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47,309,932 | https://en.wikipedia.org/wiki/Fellow%20of%20the%20Royal%20Society%20of%20Biology | Fellowship of the Royal Society of Biology (FRSB), previously Fellowship of the Society of Biology (FSB), is an award and fellowship granted to individuals that the Royal Society of Biology has adjudged to have made a "prominent contribution to the advancement of the biological sciences, and has gained no less than five years of experience in a position of senior responsibility".
Fellowship
Fellows are entitled to use the post-nominal letters FRSB. examples of fellows include Sir David Attenborough, Martin Hume Johnson, Jasmin Fisher, Sir Tom Blundell and Dame Nancy Rothwell. See the :Category: Fellows of the Royal Society of Biology for more examples.
References
Royal Society of Biology
Academic awards | Fellow of the Royal Society of Biology | Technology | 145 |
7,498,981 | https://en.wikipedia.org/wiki/Cross-flow%20filtration | In chemical engineering, biochemical engineering and protein purification, cross-flow filtration (also known as tangential flow filtration) is a type of filtration (a particular unit operation). Cross-flow filtration is different from dead-end filtration in which the feed is passed through a membrane or bed, the solids being trapped in the filter and the filtrate being released at the other end. Cross-flow filtration gets its name because the majority of the feed flow travels tangentially across the surface of the filter, rather than into the filter. The principal advantage of this is that the filter cake (which can blind the filter) is substantially washed away during the filtration process, increasing the length of time that a filter unit can be operational. It can be a continuous process, unlike batch-wise dead-end filtration.
This type of filtration is typically selected for feeds containing a high proportion of small particle size solids (where the permeate is of most value) because solid material can quickly block (blind) the filter surface with dead-end filtration. Industrial examples of this include the extraction of soluble antibiotics from fermentation liquors.
The main driving force of cross-flow filtration process is transmembrane pressure. Transmembrane pressure is a measure of pressure difference between two sides of the membrane. During the process, the transmembrane pressure might decrease due to an increase of permeate viscosity, therefore filtration efficiency decreases and can be time-consuming for large-scale processes. This can be prevented by diluting permeate or increasing flow rate of the system.
Operation
In cross-flow filtration, the feed is passed across the filter membrane (tangentially) at positive pressure relative to the permeate side. A proportion of the material which is smaller than the membrane pore size passes through the membrane as permeate or filtrate; everything else is retained on the feed side of the membrane as retentate.
With cross-flow filtration the tangential motion of the bulk of the fluid across the membrane causes trapped particles on the filter surface to be rubbed off. This means that a cross-flow filter can operate continuously at relatively high solids loads without blinding.
Benefits over conventional filtration
A higher overall liquid removal rate is achieved by the prevention of filter cake formation
Process feed remains in the form of a mobile slurry, suitable for further processing
Solids content of the product slurry may be varied over a wide range
It is possible to fractionate particles by size
Tubular pinch effect
Industrial applications
Cross-flow membrane filtration technology has been used widely in industry around the globe. Filtration membranes can be polymeric or ceramic, depending upon the application. The principles of cross-flow filtration are used in reverse osmosis, nanofiltration, ultrafiltration and microfiltration. When purifying water, it can be very cost-effective in comparison to the traditional evaporation methods.
In protein purification, the term tangential flow filtration (TFF) is used to describe cross-flow filtration with membranes. The process can be used at different stages during purification, depending on the type of membrane selected.
In the photograph of an industrial filtration unit (right), it is possible to see that the recycle pipework is considerably larger than either the feed pipework (vertical pipe on the right hand side) or the permeate pipework (small manifolds near to the rows of white clamps). These pipe sizes are directly related to the proportion of liquid that flows through the unit. A dedicated pump is used to recycle the feed several times around the unit before the solids-rich retentate is transferred to the next part of the process.
Techniques to improve performance
Backwashing
In backwashing, the transmembrane pressure is periodically inverted by the use of a secondary pump, so that permeate flows back into the feed, lifting the fouling layer from the surface of the membrane. Backwashing is not applicable to spirally wound membranes and is not a general practice in most applications. (See Clean-in-place)
Alternating tangential flow (ATF)
A diaphragm pump is used to produce an alternating tangential flow, helping to dislodge retained particles and prevent membrane fouling. Repligen is the largest producer of ATF systems.
Clean-in-place (CIP)
Clean-in-place systems are typically used to remove fouling from membranes after extensive use. The CIP process may use detergents, reactive agents such as sodium hypochlorite and acids and alkalis such as citric acid and sodium hydroxide (NaOH). Sodium hypochlorite (bleach) must be removed from the feed in some membrane plants. Bleach oxidizes thin-film membranes. Oxidation will degrade the membranes to a point where they will no longer perform at rated rejection levels and have to be replaced. Bleach can be added to a sodium hydroxide CIP during an initial system start-up before spirally-wound membranes are loaded into the plant to help disinfect the system. Bleach is also used to CIP perforated stainless steel (Graver) membranes, as their tolerance for sodium hypochlorite is much higher than a spirally-wound membrane. Caustics and acids are most often used as primary CIP chemicals. Caustic removes organic fouling and acid removes minerals. Enzyme solutions are also used in some systems for helping remove organic fouling material from the membrane plant. The pH and temperature are important to a CIP program. If pH and temperature are too high the membrane will degrade and flux performance will suffer. If pH and temperature are too low, the system simply will not be cleaned properly. Every application has different CIP requirements. e.g. a dairy reverse osmosis (RO) plant most likely will require a more rigorous CIP program than a water purification RO plant. Each membrane manufacturer has their own guidelines for CIP procedures for their product.
Concentration
The volume of the fluid is reduced by allowing permeate flow to occur. Solvent, solutes, and particles smaller than the membrane pore size pass through the membrane, while particles larger than the pore size are retained, and thereby concentrated. In bioprocessing applications, concentration may be followed by diafiltration.
Diafiltration
In order to effectively remove permeate components from the slurry, fresh solvent may be added to the feed to replace the permeate volume, at the same rate as the permeate flow rate, such that the volume in the system remains constant. This is analogous to the washing of filter cake to remove soluble components. Dilution and re-concentration is sometimes also referred to as "diafiltration".
Process flow disruption (PFD)
A technically simpler approach than backwashing is to set the transmembrane pressure to zero by temporarily closing off the permeate outlet, which increases the attrition of the fouling layer without the need for a second pump. PFD is not as effective as backwashing in removing fouling, but can be advantageous.
Flow rate calculation
The flux or flow rate in cross-flow filtration systems is given by the equation:
in which:
: liquid flux
: transmembrane pressure (should also include effects of osmotic pressure for reverse osmosis membranes)
: Resistance of the membrane (related to overall porosity)
: Resistance of the cake (variable; related to membrane fouling)
: liquid viscosity
Note: and include the inverse of the membrane surface area in their derivation; thus, flux increases with increasing membrane area.
See also
Dead-end filtration
Membrane fouling
References
External links
IUPAC Terminology for membranes and membrane processes (1996)
Ultrafiltration Learning Center
Cross Flow Filtration Method Handbook for protein purification
Biochemical separation processes
Filtration techniques
Water filters
Membrane technology | Cross-flow filtration | Chemistry,Biology | 1,662 |
24,407,816 | https://en.wikipedia.org/wiki/Stenopterygii | Stenopterygii are a superorder of ray-finned fish in the infraclass Teleostei. Their validity is somewhat doubtful, as the group was established to separate, out of a large group of closely related Teleostei, a mere two rather peculiarly autapomorphic orders at best. In some treatments, it is even monotypic.
As originally conceived, the "Stenopterygii" include the Ateleopodiformes and Stomiiformes. Sometimes, the former are removed to form a monotypic superorder Ateleopodomorpha. These lineages are moderately advanced teleosts, but each is uniquely adapted to a deep-water oceanic environment. Their plesiomorphies are similar to the Salmoniformes and other Protacanthopterygii, but plesiomorphic traits are no reliable indicator of a close relationship. Nonwithstanding, the "Stenopterygii" appear to be close relatives of the Protacanthopterygii. Some cladistic analyses find at least the Stomiiformes deep within the latter superorder.
It thus cannot be ruled out that the "Stenopterygii" are better included in the Protacanthopterygii. An alternative approach is to consider the entire group – "Stenopterygii", Protacanthopterygii, the monotypic superorders "Cyclosquamata", and perhaps the monotypic superorders "Lampridiomorpha" and "Scopelomorpha" – an unranked clade named Euteleostei. But this would probably require splitting up the Protacanthopterygii, so that each euteleost superorder would at most contain 2 orders (though most would be monotypic), as the relative placement of all these groups is not very well resolved. Such a profusion of monotypic taxa is generally rejected by modern taxonomy, if it is not absolutely required to adequately reflect phylogeny.
Moreover, owing to the uncertain relationships of the euteleosts to the less advanced Otocephala (which include the superorders Clupeomorpha and Ostariophysi) and the more advanced teleosts (e.g. Acanthopterygii), it may well be that the supposed "clade" is merely an evolutionary grade. Such a paraphyletic group would according to modern understanding not warrant a taxon name at all. In this case, a possible solution would be to expand the Protacanthopterygii to subsume all the small "superorders", and to treat the Euteleostei as including the Protacanthopterygii and their more "modern" relatives.
Footnotes
References
(2008): On the cephalic and pectoral girdle muscles of the deep sea fish Alepocephalus rostratus, with comments on the functional morphology and phylogenetic relationships of the Alepocephaloidei (Teleostei). Anim. Biol. 58(1): 23-29.
(2006): Fishes of the World (4th ed.). John Wiley & Sons, Inc.
Euteleostei
Fish superorders
Polyphyletic groups | Stenopterygii | Biology | 699 |
56,290,385 | https://en.wikipedia.org/wiki/HD%20163840 | HD 163840 is a binary star system in the northern constellation of Hercules. It has a combined apparent visual magnitude of 6.45, which falls just below the brightness level that is visible to the naked eye for people with normal eyesight. An annual parallax shift of 35.40 mas provides a distance estimate of about 92 light years. The system is moving closer to the Sun with a radial velocity of −33 km/s. In about 769,000 years, it will make perihelion at a separation of around .
R. K. Young of the Dominion Astrophysical Observatory was the first to recognize the variable radial velocity of this system. In 1974, Harold A. McAlister and Philip A. Ianna identified it as a nearby G-type dwarf based on its spectroscopic properties. McAlister et al. (1974) found it to be a spectroscopic binary and the components were first resolved in 1976. A series of observations since that time allowed the system's orbital elements to be published by McAlister et al. (1995), along with estimates of the stellar masses of the two components. These parameters have been further refined using improved instruments up through 2016.
The pair of stars orbit each other with a period of and an eccentricity of 0.417. The plane of their orbit is inclined by an angle of 73° to the line of sight from the Earth, with a semimajor axis having an angular value of 80.64 mas. The close, eccentric orbit of the pair does not permit a stable planetary orbit in the habitable zone of either component.
The primary, component A, is a magnitude 6.30 G-type main-sequence star with a stellar classification of G2 V. It has 1.13 times the mass of the Sun and is radiating double the Sun's luminosity from its photosphere at an effective temperature of 5,860 K. Component B, the magnitude 7.90 secondary, is a smaller K-type main-sequence star with a class of K2 V. It has 0.74 times the Sun's mass and shines with 0.65 times the Sun's luminosity at an effective temperature of 4,780 K. The system as a whole may be around 7.4 billion years old with a slightly higher metallicity than the Sun. The system displays solar-like variability.
References
G-type main-sequence stars
K-type main-sequence stars
Binary stars
Hercules (constellation)
Durchmusterung objects
Gliese and GJ objects
163840
087895
6697 | HD 163840 | Astronomy | 536 |
2,902,791 | https://en.wikipedia.org/wiki/20%20Arietis | 20 Arietis is a single star in the northern constellation of Aries. 20 Arietis is the Flamsteed designation. It has an apparent visual magnitude of 5.79, which is bright enough to be just faintly visible to the naked eye as a yellow-white hued star. The star is located approximately 137 light years away from the Sun based upon parallax. It has a relatively high proper motion, traversing the celestial sphere at the rate of 0.188 arc seconds per annum. 20 Arietis is receding from the Earth with a heliocentric radial velocity of +25 km/s.
Gray et al. (2001) gave the stellar classification of 20 Arietis as F6 III-IV, matching an F-type star with spectral traits intermediate between a giant and a subgiant star. Harlan (1969) had found a less-evolved class of F6 IV-V. The star is around two billion years old with an estimated 1.5 times the mass of the Sun and two times the Sun's radius. It is spinning with a projected rotational velocity of 8.0 km/s and has a higher than solar metallicity. The star is radiating 6.6 times the luminosity of the Sun from its photosphere at an effective temperature of around 6,416 K.
References
External links
HR 656
Image 20 Arietis
F-type main-sequence stars
F-type subgiants
F-type giants
Aries (constellation)
Durchmusterung objects
Arietis, 20
013871
010540
0656 | 20 Arietis | Astronomy | 330 |
73,934,690 | https://en.wikipedia.org/wiki/Airy%20process | The Airy processes are a family of stationary stochastic processes that appear as limit processes in the theory of random growth models and random matrix theory. They are conjectured to be universal limits describing the long time, large scale spatial fluctuations of the models in the (1+1)-dimensional KPZ universality class (Kardar–Parisi–Zhang equation) for many initial conditions (see also KPZ fixed point).
The original process Airy2 was introduced in 2002 by the mathematicians Michael Prähofer and Herbert Spohn. They proved that the height function of a model from the (1+1)-dimensional KPZ universality class - the PNG droplet - converges under suitable scaling and initial condition to the Airy2 process and that it is a stationary process with almost surely continuous sample paths.
The Airy process is named after the Airy function. The process can be defined through its finite-dimensional distribution with a Fredholm determinant and the so-called extended Airy kernel. It turns out that the one-point marginal distribution of the Airy2 process is the Tracy-Widom distribution of the GUE.
There are several Airy processes. The Airy1 process was introduced by Tomohiro Sasomoto and the one-point marginal distribution of the Airy1 is a scalar multiply of the Tracy-Widom distribution of the GOE. Another Airy process is the Airystat process.
Airy2 proces
Let be in .
The Airy2 process has the following finite-dimensional distribution
where
and is the extended Airy kernel
Explanations
If the extended Airy kernel reduces to the Airy kernel and hence
where is the Tracy-Widom distribution of the GUE.
is a trace class operator on with counting measure on and Lebesgue measure on , the kernel is .
Literature
References
Stochastic processes
Statistical mechanics | Airy process | Physics | 391 |
76,048,956 | https://en.wikipedia.org/wiki/Vermeology | Vermeology (from Latin vermes, worms) is the field of biology dedicated to the study of worms. A person who studies vermeology is referred to as a vermeologist.
The umbrella term "vermeology" has fallen out of common use, as the animals known as worms belong to multiple phyla that are not closely related. Subfields of vermeology include nematology, the study of nematodes, oligochaetology (also called lumbricology), the study of earthworms, and helminthology, which focuses on parasitic worms, also known as helminths. The field of malacology was also historically included within vermeology.
Works
The final book that Charles Darwin published in his lifetime focused on bioturbation by earthworms.
References
Zoology
Branches of biology
Subfields of zoology
Invertebrates
Worms (obsolete taxon) | Vermeology | Biology | 188 |
34,818,925 | https://en.wikipedia.org/wiki/Curtis%20Greene | Curtis Greene is an American mathematician, specializing in algebraic combinatorics. He is the J. McLain King Professor of Mathematics at Haverford College in Pennsylvania.
Greene did his undergraduate studies at Harvard University, and earned his Ph.D. in 1969 from the California Institute of Technology under the supervision of Robert P. Dilworth. He held positions at the Massachusetts Institute of Technology and the University of Pennsylvania before moving to Haverford.
Greene has written highly cited research papers on Sperner families, Young tableaux, and combinatorial equivalences between hyperplane arrangements, zonotopes, and graph orientations. With Daniel Kleitman, he has also written a highly cited survey paper on combinatorial proof techniques.
In 2012 he became a fellow of the American Mathematical Society.
References
Year of birth missing (living people)
Living people
20th-century American mathematicians
21st-century American mathematicians
Harvard University alumni
California Institute of Technology alumni
Massachusetts Institute of Technology faculty
University of Pennsylvania faculty
Haverford College faculty
Combinatorialists
Fellows of the American Mathematical Society | Curtis Greene | Mathematics | 212 |
2,902,895 | https://en.wikipedia.org/wiki/18%20Aquilae | 18 Aquilae (abbreviated 18 Aql) is a triple star system in the constellation of Aquila. 18 Aquilae is the Flamsteed designation; it also bears the variable star designation Y Aquilae. It has an apparent visual magnitude of 5.07, making it bright enough to be seen with the naked eye. The distance to this system can be estimated from the annual parallax shift of 6.43 mas, yielding a value of around away from Earth.
It took decades to determine whether or not 18 Aquilae is a variable star. It was used as a standard star in Benjamin Apthorp Gould's Uranometria Argentina, published in 1879. Gould marked the star with an asterisk, indicating that he thought it is a variable star. Gustav Müller and Paul Kempf noted Gould's opinion in their 1894 work Potsdamer Photometrische Durchmusterung, but stated that their numerous observations did not confirm that the star is variable. That same year, Seth Carlo Chandler reported that 18 Aquilae is a variable star. He stated the star showed an "unmistakable periodicity" and derived a period of 4.986 days - nearly 4 times larger than what the period is now known to be. Chandler gave the star the name Y Aquilae. In 1898, Edward Charles Pickering and Paul S. Yendell announced that their observations of the star "fail to show any evidence of variation". In 1966, Robert Arnold Breinhorst established that Y Aquilae is variable in his PhD thesis.
The inner pair of stars in this system form a spectroscopic binary with a combined magnitude of 5.44 and an orbital period of 1.302 days. The primary component is a giant star with a stellar classification of B8 III. Because the orbital plane is inclined near the line of sight, two form an eclipsing binary system. The eclipse of the primary component causes a 0.04 drop in magnitude, while the eclipse of the secondary results in a decrease of 0.03. At an angular separation of 0.310 arcseconds is the magnitude 6.39 tertiary component. This system has a high peculiar velocity of relative to the neighboring stars.
References
External links
Image 18 Aquilae
HR 7248
Aquila (constellation)
Eclipsing binaries
Spectroscopic binaries
Triple star systems
18 Aquilae A
Aquilae, 18
Aquilae, Y
178125
7248
093867
BD+10 3787 | 18 Aquilae | Astronomy | 517 |
2,541,606 | https://en.wikipedia.org/wiki/Friedrich%20Alfred%20Krupp | Friedrich Alfred Krupp (; 17February 185422November 1902) was a German steel manufacturer and head of the company Krupp. He was the son of Alfred Krupp and inherited the family business when his father died in 1887. Whereas his father had largely supplied iron and steel, Friedrich shifted his company's production back to arms manufacturing. Friedrich greatly expanded Krupp and acquired the Germaniawerft in 1896 which gave him control of warship manufacturing in Germany. He oversaw the development of nickel steel, U-boats, the diesel engine, and much more. He died in 1902, possibly by suicide, after being accused of homosexuality. His daughter Bertha inherited the company.
Early life and education
Krupp was born in Essen, Germany. His father was Alfred Krupp, who turned the small local ironworks of Krupp into one of the most powerful companies in the world. Raised in the unhealthy atmosphere of the Ruhr, he suffered from asthma and was more interested in natural sciences than business, so his father even considered passing the company to one of his own nephews.
Career
However in 1887, Friedrich took over the leadership of his late father's company. He married Baroness Margarethe von Ende (1854-1931). They had two daughters: Bertha and Barbara (married Tilo, Baron von Wilmowsky).
Whereas his father had largely supplied iron and steel for railroads in America, with the rise of Carnegie Steel, Friedrich shifted his company's production back to arms manufacturing. During his time in charge, he greatly expanded Krupp, acquiring Germaniawerft in 1896 which gave him control of warship manufacturing in Germany. He oversaw the development of nickel steel, U-boats, the diesel engine, and much more. Krupp increased and diversified the output of the Krupp Works, which he extended by the incorporation with them of other enterprises. A member of the House of Lords of Prussia and Council of State, he also sat in Germany's Reichstag from 1893 to 1898.
Personal life
For four years, beginning in 1898, Krupp spent several months of the year on the Italian island of Capri, staying at the hotel Quisisana. He kept two yachts there, Maya and Puritan. His hobby was oceanography. He met Felix Anton Dohrn and Ignazio Cerio on Capri.
In 1902 he died, apparently by suicide. His daughter Bertha inherited the company and shortly thereafter married Gustav Halbach, the grandson of Henry Bohlen.
Scandal and death
In the 1890s, the owner of a luxurious hotel in Berlin discovered that Krupp was meeting with young Italian male lovers; homosexuality was criminalized in Germany, but Krupp's ally, Kaiser Wilhelm II, prevented any development of a controversy, at least domestically. However, the Kaiser was unable to influence events in Italy.
On 15 November 1902, the Social Democratic magazine Vorwärts claimed that Friedrich Alfred Krupp was homosexual, that he had a number of liaisons with boys and men on Capri, and that his closest attachment was to Adolfo Schiano, an 18-year-old barber and amateur musician. This report appeared in the German press months after stories of an unnamed foreign businessman's homosexual orgies were printed in local and Neapolitan papers demanding an inquest. Capri locals were aware of Krupp's homosexual activities, but those in positions of power turned a blind eye, including the owner of Quisisana, who had a certain influence over a local political party, to which Krupp contributed funds. The Neopolitan paper Il Mattino was the first to publish an article, while withholding Krupp's name. Its source in Capri was a teacher who resented Krupp's choice of a different Italian language instructor. This teacher had also been heavily criticized by the same political party that had the support and patronage of Krupp, causing the teacher to support the opposing political party.
Krupp returned to Germany, waiting for the scandal to pass. Instead, Italian newspapers continued to identify a wealthy foreign capitalist as the center of homosexual activity. The first report in Germany appeared in the Catholic newspaper in August 1902. It cited reports in two Italian newspapers and like them described but did not name the industrialist.
In October 1902, Krupp's wife received anonymous letters and, according to some reports, compromising photos of her husband's orgies. She asked Kaiser Wilhelm II, a Krupp family friend, to take action against her husband, but he refused to listen. Krupp himself then had his wife committed to an insane asylum.
The newspaper Vorwärts then published their article titled "Krupp in Capri", stating:
"If Krupp continues to live in Germany, he will be subject to penalties under Paragraph 175 of the Code. When certain illegal practices lead to a public scandal, the police have a duty to promote legal action." Under Paragraph 175, homosexual acts were punishable by years of hard labor.
Krupp sued the newspaper and sought help from his allies in government, including Kaiser Wilhelm. Copies of Vorwärts were seized and destroyed, even in the homes of subscribers. It seemed that Krupp had decided to give battle. However, by now his nerves were shot, perhaps because of the suspicion that this time the scandal was so big and well-grounded that even his wealth and his friendships could not save him if due process occurred.
A week after Vorwärts published the allegations against Krupp, on 22 November 1902, Krupp died. It is uncertain whether he died of suicide or illness.
In a speech at Krupp's burial, Kaiser Wilhelm attacked the Social Democratic politicians, insisting that they had lied about Krupp's sexual orientation. Krupp's heirs initiated a lawsuit against Vorwärts, but soon abandoned the action.
References
Additional sources
Bibliography
A. Sper, Capri und die Homosexuellen: Eine psychologische Studie, Orania Verlag, Berlin s.d. ma 1903.
Guido Podrecca, La tavola rotonda in Germania, Mantegazza, Roma 1919, pp. 102–109.
Norman Douglas, Looking Back: An Autobiographical Excursion, Harcourt, Brace and Company, New York 1933. Chapter about Dottor Salvatore Lo Bianco.
Roger Peyrefitte, Les amours singulières, Paris 1949; L' exilé de Capri, Flammarion, Paris 1959.
Edwin Cerio: Capri. Ein kleines Welttheater im Mittelmeer, München, 1954, pages 135-143.
Willi Boelcke, Krupp und die Hohenzollern in Dokumenten, 1850–1918, Athenaion, Frankfurt 1970, pp. 158–162.
William Manchester, The Arms of Krupp, 1587–1968, Little & Brown, Boston 1968.
Humbert Kesel, Capri. Biographie einer Insel. Prestel Verlag, München 1971, pp. 264–268, .
Angelo Cerino, I Krupp e la guerra come industria, Cremonese, Roma 1974, pp. 59–61.
James Money, Capri. La storia e i suoi protagonisti [1986], Rusconi, Milano 1993, pp. 82–85, 91-96, 240-241.
Carlo Knight, Krupp a Capri. Uno scandalo d'altri tempi (e uno dei nostri), Civita, Napoli 1989.
Tito Fiorani, Le dimore del mito, La Conchiglia, Capri 1996, pp. 99–106.
Carlo Knight: Die Capri-Utopie von Krupp - L'utopia caprese di Krupp. 2002, Capri, La Conchiglia Edizioni.
Enrico Oliari, L'omo delinquente. Scandali e delitti gay dall'Unità a Giolitti, Prospettiva editrice, Roma 2006.
Michael Epkenhans, Ralf Stremmel (Hrsg.): Friedrich Alfred Krupp. Ein Unternehmer im Kaiserreich. Beck, München 2010, .
External links
Biography at thyssenkrupp.com (In German)
Lo scandalo Krupp (Capri, 1902) e la stampa. Indice 1902-1903. Transcriptions of Italian newspaper articles that reported homosexual activity and then covered the "Krupp Affair". (In Italian)
1854 births
1902 deaths
Businesspeople from Essen
German industrialists
People from the Rhine Province
Friedrich
German Protestants
Free Conservative Party politicians
Members of the 9th Reichstag of the German Empire
Members of the Prussian House of Lords
German steel industry businesspeople
Capri, Campania
Bessemer Gold Medal
1902 suicides | Friedrich Alfred Krupp | Chemistry | 1,846 |
1,934,129 | https://en.wikipedia.org/wiki/Explicit%20symmetry%20breaking | In theoretical physics, explicit symmetry breaking is the breaking of a symmetry of a theory by terms in its defining equations of motion (most typically, to the Lagrangian or the Hamiltonian) that do not respect the symmetry. Usually this term is used in situations where these symmetry-breaking terms are small, so that the symmetry is approximately respected by the theory. An example is the spectral line splitting in the Zeeman effect, due to a magnetic interaction perturbation in the Hamiltonian of the atoms involved.
Explicit symmetry breaking differs from spontaneous symmetry breaking. In the latter, the defining equations respect the symmetry but the ground state (vacuum) of the theory breaks it.
Explicit symmetry breaking is also associated with electromagnetic radiation. A system of accelerated charges results in electromagnetic radiation when the geometric symmetry of the electric field in free space is explicitly broken by the associated electrodynamic structure under time varying excitation of the given system. This is quite evident in an antenna where the electric lines of field curl around or have rotational geometry around the radiating terminals in contrast to linear geometric orientation within a pair of transmission lines which does not radiate even under time varying excitation.
Perturbation theory in quantum mechanics
A common setting for explicit symmetry breaking is perturbation theory in quantum mechanics. The symmetry is evident in a base Hamiltonian . This is often an integrable Hamiltonian, admitting symmetries which in some sense make the Hamiltonian integrable. The base Hamiltonian might be chosen to provide a starting point close to the system being modelled.
Mathematically, the symmetries can be described by a smooth symmetry group . Under the action of this group, is invariant. The explicit symmetry breaking then comes from a second term in the Hamiltonian, , which is not invariant under the action of . This is sometimes interpreted as an interaction of the system with itself or possibly with an externally applied field. It is often chosen to contain a factor of a small interaction parameter.
The Hamiltonian can then be written
where is the term which explicitly breaks the symmetry. The resulting equations of motion will also not have -symmetry.
A typical question in perturbation theory might then be to determine the spectrum of the system to first order in the perturbative interaction parameter.
See also
Symmetry breaking
References
Symmetry
Theoretical physics
Quantum field theory | Explicit symmetry breaking | Physics,Mathematics | 471 |
35,295,311 | https://en.wikipedia.org/wiki/Conservation%20and%20restoration%20of%20glass%20objects | Conservation and restoration of glass objects is one aspect of conservation and restoration of cultural heritage. The nature and varying composition of the material, and the variety of types of object made from it, demand certain specialized techniques. The conservator needs to be aware of "agents of deterioration" presenting particular risk to glass objects, and how to prevent or counteract their effects. Relevant education and training is available in certain countries through museums, conservation institutes and universities.
The practice of conservation-restoration
Conservation-restoration is the practice of cleaning and discovering the original state of an object, investigating the proper treatments and applying those treatments to restore the object to its original state without permanently altering the object, and then preserving the object to prevent further deterioration for generations to come (Caple, p. 5-6). It can involve many different people from various backgrounds to properly assess and treat an object, such as museum curators, conservators, scientists, and historians. The Metropolitan Museum of Art concludes that "conservators and scientists examine objects in the Museum's collections and those being considered for acquisition to determine their methods of manufacture and chemical compositions, as well as any damage or deterioration they may have undergone... conservators may then perform treatments, such as cleaning, repair, and restoration. They also recommend appropriate conditions for the storage, exhibition, and transportation of objects" (Pilosi and Wypyski, p. 66). Conservator-restorers can be found in museums, private for hire institutions, conservation associations, and government or state organizations. They not only treat glass objects, but also art, metal, ceramics, wood, and various other materials that are in need of preservation.
Historic methods of glass cleaning
Glass has been around since the Egyptian XVIII Dynasty, as the very earliest specimen is a glass bead that has been dated to that time during the reign of Queen Hatshepsut. Glass is very versatile, and there many different types of glass that serve various purposes, such as stained-glass windows, table glassware, and even glass photographic plates. This means that the treatment of these objects depends upon their uses and original purposes. Glass throughout the ages mostly consisted of glass drinking or eating vessels, and then evolved to be part of churches and housing in the form of window glass. According to the Victoria and Albert Museum, most glass is composed of silica (sand), alkali (usually soda or potash), an alkaline earth (lime) and a little waste glass. Other materials, such as lead and barium, could also be added to create a specialized effect in the finished product. Methods of cleaning have evolved from washing with water, to using special chemical cleansers especially made for glass, to even dismantling a large glass object, like a window, to be assessed and cleaned under a microscope in a lab. There was not a need to clean glass thoroughly until glass evolved as part of the 20th-century home, and it suddenly became important to keep glass windows clean and the common cleanser Windex came into the picture in the 1930s. For glass objects that are not window glass, the most common way of cleaning is by water if the glass object is intact and not super fragile. The Victoria and Albert Museum provides guidance about how to go about this way of cleaning. The methods of cleaning may differ if the glass is already damaged, extremely thin or fragile, or very old.
Agents of deterioration
One of the ways in which preventive-conservators address the care of material collections is through assessing risk and needs based on the chief agents of deterioration. Best practices employ the system of "avoiding, blocking, detecting, and responding" to any address threats. By considering these key factors as potential problems with their own needs, stakeholders can make strides in safeguarding assets such as glass objects.
Physical forces to be considered in the preventive-conservation of glass objects can include: "impact, shock, vibration, pressure, abrasion", and may relate to the need to secure both the objects themselves as well as the environment in which they reside.
Fire is a means of deterioration that can impact glass objects ranging from a potentially minimal amount of damage to a total loss. Problems with fire include burning, soot deposits, and melting, warping, discoloration, embrittlement, cracking, and even shattering. Possible interventions to these consequences include creating and maintaining plans and that cover the installation of fire protection equipment and establishing procedures for emergency situations.
Pests, such as microorganisms, insects, rodents, birds, and bats, are agents of deterioration not as often associated with the problems that occur with glass objects. However, they can affect glass objects by proxy of other agents, like physical force, such as a bird that might fly into a stained-glass window, pollutants when a rodent that leaves a byproduct.
Light, ultraviolet and infrared radiation impact glass in unique ways. While visible light can cause colorful glass to fade, ultraviolet radiation is identified as a non-problematic entity. Infrared radiation does not have a direct effect but can be a cause of heating and therefore subject the glass to problems related to incorrect temperature (see below). The best way of protecting glass from radiation is to eliminate the source as best as possible. It is not always practical to keep a piece of glass out of sight, but strategic scheduling of exposure can reduce impact.
Incorrect temperature of glass objects can lead to possible fracture. Stabilization of temperature can help significantly in keeping them from destruction.
Incorrect relative humidity in glass objects can lead to crizzling or weeping of glass. Crizzling can occur when relative humidity is below 40%, and lead to cracks in its surface. Glass weeping or sweating can occur when relative humidity is above 55% and loses luster.
Thieves and vandals are a potential problem for any object. Since glass objects are generally fragile their susceptibility to vandalism might be preempted by a collections care plan that calls for them to be secured to a stable fixture. Here, the strategy is to "protect, detect, response, and recover" any possible losses.
Water itself is not a hazard to stable glass, but in the case of a piece with existing "glass disease", it can accelerate problems associated with it such as weeping, and crizzling as mentioned above. Here, glass should not be kept in places where the threat of water exposure could occur, such as low to the ground, or near places where water might pool.
Pollutants that are airborne or atmospheric pose less of a threat to glass. However, intrinsic pollutants might cause deterioration or degradation.
Dissociation is a threat for glass objects just as it might be for any other piece. Since glass objects can be small as well as large, they can be at a greater risk for being mishandled than something more obtrusive. Dissociation can cause problems that range from misplacement, to damage, to total loss. Good records keeping is always a best practice but proves to be one of the best strategies for addressing the threat of dissociation.
Preventive conservation
Education and training
The United States
In the United States, the Corning Museum of Glass in New York is the preeminent institute for glass research through the conservation department and library. The conservation department advises on the best practices of displaying, mounting, lighting, storing, and handling glass objects. Additionally, the museum regularly holds courses on the principles and practice of historical and archaeological glass cleaning, care, conservation and restoration for conservators.
The United Kingdom
The Institute of Conservation in the United Kingdom works to conserve cultural heritage in the country with a group that specializes specifically in the care of ceramics and glass. Events hosted through the Institute include conferences and study days.
The University of York in England offers a Master's level program in Stained Glass Conservation within the Department of History and Art and in partnership with the Department of Archeology.
Portugal
The VICARTE – Vidro e Cerâmica para as Artes (Glass and Ceramic for the Arts) is a research unit composed of the Faculty of Sciences and Technology of the Universidade Nova de Lisboa and the Faculty of Fine Arts of the Universidade de Lisboa which works to further the research of glass and ceramics. In partnership with cultural heritage institutions across the country, they offer a Master's program in Glass and Ceramic Art and Science with an interdisciplinary approach to the coursework.
France
In France, the only academy where conservators and curators can receive training is at the Institut national du patrimoine (The National Institute of Cultural Heritage). A five-year training program for aspiring conservators is offered which grants students with a Master's in Conservation-Restoration, with specialties in earthenware and glassware.
See also
Conservation and restoration of metals
Conservation and restoration of copper-based objects
Conservation and restoration of ferrous objects
Conservation and restoration of ivory objects
Conservation and restoration of ceramic objects
Conservation and restoration of silver objects
References
External links
Care and conservation of ceramic and glass by The Institute of Conservation
Ceramic and glass conservation at National Museums Liverpool
Conservation and restoration of cultural heritage
Glass
Glass art
Glass chemistry | Conservation and restoration of glass objects | Physics,Chemistry,Materials_science,Engineering | 1,883 |
11,541,397 | https://en.wikipedia.org/wiki/HD%2011964 | HD 11964 is a binary star system located 110 light-years away from the Sun in the equatorial constellation of Cetus. It is visible in binoculars or a telescope but is too faint to be seen with the naked eye, having an apparent visual magnitude of 7.51. The system is drifting closer to the Sun with a radial velocity of −9 km/s. Two extrasolar planets have been confirmed to orbit the primary.
Properties
The primary, component A, is a G-type main-sequence star with a stellar classification of G9VCN+1. The suffix notation indicates an overabundance of the cyano radical in the spectrum. Houk and Swift (1999) found a class of G8IV, suggesting it is instead a more evolved subgiant star. It is around seven billion years old and is spinning slowly with a projected rotational velocity of 1.5 km/s. The star has 1.1 times the mass of the Sun and 2.2 times the Sun's radius. It is radiating 2.9 times the luminosity of the Sun from its photosphere at an effective temperature of 5,321 K.
A wide binary companion star was discovered in 2000. This secondary, designated component B, has a visual magnitude of 11.11 and lies at an angular separation of along a position angle of 134°, as of 2015. It is a red dwarf with a class of M0V, and has just 0.6 times the Sun's radius. It is radiating 0.085 times the Sun's luminosity at an effective temperature of 4,033 K.
Planetary system
In August 2005, two planets were discovered orbiting the star, the innermost like Neptune and another like Jupiter orbiting at 3.34 AU. However, the second planet (HD 11964 b) was not confirmed until May 2007. In September 2007, P.C. Gregory claimed that there was a third planet in the system on the basis of Bayesian analysis of the radial velocity data. The planet was claimed to have a mass similar to that of Saturn and located in a 360-day orbit. Gregory cautioned that the close match between the period of this planet to being exactly a year meant that the radial velocity variations may have been caused by insufficient correction for the motion of the Earth in orbit around the Sun. The planet was not detected in re-reduced data in an analysis published in the Astrophysical Journal in 2009.
See also
HD 11977
List of extrasolar planets
References
External links
Extrasolar Planet Interactions by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona
G-type main-sequence stars
G-type subgiants
M-type main-sequence stars
Binary stars
Planetary systems with two confirmed planets
Cetus
Durchmusterung objects
Gliese and GJ objects
011964
009094 | HD 11964 | Astronomy | 583 |
11,026 | https://en.wikipedia.org/wiki/List%20of%20programmers | This is a list of programmers notable for their contributions to software, either as original author or architect, or for later additions. All entries must already have associated articles.
Some persons notable as computer scientists are included here because they work in program as well as research.
A
Michael Abrash – program optimization and x86 assembly language
Scott Adams – series of text adventures beginning in the late 1970s
Tarn Adams – Dwarf Fortress
Leonard Adleman – co-created RSA algorithm (being the A in that name), coined the term computer virus
Alfred Aho – co-created AWK (being the A in that name), and main author of famous Compilers: Principles, Techniques, and Tools (Dragon book)
Andrei Alexandrescu – author, expert on languages C++, D
Paul Allen – Altair BASIC, Applesoft BASIC, cofounded Microsoft
Eric Allman – sendmail, syslog
Marc Andreessen – co-created Mosaic, cofounded Netscape
Jeremy Ashkenas – CoffeeScript programming language and Backbone.js
Bill Atkinson – QuickDraw, HyperCard
Lennart Augustsson – languages (Lazy ML, Cayenne), compilers (HBC Haskell, parallel Haskell front end, Bluespec SystemVerilog early), LPMud pioneer, NetBSD device drivers
B
Roland Carl Backhouse – computer program construction, algorithmic problem solving, ALGOL
John Backus – Fortran, BNF
Lars Bak – virtual machine specialist
Richard Bartle – MUD, with Roy Trubshaw, created MUDs
Friedrich L. Bauer – Stack (data structure), Sequential Formula Translation, ALGOL, software engineering, Bauer–Fike theorem
Kent Beck – created Extreme programming, cocreated JUnit
Donald Becker – Linux Ethernet drivers, Beowulf clustering
Brian Behlendorf – Apache HTTP Server
Doug Bell – Dungeon Master series of video games
Fabrice Bellard – created FFmpeg open codec library, QEMU virtualization tools
Tim Berners-Lee – invented World Wide Web
Daniel J. Bernstein – djbdns, qmail
Eric Bina – cocreated Mosaic web browser
Marc Blank – cocreated Zork
Joshua Bloch – core Java language designer, lead the Java collections framework project
Jonathan Blow – video games Braid and The Witness
Susan G. Bond – cocreated ALGOL 68-R
Grady Booch – cocreated Unified Modeling Language
Bert Bos – authored Argo web browser, co-authored Cascading Style Sheets
Stephen R. Bourne – cocreated ALGOL 68C, created Bourne shell
David Bradley – coder on the IBM PC project team who wrote the Control-Alt-Delete keyboard handler, embedded in all PC-compatible BIOSes
Andrew Braybrook – video games Paradroid and Uridium
Larry Breed – implementation of Iverson Notation (APL), co-developed APL\360, Scientific Time Sharing Corporation cofounder
Jack Elton Bresenham – created Bresenham's line algorithm
Dan Bricklin – cocreated VisiCalc, the first personal spreadsheet program
Walter Bright – Digital Mars, First C++ compiler, authored D (programming language)
Sergey Brin – cofounded Google Inc.
Per Brinch Hansen (surname "Brinch Hansen") – RC 4000 multiprogramming system, operating system kernels, microkernels, monitors, concurrent programming, Concurrent Pascal, distributed computing & processes, parallel computing
Richard Brodie – Microsoft Word
Andries Brouwer – Hack, former maintainer of man pager, Linux kernel hacker
Danielle Bunten Berry (Dani Bunten) – M.U.L.E., multiplayer video game and other noted video games
Rod Burstall – languages COWSEL (renamed POP-1), POP-2, NPL, Hope; ACM SIGPLAN 2009 PL Achievement Award
Dries Buytaert – created Drupal
C
Steve Capps – cocreated Macintosh and Newton
John Carmack – first-person shooters Doom, Quake
Vint Cerf – TCP/IP, NCP
Ward Christensen – wrote the first BBS (Bulletin Board System) system CBBS
Edgar F. Codd – principal architect of relational model
Bram Cohen – BitTorrent protocol design and implementation
Alain Colmerauer – Prolog
Richard W. Conway – compilers for CORC, CUPL, and PL/C; XCELL Factory Modelling System
Alan Cooper – Visual Basic
Mike Cowlishaw – REXX and NetRexx, LEXX editor, image processing, decimal arithmetic packages
Alan Cox – co-developed Linux kernel
Brad Cox – Objective-C
Mark Crispin – created IMAP, authored UW-IMAP, one of reference implementations of IMAP4
William Crowther – Colossal Cave Adventure
Ward Cunningham – created Wiki concept
Dave Cutler – architected RSX-11M, OpenVMS, VAXELN, DEC MICA, Windows NT
D
Ole-Johan Dahl – cocreated Simula, object-oriented programming
Ryan Dahl – created Node.js
James Duncan Davidson – created Tomcat, now part of Jakarta Project
Terry A. Davis – developer of TempleOS
Jeff Dean – Spanner, Bigtable, MapReduce
L. Peter Deutsch – Ghostscript, Assembler for PDP-1, XDS-940 timesharing system, QED original co-author
Robert Dewar – IFIP WG 2.1 member, chairperson, ALGOL 68; AdaCore cofounder, president, CEO
Edsger W. Dijkstra – contributions to ALGOL, Dijkstra's algorithm, Go To Statement Considered Harmful, IFIP WG 2.1 member
Matt Dillon – programmed various software including DICE and DragonflyBSD
Jack Dorsey – created Twitter
Martin Dougiamas – creator and lead developed Moodle
Adam Dunkels – authored Contiki operating system, the lwIP and uIP embedded TCP/IP stacks, invented protothreads
E
Les Earnest – authored finger program
Alan Edelman – Edelman's Law, stochastic operator, Interactive Supercomputing, Julia (programming language) cocreator, high performance computing, numerical computing
Brendan Eich – created JavaScript
Larry Ellison – co-created Oracle Database, cofounded Oracle Corporation
Andrey Ershov – languages ALPHA, Rapira; first Soviet time-sharing system AIST-0, electronic publishing system RUBIN, multiprocessing workstation MRAMOR, IFIP WG 2.1 member, Aesthetics and the Human Factor in Programming
Marc Ewing – created Red Hat Linux
F
Scott Fahlman – created smiley face emoticon :-)
Dan Farmer – created COPS and Security Administrator Tool for Analyzing Networks (SATAN) Security Scanners
Steve Fawkner – created Warlords and Puzzle Quest
Stuart Feldman – created make, authored Fortran 77 compiler, part of original group that created Unix
David Filo – cocreated Yahoo!
Brad Fitzpatrick – created memcached, Livejournal and OpenID
Andrew Fluegelman – author PC-Talk communications software; considered a cocreated shareware
Mahmoud Samir Fayed – created PWCT and Ring
Martin Fowler – created the dependency injection pattern of software engineering, a form of inversion of control
Brian Fox – created Bash, Readline, GNU Finger
G
Elon Gasper – cofounded Bright Star Technology, patented realistic facial movements for in-game speech; HyperAnimator, Alphabet Blocks, etc.
Bill Gates – Altair BASIC, cofounded Microsoft
Nick Gerakines – author, contributor to open-source Erlang projects
Jim Gettys – X Window System, HTTP/1.1, One Laptop per Child, Bufferbloat
Steve Gibson – created SpinRite
John Gilmore – GNU Debugger (GDB)
Adele Goldberg – cocreated Smalltalk
Robert Griesemer – cocreated Go
Ryan C. Gordon (a.k.a. Icculus) – Lokigames, ioquake3
James Gosling – Java, Gosling Emacs, NeWS
Bill Gosper – Macsyma, Lisp machine, hashlife, helped Donald Knuth on Vol.2 of The Art of Computer Programming (Semi-numerical algorithms)
Paul Graham – Yahoo! Store, On Lisp, ANSI Common Lisp
John Graham-Cumming – authored POPFile, a Bayesian filter-based e-mail classifier
David Gries – The book The Science of Programming, Interference freedom, Member Emeritus, IFIP Working Group 2.3 on Programming Methodology
Ralph Griswold – cocreated SNOBOL, created Icon (programming language)
Richard Greenblatt – Lisp machine, Incompatible Timesharing System, MacHack
Neil J. Gunther – authored Pretty Damn Quick (PDQ) performance modeling program
Scott Guthrie (a.k.a. ScottGu) – ASP.NET creator
Jürg Gutknecht – with Niklaus Wirth: Lilith computer; Modula-2, Oberon, Zonnon programming languages; Oberon operating system
Andi Gutmans – cocreated PHP programming language
Michael Guy – Phoenix, work on number theory, computer algebra, higher dimension polyhedra theory, ALGOL 68C; work with John Horton Conway
H
Daniel Ha – cofounder and CEO of blog comment platform Disqus
Nico Habermann – work on operating systems, software engineering, inter-process communication, process synchronization, deadlock avoidance, software verification, programming languages: ALGOL 60, BLISS, Pascal, Ada
Jim Hall – started the FreeDOS project
Margaret Hamilton – Director of Software Engineering Division of MIT Instrumentation Laboratory, which developed on-board flight software for the space Apollo program
Brian Harris – machine translation research, Canada's first computer-assisted translation course, natural translation theory, community interpreting (Critical Link)
Eric Hehner – predicative programming, formal methods, quote notation, ALGOL
David Heinemeier Hansson – created the Ruby on Rails framework for developing web applications
Rebecca Heineman – authored Bard's Tale III: Thief of Fate and Dragon Wars
Gernot Heiser – operating system teaching, research, commercialising, Open Kernel Labs, OKL4, Wombat
Anders Hejlsberg – Turbo Pascal, Delphi, C#, TypeScript
Ted Henter – founded Henter-Joyce (now part of Freedom Scientific) created JAWS screen reader software for blind people
Andy Hertzfeld – co-created Macintosh, cofounded General Magic, cofounded Eazel
D. Richard Hipp – created SQLite
C. A. R. Hoare – first implementation of quicksort, ALGOL 60 compiler, Communicating sequential processes
Louis Hodes – Lisp, pattern recognition, logic programming, cancer research
John Henry Holland – pioneer in what became known as genetic algorithms, developed Holland's schema theorem, Learning Classifier Systems
Allen Holub – author and public speaker, Agile Manifesto signatory
Grace Hopper – Harvard Mark I computer, FLOW-MATIC, COBOL
Paul Hudak – Haskell language design, textbooks on it and computer music
David A. Huffman – created the Huffman coding; a compression algorithm
Roger Hui – created J
Dave Hyatt – co-authored Mozilla Firefox
P. J. Hyett – cofounded GitHub
I
Miguel de Icaza – GNOME project leader, initiated Mono project
Roberto Ierusalimschy – Lua leading architect
Dan Ingalls – cocreated Smalltalk and Bitblt
Geir Ivarsøy – cocreated Opera web browser
Ken Iverson – APL, J
Toru Iwatani – created Pac-Man
J
Bo Jangeborg – ZX Spectrum games
Paul Jardetzky – authored server program for the first webcam
Rod Johnson – created Spring Framework, founded SpringSource
Stephen C. Johnson – yacc
Lynne Jolitz – 386BSD
William Jolitz – 386BSD
Bill Joy – BSD, csh, vi, cofounded Sun Microsystems
Robert K. Jung – created ARJ
K
Poul-Henning Kamp – MD5 password hash algorithm, FreeBSD GEOM and GBDE, part of UFS2, FreeBSD Jails, malloc and the Beerware license
Mitch Kapor – Lotus 1-2-3, founded Lotus Development Corporation
Phil Katz – created Zip (file format), authored PKZIP
Ted Kaehler – contributions to Smalltalk, Squeak, HyperCard
Alan Kay – Smalltalk, Dynabook, Object-oriented programming, Squeak
Mel Kaye – LGP-30 and RPC-4000 machine code programmer at Royal McBee in the 1950s, famed as "Real Programmer" in the Story of Mel
Stan Kelly-Bootle – Manchester Mark 1, The Devil's DP Dictionary
John Kemeny – cocreated BASIC
Brian Kernighan – cocreated AWK (being the K in that name), authored ditroff text-formatting tool
Gary Kildall – CP/M, MP/M, BIOS, PL/M, also known for work on data-flow analysis, binary recompilers, multitasking operating systems, graphical user interfaces, disk caching, CD-ROM file system and data structures, early multi-media technologies, founded Digital Research (DRI)
Tom Knight – Incompatible Timesharing System
Jim Knopf – a.k.a. Jim Button, author PC-File flatfile database; cocreated shareware
Donald E. Knuth – TeX, CWEB, Metafont, The Art of Computer Programming, Concrete Mathematics
Andrew R. Koenig – co-authored books on C and C++ and former Project Editor of ISO/ANSI standards committee for C++
Gennady Korotkevich - Competitive programmer, first to break the 3900 barrier on Codeforces
Cornelis H. A. Koster – Report on the Algorithmic Language ALGOL 68, ALGOL 68 transput
L
Andre LaMothe – created XGameStation, one of world's first video game console development kits
Leslie Lamport – LaTeX
Butler Lampson – QED original co-author
Peter Landin – ISWIM, J operator, SECD machine, off-side rule, syntactic sugar, ALGOL, IFIP WG 2.1 member
Tom Lane – main author of libjpeg, major developer of PostgreSQL
Sam Lantinga – created Simple DirectMedia Layer (SDL)
Dick Lathwell – codeveloped APL\360
Chris Lattner – main author of LLVM project
Samuel J. Leffler – BSD, FlexFAX, LibTIFF, FreeBSD Wireless Device Drivers
Rasmus Lerdorf – original created PHP
Michael Lesk – Lex
Gordon Letwin – architected OS/2, authored High Performance File System (HPFS)
Jochen Liedtke – microkernel operating systems Eumel, L3, L4
Charles H. Lindsey – IFIP WG 2.1 member, Revised Report on ALGOL 68
Håkon Wium Lie – co-authored Cascading Style Sheets
Mike Little - co-authored WordPress
Yanhong Annie Liu – programming languages, algorithms, program design, program optimization, software systems, optimizing, analysis, and transformations, intelligent systems, distributed computing, computer security, IFIP WG 2.1 member
Robert Love – Linux kernel developer
Ada Lovelace – first programmer (of Charles Babbages' Analytical Engine)
Al Lowe – created Leisure Suit Larry series
David Luckham – Lisp, Automated theorem proving, Stanford Pascal Verifier, Complex event processing, Rational Software cofounder (Ada compiler)
Hans Peter Luhn – hash-coding, linked list, searching and sorting binary tree
M
Khaled Mardam-Bey – created mIRC (Internet Relay Chat Client)
Simon Marlow – Haskell developer, book author; co-developer: Glasgow Haskell Compiler, Haxl remote data access library
Robert C. Martin – authored Clean Code, The Clean Coder, leader of Clean Code movement, signatory on the Agile Manifesto
John Mashey – authored PWB shell, also called Mashey shell
Yukihiro Matsumoto "Matz" – Ruby language
Conor McBride – researches type theory, functional programming; cocreated Epigram (programming language) with James McKinna; member IFIP Working Group 2.1 on Algorithmic Languages and Calculi
John McCarthy – Lisp, ALGOL, IFIP WG 2.1 member, artificial intelligence
Craig McClanahan – original author Jakarta Struts, architect of Tomcat Catalina servlet container
Daniel D. McCracken – professor at City College and authored Guide to Algol Programming, Guide to Cobol Programming, Guide to Fortran Programming (1957)
Scott A. McGregor – architect and development team lead of Microsoft Windows 1.0, co-authored X Window System version 11, and developed Cedar Viewers Windows System at Xerox PARC
Douglas McIlroy – macros, pipes and filters, concept of software componentry, Unix tools (spell, diff, sort, join, graph, speak, tr, etc.)
Marshall Kirk McKusick – Berkeley Software Distribution (BSD), work on FFS, implemented soft updates
Sid Meier – author, Civilization and Railroad Tycoon, cofounded MicroProse
Bertrand Meyer – Eiffel, Object-oriented Software Construction, design by contract
Bob Miner – co-created Oracle Database, cofounded Oracle Corporation
Jeff Minter – psychedelic, and often llama-related video games
James G. Mitchell – WATFOR compiler, Mesa (programming language), Spring (operating system), ARM architecture
Arvind Mithal – formal verification of large digital systems, developing dynamic dataflow architectures, parallel computing programming languages (Id, pH), compiling on parallel machines
Petr Mitrichev – competitive programmer
Cleve Moler – co-authored LINPACK, EISPACK, and MATLAB
Lou Montulli – created Lynx browser, cookies, the blink tag, server push and client pull, HTTP proxying, HTTP over SSL, browser integration with animated GIFs, founding member of HTML working group at W3C
Bram Moolenaar – authored text-editor Vim
David A. Moon – Maclisp, ZetaLisp
Charles H. Moore – created Forth language
Roger Moore – co-developed APL\360, created IPSANET, cofounded I. P. Sharp Associates
Matt Mullenweg – co-authored WordPress
Boyd Munro – Australian developed GRASP, owns SDI, one of earliest software development companies
Mike Muuss – authored ping, network tool to detect hosts
N
Patrick Naughton – early Java designer, HotJava
Peter Naur (1928–2016) – Backus–Naur form (BNF), ALGOL 60, IFIP WG 2.1 member
Fredrik Neij – cocreated The Pirate Bay
Graham Nelson – created Inform authoring system for interactive fiction
Greg Nelson (1953–2015) – satisfiability modulo theories, extended static checking, program verification, Modula-3 committee, Simplify theorem prover in ESC/Java
Klára Dán von Neumann (1911–1963) – principal programmer for the MANIAC I
Maurice Nivat (1937–2017) – theoretical computer science, Theoretical Computer Science journal, ALGOL, IFIP WG 2.1 member
Peter Norton – programmed Norton Utilities
Kristen Nygaard (1926–2002) – Simula, object-oriented programming
O
Ed Oates – cocreated Oracle Database, cofounded Oracle Corporation
Martin Odersky – Scala
Peter O'Hearn – separation logic, bunched logic, Infer Static Analyzer
Jarkko Oikarinen – created Internet Relay Chat (IRC)
Andrew and Philip Oliver, the Oliver Twins – many ZX Spectrum games including Dizzy
John Ousterhout – created Tcl/Tk
P
Keith Packard – X Window System
Larry Page – cofounded Google, Inc.
Alexey Pajitnov – created game Tetris on Electronika 60
Seymour Papert – Logo (programming language)
David Park (1935–1990) – first Lisp implementation, expert in fairness, program schemas, bisimulation in concurrent computing
Mike Paterson – algorithms, analysis of algorithms (complexity)
Tim Paterson – authored 86-DOS (QDOS)
Markus Persson – created Minecraft
Jeffrey Peterson – key free and open-source software architect, created Quepasa
Charles Petzold – authored many Microsoft Windows programming books
Simon Peyton Jones – functional programming, Glasgow Haskell Compiler, C--
Rob Pike – wrote first bitmapped window system for Unix, cocreated UTF-8 character encoding, authored text editor sam and programming environment acme, main author of Plan 9 and Inferno operating systems, co-authored Go (programming language)
Kent Pitman – technical contributor to the ANSI Common Lisp standard
Robin Popplestone – COWSEL (renamed POP-1), POP-2, POP-11 languages, Poplog IDE; Freddy II robot
Tom Preston-Werner – cofounded GitHub
R
Theo de Raadt – founding member of NetBSD, founded OpenBSD and OpenSSH
Brian Randell – ALGOL 60, software fault tolerance, dependability, pre-1950 history of computing hardware
T. V. Raman – specializes in accessibility research (Emacspeak, ChromeVox (screen reader for Google Chrome)
Jef Raskin – started the Macintosh project in Apple Computer, designed Canon Cat computer, developed Archy (The Humane Environment) program
Eric S. Raymond – Open Source movement, authored fetchmail
Hans Reiser – created ReiserFS file system
John Resig – creator and lead developed jQuery JavaScript library
Craig Reynolds – created boids computer graphics simulation
John C. Reynolds – continuations, definitional interpreters, defunctionalization, Forsythe, Gedanken language, intersection types, polymorphic lambda calculus, relational parametricity, separation logic, ALGOL
Reinder van de Riet – Editor: Europe of Data and Knowledge Engineering, COLOR-X event modeling language
Dennis Ritchie – C, Unix, Plan 9 from Bell Labs, Inferno
Ron Rivest – cocreated RSA algorithm (being the R in that name). created RC4 and MD5
John Romero – first-person shooters Doom, Quake
Blake Ross – co-authored Mozilla Firefox
Douglas T. Ross – Automatically Programmed Tools (APT), Computer-aided design, structured analysis and design technique, ALGOL X
Guido van Rossum – Python
Philip Rubin – articulatory synthesis (ASY), sinewave synthesis (SWS), and HADES signal processing system.
Jeff Rulifson – lead programmer on the NLS project
Rusty Russell – created iptables for linux
Steve Russell – first Lisp interpreter; original Spacewar! graphic video game
Mark Russinovich – Sysinternals.com, Filemon, Regmon, Process Explorer, TCPView and RootkitRevealer
S
Bob Sabiston – Rotoshop, interpolating rotoscope animation software
Muni Sakya – Nepalese software
Chris Sawyer – developed RollerCoaster Tycoon and the Transport Tycoon series
Cher Scarlett – Apple, Webflow, Blizzard Entertainment, World Wide Technology, and USA Today
Bob Scheifler – X Window System, Jini
Isai Scheinberg – IBM engineer, founded PokerStars
Bill Schelter – GNU Maxima, GNU Common Lisp
John Scholes – Direct functions
Randal L. Schwartz – Just another Perl hacker
Adi Shamir – cocreated RSA algorithm (being the S in that name)
Mike Shaver – founding member of Mozilla Organization
Cliff Shaw – Information Processing Language (IPL), the first AI language
Zed Shaw – wrote the Mongrel Web Server, for Ruby web applications
Emily Short – prolific writer of Interactive fiction and co-developed Inform version 7
Jacek Sieka – developed DC++ an open-source, peer-to-peer file-sharing client
Daniel Siewiorek – electronic design automation, reliability computing, context aware mobile computing, wearable computing, computer-aided design, rapid prototyping, fault tolerance
Ken Silverman – created Duke Nukem 3Ds graphics engine
Charles Simonyi – Hungarian notation, Bravo (the first WYSIWYG text editor), Microsoft Word
Colin Simpson – developed CircuitLogix simulation software
Rich Skrenta – cofounded DMOZ
David Canfield Smith – invented interface icons, programming by demonstration, developed graphical user interface, Xerox Star; Xerox PARC researcher, cofounded Dest Systems, Cognition
Matthew Smith – ZX Spectrum games, including Manic Miner and Jet Set Willy
Henry Spencer – C News, Regex
Joel Spolsky – cofounded Fog Creek Software and Stack Overflow
Quentin Stafford-Fraser – authored original VNC viewer, first Windows VNC server, client program for the first webcam
Richard Stallman – Emacs, GNU Compiler Collection (GCC), GDB, founder and pioneer of GNU Project, terminal-independent I/O pioneer on Incompatible Timesharing System (ITS), Lisp machine manual
Guy L. Steele Jr. – Common Lisp, Scheme, Java
Alexander Stepanov – created Standard Template Library
Christopher Strachey – draughts playing program
Ludvig Strigeus – created μTorrent, OpenTTD, ScummVM and the technology behind Spotify
Bjarne Stroustrup – created C++
Zeev Suraski – cocreated PHP language
Gerald Jay Sussman – Scheme
Herb Sutter – chair of ISO C++ standards committee and C++ expert
Gottfrid Svartholm – cocreated The Pirate Bay
Aaron Swartz – software developer, writer, Internet activist
Tim Sweeney – The Unreal engine, UnrealScript, ZZT
T
Amir Taaki – leading developer of Bitcoin project
Andrew Tanenbaum – Minix
Audrey "Autrijus" Tang – designed Pugs compiler–interpreter for Perl 6 (now Raku); Digital Affairs Minister, Taiwan 2022–2024
Simon Tatham – Netwide Assembler (NASM), PuTTY
Larry Tesler – the Smalltalk code browser, debugger and object inspector, and (with Tim Mott) the Gypsy word processor
Jon Stephenson von Tetzchner – cocreated Opera web browser
Avie Tevanian – authored Mach kernel
Ken Thompson – mainly designed and authored Unix, Plan 9 and Inferno operating systems, B and Bon languages (precursors of C), created UTF-8 character encoding, introduced regular expressions in QED and co-authored Go language
Simon Thompson – functional programming research, textbooks; Cardano domain-specific languages: Marlowe
Michael Tiemann – G++, GNU Compiler Collection (GCC)
Linus Torvalds – original author and current maintainer of Linux kernel and created Git, a source code management system
Andrew Tridgell – Samba, Rsync
Roy Trubshaw – MUD – together with Richard Bartle, created MUDs
Bob Truel – cofounded DMOZ
Alan Turing – mathematician, computer scientist and cryptanalyst
David Turner – SASL, Kent Recursive Calculator, Miranda, IFIP WG 2.1 member
V
Wietse Venema – Postfix, Security Administrator Tool for Analyzing Networks (SATAN), TCP Wrapper
Bernard Vauquois – pioneered computer science in France, machine translation (MT) theory and practice including Vauquois triangle, ALGOL 60
Pat Villani – original author FreeDOS/DOS-C kernel, maintainer of defunct Linux for Windows 9x distribution
Paul Vixie – BIND, Cron
Patrick Volkerding – original author and current maintainer of Slackware Linux Distribution
W
Eiiti Wada – ALGOL N, IFIP WG 2.1 member, Japanese Industrial Standards (JIS) X 0208, 0212, Happy Hacking Keyboard
John Walker – cofounded Autodesk
Larry Wall – Warp (1980s space-war game), rn, patch, Perl
Bob Wallace – author PC-Write word processor; considered shareware cocreator
Chris Wanstrath – cofounded GitHub, created the Atom (text editor) and the Mustache template system
John Warnock – created PostScript
Robert Watson – FreeBSD network stack parallelism, TrustedBSD project and OpenBSM
Joseph Henry Wegstein – ALGOL 58, ALGOL 60, IFIP WG 2.1 member, data processing technical standards, fingerprint analysis
Pei-Yuan Wei – authored ViolaWWW, one of earliest graphical browsers
Peter J. Weinberger – cocreated AWK (being the W in that name)
Jim Weirich – created Rake, Builder, and RubyGems for Ruby; popular teacher and conference speaker
Joseph Weizenbaum – created ELIZA
David Wheeler – cocreated subroutine; designed WAKE; co-designed Tiny Encryption Algorithm, XTEA, Burrows–Wheeler transform
Molly White – HubSpot; creator of Web3 Is Going Just Great
Arthur Whitney – A+, K
why the lucky stiff – created libraries and writing for Ruby, including quirky, popular Why's (poignant) Guide to Ruby to teach programming
Adriaan van Wijngaarden – Dutch pioneer; ARRA, ALGOL, IFIP WG 2.1 member
Bruce Wilcox – created Computer Go, programmed NEMESIS Go Master
Evan Williams – created and cofounded language Logo
Roberta and Ken Williams – Sierra Entertainment, King's Quest, graphic adventure game
Sophie Wilson – designed instruction set for Acorn RISC Machine, authored BBC BASIC
Dave Winer – developed XML-RPC, Frontier scripting language
Niklaus Wirth – ALGOL W, IFIP WG 2.1 member, Pascal, Modula-2, Oberon
Stephen Wolfram – created Mathematica
Don Woods – INTERCAL, Colossal Cave Adventure
Philip Woodward – ambiguity function, sinc function, comb operator, rep operator, ALGOL 68-R
Steve Wozniak – Breakout, Apple Integer BASIC, cofounded Apple Inc.
Will Wright – created the Sim City series, cofounded Maxis
William Wulf – BLISS system programming language + optimizing compiler, Hydra operating system, Tartan Laboratories
Y
Jerry Yang – co-created Yahoo!
Victor Yngve – authored first string processing language, COMIT
Nobuo Yoneda – Yoneda lemma, Yoneda product, ALGOL, IFIP WG 2.1 member
Z
Matei Zaharia – created Apache Spark
Jamie Zawinski – Lucid Emacs, Netscape Navigator, Mozilla, XScreenSaver
Phil Zimmermann – created encryption software PGP, the ZRTP protocol, and Zfone
Mark Zuckerberg – created Facebook
See also
List of computer scientists
List of computing people
List of members of the National Academy of Sciences (computer and information sciences)
List of pioneers in computer science
List of programming language researchers
List of Russian programmers
List of video game industry people (programming)
!
Programmers
Computer Programmers | List of programmers | Technology | 6,395 |
8,009,218 | https://en.wikipedia.org/wiki/Fibonacci%20numbers%20in%20popular%20culture | The Fibonacci numbers are a sequence of integers, typically starting with 0, 1 and continuing 1, 2, 3, 5, 8, 13, ..., each new number being the sum of the previous two. The Fibonacci numbers, often presented in conjunction with the golden ratio, are a popular theme in culture. They have been mentioned in novels, films, television shows, and songs. The numbers have also been used in the creation of music, visual art, and architecture.
Architecture
The sequence has been used in the design of a building, the Core, at the Eden Project, near St Austell, Cornwall, England.
Cinema
In The Phantom Tollbooth (1970), Milo (Butch Patrick) is given a set of numbers to identify in order to gain entry to the "Numbers Mine", and correctly answers noting that it is the Fibonacci sequence.
Along with the golden rectangle and golden spiral, the Fibonacci sequence is mentioned in Darren Aronofsky's independent film Pi (1998). They are used to find the name of God.
In The Da Vinci Code (2006), the numbers are used to unlock a safe. They are also placed out of order in a message to indicate that the message is also out of order (anagram).
In Mr. Magorium's Wonder Emporium (2007), Magorium hires accountant Henry Weston (Jason Bateman) after an interview in which he demonstrates knowledge of Fibonacci numbers.
In L: Change the World (2008), Near is seen arranging sugar cubes in a Fibonacci sequence.
In 21 (2008), the first seven numbers in the Fibonacci Sequence are drawn in icing on Ben's (Jim Sturgess) birthday cake. The 8th term, 21, is left out. Ben and Miles (Josh Gad) quickly figure it out.
In Nymphomaniac (2013), the character Seligman (Stellan Skarsgård) notes that when Joe (Charlotte Gainsbourg) loses her virginity, the boy who deflowers her does so in a sequence of thrusts that are Fibonacci numbers.
In Arrival (2016), character Ian Donnelly (Jeremy Renner) checks if the aliens have communicated with humans in any of the following approaches: "shapes, patterns, numbers, fibonacci".
Comic strips
In the February 8, 2009, edition of FoxTrot by Bill Amend, characters Jason and Marcus take one nacho from a bowl, one more nacho, then two nachos, three nachos, five nachos, eight nachos, etc., calling it 'Fibonacho.'
In a strip of Frazz by Jef Mallett, Frazz and a student are discussing her knitted hat. The student says, "Mom sewed one sparkly here and here. Two sparklies here. Three sparklies. Five sparklies. Eight sparklies. Thirteen..." To which Frazz replies, "Fibonacci sequins, of course."
Human development
John Waskom postulated that stages of human development followed the Fibonacci sequence, and that the unfolding psychology of human life would ideally be a "living proof" of the Golden Mean. This theory was originally developed and published by Norman Rose in two articles. The first article, which laid out the general theory, was entitled "Design and Development of Wholeness: Waskom's Paradigm." The second article laid out the applications and implications of the theory to the topic of moral development, and was entitled "Moral Development: The Experiential Perspective."
Literature
The Fibonacci sequence plays a small part in Dan Brown's bestselling novel (and film) The Da Vinci Code.
In Philip K. Dick's novel VALIS, the Fibonacci sequence (as well as the Fibonacci constant) are used as identification signs by an organization called the "Friends of God".
In the collection of poetry alfabet by the Danish poet Inger Christensen, the Fibonacci sequence is used to define the number of lines in each poem.
It was briefly included (and recognized by Charles Wallace Murry) in the television film adaptation of A Wrinkle in Time.
The Fibonacci sequence is frequently referenced in the 2001 book The Perfect Spiral by Jason S. Hornsby.
A youthful Fibonacci is one of the main characters in the novel Crusade in Jeans (1973). He was left out of the 2006 movie version, however.
The Fibonacci sequence and golden ratio are briefly described in John Fowles's 1985 novel A Maggot.
The Fibonacci sequence is explored in Emily Gravett's 2009 book The Rabbit Problem.
The Rabbit Problem is also described in Marina Lewycka's book Various Pets Alive and Dead.
Ice Station (1998), a novel by Australian writer Matthew Reilly, involves a partially completed access code, the remaining numbers of which can only be found by extrapolating a Fibonacci pattern.
The Fibonacci sequence is used by a serial killer to attract the protagonist Special Agent Pendergast in the Douglas Preston/Lincoln Child novel Two Graves (2012).
Eleanor Catton's novel The Luminaries (2013), winner of the 2013 Man Booker Prize, is structured around an inverse Fibonacci sequence, with each part of the book half the length of the one preceding it.
Music
Bollywood lyricist Vayu's song "Beat pe Booty" from the movie A Flying Jatt mentions the Fibonacci spiral in the lyrics:
Roll Karti Jaise Barrel
Fibonacci Wala Spiral
[When you twerk, you roll as a barrel. As if tracing out a Fibonacci's Spiral.]
Hip hop duo Black Star's song "Astronomy (8th Light)" from the 1998 album Mos Def & Talib Kweli are Black Star, features the Fibonacci sequence in the chorus:
Now everybody hop on the one, the sounds of the two
It's the third eye vision, five side dimension
The 8th Light, is gonna shine bright tonight
Tool's song "Lateralus" from the album of the same name features the Fibonacci sequence symbolically in the verses of the song. The syllables in the first verse count 1, 1, 2, 3, 5, 8, 5, 13, 13, 8, 5, 3. The missing section (2, 1, 1, 2, 3, 5, 8) is later filled in during the second verse. The time signatures of the chorus change from 9/8 to 8/8 to 7/8; as drummer Danny Carey says, "It was originally titled 9-8-7. For the time signatures. Then it turned out that 987 was the 16th number of the Fibonacci sequence. So that was cool."
Ernő Lendvai analyzes Béla Bartók's works as being based on two opposing systems, that of the golden ratio and the acoustic scale. In the third movement of Bartók's Music for Strings, Percussion and Celesta, the opening xylophone passage uses Fibonacci rhythm as such: 1:1:2:3:5:8:5:3:2:1:1.
The Fibonacci numbers are also apparent in the organisation of the sections in the music of Claude Debussy's Image, Reflections in Water, in which the sequence of keys is marked out by the intervals 34, 21, 13 and 8.
Italian composer and mathematical-physicist Matteo Sommacal wrote in 2002 the eight-movement suite Fibonacci's Piranhas, for piano 4, 5 and 6 hands, which makes an extensive use of the Fibonacci numbers for deriving and developing the whole melodic, rhythmic and harmonic structure of the piece.
Polish composer Krzysztof Meyer structured the values in his Trio for clarinet, cello and piano according to the Fibonacci sequence.
Fibonacci's name was adopted by a Los Angeles-based art rock group The Fibonaccis, that recorded from 1981 to 1987.
American musician BT also recorded a song titled "Fibonacci Sequence". The narrator in the song goes through all the numbers of the sequence from 1 to 21 (0 is not mentioned). The track appeared on a limited edition version of his 1999 album Movement in Still Life, and is also featured on the second disc of the Global Underground 013: Ibiza compilation mixed by Sasha.
Voiceover and recording artist Ken Nordine described Fibonacci numbers in a word jazz piece called "Fibonacci Numbers" on his album A Transparent Mask.
Australian electronic group Angelspit uses the Fibonacci in the song "Vermin". The lyrics start with, "1, 2 3 5 8, Who do we decapitate?" and continues through a few more iterations of the sequence.
Avant garde composer Elliott Sharp used Fibonacci numbers in his compositions.
Fred Frith composed an instrumental "Ruins" for the avant-rock group Henry Cow using Fibonacci numbers to establish beat and harmony.
Composer Dave Soldier's opera with Komar and Melamid, Naked Revolution, contains a soprano aria titled "Sing of Nature, Sing of Numbers" with lyrics and music based on the Fibonacci series, sung in character by Isadora Duncan.
In 2001, American musician Doctor Steel recorded the song "Fibonacci Sequence" from the album People of Earth.
In 2018, shortly before his death, Russian hip hop artist Detsl recorded the song "Fibonacci" (in English)
Visual arts
Artist Mario Merz made the Fibonacci sequence a recurring theme in his work. Examples are the Chimney of Turku Energia, in Turku, Finland, featuring the start of the Fibonacci sequence in 2 m high neon lights, and the representation of the first Fibonacci numbers with red neon lights on one face of the four-faced dome of the Mole Antonelliana in Turin, Italy, part of the artistic work Il volo dei Numeri ("Flight of the numbers").
Fibonacci numbers have also been used in knitting to create aesthetically appealing patterns.
The artist Martina Schettina uses Fibonacci numbers in her paintings. Her Mathemagic paintings were shown at the Museumsquartier Vienna in 2010.
Visual artist Marisa Ferreira used the Fibonacci numeral sequence to create the geometric shapes of her piece Rear Window, installed from February to August 2015 on the façade of Oslo Central Station, Norway. The artist used the sequence to express the walking pattern and rhythm of footsteps of pedestrian traffic in and out of the station.
Grace DeGennaro uses the Fibonacci sequence to accumulate the intricate patterns of dots in her paintings "to create a visible record of time."
German artist and architect Claus Bury used the Fibonacci numeral sequence in his sculptural projects.
Television
Fibonacci numbers appear in the series The Good Place, first in the main character Eleanor's horoscope on the day she dies and as the area code on the afterlife's neighborhood.
The scientist character Walter Bishop in the television show Fringe recites the Fibonacci sequence to fall asleep. It is later revealed to be the key sequence identifying a series of safe deposit boxes he had maintained.
Square One Televisions Mathnet series had a storyline that featured a parrot belonging to a deceased individual who was fascinated by the Fibonacci numbers. When "1, 1, 2, 3" is said in the parrot's presence, it responds "5, eureka!" This proves to be the key to solving the case: tiles in a garden wall are found to follow the Fibonacci sequence, with a secret compartment hidden behind the lone misplaced tile.
The Criminal Minds episode "Masterpiece" in season 4 features a serial killer who uses Fibonacci sequences to choose both the number of victims he kills at a given time, as well as the location of their hometowns.
Aliens use Fibonacci's sequence in the Taken episode "God's Equation".
In the Disney Channel TV show So Weird, the Fibonacci sequence is used to build a house. The house becomes a nexus for lost spirits. One character, Fiona, is given a choice to use it to free her father as well as the builder of the house, but ultimately chooses to free the spirits and destroys the nexus.
The Fibonacci sequence is a main plot theme in the 2012 television show Touch, produced by Fox Network and starring Kiefer Sutherland. It revolves around a number sequence 318 5296 3287 9.5 22 975 6 1188 1604 55124... and on. These numbers are calculated from using the Fibonacci sequence in some way to reveal patterns in both natural and artificial systems, essentially allowing the characters to predict the future.
In the CBS show Numb3rs episode "Thirteen", a Fibonacci sequence is embedded in a numeric code left behind by a serial killer.
On the animated TV show Adventure Time, the sequence of 8, 13, 21, is shown on the back of the Enchiridion in certain episodes.
In the Cartoon Network special The Powerpuff Girls: Dance Pantsed, one of the kidnapping victims is named Fibonacci Sequins (voiced by Ringo Starr).
In episode 11 of the Japanese anime series Aguu: Tensai Ningyou, a Fibonacci sequence is rapidly fired back-and-forth in a battle of wits between two archenemies.
In episode 14 of the Japanese anime adaptation of Banana Fish, the Fibonacci sequence is mentioned during an IQ test.
References
External links
Also published as
Math for Poets and Drummers – Rachael Hall surveys rhythm and Fibonacci numbers and also the Hemachandra connection. Saint Joseph's University, 2005.
Rachel Hall, Hemachandra's application to Sanskrit poetry, (undated; 2005 or earlier).
Fibonacci Numbers and The Golden Section in Art, Architecture and Music, which lists a number of academic sources.
Fibonacci numbers
Mathematics-related topics in popular culture | Fibonacci numbers in popular culture | Mathematics | 2,976 |
391,548 | https://en.wikipedia.org/wiki/Mean%20center%20of%20the%20United%20States%20population | The mean center of the United States population is determined by the United States Census Bureau from the results of each national census. The Bureau defines it as follows:
After moving roughly west by south during the 19th century, the shift in the mean center of population during the 20th century was less pronounced, moving west and south. Nearly 79% of the overall southerly movement happened between 1950 and 2000.
One occasional confusion is the misconception that the point splits the US population into two equal halves, such that half of Americans live east of the point, and the other half west of it, however, this is actually a property of the median center of US population, which is not weighted by geographic distance and lies in Gibson County, Indiana.
Location information since 1790
See also
Center of population
Median center of United States population
Geographic center of the United States
Geographic center of the contiguous United States
References
Demographic history of the United States
Center of population | Mean center of the United States population | Physics,Mathematics | 187 |
8,926,228 | https://en.wikipedia.org/wiki/Artelinic%20acid | Artelinic acid (or its salt, artelinate) is an experimental drug that is being investigated as a treatment for malaria. It is a semi-synthetic derivative of the natural compound artemisinin. Artelinic acid has a lower rate of neurotoxicity than the related artemisinin derivatives arteether and artemether, but is three times more toxic than artesunate. At present, artelinic acid seems unlikely to enter routine clinical use, because it offers no clear benefits over the artemesinins already available (artesunate and artemether). Artelinic acid has not yet been evaluated for use in humans.
References
Antimalarial agents
Benzoic acids
Organic peroxides
Trioxanes
Heterocyclic compounds with 3 rings | Artelinic acid | Chemistry | 162 |
29,622,014 | https://en.wikipedia.org/wiki/Cochran%E2%80%93Mantel%E2%80%93Haenszel%20statistics | In statistics, the Cochran–Mantel–Haenszel test (CMH) is a test used in the analysis of stratified or matched categorical data. It allows an investigator to test the association between a binary predictor or treatment and a binary outcome such as case or control status while taking into account the stratification. Unlike the McNemar test, which can only handle pairs, the CMH test handles arbitrary strata sizes. It is named after William G. Cochran, Nathan Mantel and William Haenszel. Extensions of this test to a categorical response and/or to several groups are commonly called Cochran–Mantel–Haenszel statistics. It is often used in observational studies in which random assignment of subjects to different treatments cannot be controlled but confounding covariates can be measured.
Definition
We consider a binary outcome variable such as case status (e.g. lung cancer) and a binary predictor such as treatment status (e.g. smoking). The observations are grouped in strata. The stratified data are summarized in a series of 2 × 2 contingency tables, one for each stratum. The i-th such contingency table is:
The common odds-ratio of the K contingency tables is defined as:
The null hypothesis is that there is no association between the treatment and the outcome. More precisely, the null hypothesis is and the alternative hypothesis is . The test statistic is:
It follows a chi-squared distribution asymptotically with 1 degree of freedom under the null hypothesis.
Subset stability
The standard odds- or risk ratio of all strata could be calculated, giving risk ratios , where is the number of strata. If the stratification were removed, there would be one aggregate risk ratio of the collapsed table; let this be .
One generally expects the risk of an event unconditional on the stratification to be bounded between the highest and lowest risk within the strata (or identically with odds ratios).
It is easy to construct examples where this is not the case, and is larger or smaller than all of for .
This is comparable but not identical to Simpson's paradox, and as with Simpson's paradox, it is difficult to interpret the statistic and decide policy based upon it.
Klemens
defines a statistic to be subset stable iff is bounded between and , and a well-behaved statistic as being infinitely differentiable and not dependent on the order of the strata.
Then the CMH statistic is the unique well-behaved statistic satisfying subset stability.
Related tests
The McNemar test can only handle pairs. The CMH test is a generalization of the McNemar test as their test statistics are identical when each stratum shows a pair.
Conditional logistic regression is more general than the CMH test as it can handle continuous variable and perform multivariate analysis. When the CMH test can be applied, the CMH test statistic and the score test statistic of the conditional logistic regression are identical.
Breslow–Day test for homogeneous association. The CMH test supposes that the effect of the treatment is homogeneous in all strata. The Breslow-Day test allows to test this assumption. This is not a concern if the strata are small e.g. pairs.
Notes
External links
Introduction to the Cochran-Mantel-Haenszel Test
Statistical tests for contingency tables
Epidemiology
Medical statistics
Bayesian statistics
Summary statistics for contingency tables | Cochran–Mantel–Haenszel statistics | Environmental_science | 719 |
24,385,435 | https://en.wikipedia.org/wiki/C16H21NO2 | The molecular formula C16H21NO2 (molar mass: 259.34 g/mol, exact mass: 259.1572 u) may refer to:
Nortilidine
Propranolol
Ramelteon
Troparil
Molecular formulas | C16H21NO2 | Physics,Chemistry | 53 |
24,129,448 | https://en.wikipedia.org/wiki/List%20of%20accelerator%20mass%20spectrometry%20facilities | The following list of accelerator mass spectrometry facilities includes research centers that employ accelerator mass spectrometry (AMS).
Accelerator mass spectrometry is a form of mass spectrometry that accelerates ions to extraordinarily high kinetic energies before mass analysis.
Facilities
Africa
iThemba Laboratory for Accelerator Based Sciences, Johannesburg, South Africa
Oceania
14UD The Australian National University, Canberra, Australia
SSAMS The Australian National University, Canberra, Australia
ANTARES 10MV, STAR 2MV, Sydney, Australia
Rafter Radiocarbon Laboratory, GNS Science, New Zealand
Chronos 14Carbon-Cycle Facility, UNSW, Australia.
North America
Accium BioSciences at Swedish Medical Center Cherry Hill, Seattle, WA
André E. Lalonde Accelerator Mass Spectrometry Laboratory (AEL AMS) at the University of Ottawa in Ottawa, Canada
Beta Analytic Accelerator Mass Spectrometry Facility in Miami, Florida
Center for Accelerator Mass Spectrometry (CAMS) at the Lawrence Livermore National Laboratory
Center for Applied Isotope Studies (CAIS) at University of Georgia.
DirectAMS (D-AMS) radiocarbon labs in Bothell, WA & Seattle, WA
Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan
Institute for Structure and Nuclear Astrophysics, The University of Notre Dame, Notre Dame, Indiana
Institute of Energy and the Environment Radiocarbon Laboratory at the Pennsylvania State University, University Park, Pennsylvania
MegaSIMS at the University of California, Los Angeles in Los Angeles, CA
National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) Facility at Woods Hole Oceanographic Institution
NSF - Arizona Accelerator Mass Spectrometry (AMS) Laboratory
Pharmaron ABS, Inc. in Germantown, Maryland
Purdue Rare Isotope Measurement Laboratory at Purdue University in West Lafayette, Indiana
Trace Element Accelerator Mass Spectrometer (TEAMS) at the Naval Research Laboratory in Washington, DC
W.M. Keck Carbon Cycle Accelerator Mass Spectrometry (KCCAMS) Facility at the University of California, Irvine
Asia
Inter University Accelerator Centre (IUAC), New Delhi 110067 .
Xi'an AMS Center
Tandem accelerator for Environmental Research and Radiocarbon Analysis (NIES-TERRA) of the National Institute for Environmental Studies (NIES), Tsukuba, Japan
BINP AMS Facility, Novosibirsk, Russia
National Taiwan University, Department of Geosciences, Taipei, Taiwan, R.O.C
Accelerator Unit for Radio isotope Studies (AURiS), Geoscience Division, Physical Research Laboratory, Ahmedabad, India.
China Institute for Radiation Protection, Taiyuan, China
Europe
Lancaster AMS-UK for trace actinides and radiocarbon at Lancaster University, England
Vilnius Radiocarbon AMS dating laboratory in Vilnius, Lithuania
Centre for Isotope Research on Cultural and Environmental heritage (CIRCE) , Mathematics and Physics Department , Università degli Studi della Campania "Luigi Vanvitelli", Caserta, Italy
CEREGE in Aix en Provence, France
LMC14 Laboratoire de mesure du carbone 14, at LSCE, Saclay, France
LSCE-ECHoMICADAS, at LSCE, Gif-sur-Yvette, France
14Chrono Centre for Climate, the Environment, and Chronology Queen's University Belfast, Northern Ireland
Bristol Radiocarbon Accelerator Mass Spectrometer at University of Bristol, England
RICH, Royal Institute for Cultural heritage, Brussels, Belgium
CologneAMS at University of Cologne, Germany
Hertelendi Laboratory of Environmental Studies at ATOMKI, Debrecen, Hungary
DREAMS at Dresden, Germany
Centre for Isotope Research Rijksuniversiteit Groningen, The Netherlands
Beta Analytic Europe in London, England
Tandem Laboratory at Uppsala University in Uppsala, Sweden
Lund Accelerator Mass Spectrometry Facility at Lund University, Sweden
RoAMS Laboratory of the "Horia Hulubei" National Institute for Physics and Nuclear Engineering Măgurele, Romania
AMS at the Maier-Leibnitz-Laboratory joint facility of Ludwig Maximilian University of Munich and Technical University of Munich, Germany
Oxford Radiocarbon Accelerator Unit, University of Oxford, United Kingdom
Poznan Radiocarbon Laboratory, Poland
Centre for Dating and Diagnostics (CEDAD), University of Salento, Italy
Centro Nacional de Aceleradores, CNA University of Sevilla, Spain
NERC Recognised Accelerator Mass Spectrometer at SUERC, Scotland
Vienna Environmental Research Accelerator at the University of Vienna, Austria
Ion Beam Physics Laboratory of the ETH Zurich and the Paul Scherrer Institute, Switzerland
National 1MV AMS Laboratory, TÜBİTAK Marmara Research Center Turkey
Nuclear Physics Institute, The Czech Academy of Sciences, Czech Republic
Closed Facilities
Eckert & Ziegler Vitalea Science AMS company based in Davis, California, closed in 2016.
External links
, compiled by Walter Kutschera (to the best of his knowledge), VERA Lab, Faculty of Physics, University of Vienna, Austria.
Mass spectronomy | List of accelerator mass spectrometry facilities | Physics,Chemistry | 1,021 |
12,701,886 | https://en.wikipedia.org/wiki/Brittle%20Power | Brittle Power: Energy Strategy for National Security is a 1982 book by Amory B. Lovins and L. Hunter Lovins, prepared originally as a Pentagon study and re-released in 2001 following the September 11 attacks. The book argues that the U.S. domestic energy infrastructure is very vulnerable to disruption, whether by accident or malice, often even more so than US technology is vulnerable to disruption of the imported oil supply. According to the authors, a resilient energy system is feasible, costs less, works better, and is favoured in the market, but is rejected by U.S. policy. In the preface to the 2001 edition, Lovins explains that these themes are still very current.
Vulnerability to large-scale failures
Lovins argues that the United States has for decades been running on energy that is "brittle" (easily shattered by accident or malice) and that this poses a grave and growing threat to national security, life, and liberty.
Lovins explains that this danger comes not from hostile ideology but from misapplied technology. The size, complexity, pattern, and control structure of the electrical power system makes it inherently vulnerable to large-scale failures. The same is true of the technologies that deliver coal, gas, and oil for running buildings, vehicles, and industries. Reliance on these delicately poised energy systems has unwittingly put at risk the entire American way of life.
Lovins' detailed research shows that these vulnerabilities are increasingly being exploited. Brittle Power documents many significant assaults on energy facilities, other than during a war, in 40 countries and within the United States, in some 24 states.
Resilient energy systems
Lovins claims that most energy utilities and governments are unsuccessfully trying to build high technical reliability into power plants so large that their cost of failure is unacceptable. A resilient energy supply system may instead consist of numerous, relatively small sustainable energy sources, each with a low individual cost of failure. Potentially these individual energy sources "are renewable: they harness the energy of the sun, wind, water, or farm and forestry wastes, rather than that of depletable fuels".
Central message
Amory B. and L. Hunter Lovins reiterated the main message of Brittle Power in "Terrorism and Brittle Technology", Chapter 3 in Albert H. Teich's book Technology and the Future (2003):
The foundation of a secure energy system is to need less energy in the first place, then to get it from sources that are inherently invulnerable because they're diverse, dispersed, renewable, and mainly local. They're secure not because they're American but because of their design. Any highly centralised energy system – pipelines, nuclear plants, refineries – invites devastating attack. But invulnerable alternatives don't, and can't, fail on a large scale.
Networked island-able microgrids
In his book Reinventing Fire (2011), Amory B. Lovins puts forward a vision of networked island-able microgrids where energy is generated locally from solar power, wind power, and other resources, and used by super-efficient buildings. When each building, or neighborhood, is generating its own power, with links to other “islands” of power, the security of the entire network is greatly enhanced. Lovins has said that in the face of hundreds of blackouts in 2005, Cuba reorganized its electricity transmission system into networked microgrids and cut the occurrence of blackouts to zero within two years, limiting damage even after two hurricanes. Denmark has performed tests of islanding a region ("cell") to maintain robustness with smaller local assets rather than large centralized ones.
See also
Major blackouts
Related publications
Related concepts
Further reading
Brittle Power has 1,200 references. It has been summarised and referred to in several other publications:
Lay summary.
Book chapter written for security professionals.
References
External links
Document ID: IC#4.
Document ID: E03-06.
1982 in the environment
Books by Amory Lovins
Books about energy issues
Electric power
Environmental non-fiction books | Brittle Power | Physics,Engineering | 846 |
866,752 | https://en.wikipedia.org/wiki/Extended%20order | Extended order is an economics and sociology concept introduced by Friedrich Hayek in his book The Fatal Conceit. Hayek describes an extended order as the outcome of a system that embraces specialization and trade, and he claims that it "constitutes an information gathering process, able to call up, and put to use, widely dispersed information that no central planning agency, let alone any individual, could know as a whole, possess or control." The result is an interconnected web where people can benefit from the actions and knowledge of those they don't know. This is possible and efficient, in Hayek's view, because a proper legal framework replaces trust, which is only practical in small circles of people who know each other socially. The extended order is at the heart of Hayek's thesis, in The Fatal Conceit, where he argues that "our civilization depends, not only for its origin but also for its preservation, on what can be precisely described only as the extended order of human cooperation, an order more commonly, if somewhat misleading, known as capitalism."
Development of the extended order in society
Hayek argues that the extended order "is a framework of institutions – economic, legal, and moral – into which we fit ourselves by obeying certain rules of conduct that we never made, and which we have never understood in the sense of which we understand how the things that we manufacture function." This "order resulted not from human design or intention but spontaneously: it arose from unintentionally conforming to certain traditional & largely moral practices, many of which men tend to dislike, whose significance they usually fail to understand, whose validity they cannot prove, and which have nonetheless fairly rapidly spread by means of an evolutionary selection – the comparative increase in population & wealth – of those groups that happened to follow them."
According to Hayek, the adoption of these practices by these groups, "increased their access to valuable information of all sorts, & enabled them to be 'fruitful, and multiply, and replenish the earth, and subdue it' (Genesis 1:28). This process is perhaps the least appreciated facet of human evolution."
Hayek argues that the extended order's formation "required individuals to change their 'natural' or instinctual' responses to others, something strongly resisted", whereas any and all "constraints on the practices of the small group, it must be emphasized & repeated, are hated." This is because man "knows so many objects that seem desirable but for which he is not permitted to grasp, and he cannot see how other beneficial features of his environment depend on the discipline to which he is forced to submit – a discipline forbidding him to reach out for these same appealing objects. Disliking these constraints so much, we can hardly be said to have selected them; rather, these constraints selected us: they enabled us to survive."
Hayek says that the evolutionary process of the extended order can be stimulated by increases in individual freedom and has even realized some of its greatest advances during times of anarchy, however it can (and quite often has throughout history) been hindered by government constraint. He continues: "Protection of several property, not the direction of its use by government, laid the foundations for the growth of the dense network of exchange of services that shaped the extended order." The extended order is "not a creation of man's reason but a distinct second endowment conferred on him by cultural evolution."
Hayek posits that, since it is not genetically transferred, the continuing cultural evolution of the extended order requires teaching and passing on to each new generation the prevailing traditions, customs, morality and rules. This cultural evolutionary requirement was also analyzed by Will and Ariel Durant who said: "Civilization is not inherited; it has to be learned and earned by each generation anew; if the transmission should be interrupted for one century, civilization would die, and we should be savages again."
See also
Catallactics
Free Market
Spontaneous order
References
External links
Austrian School
Friedrich Hayek
Self-organization
Systems theory
Libertarian theory
Human evolution
Economic sociology
Political science | Extended order | Mathematics | 838 |
32,031,460 | https://en.wikipedia.org/wiki/Proceedings%20of%20the%20Institution%20of%20Mechanical%20Engineers%2C%20Part%20N | The Proceedings of the Institution of Mechanical Engineers, Part N: Journal of Nanoengineering and Nanosystems is a peer-reviewed scientific journal covering nanoscale engineering, nanoscience, and nanotechnology. It was established in 2004 and is published by SAGE Publications on behalf of the Institution of Mechanical Engineers.
Abstracting and indexing
The journal is abstracted and indexed in Scopus, Compendex, and CSA's Advanced Polymers Abstracts, Composites Industry Abstracts, and Earthquake Engineering Abstracts.
References
External links
Engineering journals
English-language journals
Institution of Mechanical Engineers academic journals
Nanotechnology journals
Academic journals established in 2004
Quarterly journals
SAGE Publishing academic journals | Proceedings of the Institution of Mechanical Engineers, Part N | Materials_science | 134 |
19,232,416 | https://en.wikipedia.org/wiki/Dynamic%20scraped%20surface%20heat%20exchanger | The dynamic scraped surface heat exchanger (DSSHE) is a type of heat exchanger used to remove or add heat to fluids, mainly foodstuffs, but also other industrial products. They have been designed to address specific problems that impede efficient heat transfer. DSSHEs improve efficiency by removing fouling layers, increasing turbulence in the case of high viscosity flow, and avoiding the generation of crystals and other process by-products. DSSHEs incorporate an internal mechanism which periodically removes the product from the heat transfer wall. The sides are scraped by blades made of a rigid plastic material to prevent damage to the scraped surface.
Introduction
An applicable technologies for indirect heat transfer use tubes (shell-and-tube exchangers) or flat surfaces (plate exchangers). Their goal is to exchange the maximum amount of heat per unit area by generating as much turbulence as possible below given pumping power limits. Typical approaches to achieve this consist of corrugating the tubes or plates or extending their surface with fins. However, these geometry conformation technologies, the calculation of optimum mass flows and other turbulence related factors become diminished when fouling appears, obliging designers to fit significantly larger heat transfer areas. There are several types of fouling, including particulate accumulation, precipitation (crystallization), sedimentation, generation of ice layers, etc.
Another factor posing difficulties to heat transfer is viscosity. Highly viscous fluids tend to generate deep laminar flow, a condition with very poor heat transfer rates and high pressure losses involving a considerable pumping power, often exceeding the exchanger design limits. This problem becomes worsened frequently when processing non-newtonian fluids.
The DSSHE has been designed to face the aforementioned problems. They increase heat transfer by: removing the fouling layers, increasing turbulence in case of high viscosity flow, and avoiding the generation of ice and other process by-products.
Description
The dynamic scraped surface heat exchangers incorporate an internal mechanism which periodically removes the product from the heat transfer wall. The product side is scraped by blades attached to a moving shaft or frame. The blades are made of a rigid plastic material to prevent damage to the scraped surface. This material is FDA approved in the case of food applications.
Types
There are basically three types of DSSHEs depending on the arrangement of the blades:
Rotating, tubular DSSHEs. The shaft is placed parallel to the tube axis, not necessarily coincident, and spins at various frequencies, from a few dozen rpm to more than 1000 rpm. The number of blades oscillates between 1 and 4 and may take advantage of centrifugal forces to scrape the inner surface of the tube. Examples are the Waukesha Cherry-Burrell Votator II, Alfa Laval Contherm, Terlet Terlotherm and Kelstream's scraped surface heat exchanger. Another example is the HRS Heat Exchangers R Series or Sakura Seisakusho Ltd. Japan Onlator.
Reciprocating, tubular DSSHEs. The shaft is concentric to the tube and moves longitudinally without rotating. The frequency spans between 10 and 60 strokes per minute. The blades may vary in number and shape, from baffle-like arrangements to perforated disk configurations. An example is the HRS Heat Exchangers Unicus.
Rotating, plate DSSHEs. The blades wipe the external surface of circular plates arranged in series inside a shell. The heating/cooling fluid runs inside the plates. The frequency is about several dozen rpm. An example is the HRS Spiratube T-Sensation.
Evaluation
Computational fluid dynamics (CFD) techniques are the standard tools to analyse and evaluate heat exchangers and similar equipment. However, for quick calculation purposes, the evaluation of DSSHEs are usually carried out with the help of ad hoc (semi)empirical correlations based on the Buckingham π theorem:
Fa = Fa(Re, Re', n, ...)
for pressure loss and
Nu = Nu(Re, Re', Pr, Fa, L/D, N, ...)
for heat transfer, where Nu is the Nusselt number, Re is the standard Reynolds number based on the inner diameter of the tube, Re''' is the specific Reynolds number based on the wiping frequency, Pr is the Prandtl number, Fa is the Fanning friction factor, L is the length of the tube, D is the inner diameter of the tube, n'' is the number of blades and the dots account for any other relevant dimensionless parameters.
Applications
The range of applications covers a number of industries, including food, chemical, petrochemical and pharmaceutical. The DSSHEs are appropriate whenever products are prone to fouling, very viscous, particulate, heat sensitive or crystallizing.
See also
Pumpable ice technology
References
Related reading
Heat exchangers
Fouling | Dynamic scraped surface heat exchanger | Chemistry,Materials_science,Engineering | 993 |
62,189,939 | https://en.wikipedia.org/wiki/Jos%20de%20Villiers | Josias Eduard de Villiers (nicknamed Jos, Koelenhof; 27 December 1843 – 16 August 1898) was a Cape Colony and South African Republic surveyor, politician, and amateur astronomer. He surveyed the first neighborhood in Johannesburg, Randjeslaagte. He predicted that Johannesburg would become a city rather than disappearing like other ghost towns (as most South African civil servants of the era did), and De Villiers Street there is named after him.
Early life
From Stellenbosch, De Villiers was the second son of Jacob Isaac de Villiers by his first wife, Ester Elisabeth Johanna Hoffman. De Villiers grew up on Koelenhof farm and later in Stellenbosch, studying at the South African College and becoming a surveyor. In 1863, he was still in Cape Colony working as a surveyor, but shortly afterward left for the Orange Free State. In 1865, he was tasked with surveying the farms in Ladybrand, part of the so-called "Conquered Area" from the Free State-Basotho Wars. He settled in Boshof and represented the area from 1875 to 1882 in the Volksraad (Parliament) of the Free State. After the resolution of the long-running diamond fields dispute of the 1870s stemming from Sir Henry Barkly declaring the entire area British territory, the Free State appointed De Villiers to define its boundary with Griqualand West.
On the rand
By the time gold was discovered in the Witwatersrand, De Villiers had settled in the area. Sir Joseph Robinson, 1st Baronet surveyed mining claims on Langlaagte Farm where gold would first be found, and he also inspected the 600 plots that made up the spoil tip Randjeslaagte, the seed of Johannesburg, with the help of W.H.A. Pritchard between 19 October and 3 November 1886. The streets ran north to south and east to west artificially, with no regard to terrain, and were quite broad, countering the Transvaal government's expectation of a mere mining hamlet similar to Barberton or Pilgrim's Rest. His goal was to offer as many housing plots as possible to save money, while selling the corners as valuable business offices.
The massive influx of prospective miners as well as the first merchants led the city to contract with De Villiers for expansion from 600 to 986 plots. To this end, in April 1887, the two parts of Randjeslaagte were thus connected. At the time, the claims were not proving lucrative, and the Ford and Jeppe syndicate paying for the surveys was under pressure from residents to reduce mining activity. De Villier's street plan continued from southern Marshalltown, but at the end of Bree Street some streets remained unjoined in the "nod," but the plan was never to connect Randjeslaagte together. His plots continued west to Ferreirasdorp, but to the east the owners of plots in Randjeslaagte began auctioning off land on 8 June 1887 that would become the city's first upscale suburb, Doornfontein.
Last years
In 1895, De Villiers sold his property in Johannesburg to move to Cape Town and devote himself full-time to his hobby of astronomy. In August 1896, he joined an expedition to the island of Vadsøya in Norway to view an eclipse, using his surveying skills to set up their equipment. Two years later, he was one of 16 killed in a train crash in Mostert's Hoek coming back home from Vryburg, where he had been campaigning for the Parliament of the Cape of Good Hope as a candidate for the Afrikaner Bond. At the time of his death, he was working on building an elaborate observatory at his house, Ambleside, in Sea Point.
Personal life
De Villiers and his wife Christina Maria Elizabeth de Vos had three sons.
Sources
(en) Potgieter, D.J. (chief ed.) 1972. Standard Encyclopaedia of Southern Africa. Cape Town: Nasionale Opvoedkundige Uitgewery.
(af) Sandler, E.A. in Beyers, C.J. (chief ed.) (1981). Suid-Afrikaanse Biografiese Woordeboek, vol. IV. Durban: Butterworth & Kie (Edms) Bpk.
(af) Van der Waal, Gerhard-Mark (1986). Van mynkamp tot metropolis. Die boukuns van Johannesburg, 1886–1940. Johannesburg: Chris van Rensburg Publikasies (Edms.) Beperk.
1898 deaths
1843 births
Cape Colony people
Orange Free State people
Astronomers
South African Republic politicians
Surveyors
Railway accident deaths in South Africa | Jos de Villiers | Astronomy | 971 |
3,240,984 | https://en.wikipedia.org/wiki/Stoll%C3%A9%20synthesis | The Stollé synthesis is a series of chemical reactions that produce oxindoles from anilines and α-haloacid chlorides (or oxalyl chloride).
The first step is an amide coupling, while the second step is a Friedel–Crafts reaction. An improved procedure has been developed.
See also
Indole
Hinsberg oxindole synthesis
References
Carbon-carbon bond forming reactions
Heterocycle forming reactions
Name reactions | Stollé synthesis | Chemistry | 91 |
55,223,022 | https://en.wikipedia.org/wiki/Rhizopus%20stolonifer | Rhizopus stolonifer is commonly known as black bread mold. It is a member of Zygomycota and considered the most important species in the genus Rhizopus. It is one of the most common fungi in the world and has a global distribution although it is most commonly found in tropical and subtropical regions. It is a common agent of decomposition of stored foods. Like other members of the genus Rhizopus, R. stolonifer grows rapidly, mostly in indoor environments.
History
This fungus was first discovered by the German scientist Christian Gottfried Ehrenberg in 1818 as Rhizopus nigricans. The name was changed in 1902 to Rhizopus stolonifer by the French mycologist J. P. Vuillemin.
Habitat and ecology
Rhizopus stolonifer has a cosmopolitan distribution and is found on all types of mouldy materials. It is often one of the first molds to appear on stale bread. It can exist in the soil as well as in the air. A variety of natural substrata are colonized by this species because R. stolonifer can tolerate broad variations in the concentration of essential nutrients and can use carbon and nitrogen combined in diverse forms.
In the laboratory, this fungus grows well on different media, including those that contain ammonium salts or amino compounds. However, R. stolonifer will not grow on Czapek's agar because it cannot utilize nitrogen in the form of nitrate. Rhizopus lives in hyphae and matured spores.
Growth and physiology
This species is known as a saprotroph and plays an important role in the early colonization of substrata in soil. Nonetheless, it can also behave as a parasite of plant tissues causing a rot of vegetables and fruits. Like other species of Rhizopus, R. stolonifer grows rapidly and spreads by means of the stolons. The stolons provide an aerial structure for the growth of the mycelium and the occupation of large areas. They can climb vertically as well as horizontally. Rhizopus species periodically produce rhizoids, which anchor it to the substrate and unbranched aerial sporangiophores. Sporangiophores of R. stolonifer can be up to 2.5 mm long and about 20 μm in diameter. The spores are shaped differently depending on the available nutrients. They can be ovate, polygonal or angular. The optimal temperature for growth varies between 25 and 30 °C. The thermal death point, which is defined as the lowest temperature that can kill all cells in ten minutes, is 60 °C. Rhizopus stolonifer can grow in acidic environments with a pH of as low as 2.2. The pH range can vary from 2.2 to 9.6. Ultraviolet irradiation can delay spore germination.
Reproduction
Rhizopus stolonifer can reproduce asexually and sexually. It is a heterothallic species. Sexual reproduction occurs when compatible haploid mating types in the form of hyphae make contact with each other, producing diploid zygospores. The sporangiophore contains both '+' and '−' mating type strains in the form of sporangiospores. Meiosis is delayed until the germination of the zygospores. The gametogenia often differ in size, regardless of mating type. This difference in size is not due to sex but presumably due to nutrition.
Disease and prevention
The disease caused by this fungus occurs mainly on ripe fruits, such as strawberries, melon and peach, which are more susceptible to wounds and have a higher sugar content. R. stolonifer can also cause soft rot of many vegetables, flowers, bulbs, corms, and seeds. After a couple of days, the infected fruits become soft and release juices with an acidic odour. When the humidity and temperature are favourable, the mycelial growth occurs rapidly at the surface of the infected fruit and the disease causes the development of long mycelial stolons with black sporangia and spores. When the fungus germinates, it produces different kinds of esterases, including cutinase, which help the fungus to penetrate the plant cell wall. Once spores germinate and puncture the cell wall, various enzymes are released to break down glucose, fructose, sucrose, and other sugars, producing fumaric acid, lactic acid, and ethanol. The disease can also affect other adjacent healthy fruits when distributed by wind or insect activity.
Some species of Syncephalis can reduce the asexual reproduction of R. stolonifer and therefore may delay or even prevent the post-harvest disease caused by this fungus. Fengycin, which is an anti-fungal complex, also induces the fungal cell death via necrosis and apoptosis. The treatment of sweet potatoes with sodium orthophenyl phenol (Stopmold B) and dichloran (Botran W) have effectively reduced storage rot.
Rhizopus stolonifer is an opportunistic agent of disease and hence will only cause infection in people with a weakened immunity. Zygomycosis is the main disease that might be caused by this fungus in humans and while it is not entirely understood yet, this disease is very dangerous and can be fatal. More commonly, Rhizopus stolonifer may cause respiratory infections, sinusitis, and otomycosis. The action of smelling spoiled food may be a source of inhalation exposure to the mold.
Importance
Rhizopus stolonifer is important economically as an agent of post-harvest storage decay.
While Saccharomyces cerevisiae is the most important source of industrial alcohol, R. stolonifer and other species of Rhizopus also produce ethyl alcohol which is the most important fermentation product. Rhizopus stolonifer is also used commercially to manufacture fumaric acid and lactic acid of high purity. The presence of zinc reduces the amount of fumaric acid produced by the fungus.
References
Food microbiology
Mucoraceae
Fungi described in 1818
Fungus species | Rhizopus stolonifer | Biology | 1,302 |
15,105,320 | https://en.wikipedia.org/wiki/Iron%20%26%20Steel%20Museum%20of%20Alabama | The Iron & Steel Museum of Alabama, also known as the Tannehill Museum, is an industrial museum that demonstrates iron production in the nineteenth-century Alabama located at Tannehill Ironworks Historical State Park in McCalla, Tuscaloosa County, Alabama. Opened in 1981, it covers .
The museum is an interpretive center focusing on 19th-century iron-making technology. It features an extensive collection of machinery and other iron industry artifacts spanning from the time of the American Civil War until the 1960s, including belt-driven machines, a reconstruction of an 1870s machine shop, and four steam engines. The collection also houses over ten thousand artifacts and other items sourced from archaeological digs at various iron-making sites in Alabama such as the Roupes Valley Ironworks, and from the Alabama Department of Archives and History, the Henry Ford Museum, and the Washington Navy Yard. The collection includes rare steam engines, forge cams and war materials manufactured at the CS Naval Gun Works at Selma, Alabama.
In the museum, the collections and displays feature both belt-driven machines and the nineteenth century iron-making tools and products. The museum preserves more than 10,000 historical relics, including collections from the Washington Navy Yard and the Henry Ford Museum, as well as rare iron-making machinery from the Tredegar Ironworks from Virginia. The displayed ironworks show how iron making developed during the period from the Civil war to the 1960s. By visiting the museum, visitors can understand how iron making in this area grows into the later Birmingham District. This site preserves and demonstrates thousands of artefacts from archaeological digs in this area, showing the previous human activities in Alabama from the end of the Civil war to the middle of the 20 centuries. On top of that, 16 slave cabins have also been unearthed on the site in more recent excavations. The museum is connected with the best preserved furnaces at Tannehill Ironworks by the Tram Track Hiking Trail. Various interactive displays are available in the museum, which can enable the visitors to go back into the historical environments in the nineteenth-century Alabama. Visitors can follow the timeline of industrial growth to trace how iron trade developed from the ancient Egypt to modern Fairfield Works in Birmingham. The Tannehill Learning Centre currently offers educational programmes and tours to school children in this region. Museum visitors are provided with field trips during the spring and fall.
The museum underwent a major renovation of its exhibits in 2004–05. The site also has a 30-seat theatre which plays a short video on the park's history.
History of Iron and steel in Alabama
Post-war decades: From 1860s to 1880s
Since the Civil War, North Alabama became one of the country's leading iron and steel manufacturers. The Birmingham District was particularly well positioned to be an iron-and-steel production centre in the southern United States. The development of Alabama's iron and steel industry was primarily stimulated by the abundance of raw materials; coal, iron ore, limestone, and dolomite. The most powerful and profitable companies in North Alabama were those which had direct control over mines, as well as other facilities necessary for extracting and assembling raw materials, such as blast furnaces. Being dependent on raw materials and relevant infrastructural facilities, iron and steel makers expanded the furnaces in Alabama. Those manufacturers also attempted to incorporate new charging machines to increase the overall production of iron. Since iron and steel production was a resource-intensive industry this required powerful iron and steel manufacturing enterprises to hold a control over the regional railroads in Alabama. A typical example was the Woodward Iron Company whose holdings were mostly linked by a company-owned railroad. This railroad originally measured 12 miles in length but the company extended it outward from its blast furnaces, to its quarries of limestone and dolomite, and further to its coal mines and ore mines.
In the late 1800s
In the late 1800s, with the large investments financed by northern bankers and southern investors, as well as the technological expertise provided by northern and mid-western engineers, the iron and steel industry began to flourish in Birmingham, Alabama. In addition, the growth of Alabama's iron and steel industry was further facilitated by the influx of a large labour force at that time. During the last decades of the nineteenth century, Alabama's agricultural sector was mainly dominated by the economic models of sharecropping and tenant farming. This tenancy system encompassed over 60 percent of the farming population in Alabama; however, under its influence, landless farmers had to suffer from a legacy of illiteracy and poverty. Driven by poverty, many labourers, including unemployed and impoverished freedmen and white people, began to search for jobs in the iron-and-steel manufacturing industry, which was considered to be a more attractive alternative to sharecropping and tenant farming. Moreover, the introduction of convict-lease system also provided Alabama's iron and steel manufacturers with abundant cheap labour. The convict-lease system functioned in the state and counties of Alabama between 1875 and 1928, through which iron manufacturers paid to the local governments in exchange for prison labour. As regulated by the system, prisoners had to work for the companies that leased them from the governments. Until its abolition in 1928, the convict-lease system had provided iron manufacturers, owners of coal mines, and other enterprises in Alabama with a substantial number of prisoners as cheap labourers. At the end of the nineteenth century, due to the region's abundant geographical resources coupled with its low raw-material assembly costs, Alabama experienced a period of rocket development.
In the early 1900s
At the beginning of the twentieth century, as steel production became more dependent on the use of electric arc furnace technology in mini-mill environments, the convenient transportation of scrap metal became a competitive advantage of manufacturers, so the availability of geographical resources was no longer the most significant driving force for iron-and-steel production growth. The Birmingham area began to invest in building the earliest mini-mills, and continued to have a strong foundry emphasis, attracting many large cast-iron pipe producers, such as American Cast Iron Pipe Company. Headquartered in Birmingham in 1905, American Cast Iron Pipe Company, with its 2,100 acre site and 2,400 employees at its operations, became the world's largest iron pipe casting plant. With advanced expertise and the latest technological innovations, Birmingham furnaces produced millions of tons of pig iron from 1990s to 1970s. A half of the produced pig iron was used for steel production, and the other half was sold as foundry iron. This trend reflected that the region's iron ore was of poor quality, so manufacturers had difficulties in extracting it. This is a geological factor that limited the further development of Alabama's iron and steel industry, despite the help of advanced technology and innovative smelting practices.
Origins and development of the museum
The growth of Alabama's iron and steel industry was significantly influenced by Tannehill iron-making practices, such as using distilled coal residues as a furnace fuel, making early experimentation with coke, and reducing red iron ore from Red Mountain in a blast furnace. Due to the significant role that Tannehill pays in Alabama's iron and steel industry, the Alabama Central District of Civitan International and the representatives of the University of Alabama first proposed in the late 1960s that a state park should be built to preserve the site of Tannehill Ironworks, the birthplace of the Birmingham Iron industry. The proposal was approved by the state in 1969, and in the following year 1970, the Tannehill Historical State Parkopened to the public. There are more than 45 historical buildings in this state park, including the May Plantation Cotton Gin House, the John Wesley Hall Gristmill, as well as a collection of log cabins that trace back to the nineteenth century. Among the efforts to preserve the historical buildings and Tannehill artifacts, the Iron and Steel Museum of Alabama was built, and it opened in 1981. At present, the Tannehill Ironworks state park has been listed on the National Register of Historic Places and the Civil War Discovery Trail. In particular, the museum demonstrates how 13 iron manufacturers and 6 rolling mills worked to produce iron during the Civil war, making the Tannehill Ironworks among the best-preserved and oldest historical sites in the Southeastern part of this country. From 2004 to 2005, the museum had a significant make-over to introduce more new exhibits to the site, including an old rice-plantation-owned power source, and one of the oldest steam engines in this country. In 2017, Tannehill Ironworks, containing the Iron and Steel Museum of Alabama, became one of the six Birmingham historical sites which contributed to the creation of the Birmingham Industrial Heritage Trail. More recently, the Tannehill Furnace memorial park has become one of the most visited sites in Alabama, and the number of visitors each year exceeds 425,000. This is mainly due to the park's organisation of a variety of outdoor events and activities; for example, the Trade Days event is organised monthly from March to November each year, and visitors also have an opportunity to participant in a Civil War battle re-enactment.
Buildings and displays
Buildings
The museum has several functional areas, with the main museum building covering over 13,000 square feet. The displays at the main museum building contains iron-industry content as well as a wide variety of archaeological artifacts. In addition, the museum also houses the Walter B. Jones Centre for Industrial Archaeology and includes an exhibit centre, the 1858 May Plantation Cotton Gin House, a 30-seat theatre, as well as a gift shop. The exhibition centre displays preserved Birmingham's iron-and-steel industrial artifacts over the period from 1930s to the 1960s.
Main museum displays
To show the visitors how Birmingham's iron industry developed, the main museum displays a wide range of Tannehill artifacts that have survived. Visitors, through paying a visit to the museum, can learn from the graphic exhibits how iron was made by 13 different iron companies and six rolling mills and how Alabama's iron-making industry made this state the arsenal of the Confederacy. Although Alabama's iron and steel industry experienced rapid growth during the post-war decades, Alabama's iron production had already occupied a central position in the country's iron supply before the war ended. In the last two years of the Civil war, iron produced by Alabama furnaces accounted for 70% of the Confederate iron supply. To demonstrate the significant role Alabama played during the war , the museum displays a large number of wartime ironworks, including cookware, rifles and other weapons used by US soldiers (e.g. a 52 Cal. U.S. Spencer Repeater), cast-iron water pipes, CS artillery projectiles, the original parts of the Six Mile Bloomery Forge manufactured in 1860s, as well as a part of the Steve Phillips Collection. Notably, the artillery shells manufactured from 1862 to 1865 at the Naval Gun Works are also preserved in this museum, and this exhibition is considered as the South's largest collection of artillery shells. In addition to the wartime iron relics, the museum preserves and demonstrates substantial numbers of historical artifacts that have witnessed the development of Alabama's iron and steel industry, such as a cast iron water pipe made in Birmingham during the 1880s.
The Iron and Steel Museum of Alabama not only displays iron relics but also preserves archaeological artifacts uncovered in this region. The site houses Walter B. Jones Centre for Industrial Archaeology, a state geologist and archeologist who devoted his lifetime to investigating Alabama's mineral and fossil fuel resources (Garrison, 2001) His geological and archaeological works are well preserved by many museums and historical institutions, including the University of Alabama's Jones Museum at Moundville Archaeological Park, as well as the Iron and Steel Museum of Alabama. In addition to the preservation of the archaeological works written by Walter Jones, the museum is further famous for its conservation of more than 10,000 archaeological artifacts that were discovered from 8 major on-site archaeological investigations from 1956 to 2008. It is noteworthy that the main museum building also houses a small research library. In this library, those who are interested in investigating the iron-making history in this country (e.g. historical researchers, scholars, and students) can find many historical archives, published materials, records, as well as first-hand accounts.
See also
List of museums in Alabama
References
External links
Museums established in 1981
Historic American Engineering Record in Alabama
History of Alabama
Industry museums in Alabama
Museums in Tuscaloosa County, Alabama
1981 establishments in Alabama
History of metallurgy | Iron & Steel Museum of Alabama | Chemistry,Materials_science | 2,529 |
56,938,737 | https://en.wikipedia.org/wiki/Difluorophosphoric%20acid | Difluorophosphoric acid is an inorganic compound with the formula . It is a mobile colorless strongly fuming liquid. The acid has limited applications, in part because it is thermally and hydrolytically unstable. Difluorophosphoric acid is corrosive to glass, fabric, metals and living tissue.
A method to make pure difluorphosphoric acid involves heating phosphoryl fluoride with fluorophosphoric acid and separating the product by distillation:
It is prepared by hydrolysis of phosphoryl fluoride:
Further hydrolysis gives fluorophosphoric acid:
Complete hydrolysis gives phosphoric acid:
The salts of difluorophosphoric acid are known as difluorophosphates.
References
Oxohalides
Phosphorus halides
Fluoro complexes | Difluorophosphoric acid | Chemistry | 181 |
62,271,137 | https://en.wikipedia.org/wiki/Phenylacetyl-CoA | Phenylacetyl-CoA (C29H42N7O17P3S) is a form of acetyl-CoA formed from the condensation of the thiol group from coenzyme A with the carboxyl group of phenylacetic acid.
Its molecular-weight is 885.7 g/mol. and IUPAC name is S-[2-[3-[[(2R)-4-[[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-4-hydroxy-3-phosphonooxyoxolan-2-yl]methoxy-hydroxyphosphoryl]oxy-hydroxyphosphoryl]oxy-2-hydroxy-3,3-dimethylbutanoyl]amino]propanoylamino]ethyl] 2-phenylethanethioate. It is formed via the actions of Phenylacetate—CoA ligase.
Phenylacetyl-CoA is often produced via the reduction of ATP to AMP and the conversion of phenylacetate and CoA to diphosphate and Phenylacetyl-CoA.
ATP + phenylacetate + CoA → AMP + diphosphate + phenylacetyl-CoA
This reaction is catalyzed by phenylacetate-CoA ligase.
Phenylacetyl-CoA combines with water and quinone to produce phenylglyoxylyl-CoA and quinol via a phenylacetyl-CoA dehydrogenase reaction acting as an oxidoreductase.
Phenylacetyl-CoA inhibits choline acetyltransferase acting as a neurotoxin. It competes with acetyl-CoA.
References
Glycolysis
Cholinergics
Thioesters of coenzyme A | Phenylacetyl-CoA | Chemistry | 424 |
8,661,211 | https://en.wikipedia.org/wiki/Dielectric%20barrier%20discharge | Dielectric-barrier discharge (DBD) is the electrical discharge between two electrodes separated by an insulating dielectric barrier. Originally called silent (inaudible) discharge and also known as ozone production discharge or partial discharge, it was first reported by Ernst Werner von Siemens in 1857.
Process
The process normally uses high voltage alternating current, ranging from lower RF to microwave frequencies. However, other methods were developed to extend the frequency range all the way down to the DC. One method was to use a high resistivity layer to cover one of the electrodes. This is known as the resistive barrier discharge. Another technique using a semiconductor layer of gallium arsenide (GaAs) to replace the dielectric layer, enables these devices to be driven by a DC voltage between 580 V and 740 V.
Construction
DBD devices can be made in many configurations, typically planar, using parallel plates separated by a dielectric or cylindrical, using coaxial plates with a dielectric tube between them. In a common coaxial configuration, the dielectric is shaped in the same form as common fluorescent tubing. It is filled at atmospheric pressure with either a rare gas or rare gas-halide mix, with the glass walls acting as the dielectric barrier. Due to the atmospheric pressure level, such processes require high energy levels to sustain. Common dielectric materials include glass, quartz, ceramics and polymers. The gap distance between electrodes varies considerably, from less than 0.1 mm in plasma displays, several millimetres in ozone generators and up to several centimetres in CO2 lasers.
Depending on the geometry, DBD can be generated in a volume (VDBD) or on a surface (SDBD). For VDBD the plasma is generated between two electrodes, for example between two parallel plates with a dielectric in between. At SDBD the microdischarges are generated on the surface of a dielectric, which results in a more homogeneous plasma than can be achieved using the VDBD configuration At SDBD the microdischarges are limited to the surface, therefore their density is higher compared to the VDBD. The plasma is generated on top of the surface of an SDBD plate. To easily ignite VDBD and obtain a uniformly distributed discharge in the gap, a pre-ionization DBD can be used.
A particular compact and economic DBD plasma generator can be built based on the principles of the piezoelectric direct discharge. In this technique, the high voltage is generated with a piezo-transformer, the secondary circuit of which acts also as the high voltage electrode. Since the transformer material is a dielectric, the produced electric discharge resembles properties of the dielectric barrier discharge.
Manipulation of the encapsulated electrode and distributing the encapsulated electrode throughout the dielectric layer has been shown to alter the performance of the dielectric barrier discharge (DBD) plasma actuator. Actuators with a shallow initial electrode are able to more efficiently impart momentum and mechanical power into the flow.
Operation
A multitude of random arcs form in operation gap exceeding 1.5 mm between the two electrodes during discharges in gases at the atmospheric pressure . As the charges collect on the surface of the dielectric, they discharge in microseconds (millionths of a second), leading to their reformation elsewhere on the surface. Similar to other electrical discharge methods, the contained plasma is sustained if the continuous energy source provides the required degree of ionization, overcoming the recombination process leading to the extinction of the discharge plasma. Such recombinations are directly proportional to the collisions between the molecules and in turn to the pressure of the gas, as explained by Paschen's Law. The discharge process causes the emission of an energetic photon, the frequency and energy of which corresponds to the type of gas used to fill the discharge gap.
Applications
Usage of generated radiation
DBDs can be used to generate optical radiation by the relaxation of excited species in the plasma. The main application here is the generation of UV-radiation. Such excimer ultraviolet lamps can produce light with short wavelengths which can be used to produce ozone in industrial scales. Ozone is still used extensively in industrial air and water treatment. Early 20th-century attempts at commercial nitric acid and ammonia production used DBDs as several nitrogen-oxygen compounds are generated as discharge products.
Usage of the generated plasma
Since the 19th century, DBDs were known for their decomposition of different gaseous compounds, such as NH3, H2S and CO2. Other modern applications include semiconductor manufacturing, germicidal processes, polymer surface treatment, high-power CO2 lasers typically used for welding and metal cutting, pollution control and plasma displays panels, aerodynamic flow control... The relatively lower temperature of DBDs makes it an attractive method of generating plasma at atmospheric pressure.
Industry
The plasma itself is used to modify or clean (plasma cleaning) surfaces of materials (e.g. polymers, semiconductor surfaces), that can also act as dielectric barrier, or to modify gases applied further to "soft" plasma cleaning and increasing adhesion of surfaces prepared for coating or gluing (flat panel display technologies).
A dielectric barrier discharge is one method of plasma treatment of textiles at atmospheric pressure and room temperature. The treatment can be used to modify the surface properties of the textile to improve wettability, improve the absorption of dyes and adhesion, and for sterilization. DBD plasma provides a dry treatment that doesn't generate waste water or require drying of the fabric after treatment. For textile treatment, a DBD system requires a few kilovolts of alternating current, at between 1 and 100 kilohertz. Voltage is applied to insulated electrodes with a millimetre-size gap through which the textile passes.
An excimer lamp can be used as a powerful source of short-wavelength ultraviolet light, useful in chemical processes such as surface cleaning of semiconductor wafers. The lamp relies on a dielectric barrier discharge in an atmosphere of xenon and other gases to produce the excimers.
Water treatment
An additional process when using chlorine gas for removal of bacteria and organic contaminates in drinking water supplies. Treatment of public swimming baths, aquariums and fish ponds involves the use of ultraviolet radiation produced when a dielectric mixture of xenon gas and glass are used.
Surface modification of materials
An application where DBDs can be successfully used is to modify the characteristics of a material surface. The modification can target a change in its hydrophilicity, the surface activation, the introduction of functional groups, and so on. Polymeric surfaces are easy to be processed using DBDs which, in some cases, offer a high processing area.
Medicine
Dielectric barrier discharges were used to generate relatively large volume diffuse plasmas at atmospheric pressure and applied to inactivate bacteria in the mid 1990s. This eventually led to the development of a new field of applications, the biomedical applications of plasmas. In the field of biomedical application, three main approaches have emerged: direct therapy,
surface modification, and plasma polymer deposition. Plasma polymers can control and steer biological–biomaterial interactions (i.e. adhesion, proliferation, and differentiation) or inhibition of bacteria adhesion.
Aeronautics
Interest in plasma actuators as active flow control devices is growing rapidly due to their lack of mechanical parts, light weight and high response frequency.
Properties
Due to their nature, these devices have the following properties:
capacitive electric load: low power factor in range of 0.1 to 0.3
high ignition voltage 1–10 kV
huge amount of energy stored in electric field – requirement of energy recovery if DBD is not driven continuously
voltages and currents during discharge event have major influence on discharge behaviour (filamented, homogeneous).
Operation with continuous sine waves or square waves is mostly used in high power industrial installations. Pulsed operation of DBDs may lead to higher discharge efficiencies.
Driving circuits
Drivers for this type of electric load are power HF-generators that in many cases contain a transformer for high voltage generation. They resemble the control gear used to operate compact fluorescent lamps or cold cathode fluorescent lamps. The operation mode and the topologies of circuits to operate [DBD] lamps with continuous sine or square waves are similar to those standard drivers. In these cases, the energy that is stored in the DBD's capacitance does not have to be recovered to the intermediate supply after each ignition. Instead, it stays within the circuit (oscillates between the [DBD]'s capacitance and at least one inductive component of the circuit) and only the real power, that is consumed by the lamp, has to be provided by the power supply. Differently, drivers for pulsed operation suffer from rather low power factor and in many cases must fully recover the DBD's energy. Since pulsed operation of [DBD] lamps can lead to increased lamp efficiency, international research led to suiting circuit concepts. Basic topologies are resonant flyback and resonant half bridge. A flexible circuit, that combines the two topologies is given in two patent applications, and may be used to adaptively drive DBDs with varying capacitance.
An overview of different circuit concepts for the pulsed operation of DBD optical radiation sources is given in "Resonant Behaviour of Pulse Generators for the Efficient Drive of Optical Radiation Sources Based on Dielectric Barrier Discharges".
References
Electrical phenomena
Electricity
Electrostatics | Dielectric barrier discharge | Physics | 1,973 |
21,345,243 | https://en.wikipedia.org/wiki/Marquis%20de%20Sade | Donatien Alphonse François, Marquis de Sade ( ; ; 2 June 1740 – 2 December 1814) was a French writer, libertine, political activist and nobleman best known for his libertine novels and imprisonment for sex crimes, blasphemy and pornography. His works include novels, short stories, plays, dialogues, and political tracts. Some of these were published under his own name during his lifetime, but most appeared anonymously or posthumously.
Born into a noble family dating from the 13th century, Sade served as an officer in the Seven Years' War before a series of sex scandals led to his detention in various prisons and insane asylums for most of his adult life. During his first extended imprisonment from 1777 to 1790, he wrote a series of novels and other works, some of which his wife smuggled out of prison. On his release during the French Revolution, he pursued a literary career and became politically active, first as a constitutional monarchist then as a radical republican. During the Reign of Terror he was imprisoned for moderatism and narrowly escaped the guillotine. He was re-arrested in 1801 for his pornographic novels and was eventually incarcerated in the Charenton insane asylum where he died in 1814.
His major works include The 120 Days of Sodom, Justine, Juliette and Philosophy in the Bedroom, which combine graphic descriptions of sex acts, rape, torture, murder and child abuse with discourses on religion, politics, sexuality and philosophy. The word sadism derives from his fictional characters who take pleasure in inflicting pain on others.
There is debate over the extent to which Sade's behavior was criminal and sadistic. Peter Marshall states that Sade's "known behaviour (which includes only the beating of a housemaid and an orgy with several prostitutes) departs greatly from the clinical picture of active sadism." Andrea Dworkin, however, argues that the issue is whether one believes Sade or the women who accused him of sexual assault.
Interest in his work increased in the 20th century, with various authors considering him a precursor to Nietzsche, Freud, surrealism, totalitarianism, and anarchism. Many prominent intellectuals including Angela Carter, Simone de Beauvoir, and Roland Barthes published studies of his work and numerous biographies have appeared. Cultural depictions of his life and work include the play Marat/Sade by Peter Weiss and the film Salò, or the 120 Days of Sodom by Pier Paolo Pasolini. Dworkin and Roger Shattuck have criticized the rehabilitation of Sade's reputation, arguing that it promotes violent pornography likely to cause harm to women, the young and "unformed minds".
Life
Early life, education and marriage (17401763)
Sade was born on 2 June 1740, in the Hôtel de Condé, Paris, the only surviving child of Jean-Baptiste François Joseph, Count de Sade and Marie-Éléonore de Maillé de Carman. The Sade family was of the provincial nobility dating to the 13th century. Sade's mother was from a junior branch of the house of Bourbon-Condé and therefore Sade was related to the King of France by blood.
Sade's father was a captain of dragoons who was entrusted with diplomatic missions to the Russian Empire, Britain and the Elector of Cologne. His mother was lady-in-waiting to the Princess of Condé and, for his first four years, Sade lived in the Hôtel de Condé. The infant Sade was spoilt, haughty, and prone to violent rages. In 1744, he was sent to live with his grandmother in Avignon, probably because he had fought with his playmate, Louis Joseph, Prince of Condé, who was four years his senior.
The following year, Sade was placed in the care of his paternal uncle, the Abbé de Sade, a priest and libertine who lived in the château de Saumane in the Vaucluse region. The Abbé d'Amblet was appointed as Sade's tutor and the young marquis grew to respect him greatly. Meanwhile, the Count de Sade had lost favor with the king and had been recalled from his post in Germany. His career was now in ruins and his wife eventually left him to live in a Carmelite convent in Paris.
In the autumn of 1750, ten-year-old Sade was sent to the Jesuit college Louis-le-Grand in Paris, where he was taught Latin, Greek and rhetoric, and also participated in the school's theatrical productions. Sade's father was now heavily in debt and could not afford to enroll his son as a residential student, so Sade probably lived in private accommodation with Amblet. Residential students were discouraged from mixing with external students and this might have isolated Sade from his aristocratic peers. Biographers and historians are divided on whether or not Sade experienced caning (or other forms of corporal punishment), sexual abuse or sodomy while at school, and whether or not this influenced his sexual development.
Sade spent his summer holidays with Madame de Raimond, one of his father's former lovers, at the château de Longeville in the Champagne region. There, he met Madame de Saint-Germain, for whom he would hold a life-long affection. Both women became mother-figures for Sade.In 1754, Sade was sent to the Chevaux-légers military academy. After twenty months of training, on 14 December 1755, aged 15, Sade was commissioned as a sub-lieutenant in the King's Foot Guard. He soon went to battle at the onset of the Seven Years' War. After thirteen months as a sub-lieutenant, he was commissioned to the rank of cornet in the Brigade de Saint-André of the Comte de Provence's Carbine Regiment on 14 January 1757, and again promoted to the rank of captain in the Burgundian Cavalry on 21 April 1759. Despite this, Sade generally refused to ingratiate himself with his superiors, and "disdained making friends with his peers." He frequently infuriated his father with his gambling and womanizing.
By 1761, Sade had gained a reputation as a good soldier, but a gambler, spendthrift and libertine, all of which damaged any prospects of further promotion. In February 1763, the Treaty of Paris ended the Seven Years' War, and Sade was discharged. Back in Paris, he lived a life of pleasure, while his ill and seriously indebted father contemplated retiring to a monastery to avoid "having to welcome my son, with whom I am unhappy."
Sade's father was also negotiating with the Montreuil family for his son to marry their eldest daughter, Renée-Pélagie. Although the Montreuils were of bourgeois origin, and had only been ennobled in the 17th century, they were wealthy and had influential contacts, both at court and in legal circles. The count considered his son a financial burden with a poor character: "As for me, what makes up my mind is that I will be rid of the boy, who has not one good quality and all the bad ones."
Meanwhile, Sade had fallen in love with a nobleman's daughter named Laure de Lauris, but was abruptly rejected after two months of courtship. He was enraged, and threatened to blackmail Lauris by blaming his venereal disease on her to the next young man she courted. Sade, who proclaimed that he would "only marry for love", resisted the arranged marriage with the "plain and charmless" Renée-Pélagie, and did not attend court when, on 1 May 1763, the king and members of the royal family endorsed the marriage contract. Sade finally relented, and the two families signed the contract on 15 May. The wedding took place two days later.
Sade and Renée-Pélagie moved into rooms provided by her parents in the Hôtel de Montreuil in Paris. Sade was initially pleased with his new, strictly Catholic bride, writing to his uncle, "I don't know how to praise her enough." Two years later, however, he told the Abbé that she was "too cold and too devout." She gave birth to two sons and a daughter, and later became an accomplice to his alleged crimes with adolescents.
Scandals and imprisonment (17631790)
Testard affair and aftermath
Four months after his wedding, Sade was accused of blasphemy and incitement to sacrilege, which were capital offenses. He had rented a property in Paris which he used for sexual encounters. On 18 October 1763, Sade hired a prostitute named Jeanne Testard. Testard stated to the police that Sade had locked her in a bedroom before asking whether she believed in God. When she said that she did, Sade said there was no God and shouted obscenities concerning Jesus and the Virgin Mary. Sade then masturbated with a chalice and crucifix while shouting obscenities and blasphemies. He asked her to beat him with a cane and an iron scourge which had been heated by fire, but she refused. Sade then threatened her with pistols and a sword, telling her he would kill her if she did not trample on a crucifix and exclaim obscene blasphemies. She reluctantly complied. She spent the night with Sade, who read her irreligious poetry. He asked her for sodomy (another capital offense) but she refused. The following morning, Testard reported Sade to the authorities. On 29 October, following a police investigation, Sade was arrested on the personal orders of the king and jailed in Vincennes prison. Sade wrote several contrite letters to the authorities in which he expressed remorse and asked to see a priest. After Sade's father begged Louis XV for clemency, the king ordered Sade's release on 13 November.
On his release, Sade was exiled to the Montreuil estate at Échauffour, Normandy. In September 1764, the king revoked Sade's exile and the marquis returned to Paris where he took up a series of mistresses. In the summer of 1765 he took his then mistress, Mademoiselle Beauvoison, to his favourite castle at La Coste, Provence, where he passed her off as his wife, greatly offending Madame de Montreuil. The following year, he undertook renovations of La Coste, including building a theater for public performances.
In January 1767, Sade's father died. That summer, Sade went to La Coste where the local dignitaries and vassals formally swore homage to their new lord; a revival of a feudal custom which his father had avoided. On 27 August, his first son, Louis-Marie, was born.
Arcueil affair and aftermath
On 3 April 1768, Easter Sunday, Sade approached a 36-year-old widow named Rose Keller who was begging at the Place des Victoires in Paris. Keller stated that Sade offered her employment as a housekeeper. He took her in his carriage to his country residence in Arcueil, where he locked her in a room and threatened to kill her if she did not undress. He then tied her down on a bed and whipped her with a cane or a cat-o'-nine-tails. She stated he also cut her with a penknife and poured hot wax on her wounds. He brandished a knife and threatened to kill her if she did not stop screaming. He later gave her food and locked her in an upstairs room. She managed to escape out a window and sought help. She went to the authorities that evening and lodged a complaint. The local magistrate began an investigation the following day and news of the affair reached Madame de Montreuil on 7 April. She immediately sent representatives to Arcueil who paid Keller to withdraw her complaint. On 8 April, the king issued a lettre de cachet (a royal warrant for arrest and detention without trial) and Sade was imprisoned at the Château de Saumur and later the Pierre-Encize prison. On 15 April, the criminal chamber of the parlement de Paris took up the case and soon issued an arrest warrant for Sade. On 3 June, the king issued a pardon for the marquis, probably on the petition of the Montreuil family. The parlement interrogated Sade on 10 June and he stated that Keller was a prostitute who willingly supplied her services. He denied tying her down, cutting her with a knife or burning her with hot wax and stated that Keller did not complain about the flagellation at the time. The parlement accepted the king's pardon and ordered Sade to pay 100 livres in alms for prisoners. Sade was returned to Pierre-Encize prison under the lettre de cachet. On 16 November, the king ordered his release on the condition that he stay at La Coste under supervision.
The Arcueil affair was widely publicized, causing the Sade and Montreuil families great concern for their reputation. In June 1769, Renée-Pélagie gave birth to a second son, Donatien-Claude-Armand, and the Montreuils hoped this would help domesticate Sade. In July 1770, Sade returned to his Burgundy regiment where he encountered some hostility. In March 1771, however, he was granted a commission as Master of Cavalry which amounted to an official rehabilitation. Soon after, a daughter, Madeleine-Laure, was born. Sade, heavily in debt, was forced to sell his commission but this did not save him from a short spell in debtors' prison.
In November 1771, Renée-Pélagie's 19-year-old sister, Anne-Prospère, visited the Sades at La Coste. Sade developed "a fatal passion" for his sister-in-law and it is possible that they began a sexual relationship. The following year, he devoted himself to theatrical productions at La Coste and his Mazan property. He incurred large costs hiring professional actors and building elaborate sets.
Marseilles affair and aftermath
In June 1772, Sade and his manservant, Latour, traveled to Marseilles on the pretext of obtaining a loan. On 27 June, they engaged in an elaborately staged orgy with four prostitutes. The orgy included sexual intercourse, flagellation, and, according to some witnesses, both active and passive anal sex involving Sade, Latour and one of the prostitutes. Sade offered the prostitutes aniseed-flavored pastilles laced with Spanish fly. One of the prostitutes, Marianne Laverne, became ill after eating the pastilles. That evening, Sade had sex with another prostitute, Marguerite Coste, who became critically ill after eating the pastilles. Coste filed a complaint with the police and, after an investigation, a warrant was issued for the arrest of Sade on charges of sodomy and poisoning.
Sade went into hiding, and his wife paid Laverne and Coste to withdraw their complaints. The Marseilles court, however, continued the prosecution, sentencing Sade and Latour to death in absentia on 2 September. The sentence was confirmed by the Cours des Comptes de Provence in Aix on 11 September, and Sade and Latour were burnt in effigy the following day. Sade was now in Italy with Anne-Prospère, a liaison which turned Madame de Montreuil into his implacable enemy. He wrote to his mother-in-law from Italy, disclosing his location, and she used her influence to secure his arrest and imprisonment in the Fortress of Miolans, then part of the Kingdom of Sardinia. He escaped from the fortress on 30 April 1773 and returned to France.
Sade narrowly avoided arrest in January 1774 when he was warned of an imminent police raid on his home in La Coste which had been arranged by Madame de Montreuil. Following the death of Louis XV in May, Madame de Montreuil successfully petitioned for a new lettre de cachet for Sade's arrest in the name of King Louis XVI. Meanwhile, Renée-Pélagie requested an appeal of her husband's death sentence.
La Coste affair and aftermath
In September 1774, Sade and his wife hired seven new servants for their La Coste property, including a young male secretary and five young women, all around 15 years old. That winter (1774–75), Sade, with the tacit consent of his wife, engaged in a series of orgies with his servants. Although the details are unknown, it is probable that the orgies included sexual intercourse and flagellation. In January 1775, the families of the young women filed charges of kidnapping and seduction, and a criminal investigation commenced in Lyon. Sade's wife arranged for three of the girls to be sent to convents and one to the Abbé Sade until their wounds healed. One of the girls remained at La Coste and died of an illness a few months later. In June, Nanon Sablonnière, one of the servants involved in the La Coste orgies, quarreled with the Sades and left, finding refuge in a convent. Fearing that Nanon might provide damaging testimony, Madame de Montreuil falsely accused her of theft and successfully petitioned for a lettre de cachet. Nanon was arrested and imprisoned at Arles where she remained for over two years. In July, Sade, fearing arrest, left for Italy where he remained for a year.
Treillet affair and imprisonment
In June 1776, Sade was back at La Coste writing a travel book, Voyage d'Italie. That summer, he hired three young women as servants, including Catherine Treillet, age 22. In December, he recruited four more servants. Three of them left after one night, claiming that Sade had offered them money for sex. They informed Treillet's father and, in January, he went to La Coste to retrieve his daughter. He fired a pistol at Sade from point-blank range, but it misfired. After a second attempt to shoot him, Treillet's father left and filed a complaint of kidnapping and seduction against Sade.Madame de Montreuil then wrote to Sade telling him that his mother was critically ill in Paris. Sade and his wife arrived on 8 February 1777 only to find that his mother had been dead three weeks. On 13 February, he was arrested under the existing lettre de cachet and imprisoned in the Vincennes fortress.
With Sade now in custody, the parlement de Provence in Aix agreed to hear his appeal against his conviction for sodomy and poisoning. On 30 June 1778, the court overturned his conviction on poisoning and ordered a retrial on charges of debauchery and pederasty. Madame de Montreuil, wishing to avoid the disgrace of a criminal conviction in the family, sent a representative to Marseilles to bribe the prostitutes and other prospective witnesses. On 14 July 1778, after interrogating Sade and other witnesses, the appeals court overturned the sodomy conviction, finding him guilty of only "debauchery and immoderate libertinage." He was given a small fine and forbidden to enter Marseilles for three years. However, he was immediately re-arrested on a lettre de cachet and returned to police custody. Sade escaped custody while being transferred back to Paris and he returned to La Coste. On 26 August, he was re-arrested after a police raid on his château and was returned to Vincennes prison.
In prison, Sade engaged in extensive correspondence, mostly with his wife, and continued working on Voyage d'Italie and a number of plays. In the summer of 1782, he drafted Dialogue between a Priest and a Dying Man and began working on The 120 Days of Sodom. Vincennes prison was closed in February 1784 and Sade was transferred to the Bastille, where he produced a fair copy of The 120 Days of Sodom, which many critics consider his first major work. Sade began working on the novel Aline and Valcour and completed the novellas The Misfortunes of Virtue (1787) and Eugénie de Franval (1788). As revolutionary tension increased in Paris, Sade was outraged that his daily exercise was curtailed. On 2 July 1789, he improvised a megaphone and shouted to passers-by below that the warders were killing the prisoners. Sade was transferred to the Charenton insane asylum that evening. On 14 July, the Bastille was stormed by a revolutionary crowd and Sade's former cell was looted of his personal effects which remained there under seal. In March 1790, the National Constituent Assembly voted to abolish lettres de cachet and Sade was released from detention on 2 April.
Freedom and imprisonment (17901801)
On Sade's release, his wife sought a legal separation and the marriage was dissolved in September 1790. In August, he met Marie-Constance Quesnet, a 33-year-old actress, and they began a relationship which was to last until his death. Sade now called himself "Louis Sade, man of letters" and tried to launch a career as a writer. His novel Justine, or the Misfortunes of Virtue was published anonymously in June 1791. In October, his play Oxtiern opened at the Théâtre Molière in Paris, but closed after only two performances following audience uproar.
Sade was increasingly involved in politics, at first supporting a constitutional monarchy. However, as republican sentiment grew in 1792, Sade found himself in political difficulty due to his noble ancestry, public support of the monarchy and the emigration of his two sons. In March, his play Le Suborneur premiered at the Théâtre Italien but only lasted one night when Jacobin activists disrupted the performance. He began publicly espousing more radical republican views and became more prominent in his local revolutionary section, the Section des Piques. Following the fall of the monarchy in September 1792, he was appointed the section's commissioner on health and charitable institutions, and in October 1793 he was chosen to deliver the funeral oration for the revolutionary martyrs Marat and Le Peletier. In November, his section delegated him to deliver a petition against religion to the National Convention. His speech probably alienated Robespierre and other members of the convention and its powerful Committee of Public Safety who were attempting to suppress atheism and attacks on religion. In December 1793, Sade was arrested and charged with "moderatism", associating with counter-revolutionaries, anti-republicanism and "feigned patriotism". He was listed for execution on 27 July 1794 (9 Thermidor) but was saved either by bribery or bureaucratic error. Robespierre and his supporters fell from power that day, ending the Reign of Terror and paving the way for Sade's release from prison in October.
On his release, Sade concentrated on literature and his personal affairs. He published a series of anonymous novels: Philosophy in the Bedroom and Aline and Valcour (1795), and the first volumes of The New Justine and Juliette (1797–99). Sade had huge debts, little income from his properties, and the Vaucluse department had incorrectly placed him on its list of émigrés, leaving him vulnerable to arrest and confiscation of property. In October 1796, he was forced to sell La Coste, but his former wife obtained most of the proceeds. In 1798, Sade unsuccessfully petitioned Paul Barras, a leader of the Directory regime, to have his name removed from the list of émigrés. Sade's émigré status was finally revoked in December 1799, by which time he had fallen deeper into poverty and had registered as indigent.
In 1800, Sade published Crimes of Love, a collection of short stories published under his own name. The book received hostile reviews and a wave of articles appeared identifying Sade as the author of the scandalous Justine and Juliette.
Final imprisonment and death (18011814)
The Napoleonic Consulate was cracking down on public immorality and, in March 1801, Sade was arrested at his publisher's office and detained in the Sainte-Pélagie Prison. The stocks of The New Justine and Juliette were seized and the police minister Joseph Fouché ordered Sade's detention without trial as he believed the pornography laws did not provide for sufficient punishment and any trial would only increase Sade's notoriety. Following Sade's attempts to seduce young prisoners at Sainte-Pélagie, he was declared insane with "libertine dementia" and transferred to the Bicêtre Asylum.
After intervention by his family, he was transferred once more to the Charenton Asylum, where his ex-wife and children agreed to pay his room and board. Marie-Constance, pretending to be his illegitimate daughter, was allowed to live with him there. The director of Charenton, Abbé de Coulmier, attempted to run the institution on humane principles with an emphasis on "moral treatment" in accordance with the nature of the mental illness. He allowed Sade to write, produce and perform in plays, and also encouraged balls, concerts, dinners and other entertainments. In 1805, Coulmier had a theater built on the premises with seating for about 200. The performances, which included professional actors and inmates, became fashionable, attracting many among the elite of Napoleonic society.
Sade was also allowed to write. In April 1807, he completed Les journées de Florbelle, a ten-volume libertine novel. The novel was seized after a police search of Sade's and Quesnet's rooms. Sade later completed three conventional novels at Charenton.
Coulmier's novel approach to psychotherapy and the privileges granted to Sade attracted much opposition in official circles. In 1810, new police orders put Sade into solitary confinement and deprived him of pens and paper. Coulmier, however, gradually restored most of Sade's privileges.
In 1813, the government ordered Coulmier to suspend all theatrical performances, balls and concerts. By this time, Sade was in a sexual relationship with Madeleine Leclerc, the teenage daughter of an employee at Charenton. The relationship caused consternation for Quesnet and further allegations of immorality against Sade. In September 1814, the new director of Charenton asked the Bourbon restoration government to transfer Sade to another institution. Sade, however, was now seriously ill. He died on 2 December 1814 after an attack of "prostrating gangrenous fever."
Sade had left instructions in his will requesting that he be buried at his property at Malmaison without an autopsy or "pomp of any kind." However, Malmaison had been sold years earlier and Sade was buried with religious rites at Charenton. His skull was later removed from the grave for phrenological examination. His surviving son, Claude-Armand, had all his remaining unpublished manuscripts burnt, including Les Journées de Florbelle.
Posthumous evaluation
Marshall writes that Sade's "known behaviour (which includes only the beating of a housemaid and an orgy with several prostitutes) departs greatly from the clinical picture of active sadism." Phillips states "there is no reason to believe that any of this behaviour involved compulsion." Dworkin, however, argues that the issue is whether one believes Sade or his female accusers and that admirers of Sade "attempt to justify, trivialize, or deny (even though records confirming the facts exist) every assault Sade ever committed against women and girls." Gray states that Sade engaged in "psychic terrorism" and that "Sade's brand of sadism was often more mental than corporeal." According to Bongie, Sade perpetrated "crimes of physical violence committed during sexual assaults on hapless prostitutes. Such assaults, aggravated by death threats and the element of recidivism, could easily get an offender into similar difficulties today."
Political, religious and philosophical views
John Phillips argues that Sade's views cannot be easily determined due to the "difficulty of distinguishing a single authorial voice" from the multitude of characters in his fiction. Even in Sade's letters he was often playing a role which leads to "the ultimate impossibility of identifying the real Sade through his writing." The arguments his characters use to justify their more extreme behavior are often satire, parody and irony.
Geoffrey Gorer states that Sade was in opposition to contemporary thinkers for both his "complete and continual denial of the right to property" and for viewing the political conflict in late-18th-century France as being not between "the Crown, the bourgeoisie, the aristocracy or the clergy, or sectional interests of any of these against one another," but rather all of these "more or less united against the people." Thus, Gorer argued, "he can with some justice be called the first reasoned socialist."
Peter Marshall sees Sade as a precursor to anarchism in that he was libertarian in his desire to expand human freedom and contemplated a society without laws. Ultimately, however, Sade advocated a society with minimal laws.
Marshall writes that Sade was a proponent of free public brothels paid for by the state in order to reduce sex crimes and satisfy people's wishes to command and be obeyed. Dworkin, however, states that this proposal was for compulsory prostitution from childhood on, where women and girls could be raped by men. The proposal is from one of Sade's fictional characters, Le Chevalier, in the novel Philosophy in the Bedroom. Phillips argues that the views of Sade's characters cannot always be attributed to Sade. Gray suggests that Le Chevalier's speech should be read as subversive irony.
Maurice Lever, Laurence Louis Bongie and Francine du Plessix Gray present Sade as a political opportunist whose only consistent principles were libertinage, atheism, opposition to the death penalty and the defense of his own property and aristocratic privileges. Prior to the Revolution, Sade insisted on the observance of feudal customs. After the Revolution he supported the constitutional monarchy because that was the prevailing trend. Following the overthrow of the king, he publicly advocated republicanism only to protect himself from arrest as a supporter of the monarchy. Gray concludes, "relentlessly opportunistic in his public stances, the ci-devant marquis ... was an unswerving moderate horrified by political excess."
Albert Camus, writing in 1951, argued that Sade placed the sex drive at the centre of his thought. The sex drive is natural but a blind force that dominates man. The overthrow, in 1792, of a king ruling by divine right necessarily involved the abandonment of a system of law and morals sanctioned by God and sovereign. In its place, Sade advocated absolute moral license, allowing the passions to rule. If satisfaction of the passions involves crimes such as murder then this accords with the laws of nature, for destruction is necessary for creation. But if murder is licensed, all are at risk of being murdered. Therefore, absolute freedom must entail the struggle to dominate. For Camus, Sade advocated freedom of desire for the few which required the enslavement of the majority. Sade thus prefigured totalitarianism in the name of freedom.
Phillips states that Sade was greatly influenced by the materialism of La Mettrie and Holbach and by the determinism of Hume. According to this view, God does not exist, and man and the universe are nothing but matter which is infinitely broken down and reconfigured, never perishing. Free will is an illusion because everything has a cause which is determined by the materialist laws of nature. The character of libertines is therefore determined by nature and it is pointless to punish them for something for which they are not morally responsible. Sade's libertines sometimes substitute nature for God, regarding it as a destructive force whose laws must be respected, but sometimes see nature as a rival to their own power.
John Gray argues that Sade's philosophy is fundamentally religious as it replaces God with nature. However, it is also confused as it rails against nature while nevertheless advocating that humans follow nature's "destructive impulses".
Lester Crocker argues that Sade was the first to construct "a complete system of nihilism, with all its implications, ramifications and consequences." Sade believed morals are only human conventions and that individuals have a right to ignore laws and moral precepts that are contrary to the laws of nature and to pursue goals that are in accordance with nature. His libertines argue that human virtues such as charity, pity and respect for parents are against nature and should be shunned whereas murder and theft are natural passions and should be pursued. For Sade, the only human value is the egotistical pursuit of the passions. The primary passion is the sex drive which is inextricably linked to passions for destruction, violence and domination. For Sade's libertines, crime is not only necessary to establish and preserve their domination, it is also a pleasure in itself. They construct a hierarchy of the pleasures of crime according to which mere failure to help those in need gives the least pleasure and the torture and murder of children provide the greatest.
Crocker argues that Sade anticipated Freud in positing the primacy of the sex drive and linking it to destructive impulses. However, he sees Sade's nihilism as internally inconsistent in that he derives values from nature and posits one human value, contradicting his claim that there are no objective moral laws and leaving open the possibility that other human values can be posited and moral laws derived from nature.
Critical reception
Contemporary critics were generally hostile to Sade's works. When his play Oxtiern premiered in 1791, the critic for the Moniteur stated, "there is interest and energy in the play, but the role of Oxtiern is a revolting atrocity." The anonymous Justine and Juliette were seen as obscene works. A review of Justine in the Journal Général de France stated that although Sade displayed "a rich and brilliant" imagination, "It is difficult to not often close the book out of disgust and indignation." There were rumours that Danton and Robespierre used Justine as an aid to masturbation and to inflame their lust for blood. Rétif de la Bretonne published an Anti-Justine in 1798. By 1800, numerous authors were attributing Justine to Sade. One reviewer called Sade's Crimes of Love "a detestable book written by a man suspected of having written a yet more horrible one."
The mostly hostile reception continued throughout the 19th century. The French historian Jules Michelet called Sade the "professor emeritus of crime". Although writers such as Baudelaire, Flaubert, Stendhal, Byron and Poe expressed admiration for Sade's work, Swinburne found them unintentionally funny and Anatole France said, "their most dangerous ingredient is a fatal dose of boredom". In 1886, the sexologist Krafft-Ebing treated Sade's work as a compendium of sexual pathologies and gave the term sadism its clinical definition.
Interest in Sade increased in the 20th century. His biographer Laurence Louis Bongie writes, "Many different Sades have been invented over the years, and nearly always with passionate hostility towards opposing or even complementary definitions of the man." In 1909, Guillaume Apollinaire called him "the freest spirit that has yet existed". André Breton called him "a surrealist in Sadism" committed to "total liberation, both social and moral." Others see him as a precursor to Nietzsche and Freud. Writing soon after World War II, Raymond Queneau argued that Sade's moral universe prefigured National Socialism.
Simone de Beauvoir, in her essay "Must we burn Sade?" (published in 1951–52), argued that although Sade is a writer of the second rank and "unreadable", his value is making us rethink "the true nature of man's relationship to man."
After Sade's work became freely available in unexpurgated editions in France, the United States and the United Kingdom in the 1960s, critical interest in Sade accelerated. In 1971, Roland Barthes published an influential textual analysis, Sade, Fourier, Loyola, which largely resisted psychological, social and biographical interpretations of his work.
A number of prominent female commentators have praised Sade. Angela Carter, writing in 1978, argued that Sade put pornography in the service of women by claiming rights of free sexuality for them and depicting them in positions of power. Camille Paglia, writing in 1990, presented Sade as a rigorous philosopher of power relationships and sexuality who was undervalued in American academia because his emphasis on violence was difficult to accept. She argued that Sade could be best understood as a satirist, responding "point by point" to Rousseau's claims that society inhibits and corrupts mankind's innate goodness. Annie Le Brun has praised Sade for his emphasis on sexuality and the body, and has argued that Sade should be read as poetry and has been best appreciated by poets.
In contrast, Andrea Dworkin writes that in Sade's fiction women are naturally prostitutes and men have a natural right to rape women. The female libertines only enjoy power as the male libertines conceive it and only as long as they adopt violent male sexuality.
In 1990, Sade was published in the French Bibliothèque de la Pléiade series, which Roger Shattuck calls "an honor which corresponds to an artist being admitted into the Louvre". In 2014, French novelist Pierre Guyotat said, "Sade is, in a way, our Shakespeare. He has the same sense of tragedy, the same sweeping grandeur."
Andrea Dworkin, writing in 1981, condemned the veneration of Sade as a veneration of violence against women. Roger Shattuck, writing in 1996, argued that writers who try to rehabilitate Sade place too much emphasis on abstract notions of transgression, linguistic play and irony, and marginalize the sexual violence at the core of his life and work. He stated that Sade's works are likely to be harmful to the young and "unformed minds". French intellectual Michel Onfray states, "it is intellectually bizarre to make Sade a hero... Even according to his most hero-worshipping biographers, this man was a sexual delinquent".
Cultural influence
Crocker sees Sade's intellectual influence in the 19th century as reflected in writers such as Stendhal, Baudelaire and Dostoevsky, and thinkers such as Stirner and Nietzsche. However, he states that Sade's greatest impact was on the 20th century. In 1963 Crocker wrote, "Sade speaks with the loudest voice to our time...for it is our age that has had to live the truths he revealed...It is in the twentieth century that the failure of rationalism, revealed in history and psychology, has plunged our arts and often our acts into the absurd of nihilism."
Sade has also entered Western culture as a case study in sexual pathology. Sexual sadism disorder, a mental condition named after Sade, has been defined as experiencing sexual arousal in response to extreme pain, suffering or humiliation done non-consensually to others (as described by Sade in his novels). Other terms have been used to describe the condition, which may overlap with other sexual preferences that also involve inflicting pain. It is distinct from situations where consenting individuals use mild or simulated pain or humiliation for sexual excitement.
After World War II, Sade attracted increasing interest from intellectuals such as Georges Bataille, Michel Foucault, Camille Paglia and others as an early thinker on issues of sexuality, the body, transgression and nihilism.
A. D. Farr suggested that Sade's writing, particularly Philosophy in the Bedroom, influenced the subsequent medical and social acceptance of abortion in Western society. Dworkin, however, argues that Sade only extolled abortion as a form of murder which he sexualized. He more frequently advocated the murder of pregnant women. Phillips argues that the sexual liberation of the 1960s was the result of complex social factors and the availability of the contraceptive pill rather than the ideas of Sade.
Sade's writing has achieved commercial success since it became freely available in the 1960s. The American edition of Justine and Philosophy in the Bedroom alone sold 350,000 copies from 1965 to 1990 and about 4,000 copies a year from 1990 to 1996. Shattuck sees the cultural rehabilitation of Sade after World War II as an "eerie, post-Nietzschean death wish". Noting that Sade has been elevated into the French literary canon and that serial killers Ian Brady and Ted Bundy read and admired Sade, he concludes that Sade's "profusely illustrated moral nihilism has entered our cultural bloodstream at the highest intellectual and lowest criminal levels."
Phillips, in contrast, argues that Sade's enduring legacy is in replacing theological interpretations of the world with a materialist humanism thus contributing to "a modern intellectual climate in which all absolutisms are regarded with suspicion."
Cultural representations of Sade's life and work increased from the early 20th century, particularly among artists interested in the themes of freedom and human sexuality. Surrealists such as Breton and Éluard regarded Sade highly, and Man Ray, Salvador Dalí, Luis Buñuel and others represented Sade and Sadeian themes in art and film. Sade's influence on the arts continued after World War II, including the plays Marat/Sade (Peter Weiss, 1964) and Madame de Sade (Mishima, 1965), and the films Salò (Pasolini, 1975) and Quills (Kaufman, 2000).
Writing
Sade's writing includes novels, stories, plays, dialogues, travelogues, essays, letters, journals and political tracts. Many of his works have been lost or destroyed.
Libertine novels
Sade is best known for his libertine novels which combine graphic descriptions of sex and violence with long didactic passages in which his characters discuss the moral, religious, political and philosophical implications of their acts. The characters engage in a range of acts including blasphemy, sexual intercourse, incest, sodomy, flagellation, coprophilia, necrophilia and the rape, torture and murder of adults and children. The libertines argue that these acts accord with the laws of nature. Sade's major libertine novels are The 120 Days of Sodom (written 1785, first published 1899), Justine (two versions, published 1791 and 179799), Philosophy in the Bedroom (a novel in dialogue, published 1795) and Juliette (published 179799). The libertine novels include elements of pornography, Gothic fiction, moral and didactic tales, dark fairy tales in the manner of the brothers Grimm, and social, political and literary satire.
Other novels and tales
Sade's first substantial prose work was the Dialogue between a Priest and a Dying Man, written in 1782 while he was in prison. The work is not pornographic but outlines some of his main themes including the non-existence of God or an afterlife, nature as semi-divine, materialism and determinism, the permanent flux of living matter, a relativist and pragmatic morality, and a defence of libertinism. In prison he drafted an epistolary novel, Aline and Valcour (published 1795), and the novella The Misfortunes of Virtue, which he later expanded into the two versions of Justine. He also wrote about fifty tales, of which eleven were published under his own name, in the collection The Crimes of Love in 1800. The tales were not pornographic but contained themes of incest, libertinage and disaster.
In 181213, while confined at the Charenton insane asylum, he wrote three conventional historical novels: Adelaide of Brunswick, Princess of Saxony; The Secret History of Isabelle of Bavaria; and The Marquise de Gange.
Plays
Sade had a life-long interest in theater and during his first extended incarceration he wrote about twenty plays. Oxtiern and Le Suborneur were professionally staged on his release and he organized several others to be staged semi-professionally when he was confined at the Charenton asylum. According to critic John Phillips, "the overwritten melodramas he composed for the theatre have not attracted much critical interest to date, and are unlikely to ever do so."
Essays and political tracts
Sade's "Reflections on the Novel" was published as a preface to the collection The Crimes of Love in 1800. Sade reviews the development of the novel from classical times to the 18th century and provides rules for aspiring novelists. Sade advised writers not to depart from what is possible; not to interrupt the plot with repetitious or tangential incidents; that the author should leave any necessary moralizing to his characters; and that the author should not write primarily for money. Phillips and Edmund Wilson have praised Sade's knowledge of the history of European fiction while noting that in his libertine novels he violated most of his own principles for writing good fiction.
Sade's avowed political writings include his "Address to the King" (1791), his pamphlet "Idea on the method for the sanctioning of laws" (1792) and his eulogy for the revolutionaries Marat and Le Peletier (1793). In his 1791 address, Sade advocated a constitutional monarchy. In the 1792 pamphlet, Sade argued that all laws passed by the legislature should be ratified by local assemblies of active citizens. In his 1793 eulogy, he praised Marat and Le Peletier as "sublime martyrs of liberty". Phillips, Gray and others have speculated on whether these writings express Sade's real political views or were parodies or exercises in political expediency to forestall his possible persecution as a former aristocrat.
Letters and journals
Over 200 of Sade's letters, mostly written to his wife from prison, have been published since his death. Sade's journals for 18078 and JulyDecember 1814 also survive. Bongie has called his prison letters "his lasting literary achievement." Richard Seaver states that the prison letters "reveal more about this most enigmatic of men than any of his other work." Phillips warns that in his letters and journals Sade was often playing a role and creating a fictionalized version of himself.
Legacy
For many years, Sade's descendants regarded his life and work as a scandal to be suppressed. This did not change until the mid-20th century, when the Comte Xavier de Sade reclaimed the marquis title, long fallen into disuse, and took an interest in his ancestor's writings. He subsequently discovered a store of Sade's papers in the family château at Condé-en-Brie, and worked with scholars for decades to enable their publication. His youngest son, the Marquis Thibault de Sade, has continued the collaboration. The family have also claimed a trademark on the name. The family sold the Château de Condé in 1983. As well as the manuscripts they retain, others are held in universities and libraries. Many, however, were lost in the 18th and 19th centuries. A substantial number were destroyed after Sade's death at the instigation of his son, Donatien-Claude-Armand.
Sade's favorite castle at Lacoste was bought and partially restored by Pierre Cardin. Since the restoration it has been used as a site for theater and music festivals.
The Sade documents found in 1948 became the basis for Gilbert Lely's important biography of Sade published in two volumes in 1952 and 1957. Volumes of Sade's letters, journals and other personal documents have been published progressively from 1949. In 1966, the French publisher Jean-Jacques Pauvert published a 30-volume edition of his complete works. From 1990, Sade's works were published in the French Pléiade editions.
See also
BDSM
Leopold von Sacher-Masoch
Sexual fetishism
Jesús Franco directed films based on the Marquis de Sade's works
Jeanne Hachette
Works cited
References
Notes
Further reading
Marquis de Sade: his life and works. (1899) by Iwan Bloch
Sade Mon Prochain. (1947) by Pierre Klossowski
Lautréamont and Sade. (1949) by Maurice Blanchot
The Marquis de Sade, a biography. (1961) by Gilbert Lely
Philosopher of Evil: The Life and Works of the Marquis de Sade. (1962) by Walter Drummond
Sade, Fourier, Loyola. (1971) by Roland Barthes
De Sade: A Critical Biography. (1978) by Ronald Hayman
The Marquis de Sade: the man, his works, and his critics: an annotated bibliography. (1986) by Colette Verger Michael
Sade, his ethics and rhetoric. (1989) collection of essays, edited by Colette Verger Michael
The philosophy of the Marquis de Sade. (1995) by Timo Airaksinen
Sade contre l'Être suprême. (1996) by Philippe Sollers
A Fall from Grace (1998) by Chris Barron
An Erotic Beyond: Sade. (1998) by Octavio Paz
Sade: A Sudden Abyss. (2001) by Annie Le Brun
Sade: from materialism to pornography. (2002) by Caroline Warman
Marquis de Sade: the genius of passion. (2003) by Ronald Hayman
Pour Sade. (2006) by Norbert Sclippa
Outsider Biographies; Savage, de Sade, Wainewright, Ned Kelly, Billy the Kid, Rimbaud and Genet: Base Crime and High Art in Biography and Bio-Fiction, 1744–2000 (2014) by Ian H. Magedera
Sade's Sensibilities. (2014) edited by Kate Parker and Norbert Sclippa (A collection of essays reflecting on Sade's influence on his bicentennial anniversary.)
External links
Œuvres du Marquis de Sade
Carnet du Marquis de Sade Site run by a descendant of the Marquis de Sade. Weekly publication of the article(s) around the current de Sade.
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18,909,256 | https://en.wikipedia.org/wiki/Blue%20screen%20of%20death | The blue screen of death (BSoD) or blue screen error, blue screen, fatal error, bugcheck, and officially known as a stop erroris a critical error screen displayed by the Microsoft Windows operating systems to indicate a system crash, in which the operating system reaches a critical condition where it can no longer operate safely.
Possible issues that may cause a BSoD include hardware failures, an issue with or without a device driver, viruses, malware, and other factors such as intentional user action.
History
Blue screen errors have existed since the first beta release of Windows 1.0; if Windows found a newer DOS version than it expected, the boot screen would have the text "Incorrect DOS version" alongside other messages detailing what check failed to pass appended into it before starting normally. This still works in the final release (version 1.01); however the screen mostly prints out random characters instead due to the remaining text messages being removed during development. This is not a crash screen, however; upon crashing, Windows 1.0 would simply lock up or exit to DOS. This behavior is also present in Windows 2.0 and Windows 2.1.
Windows 3.0 uses a text-mode screen for displaying important system messages, usually from digital device drivers in 386 Enhanced Mode or other situations where a program could not run. Windows 3.1 changed the color of this screen from black to blue. It also displays a blue screen when the user presses the Ctrl+Alt+Delete key combination to bring up a rudimentary task manager, reserved for quitting any unresponsive programs if they are available. As with prior versions before it, Windows 3.x exits to DOS if an error condition is severe enough.
The first BSoD appeared in Windows NT 3.1 (the first version of the Windows NT family, released in 1993). The error screens initially started with *** STOP: in its earlier iterations, hence it became known as a "stop error." This format later appeared on all Windows operating systems released afterwards, with various differences in later versions.
BSoDs can be caused by poorly written device drivers or malfunctioning hardware, such as faulty memory, power supply problems, overheating of components, or hardware running beyond its specification limits. In the Windows 9x operating systems, incompatible DLLs or bugs in the operating system kernel could also cause BSoDs. Because of the instability and lack of memory protection in Windows 9x OSes, BSoDs were much more common.
BSoDs are not included in the Windows Embedded Compact (formerly known as Windows CE) line of embedded operating systems.
Attribution
On September 4, 2014, several online journals such as Business Insider, DailyTech, Engadget, Gizmodo, Lifehacker, Neowin, Softpedia, TechSpot, Boy Genius Report (BGR), The Register, and The Verge, as well as print and non-English sources like PC Authority and Austrian tech site FutureZone all attributed the creation of the Blue Screen of Death to Steve Ballmer, Microsoft's former CEO. Their articles cited a blog post by Microsoft employee Raymond Chen entitled "Who wrote the text for the Ctrl+Alt+Del dialog in Windows 3.1?", specifically focusing on the creation of the first rudimentary task manager in Windows 3.x. This aforementioned task manager shared some visual similarities with a BSOD, with Ballmer writing the messages that appeared on the screen.
Chen had to address this widespread misinformation in a blog post on September 9, 2014. In his post, he was scathing on his evaluation of major tech news sites that had picked up on the incorrect story and performed poor or non-existent research that demonstrated complete ignorance of his original account. He indicated that, in addition to the faulty base story, over half a dozen significant sites had included other embellished or invented details in their stories, including incorrectly naming Chen as a Microsoft executive, treating Chen as an "official company spokesperson", and using unrelated images from Windows NT or Windows 95 as illustrations. In addition, he also pointed out a very special mention for the worst single distortion out of any misinformations, which belonged to BGR (Boy Genius Report), who "fabricated a scenario and posited it as real" in a rhetorical question to readers. He also found that several sources had conflated the creation of the BSoD with the fact that they occur, thus inverting cause and effect by implying that the invention of BSoDs caused fatal errors to occur instead of their actual, helpful function of giving the user information about a fatal error after the system has already become unrecoverable (such incorrect sources transitively blamed Ballmer for the existence of all fatal crashes in Windows). Chen would later follow this up with a blog post the day after his initial complaint, claiming responsibility for revising the BSoD in Windows 95. His post said in detail that he was the one who "sort of" created the BSoD in its first modern incarnation in Windows 95.
On the other hand, the Blue Screen of Death (also known as a Stop error) in the Windows NT family was not based on the rudimentary task manager screen of Windows 3.x, but was actually designed by Microsoft developer John Vert, according to former Microsoft employee Dave Plummer. Additionally, Vert has also stated the reason why Stop error screens were assigned the color blue was because the universal color palette of the video hardware at that time was very rudimentary and he personally used a MIPS OS box and SlickEdit for programming so that the firmware and editor both displayed white text on a blue background, making it for a more consistent programming experience.
Formats
BSoDs originally showed silver text on a royal blue background with information about current memory values and register values. Starting with Windows Server 2012 (released in September 2012), Windows adopted a cerulean background. Earlier versions of Windows 11 used a black background before later switching to a dark blue background starting with build 22000.348. Preview builds of Windows 10, Windows 11, and Windows Server (available from the Windows Insider program) feature a dark green background instead of a blue one. Windows 3.1, 95, and 98 supports customizing the color of the screen whereas the color is hard-coded in the Windows NT family.
Windows 95, 98, and Me render their BSoDs in the 80×25 text mode with a 720×400 screen resolution. BSoDs in the Windows NT family initially used the 80×50 text mode with a 720×400 screen resolution, but changed to use the 640×480 screen resolution starting with Windows 2000 up to 7. Windows 2000 used its built-in kernel mode font, Windows XP, Vista, and 7 use the Lucida Console font, and Windows 8 and Windows Server 2012 used the Segoe UI font. BSoDs on Windows 8 and Windows Server 2012 are rendered in higher resolutions than previous versions of Windows, where it uses the highest screen resolution available on UEFI machines. On legacy BIOS machines, they use the 1024×768 resolution by default, but they can also be configured to use the highest resolution available (via the 'highestmode' parameter in Boot Configuration Data). Windows 10 builds 14316 and up uses the same format as Windows 8, but has a QR code which leads to a Microsoft Support web page that tries to help users troubleshoot the issue step-by-step. This format was retained in Windows 11.
Windows NT
In the Windows NT family of operating systems, the blue screen of death (referred to as "bug check" in the Windows software development kit and driver development kit documentation) occurs when the kernel or a driver running in kernel mode encounters an error from which it cannot recover. This is usually caused by an illegal operation being performed. The only safe action the operating system can take in this situation is to restart the computer. Because of this, data loss may occur since the restart is unplanned, and the user is not given an opportunity to save their work.
The text on the error screen contains the code of the error and its symbolic name (e.g. "0x0000001E, KMODE_EXCEPTION_NOT_HANDLED") along with four error-dependent values in parentheses that are there to help software engineers fix the problem that occurred. Depending on the error code, it may display the address where the problem occurred, along with the driver which is loaded at that address. Under Windows NT, the second and third sections of the screen may contain information on all loaded drivers and a stack dump, respectively. The driver information is in three columns; the first lists the base address of the driver, the second lists the driver's creation date (as a Unix timestamp), and the third lists the name of the driver. By default, Windows will create a memory dump file when a stop error occurs. Depending on the OS version, there may be several formats this can be saved in, ranging from a 64kB "minidump" (introduced in Windows 2000) to a "complete dump" which is effectively a copy of the entire contents of physical memory (RAM). The resulting memory dump file may be debugged later, using a kernel debugger. For Windows, WinDBG or KD debuggers from Debugging Tools for Windows are used. A debugger is necessary to obtain a stack trace, and may be required to ascertain the true cause of the problem; as the information on-screen is limited and thus possibly misleading, it may hide the true source of the error. By default, Windows XP is configured to save only a 64kB minidump when it encounters a stop error, and to then automatically reboot the computer. Because this process happens very quickly, the blue screen may be seen only for an instant or not at all. Users have sometimes noted this as a random reboot rather than a traditional stop error, and are only aware of an issue after Windows reboots and displays a notification that it has recovered from a serious error. This happens only when the computer has a function called "Auto Restart" enabled, which can be disabled in the Control Panel which in turn shows the stop error.
Microsoft Windows can also be configured to send live debugging information to a kernel debugger running on a separate computer. If a stop error is encountered while a live kernel debugger is attached to the system, Windows will halt execution and cause the debugger to break in, rather than displaying the BSoD. The debugger can then be used to examine the contents of memory and determine the source of the problem.
A BSoD can also be caused by a critical boot loader error, where the operating system is unable to access the boot partition due to incorrect storage drivers, a damaged file system or similar problems. The error code in this situation is STOP: 0x0000007B (INACCESSIBLE_BOOT_DEVICE). In such cases, there is no memory dump saved. Since the system is unable to boot from the hard drive in this situation, correction of the problem often requires using the repair tools found on the Windows installation disc.
Details
Before Windows Server 2012, each BSoD displayed an error name in uppercase (e.g. APC_INDEX_MISMATCH), a hexadecimal error number (e.g. 0x00000001) and four parameters. The last two are shown together in the following format:
Depending on the error number and its nature, all, some, or even none of the parameters contain data pertaining to what went wrong, and/or where it happened. In addition, the error screens showed four paragraphs of general explanation and advice and may have included other technical data such the file name of the culprit and memory addresses.
With the release of Windows Server 2012, the BSoD was changed, removing all of the above in favor of the error name and a concise description. Windows 8 also added a sad emoticon, which is absent on Japanese versions or Server counterparts. The hexadecimal error code and parameters can still be found in the Windows Event Log or in memory dumps, however the "Fatal System Error" BSoDs (which have also changed since Windows Server 2012) had the hexadecimal error code "0xc000021a" in place of the error name. Since Windows 10 build 14316, the screen features a QR code for quick troubleshooting. All references to "PC" are changed to the word "device" starting from Windows 10 v2004 onwards.
Windows 9x
The Windows 9x line of operating systems used the Blue Screen of Death as the main way for virtual device drivers to report errors to the user. This version of the BSoD, internally referred to as "_VWIN32_FaultPopup", gives the user the option either to restart the computer or to continue using Windows, allowing the user to save their work before any data could be lost. Depending on the type of situation it may have occurred, however, the options to either continue or restart may or may not work at all. This is in contrast to the Windows NT version of BSoDs, which prevented the user from using the computer until it has been powered off or restarted (usually automatic for the latter).
The most common BSoD is displayed on an 80×25 text-mode screen, which is the operating system's way of reporting an interrupt caused by a processor exception; it is a more serious form of the general protection fault dialog boxes. The memory address of the error is given and the error type is a hexadecimal number from 00 to 11 (0 to 17 decimal). The error codes are as follows:
00: Division fault
01: Startup Error
02: Non-Maskable Interrupt
03: Shutdown Error
04: Overflow Trap
05: Bounds Check Fault
06: Invalid Opcode Fault
07: "Coprocessor Not Available" Fault
08: Double Fault
09: Coprocessor Segment Overrun
0A: Invalid Task State Segment Fault
0B: Not Present Fault
0C: Stack Fault
0D: General Protection Fault
0E: Page Fault
0F: Error Message Limit Exceed
10: Coprocessor Error Fault
11: Alignment Check Fault
Reasons for BSoDs include:
Problems that occur with incompatible versions of DLLs: Windows loads these DLLs into memory when they are needed by application programs; if versions are changed, the next time an application loads the DLL it may be different from what the application expects. These incompatibilities increase over time as more new software is installed. It is one of the many reasons why some people said that a clean install of Windows is more stable than an "old" one (or an in-place upgrade).
Faulty or poorly written device drivers.
Hardware incompatibilities.
Damaged hardware may also cause a BSoD.
In Windows 95 and 98, a BSoD occurs when the system attempts to access the file "c:\con\con", "c:\aux\aux", or "c:\prn\prn" on the hard drive. This could be inserted on a website to crash visitors' machines as a prank. In reality, however, they are reserved device names for DOS systems; attempting to access them from Windows causes a crash, which in turn brings up said BSoD. Creating the aforementioned directories within Windows will also not work and may cause the same BSOD to occur. On March 16, 2000, Microsoft released a security update to resolve this issue.
One famous instance of a Windows 9x BSoD occurred during a presentation of a Windows 98 beta given by Bill Gates at COMDEX on April 20, 1998: The demo PC crashed with a BSoD when his assistant, Chris Capossela, connected a scanner to the PC to demonstrate Windows 98's support for Plug and Play devices. This event brought thunderous applause from the crowd and Gates replied (after a nervous pause): "That must be why we're not shipping Windows 98 yet."
systemd
systemd, a software suite providing system components for Linux operating systems, implements a blue screen of death similar to that of Microsoft Windows using a systemd unit called systemd-bsod since August 2023, which was fully added on December 6, 2023 starting with version 255 of systemd. While it does not fully replace the kernel panic featured within Linux (see below), it is used in the event of a boot failure.
Similar screens
Stop errors are comparable to kernel panics in macOS, Linux, and other Unix-like systems, and to bugchecks in OpenVMS. ReactOS, an open-source operating system designed to achieve binary compatibility with Windows, implements a version of the Blue Screen of Death similar to that used in Windows NT operating systems.
Windows 3.1 displays a black screen of death instead of a blue one. Some versions of macOS (notably OS X Lion) display a black screen of death instead of a kernel panic, usually pointed to a graphics card or sleep/wake issue, it may also display a black screen when the operating system fails to boot properly. The Xbox series of consoles (which includes the original Xbox, Xbox 360, Xbox One and the Xbox Series X/S) also display a black screen upon hardware or software error.
Beta versions of Windows 98 display a red error screen raised by the Advanced Configuration and Power Interface (ACPI) when the host computer's BIOS encounters a problem. The bootloader of the first beta version of Windows Vista originally displayed a red screen background in the event of a boot failure.
As mentioned earlier, the insider builds of Windows 10 and later, as well as Windows Server 2016 and later, display a green screen. Windows 10 and later (and Windows Server 2016 and later) also display an orange screen when a driver incompatibility is present.
See also
Screens of death
Guru Meditation
Kernel panic
Purple Screen of Death
Sad Mac
Black screen of death
Red Ring of Death
Hang (computing)
Machine-check exception (MCE)
Windows Hardware Error Architecture (WHEA)
References
External links
Bug Check Code Reference
SysInternals BlueScreen Screen Saver v3.2
Blue Screen of Death. on MalWiki.
Computer errors
Windows administration
Screens of death | Blue screen of death | Technology | 3,776 |
29,248 | https://en.wikipedia.org/wiki/Space%20colonization | Space colonization (or extraterrestrial colonization) is the colonization of outer space and astronomical bodies. As such it is a process of occupation or control for exploitation, such as extraterrestrial mining, and possibly extraterrestrial settlement.
Making territorial claims in space is prohibited by international space law, defining space as a common heritage. International space law has had the goal to prevent colonial claims and militarization of space, and has advocated the installation of international regimes to regulate access to and sharing of space, particularly for specific locations such as the limited space of geostationary orbit or the Moon. To date, no permanent space settlement other than temporary space habitats have been established, nor has any extraterrestrial territory or land been internationally claimed. Currently there are also no plans for building a space colony by any government. However, many proposals, speculations, and designs, particularly for extraterrestrial settlements have been made through the years, and a considerable number of space colonization advocates and groups are active. Currently, the dominant private launch provider SpaceX, has been the most prominent organization planning space colonization on Mars, though having not reached a development stage beyond launch and landing systems.
As a form of colonialism, space colonization is a multi-dimensional exploitation of people and environments. In this sense space colonization raises numerous socio-political questions. Many arguments for and against space settlement have been made. The two most common reasons in favor of colonization are the survival of humans and life independent of Earth, making humans a multiplanetary species, in the event of a planetary-scale disaster (natural or human-made), and the commercial use of space particularly for enabling a more sustainable expansion of human society through the availability of additional resources in space, reducing environmental damage on and exploitation of Earth, for the sake of de-colonizing Earth. The most common objections include concerns that the commodification of the cosmos may be likely to continue pre-existing detrimental processes such as environmental degradation, economic inequality and wars, enhancing the interests of the already powerful, particularly major economic and military institutions instead of halting the space colonization process and invest in solving existing major environmental and social issues.
The mere construction of an extraterrestrial settlement, with the needed infrastructure, presents daunting technological, economic and social challenges. Space settlements are generally conceived as providing for nearly all (or all) the needs of larger numbers of humans. The environment in space is very hostile to human life and not readily accessible, particularly for maintenance and supply. It would involve much advancement of currently primitive technologies, such as controlled ecological life-support systems. With the high cost of orbital spaceflight (around $1400 per kg, or $640 per pound, to low Earth orbit by SpaceX Falcon Heavy), a space settlement would currently be massively expensive, but ongoing progress in reusable launch systems aim to change that (possibly reaching $20 per kg to orbit), and in creating automated manufacturing and construction techniques.
Definition
Space colonization has been in a broad sense referred to as space settlement, space humanization or space habitation. Space colonization in a narrow sense refers to space settlements, as envisioned by Gerard K. O'Neill. It is characterized by elements such as: settlement and exploitation, as well as territorial claim.
The concept in its broad sense has been applied to any permanent human presence, even robotic, particularly along with the term "settlement", being imprecisely applied to any human space habitat, from research stations to self-sustaining communities in space.
The words colony and colonization are terms rooted in colonial history on Earth, making them human geographic as well as particularly political terms. This broad use for any permanent human activity and development in space has been criticized, particularly as colonialist and undifferentiated (see below Objections).
In this sense, a colony is a settlement that claims territory and exploits it for the settlers or their metropole. Therefore a human outpost, while possibly a space habitat or even a space settlement, does not automatically constitute a space colony. Though entrepôts like trade factories (trading posts) did often grow into colonies.
Therefore any basing can be part of colonization, while colonization can be understood as a process that is open to more claims, beyond basing. The International Space Station, the longest-occupied extraterrestrial habitat thus far, does not claim territory and thus is not usually considered a colony. That said satellites have been identified by Moriba Jah as colonizing the orbits they take, by occupying the orbits in a form of ownership instead of stewardship.
History
When the first space flight programs commenced, they partly used – and have continued to use – colonial spaces on Earth, such as places of indigenous peoples at the RAAF Woomera Range Complex, Guiana Space Centre or contemporarily for astronomy at the Mauna Kea telescope. When orbital spaceflight was achieved in the 1950s colonialism was still a strong international project, e.g. easing the United States to advance its space program and space in general as part of a "New Frontier".
At the same time of the beginning of the Space Age, decolonization gained again in force, producing many newly independent countries. These newly independent countries confronted spacefaring countries, demanding an anti-colonial stance and regulation of space activity when space law was raised and negotiated internationally. Fears of confrontations because of land grabs and an arms race in space between the few countries with spaceflight capabilities grew and were ultimately shared by the spacefaring countries themselves. This produced the wording of the agreed on international space law, starting with the Outer Space Treaty of 1967, calling space a "province of all mankind" and securing provisions for international regulation and sharing of outer space.
The advent of geostationary satellites raised the case of limited space in outer space. A group of equatorial countries, all of which were countries that were once colonies of colonial empires, but without spaceflight capabilities, signed in 1976 the Bogota Declaration. These countries declared that geostationary orbit is a limited natural resource and belongs to the equatorial countries directly below, seeing it not as part of outer space, humanity's common. Through this, the declaration challenged the dominance of geostationary orbit by spacefaring countries through identifying their dominance as imperialistic. Furthermore this dominance in space has foreshadowed threats to the Outer Space Treaty guaranteed accessibility to space, as in the case of space debris which is ever increasing because of a lack of access regulation.
In 1977, the first sustained space habitat, the Salyut 6 station, was put into Earth's orbit. Eventually the first space stations were succeeded by the ISS, today's largest human outpost in space and closest to a space settlement. Built and operated under a multilateral regime, it has become a blueprint for future stations, such as around and possibly on the Moon. An international regime for lunar activity was demanded by the international Moon Treaty, but is currently developed multilaterally as with the Artemis Accords. The only habitation on a different celestial body so far have been the temporary habitats of the crewed lunar landers. Similar to the Artemis program, China is leading an effort to develop a lunar base called the International Lunar Research Station beginning in the 2030s.
Conceptual
In the first half of the 17th century John Wilkins suggested in A Discourse Concerning a New Planet that future adventurers like Francis Drake and Christopher Columbus might reach the Moon and allow people to live there. The first known work on space colonization was the 1869 novella The Brick Moon by Edward Everett Hale, about an inhabited artificial satellite. In 1897, Kurd Lasswitz also wrote about space colonies. The Russian rocket science pioneer Konstantin Tsiolkovsky foresaw elements of the space community in his book Beyond Planet Earth written about 1900. Tsiolkovsky imagined his space travelers building greenhouses and raising crops in space. Tsiolkovsky believed that going into space would help perfect human beings, leading to immortality and peace. One of the first to speak about space colonization was Cecil Rhodes who in 1902 spoke about "these stars that you see overhead at night, these vast worlds which we can never reach", adding "I would annex the planets if I could; I often think of that. It makes me sad to see them so clear and yet so far". In the 1920s John Desmond Bernal, Hermann Oberth, Guido von Pirquet and Herman Noordung further developed the idea. Wernher von Braun contributed his ideas in a 1952 Colliers magazine article. In the 1950s and 1960s, Dandridge M. Cole published his ideas. Another seminal book on the subject was the book The High Frontier: Human Colonies in Space by Gerard K. O'Neill in 1977 which was followed the same year by Colonies in Space by T. A. Heppenheimer. Marianne J. Dyson wrote Home on the Moon; Living on a Space Frontier in 2003; Peter Eckart wrote Lunar Base Handbook in 2006 and then Harrison Schmitt's Return to the Moon written in 2007.
Law, governance, and sovereignty
Space activity is legally based on the Outer Space Treaty, the main international treaty. But space law has become a larger legal field, which includes other international agreements such as the significantly less ratified Moon Treaty and diverse national laws.
The Outer Space Treaty established the basic ramifications for space activity in article one: "The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind."
And continued in article two by stating: "Outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means."
The development of international space law has revolved much around outer space being defined as common heritage of mankind. The Magna Carta of Space presented by William A. Hyman in 1966 framed outer space explicitly not as terra nullius but as res communis, which subsequently influenced the work of the United Nations Committee on the Peaceful Uses of Outer Space.
Reasons
Survival of human civilization
A primary argument calling for space colonization is the long-term survival of human civilization and terrestrial life. By developing alternative locations off Earth, the planet's species, including humans, could live on in the event of natural or human-made disasters on Earth.
On two occasions, theoretical physicist and cosmologist Stephen Hawking argued for space colonization as a means of saving humanity. In 2001, Hawking predicted that the human race would become extinct within the next thousand years unless colonies could be established in space. In 2010, he stated that humanity faces two options: either we colonize space within the next two hundred years, or we will face the long-term prospect of extinction.
In 2005, then NASA Administrator Michael Griffin identified space colonization as the ultimate goal of current spaceflight programs, saying:
Louis J. Halle Jr., formerly of the United States Department of State, wrote in Foreign Affairs (Summer 1980) that the colonization of space will protect humanity in the event of global nuclear warfare. The physicist Paul Davies also supports the view that if a planetary catastrophe threatens the survival of the human species on Earth, a self-sufficient colony could "reverse-colonize" Earth and restore human civilization. The author and journalist William E. Burrows and the biochemist Robert Shapiro proposed a private project, the Alliance to Rescue Civilization, with the goal of establishing an off-Earth "backup" of human civilization.
Based on his Copernican principle, J. Richard Gott has estimated that the human race could survive for another 7.8 million years, but it is not likely to ever colonize other planets. However, he expressed a hope to be proven wrong, because "colonizing other worlds is our best chance to hedge our bets and improve the survival prospects of our species".
In a theoretical study from 2019, a group of researchers have pondered the long-term trajectory of human civilization. It is argued that due to Earth's finitude as well as the limited duration of the Solar System, mankind's survival into the far future will very likely require extensive space colonization. This 'astronomical trajectory' of mankind, as it is termed, could come about in four steps: First step, space colonies could be established at various habitable locations — be it in outer space or on celestial bodies away from Earth – and allowed to remain temporarily dependent on support from Earth. In the second step, these colonies could gradually become self-sufficient, enabling them to survive if or when the mother civilization on Earth fails or dies. Third step, the colonies could develop and expand their habitation by themselves on their space stations or celestial bodies, for example via terraforming. In the fourth step, the colonies could self-replicate and establish new colonies further into space, a process that could then repeat itself and continue at an exponential rate throughout the cosmos. However, this astronomical trajectory may not be a lasting one, as it will most likely be interrupted and eventually decline due to resource depletion or straining competition between various human factions, bringing about some 'star wars' scenario.
Vast resources in space
Resources in space, both in materials and energy, are enormous. The Solar System has enough material and energy to support anywhere from several thousand to over a billion times that of the current Earth-based human population, mostly from the Sun itself.
Asteroid mining will likely be a key player in space colonization. Water and materials to make structures and shielding can be easily found in asteroids. Instead of resupplying on Earth, mining and fuel stations need to be established on asteroids to facilitate better space travel. Optical mining is the term NASA uses to describe extracting materials from asteroids. NASA believes by using propellant derived from asteroids for exploration to the moon, Mars, and beyond will save $100 billion. If funding and technology come sooner than estimated, asteroid mining might be possible within a decade.
Although some items of the infrastructure requirements above can already be easily produced on Earth and would therefore not be very valuable as trade items (oxygen, water, base metal ores, silicates, etc.), other high-value items are more abundant, more easily produced, of higher quality, or can only be produced in space. These could provide (over the long-term) a high return on the initial investment in space infrastructure.
Some of these high-value trade goods include precious metals, gemstones, power, solar cells, ball bearings, semi-conductors, and pharmaceuticals.
The mining and extraction of metals from a small asteroid the size of 3554 Amun or (6178) 1986 DA, both small near-Earth asteroids, may yield 30 times as much metal as humans have mined throughout history. A metal asteroid this size would be worth approximately US$20 trillion at 2001 market prices
The main impediments to commercial exploitation of these resources are the very high cost of initial investment, the very long period required for the expected return on those investments (The Eros Project plans a 50-year development), and the fact that the venture has never been carried out before—the high-risk nature of the investment.
Expansion with fewer negative consequences
Expansion of humans and technological progress has usually resulted in some form of environmental devastation, and destruction of ecosystems and their accompanying wildlife. In the past, expansion has often come at the expense of displacing many indigenous peoples, the resulting treatment of these peoples ranging anywhere from encroachment to genocide. Because space has no known life, this need not be a consequence, as some space settlement advocates have pointed out. However, on some bodies of the Solar System, there is the potential for extant native lifeforms and so the negative consequences of space colonization cannot be dismissed.
Counterarguments state that changing only the location but not the logic of exploitation will not create a more sustainable future.
Alleviating overpopulation and resource demand
An argument for space colonization is to mitigate proposed impacts of overpopulation of Earth, such as resource depletion. If the resources of space were opened to use and viable life-supporting habitats were built, Earth would no longer define the limitations of growth. Although many of Earth's resources are non-renewable, off-planet colonies could satisfy the majority of the planet's resource requirements. With the availability of extraterrestrial resources, demand on terrestrial ones would decline. Proponents of this idea include Stephen Hawking and Gerard K. O'Neill.
Others including cosmologist Carl Sagan and science fiction writers Arthur C. Clarke, and Isaac Asimov, have argued that shipping any excess population into space is not a viable solution to human overpopulation. According to Clarke, "the population battle must be fought or won here on Earth". The problem for these authors is not the lack of resources in space (as shown in books such as Mining the Sky), but the physical impracticality of shipping vast numbers of people into space to "solve" overpopulation on Earth.
Other arguments
Advocates for space colonization cite a presumed innate human drive to explore and discover, and call it a quality at the core of progress and thriving civilizations.
Nick Bostrom has argued that from a utilitarian perspective, space colonization should be a chief goal as it would enable a very large population to live for a very long time (possibly billions of years), which would produce an enormous amount of utility (or happiness). He claims that it is more important to reduce existential risks to increase the probability of eventual colonization than to accelerate technological development so that space colonization could happen sooner. In his paper, he assumes that the created lives will have positive ethical value despite the problem of suffering.
In a 2001 interview with Freeman Dyson, J. Richard Gott and Sid Goldstein, they were asked for reasons why some humans should live in space. Their answers were:
Spread life and beauty throughout the universe
Ensure the survival of our species
Make money through new forms of space commercialization such as solar-power satellites, asteroid mining, and space manufacturing
Save the environment of Earth by moving people and industry into space
Biotic ethics is a branch of ethics that values life itself. For biotic ethics, and their extension to space as panbiotic ethics, it is a human purpose to secure and propagate life and to use space to maximize life.
Difficulties
There would be many problems in colonizing the outer Solar System. These include:
Distance from Earth – The outer planets are much farther from Earth than the inner planets, and would therefore be harder and more time-consuming to reach. In addition, return voyages may well be prohibitive considering the time and distance.
Extreme cold – temperatures are near absolute zero in many parts of the outer Solar System.
Power – Solar power is many times less concentrated in the outer Solar System than in the inner Solar System. It is unclear as to whether it would be usable there, using some form of concentration mirrors, or whether nuclear power would be necessary. There have also been proposals to use the gravitational potential energy of planets or dwarf planets with moons.
Effects of low gravity on the human body – All moons of the gas giants and all outer dwarf planets have a very low gravity, the highest being Io's gravity (0.183 g) which is less than 1/5 of the Earth's gravity. Since the Apollo program all crewed spaceflight has been constrained to Low Earth orbit and there has been no opportunity to test the effects of such low gravitational accelerations on the human body. It is speculated (but not confirmed) that the low gravity environments might have very similar effects to long-term exposure in weightlessness. Such effects can be avoided by rotating spacecraft creating artificial gravity.
Dust – breathing risks associated with fine dust from rocky surface objects, for similar reasons as harmful effects of lunar dust.
Criticisms
Space colonization has been seen as a relief to the problem of human overpopulation as early as 1758, and listed as one of Stephen Hawking's reasons for pursuing space exploration. Critics note, however, that a slowdown in population growth rates since the 1980s has alleviated the risk of overpopulation.
Critics also argue that the costs of commercial activity in space are too high to be profitable against Earth-based industries, and hence that it is unlikely to see significant exploitation of space resources in the foreseeable future.
Other objections include concerns that the forthcoming colonization and commodification of the cosmos is likely to enhance the interests of the already powerful, including major economic and military institutions e.g. the large financial institutions, the major aerospace companies and the military–industrial complex, to lead to new wars, and to exacerbate pre-existing exploitation of workers and resources, economic inequality, poverty, social division and marginalization, environmental degradation, and other detrimental processes or institutions.
Additional concerns include creating a culture in which humans are no longer seen as human, but rather as material assets. The issues of human dignity, morality, philosophy, culture, bioethics, and the threat of megalomaniac leaders in these new "societies" would all have to be addressed in order for space colonization to meet the psychological and social needs of people living in isolated colonies.
As an alternative or addendum for the future of the human race, many science fiction writers have focused on the realm of the 'inner-space', that is the computer-aided exploration of the human mind and human consciousness—possibly en route developmentally to a Matrioshka Brain.
Robotic spacecraft are proposed as an alternative to gain many of the same scientific advantages without the limited mission duration and high cost of life support and return transportation involved in human missions.
A corollary to the Fermi paradox—"nobody else is doing it"—is the argument that, because no evidence of alien colonization technology exists, it is statistically unlikely to even be possible to use that same level of technology ourselves.
Colonialism
Space colonization has been discussed as postcolonial continuation of imperialism and colonialism, calling for decolonization instead of colonization. Critics argue that the present politico-legal regimes and their philosophic grounding, advantage imperialist development of space, that key decisionmakers in space colonization are often wealthy elites affiliated with private corporations, and that space colonization would primarily appeal to their peers rather than ordinary citizens. Furthermore, it is argued that there is a need for inclusive and democratic participation and implementation of any space exploration, infrastructure or habitation. According to space law expert Michael Dodge, existing space law, such as the Outer Space Treaty, guarantees access to space, but does not enforce social inclusiveness or regulate non-state actors.
Particularly the narrative of the "New Frontier" has been criticized as unreflected continuation of settler colonialism and manifest destiny, continuing the narrative of exploration as fundamental to the assumed human nature. Joon Yun considers space colonization as a solution to human survival and global problems like pollution to be imperialist; others have identified space as a new sacrifice zone of colonialism.
Furthermore the understanding of space as empty and separate is considered a continuation of terra nullius.
Natalie B. Trevino argues that not colonialism but coloniality will be carried into space if not reflected on.
More specifically the advocacy for territorial colonization of Mars has been called surfacism, in contrast to habitation in the atmospheric space of Venus, a concept similar to Thomas Golds surface chauvinism.
More generally space infrastructure such as the Mauna Kea Observatories have also been criticized and protested against as being colonialist. Guiana Space Centre has also been the site of anti-colonial protests, connecting colonization as an issue on Earth and in space.
In regard to the scenario of extraterrestrial first contact, it has been argued that the employment of colonial language would endanger such first impressions and encounters.
Furthermore spaceflight as a whole and space law more particularly has been criticized as a postcolonial project by being built on a colonial legacy and by not facilitating the sharing of access to space and its benefits, too often allowing spaceflight to be used to sustain colonialism and imperialism, most of all on Earth instead.
Planetary protection
Agencies conducting interplanetary missions are guided by COSPAR's planetary protection policies, to have at most 300,000 spores on the exterior of the craft—and more thoroughly sterilized if they contact "special regions" containing water, or it could contaminate life-detection experiments or the planet itself.
It is impossible to sterilize human missions to this level, as humans are host to typically a hundred trillion microorganisms of thousands of species of the human microbiome, and these cannot be removed while preserving the life of the human. Containment seems the only option, but it is a major challenge in the event of a hard landing (i.e. crash). There have been several planetary workshops on this issue, but with no final guidelines yet for a way forward. Human explorers could also inadvertently contaminate Earth if they return to the planet while carrying extraterrestrial microorganisms.
Physical and mental health risks to colonists
The health of the humans who may participate in a colonization venture would be subject to increased physical, mental and emotional risks. NASA learned that – without gravity – bones lose minerals, causing osteoporosis. Bone density may decrease by 1% per month, which may lead to a greater risk of osteoporosis-related fractures later in life. Fluid shifts towards to the head may cause vision problems. NASA found that isolation in closed environments aboard the International Space Station led to depression, sleep disorders, and diminished personal interactions, likely due to confined spaces and the monotony and boredom of long space flight. Circadian rhythm may also be susceptible to the effects of space life due to the effects on sleep of disrupted timing of sunset and sunrise. This can lead to exhaustion, as well as other sleep problems such as insomnia, which can reduce their productivity and lead to mental health disorders. High-energy radiation is a health risk that colonists would face, as radiation in deep space is deadlier than what astronauts face now in low Earth orbit. Metal shielding on space vehicles protects against only 25–30% of space radiation, possibly leaving colonists exposed to the other 70% of radiation and its short and long-term health complications.
Risk of astronomical suffering
Space colonization, while often seen as a bold step for humanity, is likely to result in catastrophic outcomes. The potential for creating vast suffering, including extreme forms, may outweight perceived benefits. Scholars like Phil Torres and Daniel Deudney argue that expansion into space could escalate perpetual conflict, insecurity, and even increase risks of human extinction. This aligns with the notion that space expansion amplifies both suffering in non-extinction scenarios and risks tied to advanced AI systems. Furthermore, the "astronomical atrocity problem" raises ethical concerns about whether positive outcomes can ever justify immense suffering. According to some authors, strategic approaches are crucial—if inevitable, space colonization should prioritize compassionate agents to mitigate risks of dystopian outcomes.
Locations
Space colonization has been envisioned at many different locations inside and outside the Solar System, but most commonly at Mars and the Moon.
Altogether it has been argued that space colonization extends from Earth, building on colonization of Earth, extending colonialism into space from colonial land on Earth and using it for spaceflight, as with Guiana Space Centre, and by building facilities for space colonization, as with Starbase. Extending as a system it often incorporates different locations from Earth, the orbital space around it and the Moon to almost any location beyond the Moon.
Near-Earth space
Earth orbit
Geostationary orbit was an early issue of discussion about space colonization, with equatorial countries argueing for special rights to the orbit (see Bogota Declaration).
Space debris, particularly in low Earth orbit, has been characterized as a product of colonization by occupying space and hindering access to space through excessive pollution with debris, with drastic increases in the course of military activity and without a lack of management.
Most of the delta-v budget, and thus propellant, of a launch is used bringing a spacecraft to low Earth orbit. This is the main reason why Jerry Pournelle said "If you can get your ship into orbit, you're halfway to anywhere". Therefore the main advantages to constructing a space settlement in Earth orbit are accessibility to the Earth and already-existing economic motives such as space hotels and space manufacturing. However, a big disadvantage is that orbit does not host any materials that is available for exploitation. Space colonization altogether might eventually demand lifting vast amounts of payload into orbit, making thousands of daily launches potentially unsustainable. Various theoretical concepts, such as orbital rings and skyhooks, have been proposed to reduce the cost of accessing space.
Moon
The Moon is discussed as a target for colonization, due to its proximity to Earth and lower escape velocity. The Moon is reachable from Earth in three days, has a near-instant communication to Earth, with minable minerals, no atmosphere, and low gravity, making it extremely easy to ship materials and products to orbit. Abundant ice is trapped in permanently shadowed craters near the poles, which could provide support for the water needs of a lunar colony, though indications that mercury is also similarly trapped there may pose health concerns. Native precious metals, such as gold, silver, and probably platinum, are also concentrated at the lunar poles by electrostatic dust transport. There are only a few materials on the Moon which have been identified to make economic sense to ship directly back to the Earth, which are helium-3 (for fusion power) and rare-earth minerals (for electronics). Instead, it makes more sense for these materials to be used in-space or being turned into valuable products for export. However, the Moon's lack of atmosphere provides no protection from space radiation or meteoroids, so lunar lava tubes have been proposed sites to gain protection. The Moon's low surface gravity is also a concern, as it is unknown whether 1/6g is enough to maintain human health for long periods.
Since the Moon has extreme temperature swings and toxic lunar regolith, it is argued by some that the Moon will not become a place of habitation, but instead attract polluting extraction and manufacturing industries. Furthermore it has been argued that moving these industries to the Moon could help protect the Earth's environment and allow poorer countries to be released from the shackles of neocolonialism by wealther countries. In the space colonization framework, the Moon will be transformed into an industrial hub of the Solar System.
Interest in establishing a moonbase has increased in the 21st century as an intermediate to Mars colonization.
The European Space Agency (ESA) head Jan Woerner at the International Astronautical Congress in Bremen, Germany, in October, 2018 proposed cooperation among countries and companies on lunar capabilities, a concept referred to as Moon Village.
In a December 2017 directive, the first Trump administration steered NASA to include a lunar mission on the pathway to other beyond Earth orbit (BEO) destinations.
In 2023, the U.S. Defense Department started a study of the necessary infrastructure and capabilities required to develop a moon-based economy over the following ten years.
As of 2024 on the one side China, together with other countries, has declared the intend to establish its International Lunar Research Station, and on the other side the United States which is proceeding with partner countries with its Artemis program including Moonbases at the poles near permanently shadowed craters in the 2030s. The Chinese Lunar Exploration Program has been identified as to bolster China's political influence and enhance its bid for superpower status, and the United States seeking to maintain its position as the leading space power.
Lagrange points
Another near-Earth possibility are the stable Earth–Moon Lagrange points and , at which point a space colony can float indefinitely. The L5 Society was founded to promote settlement by building space stations at these points. Gerard K. O'Neill suggested in 1974 that the L5 point, in particular, could fit several thousand floating colonies, and would allow easy travel to and from the colonies due to the shallow effective potential at this point.
Mars
The hypothetical colonization of Mars has received interest from public space agencies and private corporations and has received extensive treatment in science fiction writing, film, and art.
While there have been many plans for a human Mars mission, including affordable ones such as Mars Direct, none has been realized as of 2024. Both the United States and China has plans to send humans to Mars sometime in the 2040s, but these plans are not backed with hardware and funding. However, SpaceX is currently developing Starship, a super-heavy-lift reusable launch vehicle, with a vision of sending humans to Mars. As of November 2024, the company plans to send five uncrewed Starships to Mars in either 2026 or 2028–2029 launch windows and SpaceX's CEO Elon Musk has repeatingly stated to back the Mars efforts financially and politically.
Mars is more suitable for habitation than the Moon, with a stronger gravity, rich amount of materials needed for life, day/night cycle nearly identical to Earth, and a thin atmosphere to protect from micrometeroids. The main disadvantage of Mars compared to the Moon is the six-to-nine-month transit time and the lengthy launch window, which occurs approximately every two years. Without in situ resource utlization, Mars colonization would be nearly impossible as it would require bringing thousands of tons of payload to sustain a handful of astronauts. If Martian materials can be used to make propellant (such as methane with the Sabatier process) and supplies (such as oxygen for crews), the amount of supplies needed to bring to Mars can be greatly reduced. Even then, Mars colonies will not be economically viable in the near term, thus reasons for colonizing Mars will be mostly ideological and prestige-based, such as a desire for freedom.
Other inner Solar System bodies
Mercury
Mercury is rich of metals and volatiles, as well as solar energy. However, Mercury is the most energy-consuming body on the Solar System to land for spacecraft launching from Earth, and astronauts there must contend with the extreme temperature differential and radiation.
Once thought to be a volatile-depleted body like the Moon, Mercury is now known to be volatile-rich, surprisingly richer in volatiles than any other terrestrial body in the inner Solar System. The planet also receives six and a half times the solar flux as the Earth/Moon system, making solar energy an effective energy source; it could be harnessed through orbital solar arrays and beamed to the surface or exported to other planets.
Geologist Stephen Gillett suggested in 1996, that this could make Mercury an ideal place to build and launch solar sail spacecraft, which could launch as folded "chunks" by a mass driver from Mercury's surface. Once in space, the solar sails would deploy. Solar energy for the mass driver should be easy to produce, and solar sails near Mercury would have 6.5 times the thrust they do near Earth. This could make Mercury an ideal place to acquire materials useful in building hardware to send to (and terraform) Venus. Vast solar collectors could also be built on or near Mercury to produce power for large-scale engineering activities such as laser-pushed light sails to nearby star systems.
As Mercury has essentially no axial tilt, crater floors near its poles lie in eternal darkness, never seeing the Sun. They function as cold traps, trapping volatiles for geological periods. It is estimated that the poles of Mercury contain 1014–1015 kg of water, likely covered by about 5.65×109 m3 of hydrocarbons. This would make agriculture possible. It has been suggested that plant varieties could be developed to take advantage of the high light intensity and the long day of Mercury. The poles do not experience the significant day-night variations the rest of Mercury do, making them the best place on the planet to begin a colony.
Another option is to live underground, where day-night variations would be damped enough that temperatures would stay roughly constant. There are indications that Mercury contains lava tubes, like the Moon and Mars, which would be suitable for this purpose. Underground temperatures in a ring around Mercury's poles can reach room temperature on Earth, 22±1 °C; and this is achieved at depths starting from about 0.7 m. This presence of volatiles and abundance of energy has led Alexander Bolonkin and James Shifflett to consider Mercury preferable to Mars for colonization.
Yet a third option could be to continually move to stay on the night side, as Mercury's 176-day-long day-night cycle means that the terminator travels very slowly.
Because Mercury is very dense, its surface gravity is 0.38g like Mars, even though it is a smaller planet. This would be easier to adjust to than lunar gravity (0.16g), but presents advantages regarding lower escape velocity from Mercury than from Earth. Mercury's proximity gives it advantages over the asteroids and outer planets, and its low synodic period means that launch windows from Earth to Mercury are more frequent than those from Earth to Venus or Mars.
On the downside, a Mercury colony would require significant shielding from radiation and solar flares, and since Mercury is airless, decompression and temperature extremes would be constant risks.
Venus
Though the surface of Venus is extremely hostile, habitats high above the atmosphere of Venus are fairly habitable, with a temperature of around 50 °C and a pressure similar to the Earth's sea level. However, beside tourism opportunities, the economic benefit of a Venusian colonies is minimal.
Asteroid belt
Asteroids can provide enough material in the form of water, air, fuel, metal, soil, and nutrients to support ten to a hundred trillion humans in space. Many asteroids contain minerals that are inheriently valuable, such as rare earths and precious metals. However, low gravity, distance from Earth and disperse nature of their orbits make it difficult to settle on small asteroids.
Giant planets
There have also been proposals to place robotic aerostats in the upper atmospheres of the Solar System's giant planets for exploration and possibly mining of helium-3, which could have a very high value per unit mass as a thermonuclear fuel.
Robert Zubrin identified Saturn, Uranus and Neptune as "the Persian Gulf of the Solar System", as the largest sources of deuterium and helium-3 to drive a fusion economy, with Saturn the most important and most valuable of the three, because of its relative proximity, low radiation, and large system of moons. On the other hand, planetary scientist John Lewis in his 1997 book Mining the Sky, insists that Uranus is the likeliest place to mine helium-3 because of its significantly shallower gravity well, which makes it easier for a laden tanker spacecraft to thrust itself away. Furthermore, Uranus is an ice giant, which would likely make it easier to separate the helium from the atmosphere.
Because Uranus has the lowest escape velocity of the four giant planets, it has been proposed as a mining site for helium-3. If human supervision of the robotic activity proved necessary, one of Uranus's natural satellites might serve as a base.
It is hypothesized that one of Neptune's satellites could be used for colonization. Triton's surface shows signs of extensive geological activity that implies a subsurface ocean, perhaps composed of ammonia/water. If technology advanced to the point that tapping such geothermal energy was possible, it could make colonizing a cryogenic world like Triton feasible, supplemented by nuclear fusion power.
Moons of outer planets
Human missions to the outer planets would need to arrive quickly due to the effects of space radiation and microgravity along the journey. In 2012, Thomas B. Kerwick wrote that the distance to the outer planets made their human exploration impractical for now, noting that travel times for round trips to Mars were estimated at two years, and that the closest approach of Jupiter to Earth is over ten times farther than the closest approach of Mars to Earth. However, he noted that this could change with "significant advancement on spacecraft design". Nuclear-thermal or nuclear-electric engines have been suggested as a way to make the journey to Jupiter in a reasonable amount of time. Another possibility would be plasma magnet sails, a technology already suggested for rapidly sending a probe to Jupiter. The cold would also be a factor, necessitating a robust source of heat energy for spacesuits and bases. Most of the larger moons of the outer planets contain water ice, liquid water, and organic compounds that might be useful for sustaining human life.
Robert Zubrin has suggested Saturn, Uranus, and Neptune as advantageous locations for colonization because their atmospheres are good sources of fusion fuels, such as deuterium and helium-3. Zubrin suggested that Saturn would be the most important and valuable as it is the closest and has an extensive satellite system. Jupiter's high gravity makes it difficult to extract gases from its atmosphere, and its strong radiation belt makes developing its system difficult. On the other hand, fusion power has yet to be achieved, and fusion power from helium-3 is more difficult to achieve than conventional deuterium–tritium fusion. Jeffrey Van Cleve, Carl Grillmair, and Mark Hanna instead focus on Uranus, because the delta-v required to get helium-3 from the atmosphere into orbit is half that needed for Jupiter, and because Uranus' atmosphere is five times richer in helium than Saturn's.
Jupiter's Galilean moons (Io, Europa, Ganymede, and Callisto) and Saturn's Titan are the only moons that have gravities comparable to Earth's Moon. The Moon has a 0.17g gravity; Io, 0.18g; Europa, 0.13g; Ganymede, 0.15g; Callisto, 0.13g; and Titan, 0.14g. Neptune's Triton has about half the Moon's gravity (0.08g); other round moons provide even less (starting from Uranus' Titania and Oberon at about 0.04g).
Jovian moons
The Jovian system in general has particular disadvantages for colonization, including a deep gravity well. The magnetosphere of Jupiter bombards the moons of Jupiter with intense ionizing radiation delivering about 36 Sv per day to unshielded colonists on Io and about 5.40 Sv per day on Europa. Exposure to about 0.75 Sv over a few days is enough to cause radiation poisoning, and about 5 Sv over a few days is fatal.
Jupiter itself, like the other gas giants, has further disadvantages. There is no accessible surface on which to land, and the light hydrogen atmosphere would not provide good buoyancy for some kind of aerial habitat as has been proposed for Venus.
Radiation levels on Io and Europa are extreme, enough to kill unshielded humans within an Earth day. Therefore, only Callisto and perhaps Ganymede could reasonably support a human colony. Callisto orbits outside Jupiter's radiation belt. Ganymede's low latitudes are partially shielded by the moon's magnetic field, though not enough to completely remove the need for radiation shielding. Both of them have available water, silicate rock, and metals that could be mined and used for construction.
Although Io's volcanism and tidal heating constitute valuable resources, exploiting them is probably impractical. Europa is rich in water (its subsurface ocean is expected to contain over twice as much water as all Earth's oceans together) and likely oxygen, but metals and minerals would have to be imported. If alien microbial life exists on Europa, human immune systems may not protect against it. Sufficient radiation shielding might, however, make Europa an interesting location for a research base. The private Artemis Project drafted a plan in 1997 to colonize Europa, involving surface igloos as bases to drill down into the ice and explore the ocean underneath, and suggesting that humans could live in "air pockets" in the ice layer. Ganymede and Callisto are also expected to have internal oceans. It might be possible to build a surface base that would produce fuel for further exploration of the Solar System.
In 2003, NASA performed a study called HOPE (Revolutionary Concepts for Human Outer Planet Exploration) regarding the future exploration of the Solar System. The target chosen was Callisto due to its distance from Jupiter, and thus the planet's harmful radiation. It could be possible to build a surface base that would produce fuel for further exploration of the Solar System. HOPE estimated a round trip time for a crewed mission of about 2–5 years, assuming significant progress in propulsion technologies.
Io is not ideal for colonization, due to its hostile environment. The moon is under influence of high tidal forces, causing high volcanic activity. Jupiter's strong radiation belt overshadows Io, delivering 36 Sv a day to the moon. The moon is also extremely dry. Io is the least ideal place for the colonization of the four Galilean moons.
Despite this, its volcanoes could be energy resources for the other moons, which are better suited to colonization.
Ganymede is the largest moon in the Solar System. Ganymede is the only moon with a magnetosphere, albeit overshadowed by Jupiter's magnetic field. Because of this magnetic field, Ganymede is one of only two Jovian moons where surface settlements would be feasible because it receives about 0.08 Sv of radiation per day. Ganymede could be terraformed.
The Keck Observatory announced in 2006 that the binary Jupiter trojan 617 Patroclus, and possibly many other Jupiter trojans, are likely composed of water ice, with a layer of dust. This suggests that mining water and other volatiles in this region and transporting them elsewhere in the Solar System, perhaps via the proposed Interplanetary Transport Network, may be feasible in the not-so-distant future. This could make colonization of the Moon, Mercury and main-belt asteroids more practical.
Saturn
Saturn's radiation belt is much weaker than Jupiter's, so radiation is less of an issue here. Dione, Rhea, Titan, and Iapetus all orbit outside the radiation belt, and Titan's thick atmosphere would adequately shield against cosmic radiation.
Saturn has seven moons large enough to be round: in order of increasing distance from Saturn, they are Mimas, Enceladus, Tethys, Dione, Rhea, Titan, and Iapetus.
Enceladus
The small moon Enceladus is also of interest, having a subsurface ocean that is separated from the surface by only tens of meters of ice at the south pole, compared to kilometers of ice separating the ocean from the surface on Europa. Volatile and organic compounds are present there, and the moon's high density for an ice world (1.6 g/cm3) indicates that its core is rich in silicates.
On 9 March 2006, NASA's Cassini space probe found possible evidence of liquid water on Enceladus. According to that article, "pockets of liquid water may be no more than tens of meters below the surface." These findings were confirmed in 2014 by NASA. This means liquid water could be collected much more easily and safely on Enceladus than, for instance, on Europa (see above). Discovery of water, especially liquid water, generally makes a celestial body a much more likely candidate for colonization. An alternative model of Enceladus's activity is the decomposition of methane/water clathrates – a process requiring lower temperatures than liquid water eruptions. The higher density of Enceladus indicates a larger than Saturnian average silicate core that could provide materials for base operations.
Titan
Trans-Neptunian region
Beyond the Solar System
Beyond the Solar System colonization targets might be identified in the surrounding stars. The main difficulty is the vast distances to other stars.
To reach such targets travel times of millennia would be necessary, with current technology. At average speeds of even 0.1% of the speed of light (c) interstellar expansion across the entire Milky Way galaxy would take up to one-half of the Sun's galactic orbital period of ~240,000,000 years, which is comparable to the timescale of other galactic processes. Due to fundamental energy and reaction mass consideration such speeds would be with current technology limited to small spaceships. If humanity would gain access to a large amount of energy, on the order of the mass-energy of entire planets, it may become possible to construct spaceships with Alcubierre drives.
The following are plausible approaches with current technology:
A generation ship which would travel much slower than light, with consequent interstellar trip times of many decades or centuries. The crew would go through generations before the journey was complete, so none of the initial crew would be expected to survive to arrive at the destination, assuming current human lifespans.
A sleeper ship, where most or all of the crew spend the journey in some form of hibernation or suspended animation, allowing some or all to reach the destination.
An embryo-carrying interstellar starship (EIS), much smaller than a generation ship or sleeper ship, transporting human embryos or DNA in a frozen or dormant state to the destination. (Obvious biological and psychological problems in birthing, raising, and educating such voyagers, neglected here, may not be fundamental.)
A nuclear fusion or fission powered ship (e.g. ion drive) of some kind, achieving velocities of up to perhaps 10% c permitting one-way trips to nearby stars with durations comparable to a human lifetime.
A Project Orion-ship, a nuclear-powered concept proposed by Freeman Dyson which would use nuclear explosions to propel a starship. A special case of the preceding nuclear rocket concepts, with similar potential velocity capability, but possibly easier technology.
Laser propulsion concepts, using some form of beaming of power from the Solar System might allow a light-sail or other ship to reach high speeds, comparable to those theoretically attainable by the fusion-powered electric rocket, above. These methods would need some means, such as supplementary nuclear propulsion, to stop at the destination, but a hybrid (light-sail for acceleration, fusion-electric for deceleration) system might be possible.
Uploaded human minds or artificial intelligence may be transmitted via radio or laser at light speed to interstellar destinations where self-replicating spacecraft have traveled subluminally and set up infrastructure and possibly also brought some minds. Extraterrestrial intelligence might be another viable destination.
Intergalactic travel
The distances between galaxies are on the order of a million times farther than those between the stars, and thus intergalactic colonization would involve voyages of millions of years via special self-sustaining methods.
Implementation
Building colonies in space would require access to water, food, space, people, construction materials, energy, transportation, communications, life support, simulated gravity, radiation protection, migration, governance and capital investment. It is likely the colonies would be located near the necessary physical resources. The practice of space architecture seeks to transform spaceflight from a heroic test of human endurance to a normality within the bounds of comfortable experience. As is true of other frontier-opening endeavors, the capital investment necessary for space colonization would probably come from governments, an argument made by John Hickman and Neil deGrasse Tyson.
Migration
Human spaceflight has enabled only temporarily relocating a few privileged people and no permanent space migrants.
The societal motivation for space migration has been questioned as rooted in colonialism, questioning the fundamentals and inclusivity of space colonization. Highlighting the need to reflect on such socio-economic issues beside the technical challenges for implementation.
Governance
A range of different models of transplanetary or extraterrestrial governance have been sketched or proposed. Often envisioning the need for a fresh or independent extraterrestrial governance, particularly in the void left by the contemporarily criticized lack of space governance and inclusivity.
It has been argued that space colonialism would, similarly to terrestrial settler colonialism, produce colonial national identities.
Federalism has been studied as a remedy of such distant and autonomous communities.
Life support
In space settlements, a life support system must recycle or import all the nutrients without "crashing." The closest terrestrial analogue to space life support is possibly that of a nuclear submarine. Nuclear submarines use mechanical life support systems to support humans for months without surfacing, and this same basic technology could presumably be employed for space use. However, nuclear submarines run "open loop"—extracting oxygen from seawater, and typically dumping carbon dioxide overboard, although they recycle existing oxygen. Another commonly proposed life-support system is a closed ecological system such as Biosphere 2.
Solutions to health risks
Although there are many physical, mental, and emotional health risks for future colonists and pioneers, solutions have been proposed to correct these problems. Mars500, HI-SEAS, and SMART-OP represent efforts to help reduce the effects of loneliness and confinement for long periods of time. Keeping contact with family members, celebrating holidays, and maintaining cultural identities all had an impact on minimizing the deterioration of mental health. There are also health tools in development to help astronauts reduce anxiety, as well as helpful tips to reduce the spread of germs and bacteria in a closed environment. Radiation risk may be reduced for astronauts by frequent monitoring and focusing work to minimize time away from shielding. Future space agencies can also ensure that every colonist would have a mandatory amount of daily exercise to prevent degradation of muscle.
Radiation protection
Cosmic rays and solar flares create a lethal radiation environment in space. In orbit around certain planets with magnetospheres (including Earth), the Van Allen belts make living above the atmosphere difficult. To protect life, settlements must be surrounded by sufficient mass to absorb most incoming radiation, unless magnetic or plasma radiation shields are developed. In the case of Van Allen belts, these could be drained using orbiting tethers or radio waves.
Passive mass shielding of four metric tons per square meter of surface area will reduce radiation dosage to several mSv or less annually, well below the rate of some populated high natural background areas on Earth. This can be leftover material (slag) from processing lunar soil and asteroids into oxygen, metals, and other useful materials. However, it represents a significant obstacle to manoeuvering vessels with such massive bulk (mobile spacecraft being particularly likely to use less massive active shielding). Inertia would necessitate powerful thrusters to start or stop rotation, or electric motors to spin two massive portions of a vessel in opposite senses. Shielding material can be stationary around a rotating interior.
Psychological adjustment
The monotony and loneliness that comes from a prolonged space mission can leave astronauts susceptible to cabin fever or having a psychotic break. Moreover, lack of sleep, fatigue, and work overload can affect an astronaut's ability to perform well in an environment such as space where every action is critical.
Economics
Space colonization can roughly be said to be possible when the necessary methods of space colonization become cheap enough (such as space access by cheaper launch systems) to meet the cumulative funds that have been gathered for the purpose, in addition to estimated profits from commercial use of space.
Although there are no immediate prospects for the large amounts of money required for space colonization to be available given traditional launch costs, there is some prospect of a radical reduction to launch costs in the 2010s, which would consequently lessen the cost of any efforts in that direction. With a published price of per launch of up to payload to low Earth orbit, SpaceX Falcon 9 rockets are already the "cheapest in the industry". Advancements currently being developed as part of the SpaceX reusable launch system development program to enable reusable Falcon 9s "could drop the price by an order of magnitude, sparking more space-based enterprise, which in turn would drop the cost of access to space still further through economies of scale." If SpaceX is successful in developing the reusable technology, it would be expected to "have a major impact on the cost of access to space", and change the increasingly competitive market in space launch services.
The President's Commission on Implementation of United States Space Exploration Policy suggested that an inducement prize should be established, perhaps by government, for the achievement of space colonization, for example by offering the prize to the first organization to place humans on the Moon and sustain them for a fixed period before they return to Earth.
Money and currency
Experts have debated on the possible use of money and currencies in societies that will be established in space. The Quasi Universal Intergalactic Denomination, or QUID, is a physical currency made from a space-qualified polymer PTFE for inter-planetary travelers. QUID was designed for the foreign exchange company Travelex by scientists from Britain's National Space Centre and the University of Leicester.
Other possibilities include the incorporation of cryptocurrency as the primary form of currency, as suggested by Elon Musk.
Resources
Colonies on the Moon, Mars, asteroids, or the metal-rich planet Mercury, could extract local materials. The Moon is deficient in volatiles such as argon, helium and compounds of carbon, hydrogen and nitrogen. The LCROSS impacter was targeted at the Cabeus crater which was chosen as having a high concentration of water for the Moon. A plume of material erupted in which some water was detected. Mission chief scientist Anthony Colaprete estimated that the Cabeus crater contains material with 1% water or possibly more. Water ice should also be in other permanently shadowed craters near the lunar poles. Although helium is present only in low concentrations on the Moon, where it is deposited into regolith by the solar wind, an estimated million tons of He-3 exists over all. It also has industrially significant oxygen, silicon, and metals such as iron, aluminium, and titanium.
Launching materials from Earth is expensive, so bulk materials for colonies could come from the Moon, a near-Earth object (NEO), Phobos, or Deimos. The benefits of using such sources include: a lower gravitational force, no atmospheric drag on cargo vessels, and no biosphere to damage. Many NEOs contain substantial amounts of metals. Underneath a drier outer crust (much like oil shale), some other NEOs are inactive comets which include billions of tons of water ice and kerogen hydrocarbons, as well as some nitrogen compounds.
Farther out, Jupiter's Trojan asteroids are thought to be rich in water ice and other volatiles.
Recycling of some raw materials would almost certainly be necessary.
Energy
Solar energy in orbit is abundant, reliable, and is commonly used to power satellites today. There is no night in free space, and no clouds or atmosphere to block sunlight. Light intensity obeys an inverse-square law. So the solar energy available at distance d from the Sun is E = 1367/d2 W/m2, where d is measured in astronomical units (AU) and 1367 watts/m2 is the energy available at the distance of Earth's orbit from the Sun, 1 AU.
In the weightlessness and vacuum of space, high temperatures for industrial processes can easily be achieved in solar ovens with huge parabolic reflectors made of metallic foil with very lightweight support structures. Flat mirrors to reflect sunlight around radiation shields into living areas (to avoid line-of-sight access for cosmic rays, or to make the Sun's image appear to move across their "sky") or onto crops are even lighter and easier to build.
Large solar power photovoltaic cell arrays or thermal power plants would be needed to meet the electrical power needs of the settlers' use. In developed parts of Earth, electrical consumption can average 1 kilowatt/person (or roughly 10 megawatt-hours per person per year.) These power plants could be at a short distance from the main structures if wires are used to transmit the power, or much farther away with wireless power transmission.
A major export of the initial space settlement designs was anticipated to be large solar power satellites (SPS) that would use wireless power transmission (phase-locked microwave beams or lasers emitting wavelengths that special solar cells convert with high efficiency) to send power to locations on Earth, or to colonies on the Moon or other locations in space. For locations on Earth, this method of getting power is extremely benign, with zero emissions and far less ground area required per watt than for conventional solar panels. Once these satellites are primarily built from lunar or asteroid-derived materials, the price of SPS electricity could be lower than energy from fossil fuel or nuclear energy; replacing these would have significant benefits such as the elimination of greenhouse gases and nuclear waste from electricity generation.
Transmitting solar energy wirelessly from the Earth to the Moon and back is also an idea proposed for the benefit of space colonization and energy resources. Physicist Dr. David Criswell, who worked for NASA during the Apollo missions, proposed the idea of using power beams to transfer energy from space. These beams, microwaves with a wavelength of about 12 cm, would be almost untouched as they travel through the atmosphere. They could also be aimed at more industrial areas to keep away from humans or animal activities. This would allow for safer and more reliable methods of transferring solar energy.
In 2008, scientists were able to send a 20 watt microwave signal from a mountain on the island of Maui to the island of Hawaii. Since then JAXA and Mitsubishi have been working together on a $21 billion project to place satellites in orbit which could generate up to 1 gigawatt of energy. These are the next advancements being done today to transmit energy wirelessly for space-based solar energy.
However, the value of SPS power delivered wirelessly to other locations in space will typically be far higher than to Earth. Otherwise, the means of generating the power would need to be included with these projects and pay the heavy penalty of Earth launch costs. Therefore, other than proposed demonstration projects for power delivered to Earth, the first priority for SPS electricity is likely to be locations in space, such as communications satellites, fuel depots or "orbital tugboat" boosters transferring cargo and passengers between low Earth orbit (LEO) and other orbits such as geosynchronous orbit (GEO), lunar orbit or highly-eccentric Earth orbit (HEEO). The system will also rely on satellites and receiving stations on Earth to convert the energy into electricity. Because this energy can be transmitted easily from dayside to nightside, power would be reliable 24/7.
Nuclear power is sometimes proposed for colonies located on the Moon or on Mars, as the supply of solar energy is too discontinuous in these locations; the Moon has nights of two Earth weeks in duration. Mars has nights, relatively high gravity, and an atmosphere featuring large dust storms to cover and degrade solar panels. Also, Mars' greater distance from the Sun (1.52 astronomical units, AU) means that only 1/1.522 or about 43% of the solar energy is available at Mars compared with Earth orbit. Another method would be transmitting energy wirelessly to the lunar or Martian colonies from solar power satellites (SPSs) as described above; the difficulties of generating power in these locations make the relative advantages of SPSs much greater there than for power beamed to locations on Earth. In order to also be able to fulfill the requirements of a Moon base and energy to supply life support, maintenance, communications, and research, a combination of both nuclear and solar energy may be used in the first colonies.
For both solar thermal and nuclear power generation in airless environments, such as the Moon and space, and to a lesser extent the very thin Martian atmosphere, one of the main difficulties is dispersing the inevitable heat generated. This requires fairly large radiator areas.
Self-replication
Space manufacturing could enable self-replication. Some consider it the ultimate goal because it would allow an exponential increase in colonies, while eliminating costs to, and dependence on, Earth. It could be argued that the establishment of such a colony would be Earth's first act of self-replication. Intermediate goals include colonies that expect only information from Earth (science, engineering, entertainment) and colonies that just require periodic supply of light weight objects, such as integrated circuits, medicines, genetic material and tools.
Population size
In 2002, the anthropologist John H. Moore estimated that a population of 150–180 would permit a stable society to exist for 60 to 80 generations—equivalent to 2,000 years.
Assuming a journey of 6,300 years, the astrophysicist Frédéric Marin and the particle physicist Camille Beluffi calculated that the minimum viable population for a generation ship to reach Proxima Centauri would be 98 settlers at the beginning of the mission (then the crew will breed until reaching a stable population of several hundred settlers within the ship).
In 2020, Jean-Marc Salotti proposed a method to determine the minimum number of settlers to survive on an extraterrestrial world. It is based on the comparison between the required time to perform all activities and the working time of all human resources. For Mars, 110 individuals would be required.
Advocacy
Several private companies have announced plans toward the colonization of Mars. Among entrepreneurs leading the call for space colonization are Elon Musk, Dennis Tito and Bas Lansdorp.
Involved organizations
Organizations that contribute to space colonization include:
The National Space Society (NSS) is an organization with the vision of people living and working in thriving communities beyond the Earth. The NSS also maintains an extensive library of full-text articles and books on space settlement.
The Space Frontier Foundation performs space advocacy including strong free market, capitalist views about space development.
The Mars Society promotes Robert Zubrin's Mars Direct plan and the settlement of Mars.
The Space Settlement Institute is searching for ways to make space colonization happen within a lifetime.
SpaceX is developing extensive spaceflight transportation infrastructure with the express purpose of enabling long-term human settlement of Mars.
The Space Studies Institute funds the study of outer space settlements, especially O'Neill cylinders.
The Alliance to Rescue Civilization plans to establish backups of human civilization on the Moon and other locations away from Earth.
The Artemis Project plans to set up a private lunar surface station.
The British Interplanetary Society (BIS) promotes ideas for the exploration and use of space, including a Mars colony, future propulsion systems (see Project Daedalus), terraforming, and locating other habitable worlds.
In June 2013 the BIS began the SPACE project to re-examine Gerard O'Neill's 1970s space colony studies in light of the advances made since then. The progress of this effort were detailed in a special edition of the BIS journal in September 2019.
Asgardia (nation) – an organization searching to circumvent limitations placed by Outer Space Treaty.
The Cyprus Space Exploration Organisation promotes space exploration and colonization, and fosters collaboration in space.
Terrestrial analogues to space settlement
Many space agencies build "testbeds", which are facilities on Earth for testing advanced life support systems, but these are designed for long duration human spaceflight, not permanent colonization.
The most famous attempt to build an analogue to a self-sufficient settlement is Biosphere 2, which attempted to duplicate Earth's biosphere.
BIOS-3 is another closed ecosystem, completed in 1972 in Krasnoyarsk, Siberia.
The Mars Desert Research Station has a habitat for similar reasons, but the surrounding climate is not strictly inhospitable.
Devon Island Mars Arctic Research Station, can also provide some practice for off-world outpost construction and operation.
In media and fiction
Although established space habitats are a stock element in science fiction stories, fictional works that explore the themes, social or practical, of the settlement and occupation of a habitable world are more rare.
Solaris is noted for its critique of space colonization of inhabited planets. At one point, one of the characters says:
In 2022 Rudolph Herzog and Werner Herzog presented an in-depth documentary with Lucianne Walkowicz called Last exit: Space.
See also
Asteroid mining
Bernal sphere
Billionaire space race
Colonisation (biology)
Colonization of Antarctica
Directed panspermia
Domed city
Extraterrestrial liquid water
Extraterrestrial real estate
Human outpost
Human presence in space
Lagrange point colonization
Mars analog habitat
Mars One
Mars to Stay
Megastructure
NewSpace
MELiSSA
Ocean colonization
O'Neill Cylinder
Planetary habitability
Solar analog
Space archaeology
Space habitat
Politics of outer space
Space law
Spome
Stanford torus
Terraforming
Timeline of Solar System exploration
Underground city
References
Further reading
Papers
Yap, Xiao-Shan & Rakhyun E. Kim (2023). "Towards Earth-Space Governance in a Multi-Planetary Era". Earth System Governance, 16: 100173.
Also see .
.
Video
Posted on the official YouTube channel of Casina Pio IV.
Affordable to everyone spaceflight is the key to building a spacefaring civilization. Posted on Vimeo.
Astropolitics
Science fiction themes
Spaceflight concepts
Open problems
Colonialism
Solar System | Space colonization | Astronomy | 14,129 |
18,444,188 | https://en.wikipedia.org/wiki/Constantiana%20Daphne | Daphne was a Roman fortification inaugurated, most probably in 327, on the left bank of the Danube, across Transmarisca, in the delta of the Arges river. In 367, emperor Valens crossed the Danube at Daphne using a pontoon bridge. Chronicler George Kedrenos, recounting the fight between the Varangians of Sveinald (Sviatoslav) and Emperor Ioan Tzimiskes in 971, mentioned the existence of wheat and millet sowings in the regions on the left bank of the Danube, which proves that this area was inhabited by a sedentary population. Encircled in Durostor (today Silistra), the Varangian armies supplied themselves at night with these grains and fodder transported from the opposite bank of the Danube. The same chronicler wrote that: "there came to him (before the emperor) from Constantia and other fortresses built beyond the Istru, messengers asking forgiveness for the evil deeds committed, surrendering together with those fortresses; receiving them gently, the emperor sent men to take possession of the cities and sufficient armies to guard them.”
It was mentioned by Ammianus Marcellinus and Procopius of Caesarea.
The most probable position is at Grădiștea at south west of Ulmeni. Still some historians believe that the Daphne was the new name of the Sucidava- Celei.
References
327 establishments
Buildings and structures completed in the 4th century
Byzantine military architecture
Roman auxiliary forts in Romania
4th-century fortifications
320s establishments in the Roman Empire
History of Muntenia | Constantiana Daphne | Engineering | 329 |
33,473,923 | https://en.wikipedia.org/wiki/Dra%C4%8Da | Drača () is a village in the municipality of Stanovo, Serbia. According to the preliminary results of the 2011 census, the village has a population of 911 people. In the domain of the village, cca 7 kilometres from the centre of the city of Kragujevac, the geographical centre of Serbia is located.
References
Populated places in Šumadija District
Geographical centres | Drača | Physics,Mathematics | 79 |
51,758,582 | https://en.wikipedia.org/wiki/Cell%20division%20orientation | Cell division orientation is the direction along which the new daughter cells are formed. Cell division orientation is important for morphogenesis, cell fate and tissue homeostasis. Abnormalities in the cell division orientation leads to the malformations during development and cancerous tissues. Factors that influence cell division orientation are cell shape, anisotropic localization of specific proteins and mechanical tensions.
Implication for morphogenesis
Cell division orientation is one of the mechanisms that shapes tissue during development and morphogenesis. Along with cell shape changes, cell rearrangements, apoptosis and growth, oriented cell division modifies the geometry and topology of live tissue in order to create new organs and shape the organisms. Reproducible patterns of oriented cell divisions were described during morphogenesis of Drosophila embryos, Arabidopsis thaliana embryos, Drosophila pupa, zebrafish embryos and mouse early embryos. Oriented cell divisions contribute to the tissue elongation and the release of mechanical stress. While in the first case oriented cell division acts as active contributor to the morphogenesis, the latter case is a passive response to the external mechanical tensions.
Implication for tissue homeostasis
In several tissues, such as columnar epithelium, the cells divide along the plane of the epithelium. Such divisions insert new formed cells in the epithelium layer. The disregulation of the orientation of cell divisions result in the creation of the cell out of epithelium and is observed at the initial stages of cancer.
Regulation
More than a century ago Oskar Hertwig proposed that the cell division orientation is determined by the shape of the cell (1884), known as Hertwig rule. In the epithelium the cells 'reads' its shape through the specific cell junction called tricellular junctions (TCJ). TCJ provide mechanical and geometrical clues for the spindle apparatus to ensure that cell divide along its long axis. Several factors could regulate cell shape and therefore orientation of cell division. Among these factors is the anisotropic mechanical stress. This stress could be the result of the external mechanical deformation of generated intracellularly by non-isotropic localization of specific proteins.
References
Cell biology
Cell anatomy
Cell cycle
Cellular processes
Developmental biology
Morphology (biology) | Cell division orientation | Biology | 473 |
48,232 | https://en.wikipedia.org/wiki/Phenyl%20group | In organic chemistry, the phenyl group, or phenyl ring, is a cyclic group of atoms with the formula , and is often represented by the symbol Ph (archaically φ) or Ø. The phenyl group is closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, which may be replaced by some other element or compound to serve as a functional group. A phenyl group has six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry. Although often depicted with alternating double and single bonds, the phenyl group is chemically aromatic and has equal bond lengths between carbon atoms in the ring.
Nomenclature
Usually, a "phenyl group" is synonymous with and is represented by the symbol Ph (archaically, Φ), or Ø. Benzene is sometimes denoted as PhH. Phenyl groups are generally attached to other atoms or groups. For example, triphenylmethane () has three phenyl groups attached to the same carbon center. Many or even most phenyl compounds are not described with the term "phenyl". For example, the chloro derivative is normally called chlorobenzene, although it could be called phenyl chloride. In special (and rare) cases, isolated phenyl groups are detected: the phenyl anion (), the phenyl cation (), and the phenyl radical ().
Although Ph and phenyl uniquely denote , substituted derivatives also are described using the phenyl terminology. For example, is nitrophenyl, and is pentafluorophenyl. Monosubstituted phenyl groups (that is, disubstituted benzenes) are associated with electrophilic aromatic substitution reactions and the products follow the arene substitution pattern. So, a given substituted phenyl compound has three isomers, ortho (1,2-disubstitution), meta (1,3-disubstitution) and para (1,4-disubstitution). A disubstituted phenyl compound (trisubstituted benzene) may be, for example, 1,3,5-trisubstituted or 1,2,3-trisubstituted. Higher degrees of substitution, of which the pentafluorophenyl group is an example, exist and are named according to IUPAC nomenclature.
Etymology
Phenyl is derived , which in turn derived , as the first phenyl compounds named were byproducts of making and refining various gases used for lighting. According to McMurry, "The word is derived , commemorating the discovery of benzene by Michael Faraday in 1825 from the oily residue left by the illuminating gas used in London street lamps."
Structure, bonding, and characterization
Phenyl compounds are derived from benzene (), at least conceptually and often in terms of their production. In terms of its electronic properties, the phenyl group is related to a vinyl group. It is generally considered an inductively withdrawing group (-I), because of the higher electronegativity of sp2 carbon atoms, and a resonance donating group (+M), due to the ability of its π system to donate electron density when conjugation is possible. The phenyl group is hydrophobic. Phenyl groups tend to resist oxidation and reduction. Phenyl groups (like all aromatic compounds) have enhanced stability in comparison to equivalent bonding in aliphatic (non-aromatic) groups. This increased stability is due to the unique properties of aromatic molecular orbitals.
The bond lengths between carbon atoms in a phenyl group are approximately 1.4 Å.
In 1H-NMR spectroscopy, protons of a phenyl group typically have chemical shifts around 7.27 ppm. These chemical shifts are influenced by aromatic ring current and may change depending on substituents.
Preparation, occurrence, and applications
Phenyl groups are usually introduced using reagents that behave as sources of the phenyl anion or the phenyl cation. Representative reagents include phenyllithium () and phenylmagnesium bromide (). Electrophiles are attacked by benzene to give phenyl derivatives:
C6H6 + E+ -> C6H5E + H+
where (the "electrophile") = . These reactions are called electrophilic aromatic substitutions.
Phenyl groups are found in many organic compounds, both natural and synthetic (see figure). Most common among natural products is the amino acid phenylalanine, which contains a phenyl group. A major product of the petrochemical industry is "BTX" consisting of benzene, toluene, and xylene - all of which are building blocks for phenyl compounds. The polymer polystyrene is derived from a phenyl-containing monomer and owes its properties to the rigidity and hydrophobicity of the phenyl groups. Many drugs as well as many pollutants contain phenyl rings.
One of the simplest phenyl-containing compounds is phenol, . It is often said the resonance stability of phenol makes it a stronger acid than that of aliphatic alcohols such as ethanol (pKa = 10 vs. 16–18). However, a significant contribution is the greater electronegativity of the sp2 alpha carbon in phenol compared to the sp3 alpha carbon in aliphatic alcohols.
References
External links
Aryl groups | Phenyl group | Chemistry | 1,206 |
13,636,115 | https://en.wikipedia.org/wiki/Radical%20trust | Radical trust is the confidence that any structured organization, such as a government, library, business, religion, or museum, has in collaboration and empowerment within online communities. Specifically, it pertains to the use of blogs, wiki and online social networking platforms by organizations to cultivate relationships with an online community that then can provide feedback and direction for the organization's interest. The organization 'trusts' and uses that input in its management.
One of the first appearances of the notion of radical trust appears in an info graphic outlining the base principles of web 2.0 in Tim O'Reilly's weblog post "What is Web 2.0" . Radical Trust is listed as the guiding example of trusting the validity of consumer generated media.
This concept is considered to be an underlying assumption of Library 2.0. The adoption of radical trust by a library would require its management let go of some of its control over the library and building an organization without an end result in mind. (Harris, 2006). The direction a library would take would be based on input provided by people through online communities. These changes in the organization may merely be anecdotal in nature, making this method of organization management dramatically distinct from data-based or evidence based management.
In marketing, Collin Douma further describes the notion of radical trust in the article "Radical Trust" August 28, 2006 Marketing Magazine (Canada) as a key mindset required for marketers and advertisers to enter the social media marketing space. Conventional marketing dictates and maintains control of messages to cause the greatest persuasion in consumer decisions. Given the proliferation of peer-to-peer consumer reviews and other social media platforms that enable consumer generated media, marketing agencies can no longer control the skew of that information. Marketers who are creating and participating in online platforms to facilitate conversation are radically trusting the consumer to build the brand based on the experience that is most relevant to them.
References
O'Reilly, Tim. What is Web 2.0 . Design Patterns and Business Models for the Next Generation of Software, Sept 30, 2005. Wikipedia listed as primary example of radical trust.
Douma, Collin. Radical Trust. Marketing Magazine . August 28. 2006
Douma, Collin. What is Radical Trust? Oct 1, 2006
Chan, Sebastian and Jim Spadaccini. Radical Trust: The State of the Museum Blogosphere
Fichter, Darlene. Web 2.0, Library 2.0 and Radical Trust: A First Take. April 2, 2006.
Harris, Christopher. A Matter of (Radical) Trust. School Library Journal. New York: Nov 2006. Vol. 52, (11) pg. 24.
Kimberly Bolan, Meg Canada, Rob Cullin. Web, Library, and Teen Services 2.0. Young Adult Library Services. Chicago: Winter 2007. Vol. 5, Iss. 2; pg. 40-43.
Social media
Social networks
Web 2.0
Library 2.0 | Radical trust | Technology | 604 |
37,202,189 | https://en.wikipedia.org/wiki/Scleroderma%20polyrhizum | Scleroderma polyrhizum, commonly known as the star earthball or dead man's hand, is a basidiomycete fungus and a member of the genus Scleroderma, or "earthballs". Found in dry, sandy soils, this species begins completely buried before slowly forcing the soil aside as it cracks apart to form a rough, star-shaped body with a diameter of . At the center is the dark, brownish spore mass. Widely distributed wherever the soil and climate are favorable, it is known from Asia, Europe, and the Americas.
Taxonomy
The species was first described by Johann Friedrich Gmelin in 1792 as Lycoperdon polyrhizum. Christiaan Hendrik Persoon transferred the species to the genus Scleroderma in his 1801 work Synopsis methodica fungorum. Elias Fries's Scleroderma geaster (published in 1829) is a synonym; the epithet geaster refers to the similarity with earthstar fungi of the genus Geastrum. In 1848, Joseph-Henri Léveillé considered the star-shaped opening of mature fruit bodies to be a distinct characteristic and proposed the genus Sclerangium to contain the taxon.
According to the classification of Scleroderma proposed by Gastón Guzmán in 1970, Scleroderma polyrhizum is placed in the subgenus Sclerangium, which includes species with partially reticulate spores.
Common names that have been used for the fungus include: many-rooted earthball, earthstar scleroderma, star earthball, and dead man's hand.
Description
When unopened, the fruit body ranges in shape from round to flattened to somewhat irregular, sometimes with lobes. As the mushroom matures, the peridium (outer skin) opens in a star-like manner to form 4–8 rays that curl back and expose the inner spore mass (gleba). Typically, more than half of the fruit bodies remains buried in the ground, attached by white, string-like or flattened strands rhizomorphs. The peridium is tough and thick, typically , with a rough and cracked surface. It is initially white, then turns yellowish to light brown as it matures. When unopened, the fruit body is wide, expanding to after rupturing. In young specimens, the gleba is firm and light grey, but it becomes dark brown and powdery after the spores mature. The spores are spherical, partially reticulate with warts or spines, and measure 6–11 μm. A drop of dilute potassium hydroxide placed on the surface of the fruit body will either be nonreactive or turn the peridium slightly yellow.
The species contains toxins which, if ingested, cause serious gastric upset. It is also similar to other poisonous species.
Similar species
Scleroderma texense has a fruitbody similar in appearance to S. polyrhizum. Some authors have considered them synonymous, but Guzmán's 1970 study of the type showed that S. texense is distinct. It typically has an exoperidium that is more yellowish or orangish, with thick, folded scales in maturity. S. citrinum is also similar.
Habitat and distribution
Fruit bodies of Scleroderma polyrhizum grow singly, scattered, or in clusters, usually on hard clay or sandy soil, gravel, in lawns, or bare soil. Fruiting occurs in late summer and fall, although blackened rays can sometimes be found in the winter. It has a wide distribution in North America, including Mexico. It has also been recorded from Africa, Asia (China and Japan), Europe, South America (Brazil), and Oceania.
Although Scleroderma polyrhizum is probably a saprobic species, experimental evidence suggests that it is also mycorrhizal. When a slurry of spores was inoculated with seedlings of Monterey pine (Pinus radiata), the fungus grew ectomycorrhizae that were dichotomously branched and formed coral-like structures comprising more than 50 branches. These structures were 1–2 mm long and 0.4–0.6 mm in diameter.
The mushroom was featured on a Libyan postage stamp in 1985.
Chemistry
Scleroderma polyrhizum fruit bodies have been used in Traditional Chinese medicine in the treatment of treatment of detumescence and hemostasis. They contains the steroid compounds ergosta-4,6,8(14) 22-tetraen-3-one and 5α,8α-epidoxyergosta-6,22-dien-3β-ol as well as palmitic acid and oleic acid.
See also
List of Scleroderma species
References
External links
Fungi described in 1792
Fungi of Africa
Fungi of Asia
Fungi of Europe
Fungi of North America
Fungi of Oceania
Fungi of South America
Poisonous fungi
Puffballs
Fungi without expected TNC conservation status
Fungus species
Scleroderma | Scleroderma polyrhizum | Biology,Environmental_science | 1,027 |
4,189,435 | https://en.wikipedia.org/wiki/Dill%20oil | Dill oil is an essential oil extracted from the seeds or leaves/stems (dillweed) of the Dill plant. It can be used with water to create dill water. Dill (Anethum graveolens) is an annual herb in the celery family Apiaceae. It is the sole species of the genus Anethum.
Origin
Also known as Indian Dill, originally from Southwest Asia, Dill is an annual or biennial herb that grows up to 1 meter (3 feet). It has green feathery leaves and umbels of small yellow flowers, followed by tiny compressed seeds.
It was popular with the Egyptians, Greeks and Romans, who called it "Anethon" from which the botanical name was derived. The common name comes from the Anglo-Saxon dylle or dylla, which then changed to dill. The word means 'to lull' – referring to its soothing properties. In the Middle Ages it was used as a charm against witchcraft.
From 812 onwards, when Charlemagne, King of the Franks, Emperor of the Romans, ordered the extensive cultivation of this herb, it has been widely used, especially, as a culinary herb.
Properties
Dill oil is known for its grass-like smell and its pale yellow color, with a watery viscosity.
Production
Dill oil is extracted by steam distillation, mainly from the seeds, or the whole herb, fresh or partly dried.
References
Essential oils | Dill oil | Chemistry | 301 |
5,249,765 | https://en.wikipedia.org/wiki/Frey%20curve | In mathematics, a Frey curve or Frey–Hellegouarch curve is the elliptic curve
associated with an ABC triple . This relates properties of solutions of equations to elliptic curves. This curve was popularized in its application to Fermat’s Last Theorem where one investigates a (hypothetical) solution of Fermat's equation
The curve is named after Gerhard Frey and (sometimes) .
History
came up with the idea of associating solutions of Fermat's equation with a completely different mathematical object: an elliptic curve. If ℓ is an odd prime and a, b, and c are positive integers such that
then a corresponding Frey curve is an algebraic curve given by the equation
or, equivalently
This is a nonsingular algebraic curve of genus one defined over Q, and its projective completion is an elliptic curve over Q.
called attention to the unusual properties of the same curve as Hellegouarch, which became called a Frey curve. This provided a bridge between Fermat and Taniyama by showing that a counterexample to Fermat's Last Theorem would create such a curve that would not be modular. The conjecture attracted considerable interest when suggested that the Taniyama–Shimura–Weil conjecture implies Fermat's Last Theorem. However, his argument was not complete. In 1985, Jean-Pierre Serre proposed that a Frey curve could not be modular and provided a partial proof of this. This showed that a proof of the semistable case of the Taniyama–Shimura conjecture would imply Fermat's Last Theorem. Serre did not provide a complete proof and what was missing became known as the epsilon conjecture or ε-conjecture. In the summer of 1986, proved the epsilon conjecture, thereby proving that the Taniyama–Shimura–Weil conjecture implies Fermat's Last Theorem.
Notes
References
Number theory | Frey curve | Mathematics | 383 |
25,206,887 | https://en.wikipedia.org/wiki/Days%20in%20inventory | Days in inventory (also known as "Inventory Days of Supply", "Days Inventory Outstanding" or the "Inventory Period") is an efficiency ratio which measures the average number of days a company holds its inventory before selling it. The ratio measures the number of days funds are tied up in inventory. Inventory levels (measured at cost) are divided by sales per day (also measured at cost rather than selling price.)
The formula for days in inventory is:
, alternatively expressed as:
,
where DII is days in inventory and COGS is cost of goods sold. The average inventory is the average of inventory levels at the beginning and end of an accounting period, and COGS/day is calculated by dividing the total cost of goods sold per year by the number of days in the accounting period, generally 365 days.
This is equivalent to the 'average days to sell the inventory' which is calculated as:
See also
Inventory turnover, for a more complete discussion of issues related to the diagnosis of inventory effectiveness
Working capital analysis
Days sales outstanding
Days payable outstanding
Cash conversion cycle
References
Financial ratios
Working capital management | Days in inventory | Mathematics | 222 |
19,985,034 | https://en.wikipedia.org/wiki/SY%20control%20cable | An SY control cable is a flexible instrumentation electrical cable designed for measuring, control or regulation in the field of process automation. It is a flexible multicore cable, with (class 5) copper conductors and a galvanised steel wire braid (GSWB) for mechanical protection. The cable is typically manufactured with PVC insulation, bedding and a transparent PVC sheath. The transparent sheath means signs of deterioration, damage or corrosion can be detected with ease.
SY has a voltage rating of 300/500V.
SY cable should not be used on voltages above ELV in the UK as the braid does not meet BS 7671 for current carrying capacity under fault conditions.
Only cables mentioned in BS 7671 should be used unless the designer can show that the cable used meets the same standards. Although the combined cross sectional area of the braid may meet the adiabatic equation requirements for earthing, the nature of the braid being made of very fine strands coupled with the comparatively large gaps, when compared to SWA cable, means that under short circuit conditions the fine strands can melt and so the braid will no longer be in contact with a penetrating object such as a screw or nail
Some SY cables on the market are of poor standard, with cases of GSWB coverage being less than 20%. With no standard set, poor quality cables are available on the market at low procurement costs - but this cable's life will be substantially lower. A GSWB coverage of above 55% attains to acceptable standard SY.
Uses
SY control cables are not suitable for fixed wiring applications in the UK requiring compliance with the requirements set out in BS 7671.
SY cable should not be used in areas exposed to ultraviolet light as it damages the outer sheath leading to cracking and then rusting of the braid as water penetrates the damaged sheath.
Origin of the name SY
In CENELEC code – the European Committee for Electrotechnical Standardization – the S in SY stands for steel wire braid, and the Y for PVC. SY Control Cable can be referred to more generally as Instrumentation Cable, Flexible or Braided Control Cable and Control Flex.
CY and YY control cables
There are three different types of Control Cable in the area of process automation: CY, YY and SY Cable. With its GSWB braid SY is suited to installations with medium to high mechanical stress. YY and CY Control Cable are very similar in construction, but without the mechanical protection provided by the steel wire. YY is a versatile cable that works well in environments with only light mechanical stress and CY Cable has a tinned copper wire braid and polyester binder tape, which provide protection against external electromagnetic influences.
See also
Electrical cable
References
Industrial automation
Signal cables | SY control cable | Engineering | 552 |
40,675,011 | https://en.wikipedia.org/wiki/Neotripterifordin | Neotripterifordin is an anti-viral diterpene lactone isolated from Tripterygium wilfordii.
References
Antiviral drugs
Diterpenes
Lactones
Tertiary alcohols
Cyclopentanes
Heterocyclic compounds with 5 rings | Neotripterifordin | Chemistry,Biology | 57 |
69,980,370 | https://en.wikipedia.org/wiki/Amin%20Abbosh | Amin M. Abbosh is an Iraqi electrical engineer.
He earned a bachelor's degree in electrical engineering from the University of Mosul, then remained at the institution to complete his graduate study in the subject, obtaining his master's degree in 1991 and his doctorate in 1996. He is a professor at the University of Queensland. In 2022, Abbosh was elected a fellow of the IEEE, "for contributions to electromagnetic medical imaging."
References
Living people
Year of birth missing (living people)
Electrical engineers
Iraqi engineers
University of Mosul alumni
Academic staff of the University of Queensland
Fellows of the IEEE
21st-century engineers
20th-century engineers | Amin Abbosh | Engineering | 132 |
50,491,390 | https://en.wikipedia.org/wiki/Networked%20Help%20Desk | Networked Help Desk is an open standard initiative to provide a common API for sharing customer support tickets between separate instances of issue tracking, bug tracking, customer relationship management (CRM) and project management systems to improve customer service and reduce vendor lock-in. The initiative was created by Zendesk in June 2011 in collaboration with eight other founding member organizations including Atlassian, New Relic, OTRS, Pivotal Tracker, ServiceNow and SugarCRM. The first integration, between Zendesk and Atlassian's issue tracking product, Jira, was announced at the 2011 Atlassian Summit. By August 2011, 34 member companies had joined the initiative. A year after launching, over 50 organizations had joined. Within Zendesk instances this feature is branded as ticket sharing.
Basis
Support tools are generally built around a common paradigm that begins with a customer making a request or an incident report, these create a ticket. Each ticket has a progress status and is updated with annotations and attachments. These annotations and attachments may be visible to the customer (public), or only visible to analysts (private). Customers are notified of progress made on their ticket until it is complete. If the people necessary to complete a ticket are using separate support tools, additional overhead is introduced in maintaining the relevant information in the ticket in each tool while notifying the customer of progress made by each group in completing their ticket. For example, if a customer support issue is caused by a software bug and reported to a help desk using one system, and then the fix is documented by the developers in another, and analyzed in a customer relationship management tool, keeping the records in each system up-to-date and notifying the customer manually using a swivel chair approach is unnecessarily time-consuming and error-prone. If information is not transferred correctly, a customer may have to re-explain their problem each time their ticket is transferred.
For systems with the Networked Help Desk API implemented, it is possible for several different applications related to a customer's support experience to synchronize data in one uniquely identified shared ticket. While many applications in these domains have implemented APIs that allow data to be imported, exported and modified, Network Help Desk provide a common standard for customer support information to automatically synchronize between several systems. Once implemented, two systems can quickly share tickets with just a configuration change as they both understand the same interface.
Communication between two instances on a specific ticket occurs in three steps, an invitation agreement, sharing of ticket data and continued synchronization of tickets. The standard allows for "full delegation" (analysts in both systems each make public and private comments and synchronize status) as well as "partial delegation" where the instance receiving the ticket can only make private comments and status changes are not synchronized. Tickets may be shared with multiple instances.
Implementation list
See also
Comparison of issue-tracking systems
Enterprise application integration
Enterprise service bus
OSS through Java
Web-oriented architecture
References
Further reading
External links
Networked Help Desk on ProgrammableWeb
Cloud computing
Cloud standards
Open standards
Application programming interfaces | Networked Help Desk | Technology | 633 |
40,516,731 | https://en.wikipedia.org/wiki/IPhone%20accessories | The iPhone has a wide variety of accessories made by Apple available for it.
EarPods
Apple EarPods (introduced on September 12, 2012) first shipped with the iPhone 5 and feature a remote control and microphone. They also ship with the fifth-generation iPod touch (without mic) and the seventh-generation iPod nano (without mic). They're also sold independently. The Apple EarPods are assembled in Vietnam.
All but the basic earbuds have control capsules allowing users to adjust volume and control music and video playback, located on the cable of the right earpiece; those "with Remote and Mic" also include a microphone for phone calls and voice control of certain devices. Users can adjust volume, control music and video playback (play/pause and next/previous,) and record voice memos on supported iPod and iPhone models and Mac computers. There have been many reports of moisture problems with the remote/mic earbuds. The original iPhone and iPhone 3G came with the iPhone Stereo Headset, a push-button and microphone on the right side of the headphones (there is no volume control, and only limited control of calls).
Dock
A series of docks released for the iPhone 5, 5s, and 5c, were announced and released on September 10, 2013. The docks have an identical design, with an audio-out and Lightning-in port on the back, and a Lightning connector on the top. One dock was released solely for the iPhone 5 and 5s, with another dock optimized for the iPhone 5c. The dock is not compatible with iPhones in their cases.
Case
For the physical care of the cell phone it is advisable to use cases that cover the entire back of the cell phone. Currently there are many distributors that offer different alternatives in models, materials, colors and custom designs.
References
IPhone | IPhone accessories | Technology | 378 |
1,944,381 | https://en.wikipedia.org/wiki/Falling%20film%20evaporator | A falling film evaporator is an industrial device to concentrate solutions, especially with heat sensitive components. The evaporator is a special type of heat exchanger.
General
In general evaporation takes place inside vertical tubes, but there are also applications where the process fluid evaporates on the outside of horizontal or vertical tubes. In all cases, the process fluid to be evaporated flows downwards by gravity as a continuous film. The fluid will create a film along the tube walls, progressing downwards (falling) - hence the name.
The fluid distributor has to be designed carefully in order to maintain an even liquid distribution for all tubes along which the solution falls. A typical distributor is shown in Fig. 2; these distributors are usually called ferrules due to their concentric shape.
In the majority of applications the heating medium is placed on the outside of the tubes. High heat transfer coefficients are required in order to achieve equally balanced heat transfer resistances. Therefore, condensing steam is commonly used as a heating medium.
For internally evaporating fluids, separation between the liquid phase (the solution) and the gaseous phase takes place inside the tubes. In order to maintain conservation of mass as this process proceeds, the downward vapor velocity increases, increasing the shear force acting on the liquid film and therefore also the velocity of the solution. The result can be a high film velocity of a progressively thinner film resulting in increasingly turbulent flow. The combination of these effects allows very high heat transfer coefficients.
The heat transfer coefficient on the evaporating side of the tube is mostly determined by the hydrodynamic flow conditions of the film. For low mass flows or high viscosities the film flow can be laminar, in which case heat transfer is controlled purely by conduction through the film. Therefore in this condition the heat transfer coefficient decreases with increased mass flow. With increased mass flow the film becomes wavy laminar and then turbulent. Under turbulent conditions the heat transfer coefficient increases with increased flow.
Evaporation takes place at very low mean temperature differences between heating medium and process stream, typically between 3 - 6K, therefore these devices are ideal for heat recovery in multi stage processes.
A further advantage of the falling film evaporator is the very short residence time of the liquid and the absence of superheating of the same. Not considering the vapour separator, the residence time inside the tubes is measured in seconds, making it ideal for heat-sensitive products such as milk, fruit juice, pharmaceuticals, and many others.
Falling film evaporators are also characterised by very low pressure drops; therefore, they are often used in deep vacuum applications.
Fouling
Due to the intimate contact of the liquid with the heating surface, these evaporators are sensitive to fouling from precipitating solids. Low liquid velocity at the inlet is usually not sufficient to perform an effective self-cleaning of the tubes.
Falling film evaporators are therefore used in clean, non-precipitating liquids. A typical application, in chemical industry, is for concentration of caustic soda.
Falling film evaporators versus flooded evaporators
Falling film evaporators have a number of advantages over their flooded evaporator counterparts.
They require a lower charge, as the entire shell (in the case of horizontal evaporators) or all the tubes (in the case of a vertical evaporator) need not be filled with liquid as a thin film is now used to cover the surfaces. In industries such as heating and air-conditioning this can save significant money due to the high costs of a refrigerant charge.
Falling film evaporators also show improved heat transfer characteristics over their flooded counterparts, particularly in cases with low heat flux.
A number of disadvantages exist, primarily being the comparable lack of understanding of falling film evaporators compared to flooded evaporators, particularly for horizontal falling film evaporators. Furthermore the fluid distribution for horizontal falling film evaporators is a challenge, as the performance is severely limited if an uneven distribution of film over the tubes is created.
Horizontal versus vertical falling film evaporators
Horizontal falling film evaporators have a number of potential advantages over their vertical counterparts in the petrochemical industry, such as the ability to use tubes with external enhancements; while internally-enhanced tubes are available for vertical falling film evaporators, external enhancements are typically superior for boiling applications. The chief disadvantage of horizontal falling film evaporators is that if a corrosive or fouling liquid is to be evaporated, it will have to placed on the shell side. This is against best practice, as it is easier to clean fouling found on the inside of tubes rather than the outside.
See also
Climbing and falling film plate evaporator
References
External links
Falling Film Evaporators
Wolverine Tube Heat Transfer Databooks
Evaporators | Falling film evaporator | Chemistry,Engineering | 985 |
15,228,065 | https://en.wikipedia.org/wiki/TRIM16 | Tripartite motif-containing protein 16 is a protein that in humans is encoded by the TRIM16 gene.
This gene was identified as an estrogen and anti-estrogen regulated gene in epithelial cells stably expressing estrogen receptor. The protein encoded by this gene contains two B box domains and a coiled-coiled region that are characteristic of the B box zinc finger protein family.
The proteins of this family have been reported to be involved in a variety of biological processes including cell growth, differentiation and pathogenesis. Expression of this gene was detected in most tissues. Its function, however, has not yet been determined.
References
Further reading | TRIM16 | Chemistry | 130 |
70,807,222 | https://en.wikipedia.org/wiki/Sarah-Marie%20Belcastro | Sarah-Marie Belcastro (aka sarah-marie belcastro, born 1970) is an American mathematician and book author. She is an instructor at the Art of Problem Solving Online School and is the director of MathILy, a residential math summer program hosted at Bryn Mawr. Although her doctoral research was in algebraic geometry, she has also worked extensively in topological graph theory. She is known for and has written extensively about mathematical knitting, and has co-edited three books on fiber mathematics. She herself exclusively uses the form "sarah-marie belcastro".
Biography
Belcastro was born in San Diego, CA in 1970, and grew up mostly in Andover, MA, and in Dubuque, IA. She earned a B.S. (1991) in Mathematics and Astronomy from Haverford College, an M.S. (1993) from The University of Michigan, Ann Arbor, and a Ph.D. (1997) there for a thesis on “Picard Lattices of Families of K3 Surfaces” done with Igor Dolgachev.
Since 2012, she has also been an instructor at the Art of Problem Solving Online School. Since 2013, she has been the director of Bryn Mawr College's residential summer program MathILy (serious Mathematics Infused with Levity). She is also a guest faculty member at Sarah Lawrence College.
She was Associate Editor for The College Mathematics Journal (2003—2019). She has also lectured frequently at the University of Massachusetts, Amherst since 2012.
Selected publications
Books
Discrete Mathematics with Ducks (AK Peters, 2012; 2nd ed., CRC Press, 2019, ).
Figuring Fibers, edited by belcastro and Carolyn Yackel, Providence, RI: American Mathematics Society, 2018.
Crafting by Concepts: fiber arts and mathematics, edited by belcastro and Yackel. AK Peters, 2011.
Making Mathematics with Needlework: Ten Papers and Ten Projects, edited by belcastro and Yackel. Wellesley, MA: AK Peters, 2007.
Journal papers
References
External links
Official home page
American women mathematicians
Haverford College alumni
University of Michigan alumni
Geometric topology
American algebraists
Mathematics and art
21st-century American textile artists
American people in knitting
1970 births
Living people | Sarah-Marie Belcastro | Mathematics | 451 |
45,436,992 | https://en.wikipedia.org/wiki/CMF%20design | Color, Materials, Finish (CMF) is an area of industrial design that focuses on the chromatic, tactile and decorative identity of products and environments.
Characteristics
CMF design uses metadesign logic, the simultaneous planning of the identity of entire ranges of products for a given brand. This makes it possible, for example, to adopt a single color matrix, instead of using a series of separate and different color cards for each line of products, as previously done. A contribution to the development of this approach to design was the impetus provided by the proliferation in the 1980s of complete ranges of new systemic products.
Brand products are often thought up by different designers who through the use of ad-hoc CMF design manuals can work together to ensure a unique but coordinated identity for the products. This working process is advantageous in terms of the choice of color base for systemic products that are either of heterogeneous origin or are considered OEM products. The latter, even if characterized by different forms, can be connoted with the base colors or materials that are representative of the brand due to CMF design. Since CMF design manuals and the color matrix have a prescriptive role, the designers who create them are rarely involved in the applicative distribution either of colors, materials or finishes of individual products.
Bibliography
References
Industrial design | CMF design | Engineering | 273 |
68,847,122 | https://en.wikipedia.org/wiki/Atogepant | Atogepant, sold under the brand name Qulipta among others, is a medication used to prevent migraines. It is a gepant, an orally active calcitonin gene-related peptide receptor antagonist.
The most common side effects include nausea, constipation, tiredness, somnolence (sleepiness), decreased appetite, and decreased weight.
Atogepant was approved for medical use in the United States in September 2021, and in the European Union in August 2023.
Medical Uses
Atogepant is indicated for the preventive treatment of episodic migraine in adults.
In the European Union, atogepant (Aquipta) is indicated for prophylaxis (prevention) of migraine in adults who have at least four migraine days per month.
History
Atogepant was developed by the biopharmaceutical company AbbVie. The benefits and side effects of atogepant were evaluated in two clinical trials of 1,562 participants with a history of migraine headaches occurring on 4 to 14 days per month. The two trials to show the benefits were designed similarly. Trials 1 and 2 assigned participants to one of several doses of atogepant or placebo daily for three months. Neither the participants nor the health care providers knew which treatment was being given until after the trial was completed. The benefit of atogepant was assessed based on the change from baseline in the number of migraine days per month to the last month of the three-month treatment period, comparing participants in the atogepant and placebo groups. The trials were conducted at over 100 sites in the United States. The safety of atogepant was evaluated in 1,958 participants with migraine who received at least one dose of atogepant; therefore, the number of participants representing efficacy findings may differ from the number of participants representing safety findings due to different pools of study participants analyzed for efficacy and safety.
The UK’s National Institute for Health and Care Excellence has issued draft guidance recommending atogepant for preventing episodic and chronic migraine in NHS patients. It's approved for those experiencing at least 4 migraine days per month after failing 3 prior treatments. Atogepant costs £463 monthly but includes a confidential discount.
Research
Atogepant demonstrated efficacy in two phase 3 trials (ADVANCE and PROGRESS) by significantly reducing monthly migraine days, acute medication use, and improving quality of life in patients with episodic and chronic migraine over 12 weeks compared to placebo. Common side effects included nausea, constipation, and fatigue/somnolence.
A study presented at the 2023 meeting for the American Academy of Neurology also showed that atogepant may help prevent migraines in patients who have had no prior success with other preventative drugs.
References
Drugs developed by AbbVie
Antimigraine drugs
Calcitonin gene-related peptide receptor antagonists
Carboxamides
Organofluorides
Piperidines
Pyridines
Pyrroles
Spiro compounds | Atogepant | Chemistry | 640 |
20,899,899 | https://en.wikipedia.org/wiki/Faten%20Zahran%20Mohammed | Faten Zahran Mohammed (; born October 11, 1955, in Cairo) is an Egyptian biochemist and environmental biologist, cancer biologist and toxicologist known for her work on the anti-tumoral effects of snake venom and iodoacetate. She is currently Professor of Biochemistry at Zagazig University, Egypt, head of the Biochemistry Division, Faculty of Science, and a member of Egyptian Universities Promotion Committees "EUPC".
Biography
She worked as a Demonstrator of Biochemistry in Chemistry Department, Faculty of Science, Zagazig University, Egypt from 1977 to 1981. She served as Assistant Lecturer of Biochemistry, in the Faculty of Science, Zagazig University, Egypt from 1981 to 1985. Lecturer of Biochemistry, Chemistry Department, Faculty of Science, Zagazig University, Egypt from 1985 to 1991. She was Assistant Professor of Biochemistry, Chemistry Department, Faculty of Science, Zagazig University, Egypt from 1991 to 1996. Professor of Biochemistry, Chemistry Department, Faculty of Science, Zagazig University, Egypt from 1996 until present (2008).
She received her B.Sc. in 1977, her M.Sc. in biochemistry in 1981, and her Ph.D. in biochemistry in 1985 from Faculty of Science, Ain Shams University.
She received her M.Sc. and Ph.D. under the supervision of Dr. Fawzia Abbas Fahim.
Selected publications
Fahim FA., Zahran F., Mady EA. "Effect of N. nigricollis venom and its fraction on EAC in mice." In: INTERNATIONAL CONFERENCE OF THE EGYPTIAN SOCIETY OF TUMOR MARKERS ONCOLOGY, 1, Cairo, 1988. Abstracts...Cairo: Ain Shams University- Faculty of Medicine, 1988. 375-94.
Mohamed AH, Fouad S, El-Aasar S, Salem AM, Abdel-Aal A, Hassan AA, Zahran F, Abbas N. "Effects of several snake venoms on serum and tissue transaminases, alkaline phosphatase and lactate dehydrogenase." Toxicon. 1981;19(5):605-9
References
Personal Interviews, November and December 2008.
1955 births
Living people
Scientists from Cairo
Zagazig University alumni
Ain Shams University alumni
Academic staff of Zagazig University
Egyptian women scientists
Women biochemists
Egyptian biologists | Faten Zahran Mohammed | Chemistry | 490 |
5,068,912 | https://en.wikipedia.org/wiki/HR%204177 | HR 4177, also called t2 Carinae (t2 Car), is a double star in the southern constellation of Carina. It is faintly visible to the naked eye with a combined apparent visual magnitude of +4.77. The two components are HD 92397 and HD 92398. The primary component is located at a distance of approximately 1,600 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +11 km/s. It has a peculiar velocity of and may be a runaway star. The star is a member of the BH 99 cluster.
The magnitude 4.85 primary, component A, is a massive K-type supergiant or bright giant with a stellar classification of K4.5Ib-II. Houk (1978) instead listed it with a class of K4/5III: but with some uncertainty about the classification. It has 12 times the mass of the Sun and has expanded to 202 times the Sun's radius. The star is radiating 8,478 times the luminosity of the Sun from its bloated photosphere at an effective temperature of 3,900 K.
The magnitude 7.48 companion star, component B, was discovered by J. Dunlop in 1829. As of 2015, it was located at an angular separation of along a position angle of 21°, relative to the primary. It is a B-type giant/bright giant star with a class of B9II/III. The pair show a common proper motion and roughly similar parallax measurements, but it remains unclear whether they form a gravitationally-bound pair.
References
Double stars
K-type supergiants
B-type bright giants
Carina (constellation)
Carinae, t2
Durchmusterung objects
092397
052102
4177 | HR 4177 | Astronomy | 380 |
13,998,668 | https://en.wikipedia.org/wiki/Cancer%20immunology | Cancer immunology (immuno-oncology) is an interdisciplinary branch of biology and a sub-discipline of immunology that is concerned with understanding the role of the immune system in the progression and development of cancer; the most well known application is cancer immunotherapy, which utilises the immune system as a treatment for cancer. Cancer immunosurveillance and immunoediting are based on protection against development of tumors in animal systems and (ii) identification of targets for immune recognition of human cancer.
Definition
Cancer immunology is an interdisciplinary branch of biology concerned with the role of the immune system in the progression and development of cancer; the most well known application is cancer immunotherapy, where the immune system is used to treat cancer. Cancer immunosurveillance is a theory formulated in 1957 by Burnet and Thomas, who proposed that lymphocytes act as sentinels in recognizing and eliminating continuously arising, nascent transformed cells. Cancer immunosurveillance appears to be an important host protection process that decreases cancer rates through inhibition of carcinogenesis and maintaining of regular cellular homeostasis. It has also been suggested that immunosurveillance primarily functions as a component of a more general process of cancer immunoediting.
Tumor antigens
Tumors may express tumor antigens that are recognized by the immune system and may induce an immune response. These tumor antigens are either TSA (Tumor-specific antigen) or TAA (Tumor-associated antigen).
Tumor-specific
Tumor-specific antigens (TSA) are antigens that only occur in tumor cells. TSAs can be products of oncoviruses like E6 and E7 proteins of human papillomavirus, occurring in cervical carcinoma, or EBNA-1 protein of EBV, occurring in Burkitt's lymphoma cells. Another example of TSAs are abnormal products of mutated oncogenes (e.g. Ras protein) and anti-oncogenes (e.g. p53).
Tumor-associated antigens
Tumor-associated antigens (TAA) are present in healthy cells, but for some reason they also occur in tumor cells. However, they differ in quantity, place or time period of expression. Oncofetal antigens are tumor-associated antigens expressed by embryonic cells and by tumors. Examples of oncofetal antigens are AFP (α-fetoprotein), produced by hepatocellular carcinoma, or CEA (carcinoembryonic antigen), occurring in ovarian and colon cancer. More tumor-associated antigens are HER2/neu, EGFR or MAGE-1.
Immunoediting
Cancer immunoediting is a process in which immune system interacts with tumor cells. It consists of three phases: elimination, equilibrium and escape. These phases are often referred to as "the three Es" of cancer immunoediting. Both adaptive and innate immune system participate in immunoediting.
In the elimination phase, the immune response leads to destruction of tumor cells and therefore to tumor suppression. However, some tumor cells may gain more mutations, change their characteristics and evade the immune system. These cells might enter the equilibrium phase, in which the immune system does not recognise all tumor cells, but at the same time the tumor does not grow. This condition may lead to the phase of escape, in which the tumor gains dominance over immune system, starts growing and establishes immunosuppressive environment.
As a consequence of immunoediting, tumor cell clones less responsive to the immune system gain dominance in the tumor through time, as the recognized cells are eliminated. This process may be considered akin to Darwinian evolution, where cells containing pro-oncogenic or immunosuppressive mutations survive to pass on their mutations to daughter cells, which may themselves mutate and undergo further selective pressure. This results in the tumor consisting of cells with decreased immunogenicity and can hardly be eliminated. This phenomenon was proven to happen as a result of immunotherapies of cancer patients.
Tumor evasion mechanisms
CD8+ cytotoxic T cells are a fundamental element of anti-tumor immunity. Their TCR receptors recognise antigens presented by MHC class I and when bound, the Tc cell triggers its cytotoxic activity. MHC I are present on the surface of all nucleated cells. However, some cancer cells lower their MHC I expression and avoid being detected by the cytotoxic T cells. This can be done by mutation of MHC I gene or by lowering the sensitivity to IFN-γ (which influences the surface expression of MHC I). Tumor cells also have defects in antigen presentation pathway, what leads into down-regulation of tumor antigen presentations. Defects are for example in transporter associated with antigen processing (TAP) or tapasin. On the other hand, a complete loss of MHC I is a trigger for NK cells. Tumor cells therefore maintain a low expression of MHC I.
Another way to escape cytotoxic T cells is to stop expressing molecules essential for co-stimulation of cytotoxic T cells, such as CD80 or CD86.
Tumor cells express molecules to induce apoptosis or to inhibit T lymphocytes:
Expression of FasL on its surface, tumor cells may induce apoptosis of T lymphocytes by FasL-Fas interaction.
Expression of PD-L1 on the surface of tumor cells leads to suppression of T lymphocytes by PD1-PD-L1 interaction.
Tumor cells have gained resistance to effector mechanisms of NK and cytotoxic CD8+ T cell:
by loss of gene expression or inhibition of apoptotic signal pathway molecules: APAF1, Caspase 8, Bcl-2-associated X protein (bax) and Bcl-2 homologous antagonist killer (bak).
by induction of expression or overexpression of antiapoptotic molecules: Bcl-2, IAP or XIAP.
Tumor microenvironment
Production of TGF-β by tumor cells and other cells (such as myeloid-derived suppressor cell) leads to conversion of CD4+ T cell into suppressive regulatory T cell (Treg) by a contact dependent or independent stimulation. In a healthy tissue, functioning Tregs are essential to maintain self-tolerance. In a tumor, however, Tregs form an immunosuppressive microenvironment.
Tumor cells produce special cytokines (such as colony-stimulating factor) to produce myeloid-derived suppressor cell. These cells are heterogenous collection of cell types including precursors of dendritic cell, monocyte and neutrophil. MDSC have suppressive effects on T-lymphocytes, dendritic cells and macrophages. They produce immunosuppressive TGF-β and IL-10.
Another producer of suppressive TGF-β and IL-10 are tumor-associated macrophages, these macrophages have mostly phenotype of alternatively activated M2 macrophages. Their activation is promoted by TH type 2 cytokines (such as IL-4 and IL-13). Their main effects are immunosuppression, promotion of tumor growth and angiogenesis.
Tumor cells have non-classical MHC class I on their surface, for example HLA-G. HLA-G is inducer of Treg, MDSC, polarise macrophages into alternatively activated M2 and has other immunosuppressive effects on immune cells.
Immunomodulation methods
Immune system is the key player in fighting cancer. As described above in mechanisms of tumor evasion, the tumor cells are modulating the immune response in their profit. It is possible to improve the immune response in order to boost the immunity against tumor cells.
monoclonal anti-CTLA4 and anti-PD-1 antibodies are called immune checkpoint inhibitors:
CTLA-4 is a receptor upregulated on the membrane of activated T lymphocytes, CTLA-4 CD80/86 interaction leads to switch off of T lymphocytes. By blocking this interaction with monoclonal anti CTLA-4 antibody we can increase the immune response. An example of approved drug is ipilimumab.
PD-1 is also an upregulated receptor on the surface of T lymphocytes after activation. Interaction PD-1 with PD-L1 leads to switching off or apoptosis. PD-L1 are molecules which can be produced by tumor cells. The monoclonal anti-PD-1 antibody is blocking this interaction thus leading to improvement of immune response in CD8+ T lymphocytes. An example of approved cancer drug is nivolumab.
Chimeric Antigen Receptor T cell
This CAR receptors are genetically engineered receptors with extracellular tumor specific binding sites and intracellular signalling domain that enables the T lymphocyte activation.
Cancer vaccine
Vaccine can be composed of killed tumor cells, recombinant tumor antigens, or dendritic cells incubated with tumor antigens (dendritic cell-based cancer vaccine)
Relationship to chemotherapy
Obeid et al. investigated how inducing immunogenic cancer cell death ought to become a priority of cancer chemotherapy. He reasoned, the immune system would be able to play a factor via a 'bystander effect' in eradicating chemotherapy-resistant cancer cells. However, extensive research is still needed on how the immune response is triggered against dying tumour cells.
Professionals in the field have hypothesized that 'apoptotic cell death is poorly immunogenic whereas necrotic cell death is truly immunogenic'. This is perhaps because cancer cells being eradicated via a necrotic cell death pathway induce an immune response by triggering dendritic cells to mature, due to inflammatory response stimulation. On the other hand, apoptosis is connected to slight alterations within the plasma membrane causing the dying cells to be attractive to phagocytic cells. However, numerous animal studies have shown the superiority of vaccination with apoptotic cells, compared to necrotic cells, in eliciting anti-tumor immune responses.
Thus Obeid et al. propose that the way in which cancer cells die during chemotherapy is vital. Anthracyclins produce a beneficial immunogenic environment. The researchers report that when killing cancer cells with this agent uptake and presentation by antigen presenting dendritic cells is encouraged, thus allowing a T-cell response which can shrink tumours. Therefore, activating tumour-killing T-cells is crucial for immunotherapy success.
However, advanced cancer patients with immunosuppression have left researchers in a dilemma as to how to activate their T-cells. The way the host dendritic cells react and uptake tumour antigens to present to CD4+ and CD8+ T-cells is the key to success of the treatment.
See also
Oncogenomics
References
Oncology
Branches of immunology | Cancer immunology | Biology | 2,318 |
24,257,124 | https://en.wikipedia.org/wiki/Randi%C4%87%27s%20molecular%20connectivity%20index | The Randić index, also known as the connectivity index, of a graph is the sum of bond contributions where and are
the degrees of the vertices making bond i ~ j.
History
This graph invariant was introduced by Milan Randić in 1975. It is often used in chemoinformatics for investigations of organic compounds.
Notes
References
Roberto Todeschini, Viviana Consonni (2009) "Molecular Descriptors for Chemoinformatics", Wiley-VCH,
.
Graph invariants
Mathematical chemistry
Cheminformatics
de:Randić-Index | Randić's molecular connectivity index | Chemistry,Mathematics | 116 |
160,663 | https://en.wikipedia.org/wiki/Cantilever | A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilever can be formed as a beam, plate, truss, or slab.
When subjected to a structural load at its far, unsupported end, the cantilever carries the load to the support where it applies a shear stress and a bending moment.
Cantilever construction allows overhanging structures without additional support.
In bridges, towers, and buildings
Cantilevers are widely found in construction, notably in cantilever bridges and balconies (see corbel). In cantilever bridges, the cantilevers are usually built as pairs, with each cantilever used to support one end of a central section. The Forth Bridge in Scotland is an example of a cantilever truss bridge. A cantilever in a traditionally timber framed building is called a jetty or forebay. In the southern United States, a historic barn type is the cantilever barn of log construction.
Temporary cantilevers are often used in construction.
The partially constructed structure creates a cantilever, but the completed structure does not act as a cantilever.
This is very helpful when temporary supports, or falsework, cannot be used to support the structure while it is being built (e.g., over a busy roadway or river, or in a deep valley). Therefore, some truss arch bridges (see Navajo Bridge) are built from each side as cantilevers until the spans reach each other and are then jacked apart to stress them in compression before finally joining. Nearly all cable-stayed bridges are built using cantilevers as this is one of their chief advantages. Many box girder bridges are built segmentally, or in short pieces. This type of construction lends itself well to balanced cantilever construction where the bridge is built in both directions from a single support.
These structures rely heavily on torque and rotational equilibrium for their stability.
In an architectural application, Frank Lloyd Wright's Fallingwater used cantilevers to project large balconies.
The East Stand at Elland Road Stadium in Leeds was, when completed, the largest cantilever stand in the world holding 17,000 spectators.
The roof built over the stands at Old Trafford uses a cantilever so that no supports will block views of the field.
The old (now demolished) Miami Stadium had a similar roof over the spectator area. The largest cantilevered roof in Europe is located at St James' Park in Newcastle-Upon-Tyne, the home stadium of Newcastle United F.C.
Less obvious examples of cantilevers are free-standing (vertical) radio towers without guy-wires, and chimneys, which resist being blown over by the wind through cantilever action at their base.
Aircraft
The cantilever is commonly used in the wings of fixed-wing aircraft. Early aircraft had light structures which were braced with wires and struts. However, these introduced aerodynamic drag which limited performance. While it is heavier, the cantilever avoids this issue and allows the plane to fly faster.
Hugo Junkers pioneered the cantilever wing in 1915. Only a dozen years after the Wright Brothers' initial flights, Junkers endeavored to eliminate virtually all major external bracing members in order to decrease airframe drag in flight. The result of this endeavor was the Junkers J 1 pioneering all-metal monoplane of late 1915, designed from the start with all-metal cantilever wing panels. About a year after the initial success of the Junkers J 1, Reinhold Platz of Fokker also achieved success with a cantilever-winged sesquiplane built instead with wooden materials, the Fokker V.1.
In the cantilever wing, one or more strong beams, called spars, run along the span of the wing. The end fixed rigidly to the central fuselage is known as the root and the far end as the tip. In flight, the wings generate lift and the spars carry this load through to the fuselage.
To resist horizontal shear stress from either drag or engine thrust, the wing must also form a stiff cantilever in the horizontal plane. A single-spar design will usually be fitted with a second smaller drag-spar nearer the trailing edge, braced to the main spar via additional internal members or a stressed skin. The wing must also resist twisting forces, achieved by cross-bracing or otherwise stiffening the main structure.
Cantilever wings require much stronger and heavier spars than would otherwise be needed in a wire-braced design. However, as the speed of the aircraft increases, the drag of the bracing increases sharply, while the wing structure must be strengthened, typically by increasing the strength of the spars and the thickness of the skinning. At speeds of around the drag of the bracing becomes excessive and the wing strong enough to be made a cantilever without excess weight penalty. Increases in engine power through the late 1920s and early 1930s raised speeds through this zone and by the late 1930s cantilever wings had almost wholly superseded braced ones. Other changes such as enclosed cockpits, retractable undercarriage, landing flaps and stressed-skin construction furthered the design revolution, with the pivotal moment widely acknowledged to be the MacRobertson England-Australia air race of 1934, which was won by a de Havilland DH.88 Comet.
Currently, cantilever wings are almost universal with bracing only being used for some slower aircraft where a lighter weight is prioritized over speed, such as in the ultralight class.
Cantilever in microelectromechanical systems
Cantilevered beams are the most ubiquitous structures in the field of microelectromechanical systems (MEMS). An early example of a MEMS cantilever is the Resonistor, an electromechanical monolithic resonator. MEMS cantilevers are commonly fabricated from silicon (Si), silicon nitride (Si3N4), or polymers.
The fabrication process typically involves undercutting the cantilever structure to release it, often with an anisotropic wet or dry etching technique. Without cantilever transducers, atomic force microscopy would not be possible.
A large number of research groups are attempting to develop cantilever arrays as biosensors for medical diagnostic applications. MEMS cantilevers are also finding application as radio frequency filters and resonators.
The MEMS cantilevers are commonly made as unimorphs or bimorphs.
Two equations are key to understanding the behavior of MEMS cantilevers.
The first is Stoney's formula, which relates cantilever end deflection δ to applied stress σ:
where is Poisson's ratio, is Young's modulus, is the beam length and is the cantilever thickness. Very sensitive optical and capacitive methods have been developed to measure changes in the static deflection of cantilever beams used in dc-coupled sensors.
The second is the formula relating the cantilever spring constant to the cantilever dimensions and material constants:
where is force and is the cantilever width. The spring constant is related to the cantilever resonance frequency by the usual harmonic oscillator formula . A change in the force applied to a cantilever can shift the resonance frequency.
The frequency shift can be measured with exquisite accuracy using heterodyne techniques and is the basis of ac-coupled cantilever sensors.
The principal advantage of MEMS cantilevers is their cheapness and ease of fabrication in large arrays.
The challenge for their practical application lies in the square and cubic dependences of cantilever performance specifications on dimensions.
These superlinear dependences mean that cantilevers are quite sensitive to variation in process parameters, particularly the thickness as this is generally difficult to accurately measure. However, it has been shown that microcantilever thicknesses can be precisely measured and that this variation can be quantified. Controlling residual stress can also be difficult.
Chemical sensor applications
A chemical sensor can be obtained by coating a recognition receptor layer over the upper side of a microcantilever beam. A typical application is the immunosensor based on an antibody layer that interacts selectively with a particular immunogen and reports about its content in a specimen. In the static mode of operation, the sensor response is represented by the beam bending with respect to a reference microcantilever. Alternatively, microcantilever sensors can be operated in the dynamic mode. In this case, the beam vibrates at its resonance frequency and a variation in this parameter indicates the concentration of the analyte. Recently, microcantilevers have been fabricated that are porous, allowing for a much larger surface area for analyte to bind to, increasing sensitivity by raising the ratio of the analyte mass to the device mass. Surface stress on microcantilever, due to receptor-target binding, which produces cantilever deflection can be analyzed using optical methods like laser interferometry. Zhao et al., also showed that by changing the attachment protocol of the receptor on the microcantilever surface, the sensitivity can be further improved when the surface stress generated on the microcantilever is taken as the sensor signal.
See also
Applied mechanics
Cantilever bicycle brakes
Cantilever bicycle frame
Cantilever chair
Cantilever method
Cantilevered stairs
Corbel arch
Euler–Bernoulli beam theory
Grand Canyon Skywalk
Knudsen force in the context of microcantilevers
Orthodontics
Statics
References
Sources
Inglis, Simon: Football Grounds of Britain. CollinsWillow, 1996. page 206.
External links
Architectural elements
Structural system
Bridge components | Cantilever | Technology,Engineering | 2,024 |
18,690,388 | https://en.wikipedia.org/wiki/Cutoff%20voltage | In electronics,the cut-off voltage is the voltage at which a battery is considered fully discharged, beyond which further discharge could cause harm. Some electronic devices, such as cell phones, will automatically shut down when the cut-off voltage has been reached.
Batteries
In batteries, the cut-off (final) voltage is the prescribed lower-limit voltage at which battery discharge is considered complete. The cut-off voltage is usually chosen so that the maximum useful capacity of the battery is achieved. The cut-off voltage is different from one battery to the other and it is highly dependent on the type of battery and the kind of service in which the battery is used. When testing the capacity of a NiMH or NiCd battery a cut-off voltage of 1.0 V per cell is normally used, whereas 0.9 V is normally used as the cut-off voltage of an alkaline cell. Devices that have too high cut-off voltages may stop operating while the battery still has significant capacity remaining.
Voltage cut-off in portable electronics
Some portable equipment does not fully utilise the low-end voltage spectrum of a battery. The power to the equipment cuts off before a relatively large portion of the battery life has been used.
A high cut-off voltage is more widespread than perhaps assumed. For example, a certain brand of mobile phone that is powered with a single-cell Lithium-ion battery cuts off at 3.3 V. The Li‑ion can be discharged to 3 V and lower; however, with a discharge to 3.3 V (at room temperature), about 92–98% of the capacity is used. Importantly, particularly in the case of lithium-ion batteries, which are used in the vast majority of portable electronics today, a voltage cut-off below 3.2 V can lead to chemical instability in the cell, with the result being a reduced battery lifetime. For this reason, electronics manufacturers tend to use higher cut-off voltages, removing the need for consumers to buy battery replacements before other failure mechanisms in a device take effect .
See also
Cut-off (electronics)
- includes cutoff voltages for various battery chemistries
References
External links
Samples of Low Voltage Cut-Off Relay Circuits
Effect of discharge cut off voltage on cycle life of MgNi-based electrode for rechargeable Ni-MH batteries
Electrical parameters | Cutoff voltage | Engineering | 480 |
293,065 | https://en.wikipedia.org/wiki/Desiccant | A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccants for specialized purposes may be in forms other than solid, and may work through other principles, such as chemical bonding of water molecules. They are commonly encountered in foods to retain crispness. Industrially, desiccants are widely used to control the level of water in gas streams.
Types of desiccants
Although some desiccants are chemically inert, others are extremely reactive and require specialized handling techniques. The most common desiccant is silica gel, an otherwise inert, nontoxic, water-insoluble white solid. Tens of thousands of tons are produced annually for this purpose. Other common desiccants include activated charcoal, calcium sulfate, calcium chloride, and molecular sieves (typically, zeolites). Desiccants may also be categorized by their type, either I, II, III, IV, or V. These types are a function of the shape of the desiccant's moisture sorption isotherm.
Alcohols and acetones are also dehydrating agents. Diethylene glycol is an important industrial desiccant. It absorbs water from natural gas, minimizing the formation of methane hydrates, which can block pipes.
Performance efficiency
One measure of desiccant efficiency is the ratio (or percentage) of water storable in the desiccant relative to the mass of desiccant. Another measure is the residual relative humidity of the air or other fluid being dried. For drying gases, a desiccant's performance can be precisely described by the dew point of the dried product.
Colored saturation indicators
Sometimes a humidity indicator is included in the desiccant to show, by color changes, the degree of water-saturation of the desiccant. One commonly used indicator is cobalt chloride (), which is blue when anhydrous, but turns purple upon bonding with two water molecules (·2). Further hydration results in the pink hexaaquacobalt(II) chloride complex . However, the use of cobalt chloride raises health concerns, being potentially carcinogenic.
Applications
Applications of desiccants are dominated by the petrochemical industry. Hydrocarbons, including natural gas, often must be anhydrous or nearly so for processing or for transport. Catalysts that are used to convert some petroleum fractions are generally deactivated by even traces of water. Natural gas tends to form solid methane hydrates which can block pipes.
Domestic uses
One example of desiccant usage is in the manufacture of insulated windows where zeolite spheroids fill a rectangular spacer tube at the perimeter of the panes of glass. The desiccant helps to prevent the condensation of moisture between the panes. Another use of zeolites is in the "dryer" component of refrigeration systems to absorb water carried by the refrigerant, whether residual water left over from the construction of the system, or water released by the degradation of other materials over time.
Bagged desiccants are also commonly used to protect goods in barrier-sealed shipping containers against moisture damage: rust, corrosion, etc. Hygroscopic cargo, such as cocoa, coffee, various nuts and grains, and other foods can be particularly susceptible to mold and rot when exposed to condensation and humidity. Because of this, shippers often take measures by deploying desiccants to protect against loss. Pharmaceutical packaging often includes small packets of desiccant to keep the atmosphere inside the package below critical levels of water vapor.
Air conditioning systems can be based on desiccants, as drier air feels more comfortable and absorbing water itself removes heat.
Desiccants are used in livestock farming, where, for example, new-born piglets are highly susceptible to hypothermia owing to their wetness.
Laboratory uses
Desiccants are also used to remove water from solvents. Drying generally involves mixing the solvent with the solid desiccant. Molecular sieves are superior as desiccants relative to chemical drying reagents such as sodium-benzophenone. Sieves offer the advantages of being safe in air and recyclable.
See also
Desiccator
Humidity buffering
Humidity indicator card
Moisture sorption isotherm
Solar air conditioning
Oxygen scavenger (oxygen absorber)
Sorbent
Volatile corrosion inhibitor
Cromer cycle
References
Further reading
Packaging | Desiccant | Physics | 988 |
4,352,018 | https://en.wikipedia.org/wiki/Unit%208604 | Unit Nami 8604 (), officially the South China Epidemic Prevention and Water Purification Department (), was a disease research unit under the South China Area Army of the Imperial Japanese Army. This unit extensively and secretly researched biological warfare and other subjects through human experimentation during the Second Sino-Japanese War from 1938 to 1945.
History
Founded in Osaka, Japan in September 1938 as the Epidemic Prevention Department of the Twenty-First Army, this unit landed in Daya Bay with the Twenty-First Army in early October of 1938. It entered Guangzhou in late October and took the campus of the National Sun Yat-sen University School of Medicine as its headquarters. The unit took its names of Unit Nami 8604 and the South China Epidemic Prevention and Water Purification Department in April 1939. The unit was disbanded in August 1945 after the Japanese surrender.
Organisation
The headquarters of Unit 8604 had a General Affairs Division, responsible for logistics, personnel and financial management. The First Section was responsible for bacteriological research and consisted of the General Affairs Section, the Research Section, the Inspection Section, the Media Section, the Sterilisation Section, and the Animal Section, with a total of about 80 men, including 10 general and colonel officers and 7 Chinese labourers. The second class was engaged in research on epidemic prevention and water supply. The third class was responsible for research on the treatment of various infectious diseases. The fourth class was engaged in plague bacteria cultivation and anatomy. The class was located in a basement surrounded by barbed wire, isolated from the outside world, and everything was carried out inside. In the basement of the fourth class's building, many formalin-soaked corpses were stored, and the chief of the section performed autopsies every day. The fifth section was the equipment supply department
According to the colophon of the unit's name book, in addition to the Guangzhou Headquarters, branches were set up in various parts of Guangdong, as well as in Chuzhou in Anhui Province, Fujian Province, Guangxi Province, and Kowloon in Hong Kong. In 1939, Unit 8604 had six branches, each staffed by 225 men and headed by a medic major. The locations of these branches included Nanning and Qinzhou in Guangxi, as well as three branches in Guangzhou and one in Foshan in Guangdong. In particular, the 12th Field Epidemic Prevention and Water Purification Department was based in Xijiang Village on the northern outskirts of Guangzhou, the original site of the Chinese Fourth Route Army's Field Hospital and Military Medical School.
Biological warfare
The unit engaged in bacteriological research, normally breeding 10,000 rats per month and producing 10 kilograms of plague fleas.
In April 1943, Unit 731 and Unit 8604 had similar production capacities, each capable of producing 10 kilograms of plague-infected flea per month. After that, the Japanese records show that it had a smaller share of bacteria production.
In 1944, production increased to 15 kilograms per month following an order to increase output. According to confessions of a Japanese soldier, the unit had produced deadly bacteria for use against Chinese soldiers and civilians. Local residents had observed Japanese soldiers collecting rats with military vehicles and transporting them in carloads to Unit 8604.
150 kilograms were expected to be produced by Unit 731 of the Kwantung Army, 20 kilograms by Unit 1855 in North China, 30 kilograms by Unit 1644 in Central China, 10 kilograms by Unit 8604 in South China, 60 kilograms by Unit 9420 in Singapore, and 30 kilograms by the Army Medical School in Japan.
On 24 June 1945, the United States bombed and destroyed five rat breeding sheds and plague cultivation facilities of Unit 8604 with 25 to 26 B-29 bombers.
Nanshitou Massacre
According to a Japanese soldier of the unit, the Japanese invasion of Hong Kong from February to May 1942 resulted in a large number of Hong Kong refugees being forced to leave the city and flood upstream along the Pearl River into Guangzhou. Most of them were detained at the Nanshitou Refugee Camp and subjected to inhumane bacteriological warfare. The Japanese army sent planes to bring in Salmonella enteritidis (paratyphoid bacteria) from the Tokyo-based Army Medical School, and instructed the unit to put it into their food. The refugees unknowingly ingested the bacteria. Salmonella has a high mortality rate, and a succession of deaths ensued.
See also
Kwantung Army Epidemic Prevention and Water Supply Department Headquarters
References
Biological warfare facilities
Imperial Japanese Army
Japanese human subject research
Second Sino-Japanese War
Second Sino-Japanese War crimes
Japanese prisoner of war and internment camps
Japanese biological weapons program
Japanese war crimes in China | Unit 8604 | Biology | 945 |
53,704,008 | https://en.wikipedia.org/wiki/IEEE%20Visualization | The IEEE Visualization Conference (VIS) is an annual conference on scientific visualization, information visualization, and visual analytics administrated by the IEEE Computer Society Technical Committee on Visualization and Graphics. As ranked by Google Scholar's h-index metric in 2016, VIS is the highest rated venue for visualization research and the second-highest rated conference for computer graphics over all. It has an 'A' rating from the Australian Ranking of ICT Conferences, an 'A' rating from the Brazilian ministry of education, and an 'A' rating from the China Computer Federation (CCF). The conference is highly selective with generally < 25% acceptance rates for all papers.
An image dataset, VIS30K, has been created from figures and tables in the conference publications.
In 2016, the VIS Executive Committee initiated a review of conference structures, which led to community consultations and the formation of a committee in 2019, which successfully consolidated the three conferences (SciVis, InfoVis, VAST) under one conference at VIS 2021. Since the VIS 2021 conference a new unified full paper track with six specific areas and a consolidated review process is used. The unification of the conference structure aims to streamline experiences, simplify organizational processes, enhance flexibility in the evolution of topics, and provide a cohesive view of visualization fields.
Location
The conference is held in October and rotates around the US generally West, Central and East. In 2014, for its 25th anniversary, the conference took place for the first time outside of the US, namely in Paris.
List of conferences:
2024: St. Pete Beach, Florida, United States
2023: Melbourne, Australia
2022: Oklahoma City, United States (hybrid)
2021: New Orleans, United States (online)
2020: Salt Lake City, United States (online)
2019: Vancouver, Canada
2018: Berlin, Germany
2017: Phoenix, Arizona, United States
2016: Baltimore, Maryland, United States
2015: Chicago, Illinois, United States
2014: Paris, France
2013: Atlanta, Georgia, United States
2012: Seattle, Washington, United States
2011: Providence, Rhode Island, United States
2010: Salt Lake City, Utah, United States
2009: Atlantic City, New Jersey, United States
2008: Columbus, Ohio, United States
2007: Sacramento, California, United States
2006: Baltimore, Maryland, United States
2005: Minneapolis, Minnesota, United States
2004: Austin, Texas, United States
2003: Seattle, Washington, United States
2002: Boston, Massachusetts, United States
2001: San Diego, California, United States
2000: Salt Lake City, Utah, United States
1999: San Francisco, California, United States
1998: Research Triangle Park, North Carolina, United States
1997: Phoenix, Arizona, United States
1996: San Francisco, California, United States
1995: Atlanta, Georgia, United States
1994: Washington DC, United States
1993: San Jose, California, United States
1992: Boston, Massachusetts, United States
1991: San Diego, California, United States
1990: San Francisco, California, United States
Awards
VIS Best Paper Award
2023:
Affective Visualization Design: Leveraging the Emotional Impact of Data: Xingyu Lan, Yanqiu Wu, Nan Cao
Fast Compressed Segmentation Volumes for Scientific Visualization: Max Piochowiak, Carsten Dachsbacher
Swaying the Public? Impacts of Election Forecast Visualizations on Emotion, Trust, and Intention in the 2022 U.S. Midterms: Fumeng Yang, Mandi Cai, Chloe Rose Mortenson, Hoda Fakhari, Ayse Deniz Lokmanoglu, Jessica Hullman, Steven Franconeri, Nicholas Diakopoulos, Erik Nisbet, Matthew Kay
TimeSplines: Sketch-based Authoring of Flexible and Idiosyncratic Timelines: Anna Offenwanger, Matthew Brehmer, Fanny Chevalier, Theophanis Tsandilas
Visualization of Discontinuous Vector Field Topology: Egzon Miftari, Daniel Durstewitz, Filip Sadlo
Vortex Lens: Interactive Vortex Core Line Extraction using Observed Line Integral Convolution: Peter Rautek, Xingdi Zhang, Bernhard Woschizka, Thomas Theussl, Markus Hadwiger
2022:
Affective Learning Objectives for Communicative Visualizations: Elsie Lee-Robbins, Eytan Adar
Multiple Forecast Visualizations (MFVs): Trade-offs in Trust and Performance in Multiple COVID-19 Forecast Visualizations: Lace Padilla, Racquel Fygenson, Spencer C. Castro, Enrico Bertini
Uncertainty-Aware Multidimensional Scaling: David Hägele, Tim Krake, Daniel Weiskopf
2021:
Feature Curves and Surfaces of 3D Asymmetric Tensor Fields: Shih-Hsuan Hung, Yue Zhang, Harry Yeh, Eugene Zhang
IRVINE: Using Interactive Clustering and Labeling to Analyze Correlation Patterns: A Design Study from the Manufacturing of Electrical Engines: Joscha Eirich, Jakob Bonart, Dominik Jäckle, Michael Sedlmair, Ute Schmid, Kai Fischbach, Tobias Schreck, Jürgen Bernard
Perception! Immersion! Empowerment! Superpowers as Inspiration for Visualization: Wesley Willett, Bon Adriel Aseniero, Sheelagh Carpendale, Pierre Dragicevic, Yvonne Jansen, Lora Oehlberg, Petra Isenberg
Simultaneous Matrix Orderings for Graph Collections: Nathan van Beusekom, Wouter Meulemans, Bettina Speckmann
2020:
VAST
VATLD: A Visual Analytics System to Assess, Understand and Improve Traffic Light Detection: Liang Gou, Lincan Zou, Nanxiang Li, Michael Hofmann, Shekar Arvind Kumar, Axel Wendt, and Liu Ren
InfoVis
Visual Reasoning Strategies and Satisficing: How Uncertainty Visualization Design Impacts Effect Size Judgments and Decisions: Alex Kale, Matthew Kay, and Jessica Hullman
SciVis
Objective Observer-Relative Flow Visualization in Curved Spaces for Unsteady 2D Geophysical Flows: Peter Rautek, Matej Mlejnek, Johanna Beyer, Jakob Troidl, Hanspeter Pfister, Thomas Theussl, Markus Hadwiger
2019:
VAST
FlowSense: A Natural Language Interface for Visual Data Exploration within a Dataflow System: Bowen Yu, Claudio Silva
InfoVis
Data Changes Everything: Challenges and Opportunities in Data Visualization Design Handoff: Jagoda Walny, Christian Frisson, Mieka West, Doris Kosminsky, Søren Knudsen, Sheelagh Carpendale, Wesley Willett
SciVis
InSituNet: Deep Image Synthesis for Parameter Space Exploration of Ensemble Simulations: Wenbin He, Junpeng Wang, Hanqi Guo, Ko-Chih Wang, Han-Wei Shen, Mukund Raj, Youssef S. G. Nashed, Tom Peterka
2018:
VAST
TPFlow: Progressive Partition and Multidimensional Pattern Extraction for Large-Scale Spatio-Temporal Data Analysis, Dongyu Liu, Panpan Xu, Liu Ren
InfoVis
Formalizing Visualization Design Knowledge as Constraints: Actionable and Extensible Models in Draco, Dominik Moritz, Chenglong Wang, Greg L. Nelson, Halden Lin, Adam M. Smith, Bill Howe, Jeffrey Heer
SciVis
Deadeye: A Novel Preattentive Visualization Technique Based on Dichoptic Presentation Authors: Andrey Krekhov, Jens Krüger
2017:
VAST
Visualizing Dataflow Graphs of Deep Learning Models in TensorFlow, Kanit Wongsuphasawat, Daniel Smilkov, James Wexler, Jimbo Wilson, Dandelion Mané, Doug Fritz, Dilip Krishnan, Fernanda B. Viégas, and Martin Wattenberg
InfoVis
Modeling Color Difference for Visualization Design, Danielle Albers Szafir
SciVis
Globe Browsing: Contextualized Spatio-Temporal Planetary Surface Visualization, Karl Bladin, Emil Axelsson, Erik Broberg, Carter Emmart, Patric Ljung, Alexander Bock, and Anders Ynnerman
2016:
VAST
An Analysis of Machine- and Human-Analytics in Classification, Gary K.L. Tam, Vivek Kothari, Min Chen
InfoVis
Vega-Lite: A Grammar of Interactive Graphics, Arvind Satyanarayan, Dominik Moritz, Kanit Wongsuphasawat, and Jeffrey Heer
SciVis
Jacobi Fiber Surfaces for Bivariate Reeb Space Computation, Julien Tierny and Hamish Carr
2015
VAST
Reducing Snapshots to Points: A Visual Analytics Approach to Dynamic Network Exploration, Stef van den Elzen, Danny Holten, Jorik Blaas, Jarke van Wijk
InfoVis
HOLA: Human-like Orthogonal Network Layout, Steve Kieffer, Tim Dwyer, Kim Marriott, Michael Wybrow
SciVis
Visualization-by-Sketching: An Artist’s Interface for Creating Multivariate Time-Varying Data, David Schroeder, Daniel Keefe
2014
VAST
Supporting Communication and Coordination in Collaborative Sensemaking, Narges Mahyar, Melanie Tory
InfoVis
Multivariate Network Exploration and Presentation: From Detail to Overview via Selections and Aggregations, Stef van den Elzen, Jarke van Wijk
SciVis
Visualization of Brain Microstructure through Spherical Harmonics Illumination of High Fidelity Spatio-Angular Fields, Sujal Bista, Jiachen Zhou, Rao Gullapalli, Amitabh Varshney
2013
VAST
A Partition-Based Framework for Building and Validating Regression Models, Thomas Muhlbacher, Harald Piringer
InfoVis
LineUp: Visual Analysis of Multi-Attribute Rankings, Samuel Gratzl, Alexander Lex, Nils Gehlenborg, Hanspeter Pfister, Marc Streit
SciVis
Comparative Visual Analysis of Lagrangian Transport in CFD Ensembles, Mathias Hummel, Harald Obermaier, Christoph Garth, Kenneth I. Joy
Technical Achievement Award
Past recipients:
2024 - Bongshin Lee, Han-Wei Shen
2023 - Huamin Qu, Silvia Miksch
2022 - Valerio Pascucci, Shixia Liu
2021 - Daniel Weiskopf
2020 - Jean-Daniel Fekete
2019 - Eduard Gröller
2018 - Anders Ynnerman
2017 - Jeffrey Heer
2016 - David Ebert
2015 - Tamara Munzner
2014 - Claudio T. Silva
2013 - Kwan-Liu Ma
2012 - John Stasko
2011 - Daniel A. Keim
2010 - Hanspeter Pfister
2009 - Jock D. Mackinlay
2008 - David Laidlaw
2007 - Jarke van Wijk
2006 - Thomas Ertl
2005 - Charles D. Hansen
2004 - Amitabh Varshney
Career Award
To earn the IEEE VGTC Visualization Career Award, an individual must demonstrate that their research and service has had broad impacts on the field over a long period of time. Since 2021 it is called Lifetime Achievement.
Past recipients:
2024 - Hans-Christian Hege and Min Chen
2023 - John Stasko
2022 - Colin Ware
2021 - Jarke van Wijk
2020 - Catherine Plaisant
2019 - Thomas Ertl
2018 - Sheelagh Carpendale
2017 - Charles D. Hansen
2016 - John C. Dill
2015 - Markus Gross
2014 - Kenneth Joy
2013 - Gregory M. Nielson
2012 - Ben Shneiderman
2011 - Frits Post
2010 - Christopher R. Johnson
2009 - Hans Hagen
2008 - Lawrence J. Rosenblum
2007 - Stuart Card
2006 - Pat Hanrahan
2005 - Arie Kaufman
2004 - Bill Lorensen
References
IEEE conferences
Computer science conferences
IEEE society and council awards
Visualization (research) | IEEE Visualization | Technology | 2,388 |
1,372 | https://en.wikipedia.org/wiki/Amber | Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity. Amber is used in jewelry and as a healing agent in folk medicine.
There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ambrite is applied to that found specifically within New Zealand coal seams.
Etymology
The English word amber derives from Arabic via Middle Latin ambar and Middle French ambre. The word referred to what is now known as ambergris (ambre gris or "gray amber"), a solid waxy substance derived from the sperm whale. The word, in its sense of "ambergris," was adopted in Middle English in the 14th century.
In the Romance languages, the sense of the word was extended to Baltic amber (fossil resin) from as early as the late 13th century. At first called white or yellow amber (ambre jaune), this meaning was adopted in English by the early 15th century. As the use of ambergris waned, this became the main sense of the word.
The two substances ("yellow amber" and "gray amber") conceivably became associated or confused because they both were found washed up on beaches. Ambergris is less dense than water and floats, whereas amber is too dense to float, though less dense than stone.
The classical names for amber, Ancient Greek (ēlektron) and one of* its Latin names, electrum, are connected to a term ἠλέκτωρ (ēlektōr) meaning "beaming Sun". According to myth, when Phaëton son of Helios (the Sun) was killed, his mourning sisters became poplar trees, and their tears became elektron, amber. The word elektron gave rise to the words electric, electricity, and their relatives because of amber's ability to bear a charge of static electricity. (*In Latin the name succinum was unambiguously used for amber while electrum was also used for an alloy of gold and silver).
Varietal names
A number of regional and varietal names have been applied to ambers over the centuries, including Allingite, Beckerite, Gedanite, Kochenite, Krantzite, and Stantienite.
History
Theophrastus discussed amber in the 4th century BCE, as did Pytheas (), whose work "On the Ocean" is lost, but was referenced by Pliny, according to whose Natural History:
Earlier Pliny says that Pytheas refers to a large island—three days' sail from the Scythian coast and called Balcia by Xenophon of Lampsacus (author of a fanciful travel book in Greek)—as Basilia—a name generally equated with Abalus. Given the presence of amber, the island could have been Heligoland, Zealand, the shores of Gdańsk Bay, the Sambia Peninsula or the Curonian Lagoon, which were historically the richest sources of amber in northern Europe. There were well-established trade routes for amber connecting the Baltic with the Mediterranean (known as the "Amber Road"). Pliny states explicitly that the Germans exported amber to Pannonia, from where the Veneti distributed it onwards.
The ancient Italic peoples of southern Italy used to work amber; the National Archaeological Museum of Siritide (Museo Archeologico Nazionale della Siritide) at Policoro in the province of Matera (Basilicata) displays important surviving examples. It has been suggested that amber used in antiquity, as at Mycenae and in the prehistory of the Mediterranean, came from deposits in Sicily.
Pliny also cites the opinion of Nicias ( 470–413 BCE), according to whom amber Besides the fanciful explanations according to which amber is "produced by the Sun", Pliny cites opinions that are well aware of its origin in tree resin, citing the native Latin name of succinum (sūcinum, from sucus "juice"). In Book 37, section XI of Natural History, Pliny wrote:
He also states that amber is also found in Egypt and India, and he even refers to the electrostatic properties of amber, by saying that "in Syria the women make the whorls of their spindles of this substance, and give it the name of harpax [from ἁρπάζω, "to drag"] from the circumstance that it attracts leaves towards it, chaff, and the light fringe of tissues".
The Romans traded for amber from the shores of the southern Baltic at least as far back as the time of Nero.
Amber has a long history of use in China, with the first written record from 200 BCE. Early in the 19th century, the first reports of amber found in North America came from discoveries in New Jersey along Crosswicks Creek near Trenton, at Camden, and near Woodbury.
Composition and formation
Amber is heterogeneous in composition, but consists of several resinous more or less soluble in alcohol, ether and chloroform, associated with an insoluble bituminous substance. Amber is a macromolecule formed by free radical polymerization of several precursors in the labdane family, for example, communic acid, communol, and biformene. These labdanes are diterpenes (C20H32) and trienes, equipping the organic skeleton with three alkene groups for polymerization. As amber matures over the years, more polymerization takes place as well as isomerization reactions, crosslinking and cyclization.
Most amber has a hardness between 2.0 and 2.5 on the Mohs scale, a refractive index of 1.5–1.6, a specific gravity between 1.06 and 1.10, and a melting point of 250–300 °C. Heated above , amber decomposes, yielding an oil of amber, and leaves a black residue which is known as "amber colophony", or "amber pitch"; when dissolved in oil of turpentine or in linseed oil this forms "amber varnish" or "amber lac".
Molecular polymerization, resulting from high pressures and temperatures produced by overlying sediment, transforms the resin first into copal. Sustained heat and pressure drives off terpenes and results in the formation of amber. For this to happen, the resin must be resistant to decay. Many trees produce resin, but in the majority of cases this deposit is broken down by physical and biological processes. Exposure to sunlight, rain, microorganisms, and extreme temperatures tends to disintegrate the resin. For the resin to survive long enough to become amber, it must be resistant to such forces or be produced under conditions that exclude them. Fossil resins from Europe fall into two categories, the Baltic ambers and another that resembles the Agathis group. Fossil resins from the Americas and Africa are closely related to the modern genus Hymenaea, while Baltic ambers are thought to be fossil resins from plants of the family Sciadopityaceae that once lived in north Europe.
The abnormal development of resin in living trees (succinosis) can result in the formation of amber. Impurities are quite often present, especially when the resin has dropped onto the ground, so the material may be useless except for varnish-making. Such impure amber is called firniss. Such inclusion of other substances can cause the amber to have an unexpected color. Pyrites may give a bluish color. Bony amber owes its cloudy opacity to numerous tiny bubbles inside the resin. However, so-called black amber is really a kind of jet. In darkly clouded and even opaque amber, inclusions can be imaged using high-energy, high-contrast, high-resolution X-rays.
Extraction and processing
Distribution and mining
Amber is globally distributed in or around all continents, mainly in rocks of Cretaceous age or younger. Historically, the coast west of Königsberg in Prussia was the world's leading source of amber. The first mentions of amber deposits there date back to the 12th century. Juodkrantė in Lithuania was established in the mid-19th century as a mining town of amber. About 90% of the world's extractable amber is still located in that area, which was transferred to the Russian Soviet Federative Socialist Republic of the USSR in 1946, becoming the Kaliningrad Oblast.
Pieces of amber torn from the seafloor are cast up by the waves and collected by hand, dredging, or diving. Elsewhere, amber is mined, both in open works and underground galleries. Then nodules of blue earth have to be removed and an opaque crust must be cleaned off, which can be done in revolving barrels containing sand and water. Erosion removes this crust from sea-worn amber. Dominican amber is mined through bell pitting, which is dangerous because of the risk of tunnel collapse.
An important source of amber is Kachin State in northern Myanmar, which has been a major source of amber in China for at least 1,800 years. Contemporary mining of this deposit has attracted attention for unsafe working conditions and its role in funding internal conflict in the country. Amber from the Rivne Oblast of Ukraine, referred to as Rivne amber, is mined illegally by organised crime groups, who deforest the surrounding areas and pump water into the sediments to extract the amber, causing severe environmental deterioration.
Treatment
The Vienna amber factories, which use pale amber to manufacture pipes and other smoking tools, turn it on a lathe and polish it with whitening and water or with rotten stone and oil. The final luster is given by polishing with flannel.
When gradually heated in an oil bath, amber "becomes soft and flexible. Two pieces of amber may be united by smearing the surfaces with linseed oil, heating them, and then pressing them together while hot. Cloudy amber may be clarified in an oil bath, as the oil fills the numerous pores that cause the turbidity. Small fragments, formerly thrown away or used only for varnish are now used on a large scale in the formation of "ambroid" or "pressed amber". The pieces are carefully heated with exclusion of air and then compressed into a uniform mass by intense hydraulic pressure, the softened amber being forced through holes in a metal plate. The product is extensively used for the production of cheap jewelry and articles for smoking. This pressed amber yields brilliant interference colors in polarized light."
Amber has often been imitated by other resins like copal and kauri gum, as well as by celluloid and even glass. Baltic amber is sometimes colored artificially but also called "true amber".
Appearance
Amber occurs in a range of different colors. As well as the usual yellow-orange-brown that is associated with the color "amber", amber can range from a whitish color through a pale lemon yellow, to brown and almost black. Other uncommon colors include red amber (sometimes known as "cherry amber"), green amber, and even blue amber, which is rare and highly sought after.
Yellow amber is a hard fossil resin from evergreen trees, and despite the name it can be translucent, yellow, orange, or brown colored. Known to the Iranians by the Pahlavi compound word kah-ruba (from kah "straw" plus rubay "attract, snatch", referring to its electrical properties), which entered Arabic as kahraba' or kahraba (which later became the Arabic word for electricity, كهرباء kahrabā), it too was called amber in Europe (Old French and Middle English ambre). Found along the southern shore of the Baltic Sea, yellow amber reached the Middle East and western Europe via trade. Its coastal acquisition may have been one reason yellow amber came to be designated by the same term as ambergris. Moreover, like ambergris, the resin could be burned as an incense. The resin's most popular use was, however, for ornamentation—easily cut and polished, it could be transformed into beautiful jewelry. Much of the most highly prized amber is transparent, in contrast to the very common cloudy amber and opaque amber. Opaque amber contains numerous minute bubbles. This kind of amber is known as "bony amber".
Although all Dominican amber is fluorescent, the rarest Dominican amber is blue amber. It turns blue in natural sunlight and any other partially or wholly ultraviolet light source. In long-wave UV light it has a very strong reflection, almost white. Only about is found per year, which makes it valuable and expensive.
Sometimes amber retains the form of drops and stalactites, just as it exuded from the ducts and receptacles of the injured trees. It is thought that, in addition to exuding onto the surface of the tree, amber resin also originally flowed into hollow cavities or cracks within trees, thereby leading to the development of large lumps of amber of irregular form.
Classification
Amber can be classified into several forms. Most fundamentally, there are two types of plant resin with the potential for fossilization. Terpenoids, produced by conifers and angiosperms, consist of ring structures formed of isoprene (C5H8) units. Phenolic resins are today only produced by angiosperms, and tend to serve functional uses. The extinct medullosans produced a third type of resin, which is often found as amber within their veins. The composition of resins is highly variable; each species produces a unique blend of chemicals which can be identified by the use of pyrolysis–gas chromatography–mass spectrometry. The overall chemical and structural composition is used to divide ambers into five classes. There is also a separate classification of amber gemstones, according to the way of production.
Class I
This class is by far the most abundant. It comprises labdatriene carboxylic acids such as communic or ozic acids. It is further split into three sub-classes. Classes Ia and Ib utilize regular labdanoid diterpenes (e.g. communic acid, communol, biformenes), while Ic uses enantio labdanoids (ozic acid, ozol, enantio biformenes).
Class Ia includes Succinite (= 'normal' Baltic amber) and Glessite. They have a communic acid base, and they also include much succinic acid. Baltic amber yields on dry distillation succinic acid, the proportion varying from about 3% to 8%, and being greatest in the pale opaque or bony varieties. The aromatic and irritating fumes emitted by burning amber are mainly from this acid. Baltic amber is distinguished by its yield of succinic acid, hence the name succinite. Succinite has a hardness between 2 and 3, which is greater than many other fossil resins. Its specific gravity varies from 1.05 to 1.10. It can be distinguished from other ambers via infrared spectroscopy through a specific carbonyl absorption peak. Infrared spectroscopy can detect the relative age of an amber sample. Succinic acid may not be an original component of amber but rather a degradation product of abietic acid.
Class Ib ambers are based on communic acid; however, they lack succinic acid.
Class Ic is mainly based on enantio-labdatrienonic acids, such as ozic and zanzibaric acids. Its most familiar representative is Dominican amber,. which is mostly transparent and often contains a higher number of fossil inclusions. This has enabled the detailed reconstruction of the ecosystem of a long-vanished tropical forest. Resin from the extinct species Hymenaea protera is the source of Dominican amber and probably of most amber found in the tropics. It is not "succinite" but "retinite".
Class II
These ambers are formed from resins with a sesquiterpenoid base, such as cadinene.
Class III
These ambers are polystyrenes.
Class IV
Class IV is something of a catch-all: its ambers are not polymerized, but mainly consist of cedrene-based sesquiterpenoids.
Class V
Class V resins are considered to be produced by a pine or pine relative. They comprise a mixture of diterpinoid resins and n-alkyl compounds. Their main variety is Highgate copalite.
Geological record
The oldest amber recovered dates to the late Carboniferous period (). Its chemical composition makes it difficult to match the amber to its producers – it is most similar to the resins produced by flowering plants; however, the first flowering plants appeared in the Early Cretaceous, about 200 million years after the oldest amber known to date, and they were not common until the Late Cretaceous. Amber becomes abundant long after the Carboniferous, in the Early Cretaceous, when it is found in association with insects. The oldest amber with arthropod inclusions comes from the Late Triassic (late Carnian 230 Ma) of Italy, where four microscopic (0.2–0.1 mm) mites, Triasacarus, Ampezzoa, Minyacarus and Cheirolepidoptus, and a poorly preserved nematoceran fly were found in millimetre-sized droplets of amber. The oldest amber with significant numbers of arthropod inclusions comes from Lebanon. This amber, referred to as Lebanese amber, is roughly 125–135 million years old, is considered of high scientific value, providing evidence of some of the oldest sampled ecosystems.
In Lebanon, more than 450 outcrops of Lower Cretaceous amber were discovered by Dany Azar, a Lebanese paleontologist and entomologist. Among these outcrops, 20 have yielded biological inclusions comprising the oldest representatives of several recent families of terrestrial arthropods. Even older Jurassic amber has been found recently in Lebanon as well. Many remarkable insects and spiders were recently discovered in the amber of Jordan including the oldest zorapterans, clerid beetles, umenocoleid roaches, and achiliid planthoppers.
Burmese amber from the Hukawng Valley in northern Myanmar is the only commercially exploited Cretaceous amber. Uranium–lead dating of zircon crystals associated with the deposit have given an estimated depositional age of approximately 99 million years ago. Over 1,300 species have been described from the amber, with over 300 in 2019 alone.
Baltic amber is found as irregular nodules in marine glauconitic sand, known as blue earth, occurring in Upper Eocene strata of Sambia in Prussia. It appears to have been partly derived from older Eocene deposits and it occurs also as a derivative phase in later formations, such as glacial drift. Relics of an abundant flora occur as inclusions trapped within the amber while the resin was yet fresh, suggesting relations with the flora of eastern Asia and the southern part of North America. Heinrich Göppert named the common amber-yielding pine of the Baltic forests Pinites succiniter, but as the wood does not seem to differ from that of the existing genus it has been also called Pinus succinifera. It is improbable that the production of amber was limited to a single species; and indeed a large number of conifers belonging to different genera are represented in the amber-flora.
Paleontological significance
Amber is a unique preservational mode, preserving otherwise unfossilizable parts of organisms; as such it is helpful in the reconstruction of ecosystems as well as organisms; the chemical composition of the resin, however, is of limited utility in reconstructing the phylogenetic affinity of the resin producer. Amber sometimes contains animals or plant matter that became caught in the resin as it was secreted. Insects, spiders and even their webs, annelids, frogs, crustaceans, bacteria and amoebae, marine microfossils, wood, flowers and fruit, hair, feathers and other small organisms have been recovered in Cretaceous ambers (deposited c. ). There is even an ammonite Puzosia (Bhimaites) and marine gastropods found in Burmese amber.
The preservation of prehistoric organisms in amber forms a key plot point in Michael Crichton's 1990 novel Jurassic Park and the 1993 movie adaptation by Steven Spielberg. In the story, scientists are able to extract the preserved blood of dinosaurs from prehistoric mosquitoes trapped in amber, from which they genetically clone living dinosaurs. Scientifically this is as yet impossible, since no amber with fossilized mosquitoes has ever yielded preserved blood. Amber is, however, conducive to preserving DNA, since it dehydrates and thus stabilizes organisms trapped inside. One projection in 1999 estimated that DNA trapped in amber could last up to 100 million years, far beyond most estimates of around 1 million years in the most ideal conditions, although a later 2013 study was unable to extract DNA from insects trapped in much more recent Holocene copal. In 1938, 12-year-old David Attenborough (brother of Richard who played John Hammond in Jurassic Park) was given a piece of amber containing prehistoric creatures from his adoptive sister; it would be the focus of his 2004 BBC documentary The Amber Time Machine.
Use
Amber has been used since prehistory (Solutrean) in the manufacture of jewelry and ornaments, and also in folk medicine.
Jewelry
Amber has been used as jewelry since the Stone Age, from 13,000 years ago. Amber ornaments have been found in Mycenaean tombs and elsewhere across Europe. To this day it is used in the manufacture of smoking and glassblowing mouthpieces. Amber's place in culture and tradition lends it a tourism value; Palanga Amber Museum is dedicated to the fossilized resin.
Historical medicinal uses
Amber has long been used in folk medicine for its purported healing properties. Amber and extracts were used from the time of Hippocrates in ancient Greece for a wide variety of treatments through the Middle Ages and up until the early twentieth century. Traditional Chinese medicine uses amber to "tranquilize the mind".
Amber necklaces are a traditional European remedy for colic or teething pain with purported analgesic properties of succinic acid, although there is no evidence that this is an effective remedy or delivery method. The American Academy of Pediatrics and the FDA have warned strongly against their use, as they present both a choking and a strangulation hazard.
Scent of amber and amber perfumery
In ancient China, it was customary to burn amber during large festivities. If amber is heated under the right conditions, oil of amber is produced, and in past times this was combined carefully with nitric acid to create "artificial musk" – a resin with a peculiar musky odor. Although when burned, amber does give off a characteristic "pinewood" fragrance, modern products, such as perfume, do not normally use actual amber because fossilized amber produces very little scent. In perfumery, scents referred to as "amber" are often created and patented to emulate the opulent golden warmth of the fossil.
The scent of amber was originally derived from emulating the scent of ambergris and/or the plant resin labdanum, but since sperm whales are endangered, the scent of amber is now largely derived from labdanum. The term "amber" is loosely used to describe a scent that is warm, musky, rich and honey-like, and also somewhat earthy. Benzoin is usually part of the recipe. Vanilla and cloves are sometimes used to enhance the aroma. "Amber" perfumes may be created using combinations of labdanum, benzoin resin, copal (a type of tree resin used in incense manufacture), vanilla, Dammara resin and/or synthetic materials.
In Arab Muslim tradition, popular scents include amber, jasmine, musk and oud (agarwood).
Imitation substances
Young resins used as imitations:
Kauri resin from Agathis australis trees in New Zealand.
The copals (subfossil resins). The African and American (Colombia) copals from Leguminosae trees family (genus Hymenaea). Amber of the Dominican or Mexican type (Class I of fossil resins). Copals from Manilia (Indonesia) and from New Zealand from trees of the genus Agathis (family Araucariaceae)
Other fossil resins: burmite in Burma, rumenite in Romania, and simetite in Sicily.
Other natural resins — cellulose or chitin, etc.
Plastics used as imitations:
Stained glass (inorganic material) and other ceramic materials
Celluloid
Cellulose nitrate (first obtained in 1833) — a product of treatment of cellulose with nitration mixture.
Acetylcellulose (not in the use at present)
Galalith or "artificial horn" (condensation product of casein and formaldehyde), other trade names: Alladinite, Erinoid, Lactoid.
Casein — a conjugated protein forming from the casein precursor – caseinogen.
Resolane (phenolic resins or phenoplasts, not in the use at present)
Bakelite resine (resol, phenolic resins), product from Africa are known under the misleading name "African amber".
Carbamide resins — melamine, formaldehyde and urea-formaldehyde resins.
Epoxy novolac (phenolic resins), unofficial name "antique amber", not in the use at present
Polyesters (Polish amber imitation) with styrene. For example, unsaturated polyester resins (polymals) are produced by Chemical Industrial Works "Organika" in Sarzyna, Poland; estomal are produced by Laminopol firm. Polybern or sticked amber is artificial resins the curled chips are obtained, whereas in the case of amber – small scraps. "African amber" (polyester, synacryl is then probably other name of the same resine) are produced by Reichhold firm; Styresol trade mark or alkid resin (used in Russia, Reichhold, Inc. patent, 1948.
Polyethylene
Epoxy resins
Polystyrene and polystyrene-like polymers (vinyl polymers).
The resins of acrylic type (vinyl polymers), especially polymethyl methacrylate PMMA (trade mark Plexiglass, metaplex).
See also
Ammolite
Illyrian amber jewellery
List of types of amber
Petrified wood
Pearl
Poly(methyl methacrylate)
Precious coral
References
Bibliography
External links
Farlang many full text historical references on Amber Theophrastus, George Frederick Kunz, and special on Baltic amber.
IPS Publications on amber inclusions International Paleoentomological Society: Scientific Articles on amber and its inclusions
Webmineral on Amber Physical properties and mineralogical information
Mindat Amber Image and locality information on amber
NY Times 40 million year old extinct bee in Dominican amber
Fossil resins
Amorphous solids
Traditional medicine | Amber | Physics | 5,680 |
20,494,205 | https://en.wikipedia.org/wiki/National%20Interop | National Interop is a systems integration company with some of the earliest experience with Radio over IP technologies as deployed for public safety communications. The company was founded by public safety personnel.
One of the principals of the company testified in the U.S. Senate in 2007 on the applicability of Radio over IP (RoIP) as an alternative for the expensive statewide interoperable radio systems then being proposed for funding by the federal government at costs of about $US 1B per state.
The company designed and implemented a RoIP-powered system for Air Evac Lifeteam spanning 14 states with 80+ radio towers and a 24x7 9-1-1 type dispatch center, as well as numerous smaller RoIP systems.
National Interop works with any and all RoIP technologies, as each may be best suited for each particular public safety application.
References
External links
Air Evac Lifeteam (AEL) website
Twisted Pair WAVE website
Telex Vega VOIP website, part of Telex Communications
IPICS wiki by Cisco
Interoperable communications
Radio communications
Public safety communications | National Interop | Engineering | 217 |
2,529,967 | https://en.wikipedia.org/wiki/Back%20scattering%20alignment | The Back Scattering Alignment (BSA) is a coordinate system used in coherent electromagnetic scattering. The coordinate system is defined from the viewpoint of the wave source, before and after scattering. The BSA is most commonly used in radar, specifically when working with a Sinclair Matrix because the monostatic radar detector and source are physically coaligned. BSA gives rise to conjugate eigenvalue equations. The alternative coordinate system in electromagnetic scattering is the Forward Scattering Alignment (FSA) which is primarily used in optics. Both coordinate systems contain essentially the same information and meaning, and thus a scattering matrix can be transformed from one to the other by use of the matrix,
References
See also
Backscatter
Electromagnetic radiation
Electromagnetic radiation | Back scattering alignment | Physics,Materials_science | 146 |
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 |
25,819,167 | https://en.wikipedia.org/wiki/HD%2013931%20b | HD 13931 b (also known as HIP 10626 b) is an extrasolar planet which orbits the G-type star HD 13931, located approximately 155 light years away in the constellation Andromeda. This planet takes 11.55 years to orbit the star at the average distance of 5.15 AU or 770 Gm. The planet's eccentricity (0.02) is about the same as Earth. The orbital distance for this planet ranges from 5.05 to 5.25 AU. This planet was discovered by using radial velocity method from spectrograph taken at Keck Observatory on November 13, 2009.
In 2023, the inclination and true mass of HD 13931 b were measured via astrometry.
See also
Other planets that were discovered or confirmed on November 13, 2009:
HD 34445 b
HD 126614 Ab
Gliese 179 b
References
Exoplanets discovered in 2009
Exoplanets detected by radial velocity
Giant planets
Andromeda (constellation)
Exoplanets detected by astrometry | HD 13931 b | Astronomy | 208 |
649,422 | https://en.wikipedia.org/wiki/Great%20Man-Made%20River | The Great Man-Made River (GMMR, , ) is a network of pipes that supplies fresh water obtained from the Nubian Sandstone Aquifer System fossil aquifer across Libya. It is the world's largest irrigation project. The project utilizes a pipeline system that pumps water from the Nubian Sandstone Aquifer System from southern Libya to cities in the populous Libyan northern Mediterranean coast including Tripoli and Benghazi. The water covers a distance of up to 1,600 kilometers and provides 70% of all freshwater used in Libya.
According to the project's website, it is the largest underground network of pipes () and aqueducts in the world. It consists of more than 1,300 wells, most more than 500 m deep, and supplies 6,500,000 m3 of fresh water per day to the cities of Tripoli, Benghazi, Sirte and elsewhere in Libya. The late Libyan Leader Muammar Gaddafi described it as the "Eighth Wonder of the World".
History
In 1953, efforts to find oil in southern Libya led to the discovery of large quantities of potable fossil water underground. The Great Man-Made River Project (GMRP) was conceived in the late 1960s and work on the project began in 1984. The project's construction was divided into five phases. The first phase required 85 million m³ of excavation and was inaugurated on 28 August 1991. The second phase (dubbed First water to Tripoli) was inaugurated on 1 September 1996.
The project is owned by the Great Man-Made River Project Authority and was funded by the Gaddafi government. The primary contractor for the first phases was Dong Ah Consortium (a South Korean company) and the present main contractor is Al Nahr Company Ltd.
Imported goods which were destined for use in the construction of the GMR were made in Korea and Europe (mainly in Italy) and arrived by sea via the entry port of Brega (Gulf of Sidra). Cathodic corrosion protection on the pipeline was supplied by an Australian company, AMAC Corrosion Protection, based in Melbourne and delivered via the port of Benghazi. The rest of the material was made in Libya.
The total cost of the GMRP was projected at more than US$25 billion. Libya has completed the work to date without the financial support of major countries or loans from world banks. Since 1990, UNESCO has provided training to engineers and technicians involved with the project.
The fossil aquifer from which this water is being supplied is the Nubian Sandstone Aquifer System. It accumulated during the last ice age and is not currently being replenished. If 2007 rates of retrieval are not increased, the water could last a thousand years. Other estimates indicate that the aquifer could be depleted of water in as soon as 60 to 100 years. Analysts say that the costs of the $25 billion groundwater extraction system are 10% those of desalination.
In this project 1 billion euros were invested for the installation of 50,000 artificial palm trees for water condensation. This project was carried out by the Spanish engineer Antonio Ibáñez de Alba.
On 22 July 2011, during the First Libyan Civil War and the foreign military intervention, one of the two plants making pipes for the project, the Brega Plant, was hit by a NATO air strike. At a press conference on 26 July, NATO claimed that rockets had been fired from within the plant area, and that military materiel, including multiple rocket launchers, was stored there according to intelligence findings, presenting two photos of an BM-21 MRL as sole evidence for the destruction of the factory. The evidence for a potential UN resolutions breach has been insufficient.
During the Second Libyan Civil War from 2014 to 2020, the water infrastructure suffered neglect and occasional breakdowns. As of July 2019, 101 of 479 wells on the western pipeline system had been dismantled.
On 10 April 2020, a station controlling water flow to Tripoli and neighboring towns was seized by an unknown armed group. The flow of water was cut to over two million people as a result, and as such the attack was condemned by the United Nations on humanitarian grounds.
Timeline
3 October 1983: The General People's Congress held an extraordinary session to draft the resolutions of the Basic People's Congresses, which decided to fund and execute the Great Man-Made River Project.
28 August 1984: Muammar Gaddafi laid the foundation stone in Sarir area for the commencement of the construction of the Great Man-Made River Project.
28 August 1986: Muammar Gaddafi inaugurated the Brega plant for the production of the pre-stressed concrete cylinder pipes, which are considered the largest pipes made with pre-stressed steel wire (the majority of steel wire was made in Italy by the Redaelli Tecna S.p.A. company with its head office in Cologno Monzese-Milan and its factory in Caivano-Naples). The Sarir plant was also inaugurated on this date.
26 August 1989: Muammar Gaddafi laid the foundation stone for phase two of the Great Man-Made River Project.
First water arrival
11 September 1989: to Ajdabiya reservoir.
28 September 1989: to Grand Omar Muktar reservoir.
4 September 1991: to Ghardabiya reservoir.
28 August 1996: to Tripoli.
28 September 2007: to Gharyan.
Gallery
See also
Center pivot irrigation
Dragon's Breath Cave: another fossil water store in an arid area in Africa
Qanat
Water transfer to central Iranian plateau
References
Additional sources
BBC News: Libya's thirst for 'fossil water' (article contains map of pipe network)
Project article at Encyclopædia Britannica
TEKFEN İNŞAAT official article
External links
Nubian Sandstone Aquifer System Project Joint project of IAEA UNDP and GEF about the Great Manmade River logistics.
Great Man-Made River International Water Prize
Great Man-Made River website at AlGaddaf.org
Geography of Libya
Economy of Libya
Water supply and sanitation in Libya
Muammar Gaddafi
Interbasin transfer | Great Man-Made River | Environmental_science | 1,226 |
488,564 | https://en.wikipedia.org/wiki/Eugene%20Koonin | Eugene Viktorovich Koonin (Russian: Евге́ний Ви́кторович Ку́нин; born October 26, 1956) is a Russian-American biologist and Senior Investigator at the National Center for Biotechnology Information (NCBI). He is a recognised expert in the field of evolutionary and computational biology.
Education
Koonin gained a Master of Science in 1978 and a PhD in 1983 in molecular biology, both from the Department of Biology at Moscow State University. His PhD thesis, titled "Multienzyme organization of encephalomyocarditis virus replication complexes", was supervised by Vadim I. Agol.
Research
From 1985 until 1991, Koonin worked as a research scientist in computational biology in the Institutes of Poliomyelitis and Microbiology at the USSR Academy of Medical Sciences, studying virus biochemistry and bacterial genetics. In 1991, Koonin moved to the NCBI, where he has held a Senior Investigator position since 1996.
Koonin's principal research goals include the comparative analysis of sequenced genomes and automatic methods for genome-scale annotation of gene functions. He also researches in the application of comparative genomics for phylogenetic analysis, reconstruction of ancestral life forms and building large-scale evolutionary scenarios, as well as mathematical modeling of genome evolution. Koonin's research also investigates computational study of the major transitions in the evolution of life, such as the origin of eukaryotes, the evolution of eukaryotic signaling and developmental pathways from the comparative-genomic perspective.
Koonin is an advocate of the extended evolutionary synthesis.
In 2011 Koonin outlined his views on evolution in the book "The Logic of Chance: The Nature and Origin of Biological Evolution".
Career
Koonin has worked as adjunct professor at the Georgia Institute of Technology, Boston University and the University of Haifa.
As of 2014, Koonin serves on the advisory editorial board of Trends in Genetics, and is co-Editor-in-Chief of the open access journal Biology Direct. He served on the editorial board of Bioinformatics from 1999 until 2001. Koonin is also an advisory board member in bioinformatics at Faculty of 1000.
In 2016 he was elected to the National Academy of Sciences.
In 2016, Semantic Scholar AI program included Koonin on its list of top ten most influential biomedical researchers.
Political positions
In February 2022, he signed an open letter by Russian scientists condemning the 2022 Russian invasion of Ukraine, and renounced his membership in the Russian Academy of Sciences out of protest.
References
Selected bibliography
HAL Id: 02861246.
External links
1956 births
Living people
Theoretical biologists
Russian bioinformaticians
Extended evolutionary synthesis
Human Genome Project scientists
Members of the United States National Academy of Sciences
Foreign members of the Russian Academy of Sciences
21st-century American biologists
Moscow State University alumni
Members of the National Academy of Medicine | Eugene Koonin | Engineering | 593 |
14,891,001 | https://en.wikipedia.org/wiki/Idazoxan | Idazoxan (INN) is a drug which is used in scientific research. It acts as both a selective α2 adrenergic receptor antagonist, and an antagonist for the imidazoline receptor. Idazoxan has been under investigation as an antidepressant, but it did not reach the market as such. More recently, it is under investigation as an adjunctive treatment in schizophrenia. Due to its α2 receptor antagonism it is capable of enhancing therapeutic effects of antipsychotics, possibly by enhancing dopamine neurotransmission in the prefrontal cortex of the brain, a brain area thought to be involved in the pathogenesis of schizophrenia.
Alzheimer's research
Mice treated with idazoxan, which blocks the α2A receptor which regulates norepinephrine, behaved similarly to control animals despite still having amyloid-beta plaques in the brain, as a proof-of-concept experiment that dramatically reduced Alzheimer's pathology and symptoms in two mouse models, potentially offering an immediate treatment for this devastating disease.
Synthesis
Note that the literature method claims that the old original patented procedure gives a different reaction product formed through a rearrangement.
The reaction of catechol (1) with 2-Chloroacrylonitrile [920-37-6] (2) gives 2-cyano-1,4-benzodioxan [1008-92-0] (3). Pinner reaction with alcoholic hydrogen chloride leads to the iminoether, (4). Treatment with ethylenediamine [107-15-3] (5) gives the imidazoline ring affording (6).
See also
Imiloxan
Efaroxan
Fluparoxan
References
Alpha blockers
Imidazoline antagonists
Benzodioxans
Imidazolines | Idazoxan | Chemistry | 383 |
23,432,071 | https://en.wikipedia.org/wiki/Purity%20%28quantum%20mechanics%29 | In quantum mechanics, and especially quantum information theory, the purity of a normalized quantum state is a scalar defined as
where is the density matrix of the state and is the trace operation. The purity defines a measure on quantum states, giving information on how much a state is mixed.
Mathematical properties
The purity of a normalized quantum state satisfies , where is the dimension of the Hilbert space upon which the state is defined. The upper bound is obtained by and (see trace).
If is a projection, which defines a pure state, then the upper bound is saturated: (see Projections). The lower bound is obtained by the completely mixed state, represented by the matrix .
The purity of a quantum state is conserved under unitary transformations acting on the density matrix in the form , where is a unitary matrix. Specifically, it is conserved under the time evolution operator , where is the Hamiltonian operator.
Physical meaning
A pure quantum state can be represented as a single vector in the Hilbert space. In the density matrix formulation, a pure state is represented by the matrix
However, a mixed state cannot be represented this way, and instead is represented by a convex combination of pure states
while for normalization. The purity parameter is related to the coefficients: If only one coefficient is equal to 1, the state is pure. Indeed, the purity is when the state is completely mixed, i.e.
where are orthonormal vectors that constitute a basis of the Hilbert space.
Geometrical representation
On the Bloch sphere, pure states are represented by a point on the surface of the sphere, whereas mixed states are represented by an interior point. Thus, the purity of a state can be visualized as the degree to which the point is close to the surface of the sphere.
For example, the completely mixed state of a single qubit is represented by the center of the sphere, by symmetry.
A graphical intuition of purity may be gained by looking at the relation between the density matrix and the Bloch sphere,
where is the vector representing the quantum state (on or inside the sphere), and is the vector of the Pauli matrices.
Since Pauli matrices are traceless, it still holds that . However, by virtue of
hence
which agrees with the fact that only states on the surface of the sphere itself are pure (i.e. ).
Relation to other concepts
Linear entropy
Purity is trivially related to the linear entropy of a state by
The linear entropy is a lower approximation to the von Neumann entropy S, which is defined as
The linear entropy then is obtained by expanding , around a pure state, ; that is, expanding in terms of the non-negative matrix in the formal Mercator series for the logarithm,
and retaining just the leading term. Both the linear and the von Neumann entropy measure the degree of mixing of a state, although the linear entropy is easier to calculate, as it does not require diagonalization of the density matrix. Some authors define linear entropy with a different normalization
which ensures that the quantity ranges from zero to unity.
Entanglement
A 2-qubits pure state can be written (using Schmidt decomposition) as , where are the bases of respectively, and . Its density matrix is . The degree in which it is entangled is related to the purity of the states of its subsystems, , and similarly for (see partial trace). If this initial state is separable (i.e. there's only a single ), then are both pure. Otherwise, this state is entangled and are both mixed. For example, if which is a maximally entangled state, then are both completely mixed.
For 2-qubits (pure or mixed) states, the Schmidt number (number of Schmidt coefficients) is at most 2. Using this and Peres–Horodecki criterion (for 2-qubits), a state is entangled if its partial transpose has at least one negative eigenvalue. Using the Schmidt coefficients from above, the negative eigenvalue is . The negativity of this eigenvalue is also used as a measure of entanglement – the state is more entangled as this eigenvalue is more negative (up to for Bell states). For the state of subsystem (similarly for ), it holds that:
And the purity is .
One can see that the more entangled the composite state is (i.e. more negative), the less pure the subsystem state.
Inverse Participation Ratio (IPR)
In the context of localization, a quantity closely related to the purity, the so-called inverse participation ratio (IPR) turns out to be useful. It is defined as the integral (or sum for finite system size) over the square of the density in some space, e.g., real space, momentum space, or even phase space, where the densities would be the square of the real space wave function , the square of the momentum space wave function , or some phase space density like the Husimi distribution, respectively.
The smallest value of the IPR corresponds to a fully delocalized state, for a system of size , where the IPR yields . Values of the IPR close to 1 correspond to localized states (pure states in the analogy), as can be seen with the perfectly localized state , where the IPR yields . In one dimension IPR is directly proportional to the inverse of the localization length, i.e., the size of the region over which a state is localized. Localized and delocalized (extended) states in the framework of condensed matter physics then correspond to insulating and metallic states, respectively, if one imagines an electron on a lattice not being able to move in the crystal (localized wave function, IPR is close to one) or being able to move (extended state, IPR is close to zero).
In the context of localization, it is often not necessary to know the wave function itself; it often suffices to know the localization properties. This is why the IPR is useful in this context. The IPR basically takes the full information about a quantum system (the wave function; for a -dimensional Hilbert space one would have to store values, the components of the wave function) and compresses it into one single number that then only contains some information about the localization properties of the state. Even though these two examples of a perfectly localized and a perfectly delocalized state were only shown for the real space wave function and correspondingly for the real space IPR, one could obviously extend the idea to momentum space and even phase space; the IPR then gives some information about the localization in the space at consideration, e.g. a plane wave would be strongly delocalized in real space, but its Fourier transform then is strongly localized, so here the real space IPR would be close to zero and the momentum space IPR would be close to one.
References
Quantum mechanics | Purity (quantum mechanics) | Physics | 1,430 |
3,366,108 | https://en.wikipedia.org/wiki/Correlated%20equilibrium | In game theory, a correlated equilibrium is a solution concept that is more general than the well known Nash equilibrium. It was first discussed by mathematician Robert Aumann in 1974. The idea is that each player chooses their action according to their private observation of the value of the same public signal. A strategy assigns an action to every possible observation a player can make. If no player would want to deviate from their strategy (assuming the others also don't deviate), the distribution from which the signals are drawn is called a correlated equilibrium.
Formal definition
An -player strategic game is characterized by an action set and utility function for each player . When player chooses strategy and the remaining players choose a strategy profile described by the -tuple , then player 's utility is .
A strategy modification for player is a function . That is, tells player to modify his behavior by playing action when instructed to play .
Let be a countable probability space. For each player , let be his information partition, be 's posterior and let , assigning the same value to states in the same cell of 's information partition. Then is a correlated equilibrium of the strategic game if for every player and for every strategy modification :
In other words, is a correlated equilibrium if no player can improve his or her expected utility via a strategy modification.
An example
Consider the game of chicken pictured. In this game two individuals are challenging each other to a contest where each can either dare or chicken out. If one is going to dare, it is better for the other to chicken out. But if one is going to chicken out, it is better for the other to dare. This leads to an interesting situation where each wants to dare, but only if the other might chicken out.
In this game, there are three Nash equilibria. The two pure strategy Nash equilibria are (D, C) and (C, D). There is also a mixed strategy equilibrium where both players chicken out with probability 2/3.
Now consider a third party (or some natural event) that draws one of three cards labeled: (C, C), (D, C), and (C, D), with the same probability, i.e. probability 1/3 for each card. After drawing the card the third party informs the players of the strategy assigned to them on the card (but not the strategy assigned to their opponent). Suppose a player is assigned D, they would not want to deviate supposing the other player played their assigned strategy since they will get 7 (the highest payoff possible). Suppose a player is assigned C. Then the other player will play C with probability 1/2 and D with probability 1/2. The expected utility of Daring is 7(1/2) + 0(1/2) = 3.5 and the expected utility of chickening out is 2(1/2) + 6(1/2) = 4. So, the player would prefer chickening out.
Since neither player has an incentive to deviate, this is a correlated equilibrium. The expected payoff for this equilibrium is 7(1/3) + 2(1/3) + 6(1/3) = 5 which is higher than the expected payoff of the mixed strategy Nash equilibrium.
The following correlated equilibrium has an even higher payoff to both players: Recommend (C, C) with probability 1/2, and (D, C) and (C, D) with probability 1/4 each.
Then when a player is recommended to play C, they know that the other player will play D with (conditional) probability 1/3 and C with probability 2/3, and gets expected payoff 14/3, which is equal to (not less than) the expected payoff when they play D. In this correlated equilibrium, both players get 5.25 in expectation. It can be shown that this is the correlated equilibrium with maximal sum of expected payoffs to the two players.
Learning correlated equilibria
One of the advantages of correlated equilibria is that they are computationally less expensive than Nash equilibria. This can be captured by the fact that computing a correlated equilibrium only requires solving a linear program whereas solving a Nash equilibrium requires finding its fixed point completely. Another way of seeing this is that it is possible for two players to respond to each other's historical plays of a game and end up converging to a correlated equilibrium.
References
Sources
Fudenberg, Drew and Jean Tirole (1991) Game Theory, MIT Press, 1991,
. An 88-page mathematical introduction; see Section 3.5. Free online at many universities.
Osborne, Martin J. and Ariel Rubinstein (1994). A Course in Game Theory, MIT Press. (a modern introduction at the graduate level)
. A comprehensive reference from a computational perspective; see Sections 3.4.5 and 4.6. Downloadable free online.
Éva Tardos (2004) Class notes from Algorithmic game theory (note an important typo)
Iskander Karibzhanov. MATLAB code to plot the set of correlated equilibria in a two player normal form game
Noam Nisan (2005) Lecture notes from the course Topics on the border of Economics and Computation (lowercase u should be replaced by u_i)
Game theory equilibrium concepts | Correlated equilibrium | Mathematics | 1,096 |
68,717,905 | https://en.wikipedia.org/wiki/List%20of%20Art%20Deco%20architecture%20in%20Asia | This is a list of buildings that are examples of Art Deco in Asia:
Cambodia
Central Market (Phsar Thom Thmei), Phnom Penh, Phnom Penh, 1937
Central Market, Battambang
Royal railway station, Phnom Penh, 1932
China
Guangzhou
source: 广州市各级文物保护单位列表, 广州市历史建筑列表
Baoyuan Zhongyue No. 25(宝源中约25号民居), Guangzhou
, Guangzhou, construction halted in 1938 due to Japanese invasion, topped out in 1958
Donggao Yiheng Road No. 3 (东皋一横路3号民居), Guangzhou
, Guangzhou, 1937
Enning Road No. 46-54 (恩宁路46~54号骑楼), Guangzhou
Fok Zi Ting Mansion (霍芝庭公馆旧址), Guangzhou
Haizhu Nan Road No. 152 (海珠南路152号骑楼), Guangzhou
Jianglan Road No. 102 (桨栏路102号), Guangzhou
Ng Lou (梧庐), Guangzhou
Oi Kwan Hotel, Guangzhou, 1937
Renmin Road No. 33 (人民南路33号骑楼), Guangzhou
Nanjing
source: 南京市境内的江苏省文物保护单位列表
, Nanjing, 1929
, Nanjing, 1933
, Nanjing, 1935
, Nanjing, 1937
, Nanjing, 1933
Northeastern Provinces
, Changchun, 1938
Dalian Intermediate people's court, Former Kwantung Regional Court Building (大连市中级人民法院,原关东厅地方法院旧址）), Dalian, 1930
Dalian Public Security Bureau, Former Kwantung Police Bureau Building (大连市公安局,原关东厅警察署), Dalian, 1930
, Changchun, 1935
Former Dalian Broadcasting Center (大连中央放送局旧址), Dalian 1925
, Changchun, 1936
, Shenyang, 1921
Harbin International Hotel (哈尔滨国际饭店), Harbin, 1937
Qingdao
source: 青岛中山路近代建筑
, Qingdao, 1934
, Qingdao, 1931
, Qingdao, 1932
, Qingdao, 1934
, Qingdao, 1933
, Qingdao, 1934
, Qingdao, 1934
, Qingdao, 1936
, Qingdao, 1924
Pei Mansion, Shanghai, 1934
Shanghai
source:
, Shanghai, 1941
Avenue Apartments, Shanghai, 1932
Bank of China Building, Shanghai, Shanghai, 1937
Bank of Shanghai/Shangha Federation of Trade Unions (formerly the China Bank of Communications), Shanghai, 1949
Bank of Taiwan Building, Shanghai, 1924
Broadway Mansions, Shanghai, 1935
, Shanghai, 1932
, Shanghai, 1926
, Shanghai, 1936
Chinese YMCA, Shanghai, 1934
Defense of Sihang Warehouse, Shanghai, 1931
Denis Apartments, Shanghai, 1928
Dubail Apartments, Shanghai, 1931
Dufour Apartments, Shanghai, 1939
Embankment Building, Shanghai, 1932
Empire Mansions, Shanghai, 1931
Engineering Building at the Xuhui campus – Jiao Tong University, Shanghai, 1932
Eye and ENT Hospital of Fudan University, Shanghai, 1934
Fuyou Road Mosque, Shanghai, 1936
Gascogne Apartments, Shanghai, 1935
, Shanghai, 1932
Grand Cinema, Shanghai, 1933
Green House/Woo Villa (Laszlo Hudec, now the Urban Design and Planning Institute), Shanghai, 1938
Hamilton House, Shanghai, 1931
Hengshan Picardie Hotel, Shanghai, 1934
Huaihai Lu, Avenue Joffre, Shanghai
Institut Pasteur of Shanghai (formerly Musee Heude), Shanghai, 1930
Jiangwan Sports Center (stadium, natatorium), Shanghai, 1934
Jinjiang Hotel (former Cathay Mansion, 1929 and Grosvenor House, 1934), Shanghai
, Shanghai, 1936
, Shanghai, 1941
Medhurst Apartments, Shanghai, 1934
New Asia Hotel, Hongkou, Shanghai, 1934
Paramount (Shanghai), Shanghai, 1933
Park Hotel, Shanghai, 1934)
Peace Hotel (Part of The Bund, Palmer & Turner), Shanghai, 1929
Rainbow Apartments, Shanghai
Renji Hospital (formerly Lester Chinese Hospital), Shanghai, 1932
Rockbund Art Museum, Shanghai, China, 1933
Stellar International Cineplex, Shanghai, 1932
Villas Hotel, Shanghai, 1930s
Washington Apartments, Shanghai, 1928
Wheelock and Co. Sichuan Mansion, Shanghai, 1943
Wukang Mansion/Normandie Apartments, Shanghai, 1924
Tianjin
source:, 天津市文物保护单位, 天津市历史风貌建筑列表
, Tianjin, 1934
, Tianjin, 1939
, Tianjin, 1940
, Tianjin, 1933
, Tianjin, 1938
, Tianjin, 1937
, Tianjin, 1926
, Tianjin, 1940
, Tianjin, 1934
Victoria Building/, Tianjin, 1940
Wuhan
source: 武汉市优秀历史建筑列表
Central Trust of China Building (中央信托局汉口分局), Wuhan, 1936
Da Fu Bank Building (大孚银行), Wuhan, 1936
Juxingcheng Bank Building (聚兴诚银行), Wuhan, 1935
National Industrial Bank of China Building (中国实业银行), Wuhan, 1936
Si Ming Bank Building (四明银行), Wuhan, 1936
Other cities
, Ningbo, 1930
Former East Asia Development Board Liaison Office (兴亚院厦门联络部旧址), occupied on the former Huang Zhencheng residence, Xiamen, 1930
Hong Kong
Bank of China Building, Hong Kong, 1951
The Peninsula Hong Kong, Hong Kong, 1928
Yau Ma Tei Theatre, Hong Kong, 1930
India
Ahmedabad Town Hall
Electricity House - Vijali Ghar, Ahmedabad, Gujarat
The Imperial Hotel, New Delhi, 1931
Magen Avraham Synagogue, Ahmedabad, Gujarat, 1934
Prabhat Talkies, Mangalore,
Rajeshwari Theatre - Konankunte, Kon, Bangalore, Karnataka
Umaid Bhawan Palace indoor pool, Jaipur, 1928–1943
Chennai
Andhra Insurance Buildings, Chennai, 1940
Casino Theatre, Chennai, 1941
Catholic Centre, Chennai, 1951
Dare House (EID Parry Building), Chennai, 1940
Kamadhenu Theatre, Chennai, 1945
Kasturi Buildings (The Hindu), Chennai, 1939
Oriental Buildings, Chennai, 1935
Taj Connemara, Chennai, 1854, 1937
Mumbai
source:
Eros Cinema, Mumbai, 1935
Government Law College, Mumbai, 1938
Indian Merchant's Chamber building, Mumbai, 1939
Kapadia Chambers apartments, Mumbai
Metro Cinema, Mumbai, 1938
N.M. Petit Fasli Agiary, Mumbai, 1939
New Empire Cinema, Mumbai, 1908, 1948
New India Assurance Building, Mumbai, 1936
Regal Cinema, Mumbai, 1933
Shri Ganesh Krupa, Shivaji Park, Mumbai
Taraporewala Aquarium, Mumbai, 1951
United Building, Mumbai
Indonesia
Apotheek Rathkamp, Surabaya, East Java, 1930
Art council building (formerly Societeit De Harmonie), Makassar, South Sulawesi, 1910
Asy-Syuro Mosque, Garut, West Java, 1936
Balai Pertemuan, Palembang, South Sumatra, 1920s
Bank Mandiri office at Lapangan Merdeka, Medan, North Sumatra, 1929
Banjarbaru City Hall, Banjarbaru, South Kalimantan, 1924
Banjarmasin Cathedral, Banjarmasin, South Kalimantan, 1931
Birao Building, Tegal, Central Java, 1913
BKS PPS (Badan Kerja-sama Perusahaan Perkebunan Sumatera), (Sumatra Planters Association), Medan, North Sumatra, 1918
Borsumy Heritage (formerly Borneo Sumatra Handel Maatschappij), Semarang, Central Java, 1939
Cigar Building, Surabaya, East Java, 1916
Cirebon City Hall, Cirebon, West Java, 1927
Cirebon railway station, Cirebon, West Java, 1912
Gedung BAT (Formerly British American Tobacco regional headquarters), Cirebon, West Java, 1924
Gedung Bundar, Magelang, Central Java, 1934
Gedung Borsumij, Surabaya, East Java, 1930s
Gedung Internatio, Surabaya, East Java, 1931
Gedung Jiwarasya, Semarang, Central Java, 1916
Gedung Siola, Surabaya, East Java, 1923
Gedung PTPN XI, Surabaya, East Java, 1921
Gedung Juang Tambun, Bekasi, West Java, 1925
GKJ Gondokusuman, Yogyakarta special region, 1913
GPIB Maranatha, Pangkalpinang, Bangka Belitung Islands, 1927
GPIB Immanuel Surabaya, East Java, 1924
Hotel Majapahit, Surabaya, East Java, 1930 (lobby extension)
HKBP Sudirman Medan, Medan, North Sumatra, 1912
Ijen Cathedral, Malang, East Java, 1934
Inna Bali Hotel, Bali, 1927
Immanuel Protestant Church (formerly Nederlandse Hervormde Kerk), Medan, North Sumatra, 1921
Jagir Dam, Surabaya, East Java, 1923
Kantor Pos Besar, Surabaya, East Java, 1928
Kereta Api (Persero) Divisi Regional I Sumatera Utara building, Medan, North Sumatra, 1918
Kolese Santo Yusup (formerly The Neutrale Lagere School), Malang, East Java, 1930s
Lawang Sewu, Semarang, Central Java, 1919
Madiun City Hall, Madiun, East Java, 1930
Mandala Bakti Museum (formerly Raad van Justitie), Semarang, Central Java, 1930
Malang City Hall, Malang, East Java, 1929
Medan Cathedral, Medan, North Sumatra, 1928
Medan Railway Station, Medan, North Sumatra, 1937
Mulawarman Museum, Tenggarong, East Kalimantan, 1936
Official Residence of the Governor of South Sulawesi, Makassar, South Sulawesi, 1935
Old Padang City hall, Padang, West Sumatra, 1936
Olympic Hotel, Surabaya, East Java, 1955
Palembang Mayoral Office, Palembang, South Sumatra, 1931
Former PELNI office (now RAYNOX Restaurant and Bar), Semarang, Central Java, 1917
Pers Perjuangan monument, Surabaya, East Java, 1925
Post Office, Medan, North Sumatra, 1911
Praoe Lajar cigarette factory, Semarang, Central Java, 1910s
Puri Gedeh, Semarang, Central Java, 1925
Regional Chief Economist (RCE) Center, Malang, East Java, 1936
Sacred Heart of Jesus church, Banda Aceh, Aceh, 1926
Siantar railway station, Pematangsiantar, North Sumatra, 1916
Stella Maris Hospital, Makassar, South Sulawesi, 1937
St. Anthony's church Kotabaru, Yogyakarta Special region, 1926
St. Elisabeth's Hospital, Medan, North Sumatra, 1930
St. Joseph's church, Ambarawa, Central Java, 1924
Tip Top Restaurant, Medan, North Sumatra, 1934
Yogyakarta railway station, Yogyakarta Special region, 1920 (current facade)
Former Varekamp & Co. bookstore and printers, Medan, North Sumatra
Zebaoth Church, Bogor, West Java, 1920
Bandung
Bandung railway station, Bandung, West Java, 1928
Bank BJB Syariah, Bandung, West Java
Bank Pacific, Bandung, West Java, 1925
Bio Farma building, Bandung, West Java, 1926
Bioscoop Elita, Bandung, West Java
Bioscoop Dian, Bandung, West Java
Centre Point (formerly Naessens & Co. music equipment store), Bandung, West Java, 1925
, Bandung, West Java
Gedung Gas Negara, Bandung, West Java, 1919
Gedung Rumentang Siang, Bandung, West Java, 1935
Gedung Sate, Bandung, West Java, 1924
GPIB Bethel, Bethel Protestant Church, Bandung, West Java, 1924
GPIB Maranatha, Maranatha Protestant Church, Bandung, West Java, 1926
(now Prama Grand Preanger), Bandung, West Java, 1929
Het Paleis van de Legercommandant, (Kodam III Siliwangi) Bandung, West Java, 1918
Hotel Swarha, Bandung, West Java, 1935
Kantor Pos Besar Bandung, Bandung, West Java, 1928
Kologdam Building, Bandung, West Java, 1920
Merdeka Building, Bandung, West Java, 1926
Moh. Toha building, Bandung, West Java, 1919
Museum Geologi, Bandung, West Java, 1928
New Majestic, Bandung, West Java, 1924
NIROM Radio building, Bandung, West Java, 1925
Savoy Homann Hotel, (Designed by Albert Aalbers), Bandung, West Java, 1939
Villa Isola, (Bumi Silliwangi, Designed by C.P. Wolff Schoemaker), Bandung, West Java, 1932
Villa Tiga Warna, Bandung, West Java, 1937
Warenhuis De Vries, Bandung, West Java, 1909
Jakarta
Asuransi Jasa Indonesia building (formerly the West Java Handel Society), Jakarta, 1920
Antara Building, Jakarta, 1920
Athena Discotheque, Jakarta, 1927
Bank Mandiri Office – Pintu Besar branch (formerly Nederlandsch-Indische Escompto Maatschappij), Jakarta, 1920
Bank Mandiri – Jakarta-Kota branch (formerly Nederlandsch-Indische Handelsbank, Binnen Nieuwpoortstraat), Jakarta, 1940
Bank Mandiri Office in the Pertamina headquarter complex, Jakarta, 1938
Bank Tabungan Negara Office, Jakarta, 1938 (renovated to its current facade)
BP7 Building (formerly the Volksraad building), Jakarta, 1927
Building at Jl. Kunir no. 2 (formerly Geo Wehry Jakarta), Jakarta, 1928
Cikini Post Office, Jakarta, 1920s
Cipto Mangunkusumo General Hospital, Jakarta, 1926
Department of Defense and Security main building (formerly Rechts Hogeschool), Jakarta, 1924
Department of Energy and Mineral Resources main building (formerly Batavia Police Headquarter), Jakarta, 1925
Eijkman Institute for Molecular Biology, Jakarta, 1916
Filateli Jakarta, Jakarta, 1913
GKI Kwitang, Jakarta, 1924
GKI Pinangsia, Jakarta, 1952
Hotel des Galeries, Jakarta, 1914
Jakarta Kota railway station, Jakarta, 1928
Jasindo building, (formerly West Java Handel Maatschappij), Jakarta, 1920
Kota Post Office, Jakarta, 1929
Koinonia Church, Jakarta, 1916 (current facade)
Kunstkring Art Gallery, Jakarta, 1914
Mandiri Museum, Jakarta, 1933
Main building of Medical Faculty of the University of Indonesia, Jakarta, 1926
Manggarai railway station, Jakarta, 1918
Mausoleum O. G. Khouw, Jakarta, 1927
Ministry of National Development Planning building, Jakarta, 1925
Former Malacca Gallery at Jalan Malaka, Jakarta, 1923
Metropole Jakarta, Jakarta, 1932–1949
National Committee on Sea Transportation Safety, Ministry of Transportation Building, Jakarta, 1918
Peruri Office, Jakarta, 1920s
Pniel Church (Gereja Ayam), Jakarta, 1915
Santa Maria school (Formerly Koningin Emma School), Jakarta, 1911
St. Joseph's Church, Matraman, Jakarta, 1909 or 1924
St. Paul's Church, Jakarta, Jakarta, 1936
St. Theresia's Church, Jakarta, 1934
The Hermitage Hotel, Menteng, Jakarta, 1924
Toko Tio Tek Hong, Jakarta, 1916
Tanjung Priuk railway station, Jakarta, 1925
Iran
College of Engineering, University of Tehran, Tehran, 1942
Ministry of Justice, Tehran, 1930s
National Bank at the Bazaar, Tehran
Ramsar Hotel, Ramsar, Mazandaran, 1933
School for Orphans, Tehran
Tabriz Railway Station, Tabriz, 1916, 1958
Israel
Alhambra Cinema, Jaffa, 1937
British War Cemetery, Jerusalem, 1927
Generali Building, Jerusalem
Great Synagogue, Tel Aviv, 1926 (eclectic with Art Deco elements)
Gymnasia Rehavia high school, Rehavia, Jerusalem, 1928
Herzl Street 11, Tel Aviv
, now of Banking and Tel Aviv Nostalgia, Tel Aviv, 1909, 1924
Jerusalem International YMCA, Jerusalem, 1933
Jewish Agency Headquarters, Rehavia, Jerusalem, 1929
Levant Fair grounds, Tel Aviv, 1923–1936
, Tel Aviv, 1930
Old City Hall, Tel Aviv, 1924
Palm Tree House, Tel Aviv, 1922
former Preservation Building, Herzl Street, Tel Aviv, 1930s
, now Israel Electric Corporation building, Tel Aviv, 1923
Reading Power Station, Tel Aviv, 1938
Rehavia neighborhood, Jerusalem, 1924
, Tel Aviv, 1931
Villa Salameh, now Belgian Consulate, Jerusalem, 1930
Japan
(Ichikyunachi Building) Kyoto, 1928
Aimoto Power Station, Kurobe
store, Osaka, 1933
former Japanese National Railways Kyushu Area Headquarters and former Mitsui & Co. branch, Moji-ku, Kitakyūshū, 1937
former JR Kyushu Northern Kyushu Area Headquarters, Moji-ku, Kitakyūshū, 1935
Hikawa Maru ship, Yokohama, 1929
Hiroshima Peace Memorial, Hiroshima, 1915
Hotel New Grand, Yokohama, 1927
Imperial Hotel, Chiyoda, Tokyo, 1923
Isetan Shinjuku main store, Shinjuku, Tokyo, 1933
Kangawa Prefectural Building, Yokohama, 1928
, Kyoto, 1937
Kansai Japanese-French Academy, Sakyo-ku, Kyoto, 1936
Kobe City Archives (formerly Ikenaga Museum of Art), Kobe, 1938
, Kobe, 1927
Kōshien Hotel/Kōshien Kaikan, Mukogawa Women's University, Nishinomiya, Hyōgo, 1930
(formerly Nozawaya department store), Kanagawa, 1928
Osaka City University Building No. 1, Osaka, 1934
Osaka Security Exchange, Osaka, 1949
, Chuo-ku, Osaka, 1926
, Chuoku, Osaka City, 1923
, Mitarai, Kure, 1937
, Nada-ku, Kobe, 1932
Toyama Prefectural Office Building, Toyama, 1935
Toyosato Elementary School old building and auditorium, Shiga, 1937
, Yokohama, 1936
Yokohama Customs Building, Yokohama, 1934
Yokohama Port Opening Memorial Hall, Yokohama, 1937
Tokyo
Asakusa Station/Matsuya department store, Taito, Tokyo, 1931
Ginza Wako, Tokyo, 1923
, Chiyoda-ku, Tokyo, 1930
(Yamanoue Hotel), Chiyoda, Tokyo, 1953
Lion Beer Hall, Tokyo, 1934
Mitsukoshi Nihonbashi, Tokyo, 1925
Mitsukoshimae Station passageway, Tokyo, 1932
National Diet Building, Chiyoda, Tokyo, 1936
St. Luke's International Hospital, Tsukiji, Chuo, Tokyo, 1902, 1924
Tokiwadai Photo Studio, Edo-Tokyo Open Air Architectural Museum, Tokyo, 1937
Tokyo Metropolitan Teien Art Museum, (Prince Asaka Residence), Tokyo, 1933
Tosho Bunko Library, Kita, Tokyo
Laos
Lao Chaleune Theatre, Savannakhet, 1930s
Siensavan Cinema, Wat Visoun, Luang Prabang
Soumpholphakdy House, Savannakhet, 1926
Lebanon
Cinema Opera and Ezzeddine Building, Beirut, 1932
Corm Building and Gardens (Ford Motor Company's Middle East headquarters), Beirut, 1929
National Museum of Beirut, Beirut, 1937
Nejme Square/Place de l'Étoile (including the Abed Clock Tower, Lebanese Parliament building), Beirut
Macau
, Macau, 1952
Teatro Apollo (now Esprit store), Macau, 1935
Red Market, Macau, 1936
, Macau, 1937
Malaysia
Capitol Theatre, Jalan Bendahara, Malacca, 1936
KTM Museum (former Johor Bahru railway station), Johor, 1909
Lido Cinema, Kota Bharu, Kelantan
Lido Theatre, Dato Onn Jafar, Ipoh, 1957
Majestic Theater, Jalan Chamberlain Hulu, Ipoh, 1940s
Ruby Cinema, Ipoh
Sultan Sulaiman Mosque, Selangor, 1934
Sungai Petani clock tower, Sungai Petani, Kedah, 1936
George Town, Penang
City Rio Cafe, George Town, Penang
Georgetown Cinema, George Town,Penang
India House, George Town, Penang
Maison De Poupée (former Garage), George Town, Penang
Odeon Cinema, George Town, Penang
Penang Masonic Temple, George Town,Penang, 1927
Standard Chartered Bank, George Town,Penang
The Star Theatre, George Town,Penang
Kuala Lumpur
Capitol Theatre, Kuala Lumpur, 1947
Central Market, Kuala Lumpur, 1937
Coliseum Theatre, Kuala Lumpur, 1920
Lee Rubber Building, High Street, Kuala Lumpur, 1930
Market Square clock tower (behind Central Market), Kuala Lumpur, 1937
Odeon Cinema, Jalan Tuanku Abdul Rahman, Kuala Lumpur, 1936
Old OCBC Building, Kuala Lumpur, 1938
Oriental Building, Kuala Lumpur, 1937
Pavilion Cinema, Kuala Lumpur
Perpustakaan Kanak-kanak children's library, Kuala Lumpur
Rubber Research Institute, Jalan Ampang, Kuala Lumpur, 1935
Wisma Ekran (Central Market), Kuala Lumpur, 1888, 1937
Myanmar
Aung Mingala Cinema, Dawei, Tanintharyi Region
City Lite Cinema Hall, Myitkyina, Kachin State, 1951
Hla Thiri Cinema, Minbu, Magwe Division, 1959
Kemarat Cinema, Kengtung, Shan State
King's Cinema, Mawlamyine, Mon State
Min Thiha Cinema, Katha, Sagaing Region
Myoe Gon Yaung Cinema, Mandalay, Mandalay Region
Myoma Cinema, Pyin Oo Lwin, Mandalay Region
San Thit Cinema, Ma-ubin, Irrawady Region, 1963
Sein Mit Tar, Hsipaw, Shan Statem 1964
Shwe Hintha Cinema, Bago, Bago Region
Starlight Cinema, Bhamo, Khachin State, 1959
Tun Thiri Cinema, Pyay, Bago Region
Win Cinema, Taungoo, Bago Region, 1961
Win Lite Cinema, Mandalay, Mandalay Region
Yazuna Cinema, Pyin Oo Lwin, Mandalay Region
Za Bue De Par Cinema, Bhamo, Kachin State
Yangon
Agricultural Development Bank, Yangon, 1930
Bayint Cinema (King Cinema), Yangon
Hsuhtupan Cinema, Yangon
Myanma Economic Bank No. 2, (formerly the Chartered Bank), Yangon, 1941
Myanma Port Authority, Yangon
Myoma and Shwe Gon Cinemas, Yangon, late 1940s
Nay Pyi Daw Cinema Hall, Yangon
Su Htoo Pan Cinema, Yangon
Thakin Kodaw Hmaing Museum, Yangon, 1966
Thamada Cinema, Yangon
Thwin Cinema, Yangon
Wayiza Cinema, Yangon
Yadana Pon Cinema, Yangon
Pakistan
House of Syed Abul A'la Maududi, Lahore
Qamar House, Karachi, 1951
Philippines
Antipolo Cathedral, Antipolo, Rizal, 1954
Bauan Municipal Hall, Juan M. Arellano, Bauan, Batangas, 1930
City Hall, Surigao City, Surigao del Norte
Daku Balay, (Salvador Cinco), Bacolod City, Negros Occidental, 1936
Dr. Jose Corteza Locsin Ancestral House, Silay, Negros Occidental, 1930s
Far Eastern University Campus, Sampaloc, Manila, 1940s
Hotel Tiffany, Laoag, Ilocos Norte
Iglesia Filipina Independiente, Laoag, Ilocos Norte
Immaculate Conception Cathedral, Urdaneta, Pangasinan
Misamis Occidental Provincial Capitol, Oroquieta, Misamis Occidental, 1935
Novo Department Store, Laoag, Ilocos Norte
Provincial Capitol, Surigao City, Surigao del Norte
Roman Catholic Church, Oroquieta, Misamis Occidental
Tacloban City Hall, Tacloban, Leyte
Tanauan Museum (old municipal building), Tanauan, Leyte, 1920s
La Union Provincial Capitol, San Fernando, La Union
Vi-Car Building, Dagupan, Pangasinan
Benguet Province
Baguio Colleges, Baguio, Benguet
Bayanihan Hotel and Commercial Building, Baguio, Benguet
Benguet Auto Lines Station (Pablo Antonio), Baguio, Benguet
Hotel City Lunch, Baguio, Benguet
Iglesia ni Cristo Lokal ng Baguio, Baguio, 1954
Philippine Military Academy (PMA) Melchor Hall, Baguio, Benguet, 1950
Pines Theater, Fernando H. Ocampo, Baguio, Benguet, 1939
Philippine National Bank (PNB), Baguio, Baguio, Benguet
Plaza Theater, Baguio, Benguet
Session Road buildings Baguio, Benguet
Session Theater, (Fernando Ocampo), Baguio, Benguet
Sunshine Bakery, Baguio, Benguet
Bulacan Province
Bulacan Provincial Capitol, Malolos, Bulacan, 1930
Calumpit Municipal Hall, Calumpit, Bulacan
Dr. Luis Santos Ancestral House, Malolos, Bulacan, 1933
Ipo Dam Tower, Norzagaray, Bulacan, 1935
Malolos City Hall, Malolos, Bulacan
Camarines Sur Province
Alex Theater, Naga, Camarines Sur
Carmelite Chapel, Naga, Camarines Sur
Jaucian House, Libmanan, Camarines Sur, 1926
Morales Ruins, Libmanan, Camarines Sur, 1937
Nacieno House, Libmanan, Camarines Sur
Cebu Province
Alliance française, Cebu City, Cebu
Cebu Provincial Capitol, (Juan M. Arellano), Cebu City, Cebu, 1938
Gotiaoco Building, Cebu City, Cebu
Lapulapu Monument, Lapu-Lapu City/Opon, Cebu, 1933(demolished)
Oriente Theater (Fernando Ocampo), Cebu City, Cebu
University of the Philippines Cebu administration building, Cebu City, Cebu
Manila
Afable Building, Manila, 1931
Aguinaldo's Building, Manila, 1931
Angela Apartments, (Fernando Ocampo), Manila, 1936
Astoria Building, Manila
Ateneo Auditorium, (Juan Nakpil), Manila, 1936
Avenue Theater, (Juan Nakpil), Manila (demolished)
Bautista-Nakpil Pylon in Manila North Cemetery, (Juan Nakpil), Santa Cruz, Manila
Bel-Air Apartments, (Pablo Antonio), Manila 1937
Bellevue Theater, Manila, 1930s
Benipayo Press building, Manila
Capitan Gonzaga Residence, (Pablo Antonio), Manila
Capitol Theater, (Juan Nakpil) Manila, 1935
Central Hotel, (Capitan Pepe Building, Juan Nakpil), Manila, 1938
Central Institute of Technology, Manila
Centro Escolar University, Manila
Chapel of the Crucified Christ, Saint Paul University Manila (Andrés Luna de San Pedro), Manila, 1927
Chapel of the Most Blessed Sacrament, De La Salle University (Tomás Mapúa), Manila, 1939
Chevrolet building, Romualdez Street, north of U.N. Avenue, Manila (demolished)
Cine Astor, Manila (demolished)
Coca-Cola Bottling Plant, (Gabler-Gumbert), Manila
Commercial building on Calle Santa Potenciana corner Calle Solana
Crystal Arcade, (Andrés Luna de San Pedro, 1932)(demolished)
De Ocampo Eye Clinic, Manila (demolished)
Elena Apartments, (Juan Nakpil), Manila, 1935 (demolished)
Ever Theater, Manila
Far Eastern University buildings and Auditorium, (Pablo Antonio), Manila, 1939–49
First United Building, (Andrés Luna de San Pedro), Manila, 1928
Forum Theatre, (Juan Nakpil), Manila, 1968
Francisco Villa Roman Foundation School, (Juan Nakpil), Malate, Manila
Gaiety Theater, (Juan Nakpil), Manila, 1935 (demolished)
G. Apacible Bridge, Manila
Go Lam Co Hardware & Plumbing Co. Building, Manila
Grand Theater, Manila (demolished)
Great Eastern Hotel, Manila (demolished)-This was the tallest art-deco hotel in the Philippines.
Hap Hong Building, Manila, 1938
Heacock Building, (Fernando Ocampo, Tomas Arguelles, and George Koster), Manila, 1938(demolished)
Hidalgo-Lim house, (Juan Nakpil), Manila, 1930
High Commissioner's Residence, 1940
Hotel Filipinas, (Chow King, Recto Ave. cor. Rizal Ave.), Manila
Ideal Theater, (Pablo Antonio), Manila, 1933 (demolished)
Ides O'Racca Building, Manila, 1935
Iglesia Unida Ecumenical Templo Central, Manila
Insular Life Building, (Fernando de la Cantera and William James Odom), Manila, 1930 (demolished)
Javellana house (Juan Nakpil), Manila (demolished)
L. R. Papa Pension, Manila
La Estrella del Norte building, (Savory Restaurant), Manila (demolished)
Lacson house (Juan Nakpil), Manila (demolished)
Laperal Apartments, Manila (demolished)
Life Theater, (Pablo Antonio), Manila, 1941
Lyric Theater (Pablo Antonio renovation), Manila, 1937 (demolished)
Manila Central University Administration and Pharmacy, Manila
Manila Hotel, (Andrés Luna de San Pedro, 1935 renovation)
Manila Jai Alai Building, (Welton Beckett, 1940) (demolished)
Manila Metropolitan Theater, (Juan M. Arellano), Manila, 1931
Manila Police District building, Manila
Manila Port Terminal Building, Manila, 1939
Manuel F. Tiaoqui Building, Santa Cruz, Manila
Marsman Building, (Port Authority Building, Juan Arellano), Manila, 1938
Mayflower Building, Manila, 1938
Meralco Building, (Juan Nakpil), Manila, 1936 (demolished)
Miramar Apartments (New Miramar Hotel), Manila, 1932
Myers Building, (Velco Building), Manila
Narcisa Building, Manila
National Teachers College, Manila
Orchid Garden Hotel, (Pablo Antonio), Manila, 1930
Pako Building, Manila, 1939
Paterno Building, (Fernando Ocampo), Manila, 1929
Philippine Business for Social Progress building, Manila
Philippine Christian University, Manila
Philippine Coast Guard Building, Manila
Pink house on Paris Street, Manila (demolished)
Quezon Bridge, Manila, 1939
Radio Theater, Manila, 1929 (demolished)
Ramon Roces Building, (Pablo Antonio), Manila
Rex Theater, Manila
Rizal Memorial Baseball Stadium, Manila, 1934
Rizal Memorial Coliseum, Manila, 1934
Rizal Memorial Sports Complex, Malate, Manila, 1934
Rizal Memorial Stadium, Manila, 1934
Saint Cecilia's Hall, St. Scholastica's College, (Andrés Luna de San Pedro), Manila, 1932
San Lazaro Racetrack, (Juan Nakpil), Manila (demolished)
Scala Theater, (Pablo Antonio), Manila
Scottish Rite Temple, Manila, 1930s
Singson Building, Manila
South Syquia Apartments, Manila
St. Paul United Methodist Church, Manila
State Theater, (Juan Nakpil), Manila, 1935 (demolished)
Syquia Building/Michel Apartments, (Francis Mandelbaum), Manila (demolished)-This was the tallest art-deco apartment building in the Philippines.
Times Theater, (Luis Araneta), Manila, 1939
Tivoli Theater, Manila (demolished)
U.S.T. Central Seminary, (Fernando H. Ocampo), Manila, 1933
U.S.T. Clinic, Cooperative, Gym, High School, Manila
U.S.T. Press building, Manila, 1950 (demolished)
U.P. University Theater, Manila (demolished)
University Club, (de la Cantera), Manila (demolished)
University of Santo Tomas Central Seminary Building, Manila, 1933
Uy Su Bin Building, Manila
Warehouse, Railroad St. corner 22nd St., Manila
Y.I.C. Building, Manila (demolished)
Yutivo Building, (Arthur Julius Nicolaus Gabler-Gumbert), Manila, 1922
YSS Laboratories building, Manila
Metro Manila
Baclaran Church, Parañaque, 1932
Balintawak Beer Brewery (demolished), Valenzuela
Biological Production Service building, Muntinlupa
Bonifacio Monument, Guillermo Tolentino, Caloocan, 1933
Cine Concepcion, (Pablo Antonio), Malabon, 1940 (demolished)
Clipper Hotel, Makati
Gomez Mansions, Pasay
Greendale Supermarket (Savemore), Marikina
Guardhouse south of Petron station, C-5, Barangay Ugong, Pasig, (demolished)
Hospital Español de Santiago, Makati, 1932 (demolished)
Iglesia Ni Cristo chapel (Locale of F. Manalo), San Juan, 1952
Iglesia ni Cristo Lokal ng Caloocan, Caloocan, 1953
Iglesia ni Cristo Lokal ng Pasay, Pasay, 1954
Iglesia ni Cristo Lokal ng Paco, Paco, Manila, 1957
Lambingan Bridge, San Juan
Manila Polo Club, (Pablo Antonio), Makati, 1950
Manila Sanitarium, (Adventist Medical Center Manila), Pasay, 1929
Mapúa Mansion, Pasay, 1930
Morosi Theater, Pasay (demolished)
Municipal Building, Makati
Nielson Field Tower, Makati, 1937
Santa Ana Racetrack, Makati (demolished)
Savoy Bistro, Makati
Syjuco Bel-air Apartments, Makati
University of Makati Stadium, Makati
Wack Wack Golf and Country Club, Mandaluyong, 1930
White Cross Orphanage (Pablo Antonio), San Juan, 1938
Nueva Ecija
Iglesia ni Cristo Lokal ng Cabanatuan, Cabanatuan, Nueva Ecija, 1957
Mindanao island
Court of First Instance and City Jail, (demolished), Davao City
Dakudao Building, Davao City
Garcia Building, Davao City
PNB building, Davao City
Provincial Capitol, Cagayan de Oro
PTA Stadium, Davao City
Panay island
Angelicum School Iloilo, Jaro, Iloilo City
Banco Nacional de las Filipinas, Iloilo City
Cementerio Catolico de Molo, Molo, Iloilo City
Iloilo Central Market, Iloilo City
Jaro Municipal Hall, (Juan M. Arellano), Jaro, Iloilo City, 1935
Ledesma Mansion, Jaro, Iloilo City
Lizares Mansion, Jaro, Iloilo City, 1937
Lopez Boat House, (Fernando Ocampo) Jaro, Iloilo City, 1936
Lopez Heritage House (Nelly's Gardens Mansion), Jaro, Iloilo City, 1928
Pablo Dulalia Building, Iloilo City, 1932
Philippine Tuberculosis Society Building, Iloilo City
S. Villanueva Building, Iloilo City
Salvador Building, Iloilo City
YMCA, Iloilo City
Quezon City
19 June Bridge, Quezon City
AFP GHQ Building, Quezon City
AFP Medical Center, Quezon City
Balara Filters Plant, Quezon City
Camp Aguinaldo guardhouses, Quezon City
Christ the King Mission Seminary, Quezon City
Manahan Building, Quezon City
Mira-Nila House
Mount Carmel Church, Quezon City
National Cathedral of Saint Mary and Saint John, Quezon City
National Children's Hospital, Quezon City (demolished)
National Shrine of Our Lady of Lourdes, Quezon City
Quezon City General Hospital, Quezon City
Quezon Institute, (Juan Nakpil,), Quezon City, 1938
Quezon Memorial Circle (Federico Ilustre), Quezon City, This is the tallest art-deco structure in the Philippines.
Saint Joseph's College of Quezon City gateposts and fence, Quezon City
Sacred Heart Parish Kamuning, Quezon City
Santander Building, Quezon City
Santo Domingo Church, (Jose Maria Zaragosa), Quezon City
Siena College of Quezon City, Quezon City
Standard Photo Engraving Co. building, Quezon City
UERM, Quezon City
U.P. Quezon Hall (Juan Nakpil), Gonzales Hall (Nakpil), Palma Hall (Cesar Concio), Melchor Hall (Concio), Carillon Tower (Nakpil), Luna Parade Ground flagpole base, Molave Residence Hall, Quezon City
Veterans Memorial Medical Center guardhouse, Quezon City
Welcome Monument (Luciano V. Aquino), Quezon City, 1948
Quezon Province
Gala-Rodriguez Ancestral House (Juan Nakpil), Sariaya, Quezon, 1935
Municipal Hall, Tiaong, Quezon
Natalio Enriquez House (Andres Luna de San Pedro), Sariaya, Quezon
Quezon Provincial Capitol, (Juan M. Arellano), Lucena, Quezon, 1935
Sariaya Municipal Building, (Juan M. Arellano), Sariaya, Quezon, 1931
Singapore
source:
36 and 38 Armenian Street, Singapore
Asia Insurance Building, Singapore, 1958
Bank of China Building (Singapore), 1953
Capitol Theatre, Singapore, 1930
Clifford Pier, Collier Quay, Singapore, 1933
former Ford Factory, Bukit Timah, Singapore, 1942
Kallang Airport, Singapore, 1937
Majestic Theatre (formerly the Tien Yien Moh Toi Theatre), Chinatown, 1938
Murray Terrace, Singapore, 1929
Parkview Square, 2002
Rex Cinemas Mackenzie, 1964
Tanjong Pagar railway station, Tanjong Pagar, 1932
The Cathay, Singapore, 1937
The Great Madras, Little India, Singapore
Tiong Bahru housing estate, Bukit Merah Planning Area, 1920s
South Korea
source:
former Busan Meteorological Observatory, Busan, 1934
, Seoul, 1921
, Gwangju, 1927
former City Hall, Seoul, 1925
(formerly Daegu Medical College), Kyungpook National University, Daegu, 1933
, Seoul, 1923
former Ilseon Shipping Office, Incheon, 1930s
Kyungpook National University Hospital (the former Provincial Daegu Hospital, Daegu, 1928,
, Seoul, 1936
Seoul Metropolitan Council building, Seoul, 1925
, Gungwon-do, Hongcheon-gun Seosok-myeon, 1935
Sri Lanka
Deco on 44 Hotel, Lighthouse Street, Galle, 1930s
Galle Face Court, Galle Road, Colombo, 1930s
Imperial Theatre, Kurunegala
Kandy Railway Station, Kandy
Walker Sons and Company Building, Layden Bastian Road, Colombo
YMCA, Bristol Street, Colombo
Thailand
Laung Sitra Tapakarn's residence, Ratchaburi
New Chalerm Uthai Theater, Uthai Thani, early 1940s
O.K. Rama, Suphanburi
Phra Ram Ratchaniwet (Ban Puen Palace for King Chulalongkorn), Petchaburi, 1916
St. Josef Church, Ban Pong, Ratchaburi
Thahan Bok Theater, Lopburi, 1941
Wik Kru Thawee Theatre, Ratchaburi, 1958
Bangkok
Bangkok Railway Station (Hua Lamphong Station), Pathum Wan District, Bangkok, 1916
Democracy Monument, Bangkok, 1939
General Post Office, Bangkok, 1940
National Stadium, Pathum Wan District, Bangkok, 1937
Rajadamnern Stadium (Sanam Muay Rajadamnern boxing stadium), Bangkok, 1945
Rama I Road Yotse bridge-Kasat Suek bridge, Bangkok, 1929
The Royal Hotel
Sala Chalermkrung Royal Theatre, Bangkok, 1933
Thon Buri Railway station, Bangkok Noi District, Bangkok, 1950
Victory Monument, Ratchathewi District, 1942
The 1940s-era buildings along the middle section of Ratchadamnoen (Kingswalk) Avenue
Scala Cinema, Bangkok, 1969
Vietnam
Bach Mai Hospital (formerly René Robin Hospital), Hanoi, 1940
Banque de l'Indochine (now State Bank of Vietnam), Hanoi, 1930s
Clinique Building (former hospital), French Quarter, Hanoi, 1920s
Cửa Bắc Church, Hanoi, 1925, 1932
Da Lat Palace Hotel, Da Lat, 1922
Da Lat Railway Station, Da Lat, 1932, 1938
Domaine de Marie Catholic convent, Da Lat, 1940
Emperor Bao Dai's Summer Palace, Da Lat
Ho Chi Minh City Museum of Fine Arts, Ho Chi Minh, 1934
Hotel de l'Opera Hanoi, Hanoi
IDEO printing house, Hanoi
Ministry of Foreign Affairs, Hanoi, 1945
State Bank of Vietnam, Hanoi
See also
List of Art Deco architecture
Art Deco topics
Streamline Moderne architecture
References
Art Deco | List of Art Deco architecture in Asia | Engineering | 8,457 |
1,571,455 | https://en.wikipedia.org/wiki/HD%204208 | HD 4208 is a star with an orbiting exoplanetary companion in the southern constellation of Sculptor. It has a yellow hue with an apparent visual magnitude of 7.78, making it too dim to be visible to the naked eye. But with binoculars or small telescope it should be an easy target. This object is located at a distance of 111.6 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +57 km/s.
The star HD 4208 is named Cocibolca. The name was selected in the NameExoWorlds campaign by Nicaragua, during the 100th anniversary of the IAU. Cocibolca is the Nahuatl name for the Lake Nicaragua.
This is a G-type main-sequence star with a stellar classification of , where the suffix notation indicates underabundances of iron and carbyne in the spectrum. It is roughly 6.6 billion years old and is spinning with a projected rotational velocity of 4.4 km/s. The star has 86% of the Sun's mass and radius, and is radiating 71% of the Sun's luminosity from its photosphere at an effective temperature of 5,717 K.
In 2001, a planet was discovered orbiting the star by means of the radial velocity method. This body is orbiting from the host star with a period of and a low eccentricity of 0.042. The position of this planet near the star's habitable zone means that it will have a strong gravitational perturbation effect on any potential Earth-mass planet that may be orbiting within this region.
See also
HD 4203
HD 4308
List of extrasolar planets
References
G-type main-sequence stars
Planetary systems with one confirmed planet
Sculptor (constellation)
Durchmusterung objects
9024
004208
003479 | HD 4208 | Astronomy | 385 |
44,500,893 | https://en.wikipedia.org/wiki/SB-236057 | SB-236057 is a compound which is a potent and selective inverse agonist for the serotonin receptor 5-HT1B, acting especially at 5-HT1B autoreceptors on nerve terminals. It produces a rapid increase in serotonin levels in the brain, and was originally researched as a potential antidepressant. However subsequent research found that SB-236,057 also acts as a potent teratogen, producing severe musculoskeletal birth defects when rodents were exposed to it during pregnancy. This has made it of little use for research into its original applications, yet has made it useful for studying embryonic development instead.
See also
AR-A000002
GR-55562
GR-127935
SB-216641
References
5-HT1B antagonists
Teratogens
Oxadiazoles
Abandoned drugs | SB-236057 | Chemistry | 183 |
14,800,016 | https://en.wikipedia.org/wiki/Histone%20H3.1 | Histone H3.1 is a protein in humans that is encoded by the H3C1 gene.
Histones are basic nuclear proteins that are responsible for the nucleosome structure of the chromosomal fiber in eukaryotes. This structure consists of approximately 146 bp of DNA wrapped around a nucleosome, an octamer composed of pairs of each of the four core histones (H2A, H2B, H3, and H4). The chromatin fiber is further compacted through the interaction of a linker histone, H1, with the DNA between the nucleosomes to form higher order chromatin structures. This gene is intronless and encodes a member of the histone H3 family. Transcripts from this gene lack polyA tails; instead, they contain a palindromic termination element. This gene is found in the large histone gene cluster on chromosome 6p22-p21.3.
References
Further reading | Histone H3.1 | Chemistry | 207 |
56,531,421 | https://en.wikipedia.org/wiki/Temporal%20light%20artefacts | Temporal light artefacts (TLAs) are undesired effects in the visual perception of a human observer induced by temporal light modulations. Two well-known examples of such unwanted effects are flicker and stroboscopic effect. Flicker is a directly visible light modulation at relatively low frequencies (< 80 Hz) and small intensity modulation levels. Stroboscopic effect may become visible for a person when a moving object is illuminated by modulated light at somewhat higher frequencies (>80 Hz) and larger intensity variations.
Relevance
Various scientific committees have assessed the potential health, performance and safety-related aspects resulting from temporal light modulations. TLAs must be limited to certain levels to avoid annoyance due to the direct visibility by humans and to prevent potential health issues. After longer exposure, TLAs may reduce task performance and cause fatigue. Possible health effects for specific persons are photosensitive epileptic seizure, migraine and aggravation of autistic behavior. The incorrect perception of the motion of an object due to stroboscopic effect may be unacceptable in working environments with fast moving or rotating machinery.
Types
TLAs are generally unwanted effects that may be perceived by humans due to the fact that the light output of a lighting equipment varies with time. Different TLA phenomena, the associated terms and definitions and their visibility aspects are given in a technical note of CIE; see CIE TN 006:2016. In CIE TN 006:2016 three types of TLAs are distinguished:
Flicker refers to unacceptable (irritating) light variation of a light source that is perceived by an average person, either directly or via a reflecting surface ;
Stroboscopic effect is an unwanted effect which may become visible for an average person when a moving or rotating object is illuminated by a time-modulated light source;
Phantom array (or ghosting) may be perceived by an average person when making an eye saccade over a small light source having a periodic fluctuation, the light source is then perceived as a series of spatially extended light spots.
Further background and explanations on the different TLA phenomena are given in a recorded webinar "Is it all just flicker?". Models for the visibility of flicker and stroboscopic effect from the temporal behavior of luminous output of LEDs are in the doctoral thesis of Perz.
Root causes
The root cause of TLAs is the variation of the light intensity of lighting equipment. Important factors that can contribute and that determine the magnitude and type of light modulation of lighting equipment are:
Light source technology: LEDs do not intrinsically produce temporal modulation; they just reproduce the input current waveform very well, and any ripple in the current waveform is reproduced by a light ripple because LEDs have a fast response; therefore compared to conventional lighting technologies (incandescent, fluorescent), for LED lighting more variety in the TLA properties is seen.
Power source technology (driver, electrical ballast): Many types and topologies of LED drivers and electrical ballasts are applied; simpler electronics and limited or no buffer capacitors often result in larger residual current ripple and thus larger temporal light modulation.
Light regulation: Dimming technologies of either externally applied dimmers (incompatible dimmers) or internal light-level regulators may have a large impact.; the level of temporal light modulation generally increases at lower light levels.
Mains voltage fluctuations: Electrical mains voltage variations are caused by switching or varying loads of electrical apparatus connected to the mains network, or may be intentionally applied e.g. for power-line communication.
Visible light communication technologies: Intentional temporal light modulations like LiFi can be applied, e.g. for communication purposes; these additional TLMs may give rise to unwanted TLAs.
Metrics
Several simple metrics such as Modulation Depth, Flicker Index and Flicker Percentage are often used to assess the acceptability of flicker. None of these metrics are suitable to objectively assess the visibility and acceptability of TLAs by humans. Human perception of TLAs is impacted by various factors: modulation depth, frequency, wave shape and duty cycle.
More advanced metrics have been developed and validated to objectively assess the visibility of TLAs:
for flicker, the short-term flicker indicator PstLM,
for stroboscopic effect, the stroboscopic effect visibility measure SVM.
For flicker also two alternative measures are derived to measure its visibility, the Flicker Visibility Measure FVM and the Time domain Flicker Visibility Measure TFVM.
NOTE - The application of the SVM-metric is limited for human perception of stroboscopic effect in normal application environments (residential, office) where the speed of movement of persons and/or objects is limited. For phantom array effect no metric has been defined yet.
Measurement methods
Standardised test and measurement methods
Measurement of PstLM, and optionally testing effect of mains voltage fluctuations or dimming: see IEC TR 61547-1, edition 3;
Measurement of SVM, and optionally testing effect of dimming: see IEC TR 63158;
TLA: Test Methods and Guidance for Acceptance Criteria, see NEMA 77-2017;
Guidance on the measurement of temporal light modulation of light sources and lighting systems: see CIE TN 012
Recommended limits
Recommended limits for the TLA phenomena flicker and stroboscopic effect are in NEMA 77-2017 publication.
Improper use of cameras for TLA assessment
If smart-phone phone cameras, video cameras or film cameras are used in presence of temporally modulated light, a variety of artefacts may be seen on the picture or on the recording, e.g. vertical or horizontal banding with varying brightness (this category of unwanted effects is temporal light interference - TLI). However, the type of artefact depends very much on the camera technology and camera settings. Different camera's will show different artefacts depending on type of shutter, picture frame rate and on the mitigation measures taken in the camera. Apart from the possible variety of effects that can be seen, there is also a difference between what people perceive directly compared to what people perceive via a camera and display or monitor. Hence, usage of common cameras is not a valid and objective means to assess the potential TLA from lighting equipment.
See also
Temporal light effects
Temporal light interference
Flicker (light)
Stroboscopic effect (lighting)
Stroboscopic effect
References
Further reading
LightingEurope TLA position paper, LightingEurope Position Paper on Flicker and Stroboscopic Effect (Temporal Light Artefacts), September 2016;
NEMA TLA position paper, Temporal Light Artifacts (Flicker and Stroboscopic Effects), 15 June 2015;
ZVEI information paper, Temporal Light Artefacts – TLA, March 2017 (in German and English);
CIE Technical Note CIE TN 008:2017, Final Report CIE Stakeholder Workshop for Temporal Light Modulation Standards for Lighting Systems.
Lighting
Optical illusions | Temporal light artefacts | Physics | 1,402 |
10,285,600 | https://en.wikipedia.org/wiki/Oritavancin | Oritavancin, sold under the brand name Orbactiv (by Melinta Therapeutics) among others, is a semisynthetic glycopeptide antibiotic medication for the treatment of serious Gram-positive bacterial infections. Its chemical structure as a lipoglycopeptide is similar to vancomycin.
The U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have approved oritavancin for treatment of acute bacterial skin and skin structure infections.
Medical uses
Oritavancin is considered a long-lasting antibiotic due to its extended half-life (up to ), high protein binding capacity, and ability to penetrate tissues effectively. It binds strongly to plasma proteins (around 85%), resulting in prolonged release into surrounding tissues. Furthermore, oritavancin exhibits excellent tissue penetration and distribution throughout various sites, including skin structures, synovial fluid (found in joints), bone tissue, and macrophages. Less frequent dosing requirements still keep efficacy against gram-positive infections, which is convenient for prolonged treatment courses such as osteoarticular infections and endocarditis, making it an option for outpatient antibiotic therapy in difficult-to-treat populations where adherence may be challenging and those with limited access to healthcare facilities.
In vitro activity
Oritavancin shares certain properties with other members of the glycopeptide class of antibiotics, which includes vancomycin, the current standard of care for serious Gram-positive infections in the United States and Europe. It possesses potent and rapid bactericidal activity in vitro against a broad spectrum of both resistant and susceptible Gram-positive bacteria, including Staphylococcus aureus, MRSA, enterococci, and streptococci.
Oritavancin has potential use as a therapy for exposure to Bacillus anthracis, the Gram-positive bacterium that causes anthrax, having demonstrated efficacy in a mouse model both before and after exposure to the bacterium. Oritavancin demonstrates in vitro activity against both the planktonic and biofilmstates of staphylococci associated with prosthetic joint infection (PJI), albeit with increased minimum biofilm bactericidal concentration (MBBC) compared to Minimum inhibitory concentrations (MIC) values. Moreover oritavancin has demonstrated activity against in vitro to vancomycin-susceptible enterococci (VSE) and vancomycin-resistant enterococci (VRE) in both planktonic and biofilm states.
Mechanism
The 4'-chlorobiphenylmethyl group disrupts the cell membrane of Gram-positive bacteria.
It also acts by inhibition of transglycosylation and inhibition of transpeptidation.
Synergism
Several antibiotics have been tested as partner drugs of oritavancin. Among these "companions" drugs, fosfomycin displayed (in vitro and in vivo) synergistic activity when administered together with oritavancin against VRE strains (both vanA and vanB), including biofilm-producing isolates. This synergistic action has also been proposed for the prevention of vascular graft infections by impregnating prostheses with a combination of oritavancin and fosfomycin.
Spectrum of Activity
Oritavancin is active against gram-positive aerobic bacteria such as enterococci, staphylococci, streptococci, and anaerobic bacteria such as Clostridioides difficile , Clostridium perfringens , Peptostreptococcus spp. , and Propionibacterium acnes. Oritavancin's spectrum of activity shows similarities to vancomycin, but with lower minimum inhibitory concentrations (MIC).
Clinical trials
In 2003, results were presented from two pivotal phase-III clinical trials testing the efficacy of daily intravenous oritavancin for the treatment of acute bacterial skin and skin-structure infections (ABSSSI) caused by Gram-positive bacteria. The primary endpoints of both studies were met, with oritavancin achieving efficacy with fewer days of therapy than the comparator agents vancomycin followed by cephalexin. Oritavancin showed a statistically significant improved safety profile with a 19% relative reduction in the overall incidence of adverse events versus vancomycin/cephalexin in the second and larger pivotal trial.
Osteomyelitis remains a formidable foe in an era of increasing incidence of Methicillin-resistant Staphylococcus aureus (MRSA) with limited guidance for treatment optimization. The success observed in many patients suggests multi-dose oritavancin may prove advantageous for chronic osteomyelitis but further research is needed to define the optimal dose and frequency of oritavancin for the treatment of chronic osteomyelitis.
History
Originally discovered and developed by Eli Lilly, oritavancin was acquired by InterMune in 2001 and then by Targanta Therapeutics in late 2005.
In December 2008, the U.S. Food and Drug Administration (FDA) declined to approve oritavancin without additional studies, and an EU application was withdrawn.
In 2009, The Medicines Company acquired the development rights, completed clinical trials and submitted a new drug application to the FDA in February 2014. On 6 August 2014, the United States FDA approved oritavancin to treat skin infections.
A marketing authorization valid throughout the European Union was granted in March 2015, for the treatment of acute bacterial skin and skin structure infections in adults.
References
CYP3A4 inducers
Drugs developed by Eli Lilly and Company
Glycopeptide antibiotics | Oritavancin | Chemistry | 1,178 |
10,155,758 | https://en.wikipedia.org/wiki/Cetruminantia | The Cetruminantia are a clade made up of the Cetancodontamorpha (or Whippomorpha) and their closest living relatives, the Ruminantia.
Cetruminantia's placement within Artiodactyla can be represented in the following cladogram:
Classification
Order Artiodactyla (even-toed ungulates)
Tylopoda (camelids)
Artiofabula (ruminants, pigs, peccaries, whales, and dolphins)
Suina (pigs and peccaries)
Cetruminantia (ruminants, whales, and dolphins)
Suborder Ruminantia (antelope, buffalo, cattle, goats, sheep, deer, giraffes, and chevrotains)
Family Antilocapridae (pronghorn)
Family Bovidae, 135 species (antelope, bison, buffalo, cattle, goats, and sheep)
Family Cervidae, 55~94 species (deer, elk, and moose)
Family Giraffidae, 2 species (giraffes, okapis)
Family Moschidae, 4~7 species (musk deer)
Family Tragulidae, 6~10 species (chevrotains, or mouse deer)
Suborder Whippomorpha (aquatic or semi-aquatic even-toed ungulates)
Infraorder Ancodonta
Family Hippopotamidae, 2 species (hippopotamuses)
Infraorder Cetacea (whales, dolphins, and porpoises)
Mysticeti (baleen whales)
Family Balaenidae, 2~4 species (right whales and bowhead whales)
Family Balaenopteridae, 6~9 species (rorquals)
Family Eschrichtiidae, 1 species (gray whale)
Family Neobalaenidae, 1 species (pygmy right whale)
Odontoceti (toothed whales, dolphins, and porpoises)
Superfamily Delphinoidea (dolphins, arctic whales, porpoises, and relatives)
Family Delphinidae, 38 species (dolphins, killer whales, and relatives)
Family Monodontidae, 2 species (beluga and narwhal)
Family Phocoenidae, 6 species (porpoises)
Superfamily Physeteroidea (sperm whales)
Family Kogiidae, 2 species (pygmy and dwarf sperm whales)
Family Physeteridae, 1 species (common sperm whale)
Superfamily Ziphoidea (beaked whales)
Family Ziphidae, 22 species (modern beaked whales)
Superfamily Platanistoidea (river dolphins)
Family Iniidae, 1~3 species (South American river dolphin(s))
Family Lipotidae, 1 species (baiji or Chinese river dolphin)
Family Platanistidae, 1~2 species (Asian river dolphin(s))
Family Pontoporiidae, 1 species (La Plata dolphin)
References
Artiofabula
Phylogenetics | Cetruminantia | Biology | 626 |
563,219 | https://en.wikipedia.org/wiki/369%20%28number%29 | 369 (three hundred [and] sixty-nine) is the natural number following 368 and preceding 370.
In mathematics
369 is the magic constant of the 9 × 9 magic square and the n-Queens Problem for n = 9.
There are 369 free octominoes (polyominoes of order 8).
369 is a Ruth-Aaron Pair with 370. The sums of their prime factors are equivalent.
References
Integers | 369 (number) | Mathematics | 92 |
46,782,092 | https://en.wikipedia.org/wiki/Resistance%20paper | Resistance paper, also known as conductive paper and by the trade name Teledeltos paper is paper impregnated or coated with a conductive substance such that the paper exhibits a uniform and known surface resistivity. Resistance paper and conductive ink were commonly used as an analog two-dimensional electromagnetic field solver. Teledeltos paper is a particular type of resistance paper.
References
Analog computers
Electrical resistance and conductance | Resistance paper | Physics,Materials_science,Mathematics,Engineering | 88 |
25,140,586 | https://en.wikipedia.org/wiki/Conjoined%20gene | A conjoined gene (CG) is defined as a gene, which gives rise to transcripts by combining at least part of one exon from each of two or more distinct known (parent) genes which lie on the same chromosome, are in the same orientation, and often (95%) translate independently into different proteins. In some cases, the transcripts formed by CGs are translated to form chimeric or completely novel proteins.
Several alternative names are used to address conjoined genes, including combined gene and complex gene, fusion gene, fusion protein, read-through transcript, co-transcribed genes, bridged genes, spanning genes, hybrid genes, locus-spanning transcripts, etc.
At present, 800 CGs have been identified in the entire human genome by different research groups across the world including Prakash et al., Akiva et al., Parra et al., Kim et al., and in the 1% of the human genome in the ENCODE pilot project. 36% of all these CGs could be validated experimentally using RT-PCR and sequencing techniques. However, only a very limited number of these CGs are found in the public human genome resources such as the Entrez Gene database, the UCSC Genome Browser and the Vertebrate Genome Annotation (Vega) database. More than 70% of the human conjoined genes are found to be conserved across other vertebrate genomes with higher order vertebrates showing more conservation, including the closest human ancestor, chimpanzee. Formation of CGs is not only limited to the human genome but some CGs have also been identified in other eukaryotic genomes, including mouse and drosophila. There are a few web resources which include information about some CGs in addition to the other fusion genes, for example, ChimerDB and HYBRIDdb. Another database, ConjoinG, is a comprehensive resource dedicated only to the 800 Conjoined Genes identified in the entire human genome.
See also
Gene expression
References
Genes
Gene expression | Conjoined gene | Chemistry,Biology | 419 |
166,939 | https://en.wikipedia.org/wiki/Newi | Newi is an acronym for NEw World Infrastructure, a software architecture for software componentry, mostly known as Newi Business Objects which coined the term business object. Newi was developed by Oliver Sims at the software engineering company Integrated Object Systems, England. It was one of the first implemented architectures for software components.
Overview
Newi was what today is called a component container. The concepts behind the Newi middleware can be found in Oliver Sims' book "Business Objects", McGraw-Hill 1994. In spite of the title, the book was about software components.
Newi components were language-neutral. That is, a Newi component could be written in one of a variety of languages that was supported by Newi. At its height, Newi supported software components written in Cobol, Ada, C, C++, Rexx, and Java. Platforms supported included Windows 3.1, Win95, WinNT, three varieties of Unix - and a prototype supporting components written in RPG was running on the AS400.
Newi components were intended to be "objects in the large". There was a form of sub/supertyping which was implemented by the infrastructure through an intelligent delegation mechanism. For example, a component written in C could be "subtyped" by a component written in Cobol. Component names (or types?) were separated from the code implementation module. Messages (both sync and async) were passed using a proprietary form of "tagged data" (a similar concept to today's XML). There was also a notification service. The various system services (including the GUI framework and communications subsystems) were implemented as Newi components. Throughout, there was a rigorous focus on making the programming of application components as simple as possible, with Newi providing many transparencies.
From the start, Newi was targeted at both front-end GUI systems and back-end server systems. The front-end version had a GUI run-time framework implemented as components. The component concept fitted very well with the object-based UI provided. Hence a designer/programmer used the same technical code structure to implement both front-end and back-end business function.
History
The initial concept behind Newi originated in 1989 when Oliver Sims, then working for IBM, saw the need for an infrastructure whereby a given real-world business concept (process or entity) could be implemented as a software module that could be plugged into a running system. Applications would be created by composing an appropriate set of modules. IBM UK funded development of the concept through collaboration with Softwright, a UK bespoke software company.
After several successful prototypes, and an early AS400 production version, a joint venture called Integrated Object Systems (IOS) was created in 1993 to exploit the concept. The first version of Newi was announced and shipped in 1994.
In early 1996, IOS was bought by SSA (System Software Associates, Inc), who saw great potential in Newi. The software was significantly further developed within SSA, in particular in its back-end capability, as well as having its underlying communications function moved to a COTS Corba product that provided the communications "wet string" while maintaining the Newi programming model and loosely coupled component interaction. Tools were also significantly expanded. SSA also announced an early and proprietary form of web services, based on the re-developed Newi, called "Semantic Message Gateways", or SMG.
In 1998, for reasons other than their technology base, SSA had to downsize dramatically; Newi development was halted then abandoned, and the development team (around forty people in UK and US) was dispersed.
See also
business object
Software component
References
Further reading
Peter Eeles and Oliver Sims, Building Business Objects, Wiley 1998.
Peter Herzum and Oliver Sims, Business Component Factory, Wiley 2000.
Component-based software engineering
History of computing in the United Kingdom | Newi | Technology | 796 |
32,679,450 | https://en.wikipedia.org/wiki/Calcium-binding%20EGF%20domain | In molecular biology, the calcium-binding EGF domain is an EGF-like domain of about forty amino-acid residues found in epidermal growth factor (EGF). This domain is present in a large number of membrane-bound and extracellular, mostly animal, proteins. Many of these proteins require calcium for their biological function and a calcium-binding site has been found at the N-terminus of some EGF-like domains. Calcium-binding may be crucial for numerous protein-protein interactions.
For human coagulation factor IX it has been shown that the calcium-ligands form a pentagonal bipyramid. The first, third and fourth conserved negatively charged or polar residues are side chain ligands. The latter is possibly hydroxylated. A conserved aromatic residue, as well as the second conserved negative residue, are thought to be involved in stabilising the calcium-binding site.
As in non-calcium binding EGF-like domains, there are six conserved cysteines and the structure of both types is very similar as calcium-binding induces only strictly local structural changes.
References
Protein domains | Calcium-binding EGF domain | Biology | 229 |
54,743 | https://en.wikipedia.org/wiki/Inbreeding | Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and other consequences that may arise from expression of deleterious recessive traits resulting from incestuous sexual relationships and consanguinity. Animals avoid inbreeding only rarely.
Inbreeding results in homozygosity which can increase the chances of offspring being affected by recessive traits. In extreme cases, this usually leads to at least temporarily decreased biological fitness of a population (called inbreeding depression), which is its ability to survive and reproduce. An individual who inherits such deleterious traits is colloquially referred to as inbred. The avoidance of expression of such deleterious recessive alleles caused by inbreeding, via inbreeding avoidance mechanisms, is the main selective reason for outcrossing. Crossbreeding between populations sometimes has positive effects on fitness-related traits, but also sometimes leads to negative effects known as outbreeding depression. However, increased homozygosity increases the probability of fixing beneficial alleles and also slightly decreases the probability of fixing deleterious alleles in a population. Inbreeding can result in purging of deleterious alleles from a population through purifying selection.
Inbreeding is a technique used in selective breeding. For example, in livestock breeding, breeders may use inbreeding when trying to establish a new and desirable trait in the stock and for producing distinct families within a breed, but will need to watch for undesirable characteristics in offspring, which can then be eliminated through further selective breeding or culling. Inbreeding also helps to ascertain the type of gene action affecting a trait. Inbreeding is also used to reveal deleterious recessive alleles, which can then be eliminated through assortative breeding or through culling. In plant breeding, inbred lines are used as stocks for the creation of hybrid lines to make use of the effects of heterosis. Inbreeding in plants also occurs naturally in the form of self-pollination.
Inbreeding can significantly influence gene expression which can prevent inbreeding depression.
Overview
Offspring of biologically related persons are subject to the possible effects of inbreeding, such as congenital birth defects. The chances of such disorders are increased when the biological parents are more closely related. This is because such pairings have a 25% probability of producing homozygous zygotes, resulting in offspring with two recessive alleles, which can produce disorders when these alleles are deleterious. Because most recessive alleles are rare in populations, it is unlikely that two unrelated partners will both be carriers of the same deleterious allele; however, because close relatives share a large fraction of their alleles, the probability that any such deleterious allele is inherited from the common ancestor through both parents is increased dramatically. For each homozygous recessive individual formed there is an equal chance of producing a homozygous dominant individual — one completely devoid of the harmful allele. Contrary to common belief, inbreeding does not in itself alter allele frequencies, but rather increases the relative proportion of homozygotes to heterozygotes; however, because the increased proportion of deleterious homozygotes exposes the allele to natural selection, in the long run its frequency decreases more rapidly in inbred populations. In the short term, incestuous reproduction is expected to increase the number of spontaneous abortions of zygotes, perinatal deaths, and postnatal offspring with birth defects. The advantages of inbreeding may be the result of a tendency to preserve the structures of alleles interacting at different loci that have been adapted together by a common selective history.
Malformations or harmful traits can stay within a population due to a high homozygosity rate, and this will cause a population to become fixed for certain traits, like having too many bones in an area, like the vertebral column of wolves on Isle Royale or having cranial abnormalities, such as in Northern elephant seals, where their cranial bone length in the lower mandibular tooth row has changed. Having a high homozygosity rate is problematic for a population because it will unmask recessive deleterious alleles generated by mutations, reduce heterozygote advantage, and it is detrimental to the survival of small, endangered animal populations. When deleterious recessive alleles are unmasked due to the increased homozygosity generated by inbreeding, this can cause inbreeding depression.
There may also be other deleterious effects besides those caused by recessive diseases. Thus, similar immune systems may be more vulnerable to infectious diseases (see Major histocompatibility complex and sexual selection).
Inbreeding history of the population should also be considered when discussing the variation in the severity of inbreeding depression between and within species. With persistent inbreeding, there is evidence that shows that inbreeding depression becomes less severe. This is associated with the unmasking and elimination of severely deleterious recessive alleles. However, inbreeding depression is not a temporary phenomenon because this elimination of deleterious recessive alleles will never be complete. Eliminating slightly deleterious mutations through inbreeding under moderate selection is not as effective. Fixation of alleles most likely occurs through Muller's ratchet, when an asexual population's genome accumulates deleterious mutations that are irreversible.
Despite all its disadvantages, inbreeding can also have a variety of advantages, such as ensuring a child produced from the mating contains, and will pass on, a higher percentage of its mother/father's genetics, reducing the recombination load, and allowing the expression of recessive advantageous phenotypes. Some species with a Haplodiploidy mating system depend on the ability to produce sons to mate with as a means of ensuring a mate can be found if no other male is available. It has been proposed that under circumstances when the advantages of inbreeding outweigh the disadvantages, preferential breeding within small groups could be promoted, potentially leading to speciation.
Genetic disorders
Autosomal recessive disorders occur in individuals who have two copies of an allele for a particular recessive genetic mutation. Except in certain rare circumstances, such as new mutations or uniparental disomy, both parents of an individual with such a disorder will be carriers of the gene. These carriers do not display any signs of the mutation and may be unaware that they carry the mutated gene. Since relatives share a higher proportion of their genes than do unrelated people, it is more likely that related parents will both be carriers of the same recessive allele, and therefore their children are at a higher risk of inheriting an autosomal recessive genetic disorder. The extent to which the risk increases depends on the degree of genetic relationship between the parents; the risk is greater when the parents are close relatives and lower for relationships between more distant relatives, such as second cousins, though still greater than for the general population.
Children of parent-child or sibling-sibling unions are at an increased risk compared to cousin-cousin unions. Inbreeding may result in a greater than expected phenotypic expression of deleterious recessive alleles within a population. As a result, first-generation inbred individuals are more likely to show physical and health defects, including:
The isolation of a small population for a period of time can lead to inbreeding within that population, resulting in increased genetic relatedness between breeding individuals. Inbreeding depression can also occur in a large population if individuals tend to mate with their relatives, instead of mating randomly.
Due to higher prenatal and postnatal mortality rates, some individuals in the first generation of inbreeding will not live on to reproduce. Over time, with isolation, such as a population bottleneck caused by purposeful (assortative) breeding or natural environmental factors, the deleterious inherited traits are culled.
Island species are often very inbred, as their isolation from the larger group on a mainland allows natural selection to work on their population. This type of isolation may result in the formation of race or even speciation, as the inbreeding first removes many deleterious genes, and permits the expression of genes that allow a population to adapt to an ecosystem. As the adaptation becomes more pronounced, the new species or race radiates from its entrance into the new space, or dies out if it cannot adapt and, most importantly, reproduce.
The reduced genetic diversity, for example due to a bottleneck will unavoidably increase inbreeding for the entire population. This may mean that a species may not be able to adapt to changes in environmental conditions. Each individual will have similar immune systems, as immune systems are genetically based. When a species becomes endangered, the population may fall below a minimum whereby the forced interbreeding between the remaining animals will result in extinction.
Natural breedings include inbreeding by necessity, and most animals only migrate when necessary. In many cases, the closest available mate is a mother, sister, grandmother, father, brother, or grandfather. In all cases, the environment presents stresses to remove from the population those individuals who cannot survive because of illness.
There was an assumption that wild populations do not inbreed; this is not what is observed in some cases in the wild. However, in species such as horses, animals in wild or feral conditions often drive off the young of both sexes, thought to be a mechanism by which the species instinctively avoids some of the genetic consequences of inbreeding. In general, many mammal species, including humanity's closest primate relatives, avoid close inbreeding possibly due to the deleterious effects.
Examples
Although there are several examples of inbred populations of wild animals, the negative consequences of this inbreeding are poorly documented. In the South American sea lion, there was concern that recent population crashes would reduce genetic diversity. Historical analysis indicated that a population expansion from just two matrilineal lines was responsible for most of the individuals within the population. Even so, the diversity within the lines allowed great variation in the gene pool that may help to protect the South American sea lion from extinction.
In lions, prides are often followed by related males in bachelor groups. When the dominant male is killed or driven off by one of these bachelors, a father may be replaced by his son. There is no mechanism for preventing inbreeding or to ensure outcrossing. In the prides, most lionesses are related to one another. If there is more than one dominant male, the group of alpha males are usually related. Two lines are then being "line bred". Also, in some populations, such as the Crater lions, it is known that a population bottleneck has occurred. Researchers found far greater genetic heterozygosity than expected. In fact, predators are known for low genetic variance, along with most of the top portion of the trophic levels of an ecosystem. Additionally, the alpha males of two neighboring prides can be from the same litter; one brother may come to acquire leadership over another's pride, and subsequently mate with his 'nieces' or cousins. However, killing another male's cubs, upon the takeover, allows the new selected gene complement of the incoming alpha male to prevail over the previous male. There are genetic assays being scheduled for lions to determine their genetic diversity. The preliminary studies show results inconsistent with the outcrossing paradigm based on individual environments of the studied groups.
In Central California, sea otters were thought to have been driven to extinction due to over hunting, until a small colony was discovered in the Point Sur region in the 1930s. Since then, the population has grown and spread along the central Californian coast to around 2,000 individuals, a level that has remained stable for over a decade. Population growth is limited by the fact that all Californian sea otters are descended from the isolated colony, resulting in inbreeding.
Cheetahs are another example of inbreeding. Thousands of years ago, the cheetah went through a population bottleneck that reduced its population dramatically so the animals that are alive today are all related to one another. A consequence from inbreeding for this species has been high juvenile mortality, low fecundity, and poor breeding success.
In a study on an island population of song sparrows, individuals that were inbred showed significantly lower survival rates than outbred individuals during a severe winter weather related population crash. These studies show that inbreeding depression and ecological factors have an influence on survival.
The Florida panther population was reduced to about 30 animals, so inbreeding became a problem. Several females were imported from Texas and now the population is better off genetically.
Measures
A measure of inbreeding of an individual A is the probability F(A) that both alleles in one locus are derived from the same allele in an ancestor. These two identical alleles that are both derived from a common ancestor are said to be identical by descent. This probability F(A) is called the "coefficient of inbreeding".
Another useful measure that describes the extent to which two individuals are related (say individuals A and B) is their coancestry coefficient f(A,B), which gives the probability that one randomly selected allele from A and another randomly selected allele from B are identical by descent. This is also denoted as the kinship coefficient between A and B.
A particular case is the self-coancestry of individual A with itself, f(A,A), which is the probability that taking one random allele from A and then, independently and with replacement, another random allele also from A, both are identical by descent. Since they can be identical by descent by sampling the same allele or by sampling both alleles that happen to be identical by descent, we have f(A,A) = 1/2 + F(A)/2.
Both the inbreeding and the coancestry coefficients can be defined for specific individuals or as average population values. They can be computed from genealogies or estimated from the population size and its breeding properties, but all methods assume no selection and are limited to neutral alleles.
There are several methods to compute this percentage. The two main ways are the path method and the tabular method.
Typical coancestries between relatives are as follows:
Father/daughter or mother/son → 25% ()
Brother/sister → 25% ()
Grandfather/granddaughter or grandmother/grandson → 12.5% ()
Half-brother/half-sister, Double cousins → 12.5% ()
Uncle/niece or aunt/nephew → 12.5% ()
Great-grandfather/great-granddaughter or great-grandmother/great-grandson → 6.25% ()
Half-uncle/niece or half-aunt/nephew → 6.25% ()
First cousins → 6.25% ()
Animals
Wild animals
Banded mongoose females regularly mate with their fathers and brothers.
Bed bugs: North Carolina State University found that bedbugs, in contrast to most other insects, tolerate incest and are able to genetically withstand the effects of inbreeding quite well.
Common fruit fly females prefer to mate with their own brothers over unrelated males.
Cottony cushion scales: 'It turns out that females in these hermaphrodite insects are not really fertilizing their eggs themselves, but instead are having this done by a parasitic tissue that infects them at birth,' says Laura Ross of Oxford University's Department of Zoology. 'It seems that this infectious tissue derives from left-over sperm from their father, who has found a sneaky way of having more children by mating with his daughters.'
Adactylidium: The single male offspring mite mates with all the daughters when they are still in the mother. The females, now impregnated, cut holes in their mother's body so that they can emerge. The male emerges as well, but does not look for food or new mates, and dies after a few hours. The females die at the age of 4 days, when their own offspring eat them alive from the inside.
Domestic animals
Breeding in domestic animals is primarily assortative breeding (see selective breeding). Without the sorting of individuals by trait, a breed could not be established, nor could poor genetic material be removed.
Homozygosity is the case where similar or identical alleles combine to express a trait that is not otherwise expressed (recessiveness). Inbreeding exposes recessive alleles through increasing homozygosity.
Breeders must avoid breeding from individuals that demonstrate either homozygosity or heterozygosity for disease causing alleles. The goal of preventing the transfer of deleterious alleles may be achieved by reproductive isolation, sterilization, or, in the extreme case, culling. Culling is not strictly necessary if genetics are the only issue in hand. Small animals such as cats and dogs may be sterilized, but in the case of large agricultural animals, such as cattle, culling is usually the only economic option.
The issue of casual breeders who inbreed irresponsibly is discussed in the following quotation on cattle:
Meanwhile, milk production per cow per lactation increased from 17,444 lbs to 25,013 lbs from 1978 to 1998 for the Holstein breed. Mean breeding values for milk of Holstein cows increased by 4,829 lbs during this period. High producing cows are increasingly difficult to breed and are subject to higher health costs than cows of lower genetic merit for production (Cassell, 2001).
Intensive selection for higher yield has increased relationships among animals within breed and increased the rate of casual inbreeding.
Many of the traits that affect profitability in crosses of modern dairy breeds have not been studied in designed experiments. Indeed, all crossbreeding research involving North American breeds and strains is very dated (McAllister, 2001) if it exists at all.
As a result of long-term cooperation between USDA and dairy farmers which led to a revolution in dairy cattle productivity, the United States has since 1992 been the world’s largest supplier of dairy bull semen. However, US genomic technology has resulted in the US dairy cattle population becoming "the most inbred it’s ever been" and the rate of increase in US national milk yield has tapered off. Efforts are now being made to identify desirable genes in cattle breeds not yet optimized by US dairy breeders in order to apply hybrid vigor to the US dairy cattle population and thus propel US dairy technology to even higher levels of productivity.
The BBC produced two documentaries on dog inbreeding titled Pedigree Dogs Exposed and Pedigree Dogs Exposed: Three Years On that document the negative health consequences of excessive inbreeding.
Linebreeding
Linebreeding is a form of inbreeding. There is no clear distinction between the two terms, but linebreeding may encompass crosses between individuals and their descendants or two cousins. This method can be used to increase a particular animal's contribution to the population. While linebreeding is less likely to cause problems in the first generation than does inbreeding, over time, linebreeding can reduce the genetic diversity of a population and cause problems related to a too-small gene pool that may include an increased prevalence of genetic disorders and inbreeding depression.
Outcrossing
Outcrossing is where two unrelated individuals are crossed to produce progeny. In outcrossing, unless there is verifiable genetic information, one may find that all individuals are distantly related to an ancient progenitor. If the trait carries throughout a population, all individuals can have this trait. This is called the founder effect. In the well established breeds, that are commonly bred, a large gene pool is present. For example, in 2004, over 18,000 Persian cats were registered. A possibility exists for a complete outcross, if no barriers exist between the individuals to breed. However, it is not always the case, and a form of distant linebreeding occurs. Again it is up to the assortative breeder to know what sort of traits, both positive and negative, exist within the diversity of one breeding. This diversity of genetic expression, within even close relatives, increases the variability and diversity of viable stock.
Laboratory animals
Systematic inbreeding and maintenance of inbred strains of laboratory mice and rats is of great importance for biomedical research. The inbreeding guarantees a consistent and uniform animal model for experimental purposes and enables genetic studies in congenic and knock-out animals. In order to achieve a mouse strain that is considered inbred, a minimum of 20 sequential generations of sibling matings must occur. With each successive generation of breeding, homozygosity in the entire genome increases, eliminating heterozygous loci. With 20 generations of sibling matings, homozygosity is occurring at roughly 98.7% of all loci in the genome, allowing for these offspring to serve as animal models for genetic studies. The use of inbred strains is also important for genetic studies in animal models, for example to distinguish genetic from environmental effects. The mice that are inbred typically show considerably lower survival rates.
Humans
Effects
Inbreeding increases homozygosity, which can increase the chances of the expression of deleterious or beneficial recessive alleles and therefore has the potential to either decrease or increase the fitness of the offspring. Depending on the rate of inbreeding, natural selection may still be able to eliminate deleterious alleles. With continuous inbreeding, genetic variation is lost and homozygosity is increased, enabling the expression of recessive deleterious alleles in homozygotes. The coefficient of inbreeding, or the degree of inbreeding in an individual, is an estimate of the percent of homozygous alleles in the overall genome. The more biologically related the parents are, the greater the coefficient of inbreeding, since their genomes have many similarities already. This overall homozygosity becomes an issue when there are deleterious recessive alleles in the gene pool of the family. By pairing chromosomes of similar genomes, the chance for these recessive alleles to pair and become homozygous greatly increases, leading to offspring with autosomal recessive disorders. However, these deleterious effects are common for very close relatives but not for those related on the 3rd cousin or greater level, who exhibit increased fitness.
Inbreeding is especially problematic in small populations where the genetic variation is already limited. By inbreeding, individuals are further decreasing genetic variation by increasing homozygosity in the genomes of their offspring. Thus, the likelihood of deleterious recessive alleles to pair is significantly higher in a small inbreeding population than in a larger inbreeding population.
The fitness consequences of consanguineous mating have been studied since their scientific recognition by Charles Darwin in 1839. Some of the most harmful effects known from such breeding includes its effects on the mortality rate as well as on the general health of the offspring. Since the 1960s, there have been many studies to support such debilitating effects on the human organism. Specifically, inbreeding has been found to decrease fertility as a direct result of increasing homozygosity of deleterious recessive alleles. Fetuses produced by inbreeding also face a greater risk of spontaneous abortions due to inherent complications in development. Among mothers who experience stillbirths and early infant deaths, those that are inbreeding have a significantly higher chance of reaching repeated results with future offspring. Additionally, consanguineous parents possess a high risk of premature birth and producing underweight and undersized infants. Viable inbred offspring are also likely to be inflicted with physical deformities and genetically inherited diseases. Studies have confirmed an increase in several genetic disorders due to inbreeding such as blindness, hearing loss, neonatal diabetes, limb malformations, disorders of sex development, schizophrenia and several others. Moreover, there is an increased risk for congenital heart disease depending on the inbreeding coefficient (See coefficient of inbreeding) of the offspring, with significant risk accompanied by an F =.125 or higher.
Prevalence
The general negative outlook and eschewal of inbreeding that is prevalent in the Western world today has roots from over 2000 years ago. Specifically, written documents such as the Bible illustrate that there have been laws and social customs that have called for the abstention from inbreeding. Along with cultural taboos, parental education and awareness of inbreeding consequences have played large roles in minimizing inbreeding frequencies in areas like Europe. That being so, there are less urbanized and less populated regions across the world that have shown continuity in the practice of inbreeding.
The continuity of inbreeding is often either by choice or unavoidably due to the limitations of the geographical area. When by choice, the rate of consanguinity is highly dependent on religion and culture. In the Western world, some Anabaptist groups are highly inbred because they originate from small founder populations that have bred as a closed population.
Of the practicing regions, Middle Eastern and northern Africa territories show the greatest frequencies of consanguinity.
Among these populations with high levels of inbreeding, researchers have found several disorders prevalent among inbred offspring. In Lebanon, Saudi Arabia, Egypt, and in Israel, the offspring of consanguineous relationships have an increased risk of congenital malformations, congenital heart defects, congenital hydrocephalus and neural tube defects. Furthermore, among inbred children in Palestine and Lebanon, there is a positive association between consanguinity and reported cleft lip/palate cases. Historically, populations of Qatar have engaged in consanguineous relationships of all kinds, leading to high risk of inheriting genetic diseases. As of 2014, around 5% of the Qatari population suffered from hereditary hearing loss; most were descendants of a consanguineous relationship.
Royalty and nobility
Inter-nobility marriage was used as a method of forming political alliances among elites. These ties were often sealed only upon the birth of progeny within the arranged marriage. Thus marriage was seen as a union of lines of nobility and not as a contract between individuals.
Royal intermarriage was often practiced among European royal families, usually for interests of state. Over time, due to the relatively limited number of potential consorts, the gene pool of many ruling families grew progressively smaller, until all European royalty was related. This also resulted in many being descended from a certain person through many lines of descent, such as the numerous European royalty and nobility descended from the British Queen Victoria or King Christian IX of Denmark. The House of Habsburg was known for its intermarriages; the Habsburg lip often cited as an ill-effect. The closely related houses of Habsburg, Bourbon, Braganza and Wittelsbach also frequently engaged in first-cousin unions as well as the occasional double-cousin and uncle–niece marriages.
In ancient Egypt, royal women were believed to carry the bloodlines and so it was advantageous for a pharaoh to marry his sister or half-sister; in such cases a special combination between endogamy and polygamy is found. Normally, the old ruler's eldest son and daughter (who could be either siblings or half-siblings) became the new rulers. All rulers of the Ptolemaic dynasty uninterruptedly from Ptolemy IV (Ptolemy II married his sister but had no issue) were married to their brothers and sisters, so as to keep the Ptolemaic blood "pure" and to strengthen the line of succession. King Tutankhamun's mother is reported to have been the half-sister to his father, Cleopatra VII (also called Cleopatra VI) and Ptolemy XIII, who married and became co-rulers of ancient Egypt following their father's death, are the most widely known example.
See also
References
External links
Dale Vogt, Helen A. Swartz and John Massey, 1993. Inbreeding: Its Meaning, Uses and Effects on Farm Animals. University of Missouri, Extension.
Consanguineous marriages with global map
Population genetics
Breeding
Incest
Kinship and descent | Inbreeding | Biology | 5,875 |
24,840,027 | https://en.wikipedia.org/wiki/Diversity%20arrays%20technology | Diversity Arrays Technology (DArT) is a high-throughput genetic marker technique that can detect allelic variations to provide comprehensive genome coverage without any DNA sequence information for genotyping and other genetic analysis. The general steps involve reducing the complexity of the genomic DNA with specific restriction enzymes, choosing diverse fragments to serve as representations for the parent genomes, amplify via polymerase chain reaction (PCR), inserting fragments into a vector to be placed as probes within a microarray, and then fluorescent targets from a reference sequence will be allowed to hybridize with probes and put through an imaging system. The objective is to identify and quantify various forms of DNA polymorphism within genomic DNA of sampled species.
First reported in 2001 by Damian Jaccoud, Andrzej Kilian, David Feinstein, and Kaiman Peng, DArT prioritized significant advantages over other traditional primer-based methods like the ability to analyze large amounts of various samples from a low amount of initial DNA. It also afforded low costs and faster results compared to related solid state DNA arrays that detected Single Nucleotide Polymorphisms (SNPs). Since its inception, the technology has been a major instrument in the analysis of polyploid plants as well as in the construction of physical and genetic maps to understand relations between species based on similarities and allelic variances among their genomes.
History
The concept was first developed by Damian Jaccoud, Andrzej Kilian, David Feinstein, and Kaiman Peng in 2001. They aimed to establish a genomic DNA-polymorphism detection and quantification technique that would increase throughput when compared to more traditional methods like Amplified Fragment Length Polymorphism (AFLP), Restriction Fragment Length Polymorphism (RFLP), Simple Sequence Repeats (SSR). They also aimed to minimize cost and reliance on sequenced genomes to identify polymorphisms which is a consequence of early immobilized, solid-states DNA arrays, like DNA chips, which solely identify SNPs. A byproduct of their discovery of a fast, low-cost whole-genome profiling method was that it also provided with the identification of SNPs as well as base-pair insertions, deletions, and shifts, which is an added layer of allelic variation between species analyzed.
Jaccoud, Kilian, Feinstein, and Peng selected nine subspecies of rice as their source for genomic DNA and polymorphism analysis. The analysis consisted of detecting the presence, or absence, of specific DNA polymorphisms with probing arrays as well as quantifying the strength of each signal, via fluorescence, within the subspecies. Upon selecting and extracting DNA samples from subjects, samples were digested with three specific restriction enzymes and ligated with T4 ligase. Following ligation into double stranded DNA, dilution as well as extraction of a short amount of mixture to use as a PCR template was performed. Products were placed into a pCR2.1-TOPO vector and subsequently transformed into E. coli, who were selected based on resistance to ampicillin and pigmentation from the X-gal interaction. Cloned cells are amplified with PCR-amplified, purified, and introduced into a microarray. Reference DNA and samples were mixed with fluorescent dyes, Cy3 or Cy5, mixed, denatured, and allowed to hybridize to further reintroduce them into the microarray for further analysis. Results reported that the use of DArT was able to detect the presence or absence of polymorphism in an expedient manner as compared to RFLP as well as quantify the polymorphisms detected. In addition, DArT was able to minimize the amount of initial DNA required to conduct the analysis significantly compared to other methods.
Procedure
The DArT is broken down into three essential steps: Complexity reduction, genomic representation, and DArT assay.
Complexity reduction
This step of the process deals with reducing large complex genomic DNA of selected species into more, manageable fragmented components through the use of specific restriction enzymes. In addition, this step exclusively relies on digestion enzymes over a couple effort of digestion enzymes and primers due to the reported increased polymorphism identified across analyzed samples. The PstI enzyme is a commonly used restriction enzyme for this step because of its specificity to the nonrepetitive, nonmethylated genome of species.
Genomic representation
Once genomic DNA has been reduced to a manageable size from the previous step by incorporating one or two specific restriction enzymes, the next step involves selecting for the fragments that include largest amount of significant polymorphism across gene pool. These selected fragments are termed “representations” as they are smaller representations of the initial, larger genomic DNA. It is eminent to avoid repetitive sequences when selecting fragments as these will exhibit the lowest amount of polymorphism within analyzed genomic DNA.
DArT assay
Digested sequences are ligated using T4 ligase to produce double stranded DNA. A small amount of ligated mixture will be diluted then amplified via PCR. During PCR, it is important to use primers complementary to the restriction-enzymes’ cutting sites and RedTaq polymerase, which is rarely inhibited. Mix product into an amplified, gene pool representation and ligate onto vector pCR2.1-TOPO. Following representation insertion into vector, transform vector into E. coli cells via electrical shocking or chemical means. Incubate cells and select based on ampicillin resistance and white-pigmentation from inactive β-galactosidase gene in a medium containing X-gal. Inserts are then amplified via PCR and inserted as spotters into a microarray slide. Slides are centrifuge to isolate inserts, which are then purified.
Fluorescent dyes, Cy3 or Cy5, are added to the microarray targets, which are genomic representations. Following addition of the fluorescent dye, targets are added to microarray probes containing the amplified E. coli clones where denaturing and subsequent hybridization, if possible, takes place. Following hybridization, slides are washed and scanned with an imaging system that targets fluorescent signals with the incorporation of an open-source software called DArTsoft. Interactions and dissimilarities between probe and various targets are used to develop a histogram which quantifies and identifies several forms of DNA polymorphism among analyzed genomes.
Applications
Molecular breeding
The ability to identify and quantify allelic variations among genomes without the need for a sequenced genome is of great value to DArT and has large implications in the molecular breeding sector. By comparing crops with phenotypes such as higher yields of produce or resistance to certain environmental parasites, a phenotype can be directly linked to a DNA polymorphism identified among related species through DArT. DArT is also able to outperform other genotyping techniques with polyploids due to the absence of primer competition found in other techniques. Polyploids are commonly found among agriculturally important crops. For example, DArT has been used to conduct genome-wide analysis among Musa species, which includes bananas and plantains, which led to the development of a phylogenetic cladogram based on genetic markers derived from DArT techniques. These developments enhance breeding knowledge to obtain desirable yields and products.
Expedited recognition of markers found with genes responsible for phenotypes is also being studied in animals with the help of DArT. Mosquitoes’ resistance to insecticide has been linked to specific mutations in genes that confer resistance to certain species of mosquitoes over others. Genotypic variations were found through markers while conducting DArT analysis on relevant samples.
Genomic mapping
Since DArT is able to find genetic relations among species within a metagenome in a cheap and expedited manner, it has been integral to developing physical and genetic maps of closely related species. In its inception, DArT was used to develop phylogenetic cladograms of rice subspecies based on the presence or absence of DNA fragments in each species’ genome. In the same manner, DArT was incorporated in fabricating genetic maps for A. thaliana by conducting an automated version of DArT. Wheat, a hexaploid, is also another crop that has benefited from implementation of a DArT analysis as a Bacterial Artificial Chromosome (BAC) of the largest chromosome, 3B, was created from markers detected through DArT assays.
References
Molecular genetics | Diversity arrays technology | Chemistry,Biology | 1,719 |
52,457,311 | https://en.wikipedia.org/wiki/Bouligand%20structure | A Bouligand structure is a layered and rotated microstructure resembling plywood, which is frequently found in naturally evolved materials. It consists of multiple lamellae, or layers, each one composed of aligned fibers. Adjacent lamellae are progressively rotated with respect to their neighbors. This structure enhances the mechanical properties of materials, especially its fracture resistance, and enables strength and in plane isotropy. It is found in various natural structures, including the cosmoid scale of the coelacanth, and the dactyl club of the mantis shrimp and many other stomatopods. In physics, these structures were conceived in 1869 by Ernest Reusch
and are called Reusch piles.
Due to its desirable mechanical properties, there are ongoing attempts to replicate Bouligand arrangements in the creation of failure resistant bioinspired materials. For example, it has been shown that layered composites (such as CFRP) utilizing this structure have enhanced impact properties. However, replicating the structure on small length scales is challenging, and the development and advancement of manufacturing techniques continually improves the ability to replicate this desirable structure.
Mechanical Properties
Toughening Mechanisms
The Bouligand structure found in many natural materials is credited with imparting a very high toughness and fracture resistance to the overall material it is a part of. The mechanisms by which this toughening occurs are many, and no one mechanism has yet to be identified as the main source of the structure's toughness. Both computational work and physical experiments have been done to determine these pathways by which the structure resists fracture so that synthetic tough Bouligand structures can be taken advantage of.
Crack deflection of one form or another is considered the main toughening mechanism in the bouligand structure. Deflection can take the form of crack tilting, and crack bridging. In the former, the crack propagates along the direction of the fiber plane; at the interface with the matrix material. Once the energy release rate at the tip is sufficiently low, the crack can no longer propagate along the fiber direction and must switch to crack bridging. This mode involves the crack changing direction drastically and cutting through fibers to reach a new plane to propagate along. A combination of crack tilting and crack bridging in the bouligand structure results in a highly distorted and enlarged crack. This causes the new surface area created by the propagating crack to increase dramatically relative to a straight crack; making further propagation less and less favorable and in turn toughening the material.
In addition to crack deflection which simply causes a single crack to change direction and follow a more tortuous path, the bouligand structure can also tolerate multiple cracks to form and keep them from coalescing. This is sometimes termed crack twisting.
Inherently accompanying crack deflection, tilting, bridging and twisting is the mixing of fracture modes. Fracture modes include opening, in-plane shear, and out-of-plane shear. The mixing of these modes via crack bridging, tilting and twisting all greatly complicate the stress fields experienced by the material; helping to dissipate the force on any one laminate plane.
Impact Resistance
Impact resistance in materials is differentiated from toughening in general by the rate at which stress is applied. In impact testing, the rate at which either stress or strain is applied to the sample is much higher than so-called static testing. In synthetic nano-cellulose films formed into bouligand structures, it was shown that as the pitch angle was increased, the density quickly drops to a roughly constant value as the films are not able to neatly stack onto each other. This value rises again between 42 and 60 degrees and re-stabilizes at higher angles. This reduction in density is accompanied by a sharp increase in both specific ballistic limit velocity, and specific energy absorption. The relatively small angles of 18 to 42 degrees that correlate to the lowest density for the bouligand structure also are shown to have better impact resistance, and better energy adsorption than traditional synthetic quasi-isotropic structures made for impact resistance. This experimentally optimized range of angles for impact resistance is consistent with the range of angles between fiber layers found in natural examples of the bouligand structure.
Another means of toughening the bouligand structure is by shear wave filtering. The periodic and hierarchical nature of the Bouligand structure, creates a shear wave filtering effect that is especially effective during high intensity dynamic loads. As the force is applied, specific frequencies that are in shear are not permitted to transmit through the layered structure, creating a band gap in the transmitted energies and decreasing the effective energy felt by the system. The pitch angle of the layers, thickness of the layers, and number of layers present in the material all effect which frequencies are filtered out.
Adaptability
Adjustment of the Bouligand structure during loading has been measured using small angle X-ray scattering (SAXS). The two adjustment effects are the change in angle between the collagen fibrils and tensile axis, and the stretching of collagen fibrils. There are four mechanisms through which these adjustments occur.
Fibrils rotate because of interfibrillar shear: As a tensile force is applied, fibrils rotate to align with the tensile direction. During deformation, the shear component of the applied stress causes the hydrogen bonds between fibrils to break and then reform after fibril adjustment.
Collagen fibrils stretch: Collagen fibrils can elastically stretch, resulting in fibrils re-orientating to align with the tensile direction.
Tensile opening of interfibrillar gaps: Fibrils highly misoriented with the tensile direction can separate, creating an opening.
"Sympathetic" lamella rotation: A lamella is able to rotate away from the tensile direction if it is sandwiched between two lamellae that are reorienting themselves towards the tensile direction. This can happen if the bonding between these lamellae is high.
Ψ refers to the angle between the tensile axis and the collagen fibril. Mechanisms 1 and 2 both decrease Ψ. Mechanisms 3 and 4 can increase Ψ, as in, the fibril moves away from the tensile axis. Fibrils with a small Ψ stretch elastically. Fibrils with a large Ψ are compressed, since adjacent lamellae contract in accordance with Poisson's ratio, which is a function of strain anisotropy.
Single vs. Double Bouligand Structure
The most common Bouligand structure found in nature is the twisted plywood structure where there is a constant angle of misalignment between layers. A rare variation of this structure is the so-called "double twisted" Bouligand structure seen in Coelacanth. This structure uses stacks of two as units to be twisted with respect to each other at some constant misalignment angle. The two fibril layers in each of these units in this case lay such that their fibril orientation is perpendicular to each other.
The mechanical differences between the single and double twisted bouligand structure has been observed. It was shown that the double bouligand structure is stiffer and tougher than the more common single bouligand structure. The increase in stiffness is also accompanied by a reduction of flexibility. The increased strength is attributed in part to an addition to the structure of "inter-bundle fibrils" that run up and down the stack of layers, perpendicular to the twisted fiber planes. These fiber bundles help keep the structure together by greatly increasing the energy needed for inter-fibril sliding. These bundles are coupled with the double twisted nature of the plywood arraignment, which shifts the direction a crack would like to grow drastically with each layer.
It has also been observed that a structure can form mostly similar to the single twisted bouligand structure, but with a non-constant angle of misalignment. It is still unclear how this particular structural difference affects mechanical properties.
Examples in Nature
Arthropods
The arthropod exoskeleton is highly hierarchical. Polysaccharide chitin fibrils arrange with proteins to form fibers, the fibers coalesce into bundles, and then the bundles arrange into horizontal planes which are stacked helicoidally, forming the twisted plywood Bouligand structure. Repeating Bouligand structures form the exocuticle and endocuticle. Differences in the Bouligand structure of the exocuticle and endocuticle have been found to be critical for analyzing the mechanical properties of both regions.
Arthropods have exoskeletons that provide protection from the environment, mechanical load support, and body structure. The outer layer, called the epicuticle, is thin and waxy and is the main waterproofing barrier. Below is the procuticle, which is designed as the main structural element to the body. The procuticle is made of two sections, the exocuticle on the outer part, and the endocuticle on the inner part. The exocuticle is denser than the endocuticle; the endocuticle makes up about 90 volume % of the exoskeleton. Both the exocuticle and endocuticle are made with a Bouligand structure.
Crabs
In crab exoskeletons, calcite and amorphous calcium carbonate are the minerals deposited in the chitin-protein hierarchical matrix. The sheep crab (Loxorhynchun grandis), like other crabs, has a highly anisotropic exoskeleton. The spacing between the (x-y) plane Bouligand lamellae in the crab exocuticle is ~3-5μm, whereas the interlamellar spacing in the endocuticle is much greater, about 10-15μm. The smaller spacing of the exocuticle results in a higher lamellae density in the exocuticle. There is a higher hardness measurement in the exocuticle than the endocuticle, which is attributed to a higher mineral content in the exocuticle. This gives a higher wear resistance and hardness on the surface of the exoskeleton, thus giving the crab a greater degree of protection. Under stress, the Bouligand planes fail via normal bundle fracture or bundle separation mechanisms. The exocuticle-endocuticle interface is the most critical region and typically where failure first occurs, due to the anisotropic structure and discontinuity of Bouligand planes and spacing at this interface.
In the z-direction, porous tubules exist normal to the Bouligand planes that penetrate the exoskeleton. The function of these tubules is to transport ions and nutrients to the new exoskeleton during the molting process. The presence of these tubules, which have a helical structure, results in a ductile necking region during tension. An increased degree of ductility increases the toughness of the crab exoskeleton.
Lobster
The Homarus americanus (American lobster) is an arthropod with an exoskeleton structure similar to the crabs above, and with similar trends comparing the endo- and exo- cuticles. An important note for the lobster exoskeleton structural/mechanical properties is the impact of the honeycomb structure formed by the Bouligand planes. The stiffness values for the exocuticle in lobster range from 8.5-9.5 GPa, while the endocuticle ranges from 3–4.5 GPa. Gradients in the honeycomb network, especially at the interface between the endo- and exo- cuticle are believed to be the reason for this discrepancy between the structures.
Mantis Shrimp
Stomatopods have thoracic appendages that are used to hunt prey. The appendages can either be spear-like or club-like, depending on the species. Mantis shrimp with a club-like appendage, or "dactyl club", uses it to smash the shell of prey such as mollusks or crabs. The peacock mantis shrimp is a species of mantis shrimp that has a dactyl club. The clubs are able to withstand fracture under the high stress waves associated with blows against prey. This is possible due to the multi-regional structure of the clubs, which includes a region incorporating a Bouligand structure.
The outer, top region of the club is called the impact region. The impact region is supported periodic zones and a striated region. The periodic regions are below the impact region, on the inside of the club. The striated region is present on the sides of the club, surrounding the edges of the periodic region.
The impact region is about 50 to 70 μm thick, and is made with highly crystallized hydroxyapatite. The periodic region is dominated by an amorphous calcium carbonate phase. Surrounded by the amorphous mineral phase are chitin fibrils, which make up a Bouligand structure. The layered arrangement of the periodic region corresponds to a compete 180° rotation of the fibers. The impact region has a similar structure, but with a larger pitch distance (length between compete 180° rotation). The striated region is made of highly aligned parallel chitin fiber bundles.
The club appendage can sustain high intensity load by shear wave filtering because of the periodicity and chirality of its Bouligand structure. Catastrophic crack growth is hindered in two ways. When crack growth follows the helicoidal structure between layers of chitin fibers, a large surface area per crack length is produced. Therefore, there is high total energy dissipated during club impact and crack propagation. When cracks propagate through neighboring layers, growth is hampered because of modulus oscillation. The Bouligand structure has anisotropic stiffness, resulting in an elastic modulus oscillation through the layers. Overall damage tolerance is improved, with crack propagation depending on growth direction in relation to chitin fiber orientation.
Fish
Arapaima
The Arapaima fish's outer scales are designed to resist piranha bites. This is achieved through the scales' hierarchical architecture. The thinness of the scales and their overlapping arrangement allow for flexibility during movement. This also influences how much a single scale will bend when a predator attacks.
In the species Arapaima gigas, each scale has two distinct structural regions which results in a scale that is resistant to puncture and bending. The outer layer is about 0.5 mm thick and is highly mineralized, which makes it hard, promoting predator tooth fracture. The inner layer is about 1 mm thick and is made of mineralized collagen fibrils arranged in a Bouligand structure. In the fibrils, collagen molecules are embedded with hydroxyapatite mineral nanocrystals. Collagen fibrils align in the same direction to make a layer of collagen lamella, of about 50 μm in thickness. Lamellae are stacked with a misalignment in orientation, creating a Bouligand structure.
When the scales bend during an attack, stress is distributed due to the corrugated morphology. The largest deformation is designed to occur in the inner core layer. The inner layer can support more plastic deformation than the brittle outer layer. This is because the Bouligand structure can adjust its lamellar layers to adapt to applied forces.
Adjustment of the Bouligand structure during loading has been measured using small angle X-ray scattering (SAXS). The four mechanisms through which adjustments occur are fibril rotation, collagen fibril stretching, tensile opening between fibrils, and sympathetic lamella rotation.
Fibrils adapting to the loading environment enhance the flexibility of the lamellae. This contributes resistance to scale bending, and therefore increases fracture resistance. As a whole, the outer scale layer is hard and brittle, while the inner layer is ductile and tough.
Carp
A similar Bouligand structure was found in the scales of the common carp (Cyprinus carpio). Compared to the arapaima, the mineral content in carp scales is lower, while exhibiting higher total energy dissipation in tensile testing as well as higher fibril extensibility.
Biomimicry
Additive Manufacturing
Additive manufacturing is a popular upcoming form of industry which allows for complex geometries and unique performance characteristics for AM parts. The main issue with mechanical properties of AM parts is the introduction of microstructural heterogeneities within layers of deposited material. These defects, including porosity and unique interfaces, result in anisotropy of the mechanical response of the workpiece, which is undesirable. To combat this anisotropic mechanical response, a Bouligand-inspired tool path is used to deposit the material in a twisted Bouligand structure. This results in a stress transfer mechanism which uses interlayer heterogeneities as stress deflection points, thus strengthening the workpiece at these points. Bouligand tool paths are used specifically in cement/ceramic deposition AM. Bouligand-inspired AM parts have been observed to behave better than cast elements under mechanical stress.
Pitch Angle
A critical parameter in the development of the Bouligand-inspired tool path is the pitch angle. The pitch angle γ is the angle at which the helicoidal structure is formed. The relative size of the pitch angle is critical for the mechanical response of a Bouligand-inspired AM tool piece. For γ < 45° (small angle), interfacial crack growth and interfacial microcracking is observed. For 45° < γ < 90° (large pitch angle), dominant crack growth through the solid is observed.
Battery Electrodes
Crab shells which already have the Bouligand structure can be used as templates for nanostructured battery electrodes. Crab shells are a low-cost, sustainable alternative to otherwise expensive starting materials and processing methods for nanostructures batteries. The crab shells have a Bouligand structure composed of highly mineralized chitin fibers. The structure can be used as a bio-template to make hollow carbon nanofibers. The desired battery materials, often sulfur and silicon, can be contained in these hollow fibers to create the cathodes and anodes.
Nanocellulose Films
Cellulose nanocrystals self assemble into helicoidal thin films, the pitch angle between the layers can then be modified via solvent processing. The resulting nanocellulose films, which have a Bouligand structure, can be manipulated to achieve various effects on the material properties. These nanocellulose films are impact-resistant, sustainable, and multi-functional and can be used in various applications such as stretchable electronics, protective coatings, eyewear, and body armor.
References
Materials | Bouligand structure | Physics | 3,958 |
68,048,854 | https://en.wikipedia.org/wiki/Emdoor | Emdoor (Chinese: 亿道), with the full name Shenzhen Emdoor Information Co., Ltd., also known as Emdoor Information, is a Chinese provider of rugged mobile computers founded by Zane Zhang in 2008, headquartered in Shenzhen. It is a subsidiary of Emdoor Group, and principally provides rugged tablets, laptops and handheld terminals.
Emdoor is currently a technology ecosystem partner of Microsoft and a partner of Rockchip, as well as a former partner of Electric Cloud.
History
In 2012, Emdoor stepped into the field of rugged tablets, with product lines including rugged phones, tablets and 2-in-1s. Since early 2014, it has collaborated with Intel and become one of the latter's ODM partners in China.
In June 2014, Emdoor joined with Microsoft and Intel to release the EM-I8080, a Windows 8.1 tablet priced at $100. In October, it presented another Windows 8.1 tablet costing around $65 in Hong Kong.
Emdoor cooperated with Microsoft and Intel to unveil a tablet called "EM-i8080" at Computex 2014, which cost just $100.
In 2015, Emdoor worked with Qualcomm and Microsoft to launch Windows 10 Phones in China. In 2020, it rolled out its first 5G rugged tablet.
In April 2016, it was listed on the New Third Board with the stock code , and was delisted on 27 April 2018. The company started IPO counseling, and made a counseling filing with the Shenzhen Securities Regulatory Bureau on December 11, 2020.
References
Chinese brands
Computer companies of China
Computer hardware companies
Computer companies established in 2008
Chinese companies established in 2008 | Emdoor | Technology | 341 |
10,388,995 | https://en.wikipedia.org/wiki/Majority%20problem | The majority problem, or density classification task, is the problem of finding one-dimensional cellular automaton rules that accurately perform majority voting.
Using local transition rules, cells cannot know the total count of all the ones in system. In order to count the number of ones (or, by symmetry, the number of zeros), the system requires a logarithmic number of bits in the total size of the system. It also requires the system send messages over a distance linear in the size of the system and for the system to recognize a non-regular language. Thus, this problem is an important test case in measuring the computational power of cellular automaton systems.
Problem statement
Given a configuration of a two-state cellular automaton with i + j cells total, i of which are in the zero state and j of which are in the one state, a correct solution to the voting problem must eventually set all cells to zero if i > j and must eventually set all cells to one if i < j. The desired eventual state is unspecified if i = j.
The problem can also be generalized to testing whether the proportion of zeros and ones is above or below some threshold other than 50%. In this generalization, one is also given
a threshold ; a correct solution to the voting problem must eventually set all cells to zero if and must eventually set all cells to one if . The desired eventual state is unspecified if .
Approximate solutions
Gács, Kurdyumov, and Levin found an automaton that, although it does not always solve the majority problem correctly, does so in many cases. In their approach to the problem,
the quality of a cellular automaton rule is measured by the fraction of the possible starting configurations that it correctly classifies.
The rule proposed by Gacs, Kurdyumov, and Levin sets the state of each cell as follows. If a cell is 0, its next state is formed as the majority among the values of itself, its immediate neighbor to the left, and its neighbor three spaces to the left. If, on the other hand, a cell is 1, its next state is formed symmetrically, as the majority among the values of itself, its immediate neighbor to the right, and its neighbor three spaces to the right. In randomly generated instances, this achieves about 78% accuracy in correctly determining the majority.
Das, Mitchell, and Crutchfield showed that it is possible to develop better rules using genetic algorithms.
Impossibility of a perfect classifier
In 1995, Land and Belew showed that no two-state rule with radius r and density ρ correctly solves the voting problem on all starting configurations when the number of cells is sufficiently large (larger than about 4r/ρ).
Their argument shows that because the system is deterministic, every cell surrounded entirely by zeros or ones must then become a zero. Likewise, any perfect rule can never make the ratio of ones go above if it was below (or vice versa). They then show that any assumed perfect rule will either cause an isolated one that pushed the ratio over to be cancelled out or, if the ratio of ones is less than , will cause an isolated one to introduce spurious ones into a block of zeros causing the ratio of ones to become greater than .
In 2013, Busic, Fatès, Marcovici and Mairesse gave a simpler proof of the impossibility to have a perfect density classifier, which holds both for deterministic and stochastic cellular and for any dimension.
Exact solution with alternative termination conditions
As observed by Capcarrere, Sipper, and Tomassini, the majority problem may be solved perfectly if one relaxes the definition by which the automaton is said to have recognized the majority. In particular, for the Rule 184 automaton, when run on a finite universe with cyclic boundary conditions, each cell will infinitely often remain in the majority state for two consecutive steps while only finitely many times being in the minority state for two consecutive steps.
Alternatively, a hybrid automaton that runs Rule 184 for a number of steps linear in the size of the array, and then switches to the majority rule (Rule 232), that sets each cell to the majority of itself and its neighbors, solves the majority problem with the standard recognition criterion of either all zeros or all ones in the final state. However, this machine is not itself a cellular automaton. Moreover, it has been shown that Fukś's composite rule is very sensitive to noise and cannot outperform the noisy Gacs-Kurdyumov-Levin automaton, an imperfect classifier, for any level of noise (e.g., from the environment or from dynamical mistakes).
Necessary Conditions for a perfect density classifying cellular Automata
Given that the task had moved from impossible to rather simple depending on the definition of the desired output, the problem was generalised to the following definition: a perfect density classifying automaton is simply defined as an automaton where the set of configurations reachable when the density of the starting configuration is below the threshold is perfectly disjoint with the set of configurations reachable when the density of the starting configuration is above the threshold. Using That definition Capcarrere and Sipper
were able to prove two necessary conditions for a celullar automaton to be a perfect density classifyer: (1) the density of the initial configuration must be conserved over time, and (2) the rule table must exhibit a density of 0.5 (even when the threshold for classification is different from 0.5). That last property is quite unique in the sense that it associates a condition on the form of the rule to a global behaviour.
References
Cellular automata | Majority problem | Mathematics | 1,175 |
15,813,625 | https://en.wikipedia.org/wiki/Conversion%20path | A conversion path is a description of the steps taken by a user of a website towards a desired end from the standpoint of the website operator or marketer. The typical conversion path begins with a user arriving at a landing page or a product page and proceeding through a series of page transitions until reaching a final state, either positive (e.g. purchase) or negative (e.g. abandoned session). In practice, the study of the dynamics of this process by the interested party has evolved into a sophisticated field, where various statistical methods are being applied to the optimization of outcomes. This includes real-time adjustment of presented content, in which a website operator tries to provide deliberate incentives to increase the odds of conversion based on various sources of information, including demographic traits, search history, and browsing events. In practice, this reflects in different content presented to users arriving from online advertising versus search engines, and similarly, different content is presented depending on their demographic segments.
The fundamental metric describing this process in the aggregate is known as conversion rate.
See also
Conversion rate optimization
Conversion funnel
References
Web development | Conversion path | Engineering | 222 |
1,019,095 | https://en.wikipedia.org/wiki/Route%20summit | A route summit is the highest point on a transportation route crossing higher ground. The term is often used in describing railway routes, less often in road transportation. In canal terminology, the highest pound on a route is called the summit pound.
Examples of usage
Rail
Beattock Summit
Stainmore Summit, formerly the second highest railway in England until its closure in 1962
Summit Tank - highest point Unanderra - Moss Vale
Cullerin - highest point Sydney - Albury
Shap
Transport infrastructure | Route summit | Physics | 97 |
71,273,648 | https://en.wikipedia.org/wiki/Ozark%20Highlands%20Spirits | Ozark Highlands Spirits refers to a category of distilled liquor codified by the Missouri General Assembly of the U.S. State of Missouri in 2022. It was signed by the Missouri Governor on July 1, 2022, and became law on August 28, 2022.
History
The Ozark Highlands are known for their limestone bluffs and caves that were used by the early inhabitants as shelters. These first settlers, Paleo-Indians known as Bluff Dwellers, inhabited the region as far back as 12,000 years ago. The first documentation of white settlers in the Ozark Highlands was around 1705. In 1799, Daniel Boone left Kentucky and settled within the northern edge of the Ozark Highlands, in what is today known as Defiance, Missouri.
The history of making spirits, primarily moonshine, is embedded in the history of the Ozark Highlands. In the 18th Century, Irish and Scottish immigrants settled in the region, bringing their distilling skills with them. In order to avoid taxation, distillers hid their production by creating and selling their liquor at night, giving birth to the name moonshine. During prohibition (1920-1933), this moonlight manufacturing actually increased and distilling became a part of the Ozarks culture.
In 2022, a group of consumers and distillers came together to discuss how to codify Ozark Highlands spirits in Missouri law. Today, more than half of the 51 distilleries in Missouri are located in the Ozark Highlands.
Geology & Topography
The Ozark Highlands is a Level III ecoregion designated by the Environmental Protection Agency (EPA) in four U.S. states. Most of the region is within Missouri, with a part in Arkansas and small sections in Oklahoma and Kansas. It is the largest subdivision of the region known as the Ozark Mountains, less rugged in comparison to the Boston Mountains in Arkansas, the highest part of the Ozarks. The Ozarks cover a significant portion of northern Arkansas and most of the southern half of Missouri, extending from Interstate 40 in central Arkansas to Interstate 70 in central Missouri.
The Ozark Highlands ecoregion has been subdivided into eleven Level IV ecoregions, seven of which lie completely within Missouri.
The Ozarks cover nearly , making it the most extensive highland region between the Appalachians and Rockies. Together with the Ouachita Mountains, the area is known as the U.S. Interior Highlands. It is one of nine true highland regions in the world which are distinct for their soils mineral composition and limestone base.
Legislation
The Ozark Highlands Spirits legislation was first introduced in the Missouri House as HB 2621 on February 1, 2022. The House hearing took place on March 21 and was passed by the House Committee on General Laws on March 31, 2022.
During the final days of session in 2022, the "Ozark Highlands Spirits" language was included as a Senate amendment to HB 1738 sponsored by Representative Shamed Dogan. The legislation was passed by the Missouri Senate on May 11, 2022, and was passed by the Missouri House on May 13, 2022, the final day of the 2022 session. It was delivered to Missouri Governor Mike Parson on May 18 and was signed by the Governor on July 1.
The law came into effect on August 28, 2022, and is listed as Missouri Revised Statutes 311.028. The region described as the Ozark Highlands for the purposes of this legislation was drafted by the Missouri Department of Natural Resources, as required by the language of the legislation.
Requirements
Under the new Missouri law, the following requirements must be followed for a distiller to label their spirit as "Ozark Highlands" and sell it in Missouri.
Produced and bottled in the Ozark Highlands
Aged product must be aged in barrels manufactured in Missouri
Whiskey must be aged for a minimum of 4 years
Uses chemical-free water from the Ozark Highlands
Certification
Under Missouri law, any distiller wishing to produce Ozark Highlands Spirits and label them as such for sale in Missouri must have each product initially certified by the Ozark Highland Distillers Guild. The Guild is a non-profit, volunteer-run, 501(c)(3) organization.
References
External links
Ozark Highland Distillers Guild
Distilleries in Missouri
Ozarks
Economy of Missouri
Agriculture in Missouri
Distilled drinks
Highlands | Ozark Highlands Spirits | Chemistry | 885 |
21,091,499 | https://en.wikipedia.org/wiki/Commercial%20Resupply%20Services | Commercial Resupply Services (CRS) are a series of flights awarded by NASA for the delivery of cargo and supplies to the International Space Station (ISS) on commercially operated spacecraft.
The first phase of CRS contracts (CRS-1) were signed in 2008 and awarded $1.6 billion to SpaceX for twelve Dragon 1 and $1.9 billion to Orbital Sciences for eight Cygnus flights, covering deliveries to 2016. The first operational resupply missions were flown by SpaceX in 2012 (CRS SpX-1) and Orbital in 2014 (CRS Orb-1). In 2015, NASA extended CRS-1 to twenty flights for SpaceX and twelve flights for Orbital ATK.
A second phase of contracts (CRS-2) was solicited in 2014. CRS-2 contracts were awarded in January 2016 to Orbital ATK’s continued use of Cygnus, Sierra Nevada Corporation’s new Dream Chaser, and SpaceX’s new Dragon 2, for cargo transport flights beginning in 2019 and expected to last through 2024.
Phase 1 contract awards and demonstration flights
NASA has been directed to pursue commercial spaceflight options since at least 1984, with the Commercial Space Launch Act of 1984 and Launch Services Purchase Act of 1990. By the 2000s funding was authorized for the Commercial Orbital Transportation Services program, followed by the Commercial Crew Development program.
On 23 December 2008, NASA announced the initial awarding of cargo contracts - twelve flights to SpaceX and eight flights to Orbital Sciences Corporation. PlanetSpace, which was not selected, submitted a protest to the Government Accountability Office. On 22 April 2009, the GAO publicly released its decision to deny the protest, allowing the program to continue.
The Antares and Falcon 9 launch vehicles and Cygnus and Dragon cargo spacecraft were developed using Space Act Agreements under NASA's Commercial Orbital Transportation Services (COTS) program.
The first flight contracted by NASA, COTS Demo Flight 1, took place on 8 December 2010, demonstrating a Dragon capsule's ability to remain in orbit, receive and respond to ground commands, and communicate with NASA's Tracking and Data Relay Satellite System. On 15 August 2011, SpaceX announced that NASA had combined the objectives of the COTS Demo Flight 2 and following Flight 3 into a single mission. The rescoped COTS Demo Flight 2 successfully launched on 22 May 2012, delivering cargo to the ISS. The spacecraft reentered on 31 May, landed in the Pacific Ocean, and was recovered, completed CRS certification requirements.
Orbital Sciences first launched the Antares rocket from the Mid-Atlantic Regional Spaceport on 21 April 2013 with a test payload. Orbital Sciences completed the Cygnus Orb-D1 demonstration flight on 29 September 2013, and the operational Cygnus CRS Orb-1 was launched 9 January 2014.
Commercial Resupply Services phase 1
Transport flights began under Commercial Resupply Services phase 1 (CRS-1) in 2012:
Cargo Dragon flights
CRS SpX-1: 8 October 2012
CRS SpX-2: 1 March 2013
CRS SpX-3: 18 April 2014
CRS SpX-4: 21 September 2014.
CRS SpX-5: 10 January 2015
CRS SpX-6: 14 April 2015
CRS SpX-7: attempted on 28 June 2015. Launch failure 139 seconds after lift-off, IDA-1 destroyed. Investigation traced the accident to the failure of a strut inside the second stage's liquid-oxygen tank. NASA concluded that the most probable cause of the strut failure was a design error: instead of using a stainless-steel eye bolt made of aerospace-grade material, SpaceX chose an industrial-grade material without adequate screening and testing and overlooked the recommended safety margin.
CRS SpX-8: 8 April 2016
CRS SpX-9: 18 July 2016
CRS SpX-10: 19 February 2017
CRS SpX-11: 3 June 2017
CRS SpX-12: 14 August 2017
CRS SpX-13: 15 December 2017
CRS SpX-14: 2 April 2018
CRS SpX-15: 29 June 2018
CRS SpX-16: 5 December 2018
CRS SpX-17: 4 May 2019
CRS SpX-18: 25 July 2019
CRS SpX-19: 5 December 2019
CRS SpX-20: 7 March 2020
Cygnus flights
CRS Orb-1: 9 January 2014
CRS Orb-2: 13 July 2014
CRS Orb-3: 28 October 2014 - launch failure, food and care packages for the crew, parts, experiments, and the Arkyd-3 Flight Test (Non-optical) Satellite from Planetary Resources lost.
Following the failure, the Antares 230 system was upgraded with newly built RD-181 first-stage engines to provide greater payload performance and increased reliability. The next two spacecraft were launched on the Atlas V. With the switch to more powerful launch vehicles and the introduction of a larger Enhanced Cygnus, enabled Orbital ATK to cover their initial CRS contracted payload obligation by OA-7.
CRS OA-4: 6 December 2015 - Atlas V, first Enhanced Cygnus
CRS OA-6: 23 March 2016 - Atlas V
CRS OA-5: 17 October 2016 - Antares 230
CRS OA-7: 18 April 2017 - Atlas V
During August 2015, Orbital ATK disclosed that they had received an extension of the resupply program for four extra missions. These flights enable NASA to cover ISS resupply needs until CRS-2 begins.
CRS OA-8E: 12 November 2017.
CRS OA-9E: 21 May 2018.
CRS NG-10: 17 November 2018.
CRS NG-11: 17 April 2019.
CRS Phase 2 solicitation and requirements
NASA began a formal process to initiate Phase 2 of the Commercial Resupply Services, or CRS-2, in early 2014. Later that year, an "Industry Day" was held in Houston, with seven high-level requirements disclosed to interested parties.
Requirements
The contracts were expected to include a variety of requirements:
delivery of approximately per year of pressurized cargo in four or five transport trips
delivery of 24–30 powered lockers per year, requiring continuous power of up to 120 watts at 28 volts, cooling, and two-way communications
delivery of approximately per year of unpressurized cargo, consisting of 3 to 8 items, each item requiring continuous power of up to 250 watts at 28 volts, cooling, and two-way communications
return/disposal of approximately per year of pressurized cargo
disposal of per year of unpressurized cargo, consisting of 3 to 8 items
various ground support services
Proposals
CRS-1 contractors Orbital Sciences and SpaceX each submitted CRS-2 proposals, joined by Sierra Nevada, Boeing, and Lockheed Martin.
SNC's proposal would use a cargo version of its Dream Chaser crew vehicle, the 'Dream Chaser Cargo System'. The proposed cargo Dream Chaser included an additional expendable cargo module for uplift and trash disposal. Downmass would only be provided via the Dream Chaser spaceplane itself. Boeing's proposal likewise used a cargo version of its CST-100 crew vehicle.
Lockheed Martin proposed a new cargo spacecraft called Jupiter, derived from the designs of the NASA's MAVEN and Juno spacecraft. It would have included a robotic arm based on Canadarm technology and a diameter cargo transport module called Exoliner based on the Automated Transfer Vehicle, to be jointly developed with Thales Alenia Space.
Awards
Three companies were awarded contracts on January 14, 2016. Sierra Nevada Corporation's Dream Chaser, the SpaceX Dragon 2, and Orbital ATK Cygnus were selected, each for a minimum of six launches. The maximum potential value of all the contracts was indicated to be $14 billion, but the minimum value is considerably less. CRS-2 launches commenced in 2019 and will extend to at least 2024.
Three more CRS-2 missions for Dragon 2 covering up to CRS-29 were announced in December 2020.
Commercial Resupply Services phase 2 - Awards and flights flown
When NASA issued the Commercial Resupply Services phase 2 (CRS-2) request for proposal (RFP) in September 2014, it received interest from five companies: Lockheed Martin, Boeing, Orbital ATK, Sierra Nevada, and SpaceX. NASA made a competitive range determination to remove Boeing and Lockheed Martin.
Orbital ATK (later purchased by Northrop Grumman), Sierra Nevada, and SpaceX were awarded CRS-2 contracts in January 2016 with initial task orders awarded in June 2016. Each of the three companies is guaranteed at least six cargo missions under the CRS-2 contract. As of December 2017, NASA had awarded $2.6 billion on three contracts with a combined, not-to-exceed value of $14 billion. NASA officials explained that selecting three companies rather than two for CRS-2 increases cargo capabilities and ensures more redundancy in the event of a contractor failure or schedule delay.
The CRS-2 flights commenced in November 2019 with the launch of Cygnus NG-12 mission.
Inside-cargo is typically transported to and from the space station in "the form factor of single Cargo Transfer Bag Equivalent (CTBE) [which is the] unit for size of bag used to transport cargo from visiting vehicles, such as SpaceX Dragon, Northrop Grumman Cygnus, or JAXA H-II Transfer Vehicle (HTV). The bags are sized at and limited in transport mass to each. CTBE units are also used to price, and charge, commercial users of US Orbital Segment stowage space.
Cygnus flights
CRS NG-12: 2 November 2019
CRS NG-13: 15 February 2020
CRS NG-14: 3 October 2020
CRS NG-15: 20 February 2021
CRS NG-16: 10 August 2021
CRS NG-17: 19 February 2022
CRS NG-18: 7 November 2022
CRS NG-19: 2 August 2023
As a result Russia's invasion of Ukraine, Northrop Grumman was left with only two remaining Antares 230+ launch vehicles which were used for the CRS NG-18 and CRS NG-19 missions. Northrop Grumman acquired three flights from SpaceX with the Falcon 9 rocket while a replacement first stage and its engine are developed for its Antares 330 rocket.
CRS NG-20: 30 January 2024
CRS NG-21: 4 August 2024
CRS NG-22: February 2025 (planned)
Northrop Grumman plans to launch further missions using the new Antares 300 series (Antares 330) rockets with booster stage and engines developed by Firefly Aerospace. These missions are also slated to use a new enlarged "Mission B" variant of the Cygnus spacecraft.
CRS NG-23: Late 2025 (planned)
CRS NG-24: Early 2026 (planned)
CRS NG-25: Late 2026 (planned)
Cargo Dragon flights
CRS SpX-21: 6 December 2020
CRS SpX-22: 3 June 2021
CRS SpX-23: 29 August 2021
CRS SpX-24: 21 December 2021
CRS SpX-25: 15 July 2022
CRS SpX-26: 26 November 2022
CRS SpX-27: 14 March 2023
CRS SpX-28: 5 June 2023
CRS SpX-29: 10 November 2023
CRS SpX-30: 21 March 2024
CRS SpX-31: 5 November 2024
CRS SpX-32: March 2025 (planned)
CRS SpX-33: Late 2025 (planned)
CRS SpX-34: Early 2026 (planned)
CRS SpX-35: Late 2026 (planned)
Cargo Dream Chaser flights
SSC Demo-1: 2025 (planned)
CRS SSC-1 to CRS SSC-6: TBA
See also
Cargo spacecraft
Commercial Crew Development (CCDev) – development of crew vehicles
Commercial Orbital Transportation Services
Comparison of space station cargo vehicles
Dream Chaser
Cygnus (spacecraft)
Crew Dragon
Multi-Purpose Logistics Module (STS cargo container)
Commercial Lunar Payload Services
Notes
References
External links
NASA Commercial Crew and Cargo webpage
SpaceX (Space Exploration Technologies Corporation)
OSC (Orbital Sciences Corporation)
CRS contracts and Space Act agreements
Private spaceflight
International Space Station
NASA programs
Spaceflight | Commercial Resupply Services | Astronomy | 2,575 |
42,208,055 | https://en.wikipedia.org/wiki/Manju%20Bansal | Manju Bansal (born. 1 December 1950) has specialized in the field of Molecular biophysics. Currently, she is a professor in theoretical Biophysics group for Molecular Biophysics unit in the Indian Institute of Science, Bangalore. She is the founder director of the Institute of Bioinformatics and Applied Biotechnology at Bangalore.
Education
Bansal did her schooling from Hyderabad and Dehradun. She developed a great interest in Science and later went ahead to earn her BSc and MSc from Osmania University, Hyderabad.
In 1972 she joined the Molecular Biophysics Unit, Indian Institute of Science, Bangalore for her doctoral degree. She got an opportunity to work under the guidance of biophysicist G. N. Ramachandran, on the theoretical modeling of the triple helical structure of the fibrous protein collagen. She received her PhD in 1977.
Thereafter, she continued working at IISc as a post-doctoral fellow on left handed and other unusual structures of DNA till 1981. She then went to Germany as an Alexander von Humboldt Fellow at the European Molecular Biology Laboratory, Heidelberg, for a year and worked on the structure of filamentous phages.
Fellowships
Bansal has been awarded an EMBL Visiting Fellowship and AvH Fellowship, Germany and Senior Fulbright Fellowship, USA. She has been a visiting professor at Rutgers University, US, and visiting consultant at NIH, Bethesda, USA.
Awards and honours
Bansal was awarded the INSA Medal for Young Scientists in 1979.
she is a Fellow of the Indian Academy of Sciences, Bangalore and National Academy of Sciences (India), Prayagraj, since 1998.
References
20th-century Indian physicists
Articles created or expanded during Women's History Month (India) - 2014
1950 births
Living people
Osmania University alumni
Indian Institute of Science alumni
Indian women biologists
Scientists from Uttarakhand
Scientists from Dehradun
Molecular biophysics
20th-century Indian biologists
20th-century Indian women scientists
Women scientists from Uttarakhand | Manju Bansal | Chemistry | 401 |
45,717,790 | https://en.wikipedia.org/wiki/Design-to-cost | Design-to-Cost (DTC), as part of cost management techniques, describes a systematic approach to controlling the costs of product development and manufacturing. The basic idea is that costs are designed "into the product", even from the earliest concept decisions on and are difficult to remove later. These costs are seen as an equally important parameter besides feature scope and schedule, the three taken together yielding the well-known project triangle.
By taking the right design decisions as early as during the initiation and concept phase of the product life-cycle, unnecessary costs at later stages can be avoided. But DTC also tries to capture the necessary measures for cost control during the complete development cycle. In DTC, cost considerations also become part of extended requirements specifications.
In contrast to the closely related target costing, DTC does not mean a product will exactly reach a defined cost, rather, it is about "considering cost as a design parameter in your product development activities". DTC can also be contrasted with Design-to-value which emphasizes the value that can be delivered to the customer, instead of the production costs for the manufacturer or company.
See also
Cost reduction
Total cost of ownership
References
Manufacturing
Product development
Cost engineering | Design-to-cost | Engineering | 243 |
44,976,533 | https://en.wikipedia.org/wiki/Hydnellum%20papuanum | Hydnellum papuanum is a tooth fungus in the family Bankeraceae. Found in Papua New Guinea, it was described as new to science in 1971 by Dutch mycologist Rudolph Arnold Maas Geesteranus.
References
External links
Fungi described in 1971
Fungi of New Guinea
Inedible fungi
papuanum
Fungus species | Hydnellum papuanum | Biology | 65 |
7,617,504 | https://en.wikipedia.org/wiki/Tupolev%20Tu-244 | The Tupolev Tu-244 was a proposed supersonic transport (SST) aircraft, developed from the Tu-144. It implemented novel features such as cryogenic fuel to enable flight distances of up to and would have carried up to 300 passengers. The project was cancelled in 1993.
History
The draft work began in 1979, and when the project ended in 1993 substantial progress had already been made during the interpretation. Specifically, the air resistance in the range of Mach 2 was only 50% higher than a conventional passenger airliner traveling at a speed of Mach 0,9.
The nearly-circular fuselage ( width, height) and the wing unit would have consisted to a large extent of titanium-composite materials. The engines were to be higher performance hydrogen-fuelled versions of the Kuznetsov NK-321 turbofan, used also with the Tu-160. Adjustable air intake ramps from the Tu-160 might have been included. Projected passenger capacity was 311.
Fly-by-wire was intended for flight control. Rather than using a tilting nose, video cameras were to provide the crew with the necessary view for landings.
Specifications
See also
References
.
.
Tu-0244
Supersonic transports
Abandoned civil aircraft projects
Tailless delta-wing aircraft
Quadjets | Tupolev Tu-244 | Physics | 254 |
683,590 | https://en.wikipedia.org/wiki/Microcurrent%20electrical%20neuromuscular%20stimulator | A microcurrent electrical neuromuscular stimulator or MENS (also microamperage electrical neuromuscular stimulator) is a device used to send weak electrical signals into the body. Such devices apply extremely small microamp [uA] electrical currents (less than 1 milliampere [mA]) to the tissues using electrodes placed on the skin. One microampere [uA] is 1 millionth of an ampere and the uses of MENS are distinct from those of "TENS" which runs at one milliamp [mA] or one thousandth of an amp.
Uses
MENS uses include treatments for pain, diabetic neuropathy, age-related macular degeneration, wound healing, tendon repair, plantar fasciitis and ruptured ligament recovery. Most microcurrent treatments concentrate on pain and/or speeding healing and recovery. It is commonly used by professional and performance athletes with acute pain and/or muscle tenderness as it is drug-free and non-invasive, thus avoiding testing and recovery issues. It is also used as a cosmetic treatment.
History
The body's electrical capabilities were studied at least as early as 1830, when the Italian Carlo Matteucci is credited as being one of the first to measure the electrical current in injured tissue. Bioelectricity received less attention after the discovery of penicillin, when the focus of medical research and treatments turned toward the body's chemical processes. Attention began to return to these properties and the possibilities of using very low current for healing in the mid-1900s. In a study published in 1969, for example, a team of researchers led by L.E. Wolcott applied microcurrent to a wide variety of wounds, using negative polarity over lesions in the initial phase, and then alternating application of positive and negative electrodes every three days. The stimulation current ranged from 200 to 800 uA and the treated group showed 200%-350% faster healing rates, with stronger tensile strength of scar tissue and antibacterial effects.
In 1991, the German scientists Drs. Erwin Neher and Bert Sakmann shared the Nobel Prize in Physiology or Medicine for their development of the patch-clamp technique that allows the detection of minute electrical currents through cell membranes. This method allowed the detection of more than 20 different types of ion channel which permit positive or negatively charged ions to cross the cell membrane, confirming that cellular electrical activity is not limited only to nerve and muscle tissues.
Efficacy
A study by a neuroretinologist in the late 1980s suggested that microcurrent stimulation of acupuncture points for the eye had positive effects in slowing and even stopping progression of macular degeneration. This treatment is used to treat both the Wet and Dry forms of AMD. This study was based on Ngok Cheng's research on the increased amounts of ATP levels in living tissue after being stimulated with microcurrent.
Mechanisms of action
While the mechanisms of efficacy are not well established, a few studies have shown that there may be a correlation between the traditional Chinese medical system of acupuncture and microcurrent. A study published in 1975 by Reichmanis, Marino, and Becker concluded in part that. "At most acupuncture points on most subjects, there were greater electrical conductance maxims than at control sites."
Manufacturers
Many companies manufacture microcurrent devices for both professional and personal use, and microcurrent stimulation is used as a "complementary" veterinary modality.
See also
Acupuncture
Electrical muscle stimulation
Electroacupuncture
Macular degeneration
Percutaneous tibial nerve stimulation
TENS
References
Medical equipment
Electrotherapy
Bioelectromagnetic-based therapies | Microcurrent electrical neuromuscular stimulator | Biology | 770 |
40,976,203 | https://en.wikipedia.org/wiki/IRAS%2019475%2B3119 | IRAS 19475+3119 is a protoplanetary nebula in the constellation of Cygnus, 15,000 light-years away. The central star, V2513 Cygni, is an F-type post-AGB star.
The brightest portion of the nebula shows a quadrupolar structure, with elongated bipolar lobes, all surrounded by a faint halo.
The distance is essentially unknown. Assumptions about the luminosity have been used to estimate the distance and other stellar parameters. At an assumed kinematical distance of , the luminosity is and the radius . The star was originally at least and is now . Assuming a luminosity of , the distance becomes . Estimates based on the oxygen spectral line strengths give much higher values luminosities with an absolute magnitude of at least −8.
In 2006, Vera P. Arkhipova et al. announced that IRAS 19475+3119 is a variable star. It was given its variable star designation, V2513 Cygni, in 2013. The star varies from about magnitude 9.33 to 9.50. A primary period of 41 days has been determined, but a slightly shorter secondary period leads to long beats causing variations in the amplitude and apparent period from year to year. The variations are caused by stellar pulsations, with the star being brightest when it is hottest. The temperature varies by up to .
References
F-type supergiants
Post-asymptotic-giant-branch stars
Cygnus (constellation)
Protoplanetary nebulae
Cygni, V2513
Durchmusterung objects
331319
IRAS catalogue objects
Semiregular variable stars
TIC objects | IRAS 19475+3119 | Astronomy | 340 |
297,265 | https://en.wikipedia.org/wiki/Sales%20force%20management%20system | Salesforce management systems (also sales force automation systems (SFA)) are information systems used in customer relationship management (CRM) marketing and management that help automate some sales and sales force management functions. They are often combined with a marketing information system, in which case they are often called CRM systems.
See also
References
Sources
Customer relationship management
Information systems
Personal selling | Sales force management system | Technology | 76 |
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