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78,734,995 | https://en.wikipedia.org/wiki/HD%2092206 | HD 92206 is a Henry Draper Catalogue designation given to a collection of stars in the southern constellation of Carina. It consists of two systems; HD 92206AB, where component A is itself a spectroscopic binary; and the trinary HD 92206C. They are the brightest stars in NGC 3324 and the ionizing stars of the associated emission nebula Gum 31 (IC 2599). The relationship between AB and C is disputed: some state that they are all part of a singular multiple star system, whereas others treat AB and C as neighboring star systems that together "form a compact group." All of their components are young (age ≲1 Myr), massive OB stars near the zero-age main sequence. Two other objects, HD 92206A2 and C2, have been discovered in the immediate vicinity, which are both likely less massive late-type stars based on their X-ray profile.
Stellar components
HD 92206AB
HD 92206A and B comprise a wide binary system, separated by 5".4. They have both been given the spectral type of O6.5V, indicating they are both energetic O-type main-sequence stars each radiating a bolometric luminosity about 170,000 times the Sun's. Despite this, A appears almost a magnitude brighter than B, thus it has been suggested that A could be a spectroscopic binary between two similar O6.5V stars.
In 2014, an X-ray source, designated HD 92206A2, was identified just 0".83 (distance ~1900 AU) from A, which emits hard X-rays i.e., X-rays with a high photon energy at 5.17 keV (wavelength 0.240 nm), as opposed to the soft (low-energy) X-rays released by late O-type stars like A, B, and C. Unless it is highly reddened, this is thought to be a young (~1 Myr old) star with a mass of 0.5–1 , producing X-rays in its corona.
HD 92206C
At a separation of 33" from the AB pair, HD 92206C (alternatively CPD−57° 3580) was first reported to be a spectroscopic binary in 2007, and was further resolved to be a triple system by 2017. Two stars with the spectral types O8V and O9.7V orbit each other with a period of 2.02 days, while a fainter B2-type star orbits them within 1 arcsecond of the inner pair. The brightest of the three has a luminosity 112,000 times that of the Sun (though this was derived from a spectral type of O7.5V rather than O8V). The spectrum of C shows very strong, broad hydrogen lines resembling that of θ1 Orionis C, characteristic of very young stars. The star (or at least one of its components) is known to have a magnetic field.
Simultaneously with the detection of HD 92206A2, another X-ray source, C2, was discovered 1".7 from C, but its closeness to the much brighter C prevented precise measurements. Due to its faintness, it is thought to be a late-type star.
Formation
The location of the HD 92206 system is offset from the center of Gum 31, the nebula from which it formed. To explain this, it has been theorized that the stars were born as two molecular clouds with differing velocities collided at supersonic speeds about one million years ago, which carved a cavity into the center of the nebula and shaped a core that collapsed to form the massive stars.
Bow shock
In 2005, a bow shock was discovered to surround the multiple system. It has a thickness of , extremely thin compared to the bow shocks around other stars reported in the same paper, which are tens or hundreds of AU thick. Due to its great distance from Earth, it has not been fully resolved.
References
Carina (constellation)
Carina Nebula
092206
Durchmusterung objects
O-type main-sequence stars
B-type main-sequence stars
Emission-line stars
Spectroscopic binaries
Triple star systems
Multiple star systems | HD 92206 | [
"Astronomy"
] | 876 | [
"Carina (constellation)",
"Constellations"
] |
78,735,030 | https://en.wikipedia.org/wiki/Atumelnant | Atumelnant (developmental code name CRN04894) is an investigational new drug developed by Crinetics Pharmaceuticals for the treatment of adrenocorticotropic hormone (ACTH)-dependent endocrine disorders. It is a selective antagonist of the melanocortin type 2 receptor (MC2R), also known as the ACTH receptor, which is primarily expressed in the adrenal glands. Atumelnant is being evaluated to treat conditions such as congenital adrenal hyperplasia (CAH) and ACTH-dependent Cushing's syndrome caused for example by pituitary adenomas.
References
Carboxamides
Cyclobutanes
Ethers
Ethoxy compounds
Melanocortin receptor antagonists
Piperazines
Phenols
Pyridines
Quinuclidines
Trifluoromethyl compounds | Atumelnant | [
"Chemistry"
] | 180 | [
"Pharmacology",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Ethers",
"Pharmacology stubs"
] |
78,735,305 | https://en.wikipedia.org/wiki/Gildeuretinol | Gildeuretinol is an investigational new drug being developed by Alkeus Pharmaceuticals for the treatment of retinal diseases, particularly Stargardt disease and geographic atrophy secondary to age-related macular degeneration (AMD). Stargardt disease is caused by a defect in the ABCA4 gene that clears toxic byproducts resulting from the dimerization of vitamin A. Gildeuretinol is a deuterated derivative of Vitamin A that is designed to reduce the dimerization of vitamin A without affecting the visual cycle.
Gildeuretinol has received breakthrough therapy and orphan drug designations from the U.S. Food and Drug Administration.
References
Vitamin A
Deuterated compounds | Gildeuretinol | [
"Chemistry"
] | 147 | [
"Pharmacology",
"Vitamin A",
"Medicinal chemistry stubs",
"Biomolecules",
"Pharmacology stubs"
] |
78,735,907 | https://en.wikipedia.org/wiki/Gauss%20congruence | In mathematics, Gauss congruence is a property held by certain sequences of integers, including the Lucas numbers and the divisor sum sequence. Sequences satisfying this property are also known as Dold sequences, Fermat sequences, Newton sequences, and realizable sequences. The property is named after Carl Friedrich Gauss (1777–1855), although Gauss never defined the property explicitly.
Sequences satisfying Gauss congruence naturally occur in the study of topological dynamics, algebraic number theory and combinatorics.
Definition
A sequence of integers satisfies Gauss congruence if
for every , where is the Möbius function. By Möbius inversion, this condition is equivalent to the existence of a sequence of integers such that
for every . Furthermore, this is equivalent to the existence of a sequence of integers such that
for every . If the values are eventually zero, then the sequence satisfies a linear recurrence.
A direct relationship between the sequences and is given by the equality of generating functions
.
Examples
Below are examples of sequences known to satisfy Gauss congruence.
for any integer , with and for .
for any square matrix with integer entries.
The divisor-sum sequence , with for every .
The Lucas numbers , with and for every .
In dynamical systems
Consider a discrete-time dynamical system, consisting of a set and a map . We write for the th iteration of the map, and say an element in has period if .
Suppose the number of points in with period is finite for every . If denotes the number of such points, then the sequence satisfies Gauss congruence, and the associated sequence counts orbits of size .
For example, fix a positive integer . If is the set of aperiodic necklaces with beads of colors and acts by rotating each necklace clockwise by a bead, then and counts Lyndon words of length in an alphabet of letters.
In algebraic number theory
Gauss congruence can be extended to sequences of rational numbers, where such a sequence satisfies Gauss congruence at a prime if
for every with , or equivalently, if for every .
A sequence of rational numbers defined by a linear recurrence satisfies Gauss congruence at all but finitely many primes if and only if
,
where is an algebraic number field with , and .
See also
Necklace polynomial
Necklace ring
References
Integer sequences
Mathematical theorems | Gauss congruence | [
"Mathematics"
] | 487 | [
"Sequences and series",
"Integer sequences",
"Mathematical structures",
"Recreational mathematics",
"Mathematical objects",
"Combinatorics",
"nan",
"Mathematical problems",
"Mathematical theorems",
"Numbers",
"Number theory"
] |
78,737,233 | https://en.wikipedia.org/wiki/Serge%20Belamant | Serge Belamant is a South African inventor and entrepreneur known for his contributions to cryptography technologies and financial systems. He is the founder of NET1 Technologies (now Lesaka Technologies) and played a significant role in the development of the Chip Offline Pre-authorized Card (COPAC) and the Universal Electronic Payment System (UEPS).
Early life and education
Serge Belamant was born in 1953 and moved to South Africa at the age of 14. In 1972, he enrolled at Witwatersrand University, initially studying engineering before switching to computer science and applied mathematics. After two years, he discontinued his studies and pursued courses in information systems through UNISA (University of South Africa).
Career
In 1989, Serge Belamant developed the Universal Electronic Payment System (UEPS), enabling secure, real-time transactions even in areas with limited connectivity. In the same year, he founded NET1 UEPS Technologies Inc., serving as its CEO and Director.
In 1995, VISA tasked Belamant with designing the Chip Offline Pre-authorized Card (COPAC), a technology still widely used in chip-enabled credit and debit cards. A year later, he listed his company APLITEC (Applied Technology Holdings Limited) on the Johannesburg Stock Exchange.
In 1999, Belamant acquired Cash Payment Services (CPS) from First National Bank of South Africa, modernizing its welfare payment system to serve millions in rural areas.
In 2005, he led NET1 Technologies to an IPO, listing it as NET1 UEPS Technologies Inc. on the Nasdaq. A secondary listing on the Johannesburg Stock Exchange (JSE) followed in 2008.
Under Belamant's leadership, NET1 managed welfare payments for the South African Social Security Agency (SASSA), handling payments for over 10 million beneficiaries monthly. Despite criticism over handling the SASSA contract, investigations by the U.S. Department of Justice and the South African Constitutional Court found no wrongdoing.
Belamant retired in 2017, leaving NET1 with over 10,000 pay points and annual transaction volumes of 160 billion rand—15 to 20% of South Africa's national budget.
In 2018, he co-founded Zilch Technology, a direct-to-consumer ad-subsidized payments network, alongside Philip Belamant and Sean O’Connor.
References
1953 births
Living people
South African inventors
South African businesspeople
Businesspeople in information technology
University of South Africa alumni
South African emigrants
Cryptography | Serge Belamant | [
"Mathematics",
"Engineering"
] | 517 | [
"Applied mathematics",
"Cryptography",
"Cybersecurity engineering"
] |
78,737,317 | https://en.wikipedia.org/wiki/Imocitrelvir | Imocitrelvir is an investigational new drug that is being evaluated for the treatment of viral infections. It is a 3C protease inhibitor in picornaviruses. Originally developed by Pfizer for treating human rhinovirus infections, this small molecule has shown promise against a broader range of viruses, including polioviruses.
References
Antiviral drugs
Amides
Enoic acids
Esters
Isoxazoles
Propargyl compounds
Pyridones
Pyrrolidones | Imocitrelvir | [
"Chemistry",
"Biology"
] | 102 | [
"Pharmacology",
"Antiviral drugs",
"Biocides",
"Esters",
"Functional groups",
"Medicinal chemistry stubs",
"Organic compounds",
"Pharmacology stubs",
"Amides"
] |
78,738,009 | https://en.wikipedia.org/wiki/China%20National%20Clearing%20Center | The China National Clearing Center (CNCC, , ) is a non-profit public institution administered by the People's Bank of China and created in May 1990. It runs several of China's key payment systems.
Specifically, the CNCC operates the China National Advanced Payment System (CNAPS, ), a payment system with two main applications: the High-Value Payment System (HVPS, ), a real-time gross settlement (RTGS) system comparable to Fedwire in the United States or T2 in the euro area; and the Bulk Electronic Payment System (BEPS, ), a retail payment system. The CNCC also operates China's Check Imaging System (CIS), the Internet Banking Payment System (IBPS, ), and the China Foreign Exchange Payment System (CFXPS, ), another RTGS system that specializes in domestic transactions in foreign currencies, previously known in English as China Domestic Foreign Currency Payment System (CDFCPS or FCPS).
The CNCC only operates infrastructures for domestic payments, whether denominated in renminbi (RMB) or in foreign currencies. It thus complements other payments infrastructures that handle foreign exchange and offshore RMB payments, including China UnionPay, CFETS and CIPS; and those that support China's securities and derivatives markets, including CSDC, CCDC and the Shanghai Clearing House.
High-Value Payment System
As China's domestic RTGS system launched in June 2005, the HVPS has been described as "the backbone of the national payments system in China". In 2009, the HVPS processed 247 million transactions amounting to RMB760 trillion; In 2023, these numbers had grown to 382 million transactions and turnover of RMB8,481 trillion.
By end-2010, the HVPS had 1,729 direct participants and 100,510 indirect participants. Bank of China (Hong Kong) and were direct participants of HVPS and are its clearing agents in Hong Kong and Macau respectively. By end-2016, the number of direct participants had shrunk to 305, but that of indirect participants had grown to 141,023.
Bulk Electronic Payment System
The BEPS, launched in June 2006, is a retail payment system which is embedded into the HVPS. It is based on real-time netting and settlement at regular times during the day. In 2009, it processed 226 million transactions amounting to RMB11 trillion. By 2023, these numbers had grown to 4.6 billion transactions and RMB186 trillion.
By end-2010, BEPS had 1,730 direct participants and 100,510 indirect participants, almost exactly overlapping with HVPS with which it shares the CNAPS platform.
Internet Banking Payment System
IBPS started operations in August 2010 and mainly handles instant payment transactions via the internet. It is a deferred net settlement (DNS) system. By end-July 2020, it has 218 direct participants and 175 proxy-access participants. In 2023, it processed 17 billion transactions amounting to RMB301 trillion.
China Domestic Foreign Currency Payment System / China Foreign Exchange Payment System
The CDFCPS, sometimes abbreviated as FCPS, was created in 2008 by the People's Bank of China as a dedicated RTGS system to handle domestic transactions that are entirely denominated in foreign currencies. As of the early 2010s, it handled payments in Australian dollar (AUD), Canadian dollar (CAD), Swiss franc (CHF), euro (EUR), Pound sterling (GBP), Hong Kong dollar (HKD), Japanese yen (JPY), and US dollar (USD). By then, four commercial banks were designated as the system's proxy settlement banks, namely Bank of China, China Construction Bank, Industrial and Commercial Bank of China, and Shanghai Pudong Development Bank. A that time, the overwhelming majority of CDFCPS-settled transactions were in US dollar. The CDFCPS had 31 participants at the end of 2010. Its Chinese name's transcription in English was changed from CDFCPS to CFXPS in the early 2020s.
Domestic foreign-exchange (FX) transactions involving the RMB, by contrast, are not settled on CFXPS but can use the China Foreign Exchange Trade System (CFETS) as clearing house, which in turn uses the HVPS to settle the transactions' RMB legs. Thus, by the early 2010s the CFETS handled most domestic FX transactions. In 2023, CFXPS processed 5 million transactions amounting to USD2.6 trillion (RMB19 trillion).
Check Imaging System
Launched in June 2007, the CNCC's Check Imaging System enables electronic exchange of check images and multilateral net settlement of the corresponding exchange instruments at the HVPS.
See also
Clearing House Automated Transfer System
References
Payment clearing systems
Real-time gross settlement | China National Clearing Center | [
"Technology"
] | 1,011 | [
"Real-time gross settlement"
] |
78,738,102 | https://en.wikipedia.org/wiki/Myerson%20value | The Myerson value is a solution concept in cooperative game theory. It is a generalization of the Shapley value to communication games on networks. The solution concept and the class of cooperative communication games it applies to was introduced by Roger Myerson in 1977.
Preliminaries
Cooperative games
A (transferable utility) cooperative game is defined as a pair , where is a set of players and is a characteristic function, and is the power set of . Intuitively, gives the "value" or "worth" of coalition , and we have the normalization restriction . The set of all such games for a fixed is denoted as .
Solution concepts and the Shapley value
A solution concept – or imputation – in cooperative game theory is an allocation rule , with its -th component giving the value that player receives.A common solution concept is the Shapley value , defined component-wise as
Intuitively, the Shapley value allocates to each how much they contribute in value (defined via the characteristic function ) to every possible coallition .
Communication games
Given a cooperative game , suppose the players in are connected via a graph – or network – . This network represents the idea that some players can communicate and coordinate with each other (but not necessarily with all players), imposing a restriction on which coalliations can be formed. Such overall structure can be represented by a communication game .
The graph can be partitioned into its components, which in turn induces a unique partition on any subset given by
Intuitively, if the coallition were to break up into smaller coallitions in which players could only communicate with each through the network , then is the family of such coallitions.
The communication game induces a cooperative game with characteristic function given by
Definition
Main definition
Given a communication game , its Myerson value is simply defined as the Shapley value of its induced cooperative game :
Extensions
Beyond the main defintion above, it is possible to extend the Myerson value to networks with directed graps. It is also possible define allocation rules which are efficient (see below) and coincide with the Myerson value for communication games with connected graphs.
Properties
Existence and uniqueness
Being defined as the Shapley value of an induced cooperative game, the Myerson value inherits both existence and uniqueness from the Shapley value.
Efficiency
In general, the Myerson value is not efficient in the sense that the total worth of the grand coallition is distributed among all the players:
The Myerson value will coincide with the Shapley value (and be an efficient allocation rule) if the network is connected.
(Component) efficiency
For every coalition , the Myerson value allocates the total worth of the coallition to its members:
Fairness
For any pair of agents such that – i.e., they are able to communicate through the network–, the Myerson value ensures that they have equal gains from bilateral agreement to its allocation rule:
where represents the graph with the link removed.
Axiomatic characterization
Indeed, the Myerson value is the unique allocation rule that satisfies both (component) efficiency and fairness.
Notes
References
Cooperative games
Network theory | Myerson value | [
"Mathematics"
] | 644 | [
"Graph theory",
"Cooperative games",
"Network theory",
"Game theory",
"Mathematical relations"
] |
78,738,320 | https://en.wikipedia.org/wiki/Thurston%27s%2024%20questions | Thurston's 24 questions are a set of mathematical problems in differential geometry posed by American mathematician William Thurston in his influential 1982 paper Three-dimensional manifolds, Kleinian groups and hyperbolic geometry published in the Bulletin of the American Mathematical Society. These questions significantly influenced the development of geometric topology and related fields over the following decades.
History
The questions appeared following Thurston's announcement of the geometrization conjecture, which proposed that all compact 3-manifolds could be decomposed into geometric pieces. This conjecture, later proven by Grigori Perelman in 2003, represented a complete classification of 3-manifolds and included the famous Poincaré conjecture as a special case.
By 2012, 22 of Thurston's 24 questions had been resolved.
Table of problems
Thurston's 24 questions are:
See also
Geometrization conjecture
Hilbert's problems
Taniyama's problems
List of unsolved problems in mathematics
Poincaré conjecture
Smale's problems
References
Geometric topology
Unsolved problems in mathematics | Thurston's 24 questions | [
"Mathematics"
] | 213 | [
"Mathematical problems",
"Unsolved problems in mathematics",
"Topology",
"Geometric topology"
] |
78,739,502 | https://en.wikipedia.org/wiki/Pieter%20Abraham%20van%20de%20Velde | Pieter Abraham van de Velde (22 November 1913 – 10 May 2001) was a Dutch civil engineer and professor of road and hydraulic engineering. He contributed to several major water engineering projects in the Netherlands, notably the drainage of Walcheren at the end of the Second World War, dike restorations following the 1953 North Sea flood, and the Deltaplan.
A proponent of integrating statistical methods into engineering, van de Velde advocated for probabilistic approaches to assess safety and manage uncertainty in the design of flood defences. In his 1980 farewell lecture at Delft University of Technology, he emphasised the limitations of deterministic safety factors and underscored the importance of using probabilistic techniques, such as Monte Carlo simulations, to model risks and failure probabilities in complex systems.
Early life and education
Van de Velde was born on 22 November 1913 in Utrecht. He attended the Hogere Burgerschool and graduated as a civil engineer in 1937 from the Technische Hogeschool Delft. After completing his military service he worked for two years at the Waterloopkundig Laboratorium in Delft, followed by positions at Rijkswaterstaat until 1967.
Career at Rijkswaterstaat
Van de Velde served in various roles at Rijkswaterstaat, including the last six years (1961–1966) as chief engineering director of the (English: Delta Department, North) and the (English: Directorate of Closure Works). During this period, he worked on major projects such as the design and construction of closure dams in Walcheren, the Zuiderzee, and the Delta Works.
Walcheren reclamation (1944–1945)
During the drainage of Walcheren at the end of World War II, van de Velde was part of the engineering team of the (English: Walcheren Reclamation Service), which was led by Pieter Philippus Jansen. Their task involved sealing breaches in the dikes created by Allied bombing. The event was later chronicled in the novel Het verjaagde water by A. den Doolaard, in which van de Velde is portrayed as the character “Schoonebloem".
Repairs following the 1953 North Sea flood
In the aftermath of the North Sea flood of 1953, van de Velde oversaw work to close large dike breaches near the Schelphoek and Ouwerkerk. Van de Velde was appointed as lead engineer for the Schelphoek breach on 27 April 1953, which had become so deep due to strong ebb and flood currents that it could not be closed using traditional methods. Under van de Velde's leadership, a strategy combining innovative engineering and adaptive management was employed. Initial studies examined the hydrodynamic and geological conditions of the site, with extensive tidal calculations and laboratory experiments conducted to assess the forces acting on the breach and predict the behaviour of water flow during the closure process. The dynamic nature of the breach required real-time measurements and adjustments to the proposed solutions.
The construction of a replacement dike was approached in stages, starting with preparatory works to stabilize the surrounding area. The final closure was executed using massive Phoenix caissons, pre-fabricated concrete structures that had previously been used by the Allies in World War II during the Normandy landings, and had been used at Walcheren. The caissons were carefully positioned on a prepared bed of stone and sand, forming a watertight barrier that allowed for the gradual re-establishment of the dike.
Van de Velde also played a significant role in the closure of the breach at Ouwerkerk, which involved the use of 11,500 workers, 4 Phoenix caissons, as well as a number of tugboats and stone dumping vessels. The final caisson was placed on the evening of 6 November 1953, in the presence of Queen Juliana and the Dutch prime minister Willem Drees.
Involvement in the Delta Works
Van de Velde's contributions to the Delta Works included the design of the Haringvlietdam between 1958 and 1970, where he was chief structural engineer for the design of the sluices. For the construction of the Grevelingendam, van de Velde came up with the idea of using a 1.9 kilometre-long cable car system. The advantage of this system in the required gradual vertical closure was that flow velocities were limited, resulting in a reduction in the magnitude of scour holes either side of the dam. Another advantage of the cable car solution was that only a single pylon was required in the centre of the channel. The cable car system was designed by van de Velde and staff at Rijkswaterstaat, in combination with the French company Neyrpic, and used self-propelled cars and a one-way system to optimise capacity.
He later advised on plans for the closure of the Eastern Scheldt, which was accomplished by constructing the (Eastern Scheldt Storm Surge Barrier) between the islands of Schouwen-Duiveland and Noord-Beveland. Spanning nine kilometres, the dam was the largest component of the entire Delta Works.
Originally the dam had been designed, and partly built, as a fully closed structure. However, following public protests from environmental activists and fishing communities, the Den Uyl cabinet decided in 1974 to make major alterations to the project, thereby requiring a partially open design. Such a structure was unprecedented worldwide, with no existing design codes or construction experience to draw upon. An alternative design was subsequently adopted, featuring substantial sluice-gate doors installed along the final four kilometres of the dam. Under normal circumstances, these gates are left open to allow natural tidal movement, but they can be securely closed during adverse weather conditions.
Van de Velde advised the contractor, Dijksbouw Oosterschelde, and liaised with the chief engineer Frank Spaargaren and other key hydraulic engineers such as Jan Agema during the construction. Whilst the innovative design safeguarded the saltwater marine ecosystem, enabled continued fishing activities, and provided effective flood control for the land behind the dam, van de Velde expressed public criticism of the alternative design, believing that the safety risks were too great and the cost estimates for construction too optimistic.
The Oosterscheldekering was completed in 1986 and officially opened by Beatrix of the Netherlands on 4 October that year.
Professor at Delft University of Technology (1966–1980)
From 1966 until his retirement in 1980, Van de Velde was appointed as a professor of civil engineering at the Technische Hogeschool Delft, succeeding Pieter Philippus Jansen. He taught courses, supervised doctoral research, and continued to advise on coastal defences, reclamation projects, and major hydraulic engineering projects in the Netherlands and abroad. He also served on technical advisory committees, including the (English: Technical Advisory Committee on Flood Defences), chairing the group on dike coverings that produced guidelines for using asphalt in hydraulic engineering works.
In 1980, van de Velde delivered his farewell lecture, "Veiligheid en Monte Carlo" (Safety and Monte Carlo), at Delft. The lecture explored the challenges of ensuring safety in civil engineering, particularly in the context of Dutch water management. Van de Velde emphasised the importance of probabilistic methods, such as the Monte Carlo approach, to account for uncertainties in factors like material strength, environmental loads, and design parameters. He reflected on the limitations of deterministic safety factors, advocating for statistical techniques to assess the likelihood of structural failure. Drawing from the history of Dutch flood defences, he highlighted key advances in dike safety after the 1953 disaster, including the integration of statistical insights into design standards.
In particular, van de Velde credited the pioneering work of Pieter Jacobus Wemelsfelder as instrumental in shaping modern approaches to flood defence, noting how a 1938 paper by Wemelsfelder had introduced the application of statistical methods to analyse storm surge heights, challenging the then-standard practice of basing dike heights solely on historical maximum water levels. Van de Velde also acknowledged the work of David van Dantzig on integrating statistical probabilities of extreme water levels with economic considerations, and underscored how this statistical framework allowed for more efficient dike improvements, where modest height increases could drastically reduce failure probabilities, marking a turning point in the Dutch approach to water management.
Honours
Officer of the Order of Orange-Nassau
Selected publications
See also
Delta Works
Flood control in the Netherlands
Grevelingendam
Haringvlietdam
Oosterscheldekering
Rijkswaterstaat
References
Further reading
Various (1981).
Delta Works
Dutch civil engineers
Academic staff of the Delft University of Technology
1913 births 2001 deaths
Delft University of Technology alumni
20th-century Dutch engineers | Pieter Abraham van de Velde | [
"Physics"
] | 1,801 | [
"Physical systems",
"Hydraulics",
"Delta Works"
] |
78,740,295 | https://en.wikipedia.org/wiki/449P/Leonard | 449P/Leonard is a periodic comet that orbits the Sun once every 6.83 years. Studies in 2022 show that 449P was a rediscovery of a previously lost comet that was spotted in 1987.
Discovery and observations
On 29 September 2020, Gregory J. Leonard discovered a new comet about 21.5 in apparent magnitude from images taken from the telescope of the Mount Lemmon Observatory. Orbital calculations showed it had reached its most recent perihelion on 23 November 2020, and it has frequent close passes with Jupiter, where the comet had passed about from the giant planet in 1983, reducing its orbital period from 13.2 years to just 6.82 years.
In 2022, Maik Meyer linked the 449P with the previously lost comet, X/1987 A2, which was discovered by Robert H. McNaught and Malcolm Hartley from the Siding Spring Observatory on 5 January 1987. This precovery image of the comet was not found until March 1987, hence precise follow-up observations were not possible at the time. Subsequently, scientists have also identified P/2013 Y6 as another previous apparition of the comet, which was observed from the Mauna Kea Observatory between 2013 and 2014.
The comet will next return to the inner Solar System on 25 September 2027.
References
External links
Periodic comets
0449
449P
449P
449P
Recovered astronomical objects | 449P/Leonard | [
"Astronomy"
] | 285 | [
"Recovered astronomical objects",
"Astronomical objects"
] |
78,740,968 | https://en.wikipedia.org/wiki/Medog%20Hydropower%20Station | The Medog Hydropower Station () is a planned 60,000 megawatt (MW) hydroelectric dam project under development on the Yarlung Tsangpo river in Tibet Autonomous Region, China. Upon completion, it will become the world's largest hydropower facility, with an anticipated annual power generation capacity of 300 billion kilowatt-hours—triple that of the Three Gorges Dam. The Chinese government authorized the dam's construction in December 2024, with an estimated investment exceeding 1 trillion yuan (approximately US$137 billion). The project is intended to be developed as a single-phase installation, with commercial operations planned for 2033.
Location
The facility is planned to be constructed in Medog County within the Nyingtri Prefecture, situated near the Indian border state of Arunachal Pradesh. The dam site is intended to be located along the lower sections of the Yarlung Tsangpo, which originates in western Tibet's glacial regions. This watercourse continues into India as the Brahmaputra River and into Bangladesh as the Jamuna River, serving as a crucial water source for these regions.
Overview
The Medog Hydropower Station represents part of China's broader hydroelectric development strategy in Tibet. Since 2000, China has initiated or proposed 193 hydropower projects in the region, with approximately 60% still in planning or preparatory phases. As of late 2024, while construction approval has been granted, specific details regarding the project's commencement and completion timeline remain unpublished. The Chinese government has not yet released comprehensive environmental impact assessments or detailed implementation plans for the project.
The project is wholly owned and developed by Power Construction Corporation of China (PowerChina), a state-owned construction enterprise. Commercial operations were planned to begin in 2033. With a projected investment more than quadruple that of the Three Gorges Dam (which cost 250 billion yuan), the Medog Hydropower Station represents one of China's most ambitious infrastructure projects and one of the most expensive infrastructure projects in history. The facility's planned annual power output of 300 billion kilowatt-hours would establish it as the world's most productive hydroelectric installation, significantly surpassing current records.
The project intends to harness a 2,000 meter river elevation drop within a 50-kilometer stretch, granting it the ability to generate significant amounts of hydroelectric power. This section flows through the Yarlung Tsangpo Grand Canyon, recognized as Earth's deepest canyon system. The intended construction plan necessitates the excavation of four 20-kilometer tunnels through Namcha Barwa mountain to divert the Yarlung Tsangpo River.
Criticism
The project has faced resistance from various parties, which include environmental organizations, downstream nations, and Tibetan rights groups. Similar hydroelectric developments in Tibet have previously sparked protests, including recent demonstrations against the Kamtok Dam project on the Drichu/Yangtze River that led to over 1,000 arrests. India and Bangladesh have also voiced apprehension about the project's potential effects on their water resources.
Cultural impact and displacement
Tibetan rights organizations characterized the project as an example of resource exploitation at the expense of Buddhist cultural heritage and local communities.
While specific displacement figures remain undisclosed, the project will necessitate population relocation in the affected area. For comparison, the Three Gorges Dam project resulted in approximately 1.4 million relocations, although the Medog region's lower population density suggests fewer displacements may be required. The development threatens to impact culturally significant sites in what Tibetans consider one of their most sacred regions. According to the International Campaign for Tibet, the 193 combined projects in the region could potentially displace over 1.2 million people and affect numerous religious sites if completed.
Environmental
Environmental organizations have identified several potential ecological consequences of the project. Many expressed concern about project's impact on the Tibetan Plateau's biodiversity. The region that will be impacted by the dam is recognized as one of Tibet's most ecologically diverse areas, leading to fears about ecosystem disruption.
The dam's construction is expected to significantly alter downstream water flow patterns and impact local biodiversity. The project site's location in a seismically active zone prone to landslides has raised additional safety concerns, as the reservoir's water mass could potentially influence geological stability. The steep, narrow topography of the gorge caused geological experts to warn about increased landslide risks. In 2022, engineers from the Sichuan provincial geological bureau specifically highlighted the dangers of "earthquake-induced landslides and mud-rock flows" as significant threats to the project's stability.
Chinese state media has characterized the project as environmentally conscious, emphasizing its role in advancing Beijing's climate neutrality objectives while promoting regional economic development. Chinese officials maintained that the project will have minimal environmental impact, though specific impact assessments remain unpublished.
Water security
The project has generated apprehension among downstream nations regarding water security. Hydrological experts have drawn parallels with China's previous dam projects on the Mekong River, where upstream water control has been associated with increased drought frequency and severity in downstream regions over the past twenty years. Critics noted that India and Bangladesh could face compromised water access, biodiversity disruption, and riverbank erosion akin to those faced by Thailand, Vietnam, and Cambodia from earlier Chinese hydroelectric projects.
A 2020 analysis by the Lowy Institute indicated that China's control over Tibetan Plateau rivers could potentially provide significant geopolitical leverage over India's economy. Indian authorities responded to the project by exploring countermeasures, including the potential development of their own large-scale hydroelectrical dam and reservoir system to mitigate the dam's impacts. The Chinese Ministry of Foreign Affairs asserted in 2020 that China maintains a "legitimate right" to dam the river, stating they have considered downstream effects in their planning.
See also
Three Gorges Dam
List of dams on the Brahmaputra River
References
Dams in China
Hydroelectric power stations in Tibet
Brahmaputra River
Dams on the Brahmaputra River
Reservoirs and dams in Tibet
Dam controversies
China–India relations
Gravity dams
Megaprojects
Dams under construction in China | Medog Hydropower Station | [
"Engineering"
] | 1,217 | [
"Megaprojects"
] |
78,741,791 | https://en.wikipedia.org/wiki/Enerisant | Enerisant is an experimental drug under investigation as a potential treatment for sleep-wake disorders, particularly narcolepsy. It belongs to a histamine H3 receptor antagonist/inverse agonist class of medications.
Pharmacology
Pharmacodynamics
Enerisant functions as a potent and highly selective antagonist/inverse agonist of the histamine H3 receptor. This mechanism of action is similar to that of pitolisant, a currently approved H3 receptor antagonist/inverse agonist for narcolepsy; however, enerisant has demonstrated greater affinity and selectivity for the H3 receptor in preclinical studies. By blocking H3 receptors, enerisant increases histamine release from histaminergic neurons, leading to stimulation of postsynaptic histamine H1 receptors, a key mechanism in promoting wakefulness
Pharmacokinetics
Enerisant exhibits minimal metabolism in humans and is primarily eliminated unchanged via renal excretion. After oral administration, it rapidly absorbs and exhibits dose-dependent plasma concentrations. Within 48 hours, 64.5-89.9% of the administered dose is recovered unchanged in urine. Plasma protein binding is approximately 31.0–31.7% in humans.
References
Antihistamines
Experimental drugs
Carboxamides
Ethers
Morpholines
Phenols
Pyrazoles
Pyrrolidines
H3 receptor antagonists | Enerisant | [
"Chemistry"
] | 289 | [
"Organic compounds",
"Functional groups",
"Ethers"
] |
71,382,836 | https://en.wikipedia.org/wiki/List%20of%20taxa%20named%20after%20human%20genitals | This a list of species, genera, and other biological taxa named after human genitals.
Background
Pubescens. The word originates from the Latin pubes, "adult, full-grown"; "genital area, groin" (e.g., Pubis); "the down or soft hair which begins to grow on young persons when they come to the age of puberty". The use of the term in biology to refer to hairiness or soft down is recorded since 1760 for plants and since 1826 for insects.
Vaginalis. The common specific name is derived from the Latin vagina, originally meaning "sheath, scabbard, covering; sheath of an ear of grain, hull, husk." The specific epithet may refer to a sheathed trait or habit of an organism (e.g. Alysicarpus vaginalis), or may refer to resemblance/relation to the vagina (e.g. Gardnerella vaginalis)
Plants
Families
Orchidaceae. The type genus is Orchis, whose name comes from the Ancient Greek (), literally meaning "testicle", because of the shape of the twin tubers in some species of Orchis.
Genera
Amorphophallus
Clitoria
Orchis
Species
Alysicarpus vaginalis
Baumea vaginalis
Chenopodium vulvaria
Festuca vaginalis
Pontederia vaginalis
Varieties
Capsicum annum annum var. annum 'penis pepper'
Fungi
Orders
Phallales
Families
Phallaceae
Genera
Phallus
Species
Amanita phalloides
Amanita vaginata
Stachybotrys clitoriae
Animals
Genera
Phallichthys. The genus name literally means "phallus (penis) fish", from the Greek phallos meaning "penis" and ichthys meaning "fish", referring to the "comparatively huge" gonopodium, the modified anal fin used for copulation.
Xenophallus. The genus name translates to "strange penis".
Species
Trypauchen vagina
Subspecies
Muntiacus muntjak vaginalis
Animal fossils
Scrotum humanum
References
Taxa
Science-related lists
Human reproductive system | List of taxa named after human genitals | [
"Biology"
] | 452 | [
"Taxa",
"Taxonomy (biology)"
] |
71,383,501 | https://en.wikipedia.org/wiki/Leucocoprinus%20discoideus | Leucocoprinus discoideus is a species of mushroom producing fungus in the family Agaricaceae. In the local language when the mushroom cap is open it is known as batakania or bepokua pembe when it is immature with a closed cap. However 'bepokua' may also be used to refer to other similar looking mushroom species such as Micropsalliota bambusicola.
Taxonomy
It was first described in 1936 by the Belgian mycologist Maurice Beeli who classified it as Lepiota discoidea, whilst illustrations of the mushrooms were produced by Mme M. Goossens-Fontana.
In 1977 it was reclassified by the Belgian mycologist Paul Heinemann who classified it as Leucocoprinus discoideus.
Description
Leucocoprinus discoideus is a small dapperling mushroom with whitish flesh which discolours pinkish brown.
Cap: 3-6cm wide with a white, campanulate (bell shaped) to conical cap and a slight brown umbo. It is covered in small brownish ochre scales which are concentrated on the centre disc or umbo and sparsely scattered on the rest of the cap surface. The cap edges have striations which extend about halfway across the cap. Gills: Free, crowded and white. Stem: 7–8 cm tall and 4–5 mm thick with a hairy (tomentose) coating. It is hollow, white and discolours pale pinkish brown with age. The fragile, membranous stem ring is white and located towards the top of the stem. Spore print: White. Spores: Ellipsoid with a pore. (8.1)9.1–11.3 × (5.7)6.3–7.3 μm. Taste: Bitter. When dry it discolours light brown.
Habitat and distribution
L. discoideus is scarcely recorded and little known. The specimens studied by Heinemann were found in the forest of the Eala region in Zaïre (now the Democratic Republic of the Congo). They were growing in a dense group on a dead tree trunk and on the ground in a dry forest area. Additional specimens were found near Lubumbashi in the South of the country and found growing on decomposing coffee in a plantation near lake Edward and lake Kivu to the North East.
It was also recorded growing in a potted plant in a greenhouse at the Meise Botanic Garden in Belgium.
References
Leucocoprinus
Fungi described in 1977
Fungi of Africa
Taxa named by Paul Heinemann
Taxa named by Maurice Beeli
Fungus species | Leucocoprinus discoideus | [
"Biology"
] | 543 | [
"Fungi",
"Fungus species"
] |
71,383,907 | https://en.wikipedia.org/wiki/Seismic%20wide-angle%20reflection%20and%20refraction | Seismic wide-angle reflection and refraction is a technique used in geophysical investigations of Earth's crust and upper mantle. It allows the development of a detailed model of seismic velocities beneath Earth's surface well beyond the reach of exploration boreholes. The velocities can then be used, often in combination with the interpretation of standard seismic reflection data and gravity data, to interpret the geology of the subsurface.
Theory
In comparison to the typical seismic reflection survey, which is restricted to relatively small incidence angles due to the limited offsets between source and receiver, wide-angle reflection and refraction (WARR) data are acquired with long offsets, allowing the recording of both refracted and wide-angle reflection arrivals.
Acquisition
The acquisition setup depends on the type of seismic source being used and the target of the investigation.
Source
The source of the seismic waves may be either "passive", e.g. naturally occurring sources, such as earthquakes, or anthropogenic sources, such as quarry blasts, or "active", sometimes referred to as "controlled source", e.g. explosive charges set off in shallow boreholes or seismic vibrators onshore or air guns offshore. Exceptionally, the sound waves from nuclear explosions have been used to look at the structure of the upper mantle down to the base of the transition zone at 660 km depth.
Receiver
The sound waves are normally recorded using 3-component seismometers, with ocean-bottom seismometers (OBS) used offshore. The three components allow the recording of S-waves as well as the P-waves that single component instruments can record. The offset range used depends on the depth of the target. For the top few kilometres of the crust, such as when investigating beneath a thick layer of basalt, a range of 10–20 km may be appropriate, while for the lower crust and mantle, offsets greater than 100 km are normally necessary.
Modelling
The processing approach used in standard seismic reflection profiling is not appropriate for wide-angle data. The main modelling approach used for WARR profiles is to match predicted travel times, based on the geology, with those observed in the data. An initial model of variations in seismic velocity is set up, based on whatever knowledge is available from other sources. A ray tracing algorithm is used to calculate the travel times and the model is adjusted iteratively to reduce the misfit between observed and modelled times. Most modelling uses P-waves, but S-waves are also modelled in some cases.
References
Geophysics | Seismic wide-angle reflection and refraction | [
"Physics"
] | 520 | [
"Applied and interdisciplinary physics",
"Geophysics"
] |
71,384,016 | https://en.wikipedia.org/wiki/Leucocoprinus%20elaeidis | Leucocoprinus elaeidis (or elaidis) is a species of mushroom-producing fungus in the family Agaricaceae. In the local language, it is commonly known as elela.
Taxonomy
It was first described in 1927 by the Belgian mycologist Maurice Beeli who classified it as Lepiota elaeidis (or elaidis), whilst illustrations of the mushrooms were produced by Mme M. Goossens-Fontana.
In 1977 it was reclassified by the Belgian mycologist Paul Heinemann who classified it as Leucocoprinus elaeidis.
Description
Leucocoprinus elaeidis is a dapperling mushroom with thin white flesh and stem flesh that may stain yellow.
Cap: 7-12cm wide with thin 2mm thick flesh. The cap is a fluffy white and coated in white flakes or scales whilst the umbo or centre disc is sometimes tinged brown or yellowish. It starts bulbous and cylindrical before expanding to campanulate (bell shaped) and flattening further with age making the umbo more pronounced. There are slight striations at the cap edges. Gills: Free with a collar, crowded and white but yellowing when damaged. Stem: 7-9cm long and 8-12mm thick, expanding at the base to 15-20mm. The stem is hollow and easily detaches from the cap. White and smooth above the stem ring and scaly or flaky white below but staining yellow when touched or damaged. The movable stem ring is white and fluffy at the edges and is located towards the top of the cap (superior or apical). Spore print: White. Spores: Amygdaliform. 8.5-11 x 5.3-7.4 μm. Smell: Pleasant. Taste: Pleasant. When dry the mushroom develops an ochre colour whilst the gills discolour yellowish.
Habitat and distribution
L. elaeidis is scarcely recorded and little known. It grows on the ground and in grass near elaeis, coffee and eucalyptus trees and is sometimes found on rotten wood or compost.
The specimens studied by Beeli were found in groups in the grass at the foot of Elaeis oil palms in the Eala region of the Zaïre (now the Democratic Republic of the Congo). They were also found near lake Edward and lake Kivu to the North East of the country and have been observed in Mali and Senegal.
Similar species
The description and illustrations of L. elaeidis suggest that the species is similar to Leucocoprinus cretaceous which can present with a yellow coloured stem when the white coating is brushed off or Leucocoprinus cepistipes, which can bruise yellow when handled. The illustration and spore size more closely match L. cretaceus so this species may be synonymous with it.
References
Leucocoprinus
Taxa named by Paul Heinemann
Fungi described in 1927
Fungi of Africa
Taxa named by Maurice Beeli
Fungus species | Leucocoprinus elaeidis | [
"Biology"
] | 621 | [
"Fungi",
"Fungus species"
] |
71,385,371 | https://en.wikipedia.org/wiki/19%20Leonis%20Minoris | 19 Leonis Minoris (19 LMi) is a spectroscopic binary located in the northern constellation Leo Minor. It has an apparent magnitude of 5.1, making it one of the brighter members of the constellation. The system is relatively close at a distance of 94 light years but is drifitng closer with a heliocentric radial velocity of .
This spectroscopic binary can be classified as single lined because only the primary's spectrum can be observed clearly, with it having a stellar classification of F6 V. This makes it an ordinary F-type main-sequence star. The companion is probably a G-type main-sequence star of G0, having a mass 101% that of the Sun. The pair have a relatively circular orbit of about 9 days.
19 LMi has 129% the mass of the Sun and an effective temperature of , giving a yellow white hue. The object is somewhat evolved at an age of 2.5 billion years, having a slightly enlarged radius of and a luminosity of , high for its class. 19 LMi has an iron abundance 123% that of the Sun, making it slightly metal enriched. It spins modestly with a projected rotational velocity of .
References
F-type main-sequence stars
G-type main-sequence stars
Spectroscopic binaries
Leo Minor
Leonis Minoris, 19
BD+41 02033
3574
086146
048833
3928 | 19 Leonis Minoris | [
"Astronomy"
] | 294 | [
"Leo Minor",
"Constellations"
] |
71,385,648 | https://en.wikipedia.org/wiki/Tiangong%20censer | The Tiangong censer (Chinese: 天公爐, tian gong lu) is a special type of incense burner used for worshiping the Jade Emperor."Because he is the highest-ranking deity in the deity world, most of the people in Taiwan do not make statues of the deity, but instead use the deity as a representative. When it comes to the shape of censers, people usually think of round tripods with three legs. However, there are also square ones. The design of the censer typically features two dragons grabbing pearls, with patterns of dragons rising or descending on the censer's ears. In the past, most censers were made of stone or iron. Nowadays, it's rare to find large metal censers from before the Japanese rule, as many have been melted down and reused.
Classification
The form of the Tiangong censer may vary depending on the region or location, and is adjusted according to Customs and other factors.
Domestic
Hoklo Taiwanese people hang a censer called Tiangong in the middle of the hall beam in Taiwan. The censer is hung with four chains, which are suspended from the sky and the earth. The four heavenly ministers are in charge of the four directions and seasons.
changed the number of chains from four to three to symbolize inviting the Three Great Emperor-Officials, who are in charge of the three realms of heaven, earth, and water, to pay respect to the Jade Emperor. This is because they believe that only kings could authorize temples to offer sacrifice to heaven in ancient times. The censer used is sometimes called the "Three Realm Furnace" or "Three Realm Gong Furnace".
Taiwan Hakka's Tiangong censer is also known as wall Buddha, sky worship, and Tiangong Pagoda. The incense burner is usually placed on the inside left side of the door or in the recess of the wall pillar, and the words "Jade Emperor's Divine Position" or "Heavenly God's Blessing Incense Position" are written on red paper. It is also said that the Hakka people also called the Tiangong censer as "Sun Gong" or "Sun God", which is a metaphor for "Anti-Qing sentiment". "Since the Hakka ancestors regarded themselves as a Central Plains scholar and considered the Qing dynasty Manchus as a foreign nationality, they placed the Tiangong censer outdoors and worshipped the Sun God in the name of worshipping the Ming dynasty as Han Chinese.
Matsu people who worship gods and ancestors in their homes will put incense burners in front of their doors to worship the gods of heaven. The location is on the left hand side of the doorway, that is, the dragon side of the main door of the residence (dragon side is large) Some shapes also reflect the occupation of the owner, such as fish-shaped incense burners representing fishermen and scroll-shaped incense burners representing public educators; generally, clean iron cans wrapped in red paper are commonly used to nail the sides of the doors or decorated with paper-cut flowers. Before worshipping the gods (or ancestors), incense should be offered to the gods (or ancestors) in order.
In addition, in general, families mainly worship the family gods, so they do not set up a four-legged floor standing censer at home. According to folklore, if you set up such a censer in your home, you are setting up a palace altar for fear of attracting Goryō to your home to seek justice.
Temples
The location and size of the Tiangong censer be changed depending on the building, such as in the courtyard or in front of the pavilion outside the temple, but there are still several common points in their setup.
The Tiangong censer must be set up with the sky in view.
The censer has three feet, symbolizing the triad of Tiger, Horse, and Dog, i.e., the triad of heaven, earth, and man.
Most of the three feet are placed with two feet facing inward and one foot facing outward. see image for demonstration
References
Taiwanese folk religion
East Asian folk religion
Traditional rituals of East Asia
Religious Confucianism
Religious objects | Tiangong censer | [
"Physics"
] | 865 | [
"Religious objects",
"Physical objects",
"Matter"
] |
71,386,879 | https://en.wikipedia.org/wiki/Zirconium%28III%29%20iodide | Zirconium(III) iodide is an inorganic compound with the formula ZrI3.
Preparation
Like other group 4 trihalides, zirconium(III) iodide can be prepared from zirconium(IV) iodide by high-temperature reduction with zirconium metal, although incomplete reaction and contamination of the product with excess metal often occurs.
3 ZrI4 + Zr → 4 ZrI3
An alternative is to crystallise zirconium(III) iodide from a solution of zirconium(III) in aluminium triiodide. The solution is prepared by reducing a eutectic solution of ZrI4 in liquid AlI3 at a temperature of 280–300 °C with metallic zirconium or aluminium.
Structure and bonding
Zirconium(III) iodide has a lower magnetic moment than is expected for the d1 metal ion Zr3+, indicating non-negligible Zr–Zr bonding.
The crystal structure of zirconium(III) iodide is based on hexagonal close packing of iodide ions with one third of the octahedral interstices occupied by Zr3+ ions. The structure consists of parallel chains of face-sharing {ZrI6} octahedra with unequally spaced metal atoms. The Zr–Zr separation alternates between 3.17 Å and 3.51 Å.
ZrCl3, ZrBr3 and ZrI3 adopt structures very similar to the β-TiCl3 structure. In all three ZrX3 there is some elongation of the octahedra along the metal-metal axis, partly due to metal-metal repulsion, but the elongation is most pronounced in the chloride, moderate in the bromide and negligible in the iodide.
References
Zirconium(III) compounds
Iodides
Metal halides | Zirconium(III) iodide | [
"Chemistry"
] | 407 | [
"Inorganic compounds",
"Metal halides",
"Salts"
] |
71,387,813 | https://en.wikipedia.org/wiki/HD%20106315 | HD 106315, or K2-109, is a single star with a pair of close-orbiting exoplanets, located in the constellation of Virgo. Based on parallax measurements, this system lies at a distance of 356 light years from the Sun. At that range, the star is too faint to be seen with the naked eye, as it has an apparent visual magnitude of 8.95. But it is slowly drifting closer with a radial velocity of −3 km/s. , multiplicity surveys have not detected any stellar companions to HD 106315.
The spectrum of HD 106315 presents as an ordinary F-type main-sequence star with a stellar classification of F5V, indicating it is generating energy through hydrogen fusion at its core. It is estimated to be roughly four billion years old but is spinning quickly with a rotation period of 5 days. The star is relatively metal-poor, having 60% of solar concentration of iron. It has only a low level of magnetic activity in its chromosphere, showing a minimal level of star spot coverage. The star has 11% more mass and a 29% larger radius than the Sun. It is radiating 2.4 times the luminosity of the Sun from its photosphere at an effective temperature of 6,300 K.
Planetary system
Two planets were detected by the transit method in 2017, using data from the extended Kepler mission (K2). Their large planetary radii imply both planets have a massive steam atmosphere for planet b and hydrogen-helium atmosphere for planet c. The planetary system of HD 106315 is rather unstable and current planetary orbits are the outcome of violent dynamical history, strongly affected by relativistic effects. The orbits of planets are nearly coplanar, and orbit of c is well aligned with the equatorial plane of the star, misalignment been equal to -10°.
Since 2017, a third outer planet with mass above 45 is suspected to exist in the system.
References
F-type main-sequence stars
Planetary systems with two confirmed planets
Planetary transit variables
Virgo (constellation)
BD+00 2910|
J12135339-0023365
106315 | HD 106315 | [
"Astronomy"
] | 449 | [
"Virgo (constellation)",
"Constellations"
] |
71,388,246 | https://en.wikipedia.org/wiki/Anne-Sophie%20Dielen | Anne-Sophie Dielen is a researcher, scientist communicator and policy maker. Her research focuses on generating and regulating sodium/proton antiporters in plant chloroplasts. She is the Founder of The League of Remarkable Women in Science.
Career
Dielen has a bachelor's degree from the Academy of Montpellier. After completing a PhD in Plant Biology and Biochemistry from the Bordeaux II University in France, Dielen then became a postdoctoral fellow at The Australian National University (ANU) as part of its Realizing Increased Photosynthetic Efficiency research project.
The League of Remarkable Women that she founded, is an interview project featuring women in STEM. It aims at profiling role models for the next generation of female scientists and was first supported by a 2014 ANU Gender Institute grants.
She then became the director of crop biotechnology policy at CropLife Australia.
References
Living people
Year of birth missing (living people)
University of Bordeaux alumni
Academic staff of the Australian National University
Science communicators
Women biochemists
Women biotechnologists | Anne-Sophie Dielen | [
"Chemistry",
"Biology"
] | 211 | [
"Biotechnologists",
"Biochemists",
"Women biotechnologists",
"Women biochemists"
] |
71,388,638 | https://en.wikipedia.org/wiki/Indro%20robot | Indro is a humanoid robot built in India. At , it is the tallest such robot in India.
History
The robot’s creator Santosh Vasudeo Hulawale was inspired by an Indian robot movie that motivated him to building the humanoid robot. He worked on the robot for 5 years. The first version of the robot was introduced to the world in 2016. The robot is made at home using waste materials as well as aluminum, plastic, cardboard, wood, newspapers, and other things readily available in the local market. No 3D-printed components are used and the cost is low.
References
Humanoid robots
2020 in India
Social robots
Robots of India | Indro robot | [
"Technology"
] | 133 | [
"Social robots",
"Computing and society"
] |
71,388,730 | https://en.wikipedia.org/wiki/Gas%20initially%20in%20place | Gas initially in place (GIIP) or original gas in place (OGIP) denote the total estimated quantity (volume) of natural gas contained in a "subsurface" asset prior to extraction (production).
Gas Initially In Place = Gross Rock Volume * Net/Gross * Porosity * average initial Gas Saturation / Formation Volume Factor
References
Petroleum production
Petroleum economics | Gas initially in place | [
"Chemistry"
] | 76 | [
"Petroleum",
"Petroleum stubs"
] |
71,388,879 | https://en.wikipedia.org/wiki/Nanidovirineae | Nanidovirineae is a suborder of viruses in the order Nidovirales, comprising two families.
Hosts
Ghost sharks and the halfbeak Hyporhamphus sajori serve as natural hosts for species in the suborder. Nanidovirineae where found infecting these fishes only in China. Nanidovirineae is distinguished from its sibling suborders mainly by this reliance on fish hosts, although Tobaniviridae also have some fish as natural hosts.
Taxonomy
Families
Nanghoshaviridae
Nanhypoviridae
Sibling suborders
Arnidovirineae
Coronaviridae
Mesnidovirineae
Monidovirineae
Ronidovirineae
Tornidovirineae
References
Nidovirales
Virus suborders | Nanidovirineae | [
"Biology"
] | 162 | [
"Virus stubs",
"Viruses"
] |
71,389,085 | https://en.wikipedia.org/wiki/Marjan%20Pipenbaher | Marjan Pipenbaher (born 22 August 1957) is a Slovenian structural engineer and bridge specialist.
Career
Pipenbaher graduated from the Faculty of Civil Engineering, University of Maribor in 1981. From 1980, he worked at the Gradis Design Office where he participated in designing of several large bridges and viaducts constructed by Gradis. In 1990, he and Viktor Markelj founded Ponting Bridges, a Slovenian studio for structural engineering, focusing mainly on bridge structures, with headquarters in Maribor. The practice is led by Markelj and Pipenbaher, and has constructed many high-profile bridges. Since 2002, he is also founder and CEO of specialized design and research company Pipenbaher Consulting Engineers.
His high-profile bridges include Pelješac Bridge in Croatia (2022), Nissibi Euphrates Bridge in Turkey (2015), and Črni Kal Viaduct in Slovenia (2004). He lives in Slovenska Bistrica.
He is a lecturer at the Faculty of Civil Engineering in Maribor since 2000, in the field of prestressed concrete structures and bridges. He began there as an assistant in 1986.
Major projects
Major projects, by year of completion and ordered by type, are:
Bridges
Carinthian bridge, Maribor, Slovenia (1996)
Črni Kal Viaduct, Slovenia (2004)
Viaduct Bivje, Slovenia (2004)
Millennium Bridge, Podgorica, Montenegro (2006)
Viaduct Bonifika, Koper, Slovenia (2007)
Viaduct Dobruša, Slovenia (2010)
Peračica viaducts, Slovenia (2012)
Giborim bridge, Haifa, Israel (2012)
Nissibi Euphrates Bridge, highway Adiyaman - Diyarbakir, Turkey (2015)
High speed railway bridge no. 10, HSR Tel Aviv - Jerusalem, Israel (2017)
New Kömürhan Bridge, Turkey (2021)
Pelješac Bridge, Croatia (2022)
Pedestrian and cyclist bridges
Footbridge in Ptuj, Slovenia (1997)
Current
Highway bridge and parallel pedestrian bridge over Krka river, Slovenia (detailed design)
Selected works
Awards
2022 Kolos awards for exceptional achievements in civil engineering for the Pelješac Bridge project
2021 The Newspaper Finances' Award for Special Achievements
2019 Jožef Mrak Award for Pelješac Bridge
2019 Honorary City Certificate of Slovenska Bistrica to Dr. Viktor Markelj and Marjan Pipenbaher
2004 UM Award 2004: Golden recognition award to Mr. Marjan Pipenbaher and Mr. Viktor Markelj
1999 Award CSS of CCIS to Footbridge in Ptuj
References
External links
Ponting Bridges Website
Pipenbaher Consulting Engineers Website
1957 births
Living people
Engineers from Ljubljana
People from Slovenska Bistrica
Structural engineers
Viaduct engineers
Bridge engineers | Marjan Pipenbaher | [
"Engineering"
] | 578 | [
"Structural engineering",
"Structural engineers"
] |
71,389,475 | https://en.wikipedia.org/wiki/Viktor%20Markelj | Viktor Markelj (born 1958, Zgornja Bistrica) is a Slovenian structural engineer and bridge specialist.
Career
Markelj graduated from the University of Maribor - Faculty of Civil Engineering in 1982. He obtained a PhD degree in civil engineering at FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture in Maribor in 2016, under the joint supervision of Branko Bedenik and Zlatko Šavor. His doctoral dissertation focused on Innovations in incremental launching method of bridge construction.
From 1981 he worked at Gradis Design Office where he participated in designing of several large bridges and viaducts constructed by Gradis. In 1990, he and Marjan Pipenbaher founded Ponting Bridges, a Slovenian studio for structural engineering, focusing mainly on bridge structures, with headquarters in Maribor. The practice is led by a duo of its founders, dr. Viktor Markelj and Marjan Pipenbaher, and has constructed many high-profile bridges.
His high-profile bridges include Ada Bridge in Belgrade, Serbia (2012), drawbridge in Gdansk, Poland (2017) and Puch Bridge in Ptuj, Slovenia (2007). He lives in Slovenska Bistrica.
He is a lecturer in bridges at the Faculty of Civil Engineering in Maribor since 2003.
Major projects
Major projects, by year of completion and ordered by type, are:
Bridges
Bridge over Mura River, highway Vučja vas - Beltinci, Slovenia (2003)
Puch Bridge, Ptuj, Slovenia (2007)
Viaduct Šumljak, highway Razdrto - Selo, Slovenia (2009)
Viaduct Lešnica North / South, Slovenia (2007/2011)
Ada Bridge, Belgrade, Serbia (2012)
NAR Viaducts, Belgrade, Serbia (2018)
Over- and underpasses
Arch overpass 4-3 in Kozina, Slovenia (1997)
Underpass in Celje, Slovenia (2004)
Overpass 4-6 in Slivnica, Slovenia (2008)
Viaduct/overpass Grobelno, Slovenia (2015)
Pedestrian and cyclist bridges
Footbridge over Soča, Bovec, Slovenia (2007)
Studenci footbridge, Maribor, Slovenia (2007)
Marinič footbridge, Škocjan Caves Park, Slovenia (2010)
Ribja brv, Ljubljana, Slovenia (2014)
Pedestrian and cyclist drawbridge to Ołowianka Island, Gdansk, Poland (2017)
Langur Way Canopy Walk, Penang Hill, Malaysia (2018)
Tremerje Footbridge, Laško, Slovenia (2019)
Tunnels and galleries
Tunnel Malečnik, Maribor, Slovenia (2009)
Arcade gallery Meljski hrib, Maribor, Slovenia (2012)
Current
Ada Huja Bridge, Belgrade, Serbia (preliminary design)
Railway viaduct Pesnica, Slovenia (under construction)
Observation tower Kristal, Rogaška Slatina, Slovenia (under construction)
Selected works
Awards
2019 Honorary City Certificate of Slovenska Bistrica to Dr. Viktor Markelj and Marjan Pipenbaher
2019 Polish Minister of Investment and Development Award to Footbridge to Ołowianka Island in Gdansk
2018 City of Gdansk Award to Footbridge to Ołowianka Island in Gdansk
2015 SCE Award to Viaduct Grobelno
2012 WEF Award to Ada Bridge Belgrade
2012 CES AWARD to Ada Bridge Belgrade
2012 AAB Award to Ada Bridge Belgrade
2011 Footbridge Award to Marinic Bridge
2009 City seal of Maribor to Studenci Footbridge Maribor
2009 Award CSS of CCIS to Studenci Footbridge Maribor
2008 Footbridge Award to Studenci Footbridge Maribor
2007 SCE Award to Puch Bridge over Drava in Ptuj
2004 SCE Award to Bridge over Mura River
2004 UM Award 2004: Golden recognition award to Mr. Marjan Pipenbaher and Mr. Viktor Markelj
References
External links
Ponting Bridges Website
1958 births
Living people
Structural engineers
Viaduct engineers
Bridge engineers | Viktor Markelj | [
"Engineering"
] | 815 | [
"Structural engineering",
"Structural engineers"
] |
71,389,617 | https://en.wikipedia.org/wiki/C11H20O4 | {{DISPLAYTITLE:C11H20O4}}
The molecular formula C11H20O4 (molar mass: 216.27 g/mol) may refer to:
Neopentyl glycol diglycidyl ether
Diethyl diethylmalonate | C11H20O4 | [
"Chemistry"
] | 61 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
71,390,167 | https://en.wikipedia.org/wiki/Leucocoprinus%20citrinellus | Leucocoprinus citrinellus is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1898 by the Argentinian mycologist Carlo Luigi Spegazzini who classified it as Lepiota citrinella.
In 1937 the Austrian-born Brazilian mycologist Johannes Rick described Lepiota citrinella var. serrata which he considered a variant based on the finely serrated gills and cylindrical spores. However this is now also considered a synonym.
The species was reclassified as Leucocoprinus citrinellus in 1987 by the mycologist Jörg Raithelhuber.
In 1932 the Belgian mycologist Maurice Beeli also classified a species as Lepiota citrinella and it was included in an illustrated book in 1936. However, as the name had already been used by Spegazzini, Beeli's classification was illegitimate. This species was later classified as Leucocoprinus beelianus by the Belgian mycologist Paul Heinemann in 1977.
Description
Leucocoprinus citrinellus is a pale yellow dapperling mushroom which may discolour brownish with age.
Cap: Bright yellow with thin, insignificant flesh. Elliptical when immature and 5-7mm wide expanding to 1.5–2 cm wide and flattening as it ages with a 2-3mm wide umbo. The cap surface is covered in small powdery scales with striations that run from the edges to halfway up the cap. Gills: Free, crowded and yellowy white. Stem: 2–4 cm long and 1.5mm thick expanding slightly towards the base which is wider but not bulbous and presents with sparse white, cottony mycelium. The stem surface is yellow white and also powdery or scaly (furfuraceous) and the interior flesh hollows slightly with age. The yellowy white stem ring is thin, membranous and descending. It is persistent but movable and also exhibits scales on the edges. Spores: Ovate or subequilateral. 6 x 4 μm.
Habitat and distribution
L. citrinellus is scarcely recorded and little known. Spegazzini observations were made based on specimens from Argentina whilst Rick's observations were made in the State of Rio Grande do Sul, Brazil. The GBIF only list a small number of observations from Brazil.
References
Leucocoprinus
Fungi of South America
Fungi described in 1898
Taxa named by Carlo Luigi Spegazzini
Fungus species | Leucocoprinus citrinellus | [
"Biology"
] | 523 | [
"Fungi",
"Fungus species"
] |
71,390,999 | https://en.wikipedia.org/wiki/Leucocoprinus%20austrofragilis | Leucocoprinus austrofragilis is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was first described in 1992 by the Australian mycologist John Errol Chandos Aberdeen who classified it as Leucocoprinus austrofragilis.
Description
Leucocoprinus austrofragilis is a cream or very pale brown dapperling mushroom known from Australia.
Cap: 1-2.5cm wide, convex and flattening with membranous flesh. The surface is cream or very light brown with a dark brown umbo at the centre and minute brown scales across the entire surface which quickly vanish. The cap edges have striations. Stem: 3-3.5cm long and 1.5-2mm thick tapering upwards from the 2-3mm thick base. It is smooth and whitish with a slightly brown tint. The membranous stem ring is located below the middle of the stem (inferior) but is not persistent and may vanish. Gills: Free, crowded and white but discolouring slightly when dry. Spore print: Pale whitish, nearly white. Spores: Elliptical with a pore. Dextrinoid. 7-9 x 5.5-6 μm.
Habitat and distribution
L. austrofragilis is scarcely recorded and little known. The specimens studied by Aberdeen were collected by A.B. Cribb in March 1963 who found them growing in grass during wet weather in Brisbane, Queensland, Australia. The GBIF and the Atlas of Living Australia only have the single record submitted by Aberdeen as well as some unconfirmed observations from iNaturalist.
References
Leucocoprinus
Fungi of Australia
Fungi described in 1992
Fungus species | Leucocoprinus austrofragilis | [
"Biology"
] | 355 | [
"Fungi",
"Fungus species"
] |
71,391,476 | https://en.wikipedia.org/wiki/Transition%20metal%20ether%20complex | In chemistry, a transition metal ether complex is a coordination complex consisting of a transition metal bonded to one or more ether ligand. The inventory of complexes is extensive. Common ether ligands are diethyl ether and tetrahydrofuran. Common chelating ether ligands include the glymes, dimethoxyethane (dme) and diglyme, and the crown ethers. Being lipophilic, metal-ether complexes often exhibit solubility in organic solvents, a property of interest in synthetic chemistry. In contrast, the di-ether 1,4-dioxane is generally a bridging ligand.
Bonding, structure, reactions
Ethers are L-type ligands. They are σ-donors that exert weak field ligands. They resemble water ligands as seen in aquo complexes. They do not, however, readily participate in hydrogen bonding. The ether oxygen is nearly trigonal planar in its complexes.
Being weakly basic, ether ligands tend to be easily displaceable. Otherwise, ether ligands are relatively unreactive. Cyclic ethers such as thf can ring-open or even deoxygenated when bound to highly electrophilic metal halides. Thus treatment of tungsten hexachloride with one equivalent of thf gives 1,4-dichlorobutane:
At higher concentrations of thf, polytetrahydrofuran is produced.
Examples
Homoleptic complexes
Ethers are relatively bulky ligands, thus homoleptic (i.e., all ligands being the same) ether complexes are uncommon. Examples often feature weakly coordinating anions such as BArF4− and Al(ORF)4−.
[V(thf)6](BArF4)2
[Mn(thf)6](Mn(CO)5]2
[[Fe(thf)6]][BArF24]2
[Ni(thf)6][Al(ORF)4 ]2
Metal halide complexes
Metal chloride-tetrahydrofuran complexes are especially studied. These compounds are often reagents because they are soluble in organic solvents as well as being anhydrous.
Metal carbonyl complexes
M(CO)5(thf) (M = Cr, Mo, W)
Mo(CO)3(diglyme)
References
Coordination complexes
Ethers | Transition metal ether complex | [
"Chemistry"
] | 498 | [
"Coordination complexes",
"Coordination chemistry",
"Functional groups",
"Organic compounds",
"Ethers"
] |
71,392,160 | https://en.wikipedia.org/wiki/Death%20by%20vending%20machine | Vending machines being rocked or tilted have been known to cause serious injury and death when the heavy machines fall over.
Users may rock machines in order to obtain free products, release stuck products, or obtain change. The U.S. Consumer Product Safety Commission found in a 1995 study that at least 37 deaths and 113 injuries had occurred due to falling vending machines from 1978 to 1995. This resulted in a voluntary campaign from vending machine manufacturers to warn that rocking or tilting the machines could cause serious injury or death, including placing warning labels on all machines.Morford, Mark (18 July 2001). Death By Vending Machine / Warning: Large heavy appliances can be hazardous to your health, San Francisco Chronicle The U.S. military started putting warning labels on machines in the late 1980s after a number of incidents on military installations.
The vast majority of injuries and deaths have happened to men.
The argument that death by a vending machine is more likely to occur than something like winning the Powerball lottery, has drawn more attention to these unusual deaths. One 2012 report states that the odds of winning Powerball are 1 in 175 million, versus 1 in 112 million of getting killed by a vending machine. A similar comparison is often drawn to emphasize the rare occurrence of lethal shark attacks. The deaths have also at times been associated with "Darwin Awards".
In popular culture
In the Snowy Escape expansion pack to life-simulation video game The Sims 4, players can cause the titular characters to violently shake a vending machine, and the characters will be crushed to death if they shake one while already injured.
See also
List of unusual deaths
Suicide booth
References
Causes of death
Vending machines
Injuries | Death by vending machine | [
"Engineering"
] | 339 | [
"Vending machines",
"Automation"
] |
71,392,461 | https://en.wikipedia.org/wiki/PSR%20J0952%E2%80%930607 | PSR J0952–0607 is a massive millisecond pulsar in a binary system, located between from Earth in the constellation Sextans. It holds the record for being the most massive neutron star known , with a mass times that of the Sun—potentially close to the Tolman–Oppenheimer–Volkoff mass upper limit for neutron stars. The pulsar rotates at a frequency of 707 Hz (1.41 ms period), making it the second-fastest-spinning pulsar known, and the fastest-spinning pulsar known within the Milky Way.
PSR J0952–0607 was discovered by the Low-Frequency Array (LOFAR) radio telescope during a search for pulsars in 2016. It is classified as a black widow pulsar, a type of pulsar harboring a closely-orbiting substellar-mass companion that is being ablated by the pulsar's intense high-energy solar winds and gamma-ray emissions. The pulsar's high-energy emissions have been detected in gamma-ray and X-ray wavelengths.
Discovery
PSR J0952–0607 was first identified as an unassociated gamma-ray source detected during the first seven years of the Fermi Gamma-ray Space Telescope's all-sky survey since 2008. Because of its optimal location away from the crowded Galactic Center and its pulsar-like gamma-ray emission peak at 1.4 GeV, it was deemed a prime millisecond pulsar candidate for follow-up. The pulsar was reobserved and confirmed by the Low-Frequency Array (LOFAR) radio telescope in the Netherlands on 25 December 2016, which revealed a 707-Hz radio pulsation frequency alongside radial acceleration by an unseen binary companion. Further LOFAR observations took place from January to February 2017, alongside radio observations by the Green Bank Telescope in Green Bank, West Virginia in March 2017. Optical observations by the 2.54-meter Isaac Newton Telescope on La Palma detected and confirmed the pulsar's companion at a faint apparent magnitude of 23 in January 2017. The discovery was published in The Astrophysical Journal Letters and was announced in a NASA press release in September 2017.
Distance and location
The distance of PSR J0952–0607 from Earth is highly uncertain.
Binary system
The PSR J0952–0607 binary system is composed of a massive pulsar and a substellar-mass (<) companion in close orbit around it. Because of this configuration, this system falls under the category of black widow pulsars that "consume" their companion, by analogy with the mating behavior of the eponymous black widow spider. The companion is continuously losing mass through ablation by intense high-energy solar winds and gamma-ray emissions from the pulsar, which then accretes some of the companion's lost material onto itself.
Companion
The companion orbits the pulsar at a distance of with an orbital period of 6.42 hours. Because it orbits so closely, the companion is presumably tidally locked, with one hemisphere always facing the pulsar. The companion does not appear to eclipse the pulsar, indicating that its orbit is oriented nearly face-on with an inclination of 60° with respect to the plane perpendicular to Earth's line of sight. The companion's orbital motion also does not appear to modulate the pulsar's pulsations, signifying a circular orbit with negligible orbital eccentricity.
The companion was likely a former star that had been reduced to the size of a large gas giant planet or brown dwarf, with a present-day mass of or according to radial velocity measurements. Due to intense irradiation and heating by the host pulsar, the companion's radius is bloated up to 80% of its Roche lobe and brightly glows with a thermal luminosity of about , thereby accounting for much of the system's optical brightness. As a result of bloating, the companion attains a low density likely around (with significant uncertainty due to the system's unknown distance from Earth), making it susceptible to tidal deformation by the pulsar.
The companion's pulsar-facing irradiated hemisphere is continuously heated up to a temperature of , whereas the companion's unirradiated hemisphere experiences a uniform temperature of . This hemispherical temperature difference corresponds to a difference in hemisphere luminosities, which in turn causes significant variability in apparent brightness as the companion rotates around the pulsar. This brightness variability is demonstrated in PSR J0952–0607's optical light curve, which exhibits an amplitude greater than one magnitude.
Mass
PSR J0952–0607 has a mass of , making it the most massive neutron star known . The pulsar likely acquired most of its mass by accreting up to of lost material from its companion.
Rotation and age
PSR J0952–0607 rotates at a frequency of 707 Hz (1.41 ms period), making it the second-fastest-spinning pulsar known, and the fastest-spinning pulsar that is located in the Milky Way. Assuming a standard neutron star radius of , the equator of PSR J0952–0607 rotates at a tangential velocity over —about 14% the speed of light. Based on 7 years of precise pulsation timing data from gamma-ray and radio observations, the pulsar's rotation period is estimated to be slowing down at a spin-down rate less than seconds per second, corresponding to a characteristic age of 4.9 billion years.
Magnetic field
Measurements of PSR J0952–0607's spin-down rate show that the pulsar has a remarkably weak surface magnetic field strength of , placing it among the 10 weakest pulsar magnetic fields known . For context, ordinary pulsar magnetic fields usually lie on the order of teragauss (), over 10,000 times greater than that of PSR J0952–0607. Other millisecond pulsars exhibit similarly weak magnetic fields, hinting at a common albeit unknown mechanism in these types of systems; possible explanations range from accreted matter burying the pulsar's surface magnetic field to heat-driven evolution of the pulsar's solid crust.
Gamma-ray emissions
PSR J0952–0607 appears very faint in gamma-rays and was not detected in July 2011.
See also
Tolman–Oppenheimer–Volkoff limit
Black Widow Pulsar, the prototypical namesake for the class of binary pulsars with ablating companions
PSR J1748−2446ad, the fastest-spinning pulsar located in the globular cluster Terzan 5
Notes
References
Millisecond pulsars
Binary stars
X-ray binaries
Sextans
Astronomical objects discovered in 2016 | PSR J0952–0607 | [
"Astronomy"
] | 1,453 | [
"Sextans",
"Constellations"
] |
71,392,618 | https://en.wikipedia.org/wiki/Macedonian%20Journal%20of%20Chemistry%20and%20Chemical%20Engineering | The Macedonian Journal of Chemistry and Chemical Engineering is a biannual peer-reviewed scientific journal of chemistry established in 1974 by the Society of Chemists and Technologists of Macedonia. Since 2022 it is co-published with the Ss. Cyril and Methodius University of Skopje. It consists of two parts: The first, larger part contains peer-reviewed scientific articles from the various fields of chemistry and chemical engineering, written in English and accompanied by abstracts in Macedonian. The second part, written in Macedonian or in English, contains society and related news.
The journal was first published as the Bulletin of the Chemists and Technologists of Macedonia in 1974, and obtained its current name in 2007. The journal and the articles published since 2006 are available online. It is a diamond open access journal, neither the readers nor the authors pay any fees.
Editors-in-chief
The following persons have been editors-in-chief:
Bojan Šoptrajanov (1974)
Svetomir Hadži-Jordanov (1989)
Gligor Jovanovski (1993)
Maja Cvetkovska (1997)
Trajče Stafilov (2001)
Eleonora Winkelhausen (2005)
Zoran Zdravkovski (2009)
References
External links
Biannual journals
Chemistry journals
Chemical engineering journals
Multilingual journals
Creative Commons Attribution-licensed journals
Ss. Cyril and Methodius University of Skopje | Macedonian Journal of Chemistry and Chemical Engineering | [
"Chemistry",
"Engineering"
] | 286 | [
"Chemical engineering",
"Chemical engineering journals"
] |
71,393,970 | https://en.wikipedia.org/wiki/SW%20Lyncis | SW Lyncis is a binary or possibly a multiple-star system in the northern constellation of Lynx, abbreviated SW Lyn. With a combined apparent visual magnitude of 9.58, it is too faint to be visible to the naked eye. The system is located at a distance of approximately 970 light years based on parallax measurements, and is drifting further away with a net radial velocity of about +32 km/s.
The variable luminosity of this system was reported by R. Kippenhahn in 1955. Huth in 1958 classified it as a β Lyr-type variable. W. Strohmeier found a short period of in 1959, although there was no minimum detected from a secondary eclipse. H. Mauder classified this as an eclipsing binary of the Algol type based on a light curve assembled in 1960. J. K. Gleim in 1967 noted that the period of the system had changed, suggesting that there may be a third body in the system. He considered it to be a member of the β Lyr class, although it is more closely related to the Algol type than W Ursae Majoris variables.
M. Vetešník noted in 1968 that the light curve for the system appeared noticeably asymmetric. He published orbital elements for this system in 1977 and found a stellar classification of F2V for the primary component. A low mass ratio suggested the secondary is much smaller and less luminous than the primary. L. Qingyao and associates in 1991 concluded that this is a semi-detached system with one of the components filling its Roche lobe, and thought the secondary to be over-sized and over-luminous for its mass. W. Ogłoza and associates in 1998 supported the idea of a semi-detached system, and found that the light curve suggested the presence of a third component in the system with an orbital period of . The third component is thought to contribute less than 1.5% of the light output of the system.
In 2010, C.-H. Kim and associates performed modelling of the 34-year cycle variations of the system and conjectured that two additional circumbinary companions are creating this effect. However, subsequent studies suggest that such a configuration would be too unstable. The system behavior remains unexplained. SW Lyn is presently classified as a near contact binary that decreases in brightness to magnitude 10.20 during the primary eclipse and to magnitude 9.65 with the secondary eclipse.
References
Further reading
F-type main-sequence stars
Spectroscopic binaries
Algol variables
Beta Lyrae variables
Lynx (constellation)
Durchmusterung objects
067008
039771
Lyncis, SW | SW Lyncis | [
"Astronomy"
] | 556 | [
"Lynx (constellation)",
"Constellations"
] |
71,395,049 | https://en.wikipedia.org/wiki/HD%20193373 | HD 193373 (HR 7771) is a solitary red hued star located in the equatorial constellation Delphinus. It has an apparent magnitude of 6.21, placing it near the limit for naked eye visibility. Parallax measurements place it 846 light years distant and it is currently receding with a heliocentric radial velocity of .
This is an asymptotic giant branch star with a stellar classification of M1 III. In its current state, the object is fusing hydrogen and helium shells around an inert carbon core. HR 7771 has 177% the mass of the Sun but has expanded to an enlarged radius of . It radiates at 592 times the luminosity of the Sun from its photosphere at an effective temperature of , giving a red hue. HD 193373 has an iron abundance 120% that of the Sun, making it slightly metal enriched.
References
M-type giants
Asymptotic-giant-branch stars
BD+12 04289
193373
100208
7771
Delphinus | HD 193373 | [
"Astronomy"
] | 219 | [
"Delphinus",
"Constellations"
] |
72,907,836 | https://en.wikipedia.org/wiki/Josefa%20Masegosa%20Gallego | Josefa Masegosa Gallego is a Spanish astronomer and scientific researcher. She is a winner of both the Granada, City of Science and Innovation award and the Mariana Pineda Award of Equality.
Life
Gallego was born in 1957 in Oria, Spain. She has a PhD from the University of Granada.
Gallego works in the field of astrophysics. She researches science at the Spanish National Research Council at the Institute of Astrophysics of Andalusia. Her research is mainly focused on formation in intense stars and evolution, formation and nuclear activity in galaxies.
In 2018, she won the Granada, City of Science and Innovation award, and in 2022, she won the Mariana Pineda Award of Equality.
References
Spanish astronomers
Women astronomers
1957 births
Living people
People from Almería
University of Granada alumni
21st-century Spanish women scientists | Josefa Masegosa Gallego | [
"Astronomy"
] | 168 | [
"Women astronomers",
"Astronomers"
] |
72,908,646 | https://en.wikipedia.org/wiki/Sulfur%20dicyanide | Sulfur dicyanide is an inorganic compound with the formula S(CN)2. A white, slightly unstable solid, the compound is mainly of theoretical and fundamental interest given its simplicity. It is the first member of the dicyanosulfanes Sx(CN)2, which includes thiocyanogen ((SCN)2) and higher polysulfanes up to S4(CN)2. According to X-ray crystallography, the molecule is planar, the SCN units are linear, with an S-C-S angle of 95.6°.
Sulfur dicyanide begins to sublime at 30-40 °C and melts at 60 °C. Under an inert atmosphere, it slowly decomposes to a yellow polymer at room temperature with a rate increasing in temperature. The compound is unstable in acid, disproportionating to thiocyanate, cyanate, hydrogen sulfate,and cyanide, and neutral moisture induces decomposition to thiocyanic and cyanic acids. Stable solutions are possible in many organic solvents.
Sulfur dicyanide was first synthesized by Lassaigne in 1828 from silver cyanide and sulfur dichloride. Subsequent developments include Linneman's discovery that the same product arose from silver thiocyanate and cyanogen iodide, and Söderbäck's extensive analysis of reactions between metal cyanides and sulfur halides. Linneman also discovered that sulfur dicyanide reacts with ammonia à la Pinner to give an amidine without displacing the S–C linkage, although dimethylamine induces decomposition to dimethylcyanamide and dimethylammonium thiocyanate.
Sulfur dicyanide generally reacts with noble metals to give heteroleptic cyano-thiocyano complices, although in rare cases it can ligate without decomposition, e.g.:
Ir(CO)(PPh3)2Cl + NCSCN → Ir(CO)(CN)(SCN)(PPh3)2Cl
Ir(N2)(PPh3)2Cl + S(CN)2 → Ir(S(CN)2)(PPh3)2Cl
References
Inorganic carbon compounds
Inorganic sulfur compounds
Inorganic nitrogen compounds
Thiocyanates | Sulfur dicyanide | [
"Chemistry"
] | 491 | [
"Inorganic compounds",
"Functional groups",
"Inorganic nitrogen compounds",
"Inorganic sulfur compounds",
"Inorganic carbon compounds",
"Thiocyanates"
] |
72,909,447 | https://en.wikipedia.org/wiki/Yukaghir%20birch-bark%20carvings | The Yukaghir birch-bark carvings were traditionally drawn by Yukaghir people of Siberia on birch barks for various purposes such as mapping, record-keeping, and party games. Russian writers observed these carvings in the 1890s, and based on their descriptions, several 20th-century scholars misunderstood them to be the examples of a writing system. One particular carving became well-known as the "Yukaghir love letter", but is actually the product of a guessing game.
Types
Three kinds of Yukaghir carvings are known from the accounts of the Russian writers S. Shargorodskii and Vladimir Jochelson:
The so-called "Yukaghir love letters", which are actually product of a guessing game at social gatherings (see below).
Small-scale maps drawn by men to assist in travels for hunting and other purposes. These maps used a limited set of symbols to depict features such as rivers and dwellings, so it appears that the Yukaghir men had established certain mapping conventions.
Depictions of record-keeping: for example, Shargorodskii provides a picture, which according to a Yukaghir man, records that a Yukaghir woman made a shawl for him, and received payment in form of several items such as a comb, tobacco, and buttons.
According to John DeFrancis, the Yukaghir carving is "an example not of writing but of anecdotic art", whose meaning is clear only to someone who is in contact with the creator or another interpreter who understands its meaning.
The so-called "Yukaghir love letter"
A notable example of the Yukaghir carving is a sketch by the Russian writer S. Shargorodskii (1895), reproduced by Gustav Krahmer (1896).
Shargorodskii, a member of the revolutionary group Narodnaya Volya, had been exiled to Siberia by the Tsarist regime. He spent 1892-1893 in the Yukaghir village of Nelmenoye in the Kolyma river area, near the Arctic Ocean. He gained the trust of the local Yukaghir people, and joined them in social activities.
In 1895, Shargorodskii published a 10-page article titled On Yukaghir Writing in the journal Zemlevedenie. Six photographs of the alleged Yukaghir writing system accompanied the article. Shargorodskii obtained the picture of what later came to be known as a "love letter" from a Yukaghir party game, similar to charades or twenty questions. He states that he observed such pictures being made during social gatherings: a young girl would start carving on a fresh birch bark, and the onlookers made guesses about what she was depicting. Eventually, after several incorrect guesses, all the participants in the game would arrive at a common understanding of the picture. Since the participants knew each other well, they could easily deduce the meaning of the carvings; it was not easy for the outsiders to understand the meaning, but Shargorodskii could do so with the help of his Yukaghir acquaintances. According to Shargorodskii, such birch bark carvings were drawn only by young women, and only discussed love lives.
In 1896, General-Major Gustav Krahmer published a translation of Shargorodskii's article in the geographical journal Globus. Shargorodskii had referred to the pictures as "writings" and "figures", but Krahmer presented them as "letters". In 1898, Shargorodskii's friend Vladimir Jochelson, a political exile turned ethnographer, published another example of the Yukaghir carving. Subsequently, several other writers reproduced these pictures. Jochelson wrote that the Yukaghir men often visited the Russian settlement of Srednekolymsk for various purposes; the Yukaghir pictures were expressions of sadness by the jealous Yukaghir girls, who were concerned about losing their lovers to Russian women during such visits.
German writer Karl Weule (1915) published a slightly different version of the Shargorodskii's picture, drawn by the artist Paul Lindner, with the caption "Yukaghir Love Letter" in a popular museum booklet. Thus, Weule appears to have been primarily responsible for promoting the idea that the Yukaghir pictures represent love letters. David Diringer's widely-read book The Alphabet (1948) included an illustration, likely based on Weule's work, with the caption "Sad love-story of a Yukaghir girl". According to one interpretation, the arrow shapes represent four adults and two children. The solid and broken lines connecting the arrows represent current and previous relationships between the adults.
The so-called "Yukaghir love letter" was alleged to be the best example of ideographic picture writing for years. British linguist Geoffrey Sampson (1985) included a modified version of this sketch in his Writing Systems. Sampson described the sketch as a love letter sent by a Yukaghir girl to a young man, presenting it as an example of a semasiographic writing system, which is capable of "communicating its meaning independently of speech".
Although Sampson did not mention his source, American linguist John DeFrancis (1989) traced it to Diringer, and ultimately Shargorodskii. DeFrancis asserted that the pictures were not letters, but the product of a party game, in which young women could publicly express their feelings about love and separation to a small circle of friends in a socially acceptable way. In a Linguistics article, Sampson admitted that the picture was "not an example of 'communication' at all", and that he had taken the picture (and its interpretation) from Diringer.
Apparently unaware of DeFrancis' work, art historian James Elkins (1999) described the Yukaghir pictures as "diagrams of emotional attachments" and "texts, because they tell stories". American linguist J. Marshall Unger dismisses this interpretation as inaccurate.
References
Yukaghir people
Russian folklore
Siberian culture
Pictograms
Betula | Yukaghir birch-bark carvings | [
"Mathematics"
] | 1,274 | [
"Symbols",
"Pictograms"
] |
72,909,998 | https://en.wikipedia.org/wiki/Aluminium%20laurate | Aluminium laurate is an metal-organic compound with the chemical formula . The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid (lauric acid).
Physical properties
Aluminium laurate forms white powder.
Soluble in water.
Use
Aluminium laurate is used as an anticaking agent, free-flow agent, or emulsifier.
References
Laurates
Aluminium compounds | Aluminium laurate | [
"Chemistry"
] | 83 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
72,910,457 | https://en.wikipedia.org/wiki/Highway%20dimension | The highway dimension is a graph parameter modelling transportation networks, such as road networks or public transportation networks. It was first formally defined by Abraham et al. based on the observation by Bast et al. that any road network has a sparse set of "transit nodes", such that driving from a point A to a sufficiently far away point B along the shortest route will always pass through one of these transit nodes. It has also been proposed that the highway dimension captures the properties of public transportation networks well (at least according to definitions 1 and 2 below), given that longer routes using busses, trains, or airplanes will typically be serviced by larger transit hubs (stations and airports). This relates to the spoke–hub distribution paradigm in transport topology optimization.
Definitions
Several definitions of the highway dimension exist. Each definition of the highway dimension uses a hitting set of a certain set of shortest paths: given a graph with edge lengths , let contain every vertex set such that induces a shortest path between some vertex pair of , according to the edge lengths . To measure the highway dimension we determine the "sparseness" of a hitting set of a subset of in a local area of the graph, for which we define a ball of radius around a vertex to be the set of vertices at distance at most from in according to the edge lengths . In the context of low highway dimension graphs, the vertices of a hitting set for the shortest paths are called hubs.
Definition 1
The original definition of the highway dimension measures the sparseness of a hub set of shortest paths contained within a ball of radius :The highway dimension of is the smallest integer such that for any radius and any node there is a hitting set of size at most for all shortest paths of length more than for which .A variant of this definition uses balls of radius for some constant . Choosing a constant greater than 4 implies additional structural properties of graphs of bounded highway dimension, which can be exploited algorithmically.
Definition 2
A subsequent definition of the highway dimension measures the sparseness of a hub set of shortest paths intersecting a ball of radius :The highway dimension of is the smallest integer such that for any radius and any node there is a hitting set of size at most for all shortest paths of length more than and at most for which .This definition is weaker than the first, i.e., every graph of highway dimension also has highway dimension , but not vice versa.
Definition 3
For the third definition of the highway dimension we introduce the notion of a "witness path": for a given radius , a shortest path has an -witness path if has length more than and can be obtained from by adding at most one vertex to either end of (i.e., has at most 2 vertices more than and these additional vertices are incident to ). Note that may be shorter than but is contained in , which has length more than .The highway dimension of is the smallest integer such that for any radius and any node there is a hitting set of size at most for all shortest paths that have an -witness path with .This definition is stronger than the above, i.e., every graph of highway dimension also has highway dimension , but cannot be bounded in terms of .
Shortest path cover
A notion closely related to the highway dimension is that of a shortest path cover, where the order of the quantifiers in the definition is reversed, i.e., instead of a hub set for each ball, there is a one hub set , which is sparse in every ball:Given a radius , an -shortest path cover of is a hitting set for all shortest paths in of length more than and at most . The -shortest path cover is locally -sparse if any node the ball contains at most vertices of , i.e., .Every graph of bounded highway dimension (according to any of the above definitions) also has a locally -sparse -shortest path cover for every , but not vice versa. For algorithmic purposes it is often more convenient to work with one hitting set for each radius , which makes shortest path covers an important tool for algorithms on graphs of bounded highway dimension.
Relation to other graph parameters
The highway dimension combines structural and metric properties of graphs, and is thus incomparable to common structural and metric parameters. In particular, for any graph it is possible to choose edge lengths such that the highway dimension is , while at the same time some graphs with very simple structure such as trees can have arbitrarily large highway dimension. This implies that the highway dimension parameter is incomparable to structural graph parameters such as treewidth, cliquewidth, or minor-freeness. On the other hand, a star with unit edge lengths has highway dimension (according to definitions 1 and 2 above) but unbounded doubling dimension, while a grid graph with unit edge lengths has constant doubling dimension but highway dimension . This means that the highway dimension according to definitions 1 and 2 is also incomparable to the doubling dimension. Any graph of bounded highway dimension according to definition 3 above, also has bounded doubling dimension.
Computing the highway dimension
Computing the highway dimension of a given graph is NP-hard. Assuming that all shortest paths are unique (which can be done by slightly perturbing the edge lengths), an -approximation can be computed in polynomial time, given that the highway dimension of the graph is . It is not known whether computing the highway dimension is fixed-parameter tractable (FPT), however there are hardness results indicating that this is likely not the case. In particular, these results imply that, under standard complexity assumptions, an FPT algorithm can neither compute the highway dimension bottom-up (from the smallest value to the largest) nor top-down (from the largest value to the smallest).
Algorithms exploiting the highway dimension
Shortest path algorithms
Some heuristics to compute shortest paths, such as the Reach, Contraction Hierarchies, Transit Nodes, and Hub Labelling algorithms, can be formally proven to run faster than other shortest path algorithms (e.g. Dijkstra's algorithm) on graphs of bounded highway dimension according to definition 3 above.
Approximations for NP-hard problems
A crucial property that can be exploited algorithmically for graphs of bounded highway dimension is that vertices that are far from the hubs of a shortest path cover are clustered into so-called towns:Given a radius , an -shortest path cover of , and a vertex at distance more than from , the set of vertices at distance at most from according to the edge lengths is called a town. The set of all vertices not lying in any town is called the sprawl.It can be shown that the diameter of every town is at most , while the distance between a town and any vertex outside it is more than . Furthermore, the distance from any vertex in the sprawl to some hub of is at most .
Based on this structure, Feldmann et al. defined the towns decomposition, which recursively decomposes the sprawl into towns of exponentially growing values . For a graph of bounded highway dimension (according to definition 1 above) this decomposition can be used to find a metric embedding into a graph of bounded treewidth that preserves distances between vertices arbitrarily well. Due to this embedding it is possible to obtain quasi-polynomial time approximation schemes (QPTASs) for various problems such as Travelling Salesman (TSP), Steiner Tree, k-Median, and Facility Location.
For clustering problems such as k-Median, k-Means, and Facility Location, faster polynomial-time approximation schemes (PTASs) are known for graphs of bounded highway dimension according to definition 1 above. For network design problems such as TSP and Steiner Tree it is not known how to obtain a PTAS.
For the k-Center problem, it is not known whether a PTAS exists for graphs of bounded highway dimension, however it is NP-hard to compute a ()-approximation on graphs of highway dimension , which implies that any ()-approximation algorithm needs at least double exponential time in the highway dimension, unless P=NP. On the other hand, it was shown that a parameterized -approximation algorithm with a runtime of exists for k-Center where is the highway dimension according to any of the above definitions. When using definition 1 above, a parameterized approximation scheme (PAS) is known to exist when using and as parameters.
For the Capacitated k-Center problem there is no PAS parameterized by and the highway dimension , unless FPT=W[1]. This is notable, since typically (i.e., for all the problems mentioned above), if there is an approximation scheme for metrics of low doubling dimension, then there is also one for graphs of bounded highway dimension. But for Capacitated k-Center there is a PAS parameterized by and the doubling dimension.
External links
Video on "Capacitated k-Center in Low Doubling and Highway Dimension" given by Tung Ahn Vu, 2022.
Video on "Algorithms for Hard Problems on Low Highway Dimension Graphs" given by Andreas Emil Feldmann at ICERM, Brown University, Providence, US, May 2019.
Video on "A (1 + ε)-Embedding of Low Highway Dimension Graphs into Bounded Treewidth Graphs" given by Andreas Emil Feldmann at Hausdorff Institut, Bonn, DE, 2015.
Video on "Highway Dimension: From Practice to Theory and Back" given by Andrew Goldberg
References
Graph theory objects | Highway dimension | [
"Mathematics"
] | 1,931 | [
"Mathematical relations",
"Graph theory",
"Graph theory objects"
] |
72,910,581 | https://en.wikipedia.org/wiki/LFD%20Holding | The LFD Holding is a German piglet production concern based in Genthin in Saxony-Anhalt. It is Germany's largest piglet producer and market leader.
The company was founded in 2004 by Dutchman Adrianus Straathof as Straathof Holding GmbH. In 2014, it was renamed LFD Holding GmbH (LFD standing for Landwirtschaftliche Ferkelzucht Deutschland). In 2020, the company was sold to the Swiss-based investment and holding company Terra Grundwerte AG.
The company has been repeatedly criticized for animal cruelty. In 2021, a major fire completely destroyed the piglet production plant in Alt Tellin.
History
Adrianus Straathof began raising pigs in the Netherlands in 1973. In 2001, Dutch authorities took legal and police action against the farm due to animal cruelty and overcrowding in the stables. After that, Adrianus Straathof expanded to eastern Germany. At the end of 2004, Adrianus Straathof founded Straathof Holding GmbH based in Gladau as an umbrella organization for his various plants in Germany. The Straathof Holding GmbH also opened plants in Hungary.
The company became a pioneer of large-scale animal husbandry in Germany and one of the largest piglet producers in Europe. In doing so, the company repeatedly violated legal requirements and was legally convicted. At the Gladau plant alone, authorities imposed fines amounting to €2.1 million from 2005 to 2014. Subsequently, the company was subjected to protests from local residents, environmentalists as well as animal rights activists.
After the investigative TV magazine Report Mainz reported on animal cruelty in December 2013 with video recordings by the animal rights organization Animal Rights Watch, a three-day raid by police and the public prosecutor's office took place at the Gladau site in 2014. As a result, in November 2014, the responsible district of Jerichower Land issued a nationwide ban on pig keeping and care against Adrianus Straathof, which was unique on this scale in Germany.
After that, the concern was renamed LFD Holding GmbH on December 22, 2014. Adrianus Straathof initially handed over the management to an employee. Finally, on June 4, 2015, Adrianus Straathof announced that Christian Graf Brockdorff and the law firm Schultze & Braun would act as trustees of his ownership. At the same time, an advisory board was established, of which Adrianus Straathof became a member.
On March 18, 2020, Adrianus Straathof sold the concern to the investor Terra Grundwerte AG, based in Switzerland and owned by Schleuniger founder Thomas-Andreas Martin Strehl. Terra Grundwerte AG in turn appointed the Lindhorst Group based in Winsen an der Aller for the operational management. In fiscal year 2020, revenue amounted to €106.873 million, of which roughly 94% (€100.543 million) were generated in Germany and 6% (€6.33 million) in other European countries.
A major fire on March 31, 2021, completely destroyed the piglet production plant in Alt Tellin, resulting in losses of around 20% in the concern's piglet production capacity. The public prosecutor's office estimated the damage at around €40 million.
Structure
The concern keeps sows and produces piglets. The operation of the individual plants is carried out through 14 subsidiaries. The animal stock in the parent farms is 55,000 sows, with which 4000 piglets are produced per day. The piglets are sold to fattening companies in Germany and Europe, some are fattened in the concern's own fattening plants.
For the trade and transport of the animals, the concern cooperates with the Venneker group. With regard to the genetics of the animals, the concern cooperates with the pig breeding company Hypor, a subsidiary of one of the world's largest animal genetics groups Hendrix Genetics.
Controversies
Animal cruelty
The company has been repeatedly criticized for animal cruelty. The animal rights organization Animal Rights Watch has published footage from inside the company's stables on several occasions, causing public criticism. Consequently, the company has been subjected to restraints and fines by authorities.
One major criticism concerned the brutal killings of piglets. In December 2013, Report Mainz reported that piglets were systematically beaten to death in plants of the company in a manner that violated animal welfare. Official police evidence videos from 2014 documented piglets being brutally killed in the carcass box. In 2019, Report Mainz as well as Der Spiegel published footage in cooperation with Animal Rights Watch, which again showed brutal killings of pigs. An employee was subsequently fired and the plant manager was issued a warning.
Another major criticism concerned the company keeping sows in gestation crates too narrowly so that the animals had far too little space. The German Federal Administrative Court ruled that the company's practices were illegal and violated animal welfare.
Technical deficiencies and operational problems
In April 2017, a technical failure led to a fire at the piglet production plant in Kleindemsin, the approximately 260 sows housed there died and damages of €2 to 2.5 million were incurred.
In July 2018, a technical defect led to a fire at the piglet production plant in Gladau, the resulting damage was estimated at €250,000.
In August 2019, there was a leak of high-percentage sulfuric acid at the piglet production plant in Alt Tellin. Later the same month, more than 1,000 piglets died in Alt Tellin due to the failure of a ventilation system. In March 2021, a major fire finally destroyed the entire piglet production plant in Alt Tellin consisting of 18 stables, only 1300 of the 51.000 penned sows and piglets survived. The company was accused of having accepted the death of the animals in case of fire and of not having taken sufficient fire precautions.
References
External links
Pig farming
Intensive farming
Meat companies of Germany
German companies established in 2004
Companies based in Saxony-Anhalt
Jerichower Land | LFD Holding | [
"Chemistry"
] | 1,242 | [
"Eutrophication",
"Intensive farming"
] |
72,910,789 | https://en.wikipedia.org/wiki/Absolutely%20maximally%20entangled%20state | The absolutely maximally entangled (AME) state is a concept in quantum information science, which has many applications in quantum error-correcting code, discrete AdS/CFT correspondence, AdS/CMT correspondence, and more. It is the multipartite generalization of the bipartite maximally entangled state.
Definition
The bipartite maximally entangled state is the one for which the reduced density operators are maximally mixed, i.e., . Typical examples are Bell states.
A multipartite state of a system is called absolutely maximally entangled if for any bipartition of , the reduced density operator is maximally mixed , where .
Property
The AME state does not always exist; in some given local dimension and number of parties, there is no AME state. There is a list of AME states in low dimensions created by Huber and Wyderka.
The existence of the AME state can be transformed into the existence of the solution for a specific quantum marginal problem.
The AME can also be used to build a kind of quantum error-correcting code called holographic error-correcting code.
References
Quantum information science
Quantum states | Absolutely maximally entangled state | [
"Physics"
] | 243 | [
"Quantum states",
"Quantum mechanics"
] |
72,912,536 | https://en.wikipedia.org/wiki/Nine-point%20stencil | In numerical analysis, given a square grid in two dimensions, the nine-point stencil of a point in the grid is a stencil made up of the point itself together with its eight "neighbors". It is used to write finite difference approximations to derivatives at grid points. It is an example for numerical differentiation. This stencil is often used to approximate the Laplacian of a function of two variables.
Motivation
If we discretize the 2D Laplacian by using central-difference methods, we obtain the commonly used five-point stencil, represented by the following convolution kernel:
Even though it is simple to obtain and computationally lighter, the central difference kernel possess an undesired intrinsic anisotropic property, since it doesn't take into account the diagonal neighbours. This intrinsic anisotropy poses a problem when applied on certain numerical simulations or when more accuracy is required, by propagating the Laplacian effect faster in the coordinate axes directions and slower in the other directions, thus distorting the final result.
This drawback calls for finding better methods for discretizing the Laplacian, reducing or eliminating the anisotropy.
Implementation
The two most commonly used isotropic nine-point stencils are displayed below, in their convolution kernel forms. They can be obtained by the following formula:
The first one is known by Oono-Puri, and it is obtained when γ=1/2.
The second one is known by Patra-Karttunen or Mehrstellen, and it is obtained when γ=1/3.
Both are isotropic forms of discrete Laplacian, and in the limit of small Δx, they all become equivalent, as Oono-Puri being described as the optimally isotropic form of discretization, displaying reduced overall error, and Patra-Karttunen having been systematically derived by imposing conditions of rotational invariance, displaying smallest error around the origin.
Desired anisotropy
On the other hand, if controlled anisotropic effects are a desired feature, when solving anisotropic diffusion problems for example, it is also possible to use the 9-point stencil combined with tensors to generate them.
Consider the laplacian in the following form:
Where c is just a constant coefficient. Now if we replace c by the 2nd rank tensor C:
Where c1 is the constant coefficient for the principal direction in x axis, and c2 is the constant coefficient for the secondary direction in y axis. In order to generate anisotropic effects, c1 and c2 must be different.
By multiplying it by the rotation matrix Q, we obtain C', allowing anisotropic propagations in arbitrary directions other than the coordinate axes.
Which is very similar to the Cauchy stress tensor in 2 dimensions. The angle can be obtained by generating a vector field in order to orientate the pattern as desired. Then:
Or, for different anisotropic effects using the same vector field
It is important to note that, regardless of the values of , the anisotropic propagation will occur parallel to the secondary direction c2 and perpendicular to the principal direction c1:. The resulting convolution kernel is as follows
If, for example, c1=c2=1, the cxy component will vanish, resulting in the simple five-point stencil, rendering no controlled anisotropy.
If c2>c1 and =0, the anisotropic effects will be more pronounced in the vertical axis.
if c2>c1 and =45 degrees, the anisotropic effects will be more pronounced in the upper-right / lower-left diagonal.
References
Numerical analysis
Mathematical physics
Computational science
Finite differences
Numerical differential equations
Mathematical analysis
Linear operators in calculus
Non-Newtonian calculus | Nine-point stencil | [
"Physics",
"Mathematics"
] | 788 | [
"Mathematical analysis",
"Calculus",
"Applied mathematics",
"Theoretical physics",
"Computational mathematics",
"Non-Newtonian calculus",
"Finite differences",
"Computational science",
"Mathematical relations",
"Numerical analysis",
"Mathematical physics",
"Approximations"
] |
72,912,618 | https://en.wikipedia.org/wiki/HD%2021693 | HD 21693 is a star in the constellation Reticulum. It has an apparent visual magnitude of 7.94, therefore it is not visible to the naked eye. From its parallax measured by the Gaia spacecraft, it is located at a distance of 108.6 light-years (33.3 parsecs) from Earth.
This is a G-type star with a spectral type of G9IV-V, with features intermediate between main sequence and subgiant. In 2011, the discovery of two Neptune-mass exoplanets around HD 21693 was announced.
Star
This star is classified with a spectral type of G9IV-V, indicating it is a slightly evolved star that is between the main sequence and the subgiant branch. Stellar evolution models suggest that it is right at the end of the main sequence, on the hook before the subgiant turnoff, with a mass of and an age of around 7 billion years, although with a high uncertainty of plus or minus 4 billion years. From its Gaia-measured distance and brightness, it is calculated to have a radius of and a luminosity of . Its effective temperature is 5,430 K and its metallicity, the proportion of elements heavier than helium, and approximately equal to that of the Sun.
HD 21693 exhibits a stellar activity cycle with a period of 10 years, similar to the solar cycle, evidenced by long-term variations in various spectral activity indicators. Its chromospheric activity index varies between −5.02 and −4.83 during the cycle, an amplitude that is similar to that of the Sun's magnetic cycle. This index also shows a weaker variation with a period of 33.5 days, which may correspond to the star's rotation period. The activity cycle also affects the radial velocity of the star, which had to be taken into account when creating the orbital solution of the planets in the system.
HD 21693 has no known companion stars. One observation by the NACO instrument at the Very Large Telescope failed to detect other stars in the system, with a detection limit of at 0.5 arcseconds (16.7 AU).
Planetary system
In 2011 the discovery of two exoplanets orbiting HD 21693 was announced, detected by the radial velocity method using observations taken by the HARPS spectrograph, at the La Silla Observatory. The detailed analysis of the discovery was only published in 2019. The HARPS instrument made 210 measurements of the star's radial velocity between 2003 and 2015, revealing two period signals caused by the gravitational influence of orbiting planets, plus a 10-year signal caused by the star's activity cycle. The planetary signals have no equivalent in the star's spectral activity indicators, which confirms their planetary nature. The radial velocity residuals, after removing all periodic signals, still show higher variability than expected, which can be caused by strong granulation on the star's surface.
The inner planet, HD 21693 b, has a minimum mass of and is the transition regime between super-Earths and Neptune-mass planets. Since the radial velocity method used in its discovery cannot determine the inclination of its orbit, the planet's true mass cannot be determined, although the true mass is usually close to the minimum value. This planet orbits the star at a distance of 0.15 AU with a period of 22.7 days.
The outer planet, HD 21693 c, has a minimum mass of , similar to the mass of Neptune. It is located at a distance of 0.26 AU from the star and has an orbital period of 53.7 days. The planets in the system have a period ratio of 2.37, which is close to a 5:2 commensurability. In one possible formation scenario, they experienced convergent migration shortly after their formation, which trapped them in a 5:2 resonance, but this resonance was lost shortly after the dissipation of the protoplanetary disk.
See also
Stars with planets discovered in the same paper: HD 20003, HD 20781, HD 31527, HD 45184, HD 51608, HD 134060, HD 136352
References
G-type main-sequence stars
G-type subgiants
Reticulum
Durchmusterung objects
021693
016085
Planetary systems with two confirmed planets | HD 21693 | [
"Astronomy"
] | 898 | [
"Reticulum",
"Constellations"
] |
72,912,800 | https://en.wikipedia.org/wiki/CIBERSORT | CIBERSORT, also called CIBERSORTx, is a bioinformatics tool used to deconvolute cell type proportions and gene expression profiles from bulk RNA sequencing datasets. It is among the fastest growing software tools in the life sciences.
References
Biotechnology | CIBERSORT | [
"Chemistry",
"Biology"
] | 57 | [
"Bioinformatics stubs",
"Biotechnology stubs",
"Biotechnology",
"Biochemistry stubs",
"Bioinformatics",
"nan"
] |
72,914,844 | https://en.wikipedia.org/wiki/Scale%20models%20of%20the%20Bastille | Scale models of the Bastille were produced between 1789 and 1790 by the businessman Pierre-François Palloy using stones from the demolition of the Bastille, the building they portray.
History
Following the fall of the Bastille on 14 July 1789 Palloy decided to take charge of its demolition, gaining official authorisation to do so on 16 July and completing work on 21 May 1791. Stones from the former fortress were used on several building projects, notably Pont de la Concorde, but Palloy also converted salvaged stones and other materials into souvenirs, such as stone plaques made from stones from the dungeons, medals made from chains and so on, thus launching a fashion for representations of the fall.
When the 83 départements were founded at the end of 1789 Palloy decided to make a scale model of the Bastille from its stones for each of the départements' capitals. He set up a studio dedicated to producing them, initially carved from the stones, then mass-produced by casting a mix of stone powder and mortar. He offered the scale models to the départements at the end of 1790, sending with them other products and an "apostle of Liberty" (an association set up by Palloy himself), who would give a speech when the gifts were handed over. Scale models were also offered to government ministers, to Louis XVI and to foreign dignitaries such as George Washington (his is still on display at Mount Vernon).
The scale models were around 40 cm high, 100 cm wide and 60 cm deep and were presented to the public at patriotic festivals and contributed to turning the Bastille's fall into a republican myth and symbol of liberty/
Surviving examples
Surviving examples include :
Auch : Archives départementales du Gers
Chartres : Musée des beaux-arts de Chartres
Nancy : Musée lorrain (Palais des Ducs de Lorraine)
Nantes : Musée Dobrée
Pau : Archives départementales des Pyrénées-Atlantiques.
Paris : musée Carnavalet
Paris : Musée des Archives nationales
Quimper : Musée départemental breton
Le Puy-en-Velay : musée Crozatier
Rouen : musée départemental des antiquités
Tours : hôtel Goüin
Tulle: garden of the museum cloister
Valence : musée des beaux-arts
Vannes : Archives départementales du Morbihan
Versailles : salle du Jeu de paume
Vizille : salle de l'été 1789, musée de la Révolution française
Saint-Brieuc : musée d'art et d'histoire de Saint-Brieuc (not on display)
Coutances : Musée Quesnel-Morinière
Bibliography
Jean-Pierre Babelon, 'Les maquettes et les pierres de la Bastille. Récolement des souvenirs lapidaires provenant de l'activité du patriote Pallo', La Gazette des archives, 1965
References
Collection of the Musée Carnavalet
Bastille
Scale modeling | Scale models of the Bastille | [
"Physics"
] | 617 | [
"Scale modeling"
] |
72,917,142 | https://en.wikipedia.org/wiki/Leuprorelin/norethisterone%20acetate | Leuprorelin/norethisterone acetate, also known as leuprolide/norethindrone acetate and sold under the brand name Lupaneta Pack, is a co-packaged medication used to treat endometriosis. It contains leuprorelin as the acetate, a gonadotropin-releasing hormone agonist, and norethisterone acetate, a progestin. The leuprorelin is given by intramuscular injection and the norethisterone acetate is taken by mouth.
The co-packaged medication was approved for medical use in the United States in December 2012.
Medical uses
Leuprorelin/norethisterone acetate is indicated for the initial management of the painful symptoms of endometriosis and for management of recurrence of symptoms.
References
Further reading
Combination drugs
GnRH agonists
Progestogens | Leuprorelin/norethisterone acetate | [
"Chemistry"
] | 185 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
72,917,358 | https://en.wikipedia.org/wiki/Technetium%20%2899mTc%29%20mertiatide | {{DISPLAYTITLE:Technetium (99mTc) mertiatide}}
Technetium (99mTc) mertiatide is a radiopharmaceutical medication used in nuclear medicine to image the kidneys. It is a renal imaging agent that is given by intravenous injection.
It was approved for medical use in the United States in June 1990.
Medical uses
Technetium (99mTc) mertiatide is indicated for use in the diagnosis of congenital and acquired abnormalities, renal failure, urinary tract obstruction, and calculi.
Chemistry
The active ingredient, betiatide, is reconstituted with sodium pertechnetate 99mTc injection to form technetium (99mTc) mertiatide.
References
Radiopharmaceuticals | Technetium (99mTc) mertiatide | [
"Chemistry"
] | 170 | [
"Pharmacology",
"Medicinal radiochemistry",
"Medicinal chemistry stubs",
"Chemicals in medicine",
"Radiopharmaceuticals",
"Pharmacology stubs"
] |
72,918,290 | https://en.wikipedia.org/wiki/Magnesium%20laurate | Magnesium laurate is a metal-organic compound with the chemical formula . The compound is classified as a metallic soap, i.e. a metal derivative of a fatty acid (lauric acid).
Physical properties
Soluble in water.
Uses
Magnesium laurate is used in the food industry as a binder, emulsifier, and anticaking agent.
References
Laurates
Magnesium compounds | Magnesium laurate | [
"Chemistry"
] | 78 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
72,920,262 | https://en.wikipedia.org/wiki/WIMEX%20Group | The WIMEX Group is an internationally active German company in the meat and agricultural industry, based in Köthen, Saxony-Anhalt. With an annual capacity of 435.455 million hatching eggs, it is the largest producer of day-old chicks for chicken fattening in Europe and one of the world's largest suppliers of broiler chickens of the Cobb breed. Its revenue in 2021 was €295,158 million. Just under 50 percent of the company's shares are owned by the PHW Group.
The family-run group of companies consists of 28 individual companies, the parent company being WIMEX Agrarprodukte Import und Export GmbH with administrative headquarters in Regenstauf, Bavaria.
WIMEX has repeatedly come under criticism. Among other things, the company has been accused of animal cruelty and environmental damage.
History
In 1961, the poultry group Lohmann (now PHW Group) started up the broiler hatchery Brüterei Süd in Regenstauf. Gerhard Wagner came to Regenstauf in the course of this as a field representative of Lohmann and later became managing director of the hatchery. In 1985, Wagner finally founded the WIMEX Agrarprodukte Import und Export GmbH 1985 in Regenstauf for the production of hatching eggs. In the 1990s, the company expanded into Eastern Germany. There, the company invested extensively in agricultural land, making it one of the larger investors in the agricultural land market in the new states of Germany.
In 1998, WIMEX took over the distribution of the Cobb breeding line under the name Cobb Germany as a franchisee of the international breeding company Cobb-Vantress (part of Tyson Foods). From 2005 onwards, WIMEX expanded into the Netherlands. In 2017, WIMEX opened two newly built hatcheries, in Elsnigk as well as Vreden.
The company's founder Gerhard Wagner presided over the operational management from 1985 to 2019. Since then, the company has been managed by three managing directors: Ulrich Wagner, Leopold Graf von Drechsel and Ralph Weickert.
In 2020, WIMEX founded the joint venture WIMEX & Friends Energy GmbH & Co. KG with the Freitag Group for the construction of photovoltaic systems on stables.
In March 2021, H5N8 avian influenza broke out at a WIMEX farm in Nittenau, Bavaria. As a result, around 52,000 animals were culled by gathering them in containers and subsequent flooding. A restricted area was established around the WIMEX farm, and restocking of the barn was officially prohibited for 21 days. It remained unclear whether the virus was introduced via a wild bird, due to poor hygiene, or through contaminated feed.
Shareholders
The largest shareholder, with a stake of 49.25%, is the Wagner Family Foundation based in Regenstauf. The PHW Group, the largest company in the German poultry industry, is the second-largest shareholder, with a stake of 48.76%. The other shares belong to WIMEX Agrarprodukte Import und Export GmbH itself as well as to the founder Gerhard Wagner (0.49%).
Structure
The poultry division makes up the largest business unit with €215,998 million and 73.18% of total sales. In addition, the company is active in agriculture (€78.317 million, or 26.53%) and fodder production (€0.843 million, or 29%).
Poultry
Poultry is the core business area of WIMEX with a highly developed vertical integration: the company keeps grandparent as well as parent stock, operates hatcheries, sells day-old chicks and fattens chicken itself, produces feed and processes it in its own feed plants.
For grandparenting, WIMEX has 36 farms in Germany, producing 10 million chickens of the Cobb breed annually. For parenting, the company runs 97 farms. To hatch the hatching eggs, the company runs a number of hatcheries. Day-old chicks are marketed internationally. Important customers are the PHW Group, Plukon and the Sprehe Group.
The company also operates chicken fattening plants. The 6 fattening facilities have a capacity for 830,790 chickens and produce 8 million broilers annually.
WIMEX has a 40.83% stake in Cobb Espanola SA and a 50% stake in Cobb Russia. Cobb Russia supplies Russia's largest poultry meat producer Cherkizovo, among others.
Agriculture
WIMEX owns more than 8000 hectares of arable land for feed cultivation using conventional farming methods. Most of the cultivation is carried out by the subsidiary Agrargesellschaft Wulfen mbH. The produce, mainly grain and corn, is used for the group's internal feed supply.
Furthermore, WIMEX cultivates vegetables on 800 hectares. WIMEX markets the produce, including radishes and carrots, under the brand Bördegarten Gemüse.
Other activities
Managing director Gerhard Wagner was president of the lobby organisation Zentralverband der Deutschen Geflügelwirtschaft (Central Association of the German Poultry Industry, ZDG) from 2001 to 2011. From 2011 to 2016, managing director Leopold Graf von Drechsel was president of the ZDG and on the executive committee of the Arbeitsgemeinschaft Deutscher Tierzüchter (Association of German Animal Breeders).
Awards
WIMEX founder Gerhard Wagner received the Federal Cross of Merit in 2013 for his contribution to the integration of the two German states after reunification.
Controversies
Environmental damage
WIMEX has repeatedly been accused of being responsible for environmental damage due to high ammonia emissions. According to the Heinrich Böll Foundation's meat atlas (Fleischatlas), WIMEX was one of the largest emitters of ammonia in Mecklenburg-Western Pomerania, contributing to the acidification of soils, the overfertilization of groundwater and the formation of health-damaging particulate matter.
In 2017, the research organization Correctiv published a data analysis according to which the nitrate content of the groundwater around the WIMEX farms in and around Baasdorf exceeded the limit value by almost double.
Animal cruelty
In 2010, ARD magazin Report Mainz broadcast footage published by the animal rights organization PETA of a parent-animal farm in Natenstedt, Lower Saxony, which showed chickens being kicked and thrown several meters against walls. The parent-animal farm was a WIMEX contract producer, and the buyer of the hatching eggs was the PHW Group subsidiary Wiesenhof. Peta criticized the conditions as massive animal welfare violations. The PHW Group admitted that the recordings showed animal cruelty, the conditions were inexcusable and not compatible with the animal welfare guidelines for parent animal farms. According to PHW Group, these were individual cases, the company had drawn personal consequences.
In 2016, the television magazine Panorama broadcast footage published by the animal rights organization Animal Rights Watch (ARIWA) of animal farms run by leading officials of German agricultural associations. Among them were parent-animal farms run by WIMEX, whose CEO Graf von Drechsel was president of the Zentralverband der Deutschen Geflügelwirtschaft at the time. ARIWA spoke of massive animal welfare violations. Von Drechsel confirmed that the footage came from WIMEX farms and that back and shoulder injuries had been poorly treated.
In 2017, the television magazine Frontal 21 and Spiegel Online reported on recent footage published by ARIWA from five WIMEX parent animal farms in Baasdorf, Rosefeld, Wettin-Löbejün, Wettin, and Pilsenhöh. The footage showed featherless chickens with festering wounds as well as chickens lying dead on the floor. The footage also showed animals being killed in a manner contrary to animal welfare by having their necks twisted. ARIWA also criticized the fact that fodder was only available for one hour a day and that water was not continuously available either, which led to the sensation of hunger given the animals were bred for rapid weight gain. Michaela Dämmrich, official veterinarian and animal welfare officer of the state of Lower Saxony, classified parts of the recorded conditions as animal welfare violations and described the husbandry system as inappropriate for animals. WIMEX stated that it took the accusations very seriously, but could not provide a detailed assessment.
Subsidies
In 2017, the investigative journalism organisation Correctiv published research on how many subsidies WIMEX receives through its various subsidiaries and then cross-referenced the findings with data on pollutant emissions from the farms. Correctiv criticized that WIMEX receives public subsidies in large amounts, but at the same time harms the common good in the form of factory farming as well as environmental pollution.
In 2018, Der Spiegel reported that WIMEX had received around €275,000 in EU agricultural subsidies the year before and criticized the fact that the payment of the money was not linked to environmental or animal welfare requirements and that WIMEX did not have to pay anything back despite documented misconduct.
Landgrabbing
According to the Johann Heinrich von Thünen Institute, WIMEX is one of the major investors in the agricultural land market in the new states. The Arbeitsgemeinschaft bäuerliche Landwirtschaft criticized the actions of WIMEX and other investors as East German land grabbing. The yearbook critical farming report (Kritischer Agrarbericht) registered WIMEX in a list of agro-industrial large-scale landowners that would destroy many times more farm jobs and endanger agricultural structures.
Food waste
WIMEX has been accused of food waste in vegetable production by local residents. Truckloads of fresh vegetables were dumped and plowed under in the fields instead of being marketed or given to those in need. WIMEX defended the practice by saying that it would be nothing unusual and resulted from high specifications by the purchasing retail chains.
Protests
Animal rights and environmental activists have repeatedly protested against new construction projects pursued by WIMEX. Regarding a planned construction in Cochstedt with a capacity of 80,000 animals, WIMEX announced in June 2016 that it would not pursue the project due to ongoing protest from the public.
References
External links
Poultry companies
Intensive farming
Animal food manufacturers
German companies established in 1985
Companies based in Saxony-Anhalt
Köthen (Anhalt) | WIMEX Group | [
"Chemistry"
] | 2,136 | [
"Eutrophication",
"Intensive farming"
] |
72,920,603 | https://en.wikipedia.org/wiki/FY%20Canis%20Majoris | FY Canis Majoris (FY CMa), also known as HD 58978, is a star about 1,800 light years from the Earth, in the constellation Canis Major (very near the border of Puppis). It is usually a 5th magnitude star, so it will be visible to the naked eye of an observer far from city lights. It is a Gamma Cassiopeiae variable star, whose brightness varies from magnitude 4.8 to 6.25.
In 1967, Alejandro Feinstein detected low amplitude (0.14 magnitude) variability in HD 58978's brightness, from photoelectric observations at La Plata Observatory. The star was given the variable star designation FY Canis Majoris in 1973. During an outburst in 2009, the star brightened to magnitude 4.8, its historical peak brightness. TESS data show that FY CMa pulsates at many different frequencies, with periods ranging from 1.07 hours to 5.8 days.
In 1905, Edward King noted that FY CMa has a peculiar spectrum with an unusually bright Hβ (and other) emission lines. Paul Merrill et al. listed it as a Be star in 1925. Spectra taken by various observers over several decades of the 20th century showed that the strength and relative intensities of the star's emission line are variable, and could change on a timescale of just a few days.
In 2008, Geraldine Peters et al. obtained high resolution spectra from the IUE and found that the Be star has hot, far less massive subdwarf companion star, with which it forms a spectroscopic binary.
Hui-Lau Cao calculated that FY CMa is losing mass at a rate of about 6 × 10−8 /year via a stellar wind with a terminal velocity of about 750 km/sec.
References
Canis Major
036168
058978
Canis Majoris, FY
2855
Gamma Cassiopeiae variable stars
B-type subgiants
O-type subdwarfs | FY Canis Majoris | [
"Astronomy"
] | 419 | [
"Canis Major",
"Constellations"
] |
72,920,826 | https://en.wikipedia.org/wiki/HD%20187086 | HD 187086, also known as HR 7537, is a probable astrometric binary (87% chance) located in the southern constellation Telescopium. It has an average apparent magnitude of 5.9, making it faintly visible to the naked eye. The star is located relatively far at a distance of 1,020 light years based on Gaia DR3 parallax measurements but is rapidly drifting closer with a heliocentric radial velocity of . At its current distance, HD 187086's brightness is diminished by 0.27 magnitudes due to interstellar dust. It has an absolute magnitude of −0.8.
The primary has a stellar classification of M1 III, indicating that it is a red giant. It is currently on the asymptotic giant branch, fusing hydrogen and helium shells around an inert carbon core. It has 1.76 times the mass of the Sun but it has expanded to 111 times the solar radius. It radiates 1,031 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of , giving it a red hue. HD 187086 is particularly metal enriched ([Fe/H] = +0.24).
HD 187086 fluctuates between 5.95 and 6.07 and its variability was first noticed by P.M. Corben in 1971 after being listed as an ordinary M-type giant a year prior. In 2002, Chris Koen and Laurent Eyer reported that the Hipparcos data shows periodic fluctuations with an amplitude of 0.023 magnitudes, and a period of 7.6805 days. As of 2004 however, it is not confirmed to be variable.
References
M-type giants
Suspected variables
Astrometric binaries
Telescopium
187086
095798
CD-47 13103
7537
Asymptotic-giant-branch stars
Telescopii, 69 | HD 187086 | [
"Astronomy"
] | 395 | [
"Telescopium",
"Constellations"
] |
72,920,864 | https://en.wikipedia.org/wiki/Yasmine%20Amhis | Yasmine Amhis (born 1982, Algiers) is a French-Algerian particle physicist. In 2016, she was awarded the Jacques Herbrand Prize. She is the granddaughter of the Algerian poet and writer Djoher Amhis-Ouksel.
Early life and education
In 1999, after high school in Algeria, Yasmine Amhis pursued undergraduate studies in France. She obtained her master's degree at the University of Paris-Sud in Orsay, then earned a thesis grant in 2006 and started her work at IJCLab Orsay under the supervision of Marie -Hélène Schune and Jacques Lefrançois. Work on her thesis introduced her to the LHCb experiment at CERN. After she obtained her PhD, she moved to Switzerland for a three-year postdoctoral position at the École Polytechnique Fédérale de Lausanne.
Career
In 2012, she obtained a permanent research scientist position at CNRS. Her outstanding academic career was published by Campus France, France Alumni, in 2017.
Amhis has devoted her research to topics related to the "bottom-quark" baryon, topics she reviewed in 2017 and 2022. In 2016, she was awarded the Jacques-Herbrand prize by the French Academy of Sciences Given her expertise and her commitment to the LHCb experiment, a collaboration of more than 1,000 scientists, she was elected in April 2022 to the strategic position of "physics coordinator".
Engagements
Given her background and origins, Amhis, involved naturally with other physicists from the African diaspora to the development of science for developing countries. She engaged in the initiative of the "African Strategy for Fundamental and Applied Physics" (ASFAP) founded in 2020 by among others, Fairouz Malek and Ketevi Assamagan. Up to 2022, she coordinated the group responsible for the strategy in particle and astroparticle physics.
Publications
Amhis is the author or co-author of more than 600 articles, most of them related to the LHCb experiment. Among all of these articles, 14 have been cited more than 500 times
Awards
In 2016, Amhis received the Jacques-Herbrand prize from the French Academy of Sciences.
References
External links
Yasmine Amhis's website
Living people
1982 births
People from Algiers
21st-century French physicists
21st-century Algerian physicists
French women physicists
Algerian women physicists
21st-century Algerian women scientists
French people of Algerian descent
Particle physicists
Paris-Sud University alumni
Academic staff of the École Polytechnique Fédérale de Lausanne
People associated with CERN | Yasmine Amhis | [
"Physics"
] | 521 | [
"Particle physicists",
"Particle physics"
] |
72,921,669 | https://en.wikipedia.org/wiki/Fipravirimat | Fipravirimat is an experimental drug for the treatment of HIV/AIDS. It belongs to a class of drugs known as maturation inhibitors.
Fipravirimat was being developed by ViiV Healthcare, but development was stopped in 2023.
See also
BMS-955176
References
Antiviral drugs
Carboxylic acids
Organofluorides
Pentacyclic compounds
Sulfones | Fipravirimat | [
"Chemistry",
"Biology"
] | 86 | [
"Antiviral drugs",
"Carboxylic acids",
"Functional groups",
"Sulfones",
"Biocides"
] |
72,922,155 | https://en.wikipedia.org/wiki/Sreenath%20Subrahmanyam | Sreenath Subrahmanyam is a biologist and the director for the Institute of Bioecosciences, Virginia, United States of America.
Education
Sreenath received his bachelor's degree in biological sciences from Loyola College, Madras, and a PhD diploma in biological sciences from Cranfield University, UK. Sreenath is a Beahrs Fellow on the Natural Resources Management Program, University of California, Berkeley.
Research
Sreenath works on climate change adaptation strategies in Western Ghats, Indiacomputationally modelling tracheophytes and forest ecosystems. Sreenath worked on Environmental impacts of the proposed lignite mine at Jayankondam. At Cranfield University, Sreenath developed a new approach for the computational design of molecular imprinting, which is followed by research groups around the world. Sreenath proposed that natural receptors can be used in bio-recognition, an idea which many researchers have successfully used in Biology. Sreenath is a Fellow of the Royal Society of Biology,
Training programs on ecology and conservation biology
Sreenath continues to direct a number of training programs such as the Young Advantage Program, Environmental Leadership Program, and the Faculty Enrichment Program.
Popular contributions
Environmental impacts of thermal power plant: case study
Salivary proteins of plant-feeding hemipteroids–implication in phytophagy
Application of natural receptors in sensors and assays
Analytical methods for determination of mycotoxins: a review
Ecological modelling of a wetland for phytoremediating Cu, Zn and Mn in a gold–copper mine site using Typha domingensis (Poales: Typhaceae) near Orange, NSW, Australia
Effective climate change adaptation strategies for biodiversity conservation
References
External links
Living people
Year of birth missing (living people)
Indian ecologists
UC Berkeley College of Natural Resources alumni
Scientists from Chennai
University of Madras alumni
Loyola College, Chennai alumni
alumni of Cranfield University
Indian expatriate academics in the United States
Fellows of the Royal Society of Biology
Fellows of the Royal Society of Chemistry
Environmental scientists | Sreenath Subrahmanyam | [
"Environmental_science"
] | 416 | [
"Indian environmental scientists",
"Environmental scientists"
] |
74,382,102 | https://en.wikipedia.org/wiki/Love%20Lake%2C%20Dubai | Love Lake is an artificial lake shaped like a heart. It is part of the Qudra Lakes in Saih Al Salam, Dubai, United Arab Emirates. There are mesquite trees all around the lake. This is a popular spot in the Al Marmoum area of Bab Al Shams Desert.
Overview
Love Lake, also referred to as the "Heart Lake", resembles an oasis nestled in the midst of the desert. Its central feature consists of two massive interconnected heart-shaped lakes. On the western shore of the lakes, trees have been planted to spell out the word "Love", while the winding pathways on the eastern shore create an image of lovers embracing. Visitors can see various local birds and fish, including Japanese orange and gold fish, which swim in the clear lakes.
The Love Lake opened to the public in November 2018 and gained widespread recognition through an Instagram post by Hamdan bin Mohammed Al Maktoum, the Crown Prince of Dubai.
This man-made oasis is situated within the Al Marmoom Desert Conservation Reserve and is a part of the artificial desert wetland, Al Qudra Lake. Located at a considerable distance from the city, with a linear distance of approximately 30 kilometers from the outskirts of the Dubai city, it is most conveniently accessed by self-driving. This lake is big enough to see from space, or on Google Maps or Google Earth.
References
Artificial lakes of the United Arab Emirates
Heart symbols
Geography of Dubai (emirate) | Love Lake, Dubai | [
"Mathematics"
] | 301 | [
"Heart symbols",
"Symbols"
] |
74,384,175 | https://en.wikipedia.org/wiki/Mari%C3%ABlle%20Stoelinga | Mariëlle I. A. Stoelinga is a Dutch computer scientist based in the Netherlands. She is full professor of Risk Management for High Tech Systems in the Formal Methods & Tools Group at the University of Twente, Enschede, the Netherlands and holds a partial appointment as a full professor in the Software Science department at the Radboud University, Nijmegen. She is also director of Life Long Learning at the Faculty of Electrical Engineering, Mathematics and Computer Science, at the University of Twente.
Education
Stoelinga obtained her degree in Mathematics & Computer Science at the University of Nijmegen, with a specialization in foundations of mathematics and computer science. Her Master’s thesis covered the topic of Exact Representations of and Computability on Real Numbers, under the supervision of Erik Barendsen and Henk Barendregt.
In 2001 she obtained her PhD at the Computing Science Institute in Nijmegen, the Netherlands, supervised by Frits Vaandrager, with a thesis titled: Alea Jacta est: Verification of Probabilistic, Real–Time and Parametric Systems.
Research
Stoelinga main area of research deals with quantitative risk assessment methods to ensure that the risks associated with high technology systems are within acceptable limits. She develops techniques for analyzing, predicting and improving the reliability of complex systems using fault trees, model-based testing and architectural reliability modelling.
A distinguishing feature of techniques developed by Stoelinga is compositionality, as she derives the risk profile of a complex system from the risk profiles of its components, using techniques from model checking.
This approach is applied in the field of predictive maintenance and on the interactions between safety and (cyber)security, as testified by her recently granted projects: PrimaVera, CAESAR and ZORRO.
Career
From December 2001 to April 2004, Stoelinga worked as a Post-doc researcher in Computer Engineering at the University of California, Santa Cruz, USA, with Prof. Luca de Alfaro.
From August 2005 to September 2005 she was a visiting researcher at the University of California, Santa Cruz, and starting May 2004 she was an assistant professor in the Formal Methods & Tools Group, at the University of Twente, where she now holds a full professor position alongside a partial appointment as a full professor at the Radboud University, Nijmegen, in the Software Science department.
In 2019, she received a substantial grant from the Dutch Research Council (NWO). She also received an ERC Consolidator Grant from the European Research Council. With the NWO grant, she is leading a team of industrialists and academics to better integrate the various steps in predictive maintenance. With the ERC grant, Stoelinga is developing new methods for better and more integrated assessment of safety and (cyber)security. Furthermore, Stoelinga recently received another grant from the Dutch Research Council (NWO) for the ZORRO Project: Engineering for Zero Downtime in Cyber-Physical Systems via Intelligent Diagnostics.
References
Computer scientists
Year of birth missing (living people)
Living people | Mariëlle Stoelinga | [
"Technology"
] | 629 | [
"Computer science",
"Computer scientists"
] |
74,384,507 | https://en.wikipedia.org/wiki/Lanmaoa%20asiatica | Lanmaoa asiatica is a species of bolete mushroom in the family Boletaceae that is native to southwest China and adjacent regions. It is reddish in color and it is an ectomycorrhizal symbiote of the Yunnan Pine, Pinus yunnanensis.
It is considered a choice wild edible in Yunnan Province and may have hallucinogenic compounds which may or may not be removable by cooking. It is unclear what compounds exist in the fungi that could cause such hallucinations, but if they exist, they are likely to be different from those in psilocybin mushrooms.
US Treasury Secretary Janet Yellen ate a dish with L. asiatica when visiting China in July 2023.
References
Boletaceae
Fungi described in 2015
Fungi of China
Fungus species | Lanmaoa asiatica | [
"Biology"
] | 161 | [
"Fungi",
"Fungus species"
] |
74,385,749 | https://en.wikipedia.org/wiki/Accumulated%20winter%20season%20severity%20index | The accumulated winter season severity index or AWSSI provides a scientific way to compare the severity of a winter relative to its weather history. Points are assigned daily based on the maximum and minimum temperature, snowfall and snow depth for a specific site and accumulated through the winter. The index can be used for historical comparisons, road maintenance and to understand how severe a current winter is.
History
The AWSSI was originally developed in 2015 by researchers Barbara E. Mayes Boustead, Steven D. Hilberg, Martha D. Shulski and Kenneth G. Hubbard. The index was developed "to examine relationships to teleconnection patterns, determine trends, and create sector-specific applications, as well as to analyze an ongoing winter or any individual winter season to place its severity in context."
Calculation
Values are assigned on a daily basis based on the maximum and minimum temperature, 24-hour snowfall and depth of snow on the ground. Values start being calculated at the start of winter. The start of winter is defined when any of these conditions are met: 1) daily maximum temperature ≤ 32 °F (0 °C), 2) first measurable snowfall or 3) it is December 1. Likewise, values stop being calculated at the end of winter – when the last of the following four conditions occurs: 1) daily maximum temperature ≤ 32 °F (0 °C) no longer occurs, 2) no daily measurable snowfall, 3) daily snow depth ≥ 1.0 in. (2.5 cm) is no longer observed, or 4) it is March 1.
AWSSI climatology
See also
Regional Snowfall Index
References
External links
Accumulated Winter Season Severity Index (AWSSI)
Hazard scales
Meteorological quantities
National Centers for Environmental Prediction | Accumulated winter season severity index | [
"Physics",
"Mathematics"
] | 345 | [
"Quantity",
"Physical quantities",
"Meteorological quantities"
] |
74,386,326 | https://en.wikipedia.org/wiki/Francisco%20Balzarotti | Francisco Balzarotti (born in 1983 in Buenos Aires, Argentina) is an Argentinian scientist known for his work in super-resolution microscopy, particularly MINFLUX. He is a Group Leader at the Research Institute of Molecular Pathology (IMP) in Vienna, Austria.
Education
From 2002 to 2007, Balzarotti studied electrical engineering at the University of Buenos Aires in Buenos Aires, Argentina. In 2012, he earned his Ph.D. in Electrical Engineering, working on research topics such as nanophotonics, optical nanolithography, superlenses, and plasmonics.
Career and research
For his postgraduate work, Balzarotti relocated to Germany to work as a postdoctoral researcher in the Department of NanoBiophotonics at the Max Planck Institute for Biophysical Chemistry, led by Nobel Laureate Stefan W. Hell.
In Göttingen, Balzarotti played a central role in developing the super-resolution microscopy method MINFLUX which was named Breakthrough of the Year in 2017 by Physics World. The method was even described as the Holy Grail in Light Microscopy.
MINFLUX combines elements of information theory with the single-emitter nature of PALM/STORM and the beam geometries typically used in STED. During Balzarotti's time in Göttingen, they were able to show that with MINFLUX, a given localization precision can be obtained by using much fewer photons than in conventional centroid-localization techniques such as PALM/STORM. Hence, MINFLUX attains nanometer-scale resolution more quickly and with fewer emitted photons than previously possible. Subsequent work increased the application space of the technology even further.
Since 2020, Balzarotti has been a Group Leader at the Research Institute of Molecular Pathology (IMP) in Vienna, Austria, supported by the European Research Council. At the IMP, he set up the Advanced Microscopy and Biophysics group.
Balzarotti's group focuses on the development of novel optical methods and instrumentation for the observation of biological phenomena with the highest fidelity. His interdisciplinary group combines expertise in physics, engineering, mathematics, and biology.
Balzarotti is a well-known microscopist and an established member of the advanced microscopy community. Hence, he is frequently invited as a keynote speaker at key conferences in the field.
Balzarotti's group in collaboration with Mark Bates, organized the Single Molecule Localization Symposium 2023, which was hosted at IMP in Vienna.
Awards and honours
2019–2024 European Research Council (ERC) Starting Grant "NANO4LIFE"
2024 Frontiers of Science Award
References
External links
Janelia & EMBL BioImaging Seminar Series
IMP Mini Lectures
IMP Profile
Living people
Microscopists
Optical physicists
European Research Council grantees
1983 births
University of Buenos Aires alumni | Francisco Balzarotti | [
"Chemistry"
] | 559 | [
"Microscopists",
"Microscopy"
] |
74,386,455 | https://en.wikipedia.org/wiki/Inozemtsev%20model | In quantum statistical physics, the Inozemtsev model is a spin chain, defined on a one-dimensional, periodic lattice. Unlike the prototypical Heisenberg spin chain, which only includes interactions between neighboring sites of the lattice, the Inozemtsev model has long-range interactions, that is, interactions between any pair of sites, regardless of the distance between them.
It was introduced in 1990 by Vladimir Inozemtsev as a model which interpolates between the Heisenberg XXX model and the Haldane–Shastry model. Like those spin chains, the Inozemtsev model is exactly solvable.
Formulation
For a chain with spin 1/2 sites, the quantum phase space is described by the tensor product Hilbert space . The (elliptic) Inozemtsev model is given by the (unnormalised) Hamiltonian
where the pair potential is the Weierstrass elliptic function, and denotes the Pauli vector at the th site (acting nontrivially on the th copy of in ).
The periods of the Weierstrass elliptic function are the length of the chain, to ensure periodic boundary conditions, together with an imaginary period that sets the interaction range and is traditionally parameterized as where . The truly long-range Haldane-Shastry chain is obtained when the imaginary period is removed (, so ) while, upon renormalisation, the Heisenberg spin chain is recovered in the limit (). The infinite-length limit instead gives hyperbolic potential , which is why the resulting spin chain is sometimes called the hyperbolic (as opposed to elliptic) Inozemtsev chain.
Exact solution
The system has been exactly solved by means of an 'extended' Bethe ansatz method. The model was solved by Inozemtsev first in the infinite lattice size limit, and later for finite size.
AdS/CFT correspondence
The model can be used to understand certain aspects of the AdS/CFT correspondence proposed by Maldacena. Specifically, integrability techniques have turned out to be useful for an 'integrable' instance of the correspondence. On the string theory side of the correspondence, one has a type IIB superstring on , the product of five-dimensional Anti-de Sitter space with the five-dimensional sphere. On the conformal field theory (CFT) side one has N = 4 supersymmetric Yang–Mills theory (N = 4 SYM) on four-dimensional space.
Spin chains have turned out to be useful for computing specific anomalous dimensions on the CFT side, which can then provide evidence for the correspondence if matching observables are computed on the string theory side. In the so-called 'planar limit' or 'large ' limit of N = 4 SYM, in which the number of colors , which parametrizes the gauge group , is sent to infinity, determining one-loop anomalous dimensions becomes equivalent to the problem of diagonalizing an appropriate spin chain. The Inozemtsev model is one such model which has been useful in determining these quantities. While the match only holds up to three loops in perturbation theory, and its appearance might thus have been somewhat of a coincidence, this development has brought the Inozemtsev chain under the attention of a wider audience of researchers.
See also
Quantum Heisenberg model
Haldane–Shastry model
References
Quantum lattice models | Inozemtsev model | [
"Physics"
] | 712 | [
"Quantum mechanics",
"Quantum lattice models"
] |
74,387,063 | https://en.wikipedia.org/wiki/Catalog%20of%20MCA%20Control%20Patterns | Jannie Hofmeyr published the first catalog of control patterns in metabolic control analysis (MCA). His doctoral research. concerned the use of graphical patterns to elucidate chains of interaction in metabolic regulation, later published in the European Journal of Biochemistry. In his thesis, he cataloged 25 patterns for various biochemical networks. In later work, his research group, together with Carl D Christensen and Johann Rohwer, developed a Python based tool called SymCA that was part of the PySCeSToolbox toolkit that could generate patterns automatically and symbolically from a description of the network. This software was used to generate the patterns shown below.
The control equations, especially the numerators of the equations, can give information on the relative importance and routes by which perturbations travel through a biochemical network
Notation
Control patterns describe how a perturbation to a given parameter affects the steady-state level of a given variable. For example, a concentration control coefficient can describe how the overexpression of a specific enzyme can influence steady-state metabolite concentrations. Flux control coefficients are similar in that they describe how a perturbation in a given enzyme affects steady-state flux through a pathway. Such coefficients can be written in terms of elasticity coefficients.
Elasticity coefficients are local properties that describe how a single reaction is influenced by changes in the substrates and products that might influence the rate. For example, given a reaction such as:
we will assume it has a rate of reaction of . This reaction rate can be influenced by changes in the concentrations of substrate or product . This influence is measured by an elasticity which is defined as:
To make the notation manageable, a specific numbering scheme is used in the following patterns. If a substrate has an index of , then the reaction index will be . The product elasticity will also have an index of . This means that a product elasticity will have identical subscripts and superscripts making them easy to identify. The source boundary species is always labeled zero as well as the label for the first reaction.
For example, the following fragment of a network illustrates this labeling:
then
Linear Chains
Two-Step Pathway
Assuming both steps are Irreversible
Assuming both steps are Reversible
Three-Step Pathway
Assuming the three steps are Irreversible
Denominator:
Assume that each of the following expressions is divided by d
Assuming the three steps are Reversible
Denominator:
Assume that each of the following expressions is divided by
Four-Step Pathway
Denominator:
Assume that each of the following expressions is divided by .
Linear Chains with Negative Feedback
Three-Step Pathway
Denominator:
Assume that each of the following expressions is divided by .
Four-Step Pathway
Denominator:
Assume that each of the following expressions is divided by .
Branched Pathways
At steady-state , therefore define the following two terms:
Denominator:
Assume that each of the following expressions is divided by .
See also
Metabolic control analysis
Branched pathways
Elasticity coefficient
Biochemical systems theory
Control coefficient (biochemistry)
Flux (metabolism)
References
Metabolism
Mathematical and theoretical biology
Systems biology | Catalog of MCA Control Patterns | [
"Chemistry",
"Mathematics",
"Biology"
] | 630 | [
"Mathematical and theoretical biology",
"Applied mathematics",
"Cellular processes",
"Biochemistry",
"Metabolism",
"Systems biology"
] |
74,388,835 | https://en.wikipedia.org/wiki/My%20Body%20No%20Choice | My Body No Choice is a 2022 American stage drama made up of eight collected monologues. The show was created and directed by Molly Smith, the Artistic Director of Arena Stage in Washington, DC. Each of the monologues that make up the play were commissioned from eight different female playwrights. The play was created in opposition of the 2022 U.S. Supreme Court ruling regarding Dobbs v. Jackson Women's Health Organization, which effectively overturned the constitutional right to abortion that had been established by Roe v. Wade in 1973. During the same time that it was being shown at Arena Stage, twenty other venues across the United States put on a production of the play.
Background
In June 2022, the U.S. Supreme Court issued its judgement in Dobbs v. Jackson Women's Health Organization, . The Supreme Court overruled Roe v. Wade (1973) on the grounds that the substantive right to abortion was not "deeply rooted in this Nation's history or tradition", nor considered a right when the Due Process Clause was ratified in 1868. The court said this "right" was unknown in U.S. law until Roe v. Wade. The court held that the constitution did not include an individual's right to abortion. This decision also overruled Planned Parenthood v. Casey (1992), and upended more than two decades of federal policy and medical practice. The ruling returned to individual states the power to regulate any aspect of abortion not protected by federal law.
Molly Smith, Artistic Director of Arena Stage, commissioned eight playwrights to write monologues in response to this action. The works were to be produced together under the title No Body No Choice.
The stage show was premiered in an October to early November run in 2022 at the Arlene and Robert Kogod Cradle in Washington, D.C., part of the Arena Stage complex. More than twenty readings and productions were also held in various universities and theaters across the country, in an artists' response to the ruling.
Monologues
The short pieces consist of both fiction and non-fiction monologues that address issues of women's sexuality, autonomy, and freedom of choice. Several address decisions related to their bodies and having abortions.
Authors include established and rising writers: Lee Cataluna, Fatima Dyfan, Dale Orlandersmith, Sarah Ruhl, Mary Hall Surface, V (formerly writing as Eve Ensler, and Lisa Loomer. One woman chose to remain Anonymous.
Cast:
Joy Jones — a woman contemplates having learned that her mother attempted to get an abortion after learning she was pregnant. Despite being unwanted, the woman became a success as an adult.
- a student at a Catholic high school talks about the response to her having spoken there in favor of abortion.
- a middle-aged woman recounts a miscarriage and related required surgery to avoid infection, with fear that such medical emergencies could be criminalized under punitive abortion laws.
Dani Stoller — in "Battered Baby", a woman who suffered childhood and adult abuse feels newfound freedom after having been able to choose to have an abortion. The date is 4 July US Independence Day.
Toni Rae Salmi, an older woman muses over her mother's unexpected decision to stop chemotherapy that was recommended by her doctor. She had always gone along with authority figures before but has decided for herself on this issue.
Tori Gomez — a woman in the post-Dobbs world who lives in a state with severe restrictions and struggles to overcome obstacles and get an abortion.
Deirdre Staples — a free thinking woman recounts her coming of age, sexual awakening, and successful efforts to avoid pregnancy.
In the monologue by Sarah Ruhl, a student shares experience about speaking in favor of abortion at a Catholic school. The monologue by Mary Hall Surface shares a disturbing account of a miscarriage to avoid risk of infection or hemorrhage, and expresses concern whether such medical emergencies would be criminalized in post-the June 2022 US supreme court judgement.
The remaining monologues more broadly explore topics of bodily autonomy and freedom of choice. In Fatima Dyfan's piece, “A Rest Stop,” a free thinking, venturesome (Deidre Staples) presents her sexual awakening and successful effort to avoid getting pregnant. In Lee Cataluna's “Things My Mother Told Me”, an older woman (Toni Rae Salmi) dwells on her mother's unexpected decision to stop her doctor-recommended chemotherapy.
Lisa Loomer's “Roxy” is played as the last monologue in the sequence.
Reception
"According to Peter Marks, "let women decide for their own bodies" is the simple message this show intends to give; it is not ground breaking but ground claiming. Director Molly Smith said she received some complaints from anti-abortion patrons, but also received substantial support from supporters of abortion choice.
See also
Abortion debate
Abortion-rights movements
My body, my choice
Our Bodies, Ourselves
Planned Parenthood
Sexual and reproductive health and rights
Theater in the United States
References
Autonomy
Human body
Violence against women
Women's rights
2022 plays
Feminist literature | My Body No Choice | [
"Physics"
] | 1,045 | [
"Human body",
"Physical objects",
"Matter"
] |
74,389,181 | https://en.wikipedia.org/wiki/Haldane%E2%80%93Shastry%20model | In quantum statistical physics, the Haldane–Shastry model is a spin chain, defined on a one-dimensional, periodic lattice. Unlike the prototypical Heisenberg spin chain, which only includes interactions between neighboring sites of the lattice, the Haldane–Shastry model has long-range interactions, that is, interactions between any pair of sites, regardless of the distance between them.
The model is named after and was defined independently by Duncan Haldane and B. Sriram Shastry. It is an exactly solvable model, and was exactly solved by Shastry.
Formulation
For a chain with spin 1/2 sites, the quantum phase space is described by the Hilbert space . The Haldane–Shastry model is described by the Hamiltonian
where denotes the Pauli vector at the th site (acting nontrivially on the th copy of in ). Note that the pair potential suppressing the interaction strength at longer distances is an inverse square , with the chord distance between the and th sites viewed as being equispaced on the unit circle.
See also
Inozemtsev model
References
Quantum lattice models
Spin models | Haldane–Shastry model | [
"Physics"
] | 238 | [
"Spin models",
"Statistical mechanics",
"Quantum mechanics",
"Quantum lattice models"
] |
74,391,075 | https://en.wikipedia.org/wiki/Charenton%20Metro-Viaduct | The Charenton Metro-Viaduct is a railroad girder bridge located in the French department of Val-de-Marne in the Île-de-France region. It links the communes of Charenton-le-Pont and Maisons-Alfort, crossing the Marne river, as well as the A4 autoroute and 103 departmental road. First put into operation in 1970, the viaduct is used by trains on line 8 of the Paris metro.
The total length of the viaduct is 199 m. Made up of steel beams resting on concrete piers, the viaduct has a continuous gradient, due to the difference in level between the two banks of the Marne. It was renovated for the first time in 2011.
Location
The viaduct is located between the Charenton-Écoles and Maisons-Alfort–Stade stations. It crosses the 103 departmental road, the A4 autoroute and then the Marne. Since Charenton-le-Pont is located on a hillside overlooking the Marne, the viaduct is inclined to compensate for the difference in level between the two stations. The structure is flanked by two tramways, enabling line 8 to return underground.
The surrounding bridges are the Charenton bridge, to the east, and the railway viaduct of the Paris–Marseille railway, to the west. The structure is only a few hundred meters away from the confluence of the Marne and Seine rivers.
Technical specifications
The total length of the viaduct is 199 m, with an average height of 15.05 m between the rail and the water level. The structure has a continuous gradient of 41 mm/m towards Maisons-Alfort. It comprises two 55.5 m central sections and two 30 m lateral sections. The structure rests on six supports for three concrete piles, one of which is set in the riverbed.
The steel deck is designed to aesthetically blend into the landscape. It consists of a continuous beam supported by two vertical solid-core girders located between the two tracks. By enclosing the lower part of the trains, they minimize rolling noise. The track rests on ballast, which is laid on a concrete screed.
History
With the Charenton bridge becoming too saturated, in 1965 it was decided to extend line 8 from Charenton-Écoles to Maisons-Alfort and Créteil. To achieve this, the line had to cross the Marne, but the difference in level between the two banks was too great to allow the line to pass under the river, as Charenton was located on a highland plateau. Instead, an elevated viaduct crossing was chosen – a first for a Paris metro since 1909.
This extension, which had been planned as early as the 1930s, had been postponed due to World War II. In anticipation of the metro's construction, buildings in Charenton's Rue de Paris were expropriated in 1937, including the Hôtel du Plessis-Bellière. The upper part of Square Jules Noël and Place de Valois, as well as the buildings lining it, were built to replace the destroyed buildings.
Construction of the viaduct began in the spring of 1968, with the construction of the piers. The steel girders were installed in June 1969, and the viaduct was completed in November, enabling load tests to be carried out using five-motor Sprague-Thomson trains. The line was opened to traffic on 19 September 1970, with the extension of line 8 from Charenton-Écoles to Maisons-Alfort-Stade.
In the context of the extension of line 8 to Pointe du Lac, the viaduct was closed for renovations during the summers of 2010 and 2011, with a replacement shuttle service in place during this period. The aim of the renovation is to improve the soundproofing of the structure and adapt it to the increased traffic associated with the extension. After the removal of the tracks and ballast, the concrete slab was replaced and then covered with an anti-vibration rubber coating, reducing noise levels by 10 dB per train. At the same time, the viaduct was repainted in a blue-green color, replacing the original blue-gray. The total cost of the project was four million euros.
References
See also
Bibliography
Jean Robert, Notre Métro, Paris, éd. Jean Robert, 1983, 2e éd., 511 p.
Clive Lamming, La grande histoire du métro parisien de 1900 à nos jours, Atlas, October 2015, 336 p.
Related articles
Paris Métro Line 8
Pont ferroviaire
Crueize Viaduct
Rue de Paris (Charenton-le-Pont)
External links
Architectural resource: Structurae
Trains
Paris Métro
Viaducts in France
Île-de-France
Engineering | Charenton Metro-Viaduct | [
"Technology",
"Engineering"
] | 951 | [
"Construction",
"Trains",
"Civil engineering",
"Transport systems"
] |
74,393,286 | https://en.wikipedia.org/wiki/Debora%20%C5%A0ija%C4%8Dki | Debora Šijački is a computational cosmologist whose research involves computational methods for simulating the formation and development of the structures in the universe including galaxies, galaxy clusters, and dark matter, including collaborations in the Illustris project. Originally from Serbia, she was educated in Italy and Germany, and works in the UK as a professor at the University of Cambridge and deputy director of the Kavli Institute for Cosmology.
Education and career
Šijački is originally from Belgrade, the daughter of Serbian physicist Đorđe Šijački|sr|Ђорђе Шијачки and mother Jelena Vasiljevic Serbian psychologist, grew up in Belgrade, capital of ex Yugoslavia, today Serbia. She was an undergraduate at the University of Padua in Italy, and completed a Ph.D. through Ludwig Maximilian University of Munich in Germany in 2007 for research performed at the Max Planck Institute for Astrophysics. Her dissertation, Non Gravitational Heating Mechanisms in Galaxy Clusters, was jointly supervised by Volker Springel and Simon White.
She came to the University of Cambridge in 2007–2010, as a postdoctoral researcher in the Institute of Astronomy. After continued postdoctoral research from 2010 to 2012 in the US at the Harvard–Smithsonian Center for Astrophysics, she returned to the Cambridge Institute of Astronomy in 2013 as a university lecturer. She became Reader in Astrophysics and Cosmology in 2016, and Professor of Astrophysics and Cosmology in 2021.
Recognition
Šijački received the Otto Hahn Medal for her doctoral research. She was the 2019 recipient of the Ada Lovelace Award for High Performance Computing of the Partnership for Advanced Computing in Europe (PRACE), recognizing her "numerous high-impact results in astrophysics based on numerical simulations on state-of-the-art supercomputers".
References
Year of birth missing (living people)
Living people
Cosmologists
Astrophysicists
Women astrophysicists
Computational physicists
Scientists from Belgrade
Serbian women scientists
University of Padua alumni
Ludwig Maximilian University of Munich alumni
Professors of Astrophysics (Cambridge) | Debora Šijački | [
"Physics"
] | 418 | [
"Astrophysicists",
"Computational physicists",
"Astrophysics",
"Computational physics"
] |
74,393,350 | https://en.wikipedia.org/wiki/Kriegeriaceae | The Kriegeriaceae are a family of fungi in the subdivision Pucciniomycotina. The family currently comprises four genera, one of which (Kriegeria) contains a plant pathogenic species with auricularioid (laterally septate) basidia. The other genera contain species currently known only from their yeast states.
References
Basidiomycota families
Pucciniomycotina
Yeasts
Taxa described in 2013 | Kriegeriaceae | [
"Biology"
] | 91 | [
"Yeasts",
"Fungi"
] |
74,393,422 | https://en.wikipedia.org/wiki/Camptobasidiaceae | The Camptobasidiaceae are a family of fungi in the subdivision Pucciniomycotina. The family currently comprises two genera, one of which (Camptobasidium) contains an aquatic, hyphal species with auricularioid (laterally septate) basidia. The other genus contains species currently known only from their yeast states.
References
Basidiomycota families
Pucciniomycotina
Yeasts
Taxa described in 1996
Taxa named by Royall T. Moore | Camptobasidiaceae | [
"Biology"
] | 102 | [
"Yeasts",
"Fungi"
] |
74,393,511 | https://en.wikipedia.org/wiki/GPM%20J1839%E2%88%9210 | GPM J1839−10 is a potentially unique ultra-long period magnetar located about 15,000 light-years away from Earth in the Scutum constellation, in the Milky Way. It was discovered by a team of scientists at Curtin University using the Murchison Widefield Array. Its unusual characteristics violate current theory and prompted a search of other radio telescope archives, including the Giant Metrewave Radio Telescope and the Very Large Array, which revealed evidence of the object dating back to 1988. The signature of the object went unnoticed because scientists did not know to look for its unusual behavior.
The current understanding of neutron stars is that below a certain rate of rotation, called "the death line", they cease emissions. Uniquely, not only does GPM J1839−10 have an extremely slow rotation of approximately twenty-two minutes, it emits bursts of radio waves lasting up to five minutes, for which there is currently no generally accepted explanation.
See also
GLEAM-X J162759.5−523504.3
GCRT J1745−3009
PSR J0901–4046
Further reading
Not open access.
References
Star types
Stellar phenomena
Unsolved problems in astronomy | GPM J1839−10 | [
"Physics",
"Astronomy"
] | 249 | [
"Physical phenomena",
"Unsolved problems in astronomy",
"Concepts in astronomy",
"Magnetars",
"Astronomical controversies",
"Astronomical classification systems",
"Magnetism in astronomy",
"Stellar phenomena",
"Star types"
] |
74,395,167 | https://en.wikipedia.org/wiki/Soddy%20circles%20of%20a%20triangle | In geometry, the Soddy circles of a triangle are two circles associated with any triangle in the plane. Their centers are the Soddy centers of the triangle. They are all named for Frederick Soddy, who rediscovered Descartes' theorem on the radii of mutually tangent quadruples of circles.
Any triangle has three externally tangent circles centered at its vertices. Two more circles, its Soddy circles, are tangent to the three circles centered at the vertices; their centers are called Soddy centers. The line through the Soddy centers is the Soddy line of the triangle. These circles are related to many other notable features of the triangle. They can be generalized to additional triples of tangent circles centered at the vertices in which one circle surrounds the other two.
Construction
Let be the three vertices of a triangle, and let be the lengths of the opposite sides, and be the semiperimeter. Then the three circles centered at have radii , respectively.
By Descartes' theorem, two more circles, sometimes also called Soddy circles, are tangent to these three circles. The centers of these two tangent circles are the Soddy
centers of the triangle.
Related features
Each of the three circles centered at the vertices crosses two sides of the triangle at right angles, at one of the three intouch points of the triangle, where its incircle is tangent to the side. The two circles tangent to these three circles are separated by the incircle, one interior to it and one exterior. The Soddy centers lie at the common intersections of three hyperbolas, each having two triangle vertices as foci and passing through the third vertex.
The inner Soddy center is an equal detour point: the polyline connecting any two triangle vertices through the inner Soddy point is longer than the line segment connecting those vertices directly, by an amount that does not depend on which two vertices are chosen. By Descartes' theorem, the inner Soddy circle's curvature is , where is the triangle's area, is its circumradius, and is its inradius. The outer Soddy circle has curvature . When this curvature is positive, the outer Soddy center is another equal detour point; otherwise the equal detour point is unique. When the outer Soddy circle has negative curvature, its center is the isoperimetric point of the triangle: the three triangles formed by this center and two vertices of the starting triangle all have the same perimeter. Triangles whose outer Soddy circle degenerates to a straight line with curvature zero have been called "Soddyian triangles". This happens when and causes the curvature of the inner Soddy circle to be .
Excentric circles
As well as the three externally tangent circles formed from a triangle, three more triples of tangent circles also have their centers at the triangle vertices, but with one of the circles surrounding the other two. Their triples of radii are or where a negative radius indicates that the circle is tangent to the other two in its interior. Their points of tangency lie on the lines through the sides of the triangle, with each triple of circles having tangencies at the points where one of the three excircles is tangent to these lines. The pairs of tangent circles to these three triples of circles behave in analogous ways to the pair of inner and outer circles, and are also sometimes called Soddy circles. Instead of lying on the intersection of the three hyperbolas, the centers of these circles lie where the opposite branch of one hyperbola with foci at the two vertices and passing through the third intersects the two ellipses with foci at other pairs of vertices and passing through the third.
Soddy lines
The line through both Soddy centers, called the Soddy line, also passes through the incenter of the triangle, which is the homothetic center of the two Soddy circles, and through the Gergonne point, the intersection of the three lines connecting the intouch points of the triangle to the opposite vertices. Four mutually tangent circles define six points of tangency, which can be grouped in three pairs of tangent points, each pair coming from two disjoint pairs of circles. The three lines through these three pairs of tangent points are concurrent, and the points of concurrency defined in this way from the inner and outer circles define two more triangle centers called the Eppstein points that also lie on the Soddy line.
The three additional pairs of excentric Soddy circles each are associated with a Soddy line through their centers. Each passes through the corresponding excenter of the triangle, which is the center of similitude for the two circles. Each Soddy line also passes through an analog of the Gergonne point and the Eppstein points. The four Soddy lines concur at the de Longchamps point, the reflection of the orthocenter of the triangle about the circumcenter.
References
External links
Circles defined for a triangle
Circle packing | Soddy circles of a triangle | [
"Mathematics"
] | 1,021 | [
"Geometry problems",
"Circle packing",
"Mathematical problems",
"Packing problems"
] |
74,395,194 | https://en.wikipedia.org/wiki/Remote%20integration%20model | Remote integration model, also known as REMI and at-home production, is a method of live production for television broadcasts and video distribution that transmits live feeds to a single centralized production facility or workflow for integration into a finished feed, which is then distributed to broadcasters.
Initially developed as a less staff- and equipment-intensive alternative to on-site production of live sports events using production trucks or local studios, REMI grew in popularity in 2020 due to the impact of the COVID-19 pandemic on television, which required heavily isolated remote work. However, the practice — particularly in live sports productions — is subject to criticism for the compromises in image quality, stability, and the detachment of commentators and producers operating sometimes thousands of miles from the events they're covering.
History
NBC Sports deployed a remote production workflow for the 1996 Summer Olympics, which were hosted in Atlanta, Georgia. To reduce the amount of on-site staff needed to cover all events, producers instead had taped and time-shifted footage transmitted from events to a single centralized production facility at 30 Rockefeller Plaza in New York City nicknamed the "virtual International Broadcast Center", allowing on-site producers to focus on live broadcasts. NBC continued the practice in subsequent Olympic Games, and in 2013 established a permanent remote International Broadcast Center in Stamford, Connecticut.
Early REMI productions relied on high-bandwidth T1 lines and grew into higher-speed connections and IP routing capabilities as they became available, in order to accommodate increases in broadcast display resolution and the number of cameras in use.
Alongside the growth of in-house REMI studios, independent remote-production service providers expanded into providing full REMI services and commentary on contract to other events and leagues. For example, VISTA Worldlink, which had engaged in global-commentary rebroadcasts of Major League Soccer (MLS) and CONCACAF matches, expanded into providing full REMI services and commentary on contract to United Soccer League competitions, National Women's Soccer League (NWSL), the U.S. Open Cup, and MLS.
Lowering production costs
Sports leagues with smaller broadcast budgets began deploying REMI productions to allow for more live-broadcast and livestreamed matches. For example, with A+E as a broadcast partner in 2016, the National Women's Soccer League produced match livestreams using REMI practices with budgets as small as $10,000 per match, compared to $50,000 to $100,000 for television broadcasts using a production truck. The Premier Hockey Federation used REMI production to expand its match availability to its full season and produce its first linear television broadcasts. NASCAR consolidated its remote production to a studio in Charlotte, North Carolina, in 2019 where it produced 30 events remotely.
Use during the COVID-19 pandemic
The impact of the COVID-19 pandemic on television forced live event coverage to adapt to strict rules on isolation. Entities already using REMI methods were able to return to broadcasting events since most production staff and commentators already operated in remote, isolated facilities.
Isolation measures required to control the COVID-19 pandemic in 2020 and 2021 also led live television production companies to adopt REMI practices in sports and fields that previously had not deployed them. For example, NBC used practices from its Olympics coverage to produce college football broadcasts that had traditionally relied on extensive on-site production. ESPN migrated National Basketball Association coverage to REMI productions based in Bristol, Connecticut, continuing into the 2021–22 NBA season. The 47th Daytime Emmy Awards in 2020 adapted to REMI production after the in-person ceremony was cancelled.
Methods
In traditional remote broadcast production, multiple cameras routed to a vision mixer and microphones routed to a mixing console, operated by a technical director receiving orders from a director in an on-site studio or production truck (OB van) connected to a transmission network, either a fiber access or a satellite uplink via a SNG truck. A REMI workflow instead routes camera and audio feeds via dedicated fiber optic, communications satellite, or facility or cellular internet connections to a remote production center. Such consolidation allows one production staff and set of equipment to produce multiple events, in sequence or simultaneously, without traveling, setting up, and tearing down production equipment between events. For simple one-camera productions, only a single on-site camera operator might be necessary.
This workflow also allows commentators to call events from the live feeds without being on-site. For example, all NBC Sports commentary of the 2022 Winter Olympics in Beijing was done remotely.
REMI production methods can be further streamlined by use of cloud computing production tools, further eliminating part or all of the centralized production facility. BT Sport engaged a test of such a cloud-based workflow for a UEFA Youth League match using aggregated cellular links and local broadband to also eliminate the need for dedicated transport connections.
Drawbacks and criticism
REMI productions rely on IP transport from the venue to the remote production facility, which can be subject to outages if redundant transport methods aren't available on-site. Failures can result in compression artifacts or outages, which can affect the collection of sports analytics data and social media coverage of live events. Players in the NWSL complained when match footage was unavailable for review, or when camera angles weren't available to review goals or important plays.
Tight budgets facilitated by REMI production can result in low-quality productions that doesn't meet viewers' expectations, leading to organizers being forced to increase spending on equipment and on-site staff to compensate.
Off-site commentators are limited to what cameras and microphones can record and can be tasked with calling several consecutive games per day, leading to facutal errors, omissions, and mischaracterizations of an event's atmosphere. On-site staff can be subject to communications latency from off-site producers. Commentary can become sufficiently delayed from live events to be recognized by viewers. Viewers can also recognize attempts to make commentators sound or appear to be reporting live from an event when they're remote.
See also
Impact of the COVID-19 pandemic on television, and in the United States
Remote broadcast
Production truck
References
Broadcast engineering
Television technology | Remote integration model | [
"Technology",
"Engineering"
] | 1,249 | [
"Information and communications technology",
"Broadcast engineering",
"Electronic engineering",
"Television technology"
] |
74,395,207 | https://en.wikipedia.org/wiki/Misskey | Misskey () is an open source, federated, social networking service created in 2014 by Japanese software engineer Eiji "syuilo" Shinoda. Misskey uses the ActivityPub protocol for federation, allowing users to interact between independent Misskey instances, and other ActivityPub compatible platforms. Misskey is generally considered to be part of the Fediverse.
Despite being a decentralized service, Misskey is not philosophically opposed to centralization.
The name Misskey comes from the lyrics of Brain Diver, a song by the Japanese singer May'n.
History
Misskey was initially developed as a BBS-style internet forum by high school student Eiji Shinoda in 2014. After introducing a timeline feature, Misskey gained popularity as the microblogging platform it is today.
In 2018, Misskey added support for ActivityPub, becoming a federated social media platform.
The flagship Misskey server, Misskey.io, was started on April 15, 2019.
Misskey, alongside Mastodon and Bluesky, has received attention as a potential replacement for Twitter following Twitter's acquisition by Elon Musk in 2022.
On April 8, 2023, Misskey.io incorporated as MisskeyHQ K.K. As of February 2024, over 450,000 users were registered, making it the largest instance of Misskey. Misskey.io is crowdfunded. The administrator of Misskey.io is Japanese system administrator Yoshiki Eto, who operates under the alias Murakami-san. Eiji Shinoda serves as director.
In July 2023, Twitter introduced extreme restrictions on their API in order to combat scraping from bots. Some users were critical of the changes, and as a result migrated to other social networks. The number of users registering on Misskey.io, Misskey's official instance and the largest one, increased rapidly, with other Misskey instances also receiving a spike in signups. In response to this trend, Skeb, a platform for sharing art, announced on July 14, 2023 that it would sponsor the Misskey development team.
In early 2024, Misskey was targeted by a spam attack from Japan. The cause of the attack is believed to be a dispute between rival groups on a Japanese hacker forum and a DDoS attack on a Discord bot. Mastodon instances with open registration were used in the attack.
Development
Misskey is open source software and is licensed under the AGPLv3. The Misskey API is publicly available and is documented using the OpenAPI Specification, which allows users to build automated accounts and use it on any Misskey instance. The service is translated using Crowdin.
Misskey is developed using Node.js. TypeScript is used on both the frontend and backend. PostgreSQL is used as its database. Vue.js is used for the frontend.
Functionality
Posts on Misskey are called "notes". Notes are limited to a maximum of 3,000 characters (a limit which can be customized by instances), and can be accompanied by any file, including polls, images, videos, and audio. Notes can be reposted, either by themselves or with another "quote" note.
Misskey comes with multiple timelines to sort through the notes that an instance has available, and are displayed in reverse chronological order. The Home timeline shows notes from users that you follow, the Local timeline shows all notes from the instance in use, the Social timeline shows both the Home and Local timeline, and the Global timeline shows every public note that the instance knows about.
Notes have customizable privacy settings to control what users can see a note, similar to Mastodon's post visibility ranges. Public notes show up on all timelines, while Home notes only show on a user's Home timeline. Notes can also be set to be available only for followers. Direct messages using notes can be sent to users.
Forks
Misskey's open source nature has led to the development of a number of forks:
Firefish (formerly Calckey) has been developed by ThatOneCalculator since 2022. Firefish includes enhanced compatibility with the Mastodon API. Further development of the project is discontinued due to a lack of maintainers and code quality issues, as well as the sudden disappearance of ThatOneCalculator.
Foundkey was primarily developed by Johann155, a contributor to Misskey. The fork was started as a result of various language barriers in regards to Misskey's development, as a result of an overwhelming amount of it being conducted exclusively in Japanese. Development is currently paused, and it has been advised to not use Foundkey with more than 20 users.
Iceshrimp, forked from Firefish in 2023. The project is currently in the process of being rewritten into C# and .NET.
Sharkey, developed by Transfem.org. Main features include note editing, local-only notes and compatibility with the Mastodon API.
See also
ActivityPub
Bluesky
Comparison of microblogging and similar services
Comparison of software and protocols for distributed social networking
Fediverse
Mastodon
References and notes
External links
Official website (in English)
2014 software
Software that federates via ActivityPub
Free and open-source software
Free software programmed in TypeScript
Free software websites
Microblogging software
Social media
Social networking services
Web applications | Misskey | [
"Technology"
] | 1,104 | [
"Computing and society",
"Computing websites",
"Free software websites",
"Social media"
] |
77,320,385 | https://en.wikipedia.org/wiki/Mapleton%20train%20collision | On 27 July 1927, a catastrophic head-on train collision occurred on the single-track railway line between Durban and Johannesburg, South Africa, near Roodekop in Germiston. The accident involved a southbound goods train and a northbound passenger train.
Collision
The collision was primarily attributed to a critical error made by the driver of the southbound goods train departing from Roodekop. The driver, carrying the staff which authorised him to travel only as far as a newly added side track, apparently forgot to wait there for the northbound train from Durban. This oversight led to both trains being on the same track simultaneously, resulting in a devastating collision.
Casualties
The collision had tragic consequences. A total of 29 people lost their lives, with some succumbing to exposure to the harsh winter weather while waiting for rescue teams to arrive. Additionally, 54 individuals sustained injuries of varying severity.
Locomotives Involved
One of the locomotives involved in the collision was the SAR A Class 4-8-2T No. 196, manufactured by Dubs & Co. (Dubs No. 3819).
References
Train collisions in South Africa | Mapleton train collision | [
"Technology"
] | 225 | [
"Railway accidents and incidents",
"Rail accident stubs"
] |
77,321,191 | https://en.wikipedia.org/wiki/Light%20scanning%20photomacrography | Light Scanning Photomacrography (LSP), also known as Scanning Light Photomacrography (SLP) or Deep-Field Photomacrography, is a photographic film technique that allows for high magnification light imaging with exceptional depth of field (DOF). This method overcomes the limitations of conventional macro photography, which typically only keeps a portion of the subject in acceptable focus at high magnifications.
Historical background
The principles of LSP were first documented in the early 1960s by Dan McLachlan Jr., who highlighted its capability for extreme focal depth in microscopy
and in 1968 patented the process.
The technique was revived and further developed in the 1980s by photographers such as Darwin Dale and Nile Root, a faculty member at the Rochester Institute of Technology. In the early 1990s, William Sharp and Charles Kazilek, both researchers at Arizona State University, also published articles describing their technique and system setup for capturing SLP images.
Predecessor to stack image photography
Light Scanning Photomacrography offered a powerful analog tool for high-detail imaging in the age of film photography. It provided a comprehensive depth of field, making it invaluable in scientific and biomedical photography. As technology and techniques continue to evolve, LSP has been replaced by digital image focus stacking. This technique uses a collection of images captured in series at different focal depths, which are then processed using computer software to create a single image with a greater focus depth than any single image.
LSP technique and results
LSP involves the use of a thin plane of light that scans across the subject, which is mounted on a stage moving perpendicular to the film plane. The technique utilizes traditional optics and is governed by the physical laws of depth of field. By moving the subject through a narrow band of illumination, the entire subject can be recorded in sharp focus from the nearest details to the farthest ones. This analog process produces sharp and detailed images by slowly recording the image on film as the specimen passes through the sheet of light that is thinner than the effective DOF.
Because the image is captured at the same relative distance from the camera lens, the resulting images are axonometric rather than perspective projection, which is what the human eye sees and is typically captured by a film camera. Because all parts of an LSP image are captured at the same distance from the lens, relative measurements can be taken from an LSP photograph and can be used for comparison.
Equipment and setup
A typical LSP setup includes:
A stage that can move the subject perpendicular to the film plane.
Light sources, in some cases modified projectors, are used to project a thin plane of light.
A camera mounted on a stable stand such as a tabletop copy stand.
In 1991, Sharp and Kazilek described their SLP system that used three Kodak Ektagraphic slide projectors with zoom lenses to create a thin plane of light. The projectors each had a slide mount with two razor blades placed edge-to-edge to create a thin slit for the light to pass through. The image was captured using a Nikon FE-2 SLR camera mounted above the specimen. Kodachrome 25 slide film was used to record the image and to minimize film grain size and maximize image sharpness
Commercial systems
A commercial SLP instrument was produced by the Irvine Optical Corp. Their DYNAPHOT system was based on a photomacroscope and could capture images on 4x5 film. The instrument came with two or three illumination sources and a motorized specimen stage. The system advertised a 2X – 40X magnification range and the ability to capture images in black and white and color. Other systems have been developed by Nile Root and Theodore Clarke and reported higher magnification (up to 100X).
LSP process
Alignment and Focusing: The light sources are aligned and focused to project a thin, consistent plane of light across the subject.
Stage Movement: The subject stage moves at a controlled speed, scanning through the plane of light.
Image Capture: The camera shutter is set to a long exposure or can be opened and closed manually. As the subject moves through the illuminated plane, it is recorded on the film. This process is very much like painting an image onto the film using photons instead of paint.
Applications
LSP was particularly useful in biomedical photography, where it was used to document magnified subjects with increased depth of field over traditional macro and micro photography. It has been employed to capture detailed images of biological specimens, such as imaging small insects and their parts. SLP has been used to document shell collections for scientific documentation and research. Other applications include forensic science, mineralogy, and the imaging of fractured surfaces and parts
Advantages and challenges of LSP imaging
Advantages
Exceptional depth of field: Subjects are rendered in sharp focus throughout.
High magnification: Detailed images at significant magnification without sacrificing DOF.
Analog precision: Provides a non-digital solution with accurate image representation.
Versatility: Can be used for a range of subject sizes, from macro to non-macro scales.
Challenges
Technical complexity: Requires precise setup and alignment.
Exposure time: Typically requires long exposure times due to the scanning process.
Contrast control: The highly directional lighting can create harsh shadows and high contrast, which may need to be managed.
Digital competition: Focus stacking has largely replaced LSP in the digital era due to convenience and flexibility.
DIY contributions
Enthusiasts and researchers have contributed to the development and accessibility of LSP by creating and sharing DIY guides. These contributions have enabled others to build their own LSP systems using readily available materials and components. Nile Root's publications provide detailed instructions and recommendations for constructing an LSP setup. These DIY systems have allowed a wider audience to explore and utilize the benefits of LSP imaging in various fields.
See also
Focus stacking
References
Image processing
Microscopy
Optical imaging
Photographic techniques
Science of photography
Scientific techniques | Light scanning photomacrography | [
"Chemistry"
] | 1,192 | [
"Microscopy"
] |
77,321,735 | https://en.wikipedia.org/wiki/COCONet | Continuously Operating Caribbean GPS Observational Network (COCONet) was a global positioning system (GPS) observation network that spanned across the Caribbean and the neighboring area It was part of UNAVCO (University Navstar Corporation). UNAVCO and IRIS (Incorporated Research Institutions for Seismology) Consortium later merged to create EarthScope Consortium in 2023.
The project was initiated after the devastation of the 2010 Haiti Earthquake, which was a 7.0 Mw earthquake. Starting from 2011, UNAVCO built and operated COCONet for the National Science Foundation (NSF). It was a network of continuous GPS meteorology or cGPS/Met sites. Along with the NSF-funded TLALOCNet GPS network in Mexico, the two networks of cGPS-Met instrumentation were available to support research in Mexico, Central America, and the Caribbean.
Function
The purpose of COCOnet was to:
Provide details on the tectonics of the entire Caribbean region.
Enhance atmospheric observations that can be used for testing and validation of climate and weather models.
Improve the analysis of local geodetic (the science of planetary measurement) measurements by providing access to an integrated backbone electronic network of reference stations.
Increase our ability to model and predict the natural hazards (earthquakes, hurricanes and so on) in the region.
To accomplish the function of climate modeling and other objectives., the network also had tide gauges in Mexico, Jamaica, the Dominican Republic, and Panama. In terms of atmospheric measurements and related goals, the COCOnet stations were able to assist the Constellation Observing System for Meteorology, Ionosphere, and Climate of the University Corporation for Atmospheric Research (UCAR/COSMIC) as it created continuous estimates of precipitable water vapor.
Stations
A notable station is the station on the isolated Isla del Coco (Cocos Island), Costa Rica, in that it is the only GPS station continuously tracking the Cocos Plate, as it passes underneath the Caribbean Plate, at a rate of 78 millimeters (mm) per year. Because the island is the only land mass of the Cocos Plate that is above sea level, this was the only place where Cocos Plate motion observations could be measured in this GPS network. A continuous GPS station was built and instrumented on the island in May 2011. Data from the station show a steady motion of the island at a speed of 90.9±1.5mm/yr. or approximately 90 millimeters a year.
Partnerships
The following organizations were members of the partnership for the network when it had existed:
Universidad Politécnica de Ingeniería (UPI) (Honduras)
Puerto Rico Seismic Network
Instituto Sismológico Universitario (ISU) - Autonomous University of Santo Domingo (UASD)
Oficina Nacional de Meteorología (ONAMET) (Dominican Republic)
University of Zulia, Venezuela
National Meteorological Service (Mexico)
Nicaraguan Institute of Territorial Studies Intra-Americas Studies of Climate Processes
Jamaica Climate Service
Pennsylvania State University
State University Haiti
Colombian Institute for Hydrology, Meteorology and Environmental Studies
Geographic Institute of Venezuela Simón Bolívar
Venezuelan Foundation for Seismological Research
National Geographic Institute of El Salvador
University of Texas, Arlington
Camagüey Meteorological Center (Camagüey, Cuba)
National Geographic Institute of Honduras
Panama Canal Authority
Caribbean Community Climate Change Centre, Belize
Volcanological and Seismological Observatory of Costa Rica
University of the West Indies - Seismic Research Center
Institut de Physique du Globe de Paris
Montserrat Volcano Observatory (Caribbean island of Montserrat)
Purdue University
University of Puerto Rico, Mayagüez
Meteorological Service of the Netherlands, Antilles, and Aruba
University of Arizona
University of Technology, Jamaica
Colombian Institute of Geology and Mining
National Geographic Institute, Guatemala City
National Autonomous University of Honduras
University Corporation for Atmospheric Research (UCAR)
National Autonomous University of Mexico (UNAM)
National Oceanic and Atmospheric Administration (NOAA)
U.S. Geological Survey (USGS)
National Aeronautics and Space Administration (NASA)
National Science Foundation (NSF)
Bahamas Department of Meteorology
Meteorological Department Curaçao
Earthquake Unit, Jamaica
Real Estate Jurisdiction of the Dominican Republic
Universidad Nacional Pedro Henriquez Ureña (UNPHU) (Dominican Republic)
Meetings and workshops
COCOnet had held for workshops. The meetings can help to understand the history of the project:
The original COCONet project proposal was covered in three workshops:
The first one was planned to be held in San Juan, Puerto Rico (February 3–4, 2011)
The second meeting was to be held in Port-of-Spain, Trinidad, Republic of Trinidad & Tobago (June 28–29, 2011) with one of several goals being for Caribbean network operators to address the specifics of choosing existing and new stations.
The third COCONet workshop focused primarily on longer-term operations and maintenance for GPS stations installed in the Caribbean, and related issues.
Data centers
The following were the data centers:
Servicio Geólogico Colombiano (SGC) (Columbian Geological Survey) - Regional Data Center
Caribbean Institute for Meteorology & Hydrology (CIMH), Barbados - Regional Data Center
Instituto Nicaragüense de Estudios Territoriales (INETER) - Regional Data Center
Last publications and workshops
The last publications and workshops of COCOnet were the following:
The last workshop was COCONet - Results, Sustainability, and Capacity Building, which had been held May 3–5, 2016 in Punta Cana, Dominican Republic.
References
Geophysical observatories
Seismology instruments
Geology
Geophysics | COCONet | [
"Physics",
"Technology",
"Engineering"
] | 1,113 | [
"Seismology instruments",
"Applied and interdisciplinary physics",
"Measuring instruments",
"Geophysics"
] |
77,323,731 | https://en.wikipedia.org/wiki/NGC%205504 | NGC 5504 is an intermediate barred spiral galaxy located in the constellation Boötes. Its speed relative to the cosmic microwave background is 5,482 ± 17 km/s, which corresponds to a Hubble distance of 80.9 ± 5.7 Mpc (∼264 million ly). NGC 5504 was discovered by French astronomer Édouard Stephan in 1880.
The luminosity class of NGC 5504 is II-III and it has a broad HI line.
Supernova
Supernova SN 2013bb (type IIb, mag. 18.4) was discovered in NGC 5504 on April 3, 2013, as part of Caltech's Catalina Real-Time Transient Survey (CRTS) and by Stan Howerton.
NGC 5504 group
The galaxies IC 4383 and PGC 50713 are located in the same region of the sky as NGC 5504 and their radial speed respectively equal to (5,230 ± 4) km/s and (5,249 ± 6) km/s places them approximately at the same distance as NGC 5504. These three galaxies therefore form a triplet of galaxies, the group of NGC 5504, the brightest of the three galaxies.
This group of galaxies is designated as WBL 494 in the article by White published in 1999. IC 4383 is also designated as NGC 5504B and as WBL 494–001 by the NASA/IPAC database while PGC 50713 is designated as NGC 5504C and as WBL 494–003.
See also
List of NGC objects (5001–6000)
External links
NGC 5504 at NASA/IPAC
NGC 5504 at VizieR
NGC 5504 at SIMBAD
NGC 5504 at LEDA
References
Spiral galaxies
Boötes
Discoveries by Édouard Stephan
5504
09085
+03-36-081
050718 | NGC 5504 | [
"Astronomy"
] | 377 | [
"Boötes",
"Constellations"
] |
77,323,818 | https://en.wikipedia.org/wiki/VITEK | VITEK refers to a series of automated microbiology analyzers for microbial identification (ID) and antibiotic sensitivity testing (AST).
History
Vitek was developed in the 1960s between NASA and the defense contractor McDonnell Douglas. For the Voyager program, McDonnell Douglas developed a Microbial Load Monitor (MLM) to detect bacterial contamination aboard the spacecraft. Under a subsequent NASA contract, McDonnell Douglas explored expanding the MLM to detecting and identifying bacterial infections among the crew of a human mission to Mars. The initial system was called the Microbial Load Monitor (MLM) and could detect nine common pathogens of Urinary tract infections (UTIs). In 1977, a new subsidiary was formed around the product, Vitek Systems, and the system was renamed the VITEK meaning "life technology", a portmanteau of Latin Viv, meaning life, and TEK being short for technology. In 1979, Vitek began selling the AutoMicrobic System (AMS) to hospital laboratories.
In 1989, Vitek Systems was sold to bioMérieux.
In March 2005, the Vitek 2 Compact received FDA clearance.
References
Microbiology analyzer | VITEK | [
"Biology"
] | 237 | [
"Microbiology analyzer",
"Microbiology equipment"
] |
77,325,638 | https://en.wikipedia.org/wiki/Layered%20costmaps | Layered costmaps is a method to create and update maps for robot navigation and path planning proposed by David V. Lu in 2014. During robot navigation, layered costmaps can abstract the realistic environment around the robot into maps that can be comprehended by robot navigation methods. The method consists of more than one layer of costmaps, each of which describes obstacles with different properties. Each layered costmap consists of grids and is represented as a matrix, the values of the matrix elements are related to the risks of grids (the higher the value,the greater the risk and the deeper the colour in the grid). In the layered costmap, the colour of a grid indicates the risk of moving through that grid. There is a high probability of robot collision when the robot moves through a grid with deep colour. When updating a layered costmap, only the area covered by the sensors (such as Lidar) in the map is updated, rather than the entire map.
Standard Layers
Layered costmaps is a flexible method, and special categories of layered costmaps can be designed and added to the method depending on the navigation environment of the mobile robot. In Robot Operating System (ROS), some categories of layered costmaps are provided for mobile robot navigation, and they are also the standard layers that are added in most cases.
Static Map Layer
The static map layer is at the bottom among all layered costmaps, and it includes the situation of all known static obstacles in the environment before navigation starts. The static map layer can be generated with a SLAM algorithm or can be created from an architectural diagram.
If in the static map matrix , the real location corresponds to the element index , then an example of the static map layer defining rules is as follows:
Obstacles Map Layer
The obstacles map layer describes the situation of obstacles detected by sensors during robot navigation. Since the observation distance of the sensor is limited, the obstacles map layer can only be updated in the observation area of the sensor.
Assume that there is only one sensor in the scene and it is equipped on the robot, its observation area is a square with side length , and the location of the robot is . If in the obstacles map matrix , the real location corresponds to the element index , then an example of the obstacles map layer defining rules is as follows:
where meets that and .
Inflation Layer
The inflation layer inserts a buffer zone around each obstacle in order to keep the robot from getting too close to obstacles. Note that these obstacles include obstacles described in the static map layer and the obstacles map layer. In the inflation layer, the grids that are further away from the obstacles have the lower cost.
The inflation rule used in the inflation layer is flexible and can be freely designed according to the features of the environment and the robot. For example, a simple inflation rule can be designed with two thresholds and a function. Assume that the maximum radius of the robot is . If in the inflation matrix , the real location corresponds to the element index , then an example of the inflation rules is as follows:
where the function represents the distance between point and the nearest obstacle.
Social Navigation Layers
Although social navigation layers are not as necessary as standard layers, when there are pedestrians in the environment, by adding social navigation layers, more information can be included in the map. In standard layers, the speed of obstacles is not considered, but in social navigation layers, the speed of obstacles (i.e., pedestrians) is considered and reflected in costmap layers combined with the social habits of pedestrians.
Proxemic Layer
The proxemic layer reflects the social habits to the surroundings of pedestrians in both moving and stationary situations.
The moving pedestrians do not want obstacles appearing in their moving direction, so in the proxemic layer, the cost in the moving direction of the moving pedestrians becomes larger.
The stationary pedestrians do not want robots approaching them from behind, which will make them feel uncomfortable, so in the proxemic layer, the cost in the back direction of the stationary pedestrians becomes larger.
Passing Layer
As in many countries, traffic rules require drivers to drive on the right side of the road, there is the custom of walking on the right side of pathways in many cultures. In order to obey this social habit of pedestrians as much as possible, the pass layer has a higher cost on the right side of pedestrians, guiding the robot to pass by the left side of pedestrians when it is possible.
After layered costmaps
After the creation, the layered costmaps will be continuously updated based on the information provided by the sensors, and the navigation algorithm will drive the robot to reach the destination without collision based on the information provided by the layered costmaps.
Applications
Layered costmaps is the default map creation method when ROS, a popular robot control software framework, controls mobile robots for navigation. The robot developers can control the robots (such as TurtleBot) through ROS to navigate in scenes indoors or outdoors, with or without people. During the navigation process, the layered costmaps will be constantly updated to provide information about the surrounding environment to the robot.
Advantages and disadvantages
Advantages
Layered costmaps is very flexible, specific costmap layers can be added, modified and deleted freely according to the requirements, thus flexibly adapting to different navigation environments.
Layered costmaps can be updated quickly because only the area covered by the sensors needs to be updated, which allows the robot to have a shorter response time in emergency situations.
disadvantages
All costmaps in layered costmaps have the same size and resolution, which causes a large space to store the data when the method is in operation.
See also
Robot Operating System
Robot navigation
motion planning
Human–robot interaction
SLAM
Lidar
References
Further reading
External links
Real-Time Avoidance of Ionising Radiation Using Layered Costmaps for Mobile Robots on ResearchGate
ROS wiki Documentation on ROS wiki
Robot navigation
Robotics engineering | Layered costmaps | [
"Technology",
"Engineering"
] | 1,202 | [
"Computer engineering",
"Robotics engineering"
] |
77,326,358 | https://en.wikipedia.org/wiki/Balanced%20category | In mathematics, especially in category theory, a balanced category is a category in which every bimorphism (a morphism that is both a monomorphism and epimorphism) is an isomorphism.
The category of topological spaces is not balanced (since continuous bijections are not necessarily homeomorphisms), while a topos is balanced. This is one of the reasons why a topos is said to be nicer.
Examples
The following categories are balanced:
Set, the category of sets.
Grp, the category of groups.
An abelian category.
CHaus, the category of compact Hausdorff spaces (since a continuous bijection there is homeomorphic).
An additive category may not be balanced. Contrary to what one might expect, a balanced pre-abelian category may not be abelian.
A quasitopos is similar to a topos but may not be balanced.
See also
quasi-abelian category
References
Sources
Roy L. Crole, Categories for types, Cambridge University Press (1994)
Further reading
Category theory | Balanced category | [
"Mathematics"
] | 215 | [
"Functions and mappings",
"Mathematical structures",
"Category theory stubs",
"Mathematical objects",
"Fields of abstract algebra",
"Mathematical relations",
"Category theory"
] |
77,326,503 | https://en.wikipedia.org/wiki/Negative%20air%20ions | Negative air ions (NAI) are important air component, generally referring to the collections of negatively charged single gas molecules or ion clusters in the air. They play an essential role in maintaining the charge balance of the atmosphere. The main components of air are molecular nitrogen and oxygen. Due to the strong electronegativity of oxygen and oxygen-containing molecules, they can easily capture free electrons to form negatively charged air ions, most of which are superoxide radicals ·O2−, so NAI is mainly composed of negative oxygen ions, also called air negative oxygen ions.
Research history
In 1889, German scientists Elster and Geitel first discovered the existence of negative oxygen ions.
At the end of the 19th century, German physicist Philipp Eduard Anton Lenard first explained the effects of negative oxygen ions on the human body in academic research. In 1902, scholars such as Ashkinas and Caspari further confirmed the biological significance of negative oxygen ions. In 1932, the world's first medical negative oxygen ions generator was invented in the United States.
In the middle of the 20th century, Professor Albert P. Krueger of the University of California, Berkeley, conducted pioneering research and experiments on the biological effects of ions at the microscopic level. Professor Krueger demonstrated the impact of negative oxygen ions on humans, animals, and plants from the aspects of biological endocrine, internal circulation, and the generation reactions of various enzymes through a large number of animal and plants experiments.
From the end of the 20th century to the beginning of the 21st century, many experts, scholars, and professional medical institutions applied negative ions (negative oxygen ions) technology to clinical practice. Through various explorations, new ways of treating diseases were opened up.
In 2011, the official website of the China Air Negative Ion (Negative Oxygen Ion) and Ozone Research Society was launched. This website is the first negative ions industry website in China, and its purpose is to rapidly promote the orderly development of the air negative ion (negative oxygen ion) industry. In 2020, the Tsinghua University successfully developed a medical-grade high-concentration negative oxygen ion generator. It only needs to be sprayed on the room's walls to form a uniform and dense layer of nanoparticles on the wall, allowing the indoor wall to stably and long-term release high-concentration small-particle negative oxygen ions.
Generation mechanism
Common gases that produce negative air ions include single-component gases such as nitrogen, oxygen, carbon dioxide, water vapor, or multi-component gases obtained by mixing these single-component gases. Various negative air ions are formed by combining active neutral molecules and electrons in the gas through a series of ion-molecule reactions.
In the air, due to the presence of many water molecules, the negative air ions formed are easy to combine with water to form hydrated negative air ions, which are typical negative air ions, such as O−·(H2O)n, O2−·(H2O)n, O3−·(H2O)n, OH−·(H2O)n, CO3−·(H2O)n, HCO3−·(H2O)n, CO4−·(H2O)n, NO2−·(H2O)n, NO3−·(H2O)n, etc. The ion clusters formed by the combination of small ions and water molecules have a longer survival period due to their large volume and the fact that the charge is protected by water molecules and is not easy to transfer. This is because in the molecular collision, the larger the molecular volume, the less energy is lost when encountering collisions with other molecules, thereby extending the survival time of negative air ions.
Generation methods
Negative air ions can be produced by two methods: natural or artificial.The methods of producing negative air ions in nature include the waterfall effect, lightning ionization, plants tip discharge, etc. Natural methods can produce a large number of fresh negative air ions. The artificial means of producing negative air ions include corona discharge, water vapour，and other methods. Compared with the negative air ions produced in nature, although artificial methods can produce high levels of negative air ions, there are specific differences in the types and concentrations of negative air ions, which makes the negative air ions produced by artificial methods may not achieve the excellent environmental health effects of negative air ions produced in nature. Improving the artificial method to produce ecological-level negative ions is necessary.
Natural environments
Waterfall method : When people are in a water-rich environment such as a waterfall, fountain, or seaside, they usually feel relaxed and release stress, which is related to many negative air ions in the environment, as one of the most common methods for producing negative air ions in nature.
The mechanism of producing negative air ions by the waterfall method was first discovered by German scientist Lenard in 1915. The Lenard effect is achieved through two methods: the rupture of the "ring-bag" structure and the local protrusion separation. The "ring-bag" structure rupture theory believes that during the collision between water and gas, the water droplets will form a "U"-shaped intermediate with a "ring-bag" structure when subjected to external impact. The intermediate will then break apart to form small droplets with negative charges and large droplets with positive charges. The local protrusion separation theory believes that when water droplets collide with each other or are subjected to external forces, the water droplets will automatically protrude locally and generate negative charge aggregation. When subjected to shear force, this part will form negative ions with crystal water and be released into the air.
Lightning strike method : The atmosphere itself is a huge electric field. Positive and negative charges will accumulate above and below the clouds. When the droplets in the clouds continue to accumulate and gradually approach the ground due to gravity, a giant capacitor will be formed between the clouds and the ground. When the electric field strength between the two exceeds the dielectric strength of the air, discharge will occur and break through the air. During the lightning discharge process, charged particles bombard the surrounding air molecules, ionizing the molecules to generate negative air ions. At the moment of the lightning strike, hundreds of millions of negative air ions will be generated. This is why people feel the air is fresh and clean after rain. It is not only because the rain increases the humidity of the air, but more importantly, the concentration of negative ions in the air has increased significantly.
Plants tip discharge : The tip of the leaves of vegetation will discharge under the action of the photoelectric effect. Like the corona discharge, the needle tip will continue to ionize and release negative air ions. In addition, the reason why negative air ions can maintain a high concentration for a long time in forests and some areas covered by green vegetation is that the oxygen concentration released by vegetation during photosynthesis is much higher than that in cities, and a large amount of water vapor is released through respiration and leaf transpiration. Oxygen and water vapor can produce free electrons under ionization. Due to their strong electronegativity, water molecules and oxygen molecules can easily capture free electrons to form negative air ions.
Artificial ionization
Corona discharge method : Currently, the most common artificial method is to use corona discharge to produce negative ions. The specific process of using corona discharge to produce gaseous negative ions is to connect the high-voltage negative electrode to a thin needle-shaped wire or a conductor with a very small radius of curvature, so that a strong electric field is generated near the electrode, releasing high-speed electrons. The speed is enough to drive the electrons to collide with gas molecules, further ionize, and produce new free electrons and positive ions. The newly generated free electrons will repeat the previous process, continue to collide and ionize, and this process will be repeated many times, so that the tip electrode will continuously release negative air ions.
The water vapour method : The water vapour method refers to the use of artificial technology and modern instruments to simulate the principle of waterfall generation, using high-speed airflow to collide with water droplets, dispersing larger water droplets into a large number of microdroplets. As the water droplet dispersion process, the Leonard effect occurs, generating negative ions.
Determination method
Detection of negative air ions is divided into measurement and identification. NAI measurement can be achieved by measuring the change in atmospheric conductivity when NAI passes through a conductive tube. NAI identification is generally achieved using mass spectrometry, which can effectively identify a variety of negative ions, including O−,O2−,O3−,CO3−,HCO3−,NO3−, etc.
Application of negative air ions
Health Promotion
The effects of NAI on human/animal health are mainly concentrated on the cardiovascular and respiratory systems and mental health. The impacts of NAI on the cardiovascular system include improving red blood cell deformability and aerobic metabolism and lowering blood pressure. In terms of mental health, a experiments have shown that after exposure to NAI, performance on all the experimenters test tasks (mirror drawing, rotation tracking, visual reaction time and hearing) was significantly improved, and symptoms of seasonal affective disorder (SAD) were alleviated. The effects of NAI in relieving mood disorder symptoms are similar to those of antidepressant non-drug treatment trials, and NAI have also shown effective treatment for chronic depression.
Environmental Improvement
Negative air ions can be effectively used to remove dust and settle harmful pollutants such as PM. In particular, they can significantly degrade indoor pollutants, improve people's indoor living environment, and purify air quality. Some experts and scholars have used a corona-negative ions generator to conduct experiments on particles sedimentation through three steps: charging, migration, and sedimentation. They found that charged PM will settle faster or sink faster under the action of gravity so that PM will settle/precipitate faster than uncharged PM. In addition, experimental studies have shown that negative air ions have a specific degradation effect on chloroform, toluene, and 1,5-Hexadiene and produce carbon dioxide and water as final products through the reaction.
See also
Air ioniser
Ion
Negative air ionization therapy
References
External links
Atmosphere
Natural environment
Biophysics
Health care
Air pollution
Biochemistry | Negative air ions | [
"Physics",
"Chemistry",
"Biology"
] | 2,119 | [
"Biochemistry",
"nan",
"Applied and interdisciplinary physics",
"Biophysics"
] |
77,326,711 | https://en.wikipedia.org/wiki/Magnetization%20roasting%20technology | Magnetic roasting technology refers to the process of heating materials or ores under specific atmospheric conditions to induce chemical reactions. This process selectively converts weakly magnetic iron minerals such as hematite (Fe2O3), siderite (FeCO3), and limonite (Fe2O3·nH2O) into strongly magnetic magnetite (Fe3O4) or maghemite (γ-Fe2O3), while the magnetic properties of gangue minerals remain almost unchanged.
By artificially increasing the magnetic disparity between iron oxides and gangue minerals through magnetic roasting, the selectivity of iron ore is improved, making it the most effective method for separating refractory iron ores. Additionally, the roasting process can eliminate harmful impurities such as crystalline water, sulfur, and arsenic from the ore, loosening the ore structure and enhancing subsequent grinding efficiency.
Researchers in mineral processing have been developing magnetic roasting technology for iron ore since the early 20th century. Depending on the type of reactor used, magnetic roasting can be classified into shaft furnace roasting, rotary kiln roasting, fluidized bed roasting, and microwave roasting.
Types
Shaft furnace magnetic roasting
Shaft furnace magnetization roasting is a metallurgical process, mainly used to treat iron ore, so that in a high temperature environment by reacting with reducing agents (such as coal, coke or gas), the iron oxides (such as hematite, limonite, etc.) to reduce to magnetic iron minerals (mainly magnetite). The process is usually carried out in the vertical furnace, the charge is top-down under the action of gravity, through layer by layer heating and reduction reaction, and finally obtain magnetic iron ore, so as to improve its magnetic separation performance, and facilitate the subsequent beneficiation and smelting process.
The main steps of magnetizing roasting in shaft furnace include:
Charge preparation: Mix iron ore with reducing agent in a certain proportion.
Heating: The charge is added from the top of the shaft furnace and heated layer by layer as it falls to a roasting temperature (usually between 700 °C and 900 °C).
Reduction reaction: The iron oxide in the ore reacts with the reducing agent and is reduced to magnetic iron minerals (such as magnetite).
Cooling and discharge: The roasted material is cooled and discharged from the bottom of the shaft furnace.
Rotary Kiln Magnetic Roasting
Magnetization roasting in rotary kiln is to reduce iron oxides (such as hematite, limonite, etc.) in the ore to magnetic iron minerals (mainly magnetite) by reacting iron ore containing iron ore with reducing agents (such as coal, coke or natural gas) in a rotating high-temperature kiln. This process helps to improve the magnetic separation performance of iron ore and facilitate subsequent beneficiation and smelting operations..
The main steps of magnetization roasting in rotary kiln include:
Raw material preparation: Mix the iron ore with the appropriate amount of reducing agent, and add the binder if necessary to improve the roasting effect.
Feed: The mixture is uniformly fed into the kiln head of the rotary kiln through the feed device.
Roasting: The rotary kiln is rotated at high temperatures (usually between 700 °C and 900 °C), and the material is continuously rolled and moved forward in the kiln, in full contact with the reducing atmosphere, so that the iron oxide is reduced to magnetic iron minerals (such as magnetite).
Cooling and discharge: The calcined material is cooled by a cooling system (such as a cooling kiln or cooling cylinder) and discharged from the end of the rotary kiln.
Fluidized bed magnetic roasting
Fluidized bed magnetic roasting is the use of suspension roaster to fully mix and contact fine ore with reducing agents (such as pulverized coal, natural gas, etc.) in high temperature environment, so that the iron oxides in the ore (such as hematite, limonite, etc.) are reduced to magnetic iron minerals (mainly magnetite), thereby improving the magnetic separation performance of the ore and facilitating subsequent beneficiation and smelting operations.
The main steps of suspension magnetization roasting include:
Raw material preparation: Mix iron ore powder with reducing agent, add auxiliary agent if necessary to improve roasting effect.
Roasting: The mixed material is suspended in the baking furnace by air flow, and at high temperatures (usually between 700 °C and 900 °C), the material is fully in contact with the reducing gas, and the reduction reaction is carried out to convert the iron oxide into magnetic iron minerals.
Cooling and collection: The roasted material is cooled by a cooling system and collected by equipment such as a cyclone or a cloth bag collector.
Microwave magnetic roasting
Microwave magnetization roasting uses microwave as an energy source to reduce iron oxides (such as hematite, limonite, etc.) in iron ore to magnetic iron minerals (mainly magnetite). In this process, the ore is rapidly heated, so that the reduction reaction is completed in a short time, so as to improve the magnetic separation performance of the ore, and facilitate subsequent beneficiation and smelting operations.
The main steps of microwave magnetization roasting include:
Raw material preparation: Mix iron ore powder with reducing agent (such as toner, pulverized coal, etc.) evenly.
Microwave heating: The mixture is placed in a microwave oven and heated by microwave radiation. Microwave energy acts directly on the material to rapidly heat it to the desired roasting temperature (usually between 500 °C and 900 °C).
Reduction reaction: At high temperatures, iron oxides and reducing agents undergo a reduction reaction to produce magnetic iron minerals (such as magnetite).
Cooling and collection: The roasted material is cooled by a cooling system and collected for treatment
Magnetization roasting method
The commonly used magnetization roasting methods can be divided into reduction roasting, neutral roasting, oxidation roasting, redox roasting and reduction oxidation roasting.
Reduction roasting
After heating to a certain temperature, hematite, limonite and iron-manganese ore can be transformed into strong magnetic magnetite by reacting with an appropriate amount of reducing agent. Commonly used reducing agents are C, CO, H2 and so on. The reaction of hematite with reducing agent is as follows:
3 Fe2O3 + C -> 2 Fe3O4 + CO
3 Fe2O3 + CO -> 2Fe3O4 + CO2
3 Fe2O3 + H2 -> 2 Fe3O4 + H2O
Neutral roasting
Carbonated iron ores such as siderite, magnesite, magnesite and magnesium siderite can be decomposed to produce magnetite after heating to a certain temperature (300-- 400 degrees Celsius) without air or by injecting a small amount of air. The chemical reaction is as follows:
3 FeCO3 -> Fe3O4 + 2 CO2 + CO
3 FeCO3 + CO -> 2 Fe3O4 + CO2
Oxidation roasting
Pyrite is oxidized in oxygen for a short time to oxidize to pyrite. If the roasting time is very long, the pyrite can continue to react into magnetite. The chemical reaction is as follows.
7 FeS2 + 6 CO -> Fe7S8 + 6 SO2
3 Fe7S8 + 38 O2 -> 7 Fe3O4 + 24 SO2
Redox roasting
Iron ore containing siderite, hematite or limonite, when the ratio of siderite to hematite is less than 1, the siderite is oxidized to hematite to a certain extent in the oxidizing atmosphere, and then it is reduced to magnetite together with the original hematite in the ore in the reducing atmosphere.
Reduction oxidation roasting
The magnetite produced by magnetization roasting of various iron ore can be oxidized into strong magnetic hematite when cooled to below 400 °C in an oxygen-free atmosphere and then in contact with the air. The chemical reaction is as follows:
3 Fe3O4 + O2 -> 6 Fe2O3
See also
Iron
Chemical reaction
Roasting (metallurgy)
Magnetic separation
Rotary kiln
References
External links
Metallurgical processes | Magnetization roasting technology | [
"Chemistry",
"Materials_science"
] | 1,729 | [
"Metallurgical processes",
"Metallurgy"
] |
77,327,179 | https://en.wikipedia.org/wiki/Pyknotic%20set | In mathematics, especially in topology, a pyknotic set is a sheaf of sets on the site of compact Hausdorff spaces (with some fixed Grothendieck universes). The notion was introduced by Barwick and Haine to provide a convenient setting for homological algebra. The term pyknotic comes from the Greek πυκνός, meaning dense, compact or thick. The notion can be compared to other approaches of introducing generalized spaces for the purpose of homological algebra such as Clausen and Scholze‘s condensed sets or Johnstone‘s topological topos.
Pyknotic sets form a coherent topos, while condensed sets do not. Comparing pyknotic sets with his approach with Clausen, Scholze writes:
References
Sources
External links
https://ncatlab.org/nlab/show/pyknotic+set
https://mathoverflow.net/questions/441610/properties-of-pyknotic-sets
https://mathoverflow.net/questions/356618/what-is-the-precise-relationship-between-pyknoticity-and-cohesiveness
https://golem.ph.utexas.edu/category/2020/03/pyknoticity_versus_cohesivenes.html
Topology | Pyknotic set | [
"Physics",
"Mathematics"
] | 286 | [
"Topology stubs",
"Topology",
"Space",
"Geometry",
"Spacetime"
] |
77,327,804 | https://en.wikipedia.org/wiki/NGC%207716 | NGC 7716 is an intermediate spiral galaxy located in the constellation Pisces. Its speed relative to the cosmic microwave background is 2,201 ± 26 km/s, which corresponds to a Hubble distance of 32.5 ± 2.3 Mpc (∼106 million ly). NGC 7716 was discovered by British astronomer John Herschel in 1831.
The luminosity class of NGC 7716 is II and it has a broad HI line. According to the SIMBAD database, NGC 7716 is a candidate galaxy for the active galaxy classification.
To date, twelve non-redshift measurements give a distance of 32.442 ± 5.854 Mpc (∼106 million ly), which is within the Hubble distance values.
NGC 7716 group
NGC 7716 is a member of a galaxy group of the same name. NGC 7716 group contains 5 members. The other galaxies in this group are NGC 7714, NGC 7715, UGC 12690 and UGC 12709.
See also
List of NGC objects (7001–7840)
External links
NGC 7716 at NASA/IPAC
NGC 7716 at SIMBAD
NGC 7716 at LEDA
References
7716
Discoveries by John Herschel
Unbarred spiral galaxies
Active galaxies
12702
71883
Pisces (constellation) | NGC 7716 | [
"Astronomy"
] | 270 | [
"Pisces (constellation)",
"Constellations"
] |
77,327,980 | https://en.wikipedia.org/wiki/Jordan%20Peccia | Jordan L. Peccia is an American engineer and Professor of Environmental Engineering at Yale University. He was born in Cut Bank, MT. Since 2005, Peccia has been a member of the Chemical and Environmental Engineering faculty at Yale University, where he holds the Thomas E. Golden endowed professorship., and serves as the department's Chair. He is an elected member of the Connecticut Academy of Science and Engineering. In 2023, Peccia was named Head of Yale’s Benjamin Franklin College.
Academic career
Peccia’s academic work integrates the problem-solving aspects of environmental engineering with microbial genetics and public health. Contributions include determining the infectious risks associated with the land application of sewage sludge, advancing exposure science on the beneficial health impacts of the indoor microbiome, and inventing DNA sequence-based tools for classifying the mold status of a building. Early in the COVID-19 pandemic, Peccia’s lab at Yale demonstrated how SARS-CoV-2 RNA concentrations in domestic wastewater could be a leading indicator (over clinical case monitoring) of COVID-19 outbreaks. Peccia is a member of a group of international scientists that advocated for recognizing the airborne route of transmission during the COVID-19 pandemic. He is the founding chair of the Gordon Research Conference of the Microbiology of the Built Environment
Family
His brother is James D. Peccia III, Major General (retired), United States Air Force.
References
External links
Benjamin Franklin College, Yale University
Chemical and Environmental Engineering, Yale University
Peccia environmental biotechnology lab website, Yale University
People from Cut Bank, Montana
American environmental scientists
Public health researchers
Year of birth missing (living people)
Living people
Environmental engineers
University of Colorado Boulder alumni
Montana State University alumni
Yale University faculty
21st-century American engineers | Jordan Peccia | [
"Environmental_science"
] | 371 | [
"American environmental scientists",
"Environmental scientists"
] |
77,328,447 | https://en.wikipedia.org/wiki/Cree%20Hunters%20Economic%20Security%20Board | The Cree Hunters Economic Security Board (CHESB) is a bipartisan organization co-directed by the Quebec Government and the Cree Nation Government having as its primary objective the perpetuation of the traditional Cree lifestyle, based on wildlife harvesting activities, by offering guaranteed income to Cree hunters and trappers in Quebec. The board runs the Economic Security Program for Cree Hunters.
It takes its origin from the James Bay and Northern Quebec Agreement (JBNQA), signed on November 11th, 1975, and was put in place in November 1976. In 2022, the program which the board oversees had a budget of around 30 million dollars. The program is available to all Cree beneficiaries of the JBNQA. It covers harvesting activities such as hunting and trapping, as well as perimeter activities such as fabrication and fixing of supplies and tools, land preparation, wildlife management, transportation, and creation and commercialization of products and crafts.
Originally named "Cree Hunters and Trappers Income Security Board", its name was changed to its current one in 2020. Its head office is in Quebec City.
The board
The board was created from section 30 of JBNQA. The "Act respecting the Cree hunters economic security board" is the law which regulates it. It has six members, three of whom are appointed by the Quebec government and three by the Cree Nation Government. As of 2021-2022, the board employs 16 people, 11 of whom serve within the Cree communities, the five remaining work at the head office in Quebec City. The following ten communities are served by the program: Chisasibi, Eastmain, Mistissini, Nemaska, Oujé-Bougoumou, Waskaganish, Waswanipi, Wemindji, Whapmagoostui and Washaw-Sibi.
The program
The mission of the board is to run the economic security program for Cree hunters, and in so encourage the conservation and perpetuation of the traditional lifestyle by providing a financial support to beneficiaries who engage in the lifestyle. The board aims to ensure these activities remain possible despite changes in the social, economic and natural environment of those who practice harvesting activities.
The program provides income and other benefits to Crees who choose harvesting activities (hunting, trapping and fishing) as a way of life. Benefits are calculated according to, among other things, the number of days spent practicing eligible activities, and other sources of income.
Eligible activities
Eligible activities include harvesting activities such as hunting, trapping, and fishing (commercial fishing is excluded), but also secondary activities like the maintenance and fabrication of harvesting supplies and equipment, gathering of wild plants, wildlife and trapline management, transportation to and from harvesting sites and camps, and fabrication, processing and marketing of crafts and products of harvesting.
References
External links
Cree Hunters Economic Security Board
James Bay and Northern Quebec Agreement
Eeyou Istchee (territory)
Cree
James Bay Project
Quebec government departments and agencies | Cree Hunters Economic Security Board | [
"Engineering"
] | 593 | [
"James Bay Project",
"Macro-engineering"
] |
77,328,555 | https://en.wikipedia.org/wiki/Andrew%20Pohorille | Andrzej (Andrew) Pohorille (May 14, 1949 – January 6, 2024) was a Polish-American astrobiologist, biophysicist, and quantum chemist who worked mostly at the NASA-Ames Research Center and University of California, San Francisco. He was a leading scientist on the origin of life and biosignature detection at NASA. His work proposed that proteins may have been the first molecules to support life, challenging RNA-first theories of abiogenesis.
Education and career
Pohorille was the only child of Eugenia Gartenberg, a teacher, and Maksynilian Pohorille, a professor of economics at SGH Warsaw School of Economics. He moved to the US at the age of six and later studied physics at the University of Warsaw, where he eventually obtained his Ph.D. in theoretical physics and structural biology under the supervision of David Shugar. He went on to conduct postdoctoral research at the Institut de biologie physico-chimique in Paris, where he worked in the group of Bernard Pullman. He became an assistant professor at the University of California, Berkeley in 1988, where he worked until 1992. He moved to the University of California, San Francisco in the same year as a professor at the Department of Pharmaceutical Chemistry.
In 1996, Pohorille joined the NASA Ames Research Center, where he was a principal investigator and head of the NASA Center for Computational Astrobiology. He maintained his position at University of California, San Francisco. At NASA, Pohorille conceived and led the development of the Life Detection Knowledge Base (LDKB), a community web tool that assists the detection of the evidence of life beyond Earth. He also was a leading figure in the establishment of the NASA Center for Life Detection, where he later became a co-director.
In 2002, Pohorille received the NASA Exceptional Scientific Achievement Medal. In 2010, he received the H. Julian Allen Award. In 2005, he became the Distinguished Lecturer at the Centre for Mathematical Modeling and the National Space Research Centre in the U.K.. In 2008, he was the Maxwell Colloquium speaker at the University of Edinburgh.
Personal life
Pohorille's parents were the only members of their families who survived the Holocaust. Pohorille was married to Joanna Sokołowska, whom he met at a conference and is also his working partner.
See also
Mary Voytek
Center for Life Detection
References
1949 births
2024 deaths
University of Warsaw alumni
University of California, Berkeley faculty
University of California, San Francisco faculty
NASA people
American astrobiologists
American biophysicists
People from Szczecin
American people of Polish-Jewish descent
Polish physicists
Computational chemists | Andrew Pohorille | [
"Chemistry"
] | 552 | [
"Computational chemistry",
"Theoretical chemists",
"Computational chemists"
] |
77,330,112 | https://en.wikipedia.org/wiki/List%20of%20grass%20jelly%20plants | Grass jelly is a gelatinous dessert that is usually made from a plant in the mint family called Platostoma palustre. It and similar desserts can be made from other grass jelly plants. Some are also used for making beverages.
There are two main types, green grass jelly and black grass jelly. Green grass jelly plants include Premna trichostoma and Cyclea barbata, while black (also called ) includes species like P. palustre
In Indonesian, grass jelly plants are called . In Javanese, these plants are called , , or and in Sundanese they are called or .
There are other plants that could possibly be used for making grass jelly but are not currently known to be used as such.
Grass jelly plants
Notes
See also
Aiyu jelly
Bingfen
Climbing fig tofu
O-aew
References
Chinese desserts
Chinese cuisine-related lists
Dessert-related lists
Indonesian cuisine-related lists
Jams and jellies
Lists of plants
Vietnamese cuisine-related lists | List of grass jelly plants | [
"Biology"
] | 201 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
69,815,794 | https://en.wikipedia.org/wiki/Elizabeth%20Opila | Elizabeth Jane Opila is an American materials scientist who is the Rolls-Royce Commonwealth Professor of Engineering at the University of Virginia. Her research considers the development of materials for extreme environments. She was elected Fellow of the Electrochemical Society in 2013 and the American Ceramic Society in 2014.
Early life and education
Opila earned her bachelor's degree at the University of Illinois Urbana-Champaign, where she studied ceramic engineering. She moved to the University of California, Berkeley for graduate studies. Her master's research considered the surface diffusion of high temperature vapors in porous materials. She joined Massachusetts Institute of Technology as a doctoral researcher. Her doctoral research considered the chemistry of La2-xSrxCuO4, a high temperature superconductor. She joined the Glenn Research Center in 1991, where she worked on the shuttle program.
Research and career
In 2010, Opila joined the University of Virginia as a professor of Materials Science. She leads the Rolls-Royce University Technology Center for Advanced Materials Systems. Opila studies ultra-high temperature ceramics, which are used in ball bearings, armor and aerospace. She is particularly interested in the development of materials that facilitate hypersonic travel. To investigate these materials, she creates lab-based experiments that can characterize materials properties at ultra high temperatures, flow rates and in the presence of reactive gases. Characterization involves spectroscopy, microscopy and chemical analysis (e.g. thermochemical properties and changes in weight).
Opila has worked on strategies to increase the temperature tolerances and efficiencies of turbine engine materials. This has involved holding contracts with NASA and the United States Department of Defense. Environmental barrier coatings can be used to protect ceramics from particulate matter and water vapor, but can corrode in sand, dust and volcanic ash. Opila developed coatings that allow niobium alloys to operature at 1,800 °C. These coatings serve to protect alloys from oxidising. The coatings are made of rare-earth oxides, specifically, high entropy rare earth oxides (HERO). HERO coatings protect the alloys from oxidizing and limit the build up of stress. Stress-build up is minimized by matching the thermal expansion of the coating with the underlying alloys, such that when they expand and contract during temperature changes they do so in the same directions/at the same rate. She combines computation modelling, artificial intelligence and quantum mechanics to identify the best candidates for HERO coatings.
Opila pioneered an undergraduate course on advanced ceramics in 2020.
Selected publications
Awards and honors
2013 Elected Fellow of the Electrochemical Society
2014 Elected Fellow of the American Ceramic Society
2020 German Research Foundation Mercatur Fellow
2021 American Ceramic Society Arthur L. Friedberg Award
References
Living people
University of Illinois Urbana-Champaign alumni
University of California, Berkeley alumni
Massachusetts Institute of Technology alumni
University of Virginia faculty
Materials scientists and engineers
American scientists
Year of birth missing (living people) | Elizabeth Opila | [
"Materials_science",
"Engineering"
] | 590 | [
"Materials scientists and engineers",
"Materials science"
] |
69,816,008 | https://en.wikipedia.org/wiki/1990%20ARCO%20explosion | An explosion at the ARCO Chemical (ACC) Channelview, Texas petrochemical plant killed 17 people and injured five others on July 5, 1990. It was one of the deadliest industrial disasters in the history of the Greater Houston area.
The land along the Houston Ship Channel is a heavily industrialized area, with numerous oil refineries. In the late 1980s and early 1990s, several large industrial disasters occurred in the area, with the largest being the Phillips disaster of 1989, a refinery explosion that resulted in 23 deaths and over 100 injuries. In the community of Channelview, ACC operated a petrochemical plant that was the world's largest producer of the fuel additive methyl tert-butyl ether. On July 5, 1990, employees at the plant were working on restarting a compressor for a wastewater storage tank at the facility. The tank held wastewater that contained hydrocarbons until it could be deposited in a disposal well. Because the hydrocarbons in the tank could vaporize, the tank had an oxygen analyzer that kept track of the oxygen concentration in the tank and had a nitrogen sweep system to keep the gas inert. However, unbeknownst to the employees, the oxygen analyzer had malfunctioned and as a result, the oxygen level in the tank was at a dangerous level. While restarting the compressor, the gas ignited and caused a large explosion. The explosion completely destroyed the tank and some of the surrounding facility infrastructure, affecting an area the size of a city block.
Following the accident, the Occupational Safety and Health Administration (OSHA) fined ACC about $3.48 million for over 300 violations of the Occupational Safety and Health Act, the largest OSHA fine at the time. Additionally, the company agreed to safety changes at its other three plants in the United States. Damages were estimated to total $100 million; however, ACC spent only $36 million in repairs and upgrades at the Channelview plant including $20 million on safety redundancies.
Background
Previous industrial accidents in the area
The Houston Ship Channel is a roughly long waterway that links the Texas city of Houston to Galveston Bay and, ultimately, the Gulf of Mexico. The channel makes up part of the port of Houston, which in 1990 was the third-largest port in the United States. The land on either side of the channel is a heavily industrialized area, with approximately 150 industries in operation there in 1990, including numerous oil refineries. A 1990 article in the Los Angeles Times referred to the area as having "the largest complex of petrochemical plants in the nation", and during the late 1980s and early 1990s, there were several large-scale explosions or disasters at these plants. In October 1989, a refinery in Pasadena, Texas, that was operated by the Phillips Petroleum Company exploded in a disaster that killed 23 people and injured over 100, and two more explosions the following year at different refineries injured a further seven people. These incidents prompted an April 1990 report from Secretary of Labor Elizabeth Dole to President George H. W. Bush that called on the petrochemical industry to develop stronger safety plans to prevent future accidents.
Arco Chemical Channelview plant
In the Ship Channel community of Channelview, Texas, located several miles east of downtown Houston, chemical and plastics company ACC operated a large petrochemical plant. The plant had been in operation since 1977 and had been acquired by ARCO in 1980. The plant primarily produced petroleum additives and in 1990 was the largest producer of the fuel additive methyl tert-butyl ether (MTBE) in the world, producing between and daily. This resulted in an annual production of approximately of MTBE, equivalent to approximately 25 percent of the United States's total MTBE production. Additionally, the plant annually produced about of propylene oxide and of styrene monomer. The plant around this time employed about 350 ACC employees, in addition to about 150 contractors from Austin Industrial, Inc., a Houston-based contracting firm, and had a total annual payroll of about $20 million. From taking over the plant in 1980 until 1990, ARCO had been cited twice by the Occupational Safety and Health Administration (OSHA) for minor violations of the Occupational Safety and Health Act.
On the northwestern edge of the plant, in a remote utility area, was a storage tank, measuring about tall and in diameter, that temporarily stored wastewater from the plant's propylene oxide and styrene monomer operations. After treatment, this liquid was transferred to an on-site disposal well. The wastewater, which was held in the tank at atmospheric pressure, usually contained some hydrocarbon liquids that would result in hydrocarbon vapor and oxygen building up in the vapor space of the tank. To prevent these vapor levels from reaching dangerous levels, the tank had an oxygen analyzer that provided a continuous readout of the oxygen level in the tank, and excessive oxygen and hydrocarbon vapor could be purged through a nitrogen sweep system. A compressor would move this vapor to a pressurized tank where it would be scrubbed before being vented to the atmosphere. Throughout early 1990, this compressor required additional maintenance, and it had been out of service for 41 percent of the year. In late June 1990, this compressor stopped working, and ARCO removed the piece of equipment and began venting the vapor from the tank to the open atmosphere, which had been the standard method of vapor disposal practiced at the plant before scrubbing was introduced as part of an environmental upgrade to the facility. On July 4, the nitrogen sweeping system was turned off to allow workers to modify some piping and instrumentation, as well as general cleaning of the tank, before restarting the compressor. The system had been turned off only after the oxygen analyzer showed safe levels of oxygen within the tank. The following day, July 5, the compressor was to be restarted. At the time, there were several dozen people working the night shift at the facility, with five working in the immediate area of the tank. However, the number of people in the area was larger than usual due to the cleaning of the tanks.
Explosion
At 11:21 p.m. CDT, an explosion occurred when the compressor for the wastewater tank was being restarted. The explosion resulted in a large flame that rose at least over the Houston Ship Channel, resulting in large plumes of black smoke. The blast was felt by people as far as away, and windows in some nearby homes were reportedly broken from the pressure wave. At the facility, an area of roughly one city block was severely damaged by the explosion. The wastewater storage tank was completely destroyed, with an article in the Los Angeles Times describing it as having been "flattened like a soft drink can crushed in a vise". The explosion within the tank had been so powerful that the lid of the tank had been blown off and landed in a parking lot about away. Additionally, another nearby tank was blown into a pipe rack. Along with the two tanks and the main pipe rack, the explosion also seriously damaged a cogeneration facility and two cooling towers. However, the blast did not affect the MTBE facilities at the plant.
Emergency response
In the immediate aftermath, authorities described the incident as relatively minor, with no reports of any injuries. Shortly after the blast, the facility's fire brigade began putting out the fires that had resulted from the explosion. They would be the main firefighting force that handled the fires, although additional help would be provided by the hazardous materials units from the Channel Industries Mutual Aid, Merichem, and the Shell Oil Refinery. Most of the fires had been put out by 4 a.m. the next morning, with smaller fires completely put out by 5 a.m. According to company officials, the explosion did not result in any leakage of hazardous materials, and no area evacuation was issued, although traffic was rerouted away from the facility. After the fires were put out, the plant's main operations were shut down, including the MTBE operations. The plant was expected to be shut down for several months as it underwent repairs. The shutdown affected approximately 15 percent of the total production of styrene in the United States.
Members of the Harris County fire marshal's and medical examiner's offices arrived on the scene following the explosion. While initial reports from company authorities had stated that there had been no injuries, there had in fact been several injuries and multiple deaths from the disaster. The fire marshal's office assisted in body recovery, and by 11 a.m. the next morning, 14 bodies had been found, with two people believed to have been in the plant at the time unaccounted for. Through the day, this number would rise to 15 dead and one unaccounted for. By July 6, the final count had 17 people killed and five injured. Of the dead, five were Arco Chemical employees and eleven were Austin Industrial employees. Additionally, a truck driver was found dead in the cabin of their vacuum truck. He was an employee for Waste Processing, Inc., which had been contracted to help with maintenance work. Some of the injured were hospitalized at the nearby San Jacinto Methodist Hospital in Baytown, Texas. Speaking about the size of the tragedy, ACC Americas President Jack Johnson said, "In my 32 years I can't remember a single incident of this magnitude where we had multiple loss of life".
Aftermath
Investigation and cause of the accident
On the morning of July 6, Gerard F. Scannell, an Assistant Secretary in the United States Department of Labor and head of OSHA, arrived at the scene, saying he would ensure "that all necessary resources of the Labor Department and OSHA are made available for a complete and timely investigation of this workplace tragedy". Specifically, Scannell stated that OSHA would be reviewing work orders and interviewing people from the plant to determine if the maintenance work that was being conducted at the wastewater storage tank had contributed to the explosion. At the time, authorities were not completely sure if the compressor had caused the explosion. OSHA concluded their initial review of the site within a week. By January 1991, according to an article in the Oil & Gas Journal, investigators were "95% sure" regarding the cause and timeline of events regarding the explosion. According to OSHA investigators, the oxygen analyzer in the wastewater tank had malfunctioned on June 15, 1990, resulting in a reduction in the nitrogen purging and a steady buildup of oxygen in the tank that reached dangerous levels. This was further intensified during the maintenance work performed on July 4 and 5, when the nitrogen system was temporarily shut down. As a result, energy from some normal operation around the tank (such as the compressor restarting) provided enough energy to ignite the vapor and cause the explosion.
Use of contracted employees
Several contemporary sources also noted the use of contracted labor in discussions of the explosion. In a 1990 article of The New York Times, journalist Roberto Suro noted that in the April 1990 report that Labor Secretary Dole had submitted concerning petrochemical plant accidents there were, among other things, recommendations that contracted employees at these facilities be given special safety training. The Los Angeles Times similarly cited a report by the John Gray Institute of Lamar University in Beaumont, Texas, that stated that contract workers received less safety training and were less knowledgeable of workplace hazards than their company employee counterparts. According to the report, due to economic and time constraints, "safety was frequently cited as a secondary consideration among short-term contractors". The subject was also a point of discussion in a July 23, 1990, hearing before the United States House Committee on Government Operations on chemical accidents, Representative Tom Lantos stated that, as with some previous incidents, "the contract work force again figures prominently", noting that while 75 percent of the facility's employees were ACC employees, two-thirds of the people killed were contracted workers. The Oil, Chemical and Atomic Workers International Union (OCAW, a labor union representing petrochemical workers) similarly criticized the use of contracted labor at the facility, with Secretary-Treasurer Tony Mazzocchi saying, "There is a direct association between the lack of preventive maintenance, the substitution of contract labor for skilled, permanent union labor and this accident. The contractors were probably working more than 16 hours straight when [the tank] exploded." Similarly, in a July 8 article by United Press International, the wife of one of the contracted workers killed in the explosion said he had been working 16-hour shifts and had worked 86 hours the week before the incident. Some of the contracted workers who were working on the tank had been on the job since 7 a.m. and had been working until the explosion, past the legally-mandated quitting time of 11 p.m. The president of the OCAW local union in Houston made comments similarly linking the explosion to the use of contracted labor. However, a vice president of ARCO dismissed the connection, saying, "The focus on contract workers is unfortunate. It doesn't address the problem." At the time of the accident, approximately half of the petrochemical workers in the United States were non-union contract workers.
Legal settlements and changes from the company
U.S. and Texas officials opted not to criminally prosecute ACC for the deaths. However, on January 3, 1991, ACC agreed to pay $3,481,300 in fines levied by OSHA for violations of the Occupational Safety and Health Act no later than January 10. OSHA had fined the company $10,000 for each of the 347 "willful" violations (wherein the company intentionally disregarded or was indifferent to the requirements in the Occupational Safety and Health Act) and a further $11,300 for 15 "serious" violations (wherein the company operated while knowing of a serious probability of an accident that could cause injuries or death). At the time, it was the largest monetary settlement in OSHA history. Other terms of the agreement stipulated that ACC would organize a "process hazard analysis staff" for each of its four U.S. facilities (including the Channelview facility) within 30 days, which would then conduct process hazard analyses and report their findings to their respective OSHA regional offices within 270 days. Within 30 days of these reports, the management of each plant would have to provide written statements and would then have no more than one year to implement the changes recommended by these teams. ARCO, in agreeing to the settlement with OSHA, stated that it did not affirm the accuracy of OSHA's investigation and conclusions regarding the conduct and operations at the plant. However, according to Arco Chemical Americas President Johnson, instead of disputing some of OSHA's conclusions, "we decided it served everyone better if we focused on improving safety of our operations". In addition to the OSHA fines, the company faced lawsuits from the families of several of the deceased workers. In total, damages from the explosion were approximately $100 million.
In addition to the fines and mandated changes, ACC agreed to revamp safety measures regarding safety training and management at all four facilities in the United States. Infrastructure-wise, ACC spent $36 million between July 1990 and January 1991 in repairs and upgrades to the wastewater facilities at the Channelview plant. Of that amount, $20 million was spent on adding system safety redundancies. For example, the upgrades resulted in a change in the number of wastewater storage tanks increasing from three to eight, an increase in the number of oxygen analyzers from one to sixteen, and the installation of a backup nitrogen supply system that sweeps the tanks on a continuous basis.
Later history
In a 2001 book, anthropologist and professor Kim Fortun discussed the explosion and compared the disaster to the Bhopal disaster, citing similarities between the role that maintenance neglect and inexperienced workers played in the two incidents. In 2002, the U.S. Chemical Safety and Hazard Investigation Board (an independent federal agency that investigates industrial accidents) completed a two-year study on serious chemical accidents that occurred between 1980 and 2000, specifically highlighting the 1990 ARCO explosion as one of the worst in that time period. The board convened in September of that year in Houston, in part because the Houston area had been home to large-scale disasters like the one in 1990. Since then, the next biggest industrial disaster to occur in the Greater Houston area was the 2005 Texas City refinery explosion, which killed 15 people and injured 180.
See also
List of disasters in the United States by death toll
List of explosions
List of industrial disasters
Notes
References
Sources
Further reading
External links
1990 disasters in the United States
1990 in Texas
1990 industrial disasters
ARCO
Chemical plant explosions
Explosions in 1990
Fires in Texas
Greater Houston
Harris County, Texas
Industrial fires and explosions in the United States
July 1990 events in the United States
Explosions in Texas | 1990 ARCO explosion | [
"Chemistry"
] | 3,410 | [
"Chemical plant explosions",
"Explosions"
] |
69,816,725 | https://en.wikipedia.org/wiki/Typhloesus | Typhloesus wellsi is an extinct species of enigmatic bilaterian animals from the Bear Gulch Limestone. It was once thought to be the first body fossil of a conodont, based on what turned out to be its gut contents; it is now thought to exhibit a radula, which would make it a mollusc, although different types of animal have independently evolved radula-like features. Mark Purnell, of the Centre for Palaeobiology at the University of Leicester, said that it was not definitively known "what this weird thing is".
Discovery
Typhloesus was first described back in 1973 from Carboniferous rocks in Montana. The animal was then jokingly referred to as the ‘alien goldfish’ by subsequent studies. Because of its highly enigmatic nature, this organism was only mentioned briefly in several papers. It was then thought to have been the first known body fossil of a conodont, which are a primitive group of jawless agnathan fish distantly related to lampreys and hagfish. This was based on the presence of "conodont elements", which are the small comb-like teeth of those animals. The teeth however were actually located in the gut contents of the Typhloesus, meaning that while it wasn't a conodont, they were a part of its diet. The animals taxonomy would be shrouded in mystery for over 30 years until in September 2022, when a new paper published revealed several potential mollusk-like features of the animal.
Description
It has a fusiform (spindle-shaped) body, with a maximum length of 90 mm. At the posterior or backside of the animal is a caudal fin, which was supported by two sets of orthogonal fin rays. The exterior lacks any other organs. The internal anatomy consists of a foregut and a midgut. The gut lacks a midsection and an anus. Beneath the midgut is a disc shaped organ, tentatively called a ferrodiscus; the purpose of this organ is unknown, however it has a high concentration of iron.
Paleoecology
It might have been both a predator and a scavenger, as its fossils sometimes contain conodont teeth and worm teeth located in the midgut of the animal.
See also
Tullimonstrum, another enigmatic animal from the upper Carboniferous of Illinois.
References
Enigmatic protostome taxa
Controversial taxa | Typhloesus | [
"Biology"
] | 499 | [
"Biological hypotheses",
"Controversial taxa"
] |
69,816,853 | https://en.wikipedia.org/wiki/CoRoT-24c | CoRoT-24c is a transiting exoplanet found by the CoRoT space telescope in 2011 and announced in 2014. Along with CoRoT-24b, it is one of two exoplanets orbiting CoRoT-24, making it the first multiple transiting system detected by the telescope. It is a hot Neptune orbiting at a distance of 0.098 AU from its host star.
References
Transiting exoplanets
Exoplanets discovered in 2011
24b
Hot Neptunes | CoRoT-24c | [
"Astronomy"
] | 104 | [
"Outer space stubs",
"Outer space",
"Astronomy stubs"
] |
69,817,181 | https://en.wikipedia.org/wiki/Ganoderma%20microsporum | Ganoderma microsporum is a species of Ganoderma mushroom native to Taiwan that grows on willow trees.
Description
Ganoderma microsporum has a relatively short or obscure stem that appears bronze or dark purple. The cap is shelf like or unevenly shaped and has a glazed appearance.
The spores measure 6–8.5 by 4.5–5 μm, smaller than the spores of all other known types of Ganoderma.
Taxonomy
The species was first discovered in Taipei, Taiwan by R.-S. Hseu in 1982, and published in the scientific journal Mycotaxon in 1989.
The specific epithet microsporum refers to the relatively small size of its spores.
Research
Compounds discovered in Ganoderma include polysaccharides, triterpenoids, nucleic acids and fungal immunomodulatory proteins or FIPs.
According to the NIH PubMed database on the physiological activities of G. microsporum, primarily from the FIP found in G. microsporum (FIP-gmi or GMI), currently known physiological activities include effects on the central nervous system and the respiratory system.
References
microsporum
Fungi of Taiwan
Fungi described in 1989
Fungus species | Ganoderma microsporum | [
"Biology"
] | 248 | [
"Fungi",
"Fungus species"
] |
69,817,701 | https://en.wikipedia.org/wiki/NGC%20959 | NGC 959 is a spiral galaxy in the northern constellation of Triangulum. It was discovered on 9 November 1876 by French astronomer Édouard Stephan. This galaxy is located at a distance of 36 million light years and is receding with a heliocentric radial velocity of 596 km/s. It is a member of the NGC 1023 Group of galaxies.
The morphological class of this galaxy is Sdm:, indicating it is a spiral (S) with disorganized, irregular arms and no central bulge (dm). The ':' suffix indicates some uncertainty about the classification. It has a visual magnitude of 12.4. The galactic plane is inclined at an angle of 50° to the plane of the sky, giving it an elliptical profile with the major axis aligned along a position angle of 65°. The size of the D25 ellipse (where the brightness of the galaxy drops to magnitude 25) is arcminutes.
When images of NGC 959 are corrected for the effects of extinction from dust, a central bar feature can be discerned. The galaxy then shows a non-negligible bulge or central condensation, and may instead have a morphological type of SBcd. It displays a cuspy central density profile and bulge-like monotonic decrease in ellipticity toward the core.
References
External links
Triangulum
Spiral galaxies
Dwarf spiral galaxies
Magellanic spiral galaxies
0959
02002
009665
Astronomical objects discovered in 1876
Discoveries by Édouard Stephan | NGC 959 | [
"Astronomy"
] | 306 | [
"Triangulum",
"Constellations"
] |
69,817,964 | https://en.wikipedia.org/wiki/Marta%20Bunster | Marta Cecilia del Carmen Bunster Balocchi is a Chilean scientist, most noted for her work in the fields of biochemistry, biophysics and crystallography. She is also known as one of the main promoters of bioinformatics in her country.
Biography
She began studying biochemistry in 1969 at the University of Concepción, where she spent most of her academic and professional career. She obtained a biochemistry diploma in 1974 for her work about X-ray diffraction on synthetic polypeptides. After obtaining her degree, she moved to Santiago, where she worked at the laboratory of Osvaldo Cori and Aida Traverso, from the Faculty of Chemical Sciences of the University of Chile. There, she collaborated in the investigation of the kinetic properties of a potato apyrase. After 4 months, she returned to Concepción and entered to the Doctor of Sciences Program, with a major in chemistry. In 1975, she was conferred an academic position as instructor of biophysics for biochemistry teachers at the Department of Physiology of the Institute of Medical Biological Sciences, precursor of the current Biological Sciences Faculty of the University of Concepción. Bunster obtained her doctoral degree in 1981 for her study on synthetic polymers of pharmacological application, at the University of Concepción and the laboratory of George B. Butler at the University of Florida. That year, she returned to Concepción once more and met doctor Hilda Cid, a renowned scientist in the fields of physics and crystallography, who had returned from Sweden after being politically persecuted. During those years, Cid specialized in crystallographic techniques at Uppsala University, which provided her the necessary equipment for her studies once she returned to Chile. Together, they established the Molecular Biophysics Laboratory of the Faculty of Biological Sciences and Natural Resources, now the Faculty of Biological Sciences, and started studying new methods for proteins structures and folding prediction. Among their first research was the development of the secondary structures prediction method by means of hydrophobicity profiles, which was greatly welcomed in the region due to its high reliability and low cost, being one of the bases of some of the modern techniques. In the mid 90's, and coinciding with Cid's retirement, Bunster investigated phycobilisomes, a fluorescent, macromolecular-light harvesting system present primarily in cyanobacteria and red algae. This research led to the development of spectroscopic techniques and its application. It allowed a greater understanding of conformational changes phenomena from a physical perspective.
Legacy
In the 2000s, driven by the boom of bioinformatics, Bunster dedicated her efforts to consolidating international cooperation in this area, forming in 2002 the Iberoamerican Network for Bioinformatics, later renamed as Iberoamerican Society for Bioinformatics (SoIBio), institution in which she assumed a directive role as Secretary on its first executive board, and on which she remains active to this day.
She was part of the Biological Sciences Doctoral Program since its creation, as well as one of the founding members and Director of the Master in Biochemistry and Bioinformatics and the Director of the Biochemistry and Molecular Biology Department from 2014 until her retirement in 2020.
Organizational activity
Bunster has been part of numerous scientific organizations during her career, both in Chile and abroad. Some of them include: Chilean Chemical Society, Chilean Biology Society, Society of Biochemistry and Molecular Biology of Chile, Biophysical Society, International Society for Computational Biology (ISCB), and the Latin American Cristallographic Association (LACA).
Featured publications
Cid, H., Bunster, M., Arriagada, E., & Campos, M. (1982). Prediction of secondary structure of proteins by means of hydrophobicity profiles. FEBS Letters, 150(1), 247–254. https://doi.org/10.1016/0014-5793(82)81344-6.
Cid, H., Vargas, V., Bunster, M., & Bustos, S. (1986). Secondary structure prediction of human salivary proline-rich proteins. FEBS letters, 198(1), 140–144. https://doi.org/10.1016/0014-5793(86)81200-5.
Cid, H., Bunster, M., Canales, M., & Gazitúa, F. (1992). Hydrophobicity and structural classes in proteins. Protein engineering, 5(5), 373–375. https://doi.org/10.1093/protein/5.5.373.
Contreras-Martel, C., Martinez-Oyanedel, J., Bunster, M., Legrand, P., Piras, C., Vernede, X., & Fontecilla-Camps, J. C. (2001). Crystallization and 2.2 Å resolution structure of R-phycoerythrin from Gracilaria chilensis: a case of perfect hemihedral twinning. Acta crystallographica. Section D, Biological crystallography, 57(Pt 1), 52–60. https://doi.org/10.1107/s0907444900015274.
Godoy, F. A., Bunster, M., Matus, V., Aranda, C., González, B., & Martínez, M. A. (2003). Poly-beta-hydroxyalkanoates consumption during degradation of 2,4,6-trichlorophenol by Sphingopyxis chilensis S37. Letters in applied microbiology, 36(5), 315–320. https://doi.org/10.1046/j.1472-765x.2003.01315.x.
Martínez-Oyanedel, J., Contreras-Martel, C., Bruna, C., & Bunster, M. (2004). Structural-functional analysis of the oligomeric protein R-phycoerythrin. Biological Research, 37(4). https://doi.org/10.4067/s0716-97602004000500003.
Tobella, L. M., Bunster, M., Pooley, A., Becerra, J., Godoy, F., & Martínez, M. A. (2005). Biosynthesis of poly-beta-hydroxyalkanoates by Sphingopyxis chilensis S37 and Wautersia sp. PZK cultured in cellulose pulp mill effluents containing 2,4,6-trichlorophenol. Journal of industrial microbiology & biotechnology, 32(9), 397–401. https://doi.org/10.1007/s10295-005-0011-1.
Contreras-Martel, C., Matamala, A., Bruna, C., Poo-Caamaño, G., Almonacid, D., Figueroa, M., Martínez-Oyanedel, J., & Bunster, M. (2007). The structure at 2 Å resolution of Phycocyanin from Gracilaria chilensis and the energy transfer network in a PC-PC complex. Biophysical chemistry, 125(2-3), 388–396. https://doi.org/10.1016/j.bpc.2006.09.014.
Figueroa, M., Hinrichs, M. V., Bunster, M., Babbitt, P., Martinez-Oyanedel, J., & Olate, J. (2009). Biophysical studies support a predicted superhelical structure with armadillo repeats for Ric-8. Protein science, 18(6), 1139–1145. https://doi.org/10.1002/pro.124.
Burgos, C. F., Castro, P. A., Mariqueo, T., Bunster, M., Guzmán, L., & Aguayo, L. G. (2015). Evidence for α-helices in the large intracellular domain mediating modulation of the α1-glycine receptor by ethanol and Gβγ. The Journal of pharmacology and experimental therapeutics, 352(1), 148–155. https://doi.org/10.1124/jpet.114.217976.
Sivakumar, R., Manivel, A., Meléndrez, M., Martínez-Oyanedel, J., Bunster, M., Vergara, C., & Manidurai, P. (2015). Novel heteroleptic ruthenium sensitizers containing carbazole linked 4,5-diazafluorene ligand for dye sensitized solar cells. Polyhedron, 87, 135–140. https://doi.org/10.1016/j.poly.2014.11.008.
Vásquez-Suárez, A., Lobos-González, F., Cronshaw, A., Sepúlveda-Ugarte, J., Figueroa, M., Dagnino-Leone, J., Bunster, M., & Martínez-Oyanedel, J. (2018). The γ33 subunit of R-phycoerythrin from Gracilaria chilensis has a typical double linked phycourobilin similar to β subunit. PLOS ONE, 13(4), e0195656. https://doi.org/10.1371/journal.pone.0195656.
References
Chilean biologists
Chilean biochemists
Biophysicists
Bioinformaticians
Crystallographers
University of Concepción alumni
Academic staff of the University of Concepción
Year of birth missing (living people)
Living people
Chilean women scientists
Women biochemists
Women biophysicists
Women bioinformaticians | Marta Bunster | [
"Chemistry",
"Materials_science",
"Biology"
] | 2,150 | [
"Bioinformatics",
"Crystallography",
"Bioinformaticians",
"Women biochemists",
"Crystallographers",
"Biochemists"
] |
69,818,030 | https://en.wikipedia.org/wiki/NGC%20549 | NGC 549 is a barred spiral galaxy in the southern constellation Sculptor. It was discovered by British astronomer John Frederick William Herschel on November 29, 1837.
References
Astronomical objects discovered in 1837
Barred spiral galaxies
Discoveries by John Herschel
549
Sculptor (constellation) | NGC 549 | [
"Astronomy"
] | 53 | [
"Constellations",
"Sculptor (constellation)"
] |
69,818,122 | https://en.wikipedia.org/wiki/Asterina%20stipitipodia | Asterina stipitipodia is a species of fungus in the family Asterinaceae, first described by Marie Leonore Farr in 1987. It was originally found on the leaves of Dilleniaceae species in Brazil, South America,
References
Dothideomycetes
Taxa described in 1987
Taxa named by Marie Leonore Farr
Fungus species | Asterina stipitipodia | [
"Biology"
] | 72 | [
"Fungi",
"Fungus species"
] |
69,818,125 | https://en.wikipedia.org/wiki/Mycena%20roseoflava | Mycena roseoflava is a species of agaric mushroom in the family Mycenaceae. It was first discovered in 1964 by New Zealand mycologist Greta Stevenson. It is a wood-inhabiting mushroom native to New Zealand.
The small fungus is saprotrophic, meaning it gains nutrients from decaying organic matter and appears on stressed or dying plants, often found on rotting wood and twigs. As matter decomposes within a medium in which a saprotroph is residing, the saprotroph breaks such matter down into its composites.
M. roseoflava has white spores with small white caps, normally standing at a height of 5-10 millimeters and an equal width. It is most active in the autumn season and is not considered edible. The stem relatively short is often attached to the side of wood, usually with a slightly swollen stem base. It is rare to see in Victoria, where it has only found only in wetter forests and rainforests, but is somewhat common in Tasmania.
In the first descriptions of the mushroom, Stevenson noted the caps were "pink fading yellowish, hemispherical with a shallow central umbilicus." The texture of the caps were smooth to minutely floccose. The gills were described as adnate to slightly concurrent. The spores were observed to be globose, amyloid, and thin-walled.
In 2021, the species was discovered to be bioluminescent, this never having been recorded previously. According to New Zealand Fungarium curator Dr. Maj Padamsee, "It could have been found before but it just hadn’t been recorded – people who had been out in the forest might have seen something because it’s not very bright… it’s a very pale light colour." The enzymes produced from the compound luciferin gives the mushrooms their glow, as it also does with fireflies and some marine organisms. The discovery of bioluminescence was made during an event dedicated to studying fungus that took place on Stewart Island.
References
Bioluminescent fungi
roseoflava
Taxa named by Greta Stevenson
Fungi described in 1964
Fungi of New Zealand
Fungus species | Mycena roseoflava | [
"Biology"
] | 444 | [
"Fungi",
"Fungus species"
] |
69,819,270 | https://en.wikipedia.org/wiki/Asteridiella%20selaginellae | Asteridiella selaginellae is a species of fungus in the family Meliolaceae, first described by Marie Leonore Farr in 1968. It has been found in Mexico on the leaves of Selaginella pilifera (the resurrection plant).
References
Meliolaceae
Taxa described in 1968
Taxa named by Marie Leonore Farr
Fungus species | Asteridiella selaginellae | [
"Biology"
] | 75 | [
"Fungi",
"Fungus species"
] |
69,819,403 | https://en.wikipedia.org/wiki/Lock%20number | In helicopter aerodynamics, the Lock number is the ratio of aerodynamic forces, which act to lift the rotor blades, to inertial forces, which act to maintain the blades in the plane of rotation. It is named after C. N. H. Lock, a British aerodynamicist who studied autogyros in the 1920s.
Typical rotorcraft blades have a Lock number between 3 and 12, usually approximately 8.
The Lock number is typically 8 to 10 for articulated rotors and 5 to 7 for hingeless rotors. High-stiffness blades may have a Lock number up to 14.
Larger blades have a higher mass and more inertia, so tend to have a lower Lock number. Helicopter rotors with more than two blades can have lighter blades, so tend to have a higher Lock number.
A low Lock number gives good autorotation characteristics due to higher inertia, however this comes with a mass penalty.
Ray Prouty writes, "The previously discussed numbers: Mach, Reynolds and Froude are used in many fields of fluid dynamic studies. The Lock number is ours alone."
See also
Coning
Mach number
Froude number
Reynolds number
References
Helicopter aerodynamics
Engineering ratios | Lock number | [
"Chemistry",
"Mathematics",
"Engineering"
] | 245 | [
"Metrics",
"Engineering ratios",
"Quantity",
"Fluid dynamics stubs",
"Fluid dynamics"
] |
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