take their medication; some doctors and patients consider the use of a depot injection to be coercion, and are opposed to their use for that reason.
Mechanism
Drugs may be modified to be slowly activated by the body, or be absorbed slowly by the body. Many are dissolved in an organic oil, as the compound is lipophilic due to the addition of functional groups to provide slow action. An example of this is adding a functional group such as decanoate. The combination of an oil base and modification to decrease metabolic activation prevent medications from being fully released. This can result in length of activity of 2–4 weeks or more.
The alteration of the pharmacokinetics of the drug (the absorption and activation) does not change the side effect profile of the medication; thus, atypical antipsychotics are still preferred over typical antipsychotics.
Discovery
The first long-acting (depot) injections were antipsychotics fluphenazine and haloperidol. The concept of a depot injection arose before 1950, and originally was used to describe antibiotic injections that lasted longer to allow for less frequent administration.
Pharmacokinetics
Most commonly, depot injections are designed to have a duration of 2–4 weeks of action, however the pharmacokinetics of a specific formulation vary. Absorption and metabolism can both be affected by modifying the drug itself (for example, by attaching a functional group) or by the formulation of the product (examples are oil or microsphere preparations). Repeated administration of depot injections can lead to a half life over one month (as in some preparations of fluphenazine), but this can be variable in different patients.
Hormonal depot injections of estradiol can last anywhere from one week to over one month. Medroxyprogesterone acetate is available as a depot injection which is injected once every three months to provide continuous hormonal contraception and releases for up to nine months after injection.
Availability
Many medications are available as depot injections, including many typical and atypical antipsychotics, as well as some hormonal medications and medication for opioid use disorder. Depot injections of antipsychotics are used to improve historically low adherence in patients with diseases such as schizophrenia. Different products may be administered or implanted either by a doctor or nurse, while some are designed to be administered by the patient themselves. Self-administered depot injections are used to increase healthcare access and decrease the need to visit the doctor as frequently, especially in low and middle income countries.
Insulin may also be considered a depot injection depending on formulation. Insulin glargine, for example, is designed to precipitate after injection so it can be slowly absorbed by the body over a longer period than regular insulin would be. Depot injections of insulins have been studied to better replicate the body's natural basal rate of insulin production, and which can be activated by light to control the release of insulin from the injected depot.
See also
Flip–flop kinetics
References
Medical treatments
Routes of administration
Dosage forms
Injection (medicine) | Depot injection | [
"Chemistry"
] | 836 | [
"Pharmacology",
"Routes of administration"
] |
64,679,997 | https://en.wikipedia.org/wiki/Laser%20diode%20thermal%20desorption | Laser diode thermal desorption (LDTD) is an ionization technique that is coupled to mass spectrometry to analyze samples with atmospheric pressure chemical ionization (APCI). It uses a laser to thermally desorb analytes that are deposited on a stainless steel sheet sample holder, called LazWell. The coupling of LDTD and APCI is considered to be a soft-ionization technique. With LDTD-APCI, it is possible to analyze samples in forensics, pharmaceuticals, environment, food and clinical studies. LDTD is suitable for small molecules between 0 and 1200 Da and some peptides such as cyclosporine.
History
In 2005, a patent was filed by Phytronix Technologies Inc., from Quebec, Canada, for the LDTD ion source for mass spectrometry. In 2016, the Luxon Ion Source, based on the same technology, was put on the market.
Principle of operation
An aliquot of the sample preparation between 1 and 10 μL is deposited with a pipette into the well of a metal sample holder and dried with a temperature between room temperature and 40 degrees Celsius. After the sample is completely dried, the sample holder is inserted into the ion source. Compared with desorption electrospray ionization (DESI), direct analysis in real time (DART) and matrix-assisted laser desorption/ionization (MALDI), where the droplets, gas or laser come into direct contact with the sample, LDTD relies on heat transfer through a metal surface. An infrared laser diode array (980 nm) is collimated to heat the back of the sample holder causing the desorption of the molecules. The gas-phase neutral molecules are then transported through a transfer tube, which is pneumatically and sequentially inserted into each well, with a carrier gas into a corona discharge region to undergo an atmospheric pressure ionization. The ions enter the mass spectrometer through the inlet to be measured by the detector. This whole process takes between 0.7 and 10 seconds depending on the laser pattern and the method created by the user. The carrier gas used is compressed air which contains a concentration of water between 3 and 1800 ppm to be able to efficiently protonate the molecules.
Adding to the mass spectrometer's software-controlled parameters, three other parameters can be varied to achieve a higher sensibility or reproducibility: the carrier gas flow, the laser power and the laser gradient. An important part of the analysis is also the sample preparation. The most common sample preparation methods used with LDTD are liquid-liquid extraction (LLE), protein precipitation, solid phase extraction (SPE) or a dilution.
Ionization mechanism
Since LDTD is always coupled to APCI, the same ionization mechanism happens. The main difference is that no solvent or mobile phase is available and the protons come from the water content of the carrier gas. A water concentration between 3 and 1800 ppm is recommended.
The ionization can be done in negative or positive mode.
In some applications, such as the analysis of tacrolimus in whole blood, ammonium hydroxide is added to the carrier gas to modify the ionization process.
Sample holder
The sample holders that can be inserted in LDTD ion sources are named LazWell and are specially designed 96, 384 or 1536-well plates. Different coatings can be applied depending on the molecules being analyzed. The hexagonal well shape is designed to concentrate the sample in the path of the laser for an optimal desorption.
Advantages
Since no solvent or mobile phase carries the sample, this technique is characterized by a highly efficient protonation and a strong resistance to ionic suppression. This and the fact that no needle touches the samples adds the benefit of eliminating carry over between the different wells of the plate. The technology is also a good alternative for the traditional LC-MS users since the results give a similar peak shape as in liquid chromatography and it significantly reduces the analysis time. It also uses low volumes of samples, which is an asset in applications where the available sample volume is limited or difficult to acquire. In addition, it is deemed to be an environmentally friendly alternative to LC-MS/MS.
The ion sources, LDTD and Luxon Ion Source, can be attached to different mass spectrometers with its adapted source housing, available for multiple manufacturers, such as triple quadrupole, time-of-flight, and orbitrap mass spectrometers.
On the downside, since no chromatographic separation is done, interferences coming from isobaric compounds may occur in heavily charged matrices. Differential ion mobility spectrometry-mass spectrometry (DMS-MS) or high-resolution mass spectrometry (HRMS) can be used in tandem with LDTD to eliminate these interferences.
Disadvantages
While it only requires a small volume of sample, this technique results in a destruction of that sample. The manual sample placing required can cause a variation in results achieved. Care must be taken when designing methods within an experiment using this technology as the lack of chromatography can cause the inability to analyze isomers.
References
Ion source | Laser diode thermal desorption | [
"Physics"
] | 1,085 | [
"Ion source",
"Mass spectrometry",
"Spectrum (physical sciences)"
] |
64,680,945 | https://en.wikipedia.org/wiki/Nonadaptive%20radiation | Nonadaptive radiations are a subset of evolutionary radiations (or species flocks) that are characterized by diversification that is not driven by resource partitioning. The species that are a part of a nonadaptive radiation will tend to have very similar niches, and in many (though not all) cases will be morphologically similar. Nonadaptive radiations are driven by nonecological speciation. In many cases, this nonecological speciation is allopatric, and the organisms are dispersal-limited such that populations can be geographically isolated within a landscape with relatively similar ecological conditions. For example, Albinaria land snails on islands in the Mediterranean and Batrachoseps salamanders from California each include relatively dispersal-limited, and closely related, ecologically similar species often have minimal range overlap, a pattern consistent with allopatric, nonecological speciation. In other cases, such as certain damselflies and crickets from Hawaii, there can be range overlap in closely related species, and it is likely that sexual selection (and species recognition) plays a role in maintaining (and perhaps giving rise to) species boundaries.
See also
Adaptive radiation
Species complex
Ecological speciation
References
Speciation
Ecology
Evolutionary biology
Paleobiology | Nonadaptive radiation | [
"Biology"
] | 253 | [
"Evolutionary biology",
"Evolutionary processes",
"Speciation",
"Ecology",
"Paleobiology"
] |
64,681,276 | https://en.wikipedia.org/wiki/6G | In telecommunications, 6G is the designation for a future technical standard of a sixth-generation technology for wireless communications.
It is the planned successor to 5G (ITU-R IMT-2020), and is currently in the early stages of the standardization process, tracked by the ITU-R as IMT-2030 with the framework and overall objectives defined in recommendation ITU-R M.2160-0. Similar to previous generations of the cellular architecture, standardization bodies such as 3GPP and ETSI, as well as industry groups such as the Next Generation Mobile Networks (NGMN) Alliance, are expected to play a key role in its development.
Numerous companies (Airtel, Anritsu, Apple, Ericsson, Fly, Huawei, Jio, Keysight, LG, Nokia, NTT Docomo, Samsung, Vi, Xiaomi), research institutes (Technology Innovation Institute, the Interuniversity Microelectronics Centre) and countries (United States, United Kingdom, European Union member states, Russia, China, India, Japan, South Korea, Singapore, Saudi Arabia, United Arab Emirates, and Israel) have shown interest in 6G networks, and are expected to contribute to this effort.
6G networks will likely be significantly faster than previous generations, thanks to further improvements in radio interface modulation and coding techniques, as well as physical-layer technologies. Proposals include a ubiquitous connectivity model which could include non-cellular access such as satellite and WiFi, precise location services, and a framework for distributed edge computing supporting more sensor networks, AR/VR and AI workloads. Other goals include network simplification and increased interoperability, lower latency, and energy efficiency. It should enable network operators to adopt flexible decentralized business models for 6G, with local spectrum licensing, spectrum sharing, infrastructure sharing, and intelligent automated management. Some have proposed that machine-learning/AI systems can be leveraged to support these functions.
The NGMN alliance have cautioned that "6G must not inherently trigger a hardware refresh of 5G RAN infrastructure", and that it must "address demonstrable customer needs". This reflects industry sentiment about the cost of the 5G rollout, and concern that certain applications and revenue streams have not lived up to expectations. 6G is expected to begin rolling out in the early 2030s, but given such concerns it is not yet clear which features and improvements will be implemented first.
Expectations
6G networks are expected to be developed and released by the early 2030s. The largest number of 6G patents have been filed in China.
Features
Recent academic publications have been conceptualizing 6G and new features that may be included. Artificial intelligence (AI) is included in many predictions, from 6G supporting AI infrastructure to "AI designing and optimizing 6G architectures, protocols, and operations." Another study in Nature Electronics looks to provide a framework for 6G research stating "We suggest that human-centric mobile communications will still be the most important application of 6G and the 6G network should be human-centric. Thus, high security, secrecy and privacy should be key features of 6G and should be given particular attention by the wireless research community."
Transmission
The frequency bands for 6G are undetermined. Initially, Terahertz was considered an important band for 6G, as indicated by the Institute of Electrical and Electronics Engineers which stated that "Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum."
One of the challenges in supporting the required high transmission speeds will be the limitation of energy consumption and associated thermal protection in the electronic circuits.
As of now, mid bands are being considered by WRC for 6G/IMT-2030.
Terahertz and millimeter wave progress
Millimeter waves (30 to 300 GHz) and terahertz radiation (300 to 3,000 GHz) might, according to some speculations, be used in 6G. However, the wave propagation of these frequencies is much more sensitive to obstacles than the microwave frequencies (about 2 to 30 GHz) used in 5G and Wi-Fi, which are more sensitive than the radio waves used in 1G, 2G, 3G and 4G. Therefore, there are concerns those frequencies may not be commercially viable, especially considering that 5G mmWave deployments are very limited due to deployment costs.
In October 2020, the Alliance for Telecommunications Industry Solutions (ATIS) launched a "Next G Alliance", an alliance consisting of AT&T, Ericsson, Telus, Verizon, T-Mobile, Microsoft, Samsung, and others that "will advance North American mobile technology leadership in 6G and beyond over the next decade."
In January 2022, Purple Mountain Laboratories of China claimed that its research team had achieved a world record of 206.25 gigabits per second (Gbit/s) data rate for the first time in a lab environment within the terahertz frequency band, which is supposed to be the base of 6G cellular technology.
In February 2022, Chinese researchers stated that they had achieved a record data streaming speed using vortex millimetre waves, a form of extremely high-frequency radio wave with rapidly changing spins, the researchers transmitted 1 terabyte of data over a distance of 1 km (3,300 feet) in a second. The spinning potential of radio waves was first reported by British physicist John Henry Poynting in 1909, but making use of it proved to be difficult. Zhang and colleagues said their breakthrough was built on the hard work of many research teams across the globe over the past few decades. Researchers in Europe conducted the earliest communication experiments using vortex waves in the 1990s. A major challenge is that the size of the spinning waves increases with distance, and the weakening signal makes high-speed data transmission difficult. The Chinese team built a unique transmitter to generate a more focused vortex beam, making the waves spin in three different modes to carry more information, and developed a high-performance receiving device that could pick up and decode a huge amount of data in a split second.
In 2023, Nagoya University in Japan reported successful fabrication of three-dimensional wave guides with niobium metal,
a superconducting material that minimizes attenuation due to absorption and radiation, for transmission of waves in the frequency band, deemed useful in 6G networking.
Test satellites
On November 6, 2020, China launched a Long March 6 rocket with a payload of thirteen satellites into orbit. One of the satellites reportedly served as an experimental testbed for 6G technology, which was described as "the world's first 6G satellite."
Geopolitics
During rollout of 5G, China banned Ericsson in favour of Chinese suppliers, primarily Huawei and ZTE. Huawei and ZTE were banned in many Western countries over concerns of spying. This creates a risk of 6G network fragmentation. Many power struggles are expected during the development of common standards. In February 2024, the U.S., Australia, Canada, the Czech Republic, Finland, France, Japan, South Korea, Sweden and the U.K. released a joint statement stating that they support a set of shared principles for 6G for "open, free, global, interoperable, reliable, resilient, and secure connectivity."
6G is considered a key technology for economic competitiveness, national security, and the functioning of society. It is a national priority in many countries and is named as priority in China's Fourteenth five-year plan.
Many countries are favouring the OpenRAN approach, where different suppliers can be integrated together and hardware and software are independent of supplier.
References
External links
Mobile telecommunications
Internet of things
Data centers
Wireless communication systems
Technology forecasting | 6G | [
"Technology"
] | 1,611 | [
"Data centers",
"Mobile telecommunications",
"Computers",
"Wireless communication systems"
] |
64,681,338 | https://en.wikipedia.org/wiki/Nonecological%20speciation | When speciation is not driven by (or strongly correlated with) divergent natural selection, it can be said to be nonecological, so as to distinguish it from the typical definition of ecological speciation: "It is useful to consider ecological speciation as its own form of species formation because it focuses on an explicit mechanism of speciation: namely divergent natural selection. There are numerous ways other than via divergent natural selection in which populations might become genetically differentiated and reproductively isolated." It is likely that many instances of nonecological speciation are allopatric, especially when the organisms in question are poor dispersers (e.g., land snails, salamanders), however sympatric nonecological speciation may also be possible, especially when accompanied by an "instant" (at least in evolutionary time) loss of reproductive compatibility, as when polyploidization happens. Other potential mechanisms for nonecological speciation include mutation-order speciation and changes in chirality in gastropods.
Nonecological speciation might not be accompanied by strong morphological differentiation, so might give rise to cryptic species, however there are some species that are difficult for humans to differentiate that are strongly differentiated with respect to their resource use, and so are likely a result of ecological speciation (e.g., host shifts in parasites or phytophagous insects). When species recognition/sexual selection plays a strong role in maintaining species boundaries, the species generated by nonecological speciation might be straightforward for humans to differentiate, as in some odonates.
See also
Nonadaptive radiation
References
Ecology
Evolutionary biology | Nonecological speciation | [
"Biology"
] | 334 | [
"Evolutionary biology",
"Evolutionary processes",
"Speciation",
"Ecology"
] |
64,681,487 | https://en.wikipedia.org/wiki/HAT-P-15 | HAT-P-15 is a G-type main-sequence star about 630 light-years away. The star is older than Sun yet has a concentration of heavy elements roughly 190% of solar abundance. The star has no noticeable starspot activity.
The spectroscopic survey in 2015 have failed to find any stellar companions to it, yet imaging survey have identified a possibly two companion red dwarf stars at projected separations 1210 and 1370 AU, respectively.
The star was named Berehynia in December 2019 by Ukrainian amateur astronomers.
Planetary system
In 2010 a transiting hot superjovian planet b (named Tryzub in 2019) was detected. It has an equilibrium temperature of 904 K. An orbital simulation shows that any planets inward of the orbit of b would spiral inward and be destroyed within a time-span of less than a billion years. The planetary orbit is well aligned with the equatorial plane of the star, misalignment equal to 13 degrees.
References
Perseus (constellation)
G-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
J04245952+3927382
Berehynia | HAT-P-15 | [
"Astronomy"
] | 236 | [
"Perseus (constellation)",
"Constellations"
] |
64,682,048 | https://en.wikipedia.org/wiki/WASP-50 | WASP-50 is a G-type main-sequence star about 594 light-years away. The star is older than the Sun and slightly depleted in heavy elements compared to the Sun, and has a close to average starspot activity. Despite its advanced age, the star is rotating rapidly, being spun up by the tides raised by giant planet on close orbit.
The star was named Chaophraya in December 2019 by the Thai amateur astronomers.
Planetary system
In 2011 a transiting hot superjovian planet b (named Maeping in 2019) was detected. In 2022 its albedo was found to be no more than 0.44, meaning that the planet reflects less than 44% of the light irradiated by its host star. This allows the planetary equilibrium temperature to be constrained at .
References
Eridanus (constellation)
G-type main-sequence stars
Planetary systems with one confirmed planet
Planetary transit variables
J02544513-1053530 | WASP-50 | [
"Astronomy"
] | 195 | [
"Constellations",
"Eridanus (constellation)",
"Astronomy organizations",
"Wide Angle Search for Planets"
] |
64,682,992 | https://en.wikipedia.org/wiki/List%20of%20Baby%20Einstein%20videos | Baby Einstein (The Baby Einstein Company) is a series of videos designed for infants. Founded by Julie Aigner-Clark in 1996 in her Atlanta home, Clark couldn't find a video to share with her first-born child, Aspen Clark. After successful sales in the first five years, Clark sold the company to The Walt Disney Company (Disney), also known as Buena Vista in 2001. After eleven years of producing videos, Disney sold the company to Kids II, Inc. in 2013. The franchise has since been rebranded under Kids II, which primarily focuses on toys and other infant products.
Julie Aigner-Clark's videos
All videos were directed by Julie Aigner-Clark. Following the purchase of the company by Disney, each of the following videos were re-released sometime in 2004-2008, with some alterations.
Disney videos
Discovery Kit Videos
In 2010, a series of Baby Einstein box sets called Discovery Kits were made with Julie Aigner-Clark as the director. Later in 2012, they were released as original videos. The nine Discovery Kits came with a DVD, CD with selections of music heard in the video, and a book and discovery cards for small children.
References
Multimedia works
Baby Einstein | List of Baby Einstein videos | [
"Technology"
] | 248 | [
"Multimedia",
"Multimedia works"
] |
64,683,244 | https://en.wikipedia.org/wiki/Doroth%C3%A9e%20Normand-Cyrot | Dorothée Normand-Cyrot is a French applied mathematician and control theorist, known for her work on discrete-time nonlinear control systems.
Education and career
As a teenager entering the French university system in 1971, Normand-Cyrot found the grandes écoles closed off to her because she was female; instead she went to a lesser university to study mathematics. Her mentors included algebraist Andrée Ehresmann and, a few years later, control theorist Michel Fliess.
Normand-Cyrot worked for two years for Électricité de France, earned a doctorat de troisième cycle in mathematics in 1978 at Paris Diderot University, became a researcher for the French National Centre for Scientific Research (CNRS) in 1981, and completed her doctorat d'état in 1983 at Paris-Sud University. She became a director of research for CNRS in 1991, and was posted by CNRS to the Laboratoire des signaux et systèmes at Paris-Saclay University.
Recognition
Normand-Cyrot was named an IEEE Fellow in 2005, "for contributions to discrete-time and digital nonlinear control systems".
References
External links
Year of birth missing (living people)
Living people
Control theorists
Fellows of the IEEE
Research directors of the French National Centre for Scientific Research
20th-century French women mathematicians
20th-century French mathematicians
21st-century French women mathematicians
21st-century French mathematicians | Dorothée Normand-Cyrot | [
"Engineering"
] | 284 | [
"Control engineering",
"Control theorists"
] |
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