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70,395,602 | https://en.wikipedia.org/wiki/HD%20191829 | HD 191829 (HR 7714) is a solitary star located in the southern constellation Telescopium. It has an apparent magnitude of 5.632, making it faintly visible to the naked eye if viewed under ideal conditions. The star is situated at a distance of 710 light years but is receding with a heliocentric radial velocity of .
HD 191829 has a stellar classification of K4 III, indicating that the object is an ageing K-type giant. It has an angular diameter of , yielding a diameter 47 times that of the Sun at its estimated distance. At present it has 117% the mass of the Sun and shines at from its enlarged photosphere at an effective temperature of , giving it an orange glow. HD 191829 has a metallicity 135% that of the Sun and spins modestly with a projected rotational velocity of .
References
Telescopium
K-type giants
191829
7714
99747
Durchmusterung objects
Telescopii, 81 | HD 191829 | [
"Astronomy"
] | 207 | [
"Telescopium",
"Constellations"
] |
70,396,474 | https://en.wikipedia.org/wiki/Square%20root%20of%207 | The square root of 7 is the positive real number that, when multiplied by itself, gives the prime number 7. It is more precisely called the principal square root of 7, to distinguish it from the negative number with the same property. This number appears in various geometric and number-theoretic contexts. It can be denoted in surd form as:
and in exponent form as:
It is an irrational algebraic number. The first sixty significant digits of its decimal expansion are:
.
which can be rounded up to 2.646 to within about 99.99% accuracy (about 1 part in 10000); that is, it differs from the correct value by about . The approximation (≈ 2.645833...) is better: despite having a denominator of only 48, it differs from the correct value by less than , or less than one part in 33,000.
More than a million decimal digits of the square root of seven have been published.
Rational approximations
The extraction of decimal-fraction approximations to square roots by various methods has used the square root of 7 as an example or exercise in textbooks, for hundreds of years. Different numbers of digits after the decimal point are shown: 5 in 1773 and 1852, 3 in 1835, 6 in 1808, and 7 in 1797.
An extraction by Newton's method (approximately) was illustrated in 1922, concluding that it is 2.646 "to the nearest thousandth".
For a family of good rational approximations, the square root of 7 can be expressed as the continued fraction
The successive partial evaluations of the continued fraction, which are called its convergents, approach :
Their numerators are 2, 3, 5, 8, 37, 45, 82, 127, 590, 717, 1307, 2024, 9403, 11427, 20830, 32257… , and their denominators are 1, 1, 2, 3, 14, 17, 31, 48, 223, 271, 494, 765, 3554, 4319, 7873, 12192,….
Each convergent is a best rational approximation of ; in other words, it is closer to than any rational with a smaller denominator. Approximate decimal equivalents improve linearly (number of digits proportional to convergent number) at a rate of less than one digit per step:
Every fourth convergent, starting with , expressed as , satisfies the Pell's equation
When is approximated with the Babylonian method, starting with and using , the th approximant is equal to the th convergent of the continued fraction:
All but the first of these satisfy the Pell's equation above.
The Babylonian method is equivalent to Newton's method for root finding applied to the polynomial . The Newton's method update, is equal to when . The method therefore converges quadratically (number of accurate decimal digits proportional to the square of the number of Newton or Babylonian steps).
Geometry
In plane geometry, the square root of 7 can be constructed via a sequence of dynamic rectangles, that is, as the largest diagonal of those rectangles illustrated here.
The minimal enclosing rectangle of an equilateral triangle of edge length 2 has a diagonal of the square root of 7.
Due to the Pythagorean theorem and Legendre's three-square theorem, is the smallest square root of a natural number that cannot be the distance between any two points of a cubic integer lattice (or equivalently, the length of the space diagonal of a rectangular cuboid with integer side lengths). is the next smallest such number.
Outside of mathematics
On the reverse of the current US one-dollar bill, the "large inner box" has a length-to-width ratio of the square root of 7, and a diagonal of 6.0 inches, to within measurement accuracy.
See also
Square root
Square root of 2
Square root of 3
Square root of 5
Square root of 6
References
Mathematical constants
Quadratic irrational numbers | Square root of 7 | [
"Mathematics"
] | 827 | [
"nan",
"Mathematical objects",
"Numbers",
"Mathematical constants"
] |
70,396,976 | https://en.wikipedia.org/wiki/Fusarubin | Fusarubin is a naphthoquinone derived mycotoxin which is produced by the fungi Fusarium solani. Fusarubin has the molecular formula C15H14O7.
References
Further reading
Mycotoxins
1,4-Naphthoquinones
Methoxy compounds
Triols | Fusarubin | [
"Chemistry"
] | 67 | [] |
70,397,447 | https://en.wikipedia.org/wiki/U%20band | The U band is a range of frequencies contained in the microwave region of the electromagnetic spectrum. Common usage places this range between 40 and 60 GHz, but may vary depending on the source using the term.
References
Microwave bands
Satellite broadcasting | U band | [
"Engineering"
] | 47 | [
"Telecommunications engineering",
"Satellite broadcasting"
] |
70,397,574 | https://en.wikipedia.org/wiki/Medipines | Medipines is an American medical equipment maker which is based in Orange County, California, United States. It is known for its device, AGM100, which is approved for respiratory diagnosis and identifying the symptoms of COVID-19 using parameters such as oxygen saturation levels. The device is being used in the Canada and the U.S.
History
MediPines was incorporated in 2013. They are known for their device, AGM100, which provides non-invasive pulmonary gas exchange measurements in a short period of time. Approved by FDA, the device was developed in California and has been tested at the University of British Columbia. It is in use in Canadian hospitals.
In July 2020, it received the National Consortium for Pediatric Device award for developing a monitor device that displays a critical analysis of patients' breathing samples.
In August 2021, the AGM100 was included in the WHO Compendium.
References
External links
Medical devices
American companies established in 2013
Companies based in Orange County, California | Medipines | [
"Biology"
] | 200 | [
"Medical devices",
"Medical technology"
] |
70,397,989 | https://en.wikipedia.org/wiki/Central%20Yunnan%20Water%20Diversion%20Project | The Central Yunnan Water Diversion Project () is a large-scale civil engineering project under construction that will allow water from the Jinsha River near Lijiang to be transported to Central Yunnan. The total length of the water channels will be , of which will be in tunnels.
The project has a cost of US$ 12.03 billion, largely funded by the Ministry of Water Resources. It is planned for completion by 2026.
Background
Central Yunnan is a region in China where, currently, only of water is available per capita annually, compared to a recommended minimum. At the same time, Central Yunnan accounts for 68% of Yunnan's GDP. The region has suffered from long drought spells, such as a period of 30 months without heavy rains in Kunming. Water scarcity has been described as the "biggest bottleneck restricting the sustainable development of Central Yunnan." The idea of diverting water from the Jinsha River to Central Yunnan was first proposed by Yunnan's vice-governor Zhang Chong in the 1950s.
The water diversion project was included in the Thirteenth Five-Year Plan. In April 2017, it was approved by the State Council.
Construction
The project will include the world's longest water tunnel, the world's largest underground pump room, and largest pump capacity in Asia. In addition, it deals with challenging geological conditions due to passing through a number of faults. It crosses the four major watersheds of Yunnan: that of the Jinsha River, Mekong, Red River, and Nanpan River, as well as crossing the Hengduan Mountains in northwest Yunnan.
Construction commenced on 4 August 2017, with a planned construction time of 8 years. The project includes 58 tunnels with a total length of , 25 inverted siphons, 17 aqueducts, and 15 culverts.
Impact
Once completed, the project would improve water availability for 11 million people, spread over 35 counties in Yunnan and a total area of . Over billion of water would be transported through the channels annually by 2040. This water will be used for domestic and industrial water supply ( million), agricultural water supply ( million), as well as for improving the ecology of lakes in the region ( million).
Since the inlet at the Jinsha River does not include a dam structure, the impact on the source river is expected to be small.
The project is seen as a demonstration project for a future Tibet to Xinjiang water diversion project.
See also
South–North Water Transfer Project, series of projects diverting water from the Yangtze river to the north of China
External links
Official website
References
Aqueducts in China
Irrigation in China
Megaprojects
Macro-engineering | Central Yunnan Water Diversion Project | [
"Engineering"
] | 532 | [
"Macro-engineering",
"Megaprojects"
] |
70,399,451 | https://en.wikipedia.org/wiki/SZ%20Piscium | SZ Piscium is a triple star system in the equatorial constellation of Pisces. The inner pair form a double-lined spectroscopic binary with an orbital period of 3.966 days. It is a detached Algol-type eclipsing binary of the RS Canum Venaticorum class with a subgiant component. (This means the pair have a close but separated orbit with the stars eclipsing one another, and the primary component is an evolving star showing star spots and other magnetic activity.) The system is too faint to be readily visible to the naked eye with a combined apparent visual magnitude of 7.18. It is located at a distance of approximately 306 light years based on parallax measurements.
The variability of this star was reported by A. Jensch in 1934, who published the first elements. In 1956 the spectrum of the system was examined by N. G. Roman, who found the cooler component is the brighter and more evolved. The system was studied by G. A. Bakos and J. F. Heard in 1958, who found a magnitude of 7.72 for the primary eclipse minimum and 7.30 for the secondary. They refined the class estimates, finding the primary is probably a K1IV subgiant in close orbit with an F8V main sequence star. In 1972, H. L. Atkins and D. S. Hall included it on a list of RS Canum Venaticorum type variable systems and showed it has an infrared excess.
S. Jakate and associates in 1976 found that the period of luminosity variation is changing over time. They discovered strong emission in the H and K lines of the K star and noted that it showed intrinsic variability. The system displayed unusual episodes of emission and variation in the Hα line, which was interpreted by astronomers as ejected material possibly forming a transient disk. The orbital period of the system varies in a 56 year cycle with an amplitude of , which may be explained by influences of the stellar wind and magnetic activity.
Significant star spot activity was found all over the K-type star, with variations in the total spot coverage observed over time. It is estimated to be filling 85% of its Roche lobe due to the gravitational influence of the secondary. The rotation period of this star is several times slower than its orbital period, while the rotation of the F-type star is synchronous. Changes in radial velocity of the system over time suggest it is a triple star system with the tertiary component having about 75% of the mass of the Sun and an orbital period of 1,530 days.
References
Further reading
As '35.1934 Piscium'.
K-type subgiants
F-type main-sequence stars
RS Canum Venaticorum variables
Triple stars
Eclipsing binaries
Pisces (constellation)
Durchmusterung objects
219113
114639
Piscium, SZ | SZ Piscium | [
"Astronomy"
] | 596 | [
"Pisces (constellation)",
"Constellations"
] |
61,019,132 | https://en.wikipedia.org/wiki/Social%20golfer%20problem | In discrete mathematics, the social golfer problem (SGP) is a combinatorial-design problem derived from a question posted in the usenet newsgroup sci.op-research in May 1998. The problem is as follows: 32 golfers play golf once a week in groups of 4. Schedule these golfers to play for as many weeks as possible without any two golfers playing together in a group more than once.
More generally, this problem can be defined for any golfers who play in groups of golfers for weeks. The solution involves either verifying or refuting the existence of a schedule and, if such a schedule exists, determining the number of unique schedules and constructing them.
Challenges
The SGP is a challenging problem to solve for two main reasons:
First is the large search space resulting from the combinatorial and highly symmetrical nature of the problem. There are a total of schedules in the search space. For each schedule, the weeks , groups within each week , players within each group , and individual player can all be permuted. This leads to a total of isomorphisms, schedules that are identical through any of these symmetry operations. Due to its high symmetry, the SGP is commonly used as a standard benchmark in symmetry breaking in constraint programming (symmetry-breaking constraints).
Second is the choice of variables. The SGP can be seen as an optimization problem to maximize the number of weeks in the schedule. Hence, incorrectly defined initial points and other variables in the model can lead the process to an area in the search space with no solution.
Solutions
The SGP is the Steiner system S(2,4,32) because 32 golfers are divided into groups of 4 and both the group and week assignments of any 2 golfers can be uniquely identified. Soon after the problem was proposed in 1998, a solution for 9 weeks was found and the existence of a solution for 11 weeks was proven to be impossible. In the case of the latter, note that each player must play with 3 unique players each week. For a schedule lasting 11 weeks, a player will be grouped with a total of other players. Since there are only 31 other players in the group, this is not possible. A solution for 10 weeks could be obtained from results already published in 1996. It was independently rediscovered using a different method in 2004, which is the solution presented below.
There are many approaches to solving the SGP, namely
design theory techniques,
SAT formulations (propositional satisfiability problem),
constraint-based approaches, metaheuristic methods, and radix approach.
The radix approach assigns golfers into groups based on the addition of numbers in base . Variables in the general case of the SGP can be redefined as golfers who play in groups of golfers for any number . The maximum number of weeks that these golfers can play without regrouping any two golfers is .
Applications
Working in groups is encouraged in classrooms because it fosters active learning and development of critical-thinking and communication skills. The SGP has been used to assign students into groups in undergraduate chemistry classes and breakout rooms in online meeting software to maximize student interaction and socialization.
The SGP has also been used as a model to study tournament scheduling.
See also
Steiner system
Kirkman's schoolgirl problem
Euler's officer problem
Round-robin tournament
References
External links
Wolfram Community: Radix Approach to Solving the Social Golfer Problem and Graph Visualization
Wolfram Mathworld: Social Golfer Problem
Combinatorial design
Mathematical problems
Families of sets | Social golfer problem | [
"Mathematics"
] | 721 | [
"Combinatorial design",
"Combinatorics",
"Families of sets",
"Basic concepts in set theory",
"Mathematical problems"
] |
61,019,171 | https://en.wikipedia.org/wiki/Hybrid%20pixel%20detector | Hybrid pixel detectors are a type of ionizing radiation detector consisting of an array of diodes based on semiconductor technology and their associated electronics. The term “hybrid” stems from the fact that the two main elements from which these devices are built, the semiconductor sensor and the readout chip (also known as application-specific integrated circuit or ASIC), are manufactured independently and later electrically coupled by means of a bump-bonding process. Ionizing particles are detected as they produce electron-hole pairs through their interaction with the sensor element, usually made of doped silicon or cadmium telluride. The readout ASIC is segmented into pixels containing the necessary electronics to amplify and measure the electrical signals induced by the incoming particles in the sensor layer.
Hybrid pixel detectors made to operate in single-photon mode are known as Hybrid Photon Counting Detectors (HPCDs). These detectors are designed to count the number of hits within a certain time interval. They have become a standard in most synchrotron light sources and X-ray detection applications.
History
The first hybrid pixel detectors were developed in the 1980s and ‘90s for high energy particle physics experiments at CERN. Since then, many large collaborations have continued to develop and implement these detectors into their systems, such as the ATLAS, CMS and ALICE experiments at the Large Hadron Collider. Using silicon pixel detectors as part of their inner tracking systems, these experiments are able to determine the trajectory of particles produced during the high-energy collisions that they study.
The key innovation for the construction of such large area pixel detectors was the separation of the sensor and the electronics into independent layers. Given that particle sensors require high resistivity silicon, while the readout electronics requires low resistivity, the introduction of the hybrid design allowed to optimize each element individually and later couple them together through a bump-bonding process involving microscopic spot soldering.
It was soon realized that the same hybrid technology could be used for the detection of X-ray photons. By the end of the 1990s the first hybrid photon counting (HPC) detectors developed by CERN and PSI were tested with synchrotron radiation. Further developments at CERN resulted in the creation of the Medipix chip and its variations.
The first large-area HPC detector was built in 2003 at PSI based on the PILATUS readout chip. The second generation of this detector, with improved readout
electronics and smaller pixels, became the first HPC detector to operate routinely at a synchrotron.
In 2006, the company DECTRIS was founded as a spin-off from PSI and successfully commercialized the PILATUS technology. Since then, detectors based on the PILATUS and EIGER systems have been widely used for small-angle scattering, coherent scattering, X-ray powder diffraction and spectroscopy applications. The main reasons for the success of HPC detectors are the direct detection of individual photons and the accurate
determination of scattering and diffraction intensities over a wide dynamic range.
See also
Semiconductor detector
Microstrip detector
Medipix
PILATUS (detector)
References
Particle detectors
Ionising radiation detectors
CERN | Hybrid pixel detector | [
"Technology",
"Engineering"
] | 640 | [
"Ionising radiation detectors",
"Radioactive contamination",
"Particle detectors",
"Measuring instruments"
] |
61,019,928 | https://en.wikipedia.org/wiki/List%20of%20quantum%20computing%20terminology | This is a list of quantum computing terminology.
Qubit.
Quantum circuit.
Quantum logic gate.
Topological quantum computer.
External links
Quantum Computing Glossary by Jack Krupansky
References
Institute of Electrical and Electronics Engineers | List of quantum computing terminology | [
"Engineering"
] | 44 | [
"Electrical engineering organizations",
"Institute of Electrical and Electronics Engineers"
] |
61,019,998 | https://en.wikipedia.org/wiki/Aquatic%20Microbial%20Ecology | Aquatic Microbial Ecology is a monthly peer-reviewed scientific journal covering all aspects of aquatic microbial dynamics, in particular viruses, prokaryotes, and eukaryotes in marine, limnetic, and brackish habitats. The journal was originally established as Marine Microbial Food Webs by P. Bougis and F. Rassoulzadegan in 1985, and acquired its current name in 1995. The journal is currently published by Inter Research.
Abstracting and indexing
The journal is indexed and abstracted in:
References
External links
Microbiology journals
Ecology journals
Academic journals established in 1985
English-language journals
Monthly journals | Aquatic Microbial Ecology | [
"Environmental_science"
] | 130 | [
"Environmental science journals",
"Ecology journals",
"Environmental science journal stubs"
] |
61,020,200 | https://en.wikipedia.org/wiki/Canite | Canite, also known as caneboard, pinboard or softboard, is a low-density fibreboard panel made from sugar cane fibres. It is easy to handle, lightweight and relatively durable. Because of its low environmental footprint it is considered a sustainable building product. It can be used without finish, painted, or rendered with natural lime-based products. It is commonly used for
Interior wall and ceiling lining
Pin boards and bulletin boards
Office partitions
Protective covering boards
Sound insulation and reflected sound reduction
Door fillings
Stucco base
Soundproofing under floorboards
Fire lighter (when saturated with kerosene)
In Australia, canite is commonly sold in 2400 x 1200 mm panels. They are typically 10–13 mm thick, with a density of 350 kg/m3.
References
Building materials | Canite | [
"Physics",
"Engineering"
] | 160 | [
"Building engineering",
"Construction",
"Materials",
"Building materials",
"Matter",
"Architecture"
] |
61,020,826 | https://en.wikipedia.org/wiki/Testosterone%20propionate/testosterone%20cypionate/prasterone | Testosterone propionate/testosterone cypionate/prasterone (TP/TC/DHEA), sold under the brand name Sten, is an injectable combination medication of testosterone propionate (TP), a fast-acting androgen/anabolic steroid, testosterone cypionate (TC), a long-acting androgen/anabolic steroid, and prasterone (dehydroepiandrosterone; DHEA), an androgen and neurosteroid, which has been used to treat andropause, hypogonadism, and impotence in men and breast cancer, fibrocystic breast disease, and low sexual desire in women. It contains 25 mg TP, 75 mg TC, and 20 mg DHEA in 2 mL oil solution provided in ampoules and is administered by intramuscular injection once every 15 to 30 days. The medication was previously marketed in Mexico but appears to no longer available. The duration of action of TP/TC/DHEA has been reported to be approximately 15 to 30 days, due to the long-acting TC component.
See also
List of combined sex-hormonal preparations § Androgens
References
External links
Sten — testosterone cypionate & propionate - Steroids World
Abandoned drugs
Combined androgen formulations | Testosterone propionate/testosterone cypionate/prasterone | [
"Chemistry"
] | 277 | [
"Drug safety",
"Abandoned drugs"
] |
61,020,908 | https://en.wikipedia.org/wiki/Cyclical%20monotonicity | In mathematics, cyclical monotonicity is a generalization of the notion of monotonicity to the case of vector-valued function.
Definition
Let denote the inner product on an inner product space and let be a nonempty subset of . A correspondence is called cyclically monotone if for every set of points with it holds that
Properties
For the case of scalar functions of one variable the definition above is equivalent to usual monotonicity.
Gradients of convex functions are cyclically monotone. In fact, the converse is true. Suppose is convex and is a correspondence with nonempty values. Then if is cyclically monotone, there exists an upper semicontinuous convex function such that for every , where denotes the subgradient of at .
See also
Absolutely and completely monotonic functions and sequences
References
Types of functions
Linear algebra
Functional analysis | Cyclical monotonicity | [
"Mathematics"
] | 173 | [
"Functions and mappings",
"Mathematical analysis",
"Functional analysis",
"Mathematical analysis stubs",
"Mathematical objects",
"Mathematical relations",
"Linear algebra",
"Types of functions",
"Algebra"
] |
61,021,184 | https://en.wikipedia.org/wiki/Progesterone/hydroxyprogesterone%20heptanoate/%CE%B1-tocopherol%20palmitate | Progesterone/hydroxyprogesterone heptanoate/α-tocopherol palmitate (P4/OHPH/VE), sold under the brand name Tocogestan, is a combination medication of progesterone (P4), a short-acting progestogen, hydroxyprogesterone heptanoate (OHPH), a long-acting progestogen, and α-tocopherol palmitate, a prodrug of α-tocopherol and form of vitamin E, which was previously used in France to support pregnancy in women but is no longer available. It contained 50 mg P4, 200 mg OHPH, and 250 mg in 2 mL oil solution, was provided in the form of 2 mL ampoules, and was administered by intramuscular injection.
See also
List of combined sex-hormonal preparations § Progestogens
References
Abandoned drugs
Combination drugs
Progestogens
Vitamin E | Progesterone/hydroxyprogesterone heptanoate/α-tocopherol palmitate | [
"Chemistry"
] | 206 | [
"Drug safety",
"Abandoned drugs"
] |
61,021,369 | https://en.wikipedia.org/wiki/%CE%91-Tocopheryl%20palmitate | α-Tocopheryl palmitate is the palmitate ester of α-tocopherol and is a form of vitamin E. Related compounds include α-tocopheryl acetate and α-tocopheryl succinate.
See also
Progesterone/hydroxyprogesterone heptanoate/α-tocopherol palmitate
References
Abandoned drugs
Palmitate esters
Vitamin E | Α-Tocopheryl palmitate | [
"Chemistry"
] | 88 | [
"Drug safety",
"Abandoned drugs"
] |
61,023,018 | https://en.wikipedia.org/wiki/Crack%20growth%20equation | A crack growth equation is used for calculating the size of a fatigue crack growing from cyclic loads. The growth of a fatigue crack can result in catastrophic failure, particularly in the case of aircraft. When many growing fatigue cracks interact with one another it is known as widespread fatigue damage. A crack growth equation can be used to ensure safety, both in the design phase and during operation, by predicting the size of cracks. In critical structure, loads can be recorded and used to predict the size of cracks to ensure maintenance or retirement occurs prior to any of the cracks failing. Safety factors are used to reduce the predicted fatigue life to a service fatigue life because of the sensitivity of the fatigue life to the size and shape of crack initiating defects and the variability between assumed loading and actual loading experienced by a component.
Fatigue life can be divided into an initiation period and a crack growth period. Crack growth equations are used to predict the crack size starting from a given initial flaw and are typically based on experimental data obtained from constant amplitude fatigue tests.
One of the earliest crack growth equations based on the stress intensity factor range of a load cycle () is the Paris–Erdogan equation
where is the crack length and is the fatigue crack growth for a single load cycle . A variety of crack growth equations similar to the Paris–Erdogan equation have been developed to include factors that affect the crack growth rate such as stress ratio, overloads and load history effects.
The stress intensity range can be calculated from the maximum and minimum stress intensity for a cycle
A geometry factor is used to relate the far field stress to the crack tip stress intensity using
.
There are standard references containing the geometry factors for many different configurations.
History of crack propagation equations
Many crack propagation equations have been proposed over the years to improve prediction accuracy and incorporate a variety of effects. The works of Head, Frost and Dugdale, McEvily and Illg, and Liu on fatigue crack-growth behaviour laid the foundation in this topic. The general form of these crack propagation equations may be expressed as
where, the crack length is denoted by , the number of cycles of load applied is given by , the stress range by , and the material parameters by . For symmetrical configurations, the length of the crack from the line of symmetry is defined as and is half of the total crack length .
Crack growth equations of the form are not a true differential equation as they do not model the process of crack growth in a continuous manner throughout the loading cycle. As such, separate cycle counting or identification algorithms such as the commonly used rainflow-counting algorithm, are required to identify the maximum and minimum values in a cycle. Although developed for the stress/strain-life methods rainflow counting has also been shown to work for crack growth. There have been a small number of true derivative fatigue crack growth equations that have also been developed.
Factors affecting crack growth rate
Regimes
Figure 1 shows a typical plot of the rate of crack growth as a function of the alternating stress intensity or crack tip driving force plotted on log scales. The crack growth rate behaviour with respect to the alternating stress intensity can be explained in different regimes (see, figure 1) as follows
Regime A: At low growth rates, variations in microstructure, mean stress (or load ratio), and environment have significant effects on the crack propagation rates. It is observed at low load ratios that the growth rate is most sensitive to microstructure and in low strength materials it is most sensitive to load ratio.
Regime B: At mid-range of growth rates, variations in microstructure, mean stress (or load ratio), thickness, and environment have no significant effects on the crack propagation rates.
Regime C: At high growth rates, crack propagation is highly sensitive to the variations in microstructure, mean stress (or load ratio), and thickness. Environmental effects have relatively very less influence.
Stress ratio effect
Cycles with higher stress ratio have an increased rate of crack growth. This effect is often explained using the crack closure concept which describes the observation that the crack faces can remain in contact with each other at loads above zero. This reduces the effective stress intensity factor range and the fatigue crack growth rate.
Sequence effects
A equation gives the rate of growth for a single cycle, but when the loading is not constant amplitude, changes in the loading can lead to temporary increases or decreases in the rate of growth. Additional equations have been developed to deal with some of these cases. The rate of growth is retarded when an overload occurs in a loading sequence. These loads generate are plastic zone that may delay the rate of growth. Two notable equations for modelling the delays occurring while the crack grows through the overload region are:
The Wheeler model (1972)
with
where is the plastic zone corresponding to the ith cycle that occurs post the overload and is the distance between the crack and the extent of the plastic zone at the overload.
The Willenborg model
Crack growth equations
Threshold equation
To predict the crack growth rate at the near threshold region, the following relation has been used
Paris–Erdoğan equation
To predict the crack growth rate in the intermediate regime, the Paris–Erdoğan equation is used
Forman equation
In 1967, Forman proposed the following relation to account for the increased growth rates due to stress ratio and when approaching the fracture toughness
McEvily–Groeger equation
McEvily and Groeger proposed the following power-law relationship which considers the effects of both high and low values of
.
NASGRO equation
The NASGRO equation is used in the crack growth programs AFGROW, FASTRAN and NASGRO software. It is a general equation that covers the lower growth rate near the threshold and the increased growth rate approaching the fracture toughness , as well as allowing for the mean stress effect by including the stress ratio . The NASGRO equation is
where , , , , , and are the equation coefficients.
McClintock equation
In 1967, McClintock developed an equation for the upper limit of crack growth based on the cyclic crack tip opening displacement
where is the flow stress, is the Young's modulus and is a constant typically in the range 0.1–0.5.
Walker equation
To account for the stress ratio effect, Walker suggested a modified form of the Paris–Erdogan equation
where, is a material parameter which represents the influence of stress ratio on the fatigue crack growth rate. Typically, takes a value around , but can vary between . In general, it is assumed that compressive portion of the loading cycle has no effect on the crack growth by considering which gives This can be physically explained by considering that the crack closes at zero load and does not behave like a crack under compressive loads. In very ductile materials like Man-Ten steel, compressive loading does contribute to the crack growth according to .
Elber equation
Elber modified the Paris–Erdogan equation to allow for crack closure with the introduction of the opening stress intensity level at which contact occurs. Below this level there is no movement at the crack tip and hence no growth. This effect has been used to explain the stress ratio effect and the increased rate of growth observed with short cracks. Elber's equation is
Ductile and brittle materials equation
The general form of the fatigue-crack growth rate in ductile and brittle materials is given by
where, and are material parameters. Based on different crack-advance and crack-tip shielding mechanisms in metals, ceramics, and intermetallics, it is observed that the fatigue crack growth rate in metals is significantly dependent on term, in ceramics on , and intermetallics have almost similar dependence on and terms.
Prediction of fatigue life
Computer programs
There are many computer programs that implement crack growth equations such as Nasgro, AFGROW and Fastran. In addition, there are also programs that implement a probabilistic approach to crack growth that calculate the probability of failure throughout the life of a component.
Crack growth programs grow a crack from an initial flaw size until it exceeds the fracture toughness of a material and fails. Because the fracture toughness depends on the boundary conditions, the fracture toughness may change from plane strain conditions for a semi-circular surface crack to plane stress conditions for a through crack. The fracture toughness for plane stress conditions is typically twice as large as that for plane strain. However, because of the rapid rate of growth of a crack near the end of its life, variations in fracture toughness do not significantly alter the life of a component.
Crack growth programs typically provide a choice of:
cycle counting methods to extract cycle extremes
geometry factors that select for the shape of the crack and the applied loading
crack growth equation
acceleration/retardation models
material properties such as yield strength and fracture toughness
Analytical solution
The stress intensity factor is given by
where is the applied uniform tensile stress acting on the specimen in the direction perpendicular to the crack plane, is the crack length and is a dimensionless parameter that depends on the geometry of the specimen. The alternating stress intensity becomes
where is the range of the cyclic stress amplitude.
By assuming the initial crack size to be , the critical crack size before the specimen fails can be computed using as
The above equation in is implicit in nature and can be solved numerically if necessary.
Case I
For crack closure has negligible effect on the crack growth rate and the Paris–Erdogan equation can be used to compute the fatigue life of a specimen before it reaches the critical crack size as
Crack growth model with constant value of 𝛽 and R = 0
For the Griffith-Irwin crack growth model or center crack of length in an infinite sheet as shown in the figure 2, we have and is independent of the crack length. Also, can be considered to be independent of the crack length. By assuming the above integral simplifies to
by integrating the above expression for and cases, the total number of load cycles are given by
Now, for and critical crack size to be very large in comparison to the initial crack size will give
The above analytical expressions for the total number of load cycles to fracture are obtained by assuming . For the cases, where is dependent on the crack size such as the Single Edge Notch Tension (SENT), Center Cracked Tension (CCT) geometries, numerical integration can be used to compute .
Case II
For crack closure phenomenon has an effect on the crack growth rate and we can invoke Walker equation to compute the fatigue life of a specimen before it reaches the critical crack size as
Numerical calculation
This scheme is useful when is dependent on the crack size . The initial crack size is considered to be . The stress intensity factor at the current crack size is computed using the maximum applied stress as
If is less than the fracture toughness , the crack has not reached its critical size and the simulation is continued with the current crack size to calculate the alternating stress intensity as
Now, by substituting the stress intensity factor in Paris–Erdogan equation, the increment in the crack size is computed as
where is cycle step size. The new crack size becomes
where index refers to the current iteration step. The new crack size is used to calculate the stress intensity at maximum applied stress for the next iteration. This iterative process is continued until
Once this failure criterion is met, the simulation is stopped.
The schematic representation of the fatigue life prediction process is shown in figure 3.
Example
The stress intensity factor in a SENT specimen (see, figure 4) under fatigue crack growth is given by
The following parameters are considered for the calculation
mm, mm, mm, , ,
MPa,, .
The critical crack length, , can be computed when as
By solving the above equation, the critical crack length is obtained as .
Now, invoking the Paris–Erdogan equation gives
By numerical integration of the above expression, the total number of load cycles to failure is obtained as .
References
External links
Materials science
Fracture mechanics
Mechanical failure
Mechanical failure modes
Solid mechanics
Structural analysis | Crack growth equation | [
"Physics",
"Materials_science",
"Technology",
"Engineering"
] | 2,409 | [
"Structural engineering",
"Solid mechanics",
"Mechanical failure modes",
"Applied and interdisciplinary physics",
"Fracture mechanics",
"Aerospace engineering",
"Structural analysis",
"Technological failures",
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"Mechanics",
"nan",
"Mechanical engineering",
"Materials degr... |
61,023,040 | https://en.wikipedia.org/wiki/Combinatorial%20modelling | Combinatorial modelling is the process which lets us identify a suitable mathematical model to reformulate a problem. These combinatorial models will provide, through the combinatorics theory, the operations needed to solve the problem.
Implicit combinatorial models
Simple combinatorial problems are the ones that can be solved by applying just one combinatorial operation (variations, permutations, combinations, …). These problems can be classified into three different models, called implicit combinatorial models.
Selection
A selection problem requires to choose a sample of k elements out of a set of n elements. It is needed to know if the order in which the objects are selected matters and whether an object can be selected more than once or not. This table shows the operations that the model provides to get the number of different samples for each of the selections:
Examples
1.- At a party there are 50 people. Everybody shakes everybody’s hand once. How often are hands shaken in total?
What we need to do is calculate the number of all possible pairs of party guests, which means, a sample of 2 people out of the 50 guests, so and . A pair will be the same no matter the order of the two people. A handshake must be carried out by two different people (no repetition). So, it is required to select an ordered sample of 2 elements out of a set of 50 elements, in which repetition is not allowed. That is all we need to know to choose the right operation, and the result is:
2.- Unfortunately, you can’t remember the code for your four-digit lock. You only know that you didn’t use any digit more than once. How many different ways do you have to try?
We need to choose a sample of 4 digits out of the set of 10 digits (base 10), so and . The digits must be ordered in a certain way to get the correct number, so we want to select an ordered sample. As the statement says, no digit was chosen more than once, so our sample will not have repeated digits. So, it is required to select an ordered sample of 4 elements out of a set of 10 elements, in which repetition is not allowed. That is all we need to know to choose the right operation, and the result is:
3.- A boy wants to buy 20 invitation cards to give to their friends for his birthday party. There are 3 types of cards in the store, and he likes them all. In how many ways can he buy the 20 cards?
It is required to choose a sample of 20 invitation cards out of the set of 3 types of cards, so and . The order in which you choose the different types of invitations does not matter. As a type of card must be selected more than once, there will be repetitions in our invitation cards. So, we want to select a non ordered sample of 20 elements () out of a set of 3 elements (), in which repetition is allowed. That is all we need to know to choose the right operation, and the result is:
Distribution
In a distribution problem it is required to place k objects into n boxes or recipients. In order to choose the right operation out of the ones that the model provides, it is necessary to know:
Whether the objects are distinguishable or not.
Whether the boxes are distinguishable or not.
If the order in which the objects are placed in a box matters.
The conditions that the distribution must meet. Depending on this, the distribution can be:
Injective distribution: every box must have at most 1 object ()
Surjective distribution: every box must have at least 1 object ()
Bijective distribution: every box must exactly 1 object ()
Distribution with no restrictions
The following table shows the operations that the model provides to get the number of different ways of distributing the objects for each of the distributions:
Stirling numbers of the second kind
Number of partitions of the integer k into n parts
Lah numbers (Stirling numbers of the third kind)
Examples
1.- A maths teacher has to give 3 studentships among his students. 7 of them got an 'outstanding' grade, so they are the candidates to get them. In how many ways can he distribute the grants?
Let's consider the 3 studentships are objects that have to be distributed into 7 boxes, which are the students. As the objects are identical studentships, they are indistinguishable. The boxes are distinguishable, as they are different students. Every studentship must be given to a different student, so every box must have at most 1 object. Furthermore, the order in which the objects are placed in a boxes does not matter, because there cannot be more than one on each box. So, it is a non ordered injective distribution of 3 indistinguishable objects () into 7 distinguishable boxes (). That is all we need to know to choose the right operation, and the result is:
2.- A group of 8 friends rent a 5-room cottage to spend their holidays. If the rooms are identical and no one can be empty, in how many ways can they be distributed in the cottage?
Let's consider the friends are objects that have to be distributed into 5 boxes, which are the rooms. As the objects are different people, they are distinguishable. The boxes are indistinguishable, as they are identical rooms. We can consider it as a non ordered distribution, because the ordered in which everyone is placed in the rooms does not matter. No room can be empty, so every box must have at least 1 object. So, it is a non ordered surjective distribution of 8 distinguishable objects () into 5 indistinguishable boxes (). That is all we need to know to choose the right operation, and the result is:
3.- 12 people are done shopping in a supermarket where 4 cashiers are working at the moment. In how many different ways can they be distributed into the checkouts?
Let's consider the people are objects that have to be distributed into boxes, which are the check-outs. As the people and the checkouts are different, the objects and the boxes are distinguishable. The order in which the objects are placed in the boxes matter, because they are people getting into queues. The statement does not mention any restriction. So, it is an ordered distribution with no restrictions of 12 distinguishable objects () into 4 distinguishable boxes (). That is all we need to know to choose the right operation, and the result is:
Partition
A partition problem requires to divide a set of k elements into n subsets. This model is related to the distribution one, as we can consider the objects inside every box as subsets of the set of objects to distribute. So, each of the 24 distributions described previously has a matching kind of partition into subsets. So, a partition problem can be solved by transforming it into a distribution one and applying the correspondent operation provided by the distribution model (previous table). Following this method, we will get the number of possible ways of dividing the set. The relation between these two models is described in the following table:
This relation let us transform the table provided by the distribution model into a new one that can be used to know the different ways of dividing a set of k elements into n subsets:
Examples
1.- A group of 3 classmates have to make a thesis about 8 different maths topics. In how many ways can they split the work to do?
We need to divide the set of 8 topics into 3 subsets. These subsets will be the topics that each of the students will work on. The elements in the set (topics) are distinguishable. The partitions must be ordered because each one will correspond to a different student, but the topics inside every subset do not have to be ordered because each student can decide which order to follow when working on the thesis. The statement does not mention any restriction of the subsets. So, it is required to divide a set of 8 elements () into 3 ordered subsets () of non ordered elements. That is all we need to know to choose the right operation, and the result is:
See also
Twelvefold way
Sources
Dubois, Jean-Guy. Une systématique des configurations combinatoires simples. Educational Studies in Mathematics 15, 37–57 (1984) doi:10.1007/BF00380438
V. Navarro-Pelayo; Carmen Batanero; Juan D. Godino (1996). Razonamiento Combinatorio en Alumnos de Secundaria.
Rafael Roa (2000). Razonamiento Combinatorio en Estudiantes con Preparación Matemática Avanzada.
Tan Mingshu (2011). Some Combinatorial Identities and Explanations Based on Occupancy Model.
Combinatorics | Combinatorial modelling | [
"Mathematics"
] | 1,829 | [
"Discrete mathematics",
"Combinatorics"
] |
61,024,270 | https://en.wikipedia.org/wiki/Artur%20Lind | Artur Lind (6 April 1927, Vändra – 30 November 1989, Tartu) was an Estonian biologist and is considered to be the founder of molecular biology in Estonia.
Lind studied to be a surgeon at the University of Tartu. Due to an allergic reaction to analgesics used at the time, he was unable to continue working as a surgeon and moved to the faculty of biochemistry instead.
He is credited with the discovery of 5S ribosomal RNA.
His remains are buried in Vana-Jaani cemetery in Tartu. The Sepapaja 6 office building in Ülemiste City is named after Artur Lind.
References
Estonian biologists
1927 births
1989 deaths
Molecular biologists
Estonian surgeons
People from Vändra
University of Tartu alumni
20th-century surgeons
20th-century Estonian biologists | Artur Lind | [
"Chemistry"
] | 164 | [
"Biochemists",
"Molecular biology",
"Molecular biologists"
] |
61,024,303 | https://en.wikipedia.org/wiki/C25H25NO2 | {{DISPLAYTITLE:C25H25NO2}}
The molecular formula C25H25NO2 (molar mass: 371.47 g/mol, exact mass: 371.1885 u) may refer to:
JWH-081
JWH-164
Molecular formulas | C25H25NO2 | [
"Physics",
"Chemistry"
] | 65 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,024,309 | https://en.wikipedia.org/wiki/C27H27NO | {{DISPLAYTITLE:C27H27NO}}
The molecular formula C27H27NO (molar mass: 381.519 g/mol) may refer to:
JWH-147
JWH-370 | C27H27NO | [
"Chemistry"
] | 51 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
61,024,315 | https://en.wikipedia.org/wiki/C21H23NO | {{DISPLAYTITLE:C21H23NO}}
The molecular formula C21H23NO (molar mass: 305.41 g/mol, exact mass: 305.1780 u) may refer to:
Dapoxetine
Indapyrophenidone
JWH-167 (1-pentyl-3-(phenylacetyl)indole)
Molecular formulas | C21H23NO | [
"Physics",
"Chemistry"
] | 87 | [
"Molecules",
"Set index articles on molecular formulas",
"Isomerism",
"Molecular formulas",
"Matter"
] |
61,024,736 | https://en.wikipedia.org/wiki/List%20of%20stars%20that%20have%20unusual%20dimming%20periods | This list of stars that have unusual dimming periods is a table of stars that have been observed to darken and brighten and do not appear to be eclipsing binaries or intrinsic variables. It is based on studies searching for analogs of Tabby's Star.
The listing here is ordered alphabetically.
List
See also
BD+20°307
Disrupted planet
Ecliptic Plane Input Catalog (EPIC)
Gaia16aye
List of transiting circumsecondary disks
Lists of astronomical objects
List of semiregular variable stars
Lists of stars
List of variable stars
Search for extraterrestrial intelligence
WD 0145+234 (star disrupting an exoasteroid)
Notes
References
External links
SIMBAD Astronomical Database by the Centre de données astronomiques de Strasbourg
Dim
Stars, dim | List of stars that have unusual dimming periods | [
"Astronomy"
] | 170 | [
"Astronomy-related lists",
"Lists of superlatives in astronomy"
] |
61,025,200 | https://en.wikipedia.org/wiki/Critical%20green%20inclusion | Critical green inclusions, also known as green neutrophilic inclusions and informally, death crystals or crystals of death, are amorphous blue-green cytoplasmic inclusions found in neutrophils and occasionally in monocytes. They appear brightly coloured and refractile when stained with Wright-Giemsa stain. These inclusions are most commonly found in critically ill patients, particularly those with liver disease, and their presence on the peripheral blood smear is associated with a high short-term mortality rate.
Clinical significance
Critical green inclusions are a rare finding, and when found they are suggestive of a poor prognosis, hence the colloquial term death crystals. A 2018 review found that 56% of patients died shortly after the inclusions were first identified (usually within two weeks). However, critical green inclusions are of limited utility for predicting mortality because they are usually found in severely ill patients whose poor prognosis is already evident for other reasons by the time the crystals are detected.
The inclusions were once hypothesized to be bile products phagocytized during fulminant hepatic injury, due to the high incidence of critical green inclusions observed in cases of acute hypoxic and ischaemic hepatitis. However, recent studies have highlighted that the inclusions stain positive for Oil Red O as opposed to bile stains, suggesting high lipid content. Additionally, some cases with critical green inclusions were not associated with notable hepatic injury. Currently, it is suggested that critical green inclusions are more likely to be phagocytized products of lysosomal degradation related to tissue injury.
Composition
The composition of the inclusions is not well understood, but transmission electron microscopy has shown that they are rich in lipids and possibly related to lipofuscin. Microscopic examination of liver tissue in patients with critical green inclusions has demonstrated prominent deposition of lipofuscin, suggesting that the white blood cell inclusions represent phagocytosis of this substance following severe injury to the liver.
References
External links
Images of critical green inclusions at the American Society of Hematology image bank
Histopathology
Hematology
Hematopathology
Abnormal clinical and laboratory findings for blood | Critical green inclusion | [
"Chemistry"
] | 458 | [
"Histopathology",
"Microscopy"
] |
61,026,454 | https://en.wikipedia.org/wiki/Hannah%20Cloke | Hannah Louise Cloke is a British hydrologist who is Professor of Hydrology at the University of Reading. She was awarded the European Geosciences Union Plinius Medal in 2018 and appointed Officer of the Order of the British Empire in the 2019 Birthday Honours.
Early life and education
Cloke's father was a geography teacher and her uncle is a professor of human geography. She studied geography at the University of Bristol where she earned her bachelor's degree in 1999 and a PhD in 2003. Cloke worked at the Joint Research Centre on the European Flood Awareness System.
Research and career
Cloke joined the Department of Geography at King's College London. She was part of the Europeanizing Flood Forecasting program, which looked at flood forecasting and management in the European Union.
She joined the University of Reading in 2012, where she is a professor of hydrology. Cloke co-directs the Water@Reading group, which concentrates on water science, policy and societal impacts. She is the Director of the Natural Environment Research Council programme Flooding from Intense Rainfall. She is interested in flood forecasting and risk management, leading the project TENDERLY (Towards END-to End flood forecasting and a tool for ReaL-time catchment susceptibilitY). She works with the Met Office, Environmental Agency and the European Centre for Medium-Range Weather Forecasts (ECMWF). Cloke's Global Flood Awareness System is a partnership between the European Commission and the ECMWF, and provides hydrological monitoring and forecasting that is independent of political boundaries. She was also involved with the Natural Environment Research Council projects Susceptibility of catchments to INTense RAinfall and flooding (SINATRA) and Improving Predictions of Drought for User Decision-Making (IMPETUS). Since climate change will make flooding more probable, Cloke says that we should start to take precautions to protect homes and livelihoods.
Cloke's research helps policymakers make better decisions about flood preparation. She has discussed the problems with the United Kingdom's flood defence systems. She called for the National Flood Resilience Review to evaluate how flood risks are likely to change in different locations across the United Kingdom. She is supported by the European Commission Horizon 2020 programme. In 2019 Cloke created IMPREXive, a game that allowed players to control flood forecasting during a deluge. The information provided to the players is not always correct; and decisions must be made to keep cities safe.
She has written for The Conversation and The Guardian. She was the guest on The Life Scientific on BBC Radio 4 in October 2021.
Awards and honours
Her awards and honours include;
2013 Natural Environment Research Council Early Career Impact Award
2016 Guardian Research Impact Award runner-up
2018 European Geosciences Union Plinius Medal
2019 Officer of the Order of the British Empire
References
External links
Hydrologists
Year of birth missing (living people)
Living people
Officers of the Order of the British Empire
British women scientists
Women hydrologists | Hannah Cloke | [
"Environmental_science"
] | 599 | [
"Hydrology",
"Hydrologists"
] |
57,926,868 | https://en.wikipedia.org/wiki/List%20of%20informally%20named%20dinosaurs | This list of informally named dinosaurs is a listing of dinosaurs (excluding Aves; birds and their extinct relatives) that have never been given formally published scientific names. This list only includes names that were not properly published ("unavailable names") and have not since been published under a valid name (see list of dinosaur genera for valid names). The following types of names are present on this list:
Nomen nudum, Latin for "naked name": A name that has appeared in print but has not yet been formally published by the standards of the International Commission on Zoological Nomenclature. Nomina nuda (the plural form) are invalid, and are therefore not italicized as a proper generic name would be.
Nomen manuscriptum, Latin for "manuscript name": A name that appears in manuscript but was not formally published. A nomen manuscriptum is equivalent to a nomen nudum for everything except the method of publication, and description.
Nomen ex dissertationae, Latin for "dissertation name": A name that appears in a dissertation but was not formally published.
Nicknames or descriptive names given to specimens or taxa by researchers or the press.
A
Alamotyrannus
"Alamotyrannus" ("Ojo Alamo tyrant") is the informal placeholder name given to an as yet undescribed genus or species of tyrannosaurid from the Late Cretaceous period of North America. The fossils of this animal originate from the Ojo Alamo Formation in New Mexico and they were discovered during the early 2000s. The suggested binomial "Alamotyrannus brinkmani", was created when the paper describing the genus was written in 2013. "Alamotyrannus" lived during the early Maastrichtian.
Specimen ACM 7975, a jaw discovered in the Ojo Alamo Formation, New Mexico in 1924, has been tentatively identified as Gorgosaurus libratus but may instead belong to "Alamotyrannus" as per Dalman & Lucas (2013) and McDavid (2022). This specimen has been mentioned in a 2016 publication by Dalman and Lucas as an indeterminate tyrannosaurid without generic attribution, and it's noted that the specimen is under study by the senior author. Photograph taken by McDavid (2022) shows the specimen on display in the Beneski Museum of Natural History.
Alan the Dinosaur
"Alan the Dinosaur" is the name given to a sauropod caudal vertebra (YORYM:2001.9337) found in 1995 in the Saltwick Formation (Middle Jurassic, Aalenian) of Whitby, England. It is the oldest sauropod found in the United Kingdom, dating back 176-172 million years ago. Its name reference that of its discoverer, Alan Gurr, and the fact that it is not identifiable to species level. An analysis done in 2015 found that it was a member of Eusauropoda, could be excluded from Diplodocoidea, and was most similar to Cetiosaurus.
The fossil of "Alan" is housed in the Yorkshire Museum, where it forms part of the Yorkshire's Jurassic World exhibit, featuring a VR recreation.
Allosaurus robustus
"Allosaurus robustus" is an informal name used for specimen "NMV P150070", a theropod astragalus known from the Wonthaggi Formation (Early Cretaceous) of Victoria, Australia. When first studied, it was thought to have belonged to a species of Allosaurus. Samuel Welles challenged this identification as he thought that the astragalus belonged to an ornithomimid, but the original authors defended their classification. Sometime in the early 2000s, Daniel Chure examined the bone and found that it did not represent a new species of Allosaurus, but could still represent an allosauroid. At the same time, Yoichi Azuma and Phil Currie noted that the astragalus resembled that of their new genus Fukuiraptor. It may well represent a theropod related to Australovenator, though some argue that it could represent an abelisauroid. A 2019 study strongly supported a megaraptoran affinity for the astragalus.
The name "Allosaurus robustus", first confined as a museum label, was first published by Chure in 2000.
Amargastegos
"Amargastegos" is an informal genus of extinct stegosaurid ornithischian dinosaur known from the La Amarga Formation of Argentina, named by Roman Ulansky in 2014 on the basis of MACN N-43 (some dorsal osteoderms, the cervical and caudal vertebrae, and one skull bone), and the type species is "A. brevicollum". In 2016, Peter Malcolm Galton and Kenneth Carpenter declared it a nomen nudum, establishing it as an indeterminate stegosaur.
Amphicoelias brontodiplodocus/Barackosaurus
"Barackosaurus" is the informal name created in 2010 which is used for a sauropod found in Kimmeridgian-aged sediments pertaining to the Morrison Formation, Wyoming. It was found in the Dana Quarry and "Barackosaurus" was supposedly 20 meters long and weighed 20 tons. In 2010, an article was made available, but not formally published, by Henry Galiano and Raimund Albersdorfer in which they dubbed the Dana Quarry specimens which had already been referred to as "Barackosaurus" as "Amphicoelias brontodiplodocus". The specific name referred to their hypothesis based on these specimens that nearly all Morrison diplodocid species are either growth stages or represent sexual dimorphism among members of the genus Amphicoelias, but this analysis was met with skepticism and the publication itself has been disclaimed by its lead author, explaining that it is "obviously a drafted manuscript complete with typos, etc., and not a final paper. In fact, no printing or distribution has been attempted". As of 2015, they are now on display at the Lee Kong Chian Natural History Museum in Singapore.
Andhrasaurus
"Andhrasaurus" is an informal genus of extinct armored ornithischian dinosaur from the Kota Formation of India. The proposed species is "A. indicus". Ulansky (2014) coined the name for skull elements, about 30 osteoderms, and the extremities of vertebrae and limbs, all preserved in the collections of the GSI and assigned to Ankylosauria by Nath et al. (2002). In 2016, Peter Malcolm Galton and Kenneth Carpenter noted that "Andhrasaurus" did not meet ICZN requirements and therefore declared it a nomen nudum, listing it as Thyreophora indet., while noting that the jawbones described by Nath et al. (2002) belonging to crocodylomorphs. The dermal armor informally named "Andhrasaurus" was redescribed by Galton (2019), referring the material to Ankylosauria.
Angeac ornithomimosaur
The "Angeac ornithomimosaur" is an informal name given to an unnamed ornithomimosaur taxon known from the Early Cretaceous (previously thought to be Hauterivian-Barremian in age, but now thought to be Berriasian aged) Angeac-Charente bonebed (part of the stratigraphy of the Aquitaine Basin) near Angeac-Charente in western France. The taxon is toothless and is known from numerous disarticulated remains representing at least 70 individuals covering almost all of the skeleton, some remains were described by Allain et al. (2014).
Angloposeidon
"Angloposeidon" is the informal name given to a sauropod dinosaur from the Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight in southern England. It was a possible brachiosaurid but has not been formally named. Darren Naish, a notable vertebrate palaeontologist, has worked with the specimen and has recommended that this name only be used informally and that it not be published. However, he published it himself in his book Tetrapod Zoology Book One from 2010. The remains consist of a single cervical vertebra (MIWG.7306), which indicate it was a very large animal, 20 metres or greater in length.
Archaeoraptor
"Archaeoraptor" is the informal generic name for an important fossil from China that was later discovered to have been fabricated from multiple unrelated fossils. The name was created in an article published in National Geographic magazine in 1999, where the magazine claimed that the fossil was a "missing link" between birds and terrestrial theropod dinosaurs. Even prior to this publication there had been severe doubts about the fossil's authenticity. Further scientific study showed it to be a forgery constructed from rearranged pieces of real fossils from different species. Zhou et al. found that the head and upper body actually belong to a specimen of the primitive fossil bird Yanornis, and another 2002 study found that the tail belongs to a small winged dromaeosaur, Microraptor, named in 2000. The legs and feet belong to an as yet unknown animal.
Archbishop
"The Archbishop" is a giant brachiosaurid sauropod dinosaur similar to Brachiosaurus and Giraffatitan. It was long considered a specimen of Brachiosaurus (now Giraffatitan) brancai due to being found in the same formation in Tendaguru, Tanzania. However, the "Archbishop" shows significant differences including a unique vertebral morphology and a proportionally longer neck, that indicates it is a different, previously unknown genus and species. It was discovered by Frederick Migeod in 1930. "The Archbishop" is a nickname that functions as a placeholder – the specimen currently has no scientific name. The specimen is currently housed in the Natural History Museum in London, and will eventually be re-described by Dr. Michael P. Taylor of Bristol University. In May 2018, Taylor started to work on describing the Archbishop.
Atlantohadros
"Atlantohadros", more commonly known as the "Merchantville hadrosaur", is an informally named hadosaurid dinosaur that lived in the Merchantville Formation in the northeastern United States. Brown (2021) found "Atlantohadros" to be more derived than Tethyshadros but less derived than Saurolophinae and Lambeosaurinae. The name was intended to be used in that publication, but was cut for unknown reasons; initial versions of Brown (2021) contained the word "Atlantohadros" superimposed over "Merchantville Taxon" in a cladogram; subsequent corrections have erased the genus name entirely.
Three specimens were discovered northwest of Freehold near Manalapan–Marlboro township line in Monmouth County during the 1970s. These are: YPM VPPU.021813, YPM VPPU.021813, and AMNH 13704, with YPM VPPU.021813 possibly belonging to the same individual as YPM VPPU.021813 due similar weathering, size and the same horizon. These specimens consist of both coracoids, both scapulae, a femur, a fragmentary proximal tibia, and a dentary from a cast of the specimen (the original likely lost in YPM's catalogue) in the adult specimen, as well as a rib, a femur and long bone portions in the juvenile. AMNH 13704, id a partial dentary of a probable perinate. Scattered bones associated with these include a quadrate, several partial maxilla portions, a partial jugal, skull roof fragments and several rib fragments.
B
Baguasaurus
"Baguasaurus" (meaning "Bagua lizard") is the informal name given to an as yet undescribed genus of lithostrotian sauropod dinosaur from the Late Cretaceous (Campanian – Maastrichtian-aged) Chota Formation of Peru. The proposed holotype, consisting of caudal vertebrae, was first mentioned in a review of the Chota Formation by Mourier et al. (1988), and the name "Baguasaurus" was coined by Larramendi & Molina Pérez (2020)."Baguasaurus" was estimated to be long and weighed .
Balochisaurus
"Balochisaurus" (meaning "Balochi lizard", for the Baloch tribes of Pakistan) is an informal taxon of titanosaurian sauropod dinosaur from the Late Cretaceous of Pakistan. The proposed species is "B. malkani". The discovery was made (along with other dinosaur specimens) in 2001 near Vitariki by a team of paleontologists from the Geological Survey of Pakistan. Described in 2006 by M.S. Malkani, the genus is based on seven tail vertebrae found in the Maastrichtian-age Vitakri Member of the Pab Formation, with additional vertebrae and a partial skull assigned to it. Balochisaurus was assigned to the family "Balochisauridae" along with "Marisaurus". It was considered invalid by Wilson, Barrett and Carrano (2011).
Barnes High Sauropod
The "Barnes High sauropod" is the informal name given to MIWG-BP001, an undescribed sauropod dinosaur specimen from the Wessex Formation on the Isle of Wight. It was discovered in the cliffs around Barnes High in 1992 and is currently owned by the privately run unaccredited Dinosaur Farm Museum near Brighstone, the ownership situation was described as "complex" and the specimen is currently inaccessible to researchers. It is roughly 40% complete and consists of a "Partial postcranial skeleton, including presacral vertebrae, anterior caudal vertebrae, girdle and limb elements" including a largely complete forelimb. It has been suggested to be a brachiosaurid and is possibly synonymous with the earlier named Eucamerotus due to similarities with the vertebrae.
Bayosaurus
"Bayosaurus" is the informal name given to an as yet undescribed genus of theropod dinosaur. The name was coined by paleontologists Rodolfo Coria, Philip J. Currie, and Paulina Carabajal in 2006. It apparently was an abelisauroid from the Turonian Cerro Lisandro Formation of Neuquén, Argentina, around long. The specimen is MCF-PVPH-237, including dorsal and sacral vertebrae, a fragmentary pelvis, and other partial bones, which were discovered in 2000. The name was used in a phylogenetic analysis to indicate the position of MCF-PVPH-237.
Beelemodon
"Beelemodon" is the informal name given to an undescribed theropod genus from the Late Jurassic, possibly belonging to a coelurosaur. The fossils include two teeth found in Wyoming, United States. The name appeared in print in 1997, when paleontologist Robert T. Bakker mentioned it in a symposium for the Academy of Natural Sciences. The teeth are most similar to Compsognathus, but have no unique features and also share similarities with Protarchaeopteryx and dromaeosaurids.
Biconcavoposeidon
"Biconcavoposeidon" is the placeholder name for AMNH FARB 291, five consecutive posterior dorsal vertebrae of a brachiosaurid sauropod, from the Late Jurassic Morrison Formation, Wyoming. Not much else is currently known about "Biconcaveoposeidon", except that it was discovered in the Bone Cabin quarry in 1898.
Bihariosaurus
"Bihariosaurus" (meaning "Bihor lizard") is an invalid genus of iguanodontian dinosaur from Early Cretaceous Bauxite of Cornet, Romania. The type species, "Bihariosaurus bauxiticus", was named but not described by Marinescu in 1989. It was similar to Camptosaurus, and was an iguanodont. The original publication of the taxon did not include sufficient description, and the illustrations cannot distinguish it from any other ornithopod.
Biscoveosaurus
"Biscoveosaurus" is the informal name of an ornithopod dinosaur specimen from the Early Maastrichtian age Snow Hill Island Formation of James Ross Island, Antarctica. It comes from the Cape Lamb Member of the formation, the same member as Morrosaurus, another basal ornithopod. As such, it's been suggested it may be a secondary specimen of that species, but as the holotype of Morrosaurus is fragmentary and doesn't overlap with the material of "Biscoveosaurus", this can't as yet be tested. The specimen consists of dentaries, teeth, a braincase, parts of the maxillae, forelimb elements, assorted vertebrae, and the pectoral girdle; this makes it unique compared to the other James Ross Island ornithopods, which do not have both cranial and postcranial remains. It has been estimated the animal would have been about in length.
C
Capitalsaurus
"Capitalsaurus" is the informal genus name given to a tailbone belonging to a large theropod dinosaur that lived during the Early Cretaceous. It was discovered on 28 January 1898, by construction workers excavating a sewer at the intersection of Washington, D.C.'s First and F Streets SE. The only known specimen, it was assigned two different species designations – Creosaurus potens and Dryptosaurus potens – and eventually overturned each time. In the 1990s, the paleontologist Peter Kranz asserted that it represented a unique type of dinosaur and assigned it the name "Capitalsaurus". He successfully campaigned through local schools to make "Capitalsaurus" the official dinosaur of Washington, D.C., which became law in 1998. A year later, the district further recognized F Street at the discovery site as Capitalsaurus Court. It designated 28 January 2001, as Capitalsaurus Day.
Changdusaurus
"Changdusaurus" (also known as "Changtusaurus") is the informal name given to a genus of dinosaur from the Late Jurassic Period. It lived in what is now China. "Changdusaurus" is classified as a stegosaurid. The type species was named "Changdusaurus laminoplacodus" by Zhao in 1983, but it has never been formally described, and remains a nomen nudum. One source indicates the fossils have been lost.
Comanchesaurus
"Comanchesaurus" is a nomen ex dissertationae for fossilized remains from the Late Triassic of New Mexico that were initially interpreted as belonging to a theropod dinosaur. The remains, NMMNH P-4569, consist of a partial skeleton including vertebral centra and hindlimb bones, and came from the Norian-age Upper Triassic Bull Canyon Formation of Guadalupe County. Adrian Hunt, in his unpublished dissertation, proposed the name "Comanchesaurus kuesi" for the specimen, but the name was never adopted, and was first referred to in the scientific literature in a 2007 redescription of Late Triassic North American material thought to belong to dinosaurs (Nesbitt, Irmis, and Parker, 2007). In the redescription, the authors found the material to belong to a "possible indeterminate saurischian".
Cryptoraptor
"Cryptoraptor" is a nomen ex dissertationae for fossilized remains from the Late Triassic of New Mexico that were initially interpreted as belonging to a theropod dinosaur. The remains, NMMNH P-17375, consist of a partial skeleton including partial hindlimb and pelvic bones, and came from the Norian-age Upper Triassic Bull Canyon Formation of Quay County. Adrian Hunt, in his unpublished dissertation, proposed the name "Cryptoraptor lockleyi" for the specimen, but the name was never adopted, and was first referred to in the scientific literature in a 2007 redescription of Late Triassic North American material thought to belong to dinosaurs. In the redescription, the authors found the material to belong to an intermediate archosaur, as no features exclusive to dinosaurs could be identified.
Cryptotyrannus
"Cryptotyrannus" (meaning "secret/hidden tyrant"), more commonly known as the "Merchantville tyrannosauroid", is an informally named tyrannosauroid dinosaur that lived in the Merchantville Formation. It was informally named by Brown (2021), who found it to be the sister taxon of Dryptosaurus, reinstating Dryptosauridae. The name appeared in the initial version of Brown's paper, superimposed over "Merchantville Taxon" in a cladogram; a subsequent correction has erased the name entirely.
"Cryptotyrannus" is known from two specimens discovered during the 1970s, the holotype YPM VPPU.021795 and the paratype YPM VPPU.022416. Similar coloration and weathering indicate that these are probably the same individual. These are a partial foot bone and one caudal vertebrae. However, a skeletal produced for the paper depicts a hand claw. The foot morphology is consistent with tyrannosaurs, being extremely similar to the Dryptosaurus aquilunguis. Autapomorphies include a metatarsal IV that is far more gracile and IV in proximal view also has a triangular, rather than subrectangular in outline. The holotype was once tentatively assigned to "Coelosaurus" antiquus. Shark bites present on the holotype suggest that the specimen's fragmentary nature is due to predation or scavenging by marine predators.
D
Dachongosaurus
"Dachongosaurus" is the informal name given to an undescribed genus of sauropod dinosaur from the Early Jurassic of China. It is known from fossils including at least a partial articulated skeleton from the Dark Red Beds of the Lower Lufeng Series (Sinemurian stage) in Yunnan. Possibly a cetiosaur, the "type species" is "Dachongosaurus yunnanensis", coined by Zhao in 1985. An alternate spelling is "Dachungosaurus". As with other informal names coined by Zhao in 1985 and 1983, nothing has since been published, and the remains may have been redescribed under another name.
Dongshengosaurus
"Dongshengosaurus" is the informal name given to an undescribed genus of iguanodontian dinosaur from the Early Cretaceous of Liaoning, China. the "type species", "D. sinensis", was named by Pan Rui in his 2009 thesis. It is known from a partial juvenile skeleton discovered from the Yixian Formation.
Damalasaurus
"Damalasaurus" (meaning "Damala lizard") is the informal name given to a genus of herbivorous dinosaur from the Early Jurassic. It was a sauropod, though its exact classification within the clade is unknown. Fossils of "Damalasaurus", including a rib, have been found in the Middle Daye Group of Tibet. Species attributed to this genus include "Damalasaurus laticostalis" and "D. magnus", although it is possible that both names refer to the same species.
Duranteceratops
"Duranteceratops" is a purported new taxon of chasmosaurine ceratopsid from the Hell Creek Formation. In 2012, a ceratopsid skull supposedly distinguishable from Triceratops was unearthed in South Dakota by a fossil poacher named John Carter. Though it has yet to be published, according to the Prehistoric Times issue no. 121 from Spring 2017, the specimen is to be named "Duranteceratops".
E
EK troodontid
The "EK troodontid" (specimen SPS 100/44) is an unnamed genus of troodontid dinosaur discovered in Mongolia. In the scientific literature it is referred to as the "EK troodontid", after the Early Cretaceous sediments in which it was found. SPS 100/44 was discovered by Sergei Mikhailovich Kurzanov during the 1979 Soviet-Mongolian Paleontological Expedition. It was found in deposits of the Barunbayaskaya Svita at the Khamareen Us locality, Dornogov (southeastern Gobi Desert), in the Mongolian People's Republic. SPS 100/44 was described by Rinchen Barsbold and colleagues in 1987.
Its fossil remains include an incomplete skeleton consisting of the braincase, posterior parts of the lower mandibles, a maxillary fragment with teeth, parts of five cervical vertebrae (cervicals ?2-?6), an articulated right manus with partial semilunate, left manus phalanx I-1, distal end of the left femur, and fragmentary left and right pedes. Barsbold pointed out that the specimen was smaller and from older sediments than other known troodontids, but it had some features of the skull that could have made it a juvenile. Barsbold also indicated the high degree of fusion of the bones of the skull and the unusual foot morphology to indicate that it might be an adult of an unknown taxon. Barsbold took the conservative position and did not name this specimen because it was not complete enough to rule out the possibility that it was a juvenile of a known genus of troodontid. Barsbold also noted that the naturally articulated manus of SPS 100/44 showed no signs of an opposable third digit, as was suggested for Troodon by Russell and Seguin in 1982. Turner and colleagues, in 2007, found the EK troodontid to be a distinct basal genus of troodontid, in a polytomy with Jinfengopteryx and a clade of more derived troodontids.
Eoplophysis
"Eoplophysis" is a genus of stegosaur known from the Middle Jurassic Cornbrash Formation, Sharp's Hill Formation, and Chipping Norton Formation of England. It was originally named Omosaurus vetustus by the renowned German paleontologist Friedrich von Huene. The holotype, OUM J.14000, is a right femur of a juvenile individual from the Middle Jurassic (upper Bathonian) Cornbrash Formation of Oxfordshire, England, although it was probably reworked from the slightly older Forest Marble Formation in view of its eroded nature. Because of the renaming of Omosaurus, an occupied name, as Dacentrurus, O. vetustus was renamed into a Dacentrurus vetustus in 1964. In the 1980s, researcher Peter Malcolm Galton reviewed all known stegosaur material from the Bathonian of England and concluded that Omosaurus vetustus was valid and should be tentatively referred to Lexovisaurus. However, the species was later considered a nomen dubium in both reviews of Stegosauria. In their alpha-taxonomic review of stegosaurs, Susannah Maidment and her colleagues noted that OUM J.14000 shares characters present in both sauropods and stegosaurs, but that it lacks synapomorphies exclusive to Stegosauria and assigned it as a Dinosauria indet. Nevertheless, the amateur paleontologist Roman Ulansky coined the new genus "Eoplophysis" ("Dawn Armed Form") for O. vetustus, noting differences with the femora of other stegosaurs.
Eugongbusaurus
"Eugongbusaurus" is the informal name (nomen nudum) proposed for a neornithischian found in the Oxfordian-age Shishugou Formation of Xinjiang, China. The intended type species, "Gongbusaurus" wucaiwanensis, was described by Dong Zhiming in 1989 for two partial skeletons as a second species of the poorly known tooth taxon Gongbusaurus. Fragmentary skeleton IVPP 8302, the type specimen for the new species, included a partial lower jaw, three tail vertebrae, and a partial forelimb. Second specimen IVPP 8303 consisted of two hip vertebrae, eight tail vertebrae, and two complete hind limbs. Dong estimated it as around long, and considered it to be a strong runner. He assigned the genus Gongbusaurus to the Hypsilophodontidae, a paraphyletic grade of small herbivorous bipedal dinosaurs. Because dinosaur teeth are generally not distinctive enough to hold a name, it is unsurprising that other paleontologists have suggested removing "G." wucaiwanensis from Gongbusaurus and giving it its own genus. The possible replacement name "Eugongbusaurus" leaked out accidentally and remains informal.
F
Fendusaurus
"Fendusaurus" is a nomen ex dissertatione proposed by Fedak (2006) for FGM 998GF13-II, which includes a skull. Other specimens referred to "Fendusaurus" are FGM998GF13-I, FGM998GF13-III, FGM998GF69, FGM998GF9, and FGM998GF18, all found by a crew from the Princeton University. All the specimens include femora and coracoids, and although they each share slightly different features, the differences are credited to intra-specific variation. Known specimens of "Fendusaurus" were previously classified as cf. Ammosaurus. The femora and coracoids also help identify different individuals, and Timothy J. Fedak, the describer of the specimens, found that each block represented about one individual. "Fendusaurus" is known from the Early Jurassic (Hettangian) McCoy Brook Formation of Wasson Bluff, Nova Scotia. It is the first non-avian dinosaur from Nova Scotia. As five specimens of "Fendusaurus" are from the McCoy Brook Formation, the formation is the richest prosauropod site in North America. The formation is also similar to other formations of North America and Asia, as it lacks any remains presently assigned to Anchisaurus. Fedak places "Fendusaurus" as a genus of the family Massospondylidae.
The specimens of "Fendusaurus" include mostly crushed vertebrae, along with appendicular elements. They are distinguishable from Anchisaurus by the morphology of both the ilium and sacral vertebrae. However, in some specimens, the morphology of the femora and coracoids are quite different, which led Fedak to speculate that more than one species may have been present. "Fendusaurus", according to Fedak, can be distinguished from all closely related sauropodomorphs by the extreme elongation of the cervical vertebrae; a four vertebrae sacrum that includes a dorsosacral and caudosacral; the elongate postacetabular process of the ilium; and an expanded anterior distal process of the tibia.
Ferganastegos
"Ferganastegos" is a dubious genus of stegosaur from the Middle Jurassic (Callovian) Balabansai Formation of Fergana Valley, Kyrgyzstan. The holotype of "Ferganastegos callovicus", IGB 001, consists of four posterior dorsal vertebrae. Although Averianov et al. did not consider the vertebrae diagnostic to genus, the freelance Russian dinosaur enthusiast and amateur paleontologist Roman Ulansky decided that the differences between IGB 001 and other stegosaurs were sufficient to warrant a binomial for IGB 001, "Ferganastegos callovicus" (Callovian roof from Fergana Valley), despite the fact he did not examine the material himself. Other researchers still contend that the material is not diagnostic and that the genus is a nomen dubium.
Ferropectis
"Ferropectis" is a nodosaurid ankylosaur from the Late Cretaceous (Cenomanian) Eagle Ford Group in Texas that was named in a 2018 dissertation by Matt Clemens. The intended type species is "Ferropectis brysorum", and in the phylogenetic analysis it was placed as the sister taxon to Borealopelta in a clade including Hungarosaurus, Europelta, and Pawpawsaurus.
Francoposeidon
"Francoposeidon" (meaning "French earthquake god") is the informal name given to an as yet undescribed genus of turiasaurian sauropod dinosaur from the Early Cretaceous (Hauterivian)-aged Angeac-Charente bonebed of France. The proposed type species is "F. charantensis", and the remains consist of a braincase, some skull bones, teeth, cervical, dorsal and caudal vertebrae, chevrons, pelvic girdle and all the limb bones" alongside isolated teeth, belonging to at least 7 individuals. The length of the femur was measured to be around , (± ), making "Francoposeidon" one of the largest known sauropods discovered in Europe.
Futabasaurus
"Futabasaurus" is an informal name for a genus of theropod dinosaur from the Late Cretaceous of Japan, known only from a partial shin bone of ~ wide that was discovered in the Coniacian-age Ashizawa Formation of the Futaba Group; it was likely around when fully grown. It was first mentioned as "Futaba-ryu" by Hasegawa et al. (1987), and the name was coined by David Lambert in 1990 as a conversion from the Japanese nickname "Futaba-ryu", for an undescribed theropod. Dong Zhiming and coauthors briefly discussed the fossil shin bone it was based on that same year, publishing a photograph. They considered the bone to belong to an indeterminate tyrannosaurid. If the specimen is eventually described and named, it will require a different name, because the name Futabasaurus has since been used for a genus of plesiosaur.
G
Gadolosaurus
"Gadolosaurus" is an informal name given to PIN, no. 3458/5 an unnamed juvenile hadrosauroid dinosaur specimen from the Bayan Shireh Formation of Baishan Tsav, Mongolia. The name "Gadolosaurus" was first used in a 1979 book by Japanese paleontologist Tsunemasa Saito, in a caption for a photo of the specimen. This specimen represents an individual that was only about a meter long (39 inches). The specimen was part of a Soviet exhibition of fossils in Japan. Apparently, the name comes from a Japanese phonetic translation of the Cyrillic word gadrosavr, or hadrosaur, and was never meant by the Russians to establish a new generic name.
Despite the only name ever applied to it being merely a mistranslation of gadrosavr, this specimen has appeared in many popular dinosaur books, with varying identifications. Donald F. Glut in 1982 reported it as either an iguanodont or hadrosaur, with no crest or boot on the ischium (the lack of which are both characteristics of the crested lambeosaurine duckbills), and suggested it could be the juvenile of a previously named genus like Tanius or Shantungosaurus. David Lambert in 1983 classified it as an iguanodont, but changed his mind by 1990, when it was listed as a synonym of Arstanosaurus without comment. What may be the same animal is mentioned but not named by David B. Norman and Hans-Dieter Sues in a 2000 book on Mesozoic reptiles from Mongolia and the former USSR; this material, from the Soviet-Mongolian expeditions of the 1970s, had been listed as Arstanosaurus in the Russian Academy of Sciences, and was found in the Cenomanian-age Bayan Shireh Formation of Baishin Tsav.
Averianov, Lopatin, and Tsogtbaatar in 2022 provided a preliminary description of this specimen and its taxonomic position, finding that the specimen may represent a juvenile of a novel taxon that was closely related to but more derived than the contemporary hadrosauroid Gobihadros.
Gallimimus mongoliensis
"Gallimimus mongoliensis" is an informal name Rinchen Barsbold used for a nearly complete skeleton (IGM 100/14) known from the Bayan Shireh Formation, but since it differs from Gallimimus in some details, Yoshitsugu Kobayashi and Barsbold proposed in 2006 that it probably belongs to a different genus. It was recently included in a phylogenetic analysis, which recovered it as closely related to Tototlmimus.
Gspsaurus
"Gspsaurus" (a nomen manuscriptum) is a titanosaurian sauropod dinosaur from the Late Cretaceous Vitakri Member of the Pab Formation of Sulaiman Basin of Pakistan. It has been suggested to be synonymous with the also invalid taxon "Maojandino", also proposed by Malkani. The intended holotype, MSM-79-19 and MSM-80-19, consisting of parts of the skull, including a rostrum, was discovered in 2001, and parts of the holotype were initially referred to "Marisaurus jeffi".
Grusimimus
"Grusimimus" (or "Tsurumimus") is an informal name for an undescribed genus of ornithomimid from the Early Cretaceous (Hauterivian–Barremian) aged Shinekhudag Formation of Mongolia. Known from a skeleton including all regions except the skull, "Grusimimus" was given an invalid name in 1997 by Rinchen Barsbold, who also suggested the species name "tsuru". The specimen (GIN 960910KD) was found in 1996 and examined by Barsbold before he suggested the informal name, a nomen nudum. An abstract and poster were presented on the taxon by Kobayashi & Barsbold in 2002, and the former published a thesis paper on the specimen (referred to as "Ornithomimosauria indet.") which found the taxon to be close to Harpymimus phylogenetically but possible more derived. A recent phylogenetic analysis recovered "Grusimimus" closely related to Beishanlong and Garudimimus.
H
Hanwulosaurus
"Hanwulosaurus" is the informal name given to an as-yet undescribed genus of dinosaur from the Late Cretaceous. It was an ankylosaur around long, which is long for an ankylosaur. Its fossils were found in Inner Mongolia, China. Much of a skeleton, including a complete skull, vertebrae, ribs, a scapula, an ulna, femora, bones from the shin, and armor, was discovered; this may be the most complete ankylosaurian skeleton yet found in Asia, according to early reports. Zhao Xijin, who has studied it, suggests that it may belong to its own subgroup within the Ankylosauria. The name first surfaced in news reports in 2001.
Haute Moulouya Sauropod
The "Haute Moulouya Sauropod", also known as NHMUK PV R36834, consisted originally of two complete cervical vertebrae recovered from the Lower Jurassic sediments of the Haute Moulouya Basin, central Morocco. This material was initially identified as belonging to an early member of Eusauropoda, if so, the oldest member of the group. Additional material was previously recovered, SNSB-BSPG 2014 I 106 that consists of dorsal vertebrae and a pubis fragment. A recent revision suggest both specimens belong to the same taxon, that likely comes from a higher stratigraphic level (Likely Late Pliensbachian) and that represents a valid more basal taxon, related with Amygdalodon. Tought other analisis still recover it alternatively as an Eusauropod, in a polytomy with Barapasaurus.
Heilongjiangosaurus
"Heilongjiangosaurus" (meaning "Heilongjiang lizard") is the informal name given to an as-yet undescribed genus of duckbilled dinosaur from the Late Cretaceous. It possibly was a lambeosaurine, and may in fact be the same animal as Charonosaurus. The fossils were found in Maastrichtian-age rocks in Heilongjiang, China. As a nomen nudum, it is unclear what material it was intended to be based on, but might be connected to the nomen nudum "Mandschurosaurus" jiainensis, informally named in a 1983 publication.
The "type species" is "H. jiayinensis", and it was coined in 2001 in a faunal list by Li and Jin.
Hironosaurus
"Hironosaurus" (meaning "Hirono lizard") is the informal name given to an as-yet undescribed genus of dinosaur from the Late Cretaceous. Found in Hirono, Fukushima, Japan, it was probably a type of hadrosaur, although no subfamily identification has been made. The fossils are quite fragmentary, and consist of teeth and a vertebra, possibly from the tail. Since the fossils have never been fully described in a scientific paper, "Hironosaurus" is considered a nomen nudum. It was first mentioned by Hisa in an obscure 1988 publication and was later (1990) brought to a wider audience by David Lambert. Dong Zhiming, Y. Hasegawa, and Y. Azuma regarded the material as belonging to a hadrosaurid, but lacking any characteristics to allow more precise identification (thus indeterminate).
Hisanohamasaurus
"Hisanohamasaurus" (meaning "Hisano-hama lizard") is the informal name given to an as yet undescribed genus of dinosaur from the Late Cretaceous. It is a nomen nudum known only from teeth that first appeared in a general-audience dinosaur book by David Lambert in 1990. Although initially identified a diplodocid, it later re-identified as a nemegtosaurid similar to Nemegtosaurus. As its name suggests, its fossils were found in Japan. The location is part of Iwaki, Fukushima.
I
Ikqaumishan
"Ikqaumishan" is an informal genus of titanosaurian dinosaurs from the Late Cretaceous (Maastrichtian) Vitakri Formation of Pakistan described by Malkani (2023) in Scientific Research Publishing, a known predatory publisher. The assigned fossil material includes multiple humeri. Caudal vertebrae and osteoderms found nearby may also be referrable to "Ikqaumishan". The intended type species is "Ikqaumishan smqureshi."
Imrankhanhero
"Imrankhanhero" is an informal genus of titanosaurian dinosaurs from the Late Cretaceous (Maastrichtian) Vitakri Formation of Pakistan described by Malkani (2023) in Scientific Research Publishing, a known predatory publisher. The assigned fossil material includes a humerus, a femur, fibulae, a tibia, and a metatarsal. Caudal vertebrae found nearby may also be referrable to "Imrankhanhero". The intended type species is "Imrankhanhero zilefatmi."
Imrankhanshaheen
"Imrankhanshaheen" is an informal genus of titanosaurian dinosaurs from the Late Cretaceous (Maastrichtian) Vitakri Formation of Pakistan described by Malkani (2024) in Scientific Research Publishing, a known predatory publisher. The proposed holotype includes a braincase, vertebrae, a humerus, ulnae, a radius, metacarpals, a tibia, fibulae, ribs, girdle bones, and osteoderms. The intended type species is "Imrankhanshaheen masoombushrai."
J
Jeholraptor
"Jeholraptor" is the informal replacement genus name given to the microraptorine Sinornithosaurus haoiana—resulting in the new combination "Jeholraptor" haoiana—by Gregory S. Paul in the third edition of The Princeton Field Guide to Dinosaurs in 2024. The S. haoiana fossil is known from the Early Cretaceous (Barremian) upper Yixian Formation of China. The specimen, which is nearly complete, is about long and was probably close to in weight. Paul suggested that, due to similarities in the quadratojugal, "Jeholraptor" may have been a close relative of Wulong.
Jiangjunmiaosaurus
"Jiangjunmiaosaurus" (meaning "temple of the general lizard") is an informal name created by an anonymous author in 1987 for a possible chimaera of Monolophosaurus and Sinraptor. Paul (1988) tentatively placed "Jiangjunmiaosaurus" within Allosauridae and commented on the nasal ridges and orbital horn combining to form low, rugose-surfaced crests, and mentioned that "other excellent bones" may also be referable to "Jiangjunmiaosaurus".
Jindipelta
"Jindipelta" (Lei et al., 2019; in press) is the currently informal name given to an ankylosaur from the Zhumapu Formation in China. It is known from a partial skeleton found in Cenomanian rocks and the intended type species is "J. zouyunensis". The name was first announced in the 2019 SVP abstract book, alongside the megalosauroid Yunyangosaurus.
Julieraptor
"Julieraptor" is the nickname of a dromaeosaurid fossil found in the Judith River Formation, Montana in 2002. Parts of the same skeleton were illegally excavated and nicknamed Sid Vicious in 2006, and the poacher responsible subsequently served jail time for the theft. Bob Bakker therefore also nicknamed the specimen "Kleptoraptor". The skeleton was arranged to be sold to Royal Ontario Museum. It is known from a skeleton consisting of an almost complete skeleton missing most of its skull, most tail vertebra, part of the femur, some spinal and neck vertebra, one claw but it has a well preserved braincase.
K
Kagasaurus
"Kagasaurus" (meaning "Kaga lizard") is the informal name given to an as yet undescribed genus of dinosaur from the Early Cretaceous. It was a theropod which lived in what is now Japan. The type species was named by Hisa in 1988, but is known from only two teeth. Since "Kagasaurus" has never been formally described, it is considered a nomen nudum. Unlike "Kitadanisaurus" and Katsuyamasaurus, it is unlikely that "Kagasaurus" is synonymous with Fukuiraptor, and may instead be a dromaeosaurid.
Katsuyamasaurus
"Katsuyamasaurus" is an informal name for a genus of intermediate theropod known from the Early Cretaceous (Barremian) of the Kitadani Formation, Japan. Known from a single middle caudal vertebra and an ulna, the taxon was informally called "Katsuyama-ryu", until Lambert (1990) made it into an invalid genus name, "Katsuyamasaurus". The caudal vertebra was suggested to belong to an ornithopod by Chure (2000), and Olshevsky (2000) suggested the material was a synonym of Fukuiraptor. However, the ulna differs from Fukuiraptor, and the large olecranon suggests the taxon falls outside Maniraptoriformes.
Khanazeem
"Khanazeem" is an informal genus of titanosaurian sauropod from the Late Cretaceous Vitakri Formation of Pakistan. The holotype is a partial skeleton and consists of a dentary with teeth, caudal vertebrae, femora, humeri, and tibiae. The intended type species is "Khanazeem saraikistani" and was first mentioned by Malkani (2022).
Khetranisaurus
"Khetranisaurus" (meaning "Khetran lizard", for the Khetran people of Pakistan) is an informal taxon of titanosaurian sauropod from the Late Cretaceous of Balochistan, western Pakistan (also spelled "Khateranisaurus" in some early reports). The proposed species is "K. barkhani", described by M. Sadiq Malkani in 2006, and it is based on a tail vertebra, found in the Maastrichtian-age Vitakri Member of the Pab Formation. It was assigned to "Pakisauridae" (used as a synonym of Titanosauridae), along with "Pakisaurus" and "Sulaimanisaurus". It was considered invalid by Wilson, Barrett and Carrano (2011).
Koreanosaurus
"Koreanosaurus" (meaning "Korean lizard") is the informal name given to an as-yet unnamed genus of dinosaur from the Early Cretaceous (Aptian-Albian). It was a possible dromaeosaur (or similar theropod) which was discovered in the Gugyedong Formation of South Korea, although at times it has been referred to the Tyrannosauridae, Hypsilophodontidae and Hadrosauridae. Based solely on DGBU-78(=DGBU-1978B), a femur, the name was coined by Kim in 1979, but by 1993 Kim decided that it was a species of Deinonychus, and created the informal name "D." "koreanensis". Kim et al. (2005) referred the specimen to Eumaniraptora based on a proximolateral ridge, shelf-like posterior trochanter, and absence of an accessory trochanter and mediodistal crest. The presence of a large fourth trochanter was noted to be similar to Adasaurus and Velociraptor.
Kunmingosaurus
"Kunmingosaurus" is an informally named primitive sauropod which lived during the Early Jurassic. Its fossils were found in Yunnan, China in 1954. The type and only species is "Kunmingosaurus wudingensis", invalidly coined by Zhao in 1985. It is known from fossils found in the Fengjiahe Formation (or the Lower Lufeng Series), including pelvic, hind limb, and vertebral material.
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Lancanjiangosaurus
"Lancanjiangosaurus" (alternative spelling "Lanchanjiangosaurus"; meaning "Lancangjiang lizard", named after the Lancangjiang River of China) is the informal name given to an as yet undescribed genus of sauropod dinosaur from the Middle Jurassic. The "type species", "L. cachuensis", was coined by Zhou in 1983, but remains a nomen nudum. It is known from the Dapuka Group of Tibet.
Lijiagousaurus
"Lijiagousaurus" (meaning "Lijiagou lizard") is the informal name given to an as yet undescribed genus of herbivorous iguanodontian dinosaur from the Late Cretaceous of what is now Sichuan, China. It has not been formally described yet, but the formal publication is forthcoming, from Chinese paleontologist Ouyang Hui. "Lijiagousaurus" was only briefly mentioned in the Chongqing Natural History Museum guidebook (2001) and is thus a nomen nudum.The holotype consists of hindlimb bones, a scapula, an ischium and other fragments.
Likhoelesaurus
"Likhoelesaurus" (meaning "Li Khole lizard") is the name given to an as yet undescribed genus of archosauriform, either a dinosaur or rauisuchian, from the Late Triassic of what is now South Africa. The name was coined by Ellenberger in 1970, and the "type species" is "Likhoelesaurus ingens". It is named after the town in Lesotho where the fossils were found. The only fossils recovered have been teeth, from the late Carnian–early Norian-age Lower Elliot Formation. Ellenberger (1972) regarded the genus as a giant carnosaur, and Kitching and Raath (1984) treated it as possibly referable to Basutodon. Knoll listed "Likhoelesaurus" as a rauisuchian, also he noted that could also be a rauisuchian.
Lopasaurus
"Lopasaurus" (meaning "Alberto Lopa's lizard") is the name given to an as yet undescribed genus of dromaeosaurid theropod, possibly belonging to Unenlagiinae due to its similarity to Buitreraptor, Neuquenraptor and Pamparaptor, from the Late Cretaceous (Maastrichtian)-aged Serra da Galga Formation in the Ponto 1 do Price site of Brazil. The intended holotype, a partial right metatarsus showing metatarsals II, III and IV, was discovered by Alberto Lopa during the 1950s but the fossil was lost shortly after the death of Llewellyn Ivor Price in 1980 and it has not been located since. "Lopasaurus" was briefly mentioned by Brum et al. in their description of Ypupiara lopai, where it was tentatively referred to Unenlagiinae. Brum et al. (2021) also did not refer "Lopasaurus" to Ypupiara, which was found in the same formation as "Lopasaurus".
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Magulodon
"Magulodon" is the name given to an as yet undescribed genus of dinosaur from the Early Cretaceous (Aptian to Albian stages, approximately 112 million years ago). It was a possible ornithischian, either an ornithopod or basal ceratopsian, which was discovered in the Arundel Formation of Maryland, United States. The type species, "Magulodon muirkirkensis", was coined by Kranz in 1996. It is a tooth taxon, based solely on a single tooth. Since it has not been formally described, it is also a nomen nudum. It was considered to be an indeterminate specimen in a paper which cited the intended type specimen but avoided using the name to prevent taxonomic clutter.
Maltaceratops
"Maltaceratops" is the informal name given to an as yet undescribed genus of centrosaurine ceratopsian from the Late Cretaceous (Campanian-aged) Judith River Formation of Montana. The proposed type species is "M. hammondorum", and the proposed holotype is a possible skull. It had been previously nicknamed the "Malta new taxon".
Mangahouanga
"Mangahouanga" (named after the stream of the same name), or the "Joan Wiffen's theropod" is an informal name given to the theropod discovered in the Tahora Formation, New Zealand by Joan Wiffen, who considered it to be a possible megalosaurid in 1975. The vertebra was described by Molnar 1981, and it was ruled as an indeterminate theropod in 2010 by Agnolin et al. The name "Mangahouanga" was coined by Molina-Pérez & Larramendi (2016) and no species name was given. They estimated it to reach up to long and weigh up to and is represented by of a single vertebra.
Maojandino
"Maojandino" is an informally named taxon of titanosaurid sauropod dinosaur from the Late Cretaceous Maastrichtian stage of Pakistan. The intended type species is "Maojandino alami."
Marisaurus
"Marisaurus" (meaning "Mari lizard", for the Mari tribe of Pakistan) is an informal taxon of titanosaurian sauropod from the Late Cretaceous of Balochistan, western Pakistan. The type species is "M. jeffi", described by Muhammad Sadiq Malkani in 2004, and it is based on tail vertebrae, found in the Maastrichtian-age Vitakri Member of the Pab Formation. Much additional material, including a partial skull, many vertebrae, and a few hindlimb bones, was referred to this genus. "Marisaurus" was assigned to "Balochisauridae" with "Sulaimanisaurus", although the family was used as a synonym of Saltasauridae. It was considered invalid by Wilson, Barrett and Carrano (2011).
Maroccanoraptor
"Maroccanoraptor" is an informal name suggested for a supposed unenlagiine theropod from the Kem Kem Formation of Morocco, however, it lacks the requirements to become a valid taxon, thus leaving it as a naked name. The intended type species is "M. elbegiensis", first described by Singer (2015) on the basis of a single coracoid. The fossil was later suggested to belong to a non-dinosaurian crocodyliform.
Megacervixosaurus
"Megacervixosaurus" (meaning "big neck lizard") is the informal name given to an as yet undescribed genus of herbivorous dinosaur from the Late Cretaceous Zonggo Formation of Tibet. It was a titanosaur sauropod which lived in what is now China The type species, "Megacervixosaurus tibetensis", was coined by Chinese paleontologist Zhao Xijin in 1983. "Megacervixosaurus" has never been formally described, and remains a nomen nudum.
Megapleurocoelus
"Megapleurocoelus" is an informally named sauropod belonging to Flagellicaudata, from the Kem Kem Formation of Morocco, however, it lacks the requirements to become a valid taxon, thus leaving it as a naked name. The intended type species is "M. menduckii", first described by Singer (2015) and the holotype is JP Cr376, a single centrum from a dorsal vertebra.
Microcephale
"Microcephale", also known as "Mycocephale", (meaning "tiny head") is the informal name of a genus of very small pachycephalosaurid dinosaur, otherwise known as the "North American dwarf species", which lived during the Late Cretaceous. Its fossils were found in the late Campanian-age Dinosaur Park Formation, in Alberta, Canada. Not much is known about this dinosaur, as it has not yet been fully described; it is therefore a nomen nudum. The fossils of "Microcephale", including tiny skull caps, were first mentioned by paleontologist Paul Sereno in 1997, in a list of pachycephalosaurids. These skull caps measure less than 5 cm (2 in) each. No potential species name was given.
Microdontosaurus
"Microdontosaurus" (meaning "tiny-toothed lizard") is the name given to an as yet undescribed genus of sauropod dinosaur from China. It was named from fossils from the Middle Jurassic-age Dapuka Group of Xinjiang. The intended type species is "M. dayensis." As with other informal names created by Zhao in 1985 or 1983, it has not been used since then, and may have been redescribed under another name.
Microvenator chagyabi
"Microvenator chagyabi" is the informal name given to an as yet undescribed species of theropod dinosaur, likely belonging to Coelurosauria, from the Early Cretaceous Lura Formation of Tibet, China. It was coined by Zhao (1985) and the proposed holotype consists of a specimen including teeth.
Mifunesaurus
"Mifunesaurus" (meaning 'Mifune lizard') is a nomen nudum given to an extinct non-avian non-maniraptoriform tetanuran theropod dinosaur from the Late Cretaceous (Cenomanian; ~96 Ma) Kabu Formation of Japan. The intended holotype, stored at the Mifune Dinosaur Museum, with the tooth on display, of "Mifunesaurus" consists only of a few bones, among which are a tibia, a phalanx, a metatarsus and a single tooth (tooth catalogued as YNUGI 10003; rest of the skeleton catalogued as MDM 341), discovered by N. & K. Wasada in 1979. The genus was informally coined by Hisa in 1985 and no epithet was given. The known tooth was too thick to be the tooth of a ceratosaurid, and too tall to belong to an abelisaurid, which means that "Mifunesaurus" was probably a megalosauroid or a carnosaur based on the shape of the known tooth.
Mitchell ornithopod
The "Mitchell ornithopod" is the informal nickname of an ornithopod dinosaur discovered near Mitchell, Oregon, being the first described dinosaur from Oregon but not the first discovered; a hadrosaurid sacrum was discovered in the Late Cretaceous (Campanian)-aged Cape Sebastian Sandstone near Cape Sebastian during the 1960s and excavated in 1994 by Dave Taylor, but the remains of the Cape Sebastian ornithopod were not prepared for peer review and described until 2019, merely weeks after the Mitchell ornithopod was described. The single known bone, F118B00, was a toe bone, specifically the third phalanx of the central digit of the right hindlimb foot, and was discovered by Gregory Retallack in 2015 while on an annual field trip with his students, in a layer of the Albian-aged Hudspeth Shale Formation; in 2021, Gloria Carr discovered another bone, this time a vertebra, that likely belonged to the same species of ornithopod. No excavation was required – the bone was found resting on the ground and Retallack immediately knew it was different from the various marine fossils scattered nearby. The bone was described in 2018 by Gregory Retallack, Jessica Theodor, Edward Davis, Samantha Hopkins and Paul Barrett. It was part of a bloated carcass swept out into the ocean, likely originating from Idaho, although further discoveries, such as Strommer (2021), dispute this claim and suggest it may have been deposited by a mudflow.
The bone was later compared to more complete remains of other ornithopods and the "Mitchell ornithopod" bone most closely matched those of hadrosaurs and iguanodonts, although it was likely a basal ornithopod. Rettalack believes that the bone belonged to a new genus, although there is not enough sufficient remains to base this claim on.
Moshisaurus
Hisa (1985) used "Moshisaurus" (or "Moshi-ryu") for the incomplete sauropod humerus NSM PV17656, from the Early Cretaceous Miyako Group of Japan. Dong et al. (1990) and Hasegawa et al. (1991) referred them to Mamenchisaurus, but Azuma & Tomida (1998) and Barrett et al. (2002) assigned them to Sauropoda indet.
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Newtonsaurus
"Newtonsaurus" is an informally named genus erected for the theropod dinosaur species Zanclodon cambrensis. The species is based on the specimen BMNH R2912, an external mold of a dentary, which was discovered in the Late Triassic (Rhaetian) aged beds of the Lilstock Formation near Bridgend, Wales in 1898 and described by Edwin Tulley Newton in 1899. The taxon was reassigned to ?Megalosaurus by Molnar in 1990, which was followed by Peter Galton in publications in 1998 and 2005. The species is considered to be a nomen dubium, as it has no diagnostic features, and is considered to be a coelophysoid grade theropod outside Averostra based on the low interdental plates and possession of only a single meckelian foramen. It has alternatively been suggested to possibly represent another indeterminate predatory archosaur.
The name "Newtonsaurus" was coined in 1999 by Stephan Pickering, in reference the describer. Paleontologists have avoided using the name "Newtonsaurus" since its appearance in 1999 in private publications, although "Zanclodon" cambrensis or Megalosaurus cambrensis have both been used for this taxon.
Ngexisaurus
"Ngexisaurus" is the informal name given to an as yet undescribed genus of theropod dinosaur, likely belonging to Avetheropoda, from the Middle Jurassic Dapuka Group of Tibet, China. The type species, "Ngexisaurus dapukaensis", was coined by Zhao in 1983. A synonym of "Ngexisaurus" coined by Zhao (1985) is "Megalosaurus" dapukaensis and Fossilworks lists "M." dapukaensis as a megalosaurid tetanuran separate from "Ngexisaurus" proper.
Nicksaurus
"Nicksaurus" is an informally named Titanosaurian sauropod dinosaur from the Late Cretaceous red muds of the Vitakri Formation of the Sulaiman Basin, Pakistan. The dinosaur shared a habitat with other sauropod dinosaurs including Khetranisaurus, Sulaimanisaurus, Pakisaurus, Gspsaurus, Saraikimasoom, and Maojandino.
The intended type species is "Nicksaurus razashahi" and was first used by Malkani (2019).
Nurosaurus
"Nurosaurus" (Nur-o-saw-rus, meaning "Nur lizard") is the informal name for a genus of sauropod dinosaur. It is known from a partial, large skeleton, that was presented as soon-to-be-described by Zhiming Dong in 1992, where he gave the proposed binomial "Nurosaurus qaganensis". It was discovered in the Qagannur Formation of Inner Mongolia, southeast of Erenhot. The deposit is younger than the Psittacosaurus-bearing Guyang Group, but is still Early Cretaceous. It was found alongside the plates and scapula of a stegosaur.
The foot of "Nurosaurus" is notable for a stress fracture present on the first of the fourth digit of the left foot, which was the first identified fracture of its kind, and have since been identified on the phalanges and metatarsals of Apatosaurus, Barosaurus, Brachiosaurus, Camarasaurus, and Diplodocus.
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Oharasisaurus
"Oharasisaurus" is the name given to an as yet undescribed genus of somphospondylian sauropod, possibly belonging to the Euhelopodidae, from the Early Cretaceous Kuwajima Formation (Facies III layer) of Japan. The name "Oharasisaurus" was coined by Larramendi & Molina Pérez (2020) and the holotype, a tooth, was first mentioned by Matsuoka (2000).
Orcomimus
"Orcomimus" (Pronounced or-coh-mEYEm-us) is the name given to an as yet undescribed genus of dinosaur from the Late Cretaceous period 66 million years ago. The dinosaur was an ornithomimid which lived in what is now South Dakota, in the United States. The type was coined by Michael Triebold in 1997, but has never been formally described and is currently a nomen nudum. "Orcomimus" was a bipedal theropod, but the dinosaur is known from only a pelvis and a hindlimb. "Orcomimus" is thought to be relatively advanced for other ornithomimids at the time, although this is hard to tell from the limited amount of specimens found of the dinosaur. It may be referable to one of the ornithomimosaur species currently known from the Hell Creek Formation, where the holotype of "Orcomimus" was found.
Oshanosaurus
"Oshanosaurus" (meaning "Oshan lizard") is the informal name given to an as yet undescribed genus of sauropod dinosaur from the Early Jurassic period of Yunnan, China. Its fossils were found in the Lower Lufeng Series. The intended "type species", "Oshanosaurus youngi", was coined by Zhao in 1985. It has sometimes been associated with heterodontosaurids, which appears to be due to the juxtaposition of a species of Dianchungosaurus (formerly thought to be a heterodontosaurid) in the text of Zhao (1985).
In 1971 Zhao Xijin discovered a dinosaur fossil at Dianchung in Eshan county, giving it the informal name "Oshanosaurus youngi". In their 2019 popular book Dinosaur Facts and Figures: The Theropods, Molina-Perez and Larramendi suggested that it belonged to the theropod Eshanosaurus, but without elaboration.
Osteoporosia
"Osteoporosia" is an informally named theropod, either belonging to Carcharodontosauridae or Megaraptora, from the Kem Kem Formation of Morocco, however, it lacks the requirements to become a valid taxon, thus leaving it as a naked name. The intended type species is "O. gigantea", first described by Singer (2015) and the holotype is JP Cr340, a tooth, with an indeterminate posterior or dorsal neural arch also known.
A 2019 theropod faunal list found "Osteoporosia" to be a possible synonym of Sauroniops pachytholus.
Otogosaurus
"Otogosaurus" is an informally named sauropod from Inner Mongolia, China. The supposed type species is "Otogosaurus sarulai". It is known from partial postcranial remains, including a tibia long and several footprints. It is named after Otog Banner in Inner Mongolia where it was discovered, and Sarula, the girl who discovered the fossils. Despite sometimes being presented as a valid taxon, sometimes accompanied by citations to Zhao (2004) or Zhao & Tan (2004), scholars have not been able to locate such a source, so it remains informal until a paper is discovered.
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Pakisaurus
"Pakisaurus" (meaning "Pakistan lizard") is an informal taxon of titanosaurian sauropod from the Late Cretaceous of Balochistan, western Pakistan, and also Gujarat, India. The proposed species is "P. balochistani", and it was named by M. Sadiq Malkani in 2006, based on isolated tail vertebrae found in the Maastrichtian-age Vitakri Member of the Pab Formation. In 2023, a femur discovered in the Lameta Formation of India was assigned to "Pakisaurus".
It was considered invalid by Wilson, Barrett and Carrano (2011) during their description of a Jainosaurus cf. septentrionalis skeleton.
"Anokhadino mirliaquati" was synonymised with "Pakisaurus balochistani" by Malkani (2019).
Paw Paw scuteling
The "Paw Paw scuteling" is the name used for a juvenile nodosaurid discovered in 1990 from the Paw Paw Formation of northern Fort Worth, Texas. It was discovered by John C. Maurice, the 12-year-old son of fossil collector John M. Maurice. The specimen consists of a partial skeleton including a third of the backbone, part of the skull, and both leg and arm elements. It is one of two or three nodosaurs known from the formation alongside Pawpawsaurus and Texasetes, and one of the very few known specimens of a baby nodosaur. Some phylogenetic analyses have recovered it as sister to Niobrarasaurus. Although taxonomically indeterminate due to its life stage and fragmentary nature, it is often used in phylogenetic analyses for determining the taxonomic affinity of other nodosaur genera.
Podischion
"Podischion" is an informal genus of hadrosaurid dinosaur known from a skeleton discovered in 1911 on the Red Deer River in Alberta by a crew led by Barnum Brown. The remains were tentatively named "Podischion", which was not mentioned in published literature until Dingus & Norell (2010). It is possible that the skeleton represents an individual of Hypacrosaurus.
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Qaikshaheen
"Qaikshaheen" is an informal genus of titanosaurian dinosaurs from the Late Cretaceous (Maastrichtian) Vitakri Formation of Pakistan described by Malkani (2023) in Scientific Research Publishing, a known predatory publisher. The proposed holotype specimen includes fragmentary cervical and dorsal vertebrae, partial pectoral and pelvic girdles, humeri, femora, a tibia, and fibulae. Other bones, including several vertebrae, ribs, a humerus, ulnae, metacarpals, metatarsals, a femur, and a partial pelvic girdle, were also referred. The intended type species is "Qaikshaheen masoomniazi."
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Ronaldoraptor
"Ronaldoraptor", also known as the "Mitrata" Oviraptorid, is an undescribed oviraptorid from Mongolia and has been listed as "Oviraptor sp." The name was first used by Luis Rey in 2003, in his book A Field Guide to Dinosaurs: The Essential Handbook for Travelers in the Mesozoic, where he drew an illustration, captioning it "Ronaldoraptor". "Ronaldoraptor" may have been closely related to Citipati osmolskae.
Rutellum
"Rutellum" is the pre-Linnaean name given to a dinosaur specimen from the Late Jurassic (Oxfordian)-aged Coralline Oolite Formation. It was a sauropod, possibly a cetiosaurid, which lived in what is now England. The specimen (OU 1352), called "Rutellum impicatum", was described in 1699 by Edward Lhuyd alongside specimen OU 1358, what is now believed to be a Megalosaurus tooth crown, and is notable as the earliest named entity that is recognizable as a dinosaur. It was based on a tooth collected from Caswell, near Witney, Oxfordshire.
Because "Rutellum impicatum" was named before 1758 (the official starting date for zoological nomenclature according to the ICZN), it is not considered a part of modern biological nomenclature.
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Sabinosaurus
"Sabinosaurus" or "Sabinosaurio" is a name used for PASAC-1, a partial skeleton of a hadrosaur that was discovered in the Sabinas Basin in Mexico in 2001. It was initially described as Kritosaurus sp. by Jim Kirkland and colleagues (2006), but considered an indeterminate saurolophine by Prieto-Márquez (2014). This skeleton is about 20% larger than other known specimens, around long, and with a distinctively curved ischium, and represents the largest known well-documented North American saurolophine. Unfortunately, the nasal bones are also incomplete in the skull remains from this material.
Saldamosaurus
"Saldamosaurus" is an informal genus of stegosaurid dinosaur known from a complete braincase discovered in the Early Cretaceous Saldam Formation of Siberia, Russia. The type species, "Saldamosaurus tuvensis", was named in 2014 but according to Galton and Carpenter (2016) it did not meet the requirements of the International Code of Zoological Nomenclature and is hence a nomen nudum.
Saltillomimus
"Saltillomimus" is an informal name for an ornithomimid theropod from the Late Cretaceous (late Campanian) of the Cerro del Pueblo Formation in Mexico. It is known from SEPCP 16/237, a partial tail, most of a hindlimb, and forelimb bones, discovered in 1998, and the possible juvenile specimen SEPCP 16/221, a partial leg and hip bone, that was given the name "Saltillomimus rapidus" by Martha Carolina Aguillón Martinez in 2010. A skeletal reconstruction was put on display in 2014 at the Museo del Desierto, which served to highlight its robust thighs and unusual hips that combine primitive and advanced features seen in ornithomimosaurs from both Asia and North America. Named in Martinez' 2010 thesis, the taxon name is an invalid nomen ex dissertatione.
Sanchusaurus
"Sanchusaurus" (meaning "Lizard from Sanchu") or "Sanchu-ryu" is an informal name for possible ornithomimosaur dinosaur from the Early Cretaceous period of Asia. It is only known by a partial tail vertebra, found in Nakasato, Japan. Dong (1990) considered it synonymous with Gallimimus but the large discrepancy in both age and location between the two species renders this opinion untenable. The genus has not been formally described and is considered a nomen nudum. It was first mentioned by Hisa in 1985. In 2006, it is shown that this animal is not fully grown, and characters of tail vertebra is not unique to that of ornithomimosaur.
Saraikimasoom
"Saraikimasoom" (meaning 'Innocent one') is an invalid species of titanosaur dinosaur from the Vitakri Formation in Pakistan. The type species, Saraikimasoom vitakri, was described by Sadiq Malkhani in 2015, in a paper describing multiple Pakistani dinosaurs, such as Gspsaurus, "Nicksaurus" and "Maojandino". Saraikimasoom is currently recognised as a nomen manuscriptum.
Saraikisaurus
"Saraikisaurus" (meaning "Saraiki lizard") is an invalid genus name proposed for a putative reptile found in the Late Cretaceous (Maastrichtian)-aged Vitakri Formation of Pakistan and possibly also the Lameta Formation of India. The intended type species is "Saraikisaurus minhui", known from the proposed holotype—a fragmentary dentary (GSP/MSM-157-16)—and a referred specimen—an incomplete vertebra (GSP/MSM-64-15). Malkani initially interpreted the dentary as belonging to a basal pterodactyloid and created the further monotypic family "Saraikisauridae" and subfamily "Saraikisaurinae" to house it. The name "Saraikisaurus" was first proposed by M. Sadiq Malkani in a 2013 conference. A later endeavor to describe it in 2015 was not peer-reviewed. In 2021, Malkani attempted to formally describe "Saraikisaurus" and other taxa in Scientific Research Publishing, a known predatory publisher. In 2024, he reinterpreted the specimen as instead belonging to a noasaurid theropod, redescribing it as a novel taxon in another unreviewed paper on ResearchGate. He assigned the fragmentary vertebra to this genus on the basis of compatible size and preservation styles, and apparent similarities to the corresponding bones in Laevisuchus.
Shake-N-Bake theropod
The "Shake-N-Bake theropod" is an undescribed species of coelophysoid from the Kayenta Formation, known from partial skeleton MCZ 8817 within the collection of Harvard Museum of Natural History.
Shansaraiki
"Shansaraiki" (meaning "respected Saraiki peoples") is an informal genus of theropod that was probably an abelisaur. The holotype was found in the Shalghara locality of the Late Cretaceous Vitakri Formation of Pakistan and consists of GSP/ MSM-140-3 (symphysis), GSP/MSM-5-3 (mid-ramus with partial teeth bases) and GSP/MSM-57-3 (dorsal vertebrae), although they may belong to separate specimens as they were found apart from each other. The intended type species is "Shansaraiki insafi" and was first mentioned by Malkani (2022).
Siamodracon
"Siamodracon" is an extinct genus of invalid stegosaurid dinosaur known from a single dorsal vertebra found in Thailand's Phu Kradung Formation. The type species, "Siamodracon altispinax", was named by Ulansky in 2014. According to Galton and Carpenter (2016) it did not meet the requirements of the International Code of Zoological Nomenclature. "Siamodracon" was the first thyreophoran dinosaur discovered in South East Asia.
Sidormimus
"Sidormimus" is an informal genus of noasaurid discovered in the Elrhaz Formation in Niger. It was discovered in 2000 by Chris Sidor and it was immediately described by Lyon on the Project Exploration website, with a photograph of the holotype. During the same year, on the National Geographic website, the same photograph of the holotype was labelled "Dogosaurus". It has also been referred to as the "Gadoufaoua noasaurid". In 2005, Sidor himself confirmed that "Sidormimus" was the Elrhaz noasaurid. "Sidormimus" has been mentioned by Paul Sereno three times. "Sidormimus" is known from a partial post cranial skeleton. Its neck and ribs were exposed when the holotype was discovered.
Sinopeltosaurus
"Sinopeltosaurus" is a dubious genus of extinct thyreophoran ornithischian dinosaur described by Roman Ulansky. The type and only species is "S. minimus" of the lower Jurassic Lufeng Formation of Yunnan China, based on an articulated set of ankle bones. The specimen is FMNH CUP 2338, and includes the distal tibia and fibula, distal tarsals, most metatarsals, and some phalanges. FMNH CUP 2338 was described in 2008 by Randall Irmis and Fabian Knoll, as one of the few definitive specimens of Ornithischia from the Early Jurassic based on features of the ankle and pes. In 2016, Peter Malcolm Galton and Kenneth Carpenter identified it as a nomen dubium, and listed it as Ornithischia indet., possible Thyreophora indet. Ulansky variously referred to it as "Sinopeltosaurus minimus" or "Sinopelta minima"; Galton and Carpenter, as the first revisers under ICZN, made the former official.
Skaladromeus
"Skaladromeus" or the "Kaiparowits ornithopod" is an ornithopod from the Kaiparowits Formation named in a 2012 thesis by Clint Boyd. The intended type species is "Skaladromeus goldenii".
Sousatitan
"Sousatitan" is the name given to an as yet undescribed genus of titanosaurian sauropod dinosaur from the Early Cretaceous-aged Rio Piranhas Formation of Brazil. The intended holotype consists of a left fibula, and "Sousatitan" was coined by Ghilardi et al. (2016).
Stegotitanus
"Stegotitanus" is the informal replacement genus name given to the stegosaur Stegosaurus ungulatus—resulting in the new combination "Stegotitanus" ungulatus—by Gregory S. Paul in the third edition of The Princeton Field Guide to Dinosaurs in 2024. Stegosaurus ungulatus fossils are known from the Late Jurassic (Kimmeridgian) upper Morrison Formation of Wyoming, US. "Stegotitanus" was one of the largest stegosaurs, at about long and in weight.
Suciasaurus
A fossil theropod (possibly a tyrannosaur) nicknamed "Suciasaurus rex" was discovered in 2012 at Sucia Island State Park in San Juan County of the U.S. State of Washington. It was the first dinosaur discovered in Washington state. The finding was announced when Burke Museum paleontologists published a discovery paper in PLoS ONE. Prompted by a petition from students at an elementary school at Parkland, near Tacoma, the Washington State Legislature introduced a bill in 2019 to make it the official state dinosaur. A renewed push came in 2021, though House Republicans, like Minority leader J. T. Wilcox, called it low priority versus the ongoing COVID-19 pandemic, and eventually the bill failed to pass, though in 2023 it passed.
Sugiyamasaurus
"Sugiyamasaurus" (meaning "Sugiyama lizard") is the informal name given to a few spatulate teeth belonging to a titanosauriform, possibly Fukuititan, which lived in Japan during the Early Cretaceous. The name was first printed by David Lambert in 1990 in the Dinosaur Data Book, and also appears in Lambert's Ultimate Dinosaur Book and in many on-line lists of dinosaurs. Since it has not been formally described, "Sugiyamasaurus" is a nomen nudum. Remains were found near Katsuyama City and were initially referred to Camarasauridae, but might belong to Fukutitan because they were unearthed in the same quarry as the Fukuititan material.
Sulaimanisaurus
"Sulaimanisaurus" (meaning "Sulaiman lizard", for the Sulaiman foldbelt) is an informal taxon of titanosaurian sauropod from the Late Cretaceous of Balochistan, western Pakistan (also spelled "Sulaimansaurus" in some early reports). The proposed species is "S. gingerichi", described by M. Sadiq Malkani in 2006, and it is based on seven tail vertebra, found in the Maastrichtian-age Vitakri Member of the Pab Formation. Four additional tail vertebrae have been assigned to it. It was considered to be related to "Pakisaurus" and "Khetranisaurus" in the family "Pakisauridae" (used as a synonym of Titanosauridae). It was considered invalid by Wilson, Barrett and Carrano (2011).
T
Teihivenator
"Teihivenator" ("strong hunter") is an improperly named taxon of tyrannosauroid coelurosaur from the Navesink Formation of New Jersey. It was suggested to contain the species, "T." macropus, originally classified as a species of Dryptosaurus (= "Laelaps", a name preoccupied by a mite). It was suggested as a separate genus in 2017 by Chan-gyu Yun. The name "Teihivenator" is invalid because the publication naming it is online-only, which means that a registration with ZooBank is required to be present in the article when published. However, the ZooBank registry was only added in after initial publication, meaning that it fails the requirement to be a validly published taxon.
In 2017, a preprint paper by Chase Brownstein concluded that the remains of L. macropus are a mixture of tyrannosauroid and ornithomimid elements with no distinguishing characteristics, rendering the species a chimera and a nomen dubium. In 2018, Brownstein stated that a tibia of L. macropus catalogued as specimen AMNH FARB 2550 represents a tyrannosauroid that probably was distinct from Dryptosaurus, but not sufficiently to base a taxon on.
That Which Cannot Be Named
"That Which Cannot Be Named" is the name given by Darren Naish to an undescribed associated skeleton of a small coelurosaur from the Wessex Formation of the Isle of Wight. The specimen is in private ownership and is currently inaccessible to researchers. It has been suggested that the specimen is possibly a tyrannosauroid.
Tiantaisaurus
"Tiantaisaurus", alternatively spelled "Tiantaiosaurus", is the name given to a specimen of therizinosaur from the Aptian age Laijia Formation of Zhejiang, China. According to correspondence through the Dinosaur Mailing List, the former name (from a 2012 study) was the one intended to be use for an official description. After being discovered in 2005, it was first mentioned named in an unpublished manuscript written in 2007. The given species was named "T. sifengensis". The specimen consists of an ischium, an astragalus, a tibia, a femur, an incomplete pubis and ilium, and a large number of vertebrae from across the body.
Tobasaurus
"Tobasaurus" (meaning "Toba City lizard") is the informal name given to an as yet undescribed genus of sauropod dinosaur from the Euhelopodidae from the Early Cretaceous (Hauterivian – Barremian-aged) Matsuo Group of Japan. The proposed holotype is a partial skeleton (mostly limb bones), and "Tobasaurus" grew up to when fully grown. It is the inspiration for the Vivosaur "Toba" in the video game Fossil Fighters.
Tonouchisaurus
"Tonouchisaurus" (meaning "Tonouchi lizard") is the informal name given to an as yet undescribed genus of coelurosaurian dinosaur from the Early Cretaceous Period of Mongolia. The suggested "type species", "Tonouchisaurus mongoliensis", was first informally mentioned in a Japanese news article. It was notably small: less than in length. The specimen informally dubbed "Tonouchisaurus mongoliensis" is based on limb material, and the manual and pedal remains were initially reported to incorporate a complete didactyl manus and complete pes, and Rinchen Barsbold therefore initially interpreted "Tonouchisaurus" as a tyrannosauroid, but he later noted that the manus is actually tridactyl and that the pes has a sub-arcometatarsalian condition.
U
Ubirajara
"Ubirajara" (meaning "Lord of the Spear") is an informal genus of compsognathid theropod known from the Early Cretaceous Crato Formation of Brazil; it was discovered in 1995 and was named in 2020 in an "In Press" article that was later withdrawn due to the specimen having been illegally smuggled from Brazil to Germany. It is considered a nomen manuscriptum.
Utetitan
"Utetitan" is the informal name given to specimens of the titanosaur Alamosaurus from the Late Cretaceous (Maastrichtian) lower North Horn Formation of Utah US, by Gregory S. Paul in the third edition of The Princeton Field Guide to Dinosaurs in 2024. Other titanosaurian bones from the upper Black Peaks Formation or Texas, US, may also be referrable to this taxon. "Utetitan" was reportedly about long and in weight. The intended type species is "Utetitan zellaguymondeweyae."
V
Vectensia
In 1982 Justin Delair informally named the genus "Vectensia" based on specimen GH 981.45, an armour plate. Like the holotype of Polacanthus it was found at Barnes High, but reportedly in an older layer, of the Lower Wessex Formation. Blows in 1987 tentatively referred it to Polacanthus.
Vitakridrinda
"Vitakridrinda" is a genus of abelisaurid theropod dinosaur from the Late Cretaceous of Balochistan, western Pakistan. The intended type species is "V. sulaimani". The discovery was made (along with other dinosaur specimens) near Vitariki by a team of palaeontologists from the Geological Survey of Pakistan, in rocks from the Maastrichtian-age Vitakri Member of the Pab Formation. Informally named in an abstract by M.S. Malkani in 2004 (to which Malkani [2006] attributes the name), it is based on partial remains including two thigh bones, and a tooth. A partial snout and braincase were originally referred to the holotype, and additional vertebrae may also belong to this genus. However, the snout was later reclassified as a new genus of mesoeucrocodylian, Induszalim, while the braincase was later referred to Gspsaurus. Thomas Holtz gave a possible length of 6 meters (19.7 feet).
Vitakrisaurus
"Vitakrisaurus" is a genus of noasaurid theropod dinosaurs represented by only one known species, "Vitakrisaurus saraiki", which is the intended type species. It lived in the late Cretaceous period, approximately 70 million years ago, during the Maastrichtian, in what is today the Indian subcontinent. Its fossils were found in Pakistan's Vitakri Formation. The holotype specimen, MSM-303-2 is a right foot with a seemingly tridactyl form and robust phalanges. It may belong to Noasauridae due to similarities with the foot of Velocisaurus, although inconsistencies within its brief description and a lack of comparison with other theropods within the article makes formal classification difficult. The generic name references the Vitakri Member of the Pab Formation and combines this with the Greek suffix "saurus", meaning "reptile". The specific name honours the Saraiki people, who primarily live in southern Pakistan. However, like most dinosaur taxa named by M. Sadiq Malkani, it is probably a nomen nudum. Some authors consider "Vitakrisaurus" to be the same animal as "Vitakridrinda".
W
White Rock spinosaurid
"White Rock spinosaurid" is the nickname of a giant spinosaur from the Vectis Formation of the Isle of Wight described in 2022. Its remains are so fragmentary that the describers refrained from naming it, but considered the name "Vectispinus". With vertebrae comparable in dimensions to Spinosaurus, it was likely among the largest theropods with a length exceeding .
X
Xinghesaurus
"Xinghesaurus" was the name given to a species of sauropod dinosaur, possibly a titanosauriform, in 2009, in the guidebook for the dinosaur expo "Miracle of Deserts", written by Hasegawa et al. No species name was given for the genus. Based on the skeletal mount, "Xinghesaurus" was likely around long and weighed around .
Y
Yibinosaurus
"Yibinosaurus" (meaning "Yibin lizard") is the informal name given to an as yet undescribed genus of herbivorous dinosaur from the Early Jurassic. It was a sauropod which lived in what is now Sichuan, China. The suggested "type species", "Yibinosaurus zhoui", is briefly mentioned in the Chongqing Natural History Museum guidebook (2001) as under description by Chinese paleontologist Ouyang Hui. It was coined as a nomen ex dissertationae by Ouyang (2003), and is based on a specimen referred to Gongxianosaurus sp. nov. by Luo and Wang (1999).
Yuanmouraptor
"Yuanmouraptor" is an informally named carnosaur from Yuanmou County, China. It lived during the Middle Jurassic, around 174 and 163 million years ago, and it is known from ZLJ0115, which is a complete, articulated skull on display at an unknown Chinese museum (possibly the Lufeng Dinosaur Museum), alongside a reconstructed skeleton of "Yuanmouraptor". "Yuanmouraptor" was briefly mentioned in a 2014 guide book, and Hendrickx et al. (2019) classify it as a metriacanthosaurid.
Yunxianosaurus
"Yunxianosaurus" is the provisional name for a genus of titanosaurian dinosaurs from the Late Cretaceous of what is now Hubei, China. The type species, "Yunxianosaurus hubeinensis", was proposed by Chinese paleontologist Li Zhengqi in 2001. The fossils of "Yunxianosaurus" were found near the Nanyang Prefecture. Li stated that the name "Yunxianosaurus" was a temporary label for ease of description, but that further field work and study of the fossils would be required before the genus could be given an official name.
Z
Zamyn Khondt oviraptorid
Zamyn Khondt oviraptorid is a nickname for oviraptorid specimen IGM or GIN 100/42. Since the type skull of Oviraptor is so poorly preserved and crushed, the skull of IGM 100/42 has become the quintessential depiction of that dinosaur, even appearing in scientific papers with the label Oviraptor philoceratops. However, this distinctive-looking, tall-crested species has more features of the skull in common with Citipati than it does with Oviraptor and it may represent a second species of Citipati or possibly an entirely new genus, pending further study.
See also
List of dinosaur genera
References
External links
Theropod Database Blog post clarifying sauropod nomina nuda from Zhao (1985)
Lists of prehistoric reptiles
Dinosaur-related lists
Lists of prehistoric animal genera (alphabetic)
Nomina nuda | List of informally named dinosaurs | [
"Biology"
] | 20,460 | [
"Biological hypotheses",
"Nomina nuda",
"Controversial taxa"
] |
57,927,139 | https://en.wikipedia.org/wiki/C27H44O8 | {{DISPLAYTITLE:C27H44O8}}
The molecular formula C27H44O8 (molar mass: 496.63 g/mol, exact mass: 496.3036 u) may refer to:
Pregnanediol glucuronide
Turkesterone | C27H44O8 | [
"Chemistry"
] | 65 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
57,927,962 | https://en.wikipedia.org/wiki/NGC%201266 | NGC 1266 is a lenticular galaxy in the constellation Eridanus. Although not currently starbursting, it has undergone a period of intense star formation in the recent past, ceasing only ≈500 Myr ago. The galaxy is host to an obscured active galactic nucleus.
A massive molecular outflow, with 2.4 × 107 M of hydrogen, is present from the nucleus of the galaxy, at a rate of 110 M yr−1. Less than 2% of the gas (2 M yr−1) is escaping the galaxy. Momentum coupling to the jet of the AGN is likely driving the outflow.
The current observed star-formation rate (SFR) of ~0.87 M yr−1 is significantly lower than expected for a galaxy of its properties, suppressed by a factor of 50 to 150. Authors have put forth several hypotheses to explain these observations. The most likely scenario is that the AGN-driven molecular outflow is injecting turbulence into the nuclear regions, preventing gravitational collapse of molecular clouds. NGC 1266 is the first known intermediate-mass galaxy to show AGN-driven suppression of star formation.
Two hypotheses exist to explain NGC 1266's nuclear activity and excessive far-IR emission. Either a heavily obscured ultracompact starburst is present in the nuclear regions, or a powerful buried AGN is present, beyond what has been inferred from other observations. Neither scenario is without problems. The black hole at the center of the galaxy is likely growing according to the M–sigma relation, and eventually the outflow will result in the removal of the majority of the gas from the nucleus.
References
External links
Lenticular galaxies
Active galaxies
Eridanus (constellation)
1266
12131 | NGC 1266 | [
"Astronomy"
] | 362 | [
"Eridanus (constellation)",
"Constellations"
] |
57,928,969 | https://en.wikipedia.org/wiki/Peziza%20halophila | Peziza halophila (now Daleomyces halophilus) is an ascomycete fungus in the family Pezizaceae, described as new to science in 2017. It was originally described in genus Peziza by Crous and colleagues in 2017, but in 2020 was transferred to the genus Deleomyces by Van Vooren, based on molecular data.
It is found on coastal dunes and halophytic wetlands on the Mediterranean island of Cyprus.
References
External links
On Species Fungorum
On Ascomycete.org
Pezizaceae
Fungi described in 2017
Fungus species | Peziza halophila | [
"Biology"
] | 122 | [
"Fungi",
"Fungus species"
] |
57,929,043 | https://en.wikipedia.org/wiki/Pseudoverpa | Pseudoverpa is a newly erected genus of post-fire ascomycete fungi in the family Discinaceae. It is monotypic, being represented by the single species Pseudoverpa anthracobia which was described as new to science in 2018 from recently burned forests on the island of Cyprus.
This fungus can resemble a Verpa species in the field because of its smooth, hollow and distinctly elongated stipe, which is attached to the pileus only at the apex. Its cerebriform (brain-like) pileus, brown-pigmented paraphyses and biguttulate cyanophilic spores, are all typical gyromitroid features, however.
Because of its carbonicolous ecology and isolated phylogenetic position within the genus Gyromitra, G. anthracobia was transferred to the new genus Pseudoverpa in 2023.
References
Fungi described in 2018
Discinaceae
Fungi of Europe
Fungus species | Pseudoverpa | [
"Biology"
] | 193 | [
"Fungi",
"Fungus species"
] |
57,929,243 | https://en.wikipedia.org/wiki/Hygrophorus%20meridionalis | Hygrophorus meridionalis is a species of basidiomycete fungus in the family Hygrophoraceae. Described as new to science in 2018, this waxcap is found in abundance on the island of Cyprus and southern Greece, where it grows in association with Pinus brutia and Pinus halepensis on calcareous substrates.
References
fungi described in 2018
fungus species
meridionalis | Hygrophorus meridionalis | [
"Biology"
] | 90 | [
"Fungi",
"Fungus species"
] |
57,932,194 | https://en.wikipedia.org/wiki/Semantic%20decomposition%20%28natural%20language%20processing%29 | A semantic decomposition is an algorithm that breaks down the meanings of phrases or concepts into less complex concepts. The result of a semantic decomposition is a representation of meaning. This representation can be used for tasks, such as those related to artificial intelligence or machine learning. Semantic decomposition is common in natural language processing applications.
The basic idea of a semantic decomposition is taken from the learning skills of adult humans, where words are explained using other words. It is based on Meaning-text theory. Meaning-text theory is used as a theoretical linguistic framework to describe the meaning of concepts with other concepts.
Background
Given that an AI does not inherently have language, it is unable to think about the meanings behind the words of a language. An artificial notion of meaning needs to be created for a strong AI to emerge.
Creating an artificial representation of meaning requires the analysis of what meaning is. Many terms are associated with meaning, including semantics, pragmatics, knowledge and understanding or word sense. Each term describes a particular aspect of meaning, and contributes to a multitude of theories explaining what meaning is. These theories need to be analyzed further to develop an artificial notion of meaning best fit for our current state of knowledge.
Graph representations
Representing meaning as a graph is one of the two ways that both an AI cognition and a linguistic researcher think about meaning (connectionist view). Logicians utilize a formal representation of meaning to build upon the idea of symbolic representation, whereas description logics describe languages and the meaning of symbols. This contention between 'neat' and 'scruffy' techniques has been discussed since the 1970s.
Research has so far identified semantic measures and with that word-sense disambiguation (WSD) - the differentiation of meaning of words - as the main problem of language understanding. As an AI-complete environment, WSD is a core problem of natural language understanding. AI approaches that use knowledge-given reasoning creates a notion of meaning combining the state of the art knowledge of natural meaning with the symbolic and connectionist formalization of meaning for AI. The abstract approach is shown in Figure. First, a connectionist knowledge representation is created as a semantic network consisting of concepts and their relations to serve as the basis for the representation of meaning.
This graph is built out of different knowledge sources like WordNet, Wiktionary, and BabelNET. The graph is created by lexical decomposition that recursively breaks each concept semantically down into a set of semantic primes. The primes are taken from the theory of Natural Semantic Metalanguage, which has been analyzed for usefulness in formal languages. Upon this graph marker passing is used to create the dynamic part of meaning representing thoughts. The marker passing algorithm, where symbolic information is passed along relations form one concept to another, uses node and edge interpretation to guide its markers. The node and edge interpretation model is the symbolic influence of certain concepts.
Future work uses the created representation of meaning to build heuristics and evaluate them through capability matching and agent planning, chatbots or other applications of natural language understanding.
See also
Latent Semantic Analysis
Lexical semantics
Principle of compositionality
References
Natural language processing
Semantics | Semantic decomposition (natural language processing) | [
"Technology"
] | 637 | [
"Natural language processing",
"Natural language and computing"
] |
57,933,020 | https://en.wikipedia.org/wiki/Ribenboim%20Prize | The Ribenboim Prize, named in honour of Paulo Ribenboim, is awarded by the Canadian Number Theory Association for distinguished research in number theory by a mathematician who is Canadian or has close connections to Canadian mathematics. Normally the winner will have received their Ph.D. in the last 12 years. The winner is expected to give a plenary talk at the award ceremony.
Due to the COVID-19 pandemic, the 2020, 2022, and 2024 Ribenboim Prizes were all awarded in 2024.
Winners
See also
List of mathematics awards
References
Mathematics awards
Canadian awards
Awards established in 1999
.
1999 establishments in Canada | Ribenboim Prize | [
"Mathematics",
"Technology"
] | 132 | [
"Science and technology awards",
"Discrete mathematics",
"Number theory",
"Mathematics awards"
] |
57,933,943 | https://en.wikipedia.org/wiki/Exapunks | Exapunks is a programming game developed by Zachtronics. It was released into early access on August 9, 2018, and fully released on October 22, 2018.
Gameplay
Exapunks takes place in an alternate timeline in the year 1997. The fictional world of Exapunks is heavily computerized, and a disease called "the phage" is ravaging the population, turning the bodies of those affected into computerized components. The player takes on the role of Moss, a hacker who breaks into computer systems in order to afford a $700/day drug to slow the progress of his phage affliction. His hacking missions are given to him by a mysterious artificial intelligence known as EMBER-2.
Each mission takes place inside a network of interconnected and specialized computer systems. Using programmable software agents called EXAs, the player must accomplish each given task by writing computer code to cleverly manipulate the data stored on the network's systems. The EXAs' instruction set features a few simple opcodes for movement, data processing, network messaging, and interfacing with files and registers. Due to their limited memory capacity, these tasks often require several agents working together in a highly coordinated fashion. EXA units also have the ability to replicate themselves inside the network. Typical missions include retrieving data from secured storage systems, hacking into company databases, and causing an automated teller machine to dispense free cash. Some puzzles also require the player to hack Moss's body to maintain his health. Some puzzles challenge the player to hacker battles, where they must pit their EXAs against an opponent's agents, for example altering a television station's program to broadcast Moss' content instead.
Players are generally free to write code for EXAs with as many EXAs as necessary, those are often limited by the number of opcodes that can be used. The player's solution must satisfy 100 different case scenarios iterating on the same problem. When the player demonstrates a successful solution, the game records how many cycles the solution took, the size of their code across all EXAs, and the number of movement and kill commands executed by the solution. These are tracked against other players' scores via histograms and friends' scoreboards, allowing players to try to optimize their solutions. Instructions for EXAs as well as additional useful information for some of the simulated systems are provided by issues of "Trash World News", a fictional zine; players can view these issues digitally, print them out, or buy a physical copy from Zachtronics. After completing a number of puzzles, the player gains access to both a puzzle editor to make new puzzles that can be uploaded to the Steam Workshop, as well as access to an in-game handheld game console, called Redshift, and program games for it. A free Redshift player was released by Zachtronics allowing any player, even those who had not purchased Exapunks, to play other players' Redshift creations. There is also a simple solitaire game and a tile-matching game unlocked through progression of the main story.
Development
Zach Barth, the founder of Zachtronics, was inspired to create Exapunks after reading about the Stuxnet viruses that had impacted a nuclear facility in Iran in 2010. Barth said that Stuxnet "sparked the idea of these malicious programs that are designed to unfold like origami into a specific network and manipulate it in some way". He developed Exapunkss lore on the cyberspace culture envisioned by William Gibson, though with more focus on the "punk" side of the 1980s and 1990s - small-time hackers fighting against large corporations. He also took inspiration from 2600: The Hacker Quarterly and attended various DEF CON events, while the game's writer, Matthew Burns, also considered cyberculture works like Wired, Transmetropolitan and Tom Clancy's Net Force Explorers influential. Barth also considered how films like Hackers made the hacking culture cool.
In terms of developing the EXA's opcodes, Barth borrowed concepts common to many real operating systems like Unix for file operations and links, and envisioned the EXAs as elements of the Magic Cap metaphor for computing systems.
Zachtronics announced Exapunks on July 18, 2018; the studio said it would follow a similar release approach they had done for previous games Shenzhen I/O and Opus Magnum by using an early access period for a nearly feature-complete game to gain and implement feedback from players before releasing the final game. The Early Access was to start August 21, 2018, but Zachtronics released the game earlier on August 9, 2018. The full version of Exapunks out of Early Access was released on October 22, 2018.
Reception
Initial reception of the game was positive. Rock Paper Shotgun included Exapunks on its list of "10 Best Hacking Coding and Computing Games", calling it "...an accurate portrayal of the decade (the 90's)." while Jeff Gerstmann of Giant Bomb said "It's awesome."
References
External links
2018 video games
Alternate history video games
Cyberpunk video games
Early access video games
Indie games
Linux games
MacOS games
Programming games
Single-player video games
Video games about artificial intelligence
Video games about computing
Video games about virtual reality
Video games developed in the United States
Video games set in 1997
Video games set in San Francisco
Windows games
Zachtronics games | Exapunks | [
"Technology"
] | 1,115 | [
"Works about computing",
"Video games about computing"
] |
57,934,418 | https://en.wikipedia.org/wiki/Direct%20Fusion%20Drive | Direct Fusion Drive (DFD) is a conceptual, low radioactivity, nuclear-fusion rocket engine, designed to produce both thrust and electric power, suitable for interplanetary spacecraft. The concept is based on the Princeton field-reversed configuration reactor, invented in 2002 by Samuel A. Cohen. It is being modeled and experimentally tested at Princeton Plasma Physics Laboratory, a U.S. Department of Energy facility, as well as modeled and evaluated by Princeton Satellite Systems (PSS). As of 2018, a direct fusion drive project driven by NASA is said to have entered its simulation phase, presented as the second phase of the concept's evolution.
Principle
The Direct Fusion Drive (DFD) is a theoretical spacecraft propulsion system that derives its name from its unique capability to generate thrust directly from nuclear fusion, bypassing the need for an intermediate electricity-generating process. Using a magnetic confinement and heating mechanism, the DFD is powered by a blend of helium-3 (3He) and deuterium (D or 2H), resulting in a propulsion system characterized by high specific power, variable thrust, specific impulse, and minimal radiation emissions of spacecraft propulsion system.
In the DFD, plasma, a collection of electrically charged particles that includes electrons and ions, fuse together at high temperatures (100 keV), releasing enormous amounts of energy. The plasma is confined in a torus-like magnetic field inside of a linear solenoidal coil and is heated by a rotating magnetic field to relevant fusion temperatures. Bremsstrahlung and synchrotron radiation emitted from the plasma are captured and converted to electricity for communications, spacecraft station-keeping, and maintaining the plasma's temperature. This design uses a specially shaped radio frequency (RF) "antenna" to heat the plasma. The design includes a rechargeable battery or a deuterium-oxygen auxiliary power unit to startup or restart the unit.
The captured radiated energy heats a He-Xe fluid that flows outside the plasma to in a boron-containing structure. That energy is put through a closed-loop Brayton cycle generator to transform it into electricity for use in energizing the coils, powering the RF heater, charging the battery, communications, and station-keeping functions.
Thrust generation
Adding propellant to the edge plasma flow results in a variable thrust and specific impulse when channeled and accelerated through a magnetic nozzle; this flow of momentum past the nozzle is predominantly carried by the ions as they expand through the magnetic nozzle and beyond, and thus, function as an ion thruster.
Development
The construction of the experimental research device and most of its early operations were funded by the U.S. Department of Energy. The recent studies—Phase I and Phase II—were funded by the NASA Institute for Advanced Concepts (NIAC) program. A series of articles on the concept were published between 2001 and 2008; the first experimental results were reported in 2007. Numerous studies of spacecraft missions (Phase I) were published, beginning in 2012. In 2017 Princeton Satellite Systems reported that "Studies of electron heating with this method have surpassed theoretical predictions, and experiments to measure ion heating in the second-generation machine are ongoing."
As of 2018, the concept has moved to Phase II, a simulation phase. The full-size unit would measure approximately 2 m in diameter and 10 m in length. PSS reported that electron heating in PFRC-2 surpassed theoretical predictions, reaching 500 eV with pulse lengths of 300 ms. Ion heating experiments are ongoing as of 2020.
Stephanie Thomas is vice president of Princeton Satellite Systems and the principal investigator for the Direct Fusion Drive.
Projected performance
Princeton Satellite Systems estimate that the Direct Fusion Drive may be capable of producing between 5–10 Newtons thrust per each MW of generated fusion power, with a specific impulse (Isp) of about 10,000 seconds and 200 kW available as electrical power. Approximately 35% of the fusion power goes to thrust, 30% to electric power, 25% lost to heat, and 10% is recirculated for the RF heating.
The company's modeling shows that this technology could propel a spacecraft with a mass of about to Pluto in four years, enabling deep space missions. DFD generates extra power so it may provide approximately 2 MW of power to the payloads upon arrival. This allows more options for instrument selection and laser/optical communications, and could even transfer up to 50 KW of power from the orbiter to the lander through a laser beam operating at 1080 nm wavelength.
Princeton Satellite Systems says that this technology can expand the scientific capability of planetary missions. This power/propulsion technology has been suggested to be used on a Pluto orbiter and lander mission, or as integration on the Orion spacecraft to transport a crewed mission to Mars in a faster time frame (4 months instead of 9 with current technology). DFD is projected to deliver scientific payloads to Titan in 2.6 years.
See also
Fusion Industry Association
References
External links
Princeton Satellite Systems Inc Direct Fusion Drive technical animation
Ion engines
Magnetic propulsion devices
Nuclear spacecraft propulsion
Fusion power
Spacecraft propulsion | Direct Fusion Drive | [
"Physics",
"Chemistry"
] | 1,042 | [
"Matter",
"Ion engines",
"Plasma physics",
"Fusion power",
"Nuclear fusion",
"Ions"
] |
57,936,030 | https://en.wikipedia.org/wiki/List%20of%20Mamiellophyceae%20genera | This is a list of genera in the green algae class Mamiellophyceae, sub-divided by order and family. The list is based on the data available in AlgaeBase, the Integrated Taxonomic Information System (ITIS), the National Center for Biotechnology Information taxonomic database (NCBI), and other taxonomic databases.
Order Dolichomastigales
Family Crustomastigaceae
Crustomastix
Family Dolichomastigaceae
Dolichomastix
Microrhizoidea
Order Mamiellales
Family Bathycoccaceae
Bathycoccus
Ostreococcus
Family Mamiellaceae
Mamiella
Mantoniella
Micrinomonas
Micromonas
Order Monomastigales
Family Monomastigaceae
Monomastix
References
External links
Mamiellophyceae genera
Mamiellophyceae
Mamiellophyceae | List of Mamiellophyceae genera | [
"Biology"
] | 174 | [
"Algae",
"Lists of algae"
] |
57,936,744 | https://en.wikipedia.org/wiki/Butroxydim | Butroxydim is a chemical used as a herbicide. It is a group A herbicide used to kill grass weeds in a range of broadacre crops. Structurally related herbicides against grasses are alloxydim, sethoxydim, clethodim, and cycloxydim.
References
Ketones
Ketoxime ethers
Herbicides
Ethoxy compounds | Butroxydim | [
"Chemistry",
"Biology"
] | 80 | [
"Ketones",
"Herbicides",
"Biocides",
"Functional groups"
] |
57,936,783 | https://en.wikipedia.org/wiki/Genetics%20in%20fiction | Aspects of genetics including mutation, hybridisation, cloning, genetic engineering, and eugenics have appeared in fiction since the 19th century.
Genetics is a young science, having started in 1900 with the rediscovery of Gregor Mendel's study on the inheritance of traits in pea plants. During the 20th century it developed to create new sciences and technologies including molecular biology, DNA sequencing, cloning, and genetic engineering. The ethical implications were brought into focus with the eugenics movement.
Since then, many science fiction novels and films have used aspects of genetics as plot devices, often taking one of two routes: a genetic accident with disastrous consequences; or, the feasibility and desirability of a planned genetic alteration. The treatment of science in these stories has been uneven and often unrealistic. The film Gattaca did attempt to portray science accurately but was criticised by scientists.
Background
Modern genetics began with the work of the monk Gregor Mendel in the 19th century, on the inheritance of traits in pea plants. Mendel found that visible traits, such as whether peas were round or wrinkled, were inherited discretely, rather than by blending the attributes of the two parents. In 1900, Hugo de Vries and other scientists rediscovered Mendel's research; William Bateson coined the term "genetics" for the new science, which soon investigated a wide range of phenomena including mutation (inherited changes caused by damage to the genetic material), genetic linkage (when some traits are to some extent inherited together), and hybridisation (crosses of different species).
Eugenics, the production of better human beings by selective breeding, was named and advocated by Charles Darwin's cousin, the scientist Francis Galton, in 1883. It had both a positive aspect, the breeding of more children with high intelligence and good health; and a negative aspect, aiming to suppress "race degeneration" by preventing supposedly "defective" families with attributes such as profligacy, laziness, immoral behaviour and a tendency to criminality from having children.
Molecular biology, the interactions and regulation of genetic materials, began with the identification in 1944 of DNA as the main genetic material; the genetic code and the double helix structure of DNA was determined by James Watson and Francis Crick in 1953. DNA sequencing, the identification of an exact sequence of genetic information in an organism, was developed in 1977 by Frederick Sanger.
Genetic engineering, the modification of the genetic material of a live organism, became possible in 1972 when Paul Berg created the first recombinant DNA molecules (artificially assembled genetic material) using viruses.
Cloning, the production of genetically identical organisms from some chosen starting point, was shown to be practicable in a mammal with the creation of Dolly the sheep from an ordinary body cell in 1996 at the Roslin Institute.
Genetics themes
Mutants and hybrids
Mutation and hybridisation are widely used in fiction, starting in the 19th century with science fiction works such as Mary Shelley's 1818 novel Frankenstein and H. G. Wells's 1896 The Island of Dr. Moreau.
In her 1977 Biological Themes in Modern Science Fiction, Helen Parker identified two major types of story: "genetic accident", the uncontrolled, unexpected and disastrous alteration of a species; and "planned genetic alteration", whether controlled by humans or aliens, and the question of whether that would be either feasible or desirable. In science fiction up to the 1970s, the genetic changes were brought about by radiation, breeding programmes, or manipulation with chemicals or surgery (and thus, notes Lars Schmeink, not necessarily by strictly genetic means). Examples include The Island of Dr. Moreau with its horrible manipulations; Aldous Huxley's 1932 Brave New World with a breeding programme; and John Taine's 1951 Seeds of Life, using radiation to create supermen. After the discovery of the double helix and then recombinant DNA, genetic engineering became the focus for genetics in fiction, as in books like Brian Stableford's tale of a genetically modified society in his 1998 Inherit the Earth, or Michael Marshall Smith's story of Organ farming in his 1997 Spares.
Comic books have imagined mutated superhumans with extraordinary powers. The DC Universe (from 1939) imagines "metahumans"; the Marvel Universe (from 1961) calls them "mutants", while the Wildstorm (from 1992) and Ultimate Marvel (2000–2015) Universes name them "posthumans".
Stan Lee introduced the concept of mutants in the Marvel X-Men books in 1963; the villain Magneto declares his plan to "make Homo sapiens bow to Homo superior!", implying that mutants will be an evolutionary step up from current humanity. Later, the books speak of an X-gene that confers powers from puberty onwards. X-men powers include telepathy, telekinesis, healing, strength, flight, time travel, and the ability to emit blasts of energy. Marvel's god-like Celestials are later (1999) said to have visited Earth long ago and to have modified human DNA to enable mutant powers.
James Blish's 1952 novel Titan's Daughter (in Kendell Foster Crossen's Future Tense collection) featured stimulated polyploidy (giving organisms multiple sets of genetic material, something that can create new species in a single step), based on spontaneous polyploidy in flowering plants, to create humans with more than normal height, strength, and lifespans.
Cloning
Cloning, too, is a familiar plot device. Aldous Huxley's 1931 dystopian novel Brave New World imagines the in vitro cloning of fertilised human eggs. Huxley was influenced by J. B. S. Haldane's 1924 non-fiction book Daedalus; or, Science and the Future, which used the Greek myth of Daedalus to symbolise the coming revolution in genetics; Haldane predicted that humans would control their own evolution through directed mutation and in vitro fertilisation. Cloning was explored further in stories such as Poul Anderson's 1953 UN-Man. In his 1976 novel, The Boys from Brazil, Ira Levin describes the creation of 96 clones of Adolf Hitler, replicating for all of them the rearing of Hitler (including the death of his father at age 13), with the goal of resurrecting Nazism. In his 1990 novel Jurassic Park, Michael Crichton imagined the recovery of the complete genome of a dinosaur from fossil remains, followed by its use to recreate living animals of an extinct species.
Cloning is a recurring theme in science fiction films like Jurassic Park (1993), Alien Resurrection (1997), The 6th Day (2000), Resident Evil (2002), Star Wars: Episode II (2002) and The Island (2005). The process of cloning is represented variously in fiction. Many works depict the artificial creation of humans by a method of growing cells from a tissue or DNA sample; the replication may be instantaneous, or take place through slow growth of human embryos in artificial wombs. In the long-running British television series Doctor Who, the Fourth Doctor and his companion Leela were cloned in a matter of seconds from DNA samples ("The Invisible Enemy", 1977) and then—in an apparent homage to the 1966 film Fantastic Voyage—shrunk to microscopic size in order to enter the Doctor's body to combat an alien virus. The clones in this story are short-lived, and can only survive a matter of minutes before they expire. Films such as The Matrix and Star Wars: Episode II – Attack of the Clones have featured human foetuses being cultured on an industrial scale in enormous tanks.
Cloning humans from body parts is a common science fiction trope, one of several genetics themes parodied in Woody Allen's 1973 comedy Sleeper, where an attempt is made to clone an assassinated dictator from his disembodied nose.
Genetic engineering
Genetic engineering features in many science fiction stories. Films such as The Island (2005) and Blade Runner (1982) bring the engineered creature to confront the person who created it or the being it was cloned from, a theme seen in some film versions of Frankenstein. Few films have informed audiences about genetic engineering as such, with the exception of the 1978 The Boys from Brazil and the 1993 Jurassic Park, both of which made use of a lesson, a demonstration, and a clip of scientific film. In 1982, Frank Herbert's novel The White Plague described the deliberate use of genetic engineering to create a pathogen which specifically killed women. Another of Herbert's creations, the Dune series of novels, starting with Dune in 1965, emphasises genetics. It combines selective breeding by a powerful sisterhood, the Bene Gesserit, to produce a supernormal male being, the Kwisatz Haderach, with the genetic engineering of the powerful but despised Tleilaxu.
Eugenics
Eugenics plays a central role in films such as Andrew Niccol's 1997 Gattaca, the title alluding to the letters G, A, T, C for guanine, adenine, thymine, and cytosine, the four nucleobases of DNA. Genetic engineering of humans is unrestricted, resulting in genetic discrimination, loss of diversity, and adverse effects on society. The film explores the ethical implications; the production company, Sony Pictures, consulted with a gene therapy researcher, French Anderson, to ensure that the portrayal of science was realistic, and test-screened the film with the Society of Mammalian Cell Biologists and the American National Human Genome Research Institute before its release. This care did not prevent researchers from attacking the film after its release. Philim Yam of Scientific American called it "science bashing"; in Nature Kevin Davies called it a ""surprisingly pedestrian affair"; and the molecular biologist Lee Silver described the film's extreme genetic determinism as "a straw man".
Myth and oversimplification
The geneticist Dan Koboldt observes that while science and technology play major roles in fiction, from fantasy and science fiction to thrillers, the representation of science in both literature and film is often unrealistic. In Koboldt's view, genetics in fiction is frequently oversimplified, and some myths are common and need to be debunked. For example, the Human Genome Project has not (he states) immediately led to a Gattaca world, as the relationship between genotype and phenotype is not straightforward. People do differ genetically, but only very rarely because they are missing a gene that other people have: people have different alleles of the same genes. Eye and hair colour are controlled not by one gene each, but by multiple genes. Mutations do occur, but they are rare: people are 99.99% identical genetically, the 3 million differences between any two people being dwarfed by the hundreds of millions of DNA bases which are identical; nearly all DNA variants are inherited, not acquired afresh by mutation. And, Koboldt writes, believable scientists in fiction should know their knowledge is limited.
See also
Evolution in fiction
:Category:Fiction about genetic engineering
Parasites in fiction
References
Genetics
Biology in fiction | Genetics in fiction | [
"Biology"
] | 2,302 | [
"Genetics"
] |
57,939,226 | https://en.wikipedia.org/wiki/Dixon%20rings | Dixon rings are a form of random packing used in chemical processing. They consist of a stainless steel mesh formed into a ring with a central divider, and are intended to be packed randomly into a packed column. Dixon rings provide a large surface area and low pressure drop while maintaining a high mass transfer rate, making them useful for distillations and many other applications.
Background
Packed columns
Packed columns are used in a range of industries to allow intimate contact between two immiscible fluids which can be liquid/liquid or liquid/gas. The fluids are passed through in a countercurrent flow through a column.
Random column packing
Random column packing used to characterize the maximum volume fraction of a solid object obtained when they are packed randomly. This method of packing has been used since the early 1820s; the types of packing used were originally made out of glass spheres. However, in 1850 they were replaced by a more porous pumice stone and pieces of coke.
In the early 20th century Friedrich Raschig realized the importance of a high void fraction and having the internal surface of the packing media take part in the mass transfer. He designed the Raschig ring, which was more effective than previous forms of random packing and became very popular. Raschig rings are usually built from ceramic or metal and provided a large surface area within the column for interaction between liquid and gas vapors.
The development of the Dixon ring
In 1943 Dr Olaf George Dixon of ICI applied for a patent of a new product for column distillation. He used stainless steel mesh instead of sheet steel in the Lessing ring in order to improve the pressure drop of the packed column (in fact, they were called "wire gauze Lessing rings" in a 1949 publication).
Application
Dixon rings are used for mainly for laboratory distillation applications.
Performance principles
The enhanced performance of the Dixon ring is based on liquid surface tension: when the mesh is wet its surface area increases greatly, with an accompanying increase in the rate of mass transfer. Dixon rings require pre-wetting (flow of liquid over the packed bed prior to starting the reaction flow). While this increases batch processing startup time, the increased performance of the Dixon ring overcomes this.
See also
Random column packing
Fenske helices
References
Chemical equipment
Distillation | Dixon rings | [
"Chemistry",
"Engineering"
] | 466 | [
"Chemical equipment",
"Distillation",
"nan",
"Separation processes"
] |
57,939,963 | https://en.wikipedia.org/wiki/Random%20column%20packing | Random column packing is the practice of packing a distillation column with randomly fitting filtration material in order to optimize surface area over which reactants can interact while minimizing the complexity of construction of such columns. Random column packing is an alternative to structured column packing.
Packed columns
Packed columns utilizing filter media for chemical exchange are the most common devices used in the chemical industry for reactant contact optimization. Packed columns are used in a range of industries to allow intimate contact between two immiscible/partly immiscible fluids, which can be liquid/gas or liquid/liquid. The fluids are passed through a column in a countercurrent flow.
In the column it is important to maintain an effective mass transfer, so it is essential that a packing is selected which will support a large surface area for mass transfer.
History
Random packing was used as early as 1820. Originally the packing material consisted of glass spheres, however in 1850 they were replaced by a more porous pumice stone and pieces of coke.
Applications
Random packed columns are used in a variety of applications, including:
Distillation
Stripping
Carbon dioxide scrubbing
Liquid%E2%80%93liquid extraction
Types
Raschig ring
The Raschig ring is a piece of tube, invented circa 1914, that is used in large numbers in a packing column. Raschig rings are usually made of ceramic or metals, and they provide a large surface area within the column, allowing for interaction between liquid and gas vapors.
Lessing ring
Lessing rings are a type of random packing similar to the Raschig ring invented in the early 20th century by German-born British chemist Rudolf Lessing (1878-1964) of Mond Nickel Company. Originally wrapped from steel strips according to his 1919 patent, now they are made of ceramic. Lessing rings have partitions insides which increase the surface area and enhance mass transfer efficiency. Lessing rings have a high density and an excellent heat and acid resistance. Lessing rings withstand corrosion and are used in regenerative oxide systems and transfer systems.
Pall ring
Pall rings are the most common form of random packing. They are similar to Lessing rings and were developed from the Raschig ring. Pall rings have similar cylindrical dimensions but has rows of windows which increase performance by increasing the surface area. They are suited for low pressure drop and high capacity applications. They have a degree of randomness and a relatively high liquid hold up, promoting a high absorption, especially when the rate of reaction is slow. The cross structure of the Pall ring makes it mechanically robust and suitable for use in deep packed beds.
Białecki ring
The Bialecki ring was patented in 1974 by Polish chemical engineer from Kraków Zbigniew Białecki rings are an improved version of Raschig rings. The rings may be injection moulded of plastics or press-formed from metal sheet without welding. Specific surface area of filling ranges between 60 and 440 m2/m3.
Dixon ring
Dixon rings have a similar design to Lessing rings. They are made of stainless steel mesh, giving Dixon rings a low pressure drop and after pre-wetting. Dixon rings have a very large surface area, which increases the rate of mass transfer. Dixon rings have a large liquid hold up, a low pressure drop and a large surface area, and have a high mass transfer rate. Dixon rings are used for laboratory distillation and scrubbing applications.
References
Chemical process engineering | Random column packing | [
"Chemistry",
"Engineering"
] | 709 | [
"Chemical process engineering",
"Chemical engineering"
] |
64,510,569 | https://en.wikipedia.org/wiki/Berlekamp%20switching%20game | The Berlekamp switching game is a mathematical game proposed by American mathematician Elwyn Berlekamp. It has also been called the Gale–Berlekamp switching game, after David Gale, who discovered the same game independently, or the unbalancing lights game. It involves a system of lightbulbs controlled by two banks of switches, with one game player trying to turn many lightbulbs on and the other trying to keep as many as possible off. It can be used to demonstrate the concept of covering radius in coding theory.
Rules
The equipment for playing the game consists of a room containing rectangular array of lightbulbs, of dimensions for some numbers and . A bank of switches on one side of the room controls each lightbulb individually. Flipping one of these switches changes its lightbulb from off to on or from on to off, depending on its previous state. On the other side of the room is another bank of switches, one for each row or column of lightbulbs. Whenever any of these switches is flipped, every lightbulb in the row or column that it controls changes from off to on or from on to off, depending on its previous state. When flipping more than one switch, the order in which the switches are flipped does not make a difference to the outcome: the same lightbulbs will be lit at the end of the sequence of flips no matter what order they are flipped.
The game is played in two rounds. In the first round, the first player uses the switches that control individual lights, to set the lights on or off arbitrarily. In the second round, the second player uses the switches that control rows or columns of lights, changing the pattern of lights set by the first player into another pattern (or, possibly, leaving it unchanged). The goal of the first player is to have as many lights remaining lit at the end of the game as possible, and the goal of the second player is to have as few lights remaining lit as possible. Therefore, the first player should choose a pattern of lights for which the second player cannot turn off many lights.
History
Berlekamp worked at Bell Labs in Murray Hill, New Jersey from 1966 to 1971. While there, he constructed a physical instance of this game for the case in the Mathematics Department commons room. David Gale also invented the game independently, some time prior to 1971.
Early research on related problems included publications by , whose computer experiments can be interpreted as asking, for the game, how well the second player can do against a first player who plays randomly, and by , who address Gleason's question theoretically, showing that for almost all choices of the first player, in the limit of large game board sizes, the optimal game value is close to .
Analysis
Mathematically, one can describe the lights turned on by the first player's move as a set , and the smallest number of lights that can be achieved by the best play for the second player as a number . The best play for the first player is to choose a set that maximizes . Therefore, one can describe the largest number of lights that can be achieved by the best play for the first player as a number . Beyond the question of how to play well in an individual game, a broader question that has been the object of mathematical research is to characterize the value of in general, as a function of and , to determine its behavior as a function, or to calculate its value for as many combinations of and as possible.
The case of a square array has been solved for . Additionally, lower bounds for have been found for . These numbers are:
Asymptotically, these numbers grow as .
Computational complexity
Because there are exponentially many choices for which switches to flip, an exhaustive search for the optimal choice is not possible for large , setting up the question of how well computationally-limited players can play this game.
The first player can cause the expected game value to be by playing randomly. Similarly, the second player can obtain a value whose expected distance from is by playing randomly; this value might either be larger or smaller than , but if it is larger the second player can flip all row switches to get a value that is smaller by the same amount. This random strategy for the second player can be made non-random using the method of conditional probabilities, giving a polynomial time algorithm that obtains the same solution value guarantees. A different derandomization gives a parallel algorithm in the complexity class NC.
Finding the optimal choice for the second player in the game, once the first player has chosen which bulbs to light, is an NP-hard problem. However, there is a polynomial-time approximation scheme for the game that can find a choice for the second player that leaves only times the minimum possible number of lit bulbs, for any , in time .
Connection to coding theory
The Berlekamp switching game can be used in coding theory as a demonstration of the covering radius of a certain binary linear code. A binary linear code of length and dimension is defined as a -dimensional linear subspace of the -dimensional vector space over the finite field with two elements, . The elements of the subspace are called codewords, and the covering radius is the smallest number such that every point of is within Hamming distance of a codeword.
Let and . For these parameter values, the vector space describes all possible patterns of lit bulbs on the array of lightbulbs, with a vector addition operation that combines two patterns by lighting the bulbs that appear in exactly one of the two patterns (the symmetric difference operation on the sets of lit bulbs). One can define a linear subspace consisting of all patterns that the second player can turn completely off, or equivalently of all patterns that the second player could create starting with a board that is completely off. Although the second player has choices for how to set the second bank of switches, this subspace has elements, giving it dimension , because flipping all of the second player's switches has no effect on the pattern of lit bulbs.
Then is the covering radius of this code. The set of lit bulbs chosen by the first player, with best play, gives a point of that is as far as possible from the linear subspace. The set of bulbs whose state is changed by the second player, with best play, gives the closest point in the linear subspace. The set of bulbs that remain lit after these choices are the ones whose number defines the Hamming distance between these two points.
See also
Lights Out (game), a different puzzle involving turning off lightbulbs using switches that control multiple bulbs
References
Coding theory
Mathematical games | Berlekamp switching game | [
"Mathematics"
] | 1,358 | [
"Recreational mathematics",
"Discrete mathematics",
"Coding theory",
"Mathematical games"
] |
64,510,942 | https://en.wikipedia.org/wiki/Securinine | Securinine is an alkaloid found in Securinega suffruticosa and Phyllanthus niruri.
Pharmacology
Securinine has pro-convulsant effects and it has a strong spastic effect, similar to the actions of strychnine.
Securinine is a GABA-A antagonist.
See also
Norsecurinine
Phenazine
References
Tetracyclic compounds
Nitrogen heterocycles
Lactones
Indolizidine alkaloids
Furanones
Cyclohexenes
Withdrawn drugs | Securinine | [
"Chemistry"
] | 115 | [
"Drug safety",
"Withdrawn drugs"
] |
64,513,306 | https://en.wikipedia.org/wiki/Clair%20Linzey | Clair Susan Linzey is a British theologian, ethicist, editor, and writer. She is the Frances Power Cobbe Professor of Animal Theology at the Graduate Theological Foundation and Deputy Director of the Oxford Centre for Animal Ethics. Linzey's research centres on animal theology and ethics, environmental ethics, systematic and feminist theology, and Christian ethics. She is also co-editor of the Journal of Animal Ethics and the Palgrave Macmillan Animal Ethics Series.
Early life and education
Clair Susan Linzey is the daughter of the theologian Andrew Linzey. In 2004, she received a Master of Arts in Theological Studies from the University of St Andrews, Scotland, where she received several prizes. Linzey received two scholarships to study for a Master of Theological Studies at Harvard Divinity School, graduating in 2008. She received her Doctor of Philosophy on the ecological theology of Leonardo Boff, with a particular focus on its relation to animals, also from St Andrews.
Career
Linzey is the Frances Power Cobbe Professor of Animal Theology at the Graduate Theological Foundation, Deputy Director of the Oxford Centre for Animal Ethics and the director of their annual summer school, as well as a Research Fellow in Animal Ethics at Wycliffe Hall, Oxford. She is also co-editor, with her father, of the Palgrave Macmillan Animal Ethics Series and the Journal of Animal Ethics. Linzey specialises in animal theology and ethics, environmental ethics, systematic and feminist theology, and Christian ethics.
Bibliography
Books authored by Clair Linzey:
Developing Animal Theology: An Engagement with Leonardo Boff (Routledge, 2021)
Books co-authored with Andrew Linzey:
An Ethical Critique of Fur Factory Farming (Palgrave Macmillan, 2022)
Books co-edited with Andrew Linzey:
Animal Ethics for Veterinarians (University of Illinois Press, 2017)
The Ethical Case Against Animal Experiments (University of Illinois Press, 2018)
The Palgrave Macmillan Handbook of Practical Animal Ethics (Palgrave Macmillan, 2018)
The Routledge Handbook of Religion and Animal Ethics (Routledge, 2018)
Ethical Vegetarianism and Veganism (Routledge, 2018)
Animal Ethics and Animal Law (Lexington Books, 2023)
Animal Theologians (Oxford University Press, 2023)
The Ethics of Fur: Religious, Cultural, and Legal Perspectives (Rowman & Littlefield, 2023)
References
External links
Clair Linzey PhD - Animal Theology Keynote
Animal Ethics & Veganism: Interview with Dr Clair Linzey from the Oxford Centre for Animal Ethics
Date of birth missing (living people)
Living people
21st-century British theologians
Alumni of the University of St Andrews
Animal ethicists
British animal rights scholars
British book editors
English vegetarianism activists
Environmental ethicists
Fellows of Wycliffe Hall, Oxford
Graduate Theological Foundation faculty
Harvard Divinity School alumni
Philosophy journal editors
Women theologians
Year of birth missing (living people)
21st-century British non-fiction writers
21st-century British writers
21st-century British women writers
British women non-fiction writers | Clair Linzey | [
"Environmental_science"
] | 596 | [
"Environmental ethicists",
"Environmental ethics"
] |
64,514,125 | https://en.wikipedia.org/wiki/Mixture%20fraction | Mixture fraction () is a quantity used in combustion studies that measures the mass fraction of one stream of a mixture formed by two feed streams, one the fuel stream and the other the oxidizer stream. Both the feed streams are allowed to have inert gases. The mixture fraction definition is usually normalized such that it approaches unity in the fuel stream and zero in the oxidizer stream. The mixture-fraction variable is commonly used as a replacement for the physical coordinate normal to the flame surface, in nonpremixed combustion.
Definition
Assume a two-stream problem having one portion of the boundary the fuel stream with fuel mass fraction and another portion of the boundary the oxidizer stream with oxidizer mass fraction . For example, if the oxidizer stream is air and the fuel stream contains only the fuel, then and . In addition, assume there is no oxygen in the fuel stream and there is no fuel in the oxidizer stream. Let be the mass of oxygen required to burn unit mass of fuel (for hydrogen gas, and for alkanes, ). Introduce the scaled mass fractions as and . Then the mixture fraction is defined as
where
is the stoichiometry parameter, also known as the overall equivalence ratio. On the fuel-stream boundary, and since there is no oxygen in the fuel stream, and hence . Similarly, on the oxidizer-stream boundary, and so that . Anywhere else in the mixing domain, . The mixture fraction is a function of both the spatial coordinates and the time , i.e.,
Within the mixing domain, there are level surfaces where fuel and oxygen are found to be mixed in stoichiometric proportion. This surface is special in combustion because this is where a diffusion flame resides. Constant level of this surface is identified from the equation , where is called as the stoichiometric mixture fraction which is obtained by setting (since if they were react to consume fuel and oxygen, only on the stoichiometric locations both fuel and oxygen will be consumed completely) in the definition of to obtain
.
Relation between local equivalence ratio and mixture fraction
When there is no chemical reaction, or considering the unburnt side of the flame, the mass fraction of fuel and oxidizer are and (the subscript denotes unburnt mixture). This allows to define a local fuel-air equivalence ratio
The local equivalence ratio is an important quantity for partially premixed combustion. The relation between local equivalence ratio and mixture fraction is given by
The stoichiometric mixture fraction defined earlier is the location where the local equivalence ratio .
Scalar dissipation rate
In turbulent combustion, a quantity called the scalar dissipation rate with dimensional units of that of an inverse time is used to define a characteristic diffusion time. Its definition is given by
where is the diffusion coefficient of the scalar. Its stoichiometric value is .
Liñán's mixture fraction
Amable Liñán introduced a modified mixture fraction in 1991 that is appropriate for systems where the fuel and oxidizer have different Lewis numbers. If and are the Lewis number of the fuel and oxidizer, respectively, then Liñán's mixture fraction is defined as
where
The stoichiometric mixture fraction is given by
.
References
Fluid dynamics
Combustion | Mixture fraction | [
"Chemistry",
"Engineering"
] | 664 | [
"Piping",
"Chemical engineering",
"Combustion",
"Fluid dynamics"
] |
64,514,313 | https://en.wikipedia.org/wiki/Industrial%20Union%20of%20Chemicals%2C%20Glass%20and%20Ceramics | The Industrial Union of Chemicals, Glass and Ceramics (, IG CGK) was a trade union representing workers in various industries in East Germany.
The union was founded by the Free German Trade Union Federation in 1946, initially as the Industrial Union of Chemicals, Paper, Stone and Earth. It initially had 230,464 members. In 1947, its name was changed to the Industrial Union of Chemicals, Paper and Ceramics, and then in 1950 it was shortened to the Industrial Union of Chemicals.
The remit of the union also changed over the years. In 1955, its members in the building materials sector were transferred to the Industrial Union of Construction and Wood, and in 1956 various members moved to the Industrial Union of the Local Economy, although they returned in 1958. The biggest changes came in 1957, when the union's headquarters moved from Berlin to Halle, and its members in textile manufacturing and forestry were transferred to other unions.
Internationally, the union affiliated to the Trade Unions International of Chemical, Oil and Allied Workers. The union became involved in sports associations, their names starting with "SV Chemie".
The membership of the union continued to change until the 1972, when it also adopted its final name, the "Industrial Union of Chemicals, Glass and Ceramics". In addition to these areas, it also represented workers in the paper and petroleum industries, and in waste disposal.
By 1989, the union had 531,301 members. It became independent in April 1990. It began working closely with the Chemical, Paper and Ceramic Union, and gradually merged into it, completing the process in June 1991.
Presidents
1950: Kurt Kühn
1952: Horst Willim
1958: Rudolf Höppner
1965: Hans-Joachim Winkler
1967: Werner Oertelt
1980: Edith Weber
1989: Hartmut Löschner
References
Chemical industry trade unions
Trade unions in East Germany
Trade unions established in 1946
Trade unions disestablished in 1991 | Industrial Union of Chemicals, Glass and Ceramics | [
"Chemistry"
] | 384 | [
"Chemical industry trade unions"
] |
64,514,712 | https://en.wikipedia.org/wiki/Vector-valued%20Hahn%E2%80%93Banach%20theorems | In mathematics, specifically in functional analysis and Hilbert space theory, vector-valued Hahn–Banach theorems are generalizations of the Hahn–Banach theorems from linear functionals (which are always valued in the real numbers or the complex numbers ) to linear operators valued in topological vector spaces (TVSs).
Definitions
Throughout and will be topological vector spaces (TVSs) over the field and will denote the vector space of all continuous linear maps from to , where if and are normed spaces then we endow with its canonical operator norm.
Extensions
If is a vector subspace of a TVS then has the extension property from to if every continuous linear map has a continuous linear extension to all of . If and are normed spaces, then we say that has the metric extension property from to if this continuous linear extension can be chosen to have norm equal to .
A TVS has the extension property from all subspaces of (to ) if for every vector subspace of , has the extension property from to . If and are normed spaces then has the metric extension property from all subspace of (to ) if for every vector subspace of , has the metric extension property from to .
A TVS has the extension property if for every locally convex space and every vector subspace of , has the extension property from to .
A Banach space has the metric extension property if for every Banach space and every vector subspace of , has the metric extension property from to .
1-extensions
If is a vector subspace of normed space over the field then a normed space has the immediate 1-extension property from to if for every , every continuous linear map has a continuous linear extension such that . We say that has the immediate 1-extension property if has the immediate 1-extension property from to for every Banach space and every vector subspace of .
Injective spaces
A locally convex topological vector space is injective if for every locally convex space containing as a topological vector subspace, there exists a continuous projection from onto .
A Banach space is 1-injective or a -space if for every Banach space containing as a normed vector subspace (i.e. the norm of is identical to the usual restriction to of 's norm), there exists a continuous projection from onto having norm 1.
Properties
In order for a TVS to have the extension property, it must be complete (since it must be possible to extend the identity map from to the completion of ; that is, to the map ).
Existence
If is a continuous linear map from a vector subspace of into a complete Hausdorff space then there always exists a unique continuous linear extension of from to the closure of in .
Consequently, it suffices to only consider maps from closed vector subspaces into complete Hausdorff spaces.
Results
Any locally convex space having the extension property is injective.
If is an injective Banach space, then for every Banach space , every continuous linear operator from a vector subspace of into has a continuous linear extension to all of .
In 1953, Alexander Grothendieck showed that any Banach space with the extension property is either finite-dimensional or else separable.
{{Math theorem|name=Theorem |math_statement=
Suppose that is a Banach space over the field
Then the following are equivalent:
is 1-injective;
has the metric extension property;
has the immediate 1-extension property;
has the center-radius property;
has the weak intersection property;
is 1-complemented in any Banach space into which it is norm embedded;
Whenever in norm-embedded into a Banach space then identity map can be extended to a continuous linear map of norm to ;
is linearly isometric to for some compact, Hausdorff space, extremally disconnected space . (This space is unique up to homeomorphism).
where if in addition, is a vector space over the real numbers then we may add to this list:
has the binary intersection property;
is linearly isometric to a complete Archimedean ordered vector lattice with order unit and endowed with the order unit norm.
}}
Examples
Products of the underlying field
Suppose that is a vector space over , where is either or and let be any set.
Let which is the product of taken times, or equivalently, the set of all -valued functions on .
Give its usual product topology, which makes it into a Hausdorff locally convex TVS.
Then has the extension property.
For any set the Lp space has both the extension property and the metric extension property.
See also
Citations
References
Topological vector spaces
Theorems in functional analysis | Vector-valued Hahn–Banach theorems | [
"Mathematics"
] | 950 | [
"Theorems in mathematical analysis",
"Vector spaces",
"Topological vector spaces",
"Space (mathematics)",
"Theorems in functional analysis"
] |
64,514,718 | https://en.wikipedia.org/wiki/Aluminium%20monohydroxide | Hydroxyaluminium(I), also known as Aluminium(I) hydroxide, is an inorganic chemical with molecular formula AlOH. It consists of aluminium in the +1 oxidation state paired with a single hydroxide. It has been detected as a molecular substance in the envelope of an oxygen-rich red supergiant star, a place where substances containing metals or hydroxides are thought to be rare.
Production
In the laboratory AlOH can be made by heating aluminium, so that it vapourises into low pressure hydrogen peroxide vapour. Another method is to condense a mixture of aluminium vapour, hydrogen and oxygen with argon into a solid at 10K. Along with AlOH, there are also Al(OH)2, Al(OH)3, HAl(OH)2, cyc-AlO2 and AlOAl molecules formed.
Properties
The bond lengths are, Al-O 1.682 Å, and for O-H 0.878 Å. The rotational constants are B0=15,740.2476 MHz and D0=0.02481 MHz.
References
Astrochemistry
Aluminium(I) compounds
Hydroxides | Aluminium monohydroxide | [
"Chemistry",
"Astronomy"
] | 243 | [
"Inorganic compounds",
"Hydroxides",
"Inorganic compound stubs",
"Astrochemistry",
"nan",
"Bases (chemistry)",
"Astronomical sub-disciplines"
] |
64,515,728 | https://en.wikipedia.org/wiki/Far%20Cry%206 | Far Cry 6 is a 2021 first-person shooter game developed by Ubisoft Toronto and published by Ubisoft. It is the sixth main installment in the Far Cry series and the successor to 2018's Far Cry 5. The game is set on the fictional Caribbean island of Yara, ruled as a dictatorship by "El Presidente" Antón Castillo (portrayed by Giancarlo Esposito) , who is raising his son Diego (Anthony Gonzalez) to follow in his rule. Players take on the role of guerrilla fighter Dani Rojas (voiced by either Nisa Gunduz or Sean Rey), attempting to topple Castillo and his regime. Gameplay focuses on combat and exploration; players battle enemy soldiers and dangerous wildlife using a wide array of weapons and gadgets. The game features numerous elements commonly found in role-playing games, such as a leveling-up system and side quests. It also features a cooperative multiplayer mode.
Development of Far Cry 6 began around 2016 and was extensive. The team studied several revolutions of recent history for the game's narrative, primarily the Cuban Revolution of 1953–1959. The game was designed to be "political", covering themes such as the rise of fascism in a nation, the costs of imperialism, and the need for free and fair elections, in response to the controversy generated by Far Cry 5. The development team also sought to bring back several elements from earlier Far Cry titles such as a tropical setting and a fully-voiced protagonist. The game was first teased by Esposito in July 2020, and officially announced later that month, at the Ubisoft Forward online event.
Far Cry 6 was released worldwide for PlayStation 4, PlayStation 5, Stadia, Windows, Xbox One and Xbox Series X/S on October 7, 2021. It received mixed reviews from critics, who praised the small improvements brought to the series' gameplay formula, but criticized its story and lack of innovation. Several releases of downloadable content were subsequently published, including three expansion packs centered around antagonists from past Far Cry games.
Gameplay
Similar to the previous entries in the series, Far Cry 6 is a first-person shooter game, set in an open world environment navigable on foot or via various land, water, and air vehicles. Players assume the role of a local rebel named Dani Rojas, a former conscript in the military turned into a guerrilla fighter, whose gender they can select at the start of the game. The world is divided into seven main regions with an array of terrain, ranging from urban areas and dense jungles, to mountain ranges and open oceans. Gameplay focuses on armed and close-quarters combat. Players are able to use a wide array of conventional weapons (such as sidearms, assault rifles, submachine guns, shotguns, light-machine guns, sniper rifles and grenade launchers). Firearms can be customized using materials found throughout the world.
In a new addition to the series, the game features several prototypes of special weaponry, called "Resolver weapons", each offering a certain perk to the player's loadout, for example a silent close-range nailgun or a sling-shot projectile weapon which fires CDs. Another new addition is the "Supremo" backpacks, allowing augmentation of the playstyle by assigning more perks to the player's loadout, such as firing homing missiles or seeing enemies through solid objects. Unlike the previous titles in the series, players are able to holster weapons; as a result, enemy NPCs will not attack the player on sight, unless within restricted areas.
The game introduces a "Rank Level" system which indicates the player's rank and highlights the level of a specific region. As the game progresses and the player explores more of the world, enemy forces will be equipped with more powerful gear and target locations become more heavily fortified. Like previous games in the series, outposts are scattered throughout the world, allowing the player to kill or neutralize the enemy presence to reduce the dominance of forces in a particular area. The game also implements a new notoriety and reputation-style gameplay mechanic. If a high notoriety level is earned, as a result of actions taken against enemy NPCs for example, the player will be hunted by special forces. The notoriety meter can be reduced by fleeing combat and staying hidden for a specific period of time.
The player has the ability to construct and upgrade guerrilla bases called "Camp Facilities", which provide useful resources and in-game bonuses to increase the skillset of the character, specialize perks in hunting animals, unlock fast travel locations throughout Yara, enlist new recruits and manage their equipment, or launch friendly NPC operations. The game's version of Far Cry 5s "Fangs for Hire" companion system returns, called "Amigos", which features recruitable animals with a variety of abilities and perks tasked to assist the player in combat and exploration.
Plot
Far Cry 6 takes place in 2021 in Yara, a fictional Caribbean island nation inspired by Cuba ruled by the dictator Antón Castillo (Giancarlo Esposito). In 1967, a guerrilla revolution topples the regime of Antón's father, leading to Yara's isolation from the rest of the world. Following the nation's collapse, Antón becomes a political prisoner. In 2019, Antón is elected president and oversees the creation of Viviro, a new cancer treatment developed from Yara's tobacco, promising it will stabilize the nation's economy. Two years later, Antón announces a draft "lottery" to conscript citizens as farmers in the tobacco fields. Antón has a 13-year-old son, Diego (Anthony Gonzalez), whom he grooms to be his successor.
In the capital Esperanza, as Yara's armed forces round up citizens for the draft, Dani Rojas prepares to escape to the American city of Miami via fishing boat, alongside friends Lita Torres and Alejo Ruiz. Alejo is shot and killed after provoking troops in the street, while Dani and Lita flee to the awaiting boat filled with other refugees and escape. However, Antón stops the boat and reveals that Diego was attempting to flee with them. After retrieving Diego, he orders the boat sunk by gunfire. Dani survives the commotion and wakes up with a mortally wounded Lita on an island's beach, far away from Esperanza. As Lita dies, she urges Dani to look for the nearby Clara Garcia, leader of the guerilla movement Libertad. Upon arrival, Clara tells Dani to invite ex-spymaster and weapon maker Juan Cortez back into Libertad, disrupt the Fuerzas Nacionales de Defensa (FND) forces on the island, and clear the blockade trapping the guerrillas in the region. Once Dani fulfills all the tasks, Clara gives Dani a boat to flee Yara. If Dani does not leave, Clara gives the order to aid anti-Castillo forces throughout Yara's three major regions—Madrugada, Valle de Oro, and El Este—and convince them to help Libertad oust Antón.
In Madrugada, Dani searches for the revered Montero family, who are allied with the region's guerrillas and tobacco workers. They take down General José Castillo—Antón's nephew, commander of Yara's air force, and a slave driver who robbed the Monteros and other local farmers of their lands to grow the Viviro tobacco. Over in Valle de Oro, Dani assists the rap band Máximas Matanzas in airing TV and radio performances to push back against pro-Castillo propaganda spread by María Marquessa, Yara's Minister of Culture and Diego's mother. Upon killing María during a televised interview about Viviro, they encounter Dr. Edgar Reyes, the scientist behind Viviro's conception; it is revealed that he performed cruel experiments on disenfranchised tobacco workers in concentration camps as part of his effort to create the drug. With this in mind, Dani goes to one of his research facilities and kills him. Meanwhile in El Este, a man known as "El Tigre" awaits Dani's arrival on top of a mountain hideout housing the Legends of ‘67, the veteran revolutionaries who overthrew Antón's father. While he is willing to help Libertad, the others are not, so Dani shows them photos of poor working conditions in tobacco farms to convince them to join. While attempting this, Dani comes across an anarchist rebel group of university students known as La Moral who are fighting against Yara's naval commander Admiral Benítez. The two groups unite and storm Benítez's fort to kill her, ending her iron-fisted rule on Yara's seas. They then track down Sean McKay, a Canadian business magnate who handles Viviro exports and imports, and either kill him or make a deal with him to finance Libertad.
After uniting the anti-Castillo forces under Libertad, Dani learns that Antón is holding Clara at his private island's villa, under the pretence of a parley. When Dani confronts him, he and Diego reveal that Antón has been suffering from leukemia for 13 years, and the Viviro treatment stopped working 6 months earlier. Impressed by Dani's feats, and wishing that Diego has a protector for when he dies, Antón demands that Dani become his general in exchange for Clara's life. Juan attempts to assassinate Antón but opts to shoot Diego instead, though Dani knocks him out of the way. In response to the shooting, Antón kills Clara and escapes with Diego to Esperanza. Backed by the anti-Castillo forces, Dani enters Antón's presidential palace alone and confronts him in his office. Dani promises to protect Diego, but Antón, believing that Diego would instead be tortured as he had been after his father's toppling, shoots him before committing suicide. The resistance forces unite with Dani and witness the Castillo corpses. They unanimously declare Dani the new leader of Yara, but Dani refuses the leadership, turning it over to them. After burying Clara, Dani and Juan wage war against Castillo's surviving loyalists.
An alternate ending occurs if Dani sails away from Yara before confronting Castillo. Dani will be shown three months later relaxing on a beach in Miami, with a news broadcast detailing how Castillo has consolidated his hold over Yara by crushing rebel forces and executing Clara.
Development
For the first time, the game's development was led by Ubisoft Toronto, which had previously worked as a co-developer on previous games in the series. A total of 10 Ubisoft subsidiaries worked in the co development of the game including Ubisoft Montreal, Ubisoft Kyiv, Ubisoft Berlin, Ubisoft Shanghai, Ubisoft Philippines, Ubisoft Bucharest, Ubisoft Pune, Ubisoft Odessa, Ubisoft Winnipeg, Ubisoft Montpellier and Ubisoft Québec respectively. The advancement of the game took place in the middle of the Covid-19 pandemic, and was met with several constraints. The game runs on the Dunia 2 engine, with new features such as ray tracing support on the PC version and support for AMD's open source variable resolution technology, FidelityFX Super Resolution.
Gameplay design
The developers aimed to provide players with numerous choices in how they wish to experience the entire campaign, players being able to approach the story however they like. In contrast to the previous installment where the player is mute and interactions were limited, in this game, the protagonist is fully voiced, regarding this narrative director Navid Khavari, stated, "It was essential for us to ensure that the protagonist has a personal investment in that revolution." It is also the first game in the series to feature cut-scenes presented from a 3rd person perspective. As stated by Khavari, this helps players experience the story from a different angle since the main character is not present in those scenarios.
Takedown animations that were featured in previous editions but were scrapped in Far Cry 5 were restored. For the 'Guns for Hire,' humans were excluded from the game, and the focus was solely on animals. The development team scrapped the Map Editor and Arcade Mode, which were present in the previous instalments, instead they focused exclusively on improving the main campaign.
Setting, themes and influences
For the creation of Yara, the developers drew inspiration from various Caribbean nations, with Cuba being one of them. Khavari said that they started researching revolutions of the past, they came across the idea of the modern guerrilla revolution such as the Cuban Revolution, which gave them numerous ideas of how to drive the player-character into fighting against a repressive government. Khavari spent a month in Cuba, speaking to residents there to help develop the setting. Using Cuba as an influence also re-established the return to a tropical setting, a feature of the earlier Far Cry games, as well as giving the setting a "timeless" look due to economic blockades that had been imposed on the island, blending vintage cars with modern weapons. To achieve this, the developers studied the history, classic cars, and vibrant Caribbean colors.
This is a first for a Far Cry game to feature a major capital city that includes the antagonist's presidential palace. The game includes a large urban area and encompass a mix of open and closed buildings, offering rooftop runs, guerrilla paths through sewers, climbing, jumping, and gunfights in city streets. In terms of the environment, the development team drew inspiration directly from the Caribbean, which offers a wide range of biome variations. For the creation of trees, rocks, and foliage, the team took thousands of reference photos that are present on Caribbean islands. They built an extensive library of photogrammetry assets to ensure maximum realism when bringing the flora and fauna to life. The team analyzed color palettes in Cuba and endeavoured to understand how color is utilized in the country.
In contrast to the media controversy over Ubisoft distancing its stance that Far Cry 5 was made as a political statement, Khavari said that Far Cry 6 was "political", adding: "A story about a modern revolution must be". While the game's narrative element is based on stories around Cuba, Khavari stated that the game "doesn't want to make a political statement about what's happening in Cuba specifically", and does not attempt to make "a simplified, binary political statement specifically on the current political climate in Cuba". Khavari's family had experienced the Iranian Revolution in the late 1970s, eventually having fled to Canada, and using these experiences, those from Cuba, and from other research that Ubisoft had done, he wanted Far Cry 6 to have a story "about the conditions that lead to the rise of fascism in a nation, the costs of imperialism, forced labor, the need for free-and-fair elections, LGBTQ+ rights, and more."
Casting and characters
Word of a new Far Cry game was teased in early July 2020, as actor Giancarlo Esposito has mentioned he had recently taken part in a "huge video game", including voice work and motion capture. Shortly after this, rumoured leaks of Far Cry 6s existence appeared, including screens that showed a character resembling Esposito.
Anthony Gonzalez voices and provides the character model and motion capture for Diego. Esposito and Gonzalez had done the motion-capture and voice work for the game's trailer before shooting any of the footage for the game's narrative, as this gave the developers the time to create the character models for the game itself. For Esposito, he had been interested in the motion capture facets of the role, as he had done some for the cancelled Mouse Guard film and was interested in doing more, as well as his interest in the type of character that Ubisoft had created for him. Khavari said they had provided Esposito background material to help prepare before recording for the game, and upon these sessions, he found that Esposito had "done so much research already based on the material that we sent him. He brings an amazing empathy to his characters, and he brought that same empathy to Antón that I wasn't expecting."
Music
Pedro Bromfman composed the score for the game. The game's score consists of music that blends different elements, such as mixing Latin and Caribbean music. It also includes the use of a lot of Caribbean percussion. Regarding this, Bromfman stated, "It's a very unique score." Flamenco guitar, Cuban Tres, and Bolivian ronroco were used to accentuate the oppressive and somber narrative of the game.
Release
Far Cry 6 was originally scheduled for release on February 18, 2021, on PlayStation 4, PlayStation 5, Stadia, Windows, Xbox One and Xbox Series X/S. On October 29, 2020, Ubisoft announced that the release would be delayed due to impacts from the ongoing COVID-19 pandemic. During Ubisoft's quarterly earnings call in February 2021, the company announced that the game would be released before September 30, 2021. As part of further gameplay reveals on May 28, 2021, Ubisoft also announced the planned release date for Far Cry 6 as October 7, 2021.
As part of the game's season pass, additional content includes story episodes letting the player take on the role of three antagonists from preceding Far Cry titles: Vaas Montenegro from Far Cry 3, Pagan Min from Far Cry 4, and Joseph Seed from Far Cry 5 and Far Cry New Dawn, with Michael Mando, Troy Baker, and Greg Bryk reprising their respective roles. In addition, the season pass comes with an updated version of Far Cry 3: Blood Dragon. Additional free content includes a guest appearance by Danny Trejo, a Rambo-inspired mission, and a crossover mission with Stranger Things.
A separate paid expansion titled Lost Between Worlds was released on December 6, 2022. In this expansion, Dani finds themselves stranded in a space between worlds after stumbling across an alien spaceship and an alien artificial intelligence named FAI.
Reception
Far Cry 6 received "mixed or average" reviews from critics, while the Xbox Series X/S version received "generally favorable" reviews, according to review aggregator website Metacritic.
An IGN review by Jon Ryan said that "Far Cry 6 smooths over a lot of the bumps that have cropped up in the past few games. Even though it misses some steps, especially with its new inventory system, it's the best the series has been in years." Destructoids Jordan Devore wrote "Solid and definitely has an audience. There could be some hard-to-ignore faults, but the experience is fun."
Rachel Weber from GamesRadar+ wrote that "Far Cry 6 feels like the turning point for a series in transition. Everything you know and love about it is still there [...] but the small changes that have been made have a big impact on the overall experience", such as the main character being visible in cutscenes. Eurogamer outlined in their review: "There's plenty that's familiar about the latest entry in Ubisoft's open world shooter, but that doesn't stop it being a blast."
Conversely, Polygons Diego Arguello said that Far Cry 6 "is a waste of potential", criticizing its Latin American stereotypes and feeling it fumbled any attempt at saying something meaningful despite the game's overt political theme, citing an instance "in which you rescue refugees by using a weapon that plays Macarena while you're aiming down its sights". Writing for Vice, Matthew Gault criticized and described the game as "creatively and morally bankrupt", noting his article "isn't a review" because he could not continue playing it. Screen Rants Alex Santa Maria and Kotakus Zack Zwiezen both criticized Far Cry 6 for being too similar to its predecessors. The game has also been criticized for including a cockfighting minigame.
Sales
In Japan, the PlayStation 4 version of Far Cry 6 was the second best-selling retail game during its first week of release, with 34,219 physical units being sold. The PlayStation 5 version sold 16,686 physical units in the same week, making it the third best-selling retail game in the country.
Awards and accolades
Notes
References
External links
Far Cry 6 at MobyGames
2021 video games
Biological weapons in popular culture
Far Cry games
Dystopian video games
Fiction about filicide
First-person shooters
Multiplayer and single-player video games
Open-world video games
PlayStation 4 games
PlayStation 5 games
Fiction about rebellions
Stadia games
Ubisoft games
Video game sequels
Video games developed in Canada
Video games with gender-selectable protagonists
Video games postponed due to the COVID-19 pandemic
Video games set in fictional countries
Video games set in the Caribbean
Video games set in Miami
Video games set on fictional islands
Windows games
Xbox One games
Xbox Series X and Series S games | Far Cry 6 | [
"Biology"
] | 4,313 | [
"Biological weapons in popular culture",
"Biological warfare"
] |
64,516,898 | https://en.wikipedia.org/wiki/Music%20and%20sleep | Sleep problems are found to be correlated with poor well-being and low quality of life. Persistent sleeping disturbances can lead to fatigue, irritability, and various health issues. Numerous studies have examined the positive impact of music on sleep quality. As early as 2000 B.C., lullabies were designed to aid infant sleep. For adults with sleep-related disorders, music serves as a useful intervention in reducing stress. Approximately 25% of the population facing sleep difficulties regularly use music as a tool for relaxation. This process can be either self-prescribed or under the guidance of a music therapist.
Music therapy is introduced into the medical field for treating sleeping disorders following scientific experimentations and observations. Compared to other pharmacological methods for improving sleep, music has no reported side effects and is easy to administer. In direct comparisons, music has improved sleep quality greater than audiobooks and has been comparable to sedative hypnotics. In addition, music can be combined with relaxation techniques such as breathing exercises and progressive muscle relaxation. One review of non-pharmacological sleep aids identified music as the only sleep aid with adequate research. The influence of music on sleep has been investigated across various contexts, exploring how music stimuli can influence different aspects of the sleeping experience. Implications of findings help in building up a more effective procedure of musical therapies to target sleep problems.
A number of companies such as Acoustic Sheep (producer of SleepPhones) and Snoozeband produce headbands that play music to make it easier and more comfortable to listen to music while trying to get to sleep.
Major empirical findings
Influence on sleep quality
Research suggests that music contributes to higher perceived sleep quality, greater sleep efficiency, longer sleep durations, less sleep disturbance, and less daytime dysfunction for older adults. This was assessed through improved scores on the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Polysomnography investigations have found listening to slow-tempo music increased slow-wave sleep (deep sleep) and reduced rapid eye movement sleep (lighter sleep stage). Music facilitates a large improvement in sleep quality for insomnia patients. Interventions including music-assisted relaxation and listening to music effectively reduce sleep onset latency for people with insomnia. However, several studies found music to have neither positive nor negative effects on subjective sleep quality for normal individuals.
Modulation on heart rate and blood pressure
Music can reduce sympathetic nervous system activity, decreasing blood pressure and heart rate. The decrease in systolic blood pressure, diastolic blood pressure, and heart rate signal a state of calmness, which is essential for having a good night sleep. Sedative music, which is characterized by a slow tempo, repetitive rhythm, gentle contours, and strings, is effective in generating anxiolytic responses to aid sleep.
Brainwave activity and hormonal responses
Electroencephalogram (EEG) studies give insights into how music alters brainwave activities during sleep. Gentle and soothing music can lead to increased delta wave activities which indicate deep sleep. Several experiments have tested listening to preferred music significantly decreases cortisol levels and reduces the amount of stress experienced. Saliva melatonin, a hormone associated with sleep initiation, was found to be elevated among people using interactive music therapies. These hormones work in attributing a more conducive environment for falling asleep and maintaining stable sleep stages.
Mechanisms
Dickson & Schubert's RPR
Dickson & Schubert summarized and evaluated six researcher proposed reasons (RPR) by which music could potentially aid sleep:
Entrainment: The synchronization of certain biological processes such as neural activity or heart rate with the rhythmic structure of the music. When the rhythmic pattern of music aligns with the natural rhythm of the body, it is more likely to fall asleep quickly.
Masking: Masking involves using music to mitigate the impact of noxious background noises. By listening to music at a comfortable volume, individuals can block those disruptive sounds from outside and create a peaceful sleeping environment.
Enjoyment: Listening to preferred, emotionally relatable, or pleasant music can have a positive impact on mood. This induces positive emotions such as happiness, reducing the stress felt to enhance sleep patterns.
Distraction: Music acts as a distractor to inner stressful thoughts, by providing a focal point of attention. Individuals focusing on the music itself can divert their attention away from worrying thoughts that are keeping them awake.
Expectation: Individuals held the cultural belief that certain types of music can aid their sleep. This belief would act as a placebo effect rather than a direct contributor to sleep quality. They may improve subjective sleeping experience due to the power of suggestions.
Relaxation: Music can induce relaxation response by reducing physiological and psychological stress. Slow tempo and calming melodies can reduce heart rate, decrease cortisol level, and alleviate tension. This makes individual easier to fall asleep.
Habit formation
Dickson & Schubert proposed Habit Formation as an additional RPR under the Arts on Prescription model. Based on classical conditioning, repeated pairing of the music with the intention of sleep can generate a conditioned response. By forming this habit, music alone would be effective in triggering a relaxation response, which signals the body that it is time to sleep. This requires a minimum of three weeks for individuals suffering mild insomnia to become healthy sleepers and continues to improve sleep quality over three months. Music improved sleep quality with increased exposure regardless of differences in the demographic, music genre, duration of treatment, and exposure frequency. Dickson suggests "listening to music that you find relaxing, at the same time, every night for at least three weeks".
Musical genres and features
Typical genres of music used for sleep (sedative music) include classical music, ethnic music, ambient music, meditation music and lullabies, although researchers have recognised a wide diversity of music genres aiding sleep. The characteristics of music that have improved sleep quality in the music-sleep literature include slow tempo, small change of rhythm, and moderate pitch variation of melody. The selection of music (self selected or researcher selected) does not appear to impact sleep quality.
Instrumental vs Lyrics
Instrumental music such as sitar or violin is recognized as more effective in inducing sleep than vocal music. Although lyric gives depth and meaning to the music, it also stimulates cognitive processes, making it more difficult to fall asleep. Whereas instrumental music focuses on the melody and rhythm, it allows for relaxation without the distraction of lyrics. Research has given evidence for the use of instrumental music in improving sleep quality.
Nature Sounds and Binaural Beats
Nature sounds like birdsong or rainfall can provoke a feeling of peacefulness and tranquillity to facilitate sleep. Binaural beats work by presenting two different frequencies to each ear that synchronize brainwave activity. Those two methods can be combined to improve sleep quality by targeting both the sensory experience and brainwave alterations.
Sedative music developed in collaboration with researchers
Can't Sleep (app) - Gaelen Thomas Dickson (music psychology)
Pzizz (app) - Maryanne Garry (psychology)
Marconi Union - Weightless (song) - Lyz Cooper (sound therapy)
Max Richter - Sleep (album) - David Eagleman (neuroscience)
Individual variability
While many studies have shown the significant influence of soft slow music on sleep, it is essential to acknowledge that this effect is not uniform across all individuals. Extensive research has revealed the variability in individual responses to musical stimuli, which can be due to their personal preference, cultural background, and susceptibility to different music types. Some may find classical music entertaining, while others prefer ambient music for relaxation. Cultural background can also shape an individual's perception and response to music stimuli. The concept of music and sleep, although applicable to the general population, needs to take into account these differences to tailor each individual's taste. By customizing music choices, the overall effectiveness of music in improving sleep can be maximized, contributing to a better life quality for people.
See also
Long Ambients 1: Calm. Sleep.
Lullaby
Music psychology
Music therapy
Sleep (album)
ASMR
References
Musicology
Music therapy
Music psychology
Sleep | Music and sleep | [
"Biology"
] | 1,638 | [
"Behavior",
"Sleep"
] |
64,520,620 | https://en.wikipedia.org/wiki/Ole%20Martin%20Moen | Ole Martin Moen (; born 28 April 1985) is a Norwegian philosopher who works primarily with applied ethics and value theory. He is Professor of Ethics at Oslo Metropolitan University and Researcher in Philosophy and Principal Investigator for the 5-year research project "What should not be bought and sold?" at the University of Oslo, funded by the Research Council of Norway.
Education and career
Moen received a PhD in philosophy from the University of Oslo in 2013; his dissertation was on hedonism. While conducting PhD research, Moen was visiting scholar at the Uehiro Centre for Practical Ethics at the University of Oxford. As a master's student, he acted as visiting scholar at the University of California, Berkeley and University of Oxford.
Moen has published articles in journals such as the Journal of Medical Ethics, Journal of Bentham Studies, Philosophia, Reason Papers and Think. He has written on a number of controversial topics, including prostitution, active euthanasia, animal welfare, wild animal suffering, school, cosmetic surgery, monogamy, cryonics and transhumanism. Moen's articles have been published in Forbes, The Independent, Washington Times, Aftenposten and Morgenbladet. He is a in-house philosopher on the Norwegian radio show Verdibørsen and runs the podcast Moralistene with Aksel Braanen Sterri.
Together with two other teachers, he established the Humanistskolen in Oslo ("Humanist School in Oslo"). The school was initially refused approval from the Ministry of Education, but after the Ministry of Gender Equality and Discrimination Ombud (LDO) came to the conclusion that the Ministry had refused in contravention of the law, the school nevertheless received approval.
He is signed up for cryopreservation with the Alcor Life Extension Foundation.
Politics
Moen was elected to the Øvre Eiker municipal council for the Progress Party in 2003 and served two years. In 2004, Moen announced his transition to the Liberal People's Party and justified it by saying that "the fight for a liberal FRP has been lost". In December 2005, he announced a move from the municipality, and Snorre Rogstad (Frp) thus took over the position as municipal council representative. Moen has also been secretary of Øvre Eiker Progress Party, deputy leader of the youth organization Liberalistisk Ungdom, leader of Liberalistisk Ungdoms fylkeslag in Oslo, leader of Human-Ethisk Studentlag and project employee at Civita in 2007. Moen has not had any office or association with party politics since leaving the Liberal People's Party.
He has argued that pedophilia (i.e. the sexual attraction to children that does not involve engaging in sexual relations with children) is not immoral, that engaging in sexual activities with children is not immoral either unless it will physically hurt children, and that pedophiles who do not rape children should be praised for their 'willpower'. Moen also advocated for computer-generated AI child pornography.
Awards
In 2019, Moen received the Zapffe Prize of from the University of Oslo, for his article "Anti-Natalism and Human Enhancement". In the article on Peter Wessel Zapffe's philosophy, he argues against Zapffe's antinatalism, instead claiming that we should focus on improving the human condition using biotechnology.
Publications
Articles
Books
References
External links
Moralistene - Moen's podcast (in Norwegian)
Moen on the Unabomber's Ethics - Philosophical Disquisitions: Podcast (Episode #51)
Interview with Michael Pollan (video)
Interview with Peter Singer (video)
1985 births
Living people
21st-century Norwegian philosophers
Animal ethicists
Bioethicists
Cryonicists
Environmental ethicists
Hedonism
Transhumanists
Academic staff of Oslo Metropolitan University
University of Oslo alumni
Academic staff of the University of Oslo | Ole Martin Moen | [
"Environmental_science"
] | 816 | [
"Environmental ethicists",
"Environmental ethics"
] |
64,520,640 | https://en.wikipedia.org/wiki/List%20of%20keyboard%20switches |
Commonly used mechanical switches on pre-built keyboards
Manufacturers frequently build computer keyboards using switches from original equipment manufacturers (OEMs). The switches used determine the feel of the keyboard.
Mechanical keyboard switches for custom keyboards
On the custom mechanical keyboard space, there are far greater quantity of keyboard switches. It is important to note that these do not portray the diversity and number of switches currently on the market.
Future
As time goes on, there are more and more switches being developed and manufactured across the world. Some are by new manufacturers, some are collaborations between companies and manufacturers, and some are consumer made. Some bigger databases that involve more than just our main manufacturers listed here.
On top of a variety of new switches being made, consumers are taking parts of different switches and then going on to make their own switches, called “Franken-switches.”
References
Computer keyboards
Keyboard switches | List of keyboard switches | [
"Technology"
] | 176 | [
"Computing-related lists",
"Lists of computer hardware"
] |
64,521,551 | https://en.wikipedia.org/wiki/Sail%20area-displacement%20ratio | The sail area-displacement ratio (SA/D) is a calculation used to express how much sail a boat carries relative to its weight.
In the first equation, the denominator in pounds is divided by 64 to convert it to cubic feet (because 1 cubic foot of salt water weights 64 pounds). The denominator is taken to the 2/3 power to make the entire metric unit-less (without this, the denominator is in cubic feet, and the numerator is in square feet).
It is an indicator of the performance of a boat. The higher the SA/D, the more lively the boat's sailing performance:
The SA/D, however, does not provide information about a boat behavior in a storm or upwind. A polar diagram from a velocity prediction program gives a more precise view.
See also
Displacement–length ratio
References
Ship measurements
Nautical terminology
Engineering ratios
Naval architecture | Sail area-displacement ratio | [
"Mathematics",
"Engineering"
] | 187 | [
"Naval architecture",
"Metrics",
"Engineering ratios",
"Quantity",
"Marine engineering"
] |
64,522,548 | https://en.wikipedia.org/wiki/Relations.%20Beyond%20Anthropocentrism | Relations. Beyond Anthropocentrism is an open access peer-reviewed journal focusing on ethics and related topics from a non-anthropocentric perspective. The journal aims to create an interdisciplinary forum within Europe to promote discussion of scientific and moral problems that relate to the need to transcend the anthropocentric nature of existing structures of knowledge. The journal's language is English, but it is published in Italy. The content includes commentary, debates, interviews and reports on conferences, activities, workshops, events and other projects. Submissions are intended to be understood by both an academic and lay audience. Relations. was published biannually from 2013 to 2018, then annually in 2019 and 2020. It is edited by Francesco Allegri, Matteo Andreozzi, Sofia Bonicalzi and Eleonora Adorni. Topics of past issues include animal emotions, animal personhood, antispeciesism, wild animal suffering, posthumanism, animal products and energy ethics.
In a 2018 review, Animal Ethics identified Relations. Beyond Anthropocentrism as one of several journals in philosophy and ethics focussed on "animal issues". They also named the long-standing journal Between the Species, the defunct Ethics & Animals, the Journal of Animal Ethics, and Politics & Animals, as well as the Journal of Agricultural and Environmental Ethics (which is not solely focussed on animals) and the Journal of Applied Animal Ethics Research (which had not begun publishing at the time of the article).
See also
Etica & Animali
References
External links
Animal ethics journals
Annual journals
Biannual journals
English-language journals
Environmental ethics journals
Academic journals established in 2013 | Relations. Beyond Anthropocentrism | [
"Environmental_science"
] | 344 | [
"Environmental ethics journals",
"Environmental ethics"
] |
63,156,542 | https://en.wikipedia.org/wiki/International%20Photography%20Hall%20of%20Fame%20and%20Museum | The International Photography Hall of Fame and Museum in St. Louis, Missouri, honors those who have made great contributions to the field of photography.
History
In 1977, the first Hall of Fame and Museum opened in Santa Barbara, California, as a part of the Brooks Institute of Photography. A few years later, in 1983 the museum moved to Oklahoma City and in 2013, moved to its current location, St. Louis, Missouri. The IPHF is the first organization worldwide that recognizes significant contributors to the artistic craft and science of photography.
In addition to an extensive collection of photographs and cameras, IPHF offers lectures and other educational opportunities; surrounding all aspects of photography, past, and present, for people of all ages.
Hall of Fame inductees
The IPHF inductees artists and individuals that have changed the art industry with their photography or inventions. IPHF has more than 70 inductees and archives more than 30,000 images. Each year a nominating committee selects inductees based on their contributions to the art or science of photography and their impact on the history of photography.
1966 Inductees
William Henry Fox Talbot
1968 Inductees
George Eastman
Mathew B. Brady
1971 Inductees
Alfred Stieglitz
1973 Inductees
George W. Harris
1974 Inductees
Edward Steichen
1976 Inductees
Robert Capa
1978 Inductees
Erich Salomon
1979 Inductees
Brassai
Gertrude Kasebier
Peter Henry Emerson
1980 Inductees
Adolf Fassbender
Pirie MacDonald
Victor Hasselblad
1982 Inductees
William Henry Jackson
1984 Inductees
Ansel Adams
August Sander
Bill Brandt
Dorothea Lange
Edward Weston
Eugene Atget
Imogen Cunningham
James Van Der Zee
Oskar Barnack
Paul Strand
Walker Evans
William Eugene Smith
Yasuzo Nojima
1986 Inductees
André Kertész
Clarence White
Diane Arbus
Josef Sudek
Timothy O'Sullivan
1989 Inductees
Paul Lindwood Gittings
1991 Inductees
Dr. Edwin Herbert Land
2000 Inductees
Berenice Abbott
2001 Inductees
Henri Cartier-Bresson
Lewis Hine
2002 Inductees
Carleton Watkins
Gordon Parks
Helmut Gernsheim
2003 Inductees
Andre Adolphe-Eugene Disderi
Peter Dombrovskis
2004 Inductees
Frederick Scott Archer
Robert Frank
Ruth Bernhard
2005 Inductees
Beaumont Newhall
Harold Edgerton
Manuel Alvarez Bravo
2006 Inductees
Arnold Newman
Richard Avedon
2007 Inductees
Roger Fenton
2013 Inductees
Yousef Karsh
2016 Inductees
Annie Leibovitz
Ernst Haas
Graham Nash
John Knoll
Ken Burns
Margaret Bourke-White
Sebastiao Salgado
Steve Jobs
Thomas Knoll
Willard S. Boyle
2017 Inductees
Anne Geddes
Cindy Sherman
Edward Curtis
Ernest H. Brooks II
Harry Benson
James Nachtwey
Jerry Uelsmann
Kenny Rogers
Ryszard Horowitz
William Eggleston
2018 Inductees
Joe Rosenthal
Joel Bernstein
John Sexton
John Loengard
Susan Meiselas
Walter Looss Jr.
2019 Inductees
Bruce Davidson
Elliott Erwitt
Julia Margaret Cameron
Mary Ellen Mark
Olivia Parker
Paul Nicklen
Ralph Gibson
Steve McCurry
Tony Vaccaro
2020 Inductees
Robert Adams
Lynsey Addario
Alfred Eisenstaedt
Hiro
Jay Maisel
Duane Michals
Carrie Mae Weems
Henry Diltz
2021 Inductees
Dawoud Bey
Larry Burrows
Philip-Lorca diCorcia
David Douglas Duncan
Sally Mann
Pete Souza
Joyce Tenneson
Joel Sartore
2022 Inductees
Edward Burtynsky
Chester Higgins
Graciela Iturbide
Helen Levitt
Danny Lyon
Sarah Moon
2023 Inductees
Nan Goldin
Vivian Maier
Bea Nettles
Matika Wilbur
Collection
The IPHF collection focuses on photographic works beginning from the 18th century to the present. In addition to photographs, the museum has a large collection of cameras, darkroom, and studio tools dating back to the late 1800s. The entire collection consists of more than 6,000 historical cameras and photography tools and 30,000 photographs. Some of the 19th-century photographic tools include Magic Lanterns, a Praxinoscope Theatre, and an Edison Projecting Kinetoscope.
Within the collection can be found a wide variety of photographic memorabilia from historic manuals on processes and techniques to monographs of notable photographers.
Exhibitions
Retrospective, Phil Borges, October–December 2004
Alaska Wild, December 2004 – January 2005
In Plain Sight, Beaumont Newhall, January–April 2005
Stopping Time, Harold Edgerton, January–April 2005
Mestizjae, Manuel Alvarez Bravo, January–April 2005
Photography of Hugh Scott, The Oklahoma City National Memorial, 10 Years Remembering, April–July 2005
An Itinerant Eye, James Walden, July–December 2005
A Life In Photography, Arnold Newman, July–December 2005
Nicholas Orzio's Occupied Japan, Nicholas Orzio, February–May 2017
Vivian Maier, Vivian Maier, February–May 2018
Cabbagetown, Oraien Catledge, January–April 2019
40th Year Anniversary: Nanjing-St. Louis Sister City: Retrospective, April–July 2019
Moment By Moment, John Loengard, July–September 2019
2019 Hall of Fame Induction and Awards Exhibition, November 2019–March 2020
References
Awards established in 1965
Halls of fame in Missouri
Museums in St. Louis
Photography awards
Photography museums and galleries in the United States
Science and technology halls of fame | International Photography Hall of Fame and Museum | [
"Technology"
] | 1,080 | [
"Science and technology awards",
"Science and technology halls of fame"
] |
63,158,539 | https://en.wikipedia.org/wiki/Projekt%20Melody | Projekt Melody, or more commonly known as Melody () for short, is an American 3D anime-styled live streamer, or VTuber, and pornographic actress. She first appeared when her Twitter account opened in July 2019, and she has live streamed on Chaturbate and Twitch since early 2020. During her first three days of Chaturbate streaming, Melody's Twitter followers rose from 700 to over 20,000, and her sudden rise in popularity had mixed reactions. In late 2020, Melody became a founding member of VShojo, one of the first VTuber talent agencies based in the Western world. She describes herself as an artificial intelligence, although she is performed by a real person.
Overview
DigitrevX, an American animator of anime-style 3D character models for VTubers, was commissioned to create Projekt Melody's original avatar. She is rendered in real time using the game engine Unity. She has purple and blue hair and an adhesive bandage on her nose, and her appearance was influenced by anime such as Ghost in the Shell and Hyperdimension Neptunia.
Melody claims to be an artificial intelligence, with her first appearance in July 2019 on Twitter involving her acting as a broken chat program that progressively developed sentience. She describes herself as "the first ... 3D rendered hentai camgirl."
Live streaming
Chaturbate
Projekt Melody hosted her first stream on Chaturbate on February 7, 2020. During the three days after this stream, her Twitter follower count increased from 700 to more than 20,000. While her streams are in progress, Melody uses a Bluetooth-enabled bullet vibrator that reacts to donations from viewers.
Twitch
On March 7, 2020, Melody made her live streaming debut on Twitch, where she was partnered before her first stream was broadcast. By the stream's end, she had over 50,000 followers.
On March 12, 2020, Twitch issued Melody a three-day suspension. Reddit users speculated on several possible reasons for her Twitch suspension, such as having a vibrator visible on her bed, skin becoming visible under her shirt when it clipped, linking to NSFW content, and hentai publisher Fakku providing sponsorship. On April 7, Twitch updated its nudity and attire policy, establishing new guidelines for acceptable levels of clothing coverage for all streamers on the website, including digital characters like Melody. On November 4, Twitch issued Melody a second suspension due to DigitrevX making a DMCA filing related to a copyright claim over Melody's usage of her model. The suspension was lifted the following day.
On November 24, 2020, Melody announced the launch of VShojo, one of the first Western VTuber talent agencies.
On September 24, 2021, Melody debuted a new Live2D-based character model.
Reception
Projekt Melody's popularity drew criticism from fellow webcam models, who argued that she does not experience the same degree of vulnerability as human models, and questioned if she belonged on Chaturbate. Projekt Melody subreddit moderator "jyl5555" said that fans enjoy the "wittiness and absurdity of Melody as a concept".
Awards and nominations
See also
Internet celebrity
Ironmouse
References
External links
Animated characters introduced in 2019
Fictional pansexuals
Fictional pornographic film actors
Hentai creators
Living people
American pornographic film actresses
Sexuality and computing
American Twitch (service) streamers
Unidentified people
VShojo
Year of birth missing (living people)
YouTube channels launched in 2019
VTubers | Projekt Melody | [
"Technology"
] | 722 | [
"Computing and society",
"Sexuality and computing"
] |
63,160,697 | https://en.wikipedia.org/wiki/Uprifosbuvir | Uprifosbuvir (MK-3682) is an antiviral drug developed for the treatment of hepatitis C. It is a nucleotide analogue which acts as an NS5B RNA polymerase inhibitor. it was in Phase III human clinical trials.
In 2017 owner Merck wrote down the value of uprifosbuvir to US$240 million, for a write-down of $2.9 billion, reducing its earnings per share from 42¢ to a loss of 22¢ for the fourth quarter of 2016. This was attributed to the hepatitis C drug market rather than uprifosbuvir itself; the population of treatable patients diminished rapidly after the introduction in 2014 of sofosbuvir and the combination ledipasvir/sofosbuvir, drugs that cured hepatitis C, and whose market was also diminishing following their success in curing patients. Clinical testing of uprifosbuvir continued.
References
Anti–RNA virus drugs
Antiviral drugs | Uprifosbuvir | [
"Biology"
] | 207 | [
"Antiviral drugs",
"Biocides"
] |
63,163,105 | https://en.wikipedia.org/wiki/Valerie%20Charlton | Valerie Charlton made props, models and special effects for movies in the 1970s and 1980s, especially those by the Monty Python troupe and Terry Gilliam.
Her partner was Julian Doyle, who also worked on many of the same movies.
Productions and works
The Holy Hand Grenade of Antioch, dragon boat prow, Black Knight's tent and Trojan rabbit in Monty Python and the Holy Grail (1975)
Jabberwocky (1977)
Monty Python's Life of Brian (1980)
Time Bandits (1981)
The Landstriders in The Dark Crystal (1982)
Monty Python's The Meaning of Life (1983)
the winged model of Sam Lowry – the protagonist of Brazil (1985)
Hoggle and Riding Goblins in Labyrinth (1986)
Who Framed Roger Rabbit (1988)
The Adventures of Baron Munchausen (1988)
References
Model makers
Monty Python
Prop designers
Special effects people
Year of birth missing | Valerie Charlton | [
"Physics"
] | 181 | [
"Model makers"
] |
63,164,437 | https://en.wikipedia.org/wiki/N95%20respirator | An N95 respirator is a disposable filtering facepiece respirator or reusable elastomeric respirator filter that meets the U.S. National Institute for Occupational Safety and Health (NIOSH) N95 standard of air filtration, filtering at least 95% of airborne particles that have a mass median aerodynamic diameter of 0.3 micrometers under 42 CFR 84, effective July 10, 1995. A surgical N95 is also rated against fluids, and is regulated by the US Food and Drug Administration under 21 CFR 878.4040, in addition to NIOSH 42 CFR 84. 42 CFR 84, the federal standard which the N95 is part of, was created to address shortcomings in the prior United States Bureau of Mines respirator testing standards, as well as tuberculosis outbreaks, caused by the HIV/AIDS epidemic in the United States. Since then, N95 respirator has continued to be used as a source control measure in various pandemics that have been experienced in the United States and Canada, including the 2009 swine flu and the COVID-19 pandemic, and has been recommended by the EPA for protection against wildfire smoke.
The N95 respirator is commonly made of a fine mesh of synthetic polymer fibers, specifically a nonwoven polypropylene fabric. It is produced by melt blowing and forms the inner filtration layer that filters out hazardous particles. However, the N95 standard does not preclude alternative means of filtration, so long as the respirator meets N95 standards and is approved by NIOSH.
"N95" is a trademark of the United States Department of Health and Human Services. It is illegal in the United States to use the term "N95" without the approval of NIOSH.
Regulation
The N95 standard does not require that the respirator be resistant to oil; two other standards, R95 and P95, add that requirement. The N95 type is the most common filtering facepiece respirator. Current filters are an example of a mechanical filter respirator, which provides protection against particulates but not against gases or vapors. An authentic N95 respirator is marked with the text "NIOSH" or the NIOSH logo, the filter class ("N95"), and, for most filtering facepiece respirators (respirators with non-replaceable filters), a "TC" approval number of the form 84A-####, the approval number. All N95 respirators, regardless of type, must be listed on the NIOSH Certified Equipment List (CEL) or the NIOSH Trusted-Source page, and it must have headbands instead of ear loops.
N95 respirators are considered similar to other respirators regulated under non-U.S. jurisdictions, but slightly different criteria are used to certify their performance, such as the filter efficiency, test agent and flow rate, and permissible pressure drop. For example, FFP2 respirators of the European Union are required to meet at least 94% filtration, and KN95 respirators of China are expected to meet at least 95% filtration. However, NIOSH found that some products labeled "KN95" failed to meet these standards, some of them filtering out as little as one percent. Both the U.S. Food and Drug Administration and Health Canada require such KN95 products failing to meet the filtration standards to be re-labeled as "face masks" instead of "respirators", when being sold in the U.S. and Canada.
History
Early US respirator standards
Prior to the 1970s, respirator standards were under the purview of the US Bureau of Mines (USBM). An example of an early respirator standard, Type A, established in 1926, was intended to protect against mechanically generated dusts produced in mines. These standards were intended to obviate miner deaths, noted to have reached 3,243 by 1907. However, prior to the Hawks Nest Tunnel Disaster, these standards were merely advisory, as the USBM had no enforcement power at the time. After the disaster, an explicit approval program was established in 1934, along with the introduction of combination Type A/B/C respirator ratings, corresponding to Dusts/Fumes/Mists respectively, with Type D blocking all three, under 30 CFR 14 Schedule 21.
The Federal Coal Mine Health and Safety Act establishing MESA (later MSHA), the Occupational Safety and Health Act of 1970, establishing NIOSH, as well as other regulations established around the time, reshuffled regulatory authority for respirators, and moved regulations from Part 14 to Part 11 by 1972, but nonetheless continued the use of USBM-era regulations.
42 CFR 84
Historically, respirators in the US had generally been approved by MESA/MSHA/NIOSH under federal regulation 30 CFR 11. Plans for overhauling Part 11 regulations had been discussed since the late 1980s, with the first proposed rule being published in the Federal Register on August 27, 1987. From the start, respirator regulations were planned to be moved from Title 30 to Title 42, Part 84 in the Code of Federal Regulations, along with the elimination of joint-approval between NIOSH and MSHA. Respirator assigned protection factors were also to be updated, along with chemical cartridge requirements.
TB outbreak during the HIV epidemic
In 1992, the multidrug-resistant tuberculosis task force within the CDC was tasked with reducing the incidences of hospital acquired TB infections. TB infections had traditionally occurred mainly in underserved groups and areas, as well as the very young and elderly, but regardless, usually had around a 10% chance of turning into an active TB infection in a given person's lifetime. However, HIV/AIDS, (where the outbreak in the US was in full force at the time) was noted to be one of the strongest factors for TB activation, since most TB outbreaks and mortalities reported at the time involved healthcare workers and patients infected with HIV. Respiratory protection and the performance of respirators were emphasized in the 1994 guidelines to controlling TB, which, at the time, were limited to respirators equipped with HEPA filters.
To quickly address the HEPA-only respirator requirement for TB controls, stemming from the lack of biological protection in the existing 30 CFR 11 standards (which were mainly designed for miners), NIOSH aimed to have the proposed 42 CFR rule changes finished by the end of 1994. The proposal at the time would drop the HEPA classification for non-powered respirators, and add three respirator types, at the time called Type A, B and C, with filtration efficiencies of greater than or equal to 99.97%, 99%, and 95% respectively, with Type C corresponding to the current N95 standard.
According to NIOSH, all the new respirator types proposed in 42 CFR 84, including Type C (later N95), would meet the CDC's requirement for protection against TB, and would provide avenues for cheaper NIOSH-approved respirators without the need for HEPA or NIOSH class-100 filters.
After the passage of 42 CFR 84, a 1999 NIOSH guide for health care administrators noted that respirators selected for TB prevention under 42 CFR would likely be N95 respirators.
Approval of Part 84 and replacement of 30 CFR 11
On July 10, 1995, in response to respirators exhibiting "low initial efficiency levels", new 42 CFR 84 standards, including the N95 standard, were enforced under a three-year transition period, ending on July 10, 1998. The standard for N95 respirators includes, but is not limited to, a filtration of at least 95% under a 0.3 micrometer 200 milligram test load of sodium chloride. Standards and specifications are also subject to change.
Once 42 CFR 84 was in effect, MSHA, under a proposed rule change to 30 CFR 11, 70, and 71, would withdraw from the approval process of rated respirators (outside of respirators used for mining).
Use
Voluntary respirator use
When in an environment where no designated hazards are present, OSHA mandated respirator requirements are limited to Appendix D of 1910.134. Voluntary respirator users under Appendix D are only obligated to follow manufacturer instructions for maintenance, use, and warnings, and to keep track of the respirator. OSHA encourages the use of respirators, even if only voluntarily.
OSHA advises voluntary respirator users receive a copy of 1910.134 Appendix D, as well as verify that the respirator used, be it powered-air purifying, self-contained, or facepiece-filtering, is not a potential health hazard.
During wildfires
The EPA recommends wearing a N95 or P100 respirator during a wildfire for protection against smoke. Masks to avoid are those with a single strap (also known as a dust mask) or a mask with earloops.
In addition to recommending NIOSH-approved respirators, the EPA also recommends building air purifiers to improve indoor air quality when commercial air purifiers are unavailable or unaffordable.
NIOSH is in the process of developing a hazard review on smoke exposure among outdoor workers. The current draft, advises the use of N95 respirators, as well as engineering and administrative controls.
When mandated by United States employers
Fit testing is a critical component to a respiratory protection program whenever workers use tight-fitting respirators in a hazardous environment. OSHA (US) requires an initial respirator fit test to identify the right model, style, and size respirator for each worker; as well, as annual fit tests. Additionally, tight-fitting respirators, including the N95, require a user seal check each time one is put on. Facial hair at the sealing area of the respirator will cause it to leak.
When use of a respirator is mandated by an employer, OSHA regulations require a medical evaluation. In the United States medical evaluation is required once, prior to initial fit testing and use, although it may need to be repeated if any adverse signs or symptoms are observed. Correct use of the respirator decreases the chances of airborne contamination by viruses.
For persons who are medically disqualified from negative-pressure respirators, or who cannot pass a fit test due to facial hair or other reasons, a powered air-purifying respirator is a possible alternative.
In industry
N95 respirators are also designed for industrial use in sectors such as mining and construction. They have also been shown to be effective as protection against engineered nanoparticles.
According to the NIOSH Respirator Selection Logic, respirators with filters in the N, R, and P series are recommended for concentrations of hazardous particulates that are greater than the relevant occupational exposure limit but less than the immediately dangerous to life or health level and the manufacturer's maximum use concentration, subject to the respirator having a sufficient assigned protection factor.
N series respirators, including the N95 respirator, are only effective in the absence of oil particles, such as lubricants, cutting fluids, or glycerine. For substances hazardous to the eyes, a respirator equipped with a full facepiece, helmet, or hood is recommended. They are not effective during firefighting, in oxygen-deficient atmosphere, or in an unknown atmosphere; in these situations a self-contained breathing apparatus is recommended instead. They are not effective against hazardous gases or vapors, for which a cartridge respirator is recommended.
In industrial settings where infectious disease exposure is not a concern, users can wear and reuse a filtering facepiece respirator until it is damaged, soiled, or causing noticeably increased breathing resistance, unless there is a manufacturer-specified duration of use. However, in laboratories at biosafety level 2 and higher, respirators are recommended to be discarded as hazardous waste after a single use.
Some industrial N95 series respirators have an exhaust valve to improve comfort, making exhalation easier, reducing leakage on exhalation and steaming-up of glasses. Research has indicated that wearing a valved N95 respirator does provide some source control to prevent the spread of diseases like COVID-19 when worn by asymptomatic infected users, at a level similar to that of a surgical or cloth facemask, although it is not equivalent to the performance of unvalved respirators. The same study found that "[m]odifications [such as the use of an electrocardiogram pad or surgical tape secured over the valve from the inside of the FFR] [...] can further reduce particle emissions".
In healthcare
Respirators used in healthcare are traditionally a specific variant called a surgical respirator, which is both approved by NIOSH as a respirator and cleared by the Food and Drug Administration as a medical device similar to a surgical mask. These may also be labeled "Surgical N95", "medical respirators", or "healthcare respirators". The difference lies in the extra fluid-resistant layer outside, typically colored blue. In addition to 42 CFR 84, surgical N95s are regulated under FDA regulation 21 CFR 878.4040.
In the United States, the Occupational Safety and Health Administration (OSHA) requires healthcare workers who are expected to perform patient activities with those suspected or confirmed to be infected with COVID-19 to wear respiratory protection, such as an N95 respirator. The CDC recommends the use of respirators with at least N95 certification to protect the wearer from inhalation of infectious particles including Mycobacterium tuberculosis, avian influenza, severe acute respiratory syndrome (SARS), pandemic influenza, and Ebola.
Unlike a respirator, a surgical mask is designed to provide barrier protection against droplets and does not have an air-tight seal and thus does not protect its wearer against airborne particles such as virus material to the same extent.
Use during shortages
During crisis situations where there is a shortage of N95 respirators, such as the COVID-19 pandemic, the U.S. Centers for Disease Control and Prevention (CDC) has recommended strategies for optimizing their use in healthcare settings. N95 respirators can be used beyond their manufacturer-designated shelf life, although components such as the straps and nose bridge material may degrade, making it particularly important that the wearer perform the expected seal check. N95 respirators can be reused a limited number of times after being removed, as long as they have not been used during aerosol-generating procedures and are not contaminated with patients' bodily fluids, because this increases the risk of surface contamination with pathogens. The respirator manufacturer may recommend a maximum number of donnings or uses; if no manufacturer guidance is available, preliminary data suggests limiting to five uses per device. Respirators approved under standards used in other countries and are similar to NIOSH-approved N95 respiratorsincluding FFP2 and FFP3 respirators regulated by the European Unioncan be used.
According to NIOSH, respirators may still be used in crisis situations if standard respirator fit testing is not available, as a respirator will still provide better protection than a surgical mask or no mask. In this case, best practices for getting a good face seal include trying different models or sizes, using a mirror or asking a colleague to check that the respirator is touching the face, and doing multiple user seal checks.
Given that the global supply of personal protective equipment (PPE) may be insufficient during a pandemic, in 2020, the World Health Organization recommended minimizing the need for PPE through telemedicine; physical barriers such as clear windows; allowing only those involved in direct care to enter a room with a COVID-19 patient; using only the PPE necessary for the specific task; continuing use of the same respirator without removing it while caring for multiple patients with the same diagnosis; monitoring and coordinating the PPE supply chain; and discouraging the use of masks for asymptomatic individuals.
When it is no longer possible for all healthcare workers to wear N95 respirators when caring for a COVID-19 patient, the CDC recommends that respirators be prioritized for workers performing aerosol-generating procedures on symptomatic persons, and those within three feet of an unmasked symptomatic person. Under these conditions, masking of symptomatic patients with at least a surgical mask and maintaining distance from the patient are particularly important to reduce the risk of transmission. When no respirators are left, workers who are at higher risk for severe illness may be excluded from caring for patients, and workers who have clinically recovered from COVID-19 may be preferred to care for patients. Portable fans with HEPA filters may also be used to increase ventilation in isolation rooms when surgical masks are being used in place of respirators. If neither respirators nor surgical masks are available, as a last resort, it may be necessary for healthcare workers to use masks that have never been evaluated or approved by NIOSH or homemade masks, such as cloth face masks, although caution should be exercised when considering this option.
Decontamination
Disposable filtering facepiece respirators such as N95 respirators are not approved for routine decontamination and reuse as standard of care. However, their decontamination and reuse may need to be considered as a crisis capacity strategy to ensure continued availability.
There have been efforts to evaluate cleaning methods for respirators in emergency shortages, although there is concern that this may reduce filter performance, or affect mask fit by deforming the mask. Duke University researchers have published a method for cleaning N95 respirators without damaging them using vaporized hydrogen peroxide to allow reuse for a limited number of times. Battelle received an Emergency Use Authorization from the U.S. Food and Drug Administration for its technology used to sterilize N95 respirators.
OSHA does not currently have any standards for disinfecting N95 respirators. NIOSH recommends that during shortages N95 respirators may be used up to five times without cleaning them, as long as aerosol-generating procedures are not performed, and respirators are not contaminated with patients' bodily fluids. Contamination can be reduced by wearing a cleanable face shield over an N95 respirator, as well as using clean gloves when donning and seal-checking a used N95 respirator and discarding the gloves immediately after. According to CDC, ultraviolet germicidal irradiation, vaporous hydrogen peroxide and moist heat showed the most promise as potential methods to decontaminate N95 respirators and other filtering facepiece respirators.
Contrast with surgical mask
A surgical mask is a loosely-placed, unsealed barrier, meant to stop droplets, and other liquid-borne particles from the mouth and nose that may contain pathogens.
A surgical mask may not block all particles, due to the lack of fit between the surface of the face mask and the face. The filtration efficiency of a surgical mask ranges between 10% and 90% for any given manufacturer, when measured using tests required for NIOSH certification. A study found that 80–100% of subjects failed an OSHA-accepted qualitative fit test, and a quantitative test showed between 12 and 25% leakage.
A CDC study found that in public indoor settings, consistently wearing a respirator was linked to a 83% lower risk of testing positive for COVID-19, as compared to a 66% reduction when using surgical masks, and 56% for cloth.
Later history
HIV/AIDS and TB epidemic
While NIOSH was busy finishing 42 CFR 84 respirator regulations (including the N95), other agencies and groups (such as the SEIU) were advocating for new standards for the prevention of TB. In 1992, the Labor Coalition to Fight TB in the Workplace started lobbying OSHA to create advisories and formal rules to protect workers from TB. The group was especially concerned about the rise of multidrug-resistant tuberculosis, which would require more rigorous standards to mitigate, especially since they felt that the 1990 CDC guidelines for TB were not being properly followed. The CDC eventually revised and released new TB guidelines in 1994, and in 1995 and 1996, meetings started to be held between OSHA and various stakeholders for a new TB standard, borrowing heavily from the CDC's work.
In 1997, OSHA proposed new rule changes for industries affected by the spread of tuberculosis, like hospitals, where many patients infected with TB were also infected with HIV. The proposed rule would require signage that includes a STOP sign, with red background, white symbols, and a set of words warning people to wear "N95 or more protective" respirators (under 42 CFR 84) near isolation rooms where TB infection is likely. Additional notices could be added at the discretion of an employer, so long as it did not contradict the required wording.
OSHA withdrew the proposal in 2003, owing to commenters and reviewers pointing to a likely overstating of risk, declining rates of TB in the years following the proposal, as well as compliance without a rule by OSHA.
Shortages from expanding asbestos litigation
SARS pandemic
In 2003, in response to the SARS outbreak, the United States CDC advised healthcare workers to wear N95 respirators. Despite this advice, a patient who had traveled from Ontario exposed six healthcare workers in Pennsylvania following contact tracing by the CDC, though fitted N95 respirators were worn at a hospital upon suspicion of SARS.
Following the SARS outbreak in the US, US Senate hearings started to be held proposing the Strategic National Stockpile start stocking PPE and N95 respirators in the event of another SARS outbreak. It was noted at the time that there were few N95 respirator manufacturers, potentially exacerbating a shortage in a crisis.
Meanwhile, in Canada, discussions with Ontario EMS and New York Department of Health in 2004 noted that infected emergency medical personnel failed to properly use N95 respirators. According to Ontario SARS commission final report, this was likely due to confusion over infectious disease control, confusion over respirator procedures, and the insinuation by various infection control practitioners that N95 respirators were not necessary. However, the report concludes, from laws preceding SARS, healthcare workers were obligated to wear N95 respirators throughout the outbreak, despite suggestions to the contrary. A paper published in the New England Journal of Medicine concluded that universal use of N95 respirators, as well as additional infection control measures, ended the SARS outbreak in Ontario.
2007 CDC/HICPAC infection control guidelines
H1N1 swine flu pandemic
In May 2009, in response to the H1N1 swine flu outbreak, the CDC authorized the release of N95 respirators from the Strategic National Stockpile, and the waiving of certain quality controls on certain models of newly manufactured N95 respirators, provided they were documented "for use during the swine flu emergency". Initially, the CDC's interim guide for H1N1 recommended N95 respirators for the prevention of H1N1, but stopped short of recommending respirators for groups not deemed "at increased risk of severe illness from influenza", except for occupational use in healthcare. NIOSH also emphasized the differences in fit between an N95 respirator and a surgical mask for prevention against the flu.
For those in the general public wishing to wear N95 respirators, properly wearing a N95 was noted to be difficult, but the tendency for people to distance themselves from those wearing masks was said to compliment the six-foot social distancing rules at the time.
H1N1 respirator/mask randomized control trials
Around the time of the H1N1 pandemic, randomized control trial studies of masks started being done, comparing surgical masks and N95 respirators with the tendency for medical staff to be infected by the flu. One paper concluded that N95s were better than surgical masks, but its results were later called into question. Another paper claimed that protection provided by an N95 respirator compared similarly to a surgical mask, but the study did not control health care personnel potentially being exposed outside, without respirators, via the community.
After the 2009 H1N1 flu season, the CDC issued guidelines recommending surgical masks instead, after complaints were leveled by various groups on the effectiveness of surgical masks compared to N95 respirators, along with complaints about comfort. The new recommendations were met with approval by groups like the Society for Healthcare Epidemiology of America.
COVID-19 pandemic
During the COVID-19 pandemic, the mask and respirator market rapidly grew, along with counterfeit respirators. NIOSH, on behalf of the Department of Health and Human Services, filed a trademark application on June 17, 2020, for various 42 CFR 84 trademarks, including the N95, allowing NIOSH to enforce rules on counterfeit masks outside of rules defined in 42 CFR 84. The trademarks were registered in 2022.
Global shortages during the COVID-19 pandemic
The Strategic National Stockpile had not been refilled following the H1N1 pandemic, and by April 2020, Department of Homeland Security officials reported that the supply of respirators and other PPE in the stockpile was nearly gone. Respirators came to be in short supply and high demand during the COVID-19 pandemic, causing price gouging and hoarding, often leading to confiscation of masks. Production of N95 respirators was limited due to constraints on the supply of nonwoven polypropylene fabric as well as the cessation of exports from China.
Also in early April 2020, the United States federal government, invoking the DPA, ordered 3M to stop exporting N95 respirators to customers in Canada and Latin America, and to keep them within the U.S. instead. However, 3M refused, saying: "Ceasing all export of respirators produced in the United States would likely cause other countries to retaliate and do the same, as some have already done. If that were to occur, the net number of respirators being made available to the United States would actually decrease. That is the opposite of what we and the administration, on behalf of the American people, both seek."
Dropping of mask mandates in hospitals
Criticism of N95 RCTs and other controversial studies
Following previous H1N1 randomized control trials comparing N95s and surgical masks, new RCTs were published. Major flaws were noted, including contraction of virus outside hospital, the lack of controls over time in hospital, and assumptions made about transmission via droplets instead of aerosols.
In addition, in 2024, a paper published in the American Society for Microbiology Clinical Microbiology Reviews stated there were harms in continued undue weight being placed on RCTs and flawed mask studies in a social and political context, as retracted papers continue to be circulated to justify certain masking behaviors and beliefs. One retracted JAMA paper garnered a million views, while another retracted paper in Frontiers Public Health continues to circulate across social media.
H5N1 outbreak
Among dairy workers
The CDC recommends farm workers wear PPE, including N95 or better respirators, when working with farm animals potentially infected with H5N1. However, outbreaks of H5N1 have continued among dairy workers, likely due to workers' fear of retaliation by their employers, and reluctance by employers and state officials to allow CDC investigators into dairy farms.
Selected patents
Marketed by AlphaProTech as 'Magic Arch.'
'Duckbill' style
See also
Air purifier
Corsi–Rosenthal Box
Division of Industrial Hygiene
NIOSH
Respirator assigned protection factors
Permissible exposure limit
Source control (respiratory disease)
Toxic tort
Face masks during the COVID-19 pandemic
Face masks during the COVID-19 pandemic in the United States
Impact of the COVID-19 pandemic on neurological, psychological and other mental health outcomes
Workplace hazard controls for COVID-19
Notes
References
Further reading
Previous versions of this article included the claim implying that Peter Tsai invented the N95, from this edit to this edit. Peter Tsai is nowhere to be found in the NIOSH publications here, linked on Wikisource, or in any Federal Register document linked in the references above. For more information, see the talk page (mobile link).
External links
Federal Register entry for 42 CFR 84
Q & A—Masks and COVID-19 by the WHO
NIOSH Certified Equipment List
1995 introductions
Medical masks
Respirators
Medical hygiene
Medical devices
Occupational safety and health
National Institute for Occupational Safety and Health | N95 respirator | [
"Biology"
] | 6,205 | [
"Medical devices",
"Medical technology"
] |
63,164,704 | https://en.wikipedia.org/wiki/Nathaniel%20J.%20Fisch | Nathaniel Joseph Fisch is an American plasma physicist known for pioneering the excitation of electric currents in plasmas using electromagnetic waves, which was then used in tokamak experiments. This contributed to an increased understanding of plasma wave–particle interactions in the field for which he was awarded the James Clerk Maxwell Prize for Plasma Physics in 2005 and the Hannes Alfvén Prize in 2015.
Fisch's research also involve inertial fusion, as well as methods to generate intensive laser fields to accelerate particles, such as the ones used in plasma thrusters. He is also known to have worked on the hydrodynamics of charged liquids, petroleum refinement, and pattern recognition.
Early life and career
Fisch studied at the Massachusetts Institute of Technology (as MIT National Scholar 1968 to 1972), where he received his bachelor's and master's degree in 1972 and 1975 respectively, and received his doctorate in computer science and electrical engineering in 1978. From 1978, he was a scientist in the plasma physics laboratory at Princeton University, where he has been a professor in the Faculty of Astrophysics since 1991 (also associated with the Faculty of Mechanics and Flight Engineering since 2000) and heads the University's Plasma Physics Program. In 1986, he was a visiting scientist at IBM's Thomas J. Watson Research Center. From 1981 to 1986, he was a consultant at Exxon Research.
Honors and awards
Fisch was awarded the Guggenheim Fellowship in 1985. He was then elected a fellow of the American Physical Society in 1987, and was subsequently awarded the John Dawson Award for Excellence in Plasma Physics Research in 1992 for fundamental theoretical work on non-inductive power generation in toroidally enclosed plasmas.
In 2004, he received the Ernest Orlando Lawrence Award.
In 2005, he received the James Clerk Maxwell Prize for Plasma Physics for "theoretical development of efficient radio frequency (RF)-driven current in plasmas and for greatly expanding our ability to understand, to analyze, and to utilize wave–plasma interactions."
In 2015, he was awarded the Hannes Alfvén Prize from the European Physical Society for "his contributions to the understanding of plasma wave–particle interactions and their applications to efficiently driving currents with radio-frequency waves."
References
American plasma physicists
Fellows of the American Physical Society
1950 births
Living people
MIT School of Engineering alumni
Plasma physicists | Nathaniel J. Fisch | [
"Physics"
] | 472 | [
"Plasma physicists",
"Plasma physics"
] |
63,165,435 | https://en.wikipedia.org/wiki/Halicin | Halicin (SU-3327) is an experimental drug that acts as an enzyme inhibitor of c-Jun N-terminal kinase (JNK). Originally, it was researched for the treatment of diabetes, but development was discontinued for this application due to poor results in testing. In 2019, this molecule was found by an artificial intelligence (AI) model to show antibiotic properties against a number of bacteria.
History
Halicin was previously known as SU-3327, developed by a group of researchers from Burnham Institute for Medical Research, United States in 2009 for investigations into diabetes treatment.
Researchers named the molecule after the fictional artificial intelligence system Hal from 2001: A Space Odyssey.
Antibiotic properties
Halicin was identified by artificial intelligence researchers, including bioengineer James Collins, at the MIT Jameel Clinic in 2019 using an in silico deep learning approach, as a likely broad-spectrum antibiotic. The process took just three days. This likelihood was verified by in vitro cell culture testing, followed by in vivo tests in mice. It showed activity against drug-resistant strains of Clostridiodes difficile, Acinetobacter baumannii, and Mycobacterium tuberculosis, with an unusual mechanism of action involving the sequestration of iron inside the bacterial cells, that thereby interferes with their ability to regulate the pH balance across the cell membrane properly. Since this is a different mode of action from most antibiotics, halicin retained activity against bacterial strains resistant to many commonly used drugs.
Preliminary studies suggest that halicin kills bacteria by disrupting their ability to maintain an electrochemical gradient across their cell membranes. This gradient is necessary, among other functions, to produce adenosine triphosphate (ATP, molecules that cells use to store and transfer energy), so if the gradient breaks down, the cells die. This type of killing mechanism could be difficult for bacteria to develop resistance to.
References
External links
Machine Learning for Antibiotics
Enzyme inhibitors
Antibiotics
Nitrothiazoles
Thiadiazoles | Halicin | [
"Biology"
] | 416 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
63,165,747 | https://en.wikipedia.org/wiki/%28Cyclooctatetraene%29iron%20tricarbonyl | (Cyclooctatetraene)iron tricarbonyl is the organoiron compound with the formula (C8H8)Fe(CO)3. Like other examples of (diene)Fe(CO)3 complexes, it is an orange, diamagnetic solid. Although several isomers are possible, only the η4-C8H8 complex is observed. The complex is an example of a ring-whizzer, since, on the NMR time-scale, the Fe(CO)3 center migrates around the rim of the cyclooctatetraene ligand.
References
Carbonyl complexes
Organoiron compounds
Half sandwich compounds
Iron(0) compounds | (Cyclooctatetraene)iron tricarbonyl | [
"Chemistry"
] | 145 | [
"Organometallic chemistry",
"Half sandwich compounds"
] |
63,165,844 | https://en.wikipedia.org/wiki/Cumulus%20Association | The Cumulus Association is a global association of higher education institutions in the fields of art, design, and media. Currently, there are 350 members from 60 countries.
Cumulus was founded in 1990 by the Aalto University School of Arts, Design and Architecture in Finland and the Royal College of Art in London in cooperation with the Danish Design School, Gerrit Rietvelt Academy, University of Duisburg-Essen and University of Applied Arts Vienna. The network was established to coordinate collaboration between schools, and to facilitate student and teacher exchange within the European Union Erasmus programme. The network was transferred to Cumulus Association in 2001.
In the last 30 years, Cumulus has become a global association that organizes biannual conferences and initiates projects and workshops with member institutions. Their aim is to improve the quality of art, design, and media education and to help students, professors, and other faculty members work internationally. In addition to academic collaboration, Cumulus facilitates collaboration with businesses, public institutions, and governments with an interest in art and design education and research.
To stimulate design actions, projects, and research leading to a more sustainable society, Cumulus representatives signed the Kyoto Design Declaration in March 2008. To implement the ideals of the Declaration, the Cumulus Green Award was established. Cumulus Green is an international award focused on cultivating and leading global cultures, societies, and industries towards more ecological and responsible solutions.
References
Arts organizations established in 1990
Art and design organizations
Educational institutions established in 1990 | Cumulus Association | [
"Engineering"
] | 302 | [
"Design",
"Art and design organizations"
] |
63,166,908 | https://en.wikipedia.org/wiki/SOMM%20TV | SOMM TV is a food and wine streaming network launched in 2019.
The network shows original films, such as SOMM, SOMM: Into the Bottle, SOMM 3, and The Delicacy as well as original series productions and educational content. It also shows licensed wine and food content such as Bottle Shock and Supersize Me.
Verticals, which features vintages that defined a winery or winemaker, premiered at the Napa Valley Film Festival in fall 2019. In 2021 the service released a documentary titled Verticals: Lafite Rothschild. The program is narrated by Éric and Saskia de Rothschild.
In April 2020, the documentary A Chef's Voyage, which had been slated for a traditional release, instead premiered on SOMM with rental fees going to the LEE Initiative's Restaurant Workers Relief Program to support those laid off because of the COVID pandemic.
In 2021 it released a new reality TV competition show, Sparklers. It was nominated for a 2022 James Beard Foundation Award in the Reality or Competition Visual Media category. Production was set to begin on a second season in spring 2023 with Joel McHale as a guest judge.
In February 2022, it premiered Saving The Restaurant, which followed Colorado restaurateur Bobby Stuckey as he tried to help restaurants avoid closure during the pandemic. When Stuckey's own restaurants close, Stuckey helped form the Independent Restaurant Coalition.
In June 2022 it premiered The Whole Animal. It won a James Beard Award in 2023 in the Visual Media - Long form category.
In July 2022 it released Auction Lot 288, the story of the world's most expensive Champagne, featuring a bottle of 1874 Perrier-Jouët.
The Oldest Vine was released in December 2022 and tells the story of a more than 200 year old vine, still producing wine in Los Angeles at Mission San Gabriel.
References
Wine websites | SOMM TV | [
"Technology"
] | 385 | [
"Computing stubs",
"World Wide Web stubs"
] |
63,167,039 | https://en.wikipedia.org/wiki/%28Z%29-6-Dodecen-4-olide | (Z)-6-Dodecen-4-olide is a volatile, unsaturated lipid and γ-lactone found in dairy products, and secreted as a pheromone by some even-toed ungulates. It has a creamy, cheesy, fatty flavour with slight floral undertones in small concentrations, but contributes towards the strong, musky smell of a few species of antelope and deer in higher concentrations.
Function
(Z)-6-Dodecen-4-olide is believed to play a part in olfactory communication between individuals of the Columbian black-tailed deer (Odocoileus hemionus columbianus), and is secreted into urine during a rut. (Z)-6-Dodecen-4-olide is then deposited onto the tuft of hair making up the tarsal gland of the deer, as the urine runs down the gland, during a behavior called rub-urination. Similarly, it has also been identified in secretions of the interdigital and pedal glands of the bontebok (Damaliscus pygargus) and the blesbok (Damaliscus pygargus phillipsi) where it is believed to play a role in carrying information about the dominance status, sex, health condition and possibly other characteristics of the animal it came from. The (Z)-6-dodecen-4-olide is replenished daily to maintain the pungent smell. It has also been isolated from Polianthes tuberosa, a perennial plant used in the perfume industry since the 17th century for its powerful floral scent.
References
Lactones
Unsaturated compounds | (Z)-6-Dodecen-4-olide | [
"Chemistry"
] | 354 | [
"Organic compounds",
"Unsaturated compounds"
] |
63,169,268 | https://en.wikipedia.org/wiki/Modes%20of%20variation | In statistics, modes of variation are a continuously indexed set of vectors or functions that are centered at a mean and are used to depict the variation in a population or sample. Typically, variation patterns in the data can be decomposed in descending order of eigenvalues with the directions represented by the corresponding eigenvectors or eigenfunctions. Modes of variation provide a visualization of this decomposition and an efficient description of variation around the mean. Both in principal component analysis (PCA) and in functional principal component analysis (FPCA), modes of variation play an important role in visualizing and describing the variation in the data contributed by each eigencomponent. In real-world applications, the eigencomponents and associated modes of variation aid to interpret complex data, especially in exploratory data analysis (EDA).
Formulation
Modes of variation are a natural extension of PCA and FPCA.
Modes of variation in PCA
If a random vector has the mean vector , and the covariance matrix with eigenvalues and corresponding orthonormal eigenvectors , by eigendecomposition of a real symmetric matrix, the covariance matrix can be decomposed as
where is an orthogonal matrix whose columns are the eigenvectors of , and is a diagonal matrix whose entries are the eigenvalues of . By the Karhunen–Loève expansion for random vectors, one can express the centered random vector in the eigenbasis
where is the principal component associated with the -th eigenvector , with the properties
and
Then the -th mode of variation of is the set of vectors, indexed by ,
where is typically selected as .
Modes of variation in FPCA
For a square-integrable random function , where typically and is an interval, denote the mean function by , and the covariance function by
where are the eigenvalues and are the orthonormal eigenfunctions of the linear Hilbert–Schmidt operator
By the Karhunen–Loève theorem, one can express the centered function in the eigenbasis,
where
is the -th principal component with the properties
and
Then the -th mode of variation of is the set of functions, indexed by ,
that are viewed simultaneously over the range of , usually for .
Estimation
The formulation above is derived from properties of the population. Estimation is needed in real-world applications. The key idea is to estimate mean and covariance.
Modes of variation in PCA
Suppose the data represent independent drawings from some -dimensional population with mean vector and covariance matrix . These data yield the sample mean vector , and the sample covariance matrix with eigenvalue-eigenvector pairs . Then the -th mode of variation of can be estimated by
Modes of variation in FPCA
Consider realizations of a square-integrable random function with the mean function and the covariance function . Functional principal component analysis provides methods for the estimation of and in detail, often involving point wise estimate and interpolation. Substituting estimates for the unknown quantities, the -th mode of variation of can be estimated by
Applications
Modes of variation are useful to visualize and describe the variation patterns in the data sorted by the eigenvalues. In real-world applications, modes of variation associated with eigencomponents allow to interpret complex data, such as the evolution of function traits and other infinite-dimensional data. To illustrate how modes of variation work in practice, two examples are shown in the graphs to the right, which display the first two modes of variation. The solid curve represents the sample mean function. The dashed, dot-dashed, and dotted curves correspond to modes of variation with and , respectively.
The first graph displays the first two modes of variation of female mortality data from 41 countries in 2003. The object of interest is log hazard function between ages 0 and 100 years. The first mode of variation suggests that the variation of female mortality is smaller for ages around 0 or 100, and larger for ages around 25. An appropriate and intuitive interpretation is that mortality around 25 is driven by accidental death, while around 0 or 100, mortality is related to congenital disease or natural death.
Compared to female mortality data, modes of variation of male mortality data shows higher mortality after around age 20, possibly related to the fact that life expectancy for women is higher than that for men.
References
Dimension reduction
Functional analysis
Matrix decompositions | Modes of variation | [
"Mathematics"
] | 914 | [
"Functional analysis",
"Functions and mappings",
"Mathematical relations",
"Mathematical objects"
] |
63,169,354 | https://en.wikipedia.org/wiki/Art%20Gallery%20Theorems%20and%20Algorithms | Art Gallery Theorems and Algorithms is a mathematical monograph on topics related to the art gallery problem, on finding positions for guards within a polygonal museum floorplan so that all points of the museum are visible to at least one guard, and on related problems in computational geometry concerning polygons. It was written by Joseph O'Rourke, and published in 1987 in the International Series of Monographs on Computer Science of the Oxford University Press. Only 1000 copies were produced before the book went out of print, so to keep this material accessible O'Rourke has made a pdf version of the book available online.
Topics
The art gallery problem, posed by Victor Klee in 1973, asks for the number of points at which to place guards inside a polygon (representing the floor plan of a museum) so that each point within the polygon is visible to at least one guard. Václav Chvátal provided the first proof that the answer is at most for a polygon with corners, but a simplified proof by Steve Fisk based on graph coloring and polygon triangulation is more widely known. This is the opening material of the book, which goes on to covers topics including visibility, decompositions of polygons, coverings of polygons, triangulations and triangulation algorithms, and higher-dimensional generalizations, including the result that some polyhedra such as the Schönhardt polyhedron do not have triangulations without additional vertices. More generally, the book has as a theme "the interplay between discrete and computational geometry".
It has 10 chapters, whose topics include the original art gallery theorem and Fisk's triangulation-based proof; rectilinear polygons; guards that can patrol a line segment rather than a single point; special classes of polygons including star-shaped polygons, spiral polygons, and monotone polygons; non-simple polygons; prison yard problems, in which the guards must view the exterior, or both the interior and exterior, of a polygon; visibility graphs; visibility algorithms; the computational complexity of minimizing the number of guards; and three-dimensional generalizations.
Audience and reception
The book only requires an undergraduate-level knowledge of graph theory and algorithms. However, it lacks exercises, and is organized more as a monograph than as a textbook. Despite warning that it omits some details that would be important to implementors of the algorithms that it describes, and does not describe algorithms that perform well on random inputs despite poor worst-case complexity, reviewer Wm. Randolph Franklin recommends it "for the library of every geometer".
Reviewer Herbert Edelsbrunner writes that "This book is the most comprehensive collection of results on polygons currently available and thus earns its place as a standard text in computational geometry. It is very well written and a pleasure to read." However, reviewer Patrick J. Ryan complains that some of the book's proofs are inelegant, and reviewer David Avis, writing in 1990, noted that already by that time there were "many new developments" making the book outdated. Nevertheless, Avis writes that "the book succeeds on a number of levels", as an introductory text for undergraduates or for researchers in other areas, and as an invitation to solve the "many unsolved questions" remaining in this area.
References
Computational geometry
Polygons
Mathematics books
1987 non-fiction books | Art Gallery Theorems and Algorithms | [
"Mathematics"
] | 708 | [
"Computational geometry",
"Computational mathematics"
] |
63,169,383 | https://en.wikipedia.org/wiki/Rashmi%20Robot | Rashmi is an Indian lip-syncing humanoid robot developed by Ranjit Shrivastava, a programmer from Ranchi, India.
History
This robot was launched on 1 August 2018, 2 years after the start of its development. Its development started as a hobby when Shrivastava's son challenged him after seeing a movie about robots. Ranjit worked alone, without a technical team or research lab.
Events
In India's Got Talent
This robot appeared in India's Got Talent season 8.
As Red FM RJ
Rashmi appeared on Red FM from December 3, 2018. The robot hosted an “Ask Rashmi” segment where it replied to listener's queries on radio. Robot Rashmi also hosted a show with RJ Raunac aka Baua in the morning from 10 AM to 11 AM and 'Dilli ke kadak launde' RJ Kisna and Ashish in the evening 5 to 6 p.m.
Gaganyaan Mission
Indian Space Research Organisation (Isro) approached the robot's developer to inquire about using it in uncrewed missions in preparation for India's first crewed mission in space, called Gaganyaan, in 2022. Two ISRO scientists, met Shrivastava to determine if the existing robot could be upgraded with certain simulated features resembling human physiology ISRO later developed their own Vyommitra robot for this purpose.
As guest in engineering colleges
Rashmi was invited to IIT, Delhi in December, 2018. Later Rashmi was invited in many engineering colleges as the guest of honour or chief guest including Government Engineering College, Amravati, College of Engineering, Pune, Veermata Jijabai Technological Institute Mumbai, IIITDM Kanchieeuram and Don Bosco College of Engineering, Mumbai
Features
The robot delivers lip-synced speech. It makes facial expressions and it can also move its neck in 6 axes. It can display 83 facial expressions. Rashmi can speak four languages - English, Hindi, Marathi and Bhojpuri.
Rashmi works on four layers including speech recognition, APIs and AI through which It interprets conversational moods. It has a camera built in the eyes with facial recognition, 3D Mapping and OCR. The Robot also has a functional hand with finger movement. Rashmi does not have legs.
References
Robots of India
Humanoid robots
Social robots | Rashmi Robot | [
"Technology"
] | 484 | [
"Social robots",
"Computing and society"
] |
63,170,349 | https://en.wikipedia.org/wiki/GS-6620 | GS-6620 is an antiviral drug which is a nucleotide analogue. It was developed for the treatment of Hepatitis C but while it showed potent antiviral effects in early testing, it could not be successfully formulated into an oral dosage form due to low and variable absorption in the intestines which made blood levels unpredictable. It has however continued to be researched as a potential treatment for other viral diseases such as Ebola virus disease.
References
Anti–RNA virus drugs
Antiviral drugs | GS-6620 | [
"Biology"
] | 103 | [
"Antiviral drugs",
"Biocides"
] |
63,171,454 | https://en.wikipedia.org/wiki/Maurice%20Jacob | Maurice René Michel Jacob ( – ) was a French theoretical particle physicist.
Biography
Maurice Jacob studied physics at École normale supérieure from 1953 to 1957. During a visit to the Brookhaven National Laboratory in 1959, he developed with Gian-Carlo Wick the helicity formalism for relativistic description of scattering of particles with spin and the decay of particles and resonant states. In 1961, he obtained a doctorate on this subject at the University of Paris. His thesis advisors were professors Francis Perrin and Gian-Carlo Wick. Jacob then moved, as a post-doctoral fellow, to Caltech. He worked in Saclay from 1961 to 1967. From 1967 he worked at CERN until his retirement in 1998. From 1982 to 1988, he headed the theoretical physics division of CERN and in the 1990s, he was responsible for CERN's relations with its Member States.
Maurice Jacob's research focuses on the phenomenology of strong interactions, including diffraction, scaling, high-transverse-momentum processes and the formation of quark–gluon plasma. In particular, he pioneered the studies of inclusive hadron-production processes, including scaling and its violations. He contributed also to the field of accelerator physics together with Tai Tsun Wu.
He supported Carlo Rubbia during the construction of the Super Proton Synchrotron (SPS) in the 1980s.
Jacob chaired the French Physical Society from 1985 to 2002 and from 1991 to 1993 he was president of the European Physical Society. In 1993, he became a member of the American Physical Society. He was co-editor of Physics Letters B and Physics Reports.
He was appointed member of the CNRS scientific council in 1988.
He was a corresponding member of the Academy of Sciences from 1977, member of the Swedish Royal Academies, Academia Europaea and also scientific advisor to the European Space Agency
Awards and honors
CNRS Silver Medal (1967)
Legion of Honour (1994)
Marriage and children
Maurice Jacob was married to Lise Jacob. Together they have 4 children Jimmy, Thierry, Francis, and Irène.
References
Particle physicists
French theoretical physicists
People associated with CERN
1933 births
2007 deaths
École Normale Supérieure alumni
Knights of the Legion of Honour
University of Paris alumni
Members of the French Academy of Sciences
Academic journal editors
20th-century French physicists
Members of Academia Europaea
21st-century French physicists
Scientists from Lyon
Presidents of the European Physical Society
Members of the Royal Swedish Academy of Sciences
Presidents of the Société Française de Physique
Fellows of the American Physical Society | Maurice Jacob | [
"Physics"
] | 517 | [
"Particle physicists",
"Particle physics"
] |
53,372,306 | https://en.wikipedia.org/wiki/Des%20Moines%20Water%20Works | The Des Moines Water Works (DMWW) is a publicly owned, municipal water utility with its headquarters in Water Works Park. It was founded 1871 southwest of downtown Des Moines, Iowa, along the Raccoon River and provides water to half a million residents of the greater Des Moines metropolitan area. , it has three treatment facilities.
In March 2015, the DMWW board sued three Iowa counties for violating the Clean Water Act with high nitrate discharges, which contribute to hypoxia in the Gulf of Mexico.
History
The Des Moines Water Works are a municipal water utility, owned by the about 500,000 residents of the greater Des Moines area, whom it supplies with water. It is Iowa´s largest water utility and among the largest 100 utilities in the country.
In 1871, Frederick M. Hubbell and Jefferson S. Polk organized the Des Moines Water Company with $3000. B. F. Allen, helped to raise $250,000 and became the company's first president. The company passed to Polk & Hubbell, and in 1880 to a joint-stock company, where a stockholder-elected board of five directors appointed a president, secretary, and one member, with the exclusive rights to operate the company for 40 years. The Water Company was built on Walnut Street in Des Moines using Holly system hydrants, which could throw six streams at a time. The city demanded 10 miles of pipe within 10 months and "hydrants were placed for citizens or passersby to draw water for purposes of drinking". Pumps discharged about 2 million gallons per day (mgd). In its first year from June 1872 through June 1873, the Water Works´ operating costs were $5,770 and consumers paid no city taxes for water use.
Water came from an iron filtering tank in the gravel and sand of the Raccoon River near the water's edge, 12 feet in diameter and 14 feet high, open at the bottom and closed at the top with perforations to let water in. The iron filters constantly plugged and after 10 years, in 1883, an infiltration gallery system to use groundwater along the river was planned, the first of its kind in the U.S. From 1884-1885, 750 feet of a wooden gallery were constructed, and the iron filters were abolished. A small primitive dam on the Raccoon River increased the water level near the gallery. In 1880, the name was changed to Des Moines Water Works Company. In 1891, the first water tower was constructed, holding 530,000 gallons of water, used until 1931, and torn down in 1939.
1900–1919
In the early 1900s, many people who died of typhoid, were those with private wells. In 1902, a new water gallery was begun out of large concrete rings 5 feet in diameter and 2 feet long, held slightly apart to allow water seeping in. Flooding delayed continuation until 1904 until completion in 1910.
In June 1903, a flood was then said to be "the worst in history" with business suspended, hundreds became unemployed and homeless. In 1910, ponds were constructed in the park began that could augment the water supply and in 1918, a pumping station built on the park pumped water from the river into the ponds.
From 1872 to 1919, "there were constant complaints by the city council and newspapers". The city tried to buy the Water Works, but either could not raise the funds or could not get the votes needed. In 1897, the newspaper and city council attacked water quality "to lower the company's asking price". In 1898, the people voted a proposal to buy the company down. In 1911, the vote passed, but Denman wouldn't sell at the price. Denman explained publicly why he could not accept the city's offer and how the city hadn't paid its water bills for several years. In 1911 the City passed an ordinance for standards of water purity. and in 1912 DMWW started adding hypochlorite and began a water testing laboratory with a chemist, a bacteriologist, and an assistant. In 1917, an outside source conducted a study on the conditions of the Des Moines river and Raccoon Rivers, where the main pollution of the latter "was said to come from nearby privies, sewage from upstream residents, septic tanks, and a car shop in Valley Junction". In 1913, a price agreement was reached and in 1914 a vote to purchase passed. The vote to issue bonds did not pass until November 1918, and at that unfavorable time for the bond market, the city could not sell enough bonds, and sued for an extension of time.
In 1919, the city bought the water company. The company's name was changed again to Des Moines Water Works (DMWW). It was formed as a public utility owned by ratepayers under a new Code of Iowa, Section 388. Charles Denman, who had been running the company since 1896, became General Manager with a salary of $8,000.
1920–1999
In 1920 a new pumping station at its present site began operation.
In 1923, an attorney prepared a bill for the legislature to abolish the City Councils supervision of the DMWW Board. The Board is responsible to run DMWW and the Mayor appoints Board members when vacancies occur with the City Council only approving the appointments.
In 1928, Denman recommended adding a softening plant to save customers money spent on soap and wear and tear on clothes. Arguments for and against it continued with the Board voting to delay building until 1938 and further delayed by World War II.
In 1929, the Hazen water tower, Des Moines only water tower, 110 feet high was constructed of concrete and steel, holding 2 million gallons of water.
In 1931, the benefit of fluoride in preventing tooth decay opened a controversy for three decades.
Between 1933 and 1935, during the Great Depression, about 3500 men could not pay their water bills, and Denman offered them work often for several days, laying water mains, grade park roads, inspect hydrants. Seven thousand plantings of trees and shrubs were made yearly from seedlings grown in the greenhouse.
In 1942, DMWW bought 650 acres of farmland southwest of Des Moines to build an emergency reservoir, the Dale Maffitt Reservoir, which was opened for fishing in 1948.
In 1945, another flood and in 1947 a record-breaking flood occurred.
From 1948-49, the softening plant was built, called the filter building which housed the laboratory and the water rate increased for the first time in 50 years. In 1950, levees around the Fleur Drive treatment plant were built. In 1959, DMWW started fluoridating its water at the request of the city council.
In 1955, the Nollen Standpipe and the Wilchinski Standpipe were built. Land for a north standpipe was purchased in 1955, but construction did not begin until 1959. In 1973, this standpipe, near Sears at Merle Hay Mall, was named Tenny standpipe.
In 1957, Iowa Light and Power installed a substation at DMWW and electric motors and pumps began to be used ending steam power. In 1958, eight more filters and two more softening basins were added to the filter plant and Congress authorized construction of a dam at Saylorville, Iowa on the Des Moines River for Saylorville Lake which allowed the Army Corps of Engineers of the Rock Island District to provide flood control for both the Des Moines River system, including downtown Des Moines, and also the Mississippi River system but groundbreaking took until July 1965 and becoming fully operational in 1977.
In 1972, DMWW installed water meter reading equipment on the outside of homes.
In 1985, an office building was built.
In 1992, the eight tanks of a nitrate removal facility were built.
During the Great Flood of 1993, the Raccoon River crested at a record 14.7 feet above flood stage, forcing the Fleur Drive treatment plant to be shut down and residents of the greater Des Moines metropolitan area were without any water service for 11 days, and non-potable water for 18 days. The height of the levees was increased to a height of 31 feet.
In 1998, ground was broken for a new treatment plant, called the Maffitt Treatment Plant.
21st century
In May 2000, a 25 mgd facility, the Water Treatment Plant at Maffitt Lake, renamed the L.D. McMullen Water Treatment Plant in 2007, began operation using five radial collector wells as its main source, and additionally also from Maffitt Reservoir.
In August 2003, a monthly pump record was set at 2,262.82 million gallons.
In June 2006, ground was broken for a third treatment plant with a capacity of 10 mgd, the Saylorville Water Treatment Plant, using membrane technology to soften and purify the water.
In June 2006, a daily pumpage record of 90.19 mg was set.
During the Iowa flood of 2008, the Raccoon River crested at 12.5 feet above flood stage, but DMWW operated normally due to levee work and flood preparation.
In April 2011, the Saylorville Water Treatment Plant began operating, serving customers north of Des Moines. First, oxidation precipitates dissolved iron and manganese in shallow groundwater. Ultrafiltration (UF) membranes filter out particulate i.e. undissolved material in the water. Thereafter, part of the water will go through the reverse osmosis membranes, which have smaller pores than the UF membranes and filter out dissolved material in the water, targeting calcium and magnesium ions (water hardness) and for nitrate reduction.
In July 2012, a new monthly pumpage record was set at 2,544.12 million gallons and a new record for daily pumpage at million gallons.
In March 2015, the DMWW board voted to sue Calhoun, Buena Vista and Sac county for high nitrate discharges into the Raccoon River, and their failure to obtain a National Pollution Discharge Elimination System permit or state permit in violation of the Clean Water Act. The lawsuit contends that tile drainage lines exacerbate pollution by moving nutrients more quickly to waterways. DMWW must comply with the maximum contaminant level (MCL) standard set by the Environmental Protection Agency, and pay to remove the nitrate and in the winter of 2014/2015 DMWW spent $540,000 for nitrate removal. DMWW wants agricultural polluters to abide by the Clean Water Act, which they are exempted from, because agricultural runoff comes from multiple point sources across a large region. The Iowa Farm Bureau and Governor Terry Branstad are against the lawsuit and the Iowa Drainage District Association wants to help the lawsuit. Most Iowans have supported the lawsuit, up to 71% of urban residents, but most did not think water quality was the state's most important issue. Even the Iowa Soybean Association has conceded, that more ways to finance the 2013 Iowa Nutrient Reduction Strategy plan (cutting the nitrogen and phosphorus by 45 percent) need to be found in light of the problem in the Gulf of Mexico dead zone. In March 2017, a federal district court dismissed the DMWW claims saying the Iowa legislature was "the appropriate body to address the state's water quality crisis".
In February 2017, a bill called Dismantling the Des Moines Water Works - HF 484/SF 456 was proposed to move assets and power to local municipalities. DMWW´s Bill Stowe called it "clearly retribution for our lawsuit". At the end of the legislative session in April 2017, the bill was moved to unfinished business in the House and was funneled in the Senate.
System Information
, the DMWW pumps water from three conditioning plants through about of buried water main with 9,800 valves. It maintains over 80,000 water meters and automated reading devices, about 10,000 fire hydrants and 7 water storage facilities. Maximum daily demand was 96.64 MGD in July 2012.
The water pressure averages 50 psi but ranges from 35 psi to more than 100 psi depending on the location. Water towers help stabilize pressure in some zones. Water is pumped inside when water demand is low and flows back out to satisfy higher demands. Des Moines is divided into four pressure zones, with dedicated pumping stations.
DMWW operates Water Works Park, an urban park of about 1,500 acres near downtown Des Moines, and Maffitt Reservoir with 1,300 acres of wooded land and a 200-acre lake.
DMWW sold water wholesale to more than 20 regional entities. West Des Moines and Waukee have been using 20 percent of DMWW clean water or 12.5 million gallons of water a day. West Des Moines Water Works, which produces 70% of the water West Des Moines consumes, found in 2015 that the projected water demand would meet its plant´s production limits in 2017. Both it and Waukee consider tapping the Raccoon River alluvial aquifer after DMWW increased its rate by 10% in 2016.
Budget
DMWW assets were $250 million.
The 2017 budget assumes $62 million of operating revenue and operating expenses of $41.6 million, capital infrastructure costs of $29.6 million and $5.3 million for debt repayment.
Water rate
Effective April 2017, residential customers inside Des Moines pay $4.11/1000 gallons of water, and residents within Polk County almost twice as much, $8.10. A separate water availability fee varies depending on the meter size from $6 to $75 inside the city. For sewer service inside the city, the rate is $6.59 per 1,000 gallons, outside the city it is $13.18 per 1,000 gallons. Stormwater services cost $11.50 per Equivalent Residential Unit. DMWW also bills on behalf of the Des Moines City Council for Solid Waste Services, its recycling program and yard waste.
Governance
Under Iowa Code Section 388, the utility is owned by the water rate payers and operated by a Board of trustees, who are appointed by the Mayor of the city of Des Moines and approved by the city council. The Board of trustees has all the powers of the city council to run the utility, but cannot levy taxes. The Board of Trustees hires a General Manager to operate the utility, who prepares an annual budget using revenue from the sale of water as its primary income. The Board of trustees reviews, modifies, and approves it. It is the only body which can enter into contracts.
See also
Lists of public utilities
List of United States water companies
References
External links
Government of Des Moines, Iowa
Water companies of the United States
Public utilities of the United States
1871 establishments in Iowa
Water and politics
Water treatment
Litigators | Des Moines Water Works | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 3,041 | [
"Water treatment",
"Environmental engineering",
"Water technology",
"Water pollution"
] |
53,374,506 | https://en.wikipedia.org/wiki/Sigma-bond%20metathesis | In organometallic chemistry, sigma-bond metathesis is a chemical reaction wherein a metal-ligand sigma bond undergoes metathesis (exchange of parts) with the sigma bond in some reagent. The reaction is illustrated by the exchange of lutetium(III) methyl complex with a hydrocarbon (R-H):
(C5Me5)2Lu-CH3 + R-H → (C5Me5)2Lu-R + CH4
This reactivity was first observed by Patricia Watson, a researcher at duPont.
The reaction is mainly observed for complexes of metals with d0 configuration, e.g. complexes of Sc(III), Zr(IV), Nb(V), Ta(V), etc. f-Element complexes also participate, regardless of the number of f-electrons. The reaction is thought to proceed via cycloaddition. Indeed, the rate of the reaction is characterized by a highly negative entropy of activation, indicating an ordered transition state. For metals unsuited for redox, sigma bond metathesis provides a pathway for introducing substituents.
The reaction attracted much attention because hydrocarbons are normally unreactive substrates, whereas some sigma-bond metatheses are facile. Unfortunately the reaction does not readily allow the introduction of functional groups. It has been suggested that dehydrocoupling reactions proceed via sigma-bond metathesis.
See also
Carbon–hydrogen bond activation
Metal-catalyzed σ-bond rearrangement
References
Organometallic chemistry | Sigma-bond metathesis | [
"Chemistry"
] | 318 | [
"Organometallic chemistry"
] |
53,375,072 | https://en.wikipedia.org/wiki/Social%20profiling | Social profiling is the process of constructing a social media user's profile using his or her social data. In general, profiling refers to the data science process of generating a person's profile with computerized algorithms and technology. There are various platforms for sharing this information with the proliferation of growing popular social networks, including but not limited to LinkedIn, Google+, Facebook and Twitter.
Social profile and social data
A person's social data refers to the personal data that they generate either online or offline (for more information, see social data revolution). A large amount of these data, including one's language, location and interest, is shared through social media and social network. Users join multiple social media platforms and their profiles across these platforms can be linked using different methods to obtain their interests, locations, content, and friend list. Altogether, this information can be used to construct a person's social profile.
Meeting the user's satisfaction level for information collection is becoming more challenging. This is because of too much "noise" generated, which affects the process of information collection due to explosively increasing online data. Social profiling is an emerging approach to overcome the challenges faced in meeting user's demands by introducing the concept of personalized search while keeping in consideration user profiles generated using social network data. A study reviews and classifies research inferring users social profile attributes from social media data as individual and group profiling. The existing techniques along with utilized data sources, the limitations, and challenges were highlighted.
The prominent approaches adopted include machine learning,
ontology, and fuzzy logic. Social media data from Twitter and Facebook have been used by most of the studies to infer the social attributes of users. The literature showed that user social attributes, including age, gender, home location, wellness, emotion, opinion, relation, influence are still need to be explored.
Personalized meta-search engines
The ever-increasing online content has resulted in the lack of proficiency of centralized search engine's results. It can no longer satisfy user's demand for information. A possible solution that would increase coverage of search results would be meta-search engines, an approach that collects information from numerous centralized search engines. A new problem thus emerges, that is too much data and too much noise is generated in the collection process.
Therefore, a new technique called personalized meta-search engines was developed. It makes use of a user's profile (largely social profile) to filter the search results. A user's profile can be a combination of a number of things, including but not limited to, "a user's manual selected interests, user's search history", and personal social network data.
Social media profiling
According to Samuel D. Warren II and Louis Brandeis (1890), disclosure of private information and the misuse of it can hurt people's feelings and cause considerable damage in people's lives. Social networks provide people access to intimate online interactions; therefore, information access control, information transactions, privacy issues, connections and relationships on social media have become important research fields and are subjects of concern to the public.
Ricard Fogues and other co-authors state that "any privacy mechanism has at its base an access control", that dictate "how permissions are given, what elements can be private, how access rules are defined, and so on". Current access control for social media accounts tend to still be very simplistic: there is very limited diversity in the category of relationships on for social network accounts. User's relationships to others are, on most platforms, only categorized as "friend" or "non-friend" and people may leak important information to "friends" inside their social circle but not necessarily users to they consciously want to share the information to. The below section is concerned with social media profiling and what profiling information on social media accounts can achieve.
Privacy leaks
A lot of information is voluntarily shared on online social networks, such as photos and updates on life activities (new job, hobbies, etc.). People rest assured that different social network accounts on different platforms will not be linked as long as they do not grant permission to these links. However, according to Diane Gan, information gathered online enables "target subjects to be identified on other social networking sites such as Foursquare, Instagram, LinkedIn, Facebook and Google+, where more personal information was leaked".
The majority of social networking platforms use the "opt out approach" for their features. If users wish to protect their privacy, it is user's own responsibility to check and change the privacy settings as a number of them are set to default option. A major social network platforms have developed geo-tag functions and are in popular usage. This is concerning because 39% of users have experienced profiling hacking; 78% burglars have used major social media networks and Google Street-view to select their victims; and an astonishing 54% of burglars attempted to break into empty houses when people posted their status updates and geo-locations.
Facebook
Formation and maintenance of social media accounts and their relationships with other accounts are associated with various social outcomes. In 2015, for many firms, customer relationship management is essential and is partially done through Facebook. Before the emergence and prevalence of social media, customer identification was primarily based upon information that a firm could directly acquire: for example, it may be through a customer's purchasing process or voluntary act of completing a survey/loyalty program. However, the rise of social media has greatly reduced the approach of building a customer's profile/model based on available data. Marketers now increasingly seek customer information through Facebook; this may include a variety of information users disclose to all users or partial users on Facebook: name, gender, date of birth, e-mail address, sexual orientation, marital status, interests, hobbies, favorite sports team(s), favorite athlete(s), or favorite music, and more importantly, Facebook connections.
However, due to the privacy policy design, acquiring true information on Facebook is no trivial task. Often, Facebook users either refuse to disclose true information (sometimes using pseudonyms) or setting information to be only visible to friends, Facebook users who "LIKE" your page are also hard to identify. To do online profiling of users and cluster users, marketers and companies can and will access the following kinds of data: gender, the IP address and city of each user through the Facebook Insight page, who "LIKED" a certain user, a page list of all the pages that a person "LIKED" (transaction data), other people that a user follow (even if it exceeds the first 500, which we usually can not see) and all the publicly shared data.
Twitter
First launched on the Internet in March 2006, Twitter is a platform on which users can connect and communicate with any other user in just 280 characters. Like Facebook, Twitter is also a crucial tunnel for users to leak important information, often unconsciously, but able to be accessed and collected by others.
According to Rachel Nuwer, in a sample of 10.8 million tweets by more than 5,000 users, their posted and publicly shared information are enough to reveal a user's income range. A postdoctoral researcher from the University of Pennsylvania, Daniel Preoţiuc-Pietro and his colleagues were able to categorize 90% of users into corresponding income groups. Their existing collected data, after being fed into a machine-learning model, generated reliable predictions on the characteristics of each income group.
The mobile app called Streamd.in displays live tweets on Google Maps by using geo-location details attached to the tweet, and traces the user's movement in the real world.
Profiling photos on social network
The advent and universality of social media networks have boosted the role of images and visual information dissemination. Many types of visual information on social media transmit messages from the author, location information and other personal information. For example, a user may post a photo of themselves in which landmarks are visible, which can enable other users to determine where they are. In a study done by Cristina Segalin, Dong Seon Cheng and Marco Cristani, they found that profiling user posts' photos can reveal personal traits such as personality and mood. In the study, convolutional neural networks (CNNs) is introduced. It builds on the main characteristics of computational aesthetics CA (emphasizing "computational methods", "human aesthetic point of view", and "the need to focus on objective approaches") defined by Hoenig (Hoenig, 2005). This tool can extract and identify content in photos.
Tags
In a study called "A Rule-Based Flickr Tag Recommendation System", the author suggests personalized tag recommendations, largely based on user profiles and other web resources. It has proven to be useful in many aspects: "web content indexing", "multimedia data retrieval", and enterprise Web searches.
Delicious
Flickr
Zooomr
Marketing
In 2011, marketers and retailers are increasing their market presence by creating their own pages on social media, on which they post information, ask people to like and share to enter into contests, and much more. Studies in 2011 show that on average a person spends about 23 minutes on a social networking site per day. Therefore, companies from small to large ones are investing in gathering user behavior information, rating, reviews, and more.
Facebook
Until 2006, communications online are not content led in terms of the amount of time people spend online. However, content sharing and creating has been the primary online activity of general social media users and that has forever changed online marketing. In the book Advanced Social media Marketing, the author gives an example of how a New York wedding planner might identify his audience when marketing on Facebook. Some of these categories may include: (1) who live in the United States; (2) Who live within 50 miles of New York; (3) Age 21 and older; (4) engaged female. No matter you choose to pay cost per click or cost per impressions/views "the cost of Facebook Marketplace ads and Sponsored Stories is set by your maximum bid and the competition for the same audiences". The cost of clicks is usually $0.5–1.5 each.
Tools
Klout
Klout is a popular online tool that focuses on assessing a user's social influence by social profiling. It takes several social media platforms (such as Facebook, Twitter etc.) and numerous aspects into account and generate a user's score from 1 to 100. Regardless of one's number of likes for a post, or connections on LinkedIn, social media contains plentiful personal information. Klout generates a single score that indicates a person's influence.
In a study called "How Much Klout do You Have...A Test of System Generated Cues on Source Credibility" done by Chad Edwards, Klout scores can influence people's perceived credibility. As Klout Score becomes a popular combined-into-one-score method of accessing people's influence, it can be a convenient tool and a biased one at the same time. A study of how social media followers influence people's judgments done by David Westerman illustrates that possible bias that Klout may contain. In one study, participants were asked to view six identical mock Twitter pages with only one major independent variable: page followers. Result shows that pages with too many or too fewer followers would both decrease its credibility, despite its similar content. Klout score may be subject to the same bias as well.
While this is sometimes used during recruitment process, it remains to be controversial.
Kred
Kred not only assigns each user an influence score, but also allows each user to claim a Kred profile and Kred account. Through this platform, each user can view how top influencers engage with their online community and how each of your online action impacted your influence scores.
Several suggestions that Kred is giving to the audience about increasing influence are: (1) be generous with your audience, free comfortable sharing content from your friends and tweeting others; (2) join an online community; (3) create and share meaningful content; (4) track your progress online.
Follower Wonk
Follower Wonk is specifically targeted towards Twitter analytics, which helps users to understand follower demographics, and optimizes your activities to find which activity attracts the most positive feedback from followers.
Keyhole
Keyhole is a hashtag tracking and analytics device that tracks Instagram, Twitter and Facebook hashtag data. It is a service that allows you to track which top influencer is using a certain hashtag and what are the other demographic information about the hashtag. When you enter a hashtag on its website, it will automatically randomly sample users that currently used this tag which allows user to analyze each hashtag they are interested in.
Online activist social profile
The prevalence of the Internet and social media has provided online activists both a new platform for activism, and the most popular tool. While online activism might stir up great controversy and trend, few people actually participate or sacrifice for relevant events. It becomes an interesting topic to analyse the profile of online activists. In a study done by Harp and his co-authors about online activist in China, Latin America and United States, the majority of online activists are males in Latin America and China with a median income of $10,000 or less, while the majority of online activist is female in United States with a median income of $30,000 - $69,999; and the education level of online activists in the United States tend to be postgraduate work/education while activists in other countries have lower education levels.
A closer examination of their online shared content shows that the most shared information online include five types:
To fundraise: Out of the three countries, China's activists have the most content on fundraise out of the three.
To post links: Latin American activists have does the most on posting links.
To promote debate or Discussion: Both Latin America's and China's activists posts more contents to promote debate or discussion than American activists do.
To post information such as announcements and news: American activists post more such content than the activists from other countries.
To communicate with Journalist: In this section, China's activists gets the lead.
Social credit score in China
The Chinese government hopes to establish a "social-credit system" that aims to score "financial creditworthiness of citizens", social behavior and even political behaviour. This system will be combining big data and social profiling technologies. According to Celia Hatton from BBC News, everyone in China will be expected to enroll in a national database that includes and automatically calculates fiscal information, political behavior, social behavior and daily life including minor traffic violations – a single score that evaluates a citizen's trustworthiness.
Credibility scores, social influence scores and other comprehensive evaluations of people are not rare in other countries. However, China's "social-credit system" remains to be controversial as this single score can be a reflection of a person's every aspect. Indeed, "much about the social-credit system remains unclear".
How would companies be limited by credit score system in China?
Although the implementation of social credit score remains controversial in China, Chinese government aims to fully implement this system by 2018. According to Jake Laband (the deputy director of the Beijing office of the US-China Business Council), low credit scores will "limit eligibility for financing, employment, and Party membership, as well restrict real estate transactions and travel." Social credit score will not only be affected by legal criteria, but also social criteria, such as contract breaking. However, this has been a great concern for privacy for big companies due to the huge amount of data that will be analyzed by the system.
See also
Account verification
Digital identity
Online identity
Online identity management
Online presence management
Online reputation
Persona (user experience)
Personal information
Personal identity
Real-name system
Reputation management
Reputation system
Social media optimization
User profile
References
Data mining
Identity management
Social information processing
Social media
Social networks | Social profiling | [
"Technology"
] | 3,280 | [
"Computing and society",
"Social media"
] |
53,375,344 | https://en.wikipedia.org/wiki/Plant%20arithmetic | Plant arithmetic is a form of plant intelligence whereby plants appear to perform arithmetic operations – a form of number sense in plants. Some such plants include the Venus flytrap and Arabidopsis thaliana.
Arithmetic by species
Venus flytrap
The Venus flytrap can count to two and five in order to trap and then digest its prey.
The Venus flytrap is a carnivorous plant that catches its prey with a trapping structure formed by the terminal portion of each of the plant's leaves, which is triggered by tiny hairs on their inner surfaces. A Venus flytrap's reactions can occur due to electric and mechanical, or movement-related, changes. When an insect or spider crawling along the leaves contacts a hair, the trap prepares to close, snapping shut only if a second contact occurs within approximately twenty seconds of the first strike. The requirement of redundant triggering in this mechanism serves as a safeguard against wasting energy by trapping objects with no nutritional value, and the plant will only begin digestion after five more stimuli to ensure it has caught a live bug worthy of consumption.
There are two steps, which are a closed and locked state, that a Venus flytrap undergoes after its open state and before digestion, which differ due to the formation of the trap. A closed trap occurs when the two lobes close or catch prey. A locked trap occurs when the cilia further trap the prey. The trap can possess a strength of four newtons. In addition, the cilia can further hinder a creature's ability to escape.
The mechanism is so highly specialized that it can distinguish between living prey and non-prey stimuli, such as falling raindrops; two trigger hairs must be touched in succession within 20 seconds of each other or one hair touched twice in rapid succession, whereupon the lobes of the trap will snap shut, typically in about one-tenth of a second.
The number of days that the trap remains closed will depend on whether or not the plant has caught prey. Furthermore, the size of the prey can affect the number of days needed for digestion. If a creature is too small, then the Venus flytrap has the ability to release it, which means that it can start the stage of becoming semi-open. The transition from closed to open will take two days and can result after the plant has finished digesting or realizing it has not caught anything worthwhile. One day will be needed to become semi-open, which creates a concave look, and the other day will allow the Venus flytrap to become fully open, which creates a convex look. The angle of a Venus flytrap's lobes when they are open can be impacted by the water within it.
Arabidopsis thaliana
Arabidopsis thaliana in effect performs division to control starch use at night.
Most plants accumulate starch by day, then metabolize it at a fixed rate during night time. However, if the onset of darkness is unusually early, Arabidopsis thaliana reduces its use of starch by an amount that effectively requires division. However, there are alternative explanations, such as feedback control by sensing the amount of soluble sugars left. As of 2015, open questions remain.
See also
References
Arithmetic
Arithmetic
Cognitive science
Ethology | Plant arithmetic | [
"Mathematics",
"Biology"
] | 665 | [
"Behavior",
"Plants",
"Plant intelligence",
"Behavioural sciences",
"Arithmetic",
"Ethology",
"Number theory"
] |
53,375,446 | https://en.wikipedia.org/wiki/Steffen%27s%20polyhedron | In geometry, Steffen's polyhedron is a flexible polyhedron discovered (in 1978) by and named after . It is based on the Bricard octahedron, but unlike the Bricard octahedron its surface does not cross itself. It has nine vertices, 21 edges, and 14 triangular faces. Its faces can be decomposed into three subsets: two six-triangle-patches from a Bricard octahedron, and two more triangles (the central two triangles of the net shown in the illustration) that link these patches together.
It obeys the strong bellows conjecture, meaning that (like the Bricard octahedron on which it is based) its Dehn invariant stays constant as it flexes.
Although it has been claimed to be the simplest possible flexible polyhedron without self-crossings, a 2024 preprint by Gallet et al. claims to construct a simpler non-self-crossing flexible polyhedron with only eight vertices.
References
External links
Steffen's Polyhedron, Greg Egan
Nonconvex polyhedra
Mathematics of rigidity | Steffen's polyhedron | [
"Physics"
] | 229 | [
"Mathematics of rigidity",
"Mechanics"
] |
53,375,615 | https://en.wikipedia.org/wiki/Dynamic%20Roentgen%20stereophotogrammetry | Dynamic Roentgen stereophotogrammetry (also referred to as dynamic RSA) is a modern and sophisticated x-ray recording method, used to measure real-time 3D motions of prostheses and bones during motion with high accuracy. It is mostly used in orthopedic research settings and is an advancement of conventional RSA.
Conventional static RSA is used to evaluate migration of prosthesis with respect to the bone in three dimensions as a function of time. Migration of the prosthesis are normal 12‐24 months after the surgery. Ongoing migration increase the risk of aseptic loosening with revision surgery as a consequence. The method has proven valuable in the evaluation of fixation for hip and knee arthroplasty, as early RSA evaluations have shown high predictive value for later aseptic component loosening.
In contrast, Dynamic RSA makes it possible to accurately assess both micro movements in the fixation interface and kinematics of the prosthetic components in three dimensions, during active motions.
References
Prosthetics
X-rays | Dynamic Roentgen stereophotogrammetry | [
"Physics",
"Engineering",
"Biology"
] | 221 | [
"Biological engineering",
"Bioengineering stubs",
"X-rays",
"Spectrum (physical sciences)",
"Biotechnology stubs",
"Electromagnetic spectrum",
"Medical technology stubs",
"Medical technology"
] |
53,376,581 | https://en.wikipedia.org/wiki/Abu%27l-%27Anbas%20Saymari | Abu'l-'Anbas Saymari Mohammad bin Eshaq bin Abi'l-'Anbas bin Al-Maghira bin Mahan (; ) was an Iranian astrologer, astronomer, poet and author. He was born in 213/828 in Kufa, and died in 275/889. He seems to have spent much of his time at the caliphal court from Motawakkel's reign (847861) to Moʿtamed's (870892). His great-great-grandfather's name, and his knowledge of the Sasanian astrologers Zaradūšt and Bozorjmehr, indicates that he was of Iranian origin.
List of known works
(Book of the Refutation of Astrologers), lost;
(Book of Judgements of the Stars), lost;
(Book of the Introduction to the Art of Astrology), perhaps identical with no. 5;
(Book of Nativities), lost;
(Book of the Introduction to the Science of the Stars);
(Book on Stellar Computation);
.
References
Sources
Further reading
Medieval Iranian astrologers
9th-century Iranian astronomers
Astronomers of the medieval Islamic world | Abu'l-'Anbas Saymari | [
"Astronomy"
] | 254 | [
"Astronomers",
"Astronomer stubs",
"Astronomy stubs"
] |
53,376,859 | https://en.wikipedia.org/wiki/Health%20and%20safety%20hazards%20of%20nanomaterials | The health and safety hazards of nanomaterials include the potential toxicity of various types of nanomaterials, as well as fire and dust explosion hazards. Because nanotechnology is a recent development, the health and safety effects of exposures to nanomaterials, and what levels of exposure may be acceptable, are subjects of ongoing research. Of the possible hazards, inhalation exposure appears to present the most concern, with animal studies showing pulmonary effects such as inflammation, fibrosis, and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure, and dust explosion hazards, are also a concern.
Guidance has been developed for hazard controls that are effective in reducing exposures to safe levels, including substitution with safer forms of a nanomaterial, engineering controls such as proper ventilation, and personal protective equipment as a last resort. For some materials, occupational exposure limits have been developed to determine a maximum safe airborne concentration of nanomaterials, and exposure assessment is possible using standard industrial hygiene sampling methods. An ongoing occupational health surveillance program can also help to protect workers. Microplastics and nanoparticles from plastic containers are an increasing concern.
Background
Nanotechnology is the manipulation of matter at the atomic scale to create materials, devices, or systems with new properties or functions, with potential applications in energy, healthcare, industry, communications, agriculture, consumer products, and other sectors. Nanomaterials have at least one primary dimension of less than 100 nanometers, and often have properties different from those of their bulk components that are technologically useful. The classes of materials of which nanoparticles are typically composed include elemental carbon, metals or metal oxides, and ceramics. According to the Woodrow Wilson Center, the number of consumer products or product lines that incorporate nanomaterials increased from 212 to 1317 from 2006 to 2011. Worldwide investment in nanotechnology increased from $432 million in 1997 to about $4.1 billion in 2005.
Because nanotechnology is a recent development, the health and safety effects of exposures to nanomaterials, and what levels of exposure may be acceptable, is not yet fully understood. Research concerning the handling of nanomaterials is underway, and guidance for some nanomaterials has been developed. As with any new technology, the earliest exposures are expected to occur among workers conducting research in laboratories and pilot plants, making it important that they work in a manner that is protective of their safety and health.
A risk management system is composed of three parts. Hazard identification involves determining what health and safety concerns are present for both the nanomaterial and its corresponding bulk material, based on a review of safety data sheets, peer-reviewed literature, and guidance documents on the material. For nanomaterials, toxicity hazards are the most important, but dust explosion hazards may also be relevant. Exposure assessment involves determining actual routes of exposure in a specific workplace, including a review of which areas and tasks are most likely to cause exposure. Exposure control involves putting procedures in places to minimize or eliminate exposures according to the hierarchy of hazard controls. Ongoing verification of hazard controls can occur through monitoring of airborne nanomaterial concentrations using standard industrial hygiene sampling methods, and an occupational health surveillance program may be instituted.
A recently adopted risk management method is the Safe by design (SbD) approach. It aims to eliminate or reduce risks of new technologies including nanotechnology, at the design stage of a product or production process. Anticipation of risks is challenging because some risks could emerge only after a technology is implemented (at later stages in the innovation process). In the later cases, the application of other risk management strategies based on non-design principles need to be applied. It considers the purposes and constrains for implementation of SbD approaches in the industrial innovation process and on the basis of those, establish optimal workflows to identify risks and propose solutions to reduce or mitigate them as early as possible in the innovation process called Safe by Design strategies.
Hazards
Toxicity
Respiratory
Inhalation exposure is the most common route of exposure to airborne particles in the workplace. The deposition of nanoparticles in the respiratory tract is determined by the shape and size of particles or their agglomerates, and they are deposited in the alveolar compartment to a greater extent than larger respirable particles. Based on animal studies, nanoparticles may enter the bloodstream from the lungs and translocate to other organs, including the brain. The inhalation risk is affected by the dustiness of the material, the tendency of particles to become airborne in response to a stimulus. Dust generation is affected by the particle shape, size, bulk density, and inherent electrostatic forces, and whether the nanomaterial is a dry powder or incorporated into a slurry or liquid suspension.
Animal studies indicate that carbon nanotubes and carbon nanofibers can cause pulmonary effects including inflammation, granulomas, and pulmonary fibrosis, which were of similar or greater potency when compared with other known fibrogenic materials such as silica, asbestos, and ultrafine carbon black. Some studies in cells or animals have shown genotoxic or carcinogenic effects, or systemic cardiovascular effects from pulmonary exposure. Although the extent to which animal data may predict clinically significant lung effects in workers is not known, the toxicity seen in the short-term animal studies indicate a need for protective action for workers exposed to these nanomaterials. As of 2013, further research was needed in long-term animal studies and epidemiologic studies in workers. No reports of actual adverse health effects in workers using or producing these nanomaterials were known as of 2013. Titanium dioxide (TiO2) dust is considered a lung tumor risk, with ultrafine (nanoscale) particles having an increased mass-based potency relative to fine TiO2, through a secondary genotoxicity mechanism that is not specific to TiO2 but primarily related to particle size and surface area.
Dermal
Some studies suggest that nanomaterials could potentially enter the body through intact skin during occupational exposure. Studies have shown that particles smaller than 1 μm in diameter may penetrate into mechanically flexed skin samples, and that nanoparticles with varying physicochemical properties were able to penetrate the intact skin of pigs. Factors such as size, shape, water solubility, and surface coating directly affect a nanoparticle's potential to penetrate the skin. At this time, it is not fully known whether skin penetration of nanoparticles would result in adverse effects in animal models, although topical application of raw SWCNT to nude mice has been shown to cause dermal irritation, and in vitro studies using primary or cultured human skin cells have shown that carbon nanotubes can enter cells and cause release of pro-inflammatory cytokines, oxidative stress, and decreased viability. It remains unclear, however, how these findings may be extrapolated to a potential occupational risk. In addition, nanoparticles may enter the body through wounds, with particles migrating into the blood and lymph nodes.
Gastrointestinal
Ingestion can occur from unintentional hand-to-mouth transfer of materials; this has been found to happen with traditional materials, and it is scientifically reasonable to assume that it also could happen during handling of nanomaterials. Ingestion may also accompany inhalation exposure because particles that are cleared from the respiratory tract via the mucociliary escalator may be swallowed.
Fire and explosion
There is concern that engineered carbon nanoparticles, when manufactured on an industrial scale, could pose a dust explosion hazard, especially for processes such as mixing, grinding, drilling, sanding, and cleaning. Knowledge remains limited about the potential explosivity of materials when subdivided down to the nanoscale. The explosion characteristics of nanoparticles are highly dependent on the manufacturer and the humidity.
For microscale particles, as particle size decreases and the specific surface area increases, the explosion severity increases. However, for dusts of organic materials such as coal, flour, methylcellulose, and polyethylene, severity ceases to increase as the particle size is reduced below ~50 μm. This is because decreasing particle size primarily increases the volatilization rate, which becomes rapid enough that that gas phase combustion becomes the rate limiting step, and further decrease in particle size will not increase the overall combustion rate. While the minimum explosion concentration does not vary significantly with nanoparticle size, the minimum ignition energy and temperature have been found to decrease with particle size.
Metal-based nanoparticles exhibit more severe explosions than do carbon nanomaterials, and their chemical reaction pathway is qualitatively different. Studies on aluminum nanoparticles and titanium nanoparticles indicate that they are explosion hazards. One study found that the likelihood of an explosion but not its severity increases significantly for nanoscale metal particles, and they can spontaneously ignite under certain conditions during laboratory testing and handling.
High-resistivity powders can accumulate electric charge causing a spark hazard, and low-resistivity powders can build up in electronics causing a short circuit hazard, both of which can provide an ignition source. In general, powders of nanomaterials have higher resistivity than the equivalent micron-scale powders, and humidity decreases their resistivity. One study found powders of metal-based nanoparticles to be mid- to high-resistivity depending on humidity, while carbon-based nanoparticles were found to be low-resistivity regardless of humidity. Powders of nanomaterials are unlikely to present an unusual fire hazard as compared to their cardboard or plastic packaging, as they are usually produced in small quantities, with the exception of carbon black. However, the catalytic properties of nanoparticles and nanostructured porous materials may cause untended catalytic reactions that, based on their chemical composition, would not otherwise be anticipated.
Radioactivity
Engineered radioactive nanoparticles have applications in medical diagnostics, medical imaging, toxicokinetics, and environmental health, and are being investigated for applications in nuclear medicine. Radioactive nanoparticles present special challenges in operational health physics and internal dosimetry that are not present for vapors or larger particles, as the nanoparticles' toxicokinetics depend on their physical and chemical properties including size, shape, and surface chemistry. In some cases, the inherent physicochemical toxicity of the nanoparticle itself may lead to lower exposure limits than those associated with the radioactivity alone, which is not the case with most radioactive materials. In general, however, most elements of a standard radiation protection program are applicable to radioactive nanomaterials, and many hazard controls for nanomaterials will be effective with the radioactive versions.
Hazard controls
Controlling exposures to hazards is the fundamental method of protecting workers. The hierarchy of hazard control is a framework that encompasses a succession of control methods to reduce the risk of illness or injury. In decreasing order of effectiveness, these are elimination of the hazard, substitution with another material or process that is a lesser hazard, engineering controls that isolate workers from the hazard, administrative controls that change workers' behavior to limit the quantity or duration of exposure, and personal protective equipment worn on the workers' body.
Prevention through design is the concept of applying control methods to minimize hazards early in the design process, with an emphasis on optimizing employee health and safety throughout the life cycle of materials and processes. It increases the cost-effectiveness of occupational safety and health because hazard control methods are integrated early into the process, rather than needing to disrupt existing procedures to include them later. In this context, adopting hazard controls earlier in the design process and higher on the hierarchy of controls leads to faster time to market, improved operational efficiency, and higher product quality.
Elimination and substitution
Elimination and substitution are the most desirable approaches to hazard control, and are most effective early in the design process. Nanomaterials themselves often cannot be eliminated or substituted with conventional materials because their unique properties are necessary to the desired product or process. However, it may be possible to choose properties of the nanoparticle such as size, shape, functionalization, surface charge, solubility, agglomeration, and aggregation state to improve their toxicological properties while retaining the desired functionality. Other materials used incidentally in the process, such as solvents, are also amenable to substitution.
In addition to the materials themselves, procedures used to handle them can be improved. For example, using a nanomaterial slurry or suspension in a liquid solvent instead of a dry powder will reduce dust exposure. Reducing or eliminating steps that involve transfer of powder or opening packages containing nanomaterials also reduces aerosolization and thus the potential hazard to the worker. Reducing agitation procedures such as sonication, and reducing the temperature of reactors to minimize release of nanomaterials in exhaust, also reduce hazards to workers.
Engineering controls
Engineering controls are physical changes to the workplace that isolate workers from hazards by containing them in an enclosure, or removing contaminated air from the workplace through ventilation and filtering. They are used when hazardous substances and processes cannot be eliminated or replaced with less hazardous substitutes. Well-designed engineering controls are typically passive, in the sense of being independent of worker interactions, which reduces the potential for worker behavior to impact exposure levels. The initial cost of engineering controls can be higher than administrative controls or personal protective equipment, but the long-term operating costs are frequently lower and can sometimes provide cost savings in other areas of the process. The type of engineering control optimal for each situation is influenced by the quantity and dustiness of the material as well as the duration of the task.
Ventilation systems can be local or general. General exhaust ventilation operates on an entire room through a building's HVAC system. It is inefficient and costly as compared to local exhaust ventilation, and is not suitable by itself for controlling exposure, although it can provide negative room pressure to prevent contaminants from exiting the room. Local exhaust ventilation operates at or near the source of contamination, often in conjunction with an enclosure. Examples of local exhaust systems include fume hoods, gloveboxes, biosafety cabinets, and vented balance enclosures. Exhaust hoods lacking an enclosure are less preferable, and laminar flow hoods are not recommended because they direct air outwards towards the worker. Several control verification techniques can be used with ventilation systems, including pitot tubes, hot-wire anemometers, smoke generators, tracer-gas leak testing, and standardized testing and certification procedures.
Examples of non-ventilation engineering controls include placing equipment that may release nanomaterials in a separate room, and placing walk-off sticky mats at room exits. Antistatic devices can be used when handling nanomaterials to reduce their electrostatic charge, making them less likely to disperse or adhere to clothing. Standard dust control methods such as enclosures for conveyor systems, using a sealed system for bag filling, and water spray application are effective at reducing respirable dust concentrations.
Administrative controls
Administrative controls are changes to workers' behavior to mitigate a hazard. They include training on best practices for safe handling, storage, and disposal of nanomaterials, proper awareness of hazards through labeling and warning signage, and encouraging a general safety culture. Administrative controls can complement engineering controls should they fail, or when they are not feasible or do not reduce exposures to an acceptable level. Some examples of good work practices include cleaning work spaces with wet-wiping methods or a HEPA-filtered vacuum cleaner instead of dry sweeping with a broom, avoiding handling nanomaterials in a free particle state, storing nanomaterials in containers with tightly closed lids. Normal safety procedures such as hand washing, not storing or consuming food in the laboratory, and proper disposal of hazardous waste are also administrative controls. Other examples are limiting the time workers are handling a material or in a hazardous area, and exposure monitoring for the presence of nanomaterials.
Personal protective equipment
Personal protective equipment (PPE) must be worn on the worker's body and is the least desirable option for controlling hazards. It is used when other controls are not effective, have not been evaluated, or while doing maintenance or in emergency situations such as spill response. PPE normally used for typical chemicals are also appropriate for nanomaterials, including wearing long pants, long-sleeve shirts, and closed-toed shoes, and the use of safety gloves, goggles, and impervious laboratory coats. Nitrile gloves are preferred because latex gloves do not provide protection from most chemical solvents and may present an allergy hazard. Face shields are not an acceptable replacement for goggles because they do not protect against unbound dry materials. Woven cotton lab coats are not recommended for nanomaterials, as they can become contaminated with nanomaterials and release them later. Donning and removing PPE in a changing room prevents contamination of outside areas.
Respirators are another form of PPE. Respirator filters with a NIOSH air filtration rating of N95 or P100 have been shown to be effective at capturing nanoparticles, although leakage between the respirator seal and the skin may be more significant, especially with half-mask respirators. Surgical masks are not effective against nanomaterials. Smaller nanoparticles of size 4–20 nm are captured more efficiently by filters than larger ones of size 30–100 nm, because Brownian motion results in the smaller particles being more likely to contact a filter fiber. In the United States, the Occupational Safety and Health Administration requires fit testing and medical clearance for use of respirators, and the Environmental Protection Agency requires the use of full face respirators with N100 filters for multi-walled carbon nanotubes not embedded in a solid matrix, if exposure is not otherwise controlled.
Industrial hygiene
Occupational exposure limits
An occupational exposure limit (OEL) is an upper limit on the acceptable concentration of a hazardous substance in workplace air. As of 2016, quantitative OELs have not been determined for most nanomaterials. Agencies and organizations from several countries, including the British Standards Institute and the Institute for Occupational Safety and Health in Germany, have established OELs for some nanomaterials, and some companies have supplied OELs for their products. As of 2021, the U.S. National Institute for Occupational Safety and Health has determined non-regulatory recommended exposure limits (RELs) for three classes of nanomaterials:
1.0 μg/m3 for carbon nanotubes and carbon nanofibers as background-corrected elemental carbon as an 8-hour time-weighted average (TWA) respirable mass concentration
300 μg/m3 for ultrafine titanium dioxide as TWA concentrations for up to 10 hr/day during a 40-hour work week
0.9 μg/m3 for silver nanoparticles as an airborne respirable 8-hour TWA concentration
A properly tested, half-face particulate respirator will provide protection at exposure concentrations 10 times the REL, while an elastomeric full facepiece respirator with P100 filters will provide protection at 50 times the REL. In the absence of OELs, a control banding scheme may be used. Control banding is a qualitative strategy that uses a rubric to place hazards into one of four categories, or "bands", and each of which has a recommended level of hazard controls. Organizations including GoodNanoGuide, Lawrence Livermore National Laboratory, and Safe Work Australia have developed control banding tools that are specific for nanomaterials. The GoodNanoGuide control banding scheme is based only on exposure duration, whether the material is bound, and the extent of knowledge of the hazards. The LANL scheme assigns points for 15 different hazard parameters and 5 exposure potential factors. Alternatively, the "As Low As Reasonably Achievable" concept may be used.
Exposure assessment
Exposure assessment is a set of methods used to monitor contaminant release and exposures to workers. These methods include personal sampling, where samplers are located in the personal breathing zone of the worker, often attached to a shirt collar to be as close to the nose and mouth as possible; and area/background sampling, where they are placed at static locations. Assessment generally use both particle counters, which monitor the real-time quantity of nanomaterials and other background particles; and filter-based samples, which can be used to identify the nanomaterial, usually using electron microscopy and elemental analysis.
Not all instruments used to detect aerosols are suitable for monitoring occupational nanomaterial emissions because they may not be able to detect smaller particles, or may be too large or difficult to ship to a workplace. Suitable particle counters can detect a wide range of particle sizes, as nanomaterials may aggregate in the air. It is recommended to simultaneously test adjacent work areas to establish a background concentration, as direct reading instruments cannot distinguish the target nanomaterial from incidental background nanoparticles from motor or pump exhaust or heating vessels.
While mass-based metrics are traditionally used to characterize toxicological effects of exposure to air contaminants, as of 2013 it was unclear which metrics are most important with regard to engineered nanomaterials. Animal and cell-culture studies have shown that size and shape are the two major factors in their toxicological effects. Surface area and surface chemistry also appeared to be more important than mass concentration.
The NIOSH Nanomaterial Exposure Assessment Technique (NEAT 2.0) is a sampling strategy to determine exposure potential for engineered nanomaterials. It includes filter-based and area samples, as well as a comprehensive assessment of emissions at processes and job tasks to better understand peak emission periods. Evaluation of worker practices, ventilation efficacy, and other engineering exposure control systems and risk management strategies serve to allow for a comprehensive exposure assessment. The NIOSH Manual of Analytical Methods includes guidance on electron microscopy of filter samples of carbon nanotubes and nanofibers, and additionally some NIOSH methods developed for other chemicals can be used for off-line analysis of nanomaterials, including their morphology and geometry, elemental carbon content (relevant for carbon-based nanomaterials), and elemental makeup. Efforts to create reference materials are ongoing.
Occupational health surveillance
Occupational health surveillance involves the ongoing systematic collection, analysis, and dissemination of exposure and health data on groups of workers, for the purpose of preventing disease and evaluating the effectiveness of intervention programs. It encompasses both medical surveillance and hazard surveillance. A basic medical surveillance program contains a baseline medical evaluation and periodic follow-up examinations, post-incident evaluations, worker training, and identification of trends or patterns from medical screening data.
The related topic of medical screening focuses on the early detection of adverse health effects for individual workers, to provide an opportunity for intervention before disease processes occur. Screening may involve obtaining and reviewing an occupational history, medical examination, and medical testing. As of 2016, there were no specific screening tests or health evaluations to identify health effects in people that are caused solely by exposure to engineered nanomaterials. However, any medical screening recommendations for the bulk material that a nanoparticle is made of still apply, and in 2013 NIOSH concluded that the toxicologic evidence on carbon nanotubes and carbon nanofibers had advanced enough to make specific recommendations for the medical surveillance and screening of exposed workers. Medical screening and resulting interventions represent secondary prevention and do not replace primary prevention efforts based on direct hazard controls to minimize employee exposures to nanomaterials.
Emergency preparedness
It is recommended that a nanomaterial spill kit be assembled prior to an emergency and include barricade tape, nitrile or other chemically impervious gloves, an elastomeric full-facepiece respirator with P100 or N100 filters (fitted appropriately to the responder), adsorbent materials such as spill mats, disposable wipes, sealable plastic bags, walk-off sticky mats, a spray bottle with deionized water or another appropriate liquid to wet dry powders, and a HEPA-filtered vacuum. It is considered unsafe to use compressed air, dry sweeping, and vacuums without a HEPA filter to clear dust.
Regulation
United States
The Food and Drug Administration regulates nanomaterials under the Federal Food, Drug, and Cosmetic Act when used as food additives, drugs, or cosmetics. The Consumer Product Safety Commission requires testing and certification of many consumer products for compliance with consumer product safety requirements, and cautionary labeling of hazardous substances under the Federal Hazardous Substances Act.
The General Duty Clause of the Occupational Safety and Health Act requires all employers to keep their workplace free of serious recognized hazards. The Occupational Safety and Health Administration also has recording and reporting requirements for occupational injuries and illness under for businesses with more than 10 employees, and protection and communication regulations under . Companies producing new products containing nanomaterials must use the Hazard Communication Standard to create safety data sheets containing 16 sections for downstream users such as customers, workers, disposal services, and others. This may require toxicological or other testing, and all data or information provided must be vetted by properly controlled testing The ISO/TR 13329 standard provides guidance specifically on the preparation of safety data sheets for nanomaterials. The National Institute for Occupational Safety and Health does not issue regulations, but conducts research and makes recommendations to prevent worker injury and illness. State and local governments may have additional regulations.
The Environmental Protection Agency (EPA) regulates nanomaterials under the Toxic Substances Control Act, and has permitted limited manufacture of new chemical nanomaterials through the use of consent orders or Significant New Use Rules (SNURs). In 2011 EPA issued a SNUR on multi-walled carbon nanotubes, codified as . Other statutes falling in the EPA's jurisdiction may apply, such as Federal Insecticide, Fungicide, and Rodenticide Act (if bacterial claims are being made), Clean Air Act, or Clean Water Act. EPA regulates nanomaterials under the same provisions as other hazardous chemical substances.
Other countries
In the European Union, nanomaterials classified by the European Commission as hazardous chemical substances are regulated under the European Chemical Agency's Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulation, as well as the Classification, Labeling, and Packaging (CLP) regulations. Under the REACH regulation, companies have the responsibility of collecting information on the properties and uses of substances that they manufacture or import at or above quantities of 1 ton per year, including nanomaterials. There are special provisions for cosmetics that contain nanomaterials, and for biocidal materials under the Biocidal Products Regulation (BPR) when at least 50% of their primary particles are nanoparticles.
In the United Kingdom, powders of nanomaterials may fall under the Chemicals (Hazard Information and Packaging for Supply) Regulations 2002, as well as the Dangerous Substances and Explosive Atmosphere Regulations 2002 if they are capable of fueling a dust explosion.
See also
Construction | Construction waste
Diesel particulate matter
Laboratory safety
Power tool
Renovation
Toxicology of carbon nanomaterials
Ultrafine particles
References
Nanomaterials
Occupational hazards
Chemical safety
Occupational safety and health | Health and safety hazards of nanomaterials | [
"Chemistry",
"Materials_science"
] | 5,613 | [
"Chemical accident",
"nan",
"Nanotechnology",
"Chemical safety",
"Nanomaterials"
] |
53,377,604 | https://en.wikipedia.org/wiki/Marine%20biogeochemical%20cycles | Marine biogeochemical cycles are biogeochemical cycles that occur within marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. These biogeochemical cycles are the pathways chemical substances and elements move through within the marine environment. In addition, substances and elements can be imported into or exported from the marine environment. These imports and exports can occur as exchanges with the atmosphere above, the ocean floor below, or as runoff from the land.
There are biogeochemical cycles for the elements calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, and sulfur; molecular cycles for water and silica; macroscopic cycles such as the rock cycle; as well as human-induced cycles for synthetic compounds such as polychlorinated biphenyl (PCB). In some cycles there are reservoirs where a substance can be stored for a long time. The cycling of these elements is interconnected.
Marine organisms, and particularly marine microorganisms are crucial for the functioning of many of these cycles. The forces driving biogeochemical cycles include metabolic processes within organisms, geological processes involving the Earth's mantle, as well as chemical reactions among the substances themselves, which is why these are called biogeochemical cycles. While chemical substances can be broken down and recombined, the chemical elements themselves can be neither created nor destroyed by these forces, so apart from some losses to and gains from outer space, elements are recycled or stored (sequestered) somewhere on or within the planet.
Overview
Energy flows directionally through ecosystems, entering as sunlight (or inorganic molecules for chemoautotrophs) and leaving as heat during the many transfers between trophic levels. However, the matter that makes up living organisms is conserved and recycled. The six most common elements associated with organic molecules—carbon, nitrogen, hydrogen, oxygen, phosphorus, and sulfur—take a variety of chemical forms and may exist for long periods in the atmosphere, on land, in water, or beneath the Earth's surface. Geologic processes, such as weathering, erosion, water drainage, and the subduction of the continental plates, all play a role in this recycling of materials. Because geology and chemistry have major roles in the study of this process, the recycling of inorganic matter between living organisms and their environment is called a biogeochemical cycle.
The six aforementioned elements are used by organisms in a variety of ways. Hydrogen and oxygen are found in water and organic molecules, both of which are essential to life. Carbon is found in all organic molecules, whereas nitrogen is an important component of nucleic acids and proteins. Phosphorus is used to make nucleic acids and the phospholipids that comprise biological membranes. Sulfur is critical to the three-dimensional shape of proteins. The cycling of these elements is interconnected. For example, the movement of water is critical for leaching sulfur and phosphorus into rivers which can then flow into oceans. Minerals cycle through the biosphere between the biotic and abiotic components and from one organism to another.
The water cycle
Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles.
Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances. This ability allows it to be the "solvent of life" Water is also the only common substance that exists as solid, liquid, and gas in normal terrestrial conditions. Since liquid water flows, ocean waters cycle and flow in currents around the world. Since water easily changes phase, it can be carried into the atmosphere as water vapour or frozen as an iceberg. It can then precipitate or melt to become liquid water again. All marine life is immersed in water, the matrix and womb of life itself. Water can be broken down into its constituent hydrogen and oxygen by metabolic or abiotic processes, and later recombined to become water again.
While the water cycle is itself a biogeochemical cycle, flow of water over and beneath the Earth is a key component of the cycling of other biogeochemicals. Runoff is responsible for almost all of the transport of eroded sediment and phosphorus from land to waterbodies. Cultural eutrophication of lakes is primarily due to phosphorus, applied in excess to agricultural fields in fertilizers, and then transported overland and down rivers. Both runoff and groundwater flow play significant roles in transporting nitrogen from the land to waterbodies. The dead zone at the outlet of the Mississippi River is a consequence of nitrates from fertilizer being carried off agricultural fields and funnelled down the river system to the Gulf of Mexico. Runoff also plays a part in the carbon cycle, again through the transport of eroded rock and soil.
Ocean salinity
Ocean salinity is derived mainly from the weathering of rocks and the transport of dissolved salts from the land, with lesser contributions from hydrothermal vents in the seafloor. Evaporation of ocean water and formation of sea ice further increase the salinity of the ocean. However these processes which increase salinity are continually counterbalanced by processes that decrease salinity, such as the continuous input of fresh water from rivers, precipitation of rain and snow, and the melting of ice. The two most prevalent ions in seawater are chloride and sodium. Together, they make up around 85 per cent of all dissolved ions in the ocean. Magnesium and sulfate ions make up most of the rest. Salinity varies with temperature, evaporation, and precipitation. It is generally low at the equator and poles, and high at mid-latitudes.
Sea spray
A stream of airborne microorganisms circles the planet above weather systems but below commercial air lanes. Some peripatetic microorganisms are swept up from terrestrial dust storms, but most originate from marine microorganisms in sea spray. In 2018, scientists reported that hundreds of millions of viruses and tens of millions of bacteria are deposited daily on every square meter around the planet. This is another example of water facilitating the transport of organic material over great distances, in this case in the form of live microorganisms.
Dissolved salt does not evaporate back into the atmosphere like water, but it does form sea salt aerosols in sea spray. Many physical processes over ocean surface generate sea salt aerosols. One common cause is the bursting of air bubbles, which are entrained by the wind stress during the whitecap formation. Another is tearing of drops from wave tops. The total sea salt flux from the ocean to the atmosphere is about 3300 Tg (3.3 billion tonnes) per year.
Ocean circulation
Solar radiation affects the oceans: warm water from the Equator tends to circulate toward the poles, while cold polar water heads towards the Equator. The surface currents are initially dictated by surface wind conditions. The trade winds blow westward in the tropics, and the westerlies blow eastward at mid-latitudes. This wind pattern applies a stress to the subtropical ocean surface with negative curl across the Northern Hemisphere, and the reverse across the Southern Hemisphere. The resulting Sverdrup transport is equatorward. Because of conservation of potential vorticity caused by the poleward-moving winds on the subtropical ridge's western periphery and the increased relative vorticity of poleward moving water, transport is balanced by a narrow, accelerating poleward current, which flows along the western boundary of the ocean basin, outweighing the effects of friction with the cold western boundary current which originates from high latitudes. The overall process, known as western intensification, causes currents on the western boundary of an ocean basin to be stronger than those on the eastern boundary.
As it travels poleward, warm water transported by strong warm water current undergoes evaporative cooling. The cooling is wind driven: wind moving over water cools the water and also causes evaporation, leaving a saltier brine. In this process, the water becomes saltier and denser. and decreases in temperature. Once sea ice forms, salts are left out of the ice, a process known as brine exclusion. These two processes produce water that is denser and colder. The water across the northern Atlantic Ocean becomes so dense that it begins to sink down through less salty and less dense water. This downdraft of heavy, cold and dense water becomes a part of the North Atlantic Deep Water, a southgoing stream.
Winds drive ocean currents in the upper 100 meters of the ocean's surface. However, ocean currents also flow thousands of meters below the surface. These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation. In the Earth's polar regions ocean water gets very cold, forming sea ice. As a consequence the surrounding seawater gets saltier, because when sea ice forms, the salt is left behind. As the seawater gets saltier, its density increases, and it starts to sink. Surface water is pulled in to replace the sinking water, which in turn eventually becomes cold and salty enough to sink. This initiates the deep-ocean currents driving the global conveyor belt.
Thermohaline circulation drives a global-scale system of currents called the “global conveyor belt.” The conveyor belt begins on the surface of the ocean near the pole in the North Atlantic. Here, the water is chilled by Arctic temperatures. It also gets saltier because when sea ice forms, the salt does not freeze and is left behind in the surrounding water. The cold water is now more dense, due to the added salts, and sinks toward the ocean bottom. Surface water moves in to replace the sinking water, thus creating a current. This deep water moves south, between the continents, past the equator, and down to the ends of Africa and South America. The current travels around the edge of Antarctica, where the water cools and sinks again, as it does in the North Atlantic. Thus, the conveyor belt gets "recharged." As it moves around Antarctica, two sections split off the conveyor and turn northward. One section moves into the Indian Ocean, the other into the Pacific Ocean. These two sections that split off warm up and become less dense as they travel northward toward the equator, so that they rise to the surface (upwelling). They then loop back southward and westward to the South Atlantic, eventually returning to the North Atlantic, where the cycle begins again. The conveyor belt moves at much slower speeds (a few centimeters per second) than wind-driven or tidal currents (tens to hundreds of centimeters per second). It is estimated that any given cubic meter of water takes about 1,000 years to complete the journey along the global conveyor belt. In addition, the conveyor moves an immense volume of water—more than 100 times the flow of the Amazon River (Ross, 1995). The conveyor belt is also a vital component of the global ocean nutrient and carbon dioxide cycles. Warm surface waters are depleted of nutrients and carbon dioxide, but they are enriched again as they travel through the conveyor belt as deep or bottom layers. The base of the world's food chain depends on the cool, nutrient-rich waters that support the growth of algae and seaweed.
The global average residence time of a water molecule in the ocean is about 3,200 years. By comparison the average residence time in the atmosphere is about nine days. If it is frozen in the Antarctic or drawn into deep groundwater it can be sequestered for ten thousand years.
Cycling of key elements
Box models
Box models are widely used to model biogeochemical systems. Box models are simplified versions of complex systems, reducing them to boxes (or storage reservoirs) for chemical materials, linked by material fluxes (flows). Simple box models have a small number of boxes with properties, such as volume, that do not change with time. The boxes are assumed to behave as if they were mixed homogeneously. These models are often used to derive analytical formulas describing the dynamics and steady-state abundance of the chemical species involved.
The diagram at the right shows a basic one-box model. The reservoir contains the amount of material M under consideration, as defined by chemical, physical or biological properties. The source Q is the flux of material into the reservoir, and the sink S is the flux of material out of the reservoir. The budget is the check and balance of the sources and sinks affecting material turnover in a reservoir. The reservoir is in a steady state if Q = S, that is, if the sources balance the sinks and there is no change over time.
The turnover time (also called the renewal time or exit age) is the average time material spends resident in the reservoir. If the reservoir is in a steady state, this is the same as the time it takes to fill or drain the reservoir. Thus, if τ is the turnover time, then τ = M/S. The equation describing the rate of change of content in a reservoir is
When two or more reservoirs are connected, the material can be regarded as cycling between the reservoirs, and there can be predictable patterns to the cyclic flow. More complex multibox models are usually solved using numerical techniques.
The diagram above shows a simplified budget of ocean carbon flows. It is composed of three simple interconnected box models, one for the euphotic zone, one for the ocean interior or dark ocean, and one for ocean sediments. In the euphotic zone, net phytoplankton production is about 50 Pg C each year. About 10 Pg is exported to the ocean interior while the other 40 Pg is respired. Organic carbon degradation occurs as particles (marine snow) settle through the ocean interior. Only 2 Pg eventually arrives at the seafloor, while the other 8 Pg is respired in the dark ocean. In sediments, the time scale available for degradation increases by orders of magnitude with the result that 90% of the organic carbon delivered is degraded and only 0.2 Pg C yr−1 is eventually buried and transferred from the biosphere to the geosphere.
Dissolved and particulate matter
Biological pumps
The biological pump, in its simplest form, is the ocean's biologically driven sequestration of carbon from the atmosphere to the ocean interior and seafloor sediments. It is the part of the oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells by certain organisms such as plankton and mollusks (carbonate pump).
The biological pump can be divided into three distinct phases, the first of which is the production of fixed carbon by planktonic phototrophs in the euphotic (sunlit) surface region of the ocean. In these surface waters, phytoplankton use carbon dioxide (CO2), nitrogen (N), phosphorus (P), and other trace elements (barium, iron, zinc, etc.) during photosynthesis to make carbohydrates, lipids, and proteins. Some plankton, (e.g. coccolithophores and foraminifera) combine calcium (Ca) and dissolved carbonates (carbonic acid and bicarbonate) to form a calcium carbonate (CaCO3) protective coating.
Once this carbon is fixed into soft or hard tissue, the organisms either stay in the euphotic zone to be recycled as part of the regenerative nutrient cycle or once they die, continue to the second phase of the biological pump and begin to sink to the ocean floor. The sinking particles will often form aggregates as they sink, greatly increasing the sinking rate. It is this aggregation that gives particles a better chance of escaping predation and decomposition in the water column and eventually make it to the sea floor.
The fixed carbon that is either decomposed by bacteria on the way down or once on the sea floor then enters the final phase of the pump and is remineralized to be used again in primary production. The particles that escape these processes entirely are sequestered in the sediment and may remain there for millions of years. It is this sequestered carbon that is responsible for ultimately lowering atmospheric CO2.
Brum JR, Morris JJ, Décima M and Stukel MR (2014) "Mortality in the oceans: Causes and consequences". Eco-DAS IX Symposium Proceedings, Chapter 2, pages 16–48. Association for the Sciences of Limnology and Oceanography. .
Mateus, M.D. (2017) "Bridging the gap between knowing and modeling viruses in marine systems—An upcoming frontier". Frontiers in Marine Science, 3: 284.
Beckett, S.J. and Weitz, J.S. (2017) "Disentangling niche competition from grazing mortality in phytoplankton dilution experiments". PLOS ONE, 12(5): e0177517. .
Role of microorganisms
Carbon, oxygen and hydrogen cycles
The marine carbon cycle is composed of processes that exchange carbon between various pools within the ocean as well as between the atmosphere, Earth interior, and the seafloor. The carbon cycle is a result of many interacting forces across multiple time and space scales that circulates carbon around the planet, ensuring that carbon is available globally. The Oceanic carbon cycle is a central process to the global carbon cycle and contains both inorganic carbon (carbon not associated with a living thing, such as carbon dioxide) and organic carbon (carbon that is, or has been, incorporated into a living thing). Part of the marine carbon cycle transforms carbon between non-living and living matter.
Three main processes (or pumps) that make up the marine carbon cycle bring atmospheric carbon dioxide (CO2) into the ocean interior and distribute it through the oceans. These three pumps are: (1) the solubility pump, (2) the carbonate pump, and (3) the biological pump. The total active pool of carbon at the Earth's surface for durations of less than 10,000 years is roughly 40,000 gigatons C (Gt C, a gigaton is one billion tons, or the weight of approximately 6 million blue whales), and about 95% (~38,000 Gt C) is stored in the ocean, mostly as dissolved inorganic carbon. The speciation of dissolved inorganic carbon in the marine carbon cycle is a primary controller of acid-base chemistry in the oceans.
Nitrogen and phosphorus cycles
The nitrogen cycle is as important in the ocean as it is on land. While the overall cycle is similar in both cases, there are different players and modes of transfer for nitrogen in the ocean. Nitrogen enters the ocean through precipitation, runoff, or as N2 from the atmosphere. Nitrogen cannot be utilized by phytoplankton as N2 so it must undergo nitrogen fixation which is performed predominantly by cyanobacteria. Without supplies of fixed nitrogen entering the marine cycle, the fixed nitrogen would be used up in about 2000 years. Phytoplankton need nitrogen in biologically available forms for the initial synthesis of organic matter. Ammonia and urea are released into the water by excretion from plankton. Nitrogen sources are removed from the euphotic zone by the downward movement of the organic matter. This can occur from sinking of phytoplankton, vertical mixing, or sinking of waste of vertical migrators. The sinking results in ammonia being introduced at lower depths below the euphotic zone. Bacteria are able to convert ammonia to nitrite and nitrate but they are inhibited by light so this must occur below the euphotic zone. Ammonification or mineralization is performed by bacteria to convert organic nitrogen to ammonia. Nitrification can then occur to convert the ammonium to nitrite and nitrate. Nitrate can be returned to the euphotic zone by vertical mixing and upwelling where it can be taken up by phytoplankton to continue the cycle. N2 can be returned to the atmosphere through denitrification.
Ammonium is thought to be the preferred source of fixed nitrogen for phytoplankton because its assimilation does not involve a redox reaction and therefore requires little energy. Nitrate requires a redox reaction for assimilation but is more abundant so most phytoplankton have adapted to have the enzymes necessary to undertake this reduction (nitrate reductase). There are a few notable and well-known exceptions that include most Prochlorococcus and some Synechococcus that can only take up nitrogen as ammonium.
Phosphorus is an essential nutrient for plants and animals. Phosphorus is a limiting nutrient for aquatic organisms. Phosphorus forms parts of important life-sustaining molecules that are very common in the biosphere. Phosphorus does enter the atmosphere in very small amounts when the dust is dissolved in rainwater and seaspray but remains mostly on land and in rock and soil minerals. Eighty per cent of the mined phosphorus is used to make fertilizers. Phosphates from fertilizers, sewage and detergents can cause pollution in lakes and streams. Over-enrichment of phosphate in both fresh and inshore marine waters can lead to massive algae blooms which, when they die and decay leads to eutrophication of freshwaters only. Recent research suggests that the predominant pollutant responsible for algal blooms in saltwater estuaries and coastal marine habitats is nitrogen.
Phosphorus occurs most abundantly in nature as part of the orthophosphate ion (PO4)3−, consisting of a P atom and 4 oxygen atoms. On land most phosphorus is found in rocks and minerals. Phosphorus-rich deposits have generally formed in the ocean or from guano, and over time, geologic processes bring ocean sediments to land. Weathering of rocks and minerals release phosphorus in a soluble form where it is taken up by plants, and it is transformed into organic compounds. The plants may then be consumed by herbivores and the phosphorus is either incorporated into their tissues or excreted. After death, the animal or plant decays, and phosphorus is returned to the soil where a large part of the phosphorus is transformed into insoluble compounds. Runoff may carry a small part of the phosphorus back to the ocean.
Nutrient cycle
A nutrient cycle is the movement and exchange of organic and inorganic matter back into the production of matter. The process is regulated by the pathways available in marine food webs, which ultimately decompose organic matter back into inorganic nutrients. Nutrient cycles occur within ecosystems. Energy flow always follows a unidirectional and noncyclic path, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, oxygen cycle, nitrogen cycle, phosphorus cycle and sulfur cycle among others that continually recycle along with other mineral nutrients into productive ecological nutrition.
There is considerable overlap between the terms for the biogeochemical cycle and nutrient cycle. Some textbooks integrate the two and seem to treat them as synonymous terms. However, the terms often appear independently. Nutrient cycle is more often used in direct reference to the idea of an intra-system cycle, where an ecosystem functions as a unit. From a practical point, it does not make sense to assess a terrestrial ecosystem by considering the full column of air above it as well as the great depths of Earth below it. While an ecosystem often has no clear boundary, as a working model it is practical to consider the functional community where the bulk of matter and energy transfer occurs. Nutrient cycling occurs in ecosystems that participate in the "larger biogeochemical cycles of the earth through a system of inputs and outputs."
Dissolved nutrients
Nutrients dissolved in seawater are essential for the survival of marine life. Nitrogen and phosphorus are particularly important. They are regarded as limiting nutrients in many marine environments, because primary producers, like algae and marine plants, cannot grow without them. They are critical for stimulating primary production by phytoplankton. Other important nutrients are silicon, iron, and zinc.
The process of cycling nutrients in the sea starts with biological pumping, when nutrients are extracted from surface waters by phytoplankton to become part of their organic makeup. Phytoplankton are either eaten by other organisms, or eventually die and drift down as marine snow. There they decay and return to the dissolved state, but at greater ocean depths. The fertility of the oceans depends on the abundance of the nutrients, and is measured by the primary production, which is the rate of fixation of carbon per unit of water per unit time. "Primary production is often mapped by satellites using the distribution of chlorophyll, which is a pigment produced by plants that absorbs energy during photosynthesis. The distribution of chlorophyll is shown in the figure above. You can see the highest abundance close to the coastlines where nutrients from the land are fed in by rivers. The other location where chlorophyll levels are high is in upwelling zones where nutrients are brought to the surface ocean from depth by the upwelling process..."
"Another critical element for the health of the oceans is the dissolved oxygen content. Oxygen in the surface ocean is continuously added across the air-sea interface as well as by photosynthesis; it is used up in respiration by marine organisms and during the decay or oxidation of organic material that rains down in the ocean and is deposited on the ocean bottom. Most organisms require oxygen, thus its depletion has adverse effects for marine populations. Temperature also affects oxygen levels as warm waters can hold less dissolved oxygen than cold waters. This relationship will have major implications for future oceans, as we will see... The final seawater property we will consider is the content of dissolved . is nearly opposite to oxygen in many chemical and biological processes; it is used up by plankton during photosynthesis and replenished during respiration as well as during the oxidation of organic matter. As we will see later, content has importance for the study of deep-water aging."
Marine sulfur cycle
Sulfate reduction in the seabed is strongly focused toward near-surface sediments with high depositional rates along the ocean margins. The benthic marine sulfur cycle is therefore sensitive to anthropogenic influence, such as ocean warming and increased nutrient loading of coastal seas. This stimulates photosynthetic productivity and results in enhanced export of organic matter to the seafloor, often combined with low oxygen concentration in the bottom water (Rabalais et al., 2014; Breitburg et al., 2018). The biogeochemical zonation is thereby compressed toward the sediment surface, and the balance of organic matter mineralization is shifted from oxic and suboxic processes toward sulfate reduction and methanogenesis (Middelburg and Levin, 2009).
cable bacteria
The sulfur cycle in marine environments has been well-studied via the tool of sulfur isotope systematics expressed as δ34S. The modern global oceans have sulfur storage of 1.3 × 1021 g, mainly occurring as sulfate with the δ34S value of +21‰. The overall input flux is 1.0 × 1014 g/year with the sulfur isotope composition of ~3‰. Riverine sulfate derived from the terrestrial weathering of sulfide minerals (δ34S = +6‰) is the primary input of sulfur to the oceans. Other sources are metamorphic and volcanic degassing and hydrothermal activity (δ34S = 0‰), which release reduced sulfur species (e.g., H2S and S0). There are two major outputs of sulfur from the oceans. The first sink is the burial of sulfate either as marine evaporites (e.g., gypsum) or carbonate-associated sulfate (CAS), which accounts for 6 × 1013 g/year (δ34S = +21‰). The second sulfur sink is pyrite burial in shelf sediments or deep seafloor sediments (4 × 1013 g/year; δ34S = -20‰). The total marine sulfur output flux is 1.0 × 1014 g/year which matches the input fluxes, implying the modern marine sulfur budget is at steady state. The residence time of sulfur in modern global oceans is 13,000,000 years.
In modern oceans, Hydrogenovibrio crunogenus, Halothiobacillus, and Beggiatoa are primary sulfur oxidizing bacteria, and form chemosynthetic symbioses with animal hosts. The host provides metabolic substrates (e.g., CO2, O2, H2O) to the symbiont while the symbiont generates organic carbon for sustaining the metabolic activities of the host. The produced sulfate usually combines with the leached calcium ions to form gypsum, which can form widespread deposits on near mid-ocean spreading centers.
Hydrothermal vents emit hydrogen sulfide that support the carbon fixation of chemolithotrophic bacteria that oxidize hydrogen sulfide with oxygen to produce elemental sulfur or sulfate.
Iron cycle and dust
The iron cycle (Fe) is the biogeochemical cycle of iron through the atmosphere, hydrosphere, biosphere and lithosphere. While Fe is highly abundant in the Earth's crust, it is less common in oxygenated surface waters. Iron is a key micronutrient in primary productivity, and a limiting nutrient in the Southern ocean, eastern equatorial Pacific, and the subarctic Pacific referred to as High-Nutrient, Low-Chlorophyll (HNLC) regions of the ocean.
Iron in the ocean cycles between plankton, aggregated particulates (non-bioavailable iron), and dissolved (bioavailable iron), and becomes sediments through burial. Hydrothermal vents release ferrous iron to the ocean in addition to oceanic iron inputs from land sources. Iron reaches the atmosphere through volcanism, aeolian wind, and some via combustion by humans. In the Anthropocene, iron is removed from mines in the crust and a portion re-deposited in waste repositories.
Iron is an essential micronutrient for almost every life form. It is a key component of hemoglobin, important to nitrogen fixation as part of the Nitrogenase enzyme family, and as part of the iron-sulfur core of ferredoxin it facilitates electron transport in chloroplasts, eukaryotic mitochondria, and bacteria. Due to the high reactivity of Fe2+ with oxygen and low solubility of Fe3+, iron is a limiting nutrient in most regions of the world.
Calcium and silica cycles
The calcium cycle is a transfer of calcium between dissolved and solid phases. There is a continuous supply of calcium ions into waterways from rocks, organisms, and soils. Calcium ions are consumed and removed from aqueous environments as they react to form insoluble structures such as calcium carbonate and calcium silicate, which can deposit to form sediments or the exoskeletons of organisms. Calcium ions can also be utilized biologically, as calcium is essential to biological functions such as the production of bones and teeth or cellular function. The calcium cycle is a common thread between terrestrial, marine, geological, and biological processes. Calcium moves through these different media as it cycles throughout the Earth. The marine calcium cycle is affected by changing atmospheric carbon dioxide due to ocean acidification.
Biogenic calcium carbonate is formed when marine organisms, such as coccolithophores, corals, pteropods, and other mollusks transform calcium ions and bicarbonate into shells and exoskeletons of calcite or aragonite, both forms of calcium carbonate. This is the dominant sink for dissolved calcium in the ocean. Dead organisms sink to the bottom of the ocean, depositing layers of shell which over time cement to form limestone. This is the origin of both marine and terrestrial limestone.
Calcium precipitates into calcium carbonate according to the following equation:
Ca2+ + 2HCO3− → CO2+ H2O + CaCO3
The relationship between dissolved calcium and calcium carbonate is affected greatly by the levels of carbon dioxide (CO2) in the atmosphere.
Increased carbon dioxide leads to more bicarbonate in the ocean according to the following equation:
CO2 + CO32− + H2O → 2HCO3−
With its close relation to the carbon cycle and the effects of greenhouse gasses, both calcium and carbon cycles are predicted to change in the coming years. Tracking calcium isotopes enables the prediction of environmental changes, with many sources suggesting increasing temperatures in both the atmosphere and marine environment. As a result, this will drastically alter the breakdown of rock, the pH of oceans and waterways and thus calcium sedimentation, hosting an array of implications on the calcium cycle.
Due to the complex interactions of calcium with many facets of life, the effects of altered environmental conditions are unlikely to be known until they occur. Predictions can however be tentatively made, based upon evidence-based research. Increasing carbon dioxide levels and decreasing ocean pH will alter calcium solubility, preventing corals and shelled organisms from developing their calcium-based exoskeletons, thus making them vulnerable or unable to survive.
Most biological production of biogenic silica in the ocean is driven by diatoms, with further contributions from radiolarians. These microorganisms extract dissolved silicic acid from surface waters during growth, and return this by recycling throughout the water column after they die. Inputs of silicon to the ocean from above arrive via rivers and aeolian dust, while those from below include seafloor sediment recycling, weathering, and hydrothermal activity.
Biomineralization
"Biological activity is a dominant force shaping the chemical structure and evolution of the earth surface environment. The presence of an oxygenated atmosphere-hydrosphere surrounding an otherwise highly reducing solid earth is the most striking consequence of the rise of life on earth. Biological evolution and the functioning of ecosystems, in turn, are to a large degree conditioned by geophysical and geological processes. Understanding the interactions between organisms and their abiotic environment, and the resulting coupled evolution of the biosphere and geosphere is a central theme of research in biogeology. Biogeochemists contribute to this understanding by studying the transformations and transport of chemical substrates and products of biological activity in the environment."
"Since the Cambrian explosion, mineralized body parts have been secreted in large quantities by biota. Because calcium carbonate, silica and calcium phosphate are the main mineral phases constituting these hard parts, biomineralization plays an important role in the global biogeochemical cycles of carbon, calcium, silicon and phosphorus"
Deep cycling
Deep cycling involves the exchange of materials with the mantle. The deep water cycle involves exchange of water with the mantle, with water carried down by subducting oceanic plates and returning through volcanic activity, distinct from the water cycle process that occurs above and on the surface of Earth. Some of the water makes it all the way to the lower mantle and may even reach the outer core.
In the conventional view of the water cycle (also known as the hydrologic cycle), water moves between reservoirs in the atmosphere and Earth's surface or near-surface (including the ocean, rivers and lakes, glaciers and polar ice caps, the biosphere and groundwater). However, in addition to the surface cycle, water also plays an important role in geological processes reaching down into the crust and mantle. Water content in magma determines how explosive a volcanic eruption is; hot water is the main conduit for economically important minerals to concentrate in hydrothermal mineral deposits; and water plays an important role in the formation and migration of petroleum. Petroleum is a fossil fuel derived from ancient fossilized organic materials, such as zooplankton and algae.
Water is not just present as a separate phase in the ground. Seawater percolates into oceanic crust and hydrates igneous rocks such as olivine and pyroxene, transforming them into hydrous minerals such as serpentines, talc and brucite. In this form, water is carried down into the mantle. In the upper mantle, heat and pressure dehydrates these minerals, releasing much of it to the overlying mantle wedge, triggering the melting of rock that rises to form volcanic arcs. However, some of the "nominally anhydrous minerals" that are stable deeper in the mantle can store small concentrations of water in the form of hydroxyl (OH−), and because they occupy large volumes of the Earth, they are capable of storing at least as much as the world's oceans.
The conventional view of the ocean's origin is that it was filled by outgassing from the mantle in the early Archean and the mantle has remained dehydrated ever since. However, subduction carries water down at a rate that would empty the ocean in 1–2 billion years. Despite this, changes in the global sea level over the past 3–4 billion years have only been a few hundred metres, much smaller than the average ocean depth of 4 kilometres. Thus, the fluxes of water into and out of the mantle are expected to be roughly balanced, and the water content of the mantle steady. Water carried into the mantle eventually returns to the surface in eruptions at mid-ocean ridges and hotspots. Estimates of the amount of water in the mantle range from to 4 times the water in the ocean.
The deep carbon cycle is the movement of carbon through the Earth's mantle and core.
It forms part of the carbon cycle and is intimately connected to the movement of carbon in the Earth's surface and atmosphere. By returning carbon to the deep Earth, it plays a critical role in maintaining the terrestrial conditions necessary for life to exist. Without it, carbon would accumulate in the atmosphere, reaching extremely high concentrations over long periods of time.
Rock cycle
Fossil fuels
Aquatic phytoplankton and zooplankton that died and sedimented in large quantities under anoxic conditions millions of years ago began forming petroleum and natural gas as a result of anaerobic decomposition (by contrast, terrestrial plants tended to form coal and methane). Over geological time this organic matter, mixed with mud, became buried under further heavy layers of inorganic sediment. The resulting high temperature and pressure caused the organic matter to chemically alter, first into a waxy material known as kerogen, which is found in oil shales, and then with more heat into liquid and gaseous hydrocarbons in a process known as catagenesis.
Such organisms and their resulting fossil fuels typically have an age of millions of years, and sometimes more than 650 million years, the energy released in combustion is still photosynthetic in origin.
Other cycles
Such as trace minerals, micronutrients, human-induced cycles for synthetic compounds such as polychlorinated biphenyl (PCB).
References
Further references
James, Rachael and Open University (2005) Marine Biogeochemical Cycles Butterworth-Heinemann. .
Biogeochemical cycle
Geochemistry
Biogeography
Marine organisms
Oceanography | Marine biogeochemical cycles | [
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"Biogeography",
"Biogeochemical cycle",
"Biogeochemistry",
"nan"
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53,377,813 | https://en.wikipedia.org/wiki/Kavita%20Shah%20%28scientist%29 | Kavita Shah is (born 6 November 1968) an Indian environmental biotechnologist and professor at the Institute of Environmental and Sustainable Development, Banaras Hindu University on lien. She currently serves as vice-chancellor of Siddharth University from July 2024 for a term of three years and becomes the first woman to hold the post. She is one of the six directors and the only woman director of Banaras Hindu University (BHU). She is known for her role in the area of Environmental Biotechnology, Health and water Resource Management.
She has completed her MSc, B.Ed., Ph.D. and some post-docs and then she taught at NEHU and completed three more post-docs there. She started as a Zoology student in the women's college at BHU named Mahila Mahavidyalaya (MMV). Following stints in Japan, Geneva and North Eastern Hill University in Shillong, she found herself coming back as a teacher at BHU.
A major area of work also include the development of biosensors using immobilized plant enzymes (Biotechnology and Bio process Engineering, 13, 632–638, 2008) and studies pertaining to inhibitors of HIV protease (In Silico Biology, 8–033, 2008), HIV integrase (Archives of Virology 2014) and N. meningitides vaccine constructs (Indian Journal of Biotechnology, 2010) in silico using bioinformatics tools.
References
External links
Biotechnology Career Advancement link
Year of birth missing (living people)
Living people
Indian environmental scientists
Indian biotechnologists | Kavita Shah (scientist) | [
"Environmental_science"
] | 336 | [
"Indian environmental scientists",
"Environmental scientists"
] |
53,378,620 | https://en.wikipedia.org/wiki/Erycina%20pusilla | Erycina pusilla is a species of flowering plants, which is a tiny orchid with an overall size of 2.5 to 3.5 cm from the orchid family, Orchidaceae. Its species are native to Mexico, Belize, Central America, South America and Trinidad.
The leaves are shaped like a lance head (lanceolate) and arranged in a fan. Unlike other similar orchids, E. pusilla never develops lengthwise folded leaves (conduplicate leaves) or extra storage organs (pseudobulbs).
The blooming season is from fall to spring. It produces solitary light-yellow orchid-shaped flowers. In comparison to the overall plant size, these flowers can reach a relatively large size (1 to 2.5 cm). The lateral sepals are united near the flower base.
Compared to other orchids, E. pusilla has a short life cycle (about 17 months). It can reach adulthood in just one season, while the majority of the orchids reach maturity in up to 5 years.
Name
It is commonly known as the tiny psygmorchis, due to its miniature size.
The current scientific name is Erycina pusilla. The etymology of its scientific name refers to its beauty and tiny size: “Erycina” is a byname of the Roman goddess for beauty, Venus (Venus of Eryx), and “pusilla” is Latin meaning “very little”. It was formerly classified in the genus Psygmorchis, due to its fan-shaped leaves (“psygmos” Greek for fan).
Synonyms
Homotypic synonyms:
Epidendrum pusillum L., Sp. Pl. ed. 2: 1352 (1763)
Cymbidium pusillum (L.) Sw., Nova Acta Regiae Soc. Sci. Upsal. 6: 74 (1799).
Oncidium pusillum (L.) Mutel, Mém. Soc. Roy. Centr. Agric. Dépt. N. 1835-1836: 84 (1837).
Tolumnia pusilla (L.) Hoehne, Ic. Orch. Bras.: 231 (1949).
Psygmorchis pusilla (L.) Dodson & Dressler, Phytologia 24: 288 (1972).
Heterotypic synonyms:
Oncidium iridifolium Kunth in F.W.H.von Humboldt, A.J.A.Bonpland & C.S.Kunth, Nov. Gen. Sp. 1: 344 (1816).
Epidendrum ventilabrum Vell., Fl. Flumin. 9: t. 32 (1831).
Oncidium allemanii Barb.Rodr., Gen. Spec. Orchid. 2: 185 (1882).
Oncidium pusillum var. megalanthum Schltr., Repert. Spec. Nov. Regni Veg. Beih. 27: 115 (1924).
Psygmorchis allemanii (Barb.Rodr.) Garay & Stacy, Bradea 1: 408 (1974).
Erycina allemanii (Barb.Rodr.) N.H.Williams & M.W.Chase, Lindleyana 16: 136 (2001).
Distribution and habitat
Erycina pusilla can be found in the neotropical region, including South and Central America, the southern Mexican lowlands, the Caribbean islands and southern Florida.
Its habitat consists of humid forests at elevations of with temperatures varying from warm to hot. Like many orchids, E. pusilla grows harmlessly upon other plants. It gets moisture and nutrients from the surroundings without affecting the host plant (commensalism).
Its quick development permits this orchid to grow on relatively short-lasting sites such as twigs or even leaves of bushes and trees, such as coffee plant or hibiscus. For this reason, it is usually classified as a twig epiphyte.
Use in science
Erycina pusilla is a promising model candidate for Oncidium research. Its relatively tiny size and its short life cycle, facilitates its cultivation. Additionally, it has the ability to complete its life cycle in vitro. The functional genomic research is easier because E. pusilla only has 6 chromosomes and a small genome size (1.5 pg 1C nucleus). Another aspect that speaks for the use of this orchid in research, is the rare pollination and production of seeds in nature. This reduces the risk of undesired propagation of transgenic lines. The rapid growth and the low chromosome numbers make E. pusilla is also an excellent parent for traditional hybridization methods. All these characteristics make E. pusilla a promising model not only for research, but also for commercial breeding, since it constitutes an excellent parent for traditional hybridization methods.
Beyond the use of this orchid for research and commercial purposes, E. pusilla has also medical applications. The ingestion of whole plant cooked treats colic and stomachache. Additionally, the whole plant boiled is also used as a wash to treat lacerations cuts and wounds.
In vitro cultivation
Sporadic flowering in flasks was first reported by Livingston (1962), although the in vitro cultivation was just established (2007). The primary culture of E. pusilla becomes a callus after about one month of cultivation. Three months later it reaches leaf stage and after eight months the flowering stage begins. After two and half months E. pusilla produces fruits. A new cycle can start from a new primary culture: protocorm-like body (PLB) in vitro.
Genome
The transcriptome sequence of E. pusilla is available (Orchidstra Database). Some basic molecular resources were also established, including the sequencing of the chloroplast genome, the transcriptome and the BAC library. The miRNA database of E. pusilla, including the identification of miRNA biosynthesis-related genes and miRNA families, was established in 2013.
The chloroplast genome has been sequenced efficiently and economically by using BAC library and next-generation sequencing. The chloroplast genome of E. pusilla is 143.164 bp in size, which contains a pair of inverted repeats (IRa and IRb) of 23.439 bp separated by large and small single copy regions of 84.189 and 12.097 bp, respectively. From these result compare to Oncidium, the gene order of chloroplast genome between E. pusilla and Oncidium are similar. In Taiwan, different hybridization compatibility of E. pusilla with Oncidium, Rodriguezia and Tolumnia was found by crossing with several important Oncidiinae orchids.
MADS-box genes
Due to their role in plant growth, the characterization of MADS-box genes in E. pusilla has turned into a hot topic for both researchers and commercial orchid breeders. MADS-box genes encode for MADS-domain proteins, which are generally transcription factors. In plants, these proteins control key developmental processes throughout almost all life stages.
To date, 28 MADS-box genes were isolated in E. pusilla, namely EpMADS1 to 28. Nearly all of them contain introns greater than 10 kb, which reflects the complexity of the E. pusilla genome. Many EpMADS genes have expression patterns similar to those MADS-box genes in Arabidopsis. The 28 proteins, encoded by the E. pusilla MADS-box genes, are classified as type I or type II based on BLASTP analyses.
References
Other sources
Pridgeon, A.M., Cribb, P.J., Chase, M.A. & Rasmussen, F. eds. (1999). Genera Orchidacearum Vols 1–3. Oxford Univ. Press.
Berg Pana, H. 2005. Handbuch der Orchideen-Namen. Dictionary of Orchid Names. Dizionario dei nomi delle orchidee. Ulmer, Stuttgart.
Establishment of an Agrobacterium-mediated genetic transformation procedure for the experimental model orchid Erycina pusilla. Shu-Hong Lee, Chia-Wen Li, Chia-Hui, Liau Pao-Yi, Chang Li-Jen Liao, Choun-Sea Lin Ming-Tsair Chan, Plant Cell, Tissue and Organ Culture, January 2015, Volume 120, Issue 1, pp 211–220
External links
Oncidiinae
Plant models
Orchids of Central America
Orchids of Belize | Erycina pusilla | [
"Biology"
] | 1,800 | [
"Model organisms",
"Plant models"
] |
53,382,074 | https://en.wikipedia.org/wiki/George%20Cresswell%20Furnace | George Cresswell Furnace, also known as the George Cresswell Furnace Stack is a historic lead furnace located near Potosi, Washington County, Missouri. It was built about 1840, and is an open hearth furnace measuring about 100 feet square at its base and constructed of massive limestone blocks interlaced with mortar. The stack rises to a height of approximately 25 feet.
It was listed on the National Register of Historic Places in 1988.
References
Industrial buildings and structures on the National Register of Historic Places in Missouri
Industrial buildings completed in 1840
Buildings and structures in Washington County, Missouri
National Register of Historic Places in Washington County, Missouri
Lead
Smelting | George Cresswell Furnace | [
"Chemistry"
] | 130 | [
"Metallurgical processes",
"Smelting"
] |
62,244,367 | https://en.wikipedia.org/wiki/International%20Medal | The International Medal is an award presented by the Royal Academy of Engineering in the UK, to individuals who are non-UK citizens or residents. It is awarded to individuals who have made exceptional contributions to engineering.
Background
The medal is given annually to recognize individuals who have made sustained personal achievements in any field of engineering. Individuals are foreign nationals who are not citizens nor residents of the UK.
Winners
Source: RAE
2011 Andrew Viterbi
2008 Abdul Kalam
2007 Xu Kuangdi
2006 Cham Tao Soon
See also
List of engineering awards
References
International awards
Awards established in 1991
Awards of the Royal Academy of Engineering | International Medal | [
"Technology"
] | 121 | [
"Science and technology awards",
"International science and technology awards"
] |
62,247,933 | https://en.wikipedia.org/wiki/Lemon%20%28geometry%29 | In geometry, a lemon is a geometric shape that is constructed as the surface of revolution of a circular arc of angle less than half of a full circle rotated about an axis passing through the endpoints of the lens (or arc). The surface of revolution of the complementary arc of the same circle, through the same axis, is called an apple.
The apple and lemon together make up a spindle torus (or self-crossing torus or self-intersecting torus). The lemon forms the boundary of a convex set, while its surrounding apple is non-convex.
The ball in North American football has a shape resembling a geometric lemon. However, although used with a related meaning in geometry, the term "football" is more commonly used to refer to a surface of revolution whose Gaussian curvature is positive and constant, formed from a more complicated curve than a circular arc. Alternatively, a football may refer to a more abstract orbifold, a surface modeled locally on a sphere except at two points.
Area and volume
The lemon is generated by rotating an arc of radius and half-angle less than about its chord. Note that denotes latitude, as used in geophysics. The surface area is given by
The volume is given by
These integrals can be evaluated analytically, giving
The apple is generated by rotating an arc of half-angle greater than about its chord. The above equations are valid for both the lemon and apple.
See also
Sears–Haack body
List of shapes
References
External links
Football shaped (spindle type) surface of positive constant curvature in the University of Groningen model collection
Geometric shapes | Lemon (geometry) | [
"Mathematics"
] | 325 | [
"Geometric shapes",
"Mathematical objects",
"Geometric objects"
] |
62,249,183 | https://en.wikipedia.org/wiki/Loserthink | Loserthink: How Untrained Brains Are Ruining America is a 2019 non-fiction book by Scott Adams, creator of Dilbert. Adams suggests that many otherwise intelligent people are trapped by unproductive ways of thinking. The reason for this, he says, is they don't have experience across multiple domains and thus are not equipped to think more productively. Loserthink introduces readers to the most useful thought patterns in a variety of disciplines. Adams wants to help employees identify mental barriers and how to break through them, as well as escape from their own "mental prisons." Loserthink is a New York Times Best Seller.
The book claims to show you how to think like a psychologist, artist, historian, engineer, leader, scientist and entrepreneur.
Adams has suggested two ideas for a calmer internet: the “48-hour rule,” where everyone should be given a grace period of a couple of days to retract any controversial statement they’ve made, and the “20-year rule,” where everyone should be automatically forgiven for any mistakes they made more than two decades ago—with the exception of certain serious crimes.
Ghostwriter Joshua Lisec said Loserthink's advantage is it appeals to a wide range of audiences.
References
2019 non-fiction books
Personal development
Self-help books
Books by Scott Adams
Portfolio (publisher) books | Loserthink | [
"Biology"
] | 278 | [
"Personal development",
"Behavior",
"Human behavior"
] |
62,252,965 | https://en.wikipedia.org/wiki/Phosphinous%20acids | Phosphinous acids are usually organophosphorus compounds with the formula R2POH. They are pyramidal in structure. Phosphorus is in the oxidation state III. Most phosphinous acids rapidly convert to the corresponding phosphine oxide, which are tetrahedral and are assigned oxidation state V.
Synthesis
Only one example is known, bis(trifluoromethyl)phosphinous acid, (CF3)2POH. It is prepared in several steps from phosphorus trichloride (Et = ethyl):
PCl3 + 2 Et2NH → PCl2NEt2 + Et2NH2Cl
2 P(NEt2)3 + PCl2NEt2 + 2 CF3Br → P(CF3)2NEt2 + 2 BrClP(NEt2)3
P(CF3)2NEt2 + H2O → P(CF3)2OH + HNEt2
Reactions
With the lone exception of the bis(trifluoromethyl) derivative, the dominant reaction of phosphinous acids is tautomerization:
PR2OH → OPR2H
Even the pentafluorophenyl compound P(C6F5)2OH is unstable with respect to the phosphine oxide.
Although phosphinous acids are rare, their P-bonded coordination complexes are well established, e.g. Mo(CO)5P(OH)3.
Secondary and primary phosphine oxides
Tertiary phosphine oxides, compounds with the formula R3PO cannot tautomerize. The situation is different for the secondary and primary phosphine oxides, with the respective formulas R2(H)PO and R(H)2PO.
References
Functional groups
Organophosphorus compounds | Phosphinous acids | [
"Chemistry"
] | 369 | [
"Organophosphorus compounds",
"Organic compounds",
"Functional groups"
] |
62,256,831 | https://en.wikipedia.org/wiki/Hughes%E2%80%93Ingold%20symbol | A Hughes–Ingold symbol describes various details of the reaction mechanism and overall result of a chemical reaction. For example, an SN2 reaction is a substitution reaction ("S") by a nucleophilic process ("N") that is bimolecular ("2" molecular entities involved) in its rate-determining step. By contrast, an E2 reaction is an elimination reaction, an SE2 reaction involves electrophilic substitution, and an SN1 reaction is unimolecular. The system is named for British chemists Edward D. Hughes and Christopher Kelk Ingold.
References
Chemical reactions
Reaction mechanisms
Chemical nomenclature | Hughes–Ingold symbol | [
"Chemistry"
] | 134 | [
"Reaction mechanisms",
"nan",
"Physical organic chemistry",
"Chemical reaction stubs",
"Chemical kinetics"
] |
62,257,007 | https://en.wikipedia.org/wiki/Zinc%20azide | Zinc azide is an inorganic compound composed of zinc cations () and azide anions (). It is a white, explosive solid that can be prepared by the protonolysis of diethylzinc with hydrazoic acid:
Properties
Zinc azide is a coordination polymer which crystallizes in three polymorphs, all of which feature tetrahedral zinc centers and bridging azide ligands. α- crystallizes in the monoclinic space group and is stable, while the other two polymorphs are metastable. P21/n. β- is trigonal, space group P3221, and γ- is monoclinic, space group C2.
It is easily hydrolyzed, and attempts to prepare it in aqueous solution resulted in the precipitation of basic azides (x = 0.9–1.0). Both the α- and β-forms were found to be very friction- and shock-sensitive, violently exploding in blue flashes, but can be made to decompose slowly by gentle heating, giving off nitrogen gas. In a sealed glass tube with inert atmosphere, this yields zinc nitride, .
References
azide
zinc
Explosive chemicals | Zinc azide | [
"Chemistry"
] | 253 | [
"Explosive chemicals",
"Azides",
"Inorganic compounds",
"Inorganic compound stubs"
] |
62,257,146 | https://en.wikipedia.org/wiki/World%20Deserts%20Foundation | World Deserts Foundation (Fondation Deserts du Monde) is an Algerian non-governmental and intergovernmental organization. Its headquarters are located in Ghardaia, Algeria. Its mission is to promote sustainable development of desert regions.
World Deserts Foundation is one of the organizations participating on a continuing basis as the observer in the United Nations Economic and Social Council.
The Foundation has been established in 2002. It has created by the Algerian politician and then Minister of Tourism, Cherif Rahmani, as means to receive a share of funds from United Nations Development Programme allocated to the project overseen by the Algerian Ministry of Culture, as well as to provide a government-friendly, but officially independent and non-government partner for the purpose of securing funding that is not meant to be allocated to public institutions. For that reason, the Foundation has been criticized as a tool to misuse development funds and exclude proper civil society organizations who are less supportive of the government or have less ties to the current administration.
References.
2002 establishments in Algeria
Economic development organizations
Deserts | World Deserts Foundation | [
"Biology"
] | 207 | [
"Deserts",
"Ecosystems"
] |
62,258,052 | https://en.wikipedia.org/wiki/Itamar%20Medical | Itamar Medical is a multinational company focused on the development, manufacturing and sales of medical devices related to respiratory sleep disorders. The company is headquartered in Caesarea, Israel and is owned by ZOLL Medical Corporation. The company is a medical device company providing continuum of care in the area of sleep disorder based on its WatchPAT diagnostic devices and early diagnosis of Atherosclerosis.
Company overview
Itamar Medical was founded in 1995 as a developer of devices for assessing vascular defects. Its early products included technology for early detection of heart disease (EndoPAT) and detection of sleep disorders (WatchPAT).
The company is named after Itamar Yaron (one of the founders' brothers), who was killed in the Yom Kippur War when trying to rescue an injured soldier and was lawarded with a Medal of Courage. Itamar's headquarters is located in Caesarea, Israel, and the company has offices in the US, Japan, and the Netherlands.
In 2007, the company went public on the Tel Aviv Stock Exchange and on the Nasdaq. In 2011, the company made its first step on the Indian market.
In 2012, the company's WatchPAT started being distributed in Russia by Medical Diagnostic Methods.
In 2020, the company raised $40 million on the NASDAQ and won the SleepTech award for 2020.
In 2021, the company was acquired by ZOLL Medical Corporation and its stock delisted.
Company's devices
WatchPAT (FDA approval)
EndoPAT (FDA approval)
Sleep Apnea
References
External links
Companies based in Caesarea
Health care companies of Israel
Companies formerly listed on the Nasdaq
Companies listed on the Tel Aviv Stock Exchange
Israeli companies established in 1997
Sleep disorders
2021 mergers and acquisitions | Itamar Medical | [
"Biology"
] | 360 | [
"Behavior",
"Sleep",
"Sleep disorders"
] |
62,260,441 | https://en.wikipedia.org/wiki/PreonVM | PreonVM is an implementation of the Java virtual machine developed by Virtenio. The PreonVM was initially developed to run on the Atmel AVR ATmega256, but has been ported to ARM Cortex-M3 systems. Therefore the VM can run on a microcontroller with 8 kB RAM and 256 kB ROM at a minimum. The PreonVM requires no additional operating system and runs directly on the microcontroller.
Every class file of the application is transformed via a ClassLinker to strip all parts of class files that is not required. This makes it possible to reduce the class file size by about 80%, which is required for a small device. The ClassLinker builds a .vmm file which combines all application class files in a special format which can be read and executed by the PreonVM on the microcontroller.
The VM supports all Java data types incl. long and double, threads, synchronization, Garbage collection with memory defragmentation, exceptions, system properties and IRQ/event system. The PreonVM comes with a library of driver classes for IO like I2C, SPI, USART, CAN, PWM, IRQ, RTC, GPIO, ADC, DAC and with drivers for some sensors and IC's.
Code example
The following code examples uses an SHT21 sensor and reads the relative humidity.
public class SHT21Demo {
public static void main(String[] args) {
// sensor is connected to I2C bus instance 1
NativeI2C i2c = NativeI2C.getInstance(1);
i2c.open();
// create and init SHT21 sensor instance
SHT21 sht21 = new SHT21(i2c);
sht21.setResolution(SHT21.RESOLUTION_RH12_T14);
sht21.reset();
// read and print humidity every second
while (true) {
sht21.startRelativeHumidityConversion();
Thread.sleep(100);
int rawRH = sht21.getRelativeHumidityRaw();
float rh = SHT21.convertRawRHToRHw(rawRH);
System.out.println("SHT21: rawRH=" + rawRH + "; RH=" + rh);
Thread.sleep(900);
}
}
}
See also
List of Java virtual machines
External links
PreonVM site
Handbook of Industry 4.0 and SMART Systems - mentions the PreonVM as OS for WSN
Intelligent container - uses PreonVM operated radio module
Synchronous data acquisition with wireless sensor networks - mentions the PreonVM as option
Scalable Web Technology for the Internet of Things - mentions the PreonVM to run the CoAP framework
Java virtual machine | PreonVM | [
"Technology"
] | 624 | [
"Computing stubs",
"Software stubs"
] |
62,261,083 | https://en.wikipedia.org/wiki/Adam%20Babah-Alargi | Hajj Adam Babah-Alargi (25 December 1927 – 4 November 2019) was a Ghanaian engineer who was responsible for many national projects in Ghana. He was the first Ghanaian to establish Ghana's first indigenous engineering consultancy. He was a founding member of the Accra West branch of the Rotary Club.
Early life and education
Babah-Alargi was born on 25 December 1927 at Korle Gonno in Accra to Hausa parents. He studied structural engineering at Hammersmith College, London, England.
Career
Babah-Alargi joined Bolten Hennesy and Partners in 1958 after his college education. Around that period, the company had been charged with projects in Ghana and these projects were at the Kwame Nkrumah University of Science and Technology. Hajj was put in charge for some of these projects namely; The Vice Chancellor's Residence, the School of Architecture (Phases I and II), the Pharmacy Block and Halls of residence specifically Queen Elizabeth's Hall, which was commissioned by the Queen when she visited Ghana in 1961. In 1960 he joined OVE Aropp and Partners (then the biggest foreign consulting firm in Ghana) as a director. There, his first project was to oversee the erection of the Presidential stand at the Black Star Square, a project that needed to be ready prior to the Queen's visit. From 1961 to 1964 he worked on the Korle Bu Teaching Hospital as the only Ghanaian engineer in the team. The project saw the building of the Surgical, Maternity, and Children's wards among others. In 1965 the then president Dr. Kwame Nkrumah engaged him to restructure the presidential stand at the Black Star Square as the president thought it was too high. The president however, was unable to use the stand which was to be due in early 1966 as a result of the overthrow of his government in early 1966. In 1967 he founded his own consultancy firm by the name of BAB Consultancy. The firm was the first indigenous consultancy established by a Ghanaian in his field of expertise. It was therefore the first indigenous engineering consultancy founded in Ghana. He worked on many projects in the following years and also served as a consultant for the Bank of Ghana, the National Investment Bank, and Messrs SKOA. He retired in 1987 and the business was handed over to his staff.
He together with ten others founded the Rotary Club of Accra-West. In 1987, the late Michael Asafo-Boakye, the then District Governor, appointed him as the District Governor's special representative to help form the Rotary Club in Osu-RE.
Death
He died in November 2019 at the age of 91. His funeral was officiated by the National Chief Imam Sheikh Osmanu Nuhu Sharubutu. He was the oldest living rotarian in Ghana prior to his death.
References
1927 births
2019 deaths
20th-century Ghanaian engineers
Hausa people
Structural engineers | Adam Babah-Alargi | [
"Engineering"
] | 594 | [
"Structural engineering",
"Structural engineers"
] |
62,261,660 | https://en.wikipedia.org/wiki/World%20Flora%20Online | World Flora Online is an Internet-based compendium of the world's plant species.
Description
The World Flora Online (WFO) is an open-access database, launched in October 2012 as a follow-up project to The Plant List, with the aim of publishing an online flora of all known plants by 2020. It is a project of the United Nations Convention on Biological Diversity, with goal of halting the loss of plant species worldwide by 2020. It is developed by a collaborative group of institutions around the world in response to the 2011–2020 Global Strategy for Plant Conservation (GSPC)'s updated Target 1: to produce "an online flora of all known plants".
An accessible flora of all known plant species was considered a fundamental requirement for plant conservation. It provides a baseline for the achievement and monitoring of other targets of the strategy. The previous target of GSPC was achieved in 2010 with The Plant List. WFO was conceived in 2012 by an initial group of four institutions; the Missouri Botanical Garden, the New York Botanical Garden, the Royal Botanic Garden Edinburgh and the Royal Botanic Gardens, Kew. In all, 36 institutions are involved in the production.
See also
International Plant Names Index
Plants of the World Online
References
Bibliography
, see also The Plant List
.
Databases in the United Kingdom
Databases in the United States
Missouri Botanical Garden
Online botany databases
Online taxonomy databases
Plant taxonomy
Royal Botanic Gardens, Kew | World Flora Online | [
"Biology"
] | 285 | [
"Botanical nomenclature",
"Plants",
"Botanical terminology",
"Biological nomenclature",
"Plant taxonomy"
] |
62,262,255 | https://en.wikipedia.org/wiki/Jack%20D.%20Keene | Jack D. Keene (born June 22, 1947, Jacksonville, Florida) is a James B. Duke Professor of Molecular Genetics and Microbiology at Duke University.
Keene studies the regulation of RNA and the mechanisms of RNA-protein interactions. He identified RNA recognition motif (RRM) proteins, which are the largest family of RNA-binding proteins. He isolated the first human autoimmune antigen. He formalized the posttranscriptional operon and regulon (PTRO) model to describe global gene regulation, and proposed the RNA regulon hypothesis to better understand post-transcriptional regulation of mRNAs encoding proteins. Keene introduced the RIP (ribonucleoprotein immunoprecipitation) protocol for isolating specific mRNPs, which has become a tool for the mapping of mRNA targets of specific RBPs.
Early life and education
Jack Donald Keene was born in Jacksonville, Florida on June 22, 1947. His father worked for the RAND Corporation. Keene attended Redlands High School in Redlands, California, graduating in 1965.
Initially a student at University of California, Los Angeles (UCLA),
he transferred to the University of California, Riverside, where he majored in biology, working with Carlton Bovell. He received his A.B. degree in 1969.
Next, Keene studied with Helen Riaboff Whiteley at the University of Washington in Seattle, Washington, graduating in 1975 with a doctorate in microbiology and Immunology.
He did postdoctoral work in molecular virology with Robert A. Lazzarini in the Laboratory for Molecular Genetics at the National Institutes of Health in Bethesda, Maryland from 1974 to 1978.
Career
In 1979, Keene was recruited by Wolfgang Joklik to the department of microbiology and immunology at Duke University Medical Center. At that time the department was ranked one of the top three in the United States by the National Research Council.
Keene was the chairman of the department of microbiology from 1992 to 2002, and
director of basic sciences for the Duke Comprehensive Cancer Center from 1995 to 2003.
As of 1997 he became the James B. Duke Professor of Molecular Genetics and Microbiology at Duke University.
In 1999 Keene founded the Duke Center for RNA Biology.
Research
Keene studies the regulation of RNA and the mechanisms of RNA-protein interactions.
In his work on molecular genetics, he and his coworkers have examined the role of DNA and RNA-binding proteins (RBPs) in the pathogenesis of autoimmunity.
In the late 1970s and early 1980s he identified genomic sequences for vesicular stomatitis virus (VSV) and rabies virus (RABV), members of the Rhabdoviridae family of viruses,
and for Ebola virus and Marburg virus from the broader group of negative-strand RNA viruses (NSRV).
He identified the origins of defective interfering particles of negative-strand RNA viruses.
Through combinatorial studies of viral and bacterial systems, he has identified targets for novel pharmacological studies.
Later in the 1980s, Keene identified RNA recognition motif (RRM) proteins. RRM proteins are the largest family of RNA-binding proteins and the seventh largest protein family of the human genome. RRM is a prevalent RNA-binding fold involving proteins implicated in RNA biogenesis, processing, transport, and degradation.
In 1987, Query and Keene first identified a B-cell epitope within the U1-70K protein.
Keene isolated the first human autoimmune antigen and elucidated its autoimmune epitopes, the parts of an antigen to which antibodies in the immune system can bind.
He cloned rheumatological autoimmune protein genes. He developed a diagnostic test for systemic lupus erythematosus using recombinant antigens.
Keene's lab has identified functions of the ELAV/Hu posttranscriptional regulators HuB, HuC and HuD and their roles and that of HuR in processes of growth, proliferation, differentiation, and immune response.
The study of RNA-binding proteins such as HuR and the determination of the binding of specific sequences have informed Keene's later post-transcription theory and his coordination theory of RNA operons.
RNA-binding proteins appear to be implicated in the functioning of many posttranscriptional processes. As of 1994, Keene suggested that RNA-binding proteins could be involved in the regulation of messenger RNA that encode cytokines.
In 2000, he was able to apply this approach to demonstrate neuronal differentiation. He also introduced the first use of the RIP (ribonucleoprotein immunoprecipitation) protocol, isolating specific mRNPs using immunoprecipitation, and identifying the mRNA component with microarray or deep sequencing. This method has become a tool for the mapping of mRNA targets of specific RBPs.
In 2001–2002, Keene formalized the posttranscriptional operon and regulon (PTRO) model for global gene regulation.
By 2007, Keene proposed the RNA regulon hypothesis, "that mRNAs encoded by functionally related genes may be coordinately regulated as posttranscriptional RNA regulons by specific mRNP processing machineries".
The purpose of the RNA regulon model was to better understand post-transcriptional regulation, to answer the question "How does the cell coordinate metabolism and regulation of mRNAs encoding proteins in the same biological process so that the proteins can be coordinately produced?"
Awards and honors
1985, Pew Scholar in the Biomedical Sciences, The Pew Charitable Trusts.
2009, Fellow, American Academy of Microbiology
2009, James Buchanan Duke Distinguished Professorship, Duke University.
2009, Member, American Academy of Microbiology
References
1947 births
Living people
American molecular biologists
Molecular geneticists
American chemists
Scientists from Jacksonville, Florida
People from Redlands, California
University of California, Riverside alumni
University of Washington alumni
Duke University faculty | Jack D. Keene | [
"Biology"
] | 1,236 | [
"Molecular geneticists",
"Molecular genetics"
] |
62,262,369 | https://en.wikipedia.org/wiki/Topo%20Chico | Topo-Chico is a brand of sparkling mineral water from Mexico. Topo-Chico is both naturally carbonated at the source and artificially carbonated.
History
Topo-Chico has been sourced from and bottled in Monterrey, Mexico since 1895. The drink takes its name from the mountain Cerro del Topo Chico in Monterrey.
In 2017, The Coca-Cola Company purchased Topo-Chico for $220 million. The brand was originally popular in northern Mexico and Texas, with the Coca-Cola Company later helping popularize it across the United States. The drink has a cult following.
Ranch water is a cocktail made with tequila, lime juice and Topo-Chico, over ice, a popular drink in Texas. A similar drink, the Chilton, substitutes the lime for a lemon, the tequila for vodka, and adds salt on the rim. The drink allegedly derives its name from a doctor in Lubbock.
Topo-Chico Hard Seltzer
In 2021, the Coca-Cola Co used its sparkling mineral water brand Topo-Chico to launch a range of vegan friendly alcoholic hard seltzers in the United Kingdom and in the United States with Molson Coors. The range includes Tangy Lemon Lime, Tropical Mango and Cherry Acai flavors in the United Kingdom and flavors such as Tangy Lemon Lime, Tropical Mango, Strawberry Guava and Exotic Pineapple in the US.
In early 2022, Topo Chico ranch water launched their new Hard Seltzer Topo Chico Ranch Water in select markets, along with the national rollout of its variety pack. The product is now available in stores across Alabama, Arizona, California, Colorado, Georgia, New Mexico, Oklahoma, Tennessee, and Texas.
Neither Topo Chico Hard Seltzer nor Topo Chico Ranch Water are made with mineral water from the original Topo Chico spring. Rather, they are “inspired by the taste” of the original drink.
Legal issues
In 2023, a New York resident sued Coca-Cola because its Topo Chico Margarita Hard Seltzers do not contain tequila and cited that the product's packaging was misleading about the contents of the beverage. The lawsuit was dismissed later that year. In 2024, a Florida resident brought a similar suit against Coca-Cola, also citing that the product's packaging includes "false and misleading representations and omissions" suggesting that the product contains tequila.
In popular culture
"Topo Chico" is the subject and title of the last song on Robert Ellis's 2019 album Texas Piano Man.
Topo Chico is featured on the album cover of Seattle WA band iji's 2013 album UNLTD. COOL DRINKS.
See also
List of bottled water brands
List of Coca-Cola brands
References
Further reading
External links
Topo Chico Water Analysis Report
Coca-Cola brands
Mexican brands
Mineral water
Monterrey | Topo Chico | [
"Chemistry"
] | 572 | [
"Mineral water"
] |
62,262,830 | https://en.wikipedia.org/wiki/Undercut%20%28turning%29 | In turning, an undercut is a recess in a diameter generally on the inside diameter of the part.
On turned parts an undercut is also known as a neck or "relief groove". They are often used at the end of the threaded portion of a shaft or screw to provide clearance for the cutting tool, and also referred to as thread relief in this context. A rule of thumb is that the undercut should be at least 1.5 threads long and the diameter should be at least smaller than the minor diameter of the thread. Strictly speaking the relief simply needs to be equal or slightly smaller than the minor diameter of the thread. Thread relief can also be internal on a bore, and then the relief needs to be larger than the major thread diameter. They are also often used on shafts that have diameter changes so that a mating part can seat against the shoulder. If an undercut is not provided there is always a small radius left behind even if a sharp corner is intended. These types of undercuts are called out on technical drawings by saying the width and either the depth or the diameter of the bottom of the neck.
References
Bibliography
.
Mechanical engineering | Undercut (turning) | [
"Physics",
"Engineering"
] | 234 | [
"Applied and interdisciplinary physics",
"Mechanical engineering"
] |
76,174,134 | https://en.wikipedia.org/wiki/Leucocoprinus%20attinorum | Leucocoprinus attinorum is a species of mushroom-producing fungus in the family Agaricaceae.
Taxonomy
It was described in 2023 by the mycologists Salomé Urrea‑Valencia, Rodolfo Bizarria Júnior, Pepijn W. Kooij, Quimi Vidaurre Montoya and Andre Rodrigues who conducted a study on fungal species cultivated by lower attine ants which described the new species Leucocoprinus attinorum and L. dunensis.
Description
Leucocoprinus attinorum is a fungus cultivated by Mycocepurus goeldii ants.
Cap: 3-4cm wide, starting campanulate before expanding to applanate with age. The surface is coated in small brown scales with a darker brown centre disc. Gills: Free with a collar, crowded and whitish. Stem: 2.5-8cm long and 4-8mm thick with a slightly bulbous base but otherwise generally consistent thickness across the length and solid inner flesh. The surface light brown and is coated in fine fibrils but turns dark brown when bruised or touched. The movable stem ring is white with a dark brown margin of a similar colour to the cap centre. Spore print: Pale white. Spores: 7-8 x 5-6 (6.5) μm. Ellipsoid to amygdaliform with a rounded apex and germ pore covered with a hyaline cap. Smooth, thick walled and hyaline with no colour change in KOH. Congophilous, dextrinoid, metachromatic in cresyl blue. Basidia: 22-30 x 10-11 μm. Clavate, 4-spored, hyaline.
Etymology
The specific epithet attinorum is named in reference to the subtribe Attina to which the Mycocepurus goeldii ants belong.
Habitat and distribution
The species is cultivated by the fungus farming ant species Mycocepurus goeldii, the geographical range of which includes Brazil, parts of Bolivia, Paraguay and Northern Argentina. so this fungus may possibly extend over this same range.
References
Fungi described in 2023
Fungus species
Leucocoprinus | Leucocoprinus attinorum | [
"Biology"
] | 458 | [
"Fungi",
"Fungus species"
] |
76,174,243 | https://en.wikipedia.org/wiki/Leucocoprinus%20dunensis | Leucocoprinus dunensis is a species of mushroom-producing fungus in the family Agaricaceae.
Taxonomy
It was described in 2023 by the mycologists Salomé Urrea‑Valencia, Rodolfo Bizarria Júnior, Pepijn W. Kooij, Quimi Vidaurre Montoya and Andre Rodrigues who conducted a study on fungal species cultivated by lower attine ants which described the new species Leucocoprinus dunensis and L. attinorum.
Description
Leucocoprinus dunensis is a fungus cultivated by Mycetophylax morschi ants.
Cap: 3.5-4cm wide, starting campanulate before expanding to applanate with age. The surface is covered with small light brown scales towards the margin with a solid brown centre disc. The margins are sometimes striated. Gills: Free with a collar, crowded and whitish with a fimbriate edge. Stem: 3-7cm long and 2-5mm thick without a significantly bulbous base. The surface is brownish orange and covered in fine fibrils. The ascendant stem ring is white and is located towards the top of the stem (superior). Spore print: Pale white. Spores: 7-8 (9) x 5-6 μm. Amygdaliform in side view and ellipsoidal in front view. Smooth, thick walled with an inconspicuous germ pore. Hyaline with no colour change in KOH. Congophilous, dextrinoid, metachromatic in cresyl blue. Basidia: 20-22 x 10 μm. Clavate, 2 to 4-spored, hyaline.
Etymology
The specific epithet dunensis is named in reference to the dune ecosystem in which Mycetophylax morschi lives.
Habitat and distribution
The species is cultivated by the fungus farming ant species Mycetophylax morschi, which is found in the sandy restinga forests of Brazil.
References
Fungi described in 2023
Fungus species
Leucocoprinus | Leucocoprinus dunensis | [
"Biology"
] | 430 | [
"Fungi",
"Fungus species"
] |
76,174,498 | https://en.wikipedia.org/wiki/Bosch-Meiser%20process | The Bosch–Meiser process is an industrial process, which was patented in 1922 and named after its discoverers, the German chemists Carl Bosch and Wilhelm Meiser for the large-scale manufacturing of urea, a valuable nitrogenous chemical.
The whole process consists of two main equilibrium reactions, with incomplete conversion of the reactants.
The first, called carbamate formation: the fast exothermic reaction of liquid ammonia with gaseous carbon dioxide () at high temperature and pressure to form ammonium carbamate ():
(ΔH = −117 kJ/mol at 110 atm and 160 °C)
The second, called urea conversion: the slower endothermic decomposition of ammonium carbamate into urea and water:
(ΔH = +15.5 kJ/mol at 160–180 °C)
The overall conversion of and to urea is exothermic, with the reaction heat from the first reaction driving the second. The conditions that favor urea formation (high temperature) have an unfavorable effect on the carbamate formation equilibrium. The process conditions are a compromise: the ill-effect on the first reaction of the high temperature (around 190 °C) needed for the second is compensated for by conducting the process under high pressure (140–175 bar), which favors the first reaction. Although it is necessary to compress gaseous carbon dioxide to this pressure, the ammonia is available from the ammonia production plant in liquid form, which can be pumped into the system much more economically. To allow the slow urea formation reaction time to reach equilibrium, a large reaction space is needed, so the synthesis reactor in a large urea plant tends to be a massive pressure vessel.
Reactant recycling
Because the urea conversion is incomplete, the urea must be separated from the unconverted reactants, including the ammonium carbamate. Various commercial urea processes are characterized by the conditions under which urea forms and the way that unconverted reactants are further processed.
Conventional recycle processes
In early "straight-through" urea plants, reactant recovery (the first step in "recycling") was done by letting down the system pressure to atmospheric to let the carbamate decompose back to ammonia and carbon dioxide. Originally, because it was not economic to recompress the ammonia and carbon dioxide for recycle, the ammonia at least would be used for the manufacture of other products such as ammonium nitrate or ammonium sulfate, and the carbon dioxide was usually wasted. Later process schemes made recycling unused ammonia and carbon dioxide practical. This was accomplished by the "total recycle process", developed in the 1940s to 1960s and now called the "conventional recycle process". It proceeds by depressurizing the reaction solution in stages (first to 18–25 bar and then to 2–5 bar) and passing it at each stage through a steam-heated carbamate decomposer, then recombining the resulting carbon dioxide and ammonia in a falling-film carbamate condenser and pumping the carbamate solution back into the urea reaction vessel.
Stripping recycle process
The "conventional recycle process" for recovering and reusing the reactants has largely been supplanted by a stripping process, developed in the early 1960s by Stamicarbon in The Netherlands, that operates at or near the full pressure of the reaction vessel. It reduces the complexity of the multi-stage recycle scheme, and it reduces the amount of water recycled in the carbamate solution, which has an adverse effect on the equilibrium in the urea conversion reaction and thus on overall plant efficiency. Effectively all new urea plants use the stripper, and many total recycle urea plants have converted to a stripping process.
In the conventional recycle processes, carbamate decomposition is promoted by reducing the overall pressure, which reduces the partial pressure of both ammonia and carbon dioxide, allowing these gasses to be separated from the urea product solution. The stripping process achieves a similar effect without lowering the overall pressure, by suppressing the partial pressure of just one of the reactants in order to promote carbamate decomposition. Instead of feeding carbon dioxide gas directly to the urea synthesis reactor with the ammonia, as in the conventional process, the stripping process first routes the carbon dioxide through the stripper. The stripper is a carbamate decomposer that provides a large amount of gas-liquid contact. This flushes out free ammonia, reducing its partial pressure over the liquid surface and carrying it directly to a carbamate condenser (also under full system pressure). From there, reconstituted ammonium carbamate liquor is passed to the urea production reactor. That eliminates the medium-pressure stage of the conventional recycle process.
Side reactions
The three main side reactions that produce impurities have in common that they decompose urea.
Urea hydrolyzes back to ammonium carbamate in the hottest stages of the synthesis plant, especially in the stripper, so residence times in these stages are designed to be short.
Biuret is formed when two molecules of urea combine with the loss of a molecule of ammonia.
Normally this reaction is suppressed in the synthesis reactor by maintaining an excess of ammonia, but after the stripper, it occurs until the temperature is reduced. Biuret is undesirable in urea fertilizer because it is toxic to crop plants to varying degrees, but it is sometimes desirable as a nitrogen source when used in animal feed.
Isocyanic acid HNCO and ammonia results from the thermal decomposition of ammonium cyanate , which is in chemical equilibrium with urea:
This decomposition is at its worst when the urea solution is heated at low pressure, which happens when the solution is concentrated for prilling or granulation (see below). The reaction products mostly volatilize into the overhead vapours, and recombine when these condense to form urea again, which contaminates the process condensate.
Corrosion
Ammonium carbamate solutions are highly corrosive to metallic construction materials – even to resistant forms of stainless steel – especially in the hottest parts of the synthesis plant such as the stripper. Historically corrosion has been minimized (although not eliminated) by continuous injection of a small amount of oxygen (as air) into the plant to establish and maintain a passive oxide layer on exposed stainless steel surfaces. Highly corrosion resistant materials have been introduced to reduce the need for passivation oxygen, such as specialized duplex stainless steels in the 1990s, and zirconium or zirconium-clad titanium tubing in the 2000s.
Global production
In 2022, the world production of urea was estimated approximately at 210 million tons.
References
Fertilizers
Chemical processes
Industrial processes
Equilibrium chemistry
Catalysis
German inventions | Bosch-Meiser process | [
"Chemistry"
] | 1,417 | [
"Catalysis",
"Fertilizers",
"Equilibrium chemistry",
"Organic compounds",
"Chemical processes",
"Soil chemistry",
"nan",
"Chemical process engineering",
"Chemical kinetics",
"Ureas"
] |
76,174,803 | https://en.wikipedia.org/wiki/Doctory | Doctory or daktari is a referral term for practising modern medicine arising in the Indian subcontinent during colonialism. The concept, has been framed by historical sociologist Neshat Quaiser and is now part of the social history of South Asian medicine & health and colonial studies.
Concept
In the Indian subcontinent, modern medicine—which became closely associated with colonialism—was referred to as "doctory" or daktari ilaj. The doctor and doctory ilaaj emerged as powerful symbols of colonialism and the colonial state. The doctor was one of the most visible representatives of European knowledge. He looked, dressed and spoke differently. He was certainly not equivalent to the Hakim. The doctor with his stethoscope created an aura and mystery around himself. He symbolised 'modern medicine'. In fact, being visited by a doctor became a symbol of high status and modernity.
It is a label for the practice of indigenous medicine in South Asia. In social history of South-Asian medicine, this concept has been in discussion.
According to Nandani Bhattacharya, the term 'doctory' has a deep political resonance.
Emergence
During the period British rule in India(1700s to 1900s), western medicine had begun to take over and was spreading with time. The administration hired many Indians as "native doctors" in the inferior medical service, which had been primarily made up of Europeans, after they had training in Western medicine. Most of the colonial government's support for indigenous medical systems was progressively withdrawn. The assertions made by Western medicine was that it is a more logical and “superior” medical system caused the practitioners of these systems, the 'vaidyas' and 'hakims', to lose a great deal of their status. While some of them turned into purists and defended and promoted their systems, others incorporated Western medical concepts and practices into their training and clinical work.
Initially, the loose adoption of this Western medical practice, looks and behaviour came out as a 'doctory'. Later, it changed into a bigger spectrum and was given symbolic meaning.
See also
Unani medicine
History of medicine
References
External links
Projit Bihari Mukharji, who has extended the Quaiser's concept in his discussion of Medical market.
History of South Asia
History of medicine
Sociology | Doctory | [
"Biology"
] | 475 | [
"Behavioural sciences",
"Behavior",
"Sociology"
] |
76,176,354 | https://en.wikipedia.org/wiki/List%20of%20British%20regions%20by%20life%20expectancy |
Office for National Statistics (2017-19, 2020-22)
By default the table is sorted by arithmetic mean for 2017-2019.
Data source: Office for National Statistics. Data for Scotland for 2022-22 are taken from adjacent table of the same agency.
Eurostat (2017, 2018)
By default the table is sorted by 2018.
Data source: Eurostat
Global Data Lab (2019–2022)
Data source: Global Data Lab
Charts
See also
References
Health in the United Kingdom
Demographics of the United Kingdom
United Kingdom, life expectancy
United Kingdom
United Kingdom health-related lists | List of British regions by life expectancy | [
"Biology"
] | 119 | [
"Senescence",
"Life expectancy"
] |
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