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Windows 11 is the latest major release of the Windows NT operating system and the successor of Windows 10 . Some features of the operating system were removed in comparison to Windows 10, and further changes in older features have occurred within subsequent feature updates to Windows 11. Following is a list of these.
The following applications are no longer bundled with Windows 11 and no longer available. [ 1 ]
The following applications are no longer bundled with Windows 11, but can still be installed from the Microsoft Store . [ 1 ]
The following parts of the Windows shell are no longer available in Windows 11.
In addition:
Some functionality from the Start menu was removed and replaced with other features.
The following taskbar features are no longer available as of Windows 11:
Windows 11 is only available for the x86-64 and ARM64 CPU architectures, as Microsoft is no longer offering a Windows build for IA-32 x86 and ARMv7 systems. [ 1 ] Additionally, NTVDM and the 16-bit Windows on Windows subsystems, which allowed 32-bit versions of Windows to directly run 16-bit DOS and Windows programs, are no longer included with Windows 11.
User-mode scheduling (UMS), available on x64 versions Windows 7 and later, was a lightweight mechanism allowing applications to schedule their own threads, without involvement from the system scheduler. This feature is not included with Windows 11. [ 16 ]
The default Windows 10 and Flowers themes have been removed. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_11 |
While Windows 7 contains many new features , a number of capabilities and certain programs that were a part of previous Windows versions up to Windows Vista were removed or changed.
The following is a list of features that were present in Windows Vista and earlier versions but were removed in Windows 7. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_7 |
Windows 8 is a version of Windows NT and the successor of Windows 7 . Several features that originated in earlier versions of Windows and that were included in versions up to Windows 7 are no longer present in Windows 8. Following is a list of these. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_8 |
While Windows Phone contains many new features, a number of capabilities and certain programs that were a part of previous versions up to Windows Mobile 6.5 were removed or changed. [ 1 ] [ 2 ] Until Windows Mobile 6.5, the previous version did always cover the complete feature range of the predecessor version.
The following is a list of features which were present in Windows Mobile 6.5 but were removed in Windows Phone 7.0. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_Phone |
While Windows Vista contains many new features , a number of capabilities and certain programs that were a part of previous Windows versions up to Windows XP were removed or changed – some of which were later re-introduced in Windows 7 and later versions.
The following is a list of features that were present in Windows XP and earlier versions but were removed in Windows Vista. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_Vista |
As the next version of Windows NT after Windows 2000 , as well as the successor to Windows Me , Windows XP introduced many new features but it also removed some others. Following is a list of these. | https://en.wikipedia.org/wiki/List_of_features_removed_in_Windows_XP |
Feeding is the process by which organisms, typically animals , obtain food . Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin vorare , meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγεῖν ( phagein ), meaning "to eat".
The evolution of feeding is varied with some feeding strategies evolving several times in independent lineages. In terrestrial vertebrates, the earliest forms were large amphibious piscivores 400 million years ago. While amphibians continued to feed on fish and later insects, reptiles began exploring two new food types, other tetrapods (carnivory), and later, plants (herbivory). Carnivory was a natural transition from insectivory for medium and large tetrapods, requiring minimal adaptation (in contrast, a complex set of adaptations was necessary for feeding on highly fibrous plant materials). [ 1 ]
The specialization of organisms towards specific food sources is one of the major causes of evolution of form and function, such as:
There are many modes of feeding that animals exhibit, including:
Polyphagy is the habit in an animal species, of eating and tolerating a relatively wide variety of foods, whereas monophagy is the intolerance of every food except for one specific type (see generalist and specialist species ). Oligophagy is a term for intermediate degrees of selectivity, referring to animals that eat a relatively small range of foods, either because of preference or necessity. [ 2 ]
Another classification refers to the specific food animals specialize in eating, such as:
The eating of non-living or decaying matter:
There are also several unusual feeding behaviours, either normal, opportunistic , or pathological, such as:
An opportunistic feeder sustains itself from a number of different food sources, because the species is behaviourally sufficiently flexible.
Some animals exhibit hoarding and caching behaviours in which they store or hide food for later use. | https://en.wikipedia.org/wiki/List_of_feeding_behaviours |
This is a list of fentanyl analogues (sometimes referred to as Fentalogs ), [ 1 ] [ 2 ] [ 3 ] including both compounds developed by pharmaceutical companies for legitimate medical use, and those which have been sold as designer drugs and reported to national drug control agencies such as the DEA , or transnational agencies such as the EMCDDA and UNODC . [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] This is not a comprehensive listing of fentanyl analogues, as more than 1400 compounds from this family have been described in the scientific and patent literature, [ 11 ] [ 12 ] [ 13 ] [ 14 ] [ 15 ] but it includes many notable compounds that have reached late-stage human clinical trials, or which have been identified as having been sold as designer drugs, as well as representative examples of significant structural variations reported in the scientific and patent literature. The structural variations among fentanyl-related substances can impart profound pharmacological differences between these drugs, especially with respect to potency and efficacy. [ 16 ] [ 17 ] [ 18 ] [ 19 ] [ 20 ]
In the United States, the Drug Enforcement Administration placed the broadly defined class of "Fentanyl-Related Substances" on the list of Schedule I drugs in 2018, making it illegal to manufacture, distribute, or possess fentanyl analogs. [ 21 ] Temporary control of fentanyl-related substances in Schedule I was extended through December 31, 2024 by Public Law 117-328. [ 22 ]
[ 31 ] [ 32 ]
Several jurisdictions have implemented analogue law controls of fentanyl analogues in an attempt to pre-emptively ban novel derivatives before they appear on the market. One representative example is the New Zealand provisions enacted in 1988 in response to the first wave of fentanyl derivatives. This bans a set of structures as follows;
"Fentanyl analogues, in which the N-[1-(2-phenethyl)-4-piperidyl]aniline nucleus has additional radicals, either alone or in combination, attached as follows:
(a) an acetyl, propionyl, butenoyl or butanoyl radical, attached to the aniline nitrogen atom:
(b) 1 or more alkyl radicals, with up to 10 carbon atoms in total, attached to the ethyl moiety:
(c) any combination of up to 5 alkyl radicals and/or alkoxy radicals (each with up to 6 carbon atoms, including cyclic radicals) and/or halogen radicals, attached to each of the benzene rings." [ 51 ]
A more recent and somewhat broader example was introduced into US Federal legislation in 2018, [ 52 ] covering the following structures;
"...fentanyl-related substances includes any substance not otherwise controlled in any schedule...that is structurally related to fentanyl by one or more of the following modifications:
Because there are so many analogues of fentanyl, the naming for them tends to follow classical or IUPAC nomenclature conventions. This section is written to help illustrate the basic ring structure of fentanyl and what popular analogues reference on the carbon skeleton, helping a chemist working with fentanyl analogues quickly and consistently navigate the nomenclature system.
The synthesis of fentanyl and its analogues are illustrated in these skeletal diagrams. The synthesis of fentalogs is done by reacting the ring structure as a base, 4-ANPP also called 4-anilino-N-phenethylpiperidine and despropionylfentanyl. 4-ANPP acts as a base because of its two amine nitrogens, the secondary amine acts as a base to react with an organic acid which condenses into an amide. Depending on the organic acid used in the amide condensation, different analogues of fentanyl will be produced. To help align this phenomenon in the eyes of chemists, we have numerated the precursor 4-ANPP with a [0.], and then the reactions synthesizing fentanyl, acetylfentanyl, butyrylfentanyl, and benzoylfentanyl with a [1.], [2.], [3.], and [4.] respectively. To further aid in the chemical pedagogy we have aligned each number with a reaction number -> precursor -> product system that follows the following scheme:
EXAMPLE: reaction number -> precursor -> product [compound name] 1 -> α -> a [fentanyl] 2 -> β -> b [acetylfentanyl] 3 -> γ -> c [butyrylfentanyl] 4 -> δ -> d [benzoylfentanyl]
Using the above scheme, a chemist can quickly extrapolate the reactions necessary for other fentanyl analogues with more complex organic acids, such as cyclopropryl fentanyl or cyclopentyl fentanyl, or any other fentanyl analogue derived from a reaction of 4-ANPP with a novel organic acid.
The modifications covered in this diagram have to do with carbon skeleton modifications of the original fentanyl molecular structure.
These are organized into methyl acetate additions, which are most known for the fentanyl -> carfentanil conversion. Many analogues of great potency, such as ohmfentanyl and lofentanyl possess methyl acetate groups added to the 4-carbon (of the piperidine ring, in the para- position relative to the annular nitrogen). The methyl acetate is added here from the α-carbon of the acetate moiety as it is with ohm- and lofentanyl. The 4-carbon is not a chiral center in carfetnanil because of a lack of piperidinyl substituents, but this same carbon is a chiral center in both ohm- and lofentanyl because both of those analogues have piperidinyl substituents.
The second group are organized into methyl additions, which are known for the fentanyl analogues such as α-methylfentanyl and cis-3-methylfentanyl. These analogues can possess a wide variety of modified pharmacological properties, including increased and decreased potency (receptor binding efficiency), increased or decreased half-life (metabolic binding efficiency) or other side effects on human physiology. Other substituents such as hydroxy, chloro, fluoro, and a wide variety of alkyl groups, are also substituted in place of these methylations to produce psychoactive analogues of fentanyl, but because they often use the same skeletal naming conventions as the simple methyl analogues, we did not reproduce them all in the image here.
The modifications described here cover alterations to the ring structure donated by the fentanyl precursor 4-ANPP. Although another series covered substitutions of hydrogen atoms on the original carbon ring structure, sometimes called functional group additions, this series focuses on the three main modifications to the phenethyl moiety. The first modifications is the removal of the phenthyl moeity from the piperidinyl nitrogen, depicted here as hydrolysis yielding phenethanol. This changes the parent skeletal name to norfentanyl.
The second and third modifications are the removal and addition of a methylene moiety internally in the ethyl chain within the greater phenethyl moiety. The removal of a methylene, which shortens the chain by one carbon length, creates the benzylfentanyl structure. The addition of a methylene, which lengthens the chain by one length, creates homofentanyl.
The modifications covered in this diagram have to do with stereochemistry and the assignment of unique Cahn-Ingold-Prelog R/S assignments to complex analogues of fentanyl.
The stereochemistry of fentanyl analgoues can seem at first counter-intuitive, because of the complex and unique nature of the reasoning organic chemists must develop to internalize complex three dimensional geometries such as those needed to comprehend stereochemistry. Thankfully these images follow a simple procedure for organizing a potential analogue of fentanyl into the total number of unique stereoisomers, the number of true stereocenters on the molecule, and the number of Cahn-Ingold-Prelog R/S assignments that are appropriate for that analogue.
The procedure used in the analysis of stereochemistry in these series of images is the following:
This procedure will be used when making an assessment of the number of valid stereoisomers that an analogue of fentanyl will be predicted to have. Because the analogues of fentanyl are so large, and the moieities (sub-regions) of the molecule that are relevant to its chirality are so small, that we often reproduce the fentanyl analogue as a smaller, simpler molecule with the same number of, and dynamics between its, stereocenters. This saves significant space allowing us not to reproduce redundant material that consumes a lot of space on the image.
The first case studied here is fentanyl itself, or propionyl-4-anilino-N-phenethylpiperidine, the most well known of the fentanyl analogues and the eponymous molecule (namesake) for the whole chemical categorey. The only identified stereocenter is found at the 4-carbon, opposite the piperidine nitrogen but adjacent to the aniline nitrogen. This seems to be a stereocenter because of the apparent 4 unique substituents. We transfer this stereocenter to the equivalent molecule cyclohexanol, with an analogous apparent stereocenter. Once we draw out the potential stereoisomers, we see that the two structures are super-imposable in three dimensions, and therefore are the self-same molecule. For this reason fentanyl does not have R/S assignments.
The second case studied here is of 3-methylfentanyl. There are two potential stereocenters, at the 4-carbon and also at the 3-carbon, where there is additionally a methyl group. Now, we mark both 3 and 4 carbon as potential stereocenters with an asterisk (*), and see how many potential stereoisomers we can eliminate. We see that of the four permutations of stereoisomers, none are super-imposable in three dimensions, meaning each is a unique stereoisomer and that both potential stereocenters were true. This gives 4 potential R/S assignments, 1R3S, 1R3R, 1S3S, 1S3R. What is particularly interesting and quite a contrast from the previous example of cyclohexanol, is the stereocenter at C-4 is indeed a true stereocenter here, whereas in the previous example of cyclohexanol as an analogy to fentanyl, the C-4 was not a true stereocenter. This changed because the modification of the C-3 carbon without an equivalent change on the C-2 carbon created an imbalance between two formerly identical substituents, creating a novel stereocenter where there was not one previously. This is why it is so important to follow the 4 steps in the above procedure every time, as "inherited procedural wisdom" may hold an organic chemist back in finding the true or correct answer.
The third case studied here is alpha-methylfentanyl. This group contains a substitution similar to the 3-methylfentanyl that was examined in the previous example on the previous image in this series (Fentanyl Synthesis p4.png), but it is on the phenethyl chain as opposed to being implanted on the piperidine ring. We then mark the two stereocenters, one on the C-4 carbon just as on fentanyl itself, and the other on the C-α (alpha carbon). To analogize these stereocenters we chose N-(1-hydroxyethyl)-4-hydroxypiperidine. When we draw out all potential stereoisomers, we see that the C-4 stereocenter is super-imposable, eliminating it as a true stereocenter. This leaves only 2 R/S assignments that follow the orientation of the stereocenter at the C-α (alpha carbon) position for the real α-methylfentanyl. These are labeled 7S and 7R, a reflection of the stereocenter in the piperidine derivative we used being at C-7 position. It is interesting that the C-4 stereocenter, which has no chiral activity in fentanyl (1st example), activiates it in 3-methylfentanyl with an on-the-ring addition, and loses it again in α-methylfentanyl with an off-the-ring addition.
The fourth case studied here is ohmfentanyl. Ohmfentanyl has 3 potential stereocenters, which are best analogized by another piperidine derivative: N-(1-hydroxyethyl)-3-methyl-4-hydroxypiperidine. This uses a similar structure to analogize the three potential stereocenters in ohmfentanyl, namely the 4-C, the 3-C, and the β-C (beta carbon). These three stereocenters are analogized in the C-4, C-3, and C-7 respectively. When we draw all potential stereoisomers out we see that they are not super-imposable in any combination of pairing, and therefore we have 8 unique stereoisomers and 3 true stereocenters. This yields 8 unique R/S assignment combinations which are outlined as captions under the stereoisomers of the analogous molecule.
These fundamentals are typically enough to help a chemists navigate the world of fentanyl analogues proficiently. Other substituents and substitutions generally follow the naming conventions outlined in this section. However, the presence of three six-membered rings which can each be independently substituted can easily lead to confusion, especially with the inconsistent use of prime notation .
For instance, 4-methylfentanyl, 4'-methylfentanyl and 4"-methylfentanyl are all known compounds, as are 3-methylthio-fentanyl and 3-methyl-thiofentanyl, all of which have varying potencies and pharmacokinetics.
Confusion between different positional isomers is especially significant in the case of fentanyls because of the huge variation in potency between different members of the class. [ 54 ] The weakest compounds such as benzylfentanyl are around the same potency as codeine (i.e. approximately 1/10th the potency of morphine ), while the strongest compounds such as carfentanil and ohmefentanil can be over 10,000x more potent than morphine, meaning there is a 100,000-fold variation in potency between the strongest and weakest fentanyl derivatives. This means that two positional isomers with the same molecular weight, which may be difficult to tell apart without detailed chemical analysis, may be hundreds or even thousands of times different in pharmacological potency. Also the wide variety of substitutions that have been used on the basic fentanyl structure, each of which can either reduce or increase the potency, can be unpredictable when used in combination, so it may be impossible to estimate the likely potency of newly discovered analogues until pharmacological testing has been carried out. | https://en.wikipedia.org/wiki/List_of_fentanyl_analogues |
[ 1 ] Computers have often been used as fictional objects in literature , films , and in other forms of media . Fictional computers may be depicted as considerably more sophisticated than anything yet devised in the real world. Fictional computers may be referred to with a made-up manufacturer's brand name and model number or a nickname.
This is a list of computers or fictional artificial intelligences that have appeared in notable works of fiction . The work may be about the computer, or the computer may be an important element of the story. Only static computers are included. Robots and other fictional computers that are described as existing in a mobile or humanlike form are discussed in a separate list of fictional robots and androids .
[ 1 ] [ 2 ] | https://en.wikipedia.org/wiki/List_of_fictional_computers |
This list contains fictional chemical elements , materials, isotopes or subatomic particles that either a) play a major role in a notable work of fiction, b) are common to several unrelated works, or c) are discussed in detail by independent sources.
In the "Wages of Fire" episode Big Guy and Rusty the Boy Robot , it is revealed that the BGY-11 is powered by a Cobalt Thorium G power core.
Inerton is used mostly in hulls of futuristic airships, serving as both armor and as a lifting body, as well as in special belts worn by the characters which allow them to leap great distances by counterbalancing the weight of their bodies.
Also mentioned in the " Biggles " story "The Adventure of the Oxidized Grotto" from Biggles - Charter Pilot (1943).
A naturally-occurring form, Energized Protodermis, is a silver-colored liquid that is a sapient being, and can transform or destroy any living thing that touches it.
Pyrholidon's in-game description is as follows:
"A pretty little puck-shaped cap of purple liquid that can bring on anything from hot flashes to military-grade psychosis. With sufficient tolerance, however, it can make any weather feel balmy – if only for a while."
Due to its ability to repel Investiture it is used along with Harmonium to create Weapons of Mass Destruction comparable to Thermonuclear weapons . These weapons of mass destruction create Atium and Lerasium as a by-product of their detonation.
In the novel, the Americans use this technology, combined with Inerton, as well as explosive rockets and radio frequencies the enemy cannot detect, in their struggle with the main antagonists, "The Hans". | https://en.wikipedia.org/wiki/List_of_fictional_elements,_materials,_isotopes_and_subatomic_particles |
This article provides a list of built-in and third-party file copying and moving software - utilities and other software used, as part of computer file management , to explicitly move and copy files and other data on demand from one location to another on a storage device .
File copying is a fundamental operation for data storage. [ citation needed ] Most popular operating systems such as Windows , macOS and Linux as well as smartphone operating systems such as Android contain built-in file copying functions as well as command line (CLI) and graphical (GUI) interfaces to filing system copy and move functions. In some cases these can be replaced or supplemented by third-party software for different, extended, or improved functionality. [ citation needed ] This article lists inbuilt as well as external software designed for this purpose.
For software designed to copy, clone, image or author entire storage devices such as CDs , DVDs , Blu-ray disks, hard drives and storage device partitions , back up data , copiers that work on storage devices as a logical unit, and more general file managers and other utilities related to file copying software, please see:
Examples of comparable operating functionality seen across file copying programs:
Generic differentiators and functions as software:
Gizmo's Freeware published a basic comparison review of a range of well-known third-party file copying software on Windows . [ 1 ] FastCopy was given top place, being highest speed and also light on system resources (the author states it uses its own cache to avoid slowing other software, and the Win32 API and C runtime rather than MFC ). Ultracopier was recognised as having a well-developed GUI interface. Unstoppable Copier was well regarded as a niche copier designed for best results with damaged media and files, but at a cost of speed. TeraCopy was also mentioned below these as also worth considering. More recently, Raymond CC's blog reviewed a similar range of software on Windows versions XP, 7, and 8, and also ranked FastCopy as the overall speed winner. [ 2 ] Both reviews are over four years old.
Operating system commands:
Notable third-party file transfer software include: | https://en.wikipedia.org/wiki/List_of_file_copying_software |
A file signature is data used to identify or verify the content of a file. Such signatures are also known as magic numbers or magic bytes and are usually appended at the beginning of the file.
Many file formats are not intended to be read as text. If such a file is accidentally viewed as a text file, its contents will be unintelligible. However, some file signatures can be recognizable when interpreted as text. In the table below, the column "ISO 8859-1" shows how the file signature appears when interpreted as text in the common ISO 8859-1 encoding, with unprintable characters represented as the control code abbreviation or symbol, or codepage 1252 character where available, or a box otherwise. In some cases the space character is shown as ␠.
tiff
whl
m3u8
*.P00 format for Power64 emulator )
Source code ) | https://en.wikipedia.org/wiki/List_of_file_signatures |
This is a list of films about computers , featuring fictional films in which activities involving computers play a central role in the development of the plot. | https://en.wikipedia.org/wiki/List_of_films_about_computers |
This is a list of notable software packages that implement the finite element method for solving partial differential equations .
This table is contributed by a FEA-compare [ 18 ] project, which provides an alternative view of this table with the first row and Feature column being fixed for ease of table exploration. | https://en.wikipedia.org/wiki/List_of_finite_element_software_packages |
Fire-retardant materials are designed to burn slowly.
Fire-retardant materials should not be confused with fire-resistant materials. A fire resistant material is one which is designed to resist burning and withstand heat . An example of a fire-resistant material is one which is used in bunker gear worn by firefighters to protect them from the flames of a burning building.
In the United Kingdom , after two significant construction fires which resulted in a combined loss of £1,500 million, The Joint Code of Practice was introduced by the Fire Protection Association (FPA), the UK's national fire safety organisation, [ 1 ] to prevent fires on buildings undergoing construction work. The Joint Code of Practice provides advice on how to prevent fires such as through the use of flame-retardant temporary protection materials: for example, some high quality floor protectors are designed to burn slowly and prevent the spread of fires.
Many common brominated flame retardants are being phased-out by manufacturers. [ 2 ] Asbestos is another fireproofing material that has been largely phased out, due to its health risks, including asbestosis and mesothelioma . | https://en.wikipedia.org/wiki/List_of_fire-retardant_materials |
In first-order logic , a first-order theory is given by a set of axioms in some
language. This entry lists some of the more common examples used in model theory and some of their properties.
For every natural mathematical structure there is a signature σ listing the constants, functions, and relations of the theory together with their arities , so that the object is naturally a σ-structure . Given a signature σ there is a unique first-order language L σ that can be used to capture the first-order expressible facts about the σ-structure.
There are two common ways to specify theories:
An L σ theory may:
The signature of the pure identity theory is empty, with no functions, constants, or relations.
Pure identity theory has no (non-logical) axioms. It is decidable.
One of the few interesting properties that can be stated in the language of pure identity theory is that of being infinite.
This is given by an infinite set of axioms stating there are at least 2 elements, there are at least 3 elements, and so on:
These axioms define the theory of an infinite set .
The opposite property of being finite cannot be stated in first-order logic for any theory that has arbitrarily large finite models: in fact any such theory has infinite models by the compactness theorem . In general if a property can be stated by a finite number of sentences of first-order logic then the opposite property can also be stated in first-order logic, but if a property needs an infinite number of sentences then its opposite property cannot be stated in first-order logic.
Any statement of pure identity theory is equivalent to either σ( N ) or to ¬σ( N ) for some finite subset N of the non-negative integers , where σ( N ) is the statement that the number of elements is in N . It is even possible to describe all possible theories in this language as follows. Any theory is either the theory of all sets of cardinality in N for some finite subset N of the non-negative integers, or the theory of all sets whose cardinality is not in N , for some finite or infinite subset N of the non-negative integers. (There are no theories whose models are exactly sets of cardinality N if N is an infinite subset of the integers.) The complete theories are the theories of sets of cardinality n for some finite n , and the theory of infinite sets.
One special case of this is the inconsistent theory defined by the axiom ∃ x ¬ x = x . It is a perfectly good theory with many good properties: it is complete, decidable, finitely axiomatizable, and so on. The only problem is that it has no models at all. By Gödel's completeness theorem, it is the only theory (for any given language) with no models. [ 1 ] It is not the same as the theory of the empty set (in versions of first-order logic that allow a model to be empty): the theory of the empty set has exactly one model, which has no elements.
A set of unary relations P i for i in some set I is called independent if for every two disjoint finite subsets A and B of I there is some element x such that P i ( x ) is true for i in A and false for i in B . Independence can be expressed by a set of first-order statements.
The theory of a countable number of independent unary relations is complete, but has no atomic models . It is also an example of a theory that is superstable but not totally transcendental .
The signature of equivalence relations has one binary infix relation symbol ~, no constants, and no functions. Equivalence relations satisfy the axioms:
Some first-order properties of equivalence relations are:
The theory of an equivalence relation with exactly 2 infinite equivalence classes is an easy example of a theory which is ω-categorical but not categorical for any larger cardinal .
The equivalence relation ~ should not be confused with the identity symbol '=': if x = y then x ~ y , but the converse is not necessarily true. Theories of equivalence relations are not all that difficult or interesting, but often give easy examples or counterexamples for various statements.
The following constructions are sometimes used to produce examples of theories with certain spectra ; in fact by applying them to a small number of explicit theories T one gets examples of complete countable theories with all possible uncountable spectra. If T is a theory in some language, we define a new theory 2 T by adding a new binary relation to the language, and adding axioms stating that it is an equivalence relation, such that there are an infinite number of equivalence classes all of which are models of T . It is possible to iterate this construction transfinitely : given an ordinal α, define a new theory by adding an equivalence relation E β for each β<α, together with axioms stating that whenever β<γ then each E γ equivalence class is the union of infinitely many E β equivalence classes, and each E 0 equivalence class is a model of T . Informally, one can visualize models of this theory as infinitely branching trees of height α with models of T attached to all leaves.
The signature of orders has no constants or functions, and one binary relation symbols ≤. (It is of course possible to use ≥, < or > instead as the basic relation, with the obvious minor changes to the axioms.)
We define x ≥ y , x < y , x > y as abbreviations for y ≤ x , x ≤ y ∧¬ y ≤ x , y < x ,
Some first-order properties of orders:
The theory DLO of dense linear orders without endpoints (i.e. no smallest or largest element) is complete, ω-categorical, but not categorical for any uncountable cardinal. There are three other very similar theories: the theory of dense linear orders with a:
Being well ordered ("any non-empty subset has a minimal element") is not a first-order property; the usual definition involves quantifying over all subsets .
Lattices can be considered either as special sorts of partially ordered sets, with a signature consisting of one binary relation symbol ≤, or as algebraic structures with a signature consisting of two binary operations ∧ and ∨. The two approaches can be related by defining a ≤ b to mean a ∧ b = a .
For two binary operations the axioms for a lattice are:
For one relation ≤ the axioms are:
First-order properties include:
Heyting algebras can be defined as lattices with certain extra first-order properties.
Completeness is not a first-order property of lattices.
The signature of graphs has no constants or functions, and one binary relation symbol R , where R ( x , y ) is read as "there is an edge from x to y ".
The axioms for the theory of graphs are
The theory of random graphs has the following extra axioms for each positive integer n :
The theory of random graphs is ω categorical, complete, and decidable, and its countable model is called the Rado graph . A statement in the language of graphs is true in this theory if and only if the probability that an n -vertex random graph models the statement tends to 1 in the limit as n goes to infinity.
There are several different signatures and conventions used for Boolean algebras :
The axioms are:
Tarski proved that the theory of Boolean algebras is decidable.
We write x ≤ y as an abbreviation for x ∧ y = x , and atom( x ) as an abbreviation for ¬ x = 0 ∧ ∀ y y ≤ x → y = 0 ∨ y = x , read as " x is an atom", in other words a non-zero element with nothing between it and 0. Here are some first-order properties of Boolean algebras:
The theory of atomless Boolean algebras is ω-categorical and complete.
For any Boolean algebra B , there are several invariants defined as follows.
Then two Boolean algebras are elementarily equivalent if and only if their invariants l , m , and n are the same. In other words, the values of these invariants classify the possible completions of the theory of Boolean algebras. So the possible complete theories are:
The signature of group theory has one constant 1 (the identity), one function of arity 1 (the inverse) whose value on t is denoted by t −1 , and one function of arity 2, which is usually omitted from terms. For any integer n , t n is an abbreviation for the obvious term for the n th power of t .
Groups are defined by the axioms
Some properties of groups that can be defined in the first-order language of groups are:
The theory of abelian groups is decidable. [ 2 ] The theory of infinite divisible torsion-free abelian groups is complete, as is the theory of infinite abelian groups of exponent p (for p prime ).
The theory of finite groups is the set of first-order statements in the language of groups that are true in all finite groups (there are plenty of infinite models of this theory). It is not completely trivial to find any such statement that is not true for all groups: one example is
"given two elements of order 2, either they are conjugate or there is a non-trivial element commuting with both of them".
The properties of being finite, or free , or simple , or torsion are not first-order. More precisely, the first-order theory of all groups with one of these properties has models that do not have this property.
The signature of (unital) rings has two constants 0 and 1, two binary functions + and ×, and, optionally, one unary negation function −.
Rings
Axioms: Addition makes the ring into an abelian group, multiplication is associative and has an identity 1, and multiplication is left and right distributive.
Commutative rings
The axioms for rings plus ∀ x ∀ y xy = yx .
Fields
The axioms for commutative rings plus ∀ x (¬ x = 0 → ∃ y xy = 1) and ¬ 1 = 0.
Many of the examples given here have only universal, or algebraic axioms. The class of structures satisfying such a theory has the property of being closed under substructure. For example, a subset of a group closed under the group actions of multiplication and inverse is again a group. Since the signature of fields does not usually include multiplicative and additive inverse, the axioms for inverses are not universal, and therefore a substructure of a field closed under addition and multiplication is not always a field. This can be remedied by adding unary inverse functions to the language.
For any positive integer n the property that all equations of degree n have a root can be expressed by a single first-order sentence:
Perfect fields
The axioms for fields, plus axioms for each prime number p stating that if p 1 = 0 (i.e. the field has characteristic p ), then every field element has a p th root.
Algebraically closed fields of characteristic p
The axioms for fields, plus for every positive n the axiom that all polynomials of degree n have a root, plus axioms fixing the characteristic. The classical examples of complete theories. Categorical in all uncountable cardinals. The theory ACF p has a universal domain property , in the sense that every structure N satisfying the universal axioms of ACF p is a substructure of a sufficiently large algebraically closed field M ⊨ A C F 0 {\displaystyle M\models ACF_{0}} , and additionally any two such embeddings N → M induce an automorphism of M .
Finite fields
The theory of finite fields is the set of all first-order statements that are true in all finite fields. Significant examples of such statements can, for example, be given by applying the Chevalley–Warning theorem , over the prime fields . The name is a little misleading as the theory has plenty of infinite models. Ax proved that the theory is decidable.
Formally real fields
The axioms for fields plus, for every positive integer n , the axiom:
That is, 0 is not a non-trivial sum of squares.
Real closed fields
The axioms for formally real fields plus the axioms:
The theory of real closed fields is effective and complete and therefore decidable (the Tarski–Seidenberg theorem ). The addition of further function symbols (e.g., the exponential function, the sine function) may change decidability .
p -adic fields
Ax & Kochen (1965) showed that the theory of p -adic fields is decidable and gave a set of axioms for it. [ 3 ]
Axioms for various systems of geometry usually use a typed language, with the different types corresponding to different geometric objects such as points, lines, circles, planes, and so on. The signature will often consist of binary incidence relations between objects of different types; for example, the relation that a point lies on a line. The signature may have more complicated relations; for example ordered geometry might have a ternary "betweenness" relation for 3 points, which says whether one lies between two others, or a "congruence" relation between 2 pairs of points.
Some examples of axiomatized systems of geometry include ordered geometry , absolute geometry , affine geometry , Euclidean geometry , projective geometry , and hyperbolic geometry . For each of these geometries there are many different and inequivalent systems of axioms for various dimensions. Some of these axiom systems include "completeness" axioms that are not first order.
As a typical example, the axioms for projective geometry use 2 types, points and lines, and a binary incidence relation between points and lines. If point and line variables are indicated by small and capital letter, and a incident to A is written as aA , then one set of axioms is
Euclid did not state all the axioms for Euclidean geometry explicitly, and the first complete list was given by Hilbert in Hilbert's axioms . This is not a first-order axiomatization as one of Hilbert's axioms is a second order completeness axiom. Tarski's axioms are a first-order axiomatization of Euclidean geometry. Tarski showed this axiom system is complete and decidable by relating it to the complete and decidable theory of real closed fields.
The signature is that of fields (0, 1, +, −, ×) together with a unary function ∂, the derivation.
The axioms are those for fields together with
For this theory one can add the condition that the characteristic is p , a prime or zero,
to get the theory DF p of differential fields of characteristic p (and similarly with the other theories below).
If K is a differential field then the field of constants k = { u ∈ K : ∂ ( u ) = 0 } . {\displaystyle k=\{u\in K:\partial (u)=0\}.} The theory of differentially perfect fields is the theory of differential fields together with the condition that the field of constants is perfect; in other words, for each prime p it has the axiom:
(There is little point in demanding that the whole field should be a perfect field , because in non-zero characteristic this implies the differential is 0.)
For technical reasons to do with quantifier elimination , it is sometimes more convenient to force the constant field to be perfect by adding a new symbol r to the signature with the axioms
The theory of the natural numbers with a successor function has signature consisting of a constant 0 and a unary function S ("successor": S ( x ) is interpreted as x +1), and has axioms:
The last axiom (induction) can be replaced by the axioms
The theory of the natural numbers with a successor function is complete and decidable, and is κ-categorical for uncountable κ but not for countable κ.
Presburger arithmetic is the theory of the natural numbers under addition, with signature consisting of a constant 0, a unary function S , and a binary function +. It is complete and decidable. The axioms are
Many of the first-order theories described above can be extended to complete recursively enumerable consistent theories. This is no longer true for most of the following theories; they can usually encode both multiplication and addition of natural numbers, and this gives them enough power to encode themselves, which implies that Gödel's incompleteness theorem applies and the theories can no longer be both complete and recursively enumerable (unless they are inconsistent).
The signature of a theory of arithmetic has:
Some authors take the signature to contain a constant 1 instead of the function S , then define S in the obvious way as St = 1 + t .
Robinson arithmetic (also called Q ). Axioms (1) and (2) govern the distinguished element 0. (3) assures that S is an injection . Axioms (4) and (5) are the standard recursive definition of addition; (6) and (7) do the same for multiplication. Robinson arithmetic can be thought of as Peano arithmetic without induction. Q is a weak theory for which Gödel's incompleteness theorem holds.
Axioms:
IΣ n is first-order Peano arithmetic with induction restricted to Σ n formulas (for n = 0, 1, 2, ...). The theory IΣ 0 is often denoted by IΔ 0 . This is a series of more and more powerful fragments of Peano arithmetic. The case n = 1 has about the same strength as primitive recursive arithmetic (PRA). Exponential function arithmetic (EFA) is IΣ 0 with an axiom stating that x y exists for all x and y (with the usual properties).
First-order Peano arithmetic , PA . The "standard" theory of arithmetic. The axioms are the axioms of Robinson arithmetic above, together with the axiom scheme of induction:
Kurt Gödel 's 1931 paper proved that PA is incomplete, and has no consistent recursively enumerable completions.
Complete arithmetic (also known as true arithmetic ) is the theory of the standard model of arithmetic, the natural numbers N . It is complete but does not have a recursively enumerable set of axioms.
For the real numbers , the situation is slightly different: The case that includes just addition and multiplication cannot encode the integers, and hence Gödel's incompleteness theorem does not apply . Complications arise when adding further function symbols (e.g., exponentiation).
Second-order arithmetic can refer to a first-order theory (in spite of the name) with two types of variables, thought of as varying over integers and subsets of the integers. (There is also a theory of arithmetic in second order logic that is called second order arithmetic. It has only one model, unlike the corresponding theory in first-order logic, which is incomplete.) The signature will typically be the signature 0, S , +, × of arithmetic, together with a membership relation ∈ between integers and subsets (though there are numerous minor variations). The axioms are those of Robinson arithmetic , together with axiom schemes of induction and comprehension .
There are many different subtheories of second order arithmetic that differ in which formulas are allowed in the induction and comprehension schemes.
In order of increasing strength, five of the most common systems
are
These are defined in detail in the articles on second order arithmetic and reverse mathematics .
The usual signature of set theory has one binary relation ∈, no constants, and no functions. Some of the theories below are "class theories" which have two sorts of object, sets and classes. There are three common ways of handling this in first-order logic:
Some first-order set theories include:
Some extra first-order axioms that can be added to one of these (usually ZF) include: | https://en.wikipedia.org/wiki/List_of_first-order_theories |
This is a list of fluid flows named after people (eponymous flows). | https://en.wikipedia.org/wiki/List_of_fluid_flows_named_after_people |
Food additives are substances added to food to preserve flavor or enhance its taste, appearance, or other qualities.
Additives are used for many purposes but the main uses are:
Caffeine and other GRAS (generally recognized as safe) additives such as sugar and salt are not required to go through the regulation process. | https://en.wikipedia.org/wiki/List_of_food_additives |
This is a list of astronomical objects formerly widely considered planets under any of the various definitions of this word in the history of astronomy. As the definition of planet has evolved, the de facto and de jure definitions of planet have changed over the millennia. As of 2024, there are eight official planets in the Solar System per the International Astronomical Union (IAU), [ 1 ] which has also established a definition for exoplanets . Several objects formerly considered exoplanets have been found actually to be stars or brown dwarfs .
Throughout antiquity, several astronomical objects were considered Classical Planets , meaning "wandering stars", not all of which are now considered planets. The moons discovered around Jupiter , Saturn and Uranus after the advent of the telescope were also initially considered planets by some. The development of more powerful telescopes resulted in the discovery of the asteroids , which were initially considered planets. Then Pluto , the first Trans-Neptunian Object , was discovered. More Trans-Neptunian Objects of the Kuiper Belt were found with the help of electronic imaging. One of these, Eris , was widely hailed as a "new planet", which prompted the 2006 recategorization of solar system bodies .
Some planetary scientists reject the 2006 definition of planet, and thus would still consider some of the objects on this list to be planets under a geophysical definition . See the list of gravitationally rounded objects of the Solar System for a list of geophysical planets.
[ 2 ] [ 3 ]
[ 5 ] [ 6 ] [ 7 ]
[ 5 ] [ 6 ] [ 7 ]
[ 8 ] [ 9 ] [ 10 ] [ 11 ] [ 6 ] [ 7 ]
[ 13 ] [ 11 ] [ 6 ] [ 7 ]
[ 14 ] [ 11 ] [ 6 ] [ 7 ]
The first asteroids to be discovered were accepted as planets in the Copernican system, since they directly orbited the Sun. By 1855 the number of known bodies in the asteroid belt had grown to 15, at which point astronomers started distinguishing these from the eight known major planets. The 1867 edition of Berliner Astronomisches Jahrbuch placed all the new bodies in the asteroid belt into a separate category as 'minor planets' or 'asteroids', by which point almost 100 asteroids had been observed. [ 16 ]
[ 17 ] [ 18 ]
[ 19 ] [ 20 ] [ 21 ] [ 22 ] [ 23 ]
[ 24 ] [ 25 ]
[ 24 ] [ 25 ] [ 26 ]
[ 25 ] [ 29 ]
Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Local Hole → Observable universe → Universe Each arrow ( → ) may be read as "within" or "part of". | https://en.wikipedia.org/wiki/List_of_former_planets |
This is a list of articles covering alternative medicine topics.
^ Tarot Card Reading | https://en.wikipedia.org/wiki/List_of_forms_of_alternative_medicine |
The following is a list of significant formulae involving the mathematical constant π . Many of these formulae can be found in the article Pi , or the article Approximations of π .
where C is the circumference of a circle , d is the diameter , and r is the radius . More generally,
where L and w are, respectively, the perimeter and the width of any curve of constant width .
where A is the area of a circle . More generally,
where A is the area enclosed by an ellipse with semi-major axis a and semi-minor axis b .
where C is the circumference of an ellipse with semi-major axis a and semi-minor axis b and a n , b n {\displaystyle a_{n},b_{n}} are the arithmetic and geometric iterations of agm ( a , b ) {\displaystyle \operatorname {agm} (a,b)} , the arithmetic-geometric mean of a and b with the initial values a 0 = a {\displaystyle a_{0}=a} and b 0 = b {\displaystyle b_{0}=b} .
where A is the area between the witch of Agnesi and its asymptotic line; r is the radius of the defining circle.
where A is the area of a squircle with minor radius r , Γ {\displaystyle \Gamma } is the gamma function .
where A is the area of an epicycloid with the smaller circle of radius r and the larger circle of radius kr ( k ∈ N {\displaystyle k\in \mathbb {N} } ), assuming the initial point lies on the larger circle.
where A is the area of a rose with angular frequency k ( k ∈ N {\displaystyle k\in \mathbb {N} } ) and amplitude a .
where L is the perimeter of the lemniscate of Bernoulli with focal distance c .
where V is the volume of a sphere and r is the radius.
where SA is the surface area of a sphere and r is the radius.
where H is the hypervolume of a 3-sphere and r is the radius.
where SV is the surface volume of a 3-sphere and r is the radius.
Sum S of internal angles of a regular convex polygon with n sides:
Area A of a regular convex polygon with n sides and side length s :
Inradius r of a regular convex polygon with n sides and side length s :
Circumradius R of a regular convex polygon with n sides and side length s :
A puzzle involving "colliding billiard balls":
is the number of collisions made (in ideal conditions, perfectly elastic with no friction) by an object of mass m initially at rest between a fixed wall and another object of mass b 2 N m , when struck by the other object. [ 1 ] (This gives the digits of π in base b up to N digits past the radix point.)
Note that with symmetric integrands f ( − x ) = f ( x ) {\displaystyle f(-x)=f(x)} , formulas of the form ∫ − a a f ( x ) d x {\textstyle \int _{-a}^{a}f(x)\,dx} can also be translated to formulas 2 ∫ 0 a f ( x ) d x {\textstyle 2\int _{0}^{a}f(x)\,dx} .
The following are efficient for calculating arbitrary binary digits of π :
Plouffe's series for calculating arbitrary decimal digits of π : [ 6 ]
In general,
where E 2 k {\displaystyle E_{2k}} is the 2 k {\displaystyle 2k} th Euler number . [ 9 ]
The last two formulas are special cases of
which generate infinitely many analogous formulas for π {\displaystyle \pi } when x ∈ Q ∖ Z . {\displaystyle x\in \mathbb {Q} \setminus \mathbb {Z} .}
Some formulas relating π and harmonic numbers are given here . Further infinite series involving π are: [ 15 ]
where ( x ) n {\displaystyle (x)_{n}} is the Pochhammer symbol for the rising factorial . See also Ramanujan–Sato series .
where the numerators are the odd primes; each denominator is the multiple of four nearest to the numerator.
Viète's formula :
A double infinite product formula involving the Thue–Morse sequence :
where ϵ n = ( − 1 ) t n {\displaystyle \epsilon _{n}=(-1)^{t_{n}}} and t n {\displaystyle t_{n}} is the Thue–Morse sequence ( Tóth 2020 ).
Infinite product representation :
where a k = 2 + a k − 1 {\displaystyle a_{k}={\sqrt {2+a_{k-1}}}} such that a 1 = 2 {\displaystyle a_{1}={\sqrt {2}}} .
where F k {\displaystyle F_{k}} is the k {\displaystyle k} th Fibonacci number.
whenever a + b + c = a b c {\displaystyle a+b+c=abc} and a {\displaystyle a} , b {\displaystyle b} , c {\displaystyle c} are positive real numbers (see List of trigonometric identities ). A special case is
The following equivalences are true for any complex z {\displaystyle z} :
Also
Suppose a lattice Ω {\displaystyle \Omega } is generated by two periods ω 1 , ω 2 {\displaystyle \omega _{1},\omega _{2}} . We define the quasi-periods of this lattice by η 1 = ζ ( z + ω 1 ; Ω ) − ζ ( z ; Ω ) {\displaystyle \eta _{1}=\zeta (z+\omega _{1};\Omega )-\zeta (z;\Omega )} and η 2 = ζ ( z + ω 2 ; Ω ) − ζ ( z ; Ω ) {\displaystyle \eta _{2}=\zeta (z+\omega _{2};\Omega )-\zeta (z;\Omega )} where ζ {\displaystyle \zeta } is the Weierstrass zeta function ( η 1 {\displaystyle \eta _{1}} and η 2 {\displaystyle \eta _{2}} are in fact independent of z {\displaystyle z} ). Then the periods and quasi-periods are related by the Legendre identity :
For more on the fourth identity, see Euler's continued fraction formula .
For more iterative algorithms, see the Gauss–Legendre algorithm and Borwein's algorithm .
The symbol ∼ {\displaystyle \sim } means that the ratio of the left-hand side and the right-hand side tends to one as n → ∞ {\displaystyle n\to \infty } .
The symbol ≃ {\displaystyle \simeq } means that the difference between the left-hand side and the right-hand side tends to zero as n → ∞ {\displaystyle n\to \infty } .
With 2 F 1 {\displaystyle {}_{2}F_{1}} being the hypergeometric function :
where
and r 2 {\displaystyle r_{2}} is the sum of two squares function .
Similarly,
where
and σ 3 {\displaystyle \sigma _{3}} is a divisor function .
More formulas of this nature can be given, as explained by Ramanujan's theory of elliptic functions to alternative bases.
Perhaps the most notable hypergeometric inversions are the following two examples, involving the Ramanujan tau function τ {\displaystyle \tau } and the Fourier coefficients j {\displaystyle \mathrm {j} } of the J-invariant ( OEIS : A000521 ):
where in both cases
Furthermore, by expanding the last expression as a power series in
and setting z = 1 / 2 {\displaystyle z=1/2} , we obtain a rapidly convergent series for e − 2 π {\displaystyle e^{-2\pi }} : [ note 3 ] | https://en.wikipedia.org/wiki/List_of_formulae_involving_π |
List of free analog and digital electronic circuit simulators , available for Windows , macOS , Linux , and comparing against UC Berkeley SPICE . The following table is split into two groups based on whether it has a graphical visual interface or not. The latter requires a separate program to provide that feature, such as Qucs-S, [ 1 ] Oregano , [ 2 ] or a schematic design application that supports external simulators, such as KiCad or gEDA . | https://en.wikipedia.org/wiki/List_of_free_electronics_circuit_simulators |
This is a list of free and open-source software for geological data handling and interpretation. The list is split into broad categories, depending on the intended use of the software and its scope of functionality.
Notice that 'free and open-source' requires that the source code is available and users are given a free software license . Simple being 'free of charge' is not sufficient—see gratis versus libre .
[ 2 ]
This important class of tools is already listed in the article List of GIS software .
The following projects have unknown licensing, licenses or other conditions which place some restriction on use or redistribution, or which depend on non-open-source software like MATLAB or XVT (and therefore do not meet the Open Source Definition from the Open Source Initiative ). | https://en.wikipedia.org/wiki/List_of_free_geology_software |
Freeware is software that is available for use at no monetary cost or for an optional fee, [ 1 ] but usually (although not necessarily) closed source with one or more restricted usage rights. Freeware is in contrast to commercial software , which is typically sold for profit, but might be distributed for a business or commercial purpose in the aim to expand the marketshare of a "premium" product. Popular examples of closed-source freeware include Adobe Reader , Free Studio and Skype . This is a list of notable software packages that meet the freeware definition. | https://en.wikipedia.org/wiki/List_of_freeware |
The following is a list of freeware software packages and applications for use in the health industry: | https://en.wikipedia.org/wiki/List_of_freeware_health_software |
This is a list of functional programming topics . | https://en.wikipedia.org/wiki/List_of_functional_programming_topics |
This is a list of fungicides . These are chemical compounds which have been registered as agricultural fungicides . The names on the list are the ISO common name for the active ingredient which is formulated into the branded product sold to end-users. [ 1 ] The University of Hertfordshire maintains a database of the chemical and biological properties of these materials, [ 2 ] including their brand names and the countries and dates where and when they have been introduced. [ 3 ] The industry-sponsored Fungicide Resistance Action Committee (FRAC) advises on the use of fungicides in crop protection and classifies the available compounds according to their chemical structures and mechanism of action so as to manage the risks of pesticide resistance developing. [ 4 ] The 2024 FRAC poster of fungicides includes the majority of chemicals listed below. [ 5 ] | https://en.wikipedia.org/wiki/List_of_fungicides |
A list of future observable astronomical events. [ 1 ] These are by no means all events, but only the notable or rare ones. In particular, it does not include solar eclipses or lunar eclipses unless otherwise notable, as they are far too numerous to list (see below for articles with lists of all these). Nor does it list astronomical events that have yet to be discovered. Some points of the list miss the last date of the events.
All these dates are in a uniform time scale such as Terrestrial Time . When converted to our ordinary solar time or Universal Time , which is decidedly non-uniform, via ?T , the dates would be about one day earlier. Because of this difference, these dates have no anniversary relation to historical dates and should not be linked to them. Furthermore, they are only astronomical dates, so they are given in the astronomical format of Year Month Day, which allows them to be ordered.
Extremely rare or remarkable astronomical events in the years after the beginning of the 11th millennium AD (Year 10,000). | https://en.wikipedia.org/wiki/List_of_future_astronomical_events |
This is a list of gases at standard conditions , which means substances that boil or sublime at or below 25 °C (77 °F) and 1 atm pressure and are reasonably stable.
This list is sorted by boiling point of gases in ascending order, but can be sorted on different values. "sub" and "triple" refer to the sublimation point and the triple point , which are given in the case of a substance that sublimes at 1 atm; "dec" refers to decomposition . "~" means approximately. Blue type items have an article available by clicking on the name.
The following list has substances known to be gases, but with an unknown boiling point.
This list includes substances that may be gases. However reliable references are not available.
This list includes substances that boil just above standard condition temperatures. Numbers are boiling temperatures in °C. | https://en.wikipedia.org/wiki/List_of_gases |
Gasoline additives may increase gasoline 's octane rating , thus allowing the use of higher compression ratios for greater efficiency and power, or act as corrosion inhibitors or lubricants . Other additives include metal deactivators , oxygenates and antioxidants .
Some additives are harmful and are regulated or banned in some countries.
Fuel additives in the United States are regulated under section 211 of the Clean Air Act (as amended in January 1995). The Environmental Protection Agency (EPA) requires the registration of all fuel additives which are commercially distributed for use in highway motor vehicles in the United States , [ 5 ] and may require testing and ban harmful additives. The EPA also regularly reviews the health and net economic benefits of Clean Air Act policies. [ 6 ]
The act also requires deposit control additives (DCAs) be added to all petrol. This type of additive is a detergent additive that acts as a cleansing agent in small passages in the carburetor or fuel injectors . This in turn serves to ensure a consistent air and fuel mixture that will contribute to better gas mileage . | https://en.wikipedia.org/wiki/List_of_gasoline_additives |
This is a list of gene families or gene complexes , i.e. sets of genes which are related ancestrally and often serve similar biological functions. These gene families typically encode functionally related proteins , and sometimes the term gene families is a shorthand for the sets of proteins that the genes encode. They may or may not be physically adjacent on the same chromosome . | https://en.wikipedia.org/wiki/List_of_gene_families |
This article contains a list of commercially available gene therapies . | https://en.wikipedia.org/wiki/List_of_gene_therapies |
This list of general science and technology awards is an index to articles about notable awards for general contributions to science and technology. These awards typically have broad scope, and may apply to many or all areas of science and/or technology. The list is organized by region and country of the sponsoring organization, but awards are not necessarily limited to people from that country. | https://en.wikipedia.org/wiki/List_of_general_science_and_technology_awards |
This is a list of general topology topics . | https://en.wikipedia.org/wiki/List_of_general_topology_topics |
While there is much commonality, different parts of the tree of life use slightly different genetic codes . [ 1 ] When translating from genome to protein, the use of the correct genetic code is essential. The mitochondrial codes are the relatively well-known examples of variation. The translation table list below follows the numbering and designation by NCBI. [ 2 ] Four novel alternative genetic codes were discovered in bacterial genomes by Shulgina and Eddy using their codon assignment software Codetta, and validated by analysis of tRNA anticodons and identity elements; [ 3 ] these codes are not currently adopted at NCBI, but are numbered here 34-37, and specified in the table below.
The alternative translation tables (2 to 37) involve codon reassignments that are recapitulated in the DNA and RNA codon tables .
Comparison of alternative translation tables for all codons (using IUPAC amino acid codes ):
Three translation tables have a peculiar status:
Other mechanisms also play a part in protein biosynthesis , such as post-transcriptional modification . | https://en.wikipedia.org/wiki/List_of_genetic_codes |
This article provides a list of genetic engineering software. | https://en.wikipedia.org/wiki/List_of_genetic_engineering_software |
Genetically modified crops are plants used in agriculture , the DNA of which has been modified using genetic engineering techniques. In most cases, the aim is to introduce a new trait to the plant which does not occur naturally in the species. As of 2015, 26 plant species have been genetically modified and approved for commercial release in at least one country. The majority of these species contain genes that make them either tolerant to herbicides or resistant to insects. Other common traits include virus resistance, delayed ripening, modified flower colour or altered composition. In 2014, 28 countries grew GM crops, and 39 countries imported but did not grow them. [ 1 ]
Regulations regarding the commercialisation of genetically modified crops are mostly conducted by individual countries. For cultivation, environmental approval determines whether a crop can be legally grown. Separate approval is generally required to use GM crops in food for human consumption or as animal feed. [ 2 ] [ 3 ]
GM crops were first planted commercially on a large scale in 1996, in the US, China, Argentina, Canada, Australia, and Mexico. [ 1 ] Some countries have approved but not actually cultivated GM crops, due to public uncertainty or further government restrictions, while at the same time, they may import GM foods for consumption. For example, Japan is a leading GM food importer, and permits but has not grown GM food crops. The European Union regulates importation of GM foods, while individual member states determine cultivation. [ 4 ] In the US, separate regulatory agencies handle approval for cultivation ( USDA , EPA ) and for human consumption ( FDA ). [ 5 ]
Two genetically modified crops have been approved for food use in some countries, but have not obtained approval for cultivation. A GM Melon engineered for delayed senescence was approved in 1999 and a herbicide tolerant GM wheat was approved in 2004.
In 2014, 181.5 million hectares of genetically modified crops were planted in 28 countries. Half of all GM crops planted were genetically modified soybeans, either for herbicide tolerance or insect resistance. Eleven countries grew modified soybean, with the USA, Brazil and Argentina accounting for 90% of the total hectarage. Of the 111 hectares of soybean grown worldwide in 2014, 82% was genetically modified in some way. Seventeen countries grew a total of 55.2 million hectares of genetically modified maize and fifteen grew 23.9 hectares of genetically modified cotton. Nine million hectares of genetically modified canola was grown with 8 million of those in Canada. Other GM crops grown in 2014 include Alfalfa (862 000 ha), sugar beet (494 000 ha) and papaya (7 475 ha). In Bangladesh a genetically modified eggplant was grown commercially for the first time on 12 ha. [ 6 ]
The majority of GM crops have been modified to be resistant to selected herbicides, usually a glyphosate or glufosinate based one. In 2014, 154 million hectares were planted with a herbicide resistant crop and 78.8 million hectares had insect resistant. This include 51.4 million hectares planted in thirteen countries that contained both herbicide tolerance and insect resistance. Less than one million hectares contained other traits, which include providing virus resistance, delaying senescence, modifying flower colour and altering the plants composition. Drought tolerant maize was planted for just the second year in the USA on 275 000 hectares. [ 6 ]
Genetically modified crops engineered to resist herbicides are now more available than conventionally bred resistant varieties. [ 7 ] They comprised 83% of the total GM crop area, equating to just under 8% of the arable land worldwide. [ 7 ] Approval has been granted to grow crops engineered to be resistant to the herbicides 2,4-dichlorophenoxyacetic acid , [ 8 ] dicamba , [ 9 ] glufosinate [ 10 ] glyphosate , [ 11 ] sulfonylurea , [ 12 ] oxynil [ 13 ] mesotrione [ 14 ] and isoxaflutole [ 15 ] Most herbicide resistant GM crops have been engineered for glyphosate tolerance, in the USA 93% of soybeans and most of the GM maize grown is glyphosate tolerant. [ 16 ]
Margarine
Emulsifiers in packaged foods [ 18 ]
high-fructose corn syrup
corn starch [ 18 ]
Soybean oil [ 18 ]
Most currently available genes used to engineer insect resistance come from the Bacillus thuringiensis bacterium. Most are in the form of delta endotoxin genes known as cry proteins, while a few use the genes that encode for vegetative insecticidal proteins . [ 24 ] Insect resistant crops target various species of coleopteran (beetles) [ 25 ] and lepidopteran (moths). [ 26 ] The only gene commercially used to provide insect protection that does not originate from B. thuringiensis is the Cowpea trypsin inhibitor (CpTI). CpTI was first approved for use cotton in 1999 and is currently undergoing trials in rice. [ 27 ] [ 28 ]
high-fructose corn syrup
corn starch [ 18 ]
Many varieties of GM crops contain more than one resistance gene. This could be in the form of multiple insect resistant genes, multiple herbicide tolerance genes or a combination of the herbicide and insect resistant genes. Smartstax is a brand of GM maize that has eight different genes added to it, making it resistant to two types of herbicides and toxic to six different species of insects. [ 33 ]
While most crops are engineered to resist insects or tolerate herbicides some crops have been developed for other traits. Flowers have been engineered to display colours that they cannot do so naturally (in particular the blue color in roses ). A few crops, like the genetically modified papaya , are engineered to resist viruses. Other modifications alter the plants composition, with the aim of making it more nutritious, longer lasting or more industrially useful. Recently crops engineered to tolerate drought have been commercialised.
Margarine
Emulsifiers in packaged foods [ 18 ]
high-fructose corn syrup
corn starch [ 18 ]
Soybean oil [ 18 ]
First GM food (see Flavr Savr )
Blackspot bruise tolerance
Late blight resistance
The following graph shows the area planted in GM crops in the five largest GM crop producing countries. The area planted is presented along the y axis in thousands of hectares while the year is along the x axis. [ N 4 ] | https://en.wikipedia.org/wiki/List_of_genetically_modified_crops |
A geometer is a mathematician whose area of study is the historical aspects that define geometry , instead of the analytical geometric studies that becomes conducted from geometricians.
Some notable geometers and their main fields of work, chronologically listed, are: | https://en.wikipedia.org/wiki/List_of_geometers |
This is a list of geometric topology topics . | https://en.wikipedia.org/wiki/List_of_geometric_topology_topics |
Glycoside hydrolases (O-Glycosyl hydrolases) EC 3.2.1. are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of numerous different families. [ 1 ] [ 2 ] [ 3 ] This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. [ 4 ] Because the fold of proteins is better conserved than their sequences, some of the families can be grouped in 'clans'. As of October 2011, CAZy includes 128 families of glycosyl hydrolases and 14 clans. | https://en.wikipedia.org/wiki/List_of_glycoside_hydrolase_families |
This is a list of graph theory topics , by Wikipedia page.
See glossary of graph theory for basic terminology.
See list of network theory topics | https://en.wikipedia.org/wiki/List_of_graph_theory_topics |
During the 1980s and 1990s, a relatively large number of companies appeared selling primarily 2D graphics cards and later 3D . Most of those companies have subsequently disappeared, as the increasing complexity of GPUs substantially increased research and development costs. Many of these companies subsequently went bankrupt or were bought out. Amongst the notable discrete graphics card vendors, AMD and Nvidia are the only ones that have lasted. In 2022, Intel entered the discrete GPU market with the Arc series and has three more generations confirmed on two year release schedules.
There are currently 103 manufacturers in this incomplete list.
Many of the companies listed below also design(ed) graphics cards. | https://en.wikipedia.org/wiki/List_of_graphics_chips_and_card_companies |
This page contains a list of observed and candidate gravitational wave events.
Direct observation of gravitational waves, which commenced with the detection of an event by LIGO in 2015, [ 1 ] plays a key role in gravitational wave astronomy . LIGO has been involved in all subsequent detections to date, with Virgo joining in August 2017. [ 2 ]
Joint observation runs of LIGO and VIRGO, designated "O1, O2, etc." span many months, with months of maintenance and upgrades in-between designed to increase the instruments sensitivity and range. Within these run periods, the instruments are capable of detecting gravitational waves.
The first run, O1, ran from September 12, 2015, to January 19, 2016, and succeeded in its first gravitational wave detection. O2 ran for a greater duration, from November 30, 2016, to August 25, 2017. [ 3 ] O3 began on April 1, 2019, which was briefly suspended on September 30, 2019, for maintenance and upgrades, thus O3a. O3b marks resuming of the run and began on November 1, 2019. Due to the COVID-19 pandemic [ 4 ] O3 was forced to end prematurely. [ 5 ] O4 began on May 24, 2023; initially planned for March, the project needed more time to stabilize the instruments.
The O4 observing run, initially planned to end after one year, has been extended to run until 7 October 2025, following plans to make further upgrades for the O5 run. [ 2 ] [ 6 ] Updated observing plans are published on the official website, containing the latest information on these runs. [ 6 ] There was a two month commissioning break from January to March 2024, and another from 1 April to a planned 4 June 2025, after which observations will resume for the remainder of O4. [ 7 ] As of May 2025, O5 is planned to begin in late 2027.
Gravitational wave events are named starting with the prefix GW, while observations that trigger an event alert but have not (yet) been confirmed are named starting with the prefix S. [ 8 ] Six digits then indicate the date of the event, with the two first digits representing the year, the two middle digits the month and two final digits the day of observation. This is similar to the systematic naming for other kinds of astronomical event observations, such as those of gamma-ray bursts .
Probable detections that are not confidently identified as gravitational wave events are designated LVT ("LIGO-Virgo trigger"). Known gravitational wave events come from the merger of two black holes (BH), two neutron stars (NS), or a black hole and a neutron star (BHNS). [ 9 ] [ 10 ] Some objects are in the mass gap (MG) between the largest predicted neutron star masses ( Tolman–Oppenheimer–Volkoff limit ) and the smallest known black holes.
It was published in 2020 that a gamma-ray burst was detected ( GRB 190425 ) ~0.5 seconds after the LIGO trigger, lasting 6 seconds and bearing similarities to GRB170817 (such as weakness [most power in sub-100 keV, or soft X-rays ) bands], elevated energetic photon background levels [signal exceeding background by less than a factor of 2], and similar differences from other transients classified as short GRBs). Confidence was established for interpretation of a set of peaks through a control interval of only 2 days prior to the LIGO-Livingston trigger in INTEGRAL Electronic anticoincidence , could not be corroborated by other instruments and wasn't initially noted as a significant event. Non-detection in other instruments may be a consequence of an Earth-occulted source as the Fermi telescope attempted follow-up. [ 36 ]
2023-05-29 18:15:00
There is possible detection of nanohertz waves by observation of the timing of pulsars , but they have not been confirmed at the 5 sigma level of confidence, as of 2023 [update] . [ 59 ]
In addition to well-constrained detections listed above, a number of low-significance detections of possible signals were made by LIGO and Virgo. Their characteristics are listed below, only including detections with a <50% chance of being noise:
From observation run O3/2019 on, observations are published as Open Public Alerts to facilitate multi-messenger observations of events. [ 63 ] [ 64 ] [ 65 ] Candidate event records can be directly accessed at the Gravitational-Wave Candidate Event Database (GraceDB). [ 66 ] On 1 April 2019, the start of the third observation run was announced with a circular published in the public alerts tracker. [ 67 ] The first O3/2019 binary black hole detection alert was broadcast on 8 April 2019. A significant percentage of O3 candidate events detected by LIGO are accompanied by corresponding triggers at Virgo.
False alarm rates are mixed, with more than half of events assigned false alarm rates greater than 1 per 20 years, contingent on presence of glitches around signal, foreground electromagnetic instability, seismic activity, and operational status of any one of the three LIGO-Virgo instruments. For instance, events S190421ar and S190425z weren't detected by Virgo and LIGO's Hanford site, respectively.
The LIGO/Virgo collaboration took a short break from observing during the month of October 2019 to improve performance and prepare for future plans, with no signals detected in that month as a result. [ 68 ]
The Kamioka Gravitational Wave Detector ( KAGRA ) in Japan became operational on 25 February 2020, [ 69 ] likely improving the detection and localization of future gravitational wave signals. [ 70 ] However, KAGRA does not report their signals in real-time on GraceDB as LIGO and Virgo do, so the results of their observation run will likely not be published until the end of O3.
The LIGO-Virgo collaboration ended the O3 run early on March 27, 2020, due to health concerns from the COVID-19 pandemic . [ 5 ] [ 71 ]
On 15 June 2022, LIGO announced to start the O4 observing run in March 2023. [ 80 ] As the date got closer, engineering challenges delayed the observing run to May 2023. [ 81 ] An engineering run to assess the sensitivity of LIGO, Virgo, and KAGRA began in April, with the Hanford detector's first operations beginning on April 29, [ 82 ] and the Livingston and Virgo detectors' first operations beginning on May 5. [ 83 ]
On March 7, 2023, a gamma-ray burst compatible with a neutron star merger was detected by the Fermi telescope and named GRB 230307A . The burst, identified as being from a host galaxy approximately 296 Mpc away, would likely have only been marginally detected at best by LIGO if it had been operating at the time, as the detectors would only later achieve a sensitivity of 160 Mpc for neutron star mergers by O4's beginning, 3 months later.
Near the end of the engineering run on 15 May 2023, LIGO announced that O4 would be beginning on 24 May 2023, running for 20 months with up to 2 months of maintenance. The LIGO detectors initially failed to achieve the hoped for 160-190 Mpc sensitivity for neutron star mergers, but did achieve an improved 130-150 Mpc sensitivity over O3's 100-140 Mpc, later improving to nearly 160 Mpc for both detectors by late 2023. Virgo was found to have both a damaged mirror and other new, unknown noise sources, limiting its sensitivity to just 31-35 Mpc (similar to its performance during O2 in 2017, and lower than O3's 40-50 Mpc.) As a result, Virgo spent most of 2023 in commissioning, with a deadline of March 2024 to improve its sensitivity before joining O4. KAGRA achieved its planned 1 Mpc sensitivity before returning to commissioning in July, with plans to rejoin at an improved 10 Mpc sensitivity by early 2024. However, the M w 7.5 2024 Noto earthquake occurred on 1 January 2024 only 103 kilometres (64 mi) from KAGRA, damaging the detector's sensitive instruments and delaying its development by at least several months.
On 18 May 2023, near the end of the engineering run and shortly before O4 proper, the first candidate gravitational wave event was detected. Four more were detected before the official beginning of the run. In October, LIGO announced a planned pause between January and March 2024, for a mid-run commissioning break intended to reduce noise and improve the uptime of the detectors.
The O4b run began in April 2024 with the addition of the Virgo detector at a sensitivity of 55 Mpc. The Livingston detector achieved an increased sensitivity of 170-175 Mpc, while the Hanford detector maintained its pre-break sensitivity of 155-160 Mpc. Due to a variety of factors including delays in technologies required for O5, the decision was made in June 2024 to extend O4 by several months to June 2025, with O5 expected to begin in late 2027 or early 2028. | https://en.wikipedia.org/wiki/List_of_gravitational_wave_observations |
Growth hormone secretagogues or GH secretagogues ( GHSs ) are a class of drugs which act as secretagogues (i.e., induce the secretion ) of growth hormone (GH). [ 1 ] They include agonists of the ghrelin/growth hormone secretagogue receptor (GHSR), such as ghrelin (lenomorelin), pralmorelin (GHRP-2), GHRP-6 , examorelin (hexarelin), ipamorelin , and ibutamoren (MK-677), [ 1 ] [ 2 ] and agonists of the growth hormone-releasing hormone receptor (GHRHR), such as growth hormone-releasing hormone (GHRH, somatorelin), CJC-1295 , [ 3 ] sermorelin , [ 4 ] and tesamorelin . [ 5 ]
Many of them also induce the secretion of insulin-like growth factor 1 (IGF-1), [ 6 ] as well as of other hypothalamic-pituitary hormones such as prolactin and cortisol . The main clinical application of these agents is the treatment of growth hormone deficiency . [ 7 ] They also see black market use, similarly to anabolic steroids , for bodybuilding purposes.
Note that while ulimorelin is a ghrelin receptor agonist, it is not a GHS as it is peripherally selective and has little or no effect on GH secretion. [ 9 ] Likewise, Adenosine is capable of eliciting hunger response as a ghrelin agonist but has little to no effect on GH secretion. [ 8 ]
This hormonal preparation article is a stub . You can help Wikipedia by expanding it . | https://en.wikipedia.org/wiki/List_of_growth_hormone_secretagogues |
This is a list of notable scorewriter software for creating and editing tablature notation for guitar and other fretted instruments.
The first tablature program was written for the Amstrad CPC 464 in 1986. "Tab Composer CPC" was implemented in Locomotive BASIC 1.0. It offered a multi-page graphical WYSIWYG , 3-channel polyphonic playback and volume and tone envelope functionality, as well as save and load. BASIC programs could be generated for direct playback without the program as well, facilitating easy integration of the created musical content into other programs such as games. The user interface was in German only.
An attempt was made to publish the program as a type-in listing in the German Happy Computer [ de ] magazine. The program was rejected mainly due to poor (handwritten) documentation, and a tedious user interface. The author is still in possession of the original correspondence with the Happy Computer editorial staff, including the letter of rejection. | https://en.wikipedia.org/wiki/List_of_guitar_tablature_software |
This is a list of notable software for haplotype estimation and genotype imputation .
Alphabetical order: | https://en.wikipedia.org/wiki/List_of_haplotype_estimation_and_genotype_imputation_software |
This is a list of missions supporting heliophysics , including solar observatory missions, solar orbiters, and spacecraft studying the solar wind . [ 1 ] | https://en.wikipedia.org/wiki/List_of_heliophysics_missions |
This is a list of herbicides . These are chemical compounds which have been registered as herbicides . The names on the list are the ISO common name for the active ingredient which is formulated into the branded product sold to end-users. [ 1 ] The University of Hertfordshire maintains a database of the chemical and biological properties of these materials, [ 2 ] including their brand names and the countries and dates where and when they have been introduced. [ 3 ] The industry-sponsored Herbicide Resistance Action Committee (HRAC) advises on the use of herbicides in crop protection and classifies the available compounds according to their chemical structures and mechanism of action so as to manage the risks of pesticide resistance developing. [ 4 ] The 2024 HRAC poster of herbicide modes of action includes the majority of chemicals listed below. [ 5 ]
The Weed Science Society of America also classifies herbicides by their mechanism of action, [ 6 ] [ 7 ] with the HRAC classification system. | https://en.wikipedia.org/wiki/List_of_herbicides |
Many gases have toxic properties, which are often assessed using the LC 50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits ( TLV , TWA/PEL , STEL , or REL ) determined by the ACGIH professional association. Some, but by no means all, toxic gases are detectable by odor , which can serve as a warning. Among the best known toxic gases are carbon monoxide , chlorine , nitrogen dioxide and phosgene . | https://en.wikipedia.org/wiki/List_of_highly_toxic_gases |
Many projects have attempted to use the Gnutella network, since its introduction in early 2000. This list enumerates abandoned or discontinued projects.
Software that still work but dropped the GNUtella protocol.
Mutella was a Gnutella client developed by Max Zaitsev and Gregory Block. It had two user interfaces , one for textmode use and another called remote control , which ran on an integrated web server and was used by a web browser . The first public version of Mutella was published on October 6, 2001.
The Mutella logo was changed into a squid somewhere around version 4.1. Before this change the logo used to be an Ouroboros . There was a blue and a black version of the ouroboros logo.
Slashdot reports that LimeWire and SwapNut used the same code. The website was www.swapnut.com .
XoloX / ˈ z oʊ l ɒ k s / was a Gnutella -based peer-to-peer file sharing application for Windows . It advertised having no spyware , adware , or hijackware . However, upon installation, it prompted the user to install programs suspected to be of that kind. Also, Microsoft Anti-Spyware detected adware programs when you started to install the program. | https://en.wikipedia.org/wiki/List_of_historical_Gnutella_clients |
Home automation software is software that facilitates control of common appliances found in a home, office, or sometimes a commercial setting, such as lights, HVAC equipment, access control, sprinklers, and other devices. It usually provides for scheduling tasks, such as turning sprinklers on at the appropriate time, and event handling, such as turning lights on when motion is detected. Typically the application will support multiple interfaces to the outside world, such as XMPP , email , Z-Wave , and X10 .
The user interface of home automation software is often based on a client-server model, such as a web UI or a smartphone app, or some combination thereof. More advanced applications will allow users to write scripts in a programming language to handle more complex tasks. There are currently many competing home automation standards for both hardware and software.
This is a list of software across multiple platforms which is designed to perform home automation .
This is a list of platforms that require custom, closed hardware for home automation. | https://en.wikipedia.org/wiki/List_of_home_automation_software |
This is a list of home computers , sorted alphanumerically , which lists all relevant details of their video hardware.
Home computers are the second generation of desktop computers , entering the market in 1977 and becoming common during the 1980s. A decade later they were generally replaced by IBM PC compatible "PCs", although technically home computers are also classified as personal computers .
Examples of early home computers are the TRS-80 , Atari 8-bit computers , BBC Micro , ZX Spectrum , MSX , Amstrad CPC 464 , and Commodore 64 . Examples of late home computers are MSX 2 systems, and the Amiga and Atari ST systems.
Note: in cases of manufacturers who have made both home and personal computers , only machines fitting into the home computer category are listed. Systems in the personal computer category, except for Early Macintosh PCs, are generally based on the VGA standard and use a video chip known as a Graphics Processing Unit . Very early PCs used one of the much simpler (even compared to most home computer video hardware) video display controller cards, using parts like the MDA , the Hercules Graphics Card , the CGA and the EGA standard). Only after the introduction of the VGA standard could PCs really compete with the home computers of the same era, such as the Amiga and Atari ST, or even with the MSX-2. Also, not listed are systems that are typically only gaming systems, like the Atari 2600 and the Bally Astrocade , even though these systems could sometimes be upgraded to resemble a home computer.
Early home computers all used similar hardware and software, mostly using the 6502 , the Z80 , or in a few cases the 6809 microprocessor. They could have as little as 1 KB of RAM or as much as 128K, and software-wise, they could use a small 4K BASIC interpreter, or an extended 12K or more BASIC. The basic systems were quite similar with the exception of the video display hardware. As a result, the success of a system proved to primarily rely on the performance of the video display hardware, since this had a direct implication on the kind of games that could be played on the system.
The most important aspect of a home computer was how far programmers could push the hardware to create games. A case in point is the Commodore 64 . Its microprocessor lacked advanced math functions and was relatively slow. In addition, the built-in BASIC interpreter lacked any sort of graphics commands, as it was the same version that was developed for the older Commodore PET (a computer without any high-resolution graphics capabilities at all). However, these drawbacks were of little consequence, because the C64 had the VIC-II chip. When accessed by machine language programs, the graphic capabilities of this chip made it practical to develop arcade-style games on a home system. [ 1 ] Additionally, specific machine language code exploiting quirks of the VIC-II chip allowed for special tricks to draw even better pictures out of the VIC-II chip. [ 2 ] The comparatively large memory and the audio capabilities of the C64 also lent themselves well toward the production of larger games.
An example of the opposite is the Aquarius by Mattel which had such incredibly limited video hardware that it was retracted from the market after only four months due to poor sales.
One major problem that early computer video hardware had to overcome was the video bus arbitration problem. The problem was determining a way to give both the video hardware (VDU) and the CPU continuous read access to the video RAM. The obvious solution, using interleaving time slots for the VDU and RAM was hard to implement because the logic circuits and video memory chips of the time did not have the switching speed necessary to do so. For higher resolutions, the logic and the memory chips were barely fast enough to support reading the display data, let alone for dedicating half the available time for the slow 8-bit CPU. That being said, one system, the Apple II , was one of the first to use a feature of the data-bus logic of the 6502 processor to implement a very early interleaving time slot mechanism to eliminate this problem. The BBC Micro used 4 MHz RAM with a 2 MHz 6502 in order to interleave video accesses with CPU accesses.
Most other systems used a much simpler approach, and the TRS-80 's video logic was so primitive that it simply did not have any bus arbitration at all. The CPU had access to the video memory at all times. Writing to the video RAM simply disabled the video display logic. The result was that the screen often displayed random horizontal black stripes on screen when there was heavy access to the video RAM, like during a video game .
Most systems avoided the problem by having a status register that the CPU could read, and which showed when the CPU could safely write to the video memory. That was possible because a composite video signal blanks the video output signal during the " blanking periods " of the horizontal and especially the long vertical video sync pulses. So by simply waiting for the next blanking period, the stripes were avoidable. This approach did have one disadvantage, it relied on the software not to write to the screen during the non-blanking periods. If the software ignored the status register the stripes would re-appear. Another approach, used by most other machines of the time, was to temporarily stop the CPU using the "WAIT/BUSRQ" ( Z80 ) "WAIT" ( 6809 ) or "SYNC" (6502) control signal whenever the CPU tried to write to the screen during a non-blanking period. Yet another, more advanced, the solution was to add a hardware FIFO so that the CPU could write to the FIFO instead of directly to the RAM chips, which were updated from the FIFO during a blanking interval by special logic circuitry. Some later systems started using special "two-port" video memory, called VRAM , that had independent data output pins for the CPU interface and the video logic.
There are two main categories of solutions for a home computer to generate a video signal:
Systems in the first category were the most flexible and could offer a wide range of (sometimes unique) capabilities, but generally speaking, the second category could offer a much more complex system for a comparatively lower price.
The VDC based systems can be divided into four sub-categories:
A " - " in a table cell means that the answer is irrelevant, unknown, or in another way has no meaning, for example, the sprite size of a system that does not support hardware sprites.
A " ? " in a table cell means that the entry has not yet been determined. if a ? follows an entry it means that other options than the listed ones may also exist
" Mono " in a table cell means monochrome that is, for example, black on white, or black on green.
Semi: 64×48 [ 16 ] Mono
Semi: 64x96 or 128x48 [ 24 ] [ 27 ] Mono using 64 characters (pseudo graphics) of the 128 characters of the optional extended character set ROM
Semi: 128x96 8 colors using part of its pseudo graphic characters set
Semi: 64×48 [ 31 ] Mono
40x21 [ 35 ] in BASIC 3.1
Semi: 80×50 using part of its pseudo graphic characters set
Semi: 128x90 [ 50 ] Mono
Semi: 64x75/90, 80x75/90, 128x75/90, 160x75/90 [ 56 ] Mono
Osborne Executive and Osborne Vixen
Semi: 64×48 [ 64 ] 8 colors
Semi: 64×48 [ 66 ] Mono
Semi: 80×50 [ 69 ] Mono
87.x1: 960+960 [ 71 ] bytes
First known system without separate text buffer
Semi: 40×48 or 80×48 16 colors
Semi: 80×75 16 colors [ 108 ]
Semi: 64x32 [ 115 ] 9 colors, 64x48 [ 116 ] 4 colors
Semi: 80x96, 160x84p/96p/192i 2 or 4 colors via soft fonts
Semi: 80x84 8 colors through soft font
Semi: 64x48 15 colors [ 137 ]
Semi: 64x48 15 colors or 128x48 Mono
Semi: 64x48 15 colors
Semi: 84x75 8 colors or 170x75 4 colors through soft font, 128x128 8 colors or 256x128 4 colors stippled [ 141 ]
Semi: 80x75 16 colors through soft font
Semi: 80x75 4 colors or 160x75 2 colors through soft font
semi: 78x75 8 or 2 colors [or 158x75 (800M, 802, 806)]
Semi: 80×50 Mono (4000) or 160×50 Mono (8000) using part of its pseudo graphic characters set
Semi: 160×72 or 128×48 8 colors
Semi: 160×72 or 128×48 Mono
Semi: Presumably 80x72 8 colors
Semi: 160x96 [ 168 ] 4 colors or presumably 80×72 [ 169 ] 16 colors
Semi: 128×128 [ 181 ] 8 colors or presumably 128×96 8 colors or 128x48 8 colors (through block graphics characters included in the font)
Semi: 80×72 [ 185 ] /120×96 [ 186 ] 8 foreground colors (4 per 6×8 or 6×9 pixels, 1 per 6-pixel line)+ 8 background colors (for the whole screen)
semi: 80×50 [ 69 ] 8 colors
Semi: 160×100 [ 191 ] [ 192 ] 8 colors
Semi: 64x32, 80x50 or 160x50 9 colors
Semi: 64×32 [ 200 ] 9 colors or 64×48 [ 201 ] 4 colors
Semi: 64×32 9 colors or 64×48 4 or 9 colors
Semi: 64×32 (64×64, 64×96 or 64×192 [ 205 ] ) [ 200 ] 9 colors, 64×48 [ 201 ] 4 colors
Semi: technically 44x46 16 colors (upper 8 unusable as foreground) using part of its PETSCII character set [ 210 ]
(semi: 80×50 16 colors using part of its pseudo graphic characters set)
(semi: 80×50 or 160x50 16 colors using part of its pseudo graphic characters set)
(semi: 80×50 16 colors using part of its pseudo graphic characters set)
("semi": 160×100 [ 221 ] 16 colors)
80×25, 40×25, 80×43 or 80×50 16 colors on 14" Monitor
640×480, 640×400, 640×350 or 320×200
Semi: 160×100 [ 228 ] 8 colors
16×7 Text in 128x56 [ 233 ] Semigraphics 16 colors
Semi: 64×48 16 colors
Semi: 64×48p, 64x53p, 64x96i or 64x106i 16 colors
[ 266 ] SP= 8
NTSC Graphics: 320×200, 640×200, 320×400, 640×400 [ 270 ] 2 to 64 colors and 4096 colors, 1280×200p or 1280x400i 4 colors
PAL Graphics: 320x256, 640x256, 320x512, 640x512 [ 270 ] 2 to 64 colors and 4096 colors, 1280×256p or 1280x512i 4 colors [ 77 ]
PAL: 320x256, 640x256, 320x512, 640x512, 1280×256p or 1280x512i
PAL: 320×256 .. 1280×512 Graphics 2 to 256, 4096 to 262144 colors
VGA: 640×480 2 to 256, 4096 to 262144 colors
Super72: 400×300 .. 800×600 (interlaced) [ 77 ] Graphics 2 to 256, 4096 to 262144 colors
PAL: 320×256 .. 1280×512
VGA: 640×480
Super72: 400×300 .. 800×600 (interlaced)
in CRT: 320×200 to 1600×608 Graphics 2,4,16,256 colors (indexed), 32768 colors (+overlay), 65536 colors (Hi-Color)
VGA: 640×480 or 800×608 [ 77 ] Graphics 2,4,16,256 colors (indexed), 32768 colors (+overlay), 65536 colors (Hi-Color)
VGA: 640×480 or 800×608
For these systems, it is established that they are based on multiple technologies. The hardware chosen to be used by these systems may have a substantial or insubstantial impact on the video they output.
Semi: 160×50 Mono with CRTC (or 80×50 16 colors with video interface controller) using part of its pseudo graphic characters set
(semi: 80×50, 160x50 or 160x100 16 colors using part of its pseudo graphic characters set)
Semi: 80×75 [ 288 ] 8 colors
Semi: 64x32 9 or 16 colors or 64x48 4, 9 or 16 colors or 80x40 16 colors; later also 80x50, 160x40, 160x50 16 colors
Semi: 80×72 [ 291 ] 8 colors
For these systems, it could not be established what technology they are based on, therefore, some information regarding them may be inaccurate.
Semi: 64x96 up to 8 Gray levels | https://en.wikipedia.org/wiki/List_of_home_computers_by_video_hardware |
The homing endonucleases are a special type of restriction enzymes encoded by introns or inteins . They act on the cellular DNA of the cell that synthesizes them; to be precise, in the opposite allele of the gene that encode them. [ 1 ]
The list includes some of the most studied examples. The following concepts have been detailed:
* : Nicking endonuclease : These enzymes cut only one DNA strand, leaving the other strand untouched. ** : Unknown cutting site : Researchers have not been able to determine the exact cutting site of these enzymes yet.
Databases and lists of restriction enzymes:
Databases of proteins: | https://en.wikipedia.org/wiki/List_of_homing_endonuclease_cutting_sites |
The Royal Society of Chemistry awards the designation of Honorary Fellow of the Royal Society of Chemistry for distinguished service in the field of chemistry.
Awardees are entitled to use the post nominal HonFRSC .
Recipients have included: [ 1 ]
Also in 2002, the fictional character Sherlock Holmes was awarded an "Extraordinary Honorary Fellowship". [ 3 ] | https://en.wikipedia.org/wiki/List_of_honorary_fellows_of_the_Royal_Society_of_Chemistry |
The following is a list of hormones found in Homo sapiens . Spelling is not uniform for many hormones. For example, current North American and international usage uses [ citation needed ] estrogen and gonadotropin, while British usage retains the Greek digraph in oestrogen and favours the earlier spelling gonadotrophin .
(or epinephrine )
(or norepinephrine )
(or Islet Amyloid Polypeptide)
(or Müllerian-inhibiting factor/hormone)
(or corticotropin)
Angiotensin
release of aldosterone from adrenal cortex dipsogen .
(or vasopressin, arginine vasopressin)
(or atriopeptin)
reducing systemic vascular resistance ,
reducing blood water, sodium and fats
In male: spermatogenesis , enhances production of androgen-binding protein by the Sertoli cells of the testes
secretion of growth hormone from anterior pituitary gland
increase insulin resistance and carbohydrate intolerance
Release Insulin-like growth factor 1 from liver
also called hypoglycemic hormone and anti ketogenic hormone ||
intake of lipids , synthesis of triglycerides in adipocytes , helps in oxidation of sugar through Krebs cycle , inhibits production of ketone bodies, inactivates phosphorylase enzyme,
Other anabolic effects
(or somatomedin)
regulate cell growth and development
In male: stimulates Leydig cell production of testosterone
Stimulates contraction of cervix and vagina . Involved in orgasm , trust between people, [ 2 ] and circadian homeostasis (body temperature, activity level, wakefulness). [ 3 ]
(Slightly) decrease blood phosphate :
(or luteotropic hormone)
Enhances effects of cholecystokinin Stops production of gastric juice
(or growth hormone–inhibiting hormone or
growth hormone release–inhibiting hormone or
somatotropin release–inhibiting factor or somatotropin release–inhibiting hormone)
Reduces smooth muscle contractions and blood flow within the intestine [ 4 ] Inhibit release of insulin from beta cells [ 5 ] Inhibit release of glucagon from alpha cells [ 5 ] Suppress the exocrine secretory action of pancreas .
(or thyrotropin)
Virilizing : maturation of sex organs , formation of scrotum , deepening of voice, growth of beard and axillary hair .
Potassium and H + secretion in kidney.
Structural:
Coagulation :
Fluid balance:
Gastrointestinal tract:
Lung function:
Males : Prevent apoptosis of germ cells [ 8 ]
Inhibition of glucose uptake in muscle and adipose tissue
Mobilization of amino acids from extrahepatic tissues
Stimulation of fat breakdown in adipose tissue anti-inflammatory and immunosuppressive
Other:
Increase absorption of calcium and phosphate from gastrointestinal tract and kidneys inhibit release of PTH | https://en.wikipedia.org/wiki/List_of_human_hormones |
The following is a list of hybrid entities from the folklore record grouped morphologically. Hybrids not found in classical mythology but developed in the context of modern popular culture are listed in § Modern fiction .
The following hybrid creatures appear in modern fiction:
The Jurassic Park franchise had these hybrids in the films, toylines, and video games. | https://en.wikipedia.org/wiki/List_of_hybrid_creatures_in_folklore |
This is a list of hydrodynamic and plasma instabilities named after people (eponymous instabilities). | https://en.wikipedia.org/wiki/List_of_hydrodynamic_instabilities_named_after_people |
This article covers known hyperaccumulators , accumulators or species tolerant to the following: Aluminium (Al), Silver (Ag), Arsenic (As), Beryllium (Be), Chromium (Cr), Copper (Cu), Manganese (Mn), Mercury (Hg), Molybdenum (Mo), Naphthalene , Lead (Pb), Selenium (Se) and Zinc (Zn).
See also:
Cs-137 activity was much smaller in leaves of larch and sycamore maple than of spruce : spruce > larch > sycamore maple. | https://en.wikipedia.org/wiki/List_of_hyperaccumulators |
This page is a list of hyperboloid structures . These were first applied in architecture by Russian engineer Vladimir Shukhov (1853–1939). Shukhov built his first example as a water tower ( hyperbolic shell ) for the 1896 All-Russian Exposition . Subsequently, more have been designed by other architects, including Le Corbusier , Antoni Gaudí , Eduardo Torroja , Oscar Niemeyer and Ieoh Ming Pei .
The shapes are doubly ruled surfaces , which can be classed as:
(Mürwik Water Tower)
(Möglingen Water Tower)
now the Wrexham Waterworld Leisure and Activity Centre
(BIS Tower) of the Bank for International Settlements
a.k.a. fr:Le Volcan (salle) (The Volcano (hall/auditorium))
(Schlossberg View Tower) a.k.a. Castle Hill Tower
(Vienna Trade Fair Tower / Exhibition-tower)
(TBZ Tower)
a.k.a. "The Torch Doha"
(BMW World)
a.k.a. the "QIPCO Tower"
(Lörmecke Tower)
a.k.a. Guangzhou Tower
(Jüberg Tower)
a.k.a. London VeloPark
(Les Essarts-le-Roi Water Tower)
a.k.a. Samspel (interaction/interplay/teamwork) | https://en.wikipedia.org/wiki/List_of_hyperboloid_structures |
A hypothetical Solar System object is a planet , natural satellite , subsatellite or similar body in the Solar System whose existence is not known, but has been inferred from observational scientific evidence. Over the years a number of hypothetical planets have been proposed, and many have been disproved. However, even today there is scientific speculation about the possibility of planets yet unknown that may exist beyond the range of our current knowledge.
Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Virgo Supercluster → Laniakea Supercluster → Local Hole → Observable universe → Universe Each arrow ( → ) may be read as "within" or "part of". | https://en.wikipedia.org/wiki/List_of_hypothetical_Solar_System_objects |
This is a list of hypothetical subatomic particles in physics .
Some theories predict the existence of additional elementary bosons and fermions that are not found in the Standard Model .
Supersymmetry predicts the existence of superpartners to particles in the Standard Model, none of which have been confirmed experimentally. The sfermions (spin-0) include:
Another hypothetical sfermion is the saxion , superpartner of the axion. Forms a supermultiplet , together with the axino and the axion, in supersymmetric extensions of Peccei–Quinn theory .
The predicted bosinos (spin 1 ⁄ 2 ) are
Just as the photon, Z and W ± bosons are superpositions of the B 0 , W 0 , W 1 , and W 2 fields, the photino , zino, and wino ± are superpositions of the bino 0 , wino 0 , wino 1 , and wino 2 . No matter if one uses the original gauginos or this superpositions as a basis, the only predicted physical particles are neutralinos and charginos as a superposition of them together with the Higgsinos.
Other superpartner categories include:
The following hypothetical particles have been proposed to explain dark energy :
The following categories are not unique or distinct: For example, either a WIMP or a WISP is also a FIP.
Hidden sector theories have also proposed forces that only interact with dark matter, like dark photons .
These hypothetical particles were claimed to be found or hypothesized to explain unusual experimental results. They relate to experimental anomalies but have not been reproduced independently or might be due to experimental errors: | https://en.wikipedia.org/wiki/List_of_hypothetical_particles |
In computing , an icon is a pictogram or ideogram displayed on a computer screen in order to help the user navigate a computer system . The icon itself is a quickly comprehensible symbol of a software tool, function, or a data file , accessible on the system and is more like a traffic sign than a detailed illustration of the actual entity it represents. [ 1 ] It can serve as an electronic hyperlink or file shortcut to access the program or data. The user can activate an icon using a mouse, pointer, finger, or voice commands . Their placement on the screen, also in relation to other icons, may provide further information to the user about their usage. [ 2 ] In activating an icon, the user can move directly into and out of the identified function without knowing anything further about the location or requirements of the file or code.
Icons as parts of the graphical user interface of a computer system, in conjunction with windows , menus and a pointing device (mouse), belong to the much larger topic of the history of the graphical user interface that has largely supplanted the text-based interface for casual use.
The computing definition of "icon" can include three distinct semiotical elements: Icon , which resembles its referent (such as a road sign for falling rocks).
This category includes stylized drawings of objects from the office environment or from other professional areas such as printers, scissors, file cabinets and folders.
Index , which is associated with its referent (smoke is a sign of fire).
This category includes stylized drawings used to refer to actions " printer " and "print", " scissors " and " cut " or " magnifying glass " and "search".
Symbol , which is related to its referent only by convention (letters, musical notation, mathematical operators etc.).
This category includes standardized symbols found across many electronic devices , such as the power on/off symbol and the USB icon.
The majority of icons are encoded and decoded using metonymy , synecdoche , and metaphor .
An example of metaphorical representation characterizes all the major desktop-based computer systems including the desktop that uses an iconic representation of objects from the 1980s office environment to transpose attributes from a familiar context/object to an unfamiliar one. This is known as skeuomorphism , and an example is the use of the floppy disk to represent saving data; even though floppy disks have been obsolete for roughly a quarter century, it is still recognized as "the save icon".
Metonymy is in itself a subset of metaphors that use one entity to point to another related to it such as using a fluorescent bulb instead of a filament one to represent power saving settings.
Synecdoche is considered as a special case of metonymy, in the usual sense of the part standing for the whole such as a single component for the entire system, speaker driver for the entire audio system settings.
Additionally, a group of icons can be categorised as brand icons, used to identify commercial software programs and are related to the brand identity of a company or software. These commercial icons serve as functional links on the system to the program or data files created by a specific software provider. Although icons are usually depicted in graphical user interfaces , icons are sometimes rendered in a TUI using special characters such as MouseText or PETSCII .
The design of all computer icons is constricted by the limitations of the device display. They are limited in size, with the standard size of about a thumbnail for both desktop computer systems and mobile devices. They are frequently scalable, as they are displayed in different positions in the software, a single icon file such as the Apple Icon Image format can include multiple versions of the same icon optimized to work at a different size, in colour or grayscale as well as on dark and bright backgrounds.
The colors used, for both the image and the icon background, should stand out on different system backgrounds and among each other. The detailing of the icon image needs to be simple, remaining recognizable in varying graphical resolutions and screen sizes. Computer icons are by definition language-independent but often not culturally independent; they do not rely on letters or words to convey their meaning. These visual parameters place rigid limits on the design of icons, frequently requiring the skills of a graphic artist in their development.
Because of their condensed size and versatility, computer icons have become a mainstay of user interaction with electronic media. Icons also provide rapid entry into the system functionality. On most systems, users can create and delete, replicate, select , click or double-click standard computer icons and drag them to new positions on the screen to create a customized user environment. [ 2 ]
A series of recurring computer icons are taken from the broader field of standardized symbols used across a wide range of electrical equipment. Examples of these are the power symbol and the USB icon, which are found on a wide variety of electronic devices. The standardization of electronic icons is an important safety-feature on all types of electronics, enabling a user to more easily navigate an unfamiliar system. As a subset of electronic devices, computer systems and mobile devices use many of the same icons; they are corporated into the design of both the computer hardware and on the software. On the hardware, these icons identify the functionality of specific buttons and plugs. [ 3 ] In the software, they provide a link into the customizable settings. [ 4 ]
System warning icons also belong to the broader area of ISO standard warning signs. These warning icons, first designed to regulate automobile traffic in the early 1900s, have become standardized and widely understood by users without the necessity of further verbal explanations. In designing software operating systems, different companies have incorporated and defined these standard symbols as part of their graphical user interface. For example, the Microsoft MSDN [ 5 ] defines the standard icon use of error, warning, information and question mark icons as part of their software development guidelines. [ 6 ]
Different organizations are actively involved in standardizing these icons, as well as providing guidelines for their creation and use. The International Electrotechnical Commission (IEC) has defined "Graphical symbols for use on equipment", published as IEC 417, a document which displays IEC standardized icons. Another organization invested in the promotion of effective icon usage is the ICT (information and communications technologies), which has published guidelines for the creation and use of icons. [ 2 ] Many of these icons are available on the Internet, either to purchase or as freeware to incorporate into new software.
An icon is a signifier pointing to the signified . Easily comprehendible icons will make use of familiar visual metaphors directly connected to the signified : actions the icon initiate or the content that would be revealed. Metaphors , metonymy and synecdoche are used to encode the meaning in an icon system.
The signified can have multiple natures: virtual objects such as files and applications , actions within a system or an application (e.g. snap a picture, delete, rewind, connect/disconnect etc...), action in the physical world (e.g. print, eject DVD, change volume or brightness etc...) as well as physical objects (e.g. monitor , compact disk , mouse , printer etc...).
A subgroup of the more visually rich icons is based on objects lifted from a 1970 physical office space and desktop environment. It includes the basic icons used for a file, file folder, trashcan, inbox, together with the spatial real estate of the screen, i.e. the electronic desktop. This model originally enabled users, familiar with common office practices and functions, to intuitively navigate the computer desktop and system. (Desktop Metaphor, pg 2). The icons stand for objects or functions accessible on the system and enable the user to do tasks common to an office space. These desktop computer icons developed over several decades; data files in the 1950s, the hierarchical storage system (i.e. the file folder and filing cabinet) in the 1960s, and finally the desktop metaphor itself (including the trashcan) in the 1970s. [ 7 ]
Dr. David Canfield Smith associated the term "icon" with computing in his landmark 1975 PhD thesis "Pygmalion: A Creative Programming Environment". [ 8 ] [ 9 ] In his work, Dr. Smith envisioned a scenario in which "visual entities", called icons, could execute lines of programming code, and save the operation for later re-execution. [ 10 ] Dr. Smith later served as one of the principal designers of the Xerox Star , which became the first commercially available personal computing system based on the desktop metaphor when it was released in 1981. "The icons on [the desktop] are visible concrete embodiments of the corresponding physical objects." [ 11 ] The desktop and icons displayed in this first desktop model are easily recognizable by users several decades later, and display the main components of the desktop metaphor GUI.
This model of the desktop metaphor has been adopted by most personal computing systems in the last decades of the 20th century; it remains popular as a "simple intuitive navigation by single user on single system." [ 7 ] It is only at the beginning of the 21st century that personal computing is evolving a new metaphor based on Internet connectivity and teams of users, cloud computing . In this new model, data and tools are no longer stored on the single system, instead they are stored someplace else, "in the cloud". The cloud metaphor is replacing the desktop model; it remains to be seen how many of the common desktop icons (file, file folder, trashcan, inbox, filing cabinet) find a place in this new metaphor.
A further type of computer icon is more related to the brand identity of the software programs available on the computer system. These brand icons are bundled with their product and installed on a system with the software. They function in the same way as the hyperlink icons described above, representing functionality accessible on the system and providing links to either a software program or data file. Over and beyond this, they act as a company identifier and advertiser for the software or company. [ 12 ]
Because these company and program logos represent the company and product itself, much attention is given to their design, done frequently by commercial artists. To regulate the use of these brand icons, they are trademark registered and are considered part of the company's intellectual property.
In closed systems such as iOS and Android , the use of icons is to a degree regulated or guided [ 13 ] to create a sense of consistency in the UI .
On some GUI systems (e.g. Windows), on an icon which represents an object (e.g. a file) a certain additional subsystem can add a smaller secondary icon, laid over the primary icon and usually positioned in one of its corners, to indicate the status of the object which is represented with the primary icon. For instance, the subsystem for locking files can add a "padlock" overlay icon on an icon which represents a file in order to indicate that the file is locked.
In order to display the number of icons representing the growing complexity offered on a device, different systems have come up with different solutions for screen space management. The computer monitor continues to display primary icons on the main page or desktop, allowing easy and quick access to the most commonly used functions for a user. This screen space also invites almost immediate user customization, as the user adds favourite icons to the screen and groups related icons together on the screen. Secondary icons of system programs are also displayed on the task bar or the system dock . These secondary icons do not provide a link like the primary icons, instead, they are used to show availability of a tool or file on the system. [ 7 ] [ 14 ]
Spatial management techniques play a bigger role in mobile devices with their much smaller screen real estate. In response, mobile devices have introduced, among other visual devices, scrolling screen displays and selectable tabs displaying groups of related icons. Even with these evolving display systems, the icons themselves remain relatively constant in both appearance and function.
Above all, the icon itself must remain clearly identifiable on the display screen regardless of its position and size. Programs might display their icon not only as a desktop hyperlink, but also in the program title bar, on the Start menu, in the Microsoft tray or the Apple dock . In each of these locations, the primary purpose is to identify and advertise the program and functionality available. This need for recognition in turn sets specific design restrictions on effective computer icons.
In order to maintain consistency in the look of a device, OS manufacturers offer detailed guidelines for the development and use of icons on their systems. [ 15 ] [ 16 ] [ 17 ] This is true for both standard system icons and third party application icons to be included in the system. The system icons currently in use have typically gone through widespread international acceptance and understandability testing. Icon design factors have also been the topic for extensive usability studies. The design itself involves a high level of skill in combining an attractive graphic design with the required usability features. [ 2 ] [ 18 ]
The icon needs to be clear and easily recognizable, able to display on monitors of widely varying size and resolutions. Its shape should be simple with clean lines, without too much detailing in the design. Together with the other design details, the shape also needs to make it unique on the display and clearly distinguishable from other icons.
The icon needs to be colorful enough to easily pick out on the display screen, and contrast well with any background. With the increasing ability to customize the desktop, it is important for the icon itself to display in a standard color which cannot be modified, retaining its characteristic appearance for immediate recognition by the user. Through color it should also provide some visual indicator as to the icon state; activated, available or currently not accessible ("greyed out").
The standard icon is generally the size of an adult thumb, enabling both easy visual recognition and use in a touchscreen device. For individual devices the display size correlates directly to the size of the screen real estate and the resolution of the display. Because they are used in multiple locations on the screen, the design must remain recognizable at the smallest size, for use in a directory tree or title bar, while retaining an attractive shape in the larger sizes. In addition to scaling, it may be necessary to remove visual details or simplify the subject between discrete sizes. Larger icons serve also as part of the accessibility features for the visually impaired on many computer systems. The width and height of the icon are the same (1:1 aspect ratio ) in almost all areas of traditional use.
Icons can also be augmented with iconographic motion - geometric manipulations applied to a graphical element over time, for example, a scale, rotation, or other deformation. One example is when application icons "wobble" in iOS to convey to the user they are able to be repositioned by being dragged. This is different from an icon with animated graphics, such as a Throbber . In contrast to static icons and icons with animated graphics, kinetic behaviors do not alter the visual content of an element (whereas fades, blurs, tints, and addition of new graphics, such as badges, exclusively alter an icon's pixels). Stated differently, pixels in an icon can be moved, rotated, stretched, and so on - but not altered or added to. Research has shown iconographic motion can act as a powerful and reliable visual cue, a critical property for icons to embody. [ 19 ]
In its primary function as a symbolic image, the icon design should ideally be divorced from any single language. For products which are targeting the international marketplace, the primary design consideration is that the icon is non-verbal; localizing text in icons is costly and time-consuming.
Beyond text, there are other design elements which can be dependent upon the cultural context for interpretation. These include color, numbers, symbols, body parts and hand gestures. Each of these elements needs to be evaluated for their meaning and relevance across all markets targeted by the product. [ 20 ]
Other graphical devices used in the computer user interface fulfill GUI functions on the system similar to the computer icons described above. However each of these related graphical devices differs in one way or another from the standard computer icon.
The graphical windows on the computer screen share some of the visual and functional characteristics of the computer icon. Windows can be minimized to an icon format to serve as a hyperlink to the window itself. Multiple windows can be open and even overlapping on the screen. However where the icon provides a single button to initiate some function, the principal function of the window is a workspace, which can be minimized to an icon hyperlink when not in use. [ 21 ]
Over time, certain GUI widgets have gradually appeared which are useful in many contexts. These are graphical controls which are used across computer systems and can be intuitively manipulated by the user even in a new context because the user recognises them from having seen them in a more familiar context. Examples of these control widgets are scroll bars, sliders, listboxes and buttons used in many programs. Using these widgets, a user is able to define and manipulate the data and the display for the software program they are working with. The first set of computer widgets was originally developed for the Xerox Alto. Now they are commonly bundled in widget toolkits and distributed as part of a development package. These control widgets are standardized pictograms used in the graphical interface, they offer an expanded set of user functionalities beyond the hyperlink function of computer icons. [ 22 ]
Another GUI icon is exemplified by the smiley face, a pictogram embedded in a text message . The smiley, and by extension other emoticons , are used in computer text to convey information in a non-verbal binary shorthand, frequently involving the emotional context of the message. These icons were first developed for computers in the 1980s as a response to the limited storage and transmission bandwidth used in electronic messaging. Since then they have become both abundant and more sophisticated in their keyboard representations of varying emotions. They have developed from keyboard character combinations into real icons. They are widely used in all forms of electronic communications, always with the goal of adding context to the verbal content of the message. In adding an emotional overlay to the text, they have also enabled electronic messages to substitute for and frequently supplant voice-to-voice messaging.
These emoticons are very different from the icon hyperlinks described above. They do not serve as links, and are not part of any system function or computer software. Instead they are part of the communication language of users across systems. For these computer icons, customization and modifications are not only possible but in fact expected of the user. [ 23 ]
A text hyperlink performs much the same function as the functional computer icon: it provides a direct link to some function or data available on the system. Although they can be customized, these text hyperlinks generally share a standardized recognizable format, blue text with underlining. Hyperlinks differ from functional computer icons in that they are normally embedded in text, whereas icons are displayed as stand-alone on the screen real estate. They are also displayed in text, either as the link itself or a friendly name, whereas icons are defined as being primarily non-textual.
Because of the design requirements, icon creation can be a time-consuming and costly process. There are a plethora of icon creation tools to be found on the Internet, ranging from professional level tools through utilities bundled with software development programs to stand-alone freeware. [ 24 ] Given this wide availability of icon tools and icon sets, a problem can arise with custom icons which are mismatched in style to the other icons included on the system.
Icons underwent a change in appearance from the early 8-bit pixel art used pre-2000 to a more photorealistic appearance featuring effects such as softening, sharpening, edge enhancement, a glossy or glass-like appearance, or drop shadows which are rendered with an alpha channel .
Icon editors used on these early platforms usually contain a rudimentary raster image editor capable of modifying images of an icon pixel by pixel, by using simple drawing tools, or by applying simple image filters. Professional icon designers seldom modify icons inside an icon editor and use a more advanced drawing or 3D modeling application instead.
The main function performed by an icon editor is generation of icons from images. An icon editor resamples a source image to the resolution and color depth required for an icon. Other functions performed by icon editors are icon extraction from executable files (exe, dll), creation of icon libraries, or saving individual images of an icon.
All icon editors can make icons for system files (folders, text files, etc.), and for web pages.
These have a file extension of . ICO for Windows and web pages or . ICNS for the Macintosh. If the editor can also make a cursor, the image can be saved with a file extension of . CUR or . ANI for both Windows and the Macintosh. Using a new icon is simply a matter of moving the image into the correct file folder and using the system tools to select the icon. In Windows XP you could go to My Computer, open Tools on the explorer window, choose Folder Options, then File Types, select a file type, click on Advanced and select an icon to be associated with that file type.
Developers also use icon editors to make icons for specific program files. Assignment of an icon to a newly created program is usually done within the Integrated Development Environment used to develop that program. However, if one is creating an application in the Windows API he or she can simply add a line to the program's resource script before compilation. Many icon editors can copy a unique icon from a program file for editing. Only a few can assign an icon to a program file, a much more difficult task. There are also resource editing tools that allow users to extract or replace icons embedded in Windows executable files, such as Resource Hacker or Resource Tuner .
Simple icon editors and image-to-icon converters are also available online as web applications .
This is a list of notable computer icon software.
The following is a list of raster graphic applications capable of creating and editing icons: | https://en.wikipedia.org/wiki/List_of_icon_software |
This is a list of immune cells , also known as white blood cells , white cells , leukocytes , or leucocytes . They are cells involved in protecting the body against both infectious disease and foreign invaders . [ 1 ] | https://en.wikipedia.org/wiki/List_of_immune_cells |
Notable in-memory database system software includes:
Altibase Corporation has recently made the decision to discontinue the Altibase 7.1 open source edition, effective March 17, 2023, on its Github page (https://github.com/Altibase/altibase).
With full SQL support, one of the main use cases for Apache Ignite is the in-memory database which scales horizontally and provides ACID transactions.
In SQL Server 2012, an in-memory technology called xVelocity column-store indexes targeted for data-warehouse workloads.
[ 1 ] | https://en.wikipedia.org/wiki/List_of_in-memory_databases |
A technical argument by a trusted author, which is hard to check and looks similar to arguments known to be correct, is hardly ever checked in detail.
This page lists notable examples of incomplete or incorrect published mathematical proofs . Most of these were accepted as complete or correct for several years but later discovered to contain gaps or errors. There are both examples where a complete proof was later found, or where the alleged result turned out to be false. | https://en.wikipedia.org/wiki/List_of_incomplete_proofs |
The International Rubber Science Hall of Fame recognizes the careers of notable professionals in rubber technology. [ 1 ] It is jointly sponsored by the Maurice Morton Institute of Polymer Science at The University of Akron and the Rubber Division of the American Chemical Society .
The Goodyear Polymer Center at the University of Akron houses the Hall of Fame's portrait gallery. [ 2 ]
The following are members of the International Rubber Hall of Fame: | https://en.wikipedia.org/wiki/List_of_inductees_in_the_International_Rubber_Science_Hall_of_Fame |
This article lists Wikipedia articles about named mathematical inequalities . | https://en.wikipedia.org/wiki/List_of_inequalities |
Although most compounds are referred to by their IUPAC systematic names (following IUPAC nomenclature ), traditional names have also been kept where they are in wide use or of significant historical interests.
(only simple oxides, oxyhalides, and related compounds, not hydroxides, carbonates, acids, or other compounds listed elsewhere) | https://en.wikipedia.org/wiki/List_of_inorganic_compounds |
Well-known inorganic and organometallic compounds and reagents that are named after individuals include: | https://en.wikipedia.org/wiki/List_of_inorganic_compounds_named_after_people |
The following list includes commercially or artistically important inorganic pigments of natural and synthetic origin. [ 1 ]
Aluminosilicate pigments
Copper pigments
Cobalt pigments
Manganese pigments
Organic pigments
Aluminosilicate pigments
Cobalt pigments
Iron pigments
Manganese pigments
Arsenic Pigments
Cadmium pigments
Chromium pigments
Cobalt pigments
Copper pigments
Other pigments
Arsenic pigments
Bismuth pigments
Cadmium pigments
Chromium pigments
Cobalt pigments
Iron pigments
Lead pigments
Titanium pigments
Tin pigments
Zinc pigments
Cadmium pigments
Vanadium pigments
Arsenic pigments
Cadmium pigments
Cerium pigments
Iron oxide pigments
Lead pigments
Mercury pigments
Clay earth pigments (naturally formed iron oxides)
Carbonaceous pigments
Iron pigments
Manganese pigments
Titanium pigments
Others
Antimony pigment
Barium pigments
Lead pigment
Titanium pigment
Zinc pigments
A number of pigments, especially traditional ones, contain heavy metals such as lead, mercury, and cadmium that are highly toxic. The use of these pigments is now highly restricted in many countries. [ 1 ] | https://en.wikipedia.org/wiki/List_of_inorganic_pigments |
Well-known types of reactions that involve inorganic compounds include: | https://en.wikipedia.org/wiki/List_of_inorganic_reactions |
This is intended as a non-exhaustive list of input methods for Unix platforms . An input method is a means of entering characters and glyphs that have a corresponding encoding in a character set . See the input method page for more information. | https://en.wikipedia.org/wiki/List_of_input_methods_for_Unix_platforms |
This is a list of insecticides . These are chemical compounds which have been registered as insecticides . Biological insecticides are not included. The names on the list are the ISO common names . A complete list of pesticide common names is published by the BCPC . [ 1 ] The University of Hertfordshire maintains a database of the chemical and biological properties of these materials, [ 2 ] including their brand names and the countries and dates where and when they have been introduced. [ 3 ] The industry-sponsored Insecticide Resistance Action Committee (IRAC) advises on the use of insecticides in crop protection and classifies the available compounds according to their chemical classes and mechanism of action so as to manage the risks of pesticide resistance developing. [ 4 ] The 2024 IRAC poster of insecticide modes of action includes the majority of chemicals listed below. [ 5 ] The pesticide manual provides much information on pesticides. [ 6 ] [ 7 ]
Many of the insecticides in the list are not in use. The developer of a pesticide applies for a common name when they intend to sell it, but some nevertheless do not reach the market. Many insecticides have been banned or otherwise withdrawn from the market over the decades.
Pesticides are sold under their brand names . The purchased pesticide is a mixture ( formulation ) of the active ingredient , which is the pesticide itself, and inert ingredients, such as emulsifiers , or surfactants . Only the common names of the active ingredients are shown in this list. These are approved by ISO committee (TC81). [ 8 ] Common names are used by the authorities, in scientific literature and on the labelling information of purchasable pesticides. | https://en.wikipedia.org/wiki/List_of_insecticides |
Instruments used in Anatomy dissections are as follows: | https://en.wikipedia.org/wiki/List_of_instruments_used_in_anatomy |
Instruments used in Forensics , including autopsy dissections are as follows: [ 1 ]
before replacing it with embalming fluids like formaldehyde for
preservation of structures as practiced in Anatomy
position during dissection
the sternum
cap [ 2 ]
chest [ 3 ]
usually nylon to close the body cavities and sutures it
an autopsy to return the body to a natural looking state to prepare it for burial
collect a urine sample
contents; usually it is not used
gas, specially for infants (lungs, intestine) as a sign of postpartum life
that it doesn't fall back into the pharynx
preservative for Autopsy; video link
Serological, chemical and genetic testings are done by the respective
people of these branches. | https://en.wikipedia.org/wiki/List_of_instruments_used_in_forensics |
This is a list of instruments used in microbiological sterilization and disinfection . [ 1 ] [ 2 ] [ 3 ] | https://en.wikipedia.org/wiki/List_of_instruments_used_in_microbiological_sterilization_and_disinfection |
Instruments used specially in Toxicology are as follows: [ 1 ] [ 2 ] [ 3 ] [ 4 ] | https://en.wikipedia.org/wiki/List_of_instruments_used_in_toxicology |
Interactive geometry software ( IGS ) or dynamic geometry environments ( DGEs ) are computer programs which allow one to create and then manipulate geometric constructions, primarily in plane geometry . In most IGS, one starts construction by putting a few points and using them to define new objects such as lines , circles or other points. After some construction is done, one can move the points one started with and see how the construction changes.
The earliest IGS was the Geometric Supposer, which was developed in the early 1980s. [ 1 ] This was soon followed by Cabri in 1986 and The Geometer's Sketchpad.
There are three main types of computer environments for studying school geometry: supposers [ vague ] , dynamic geometry environments (DGEs) and Logo -based programs. [ 2 ] Most are DGEs: software that allows the user to manipulate ("drag") the geometric object into different shapes or positions. The main example of a supposer is the Geometric Supposer, which does not have draggable objects, but allows students to study pre-defined shapes. Nearly all of the following programs are DGEs. For a related, comparative physical example of these algorithms, see Lenart Sphere .
The following table provides a first comparison of the different software according to their license and platform.
The following table provides a more detailed comparison:
Features related to macro constructions: (TODO)
Loci features related to IGS: (TODO)
We detail here the proof related features. (TODO)
Measurement and calculation features related to IGS: (TODO)
C.a.R. is a free GPL analog of The Geometer's Sketchpad (GSP), written in Java .
Cabri Cabri was developed by the French school of mathematics education in Grenoble (Laborde, 1993)
CaRMetal is a free GPL software written in Java . Derived from C.a.R., it provides a different user interface.
Cinderella , written in Java , is very different from The Geometer's Sketchpad. The later version Cinderella.2 also includes a physics simulation engine and a scripting language. Also, it now [ when? ] supports macros, line segments, calculations, arbitrary functions, plots, etc. Full documentation is available online.
Dr Genius was an attempt to merge Dr. Geo and the Genius calculator .
Dr. Geo is a GPL interactive software intended for younger students (7-15). The later version, Dr. Geo II, [ 4 ] is a complete rewrite of Dr. Geo, for the Squeak / Smalltalk environment.
GCLC [ 5 ] is a dynamic geometry tool for visualizing and teaching geometry, and for producing mathematical illustrations. In GCLC, figures are described rather than drawn. This approach stresses the fact that geometrical constructions are abstract, formal procedures and not figures. A concrete figure can be generated on the basis of the abstract description. There are several output formats, including LaTeX , LaTeX/PStricks, LaTeX/Tikz, SVG and PostScript . There is a built-in geometry theorem prover (based on the area method). GCLC is available for Windows and Linux . WinGCLC is a Windows version of GCLC with a graphical interface that provides a range of additional functionalities. GCLC is open source software (licence CC BY-ND).
GeoGebra is software that combines geometry, algebra and calculus for mathematics education in schools and universities. It is available free of charge for non-commercial users. [ 6 ]
GeoKone.NET [ 7 ] is an interactive recursive natural geometry (or "sacred geometry") generator that runs in a web browser. GeoKone allows the user to create geometric figures using naturalistic rules of recursive copying, such as the Golden ratio .
Geolog [ 8 ] is a logic programming language for finitary geometric logic.
Geometry Expressions [ 9 ] Does symbolic geometry. It uses real symbolic inputs and returns real and symbolic outputs. It emphasises use with a Computer Algebra System (CAS), as well as exporting and sharing via interactive HTML5 , Lua and OS X dashboard widget apps.
The Geometer's Sketchpad (GSP)
The Geometric Supposer [ 10 ]
Geonext was developed by the University of Bayreuth until 2007 and is completely implemented in Java. Its final version was 1.74.
GeoProof [ 11 ] is a free GPL dynamic geometry software, written in OCaml .
GEUP is a more calculus-oriented analog of The Geometer's Sketchpad.
GRACE (The Graphical Ruler And Compass Editor) is an analog of The Geometer's Sketchpad (GSP), written in Java .
Jeometry is a dynamic geometry applet.
Kig is a free ( GPL ) analog of The Geometer's Sketchpad (GSP) for KDE , but more calculus-oriented. It is a part of the KDE Edutainment Project .
KmPlot is a mathematical function plotter released under the free GPL license . Includes a powerful parser and precision printing in correct scale. Simultaneously plot multiple functions and combine function terms to build new functions. Supports functions with parameters and functions in polar coordinates. Several grid modes are available. Features include:
KSEG is a free ( GPL ) analog of The Geometer's Sketchpad (GSP) with some unique features. This software can handle heavy, complex constructions in Euclidean geometry.
Live Geometry is a free CodePlex project that lets you create interactive ruler and compass constructions and experiment with them. It is written in Silverlight 4 and C# 4.0 (Visual Studio 2010). The core engine is a flexible and extensible framework that allows easy addition of new figure types and features. The project has two front-ends: WPF and Silverlight, which both share the common DynamicGeometry library.
TracenPoche is a completely Adobe Flash program. It is available in English, Spanish, and French.
Cabri Geometry
Archimedes Geo3D is a shareware program designed for 3D geometric constructions. It extends traditional ruler and compass constructions into 3D space, allowing users to work with elements such as points, lines, circles, planes, spheres, vectors, and loci. This software is compatible with Windows , macOS , and Linux platforms.
Euler (software)
Euler 3D is a program that allows you to create and manipulate your own polyhedrons. It has a number of facilities: transformations, animations, creating duals, import/export VRML, etc.
Free registration required.
GeoGebra , includes a 3D mode since version 5.0
Geomview
GEUP
All these programs can be divided into two category: deterministic and continuous.
GeoGebra can be deterministic or continuous (one can change it in preferences).
All constructions in the deterministic programs (GSP, Cabri, Kseg and most of others) are completely determined by the given points but the result of some constructions can jump or behave unexpectedly when a given point is moved.
On the contrary, some constructions in continuous programs (so far only Cinderella and GeoGebra), depend on the number of hidden parameters and in such a way that moving a given point produces a continuous motion of the construction, as a result, if the point is moved back to the original position the result of construction might be different.
Here is a test to check whether a particular program is continuous:
Construct the orthocenter of triangle and three midpoints (say A', B' C' ) between vertices and orthocenter.
Construct a circumcircle of A'B'C' .
This is the nine-point circle , it intersects each side of the original triangle at two points: the base of altitude and midpoint. Construct an intersection of one side with the circle at midpoint now move opposite vertex of the original triangle, if the constructed point does not move when base of altitude moves through it that probably means that your program is continuous.
Although it is possible to make a deterministic program which behaves continuously in this and similar simple examples, in general it can be proved that no program can be continuous and deterministic at the same time. [ 12 ] | https://en.wikipedia.org/wiki/List_of_interactive_geometry_software |
This is a list of interface bit rates , a measure of information transfer rates , or digital bandwidth capacity , at which digital interfaces in a computer or network can communicate over various kinds of buses and channels . The distinction can be arbitrary between a computer bus , often closer in space, and larger telecommunications networks . Many device interfaces or protocols (e.g., SATA, USB, SAS , PCIe ) are used both inside many-device boxes, such as a PC, and one-device-boxes, such as a hard drive enclosure . Accordingly, this page lists both the internal ribbon and external communications cable standards together in one sortable table.
Most of the listed rates are theoretical maximum throughput measures; in practice, the actual effective throughput is almost inevitably lower in proportion to the load from other devices ( network / bus contention ), physical or temporal distances, and other overhead in data link layer protocols etc. The maximum goodput (for example, the file transfer rate) may be even lower due to higher layer protocol overhead and data packet retransmissions caused by line noise or interference such as crosstalk , or lost packets in congested intermediate network nodes. All protocols lose something, and the more robust ones that deal resiliently with very many failure situations tend to lose more maximum throughput to get higher total long-term rates.
Device interfaces where one bus transfers data via another will be limited to the throughput of the slowest interface, at best. For instance, SATA revision 3.0 ( 6 Gbit/s ) controllers on one PCI Express 2.0 ( 5 Gbit/s ) channel will be limited to the 5 Gbit/s rate and have to employ more channels to get around this problem. Early implementations of new protocols very often have this kind of problem. The physical phenomena on which the device relies (such as spinning platters in a hard drive) will also impose limits; for instance, no spinning platter shipping in 2009 saturates SATA revision 2.0 ( 3 Gbit/s ), so moving from this 3 Gbit/s interface to USB 3.0 at 4.8 Gbit/s for one spinning drive will result in no increase in realized transfer rate.
Contention in a wireless or noisy spectrum, where the physical medium is entirely out of the control of those who specify the protocol, requires measures that also use up throughput. Wireless devices, BPL , and modems may produce a higher line rate or gross bit rate , due to error-correcting codes and other physical layer overhead. It is extremely common for throughput to be far less than half of theoretical maximum, though the more recent technologies (notably BPL) employ preemptive spectrum analysis to avoid this and so have much more potential to reach actual gigabit rates in practice than prior modems.
Another factor reducing throughput is deliberate policy decisions made by Internet service providers that are made for contractual, risk management, aggregation saturation, or marketing reasons. Examples are rate limiting , bandwidth throttling , and the assignment of IP addresses to groups. These practices tend to minimize the throughput available to every user, but maximize the number of users that can be supported on one backbone.
Furthermore, chips are often not available in order to implement the fastest rates. AMD , for instance, does not support the 32-bit HyperTransport interface on any CPU it has shipped as of the end of 2009. Additionally, WiMAX service providers in the US typically support only up to 4 Mbit/s as of the end of 2009.
Choosing service providers or interfaces based on theoretical maxima is unwise, especially for commercial needs. A good example is large scale data centers, which should be more concerned with price per port to support the interface, wattage and heat considerations, and total cost of the solution. Because some protocols such as SCSI and Ethernet now operate many orders of magnitude faster than when originally deployed, scalability of the interface is one major factor, as it prevents costly shifts to technologies that are not backward compatible. Underscoring this is the fact that these shifts often happen involuntarily or by surprise, especially when a vendor abandons support for a proprietary system.
By convention, bus and network data rates are denoted either in bits per second – bit/s , kbit/s ( 10 3 bit/s ), Mbit/s ( 10 6 bit/s ), Gbit/s ( 10 9 bit/s ), Tbit/s ( 10 12 bit/s ) – or bytes per second – B/s , kB/s ( 10 3 B/s ), MB/s ( 10 6 B/s ), GB/s ( 10 9 B/s ), TB/s ( 10 12 B/s ). In general, parallel interfaces are quoted in B/s and serial in bit/s . The more commonly used is shown below in bold type.
On devices like modems , bytes may be more than 8 bits long because they may be individually padded out with additional start and stop bits; the figures below will reflect this. Where channels use line codes (such as Ethernet , Serial ATA , and PCI Express ), quoted rates are for the decoded signal.
The figures below are simplex data rates, which may conflict with the duplex rates vendors sometimes use in promotional materials. Where two values are listed, the first value is the downstream rate and the second value is the upstream rate.
The use of decimal prefixes is standard in data communications.
The figures below are grouped by network or bus type, then sorted within each group from lowest to highest bandwidth; gray shading indicates a lack of known implementations.
As stated above, all quoted bandwidths are for each direction. Therefore, for duplex interfaces (capable of simultaneous transmission both ways), the stated values are simplex (one way) speeds, rather than total upstream+downstream.
Time signal station to radio clock
802.11 networks in infrastructure mode are half-duplex; all stations share the medium. In infrastructure or access point mode, all traffic has to pass through an Access Point (AP). Thus, two stations on the same access point that are communicating with each other must have each and every frame transmitted twice: from the sender to the access point, then from the access point to the receiver. This approximately halves the effective bandwidth.
802.11 networks in ad hoc mode are still half-duplex, but devices communicate directly rather than through an access point. In this mode all devices must be able to see each other, instead of only having to be able to see the access point.
x LPC protocol includes high overhead. While the gross data rate equals 33.3 million 4-bit-transfers per second (or 16.67 MB/s ), the fastest transfer, firmware read, results in 15.63 MB/s . The next fastest bus cycle, 32-bit ISA-style DMA write, yields only 6.67 MB/s . Other transfers may be as low as 2 MB/s . [ 42 ]
y Uses 128b/130b encoding, meaning that about 1.54% of each transfer is used for error detection instead of carrying data between the hardware components at each end of the interface. For example, a single link PCIe 3.0 interface has an 8 Gbit/s transfer rate, yet its usable bandwidth is only about 7.88 Gbit/s .
z Uses 8b/10b encoding , meaning that 20% of each transfer is used by the interface instead of carrying data from between the hardware components at each end of the interface. For example, a single link PCIe 1.0 has a 2.5 Gbit/s transfer rate, yet its usable bandwidth is only 2 Gbit/s (250 MB/s).
w Uses PAM-4 encoding and a 256 bytes FLIT block, of which 14 bytes are FEC and CRC , meaning that 5.47% of total data rate is used for error detection and correction instead of carrying data. For example, a single link PCIe 6.0 interface has a 64 Gbit/s total transfer rate, yet its usable bandwidth is only 60.5 Gbit/s .
a Uses 8b/10b encoding b Uses 64b/66b encoding c Uses 128b/150b encoding
The table below shows values for PC memory module types.
These modules usually combine multiple chips on one circuit board .
SIMM modules connect to the computer via an 8-bit- or 32-bit-wide interface. RIMM modules used by RDRAM are 16-bit- or 32-bit-wide. [ 49 ] DIMM modules connect to the computer via a 64-bit-wide interface.
Some other computer architectures use different modules with a different bus width.
In a single-channel configuration, only one module at a time can transfer information to the CPU.
In multi-channel configurations, multiple modules can transfer information to the CPU at the same time, in parallel. FPM , EDO , SDR , and RDRAM memory was not commonly installed in a dual-channel configuration. DDR and DDR2 memory is usually installed in single- or dual-channel configuration. DDR3 memory is installed in single-, dual-, tri-, and quad-channel configurations.
Bit rates of multi-channel configurations are the product of the module bit-rate (given below) and the number of channels.
a The clock rate at which DRAM memory cells operate. The memory latency is largely determined by this rate. Note that until the introduction of DDR4 the internal clock rate saw relatively slow progress. DDR / DDR2 / DDR3 memory uses 2n/4n/8n (respectively) prefetch buffer to provide higher throughput, while the internal memory speed remains similar to that of the previous generation.
b The memory speed or clock rate advertised by manufactures and suppliers usually refers to this rate (with 1 GT/s = 1 GHz). Note that modern types of memory use DDR bus with two transfers per clock.
RAM memory modules are also utilised by graphics processing units ; however, memory modules for those differ somewhat from standard computer memory, particularly with lower power requirements, and are specialised to serve GPUs: for example, GDDR3 was fundamentally based on DDR2 . Every graphics memory chip is directly connected to the GPU (point-to-point). The total GPU memory bus width varies with the number of memory chips and the number of lanes per chip. For example, GDDR5 specifies either 16 or 32 lanes per device (chip), while GDDR5X specifies 64 lanes per chip. Over the years, bus widths rose from 64-bit to 512-bit and beyond: e.g. HBM is 1024 bits wide. [ 50 ] Because of this variability, graphics memory speeds are sometimes compared per pin. For direct comparison to the values for 64-bit modules shown above, video RAM is compared here in 64-lane lots, corresponding to two chips for those devices with 32-bit widths.
In 2012, high-end GPUs used 8 or even 12 chips with 32 lanes each, for a total memory bus width of 256 or 384 bits. Combined with a transfer rate per pin of 5 GT/s or more, such cards could reach 240 GB/s or more.
RAM frequencies used for a given chip technology vary greatly. Where single values are given below, they are examples from high-end cards. [ 51 ] Since many cards have more than one pair of chips, the total bandwidth is correspondingly higher. For example, high-end cards often have eight chips, each 32 bits wide, so the total bandwidth for such cards is four times the value given below.
Data rates given are from the video source (e.g., video card) to receiving device (e.g., monitor) only. Out of band and reverse signaling channels are not included.
a Uses 8b/10b encoding (20% coding overhead) b Uses 16b/18b encoding (11% overhead) c Uses 128b/132b encoding (3% overhead) | https://en.wikipedia.org/wiki/List_of_interface_bit_rates |
Interstitial cell refers to any cell that lies in the spaces between the functional cells of a tissue .
Examples include: | https://en.wikipedia.org/wiki/List_of_interstitial_cells |
The following is a list of inventions, discoveries and scientific advancements made in the medieval Islamic world , especially during the Islamic Golden Age , [ 1 ] [ 2 ] [ 3 ] [ 4 ] as well as in later states of the Age of the Islamic Gunpowders such as the Ottoman and Mughal empires .
The Islamic Golden Age was a period of cultural, economic and scientific flourishing in the history of Islam , traditionally dated from the eighth century to the fourteenth century, with several contemporary scholars [ who? ] dating the end of the era to the fifteenth or sixteenth century. [ 3 ] [ 4 ] [ 5 ] This period is traditionally understood to have begun during the reign of the Abbasid caliph Harun al-Rashid (786 to 809) with the inauguration of the House of Wisdom in Baghdad , where scholars from various parts of the world with different cultural backgrounds were mandated to gather and translate all of the world's classical knowledge into the Arabic language and subsequently development in various fields of sciences began. Science and technology in the Islamic world adopted and preserved knowledge and technologies from contemporary and earlier civilizations, including Persia, Egypt, India, China, and Greco-Roman antiquity, while making numerous improvements, innovations and inventions.
"Three scientists, Ibn al-Haytham, Khayyam and al-Tūsī, had made the most considerable contribution to this branch of geometry whose importance came to be completely recognized only in the 19th century. In essence their propositions concerning the properties of quadrangles which they considered assuming that some of the angles of these figures were acute of obtuse, embodied the first few theorems of the hyperbolic and the elliptic geometries. Their other proposals showed that various geometric statements were equivalent to the Euclidean postulate V. It is extremely important that these scholars established the mutual connection between this postulate and the sum of the angles of a triangle and a quadrangle. By their works on the theory of parallel lines Arab mathematicians directly influenced the relevant investigations of their European counterparts. The first European attempt to prove the postulate on parallel lines – made by Witelo, the Polish scientists of the 13th century, while revising Ibn al-Haytham's Book of Optics ( Kitab al-Manazir ) – was undoubtedly prompted by Arabic sources. The proofs put forward in the 14th century by the Jewish scholar Levi ben Gerson , who lived in southern France, and by the above-mentioned Alfonso from Spain directly border on Ibn al-Haytham's demonstration. Above, we have demonstrated that Pseudo-Tusi's Exposition of Euclid had stimulated both J. Wallis's and G. Saccheri's studies of the theory of parallel lines." | https://en.wikipedia.org/wiki/List_of_inventions_in_the_medieval_Islamic_world |
This is a list of investigational aggression drugs , or drugs that are currently under development for clinical use in the treatment of aggression but are not yet approved. Drugs used to treat aggression may also be known as " serenics ". [ 1 ]
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in February 2025. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_aggression_drugs |
This is a list of investigational agitation drugs , or drugs that are currently under development for clinical use in the treatment of agitation , for instance in people with dementia or autism , but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in February 2025. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_agitation_drugs |
This is a list of investigational analgesics , or analgesics that are currently under development for clinical use but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in June 2017. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_analgesics |
This is a list of investigational antidepressants , or drugs that are currently under development for clinical use in the treatment of depression but are not yet approved. Specific indications include major depressive disorder , treatment-resistant depression , dysthymia , bipolar depression , and postpartum depression , among others.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in August 2024. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_antidepressants |
This is a list of investigational antipsychotics , or antipsychotics that are currently under development for clinical use but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in December 2017. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_antipsychotics |
This is a list of investigational anxiolytics , or anxiolytics that are currently under development for clinical use but are not yet approved. Chemical/ generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in June 2017. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_anxiolytics |
This is a list of investigational attention deficit hyperactivity disorder drugs , or drugs that are currently under development for clinical use in the treatment of attention deficit hyperactivity disorder (ADHD) but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in September 2021. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_attention_deficit_hyperactivity_disorder_drugs |
This is a list of investigational autism and pervasive developmental disorder drugs , or drugs that are currently under development for clinical use in the treatment of autistic spectrum disorders and/or other pervasive developmental disorders but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in October 2024. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_autism_and_pervasive_developmental_disorder_drugs |
This is a list of investigational borderline personality disorder drugs , or drugs that are currently under development for clinical use in the treatment of borderline personality disorder (BPD) but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in March 2025. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_borderline_personality_disorder_drugs |
This is a list of investigational hallucinogens and entactogens , or hallucinogens and entactogens that are currently under formal development for clinical use but are not yet approved. [ 1 ]
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses. The list also includes non-hallucinogenic drugs related to hallucinogens, such as non-hallucinogenic serotonin 5-HT 2A receptor agonists and non-hallucinogenic ketamine analogues . Cannabinoids , or cannabinoid receptor modulators, are not included in this list. Many of the indications are not for continuous medication therapy but rather are for medication-assisted psychotherapy or short-term use only. The section that the drug is in corresponds to its highest developmental phase, not its phase for all listed indications.
This list was last comprehensively updated in October 2024. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_hallucinogens_and_entactogens |
This is a list of investigational obsessive–compulsive disorder drugs , or drugs that are currently under development for clinical use in the treatment of obsessive–compulsive disorder (OCD) but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in September 2021. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_obsessive–compulsive_disorder_drugs |
This is a list of investigational sex-hormonal agents , or sex-hormonal agents that are currently under development for clinical use but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated sometime between May 2017 and September 2021. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_sex-hormonal_agents |
This is a list of investigational sexual dysfunction drugs , or drugs that are currently under development for clinical treatment of sexual dysfunction but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in June 2017. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_sexual_dysfunction_drugs |
This is a list of investigational sleep drugs , or drugs for the treatment of sleep disorders that are currently under development for clinical use but are not yet approved. Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated sometime between June 2017 and August 2021. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_sleep_drugs |
This is a list of investigational social anxiety disorder drugs , or drugs that are currently under development for clinical use in the treatment of social anxiety disorder (SAD; or social phobia) but are not yet approved.
Chemical/generic names are listed first, with developmental code names, synonyms, and brand names in parentheses.
This list was last comprehensively updated in August 2024. It is likely to become outdated with time. | https://en.wikipedia.org/wiki/List_of_investigational_social_anxiety_disorder_drugs |
This is the list of the 75 isomers of decane . [ 1 ] [ 2 ] | https://en.wikipedia.org/wiki/List_of_isomers_of_decane |
This is the list of 355 isomers of dodecane . [ 1 ] | https://en.wikipedia.org/wiki/List_of_isomers_of_dodecane |
This is the list of structural isomers of nonane . There are 35. [ citation needed ]
Isomers where hexane is the longest chain:
Isomers where pentane is the longest chain | https://en.wikipedia.org/wiki/List_of_isomers_of_nonane |
This is the list of the 1858 isomers of tetradecane . [ 1 ] | https://en.wikipedia.org/wiki/List_of_isomers_of_tetradecane |
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